Nasal Reconstruction and Mesh Generation
Computational modeling was used to generate the results. DICOM images of each subject were de-identified and imported into the imaging analysis and segmentation software, Avizo Lite 2019.3 (Thermo Fisher Scientific, Waltham, Massachusetts). Three-dimensional (3D) reconstructions of each subject’s main nasal passage were digitally created, and the paranasal sinuses excluded since this study focuses on the main nasal cavity. Avizo Lite 2019.3 was also used to calculate the volume (V) and surface area (SA) of each subject’s nasal passage. The nasopharynx was excluded from these calculations as it has been reported that perception of nasal patency during respiration was more evident from nostrils to choana than nostrils to posterior end of nasopharynx.16 The surface area-to-volume ratio (SAV) was calculated by dividing the SA by the V.
Reconstructed models were exported in stereolithography format from Avizo and into the CAD and mesh generating software package, ICEM-CFD 19.0 (ANSYS, Canonsburg, PA). Planar inlet surfaces near the nostrils and an outlet surface at the nasopharynx were created. Next, roughly 4 million unstructured tetrahedral elements and three-layer prism elements were generated in each model’s computational domain. Mesh refinement analysis was not done based on prior work based on prior work by our group.17 Mesh quality analysis was performed to confirm the aspect ratio for the hybrid mesh was properly smoothed to prevent poor elements quality from impacting the accuracy of the numerical simulation.