Sleep stages, HRV, and overnight SpO2
Oura Ring 5
The current Oura generation. Exports the account ZIP and Trends CSV CPAP Clarity reads, with overnight SpO2, body-temperature, and respiratory-rate sensors.
Compare on AmazonOura Ring · Gen 2 · Gen 3 · Gen 4
CPAP Clarity reads your Oura account export and shows sleep stages, HRV, resting heart rate, body temperature, and SpO2 alongside your CPAP nights. Browser-only import. Nothing leaves your device.
Short answer: no. The Oura Ring is a wellness device. It does not measure airflow, it does not measure respiratory effort, and it is not cleared by the FDA to diagnose obstructive sleep apnea. Oura itself states the ring is not intended to diagnose, treat, cure, monitor, or prevent medical conditions.
What the ring can flag, with caveats: elevated resting heart rate and suppressed HRV across consecutive nights, fragmented sleep stages, and on Gen 3 and Gen 4, drops in overnight SpO2. None of those numbers prove apnea on their own. They are starting points for a conversation, not a verdict.
If you suspect sleep apnea, the right next step is a validated screening questionnaire and a clinical evaluation. Both are linked below.
Oura derives a per-30-second stage timeline from movement, heart rate, and HRV patterns. CPAP Clarity rolls these into percentages for the night and a full stepped timeline next to your CPAP session.
Oura averages HRV across the resting window. Lower HRV often tracks with autonomic stress, illness onset, or fragmented sleep, even on nights your AHI looks clean.
Resting HR is one of the most stable wellness signals on the ring. A multi-night drift above your personal baseline can flag stress, illness, or sleep debt before you feel it.
Oura compares the night's skin temperature against your personal baseline rather than a population norm. A persistent deviation is one of Oura's illness and recovery signals.
Gen 3 and Gen 4 rings record overnight SpO2 using red and infrared LEDs at the base of the finger. Gen 2 rings do not have this sensor. CPAP Clarity charts the average and overlays it on the same night as your CPAP AHI.
Oura's daily readiness combines HRV, RHR, sleep, temperature, and activity into a single number. Useful as a high-level signal alongside the underlying metrics it summarizes.
The Oura account export contains every night the ring has logged. CPAP Clarity imports the entire archive in one ZIP, so you can see multi-year patterns alongside your CPAP history.
Every Oura night is joined by calendar date to your CPAP session. The dashboard shows AHI, leak, and usage hours next to sleep stages, HRV, and SpO2 for the same date.
| Feature | Oura Ring | Apple Watch | Home Sleep Study |
|---|---|---|---|
| Sleep stage estimate | Yes: Movement + heart rate + HRV | Yes: Movement + heart rate | Yes: Clinical EEG, AASM scored |
| Heart rate variability | Yes: Overnight average, nightly | Yes: Overnight average, nightly | Partial: Not the primary metric |
| Blood oxygen (SpO2) | Partial: Gen 3 and Gen 4 only | Partial: Series 6 and later | Yes: Continuous, medical-grade |
| Body temperature | Yes: Baseline deviation | Partial: Series 8 and later, wrist temp | No: Not standard |
| Daily wear comfort | Yes: Ring, lightweight | Partial: Wrist, larger | No: One night only, in lab or at home |
| FDA cleared to diagnose apnea | No: No | No: Notification feature only | Yes: Standard of care |
A 2025 systematic review (Khan et al., OTO Open) pooled six Oura validation studies covering 388 participants and found no statistically significant differences between the ring and polysomnography on total sleep time, sleep efficiency, and REM sleep. The same review still concludes the ring cannot replace clinical diagnostic testing.
you want to track sleep architecture, HRV, and recovery trends over months. You are already on CPAP and want autonomic context alongside your AHI. You prefer minimal hardware on your body overnight.
you already wear one daily. You want Apple's sleep apnea notification feature (Series 9 and later). You value fitness, daytime heart rate, and sleep in a single device.
you suspect untreated sleep apnea and need a diagnosis. Your symptoms are not explained by your current therapy. Your physician needs medical-grade evidence for a treatment decision.
Representative example. Numbers below are illustrative, not a real user's data.
