A Computational Study of Respiratory Biomechanics in Idealized Healthy and Stenosed Subsegmental Bronchi Section of Infant, Child and Adult Airways

A. J. Oyejide, E.Emmanuel, A.A.Awonusi, E. O. Ige

Abstract: The subsegmental bronchi play crucial role in airflow transition from the conducting to the respiratory zones of the lungs, due to their unique location on the bronchial tree. However, pathophysiological conditions, such as chronic bronchitis, could affect these airways, leading to stenosis, a condition that narrows the airway diameter. Thus, it is essential to understand the fundamental hydrodynamics in this subsegment, especially for stenotic cases. In this study, we investigated airflow characteristics in idealized airway geometries of 6-month-old infant, 5-year-old child and 25 years old adult, for both healthy and 80% stenosed conditions. Generation-six to nine (G6-G9) were considered to cover for about half the entire length of the subsegmental generations (G5-G16), with constrictions placed at G6 and G9. Physiological inspiratory and expiratory airflow rates were simulated in models of all three age groups using Computational Fluid Dynamics (CFD) and variables such as velocities, wall pressure and wall shear stress were obtained. In the healthy airways used as control, we realised that peak flow dynamics reduces as age increase. In the stenosed geometries for all age groups, the infant’s respiratory performance was most severely affected during the entire respiration, with the emergence of turbulence in the sixth generation considered to be implicating health scenario.

Series on Biomechanics, Vol.36 No.4 (2022), 25-45
DOI:10.7546/SB.04.04.2022

Keywords: adult airway; child airway; computational fluid dynamics; Infant Airway; respiratory flow; stenosis

Date published: 2022-11-07