A poroelastic model coupled to a fluid network with applications in lung modelling

Abstract

Here we develop a lung ventilation model, based a continuum poroelastic representation of lung parenchyma and a 0D airway tree flow model. For the poroelastic approximation we design and implement a lowest order stabilised finite element method. This component is strongly coupled to the 0D airway tree model. The framework is applied to a realistic lung anatomical model derived from computed tomography data and an artificially generated airway tree to model the conducting airway region. Numerical simulations produce physiologically realistic solutions, and demonstrate the effect of airway constriction and reduced tissue elasticity on ventilation, tissue stress and alveolar pressure distribution. The key advantage of the model is the ability to provide insight into the mutual dependence between ventilation and deformation. This is essential when studying lung diseases, such as chronic obstructive pulmonary disease and pulmonary fibrosis. Thus the model can be used to form a better understanding of integrated lung mechanics in both the healthy and diseased states.

Predicted airway obstruction distribution based on dynamical lung ventilation data: A coupled modeling‐machine learning methodology

“…First we assume a linear elastic behavior of the lung parenchyma, which is likely to be valid for low tidal breathing frequency and displacement regimes. Although there is no consensus on which constitutive relation shall be considered [42], [43], [44], the actual parenchyma law is much more complex. The identification problem approach proposed in this paper works assuming mechanical properties are known, which is not the case in practice, here representative values from the literature were assumed.…”

A tree‐parenchyma coupled model for lung ventilation simulation

“…In this work, we treat the parenchyma as an elastic media coupled, in the same spirit as Berger et al, to a space‐filling dyadic resistive tree. In this study, the tree is coupled to a poroelastic media through applied pressures and volume preservations constraints. Here, we consider a linear elastic media.…”

A stabilized finite element method for finite-strain three-field poroelasticity

“…Biological examples include the coupling of flow in coronary vessels with the mechanical deformation of myocardial tissue to create a poroelastic model of coronary perfusion [13,15]. Other examples include modelling tissue deformation and the ventilation in the lungs [6], protein-based hydrogels embedded within cells [22], brain oedema and hydrocephalus [39,56], microcirculation of blood and interstitial fluid in the liver lobule [36], and interstitial fluid and tissue in articular cartilage and intervertebral discs [21,24,42].…”