Auricular Electrophysiology Demonstrates Enhanced Stability Under Vehicle Vibration and Acceleration

Real-time cortical and cardiac electrophysiology provides direct insight into brain and heart function, revealing early signs of neurological or circulatory instability, supporting medics with rapid triage, continuous monitoring, and intervention during transport, evacuation, or battlefield operations. However, their deployment remains limited by motion and vibration artifacts that degrade signal integrity in dynamic field settings. This study examines the feasibility of auricular (in-ear) electrode configurations for improved signal robustness compared with scalp and wrist sites under both sustained vibration and dynamic acceleration within custom-built electrodes on matched electronics.

Simultaneous recordings were obtained from the auricular canal (electroencephalogram [EEG] and electrocardiogram [ECG]), temple (F7 EEG), and wrist (ECG) in n = 5 participants across 3 motion conditions: engine off (parked), engine on (parked), and city driving (∼30 mph). Signal quality was assessed via waveform morphology, frequency-domain signal-to-noise ratio (SNR), coherence, and root mean square error (RMSE) relative to inertial measurement unit (IMU) data.

Across 5 participants, auricular channels showed reduced 60 Hz interference (∼-8 dB) and slightly higher SNR (median increase of 2 dB during driving) compared with scalp and wrist sites. This trend may reflect mechanical and electromagnetic shielding because of the enclosure of the canal. Under motion conditions, coherence and RMSE suggest weaker coupling between IMU motion and auricular signals compared with on-body sites (∼0.03 higher RMSE and ∼0.05×10-3 lower coherence).

Auricular recordings indicate feasible signal integrity under vehicular motion, compared to conventional scalp and wrist placements. These preliminary results indicate suitability for neurocardiac monitoring.