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
Need to create a prosthesis
that would be 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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Made a cast of
Matthew’s arm, which
was used to make a
mold of Matthew’s arm
in order to test
prosthetic designs.
Originally did a cast
with flexible fiberglass
material
Had to redo the cast
with plaster
Work Completed: Measurements
Took measurements to ensure
correctly proportioned device
 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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Work Completed: Test Sockets
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Test socket made from mold
Met with Matthew and his mother to fit first test
socket
Original plastic is Thermolyn Soft,
manufactured by Otto Bock
 more flexible and easier to form onto very
small mold shapes
Now using 3/16” thickness Vivak plastic, a high
temperature PETG plastic
 to use a plastic which had zero creep
Work Completed
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Met with Aaron,
Matthew, and his mother
and father 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.
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.
Work Completed
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Gave Matthew and his
parents software and
electrodes to use at
home in order to
practice contracting
muscles to control
MyoBock hand.
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
Future Work: Meeting our goals
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Matt must learn how to use the
electronic hand well before adding
additional components
Accomplishing reaching tasks will be
put on hold until hand is mastered,
then controlling elbow can be
mastered.
Better product in the long run, but it
will require work on Matthew and his
family’s part