It started as a sleep-aware remote. Now it's an AI health tracker.

PulseApnea started as a sleep-aware wristband that turned your devices off once you fell asleep. After months of research and development it is now an AI-powered sleep apnea wristband, aimed at a condition that affects an estimated 1 billion people worldwide.

See how it evolved View the data
The PulseApnea wristband with its top cover lifted off, showing the battery, circuit board and USB-C port
What changed
V1 · May 2026Sleep-aware remote
NOW · Oct 2026AI health tracker
Job
Turn the room off when you fall asleep
Track fitness and screen for sleep apnea
Sensors
Motion, heart rate
Motion, heart rate, SpO₂, microphone
Intelligence
Rule-based thresholds
AI model trained on sleep apnea patient data
At night
Sends IR off commands
Sends IR off commands and flags disrupted breathing
During the day
Idle
Activity, movement and heart rate
01 · Development timeline

From first idea to where it stands today

  1. Phase 01May 2026
    Concept

    The sleep-aware remote

    Another IoT sleep remote, built for convenience: a wrist device that notices when you have fallen asleep and switches off nearby electronics to save electricity.

    Diagram of the original concept: the sleep-aware watch signals Home Assistant, which commands an IR blaster to switch off the TV
    Concept: watch to Home Assistant to IR blaster to TV
  2. Phase 02June 2026
    Prototype

    A physical watch that talks to the room

    Serious prototyping began. The watch became a physical device and the infrared remote integration was completed, so it could turn off the devices around the user.

    3D model of the first prototype: a light blue enclosure holding the microcontroller and circuit board, with the battery lifted off above it
    First prototype model: enclosure, board and battery
  3. Phase 03August 2026
    Pivot

    From convenience to health

    While building sleep tracking we found that the methods that reliably tell whether you are asleep also produce detailed physiological data. We wanted that data to deliver more value, and began linking it to health conditions. Obstructive sleep apnea (OSA) affects an estimated 1 billion people worldwide, so we pivoted to researching a device that could help.

  4. Phase 04September 2026
    PulseApnea

    First polished prototype

    The first polished PulseApnea prototype was built. We upgraded the sensors and microcontroller for the new purpose, contacted local hospitals for training data, and began developing and training our own machine learning models to push detection accuracy further.

    The new hardware centres on a Seeed XIAO nRF52840 connected over I²C to a pulse sensor. We drew the schematic and routed a custom two-layer board in KiCad.

    KiCad schematic wiring the XIAO nRF52840 to the pulse sensor over SDA, SCL, power and ground
    Schematic: microcontroller and sensor wiring
    Routed two-layer PCB layout showing the XIAO footprint and the sensor pads
    Routed board layout, front and back copper
    KiCad PCB editor with the wristflex board fully routed and no unrouted nets
    KiCad PCB editor
  5. Phase 05 · NowOctober 2026
    Current build

    Companion app and ongoing model training

    We have started building our own app to pair with the device, while continuing to improve and train the machine learning model in parallel.

  6. NextDate to be set
    Roadmap

    Validate on more patients

    The model now reaches 80% accuracy on the four-class severity task, but on a small labelled set. Next: confirm it holds with participant-grouped cross-validation and additional patient data, and keep improving the CNN.

02 · Functions & data

What the device measures, and what it does with it

Data flow

01 SENSE
Sensors
Accelerometer, optical heart rate (PPG), SpO₂, and a PDM microphone
02 PROCESS
On-device processing
Filtering, feature extraction, sleep-stage estimation
03 INFER
AI model
Trained on sleep apnea patient data; flags breathing disruption
04 ACT
Outputs
IR off commands (via Home Assistant and an IR blaster), health insights

Core functions

Companion app
IN DEVELOPMENT
Oct 2026
development started
Pairs with
PulseApnea wristband
Status
In development
IR device control
ORIGINAL
5 m
effective IR range
Devices
Fans, TVs, speakers
Codes stored
Most common fan, TV and speaker codes
Apnea screening
AI
80%
sensitivity for severe apnea
Inputs
SpO₂, heart rate, motion, microphone
Output
Night-level severity: normal, mild, moderate or severe
Heart rate & SpO₂
HEALTH
10 Hz
sensor data rate (session log)
Sensor
MAX30102 (PPG)
Error vs ref.
± 5 bpm vs Apple Watch
Motion sensing
SENSING
Motion
wrist movement and activity sensing
Tracks
Wrist movement and activity level
Inputs
Accelerometer
Battery & power
HARDWARE
8h
battery life, typical use
Capacity
200 mAh
Charge time
1 h

Training data

40
participants
80
nights recorded
Source: Kaggle “Polysomnographic sleep data” (yfrite/polysom). Two nights per participant. 20 participants have AHI labels (1 normal, 2 mild, 7 moderate, 10 severe), so the model is evaluated on a small labelled set. Local hospitals have been contacted for additional training data.

Model performance

Metric Value What it means
Accuracy80%Nights placed in the correct severity class
Sensitivity (severe)75%Severe nights correctly flagged
Specificity (severe)68.8%Non-severe nights correctly cleared
F1 score0.718Macro and weighted F1 are both 0.718
Model type: night-level severity classifier (XGBoost and CNN branches, in development) · Evaluated on [N] held-out patients
03 · Data explorer

What sleep apnea looks like in real overnight data

Interactive charts built from open, clinically scored polysomnography recordings on PhysioNet. They illustrate the signals our model works with.

Severity of the 25 patients

Patients grouped by apnea-hypopnea index (AHI), the number of breathing events per hour of sleep.

Who has apnea: age vs BMI

Each dot is one patient, colored by severity. Hover for their AHI.

A night of apnea: blood oxygen and heart rate

Scroll or pinch to zoom, drag to pan. Shaded bands are minutes scored as apnea by clinicians.

Your PulseApnea recording

Sleep stages and breathing events

Sources, both under the Open Data Commons Attribution License: Apnea-ECG Database (Penzel et al.) and the St. Vincent's University Hospital / UCD Sleep Apnea Database. Charts show a few selected recordings; heart rate comes from machine-detected beats and may include artifacts.