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Sample records for 12-lead electrocardiogram ecg

  1. The Normal Electrocardiogram: Resting 12-Lead and Electrocardiogram Monitoring in the Hospital.

    PubMed

    Harris, Patricia R E

    2016-09-01

    The electrocardiogram (ECG) is a well-established diagnostic tool extensively used in clinical settings. Knowledge of cardiac rhythm and mastery of cardiac waveform interpretation are fundamental for intensive care nurses. Recognition of the normal findings for the 12-lead ECG and understanding the significance of changes from baseline in continuous cardiac monitoring are essential steps toward ensuring safe patient care. This article highlights historical developments in electrocardiography, describes the normal resting 12-lead ECG, and discusses the need for continuous cardiac monitoring. In addition, future directions for the ECG are explored briefly. PMID:27484657

  2. 12-lead ECG training: the way forward.

    PubMed

    Alinier, Guillaume; Gordon, Ray; Harwood, Colin; Hunt, William B

    2006-01-01

    The teaching of electrocardiography (ECG) monitoring has not changed for decades and still very much relies on access to real patients for practice. However there is nowadays an even greater need for modern training tools in this field as more healthcare professionals than ever before need to be trained on 12-lead ECG monitoring techniques. For example in many parts of the UK ambulance paramedics use features observed from 12-lead ECG monitoring equipment to determine whether or not a patient can receive pre-hospital thrombolytic therapy. Because important decisions are made without the presence of a cardiologist, it is essential that the training is carried out with the most realistic tools, including tools which give realistic feedback of the consequences of incorrect electrode placement. Current mannequins for ECG training are designed with protruding electrodes on the chest, which act as cues for trainees. There is therefore a need for a realistic simulation training tool to teach 12-lead ECG interpretation which includes the ability to give this feedback. We are currently working on the development of such a training tool and it is expected that it will be of great interest to medical, nursing and paramedic schools.

  3. Accurate Interpretation of the 12-Lead ECG Electrode Placement: A Systematic Review

    ERIC Educational Resources Information Center

    Khunti, Kirti

    2014-01-01

    Background: Coronary heart disease (CHD) patients require monitoring through ECGs; the 12-lead electrocardiogram (ECG) is considered to be the non-invasive gold standard. Examples of incorrect treatment because of inaccurate or poor ECG monitoring techniques have been reported in the literature. The findings that only 50% of nurses and less than…

  4. An eight-month evaluation of prehospital 12-lead electrocardiogram monitoring in Baltimore County.

    PubMed

    Brown, J L

    1997-01-01

    The purpose of this evaluation was to determine if a prehospital 12-lead electrocardiogram (ECG) led to a delay in transportation when compared to non-12-lead ECG, and if it led to improved "door to drug" time. A quasi-experimental design was used to compare on-scene times for suspected acute myocardial infarction (AMI) patients; a comparison was made between advanced life support (ALS) units without 12-lead ECG and those who were augmented by equipped EMS district officer units. Our control group had an on-scene time of 22.05 minutes; the mean on-scene time for the experimental group was 21.85 minutes. The results of this study indicated that 12-lead ECG acquisition by district officers did not extend the on-scene time.

  5. 12-lead electrocardiogram features of arrhythmic risk: A focus on early repolarization.

    PubMed

    Rizzo, Caterina; Monitillo, Francesco; Iacoviello, Massimo

    2016-08-26

    The 12-lead electrocardiogram (ECG) is still the most used tool in cardiology clinical practice. Considering its easy accessibility, low cost and the information that it provides, it remains the starting point for diagnosis and prognosis. More specifically, its ability to detect prognostic markers for sudden cardiac death due to arrhythmias by identifying specific patterns that express electrical disturbances of the heart muscle, which may predispose to malignant arrhythmias, is universally recognized. Alterations in the ventricular repolarization process, identifiable on a 12-lead ECG, play a role in the genesis of ventricular arrhythmias in different cardiac diseases. The aim of this paper is to focus the attention on a new marker of arrhythmic risk, the early repolarization pattern in order to highlight the prognostic role of the 12-lead ECG. PMID:27621772

  6. 12-lead electrocardiogram features of arrhythmic risk: A focus on early repolarization

    PubMed Central

    Rizzo, Caterina; Monitillo, Francesco; Iacoviello, Massimo

    2016-01-01

    The 12-lead electrocardiogram (ECG) is still the most used tool in cardiology clinical practice. Considering its easy accessibility, low cost and the information that it provides, it remains the starting point for diagnosis and prognosis. More specifically, its ability to detect prognostic markers for sudden cardiac death due to arrhythmias by identifying specific patterns that express electrical disturbances of the heart muscle, which may predispose to malignant arrhythmias, is universally recognized. Alterations in the ventricular repolarization process, identifiable on a 12-lead ECG, play a role in the genesis of ventricular arrhythmias in different cardiac diseases. The aim of this paper is to focus the attention on a new marker of arrhythmic risk, the early repolarization pattern in order to highlight the prognostic role of the 12-lead ECG. PMID:27621772

  7. 12-lead electrocardiogram features of arrhythmic risk: A focus on early repolarization

    PubMed Central

    Rizzo, Caterina; Monitillo, Francesco; Iacoviello, Massimo

    2016-01-01

    The 12-lead electrocardiogram (ECG) is still the most used tool in cardiology clinical practice. Considering its easy accessibility, low cost and the information that it provides, it remains the starting point for diagnosis and prognosis. More specifically, its ability to detect prognostic markers for sudden cardiac death due to arrhythmias by identifying specific patterns that express electrical disturbances of the heart muscle, which may predispose to malignant arrhythmias, is universally recognized. Alterations in the ventricular repolarization process, identifiable on a 12-lead ECG, play a role in the genesis of ventricular arrhythmias in different cardiac diseases. The aim of this paper is to focus the attention on a new marker of arrhythmic risk, the early repolarization pattern in order to highlight the prognostic role of the 12-lead ECG.

  8. A cloud computing based 12-lead ECG telemedicine service

    PubMed Central

    2012-01-01

    Background Due to the great variability of 12-lead ECG instruments and medical specialists’ interpretation skills, it remains a challenge to deliver rapid and accurate 12-lead ECG reports with senior cardiologists’ decision making support in emergency telecardiology. Methods We create a new cloud and pervasive computing based 12-lead Electrocardiography (ECG) service to realize ubiquitous 12-lead ECG tele-diagnosis. Results This developed service enables ECG to be transmitted and interpreted via mobile phones. That is, tele-consultation can take place while the patient is on the ambulance, between the onsite clinicians and the off-site senior cardiologists, or among hospitals. Most importantly, this developed service is convenient, efficient, and inexpensive. Conclusions This cloud computing based ECG tele-consultation service expands the traditional 12-lead ECG applications onto the collaboration of clinicians at different locations or among hospitals. In short, this service can greatly improve medical service quality and efficiency, especially for patients in rural areas. This service has been evaluated and proved to be useful by cardiologists in Taiwan. PMID:22838382

  9. Self-organized neural network for the quality control of 12-lead ECG signals.

    PubMed

    Chen, Yun; Yang, Hui

    2012-09-01

    Telemedicine is very important for the timely delivery of health care to cardiovascular patients, especially those who live in the rural areas of developing countries. However, there are a number of uncertainty factors inherent to the mobile-phone-based recording of electrocardiogram (ECG) signals such as personnel with minimal training and other extraneous noises. PhysioNet organized a challenge in 2011 to develop efficient algorithms that can assess the ECG signal quality in telemedicine settings. This paper presents our efforts in this challenge to integrate multiscale recurrence analysis with a self-organizing map for controlling the ECG signal quality. As opposed to directly evaluating the 12-lead ECG, we utilize an information-preserving transform, i.e. Dower transform, to derive the 3-lead vectorcardiogram (VCG) from the 12-lead ECG in the first place. Secondly, we delineate the nonlinear and nonstationary characteristics underlying the 3-lead VCG signals into multiple time-frequency scales. Furthermore, a self-organizing map is trained, in both supervised and unsupervised ways, to identify the correlations between signal quality and multiscale recurrence features. The efficacy and robustness of this approach are validated using real-world ECG recordings available from PhysioNet. The average performance was demonstrated to be 95.25% for the training dataset and 90.0% for the independent test dataset with unknown labels.

  10. The 24-lead ECG display for enhanced recognition of STEMI-equivalent patterns in the 12-lead ECG.

    PubMed

    Pahlm, Ulrika; Pahlm, Olle; Wagner, Galen S

    2014-01-01

    In a patient with chest pain and suspected acute coronary syndrome, the electrocardiogram (ECG) is the only readily available diagnostic tool. It is important to maximize its usefulness to detect acute myocardial ischemia that may evolve to myocardial infarction unless the patient is treated expediently with reperfusion therapy. Since diagnostic guidelines have usually included only ST-elevation myocardial infarction (STEMI) as the entity that should be diagnosed and treated urgently, a patient with coronary occlusion represented on ECG as ST depression is likely not to be considered a candidate for receiving immediate coronary angiography and coronary intervention. ECG criteria for STEMI detection require that ST elevation meet predetermined millivolt thresholds and appear in at least two spatially contiguous ECG leads. The typical ECG reader recognizes only three contiguous pairs: aVL and I; II and aVF; aVF and III. However, viewing the "orderly sequenced" 12-lead ECG display, two more contiguous pairs become obvious in the frontal plane: +I and -aVR; -aVR and +II. The 24-lead ECG is a display of the standard 12-lead ECG as both the classical positive leads and their negative (inverted) counterparts. Leads +V1, +V2, +V3, +V4, +V5, and +V6 and their inverted counterparts are used to generate a "clock-face display" for the transverse plane. Similarly, +aVL, +I, -aVR, +II, +aVF, +III in the frontal plane and their inverted counterparts are used to generate a clock-face display for the frontal plane. Optimum results, 78% sensitivity and 93% specificity, were obtained using the following 19 ECG leads: frontal plane: +aVR, -III, +aVL, +I, -aVR, +II, +aVF, +III, -aVL; transverse plane: +V1, +V2, +V3, +V4, +V5, +V6, -V1, -V2, -V3.

  11. The 24-lead ECG display for enhanced recognition of STEMI-equivalent patterns in the 12-lead ECG.

    PubMed

    Pahlm, Ulrika; Pahlm, Olle; Wagner, Galen S

    2014-01-01

    In a patient with chest pain and suspected acute coronary syndrome, the electrocardiogram (ECG) is the only readily available diagnostic tool. It is important to maximize its usefulness to detect acute myocardial ischemia that may evolve to myocardial infarction unless the patient is treated expediently with reperfusion therapy. Since diagnostic guidelines have usually included only ST-elevation myocardial infarction (STEMI) as the entity that should be diagnosed and treated urgently, a patient with coronary occlusion represented on ECG as ST depression is likely not to be considered a candidate for receiving immediate coronary angiography and coronary intervention. ECG criteria for STEMI detection require that ST elevation meet predetermined millivolt thresholds and appear in at least two spatially contiguous ECG leads. The typical ECG reader recognizes only three contiguous pairs: aVL and I; II and aVF; aVF and III. However, viewing the "orderly sequenced" 12-lead ECG display, two more contiguous pairs become obvious in the frontal plane: +I and -aVR; -aVR and +II. The 24-lead ECG is a display of the standard 12-lead ECG as both the classical positive leads and their negative (inverted) counterparts. Leads +V1, +V2, +V3, +V4, +V5, and +V6 and their inverted counterparts are used to generate a "clock-face display" for the transverse plane. Similarly, +aVL, +I, -aVR, +II, +aVF, +III in the frontal plane and their inverted counterparts are used to generate a clock-face display for the frontal plane. Optimum results, 78% sensitivity and 93% specificity, were obtained using the following 19 ECG leads: frontal plane: +aVR, -III, +aVL, +I, -aVR, +II, +aVF, +III, -aVL; transverse plane: +V1, +V2, +V3, +V4, +V5, +V6, -V1, -V2, -V3. PMID:24880763

  12. Automated J wave detection from digital 12-lead electrocardiogram.

    PubMed

    Wang, Yi Grace; Wu, Hau-Tieng; Daubechies, Ingrid; Li, Yabing; Estes, E Harvey; Soliman, Elsayed Z

    2015-01-01

    In this report we provide a method for automated detection of J wave, defined as a notch or slur in the descending slope of the terminal positive wave of the QRS complex, using signal processing and functional data analysis techniques. Two different sets of ECG tracings were selected from the EPICARE ECG core laboratory, Wake Forest School of Medicine, Winston Salem, NC. The first set was a training set comprised of 100 ECGs of which 50 ECGs had J-wave and the other 50 did not. The second set was a test set (n=116 ECGs) in which the J-wave status (present/absent) was only known by the ECG Center staff. All ECGs were recorded using GE MAC 1200 (GE Marquette, Milwaukee, Wisconsin) at 10mm/mV calibration, speed of 25mm/s and 500HZ sampling rate. All ECGs were initially inspected visually for technical errors and inadequate quality, and then automatically processed with the GE Marquette 12-SL program 2001 version (GE Marquette, Milwaukee, WI). We excluded ECG tracings with major abnormalities or rhythm disorder. Confirmation of the presence or absence of a J wave was done visually by the ECG Center staff and verified once again by three of the coauthors. There was no disagreement in the identification of the J wave state. The signal processing and functional data analysis techniques applied to the ECGs were conducted at Duke University and the University of Toronto. In the training set, the automated detection had sensitivity of 100% and specificity of 94%. For the test set, sensitivity was 89% and specificity was 86%. In conclusion, test results of the automated method we developed show a good J wave detection accuracy, suggesting possible utility of this approach for defining and detection of other complex ECG waveforms.

  13. 1.5 Tesla MRI-Conditional 12-lead ECG for MR Imaging and Intra-MR Intervention

    PubMed Central

    Tse, Zion Tsz Ho; Dumoulin, Charles L.; Clifford, Gari D.; Schweitzer, Jeff; Qin, Lei; Oster, Julien; Jerosch-Herold, Michael; Kwong, Raymond Y.; Michaud, Gregory; Stevenson, William G.; Schmidt, Ehud J.

    2013-01-01

    Propose High-fidelity 12-lead Electrocardiogram (ECG) is important for physiological monitoring of patients during MR-guided intervention and cardiac MR imaging. Issues in obtaining non-corrupted ECGs inside MRI include a superimposed Magneto-Hydro-Dynamic (MHD) voltage, gradient-switching induced-voltages, and radiofrequency (RF) heating. These problems increase with magnetic field. We intended to develop and clinically validate a 1.5T MRI-conditional 12-lead ECG system. Methods The system was constructed, including transmission-lines to reduce radio-frequency induction, and switching-circuits to remove induced voltages. Adaptive filters, trained by 12-lead measurements outside MRI and in two orientations inside MRI, were used to remove MHD. The system was tested on ten (one exercising) volunteers and four arrhythmia patients. Results Switching circuits removed most imaging-induced voltages (residual noise <3% of the R-wave). MHD removal provided intra-MRI ECGs that varied by <3.8% from those outside the MRI, preserving the true ST segment. In premature-ventricular-contraction (PVC) patients, clean ECGs separated PVC and sinus-rhythm beats. Measured heating was <1.5 C0. The system reliably acquired multiphase (SSFP) wall-motion-cine and phase-contrast-cine scans, including in subjects where 4-lead gating failed. The system required a minimum TR of 4ms to allow robust ECG processing. Conclusion High-fidelity intra-MRI 12-lead ECG is possible. PMID:23580148

  14. A simplified 3D model of whole heart electrical activity and 12-lead ECG generation.

    PubMed

    Sovilj, Siniša; Magjarević, Ratko; Lovell, Nigel H; Dokos, Socrates

    2013-01-01

    We present a computationally efficient three-dimensional bidomain model of torso-embedded whole heart electrical activity, with spontaneous initiation of activation in the sinoatrial node, incorporating a specialized conduction system with heterogeneous action potential morphologies throughout the heart. The simplified geometry incorporates the whole heart as a volume source, with heart cavities, lungs, and torso as passive volume conductors. We placed four surface electrodes at the limbs of the torso: V R , V L , V F and V GND and six electrodes on the chest to simulate the Einthoven, Goldberger-augmented and precordial leads of a standard 12-lead system. By placing additional seven electrodes at the appropriate torso positions, we were also able to calculate the vectorcardiogram of the Frank lead system. Themodel was able to simulate realistic electrocardiogram (ECG) morphologies for the 12 standard leads, orthogonal X, Y, and Z leads, as well as the vectorcardiogram under normal and pathological heart states. Thus, simplified and easy replicable 3D cardiac bidomain model offers a compromise between computational load and model complexity and can be used as an investigative tool to adjust cell, tissue, and whole heart properties, such as setting ischemic lesions or regions of myocardial infarction, to readily investigate their effects on whole ECG morphology.

