Wearable Smart Textiles for Long-Term Electrocardiography Monitoring—A Review

The continuous and long-term measurement and monitoring of physiological signals such as electrocardiography (ECG) are very important for the early detection and treatment of heart disorders at an early stage prior to a serious condition occurring. The increasing demand for the continuous monitoring of the ECG signal needs the rapid development of wearable electronic technology. During wearable ECG monitoring, the electrodes are the main components that affect the signal quality and comfort of the user. This review assesses the application of textile electrodes for ECG monitoring from the fundamentals to the latest developments and prospects for their future fate. The fabrication techniques of textile electrodes and their performance in terms of skin–electrode contact impedance, motion artifacts and signal quality are also reviewed and discussed. Textile electrodes can be fabricated by integrating thin metal fiber during the manufacturing stage of textile products or by coating textiles with conductive materials like metal inks, carbon materials, or conductive polymers. The review also discusses how textile electrodes for ECG function via direct skin contact or via a non-contact capacitive coupling. Finally, the current intensive and promising research towards finding textile-based ECG electrodes with better comfort and signal quality in the fields of textile, material, medical and electrical engineering are presented as a perspective.

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A comfortability and signal quality study of conductive weave electrodes in long-term collection of human electrocardiographs

Textile Research Journal ◽

10.1177/0040517518786275 ◽

2018 ◽

Vol 89 (11) ◽

pp. 2098-2112 ◽

Cited By ~ 4

Author(s):

Xueliang Xiao ◽

Ke Dong ◽

Chenhao Li ◽

Guanzheng Wu ◽

Hongtao Zhou ◽

...

Keyword(s):

Skin Irritation ◽

Woven Fabrics ◽

Comfort Level ◽

Signal Quality ◽

High Quality ◽

Contact Impedance ◽

Ecg Signals ◽

Skin Contact ◽

Textile Electrodes

Long-term electrocardiogram (ECG) recording can reveal some vital cardiovascular disorders and provide warning of human sudden cerebral or vascular diseases in advance. This requires high-quality ECG skin electrodes. Gel (Ag/AgCl) electrodes were reported to have good signal quality in ECG acquisition, but easily caused human skin irritation or allergy. Consequently, textile electrodes have attracted more attention for long-term ECG acquisition. In this paper, eight woven fabrics with diverse yarns and weft densities were fabricated in plain and honeycomb structures. The fabrics were investigated in terms of comfortability, fabric–skin contact impedance and acquired bio-signal quality. Honeycomb weave electrodes were measured with a high comfort level from subjective and objective views, including pleasant tactile comfort, high visual acceptance, good air permeability and good heat transfer. Weave electrodes made of all conductive filaments in high density had low skin contact impedance and high-quality ECG signals. An increase of compression load on weave electrodes resulted in a decrease of contact impedance with a high signal quality. A conductive honeycomb weave with unit repeat of 6*6 warps*wefts presented the highest score of acquired ECG signals of all studied electrodes based on the qualities of the QRS complex, P and T waves, R peak amplitude and variation and signal-to-noise ratio. This study contributes to the future design and fabrication of textile electrodes using honeycomb weave in long-term and real-time collection of human ECGs.

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Development of Washable Silver Printed Textile Electrodes for Long-Term ECG Monitoring

Sensors ◽

10.3390/s20216233 ◽

2020 ◽

Vol 20 (21) ◽

pp. 6233

Author(s):

Abreha Bayrau Nigusse ◽

Benny Malengier ◽

Desalegn Alemu Mengistie ◽

Granch Berhe Tseghai ◽

Lieva Van Langenhove

Keyword(s):

