Applying a Realistic Novel Ventilation Model Based on Spatial Expansion of Acini in a Stochastic Lung


1 Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran

2 Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran


In this paper, particle deposition in the upper airways and five lobes of human lung is simulated. The simulation isbased on a stochastic lung model, derived from detailed morphometric measurements. Pathways are simulated using Monte Carlo methods; consequently the wholestructure changes both stochastically and statistically in each simulation. Iin this investigation the termination phenomena is a function of each daughters’ diameter which best satisfies the lung’s morphometry. Complementary to the previous available assumptions, i.e., flow divisions according to the ratio of daughters’ cross sections or distal volumes, in this investigation flow rates are computed in an upward manner starting from the acini (where suction occurs), following to trachea. Regional expansion and contraction coefficients of acinar airways are taken into account in the airflow distribution analysis. Regional and total deposition fractions in the human respiratory system are computed by astochastic lung deposition model in a full breathing cycle. These fractions are computed in the upper airways as well as the above mentioned stochastic lung instead of a pre-defined lung structure. The effects of Brownian motion, inertial impaction and gravitational sedimentation are simulated in particle deposition analysis in respiratory airways using analytical equations.