When you woke up

Name: When you woke up
Creator: Ultrahuman

Checked against an FDA-cleared home sleep test and a validated smartwatch

OPTICALMOTION

Accuracy

93%

Wake Time Agreement

of nights within half an hour, against a validated smartwatch worn on the same nights

Reference standard

Validated smartwatch

Sample size

56 participants

The Ultrahuman Ring places the moment you woke a typical 8.0 minutes from an FDA-cleared home sleep test reading brain activity, and a validated smartwatch agrees.

8.0 mintypical night-to-night error, against the home sleep test

7.9 minaverage per-night difference, against a validated smartwatch

93%of nights within half an hour, against the smartwatch

+3.6 minthe ring calls waking late, on average

The end of the night is rarely a single moment. Most people surface, drift back under, and surface again before they are properly up, which leaves a stretch of minutes that is neither clearly asleep nor clearly awake. Placing one timestamp inside that stretch is what the Ultrahuman Ring and its reference are both being asked to do.

Against that home sleep test — a home sleep study rather than a laboratory polysomnogram — the typical night-to-night error is 8.0 minutes, across 20 paired nights from 4 people. Against a validated smartwatch, on the algorithm shipping today, 93% of nights fall inside half an hour, with an average per-night difference of 7.9 minutes across 106 nights from 56 people.

These are per-night figures rather than an average across nights.

What difference remains runs in one consistent direction: the Ultrahuman Ring places waking about three and a half minutes late against the home sleep test, with a validated smartwatch showing the same pattern. A steady offset moves every night by the same amount and leaves the shape of your week unchanged.

The detail

Measured against an FDA-cleared home sleep test that records single-channel EEG at the forehead — a home sleep study rather than a laboratory polysomnogram — and, separately, against a validated smartwatch worn on the same nights.

Sensor: Optical pulse sensor (PPG, photoplethysmography), Accelerometer (motion sensor)
Measured against: Validated smartwatch
What the figure counts: Nights within 30 minutes
How agreement is defined: the share of nights on which the ring lands inside half an hour of the reference
Participants: 56 participants (106 paired nights)

How Does the Sleep Regularity Questionnaire Relate to Wearable- and Diary-Derived Sleep Regularity?

Journal of Circadian Rhythms 24(1):2 · 2026 · Supplementary Table 1, the ring against an FDA-cleared home sleep test recording single-channel EEG — a home sleep study, not a laboratory polysomnogram — across 20 paired nights from 4 people; the 8.0 minutes is the typical error that table reports. The 93% comes from Ultrahuman’s own sleep-timing benchmark: the ring against a validated smartwatch worn the same nights, share of nights inside half an hour, 106 paired nights from 56 people, 2026.

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When you woke up