NSF 1998 Senior Design Projects to Aid Persons with Disabilities

Transcription

NATIONAL SCIENCE FOUNDATION
1998
ENGINEERING SENIOR DESIGN
PROJECTS TO AID PERSONS WITH
DISABILITIES
Edited By
John D. Enderle
Brooke Hallowell
NATIONAL SCIENCE
FOUNDATION
1998
PROJECTS TO AID PERSONS
WITH DISABILITIES
Edited By
John D. Enderle
Brooke Hallowell
Creative Learning Press, Inc.
P.O. Box 320
Mansfield Center, Connecticut 06250
i
PUBLICATION POLICY
Enderle, John Denis
National Science Foundation 1998 Engineering Senior Design
Projects To Aid Persons With Disabilities / John D.
Enderle, Brooke Hallowell
Includes index
ISBN 0936386851
Copyright  2000 by Creative Learning Press, Inc.
P.O. Box 320
Mansfield Center, Connecticut 06250
All Rights Reserved. These papers may be freely reproduced and distributed as long as the source is credited.
Printed in the United States of America
ii
CONTENTS
CONTRIBUTING AUTHORS.....................................................................................................IX
FOREWORD...................................................................................................................................XI
CHAPTER 1
INTRODUCTION..............................................................................................1
CHAPTER 2
EDUCATIONAL OUTCOMES ASSESSMENT:IMPROVING DESIGN
PROJECTS TO AID PERSONS WITH DISABILITIES .........................................................13
CHAPTER 3 AN INVITATION TO COLLABORATE IN USING ASSESSMENT TO
IMPROVE DESIGN PROJECTS.................................................................................................17
CHAPTER 4
ARIZONA STATE UNIVERSITY...................................................................21
VOLUNTARY-OPENING TRANSRADIAL PROSTHESIS FOR USE WITH WEIGHT TRAINING
EQUIPMENT .....................................................................................................................................................................22
SHOWER CHAIR FOR A CLIENT WITH DE SANTIS CACHIONE ................................................................28
A FLY CASTING ORTHOSIS FOR A PATIENT WITH QUADRIPLEGIA......................................................30
AN EXERCISE/RANGE-OF-MOTION BIKE FOR A PATIENT WITH PARAPLEGIA...............................32
CHAPTER 5
BINGHAMTON UNIVERSITY.......................................................................35
COLLAPSIBLE ACTIVITY FRAME.............................................................................................................................36
ADJUSTABLE HEIGHT COMPUTER MONITOR..................................................................................................37
BALANCE BEAM.............................................................................................................................................................38
BED RAIL ASSIST ............................................................................................................................................................39
CART WITH BASKET.....................................................................................................................................................40
CHAIR ADJUSTMENT...................................................................................................................................................41
DOUBLE PEDAL BOARD .............................................................................................................................................42
FOLDING CHAIR ............................................................................................................................................................43
HEAD SUPPORT FOR CHAIR.....................................................................................................................................44
iii
THE HEAD SWITCH ......................................................................................................................................................45
ADJUSTABLE PENCIL GRIPPER ...............................................................................................................................46
PUPPET THEATRE .........................................................................................................................................................47
SCOOTER BOARD...........................................................................................................................................................48
SIT-AND-SPIN TOY FOR LARGER CHILDREN AND ADULTS .....................................................................49
STAND-PIVOT SYSTEM................................................................................................................................................50
FLOTATION BELT...........................................................................................................................................................51
TABLE FOR BENNETT BENCH..................................................................................................................................52
ADJUSTABLE MULTI-USER COMPUTER STATION ..........................................................................................53
WHEELCHAIR STORAGE RACK ..............................................................................................................................54
FOOT-PROPELLED WHEELCHAIR..........................................................................................................................55
ADJUSTABLE WALKER................................................................................................................................................56
AUTOMATIC ROCKER FOR AN EASY CHAIR ....................................................................................................58
CLIMBING WALL FOR YOUNG CHILDREN........................................................................................................60
COLLAPSIBLE CANE FOR THE BLIND ..................................................................................................................62
ELECTRONIC LOCK.......................................................................................................................................................64
A RACE CAR FOR CHILDREN...................................................................................................................................65
POOL LIFT FOR SMALL CHILD.................................................................................................................................66
PORTABLE SWIMMING POOL STAIRS ..................................................................................................................68
PRESSURE VEST..............................................................................................................................................................70
BLOW-STRAW UNIVERSAL REMOTE CONTROL .............................................................................................72
WHEELCHAIR SWING .................................................................................................................................................74
CHAPTER 6
DUKE UNIVERSITY .........................................................................................77
SENSORY STIMULATION ACTIVITY CENTER....................................................................................................78
CHILD-FRIENDLY ACTIVITY TIMER ......................................................................................................................82
COMPUTER GAMES FOR LEARNING JOYSTICK CONTROL ........................................................................84
iv
AUTOMATIC FEEDER MODIFICATIONS AND WHEELCHAIR-TO-BED TRANSFER
APPARATUS.....................................................................................................................................................................86
POOL CHAIR ....................................................................................................................................................................88
CHAPTER 7
MANHATTAN COLLEGE ...............................................................................91
AUTOMATED DIE ROLLING DEVICE.....................................................................................................................92
VENTILATING SYSTEM FOR A NURSING HOME GREENHOUSE .............................................................94
MODIFICATIONS AND ENHANCEMENTS TO A CONSOLE TV STAND..................................................96
ENHANCED ELECTRONIC TV CONTROL SYSTEM .........................................................................................97
A TABLE-SIZE ROULETTE WHEEL..........................................................................................................................98
A PNEUMATIC TV CONTROL SYSTEM ................................................................................................................99
A PNEUMATIC TV CONTROL SYSTEM .................................................................................................................100
CHAPTER 8
MISSISSIPPI STATE UNIVERSITY .............................................................103
TRAIL READY UTILITY VEHICLE FOR PEOPLE WITH PHYSICAL DISABILITIES.................................104
ROLLER WALKER WITH SPRING-ACTIVATED BRAKING SYSTEM FOR A PATIENT WITH
CEREBRAL PALSY..........................................................................................................................................................106
WHEELCHAIR SEAT WITH AIR ROTATION TO RELIEVE PRESSURE ......................................................108
CHAPTER 9
NEW JERSEY INSTITUTE OF TECHNOLOGY .........................................111
PC INTERFACE ENVIRONMENTAL CONTROL UNIT.....................................................................................112
SPEECH RECOGNITION FOR AN ENVIRONMENTAL CONTROL UNIT .................................................113
SPEECH RECOGNITION FOR ENVIRONMENTAL CONTROL OF A WHEELCHAIR ...........................114
CHAPTER 10
NORTH CAROLINA STATE UNIVERSITY ...........................................115
EVALUATION AND TREATMENT TABLE............................................................................................................116
BICYCLE CART FOR A CHILD ...................................................................................................................................118
CHAPTER 11
NORTH DAKOTA STATE UNIVERSITY................................................121
VOICE RECOGNITION CLOCK..................................................................................................................................122
ALARM CLOCK FOR INDIVIDUALS WITH HEARING IMPAIRMENT.......................................................124
CAMERA FOR INDIVIDUALS WITH VISUAL IMPAIRMENT OR BLINDNESS........................................126
v
EXERCISE ENHANCER ...............................................................................................................................................128
FORCE MEASUREMENT FOR PROSTHETICS......................................................................................................130
VOICE SPECTRUM ANALYSIS...................................................................................................................................132
CHAPTER 12
NORTHERN ILLINOIS UNIVERSITY .....................................................135
VOICE PITCH ANALYZER ..........................................................................................................................................136
A DSP-BASED WIRELESS INFANT MONITORING DEVICE FOR INDIVIDUALS WITH HEARING
IMPAIRMENT...................................................................................................................................................................138
CHAPTER 13
STATE UNIVERSITY OF NEW YORK AT BUFFALO ..........................141
OPHTHALMOLOGIST’S OPTICAL LENS HOLDER FOR SLIT LAMP EYE EXAMS................................142
WHEELCHAIR STEP NEGOTIATOR........................................................................................................................144
BOOK RETRIEVER ..........................................................................................................................................................146
PORTABLE LIFT FOR WHEELCHAIRS ...................................................................................................................148
ASSISTIVE GLOVE: A MECHANICAL EXOSKELETON TO AUGMENT HAND STRENGTH AND
CONTROL..........................................................................................................................................................................150
EMERGENCY VACUUM-PACKED NECK SUPPORT.........................................................................................152
SHOWERHEAD-ATTACHABLE SOAP AND SHAMPOO DISPENSER .......................................................154
AUTOMATED GARBAGE BAG SEALER ................................................................................................................156
ADJUSTABLE ANKLE SUPPORT TO RELIEVE COMPRESSIVE FORCES....................................................158
ASSISTIVE CAR SEAT TO FACILITATE...................................................................................................................160
ENTRY AND EXIT...........................................................................................................................................................160
EASY PUMP FUELING DEVICE FOR SELF- SERVICE GASOLINE DISPENSING.....................................162
STOWABLE WHEELCHAIR UMBRELLA...............................................................................................................164
WHEELCHAIR PROPULSION DEVICE...................................................................................................................166
HEAT EXCHANGER TO PREVENT OR REDUCE EFFECTS OF EXERCISE-INDUCED ASTHMA......168
UTENSIL HOLDER HAND BRACE...........................................................................................................................170
CHAPTER 14
TEXAS A&M UNIVERSITY ........................................................................173
OPTIMIZATION OF ENVIRONMENTAL CONTROL TO FIT A SMALL LIVING SPACE.......................174
vi
AN ARM BRACE FOR USE BY PATIENTS WITH LOWER BACK TROUBLE .............................................178
AUGMENTATIVE COMMUNICATION DEVICE..................................................................................................180
CLOTHES DRYER WITH FRONT MOUNTED CONTROLS FOR HANDICAPPED ACCESS................182
CHAPTER 15
UNIVERSITY OF ALABAMA AT BIRMINGHAM................................187
SHOWER CHAIRS FOR INDIVIDUALS WITH CEREBRAL PALSY...............................................................188
FOREARM MOTION/TORQUE ANALYZER........................................................................................................192
WHEELCHAIR HEADREST DESIGN.......................................................................................................................194
CHAPTER 16
UNIVERSITY OF TENNESSEE AT CHATTANOOGA.........................197
BICYCLE FOR A SMALL CHILD ................................................................................................................................198
COMPUTER WORKSTATION.....................................................................................................................................200
SUPPORTIVE DINING CHAIR....................................................................................................................................202
LAPTOP SUPPORT .........................................................................................................................................................204
PRINTER SUPPORT........................................................................................................................................................206
CHAPTER 17
UNIVERSITY OF TOLEDO.........................................................................209
ADAPTATION OF A RIDING LAWNMOWER FOR A PERSON WITH PARAPLEGIA...........................210
DRINKING SYSTEM FOR PERSONS WITH QUADRIPLEGIA.........................................................................216
ASSISTIVE DEVICE TO START A PULL-START LAWNMOWER...................................................................218
ASSISTIVE DEVICE TO OPEN AND CLOSE LARGE JARS................................................................................220
REACHER DEVICE ........................................................................................................................................................222
WHEELCHAIR BICYCLE-TYPE ATTACHMENT.................................................................................................224
TEMPERATURE CONTROL SHOWER UNIT........................................................................................................226
CHAPTER 18
UTAH STATE UNIVERSITY ......................................................................229
AUTOMATIC ROCKING BENCH SWING ..............................................................................................................230
TRAILER-MOUNTED LIFT SYSTEM FOR HORSEBACK RIDING..................................................................232
REMOTE-CONTROLLED MOTORIZED TOY VEHICLE....................................................................................234
THE SIGHTSEER: ADAPTED OFF-ROAD VEHICLE...........................................................................................236
vii
CHILD’S JOYSTICK-CONTROLLED GO-CART ....................................................................................................238
WHEELCHAIR DYNAMIC SEATING SYSTEM ....................................................................................................240
THREE-WHEELED HAND POWERED CYCLE ....................................................................................................242
DUAL ADAPTIVE RECUMBENT TRICYCLE.........................................................................................................244
CHAPTER 19
WAYNE STATE UNIVERSITY...................................................................247
WHEELCHAIR MOUNTING CLAMP FOR A LAPTOP COMPUTER ............................................................248
ADJUSTABLE PLATFORM FOR AUGMENTATIVE COMMUNICATION DEVICES................................252
MOUTH STICK DOCKING STATION.......................................................................................................................254
LAPTOP COMPUTER CARRYING SYSTEM..........................................................................................................256
LOWER EXTREMITY EXERCISE SYSTEM..............................................................................................................258
CHAPTER 20
WRIGHT STATE UNIVERSITY.................................................................261
BILATERAL ACOUSTIC TRAINER ...........................................................................................................................262
ENVIRONMENTAL CONTROL UNIT .....................................................................................................................266
ADJUSTABLE CHAIR HEIGHT ..................................................................................................................................268
MULTI-FUNCTION SPEECH THERAPY APPARATUS .....................................................................................270
AUTOMATIC JAR OPENER.........................................................................................................................................272
RTA BUS ANNUNCIATOR SYSTEM FOR PERSONS WITH VISUAL IMPAIRMENTS ...........................274
CHAPTER 21
INDEX ..............................................................................................................275
viii
CONTRIBUTING AUTHORS
Susan M. Blanchard, Biological and Agricultural Engineering Department, North Carolina State University,
Raleigh, North Carolina 27695-7625
Mohamed Samir Hefzy, Department of Mechanical Engineering, University Of Toledo, Toledo, Ohio, 43606
Laurence N. Bohs, Department of Biomedical Engineering, Duke University, Durham, North Carolina 277080281
William Hyman, Bioengineering Program, Texas A&M
University,
College
Station,
TX
77843
Richard K. Irey, Department of Mechanical Engineering, University Of Toledo, Toledo, Ohio, 43606
Richard Culver, Mechanical Engineering,
The Watson School, SUNY Binghamton, Binghamton,
NY 13902-6000
Xuan Kong, Department of Electrical Engineering,
Northern Illinois University, DeKalb, IL 60115
Alan W. Eberhardt, University Of Alabama At Birmingham, Department of Materials and Mechanical
Engineering, BEC 254, 1150 10th Ave. S., Birmingham,
Alabama, 35294-4461
Gary M. McFadyen, T.K. Martin Center for Technology
and Disability, P.O. Box 9736, Mississippi State University, Mississippi State, MS 39762
John Enderle, Electrical & Computer Engineering, University of Connecticut, Storrs, CT 06269-2157
Edward H. McMahon, College of Engineering and
Computer Science, University Of Tennessee At Chattanooga Chattanooga, TN 37403
Daniel L. Ewert, Department of Electrical Engineering,
North Dakota State University, Fargo, North Dakota
58105
Joseph C. Mollendorf, Mechanical and Aerospace Engineering, State University of New York at Buffalo,
Buffalo, NY 14260
Bertram N. Ezenwa, Department of Mechanical Engineering, School of Medicine, Department of Physical
Medicine and Rehabilitation, Wayne State University
261 Mack Blvd Detroit MI 48201
Nagi Naganathan, Department of Mechanical, Industrial and Manufacturing Engineering, University Of
Toledo, Toledo, Ohio, 43606-3390
Marvin G. Fifield, Center for Persons with Disabilities,
Utah State University, Logan, Utah 84322-4130
Chandler Phillips, Biomedical and Human Factors Engineering, Wright State University, Dayton, OH
45435
Jacob S. Glower, Department of Electrical Engineering,
58105
Frank Redd, Mechanical & Aerospace Engineering,
Utah State University, Logan, Utah 84322-4130
Jiping He, Chemical, Bio, & Materials Engineering,
Arizona State University, Tempe, AZ 85287-6006
Stanley S. Reisman, Department of Electrical and Computer Engineering, New Jersey Institute Of Technology, Newark, New Jersey 07102
Daniel W. Haines, Dept. of Mechanical Engineering,
Manhattan College, 4513 Manhattan College Parkway, Bronx, NY 10471
David B. Reynolds, Biomedical and Human Factors
Engineering, Wright State University, Dayton, OH
45435
Brooke Hallowell, School of Hearing and Speech Sciences, Lindley Hall 208, Ohio University, Athens, OH
45701
ix
Roger P. Rohrbach, Biological and Agricultural Engineering Department, North Carolina State University,
Mansour Tahernezhadi, Department of Electrical Engineering, Northern Illinois University, DeKalb, IL
60115
Val Tareski, Department of Electrical Engineering,
58105
Gary Yamaguchi, Chemical, Bio, & Materials Engineering, Arizona State University, Tempe, AZ 85287-6006
x
FOREWORD
Welcome to the tenth annual issue of the National
Science Foundation Engineering Senior Design Projects to Aid Persons with Disabilities. In 1988, the
National Science Foundation (NSF) began a program
to provide funds for student engineers at universities
throughout the United States to construct custom designed devices and software for individuals with disabilities. Through the Bioengineering and Research
to Aid the Disabled (BRAD) program of the Emerging
Engineering Technologies Division of NSF,1 funds
were awarded competitively to 16 universities to pay
for supplies, equipment and fabrication costs for the
design projects. A book entitled, NSF 1989 Engineering Senior Design Projects to Aid the Disabled was published in 1989, reporting on the projects that were
funded during the first year of this effort.
Projects to Aid the Disabled, published in 1997, described 94 projects carried out by students at 19 universities across the United States during the academic
1993-94 year.
NSF 1995 Engineering Senior Design Projects to Aid the
Disabled, published in 1998, described 124 projects
carried out by students at 19 universities during the
1994-95 academic year.
NSF 1996 Engineering Senior Design Projects to Aid Persons With Disabilities, published in 1999, presented 93
projects carried out by students at 12 universities during the 1995-96 academic year.
The ninth issue, NSF 1997 Engineering Senior Design
Projects to Aid Persons with Disabilities, published in
2000, included 124 projects carried out by students at
19 universities during the 1994-95 academic year.
In 1989, the BRAD program of the Emerging Engineering Technologies Division of NSF increased the
number of universities funded to 22 in 1989. Following completion of the 1989-1990 design projects, a
second book was published, describing these projects,
entitled, NSF 1990 Engineering Senior Design Projects to
Aid the Disabled.
This book, funded by the NSF, describes and documents the NSF-supported senior design projects during the tenth year academic year of this effort, 199798. Each chapter, except for the first three, describes
activity at a single university, and was written by the
principal investigator(s) at that university, and revised by the editors of this publication. Individuals
wishing more information on a particular design
should contact the designated supervising principal
investigator. An index is provided so that projects
may be easily identified by topic.
North Dakota State University (NDSU) Press published the following three issues. NSF 1991 Engineering Senior Design Projects to Aid the Disabled described
the almost 150 projects carried out by students at 20
universities across the United States during the academic year 1990-91. NSF 1992 Engineering Senior Design Projects to Aid the Disabled presented the almost
150 projects carried out by students at 21 universities
across the United States during the 1991-92 academic
year. The fifth issue described 91 projects carried out
by students at 21 universities across the United States
during the 1992-93 academic year.
It is hoped that this book will enhance the overall
quality of future senior design projects directed toward persons with disabilities by providing examples of previous projects, and by motivating faculty at
other universities to participate because of the potential benefits to students, schools, and communities.
Moreover, the new technologies used in these projects
will provide examples in a broad range of applications for new engineers. The ultimate goal of both
this publication and all the projects that were built
under this initiative is to assist individuals with disabilities in reaching their maximum potential for enjoyable and productive lives.
Creative Learning Press, Inc. has published the succeeding volumes. NSF 1994 Engineering Senior Design
In January of 1994, the Directorate for Engineering
(ENG) was restructured. This program is now in the
Division of Bioengineering and Environmental Systems, Biomedical Engineering & Research Aiding Persons with Disabilities Program.
1
This NSF program has brought together individuals
with widely varied backgrounds. Through the richxi
ness of their interests, a wide variety of projects were
completed, and are in use. A number of different
technologies were incorporated in the design projects,
to maximize the impact of each device on the individual for whom it was developed.
guide should exercise good judgment when advising
students.
Readers familiar with previous editions of this book
will note that John Enderle moved from North Dakota
State University to the University of Connecticut in
1995. With that move, annual publications also
moved from NDSU Press to Creative Learning Press
Inc. in 1997. During 1994, Enderle also served as NSF
Program Director for the Biomedical Engineering &
Research Aiding Persons with Disabilities Program
while on a leave of absence from NDSU.
A two-page project description format is generally
used in this text. Each project is introduced with a
nontechnical description, followed by a summary of
impact that illustrates the effect of the project on an
individual’s life. A detailed technical description
then follows. Photographs of the devices and other
important components are incorporated throughout
the manuscript.
Brooke Hallowell is a faculty member in the School of
Hearing and Speech Sciences at Ohio University.
Hallowell’s primary area of expertise is in neurogenic
communication disorders. She has a long history of
collaboration with colleagues in biomedical engineering, in curriculum development, teaching, assessment, and research.
None of the faculty received financial remuneration
for supervising the building of devices or writing
software within this program. Each participating
university typically has made a five-year commitment
to the program.
Sincere thanks are extended to Dr. Allen Zelman, a
former Program Director of the NSF BRAD program,
for being the prime enthusiast behind this initiative.
Additionally, thanks are extended to Drs. Peter G. Katona, Karen M. Mudry, Fred Bowman and Gil Devey,
former and current NSF Program Directors of the
Biomedical Engineering and Research to Aid Persons
with Disabilities Programs, who have continued to
support and expand the program.
The editors welcome any suggestions as to how this
review may be made more useful for subsequent
yearly issues. Previous editions of this book are
available for viewing at the WEB Site for this project:
http://nsf-pad.bme.uconn.edu/.
John D. Enderle, Ph.D., Editor
Department of Electrical & Systems Engineering
260 Glenbrook Road, U-157
University of Connecticut
Storrs, Connecticut 06269-2157
Voice: (860) 486-5521
FAX: (860) 486-2447
E-mail: [email protected]
We acknowledge and thank Ms. Shari Valenta for the
cover illustration and the artwork throughout the
book, drawn from her observations at the Children's
Hospital Accessibility Resource Center in Denver,
Colorado. We also acknowledge and thank Mr. William Pruehsner for technical illustrations and Dr.
Leon Anderson, Ms. Lollie Vaughan, Ms. Leetal Cuperman, Ms. Kirsten Carr, Ms. Carrie Brannon, and
Mrs. Jean Hallowell for editorial assistance.
Brooke Hallowell, Ph.D., Editor
School of Hearing and Speech Sciences
Lindley Hall 208
Ohio University
Athens, OH 45701
Voice: (740) 593-1356
FAX: (740) 593-0287
The information in this publication is not restricted in
any way. Individuals are encouraged to use the project descriptions in the creation of future design projects for persons with disabilities. The NSF and editors make no representations or warranties of any
kind with respect to these design projects, and specifically disclaim any liability for any incidental or
consequential damages arising from the use of this
publication. Faculty members using the book as a
December 2000
xii
NATIONAL SCIENCE
FOUNDATION
1998
PROJECTS TO AID PERSONS
WITH DISABILITIES
CHAPTER 1
INTRODUCTION
John Enderle and Brooke Hallowell
Devices and software to aid persons with disabilities
often need custom modification, are prohibitively expensive, or nonexistent. Many persons with disabilities do not have access to custom modification of
available devices and other benefits of current technology. Moreover, when available, engineering and
support salaries often make the cost of custom modifications beyond the reach of the persons who need
them.
devices, or custom modifications of devices, that improve the quality of life for persons with disabilities.
The students have opportunities for practical and
creative problem solving to address well-defined
needs, and persons with disabilities receive the products of that process. There is no financial cost incurred by the persons served in this program. Upon
completion, the finished project becomes the property
of the individual for whom it was designed.
In 1988, the National Science Foundation (NSF),
through its Emerging Engineering Technologies Division, initiated a program to support student engineers
at universities throughout the United States designing and building devices for persons with disabilities.
Since its inception, this NSF program (originally
called Bioengineering and Research to Aid the Disabled) has enhanced educational opportunities for
students and improved the quality of life for individuals with disabilities. Students and university
faculty provide, through their Accreditation Board for
Engineering and Technology (ABET) accredited senior design class, engineering time to design and build
the device or software. The NSF provides funds, competitively awarded to universities for supplies,
equipment and fabrication costs for the design projects.
The emphases of the program are to:
•
Provide disabled children and adults student-engineered devices or software to improve their quality of life and provide greater
for self-sufficiency;
•
Enhance the education of student engineers
by designing and building a device or software that meets a real need; and
•
Allow the university an opportunity for
unique service to the local community.
Local school districts and hospitals participate in the
effort by referring interested individuals to the program. A single student or a team of students specifically designs each project for an individual or a
group of individuals with a similar need. Examples
of projects completed in years past include a laserpointing device for people who cannot use their
hands, a speech aid, a behavior modification device, a
hands-free automatic answering and hang-up telephone system, and an infrared beacon to help a blind
person move around a room. The students participating in this project have been singularly rewarded
through their activity with persons with disabilities,
and justly have experienced a unique sense of purpose and pride in their accomplishment.
Outside of the NSF program, students are typically
involved in design projects that incorporate academic
goals for solid curricular design experiences, but that
do not necessarily enrich the quality of life for persons other than, perhaps, the students themselves.
For instance, students might design and construct a
stereo receiver, a robotic unit that performs a household chore, or a model racecar.
Under this NSF program, engineering design students are involved in projects that result in original
1
2 NSF 1998 Engineering Senior Design Projects to Aid Persons with Disabilities
The Current Book
This book describes the NSF supported senior design
projects during the tenth year of this effort during the
academic year 1997-98. The purpose of this publication is twofold. First, it is to serve as a reference or
handbook for future senior design projects. Students
are exposed to this unique body of applied information on current technology in this and previous editions of this book. This provides an even broader
education than typically experienced in an undergraduate curriculum, especially in the area of rehabilitation design.
Many technological advances
originate from work in the space, defense, entertainment and communications industry. Few of these
advances have been applied to the rehabilitation
field, making the contributions of this NSF program
all the more important.
Secondly, it is hoped that this publication will serve
to motivate students, graduate engineers and others
to work more actively in rehabilitation. This will
ideally lead to an increased technology and
knowledge base to effectively address the needs of
persons with disabilities.
This introduction provides background material on
the book, elements of design, and highlights the engineering design experiences at three universities that
have participated in this effort.
After the introduction, 17 chapters follow, with each
chapter devoted to one participating school. At the
start of each chapter, the school and the principal investigator(s) are identified. Each project description is
written using the following format. On page one, the
individuals involved with the project are identified,
including the student(s), the professor(s) who supervised the project, and key professionals involved in
the daily lives of the individual for whom the project
has been developed. A brief nontechnical description
of the project follows with a summary of how the project has improved a person’s quality of life. A photograph of the device or the device modification is usually included. Next, a technical description of the device or device modification is given, with parts specified only if they are of such a special nature that the
project could not otherwise be fabricated. An approximate cost of the project is provided, excluding
personnel costs.
Most projects are described in two pages. However,
the first or last project in each chapter is usually significantly longer and contains more analytic content.
Individuals wishing more information on a particular
design should contact the designated supervising
principal investigator.
Some of the projects described are custom modifications of existing devices, modifications that would be
prohibitively expensive were it not for the student engineers and this NSF program. Other projects are
unique one-of-a-kind devices wholly designed and
constructed by the student for the disabled individual.
Engineering Design
As part of the accreditation process for university engineering programs, students are required to complete
a minimum number of design credits in their course
of study, typically at the senior level.1, 2 Many call this
the capstone course. Engineering design is a course or
series of courses that brings together concepts and
principles that students learn in their field of study. It
involves the integration and extension of material
learned throughout an academic program to achieve
a specific design goal. Most often, the student is exposed to system-wide analysis, critique and evaluation. Design is an iterative decision making process
i n which the student optimally applies previously
learned material to meet a stated objective.
There are two basic approaches to teaching engineering design, the traditional or discipline-dependent
approach, and the holistic approach. The traditional
approach involves reducing a system or problem into
separate discipline-defined components. This approach minimizes the essential nature of the system
as a holistic or complete unit, and often neglects the
interactions that take place between the components.
The traditional approach usually involves a sequen-
Accrediting Board for Engineering and Technology
(1999). Accreditation Policy and Procedure Manual
Effective for Evaluations for the 2000-2001 Accreditation Cycle. ABET: Baltimore, MD.
2 Accrediting Board for Engineering and Technology
(2000). Criteria for Accrediting Engineering Programs.
ABET: Baltimore, MD.
1
Chapter 1: Introduction 3
tial, iterative approach to the system or problem, and
emphasizes simple cause-effect relationship.
A more holistic approach to engineering design is becoming increasingly feasible with the availability of
powerful computers and engineering software packages, and the integration of systems theory, which
addresses interrelationships among system components as well as human factors. Rather than partitioning a project based on discipline-defined components, designers partition the project according to the
emergent properties of the problem.
A design course provides opportunities for problem
solving relevant to large-scale, open- ended, complex,
and sometimes ill-defined systems. The emphasis of
design is not on learning new material. Typically,
there are no required textbooks for the design course,
and only a minimal number of lectures are presented
to the student. Design is best described as an individual study course where the student:
•
Selects the device or system to design
•
Writes specifications
•
Creates a paper design
•
Analyzes the paper design
•
Constructs the device
•
Evaluates the device
•
Documents the design project
Project Selection
In a typical NSF design project, the student meets
with the client (a person with a disability and/or a
client coordinator) to assess needs and to help identify a useful project. Often, the student meets with
many clients before finding a project for which his or
her background is suitable.
After selecting a project, the student then writes a
brief description of the project for approval by the
faculty supervisor. Since feedback at this stage of the
process is vitally important for a successful project,
students usually meet with the client once again to
review the project description.
Projects are often undertaken by teams of students.
One or more members of a team meet with one or more
clients before selecting a project. After project selection, the project is partitioned by the team into logical
parts, and each student is assigned one of these parts.
Usually, a team leader is elected by the team to ensure
that project goals and schedules are satisfied. A team
of students generally carries out multiple projects.
Project selection is highly variable depending on the
university, and the local health care facilities. Some
universities make use of existing technology to develop projects to aid the disabled by accessing databases such as ABLEDATA. ABLEDATA includes information on types of assistive technology, consumer
guides, manufacturer directories, commercially available devices, and one-of-a-kind customized devices.
In total, this database has over 23,000 products from
2,600 manufactures and is available from:
http://www.abledata.com
or
(800) 227-0216
More information about this NSF program is available at:
http://nsf-pad.bme.uconn.edu
Specifications
One of the most important parts of the design process
is determining the specifications, or requirements that
the design project must fulfill. There are many different types of hardware and software specifications.
Prior to the design of a project, a statement as to how
the device will function is required. Operational
specifications are incorporated in determining the
problem to be solved. Specifications are defined such
that any competent engineer is able to design a device
that will perform a given function. Specifications determine the device to be built, but do not provide information about how the device is built. If several engineers design a device from the same specifications,
all of the designs would perform within the given tolerances and satisfy the requirements; however, each
design would be different. No manufacturer's name
or components are stated in specifications. For example, specifications do not list electronic components or even a microprocessor since use of these
components implies that a design choice has been
made.
If the design project involves modifying an existing
device, the modification should be fully described in
as much detail as possible in the specifications. Specific components of the device, such as microprocessors, LEDs, and electronic parts, should be described.
Descriptive detail is appropriate because it defines
the environment to which the design project must interface. However, the specifications for the modification should not provide any information about how
the device is to be built.
Specifications are usually written in a report that
qualitatively describes the project as completely as
possible, and how the project will improve the life of
an individual. It is also important to explain the motivation for carrying out the project. The following issues are addressed in the specifications:
•
What will the finished device do?
•
What is unusual about the device?
Specifications include a technical description of the
device, and all of the facts and figures needed to complete the design project. The following are examples
of important items included in technical specifications.
Electrical Parameters
interfaces
voltages
impedances
gains
power output
power input
ranges
current capabilities
harmonic distortion
stability
accuracy
precision
power consumption
Mechanical
size
weight
durability
accuracy
precision
vibration
Environmental
location
temperature range
moisture
dust
Paper Design and Analysis
The next phase of the design is the generation of possible solutions to the problem based on the specifications, and selection of the optimal solution. This involves creating a paper design for each of the solutions and evaluating performance based on the specifications. Since design projects are open-ended, many
solutions exist, solutions that often require a multidisciplinary system or holistic approach for a successful and useful product. This stage of the design process is typically the most challenging because of the
creative aspect to generating problem solutions.
The specifications previously described are the criteria for selecting the best design solution. In many
projects, some specifications are more important than
others, and trade-offs between specifications may be
necessary. In fact, it may be impossible to design a
project that satisfies all of the design specifications.
Specifications that involve some degree of flexibility
are helpful in reducing the overall complexity, cost
and effort in carrying out the project. Some specifications are absolute and cannot be relaxed.
Most projects are designed in a top-down approach
similar to the approach of writing computer software
by first starting with a flow chart. After the flow chart
or block diagram is complete, the next step involves
providing additional details to each block in the flowchart. This continues until sufficient detail exists to
determine whether the design meets the specifications
after evaluation.
To select the optimal design, it is necessary to analyze
and evaluate the possible solutions. For ease in
analysis, it is usually easiest to use computer software. For example, PSpice, a circuit analysis program, easily analyzes circuit analysis problems.
Other situations require that a potential design project solution be partially constructed or breadboarded
for analysis and evaluation. After analysis of all possible solutions, the optimal design selected is the one
that meets the specifications most closely.
Construction and Evaluation of the Device
After selecting the optimal design, the student then
constructs the device. The best method of construction is to build the device module by module. By
building the project in this fashion, the student is able
to test each module for correct operation before adding it to the complete device. It is far easier to eliminate problems module by module than to build the
entire project, and then attempt to eliminate problems.
Design projects should be analyzed and constructed
with safety as one of the highest priorities. Clearly,
the design project that fails should fail in a safe manner, a fail-safe mode, without any dramatic and harmful outcomes to the client or those nearby. An example of a fail-safe mode of operation for an electrical
device involves grounding the chassis, and using appropriate fuses; thus if ever a 120-V line voltage short
circuit to the chassis should develop, a fuse would
blow and no harm to the client would occur. Devices
should also be protected against runaway conditions
during the operation of the device, and also during
periods of rest. Failure of any critical components in
a device should result in the complete shutdown of
the device.
After the project has undergone laboratory testing, it
is then tested in the field with the client. After the
field test, modifications are made to the project, and
then the project is given to the client. Ideally, the design project in use by the disabled person should be
periodically evaluated for performance and usefulness after the project is complete. Evaluation typically
occurs, however, when the device no longer performs
adequately for the disabled person, and is returned to
the university for repair or modification. If the repair
or modification is simple, a university technician will
handle the problem. If the repair or modification is
more extensive, another design student is assigned to
the project to handle the problem as part of their design course requirements.
Documentation
Throughout the design process, the student is required to document the optimal or best solution to the
problem through a series of required written assignments. For the final report, documenting the design
project involves integrating each of the required reports into a single final document. While this should
be a simple exercise, it is usually a most vexing and
difficult endeavor. Many times during the final
stages of the project, some specifications are changed,
or extensive modifications to the ideal paper design
are necessary.
Most universities also require that the final report be
professionally prepared using desktop publishing
software. This requires that all circuit diagrams and
mechanical drawings be professionally drawn. Illustrations are usually drawn with computer software,
such as OrCAD or AutoCAD.
The two-page reports within this publication are not
representative of the final reports submitted for design course credit, and in fact, are a summary of the
final report. A typical final report for a design project
is approximately 30 pages in length, and includes extensive analysis supporting the operation of the design project. Usually, photographs of the device are
not included in the final report since mechanical and
electrical diagrams are more useful to the engineer to
document the device.
The next three sections illustrate different approaches
to the design course experience. At Texas A&M University, the students work on many small design projects during the two-semester senior design course sequence. At North Dakota State University, students
work on a single project during the two-semester senior design course sequence. At the University of Connecticut, students are involved in distance learning
and a WWW based approach.
Texas A&M University
Engineering Design Experiences
The objective of the NSF program at Texas A&M University is to provide senior bioengineering students
an experience in the design and development of rehabilitation devices and equipment to meet explicit client needs identified at several off campus rehabilitation and education facilities. Texas A&M has participated in the NSF program for six years. The students meet with therapists and/or special education
teachers for problem definition under faculty supervision. This program provides very significant “real
world” design experiences, emphasizing completion
of a finished product. Moreover, the program brings
needed technical expertise that would otherwise not
be available to not-for-profit rehabilitation service
providers. Additional benefits to the participating
students involve their development of an appreciation of the problems of disabled persons, motivation
toward rehabilitation engineering as a career path,
and recognition of the need for more long-term research to address the problems for which today's designs are only an incomplete solution.
Texas A&M University’s program involves a twocourse capstone design sequence, BIEN 441 and 442.
BIEN 441 is offered during the Fall and Summer semesters, and BIEN 442 is offered during the Spring
semester. The inclusion of the summer term allows a
full year of ongoing design activities. Students are allowed to select a rehabilitation design project, or another general bioengineering design project.
The faculty at Texas A&M University involved with
the rehabilitation design course have worked in collaboration with the local school districts, community
rehabilitation centers, residential units of the Texas
Department of Mental Health and Mental Retardation
(MHMR), community outreach programs of Texas
MHMR, and individual clients of the Texas Rehabilitation Commission and Texas Commission for the
Blind.
Appropriate design projects are identified in group
meetings between the staff of the collaborating
agency, the faculty, and the participating undergraduate students enrolled in the design class. In
addition, one student is employed in the design laboratory during the summer to provide logistical support, as well as pursue his or her own project. Each
student is required to participate in the project definition session, which adds to the overall design experience. The meetings take place at the beginning of
each semester, and periodically thereafter as projects
are completed and new ones identified.
The needs expressed by the collaborating agencies often result in projects that vary in complexity and required duration. To meet the broad spectrum of
needs, simpler projects are accommodated by requiring rapid completion, at which point the students
move on to another project. More difficult projects involve one or more semesters, or even a year's effort;
these projects are the ones that typically require more
substantial quantitative and related engineering
analysis. Projects are carried out by individual students or a team of two.
Following the project definition, the students proceed
through the formal design process of brainstorming,
clarification of specifications, preliminary design, review with the collaborating agency, design execution
and safety analysis, documentation, prerelease design review, and delivery and implementation in the
field. The execution phase of the design includes
identifying and purchasing necessary components
and materials, arranging for any fabrication services
that may be necessary, and obtaining photography
for their project reports. Throughout each phase of
the project, the faculty supervises the work, as well as
the teaching assistants assigned to the rehabilitation
engineering laboratory. These teaching assistants are
paid with university funds. The students also have
continued access to the agency staffs for clarification
or revision of project definitions, and review of preliminary designs. The latter is an important aspect of
meeting real needs with useful devices. In addition to
individual and team progress, the rehabilitation engineering group meets as a group to discuss design
ideas and project progress, and to plan further visits
to the agencies.
One challenging aspect of having students be responsible for projects that are eagerly anticipated by the intended recipient is the variable quality of student
work, and the inappropriateness of sending inadequate projects into the field. This potential problem is
resolved at Texas A&M University by continuous project review, and by requiring that the project be revised and reworked until it meets faculty approval.
At the end of each academic year, the faculty and the
personnel from each collaborating agency assess
which types of projects met with the greatest success
in achieving useful delivered devices. This review
has provided ongoing guidance in the selection of future projects. The faculty also maintains continuous
contact with agency personnel with respect to ongoing and past projects that require repair or modification. In some instances, repairs are assigned as shortterm projects to currently participating students. This
provides an excellent lesson in the importance of
adequate documentation.
Feedback from participating students is gathered
each semester using the Texas A&M University student “oppinionaire” form as well as personal discussion. The objective of the reviews is to obtain students’ assessment of the educational value of the rehabilitation design program, the adequacy of the resources and supervision, and any suggestions for
improving the process.
North Dakota State University
Engineering Design Experience
North Dakota State University (NDSU) has participated in this program for six years. All senior electrical engineering students at NDSU are required to
complete a two-semester senior design project as part
of their study. These students are partitioned into
faculty-supervised teams of four to six students. Each
team designs and builds a device for a particular disabled individual within eastern North Dakota or
western Minnesota.
During the early stages of NDSU's participation in
projects to aid the disabled, a major effort was undertaken to develop a complete and workable interface
between the NDSU electrical engineering department
and the community of persons with disabilities to
identify potential projects. These organizations are
the Fargo Public School System, NDSU Student Services and the Anne Carlson School. NDSU students
visit potential clients or their supervisors to identify
possible design projects at one of the cooperating organizations. All of the senior design students visit
one of these organizations at least once. After the site
visit, the students write a report on at least one potential design project, and each team selects a project to
aid a particular individual.
The process of a design project is implemented in two
parts. During the first semester of the senior year,
each team writes a report describing the project to aid
an individual. Each report consists of an introduction to the project establishing the need for the project.
The body of the report describes the device; a complete and detailed engineering analysis is included to
establish that the device has the potential to work.
Almost all of the NDSU projects involve an electronic
circuit. Typically, devices that involve an electrical
circuit are analyzed using PSpice, or another software
analysis program. Extensive testing is undertaken on
subsystem components using breadboard circuit layouts to ensure a reasonable degree of success before
writing the report. Circuits are drawn for the report
using OrCAD, a CAD program. The OrCAD drawings are also used in the second phase of design,
which allows the students to bring a circuit from the
schematic to a printed circuit board with relative ease.
During the second semester of the senior year, each
team builds the device to aid an individual. This first
involves breadboarding the entire circuit to establish
the viability of the design. After verification, the students build a printed circuit board(s) using OrCAD,
and then finish the construction of the project using
the fabrication facility in the electrical engineering
department. The device is then fully tested, and after
approval by the senior design faculty advisor, the device is given to the client. Each of the student design
teams receives feedback throughout the year from the
client or client coordinator to ensure that the design
meets its intended goal.
Each design team provides an oral presentation during regularly held seminars in the department. In the
past, local TV stations have filmed the demonstration
of the senior design projects, and broadcast the tape
on their news show. This media exposure usually results in viewers contacting the electrical engineering
department with requests for projects to improve the
life of another individual, further expanding the impact of the program.
Design facilities are provided in three separate laboratories for analysis, prototyping, testing, printed circuit board layout, fabrication, and redesign/development. The first laboratory is a room for
team meetings during the initial stages of the design.
Data books and other resources are available in this
room.
There are also twelve workstations available for
teams to test their design, and verify that the design
parameters have been meet. These workstations consist of a power supply, waveform generator, oscilloscope, breadboard, and a collection of hand tools.
The second laboratory contains Intel computers for
analysis, desktop publishing and microprocessor
testing. The computers all have analysis, CAD and
desktop publishing capabilities so that students may
easily bring their design projects from the idea to implementation stage. Analysis software supported includes Microsoft EXCEL and Lotus 123 spreadsheets,
PSpice, MATLAB, MATHCAD, and VisSim. Desktop
publishing supported includes Microsoft Word for
Windows, Aldus PageMaker, and technical illustration software via AutoCAD and OrCAD. A scanner
with image enhancement software and a highresolution printer are also available in the laboratory.
The third laboratory is used by the teams for fabrication. Six workstations exist for breadboard testing,
soldering, and finish work involving printed circuit
boards. Sufficient countertop space exists so that
teams may leave their projects in a secure location for
ease in work.
The electrical engineering department maintains a
relatively complete inventory of electronic components necessary for design projects, and when not in
stock, has the ability to order parts with minimal delay. The department also has a teaching assistant assigned to this course on a year round basis, and an
electronics technician available for help in the analysis and construction of the design project.
There were many projects constructed at NDSU (and
probably at many other universities) that proved to be
unsafe or otherwise unusable for the intended individual, despite the best efforts of the student teams
under the supervision of the faculty advisors. These
projects are undocumented.
University of Connecticut Design
Experiences
In August 1998 the Department of Electrical & Systems Engineering (ESE) at UConn, in collaboration
with the School of Hearing and Speech Sciences at
Ohio University, received a five-year NSF grant for
senior design experiences to aid persons with disabilities. This NSF project was a pronounced change
from previous design experiences at UConn that involved in dustry sponsored projects carried out by a
team of student engineers.
In order to provide effective communication between
the sponsor and the student team, a WWW based approach was implemented.3 Under the new scenario,
Enderle, J.D., Browne, A.F., and Hallowell, B. (1998).
A WEB Based Approach in Biomedical Engineering
Design Education. Biomedical Sciences Instrumentation, 34, pp. 281-286.
3
students worked individually on a project and were
divided into teams for weekly meetings. The purpose
of the team was to provide student derived technical
support at weekly meetings. Teams also formed
throughout the semester based on need to solve technical problems. After the problem was solved the
team dissolved and new teams were formed.
Each year, 25 projects are carried out by the students
at UConn. Five of the 25 projects are completed
through collaboration with personnel at Ohio University using varied means of communication currently seen in industry, including video conferencing,
the WWW, telephone, e-mail, postal mailings, and
videotapes.
ESE senior design consists of two required courses,
Electrical Engineering (EE) Design I and II. EE Design
I is a two-credit hour course in which students are introduced to a variety of subjects. These include: working on teams, design process, planning and scheduling (time-lines), technical report writing, proposal
writing, oral presentations, ethics in design, safety, liability, impact of economic constraints, environmental considerations, manufacturing and marketing. Each student in EE Design I:
•
Selects a project to aid a disabled individual
after interviewing a person with disabilities;
•
Drafts specifications;
•
Prepares a project proposal;
•
Selects an optimal solution and carries out a
feasibility study;
•
Specifies components, conducts a cost analysis and creates a time-line; and
•
Creates a paper design with extensive modeling and computer analysis.
EE Design II is a three-credit hour course following
Design I. This course requires students to implement
a design by completing a working model of the final
product. Prototype testing of the paper design typically requires modification to meet specifications.
These modifications undergo proof of design using
commercial software programs commonly used in industry. Each student in EE Design II:
•
Constructs and tests a prototype using modular components as appropriate;
•
Conducts system integration and testing;
•
Assembles final product and field-tests the
device;
•
Writes final project report;
•
Presents an oral report using PowerPoint on
Senior Design Day; and
•
Gives the device to the client after a waiver is
signed.
Course descriptions, student project homepages and
additional
resources
are
located
at
http://www.ee.uconn.edu/~design/.
The first phase of the on-campus projects involves
creating a database of persons with disabilities and
then linking the student with a person with a disability. The A.J. Pappanikou Center provided a database
with almost 60 contacts and a short description of the
disabilities in MS Access. The in volvement of the
Center was essential for the success of the program.
The A.J. Pappanikou Center is Connecticut’s University Affiliated Program (UAP) for disabilities studies.
As such, relationships have been established with the
Connecticut community of persons affected by disabilities, including families, caregivers, advocacy and
support groups and, of course, persons with disabilities themselves. The Center serves as the link between
the person in need of the device and the ESE Design
course staff. The Center has established ongoing relationships with Connecticut’s Regional Educational
Service Centers, the Birth to Three Network, the Connecticut Tech Act Project, and the Department of Mental Retardation. Through these contacts, the Center
facilitates the in teraction between the ESE students,
the client coordinators (professionals providing support services, such as the speech-language pathologists, physical and occupational therapists), the individuals with disabilities (clients), and clients’ families.
The next phase of the course involves students’ selection of projects. Using the on-campus database, each
student selects two clients to interview. The student
and a UConn staff member meet with the client
and/or client coordinator to identify a project that
would improve the quality of life for the client. After
the interview, the student writes a brief description
for each project. Almost all of the clients interviewed
have multiple projects. Project descriptions include:
contact information (client, client coordinator, and
student name) and a short paragraph describing the
problem. These reports are collected, sorted by topic
area, and put into a Project Notebook. In the future,
these projects will be stored in a database accessible
from the course server for ease in communication.
Each student then selects a project from a client that
he/she has visited, or from the Project Notebook. If
the project selected was from the Project Notebook, the
student visits the client to further refine the project.
Because some projects do not involve a full academic
year to complete, some students work on multiple
projects. Students submit a project statement that describes the problem, including a statement of need,
basic preliminary requirements, basic limitations,
other data accumulated, and important unresolved
questions.
Specific projects at Ohio University are established
via distance communication with the co-principal investigator, who consults with a wide array of service
providers and potential clients in the Athens, Ohio
region.
The stages of specification, project proposal, paper
design and analysis, construction and evaluation,
and documentation are carried out as described earlier in the overview of engineering design.
To facilitate working with sponsors, a WWW based
approach is used for reporting the progress on projects. Students are responsible for creating their own
WWW sites that support both html and pdf formats
with the following elements:
•
Introduction for layperson
•
Resume
•
Weekly reports
•
Project statement
•
Specifications
•
Proposal
•
Final Report
Weekly Schedule
Weekly activities in EE Design I consist of lectures,
student presentations and a team meeting with the
instructor. Technical and non-technical issues that
impact the design project are discussed during team
meetings.
Students
also
meet
with
clients/coordinators at scheduled times to report on
progress.
Each student is expected to provide an oral progress
report on his or her activity at the weekly team meeting with the instructor, and record weekly progress in
a bound notebook and on the WWW site. Weekly report structure for the WWW includes: project identity,
work completed during the past week, current work
within the last day, future work, status review and at
least one graphic. The client and/or client coordinator uses the WWW reports to keep up with project so
that they can provide input on the progress. Weekly
activities in EE Design II include team meetings with
the course instructor, oral and written progress re-
ports, and construction of the project. As before, the
WEB is used to report project progress and communicate with the sponsors.
For the past two years, the student projects have been
presented at the annual Northeast Biomedical Engineering Conference.
Other Engineering Design
Experiences
Experiences at other universities participating in this
NSF program combine many of the design program
elements that are presented for Texas A&M University and North Dakota State University. Still, each
university’s program is unique. In addition to the design process elements already described, the State
University of New York at Buffalo under the direction
of Dr. Joseph Mollendorf, requires that each student
go through the preliminary stages of a patent application. Naturally, projects worthy of a patent application are actually submitted. Thus far, a patent was issued for a "Four-Limb Exercising Attachment for
Wheelchairs" and another patent has been allowed
for a "Cervical Orthosis."
CHAPTER 2
EDUCATIONAL OUTCOMES
ASSESSMENT:IMPROVING DESIGN
PROJECTS TO AID PERSONS WITH
DISABILITIES
Brooke Hallowell
Of particular interest to persons interested in the engineering education are the increasingly outcomes focused standards of the Accrediting Board for Engineering and Technology (ABET).4 This chapter is offered as an introduction to the ways in which improved foci on educational outcomes may lead to: (a)
improvements in the learning of engineering students, especially those engaged in design projects to
aid persons with disabilities, and consequently, (b)
improved knowledge, design and technology to benefit individuals in need.
such as North Central, Middle States, or Southern Associations of Colleges and Schools, and professional
accrediting bodies, including ABET, is mandated by
CHEA, and thus is a requirement for all regional as
well as professional accreditation. Consequently,
candidates for accreditation are required to demonstrate plans for assessing educational outcomes, and
evidence that assessment results have led to improved of teaching and learning and, ultimately, better preparation for entering the professions. Accrediting bodies have thus revised criteria standards for accreditation with greater focus on the “output” that
students can demonstrate and less on the “input”
they are said to receive.5
Brief History
As part of a movement for greater accountability in
higher education, US colleges and universities are
experiencing an intensified focus on the assessment
of students’ educational outcomes. The impetus for
outcomes assessment has come most recently from
accrediting agencies. All regional accrediting agencies receive their authority by approval from the
Council for Higher Education Accreditation (CHEA),
which assumed this function from the Council on
Recognition of Postsecondary Accreditation (CORPA)
in 1996. The inclusion of outcomes assessment standards as part of accreditation by any of these bodies,
“Meaningful” Assessment
Practices
Because much of the demand for outcomes assessment effort is perceived, at the level of instructors, as a
bureaucratic chore thrust upon them by administrators and requiring detailed and time-consuming
documentation, there is a tendency for many faculty
Hallowell, B. & Lund, N. (1998). Fostering program
improvements through a focus on educational outcomes. In Council of Graduate Programs in Communication Sciences and Disorders, Proceedings of the
nineteenth annual conference on graduate education,
32-56.
