Intraocular vision aid (IOS): optical signal transmission and image generation

The technology of both the signal transmission and the miniature LED display for an Intraocular Vision Aid (IOS) are presented. IOS Os under development to provide artificial vision to people suffering from blindness due to blurred cornea. A high dynamic range CMOS camera outside the eye and a miniature display (32×32 GaAsP/GaP LED array) flip-chip-bonded to a silicon CMOS-driver circuit in an implantable intraocular lens are the main parts of the system. The system works as follows: The CMOS camera generates a digital black and white picture which is converted by a digital signal processing unit (DSP) into Manchester coded data signals. The data set is then optically transmitted at a rate of 1 Mbit/s to the data and clock recovery circuit placed in the intraocular lens. Due to strong optical absorption in the cornea power is transferred using an RF link. A DSP in the eye provides suitable signals for the silicon driver circuit of the LED display. The image on the retina projected by the LED display stimulates the photoreceptors inside the retina, thus transmitting the signals via the ganglion cell layer and the optic nerve to the visual cortex of the brain