Session C1
2218
TARGETED MUSCLE REINNERVATION
Robert Decker (rwd14@pitt.edu), Luke Schmidt (lcs41@pitt.edu)
Abstract - Targeted Muscle Reinnervation (TMR) is a
surgical procedure intended only for arms that moves
the four major arm nerves from the shoulder to four
separate muscle groups in the chest. The electrical
impulses from the brain to the arm are detected by
four electrodes that are connected to separate chest
muscle groups. The signals are then sent to the arm
and are interpreted by a microprocessor in the arm,
creating movement by the prosthetic arm. After the
procedure, the patient is given time to heal. When
healing is finished, they go through multiple sessions
of physical therapy to strengthen the chest muscles
that the arm nerves are now attached to. After
therapy, the patient is fitted with the prosthetic arm,
ending the process. This has significant impact on the
lives of those who have lost their arm(s). This is
specific to U.S. Armed Forces veterans. The surgery
and prosthetic arms restores many functions to
wounded veterans.
This paper will provide information on a
specific prosthetic limb technology called targeted
muscle reinnervation (TMR). The qualifications that
determine eligibility will be outlined. Additionally the
techniques used during the surgical procedure,
specifically the movement and reconnection of the
nerves, the timeline for recovery, the physical therapy
involved in the rehabilitation process, and the
acquisition and sizing of the prosthetic will be
discussed and assessed. Also, the ethical issues of
having this procedure done, and the practicality of
the prosthetic will be discussed in regards to recent
amputees in the US armed forces.
step in solving this problem. In the past, users were
only able to perform a single action at once (such as
moving the elbow, then moving the wrist, etc.) with
unnatural commands. TMR allows the user to move
all of those parts with natural brain commands
seamlessly [2]. This allows the user to perform more
tasks in a shorter period of time as well as be more
comfortable in performing those tasks.
What is Targeted Muscle Reinnervation?
TMR is a process that was founded by Dr. Todd
Kuiken. His first TMR procedure was done in 2006
and was successful [3]. There was an immediate
improvement in movement when compared to other
prosthetic limbs, outperforming them on standardized
tests by more than 250%. TMR is a procedure that
moves four unused arm nerves from the shoulder to
unused muscles in the chest. The four unused arm
muscles have no function because there is no arm for
them to control. The unused chest muscles are unused
because they are the muscles that would have been
used to control the arm if it was present [2]. This
makes it an obvious choice for this type of procedure.
From here, electrodes from the prosthetic arm pick up
the electrical signals at the nerves sent from the brain
to the nerves. These signals are then interpreted by a
microprocessor in the arm, which results in
movement by the arm [2]. The movement of the
nerves and reinnervation of the chest muscles are
why this procedure is a clear advancement in
prosthetics. They allow the user to move the
prosthetic arm like it was their own regular arm.
Key words – Muscles, Nerves, Physical therapy,
Prosthetic arm, Targerted Muscle Reinnervation
(TMR)
TARGETED MUSCLE REINNERVATION AT
A GLANCE
TECHNOLOGY
Every year, roughly 10,000 people in the United
States lose their upper extremities [1]. Over the
course of the last ten years or so, our society has been
trying to solve the problems of how to restore
complete functionality of a lost limb to an amputee.
While there were solutions to this problem, they were
awkward and inefficient for the user. Targeted
Muscle Reinnervation (TMR) has taken an important
The prosthetic arm used in TMR (myoelectric arm) is
a piece of technology that combines bioengineering,
mechanical engineering, computer engineering, and
electrical engineering. Each engineer has their own
roles in this product. Mechanical engineers are
involved in the actual mechanics of the arm.