5
4
13
members to avoid exploration of effective assessment
practices. Likewise, many directors of academic departments engage in outcomes assessment primarily
so that they may submit assessment documentation to
meet bureaucratic requirements. Thus, there is a tendency in many academic units to engage in assessment practices that are not truly “meaningful”.
Although what constitutes an “ideal” outcomes assessment program is largely dependent on the particular program and institution in which that program is to be implemented, there are at least some
generalities we might make about what constitutes a
“meaningful” program. For example:
An outcomes assessment program perceived by
faculty and administrators as an imposition of bureaucratic control over what they do, remote from
any practical implications… would not be considered “meaningful.” Meaningful programs, rather,
are designed to enhance our educational missions
in specific, practical, measurable ways, with the
goals of improving the effectiveness of training
and education in our disciplines. They also involve all of a program’s faculty and students, not
just administrators or designated report writers.
Furthermore, the results of meaningful assessment
programs are actually used to foster real modifications in a training program.6
Outcomes Associated with
Engineering Design Projects
Despite the NSF’s solid commitment to engineering
design project experiences, and widespread enthusiasm about this experiential approach to learning and
service, there is a lack of documented solid empirical
support for the efficacy and validity of design project
experiences and the specific aspects of implementing
those experiences. Concerted efforts to improve learning, assessment methods and data collection concerning pedagogic efficacy of engineering design project
experiences will enhance student learning while
benefiting the community of persons with disabilities.
Hallowell, B. (1996). Innovative Models of Curriculum/Instruction: Measuring Educational Outcomes.
In Council of Graduate Programs in Communication
Sciences and Disorders, Proceedings of the Seventeenth Annual Conference on Graduate Education,
37-44.
6
Agreeing on Terms
There is great variability in the terminology used to
discuss educational outcomes. How we develop and
use assessments matters much more than our agreement on the definitions of each of the terms we might
use to talk about assessment issues. Still, for the sake
of establishing common ground, a few key terms are
highlighted here.
Formative and Summative Outcomes
Formative outcomes indices are those that can be
used to shape the experiences and learning opportunities of the very students who are being assessed.
Some examples are surveys of faculty regarding current students’ design involvement, on-site supervisors’ evaluations, computer programming proficiency
evaluations, and classroom assessment techniques.7
The results of such assessments may be used to characterize program or instructor strengths and weaknesses, as well as to foster changes in the experiences
of those very students who have been assessed.
Summative outcomes measures are those used to
characterize programs (or college divisions, or even
whole institutions) by using assessments intended to
capture information about the final products of our
programs. Examples are student exit surveys, surveys of graduates inquiring about salaries, employment, and job satisfaction, and surveys of employers
of our graduates.
The reason the distinction between these two types of
assessment is important is that, although formative
assessments tend to be the ones that most interest our
faculty and students and the ones that drive their
daily academic experiences, the outcomes indices on
which most administrators focus to monitor institutional quality are those involving summative outcomes. It is important that each of academic unit
strive for an appropriate mix of both formative and
summative assessments.
Cognitive/Affective/Performative Outcome Distinctions
To stimulate our clear articulation of the specific outcomes targeted within any program, it is helpful to
have a way to characterize different types of out-
Angelo, T. A., & Cross, K. P. (1993). Classroom assessment techniques: A handbook for college teachers. San Francisco: Jossey-Bass.
7
Chapter 2: Educational Outcomes Assessment: Improving Design Projects To Aid Persons With Disabilities 15
comes. Although the exact terms vary from context to
context, targeted educational outcomes are commonly
characterized as belonging to one of three domains:
cognitive, affective, and performative. Cognitive outcomes are those relating to intellectual mastery, or
mastery of knowledge in specific topic areas. Most of
our course-specific objectives relating to a specific
knowledge base fall into this category. Performance
outcomes are those relating to a student’s or graduate’s accomplishment of a behavioral task. Affective
outcomes relate to personal qualities and values that
students ideally gain from their experiences during a
particular educational and training program. Examples are appreciation of various racial, ethnic, or linguistic backgrounds of individuals, awareness of biasing factors in the design process, and sensitivity to
ethical issues and potential conflicts of interest in
professional engineering contexts.
forts. Additional factors that might give faculty the
incentive to get involved in enriching assessment
practices include:
The distinction among these three domains of targeted educational outcomes is helpful in highlighting
areas of learning that we often proclaim to be important but that we do not assess very well. Generally,
we are better at assessing our targeted outcomes in
the cognitive area, for example, with in-class tests and
papers, than we are with assessing the affective areas
of multicultural sensitivity, appreciation for collaborative teamwork, and ethics. Often, our assessment of
performative outcomes is focused primarily on students’ design experiences, even though our academic
programs often have articulated learning goals in the
performative domain that might not apply only to design projects.
With the recent enhanced focus of on educational outcomes in accreditation standards of ABET, and with
all regional accrediting agencies in the Unites States
now requiring extensive outcomes assessment plans
for all academic units, it is increasingly important
that we share assessment ideas and methods among
academic programs. It is also important that we
ensure that our assessment efforts are truly meaningful, relevant and useful to our students and faculty.
Faculty Motivation
A critical step in developing a meaningful educational outcomes program is to address directly pervasive issues of faculty motivation. Faculty resistance is
probably due in large part to the perception that outcomes assessment involves the use of educational
and psychometric jargon to describe program indices
that are not relevant to the everyday activities of faculty members and students. By including faculty,
and perhaps student representatives, in discussions
of what characterizes a meaningful assessment
scheme to match the missions and needs of individual programs, and by agreeing to develop outcomes
assessment practices from the bottom up, rather than
in response to top-down demands from administrators and accrediting agencies, current skeptics on our
faculties are more likely to engage in assessment ef-
Consideration of outcomes assessment work as
part of annual merit reviews; provision of materials, such as sample instruments; or resources,
such as internet sites; to simplify the assessment
instrument design process; demonstrate means
by which certain assessments, such as student
exit or employer surveys, may be used to [a] program’s advantage in negotiations with … administration (for example, to help justify funds for
new equipment, facilities, or salaries for faculty
and supervisory positions); and notice and reward curricular modifications and explorations
of innovative teaching methods initiated by the
5
faculty in response to program assessments.
The next chapter serves as an invitation to readers of
this book to join in collaborative efforts to improve design experiences, student learning, and design products through improved assessment practices. Future
annual publications on the NSF-sponsored engineering design projects to aid persons with disabilities
will include input from students, faculty, supervisors,
and consumers on ways to enhance associated educational outcomes in specific ways. The editors of
this book look forward to input from the engineering
education community for dissemination of further information to that end.
CHAPTER 3
AN INVITATION TO COLLABORATE IN
USING ASSESSMENT TO IMPROVE
DESIGN PROJECTS
Brooke Hallowell
In Chapter 2, we discussed educational outcomes assessment, emphasizing ways in which clearer foci on
educational outcomes may lead to improvements in
the learning of engineering students, and, consequently, improved knowledge, design and technology
to benefit individuals in need. We described concerted efforts among accrediting agencies, including
the Accrediting Board for Engineering and Technology (ABET), to improve the accountability of educational institutions through improved assessment
practices. We discussed how a “meaningful” emphasis on educational outcomes helps overcome bureaucratic hurdles in academe, and enhances our educational missions in specific, practical, measurable
ways by improving the effectiveness of training and
education. This chapter serves as an invitation to
readers to join in collaborative efforts to enrich meaningful educational outcomes assessment efforts associated with NSF-sponsored design projects to aid persons with disabilities.
establishment of objectives and criteria, synthesis,
analysis, construction, testing, and evaluation” (p.
11). Furthermore, according to ABET, specific targeted outcomes associated with engineering design
projects should include: development of student creativity, use of open-ended problems, development and
use of modern design theory and methodology, formulation of design problem statements and specifications, consideration of alternative solutions, feasibility considerations, production processes, concurrent
engineering design, and detailed system descriptions.
The accrediting board additionally stipulates that it is
essential to include a variety of realistic constraints,
such as economic factors, safety, reliability, aesthetics,
ethics, and social impact. ABET’s most recent, revised list of similar targeted educational outcomes is
presented in the Appendix. We encourage educators,
students and consumers to consider the following
questions:
A look at ABET’s requirements for the engineering
design experiences in particular8 may give us further
direction in areas that are essential to assess in order
to monitor the value of engineering design project experiences. For example, the following are considered
“fundamental elements” of the design process: “the
8
17
•
Are there outcomes, in addition to those
specified by ABET, that we target in our roles
as facilitators of design projects?
•
Do the design projects of each of the students
in NSF-sponsored programs incorporate all
of these features? How may we best characterize evidence that students engaged in Projects to Aid Persons with Disabilities effectively attain desired outcomes?
•
•
Are there ways in which students’ performance within any of these areas might be more
validly assessed?
•
Surveys of faculty regarding student
design competence
•
Evaluation of writing samples
How might improved formative assessment
of students throughout the design experience
be used to improve their learning in each of
these areas?
•
Evaluation of presentations
•
Evaluation of collaborative learning
and team-based approaches
•
Evaluation of problem-based learning
•
Employer surveys
•
Peer evaluation; e.g., of leadership or
group participation
Readers interested in addressing such questions are
encouraged to send comments to the editors of this
book. We are particularly interested in disseminating, through future publications, specific assessment
instruments that readers find effective in evaluating
targeted educational outcomes in NSF-sponsored engineering design projects. Basic terminology related
to pertinent assessment issues is presented in Chapter 2. Cognitive, performative, and affective types of
outcomes are reviewed briefly here, along with lists of
the types of assessments that might be shared among
those involved in engineering design projects.
Cognitive outcomes are those relating to intellectual
mastery, or mastery of knowledge in specific topic areas. Some examples of these measures are:
•
Comprehensive exams
•
Items embedded in course exams
•
Pre-post
added”
•
Design portfolios
•
Student self evaluation of learning
during a design experience
•
Alumni surveys
•
Employer surveys
tests
to
assess
“value
Performative outcomes are those relating to a
student’s or graduate’s accomplishment of a
behavioral task. Some performance measures
include:
•
Evaluation of graduates’ overall design experience
•
Mastery of design procedures or
skills expected for all graduates
•
Student evaluation of final designs,
or of design components
Affective outcomes relate to personal qualities and
values that students ideally gain from their educational experiences. These may include:
•
Student journal reviews
•
Supervisors’ evaluation of students’
interactions with persons with disabilities
•
Evaluations of culturally-sensitive
reports
•
Surveys of attitudes or satisfaction
with design experiences
•
Interviews with students
•
Peers’,
supervisors’,
evaluations
employers’
We welcome contributions of relevant formative and
summative assessment instruments, reports on assessment results, and descriptions of assessment programs and pedagogical innovations that appear to be
effective in enhancing design projects to aid persons
with disabilities.
Please send queries or submissions for consideration
to:
Brooke Hallowell, Ph.D.
School of Hearing and Speech Sciences
Lindley Hall 208
Ohio University
Athens, OH 45701
Chapter 3: An Invitation To Collaborate In Using Assessment To Improve Design Projects 19
APPENDIX: Desired educational outcomes as articulated in ABET’s new “Engineering Criteria 2000” (Criterion 3,
Program Outcomes and Assessment)
Engineering programs must demonstrate that their graduates have:
(a) an ability to apply knowledge of mathematics, science, and engineering
(b) an ability to design and conduct experiments, as well as to analyze and interpret data
(c) an ability to design a system, component, or process to meet desired needs
(d) an ability to function on multi-disciplinary teams
(e) an ability to identify, formulate, and solve engineering problems
(f) an understanding of professional and ethical responsibility
(g) an ability to communicate effectively
(h) the broad education necessary to understand the impact of engineering solutions in a global and societal
context
(i) a recognition of the need for, and an ability to engage in life-long learning
(j) a knowledge of contemporary issues
(k) an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice
(p. 38-39).
Accrediting Board for Engineering and Technology (2000). Criteria for Accrediting Engineering Programs. ABET:
Baltimore, MD.
9
CHAPTER 4
ARIZONA STATE UNIVERSITY
College of Engineering and Applied Sciences
Bioengineering Program
Department of Chemical, Bio & Materials Engineering
Tempe, Arizona 85287-6006
Principal Investigators:
Gary T. Yamaguchi, Ph.D. (602) 965-2268
[email protected]
Jiping He, Ph.D. (602) 965-0092
21
VOLUNTARY-OPENING TRANSRADIAL
PROSTHESIS FOR USE WITH WEIGHT TRAINING
EQUIPMENT
Designer: Jill M. Vandenburg
Client: Kristin Varon
Graduate Student: Chad Kennedy
Clinician: James M. Duston, Prosthetic Orthotic Associates, Scottsdale, AZ
Supervising Professor: Gary T. Yamaguchi, Ph.D.
Arizona State University
Tempe, AZ 85287-6006
INTRODUCTION
An upper extremity weight training prosthesis was
designed for a client who was born without her right
wrist, hand, and the majority of her forearm. The
prosthesis enables the client to grasp the weight lifting bar at the beginning of the exercise, and to release
it at the end of the exercise, without any help from the
left hand. The device is a voluntary-opening prosthe-
sis that provides the client with a standard cable interface with which she is familiar.
SUMMARY OF IMPACT
A college student born without her right wrist, hand,
and the majority of her forearm, required a prosthetic
device to enable her to utilize weight training equipment. Her goal was to exercise the muscles of her
Figure 4.1. Photograph of the Transradial Prosthesis for Use with Weight Training Equipment.
Chapter 4: Arizona State University 23
right upper arm, shoulder, and back.
The prosthesis was designed to be used with pulling
devices, including lateral pull-down and rowing machines. It could potentially be used for pushing exercises, including bench and incline press and various
dumbbell exercises, by designing additional custom
terminal devices.
TECHNICAL DESCRIPTION
This design incorporates a gated hook. A heavy-duty
cable runs from the gate on the terminal device, or
hand portion of the prosthesis, to a loose strap on an
upper body harness. The gate of the terminal device
opens when a maximum amount of tension is exerted
on the cable. This occurs when the client performs
various upper body motions, including biscapular
abduction or humeral flexion. As the client relaxes
her arm, the tension in the cable decreases and the
gate closes. As she reaches out for the weight lifting
bar, the terminal device opens, allowing her to clamp
onto the bar. As she performs the weight lifting motion, the lever arm remains closed, keeping the bar
from slipping out of the terminal device. When she
extends her arm back to her original starting position,
the tension in the cable increases and the lever arm
opens, allowing her to release the prosthesis from the
bar. This also allows her to quickly release the bar in
the event of a problem.
The primary design specifications included: (1) the
client can manually affix the prosthesis to the residual limb with only one hand; (2) the correct muscle
groups are exercised during the weight lifting motion;
(3) the device can withstand high normal and shear
stresses under a wide range of loads; (4) the prosthesis mass must match, as closely as possible, the mass
of the client’s left forearm, wrist, and hand; (5) the
length of the prosthesis should equal the length from
the end of the client’s residual limb to the metacarpophalangeal joints on a closed hand; (6) the device
should maximize the range of motion of the client’s
elbow joint; and (7) it should be easy to maintain and
repair.
The prosthesis is comprised of six different parts: the
terminal device (hand), wrist unit, forearm unit, elbow socket, harness, and cable system. The design
and function of the terminal device is similar to that
of a mountain climbing carabiner, consisting of a “C”
shaped outer bar and a spring-loaded manually
opening “gate” which closes the opening of the C
Figure 4.2. Close-up of the Transradial Prosthesis
for Use with Weight Training Equipment.
(Figures 4.3, 4.4, and 4,5). The outer C and gate of the
terminal device are composed of aluminum alloy
7175-T66 while the lever arm and cable pins are made
of stainless steel. The bottom of the terminal device
has a ½” aluminum stud, which is used to attach the
terminal device to the wrist unit. The C and stud
were machined out of a single block of aluminum for
strength. To enhance the wear resistance of the device, the aluminum components were anodized after
fabrication and a rubber lining was added to the internal and external contact areas.
The wrist unit is a standard aluminum upper extremity prosthetic component from Hosmer-Dorrance. It
connects the terminal device and the forearm unit and
allows the user to position the terminal device prior to
use. There is constant friction between the wrist unit
and the terminal device during exercise.
The forearm unit and elbow socket were custom made
to fit the client’s residual limb. The forearm unit was
made of a lamination, comprised of two layers of carbon braid sock, two layers of Kevlar, and seven layers
of ny-glass lay-up. The elbow socket is comprised of
two separate parts: the silicone socket and the hard
socket. The silicone socket is made of a siliconeplatinum gel that is covered with an external, nylon
liner. It is a standard component from Ossur, a company in Iceland. An impression of the client’s residual limb and elbow was made using a casting material, and the hard portion of the socket was created
from this impression. The resulting socket shell is
composed of serlin and is covered with Pedalin foam
and the forearm unit lamination.
The harness is a standard upper extremity prosthetic
component ordered from Hosmer-Dorrance. The harness is a configuration of Dacron straps, which wrap
around the user’s upper body and attach to the remainder of the prosthesis via a cable and cable housing. It serves two purposes: it helps to secure the remainder of the prosthesis onto the residual limb and
upper arm, and it provides a mechanism for voluntary operation of the terminal device via upper body
motion.
The cable system is used to provide voluntary control
of the terminal device. A steel cable is attached from
the terminal device to a loose strap on the harness, the
control attachment strap. Between the terminal device and the harness, the cable passes through two
aluminum housing units attached to the forearm unit.
The cable housing units maintain the cable at a constant length throughout the range of motion of the elbow joint, help to secure the cable system to the prosthesis, and also align the cable toward its attachment
location on the terminal device.
The device has been tested using the weight training
equipment. It functions effectively for exercises that
involve pulling (from an arm extended position to a
flexed position). The client also uses the prosthesis to
perform several other exercises not initially planned.
These include push-ups, one-arm dumbbell rows,
and shoulder shrugs. By wrapping a set of ankle or
wrist weights around the terminal device, she may
also perform both front and lateral shoulder raises.
However, unless further adaptations are made, the
device does not work as well in these other exercise
modalities.
The client has used the device for lateral pull-downs
and rowing, three times per week for six months. She
suggests that the inner liner be made of a stiffer plastic for greater durability.
The final cost of the terminal device was approximately $1490. The socket and forearm orthosis was
made with the assistance of Prosthetic Orthotic Associates of Scottsdale, AZ.
ITEM 8
ITEM 3
ITEM 4
ITEM 1
ITEM 2
ITEM 7
ITEM 5
ITEM 6
ITEM
1
2
3
4
5
6
7
8
DESCRIPTION
BASE
LEVER ARM
CABLE PIN
LEVER ARM PIN
SPRING
SPRING
SET SCREW
SET SCREW
SHEET
2&3
4
5
5
6
6
NOTE 1
NOTE 1
NOTES:
1. MAT'L:
ITEM 1 & ITEM 2: ALUMINUM ALLOY, 7175-T66
ITEM 3 & ITEM 4: STAINLESS STEEL
ITEM 5: STD. STOCK SPRING
ITEM 7: STD. SET SCREW, 2-56 X 2.54 LONG
ITEM 8: STD. SET SCREW, 1/4-20 X 3.18 LONG
2. FINISH
ITEM 1 & ITEM 2: HARD ANODIZE, BLACK, PER MIL-A-8625F
3. DEBURR ALL SHARP EDGES AFTER MACHINING.
4. ALL HOLES ARE TO BE MASKED OR PLUGGED PRIOR TO ANODIZE.
Figure 4.3. Assembly Drawing of Terminal Device.
60.00
10.00 TYP.
30.00
30.00
R
SEE VIEW B
SHEET 3
2X 10.00
13.00
125.00
2X 34 DEG.
4.00
8.00
62.50
2X 10.00
10.00
7.67
24.00
SEE VIEW C
SHEET 3
2.0
SEE VIEW A
SHEET 3
80.00
1/2-20 UNF-2A
15.00
40.00
Figure 4.4. Dimensions of the Terminal “C” Device.
18.0
R3.57
SECTION A-A
4X 5.00
R3.18 TYP
2X 7.00
2X 4.50
2X SLIDE FIT FOR 3.96 DIA PIN
4X 2-56 UNC-2B X 5.50 DEEP
2X 2.25
2X 4.50
2.38 DIA.
10.00
10.00
10.00
20.00
2X 2.25
A
A
2X 4.50
2X 7.00
15.00
2X 4.50
21.07
8.50
70.00
Figure 4.5. Dimensions of the Manually Operated “Gate” of the Terminal Device.
5.00
SHOWER CHAIR FOR A CLIENT WITH DE
SANTIS CACHIONE
Designer: Kevin Cordes
Client: Angel Bueno
Tempe, AZ 85287-6006
INTRODUCTION
This project’s objective was to create a shower chair
which would ease bathing and transfers to and from
the shower for a client with an extremely rare condition, de santis cachione. This condition has been diagnosed approximately 20 times since its discovery in
1932. It has many of the common traits of cerebral
palsy, except that de santis cachione causes a progressive deterioration in condition.
The client once had nearly full function in all modalities, but his condition has steadily progressed so that,
at his current age of 26, he has lost his ability to ambulate, speak, and see. He still responds to light and
darkness, and to auditory stimuli. The disease is now
affecting his hearing, and has caused a skin disorder
known as xenoderma pigmentosa, which causes skin
damage after exposure to direct sunlight. Due to the
severity of the client’s condition, he is supervised continuously.
SUMMARY OF IMPACT
Before the design of this project, the client’s mother
carried him from his wheelchair in the living room to
a plastic patio chair used in the shower. During the
shower, his muscles would relax, causing him to
slide out of the chair, or lean to one side.
The shower chair was designed to hold the client upright comfortably in the shower, at an optimal height
for his mother to bathe him. It allows for easy and
safe transfer and meets bathroom size constraints.
The technical specifications of the shower chair were
derived primarily from ergonomic factors. The cli-
Figure 4.6. Angel in his Shower Chair with his
Mother and Graduate Student Coordinator
ent’s weight and body dimensions determined the
seat area of the chair, while the transfer and bathroom
space limitations were used to determine much of the
chair base design (Figure 4.7). For safety reasons, the
design was tested with individuals weighing about
two and one-half times the client’s weight of 60 lbs. A
four-wheel base configuration was chosen for ease of
rolling and to prevent tipping. The 3-inch diameter
caster wheels easily negotiate the rugs, sill, and
threshold of the home and bathroom, and are rated at
150 psi, or nearly 10 times the expected loading. The
frame is made from one-inch outer diameter T6061
aluminum tubing with a 1/8-inch wall thickness. All
frame joints were welded, except for the pin connections for the adjustment rod. To adjust the reclining
angle, the person giving the user a shower uses the
adjustable pin positions on the adjustment rod to rotate the chair from an upright sitting position to one
reclined at 45°. An adjustable spring/damper device
connected between the base and the rotating seat controls the rate of rotation. The device resists motion in
both directions, and can be set to give variable resistance using a screw setting. An adjustable 2-inch nylon-webbing belt with a Delrin clasp is used to secure
the user and is positioned across the chest, away from
his feeding tube and button. The seating material is
made from a polyester mesh typically used for outdoor furniture. It is mildew-resistant and porous
enough to allow water to pass through it, while retaining enough strength to support the client’s
weight. The material was attached to the frame by
stretching it around the tubing and securing it with
aluminum POP rivets and washers.
Since the shower chair was to be used in a corrosive
environment, all component pieces, fasteners, etc.
were made of corrosion resistant materials. To improve the appearance of the chair, the aluminum
frame was coated with bright blue Hammerite paint.
Though every effort was made to make the chair stable and structurally sound, it is assumed that the user
is under supervision at all times.
The overall material costs were estimated at $141.58.
Figure 4.7. Client and his Shower Chair in the Shower Enclosure.
A FLY CASTING ORTHOSIS FOR A PATIENT
WITH QUADRIPLEGIA
Designer: Jason Lieb
Client: Don Price, Fishing Has No Boundaries, AZ Chapter
Tempe, AZ 85287-6006
INTRODUCTION
A prototype fly-fishing orthosis was designed for use
by a patient with mild quadriplegia. The device was
designed to allow him to perform a proper casting
stroke, control slack line, and reel - - all motions that
are necessary for fly fishing. The person for whom
the device was designed has no independent finger
movement or grip strength, but he is able to move his
arms well. Special devices were needed to attach the
rod to the user’s hand, to catch the slack line coming
from the first “stripper” line guide, to grip the line
during the cast, and to release the line at the end of
the casting stroke. Combinations of mountable support devices, alternative reels, and wrist brace attachments were considered before a final design concept was selected. The final prototype consists of two
polypropylene orthoses fitted to the user’s hands and
arms. The left hand orthosis is strapped onto the
forearm and hand and has a hole to allow turning of
the reel handle and a “finger” to allow hooking,
grasping, and releasing of slack line. The right arm
orthotic is strapped to the forearm and hand and
tightly grips a standard cork fly rod handle.
SUMMARY OF IMPACT
The client is presently one of the cofounders of the
Arizona Chapter of “Fishing Has No Boundaries”, an
organization dedicated to introducing persons with
disabilities to fishing and enabling them to participate in the sport. While electric reels and reeling devices, spring loaded casting devices, specialized tires
for “off-road wheelchairing” have been developed to
enable people with quadriplegia to fish with conventional fishing tackle, no known devices enable such
persons to fish with a fly rod and fly line. Instead of
performing only a long forward casting stroke with a
Figure 4.8. Client Testing the Fly-Casting Orthosis.
heavy weight and light line, as in conventional fishing, fly fishing requires one to perform both a backward stroke (the backcast) and a forward stroke. Because good fly casting only requires a short backward
and short forward stroke that are timed appropriately, it was felt that people with quadriplegia could
participate in fly fishing. People with mild quadriplegia typically have enough upper body mobility
and voluntary arm movement to support the movements involved in fly fishing. The most difficult thing
to teach a non-disabled individual is not to flex the
wrists backward during the backcast. With an orthosis that prevents backward wrist flexion, people with
quadriplegia would not have to unlearn this highly
unproductive movement. With further development
and appropriate modifications, this prototype might
be made as a commercial device that could be made
available to other people with quadriplegia.
The final design of the fly-fishing device consists of a
right and left orthotic (Figure 4.9) and a slightly modified reel handle. The left hand orthotic straps onto
the hand and wrist and has two attachment functions: 1) to grasp and pull in slack line, 2) to grasp
the handle and turn the reel when fighting fish or
reeling in slack line. The grasping and pulling functions are accomplished with a forked extension,
shown in Figure 4.9. The reeling is accomplished by
way of a milled slot and 7/16” hole built into the
palm area which mates with the reel handle. The slot
enables the user to find the reel handle easily so that
once the reel handle is located within the hole the
spool can be turned. The plastic reel handle was extended slightly for more accessible use. The opposing
orthosis straps onto the palm of the right (casting)
hand. This device cradles the rod in a thermal cork
lined inset, shown in Figure 4.9. The polypropylene
material flexes and the cork lining compresses to accommodate the many rod handles available on the
market. 1-inch nylon webbing straps with Velcro closures and steel rings were attached to secure the orthosis to the rod and to further secure the connection
between the orthosis and the hand. The interiors of
both orthotics are lined with Alliplast, a soft foam-like
material, for comfort. Prototypes of the design were
made at the Prosthetic Orthotic Associates facilities in
Scottsdale, Arizona. Casts were made of the right and
left arms, with plaster bandages cut away, stapled
back together, and used to form plaster molds of the
arms. The dried and shaped molds were used to
shape the preheated Alliplast liners and polypropylene sheets. The polypropylene was then sealed and
vacuumed to pull the plastic tight around the mold.
Once cooled, the shapes were further refined and
smoothed to the desired shape. Thermal cork was
heated and glued to the right orthotic and then
shaped to grip the handle of a standard fly rod. During operation, the user pulls the slack out of the line
by hooking the line or sliding the fork prongs around
the line, slightly twisting, and pulling down. When
enough slack is pulled out, the user holds the line by
pressing the fork with the line down into his lap.
Slack is released when necessary. As with nondisabled individuals, learning these movements requires practice before actual use on the stream. Although designed to fit most individuals, each individual's mobility and skills determines how effective
the device is for fly-fishing. It was found that the client did not actually need the left hand orthosis, as he
was able to loosely hold the line with his left hand, an
essential component to successful fly casting.
Although the concept was effective, the right hand orthosis was found to be a bit bulky and a new design
is being considered. Also, it was determined that because of the client’s weakness, a specially designed
fly rod that is shorter and lighter in weight would
make it easier for him to accelerate and decelerate.
Total costs for the prototype device were estimated at
$120.
Figure 4.9. The Left Hand Orthosis (Bottom) Reel Handle, Attached to a Standard Fly Rod Using a Friction Fitting,
Two D Rings, and Velcro Straps.
AN EXERCISE/RANGE-OF-MOTION BIKE FOR A
PATIENT WITH PARAPLEGIA
Designer: Tariq Al-lawati
Client: Mike Davis, ASU
Tempe, AZ 85287-6006
INTRODUCTION
An exercise/range-of-motion (Ex/ROM) bike was designed for a person with paraplegia. The client requested a hand-driven device that would move his
legs repeatedly through a wide range of motion. He
had found that ranging his joints was useful because
it reduces contractures and spasticity. The major design components included a hand-controlled drive
sprocket, a gear driven leg follower sprocket, a sliding
seat, ankle and foot supports, and the overall frame.
SUMMARY OF IMPACT
The aim of this design was to allow an efficient way
for an adult with paraplegia to stretch and range his
legs by cranking with his arms. The need for such a
device is not limited to the individual for whom it
was designed, but extends to other people with paraplegia, as well as to others requiring passive motion.
Currently, similar devices are being used to rehabilitate many individuals with various lower limb disabilities in the U.S. Most of these devices use electromechanical motors and gear arrangements to provide
actuation.
This design promotes range-of-motion exercising of
the lower limbs, which improves circulation, reduces
muscle spasms and contractures, relieves joint stiffness, and promotes mental and physical health in patients with spinal cord injury. This device also offers
some upper body conditioning, since the upper body
provides the work to range the lower body.
The overall design is a synthesis of all major component designs (See Figure 4.10). The hand-controlling
sprocket is positioned at approximately the user’s
arm height. Foot pedals were used as handles in this
design, but will be replaced with handgrips before delivery to the user. Studies have shown that many
people with lower limb disabilities prefer an average
cadence of 15 rpms. The hand sprocket has a gear diameter ratio of 8:5 with respect to the leg sprocket.
This allows the user to pedal more slowly, at a rate of
about 9.4 rpms, to achieve the preferred cadence. It
was easy to drive the legs through a cycle, even
though the arms have a mechanical disadvantage via
this gear ratio.
The leg pedals have plastic footpads and Velcro
straps that hold the feet and provide proper foot positioning. The ankle supports are made from a stiff but
flexible plastic (similar to the plastic used in ski
boots) and are strapped around the user’s shins. The
ankle supports were found to be unnecessary for the
client and were removed. The seat is made of medium-stiff foam, attached to plywood backing and
covered with vinyl upholstery. The seat is bolted to
steel bars that are welded to a slider collar. The collar
slides along a 2” diameter tube with 4 possible pin
settings spaced 2” apart. A ½” steel pin placed
through the holes in the collar and mainframe tube allows 6” of travel at the 4 different pin settings.
The support frame is constructed of 1” square and 1”
outer diameter mild steel tubes (all 1/8” wall),
welded together and painted. Other final modifications to be made to this device include: adding a
chain tension sprocket, adding a chain guard, installing a square tube and slider collar, and adding further frame support behind the device to maintain stability during use.
Material costs for the Ex/ROM Bike were less than
$250.00, as standard bicycle parts were used for most
of the components.
Figure 4.10. Prototype for Exercise/Range-Of-Motion Bike.
CHAPTER 5
BINGHAMTON UNIVERSITY
Thomas J. Watson School of Engineering and Applied Science
Department of Mechanical Engineering
P.O Box 6000
Binghamton, NY 13902-6000
Principal Investigator:
Richard S. Culver (607) 777-2880
[email protected]
35
COLLAPSIBLE ACTIVITY FRAME
Designers: Jennifer Thurkins, Joel Andrews, Lucas Oracz, Owen Kim
Client Coordinator: Donna Boisvert, Vestal School District (VSD)
Supervising Professor: Professor Richard S. Culver
Binghamton University, SUNY
INTRODUCTION
A school district needed an activity frame, a device to
hold visual stimuli for children of varying developmental stages. The device was required to stand
above a child who is lying down or seated.
SUMMARY OF IMPACT
The activity frame allows various toys to hang above
or in front of a child. It enables a child to have toys
within the child’s constant reach.
The activity frame is constructed of 1 3/8” PVC furniture-grade plastic tubing. This material is both inexpensive and durable. Telescoping tubes with pushbutton locks make it fully adjustable in height. The
device is also foldable via pivoting joints on the end.
To fold flat, the top portion is removed, leaving the
two inner tubes free to pivot flat.
The final cost of the Activity Frame was approximately $15.
Figure 5.1. Collapsible Activity Frame.
Chapter 5: Binghamton University 37
ADJUSTABLE HEIGHT COMPUTER MONITOR
Designers: Aaron Ellis, Marin Jukic, Vinnie Rossi, Nathan Walker
Client Coordinator: Mary O’Dell, BOCES at Appalachian
INTRODUCTION
A desk was designed to incorporate a mechanism for
holding a computer monitor closer to the students’
eyes, thereby increasing the visibility of computer
graphics and text. The device accommodates a
wheelchair, which has a higher-than-average desktop.
SUMMARY OF IMPACT
Many children with visual impairments are unable to
use computers. A computer desk that brings the
monitor closer to the user is desirable because visibility of the monitor increases proportionally with decreasing distance.
user. The desk incorporates a commercial adjustable
arm upon which the computer monitor is mounted.
This allows users to bring the monitor closer to them.
The arm is adjustable to accommodate many users.
Attached to the desk is an internal surge-protecting
power supply. With the disconnection of one plug,
the computer, monitor, and desk can be moved, on
casters, as one piece. The final cost of the adjustable
computer desk was approximately $125.
The frame of the desk is made of pine. The table and
walls are made of ½” luan plywood. The desk is high
enough to accommodate a wheelchair, yet low
enough to allow easy viewing of the monitor. There is
storage space for the computer CPU to the left of the
Figure 5.2. A computer and computer monitor stand for the visually impaired children.
BALANCE BEAM
Designers: Alex Bell, Bryan Swanson, Erik Ng, Brian Pianoforte
INTRODUCTION
A lightweight, portable balance beam was constructed for use by the therapists in a school district.
It is 2”x4” in cross section and 8’ long. It folds into
four 2’ sections.
SUMMARY OF IMPACT
A portable balance beam is used in several schools. It
makes balance beam work more accessible to students
and obviates the need to buy a balance beam for each
school.
The device is constructed of a wooden frame made of
¾”x1 ½” stock and covered with ¼” luan mahogany
veneer. Eight feet long, it folds into four sections via
Figure 5.3. Portable Balance Beam.
four hinges mounted within the balance beam. When
extended, the beam is long enough for use, but when
folded, it fits easily under the arm of the user. A locking mechanism stabilizes the beam in both open and
closed positions.
A carrying strap made of conventional backpack
buckles and nylon allows for convenient carrying at
one’s side.
The final cost of the Balance Beam was approximately
$15.
BED RAIL ASSIST
Designers: Chris Jantzen, Steve Corletta, Vitaly Shusterov, Jeremy Rosen
Client Coordinator: Danny Cullen, STIC
INTRODUCTION
A device was designed to assist people who have
trouble transferring themselves into and out of bed.
SUMMARY OF IMPACT
Bed rails are an easy way to help a person get into
and out of bed. However, most beds do not have bed
rails. A device that mounts to any bed is useful for
people who have trouble transferring themselves into
and out of bed.
The device is constructed primarily of 1 3/8” PVC
pipe. The vertical post has a piece of steel conduit
mounted inside for stiffening purposes. The base of
the device is a circular piece of ¾” plywood, with a
mounting flange for the PVC pipe.
The device is further supported by a 3/16” PVC panel
that clamps to the vertical post and slides under the
bed mattress. The panel is vertically adjustable to fit
the height of the bed. The lifting handle is rotationally
adjustable so that the bed rail assist can be used from
virtually any direction.
PVC Slip Tee’s that fit the vertical PVC tube are used
to allow for adjustment. The top Slip Tee has slots
machined in its bottom edge that fit over the head of a
cap screw. This allows the lifting handle to be set at
several different positions.
The final cost of the Bed Rail Assist was approximately $20.
Figure 5.4. Bed Rail Assist
CART WITH BASKET
Designers: Michael Spector, Chris Lent, Jason Lewen, Xu An Zeng
Client Coordinator: Terry Terrell, STIC
INTRODUCTION
A cart with casters and a removable wire-frame basket was built for a woman who has limited mobility
and difficulty carrying hot items from the stove to
other locations in the kitchen.
SUMMARY OF IMPACT
Conventional walkers do not incorporate the use of a
basket to carry items. This cart, which is equipped
with both a basket and casters, allows the client to
work in the kitchen without relying on others.
The cart is constructed of 1 3/8” PVC furniture-grade
tubing. The PVC offers an attractive finish, while
yielding the necessary strength and ease of assembly
required in any project.
The padding on the rear support tube is vinyl over
foam, mounted to the PVC frame.
The rear of the cart is free of obstructions. It incorporates a basket for carrying kitchen items and food
across the room. The basket is held in a slotted frame
so that it can be removed, but will not slide out of position when being used. The 4“ casters on which the
cart rolls are mounted away from the user’s feet. Two
of the casters are lockable.
The final cost of the Cart with basket was approximately $75.
Figure 5.5. Cart with Basket.
CHAIR ADJUSTMENT
Designers: James Wei, Shan Su, Lindsey Krough
Client Coordinator: Colleen Griffith, Johnson City School District
INTRODUCTION
Many school chairs are not adjustable to fit small
children, especially those with physical disabilities.
Standard back supports and footrests often leave
children sitting too far from their workspace to provide reasonable access. An adjustable foam back
support and adjustable wooden footrest were constructed to fit a standard school chair.
SUMMARY OF IMPACT
A chair with adjustable back support and footrest
will help small children.
The device is made of foam and vinyl construction.
The vinyl covers a series of removable thin foam
sheets, allowing the vinyl pad to increase and decrease in thickness, thus adjusting the depth of the
back support/rest of the chair. A 2” nylon strap with
buckle adjustment, sewn into the seams of the vinyl
cover, attaches the pad to the back of a regular school
chair.
The footrest is constructed primarily of wood with
metal screw fasteners. The structure is attached to the
existing legs of the chair by way of a clamping
mechanism, which is adjusted using two hand fasteners.
The final cost of the Chair Adjustment was approximately $15.
Figure 5.6. School Chair to Accommodate a Small
Child.
DOUBLE PEDAL BOARD
Designers: Nnamdi Nwanze, Brian Lamond, Charles Kim, Craig Marcinkowski
Client Coordinator: Inalou Davey, Rehabilitation Services Inc., (RSI)
INTRODUCTION
The Double Pedal Board was constructed for clients
who lack balance or have weakness on one side of the
body. Patients may use it to gain strength on a weak
side, and to gain balance.
SUMMARY OF IMPACT
Many people lack strength on one side of their body
or have trouble balancing while standing or walking.
The Double Pedal Board allows a person who has
unilateral weakness to gain strength. It also allows
users with a lack of balance to gain balance by mimicking a motion similar to walking or climbing stairs.
The main structure of the Double Pedal Board is
wooden. The handles are wooden, and are bolted to
the main foot pedals, via screws and metal rightangle brackets. These brackets allow the user to put
most of his/her weight on the handles without fear of
falling.
The device consists of six wheels mounted opposite
two pedal boards such that two of the wheels are located between the length of the boards and the other
four are located outside of the pedal boards.
When the user presses down on one foot, the device
begins to move forward or backward by way of four
offset mounting pivots to which the pedal boards are
attached.
Figure 5.7. Double Pedal Board.
The handles of the device are adjustable to accommodate the height of many individuals.
The final cost of the Double Pedal Board was approximately $50.
FOLDING CHAIR
Designers: Karima Legette, James McFarlane, Martine Passe, Brian Muszynski
Client Coordinator: Judy Zeamer, High Risk Birth Clinic
INTRODUCTION
A three-year old girl needed a replacement for a folding chair she had outgrown. The chair accommodates a potty seat, and has a folding mechanism for
storage in an automobile.
SUMMARY OF IMPACT
It is difficult to find ergonomic chairs for children
with physical disabilities, especially chairs that are
comfortable but compact and foldable. This chair can
be taken in the car and used for a portable potty as
well as sitting chair.
The main structure is wooden, and has six components: the left arm, right arm, left folding support,
right folding support, and front and rear main supports. The six components are hinged so that the
chair can fold in one piece. The chair locks into position through the use of two easily adjustable steel
straps.
The seat of the chair is removable, and any comparably sized seat may be used, including the potty seat
especially modified for this chair ( as shown in figure
5.8).
A 2“ thick footstool was supplied with the chair to allow for use by smaller children.
The final cost of the folding chair was approximately
$25.
Figure 5.8. A Foldable Adjustable Chair
HEAD SUPPORT FOR CHAIR
Designers: Raymond Wong, Jake Liu, Brad Bungo, Tom McCabe
Client Coordinators: Colleen Griffith, Johnson City School District
INTRODUCTION
Many children with disabilities have difficulty supporting their heads properly. Lack of proper head
support can lead to respiratory problems and neck
and back difficulties as well as a number of other
problems. A school district needed a head support
that could be mounted on their existing Trip-Trac
chairs. The head support needed to attach to the back
of the chairs and be adjustable in height and forward/backward mobility.
SUMMARY OF IMPACT
The add-on head support increases the usefulness of
a Trip-Trac chair and makes it accessible to many
more people who could otherwise not use this chair.
The head support was constructed from a musicstand frame. The frame, while lightweight, is adjustable in height, enabling the head support to be used
by different people.
The actual headrest connects to the aluminum frame
via an adjustable aluminum rod. The adjustment allows the user to sit with his/her head resting at multiple angles.
The device clamps to the existing Trip-Trac chair via
three small aluminum clamps designed such that no
modification has to be made to the original chair.
The headrest is constructed of foam and vinyl, with a
thin sheet of aluminum within for basic structural
support.
The final cost of the headrest was approximately $30.
Figure 5.9. Head Rest Attachment for the TripTrac Chair.
THE HEAD SWITCH
Designers: Tony Huang, Izhar Ahmad, Alok Bhalla, Jason Yuen
Client Coordinator: Beth Peck, ARC Day Treatment Program
INTRODUCTION
A head switch was designed to enable a patient to
turn music on and off at will without the help of another person.
SUMMARY OF IMPACT
The head switch allows the client to control her music
independently.
The switch is a plastic hinge with a micro switch
screwed on to one of the inner sides. As the hinge is
pressed, it in turn presses on to the micro switch, ac-
Figure 5.10. Head Switch.
tivating the circuit. The plastic base is firmly
screwed against a half-inch plywood board. The bottom part of the wooden board is fitted with Velcro. A
facing Velcro strip is attached to a beanbag. Finally,
four parallel slits are drilled and filed into the curved
plastic base. Two nylon straps are then inserted
through these slits, and two pairs of complementary
buckles are attached to either end of the straps. The
straps secure the device to the headrest.
The final cost of the Head Switch was approximately
$15.
ADJUSTABLE PENCIL GRIPPER
Designers: Mike McCarthy, Tamir Ratzon, David Lomonaco, Hsing-I Lin
Client Coordinator: Bonnie Cole, Handicapped Children’s Association
INTRODUCTION
Some young children with limitations in the use of
their hands have difficulty grasping small objects
such as pens and markers. A hand-held gripper for
writing instruments was constructed to address this
problem. The handle of the pencil gripper is perpendicular to the writing instrument, which allows the
user to lay his or her hand on the table while writing.
SUMMARY OF IMPACT
holder are replaced with a heavy rubber band that
keeps the jaws closed. A writing instrument is inserted between the two fingers of the beaker holder.
The handle is coated with rubber tape for a stronger
grip. The device can accommodate writing instruments with an outside diameter from #2 pencil size to
¾ inch.
The final cost of the adjustable pencil gripper is approximately $10.
A pencil gripper enables small children and those
with physical disabilities to work more accurately
with small writing instruments.
The gripping portion of the pencil gripper is made
from a modified beaker holder. The holder is in stalled inside a one-inch diameter PVC tube. The
thumbscrews used to compress the jaws on the beaker
Figure 5.11. Adjustable Pencil Gripper.
PUPPET THEATRE
Designers: Michael Begic, Erik Springer, Pamela Ayoub, Brian Vallimont
Client Coordinator: Penny Baldwin, BOCES at Appalachian
INTRODUCTION
A medium sized puppet theatre was constructed for
children with autism. The theatre is portable, yet
sturdy, incorporates internal lighting, and has a retractable curtain.
SUMMARY OF IMPACT
The puppet theater provides a unique way for children with autism to express themselves. In addition,
this theatre provides wholesome entertainment for
many children.
The main structure is made of pine and ½” birch
plywood. Metal cornering brackets provide internal
Figure 5.12. Puppet Theatre.
structural stability. The result was a lightweight,
sturdy puppet theatre.
The theater has three internal lights, red, green, and
blue. Each light, operated with its own switch, allows the users to modify the mood and tone of the
theatre.
An adjustable curtain rod with pull cords has been
modified to make it possible for the user to open and
close the curtains from the rear of the theatre.
The final cost of the puppet theatre was approximately $100.
SCOOTER BOARD
Designers: Steven Violante, Derrick Farfan, Rebecca Knowlton, Nova Greenberg
Client Coordinators: Donna Boisvert, Vestal School District (VSD)
INTRODUCTION
A was designed to enhance students’ mobility. A
removable frame with straps allows a child who cannot support him/herself to ride. It is adjustable to accommodate children of different sizes.
SUMMARY OF IMPACT
Scooter boards are small platforms with wheels
mounted on the bottom. Individuals can sit or lie
down on the board and push themselves along in any
direction using their hands.
This particular scooter board permits the user to operate in either a sitting or lying position, a feature not
incorporated in existing scooter boards.
The device is constructed of PVC, foam, and cloth, as
well as ¾” pine board. The pine board serves as the
structural mainstay of the device, with the wheels
mounted onto the board. The board is divided into
Figure 5.13. Scooter Board.
two sections combined together using hand tightened
wing nuts. The split bottom of the device allows the
user to adjust its length.
The back of the device is constructed of PVC and
cloth. The PVC acts as the main support, while the
cloth, which is stretched taut across the PVC support
frame, acts as a backrest.
Also included in the design are multiple nylon straps
to secure the user to the device, as well as multiple
foam back supports for cases when the user rides in a
prone position.
The final cost of the project was approximately $35.
SIT-AND-SPIN TOY FOR LARGER CHILDREN
AND ADULTS
Designers: Kristen Beal, Eric Stellrecht, Kevin Stein, Stephanie Deckter
INTRODUCTION
A Sit-and-Spin toy was designed for use by larger
children and adults. Similar toys on the market are
too small and are made of plastic materials that fail
under loads of larger children and adults.
SUMMARY OF IMPACT
A Sit-and-Spin is a fun toy that enhances hand-eye
coordination and upper body strength.
The device is constructed of luan mahogany plywood, PVC tube, an extra large commercial thrust
bearing, and plastic casters with metal frames.
tial to the circular base. While the casters relieve some
of the load on the base of the Sit-and-Spin, the use of a
thrust bearing was deemed necessary for smooth operation. Thus in the center of the main platform a
thrust bearing is mounted to disperse most of the load
in the center of the toy while providing a smooth rolling motion. The center shaft of the device is constructed of PVC tube. A simple bolt mechanism and
holes along the center shaft allow for easy adjustment
of handgrip height.
The final cost of the Sit-and-Spin is approximately
$90.
The main platform of the device is constructed using
the plywood. Underneath the main platform are
mounted four casters, with their line of travel tangen-
Figure 5.14. Sit-and-Spin Toy for Larger Children and Adults.
STAND-PIVOT SYSTEM
Designers: Vincent Lee, Matt Yavorsky, Christopher Yatrakis, Peter Joo
Client Coordinator: Valdo Rogers, Broome Development Center
INTRODUCTION
A stand-pivot system was designed to easily and
safely transfer clients to and from wheelchairs and
beds.. The Broome Development Center works with
many people who have difficulty transferring from a
wheelchair to a bed. The difficulty increases when
the individual has limited control of his/her legs.
The individual’s feet often bind on the floor during
the rotation that takes place in the transfer.
SUMMARY OF IMPACT
The device, a flat freely-spinning disk mounted close
to the floor, enables the easy rotation of one’s body to
facilitate the safe transfer of individuals to and from
wheelchairs and beds.
Figure 5.15. Stand-Pivot System.
The device is constructed of 3/16” PVC plastic sheeting (Figure 5.15). Two pieces of this strong yet flexible
material are mounted together using standard commercially available thrust bearings.
The bottom and top surfaces of the device are coated
with non-slip tape to further enhance the safety of the
device.
The final cost of the stand-pivot system to transfer clients to and from wheelchairs and beds was approximately $17.
FLOTATION BELT
Designers: Todd Young, Miheer Fyzee, Catherine Ma, Erica McKenzie
Client Coordinator: Colleen Griffith, Johnson City School District
INTRODUCTION
A buoyancy system was designed to allow a client
with cerebral palsy to be held at the correct orientation and with the minimum buoyancy needed to
maintain proper swimming form.
SUMMARY OF IMPACT
The flotation belt replaces an improvised swimming
belt that was unsightly and difficult to use. This belt
is attractive and easy to adjust. It has contributed to
the client’s progress in a special swimming program.
The device, designed for children with cerebral palsy,
is mainly composed of nylon and Styrofoam. Two
straps with adjustable buckles allow the device to be
Figure 5.16. Flotation Belt.
used with a wide variety of children.
The device is also adjustable in other ways. Multipart Styrofoam pads that slip into the nylon allow
any number of Styrofoam pads to be used to adjust
the flotation of the device for children of various
weights. Also, the straps can be adjusted to hold the
device at different positions on the user’s torso.
The final cost of the swimming aid was approximately $15.
TABLE FOR BENNETT BENCH
Designers: Will Wojtkielewicz, Robert Polak, James Gale, Patrick O’Meara
Client Coordinator: Inalou Davey, Rehabilitation Services Inc., (RSI)
INTRODUCTION
The Bennett Bench is a device for exercising bimanual manipulation skills. A lightweight, rigid, adjustable table was built so that more people with disabilities can use the Bennett Bench equipment.
SUMMARY OF IMPACT
The adjustable Bennett Bench table provides much
needed access to the Bennett Bench for people who
currently cannot use it due to height restrictions. The
adjustable stand allows different users to use the Bennett Bench.
The frame of the Bennett Bench table is made of 1
3/8” furniture-grade PVC tubing. Incorporating telescoping tubes, the frame is adjustable to accommodate varying heights of sitting and standing users.
The bottom of the table uses PVC end caps to ensure
stable footing. The table surface is ¾” luan mahogany plywood.
The final cost of the Table for Bennett Bench was approximately $40.
Figure 5.17. Adjustable Table for the Bennett Bench
ADJUSTABLE MULTI-USER COMPUTER
STATION
Designers: Ben Huang, Mohammed Kashef, Paul Marinello, Robert Lockwood
Client Coordinator: Beth Peck, ARC,
Supervising Professor: Richard S. Culver
INTRODUCTION
The differing heights of wheelchairs make it difficult
to tailor workstations for multiple users. A sheltered
workshop needed a multi-user station to accommodate many individuals in wheelchairs of varying
heights.
SUMMARY OF IMPACT
The device enables people with different working
heights, due to varying wheelchair sizes, to work on
the same workstation
boxes for storage, located on the top of the unit, as
well as an adjustable wooden tabletop. The tabletop
was mounted on commercial, adjustable steel shelving brackets similar to those used for bookshelves.
