Computational analysis of airflow dynamics for predicting collapsible sites in the upper airways: A preliminary study

Ji Sung Na, Hwi Dong Jung, Hyung Ju Cho, Yoon Jeong Choi, Joon Sang Lee

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The present study aimed to detail the relationship between the flow and structure characteristics of the upper airways and airway collapsibility in obstructive sleep apnea. Using a computational approach, we performed simulations of the flow and structure of the upper airways in two patients having different facial morphologies: retruding and protruding jaws, respectively. First, transient flow simulation was performed using a prescribed volume flow rate to observe flow characteristics within upper airways with an unsteady effect. In the retruding jaw, the maximum magnitude of velocity and pressure drop with velocity shear and vortical motion was observed at the oropharyngeal level. In contrast, in the protruding jaw, the overall magnitude of velocity and pressure was relatively small. To identify the cause of the pressure drop in the retruding jaw, pressure gradient components induced by flow were examined. Ofnote, vortical motion was highly associated with pressure drop. Structure simulation was performed to observe the deformation and collapsibility of soft tissue around the upper airways using the surface pressure obtained from the flow sim ulation. At peak flow rate, the soft tissue of the retruding jaw was highly expanded, and a collapse was observed at the oropharyngeal and epiglottis levels. NEW & NOTEWORTHY Aerodynamic characteristics have been reported to correlate with airway occlusion. However, a detailed mechanism of the phenomenon within the upper airways and its impact on airway collapsibility remain poorly understood. This study provides in silico results for aerodynamic characteristics, such as vortical structure, pressure drop, and exact location of the obstruction using a computational approach. Large deformation of soft tissue was observed in the retruding jaw, suggesting that it is responsible for obstructive sleep apnea.

Original languageEnglish
Pages (from-to)330-340
Number of pages11
JournalJournal of Applied Physiology
Volume126
Issue number2
DOIs
Publication statusPublished - 2019 Feb

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Jaw
Pressure
Obstructive Sleep Apnea
Epiglottis
Computer Simulation

All Science Journal Classification (ASJC) codes

  • Physiology
  • Physiology (medical)

Cite this

Na, Ji Sung ; Jung, Hwi Dong ; Cho, Hyung Ju ; Choi, Yoon Jeong ; Lee, Joon Sang. / Computational analysis of airflow dynamics for predicting collapsible sites in the upper airways : A preliminary study. In: Journal of Applied Physiology. 2019 ; Vol. 126, No. 2. pp. 330-340.
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Computational analysis of airflow dynamics for predicting collapsible sites in the upper airways : A preliminary study. / Na, Ji Sung; Jung, Hwi Dong; Cho, Hyung Ju; Choi, Yoon Jeong; Lee, Joon Sang.

In: Journal of Applied Physiology, Vol. 126, No. 2, 02.2019, p. 330-340.

Research output: Contribution to journalArticle

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