CMOS Imager Technologies for Biomedical Applications

Presented is the design and characteristics of the first CMOS imager chip that has been implanted into a patient's eye with demonstration of partially-restored vision. Also presented and discussed are the design and characteristics of the first miniature APS imager chip based on thin-film-on-CMOS (TFC) photodiode technology targeted at low-cost and disposable diagnostic products. Both sensor designs exploit the high-dynamic range CMOS (HDRC*) pixel circuit providing a continuous lin-to-log transformation of the photo current into a voltage sense signal. This allows for implementing a retinal implant with characteristics similar to that of the human eye and to operate a miniature TFC imager for video inspection under strongly varying light conditions.