A neuro-stimulus chip with telemetry unit for retinal prosthetic device

In this retinal prosthesis project, a rehabilitative device is designed to replace the functionality of defective photoreceptors in patients suffering from retinitis pigmentosa (RP) and age-related macular degeneration (AMD), The device consists of an extraocular and an intraocular unit. The implant able component receives power and a data signal via a telemetric inductive link between the two units. The extraocular unit includes a video camera an d video processing board, a telemetry protocol encoder chip, and an RF ampl ifier and primary coil. The intraocular unit consists of a secondary coil, a rectifier and regulator, a retinal chip with a telemetry protocol decoder , a stimulus signal generator, and an electrode array, This paper focuses o n the design, fabrication, and testing of a microchip which serves as the t elemetry protocol decoder and stimulus signal generator. It is fabricated b y MOSIS with 1.2-mm CMOS technology and was demonstrated to provide the des ired biphasic current stimulus pulses for an array of 100 retinal electrode s at video frame fates.