Airflow dynamic and particle deposition in age-specific human lungs

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.