Numerical study of air flow in upper airway with obstructive sleep apnea syndrome using large eddy simulation

• Main Authors: Xiao-Wen Huang, 黃筱雯
• Other Authors: Ming-Jyh Chern
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/m2hnn2

碩士 === 國立臺灣科技大學 === 機械工程系 === 107 === Obstructive sleep apnea syndrome (OSAS) is a common disorder of adults, which is caused by repeated obstruction the upper airway during sleep. The effects of OSAS are not only the sleep quality but also the occurrence of disease such as hypertension, stroke and myocardial infarction. Apnea-hypopnoea index (AHI) is an acceptable measure for the severity of OSAS. Lots of treatments for patients with OSAS, it usually takes long time to adapt and inconveniently uses in life. Subsequently, many patients may give up the treatments because of adjustment disorder. Most of treatments are continuous positive airway pressure (CPAP) which is considered to be the standard treatments for patients with moderate-to-severe. Therefore, the patients who are more serious and unable to adapt will select surgical operations as their treatments for OSAS. In the present study, the preoperative, post-operative and after a period of time operation CT scan of upper airway by Maxillomandibular advancement (MMA) operation from patients are re-constructed and converted to in vitro three-dimensional models. The transitional/turbulent flow simulations during inspiration and expiration are studied using the Large Eddy Simulation (LES) technique in the in vitro 3D models of upper airway. Furthermore, the results show that the pressure drop, velocity, flow resistance, jet angle and stenosis of upper airway are significantly reduced after surgery and this model may be further applied for clinical evaluation in future.