Kreider Wayne, Yuldashev Petr V, Sapozhnikov Oleg A, Farr Navid, Partanen Ari, Bailey Michael R, Khokhlova Vera A
IEEE Trans Ultrason Ferroelectr Freq Control. 2013 Aug;60(8):1683-98. doi: 10.1109/TUFFC.2013.2750.
High-intensity focused ultrasound (HIFU) is a treatment modality that relies on the delivery of acoustic energy to remote tissue sites to induce thermal and/or mechanical tissue ablation. To ensure the safety and efficacy of this medical technology, standard approaches are needed for accurately characterizing the acoustic pressures generated by clinical ultrasound sources under operating conditions. Characterization of HIFU fields is complicated by nonlinear wave propagation and the complexity of phased-array transducers. Previous work has described aspects of an approach that combines measurements and modeling, and here we demonstrate this approach for a clinical phased-array transducer. First, low amplitude hydrophone measurements were performed in water over a scan plane between the array and the focus. Second, these measurements were used to holographically reconstruct the surface vibrations of the transducer and to set a boundary condition for a 3-D acoustic propagation model. Finally, nonlinear simulations of the acoustic field were carried out over a range of source power levels. Simulation results were compared with pressure waveforms measured directly by hydrophone at both low and high power levels, demonstrating that details of the acoustic field, including shock formation, are quantitatively predicted.
高强度聚焦超声（HIFU）是一种治疗方式，它依靠将声能传递到远处的组织部位来诱发热和/或机械性组织消融。为确保这种医疗技术的安全性和有效性，需要有标准方法来精确表征临床超声源在工作条件下产生的声压。HIFU场的表征因非线性波传播和相控阵换能器的复杂性而变得复杂。先前的工作已经描述了一种结合测量与建模的方法的各个方面，在此我们展示了针对临床相控阵换能器的这种方法。首先，在阵列与焦点之间的扫描平面上于水中进行低振幅水听器测量。其次，这些测量被用于通过全息术重建换能器的表面振动，并为三维声传播模型设置边界条件。最后，在一系列源功率水平上对声场进行非线性模拟。将模拟结果与在低功率和高功率水平下通过水听器直接测量的压力波形进行比较，表明包括冲击波形成在内的声场细节能够得到定量预测。
