8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 1/31
SUITABILITY STUDY ON WEIGHTLESS SUSPENSION IN OPERATING
ROOMS: A FINAL REPORT
Prepared for: Steve McMillan, Head of Medical Equipment and SuppliesStryker®
Prepared by: Clarissa Queja, Kinesiology & Health StudentAnnika Richard, Pre-Medical Student
December 9, 2004
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 2/31
College Park, MD 20742
www.umd.edu
Memo
Date: December 9, 2004
To: Steve McMillan, Head of Medical Equipment and Supplies, Stryker®
From: Clarissa Queja, Kinesiology & Health Student, University of MarylandAnnika Richard, Pre-Medical Student, University of Maryland
Subject: Final Report for the Proposal for Weightless Suspension for Operating Room
Personnel
Attached is a final report on our proposal about improving surgical equipment design foroperating room staff. We completed the tasks outlined in our proposal dated October 11, 2004:researching current surgical apparatuses and testing various options to alleviate surgeons’ lowerback pain and to increase the productivity of operating room staff.
First, we performed research on low-back pain caused by surgeons’ static posture during
procedures. Then, along with SSI Robotics®, we designed and tested several models of weightless suspension apparatuses based on standards determined from our research.
Based on the information we gathered, we recommend that the chest support-based model is thebest design for the Voyager Lift™ because it performed the best in our testing. We therefore
propose that the Voyager Lift™ with the chest support feature be incorporated into the i-Suite™ operating room design.
Thank you for the opportunity to research options for enhancing Stryker’s i-Suite™ operatingroom design, as well as helping with surgeons’ problems with low-back pain and injury. We
look forward to the possibility of working on trial installations of the Voyager Lift™ inWashington, DC area hospitals. Please contact Clarissa Queja at (301) 324-1851 or AnnikaRichard at (301) 216-0338 if you have any questions or comments.
Table of Contents
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 3/31
List of Illustrations …………………………………………………………………..…. iii
Abstract …………………………………………………………………………… ……. iv
Executive Summary ……………………………………………………………… ……. 1
Introduction ………………………………………………………………………. ……. 2
Methods …………………………………………………………………………… ……. 4
1. Performing Research ………………………………………………………. ……. 4
2. Approving Model Designs ……………………………………………………….. 6
3. Testing Models ……………………………………………………………..……. 7
4. Proposing a Final Design ………………………………………………….. ……. 10
Results …………………………………………………………………………….. ……. 11
1. Research Findings …………………………………………………………. ……. 11
2. Model Designs ……………………………………………………………………. 16
3. Model Testing Results ……………………………………………………………. 18
4. Final Design Proposal ……………………………………………………………. 19
Conclusions ……………………………………………………………………….. ……. 20
Recommendations ………………………………………………………………………. 21
Glossary …………………………………………………………………………………. 22
Appendix: Numerical Score Criteria for Testing Models ……………………………. 23
References ………………………………………………………………………….……. 24
List of Illustrations
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 4/31
Figures
Figure 2.1 Model A……………………………………………………………………. 17
Figure 2.2 Model B……………………………………………………………………. 17
Figure 2.3 Model C……………………………………………………………………. 18
Tables
Table 3.1 Model Testing Scores……………………………………………………… 18
Table 3.2 Individual Criteria Scores for Comfort and Ease of Movement and UseMeasurements……………………………………………………………….19
Abstract
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 5/31
“Suitability Study on Weightless Suspension in Operating Rooms: A Final Report”
Prepared by: Clarissa Queja, Kinesiology Student, University of MarylandAnnika Richard, Pre-Medical Student, University of Maryland
Lower back pain and injury are common among surgeons and their assistants because they mustfrequently sit or stand in non-neutral positions for long periods of time. There is a growingconcern over the short-term and long-term effects of surgeons’ poor posture while operating.This report describes a project to design a weightless suspension apparatus in the operating roomto alleviate back pain and to increase the productivity of the surgeons’ and their staff. Weresearched topics such as back pain and injury, ergonomics, weightlessness, and suspensiondevices in order to establish fundamental model-selection criteria. The models produced werethen evaluated according to the six standards. The chest support-based model (B) described inthis report was chosen as the best option to enhance hospital operating rooms. This modelallows the most movement and accuracy, is not too large to install in average size operating
rooms, and is simple to use. Based on the information we gathered and reviewed, werecommend installing the chest support-based Voyager Lift™ apparatus in the i-Suite™operating room design on a trial basis.
