Computational Fluid Dynamics Analysis on Overweight Sleep Apnea Patient Under Various Breathing Flow Patterns

Abstract

Obstructive Sleep Apnea (OSA) is a breathing disorder that occurs during sleep. This syndrome affects numerous people, especially those with abnormal body fat composition parameters such as body mass index (BMI) of more than 25 kg/m2 (overweight & obesity). OSA ensues when the tongue and soft palate muscles in a relaxed condition move towards gravity when the patient is in a supine position; this causes narrowing and blockage on the upper airway affecting breathing. There are several treatments for OSA, including upper airway surgery. A better understanding of airflow characteristics will assist ENT surgeons in identifying the blockage area. This paper examines airflow characteristics of the upper airway for overweight sleep apnea patients. The narrow and blockage area on the respiratory tract causes turbulence formation that is evaluated using Computational Fluid Dynamic (CFD) based on an actual parameter of the 3D model obtained by CT scan image result. Reynold’s averaged Navier-Stoke (RANS) equation and turbulent model, k-ω shear stress transport (SST), were applied. Airflow fluctuation was characterized by crucial parameters such as velocity, pressure, and turbulent kinetic energy (TKE). The result shows that the narrow cross-sectional area of the airway causes accretion of the velocity and pressure in the pharyngeal airway. The increasing airflow parameter results in high turbulent kinetic energy (TKE) that will determine the severity level of OSA patients. Investigating airflow characteristics in overweight OSA patients will help the medical practitioner validate the narrow and blockage area for the surgery.