Optimizing cervical breath sound acquisition protocol in dysphagia patients: an orthogonal experimental study

BACKGROUND: Dysphagia is a highly prevalent condition among patients with stroke. Cervical auscultation serves as a crucial screening method for dysphagia detection. The advancement of artificial intelligence has enabled acoustic analysis to emerge as a viable alternative to manual auscultation. While high-quality breath sound recordings are fundamental for reliable acoustic analysis in dysphagia screening, current clinical practice lacks standardized protocols for acquiring cervical respiratory sounds during auscultation. OBJECTIVE: To investigate the optimal acquisition protocol for cervical breath sounds in dysphagia patients after stroke using orthogonal experimental design. METHOD: ) orthogonal array. Cervical breath sound data were systematically acquired from 298 dysphagia patients across nine protocol variations. Acoustic signal processing quantified three parameters: signal-to-noise ratio (SNR), aggregate entropy, and average power. The optimal configuration (A1B1C3) achieved maximum SNR (37.35 dB), maximum average power (78.79 dB), and minimum aggregate entropy (1.51 bits). CONCLUSIONS: The optimal acquisition protocol involves positioning the stethoscope on the lateral trachea immediately below the cricoid cartilage, maintaining direct skin contact without interposing dressing materials, and secured with medical-grade pressure-sensitive tape. These evidence-based specifications offer technical guidance and standardized procedures for clinical implementation of cervical auscultation in the assessment of dysphagia after stroke.