| abstract |
A wireless power transfer system for an implantable medical device is disclosed. The system comprises a transmitter configured to transmit wireless power transmission at a first operating frequency, and a receiver configured to receive the transmitted wireless power transmission, and to be electrically connectable to an implantable medical device. The transmitter is further configured to receive from the receiver an indication of an efficiency of the wireless power transmission at the first operating frequency, and if the efficiency falls below a threshold, then transmit wireless power transmission at a second operating frequency different to the first operating frequency, wherein the transmitter and receiver are configured to operate in any of regions; near-field, mid-field and far-field. |