Wireless power transmission characteristics for implantable devices inside a human body

The resonance-based wireless power transfer technique is applied to biomedical devices implanted in the human body. The wireless power transfer system is designed for maximum power transfer into a small receiving coil of 10-mm radius at the 50-mm transfer distance. The power transfer efficiency from the transmitting resonant coil outside the phantom into the receiving resonant coil inside the phantom is calculated with varying the size of the free space placing the receiver in the phantom. The results represent that securing the free space surrounding the receiver in the phantom is closely related to the power transfer efficiency and absorbed electromagnetic energies in the human body.