Resonant Inductive Wireless Power Transfer Link for Rechargeable Pacemakers

In this contribution, a wireless link for power transfer to a pulse generator implanted in the chest is presented. After a brief introduction to Wireless Power Transfer (WPT), the key aspects of the development of a WPT link intended for medical implants are discussed. Later on, the results achieved for a link based on resonant inductive coupling are illustrated. The presented link consists of two planar resonators and operates in the MedRadio (Medical Device Radiocommunications Service) band centered at 403 MHz. The wireless power link occurs between an external resonator operating in direct contact with the skin and a receiving resonator integrated in the silicone header of a pulse generator implanted in the chest. Numerical and experimental results are presented and discussed. From measurements performed by using minced pork to simulate the presence of human tissues, an efficiency of about 51 % is demonstrated. The feasibility of using the proposed link for recharging the medical implant in compliance with safety regulations and with a reasonable charging time is also discussed. It is demonstrated that the achieved performance allows recharging a Li-ion battery with a maximum capacity of 266 mAh in 4 hours.