Resonant coupling energy transmission technology and its applications to implanted medical devices

Inductive charging uses the electromagnetic field to transfer energy between two objects. A charging station sends energy through inductive coupling to an electrical device, which stores the energy in the batteries. Because there is a certain gap between the two coils, inductive charging is one kind of certain-distance wireless energy transfers. A new technology called witricity for wirelessly energy transmission over a fair distance as reported by Massachusetts Institute of Technology (MIT) in July of 2007 provides a new possibility to overcome the above difficulties. The method is based on the well known principles of resonant coupling, which stipulates that resonant objects of the same resonant frequency tend to couple, while interacting weakly with other off-resonant environmental objects.;This project intends to develop a wireless energy transmission system based on witricity technology for powering and recharging certain implanted medical devices. A resonant coupling energy transmission system which is specially designed for implanted medical devices is thus proposed and implanted medical systems with different geometry structures including circular coil, ring-shaped coil, and rectangular coil have been designed specially for implanted medical devices.;Special coils with the same resonant frequency of the transmitter and the receiver have been fixed that the energy transmission efficiency can be greatly increased and the size of the receiver is substantially reduced. We used the models to capture the entire behavior of the system from transmitter to receiver including the power source circuit and charging circuit. Some experimental prototypes have been constructed to test the performance of the witricity energy transfer system. Three novel chargers based on witricity technology have been fabricated for cell phone charging, rats' experiment playground and DBS application.