  15. Data-driven estimation of cardiac electrical diffusivity from 12-lead ECG signals.

    PubMed

    Zettinig, Oliver; Mansi, Tommaso; Neumann, Dominik; Georgescu, Bogdan; Rapaka, Saikiran; Seegerer, Philipp; Kayvanpour, Elham; Sedaghat-Hamedani, Farbod; Amr, Ali; Haas, Jan; Steen, Henning; Katus, Hugo; Meder, Benjamin; Navab, Nassir; Kamen, Ali; Comaniciu, Dorin

    2014-12-01

    Diagnosis and treatment of dilated cardiomyopathy (DCM) is challenging due to a large variety of causes and disease stages. Computational models of cardiac electrophysiology (EP) can be used to improve the assessment and prognosis of DCM, plan therapies and predict their outcome, but require personalization. In this work, we present a data-driven approach to estimate the electrical diffusivity parameter of an EP model from standard 12-lead electrocardiograms (ECG). An efficient forward model based on a mono-domain, phenomenological Lattice-Boltzmann model of cardiac EP, and a boundary element-based mapping of potentials to the body surface is employed. The electrical diffusivity of myocardium, left ventricle and right ventricle endocardium is then estimated using polynomial regression which takes as input the QRS duration and electrical axis. After validating the forward model, we computed 9500 EP simulations on 19 different DCM patients in just under three seconds each to learn the regression model. Using this database, we quantify the intrinsic uncertainty of electrical diffusion for given ECG features and show in a leave-one-patient-out cross-validation that the regression method is able to predict myocardium diffusion within the uncertainty range. Finally, our approach is tested on the 19 cases using their clinical ECG. 84% of them could be personalized using our method, yielding mean prediction errors of 18.7ms for the QRS duration and 6.5° for the electrical axis, both values being within clinical acceptability. By providing an estimate of diffusion parameters from readily available clinical data, our data-driven approach could therefore constitute a first calibration step toward a more complete personalization of cardiac EP. PMID:24857832

  16. Improved recording of atrial activity by modified bipolar leads derived from the 12-lead electrocardiogram.

    PubMed

    Kennedy, Alan; Finlay, Dewar D; Guldenring, Daniel; Bond, Raymond R; McEneaney, David J; Peace, Aaron; McLaughlin, James

    2015-01-01

    This study investigates the use of multivariate linear regression to estimate three bipolar ECG leads from the 12-lead ECG in order to improve P-wave signal strength. The study population consisted of body surface potential maps recorded from 229 healthy subjects. P-waves were then isolated and population based transformation weights developed. A derived P-lead (measured between the right sternoclavicular joint and midway along the costal margin in line with the seventh intercostal space) demonstrated significant improvement in median P-wave root mean square (RMS) signal strength when compared to lead II (94μV vs. 76μV, p<0.001). A derived ES lead (from the EASI lead system) also showed small but significant improvement in median P-wave RMS (79μV vs. 76μV, p=0.0054). Finally, a derived modified Lewis lead did not improve median P-wave RMS when compared to lead II. However, this derived lead improved atrioventricular RMS ratio. P-wave leads derived from the 12-lead ECG can improve signal-to-noise ratio of the P-wave; this may improve the performance of detection algorithms that rely on P-wave analysis.

  17. Value of posterior and right ventricular leads in comparison to the standard 12-lead electrocardiogram in evaluation of ST-segment elevation in suspected acute myocardial infarction.

    PubMed

    Zalenski, R J; Rydman, R J; Sloan, E P; Hahn, K H; Cooke, D; Fagan, J; Fligner, D J; Hessions, W; Justis, D; Kampe, L M; Shah, S; Tucker, J; Zwicke, D

    1997-06-15

    In this multicenter prospective trial, we studied posterior (V7 to V9) and right ventricular (V4R to V6R) leads to assess their accuracy compared with standard 12-lead electrocardiograms (ECGs) for the diagnosis of acute myocardial infarction (AMI). Patients aged >34 years with suspected AMI received posterior and right ventricular leads immediately after the initial 12-lead ECG. ST elevation of 0.1 mV in 2 leads was blindly determined and inter-rater reliability estimated. AMI was diagnosed by World Health Organization criteria. The diagnostic value of nonstandard leads was determined when 12-lead ST elevation was absent and present and multivariate stepwise regression analysis was also performed. Of 533 study patients, 64.7% (345 of 533) had AMI and 24.8% received thrombolytic therapy. Posterior and right ventricular leads increased sensitivity for AMI by 8.4% (p = 0.03) but decreased specificity by 7.0% (p = 0.06). The likelihood ratios of a positive test for 12, 12 + posterior, and 12 + right ventricular ECGs were 6.4, 5.6, and 4.5, respectively. Increased AMI rates (positive predictive values) were found when ST elevation was present on 6 nonstandard leads (69.1%), on 12 leads only (88.4%), and on both 6 and 12 leads (96.8%; p <0.001). Treatment rates with thrombolytic therapy increased in parallel with this electrocardiographic gradient. Logistic regression analysis showed that 4 leads were independently predictive of AMI (p <0.001): leads I, II, V3, V5R; V9 approached statistical significance (p = 0.055). The standard ECG is not optimal for detecting ST-segment elevation in AMI, but its accuracy is only modestly improved by the addition of posterior and right ventricular leads. PMID:9202344

  18. Risk stratifying asymptomatic aortic stenosis: role of the resting 12-lead ECG.

    PubMed

    Greve, Anders M

    2014-02-01

    Despite being routinely performed in the clinical follow-up of asymptomatic AS patients, little or no evidence describes the prognostic value of ECG findings in asymptomatic AS populations. This PhD thesis examined the correlates of resting 12-lead ECG variables with echocardiographic measures of AS severity and cardiovascular outcomes in the till date largest cohort (n=1,563) of asymptomatic patients with mild-to-moderate AS. Most importantly, this PhD thesis demonstrated that QRS-duration adds independent predictive value of sudden cardiac death and that the additional presence of ECG LVH/strain for fixed AS severity represents a lethal risk attribute. Finally, ECG abnormalities displayed low/moderate concordance with echocardiographic parameters. This argues that the ECG should be regarded as a separate tool for obtaining prognostically important information. Treatment was not randomized by ECG findings, future studies should therefore examine if and which ECG variables should elicit closer follow-up and/or earlier intervention to improve prognosis in asymptomatic AS populations. PMID:24495893

  19. Wireless Self-Acquistion of 12-Lead ECG via Android Smart Phone

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.

    2012-01-01

    Researchers at NASA s Johnson Space Center and at Orbital Research, Inc. (a NASA SBIR grant recipient) have recently developed a dry-electrode harness that allows for self-acquisition of resting 12-lead ECGs by minimally trained laypersons. When used in conjunction with commercial wireless (e.g., Bluetooth(TM) or 802.11-enabled) 12-lead ECG devices and custom smart phone-based software, the collected 12-lead ECG data can also immediately be forwarded from any geographic location within cellular range to the user s physician(s) of choice. The system can also be used to immediately forward to central receiving stations 12-lead ECG data collected during space flight or during activities in any remote terrestrial location supported by an internet or cellular phone infrastructure. The main novel aspects of the system are first, the dry-electrode 12-lead ECG harness itself, and second, an accompanying Android(TM) smart phone-based wireless 12-lead ECG capability. The ECG harness nominally employs dry electrodes manufactured by Orbital Research, Inc, recently cleared through the Food and Drug Administration (FDA). However, other dry electrodes that are not yet FDA cleared, for example those recently developed by Nanosonic, Inc as part of another NASA SBIR grant, can also be used. The various advantageous features of the harness include: 1) laypersons can be quickly instructed on its correct use, remotely if necessary; 2) all tangled "leadwire spaghetti" is eliminated, as is the common clinical problem of "leadwire reversal"; 3) all adhesives and disposables are also eliminated, the harness being fully reusable; if multiple individuals intend to use use the same harness, then standard antimicrobial wipes can be employed to sterilize the dry electrodes (and harness surface if needed) between users; 5) padded cushions at the lateral sides of the torso function to press the left arm (LA) and right arm (RA) dry electrodes mounted on the cushions against sideward or downward

  20. Noninvasive Diagnosis of Coronary Artery Disease Using 12-Lead High-Frequency Electrocardiograms

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian

    2006-01-01

    method is the presence versus the absence of reduced-amplitude zones (RAZs). In terms that must be simplified for the sake of brevity, an RAZ comprises several cycles of a high-frequency QRS signal during which the amplitude of the high-frequency oscillation in a portion of the signal is abnormally low (see figure). A given signal sample exhibiting an interval of reduced amplitude may or may not be classified as an RAZ, depending on quantitative criteria regarding peaks and troughs within the reduced-amplitude portion of the high-frequency QRS signal. This analysis is performed in all 12 leads in real time.

  1. New Padded Harness for Self-Acquisition of Resting 12-Lead ECGs

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Rood, A. T.

    2011-01-01

    We have developed a dry-electrode harness that permits easy, rapid, and unsupervised self-acquisition of resting 12-lead ECGs without the use of any disposables. Various other advantageous features of the harness include: 1) padded or inflatable cushions at the lateral sides of the torso that function to press the left arm (LA) and right arm (RA) dry electrodes mounted on cushions against sideward (as shown in the Figure below) or downward-rested arms of the subject; 2) sufficient distal placement of the arm electrodes with good abutment and without the need for adhesives, straps, bands, bracelets, or gloves on the arms; 3) padding over the sternum to avoid "tenting" in the V1 through V3 (and V3R, when present) electrode positions; 4) easy-to-don, one-piece design with an adjustable single point of connection and an adjustable shoulder strap; and 5) Lund or "modified Lund" placement of the dry electrodes, the results of which more effectively reproduce results from "standard" 12-lead ECG placements than do results from Mason-Likar lead placements.

  2. Construction and Use of Resting 12-Lead High Fidelity ECG "SuperScores" in Screening for Heart Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Arenare, B.; Greco, E. C.; DePalma, J. L.; Starc, V.; Nunez, T.; Medina, R.; Jugo, D.; Rahman, M.A.; Delgado, R.

    2007-01-01

    We investigated the accuracy of several conventional and advanced resting ECG parameters for identifying obstructive coronary artery disease (CAD) and cardiomyopathy (CM). Advanced high-fidelity 12-lead ECG tests (approx. 5-min supine) were first performed on a "training set" of 99 individuals: 33 with ischemic or dilated CM and low ejection fraction (EF less than 40%); 33 with catheterization-proven obstructive CAD but normal EF; and 33 age-/gender-matched healthy controls. Multiple conventional and advanced ECG parameters were studied for their individual and combined retrospective accuracies in detecting underlying disease, the advanced parameters falling within the following categories: 1) Signal averaged ECG, including 12-lead high frequency QRS (150-250 Hz) plus multiple filtered and unfiltered parameters from the derived Frank leads; 2) 12-lead P, QRS and T-wave morphology via singular value decomposition (SVD) plus signal averaging; 3) Multichannel (12-lead, derived Frank lead, SVD lead) beat-to-beat QT interval variability; 4) Spatial ventricular gradient (and gradient component) variability; and 5) Heart rate variability. Several multiparameter ECG SuperScores were derivable, using stepwise and then generalized additive logistic modeling, that each had 100% retrospective accuracy in detecting underlying CM or CAD. The performance of these same SuperScores was then prospectively evaluated using a test set of another 120 individuals (40 new individuals in each of the CM, CAD and control groups, respectively). All 12-lead ECG SuperScores retrospectively generated for CM continued to perform well in prospectively identifying CM (i.e., areas under the ROC curve greater than 0.95), with one such score (containing just 4 components) maintaining 100% prospective accuracy. SuperScores retrospectively generated for CAD performed somewhat less accurately, with prospective areas under the ROC curve typically in the 0.90-0.95 range. We conclude that resting 12-lead

  3. Accuracy of advanced versus strictly conventional 12-lead ECG for detection and screening of coronary artery disease, left ventricular hypertrophy and left ventricular systolic dysfunction

    PubMed Central

    2010-01-01

    Background Resting conventional 12-lead ECG has low sensitivity for detection of coronary artery disease (CAD) and left ventricular hypertrophy (LVH) and low positive predictive value (PPV) for prediction of left ventricular systolic dysfunction (LVSD). We hypothesized that a ~5-min resting 12-lead advanced ECG test ("A-ECG") that combined results from both the advanced and conventional ECG could more accurately screen for these conditions than strictly conventional ECG. Methods Results from nearly every conventional and advanced resting ECG parameter known from the literature to have diagnostic or predictive value were first retrospectively evaluated in 418 healthy controls and 290 patients with imaging-proven CAD, LVH and/or LVSD. Each ECG parameter was examined for potential inclusion within multi-parameter A-ECG scores derived from multivariate regression models that were designed to optimally screen for disease in general or LVSD in particular. The performance of the best retrospectively-validated A-ECG scores was then compared against that of optimized pooled criteria from the strictly conventional ECG in a test set of 315 additional individuals. Results Compared to optimized pooled criteria from the strictly conventional ECG, a 7-parameter A-ECG score validated in the training set increased the sensitivity of resting ECG for identifying disease in the test set from 78% (72-84%) to 92% (88-96%) (P < 0.0001) while also increasing specificity from 85% (77-91%) to 94% (88-98%) (P < 0.05). In diseased patients, another 5-parameter A-ECG score increased the PPV of ECG for LVSD from 53% (41-65%) to 92% (78-98%) (P < 0.0001) without compromising related negative predictive value. Conclusion Resting 12-lead A-ECG scoring is more accurate than strictly conventional ECG in screening for CAD, LVH and LVSD. PMID:20565702

  4. Real-Time Online Monitoring of Electrocardiogram (ECG) using Very Low Cost for Developing Countries

    NASA Astrophysics Data System (ADS)

    Singh, Gavendra; Gupta, Varun; Sekharmantri, Anil Kumar; Gupta, Akash; Kumar, Pankaj

    2010-11-01

    An electrocardiogram or ECG (also known as EKG—abbreviated from the German word Elektro-Kardiographie), is an electrical recording of the heart and is used in the investigation of heart disease. `An electrocardiogram (ECG) is a graphic tracing of the electric current generated by the heart muscle during a heartbeat'. The electrocardiogram (ECG)/(EKG) is a surface measurement of the electrical potential generated by electrical activity in cardiac tissue. It has been used extensively in medicine sine its inventions in the early 1900' sand has been proven to be invaluable in various diagnostics applications such as the detection of irregular heartbeat patterns (i.e. fibrillation & arrhythmia), hearts murmurs (other abnormal sounds), tissue/structural damage (such as valve malfunction) and coronary artery blockage. In this paper we made a circuit network by using this circuit we can acquire an ECG signal of the heart electrical activity. This is one of the cheapest circuit to acquire ECG signal. It's whole cost around Rs.250/- only. Instrumentation amplifier AD620AN, notch filter, various resistances, capacitors, wires etc. are used to made this circuit.

  5. Use of electrocardiogram (ECG) electrodes for Bioelectrical Impedance Analysis (BIA)

    NASA Astrophysics Data System (ADS)

    Caicedo-Eraso, J. C.; González-Correa, C. H.; González-Correa, C. A.

    2012-12-01

    BIA is a safe, noninvasive, portable and relatively inexpensive method of estimating body composition that is practical and suitable for individual use and large-scale studies. However, the cost of the electrodes recommended by some BIA manufacturers is too high for developing countries; where very often the long and complicated process of importation reduces the time they can be used. The purpose of this study was to evaluate the use of two types of ECG electrodes (2290 and 2228 by 3M®) in BIA measurements to decrease the costs of the test. The results showed that the 2228 ECG electrodes can be used in BIA measurements for adult's body composition assessment. These electrodes are available in the domestic market and their costs are 92% lower than the electrodes recommended by manufacturer. The results show a new cost-benefit relation for BIA method and make this a more accessible tool for individual tests, large-scale researches and studies in the community.

  6. Simple electrocardiogram (ECG) signal analyzer for homecare system among the elderly.

    PubMed

    Lin, Liuh-Chii; Yeh, Yun-Chi; Ho, Kuei-Jung

    2015-01-01

    This study presents a simple electrocardiogram (ECG) signal analyzer for homecare system among the elderly. It can transmit ECG signals of patient around his/her house through Bluetooth to computers in house. ECG signals are analyzed by the computer. If abnormal case of heartbeat is found, the emergency call is automatically dialed. Meanwhile, the determined heartbeat case of ECG signals will be forwarded to patient's MD through internet. Therefore, the patient can do whatever he/she wants around his/her house with our proposed simple cardiac arrhythmias signal analyzer. The proposed consists of five major processing stages: (i) preprocessing stage for enlarging ECG signals' amplitude and eliminating noises; (ii) ECG signal transmitter/receiver stage, ECG signals are transmitted through Bluetooth to the signal receiver in patient's house; (iii) QRS extraction stage for detecting QRS waveform using the Difference Operation Method (DOM) method; (iv) qualitative features stage for qualitative feature selection on ECG signals; and (v) classification stage for determining patient's heartbeat cases using the Principal Component Analysis (PCA) method. In the experiment, the total classification accuracy (TCA) was approximately 93.19% in average.

  7. Simple electrocardiogram (ECG) signal analyzer for homecare system among the elderly.

    PubMed

    Lin, Liuh-Chii; Yeh, Yun-Chi; Ho, Kuei-Jung

    2015-01-01

    This study presents a simple electrocardiogram (ECG) signal analyzer for homecare system among the elderly. It can transmit ECG signals of patient around his/her house through Bluetooth to computers in house. ECG signals are analyzed by the computer. If abnormal case of heartbeat is found, the emergency call is automatically dialed. Meanwhile, the determined heartbeat case of ECG signals will be forwarded to patient's MD through internet. Therefore, the patient can do whatever he/she wants around his/her house with our proposed simple cardiac arrhythmias signal analyzer. The proposed consists of five major processing stages: (i) preprocessing stage for enlarging ECG signals' amplitude and eliminating noises; (ii) ECG signal transmitter/receiver stage, ECG signals are transmitted through Bluetooth to the signal receiver in patient's house; (iii) QRS extraction stage for detecting QRS waveform using the Difference Operation Method (DOM) method; (iv) qualitative features stage for qualitative feature selection on ECG signals; and (v) classification stage for determining patient's heartbeat cases using the Principal Component Analysis (PCA) method. In the experiment, the total classification accuracy (TCA) was approximately 93.19% in average. PMID:26684565

  8. Effect of a real-time tele-transmission system of 12-lead electrocardiogram on the first-aid for athletes with ST-elevation myocardial infarction.

