Simulation of Flow in the Human Upper Airways Modeled as a Piping System Using the Hydraulic Diameter

Obstructive sleep apnea (OSA) is a medical condition characterized by repetitive obstructions in the human upper airways during sleep. Recent estimates from United States show that impacts 15% to 20% of adult population. OSA treatment can be subdivided into surgical and non-surgical approaches. Non-surgical approaches such as continuous positive airway pressure (CPAP) devices have highest success rates when used correctly. However, these low patient compliance due invasive nature sleep, leaving surgery viable alternative for many. Predicting outcome difficult complex both surgeries themselves. CFD modeling helpful way gain valuable insights flow structures impact individual on airways. not approach each patient-specific case its time-consuming nature. A pragmatic model has been created predict basis produce valid fast non-CFD engineers. The transforms piping system applying hydraulic diameter equation geometries CT scans. This paper aims validate use given Dh = 4 · (A / Pe), where cross-sectional area Pe wetted perimeter, nasal cavity provide novel cavity. proposed CDh Pe) coefficient. Airflow simulated through simplified geometry using find an updated equation. Pragmatic simulations compared results assess model’s accuracy. showed original did give entirely accurate 3.71 gave better accuracy validation cases. Tuning parameter patient’s airways, succeeded quite accurately reproducing area-averaged