Examination of the behaviour of the lungs under high-frequency chest compression airway clearance therapy

Abstract

Chronic Obstructive Pulmonary Disease (COPD) is the third leading cause of death worldwide, with 3 million in 2019. Medical devices for high-frequency chest compression (HFCC) therapy are currently the most common approach to relieve COPD symptoms in the lungs. The resonance frequency of the human thorax is one of the most influential parameters for HFCC to act on the viscoelastic, shearthinning, and thixotropic properties of bronchial mucus for airway clearance therapy (ACT). In this study, a 3D computed tomography-based finite element analysis (CT/FEA) is done by COMSOL Multiphysics ® 6.1 under the frequency domain with the purpose of examining the resonance frequency and the behaviour of lungs under HFCC therapy. An excitation under 140 dBSPL with a frequency range between 5 and 100 Hz is considered on the back-chest surface. As for comparison, the maximum kinetic energy density is 3.3 times higher than the kinetic energy density for the whole thorax because of the poroviscoelastic physical properties of the lungs. The lung kinetic energy density value reaches a peak at 56 µJ/m 3 at 30 Hz, which is supported by the numerical and experimental studies in the literature.