06 IE 546 S12 Proj 1 HT final report - Classes

Applying Human System Engineering to the design of a new physical
examination kit
Silvina de Brum, Hui Guo, Zhenqiang Su
IE546 (Spring 2012) - June, 6, 2012
Background
Dr. James Bauer, of Peace Harbor Hospital in Florence, Oregon, has conceived
the idea of the Healthcare Toolkit (HT), an integrated, multi-instrument system built
around a small tablet computer that utilizes these capabilities to meet the clinical needs.
The opportunity that Dr. Bauer recognized is the need for an examination
instrument subsystem. The HT will require a stethoscope, otoscope, ophthalmoscope,
thermometer, and dermatological camera for the capture of patient physical examination
data. With the advent of compact sensor technology, wireless networks, cellular coverage,
and cloud computing, a door has been opened for a vastly improved method of collecting
data from patients, examining them, and coming to appropriate diagnostic and treatment
decisions. This project builds on the work of previous OSU student projects that have
advanced the HT concept by investigating the opportunities presented by integrated
examination instrument subsystem.
The potential benefits of the EMR are promising. However, most of these benefits
have not been used, mainly because of EMR system has not yet been widely adopted by
physicians (Hu et al., 2002). This can be explained by several factors (Boonstra &
Broekhuis, 2010):1)High starting found, 2) physicians lack of computer skills (Ludwick,
2009), 3)time involved in selecting, implementing and learning and using the system
(Ludwick, 2009),4)Complexity and limitations of the systems,5) Fear of potential legal
consequences of adopting new technologies (Hu, 2002) and 6) interference with
physician routines and communication with the patients (Ilie, 2009).
There is a conflict between physicians’ desires and resources provided by EMR
system. Physicians need systems that are easy to learn, can be used efficiently without
interfering with their practice and provide benefits to them in their daily routine that are
worth investing time to learn them. EMRs are not yet designed to fit physician’s needs.
An EMR that fulfilled these needs should promote their use and therefore achieving all
the potential benefits that EMR can provide. Wireless technology has been widely used in
medical service, including WiFi, 3G or Bluetooth.(Lee, 2009). A new wireless
technology, ZigBee, has been suggested as its advantages over normal methods: Lowpower and reliable data transmission through ZigBee network nodes and Secure
transmission of medical data. A '3-tiered' architecture for vital data processing is a good
choice for collecting, transmitting, processing and receiving data (Aǧtas, 2008).
A new system that take advantages of existing technologies to provide different
ways to visualize, analyze and share patient data could improve medicine tremendously.
A deep understanding of the physicians characteristics, needs and desires is needed in
order to create a system that would be easily adapted by clinicians for their daily routine.
Objectives:
The objectives of this project are to apply the Human-Machine Systems
Engineering (HMSE) processes and principles to the development and the prototyping of
a physical examination kit subsystem as part of a comprehensive health care toolkit. This
kit intends to capture real time patient data, save it at the patient’s electronic health
records, eliminate data entry errors, and prevent the instruments from loss or damage.
The focus of this project will be to reduce the interference that sometimes, new
technologies provoke during the medical encounter and affect the physician's routine and
communication with the patient.
The system will take advantage of existing technologies such as compact sensor
technology, wireless networks, cellular coverage, and cloud computing, and then apply
their benefits to improve the physical examination, reduce data acquisition errors, and
maintain simplicity, ease of use and comfort of use.
IDEF0 Modeling
IDEF0 is a functional modeling language that facilitates the analysis of the tasks
at different levels of abstraction (NIST,1993). An IDEF0 model, was developed to
understand the physical examination, which is conducted to the patient during a medical
encounter. A0, the top-level diagram, explains the physical examination as a process in
which the physician assesses the state of the systems of a patient with the aid of certain
instruments (Figure number 1). The information gathered during the physical exam
contributes to the development of a working diagnosis, evaluate the state and evolution of
a certain conditions and confirm patient previous diagnoses. This process is controlled by
medical protocols, patient medical history, environmental and provider factors. A1 level
considers the process that this project will focus: heart, lungs, ears, eyes, and
dermatologic exam. During the evaluation of each system, the physician will use the
patient's symptoms and other information gathered during the interrogation to guide the
physical examination. The review of each system usually involve four tasks; inspection,
palpation, percussion and auscultation. Some examinations involve the four stages or
process and others just some of them. For example dermatologic examination just include
inspection and palpation and eye examination do not involve percussion or auscultation.
Most evaluations involve the identification characterization and categorization of
elements. For example, during the cardiac auscultation, the clinician identify heart sounds,
describe and characterize them and then categorize them.
The physical examination will provide additional information regarding the
patient condition, which will be considered to define a diagnosis and the state of the
patient. The physician will record his-her findings at the patient’s medical records.
Figure 1. IDEF0 model, A0 box
FMEA
Failure Mode and Effects Analysis (FMEA) is a method for systematically
analyzing what could go wrong in a prospective product or process, allowing
practitioners to prevent the potential failure. It involves rating each potential failure
across three dimensions: severity, probability of occurrence, and non-detectability.
