Effect of Particle–Wall Interaction and Particle Shape on Particle Deposition Behavior in Human Respiratory System

Abstract

Dry powder inhalation (DPI) has attracted much attention as a treatment for respiratory diseases owing to the large effective absorption area in a human respiratory system. Understanding the drug particle motion in the respiratory system and the deposition behavior is necessary to improve the efficiency of DPI. We conducted computer simulations using a model coupling a discrete element method and a computational fluid dynamics method (DEM-CFD) to evaluate the particle deposition in human respiratory system. A simple artificial respiratory model was developed, which numerically investigated the effect of particle properties and inhalation patterns on the particle deposition behavior. The DEM-CFD simulations demonstrated that the smaller-and lower-density particles showed higher reachability into the simple respiratory model, and the particle arrival ratio to the deep region strongly depended on the aerodynamic diameter. The particle arrival ratio can be described as an exponential function of the aerodynamic diameter. Furthermore, the exponential relationship between the particle reachability into the depth of the simple respiratory model and the aerodynamic diameter predicted the particle aerodynamic diameter based on the required reachability. The particle shape also had an impact on the particle deposition behavior. The rod-like particles with a larger aspect ratio indicated higher reachability into the depth of the simple respiratory model. This was attributed to the high velocity motion of the particles whose long axis was in the direction of the deep region.

CFD-DEM Coupling Model for Deposition Process Analysis of Ultrafine Particles in a Micro Impinging Flow Field

“…Particle bounce is a major concern when using impactors [ 5 , 6 , 11 , 31 , 32 , 33 ]. The JKR model has been used to analyze the particle movement in the impactor [ 18 , 34 , 35 ]. In this paper, Hertz–Mindlin with JKR model was also selected for the contact force of particle-wall interactions [ 18 ].…”

“…The JKR model has been used to analyze the particle movement in the impactor [ 18 , 34 , 35 ]. In this paper, Hertz–Mindlin with JKR model was also selected for the contact force of particle-wall interactions [ 18 ]. In contrast to the Hertz–Mindlin model, the contact force in the normal direction F cn contains the damping force F dn and elastic force F JKR based on JKR theory.…”

“…CFD-DEM approach has been applied to simulate particle behavior in the impactor [ 17 ]. Ohsaki et al [ 18 ] simulated the behavior of fluid and particles in the cascade impactor using the CFD-DEM method with Johnson–Kendall–Roberts (JKR) theory [ 19 ]. They noted particles would reach the lower stages without considering adhesion force, indicating that both inertia and adhesion forces affect particle deposition.…”

Respirable Coal Mine Dust: A Review of Respiratory Deposition, Regulations, and Characterization

“…The deposition of medium-size particles (300 nanometers in diameter) is higher if not already deposited in the head region. Near 42% of small and about 2% of large particles are deposited in the alveolar region [43,[71][72][73]. A summary of lung deposition studies is presented in Table 1.…”

Numerical Study on Particle Adhesion in Dry Powder Inhaler Device

“…Tong et al studied the dispersion mechanism of agglomerated particles in an Aerolizer by a CFD-DEM coupled model. 26) In our previous study, a CFD-DEM coupled model was conducted to analyze the particle transportation in a human lung model. 27) However, very few studies on the particle behavior have been conducted on the device by using the CFD-DEM coupled model, as the amount of particle emissions from the device seriously affects the particle transport in the human lung.…”