The Effect of Treatment Time and Frequency Difference on Acoustic Power of High-intensity Focused Ultrasound

HIFU is a noninvasive tissue ablation method for treatment of a broad range of cancer and benign maladies. Its ultrasonic energy can also be used to activate or deactivate nerves in recent years. To avoid unnecessary tissue ablation caused by high acoustic energy, treatment time is split. Dual-frequency ultrasound takes advantage of cavitation, but in many cases, increases the complexity of the HIFU system. The objective of this research was to measure the acoustic power of HIFU transducer with split treatment time, and compare it with that of the transducer with traditional treatment time. The effect of frequency difference on acoustic power of dual-frequency HIFU transducer is also evaluated in experiments. The results demonstrate that split treatment time has little effect on acoustic power. As frequency difference increases, the acoustic power does not decrease monotonically. Nevertheless, if frequency difference is above 10kHz, the acoustic power significantly decreases compared with that of smaller frequency differences. For dual-frequency HIFU, appropriate frequency difference should be chosen according to their respective application.