An FMEA evaluation (Appendix 4) was developed based on the IDEF0 model by
considering events that could go wrong on each level of the model. We focus on potential
failure mode and errors might occur right now, or with a poorly designed HT. For
example, failing to correctly categorize a mole during a dermatologic exam could lead to
the misdiagnosis of a lethal tumor and have fatal consequences such as death. Knowing
what can go wrong allowed us to consider ways by which the system could prevent
mistakes, errors and mishaps.
Requirements development
Requirements for the HT1 prototype were revised and developed based on:
1. IDEF0 model,
2. FMEA developed for this system,
3. Literature review conducted for previous reports,
4. User centered principles,
5. Display design principles and
6. Existing standards
Requirements were continuously revised according to the updated IDEF0 model
and FMEA of this system and refined according to the human factor principles and
guidelines. Organization and categorization of the requirements were guided by the
model, proposed by Jordan in 1997, of practical benefits of the products. This model uses
a pyramid to describe how functionality (base), usability (middle) and pleasure (top) are
related to the practical benefits associated with products (Jordan, 1997). The
requirements developed provide a high level guidance with regards to:1) Features and
functionality that this system should provide. 2) Usability considerations and 3) Users’
emotional experiences when interacting with the device. The final requirements for the
HT1 prototype are listed in the Appendix 4.
Design
Requirements, IDEF0 and FMEA guided the design of the physical examination
kit. It consist of a wireless multifunctional sensing device and the user interface of an iOS
application. The device captures heart and lung sounds and images and video from the
eyes, ears and skin and the application allows the user to evaluate and modify the files
saved by the device at the patient medical history.
Multifunctional sensor:
The sensing device is a portable device. Its shape and dimensions adapt easily to
the hand characteristics so it can be easily handled and carried inside of a pocket. The
surface is smooth in order to prevent the colonization by bacteria and reduce the cross
infections between patients. Lights colors evidence the dirt and promote it cleanliness
(appendix 5 a).
The device communicates wirelessly with the electronic medical record that is
being used by the physicians iPad. The front side of the device presents the controls and
the back part the sensors. The device allow the clinician to perceive and record data to the
patient's file. It has five different modes of use, heart, lungs, eye, ear, and camera. Each
mode button present a light that indicates which mode is on (the one that has the light on
is the mode selected). After selecting the mode the user will use the desired instrument
function. The record button allows the user to record the data from the selected
instrument at the patient file.
iPad Application - User interface:
The application allows the user to revise, save or delete information from the
multifunctional sensor. It is designed to be part of an electronic medical records software,
at the physical examination section. The new functionalities were included at the digital
Encounter form at places close to the areas where the physician fills the information
related to the cardiovascular, lung, skin eyes and ears examination.
An static mockup was created using app cooker, an iPad prototype application.
The screens created were focused on the cardiac auscultation and serve as an example of
how all the instrument will interact with the patients records. After saving the patient
physical data, the user can compare it with databases of examples of normal or abnormal
situations, share it with other physicians seeking for advice, or review other examinations
in order to understand the patient condition. For a detailed description of the user
interface review appendix 5b.
Evaluation
We divide our participants into four groups considering two factors, experienced
versus novice on physical examination, be familiar with tablet computer or not. We will
give the participants a basic function overview of the system and also applicable objects
introduction, then conduct a role-playing simulation trials for testing and evaluating the
system as scenarios. The dependent variables will be speed which is the time to complete
an assigned task or to find the information needed and accuracy which is the number of
mistakes made by the tester. The testers will be asked to answer a set of questionnaires
after that. We will analysis the information be collected and useful feedback to improve
our design.
Future development and research
A physical mock up should be created to allow the proper testing of the system.
Completion of the design interface for all the instruments involved at the system should
be designed. After improving the system design with the testing result, functional
prototypes should be created, followed by testing to improve final details of the systems.
Project summary
During the development of this project, the team 1) successfully modeled the
physical examination process, 2) identified possible failures and create measures to
prevent them, 4) developed a series of requirements that would guide this system and
others, 5) develop a design concept based on the previous requirements and 6) developed
a plan strategy to test and improve this design. The process involved at this project
provided meaningful experience to the students at these Human-System Engineering
tools and methods.
Appendix 1 Operational Concept Statement
The system will capture, store and transmit real time data from a physical
examination and automatically save the information to the patient’s electronic health
record. The system will be portable and carried around by the physician. The
configuration of the system involves an iPad and a multifunctional device. The device
present basic controls that allows the user to record data from each system.
The appearance will be somehow similar to other devices used at the medical
centers. More important, the appearance should inform the user how the system should be
used (Maier, 2008) and promote it use by healthcare professionals. The system need to be
easy to clean, resistant to cleaning products, have a design with reduced joints or crevices
as well as smooth surfaces to prevent bacterial colonization.
The system will be used during the medical encounter, especially during the
physical examination. Physicians will collect real time data from lungs, heart and other
systems, evaluate it, and save it to the patient medical record. The physicians can send the
files to other experts seeking for advice when facing challenging diagnosis if it is
necessary. Information will be saved as audio, image or video files. The system will
provide aid to analyze these files to improve diagnosis and differentiation between
normal or abnormal sounds or images. The physician will decide if the multimedia files
will be recorded or not at the patient records - recording numerous files of normal
conditions would increase the storage space enormously.
