Wearable Devices for Obstructive Sleep Apnea: Evidence, Clinical Utility, and Future Directions

Obstructive sleep apnea (OSA) is common, underdiagnosed, and associated with substantial cardiometabolic and neurocognitive morbidity.Polysomnography (PSG) remains the diagnostic reference standard, yet access and cost constraints impede timely evaluation for many patients.In this narrative review, we synthesize the contemporary evidence on wearable and near-wearable technologies relevant to OSA, including peripheral arterial tonometry (PAT) finger devices, mandibular movement (MM) sensors, photoplethysmography (PPG)-based rings and wrist wearables, under-mattress ballistocardiography (BCG) mats, contactless radar, and smartphone audio approaches.We discuss their physiological signal models, validation against PSG, performance across phenotypes, methodological limitations, and roles in clinical pathways.Peripheral arterial tonometry-based devices show moderate-to-strong agreement with PSG at the population level but can misclassify severity in individual patients.Mandibular movement sensors and under-mattress BCG demonstrate promising accuracy for detecting moderate-to-severe OSA.Photoplethysmography rings and smartwatches are improving but remain heterogeneous across brands, sensors, and algorithms.Contactless radar and smartphone acoustics are emerging modalities with encouraging early data, yet limited large-scale clinical validation.Current guidelines emphasize PSG or technically adequate home sleep apnea testing (HSAT) for diagnosis in appropriately selected adults, while cautioning against unaudited use of consumer sleep technology.Future work should prioritize standardized validation against contemporary scoring rules, multinight protocols, algorithm transparency, and diverse cohorts to ensure generalisability.Until then, wearables should be deployed thoughtfully for screening, triage, adjunctive monitoring, and-where supported by evidence and regulatory clearance-as components of HSAT pathways.