An iterative method for the computation of nonlinear, wide-angle, pulsed acoustic fields of medical diagnostic transducers.
An iterative method for the computation of nonlinear, wide-angle, pulsed acoustic fields of medical diagnostic transducers.
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一种用于计算医疗诊断换能器的非线性、广角、脉冲声场的迭代方法。
DOI：
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发表时间：
2010
影响因子：
2.4
通讯作者：
M. Verweij
中科院分区：
文献类型：
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作者：
J. Huijssen;M. Verweij
医学超声换能器和成像模式的开发和优化需要一种能够准确预测非线性声压场的计算方法。前瞻性方法应提供由任意平面源分布发射的广角脉冲场，并在包含非线性声介质的三维大尺度域中传播。在本文中，提出了一种不考虑任何假设的波场方向性的方法。通过将非线性项作为对比源来求解非线性声波方程。该公式产生了一个迭代方案，该方案涉及通过格林函数方法重复求解线性波问题。结果表明，可以在几次迭代内获得准确的场预测。此外，通过采用专用的数值卷积技术，该方法允许将感兴趣的最高频率的每个波长或周期离散化至两个点。该方法的性能通过对各种几何形状的脉冲换能器进行大量非线性场预测来评估。结果证明了该方法的方向独立性。此外，与现有几种方法的结果比较表明，该方法可以准确地预测弱到中度非线性的非线性场。
The development and optimization of medical ultrasound transducers and imaging modalities require a computational method that accurately predicts the nonlinear acoustic pressure field. A prospective method should provide the wide-angle, pulsed field emitted by an arbitrary planar source distribution and propagating in a three-dimensional, large scale domain holding a nonlinear acoustic medium. In this paper, a method is presented that is free of any assumed wavefield directionality. The nonlinear acoustic wave equation is solved by treating the nonlinear term as a contrast source. This formulation leads to an iterative scheme that involves the repetitive solution of a linear wave problem through Green's function method. It is shown that accurate field predictions may be obtained within a few iterations. Moreover, by employing a dedicated numerical convolution technique, the method allows for a discretization down to two points per wavelength or period of the highest frequency of interest. The performance of the method is evaluated through a number of nonlinear field predictions for pulsed transducers with various geometries. The results demonstrate the directional independence of the method. Moreover, comparison with results from several existing methods shows that the method accurately predicts the nonlinear field for weak to moderate nonlinearity.