Non-contact ECG Research Articles

A Noncontact ECG Sensing System With a Micropower, Ultrahigh Impedance Front-End, and BLE Connectivity

A Noncontact ECG Sensing System With a Micropower, Ultrahigh Impedance Front-End, and BLE Connectivity

RadarNet: Noncontact ECG Signal Measurement Based on FMCW Radar

RadarNet: Noncontact ECG Signal Measurement Based on FMCW Radar

Reduction in the Motion Artifacts in Noncontact ECG Measurements Using a Novel Designed Electrode Structure.

A noncontact ECG is applicable to wearable bioelectricity acquisition because it can provide more comfort to the patient for long-term monitoring. However, the motion artifact is a significant source of noise in an ECG recording. Adaptive noise reduction is highly effective in suppressing motion artifact, usually through the use of external sensors, thus increasing the design complexity and cost. In this paper, a novel ECG electrode structure is designed to collect ECG data and reference data simultaneously. Combined with the adaptive filter, it effectively suppresses the motion artifact in the ECG acquisition. This method adds one more signal acquisition channel based on the single-channel ECG acquisition system to acquire the reference signal without introducing other sensors. Firstly, the design of the novel ECG electrode structure is introduced based on the principle of noise reduction. Secondly, a multichannel signal acquisition circuit system and ECG electrodes are implemented. Finally, experiments under normal walking conditions are carried out, and the performance is verified by the experiment results, which shows that the proposed design effectively suppresses motion artifacts and maintains the stability of the signal quality during the noncontact ECG acquisition. The signal-to-noise ratio of the ECG signal after noise reduction is 14 dB higher than that of the original ECG signal with the motion artifact.

Effect of Cotton Fabric Moisture Regain and Thickness on Signal Quality of Noncontact Capacitive Coupling ECG

Non-contact capacitive coupling ECG (cECG) is considered to have a broad application prospect for its comfort and non-invasive. As an important part of cECG transmission path, the characteristics of dielectric materials significantly affect the signal quality. This paper studies the influence on the dielectric properties of coupling capacitance, human body-electrode impedance, and cECG signal quality from the perspectives of cotton fabric humidity and thickness and gives suggestions on the application of cECG. Firstly, the effects of fabric humidity and thickness on human body-electrode impedance are analyzed theoretically. Then the human body-electrode impedance and cECG signal quality index (SQI) are recorded and calculated to evaluate how thickness and humidity affect the sensing performance of cECG. The results show that influenced by the fabric thickness and humidity, the impedance values reveal observable changes varying from 5.6 GΩ (thickness: 1.00 mm, moisture regain 3.2%) to 50.4 MΩ (thickness: 0.18mm, moisture regain 23.2%) at 0.5 Hz, and the impedance change will cause the impedance mismatch between the two electrodes, resulting in poor signal quality. According to the trend of SQI, the recommended moisture regain under different thicknesses is given. When the fabric thickness is 0.18 mm, 0.35 mm, and 1.00 mm, the moisture regain should be higher than 8.5%, 14.6%, and 23.2%, respectively so as to obtain a relatively high-quality cECG signal. The design parameters discussed in this paper could provide a supporting evidence for the design of efficient non-contact cECG systems in the future.

ECG signal monitoring based on Covid-19 patients: Overview

ECG signal monitoring is a very important step for patients. Especially for those infected by covid-19. This pandemic has shown that the use of artificial intelligence helps to control the propagation of this virus. Particularly the high spread of this virus influences the number of the infected population. As well as the fact that this virus attacks the respiratory system which influences the cardiac system. Therefore, an ECG signal monitoring is mandatory. Our work presents an overview based on various approaches developed for ECG signal monitoring. These techniques are based on non-contact monitoring approaches. These approaches will help to avoid frequent contact with patients and doctors. As well as non-contact ECG signal monitoring is based on low-cost techniques, which reduces the price compared to other sensors. After the revision, we can conclude that the most suitable solution for heart rate monitoring is based on image processing using RGB cameras. These solutions are accurate, low cost, and protect the doctors.

About Non-Contact ECG Recording Devices

Modern electrocardiography research admits that periodic ECG recording (once a half year) is not effective for early diagnosing coronary artery disease, a heart attack, and sudden cardiac death..

