Simulation of the Electrode-Tissue Interface with Biphasic Pulse Train for Epi-retinal Prosthesis

S. Biswas[1], S. Das[2], M. Mahadevappa[2]
[1]Advanced Technology Development Center, Indian Institute of Technology, Kharagpur
[2]School of Medical Science and Technology, Indian Institute of Technology, Kharagpur
Published in 2013

Retinitis Pigmentosa (RP) and Age-related Macular Degeneration (AMD) are diseases causing blindness in a large number of people. In this type of degenerative disease, mostly the photoreceptors are damaged. Thus attempts have been made to electrically stimulate the surviving inner retinal neurons and retinal ganglion cells (RGC) in order to restore vision. In this paper, the electrode-tissue interface is modeled with the AC/DC Module of COMSOL Multiphysics® to study the effect of electrode size and distance between the electrode and retina by applying biphasic pulse trains similar to in-vitro and in-vivo trials. Solved for time and frequency domain, electric potential in the RGC layer was found to vary both as a function of electrode diameter and distance of the electrode.