The structural frame of the device was designed to be
easily collapsible if the need for low-space storage
arises. It is made out of clear pine lumber. The feet are
foldable, and the shelves are easily removed as well.
The final cost of the device was approximately $80.
A four-person desk-type unit allows each person to
work at a different height. Each desk incorporates
Figure 5.18. Adjustable Multi-User Computer Station.
WHEELCHAIR STORAGE RACK
Designers: Yassir Hussain, Jared Miller, Jae H. Park, Tim Schlauraff
Client Coordinators: Valdo Rogers, Broome Development Center
INTRODUCTION
A storage rack was built to support eight wheelchairs.
It allows for easy access to the wheelchairs and
eliminates damage due to haphazard stacking.
SUMMARY OF IMPACT
Wheelchairs are costly and difficult to repair. Proper
storage of these essential devices is necessary to preserve and maintain them. This rack represents a major improvement to the management of wheelchairs at
a developmental center.
The device, designed to meet strict fire code requirements, is composed entirely of steel fence posting.
Strong and lightweight, this material is both functional and aesthetically pleasing.
The device consists of basic box-frame construction,
with joints composed of standard fencing elbows.
The rack has three horizontal rails. Two rails hold
the large rear wheel, while the third, which is slightly
higher than the other two, supports the wheelchair
frame behind the small front wheel.
The device, while relatively compact, can store up to
eight wheelchairs: four on top, and four below.
The final cost of the wheelchair storage rack was
$283.
Figure 5.19. Wheelchair Storage Rack.
FOOT-PROPELLED WHEELCHAIR
Designers: Philip Suarez, Vincent Look, Joel Almonte, Robert Bracero
Client Coordinator: Terry Terrell, STIC
INTRODUCTION
The foot-propelled wheelchair was built for an elderly
woman with cerebral palsy who prefers to propel herself with her feet. Her existing wheelchair was in
disrepair and did not allow easy foot movement.
SUMMARY OF IMPACT
A wheelchair with free space for feet allows the user
to propel herself without using her hands. This new
wheel chair improves her mobility and is an attractive
alternative to the one she was using.
The wheelchair frame is constructed of 1 3/8” furniture-grade PVC tubing. The PVC offers an attractive
finish, while incorporating the necessary strength
and ease of assembly required in any project.
The padding of the chair is vinyl over foam, which is
supported on the PVC frame with 3/8” plywood.
The front of the chair is free of obstructions, unlike
conventional wheelchairs, and the casters on which
the chair rolls are mounted away from the user’s feet.
The two rear casters are lockable and are frozen so
that they only track forward.
The final cost of the Wheelchair is approximately $60.
Figure 5.20. Foot-Propelled Wheelchair.
ADJUSTABLE WALKER
Designers: Seamus Gorman, William Schumacher, Jessica Terry
Client Coordinator: Colleen Griffith, JCSD
INTRODUCTION
An adjustable walker was designed for children with
developmental delay.
SUMMARY OF IMPACT
A walker device was needed to help children maintain their balance while walking. The multiple-use
stabilizing device can be used by children of varying
sizes. Varying amounts of tension can be placed on
the wheels to match the child’s ability. The resistance
can be lessened as the child gains strength and walking skills. This allows for a gradual progression of
becoming less dependent on the walker. Once the
child masters the coordination that is required to
walk with no tension, the swivel lock can be disabled
to allow the child to learn how to change directions.
The walking process is simplified into manageable
and yet challenging steps that can be isolated and
then mastered.
The children’s walker was designed to be used by
more than one child. Therefore, many of the features
of the walker are adjustable. The main requirements
were that it: 1) support the weight of a child up to 50
pounds, but not provide so much support that the
child would become dependent upon the device; 2) be
lightweight enough so that it is portable and maneuverable; 3) be durable and easy to maintain; 4) allow
enough room for the child to walk behind it with a
12” wide clearance for feet; 5) have a handle of about
¾” diameter with a height adjustment range of 1½-2’;
6 work on both hardwood floors and carpet; 7) have
adjustable wheels resistance; 8) have a steering and
rigid mode as well as wheels which only roll forward;
9) permit any adjustments to be made in under five
minutes; and 10) be safe.
The walker has a 20”x20” U-shaped base with two
20” posts rising from the middle of the two long sections of the U. These posts are secured to the base
and the handle is mounted to the two posts. Four
pivoting casters are mounted to the corners of the U.
The entire frame is constructed from 1¼” furniture
grade PVC piping. Slip Tee and internal elbow fittings are used to join the members of the frame. Holes
in the posts at 1” spacing allow vertical adjustment of
the handle. The handle, constructed from ¾” PVC
tubing, is screwed into Slip Tee joints, which fit over
the posts.
The two rear 2” casters do not pivot. A screw can be
forced against the surface of the caster to provide adjustable resistance and can be used as a stop when
screwed all the way down.
The two front swivel 2” casters feature a swivel lock,
which allows the wheels to have a rigid and a steering mode. In order to create this device, a ½” thick
aluminum block was cut in a C-shape, which fits
snugly around the wheels. A hinge connects the
caster mounting plate to the aluminum block. This allows the block to rotate down onto the wheel and lock
it in a fixed position, or to rotate up and allow the
wheel to swivel freely. An elastic band holds the
block in place when the caster is allowed to pivot.
The total weight of the device is 8.7 pounds.
The cost is $67.00. A similar device is available on
the market, but not with all of the features that this
walker offers for such a low price.
Figure 5.21. Adjustable Walker.
AUTOMATIC ROCKER FOR AN EASY CHAIR
Designers: Jared Waugh, Ricky Lu, Ariel Reiter
Client Coordinator: Valdo Rogers, Broome Development Center
Binghamton University
INTRODUCTION
An automatic rocker was made for a twenty-year-old
man with autism. It fits under the lower rear edge of
an overstuffed rocking chair. It consists of a rotating
arm on a small gear motor, mounted in a frame that
sits on the floor. When operating, the rotating arm
pushes up on the seat through a rolling bearing.
SUMMARY OF IMPACT
Previously, the client’s caregiver found that when he
rocked the chair with his foot, it calmed the client.
The Automatic Rocker relieves the caregiver of having
to rock the chair.
Measurements of the range of motion of the chair and
the natural frequency of the rocker indicated that the
vertical travel is 3” at a frequency of approximately 39
rpm. The maximum vertical force required to obtain
this displacement is 20 pounds. Using this information, a gear motor, which runs at 35 rpm and has a
maximum torque rating of 30 inch- pounds, was se-
lected. The motor is attached to a 5/8” plywood
frame, which extends under the chair. A 1/2" diameter shaft extension is mounted on the motor. The 2"
aluminum crank arm supports another 1/2" shaft at a
distance of 1 1/2 " to provide the needed vertical motion. A 3/4" diameter PVC sleeve which slips on the
crank provides a moving bearing to reduce friction between the bottom of the chair and the rotating arm.
Because of the geometry of the system, the maximum
vertical force of 20 pounds is applied when the crank
moment arm is of zero length. The maximum applied
torque occurs at 45o above horizontal. It is calculated
to be about 10 inch- pounds, which is well within the
capacity of the motor, particularly since the motor
only applies this torque for a small portion of each rotation.
The motor assembly has a wooden cover, with metal
screen ends to allow for ventilation.
The total cost of the automatic rocker is $75.
Figure 5.22. Automatic Rocker for an Easy Chair.
CLIMBING WALL FOR YOUNG CHILDREN
Designers: Brian Ide – Junior, Matthew DuBord, Jason Borgen, Daniel Roesser, Allan Assuncion
Client Coordinator: Laura Cline, Handicapped Children’s Association
INTRODUCTION
An adjustable climbing wall was constructed for use
by children. Eight feet high and 6 feet wide, it is attached to a tubular steel frame, which allows it to be
set at different angles. A variety of handles and
handholds are provided on the face of the wall to assist children in climbing on it. A horizontal bar at the
top of the wall provides an anchor for a climbing
rope, which is attached to a climbing harness on the
child. The frame is designed to allow one or two
therapists to be on the wall with the child to assist in
climbing. The wall surface is covered with linoleum
to provide a smooth surface that will hold plasticbased stick-on cartoon characters, enhancing motivation for climbing.
Figure 5.24. – Upper Frame Support
SUMMARY OF IMPACT
Climbing walls provide an ideal activity for children
with limited physical ability to stimulate hand/eye
coordination and to build upper body strength. The
climbing wall takes up much less space than a jungle
gym and provides a single controlled surface upon
which a child can exercise. Its flat surface provides a
convenient means for the therapist to provide active
support while the child is climbing.
Figure.5.23. Climbing Wall at 60o Angle.
The climbing wall surface is made of two 4’x 6’, ¾”
plywood panels. Holes 5/8” diameter, are drilled in
the panels in a regular pattern to provide anchor
points for the handholds. Footholds are also cut into
the surface of the wall. The wall is covered with a
tan, pebble-patterned linoleum that resembles a rock
wall.
The panels are mounted on a moving frame made
from 1”. square tubular steel. Three-inch casters are
mounted on the bottom of the frame. A ½” steel rod
runs across the top of the frame and extends past the
end of the frame an additional inch to provide the
upper sliding anchor. Plastic tubing on the rod provides the sliding surface. The matching steel tubular
frame attached to the wall has a steel l-shaped angle
welded to the side to provide a channel for the plastic
covered anchors. Eye-bolts attached to the lower extremities of the fixed frame on the wall and the moving frame are used to anchor a heavy-duty steel chain
which allows the wall to be supported at different
angles from the wall.
Two types of handgrips are used. Children’s’ tricycle
handgrips are slid onto 5/8” bolts protruding
through the wall. Wooden handgrips made from
lumber and covered with fiberglass are also used.
The fiberglass resin was dipped in sand when wet to
make a nonslip surface. A 5/8” bolt attaches the
handgrips to the wall. These can be moved around
the wall to create the desired climbing pattern.
The cost of materials for the climbing wall is $275.
Figure 5.25 – Caster on Lower Leg of Climbing Wall.
COLLAPSIBLE CANE FOR THE BLIND
Designers: James Keane, John Nenadic, Dave Allen
Client Coordinator: Dave Scudder, Intellidapt
Supervising Professor
Professor Richard S. Culver
INTRODUCTION
A new design was developed for a collapsible cane
for individuals with blindness. Joints using a metal
hinge with a bungee cord running through the center
replace the traditional slip joint.
SUMMARY OF IMPACT
Commercially available folding canes for use by individuals with blindness are made of aluminum tubing.
One end of each tube is reduced in cross section so
that it fits inside the next tube. An elastic bungee cord
runs through the entire cane to pull the individual
tubes together. In use, the sharp edge of the tube can
eventually cut through the bungee cord. Also, the
tube joint often becomes loose from repeated assembly
and bending. The joints are not strong. If loaded laterally, the joints can bend or open up. The cane built
in this project uses a more robust joint, which works
in a manner similar to the traditional cane. In a field
trial, someone accidentally stepped on the cane, but it
did not break, confirming the strength of the joint.
This cane design will permit longer use and more
user confidence than current commercial models.
One side of the yoke and tongue hinge can slide out
while the other is fixed. The elastic bungee cord that
holds the joint together when assembled passes
through the hinge pieces. To operate, the user pulls
the two tubes apart, stretching the bungee cord.
When the hinge joint is clear of the nesting tube, it can
be folded. The joint parts are made of aluminum, as is
Figure 5.26 – Collapsible Cane in Use.
the shank of the cane. The cane tubular wall was reduced in thickness between joints in order to reduce
the weight of the cane. This cane weighs approximately the same as commercial canes.
The cost of materials was approximately $25.
Figure 5.27 – Joint on Collapsible Cane.
ELECTRONIC LOCK
Designers: Abraham Howell, Dairusz Filak, Jose Tova
Client Coordinator: Colleen Griffith, JCSD
INTRODUCTION
An electronically operated lock system was designed
and built to attach to a regular locker door.
SUMMARY OF IMPACT
The client is a 13-year-old female middle school student with cerebral palsy. She could not open her
school locker due to her limited manual dexterity
with the combination lock. The electronically activated rotary lock system on allows her to open the
locker on her own from her wheelchair.
An actual locker door was removed from its frame to
facilitate installation. The handle was removed and
new holes were drilled to allow for the mounting of a
tubular solenoid actuator. A receiver and transmitter
from Power Door products provide the electronic control for the lock. When the small, handheld transmitter sends a signal to the receiver, a relay in the receiver is closed. The relay sends power to the 12-volt
door actuator, which opens the rotary latch.
The receiver requires 24 volts and the solenoid actuator, 12 volts. Transformers to provide these voltages
are mounted in the ceiling and attached to a 110-volt
duplex outlet.
All sharp edges are removed from the door and lock
fittings to prevent injury. The handheld transmitter is
mounted with Velcro to the client’s wheelchair. The
transmitter has a large button.
Figure 5.28. Electronic Lock.
The final cost of the Key Lock Mechanism is approximately $175.
A RACE CAR FOR CHILDREN
Designers: Kevin Kressner, Lauri Tacadema, Michael Mainville
Client Coordinator: Mary O'Dell, BOCES Appalachin School
INTRODUCTION
A commercial four-wheeled pedal car was modified
for use by elementary school students. The car has an
adjustable seat and a PVC body that folds back to
permit easy access.
SUMMARY OF IMPACT
A pedal car was designed for students to use in
physical therapy and recreation programs. The
school was unable to afford an equivalent commercially available vehicle. The students vary in ability,
size and weight (from 4'6" to 6' and from 100 to 250
pounds). The car allows several students to ride on
the playground.
For safety reasons, a commercial frame was used. It
was purchased from Quadracycle, in Hamilton IN.
Figure 5.29. Race Car.
Made of rectangular steel tubing, it is designed for a
single rider and has a regular steering wheel and
hand brake. It has 16" balloon tires. Local fabrication
involved the design and construction of a PVC body,
attached to the frame with hinges and latches. PVC
sheet, 1/8" thick, was hand formed using a heat gun.
The shape of the body is carefully designed to permit
use of straight bends. The hood is mounted with
hinges so that it can be raised to assist the driver in
entering the car.
Upon completing the construction, the body was
spray-painted racing green.
Cost of the pedal car is $495. The PVC plastic sheet,
fittings and paint cost $70. The total cost of materials
is $565.
POOL LIFT FOR SMALL CHILD
Designers: Matthew Rubin, Christopher Conklin, David Wong
Client Coordinator: Judy Zeamer, High Risks Birth Clinic
INTRODUCTION
A fiberglass seat, which can be lowered by hand into
a swimming pool, was made for a four-year-old girl
with cerebral palsy. The seat is attached, by pivoting
arms, to a PVC tubular frame that is clamped to the
wooden deck surrounding the swimming pool. In
use, the girl is strapped into the seat at the poolside.
The seat is then lifted by a bar (molded into the top of
the chair) and rotated until it is over the water. The
seat is then lowered into the water. A clamp on the
vertical guidepost controls the depth of submersion.
SUMMARY OF IMPACT
The client’s use of the pool had been limited because
she cannot support herself in an upright position.
The lifting mechanism makes it possible for her parents to easily lower her into the water. The lift provides a safe means by which the client can enjoy the
water and participate in water play with her friends.
The pool lift is made from PVC plastic tubing and fiberglass. The seat is formed from fiberglass, using a
wooden frame, molded around two PVC tubes, which
connect the seat to the supporting frame. On the end
of the two horizontal PVC tubes, Slip Tees are held
with bolts. These Tees allow the seat to move vertically and rotate around the main vertical post. The
main post consists of a PVC tube with an internal
steel electrical conduit and spacer for stiffening. On
the bottom of the conduit is a 16-pound steel disk that
anchors the post to the pool bottom. The disk and
conduit are coated with rubber to prevent rusting.
The top of the vertical post is attached to a PVC frame
that is bolted via a PVC flange to the wooden pool
deck. The supporting frame is attached to the vertical
post using slip joints with spring buttons so that the
post can be removed for storage.
The frame and seat cost approximately $90.
Figure 5.30. Pool Lift.
PORTABLE SWIMMING POOL STAIRS
Designers: Jason Mooney, James, Bush, Jonathan Curtin
Client Coordinator: Sheila Zuba, Johnson City YMCA
INTRODUCTION
A portable stairway was designed and built to provide access to a swimming pool for people with limited mobility.
SUMMARY OF IMPACT
Many of the participants an active water therapy program for senior citizens are heavy and have difficulty
getting into and out of the pool. The portable steps
previously used were very steep. Rising above the
pool level, they were especially difficult to negotiate.
An expensive commercial pool stairway system had
been purchased but did not work. The stairway built
in this project is so popular that people were upset
when it was removed for refinement.
The pool stairway is constructed from 2" x 6" fiberglass channel. The channel is used for the side runners and double width channels form the steps. The
actual rise for each step is 6”. By hooking the stairway to the rolled stainless steel edge on the pool with
a matching stainless steel lip, it was possible to minimize the number of steps. The stairway has to fit
between the end of the pool and the permanent ladder, which is about 8‘ from the end of the pool. The
steps are attached to the runners with flanges made
from channel material. A 3/4" diameter PVC tube is
mounted to the bottom of each runner to provide a
skid to assist in lowering the stairway into the pool.
The stairway is painted bright yellow with epoxy
paint.
Figure 5.31. The Pool Stairway in the Water.
When the stairway was completed, it was found to be
stiff enough in bending but had low torsional rigidity.
Plexiglas panels were thus mounted between adjacent steps as stiffeners. This significantly improved
the rigidity.
Figure 5.32. Pool Stairs on Deck.
The rails are made of reinforced furniture-grade PVC
tubing. Steel electrical conduit with spacers is placed
in each vertical support. Threaded aluminum joints
were matched to the conduit to provide longitudinal
stiffening in the lower horizontal rail. The rails are
attached to the side of the stairway using PVC Tees.
The stainless steel lip, which holds the stairway to
the edge of the pool, was made commercially from 20gauge sheet. When the steps were installed, it was
found that the lip slowly deformed under load and
unwrapped from the pool edge. The lip was rerolled
and a PVC frame was constructed to sit under the
uppermost step on the stairway. When the lip slips
approximately 0.05" under load, the frame takes the
load. This insures that the lip is tightly attached to
the edge so that it will not slide sideways.
Total cost of the pool stairs is $975.
Figure 5.33. Attachment of the Handrail to the Stairway Frame.
PRESSURE VEST
Designers: Ellen Dulberg, Fredric Johannesen, Steve Rossi
Client Coordinator: Christine Breslin, HCA
INTRODUCTION
A Pressure Vest was designed for young children
with autism. The device is mechanical. The child
places the vest around his/her torso and applies
pressure by rotating a hook, which then pulls the
front of the vest together. Studies have shown that
this type of pressure technique may be therapeutic in
some cases. The interior of the vest is made of foam
and steel ribs, surrounded by canvas on the exterior.
The ribs provide rigidity. The child controls the device, but is under adult supervision at all times.
SUMMARY OF IMPACT
Deep pressure therapy is sometimes used with the intent to satisfy the need of individuals with autism for
tactile stimulation. Pressure is slowly applied over
the individual’s body for a calming effect. Experts
consulted were clear that this method of treatment is
not a universal solution to the needs of individuals
with autism. Although the vest provided the desired
pressure on a small child, use was discontinued because of the risk of causing internal injury. Without
appropriate feedback there is no effective way to protect the child.
The dimensions of the vest were based on measurements of average three- to five-year-olds in a local
preschool (24” (± 3”) around the waist, and 10½” (±
1”) from armpit to hip). The vest is 30” in length
when laid out flat, and 10” high.
The tightening/pressure applying mechanism consists of a hook and a hitch (Figure 5.33), made from
aluminum and mounted directly on the ribs of the
vest. The handle on the hook has a swivel knob for
easy operation. There is an overlap on the back of the
vest in order to make the vest adjustable to fit children
of differing sizes.
Figure 5.34. Pressure Vest showing rear adjustment straps.
There are belt loops on the back of the vest so the
child can be immobilized by using a winch strap.
The hook’s radius decreases from 3” to ½”. The pressure is applied to the torso when the child rotates the
handle. The decreasing radius will pull the two sides
of the front of the vest together. As seen in Figure
5.34, part of the hook has a constant radius. This assists the supervisor in inserting the hook into the
hitch.
The supervisor puts the vest on the child and inserts
the part of the hook with a constant radius onto the
hitch. Then the supervisor tightens the buckles in the
back of vest to fit the child, and immobilizes the child
with the winch strap. Next, the child rotates the handle to increase or decrease the pressure. To get out of
the device quickly, the child may simply rotate the
handle all the way back until the hook comes out of
the hitch.
The total cost of the vest was approximately $165.00.
The majority of the cost was for tailoring expense.
Figure 5.35. Pressure Vest with Adjustable Mechanical Latch.
BLOW-STRAW UNIVERSAL REMOTE CONTROL
Designers: Daron King, David Peek, Roger Richardson
Client Coordinator: Inalou Davey
INTRODUCTION
A universal remote control device was designed to
accommodate the needs of a client with quadriplegia
who is visually impaired. The remote consists of two
modular components, the frame and the remote box.
The frame is H-shaped, consisting of two bases with
vertical posts, and a cross-member that holds the remote box in place. The cross-member is composed of
two parallel bars, which are offset horizontally, and
slip joints, which connect the cross-member to the vertical posts. The cross-member is adjustable in height
and also removable for storage. The remote box consists of four input straws and an output display. Desired results are achieved by blowing or “puffing”
through the insert straws. The output display consists of two series of large, colored LED lights, which
illuminate in conjunction with the device’s functions.
The colored lights are used to accommodate the vision impairment, since text labels are unreadable.
The remote allows the client to operate a television,
cable, radio, and CD player through infrared light.
Four additional devices can be added.
Figure 5.36. Universal Remote Control Stand in
Use by Client.
SUMMARY OF IMPACT
The blow-straw remote is a relatively inexpensive and
versatile device that provides individuals with quadriplegia the freedom to change their environment even
when they are alone. The ability to connect additional devices to the remote in the future will allow
the client to continually expand his/her environmental interaction and control.
The blow-straw remote was designed to accommodate a particular client, but could be used by almost
anyone who is seated upright in a chair or recliner.
The design constraints presented specifically by our
client were that it: 1) be operational without using
any body motion except head movement; 2) not use
Figure 5.37. Operator’s View of Remote Control
Housing.
text labels or displays, due to the client’s poor vision;
3) be adjustable such that it will accommodate a variety of different chairs that the client may choose to sit
in; 4) be universal and able to adapt to new audio/video equipment; 5) not require assistance at any
point beyond its initial set up, because the client is
alone for most of the day; and, most importantly, 6)
be safe.
The frame for the remote control is H-shaped, and has
two vertical posts with bases and a cross-member.
The vertical posts are two 40” tall 1¼” PVC members,
anchored by aluminum bases. The bases are cylindrical, each 12” in diameter and 1” thick. They are
mounted to the posts using steel flanges and four
bolts. The cross-members consist of two horizontal
36” long 1¼” PVC members that span the width of the
chair or recliner. These members are connected to the
posts by four 45-degree elbows and short PVC extensions, which lead into two modified “slip V’s”, one
on each post. PVC platforms and rubber stoppers, in
conjunction with hose clamps, are used to adjust the
height of the slip V’s. This allows the height of the
cross-members to be finely tuned as opposed to being
adjustable in increments.
The remote box was built using 1/8” thick sheet PVC
and assembled using L-brackets and mounting
hardware. The final box dimensions are 10” x 14” x
4”. Sheet PVC is also used to wall off two separate
compartments in the box, one that holds the remote’s
circuitry, and another that houses the blow-straw
switches. This is a safety feature to prevent moisture
from coming into contact with the circuitry.
Two access doors are built into the box, one to access
each compartment. The remote circuitry is from a retail universal remote control with logic gates that decipher input from the blow-straws. The blow-straws
are ¼”-diameter tubes that lead into the box and into a
larger air diffuser. A plunger in the diffuser depresses a switch when the client blows on the tube.
These switches are wired into the remote circuitry in
the other compartment.
The remote box is attached to the cross-member by
four custom made U-mounts that permanently attached to the bottom of the box. These mounts snap
over the cross-members and hold the box in place,
while allowing the box to be easily removed or slid
across the cross-members. A large digital clock is also
mounted on the cross-members using a sheet PVC
platform and two custom made U-mounts.
For safety reasons, all edges on the remote box and
frame were filed and/or rounded. Also, 1¼” PVC
caps were mounted on the tops of both vertical posts.
The caps enhance the frame’s appearance and cover
the rough edge of the open-ended PVC members. A
client with quadriplegia tested the frame and box for
use and found the apparatus to be effective. It has
been suggested that we also install vents in the blowstraw compartment of the box to avoid moisture accumulation and improve safety.
A 7.5V AC/DC adapter powers the circuitry of the
logic circuit. Using a low voltage DC source decreased the chance of shock or electrocution. The
universal remote circuitry is powered by two AA
batteries, which also have a minimal shock potential.
The digital clock is a separate unit, powered by a
standard AC plug. The clock does not constitute an
electrical hazard.
The final cost of the remote device is approximately
$115.00, not including labor charges. Many of the
components were made from scrap materials available at no cost.
WHEELCHAIR SWING
Designers: Jamie Kimberley, Michael Maelum, May Ng
Client Coordinators: Mary Odel, BOCES at Appalachian
INTRODUCTION
A wheelchair swing (Figure 5.38) was designed for
children with disabilities. The swing moves in a parallel motion to the floor and is powered by human
force at the present, but can be modified in the future
to accommodate other power sources. The unit was
built to be easily disassembled and stored.
SUMMARY OF IMPACT
The wheelchair swing provides clients new opportunities for stimulation and a recreation during their
indoor classes. It was designed for school-age children, but could be beneficial to others.
The main design requirements were that the wheelchair swing: 1) be as small as possible, due to the limited amount of classroom space; 2) be portable, easily
disassembled and stored out of the way; 3) accommodate all sizes and types of wheelchairs; 4) be safe to
use.
The swing has two main components, the frame and
the platform. The frame is a rectangular structure
consisting of 1-5/8” steel conduits connected with
cast aluminum fittings. These structural pipefittings
secure the pipe via allen bolts. Connected to the
frame are two 1/8” plastic coated steel cables to stabilize the swing during motion. The platform is a 30” x
50” x 3/4” piece of plywood reinforced with steel and
connected to four supporting 1/8” plastic coated steel
cables for stability. Connecting the cables are 1/8”
cable clips, 3/8” spring snaps, and 5/16” eyebolts.
The clips allow for quick disassembly. There is also a
small railing on the platform and tie-down straps on
the platform to immobilize the wheelchair to the platform. A small ramp has been attached to the platform
to load and unload the client.
Tests of the swing were conducted by having members of the design team weight the platform to the
simulated weight of the clients while the swing was
in motion. A design change for the future is to develop a freestanding swing that is portable for indoor
and outdoor use. The swing might also be motorized.
The final cost of the wheelchair swing was approximately $165.
Figure 5.38. Wheel Chair Swing.
CHAPTER 6
DUKE UNIVERSITY
School of Engineering
Department of Biomedical Engineering
Durham, North Carolina 27708-0281
Laurence N. Bohs (919) 660-5155
[email protected]
77
SENSORY STIMULATION ACTIVITY CENTER
Designers: Anna Fernandez, Elaine Hsieh, & Wesley Joe
Client Coordinators: Mary Caldwell & Lenore Champion
Duke Hospital Pediatric Rehabilitation Center
Supervising Professor: Dr. Laurence N. Bohs
Duke University
Durham, NC 27708
INTRODUCTION
dren. Currently, similar products make the
A Sensory Stimulation Activity Center (SSAC) was
developed for use in the treatment of children under
three with Down’s Syndrome or closed head injury.
Studies suggest that sensory stimulation helps to
promote development in these children. The bear interacts with the child, reinforcing cause-effect relationships between a button press and sensory stimulation.
SUMMARY OF IMPACT
Most existing sensory stimulation activity centers are
costly, only stimulate up to three senses, and are
housed in simple plastic boxes. This activity center is
housed in a stuffed bear and stimulates visual, auditory, olfactory, and tactile senses. The bear is visually
appealing and fun for children of varying motor
skills. It allows children to enjoy themselves while
learning cause-effect relationships under the supervision of a therapist.
Therapists who use the SSAC praise its benefits:
“The Pooh is so colorful and friendly that all
of my children want to keep him for their
own.”
“The Pooh helps the most with our physically and visually impaired children. These
children are not given the normal access to
exploratory play that physically normal children do. Because of that, they are unable to
learn independently as other kids do. We use
Pooh to stimulate the senses of smell, sight,
sound, and touch.”
“This is a much-needed toy. It will definitely
be very useful to our therapy of these chil-
Figure 6.1. A Child Using the Sensory Stimulation
Activity Center.
kids easily bored. This toy not only keeps
their attention, but is also very cuddly and
fun to play with.”
The active components of the device are housed in a
stuffed bear. Two “C” batteries connected in series
power the SSAC. A control panel on the bear provides
the user interface for activation of the stimulation activities.
Activation of the functions is through momentary
contact,
normally-open push-button
switches
mounted on the control panel. The buttons have different colors and shapes. Adjacent to each button is a
picture and a light emitting diode (LED) with the
same color scheme as the button. Each of the four buttons, four lights, and four pictures is associated with
a stimulation activity: releasing scented air, blowing
air, vibrating the arm, and playing music. The picture
located next to each button represents the activity
powered when the button is pressed. When a button
Chapter 6: Duke University 79
is pressed and held the adjacent LED illuminates and
the function is activated. When the button is released
the function stops immediately.
Each button is connected to the power supply via the
main power switch (see Figure 6.2). In parallel with
each button is a 1/8” jack for an external switch.
This allows either the control panel button or the external switch to activate each function. In series with
each button are the corresponding LED and a current
limiting resistor. The components for the stimulation
(external jack)
activity functions are activated in parallel to the LED
circuits.
The control panel is made of plastic reinforced by ¼”
acrylic sheets. Items on the front face of the panel are
mounted onto the plastic control panel and on the
acrylic sheet reinforcement. All circuitry is housed
within the control panel box. Circuit components are
soldered onto a perforated circuit board.
LED
150
BLOWING AIR
FAN 1
(external jack)
LED
150
VIBRATION
MOTOR 1
(external jack)
LED
150
MUSIC
MELODY
(external jack)
150
5.1
SMELL
Main
On/Off
Switch
1.5 V
LED
FAN 2
SMELL
ISOLATION
UNIT
10uF
1.5V
Figure 6.2. Circuit Diagram of Main Activities.
.1uF
For the smell activity, a forked tube allows the passage of air from the box to the outside of the mouth. A
removable air freshener cartridge housed in an isolated chamber provides scented air. While the activity is not on, a plastic flap blocks the smell from the
tube leading to the mouth. When the button is
pressed, a voltage pulse from a monostable multivibrator (74HC221A) causes a motor to raise the flap,
exposing the tube. A fan then blows the scented air
out to the mouth. When the button is released, the
multivibrator emits another pulse, the motor returns
the flap to its closed position, and the fan turns off.
This circuit is shown in Figure 6.3.
mize airflow through the bear’s mouth. A vibration
unit was constructed using a motor spinning an offcenter mass in order to produce a shaking effect when
mounted in the bear’s arm. The unit is housed entirely in PVC plastic to increase robustness and
safety.
A box located inside the bear’s head contains the
components for the smell and air blowing functions
(see Figure 6.4). A centrifugal fan was built to maxi-
The approximate cost of the Sensory Stimulation Activity Center was $340.
The musical component comes from a commercial toy
that plays a melody for a specific time when
squeezed. The component was modified to play continuously when powered by the button. A piezo
speaker from the same toy is mounted near the surface of the bear’s fur.
+3V
43K
1K
390K
3.3uF
220K
2
3
10
2N3904
1
.1uF
.1uF
9
7
82K
3.3uF
82K
6
15
3.3uF
14
16
B1
CLR2
CLR1
Q1
B2
Q1
11
180
4
13
Motor
A2
+3V
Rext2/Cext2
Cext2
Q2
12
180
Rext1/Cext1
Cext1
Vcc
Q2
GND
MM74HC221A
.1uF
Figure 6.3. Circuit Diagram for Control of Smell Isolation Unit.
2N4401
180
A1
2N4403
5
8
2N4403
180
2N4401
TOP VIEW
FRONT VIEW
Air freshener cartridge
Air freshener cartridge
Smell fan
Smell isolation
motor
Plastic Flap
Centrifuge fan
Plastic flap
To mouth
Figure 6.4. Diagram of Air Blowing and Smell Activities.
To mouth
Smell isolation
chamber
CHILD-FRIENDLY ACTIVITY TIMER
Designers: Sean Breit, Stephanie Liu, Srinivasan Yegnasubramanian
Client Coordinator: Lenore Champion, Duke Hospital
Duke University
Durham, NC 27708
INTRODUCTION
and physical display (see Figure 6.6). The input ac-
The electronic Child-Friendly Activity Timer (CFAT)
was constructed for use in pediatric therapy sessions.
The CFAT features a small rabbit moving across a hill
toward its burrow, and a digital display that shows
the time remaining. When time expires, a beeper
sounds and the rabbit returns to its starting location.
SUMMARY OF IMPACT
Generally, for timed sessions, a therapist sets an electronic kitchen timer that beeps when time is finished.
However, most young children do not have a clear
concept of time and cannot understand how much
longer their practice sessions should continue. The
CFAT was created to provide children with a visual
and qualitative measure of time during therapy sessions.
The client is a two-year-old with a feeding disorder.
Part of his prescribed therapy includes timed feeding
sessions, where he is required to practice activities,
such as holding his spoon and drinking from a cup
for specific periods of time.
The CFAT is a microprocessor-controlled device that
contains both a numerical and physical display of the
progression of time. The user programs the CFAT using six pushbuttons. Three buttons set the time in increments of 30 seconds, one minute, and 10 minutes.
The other three buttons start, stop, and clear the timing process. The microprocessor reads from these six
pushbuttons and controls the time displayed on a 4 ½
digit LCD 7 segment display as well as the movement
of a toy rabbit, attached to an arm on the shaft of a servomotor.
The CFAT consists of three sections: 1) input acquisition; 2) time and display processing; and 3) numerical
Figure 6.5. The Child-Friendly Activity Timer.
quisition section contains the pushbutton hardware
and the software required to process user input. The
pushbuttons connect to the data lines on a Z-180 microprocessor (Z2 Prototyping board, ZWorld, Inc,
Davis, California) through a tri-state latch
(74HCT373). The six-bit binary number representing
the state of the pushbuttons is translated into an instruction by the microprocessor. The program contains de-bouncing routines that prevent the microprocessor from reading unintentional input. Additionally, the input software prevents the user from
making logistical errors, such as accidentally clearing
the time remaining during operation without first
stopping the timer.
The time and display section controls a countdown
timer and the servomotor. The countdown timer uses
the real-time clock on the Z2 board to calculate the
time remaining. The servomotor is controlled using
an 8-bit binary number that increases at a constant
rate determined by the input time. This binary number is converted into an analog current using a digital
to analog converter (DAC0832), and then converted to
a voltage using a single-sided operational amplifier
circuit (LM358). This varying voltage is translated
into a square wave with linearly varying pulse width
using a voltage-controlled oscillator (CD4046). The
square wave is connected to the control line of the
servomotor. The servomotor moves through 30 steps
over an angle of 120o.
power consumption since the servomotor only operates for 30 seconds, regardless of the input time. Finally, a small buzzer sounds when the time is finished.
The CFAT uses four C batteries in series to provide a
6V DC supply, which powers the servomotor and the
buzzer directly. The 6V DC is regulated to 5.2 volts to
power the microprocessor and the other IC's.
The output section comprises a numeric display, a
physical display and an audible buzzer. The time is
displayed on a Varitronix 4½ digit LCD display. This
display is controlled using 32 serial bits from a
MM5452 controller chip. The serial clock and count
data are generated by the microprocessor. The physical display is a toy rabbit attached to the shaft of the
servomotor. To conserve power, a transistor switching circuit turns off the servomotor whenever it is not
being moved. This feature dramatically reduces
The final cost of the Child Friendly Activity Timer
was approximately $380.
+5V
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4.7k
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Voltage Regulator Circuit
15
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7
Figure 6.6. Timer Schematic.
2
180
osc. in
backplane out
backplane in
1
U9
+5V
19
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black
/CS6
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1.40
data enable
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output 1
control
clock
serial clock
serial data
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17
16 5 7 9 11 13 15 27
0 1 2 3 4 5 6 7
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U1
VI-509-DP
DISPLAY
COM
COM
COMPUTER GAMES FOR LEARNING JOYSTICK
CONTROL
Designers: Pinata Hungspreugs and Becky Poon
Client Coordinator: Robbin Newton
Lenox Baker Children’s Hospital
Duke University
Durham, NC 27708
INTRODUCTION
ary to allow the child to learn how to handle the joy-
Two joystick-controlled computer games, “Catch the
Butterfly” and “Bump & Go”, have been developed to
train children to use powered wheelchairs. Compared to other wheelchair trainers currently available,
these games are more fun to play. They also provide
feedback concerning the child’s progress to the therapist. The software can be shared to enable the child to
practice at the hospital with the therapist, or at home
under a parent’s supervision.
SUMMARY OF IMPACT
Since most powered wheelchairs use joystick control,
it is helpful if children learn to operate a joystick prior
to trying a powered wheelchair. “Catch the Butterfly”
and “Bump & Go” help improve joystick skills because they are fun to play and motivate the child to
improve performance. In addition, statistical data
may be used to evaluate whether a child has difficulty
stopping or moving in a certain direction.
The computer games are written in Visual Basic 5.0
for IBM compatible computers. These games require a
Windows 95 operating system, 4 MB free hard drive
space, and a sound card with a joystick port
“Catch the Butterfly” helps beginners and younger
children become adjusted to using a joystick. In this
game, the child manipulates, on the screen, an image
of a boy holding a net. The object is to catch a butterfly. To encourage the child, a reward screen using
visual and audio stimuli is shown each time a butterfly is caught. The game contains three levels of difficulty. In the first level, the butterfly remains station-
Figure 6.7. Screen for the Bump & Go Game.
stick. In the second level the butterfly flies around the
screen. This allows the child to practice following an
object and moving the joystick in different directions.
The third level features a bee (see Figure 6.7) that the
child must avoid while attempting to catch the butterfly. If the boy is “stung” he is moved further away
from the butterfly.
“Bump & Go” is a more challenging game that acquires statistical feedback on the progress of the child.
There are four levels of increasing difficulty. Each
level consists of a car that the player must move with
the joystick to reach his or her “destination,” an image that appears in random positions on the screen.
The player drives the car from the starting point in
middle of the screen to the destination. Walls act as
barriers between the car and the destination, except in
the first level. With increasing levels, the number of
walls increases and the size of the openings between
them decreases. Though the images appear randomly,
they are placed in specific areas of the screen. This al-
lows the therapist to determine if the child is having
trouble moving the joystick in a particular direction.
“Bump & Go” contains a stop sign function that records the amount of time it takes for the child to stop
moving. A timer also records how long it takes for the
car to reach each destination. This information is
saved in a file to allow the therapist to evaluate
whether the child is having difficulty moving in a
particular direction.
A scoring system is implemented in “Bump and Go”
in order to motivate the child. The final score is determined according to the amount of time the child
requires to reach the destination image and the number of objects the child hits during the game.
Each object in these games is a represented by a bitmap image. Its position in the game field is given by
the object’s x and y coordinates with respect to the
upper-left corner of the field (0,0). Visual Basic 5.0
automatically calculates many properties of the object
in the program including the height, width, and coordinates of the top, bottom, right, and left edges of
the image.
To make the game more entertaining for the child,
colorful animated images were used (e.g. the boy in
“Catch the Butterfly” runs around the screen). This
requires a series of images, each slightly different,
which create the effect of movement when rapidly alternated (i.e. like a flipbook.) Joystick control is given
to the characters using the program joystick.exe from
Mabry Software (Stanwood, WA), which returns the x
and y coordinates of the joystick. These values are
used to position the image on the screen. When the
joystick moves a certain distance in one direction the
function Joystick1_Move is activated and moves the
object (the car or the boy with the net) in the direction
the joystick is pushed. The distance the image moves
can be increased or decreased by changing the number of pixels the image shifts when the function is
read. The program also ensures that the image does
not move off the screen.
The games must be able to identify collisions between
two images on the screen. The functions Collided, HitUpDown, HitLeftRight, and LtRtShort detect the collision of two objects. Collided obtains the coordinates
of the right, bottom corner of two bitmaps, which are
then passed to the Windows API function called In-
tersectRect. This function will return 0 if the two images do not overlap. If they do overlap, IntersectRect
returns a 1. This invokes the reward screen that is
controlled by the function Timer2. Collided is used in
“Catch the Butterfly.”
To detect collisions between the car and walls or destinations in “Bump & Go,” the functions HitUpDown,
HitLeftRight, and LtRtShort are used. In these functions, the coordinates of the car are compared to each
object on the screen by a series of if–then statements to
see if they are touching each other. If the car touches
a block, the position of the car changes so it
“bounces” back from the wall. If the car touches a
destination point, Timer2 is invoked and the reward
screen appears.
A function was written to record the time it takes for
the child to move the car from the starting point to the
final destination. When the car appears on the screen,
the command Timer, which captures the time of day
in seconds, is called and is saved as Start. Timer is
then called when the child reaches the destination
image and the time is saved as Finish. The difference
between Finish and Start is used to determine the average time required to reach each destination on the
screen. This information is then written to a file
specified by the therapist if he/she chooses to record
the data.
Though the games are in good working condition and
satisfy the original objectives, there are several components that could improve the project. Improvements could be made on the feedback information for
the therapist and time analysis. One way that this
could be done would be to consider the speed of the
car. If the car is set to a higher speed, the car will
reach the destination more quickly, and the average
time might not be a good indicator of performance. It
may be useful to implement a performance gauge
function that averages speed and time. This could be
coupled with an evaluation screen that would give
suggestions to the therapist on what the child should
work on and if he or she is ready to play at a more difficult level.
The total cost of this project was $195, including the
cost of the joystick and sound card for the PC.
AUTOMATIC FEEDER MODIFICATIONS AND
WHEELCHAIR-TO-BED TRANSFER APPARATUS
Designers: Atif Haque & Kulbir S. Walha
Client Coordinators: Robbin Newton and Tonya Hamm
Lenox Baker Children’s Hospital
Duke University
Durham, NC 27708
INTRODUCTION
An electric feeder was modified and a wheelchair-tobed transfer apparatus was developed for a young
man with cerebral palsy in order to increase his independence in everyday activities. A ceiling mounted
transfer bar was created to allow the client to transport himself between his bed and wheelchair.
SUMMARY OF IMPACT
The client is a 20-year-old man with cerebral palsy
who uses a wheelchair. Because of his muscle control
limitations, he previously had to be fed by his parents. The modifications made to the Winsford feeder
now allow the client to feed himself.
His disability, along with injuries he suffered in a recent car accident, make it impossible for him to get
into and out of his wheelchair from his bed without
assistance. At the client’s suggestion, the transfer apparatus was built, allowing him to move himself between his bed and wheelchair.
These items have reduced the client’s dependence on
others in his daily life. He comments, “I enjoy the independence (the feeder) gives me to be able to feed
myself. Sometimes I get a little messy but that’s ok. I'm
sure my mom enjoys getting a break from feeding me
everything that I eat. I continue to enjoy the transfer
bar in my bedroom. It is a big help when I get in and
out of bed. These projects that you developed for me
have been very beneficial.”
A damaged Winsford feeder (Klemco Engineering,
Plumsteadville, PA) was donated and repaired to
make it operable. A new clamp was designed and
constructed from aluminum block to allow the Buddy
Bar to attach to the client’s new wheelchair, which
was purchased after his automobile accident. The
Buddy Bar allows table-mounted devices, such as a
computer, to attach to the wheelchair.
To accommodate the feeder, a Plexiglas plate was designed to fit tightly into the feeder’s base. A key
mechanism was designed from aluminum to slide
and lock into place on the Buddy Bar lock plate. In
order to increase stability, a Velcro strap wraps
around the arms of the wheelchair and connect at
both ends to the base of the feeder.
The client and his father noted other possible improvements that might be made to the feeder. The mechanical arm lifted the food in an arc that extended
past the plate. Hence, any spilled food fell onto the
client’s lap. To fix this shortcoming, the feeder was
modified as follows. To control the topmost point in
the feeder's arc, the pentagonal cam of the feeder was
positioned so that the slanted side was flush to the
feeder when the arm was in its apex. To keep the arm
angle suitable for picking up food, an adjustable stop
was constructed out of aluminum and attached to the
feeder's surface below the arm. The cams were also
altered so the lifter stopped at the angle the client desired.
The spring mounted in the utensil holder was replaced with a rigid, stainless steel tube to improve the
client’s ability to eat without spilling food. In order to
increase the amount of food that the lifter would carry
during each cycle, a modified utensil was made. The
initial utensil was a spoon; however, it did not lay
flush against the plate when the lifter arm was in the
down position. The spoon was replaced with a spork
(a spoon with prongs on its end). The spork was
used because it has a much flatter tip than any available spoon. The spork was flattened and its prongs
were rounded. The modified utensil consistently
picks up almost twice the amount of food per cycle as
the original spoon. The transfer apparatus (Figure
6.8) uses an arm consisting of a rod within a tube,
both constructed of stainless steel. The inner rod has
tapped holes at 2” intervals, allowing the height of
the handle to be adjusted by aligning it with screws
placed through holes in the outer tube. The handle is
constructed from 1" diameter stainless-steel rod to
provide an adequate grip diameter for Ray. The top of
the pipe is connected to a universal joint from
McMaster-Carr Supply Company (Atlanta, GA). The
original joint only provided a 25o angle of vertical motion and very limited rotation. The vertical angle was
increased to approximately 80o by grinding the joint's
surface. 360o rotation was enabled by using a thrust
bearing from Dixie Bearing Co. (Durham, NC). The
transfer apparatus was mounted to the ceiling of the
client’s bedroom using a custom plate constructed of
1 x 4 x 20” aluminum block, which distributes the
load across two ceiling studs above the bed. Holes in
the plate allow the transfer apparatus to be mounted
in three locations relative to two ceiling studs. The
estimated cost of the feeder modifications was $185.
The complete transfer apparatus cost approximately
$170.
Figure 6.8. Bed-to-Wheelchair Transfer Apparatus.
POOL CHAIR
Designers: Julianne Hartzell and Jennifer Peters
Client Coordinators: Beth Hildebrand and Cherie Rosemond
Carol Woods Retirement Community
Duke University
Durham, NC 27708
INTRODUCTION
A wheelchair was designed and constructed to enable therapists to transport patients into and out of a
pool.
SUMMARY OF IMPACT
Previously, therapists had difficulty moving elderly
patients into and out of a pool for therapy sessions.
The wheelchair previously in use had small wheels
that made movement on the rubber matting surrounding the pool difficult or impossible, requiring two
therapists to lift patients seated in the chair.
The new chair, with its larger wheels, can be maneuvered easily by one person and is safer than the previous chair. Lifting is not required. The braking
mechanism allows the chair to be fixed in position
once in the water, and is easily operated from the
back of the chair by the therapist. Finally, the wheelchair is equipped with a dark green webbed seat in
order to improve its visibility in the pool water.
This chair makes transport into and out of the pool
safer and more enjoyable for both patient and therapist. A physical therapist who has used the pool
chair with patients says, "I feel safe with residents
when I use the chair. It maneuvers easily over various surfaces and I can push it up the ramp by myself.
Residents like the seat belt feature and the chair stays
put at the bottom of the ramp… all positive changes
over any off the shelf chair we could find."
The pool chair (see Figure 6.9) was designed to assist
a person weighing up to 250 pounds into and out of a
pool. It was constructed for easy mobility and control
around a pool and also provides a simple and effective safety latch.
Figure 6.9. The Pool Chair.
The frame of the chair is made of 1 ¼ inch diameter,
schedule 40 PVC pipe (see Figure 6.10). 3/8-inch
holes are drilled in the bottom pipes to allow water to
enter the chair once in the pool and drain the chair
when exiting the pool. This prevents the chair from
floating and allows the patients to easily get back into
it after therapy. 1/4-inch holes are drilled in the top
pipes to allow air within the chair to escape as it fills
with water. Front safety bars with ring connectors are
attached to one side of the chair. The bars pivot hori-
zontally from this side and attach with spring pins to
the other side of the chair. The front wheels are fourinch diameter plastic casters. The rear wheels are
1/8-inch diameter plastic wheels with mold-on rubber tires and Delrin bearings. They are attached to the
chair by a ¾-inch nylon axle that is reinforced by four
nylon sheaths over the section of the axle between the
wheels. The wheels are held onto the axle by small
outer caps bolted to the axle. The seat and backrest
are made of vinyl coated polyester fabric. The seat is
cushioned and has a seatbelt. A curved PVC bar supports the seat.
tubing. The handles are attached to nylon hollow
tubing by a pivot. The entire brake system is attached
to the chair by a ring of PVC glued to the frame and
held in place by two screws. When the handles are
turned, the pivot drives the nylon tube into the wheel
well. The wheel is held stationary when the nylon
rod comes into contact with the spokes of the wheel.
This contact prevents any further motion of the wheel.
The end of the hollow nylon tube is sectioned so that
it will fit inside the wheel well.
The total cost of the pool chair was approximately
$280.
The brakes of the chair have two handles, one for
each wheel. Each handle is made of a length of PVC
Top
Front
Side
Figure 6.10. PVC Frame of the Pool Chair.
CHAPTER 7
MANHATTAN COLLEGE
School of Engineering
Mechanical Engineering Department
Riverdale, NY 10471
Daniel W. Haines (718) 862-7145
[email protected]
91
AUTOMATED DIE ROLLING DEVICE
Designers: Maribel Cruz, Stephan Rutgerson, Suzanne Wright
Client Coordinators: Laura Meza, Dan Schipf
Brandywine Nursing Home, Briarcliff Manor, NY
Supervising Professor: Dr. Zella Kahn-Jetter
Manhattan College
Riverdale, NY 10471
INTRODUCTION
A device was designed so that residents of a nursing
home could reliably roll dice with the push of a button or activation by breath control.
SUMMARY OF IMPACT
The Automatic Die Roller is now in the recreation
room of the nursing home where the residents and
caregivers find it rewarding to use.
The Automatic Die Roller is contained in a square
polystyrene box with a sloping roof. The lid is hinged
to allow access to the interior.
Figure 7.2 shows the two dice resting on the platform
that flips the dice upward. The platform is activated
by a push-type solenoid. A side cut-away view of the
device is shown in Figure 7.3.
The cost of the Automatic Die Roller is $147.73.
Figure 7.1. Automated Die Rolling Device.
Figure 7.2. Close-up Showing the Two Dice Resting
on the Platform.
Chapter 7: Manhattan College 93
CLEAR POLYCARBONATE
SHEET (1/4 INCH THICK)
GAME PIECE
COMPARTMENT
SECURING LATCH
HINGES (2X)
SAFETY
CONTACT
SWITCH
120V PUSH
BUTTON
SWITCH
MOMENTARY
PLATFORM
WIRE NUT
SOLENOID
(120V AC)
STRAIN RELIEF
AND 120V
POWER CORD
POTENTIOMETER
(120V AC)
ADAPTER PLUGS FOR CUSTOM SWITCHES
Figure 7.3. Side Cut-Away View of the Automated Die-Rolling Device.
RUBBER FEET
SOLENOID HOUSING
SOLENOID MOUNTING
BRACKET
VENTILATING SYSTEM FOR A NURSING HOME
GREENHOUSE
Designers: Michael Donaghue, Jennifer Grzan, Stephen Grzic
Client Coordinators: Susan Holmes, Dan Schipf
Manhattan College
Riverdale, NY 10471
INTRODUCTION
During their initial visit to a nursing facility, the designers were shown the greenhouse where many
products built by previous Manhattan College students are in use. They noticed that the ventilation
system in the greenhouse was noisy and the room
was very warm. A project to improve the situation
was defined.
