Comparison of Monophasic and Biphasic Electrical Stimulation by Using Temporal Analysis for Different Inter-electrode Spacings in the Hexagonal Arrays


ÇELİK M. E. , KARAGÖZ İ.

ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING, vol.43, no.6, pp.2889-2898, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 6
  • Publication Date: 2018
  • Doi Number: 10.1007/s13369-017-2918-z
  • Title of Journal : ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
  • Page Numbers: pp.2889-2898

Abstract

Recent multidisciplinary studies in the field of visual prosthesis rely on electrically stimulating retinal tissue by placing electrode array into different part of it, bypassing the nerve cells of the visual pathway which have lost their functionality due to various degenerative diseases. The visual prosthesis systems could be more efficient by mimicking physiologically natural electrical signals. In this study, the responses of the retina to biphasic and monophasic electrical stimulations were compared temporally using in-vitro rabbit retina. The retinal tissue was electrically stimulated with charge-balanced biphasic and monophasic pulses. When temporal diversity was comparatively analyzed, spike activity was observed to intensify in the first 20 ms after the moment of stimulation for biphasic stimulation. On the other hand, the spike activity was observed to form in a way that it can be classified into two categories, the primary one forming in the first 20 ms and the secondary delayed one forming between 80 and 100 ms for monophasic stimulation. Moreover, the effect of retina stimulation amplitude was also analyzed. The spike distribution was observed to cumulate mostly in the post-stimulation time interval of the first 20 ms as the stimulation amplitude for biphasic stimulation increased. In monophasic stimulation, secondary delayed spike activity was observed over 80 . The obtained experimental findings suggested that lower amplitude charge-balanced short biphasic waveforms could better elicit the precise and proper stimulation patterns necessary to mimic the neural activity of retinal circuitry that resembles the natural ones when it was compared with monophasic stimulation.