MECHANICAL PROPERTIES OF LUNG PARENCHYMA TISSUE

肺变形能力对肺功能有重要影响。 为 例如，不均匀的变形可能会损害气体交换或变化， 肺血管阻力 在分析这些变形时， 了解肺的机械特性。 的目标 本研究的目的是建立一个本构方程， 肺的机械特性。 最简单的构成形式 方程，其特征在于 弹性固体中的一个方程是线性方程，称为胡克定律。 上 作为该项目的一部分，肺实质组织的胡克定律将是 从测量的线性弹性系数，剪切 弹性模量和体积模量。 先前 在这些测量中将使用先进的实验技术; 测量剪切模量的冲压压痕试验和叠加 主要压力-容积曲线上的小压力-容积环来测量 体积模量 通过比较填充液体的 肺与从充满空气的肺获得的那些，将有可能 评估实质组织网络在抵抗 肺的体积和形状变形，而不是界面 表面张力 在项目的第二部分， Wilson和Bachofen的肺模型将被扩展， 以前被忽视的肺泡壁网络。 组成型 方程将从扩展模型中导出。 这个等式将 产生更好的大小非均匀的定量预测 肺的变形比从模型中获得的预测， 肺泡膜被忽略了。

Lung deformability has an important effect on pulmonary function. For example, a nonuniform deformation can impair gas exchange or change pulmonary vascular resistance. In analyzing these deformations, it is necessary to know the mechanical properties of the lung. The objective of this study is to formulate a constitutive equation that describes mechanical properties of the lung. The simplest form of the constitutive equation that characterizes uniform and nonuniform deformations of an elastic solid is the linear equation, known as Hooke's law. In the first part of this project, Hooke's law for lung parenchyma tissue will be derived from measurements of the linear elastic coefficients, the shear modulus and the bulk modulus, of the liquid-filled rabbit lung. Previously developed experimental techniques will be used in these measurements; the punch indentation test for measuring the shear modulus, and superposition of small pressure-volume loops on the main pressure-volume curve to measure the bulk modulus. By comparing the elastic moduli of the liquid-filled lung with those obtained from the air-filled lung, it will be possible to assess the significance of the parenchymal tissue network in resisting volume and shape distortions of the lung, as opposed to the interfacial surface tension. In the second part of the project, the microstructural model of the lung of Wilson and Bachofen will be extended by including previously neglected network of the alveolar walls. A constitutive equation will be derived from the extended model. This equation would yield better quantitative predictions of large and small nonuniform deformations of the lung than the predictions obtained from the model in which the alveolar membranes have been neglected.