Operator performance in myoelectric control of a multifunction prosthesis stimulator

In this paper, a microcomputer-based system is described which facilitates the evaluation of different myoelectric control strategies. The system is based on an IBM-PC/AT microcomputer which generates and develops tracking targets, processes and displays the operator's response, and computes tracking performance. The dynamics of the prosthetic elbow, hand, and forearm are simulated in software which drives a stick figure in response to the operator's input. Performance is measured in terms of integral absolute error in target-response match. Control strategies to simulate different systems are easily modified through software and are evaluated under identical conditions. As a test of this evaluation system and to obtain some comparative data on control strategies, four strategies which are either in use or proposed for use are evaluated. The test procedure is divided into a control training session and a control evaluation session. Data collected from groups of three normally-limbed subjects per strategy over a period of five control evaluation sessions are presented. The results of this evaluation are discussed and improvements in the evaluation system suggested.