PANTOE 1: Biomechanical design of powered ankle-foot prosthesis with compliant joints and segmented foot

Abstract

This paper presents the design of a novel powered ankle-foot prosthesis with compliant ankle and segmented foot. The powered compliant ankle is proposed to replace the able-bodied ankle which can provide sufficient power to propel the body upward and forward during bipedal walking. In order to make the walking gaits of the amputees more stable and natural, we introduce segmented foot with toe joint to the prosthesis. The segmented foot decreases the torque of the ankle and makes the amputees effort-saving. Both the ankle and toe joints are driven by two series-elastic actuators (SEA), which not only provide enough torque, but also tolerance shocks. The sensory system of the prosthesis includes angle sensors, touch sensors and force sensors. The sensory system can detect and feed back the position and torque of the joints real-time. Preliminary experiments have been carried out to evaluate the safety and functionality of the proposed powered prosthesis. The experimental results show that the powered prosthesis with compliant ankle and segmented foot can reproduce the human walking gait and be easily used in walking rehabilitation.