Fan and
Exhaust
Louver
Electrical Wiring
Motorized
Intake
Damper
21 feet
SUMMARY OF IMPACT
The existing exhaust system was evaluated. It was
determined that adding new components and retrofitting others would result in a quieter, more efficient
exhaust fan. The greenhouse is now much more
pleasant with the new equipment in place.
The new exhaust system consists of a motorized
damper intake and a fan with an exhaust louver. Figure 7.4 shows the position of these elements in a plan
view of the walls of the 15 X 21 ft rectangular greenhouse room.
A Dayton 4-wing aluminum blade Venturi fan was
selected for the fan element. The fan is powered by a
1/4 HP electric motor. It has a 10-inch propeller diameter and is encased in a 12-inch frame. At 1140
rpm the fan draws air at a rate of 945 cubic feet per
Figure 7.4. A Ventilating System for the Nursing
Home Greenhouse.
minute. This installed fan is shown from the interior
of the room in Figure 7.5.
To create negative pressure, a 23 X 23-inch motorized
damper was selected. The damper is wired so that it
opens automatically whenever the fan on the other
side of the room is turned on. The damper incorporates a bug screen. Figure 7.6 shows the damper in
the closed position behind the three designers.
The cost of the Greenhouse Exhaust System is
$359.25.
Figure 7.5. Installed Fan Shown From Interior.
Figure 7.6 Designers and Device with Damper in Closed Position.
MODIFICATIONS AND ENHANCEMENTS TO A
CONSOLE TV STAND
Designers: Alper Basoglu, Leon Fendley, Christopher Sheridan
Manhattan College
Riverdale, NY 10471
INTRODUCTION
A nursing home’s large-screen television required a
more stable and versatile base.
SUMMARY OF IMPACT
The residents and staff now have a television system
that can be safely raised and moved about the floor
more easily. This has eased burdens on the staff.
Figure 7.7 shows two of the three designers with their
product. The base is a trapezoidal box made of wood
and covered with carpeting. Wheels on the base
make horizontal movement easy. Two sets of safety
straps
Figure 7.7. Portable TV Stand.
prevent the television set from tipping.
The cost of the materials for this project was less than
$250.
ENHANCED ELECTRONIC TV CONTROL
SYSTEM
Designers: Eric Glatzl, Stephen Lebron, Gregory Pascal
Manhattan College
Riverdale, NY 10471
INTRODUCTION
A patient with quadriplegia has had difficulty operating a conventional remote control device for the television set in his room. He requested a device
mounted to his bed rail that would enable him to operate the TV more easily.
SUMMARY OF IMPACT
The designers developed a working device with
which the patient is pleased.
Fig. 7.8. Top View of the Easy Touch Remote Control.
The designers determined that a box with eight large
buttons could serve the needs of this patient, provided that the device performed the following functions: Power on/off, Channel up/down, Volume
up/down, Television toggle switch, Cable box toggle
switch, and Channel recall. Figures 7.8 and 7.9 show
the control box with the buttons.
The cost of the Easy Touch Remote Control is
$492.93.
Fig. 7.9. Side View of the Easy Touch Remote Control.
A TABLE-SIZE ROULETTE WHEEL
Designers: Anthony Ferrara, Timothy Kim, Man Phan
Client Coordinator: Dan Schipf
Manhattan College
Riverdale, NY 10471
INTRODUCTION
During a visit to a nursing home, the designers observed that residents needed more varied recreation.
Designers from Manhattan College had previously
constructed a wheel of fortune for the residents. After
consulting with the client coordinator, these designers decided that a roulette wheel would be well received.
SUMMARY OF IMPACT
Although it was initially too large for the entrance,
the roulette wheel was subsequently modified. The
residents are pleased with the device.
Figure 7.9. Roulette Wheel.
The design includes two tables, one for the numbers,
and the other for the roulette wheel. The heights were
set so that residents in wheelchairs could fit beneath
them. Figure 7.9 shows the first table.
Figure 7.10 shows the table in which the wheel is
mounted. The walls were set high to prevent the ball
from leaving the table when in operation. A motor,
connected by a belt and pulleys to the spindle beneath the table, spins the wheel. Rotation of the
wheel is initiated by a standard switch, button switch
or breath control switch. The table is covered with
Plexiglas to prevent the ball from escaping. A contact
switch prevents the motor from operating unless the
cover is in place.
Figure 7.11 shows the motor assembly.
The cost of the Roulette Wheel is $354.66.
Figure 7.10. Table in which Wheel is Mounted.
Figure 7.11. Motor Assembly.
A PNEUMATIC TV CONTROL SYSTEM
Designers: Michael Christopher, Scott Sharp, Alexander Miranda
Manhattan College
Riverdale, NY 10471
INTRODUCTION
The designers modified a TV remote control device for
use by people with physical disabilities. They chose
to apply pneumatic technology to develop a device
that could be easily controlled by breath activation.
SUMMARY OF IMPACT
The pneumatic TV remote control device operates
well and reliably.
Figure 1 shows the pneumatic remote control. It consists of three tubes mounted on an adjustable arm and
connected to pressure switches. It was determined by
experiment that a pressure switch setting of 3” of water is adequate for both sip and puff operations. Each
of the three tubes and switches control one of the following functions: Power on/off, Channel up/down,
or Volume up/down.
A schematic diagram of the Pneumatic Remote Control is shown in Figure 7.13.
Figure 7.12. Pneumatic Remote Control.
User Huff
and Puff
Input
Power
Channel
Volume
Pressure Switch
High (typ. for 3)
Pressure Switch
Low (typ. for 2)
Switch Box
Approx. 4" x 7"
HIGH
HIGH
LOW
LOW
Standard 9-Pin
Connector
Figure 7.13. Schematic Diagram of the Pneumatic Remote Control.
HIGH
CHAPTER 8
MISSISSIPPI STATE UNIVERSITY
T.K. Martin Center for Technology and Disability
P.O. Box 9736
Mississippi State, MS 39762
Gary M. McFadyen (601) 325-1028
[email protected]
103
TRAIL READY UTILITY VEHICLE FOR PEOPLE
WITH PHYSICAL DISABILITIES
Designers: Jennifer Long, Summer Martin
Client Coordinators: Kris Geroux,
Supervising Professors: Dr. Timothy N. Burcham
Department of Agricultural & Biological Engineering
Mississippi State University
INTRODUCTION
The modern All-Terrain Vehicle (ATV) has increased
the number of individuals participating in outdoor
recreational riding. The ATV is a mainstay for hunters and recreational riders because of its ability to
traverse rough, narrow trails. Unfortunately, many
individuals with disabilities have limited access to
remote areas due to transportation limitations. Some
wheelchairs have limited mobility when operated on
non-firm surfaces, while others are too heavy and
lack the necessary energy reserve to traverse rough
trail conditions. To facilitate safe deep-woods access
for handicapped individuals, the Trail-Ready Utility
Vehicle (TRUV), Figure 8.1, was designed and constructed according to the width of a standard ATV,
thus allowing access on narrow trails.
SUMMARY OF IMPACT
Ease of transportation to and from various hunting
sites is a principal concern for hunters with disabilities. The Physically Challenged Bowhunters of America organization reports that prior to the opening of
the first disabled-only hunting tract in the State of
Virginia, handicapped hunters had to be pushed
through miles of wooded trails. The special features
of the Trail-Ready Utility Vehicle allow individuals
with disabilities to enjoy the outdoors.
A review of present methods of transporting individuals with disabilities to remote wilderness locations, an evaluation of narrow rough access trails,
and an examination of the limitations of disabled individuals yielded the objectives for the TRUV. The
TRUV is to be safe, low-cost, lightweight, ATVtowable, capable of traveling narrow trails, and tai-
lored to the transportation needs of the individual
with disabilities.
The main frame, side supports and side ramp of the
TRUV are fabricated from 2-inch and 1-inch square
steel tubing. Two ATV tires are positioned at the rear
and mounted on rubber torsion axles. This provides
optimum floor space, minimum width and weight,
ease in entrance and exit, and a low center of gravity.
The main frame is constructed of 2-inch square steel
tubing with a 1/8-inch wall. This material is also
used in the tongue and in the frame supporting the
axles. The remaining steel members are 1-inch square
tubing with a 1/12-inch wall. These members in clude staggered ladder bracing in the main frame, vertical side supports, top rail and the ramp framing,
and bracing. The original center X-brace in the main
frame was replaced with two longitudinal members
positioned according to the distance between wheelchair tires. These two members are connected with
additional sections of 1-inch square tubing.
With tires in the rear, stiffness of the 500-pound capacity axle system was tested. For load testing, an
electric wheelchair was obtained from the T.K. Martin
Center at Mississippi State University. With the axles
in the rear, the front region near the tongue experiences the most deflection. Unloaded, the front, left
corner of the floor frame is positioned 12 inches above
the ground. With the new axles hitched to the ATV,
deflection was noted with zero load, with a wheelchair centered on the frame floor, and with the wheelchair and a 190-pound person standing at the left,
front corner. During motion, the vehicle rides comfortably and adjusts well to challenging ground sur-
Chapter 8: Mississippi State University 105
faces at the low speed of 15 mph without causing the
ATV to become off-balance.
The nylon straps, manufactured by Welch Hydraulix
Company, are locked into the steel plates.
The ramp/door of the TRUV is 64 inches x 47 inches.
This provides ease in entering and exiting the TRUV.
A 32-inch panel folds down after the innermost panel
is pulled up to the side. For additional accessibility or
maintenance, the ramp may be removed at anytime.
Figure 8.2 shows the frame of the ramp without the
top surface.
The TRUV satisfies all performance objectives. The
TRUV is 130 inches long, 45 in wide, and stands 46
inches tall. With the addition of the roll cage, side
panels, jack, steel fenders, and camouflage covering,
the TRUV will be an even more valuable tool for the
disabled hunter.
The total construction cost of the TRUV is $1,253.90.
Two steel plates, mounted behind the box frame, provide points of attachment for wheelchair tie-downs.
Figure 8.1. Trail Ready Utility Vehicle (TRUV).
Figure 8.2. TRUV Ramp.
ROLLER WALKER WITH SPRING-ACTIVATED
BRAKING SYSTEM FOR A PATIENT WITH
CEREBRAL PALSY
Designers: Angela Myers and Darby Shook
Supervising Professors: Dr. Gary McFadyen, Dr. David Smith, Dr. Joel Bumgardner, Dr. Philip Bridges, and Mr. Rusty
McCulley
Department of Biological Engineering
INTRODUCTION
A specialized roller walker was designed for a client
with cerebral palsy (Figure 8.4). The individual has
more involvement of the right side, causing him to direct most of his weight to the left side of his body. The
individual possesses only gross motor skills, but is
active and capable of maneuvering a rolling walker.
The frame had to be designed to the patient’s height,
stance width, and stance depth.
SUMMARY OF IMPACT
Individuals with physical conditions affecting their
ability to perform the routine tasks of everyday life often use ambulatory assistive devices. Cerebral palsy
is an example of a disorder that causes reduced muscle performance, which may require the use of an ambulatory assistive device. Walkers are one type of assistive device used to add gait support by providing a
wide base stance and improving stability to anterior
and lateral portions of the body. Although walkers
are effective, not all individuals with disabilities are
able to use standard walkers. Rolling walkers may be
more efficient compared to the standard walker for
people with limited upper body strength.
The material used had to be capable of withstanding
repeated applications of concentrated force. The
wheels had to be able to adapt to common surface
frictions, overcome floor obstacles, and withstand
typical weather conditions. In addition, the two rear
wheels had to be able to withstand the pressure of an
applied brake pad. The brake system had to be easy
to engage with small amounts of force. Finally, it was
Figure 8.3. Roller Walker.
important that the brake stop the rolling wheel effectively without causing damage to the mechanism.
The walker has three main components: the frame, the
wheels, and the braking system. An arm piece and a
seat were added to the frame for comfort. The frame is
a solid rectangular structure consisting of 1'' ASTM
A36 structural steel with welded joints. The walker
stands 31'' high, 21'' wide, and 22'' deep (Figure 8.3).
On the right hand bar is an arm support located 3''
from the front of the structure. An adjustable seat
suspended from the left side of the walker can be retracted across the walker.
The braking mechanism is a push-down springactivated system. A solid steel block with dimensions
of 2.25'' x 1.25'' x .75'' was welded to the base of the
frame. A spring located in a plane perpendicular to
the brake pad allowed for the brake action. When a
force is applied to the frame, the spring compresses
and engages the brake.
The front wheels are made of a hard synthetic rubber
with a diameter of 5'' and a tread width of 1.5''. The
rear wheels have a diameter of 4'' and tread width of
1''. The wheels are made of neoprene rubber and
were obtained from the Darcor Company in Ontario,
Canada.
The welded frame provides adequate support and the
braking system operates effectively.
Figure 8.4. Braking Mechanism.
WHEELCHAIR SEAT WITH AIR ROTATION TO
RELIEVE PRESSURE
Designer: Suzanne Hutchinson
Coordinator: Dr. Smith
Supervising Professor: Dr. Gary McFadyen
Department of Biological Engineering
T. K. Martin Center for Rehabilitation
MSU, MS 39762
INTRODUCTION
A wheelchair seat was designed to relieve and rotate
pressure by alternating airflow through the seat. This
system is portable and can be used by both electric
and manual wheelchairs.
SUMMARY OF IMPACT
Many wheelchair users remain seated in their chairs
for an average of 14 hours a day. If users have no
means of shifting their weight, occlusion of blood vessels can occur in high-level pressure areas of the support surface. By automatic rotation of pressure
points, this seat will prevent such occlusion of vessels
from occurring, especially in the area of the ischial
tuberosities.
The system has two components, the seat cushion
and a control box that straps on the back of the chair
(Figure 8.5). The cushion contains rubber tubes that
inflate and deflate in a set pattern for predetermined
time cycles. The system is designed to support the
user at alternating points on the seated area of contact, decreasing the inhibition of blood flow. A 12volt 7-amp/hour, rechargeable battery powers the
system. The cushion has a foam base to support the
user, in case system failure occurs. Testing with a
pressure mapping system demonstrated pressure relief and rotation.
The seat cushion control box is packaged in a waterproof bag, color-coordinated with the cushion in
royal blue. The seat system was designed for average
user specifications. The weight limit is 150 pounds,
with a safety factor of 2. The seat was designed to be
convenient and easy to operate. One power switch is
Figure 8.5 - Active Pressure Relief Cushion With
Control Box.
placed on the armrest of the wheelchair to control the
system. Once power is on, the cushion is fully automatic. A timer that has two independent time settings
controls rotation. The on time setting activates the
pump and opens one of two solenoid valves. The two
solenoid valves control airflow in two groups of tubes
(Figure 8.6). When the off time setting begins, the
pump is turned off and a latching relay switches the
direction of airflow. When the on time setting begins
again, the pump inflates a different set of tubes. The
first inflated set of tubes gradually deflates through
an exhaust port on the attached solenoid valve.
The cushion consists of a 2-inch foam base of medium-soft foam. Four groups of four tubes lay horizontally on the foam base. The rubber tubes each
have a 1-inch diameter. The groups alternate in an
odd/even pattern of inflation. There is foam support
on all four sides of the cushion. This seat is then covered in a replaceable waterproof covering. The final
covering of the seat is made from 100% cotton, ma-
chine washable, lightweight material. The material
breathes, allowing for moisture evaporation. Velcro
attaches the covering, thereby enabling removal for
washing. Air tubes, 3/8 " Tygon tubing, connect the
cushion to the control box on the back of the chair.
Inside the control box, the tubes are connected to 3way, 2-position solenoid valves. The solenoid valves
are connected to a latching relay that switches power
flow between the two valves. This creates the alternating inflation pattern. The relay and pump are
connected to a timer that has two independent time
settings. When power is supplied, the on time begins
and the pump and relay receive power. When the inflation time is up, the timer switches to its off time cycle. Removal of power turns the pump off and causes
Figure 8.6. - Air Tubes Imbedded in Cushion.
the relay to switch position. When off time is complete, on time begins again, and the pump creates airflow through the other tube groups. The power
switch on the armrest of the chair controls the system.
This system is fully automated and easy to operate.
After a full day’s use, a power cord coming from the
control box can be plugged into an ordinary power
outlet to recharge the battery. Recharging should be
done overnight.
The final cost of this project was $333.00. The T. K.
Martin Center for Rehabilitation provided use of testing equipment at no cost.
CHAPTER 9
NEW JERSEY INSTITUTE OF
TECHNOLOGY
Department of Electrical and Computer Engineering
Newark, New Jersey 07102
Principle Investigator:
Stanley S. Reisman (201) 596 3527
[email protected]
111
PC INTERFACE ENVIRONMENTAL CONTROL
UNIT
Designer: William Cham
Client Coordinator: Susan Drastal, Kessler Institute for Rehabilitation, West Orange, New Jersey
Supervising Professor: Dr. Stanley Reisman
New Jersey Institute of Technology
INTRODUCTION
The purpose of this project was to develop a PC interface to activate an environmental control unit.
SUMMARY OF IMPACT
This device allows the control of appliances, lights,
etc. by means of the PC. Whatever means are used to
control a PC can be used to control the environment.
Since the power line is used for transmission, the control PC can be placed anywhere in the home.
The unit consists of two parts, a PC interface and X10
technology. The PC interfaces with the control unit by
means of an RS 232 cable connected to a serial port of
the computer. Codes from the PC are passed through
the RS232 port to the microprocessor, where they are
converted into X10 codes. These codes are then sent to
an X10 transmitter that puts the codes on the power
line, and are picked up by the appropriate receiver to
control the corresponding device.
X10 technology entails a communications language
that allows compatible products to talk to each other
via the existing 110-volt electrical wiring in the home.
A Lynx 10 microprocessor is used to decode the signals from the PC and send them to the X10 transmitter module.
The signaling sequence consists of 11 bits that in clude a two-bit start sequence, a four-bit house code,
and a 5 five-bit key code. A bit is represented by
bursts of 120 KHz carrier superimposed on the 60 Hz
AC power and is produced by gating the carrier for
about 1 ms., synchronized with the zero crossings of
the 60 Hz signal.
The X10 units are first addressed by sending the
house code and unit code. This operation tells the
units to expect a command. In this way, several units
on the same house code can be addressed simultaneously. Next, a command or series of commands is sent
to the units.
The approximate cost for the prototype unit was $120.
This includes the microprocessor and X10 modules.
Chapter 9: New Jersey Institute of Technology 113
SPEECH RECOGNITION FOR AN
ENVIRONMENTAL CONTROL UNIT
Designer: Guhan Raghu
INTRODUCTION
This project investigated the use of speech recognition
technology to control an environmental control unit.
This unit allows for control of up to four devices.
SUMMARY OF IMPACT
Speech recognition is an increasingly attractive
choice for control of appliances, tools, toys and computers. Persons with disabilities can benefit greatly
from being able to control their environment through
voice commands. With this project, radio frequency
(RF) technology allows control from a different room
or from a different part of the room. The person with
disabilities can therefore remain stationary and control appliances, temperature, and lighting anywhere
in his/her home.
The system consists of three modules: a voice recognition module, a logic circuit with RF transmitter/receiver, and four line carrier decoders. The voice
recognition module recognizes spoken commands
and relays the command to the logic circuit, which
decodes the signal and provides a pulse to the transmitter. The transmitter in turn sends a signal to the
receiver that activates a device, such as a door, lamp,
or television. The hardware was chosen because of its
ease of use and minimal expense.
The voice recognition chip used is the HM2007,
which was trained to recognize four words. Once
trained, a word is spoken into the microphone and a
number 01, 02, 03, or 04 is displayed. The voice kit
was purchased pre-assembled except for the outputs
from the board that would then connect to the logic
circuit.
The HM2007 voice kit has an accuracy of detection in
the 60 to 70 percent range. Although this is not acceptable for a commercial system, it is acceptable for
this prototype system. The fact that the kit comes assembled and is inexpensive made it appropriate for
this project, despite its reduced accuracy. One possible reason for its poor performance is the quality of
the microphone. Future work will investigate the use
of a better microphone. The logic circuit consists of
three sub-modules. The first sub-module receives a
signal from the voice board and classifies it. The second sub-module takes the output of the first submodule and provides a single one-second pulse. The
third sub-module uses the one-second pulse to provide an electronic contact closure for use on the RF
transmitter. The contact closure simulates the push of
a button on a remote control, thereby sending a signal
to the RF receiver. Originally a microcontroller was to
be used instead of the logic circuit. However, no timing information was available from the voice board so
that a microcontroller could not be synchronized with
the voice board. The RF transmitter/receiver module
is connected to the logic circuit. Once a signal pulse is
received from the logic circuit, the transmitter
(RC5000 PHR02 Home Automation Remote) relays
the pulse to the receiver. The receiver (RC5000 PAT01
Home Automation) then sends a signal through the
home’s 120-volt AC circuitry. A line carrier decoder
(PAM01 AGC Appliance Module) decodes the signal.
If that decoder is set to receive that particular signal, it
will turn on the device to which it is attached. The
approximate cost for the prototype unit was $245, including the voice recognition board. Future iterations
of this project may be made less expensive if the voice
board is custom made.
SPEECH RECOGNITION FOR ENVIRONMENTAL
CONTROL OF A WHEELCHAIR
Designer: Michele Raff
Newark, New Jersey
INTRODUCTION
This project is a continuation of the previous project
(Speech Recognition for an Environmental Control
Unit). The goal was to increase the command capability of an environmental control unit to control not
only the environment but also the wheelchair motion
of an electric wheelchair by voice commands. To accomplish this goal, the hardware and software of the
previous project were expanded to allow up to 16
commands to be recognized (the previous project recognized four commands). The device employs RF
technology so that a person using a wheelchair can
control the environment from a different room.
SUMMARY OF IMPACT
People who use wheelchairs may have limited use of
their hands or arms, leaving them unable to control
wheelchair motion or environmental functions. Such
patients whose speech functions are within normal
limits can use speech recognition to perform control
functions. A device that integrates wheelchair motion
control and environmental control would be an asset
to such individuals.
This project is based on the design for the project previously described. A voice recognition board is interfaced to a logic circuit that decodes the voice commands and then controls a transmitter to send a signal to an X10 transceiver, which is connected through
the power line to X10 receiver modules. For this project the HM2007 voice recognition board was used as
well as the HK10A Super Remote Home Automation
System, which includes a 6-in-1 IF/RF remote already
interfaced with two X10 modules, one transceiver
module and one lamp module.
In order to use voice recognition for wheelchair control in addition to environmental control, a sequence
of two or three commands is necessary to achieve the
final result. For example, in order to turn on a light,
the user would say, “lights, turn, on”. This multiple
command sequence adds a great deal of complexity to
the hardware and software.
The approximate cost for the prototype unit was $295,
including the pre-assembled HM2007 voice recognition board. Future iterations of this project would be
less expensive if a custom designed voice board were
used.
CHAPTER 10
NORTH CAROLINA STATE UNIVERSITY
College of Engineering
College of Agriculture and Life Sciences
Biological and Agricultural Engineering Department
D. S. Weaver Laboratories
Susan M. Blanchard (919) 515-6726
Roger P. Rohrbach (919) 525-6763
115
EVALUATION AND TREATMENT TABLE
Designers: Julie Crutchfield and Amanda Fody
Client Coordinators: V. J. Tangella and Ellen Canavan
Tammy Lynn Center for Developmental Disabilities, Raleigh, North Carolina
Supervising Professors: Dr. Susan M. Blanchard, Dr. Larry F. Stikeleather
North Carolina State University
Raleigh, NC 27695-7625
INTRODUCTION
When speech-language pathologists, occupational
therapists, physical therapists, or psychologists work
with children and young adults with severe disabilities, treatment and diagnostic activities often take
place in the therapy room. In order to work effectively
with children and young adults, therapists need a table with adequate space to perform varied activities.
A table was designed to allow adequate space around
and underneath to accommodate individuals in different wheelchairs.
SUMMARY OF IMPACT
The table permits more effective treatment and evaluation for individuals in wheelchairs, and accommodates diverse users.
right of the user, decreasing the distance he or she
would have to reach for something on the table.
Under the rectangular cutout is a solid red oak box,
which houses the brackets that support the tilting
workspace. The dimensions of the box are 20.25” x
13.875” x 2.25”, ample enough not to interfere with
legroom. The bottom of the box has only six inches of
oak extending from each sidewall. Wood does not
cover the entire bottom of the box so that it is easier to
clean. One end of each bracket is fastened to each
six-inch strip on the bottom of the box. The other end
is fastened to the tilting mechanism.
The tabletop (Figure 10.1) is made out of medium
density fiberboard (MDF) covered by polyvinyl chloride (PVC) laminate. MDF is formed by heating and
pressure treating a wood flour and glue mixture. The
board is not like particleboard because it has no air
pockets or small holes within the material. It has the
density of solid oak, which makes the material very
sturdy as long as it is protected from the elements.
The PVC covering provides protection.
The tilting workspace is also MDF with a PVC laminate. It is 18”x 12” x 0.5”. The round is 0.2”, slightly
less than the rounding of the tabletop, so it is flush
with the surface of the table. The top center of the tilt
has an indentation made by a router in the shape of
the flush brass pull ring so the pull ring is flush with
the workspace surface. The flush pull ring is used as
a way to raise and lower the workspace without actually having to hold onto it. This minimizes the
number of pinch point areas on the table. The workspace is attached to the table with one piano hinge.
The brackets are fastened to the back or underside of
the workspace and support it in 14 different positions
that range from 0 to 90 degrees.
The tabletop has dimensions of 45”x 37”x 1”. The
edges are rounded to 0.4” with a router. The surface
of the top has a rectangular area cut out four inches
from the top of the ellipse. This holds the tilting
workspace when it is completely collapsed and
makes it flush with the table. The rectangle measures
18” x 12”. The flattened ellipse that has been removed from the front of the table is 22” x 9”. The ellipse was flattened to create more room for the user.
This also leaves 7.5 inches of tabletop to the left and
The frame for the table is made from 2014-T6 (4.4%
copper alloy) aluminum. The aluminum tubing is 1”
x 1” x 0.25”. The frame is 34” on the short sides, 42”
on the longest sides, and 11” to the left and right of
the cut out. The frame is welded together at each of
the four corners. A weld in each corner of the frame
attaches the aluminum flange legs. The aluminum
flange is made of the same alloy as the frame. Its dimensions are 2” x 2” x 0.125”, and the hydraulic cylinders are attached to the flange with screws. One leg
Chapter 10: North Carolina State University 117
consists of a hydraulic cylinder attached to the 2”
aluminum flange, which in turn is attached to the
MDF.
Monarch Hydraulics, Inc manufactures the hydraulic
cylinder unit. The hydraulic unit consists of four hydraulic cylinders, tubing, and the pump house. The
cylinders are attached to the pump house by the fluidfilled tubing. The tubing is held in place flush with
the under section of the tabletop via ring slip ties
screwed to the table. The pump housing is attached
to the MDF on the underside of the table using a 0.25”
aluminum plate, which has counter sunk screws.
The white, non-toxic, hydraulic fluid is pumped
through the pump house, through the fluid lines, and
into the cylinders when the manual lever is turned
clockwise. After the fluid is pumped to the bottom of
the cylinder, it causes an in crease in pressure that
lifts the tabletop off the ground against its own
weight. To lower the table, the manual lever must be
Figure 10.1. Evaluation and Treatment Table.
turned in the counter clockwise direction. This releases the pressure, allows the fluid to return to the
housing, and, in turn, allows the tabletop to lower to
any desired position. Casters are attached to the bottom of the cylinders so the table can be moved from
one place to another within the therapy room. Two of
the casters have braking mechanisms for safety.
The final cost of the table was approximately $1500.
BICYCLE CART FOR A CHILD
Designers: Laura Cruse, Jason Latta, Chad Myers
Client Coordinator: Beth Buch
Tammy Lynn Center for Developmental Disabilities
Supervising Professors: Dr. Susan M. Blanchard, Dr. Roger P. Rohrbach
North Carolina State University
Raleigh, NC 27695-7625
INTRODUCTION
A bicycle cart was designed for a child with developmental disabilities (Figure 10.2).
SUMMARY OF IMPACT
This project was designed for a family that enjoys active recreation. The family has been limited in what
they can do together because of a daughter’s physical
disabilities. She has limited control of the muscles in
her neck and trunk region. She has movement in her
arms and legs about but cannot protect herself from
falling, so she must be strapped into any seat she
uses. The cart enables the whole family to go on bicycle outings together.
The bicycle cart was designed for a specific child but
could be used for other children who have similar
needs. The main design requirements for the cart
were: 1) The frame should be sturdy and strong
enough to support the child and additional supplies,
such as medical equipment or food for a picnic; 2) The
frame should be wide enough to prevent it from tipping over; 3) The seat should provide support for the
child; 4) The seat should prevent the child from sliding out; 5) The seat should support feet and legs so
that the child's legs do not dangle; 6) The seat should
be adjustable as well as comfortable; 7) The clamp
that attaches the carrier to the frame must be easy to
attach and detach; and 8) The cart must fold quickly
and easily to a size for easy transport.
The bicycle cart has four main components: the
wheels, the frame, the side rails, and the attachment
arm. The frame is square with rounded corners and
lower supports. The wheels attach to the frame by
way of a quick release mechanism that slides on and
off of the aluminum wheel brackets located under the
frame. The frame is made of 6061 USA grade aluminum tubing connected by welding pieces of solid
aluminum round stock inside the tubing connection
points. The side rails are attached near the corners of
the frame. These rails are attached with bolts on plastic folding mechanisms. A horizontal roll bar is attached at the top of the side rails by bolts and has a
plastic swivel for folding. On the front left underside
of the cart is the attachment arm that clamps onto the
bicycle frame near the wheel. The arm is attached to
the cart by a pin that allows the arm to swing under
the frame for transport and storage. The mechanism
that attaches the arm to the bicycle is made of a ball
joint and clamping device.
The frame is covered by eight-ounce coated cordura
nylon that is sewn and bolted on. The seat is also
made of eight-ounce coated cordura nylon, with nylon webbing for support and attachment. The webbing runs under the bottom portion of the seat and attaches to the cross members of the side rails. The
webbing sewn to the roll bar also supports the back of
the seat. On the seat is a pommel style harness made
of the same webbing used in the seat. It is attached
with a plastic backpack clamp.
The cart was analyzed for stress and deflection using
simple beam point load calculations. The appropriate equations were selected from the Midwest Plan
Service Structures and Environment Handbook, 11th
ed. A safety factor of 1.43 was used. This safety factor had a corresponding probability of failure of 1%.
A yield strength of 37,000 psi was selected from the
tables in the same handbook. The maximum allowable stress was calculated to be 25,874.13 psi. The
cart was originally designed to withstand a maximum load of 100 lbs. However, it was found that the
cart exceeded the maximum allowable stress at loads
between 225 to 250 lb with deflections in the range of
Chapter 10: North Carolina State University 119
0.15 to 0.30 inches. The only deflection that exceeded
this range occurred in the upper batten, where a deflection of 0.81 inches was noted at a 175-lb load. The
upper batten was designed to provide lateral stability
for the side rails and was not intended to endure
loads over 100 lb.
Figure 10.2. Bicycle Cart.
Tests of the cart were performed with a 215-lb man.
The cart showed little deformation and handled well
even in rough terrain.
The final cost of this bicycle cart was approximately
$1000.
CHAPTER 11
NORTH DAKOTA STATE UNIVERSITY
Department of Electrical Engineering
Fargo, North Dakota 58105
Daniel L. Ewert (701) 231-8049
[email protected]
Jacob S. Glower (701) 231-8068
[email protected]
Val Tareski (701)-231-7615
[email protected]
121
VOICE RECOGNITION CLOCK
Project Engineers: David Hagan, Jamie Metzger, Kim Cuong Tran
Client Coordinator: Marla Wagonman, Centennial Elementary School, Fargo, ND
Supervising Professors: Dr. Daniel Ewert & Dr. Jacob Glower
North Dakota State University Fargo, North Dakota 58105
INTRODUCTION
As a part of a class project, a group of fourth grade
students attempted to envision what common devices
used today would look like twenty years from now.
One of these ideas was an alarm clock that tells the
time in response to a spoken request. The students
realized that such a device could be built today, and
further, this device would be useful to a person with
visual impairment or blindness. The teacher for this
class approached the project engineers and asked if
such a device could be built for the fourth grade students.
For such a device to be useful to a person with visual
impairment or blindness, specifications provided by
the students stated that the alarm clock be portable,
have a display that is easy to read (for persons who
are not blind but have visual impairment), have a
voice output to tell time when activated, and be activated through voice input.
SUMMARY OF IMPACT:
The finished clock was delivered to the students. In a
class ceremony, the students presented the talking
alarm clock to a student with blindness, who continues to use the device. The collaboration between the
elementary students and the project engineers resulted in a device that allows a person with visual
impairment or blindness to more easily tell the time, a
group of elementary students observing and becoming involved with the design process, and the sharing of a joy for engineering among the young students
and the project engineers.
The design of the Voice Recognition Clock centered
around three components: the voice input, the talking
alarm clock, and interface circuitry.
Figure 11.1. Students During Construction. (From an
Article in the Fargo Forum).
A HM2007 Voice Recognition Processor Demo Board
was selected for the voice input. This board is an
evaluation board for the Hualon HM2007 Voice Recognition Chip, capable of recording and recognizing
up to 16 different words or phrases.
The evaluation board comes fully assembled and
ready to use. To program a word or phrase, the operator types the word that he/she is going to say
(from 00 to 16) on a keypad, followed by a pound key,
and speaks into a microphone. When that word is
spoken again and recognized, the number (from 00 to
16) is displayed on a two-digit LED display and sent
to an eight-pin BCD output port.
Arbitrarily, word #08 was selected as the word that
will trigger the talking alarm clock. The buffer circuitry looks for the spoken word #08. A flash of an
LED on the evaluation board signifies that a word
was detected, and then the number 08 appears on the
LED display. Once detected, a one-shot closes an
electronic switch.
A Radio Shack Alarm Clock Radio (Cat. No. 63-912)
was used for the talking alarm clock. This alarm
Chapter 11: North Dakota State University 123
clock has a large 1" LED display and a speech chip
built in. When the operator presses a "Voice" button,
a momentary switch is closed and the alarm clock
"speaks" the present time. By shorting this switch
with the output of the buffer circuitry, the operator is
able to trigger the alarm clock by speaking whatever
phrase was previously recorded in position #08 in
the voice recognition board.
tion board and the speaker are on the top of the clock.
In addition, three buttons for setting the time, the
alarm, and resetting the voice recognition board are
placed.
The total cost was approximately $250.
The final design of the clock is housed in a 14cm x
19cm x 16cm Plexiglas enclosure and weighs about
1kg. The keypad for programming the voice recogni-
+5
Clock Button
LED Signal
(from VRB)
+5
1k
3.9k
LM 311
gnd
Vcc
TR
DIS
1k
7474
7404
S
CLK
Q
D
R
R
4th Bit
from VRB
(Word #08
recognixed
Q
10k
22uF
7404
Figure 11.2. Buffer Circuitry Between Voice Recognition Board and Talking Alarm Clock.
ALARM CLOCK FOR INDIVIDUALS WITH
HEARING IMPAIRMENT
Project Engineers: Pierre Bartoo, John Hagan, Anishman Tripathy, Brian Volk
Supervising Professors: Dr. Daniel Ewert and Dr. Jacob Glower
INTRODUCTION
Individuals with hearing impairment have a difficult
time finding an alarm clock that is capable of reliably
awakening them in the morning. An alarm clock that
shakes the bed of the owner was designed to provide
a reliable and pleasant way for individuals with
hearing impairment to awaken.
The Alarm Clock for the Individuals with Hearing
Impairment consists of four main components: an
alarm clock, a radio transmitter, a radio receiver, and
an “alarm.”
The clock module is contained on a pre-made board
containing the clock chip, display LEDs, and the circuitry, requiring only a 9V power supply to operate.
A 9V wall transformer provides power to the clock
module as well as to the speaker and radio transmitter.
When the alarm goes off, a +5V signal is sent to the
radio transmitter and the speaker. The transmitter
uses AM modulation on top of a 1 MHz carrier to
transmit the alarm to the receiver.
Two oscillators are used in the transmitter. One is
used for the carrier signal and the other is used for the
modulated "ON" signal. A 20MHz programmable
chip oscillator produces the modulated signal. Its frequency can be divided 256 times to 78.125kHz. A 12stage binary ripple counter then divides this signal to
produce a 1.2kHz signal. This signal is used to
modulate a 1 MHz carrier using the following circuit.
By using a 1 MHz carrier modulated at 1.2kHz, a
portable AM radio was used to test the functionality
of the transmitter and to estimate the range. A twometer range was easily obtained with little or no use
of antenna. For a reliable signal, a six-meter range
would be preferable. To obtain a greater range and to
remove the harmonics from the 1 MHz square wave
used for the carrier, an amplifier and LC tank were
added to the final stage of the transmitter.
A seven-transistor superheterodyne receiver was
used for the receiver of the modified alarm clock. This
radio receiver came in a kit and receives radio frequencies from 540kHz to 1600kHz - the standard AM
band. For this project, the receiver was tuned to 1
MHz.
The output of the receiver (tuned at 1 MHz) detects
whether a 1.2 kHz signal is detected by the receiver or
not. If a 1.2 kHz signal is detected on the 1 MHz carrier, a 2n222 transistor switch turns on a pair of motors. These motors have off-balance loads on their
shafts, creating the "shaking" of the receiver box.
The final design consists of two units: the radio/transmitter and the receiver/shaker. The radio/transmitter is placed in a 20cm x 12cm x 5xm
Plexiglas enclosure. This includes a 2cm LED display for the time, buttons for setting the time and
alarm, and a power jack for the 9V wall transformer.
The receiver/shaker is placed in a 30cm x 10cm x 5cm
Plexiglas enclosure and contains room for the motors,
the receiver, and several batteries.
Field tests found that the receiver reliably detected the
alarm at ranges of 3 meters without any external an-
9:00 AM
1MHz
Radio
Transmitter
Alarm
1MHz
Receiver
Clock Module
Figure 11.3. Block Diagram for the Device.
Off-Balance
DC Motor
tennas on the transmitter.
The total cost of the project was $182.
Mixer
1.8k
LC Tank
1k
5.1k
LM 741
Power Amplifier
5.1k
CLC 460
5.1k
1.2 kHz
CLC 460
5.1k
18k
5.5k
470pF
2.2k
54uH
DC Offset Adjust
7.5k
1MHz Carrier
LM 741
+5
20k
5.6k
Figure 11.4. Circuit Diagram.
+9
68
Motor
with
Off-Balance
Load
Signal from
AM Radio's Speaker
2N222
100
560
7.5k
0.1uF
75k
CAMERA FOR INDIVIDUALS WITH VISUAL
IMPAIRMENT OR BLINDNESS
Project Engineers: Andy Freemeyer, Janna Harris, Tracey Tschepen, Stacy Barron
Supervising Professor: Dr. Jacob Glower
INTRODUCTION:
While a person with visual impairment may not be
able to "see" with his/her eyes, he/she can still obtain
information through the sense of touch. The goal of
this project was to design a device that converts light
intensity to a physical output, allowing the user to
"feel" the image rather than see it.
Handheld Unit
Photovoltaic
Light Sensors
Image
SUMMARY OF IMPACT:
The camera allows the light intensity of an object to be
sensed by feeling the height of solenoids. Unfortunately, several difficulties were observed with the design. First, the solenoids tend to chatter. This may be
due to electromagnetic compatibility problems,
ground loops in the design, or an exceedingly high
gain in the buffer. Second, the solenoids do not provide a firm surface. Weak springs were required so
that the current demand of the solenoids was not excessive. Weak springs, however, result in pixels that
are too compliant when touched. Third, even with
light springs this design required too much power.
Before this design is expanded to a larger grid size, a
better actuator must be incorporated.
The light sensor consisted of a 5mm photovoltaic cell
mounted in a handheld unit. Each sensor was placed
in tubes 2 cm long to provide a 30-degree field of view
for each sensor. Five of these sensors were placed in
the handheld unit, as shown in Figure 11.7, allowing
Figure 11.7. Sensors.
the camera to observe a 30-degree x 90-degree region.
To allow the microcontroller to read the light level
from the light sensors, a buffer circuit is used to amplify the voltage produced from the sensors to a 0-5V
signal. Two AD 626 instrumentation amplifiers provide a gain of 100 for the sensor and remove any
common-mode noise. A 0.47uF capacitor provides a
low-pass filter with a corner at approximately 1 Hz to
prevent aliasing at the A/D converter. A diode is
then used to reduce the sensitivity of the sensor at
high light levels.
For this device, the 6811 microcontroller acts as a fivechannel voltage-to-pulse width modulation converter.
The 0-5V signal from the buffer is read into the 6811
from Port E, an 8-bit A/D converter. Using real time
interrupts, these inputs are read every 32.77ms. Each
+5
8
+
8
6
1k
+
Light Sensor
Buffer
6811
Microcontroller
5
AD 626
Actuator
-
Photovoltaic
Cell
1
-
2
6
5
AD 626
3
1
0.47uF
Ge Diode
Power
Figure 11.6. Block Diagram of the Device.
+
Figure 11.8. Buffer Circuit.
-
2
3
A/
time they are read, the value read from the A/D is
copied to a buffer (Figure 11.8).
Height = Light Intensity
Five pulse-modulated signals proportional to the
voltage read from the A/D converters are generated
by the 6811 through the real time clock. Every timer
overflow (time=00) causes an interrupt that sets the
outputs from Port B high (the start of the PWM signal). When the on-board timer exceeds the value in
the buffer for a light sensor, the appropriate bit on
Port B is cleared. This creates a 0-5V PWM signal
with a duty cycle nearly 0% for a dark room and
nearly 100% when the sensor is pointed at a white object in the room.
The actuators chosen for this project are five STA pull
type solenoids from Lennex Corporation. These solenoids require 24V to operate and provide a pull
strength of approximately 0.3N. The iron shafts of
these solenoids are connected by a spring to a rod
above the solenoids. When no current is applied, the
rod is fully extended. The 6811 can then control the
height of these solenoids by adjusting the voltage applied to the solenoid.
Top of Enclosure
Spring
Pull-Type
Solenoid
+24V
0% to 100%
PWM Signal
Figure 11.9. Solenoid.
+24V
A 2n222 transistor serves as a power amplifier for the
6811 to drive the solenoid, as shown in Figure 11.9.
Solenoid
The cost was $502.
0-5V PWM
Signal from
the 6811
2N222
100
Figure 11.10. Another Circuit for the Device.
EXERCISE ENHANCER
Project Engineers: Jamie Hauser, Kasey Morlock, Jeremy Mattson, Don McAdoo
Client Coordinator: Jon Hinrichs, Hawley High School, Mawley, MN
INTRODUCTION
Exercise and conditioning are important for maintaining one's health. Exercise strengthens muscles,
improves coordination, and may even improve one's
mental state. Exercise is especially important for
someone who is recovering from an accident, or for
elementary school students with limited coordination.
Unfortunately, while exercise is important, exercises
are often inconvenient, requiring a physical therapist
to ”encourage” and supervise, and expensive, as
such programs are often not reimbursable by insurance.
In addition, exercise programs may require
individual attention - something a K-12 instructor is
not able to provide when teaching a large class.
A device that is inexpensive, portable, computer controlled, and capable of monitoring one's exercises
automatically, is a tool that could eliminate common
concerns about exercise programs. Such a device
would enable teachers to provide individual exercise
plans for students with limited coordination, allow
the students to work on their own, and to monitor
their activity without taking time away from other
students.
One type of exercise commonly used for conditioning
and rehabilitation exercise requires the patient to hop
back and forth as fast as he/she can for a set amount
of time. Numbers are often painted on the floor, as
shown in Figure 11.11, to facilitate the activity. A
physical therapist or teacher then counts how many
times the patient can do several different patterns
(such as hopping from square 4 to 5 and back, 4 to 2
to 5 and repeat, etc.).
In this project, an instrumented floor connected to a
PC was built. Design criteria were that the floor allow
the therapist to prescribe the pattern to follow, allow
1
2
3
Computer
4
5
6
7
8
9
Parallel Port
Figure 11.11. Grid.
the therapist to determine the time of the test, have the
total number of successful repetitions automatically
counted and recorded on the PC, be portable, and be
inexpensive.
SUMMARY OF IMPACT
First, the Exercise Enhancer may allow instructors to
better monitor the progress of students who are recovering from an injury or have limited coordination.
Second, the ability to better monitor the progress of
students allows instructors to accurately assess the
efficacy of different exercises.
Third, the Exercise Enhancer is completely automated, so instructors may be able to work with more
students at one time. The computer conducts tedious
activities such as counting and recording the number
of repetitions for each exercise.
This device was delivered to a high school for evaluation. Future improvements will make this device usable by any physical therapist or teacher.
The foot speed timer is a grid of nine squares that is
set up on the floor. For this design, a 3.2m x 3.2m
square made of plywood was used for strength and
cost effectiveness.
The total cost for this device was $178.
Square Student is Standing On
Data on Parallel Port
None
010101
1
100101
2
001101
The nine switches in the floor panel are connected to
the parallel port of a PC along with pull-up resistors
as shown in Figure 11.12.
3
000111
4
110001
With this setup, the parallel port can be read using
C++ for DOS. The readings for the student standing
on each panel are summarized in Table 11.1. Note
that by using the wiring shown in the previous figure,
three pins should read high and three should read
low at all times. This provides a error correction and
allows the software to detect when the parallel port
cable has not been connected to the platform.
5
011001
6
010011
7
110100
8
011100
9
010101
Each of the nine panels is made out of a separate
35cm square piece of plywood. Four doorstops are
placed under each panel, raising them when no
weight is applied. When a student stands on a panel,
the doorstop compresses and a switch underneath
the panel closes. In this way, a 3x3 keypad is created,
allowing the in structor to monitor which square (if
any) the student is standing on.
Software to monitor the parallel port and detect these
sequences was written in C++ for DOS. This software
allows the operator to monitor the number of times
the student completes an exercise as well as the time
it takes to go between squares to 1/60th of a second.
Pins 2/3/4/5/6/7
Table 11.1: Parallel Port Readings According to Panel.
+5
Parallel Port
Pin 2
+5
+5
1
Pin 3
2
3
Pin 4
+5
Pin 5
+5
4
5
6
7
8
9
Pin 6
+5
Pin 7
All resistors 1k
Pin 25 (gnd)
FORCE MEASUREMENT FOR PROSTHETICS
Project Engineers: Scott Wandler, Randy Kahlstorf, Dan Lang, Bryan Smith
Client Coordinator: Lisa Miller, St. Alexius Medical Center, Bismarck, ND
INTRODUCTION:
Physical therapists at a medical center requested a
device to provide balance feedback to patients who
use prosthetic legs. The device was to measure the
weight a patient applies to his/her prosthetic limb,
and display this weight to the patient.
It is hoped that, with biofeedback, patients will be
able to "feel" how much weight they are applying to a
prosthetic limb. This in turn may help accelerate the
process of learning to walk with the prosthesis.
SUMMARY OF IMPACT
This device was delivered to physical therapists at a
medical center. Based upon their experience using
this device, further refinements will be necessary.
Since prosthetic limbs are relatively expensive and
custom designed for each patient, it was not considered feasible to place a force sensor on the limb itself.
Instead, a device was sought that can be added to a
shoe.
The Force Measurement for Prosthetics Device consists of two main components: a force sensor and a
hand-held display. The force sensor selected was a
pair of Air Nike running shoes. These shoes have an
air pocket along the length of their soles. As the patient places more weight on the shoe, the pressure in
the air pocket increases. (Note: both Air Pippen basketball shoes and Air Nike running shoes were used
in this project. Air Pippen basketball shoes do not
experience a significant change in air pressure when
one stands in the shoe - almost as if the air pocket
were decorative. The Air Nike running shoes proved
to be much softer and more sensitive.)
To measure this air pressure, a hypodermic needle is
inserted into the air pocket of the running shoe. This
needle is glued to a piece of surgical tubing 1.5m long
with a 100psi pressure sensor (Digikey part NPC-410)
glued to the other end, creating a disposable needle/
pressure sensor unit. A second surgical needle is
placed on a basketball pump for reinflating the shoes
prior to use.
The output of the pressure sensor is amplified with a
gain of 100 by an AMP04 instrumentation amplifier.
This signal then drives a 10 segment LED bar display.
The LED bar display is controlled by a TSM-3914
chip. This chip has two reference resistances (Rlow
and Rhigh) and Signal In voltage as its inputs. Rlow
determines the voltage at which no LEDs are turned
on. Rhigh determines the voltage where all ten LEDs
are turned on. Intermediate voltages then activate a
proportional number of lights.
Two potentiometers allow the operator to set the two
control voltages. When the operator is not applying
any weight to the show, the low set point is adjusted
until no LEDs are on. When the operator places all of
his/her weight on the shoe, the high set point is adjusted until all LEDs are lit. From that point on, the
LED display will show the approximate weight the
patient is applying to that foot - from 0% to 100% of
their weight.
The resulting design for this device costs $198 - 70%
of which comes from the running shoes. By using offthe-shelf running shoes, this device should be usable
for any patient with any shoe size. Further, since the
air pocket can be reinflated (it leaks, however the
pressure will remain for a day or two - long enough
for a walk), the same pair of shoes can be used for a
several patients. Finally, since the bar graph display
can be calibrated for each user, this device should be
usable for both children and adults.
+9V
10uF
Vled
NC
62
gnd
V+
1.2k
Rlow
25k
Signal In
Rhigh
25k
-9V
Ref Out
5.1k
1.5k
Ref Adjust
Mode
1k
gnd
+5V
IN-
AMP04
+5
Out+
NPC-410
IN+
Out-
Figure 11.13. Circuit Diagram for the Device.
gnd
gnd
TMS-3914
LED Bar Graph
VOICE SPECTRUM ANALYSIS
Project Engineers: Cheryl Bernstetter, Tanya Hylden, Scott Swanson
Client Coordinator: Louise Dignan, Human Communications Associates, Fargo, ND
INTRODUCTION
Learning to speak can be a difficult process. Even the
smallest of words must be heard repeatedly over time
before a plausible resemblance of the word is uttered.
This process of auditory recognition is the primary
method of learning to speak.
For individuals with hearing impairment, learning to
speak may seem impossible. Limited auditory ability
makes learning to speak difficult. Sign language and
obtaining feedback from a hearing person may be the
only means of communication for individuals with
hearing impairment. Many of the electronic speech
labs on the market can be very costly, cumbersome,
and difficult to operate. In addition, learning to use
these devices requires person-to-person contact,
which can be a drain on a speech-language pathologist's time and resources.
With these obstacles in mind, the project engineers set
out to design a method for helping individuals with
hearing impairment learn to speak and pronounce
words accurately.
SUMMARY OF IMPACT
The portable PC and software will be tested and
monitored by a professional from a communications
firm starting in the summer of 1998. The feedback obtained through the initial use of the device will eventually lead other design groups to improve the device
to make it usable by any speech-language pathologist
and/or client.
Design Approach:
One of the desired outcomes of this project was to use
the clients' visual ability to help them learn to speak.
Linguistic sounds can be broken up into distinct
components called phonemes. Phonemes are com-
bined to form words. Phonemes are audibly distinct
due to their formants, which are unique groups of
waveforms of varying frequency and intensity.
Spectrograms display these groupings, providing a
visual representation of speech graph indicating time,
frequency and intensity.
This display would
distinctly show the groupings of the waveforms, their
frequencies, and their intensities, thereby giving a
display unique to each word.
For example, the word “speaking” is displayed in a
spectrogram on the following page. The horizontal
axis displays time, starting with the /s/ sound on the
left and ending with the /ng/ sound on the right.
The vertical axis displays frequencies, starting from
DC on the bottom to 10kHz on the top. Intensity is
displayed showing the strongest sounds in bright
colors and the weakest sounds in dark colors.
The /s/ sound contains a large amount of white
noise and is seen by the first 20% of the sound. The
/p/ is a sharp spike just after the quiet dark zone, one
third of the way from the beginning of the word. The
long /e/sound shows a clean signal with a strong
overtone. /k/ is a sharp noise 70% of the way
through the word. A soft /i/ followed by a /ng/
sound completes the word.
