Abstract
A TF (transfemoral) prosthesis with MR-SPCOM (MR (Magneto-Rheological) fluid brake-Stance Phase Controlled by Optional Motion) knee joint has been designed and developed, which mainly consists of a variable resistance knee joint with a developed MR fluid brake and a developed load cell detecting the wearer’s optional motions. The optional motions mean that the wearers slightly push their stump ends back and forward voluntarily. As the resistance torque of the knee joint can be voluntarily controlled by using a computer based on signals from sensors such as a load cell, an encoder detecting knee angle and other touch sensors, it was possible to smoothly ascend and descend stairs reciprocally and to voluntarily lock and yield the knee joint during sitting down on a chair. The results were accomplished by the improvements of the load cell, several other sensors and the control scheme. In this paper, the design concept, theoretical approaches and structure of the improved TF prosthesis with the MR-SPCOM knee joint are described, and the results of the gait and motion analyses are discussed.
