An adaptive wireless powering and data telemetry system for optic nerve stimulation

To treat retinal degenerative diseases, a transcorneal electrical stimulation-based system is proposed which consists of an in vivo eye implant and an in vitro control device. The eye implant is wirelessly powered and controlled by the in vitro device to generate the required bi-phase current pattern for the transcorneal stimulation with an amplitude range of 5μA~320μA, a frequency range of 10Hz~160Hz and a duty ratio range of 2.5%~20%. Only one pair of coils is used for both the power link and the bi-directional data link. Except the secondary coil, the eye implant is fully integrated on chip and fabricated using UMC 0.13μm CMOS process with a size of 1.5mm by 1.5mm. The secondary coil is tiny and fabricated on a PCB with an outer diameter of only 4.4mm. After packaging with biocompatible silicone, the whole implant has a dimension of 6mm diameter with a thickness of less than 1mm. The whole device can be put on the sclera and beneath the eye´s conjunctiva. Measurement results verify the system´s functionality and demonstrate the performance.