Robotic transtibial prosthesis with biomechanical energy regeneration

Purpose – The purpose of this paper is to describe a project which seeks to develop a new generation of powered prostheses based on lightweight, uniquely tuned, energy‐storing elastic elements in series with optimal actuator systems that will significantly reduce the peak power requirement of the motor and the total system energy requirement while providing the amputee 100 percent of required “push‐off” power and ankle sagittal plane range‐of‐motion comparable to able‐bodied gait. Design/methodology/approach – This paper presents the design, power, and energy‐efficiency analyses, and the results of a five‐month trial with one trans‐tibial amputee subject as part of the first phase of the Spring Ankle with Regenerative Kinetics project. Findings – The data show that by leveraging uniquely tuned springs and transmission mechanisms, motor power is easily amplified more than four fold and the electric energy requirement is cut in half compared with traditional approaches. Originality/value – This paper describes an energy efficient, powered transtibial prosthesis currently unavailable commercially. Motor power and energy requirements are reduced with use of a unique design that employs regenerative kinetics.