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

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.

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

Biosensors ◽

10.3390/bios11040101 ◽

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.

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Two Electrode ECG And EOG System For Monitoring Applications

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k1315.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 262-265

Keyword(s):

Reference Electrode ◽

Cost Effective ◽

Electrode System ◽

Ecg Signal ◽

Biomedical Signal ◽

Ecg Signals ◽

Arm Position ◽

The Stability ◽

Electrocardiogram Ecg ◽

Total Gain

Heart and Eye are two vital organs in the human system. By knowing the Electrocardiogram (ECG) and Electro-oculogram (EOG), one will be able to tell the stability of the heart and eye respectively. In this project, we have developed a circuit to pick the ECG and EOG signal using two wet electrodes. Here no reference electrode is used. EOG and ECG signals have been acquired from ten healthy subjects. The ECG signal is obtained from two positions, namely wrist and arm position respectively. The picked-up biomedical signal is recorded and heart rate information is extracted from ECG signal using the biomedical workbench. The result found to be promising and acquired stable EOG and ECG signal from the subjects. The total gain required for the arm position is higher than the wrist position for the ECG signal. The total gain necessary for the EOG signal is higher than the ECG signal since the ECG signal is in the range of millivolts whereas EOG signal in the range of microvolts. This two-electrode system is stable, cost-effective and portable while still maintaining high common-mode rejection ratio (CMRR).

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Improving electrocorticograms of awake and anaesthetized mice using wavelet denoising

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2018-0112 ◽

2018 ◽

Vol 4 (1) ◽

pp. 469-472 ◽

Cited By ~ 1

Author(s):

Michael Schweigmann ◽

Klaus Peter Koch ◽

Fabian Auler ◽

Frank Kirchhoff

Keyword(s):

Signal To Noise Ratio ◽

Wavelet Denoising ◽

Functional Evaluation ◽

Electrode Impedance ◽

Electrode Arrays ◽

Brain Surface ◽

Micro Electrode Arrays ◽

Cellular Circuits ◽

Noise Models

AbstractThe quality of bioelectrical signals is essential for functional evaluation of cellular circuits. The electrical activity recorded from the cortical brain surface represents the average of many individual synaptic processes. By downsizing micro-electrode arrays, the spatial resolution of electrocortico-grams (ECoGs) can be increased. But, upon increasing electrode impedance, recorded noise from the electrode-tissue interface and the surroundings will become more prominent. Frequently, signal interpretation is improved by post-processing using filtering or pattern recognition. For a variety of applications, wavelet denoising has become an accepted tool. Here, we present how wavelet denoising affects the signal-to-noise ratio of ECoGs. The recording qualities from awake and anesthetized mice was artificially reduced by adding two noise models prior to filtering. Raw and filtered signals were compared by calculating the linear correlation coefficient.

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TWO-LEAD JOINT DETECTION ALGORITHM OF QRS COMPLEXES IN ECG SIGNAL

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519421400728 ◽

2021 ◽

Author(s):

WANSONG XU ◽

TIANWU CHEN ◽

FANYU DU

Keyword(s):

Detection Algorithm ◽

Detection Accuracy ◽

Ecg Signal ◽

Joint Detection ◽

Ecg Signals ◽

Detection Algorithms ◽

Threshold Adjustment ◽

Current Algorithm ◽

Electrocardiogram Ecg

Objective: The detection of QRS complexes is an important part of computer-aided analysis of electrocardiogram (ECG). However, most of the existing detection algorithms are mainly for single-lead ECG signals, which requires high quality of signal. If the signal quality decreases suddenly due to some interference, then the current algorithm is easy to cause misjudgment or missed detection. To improve the detection ability of QRS complexes under sudden interference, we study the QRS complexes information on multiple leads in-depth, and propose a two-lead joint detection algorithm of QRS complexes. Methods: Firstly, the suspected QRS complexes are screened on the main lead. For the suspected QRS complexes with low confidence and the complexes that may be missed, further accurate detection and joint judgment shall be carried out at the corresponding position of the auxiliary lead. At the same time, the adaptive threshold adjustment algorithm and backtracking mechanism are used to modify the detection results. Results: The proposed detection algorithm is validated using 48 ECG records of the MIT-BIH arrhythmia database, and achieves average detection accuracy of 99.71%, sensitivity of 99.88% and positive predictivity of 99.81%. Conclusion: The proposed algorithm has high accuracy, which can effectively deal with the sudden interference of ECG signal. Meanwhile, the algorithm requires small amount of computation, and can be embedded into hardware for real-time detection.

