Orexin System
Contact
A research instrument

Continuous orexin activity. Without a needle.

The first wearable system that estimates orexin (hypocretin) neuron activity in real time, by fusing pupillometry with autonomic, thermal, and respiratory biomarkers across three coordinated body-worn devices.

16
Autonomic signals ↓
3
Body-worn devices ↓
1
Continuous index ↓
16 autonomic signals from 3 body locations
Glasses — face + ear
Pupil diameter +
Mean pupil diameter in millimeters under controlled 940nm IR illumination. The strongest single non-invasive proxy for orexin neuron activity. Causally validated by Grujic et al. (Nature Neuroscience, 2023) via the orexin → locus coeruleus → noradrenaline → pupil dilation pathway.
Pupillary unrest index +
Variance of pupil diameter over 10–30 second windows. When orexin is unstable, the pupil oscillates rhythmically even in constant light — called pupillary hippus. This oscillation is a direct marker of autonomic instability and often appears 5–10 minutes before a subjective drowsiness episode.
Blink rate +
Number of blinks per minute, detected from pupil disappearance in the IR camera stream. Blink rate increases as orexin-driven alertness decreases. Narcolepsy Type 1 patients show characteristically elevated blink rates during waking hours.
Blink duration +
Mean duration of each blink in milliseconds. Low orexin produces long, slow blinks. High orexin produces quick, crisp blinks. The ratio of long blinks (>300ms) to short blinks is a sensitive discriminator between alert and pre-drowsy states.
Electrodermal activity +
Skin conductance measured from stainless-steel electrodes on the nose bridge. Captures both tonic level (baseline sympathetic tone) and phasic responses (momentary sympathetic bursts). Orexin neurons project directly to the sympathetic nervous system — a drop in EDA with a simultaneous rise in HRV signals autonomic dissociation, a hallmark of orexin failure.
Core body temperature +
Ear canal temperature via high-precision digital thermistor (MAX30205, ±0.1°C). The ear canal is the closest non-invasive approximation of brain temperature. Orexin regulates thermoregulation — when levels drop, the body initiates heat dumping via peripheral vasodilation. Pairs with wrist temperature to compute the distal-proximal gradient (DPG).
In-ear PPG heart rate +
Photoplethysmography from a MAX30102 sensor in the earbud extension. In-ear PPG provides a cleaner heart rate signal than wrist-based PPG because the ear canal has minimal motion artifact. Used for high-fidelity heart rate and HRV when glasses are worn, freeing the watch PPG for redundancy and sleep-only tracking.
Ambient lux calibration +
Visible-spectrum light level at the eye measured by a BH1750 sensor on the glasses bridge. Not an orexin signal itself — this is the calibration channel. Pupil size responds to both light and autonomic state. Without subtracting the pupillary light reflex, every pupil measurement is contaminated. This sensor makes the difference between measuring room brightness and measuring the brain.
Watch — wrist, 24/7
Heart rate +
Continuous heart rate from wrist PPG (MAX30102). The 24/7 cardiovascular baseline. Orexin maintains sympathetic tone — resting heart rate elevation or depression relative to personal baseline tracks overall autonomic state. Essential for sleep-stage estimation overnight when glasses are not worn.
Heart rate variability +
Beat-to-beat variation computed from PPG R-R intervals. Metrics: RMSSD (parasympathetic index), SDNN (overall variability), LF/HF ratio (sympathovagal balance, interpretation contested). Orexin-A administration in animal models consistently shifts autonomic balance toward sympathetic dominance. A sudden HF spike indicates the parasympathetic "sleep switch" engaging without orexin opposition.
SpO₂ +
Blood oxygen saturation from MAX30102 red/IR ratio. A weaker orexin proxy but clinically relevant — orexin-deficient patients show characteristic desaturation patterns during sleep. Included at zero additional hardware cost since the MAX30102 provides SpO₂ alongside heart rate.
Activity / steps +
Step count and activity intensity from LIS3DH 3-axis accelerometer. Context signal — the fusion model needs to distinguish "heart rate is elevated because of orexin" from "heart rate is elevated because the user is walking upstairs." Also captures micro-tremors in the hand that may indicate REM atonia leaking into wakefulness, a hallmark of orexin loss.
Sleep stages +
Estimated sleep architecture from overnight heart rate + motion patterns. Narcolepsy patients have characteristic sleep fragmentation — frequent wake-after-sleep-onset (WASO), sleep-onset REM periods (SOREMPs), and reduced deep sleep. The watch is the only device worn during sleep, making this signal exclusively available from the wrist.
Wrist skin temperature +
Distal skin temperature from MAX30205 digital thermistor (±0.1°C) mounted against the wrist skin on the watch back. Combined with chest temperature from the shirt pod, this computes the distal-proximal gradient (DPG) — when wrist temperature rises toward chest temperature, the body is dumping heat to prepare for sleep. The DPG is one of the strongest published predictors of imminent sleep onset, particularly in narcolepsy.
Shirt Pod — chest
ECG waveform +
Single-lead electrocardiogram from AD8232 analog front end connected to conductive silver-fiber textile electrodes integrated into the shirt. Clinical-grade R-peak detection at 250Hz sampling rate. Provides the highest-fidelity cardiac signal in the system — superior to wrist PPG for precise R-R interval measurement required for research-grade HRV analysis.
Clinical-grade HRV +
Heart rate variability computed from ECG R-R intervals rather than PPG. ECG-derived HRV is the gold standard for wearable autonomic assessment — R-peak timing from ECG has millisecond precision versus the ~10ms jitter typical of wrist PPG. This is the primary HRV input to the orexin fusion model when the shirt is worn.
ECG-derived respiration +
Breathing rate extracted from R-wave amplitude modulation in the ECG signal (EDR technique). As the chest expands and contracts, the distance between the heart and the electrodes changes, modulating R-wave amplitude. This validated technique provides respiration rate without a separate sensor. Orexin stimulates respiratory neurons — irregular or shallow breathing patterns signal reduced orexin drive.
Chest skin temperature +
Proximal skin temperature from MAX30205 (±0.1°C) mounted on the shirt pod against the chest. The "core" reference for the distal-proximal gradient. Chest skin temperature is more stable than wrist temperature and closer to true core body temperature. When the gap between wrist and chest temperatures narrows, it indicates peripheral vasodilation — the body preparing for sleep.
3 coordinated devices, time-synchronized to <10ms
Glasses
Arousal node
Inward-facing IR camera for controlled-light pupillometry. Nose-bridge EDA. In-ear extension for core temperature and motion-resistant PPG. Worn during waking hours.
Watch
Metabolic node
24/7 cardiovascular and metabolic baseline. The only device worn during sleep. Tracks distal skin temperature for the distal-proximal gradient — one of the strongest predictors of imminent sleep onset.
Shirt Pod
Stability node
Clinical-grade single-lead ECG via conductive textile electrodes. ECG-derived respiration. Master clock for inter-device synchronization. High-resolution local data logging.
The Orexin Activity Index
Orexin Activity 73 / 100 Active Alert

