Live capture: Bedtime ritual space
What we measure, how, and how we present it
Every number in a report states where it comes from and what it means.
Heart rate variability (HRV) and EEG
Heart rate variability (HRV)
The interval between one heartbeat and the next varies by a few milliseconds each time, and this variation is HRV. It is regulated by the autonomic nervous system and is often used to observe whether the body is in a tense or relaxed state. It is also affected by age, sex, posture, breathing, sleep, exercise and how you are that day, so comparing with yourself means more than comparing with other people.
| Heart rate | Beats per minute |
| RMSSD | Differences between successive beat-to-beat intervals; often used to observe regulation related to rest and recovery |
| SDNN | Overall variation of beat-to-beat intervals over a period |
| pNN50 | Share of successive intervals that differ by more than 50 milliseconds |
| Frequency-domain indicators | Strength of the different rhythmic components in heart rate variation |
EEG
With an EEG headband, the app records electrical activity of the brain at the scalp surface to follow changes in states such as focus and relaxation. EEG and HRV can be used on their own or with both devices together.
Signal cleaning
We clean the signal to recover what the body and mind are doing during relaxation. Abnormal beat-to-beat intervals caused by a loose fit or movement are removed first.
Three sampling windows
Every window is 5 minutes long. How the windows are chosen decides whether a report can be compared and explained.
| Symbol | Name | How it is taken | What it answers |
|---|---|---|---|
| ○ | Before | From 5 minutes before the start to as late as 10 minutes in; the cleanest 5 minutes in that 15-minute span | Your baseline today |
| ● | During the journey | From 10 minutes in to the end, in 5-minute windows; stretches with more than 8 seconds of unreliable data are dropped and the rest averaged. A 35-minute journey gives up to 5 windows | Your overall state once relaxation is under way |
| ★ | Best during the session | The best of the windows during the journey, with the time it occurred | Where in the journey you were most at ease |
How the windows are used
- ○ → ● is the change in a session.
- ★ marks your most comfortable stretch: shown on its own, not subtracted from before.
- Comparing ○ across sessions shows the long-term trend of your usual state.
Why the quiet wait comes first
People who know the routine relax very quickly. The quiet wait makes sure "before" captures your usual state; the change is calculated for everyone who completes the before measurement.
Our own measurement and windowing algorithms
Participants move, signals drop out now and then, and everyone settles at a different pace. The algorithms are built for this from the moment the data arrives.
- Data captureBeat-to-beat intervals and EEG from armbands, chest straps or headbands
- Short-gap repairBrief dropouts filled with methods accepted in the research literature, with partial correction for movement
- 15-minute baseline searchThe cleanest 5 minutes in a 15-minute span becomes "before"
- Exclusion rule for the averageStretches with more than 8 seconds of unreliable data are dropped; the rest uses standard 5-minute windows
- Best-window markerShows when in the journey the best window occurred
- Transparent data useEach report states the windows used and the valid seconds
Long gaps are dropped rather than guessed, so reports use only reliable data and stay comparable across sessions and people.
HRV and EEG six-axis radar
Each axis is a relative score from 0 to 100. It shows the direction of change.
| HRV six-axis radar | In general terms |
|---|---|
| Alertness | How awake and energetic you are |
| Regulation | Balance between tension and relaxation |
| Coherence | Synchrony between heart rhythm and breathing, which mostly appears when breathing slows down |
| Recovery | Regulation related to rest and recovery |
| Resilience | Reserve capacity for regulation |
| Sleep | How far the body has shifted into rest mode |
| EEG six-axis radar | In general terms |
|---|---|
| Thinking | State while thinking and processing information |
| Meditation | State during quiet, inward attention |
| Focus | State of concentrated attention |
| Restoration | State related to rest and recovery |
| Resilience | Flexibility in moving between states |
| Sleep | State close to rest or falling asleep |
Autonomic Age
Using reference norms, we convert several HRV indicators into an Autonomic Age: the age at which people of your sex typically show values like yours right now. An age is easier to grasp than milliseconds. Reports present it this way:
- It is given for both before and during the journey, so what you look at is the change.
- Your actual age appears only in your own report.
- The reference norms are updated over time.
Four stages in a session
Awake
An ordinary awake, active state
Settling
Slowing down
Stable relaxation
Reaching relaxation and staying there
Deep settling
Deeper than the first period of stable relaxation in the session; common as you get close to sleep
You can see how long it took to reach stable relaxation, how many minutes stable relaxation and deep settling each lasted, whether you settled directly or went back and forth, and any quick regulation episodes, where the body made a clear adjustment within a short time.
Data quality and presentation
- Devices: chest straps give the most stable data. Reports state how many seconds of valid data they used.
- Visible denominators: organization reports always show the number of people, the number of sessions and data coverage.
- Anonymization: organizations see anonymized group summaries only.
Statistical principles
- Group comparisons come with 95% confidence intervals and effect sizes, and a rule-based reading in plain language.
- The more groups you compare, the more likely a difference appears by chance, so the report warns you when there are more than four.
- Research institutions can use the anonymized research export, subject to research ethics review.
General background on HRV and EEG
Indicator definitions and measurement methods follow international standards and the methodological literature (Task Force, 1996; Shaffer & Ginsberg, 2017; Laborde et al., 2017). For the relationship between breathing and HRV, see (Lehrer & Gevirtz, 2014; Laborde et al., 2022). For the debate over LF/HF, see (Billman, 2013).
For more detail, read Heart rate variability (HRV) basics, EEG basics and our research review of 37 verified studies. To see how these figures appear in reports, open theReport templates.