Statistical estimation of ultrasonic propagation path parameters for aberration correction.
Statistical estimation of ultrasonic propagation path parameters for aberration correction.
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用于像差校正的超声波传播路径参数的统计估计。
DOI：
10.1109/tuffc.2005.1503972
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Astheimer,JeffreyP
中科院分区：
文献类型：
--
作者：
Waag,RobertC;Astheimer,JeffreyP
超声波传播的线性滤波器模型中的参数，发现使用统计估计。该模型采用了非相干介质的绿色函数，并将其分解为非相干传输项和与光路相关的像差项。随机介质散射的功率谱和互功率谱估计的频率范围内的发射-接收系统，通过使用接近位于散射体积。从功率谱的归一化获得频域像差的幅度。通过递推的方法，从相邻接收位置的子孔径信号的互功率谱中重构出相应的相位。子孔径约束接收灵敏度图案以消除测量系统相位贡献。递归使用基于拉普拉斯的算法从相位差获得相位。脉冲回波波形从一个点反射器和一个组织样散射体模通过一个仿组织的像差路径从相邻的体积具有基本上相同的aberrationpath. Propagationparameters计算的随机散射通过像差体模的测量与相应的参数计算相同的aberrator和阵列位置通过使用从点反射器的回波。结果表明，该方法描述，除了时间移位，波形幅度和形状的变化所产生的传播通过分布像差在现实条件下。
Parameters in a linear filter model for ultrasonic propagation are found using statistical estimation. The model uses an inhomogeneous-medium Green's function that is decomposed into a homogeneous-transmission term and a path-dependent aberration term. Power and cross-power spectra of random-medium scattering are estimated over the frequency band of the transmit-receive system by using closely situated scattering volumes. The frequency-domain magnitude of the aberration is obtained from a normalization of the power spectrum. The corresponding phase is reconstructed from cross-power spectra of subaperture signals at adjacent receive positions by a recursion. The subapertures constrain the receive sensitivity pattern to eliminate measurement system phase contributions. The recursion uses a Laplacian-based algorithm to obtain phase from phase differences. Pulse-echo waveforms were acquired from a point reflector and a tissue-like scattering phantom through a tissue-mimicking aberration path from neighboring volumes having essentially the same aberration path. Propagation path aberration parameters calculated from the measurements of random scattering through the aberration phantom agree with corresponding parameters calculated for the same aberrator and array position by using echoes from the point reflector. The results indicate the approach describes, in addition to time shifts, waveform amplitude and shape changes produced by propagation through distributed aberration under realistic conditions.