论文标题
符合符合气道树的墙剪应力分布
Wall shear stress distribution in a compliant airway tree
论文作者
论文摘要
支气管中的气流在支气管粘液上施加剪切应力，可以移动粘液。空气互动在咳嗽和胸部物理疗法（CP）中起着重要作用。它诱导粘液位移的条件尚不清楚。然而，空气相互作用证明了CP的常见技术合理，用于帮助流行疾病中的粘液排出。因此，确定肺中剪切应力的分布对于理解这些疗法的影响以及可能提高其效率至关重要。我们开发了一个数学模型，以研究由空气道的气流引起的壁剪应力（WSS）的分布。该模型解释了确定WSS的主要物理过程，尤其是气道，空气惯性和树木结构的合规性。我们表明，树上的WSS分布取决于气道变形的动力学和空气惯性。树上的WSS分布表现出最大值，其幅度和位置取决于气流的量以及围绕气道的“组织”压力。为了表征WSS在树分叉中的行为，我们得出了与分叉中气道尺寸降低有关的新分析标准。我们的结果表明，在CP机动过程中，对气流和组织压力进行调整可能至少可以部分控制肺中的气流 - 菌相互作用。
The airflow in the bronchi applies a shear stress on the bronchial mucus, which can move the mucus. The air--mucus interaction plays an important role in cough and in chest physiotherapy (CP). The conditions under which it induces a displacement of the mucus are still unclear. Yet, the air--mucus interaction justifies common technics of CP used to help the draining of the mucus in prevalent diseases. Hence, the determination of the distribution of the shear stress in the lung is crucial for understanding the effects of these therapies and, potentially, improve their efficiency. We develop a mathematical model to study the distribution of the wall shear stress (WSS) induced by an air flow exiting an airway tree. This model accounts for the main physical processes that determines the WSS, more particularly the compliance of the airways, the air inertia and the tree structure. We show that the WSS distribution in the tree depends on the dynamics of the airways deformation and on the air inertia. The WSS distribution in the tree exhibits a maximum whose amplitude and location depend on the amount of air flow and on the "tissue" pressure surrounding the airways. To characterize the behavior of the WSS at the tree bifurcations, we derive new analytical criteria related to the airway size reduction in the bifurcations. Our results suggest that a tuning of the airflow and of the tissue pressure during a CP maneuver might allow to control, at least partially, the air--mucus interaction in the lung.
