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2009 International Symposium on Wearable Computers
Clinical Implementation of a Head-Mounted Display of Patient Vital Signs
David Liu
The University of Queensland
[email protected]
Simon A Jenkins
Royal Adelaide Hospital
[email protected]
Penelope M Sanderson
The University of Queensland
[email protected]
Abstract
Head-mounted displays (HMDs) can superimpose a
patient’s vital signs over the anesthesiologist’s field of
view in the operating room. Prior simulator-based
studies have found that anesthesiologists wearing an
HMD spend more time looking towards the patient and
less time looking towards the monitors compared to
standard monitoring. We review potential approaches
for interfacing an HMD with clinical monitoring
equipment at the Royal Adelaide Hospital, and
describe the technical solution we implemented.
Furthermore, we implemented a method of recording
video data in the operating room without interfering
with normal clinical practice. Finally, we present
analyses of two clinical scenarios where HMDs might
be particularly useful.
Figure 1 An anesthesiologist monitors the patient and
surgical area while also monitoring vital signs presented on
the HMD (monocle over the right eye). A head-mounted
video camera (above HMD) and wireless lapel microphone
(clipped onto the backpack strap) were used to record video
data.
1. Introduction
In the operating room, the anesthesiologist manages
the major side effects of surgery and any co-existing
diseases, and supports the homeostatic control of
oxygenation, ventilation, and perfusion to core organ
systems [1]. Anesthesiologists use many electronic
sensors to monitor the patient’s vital signs, which are
presented as numbers and waveforms on an electronic
display. The electrocardiogram (ECG) waveform and
the pulse oximeter (and its associated tones) are two
examples of vital signs displayed on the patient
monitor.
However, when the anesthesiologist is busy with
other tasks, they may not notice changes on the
monitor. Auditory alarms are designed to alert the
anesthesiologist to important changes in the patient’s
physiological status, but are often false, noisy,
uninformative and frequently turned off [2,3].
Wearable computers have been proposed as a
potential solution to the problems with alarms [1,4,5,6].
Monitoring displays using various sensory modalities
have been described in the literature including
978-0-7695-3779-5/09
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2009 IEEE
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DOI 10.1109/ISWC.2009.36
auditory, vibro-tactile, electro-tactile, and headmounted displays (HMDs). In this paper, we focus on
the role of HMDs in patient monitoring.
Head-mounted displays (Figure 1) can superimpose
the patient’s vital signs over the anesthesiologist’s field
of view no matter where they are in the operating room
or where they are looking (Figure 2). Evaluations in
clinical and simulated operating room environments
have reported that HMDs can help anesthesiologists
and surgeons spend more time focusing on the patient
and surgical area instead of the monitors [7,8,9,10], help
anesthesiologists and surgeons detect changes in the
patient’s vital signs faster when they are busy or
physically constrained [8,11], and are generally wellreceived by anesthesiologists [12,13,14,15].
However, the reported evaluations had numerous
technology limitations that restricted the utility of the
HMD. The limitations include incomplete displays of
vital signs from the patient monitors [8,12,13],
equipment bulk restricting the mobility of the
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2. Clinical implementation of an HMD
The primary aim of this study was to determine
whether introduction of the HMD would be (a)
acceptable and (b) useful to anesthesiologists.
Furthermore, trials of the HMD would be recorded on
video for behavioral analysis. The goals of the clinical
implementation required interfacing an HMD with the
clinical monitoring equipment in use at the Royal
Adelaide Hospital (see Figure 4) to display patient vital
signs on the HMD in real time.
2.1. Vital signs display
Figure 2 Simulated image of the anesthesiologist’s apparent
view while wearing an HMD.
There are no commercially available solutions for
interfacing an HMD with either a patient monitor or a
ventilator (to the authors’ knowledge) therefore we
needed to develop a custom solution. The
anesthesiologists’ work environment imposed three
design constraints. First, the HMD needs to be
untethered so that the anesthesiologist can move freely
around the operating room. Second, since
anesthesiologists have direct contact with patients, the
HMD must be electrically isolated to prevent the risk
of micro-shocks. Third, the delay between the vital
signs being presented on the standard monitors versus
the HMD should be minimal.
