Modeling and Characterization of Tissue/Electrode Interface in Capacitive µECoG Glassy Carbon Electrodes

Abstract

Understanding the chronic immune response of brain tissues to implanted neural electrodes is important from both a patient safety and long-term functionality standpoint. One emerging area of interest is examining the effects of the chronic immune response on the long-term functionality of cortical surface stimulating micro-electrodes. In this study, we use a simulation model to examine the parameters that influence the long-term success of cortical surface stimulating electrodes. Two computational models were developed and solved using finite element analysis; the first investigated the externally-induced electric field distribution in the brain tissues during stimulation and the effect of scar tissue formation on the stimulation thresholds. The second evaluated the potential changes in the pH around the electrode during stimulation. The models were based on in vivo experiments that have previously been conducted using chronically implanted glassy carbon based µECoG arrays.

Ultra-Capacitive Carbon Neural Probe Allows Simultaneous Long-Term Electrical Stimulations and High-Resolution Neurotransmitter Detection

“…This is expected due to the buffering action of the PBS solution. Moreover, our findings are consistent with pH levels predicted by a transient FEA model in our previous work where pH near the microelectrode surface returned back to the initial conditions after each charge-balanced cycle 23 .…”