A desired outcome of this project is portability and
user friendliness. If the software interface is written
to be user-friendly, this teaching aid could be used
independently of the speech-language pathologist. If
it is designed to be portable, the client could take the
device home and out into diverse environments, increasing the amount of practice time available to the
client.
Cost is the greatest concern for this project. Most
other electronic speech tools are very expensive, costing up to $20,000. A lower-priced tool would enable
more speech pathologists to acquire this technology
for their labs, increasing the resources for their clients.
In order to meet the desired outcomes, a laptop PC
was selected for this project. These computers meet
the requirement for portability, cost less than $2,000,
have voice inputs built in, and have graphical displays as required for this project. Further, by developing software for a laptop PC, anyone who owns a PC
will be able to use the software free of charge.
Functional Description
Software routines were written for the PC using
MATLAB.
First, the target signal must be chosen. This target defines the "correct" pronunciation of the word and
serves as a target the patient is trying to match. Two
options exist here: either a previously recorded .WAV
file can be used as the target signal or a new .WAV
file can be created. This flexibility allows the patient
to use the device on his/her own time independent of
the speech-language pathologist by using previously
recorded files. The speech-language pathologist can
also record new words for his or her clients as progress is made.
Figure 11.14. Spectrogram of the Word "Speaking."
Next, once a target signal is selected, the spectrogram
of the target signal is displayed on the top half of the
screen using several modified MATLAB routines.
Once displayed, the operator is prompted to try to
match the word. A .WAV file is created, recording
whatever the operator says. This file is then converted to a spectrogram and displayed on the lower
half of the screen.
At this point the similarity or difference between the
target and the attempt should be apparent.
If the operator wishes to try again, he/she may go
back to the sound recorder, create a new .WAV file,
and display the new attempt.
The cost for this project was approximately $2,500 due to the requirement of a portable PC for the project
and compilers for the design group. Once the software is finalized and compiled, the cost to the user
should be nothing. If the user has a PC with Windows 95 and a microphone, he/she must simply install the software.
CHAPTER 12
NORTHERN ILLINOIS UNIVERSITY
DeKalb, IL 60115
Mansour Tahernezhadi (815)-753-8568
Xuan Kong (815)-753-9942
135
VOICE PITCH ANALYZER
Designers: Kumiko Tsuda, Von Monmany Richard Kwarciany, Jeff Schonhoff
Client Coordinator: Kelly Hall, Department of Communicative Disorder
Supervising Professors: Dr. M. Tahernezhadi, and Dr. X. Kong
Northern Illinois University (NIU)
DeKalb, IL 60115
INTRODUCTION
A portable device for monitoring voice pitch was designed for patients with speech impairment. The portable device assists therapists and their patients in acquiring information on episodes of exceedingly high
pitch in everyday conversations.
SUMMARY OF IMPACT
Speaking with unusually high volume and/or high
pitch is believed to cause pathological conditions to
the vocal cords, such as vocal nodules. Chronic
hoarseness, breathiness, or complete loss of voice are
the most common symptoms of vocal nodules. Abnormal voice qualities such as these can be devastating to one's job performance and can have profound
psychological effects.
The primary method of treating patients with voice
disorders related to vocal abuse is the monitoring of
vocal habits. Typically, patients are asked to selfmonitor their speaking habits throughout the day and
make adjustments in their phonatory behaviors as
indicated. This treatment strategy is often unsuccessful (although some additional techniques, not described, here) have proven successful in many cases.
A continuous monitoring device may be more effective in objectively determining the individual's natural voice pattern and providing feedback (through
alerting sounds) when excessive high pitch or high
intensity is detected. Whenever the normal pitch
range is exceeded, the portable unit produces an audible tone alerting the patient. In addition, a total
daily count is registered to further assist the clinician
in monitoring the patient’s progress towards recovery. The portable speech analyzer meets the needs of
many clients. The unit will ideally lead to fewer office
visits and in turn to a reduction in healthcare costs
for the patient.
TECHNICAL DISCRIPTION
The portable device is battery operated and can be
worn around the waist. Signal from either a throat
microphone or lapel microphone is sampled and amplified with an adjustable gain through the onboard
A/D converter. Upon acquiring the sampled speech
signal, digital signal processing algorithms coded in
TMS320C50 assembly language perform voice pitch
level calculations. The DSK board will generate a
beeping sound if the voice pitch exceeds a preset
threshold recommended by the clinician. The pattern
of the audible sound is programmable based on the
preference of the patient.
The main design requirements for this project were
that it be: 1) portable and as small as possible for the
patient to wear around the waist without any discomfort; and 2) microprocessor based for ease of entering
the patient-dependent parameters and for maintaining a log of episodes.
The design is carried out on the Texas Instruments
TMS320C50 digital signal processor (DSP) DSK
board. The fixed point TMS320C50 DSP provides 10
K of on chip RAM with an instruction cycle of 50
nsec. The DSK board comes with the Texas Instruments TLC32040C Analog Interface Circuit (AIC).
The AIC is a highly integrated component that combines the functions of a 14-bit A/D, a 14-bit D/A, input anti-aliasing filter, output reconstruction filter,
and a serial CPU interface. The AIC can be programmed for various sampling rates, anti-aliasing
frequencies, and input gains.
For the portable speech analyzer, the input speech
signal from the microphone pre-amplifier is sampled
at 8K Hz by the AIC. The algorithm for the portable
speech analyzer uses two buffers of size 240 points
(one frame). While one buffer is being filled, the other
is processed. Four buffer status flags are used to con-
Chapter 12: Northern Illinois University 137
trol processing. The RBUFSEL flag is set to controls
which of the two input buffers are currently being
filled. PBUFSEL controls which buffer is being processed. BUF1RDY and BUF2RDY indicate that the
corresponding buffer is full and ready to be processed.
The main processing loop continuously
checks for a full buffer. Upon finding a full buffer, the
subroutine for the power calculation is called. During the processing, the other buffer is filled by the interrupt service routine (ISR). In the power subroutine, the power associated with the 240 samples in the
buffer is calculated. The calculated power value is
then added to a running sum that calculates the averaged power of 10 consecutive frames. The averaged
power is then compared with a set threshold. If the
averaged power exceeds the threshold, then a warning tone is generated. If desired, the output warning
could also be realized in the form of a mechanical vibration. Data in the buffer are analyzed for the largest
sample in the first and last third of the buffer to determine a clipping value. Two-thirds of the smaller of
the two peak values is used to clip the data prior to
pitch estimation routine as to remove components
due to formant frequencies.
The Autocorrelation Method and Average Magnitude
Difference Function (AMDF) method are two methods
used for calculation of vocal pitch. Auto-correlation
is a technique used to emphasize the periodic peaks
and de-emphasize the non-periodic portions of a signal by taking the windowed sum of lagged products
of the signal. Auto-correlation shows a maximum at
a first non-zero lag equal to the phonatory pitch. The
AMDF method takes the absolute value of the windowed difference between lagged signal samples. The
non-zero lag with the deepest value of ∆MDF indicates the pitch period. The pitch information is averaged over several frames. If the averaged pitch value
exceeds a preset pitch threshold a warning sound or
a mechanical vibration is produced.
The size of the portable unit is 4 5/16 by 2 11/16 by 2
1/16 inches. The housing contains the DSK board,
the microphone preamplifier, the beeper unit, and the
batteries. The portable unit consumes three 9-volt alkaline batteries. The DSK board itself runs from two
9-volt batteries (+9 and –9 volts) and the microphone
preamplifier also requires a separate 9-volt supply.
The current consumption during the loading of code
from PC to the DSK is 240 mA with a minimum re-
Figure 12.1. Portable Speech Analyzer Internal
View.
quired voltage of 6.00 volts. During processing, the
current consumption drops to 100 mA with a minimum required voltage of 4 volts. In order to save on
battery life, in the absence of any input voice signal,
the processor is put into the idle mode (via software)
where the current consumption can be further
dropped to 50 mA. The overall continuous running
time for the portable unit is approximately 3 hours.
A three-digit display can also be incorporated to the
design to display the number of times excessive pitch
or high intensity occurred. A programmer BCD
counter with asynchronous RESET (74HC160) is
used. The BCD output is directly fed to the BCD-toSeven
Segment
latch/decoder/display driver
(74HC4511). A common cathode 7 segment LED display is directly connected to 74HC4511. This arrangement is identical for all the three digits. However, the ripple-carryout output of the counter driving
the least significant digit must be given as the clock
input to the next counter. The RESET and LOAD pins
of the counters are tied to the supply.
The device was tested for detecting various levels of
high pitch or voice signals, and in each case the device was successful.
The final cost of the project is approximately $200.
A DSP-BASED WIRELESS INFANT MONITORING
DEVICE FOR INDIVIDUALS WITH HEARING
IMPAIRMENT
Designers: Jeff Ciarlette and Greg Stringfellow
Supervising Professors: Drs. M. Tahernezhadi, X. Kong
Northern Illinois University (NIU)
DeKalb, IL 60115
INTRODUCTION
A portable wireless device was designed to enable an
individual with hearing impairment to monitor an infant by detecting when the infant is crying. The receiver of the device can be housed like a pager and, in
effect, page the individual with hearing impairment
each time the infant cries.
SUMMARY OF IMPACT
Persons with hearing impairment are often unable to
use intercom-type infant monitoring devices. Therefore, alternative devices are essential. This infantmonitoring device relies on a digital signal processor
to detect infant crying sounds. Once crying is detected, a paging device alerts the user by vibrating
and activating a light emitting diode. With such a
device, users may conveniently monitor an infant and
still complete other household activities. The wireless
DSP-based infant-cry-recognition system serves as a
cost effective and convenient device for enabling an
individual with hearing impairment to monitor an infant.
TECHNICAL DISCRIPTION
Digital signal processing and wireless transmission
are the two primary technologies employed in the development of this device. Digital signal processing is
used to recognize the sound of an infant crying.
Sound recognition is accomplished in real time
through the use of a digital signal processor (DSP).
The device utilizes the TMS320C50 DSK board, a lowcost DSP board equipped with 14-bit input/output
analog- to- digital (ADC) and digital-to-analog (DAC)
converters. The DSP receives a signal from a microphone located near the infant. Employing digital signal processing algorithms, the DSP determines if the
Microphone w/Preamp
DSP
Transmitter
PAGER
Receiver
Vibration
Device
Figure 12.2. Block Diagram of the Wireless Infant
Monitoring Device.
microphone signal has the same properties as those
of an infant crying. The DSP then sends a control
signal to a wireless transmitter. The transmitter
sends a digital code to a receiver using frequency shift
keying modulation technique. Upon detecting the
code, the receiver vibrates and activates a light emitting diode.
The design requirements for the wireless monitoring
device were that it: 1) be able to recognize infant crying sounds; and 2) consistently alert the caretaker of
infant crying via a wireless system.
The infant crying sound detection is carried out on
the Texas Instruments TMS320C50 digital signal
processor (DSP) DSK board. The input speech signal
from the microphone pre-amplifier is sampled at 8K
Hz by the AIC. One can assume that the environment
in which the infant-monitoring device operates will
be relatively quiet. Sounds such as doors opening and
closing and people moving past the device will
probably be the extent of the common noises in the
environment.
Speech recognition relies on the speaker to vocalize
clearly and at a reasonable volume. Since infants do
Chapter 12: Northern Illinois University 139
not make precise crying sounds at distinct volumes,
the methods used to identify the crying sound are
based on short-term energy and zero-crossing analysis. Short-term energy is the energy contained in a finite length of the signal. It is defined as the sum of
the squares of the samples in the 20 msec segment
sliding on a sample-by-sample basis. Once the shortterm energy exceeds a preset threshold, the algorithm
indicates that an infant crying sound may be present.
The threshold is chosen so that very quiet or distant
sounds will not cross the threshold.
To make use of short-term energy practical, the microphone preamplifier was designed with adjustable
gain. This gives the user some degree of freedom as to
how far the microphone can be placed from the infant
simply by increasing the gain with distance. The second part of recognition is based on zero-crossings.
Zero-crossings are the number of times the signal
crosses the zero axis. There was an obvious trend in
zero-crossing any time the infant started to cry. As a
result, it was determined that using zero-crossing in
conjunction with short-term energy could provide a
suitable method for determining if the sound was the
infant crying. The only concern was that other common sounds would also share these characteristics. It
was determined through real time testing that most
sounds such as talking in a normal tone and doors
closing were not recognized as the infant crying.
The firmware for this project consisted of a Texas Instruments TMS320C50 Digital Signal Processor
mounted on small evaluation board called a DSK
board. The DSK consists of the DSP, a power supply,
an analog interface, two RCA sockets for analog input
and output, and an RS232 connection to communi-
cate with a personal computer. The entire evaluation
kit also included a debugger, an assembler, an instruction manual, and sample programs that were
used to develop the DSP program. A Texas Instruments TMS320C50 digital signal processor was used.
It is operated at approximately 40 MHz and is only
capable of fixed-point operation. The arithmetic logic
unit (ALU), the accumulator, and its buffer are 32 bits.
The TMS320C50 has 2K x 16-bit on-chip ROM, 9K x
16 bit on-chip RAM, as well as 1056 x 16 bit on-chip
data RAM. It also contains 64K I/O ports and two serial ports for input and output.
The DSP was programmed to fill a buffer of samples
with a length of 20ms. Since the analog to digital converter was programmed to sample at 8000 Hertz, the
buffer contained 160 samples when filled. For each
subsequent input sample, the oldest sample in the
buffer is overwritten by the new input. Each time the
buffer is updated with a new sample, its short-term
energy is calculated. The energy is then compared to
the threshold number stored in memory. The threshold level of the signal was determined in the simulation. If the energy exceeds the threshold, the DSP calculates the zero-crossings in the buffer. The number
of zero-crossings found in the buffer is then compared
to two values specifying the valid range of infant crying zero crossing. These values were also found by
analyzing the simulation results. If the number of
zero-crossings falls between these two numbers, an
output signal is sent from the DSP to the transmitter.
The transmitter sends this signal, using frequency
shift keying modulation technique, to the receiver,
which activates the pager. The final cost of the project is approximately $300.
Figure 12.3. DSP-Based Wireless Infant Monitoring Device for Hearing-Impaired.
CHAPTER 13
STATE UNIVERSITY OF NEW YORK AT
BUFFALO
School of Engineering and Applied Sciences
Department of Mechanical and Aerospace Engineering
335 Jarvis Hall
Buffalo, New York 14260-4400
Joseph C. Mollendorf (716) 645-2593 x2319
[email protected]
141
OPHTHALMOLOGIST’S OPTICAL LENS HOLDER
FOR SLIT LAMP EYE EXAMS
Student Designer: David Leff
Supervising Professor: Joseph C. Mollendorf, Ph.D.
Mechanical and Aerospace Engineering Department
State University of New York at Buffalo, Buffalo, NY 14260-4400
INTRODUCTION
A slit lamp test allows an ophthalmologist to view the
cross-section of an eye. A doctor holds a circular lens
approximately the size of a quarter near the patient’s
eye. Next he or she looks through a slit lamp to view
a cross-section of the eyeball. The exam may be difficult to perform if the doctor does not have full dexterity and strength in his or her hands.
This device addresses the client’s need to perform the
slit lamp test. As a consequence of amyotrophic lateral sclerosis (ALS), the client has not been able to
administer this test because of his inability to fully extend his fingers. Also, his wrists are weak which decreases his ability to manipulate the lens.
The client is able to grip objects that are roughly the
same size and shape of a broom handle. The primary
goal of this project was to design and construct a device to maximize the doctor’s limited strength and
dexterity allowing him to perform the slit lamp exam.
Another goal was to make the device aesthetically
pleasing.
A lightweight device in which the lens could be inserted with a handle similar in size and shape of a
broom handle was constructed. The shape and
weight of the tool are designed for the ophthalmologist to hold the lens near the patient’s eye, while preventing the device from becoming obtrusive to the patient.
To increase the comfort of the device for the patient, a
nosepiece was added to avoid the nose (Figure 13.1).
A viewing port allows the patient to focus on a dis-
tant object through the bridge of the optical lens
holder.
SUMMARY OF IMPACT
The ophthalmologist with ALS uses the device to perform the slit lamp test. However, he continues to require assistance in lifting the eyelid of a patient. This
device allows him to perform a standard portion of an
eye exam and to maintain his professional ability.
To meet the criteria of a lightweight, durable and aesthetically pleasing device, a composite material of
foam and fiberglass was utilized. To address precision fit of the lens, a nylon insert was machined.
The device began as a foam cutout, the same size and
shape as the finished lens holder. Three layers of a
lightweight fiberglass (microglass) were glued to the
foam with epoxy resin and allowed to dry. The use of
fiberglass-coated foam gives the device a higher
weight-to-strength ratio than titanium. To further increase the compressive strength of the device, an epoxy/glass microsphere filler was applied to the surface and allowed to dry. The device was then sanded
and applied with a coat of primer to provide a neat
finish. To eliminate unwanted reflection during an
eye exam, the lens holder was painted a flat black.
An improvement for the design may include the addition of a device to lift the eyelid above the lens.
The total cost of materials and supplies was approximately $35.
Chapter 13: State University of New York at Buffalo 143
Figure 13.1. Lens Holder as Seen by User.
Figure 13.2. Top View of Lens Holder.
WHEELCHAIR STEP NEGOTIATOR
Student Designers: Yik Kan Leung, Matthias Kolodziejczyk
INTRODUCTION
C-channels also prevents the wheelchair from moving
The objective of this project was to design and build a
portable ramp to enable a person in a wheelchair to
safely climb one to three steps without a permanent
ramp. By allowing the user access to elevated areas,
the ramp decreases reliance on passers-by, thereby
increasing the user’s independence.
SUMMARY OF IMPACT
A major aspects of the ramp design is a braking feature, providing the wheelchair user time to move and
grasp the rear wheels after completing the action of
moving the chair forward. Additional features in clude its small storage size, tall guide rails, and several safety features.
The main design constraints for the ramp were its
weight and size. The length of the ramp is fixed, necessitating extension to a length of eight feet.
Aluminum was used because of its high strength-toweight ratio and low cost. To further reduce user
burden the conventional large track was divided into
two smaller tracks that may be deployed one at a time.
Each ramp is composed of three sections that telescope in and out of each other. When extended to the
maximum length, the 36-inch sections reach a total
length of eight feet forming an ascension angle (the
angle between ground level and the ramp) of 10.8°
when raised to a height of 18 inches. With the braking feature described below, the majority of users will
be able to use this ramp design to gain access to elevated areas.
Each section of the ramp is made up of two aluminum
C-channels and a base plate. The two C-channels are
welded onto the sides of the base plate. The Cchannels provide the necessary support and act as
guide rails for the user’s safety. The placement of the
Figure 13.3. Wheelchair Step Negotiator.
backwards. Since the front wheels must rotate 180
degrees for the wheelchair to change from moving
forward to backward, with a distance of 7 inches between the guide rails, the front wheels do not have
sufficient room to rotate the full 180 degrees required
for the change between forward and reverse movement. Instead the front wheels rotate approximately
60 degrees before being stopped by the guide rails
and thus are prevented from moving backward. This
braking effect stops the wheelchair from unintentionally rolling down the ramp and allows the user time
to grasp the rear wheels after moving forward.
The outer section is 3 5/8 inches high by 9 and 5/8
inches wide. The middle section is 3 and 5/16 inches
high by 9 and 5/8 inches wide, and the inner section
is 3 inches high by 9 inches wide. All three sections
When the inner section is fully protruded, a peg located on the inner section locks the inner ramp to the
middle ramp, thus locking both the inner and middle
section in place with a 6-inch overlap. This prevents
the inner section from sliding apart from the rest of
the ramp. The middle section also has a similar peg
to lock onto the outer ramp.
The ramp will not deflect or bend when supporting a
weight of 500 lbs or less, thereby enhancing the client’s sense of stability and safety.
The total cost of materials and supplies was about
$180.
BOOK RETRIEVER
Student Designers: Maya L. Easley, John Evan W. Gorski, Sanjeev Khurana
INTRODUCTION
Some individuals have difficulty using library facilities effectively due to limitations with reaching. Average library shelves ascend to approximately seven
feet. However, the reaching limitations of an individual using a wheelchair are between four and five feet.
The lower shelves are accessible, but additional assistance is required in retrieving books from beyond five
feet.
The presence of a book retrieval device within library
facilities may have a positive impact by increasing
accessibility for patrons with disabilities and other
individuals who have difficulty reaching books from
high shelves. Along with increasing accessibility, the
Book Retriever enhances independence for individuals with disabilities.
The Book Retriever incorporates features of reaching
devices currently on the market. However, such devices are generally designed to handle small objects,
such as pieces of paper or articles of clothing. Devices currently on the market do not possess the
strength and durability needed to grasp large, relatively heavy books. Therefore, a much sturdier device
was necessary.
SUMMARY OF IMPACT
The Book Retriever assists individuals in obtaining
books from shelves above their reach. It will allow libraries to be more accessible to patrons with disabilities.
The Book Retriever is composed of the following six
components: cable, arm, hook, and chute, and a bicycle brake lever with calipers. All parts except the calipers and cable are aluminum. Aluminum was
chosen as the main material due to its high strengthto-weight ratio.
Figure 13.4. Shelf Book Retriever.
The development of this device evolved through investigative processes of observation, simulation,
analysis, experimentation, and evaluation. When
reaching for or removing a book from a shelf, a person
hooks the book with a finger to pull the book from the
rest and then grasps the book. Thus, the optimal design closely simulates the hand and limb motion involved in book retrieval. For this reason, a hook and
jaw (caliper) system was used.
The brake handle, calipers, hook, and chute are
mounted on the arm. The arm is constructed of aluminum tubing with an outside diameter of 7/8” and
a length of 50 3/16”. The caliper is 4 ½” in length
and has a maximum span of 1 ¾”. The calipers have
a quick release mechanism allowing the operator to
reduce the span for grasping thinner books. To close
the calipers, a brake handle is squeezed, similarly to a
bicycle brake. A cable attached to the lever and the
calipers follows the motion of the lever and pulls the
calipers closed. The hook snags the top of the bookbinding and tilts the book forward enable the operator to grab the book with the calipers. Once this is
accomplished, the book is released into the chute
where a net is attached to catch the book. A spring
hinge attached to the chute allows the chute to be bent
back when pressed against the bookshelf. This eliminates interference of the chute while using the hook
and calipers. The weight of the Book Retriever is 2.5
lbs and the mechanical advantage is six.
The designers would like to thank the following people for their cooperation and efforts: Edward Herman
for his insight and previous knowledge of working
with the Americans with Disabilities ACT (ADA)
subcommittee in dealing with handicapped accessibility on campus, Professor Colin Drury in the Indus-
Figure 13.5. Calipers, Hook and Chute.
trial Engineering Department for his vast knowledge
of ergonomic design, and Kenneth Peebles and Roger
Teagarden for their help in converting the design
from paper to a working prototype.
$60.
PORTABLE LIFT FOR WHEELCHAIRS
Student Designers: James K. Adams and David Leff
INTRODUCTION
Height differentials are often difficult obstacles for
people in wheelchairs. Available devices to assist in
the negotiation of such obstacles are generally expensive and bulky. The main purpose of this project was
to design and construct a portable device to assist a
person in a wheelchair independently negotiate
height differentials of up to 18 inches. Such a device
will help persons in wheelchairs ascend curbs, transfer into and out of wheelchair transport vehicles, and
ascend other such height differences. A permanent
ramp, curb cut, or wheelchair conversion van would
not be needed.
SUMMARY OF IMPACT
An assistive device was successfully constructed to
safely lift the wheelchair to the expected height. It has
a compact, sleek design for increased comfort of the
operator. The lift rises simply by manual inflation
with an air pump. When deflated, the lift can easily
be stored in the trunk of a car or the back of a van.
The airlift is rated for a 300-pound load.
The appeal of the airlift is its weight (approximately
40 pounds) and storability (deflates to about 36” x
24” x 4”). The lift is constructed of one 19” x 19”
heat-sealed, reinforced, nylon/urethane bellow supplied by Gagne, Inc. The bellow weighs approximately two pounds. The bellow was manufactured
with pre-drilled bolt holes around the perimeter. On
the top and bottom of the bellow are 36” x 24” x ¾”
plywood plates. The plates are mounted on the bellow with three-quarter inch machine screws set into
an aluminum flange plate and rubber gasket. When
the bellow is inflated with a simple, double-action air
pump, the wheelchair is raised. The airflow can be
regulated by the quick disconnect valve.
used for stabilization. 1018 cold-rolled steel was
used for the bars and angles. The two bars on both
36” sides are pinned together at the center with
shoulder bolts. One McGill cam follower was used
on each bar to allow smooth motion along the track
on the angle iron. The track was welded using 7011
rod. Increased stability may be achieved by adding
crossbars to the two remaining sides.
Limiting horizontal movement during inflation was
important. Scissor-action metal crossbars were thus
While steel supplies exceptional strength and stability at a low price, it adds substantial weight. Substi-
Figure 13.6. Portable Lift in Down Position.
tuting high-strength plastic crossbars would substantially decrease the weight, but would increase manufacturing costs. High strength-to-weight, fiberglass
foam plates may be substituted for the wood, decreasing the weight as well. This would also significantly
increase the total cost of production. These advanced
modifications would decrease the total weight of the
lift by more than half.
$400.
Figure 13.7. Portable Lift in Raised Position.
ASSISTIVE GLOVE: A MECHANICAL
EXOSKELETON TO AUGMENT HAND STRENGTH
AND CONTROL
Student Designers: Sean Selover and Piotr Frey
INTRODUCTION
Some individuals cannot use their hands to perform
daily tasks. An assistive glove w a s developed to
augment hand strength. Ideally, the glove allows the
individual with a disability to sustain a tighter grip
on various objects.
The assistive glove is designed to aid people who suffer from muscle injuries or diseases of the nervous
system, such as myasthenia gravis or muscular dystrophy. These diseases may cause people to lose control in their hands. In such situations, people are unable to perform necessary tasks and must rely on assistance from others. The glove compensates for the
individual’s lack of motor control by replacing the
mechanisms necessary for flexion of the hand and
phalanges. The glove requires minimal use of the individual’s thumb for proper operation.
SUMMARY OF IMPACT
The use of the assistive glove returns some lost functions of the debilitated hand. While wearing the device, a person can pick up and hold objects from 0.5 to
about 4 inches in diameter. The glove can also be
used to carry larger objects (boxes or piles) where the
hand needs to be hooked. The glove demonstrates
mimicry of the components responsible for flexion of
the human hand.
One disadvantage of the glove is a loss of sensitivity,
resulting from the lack of contact between the object
surface and the palm and fingers. The greatest advantage is increased independence.
Figure 13.8. Assistive Glove.
The device consists of two components, a wrist brace
manufactured by DONJOY® and a flexible hand
piece attached to the brace. The user places his or her
hand on an object and, using the opposite hand, pulls
and fastens the wrist lever, causing the glove to wrap
around an object. The hand-piece is designed to
closely mimic the mechanics of the human hand. It
consists of three movable sections (with effective
length corresponding to the finger length) connected
to each other. This allows the links to bend together,
in the way that fingers of a hand wrap around an object while holding it.
$105.
Figure 13.9. Grabbing Mechanism Being Activated.
EMERGENCY VACUUM-PACKED NECK
SUPPORT
Student Designer: Tomasz R. Targosz
INTRODUCTION
The objective of this project was to design a neck support for emergency purposes. The neck support is for
temporary use only, up to two hours. Commercially
available neck supports do not provide the maximum
support possible.
The vacuum-packed coffee sold in grocery stores inspired key features of the design. The requirements
for the neck support were that it: be rigid when in use,
provide custom fit, permit production in large quantities, take up as little space as possible when in storage (preferably to be stored flat), and be inexpensive
to manufacture.
SUMMARY OF IMPACT
The vacuum-packed neck support is an excellent substitute for current neck supports. It provides a greater
amount of support while meeting the storage and cost
requirements.
To apply the neck support, one must wrap it around a
patient’s neck and engage the Velcro. The vacuum is
drawn using a manual vacuum pump. For final adjustment, the Velcro is disengaged, the fit of the neck
support is tightened, and the Velcro is re-engaged.
The final adjustment is necessary to reduce a gap between the neck support and the patient's neck, which
results from a decrease in volume as the particles interlock.
Rigidity was the most crucial requirement of the design. Drawing vacuum and interlocking the filler material particles with each other ensured rigidity.
Other filler materials were used in experiments (polylite gardening product and ground coffee grains.)
The advantage of polylite is its low cost, but the disadvantages outweighed that advantage. Polylite is a
Figure 13.10. Neck Support as Worn Evacuated.
brittle material. When pressure is applied, polylite
disintegrates into dust-like particles. The filler material must remain intact before and during use. The
advantage of ground coffee grains was their resistance to disintegration, provided they were well
ground. The coffee grains also interlock well with
each other. The disadvantage of coffee is its high cost.
Although the coffee is not the ideal solution, it demonstrates that the principle works. For commercial
purposes coffee can be substituted with materials
with similar properties, such as gravel.
When the pressure in the neck support equals the atmospheric pressure inside the neck support, the neck
support is flexible and molds to the contours of the
person’s features. As the vacuum is drawn, the filler
material particles interlock, creating a rigid structure
that remains in the previously assumed shape. The
neck support can be stored flat when not in use,
which allows for stacking (see Figure 13.11).
A triangular opening was incorporated to provide access to the patient’s throat for performing an emergency tracheotomy.
Figure 13.11. Neck Support in Storage Configuration.
A one-way valve was necessary to allow the air to be
evacuated and to prevent the air from entering the inside of the neck support when in use.
A Velcro strap was attached to both ends of the neck
support to allow it to be kept in a wrapped position
when in use.
$100.
SHOWERHEAD-ATTACHABLE SOAP AND
SHAMPOO DISPENSER
Student Designer: John A. Kyprios
INTRODUCTION
The showerhead-attachable soap and shampoo dispenser was designed for persons who experience difficulty showering due to a disabling condition, such
as arthritis or muscle weakness. This device assists
people in showering by automatically mixing cleansing material with water. This mixture results from
dripping the cleansing material (soap or shampoo)
into the oncoming flow of water from the showerhead.
SUMMARY OF IMPACT
The device uses no electrical power nor pumps and is
built with inexpensive parts. It works with the natural force of gravity. The device has the following three
major components: the material chambers, the hose
equipment, and the bracket.
The soap and shampoo are stored in the material
chambers. The chambers are connected to the hose
equipment, which, when all components are assembled and attached, is located directly over the showerhead. These two pieces comprise one unit adhered
with epoxy. Velcro links this unit to the bracket,
which is connected to the pipe leading to the showerhead.
An advantage of this device is that the plumbing of
the shower remains unchanged, resulting in easy detachment and attachment to the shower as needed.
The chambers containing the cleansing material are
made of Plexiglas. The pieces used were cut specifically to fit in baths where the clearance between the
shower pipe elbow and the ceiling is small. For the
shower where all testing was completed, the clear-
ance is less than 4 inches. This resulted in a compact
design. The various pieces were cut and connected
with silicon sealant glue to make a box 6 inches wide
and 3.5 inches high. The bottom rear of the box was
tilted upward to ensure a proper flow of material.
The front side of the box was tilted for the same reason. A Plexiglas piece was placed in the middle of
the box to separate it into two chambers for soap and
shampoo.
The hose equipment was connected with epoxy to
two 0.75-inch holes located in the outer bottom corners of the front piece of the box, one in each chamber.
The main piece of the hose equipment is the Y-valve.
This is the control valve for the cleansing material
flow. At the fully closed position, there is no flow of
material. This is the shutoff for the system. Attached
to the Y-valve are two plastic elbow tubes from where
the cleansing material flows and meets the water
coming out of the head. Where the plastic tubes connect to the Y-valve, a Plexiglas piece was inserted into
the Y-valve to separate the two flows of material to
prevent the mixture of soap and shampoo.
Finally, the bracket was made of Plexiglas pieces connected by silicon. The bracket has two hose clamps,
allowing a connection to the shower pipe elbow. The
bracket and chambers/hose equipment combination
are joined with Velcro for ease of detaching and refilling.
$25.
Figure 13.12. Showerhead-Attachable Dispenser.
AUTOMATED GARBAGE BAG SEALER
Student Designer: David Cheung
INTRODUCTION
A garbage bag sealer can be used for effortless, neat,
and odor-free disposal. Current garbage bag sealers
are mainly for diaper disposal. There is no similar
design for the household garbage bag on the market.
The problem with sealers currently available is their
limited size. A sealer makes a knot by twisting the
end of a continuous plastic bag when a diaper is inserted.
This device will benefit people who are physically
unable to tie a knot in a bag. The heat sealer provides
many advantages compared to the conventional ways
of disposing garbage. The heat sealer creates a complete seal across the bag, preventing leakage of odors.
There is no need to hold the bag to apply a twist-tie or
to make a knot.
SUMMARY OF IMPACT
New technology allows the use of heat to seal bags for
easy, sanitary, and odor-free disposal. An advantage
of the device is that only one hand is needed for operation. The device helps people who have difficulty
making a knot in a garbage bag.
This device is designed for household kitchen use.
With an attachable frame, it fits on most rectangular
garbage cans (13 gallon capacity) with dimensions of
10 ½” x 15”. The device is designed to use AC power
as it will be used in the kitchen. Unlike other knotmaking devices, there is no need to replace accessories (such as metal strips) because this device uses
only electricity.
The project is divided into two components, the frame
construction and the heat-sealing device. A handoperated impulse bag sealer from ABTEC, Inc. was
used to develop the garbage bag sealer.
The following are the parts of the heat sealer: heating
element, micro-switch, adjustable timer, and a highto-low transformer. When the sealer is activated, an
AC current flows through the transformer to reduce
the voltage from 120 volts to 20 volts and then
through to the heating element. The heating element
warms when current flows through it to perform the
sealing. When uniform pressure is applied, the bag is
sealed smoothly.
To provide variety, a timer can be set from 0.5 to 2
seconds for specific amounts of plastic thickness.
This enables people to buy different brands of garbage bags.
For safety concerns, the device is equipped with an
adjustable timer to prevent over-heating or fire hazards. The device deactivates when sealing is complete. A micro-switch is used to control the device.
The switch operates only when the gap between the
sealers is closed. Preventing children from placing
their fingers in the sealers is of paramount concern.
The device is operated at high-energy efficiency.
There is no warm-up time required, and it only uses
electricity within the set time.
The frame structure is built with lightweight aluminum, and the attachable frame is built with thin metal
sheet. Both are easily managed, as neither is heavy.
The inner frame is attached to the outer frame with
rivets. This allows people to remove the garbage bag
from the can once sealed.
The heating element is mounted inside the inner
frame. There is a bar that slides across the frame to
close the gap with the heating element. A string is
used to pull the bar across from the other side of the
frame. To decrease friction between the bar and the
frame, Teflon bushing is used as a bearing.
$125.
Figure 13.13. Automatic Garbage Bag Sealer.
ADJUSTABLE ANKLE SUPPORT TO RELIEVE
COMPRESSIVE FORCES
Student Designers: Adam S. Lurie, John E. Harder III and Jonathan K. Hammond
INTRODUCTION
Many people experience discomfort from compressive
forces on the ankle as a result of injury or disability.
Such injuries include a broken foot or ankle, a damaged Achilles’ tendon, bone spurs, ligament damage,
foot surgery, and arthritic ankles. Current ankle supports alleviate only plantar flexion and do not account for compressive forces.
This device transfers compressive forces from the ankle to the mid-tibial region of the shin, allowing people with the aforementioned injuries to walk without
pain. As the ankle heals, increased force may be applied for rehabilitative purposes as the user walks.
SUMMARY OF IMPACT
The adjustable ankle support assists people in both
the healing and rehabilitation phases of their recovery. Ankle braces used currently cannot be worn until the ankle is sufficiently healed because such braces
do not transfer compressive forces away from the ankle. Consequently, leg muscle atrophy is common.
The ability to vary the compressive forces on the ankle
allows this device to be utilized at an earlier stage of
healing. The use of this device will decrease the rehabilitation time and reduce the need for crutches.
The basic design began with a DONJOY High Tide
Walker, part number 11-0179-x-06136. This walker
consists of a washable leg sock and a plastic foot
piece with a molded rocker bottom for ease of walking. Riveted to the foot piece are two flap aluminum
bars. These bars follow the contours of the muscle.
There are three Velcro straps covering the length of
the aluminum bars. The sock and straps are adjustable with respect to the position of the bars. Three
other Velcro straps were attached to the foot piece and
were not position-adjustable. Two of these straps
were connected to the aluminum bars.
The first modification to the DONJOY brace required
cutting through the flap aluminum bars 1 ¼” from the
foot piece to remove the Velcro strap loops from the
bars. Two shock absorption devices were then attached to control the distance of heel travel.
Each device consists of an upper and a lower tube.
The lower tube has a bolt welded to the top and slides
inside the upper tube. The upper tube has a washer
welded to the top, through which the bolt on the
lower tube slides. A nut is attached to the bolt to secure the device. Between the tubes is a spring, which
controls the extent to which the shock absorber is
compressed. This shock absorber is attached to the
brace in the following manner: the larger tube is connected to the detached aluminum bar, and the smaller
tube is attached to the bar and the foot piece. Each
pocket consists of an air chamber and a valve stem.
This construction enables the heel to sink into the air
pouch, applying a force to the ankle as the springs are
compressed. This force is adjusted by changing the
air pressure in the pockets. Once the spring is fully
compressed, all additional force is directed to the
shin.
The design of the adjustable ankle support has been
tested, and the concept is successful. Additional investigation into air pocket design could further improve this device.
$125.
Figure 13.14. Adjustable Ankle Support.
ASSISTIVE CAR SEAT TO FACILITATE
ENTRY AND EXIT
Student Designers: Jim Mittag, Jason Gwin, Arthur Trombley III
INTRODUCTION
The objective of this project was to design and build
an assistive device to aid a person with a physical
disability in entering and exiting a motor vehicle.
Other devices fitting the overall description are often
large and require modification to the vehicle. The intent was to design a device that could be easily installed by the consumer with little or no modification
of the vehicle. The design was also to be lightweight
and as non-intrusive to the operator as possible. Low
cost and easy operation were important considerations.
SUMMARY OF IMPACT
The assistive device was successful in assisting a person in the entry and exit of a vehicle. The design
mounts on an existing seat with little or no interference and is easily operated. It provides consumers
access to an easy, reliable solution for a common
problem and thus has potential to improve quality of
life for many people.
The device facilitates entry to and exit from a vehicle
with minimal effort from the operator. It operates on a
sliding mechanism. The top portion contains a cushion on which the person sits. When the person
wishes to exit the vehicle, he/she swings his/her legs
out of the vehicle and slides the cushion out of the
vehicle.
The device consists of three frames. The first frame attaches to the car seat. Bolts are arranged on this
frame to allow for adjustability for different shapes
and styles of seats. The second frame contains the
shafts for the slider mechanisms. The third frame is
the seat cushion and contains the bearings.
The frames were made from 1 ½ inch steel angle. Steel
angle was used because of its strength and machinability.
The cushion was made from 1 ½ inch foam, covered
with canvas. This was bolted to the frame containing
the bearings.
The bearings used were Frelon-lined linear bearings.
This type of bearings was used because of cost and
performance. The Frelon bearings withstand water
and dust better than roller bearings. Before assembly,
the parts were painted flat black for aesthetic appeal.
When designing the device, the following key points
were considered:
•
Stability while the user enters and exits the
vehicle;
•
Adaptability to different styles of seats;
•
Lack of interference with the steering wheel,
seatbelts and door opening; and
•
Low cost.
The final design meets these criteria. The device does
not interfere with any of the existing parts in an
automobile. The device is stable in the open and
closed position. The total cost of materials and supplies was about $200.
Figure 13.15. Assistive Car Seat.
EASY PUMP FUELING DEVICE FOR SELFSERVICE GASOLINE DISPENSING
Student Designer: Christophe J. Day
INTRODUCTION
For many people with arthritis of the hand, or other
hand problems, pumping automotive gasoline may be
difficult or impossible. An assistive device can simplify this routine task by keeping the gas pump on as
the tank fills up.
The Easy Pump Fueling Device was designed to provide hands-free support at any basic gas pump. The
compact design allows for easy storage on a key
chain or in a glove box.
SUMMARY OF IMPACT
The focus of the device is to increase the independence of people with disabilities. The completed device meets all of the following design goals: simplicity, key chain size, ease of application and removal,
and no additional resistance.
Despite the disabling of locking mechanisms on most
gas pumps in New York State, this device allows people with disabilities to once again choose any gas
station instead of only those with locking mechanisms.
The device is primarily comprised of two components, the handle and the steepled arm.
The handle is made of a soft, rubbery thermoplastic
material. The material for the prototype was obtained
from a moldable athletic mouth guard. The geometry
of the handle is of great importance. To achieve important details such as a recess and protrusion, it was
necessary to make a clay mold in which the heated
thermoplastic could be set.
The steepled arm is also composed of a thermoplastic
material. The material in the steepled arm becomes
relatively rigid upon cooling. A key chain ring is
connected to the steepled arm, making the device failsafe by preventing the client from driving away without properly removing the device.
Coupling of the components was completed with a
simple ball-socket joint. The ball and socket are standard stock at local hobby shops. Twisting of the arm
at the joint is a negative factor and is minimized by
the use of a ball-socket joint. The purpose of the joint
is to allow a mostly two-dimensional swinging motion.
$15.
Figure 13.16. Easy Pump Fueling Device.
STOWABLE WHEELCHAIR UMBRELLA
Student Designers: Michael Jordon, Michael Miller, and John Walsh
INTRODUCTION
Most people in wheelchairs are not able to hold an
umbrella while outside in the rain. A person in a motorized wheelchair may not have the strength to hold
an umbrella, and a person in a manual wheelchair
needs both hands to move.
To keep persons in wheelchairs dry in the rain, a device to attach an umbrella to a wheelchair was devel-
sition should not interfere with the normal activities
of the user. The device must be completely detachable
from the chair. When open, the umbrella must be positioned properly.
SUMMARY OF IMPACT
This device is intended to improve the quality of life
for a person using a wheelchair. The user is kept dry
and comfortable.
The device is versatile for easy attachment to different
sizes of chairs. This feature increases the impact of
the device because more people will be able to use it.
While there are canopies to shield wheelchair users
from the elements, the canopies are large, obtrusivelooking, and difficult to store. This umbrella device is
more compact, easier to operate, and is stored in a
convenient location on the chair when not in use.
The device is easy to move. Retractable cords assist in
all movements of the device. Persons with little upper
body mobility and strength can use the umbrella.
Figure 13.17. Wheelchair Umbrella Stowed.
oped. The device is detachable and can be mounted
on many types of chairs from the rear handlebars.
Several design factors were important. The arm
bringing the umbrella from a stored position to an
open position must be easily movable. The stored po-
The device consists of two ¾” steel bars. One straight
bar is attached to the rear handlebars of the wheelchair with four hose clamps. The curved bar, known
as “the arm,” is attached to this straight bar, allowing
it to swivel. The bars are fitted inside a pair of aluminum blocks. The blocks rotate with respect to each
other with the use of a shoulder bolt. The umbrella is
fixed to the end of the arm with hose clamps. The
umbrella is also supported with machined sheet steel.
To assist the movement of the umbrella arm, retractable cords are mounted on the wheelchair near or below the armrests. Each cord retractor is attached to
the chair by nylon straps enabling the device to be
easily adapted to different chairs.
One drawback of the device is mild difficulty when
mounting it on the chair. The device requires the use
of a screwdriver or socket to tighten and loosen the
hose clamps. Another disadvantage is the complex
multi-step procedure required to open the umbrella.
The user may learn the procedure with practice.
However, the procedure should be simplified in future work.
$50.
User Instructions for Wheelchair Umbrella
To Deploy
1.
Unlock left cord retractor.
2.
Pull out cord to black mark.
3.
Lock left cord retractor.
4.
Unlock right cord retractor (if locked).
5.
Grab right cord, extend arm out a little and
pull on cord to swing umbrella to the side.
6.
Reach out and push button on umbrella
(unfolds umbrella).
7.
Reel in cord to bring umbrella towards body
for coverage.
8.
Lock right cord retractor.
To Bring to Stored Position Behind Wheelchair
1.
Unlock right cord retractor.
2.
Pull out right cord to black mark and lock
right cord retractor (provides cord slack).
Figure 13.18. Wheelchair Umbrella Deployed.
WHEELCHAIR PROPULSION DEVICE
Student Designers: James Poon, Peter Liu
INTRODUCTION
An ergonomic method for manual wheelchair propulsion was developed. Incorporating a relatively
higher mechanical advantage, an ergonomically advantageous system was designed, enabling reduced
expenditure of energy during manual wheelchair
propulsion.
Higher mechanical advantage is accomplished
through a four-bar linkage mechanism, which also
improves ergonomics with regard to the position of
the input forces.
The initial cost of manual wheelchairs (some range to
$1000) is prohibitive to the design of a highly integrated propulsion mechanism. Modularity was considered in the design of this device to offset the potential high initial costs. Further design considerations
include simplicity and aesthetics of the device.
SUMMARY OF IMPACT
The primary users of this device will be individuals
who already own manual wheelchairs. The reduction of the input forces reduces strain on the back by
relocating the point at which the input forces are applied to the arm level.
The existing method of manual wheelchair propulsion results in a high degree of strain on the user’s
back due to a lack of mechanical advantage. The current system involves a four-bar linkage mechanism
that relocates the point at which the input forces are
applied and provides improved mechanical advantage to the system. The mechanical advantage is further optimized through fine analysis of the angles
and lengths within the linkage mechanism, and an
increased output angle to maximize the output with a
standard input. This analysis is executed by computer calculations.
Figure 13.19. Propulsion Device Mounted on
Wheelchair
The highly visible nature of this device further introduced the criteria of a compact and aesthetic design.
Further considerations included the following:
•
Modularity, such that the device could be
purchased as an add-on module;
•
Compatibility with a majority of manual
wheelchairs;
•
Simple interface with overall wheelchair system allowing for easy installation without the
use of power tools.
•
Flexible usage allowing for movement in forward and backward directions.
•
Ergonomic quality with reduced input force.
Another goal was a lightweight construction. However, this was offset by the need to incorporate steel
for strength at the specific points where the force acts.
Figure 13.20. Close-Up of Drive Mechanism.
$150.
HEAT EXCHANGER TO PREVENT OR REDUCE
EFFECTS OF EXERCISE-INDUCED ASTHMA
Student Designers: Victor Kosmopoulos, Aaron Mason, Matthew Torniainen
INTRODUCTION
A temporary increase in airway resistance for several
minutes after a person has stopped strenuous exercise is referred to as exercise-induced asthma (EIA).
Approximately 12% to 15% of the general population
is believed to suffer from EIA at some point during
life. The exact causes of EIA are not entirely known,
although several hypotheses exist. Primary agitators
include cooling of the airway, water loss, and the
temperature gradient. Currently, there are many
pharmacological methods of dealing with EIA, but
few non-pharmacological alternatives. Suggested
non-pharmacological means to reduce this problem
include warm-ups and cool-downs before and after
exercise, continuous physical exertion, and warm,
humidified air. Since the effectiveness of warm-ups
and cool-downs varies and since continuous physical activity is not always possible or desired, the objective of this project was to design a device that
warms and humidifies inspired air.
The device consists of two basic components, a
breathing mask and a plastic tube used as a heat exchanger. Air is breathed from the end of the tube and
into the breathing mask. As the air travels to the
mouth, it is warmed by body heat and moistened
through small holes in the tubing. With this device
one who suffers from EIA can reduce or even eliminate the effects after exercise has ceased.
SUMMARY OF IMPACT
This inexpensive, reliable heat-exchanging mask allows people who suffer from EIA an alternative to
pharmacological methods. This mask is simple to
wear and durable for use during various exercises.
Although the aesthetics are not pleasing, its weight is
minimal.
The goals of the design were to produce a heat- exchanging device, which would be inexpensive, lightweight, reliable, durable, easy to assemble and strap
on, safe, efficient, and aesthetically pleasing. The design began as a counter-flow heat-exchanging mechanical device. That design led to an electrical coil
heating device and finally the simple device seen in
Figure 13.21.
Heating and moisturizing of the air, while still allowing for a flow rate not restricting to the body, were of
major concern. Due to the power required to achieve
this temperature gradient, an unacceptably heavy battery pack would be necessary for the counter flow
heat exchanger and the electrical coil heater.
The current device is strapped to the body underneath the clothing. During exercise the body produces heat and perspiration as it attempts to achieve
equilibrium. The body acts as a heat exchanger when
inhaled cold air travels through the respiratory system and is exhaled as warmer air. The device utilizes
the work of the body to heat the inspired air. The
small holes in the tubing allow moisturizing of inspired air, as the holes are near the moist body when
the device is strapped in place. The tubing also facilitates maintaining moisture from the exhaled air for
the next breath of inhaled air. All goals of the design,
except aesthetics, were achieved with this device.
$45.
Figure 13.21. Breathing Mask and Tube Heat Exchanger.
UTENSIL HOLDER HAND BRACE
Student Designers: Juyeun Yoo
INTRODUCTION
Hand injuries or chronic hand conditions can impair
the ability to pinch or articulate fingers. Patients may
have pain while grasping utensils, or may be incapable of holding utensils.
A prototype was designed to enable a person with
limited use of his/her hands to hold with stability
ordinary utensils such as a spoon, fork, razor, knife,
or pen.
SUMMARY OF IMPACT
The Utensil Holder Hand Brace assists patients with
chronic or temporary hand conditions with tasks
such as eating, writing, or hygiene. This design relieves pain from imposing pressure to the utensils
and thus helps patients use the implements, even
when unable to coordinate their fingers.
Most ordinary utensils fit into the Utensil Holder
Hand Brace, thereby eliminating the need to spend
money on expensive, custom-made utensils. Furthermore, the brace is easily maintained and easily
slips onto a person’s hand.
During creation this design, the basic hand shape
and its kinematics were studied by observing different hand positions of persons holding various implements.
In building the prototype, the selected materials were
Aquaplast and Polyform. The advantageous features
of the material properties are shown in the Table
13.3.
Properties
Description
Heating Time
150°F to 160°F water immersion for
1 minute.
Molding
Material not required to be very
hot, permitting direct placement in
patient’s hand. Three to five minutes working time.
Bond Ability
For permanent bond, pinch heated
surfaces together.
Table 13.3: Properties of Aquaplast and Polyform
The design of the utensil Holder Hand Brace was divided into the following segments: the holder, the vertical interface, the horizontal interface, and the hand
piece.
The hand piece was made with Polyform, while the
remaining components were made with Aquaplast.
Individuals with different hand sizes tested and
evaluated the finished model and reported that it fit
comfortably. The brace can hold objects of uniform
thickness of 0.5 cm to 1.5 cm. Utensils neither move
nor detach while undergoing a task.
$25.
Figure 13.22. Utensil Holder Hand Brace with Pen and Knife.
CHAPTER 14
TEXAS A&M UNIVERSITY
College Station, TX 77843
William A. Hyman (409) 845-5532
[email protected]
173
OPTIMIZATION OF ENVIRONMENTAL
CONTROL TO FIT A SMALL LIVING SPACE
Designer: Maxim Eckmann
Client: Russel Rawlings
Student, Texas A&M University
Supervising Professor: W.A. Hyman
Biomedical Engineering Program
College Station, Texas 77843
INTRODUCTION
An Infrared Point and Click subsystem was designed
as a low cost environmental control system (ECS) intended for people with disabilities in a dormitory
room. ECSs enable improved access to appliances
and other environmental assets in their homes. The
systems must be able to accept many forms of input
from devices, such as sip/puff switches or push buttons, and translate this input into many different
forms of output.
Most ECSs are not optimized for the dormitory room
environment; they have inappropriate functions that
can be wasted. This waste reduces their cost effectiveness. Currently, the price of fully functional ECSs
ranges from $1000 - $6000. Reduction of cost and optimization of environmental control in small living
spaces (like a dormitory) would make ECSs more
available to and practical for college students.