Keywords: weightlessness, suspension, operating room, back pain, ergonomics
Executive Summary
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 6/31
Minimally invasive surgery has become increasingly well-known in the last ten years. The
advantages for patients are well-recognized; however, surgeons must cope with disadvantages
caused by an unergonomic working environment. On October 1, 2004, we received approval to
research and test alternative surgical equipment designed to improve operating rooms’
ergonomic designs and alleviate surgeons’ back pain. In our study, we addressed these problems
experienced by many operating room personnel:
• They have dealt with low-back pain and/or injury due to prolonged improper posture
during surgeries.
• They have experienced muscle cramps and fatigue during procedures caused by
unergonomic equipment in the operating room.
This report describes a project to design a weightless suspension apparatus in the operating room
to alleviate back pain as well as increase the productivity of the surgeons and their staff.
The Voyager Lift™, a chest support-based model, described in this report best meets all our
technical and cost criteria. It is feasible because it allows the most movement and accuracy out
of the three models tested, it is not too large to install in average size operating rooms, and it is
simple to use. We recommend installing the apparatus in the i-Suite™ operating room design on
a trial basis. If the trial program proves successful, we further recommend suspension devices,
such as the Voyager Lift™, be installed in more operating rooms in the area. The Voyager Lift™
design provide the best solution to the current problems of surgeons’ low-back pain and injury,
as well as unergonomic workplaces.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 7/31
Introduction
On October 1, 2004, we received approval for funding for the production of surgical equipment
designed for weightless suspension of operating room personnel. We also received approval to
research and test alternative surgical equipment designed to improve operating rooms’
ergonomic designs and alleviate surgeons’ back pain. This proposal was based on growing
concerns over the short-term and long-term effects of surgeons’ poor posture in operating rooms.
Low-back pain is common among surgeons and their assistants because of poor ergonomic
designs in operating rooms. When a surgeon remains motionless in an overstretched or
physiologically unsuitable position for extended periods of time during a procedure,
musculoskeletal problems may occur. Prolonged sitting or standing, particularly in forward or
slouched positions, can cause muscle fatigue, which can lead to back problems. Creating new
surgical equipment, as this report recommends, would help alleviate surgeons’ back pain as well
as increase the productivity of the operating room staff.
This report presents the findings of our research and testing. We researched back pain and injury
experienced by surgeons, ergonomics in the hospital, and similar weightless suspension devices
currently being used. We designed several models of weightless suspension apparatuses and
established model-selection criteria. In conducting our research, we relied on the expertise of
several individuals knowledgeable about surgical equipment and its importance in operations.
For example, Dr. Daniel Stevenson, a general surgeon at the Anne Arundel Medical Center,
helped us understand the seriousness of prolonged improper posture while in surgical
procedures. We consulted the engineering firm, SSI Robotics®, to build and test different
models based on the results of our research. Finally, this report details our research and
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 8/31
recommends one of the models to be added to the Stryker® i-Suite™ operating room design. We
also recommend that the final model, called the Voyager Lift™, be used in other hospitals and
operating rooms.
We have focused our research on designing surgical equipment solely for weightless suspension
and use in operating rooms in hospitals. The Voyager Lift is intended for the suspension of
surgeons and other operating room personnel to alleviate back pain.
Our most significant findings are as follows:
• The terrible back pains and injuries that surgeons experience daily are caused by strain on
the lower back muscles and prolonged forward, bent motions or positions.
• A suspension device using cables or wires will allow surgeons to maintain a neutral spine
position while allowing them to perform their jobs.
• Model B exhibiting the chest support design received the best score from our model-
selection criteria.
