A Novel Design of Transcutaneous Power and Data Bidirectional Transfer System for Biomedical Implants

Electrical stimulation of the optic nerve has been identified as a form of visual prosthesis to restore lost vision in blind patients affected by retinitis pigmentosa and age-related macular degeneration, through many studies and experiments. Magnetic transcutaneous coupling is frequently used for power transfer to implanted electronic devices. In such a prosthetic device, how to improve the power transfer efficiency and how we can get a precise DC voltage output are the two of the most challengeable elements in the whole system design. This paper presents the use of a transmitter coil driver based on the class-E amplifier. The closed-loop class-E circuit shows a great promise, especially for the circuits with unusually low coefficients of coupling. The transfer system is designed to a high-Q system and it can compensate for the transmitter and receiver variations via a smart feedback system. The system is optimized to minimize the power losses. This paper also describes the design of a data transfer system. This part can deliver the processed digital information that is useful for the implanted stimulator from the external side to the internal side (implant).