scholarly journals A Novel Wearable Flexible Dry Electrode Based on Cowhide for ECG Measurement

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 101
Author(s):  
Yiping Huang ◽  
Yatong Song ◽  
Li Gou ◽  
Yuanwen Zou
Keyword(s):  
Signal To Noise Ratio ◽  
Equivalent Circuit Model ◽  
Electrode Impedance ◽  
Skin Electrode ◽  
Fitting Method ◽  
Dry Electrode ◽  
Input Waveform ◽  
Electrode Interface ◽  
Silver Electrodes ◽  
Electrocardiogram Ecg

The electrocardiogram (ECG) electrode, as a sensor, is an important part of the wearable ECG monitoring device. Natural leather is rarely used as the electrode substrate. In this paper, wearable flexible silver electrodes based on cowhide were prepared by sputtering and brush-painting. A signal generator, oscilloscope, impedance test instrument, and ECG monitor were used to build the test platform evaluating the performance of electrodes with six subjects. The lossless waveform transmission can be achieved with our electrodes. Therefore, the Pearson’s correlation coefficient calculated with input waveform and output waveform of the electrodes based on the top grain layer (GLE) and the split layer (SLE) of cowhide were 0.997 and 0.998 at 0.1 Hz respectively. The skin electrode impedance (Z) was tested, and the parameters of the equivalent circuit model of the skin electrode interface were calculated by a fitting method, indicating that the Z of the prepared electrodes was comparable with the standard gel electrode when the skin is moist enough. The signal-to-noise ratio of the ECG of the GLE and the SLE were 1.148 and 1.205 times that of the standard electrode in the standing posture, which meant the ECG measured by our electrodes was basically consistent with that measured by the standard electrode.

scholarly journals Performance Evaluation of Plain Weave and Honeycomb Weave Electrodes for Human ECG Monitoring

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xueliang Xiao ◽  
Sandeep Pirbhulal ◽  
Ke Dong ◽  
Wanqing Wu ◽  
Xi Mei
Keyword(s):  
Signal To Noise Ratio ◽  
Reference Electrode ◽  
Electrode Impedance ◽  
Ecg Signals ◽  
Skin Electrode ◽  
Transfer Unit ◽  
Long Time ◽  
Innovative Materials ◽  
Electrocardiogram Ecg

Long-time monitoring of physiological parameters can scrutinize human health conditions so as to use electrocardiogram (ECG) for diagnosis of some human’s chronic cardiovascular diseases. The continuous monitoring requires the wearable electrodes to be breathable, flexible, biocompatible, and skin-affinity friendly. Weave electrodes are innovative materials to supply these potential performances. In this paper, four conductive weave electrodes in plain and honeycomb weave patterns were developed to monitor human ECG signals. A wearable belt platform was developed to mount such electrodes for acquisition of ECG signals using a back-end electronic circuit and a signal transfer unit. The performance of weave ECG electrodes was evaluated in terms of skin-electrode contacting impedance, comfortability, ECG electrical characteristics, and signal fidelity. Such performances were then compared with the values from Ag/AgCl reference electrode. The test results showed that lower skin-electrode impedance, higher R-peak amplitude, and signal-to-noise ratio (SNR) value were obtained with the increased density of conductive filaments in weave and honeycomb weave electrode presented higher comfort but poorer signal quality of ECG. This study inspires an acceptable way of weave electrodes in long- and real-time of human biosignal monitoring.

scholarly journals Time Evolution of the Skin–Electrode Interface Impedance under Different Skin Treatments

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5210
Author(s):  
Brendan B. Murphy ◽  
Brittany H. Scheid ◽  
Quincy Hendricks ◽  
Nicholas V. Apollo ◽  
Brian Litt ◽  
...  
Keyword(s):  
Equivalent Circuit Model ◽  
Complex Nature ◽  
Electrode Impedance ◽  
Modeling Framework ◽  
Modest Improvement ◽  
Interface Impedance ◽  
Mechanical Abrasion ◽  
Skin Electrode ◽  
Electrode Interface

