Selective activation of muscles using peripheral nerve electrodes

The feasibility of two methods for selectively activating muscles with peripheral nerve electrodes has been investigated. One method for achieving selectivity is to place a cuff electrode around the nerves to each group of synergistic muscles to be stimulated. A second method is to stimulate through pairs of electrodes selected from a multielectrode array placed around a common nerve trunk. Both methods have been tesed in experiments conducted on four dogs. It was shown that the first method, cuff electrodes placed on individual motor branches, is an effective technique for selective activation, Thresholds of motor bibres lying outside of, but adjacent to, cuff electrodes are much greater than the stimulus amplitudes required to maximally stimulate motor fibres contained within the cuff electrode. Good results were obtained with a multielectrode array in two animals, but results, were poor in a third dog. Electrode position and contact with the nerve were found to be important factors in achieving good selectivity.