Lung Sound Analysis and the Respiratory Cycle Dependence of Impulse Oscillometry in Asthma Patients

Objective A lung sound analysis (LSA) is useful for detecting airway inflammation and obstruction in patients with asthma. To elucidate the mechanism of LSA, we investigated the relationship between the exhalation-to-inhalation sound pressure ratio in the low frequency range between 100 and 195 Hz (E/I LF) and the respiratory cycle dependence of impulse oscillometry (IOS) parameters.