The system will intend to prevent undesired consequences when the system is not
used as designed. For example, the iPad and the instruments should have a protective
case or be strong enough to resist accidental drops to the floor. Also, the system should
include an automatic turn off, or sleep mode, so the battery does not run off when the
device is left on but is not in use for a certain time. If it is possible, materials should be
resistant to cleaning products.
The system will include an iPad with the necessary software to interact with either
a multifunctional device and other instrument or with different set of wireless instruments.
The iPad needs to be able to connect wirelessly to the internet and to share information
via Bluetooth. The subsystem that captures the patient physical data needs to provide the
functionality of a stethoscope, otoscope, ophthalmoscope and a camera to take pictures
and video. This are the instruments most commonly used by the physician on a typical
encounter. A container to include all the elements of the system may also be part of the
system.
The interface should be adapted to the physician mental model and workflow. A
database software running on an iPad, operated via touch screen; should be activated to
perform its functions. The system should be easy to navigate and allow the user to enter
data using different mechanisms such as typing, writing or using voice recognition
software. The system may also provide access to different databases to allow the user to
compare the patient physical status with examples of normal and abnormal conditions.
For example, the physician could compare the patient heart sounds with a library of
normal and abnormal heart sounds to help him/her identify and diagnose a patient
condition. The software may provide information for users to guide them in the learning
of how to use this system.
The users of this system will be physicians, residents, interns, and also specialists.
The users will need to have basic computer skills and in the use of medical instruments,
the system may require typing skills. A short training will be provided to the user to
guide them through the system.
The system will be used at the places where a physical examination is conducted:
at the physicians’ offices, in wards where patients are hospitalised or in emergency rooms.
This system could also be used in rural environments. Environmental light will be needed
to distinguish the controls and used the device appropriately. Electrical power should be
provided to charge the batteries of the iPad and maybe the wireless instrument too. The
medical center should provide wireless internet to enable to system to communicate
among the different artifacts. The user should avoid the use of globes in order to interact
with the iPad touch screen.
The software should be able to store information temporarily when both WIFI and
Bluetooth are not available and transmit the information immediately when network is
available to the electronic health records. The system should prevent mistakes to occur
during the collection, analysis or storage of the record.
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Context
Medical protocols
Patient previous medical history
Environment factors
Provider factors
Doctor's initial hypothesis list
Ongoing patient-clinician relationship
Patient current status and physical data
Patient EMR/Encounter form
Patient existing conditions updated and categorized
Current status and physical data analysed
Conduct physical exam
Patient existing conditions
Updated patient EMR/Encounter form
A0
Practitioner
Equipment
Node:
C1
Title:
Physical exam
Number: Pg 1
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C6 C5 C4 C3 C2 C1
Ongoing patient-clinician relationship
Doctor's initial hypothesis list
Provider factors
Environment factors
Patient previous medical history
Medical protocols
I3
I2
I1
Patient existing conditions
Updated patient EMR/Encounter form
Patient EMR/Encounter form
Patient current status and physical data
Cardiologic status and data
Conduct
Cardiac
Examination
Current status and physical data analysed
Patient existing conditions updated and categorized
A1
Lung status and data
Conduct
Pulmonary
examination
A2
Skin, hair and nails characteristics
Conduct
Dermatologic
examination
A3
Eye characteristics
Conduct Eye
examination
A4
Ear characteristics
Conduct Ear
examination
A5
Conduct
other
examinations
A6
Practitioner
Equipment
M1 M2
Node:
C3
Title:
A0: Conduct physical exam
Number: Pg 2
O3
O2
O1
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C1 C2 C5 C4 C6 C3
Ongoing patient-clinician relationship
Doctor's initial hypothesis list
Patient previous medical history
Environment factors
Medical protocols
Provider factors
I3
I1
Cardiologic status and data
Current status and physical data analysed
Conduct cadiac
inspection
Patient existing conditions
Patient existing conditions updated and categorized
O2
O3
Inspection findings
A11
Conduct cardiac
palpation
Palpation findings
A12
Conduct cardiac
auscultation
Auscultation findings
A13
I2
Record findings at
patient medical
records Cardiovascular
