An implantable power and data receiver and neuro-stimulus chip for a retinal prosthesis system

In certain diseases of the retina, the photoreceptor cells do not respond to light and thus cause blindness. We describe an electronic retinal prosthesis system that can provide some vision to patients by direct electrical stimulation of the retinal neurons. Power and image data are transferred to the implanted stimulator through a wireless inductive link. The system consists of an external video camera with image processing and encoding hardware and a power and data transmitter. Implanted in the eye are power and data receivers, stimulus circuits, and electrode array. The most recent prototype implant device, implemented in 1.2 micron CMOS, implements demodulation and decoding of the data stream and produces biphasic current stimulus pulses for an array of 100 retinal electrodes at video frame rates.