An ultrasound power supply (100) adapted for supplying electrical power for driving an ultrasound transducer (202, 702) in contact with a subject (208), wherein the ultrasound power supply comprises:—a communications interface (102) adapted for receiving a first temperature measurement of a first volume (211, 318) of the subject and a second temperature measurement of a second volume (214, 320) of the subject；—a controller (108) adapted for modulating the output of electrical power for driving the ultrasound transducer such that via ultrasonic heating by the ultrasound transducer: a. the first temperature measurement is maintained above a first predetermined threshold, b. the first temperature measurement is maintained below a second predetermined threshold, and c. the second temperature measurement is maintained below a third predetermined threshold； and wherein the first predetermined threshold is above the third predetermined threshold.