SUMMARY OF IMPACT
The adaptation of home automation for people with
disabilities has greatly improved the accessibility in
the home environment. The modern ECS has become
sophisticated and is able to provide a large range of
environmental controls and flexibility for users.
The current ECS appears to have the capability to
adapt to any situation and almost any user. Almost
complete control over appliances can be achieved. It
would be possible to use all available functions in a
house, but full functionality would not realistically be
achieved in a small one-room environment.
The components of the Infrared Point and Click system were built and laboratory tested. The client did
not return to school. Thus, the subsystem remains
untested in the field.
OUTPUT METHOD: THE IR RECEIVERS
A standard remote control, the Joystick TV Remote
Control (detailed later), or a simple IR transmitter may
be used to activate the receiver. A simple IR transmitter, designed with the client's abilities in mind, was
built for use with the receivers. It features a 15-pin
connector similar to those found on many joysticks.
A schematic is shown in Figure 14.1.
This circuit uses 555 TTL IC’s (timer chips). In combination with the correct resistor and capacitor values, the three 555 timers create square wave oscillator
circuits at the desired frequencies. R1 is connected to
pins 7 and 8 on the 555 timer IC. R2 is connected to
pins 7 and 2. C is connected to pin 2 and ground. Increasing R2 in comparison to R1 makes the duty cycle
even. R 1 should not be less than 1kΩ.
One 555 timer drives the infrared emitting diode. Its
fundamental frequency must be 38 kHz for the optimal response in the IR receivers. The timer can be activated directly with pin 14, resulting in a positive
output from an IR detector module in a receiver. Activation of pin 14 issues one command.
The other two 555 timers oscillate at approximately 2
kHz and 5 kHz. These timers drive the main 38 kHz
timer, creating 2 and 5 kHz bursts of the 38 kHz signal. In an IR detector module, this produces square
waves at 2 and 5 kHz, corresponding to two additional commands.
Chapter 14: Texas A& M University 175
1
14
3
R1
1E3
R0
47E4
8
7
6
4
5 kHz
3
DIP Socket
R1
1E3
8
R0
47E4
555
2
7
4
2 kHz
3
555
6
6
7
8
2
1
1
C3
1E-9F
C3
1E-9F
1
3
Dip Pin 14
D3
Optional
D2
Optional
R1
1E3
R0
47E4
+6.5V
4
5
6
8
7
555
6
4
3
8
9
D_IR
Infrared
2
12
14
15
1
15 D
Connector
C3
1E-9F
+6.5V
+6.5V
Figure 14.1. Schematic of a Simple, Thee-Command IR transmitter.
A lever style switch was built for the transmitter.
Pulling on the lever results in an emission of a 38 kHz
square wave IR signal. The control switches plug
into the 15 D connector. Power is bridged by the
switches through the transmitter's 6.5-volt battery
pack (4 AA batteries), to pins 3, 6, and 14. Simple
push buttons may be used as the switches, but there
are many options that could potentially be used. The
switch must use a 15 D connector and have the appropriate pin connections as given in this design to
activate the transmitter.
The system uses a network of simple IR activated
power relays. This provides control over lamps,
on/off type appliances and the thermostat setback
module.
Circuitry in the receiver stores the current state of the
device. When a strong IR signal at the proper fre-
quency is detected, the state is toggled. Toggling of
the state also toggles a 5-volt relay, the contacts for
which are rated for an amount of power sufficient for
the appliance. The relay bridges a connection between the wall outlet and the appliance that is
plugged into the receiver.
Figure 14.2 shows an electrical schematic for the IR
receiver. The entire system is designed to run between 5 and 6.5 volts, optimally. This voltage is provided by a DC power source that plugs into a jack on
the receiver. Note that the output from the IR detector
module must be run through an in verter (74LS04),
since it is originally active low. A 555 timer IC is used
to create an oscillating square wave, serving as the
clock. In this case, a NE556N (dual) timer IC was
used because it was readily available. The IR detector
module is a standard component, part #276-137,
available from Radioshack. It measures approxi-
1 kOhm
IR Receiver Schematic
NE556N
1
14
Vcc
2
8.3
MOhm
120 V AC
4
Vcc
CLK (5)
6
0.1 uF
7
8
Coil
74LS76
CLK
1
16
2
Vcc
Vcc
3
14
4
13
74LS04
1
14
2
5
11
10
8
9
8
IR Detector
Module
IR
Signal
9
Figure 14.2. Electric Wiring Diagram of a Toggling Relay Circuit that Responds to IR Input.
mately 1.5 x 1.5 x 1 cm. Circuitry in the detector has a
band-pass response of 38 kHz. The IR detector can
recognize signals from the Switch Activated IR
transmitter, or any standard remote control. The output of the detector is connected to pin 11 of the inverter (74LS04), since it is active low and a high output is required to toggle the J-K latch.
The detector module is so sensitive that the operation
of a TV remote control can trigger a receiver as far
away as 15 feet. Therefore, optical obstruction of the
receiver with a 0.5 mm thick piece of opaque material
(such as aluminum or plastic) is employed to reduce
sensitivity. When a remote control is within 3 feet of
the receiver, toggling of the relay is effective. Direction has an effect on selection as well, as the optical
signal strength attenuates with increasing angle.
Thus, both proximity and direction are employed to
perform selection and activation simultaneously.
A J-K latch (74LS76) stores the state of the receiver.
The latch receives a clock from the NE556N timer. If
there is a DC signal at pin 4 of the latch during an
upward clock transition, the state of the latch output
(pin 14) will change. The state output of the latch, pin
14, is used to activate/deactivate the magnetic switch
in the relay. The signal is first passed through the
hex inverter to buffer the signal. Current loading on
the 74LS76 output may result in instability in the
state.
A typical NPN transistor is used as a simple current
driver; the TTL components are not able to provide
enough current for some of the larger relays. The relay interrupts the power to one prong in a 3-prong
adapter. The controlled appliance plugs into the
adapter, which is then plugged into the wall. The receiver is connected to this adapter by a cable.
JOYSTICK TV REMOTE CONTROL
The Joystick TV Remote Control is a device modification of an existing programmable remote control. The
main function buttons (power, volume, channel) on a
One For ALL remote control are connected via ribbon cable to a digital joystick. Some users with
physical disabilities can use this improved joystick
interface instead of the smaller buttons on the regular
remote control, which are often difficult to manipu-
late. Design specifics for this modification are available from Dr. William Hyman, Biomedical Engineering Program Chair at Texas A&M University. Materials used in the construction of this device cost approximately $50.
INTEGRATION WITH OTHER SUBSYSTEMS
Integration of the Infared Point and Click subsystem
with other subsystems can provide most functions requested by the client. This system currently provides
no definite solution for light switches. The basic receiver could be used to interrupt the light switch circuit. Otherwise, lighting can be controlled through
the on/off toggling of lamps plugged into the receivers. Temperature control is also available. Use of the
Joystick TV Remote Control, existing garage door
openers, and an RC100 or RC200 telephone provide
the other functions requested by the client. Figure
14.3 shows the block diagram of this integrated system.
One function that cannot yet be implemented is control over the blinds. A modified receiver must be designed for this control option. The state output of the
latch can be tied to reversed relays that alternately
supply power in one direction or another to a motor
in the presence of an incoming signal. Latch output
and IR detector output would be ANDed together
with an AND IC at the connection to each separate relay magnet. The motor, with appropriate interface
and gearing, could then be used to open or close the
blinds.
DISADVANTAGES
If a switch-controlled telephone is used, assistance is
required to obtain the switch. Also, while depression
of almost any button on a standard TV remote control
can activate a receiver, use of the remote control on
the receiver could inadvertently affect the television.
Blind control, the least important function on the client's list, is not currently available.
The receivers' designs do not include an onboard
power supply that can harness the needed current
Integrated System with IR Point and Click Control
Mobile
Standard
Remote
Control
38 kHz
IR Emitter
Button
w/ 15 D
Connector
Stationary
Not yet supported
Light
Switches
IR Receiver
Relay
Appliances
and
Lamps
IR Receiver
Relay
Thermostat
Setback
Controller
Not yet supported
IR Receiver
Relay
Joystick TV
Remote
Control
Television
Voice or
Switch
Specialized
Telephone
2 Garage
Door
Controllers
Powered
Door
Openers
Figure 14.3. Environmental Control System.
from the incoming AC power. While a simple power
supply could be implemented, the current design uses
a 6V DC power supply that must occupy its own outlet. If there were a shortage of outlets, power strips
would need to be purchased.
ADVANTAGES
The system has eliminated complex centralized control at a tremendous savings in cost. Each receiver's
materials cost is approximately $25. This cost could
be reduced by the in tegration of an onboard power
supply.
The material cost of this system is $650. This in cludes 8 receivers, 8 power supplies, 2 power strips,
the Joystick TV Remote Control, and the RC200
phone. The telephone comprises the majority of the
cost ($400).
AN ARM BRACE FOR USE BY PATIENTS WITH
LOWER BACK TROUBLE
Designers: Price Bradshaw III and Robert Meltzer
Client: Nicholas Cram, Director of Bioengineering
St. Joseph's Medical Center
INTRODUCTION
An arm brace was designed for a patient who had recently undergone lower back surgery and required
support of the right arm. The brace is composed of
three components: a lower back support, a lower arm
support band, and an extendable rod attached to a
pair of universal joints (Figure 14.4). The device is
light, reasonably comfortable, and easily secured.
SUMMARY OF IMPACT
The client was a dentist who had recently undergone
lower back surgery. The nature of his work requires
long periods of time spent with his arms extended,
causing lower back strain. The device reduces this
strain by transferring the weight of the arm directly to
the hips and legs. The design of the brace includes a
set of steel rods that extend from the right arm to a
back support belt worn around the waist. This design successfully reduces strain in the lower back.
The brace was designed for a specific patient but
could be used for a number of individuals. The design requirements for the arm brace were that it: 1) relieve the strain on the lower back caused by the extension of the arm; 2) allow unrestricted range of motion
of the arm; and 3) be lightweight and comfortable.
The arm brace is made of a standard lower back support belt, a lower arm brace similar to those used for
tennis elbow, a hollow steel rod, a threaded steel rod,
a nut, two cotter pins, and two universal joints. One
universal joint is riveted to the outside of the back
support belt on the right side. A cotter pin attaches a
12” hollow outer rod with a 0.5” inner diameter to
Figure 14.4. Completed Arm Brace
this joint. A 0.5" nut is attached to a 0.5" threaded
rod, 14” in length, to act as a stopcock. The nut can
be used to change the length of the supporting brace
by rotating it clockwise or counterclockwise. The
threaded rod and attached nut are inserted into the
hollow rod. The free end of the threaded rod is riveted to the lower arm support to complete the assembly (Figure 14.5).
The pair of universal joints at either end of the rods
allows an almost unrestricted range of motion. The
maximum extension distance of the rods is 26" and
the minimum is 14". The device design is effective but
the lower arm brace can reduce circulation if it is applied improperly or worn for extended periods of
time.
The approximate cost of the arm brace is $45.00.
Arm brace
attached to joint
with pop rivets
Back support belt
velcro closure
with lumbar support pad
2 X universal joints
connected with cotter pins
Steel rod
Figure 14.5. Arm Brace Assembly.
AUGMENTATIVE COMMUNICATION DEVICE
Designers: Gretchen Meyer and Emily Stephenson
Client Coordinator: Mrs. Peddicord
Music Therapist, Bryan Independent School District
INTRODUCTION
Augmentative communication devices are used in
many school and therapy settings with students who
have few or no speech capabilities. These devices
provide a means for students to express themselves
and to receive audio feedback corresponding to specific commands they have selected. An augmentative
communication device can be defined according to
the number of cells, or individual selections, the device provides. These cells are associated with a specific symbol or command. Each individual cell can be
attached to an access mechanism that facilitates the
audio feedback. The number and size of cells required is dependent on an individual’s cognitive and
motor abilities.
There are many different ways a user can access the
system. These include touch, a remote switch, a
scanning system, auditory scanning, and optical
pointing. Finally, a digitized or synthesized speech
recording and playback device must be integrated.
This project incorporated multiple remote switching
devices (Figure 14.6). Four digital voice recorders,
manufactured by Marlin P. Jones and Associates,
were adapted for AC power. Each recorder used in
this device can hold 10 seconds of speech.
SUMMARY OF IMPACT
Two augmentative communication devices were designed for specific students, but can each be adapted
for various users. The first device was intended for a
seven-year-old boy with autism. He had minimal
speech capabilities and could not communicate with
his teacher. He had been using a device, designed by
his teacher, that consisted of a large piece of paper
with pushpins. Various objects were suspended on
the pushpins to communicate when he wanted to
Figure 14.6. Augmentative Communication Device
swing, color, eat, use the restroom, etc. The device did
not provide auditory feedback.
Digital voice recorders were used to design an augmentative communication device with four cells.
Each cell, consisting of a remote switch, has a picture
that represents something the child might want to express. When the switch is activated, the speaker
plays a verbal message that corresponds to the student’s choice. The device gives the student a way to
communicate and provides auditory feedback to facilitate his speech development.
The second device was designed for a four-year-old
boy with De George’s Syndrome, a disease that affects
the immune system. Due to his weak immune system,
this child had no interaction with anyone but his
parents and doctors for the first three years of his life.
This lack of interaction with others has severely affected his communication skills. A device similar to
the first was used with primary design alterations in
the cell specifications and the recorded speech.
Each voice recorder was originally designed for battery (DC) power. Since the voice recorder continually
uses power to maintain memory, the batteries die
within two weeks. To resolve this problem, the four
recorders have been converted to AC power by connecting each in parallel to an AC/DC adapter
(Fig14.7). The device can now use AC power from a
wall socket and retain memory as long as it is
plugged in.
Play
Switch
Record
Switch
Play
Switch
Record
Switch
Figure 14.7. Device Configuration.
Play
Switch
Record
Switch
Each voice recorder was purchased with a standard
play switch built into the mechanism. Record
switches are added using momentary push button
switches. After the recorders were adapted they were
enclosed in a 15.5" x 8" x 1.75" wooden box.
The total cost of each device is approximately $60.
Play
Switch
Record
Switch
DC
Power
Jack
AC/DC
4.5/6 VDC
Adapter
CLOTHES DRYER WITH FRONT MOUNTED
CONTROLS FOR HANDICAPPED ACCESS
Designers: Jon Berkovich and Chris Stamper
INTRODUCTION
A clothes dryer was adapted to make the task of doing laundry simpler for people who use wheelchairs
(Fig. 14.8). The design of the device is simple. The external control panel for the dryer was moved from the
back to the front of the dryer and mounted with metal
clamps. The internal wires were lengthened and a
rectangular section of the dryer cover was removed to
allow the wires to reach the controls. The dryer
model was equipped with a front lint catcher, allowing the device to be used without external assistance.
SUMMARY OF IMPACT
Moving the dryer controls from the back to the front of
the appliance enables wheelchair users to more easily
dry their laundry.
The design requirements for the dryer were that it: 1)
have a front lint catcher; and 2) have controls that are
accessible from a seated position.
A GE model DDE 7500VALWH, serial number VA2 1
7 4 1 6 G, was used in this design. A 20" x 2"
rectangular portion was removed from the front of the
top cover of the dryer to provide space for the wires to
reach the control panel. Each wire was lengthened by
6" using 150ºC, 12-guage electrical wire. Fourteen 16guage male/female adapters were used to connect the
existing wires with the new additions. Standard electrical tape insulated all wires exposed to the thermal
environment of the dryer. Finally, two 2" oval
stainless steel clamps were attached to each side of
the dryer lid to ensure that the cover remained securely fastened.
The cost of the modified dryer was $160.
Figure 14.8. Front Mounted Dryer Controls.
ADAPTED SEE’N’SAY FOR CHILDREN WITH
LIMITED DEXTERITY
Designers: Price Bradshaw and Rosalyn Metcalfe
INTRODUCTION
Children with limited dexterity often have difficulty
operating toys such as the See’n’Say, which require
physical manipulation. Because the See’n’Say is operated by pulling a lever, it requires both strength and
dexterity. This toy was adapted by connecting a push
button to a circuit to activate the lever (Figure 14.9).
SUMMARY OF IMPACT
The design was successful in allowing a child with
poor dexterity to operate a See’n’Say with ease. Due
to design limitations, the recordings were not played
in full. Using a longer connecting chain may rectify
this problem. In addition, the modified toy is not easily portable because the wood base is too heavy and
bulky for a small child. This design is the first step
towards a workable solution.
A ratchet and an industrial-strength circular fan motor were wired into a timing device activated by a
push button. The See’n’Say lever was connected to
the motor and ratchet with 1/8” brass safety chain. A
sprocket type ratchet system was used to allow only
unidirectional rotation. The timing device, referred to
as a “one shot,” is commercially available from IDEC
Industries. The device was used to engage the motor
for approximately two seconds.
During the two seconds, the motor rotates, pulling the
lever of the toy downward, providing energy for the
operation of the toy. After two seconds the motor
stops rotating and the lever returns to its initial position, allowing the See’n’Say recording to be played.
The See’n’Say is elevated on a 4” x 4” wood block to
allow the lever to clear the ratchet. The entire system
is mounted on ¾” plywood with L brackets.
Figure14.9. Adapted See’n’Say.
CHAPTER 15
UNIVERSITY OF ALABAMA AT
BIRMINGHAM
Department of Materials and Mechanical Engineering
BEC 254, 1150 10th Ave. S.
Birmingham, Alabama, 35294-4461
Alan W. Eberhardt (205) 934-8464
[email protected]
187
SHOWER CHAIRS FOR INDIVIDUALS WITH
CEREBRAL PALSY
Designers: 1998 Mechanical Engineering and Materials Science Senior Design Students
Client Coordinators: Dr. Gary Edwards, United Cerebral Palsy of Birmingham
Supervising Professors: Drs. Alan Eberhardt, B.J. Stephens, Laura Vogtle*
*Division of Occupational Therapy
University of Alabama at Birmingham
Birmingham, AL 35294-4461
INTRODUCTION
Shower chairs currently on the market have failed to
meet the needs of clients with cerebral palsy and their
caregivers. Shortcomings include:
•
Frames too weak for heavier clients, failing
with repeated use;
•
Mesh backing uncomfortable and abrasive
to skin;
•
Castors prone to rust, restricting mobility;
•
Users’ arms and legs protrude and catch in
open sides;
•
Clients may slide off seat; and
•
Cleaning difficult due to low seat height.
Three different shower chairs were developed for
three clients with varying conditions of cerebral
palsy:
•
an elderly man weighing approximately
300 pounds;
•
a thin man with severe kyphosis of the upper spine, fused spinal segments in his
lower spine, and knee flexion contractures;
and
•
a young woman, weighing less than 100
pounds, having severe curvature of the
spine and spasticity of the arms and legs.
Many issues are considered in the design of the
chairs, including durability, comfort and safety.
PRELIMINARY DESIGN
The preliminary design establishes the foundation for
the specific designs by focusing on the following five
major areas: the structural frame, adjustability, mobility, seating, and safety. The material for the frame
was AISI-Type 304, satin-finish stainless steel thin
walled tubing that meets the requirements for high
strength, low weight, corrosion resistance, and aesthetics. The frame components are joined by gas argon arc welding, according to specification AWS
WP1-01. Certified contractors performed all tube
bending and welding. The preliminary chair design
is shown schematically in Figure 15.1. This structural configuration was analyzed using Caesar II finite element software (Algor Inc., Pittsburgh, PA) for a
distributed load representing a reclined 300-pound
person. All frame members and joints yield safety factors greater than two. The 32.5-inch seat height
makes cleaning easier for the caregiver.
There are two large solid rubber wheels in the rear
and two smaller swivel type casters in the front to
make the chair mobile. The brake-type casters are 4
inches in diameter and 1.5 inches in width, designed
for a maximum 250-pound load. The metal components of the rear wheels and the front casters are
stainless steel, ensuring durability and corrosion
resistance.
Chapter 15: University of Alabama at Birmingham 189
9
ITEM
REF.
NO. DWG NO.
1
B-01
2
B-02
3
M-01
4
M-02
5
----6
----7
----8
M-03
9
----10
M-04
11
----12
----13
----14
----15
B-03
16
----17
M-06
18
M-07
19
M-08
20
M-09
21
M-10
22
M-11
23
B-04
24
----25
M-10
26
----27
C-01
28
C-02
29
M-05
30
M-12
29
7
15
11
8
26
14
12
24
23
25
DESCRIPTION
MAT'L
QTY.
1" DIA -12 GAUGE TUBE
1" DIA -12 GAUGE TUBE
1/4" THICK PLATE
1/4" x 1 1/2" BAR
1" DIA -12 GAUGE TUBE (39" LENGTH)
1" DIA -12 GAUGE TUBE (18 3/4" LENGTH)
1" DIA -12 GAUGE TUBE (22" LENGTH)
1 1/4" DIA - 12 GAUGE TEE
PADDED SEAT BELT
1/4" x 1 1/2" BAR
PADDED SEAT
24" DIA WHEEL
4" SWIVEL LOCKING CASTER
HANDGRIP
BACK FRAME ASSEMBLY
1 1/4" DIA TUBE (2.5" LENGTH)
LEG REST ADJUSTMENT PLATE
LEG REST ADJ. PLATE (SEAT ATTACHEMNT)
LEG REST HINGE ASSEMBLY
LEG REST ASSEMBLY
SEAT ADJUSTMENT ROD ASSEMBLY
BACK ADJUSTMENT ROD ASSEMBLY
ARM REST FRAME
ARM REST PAD
3/8" DIA SOLID ROD, BENT AND COVERED
3/8" DIA SOLID ROD, (24" LENGTH)
COVERING MATERIAL FOR BACK FRAME
COVERING MATERIAL FOR LEGREST
SEAT FRAME ASSEMBLY
FOOT REST ASSEMBLY
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
NYLON
304 SS
FOAM
RUBBER
304 SS
GEL FOAM
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
304 SS
FOAM
304 SS
304 SS
CLOTH
CLOTH
304 SS
304 SS
2
2
2
2
2
2
6
4
1
2
1
2
2
2
1
4
2
2
2
1
1
1
2
2
1
1
1
1
1
1
22.00"
15 27
2
23
24
14
11
16
17
18
22
4
12
19
6
1
21
20
16
28
38.50"
10
35.25"
30
3
32.50"
25
5
13
50.50"
28.00"
Figure 15.1. Schematic of the Preliminary Chair Design.
A support arm attached to the backrest establishes the
angled position of the backrest, which fits into two
slotted sidebars (Figure 15.1). For the seat adjustment
there is a prop-hinge installed under the seat on each
side. To adjust the seat upwardly, a second horizontal support bar fits into two slotted sidebars attached
to the front frame. There is a handle beneath the seat,
enabling the caregiver to easily adjust the seat rest.
The leg rest rotates outward and locks with a positioning pin placed through pre-drilled holes.
Swing-away armrests provide easy transfer of the clients into and out of the shower chair. A 1.5" diameter
piece of tubing is welded to each side in the middle
near the base to act as a pivot. Another tube is
welded to the front side of the chair to act as a harness for the swing-away armrest. The armrest is rotated by lifting it from the harness and swinging it
toward the rear of the chair.
Fringe is welded to the bottom of the pivoting section
to prevent the armrest from coming completely out of
the rear tube. The armrests are fitted with padded
side panels to keep the clients' arms from tangling
during transport into and out of the chair. The footrest is designed to pivot from the leg rest as a solid
piece, allowing the footrest to remain with the leg rest
in any position. The one-piece construction prevents
the clients' feet from becoming entangled.
Since the clients’ skin comes in direct contact with the
chair back and seat, comfort is extremely important.
The backrest is made of awning material, which is
soft to the touch, waterproof and durable. A clip-on
padded toilet seat is use. It is durable yet comfortable,
and allows easy access to the groin area for the caregiver. The clip-on feature allows it to be rotated 90 or
180 degrees for custom fitting.
A seatbelt is attached. Its locking device is located on
the side of the chair frame to minimize discomfort. A
pad attached to the belt prevents abrasion. A basket
is attached to the backrest for storage of bathing items.
Figure 15.2. Shower Chair.
SHOWER CHAIR #1
Design Students: Robert Cooner, Leah Hardy, Dierdre Jackson, Lee Motes, Rafael Nunez, Otha Richardson, Sharron Williamson, Eddie Saunier
SUMMARY OF IMPACT
This shower chair was designed for a thin, frail man
with cerebral palsy. He weighs approximately 65
pounds. He has restricted hip flexion due to fusion of
sacral and lumbar vertebrae, severe kyphosis of the
cervical spine, and knee flexion contractures (45-60
degrees flexion). This chair enables him to shower
without the fear of falling out of the chair and without
pain. Unlike before, he is able to remain in the
shower long enough to allow for appropriate hygiene.
The primary design concerns were adjustability and
comfort in both inclined and reclined positions. The
client is extremely susceptible to pressure sores, so
special attention was paid to seat and backing materials. Adjustability of the seat backing was achieved
via tie-strings that secure the backing to the frame and
allow the backing to be loosened or tightened as desired to contour with the client’s back. The footrest is
constructed of a stainless steel plate, attached to the
leg rest. The foot and leg rest are attached directly to
the seat so that they move with it, maintaining the desired angle. The toilet seat substrate is an open back,
vinyl injection molded material clamped onto the seat
frame. The square seat was sized to be 18.375 square
inches because of complaints that the previous 21inch seat was oversized. This was overlaid with an
inflatable seat cushion (RoHO Inc., Belleview, IL) to
provide increased comfort. The center hole has an 8inch circumference for access.
The total cost of this shower chair is $1205.27. This
includes $805 for parts and $360 for fabrication.
SHOWER CHAIR #2
Design Students: Michael Ball, Tina Childress, Michael Gordon, Jana Jenkins, Kristi McLain, Mitch Mansfield, Darin Odom,
Tom Young
SUMMARY OF IMPACT
This shower chair was designed for a 300 lb. man
with cerebral palsy, mental retardation and partial
blindness. Previously purchased commercial shower
chairs were unable to support his weight and had
failed in service. As a result, he was usually bathed
in his wheelchair. This shower chair will extend the
life of his wheelchair by providing an appropriate
shower medium.
In this design, specific areas of focus included the
structural framework, ease of patient transfer from
wheelchair to shower chair, comfort and safety. The
client is above average in size, so the chair dimen-
sions are larger and the frame is made to support
more weight than the average shower chair. To increase ease of transfer, the seat height of the chair is
near the height of his wheelchair seat (approximately
26 inches). This structural configuration was analyzed using Caesar II finite element software (Algor
Inc., Pittsburgh, PA) for a distributed load of 1000
pounds, representing a worst case dynamic loading.
All frame members and joints yield safety factors
greater than two.
The total cost of this shower chair was $1,436.27.
This includes $1028.11 for parts and $436.16 for fabrication.
SHOWER CHAIR #3
Design Students: Shane Wolfe, Jeremy Wolfe, Jim Gaydon, Jana Jenkins, Lee Motes, Jeff Gordon, Mitch Mansfield
SUMMARY OF IMPACT
This chair was designed for a young woman with severe cerebral palsy. Specific design issues in this case
included comfort for her severely curved spine and
prevention of her arm and legs extending beyond the
chair, which has been problematic due to spasticity in
her arms and legs. The completed chair relieves pain
previously experienced by the due to ill-fitting
equipment.
The preliminary design met the basic requirements,
with minor modifications. The height of the seat back
was extended to allow for head support in reclined
positions. An 18 3/8" square-shaped, open front,
padded seat was used. The seat is equipped with
clips so that it can be easily removed, rotated, and repositioned, allowing the caregiver to optimally orient
the opening to accommodate the client’s spinal curvature.
The total cost of this shower chair was $1,500.57.
This includes $798.57 for parts and $702 for fabrication.
FOREARM MOTION/TORQUE ANALYZER
Student: Michael Wheatley
Project Coordinators: Drs. Stephanie Delucas1, Edward Taub2
1Spain Rehabilitation Center, 2Department of Psychology
Supervising Professors: Drs. Alan Eberhardt, Martin Crawford, Evangelos Eleftheriou
INTRODUCTION
A forearm motion/torque analyzer was designed for
patients recovering from strokes. It consists of a padded arm support and a grip that is moved through
pronation and supination of the forearm. Torque and
rotational motion are visually displayed on needle
gauges, permitting the evaluator a convenient measure of relative improvement in wrist and forearm
strength and range of motion. The guages also provide visual feedback to the patient during rehabilitation therapy.
SUMMARY OF IMPACT
Strokes may affect a person’s control of the musculoskeletal system and abilities to perform skilled behaviors. There is a need for a therapeutic wrist motion/torque analyzer to allow stroke victims and
evaluators to observe supination and pronation motor skills during rehabilitation. It also provides for
limb isolation, variable resistance, comfort and versatility.
The motion/torque analyzer consists of a padded
arm support, a mobile grip, a box housing spring and
damper resistance, and needle gauges for measurement of torque and rotation (Figure 15.3). The padded
armrest is attached to the device by a latch on each
side, facilitating storage and contributing to the mobility of the device.
The device restrains the patient's arm with adjustable
nylon D-ring straps to prevent the use of the shoulder
in rotation of the affected limb. A special set of gloves
allows the patients' hands to be secured in a
"gripped" position. The hand grip is configured to allow ambidextrous finger positioning. Since the device is to be used in a medical environment, all exte-
rior surfaces are non-absorbent and capable of withstanding repeated cleanings.
The grip is attached directly to a rack and pinion system that converts the rotational motion induced by
the patient into linear motion. Two extension dampers are attached to the rack gear, one on each end
(Figure 15.4). The stroke length of the cylinders was
chosen so that a 170-degree rotation of the pinion
gear does not exceed the stroke length of the cylinders. The hydraulic dampers increase or decrease the
amount of resistance to motion in response to the rate
at which they are deformed. The amount of resistance
is a direct function of the rate at which the patient rotates his or her forearm. Additionally, the dampers
do not increase resistance at range of motion extremes. Instead, as the patient reaches the extreme, by
reducing the rate of rotation, the resistance offered by
the damper decreases. As the patient's motor skills
improve, the resistance may be increased proportionally to the rate of rotation. The length of the rack gear
is sufficient to accommodate 85 degrees of rotation in
either direction. As a safety measure, the tooth spaces
on the rack gear corresponding to range of motion extremes are filled with epoxy.
Range of motion is measured directly from the shaft of
the pinion gear, which is also the shaft to which the
grip is attached. On the exterior of the device, a needle attached to the shaft indicates the degrees through
which the shaft is rotated (Figure 15.4). Two additional needles attached to, but independent of, the
shaft are used to indicate the maximum degree of rotation in both directions. The torque is measured according to the resistance offered by the damper. Since
the diameter of the pinion gear is known, the torque
will be the product of the damper force and the pitch
radius of the gear. The damper force is measured by
an extension spring attached in series to each of the
two dampers. The dampers are threaded into the rack
gear on one end. The other end of the damper is
threaded into an adjustable turnbuckle that attaches
to the spring through an eyebolt. Pins passing
through each of the adjustable turnbuckles indicate
the displacement of the spring to torque gauges
mounted on the exterior of the device. An indicator
needle on the exterior of the device attached to the pin
moves linearly as force is applied to the spring. It indicates the torque the patient is applying according to
a calibrated scale on the exterior of the device. A second freely moving needle, not attached to the spring,
indicates the maximum torque applied. The same
apparatus is used on both springs so that the torque
may be measured in both directions. The adjustable
turnbuckles allow the use of different springs and
dampers to accommodate patients who are exceptionally stronger (or weaker) than the average patient.
The total cost of the wrist motion/torque analyzer
was $420.61. This in cludes $176.61 for parts and
$244 for fabrication.
Figure 15.3. Wrist Motion/Torque Measuring Device.
Figure 15.4. Rack and Pinion, Hydraulic Cylinders, and Needle Gage Attachments.
WHEELCHAIR HEADREST DESIGN
Designer: Aaron T. Joy
Client Coordinators: Dr. Gary Edwards, United Cerebral Palsy of Birmingham
Supervising Professors: Drs. Alan Eberhardt, Martin Crawford, Laura Vogtle*
*Division of Occupational Therapy
INTRODUCTION:
A headrest was designed for a woman with cerebral
palsy. It restricts movement of her head to the left,
prohibits her chin from dropping, and offers support
to her head and neck. The device is constructed using
commercially available hardware and is custom fitted
to the client's head, providing comfort and cosmetic
integrity. A detachable forehead strap is fitted to the
device to provide additional support and prevent
forward movement.
SUMMARY OF IMPACT
The head rest/support system is for a woman with
cerebral palsy. The device allows her prolonged, accurate use of her augmentative communication device
and facilitates eating and swallowing. The design
provides comfortable support for extended periods of
time throughout the day, with a detachable forehead
strap that may be used when she is tired.
Figure 15.5. Headrest for Woman with Cerebral
Palsy.
Previous designs were not durable and had insufficient infrastructure. They did not support the client’s
chin and jaw, which tend to drop as she tired. Her
previous headrest also interfered with her eyeglasses
and the infrared sensor used for her voice activation
board.
Initially, a negative mold was made of the client’s
head and neck using plaster casting for subsequent
fitting of components. From the negative mold, a
positive mold was constructed for use in subsequent
development. For the purpose of structural frame and
attachment design, lateral and dorsal head forces
were measured using a bathroom scale.
Rather than developing new components, commercial
components were customized to minimize costs. The
Whitmyer SOFT-1D (Whitmyer Biomechanix, Inc.,
Figure 15.6. Rear View of Headrest Showing
Mounts.
Tallahassee, FL) was purchased because it met the
criterion for chin support. It consists of left and right
sub-occipital pads contoured to cradle the client’s
chin from ear to ear. One-half to one-inch clearance
was allowed for lateral and vertical movement, while
inhibiting movement to the left and cradling her chin.
The device was constructed of 14 gauge carbon steel
plate, covered by closed-cell polyethylene foam and
by water resistant Lycra that is soft to the touch. The
occipital pad was reduced in size relative to the client’s previous headrest to decrease interference with
her eyeglasses during movement. The pad is pre-
fabricated with a continuous plate of 14-gauge carbon
steel and is covered with the same materials as the
sub-occipital pads. The device is shown in Figure
15.5.
by means of switch mount clamps, internally located
in each pad. The occipital mount connects the occipital pad to the sub-occipital fork with another 7/8inch ball-rod.
The headrest is attached to the mounting system via a
12-inch WBI to BOCK vertical adjusting bar, an occipital mounting bar, and a sub-occipital mounting
fork (Figure 15.6). Each was constructed from seamless carbon steel tubing. The vertical adjusting bar
enables the Whitmyer system to be attached to an existing BOCK square mount on the back of the patient’s chair. The sub-occipital mounting fork connects both the left and right sub-occipital pads to the
vertical adjusting bar. At the end of each rod is a 7/8inch ball-rod, which attaches to the sub-occipital pad
A detachable forehead strap was attached to a pulley
system and mounted to the headrest for prevention of
vertical movement (Figure 15.7). The forehead strap is
attached when the client is tired. The strap attaches
to the occipital mount via a switch-mounting clamp.
The total cost of the headrest was $650. This includes
$540 for parts and $110 for fabrication of the plaster
molds.
Tension Adjuster
CRITICAL! Ear clearance
from cord of approximately 3/4"
Position ABOVE
user's eyebrow
Side View of Soft-1 Headrest
Figure 15.7. Forehead Strap for Headrest.
CHAPTER 16
UNIVERSITY OF TENNESSEE AT
CHATTANOOGA
College of Engineering and Computer Science
Chattanooga, TN 37403
Edward H. McMahon (423) 755-4771
[email protected]
197
BICYCLE FOR A SMALL CHILD
Designers: B. Parr, B. Plemmons, B. Vandagrifff
Client Coordinator: Jamie Castle Tennessee Early Intervention System
Supervising Professor: Dr. Edward H. McMahon
University of Tennessee at Chattanooga
INTRODUCTION
A bicycle was designed for an energetic, healthy, intelligent three-year-old boy with achondroplasia
(dwarfism). The pedal-powered device enables the
client, 28 inches tall, to propel himself in the same
way as other children his age. The criteria were ease
of mounting and dismounting, pedal power, safety,
and durability. The physical restrictions were primarily influenced by his eight-inch inseam and an
approximate 5 1/2" range of motion for his leg
movement. The initial design was based on a go-cart
frame; however, the family preferred a bicycle type
device.
The design is based on a single downtube with no
cross bar. A local world-class manufacturer of racing
bicycles assisted in construction.
SUMMARY OF IMPACT
The bicycle met the child’s needs. It was delivered
with training wheels and sufficient adjustment in the
seat to accommodate future growth. The bicycle was
delivered with 12" wheels but was designed to also
accommodate 16" wheels.
The frame was specially designed and built to accommodate the dimensions of the client. It was important that the client be able to get on and off the bicycle independently. Three frame designs were considered and the one shown below was selected. The
frame was made by a local bicycle manufacturer out
of titanium tubing.
The components for the bicycle were standard, modified as necessary. The front and rear sprockets each
have 18 teeth. Either or both may be changed when
the child is older. The crank was modified to a 3.5"
Figure 16.1. Bicycle for a Small Child.
radius. The spindles, bearing cups, bearings, pedals,
and wheels were standard, as well as the chain, fork
and stem. A standard seat post was welded to the
frame and a standard seat was attached.
The forks used were made for 16" wheels, although
the wheels delivered with the bicycle were 12". Standard training wheels were attached.
The cost of the parts for the bicycle was $275. The
frame was manufactured and donated by the bicycle
manufacturer.
Chapter 16: University of Tennessee at Chattanooga 199
R9.00
12.00
R7.75
1.75
Figure 16.2. Diagram of Bicycle.
COMPUTER WORKSTATION
Designers: A. Elkhadrawy, A Guider, R. Ng, T. VanHoesen
Client Coordinator: Molly Littleton
INTRODUCTION
A computer workstation was designed for use by a
child. The client required a computer workstation
with a monitor adjustment from 24” to 40". In addition, the computer workstation should be mobile and
fit through a standard doorway (36" wide). The keyboard height was adjustable, and the keyboard could
be moved in and out at an adjustable angle. A commercially available keyboard was attached to the
monitor support. A motorized screw was used to adjust monitor height. A stationary CPU support was
built to accommodate a desktop or tower unit.
SUMMARY OF IMPACT
The workstation met the client’s needs. The child is
able to use the workstation while sitting or standing.
There are two primary components, the frame and the
adjustable monitor/keyboard support.
The frame was built primarily from 2" x 2" steel tubing. The overall dimension of the frame were 36L x
30"W x 12"H (excluding the casters). A triangular
support was used on the right side of the frame. A
square support was used on the left side of the frame
to accommodate the CPU table.
The square tubing was miter cut and welded to form
the frame. The CPU table was made from 3/4" White
Melamine coated board. The frame base was completed with 4" diameter nylon locking swivel casters.
A strap was added to the CPU table to secure the CPU
in transport.
The basis for the motorized lift was an electric screwdriven lift with a stroke of 12.5" and a lift speed of 10"
per minute. The operating range was from 25.5” to
38". The motor was mounted to the frame. The shaft
Figure 16.3. Computer Workstation.
end was mounted to the monitor shelf using a steel
plate welded to a center sleeve. To stabilize the monitor tray, two steel pipes were welded to the frame.
Two brass rods were attached to the monitor tray and
fitted into the steel pipe. The monitor shelf was made
of 3/4" White Melamine coated board. A strap was
added to secure the monitor during transport.
The keyboard support and tray were purchased. The
support was mounted under the monitor shelf. The
keyboard can be adjusted up and down, in and out,
and at an angle. The keyboard has a padded wrist
rest.
A power cord and three-way (up, off, down) momentary contact switch completed the construction.
The cost of the device was $600.
14"
Melamine finished
particle board
Brass 0.8" OD
Steel Pipe 0.814" ID
Linear Actuator
Melamine finished
particle board
2" X 2" Square Tubing
12"
36"
Figure 16.4. Diagram of Computer Workstation.
SUPPORTIVE DINING CHAIR
Designers: S. Grody, M. Hobbs, J. VanSteenburg
Client Coordinator: Rick Rader
INTRODUCTION
A chair was designed to enable a client with cerebral
palsy to sit at a dining table. In a standard dining
room chair, the client had to sit on the edge of the seat
so that his feet could reach the floor while he supported himself on the table. This position made eating difficult. Critical needs included support for the
feet above the floor, an ability to get into the chair, and
a sense of stability while in the chair. A chair was
designed using PVC pipe. A sliding footrest and
lightweight shoulder straps were added for support.
The sliding footrest retracts when the client enters the
chair and is slid forward to provide support for his
feet while he is at the table. The client can enter the
chair by himself. The shoulder straps enable him to
remain upright.
SUMMARY OF IMPACT
The chair allows the client to sit at the table and eat in
an upright position. The removable cushions are easily cleaned.
A primary concern was the design of the moveable
footrest. Mechanisms similar to those used on wheelchairs were considered but would have made footrest
adjustments difficult while the client's feet were under the table. The design selected was a chair made
from PVC piping (Figures 16.5 and 16.6).
The back of the chair was designed for maximum
support and rigidity. A second back support provides handles for moving the chair. The sliding foot
support was made by enlarging the inside diameter of
the fittings so they would easily slide over the PVC
pipe. The footrest is made from PVC cutting board
material. The back and seat cushions were made of
foam rubber covered with vinyl. The back cushion
has snaps at the top and bottom and the seat cushion
Figure 16.5. Photograph of the Chair.
has snaps on four sides for attachment to the PVC
pipe.
The chair sits on 2 3/4" locking/swivel casters. The
casters are attached to the PVC pipe frame by plugs in
the bottom of the PVC frame, drilled for the caster
shaft.
The PVC pipe and all joints were put together with
PVC glue.
The cost of the device, including the cushions, was
$300.
7"
REAR CUSHION
SEAT CUSHION
1' - 2"
8 1/8"
1' - 11 1/2"
3"' - 2"
10 1/2"
6 1/2"
6 1/4"
5"
1' - 1"
1' - 0"
2" - 6"
Figure 16.6. Diagram of Dining Chair.
LAPTOP SUPPORT
Designers: B. Bacon, M. Moss, B. Smith
INTRODUCTION
The laptop computer mount was designed for a 26year-old graduate with amyotrophic lateral sclerosis.
The client uses a laptop computer and a voice synthesizer to communicate. This requires a tray to mount
both the computer and an infrared device to access
the voice program. It was necessary that the support
be mounted on the left side of his wheelchair, be able
to swing out of his way with ease, be easily removable
and lightweight, and securely hold the computer and
sensor.
SUMMARY OF IMPACT
The mount met design criteria. The laptop mounts on
a vertical bar on the side of the wheelchair and is easy
to move out of the way to facilitate transfer to and
from the wheelchair. The laptop can be easily removed from the mount by unlocking a gate latch and
removing the tray and laptop as one unit.
The vertical mount was made from 18" long 9/16" diameter steel tubing. A hole in the tubing and a 1/4"
locking pin prevented rotation. The top of the rod
was threaded.
A 2.5"x 2.5" x 8" block of aluminum was drilled and
tapped for placement on top of the vertical support.
The threaded connection was secured with a 10-32
set screw. On the face of the aluminum block, at right
angles to the vertical support, two .5" holes were
drilled. The two supporting rods for the laptop tray
were made of aluminum 12" long and .5" in diameter.
One end of each of the rods was threaded and
screwed into the corresponding hole in the aluminum
block.
The tray was made of .5" thick gray PVC board. It
was 12.5" long and 10.5" wide. Four clear plastic .5"
Figure 16.7. Laptop Support.
diameter tube straps were secured to the bottom of the
tray using screws.
A gate latch secures the tray to the mount. The receiving portion of the latch was mounted to the aluminum block with screws. The post portion of the latch
was attached to the bottom of the tray using two
screws.
The computer was secured to the tray using four 4" x
2" pieces of industrial strength Velcro. For additional
safety, three small clamps were attached to the tray to
secure the computer.
The cost of this device was $80.
8"
2 1/2"
6"
12"
Al block drilled
and tapped
17"
1/2 inch diameter Al Rod
(rod threaded into blocks)
Figure 16.8. Diagram of Laptop Support.
PRINTER SUPPORT
Designers: Scott Brown, Bryan Crawford
INTRODUCTION
A printer mount for a wheelchair was designed for
use by a client with quadriplegia. The client uses a
Delta Talker, and augmentative communication device, and desired a printout of the text he developed
using the device.
SUMMARY OF IMPACT
A mount used previously interfered with the client’s
line of sight and did not provide the necessary clearance for the infrared signal to the Delta Talker. The
new printer mount secures the printer in an optimal
Figure 16.9. Printer Support.
position. It is simple to mount the printer. The mount
allows easy access to change paper.
The basis for the design was an aluminum double
gooseneck for a mountain bike. The tubular part of
the gooseneck (which normally goes into the bike
frame) was milled on an angle to produce a flat surface. Two holes were drilled in this portion for attachment of the printer mounting plate.
The printer mounting plate was constructed from a
single piece of 16-gauge aluminum. Tabs in the plate
support the printer and the printer paper roll. After
the plate was cut the tabs were folded for the printer
and paper. A 1/4” diameter rod was threaded on one
end and attached to the printer mount for the paper.
It was held in place by a wing nut. The printer
mounting plate was attached to the modified gooseneck by two bolts. To attach the printer mount to the
rod that supports the Delta Talker, the four bolts were
removed from the gooseneck and the mount was attached to the rod (where the bicycle handles would
normally be attached). The printer is attached to the
mount using Velcro.
The total cost for the device was $40.
Figure 16.10. Another View of the Printer Support.
CHAPTER 17
UNIVERSITY OF TOLEDO
Department of Mechanical, Industrial and
Manufacturing Engineering
Toledo, Ohio, 43606-3390
Nagi Naganathan, (419) 530-8210
[email protected]
Mohamed Samir Hefzy, Ph.D., PE. (419) 530-8234
[email protected]
209
ADAPTATION OF A RIDING LAWNMOWER FOR
A PERSON WITH PARAPLEGIA
Designers: Kevin Groff, Nick Homan, Ahmad Mamat, Shinta Maxfari, Rudy Santoso
Mechanical Engineering Students
Client Coordinator: Dr. Gregory Nemunaitis
Rehabilitative Medicine, Medical College of Ohio and St. Vincent Mercy Medical Center
Supervising Professor: Dr. Mohamed Samir Hefzy
Biomechanics Laboratory
Department of Mechanical, Industrial & Manufacturing Engineering
The University of Toledo
Toledo, Ohio, 4360
INTRODUCTION
The purpose of this project was to adapt a riding
lawnmower (Simplicity 6200) so that a person with
paraplegia could operate it, while still maintaining
the standard operation for use by able-bodied family
members. The clutch and seat were modified. A
clutch lever arm assembly was designed and built to
allow the client to depress the foot pedal using hand
and arm movements in stead of leg and foot movements. The seat was replaced to provide maximum
support for the client’s upper body and allow for easy
transfer from a wheelchair.
SUMMARY OF IMPACT
A clutch lever arm assembly was designed, built and
installed in a lawnmower to allow the client to operate it without use of his legs. This assistive device
will allow this person to gain more independence in
his daily living activities, thereby contributing to the
improved quality of life for him and his family.
Operation of the lawnmower requires depressing a
foot pedal (clutch pedal) to engage the brakes and simultaneously disengage the drive shaft. While the
foot pedal is depressed, the gears can be changed. Releasing the foot pedal disengages the brakes and engages the drive shaft. Therefore, modifications of the
clutch and seat were necessary to adapt this lawnmower for use by the person with quadriplegia.
CLUTCH LEVER ARM ASSEMBLY, DESIGN,
AND INSTALLATION
The existing clutch is foot controlled, thereby eliminating the opportunity for a person with paraplegia
to operate the lawnmower. A clutch lever arm assembly was designed, manufactured, and installed to allow the drive system of the lawnmower to be engaged
and disengaged using the operator's hands and arms.
The drive system of the lawnmower is a variable
speed pulley system. The distance the foot clutch will
travel backward, as the drive system of the lawnmower engages, is contingent on the gear of the drive
system. For example, if the drive system is in first
gear, the return travel of the clutch will be approximately one inch. Accordingly, if the drive system is in
second gear, the return travel of the clutch will be approximately two inches. In the highest gear of the
lawnmower, the return travel will be equal to the total
return travel of eight inches. The design of the clutch
assembly must allow for the varied return travel distance of the clutch.
Design criteria included that:
•
The modified clutch assembly provide a stopping time the same or better than that for the existing foot-controlled clutch;
•
The drive system remain disengaged without
assistance from the operator once the drive system is disengaged;
•
Potential leg and foot obstructions for the operator be eliminated;
Chapter 17: University of Toledo 211
•
the clutch assembly be easily removable, so family members can operate the lawnmower with
the foot-controlled clutch;
•
it be cost effective;
•
The structural integrity of the original mower be
maintained; and
•
The new clutch assembly be safe.
Several possible solutions were considered, including
a hydraulic cylinder assembly, a screw drive motor
assembly, a cable and pulley system, and a clutch
lever arm assembly with a bottom pivot or center
pivot. The clutch lever arm with a bottom pivot was
selected. A lever arm, pivoted at the bottom with a
rod hinged through a hole approximately six inches
above the bottom of the lever arm, was connected to
the clutch pedal. The lever arm assembly, located on
the clutch side of the lawnmower, was mounted on
the footrest. Pushing the lever arm forward forced the
hinged rod forward and in turn disengaged the
clutch and drive system of the lawnmower.
Figure 17.1.Modified Clutch Lever Arm.
The design and manufacture of the clutch lever arm
assembly included three components: clutch lever
arm, push pull rod, and clutch pedal. Each of these
included design of new parts, modifications of existing parts, and calculations for critical design points.
CLUTCH LEVER ARM
The lever arm, purchased from McBride Equipment,
Inc., is the same as that used to raise and lower the
mowing deck. It has a spring-loaded locking system,
which allows the operator to disengage the clutch
and use both hands to shift gears. The lever arm
comes with a 0.125-inch thick steel base plate to ensure secure mounting on the mower.
Three lever arm modifications were made. The first
consisted of decreasing the width of the steel base 2.5
inches because the original width of the base was too
wide and did not leave room for the operator to place
his foot to the inside of the lever arm. This modification necessitated the removal of a large angular steel
piece from the end of the rod through the lever arm
base.
The second lever arm modification was a result of the
first. Since the lever arm base had to be decreased,
Figure 17.2. Push Pull Rod Assembly.
only two bolts could be used to support and to connect the base of the lever arm to the footrest of the
lawnmower. The existing holes in the lawn mower
footrest are 0.25 inches in diameter. Design calculations indicated that two 0.25 inch standard grade
UNC-20 bolts would provide the required stability
and strength needed for mounting. This required
drilling an additional 0.25 inch diameter hole into the
base of the lever arm. The location of the hole was determined through visual inspection and marked on
site through the use of a scribe.
The third modification of the lever arm required relocation of the push pull rod hole. The original 0.625inch diameter hole, six inches above the base of the
lever travel distance of eight inches, was not sufficient
for engagement and disengagement of the lever arm.
A new hole was mounted 14 inches up on the lever
arm. The lever arm is bottom pivoted, so the higher up
Figure 17.3. Clutch Pedal Before Modification.
Figure 17.5. Clutch Bar Before Phase 1 Installation.
Figure 17.4. Clutch Pedal After Modification.
the hole is along its radius, the more travel distance
the hole provides. To provide additional adjustment
in travel distance, a 6” x 2” x 0.25” (length x width x
thickness) bracket with three 0.625-inch holes spaced
1.5 inches apart were manufactured. The new
bracket, shown in Figure 17.1, was welded to the lever
arm with the bottom hole 14 inches above the base of
the arm. Figure 17.1 shows the modified lever arm.
PUSH PULL ROD
The push pull rod of the Clutch Lever Arm Assembly
transmits the motion of the lever arm to the clutch
pedal. It consists of a 0.5 inch diameter steel rod 20
inches in length with a two-inch bend on one end, as
shown in Figure 17.2. The straight end of the push
pull rod is threaded up 8.375 inches from its end for
0.5inch UNC-13 nuts. On the two- inch bend end of
the push pull rod, there is a 0.125 inch through hole
for a standard cotter pin.
