Optical design for LED illumination in application of implantable retinal prostheses

Abstract

For those patients with degenerated photoreceptors such that fail to transfer visual information to other retinal cells in the retinal network, a 16x16 pixel self-powered implantable subretinal device has been developed trying to restore their vision. The device contains sensing pixels that collect environmental signal, and electrodes that serve neurostimulation. A photovoltaic cell was designed aside of the sensing pixels and electrodes for power supplying. IR LED was selected to radiate on the photovoltaic cells for energy input such that proper optical layout shall be designed. Several extraocular optical layouts for IR LED illumination are studied to evaluate the perfect efficiency of each layout. Suitable design is to be selected through the evaluation process. Some experiments are performed to study the feasibility of optical layout. Images of IR LED are taken by a CMOS sensor. Irradiance on the calibrated CMOS sensor is calculated for comparison.