Electrical engineers handle the electrical interactions
that take place and power the arm. Computer
University of Pittsburgh
Swanson School of Engineering
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February 10, 2012
Robert Decker
Luke Schmidt
engineers complete the interaction between the body
and the arm by making sure that the microprocessor
in the arm works. Bioengineers are present to make
the arm work like a regular human arm would. The
interaction between the arm and body are short, but
very effective. It starts with the brain sending the
electrical impulses down through the nerves to the
endings that are attached to the chest. From here,
electrodes from the arm to the chest detect the signals
and relay them back to the arm. The signals are then
interpreted by a microprocessor. The microprocessor
then sends out commands to each part of the arm,
turning a motor, resulting in the motion by those
specific parts [2].
EMGs and send them to the microprocessor in the
arm. The microprocessor then redirects the signals to
the corresponding part that the signal was meant to be
sent to. A small electric motor, powered by a
rechargeable battery stored in the arm, is then turned
on, moves the specific part, and then shuts off [1].
The EMGs also play an important part in regard to
fitting the arm to the person. During and after
physical therapy, the patient has a surface
myoelectrogram done. The surface myoelectrogram
has several electrodes are laid out over the patient to
detect where the EMGs are being given off and how
strong they are [2]. The layout of the electrodes can
be seen in the following image:
HOW THE ARM WORKS
The myoelectric arm is a 20-32 pound device that
combines many aspects of engineering and
technology [1]. It works by detecting small
electromyographic (EMG) signal in the body and
processing it in the arm. This can be seen in the
following image.
FIGURE 2
IMAGE OF WHERE ELECTRODES OF A SURFACE
MYOELECTROGRAM ARE PLACED [2]
In this patient’s particular case, this step of the
procedure was done six months after surgery. This
was when her chest muscles had been strongly
reinnervated. However, not every amputee can use a
myoelectric arm. The patient must be able to produce
a strong enough EMG for the arm to detect. Also, the
patient must be able to separate muscle contractions
[1]. This means that the patient must be able to
contract one muscle while they relax the opposite
muscle. If they can’t contract and relax opposing
muscles, then the arm can’t do anything. This is
because the arm must pick up two different EMG
signals for an action to be performed. If they can’t
produce a contraction and opposite relaxation, then
the arm is moving a specific piece one way and the
opposite at the same time, resulting in zero motion
[1]. The only exception to the motion driven by EMG
signals is the control of the wrist. The patient controls
and rotates their wrist by applying pressure to a
FIGURE 1
DIAGRAM OF THE CONNECTION BETWEEN THE ELECTRODES IN
THE BODY AND THEIR CONNECTION TO THE MICROPROCESSOR
[4]
Each EMG signal is created by a small chemical
reaction in a muscle when the particular muscle
flexes or contracts after the brain sends out a
command to the particular muscle. The EMG signals
range from five to 20 microvolts, or about
1/1,000,000 the power needed to power a light bulb
[1]. From here, the electrodes over the chest (the area
where the muscles were reinnervated) detect these
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Luke Schmidt
specific area where the arm and the shoulder meet.
There is a pair of pressure switches where the
shoulder and prosthetic meet that sends signals to the
arm’s microprocessor when they have extra pressure
put on them [2]. You can see the specific function of
each nerve and pressure plate in the following image.
water causes the electrical circuit to short out, making
the arm completely useless.
CLINICAL PROCEDURE
TMR is a clinical process that moves nerves from the
site of the amputation to reinnervate unused muscles
in the chest. Ultimately, this allows the user’s
electrical impulses generated in the user’s brain to
control a myoelectric arm. The clinical procedure for
TMR is a long, extensive one, even though it follows
many of the steps that are used in typical bodyaltering procedures. These steps are as followed:
FIGURE 3
1.
2.
3.
4.
5.
THIS FIGURE SHOWS SIX BASIC FUNCTIONS AND THEIR
CONTROL SOURCE [2].
TECHNICAL BENEFITS OF THE MYOELECTRIC
Qualifying for TMR
Surgery
Recovery
Physical Therapy
Fitting/adjusting the prosthetic
ARM OVER OTHER PROSTHETIC ARMS
The timeline and details of each step varies and will
be detailed and evaluated in the following
subsections.