The bend end of the push pull rod goes through one
of the three holes of the lever arm bracket, with a
0.5inch washer between the lever arm and cotter pin.
There is also a 0.5 inch nylon bushing that attaches to
the bend end of the push pull rod after it has been put
through the lever arm bracket hole and before the cot-
Figure 17.6. Modified Clutch Pedal Mounted On
Clutch Bar After Phase 1 Installation.
ter pin and washer are installed. This nylon bushing
decreases the slack between the 0.5-inch-diameter rod
and the 0.625-inch diameter bracket holes.
The cotter pin and washer secure the push pull rod to
the lever arm. On the threaded end of the push pull
rod, there are two 0.5inch UNC-13 nuts snugly tightened against each other. On the rod end side of the
nuts, there is another 0.5 inch washer that goes between the nuts and the aluminum angle on the clutch
pedal, through which the push pull rod is inserted.
On the other side of the aluminum angle are two more
0.5 inch UNC-13 nuts tightened to snug tight condition against each other for safety.
CLUTCH PEDAL
The existing clutch pedal was modified so that it
would not have to be removed with either clutch assembly in place. Figures 17.3 and 17.4 show the
clutch pedal before and after modification, respectively. An aluminum angle was welded to the lip on
the backside of the pedal. A 0.5625-inch diameter
hole was located on the top side of the 3.75” x 3.5” x
0.25” angle in which the push rod would be inserted.
Figure 17.7. Clutch Lever Arm Attached To The
Footrest.
Figure 17.9. Existing Lawn Mower Seat.
Figure 17.8. Clutch Lever Arm Assembly Fully Installed
Figure 17.10. New Lawn Mower Seat.
The corners of the top part of the angle were rounded
to remove the sharp edges and to provide a finished
look.
FINAL ASSEMBLY
Figure 17.5 shows the initial lawnmower clutch. The
modified clutch pedal was reinstalled onto the existing clutch bar as shown in Figure 17.6. The lever arm
was then installed. Two 0.25-inch diameter UNC-20
bolts with corresponding nuts and washers were
used to attach the base of the lever arm to the footrest
of the lawnmower as shown in Figure 17.7. The bolts
were tightened to snug tight condition using a hand
ratchet wrench. Loctite™ bolt sealant was applied for
final assembly. The sealant keeps the bolts from coming lose due to vibration during operation.
Finally, the push pull rod was installed. The push
pull rod was screwed on to the rod using two 0.5-inch
UNC-13 nuts approximately six inches up the thread
from the end. A 0.5-inch washer was added behind
the two UNC-13 nuts. Next, the threaded end of the
push pull rod was inserted through the 0.5625-inch
diameter hole in the aluminum angle on the clutch
pedal. The 2-inch bend end of the push pull rod was
then inserted into the middle hole of the bracket
welded onto the lever arm. A 0.5-inch nylon bushing
was placed onto the 2-inch bend end of the push hole.
Next, another 0.5-inch washer was placed onto the 2inch bend end of the rod, past a 0.125inch cotter pull
rod, and into the middle bracket pin hole. A cotter
pin was then inserted into the hole. Two other
0.5inch UNC-13 nuts were screwed onto the threaded
end of the rod, approximately two inches away from
the backside of the aluminum angle.
The two 0.5-inch UNC-13 nuts on the front side of the
aluminum angle were adjusted to meet the comfort
and accessibility needs of the operator. Finally, all
four of the 0.5-inch UNC-13 nuts were tightened to
snug tight condition against each other, ensuring security and safety. Figure 17.8 shows a picture of the
fully assembled clutch lever arm assembly.
SEAT MODIFICATIONS
The existing seat of the riding lawn mower did not
have a seatbelt and provided no support for the upper
body. Without support and a seatbelt, the user could
possibly be thrown from the lawnmower. A new seat
and a seatbelt were added. The new seat met the following criteria:
•
Universal mounting to allow for easy installation and minor modifications to existing equipment;
•
Fold-up arms that allow for easy entry and exit;
•
High backrest and armrests to provide support
and security; and
•
Comfort for other operators.
Figure 17.11. Foot Clearance With Clutch Lever Arm.
A seat from Northern Hydraulics was acquired and
modified to attach a seatbelt. The backrest on the new
seat is 16.5 inches, which provided an additional 3.5
inches of support. Two foam-cushioned armrests
provide additional side support. During transfer, the
armrests can be folded up to allow the user to slide
onto the seat.
The seat was constructed of a steel frame, used for
seatbelt attachment. Figures 17.9 and 17.10 show pictures of the existing and new seats, respectively.
The new seat had to be slightly modified for secure attachment to the lawnmower. The new seat had four,
0.25-inch diameter pre-drilled holes. However, the
rear two holes did not line up with the existing
mounting bracket. To remedy this, two additional
0.25inch-diameter holes were drilled through the steel
frame of the seat. The seat was then attached to the
existing mounting bracket using four 0.25-inch diameter bolts. To attach the seatbelt to the new seat,
two, 3/8 inch-diameter holes were drilled through the
steel frame of the backrest. The seatbelt was attached
to the new seat using two, 3/8 inch-diameter bolts.
OPERATION AND EVALUATION OF THE
ADAPTED LAWNMOWER
The operation of the clutch lever arm assembly begins
when, using his or her right arm, the operator firmly
pushes forward on the lever arm of the assembly to
bring the mower to a full stop and to lock the clutch
into disengagement. Force is transmitted from the
Figure 17.12. Hand Clearance Between Lever Arms
Assembly Attached.
arm of the operator to the assembly lever arm. Federal
regulations require that the clutch assembly provide a
mechanical advantage for the operator. The maximum force needed to disengage the drive system (or
conversely, engage the brakes) should not be greater
than 50 pounds. It was found that the force that
needs to be supplied by the arm of the operator to the
assembly lever arm is approximately thirty pounds,
which is less than the maximum force allowed by the
federal regulations. From the assembly lever arm, the
force is transmitted through the bracket to the push
pull rod. The force is then transmitted along the
length of the push pull rod and applied to the clutch
pedal as a result of the two nuts pushing against the
front side of the aluminum angle.
To release the clutch pedal, the operator pushes in the
button at the top of the lever arm, releasing the springloaded locking system and slowly allows the clutch
pedal to travel back and engage the drive system. The
lever arm is forced back by the spring-loaded clutch
pedal. The force from the pedal is transmitted
through the angle on the pedal pushing against the
two front side nuts.
Each component was evaluated while simulating the
operation of the lawnmower by a person with paraplegia. This test was recorded on a standard VHS
video and included the following tasks:
•
Folding the arms;
•
Securing the operator with the seatbelt;
•
Checking clearance between the operator’s foot
and the clutch lever arm assembly;
•
Checking clearance between the mower deck
lever arm and clutch lever arm assembly;
•
Locking the clutch lever arm assembly to disengage the drive shaft;
•
Changing gears;
•
Releasing the clutch lever arm assembly to engage the drive shaft; and
•
Simulating normal stopping using the clutch
lever arm assembly and recording stopping
times.
The test adequately displayed the effectiveness of the
clutch level arm assembly and the new seat. The operator is provided ample body support, and the seatbelt effectively secures the operator to the seat. With
the clutch lever arm assembly attached, the operator
still has sufficient clearance to place his/her foot on
the footrest, as shown in Figure 17.11. Also, the
clutch lever arm assembly does not interfere with the
normal operation of the mower deck lever arm. Figure 17.12 shows the distance between the clutch lever
arm assembly and the mower deck lever arm. The
clutch lever arm assembly can be locked in the forward position, disengaging the drive shaft, as shown
in Figure 17.8. This allows the operator to use both
hands to change gears. Finally, using the clutch lever
arm assembly does not negatively affect the stopping
time. Stopping times using the clutch lever arm assembly were compared to stopping times using the
existing foot pedal and foot-activated stopping. The
stopping times for the two methods were almost
equivalent on average to 1 sec.
The total costs of the material were $240.00. The price
of the seat was $97.52, and the lever arm was purchased for $95.00. These costs do not include machining costs of cutting, drilling and welding.
DRINKING SYSTEM FOR PERSONS WITH
QUADRIPLEGIA
Designers: Kathleen Church, Scott Campbell, Jason Wendle, Hussain Madoh,
Toledo, Ohio, 43606
INTRODUCTION
The purpose of this project was to develop a system
that allows patients with quadriplegia to drink water
independently while in bed when no assistance is
available. The prototype can be mounted to any hospital bed. The unit includes an adjustable, flexible extension arm that ends with a mouthpiece. The arm is
welded to a sleeve into which a main support post
slides. Such a post is typically located near the head
of most hospital beds. Water bottles and a waterline
are also supported by this post. The prototype
mounted on a hospital bedpost is shown with the
arm extended in Figure 17.13 and with the arm partially retracted in Figure 17.14
SUMMARY OF IMPACT
Patients with quadriplegia have little or no control of
the body below the neck. This makes it impossible for
them to get a drink of water independently. Dehydration becomes a problem when such individuals are
without assistance.
Figure 17.13. Drinking Unit Mounted on a Hospital
Bedpost with Arm Extended.
Users are able to use this system and attain water by
adjusting the mouthpiece location using only neck
movement, provided the mouthpiece is placed by the
user's head. This design is also effective for patients
with limited use of one arm, as they do not need the
mouthpiece by their heads all the times.
Designs with and without motorized arms were considered. The motorized option was dismissed because of safety aspects. If a system failure were to occur, the user would be unable to move out of the path
Figure 17.14. Drinking Unit Mounted on a Hospital
Bedpost Post with Arm Partially Retracted.
of the arm and may suffer further injury. The prototype consists of three main parts: the main support
post, the water bottle, and the extension arm.
The main support post is typically made of 3/4-inch
stainless steel tubing and slides into a sleeve located
near the head of most hospital beds. The water bottle
is supported from the top of the post with a bottleholding gripper. The post also supports the excess
water line, necessary for height adjustment, with a
support hook, as shown in Figures 17.13 and 17.14.
Additionally, the main post supports the extension
arm by a 1-inch steel sleeve with two inline holes.
Hand retractable plungers that fit these holes are
used to adjust the position of the sleeve along the
post, setting the height of the arm at the desired location.
The water bottle contains a machined hard plastic
disc that seals its lower end. A quick disconnect
valve is threaded into this disc, allowing the bottle to
be easily removed for filling. Soft ¼-inch plastic tubing is used as water line and is attached to the lower
end of the disconnect. This water line is connected to
a check valve that prevents leakage. The check valve
is mounted at the end of the extension arm. The
mouthpiece is connected to the check valve and consists of a short 1/4-inch tubing. All non-plastic components that come in contact with water are made of
corrosion resistant material.
The extension arm is welded to the steel sleeve of the
main support post. The arm consists of four sections.
The first section is a stay-put flexible PVC coolant
hose (hard plastic tubing), 15 inches in length. The
check valve is attached to one end of this tubing,
while the other end is threaded into a 14-inch
stainless steel tube (OD = 0.75 inch, ID = 0.68 inch)
that represents the second section of the arm. The
flexible hard plastic tubing forming the first section of
the extension arm allows adjustment of the location of
the mouthpiece connected to the check valve. The
third section of the extension arm is made of an identical tube (14 inches in length) that is hinged to the
second section.
The fourth and last section of the extension arm is the
arm support truss and consists of two members, as
shown in Figures 17.13 and 17.14. The first member
is a 15-inch stainless steel tube hinged at one end to
the second section of the arm and welded at the opposite end to the post’s sleeve.
The second member of the arm support truss is
welded, at 30 degrees, to the first member. This member is also welded at its opposite end to the post’s
sleeve. Shoulder bolts, washers, lock nuts, and tubing
caps were employed at all hinges. Self-adhesive Velcro was used to hold the water line to the extension
arm.
Assistance is required to adjust the position of the extension arm on the hospital bedpost and for the removal, refilling, and reattachment of the bottle. Assistance is also required to position the mouthpiece for
patients with no arm movement. A sterilization solution should be processed through the system at least
once a week to ensure a clean water flow from the
mouthpiece. This piece should be thoroughly and
frequently washed.
On a mass production scale, the plastic disc that seals
the bottle would be more efficiently produced by a
casting operation instead of machining.
ASSISTIVE DEVICE TO START A PULL-START
LAWNMOWER
Designers: Chris Nikazy, Ryan Short, Yousef Dewaila, Aaron Lemieux
Toledo, Ohio, 43606
INTRODUCTION
The purpose of this project was to develop an assistive device that allows a person with a physical disability to independently start his pull-start lawn
mower. This person has weakness in his grip
strength and in his arms and shoulders. The device
includes a pulley that redirects a downward force assisted by gravity to an upward pulling force. The pulley is attached to a small metal frame housing wheels
that roll on top of one of the beams inside the client's
barn as shown in Figure 17.15. Starting the lawn
mower requires him to pull down on a handle bar attached to a rope that wraps around the pulley and attaches to the pull start handle of the lawn mower.
SUMMARY OF IMPACT
A unit was designed and built to allow a farmer with
a physical disability to independently start his pull
start lawn mower. This individual cannot control the
strength of his grip and cannot pull up on a cord with
adequate speed using his arms and/or shoulders.
The unit was safely tested and operated by the client
to his satisfaction.
This assistive device is used to redirect the typically
strenuous upward pulling force to a simple downward force that is assisted by gravity. The initial design consisted of a large frame that would hold a pulley approximately eight feet above the top of the lawn
mower. This frame was also to restrict the body of the
lawn mower to keep it from lifting off the ground
when the cord was pulled upward. However, it was
Figure 17.15. Assistive Lawn Mower Starter.
decided to use the client's existing barn as the frame,
which reduced costs.
Figure 17.16 shows a close-up of the prototype. It includes a pulley attached to a small metal frame that
houses wheels that roll on top of a single beam in the
ceiling of the client's barn. The frame is made of 0.25
inch steel plates. It consists of two vertical plates, 2
inches apart, welded to a horizontal rectangular plate
(2.5 inches x 7.5 inches). The two vertical plates were
not rectangular in shape, each plate having a total
height of 14.25 inches and a total width of 7.5 inches.
for rope attachment. A 0.25 inch rope was used. The
rope was attached to the handle, passed around the
A sheave (pulley for small diameter wires and/or fibrous ropes) rated at 1400 lbs. was used. The pulley
had a bronze bushing and an outside diameter of five
inches. The pulley was secured between the vertical
plates using two pulley spacers, each being an ultrahigh molecular weight polyethylene (UHMWP) rod,
1.25 inches in diameter and 0.625inches in length.
Each pulley spacer was drilled through to allow the
insertion of a 0.75inch-diameter drill rod that was
two inches in length (which was equal to the separation distance between the two vertical plates). Each
end of the drill rod was drilled creating 3/8inchdiameter holes. The two pulley spacers and the
sandwiched sheave were mounted on the drill rod,
which was attached to the two vertical plates of the
unit frame using 3/8-inch shoulder screws.
Four solid rubber wheels with hard tread and selflubrication were used to allow the steel frame to roll
on top of a single ceiling beam in the barn. Each rubber wheel was two inches in diameter and 15/16 inch
in width. Each rubber wheel was secured between
the two vertical plates of the steel frame using two
spacers of UHMWP rod, 0.625 inch in diameter and
0.5 inch in length. Each rubber wheel spacer was
drilled through to allow the insertion of 0.25 inchdiameter socket-head shoulder screws. Each of the
four sets of three rubber wheel spacers was thus
mounted on a 0.25-inch diameter screw that attached
the unit to the vertical plates of the frame. The solid
rubber wheels, the sheave, and the UHMWP were ordered from McMaster-Carr Supply Company.
A one-inch diameter, 10-inch long aluminum rod was
used as a handle; this allowed two hands to fit on the
rod as shown in Figure 17.15. A 0.312 inch through
hole was drilled in the middle of the handle to allow
Figure 17.16. Pulley and Rollers.
pulley, and then connected to the lawnmower's pulling cord using a hook.
The prototype was assembled and tested successfully
at the client’s barn under the supervision of his physician. The total material cost was $80.00.
ASSISTIVE DEVICE TO OPEN AND CLOSE
LARGE JARS
Designers: Aaron Lemieux, Andy Laker, Mohammad Al-Nasser, Yaser Jamal,
Client Coordinator: Dr. Greg Nemunaitis
Toledo, Ohio, 43606
INTRODUCTION
An assistive device was developed to allow a person
with a physical disability independently to open and
close jars of various sizes. The prototype consists of a
strap wrench with a handle machined to allow it to
slide into a metal block welded to a metal base, as
shown in Figure 17.17. The base is bolted to a tabletop for support. During operation, the handle slides
into the block and opens jars, as shown in Figure
17.18. When the handle is turned around and inserted in the block in the opposite direction, it closes
jars. Using the strap as the clamping mechanism allows the prototype to be used on jars of different sizes,
regardless of height or diameter.
SUMMARY OF IMPACT
Figure 17.17. Assistive Device to Open and Close
Jars.
The client, a farmer, had lost sensation in his fingers
due to a spinal cord injury. This device will assist
him in canning produce grown in his garden or provided to him by neighbors, as is the custom where he
resides. The device is universal in that any person
with a weakened or atrophied upper body may find it
useful.
The tightening/removal torques of commonly encountered jars were determined by consulting with
Owens-Brockway research and development laboratory in Perrysburg, Ohio. Two items were picked at
random from a grocery store: a salsa jar and a pickle
jar. At Owens' laboratory, the jars were tested in a
torque tester consisting of a steel jaw that gripped the
base of the jar. The jaw was connected to a torque
gauge that read both tightening and removal torques.
Figure 17.18. Device in Use by Client.
Torque was applied directly to the lid, as one would
when opening a jar. For both jars, the average tightening torque was measured as 75 in-lbs. The average
removal torques was 40 in-lbs. and 49 in-lbs. for the
salsa and pickle jars, respectively. These results were
consistent with the commonly used design guidelines
indicating that the tightening torque is related to the
diameter of the lid. A 70 in-lbs. torque is required to
tighten a 70-mm metal lid. Conversely, it takes only
2/3 of the tightening torque to remove the lid; that is
46.7 in-lbs. to remove a 70-mm lid.
A survey of the heights of typical grocery store jars
was then conducted to determine the height of the
smallest typical jars that could be encountered. This
was to determine whether the device needed a variable height adjustment to accommodate large and
small jars. Based on 24 samples, it was found that
common jars have an average height of 6.2 inches (±
1.4 in.) with a minimum height of 3.9 inches and a
maximum height of 10.4 inches. Using these data, it
was determined that only one height was needed to
clamp all the jars surveyed.
The jar-clamping device consists of a Ridgid brand
strap wrench manufactured by Ridge Tool Company,
Elyria, Ohio. A steel block with a 3 x 3-inch base and
4-inch height, was used to support the wrench. The
handle of the wrench was machined to enable the can
to slide into the steel block.
Because it was difficult to drill a hole through the
steel block that allows the machined handle to slide
into it, the block was divided into two equal small
blocks, each with a height of two inches. Each of
these small blocks was then machined such that
when attached together, a through hole was created
with a cross-section matching that of the machined
handle.
Once the handle was inserted between the two small
blocks, they were secured together using two 0.375inch bolts. The bottom small block was welded to a
steel base plate that was bolted to a tabletop using
four 0.25-inch bolts. The base plate was made from
0.25-inch steel and was square in shape (16 x 16
inches). Figure 17.17 shows a picture of the unit.
Figure 17.18 shows a schematic illustrating the machining details of the two small blocks.
During operation, the strap of the wrench is tightened
around the jar, generating a friction force that inhibits
jar movement. To open a jar, it is placed within the
strap with its bottom resting on the base plate. Pulling the loose end of the strap causes the strap to be
pulled tightly around the jar. With the jar in the
strap, the user places his hand on the lid and turns it,
making the strap tighten further and causing the lid
to be removed.
The device is also used to close jars when the handle
is removed, turned around, and inserted between the
two small blocks in the opposite direction.
The total cost of the unit including machining, parts,
and dissemination material, was $180.00.
Minimum thickness .940
.375 x 2 Bolts
R1.50 (optional)
Match uniform thickness
4.000
.385
.250
2.125
3.000
16.000
Figure 17.19. Schematic Showing the Machining of the Fixation Blocks Allowing Insertion of the Machined Handle
(Dimensions in Inches).
REACHER DEVICE
Designers: Kurt Hilvers, Jody Claypool, Andy Olszewski, Ahmad Al-Abdulrazzag,
Toledo, Ohio, 43606
INTRODUCTION
A heavy-duty reaching device was designed to allow
persons with paraplegia or people with limited reaching capabilities to grasp an object from 6-8 inches in
diameter and up to 25 pounds in weight. The unit
consists of a hollow aluminum shaft, a nylon cable
noose, a ratcheting lock grip handle, and two lock releases, one at the handle and one at the noose end.
The reacher extends 5.5 feet away. Figures 17.20 and
17.21 show the device being used by an individual
with paraplegia in his garage.
SUMMARY OF IMPACT
A device was designed and built to allow an active
person with paraplegia to reach and grasp heavy and
large objects independently. Previously, his means of
obtaining those objects was to knock them off the
shelf with a rake, which was impractical and dangerous. The reacher prototype allows him to reach those
objects in a more convenient and safe manner. Many
people have difficulty reaching up to a cabinet, or
picking an item up off a shelf. Currently, the available selection of reachers on the market is limited to
those for grasping small, light objects from a short
reach. The most common design in the market supports objects up to 4 pounds and widths of up to 4.5
inches. This reacher supports objects that are up to
25 pounds and has an adjustable noose capable of
carrying objects 2 to 10 inches in diameter with an extended reach of 5.5 feet.
Figure 17.20. Reacher in Use.
Several design concepts were considered including
jaw, telescoping, reel, and noose designs. Criteria included that the unit be lightweight, stable, safe, and
easy to use. The noose design was found to be most
Figure 17.21. Reacher in Use.
versatile. It better accommodates the needs of a
greater number of consumers due to its better grasping ability.
The noose consists of a 12-foot long cable, which
wraps around any object being picked up. The cable
tightens around the object, locking into position once
it has secured a specific tightness. The shaft of the
reacher is made of aluminum 3003, providing enough
stability not to bend once the object has been removed
from the floor or the shelf. The shaft has an OD of 1.5
inches and a thickness of 0.065 inch. Its length was
predetermined to be 5.5 feet long, to provide the greatest amount of benefit for household use. Once tightened, the ratcheting lock-grip handle, which remains
tight. This allows the user’s hands to remain free
when they are retrieving the object from the noose
end. The lock-grip design incorporates two releases.
The first release is by the handle, which makes releasing an object from a distance easier. Also, this facilitates placing an object on a shelf and changing from
one object to another. The second release is at the
noose end. This release allows the users to get the object once it has been lowered in front of them. A quick
grip bar clamp from the American Tool Company,
shown in Figure 17.22, was modified to make the
handle and trigger assembly. The clamping ends
were removed. The upper surface of the grip was
milled down. The clamping part was inverted on its
shaft, as shown in Figure 17.23. The shaft required
machining. A hole was cut for the lock-grip handle to
be inserted, and holes were tapped into the shaft for
screws to secure the handle. A V-shaped rubber stop
assembly was also mounted to the shaft at its grasping end. This portion was added to the shaft to support objects while they are gripped.
The handle operates on a sliding rod mechanism.
The rod, which extends a distance of 12 inches from
the back of the handle, slides through the top of the
handle. As the handle is compressed, two metal
strips that lie flat with the handle are tilted at an angle. Simultaneously, the strips grab the rod and pull
it. The end of the rod in front of the handle is welded
to a disk that slides along the diameter of the shaft.
The disk, which is located in between the handle and
the noose, is attached to the cable with lynch nuts.
The other end of the rod is bent upward, perpendicu-
Figure 17.22. Quick Grip Bar Clamp.
.
Figure 17.23. Quick Grip Bar Clamp After Modification
lar to the shaft. This bent portion acts as a handle to
adjust the noose when it has not been secured.
The prototype was tested and evaluated by a person
with paraplegia, as shown in Figures 17.20 and
17.21, under the supervision of his physician. Operating instructions were clearly explained to the client
before he attempted to use the device.
The client indicated he will use the device often and
that the reacher will be a tremendous aid to him.
Since some parts may become worn over time, it is
suggested that the cable and the bolt connecting the
rubber stopper assembly to the shaft be replaced after
an extended period of use. It is also noted that the
reacher's shaft is made of aluminum and will be become slippery if exposed to oil or water. The total cost
of parts was $70.34. With mass production, the
reacher's price would be almost half the cost of this
prototype. The rubber stopper assembly could be
molded into the shaft, which could be made of thinner aluminum or plastic composite.
WHEELCHAIR BICYCLE-TYPE ATTACHMENT
Designers: Brian Kremer, Chris Sneider, Maitham Taqi, Tran Nguyen, Muhaiman Ahmad, Mohamad Al-Kazimi,
Toledo, Ohio, 43606
INTRODUCTION
A bicycle-type attachment was designed for use by a
person with paraplegia in a wheelchair. The client
has normal control of his arms and upper body. The
objective was to allow him to use his arms to propel
himself by hand pedaling the attachment unit when it
is temporarily connected to his wheelchair. During
operation, the front wheels of the wheelchair are off
the ground, thus making the structure, composed of
the wheelchair and attachment unit, function as a tricycle. Operating this tricycle structure allows the patient to exercise different muscle groups in his arms.
SUMMARY OF IMPACT
This prototype was constructed for a person with
paraplegia who is very active and enjoys outdoor activities with his family. Persons with paraplegia confined to wheelchairs often have limited opportunities
to enjoy outdoor activities. Often, these patients cannot engage in public recreational activities because of
the cost and availability of appropriate sporting
equipment, such as racing wheelchairs. Using an affordable bicycle-type attachment unit that is easily
connected to a wheelchair transforms it readily to a
recreational hand pedaled tricycle.
A bicycle-type attachment unit was designed to satisfy the requirements that it have no permanent attachments to the wheelchair, allow the user to propel
himself using hand pedals, lift the small front wheels
of the wheelchair off the ground during operation,
and be safe, lightweight, and user-friendly, allowing
the user to attach and detach the unit independently.
Figure 17.24. Tricycle in Use by a Client with Quadriplegia.
Figure 17.25 shows the different parts of the attachment unit and its connections to the wheelchair. The
attachment unit incorporates a regular 24-inch bicycle wheel (not labeled in Figure. 17.25), a three-speed
coaster brake, a front wheel bicycle fork, a steering
arm, a crank-drive assembly (not la beled in Figure
17.25, but consisting of hand pedals, crank arms and
a drive sprocket), a drive chain (not shown in Figure
17.25) and a connecting frame made from one-inch
nominal steel tubing.
The front wheel bicycle fork has to be custom-fit to the
three-speed-coaster brake hub, which usually provides a rear wheel drive in most bicycles. The crank
drive assembly drives the chain, which drives the
three-speed-coaster brake that provides three forward
speeds and allows the user to decelerate by using a
reverse rotation motion of the drive sprocket.
The steering arm was welded to a headset that rotates
within the steering tube, causing the front wheel fork
7
8
12
11
15
16
8
Description of parts:
10
9
13
14
15
8
6
12
6 lower support structure to base plate
7 lower support structure to steering tube
8 upper support structure to steering tube
9 turnbuckle
10 steering arm
11 reinforcement of upper structure
12 reinforcement for upper and lower support structures
13 headset going into steering tube
14 steering tube
15 front wheel fork
16 wheel hub (3-speed coaster brake)
7
Figure 17.25. Bicycle type attachment
to rotate also within the steering tube. A bracket was
attached to the headset to provide a guide for the
drive chain. Hence, the chain path is from the drive
sprocket to the guide bracket to the three-speed
coaster hub and back around to the drive sprocket.
This path was selected to allow the chain to avoid
contact with the fork and the connecting frame at all
times.
The design allows the attachment to be connected to
the wheelchair using clamps located on the connecting frame and secured to the wheelchair on each side
of its supporting frame, just below the patient’s knees.
These clamps were coated to prevent damage and/or
slippage while attached to the wheelchair. They also
have a cam-locking device to prevent them from becoming loose. Also, the design allows the front
wheels of the wheelchair to be supported by the attachment unit using two racks located on the bottom
part of the connecting frame. The two racks, made of
fourteen-gauge steel, were connected with a schedule
forty steel channel.
During the attachment process, the user rolls the front
wheels of his wheelchair into the two racks that provide a stop. He then secures the front wheels in place
by inserting a set of two pins in each rack. The user
then turns down two screwjacks, one attached to each
rack, to lift the racks housing the front wheels, producing a slight backward tilt of the wheelchair.
These hand-operated screwjacks allow for a clearance
up to two inches off the ground. The user then extends the upper part of the connecting frame using
two turnbuckles, thus allowing the clamps to be secured to the supporting frame of the wheelchair. Finally, the user turns up the screwjacks, converting the
attachment unit and the wheelchair into a tricycle
type structure.
Figure 17.24 shows the patient sitting in his wheelchair with the attachment unit connected. During final testing, the patient was able to steer and drive the
tricycle structure comfortably. It has been recommended to the patient to avoid high-speed turns to
prevent turning over, as he has limited control of his
torso movements. The patient indicated that while
connecting the attachment unit to the wheelchair,
turning down the screwjacks becomes difficult as the
ground resistance increases. Screwjacks can be replaced with pneumatic jacks, but this will compromise the simplicity of the design. Total expenses for
materials and supplies were $625.00 with the bicycle
wheel assembly (wheel and coaster brake) being the
most expensive item, costing $150.00.
TEMPERATURE CONTROL SHOWER UNIT
Designers: Ben Schaller, Christine Vance, Terry Baylis, Jason Grup, Seung-Jae Yi,
Supervising Professors: Dr. Mohamed Samir Hefzy and Dr. Nagi Naganathan
Toledo, Ohio, 43606
INTRODUCTION
The purpose of this project is to design and develop a
temperature controlled shower unit to be used by a
person with paraplegia who has little or no motor or
sensory function below his arms. The unit allows the
client to interactively select and set his preferred water temperature in the shower. The design of this unit
incorporates a thermal mixing valve that provides optimum temperature control, and a proportionalintegral-differential (PID) controller that ensures a
constant water temperature throughout usage. The
valve is operated by a motor, which permits mixing
cold and hot water within its body. A thermocouple
measures the temperature of the mixed water and
feeds it to the controller, which provides a feedback
input to the motor allowing valve rotation. An antiscald valve was also incorporated to prevent burns
caused by scalding hot water that may result from
system failure.
SUMMARY OF IMPACT
A loss of sensation puts individuals risk for unknowingly injuring themselves with scalding water. Persons with motor and sensory loss may need assistance to adjust the water to keep a constant temperature while washing, and while seated at the back of a
bathtub on a tub bench, using a long handled shower
head. With the use of a temperature controlled
shower unit mounted inside the shower’s walls, patients can independently determine water temperature and take a shower comfortably and safely.
The proposed design incorporates a thermal mixing
valve that combines the output from hot and cold water supply lines into a single outlet stream having a
Figure 17.26. Temperature Control Shower Unit.
The System Includes: (1) Motor; (2) Mixing Valve, (3)
Thermocouple, (4) PID Controller, (5) Transformer,
(6) Hot Supply Line, (7) Cold Supply Line.
specified temperature. A unit composed of a PID
controller, a direct-coupled actuator, and a thermocouple, allows temperature control via an adjustable
mixing valve.
Due to the wet environment, it was necessary for the
control unit to operate at 24 volts and reduced amperage. This required using a transformer to step
down the power from the standard 110-volt service to
24 volts. The system and its components are shown
in Figure 17.26
The thermal mixing valve was designed to sustain up
to 75 psi of water pressure and to operate between 45
and 200 degrees Fahrenheit, which accounts for all
possible conditions present in a typical household
water system, whether it is supplied municipally or
by a well with a pump. For simplicity, the system
was designed to operate with a single motor where
hot and cold streams are mixed within the body of the
thermal valve. The valve is composed of body, stem,
three o-rings, and a stem-retaining nut. The stem is a
0.75inch-diameter rod with two 0.5-inch holes drilled
through perpendicular to each other and offset axially 1.5 inches. The effect of the offset of the holes is to
allow the motor to rotate the stem within the body of
the valve 90 degrees. This allows the mix of the two
inlet streams to vary from 100% cold flow to 100% hot
flow with adjustable mixtures of hot and cold between the extremes.
The stem diameter is reduced to 0.5-inches to allow
for a retaining nut to hold the stem in position inside
the valve body. The stem-retaining nut is made of
aluminum and has a 0.50-inch hole through the center to slide over the stem. The retaining nut is
threaded on the outside edge and threads into the
valve body to prevent the valve stem from moving in
the axial direction. Three nitrile o-rings (operating
temperature between -65 and 275 0F) were employed
to seal the opening where the stem exits the body of
the valve, thus requiring three o-ring grooves to be
machined into the valve stem. Two o-rings were used
to prevent water from leaking out along the valve
stem, and one o-ring to prevent leakage between the
hot and cold streams.
A Watlow Series 965 PID controller was employed to
regulate the temperature. The motor was selected to
allow for slow rotation, which was required to reduce
temperature fluctuation about the set point. A directcoupled actuator, manufactured by Honeywell, with
a stroke range of either 45o, 60o or 90o, was used. To
measure the temperature of the mixed water, a T- type
thermocouple with a working range of 32oF to 662oF
was selected. Flexible romex wiring and connectors
were employed in the final set-up. The thermocouple
measured the temperature of the mixed water, and fed
it to the controller, which subsequently compared it to
the set temperature, and acted accordingly. The controller caused the motor to turn in one direction or the
other, depending on whether more hot or more cold
water was required in order to match the measured
temperature with the set one.
A commercially available chrome plated brass antiscald valve was added to the system. Since this valve
is small, it can be installed at any point between the
gooseneck pipe and the hand held showerhead. The
valve is designed to automatically shut off the water
when the temperature reaches 114 ±5 oF. A red reset
button on the anti-scald valve can be pushed once the
showerhead is directed away from the body to flush
the hot water from the pipes.
The system was tested to determine the time required
to respond to a significant temperature change. Two
types of tests were conducted. In both tests, the valve
stem was oriented to 100% cold water flow, approximately 67oF. In the first test, the PID input temperature was set at 215oF. The system responded by rapidly adding hot water. In 90 seconds, the water was
shut off when it reached an average of 111.5 oF for two
trials, which was within the designated rating of
114 oF ± 5 oF. In the second test to demonstrate how the
PID controller determines the rate of temperature
change and prevents temperature overshooting, the
PID input temperature was set at 110oF. As the measured temperature approached the set temperature, the
rate of temperature change decreased. In about 90
seconds, the system stabilized with an average 2.15
seconds per degree over two trials.
The temperature control shower unit can be used
with a standard long handled showerhead while the
patient is seated on a tub bench at the back of the tub.
One limitation of this system is that the mixing valve
was designed to operate as a thermal-mixing valve
only; isolation or shutoff valves were not included in
the design of the prototype. The system can be improved if isolation valves are to be used for both hot
and cold supply lines to start and stop flow. Furthermore, some improvements could be achieved if
the 60° (instead of 90o) range of rotation of the motor
were selected and if the orientation of the holes in the
valve stem were altered. If the valve stem holes were
less than 90° apart, the mixture would change more
rapidly and would speed the response time of the entire system.
The total cost for materials and supplies was $500.
The controller and motor were the most expensive
items, costing $266.00 and $96.26, respectively.
CHAPTER 18
UTAH STATE UNIVERSITY
College of Education
Center for Persons with Disabilities
Logan, Utah
Frank Redd, Ph.D. (801) 797-1981
[email protected]
Marvin G. Fifield, Ph.D. (801) 797-1981
229
AUTOMATIC ROCKING BENCH SWING
Design Team: Shawn Hawk, Troy Kunzler
Client Coordinator: Mr. Rick Escobar, USU AT Development and Fabrication Laboratory
Supervising Professors: Dr. Beth Foley, CCC-SLP, Center for Persons with Disabilities
Ms. Amy Henningsen, OTR, Center for Persons with Disabilities
Utah State University
Logan, Utah 84322
INTRODUCTION
This project was designed for a young woman with
autism who had a history of engaging in selfinjurious or aggressive behavior when she was tired,
bored, or frustrated. Her parents reported one of the
few things that calm her during such episodes was to
rock her for long periods of time, either in a rocking
chair or on an outdoor porch swing.
This led to the development of an inexpensive automatic bench-type swing, in which the young woman
was able to rock herself independently. Making the
automatic swing mechanism safe and easy to use for
the consumer was an important consideration. Because she could use it independently, she was able to
engage in an enjoyable, self-selected leisure activity.
Her use of the swing provided the additional benefit
of some much-needed respite for her primary caregivers.
SUMMARY OF IMPACT
This automatic swing was developed to meet the
needs of one consumer and her family. However, the
swing is appropriate for use by children (age 3+) or
adults with a range of disabling conditions, who may
benefit from the sensory stimulation and relaxation
the swing can provide. Safety features include an adjustable seatbelt, a padded seat, an adjustable umbrella to limit sun exposure, a weather-safe motor enclosure, and an easily accessible switch for the caregiver.
The swing structure was made of 1.5" galvanized
pipe for long lasting outdoor use. The framing dimensions were made to hold a five-foot bench with
room bilaterally to eliminate the possibility of pinching hazards. The base is 4' x 7' with 8"x 8" steel pads
used for supporting the swing in a level manner.
16” steel drive rods were used to give the swing
added support in the desired location in the front
lawn of the consumer’s house. The height of the frame
structure is 6' 4" to accommodate the height needed
for the free-moving swing.
The swing attachment is made from a 5/8" swivel
with an internal bearing allowing free movement.
The 5' wooden bench seat is attached to the
1.25”metal pipe swing frame. The motor is a ½ hp
110-volt AC gear motor with 30 RPM. The motor attaches to the swing frame directly underneath the
center of the bench. The motor also attaches to a steel
base stemming from the lower steel frame work and is
positioned in a vertical position allowing the actuating arm to have unlimited lateral motion. The motor
frame and bench frame are attached by an actuating
arm with swivel couplers on both ends. The motor
and actuating arm are encased in a protective cover to
ensure safe operation.
Chapter 18: Utah State University 231
Figure 18.1. Automatic Rocking Bench Swing.
TRAILER-MOUNTED LIFT SYSTEM FOR
HORSEBACK RIDING
Design Team: Justin Smith, Jeramy Jenkins
Supervising Professors: Dr. Beth Foley, CCC-SLP, Center for Persons with Disabilities
Logan, Utah 84322
INTRODUCTION
Lifting a person from a wheelchair to a horse is no
easy task and the risk of injury to caregivers and consumers is considerable. The purpose of this project
was to design an affordable lift system that would
make the transfer from wheelchair to saddle easier
and safer, thus making horseback riding a more accessible recreational option for persons with disabilities.
SUMMARY OF IMPACT
There are many equestrian organizations for people
with disabilities in the United States. Few use lifts. A
local organization that provides recreational activities to its consumers with disabilities needed a lift
system that was mobile and inexpensive. After several meetings with the recreational department of this
organization, design criteria established were that the
lift system:
•
Provide a safe and easy means of lifting a person
from a wheelchair on a trailer bed to above the
horse’s back;
•
Be adjustable and have lifting range of up to 5
feet;
•
Easily pivot from the wheelchair position to the
horse mounting position; and
•
Be simple and cost-effective.
This project incorporated three major components, including a trailer, a wheelchair ramp, and the lift sys-
tem. The trailer was 8' x 10' and had a height of 20"
on its deck. Four adjustable stands were added at
each corner to ensure stability and to provide for a flat
surface when on uneven terrain. A wheelchair ramp
was added, providing easy access to the trailer bed,
easy removal, and storage on the trailer when transporting to a different site. The trailer and ramp were
available on the market at reasonable prices.
The lift system was built to provide the recreational
team a transfer method with substantial range and a
quiet, smooth transfer.
The lift system was built on a 2' square base made
from a 1/4" steel plate. A 44" x 2 1/4" steel pipe extended from the base, with three gussets providing
the rigid stand.
The lift mechanism was 6 feet tall and built from 1
3/4" steel pipe with a rounded plug at the bottom,
providing a smooth pivoting point.
The lift arm was built from a solid 1 1/4" shaft with a
20-degree bend to keep the angle of motion in a more
fixed position during lifting. The adjustable arm was
inserted into the 1 1/2" pipe connected to the upright
standing frame. The hydraulic cylinder was a standard piece of durable medical equipment, therefore
meeting safety standards.
Figure 18.2. Trailer Mounted Personal Lift Transfer System.
REMOTE-CONTROLLED MOTORIZED TOY
VEHICLE
Designer Team: Delmer Brower, Dominic Florin, Craig Peck
Supervising Professor: Dr. P. Thomas Blotter
Department of Mechanical and Aerospace Engineering
Logan, Utah 84322
INTRODUCTION
An inexpensive simple kit was developed to modify a
toy vehicle to be operated by remote control. It was
designed for a child with cerebral palsy. Toy vehicles
on the market need major modifications both for the
safety of the child and the addition of the remote control. The main modified components of this project
are as follows:
•
New safety harness
•
Better roll bar
•
Motor to control steering
•
Motor to control speed
•
Relay to control stop/start
The modified toy in shown in Figure 18.3.
SUMMARY OF IMPACT
The major goals included the following:
•
Safety for the child
•
Easy and inexpensive modifications for parents
•
Parent control of vehicle
•
Enjoyable interface for the child
A kit was designed to utilize a remote control to operate servomotors similar to a remote-controlled airplane. A safety harness and larger roll bar were
added to the vehicle. An additional modification was
made to enable the child to use the steering wheel
without interfering with control of the car.
The kit includes complete instructions and all necessary parts to accomplish the modification or information on where to obtain parts.
The modification involved converting a remote signal
to enable the parent to steer, start/stop, and change
speeds on the toy vehicle. Most remote devices (and
the one chosen for this project) come with two small
servomotors. Using mechanical switching, the gas
pedal and the gears are operated by one or both of
these servomotors.
Through preliminary tests, the torque required to turn
the car was determined to be 250-ounce-inches. The
size of the servomotor and its connection to the vehicle were designed accordingly. Utilizing a four bar
linkage, the rotation of the servomotor was transferred to the steering column.
For safety, the degrees of freedom on the steering column were limited to plus and minus 30 degrees. This
provided a large enough mechanical advantage to
overcome this high torque with a smaller servomotor.
To meet the needs of the child with limited motor control, a larger and more secure roll bar was added
along with a safety harness to provide the child with
needed support.
The final cost of the kit was approximately $270.
Figure 18.3. Remote-Controlled Motorized Toy Vehicle.
THE SIGHTSEER: ADAPTED OFF-ROAD VEHICLE
Design Team: Casey Jensen, Kevin Geddes, Jim Nightengale
Supervising Professors: Dr. Ralph Haycock, Manufacturing Engineering Advisor
Dr. Clair Batty, Mechanical Engineering Department Head
Logan, Utah 84322
INTRODUCTION
All-terrain vehicles (ATVs) are not designed for persons with disabilities to use safely. A prototype was
developed to allow an individual with limited use of
his limbs to operate safely an off-road vehicle.
SUMMARY OF IMPACT
The Sightseer is an off-road vehicle designed to be operated by a person with a disability or any individual
who would prefer a 4-wheel drive ATV with additional safety features such as a four-way seatbelt harness system, roll cage, and safe return steering. The
Sightseer vehicle is fully controllable by a person with
limited use of one hand. Further testing is needed to
determine whether a person with quadriplegia would
be able to operate the steering controls if a joystick
controller were provided.
Design criteria were that the Sightseer be:
•
Be accessible for entry of a person in a wheelchair;
•
Be safe and durable, with restraints and a roll bar
to protect the driver;
•
Be reliable, reducing the possibility of breakdown
so that the user would be stranded;
•
Have four-wheel drive;
•
Have simple controls and few complicated parts.
•
Have a top speed between 10 and 15 mph for
safety; and
•
Be designed to climb a 30-degree incline.
A 10 hp Briggs and Stratton gas engine was used to
power the Sightseer. Two hydraulic motors were
used to provide variable torque output and skid steer.
The steering was designed so that if the hand control
is released or centered, the vehicle will come to a stop.
The vehicle has an electric start and is run by two levers, which fit in one hand.
The vehicle is equipped with a harness over both
shoulders and a lap belt to hold the user in a comfortable, safe position. The seat is padded and has a high
back for upper trunk support. Four chains were utilized for the power and the steering, thereby enabling
the operator to return for assistance if one chain were
to break. Standard-sized ATV tires were used for easy
replacement. The chains and all other moving parts
are protected from accidental contact for safety.
A safety training session was planned and offered to
the user.
Figure 18.4. Off-Road Vehicle for a Person with a Disability.
CHILD’S JOYSTICK-CONTROLLED GO-CART
Designer: Justin Patton
Supervising Professors: Dr. Beth Foley, CCC-SLP
Ms. Amy Henningsen, OT
Logan, Utah 84322
INTRODUCTION
Many children with physical disabilities cannot easily operate standard motorized vehicles. Motorized
vehicles adapted for use with a joystick control cost
up to twenty times more than standard models.
The purpose of this project was to design a safe inexpensive joystick-controlled motorized go-cart for a 6year-old boy with motor impairment due to spina bifida. The child had a cart that had been adapted from
a standard type vehicle, but it was difficult for him to
operate, and the cart would not operate on the lawn
area around his house. Furthermore, the seating system on his cart did not provide him optimal support
and its long wheelbase resulted in poor maneuverability.
SUMMARY OF IMPACT
Many youths with a range of cognitive or motor impairments could utilize an affordable, attractive form
of independent mobility. There are several benefits
from using this type of device, including the development of visual and motor skills, increased social
activity, and outdoor recreational opportunities from
which children with disabilities are often excluded.
The go-cart fabricated for this project in corporated
many important safety features including a seat belt
system, a foam wrapped roll-bar, a free floating front
axle, and a low center of gravity.
The main objective of this project was to enable anyone, including persons with limited mechanical
skills, to construct a high quality, low cost, joystickcontrolled go-cart using recycled equipment. Most of
the basic components of the go-cart were taken from
motorized wheelchairs that had been discarded or
outgrown by their operators. Design requirements included a short wheelbase for good maneuverability, a
low center of gravity to compensate for the short
wheelbase, and a seating system that would provide
the operator with total support for his torso and legs.
The front wheels were extended 5", enabling the seat
to be positioned in a safe operable position. Chrome
rectangular tubing (3/4" x 1 1/2") was welded from
the lower battery frame to the front axle. A solid shaft
was fitted into the original frame pivot point and covered with a chrome pipe for aesthetic value.
A child-carrier seat from a bicycle was adapted to
provide added support to the user’s torso and legs.
Half-inch closed cell foam padding was used to cover
the seat, back, leg, and footrest areas.
The seat angle was set as the child sat in the cart
while accurate measurements were taken. A front
bumper was then added to give additional protection
to the child and the go-cart framework.
Because this go-cart may be constructed from parts
obtained from older motorized wheelchairs, which
are often available at a low cost, the total cost of a
similar project may range from only $200 to $500.
Figure 18.5. Child’s Joystick-Controlled Go-Cart
WHEELCHAIR DYNAMIC SEATING SYSTEM
Designer: Gary Malmgren
Supervising Professors: Dr. Beth Foley, CCC-SLP
Dr. Paul Wheeler
Electrical and Computer Engineering
Logan, Utah 84322
INTRODUCTION
Over two million Americans suffer from a debilitating
condition known as decubitus ulcers or pressure
sores. The sores occur as a result of prolonged pressure in the seating area. Individuals who use wheelchairs are susceptible to them, especially if they are
unable to make natural, manual shifts of their own
weight.
The goal of this project was to create a dynamic seating cushion to prevent pressure sores by alternating
the air pressure in the cushion. The seat is designed
to assist the natural shift of an individual, thus reducing pressure between the individual’s buttocks and
seating area, and facilitating blood flow through a
pulsing action of high versus low pressure. This
theoretically alleviates the problems of constant pressure experienced by individuals with limited movement utilizing wheelchairs. The completed prototype
will provide a platform for further investigation of the
project’s efficacy.
SUMMARY OF IMPACT
In the sitting behavior of persons without a disability,
there is frequent weight shifting from side to side and
from front to back, which occurs unconsciously. This
dynamic seating system would help one with a sig-
nificant motor impairment to simulate this natural
weight-shifting pattern. Automatically controlling
airflow throughout the cushion provides constant
changes in the seating position for the individual.
The programmable flow of air throughout the cushion
acts as a natural shifting process, which helps alleviate constant pressure on certain points on the buttocks most vulnerable to the development of pressure
sores.
To obtain a suitable design for this project, a dynamic
cushion, designed by Roho, Inc., that provides an individual with the lowest pressure differential between the cushion and the posterior of the user was
studies. Design specifications were then given to
Roho employees, who produced the prototype. The
new cushion has 90 separate air compartments in 9
different rows, divided in the middle of the cushion,
resulting in 18 different controlled rows.
A diagram showing the pneumatic plumbing of the
cushion is presented in Figure 18.6. A 12-volt pump
provides the air pressure needed. A micro-controller
controls the mechanical and electrical system.
1
2
3
4
5
6
7
8
9
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
Exhaust
Intake
Intake
Exhaust
1
2 3 4
Exhaust
5 6 7
8 9 10 11 12 13 14 15 16 17 18
Exhaust Manifold
S
Intake
Exhaust
Pressure
Sensors
1
S
2 3 4
5 6 7
8 9 10 11 12 13 14 15 16 17 18
Intake Manifold
Figure 18.6. Mechanical Diagram.
Intake
Exhaust
Rotary Vane
Pump
(Electric)
10
11
12
13
14
15
16
17
18
THREE-WHEELED HAND POWERED CYCLE
Design Team: William Ashworth, Shayler Backlund, Andrew Browning
Supervising Professor: Dr. P. T. Blotter
Mechanical Engineering Department,
Logan, Utah 84322
INTRODUCTION
A three-wheeled hand-powered cycle was designed
to provide riders who have motor impairments with
an affordable cycle that requires only the use of the
upper body.
SUMMARY OF IMPACT
Adapted cycles are typically unattractive, heavy, and
overprotective. A cycle was designed to be easy to
use, lightweight and fun. The design provides safe,
affordable recreational exercise to individuals with
paraplegia or other lower extremity disabilities.
The cycle utilizes a standard tricycle configuration, is
hand powered (cranked) with an internally geared,
chain-driven mechanism connected to the front wheel
and mounted directly in front of the rider. Steering is
controlled using the same crank mechanism that
powers the cycle. Braking is accomplished via front
wheel reverse cranking.
The frame consists of a triangular main section and a
rear suspension wishbone made of 6061 aluminum.
The frame is designed to support a rider weighing up
to 300 pounds under normal riding conditions. Notable frame components include a full seat in the recumbent position, standard bicycle headset, ergonomically correct hand cranks, and a rear shock absorber. Other designs are available on the market, but
Figure 18.7. Three-Wheeled Hand Powered Cycle.
are prohibitively expensive and do not include a suspension system.
To ensure safety, a chain guard was placed over the
drive system. This cranking system is designed to
collapse under the weight of the rider in the event of a
severe collision. A leg cross brace was provided for
maintaining leg positioning.
The down tube has padding to protect the rider from
leg bruises. The cycle also has reflectors. The use of a
helmet is strongly recommended for all users. A diagram of the design is shown in Figure 18.8.
Figure 18.8. Three-Wheeled Hand Powered Cycle.
DUAL ADAPTIVE RECUMBENT TRICYCLE
Design Team: Todd Lawton, Spencer Allen, Jason Eastman
Supervising Professor: Dr. P. T. Blotter
Logan, Utah 84322
INTRODUCTION
The Dual Adaptive Recumbent Tricycle (DART), a
three-wheeled tandem bike, was designed to provide
stable riding for two. The rear rider cranks with his
or her arms while the front rider steers and pedals.
