Wireless Power Supply for Implantable Biomedical Device Based on Primary Input Voltage Regulation

This paper presents a wireless power supply system for implantable biomedical devices. Magnitude of the input voltage supplied to the primary power converter is dynamically regulated according to the power demand of the device. The major advantage of such a system is that its average power loss is minimized. Unlike methods implemented at implantable secondary (pick-up) side, the magnitude regulation is undertaken at the external primary side. Thus the heating effect and physical size of the implantable secondary can be reduced. The system utilizes parallel tuning circuit to boost the voltage induced in the secondary pick-up, and does not require a tight coupling between the primary and secondary coils. As a result, the system has great tolerance to the variation in the air gap distance between the coils. The characteristics of the magnitude regulated power flow have been thoroughly analyzed, and both simulations and laboratory experiments have verified the proposed system.