In a representative night, the CPAP side might show AHI 1.4 across 6 hours and 12 minutes of use, median leak around 4 L/min, and an AutoSet algorithm running 8.2 to 11.8 cmH₂O. The Oura side of the same night might report 14 percent deep sleep, 19 percent REM, 56 percent light, 11 percent awake, overnight HRV of 38 milliseconds against a 42 millisecond personal baseline, resting heart rate of 58, average SpO2 of 96 percent, and a readiness score of 78.
What the two together tell you in this example: the CPAP is clearly preventing scored events, AHI well under 5. But deep sleep is compressed below the typical 13 to 23 percent range. The HRV dip from baseline is mild but real. Average SpO2 is normal; the ring does not flag a desaturation problem here.
None of those numbers prove anything on their own. Together they make for a more concrete conversation with your sleep physician than "AHI 1.4, looks fine." A persistent multi-week pattern of compressed deep sleep, even on clean-AHI nights, is the kind of signal worth asking about. A single night by itself is not.
The Oura Ring 5 is the current generation. It keeps the overnight SpO2, body-temperature, and respiratory-rate sensors CPAP Clarity reads from the export.
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Sleep stages, HRV, and overnight SpO2
The current Oura generation. Exports the account ZIP and Trends CSV CPAP Clarity reads, with overnight SpO2, body-temperature, and respiratory-rate sensors.
Compare on AmazonOpen ouraring.com in a browser, sign in, go to Membership Hub, then Account, then Privacy, then Download your data. Oura sends a download link by email.
Oura prepares the export on their side; delivery varies from minutes to several days, since Oura treats it as an occasional full archive. For a faster refresh of recent nights, the Trends page on cloud.ouraring.com (Gen 3 / Ring 4 with membership) offers an instant Download Data CSV with Period set to Daily; CPAP Clarity imports that too, minus sleep stages, SpO2, and stress.
Drop the ZIP (or the Trends CSV) onto the dashboard import zone. The whole parse runs in your browser. Nothing leaves your device.
No. The Oura Ring is a wellness tracker, not a diagnostic device. Oura's own product policy states the ring is not intended to diagnose, treat, cure, monitor, or prevent medical conditions. If you suspect sleep apnea, take a validated screening questionnaire such as STOP-BANG or the Epworth Sleepiness Scale, then talk to a sleep physician about a home sleep test or in-lab polysomnography.
Your CPAP machine sees the airway. It counts apneas and hypopneas, measures pressure, and logs leak. It cannot tell you whether your heart rate variability recovered overnight, whether you cycled through enough deep sleep and REM, or whether your body temperature is trending in a way that often precedes illness. The Oura Ring measures those autonomic and architecture signals. Side by side, the two streams answer different questions.
No. CPAP Clarity reads the Oura ZIP on its own. You can import Oura data without any CPAP data and view your sleep stages, HRV, RHR, body temperature, and SpO2 at /oura. The dashboard does light up additional cross-night context when both streams are present, but the Oura side of the site works standalone.
Generation 3 and Generation 4 give you the richest dataset because they include the red and infrared LEDs needed for overnight SpO2. Gen 2 rings can still export and import every other metric (sleep stages, HRV, RHR, body temperature, readiness), but the SpO2 column will be empty since the sensor was added in Gen 3.
No. The Oura ZIP is parsed entirely in your browser. CPAP Clarity does not upload your Oura data to any server. Your sleep stages, HRV, and SpO2 are stored only in your browser's local IndexedDB, on the device you imported from. Clearing your browser data, or using the data hub at /data, removes them.
A sleep study (polysomnography or a Type III home sleep test) scores sleep stages from EEG signals using clinical AASM criteria, and it directly measures airflow, respiratory effort, and oxygen saturation with medical-grade sensors. The Oura Ring estimates stages from movement and pulse patterns instead. A 2024 validation study (Altini et al., Sleep Medicine) reported about 91.7 percent agreement on sleep vs wake, with 4-stage staging accuracy ranging from 75.5 percent (light sleep) to 90.6 percent (REM). Good for trends, not a substitute for a study when apnea is the question.