Airflow dynamic and particle deposition in age-specific human lungs

Abstract

Particle transportation and deposition (TD) during inhalation drug delivery in human lungs is affected by lung anatomy, breathing pattern, as well as particles properties. The lung volume and breathing capacity reduce as age increases. It is found that diameters of lung airways reduce by about 10% after every 10-years for over 50-year age people. However, the studies on the particle TD in age-specific human lungs are still very limited in the literature. Therefore, it is important to understand the effects of aging on targeted drug particle deposition. In this study, numerical simulations are conducted to investigate the particle TD in human lungs for people of 50 to 80-year ages. The ANSYS FLUENT solver based on the finite volume discretization method is used for numerical calculations. The variation of inhalation rates and lung diameters with age is considered. The results show that the deposition efficiency of old age people is higher than that of young age people. Moreover, the majority of the particles are deposited in the first bifurcation area of lungs of the 50-80 year ages at generation G9-G13.

Aerosol Particle Transport and Deposition in Upper and Lower Airways of Infant, Child and Adult Human Lungs

“…Table 2 lists the flow parameters used in this study. The velocity inlet and pressure outlet boundary conditions are considered at the lung model's inlet and outlet, respectively [29][30][31][32][33]. The airway wall was considered to be stationary, and a non-slip boundary condition is used on the wall surface [34][35][36].…”

“…In the simulations, 64,400 spherical particles with a uniform diameter and a density of 1100 kg/m 3 were injected randomly at the inlet surface at one time [36,39]. A 'trap' boundary condition is considered in the lung airways wall, and an escape condition is considered at all outputs for particle deposition [28,40]. Due to the trap situation, the coefficient of restitution is zero.…”

The Bulk Density and Cohesion of Submicron Particles Emitted by a Residential Boiler When Burning Solid Fuels

“…Another reason to pay attention to particle density is that density affects the deposition of particles in the human respiratory tract; thus, it is essential to determine their impact on human health. It was found that particles with a higher density have a higher settling velocity than particles with a lower density [8]. The movement of smoke plumes in an atmosphere is determined by the atmospheric conditions, particle size, and particle density.…”