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An Implicit Elastic Theory for Lung Parenchyma
Alan D Freed1, Daniel R Einstein
1Department of Mechanical Engineering, Saginaw Valley State University, 202 Pioneer Hall, 7400 Bay Road, University Center, MI 48710, USA.
International Journal of Engineering Science
|November 13, 2012
Summary
This study introduces a new thermodynamic model for lung tissue elasticity, improving computational models of respiration. The novel approach enhances accuracy in predicting airflow and aerosol transport within the lungs.
Area of Science:
- Biomechanics
- Computational Biology
- Thermodynamics
Background:
- Lung airways and parenchyma undergo significant deformation during respiration.
- Accurate modeling of airflow and aerosol transport necessitates fluid-structure interaction (FSI) simulations.
- Existing constitutive models for lung parenchyma lack the required accuracy and efficiency for FSI.
Purpose of the Study:
- To develop an accurate and efficient constitutive model for lung parenchyma within a fluid-structure interaction framework.
- To derive an implicit theory of elasticity from thermodynamics for soft biological tissues.
- To propose a novel definition of Lagrangian strain rate suitable for computational modeling.
Main Methods:
- Derivation of an implicit theory of elasticity from thermodynamic principles.
- Development of a generic strain-energy template analogous to the Fung model.
- Proposal and mathematical justification of a novel, separable Lagrangian strain rate definition.
- Construction and characterization of a new material model for lung parenchyma nonlinearity.
Main Results:
- A novel, thermodynamically consistent implicit elastic theory for lung parenchyma.
- A generic strain-energy function template applicable to soft tissues.
- A new Lagrangian strain rate definition separable into volumetric and deviatoric components.
- A characterized material model demonstrating accurate prediction of lung parenchyma's elastic response.
Conclusions:
- The developed thermodynamic framework and novel strain rate definition provide a robust foundation for accurate FSI modeling of respiration.
- The new constitutive model enhances the efficiency and accuracy of predicting lung biomechanics.
- This work offers a significant advancement in computational modeling of lung airflow and aerosol transport.
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