We therefore recommend that the chest support-based model (B) is the best option to enhance
hospital operating rooms. This model allows the most movement and accuracy, is not too large
to install in average size operating rooms, and is simple to use. Based on the information we
gathered and reviewed, we further recommend installing the chest support-based Voyager Lift™
apparatus in the i-Suite™ operating room design on a trial basis. The i-Suite™ model has the
potential of being largely enhanced with the addition of the Voyager Lift™.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 9/31
The following sections provide additional details about the methods used in our research, the
results we obtained, the conclusions we made from those results, and our recommendations
based on those conclusions.
Methods
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 10/31
We performed several tasks in order to test and chose a final design for the Voyager Lift™. We
first spent some time performing research on similar lifts and machines as well as on the problem
of back pain for surgeons. Using this research, we asked SSI Robotics®
to design several models
for our suspension device. We approved or rejected each design and then chose three (3) to build
as actual models to test. Upon completion of the tests, we analyzed the data and chose the final
model for the Voyager Lift™
. A detailed description of each completed task is outlined below:
1. Performing Research
We completed research in the following areas:
1.1. Past studies on back pain and injury
The National Institute of Neurological Disorders and Stroke, working in association with
the National Institute of Health, has performed several studies on back pain and has
created a comprehensive fact sheet detailing the condition and its causes.
Further studies on lower back injury have been performed by the Statistical Analysis,
Accident Causation and Policy Monitoring Division of Great Britain’s Department of
Transport. The Workplace Safety & Insurance Board has also published data on the
causes and possible prevention of back pain and injury. Together, these reports give a
clear overview of the back problems associated with inappropriate posture.
1.2. Back pain experienced by surgeons
We interviewed several Surgeons and Occupational Therapists in order to get a first-hand
account of the problem of back injury associated with the Medical Surgery profession.
Interviews were performed with Daniel Stevenson, M.D. of Anne Arundel Medical
Center in Annapolis, Maryland, Marie Sharpe and Dr. Joshua Giovanni, M.D. of Thomas
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 11/31
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 12/31
1.5. Similar suspension devises and their mechanisms
Hospitals already have certain suspension devices for their patients, and we compared
and contrasted these different machines to determine their mechanisms. We also
researched what types of equipment different companies and agencies, such as NASA,
are using to suspend people. This information gave us good insight and ideas for the
types of designs to create for our model.
1.6. Feasibility of use in an operating room
The most important aspect of our design is its use in the operating room. We explored
the feasibility of using such a device by looking at similar machinery already used in
hospitals and their operating rooms, estimating the costs and benefits to hospitals, and
predicting the likelihood of the lift being used on a regular basis. We also considered
how the lift would improve the i-Suite™design. By carefully studying and measuring
the model, we determined how our lift would fit in with the machinery already in place
for the i-Suite™
. We also used this information to determine a size range for the
Voyager Lift™ to be incorporated into the design.
2. Approving Model Designs
Engineers at SSI Robotics®
designed several models of weightlessness suspension devices
using the structural and mechanical findings we provided from our research. We considered
each design and approved or rejected it based on standards determined from the research on
similar suspension devices. We chose three (3) final designs, which SSI Robotics®
then built
for us to test.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 13/31
3. Testing Models
Each one of the three (3) models was tested for several factors according to numerical criteria
scales. The scores for all factors were added up in the end to determine the best model
design. Each factor and the corresponding scale used are described below. A summary chart
of the numerical score criteria is shown in appendix A.
3.1. Size
The three (3) models were already chosen based on the previously determined size limits
so that the final design can be incorporated into the i-Suite™operating room.
However, each model is nevertheless different in size, and a scale was determined to
compare the different dimensions of each. We measured the length, width and height of
each device and assigned a number from 0 to 3 to each dimension.
For length and width, a zero (0) was assigned to any measurement of less than 1.0
meters (m) and more than 3.5 meters (m). A one (1) was assigned to any measurement
in the range of 1.0 m to 1.5 m or 3.0 m to 3.5 m. A two (2) was given to a measurement
in the range of 1.5 m to 2.0 m or 2.5 m to 3.0 m. A three (3) was assigned to any length
in the 2.0 m to 2.5 m range.
