Oura

The Oura Ring is a wearable sleep and recovery tracker designed as a lightweight titanium ring worn on the finger. Unlike wrist-based devices, the finger placement provides more stable access to pulse signals due to dense cap illary networks and reduced motion artifact. The ring continuously measures over 20 biosignals including heart rate, heart ra te variability (HRV), blood oxygen saturation (SpO2), respiratory rate, skin temperature deviation, and movement. Each mornin g, the Oura app delivers three core scores: a Sleep Score (0–100) based on total sleep time, efficiency, latency, and time sp ent in light, deep, and REM stages; a Readiness Score (0–100) aggregating sleep quality, HRV balance, resting heart rate tren d, body temperature deviation, and previous-day activity; and an Activity Score tracking steps, calories, and active minutes. HRV is measured at 5-minute intervals throughout the night, providing granular insight into autonomic nervous system balance. Body temperature deviation tracks changes from the user's personal baseline, useful for illness detection and cycle tracking. The ring syncs wirelessly with the Oura app via Bluetooth, and data is typically available by mid-morning after processing. U sers can access up to two years of historical data. The Oura Ring requires a membership subscription for full feature access and is available in multiple sizes and finishes.