    PubMed

    Zhang, Huan; Song, Donghan; An, Lina

    2016-05-01

    To study the effect of a real-time tele-transmission system of 12-lead electrocardiogram on door-to-balloon time in athletes with ST-elevation myocardial infarction. A total of 60 athletes with chest pain diagnosed as ST-elevation myocardial infarction (STEMI) from our hospital were randomly divided into group A (n=35) and group B (n=25), the patients in group A transmitted the real-time tele-transmission system of 12-lead electrocardiogram to the chest pain center before arriving in hospital, however, the patients in group B not. The median door-to-balloon time was significant shorter in-group A than group B (38min vs 94 min, p<0.01) and the ratio of door-to-balloon time below 90 min was remarkable higher in-group A (94.2% vs 60%, p<0.01). The rate of catheter laboratory occupied was 5.7% in-group A and 40% in group B respectively (p=0.001). There was no statistically difference in mortality between the two groups (5.7% vs 4%, p>0.05). The median length of stay was significant reduced in-group A (5 days vs 7 days, p<0.01). Real-time tele-transmission system of 12 lead electrocardiogram is beneficial to the pre-hospital diagnosis of STEMI. PMID:27383498

  9. Electrocardiogram

    MedlinePlus

    ECG; EKG ... important to be relaxed and warm during an ECG recording because any movement, including shivering, can alter ... for changes in the heart. This type of ECG is often called a stress test.

  10. Compression of the electrocardiogram (ECG) using an adaptive orthonomal wavelet basis architecture

    NASA Astrophysics Data System (ADS)

    Anandkumar, Janavikulam; Szu, Harold H.

    1995-04-01

    This paper deals with the compression of electrocardiogram (ECG) signals using a large library of orthonormal bases functions that are translated and dilated versions of Daubechies wavelets. The wavelet transform has been implemented using quadrature mirror filters (QMF) employed in a sub-band coding scheme. Interesting transients and notable frequencies of the ECG are captured by appropriately scaled waveforms chosen in a parallel fashion from this collection of wavelets. Since there is a choice of orthonormal bases functions for the efficient transcription of the ECG, it is then possible to choose the best one by various criterion. We have imposed very stringent threshold conditions on the wavelet expansion coefficients, such as in maintaining a very large percentage of the energy of the current signal segment, and this has resulted in reconstructed waveforms with negligible distortion relative to the source signal. Even without the use of any specialized quantizers and encoders, the compression ratio numbers look encouraging, with preliminary results indicating compression ratios ranging from 40:1 to 15:1 at percentage rms distortions ranging from about 22% to 2.3%, respectively. Irrespective of the ECG lead chosen, or the signal deviations that may occur due to either noise or arrhythmias, only one wavelet family that correlates best with that particular portion of the signal, is chosen. The main reason for the compression is because the chosen mother wavelet and its variations match the shape of the ECG and are able to efficiently transcribe the source with few wavelet coefficients. The adaptive template matching architecture that carries out a parallel search of the transform domain is described, and preliminary simulation results are discussed. The adaptivity of the architecture comes from the fine tuning of the wavelet selection process that is based on localized constraints, such as shape of the signal and its energy.

  11. Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

    PubMed

    van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

    2015-01-01

    medical image data (pixel size <1.5mm). For the lungs and torso the number of triangles in the mesh was reduced, thus decreasing the accuracy of the reconstructed mesh. A novel software tool has been introduced, which is able to reconstruct accurate cardiac anatomical models from MRI or CT within only a few hours. This new anatomical reconstruction tool might reduce the modeling errors within the cardiac isochrone positioning system and thus enable the clinical application of CIPS to localize the PVC/VT focus to the ventricular myocardium from only the standard 12 lead ECG.

  12. Tissue Doppler Imaging Combined with Advanced 12-Lead ECG Analysis Might Improve Early Diagnosis of Hypertrophic Cardiomyopathy in Childhood

    NASA Technical Reports Server (NTRS)

    Femlund, E.; Schlegel, T.; Liuba, P.

    2011-01-01

    Optimization of early diagnosis of childhood hypertrophic cardiomyopathy (HCM) is essential in lowering the risk of HCM complications. Standard echocardiography (ECHO) has shown to be less sensitive in this regard. In this study, we sought to assess whether spatial QRS-T angle deviation, which has shown to predict HCM in adults with high sensitivity, and myocardial Tissue Doppler Imaging (TDI) could be additional tools in early diagnosis of HCM in childhood. Methods: Children and adolescents with familial HCM (n=10, median age 16, range 5-27 years), and without obvious hypertrophy but with heredity for HCM (n=12, median age 16, range 4-25 years, HCM or sudden death with autopsy-verified HCM in greater than or equal to 1 first-degree relative, HCM-risk) were additionally investigated with TDI and advanced 12-lead ECG analysis using Cardiax(Registered trademark) (IMED Co Ltd, Budapest, Hungary and Houston). Spatial QRS-T angle (SA) was derived from Kors regression-related transformation. Healthy age-matched controls (n=21) were also studied. All participants underwent thorough clinical examination. Results: Spatial QRS-T angle (Figure/ Panel A) and septal E/Ea ratio (Figure/Panel B) were most increased in HCM group as compared to the HCM-risk and control groups (p less than 0.05). Of note, these 2 variables showed a trend toward higher levels in HCM-risk group than in control group (p=0.05 for E/Ea and 0.06 for QRS/T by ANOVA). In a logistic regression model, increased SA and septal E/Ea ratio appeared to significantly predict both the disease (Chi-square in HCM group: 9 and 5, respectively, p less than 0.05 for both) and the risk for HCM (Chi-square in HCM-risk group: 5 and 4 respectively, p less than 0.05 for both), with further increased predictability level when these 2 variables were combined (Chi-square 10 in HCM group, and 7 in HCM-risk group, p less than 0.01 for both). Conclusions: In this small material, Tissue Doppler Imaging and spatial mean QRS-T angle

  13. Localization of precise origin of idiopathic ventricular tachycardia from the right ventricular outflow tract by a 12-lead ECG: a study of pace mapping using a multielectrode "basket" catheter.

    PubMed

    Yoshida, Y; Hirai, M; Murakami, Y; Kondo, T; Inden, Y; Akahoshi, M; Tsuda, M; Okamoto, M; Yamada, T; Tsuboi, N; Hirayama, H; Ito, T; Toyama, J; Saito, H

    1999-12-01

    Radiofrequency catheter ablation guided by pace-mapping techniques has proven effective in eliminating idiopathic ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT). A method for rapidly identifying the origin of VT from 12-lead electrocardiogram (ECG) findings would be helpful for the catheter ablation procedure. The purpose of this study is to precisely localize the origin of idiopathic VT from the RVOT by a 12-lead ECG from a study of multipoint pace mapping. In one patient with premature ventricular complex (PVC) and 3 with VT, a "basket" catheter was deployed in the RVOT for bipolar pacing from 56 sites in the endocardium of RVOT. Under fluoroscopy the pacing sites were classified into the septum and free wall. We investigated the QRS morphology in leads, I, II, and III; the depth of the QS wave in leads aVR and aVL; and the height of the initial r wave in leads V1 and V2. Pacing was captured in 30-47 of 56 sites (54%-84%). As the pacing sites changed from the anterior to posterior of the septum, the QS notch (-) type in lead I shifted through rs to R, while a shift from R type to rR' or Rr' was noted in leads II and III. As the pacing sites changed from the anterior to posterior of the free wall, lead I showed a shift from the QS notch (+) type to R, while a shift from rR' to Rr' (or rR' unchanged) was found in leads II and III. The depth of the QS wave in leads aVR and aVL showed a tendency for aVR to be deeper than aVL toward the posterolateral attachment of both the septum and free wall, whereas aVL tended to be deeper than aVR toward the anterior attachment. The initial r waves in V1 and V2 became greater as the pacing site was positioned at a higher or more posterior location. These findings may provide more precise and clinically useful diagnostic information on the site of the origin of idiopathic VT originating from the RVOT by a 12-lead ECG.

  14. 12-lead Holter electrocardiography. Review of the literature and clinical application update.

    PubMed

    Su, Li; Borov, Stefan; Zrenner, Bernhard

    2013-06-01

    This brief review is focused on 12-lead Holter electrocardiogram (ECG) recording including a review of the literature and the description of the advantages of its application. The standard 12-lead ECG provides a bedside snapshot of the electrical activity of the heart including vector information, but a snapshot of a few beats for some seconds might miss the whole story. Traditional Holter ECG displaying two or three leads may record all heart beats during a prolonged period, but the limited vector information might be a cause of shortcomings in the ECG diagnosis. The 12-lead Holter ECG overcomes these disadvantages and should be preferred for detecting episodes of arrhythmias, localize their origin or the localization of myocardial ischemia. The 12-lead Holter ECG monitoring is efficient in the evaluation of the effect of drugs or interventional therapeutic procedures, i.e., efficiency of biventricular pacing in patients with heart failure and permanent atrial fibrillation (AF). The automatic analysis of parameters in 12-lead Holter ECG is also providing information for risk stratification. In order to obtain a precise diagnosis based on the criteria established on standard ECG, the "real" 12-lead ECG with ten electrodes is advocated.

  15. Technology-based vs. traditional instruction. A comparison of two methods for teaching the skill of performing a 12-lead ECG.

    PubMed

    Jeffries, Pamela R; Woolf, Shirley; Linde, Beverly

    2003-01-01

    The purpose of this study was to compare the effectiveness of an interactive, multimedia CD-ROM with traditional methods of teaching the skill of performing a 12-lead ECG. A randomized pre/posttest experimental design was used. Seventy-seven baccalaureate nursing students in a required, senior-level critical-care course at a large midwestern university were recruited for the study. Two teaching methods were compared. The traditional method included a self-study module, a brief lecture and demonstration by an instructor, and hands-on experience using a plastic manikin and a real 12-lead ECG machine in the learning laboratory. The second method covered the same content using an interactive, multimedia CD-ROM embedded with virtual reality and supplemented with a self-study module. There were no significant (p < .05) baseline differences in pretest scores between the two groups and no significant differences by group in cognitive gains, student satisfaction with their learning method, or perception of self-efficacy in performing the skill. Overall results indicated that both groups were satisfied with their instructional method and were similar in their ability to demonstrate the skill correctly on a live, simulated patient. This evaluation study is a beginning step to assess new and potentially more cost-effective teaching methods and their effects on student learning outcomes and behaviors, including the transfer of skill acquisition via a computer simulation to a real patient.

  16. ECG of the month. Electrocardiogram in a man with chronic kidney failure. ECG is abnormal and indicative of heart disease.

    PubMed

    Clancy, D Luke; Ali, Rehan; Lathia, Viral

    2012-01-01

    A 70-year-old man came to the Access to Primary Care Clinic at the Interim LSU Public Hospital because he had been told at another hospital that he needed a kidney doctor. The patient had a history of high blood pressure, type 2 diabetes mellitus, long-standing kidney disease, an above the knee amputation on the left, gout, a possible coronary stent procedure five years ago, and recently poor appetite and inability to care for himself. He had a long history of medical noncompliance and was taking no medications when he came to the hospital. He denied all cardiac symptoms, including chest discomfort. He was admitted to hospital because of a blood pressure of 240/110 mmHg, a serum creatinine of 6.0 mg/dL, and an estimated glomerular filtration rate of 11 mL/min - i.e., chronic kidney disease, stage V. His electrocardiogram was read by the computer as normal (Figure 1).

  17. Frequency Band Analysis of Electrocardiogram (ECG) Signals for Human Emotional State Classification Using Discrete Wavelet Transform (DWT)

    PubMed Central

    Murugappan, Murugappan; Murugappan, Subbulakshmi; Zheng, Bong Siao

    2013-01-01

    [Purpose] Intelligent emotion assessment systems have been highly successful in a variety of applications, such as e-learning, psychology, and psycho-physiology. This study aimed to assess five different human emotions (happiness, disgust, fear, sadness, and neutral) using heart rate variability (HRV) signals derived from an electrocardiogram (ECG). [Subjects] Twenty healthy university students (10 males and 10 females) with a mean age of 23 years participated in this experiment. [Methods] All five emotions were induced by audio-visual stimuli (video clips). ECG signals were acquired using 3 electrodes and were preprocessed using a Butterworth 3rd order filter to remove noise and baseline wander. The Pan-Tompkins algorithm was used to derive the HRV signals from ECG. Discrete wavelet transform (DWT) was used to extract statistical features from the HRV signals using four wavelet functions: Daubechies6 (db6), Daubechies7 (db7), Symmlet8 (sym8), and Coiflet5 (coif5). The k-nearest neighbor (KNN) and linear discriminant analysis (LDA) were used to map the statistical features into corresponding emotions. [Results] KNN provided the maximum average emotion classification rate compared to LDA for five emotions (sadness − 50.28%; happiness − 79.03%; fear − 77.78%; disgust − 88.69%; and neutral − 78.34%). [Conclusion] The results of this study indicate that HRV may be a reliable indicator of changes in the emotional state of subjects and provides an approach to the development of a real-time emotion assessment system with a higher reliability than other systems. PMID:24259846

  18. Detection and assessment of unstable angina using myocardial perfusion imaging: Comparison between technetium-99m sestamibi SPECT and 12-lead electrocardiogram

    SciTech Connect

    Gregoire, J.; Theroux, P. )

    1990-10-16

    Forty-five studies using technetium-99m (Tc-99m) sestamibi single photon emission computed tomography (SPECT) were performed on patients hospitalized for spontaneous chest pain suggestive of myocardial ischemia. The studies were done after an injection during an episode of chest pain and a repeated injection when the patients were free of pain. All patients were hospitalized with a presumed diagnosis of unstable angina, and none had evidence of a previous myocardial infarction. The presence of a perfusion defect observed with Tc-99m sestamibi injected during chest pain had a 96% sensitivity and a 79% specificity for the detection of significant coronary artery disease (stenosis greater than or equal to 50%) on subsequent angiography. When the criterion of a larger perfusion defect during pain compared to absence of pain was used, the sensitivity was 81% and the specificity was 84%. In contrast, transient electrocardiographic ischemic changes during pain had a sensitivity of 35% and a specificity of 68%; electrocardiographic changes during or outside episodes of chest pain had a sensitivity of 65% and a specificity of 63% for the diagnosis. Tc-99m sestamibi SPECT represents a reliable noninvasive diagnostic tool that could aid in the diagnosis of myocardial ischemia in patients with spontaneous chest pain and provide additional information to that provided by the electrocardiogram.

  19. Technology-Based vs. Traditional Instruction: A Comparison of Two Methods for Teaching the Skill of Performing a 12-Lead ECG.

    ERIC Educational Resources Information Center

    Jeffries, Pamela R.; Woolf, Shirley; Linde, Beverly

    2003-01-01

    Electrocardiogram technique was taught to 32 nursing students using a self-study module, lecture-demonstration, and hands-on learning laboratories and to 45 students using interactive multimedia CD-ROM with self-study module. Pre/postprogram data show satisfaction and score improvement was high for both, with no significant differences. (Contains…

  20. Evaluation of an algorithm based on single-condition decision rules for binary classification of 12-lead ambulatory ECG recording quality.

    PubMed

    Di Marco, Luigi Yuri; Duan, Wenfeng; Bojarnejad, Marjan; Zheng, Dingchang; King, Susan; Murray, Alan; Langley, Philip

    2012-09-01

    A new algorithm for classifying ECG recording quality based on the detection of commonly observed ECG contaminants which often render the ECG unusable for diagnostic purposes was evaluated. Contaminants (baseline drift, flat line, QRS-artefact, spurious spikes, amplitude stepwise changes, noise) were detected on individual leads from joint time-frequency analysis and QRS amplitude. Classification was based on cascaded single-condition decision rules (SCDR) that tested levels of contaminants against classification thresholds. A supervised learning classifier (SLC) was implemented for comparison. The SCDR and SLC algorithms were trained on an annotated database (Set A, PhysioNet Challenge 2011) of 'acceptable' versus 'unacceptable' quality recordings using the 'leave M out' approach with repeated random partitioning and cross-validation. Two training approaches were considered: (i) balanced, in which training records had equal numbers of 'acceptable' and 'unacceptable' recordings, (ii) unbalanced, in which the ratio of 'acceptable' to 'unacceptable' recordings from Set A was preserved. For each training approach, thresholds were calculated, and classification accuracy of the algorithm compared to other rule based algorithms and the SLC using a database for which classifications were unknown (Set B PhysioNet Challenge 2011). The SCDR algorithm achieved the highest accuracy (91.40%) compared to the SLC (90.40%) in spite of its simple logic. It also offers the advantage that it facilitates reporting of meaningful causes of poor signal quality to users.

  1. When Deriving the Spatial QRS-T Angle from the 12-lead ECG, which Transform is More Frank: Regression or Inverse Dower?

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Cortez, Daniel

    2010-01-01

    Our primary objective was to ascertain which commonly used 12-to-Frank-lead transformation yields spatial QRS-T angle values closest to those obtained from simultaneously collected true Frank-lead recordings. Simultaneous 12-lead and Frank XYZ-lead recordings were analyzed for 100 post-myocardial infarction patients and 50 controls. Relative agreement, with true Frank-lead results, of 12-to-Frank-lead transformed results for the spatial QRS-T angle using Kors regression versus inverse Dower was assessed via ANOVA, Lin s concordance and Bland-Altman plots. Spatial QRS-T angles from the true Frank leads were not significantly different than those derived from the Kors regression-related transformation but were significantly smaller than those derived from the inverse Dower-related transformation (P less than 0.001). Independent of method, spatial mean QRS-T angles were also always significantly larger than spatial maximum (peaks) QRS-T angles. Spatial QRS-T angles are best approximated by regression-related transforms. Spatial mean and spatial peaks QRS-T angles should also not be used interchangeably.

  2. [Brugada ECG].