Silver Chloride ◽

Signal To Noise Ratio ◽

Polyester Fabric ◽

Signal Quality ◽

Ecg Monitoring ◽

Textile Electrodes ◽

Elastic Strap ◽

Silver Silver ◽

Silver Silver Chloride

Long-term electrocardiography (ECG) monitoring is very essential for the early detection and treatment of cardiovascular disorders. However, commercially used silver/silver chloride (Ag/AgCl) electrodes have drawbacks, and these become more obvious during long-term signal monitoring, making them inconvenient for this use. In this study, we developed silver printed textile electrodes from knitted cotton and polyester fabric for ECG monitoring. The surface resistance of printed electrodes was 1.64 Ω/sq for cotton and 1.78 Ω/sq for polyester electrodes. The ECG detection performance of the electrodes was studied by placing three electrodes around the wrist where the electrodes were embedded on an elastic strap with Velcro. The ECG signals collected using textile electrodes had a comparable waveform to those acquired using standard Ag/AgCl electrodes with a signal to noise ratio (SNR) of 33.10, 30.17, and 33.52 dB for signals collected from cotton, polyester, and Ag/AgCl electrodes, respectively. The signal quality increased as the tightness of the elastic strap increased. Signals acquired at 15 mmHg pressure level with the textile electrodes provided a similar quality to those acquired using standard electrodes. Interestingly, the textile electrodes gave acceptable signal quality even after ten washing cycles.

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Fully organic compliant dry electrodes self-adhesive to skin for long-term motion-robust epidermal biopotential monitoring

Nature Communications ◽

10.1038/s41467-020-18503-8 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Lei Zhang ◽

Kirthika Senthil Kumar ◽

Hao He ◽

Catherine Jiayi Cai ◽

Xu He ◽

...

Keyword(s):

Body Movement ◽

Deep Tendon Reflex ◽

Conductive Polymer ◽

Motion Artifacts ◽

Contact Impedance ◽

Skin Contact ◽

Dry Electrodes ◽

Tendon Reflex ◽

Dry Electrode

Abstract Wearable dry electrodes are needed for long-term biopotential recordings but are limited by their imperfect compliance with the skin, especially during body movements and sweat secretions, resulting in high interfacial impedance and motion artifacts. Herein, we report an intrinsically conductive polymer dry electrode with excellent self-adhesiveness, stretchability, and conductivity. It shows much lower skin-contact impedance and noise in static and dynamic measurement than the current dry electrodes and standard gel electrodes, enabling to acquire high-quality electrocardiogram (ECG), electromyogram (EMG) and electroencephalogram (EEG) signals in various conditions such as dry and wet skin and during body movement. Hence, this dry electrode can be used for long-term healthcare monitoring in complex daily conditions. We further investigated the capabilities of this electrode in a clinical setting and realized its ability to detect the arrhythmia features of atrial fibrillation accurately, and quantify muscle activity during deep tendon reflex testing and contraction against resistance.

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Flexible Carbon Nanotube-Based Polymer Electrode for Long-Term Electrocardiographic Recording

Materials ◽

10.3390/ma12060971 ◽

2019 ◽

Vol 12 (6) ◽

pp. 971 ◽

Cited By ~ 7

Author(s):

Miao Chi ◽

Jingjing Zhao ◽

Ying Dong ◽

Xiaohao Wang

Keyword(s):

Carbon Nanotube ◽

Weight Fraction ◽

Superior Performance ◽

Ecg Monitoring ◽

Ultrasonic Dispersion ◽

Contact Impedance ◽

Uniform Dispersion ◽

Long Term Monitoring ◽

Term Monitoring

The long-term monitoring of electrocardiogram (ECG) is critical for the accurate diagnosis and tracking of cardiovascular diseases (CVDs). However, the commercial Ag/AgCl electrode is not suitable for long-term monitoring due to skin allergies and signal degradation, caused by the conductive gel drying over time. In this paper, a flexible gel-free electrode, composed of a multi-wall carbon nanotube (MWCNT) and polydimethylsiloxane (PDMS), is proposed for long-term wearable ECG monitoring. To achieve uniform dispersion of MWCNTs in viscous PDMS, we developed a novel parallel solvent-assisted ultrasonic dispersion method, wherein the organic solvent n–Hexane served as a dispersion to avoid MWCNT aggregates. The properties of the MWCNT/PDMS electrode were assessed through structural characterization, contact impedance tests, ECG measurements, and biocompatibility tests. When the MWCNT weight fraction reached 5.5 wt%, the skin-electrode contact impedance of the MWCNT/PDMS electrode was lower than that of the Ag/AgCl electrode below 100 Hz. In daily ECG monitoring, the MWCNT/PDMS electrodes showed superior performance against motion artifact compared to the Ag/AgCl electrode. After seven days of wearing the MWCNT/PDMS electrode, ECG signals did not degrade and no side effects, such as skin redness and swelling, were observed. Thus, this electrode could enable long-term ECG monitoring in wearable healthcare systems.

