Airflow simulation through a dynamic subject-specific model of the central airways

Past studies utilised Computational Fluid Dynamics (CFD) to analyse the airflow and the particle deposition within realistic models of the central airways constructed from Computed Tomography (CT) data. However, as the material properties of the airway wall and of its surrounding tissues are largely unknown, investigations were limited to static/rigid models of the central airways, whilst central airways are compliant in nature. In this paper, a new algorithm is proposed for deforming the airway CFD mesh between two volumetric positions to allow the simulation of the full breathing cycle. The deformation algorithm was validated against available Magnetic Resonance Imaging (MRI) lung volume change measurements and showed good agreement. It was found that the wall motion has a significant effect on the airflow pattern and distribution with respect to the rigid wall model.