For height, we not only obtained a measurement, but also tested whether or not it could
be adjusted. All measurements were taken from the top, where the device would be
attached to the ceiling, down to the end of the fully extended devise. A model received a
score of zero (0) if it was not adjustable and less than 1.0 m or more than 3.0 m high, and
a one (1) if is was not adjustable but within the range of 1.0 m to 3.0 m. This range of
1.0 m to 3.0 m is most appropriate for operating room heights. A model received a
higher score of a two (2) or three (3) if it was adjustable. A two (2) was give for a short
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 14/31
range (less than 2.0 m) adjustment capability, and a three (3) for a wide range (more than
2.0 m) adjustment capability.
3.2. Weight limits
Each one of the models has a certain weight limit, indicating how heavy of a person it
can structurally and mechanically support. Because a larger weight limit allows for a
wider range of use, the scores for this category were given based on increasing values
for weight limit.
A zero (0) corresponds to a limit of less than 100 kg, a one (1) to a limit of less than 150
kg, and a two (2) to a limit of less than 200 kg. The best score of a three (3) was given
to a device with a weight support of more than 200 kg.
3.3. Comfort for surgical personnel
Comfort is a very difficult factor to test because it can be interpreted differently by
different people. We therefore asked a group of ten people to try out each devise and
rate their level of comfort based on the following scale:
(0) = Not comfortable, Hard Material, Awkward positioning
(1) = Somewhat comfortable, Semi-soft material, OK positioning
(2) = Comfortable, Soft material, Good positioning
(3) = Very Comfortable, Very soft material, Excellent positioning
The average score was then taken for each model and considered in the final score
calculation.
3.4. Type of Control for Height and Rotation Adjustment
We measured the way in which the lift can be adjusted in height (up and down motion)
and rotation (left to right motion). Models that can not be adjusted at all received a zero
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 15/31
(0). Models that can only be adjusted by manually moving a switch received a one (1),
whereas those that use a remote control received a two (2). The high score of three (3)
was given to models that have a remote control in combination with a sensor control.
The sensor control uses some type of sensory equipment to move to a specific location
on its own without hitting any other objects or people. A specific location can be
entered digitally, and the machine automatically moves into that position.
3.5. Ease of movement and use
This category is based on how smoothly the machine operates and how user-friendly it
is. Because this factor also changes for different individuals, ten people were asked
again to rate each model and give it a score according to the following criteria:
(0) = Difficult to use, Jerky movement
(1) = Fairly easy to use, Slightly jerky movement
(2) = Easy to use, Smooth movement
(3) = Very easy to use, very smooth movement
The average of these scores was taken to be used in the final score calculation.
3.6. Feasibility of use in hospital operating rooms
We measured the feasibility of using the models in operating rooms to determine if the
size, shape, and ease of use were appropriate for operating room staff. Models that were
not feasible to use received a zero (0). Models that were only suitable for very few or
some operating rooms received a one (1) or two (2), respectively, and models suitable
for use in most operating rooms received a (3). These suitability measurements are
based upon the standard sizes of operating rooms throughout the United States, as taken
from the chart of Standard Operating Room Dimensions on the Stryker® website.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 16/31
3.7. Production and installation cost (estimated per lift)
The final testing criteria involves the estimated cost for production and installation of
each lift design. The actual monetary amounts will of course vary between hospitals and
areas, but the approximate costs could be determined based on estimated material,
production and installation costs. Models that would cost over $ 3000.00 per lift
received a zero (0). Designs costing from $1500.00 to $ 3000.00 received a one (1),
while those costing between $ 500.00 and $ 1500 received a two (2). Models that would
cost less than $ 500.00 received a score of three (3). Lower costs received higher scores
because we want to minimize the cost to the Stryker®
company and to hospitals.
After completing the tests, all of the individual scores for each criteria were added together to
determine the total score for each model design.
4. Proposing a Final Design
Based on the testing results and the highest total score, the final design was chosen. This
model was then further analyzed and the cost predicted more accurately. The model is now
being proposed for approval along with this report.
Results
In this section, we present the results of our research, design approval, model testing and final
design proposal. The types of models tested, their scores from the analyses, and the final model
chosen for the Voyager Lift™
are described below.
