Research protocol for the diagnostic accuracy of intelligent portable impulse oscillometry across different respiratory diseases: a multicentre, cross-sectional study

Introduction: Early clinical manifestations of chronic respiratory diseases are often non-specific, and substantial symptom overlap exists among different diseases, making early differential diagnosis challenging. Conventional spirometry requires a high degree of patient cooperation, which limits its applicability in primary care settings and special populations. Impulse oscillometry (IOS) reflects respiratory mechanical characteristics during tidal breathing and offers several advantages, including convenience, non-invasiveness and low dependence on patient cooperation. This study aims to develop a multi-disease intelligent diagnostic model based on a portable IOS device and to systematically evaluate its diagnostic performance across different respiratory diseases.