    PubMed

    Richter, Sergio

    2015-09-01

    The Brugada syndrome (BrS) is characterized by a typical electrocardiogram (ECG) pattern of right precordial ST-segment elevation and the cardinal symptoms syncope and sudden cardiac death as clinical correlate of malignant ventricular arrhythmias in young adults without structural heart disease. The diagnosis of a type 1 Brugada-ECG is based on the documentation of a coved-type (≥ 0.2 mV) ST elevation followed by a negative T wave. The use of the ECG criteria postulated in the consensus of 2012 is helpful to distinguish between saddleback-type 2 (or type 3) J point/ST elevation and incomplete right bundle branch block. Spontaneous or drug-induced type 1 ST elevation can frequently only be detected in a single right precordial lead (V1 or V2), occurs sometimes together with a type 2 (or type 3) pattern in one and the same 12-lead ECG and can sometimes only be seen in modified right precordial leads. The ST elevation is less pronounced in females. Spontaneous and exercise-induced type 1 ST elevation, fragmented QRS complex, prolonged PR interval (> 200 ms), QRS prolongation in V2 (≥ 120 ms) and markers of an increased heterogeneity of ventricular repolarization are associated with an increased arrhythmic risk. The occurrence of spontaneous or dynamic type 1 ST elevation, a macroscopic T wave alternans or pronounced inferior (lateral) J point/ST elevation are signs of acute electrical instability.

  3. REPEATED TREATMENTS WITH DOXORUBICIN CAUSES ELECTROCARDIOGRAM (ECG) CHANGES AND INCREASED VENTRICULAR PREMATURE BEATS IN WISTAR-KYOTO (WKY) RATS

    EPA Science Inventory

    Doxorubicin (DOX) is a widely used anthracycline anti-neoplastic drug used to treat tumors. However it has been implicated in irreversible cardiac toxicity via the generation of a proxidant semiquinone free radical, which often results in cardiomyopathy and changes in the ECG. Ac...

  4. [Design of Electrocardiogram Signal Generator Based on Typical Electrocardiogram Database].

    PubMed

    Wang, Yuting; Wang, Xiaofei; Li, Dongshang; Liu, Guili

    2016-02-01

    Using LabVIEW programming and high-speed multifunction data acquisition card PCI-6251, we designed an electrocardiogram (ECG) signal generator based on Chinese typical ECG database. When the ECG signals are given off by the generator, the generator can also display the ECG information annotations at the same time, including waveform data and diagnostic results. It could be a useful assisting tool of ECG automatic diagnose instruments.

  5. [Design of Electrocardiogram Signal Generator Based on Typical Electrocardiogram Database].

    PubMed

    Wang, Yuting; Wang, Xiaofei; Li, Dongshang; Liu, Guili

    2016-02-01

    Using LabVIEW programming and high-speed multifunction data acquisition card PCI-6251, we designed an electrocardiogram (ECG) signal generator based on Chinese typical ECG database. When the ECG signals are given off by the generator, the generator can also display the ECG information annotations at the same time, including waveform data and diagnostic results. It could be a useful assisting tool of ECG automatic diagnose instruments. PMID:27382747

  6. Automatic learning of rules. A practical example of using artificial intelligence to improve computer-based detection of myocardial infarction and left ventricular hypertrophy in the 12-lead ECG.

    PubMed

    Kaiser, W; Faber, T S; Findeis, M

    1996-01-01

    The authors developed a computer program that detects myocardial infarction (MI) and left ventricular hypertrophy (LVH) in two steps: (1) by extracting parameter values from a 10-second, 12-lead electrocardiogram, and (2) by classifying the extracted parameter values with rule sets. Every disease has its dedicated set of rules. Hence, there are separate rule sets for anterior MI, inferior MI, and LVH. If at least one rule is satisfied, the disease is said to be detected. The computer program automatically develops these rule sets. A database (learning set) of healthy subjects and patients with MI, LVH, and mixed MI+LVH was used. After defining the rule type, initial limits, and expected quality of the rules (positive predictive value, minimum number of patients), the program creates a set of rules by varying the limits. The general rule type is defined as: disease = lim1l < p1 < or = lim1u and lim2l < p2 < or = lim2u and ... limnl < pn < or = limnu. When defining the rule types, only the parameters (p1 ... pn) that are known as clinical electrocardiographic criteria (amplitudes [mV] of Q, R, and T waves and ST-segment; duration [ms] of Q wave; frontal angle [degrees]) were used. This allowed for submitting the learned rule sets to an independent investigator for medical verification. It also allowed the creation of explanatory texts with the rules. These advantages are not offered by the neurons of a neural network. The learned rules were checked against a test set and the following results were obtained: MI: sensitivity 76.2%, positive predictive value 98.6%; LVH: sensitivity 72.3%, positive predictive value 90.9%. The specificity ratings for MI are better than 98%; for LVH, better than 90%.

  7. Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

    2004-01-01

    Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

  8. Arrhythmia Identification with Two-Lead Electrocardiograms Using Artificial Neural Networks and Support Vector Machines for a Portable ECG Monitor System

    PubMed Central

    Liu, Shing-Hong; Cheng, Da-Chuan; Lin, Chih-Ming

    2013-01-01

    An automatic configuration that can detect the position of R-waves, classify the normal sinus rhythm (NSR) and other four arrhythmic types from the continuous ECG signals obtained from the MIT-BIH arrhythmia database is proposed. In this configuration, a support vector machine (SVM) was used to detect and mark the ECG heartbeats with raw signals and differential signals of a lead ECG. An algorithm based on the extracted markers segments waveforms of Lead II and V1 of the ECG as the pattern classification features. A self-constructing neural fuzzy inference network (SoNFIN) was used to classify NSR and four arrhythmia types, including premature ventricular contraction (PVC), premature atrium contraction (PAC), left bundle branch block (LBBB), and right bundle branch block (RBBB). In a real scenario, the classification results show the accuracy achieved is 96.4%. This performance is suitable for a portable ECG monitor system for home care purposes. PMID:23303379

  9. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    Rahman, Atiar

    2006-01-01

    Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  10. High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

  11. Effective Electrocardiogram Steganography Based on Coefficient Alignment.

    PubMed

    Yang, Ching-Yu; Wang, Wen-Fong

    2016-03-01

    This study presents two types of data hiding methods based on coefficient alignment for electrocardiogram (ECG) signals, namely, lossy and reversible ECG steganographys. The lossy method is divided into high-quality and high-capacity ECG steganography, both of which are capable of hiding confidential patient data in ECG signals. The reversible data hiding method can not only hide secret messages but also completely restore the original ECG signal after bit extraction. Simulations confirmed that the perceived quality generated by the lossy ECG steganography methods was good, while hiding capacity was acceptable. In addition, these methods have a certain degree of robustness, which is rare in conventional ECG stegangraphy schemes. Moreover, the proposed reversible ECG steganography method can not only successfully extract hidden messages but also completely recover the original ECG data.

  12. Role of the surface electrocardiogram in developing countries.

    PubMed

    Varma, Niraj

    2010-01-01

    nations.) Electrocardiogram interpretation also needs to account for different "normal" values in different ethnic groups: there is a surprising dearth of such data in groups other than African Americans. This is essential for interpretation of abnormality. Development of additional sophisticated analyses from ECG data may guide more selective use of expensive and invasive therapies. For example, risk stratification for defibrillator implant may be enhanced by use of T-wave alternans and heart rate variability. In China, ischemia monitoring with 12-lead Holters is performed due to lack of availability of a chest pain clinic. Innovative measures in electrocardiography are required for improving health care delivery in developing nations.

  13. [Transponder ECG].

    PubMed

    Bedrich, M R

    1997-04-01

    Apart from X-rays, the electrocardiogram (ECG) is probably the most frequently employed routine investigation. The 24-hour (Holter) ECG is a valuable diagnostic tool both for the general practitioner and the cardiologist. For the patient, the procedure can be experienced as something of a nuisance during the course of his/her normal life. Not least of the reasons for this are the leads connecting the electrodes to the device, which impair the movements of the patient's trunk. In addition, the patient feels constrained by a desire to avoid the disconnection of the electrodes by uncontrolled movements. Despite positive findings obtained by other means, this situation often leads to false negative results, making repetition of the procedure at some later date.

  14. Synergistic effect of polymorphisms of paraoxonase gene cluster and arsenic exposure on electrocardiogram abnormality.

    PubMed

    Liao, Ya-Tang; Li, Wan-Fen; Chen, Chien-Jen; Prineas, Ronald J; Chen, Wei J; Zhang, Zhu-Ming; Sun, Chien-Wen; Wang, Shu-Li

    2009-09-01

    Arsenic has been linked to increased prevalence of cancer and cardiovascular disease (CVD), but the long-term impact of arsenic exposure remains unclear. Human paraoxonase (PON1) is a high-density lipoprotein-associated antioxidant enzyme which hydrolyzes oxidized lipids and is thought to be protective against atherosclerosis, but evidence remains limited to case-control studies. Only recently have genes encoding enzymes responsible for arsenic metabolism, such as AS3MT and GSTO, been cloned and characterized. This study was designed to evaluate the synergistic interaction of genetic factors and arsenic exposure on electrocardiogram abnormality. A total of 216 residents from three tap water implemented villages of previous arseniasis-hyperendemic regions in Taiwan were prospectively followed for an average of 8 years. For each resident, a 12-lead conventional electrocardiogram (ECG) was recorded and coded by Minnesota Code standard criteria. Eight functional polymorphisms of PON1, PON2, AS3MT, GSTO1, and GSTO2 were examined for genetic susceptibility to ECG abnormality. Among 42 incident cases with ECG deterioration identified among 121 baseline-normal subjects, arsenic exposure was significantly correlated with incidence of ECG abnormality. In addition, polymorphisms in two paraoxonase genes were also found associated with the incidence of ECG abnormality. A haplotype R-C-S constituted by polymorphisms of PON1 Q192R, -108C/T and PON2 C311S was linked to the increased risk. Subjects exposed to high levels of As (cumulative As exposure >14.7 ppm-year or drinking artesian well water >21 years) and carrying the R-C-S haplotype had significantly increased risks for ECG abnormality over those with only one risk factor. Results of this study showed a long-term arsenic effect on ECG abnormality and significant gene-gene and gene-environment interactions linked to the incidence of CVD. This finding might have important implications for a novel and potentially useful

  15. Synergistic effect of polymorphisms of paraoxonase gene cluster and arsenic exposure on electrocardiogram abnormality

    SciTech Connect

    Liao, Y.-T.; Li, W.-F.; Chen, C.-J.; Prineas, Ronald J.; Chen, Wei J.; Zhang Zhuming; Sun, C.-W.; Wang, S.-L.

    2009-09-01

    Arsenic has been linked to increased prevalence of cancer and cardiovascular disease (CVD), but the long-term impact of arsenic exposure remains unclear. Human paraoxonase (PON1) is a high-density lipoprotein-associated antioxidant enzyme which hydrolyzes oxidized lipids and is thought to be protective against atherosclerosis, but evidence remains limited to case-control studies. Only recently have genes encoding enzymes responsible for arsenic metabolism, such as AS3MT and GSTO, been cloned and characterized. This study was designed to evaluate the synergistic interaction of genetic factors and arsenic exposure on electrocardiogram abnormality. A total of 216 residents from three tap water implemented villages of previous arseniasis-hyperendemic regions in Taiwan were prospectively followed for an average of 8 years. For each resident, a 12-lead conventional electrocardiogram (ECG) was recorded and coded by Minnesota Code standard criteria. Eight functional polymorphisms of PON1, PON2, AS3MT, GSTO1, and GSTO2 were examined for genetic susceptibility to ECG abnormality. Among 42 incident cases with ECG deterioration identified among 121 baseline-normal subjects, arsenic exposure was significantly correlated with incidence of ECG abnormality. In addition, polymorphisms in two paraoxonase genes were also found associated with the incidence of ECG abnormality. A haplotype R-C-S constituted by polymorphisms of PON1 Q192R, -108C/T and PON2 C311S was linked to the increased risk. Subjects exposed to high levels of As (cumulative As exposure > 14.7 ppm-year or drinking artesian well water > 21 years) and carrying the R-C-S haplotype had significantly increased risks for ECG abnormality over those with only one risk factor. Results of this study showed a long-term arsenic effect on ECG abnormality and significant gene-gene and gene-environment interactions linked to the incidence of CVD. This finding might have important implications for a novel and potentially useful

  16. Development of a portable Linux-based ECG measurement and monitoring system.

    PubMed

    Tan, Tan-Hsu; Chang, Ching-Su; Huang, Yung-Fa; Chen, Yung-Fu; Lee, Cheng

    2011-08-01

    This work presents a portable Linux-based electrocardiogram (ECG) signals measurement and monitoring system. The proposed system consists of an ECG front end and an embedded Linux platform (ELP). The ECG front end digitizes 12-lead ECG signals acquired from electrodes and then delivers them to the ELP via a universal serial bus (USB) interface for storage, signal processing, and graphic display. The proposed system can be installed anywhere (e.g., offices, homes, healthcare centers and ambulances) to allow people to self-monitor their health conditions at any time. The proposed system also enables remote diagnosis via Internet. Additionally, the system has a 7-in. interactive TFT-LCD touch screen that enables users to execute various functions, such as scaling a single-lead or multiple-lead ECG waveforms. The effectiveness of the proposed system was verified by using a commercial 12-lead ECG signal simulator and in vivo experiments. In addition to its portability, the proposed system is license-free as Linux, an open-source code, is utilized during software development. The cost-effectiveness of the system significantly enhances its practical application for personal healthcare.

  17. Three-Dimensional Visualization of Myocardial Ischemia Based on the Standard Twelve-Lead Electrocardiogram

    PubMed Central

    Ruixia, Tian; Xun, Chen

    2016-01-01

    A novel method was proposed for transforming the ischemic information in the 12-lead electrocardiogram (ECG) into the pseudo-color pattern displayed on a 3D heart model based on the projection of a ST injury vector in this study. The projection of the ST injury vector at a point on the heart surface was used for identifying the presence of myocardial ischemia by the difference between the projection value and the detection threshold. Supposing that myocardial ischemia was uniform and continuous, the location and range of myocardial ischemia could be accurately calculated and visually displayed in a color-encoding way. The diagnoses of the same patient were highly consistent (kappa coefficient k = 0.9030) between the proposed method used by ordinary people lacking medical knowledge and the standard 12-lead ECG used by experienced cardiologists. In addition, the diagnostic accuracy of the proposed method was further confirmed by the coronary angiography. The results of this study provide a new way to promote the development of the 3D visualization of the standard 12-lead ECG, which has a great help for inexperienced doctors or ordinary family members in their diagnosis of patients with myocardial ischemia. PMID:27433278

  18. A combined application of lossless and lossy compression in ECG processing and transmission via GSM-based SMS.

    PubMed

    Mukhopadhyay, S K; Mitra, S; Mitra, M

    2015-02-01

    This paper presents a software-based scheme for reliable and robust Electrocardiogram (ECG) data compression and its efficient transmission using Second Generation (2G) Global System for Mobile Communication (GSM) based Short Message Service (SMS). To achieve a firm lossless compression in high standard deviating QRS complex regions and an acceptable lossy compression in the rest of the signal, two different algorithms have been used. The combined compression module is such that it outputs only American Standard Code for Information Interchange (ASCII) characters and, hence, SMS service is found to be most suitable for transmitting the compressed signal. At the receiving end, the ECG signal is reconstructed using just the reverse algorithm. The module has been tested to all the 12 leads of different types of ECG signals (healthy and abnormal) collected from the PTB Diagnostic ECG Database. The compression algorithm achieves an average compression ratio of ∼22.51, without any major alteration of clinical morphology. PMID:25534118

  19. Association between obesity and ECG variables in children and adolescents: A cross-sectional study

    PubMed Central

    SUN, GUO-ZHE; LI, YANG; ZHOU, XING-HU; GUO, XIAO-FAN; ZHANG, XIN-GANG; ZHENG, LI-QIANG; LI, YUAN; JIAO, YUN-DI; SUN, YING-XIAN

    2013-01-01

    Obesity exhibits a wide variety of electrocardiogram (ECG) abnormalities in adults, which often lead to cardiovascular events. However, there is currently no evidence of an association between obesity and ECG variables in children and adolescents. The present study aimed to explore the associations between obesity and ECG intervals and axes in children and adolescents. A cross-sectional observational study of 5,556 students aged 5–18 years was performed. Anthropometric data, blood pressure and standard 12-lead ECGs were collected for each participant. ECG variables were measured manually based on the temporal alignment of simultaneous 12 leads using a CV200 ECG Work Station. Overweight and obese groups demonstrated significantly longer PR intervals, wider QRS durations and leftward shifts of frontal P-wave, QRS and T-wave axes, while the obese group also demonstrated significantly higher heart rates, compared with normal weight groups within normotensive or hypertensive subjects (P<0.05). Abdominal obesity was also associated with longer PR intervals, wider QRS duration and a leftward shift of frontal ECG axes compared with normal waist circumference (WC) within normotensive or hypertensive subjects (P<0.05). Gender was a possible factor affecting the ECG variables. Furthermore, the ECG variables, including PR interval, QRS duration and frontal P-wave, QRS and T-wave axes, were significantly linearly correlated with body mass index, WC and waist-to-height ratio adjusted for age, gender, ethnicity and blood pressure. However, there was no significant association between obesity and the corrected QT interval (P>0.05). The results of the current study indicate that in children and adolescents, general and abdominal obesity is associated with longer PR intervals, wider QRS duration and a leftward shift of frontal P-wave, QRS and T-wave axes, independent of age, gender, ethnicity and blood pressure. PMID:24255675

  20. Programmable ECG Waveform

    PubMed Central

    Le Huy, P.; Yvroud, E.; Gilgenkrantz, J.M.; Baille, N.; Aliot, E.

    1984-01-01

    In this paper, the simulation of an electrocardiogram using a CMOS microprocessor is described. The programmability has been made accessible to every user. All inherent parameters of different waves in an ECG, such as amplitude, slope, duration can be independently modified by software. Thus, the testing of some sophisticated devices may be easily performed.

  1. Hybrid ECG signal conditioner

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Circuit with high common-mode rejection has ability to filter and amplify accepted analog electrocardiogram (ECG) signals of varying amplitude, shape, and polarity. In addition, low power circuit develops standardized pulses that can be counted and averaged by heart/breath rate processor.

  2. [The electrocardiogram in the paediatric age group].

