Retractor-Type Robotic Knee Prosthesis to Prevent Fall

Abstract

In recent years, while the number of elderly lower limb amputees has been increasing, the use rate of lower limb prosthesis among the elderly has been low due to the risk of falling. Knee joints in the transfemoral prosthesis play an important role in regaining the gait ability of amputees. Particularly, the electronically controlled knee joint enables full prevention, by a system that automatically adjusts the optimal knee flexion resistance force based on the estimation of the gait state. However, it is difficult for the user to predict how much load is applied to the knee joint, which is one of the references for adjusting the bending resistance. This reduces the intuitiveness of the control system given to the user. In this study, we developed a robotic knee prosthesis that prevents falling with a proposed gait model to control the locking mechanism of knee flexion. Finally, we conducted experiments with the developed knee joint comparing the passive-type knee joint. From these experiments, we confirmed that our robotic knee prosthesis prevented falling certainly. The effectiveness of fall prevention is shown after the experiment.