Sehgal C M, Bahn R C, Greenleaf J F
J Acoust Soc Am. 1984 Oct;76(4):1023-9. doi: 10.1121/1.391420.
A thermodynamic method for measuring the acoustic nonlinearity parameter B/A in tissues is presented. It is based on the measurement of change in phase velocity as a function of time as the hydrostatic pressure of the sample is quickly reduced from a known value. This technique circumvents the effect of the attenuation in the medium and does not require a prior knowledge of the thermodynamic parameters of the tissues. The method is used to estimate nonlinearity parameters for normal and malignant tissues in the temperature range 20 degrees to 37 degrees C. The values and the temperature dependence of these parameters are found to vary with the nature of the tissues.
提出了一种用于测量组织中声非线性参数B/A的热力学方法。该方法基于在样品的静水压力从已知值快速降低时，测量相速度随时间的变化。这种技术规避了介质中衰减的影响，并且不需要预先了解组织的热力学参数。该方法用于估计20摄氏度至37摄氏度温度范围内正常组织和恶性组织的非线性参数。发现这些参数的值及其温度依赖性随组织的性质而变化。
