Determining attenuation properties of interfering fast and slow ultrasonic waves in cancellous bone.
Determining attenuation properties of interfering fast and slow ultrasonic waves in cancellous bone.
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DOI：
10.1121/1.3625241
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
A. M. Nelson;J. J. Hoffman-J.;C. C. Anderson-C.;M. Holland;Y. Nagatani;K. Mizuno;M. Matsukawa;James G. Miller
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文献类型：
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作者：
A. M. Nelson;J. J. Hoffman-J.;C. C. Anderson-C.;M. Holland;Y. Nagatani;K. Mizuno;M. Matsukawa;James G. Miller
以前的研究表明，快波和慢波之间的干扰可以导致观察到的负分散在松质骨。在这项研究中，重叠的快波和慢波对测量的表观衰减作为传播距离的函数的影响进行了研究沿着与用于确定衰减特性的分析方法。两种方法被施加到模拟数据，产生的基础上从牛标本实验获得的信号。第一种方法使用时域方法，该方法由快波和慢波的部分重叠所施加的约束决定。第二种方法使用频域对数谱减法技术上分离的快，慢波。将时域分析应用于宽带数据产生明显的衰减行为，该衰减行为在传播的早期阶段较大，并且随着波行进得更深而减小。相反，对分离的快波和慢波执行频域分析导致与传播距离无关的衰减系数。结果表明，重叠的双模式数据的分析所产生的功能可能代表了先前报道的松质骨的衰减系数的传播距离的明显依赖的另一种解释。
Previous studies have shown that interference between fast waves and slow waves can lead to observed negative dispersion in cancellous bone. In this study, the effects of overlapping fast and slow waves on measurements of the apparent attenuation as a function of propagation distance are investigated along with methods of analysis used to determine the attenuation properties. Two methods are applied to simulated data that were generated based on experimentally acquired signals taken from a bovine specimen. The first method uses a time-domain approach that was dictated by constraints imposed by the partial overlap of fast and slow waves. The second method uses a frequency-domain log-spectral subtraction technique on the separated fast and slow waves. Applying the time-domain analysis to the broadband data yields apparent attenuation behavior that is larger in the early stages of propagation and decreases as the wave travels deeper. In contrast, performing frequency-domain analysis on the separated fast waves and slow waves results in attenuation coefficients that are independent of propagation distance. Results suggest that features arising from the analysis of overlapping two-mode data may represent an alternate explanation for the previously reported apparent dependence on propagation distance of the attenuation coefficient of cancellous bone.