Particulates Depositions in Patient-Specific Simulations of Respiratory System

Ambient particulates depositions have major impacts on respiratory functions. Patient-specific simulations of the respiratory system of a patient were performed to investigate the relationship between the flow characteristics and particulate depositions in the upper respiratory domain. CT scan images were imported to create a 3D model of the bronchial tree and then transferred to a computational fluid dynamics (CFD) software for simulation. Appropriate boundary conditions were assigned to simulate the sinusoidal behavior of the normal breathing cycle with the corresponding pressures at the outlets. Lagrangian phase model was used to simulate the micron solid round particulates transport and depositions. The simulations were performed for 2.5 micron and 10 micron particles. The implicit-unsteady Reynolds Averaged Navier-Stokes equations with K-ω turbulence model were used for these simulations. Results indicate high correlation between regions of high vortices, secondary flow and high wall shear stress and particulate depositions. The total deposition number for 10-micron particles was higher than that for the 2.5-micron particles. The differences in the locations of depositions at various generations of the lung illustrate the importance of the patient-specific simulations.Copyright © 2014 by ASME