Upper Airway Dynamic Characteristics-Comparative Study Between Healthy Subjects and OSA Patients

The human upper airway (UA) dynamic characteristics differ from healthy subjects to obstructive sleep apnea (OSA) patients. Having a common term of reference for comparison is very difficult as many anatomical parameters are involved; namely: volume of airway, uvula, tongue, and air gaps at the rear of the mouth. This study investigates these characteristics for healthy and OSA subjects and proposes new common ground parameters for comparison. The objective of this study is to identify the causes of collapse by comparing these characteristics between those subjects. Magnetic resonance imaging (MRI) data of the UA expanding from nasopharynx to the hypopharynx were conducted on 8 healthy subjects and 10 OSA patients. 3D models were constructed and simulated. Measurements of the UA were evaluated and compared in both groups. The outcomes support the fact that the air volume is not the main contributor for the UA collapse and show that the apneic events are caused by the large size of the tongue and uvula. Finally, the natural frequencies for the uvula and tongue were very close in both participating groups.Copyright © 2015 by ASME