We surveyed the range of input/output interfaces
supported by the Microvision Nomad family of HMDs,
the IntelliVue MP70 patient monitor, and the Aestiva
AS/5 ventilator. The Nomad HMDs could either
display an external VGA signal, or could be driven by
an embedded computer running Windows CE. The
Philips IntelliVue MP70 monitor exported its vital
signs data in three ways: a VGA output mirroring the
patient monitor’s own display, or via digital data
streams using either an RS232 or an Ethernet port. The
digital data was exported in the Philips Data Export
Protocol format [16], based on the ISO 11073 family of
standards. Data from the Datex-Ohmeda ventilator was
only exported via a proprietary protocol through an
RS232 port [17].
Three potential solutions were identified from the
combinations of supported interfaces (see Table 1).
Each solution is described in turn, below, along with
their advantages and disadvantages.
The first and simplest solution is to pass-through a
video feed from the patient monitor to the HMD (as
used by [9,13]). With this approach, there would be no
delay or difference between the image presented on the
monitor or the HMD. The disadvantages however, are
that the layout of the vital signs display cannot be
rearranged, digital log files cannot not be recorded,
video can be sourced from only one device, and may
anesthesiologist [8,12,13,15], and tethering of the HMD
to the anesthesia machine [12,13].
None of the reported studies have investigated how
HMDs affect anesthetic practice. Although several
studies have found that HMDs help redirect the
anesthesiologist’s attention towards the patient, there
has been no analysis of the types of situations where
the redirected attention may be useful. Furthermore,
HMDs have been hypothesized as being particularly
useful during crisis management [8,13], but there has
been no research on HMD use during crises.
In this paper, we present a clinical implementation
of a head-mounted display of patient vital signs in the
operating room for a controlled trial (reported in [10]).
First, we describe the technical pathways for
interfacing an HMD with patient monitoring
equipment. We then present two clinical scenarios that
demonstrate how HMDs might affect the
anesthesiologist’s monitoring behavior when they are
busy or during a crisis. Finally, we draw conclusions
on the clinical potential of patient monitoring with
HMDs.
Figure 3 The anesthesiologist adjusts the operating table while
monitoring the patient’s vital signs on the HMD. Without the
HMD, the anesthesiologist would not be able to easily see the
patient monitor (top-left foreground).
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have reduced image quality due to the video
conversions and wireless transmission.
The other two solutions are different in that they
retrieve the patient’s vital signs as a digital data stream
from the patient monitor via network protocols (in
contrast to streaming video). The primary advantage of
data streaming is that the vital signs display can be
customized, reorganized and designed specifically for
the HMD. Vital signs data can also be sourced and
integrated from multiple monitoring devices (e.g. the
patient monitor and ventilator), or recorded in digital
log files. The disadvantage with data streaming is that
a significant amount of programming is required
because the protocols can be complex and software
drivers are not always available. Furthermore, the
monitoring devices may not export all available data
(e.g. the CO2 waveform is unavailable when the MP70
monitor is used with the Anesthetic Gases Module) and
the data stream may also be delayed.
The first data streaming approach is to develop an
embedded Windows CE application for the Nomad
HMD that communicates directly with the MP70
monitor over an 802.11b wireless network (as used by
[7]). While this approach requires the least amount of
equipment of the three solutions, developing for an
embedded platform is time consuming and may
produce software that is not directly portable to other
applications. Further, the signal strength of the wireless
adapter was weak and the 2.4 GHz radio had
interference with other devices in use (wireless video
camera, laptops, and cordless phones).
The alternative data streaming approach is to have
the anesthesiologist wear a handheld PC computer in
addition to the HMD (similar to [12]). For example, the
Sony Vaio U50 handheld computer runs a standard
version of Windows XP therefore developing software
for this device is identical to developing desktop
a
b
c
e
d
Figure 4 One of the anesthesia machines in use at the Royal
Adelaide Hospital. The machine includes (a) the patient
monitoring display, (b) the ventilator control and monitoring
display, and (c) an electronic anesthesia record keeper. The
(d) portable audiovisual equipment trolley (see Figure 5) and
(e) secondary patient monitor (both used only during the
study) can be seen in the background.
software. The other advantage is that a 5 GHz 802.11a
adapter can be used to avoid wireless interference.
However, the main disadvantage was requiring the
anesthesiologist to wear the additional weight and bulk
of the computer.
