Development of a Myoelectric Hand Incorporating a Residual Thumb for Transmetacarpal Amputees

Abstract

Restoring the hand functionality of partial amputees requires a myoelectric prosthetic hand, which is a robotic hand controlled by myoelectric signals from the skin surface and has the potential to restore human hand functionality. Most myoelectric hands have been developed for forearm amputees, while those for partial-hand amputees are few in number despite the higher numbers of the latter. Partial-hand amputees have limited hand functionality and cannot grasp and manipulate various objects in a manner comparable to individuals with a healthy hand; thus, they require a myoelectric hand. In this study, design issues were identified, and three-dimensional computer-aided design was used to propose an integrated skeleton and housing with a supporting socket. A passive thumb mechanism with motion in the remaining part of the hand was developed where the motion control system is based on the amputee’s muscles. An amputation system is proposed comprising mixed metacarpal and center-part cuts. A prototype was constructed, and its gripping functionality was evaluated. The results demonstrated an enhanced gripping performance compared to the non-use of prosthetics, which attests to the viability and effectiveness of the system.