Quantifying parenchymal tethering in a finite element simulation of a human lung slice under bronchoconstriction.
Airway hyper-responsiveness (AHR), a hallmark of asthma, is a highly complex phenomenon characterised by multiple processes manifesting over a large range of length and time scales. Multiscale computational models have been derived to embody the experimental understanding of AHR. While current models differ in their derivation, a common assumption is that the increase in parenchymal tethering pressure P(teth) during airway constriction can be described using the model proposed by Lai-Fook (1979), which is based on intact lung experimental data for elastic moduli over a range of inflation pressures. Here we reexamine this relationship for consistency with a nonlinear elastic material law that has been parameterised to the pressure-volume behaviour of the intact lung. We show that the nonlinear law and Lai-Fook's relationship are consistent for small constrictions, but diverge when the constriction becomes large.
Auckland Bioengineering Institute, University of Auckland, Private Bag 92019 Auckland Mail Centre, Auckland 1142, New Zealand. b.breen@auckland.ac.nz
Barbara J
BJ
Breen
Graham M
GM
Donovan
James
J
Sneyd
Merryn H
MH
Tawhai
D001249:Asthma / Q000503:physiopathology; D016084:Bronchoconstriction / Q000502:physiology*; D003198:Computer Simulation; D004548:Elasticity / Q000502:physiology; D020342:Finite Element Analysis; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008954:Models, Biological