Hey guys! We talked a little about the retina last week, so here's a bit on an interesting project discussed in my bioengineering class. The goal is to create a prosthesis to restore vision for visually impaired patients. Simply put, your visual system involves capturing light and focusing it onto the back surface of the eye called the retina. Light detecting cells in the retina processes this information and sends it to the visual cortex of the brain, which in turn interprets what we see.
The group designed a retinal implant that functions for the lost photoreceptors by electrically stimulating the remaining healty cells of the retina. These cells will create discrete points of light, leading to the perception of a shape.
This is a pair of glasses that captures an image with a camera, which is then converted into a pattern of electrical stimulations. There is a transmitting coil on the arm of the glasses that uses radiofrequency transmission to send information and power to the retinal implant. No need to have battery implants or wires going through body!
There is an array of stimulation electrodes in the implant that send current to appropriate areas of the retina corresponding to image.
Excerpt from site on progress of project... very cool stuff =]
"We have performed a total of six experiments on humans. These experiments were relatively brief (i.e. they lasted hours) and involved the surgical placement of an electrode array on to the surface of the retina. Very small electrical currents were delivered to the retina. Some of our patients who had been legally-blind for decades were able to see relatively small spots of light (i.e. like a "pea" as if viewed at arm's length) and occasionally were able to distinguish two spots of light from one another and "see" a line."
For more info! --> http://www.bostonretinalimplant.org