Document Detail


Measurement, reconstruction, and flow-field computation of the human pharynx with application to sleep apnea.
MedLine Citation:
PMID:  20550980     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Repetitive closure of the upper airway characterizes obstructive sleep apnea. It disrupts sleep causing excessive daytime drowsiness and is linked to hypertension and cardiovascular disease. Previous studies simulating the underlying fluid mechanics are based upon geometries, time-averaged over the respiratory cycle, obtained usually via MRI or CT scans. Here, we generate an anatomically correct geometry from data captured in vivo by an endoscopic optical technique. This allows quantitative real-time imaging of the internal cross section with minimal invasiveness. The steady inhalation flow field is computed using a k-ω shear-stress transport (SST) turbulence model. Simulations reveal flow mechanisms that produce low-pressure regions on the sidewalls of the pharynx and on the soft palate within the pharyngeal section of minimum area. Soft-palate displacement and side-wall deformations further reduce the pressures in these regions, thus creating forces that would tend to narrow the airway. These phenomena suggest a mechanism for airway closure in the lateral direction as clinically observed. Correlations between pressure and airway deformation indicate that quantitative prediction of the low-pressure regions for an individual are possible. The present predictions warrant and can guide clinical investigation to confirm the phenomenology and its quantification, while the overall approach represents an advancement toward patient-specific modeling.
Authors:
A D Lucey; A J C King; G A Tetlow; J Wang; J J Armstrong; M S Leigh; A Paduch; J H Walsh; D D Sampson; P R Eastwood; D R Hillman
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-06-14
Journal Detail:
Title:  IEEE transactions on bio-medical engineering     Volume:  57     ISSN:  1558-2531     ISO Abbreviation:  IEEE Trans Biomed Eng     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-09-20     Completed Date:  2011-01-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0012737     Medline TA:  IEEE Trans Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2535-48     Citation Subset:  IM    
Affiliation:
Fluid Dynamics Research Group, Curtin University, Perth, WA 6845, Australia. a.lucey@curtin.edu.au
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MeSH Terms
Descriptor/Qualifier:
Endoscopy / instrumentation
Humans
Image Processing, Computer-Assisted / methods*
Models, Biological*
Palate, Soft / anatomy & histology
Pharynx / anatomy & histology*,  physiopathology
Sleep Apnea Syndromes / etiology*,  physiopathology
Tomography, Optical Coherence / instrumentation,  methods

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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