2. Research Findings
The research we completed provided us with a lot of essential information for creating and
testing the models for the Voyager Lift™. Our findings are outlined below:
3.8. Past studies on back pain and injury
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 17/31
From studies performed by the National Institute of Neurological Disorders and Stroke
(NINDS), we learned that back pain is very common among the general population, and
most frequent among both men and women between the ages of 35 and 55. This is the
majority of the working population. The NINDS’s fact sheet further reveals that back
pain and injury are most often caused through incorrect posture, such as prolonged
sitting or bending. Surgeons certainly fall into the category of prolonged bending, as
they must constantly lean over their patients to perform surgeries. Injuries, such as
herniated disks, spinal degeneration and lumbar muscle strains, are very common
amongst people that stand in improper and bent positions for extended periods of time.
Similar conclusions were drawn by the Division of Statistical Analysis, Accident
Causation and Policy Monitoring (SAP) of Great Britain’s Department of Transport.
Although this data comes from the Department of Transport and focuses mainly on back
injuries caused through automobile accidents, it does provide good insight into what
causes these injuries. According to the SAP Division, most accident related back
injuries are caused by strain on the lower back muscles and the forward, bent motion of a
passenger in a car crash. The similarly bent positions for surgeons are what cause their
lower back pains and injuries.
The most comprehensive study on occupations that contribute to back pain and damage
was performed by the Workplace Safety & Insurance Board. Medical Surgery is listed
amongst the list, along with similar professions that require frequent bending, such as
dentistry and auto mechanics.
From these results on past studies, it becomes clear that back injury is a common problem
among surgeons, and that this problem needs to be addressed.
3.9. Interviews with surgeons
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 18/31
To support our findings on the back pain experience by surgeons, we interviewed actual
surgeons and discovered that they do, in fact, suffer from frequent back pain as a result
of their profession. Daniel Stevenson, M.D. of Anne Arundel Medical Center said: “I
have been performing surgeries for 7 years...[and] the back pain is excruciating.” Dr.
Joshua Giovanni, M.D. of Jefferson University Hospital also expressed that “if you have
a weak back, you should consider going into a different field [other than surgery] of
medicine”, suggesting that the there is a lot of strain on surgeons’ backs. Both of the
doctors expressed that they have felt back pain for several years and that they frequently
(at least once a day) feel this pain. They believe that the pain is most likely a result of
their profession, which they have been in for seven years in the case of Dr. Stevenson
and nine years in the case of Dr. Giovanni. When we asked the surgeons what they
would think of a device such as the Voyager Lift™
, they both expressed positive attitudes
towards the idea. Dr. Stevenson even said: “I [wish] someone had come up with the idea
of a lift for surgeons sooner.”
We also interviewed Occupational Therapists, who gave us more information on how
back pain is caused and how it can be prevented. Marie Sharpe, of Thomas Jefferson
University Physical and Occupational Therapy, told us from her own experience with
different patients that surgeons are at the highest risk of developing back injuries out of
all medical professions. She also restated the fact that most back injuries are caused by
standing in improper positions, such as bending forward, for long periods of time.
Ashley Henderson, of Greenbelt Physical Therapy, further supported the statements
made by Mrs. Sharpe and said that “backs are nothing to be fooled around with. You
need to keep your spine in a neutral position at all times to prevent back pain and injuries
from happening.”
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 19/31
As a result of all of these interviews, we concluded that back pain and injuries are major
concerns for surgeons. We also concluded that in order to prevent this pain, surgeons
need to maintain a neutral position for their spines.
3.10. Ergonomics in the hospital, particularly the operating rooms
The idea of a neutral spine position relates directly to ergonomics, which focuses on
providing working environments that allow for optimal body posture while performing a
job. Ergonomics in the operating room is a topic that is increasingly being discussed. To
establish model-selection criteria, we researched operating room design factors because
they greatly influence surgeon fatigue and discomfort during procedures. One of the
main and basic ergonomic factors associated with surgery is the surgeon’s non-neutral
posture during procedures, which causes lower back pain. Many factors contribute to the
surgeon’s posture, such as instrument design, a poorly adjusted operating table height,
and the static body position. This information gave us insight into basic design features
of surgical equipment to create for our model.
3.11. Physics of weightlessness and suspension
Any type of mechanism needs to take into consideration the physical aspects of the
device. In physics, weightlessness refers to the notion of something that is apparently
floating without the weight (due to gravity) having an effect on the object or person.
