A Form-fitting Photovoltaic Artificial Retina
Loss of photoreceptor cells has caught Scientist’s attention for a while. Scientists and engineers have attempted to produce retina artificial retina. A problem is how to get the power and data into a retinal chip, which is implanted to the back of a person’s eye. A team from Stanford University has worked on engineering a device. The device includes a video camera that captures images, a pocket PC that processes the video feed, and a bright near-infrared LCD display built into video goggles. The 900-nanometer-wavelength image can produce electricity in the chip. Some patients might still have a few functional photoreceptors that could be stimulated by visible light. The array is a series of pixels, each formed from a three photovoltaic cells of three different sizes. The purpose of the multiple sub-pixels, say the Stanford researchers, is to increase the amount of current sent to the functional photoreceptors. Recently, the Stanford researchers are trying to improve the system but allowing it to fit the curvature of the eye. They used flexures that allow the array to curve along with the natural shape of the retina. Despite how advanced this is the vision it provides is limited. Based on its size, it would give a visual acuity of about 20/200. In the best-case scenario, it would have a visual acuity of 20/100. That would allow face recognition and for reading large fonts.
W. Jones, “A Form-fitting Photovoltaic Artificial Retina,” IEEE Spectrum, 12/22/2009. 2/18/2010 <
http://spectrum.ieee.org/biomedical/bionics/a-formfitting-photovoltaic-artificial-retina>.
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