Selectivity of intraneural prosthetic interfaces for muscular control.

Intraneural stimulation with multi-electrodes in principle offers the best possibilities to reach selectivity at motor unit level and to improve recruitment order. The selectivity of stimulation in the peroneal nerve of the rat is explored in the paper by calculations and measurements, using a linear 12-electrode array and a newly devised selectivity test method. With analytical models for potential field distributions, areas of excitation can be calculated for arbitrary electrode configurations. It is demonstrated, using tripolar electrode combinations, how selectivity can be further enhanced and recruitment order improved.