Refunctionalization of passive electromyographic electrodes to upper-limb prosthesis applications.

Abstract

The rehabilitation potential of myoelectric prosthesis for upper-limb amputee led to its wide investigation in the last two centuries. However, its everyday use still faces several challenges, such as high cost of available commercial models and unsatisfactory functionality. Thus, the present work proposes the development of an upper-limb prosthesis, focusing on the myoelectric signal measurement system. The electromyography system was integrated to an adjustable armband with three measurement channels made with traditional disposable Ag/AgCl passive electrodes readapted as active dry electrodes. For purposes of performance evaluation and database creation, myoelectric signals were collected from 12 healthy volunteers performing daily activities using a bottle. It was verified the high influence at measurements of volunteer physical characteristics, especially those relating to physical fitness, amount of forearm skin or adipose tissue, and sweating. Furthermore, the electrodes also showed high sensitivity to positioning and movement artifacts at the electrode-skin interface. A database of myoelectric signals was created for future pattern characterization. The electromyographic armband performance was demonstrated by driving a claw-type prosthesis using direct control.