Mao Mingqian, Yang Zhichen, Li Mengting, Ni Xiaoyu, Pan Changwang
School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, Jiangsu Province 210037, PR China.
School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, Jiangsu Province 210037, PR China.
Med Eng Phys. 2025 Mar;137:104303. doi: 10.1016/j.medengphy.2025.104303. Epub 2025 Feb 8.
Obstructive lung diseases, marked by airway stenosis, are chronic and pose significant mortality risks. This study aims to analyze airflow patterns in obstructed bronchi, comparing them to healthy airways during tidal breathing to improve our comprehension of disease effects on respiratory function. The current studies mostly overlook the specific morphology of the patient's upper airway or the elastic deformation of the airway soft tissues, which results in the existing results not being sufficient to effectively guide surgical treatment. In this paper, a realistic model of bronchial stenosis was obtained by CT data from a 71-year-old female patient. Full consideration was given to the nonlinear elastic material properties of the tracheal wall cartilage and smooth muscle and the dynamic changes in intra-pulmonary pressure, which are significant factors affecting the airflow field within the airway. The dynamic mesh technology and the Fluid-Structure Interaction (FSI) method, in conjunction with Computational Fluid Dynamics (CFD), were employed to analyze the impact of bilateral bronchial stenosis on the airflow state and the nonlinear mechanical behavior of the airway wall under different respiratory intensities. The simulation results exposed the distribution pattern of key parameters, such as airflow velocity, pressure, wall shear stress, and turbulent kinetic energy, indicating that bronchial stenosis significantly influences the air-flow motion, resulting in increased pressure, wall shear stress, and deformation of the airway wall. The finding revealed that the maximum airflow velocity, pressure, and wall shear stress all occurred in the stenosis areas of the bronchi, while the maximum deformation occurred on the smooth muscle side of the middle part of the main trachea. Additionally, turbulence occurs near the main trachea and carina, potentially related to airflow separation and local geometric changes. These insights contribute to a deeper understanding of the effects of bronchial stenosis on airway airflow dynamics and provide a scientific basis for the determination of clinical treatment plans and the prediction of treatment outcomes.
以气道狭窄为特征的阻塞性肺疾病是慢性疾病，具有较高的死亡风险。本研究旨在分析阻塞性支气管中的气流模式，并将其与潮式呼吸期间的健康气道进行比较，以增进我们对疾病对呼吸功能影响的理解。目前的研究大多忽略了患者上气道的具体形态或气道软组织的弹性变形，导致现有结果不足以有效指导手术治疗。本文通过一名71岁女性患者的CT数据获得了一个逼真的支气管狭窄模型。充分考虑了气管壁软骨和平滑肌的非线性弹性材料特性以及肺内压的动态变化，这些都是影响气道内气流场的重要因素。采用动态网格技术和流固耦合（FSI）方法，并结合计算流体动力学（CFD），分析双侧支气管狭窄对不同呼吸强度下气流状态和气道壁非线性力学行为的影响。模拟结果揭示了气流速度、压力、壁面剪应力和湍动能等关键参数的分布模式，表明支气管狭窄显著影响气流运动，导致压力、壁面剪应力增加以及气道壁变形。研究发现，最大气流速度、压力和壁面剪应力均出现在支气管的狭窄区域，而最大变形发生在主气管中部的平滑肌侧。此外，在主气管和隆突附近会出现湍流，这可能与气流分离和局部几何变化有关。这些见解有助于更深入地理解支气管狭窄对气道气流动力学的影响，并为临床治疗方案的确定和治疗结果的预测提供科学依据。
