Challenges in System and Circuit Design for High Density Retinal Prosthesis

A 32 times 32 retinal prosthesis is under development towards the goal of restoring vision in blind patients affected by retinitis pigmentosa and age-related macular degeneration. The system consists of three major functional components namely, microstimulator, wireless data telemetry, and wireless power telemetry. The system design and the circuit design of these blocks are governed by both biomedical and IC design constraints. This paper will provide a status update of the work and discuss the remaining challenges to be overcome to realize a fully integrated and miniaturized retinal prosthesis unit. Some of the challenges are integrating passive devices such as coils, diodes and capacitors, need for high voltage devices for stimulation, biocompatible and hermetic interface of the electronics