ATS-1 Plane Methods: Sleep, HRV, WHO-5 and Sampling

The requirements

ATS-1 plane method requirements
Item	Requirement
Sleep	Primary: duration, onset, offset, midpoint, regularity. Sleep stages should be flagged low-confidence.
HRV	Nightly lnRMSSD. Daytime spot HRV must not enter indices.
Provenance	Every record must carry device model, firmware, algorithm version and timezone.
Schema	Plane I exports must map to IEEE 1752.1-2021. P1752.2 must not be cited as a standard.
Energy expenditure	Reported with a ±20% band; never shown as precise.
Light	Wrist light is a photopic proxy only.
WHO-5	Every 14 days; score = raw score (0–25) × 4, giving 0–100; no cut-offs shown.
Experience sampling	Signal-contingent, semi-random prompts: 6 a day in a 12-hour window, 20-minute expiry, at least 6 days per burst.
Compliance	Target at least 80%. Participants below 33% are excluded from index computation and reported.
Biomarkers	A count of markers in the reference population's top quartile; the reference population must be named; research construct only; no individual clinical return.

Why nightly HRV

Spot HRV readings taken during the day change with posture, movement and breathing. Nightly lnRMSSD, the natural log of a standard short-term HRV measure, is steadier from night to night. See HRV and recovery explained.

Why a standard schema

Mapping Plane I data to IEEE 1752.1-2021 means sleep and activity records from different devices can be read the same way. Together with provenance on every record, that is what makes data comparable across products and studies.

Why WHO-5

The WHO-5 Well-Being Index is short, free to use and widely studied (WHO-5 overview (CORC)). ATS-1 shows its score without cut-offs, because cut-offs are for screening, which is outside ATS-1's scope.

Questions

Can we use our own questionnaire instead of WHO-5?

WHO-5 is the anchor scale. Other scales are optional and must respect their own licenses; some commercial scales require a paid license.

Sources

Keep reading

Data readiness checkerFree self-check for wearable and digital-health teams: tick what you collect and see which ATS-1 items you report having.Conformance levelsThe three ATS-1 conformance levels (data, model, endpoint-checked), the claim template, closed and open protocols, and why "validated" is banned.HRV and recovery explainedWhat heart-rate variability is, why nightly lnRMSSD against your own 28-day baseline beats daytime spot readings, and how recovery speed is measured.State IndexThe ATS-1 State Index: robust z-scores of HRV, sleep and affect against a 28-day personal baseline, using the median and MAD.

Take the next step.

How ATS-1 collects each plane: nightly lnRMSSD, sleep timing, provenance, IEEE 1752.1 mapping, WHO-5 every 14 days and sampling rules.

Check your readiness Get the textbook

Plane methods