Electrode Humidification Design for Artifact Reduction in Capacitive ECG Measurements

Area of Science:

• Biomedical Engineering
• Materials Science

Background:

• Wearable capacitive electrocardiogram (ECG) devices often suffer from motion artifacts due to electrode friction.
• Existing methods to mitigate motion artifacts, like water application, lack comprehensive analysis of the underlying mechanisms.

Purpose of the Study:

• To systematically investigate the effect of water on charge decay in textile electrodes.
• To propose and validate a controllable humidification design for suppressing motion artifacts in wearable ECG.
• To enhance the signal quality and stability of capacitive ECG acquisition.

Main Methods:

• Studied charge decay modes of textile electrodes, identifying free water evaporation as a key triboelectric charge dissipation pathway.
• Conducted theoretical analysis and experimental verification of water's role in accelerating charge decay.
• Developed an integrated ultrasonic atomization system for controllable electrode humidification.

Main Results:

• Demonstrated that water accelerates triboelectric charge decay via free water evaporation.
• The proposed controllable humidification design effectively suppresses motion artifacts.
• Achieved significant improvements in signal-to-noise ratio (33.32 dB at 25% RH, 22.67 dB at 65% RH) compared to non-humidified electrodes.
• Maintained stable signal quality across a range of ambient humidity levels.

Conclusions:

• Water's presence in textile electrodes significantly enhances triboelectric charge decay, thereby reducing motion artifacts.
• The controllable humidification system offers a practical and integrated solution for stable wearable ECG monitoring.
• This technology holds promise for improving the reliability of wearable health monitoring devices.