Ultrasonic interstitial heating in phantoms

Interstitial heating was achieved with an ultrasonic applicator made of an acoustic waveguide attached to a planar piezoelectric transducer, operated at about 1 MHz. A hyperthermia of 6.5-13.5 degrees C was observed in two phantoms. After a linear initial rise, the temperature reached a plateau. The final temperature depends on a power applied, initial rate of heating, and, to a smaller degree, on the type of phantom. An interpretation, of the results based on the Hankel integral solution to the heat equation is presented.<>