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Optimization of signal quality over comfortability of textile electrodes for ECG monitoring in fog computing based medical applications

Future Generation Computer Systems ◽

10.1016/j.future.2018.04.024 ◽

2018 ◽

Vol 86 ◽

pp. 515-526 ◽

Cited By ~ 60

Author(s):

Wanqing Wu ◽

Sandeep Pirbhulal ◽

Arun Kumar Sangaiah ◽

Subhas Chandra Mukhopadhyay ◽

Guanglin Li

Keyword(s):

Fog Computing ◽

Medical Applications ◽

Signal Quality ◽

Ecg Monitoring ◽

Textile Electrodes

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Applying Noncontact Sensing Technology in the Customized Product Design of Smart Clothes Based on Anthropometry

Sensors ◽

10.3390/s21237978 ◽

2021 ◽

Vol 21 (23) ◽

pp. 7978

Author(s):

I-Jan Wang ◽

Wei-Ting Chang ◽

Wen-Hao Wu ◽

Bor-Shyh Lin

Keyword(s):

Product Design ◽

Development Process ◽

Skin Irritation ◽

Three Dimensional ◽

Motion Artifacts ◽

Signal Quality ◽

Conductive Materials ◽

Dry Electrodes ◽

Sensing Technology

Electrocardiograms (ECGs) provide important information for diagnosing cardiovascular diseases. In clinical practice, the conventional Ag/AgCl electrode is generally used; however, it is not suitable for long-term ECG measurement because of the risk of allergic reactions on the skin and the dying issue of electrolytic gels. In previous studies, several dry electrodes have been proposed to address these issues. However, most dry electrodes, which are the mode of conductive materials, have to contact the skin well and are easily affected by motion artifacts in daily life. In the smart clothes developed in this study, a noncontact electrode was used to assess the biopotential across the clothes to prevent skin irritation and discomfort. Moreover, a three-dimensional parametric model based on anthropometric data was built, and the technique of customized product design was introduced into the smart clothes development process to reduce the influence of motion artifacts. The experimental results show that the proposed smart clothes can maintain a good ECG signal quality stably under motion from different activities.

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Noncontact ECG Monitoring by Capacitive Coupling of Textiles in a Chair

Journal of Healthcare Engineering ◽

10.1155/2021/6698567 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Po-Cheng Su ◽

Ya-Hsin Hsueh ◽

Ming-Ta Ke ◽

Jyun-Jhe Chen ◽

Ping-Chen Lai

Keyword(s):

Measurement System ◽

Capacitive Coupling ◽

Ecg Signal ◽

Ecg Monitoring ◽

Heart Activity ◽

Textile Electrodes ◽

Conductive Textile ◽

Electrocardiogram Ecg ◽

T Waves

Some patients are uncomfortable with being wired to a device to have their heart activity measured. Accordingly, this study adopts a noncontact electrocardiogram (ECG) measurement system using coupled capacitance in a conductive textile. The textiles can be placed on a chair and are able to record some of the patient’s heart data. Height and distance between the conductive textile electrodes were influential when trying to obtain an optimal ECG signal. A soft and highly conductive textile was used as the electrode, and clothing was regarded as capacitance insulation. The conductive textile and body were treated as the two electrode plates. This study found that placing the two conductive textiles at the same height provided better data than different heights. The system also enabled identifying the P, Q, R, S, and T waves of the ECG signal and eliminated unnecessary noise successfully.

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Biomarkers in patients after chemotherapy

Medical alphabet ◽

10.33667/2078-5631-2021-19-49-53 ◽

2021 ◽

pp. 49-53

Author(s):

F. R. Akildzhonov ◽

J. I. Buziashvili ◽

I. S. Stilidi ◽

E. U. Asymbekova ◽

E. V. Artamonova

Keyword(s):

