Haut Benoit, Karamaoun Cyril, Rigaut Clément
Transfers, Interfaces and Processes, Université libre de Bruxelles, Brussels, Belgium.
PLoS One. 2025 Jan 30;20(1):e0311667. doi: 10.1371/journal.pone.0311667. eCollection 2025.
In this paper, we present a new computational framework for the simulation of airway resistance, the fraction of exhaled nitric oxide, and the diffusion capacity for nitric oxide in healthy and unhealthy lungs. Our approach is firstly based on a realistic representation of the geometry of healthy lungs as a function of body mass, which compares well with data from the literature, particularly in terms of lung volume and alveolar surface area. The original way in which this geometry is created, including an individual definition of the airways in the first seven generations of the lungs, makes it possible to consider the heterogeneous nature of the lungs in terms of perfusion and ventilation. In addition, a geometry can be easily modified to simulate various abnormalities, local or global (constriction, inflammation, perfusion defect). The natural variability of the lungs at constant body mass is also considered. The computational framework includes the possibility to simulate, on a given (possibly modified) geometry, a test to measure the flow resistance of the lungs (including its component due to the not fully developed flow in the first generations of lungs), a test to measure the concentration of nitric oxide in the exhaled air, and a test to measure the diffusion capacity for nitric oxide. This is implemented in the framework by solving different transport equations (momentum and convection/diffusion) describing these tests. Through numerous simulations, we demonstrate the ability of our model to reproduce results from the literature, both for healthy lungs and lungs of patients with asthma or chronic obstructive pulmonary disease. Such a computational framework, through the possibilities of numerous and rapid tests that it allows, sheds new light on experimental data by providing information on the phenomena that take place in the distal generations of the lungs, which are difficult to access with imaging.
在本文中，我们提出了一种新的计算框架，用于模拟健康和不健康肺部的气道阻力、呼出一氧化氮分数以及一氧化氮扩散容量。我们的方法首先基于健康肺部几何形状与体重的函数关系的真实表示，这与文献数据比较吻合，特别是在肺容积和肺泡表面积方面。创建这种几何形状的原始方式，包括对肺部前七代气道的个体定义，使得能够从灌注和通气方面考虑肺部的异质性。此外，可以轻松修改几何形状以模拟各种局部或全局异常（狭窄、炎症、灌注缺陷）。还考虑了恒定体重下肺部的自然变异性。该计算框架包括在给定（可能修改过的）几何形状上模拟测量肺部流动阻力的测试（包括由于肺部第一代未充分发展的流动导致的分量）、测量呼出空气中一氧化氮浓度的测试以及测量一氧化氮扩散容量的测试的可能性。这是通过求解描述这些测试的不同传输方程（动量和对流/扩散）在框架中实现的。通过大量模拟，我们证明了我们的模型能够重现文献中关于健康肺部以及哮喘或慢性阻塞性肺疾病患者肺部的结果。这样一个计算框架，通过其允许进行大量快速测试的可能性，通过提供关于肺部远端几代中发生的难以通过成像获取的现象的信息，为实验数据提供了新的见解。
