Inhalation Induced Stresses and Flow Characteristics in Human Airways through Fluid‐Structure Interaction Analysis

Abstract

Better understanding of stresses and flow characteristics in the human airways is very important for many clinical applications such as aerosol drug therapy, inhalation toxicology, and airway remodeling process. The bifurcation geometry of airway generations 3 to 5 based on the ICRP tracheobronchial model was chosen to analyze the flow characteristics and stresses during inhalation. A computational model was developed to investigate the airway tissue flexibility effect on stresses and flow characteristics in the airways. The finite-element method with the fluid-structure interaction analysis was employed to investigate the transient responses of the flow characteristics and stresses in the airways during inhalation. The simulation results showed that tissue flexibility affected the maximum airflow velocity, airway pressure, and wall shear stress about 2%, 7%, and 6%, respectively. The simulation results also showed that the differences between the orthotropic and isotropic material models on the airway stresses were in the ranges of 25–52%. The results from the present study suggest that it is very important to incorporate the orthotropic tissue properties into a computational model for studying flow characteristics and stresses in the airways.

Wall shear stress distributions in a model of normal and constricted small airways

“…13,14 However, more experimental work on accurate values for Young's modulus of airway wall types is needed.…”

Deformable image registration of heterogeneous human lung incorporating the bronchial tree

“…Different values of modulus of elasticity of the airway have been reported in the literature including 0.01, 0.12, 16,18 0.13, 22 and 5.8 MPa. 23 Experimental studies on the bronchial trees that relate the wall thickness to diameter 23 and pressure-diameter relationship 25 of human airways have shown a value of modulus of elasticity within the proximity of 0.12 MPa at a transpulmonary pressure of 20 cmH 2 O.…”

“…However, in order to minimize the local deformation differences experienced by few nodes, a realistic value of modulus of elasticity of the bronchial tree is needed. Although a large range of modulus of elasticity values are investigated in this study ͑0.01-18 MPa͒, the most reported value for the bronchial tree is within the proximity of 0.12 MPa, 16,18,22,24,25 while the highest value of 18 is reported for the tracheal rings.…”

Computational fluid-dynamics optimization of a human tracheal endoprosthesis

“…2-2). Finally, as performed in other studies [17][18][19], the movement of the solid mesh of the trachea was restrained by fixing its top and bottom surfaces.…”

“…However, these do not take the airway deformation into account and are focused on providing detailed information of the flow features in each pulmonar branch. More recently, fluid solid interaction studies performed for tracheal geometries tube and single or multiple bifurcations can be found in literature [16][17][18][19][20][21][22].…”