scholarly journals Ionic Liquid Regenerated Cellulose Membrane Electroless Plated By Silver Layer For ECG Signal Monitoring

2021 ◽  
Author(s):  
Xueli Fu ◽  
Yanping Wang ◽  
Wei Wang ◽  
Dan Yu
Keyword(s):  
Ionic Liquid ◽  
Skin Irritation ◽  
Regenerated Cellulose ◽  
Cellulose Membrane ◽  
Ecg Signal ◽  
Contact Impedance ◽  
Skin Contact ◽  
Dry Electrode ◽  
Wide Range

Abstract Flexible electrodes have attracted the interest of a wide range of people because they can monitor human health signals like ECG, EMG and EEG as wearable devices. However, PDMS-based membrane electrodes have the problem of difficulty in depositing metal layers, while fabric electrodes have high contact impedance. Furthermore, the widely used Ag/AgCl electrodes have the shortcomings of skin inflammation or skin irritation. Therefore, we fabricate a skin-like electrical conductive electrode via electroless silver plating on the surface of regenerated cellulose membrane, in which the cellulose membrane is obtained by the dissolution of cotton fiber with green solvent ionic liquid [Bmim]Cl. The as-prepared biocompatible electrode with low skin-electrode contact impedance can be used as a dry electrode for a long-term period of use. The impedance at 700 Hz is only 8 kΩ/cm2, and the conductivity can reach 252 s/cm. After 5 hours of wear, the skin contact impedance of the electrode was only 10 kΩ/cm2 under 700 Hz(when AgNO3 was used at a concentration of 0.20 mol/L). Importantly, the electrodes not only provide a stable and clear ECG signal, but also offer a high level of comfort and low impedance, when used for long-term health monitoring.

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

2018 ◽  
Vol 89 (11) ◽  
pp. 2098-2112 ◽  
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.

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

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.

scholarly journals Flexible Multi-Layer Semi-Dry Electrode for Scalp EEG Measurements at Hairy Sites

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 518 ◽  
Author(s):  
Haoqiang Hua ◽  
Wei Tang ◽  
Xiangmin Xu ◽  
David Dagan Feng ◽  
Lin Shu
Keyword(s):  
Temporal Correlation ◽  
Acquisition Time ◽  
Eeg Monitoring ◽  
Foam Layer ◽  
Contact Impedance ◽  
Lower Electrode ◽  
Scalp Eeg ◽  
Dry Electrodes ◽  
Dry Electrode

One of the major challenges of daily wearable electroencephalogram (EEG) monitoring is that there are rarely suitable EEG electrodes for hairy sites. Wet electrodes require conductive gels, which will dry over the acquisition time, making them unstable for long-term EEG monitoring. Additionally, the electrode–scalp impedances of most dry electrodes are not adequate for high quality EEG collection at hairy sites. In view of the above problems, a flexible multi-layer semi-dry electrode was proposed for EEG monitoring in this study. The semi-dry electrode contains a flexible electrode body layer, foam layer and reservoir layer. The probe structure of the electrode body layer enables the electrode to work effectively at hairy sites. During long-term EEG monitoring, electrolytes stored in the reservoir layer are continuously released through the foam layer to the electrode–scalp interface, ensuring a lower electrode–scalp contact impedance. The experimental results showed that the average electrode–scalp impedance of the semi-dry electrode at a hairy site was only 23.89 ± 7.44 KΩ at 10 Hz, and it was lower than 40 KΩ over a long-term use of 5 h. The electrode performed well in both static and dynamic EEG monitoring, where the temporal correlation with wet electrode signals at the hairy site could reach 94.25% and 90.65%, respectively, and specific evoked EEG signals could be collected. The flexible multi-layer semi-dry electrode can be well applied to scalp EEG monitoring at hairy sites, providing a promising solution for daily long-term monitoring of wearable EEGs.

Health Effects of Oil Mists: A Brief Review

1989 ◽  
Vol 5 (3) ◽  
pp. 429-440 ◽  
Author(s):  
Carl R. Mackerer
Keyword(s):  
Health Effects ◽  
Metal Cutting ◽  
Human Cancer ◽  
Health Effect ◽  
Skin Irritation ◽  
Cutting Fluid ◽  
Cutting Fluids ◽  
Potential Health ◽  
Skin Contact

