Biomedical and biophysical limits to mathematical modeling of pulmonary system mechanics: a scoping review on aerosol and drug delivery

Undoubtedly, the construction of the biomechanical geometry systems with the help of computer tomography (CT) and magnetic resonance imaging (MRI) has made a significant advancement in studying in vitro numerical models as accurately as possible. However, some simplifying assumptions in the computational studies of the respiratory system have caused errors and deviations from the in vivo actual state. The most important of these hypotheses is how to generate volume from the point cloud exported from CT or MRI images, not paying attention to the wall thickness and its effect in computational fluid dynamic method, statistical logic of aerosol trap in software; and most importantly, the viscoelastic effect of respiratory tract wall in living tissue pointed in the fluid–structure interaction method. So that applying the viscoelastic dynamic mesh effect in the form of the moving deforming mesh can be very effective in achieving more appropriate response quality. Also, changing the volume fraction of the pulmonary extracellular matrix constituents leads to changes in elastic modulus (storage modulus) and the viscous modulus (loss modulus) of lung tissue. Therefore, in the biomedical computational methods where the model wall is considered flexible, the viscoelastic properties of the texture must be considered correctly.