DISTINGUISHABILITY OF FUNCTIONALLY DISTINCT EVOKED NEUROELECTRIC SIGNALS ON THE SURFACE OF A NERVE

This paper describes initial experiments to determine the feasibility of recording functionally distinct neuroelectric signals from the surface of the rabbit's sciatic nerve. A cuff electrode assembly was constructed; it consisted of two planar arrays, each having four wires equally spaced around the circumference of the electrode. The electrode assembly was placed on the sciatic nerve proximal to the popliteal fossa. A hook electrode was placed on six branches of the sciatic nerve in turn, just proximal to each branch's insertion into a leg muscle. Stimulation of the nerve branches was used to evoke signals in the sciatic nerve. Analysis of the signal amplitudes recorded from the sciatic nerve after different nerve branch stimulation showed significant differences. The signals evoked by stimulation of the peroneal nerve were almost always distinguishable from the signals evoked by stimulation of the extensor nerves. Signals evoked by stimulation of the various extensor branches showed distinguishability at reduced levels of significance. After functional distinguishability of nerve signals was demonstrated, the electrical centers of activity of the stimulated fibers were mapped for cross sections of the sciatic nerve. The resulting loci correlate reasonably well with anatomical data describing the location of the nerve fibers. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.