When the patient gets fitted for their arm, they
acquire a device that is going to benefit them greatly.
There are several benefits to having a myoelectric
arm as opposed to a regular prosthetic because of its
technical abilities. The myoelectric arm, because its
motion is powered by small electric motors, has a full
range of motion [1]. This means that the arm can
move in any direction that the normal human arm
would, and also includes finger motion too. Also, it is
a lot simply to operate when compared to basic
prosthetics. For the myoelectric arm, the user must
simply contract or flex a muscle for the arm to
perform a certain movement [1]. For a regular
prosthetic arm, the user must perform complex
motions for the arm to move [2]. The arm is also built
with a natural looking frame, which allows the user
to put a latex or silicon layer over the arm to give it
the appearance of having skin. Over time, stress on
the arm will lead to deterioration of the artificial skin
layer, resulting in the user replacing the artificial skin
several times over the course of the device’s lifespan
[1]. This eliminates the need for the user to have a
separate arm that is used in public strictly for
cosmetics. One important disadvantage is that repairs
for a damaged arm are expensive [1]. This is because
of all of the complex electrical machinery in the arm.
The user must be extremely cautious around water,
especially tap water. This is because of the ions in the
Qualifications for TMR
Not all amputees are eligible for TMR. There are
several qualifications for TMR because of what parts
of the body that the surgery uses. These qualifications
include:





Passing a medical examination
Amputation above the elbow or at the
shoulder within the past ten years. Five
years or less is ideal.
Must not have been amputated from birth
defect
Can’t have nerve degeneration, damage, or
be paralyzed.
Children must be older than 14 and be over
a minimum weight requirement
Each of these requirements has specific reasons. Each
patient must go through a rigorous medical exam to
make sure that the patient can be operated on [5]. The
examination is done through their medical records
and interviews. An amputee must have had their
amputation in the ten years before TMR because any
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time longer than ten years results in the nerves
becoming unusable. The amputation must also not
come from a birth defect because that means there are
no nerves present for the surgeon to work with,
completely blocking any type of reinnervation. The
same reasons apply to those who have nerve damage,
nerve degeneration, or paralysis [5]. Getting medical
clearance can take one to two months, depending on
when the medical records arrive [5]. Once a patient is
cleared medically, the patient must go through a
financial step. The patients must go get insurance for
the procedure and the prosthetic arm. This can take
anywhere from two weeks to six months, depending
on their insurance plan. A patient must also be able to
pay their portion of expenses created by the hospital
bill as well as equipment costs [5]. When the surgeon
receives the insurance approvals, the patient must
then decide on whether they would like to proceed
with the procedure. They must consider the physical
risks and benefits of the procedure, the financial
costs, and their level of commitment to rehabilitation.
When the decision has been made to advance with
the procedure, the patient must schedule for surgery.
Once surgery is scheduled, an ethics committee must
give approval. The patient must also provide written
consent. At this point, the risks are also made clear.
They include ‘permanent paralysis of the targeted
muscle, the return of phantom limb pain,
development of painful neuromas, as well as the
general risks of surgery’ [5].
under the clavical) of the pectoralis muscle. The
musculocutaneous nerve is also sewn to the lateral
motor nerve of the same part of the muscle [1]. The
median nerve is then split and half and coapted to
two motor nerves of the sternal part of the pectoralis
muscle. The radial nerve was completely sewn to the
long thoracic nerve to reinnervate the distal slips of
the serratus anterior muscle. These nerves are moved
and placed on these regions of the pectoralis
specifically to reinnervate those muscles so that the
arm can detect the electrical impulses sent to each
region. You can see which nerve connects to each
specific part of the pectoralis as well as the branch of
the radial nerve that connects to the remaining
triceps.
FIGURE 4
A DIAGRAM OF WHERE THE ARM NERVES ARE CONNECTED TO
IN THE CHEST [2]
After the reinnervation of the muscles, two
subcutaneous fat regions over the clavical head of the
pectoralis muscle and serratus muscle were thinned
over an area of disks with a four centimeter diameter.