We chose to implement the data streaming approach
using a handheld PC [10]. The anesthesiologist wore a
Microvision Nomad ND2000 HMD with a single
monocle over the right eye. The Nomad’s control and
battery unit was connected to a Sony Vaio U50
handheld PC using a VGA adapter; both stowed in a
backpack worn by the anesthesiologist. The U50
communicated with a data interfacing laptop (see
Table 1 The advantages (highlighted by +) and disadvantages (highlighted by -) of the three approaches to interfacing a
patient monitor with an HMD. Some of the advantages and disadvantages are common to any “data interfacing” approach,
and are shown accordingly.
Video pass-through
+ No programming required
+ HMD image identical to patient
monitor display
+ No delay between patient monitor
and HMD
- Display elements cannot be
customized
- Video from one device only
- Video scaler required to adjust
resolution/refresh rate
- Wireless VGA transmitter and
receiver required
- No digital data logging
Embedded computer
Handheld PC
+ Patient monitor display can be customized
+ Vital signs data can be integrated from multiple devices
+ Digital records of vital signs data can be easily recorded
+ No extra equipment needed
+ Internal 802.11b wireless adapter
+ Ease of development (standard
PC software)
+ Able to use 802.11a wireless to
reduce interference
- Significant programming effort to interface with monitors
- CO2 waveform not exported via data interface
- Minor delay between when vital signs are displayed on monitor
and exported via data interface (1 – 2 seconds)
- Time consuming developing for
embedded platform
- Software not portable
- Weak wireless signal
- Significant 2.4 GHz interference
- Extra weight and bulk of the
computer unit
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Figure 5) over an 802.11a wireless network and ran
custom Java software to render vital signs on the HMD
with a similar layout to the standard patient monitor.
The laptop interfaced with a Philips IntelliVue
MP70 patient monitor and a secondary MP30 monitor
to retrieve real-time vital signs information over
Ethernet. The laptop ran Java software that we
developed to communicate with the patient monitors,
integrate the data from both monitors, record digital
log files of the patient’s vital signs, and to broadcast
the vital signs over the wireless network.
The vital signs on the HMD (Figure 2) were
arranged in a similar layout as the MP70 patient
monitor (Figure 6d) and were streamed with a
clinically insignificant delay [18] of 1 - 2 seconds. As
the HMD communicated wirelessly with the patient
monitors, the anesthesiologist was free to move around
the operating room unencumbered.
operating room. There were several design
considerations aimed to prevent the data capture
equipment
from
interfering
with
workplace
productivity or compromising patient safety. First,
delays to surgical lists due to setting up, removing, or
operating the data capture equipment were not
acceptable. Second, malfunctioning data capture
equipment should not cause electrical interference or
disruptions to life support equipment or surgical tools.
Finally, as the process of data collection was extremely
labor intensive and therefore limited to a small cohort
of cases, the risk of data loss should be minimized.
We developed a portable solution that captured
video and audio from multiple locations. Two
handheld video cameras were mounted on IV drip
stands and placed on opposite sides of the anesthesia
work area. A scan capture box converted the VGA
output of the MP70 patient monitor into composite
video. A wireless video camera was attached to the
head-mount of the Nomad HMD. Audio was captured
by a microphone attached to a video camera and by a
wireless
lapel
microphone
worn
by
the
anesthesiologist. A quad video processor combined the
four independent video feeds into one signal. The
combined video signal was split to two, redundant
hardware MPEG-2 video encoders. Two laptops were
connected to the video encoders (one laptop for each
encoder) and the recorded videos were saved directly
in digital format.
The audiovisual equipment was mounted on a
trolley and connected to an isolated electrical circuit in
the operating room via an uninterruptible power supply
(UPS) or an isolation transformer. With the UPS, all of
the equipment could be turned on and in recording
mode outside the operating room. At the start of a case,
all of the equipment could be moved inside the
operating room and cables attached in five minutes.
Similarly, the equipment could be packed up and
removed rapidly at the end of each case.
2.2. Video data capture
In addition to presenting vital signs on the HMD,
we also developed a system to record video data in the
a
b
a
c
e
c
d
2.3. Experimental design
The video data was captured for a study that
investigated the effects of an HMD on the monitoring
patterns of anesthesiologists in the operating room [10].
Six anesthesiologists each provided anesthesia to three
patients with an HMD and three patients without the
HMD, for a total of 36 surgical cases in the
experiment. Analysis of the video data showed that
when the anesthesiologists used the HMD, they spent
significantly less time looking towards the anesthesia
machine (21.0% vs 25.3%) and significantly more time
looking towards the patient (55.9% vs 51.5%)
compared to standard monitoring. Full details of the
head turning analyses are described in [10].
