Retinomorphic information processing for electrical epi-retinal vision implant stimulation

Over 8 million blind people world-wide, 450 000 blind people in the USA, and 35 000 blind people in Germany suffer from incurable retinal degeneration, particularly end-stage of macular degeneration and retinitis pigmentosa. Epi-retinal implants, capable of applying defined electrical stimulation impulses to the ganglion cell layer of blind patients´ retinas can produce visual perception for patients suffering from retinal degeneration. The necessary software to calculate respective electrical stimulation patterns is presented in this paper - a retinomorphic system that emulates and replaces the healthy retina. The retinomorphic software computes the electrical stimulation sequences for the micro-electrode array to produce visual perception corresponding to a live video stream. This paper also presents comprehensive mathematical functions to compute the spatiotemporal sequences of retinal ganglion cell receptive fields. These functions compute the firing rate of parvocellular and magnocellular ganglion cells in on- and off-versions as response to an applied video sequence.