    PubMed

    Sanches, M; Coelho, A; Oliveira, E; Lopes, A

    2014-09-01

    A properly interpreted electrocardiogram (ECG) provides important information and is an inexpensive and easy test to perform. It continues to be the method of choice for the diagnosis of arrhythmias. Although the principles of cardiac electrophysiology are the same, there are anatomical and physiological age-dependent changes which produce specific alterations in the paediatric ECG, and which may be misinterpreted as pathological. The intention of this article is to address in a systematic way the most relevant aspects of the paediatric ECG, to propose a possible reading scheme of the ECG and to review the electrocardiograph tracings most frequently found in the paediatric age group.

  3. Advanced ECG in 2016: is there more than just a tracing?

    PubMed

    Reichlin, Tobias; Abächerli, Roger; Twerenbold, Raphael; Kühne, Michael; Schaer, Beat; Müller, Christian; Sticherling, Christian; Osswald, Stefan

    2016-01-01

    The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is critical for evidence-based management of patients with most cardiovascular conditions, including patients with acute myocardial infarction, suspected chronic cardiac ischaemia, cardiac arrhythmias, heart failure and implantable cardiac devices. In contrast to many other techniques in cardiology, the ECG is simple, small, mobile, universally available and cheap, and therefore particularly attractive. Standard ECG interpretation mainly relies on direct visual assessment. The progress in biomedical computing and signal processing, and the available computational power offer fascinating new options for ECG analysis relevant to all fields of cardiology. Several digital ECG markers and advanced ECG technologies have shown promise in preliminary studies. This article reviews promising novel surface ECG technologies in three different fields. (1) For the detection of myocardial ischaemia and infarction, QRS morphology feature analysis, the analysis of high frequency QRS components (HF-QRS) and methods using vectorcardiography as well as ECG imaging are discussed. (2) For the identification and management of patients with cardiac arrhythmias, methods of advanced P-wave analysis are discussed and the concept of ECG imaging for noninvasive localisation of cardiac arrhythmias is presented. (3) For risk stratification of sudden cardiac death and the selection of patients for medical device therapy, several novel markers including an automated QRS-score for scar quantification, the QRS-T angle or the T-wave peak-to-end-interval are discussed. Despite the existing preliminary data, none of the advanced ECG markers and technologies has yet accomplished the transition into clinical practice. Further refinement of these technologies and broader validation in large unselected patient cohorts are the critical next step needed to facilitate translation of advanced ECG technologies

  4. Advanced ECG in 2016: is there more than just a tracing?

    PubMed

    Reichlin, Tobias; Abächerli, Roger; Twerenbold, Raphael; Kühne, Michael; Schaer, Beat; Müller, Christian; Sticherling, Christian; Osswald, Stefan

    2016-01-01

    The 12-lead electrocardiogram (ECG) is the most frequently used technology in clinical cardiology. It is critical for evidence-based management of patients with most cardiovascular conditions, including patients with acute myocardial infarction, suspected chronic cardiac ischaemia, cardiac arrhythmias, heart failure and implantable cardiac devices. In contrast to many other techniques in cardiology, the ECG is simple, small, mobile, universally available and cheap, and therefore particularly attractive. Standard ECG interpretation mainly relies on direct visual assessment. The progress in biomedical computing and signal processing, and the available computational power offer fascinating new options for ECG analysis relevant to all fields of cardiology. Several digital ECG markers and advanced ECG technologies have shown promise in preliminary studies. This article reviews promising novel surface ECG technologies in three different fields. (1) For the detection of myocardial ischaemia and infarction, QRS morphology feature analysis, the analysis of high frequency QRS components (HF-QRS) and methods using vectorcardiography as well as ECG imaging are discussed. (2) For the identification and management of patients with cardiac arrhythmias, methods of advanced P-wave analysis are discussed and the concept of ECG imaging for noninvasive localisation of cardiac arrhythmias is presented. (3) For risk stratification of sudden cardiac death and the selection of patients for medical device therapy, several novel markers including an automated QRS-score for scar quantification, the QRS-T angle or the T-wave peak-to-end-interval are discussed. Despite the existing preliminary data, none of the advanced ECG markers and technologies has yet accomplished the transition into clinical practice. Further refinement of these technologies and broader validation in large unselected patient cohorts are the critical next step needed to facilitate translation of advanced ECG technologies

  5. 77 FR 6127 - Submission of Extended Digital Electrocardiogram Waveform Data; Notice of Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... meeting to consider changes in how digital electrocardiogram (ECG) data gathered to assess a drug's... Health Level- 7 (HL7) Annotated ECG standard data format--used by the ECG warehouse-- will be presented. The new data format is intended to facilitate electronic submission and sharing of ECG data...

  6. A new algorithm to diagnose atrial ectopic origin from multi lead ECG systems--insights from 3D virtual human atria and torso.

    PubMed

    Alday, Erick A Perez; Colman, Michael A; Langley, Philip; Butters, Timothy D; Higham, Jonathan; Workman, Antony J; Hancox, Jules C; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms. PMID

  7. A new algorithm to diagnose atrial ectopic origin from multi lead ECG systems--insights from 3D virtual human atria and torso.

    PubMed

    Alday, Erick A Perez; Colman, Michael A; Langley, Philip; Butters, Timothy D; Higham, Jonathan; Workman, Antony J; Hancox, Jules C; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms.

  8. A New Algorithm to Diagnose Atrial Ectopic Origin from Multi Lead ECG Systems - Insights from 3D Virtual Human Atria and Torso

    PubMed Central

    Alday, Erick A. Perez; Colman, Michael A.; Langley, Philip; Butters, Timothy D.; Higham, Jonathan; Workman, Antony J.; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Rapid atrial arrhythmias such as atrial fibrillation (AF) predispose to ventricular arrhythmias, sudden cardiac death and stroke. Identifying the origin of atrial ectopic activity from the electrocardiogram (ECG) can help to diagnose the early onset of AF in a cost-effective manner. The complex and rapid atrial electrical activity during AF makes it difficult to obtain detailed information on atrial activation using the standard 12-lead ECG alone. Compared to conventional 12-lead ECG, more detailed ECG lead configurations may provide further information about spatio-temporal dynamics of the body surface potential (BSP) during atrial excitation. We apply a recently developed 3D human atrial model to simulate electrical activity during normal sinus rhythm and ectopic pacing. The atrial model is placed into a newly developed torso model which considers the presence of the lungs, liver and spinal cord. A boundary element method is used to compute the BSP resulting from atrial excitation. Elements of the torso mesh corresponding to the locations of the placement of the electrodes in the standard 12-lead and a more detailed 64-lead ECG configuration were selected. The ectopic focal activity was simulated at various origins across all the different regions of the atria. Simulated BSP maps during normal atrial excitation (i.e. sinoatrial node excitation) were compared to those observed experimentally (obtained from the 64-lead ECG system), showing a strong agreement between the evolution in time of the simulated and experimental data in the P-wave morphology of the ECG and dipole evolution. An algorithm to obtain the location of the stimulus from a 64-lead ECG system was developed. The algorithm presented had a success rate of 93%, meaning that it correctly identified the origin of atrial focus in 75/80 simulations, and involved a general approach relevant to any multi-lead ECG system. This represents a significant improvement over previously developed algorithms. PMID

  9. Fast data-driven calibration of a cardiac electrophysiology model from images and ECG.

    PubMed

    Zettinig, Oliver; Mansi, Tommaso; Georgescu, Bogdan; Kayvanpour, Elham; Sedaghat-Hamedani, Farbod; Amr, Ali; Haas, Jan; Steen, Henning; Meder, Benjamin; Katus, Hugo; Navab, Nassir; Kamen, Ali; Comaniciul, Dorin

    2013-01-01

    Recent advances in computational electrophysiology (EP) models make them attractive for clinical use. We propose a novel data-driven approach to calibrate an EP model from standard 12-lead electrocardiograms (ECG), which are in contrast to invasive or dense body surface measurements widely available in clinical routine. With focus on cardiac depolarization, we first propose an efficient forward model of ECG by coupling a mono-domain, Lattice-Boltzmann model of cardiac EP to a boundary element formulation of body surface potentials. We then estimate a polynomial regression to predict myocardium, left ventricle and right ventricle endocardium electrical diffusion from QRS duration and ECG electrical axis. Training was performed on 4,200 ECG simulations, calculated in aproximately 3 s each, using different diffusion parameters on 13 patient geometries. This allowed quantifying diffusion uncertainty for given ECG parameters due to the ill-posed nature of the ECG problem. We show that our method is able to predict myocardium diffusion within the uncertainty range, yielding a prediction error of less than 5 ms for QRS duration and 2 degree for electrical axis. Prediction results compared favorably with those obtained with a standard optimization procedure, while being 60 times faster. Our data-driven model can thus constitute an efficient preliminary step prior to more refined EP personalization. PMID:24505642

  10. Ambulance 12-lead electrocardiography transmission via cell phone technology to cardiologists.

    PubMed

    Hsieh, Jui-Chien; Lin, Bo-Xuan; Wu, Feng-Ren; Chang, Pei-Chann; Tsuei, Yi-Wei; Yang, Chung-Chi

    2010-10-01

    This study demonstrates transmission of 12-lead electrocardiography (ECG) in an ambulance to the cell phone of the attendant emergency medical technician and then to the hospital and to cell phones of off-site cardiologists. The emergency medical technician cell phone receives Extensible Markup Language files generated by a Phillips Extensible Markup Language ECG instrument via Wi-Fi-based wireless network and then sends them to an ECG-processing server at the hospital over the mobile telephone network. After reducing ECG noises and artifacts, the server converts files to Digital Imaging and Communications in Medicine-based ECG reports stored in Picture Archiving and Communication System. These reports are sent to the cell phones of off-site cardiologists. Consequently, on-site Emergency Department physicians and off-site cardiologists can discuss ECG reports via Picture Archiving and Communication System on their computers or cell phones to prepare for the most appropriate treatment while the patient is on the way to the hospital. In conclusion, this 12-lead ECG transmission e-technology expands the functions of a 12-lead ECG instrument and facilitates more efficient prehospital cardiac care.

  11. Assessment of a single monomorphic ventricular ectopy from the right ventricular outflow tract in standard and high resolution electrocardiogram

    PubMed Central

    Kosiński, Adam; Dąbrowska-Kugacka, Alicja; Lewicka-Nowak, Ewa; Dudziak, Maria; Grzybiak, Marek; Raczak, Grzegorz

    2010-01-01

    Introduction High-resolution electrocardiography (ECG-CREM) is a method based on digital electrocardiography. In order to facilitate the interpretation of the Crem records the technique of vectorcardiography was used. In comparison the origin of the ventricular premature complexes (VPCs) could be estimated based on a standard 12-lead electrocardiogram. The aim of the study was to assess the point of origin of the VPCs in ECG-CREM and correlate it with standard electrocardiography (ECG-Stand). Material and methods Our study included 26 patients (16 females, 10 males), aged 51-83 years (avg. 58.1 ±12.3), who presented with recurrent, during at least 6 months’ observation, VPCs. The point of origin of VPCs was compared in both methods. Results The performed analysis of collected ECG-Stand records revealed the presence of arrhythmogenic focal points in six different locations (1, 3, 5, 7, 8, 9). However, we did not affirm their presence in points 2,4,6. They were most commonly located in RVOT zones 8 (30.7%), 9 (23.0%), 5 (23.0%), and most seldom in zones 1, 3, 7 (7.6% each). In the simultaneous record of ECG-CREM with a single VPC it was confirmed that the FPb zone was activated the most frequently (40.0%); the next in relation to frequency were SD and ST (20.0%). Less frequent VPCs have their origin in Crem zones SP, FPa and SB (6.6%). Conclusions Electrocardiogram of high signal resolution (ECG-CREM) might be useful in recognition of the origin of ventricular premature complexes from RVOT. PMID:22419930

  12. The electrocardiogram in Down syndrome.

    PubMed

    Caro, Milagros; Conde, Diego; Pérez-Riera, Andrés R; de Almeida, Adail P; Baranchuk, Adrian

    2015-01-01

    Down syndrome is the most common chromosomal abnormality, with an incidence of one case in every 650 live births. It is strongly associated with heart disease, which constitutes the main cause of mortality during the first 2 years of life in this population. Most of the cardiac abnormalities in patients with Down syndrome can be suspected by analysing the surface 12-lead ECG. The purpose of this systematic review was to analyse all available published material on surface ECG and cardiac rhythm and conduction abnormalities in patients with Down syndrome to facilitate the search to the clinical cardiologist and paediatrician.

  13. The ECG as decision support in STEMI.

    PubMed

    Ripa, Maria Sejersten

    2012-03-01

    The electrocardiogram (ECG) can be used for determining the presence, location and extent of jeopardized myocardium during acute coronary occlusion. Accordingly, the ECG has become essential in the treatment of patients with acute coronary syndrome (ACS). This thesis aims at optimizing the decision support, provided by the ECG, for choosing the best treatment strategy in the individual patient with ST-segment elevation acute myocardial infarction (STEMI). ECG recorded in the prehospital setting has become the standard of care in many communities, but to achieve the full advantage of this early approach it is important that the ECG is recorded from accurately placed electrodes to produce an ECG that resembles the standard 12-lead ECG. Accurate electrode placement is difficult especially in the acute setting, and we investigated an alternative lead system with fewer electrodes in easily identified positions. We showed that the system produced waveforms similar to the standard 12-lead ECG. However, occasional diagnostic errors were seen, compromising general acceptance of the system. Once the ECG has been recorded a decision regarding triage must be made on the basis of a correct ECG diagnosis. We found that trained paramedics can diagnose STEMI correctly in patients without ECG confounding factors, while the presence of ECG confounding factors decreased their ability substantially. Consequently, since many patients do present with ECG confounding factors, transmission to an on-call cardiologist for an early correct diagnosis is needed. We showed that time to pPCI was reduced by more than 1 hour by transmitting prehospital ECG to a cardiologist's handheld device for diagnosis, triage, and activation of the catheterization laboratory when needed. The optimal treatment strategy is dependent on the duration of ischemia however patient information is often inaccurate. Accordingly, it would be advantageous if the first available ECG can help identify patients who will

  14. ECG data compression by modeling.

    PubMed Central

    Madhukar, B.; Murthy, I. S.

    1992-01-01

    This paper presents a novel algorithm for data compression of single lead Electrocardiogram (ECG) data. The method is based on Parametric modeling of the Discrete Cosine Transformed ECG signal. Improved high frequency reconstruction is achieved by separately modeling the low and the high frequency regions of the transformed signal. Differential Pulse Code Modulation is applied on the model parameters to obtain a further increase in the compression. Compression ratios up to 1:40 were achieved without significant distortion. PMID:1482940

  15. [A history of the electrocardiogram].

    PubMed

    Johansson, B W

    2001-01-01

    The discoveries by Galvani and Volta of electricity and its effects fascinated the intellectual world, but it was not until 1856 that Köllicker and Müller discovered that the heart muscle could produce electric activity. Muirhead in London recorded the first electrocardiogram (ECG) in man in 1869 or 1870 with a siphon instrument and Waller in 1887 with a capillary electrometer. Einthoven's string galvanometer was a breakthrough. As early as five years after his publication Einthoven introduced "Le Télecardiograme" in 1906 by which a cable connected his instrument to a hospital one and a half kilometres away. The string galvanometer produced precise ECG recordings but it was like the opera primadonnas of the time, voluminous and unpredictable. Rune Elmqvist developed the direct-writing inkjet recorder, first demonstrated at the Congress of Cardiology in Paris, 1950. Ohnell's studies of preexcitation, to which the WPW-syndrome belongs, were important. After the initial focus on arrhythmias, ECG became more and more used in the diagnosis of myocardial ischaemia and coronary heart disease. To refine this diagnosis the hypoxaemia (breathing air with low oxygen content) test, as well as the exercise test and other stress tests were introduced. Vectorcardiography displays the spatial movements of the electrical forces generated by the heart. Long-term ECG registration with a portable tape recorder is important both for the diagnosis of arrhythmias and myocardial ischaemia. Foetal and comparative ECG have provided important clinical and scientific information. PMID:11848076

  16. The history, hotspots, and trends of electrocardiogram.

    PubMed

    Yang, Xiang-Lin; Liu, Guo-Zhen; Tong, Yun-Hai; Yan, Hong; Xu, Zhi; Chen, Qi; Liu, Xiang; Zhang, Hong-Hao; Wang, Hong-Bo; Tan, Shao-Hua

    2015-07-01

    The electrocardiogram (ECG) has broad applications in clinical diagnosis and prognosis of cardiovascular disease. Many researchers have contributed to its progressive development. To commemorate those pioneers, and to better study and promote the use of ECG, we reviewed and present here a systematic introduction about the history, hotspots, and trends of ECG. In the historical part, information including the invention, improvement, and extensive applications of ECG, such as in long QT syndrome (LQTS), angina, and myocardial infarction (MI), are chronologically presented. New technologies and applications from the 1990s are also introduced. In the second part, we use the bibliometric analysis method to analyze the hotspots in the field of ECG-related research. By using total citations and year-specific total citations as our main criteria, four key hotspots in ECG-related research were identified from 11 articles, including atrial fibrillation, LQTS, angina and MI, and heart rate variability. Recent studies in those four areas are also reported. In the final part, we discuss the future trends concerning ECG-related research. The authors believe that improvement of the ECG instrumentation, big data mining for ECG, and the accuracy of diagnosis and application will be areas of continuous concern. PMID:26345622

  17. The history, hotspots, and trends of electrocardiogram

    PubMed Central

    Yang, Xiang-Lin; Liu, Guo-Zhen; Tong, Yun-Hai; Yan, Hong; Xu, Zhi; Chen, Qi; Liu, Xiang; Zhang, Hong-Hao; Wang, Hong-Bo; Tan, Shao-Hua

    2015-01-01

    The electrocardiogram (ECG) has broad applications in clinical diagnosis and prognosis of cardiovascular disease. Many researchers have contributed to its progressive development. To commemorate those pioneers, and to better study and promote the use of ECG, we reviewed and present here a systematic introduction about the history, hotspots, and trends of ECG. In the historical part, information including the invention, improvement, and extensive applications of ECG, such as in long QT syndrome (LQTS), angina, and myocardial infarction (MI), are chronologically presented. New technologies and applications from the 1990s are also introduced. In the second part, we use the bibliometric analysis method to analyze the hotspots in the field of ECG-related research. By using total citations and year-specific total citations as our main criteria, four key hotspots in ECG-related research were identified from 11 articles, including atrial fibrillation, LQTS, angina and MI, and heart rate variability. Recent studies in those four areas are also reported. In the final part, we discuss the future trends concerning ECG-related research. The authors believe that improvement of the ECG instrumentation, big data mining for ECG, and the accuracy of diagnosis and application will be areas of continuous concern. PMID:26345622

  18. Electrocardiogram beat detection enhancement using independent component analysis.

    PubMed

    Kuzilek, Jakub; Lhotska, Lenka

    2013-06-01

    Beat detection is a basic and fundamental step in electrocardiogram (ECG) processing. In many ECG applications strong artifacts from biological or technical sources could appear and cause distortion of ECG signals. Beat detection algorithm desired property is to avoid these distortions and detect beats in any situation. Our developed method is an extension of Christov's beat detection algorithm, which detects beat using combined adaptive threshold on transformed ECG signal (complex lead). Our offline extension adds estimation of independent components of measured signal into the transformation of ECG creating a signal called complex component, which enhances ECG activity and enables beat detection in presence of strong noises. This makes the beat detection algorithm much more robust in cases of unpredictable noise appearances, typical for holter ECGs and telemedicine applications of ECG. We compared our algorithm with the performance of our implementation of the Christov's and Hamilton's beat detection algorithm.