section
Patient EMR/Encounter form
Updated patient EMR/Encounter form
A14
Patient
Practitioner
Equipment
M1 M2
Node:
C4
Title:
A1: Conduct Cardiac Examination
Number: Pg 3
O1
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Context
C6 C5 C4 C3 C2 C1
Provider factors
Medical protocols
Environment factors
Patient previous medical history
Doctor's initial hypothesis list
Ongoing patient-clinician relationship
I1
I2
Patient existing conditions
S1, S2, S3 identified
Cardiologic status and data
Identify heart sounds
Rythm and frequency identified
Presecence or abscence of murmurs identified
A131
Caracterize abnormal
sounds
A132
Auscultation findings
Categorize findings
O3
Current status and physical data analysed
O2
Patient existing conditions updated and c
O1
A133
Patient
Practitioner
Equipment
M2 M1 M3
Node:
C7
Title:
A13: Conduct cardiac auscultation
Number: Pg 4
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I1
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C1 C2 C6 C5 C3 C4
Ongoing patient-clinician relationship
Doctor's initial hypothesis list
Medical protocols
Patient previous medical history
Provider factors
Environment factors
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Lung status and data
Patient existing conditions
Context
Current status and physical data analysed
Conduct thorax
inspection
Patient existing conditions updated and categorized
O2
O3
Findings
A21
Conduct thorax
palpation
Findings
A22
Conduct thorax
percusion
Findings
A23
Conduct
pulmonary
auscultation
Findings
A24
I2
Record findings at
patient medical
records (Lung
examination
section)
Patient EMR/Encounter form
Updated patient EMR/Encounter form
A25
Patient
Practitioner
Equipment
M1 M2
Node:
C5
Title:
A2: Conduct Pulmonary examination
Number: Pg 5
O1
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Context
C5 C4 C3 C2 C1
Environment factors
Provider factors
Patient previous medical history
Medical protocols
Ongoing patient-clinician relationship
I1
Patient existing conditions
Insipiration and expiration sounds identified
Identify lung
sounds
I2
Lung status and data
A241
Description of intensity, pithc and location
Describe and
characterize sounds
A242
Current status and physical data analysed
O1
Categorize sounds
and findings
Findings
A243
Patient
Equipment
Practitioner
M2 M1 M3
Node:
C8
Title:
A24: Conduct pulmonary auscultation
Number: Pg 6
O2
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READER
DATE
Context
C1 C2 C6 C5 I3 C3 C4
Ongoing patient-clinician relationship
Doctor's initial hypothesis list
Medical protocols
Patient previous medical history
Patient existing conditions
Provider factors
Environment factors
I1
I2
Patient EMR/Encounter form
Current status and physical data analysed
Skin, hair and nails characteristics
Inspect skin, hair and
nails
Patient existing conditions updated and categorized
O2
O1
Findings
A31
Palpate skin, hair and
nails
Findings
A32
Record findings at patient
medical records - skin,
hair and nails section
Updated patient EMR/Encounter form
A33
Equipment
Practitioner
M2 M1
Node:
C6
Title:
A3: Conduct Dermatologic examination
Number: Pg 7
O3
A0 Conduct
Physical
Exam
A0 Conduct
Physical
Exam
5 4 100
Manufacturing
defects in the
instruments; use
as intended leads
to emotional stress
Risk of electric
shock, loss of
confidence in
provider
Pain on the
patient or loss
of confidence in
the provider's
competence
8
2 7 112
Manufacturing
defects in the
instruments; usage
lead to physical or
emotional stress
Risk of electric
shock,
cumulative
stress injuries,
or distraction
from other
tasks
Injury to the
clinician-user
8
2 5
80
5
3 2
30
Clinician must have Digital
A1 Conduct
3 Cardiovascul access to real time representation
ar
high quality audio
auscultation during the use of
sound acquiring
instrument (e.g.
stethoscopes).
Missed or
incorrect
of body sounds interpretation of
might mislead a auscultated
clinician used to body sounds;
analog
potential for
instruments
misdiagnosis or
inappropriate
treatment
RPN
Potential
Failure Mode
Power loss or
poor data
transfer
Design Requirements
5
Contributing
Factors
Insufficient battery
life of the
instruments
Potential Remediations
Nondetectability
Potential
Effects of
Failure Mode
Disruption of
the encounter
process
and potential
loss or
corruption of
Disruption of
the encounter
process and
potential loss or
corruption of
data
Severity
Activity /
Process /
A# Function
A0 Conduct
Physical
Exam
Probability
Appendix 3: Failure Mode and Effects Analysis
Fear of medical
Human beings Acquired data
A1 Conduct
3 Cardiovascul encounters, Patient react differently and information
ar
in pain,
auscultation Communication
barriers
Forgetting, not
A1 Conduct
Cardiovascul
considering it
3
2 3
18
Not giving
diagnose for a
possible
condition
4
6 6 144
The
system
should
provide
means to
guide the
physical
examinati
on and
prevent
omission
of tasks
Wrong
diagnosis
3
3 4
36
The
system
should
provide
means to
iad the
physician
to identify
and
caracteriz
e heart
sounds
Wrong
diagnosis
4
3 3
36 To check The
on medical
are biased and
examinations
wrong
and acquiring
data, which can
cause e.g.
