Simulation of a Low Cost Powered Ankle-Foot Prosthesis during Stair Ascent and Descent Gaits

Human ankle is a synovial hinge joint where the tibia and fibula bones of leg meet the talus bone of the foot. The joint allows the dorsiflexion and plantar flexion movement of the foot during various stances of walking, running, climbing etc. Transtibial prosthesis helps to regain the function of lost foot. The advancement in transtibial prosthesis using myoelectric driven powered ankle foot prosthesis helped to achieve the most natural gaits in walking, climbing, and running etc. through nerve signals from the brain by nerve rewiring surgery which is very costly in INDIA. Most transtibial amputee cannot afford such advance technology in prosthesis to fulfill the loss caused, therefore, these amputee use conventional prosthetic leg that has no motion in ankle joints. In this paper, a design of an ankle foot device is presented to assist transtibial amputees during stair ascent and descent gaits. The device permits the dorsiflexion and plantarflexion movement of the prosthetic ankle during stair ambulation mimicking the gait pattern of normal human ankle. The dorsiflexion and plantarflexion movement is controlled by an actuator using PID. A 3D model, control scheme, and analysis of prosthetic device are presented in this paper. The objective of this paper is to present an easily affordable prosthetic device that is capable of assisting transtibial amputee during stair ambulation.