On intra- and intersubject variabilities of airflow in the human lungs

AUTOR(ES)

Choi, Jiwoong

FONTE

American Institute of Physics

RESUMO

The effects of intra- and intersubject variabilities in airway geometry on airflow in the human lungs are investigated by large eddy simulation. The airway models of two human subjects consisting of extra- and intrathoracic airways are reconstructed from CT images. For intrasubject study, airflows at two inspiratory flow rates are simulated on the airway geometries of the same subject with four different levels of truncation. These airway models are the original complete geometry and three geometries obtained by truncating the original one at the subglottis, the supraglottis, and the laryngopharynx, respectively. A comparison of the airflows in the complete geometry model shows that the characteristics of the turbulent laryngeal jet in the trachea are similar regardless of Reynolds number in terms of mean velocities, turbulence statistics, coherent structures, and pressure distribution. The truncated airway models, however, do not produce the similar flow structures observed in the complete geometry. An improved inlet boundary condition is then proposed for the airway model truncated at the laryngopharynx to improve the accuracy of solution. The new boundary condition significantly improves the mean flow. The spectral analysis shows that turbulent characteristics are captured downstream away from the glottis. For intersubject study, although the overall flow characteristics are similar, two morphological factors are found to significantly affect the flows between subjects. These are the constriction ratio of the glottis with respect to the trachea and the curvature and shape of the airways.

Documentos Relacionados

• Intra- and Interlaboratory Variabilities of Results Obtained with the Quantiplex Human Immunodeficiency Virus Type 1 RNA bDNA Assay, Version 3.0
• Intra- and Interindividual Variabilities of Valacyclovir Oral Bioavailability and Effect of Coadministration of an hPEPT1 Inhibitor
• Application of intra- and extracellular sugars and dimethylsulfoxide to human oocyte cryopreservation
• Effect of changes in intra- and extracellular sodium on the inward (anomalous) rectification in salamander photoreceptors.
• Influence of intra- and extrauterine factors on infant sleep in the first 6 months of life