higher heart
rate
Not examining
all the areas
ar
relevant,
auscultation interruptions
Inexperience of the Confuse a
A1 Conduct
Cardiovascul
doctor, small
normal sound
3
ar
lesions that are not
auscultation easily
identified,ambient
noise, status of the
physician(tired,
stress), top down
processes, not
auscultating all the
areas
3
with an
abnormal
sound and viceversa
Inexperience of the Wrongly
A1 Conduct
Cardiovascul
doctor, small
describe an
4
ar
lesions that are not abnormal
auscultation easily
sound
identified,ambient
noise, status of the
physician(tired,
stress), top down
processes
with the
experts
or check
for
similar
instances
in prior
reports
online
system
should
provide
means to
aid the
recognitin
and
caracteriz
ation of
heart
sounds
Inexperience of the Achieve a
Wrong
A1 Conduct
wrong diagnose diagnosis,
5 Cardiovascul doctor, small
ar
lesions that are not
auscultation easily
identified,ambient
noise, status of the
physician(tired,
stress), top down
processes
A2 Conduct
Pulmonar
Ausculation
A2 Conduct
Pulmonar
Ausculation
A3 Conduct
skin, hair
and nails
exam
A3 Conduct
skin, hair
and nails
exam
4
3 2
24 Activities The
to
corrobor
ate
diagnosis
wrong
treatment,
patient
condition could
aggravate
Rapid pace of the
encounter might
lead to incorrect
site selection
Incorrect
association of
an acquired
datum with a
site setting; for
example,right
lung sounds
captured as left
lung.
Missing or
incorrect data
acquired on the
instrument and
transferred to
other systems;
potential for
misdiagnosis or
inappropriate
treatment
7
5 6 210
No instrument
preveniative
maintenance
program
Instrument is
not correctly
calibrated
Instrument
acquire and
record wrong
data
4
2 4
Fail to detect
an important
lesion
4
6 6 144 To get
Top down process, Not inspecting
forgetting due to
all the areas
distractions
Not paying
attention,
experience of the
doctor,
Not identifying a Fail to detect
suspicious
an important
lesion
lesion such as
cancer, it
spreads fast,
fatal
consequences
32
proper
and
complete
feedback
from
patient
regarding
symptom
s
4
2 6
48 Repeatin
g the
task
again
(or)
maintain
surroundi
ngs quite
and calm
system
should
provide
means to
corrobora
te the
correct
caracteriz
ation of
heart
sounds
A3 Conduct
skin, hair
and nails
exam
Knowledge, Lack
of previous
experience, not
paying special
attention
Describe
Wrong
lesions wrongly diagnosis, fatal
consequences
5
3 6
90 To check
with
experts
or check
for
similar
instances
in prior
reports
online
A1
4A2
5A3
3
Record
findings to
patient's
medical
record
Relevant
Enter the wrong Wrong data
information missing data
gets updated to
and data is
EMR
inconsistent,clinicia
n stressed and
distracted, failed to
detect mistake
6
5 5 150
A1
4A2
5A3
3
Record
findings to
patient's
medical
record
Data entry
problems, Data
management
Provider
receives false
patient record
Wrong data
updated to the
patient form.
Future
consequences
when treating
the patient
4
1 2
A1
4A2
5A3
3
Record
findings to
patient's
medical
record
Each datum
acquired during the
encounter must be
correctly identified
with appropriate
metadata
Incomplete
identification or
documentation
of a specific
datum
Missing or
incorrect data
acquired on the
device and
transferred to
other systems;
potential for
misdiagnosis or
inappropriate
treatment
5
4 5 100
8
Appendix 4 - Requirements
REQUIREMENTS
SOURCE
FUNCTIONALITY
1
The system shall provide means to
communicate with the Electronic medical
records
A0
Conduct Physical examination
2
The system may provide means to allow the
patients to access to their medical records
A0
Conduct Physical examination
3
The system shall update patient electronic
medical records with exam data and findings.
A0
Conduct physical examination
4
The system shall record data in the absence of
an internet connection.
A0
Conduct physical examination
5
The system should provide means to record and
recognize user's voice sounds
A0
Conduct physical examination
6
The system shall provide means to guarantee
the safety of the users (physician, patient,
maintenance staff) when it is in use.
A0
Conduct physical examination
7
The system shall provide means to listen to and
record heart sounds.
A13
Conduct Cardiovascular
Auscultation
8
The system shall provide means to correctly
record sounds from the physical examination in
presence of noisy environments
A13/A24 Conduct cardiovascular
Auscultation/Conduct
Pulmonary Auscultation
9
The system should provide means to capture
blood pressure and heart rate.
A0
Conduct Physical examination
10 The system shall provide means to calculate and A13
record the heart rate.
Conduct cardiac Auscultation
11 The system shall provide means to listen to and
record lung sounds.
A24
Conduct Pulmonary
Auscultation
12 The system should provide means to capture
dermatologic image.
A3
Conduct skin,nails and hair
examination
13 The system shall provide means to view and
capture images and videos of the eyes.
A4
Conduct eye exam
14 19. The system shall provide means to capture
pictures with a resolution at 1900*1200.
A4/A5
Conduct eye exam/Conduct
ear exam
15 20. The system shall provide means to view and
capture images and videos of the ears.
A5
Conduct ear exam
16 21. The system should provide means to record
handwritten notes.
A6
update EMR/encounter form
17 Corners and edges of fixed and handheld
equipment to which the bare skin of the crew
could be exposed shall be rounded as specified
NASA-STD-3001 9.3.1.5
18 Any surface to which the bare skin of the crew
is exposed shall not cause epidermis/dermis
interface temperature to exceed the pain
threshold limit of 44 °C (111.2 °F).