Figure 5 The experimenter configures the audiovisual
equipment trolley for the study. The trolley contains (a) a
laptop for interfacing with the patient monitors, (b) two laptops
for redundant video recording, (c) quad video processor and
hardware MPEG-2 encoders, (d) an audio mixer, isolation
transformer, and uninterruptible power supply, and (e) the
HMD and backpack when it is not being worn by the
anesthesiologist.
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While analyzing the video, we also observed two
clinical scenarios where the HMD may be particularly
beneficial.
Table 2 Contingency table showing whether the
anesthesiologist looked at the patient monitor to confirm LMA
placement, with and without the HMD.
Looked
3. Scenario 1: Confirmation of airway
Several simulator-based studies have found that
HMDs allow anesthesiologists to redirect their visual
attention away from the anesthesia machine and
towards the patient. However, the studies only reported
summary statistics of where the anesthesiologist
looked, but did not indicate the types of situations or
activities that would most benefit from the HMD.
Whilst analyzing the video data from the present
study, we observed one task where the HMD could be
beneficial: confirming the correct placement of the
laryngeal mask airway (LMA). The LMA is an airway
device that helps anesthetized patients breathe through
the ventilator during surgery. After the device is
inserted into the patient’s airway, it is important for the
anesthesiologist to confirm its correct placement by
listening to the patient’s breath sounds, watching the
chest rise and fall, and checking that CO2 gas is
exhaled [19].
The anesthesiologist listens to the patient’s breath
sounds and watches their chest rise and fall by facing
the patient. However, CO2 exhalation is confirmed
using capnography, presented on the patient monitor
located directly behind the anesthesiologist (see Figure
7). Normally, the anesthesiologist would need to turn
around to see the patient monitor. We hypothesized
that anesthesiologists will turn to look at the patient
monitor less frequently when they use the HMD than
with normal monitoring alone.
Did not look
Control
11
7
HMD
8
10
3.1. Methods
We reviewed the 36 case videos to determine
whether the anesthesiologist looked at the patient
monitor to confirm the correct placement of the LMA.
The portion of video analyzed began with the
anesthesiologist picking up the bag from the ventilator
(see Figure 7) and concluded when the bag was
replaced. A 2x2 contingency table was created based
on whether the HMD was available (Control vs HMD)
and whether the anesthesiologist looked at the patient
monitor (Looked vs Did not look). Differences in the
number of cases where between the cells were tested
for significance with a one-tailed Fisher’s Exact Test
and α=0.05 using the R statistical package (R
Foundation for Statistical Computing).
3.2. Results
Table 2 shows the number of surgical cases in
which the anesthesiologist looked at the patient
monitor to confirm LMA placement. The differences
were not statistically significant (p=0.25).
3.3. Discussion
Although the differences were not significant, the
ratios are in the hypothesized direction. For the same
ratios to be statistically significant, a much larger
sample would be required (150 cases).
If HMDs are in fact useful in this situation, there are
several explanations for why it was not demonstrated
in the results. First, participants experienced the HMD
for a relatively small amount of time (three cases of an
average duration of 31 minutes) and it may not have
been sufficient for them to change their normal
monitoring patterns. Second, the HMD did not display
variables from the ventilator (such as tidal volume)
therefore participants may have had to turn to look at
the ventilator anyway. Third, participants normally
replaced the reservoir bag back on the ventilator after
confirming the LMA placement and it may have been
easy for them to look at the patient monitor at that
time.
HMDs may be useful in situations where there is a
need for the anesthesiologist to frequently redirect their
Figure 6 Screen capture from the recorded video data in the
operating room. Clockwise from top-left: (a) head-mounted camera
view of the anesthesiologist inserting the laryngeal mask airway,
(b) field camera view of the operating room, (c) the patient
monitoring display (see Figure 4a), and (d) reverse angle field
camera view.
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episode occurred when the anesthesiologist was using
the HMD (referred herein as Episode H) and the other
episode occurred without the HMD (Episode C).
However, there is insufficient data with only two
episodes to perform a direct comparison of crisis
management using standard monitoring versus
standard monitoring with an HMD.