  19. Threshold-based system for noise detection in multilead ECG recordings.

    PubMed

    Jekova, Irena; Krasteva, Vessela; Christov, Ivaylo; Abächerli, Roger

    2012-09-01

    This paper presents a system for detection of the most common noise types seen on the electrocardiogram (ECG) in order to evaluate whether an episode from 12-lead ECG is reliable for diagnosis. It implements criteria for estimation of the noise corruption level in specific frequency bands, aiming to identify the main sources of ECG quality disruption, such as missing signal or limited dynamics of the QRS components above 4 Hz; presence of high amplitude and steep artifacts seen above 1 Hz; baseline drift estimated at frequencies below 1 Hz; power-line interference in a band ±2 Hz around its central frequency; high-frequency and electromyographic noises above 20 Hz. All noise tests are designed to process the ECG series in the time domain, including 13 adjustable thresholds for amplitude and slope criteria which are evaluated in adjustable time intervals, as well as number of leads. The system allows flexible extension toward application-specific requirements for the noise levels in acceptable quality ECGs. Training of different thresholds' settings to determine different positive noise detection rates is performed with the annotated set of 1000 ECGs from the PhysioNet database created for the Computing in Cardiology Challenge 2011. Two implementations are highlighted on the receiver operating characteristic (area 0.968) to fit to different applications. The implementation with high sensitivity (Se = 98.7%, Sp = 80.9%) appears as a reliable alarm when there are any incidental problems with the ECG acquisition, while the implementation with high specificity (Sp = 97.8%, Se = 81.8%) is less susceptible to transient problems but rather validates noisy ECGs with acceptable quality during a small portion of the recording.

  20. ECG-Based Detection of Early Myocardial Ischemia in a Computational Model: Impact of Additional Electrodes, Optimal Placement, and a New Feature for ST Deviation

    PubMed Central

    Loewe, Axel; Schulze, Walther H. W.; Jiang, Yuan; Wilhelms, Mathias; Luik, Armin; Dössel, Olaf; Seemann, Gunnar

    2015-01-01

    In case of chest pain, immediate diagnosis of myocardial ischemia is required to respond with an appropriate treatment. The diagnostic capability of the electrocardiogram (ECG), however, is strongly limited for ischemic events that do not lead to ST elevation. This computational study investigates the potential of different electrode setups in detecting early ischemia at 10 minutes after onset: standard 3-channel and 12-lead ECG as well as body surface potential maps (BSPMs). Further, it was assessed if an additional ECG electrode with optimized position or the right-sided Wilson leads can improve sensitivity of the standard 12-lead ECG. To this end, a simulation study was performed for 765 different locations and sizes of ischemia in the left ventricle. Improvements by adding a single, subject specifically optimized electrode were similar to those of the BSPM: 2–11% increased detection rate depending on the desired specificity. Adding right-sided Wilson leads had negligible effect. Absence of ST deviation could not be related to specific locations of the ischemic region or its transmurality. As alternative to the ST time integral as a feature of ST deviation, the K point deviation was introduced: the baseline deviation at the minimum of the ST-segment envelope signal, which increased 12-lead detection rate by 7% for a reasonable threshold. PMID:26587538

  1. ECG-Based Detection of Early Myocardial Ischemia in a Computational Model: Impact of Additional Electrodes, Optimal Placement, and a New Feature for ST Deviation.

    PubMed

    Loewe, Axel; Schulze, Walther H W; Jiang, Yuan; Wilhelms, Mathias; Luik, Armin; Dössel, Olaf; Seemann, Gunnar

    2015-01-01

    In case of chest pain, immediate diagnosis of myocardial ischemia is required to respond with an appropriate treatment. The diagnostic capability of the electrocardiogram (ECG), however, is strongly limited for ischemic events that do not lead to ST elevation. This computational study investigates the potential of different electrode setups in detecting early ischemia at 10 minutes after onset: standard 3-channel and 12-lead ECG as well as body surface potential maps (BSPMs). Further, it was assessed if an additional ECG electrode with optimized position or the right-sided Wilson leads can improve sensitivity of the standard 12-lead ECG. To this end, a simulation study was performed for 765 different locations and sizes of ischemia in the left ventricle. Improvements by adding a single, subject specifically optimized electrode were similar to those of the BSPM: 2-11% increased detection rate depending on the desired specificity. Adding right-sided Wilson leads had negligible effect. Absence of ST deviation could not be related to specific locations of the ischemic region or its transmurality. As alternative to the ST time integral as a feature of ST deviation, the K point deviation was introduced: the baseline deviation at the minimum of the ST-segment envelope signal, which increased 12-lead detection rate by 7% for a reasonable threshold.

  2. Electrocardiogram of the failing heart.

    PubMed

    Hombach, Vinzenz

    2002-09-01

    In the failing heart general specific (e.g., Q-waves after acute myocardial infarction, persistent ST-elevations in post-myocardial infarction left ventricular aneurysm) and unspecific ECG changes (e.g., left bundle branch block, right bundle branch block, ST-T-alterations due to digitalis glycosides or antiarrhythmic drugs) may be seen in the conventional 12-lead ECG. In addition, atrial and ventricular tachy-arrhythmias may be detected and quantified by 24-hour-Holter ECG recordings, that may be relevant for a worse prognosis of patients with congestive heart failure. Heart rate variability as the most relevant derived ECG parameter of sympathetic tone fluctuations may be of important prognostic significance in congestive heart failure patients. An abnormal signal averaged P-wave duration may predict the incidence of atrial fibrillation, as may apply to QRS-prolongation and/or ventricular late potentials in the signal averaged ECG for the incidence of serious life-threatening ventricular tachy-arrhythmias or death from pump failure. Last but not least, cardiac repolarization abnormalities may be detected by QT dispersion-, QT-/QTc-fluctuation- or T-wave alternans studies, but the true prognostic significance of these parameters for predicting sudden cardiac death or death from pump failure in patients with congestive heart failure remains unclear. PMID:12114840

  3. Exploiting multi-lead electrocardiogram correlations using robust third-order tensor decomposition.

    PubMed

    Padhy, Sibasankar; Dandapat, Samarendra

    2015-10-01

    In this Letter, a robust third-order tensor decomposition of multi-lead electrocardiogram (MECG) comprising of 12-leads is proposed to reduce the dimension of the storage data. An order-3 tensor structure is employed to represent the MECG data by rearranging the MECG information in three dimensions. The three-dimensions of the formed tensor represent the number of leads, beats and samples of some fixed ECG duration. Dimension reduction of such an arrangement exploits correlations present among the successive beats (intra-beat and inter-beat) and across the leads (inter-lead). The higher-order singular value decomposition is used to decompose the tensor data. In addition, multiscale analysis has been added for effective care of ECG information. It grossly segments the ECG characteristic waves (P-wave, QRS-complex, ST-segment and T-wave etc.) into different sub-bands. In the meantime, it separates high-frequency noise components into lower-order sub-bands which helps in removing noise from the original data. For evaluation purposes, we have used the publicly available PTB diagnostic database. The proposed method outperforms the existing algorithms where compression ratio is under 10 for MECG data. Results show that the original MECG data volume can be reduced by more than 45 times with acceptable diagnostic distortion level. PMID:26609416

  4. III Lead ECG Pulse Measurement Sensor

    NASA Astrophysics Data System (ADS)

    Thangaraju, S. K.; Munisamy, K.

    2015-09-01

    Heart rate sensing is very important. Method of measuring heart pulse by using an electrocardiogram (ECG) technique is described. Electrocardiogram is a measurement of the potential difference (the electrical pulse) generated by a cardiac tissue, mainly the heart. This paper also reports the development of a three lead ECG hardware system that would be the basis of developing a more cost efficient, portable and easy to use ECG machine. Einthoven's Three Lead method [1] is used for ECG signal extraction. Using amplifiers such as the instrumentation amplifier AD620BN and the conventional operational amplifier Ua741 that would be used to amplify the ECG signal extracted develop this system. The signal would then be filtered from noise using Butterworth filter techniques to obtain optimum output. Also a right leg guard was implemented as a safety feature to this system. Simulation was carried out for development of the system using P-spice Program.

  5. Extraction of the magnetohydrodynamic blood flow potential from the surface electrocardiogram in magnetic resonance imaging.

    PubMed

    Nijm, Grace M; Swiryn, Steven; Larson, Andrew C; Sahakian, Alan V

    2008-07-01

    The magnetohydrodynamic effect generates voltages related to blood flow, which are superimposed on the electrocardiogram (ECG) used for gating during cardiac magnetic resonance imaging (MRI). A method is presented for extracting the magnetohydrodynamic signal from the ECG. The extracted magnetohydrodynamic blood flow potential may be physiologically meaningful due to its relationship to blood flow. Removal of the magnetohydrodynamic voltages from the ECG can potentially lead to improved gating and diagnostically useful ECGs.

  6. Applicability of initial optimal maternal and fetal electrocardiogram combination vectors to subsequent recordings

    NASA Astrophysics Data System (ADS)

    Yan, Hua-Wen; Huang, Xiao-Lin; Zhao, Ying; Si, Jun-Feng; Liu, Tie-Bing; Liu, Hong-Xing

    2014-11-01

    A series of experiments are conducted to confirm whether the vectors calculated for an early section of a continuous non-invasive fetal electrocardiogram (fECG) recording can be directly applied to subsequent sections in order to reduce the computation required for real-time monitoring. Our results suggest that it is generally feasible to apply the initial optimal maternal and fetal ECG combination vectors to extract the fECG and maternal ECG in subsequent recorded sections.

  7. Modern standards of ECG interpretation in young athletes: yield and effectiveness.

    PubMed

    Asif, Irfan M; Prutkin, Jordan M

    2015-01-01

    Although cardiovascular screening is recommended before participating in competitive sports, the role of the 12-lead electrocardiogram (ECG) has been debated. When added to the medical history and physical examination, an ECG used during the pre-participation screening (PPS) of young athletes can greatly enhance the ability to detect underlying cardiovascular pathology. Concerns over false positive rates, however, have posed an obstacle to large-scale implementation. The recent development of modern athlete-specific ECG interpretation criteria has dramatically reduced false positive rates to levels below other commonly used screening tests (e.g. breast cancer, prostate cancer) and subsequently improved cost effectiveness. There are also emerging data that certain sub-groups have a higher prevalence of ECG abnormalities, including males, athletes of Afro-Caribbean descent, basketball players, and endurance athletes. While false positive rates from a number of studies are reduced with the improved standards, there may be room for continued improvements. Future efforts should focus on refining criteria based on age, race, gender, ethnicity, and sport, while also clearly delineating the appropriate work-up strategies for those with abnormal findings, as this can lead to improved resource utilization. PMID:25595717

  8. Modern standards of ECG interpretation in young athletes: yield and effectiveness.

    PubMed

    Asif, Irfan M; Prutkin, Jordan M

    2015-01-01

    Although cardiovascular screening is recommended before participating in competitive sports, the role of the 12-lead electrocardiogram (ECG) has been debated. When added to the medical history and physical examination, an ECG used during the pre-participation screening (PPS) of young athletes can greatly enhance the ability to detect underlying cardiovascular pathology. Concerns over false positive rates, however, have posed an obstacle to large-scale implementation. The recent development of modern athlete-specific ECG interpretation criteria has dramatically reduced false positive rates to levels below other commonly used screening tests (e.g. breast cancer, prostate cancer) and subsequently improved cost effectiveness. There are also emerging data that certain sub-groups have a higher prevalence of ECG abnormalities, including males, athletes of Afro-Caribbean descent, basketball players, and endurance athletes. While false positive rates from a number of studies are reduced with the improved standards, there may be room for continued improvements. Future efforts should focus on refining criteria based on age, race, gender, ethnicity, and sport, while also clearly delineating the appropriate work-up strategies for those with abnormal findings, as this can lead to improved resource utilization.

  9. [ECG mapping in clinical practice].

    PubMed

    Boudík, F; Aschermann, M; Anger, Z

    2002-12-01

    First the authors present a review of important cornerstones in the history of the electrocardiogram (ECG) and ECG mapping. The first to describe the electric cardiac field based on twenty ECGs was A.D. Waller in 1889. The decisive cornerstone for practical use was the introduction of a string galvanometer in 1901 by W. Einthoven and his triaxial lead system. Another very important cornerstone in the development of ECG were the findings of F.N. Wilson. Merits as regards the development and application of ECG mapping are due to B. Taccardi. Workers of the Second Medical Clinic in Prague enhanced after 15 years of studies and comparison of ECG maps with coronarographic findings in subjects with ischaemic heart disease (IHD) and microvascular coronary dysfunction (syndrome X--SyX) substantially the specificity of this method in impaired myocardial vascularization. Better diagnosis was achieved by introduction of diagnostic tests which influence coronary vascularization such as e.g. hyperventilation, as well as other tests. After their application progression of chronic myocardial ischaemia occurs, e.g. by the mechanism of the "steal phenomenon" or restriction of the microcirculation after hyperventilation in patients with SyX. Furthermore the authors present examples of ECG maps after PTCA, after application of diagnostic tests in IHD and SyX and also regression of myocardial ischaemia after marked reduction of total cholesterol. PMID:12744039

  10. Chaotic synchronization system and electrocardiogram

    NASA Astrophysics Data System (ADS)

    Pei, Liuqing; Dai, Xinlai; Li, Baodong

    1997-01-01

    A mathematical model of chaotic synchronization of the heart-blood flow coupling dynamics is proposed, which is based on a seven dimension nonlinear dynamical system constructed by three subsystems of the sinoatrial node natural pacemaker, the cardiac relaxation oscillator and the dynamics of blood-fluid in heart chambers. The existence and robustness of the self-chaotic synchronization of the system are demonstrated by both methods of theoretical analysis and numerical simulation. The spectrum of Lyapunov exponent, the Lyapunov dimension and the Kolmogorov entropy are estimated when the system was undergoing the state of self-chaotic synchronization evolution. The time waveform of the dynamical variable, which represents the membrane potential of the cardiac integrative cell, shows a shape which is similar to that of the normal electrocardiogram (ECG) of human, thus implies that the model possesses physiological significance functionally.

  11. Electrocardiogram Signal and Linear Time-Frequency Transforms

    NASA Astrophysics Data System (ADS)

    Krishna, B. T.

    2014-12-01

    The diagnostic analysis of non-stationary multi component signals such as electrocardiogram (ECG) involves the use of time-frequency transforms. So, the application of time-frequency transforms to an ECG signal is an important problem of research. In this paper, initially, linear transforms like short time Fourier transform, continuous wavelet transforms, s-transform etc. are revisited. Then the application of these transforms to normal and abnormal ECG signals is illustrated. It has been observed that s-transform provides better time and frequency resolution compared to other linear transforms. The fractional Fourier transform provides rotation to the spectrogram representation.

  12. Cardiac Arrhythmias and Abnormal Electrocardiograms After Acute Stroke.

    PubMed

    Ruthirago, Doungporn; Julayanont, Parunyou; Tantrachoti, Pakpoom; Kim, Jongyeol; Nugent, Kenneth

    2016-01-01

    Cardiac arrhythmias and electrocardiogram (ECG) abnormalities occur frequently but are often underrecognized after strokes. Acute ischemic and hemorrhagic strokes in some particular area of brain can disrupt central autonomic control of the heart, precipitating cardiac arrhythmias, ECG abnormalities, myocardial injury and sometimes sudden death. Identification of high-risk patients after acute stroke is important to arrange appropriate cardiac monitoring and effective management of arrhythmias, and to prevent cardiac morbidity and mortality. More studies are needed to better clarify pathogenesis, localization of areas associated with arrhythmias and practical management of arrhythmias and abnormal ECGs after acute stroke.

