Logix Pulse is a free app for the Polar H10 chest strap. It records the
strap's raw ECG and turns it into a daily check you can read.

MORNING CHECK · 3 MIN
Lie down, press one button. The strap's raw ECG is recorded, the first
minute is skipped while you settle, and the result opens by itself:
resting HRV (RMSSD), heart rate and breathing rate, with the exact window
that was analysed.

YOUR RAW ECG, FREE TO EXPORT
Every recording keeps the strap's raw ECG, 130 samples a second. Scroll
through it and see which beats were left out of HRV and why. Export it in
one tap, free: a CSV with every ECG sample, RR interval and motion reading
for your own analysis, or a PDF of ECG strips (25 mm/s, 10 mm/mV) to print.

YOUR USUAL RANGE, NOT A SCORE
After seven mornings the app shows where this week sits against your own
usual range, on a 28-day chart with a 7-day average and resting heart rate
on the same dates. No readiness number: your trend is compared with
yourself.

YOUR ECG WAVEFORM
QRS duration, QT and QTc (Fridericia and Bazett), PR interval, J point,
ST level and T waves, measured on every clean beat of the recording. A
morning check also shows each value against the reference ranges of the
international recommendations for ECG interpretation in athletes (Sharma
et al., 2017): ranges for athletes, written for the 12-lead ECG rather
than for a chest strap.

EVERY NUMBER TESTED, RESULTS IN THE APP
Settings → About → Accuracy lists what each measurement was tested
against and how close it came: beat detection on the MIT-BIH Arrhythmia
Database (99.6 % of beats found), waveform boundaries against
cardiologists' marks on the QT Database and LUDB, waveform values against
two hospital ECG machine programs on 21,799 PTB-XL ECGs, HRV against
NeuroKit2, breathing rate against a metronome and the BIDMC dataset.

BREATHING RATE FROM THE STRAP
Measured from the chest strap's own motion sensor fused with the ECG, not
estimated from heart rate alone. Checked against paced breathing at 6, 10,
15 and 20 breaths per minute.

THRESHOLD TEST
A guided ramp on a trainer or treadmill estimates the top of your easy
zone from heart-rate variability (DFA alpha 1) and breathing rate. The page
says what it finds, how precise it is, and that it is not a lactate test.

FREE RECORDING
Any length from 30 seconds. Recordings keep running with the screen off.

WHAT WE DON'T DO
Logix Pulse is not a medical device. It does not detect or name any
condition and does not replace a doctor. It shows measurements for fitness
and curiosity.

PRIVACY
No account. A random install id is the only identifier. Recordings are
uploaded for analysis only if you allow it, can be deleted any time from
the app, and are never sold or used for advertising.
Privacy policy: https://logixmotion.com/pulse/privacy

REQUIRES
A Polar H10 chest strap (Bluetooth Low Energy). Other straps are not
supported.

Every current feature is free.

Polar and H10 are trademarks of Polar Electro Oy. Logix Pulse is an
independent app and is not affiliated with or endorsed by Polar.