Instead, the anesthesiologists’ monitoring behavior
during the two episodes was compared against the
same anesthesiologists’ monitoring behavior during
normal monitoring without the HMD. Therefore the
two episodes are examples of how monitoring patterns
during a crisis differs from normal monitoring.
4.1. Methods
Figure 7 The anesthesiologist squeezes the reservoir bag to
confirm the correct placement of the laryngeal mask airway.
The HMD displays a CO2 waveform so that the anesthesiologist
does not need to turn around to look at the patient monitor (topleft foreground).
We coded changes in the anesthesiologists’
direction of gaze throughout each case from the video
data. Their monitoring behavior was measured by three
variables for two locations in the operating room: the
Proportion of time spent looking (percentage), the
Frequency of looks (per minute), and the median
Duration of looks (seconds), towards the Anesthesia
Machine or towards the Patient – a total of six
variables. The six variables were calculated from the
coded video data for the regurgitation episodes and the
anesthesiologists’ three cases without the HMD as a
baseline.
The differences between the episode and baseline
values for the Proportion and Frequency variables were
tested for significance (separately for each episode)
with two-tailed t-tests against an independent sample
using StatisticaTM and α=0.05. Differences in the
Duration variables were tested using a two-tailed
Mann-Whitney U test with StatisticaTM and α=0.05.
visual attention to the patient monitor, even though
there is a low likelihood of a problem. For example,
auditory alarms from the monitor are frequently
sounded despite them often being false, but using an
HMD the anesthesiologist would not have to direct
their attention away from the current task. Similarly,
after they perform an intervention (such as
administering a drug) they can monitor the patient for
adverse reactions without having to turn around.
4. Scenario 2: Crisis management
Prior studies suggest that crisis management would
be a useful application of HMDs in anesthesia [8,13],
but no study to date has evaluated HMD use during
crises. For the second clinical scenario, we examine
two episodes of an anesthesia crisis (regurgitation of
gastric contents) observed in the operating room.
Patients undergoing general anesthesia are fasted to
reduce the risk of regurgitation and aspiration of
gastric contents [20] and therefore minimize the risk of
subsequent pneumonia.
The episodes were managed in the same way by the
anesthesiologist: 100% oxygen was applied, the
regurgitated material suctioned, the LMA removed,
and the patient was woken up. Coincidentally, one
4.2. Results
Table 3 shows the calculated monitoring pattern
variables during the two regurgitation episodes and the
corresponding baselines.
The anesthesiologist in Episode H spent
significantly less time looking (9.9% vs 26.1%,
p=0.04), and looked less frequently (1.4 vs 3.6 looks
Table 3 The monitoring behavior of two anesthesiologists during episodes of regurgitation compared to their own baselines. The
baselines are calculated by the mean Proportion, mean Frequency, and median Duration of looks during three surgical cases
without the HMD. Significant differences between the episodes and baselines are marked with }.
Proportion
of time
Baseline C
Episode C (no HMD)
18.4%
9.3%
Baseline H
Episode H (HMD)
26.1%
9.9%
Anesthesia Machine
Frequency
(per minute)
3.47
3.61
}
3.61
1.36
}
Duration
(seconds)
Proportion
of time
Patient
Frequency
(per minute)
Duration
(seconds)
1.817
1.124
55.1%
78.6%
5.04
5.98
2.797
2.980
3.63
2.72
2.773
16.212
2.677
2.211
}
37.8%
85.7%
}
}
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}
crisis management. However, there is not enough data
from these results for general conclusions to be drawn
about how anesthesiologists would use an HMD during
a crisis. Further research is required in either controlled
environments such as a full-scale patient simulator, or
in clinical environments with a large number of cases.
per minute, p<0.01), towards the Anesthesia Machine
during the regurgitation episodes compared to their
baseline. The differences between the same variables
for Episode C were not significant. However, in
Episode C the anesthesiologist looked towards the
Anesthesia Machine for significantly shorter periods of
time (1.1 vs 1.8 seconds, p<0.01) compared to their
baseline.
The anesthesiologists spent a significantly higher
proportion of time looking towards the Patient in both
Episode C (78.6% vs 55.1%, p<0.01) and Episode H
(85.7% vs 37.8%, p=0.02) compared to their baselines.
During Episode H, the anesthesiologist looked towards
the Patient for significantly longer periods of time
(16.2 vs 2.8 seconds, p<0.01) compared to the
baseline. The differences in the Frequency of looks
towards the Patient were not significant.