Evaluation of a Multichannel Non-Contact ECG System and Signal Quality Algorithms for Sleep Apnea Detection and Monitoring.

Sleep-related conditions require high-cost and low-comfort diagnosis at the hospital during one night or longer. To overcome this situation, this work aims to evaluate an unobtrusive monitoring technique for sleep apnea. This paper presents, for the first time, the evaluation of contactless capacitively-coupled electrocardiography (ccECG) signals for the extraction of sleep apnea features, together with a comparison of different signal quality indicators. A multichannel ccECG system is used to collect signals from 15 subjects in a sleep environment from different positions. Reference quality labels were assigned for every 30-s segment. Quality indicators were calculated, and their signal classification performance was evaluated. Features for the detection of sleep apnea were extracted from capacitive and reference signals. Sleep apnea features related to heart rate and heart rate variability achieved high similarity to the reference values, with p-values of 0.94 and 0.98, which is in line with the more than 95% beat-matching obtained. Features related to signal morphology presented lower similarity with the reference, although signal similarity metrics of correlation and coherence were relatively high. Quality-based automatic classification of the signals had a maximum accuracy of 91%. Best-performing quality indicators were based on template correlation and beat-detection. Results suggest that using unobtrusive cardiac signals for the automatic detection of sleep apnea can achieve similar performance as contact signals, and indicates clinical value of ccECG. Moreover, signal segments can automatically be classified by the proposed quality metrics as a pre-processing step. Including contactless respiration signals is likely to improve the performance and provide a complete unobtrusive cardiorespiratory monitoring solution; this is a promising alternative that will allow the screening of more patients with higher comfort, for a longer time, and at a reduced cost.

Development of the Non-contact ECG Electrode

We designed a non-contact electrode on the basis of the capacitance coupling principle, it can be used for physiological signal acquisition, it uses dynamic shielding and electrode active driving technology to improve the quality of the signal. Experiments use this electrode to structure the ECG signal acquisition system, the ECG signal were collected with non-contact electrodes, comparing with traditional wet electrodes, the results show that noncontact electrodes developed in this paper can effectively meet the needs of ECG signal acquisition.

Development of a Novel Noncontact ECG Electrode by MEMS Fabrication Process

Development of a Novel Noncontact ECG Electrode by MEMS Fabrication Process

Letter to the Editor “On the Feasibility of Noncontact ECG Measurements”

The article by Kranjec et al. [1] , “Novel methods of noncontact heart rate measurement: A feasibility study” is interesting and informative as it compares different contactless methods for heart rate detection. Nevertheless, the use of the term “capacitively coupled ECG” (CCECG) in the article is confusing and may mislead readers.

A Hygroscopic Sensor Electrode for Fast Stabilized Non-Contact ECG Signal Acquisition.

A capacitive electrocardiography (cECG) technique using a non-invasive ECG measuring technology that does not require direct contact between the sensor and the skin has attracted much interest. The system encounters several challenges when the sensor electrode and subject’s skin are weakly coupled. Because there is no direct physical contact between the subject and any grounding point, there is no discharge path for the built-up electrostatic charge. Subsequently, the electrostatic charge build-up can temporarily contaminate the ECG signal from being clearly visible; a stabilization period (3–15 min) is required for the measurement of a clean, stable ECG signal at low humidity levels (below 55% relative humidity). Therefore, to obtain a clear ECG signal without noise and to reduce the ECG signal stabilization time to within 2 min in a dry ambient environment, we have developed a fabric electrode with embedded polymer (FEEP). The designed hygroscopic FEEP has an embedded superabsorbent polymer layer. The principle of FEEP as a conductive electrode is to provide humidity to the capacitive coupling to ensure strong coupling and to allow for the measurement of a stable, clear biomedical signal. The evaluation results show that hygroscopic FEEP is capable of rapidly measuring high-accuracy ECG signals with a higher SNR ratio.

