Diagnostic Performance of a Combined Reflective Photoplethysmography and Ultra-Wideband Radar Device for Obstructive Sleep Apnea: Comparison with Polysomnography.

OBJECTIVE: Obstructive sleep apnea (OSA) exhibits high prevalence, yet limited polysomnography (PSG) resources highlight an urgent need for large scale screening. This study assessed the diagnostic efficacy of a combined reflective photoplethysmography and ultra-wideband radar device (Zhao-Guan wireless monitoring system, ZG-Sys) compared to PSG. The aims were to establish ZG-Sys OSA severity cutoff values and define its clinical implementation prospects. METHODS: This prospective, open-label diagnostic study was conducted in a sleep center, collecting 433 valid datasets for suspected sleep disorders from June 2023 to April 2024, via synchronous Type 1 PSG and ZG-Sys monitoring. ZG-Sys consists of a ring-style pulse oximeter (Circul) and an IR-UWB radar device (OrbSense). Statistical analysis utilized Spearman rank correlation, Bland-Altman analysis, and Receiver Operating Characteristic (ROC) curves to evaluate agreement and determine optimal ZG-AHI cutoff values against PSG-AHI standards (5, 15, and 30 events/h). RESULTS: ZG-AHI showed a significant correlation with PSG-AHI (Spearman r = 0.800, ICC = 0.908, P < 0.001). The optimal ZG-AHI cutoff for detecting moderate-to-severe OSA (PSG-AHI ≥15) was 20.8 events/h, yielding a high area under the curve (AUC) of 0.943. ZG-Sys demonstrated high sensitivity (89.10-90.80%) and specificity (85.30-88.80%) for identifying moderate-to-severe OSA. Although consistency was good across multiple sleep disorders (eg, parasomnias), weaker correlations were observed in the continuous positive airway pressure (CPAP) treatment group. CONCLUSION: ZG-Sys demonstrated moderate consistency with PSG across multiple sleep disorders, proving significant clinical value for screening and diagnosing moderate to severe OSA. Featuring simple charging, reusability, and real-time monitoring capabilities, ZG-Sys shows potential for clinical screening in sleep center settings.