Experimental Testbed for Ultrasonic Wireless Power Transfer and Backscattering Based Localization for Future Implantable Devices

The development of an autonomous tracking system which could accurately locate and transfer higher quantities of power wirelessly to deep-tissue catheter implants in a cost-effective manner would prove very useful in medicine. This work presents a backscatter-based energy transfer and tracking system for future deep-tissue implants. To transfer power, an open-top ultrasonic transducer would be placed near the skin, the ultrasonic wave can power circuits on the tip of the catheter inside the patient. For the tracking system, transducers use ultrasonic backscattering and time-of-arrival to precisely locate the tip of the catheter. To show this concept will work in future applications, the two major components of the system were tested and validated using commercial off-the-shelf devices with air as medium. We were able to show a one-way 0.34mm localization resolution and track an object in two dimensions with 6.32mm accuracy on the x-axis and 4.27mm on the y-axis. Ultrasonic Wireless Power Transfer (WPT) was modeled using a linear rectangular array approximation via an open-source MATLAB Toolbox known as k-Wave. The developed array model was experimentally validated at distances from 11mm to 310mm using a linear rectangular array approximation of commercially available transducers for transfer efficiencies through air of up to 81.9 percent.