Comparison of Poroviscoelastic Models for Sound and Vibration in the Lungs
Comparison of Poroviscoelastic Models for Sound and Vibration in the Lungs
复制标题
DOI：
10.1115/1.4026436
复制
发表时间：
2014-10-01
影响因子：
1.7
通讯作者：
Royston, Thomas J.
中科院分区：
文献类型：
--
作者：
Dai, Zoujun;Peng, Ying;Royston, Thomas J.
肺部机械波运动（声音和振动）的非侵入性测量可能具有诊断价值，因为它可以提供有关肺部机械特性的信息，而这些信息又会受到疾病和损伤的影响。在这项研究中，两个先前推导出的肺实质的振动声学行为的理论模型进行了比较：（1）孔隙粘弹性的毕奥理论和（2）压缩波行为的有效介质理论（也称为“气泡群”模型）。剪切粘弹性的分数导数公式被集成到这两个模型中。由毕奥理论公式预测的可测量的“快”压缩波速度具有有效介质理论未预测的显著频率依赖性。毕奥理论也预言了一个缓慢的压缩波。在猪肺离体模型中实验测量的快速压缩波速度和衰减与毕奥理论一致。为了获得用于毕奥理论预测的参数，进行以下实验：进行准静态机械压痕测量以估计肺静态剪切模量;进行表面波测量以估计肺组织剪切粘弹性;以及在干燥的肺标本上测量流动渗透性。这项研究表明，毕奥理论可以提供一个更强大的和准确的模型比有效介质理论的波传播在肺部在更宽的频率范围。
Noninvasive measurement of mechanical wave motion (sound and vibration) in the lungs may be of diagnostic value, as it can provide information about the mechanical properties of the lungs, which in turn are affected by disease and injury. In this study, two previously derived theoretical models of the vibroacoustic behavior of the lung parenchyma are compared: (1) a Biot theory of poroviscoelasticity and (2) an effective medium theory for compression wave behavior (also known as a "bubble swarm" model). A fractional derivative formulation of shear viscoelasticity is integrated into both models. A measurable "fast" compression wave speed predicted by the Biot theory formulation has a significant frequency dependence that is not predicted by the effective medium theory. Biot theory also predicts a slow compression wave. The experimentally measured fast compression wave speed and attenuation in a pig lung ex vivo model agreed well with the Biot theory. To obtain the parameters for the Biot theory prediction, the following experiments were undertaken: quasistatic mechanical indentation measurements were performed to estimate the lung static shear modulus; surface wave measurements were performed to estimate lung tissue shear viscoelasticity; and flow permeability was measured on dried lung specimens. This study suggests that the Biot theory may provide a more robust and accurate model than the effective medium theory for wave propagation in the lungs over a wider frequency range.