ABSTRACT
Ultrasound therapy is a new type of therapy technology, there are hyperthermia and high intensity focused ultrasound surgery (HIFUS). Compared with a single frequency system, mutiple frequency system has an additional function to combine power patterns of different frequencies. This function increases the availability of power patterns to treat tumors of various shapes and depths. Therefore, we have in this article proposed a system with the ability to drive ultrasonic phased arrays of multiple resonant frequencies for ultrasound hyperthermia and HIFUS. The results show that this system is able to (1) drive multi-element applicators or phased arrays of a single resonant frequency through the multichannel power amplifiers, (2) concurrently drive transducer with different resonant frequencies, (3) adjust the relative phase and output power of each channel for the scanning ultrasonic focus, and (4) operate each channel with good output stability.