NASA-STD-3001 9.3.1.10
19 Any surface to which the bare skin of the crew
is exposed shall not cause skin temperature to
drop below the pain threshold limit of 10 ºC
(50 °F).
NASA-STD 9.3.1.11
USABILITY
20 The system shall be portable.
A0
Conduct physical examination
21
A0
Conduct physical examination
22 The system shall have a means for grasping,
handling, and carrying
A0
Conduct physical examination
23 The system shall weigh less than or equal to 1
lbs.
A0
Conduct physical examination
24 System shall be capable of continuous and
autonomous operation for no less than 2 hours.
A0
Conduct physical examination
25 The system shall be resistant to impact from
dropping or bumping.
A0
Conduct physical examination
26 The system shall adapt to a physician’s *mental
model* of exam flow.
A0
Conduct physical examination
27 The system shall operate in an *intuitive*
manner requiring no written instructions.
A0
Conduct physical examination
The system shall be hand held.
28 The system shall be easy to clean.
A0
Conduct physical examination
29
The system shall have a germ-resistant surface.
A0
Conduct physical examination
30
The system elements shall be smaller than 14”x A0
9”x 3”.
Conduct physical examination
31 The system shall provide mechanisms to
prevent mistakes that may occur when using the
system
A0
Conduct physical examination
32 The system should provide assistance to the
physician to make an appropriate diagnosis.
A0
Conduct physical examination
33
System interfaces shall be easy to navigate
A0
Conduct physical examination
34 The system shall provide feedback to the users
with regards their actions and the consequences
of them
A0
Conduct physical examination
35 The system shall provide a means to inform the
users when it is not working properly or needs
calibration.
A0
Conduct physical examination
36 The system should use graphics and icons to
make operations understandable
A0
Conduct physical examination
37 The system interface should avoid absolute
judgment limits
Principles of display design
38 The system interface should exploit top-down
processing
Principles of display design
39 The system interface should exploit redundancy
Principles of display design
40 The system interface should use discriminable
elements.
Principles of display design
41 The system interface should exploit the
principle of pictorial realism
Principles of display design
42 The system should provide a recovery solution
to user when an error or misuse occur.
User centered principle
(Norman, 2002)
PLEASURE
43 The system shall promote an *engaging*
interaction with the user.
44 The system should provide a *pleasurable
experience* to the user while interacting with
the product.
45 The system should provide an emotion
detection software
46 The system shall provide means to *promote*
communication between physicians and patients
47 The system should not interrupt physicians
when they are interacting with the patient or
analyzing the patient information
48 The system should provide means to prevent the
physician from feeling incompetent or insecure
(because not knowing how to use it)
Appendix 5 DESIGN PRODUCTS | MULTIFUNCTIONAL SENSOR
FRONT
PART 1
BACK
}
Viewfinder and camera
Otoscope | Ophtalmoscope |
Camera zone
Record button
}
Stop button
Mode buttons
and
Power switch
USB port
Headset out
Stethoscope membrane
Stethoscope area
Appendix 6 Explanation of Graphical User interface in iPad
This design is the software part of the healthcare tool kit, used to to navigate the
physician to finish information collection in patient’s encounter. The cardiological
information collection is used as an example to explain the operations of the software
interface.
1.
FIGURE 1. Main interface for data entry
This screen(figure 1) is the main page of this interface and navigate the physician to
finish the whole encounter information collection.
The patient’s personal information is always displayed on the top colon of all pages so
that physician can easily check the patient’s information. All items that may need to
exam in an encounter are listed on left of the screen. From this list, physician can start
one examination and information collection by selecting one item.
2.
FIGURE 2 Heart sound recording entry interface
If one item from the left list is selected(figure 2) , the item will expand and display
related control icons while the other items remain unchanged(the expanded item will
return normal when re-clicked). And here the Cardiovascular is selected and more
control menus are provided to conduct information collection. And these four icons in the
expanded item from left to right respectively are ‘WNL’, used to indicate the patient’s
health condition of this item, text inputting icon, voice inputting icon and recording icon.
3.
FIGURE 3 Welcome screen for recording heart sounds(if the stethoscope is off)
If the sound record button in last page is pressed, a new screen(figure 3) will pop up to
show the user to turn on electronic stethoscope and place it on the right place. And in the
bottom of the page, user can get access to sound database by selecting the ‘sound
database’ icon on the left and the patient’s previous encounter information.
4.
FIGURE 4 Heart sound recording
Once the iPad set up the communication channel with the instrument and begins to
receive sound data from the instrument, the screen interface(figure 4) will automatically
appear with phonocardiogram image. The user can listen to the sound through the iPad or
mute the sound and just see the phonocardiogram real time image. The user can pause the
real-time display and then continue when needed or begin to record by select the record
button. And the search bar on the upper left directs the user to get necessary information
in the system.
5.
FIGURE 5 Interface showing recorded phonocardiogram image and heart sound
FIGURE 6 Interface showing warning message before deleting a file
1) When the record button is selected(this operation can be done by pressing the record
button on the instrument), it will change into a red stop icon notifying the user that the
device is recording.
