WHOOP ECG (electrocardiogram) Feature (1.0)

The WHOOP ECG Feature is a software-only mobile application that works with the WHOOP Strap wristband to record, display, and analyze a single-channel ECG similar to Lead I. It classifies heart rhythm as normal sinus rhythm, atrial fibrillation, low heart rate (≤50 bpm), or high heart rate (≥100 bpm) for informational use only by adults 22+, with the explicit caveat that users should not take clinical action without consulting a healthcare professional.

The device creates a single-channel Lead I ECG from wrist-worn electrodes on the WHOOP Strap, processes 30-second recordings via the ECG Strap Module firmware (incorporating the FDA-cleared B-Secur HeartKey library), displays results through a mobile app phone module, and stores data in a cloud module. It generates classification results including normal sinus rhythm, AFib, low/high heart rate, inconclusive, and unsuccessful readings—substantially similar to the Apple ECG App's approach and output categories, though WHOOP adds granularity by splitting high heart rate into separate AFib and non-AFib variants.

IEC 62368-1:2018 (thermal safety); EN 301-489-1 v2.2.3:2019, EN 301-489-3 v2.3.2:2023, EN 301-489-17 v3.2.5:2022 (RF/EMC); FCC 47 CFR Part 15 Subpart B:2024 (EMC); IEC 60601-2-47:2012 (ambulatory ECG systems); ANSI/AAMI EC57:2012(R2020) (database testing); IEC 62366-1:2015 (human factors/usability engineering).

Both devices are software-only OTC ECG applications intended for the same user population (adults 22+) using single-channel Lead I waveforms to discriminate AFib from normal sinus rhythm without replacing clinical diagnosis. The WHOOP feature demonstrated 96.2% sensitivity and 99.4% specificity for AFib/sinus classification in a clinical trial of ~540 subjects, with waveform morphology 99.4% acceptable, and human factors validation confirmed users could self-select appropriateness and interpret results correctly. Minor technological differences—such as data storage location (cloud vs. phone app) and expanded classification outputs (e.g., separate high heart rate categories)—do not raise new safety or effectiveness questions, particularly given comprehensive performance testing against predicate benchmarks.