NEVIS: Visualization of factors influencing force recruitment in intraneural stimulation. II

For part I, see ibid. p.359-360 (1994). The newly developed visualization tool `NEVIS´ (Neuro-Visualization), presented in part I of this paper, is applied to intrafascicular electrical stimulation of the peroneal nerve of the rat, for control of the Extensor Digitorum Longus (EDL) muscle. The force recruitment behavior was studied in an extensive simulation study. The results show that diameter selectivity (reverse recruitment order) is only obtained when the stimulating electrode is at a large distance from the nerve fibers innervating the muscle, when the nerve is immersed in a well conducting extraneural medium. The resulting recruitment curves are however very steep, indicating that many fibers turn on and off synchronously, resulting in poor selectivity of the stimulation