Model and experimental analysis of oblique incident ultrasound in a tissue layer using doublet mechanics theory

作者:Jiang, Xin; Liu, Xiaozhou*; Gong, Xiufeng; Zhang, Fei; Wu, Rongrong; Wu, Junru; Liu, Jun
来源:Journal of the Acoustical Society of America, 2011, 130(6): 4117-4125.
DOI:10.1121/1.3658471

摘要

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 degrees in sample with 30 mu m 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 mu m 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.