Active & Intelligent Electromyography based Ankle Foot Prosthesis Design to Improve Walking Metabolic Cost for Trans-tibial Amputations

Abstract

The human ankle provides a significant amount of net positive work during the stance period of walking, especially at moderate to fast walking speeds. On the contrary, conventional ankle-foot prostheses are completely passive during stance, and consequently, cannot provide net positive work. Clinical studies indicate that trans-tibial amputees using conventional prostheses exhibit higher gait metabolic rates as compared to intact individuals. Researchers believe the main cause for the observed increase in metabolism is due to the inability to provide net positive work at terminal stance in walking. The objective of this project is build and run a prototype of an intelligent powered ankle foot prosthesis based on electromyography, capable of providing active mechanical power at terminal stance, can improve amputee metabolic walking economy compared to a passive or passive-elastic prosthesis. A powered prosthesis is designed and built that comprises a unidirectional spring, configured in parallel with a force-controllable actuator with series elasticity. The prosthesis is controlled to mimic human ankle walking behavior, in particular, the power generation characteristics observed in normal human walking