Key Laboratory of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China.
J Acoust Soc Am. 2011 Dec;130(6):4117-25. doi: 10.1121/1.3658471.
The fundamental framework of doublet mechanics (DM) is used to analyze high-frequency ultrasound wave propagation in materials with discrete microstructure. Ultrasonic reflection coefficients were measured from a thin layer of tissue embedded between two glass substrates at oblique incidence. Theoretical calculations for the reflection coefficients of a multi-layered system at oblique angles are performed using both DM theory and the classical continuum mechanics theory (CCM). For example, at the frequency of 10 MHz at incident angle 8° in sample with 30 μm thickness, the discrepancy in the magnitude of the reflection coefficient between experimental results and theoretical prediction is 15.8% for DM but 79.0% for CCM; similar results at other frequencies and incident angle in the samples with 30 and 60 μm thickness have also been obtained, which demonstrates that the DM theory can better describe the wave propagation in tissue. The influence of the incident angles and tissue thickness are also discussed in this paper.
采用双相介质力学（DM）基本框架分析了具有离散微观结构的材料中的高频超声波传播。通过斜入射在两个玻璃基板之间嵌入的薄组织层测量超声反射系数。使用 DM 理论和经典连续介质力学理论（CCM）对多层系统在斜角的反射系数进行了理论计算。例如，在频率为 10MHz、入射角为 8°的情况下，对于厚度为 30μm 的样品，DM 理论的实验结果与理论预测的反射系数幅度差异为 15.8%，而 CCM 理论的差异为 79.0%；在厚度为 30μm 和 60μm 的样品中，在其他频率和入射角下也得到了类似的结果，这表明 DM 理论可以更好地描述组织中的波传播。本文还讨论了入射角和组织厚度的影响。
