Three-dimensionally stacked analog retinal prosthesis chip

As blind patients with an intact optic nerve and damaged photoreceptor cells increase in number in recent years, there has been a growing interest in visual prostheses by electrically stimulating their retinas. Previous clinical studies indicated that blind patients perceive a controlled electrical current applied to a small area of the retina via electrodes as a spot of light. We propose a novel implantable device, so-called three-dimensionally (3D) stacked retinal prosthesis, which is composed of a photodetector, an image processor, electrical current generator circuits, and an electrode array on one chip. The spice simulation showed that our designed analog circuits for 3D stacked retinal prosthesis chip could output desirable electrical current with variable pulse width by controlling bias voltages.