Computational fluid dynamics study of the effect of posture on airflow characteristics inside the nasal cavity

Abstract

Background: Postural changes in nasal airway resistances are of clinical importance when assessing patientswith nasal obstruction. Computed tomography (CT) that is used in computational fluid dynamics (CFD) studiesis obtained in a supine position, and it is therefore important to identify whether different positions such assupine, prone, and standing/sitting have any influence on flow behavior inside the nasal cavity. Objectives: To study the effect of posture on modeling nasal airflow and evaluate its influence in determiningwall shear stress and other parameters. Method: A three-dimensional nasal cavity model was constructed based on CT images of a healthy Malaysianadult nose. Navier-Stokes and continuity equations for steady airflow were solved to examine inspiratory nasalflow. Results: Around a 0.3% change in the average static pressure is observed while changing from a sitting to supineposition. A significant drop in velocity was seen while shifting from sitting to supine position. Conclusion: The gravity effect resulting from postural change influences flow parameters suggesting thatfuture CFD studies should consider posture when conducting analyses. The implication of this study on postureholds importance in future studies of drug delivery though the nasal cavity. Keywords: CFD, posture, resistance, velocity, wall shear stress