The response of the myelinated nerve fiber to short duration biphasic stimulating currents

The response of a single Node of Ranvier to short duration biphasic stimulating currents was studied. Such stimulus patterns are known to be less likely to induce tissue damage than are longer monophasic stimuli. The presence of the anodic phase of a pulse pair was found to abolish excitation in cases where the cathodic phase alone was near threshold. In addition, peak twitch force from the tibialis anterior muscle of cat was found to be reduced by the use of biphasic motor nerve stimulation in place of monophasic stimulation. The abolition phenomenon could be eliminated by the introduction of a delay of 100 μs between the phases of a biphasic stimulus waveform. This research was supported by the National Institutes of Health, Grant No. NINCDS NO1-NS-2-2314 (Neural Prosthesis Program) and GM 01090-15 Training Grant.