Daniel Palanker Department of Ophthalmology and Hansen Experimental Physics Laboratory Stanford University, CA
ABSTRACT -
Development of the electronic retinal prostheses aims at restoring sight in blind patients with retinal degeneration. Current retinal implants have just a few electrodes, whereas thousands of pixels would be required for functional restoration of sight.
I will 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 visual perception. 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 3-dimentional pillar and chamber arrays in RCS rats with a 6 week follow-up demonstrate achievement of intimate proximity between the stimulation cites and the inner nuclear layer.
BIOGRAPHY -
Daniel Palanker is an Assistant Professor in the Department of Ophthalmology and in the Hansen Experimental Physics Laboratory at Stanford University. In the Department of Ophthalmology he serves as a Director of Basic Research. Dr. Palanker received his PhD in Applied Physics in 1994 from the Hebrew University of Jerusalem, Israel. He is working at the interface of physics and medicine studying the interactions of electric field with biological cells and tissues in a broad range of frequencies: from electronics to optics. He develops applications of these interactions in imaging, diagnostic, therapeutic, and prosthetic ophthalmic technologies. Therapeutic applications include microsurgical techniques based on pulsed lasers and electric discharges. His research in the field of prosthetics is focused on development of a high-resolution optoelectronic retinal prosthesis system for restoring sight in patients with retinal degeneration. In diagnostics, he works on non-invasive optical technique for monitoring physiological stress in the retina based on analysis of polarized light scattering.