Principle design of an energy efficient transfemoral prosthesis

In the pursuit of realizing an energy efficient transfemoral prosthetic, in this paper we present a preliminary study on a principle design. In particular, the design is based on the idea that the efficiency of the system can be realized by energetically coupling the knee and the ankle joints. In order to allow the energy transfer during the normal walking, we propose to introduce continuous controllable springs, which basically act as passive actuators