Closed-loop ultrasonic power and communication with multiple miniaturized active implantable medical devices

An ultrasonic array system is designed for wirelessly powering and communicating with implantable medical devices. A flexible hardware interface is used to drive a 32-element linear phased array with emphasis on programmability and efficiency rather than bandwidth or peak power. Various beam patterns and data modulation schemes are verified at a depth of 6 cm in a tissue phantom with more than sufficient harvested power for typical implant applications. The power transfer efficiency is also characterized versus depth. Finally, a closed-loop test is performed with two mm-sized devices demonstrating both power and data transfer. This system provides a platform for more complex adaptive therapies combining sensing, communication, and stimulation.