A low and stable impedance at the skin–electrode interface is key to high-fidelity acquisition of biosignals, both acutely and in the long term. However, recording quality is highly variable due to the complex nature of human skin. Here, we present an experimental and modeling framework to investigate the interfacial impedance behavior, and describe how skin interventions affect its stability over time. To illustrate this approach, we report experimental measurements on the skin–electrode impedance using pre-gelled, clinical-grade electrodes in healthy human subjects recorded over 24 h following four skin treatments: (i) mechanical abrasion, (ii) chemical exfoliation, (iii) microporation, and (iv) no treatment. In the immediate post-treatment period, mechanical abrasion yields the lowest initial impedance, whereas the other treatments provide modest improvement compared to untreated skin. After 24 h, however, the impedance becomes more uniform across all groups (<20 kΩ at 10 Hz). The impedance data are fitted with an equivalent circuit model of the complete skin–electrode interface, clearly identifying skin-level versus electrode-level contributions to the overall impedance. Using this model, we systematically investigate how time and treatment affect the impedance response, and show that removal of the superficial epidermal layers is essential to achieving a low, long-term stable interface impedance.

scholarly journals A Long-Term, Portable ECG Patch Monitor Based on Flexible Dry Electrode

2022 ◽  
Author(s):  
Hao Chu ◽  
Chenxi Yang ◽  
Yantao Xing ◽  
Jianqing Li ◽  
Chengyu Liu
Keyword(s):  
Electrode Impedance ◽  
Ecg Monitoring ◽  
High Quality ◽  
Ecg Signals ◽  
Skin Electrode ◽  
Rr Interval ◽  
Dry Electrodes ◽  
Dry Electrode ◽  
And Storage

Abstract PurposeLong-term electrocardiogram (ECG) monitoring is an essential approach for the early diagnosis of cardiovascular diseases. Flexible dry electrodes that contains electrolyte without water could be a potential substitution of wet electrodes for long-term ECG monitoring. Therefore, this paper developes a long-term, portable ECG patch based on flexible dry electrodes, namely SEUECG-100.MethodA device consists of analog-front-end acquisition, data acquisition, and storage modules is developed and tested. An impedance test was conducted to compare the skin-electrode impedance of the flexible dry electrode and the Ag/AgCl wet electrode. The ECG signals were simutanously collected from the same subject using the SEUECG-100 and Shimmer device , which were then compared and analyzed from the perspective of ECG morphology, RR interval, and signal quality indices (SQI).ResultsThe experimental results reveal that the flexible dry electrode has the characteristics of low skin-electrode impedance. SEUECG-100 could collect high-quality ECG signals. The ECG signals collected by the two devices have a high RR interval correlation (r=0.999). SQI results show that SEUECG-100 is better than the Shimmer device in overcoming baseline drift. Long-term ECG acquisition and storage experiments show that SEUECG-100 could collect ECG signals with good stability and high reliability.ConclusionThe implementation of the proposed system design with dry electrodes could can effectively record long-term ECG monitoring with high quality in comparison to systems with wet electrodes from both impedance characteristics and signal morphology aspects.

scholarly journals Validating Poly(3,4-ethylene dioxythiophene) Polystyrene Sulfonate-Based Textile Electroencephalography Electrodes by a Textile-Based Head Phantom

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3629
Author(s):  
Granch Berhe Tseghai ◽  
Benny Malengier ◽  
Kinde Anlay Fante ◽  
Lieva Van Langenhove
Keyword(s):  
Signal To Noise Ratio ◽  
Brain Activity ◽  
Human Mind ◽  
Electrode Impedance ◽  
Polystyrene Sulfonate ◽  
Dry Electrodes ◽  
Dry Electrode ◽  
Potential Alternative ◽  
Spectral Perturbation ◽  
Coated Cotton

It is important to go through a validation process when developing new electroencephalography (EEG) electrodes, but it is impossible to keep the human mind constant, making the process difficult. It is also very difficult to identify noise and signals as the input signal is unknown. In this work, we have validated textile-based EEG electrodes constructed from a poly(3,4-ethylene dioxythiophene) polystyrene sulfonate:/polydimethylsiloxane coated cotton fabric using a textile-based head phantom. The performance of the textile-based electrode has also been compared against a commercial dry electrode. The textile electrodes collected a signal to a smaller skin-to-electrode impedance (−18.9%) and a higher signal-to-noise ratio (+3.45%) than Ag/AgCl dry electrodes. From an EEGLAB, it was observed that the inter-trial coherence and event-related spectral perturbation graphs of the textile-based electrodes were identical to the Ag/AgCl electrodes. Thus, these textile-based electrodes can be a potential alternative to monitor brain activity.

scholarly journals Electrode for Wearable Electrotherapy

Proceedings ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 5
Author(s):  
Meijing Liu ◽  
Steve Beeby ◽  
Kai Yang
Keyword(s):  
Silicone Rubber ◽  
Electrode Impedance ◽  
The Novel ◽  
Resistivity Change ◽  
Stencil Printing ◽  
Current Frequency ◽  
Skin Electrode ◽  
Dry Electrode

