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

TLDR

The study designs and tests a retinal prosthesis that replaces defective photoreceptors in RP and AMD patients, focusing on a microchip telemetry decoder and stimulus generator. The prosthesis comprises an extraocular unit with a camera, processing board, telemetry encoder, RF amplifier, and primary coil, and an intraocular unit with a secondary coil, rectifier, regulator, a CMOS telemetry decoder and stimulus generator, and a 100‑electrode array, all powered and data‑controlled via a telemetric inductive link. Fabricated in 1.2‑mm CMOS, the microchip successfully delivered biphasic current pulses to a 100‑electrode retinal array at video frame rates.

Abstract

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 implantable component receives power and a data signal via a telemetric inductive link between the two units. The extraocular unit includes a video camera and video processing board, a telemetry protocol encoder chip, and an RF amplifier 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 on the design, fabrication, and testing of a microchip which serves as the telemetry protocol decoder and stimulus signal generator. It is fabricated by MOSIS with 1.2-mm CMOS technology and was demonstrated to provide the desired biphasic current stimulus pulses for an array of 100 retinal electrodes at video frame rates.