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Coupling of lung tissue tethering force to fluid dynamics in the pulmonary circulation
Author(s) -
Burrowes K. S.,
Tawhai M. H.
Publication year - 2010
Publication title -
international journal for numerical methods in biomedical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.741
H-Index - 63
eISSN - 2040-7947
pISSN - 2040-7939
DOI - 10.1002/cnm.1386
Subject(s) - mechanics , blood flow , lung , lung volumes , pressure gradient , anatomy , materials science , chemistry , physics , medicine , cardiology
Abstract Dynamic changes in lung volume during breathing and alteration of posture are both known to influence the distribution of perfusion within the lung. Here we couple computational models of pulmonary blood flow and parenchymal tissue mechanics to produce a novel flow model that predicts tissue deformation simultaneously with flow distributions at different lung volumes and postures. The model is used to study the effect of lung volume on flow distribution as a result of normal variation in axial and radial tethering forces. Finite deformation elasticity is used to predict volume changes of the lung tissue and resultant tethering pressures within the tissue. A finite element model of the pulmonary arterial network is embedded within the lung volume and deforms with the tissue. The spatial distribution of steady‐state blood flow is predicted using the Poiseuille resistance (including gravity), conservation of mass, and a vascular pressure–radius relationship. Blood flow gradients with respect to gravitationally dependent height are calculated. Gradients are predicted to be consistently steeper in the supine (compared with prone) model due to increased tissue deformation. Decreased lung volume resulted in increased gravitationally dependent flow gradients, predominantly due to the effect of axial vessel stretch on the length and the radius of the arterial vessels. Copyright © 2010 John Wiley & Sons, Ltd.