SUMMARY OF IMPACT
The DART is a tricycle that allows two riders to travel
together. The rear rider may have any level of ability.
He or she may crank with his or her arms or just ride
along; he or she is not required to balance or control
the cycle.
This tricycle was built in a tadpole configuration,
with two front wheels providing the steering, and the
rear wheel providing the power. It was designed to
be recumbent, with full seats to support the riders and
provide greater comfort.
The frame and seat of the cycle were assembled from
6061-T6 aluminum with an expected life of 20 years.
To ensure continued usability, the cycle was constructed using as many standard bicycle components
as possible, including such items as brakes, wheels,
derailleurs, and cranks.
To ensure safety, guidelines from the American Society of Mechanical Engineers Human Power Vehicle
competition were followed, with exception of rollover
Figure 18.9. Dual Adaptive Recumbent Tricycle.
protection. This was considered to be unnecessary
because of the recreational, low-speed nature of the
project.
There are similar recumbent designs on the market.
However, their costs are prohibitive for the average
consumer. Also, current designs on the market do not
provide the person in the rear position the capability
of cranking with his or her arms.
Front View
of Steering
Mechanism
Figure 18.10. Dual Adaptive Recumbent Tricycle
CHAPTER 19
WAYNE STATE UNIVERSITY
Departments of Physical Medicine and Rehabilitation, and
Mechanical Engineering
261 Mack Blvd
Detroit MI 48201
Bertram N. Ezenwa, Ph.D. (313) 993-0649
[email protected]
247
WHEELCHAIR MOUNTING CLAMP FOR A
LAPTOP COMPUTER
Designer: George Gauchey and Robert Lambert
Supervisor: Dr. Bertram N. Ezenwa
Department of Physical Medicine and Rehabilitation, and Mechanical Engineering,
Wayne State University Detroit, MI 48201
INTRODUCTION
Computer clamps for persons who use laptop computers while seated in wheelchairs are generally designed for specific wheelchairs. Thus, when users replace their wheelchairs the cost of a new clamp may
be problematic. A laptop mounting device was designed for use on wheelchairs with rectangular seat
base support.
SUMMARY OF IMPACT
The client needed a sturdy, economic, and safe
method of mounting a laptop computer directly to a
wheelchair. The intent of this project is to design a
mount that will accommodate a multitude of wheelchair styles. The mount could also be used for attaching communication systems and other devices to
hospital beds or floor-mounted tables. This technology may be used in the home, office, and automobile
for attaching various items to chair frame structures.
Design requirements were that the device:
•
Be easy to manufacture;
•
Be interchangeable from powered to nonpowered chairs;
•
Be designed for chairs with rectangular tubing
frames;
•
•
Be easy to assemble;
Not require alteration of wheelchair seating
material;
•
Maintain computer positioning relative to the
client regardless of chair tilt;
•
Be manufactured from a lightweight, easy-tomachine material.
The design incorporated a wrap-around clamp fixture (see Figures 19.1 and 19.2). The wrap-around
was sectioned into a three-piece unit with a split top.
Figure 19.2 is a graphic representation of the clamping system.
The exploded view (Figure 19.2) indicates all components required to manufacture and to assemble the
clamping fixture. The fixture consists of a Jaw (1),
Plate (2), Jaw (3), Plate (4), and eight ¼ - 20 cap screws
of various lengths. Table 19.1 provides a breakdown
of component costs on a prototype run compared to a
batch run. The cost of the part when produced on a
large production run will be significantly less than
shown here. The costs shown are estimates for production. However, all materials and machining were
donated for this project.
Aluminum was selected for construction material because it is strong, ensuring safety and reliability, and
lightweight, so that it will not add excessive weight to
the chair. It is also easy to machine, which will help
maintain lower production costs. For this prototype,
conventional machining methods were used. In mass
production, components could be machined in batch
production, or basic shapes could be extruded or die
cast then, machined.
Chapter 12: Wayne State University 249
A static analysis of the system revealed a safety factor
of 23. Therefore, the chance of failure is remote. In
addition, the AL 5052 material chosen has a yield
strength of 27 kpsi and a tensile strength of 34 kpsi.
In all evaluations of the system, the maximum shear
stress theory was applied to determine failure and
safety factors. No changes in material were required.
System testing was performed by mounting the system to a stationary tube and by performing a pry
evaluation to determine if the device yielded or loosened. Pry evaluation consisted of applying an external load at the clamp mount surface. During testing,
no failures were observed.
Figure 19.1. Wheelchair Mounting Clamp for a Laptop Computer.
Table 19.1 Parts and Projected Costs for the Wheelchair Mounting Clamp for a Laptop Computer.
Part Number
1 Piece Production Run *
10 Piece Production Run *
Jaw (1)
$60
$30
Plate (2)
$20
$10
Jaw (3)
$40
$20
Plate (4)
$40
$20
¼ - 20 Cap Screw
$5
$5
Total
$165
$85
3
1
4
4
2
Figure 19.2. Diagram of the Wheelchair Mounting Clamp for a Laptop Computer.
ADJUSTABLE PLATFORM FOR AUGMENTATIVE
COMMUNICATION DEVICES
Designer: Jean Khalife and Todd Desantis
INTRODUCTION
Augmentative communication devices are useful
tools for persons with disabilities at work, leisure,
and school. The devices are normally situated in a
fixed location. In some cases, the operator may need
to be mobile while having access to them. The adjustable platform for augmentative communication devices made it possible for a person who has decreased
fine motor control due to cerebral palsy (CP) to continue his employment in an environment that requires
him to move his communication system from place to
place from his wheelchair.
SUMMARY OF IMPACT
This adjustable platform was designed to help a client with CP to easily and quickly move his augmentative communication devices from one workplace to
another. Ability to adjust the platform from 0 to 45°
allowed the client to use various types of augmentative communication systems, in cluding laptop computer-based types. The platform’s height and width
are adjustable to allow for use from wheelchair or
while standing. The platform is easy to use with a
quick setup time and can be disassembled to fit in
small areas for storage. The casters allow portability
with a simple anchoring system. All materials used
are recyclable and of high quality for increased life
and durability. The system will help the client or any
individual with CP to obtain and maintain employment.
Specifications were that the platform:
•
Allow the user adjust its height and the angle;
•
Support a variety of communication devices,
including laptop computers;
•
Support a variety of weights;
Figure 19.3. Photograph of the Adjustable Platform For Augmentative Communication Devices.
•
Be stable, with the ability to withstand offset
loading with minimal vibration;
•
Tilt up to a 45° angle to prevent light reflection
on the screen;
•
•
Be made of non-slip materials;
Enable the user to move from room to room
with devices attached;
•
Be easy to use and allow for quick assembly
and disassembly;
•
Be portable, allowing easy movement to different locations and floor types;
•
•
•
Be strong and durable;
Fit in a small area after being disassembled;
and
Be economical.
Design Description
Detailed drawings were generated using AUTOCAD
software. The design consists of a base that is made
from 2” x 2” steel tubes. One left and one right foot
extend telescopically from the body. The feet and central extensions are made from 1.75” perforated square
steel tubes. The platform is made from 3/4” particleboard Formica and is covered with a non-slip pad.
The platform is mounted on a “T” shaped structure
made from 2” x 2” steel tubes with hinges. All tubes
have 1/8” wall thickness. Adjustments can be made
in four different directions. The foot extensions telescope left and right to fit different sizes of wheelchairs, while the central extension moves vertically
for height adjustment. In addition to angle adjustment, the platform telescopes in and out to compensate for the difference in user sizes. The client required a tilting angle up to 45°. With the use of the
friction hinges, the angle exceeded 60°. The friction
hinges can support up to 45 lbs.
As mobility was of great concern, the system was
mounted on four rubber wheels. Two of the wheels
can twist at 360° and are equipped with strong
brakes. The two other wheels are straight to facilitate
steering, minimize drift, and increase stability. Pins
(7/16”) are used to hold the components in the desired position. Finally, the system was sprayed with
a heavy industrial paint coat to prevent rust and improve its appearance. The chosen color, antique
white, matches almost any furniture color.
Manufacturing and Assembly
After accomplishing the detailed drawings and completing the parts list, the system was constructed. The
square tubes were cut to the desired sizes at a 45° angle using an automatic hydraulic saw. Light filing
was necessary to eliminate the burrs and to allow
close alignment of the tube edges for proper welding.
The tubes were aligned and welded together according to the designed shapes. To obtain a smooth surface, a grinding process was necessary to even the
edges. Drilling for the holding pins and tapping for
the mounting hinges were the last machining processes. The system was then assembled and subjected
to a bench test to evaluate its function.
While the system was being painted, the wooden
platform was assembled. One stainless steel hinge
was used across the platform to achieve the tilting option. Two adjustable friction hinges hold it at the desired position. After all components were painted,
the wheels were mounted. Finally, the system was
evaluated.
Bench Test and Product Evaluation
Initial design evaluations revealed concerns with certain areas of the platform framework, which required
stiffening to reduce the possibility of vibrations during operation. Reinforcements were added to distribute the loading, thus eliminating the problem. After
assembly, one of the four casters was noted to be not
touching the ground. This misalignment was due to
welding affection. Components were heated and adjusted to minimize the offset. The casters were
brought to an acceptable planar to eliminate the problem. Heavy loads were placed on the end of the platform to simulate people leaning their partial or entire
weight on the platform. There was negligible deformation.
Ease of adjustment of the framework was an important concern. Filing and grinding were necessary in
some areas in order to improve telescoping smoothness. The last test included communication device retention to platform at maximum adjustment. Several
types of laptops and devices were placed on the surface while it was tilted to an angle of 60°. The devices
remained in place and no problems were exhibited.
It is estimated that the system will cost $492.85. However, area companies donated all the parts for the project.
MOUTH STICK DOCKING STATION
Designer: Tony D. Smith and Ibrahim A. AL-Homoudi
INTRODUCTION
Some patients with quadriplegia use a mouth stick to
change channels on their televisions. The mouth
stick requires a receptacle for storage when not in use.
The mouth stick docking station is a device used to
hold a mouth stick for a patient with quadriplegia.
The design is flexible, adjustable, comfortable, and reliable. It enables the patient easily to grasp and release the mouth stick.
SUMMARY OF IMPACT
The design is adjustable and easy to use, thereby freeing caregivers and enhancing the patient’s independence. The system is portable and adaptable for various bed units, as well. With the unit mounted to a
headboard, the patient still has freedom and space to
carry out other activities. The unit is easy to reposition for transferring patients in and out of bed.
The mouth stick docking station is made of machined
aluminum alloy attached to a flexible gooseneck. The
gooseneck is mounted to a hospital bed frame using a
triangular flange. The system is designed to prevent
the mouth stick from falling out of place after its release.
The choice of aluminum alloy enabled the reduction
of the amount of force applied while holding the
mouth stick. The system is illustrated in Figure 19.4.
Testing and Reliability:
Tests were conducted to verify the success rate of
adequately placing the mouth stick on the docking
station. Each result was compared against a wooden
docking station model with a success rate of 15 out of
20 attempts. The results of the tests indicated a success rate of 19 out of 20 trials. The increase in success
rate may be attributed to the wider v-shaped alumi-
Figure 19.4. Mouth stick Docking Station.
num prototype. Aluminum was chosen over wood
for manufacture because the use of a wider wooden
slot would jeopardize the structural integrity of the
docking station. Although the wooden docking station integrity could be improved through greater bulk,
increased mass may cause a large bending moment
on the flexible gooseneck.
Fixed
Attachment
Docking
Station
Gooseneck
Calculations for reducing the volume were made for
the surface areas V1, V2, and V3. Weight reduction
was achieved by machining off these materials. Three
areas of reduction were considered, the two corner
sections next to the taped hole and the bottom outer
corner, as seen in Figure 19.7.
The total cost of the project was $115.89.
Wooden Concept
Figure 19.5. Wood Concept for the Device.
Aluminum Concept
Figure 19.6. Aluminum Concept for the Device.
V1
V3
V2
LAPTOP COMPUTER CARRYING SYSTEM
Designer: Nail Azar, and Paul Jacovac
INTRODUCTION
This project was developed for an adult with cerebral
palsy who uses a laptop computer for communication. The patient is ambulatory and needed more mobility at his job. His augmentative communication
system must be available to him at all times. Therefore, a comfortable, ergonomically correct method for
the safe transport of his laptop computer without his
having to disassemble and place it in a carrying case
each time is optimal.
The device is positioned in front of the patient to enable him to see the monitor and access the keyboard
with his hands. Frequently, his job requires him to
guide two individuals with cognitive impairments
around the store by holding their hands. The working environment for his main activity has a tiled and
carpeted floor with a small step separating the two.
The aisles are large enough for adequate turn space.
SUMMARY OF IMPACT
This laptop computer carrying system enables the client to have his communication system at his disposal
at all times. The client can use it to safely transport
his laptop computer in an ergonomically correct way
to a variety of settings in his environment. The device
was designed to be in front of him, while still permitting the freedom his hands to do other necessary
operations. The design folds up well and is light
enough to transport easily.
Design considerations included that the device be
lightweight, safety, compact size, height adjustability,
ease of assembly and disassembly, ease of rolling rigidity, and static stability. The design consisted of
crevices rather than pins for the main body. Support
was added, as well as a wedge for mobility along
with a twist key for simplicity. These criteria were
taken and combined into a package that would fold
up easily.
The material used was “off the shelf” lightweight
aluminum. The two cross members on the base were
for rigidity and a foundation for the support and
main shaft. The targeted total weight was less than
20 pounds. The final product weighed 17.5 pounds.
This design was viewed using CATIA, and further
analysis showed that it was both statically and dynamically rigid.
Performance Evaluation
After completion, the system was assembled and disassembled repeatedly to ensure capability, repeatability, and ease of assembly. The device was rolled over
concrete, carpeted floors, and tiled floors to guarantee
dynamic rigidity and stability.
Tests revealed design specifications were met and satisfied the client’s needs.
Cost Analysis
Description
Cost
Swivel Wheels 2” 51mm
$14.36
4” Heavy Duty Strap Hinge
$1.87
1” Narrow Non Removable
Hinge
$1.53
Light “T” Hinge
$1.47
1/8”X1/2”X4’
Angle
Aluminum
$9.97
1/8”X1/2”X8’
Angle
Aluminum
$19.85
1”X1/16”X48” Aluminum
Square
Square
1”X3/4”X4’
Square
Aluminum
$15.47
The estimated material cost of the project was $72.82
1/8”X36” Rod
$1.47
Total
$72.82
Figure 19.8. Laptop Computer Carrying System.
LOWER EXTREMITY EXERCISE SYSTEM
Designer: Aaron Adams, and Tracey Matlock
INTRODUCTION
The purpose of this project was to build a device to
stimulate the lower extremities of a patient who had a
stroke. The caregiver requested mechanical stimulation to weakened motor joints.
SUMMARY OF IMPACT
The patient regained function on both sides. It is anticipated others could benefit from this mode of accelerating stroke recovery.
Various options were considered, including revising
an existing massage system, such as, the “Foot Fixer”
or the type of pad used on a chair. However, the system inputs could not be controlled and the inputs
were not repeatable. The decision was to design a system with controllable frequency and vertical pitch on
which the patient’s feet rest. By pulsating the patient’s feet with vertical amplitude at variable frequency, pulses from the instrumentation transmit
through the motor joints.
The original design called for a stationary platform
on a set of turning rods instrumented with small
bumps to make contact with the platform. During operation, these bumps would transmit pulses to the
platform, which would then be sensed by the patient’s feet.
To accommodate the demand for a robust system, the
design was converted to a camshaft like design. The
platform is made of metal. The design consists of two
shafts, four brackets, four rollers (disks), four roller
bearings, and two steel plates. As the shafts are timed
accordingly, inputs can be controlled.
A cam or roller had to be set 0.125 inch off center to
rotate about a shaft to enable the vibrating platform n
to move vertically with a pitch of 0.125 inch. Initially,
there were two shafts, 1.125 inches in diameter. The
Figure 19.9. Photograph of Lower Extremity Exercise System.
ends of the shafts were turned down to 1" to fit the
couplings for the cog gear. The vertical motion was
created by four simple rollers, 2.5 inches in diameter.
There was a hole drilled into the rollers to accommodate the shaft. The hole drilled was 1.125 inches and
was offset 0.125 inch from its center. The purpose of
this offset was to create the elliptical motion required
to obtain the vertical motion for the platform.
The four rollers were drilled and tapped along the
outer perimeter to enable them to be fastened to the
shafts. Also, these holes facilitated the indexing of
the rollers to ensure that they line up perfectly. To allow easy rotation, bearings were used. The four bearings were 1.125 inches in inner diameter, 1.5 inches
in outer diameter, and 0.5 inches thick. To support
the bearing and the rod, a bracket was fabricated. The
bracket began with 3.5 inch by 5 inch by .5-inch stock.
Then all four pieces of stock were simultaneously machined down on a milling machine. The brackets
were then drilled.
To ensure the four holes lined up perfectly, the brackets were again drilled and clamped together. The
parts were then assembled to check fit. The bearings
were not press fitted into the brackets. Instead, the
bearings were secured using setscrews. There were
two setscrews holding the bearings in place. To fasten
the brackets to the plate, the eight holes were first
drilled into the plate. Then the brackets were put in
place and marked for accurate hole locations. Next
the cog gears were added to one end of each shaft.
The cog was tapered to create a press fit when tightened with a screw to the coupling. The bracket-toplate hole locations were determined from the distance center to the center of the cog and the timing
belt. Once the locations were marked, the holes were
drilled and tapped.
Subsequently, the platform was ready to be fully assembled. First the roller was secured to the shafts, lining up all the holes. Then the bearings were placed
on the shaft about 9 inches apart. Once the bearings
were in place, the brackets were secured. The brackets were tightened to the bearings using setscrews.
Finally, there were two shaft assemblies. Again the
assemblies each consisted of the shaft, two bearings
located approximately 9 inches apart, and two brackets, which held the bearings in place. These assem-
blies were then secured to the plate using flat -head
screws. The mechanical displacement platform was
then mounted to the control system. The mechanical
platform was fabricated from donated materials. The
two shafts, the plate, and the four rollers were also
donated.
DRIVE MOTOR AND MOUNTING PLATFORM
The plywood used to support the system was standard ¾ inch. The platform has the dimensions of 18
inches by 32 inches and four industrial strength
wheels mounted at each corner. The motor was a 90volt Dayton ¾ HP motor with a Dayton variable
speed controller. The motor was wired for an input of
120V to enable use in household applications. The
patient or an caregiver can vary the 120V input to the
controller by changing the voltage going into the motor through a calibrated turning knob. The greater the
voltage, the faster the plate vibrates.
CHAPTER 20
WRIGHT STATE UNIVERSITY
Department of Biomedical and Human Factors Engineering
Dayton, Ohio 45435-0001
Chandler A. Phillips (937) 775-5044
[email protected]
David B. Reynolds (937) 775-5045
261
BILATERAL ACOUSTIC TRAINER
Student’s Names: Chad Bogan, Karen Fox, Michael Papp
Client Coordinator: Ms. Elaine Fouts
Gorman Elementary School
Supervising Professor: Dr. Chandler A. Phillips
Wright State University
INTRODUCTION
The Bilateral Acoustic Trainer is a keyboard redesigned to teach preschool children proper use of an instrument and to encourage bilateral movement in
children who tend to use only one hand. The children become more disciplined since they must properly play with the toy for the keyboard to respond to
their actions. Also, children with limited use of one
or both arms are more inclined to use the less dominant arm and hopefully increase dexterity in the
weaker arm. The instrument is also adaptable for
children with hearing impairments to enable them to
seek enjoyment from a musical instrument, as well.
SUMMARY OF IMPACT
The keyboard accommodates children who have limited use of only one of arm such that they are required
to use their non-dominant arm. It operates only when
the child is using both hands with feet properly
placed on the activation pad. In addition, it discourages children’s abuse of the keyboard. It automatically shuts off if being used improperly or if the child
Figure 20.1. Bilateral Acoustic Trainer.
steps off the floor pad.
The keyboard incorporates a switch, which allows
the child to use only one hand. The keyboard case
and keys were redesigned to withstand environmental stresses. The keyboard is functional for a variety of operators. It includes a visual display for
children with hearing impairments. An additional
switch, solely for the teacher, allows her to deactivate
the bilateral component of the keyboard for children
with use of only one arm.
The floor activation pad acts as a power supply
switch for the keyboard. The pad has an upper and
lower plate made of plywood. A metal plate is located in the center of the plywood plates, which may
be pressed together, causing the metal plates to make
contact, thus closing the switch. The no-spring floor
pad does not use springs, as it relies on the flexibility
of the upper plate to allow the metal plates to make
contact.
Chapter 20: Wright State University 263
Upper Conductive Plate
Spacer
Upper Platform
Triangular Strip
Lead Wires
Lower Platform
Lower Conductive Plate
.750
24.00
2.00
Figure 20.2. The No-Spring Floor Pad.
The anti-bang device was designed to deactivate the
system when the keyboard is struck with excessive
force. The teacher must reset it. This feature is controlled by a simple set of switches, which rely on a
linear spring to close a switch only when a preset
force (determined by the spring coefficient) has been
exceeded.
The keyboard is divided into fourths (as shown in
Figure 20.1), with two sections being distinguished by
green and two sections by orange. To satisfy the circuitry of the bilateral control, a key from each green
group has to be played simultaneously, or a key from
Piston
Spring
Upper Metallic Plate
Wires
Plastic Spacer Plate
Lower Metallic Plate
Figure 20.3. The Anti-Bang Switch Acting as a Force
Transducer.
both orange groups must be depressed simultaneously.
The logic behind the Bilateral Acoustic Trainer is
shown in Figure 20.4. The decade counter is used as
a toggle switch based on a signal being received from
the bilateral on/off button. The OR gate closes the relay when two like color keys are pressed, when buttons of different colors are pressed, or if the output of
the decade counter is high, indicating the bilateral
aspect of the keyboard has been deactivated. Figure
20.6 displays a portion of the existing keyboard,
which illustrates the modification of the existing keyboard circuitry necessary to detect when one or more
keys in a group is being pressed. This is equivalent
for a given color group of keys. The output increases
for each progressive key on the keyboard. In essence,
the pads, which are closed by a conductive plunger
when a key is pressed, are shorted together to ensure
current flow if any pad is closed. The diodes enable
the distinction between one key in a group being
played versus all the keys in the group being played
simultaneously.
5 Volts
To Speakers
1
2
3
Normally open Relay
that closes only
when final OR gate
goes high. Closing
allows signal to
Speakers
C
R
From Button
Detector
(high if button
depressed)
Grn. 1
Grn. 2
Orng. 1
From key
detection
circuits
Orng. 2
(Input high if key from
group depressed)
Figure 20.4. Logic of the Bilateral Control.
1
8
R
5V
Figure 20.5. Modification of Existing Keyboard.
A continuity checking circuit senses when a key or
This switch represents a
key or button or a
group of keys. The
circuit detects closure
of his switch
5V
22k
5V
22k
Figure 20.6. Continuity Checking Circuit to Sense when a Key is Pressed.
From key detection
circuit
(Input high when key
from certain color
group is pressed)
Quad Analog
Switch
(4016)
Transistor
switchws power
to the display
circuit
To Loght Display Circuit
Figure 20.7. Quad Analog Switch Used as a Buffer.
The transistor is necessary because the diodes drop
the voltage enough so the Schmidt trigger does not
trigger when placed at the high end of the first resistor. The capacitor provides a small amount of debouncing to the circuit. The diodes are necessary to
detect if only one key in a group is pressed, as shown
in Figure 20.5. Since the Schmidt trigger inverts, the
inverter supplies the entire detection circuit its desired output characteristic, namely high when a key
is pressed. Conversely, the opposite is true when the
desired output characteristic is low.
Figure 20.7 shows the quad analog switch in this circuit used as a buffer, as the hex inverters could not
provide sufficient current to completely activate the
switch. There are four of these circuits, one for each
group of keys. Since the input is high when a key is
pressed, the output is five volts to the circuitry controlling the visual display unit. The visual light display shown in Figure 20.1 consists of four groups of
lights corresponding to the four groups of keys.
When a key is depressed, the corresponding column
of lights is illuminated row by row, upward from the
bottom. When the key is released, the lights go out.
The cycle begins again when the key is pushed. The
circuitry for the light display is controlled by a 555
timer that sets the speed for the LED activation. A
decade counter is used in conjunction with the 555
timer to light them sequentially upward from the bottom. Transistors are used at the output of the decade
counter to increase the current to the LEDs, thereby
increasing their brightness.
The total cost of the project was $790.
ENVIRONMENTAL CONTROL UNIT
Designers: Jeff Demchak, Jill Leighner, Jill McCollough
Client Coordinator: Karen Harlow
Supervising Professor: Dr. Blair Rowley
INTRODUCTION
An environmental control unit was needed to allow a
person with severe cerebral palsy to control his surrounding environment. The user is a twenty-fouryear-old male with severe spastic cerebral palsy. He
uses a wheelchair. He is completely paralyzed, with
the exception of the ability to blink both eyes and rotate his head about .25 inches to either side. The client is unable to manually change the channel on his
television with a conventional remote due to his
paralysis. The client is nonverbal. Consequently, the
opportunity to choose or to express his desires has
never been available. This project design enables the
client to control his television set and two additional
electrical devices through the use of a cheek button.
SUMMARY OF IMPACT
This environmental control unit allows the operator
to actively participate in the surrounding environment and make his own choices, by controlling the
television as well as other electrical appliances. This
form of interaction with the environment increases
the communication level in his home. Having a
choice of the four options available to the user at a
particular time allows different items to be disabled
by the caregivers in case the device is used incorrectly
by the client. These options also allow the device to
meet the user’s needs in controlling only the options
desired or the options that may be handled by the
simple turning of a switch. With the built-in variable
sequencing rate, the product accommodates different
user reaction times. As the user becomes familiar
with the device, the rate may be increased. Likewise if
the condition of the user becomes more severe, the rate
may be decreased.
ON/OFF SWITCH
SPEED CONTROL
KNOB
MODE SWITCHES
RED
LEDS
Figure 20.8. Front view of the Environmental Control Unit
The unit consists of the following eight components:
display case, user button, AC/DC adapter, X-10
modules, X-10 remote, remote extender receiver, universal TV remote, and microprocessor. To operate the
unit, the user button and power must be placed into
the appropriate jacks; the remote extender receiver
must be directed at the TV; and the electrical appliances to be operated with the X-10 controls must be
turned on and plugged into the modules. The user
then determines one of 15 option modes by activating
the appropriate switches located above each of the
four pictured options. If the switch for a pictured option is activated, then that option is included in the
sequencing pattern for selection by the user. Next, the
unit is activated with the power switch located in the
upper left corner of the display case. The unit then
continuously cycles through the selected options, and
the operator depresses the button when the desired
option is available. The selected option is signaled by
the momentary lighting of an LED positioned above
each pictured option on the display case. When a
choice is activated, the cycle continues until another
option is selected.
A microprocessor is used for the basic control of this
project, specifically the BASIC Stamp II, which has 16
input/output pins. The first four input/output pins,
pins zero through three, are used as inputs to control
the modes option.
Any of the four possible options can be switched on
at any time. Each of the first four pins is connected to
a switch that connects the input pin to a high source
when switched to the on position.
The microprocessor program notices which of the
four switches are thrown or any combination of those
switches and activates output pins four through
seven, which are connected to LEDs on the display
menu, indicating a particular option to be available.
For instance, if switches A and C are thrown, the
LEDs above options A and C will toggle on and off
until a choice is made or until a different mode is activated, thus allowing the user to expand options. If
the user can handle only one option at a time, one
switch can be placed in the on position making only
that particular option available.
Pin eight is an input pin for an RC circuit. The resistance is varied by a potentiometer to form different RC
time constants measured by the microprocessor. This
potentiometer allows the user or the user’s caregivers
to vary the rate at which the options are being
scrolled through the menu display, thereby eliminating the problem of having a fixed rate. The potentiometer is available on the front of the display case,
and the rate can be adjusted by simply turning a
knob. The variability of rates is such that the slowest
is appropriate for first time users, while the fastest is
quick enough for an advanced user.
Pins nine through 12 are used to activate the TV
channel up, TV power, turn the first X-10 device on,
and activate the second X-10 device, respectively. Pin
13 is used to continuously monitor the user button
input. The remaining two pins, 14 and 15, are used to
deactivate the first and second X-10 devices.
The total cost of the project is $630.
ON/OFF
SWITCH
POWER INPUT
(AC/DC ADAPTER)
MODE
SWITCHES
TRANSISTORS
X-10 REMOTE
LAMP OFF
MICROPROCESSOR
SOUT
SIN
ATN
VSS
P0
P1
P2
P3
P4
P5
P6
P7
VIN
VSS
RES
VDD
P15
P14
P13
P12
P11
P10
P9
P8
X-10 REMOTE
RADIO OFF
X-10 REMOTE
LAMP ON
X-10 REMOTE
RADIO ON
X-10 REMOTE
TV POWER
X-10 REMOTE
CHANNEL UP
50K
POTENTIOMETER
BUTTON
INPUT
Figure 20.9. Wiring Diagram.
ADJUSTABLE CHAIR HEIGHT
Designers: James Marks, Kevin Spicer
Client Coordinator: Debbie Accurso
Supervising Professor: Dr. Ping He
INTRODUCTION
This adjustable chair height project was developed to
modify an existing wheelchair for a five-year-old
child with Arthrogryposis Multiplex Congenita, in volving fibrous stiffness of one or more joints. The
client remains in his wheelchair during the day. Previously, because of the fixed height of his wheelchair,
the child had to be transferred to another chair when
he wanted to work or play at various stations positioned throughout his classroom.
SUMMARY OF IMPACT
The adjustable chair lift raises and lowers the client’s
chair to variable heights to accommodate different
workstations throughout his classroom. The adjustable chair height project allows the child to interact in
a variety of situations with other children in the class.
TECHNICAL SUPPORT
The client’s wheelchair sits approximately 13 inches
off the ground. Some of the classroom workstations, a
sandbox and workbench, are at a height of 25 inches
off the ground, placing them out of the child’s reach
when he is in his wheelchair.
The adjustable height chair involves lifting the chair
manually with a screw jack, using a hand crank
placed on the back of the chair. The chair is mounted
to the top plate of the jack by two steel plates. The
base of the screw jack is mounted onto a steel plate.
The cylindrical base rails of the chair are replaced
with rectangular steel rails of the same length. The
steel base plate is then mounted on these new base
rails. The 90° drill attachment (RAD) is attached to
the base of the chair by a bracket. A steel adapter attaches the 90° drill attachment to the jack. Another
steel adapter attaches a universal joint to the opposite
end of the drill attachment. The universal joint is
Figure 20.10. Scissor Jack Design.
used to compensate for the drift experienced by the
jack. One end of a steel rod is attached to this universal joint. Another universal joint drill attachment system is then attached to the opposite end of the steel
rod. A steel adapter attaches the hand crank to the
90° drill attachment. This system, along with the
hand crank, is the gear mechanism used to rotate the
screw, resulting in a change of chair height.
The hand crank mechanism is attached to the back of
the chair by a slide-guide rail system. This system allows the position of the hand crank to remain constant as the chair moves vertically. The 90° attachment, RAD, is attached to the slide-rail system by a
bracket. Another steel plate is attached to the lower
part of the slide-rail system to add stability. The
slide-guide system is attached to the back of the chair
by a block made of ¾-inch plywood.
Two struts are used to help reduce the torque needed
to raise the chair and provide stability, reducing the
side-to-side motion of the chair. The struts are also
used as a safety measure to control the rate at which
the chair is lowered. These struts are attached to the
back legs of the chair and rail base by means of a balland-socket system.
Two steel rods serve as leg guides at the front of the
chair. One end of the rod is placed inside the leg. The
opposite end of the rod is attached to the rail base of
the chair by a nylon block. This block is designed to
allow lateral movement of the rod, compensating for
the drift experienced by the jack.
For mobility, four casters are placed at the ends of the
base rails. The two front casters are rigid, while the
back casters swivel to allow chair rotation. The back
casters have a lock system that is implemented when
the chair is raised or lowered.
A new footrest was made of ¾” plywood so the
child’s feet would not be left suspended from the
chair. Nylon bellows are attached to the front legs of
the chair, as well as around the shaft and universal
joints used in the hand crank mechanism, to prevent
children from getting pinched between the guides
and the legs of the chair as the chair is raised and
lowered.
Execution of the lift is basic. Once the chair is
wheeled to the desired table, pushing the tab at the
side of the back wheel to the down position locks the
back casters, making the chair ready to be raised.
Then the person places one hand on the back of the
chair to stabilize the person operating the crank and
then turning the crank clockwise until the chair is at
the desired height. The chair will remain in that position until the hand crank is used again.
To lower the chair to the original position, one hand
is placed on the back of the chair, once again for stabilization of the operator, and the crank is turned counterclockwise with the other hand. The crank is turned
until the chair stops moving. The chair is able to raise
and lower within a specified range. It has a minimum height of 13 inches, measured from the floor to
the bottom of the chair, allowing the chair to be used
for the lowest table in the room. The maximum height
attainable is 19 3/4 inches, again measured from the
floor to the bottom of the chair, allowing the chair to
be used with the highest table in the room, 25 inches.
The total cost of the project, excluding the donated
manufacturing costs, is $710.
Figure 20.11. Adjustable Height Chair.
MULTI-FUNCTION SPEECH THERAPY
APPARATUS
Designers: Jason Brookbank, Michael Eaton
Client Coordinator:
Supervising Professor: Dr. Ping He
INTRODUCTION
A multipurpose device was needed to aid speechlanguage pathologists (SLPs) in the treatment of patients with a variety of speech disorders. Speech
therapists often use Devices used by SLPs in clude
metronomes, tape recorders, volume indicators, and
delayed auditory feedback (DAF) systems. Tape recorders are used to record a sample of the patient’s
speech to examine and store for future use variables,
such as breathing rate and articulation. Although
standard tape recorders adequately serve this purpose, they require constant user interface to control
the record and playback of the sample, requiring the
therapist to expend therapy time rewinding and locating the sample on the tape. Solid-state recorders
such as those used in some answering machines address these problems, but can only record and playback finite read-write cycles.
Although there are commercially available devices
that measure volume levels, research revealed no
prior single self-contained device designed specifically for speech therapy that clearly displayed relative volume levels. Metronomes are commonplace
devices that produce a pulsatile sound at a variable
constant frequency. There are many types of metronomes on the market, but few, if any are designed
specifically for speech therapy.
SUMMARY OF IMPACT
This multipurpose device will assist SLPs in the
treatment of patients with speech disorders.
The Multi-function Speech Therapy Apparatus utilizes a microprocessor to ensure no degradation in the
sound quality regardless of the storage time. The met-
ronome used in this project is a simple 555 timer allowing for simple on/off switching and simple control rate. The microphone pre-amp in this design is a
simple transistor amp, which has the benefits of a
single power supply, few components, low power
consumption, and a desired built-in +2.5 volt offset.
A TDA7052 headphone driver chip is also included
in this design since it has the required bandwidth, the
power output ability needed, and a single potentiometer to control the volume. A LM3914 chip is specifically designed for driving a string of LED’s in the
desired manner. This chip takes a voltage input,
processes it with a comparator stack, and lights a corresponding LED based on the input voltage.
This device offers several functions including the
metronome, short delay, long delay, and visual feedback. The metronome function is controlled with the
metronome on/off switch and the metronome rate
knob. The purpose of the metronome is to help generate a fluid speech rate. The metronome is generated
from an audible pulse occurring at an interval set by
the delay control knob. The patient will usually say
one syllable per beat. Therefore, the delay ranges
from one to five beats per second.
The short delay function is controlled with the toggle
switch (short delay on/off) and rotary switch (short
delay length). The purpose of the short delay is to delay the speech of a person from 50 to 250 milliseconds. This delay period can reduce stuttering. The
delays are utilized therapeutically by starting the patient on the long delay and then gradually decreasing
the delay as speech improves.
The long delay function is controlled with the toggle
switch (long delay on/off) and optionally by the
manual Play/Record Control. The long delay can record 16 seconds of speech and play the sample back.
When the long delay mode is activated, it will check
to see if the manual control is attached. If the control
is not present, the MFSTA will automatically start recording a 16 second sample. When the buffer is full,
the MFSTA will wait approximately four seconds and
then play back the sample. Upon conclusion of the
playback, the unit will start to record again. If the
status of the short delay or long delay modes is
changed while the unit is recording or playing back,
the mechanism necessitates waiting for the unit to finish the playback before the change occurs.
The visual feedback device (VFD) is activated by the
power switch. The VFD has an arc of 10 LEDs, indicating the relative volume of the speaker. The indicator shows the volume of the speech the user is hearing
over the headphones. The LEDs are color- and position-coded such that green is ideal, yellow being close
and red being in the extreme. The left LEDs indicate
“too soft;” center is optimal; and right is “too loud.”
The threshold knob (calibration) adjusts the sensitivity of the VFD to represent different desired volumes.
This device is useful in any case where a second feedback source is desired.
The total cost of this project is $790.
Metronome rate
long delay ON/OFF
Headphone 1
Microphone
short delay ON/OFF
Headphone 2
System Power
short delay length
Volume
Metronome ON/OFF
Figure 20.12. Diagram of Controls.
AUTOMATIC JAR OPENER
Designers: Chong Kim, Rob Short
Client Coordinator: Ms. Donna Harlarcher
Fairborn Community Services
Supervising Professor: Dr. David Reynolds
INTRODUCTION
A device was designed to automatically open jars . It
was designed for a client with scleroderma, a form of
arthritis, which diminishes physical capabilities such
as gripping. In the process of opening a jar, one must
be able to stabilize the jar with enough grip strength
to counteract the torque necessary to unscrew the lid.
The three main objectives of this design include the
vertical mount subsystem, the grip/interface subsystem, and the torque input subsystem. The vertical
mount subsystem allows for vertical accommodation
of various jar sizes. The grip/interface subsystem
applies grip to hold various jar materials, provides
the necessary counter-torque, and accommodates
various jar diameters. Finally, the torque input subsystem applies grip to hold jar lids, provides the required torque, and accommodates various jar lid diameters.
SUMMARY OF IMPACT
Besides aiding those who suffer from scleroderma, an
automatic jar opener would be useful for others who
physically struggle to open a tightly sealed jar.
The motorized Open Up Jar Opener manufactured by
Appliance Science was the best match for the desired
specifications based upon ease of use and
manufacturing considerations. This pre-fabricated,
readily available, motor-driven unit was a logical
choice for use in a comprehensive design. Testing
indicates that the device provides ample torque and
the device provides ample torque and can accommodate a range of lid sizes. Because the device requires
a normal force and a gripping counter-torque, the remaining design considerations focused around
adapting this device to the client.
A normal force of at least 50 lbf, but not more than 100
lbf is considered ideal. Also, space specifications are
an important factor in the normal force generator. A
laboratory scissors jack was used because of space efficiency, fluid motion, and ease of use. The jar gripping system needs to be easily aligned under the cone
of the opener and consists of employing a high normal force and a friction-enhanced surface (rubber).
This system is integrated with the scissors jack by
coupling an adapted handle to the labjack power
screw.
To obtain enough clearance for this handle, the Open
Up is mounted to the labjack, which presses down
onto the fixed jar when the crank handle is turned.
Under the jar, silicone rubber (coupled with the normal force generated by the labjack) acts to secure the
jar. The ½-inch thick rubber mat also absorbs the excess normal force generated as a lid is unscrewed. A
1/8-inch-thick aluminum frame with a Plexiglas door
encloses the device. For additional safety, a double
strain gage force feedback system is implemented to
provide user feedback.
The total cost of this project is $890.
CRANK HANDLE
LAB JACK
LOCKING SWITCH
OPEN UP
MOTORIZED CONE
OPENING FOR POWER CORD
SECURED POWER CORD
ALUMINUM FRAME
FLEXIBLE POWER CORD
ZERO ADJUSTMENT
POWER FLIP SWITCH
HINGE FOR PLEXIGLASS DOOR
ELEVATION INSERT
FRICTION PAD
FORCE FEEDBACK
FORMICA BASE
Figure 20.13. Front View of Automatic Jar Opener.
DIGITAL DISPLAY
(MATTERY HOLDER IN
REAR OF UNIT)
RTA BUS ANNUNCIATOR SYSTEM FOR
PERSONS WITH VISUAL IMPAIRMENTS
Designers: Kimberly Clarkston, Bryan Jones, Tariq Sharif
Client Coordinator: Jim Fourcade
Miami Valley Regional Transit Authority
Supervising Professor: Dr. Thomas Hangartner
INTRODUCTION
This project was completed in conjunction with a regional transit authority (RTA). The purpose was to
increase the accessibility of public transportation for
people with visual impairments. These individuals
were assumed to be free of hearing impairment, such
that detection of audible signals was not a concern.
An audio annunciator system was installed in a bus
with a speaker located outside the bus near the door.
The announcement consists of the route number and
final destination of the bus. The system is activated
by the opening of the door and requires little effort by
the driver.
SUMMARY OF IMPACT
The current RTA buses have front and side signs to
display the route number and final destination of
each bus. Individuals with visual impairments have
a difficult time obtaining this information without assistance. Therefore, the implementation of an audio
annunciating system was critical.
The design of this system involved a microprocessor,
in which the voice recordings were stored on EPROM
accessed by a QuikVoice sound chip. The information is transferred to an amplifier and out through a
speaker. With the product being controlled by the bus
driver, the code entered for the signs accesses the necessary information to make the corresponding audio
announcement outside of the bus. The announcement is triggered when the door of the bus is opened.
The sound chip is the VP-1606, which allows messages to be recorded at sampling rates from 16K to
128K pbs. Increasing the sampling frequency increases the amount of memory required for a given
number of messages. For this project, the desired
sampling rate was 32K pbs. This chip also allows direct access to 64 messages recorded onto the EPROM.
For this prototype, only 10 messages were recorded.
Thus, only a single EPROM chip was required. After
the chips were programmed, the QuikVoice sound
chip was connected to the external EPROM chip.
The voice chip (VP-1606) was also directly connected
to the microprocessor (MC68HC11 E9). The unit was
then connected to the existing hardware, specifically
to the thumb-wheel/visual display used by the bus
driver.
The output of the unit was then connected to the amplifier, which was connected to the speaker. The activation switch for this unit is an internally connected
relay, also connected directly to the dome light voltage wire. When the front door opens, the voltage goes
high, closing the relay and activating the system.
The total cost of this system was $660.
CHAPTER 21
INDEX
555, 174, 175, 265, 270
555 Timer, 174, 175, 265, 270
Cerebral Palsy, 28, 51, 55, 64, 66, 86, 106, 188, 190,
191, 194, 202, 234, 252, 256, 266
Chair, 28, 29, 41, 43, 44, 55, 58, 66, 72, 73, 88, 89, 108,
109, 144, 164, 177, 188, 189, 190, 191, 195, 202, 230,
248, 258, 268, 269
Chassis, 5
Child, 36, 48, 56, 60, 70, 78, 82, 83, 84, 85, 118, 180,
184, 198, 200, 234, 238, 262, 268, 269
Children, x, 1, 36, 37, 41, 43, 44, 46, 47, 48, 49, 51, 56,
60, 61, 70, 74, 78, 82, 84, 86, 116, 118, 130, 156, 184,
198, 230, 238, 262, 268, 269
Clutch, 210, 211, 212, 213, 214, 215
Communication, x, 8, 9, 13, 132, 180, 194, 206, 248,
252, 253, 256, 266
Comparator, 270
Computer, vii, 4, 5, 8, 14, 37, 84, 86, 111, 112, 113, 114,
128, 139, 166, 197, 198, 200, 202, 204, 206, 240, 248,
252, 256, 261
Control, 14, 24, 30, 45, 50, 64, 72, 73, 78, 79, 83, 84, 85,
86, 88, 92, 97, 98, 100, 108, 109, 112, 113, 114, 118,
127, 130, 136, 138, 150, 154, 156, 158, 174, 175, 176,
177, 182, 192, 216, 218, 224, 225, 226, 227, 234, 236,
238, 244, 252, 259, 263, 266, 268, 270
Controller, 83, 226, 227, 236, 240, 259
Converters, 127, 138
A
Adjustable Table, 52
Alarm, 122, 123, 124
Amplifier, 82, 124, 127, 130, 136, 138, 274
Ankle, 158
Antenna, 124
Armrests, 164, 189, 213, 214
Arthritis, 154, 162, 272
Asthma, 168
Audio, 73, 84, 180, 274
AutoCad, 5, 7
AutoCAD, 5, 7
B
Backpack, 38, 118
Battery, 108, 109, 136, 137, 168, 174, 180, 238
Bed, 39, 50, 86, 87, 97, 124, 216, 232, 254
Bicycle, 32, 118, 119, 146, 198, 207, 224, 225, 238, 242,
244
Blind, 1, 6, 122, 177
Board, 1, 2, 7, 13, 17, 19, 42, 45, 48, 80, 82, 113, 114,
116, 122, 123, 124, 127, 136, 137, 138, 139, 194, 200,
202, 204
Book, 146
Brace, 30, 104, 150, 158, 170, 178, 242
Button, 29, 36, 64, 78, 79, 80, 92, 98, 113, 122, 177, 181,
184, 214, 227, 263, 266, 267
D
Database, 3, 8, 9
Decoder, 113, 137
Desk, 37, 53
Diode, 78, 126, 138, 174
DOS, 129
Driving, 137, 162, 270
C
CAD, 7
Camera, 126
Car, 43, 65, 80, 84, 85, 86, 148, 160, 234
Cart, 40, 118, 119, 198, 238
Cause-Effect, 2, 78
E
EPROM, 274
275
F
Feed, 86
Feedback, 3, 6, 7, 70, 84, 85, 130, 132, 136, 180, 192,
226, 270, 271, 272
Feeder, 86, 87
Fiberglass, 61, 66, 68, 142, 148
Foot, 32, 42, 55, 58, 128, 130, 158, 190, 202, 210, 211,
214, 215, 223, 230, 253, 258
G
Garage Door Opener, 177
Garbage, 156
Garden, 220
Gardening, 152
Gasoline, 162
Gear, 32, 58, 192, 210, 211, 214, 215, 230, 234, 258,
259, 268
Glove, 150, 162
H
Hand Brake, 65
Head Injury, 78
Head Rest, 44, 194
Head Switch, 45
Horseback Riding, 232
Hydraulic, 116, 117, 192, 211, 232, 236, 253
I
Incentive, 15
Infrared, 1, 72, 174, 194, 204, 206
Intercom, 138
Inverter, 175, 176, 265
K
Keyboard, 200, 256, 262, 263
Knee, 188, 190
L
Laser, 1
Laundry, 182
LCD, 82, 83
LED, 13, 72, 78, 79, 122, 124, 130, 137, 168, 230, 265,
266, 270
Leg, 32, 116, 158, 189, 190, 198, 210, 238, 242, 269
M
Magnet, 177
Microcontroller, 113, 126
Microphone, 113, 122, 133, 136, 137, 138, 139, 270
Microprocessor, 3, 7, 82, 83, 112, 136, 266, 267, 270,
274
Modulation, 124, 126, 138, 139
Motor, 32, 58, 78, 80, 94, 98, 106, 124, 150, 160, 177,
180, 184, 192, 200, 211, 226, 227, 230, 234, 236, 238,
240, 242, 252, 258, 259, 272
Mounting System, 195
N
NSF, ix, x, 1, 2, 3, 5, 10
O
Orthosis, 10, 24, 30, 31
Oscillator, 82, 124, 174
P
Photography, 6
Physical Therapy, 65
Plexiglas, 68, 86, 98, 123, 124, 154, 272
Plywood, 32, 37, 39, 45, 47, 49, 52, 55, 58, 61, 74, 128,
129, 148, 184, 259, 262, 268, 269
Polyethylene, 194, 219
Potentiometers, 130
Power Supply, 7, 37, 79, 124, 139, 177, 262, 270
Pressure Relief, 108
Pronation, 192
Prosthesis, 22, 23, 24, 130
Puff Switch, 174
Pulley, 195, 210, 211, 218, 219
PVC, 36, 39, 40, 46, 48, 49, 50, 52, 55, 56, 58, 65, 66, 68,
69, 73, 80, 88, 89, 116, 202, 204, 217
R
Radio, 72, 113, 122, 124
Radio Shack, 122
RAM, 136, 139
Reading, 82
Receiver, 1, 64, 112, 113, 114, 124, 138, 139, 174, 175,
176, 177, 266
Recreation, 65, 74, 92, 98, 118
Rehabilitation, vii, 2, 5, 6, 42, 52, 78, 108, 109, 112,
113, 114, 128, 158, 192, 247, 248, 252, 254, 256, 258
Relay, 64, 108, 109, 175, 176, 177, 234, 263, 274
Chapter 21: Index 277
Remote, 14, 72, 73, 97, 100, 104, 113, 114, 174, 176,
177, 180, 234, 248, 266
Remote Control, 72, 73, 97, 100, 113, 174, 176, 177, 234
RF, 113, 114
ROM, 6, 14, 32, 85, 86, 132, 139
S
Saddle, 232
Safety Factor, 108, 118, 188, 191, 248
Scanner, 7
Scanning, 180
Scooter Board, 48
Screwdriver, 164
Sensor, 126, 127, 130, 194, 204
Sensory Stimulation, 78, 80, 230
Shampoo, 154
Shower, 28, 29, 154, 188, 189, 190, 191, 226, 227
Showerhead, 154, 227
Ski, 28, 32, 188, 190
Ski Boot, 32
Soap, 154
Speech, vii, x, 1, 8, 9, 18, 113, 114, 116, 122, 132, 133,
136, 138, 180, 270, 271
Springs, 126, 158, 193, 262
Standing, 42, 52, 104, 129, 200, 232, 252
Steering, 56, 65, 160, 224, 234, 236, 242, 244, 253
Supination, 192
Support, x, 1, 6, 8, 9, 14, 29, 30, 32, 40, 41, 43, 44, 48,
54, 56, 60, 66, 69, 106, 107, 108, 116, 118, 144, 152,
153, 158, 162, 178, 189, 191, 192, 194, 200, 202, 204,
207, 210, 211, 213, 214, 215, 216, 217, 220, 221, 223,
230, 234, 236, 238, 242, 244, 248, 252, 253, 256, 258,
259
Swing, 74, 118, 180, 189, 204, 230
Switch, 45, 47, 73, 79, 97, 98, 100, 108, 109, 122, 124,
129, 156, 174, 176, 177, 180, 181, 195, 200, 230, 262,
263, 265, 266, 267, 270, 271, 274
T
Table, 37, 46, 52, 86, 98, 116, 117, 129, 170, 200, 202,
248, 269
Telephone, 1, 8, 177
Texas Instruments, 136, 138, 139
Thermocouple, 226, 227
Timer, 82, 83, 85, 108, 109, 127, 128, 156, 174, 175,
176, 265
Toilet, 190
Toy, 49, 78, 80, 82, 83, 184, 234, 262
Toys, 36, 49, 113, 184
Train, 84
Trainer, 262, 263
Training Wheels, 198
Transmission, 112, 138
Transmitter, 64, 112, 113, 114, 124, 138, 139, 174, 176
Transportation, 104, 274
Tricycle, 61, 224, 225, 242, 244
Tub, 226, 227
U
Utensil, 86, 170
V
Velcro, 31, 32, 45, 64, 86, 108, 152, 153, 154, 158, 204,
207, 217
Visual Impairment, 37, 122, 126, 274
Voice, x
Voice Synthesizer, 204
W
Walker, 37, 56, 106, 158
Wheel, 28, 54, 55, 56, 65, 89, 98, 106, 118, 160, 219,
224, 225, 234, 236, 242, 244, 269, 274
Wheelchair, 10, 28, 37, 50, 53, 54, 55, 64, 74, 84, 86, 88,
104, 105, 108, 114, 144, 146, 148, 164, 166, 182, 191,
204, 206, 210, 224, 225, 232, 236, 248, 252, 266, 268
Work Station, 53

NSF 1998 Senior Design Projects to Aid Persons with Disabilities

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