Design of a semi-active knee prosthesis

Current state-of-the-art prostheses for transfemoral amputees operate exclusively through controlled damping or through fully powered gait imitation. The passive devices cannot restore a natural gait, and the active devices are large and inefficient. This paper summarizes the design of a new semi-active prosthetic knee that combines the proven safety and power efficiency of a passively damped hydraulic device with the improved gait and advanced mobility of a fully active device.