Medical implant having closed loop transcutaneous energy transfer (tet) power transfer regulation circuitry

Abstract From the Canadian patent

An implantable medical device, such as a bi-directional infuser device for hydraulically controlling an artificial sphincter (e.g. adjustable gastric band) benefits from being remotely powered by transcutaneous energy transfer (TET) obviating the need for batteries. In order for active components in the medical device to operate a sinusoidal power signal received by a secondary coil is rectified and filtered. An amount of power transferred is modulated. In one version a voltage comparison is made of a resulting power supply voltage as referenced to a threshold to control pulse width modulation (PWM) of the received sinusoidal power signal achieving voltage regulation. Versions incorporate …