Reducing Noise in E-Textile Health Wearables Using Remotely-Powered, Single-Wire Active Electrodes
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Author
Rosenthal, James
Leu, Dragos
Chetelat, Olivier
DOI
10.1515/bmt-2025-1001
Abstract
Methods The AE design enables simultaneous powering and data acquisition with only one wire per AE. The architecture employs two AEs and a remote monitor with digital logic and a biopotential analog front-end. The AEs are powered by ACcoupled high frequency (1 MHz) square wave signals output from the digital logic. A diode rectifier converts this signal to DC to power an amplifier. The amplifier is configured such that the powering signal can transparently pass across the low-impedance output through the skin and back to the monitor, while the high-impedance inverting input measures low frequency (<300 Hz) biopotentials, superimposing the biopotentials on the powering signals.
Results Preliminary measurements demonstrate the feasibility of powering the active dry electrodes at 50 cm distance from the monitor using a conductive textile with DC impedance >30 Ω. Using dry electrodes to measure ECG in a static measurements with an ECG simulator, the remotely-powered, single-wire active electrodes improved rejection of 50 Hz mains coupling by 39 dB compared to a fully passive electrodes in the same setup.
Conclusion The preliminary design of remotely-powered, single-wire active electrodes indicate a promising path towards improving signal quality for e-textile health monitors. Our preliminary design significantly improved 50 Hz mains rejection compared to fully passive electrodes with conductive fabric wiring. Future work includes noise and safety characterization per IEC 60601 standards, as well as full integration into a wearable e-textile vest.
Publication Reference
BMT 2025, Muttenz (Switzerland)
Year
2025-09-11