This is done so the surface electromyogram can
detect the electrical impulses more effectively. After
this, a drain is placed. The surgery is then completed
once the wounds are closed, which is done in layers.
Two days later, the drain is removed. Two days after
that, the patient is sent home. The patient was
continuously monitored for wound problems, pain,
and the initial development of reinnervation through
telephone calls when the patient returned home.
Surgery
After getting cleared for surgery, the procedure
continues. The patient is put under general anesthesia
and is not given a muscle relaxer. The surgeon
begins by reopening the incision from the amputation
surgery. The mesculocutaneous, median, ulnar, and
radial nerves are identified by their branching
patterns. Depending on how much of the arm is left
from the amputation, certain branches may be
preserved to retain function to those parts. In one
specific case, a branch of the radial nerve was
connected to the remaining piece of the triceps. That
branch was preserved. Any nerves that are branching
into other muscles are then identified and removed so
that the surgeon can use the nerves properly. From
here, the ulnar nerve is sewn to the motor nerve of
the medial half of the clavicular head (the part just
Recovery
After the surgery the patient is may experience a
transient recurrence of or increase in phantom limb
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pain [6]. It is for this reason that the patient was
continuously monitored for wound problems, pain,
and the initial development of reinnervation through
telephone calls when the patient returned home. The
wounds are needed to heal for any discomfort in
motion will hinder the patient in later stages as well
as the likelihood for the accidental reopening of
wounds if they are not to heal correctly. The
strengthening of reinnervated muscles is vital so the
muscles can generate electrical signals that will later
on be detected by surface electrodes. The patient was
monitored for until the wounds were healed. This
enables the patient to begin exercises to strengthen
the muscles.
evenly. Since there is no limb to apply resistance to,
as the program progresses, only the duration of
contraction and number of repetition of sets increase.
This enables the muscles to increase in strength
without the use of weights or any resistance, since
neither are applicable for the program. The patient
will follow this program until around 3 to 5 months
after surgery. It is at this time that the patient will
start a different program that favors exercises that
isolate each target muscle. This is necessary so that
each of the prosthetic functions can be accessed with
more ease. Since the workouts are done without an
arm, some workouts can be challenging for patients.
The following are a number of actions that patients
could use to help visualize the workout and what
muscles are used.
Physical Therapy
1.
Each nerve contains numerous motor neurons. These
motor neurons control numerous muscle fibers that
work in conjunction to create a variety of peripheral
nerve actions [6]. In other words, each nerve controls
certain motions of the arm. It is uncertain which
nerve fibers will reinnervate the muscles. If not all of
the nerve fibers reinnervate the muscles equally, only
a fraction of the muscle actions will be applicable by
the patient. Thus the patient is asked to perform all of
the actions that are controlled by the nerves involved
in the process. Approximately 3 weeks after the
surgery the occupational therapist (OT) instructs the
patient to move each of the missing limb joints daily.
These movements will promote brain and nerve
pathways as well as prepare the patient to recognize
the signs of reinnervation [6]. The first signs of
reinnervation usually are seen or felt around 10 or 15
weeks after the surgery [6]. These signs are typically
something small such as a twitch or small movement
of the muscle. But, it is not until the muscle is
completely reinnervated that the strengthening
process can be initiated. The patient must have full
reinnervation of the muscles being that if
strengthening were to being before fully reinnervated,
uneven innervation may occur. As stated before, this
could result in the impairment of some actions of the
muscles. The target muscles must be strengthened by
exercises that cause maximal contraction of the
muscles for maximized results. For every nerve that
is incorporated in the movement of the arm, there is
an exercise that should be incorporated into the
muscle exercise program so that all are strengthened
2.
3.
4.
5.
6.
Perform the exercise with the intact arm and
hand. Bilateral activation can help focus the
desired movements.
