Electrical stimulation and myoelectric control. A theoretical and applied study relevant to prosthesis sensory feedback

Electrical nerve stimulation applied to an amputation stump to convey sensory feedback from a myoelectric hand prosthesis inevitably interferes with the prosthesis control system. The intention of this study is to investigate the extent of the interference to allow the implementation of a self-contained myoelectric prosthesis with electrical nerve stimulation feedback. The interference voltage sensed by two types of e.m.g. pick-up electrode units is studied as a function of the distance between the stimulating electrodes and the pick-up electrode units. Results obtained from experiments performed on human subjects andin vitro are supported by results based on electrical field theory. It is concluded that electrical nerve stimulation for prosthesis sensory feedback can be used close enough to myoelectric control systems to be in accordance with the principle of prothesis self-containment.