Morphological characteristics of the upper airway and pressure drop analysis using 3D CFD in OSA patients.
10.4041/kjod.2010.40.2.66
- Author:
Sung Seo MO
1
;
Hyung Taek AHN
;
Jeong Seon LEE
;
Yoo Sam CHUNG
;
Yoon Shik MOON
;
Eung Kwon PAE
;
Sang Jin SUNG
Author Information
1. Division of Orthodontics, Department of Dentistry, College of Medicine, The Catholic University of Korea, St. Mary's Hospital, Korea.
- Publication Type:Original Article
- Keywords:
OSA;
Upper airway;
Computational fluid dynamics;
Pressure drop
- MeSH:
Airway Obstruction;
Airway Resistance;
Humans;
Hydrodynamics;
Oropharynx;
Recurrence;
Sleep Apnea, Obstructive;
Tidal Volume
- From:Korean Journal of Orthodontics
2010;40(2):66-76
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: Obstructive sleep apnea (OSA) is a common disorder which is characterized by a recurrence of entire or partial collapse of the pharyngeal airway during sleep. A given tidal volume must traverse the soft tissue tube structure of the upper airway, so the tendency for airway obstruction is influenced by the geometries of the duct and characteristics of the airflow in respect to fluid dynamics. METHODS: Individualized 3D FEA models were reconstructed from pretreatment computerized tomogram images of three patients with obstructive sleep apnea. 3D computational fluid dynamics analysis was used to observe the effect of airway geometry on the flow velocity, negative pressure and pressure drop in the upper airway at an inspiration flow rate of 170, 200, and 230 ml/s per nostril. RESULTS: In all 3 models, large airflow velocity and negative pressure were observed around the section of minimum area (SMA), the region which narrows around the velopharynx and oropharynx. The bigger the Out-A (outlet area)/ SMA-A (SMA area) ratio, the greater was the change in airflow velocity and negative pressure. CONCLUSIONS: Pressure drop meaning the difference between highest pressure at nostril and lowest pressure at SMA, is a good indicator for upper airway resistance which increased more as the airflow volume was increased.
