Project Update Limb-itless Chris Bruce, Anna Chen, Grant Hofmeister February 22, 2007

Components of the Prosthesis Socket- Forms the connection between the residual limb and the prosthesis. Liner- comfortable interface between skin and socket Shank (pylon)- Transfers weight from socket to the foot-ankle. Foot-ankle- Absorbs shock and impact and provides stability.

Research Meeting with Dr. Bruce Miller - Identified problems with his specific design - Discussed potential solutions National Orthopedic and Prosthetic Company - Explored the manufacturing facilities - Learned about the prosthesis making process and the different designs. - Learned about the materials that they use

Materials Sleeves/ Liner - Silicones - Urethane - Ethylene Vinyl Acetate Socket (Composite) - Carbon fibers - Fiberglass - Nyglass - Perlon

Problems with Dr. Miller’s Leg Load distribution- the load is focused at the single pin joint - can lead to chaffing Movement between liner and socket - Rotational and axial movement - fluid aggregation Volume of stump decreases throughout the day.

Potential Solutions Magnets- reduce socket liner motion More pins- spread out load distribution Air Bladder- user adjustable for volume change

Magnets Magnets can be used to attach the socket to the liner over the entire interface. Insert magnets into silicone liner Using electromagnet adhesion between socket and liner can be switched on or off. Load is evenly distributed. There would be no rotational or axial motion.

Pins Multiple pins could be used to attach the liner to the socket. This design would allow for distribution of the load over multiple points.

Air Bladder Air pockets can be put into the socket or the liner. Air could be pumped into air bladder to accommodate stump volume decreases and secure the stump more firmly to the socket.

Next Steps Go to prosthetist and discuss design issues and materials Talk to Professor Ross about feasibility of the magnet option. Choose most viable option. Obtain mold of Dr. Miller’s stump. Order the materials for our design.

GANTT Chart Phase Tasks 8- Feb 15- Feb 22- Feb 1- Mar 8- Mar 15- Mar 22- Mar 29- Mar 5- Apr 12- Apr 19- Apr 26- Apr 3- May 10- May 17- May Research meet/call Bruce visit NOPCO Visit Prosthetist Liner/Sock et designs investigate designs design model prototyping Testing load distribution comfort oxygen uptake Deliverables