AORA
Aora
Blog · April 2026

The instruments,
the protocol,
the literature.

Aora sits at the intersection of three things: the clinical protocols used to study rumination and negative affect, a piece of invisible behind-the-ear hardware that can run those measurements outside a lab, and a fast-moving research field showing that EEG in a wearable form factor is now viable. What follows is how those pieces fit together.

Reading time · 8 min4 entriesUpdated Apr 2026
01Protocol
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How rumination is actually induced in a clinical EEG study.

Every session opens with a calibration baseline — one to three minutes of resting EEG, always. From there, negative mood is induced through a deliberately layered sequence: a brief autobiographical recall of a sad event, prompts surfacing unresolved personal goals, and then the rumination-elicitation task itself.

Participants generate four events from their own life — one sad, one frustrating, one failure, one hurtful — and rate each on a nine-point scale. A mean above five is the standard threshold for successful induction. Follow-up prompts then push the participant into metacognition: what your feelings mean, why you reacted the way you did. The session typically closes with Velten-style negative self-statements.

This is the ground truth Aora's cognitive assessments are calibrated against. If our signal can't track what this protocol reliably produces, nothing else we build on top of it matters.

Standardized across clinical rumination-induction research

“If our signal can't track what this protocol reliably produces, nothing else we build on top of it matters.”

— Aora method notes
02Hardware
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What AORA Nano actually measures.

AORA Nano is a behind-the-ear wearable that continuously and invisibly monitors your cognitive state — a Holter-class cardiac monitor, a pulse oximeter, and a basic neural interface compressed into a sleek ear hook you forget you're wearing.

Behind-the-ear stack · 4 layers
Cardiac
Single-lead ECG · IEC 60601-2-47

Dry electrodes on the mastoid bone capture clinical-grade ECG for 24/7 detection of atrial fibrillation, premature ventricular contractions, and other arrhythmias — no patches, no cables.

PPG & pulse oximetry
MAX86176 · SFH7016 / SFH2701

The behind-the-ear site is one of the best locations on the body for optical sensing: stable skin contact, minimal motion artifacts, excellent perfusion. Delivers HR, SpO2, and HRV continuously.

EEG potential
>1 GΩ input impedance · 0.6 µVRMS noise floor

Not a full clinical EEG, but sufficient to read basic cerebral biopotentials — attention level, drowsiness, stress signatures. The beginning of a consumer-grade neural interface.

Connectivity & power
nRF54L15 · BLE 5.4 · 256 Mbit flash · wireless charging

Real-time streaming to a phone, days of offline buffer on the W25Q256, and LTC4126-10 wireless charging. Fully sealed — shower, rain, sport. No exposed connectors.

The use cases fall out of the sensor stack: an AFib patient wearing Nano instead of a Holter, an athlete tracking HRV through training without a chest strap, a long-haul pilot or truck driver being warned before they fall asleep, an elderly person monitored continuously without ever feeling like a patient.

04Clinical instruments
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Built on instruments your neurologist already uses.

Aora's self-report assessments are adapted from the Copenhagen Burnout Inventory1, the Perceived Stress Scale2, and peer-reviewed cognitive-load research — the same tools used in studies at Stanford and Mass General.

Layered on top, the wearable combines HRV, sleep architecture, and Apple Health signals against the Nature Medicine (2025) framework for smartwatch-based cognitive assessment3.

Assessment

Measure the organ you haven't measured yet.

References
  1. [1]

    Copenhagen Burnout Inventory — Kristensen, T. S., Borritz, M., Villadsen, E., & Christensen, K. B. (2005). Work & Stress, 19(3), 192–207.

  2. [2]

    Perceived Stress Scale — Cohen, S., Kamarck, T., & Mermelstein, R. (1983). Journal of Health and Social Behavior, 24(4), 385–396.

  3. [3]

    Smartwatch-based cognitive assessment framework — Nature Medicine, 2025.