Low-Cost and Lightweight Trans-Radial Prosthesis with Three Opposed Fingers Considering Functionality and Design

Abstract

At present, there are body-powered hooks and myoelectric prosthetic hands that trans-radial amputees can use for work. Though the body-powered hook has good workability in detailed works, the design of the hook spoils its appearance and the harness impairs the feelings of wearing. The myoelectric prosthetic hand has a natural appearance similar to the human hand and intuitive operability with a myoelectric control system. However, it is high cost and heavyweight. Because of these problems, many amputees use cosmetic prostheses especially in Japan. In this paper, we report a low-cost and lightweight electric prosthesis with three opposed fingers considering functionality and design. A simple mechanism to control fingers by a linear actuator contributes to satisfactory workability, lightweight, and low cost. A control system using an inexpensive distance sensor allows intuitive operability as the myoelectric sensor at low cost. A socket is easily removable so that users can wear properly as the situation demands. It has a sophisticated appearance as a tool and can be produced by a 3D printer. The total weight of the hand and socket is 300[g]. Evaluation tests utilizing Southampton Hand Assessment Procedure (SHAP) demonstrated that developed prosthesis was effective to operate light objects for daily use.