Improved Control for an Artificial Arm

INTRODUCTION Successful control of multi-degree of freedom upper limb prostheses generally uses some form of sequential instruction. This is because simultaneous control of multiple inputs requires a considerable concentration to be operated effectively. In contrast, the natural arm is controlled in a parallel manner with a high level of subconscious control. Such control uses feedback, the person is rarely conscious of the feedback information, and most of the control is automatic. Attempts to achieve similar control with a prosthesis would requires a wide bandwidth feedback channel to the controller. This is currently impractical if the controller of a multiple degree of freedom arm is the wearer, because only very low frequency feedback is achievable. The Southampton Arm control philosophy avoids this bottleneck by keeping the low level control within the prosthesis and leaves low bandwidth and strategic control to the operator [1].