A retinal neuroprosthesis design based on simultaneous current injection

We present an epiretinal neuroprosthesis design based on a hexagonally-latticed 98 electrode array and the capacity to multiplex up to 14 simultaneous current sources. The digital and analogue electronics required to perform this function and how this would be incorporated into an application specific integrated circuit (ASIC) are described. Simulation data and data from saline bath testing of a platinum/silicone electrode array (and associated driving electronics) are presented. Simulations were performed using a 2D computational model solved using a custom collocation method. The guarding affect of the hexagonal array is investigated and shown in simple simulations to be an approach worthy of further investigation.