Design objectives and power limitations of human implantable wireless power transfer systems

Wireless power transfer (WPT) can provide a practical solution to powering implanted devices without requiring a power cable to puncture the skin. Whilst maximising link efficiency is normally the design aim of a WPT system in free space, there may be more suitable objectives if a receiver is implanted inside a patient, especially for devices with higher power consumption. This paper proposes alternative design principles to minimise the adverse effects of such a WPT system on the human body.