Novel Control Strategies for Arm Prostheses : A Partnership between Man and Machine

Abstract

The human hand is an exquisite instrument. Most importantly, it is capable of performing a wide range of functions, and is able to switch seamlessly from one function to the next in response to the changing environment. Not surprisingly, the hand’ s loss through amputation is a major disability with drastic impact on quality of life. Prosthetic devices are designed to help alleviate some of the negative consequences of hand and arm amputation. Early prosthetic devices were purely mechanical, as exemplified by the traditional hook-and-cable systems. Later prostheses began to incorporate electrical and mechanical components to perform functions, and could be controlled by muscle signals in an amputee’ s residual limb （Fig. 1） . Termed myoelectric control, the use of muscle signals for control of robotic prostheses has gained increasing popularity since the 1960’ s. 1,2） Recent technological advances in sensor and actuator technology have further enabled the development of sophisticated myoelectric prostheses. These advances include myoelectric hands with multiple functions, or grip patterns, that amputees can select to perform various tasks. 3）