Wireless power transmission in human tissue for nerve stimulation

Wireless power transmission in human tissue using microwave techniques has great potential for different biomedical applications. Characterisation and optimisation of these techniques using in vivo performance measurements are complicated and time consuming. This study investigates the electromagnetic performance of microwave wireless power transmission at 2.45 GHz. For this purpose, a computational model of a measurement system is proposed and used to characterise and optimise a microwave wireless power transmission technique capable of delivering microwave power to a localised area in the human tissue. This technique includes an implanted miniature encased microstrip ring disk antenna and an external microstrip patch antenna operating at 2.45 GHz. The results show that the microwave technique can be optimised by matching the radiation directions and polarisations of the antennas and by inserting a dielectric layer between the human tissue and the external antenna. It is demonstrated that the optimised microwave technique can deliver an electrical stimulus that can be used for biomedical applications such as nerve regeneration with a specific absorption rate that satisfies the IEEE Standards.