A continuous 0–100 score representing estimated orexin system activity relative to a personalized baseline. Updated every 30 seconds.

Calibrated per individual over 2–3 weeks of passive data collection. The system learns your autonomic baseline, not population averages — essential for orexin-deficient phenotypes.

deep sleep → drowsy → calm alert → active alert → peak arousal
01 — Problem

The most invasive measurement in sleep medicine.

Orexin is the master regulator of wakefulness, arousal, and autonomic stability. Loss of orexin causes narcolepsy. Excess or dysregulation is implicated in idiopathic hypersomnia, circadian collapse, and a growing list of neuropsychiatric conditions.

Direct measurement requires a lumbar puncture. It is invasive, single-snapshot, and confined to clinical settings. There is no continuous tool for orexin activity in free-living conditions — which limits research, blocks longitudinal studies, and leaves the rapidly expanding pipeline of orexin-targeting therapeutics without an objective endpoint.

02 — Approach

Reading the orexin system through its downstream effects.

Orexin neurons drive a coordinated cascade: pupil dynamics, heart rate variability, electrodermal activity, thermoregulation, respiratory patterning. Each is measurable. Together, they form a fingerprint of the orexin system at work.

We capture sixteen autonomic signals from three coordinated wearable devices, time-synchronized to within 10 milliseconds, and fuse them into a continuous Orexin Activity Index — calibrated to each individual's baseline.

"Pupillometry is a reliable readout of orexin neuron activity."

Grujic et al. — Control and coding of pupil size by hypothalamic orexin neurons. Nature Neuroscience, 2023.

We do not invent new science. We engineer published findings into a coordinated wearable form factor for the first time.

03 — System

Four components. One signal.

Each device contributes a distinct subset of the autonomic signature. The system degrades gracefully — partial sensor availability still produces a confidence-weighted index.

01 / Glasses
Arousal node
Pupil · EDA · Core temperature · In-ear PPG
Inward-facing IR camera with 940nm illumination for controlled-light pupillometry through prescription frames. Nose-bridge electrodermal activity. In-ear extension for core body temperature and motion-resistant heart rate.
02 / Watch
Metabolic node
HR · HRV · SpO₂ · Sleep · Wrist temperature
The always-on synchronization hub. All sensor data from glasses, shirt, and watch is time-stamped, fused, and coordinated through the watch. Every signal is raw-accessible and logged at research-grade resolution. The only device worn during sleep.
03 / Shirt Pod
Stability node
ECG · HRV · Respiration · Chest temperature
Clinical-grade single-lead ECG via conductive textile electrodes. ECG-derived respiration. Chest skin temperature. Local high-resolution logging to microSD.
04 / Pod
Power & compute
Charging · Sync · Future expansion
Power infrastructure with a forward-compatible internal architecture. Reserved expansion slots for on-device AI inference and future biofluid sensing modules as those technologies mature.
04 — Honest framing

An autonomic digital twin. Not a needle.

This system does not measure orexin molecules. No wearable can. It estimates the autonomic instability that results from orexin dysregulation, calibrated to each individual phenotype.

It is a research instrument and personal data logger. It is not an FDA-cleared medical device. It is not a diagnostic tool for narcolepsy or any other condition. It should never be used for safety-critical decisions.

Status — Pre-prototype

Hardware design finalized. First build in progress.

We are actively seeking research partnerships with sleep laboratories and pharmaceutical research groups working on orexin-related conditions and therapeutics. Co-design input on the v1 specification is open through Q3 2026.

Get in touch →
05 — Contact
Orexin System Corp
feng@orexinsystem.com
West Vancouver, BC, Canada