  13. Electrocardiogram-assisted blood pressure estimation.

    PubMed

    Ahmad, Saif; Chen, Silu; Soueidan, Karen; Batkin, Izmail; Bolic, Miodrag; Dajani, Hilmi; Groza, Voicu

    2012-03-01

    Accurate automatic noninvasive assessment of blood pressure (BP) presents a challenge due to conditions like arrhythmias, obesity, and postural changes that tend to obfuscate arterial amplitude pulsations sensed by the cuff. Researchers tried to overcome this challenge by analyzing oscillometric pulses with the aid of a higher fidelity signal-the electrocardiogram (ECG). Moreover, pulse transit time (PTT) was employed to provide an additional method for BP estimation. However, these methods were not fully developed, suitably integrated, or tested. To address these issues, we present a novel method whereby ECG-assisted oscillometric and PTT (measured between ECG R-peaks and maximum slope of arterial pulse peaks) analyses are seamlessly integrated into the oscillometric BP measurement paradigm. The method bolsters oscillometric analysis (amplitude modulation) with more reliable ECG R-peaks provides a complementary measure with PTT analysis (temporal modulation) and fuses this information for robust BP estimation. We have integrated this technology into a prototype that comprises a BP cuff with an embedded conductive fabric ECG electrode, associated hardware, and algorithms. A pilot study has been undertaken on ten healthy subjects (150 recordings) to validate the performance of our prototype against United States Food and Drug Administration approved Omron oscillometric monitor (HEM-790IT). Our prototype achieves mean absolute difference of less than 5 mmHg and grade A as per the British Hypertension Society protocol for estimating BP, with the reference Omron monitor.

  14. Surface Electrocardiogram Predictors of Sudden Cardiac Arrest

    PubMed Central

    Abdelghani, Samy A.; Rosenthal, Todd M.; Morin, Daniel P.

    2016-01-01

    Background: Heart disease is a major cause of death in industrialized nations, with approximately 50% of these deaths attributable to sudden cardiac arrest. If patients at high risk for sudden cardiac arrest can be identified, their odds of surviving fatal arrhythmias can be significantly improved through prophylactic implantable cardioverter defibrillator placement. This review summarizes the current knowledge pertaining to surface electrocardiogram (ECG) predictors of sudden cardiac arrest. Methods: We conducted a literature review focused on methods of predicting sudden cardiac arrest through noninvasive electrocardiographic testing. Results: Several electrocardiographic-based methods of risk stratification of sudden cardiac arrest have been studied, including QT prolongation, QRS duration, fragmented QRS complexes, early repolarization, Holter monitoring, heart rate variability, heart rate turbulence, signal-averaged ECG, T wave alternans, and T-peak to T-end. These ECG findings have shown variable effectiveness as screening tools. Conclusion: At this time, no individual ECG finding has been found to be able to adequately stratify patients with regard to risk for sudden cardiac arrest. However, one or more of these candidate surface ECG parameters may become useful components of future multifactorial risk stratification calculators.

  15. Surface Electrocardiogram Predictors of Sudden Cardiac Arrest

    PubMed Central

    Abdelghani, Samy A.; Rosenthal, Todd M.; Morin, Daniel P.

    2016-01-01

    Background: Heart disease is a major cause of death in industrialized nations, with approximately 50% of these deaths attributable to sudden cardiac arrest. If patients at high risk for sudden cardiac arrest can be identified, their odds of surviving fatal arrhythmias can be significantly improved through prophylactic implantable cardioverter defibrillator placement. This review summarizes the current knowledge pertaining to surface electrocardiogram (ECG) predictors of sudden cardiac arrest. Methods: We conducted a literature review focused on methods of predicting sudden cardiac arrest through noninvasive electrocardiographic testing. Results: Several electrocardiographic-based methods of risk stratification of sudden cardiac arrest have been studied, including QT prolongation, QRS duration, fragmented QRS complexes, early repolarization, Holter monitoring, heart rate variability, heart rate turbulence, signal-averaged ECG, T wave alternans, and T-peak to T-end. These ECG findings have shown variable effectiveness as screening tools. Conclusion: At this time, no individual ECG finding has been found to be able to adequately stratify patients with regard to risk for sudden cardiac arrest. However, one or more of these candidate surface ECG parameters may become useful components of future multifactorial risk stratification calculators. PMID:27660578

  16. [Low-power Wireless Micro Ambulatory Electrocardiogram Node].

    PubMed

    Cai, Zhipeng; Luo, Kan; Li, Jianqing

    2016-02-01

    Ambulatory electrocardiogram (ECG) monitoring can effectively reduce the risk and death rate of patients with cardiovascular diseases (CVDs). The Body Sensor Network (BSN) based ECG monitoring is a new and efficien method to protect the CVDs patients. To meet the challenges of miniaturization, low power and high signal quality of the node, we proposed a novel 50 mmX 50 mmX 10 mm, 30 g wireless ECG node, which includes the single-chip an alog front-end AD8232, ultra-low power microprocessor MSP430F1611 and Bluetooth module HM-11. The ECG signal quality is guaranteed by the on-line digital filtering. The difference threshold algorithm results in accuracy of R-wave detection and heart rate. Experiments were carried out to test the node and the results showed that the pro posed node reached the design target, and it has great potential in application of wireless ECG monitoring. PMID:27382732

  17. Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System.

    PubMed

    Kwon, Sungjun; Lee, Dongseok; Kim, Jeehoon; Lee, Youngki; Kang, Seungwoo; Seo, Sangwon; Park, Kwangsuk

    2016-03-11

    In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG) monitoring system, Sinabro, which monitors a user's ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR) and heart rate variability (HRV), to support the pervasive healthcare apps for smartphones based on the user's high-level contexts, such as stress and affective state levels. In this study, we have extended the Sinabro system by: (1) upgrading the sensor device; (2) improving the feature extraction process; and (3) evaluating extensions of the system. We evaluated these extensions with a good set of algorithm parameters that were suggested based on empirical analyses. The results showed that the system could capture ECG reliably and extract highly accurate ECG-derived features with a reasonable rate of data drop during the user's daily smartphone use.

  18. Sinabro: A Smartphone-Integrated Opportunistic Electrocardiogram Monitoring System

    PubMed Central

    Kwon, Sungjun; Lee, Dongseok; Kim, Jeehoon; Lee, Youngki; Kang, Seungwoo; Seo, Sangwon; Park, Kwangsuk

    2016-01-01

    In our preliminary study, we proposed a smartphone-integrated, unobtrusive electrocardiogram (ECG) monitoring system, Sinabro, which monitors a user’s ECG opportunistically during daily smartphone use without explicit user intervention. The proposed system also monitors ECG-derived features, such as heart rate (HR) and heart rate variability (HRV), to support the pervasive healthcare apps for smartphones based on the user’s high-level contexts, such as stress and affective state levels. In this study, we have extended the Sinabro system by: (1) upgrading the sensor device; (2) improving the feature extraction process; and (3) evaluating extensions of the system. We evaluated these extensions with a good set of algorithm parameters that were suggested based on empirical analyses. The results showed that the system could capture ECG reliably and extract highly accurate ECG-derived features with a reasonable rate of data drop during the user’s daily smartphone use. PMID:26978364

  19. Competency in ECG Interpretation Among Medical Students

    PubMed Central

    Kopeć, Grzegorz; Magoń, Wojciech; Hołda, Mateusz; Podolec, Piotr

    2015-01-01

    Background Electrocardiogram (ECG) is commonly used in diagnosis of heart diseases, including many life-threatening disorders. We aimed to assess skills in ECG interpretation among Polish medical students and to analyze the determinants of these skills. Material/Methods Undergraduates from all Polish medical schools were asked to complete a web-based survey containing 18 ECG strips. Questions concerned primary ECG parameters (rate, rhythm, and axis), emergencies, and common ECG abnormalities. Analysis was restricted to students in their clinical years (4th–6th), and students in their preclinical years (1st–3rd) were used as controls. Results We enrolled 536 medical students (females: n=299; 55.8%), aged 19 to 31 (23±1.6) years from all Polish medical schools. Most (72%) were in their clinical years. The overall rate of good response was better in students in years 4th–5th than those in years 1st–3rd (66% vs. 56%; p<0.0001). Competency in ECG interpretation was higher in students who reported ECG self-learning (69% vs. 62%; p<0.0001) but no difference was found between students who attended or did not attend regular ECG classes (66% vs. 66%; p=0.99). On multivariable analysis (p<0.0001), being in clinical years (OR: 2.45 [1.35–4.46] and self-learning (OR: 2.44 [1.46–4.08]) determined competency in ECG interpretation. Conclusions Polish medical students in their clinical years have a good level of competency in interpreting the primary ECG parameters, but their ability to recognize ECG signs of emergencies and common heart abnormalities is low. ECG interpretation skills are determined by self-education but not by attendance at regular ECG classes. Our results indicate qualitative and quantitative deficiencies in teaching ECG interpretation at medical schools. PMID:26541993

  20. Reduction of motion artifacts in electrocardiogram monitoring using an optical sensor.

    PubMed

    Liu, Yan; Pecht, Michael G

    2011-01-01

    The effectiveness of electrocardiogram (ECG) monitors can be significantly impaired by motion artifacts, which can trigger false alarms, cause misdiagnoses, and lead to inappropriate treatment decisions. Skin stretch associated with patient motion is the most significant source of motion artifacts in current ECG monitoring. In this study, motion artifacts are adaptively filtered by using skin strain as the reference variable, measured noninvasively using an optical sensor incorporated into an ECG electrode. The results demonstrate that this new device and method can significantly reduce motion induced ECG artifacts in continuous ambulatory ECG monitoring.

  1. Human Identification with Electrocardiogram Signals: a Neural Network Approach

    NASA Astrophysics Data System (ADS)

    Wan, Yongbo; Yao, Jianchu

    2009-05-01

    This paper presents a neural network developed to identify human subjects using electrocardiogram (ECG) signals collected from an "in-house" wearable electrocardiogram (ECG) sensor. In this project, noises were first removed from the raw signals with wavelet filters. ECG cycles were then extracted from the filtered signals and decomposed into wavelet coefficient structures. These coefficient structures were used as input vectors to a 3-layer feedforward neural network that generates the identification results. In the current study, 61 datasets collected from 23 subjects were utilized to train the neural network, which thereafter was tested with 15 new datasets from 15 different subjects. All the 15 subjects in the experiment were successfully identified. The testing results demonstrate that the neural network is effective.

  2. [Wireless ECG measurement system with capacitive coupling].

    PubMed

    Aleksandrowicz, Adrian; Walter, Marian; Leonhardt, Steffen

    2007-04-01

    This paper describes a measurement system that captures an electrocardiogram (ECG) using capacitively coupled electrodes. The measurement system was integrated into an off-the-shelf office chair (so-called "Aachen SmartChair"). Whereas for classical ECG measurement adhesive is used to attach conductively coupled electrodes to bare skin, the system presented allows ECG measurement through clothing without direct skin contact. Furthermore, a ZigBee communication module was integrated to allow wireless transmission of ECG data to a PC or an ICU patient monitor. For system validation, classical ECG using conductive electrodes was obtained simultaneously. First measurement results, including variations of cloth thickness and material, are presented and some of the system-specific problems of this approach are discussed.

  3. Bluetooth telemetry system for a wearable electrocardiogram

    NASA Astrophysics Data System (ADS)

    Green, Ryan B.

    The rise of wireless networks has led to a new market in medicine: remote patient monitoring. Practitioners now desire to monitor the health conditions of their patients after hospital release. With the large number of cardiac related deaths and this new demand in medicine being the motivation, this study developed a BluetoothRTM telemetry system for a wearable Electrocardiogram. This study also developed a compression t-shirt to hold the ECG and telemetry system. This device communicates the ECG signal of a patient to an Android device within the ISM frequency bands (2.4-2.48 GHz) where the data is displayed and stored in real time. This study is a stepping stone toward more portable heart monitoring that can communicate with the doctor in real time from remote locations.

  4. A novel electrocardiogram parameterization algorithm and its application in myocardial infarction detection.

    PubMed

    Liu, Bin; Liu, Jikui; Wang, Guoqing; Huang, Kun; Li, Fan; Zheng, Yang; Luo, Youxi; Zhou, Fengfeng

    2015-06-01

    The electrocardiogram (ECG) is a biophysical electric signal generated by the heart muscle, and is one of the major measurements of how well a heart functions. Automatic ECG analysis algorithms usually extract the geometric or frequency-domain features of the ECG signals and have already significantly facilitated automatic ECG-based cardiac disease diagnosis. We propose a novel ECG feature by fitting a given ECG signal with a 20th order polynomial function, defined as PolyECG-S. The PolyECG-S feature is almost identical to the fitted ECG curve, measured by the Akaike information criterion (AIC), and achieved a 94.4% accuracy in detecting the Myocardial Infarction (MI) on the test dataset. Currently ST segment elongation is one of the major ways to detect MI (ST-elevation myocardial infarction, STEMI). However, many ECG signals have weak or even undetectable ST segments. Since PolyECG-S does not rely on the information of ST waves, it can be used as a complementary MI detection algorithm with the STEMI strategy. Overall, our results suggest that the PolyECG-S feature may satisfactorily reconstruct the fitted ECG curve, and is complementary to the existing ECG features for automatic cardiac function analysis.

  5. Transtelephonic transmission of electrocardiograms in Slovenia.

    PubMed

    Gorjup, V; Jazbec, A; Gersak, B

    2000-01-01

    The transtelephonic transmission of electrocardiograms (ECGs) was introduced in Slovenia in 1996 and has been used regularly since September 1997 by health institutions and patients with cardiovascular diseases. Portable 12-channel ECG equipment weighing less than 200 g is generally used. The diagnostic centre is located in the intensive-care unit at the University Medical Centre Ljubljana. In the first 12 months of regular operation we received 463 calls, 213 of which were diagnostic. The most common reasons for calling were: ischaemic chest pain, atypical chest pain, palpitations and dyspnoea. The most common diagnoses made on the basis of history and the ECG were: acute myocardial infarction, angina pectoris, paroxysmal tachycardias and atypical chest pain. In 40% of cases the cardiologist's advice sufficed; 38% of patients were referred to the emergency room, 29% immediately and 9% only if a suggested therapy did not prove successful; and in 21% of cases new medication or a change of dosage of current medication was suggested. Transtelephonic ECG transmission enables direct communication between general practitioner or patient and cardiologist. With its use, time from onset of symptoms to initiation of treatment is shortened, which reduces disability and mortality due to cardiovascular diseases and improves cost-benefit.

  6. Electrocardiogram signal denoising based on a new improved wavelet thresholding

    NASA Astrophysics Data System (ADS)

    Han, Guoqiang; Xu, Zhijun

    2016-08-01

    Good quality electrocardiogram (ECG) is utilized by physicians for the interpretation and identification of physiological and pathological phenomena. In general, ECG signals may mix various noises such as baseline wander, power line interference, and electromagnetic interference in gathering and recording process. As ECG signals are non-stationary physiological signals, wavelet transform is investigated to be an effective tool to discard noises from corrupted signals. A new compromising threshold function called sigmoid function-based thresholding scheme is adopted in processing ECG signals. Compared with other methods such as hard/soft thresholding or other existing thresholding functions, the new algorithm has many advantages in the noise reduction of ECG signals. It perfectly overcomes the discontinuity at ±T of hard thresholding and reduces the fixed deviation of soft thresholding. The improved wavelet thresholding denoising can be proved to be more efficient than existing algorithms in ECG signal denoising. The signal to noise ratio, mean square error, and percent root mean square difference are calculated to verify the denoising performance as quantitative tools. The experimental results reveal that the waves including P, Q, R, and S waves of ECG signals after denoising coincide with the original ECG signals by employing the new proposed method.

  7. Electrocardiogram signal denoising based on a new improved wavelet thresholding.

    PubMed

    Han, Guoqiang; Xu, Zhijun

    2016-08-01

    Good quality electrocardiogram (ECG) is utilized by physicians for the interpretation and identification of physiological and pathological phenomena. In general, ECG signals may mix various noises such as baseline wander, power line interference, and electromagnetic interference in gathering and recording process. As ECG signals are non-stationary physiological signals, wavelet transform is investigated to be an effective tool to discard noises from corrupted signals. A new compromising threshold function called sigmoid function-based thresholding scheme is adopted in processing ECG signals. Compared with other methods such as hard/soft thresholding or other existing thresholding functions, the new algorithm has many advantages in the noise reduction of ECG signals. It perfectly overcomes the discontinuity at ±T of hard thresholding and reduces the fixed deviation of soft thresholding. The improved wavelet thresholding denoising can be proved to be more efficient than existing algorithms in ECG signal denoising. The signal to noise ratio, mean square error, and percent root mean square difference are calculated to verify the denoising performance as quantitative tools. The experimental results reveal that the waves including P, Q, R, and S waves of ECG signals after denoising coincide with the original ECG signals by employing the new proposed method. PMID:27587134

  8. Interictal 12-lead electrocardiography in patients with epilepsy.

    PubMed

    Krishnan, Vaishnav; Krishnamurthy, Kaarkuzhali B

    2013-10-01

    Interictal electrocardiographic predictors of sudden unexpected death in epilepsy (SUDEP) are unknown. This study was designed to identify the unique features of the interictal 12-lead electrocardiogram (EKG) in patients with epileptic seizures. We conducted a retrospective chart review of adult patients below the age of 65 admitted to our epilepsy monitoring unit. Using EEG telemetry data, we classified patients as having nonepileptic seizures (NESs), probable epilepsy (PE), or definite epilepsy (DE) and analyzed 12-lead EKGs obtained on admission. Patients with NESs were assigned as the control group. We included patients taking antipsychotic and/or antidepressant medications but excluded patients with medical conditions or taking other medications that would otherwise confound EKG measurements. Out of the 1007 charts reviewed, 195 patients were included in our analysis, and extensive subgroup analyses were performed. We found that patients with definite localization-related epilepsy displayed a significantly longer average PR interval (162.1 ms) than patients with NESs (148.8 ms). This effect was pronounced in female patients and did not vary with the number of antiepileptic drugs (AEDs) prescribed. In contrast to previous studies, mean QTc intervals were not significantly different between DE (428 ms) and NESs (422.6 ms). However, within females, this difference reached statistical significance (DE: 434.6 ms, NESs: 424.6 ms). Antiepileptic drug polytherapy was associated with a significantly lower QTc interval (416 ms in patients on 4-6 drugs and 436.4 ms in patients on 0-1 drugs). Levetiracetam was the most commonly used AED and was associated with the longest average PR (163 ms) and QTc (432 ms) intervals. The mean QRS axis displayed a significant leftward shift in patients with localization-related epilepsy (35.6° versus 54.3° in patients with NESs) and also in female patients with DE (42.1° versus 55.4° in female patients with NESs). No differences were

  9. Electrocardiogram on a chip: overview and first experiences of an electrocardiogram manufacturer of medium size.

    PubMed

    Abächerli, Roger; Braun, Francis; Zhou, Lingchuan; Kraemer, Michel; Felblinger, Jacques; Schmid, Hans-Jakob

    2006-10-01

    The integration of an electrocardiogram (ECG) device into a chip is already well known in the field of implanted devices, such as pacemakers. For noninvasive electrocardiology, this approach has not been used on a broad scale commercially. The extension of electrocardiology to telemetry, home care, and special applications as in magnetic resonance imaging has spawned a new interest in highly miniaturized ECG devices. In our company, we are aiming for using highly integrated devices exactly in these fields. On one hand, the home monitoring market ("eHealth," "pHealth") requires small and lightweight devices ("ECG in an electrode"); on the other hand, the use of an ECG device within a hostile environment as in an magnetic resonance imaging machine with strong electromagnetic fields requires small dimensions of the device. Of these 2 fields, the one of home monitoring is the most promising. There is a large population in need of such monitoring (eg, patients with congestive heart failure), and the cost issue in medical care drives the market in this direction. Projects in both fields will be presented as well as the first experiences as a middle-sized manufacturer in trying to produce an integrated ECG "device."

