MECHANICS OF LUNG MICROSTRUCTURE AS A BASIS FOR LUNG MECHANICS, AND MULTISCALE-MULTIPHYSICS MODEL OF LUNG MECHANICS, AIRFLOW, BLOOD FLOW, AND DIFFUSION
Miloš Kojić, Ivo Vlastelica, Boban Stojanovic, Vladimir Ranković, Akira Tsuda (DOI: 10.24874/jsscm.2025.19.01.12)
Abstract
This paper contains two parts – the first is related to the mechanics of lung microstructure, and the second is a formulation of a multiscale-multiphysics model of the lung. The second part considers the entire lung that relies on the mechanics of the microstructure and recently developed a multiscale composite finite element of the lung tissue (MSCL). The MSCL is further extended to include airflow, blood flow, and mass transport by diffusion, as a General Lung Finite Element (GLFE). The microstructural mechanics relies on the generally accepted Wilson-Bachofen model of balance between internal and external forces of the lung supporting system. Besides the stresses in the tissue, the effects of the surfactant play an important role in the alveolated microstructural system, vital for lung functioning. Our microstructural model demonstrates a geometric hysteresis within a duct. The multiscale-multiphysics model for airflow and blood flow is based on our smeared concept (Kojic Transport Model, KTM) where the subdomains within our Composite Smeared Finite Element (CSFE) represent the airway generations; and capillary, extracellular space and cells for blood flow and mass transport by blood. This computational methodology is built into our finite element code PAK.