Isolate elbow extension. Try a push-up on a
chair seat or arm with the intact limb.
Use a table mirror and watch the intact limb
do the exercises while exercising the nerve
transfers.
Visualize lifting, squeezing, pushing,
hitchhiking, writing, turning a door knob,
and wielding a hammer. The OT can
encourage the patient to invent his or her
own “virtual” activities and make these the
cues for the movements.
Use the intact hand to feel for the muscle
contraction/relaxation. The target muscle
should feel soft upon relaxation. The OT can
try to localize the contractions and use this
tactile feedback with the patient.
Use a table mirror to observe soft tissue
movement during contractions.
Doing these things can help encourage the
appropriate action from the patient, thus causing the
exercises to be more effective. The patient is also
instructed in the basics for self-care with and without
a prosthesis arm. It usually takes 3 to 6 months for
the muscle to be equipped for functional TMR. Until
this time, the patient uses a prosthesis that is not
controlled by the transfer site. The use of a prosthesis
arm during this time is highly recommended for
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doing so will help the patient adjust to the TMR
device more readily.
was a performance boost by over 250% when
compared to conventional myoelectric control. This
can be seen in the following image.
Fitting the Arm
The success of the fitting depend s on the ability of
the patient to be able to isolate the nerve signals. The
OT has the patient describe as accurate as possible
what they are feeling by demonstrating with their
intact arm. The OT must know what movement
yields the highest nerve signal for the arm will detect
these signals and transfer them to movements. Thus
the stronger and more isolated the EMG signal is, the
arm with react more accordingly. When the EMG
signals are adequate, the patient begin to be fitted
with the arm. A prosthetist fit the patient with a
diagnostic socket. This socket independent
myoelectric controls to carry out four actions: elbow
extension, elbow flexion, opening of the hand, and
closing of the hand. Training begins with all four
functions by having the patient carry out multiple
movements. Frequent adjustments to electrode gains,
EMG thresholds, and electrode location in the socket
are necessary and are done by the prosthetist. When
the team of professionals agree that the controls a
sufficient, the patient is sent home. Regular meetings
are schedule every few days to make sure everything
is working adequately. When the patient displays full
control and comfort with the four controls, a linear
transducer pull-switch is introduced for wrist
rotation. Now the user is asked to carry out numerous
combinations of the movements and is encouraged to
move faster if possible.
FIGURE 4
STATISTICS SHOWING THE PERFORMANCE BETWEEN
CONVENTIONAL MYOELECTRIC PROSTHETICS AND TMR
PROSTHETICS [2]
The patient’s performance in the block test was also
four times faster when compared to the original
prosthetic. The patient is also asked to perform
certain household tasks as a part of their tests. These
tasks start as making sandwiches to ironing laundry
in the beginner phase of these tests. They then
increase in difficulty to preparing, making, serving,
and cleaning up a full meal. Those test results were
greatly better than those results of patients using
conventional myoelectric arms. Aside from the test
results, one specific patient gave testimony to her
specific use of her arm. According to the patient, she
was very pleased with the cosmetic result of the
surgery when compared to her conventional
prosthetic. She was also enthusiastic about her
improved functionality and how simple it to move
her arm. She made the transition from using the
original prosthetic on a regular basis to using it only
once or twice a month. The reason for the decrease in
use of her original prosthetic was due to the level of
frustration created from her lack of functionality in
her TMR myoelectric arm. With regard to her new
prosthetic, she said, “I just think about moving my
hand and elbow and they move.” This is clearly a
significant improvement over traditional prosthetics
and non-TMR myoelectric prosthetics because
instead of performing awkward actions to get the arm
to move, it is done by simple muscle flexes. At the
Clinical Results
There are several results that show that TMR is a
large improvement over traditional prosthetic arms.