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

10.21203/rs.3.rs-1223238/v1 ◽

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.

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Electrocardiogram Baseline Wander Suppression Based on the Combination of Morphological and Wavelet Transformation Based Filtering

Computational and Mathematical Methods in Medicine ◽

10.1155/2019/7196156 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 20

Author(s):

Xiang-kui Wan ◽

Haibo Wu ◽

Fei Qiao ◽

Feng-cong Li ◽

Yan Li ◽

...

Keyword(s):

Realistic Model ◽

Suppression Effect ◽

Ecg Signals ◽

Morphological Filtering ◽

Baseline Wander ◽

Waveform Distortions ◽

Electrocardiogram Ecg ◽

Morphology Filter ◽

Better Than

One of the major noise components in electrocardiogram (ECG) is the baseline wander (BW). Effective methods for suppressing BW include the wavelet-based (WT) and the mathematical morphological filtering-based (MMF) algorithms. However, the T waveform distortions introduced by the WT and the rectangular/trapezoidal distortions introduced by MMF degrade the quality of the output signal. Hence, in this study, we introduce a method by combining the MMF and WT to overcome the shortcomings of both existing methods. To demonstrate the effectiveness of the proposed method, artificial ECG signals containing a clinical BW are used for numerical simulation, and we also create a realistic model of baseline wander to compare the proposed method with other state-of-the-art methods commonly used in the literature. The results show that the BW suppression effect of the proposed method is better than that of the others. Also, the new method is capable of preserving the outline of the BW and avoiding waveform distortions caused by the morphology filter, thereby obtaining an enhanced quality of ECG.

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A Pipeline for Adaptive Filtering and Transformation of Noisy Left-Arm ECG to Its Surrogate Chest Signal

Electronics ◽

10.3390/electronics9050866 ◽

2020 ◽

Vol 9 (5) ◽

pp. 866

Author(s):

Farzad Mohaddes ◽

Rafael da Silva ◽

Fatma Akbulut ◽

Yilu Zhou ◽

Akhilesh Tanneeru ◽

...

Keyword(s):

Adaptive Filtering ◽

Mean Squared Error ◽

Signal To Noise Ratio ◽

Recursive Least Squares ◽

Step Size ◽

Ecg Signals ◽

Squared Error ◽

One Step ◽

Power Line Interference ◽

Electrocardiogram Ecg

The performance of a low-power single-lead armband in generating electrocardiogram (ECG) signals from the chest and left arm was validated against a BIOPAC MP160 benchtop system in real-time. The filtering performance of three adaptive filtering algorithms, namely least mean squares (LMS), recursive least squares (RLS), and extended kernel RLS (EKRLS) in removing white (W), power line interference (PLI), electrode movement (EM), muscle artifact (MA), and baseline wandering (BLW) noises from the chest and left-arm ECG was evaluated with respect to the mean squared error (MSE). Filter parameters of the used algorithms were adjusted to ensure optimal filtering performance. LMS was found to be the most effective adaptive filtering algorithm in removing all noises with minimum MSE. However, for removing PLI with a maximal signal-to-noise ratio (SNR), RLS showed lower MSE values than LMS when the step size was set to 1 × 10−5. We proposed a transformation framework to convert the denoised left-arm and chest ECG signals to their low-MSE and high-SNR surrogate chest signals. With wide applications in wearable technologies, the proposed pipeline was found to be capable of establishing a baseline for comparing left-arm signals with original chest signals, getting one step closer to making use of the left-arm ECG in clinical cardiac evaluations.

