Modeling the Design Characteristics of Woven Textile Electrodes for long−Term ECG Monitoring

Abstract

An electrocardiograph records the periodic voltage generated by the heart over time. There is growing demand to continuously monitor the ECG for proactive health care and human performance optimization. To meet this demand, new conductive textile electrodes are being developed which offer an attractive alternative to adhesive gel electrodes but they come with their own challenges. The key challenge with textile electrodes is that the relationship between the manufacturing parameters and the ECG measurement is not well understood, making design an iterative process without the ability to prospectively develop woven electrodes with optimized performance. Here we address this challenge by applying the traditional skin−electrode interface circuit model to woven electrodes by constructing a parameterized model of the ECG system. Then the unknown parameters of the system are solved for with an iterative MATLAB optimizer using measured data captured with the woven electrodes. The results of this novel analysis confirm that yarn conductivity and total conductive area reduce skin electrode impedance. The results also indicate that electrode skin pressure and moisture require further investigation. By closing this gap in development, textile electrodes can be better designed and manufactured to meet the demands of long−term ECG capture.

Recent Advances and Challenges in Textile Electrodes for Wearable Biopotential Signal Monitoring: A Comprehensive Review

“…It was found that the more space there was, the more noise there was as well as larger signal amplitude waveforms. Although resistance varies depending on the type of conductive yarn, there was little variation in capacitance with the type of yarn [132]. Most of the previous studies have shown that the larger the electrode is in diameter, the better the signal quality and the lower the skin contact impedance [133].…”

E-Textiles for Sports and Fitness Sensing: Current State, Challenges, and Future Opportunities

“…The electrodes form an integral part of the textile, which is then made into a wearable item that provides tight contact between the electrodes and the skin to reduce signal noise generated via the movement of the electrodes. Electrodes are mainly made by depositing conductive inks/paste on textiles using printing [155][156][157], coating the textile in the electrode material solution [158,159] or knitting [160,161], weaving [162,163], or embroidering [164,165] commercially available…”

“…The electrodes form an integral part of the textile, which is then made into a wearable item that provides tight contact between the electrodes and the skin to reduce signal noise generated via the movement of the electrodes. Electrodes are mainly made by depositing conductive inks/paste on textiles using printing [155][156][157], coating the textile in the electrode material solution [158,159] or knitting [160,161], weaving [162,163], or embroidering [164,165] commercially available conductive yarns or bespoke conductive yarns such as graphene-based yarn and PDOT: PSS-modified yarn [166,167] EMG is used to monitor muscle excitation using the biological electrical activity signals of the muscle, which can provide useful indicators of muscle activation patterns, fatigue, and performance. EMG has an important role in analysing dynamic movement and understanding the role of a muscle in a specific movement [171].…”

Wearable Ecg Device and Machine Learning for Heart Monitoring

“…Some cordless devices for ECG recordings and wireless data transmission via Bluetooth and Wi-Fi report only about heart rate, not ECG recordings and none of them provide signal quality assurance data that are directly compared with Holter monitoring [5][6][7][8]. Design of textile -based multichannel ECG systems that measure ECG signals from several parts of patients' torso were described in papers [9][10][11][12][13]. Smart or electronic textile (e-textiles) is a material that can interact with environment and users.…”