Power Evaluation of High Intensity Focused Ultrasound Transducer Based on Acoustic Filed Measurement in Pre-focal Region

Abstract A novel technique for measurement of high intensity focused ultrasound output power of a transducer was introduced in this study. A needle point hydrophone, which was fixed in the pre-focal region of the transducer by a scanning system, was used to measure the acoustic pressure in both amplitude and phase. By using sound pressure method, the predicated power at pocus was calculated and compared with the actual measured one. It was found that the uncertainty between the measured and calculated acoustic power was about 10%. The near field measurement method is applicable to the evaluation of the focused transducer, and it can avoid the damage to measuring equipment of direct measurement.