A Control Method for Transfemoral Prosthetic Knees Based on Thigh Angular Motion^.

To regain the locomotive ability in daily living, many prosthetic knee joint units have been developed for transfemoral amputees. Until now, several prosthetic knees have been developed for stair ascent as commercial products. Such microprocessor controlled knees are multifunctional, and they are able to realize many activities of daily living for transfemoral amputees. However, those prosthetic knees are very expensive, so they have not been widely adopted. The purpose of the present study was to develop a control method for transfemoral prosthetic knees that deals with variation of gait parameters within subjects. We made improvement on the control algorithm that we previously developed for level walking and stair ascending. To evaluate the newly proposed algorithm and threshold values, the database of the level walking was used. Although gait detection for the stance phase of stair ascending could not be evaluated because of absence of a database for stair ascent, the precision and recall of the gate detection algorithm for the stance phase and swing phase of level walking were increased.