This generally occurs in the case of something falling with the same acceleration as the
object in which it travels. An example would be an astronaut “floating” in a spaceship
orbiting the Earth.
The concept of suspension is more accurate for our purposes. Suspension, in the physics
sense, refers to a device that can exert a net force on a person or object that equals (in
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 20/31
magnitude) the weight of that person or object due to gravity. The Voyager Lift™ would
therefore need to be supported by strong cables or wires, for instance, so that the tension
in these wires could counteract the forces due to gravity and support the weight of the
device and person on it.
Knowing these definitions of weightlessness and suspension, as well as the physics
concepts behind them, greatly assisted us in developing designs for the Voyager Lift™.
3.12. Similar suspension devises and their mechanisms
We further developed design ideas after looking at similar lifts and suspension devices.
NASA, for example, uses suspension equipment as a part of their astronaut training. In
order to simulate the “floating” experienced in outer space, the Special Hoist Supported
Personnel Lifting Devise pulls up people and allows them to hang in mid-air.
Similar to the NASA suspension apparatus, Hollywood has used the famous Mission
Impossible style suspensions to allow actors and stuntmen to hang from ropes and wires.
This type of suspension could certainly be emulated.
Other types of lifts already exist as well. Hospitals throughout the nation are familiar
with the Hoyer™ lift, which is used to hoist up injured, elderly or overweight people
who cannot stand or sit up by themselves. There are many versions to the lift, some of
which are operated by a manual switch and others that are operated electronically.
Because hospital employees are already familiar with such types of lifts, they would
most likely be more accepting of the concept of lifting surgeons during long surgical
procedures.
3.13. Feasibility of use in an operating room
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 21/31
While hospital staff are familiar with lifts and would most likely support the idea behind
the Voyager Lift™, the machine itself must be feasible for use in the operating room.
The Voyager Lift™ should not be too expensive for the hospitals to purchase. Machines
that exceed $3000.00 would be of little benefit for hospitals. However, with the money
the hospitals can save in worker’s compensation for back injuries and the advantage of
happier and more productive employees, hospitals could certainly gain benefits from
purchasing a Voyager Lift™. The benefits will exceed the costs if the lift can be bought
and installed for under $ 3000.00.
Once installed, we believe that the lifts would be used on a regular basis. Our interviews
with the surgeons (see Results Section 1.2) also support this assumption. The lift would
be most beneficial for surgeons during long procedures, such as cardiac and brain
surgeries, which generally last from three to eight hours. The Voyager Lift™ would
therefore be very feasible to use in hospitals specializing in these types of surgeries.
Other operating rooms would be enhanced with the Voyager Lift™, as well. As part of
the i-Suite™design, the lift would greatly enhance the operating room model. The space
above the operating table is approximately 3.5 meters wide by 3.5 meters long. The
Voyager Lift™, with the proper dimensions, could certainly fit into this space. Our lift
design could therefore be easily incorporated into the i-Suite™model.
Using all of these research results, we concluded that we certainly needed to develop a device
that would allow surgeons to maintain a neutral spine position while allowing them to
perform their jobs. We also concluded that we should develop a type of suspension using
cables or wires and that the device should be fairly easy to operate. The cost of production
and installation should also not exceed $ 3000.00 per lift. Furthermore, we concluded that
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 22/31
the Voyager Lift™ could be incorporated into the i-Suite™ model to greatly enhance the
design.
4. Model Designs
All of the information gathered through research (Section 1, above), was submitted to
engineers at SSI Robotics®, who designed several models of suspension devices using the
structural and mechanical criteria we provided for them. They developed 25 designs, out of
which the three (3) best were chosen to be build and tested. The blueprints of these three
models (A, B and C) are shown below.
2.1 Model A:
Model A uses a
mattress-type
of suspension.
A memory
foam patting
allows for
comfort for the
surgeon, and
the remote
controlled
operationallows for
smooth and
easy
movement.