2). When the recording is stopped a display icon will replace the former sound wave
image, indicating that the record is finished and the user can redisplay it. And two icons
in bottom left provide user choices to email, delete or save the sound data(figure 6). Also
the related information about this record is automatically appear on the upper left of the
image.
6. email
FIGURE 7 Interface showing mailing icon to start a communication with others
FIGURE 8 Emailing interface
To e-mail a recording, click on the envelope icon (the first icon in the bottom left of the
image) . Once it is opted, an e-mail interface opens and the new email contains the sound
file from the patient and any notes the user may want to include(figure 8). Once the mail
is dispatched to recipient, a message “Message was sent” with audible tone appears on
the interface to provide a confirmation to the user.
7. compare
FIGURE 9 Interface showing starting an comparison
FIGURE 10 Interface showing comparing the patient’s sounds with the reference
database
If a user wanted to research pathologic heart sounds for comparison, they could access
the multimedia library by clicking on the Library icon(figure 9). Since the library is
accessed from the heart sound screen, only heart sound data will be visible as shown in
figure XX, If the user finds anything of specific interest to the ailment, he can choose a
specific type of pathological sound to compare the current recording with. Once chosen, a
comparison interface will appear (as given in XX). It includes a recording as well as a
visual profile for comparison(figure 10).
Also, other comparisons are available with those record data of the patient’s previous
examination just by selecting the icons in the bottom left of the screen.
8. return to main page.
FIGURE 11 Main screen with updated cardiovascular information
Once a heart sound recording is complete and the user has navigated back to the main
screen the corresponding icon will change from blue to gray and embody a ‘image’ icon
which indicates that the record is available. Also the physician can move the button in the
WNL icon to left to indicate the patient’s heart is health. The character of this item
‘Cardiovascular’ will turn gray and be followed by main results of this item, indicating
this is a finished item(figure 11).
Then with the similar operations, user can conduct another information collection in the
same way.
Appendix 7 - Test Plan
Participants
The participants will be senior physicians and students from medical college,
considered as different clinical experience. Furthermore, they will be separated into two
groups considered have tablet using experience or not. We will need 5 to 10 participants
for our evaluation in total.
Apparatus, Instruments
The main parts of the system are an iPad with HT user interface and a
multifunctional medical device (mockup). Rulers and stopwatches will be the
measurement equipments to test and evaluate the system. Questionnaires are made of
open-end, dichotomous, multiple-choice, Likert scale, and subjective questions. We also
use human factors checklist in heuristic evaluation to see if general HF consideration are
addressed in the design.
Testing and Evaluation Methods
REQUIREMENTS
SOURCE
METHOD FOR VERIFYING
1
The system shall provide means to
communicate with the Electronic medical
records
A0
Conduct Physical
examination
By demonstration whether the system
provide the function to save and receive
patient's information to and from EMR.
2
The system shall update patient electronic
medical records with exam data and findings.
A0
Conduct physical
examination
By demonstration whether the system can
save patient's encounter data to EMR.
3
The system shall record data in the absence of
an internet connection.
A0
Conduct physical
examination
By demonstration whether the system can
save patient's encounter data in local area
4
The system shall provide means to listen to and
record heart sounds.
A13
Conduct
Cardiovascular
Auscultation
By demonstration whether the system
provide the stethoscope function.
6
The system shall provide means to calculate
and record the heart rate.
A13
Conduct cardiac
Auscultation
By demonstration whether the user can get
the patient's heart rate from the system
5
The system shall provide means to listen to and
record lung sounds.
A24
Conduct
Pulmonary
Auscultation
By demonstration whether the system
provides stethoscope function.
6
The system should provide means to capture
dermatologic image.
A3
Conduct skin,nails
and hair
examination
By inspection whether the system provides
a camera that can take dermatologic
pictures.
7
The system shall provide means to view and
capture images and videos of the eyes.
A4
Conduct eye exam
By inspection or demonstration whether
the system provides a camera that can take
pictures and videos of the eyes.
8
The system shall provide means to view and
capture images and videos of the ears
A5
Conduct ear exam
By inspection or demonstration whether
the system provides a camera that can take
pictures and videos of the ears.
9
The system should provide means to record
handwritten notes
By inspection whether the system can save
user's handwriting.
10
Corners and edges of fixed and handheld
equipment to which the bare skin of the crew
could be exposed shall be rounded as specified
NASA-STD-3001
9.3.1.5
By Inspection whether the multifunctional
instrument has round edges and corners
instead of sharp edges that would hurt
users.
11
Any surface to which the bare skin of the crew
is exposed shall not cause epidermis/dermis
interface temperature to exceed the pain
threshold limit of 44 °C (111.2 °F).
NASA-STD-3001
9.3.1.10
By testing whether the interface
temperature of the handheld part of the
instrument would exceed 44 °C when it's
in work.
12
The system shall be portable.
A0
Conduct physical
examination
By testing whether the dimension of the
system is small than 14”x 9”x 3”.
13
The system shall be hand held.
A0
Conduct physical
examination
By testing whether the dimension of the
system is small than 14”x 9”x 3” and
weight less than 1lb for hand held.