Design and Implementation of a High Integrated Noncontact ECG Monitoring Belt

The ECG plays a key role in the rapid diagnosis of heart diseases such as coronary heart disease, ischemic heart disease, myocardial infarction, arrhythmias, etc. Unfortunately, the adhesion of conventional electrodes to the skin sometimes is difficult if not impossible due to the wet skin caused by higher perspiration. Besides, for the application of long term ECG monitoring, the wet adhesive ECG electrodes are easy to cause infection of the wearers’ skin. Moreover, in certain situations it is difficult or simply too time-consuming to undress the patient for an ECG. Therefore, novel ECG monitoring techniques are urgently needed. In this paper, an easy-to-use noncontact ECG (NCECG) monitoring node for wireless body sensor network was designed and tested. The NCECG node introduced in this paper use the doubled shielded active ECG electrodes, compared with many other two electrodes noncontact ECG monitoring node, it also added a right-leg-drive circuit to reduce the common mode noise. The experiment result shows that it could accurately monitor the ECG signals while insulated by one layer of clothes. Furthermore, the NCECG monitoring node we proposed is high compact and easy to use. Besides ECG monitoring function, it also integrates with temperature, respiration and motion state monitoring function, while the size of the circuit board is just 93 40 mm. And the elastic belt architecture makes the ECG monitoring much more convenient and easy to use.

A Reliable Non-Contact ECG Measurement System with Minimal Power Line Disturbance

A Reliable Non-Contact ECG Measurement System with Minimal Power Line Disturbance

Noncontact ECG recording system with real time capacitance measurement for motion artifact reduction.

A system for noncontact ECG recording is proposed that measures the real time electrode-body capacitance concurrently with the ECG as a reference signal for motion artifact reduction. Simultaneous recordings of these two signals from the human body in the presence of electrode motion artifacts are shown and an adaptive least-mean-squares (LMS) filtering algorithm run on these signals is demonstrated to be able to reduce the severity of certain types of electrode motion artifacts.

Seamless personal health information system in cloud computing.

Noncontact ECG measurement has gained popularity these days due to its noninvasive and conveniences to be applied on daily life. This approach does not require any direct contact between patient's skin and sensor for physiological signal measurement. The noncontact ECG measurement is integrated with mobile healthcare system for health status monitoring. Mobile phone acts as the personal health information system displaying health status and body mass index (BMI) tracking. Besides that, it plays an important role being the medical guidance providing medical knowledge database including symptom checker and health fitness guidance. At the same time, the system also features some unique medical functions that cater to the living demand of the patients or users, including regular medication reminders, alert alarm, medical guidance, appointment scheduling. Lastly, we demonstrate mobile healthcare system with web application for extended uses, thus health data are clouded into web server system and web database storage. This allows remote health status monitoring easily and so forth it promotes a cost effective personal healthcare system.

アナログ順フィルタとディジタル逆フィルタを用いた相補的な帯域拡張法と非接触心電計測への応用

アナログ順フィルタとディジタル逆フィルタを用いた相補的な帯域拡張法と非接触心電計測への応用

Clinical proof of practicability for an ECG device without any conductive contact

Heart rhythm disturbances are common symptoms of several heart disorders. One of the most effective screening methods is the traditional electrode-based ECG. However, this examination can be both time- and resource-consuming. Capacitive-coupling ECG (cECG) screening--working without any conductive electrical contact with the patient--might help to shorten the time required for diagnosis. In this study, we examine the practicability of employing a non-contact capacitive ECG in a clinical setting. A total of 30 volunteer patients aged over 50 years without pacemakers were included in our trial, after obtaining their written informed consent and their medical history. A cECG as well as a conventional, conductive ECG were recorded simultaneously. In addition to mathematical analysis, ECG data were manually evaluated by two clinicians blinded to the recording method and patient conditions. Data from 30 patients were collected during our study, seven of whom had experienced myocardial infarction. The obtained cECG signals showed a high correlation with the simultaneously recorded Einthoven lead II of the conventional ECG. The values for heart rate, PQ and QT time periods correlated particularly well. Significant differences were observed with regard to QRS duration. Data recorded in the supine position contained less motion artefacts and, in particular, there were fewer breathing artefacts compared to data collected from those in a sitting position. Owing to the easy and quick application of the cECG system, the feedback from the examined patients was consistently positive. In conclusion, recording cECG data in a sitting position provided sufficient quality for screening purposes. Further studies will be needed for the evaluation of cECG appropriateness in diagnosing heart disease.