Acoustic power measurement of high-intensity focused ultrasound transducer using a pressure sensor

摘要

The acoustic power of high-intensity focused ultrasound (HIFU) is an important parameter that should be measured prior to each treatment to guarantee effective and safe outcomes. A new calibration technique was developed that involves estimating the pressure distribution, calculating the acoustic power using an underwater pressure blast sensor, and compensating the contribution of harmonics to the acoustic power. The output of a clinical extracorporeal HIFU system (center frequency of similar to 1 MHz, p(+) = 2.5-57.2 MPa, p(-) = -1.8 to -13.9 MPa, I-SppA = 513-22,940 W/cm(2), -6 dB size of 1.6 x 10 mm: lateral x axial) was measured using this approach and then compared with that obtained using a radiation force balance. Similarities were found between each method at acoustic power ranging from 18.2 W to 912 W with an electrical-to-acoustic conversion efficiency of similar to 42%. The proposed method has advantages of low weight, smaller size, high sensitivity, quick response, high signal-to-noise ratio (especially at low power output), robust performance, and easy operation of HIFU exposimetry measurement. (C) 2015 IPEM. Published by Elsevier Ltd. All rights reserved.