Measurement of high intensity focused ultrasound fields by a fiber optic probe hydrophone
Measurement of high intensity focused ultrasound fields by a fiber optic probe hydrophone
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DOI：
10.1121/1.2214131
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发表时间：
2006-08-01
影响因子：
2.4
通讯作者：
Zhong, Pei
中科院分区：
文献类型：
--
作者：
Zhou, Yufeng;Zhai, Liang;Zhong, Pei
用光纤探头水听器测量了工作在基频(1.1 MHz)和三次谐波(3.3 MHz)频率下的高强度聚焦超声(HIFU)换能器的声场。在1.1 MHz频率下，当施加到换能器的电功率从1.6 W增加到125W时，焦点处的峰值正负压分别为P+=1.7-23.3 Mpa和p=-1.2-10.0 Mpa。相应的空间峰值脉冲平均强度(I-SPPA)和空间平均脉冲平均强度(I-SAPA)分别为I-SPPA=77-6000W/cm(2)和ISAPA=35-4365W/cm(2)。在高强度下，产生谐波的非线性传输占主导地位，导致纵波(11.5x1.8-8.8x1.04min)的光束尺寸(L XW)减小-6dB，而稀疏波(12.5x1.6-13.2x2.0 mm)的光束尺寸增大。水中吸收功率密度的增强比从1.0提高到3.0。相比之下，工作在3.3 MHz的HIFU换能器产生了较高的峰值压力(p(+)=3.0~35.1 Mpa和p(-)=-2.5~13.8 Mpa)，而束流尺寸较小(0.5×4 mm)。总体而言，FOPH被发现是HIFU暴露测量的一种方便和可靠的工具。(C)2006年美国声学学会。
The acoustic fields of a high intensity focused ultrasound (HIFU) transducer operating either at its fundamental (1.1 MHz) or third harmonic (3.3 MHz) frequency were measured by a fiber optic probe hydrophone (FOPH). At 1.1 MHz when the electric power applied to the transducer was increased from 1.6 to 125 W, the peak positive/negative pressures at the focus were measured to be P+= 1.7-23.3 MPa and p =-1.2-10.0 MPa. The corresponding spatial-peak pulse-average (I-SPPA) and spatial-average pulse-average (I-SAPA) intensities were I-SPPA=77-6000 W/cm(2) and ISAPA =35-4365 W/cm(2). Nonlinear propagation with harmonics generation was dominant at high intensities, leading to a reduced -6 dB beam size (L X W) of the compressional wave (11.5 x 1.8-8.8 X 1.04 min) but an increased beam size of the rarefactional wave (12.5 X 1.6-13.2 x 2.0 mm). Enhancement ratio of absorbed power density in water increased from 1.0 to 3.0. In comparison, the HIFU transducer working at 3.3 MHz produced higher peak pressures (p(+) =3.0-35.1 MPa and p(-) =-2.5-13.8 MPa) with smaller beam size (0.5 X 4 mm). Overall, FOPH was found to be a convenient and reliable tool for HIFU exposimetry measurement. (c) 2006 Acoustical Society of America.