Transcript Upper Limb Prosthetic Adaptation/Redesign

Upper Limb Prosthetic
Adaptation/Redesign
Group 6
Cassie Edwards, Meg Stevenson,
Amy Thomas, Meagan Williams
Advisor: Dr. Mark Richter
Aaron Fitzsimmons
Project Objectives
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Design or modify an
existing design of an
upper limb prosthetic
for a boy with upper
limb deformities
Create an upper limb
prosthesis
Existing Device
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Drawbacks: Taking
prosthesis on and off takes
considerable amount of time
and effort
Prosthesis is a very old
design that does not work
Redesign existing prosthesis
to make it more functional for
an active 8-year-old boy
Goals for New Device
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Short-term Goals
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Dress independently
Go to the bathroom on his own
Long-term Goals
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Be able to live independently
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i.e. – drive a car, cook for himself, use
standard household items, etc.
Original Ideas for Device
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Humeral cuff with Velcro closure
Stump sock interface over humerus
External elbow hinges
Myobock hand with myoelectric
interface
Figure 9 suspension
system
Work Completed
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Met with Aaron to discuss the next
step. He showed us how to make a cast
so we can make one of Matthew’s arm.
Made a cast of Matthew’s arm, which will
be used to make a mold of Matthew’s arm
in order to test prosthetic designs.
Test socket made
Met with Matthew and his mother to fit
test socket and discuss how they felt
about it.
Work Completed
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Met with Aaron,
Matthew, and his mother
and father to assess how
well the test socket fit
and to test for
myoelectric activity in
Matthew’s arm.
Matthew was found to
have myoelectric activity
and was able to open
and close MyoBock
hand.
Work Completed
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Met with Aaron, Matthew,
and his family to fit second
test socket, which was too
big, so a third one is being
made.
Gave Matthew and his
parents software and
electrodes to use at home
in order to practice
contracting muscles to
control MyoBock hand.
MyoBoy Software
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MyoBoy measures
patient muscle
potentials with the
same electrodes
used in the
definitive prosthesis
Matthew was found
to have independent
control of his
muscles
MyoBoy Software
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MyoBoy's fun
"racecar"
training module
helps to train
the patient for
their device
before they are
fitted.
Casting
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Originally did a
cast with flexible
fiberglass
material
Had to redo the
cast with plaster
Matt’s Measurements
From the AC joint to the lateral
epicondyl of the humerus: 21 cm
 From the lateral epicondyl to the
tip of the thumb: 19.5 cm (on
left arm)
 From base of metacarpal to the
tip of the thumb: 5.5 cm (left
hand) & 5 cm (right hand)
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Test Sockets
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Original plastic is Thermolyn Soft,
manufactured by Otto Bock
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more flexible and easier to form onto very
small mold shapes
Now using 3/16” thickness Vivak
plastic, a high temperature PETG plastic
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to use a plastic which had zero creep
Current Work
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4th socket device with electrodes
Sleeve to keep socket in place and
prevent air from escaping socket
Vacuum seal
Concerns about socket
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Sleeve is tight
Pressure from
electrodes hurts
Restrict circulation?
Vacuum seal
himself?
Ability to get on and
off himself
Future Work: Myoelectric Hand
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Ottobock Electrohand 2000 4.8 V
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DMC (Dynamic Mode Control)- speed of
opening, closing and grip force
determined by the level of muscle signal
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Grip Force=55 N
Wt=130 g (4.586 oz)
More closely mimics natural hand
Future Work: Elbow Component
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Ottobock 12K19 Body Powered
Passive Elbow Lock
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10 locking positions in 8 degree
increments
Can push a button to lock elbow
or can connect button to a figure
9 harness
Future Work: On Our Way to a
Finished Device
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Assess how the socket is fitting and
Matthew’s ability to control the
electrodes
Obtain parts to complete device
Put device together, let Matthew use
it and test it out for a period of time
and then reassess
Future Work: After the Finished
Device
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May need to adjust gain
Myobock ErgoArm Electronic Plus