Model 28Z5
Simple Suspension DeviceAdjustable planeFree 180°RotationAdjustable height
Six Supporting CablesCeiling Mounted SupportsMemory Foam MattressRemote Controlled
Model 28Z5
Simple Suspension DeviceAdjustable planeFree 180°RotationAdjustable height
Six Supporting CablesCeiling Mounted SupportsMemory Foam MattressRemote Controlled
2.3 Model B:
Model B uses a
design similarto Model A in
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 23/31
2.3 Model C :
Model 28A6
Suit SuspensionCustom FitHooks Attached to Back of SuitDurable Wire Support360°Rotation
Model 28A6
Suit SuspensionCustom FitHooks Attached to Back of SuitDurable Wire Support360°Rotation
Model C is
most similar toNASA’s
suspension
device and the
Mission
Impossible-
style
suspension. It
consists of
suits that can
be custom fitfor surgeons.
Hooks on the
back and legs
5. Model Testing Results
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 24/31
The three (3) designs shown above were tested according to the criteria shown in Appendix
A and explained in the methods section (methods 3.1 to 3.7). Below is a chart of our results,
with the appropriate scores for each model shown. Model B has the largest total number of
points.
Table 3.1: Model Testing Scores
Criteria Model A Model B Model C
Length2 3 2
Width 2 3 2
Height 3 3 2
Weight Limit 2 3 2
Comfort for Surgeon* 2 1.8 0.5
Type of Control for Adjustment 2 2 1
Ease of Movement and Use* 1.5 1.8 0.9
Feasibility of Use in the OR 3 3 3
Production and Installation Cost
(per lift)
2 2 3
TOTAL 19.5 22.6 16.4
*Two of the criteria—comfort for surgeon and ease of movement and use—are averages
taken from 10 different people’s opinions on how comfortable and easy to use each
model is. The individual scores are as follows:
Table 3.2: Individual Criteria Scores for Comfort and
Ease of Movement and Use Measurements
Comfort for Surgeon 1 2 3 4 5 6 7 8 9 10 avg
Model A 2 2 1 2 2 3 1 2 2 3 2
Model B 3 2 2 1 1 1 2 2 2 2 1.8
Model C 0 0 1 0 1 1 0 2 0 0 0.5
Ease of Movement and Use 1 2 3 4 5 6 7 8 9 10 avg
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 25/31
Model A 2 1 1 0 2 3 1 2 1 2 1.5
Model B 1 2 2 2 1 3 2 1 2 2 1.8
Model C 1 0 1 0 2 1 0 1 1 2 0.9
These averages were used in the calculation of the final score.
As shown in the chart, model B, with a score of 22.6 out of 27 possible, has the highest
total score, followed by model A with 19.5 points, and then model C, with 16.4 points.
4. Final Design Proposal
Based on the testing results shown above in section 3, model B, with the chest support, is the
best design for the Voyager Lift™ because it performed better with the testing than the other
models did. We therefore propose that model B be incorporated into the i-Suite™ operating
room design. The i-Suite™ model has the potential of being largely enhanced with the
addition of the Voyager Lift™
Conclusions
After carefully analyzing the three models of weightless suspension apparatuses and the model-
selection criteria, we have concluded that Model B of the Voyager Lift with the chest support
suspension is the best option to enhance the i-Suite™ operating room design. The standards we
created stipulate that the apparatus have the following qualities:
• ideal dimensions
• comfort for the surgeon
• easy adjustment control unit
• moderate feasibility for use in operating rooms
• cost for production and installation per unit lift not to exceed $3000
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 26/31
This Voyager Lift™ model received excellent ratings from SSI Robotics® engineering experts
and local surgeons for its size and dimensions, weight limit, and feasibility of use in operating
rooms. This model is also a remote controlled apparatus, which is a moderately easy type of
control for adjustment and movement for the operator. Finally, the Voyager Lift™’s production
and installation cost is very reasonable.
The ideas of suspension and ergonomics in operating rooms have been established in current
literature and have been deemed suitable for surgeons and operating rooms. We recommend that
the Voyager Lift be incorporated into the i-Suite™ operating room design. Moreover, the i-
Suite™ operating room has the potential of being largely enhanced with the addition of the
Voyager Lift™.
