Effect of Leakage Currents on the Formation of Electrical Pulse for the Vestibular Nerve Stimulation

Abstract

A theoretical and experimental study was performed of a frequency dependence of the amplitude-phase characteristics of the vestibular nerve stimulation signal and its changes during passage from the stimulating electrodes to the end of the vestibular nerve. To assess the influence of leakage currents on the change in the stimulating current pulse, a physico-mathematical model of the vestibular organ and electrical processes occurring in its tissues was developed on the basis of experimental data on electrophysical and anatomical characteristics of the vestibular labyrinth tissues by the example of a guinea pig. The calculations and measurements of the frequency dependence of the amplitude-phase characteristics of the stimulating signal at a recording electrode located in the Scarp’s ganglion are performed. It is established that the influence of leakage currents on the signal amplitude at the recording electrode is significant in the entire frequency range considered. Compensation of the influence of leakage currents will improve the stimulating signal quality and increase the transfer function of the vestibular implant.