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Nearly Reversible ECG Steganography based on Polar Coordinate System with Digital Replacement Technique

Transactions on Machine Learning and Artificial Intelligence ◽

10.14738/tmlai.96.11177 ◽

2021 ◽

Vol 9 (6) ◽

pp. 9-19

Author(s):

CHING YU YANG ◽

Chi-Kai Huang

Keyword(s):

Coordinate System ◽

Signal To Noise Ratio ◽

Personal Data ◽

Polar Coordinate System ◽

Measuring Instruments ◽

Replacement Technique ◽

Polar Coordinate ◽

Electrocardiogram Ecg ◽

High Payload

In this paper, we present a nearly reversible data hiding for electrocardiogram (ECG) hosts. Based on the polar coordinate system domain, medical diagnosis and personal data can be embedded in an ECG signal by the simple digital replacement technique. Simulations revealed that the restored ECG with near lossless quality can be obtained by the proposed method at receiver site. In addition, the perceived quality of the marked ECG is very good with a high payload size. Moreover, the resultant signal-to-noise ratio (SNR), peak SNR, and payload of the proposed method outperforms those of existing techniques. Since the computation cost is low, the proposed method can be used in portable biometrics or ECG measuring instruments.

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An Effective LSTM Recurrent Network to Detect Arrhythmia on Imbalanced ECG Dataset

Journal of Healthcare Engineering ◽

10.1155/2019/6320651 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 12

Author(s):

Junli Gao ◽

Hongpo Zhang ◽

Peng Lu ◽

Zongmin Wang

Keyword(s):

Short Term Memory ◽

Recurrent Network ◽

Short Term ◽

Ecg Signals ◽

Beat Classification ◽

Long Short Term Memory ◽

Lstm Network ◽

Reliable Solution ◽

Electrocardiogram Ecg

To reduce the high mortality rate from cardiovascular disease (CVD), the electrocardiogram (ECG) beat plays a significant role in computer-aided arrhythmia diagnosis systems. However, the complex variations and imbalance of ECG beats make this a challenging issue. Since ECG beat data exist in heavily imbalanced category, an effective long short-term memory (LSTM) recurrence network model with focal loss (FL) is proposed. For this purpose, the LSTM network can disentangle the timing features in complex ECG signals, while the FL is used to resolve the category imbalance by downweighting easily identified normal ECG examples. The advantages of the proposed network have been verified in the MIT-BIH arrhythmia database. Experimental results show that the LSTM network with FL achieved a reliable solution to the problem of imbalanced datasets in ECG beat classification and was not sensitive to quality of ECG signals. The proposed method can be deployed in telemedicine scenarios to assist cardiologists into more accurately and objectively diagnosing ECG signals.

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Development of medical capacitive coupling electrodes using the skin-electrode contact control

Sensor Review ◽

10.1108/sr-11-2019-0289 ◽

2020 ◽

Vol 40 (3) ◽

pp. 347-354

Author(s):

Gennadiy Evtushenko ◽

Inna A. Lezhnina ◽

Artem I. Morenetz ◽

Boris N. Pavlenko ◽

Arman A. Boyakhchyan ◽

...

Keyword(s):

Personalized Medicine ◽

The Body ◽

Capacitive Coupling ◽

Ecg Signal ◽

Significant Deterioration ◽

Content Type ◽

Ecg Signals ◽

Skin Electrode ◽

Electrode Contact

Purpose The purpose of this paper is the development and study of capacitive coupling electrodes with the ability to monitor the quality of the skin–electrode contact in the process of electrocardiogram (ECG) diagnostics. The study’s scope embraces experimental identification of distortions contributed into the recorded ECG signal at various degrees of disturbance of the skin–electrode contact. Design/methodology/approach A capacitive coupling electrode is designed and manufactured. A large number of experiments was carried out to record ECG signals with different quality of the skin–electrode contact. Using spectral analysis, the characteristic distortions of the ECG signals in the event of contact disturbance are revealed. Findings It was found that the violation of the skin–electrode contact leads to significant deterioration in the recorded signal. In this case, the most severe distortions appear with various violations of the skin–electrode contact of two sensors in one lead. It has been experimentally shown that the developed sensor allows monitoring the quality of the contact, and therefore, improvement of the quality of signal registration, enabled by the use of bespoke processing algorithms. Practical implications These sensors will be used in personalized medicine devices and tele-ECG devices. Originality/value In this work, authors studied the effect of the skin–electrode contact of a capacitive electrode with the body on the quality of the recorded ECG signal. Based on the studies, the necessity of monitoring contact was shown to improve the quality of diagnostics provided by personalized medicine devices; the capacitive sensor with contact feedback was developed.

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