Earbud cardiac monitoring works best with left finger contact
Finger-to-Ear ECG: Systematic Evaluation of an Earbud-Based Cardiac Monitoring Approach
Human-Computer Interaction
Summary
Measuring your heart's electrical signals clearly and comfortably using earbuds can be tricky. The authors tested a new way to get these signals by touching one finger to an earbud's back. They found that using the left finger gave the best heart signal quality, while the right finger or walking made it harder to read. This method balances accurate heart readings with user comfort in everyday situations.
What this means in practice
- •For wearable device manufacturers: Design earbuds with left-finger contact electrodes to provide accurate and comfortable heart rate monitoring for daily users.$Commercial implications: Enables selling earbuds with robust cardiac monitoring features that outperform right finger or walking scenarios.
- •For mobile health app developers: Create apps that read finger-to-ear ECG signals to offer unobtrusive heart health insights during various user activities.
Authors
Philipp Lepold, Paula Breitling, Jonas Hummel, Tobias Röddiger, Michael Beigl
Abstract
Ear-ECG enables unobtrusive cardiac monitoring, but existing approaches often struggle with low signal amplitudes and limited morphology preservation. We evaluate a finger-to-ear ECG paradigm that combines an in-ear electrode with a rear housing finger-contact electrode in a speaker-equipped earbud. A study with 30 participants investigated four finger-to-ear electrode geometries against chest-reference ECG and additionally assessed robustness under music playback, talking, and walking disturbances. Left-finger configurations achieved R peak detection F1-scores >99% with high agreement of key ECG morphology features. In contrast, right finger configurations as well as walking led to severe signal degradation. The results reveal a trade-off: while cross-body setups provided the highest signal fidelity, users preferred same-side contacts for comfort reasons. This establishes finger-to-ear ECG as a robust, morphology-aware paradigm for opportunistic sensing in earables.