Original URL: http://www.theregister.co.uk/2012/05/18/prosthetic_rat_retina/

Stanford boffins create light-powered artificial retina

Prosthetic works without batteries

By Richard Chirgwin

Posted in Science, 18th May 2012 01:27 GMT

A group of researchers led by Stanford University has created a prosthetic retina that works without an external power source. Instead, by combining a light sensor with photovoltaics, the implant is driven by light.

Since ambient light doesn’t provide enough power, the system pulses the implant with infrared light from goggles. It works like this: the goggles first capture the image, which is pre-processed by a handheld computer. The image is then sent back to the goggles, which project the image onto the retina with enough power to make the photovoltaics work.

Importantly, while generating enough power to run an artificial retina, its peak light intensity of 10 mW/mm2 is still well within the eye’s safety limit.

The system has so far only been tested on a rat's eye, with a single 70-micron pixel generating a neural response in the optic nerve, but as the abstract notes, that’s sufficient to demonstrate the viability of high-density prosthetics.

According to Technology Review, the Stanford team, led by Keith Mathieson of the Hansen Experimental Physics Laboratory, the artificial retina has so far achieved pixel densities of 178 pixels per square millimeter. ®