Immediately after Episode H, the anesthesiologist
commented “I was able to monitor the patient without
having to turn around. That’s quite useful.”
5. Conclusions
The following conclusions of the clinical potential
of HMDs are drawn from the results of the clinical
study described in this paper [10] and an associated
program of research in simulators [8,15]. First and
foremost, the HMD does not function as the equivalent
of simply relocating the standard patient monitoring
display to the anesthesiologist’s field of view.
Although the anesthesiologist’s pattern of visual
attention changes they still need to regularly review the
monitor, they attend to the patient differently in a
crisis, and they may fail to notice changes in
continuously moving display elements (such as
waveforms [8]) as easily as with a standard monitor.
Second, HMDs appear to be most useful in
situations where the anesthesiologist is physically
constrained, where there is a need for continuous vital
signs information, and when the display is being
sampled for specific information. Conversely, HMDs
are less useful when the anesthesiologist can easily
access information from the standard monitor, when
there is no need for continuous information, or when
monitoring waveforms for unexpected changes.
For example, an HMD may be very useful for a
prolonged fiber-optic intubation in an unstable patient,
but less so for a quick intubation or for a stable patient.
Similarly, the HMD may be useful with pre-operative
or post-induction patients who are unstable and are
having relatively long and complex procedures
performed by the anesthesiologist (see Table 4).
Finally, HMDs will only be clinically accepted if
they can meet the demands of the anesthesiologist’s
work environment. HMDs need to be small and
lightweight, easy to clean to avoid spreading infectious
diseases, and most importantly, designed to
accommodate the anesthesiologist’s workflow.
4.3. Discussion
The significantly higher proportion of time that
participants in both regurgitation episodes spent
looking towards the patient indicates that the episodes
were physically constraining and required the
anesthesiologists’ sustained attention to the patient.
The anesthesiologist in Episode C maintained a
similar proportion of time and frequency of looks
towards the anesthesia machine, despite the substantial
increase in the time spent looking towards the patient.
This resulted in the shorter looks towards the
anesthesia machine.
During Episode H however, the participant spent
less time and looked less frequently towards the
anesthesia machine compared to their baseline,
demonstrating that the HMD let the anesthesiologist
become less reliant on the patient monitor. This
resulted in significantly longer looks towards the
patient, letting the anesthesiologist focus their attention
on monitoring the patient and managing the crisis.
The two regurgitation episodes show that there is
potential for HMDs to help anesthesiologists during
Table 4 Examples of when an HMD would be particularly useful for anesthesiologists, depending upon the stage of surgery, the
patient status, clinical situation, and the procedure being performed by the anesthesiologist.
Time
Pre-operative
Patient status
Unstable
Clinical situation
Trauma
Massive bleeding
Cardiac tamponade
Procedure
Fiber-optic intubation (awake)
CVC insertion
Regional blockade
Complicated arterial line access
Post-induction
Relatively unstable
Trauma
Massive bleeding
Severe cardiac disease
Sepsis
Cardiac tamponade
Intercurrent surgical disaster
Fiber-optic intubation
Difficult (protracted) intubation
CVC insertion
Regional blockade
Complicated arterial line access
Monitoring massive transfusion
Communication with other staff
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In future work, further investigations of how HMDs
can help during specific activities (such as the two
clinical scenarios described in this paper) will be best
performed in simulated operating room environments
for a greater level of control, reproducibility, and
statistical power. More research is needed on how to
design an effective layout of vital signs on an HMD
while balancing the trade-off between clutter and
convenience. Finally, the greatest challenge will be
determining whether an HMD is clinically effective.
[9] A. Beuchat, S. Taub, J.D. Saby, V. Dierick, G. Codeluppi,
A.F. Corno, L.K. von Segesser, “Cybertools improve reaction
time in open heart surgery,” European Journal of
Cardiothoracic Surgery, vol. 27, pp. 266-269, 2005.
[10] D. Liu, S. Jenkins, P. Sanderson, P. Fabian, and W.J.
Russell, “Monitoring with head-mounted displays: Clinical
evaluation in anesthesia for rigid cystoscopy,” Anesthesia and
Analgesia, accepted pending minor revisions.
[11] D.K. Via, R.R. Kyle, C.H. Shields, M.J. Dymond, L.A.
