Design and analysis of active transfemoral prosthesis

Abstract

This paper describes an active above knee prosthesis designed to compensate the movements of transfemoral amputees. Analyze the gait of transfemoral amputee wearing intelligent prosthesis. Though the prosthesis can change damping at different speed and gait, the gait of healthy side and affected-side is out of step. The disorder gait increase stress of residual limb. Using Vicon MX system captures amputees' gait data and analyses the angle of healthy limb and prosthetic side. Intelligent prostheses still do not replace the power generation capabilities of the missing limb. Base on the principle of driving mechanism on robot lower limb and powered above knee prosthesis, Active transfemoral prosthesis is designed. The active above knee prosthesis uses linear motor as actuator. The structure of prosthesis knee joint is four bar linkage which can significantly keeping well with the being's Instant Center of Rotation. The gait signals of healthy subjects are used as input signal. The control strategy is Iterative Learning Control (ILC). The results indicate that the prosthesis prototype can basically simulate normal human gait.