Exploration of Respiratory Sound Analysis and Diagnostic Model Development for Tracheomalacia Using a Rabbit Tracheomalacia Model

Airway stenosis can be caused by a variety of conditions. In children, these include laryngomalacia of the upper airway, tracheal stenosis of the lower airway, and tracheomalacia. Our ultimate goal is to develop a diagnostic technique for tracheomalacia by analysing respiratory sounds as biomarkers. In this study, we will create a rabbit model of stenosis of the lower airway and construct an experimental system that will serve as a basis for analysing respiratory sounds. We developed an experimental system to analyze and compare the acoustic characteristics of respiratory sounds from normal and tracheomalacia models. In the recording of respiratory sounds with a stethoscope, we confirmed that simultaneous recording of auscultatory sounds and endotracheal pressure is effective because endotracheal pressure significantly affects the frequency characteristics of respiratory sounds. Although this was a limited analysis with a limited to specific individual, differences in various acoustic features of normal respiratory sounds and those of the tracheomalacia model were observed. The respiratory sound analysis may provide valuable insights for the assessment of symptoms associated with tracheomalacia.