Recommendations
We recommend that the chest support-based model of the Voyager Lift™ is the best option to
enhance hospital operating rooms and ease surgeons’ lower back pain. Based on the information
we gathered and assessed in this study, we further recommend installing the Voyager Lift™
apparatus with the chest support feature in the i-Suite™ operating room design on a trial basis.
We believe the i-Suite™ design will be largely enhanced with the addition of the Voyager Lift™
apparatus. If the trial installation is successful, we further recommend that hospitals in the
Washington, DC area put in i-Suite™ operating rooms with the Voyager Lift™ included in them.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 27/31
In addition, the Voyager Lift™ could be slightly altered and used in other professional fields,
such as dentistry or automobile mechanics. The possibilities for the Voyager Lift™ are endless.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 28/31
Glossary
herniated disks: the protrusion of a degenerated or fragmented intervertebral disk into theintervertebral foramen, compressing the nerve root
lumbar muscle: the muscle of, near, or situated in the part of the back and sides betweenthe lowest ribs and the pelvis
lumbar strain: also known as low back strain, an injury to the large muscles in the lowback
spinal deterioration: known as spondylosis, degeneration of the spinal column, especiallya fusion and immobilization of the vertebral bones
occupational therapist: a person trained in or engaged in the practice of occupational
therapy, the use of productive or creative activity in the treatment or rehabilitation of physically or emotionally disabled people
neutral (spine) position: the position of an individual's spine where every joint is held inan optimal position to allow an equal distribution of force through the entire structure
Weightlessness (Physics): the state or condition of having little or no weight
Suspension (Physics): the act of suspending something (hanging it from above so itmoves freely)
Tension (Physics): the condition of so being stretched; tautness; a force tending to stretchor elongate something
Hoyer lift: Patient lifts that allow an individual do be lifted and transferred with minimaleffort and greater safety. Some of the main reasons for selecting a Hoyer lift include:Patient too heavy to be transferred without assistance of a lifting device; to preventinjury to the caregiver or the patient during transfers; and the ability to lift patientsfrom the floor
Ergonomics: the applied science of equipment design, as for the workplace, intended tomaximize productivity by reducing operator fatigue and discomfort
Special Hoist Supported Personnel Lifting Device: Device specifically designed to liftand lower persons via a hoist. These devices include hoist supported platforms wherepersonnel occupy the platform during movement.
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 29/31
Appendix A
Numerical Score Criteria for Testing Models
Numerical ScoreFactor
(x) 0 1 2 3Length x < 1.0 m
x > 3.5 m1.0 m < x< 1.5 m3.0 m < x< 3.5 m
1.5 m < x< 2.0 m2.5 m < x< 3.0 m
2.0 m < x < 2.5 m
Width x < 1.0 mx > 3.5 m
1.0 m < x< 1.5 m3.0 m < x< 3.5 m
1.5 m < x< 2.0 m2.5 m < x< 3.0 m
2.0 m < x < 2.5 m
Height(fromceiling)
Not Adjustable,x < 1.0 mx > 3.0 m
Not Adjustable,1.0 m < x< 3.0 m
Adjustable,Short range
(within 2.0 m)
Adjustable,Wide range
(more than 2.0 m)
Weight Limit x < 100 kg x < 150 kg x < 200 kg x > 200 kg
Comfort forSurgeon Not comfortable,Hard Material,Awkward
positioning
Somewhatcomfortable, Semi-soft material, OK
positioning
Comfortable, Softmaterial, Goodpositioning
Very Comfortable,Very soft material,Excellent
positioning
Type of Control forAdjustment
Adjustment NotAvailable
Switch Control Remote Control Remote andSensor Control
Ease of Movementand Use
Difficult to use,Jerky movement
Fairly easy to use,Slightly jerky
movement
Easy to use,Smooth movement
Very easy to use,Very smoothmovement
Feasibility of Use in theOR
Not Feasible Feasible in a fewOperating Rooms
Feasible in someOperating Rooms
Feasible in mostOperating Rooms
Production +InstallationCost (per lift)
x > $ 3000 $1500 < x <$ 3000 $500 < x <$ 1500 x < $ 500
8/3/2019 Suitability Study On Weightless Suspension In Operating Rooms
http://slidepdf.com/reader/full/suitability-study-on-weightless-suspension-in-operating-rooms 30/31