Metal cutting/grinding fluids are of three basic types: straight oil (insoluble), oil-in-water emulsions (soluble) and synthetic/semi-synthetic. All contain a variety of additives to improve performance. Human exposure occurs primarily by direct skin contact with the liquid or by skin and respiratory contact after fluid misting. Dermatitis caused by primary or direct skin irritation is the most prevalent health effect of exposure to cutting fluids. Occasionally allergic dermatitis is seen which is related to the development of sensitization to one or more of the additive components. Recent studies indicate that long-term exposure to cutting fluids does not result in increased incidences of lung cancer, urinary bladder cancer, gastrointestinal cancer, or death from non-malignant respiratory diseases. Long-term exposure to certain cutting fluids, however, is believed to have resulted in certain types of skin cancer, especially scrotal cancer. It is likely that these carcinogenic responses were caused by contact with polycyclic aromatic compounds (PCA) of 3–7 rings. Modern base oils which are severely refined have very low levels of PCA, are not carcinogenic in animal bioassays, and are unlikely to be carcinogenic in man. This is not necessarily true for re-refined oils which may contain significant levels of PCA and polychlorinated biphenyls derived from coming-ling used cutting oils with used engine oils and transformer oils. Cutting oils, themselves, generally do not accumulate significant levels of carcinogenic PCA during use. Additives, in theory, can cause a variety of health effects either directly or through the generation of reaction products such as nitrosamines. In actual use, adverse health effects appear to be limited to occasional instances of allergic contact dermatitis. Nitrosamines are extremely carcinogenic in test animals; although no human cancer cases directly attributable to nitrosamine contamination have been observed, nitrosating agents and amines should not be combined in cutting fluid formulations. It is difficult to anticipate or predict the potential toxicity of a particular cutting fluid formulation because of the presence of variable amounts of proprietary additives which, themselves, are often complex reaction mixtures. Thus, each additive and final formulation must be evaluated on a case by case basis to appropriately assess potential health hazards.

Soft Dry Electrodes for Electrocardiogram with Conductive Silver Nanowires

2014 ◽  
Vol 1685 ◽  
Author(s):  
Amanda Myers ◽  
Yong Zhu
Keyword(s):  
Health Monitoring ◽  
Silver Chloride ◽  
Silver Nanowires ◽  
Skin Irritation ◽  
Hospital Setting ◽  
Skin Impedance ◽  
Ecg Signals ◽  
Dry Electrode ◽  
Silver Silver

ABSTRACTWith increasing attention towards long-term health monitoring, there is a pressing need to create noninvasive sensors that monitor vital bioelectronic signals. Particular importance is placed on measuring electrocardiogram (ECG) signals as heart issues are widespread and can be prevented with the proper warning and care of potential problems. Currently, ECGs are taken in a hospital setting using disposable silver-silver chloride (Ag/AgCl) pre-gelled electrodes. Unfortunately, this cannot translate to a long-term monitoring setting due to the electrolytic gel of the electrodes drying and causing skin irritation. This paper presents a soft, skin-mountable dry electrode based on silver nanowires (AgNWs) for measuring ECG signals that can be used in long-term, wearable health monitoring due to the elimination of the electrolytic gel. The AgNWs are embedded in polydimethylsiloxane (PDMS), which creates a robust design that will not suffer from delamination or cracking problems that can eventually lead to loss of conductivity. The electrode is characterized by electrode-skin impedance as a function of frequency and by the surface resistance as the electrode is stretched. The performance of the dry electrode is evaluated and comparable to that of conventional Ag/AgCl electrodes. The ability of the dry electrode to conform to skin is believed to compensate for the lack of an electrolytic gel.

scholarly journals Comparative Study on Conductive Knitted Fabric Electrodes for Long-Term Electrocardiography Monitoring: Silver-Plated and PEDOT:PSS Coated Fabrics

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3890 ◽  
Author(s):  
Amale Ankhili ◽  
Xuyuan Tao ◽  
Cédric Cochrane ◽  
Vladan Koncar ◽  
David Coulon ◽  
...  
Keyword(s):  
Female Subject ◽  
Knitted Fabric ◽  
Ecg Signal ◽  
Ecg Signals ◽  
Medical Quality ◽  
Textile Electrodes ◽  
Wide Range ◽  
Poly Styrene Sulfonate ◽  
The Right

Long-term monitoring of the electrical activity of the heart helps to detect the presence of potential dysfunctions, enabling the diagnosis of a wide range of cardiac pathologies. However, standard electrodes used for electrocardiogram (ECG) acquisition are not fully integrated into garments, and generally need to be used with a gel to improve contact resistance. This article is focused on the development of washable screen-printed cotton, with and without Lycra, textile electrodes providing a medical quality ECG signal to be used for long-term electrocardiography measurements. Several samples with different Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) concentrations were investigated. Silver-plated knitted fabric electrodes were also used for comparison, within the same process of ECG signal recording. The acquisition of ECG signals carried out by a portable medical device and a low-coast Arduino-based device on one female subject in a sitting position. Three textile electrodes were placed on the right and left forearms and a ground electrode was placed on the right ankle of a healthy female subject. Plastic clamps were applied to maintain electrodes on the skin. The results obtained with PEDOT:PSS used for electrodes fabrication have been presented, considering the optimal concentration required for medical ECG quality and capacity to sustain up to 50 washing cycles. All the ECG signals acquired and recorded, using PEDOT:PSS and silver-plated electrodes, have been reviewed by a cardiologist in order to validate their quality required for accurate diagnosis.

