A wearable ring oximeter for detection of sleep disordered breathing

Wearable devices have been developed that can continuously monitor physiologic variables. One device, Circul® (Bodimetrics Corp, Los Angeles, CA), with a form factor of a ring, measures several variables (SpO2, movement, heart rate).

To evaluate the potential utility of this device in detecting sleep breathing disorders.

OSA severity measured by the oxygen desaturation Index (ODI) using a wearable oximetric Circul® ring (ODI as defined by 3 % desaturation - cODI3 %) was compared with the gold standard, polysomnography (PSG) in patients suspected of having sleep-disordered breathing. The Circul data was autoscored by the device's software; a technician scored the PSG data. The sensitivity (S), and specificity (E) for the different thresholds for cODI3 % compared to the PSG AHI and PSG ODI, were calculated.

164 patients (age = 44.8 years + 12.3 (SD)) were enrolled. Using the PSG-derived AHI as the reference for classification, the best cut-off points were: OSA = AHI ≥ 5: cODI3 % ≥ 4.3 (S 87.8 %, E 93.8 %); OSA = AHI ≥ 15: cODI3 % ≥ 13.1 (S 76 %, E 100 %); OSA = AHI ≥ 30 = : cODI3 % ≥ 16.2 (S 85.7 %, E 92 %); Using the ODI from the PSG as the reference for classification, the respective cut-off points were: OSA=ODI ≥ 5: cODI3 % ≥ 4.3 (S 93.4 %, E 88.9 %); OSA=ODI ≥ 15:cODI3 % ≥ 13.1 (S85.2 %, E98.4 %); OSA=ODI ≥ 30: cODI3 % ≥ 18.7 (S 98.4 %, E 92.2 %).

Circul® oximetry demonstrated good diagnostic accuracy compared to the gold standard in determining OSA severity. cODI3 % greater than 13 suggests that significant OSA might be present.