An electrode is a fundamental element used in many electrotherapy devices. This work presents a novel dry electrode made from carbon and silicone rubber materials for wearable electrotherapy applications. The electrode was mixed using a speed mixer and fabricated using stencil printing. This paper investigates the resistivity change of the electrode under the pressure from 0 mmHg to 32.4 mmHg; and the skin–electrode impendence with the current frequency from 20 Hz to 10,000 Hz. The resistivity of the novel dry electrode is 24.6 ± 1.5 Ω∙m when the pressure on electrode is 17.7 mmHg. The skin–electrode impedance reduced from 1001.6 Ω to 145.3 Ω when the frequency increased from 20 Hz to 10,000 Hz.

scholarly journals Evaluation of dry textile electrodes for long-term electrocardiographic monitoring

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Milad Alizadeh-Meghrazi ◽  
Binbin Ying ◽  
Alessandra Schlums ◽  
Emily Lam ◽  
Ladan Eskandarian ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Performance Metrics ◽  
Evaluation Procedure ◽  
Electrode Impedance ◽  
Ecg Signals ◽  
Skin Electrode ◽  
Electrocardiographic Monitoring ◽  
Textile Electrodes ◽  
Dry Electrode

Abstract Background Continuous long-term electrocardiography monitoring has been increasingly recognized for early diagnosis and management of different types of cardiovascular diseases. To find an alternative to Ag/AgCl gel electrodes that are improper for this application scenario, many efforts have been undertaken to develop novel flexible dry textile electrodes integrated into the everyday garments. With significant progresses made to address the potential issues (e.g., low signal-to-noise ratio, high skin–electrode impedance, motion artifact, and low durability), the lack of standard evaluation procedure hinders the further development of dry electrodes (mainly the design and optimization). Results A standard testing procedure and framework for skin–electrode impedance measurement is demonstrated for the development of novel dry textile electrodes. Different representative electrode materials have been screen-printed on textile substrates. To verify the performance of dry textile electrodes, impedance measurements are conducted on an agar skin model using a universal setup with consistent frequency and pressure. In addition, they are demonstrated for ECG signals acquisition, in comparison to those obtained using conventional gel electrodes. Conclusions Dry textile electrodes demonstrated similar impedance when in raised or flat structures. The tested pressure variations had an insignificant impact on electrode impedance. Looking at the effect of impedance on ECG signals, a noticeable effect on ECG signal performance metrics was not observed. Therefore, it is suggested that impedance alone is possibly not the primary indicator of signal quality. As well, the developed methods can also serve as useful guidelines for future textile dry-electrode design and testing for practical ECG monitoring applications.

scholarly journals Fabric Vest Socket with Embroidered Electrodes for Control of Myoelectric Prosthesis

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1196 ◽  
Author(s):  
Seulah Lee ◽  
Babar Jamil ◽  
Sunhong Kim ◽  
Youngjin Choi
Keyword(s):  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Electrode Impedance ◽  
Rigid Support ◽  
Daily Lives ◽  
Myoelectric Prosthesis ◽  
Myoelectric Prostheses ◽  
Average Classification Accuracy ◽  
High Level ◽  
Semg Signals

Myoelectric prostheses assist users to live their daily lives. However, the majority of users are primarily confined to forearm amputees because the surface electromyography (sEMG) that understands the motion intents should be acquired from a residual limb for control of the myoelectric prosthesis. This study proposes a novel fabric vest socket that includes embroidered electrodes suitable for a high-level upper amputee, especially for shoulder disarticulation. The fabric vest socket consists of rigid support and a fabric vest with embroidered electrodes. Several experiments were conducted to verify the practicality of the developed vest socket with embroidered electrodes. The sEMG signals were measured using commercial Ag/AgCl electrodes for a comparison to verify the performance of the embroidered electrodes in terms of signal amplitudes, the skin-electrode impedance, and signal-to-noise ratio (SNR). These results showed that the embroidered electrodes were as effective as the commercial electrodes. Then, posture classification was carried out by able-bodied subjects for the usability of the developed vest socket. The average classification accuracy for each subject reached 97.92%, and for all the subjects it was 93.2%. In other words, the fabric vest socket with the embroidered electrodes could measure sEMG signals with high accuracy. Therefore, it is expected that it can be readily worn by high-level amputees to control their myoelectric prostheses, as well as it is cost effective for fabrication as compared with the traditional socket.

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