Modeling of Retinal Electrical Stimulation Using a Micro Electrode Array Coupled with the Gouy-Chapman Electrical Double Layer Model to Investigate Stimulation Efficiency

F. Dupont, R. Scapolan, C. Condemine, J.F. Bêche, M. Belleville, and P. Pham
CEA, LETI, Minatec, Grenoble, France
Published in 2010

The electrical stimulation for retinal implant has known significant improvements in the last decades with many implantations and experimentations. The ability to create better controlled and adapted signals to increase the efficiency in stimulation is a major objective. The aim of this study is to develop a numerical platform based on COMSOL Multiphysics to simulate different waveforms. The mathematical model is based on the AC Electrokinetic Complex Equation coupled to the Helmholtz model of the Electrical Double Layer (EDL) which is formed at the interface between the electrode surface and the extracellular medium. The efficiency of stimulation is tested using a Hodgkin-Huxley model for the ganglion activity. The nine-element Titanium Micro Electrode Array (MEA) was manufactured at CEA. Computation results are compared to impedance measurements.