A CMOS microchip-based retinal prosthetic device for large numbers of stimulation in wide area

We have developed a retinal prosthetic device based on CMOS technology for STS, suprachoroidal transretinal stimulation method. Introducing CMOS technology makes it easy to realize large numbers of stimulus electrodes without increasing numbers of lead wires. We designed a micro CMOS chip integrating with stimulus current generation, decoding and controlling circuits on the chip area size of about 400 μm square. The microchip has two inputs and one stimulus output. In order to stimulate a wide area in the retina, we fabricated a fork-type stimulus device, where two sets of a stimulus array device based on the micro chip architecture are connected into one flexible substrate. Each stimulus device was implanted in different place of the rabbit´s retina, so that we can stimulate separated places of the retina. By increasing the number of the stimulus array device, we can stimulate a wide area of the retina without increasing the number of wiring by virtue of our microchip architecture.