DRAWING 01 / 05
Ring 4 — Assembly
Sheet A — Plan + Section
Filed · Oulu, 67°N · 2026
Live telemetry — finger 4R · subject 0001
Materials · Gr-5 Ti · 4N sapphire · DLC

Your body has been
telling you everything.
Ōura listens.

Bill of materials10 / 14
  • 01Photoplethysmography arrayPPG×3
  • 02NTC thermistor, distal±0.01°
  • 03Capillary spectrometer525nm
  • 04Triaxial inertial cluster3-axis
  • 05Vagal-tone resonator8 kHz
  • 06NFC induction stator13.56 MHz
  • 07Lithium-polymer cell22 mAh
  • 08Sapphire optical window4N
  • 09Titanium-DLC substrateGr-5
  • 10Skin conductance bridge2 µS
One ring. Fifty signals. Each captured at the millisecond and read into a single quiet voice — the one that tells you when to push, when to rest, and when something is changing.
IMU·3 SECT A–A 01 02 03 04 05 06 07 08 ⌀ 22.0 ⌀ 18.4 inner · size 9 7.9 0 5 10 mm VIEW: AXONOMETRIC · ISO 30° SCALE 4:1 — DRAWING NOT TO ACTUAL SIZE
Spec / Ring 4REV 04
  • mMass, finished2.2 g
  • hProfile height2.45 mm
  • wInner width7.9 mm
  • fSample rate, PPG250 Hz
  • fSample rate, IMU100 Hz
  • tBody-temp resolution0.01 °C
  • bBattery, typical8 days
  • bRecharge to 100%80 min
  • iIngress rating10 ATM
  • σBiosignals derived50+
Built in Oulu, 67° north. The same town for fifteen years, the same engineers, the same obsession with the night. Read by physicians, validated by peer review, worn by half a million people who'd rather know.
TRACE 24H · CH1 HR · CH2 HRV · CH3 SKIN-T LIVE · TX 58 BPM · 62 ms · 32.4°C
ProjectŌura · Ring 4
Drawing01 of 05
Scale4 : 1
SheetA — Assembly
DrawnJ. Korpinen
Filed2026-04-12
Rev04
Folio67°02′ N
DRAWING 02 / 05
Nocturnal Trace · Subject 0001
Sheet B — Hypnogram + HR
Chapter 01 · Sleep

The first place
healing happens.

Every stage of last night, mapped to the minute.

REM where it should be. Deep where it shouldn't be cut short. Heart rate falling at the right hour. Body temperature finding its trough at 4:13 AM — the moment the immune system does its quietest, most important work.

This is not a graph for staring at. It is a graph for sleeping easier the next night.

Total · in bed8h 12m
Efficiency94%
Sleep score87
Body temp · Δ baseline−0.32 °C
Resting HR · min42 BPM
HRV · avg62 ms
SCOPE · CH1 HYPNOGRAM · CH2 HR · SWEEP 8h12m NIGHT OF 2026-04-11
AWAKE REM LIGHT DEEP HR · 42–68 BPM
ProjectŌura · Ring 4
Drawing02 of 05
SeriesSleep · 84 nights
SheetB — Hypnogram
DrawnA. Pesonen
Filed2026-04-12
Rev02
Window23:14–07:26
DRAWING 03 / 05
Readiness Index
Sheet C — Dial + 28-day Plate
Chapter 02 · Recovery

A readiness score
that reads you.

HRV, body temperature, respiratory rate, prior strain.

Woven into a single number that tells you whether today is for pushing or for softness. Eight weeks of mornings stamped to the right — the run of greens that means a body finding its rhythm, and the one Tuesday in red that means a body asking for a quieter day.

Today · readiness87
28-day · avg82
HRV · trend Δ+9 ms
Resp rate14.2 / min
Strain · yesterdayModerate
87
READY
+5 vs 28d
READINESS · 28 DAY PLATE M T W T F S S
LOW
PEAK
ProjectŌura · Ring 4
Drawing03 of 05
Window28 days
SheetC — Readiness
DrawnR. Lehto
Filed2026-04-12
Rev01
IndexR/28
DRAWING 04 / 05
Circadian Polar · 28 d
Sheet D — Wheel
Chapter 03 · Rhythm

Cycles, not
spikes.

Your body keeps time — circadian, hormonal, seasonal.

Ōura draws the curves you can't feel, the ones that decide how Tuesday goes. For women, an unmatched cycle map. For everyone, the rest of you — the body temperature that climbs in the second half of a month, the resting heart rate that wanders with the light.

Cycle · current28 d
Phase · todayDay 14 · Ovulatory
BBT · today36.7 °C
BBT · Δ baseline+0.34 °C
Confidence98%
Drawing 04 D · Sub. 0001
28 days · clockwise
0° = day 1
BBT · 36.3 → 36.95 °C
Filed 2026-04-12
Rev 03
ProjectŌura · Ring 4
Drawing04 of 05
Span28 days
SheetD — Polar
DrawnM. Niemi
Filed2026-04-12
Rev03
IndexP/28
DRAWING 05 / 05
Cardio Trajectory · age 30–70
Sheet E — Projection
Chapter 04 · Longevity

Don't just live longer.
Live longer awake.

Cardio age. Metabolic age. The slow numbers.

The dashed line is the population. The red line is you — seven years younger by cardio age, and pulling away. Each ring on the chart is a year. Each year is a chance to bend the curve back up.

Cardio age34 yr
Δ chrono−7 yr
VO₂ max · today47 ml/kg/min
Pop. percentile92nd
Projection · age 7031 ml/kg/min
VO₂ MAX · 40 YR PROJECTIONELLIOT · M · 41
Population mean Subject 0001 — observed + projected
ProjectŌura · Ring 4
Drawing05 of 05
Window40 years
SheetE — Trajectory
DrawnP. Salo
Filed2026-04-12
Rev02
CohortM · 40–45
SHEET F · personalization · NIGHT 1

Made for you.
Drawn for your life.

— DRAWING ASSIGNED, REV 01 · 2026 —

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Ōura · Member CARD 04 / 38
Listen
longer.
Member since
2026 · Apr
Ring
4 · Ti · Sz 9
Lab
Oulu · 67°N
Issue
Rev 04
SUBJECT 0001 VALID THRU 09 / 28