Numerical simulations of central airway flows with patient-specific geometry and the possible relations to pulmonary function indicators

Numerical simulations of pulmonary airway flow are carried out based on patient-specific geometry reconstructed from computed tomography scans. The study includes four patients, for each patient, three simulations are run on models reconstructed from data acquired in different years. As the flow rate increases, the flow in the trachea and bronchi becomes more vortical and inhomogeneous. The pressure drop between inlet and outlets and the wall shear stress show significant variation among different years due to the change of geometry. The correlation coefficients of four hydrodynamical indicators and pulmonary function tests are then examined. Indicators based on wall shear stress exhibit stronger correlation to pulmonary ventilation indices than those based on pressure drop. Especially, strong correlation is observed between the airway resistance in clinical test and wall shear stress in simulations, suggesting that the current simulations can reasonably capture the flow state in central airway.