Transcript Targeted Muscle Reinnervation

TARGETED MUSCLE
REINNERVATION
Nicholas Mulhern
10/9/12
BME 281
What is TMR
• Surgical Method for patients with upper extremity
amputations
• Reassigns nerves that once controlled the hand and arm
• Enables patients the ability to control motorized
prosthetics and regain sensory feedback
Historical Background
• First proposed in 1980 by Dr. Hoffer and Dr. Leob
– Nerve-Muscle Grafting
• Developed in 1995 by Dr. Todd Kuiken and DR. Gregory
Dumanian NWU
– Hyper-reinnevation on animals
• TMR for artificial limb control
– First Human work 2002
– Bilateral shoulder disarticulation amputee
Nerves
Use the Brachial Plexus Nerve bundle
Allow EMG Signals to be
generated naturally by
transferred residual nerves
Allows for sensory feedback
to the brain (natural
connection)
Brachial Plexus nerves drive
all joint degrees of freedom
Surgical Procedure
• Pectoral Muscles chosen for innervation
• Close to Shoulder
• Biologically unused due to amputation
• First Muscles are denervation
• Ligated Proximal end to prevent reinnervation
Musculocutaneous nerve  Clavicular head of the
Pectoralis major
Radial Nerve  Lower sternal end of the Pectoralis Major
Median Nerve  Upper Sternal of the Pectoralis Major
Surgical Procedure
• The pectoralis minor is translocated
• From under the major to the chest wall
• Connect the Ulnar nerve
• Removal of subcutaneous fat
• From over pectoral muscles to allow electrodes to be close to the
muscles
Post Surgical Rehabilitation
Post Surgery
• 3 months  First muscle Twitches
• Bending Phantom Elbow
• 5 Months Could contract all 4 pectoralis positions
separately
• Placed in training for all 27 motions
• Use 128 monopolar electrodes to detect signal impulse
Proportional Control
• Proportional EMG Control
• 4 EMG signal controls for 4 motions
• Elbow (Flexion/extension)
• Hand(open/ close)
• Allows 2 degrees of freedom
EMG recording and Proccesing
• Prosthetic control based on EMG from TMR muscles
• EMG: Electromyography
Purple: Direct control site
Green: Electrode Placement
Most electrodes placed over
muscles reinnervated by the
median and radial nerves
Future Innovation
• Enhance the Signals recorded
• Eliminate Crosstalk from other muscles
• Create a more distinct signal during multiple contractions
• Incorporate a 6 motor prosthesis
• TouchEMAS shoulder
• a humeral rotator
• Hand (Flex/ Exten)
• Improve TMR based NMI
• Using more neural information
• TMR uses nerves capable of controlling many muscles
Future Innovation
Thumb abduction
Thumb Adduction
Wrist Supination
Advantages
• Attempt at Advanced motorized neural prosthetic control
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using natural EMG signals
Doesn’t require any implants, Biocompatible
Targeted muscle acts as a natural amplifier
Multiple EMG signals produced allowing separate
functions controlled all at once
Intuitive to patients, based on nerves used
Sources
• http://en.wikipedia.org/wiki/Targeted_reinnervation
• http://informahealthcare.com/doi/abs/10.3109/030936404
09167756
• http://jama.jamanetwork.com/article.aspx?articleid=18337
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• Department of BME URI, BME 468 Slideshow 11