14
The system shall have a means for grasping,
handling, and carrying
NASA-STD
9.3.1.12
By inspection whether the system can be
held by hand firmly.
15
The system shall weigh less than or equal to 1
lbs.
A0
Conduct physical
examination
By testing whether the system weight less
than 1 lbs.
16
System shall be capable of continuous and
autonomous operation for no less than 2 hours.
A0
Conduct physical
examination
By demonstration whether it can run
continuously at least 2 hours.
17
The system shall be resistant to impact from
dropping or bumping.
A0
Conduct physical
examination
By drop test to verify whether the system
provides necessary ways to protect the
system physical feature and function
18
The system should provide assistance to the
physician to make an appropriate diagnosis.
A0
Conduct physical
examination
By demonstration whether the use can
finish the process of an encounter
information collection just through the
navigation of the interface.
19
System interfaces shall be easy to navigate
A0
Conduct physical
examination
By demonstration whether the use can
finish the process of an encounter
information collection just through the
navigation of the interface.
20
The system shall provide feedback to the users
with regards their actions and the
consequences of them
A0
Conduct physical
examination
By demonstration whether the system
provide necessary feedback when a button
or an icon is pressed.
21
The system shall provide a means to inform the
users when it is not working properly or needs
calibration.
A0
Conduct physical
examination
By demonstration whether the system will
alert the user when the power is low or
some other problems like that camera can
not work properly.
22
The system should simplify the tasks; do not
overload memory, short term or long term,
provide memory aids for easy retrieval of
information and be sure the user has control
over the task.
User centered
principle (Norman,
2002)
By demonstration and testing whether the
system provides means to reduce or aid
memory. Whether the user should
remember a lot of things to finish a
process of patient encounter.
23
The system should use graphics to make things
understandable
User centered
principle (Norman,
2002)
By inspection whether the buttons or icons
are presented with special marks or
recognizable graphics
24
The system should provide legible or audible
displays
Principles of
display design
By demonstration the display and find out
whether the user can see and hear clearly
when something is displayed.
Scenarios
We conduct role-playing simulation trials for testing and evaluating the system as
scenarios as below.
“You are examining a young patient who complaining of chest pain, fainting with
exertion, shortness of breath, fatigue, especially during times of increased activity and
heart palpitations. After completing anamnesis you decide to conduct a cardiological
exam.
Physician: Conduct cardiological auscultation in one area
1. Check on the iPad application, select the physical examination section
2. Place the patient on the bed
3. Plug headsets to the device
4. Place the device at area of interest
5. Record heart sound
6. Stop recording
7. Review the sound at the iPad screen
8. Compare it with the sound database
9. Send the file to an specialist and request advice
Human Performance Measures
The dependent variables in the test will be four aspects which are recorded by the
observers during the process as following:
Speed-Time to complete an assigned task or to find the information needed
Accuracy-Number of mistakes
Training Time-Whether remember how to fulfill some functions after a fixed time of
training or practicing
Satisfaction-Participants attitudes, body language, or subjective answer on the
questionnaire
Testing Procedure
The test include three stages: the first one will be introduction, training, and practice,
second one is the scenario we defined earlier, last one is to complete the questionnaires
1. Basic function overview of the system
2. Applicable objects introduction
3. Explain the functions of buttons on the device to the testers
4. Connect the system and initiate or resume a cardiac inspection on a new or an
existing EMR
5. Record a piece of heart sound and save it
6. Replay the sound file and compare it to the sample file in the database
7. Make a diagnosis decision according to the sound file and write it to EMR
8. Answer the questions on the questionnaire
Analysis
We will do a two-way ANOVA for the data collected from the participants to check if
any factor is significant to this medical test. What do people think with different medical
experiences? Is there any difference between tablet usage background? What are their
comments? Eventually, we want feedbacks to get improvement to our design. The
performance of the participants will be evaluated by the following factors
Time to complete a task
Number of mistakes
How easy they find the information needed
If they remember how to use the device after a short-time training and practicing
Schedule
Ramp up / System familiarization
6/01/2012 - 6/15/2012
System Test
6/16/2012 - 8/26/2012
Beta Test
7/28/2012 - 8/18/2012
User Acceptance Test
8/29/2012 - 9/03/2012
Questionnaire sample
1. Do you think the device is easy to carry around? (Y/N)
How important is this to you (0 = strongly not important; 10 = very important)
2. Do you think the device is easy to clean? (Y/N)
3. Do you agree that the system is easy to learn how to use? (0 = strongly disagree; 10 =
strongly agree)
4. Do you agree that the test procedure provided by the system is easy to remember? (0 =
strongly disagree; 10 = strongly agree)
5. What do you think of the font size of this UI?
A. too big B. a little big C. appropriate D. a little small E. too small
6. What do you think of the icon size of the UI?
A. too big B. a little big C. appropriate D. a little small E. too small
7. Which of the following aspects satisfied you most?
A. font B. icon C. layout D. color E. response time
8. Which of the following aspects dissatisfied you most?
A. font B. icon C. layout D. color E. response time
9. Your working experience ___year(s)
10. Other comments
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