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

• Published in: IEEE journal of solid-state circuits Vol. 35; no. 10; pp. 1487 - 1497
• Main Authors: Liu, W., Vichienchom, K., Clements, M., DeMarco, S.C., Hughes, C., McGucken, E., Humayun, M.S., De Juan, E., Weiland, J.D., Greenberg, R.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2000; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Arrays; Chips; CMOS technology; Coiling; Coils; Decoders; Decoding; Devices; Electrodes; Eyes & eyesight; Macular degeneration; Photoreceptors; Prosthetics; Protocols; Retina; Signal generators; Telemetry
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/4.871327

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.