Integrated ultrasound sensor for microwave heating and radiometry in medical applications

A water bolus is essential to cool the skin temperature during microwave heating of human tissue. This paper describes the importance of an accurate measurement of the water bolus thickness, and propose the use of a thin piezoelectric film transducer beneath the microwave antenna to perform this task. Results shows that although the electromagnetical field from the microwave antennas are effected by this ultrasound transducer, this integrated sensor gives robust and accurate thickness measurements that can improve the safety of microwave heating systems.