Designing a Prosthesis for a Tethered Biomechatronic Actuation System

Currently, biomechatronic instruments provide huge potential in supporting researchers about human motions and the design of tethered prosthesis for recovery training use. However, the difficulty in quantifying human motion casts limitations to the capability of these products to emulate both human motion patterns and biological energy transmission. The general idea of research biomechatronic actuation systems is to analyze the numerical relations between muscular motions and actuation power input. Our project is to design a light-weighted bracket structure mounted on a wearable prosthesis for a tethered biomechatronic actuation system. The bracket is comprised of a U-shape aluminum structure and pulley, aiming at transmitting mechanical power from control panels, maintaining constant moment arm and providing space for mounting sensors of control use. After conceptual design, we decided to manufacture an add-on bracket for the prosthesis. We performed several iterations to fulfill our requirements. Particularly, the maximum torque load is about 178 N•m, the maximum compression on stoppers is about 2200 N, and the range of flexion is from -10° to +20°. During the winter quarter, we computed the ranges of important geometric values for the bracket and analyzed required mechanical properties of materials. The simulation results suggest that the structure of bracket is within strength requirements with basis material Aluminum 6061-T6. In spring quarter we designed several benchtop test and further improve our design based on results. In last test, our structure successfully withstand 420 lbs loading without obvious distortion or damage.

Final paper and final poster available upon request.