The standard test to measure how effective the
prosthetic arm is called a box and blocks test. This
test consists of taking 2.5 cm blocks, moving them
over a 10 cm wall, and placing them into a box. The
test was modified for the TMR patient by increasing
the patient’s time to perform the task, allowing the
patient to practice the test for several minutes until
they were comfortable, and allowing her breaks that
were several minutes long between each try. There
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time of her interview, the patient was using her arm
on an average of four to five hours a day for five to
six days a week. She used her arm mainly for
functional tasks such as cooking, putting on makeup,
household chores, and cosmetics. Even though she
may not be using her arm all the time, she was able to
do the things she was able to do before her
amputation. The user may not always be using their
arm, but that’s because of some of the limitations that
the arm presents. However, when the user is using
their prosthetic, they are nearly at 100% functionality
when compared to a regular arm.
FIGURE 5
THESE ARE THE STATISTICS OF AMPUTEES FROM O PERATION :
IRAQI FREEDOM AND OPERATION : E NDURING FREEDOM [7]
These numbers aren’t going to be slowing down
anytime either, as the opposing forces are creating
larger, more powerful bombs [8]. This results in more
troops becoming amputees. For example, in
Afghanistan in 2009, the total number of amputees
was 23. The total number of amputees rose to 73 in
2010, and finished over 77 in 2011 [9]. These are all
men and women who have been through a personal
tragedy. The myoelectric arm can help them cope
with their loss. These men and women get the
procedure done at either Brooke Army Medical
Center at Fort Sam Houston in Texas, or the Walter
Reed Army Hospital in Washington, D.C [8]. The
amputees can begin to do some of those everyday
activities they were doing before the amputation.
Some of those activities include preparing food,
making a meal, cleaning up after the meal, and other
household chores. Obviously these are everyday
actions that we take for granted, but for our veterans,
this is incredibly important. All mental effects aside,
this allows them to take a huge step back to their
normal lives. The pros of this arm far outweigh the
cons. Any arm that can provide the full range of
motion that any normal arm can is incredible. A piece
of technology that can let the user regain the ability
to hug their loved ones, shake the hands of others,
and even hold their children is unmatched by any
other piece of technology. Also, it is very natural
looking. This can be seen in the following image.
ETHICS
The effect that the myoelectric arm has on society is
great and has potential to improve the views or
people on medical technology. Before TMR, if a
person were to lose an arm, they could use a
prosthetic arm that was incredibly difficult to use. It
also had an extremely limited choice of functions.
TMR provides the patient the means to move closer
to having the life that they had before. At a time
where the growing population and two wars means a
growing amount of amputees in the United States, the
demand for advanced prosthetics has never been
higher. In the following subsection, we will
specifically focus on the effects that the myoelectric
arm has on our heroes, the returning veterans from
Iraq and Afghanistan.
Effects on Amputees
Amputees have lost many abilities with the loss of a
limb, in this case an arm. The multiple functions of
the arm are no longer applicable to them, but with
TMR, many of these functions and abilities are given
back to amputees. The fact that an arm can be
replaceable will help many people return to their
normal lifestyle. The largest group of people that
would benefit from TMR would be veteran amputees.
The wars in Iraq and Afghanistan have produced
1,286 amputees [8]. The amount of amputees from
the two main operations in Iraq can be seen in the
following image.
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Luke Schmidt
from the start of the clinical procedure to the end, the
user may return to activities they were doing before
the amputation. Even though there are some
negatives to this technology, the positives far
outweigh the negatives. The myoelectric arm is
critical in helping us pay back those men and women
who have put their lives on the line for our freedom,
and as a result have lost a limb. A piece of
technology that can restore the ability of holding their
children to our servicemen and women is priceless,
and thus, the ultimate repayment for their service.
REFERENCES
[1] J. Dailami. (2002, May 4). “The Myoelectric Arm: It’s
Electrifying.”
Illumin.
[Online
article].
Available:
http://www.engr2.pitt.edu/freshman/academic/eng12/spring2012/P
resentingSources.pdf
[2] T. Kuiken, L. Miller, R. Lipschutz, B. Lock, K. Stubblefield, P.
