Wireless IMU Sensing for Activity Control of Ankle Prosthesis

This proposal aims to develop a wireless IMU (WIMU) activity recognition system for SpringActive`s powered ankle prosthesis, Odyssey. Robust activity detection via WIMU will revolutionize the state-of-the-art in powered, lower limb prosthetics by integrating (i) bio-inspired intelligence with (ii) biomimetic mechanics into a highly-maneuverable, smart, ankle-foot prosthesis system. Odyssey is the ideal powered ankle platform for this development due to its large range of controllable dorsiflexion and plantarflexion, smooth and natural energy store and release strategy, and its continuous low level control structure which already seamlessly modulates its output based on user gait speed. Merging the low-level controller with a high-level activity recognition system based on WIMUs will provide the maximum benefit to the amputee user by optimizing Odyssey`s capabilities in varied terrain, e.g. steep slopes, and stairs. This Phase 1 project will lead to the development of a small, low power, wearable wireless IMU system capable of sending accurate and precise physiological data from body limb segments to a laptop or PC as a proof of concept. A model based on IMU data from the thigh, shank, and foot will determine the user`s activity, laying the foundation for system refinements and human subject validations in phase 2.