Oxyopia Abstract

September 15, 2006
Friday, 4 PM
489 Minor Hall

Daniel Palanker, PhD
Assistant Professor, Dept. of Ophthalmology, School of Medicine and Hansen Experimental Physics Laboratory, Stanford University
Host: Yibin Tian

Title

Optoelectronic High Resolution Retinal Prosthesis

Abstract

Electronic retinal prostheses represent a potentially effective approach for restoring some degree of sight in blind patients with retinal degeneration. Functional restoration of sight would require hundreds to thousands of electrodes effectively stimulating remaining neurons in the retina.

We present a design of an optoelectronic retinal prosthetic system having 3mm diameter retinal implant with pixel sizes down to 25 micrometers, which allows for natural eye scanning for observing a large field of view, as well as spatial and temporal processing of the visual scene to optimize the patient experience. Information from a head mounted video camera is processed in a portable computer and delivered to the implanted photodiode array by projection from the LCD goggles using pulsed IR (810 nm) light. Each photodiode converts pulsed light (0.5 ms in duration) into electric current with efficiency of 0.3 A/W using common bi-phasic power line. Power is provided by the inductively-coupled RF link from the coil on the goggles into a miniature power supply implanted between the sclera and the conjuctiva, and connected to subretinal implant with a thin 2-wire trans-scleral cable.

Subretinal prosthesis uses 3-dimensional structures to induce retinal migration and thus ensure close proximity between stimulating electrodes and the target retinal neurons. Implantations of the pillar and chamber arrays in RCS rats with 2 and 6 week follow-up demonstrate achievement of intimate proximity between the stimulation cites and the inner nuclear layer.

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