用回波重建法分离软组织的超声反射波与散射波

Separation of soft tissue reflected and scattered ultrasonic waves by echo reconstruction method

提出用计算机仿真重建反射回波，以分离软组织超声反射与散射波的方法。该法不仅 能考虑到超声波在传播过程中幅度的衰减，还能够考虑到频率构成的变化。为实现该法，在以 前模型的基础上建立了各层衰减系数不同的分层介质超声传播模型，形成了估计各层衰减系 数与各界面反射系数的有效方法。为提高衰减系数估计中谱分析对噪声的稳健性，提出并采用 了冗余自相关算法。用计算机仿真实验与生物组织仿真模块实验验证了上述方法的有效性。

Based on computer simulated reconstruction of echos,a method is developed to separate ultrasonic echos reflected and scattered by soft tissue. This method puts not only the amplitude attenuation but also the frequency ingredients variation of propagating ultrasonic waves into consideration. To implement this method, an originally developed multi--layered medium model of ultrasonic propagation has been modified to allow for different attenuation coefficients of different layers,and some effective methods of estimating attenuation and reflection coefficients are developed. For the sake of robustness of attenuation coefficient estimation, a new method, namely redundant auto--correlation algorithm, is proposed. Computer simulations and phantom experiments are carried out,and the effectiveness of the methods is verified.