# Shape Matters: Computational Fluid Dynamics Analysis of Epiglottis Shape Influence on Airway Collapse in Obstructive Sleep Apnea Patients

## TL;DR

This study uses computational fluid dynamics to show that the shape of the epiglottis affects airway collapse in obstructive sleep apnea patients.

## Contribution

The novel contribution is demonstrating how epiglottis shape influences aerodynamic forces and airway collapse using patient-specific and simplified models.

## Key findings

- Flat-shaped epiglottises experience higher aerodynamic loads at lower flow rates, increasing collapse risk.
- Findings from simplified models were confirmed using patient-specific 3D airway simulations.
- Epiglottis morphology is shown to significantly impact upper airway dynamics in obstructive sleep apnea.

## Abstract

Background: The study investigates the influence of epiglottis morphology on airflow dynamics and mechanical loading using computational fluid dynamics (CFD) in patients with obstructive sleep apnea (OSA), where the epiglottis may contribute to upper airway obstructions during sleep. Methods: A two-stage analysis was conducted: first, using a simplified airway model with two distinct epiglottis shapes (flat and curved), and second, using patient-specific 3D airway geometries derived from computed tomography (CT) scans. The simplified model enabled isolated analysis of flow-related aerodynamic forces and torques acting on the epiglottis across varying flow rates and inclination angles. Results: Results showed that the flat-shaped epiglottis was subjected to higher aerodynamic loads, particularly at lower flow rates, indicating increased susceptibility to collapse. These findings were corroborated by simulations on patient-specific 3D airway models. Conclusions: The study confirms that epiglottis morphology plays a critical role in the pathogenesis of OSA and underscores the potential of CFD for personalized assessment and treatment planning.