Validation of a cortical electrode model for neuroprosthetics purposes

Abstract

A study of the electrical parameters of a microelectronic array designed for chronic current stimulation through cortical tissue was carried out. The microelectronic array was inmersed in ringer solution for measurements. Resistive and capacitive components, as well as total equivalent impedances were analyzed at different current levels using Electrochemical Impedance Spectroscopy (EIS) techniques. A SPICE equivalent model was introduced. Our results show that experimental registered data matches the proposed Warburg model for both low and high frequencies denoting how electrode impedances are affected with frequency variations. Moreover, effects produced by injecting different amount of charge were analysed. © Springer-Verlag Berlin Heidelberg 2003.