Electrodynamic Wireless Power and Data Transfer for Implanted Medical Devices

Implanted medical devices used in healthcare can be made smaller and less invasive by removing internal power sources. Self-powered and externally powered devices are at the forefront of research in this area. Whilst methods such as ultrasonic and inductive power and data transfer have shown great promise, there is potential for a safer option; Investigations into electrodynamic wireless power transfer methods have identified lower frequency means of powering medical devices. In this publication a piezoelectric beam transducer with permanent magnet tip is excited by a time varying magnetic field from an electromagnetic coil to achieve electrodynamic wireless power transfer of 1.1mW over a 15mm air gap. Experiments are performed to investigate the range and effect of misalignment between the transmitter and receiver. The beam is actuated to achieve data transfer back to the coil, which acts as an antenna. A lumped parameter model is produced which is validated with experimental results. Data transfer is shown to be achievable, and a digital communication protocol is suggested using bursts to transmit binarized sequences. With ever growing wireless charging integration in modern technology, including wearable devices, this could lead to safer and more accessible solutions in health monitoring, therapeutic and assistive medical technologies. Future work should focus on miniaturisation, advanced modelling and investigating bespoke transducers.