Cancer Patients ◽

Early Stage ◽

Heart Diseases ◽

Rapid Development ◽

Molecular Genetic ◽

Myocardial Damage ◽

Long Term Follow Up

Along with the rapid development of molecular genetic testing, immunotherapy and targeted antitumor therapy in Oncology, the risk of cardiotoxicity associated with chemotherapy remains a keystone that directly affects the survival and quality of life of patients after therapy. Elevated levels of troponin, BNP/NT-proBNP, myeloperoxidase, and D-dimer have been associated with increased all-cause mortality in cancer patients and have been shown in numerous studies to predict the risk of heart failure and myocardial damage associated with chemotherapy. Specifi diagnostic algorithms are particularly important for risk stratifiation, monitoring, and long-term follow-up of cancer patients receiving chemotherapy. Biomarkers are the basis for diagnosing acute and chronic heart diseases. However, their role in the timely detection and monitoring of cardiotoxicity is not well understood. Thus, clinicians should identify adverse effects at an early stage, seeking to take appropriate preventive measures before the occurrence of a permanent or irreversible dysfunction of the heart. In dynamic cardiology, biomarkers are a key tool for risk assessment, diagnosis, and monitoring of cancer-related cardiotoxicity and cancer therapy. The complex interaction of such branches of medicine as oncology, oncotherapy and cardiology indicates the need for a multi-disciplinary cardio-oncological approach to ensure optimal quality of treatment

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Performance and Signal Quality Analysis of Electrocardiogram Textile Electrodes for Smart Apparel Applications

Frontiers in Electronics ◽

10.3389/felec.2021.685264 ◽

2021 ◽

Vol 2 ◽

Author(s):

Katherine Le ◽

Amir Servati ◽

Saeid Soltanian ◽

Peyman Servati ◽

Frank Ko

Keyword(s):

Heart Rate ◽

Electrode Materials ◽

Silver Chloride ◽

Quality Analysis ◽

Signal Quality ◽

Ecg Signal ◽

Skin Contact ◽

Textile Electrodes ◽

Textile Electrode

Electronic textile (e-textile) systems applied to biological signal monitoring are of great interest to the healthcare industry, given the potential to provide continuous and long-term monitoring of healthy individuals and patients. Most developments in e-textiles have focused on novel materials and systems without systematic considerations into how the hierarchical structure of fibrous assemblies may influence performance and compatibility of the materials during use. This study examines mechanisms underlying the stability and quality of textile-based electrocardiogram (ECG) electrodes used in a smart bra. Signal quality of the biometric data obtained affects feedback and user experience and may be influenced by characteristics and properties of the material. Under stationary and dynamic conditions, analysis of the raw ECG signal and heart rate, with respect to textile-electrode material properties have been performed. Currently, there is no standardized procedure to compare the ECG signal between electrode materials. In this study, several methods have been applied to compare differences between silver-based textile electrodes and silver/silver-chloride gel electrodes. The comparison methods serve to complement visual observations of the ECG signal acquired, as possible quantitative means to differentiate electrode materials and their performance. From the results obtained, signal quality, and heart rate (HR) detection were found to improve with increased skin contact, and textile structures with lower stretch and surface resistance, especially under dynamic/movement test conditions. It was found that the performance of the textile electrode materials compared exceeded ECG signal quality thresholds previously established for acceptable signal quality, specifically for the kurtosis (K > 5), and Pearson correlation coefficients (r ≥ 0.66) taken from average ECG waveforms calculated.

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Dry Wearable Textile Electrodes for Portable Electrical Impedance Tomography

Sensors ◽

10.3390/s21206789 ◽

2021 ◽

Vol 21 (20) ◽

pp. 6789

Author(s):

Chang-Lin Hu ◽

I-Cheng Cheng ◽

Chih-Hsien Huang ◽

Yu-Te Liao ◽

Wei-Chieh Lin ◽

...

Keyword(s):

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Signal Quality ◽

Skin Injury ◽

Impedance Tomography ◽

Textile Electrodes ◽

Lung Aeration ◽

Imaging Results ◽

Regional Lung

Electrical impedance tomography (EIT), a noninvasive and radiation-free medical imaging technique, has been used for continuous real-time regional lung aeration. However, adhesive electrodes could cause discomfort and increase the risk of skin injury during prolonged measurement. Additionally, the conductive gel between the electrodes and skin could evaporate in long-term usage and deteriorate the signal quality. To address these issues, in this work, textile electrodes integrated with a clothing belt are proposed to achieve EIT lung imaging along with a custom portable EIT system. The simulation and experimental results have verified the validity of the proposed portable EIT system. Furthermore, the imaging results of using the proposed textile electrodes were compared with commercial electrocardiogram electrodes to evaluate their performance.

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