Improving feedback in body powered protheses

This paper concentrates on the control of hand prostheses. It is stated that body powered voluntary closing devices possess the best control potential. Feedback paths are identified and the observation is made that feedback is strongly influenced by the design of the prosthesis. Finally, the operating force feedback path is investigated in more detail. Psychophy sical measurement methods point out (1) that operating forces should not be lower than 2.5N, and (2) that perforated self-adjusting shells should be used for good sensitivity in the information transmission through the interface. Introduction The Wilmer group is dedicated to applying principles of control engineering in mechanical design. Functional structures are conceived of from a system theory perspective, an approach that facilitates theoretical achievements such as feedback and feedforward to be implemented in a mechanical configuration. The design of hand prostheses is one of the main application fields. Over the years, the Wilmer group assessed a set of basic demands for rehabilitation aids, that may be summarised as the triple-C criteria: cosmetics, comfort and control [1]. In this paper, the control aspect of hand prostheses will be emphasised.