Prosthetic Arm Force Reducer Team 1 – Halliday's ... - Ohio University

Tim Lang – 2 nd Interview (2:00 PM – 4:00 PM) February 27 th 2008
• Did not seem to think additional weight in forearm would be an issue. Agreed to place
small (1-2 lb) weight in forearm for a couple arms sometime soon as a trial.
• Had no concerns with the Otto Bock hook. Really liked the vector system and had an
overall good impression of the hook.
• Increased range of motion due to mechanical advantage is going to be an issue. We need
to find a way to address this so that he doesn’t have to double his current movement
pattern. Also, current range of travel is caused by cable post coming into contact with the
wrist of his prosthetic, an issue we should be cautious of with our design.
• We took pictures of harness operation so that it could be examined by entire team. See
pictures posted by Jay.
• Threading of Otto Bock hook was a perfect match with his arm.
• Forearm connects to elbow which connects to the upper arm (three piece system). The
gearing of the arm placement is located in the elbow and the forearm appears to be
connected by screws in a fairly simple manner. See pictures.
• Problem with the cable pinching at the elbow if we run it directly into the forearm
through the current opening. We will need to address this issue in our design by finding
an alternative way for the cable to enter the forearm. Possibility of drilling slanted holes
for entry and exit or a slot into the arm at the elbow to avoid pinching the cable.
• Current cable is guided by leather loop as well as bolted connection points. Cable also
runs through a casing at points where there is a bend. Pictures will show this.
• Details of current cable should be able to be obtained by contacting Gene at Yankee
Bionic.
• Any bolt heads on the outside of the prosthetic must be smooth and round. Additionally,
the nuts on the interior of the arm are some sort of special flat type nut.
• Cable did not seem to be very flexible. Must be cautious in looping around pulley.
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