Journal article
Inflation instability in the lung: an analytical model of a thick-walled alveolus with wavy fibres under large deformations
Journal of the Royal Society interface, Vol.18(183), pp.20210594-20210594
10/2021
DOI: 10.1098/rsif.2021.0594
PMCID: PMC8510704
PMID: 34637644
Abstract
Inflation of hollow elastic structures can become unstable and exhibit a runaway phenomenon if the tension in their walls does not rise rapidly enough with increasing volume. Biological systems avoid such inflation instability for reasons that remain poorly understood. This is best exemplified by the lung, which inflates over its functional volume range without instability. The goal of this study was to determine how the constituents of lung parenchyma determine tissue stresses that protect alveoli from instability-related overdistension during inflation. We present an analytical model of a thick-walled alveolus composed of wavy elastic fibres, and investigate its pressure-volume behaviour under large deformations. Using second-harmonic generation imaging, we found that collagen waviness follows a beta distribution. Using this distribution to fit human pressure-volume curves, we estimated collagen and elastin effective stiffnesses to be 1247 kPa and 18.3 kPa, respectively. Furthermore, we demonstrate that linearly elastic but wavy collagen fibres are sufficient to achieve inflation stability within the physiological pressure range if the alveolar thickness-to-radius ratio is greater than 0.05. Our model thus identifies the constraints on alveolar geometry and collagen waviness required for inflation stability and provides a multiscale link between alveolar pressure and stresses on fibres in healthy and diseased lungs.
Details
- Title: Subtitle
- Inflation instability in the lung: an analytical model of a thick-walled alveolus with wavy fibres under large deformations
- Creators
- Samer Bou Jawde - Boston UniversityKavon Karrobi - Boston UniversityDarren Roblyer - Boston UniversityFrancesco Vicario - Philips Research, Cambridge, MA, USAJacob Herrmann - Boston UniversityDylan Casey - University of VermontKenneth R Lutchen - Boston UniversityDimitrije Stamenović - Boston UniversityJason H T Bates - University of VermontBéla Suki - Boston University
- Resource Type
- Journal article
- Publication Details
- Journal of the Royal Society interface, Vol.18(183), pp.20210594-20210594
- DOI
- 10.1098/rsif.2021.0594
- PMID
- 34637644
- PMCID
- PMC8510704
- ISSN
- 1742-5689
- eISSN
- 1742-5662
- Grant note
- T32 HL076122 / NHLBI NIH HHS U01 HL139466 / NHLBI NIH HHS
- Language
- English
- Date published
- 10/2021
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering
- Record Identifier
- 9984306834502771
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