Damiano, and P.D. Mongan, “A head mounted display of
anesthesia monitoring data improves time to recognition of crisis
events in simulated crisis scenarios,” presented at the Society for
Technology in Anesthesia Annual Meeting, San Diego, CA,
2003.
6. Acknowledgements
This research is supported by Australian Research
Council Discovery Project grant DP0559504. Liu is
supported by an Australian Postgraduate Award, a
Fulbright Postgraduate Scholarship, and a Churchie
Old Boys Overseas Study Scholarship. We thank
Matthew Thompson, Perry Fabian, John Russell, and
the Royal Adelaide Hospital staff for their assistance.
[12] F.E. Block, D.O. Yablok and J.S. McDonald, “Clinical
evaluation of the ‘head-up’ display of anesthesia data,”
International Journal of Clinical Monitoring and Computing,
vol. 12, pp. 21-24, 1995.
7. References
[13] D.K. Via, R.R. Kyle, P.G. Geiger, P.D. Mongan, “A Head
Mounted Display of Anesthesia Monitoring Data is of Value and
Would be used by a Majority of Anesthesia Providers,”
Anesthesia and Analgesia, vol. 95, pp. S132, 2002.
[1] P.M. Sanderson, M.O. Watson, W.J. Russell, “Advanced
Patient Monitoring Displays: Tools for Continuous Informing”,
Anesthesia and Analgesia, vol. 101, pp. 161-8, 2005.
[14] M.J. Platt, “Heads up display,” British Journal of
Anaesthesia, vol. 92, pp. 602-603, 2004.
[2] J. Edworthy, E. Hellier, “Alarms and human behavior:
implications for medical alarms”, British Journal of Anaesthesia,
vol. 97, pp. 12-7, 2006.
[3] M. Imhoff, S. Kuhls, “Alarm Algorithms in Critical Care
Monitoring”, Anesthesia and Analgesia, vol. 102, pp. 1525-37,
2006.
[15] P.M. Sanderson, M.O. Watson, W.J. Russell, S. Jenkins, D.
Liu, N. Green, et al., “Advanced Auditory Displays and HeadMounted Displays: Advantages and Disadvantages for
Monitoring by the Distracted Anesthesiologist,” Anesthesia and
Analgesia, vol. 106, pp. 1787-97, 2008.
[4] M. Weinger, “A vision of the future of perioperative
information management”, Anesthesia Patient Safety Foundation
Newsletter, vol. 15(4), 2000.
[16] Philips Medical Systems, “IntelliVue Patient Monitor Data
Export Interface Programming Guide,” Philips Medizin Systeme
Boeblingen GmbH, Germany, M8000-9305C, 2004.
[5] N. Bitterman, “Technologies and Solutions for Data Display
in the Operating Room”, Journal of Clinical Monitoring and
Computing, vol. 20, pp. 165-173, 2006.
[17] Datex-Ohmeda Inc., “Datex-Ohmeda Output Protocols,”
Datex-Ohmeda Inc., Madison, WI, 2001.
[18] M. Imhoff, R. Fried, “The Crying Wolf: Still Crying?”,
Anesthesia and Analgesia, vol. 108, pp. 1382-3, 2009.
[6] P. Sanderson, “The multimodal world of medical monitoring
displays,” Applied Ergonomics, vol. 37, pp. 501-512.
[19] T.J. Gal, “Chapter 42 – Airway Management,” in Miller’s
Anesthesia, 6th ed., R. Miller, Ed. Philadelphia, PA: Elsevier
Churchill Livingstone, 2005.
[7] D.F. Ormerod, B. Ross, and A. Naluai-Cecchini, “Use of a
See-Through Head-Worn Display of Patient Monitoring Data to
Enhance Anesthesiologists’ Response to Abnormal Clinical
Events,” in Proc Sixth International Symposium on Wearable
Computers, 2002, pp. 131-2.
[20] M. Brady, S. Kinn and P. Stuart, “Preoperative fasting for
adults to prevent perioperative complications,” Cochrane
Database of Systematic Reviews, Issue 4 Art. No. CD004423,
2003.
[8] D. Liu, S. Jenkins, P.M. Sanderson, M.O. Watson, T. Leane,
A. Kruys, and W.J. Russell, “Monitoring with head-mounted
displays: Performance and safety in a full-scale simulator and
part-task trainer,” Anesthesia and Analgesia, in press.
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