Detection of apnea and hypopnea events using a wireless Abdomen-Worn sensor with SpO₂ integration

PURPOSE: Polysomnography is the gold standard for diagnosing sleep apnea (SA), but it is costly and not widely available. Home sleep apnea testing (HSAT) offers a more accessible, lower-cost alternative. Type III HSAT typically uses nasal pressure sensors, respiratory inductance plethysmography (RIP) belts, and pulse oximetry; however, nasal sensors and RIP belts may be uncomfortable or unsuitable for some patients. This study assessed whether apnea and hypopnea events can be detected using a wireless abdomen-worn sensor (Soomirang) combined with SpO₂ monitoring, eliminating the need for nasal pressure sensors or RIP belts. METHODS: Data from 37 participants were collected using the Soomirang device and a typical type III HSAT (AL). Two models were developed for apnea and hypopnea event detection: SoomOxy, combining abdominal and body movement data with SpO₂, and Soom, using abdominal and body movement data alone. Their performance was evaluated against AL. RESULTS: SoomOxy demonstrated strong agreement with AL, achieving an area under the curve of 0.9447 for apnea and 0.8702 for hypopnea detection, a predicted apnea hypopnea index correlation of 0.96, and an average accuracy of 0.8286 across all severity categories. The SoomOxy outperformed Soom model in detecting hypopnea events. CONCLUSION: A wireless abdomen-worn sensor combined with SpO₂ monitoring can accurately detect and classify apnea and hypopnea events without nasal pressure and RIP belts, offering a practical and more comfortable alternative to conventional HSAT setups.