超声导波频散曲线反演皮质骨参数的研究  

Cortical bone parameters inversion based on the dispersion curves of ultrasonic guided waves

作　　者：樊天地 宋小军 FAN Tiandi;SONG Xiaojun(College of Electronics and Information Engineering,Shanghai University of Electric Power,Shanghai,201306,China;Biomedical Engineering Center,Fudan University,Shanghai,200433,China)

机构地区：[1]上海电力大学电子与信息工程学院,上海201306 [2]复旦大学生物医学工程中心,上海200433

出　　处：《声学技术》2023年第1期46-51,共6页Technical Acoustics

基　　金：博士后面上基金项目(2019M661334)资助。

摘　　要：皮质骨参数的变化可以反映骨质的健康状况,因此文章提出了一种频散能量匹配算法来反演皮质骨参数。首先,通过频散特性方程计算出预定义参数下的频散曲线数据库;其次,利用时域有限差分算法建立皮质骨声场模型,将仿真的时域信号通过功率谱估计得到频散能量信息,并与数据库进行匹配,通过分析匹配结果的能量从而得到皮质骨的厚度、纵波速度和横波速度。仿真结果显示:与理论值相比,厚度的平均相对误差为3.8%,纵波速度与横波速度的平均相对误差分别为0.6%、0.9%。对三组离体牛胫骨皮质骨进行反演,离体实验结果显示:与真实值相比,厚度相对误差为4.9%,且实验频散曲线与反演得到的理论频散曲线吻合。因此文中所提出的反演算法可以有效获取皮质骨的厚度,横波速度和纵波速度,从而为评价骨质的健康状况提供可靠的依据。The changes of cortical bone parameters can reflect the health of bone, so a dispersion energy matching algorithm is proposed to invert cortical bone parameters. Firstly, the dispersion curve database under predefined parameters is calculated by the dispersion characteristic equation;Secondly, the sound field model of cortical bone is established by using the finite difference time domain(FDTD) method, the simulated time domain signal is estimated through the power spectrum to obtain the dispersion energy information and it is matched with the database, then, the thickness of the cortical bone, the longitudinal wave velocity and the transverse wave velocity are obtained by analyzing the energy value of the matching result. The simulation results show that compared with the theoretical value, the average relative error of thickness is 3.8%, and the average relative errors of longitudinal wave velocity and transverse wave velocity are 0.6% and 0.9% respectively. The parameter inversions for three groups of isolated bovine tibial cortical bones are performed. The in vitro experimental results show that the relative error of thickness is 4.9%compared with the real value, and the experimental dispersion curve is consistent with the theoretical dispersion curve obtained from the inversion. The inversion algorithm proposed in this paper can effectively obtain the thickness,transverse wave velocity and longitudinal wave velocity of cortical bone, so as to provide a reliable basis for evaluating bone health.

关 键 词：超声导波 频散曲线 皮质骨 参数反演 

分 类 号：TB559[理学—物理]