Computational Modelling for CT-Based Geometry of Actual Human Tracheobronchial Tree for Patients With ARDS

Acute Respiratory Distress Syndrome (ARDS) is caused due to infection of the lungs leading to respiratory failure. It includes the recent worldwide pandemic causing Corona Virus Disease (COVID. ARDS is commonly associated with high patient mortality rates as treatment requires the use of mechanical ventilation that can potentially lead to complications termed as Ventilator Induced Lung Injury (VILI). The objective of this study is to enumerate mechanisms leading to VILI. A computational fluid dynamics (CFD) model is developed and implemented to study the velocity profiles, flow rates and pressure distribution in an actual healthy human tracheobronchial airway geometry. The flow patterns are obtained for each of the 14 bifurcations considered in the airway network from the piecewise CFD simulations of the G0-G4 airway of a single healthy lung model. The simulations for five different inlet flowrates corresponding to Reynolds number (Re) 100, 500, 1000, 1500 and 2000 are conducted within the laminar flow regime. To improve the cognition of the dynamics and mechanics of flow in the bifurcations of lung airways using a Computed Tomography (CT) based geometry, this study considers suitable assumptions for the computational model. The resulting contours are reported for the asymmetric velocity profiles and the pressure patterns along with discussions to highlight its implications. This study successfully demonstrated a computational model and identified the sensitive areas in the actual lung airway geometry. This work is preliminary to developing a prediction tool using lumped parameter and reduced order model for treating patients with ARDS.