MyKnee: Mechatronic Design of a Novel Powered Variable Stiffness Prosthetic Knee

Abstract

Powered prosthetic legs have the potential of significantly enhancing the mobility, independence, and overall quality of life of individuals with lower-limb amputation. Unfortunately, powered prosthesis are followed by the issue of their weight and limited battery life when compared to passive or semi-active prosthesis, which, conversely, lack of complex movement capabilities. In this paper, we present an innovative design and the development of a powered prosthetic knee joint, which is actuated by means of a compact variable stiffness actuator. This innovative and promising technology can provide adaptability to different activities of daily living, while also ensuring energy efficiency and maintaining a lightweight design. The key feature of this novel powered knee joint lies in the use of a mechanism that can vary the stiffness of the joint through newly designed non-linear elastic elements. By applying advanced finite element analysis in the design process, a robust device has been realized that could readily comply with the ISO 10328.2016 standard for structural integrity. This made the knee joint suitable for future clinical trials with people with above-knee amputation.