Yuan Jiayao, Chiofolo Caitlyn M, Czerwin Benjamin J, Karamolegkos Nikolaos, Chbat Nicolas W
Columbia University New York NY 10027 USA.
Quadrus Medical Technologies New York NY 10001 USA.
IEEE Open J Eng Med Biol. 2021 Jan 22;2:44-54. doi: 10.1109/OJEMB.2021.3053841. eCollection 2021.
Alveolar compliance is a main determinant of lung airflow. The compliance of the alveoli is a function of their tissue fiber elasticity, fiber volume, and surface tension. The compliance varies during respiration because of the nonlinear nature of fiber elasticity and the time-varying surface tension coating the alveoli. Respiratory conditions, like acute respiratory distress syndrome (ARDS) and idiopathic pulmonary fibrosis (IPF) affect fiber elasticity, fiber volume and surface tension. In this paper, we study the alveolar tissue fibers and surface tension effects on lung mechanics. To better understand the lungs, we developed a physiology-based mathematical model to 1) describe the effect of tissue fiber elasticity, fiber volume and surface tension on alveolar compliance, and 2) the effect of time-varying alveolar compliance on lung mechanics for healthy, ARDS and IPF conditions. We first present the model sensitivity analysis to show the effects of model parameters on the lung mechanics variables. Then, we perform model simulation and validate on healthy non-ventilated subjects and ventilated ARDS or IPF patients. Finally, we assess the robustness and stability of this dynamic system. We developed a mathematical model of the lung mechanics comprising alveolar tissue and surfactant properties that generates reasonable lung pressures and volumes compared to healthy, ARDS, and IPF patient data.
肺泡顺应性是肺气流的主要决定因素。肺泡的顺应性取决于其组织纤维弹性、纤维体积和表面张力。由于纤维弹性的非线性性质以及覆盖肺泡的时变表面张力，顺应性在呼吸过程中会发生变化。诸如急性呼吸窘迫综合征（ARDS）和特发性肺纤维化（IPF）等呼吸状况会影响纤维弹性、纤维体积和表面张力。在本文中，我们研究肺泡组织纤维和表面张力对肺力学的影响。为了更好地理解肺部，我们开发了一个基于生理学的数学模型，以1）描述组织纤维弹性、纤维体积和表面张力对肺泡顺应性的影响，以及2）时变肺泡顺应性对健康、ARDS和IPF状况下肺力学的影响。我们首先进行模型敏感性分析，以展示模型参数对肺力学变量的影响。然后，我们在健康的非通气受试者以及通气的ARDS或IPF患者身上进行模型模拟和验证。最后，我们评估这个动态系统的稳健性和稳定性。我们开发了一个包含肺泡组织和表面活性剂特性的肺力学数学模型，与健康、ARDS和IPF患者数据相比，该模型能产生合理的肺压力和肺容积。
