Feasibility of the Belun sleep platform for obstructive sleep apnea diagnosis: A pilot case series from India

Polysomnography (PSG) is the gold standard for diagnosing obstructive sleep apnea (OSA), but it poses significant barriers in resource-limited settings. The Belun Ring, a new home sleep apnea testing device utilising photoplethysmography and deep learning analysis, offers an alternative approach for diagnosing OSA. Herein, we present our initial experience with this device. Simultaneous in-lab PSG and Belun Ring assessments were conducted in six consecutive adults with suspected OSA undergoing PSG. Diagnostic performance was assessed by comparing the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) derived from both modalities. Belun Ring demonstrated a strong correlation with PSG AHI and ODI (Pearson's r = 0.98 for both; P < 0.001), but misclassified OSA severity in 50% of cases, mainly underestimating moderate disease. The device had a sensitivity of 83% for diagnosing OSA. This case series demonstrates the feasibility of Belun Ring use in an Indian population, but frequent severity misclassification is a concern, limiting its diagnostic applicability.