Agreement Between Sleep and Respiratory Measures From a Wearable Oximetry Ring and Simultaneous Complete Polysomnography
Bibliographic record
Abstract
Abstract Rationale: Wearable technology offers the potential for low-cost, accessible monitoring for sleep disorders. However, data validating the accuracy of measurements is often limited or non-existent, limiting clinical utility. The Circul+ ring (BodiMetrics, Inc) incorporates a reflectance oximeter and accelerometer which yield measures of sleep-wake state and oxygenation via proprietary software. Limited data validating the oximetry measurements, but no data on the sleep-wake analysis, have been published. Our aim was to evaluate the accuracy of Circul+ sleep-wake and oximetry data compared with simultaneously recorded in-laboratory complete polysomnography (PSG). Methods: We studied 15 patients (6 males) of mean (± SD) age 50.4±15.2, BMI 34.4±8.6 undergoing PSG for obstructive sleep apnea (OSA). Prior to lights out, the ring was installed, with bluetooth connection to a bedside tablet running Circul+ acquisition/analysis application (version 1.0.163). PSG (Nihon-Kohden PSG 1100, Polysmith version 10) was scored manually using AASM v3.0 (1A hypopnea) criteria. Epoch-by-epoch matched comparisons of sleep-wake staging were made between Circul+ vs PSG data. Stages N1 and N2 from PSG were combined for comparison to Circul+ “Light sleep”. Values for 3% Oxygen Desaturation Index (ODI3) and ODI4, mean SpO2, nadir SpO2, and time below 90% saturation (T90%) were also compared. Results: Concordance between PSG and Circul+ sleep-wake staging is shown in the Table. Circul+ achieved only modest accuracy across sleep-wake stages compared to PSG. Notably, there was only 44% concordance for PSG wakefulness and a greater proportion of PSG REM epochs were identified as Light Sleep rather than REM by Circul+. Median AHI from PSG was 29.0 [12.5-37.9] events/h. There were no significant differences (Mann-Whitney U) between PSG and Circul+ for ODI3 (median [IQR] PSG = 9.1/h [3.0-32.6], Circul 13.7/h [5.3-32.5], p=0.87), ODI4 (PSG 4.0/h [1.1-22.1], Circul 9.8/h [2.2-18.2], p=0.80), Nadir SpO2 (p=0.76), or T90% (p=0.77). However, mean SpO2 was significantly lower for PSG (94.0%[93.0-95.0%]) than Circul+ (96.2%[95.4-97.8%]), p=0.004. Spearman correlations for Circul+ vs PSG oximetry measures were moderate to strong. Bland-Altman analysis for ODI3 revealed a mean PSG-Circul+ difference of 0.2/h (+/-1.96 SD: 41.0, -40.7) and for ODI4 2.7/h (35.3, -30.0). Conclusion: The version of the Circul+ ring/software evaluated in this study does not provide reliable sleep-wake staging. Conceivably, modifications to signal acquisition and/or processing by the manufacturer could improve this, but this remains to be demonstrated. The findings for Circul+ oximetry measures suggest this device could prove useful in OSA screening and assessment of treatment responses.Supported by: MUHC Foundation and RI-MUHC
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.003 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".