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.