Preparation, Characterization and Biocompatibility of Regenerated Cellulose/PVA Blend Membranes in 1-Allyl-3-Methyimidazolium Chloride

2011 ◽  
Vol 179-180 ◽  
pp. 1108-1111 ◽  
Author(s):  
Yun Lu ◽  
Yi Xing Liu ◽  
Hai Peng Yu ◽  
Qing Feng Sun
Keyword(s):  
Ionic Liquid ◽  
Phase Separation ◽  
Polyvinyl Alcohol ◽  
Regenerated Cellulose ◽  
Cellulose Membrane ◽  
Sem Images ◽  
Pure Cellulose ◽  
Blend Membranes

Regenerated cellulose/polyvinyl alcohol (PVA) blend membranes were prepared from a solution of cellulose and PVA in an ionic liquid of 1-allyl-3-methyimidazolium chloride (AMImCl). SEM images showed that the phase separation on the mixture was severely formed when the content of PVA was higher than 10% by volume. However, when the content of PVA in the mixture was lower than 6%, the cellulose and PVA were well-distributed. The regenerated blend membranes using the AMImCl presenting reasonable crystallinity were superior to those of regenerated pure cellulose membrane. In conclusion, the compatible properties of blend membranes from regenerated cellulose/PVA (6%) were improved and the blend membranes kept original biodegradability.

scholarly journals Arm-ECG Wireless Sensor System for Wearable Long-Term Surveillance of Heart Arrhythmias

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1300 ◽  
Author(s):  
Angel Villegas ◽  
David McEneaney ◽  
Omar Escalona
Keyword(s):  
Performance Assessment ◽  
Heart Rhythm ◽  
Sensor System ◽  
Ecg Signal ◽  
Far Field ◽  
Predictive Values ◽  
Dry Electrode ◽  
Prototype Device ◽  
Assessment Results

This article presents the devising, development, prototyping and assessment of a wearable arm-ECG sensor system (WAMECG1) for long-term non-invasive heart rhythm monitoring, and functionalities for acquiring, storing, visualizing and transmitting high-quality far-field electrocardiographic signals. The system integrates the main building blocks present in a typical ECG monitoring device such as the skin surface electrodes, front-end amplifiers, analog and digital signal conditioning filters, flash memory and wireless communication capability. These are integrated into a comfortable, easy to wear, and ergonomically designed arm-band ECG sensor system which can acquire a bipolar ECG signal from the upper arm of the user over a period of 72 h. The small-amplitude bipolar arm-ECG signal is sensed by a reusable, long-lasting, Ag–AgCl based dry electrode pair, then digitized using a programmable sampling rate in the range of 125 to 500 Hz and transmitted via Wi-Fi. The prototype comparative performance assessment results showed a cross-correlation value of 99.7% and an error of less than 0.75% when compared to a reference high-resolution medical-grade ECG system. Also, the quality of the recorded far-field bipolar arm-ECG signal was validated in a pilot trial with volunteer subjects from within the research team, by wearing the prototype device while: (a) resting in a chair; and (b) doing minor physical activities. The R-peak detection average sensibilities were 99.66% and 94.64%, while the positive predictive values achieved 99.1% and 92.68%, respectively. Without using any additional algorithm for signal enhancement, the average signal-to-noise ratio (SNR) values were 21.71 and 18.25 for physical activity conditions (a) and (b) respectively. Therefore, the performance assessment results suggest that the wearable arm-band prototype device is a suitable, self-contained, unobtrusive platform for comfortable cardiac electrical activity and heart rhythm logging and monitoring.

Multifunctional Skin-Like Electronics for Long-Term Health Monitoring

2012 ◽  
Author(s):  
Woon-Hong Yeo ◽  
Yun-Soung Kim ◽  
Jongwoo Lee ◽  
John A. Rogers
Keyword(s):  
Health Monitoring ◽  
Skin Irritation ◽  
Electronic System ◽  
Metal Electrode ◽  
Skin Surface ◽  
Quality Data ◽  
Contact Impedance ◽  
Skin Preparation ◽  
Wireless Data Acquisition

Conductive gel-based wet electrodes along with the skin preparation have been widely used for the measurement of electrophysiological signals on the skin in a health monitoring system. The use of conductive gels is necessary to reduce the contact impedance between the skin surface and electrode. However, it can cause skin irritation or allergic reactions. This issue originates from the mismatch between the soft, curvy skin epidermis and the rigid, flat metal electrode. To address the issues of conventional electronics, we introduce a new class of ‘skin-like’ electronic system. The electronics can be conformally laminated on the epidermis, such that it ensures high-quality data recording without conductive gels. The skin-like electronics incorporates electrophysiological-, temperature-, and strain sensors in the system for multimodal functionality. To provide robust wearability for a week, a medical spray bandage is utilized to shield the sensor on the skin. The multifunctional sensor measures physiological signals and they are recorded with a commercial wireless data acquisition system along with a releasable, skin-like connector. This novel, multifunctional electronics on the skin can potentially replace the irritable and cumbersome wet electrodes for portable, long-term health monitoring at home.

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