Marasco, P. Zhau, Gregory Dumanian. (2007, February 3).
“Targeted reinnervation for enhanced prosthetic arm function in a
woman with a proximal amputation: a case study”. Arizona State
Engineering.
[Online].
Available:
http://www2.engr.arizona.edu/~bme517/Prosthetics%20Reinnervat
ion%20Paper.pdf
[3] S. Jeffrey. (2007, February 3). “Targeted Muscle Reinnervation
Improves Use of Prosthetic Arm,” Lancet. pp. 371-380.
[4] “TMR.” Advanced Arm Dynamics. [Online]. Available:
http://www.armdynamics.com/pages/tmr
[5] (2007). “Targeted Muscle Reinnervation: Control Your
Prosthetic Arm With Thought.” Rehabilitation Institute of
Chicago.
[Online].
Available:
http://www.ric.org/conditions/pocc/services/bionic.aspx
[6] K. Stubblefield, L. Miller, R. Lipschutz, and Todd Kuiken.
(2009). “Occupational therapy protocol for amputees with targeted
muscle reinnervation.” Journal of Rehabilitation Research &
Development.
[Online].
Available:
http://www.rehab.research.va.gov/jour/09/46/4/pdf/stubblefield.pdf
[7] H. Fischer (2010). “U.S. Military Casualty Statistics: Operation
New Dawn, Operation Iraqi Freedom, and Operation Enduring
Freedom” Congressional Research Service. [Online]. Available:
Available: http://www.fas.org/sgp/crs/natsec/RS22452.pdf
[8] L. Martinez. (2011, November 11). “U.S. Veterans: By the
Numbers.”
ABC
News.
[Online
article].
Available:
http://abcnews.go.com/Politics/us-veteransnumbers/story?id=14928136#1
[9] J. Johnson. (2011, September 21). “US Military Amputees
Increase in Afghan War.” Newser. [Online article]. Available:
http://www.newser.com/story/129128/us-military-amputeesincrease-in-afghan-war.html
FIGURE 6
A VETERAN RETURNING FROM THE WAR IN IRAQ RECEIVES A
NEW MYOELECTRIC ARM AFTER HIS AMPUTATION [1]
The black area in the image above can be made more
natural looking by adding a silicon or latex product
that looks like skin [1]. This is critical because
amputees tend to wear their less functional but more
natural looking prosthetics in public. The myoelectric
arm takes the best of both cosmetically appealing and
highly functional arms and combines them. This
allows the amputee to interact with others the way
they normally would have. The only drawback is that
the arm’s battery can lose its charge, and therefore
lose its function until it is recharged [1]. Clearly, the
pros far outweigh the cons. It is the ethical duty of
bioengineers to share novel technology with those in
need, especially with the men and women who have
sacrificed so much for the safety of this country.
TARGETED MUSCLE REINNERVATION : IN
CONCLUSION
Targeted Muscle Reinnervation is a procedure that
takes four unused nerves and moved them to four
unused muscle regions. TMR allows the user to
control a myoelectric arm with simply the thought of
flexing a muscle to move their new prosthetic arm.
The results of TMR are incredible improvements in
abilities and actions, a more natural look for
amputees, and a large step closer to the life they lived
before the amputation. After the roughly 18 months
ADDITIONAL REFERENCES
Ottobock Healthcare. “Targeted Muscle Reinnervation.”Otto Bock
Healthcare.
[Online].
Available:
http://www.ottobock.com/cps/rde/xbcr/ob_com_en/646D385-GB03-1006w.pdf
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Robert Decker
Luke Schmidt
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ACKNOWLEDGEMENTS
We would like to thank John Lavanga from the
University of Pittsburgh Writing Center for helping
us with tweaking our abstract so we can really get our
focus on this paper. It helped tremendously with the
bibliography and this version of the outline. Also, we
would like to thank our co-chair, Abby, for helping
us further detail and focus our topic.
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