  10. Quality assessment of digital annotated ECG data from clinical trials by the FDA ECG Warehouse.

    PubMed

    Sarapa, Nenad

    2007-09-01

    The FDA mandates that digital electrocardiograms (ECGs) from 'thorough' QTc trials be submitted into the ECG Warehouse in Health Level 7 extended markup language format with annotated onset and offset points of waveforms. The FDA did not disclose the exact Warehouse metrics and minimal acceptable quality standards. The author describes the Warehouse scoring algorithms and metrics used by FDA, points out ways to improve FDA review and suggests Warehouse benefits for pharmaceutical sponsors. The Warehouse ranks individual ECGs according to their score for each quality metric and produces histogram distributions with Warehouse-specific thresholds that identify ECGs of questionable quality. Automatic Warehouse algorithms assess the quality of QT annotation and duration of manual QT measurement by the central ECG laboratory.

  11. Detecting motion artifact ECG noise during sleeping by means of a tri-axis accelerometer.

    PubMed

    Kishimoto, Yoshifumi; Kutsuna, Yasunari; Oguri, Koji

    2007-01-01

    The electrocardiogram (ECG) monitoring has become a helpful tool for detecting a number of heart diseases. High quality ECG is utilized by the physicians for interpretation and identification of physiological and pathological phenomena. ECG recordings, however, are often corrupted by motion artifacts even when patient is sleeping due to his or her positional change. In this paper, we proposed a new method of detecting motion artifact ECG noise during sleeping based on acceleration data. The experimental recordings of ECG and acceleration signal were collected from 8 subjects. The result in this study demonstrated that the proposed approach is effective for detecting corruption of ECG signal.

  12. Wavelets for full reconfigurable ECG acquisition system

    NASA Astrophysics Data System (ADS)

    Morales, D. P.; García, A.; Castillo, E.; Meyer-Baese, U.; Palma, A. J.

    2011-06-01

    This paper presents the use of wavelet cores for a full reconfigurable electrocardiogram signal (ECG) acquisition system. The system is compound by two reconfigurable devices, a FPGA and a FPAA. The FPAA is in charge of the ECG signal acquisition, since this device is a versatile and reconfigurable analog front-end for biosignals. The FPGA is in charge of FPAA configuration, digital signal processing and information extraction such as heart beat rate and others. Wavelet analysis has become a powerful tool for ECG signal processing since it perfectly fits ECG signal shape. The use of these cores has been integrated in the LabVIEW FPGA module development tool that makes possible to employ VHDL cores within the usual LabVIEW graphical programming environment, thus freeing the designer from tedious and time consuming design of communication interfaces. This enables rapid test and graphical representation of results.

  13. ECG-based gating in ultra high field cardiovascular magnetic resonance using an independent component analysis approach

    PubMed Central

    2013-01-01

    Background In Cardiovascular Magnetic Resonance (CMR), the synchronization of image acquisition with heart motion is performed in clinical practice by processing the electrocardiogram (ECG). The ECG-based synchronization is well established for MR scanners with magnetic fields up to 3 T. However, this technique is prone to errors in ultra high field environments, e.g. in 7 T MR scanners as used in research applications. The high magnetic fields cause severe magnetohydrodynamic (MHD) effects which disturb the ECG signal. Image synchronization is thus less reliable and yields artefacts in CMR images. Methods A strategy based on Independent Component Analysis (ICA) was pursued in this work to enhance the ECG contribution and attenuate the MHD effect. ICA was applied to 12-lead ECG signals recorded inside a 7 T MR scanner. An automatic source identification procedure was proposed to identify an independent component (IC) dominated by the ECG signal. The identified IC was then used for detecting the R-peaks. The presented ICA-based method was compared to other R-peak detection methods using 1) the raw ECG signal, 2) the raw vectorcardiogram (VCG), 3) the state-of-the-art gating technique based on the VCG, 4) an updated version of the VCG-based approach and 5) the ICA of the VCG. Results ECG signals from eight volunteers were recorded inside the MR scanner. Recordings with an overall length of 87 min accounting for 5457 QRS complexes were available for the analysis. The records were divided into a training and a test dataset. In terms of R-peak detection within the test dataset, the proposed ICA-based algorithm achieved a detection performance with an average sensitivity (Se) of 99.2%, a positive predictive value (+P) of 99.1%, with an average trigger delay and jitter of 5.8 ms and 5.0 ms, respectively. Long term stability of the demixing matrix was shown based on two measurements of the same subject, each being separated by one year, whereas an averaged detection

  14. Reduction of skin stretch induced motion artifacts in electrocardiogram monitoring using adaptive filtering.

    PubMed

    Liu, Yan; Pecht, Michael G

    2006-01-01

    The effectiveness of electrocardiogram (ECG) monitors can be significantly impaired by motion artifacts which can cause misdiagnoses, lead to inappropriate treatment decisions, and trigger false alarms. Skin stretch associated with patient motion is a significant source of motion artifacts in current ECG monitoring. In this study, motion artifacts are adaptively filtered by using skin strain as the reference variable. Skin strain is measured non-invasively using a light emitting diode (LED) and an optical sensor incorporated in an ECG electrode. The results demonstrate that this device and method can significantly reduce skin strain induced ECG artifacts.

  15. Normalizing Electrocardiograms of Both Healthy Persons and Cardiovascular Disease Patients for Biometric Authentication

    PubMed Central

    Zhao, Miaomiao; Li, Fan; Wang, Guoqing; Zhou, Fengfeng

    2013-01-01

    Although electrocardiogram (ECG) fluctuates over time and physical activity, some of its intrinsic measurements serve well as biometric features. Considering its constant availability and difficulty in being faked, the ECG signal is becoming a promising factor for biometric authentication. The majority of the currently available algorithms only work well on healthy participants. A novel normalization and interpolation algorithm is proposed to convert an ECG signal into multiple template cycles, which are comparable between any two ECGs, no matter the sampling rates or health status. The overall accuracies reach 100% and 90.11% for healthy participants and cardiovascular disease (CVD) patients, respectively. PMID:23977063

  16. Normalizing electrocardiograms of both healthy persons and cardiovascular disease patients for biometric authentication.

    PubMed

    Yang, Meixue; Liu, Bin; Zhao, Miaomiao; Li, Fan; Wang, Guoqing; Zhou, Fengfeng

    2013-01-01

    Although electrocardiogram (ECG) fluctuates over time and physical activity, some of its intrinsic measurements serve well as biometric features. Considering its constant availability and difficulty in being faked, the ECG signal is becoming a promising factor for biometric authentication. The majority of the currently available algorithms only work well on healthy participants. A novel normalization and interpolation algorithm is proposed to convert an ECG signal into multiple template cycles, which are comparable between any two ECGs, no matter the sampling rates or health status. The overall accuracies reach 100% and 90.11% for healthy participants and cardiovascular disease (CVD) patients, respectively. PMID:23977063

  17. Flexible Capacitive Electrodes for Minimizing Motion Artifacts in Ambulatory Electrocardiograms

    PubMed Central

    Lee, Jeong Su; Heo, Jeong; Lee, Won Kyu; Lim, Yong Gyu; Kim, Youn Ho; Park, Kwang Suk

    2014-01-01

    This study proposes the use of flexible capacitive electrodes for reducing motion artifacts in a wearable electrocardiogram (ECG) device. The capacitive electrodes have conductive foam on their surface, a shield, an optimal input bias resistor, and guarding feedback. The electrodes are integrated in a chest belt, and the acquired signals are transmitted wirelessly for ambulatory heart rate monitoring. We experimentally validated the electrode performance with subjects standing and walking on a treadmill at speeds of up to 7 km/h. The results confirmed the highly accurate heart rate detection capacity of the developed system and its feasibility for daily-life ECG monitoring. PMID:25120162

  18. Detection of Electrocardiogram by Electrodes with Fabrics Using Capacitive Coupling

    NASA Astrophysics Data System (ADS)

    Ueno, Akinori; Furusawa, Yoichi; Hoshino, Hiroshi; Ishiyama, Yoji

    This article reports on a novel technique for detecting electrocardiogram (ECG) at a condition where thin cloth is interpolated between sensing electrodes and the skin to which the electrodes are attached. The technique is based upon capacitive coupling composed of the electrode, the cloth and the skin, so that the electrode can lead alternating electrocardiographic current through capacitance of the coupling. The technique is also founded on impedance transforming circuit that has extremely high input impedance around 1000GΩ and low output impedance, so as to match high output impedance of the electrode to low input impedance required by subsequent circuitry. A pilot ECG measuring device was manufactured using the technique and experiments showed (1) ECG recordings using the device with silk of 240μm thickness or with cotton of 564μm thickness were quite similar to ECGs recorded from the skin using conventional system, (2) stable ECGs were observed with the silk below 600μm thickness or with the cotton below 1128μm thickness, (3) effects of long-term measurement and perspiration on ECG waveform were negligible. These results prove feasibility of the proposed technique for detecting ECG by electrodes with fabrics.

  19. Development and clinical study of mobile 12-lead electrocardiography based on cloud computing for cardiac emergency.

    PubMed

    Fujita, Hideo; Uchimura, Yuji; Waki, Kayo; Omae, Koji; Takeuchi, Ichiro; Ohe, Kazuhiko

    2013-01-01

    To improve emergency services for accurate diagnosis of cardiac emergency, we developed a low-cost new mobile electrocardiography system "Cloud Cardiology®" based upon cloud computing for prehospital diagnosis. This comprises a compact 12-lead ECG unit equipped with Bluetooth and Android Smartphone with an application for transmission. Cloud server enables us to share ECG simultaneously inside and outside the hospital. We evaluated the clinical effectiveness by conducting a clinical trial with historical comparison to evaluate this system in a rapid response car in the real emergency service settings. We found that this system has an ability to shorten the onset to balloon time of patients with acute myocardial infarction, resulting in better clinical outcome. Here we propose that cloud-computing based simultaneous data sharing could be powerful solution for emergency service for cardiology, along with its significant clinical outcome. PMID:23920851

  20. Development and clinical study of mobile 12-lead electrocardiography based on cloud computing for cardiac emergency.

    PubMed

    Fujita, Hideo; Uchimura, Yuji; Waki, Kayo; Omae, Koji; Takeuchi, Ichiro; Ohe, Kazuhiko

    2013-01-01

    To improve emergency services for accurate diagnosis of cardiac emergency, we developed a low-cost new mobile electrocardiography system "Cloud Cardiology®" based upon cloud computing for prehospital diagnosis. This comprises a compact 12-lead ECG unit equipped with Bluetooth and Android Smartphone with an application for transmission. Cloud server enables us to share ECG simultaneously inside and outside the hospital. We evaluated the clinical effectiveness by conducting a clinical trial with historical comparison to evaluate this system in a rapid response car in the real emergency service settings. We found that this system has an ability to shorten the onset to balloon time of patients with acute myocardial infarction, resulting in better clinical outcome. Here we propose that cloud-computing based simultaneous data sharing could be powerful solution for emergency service for cardiology, along with its significant clinical outcome.

  1. Microprocessor-based simulator of surface ECG signals

    NASA Astrophysics Data System (ADS)

    Martínez, A. E.; Rossi, E.; Siri, L. Nicola

    2007-11-01

    In this work, a simulator of surface electrocardiogram recorded signals (ECG) is presented. The device, based on a microcontroller and commanded by a personal computer, produces an analog signal resembling actual ECGs, not only in time course and voltage levels, but also in source impedance. The simulator is a useful tool for electrocardiograph calibration and monitoring, to incorporate as well in educational tasks and in clinical environments for early detection of faulty behaviour.

  2. Feasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies. The SEARCH-AF study.

    PubMed

    Lowres, Nicole; Neubeck, Lis; Salkeld, Glenn; Krass, Ines; McLachlan, Andrew J; Redfern, Julie; Bennett, Alexandra A; Briffa, Tom; Bauman, Adrian; Martinez, Carlos; Wallenhorst, Christopher; Lau, Jerrett K; Brieger, David B; Sy, Raymond W; Freedman, S Ben

    2014-06-01

    Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy.Pharmacists performedpulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8-2.5%); mean age 79 ± 6 years; all had CHA2DS2-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92-100%) sensitivity for AF detection and 91.4% (CI, 89-93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence.Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered.

  3. Feasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies. The SEARCH-AF study.

    PubMed

    Lowres, Nicole; Neubeck, Lis; Salkeld, Glenn; Krass, Ines; McLachlan, Andrew J; Redfern, Julie; Bennett, Alexandra A; Briffa, Tom; Bauman, Adrian; Martinez, Carlos; Wallenhorst, Christopher; Lau, Jerrett K; Brieger, David B; Sy, Raymond W; Freedman, S Ben

    2014-06-01

    Atrial fibrillation (AF) causes a third of all strokes, but often goes undetected before stroke. Identification of unknown AF in the community and subsequent anti-thrombotic treatment could reduce stroke burden. We investigated community screening for unknown AF using an iPhone electrocardiogram (iECG) in pharmacies, and determined the cost-effectiveness of this strategy.Pharmacists performedpulse palpation and iECG recordings, with cardiologist iECG over-reading. General practitioner review/12-lead ECG was facilitated for suspected new AF. An automated AF algorithm was retrospectively applied to collected iECGs. Cost-effectiveness analysis incorporated costs of iECG screening, and treatment/outcome data from a United Kingdom cohort of 5,555 patients with incidentally detected asymptomatic AF. A total of 1,000 pharmacy customers aged ≥65 years (mean 76 ± 7 years; 44% male) were screened. Newly identified AF was found in 1.5% (95% CI, 0.8-2.5%); mean age 79 ± 6 years; all had CHA2DS2-VASc score ≥2. AF prevalence was 6.7% (67/1,000). The automated iECG algorithm showed 98.5% (CI, 92-100%) sensitivity for AF detection and 91.4% (CI, 89-93%) specificity. The incremental cost-effectiveness ratio of extending iECG screening into the community, based on 55% warfarin prescription adherence, would be $AUD5,988 (€3,142; $USD4,066) per Quality Adjusted Life Year gained and $AUD30,481 (€15,993; $USD20,695) for preventing one stroke. Sensitivity analysis indicated cost-effectiveness improved with increased treatment adherence.Screening with iECG in pharmacies with an automated algorithm is both feasible and cost-effective. The high and largely preventable stroke/thromboembolism risk of those with newly identified AF highlights the likely benefits of community AF screening. Guideline recommendation of community iECG AF screening should be considered. PMID:24687081

  4. [Elimination of electrocardiogram artifacts from electroencephalogram records by using the simultaneously recorded electrocardiograph data].

    PubMed

    Okamoto, Yasuyuki; Yuki, Michi; Imai, Ryuko; Shinki, Yoshiyuki; Yamanaka, Masami; Masutani, Takayuki

    2002-12-01

    We developed a simple method to eliminate electrocardiogram (ECG) artifacts from electroencephalogram (EEG) records by using simultaneously recorded ECG data. The raw EEG data, the real EEG data and the ECG data were regarded as multi-dimensional vectors Ea, Er and C, respectively. Also, the ECG data, with reduced amplitude whose coefficient was denoted as 'k', were assumed to be overlapped on the real EEG. These assumptions introduced the equations [Ea = Er + k.C], [Er.C = 0] and finally [k = Ea. C/C.C]. This calculation method was implemented by a Macintosh computer using data exported from digital EEG recordings (sampled at 200 Hz with 16-bit resolution). In several subjects, sampling intervals of 5 or 10 seconds for calculation succeeded in eliminating ECG artifacts. However, regardless of the sampling interval, this elimination condition was not always efficient in several other subjects, including a brain-dead patient. It was suggested that the ECG data used were insufficient for the calculation, because only one hand-to-hand reference was used for simultaneous recording, as usual. This one ECG reference was able to express only one ECG projection. Then two other hand-to-foot references of ECG were added to the recordings, and the elimination procedure was performed using all of the simultaneously recorded ECG data at the three references. Consequently, elimination was much improved in most subjects, including the brain-dead patient. Our method may be useful for eliminating ECG artifacts without changing reference electrodes.

  5. Ischemia detection by electrocardiogram in wavelet domain using entropy measure

    PubMed Central

    Rabbani, Hossein; Mahjoob, Mohammad Parsa; Farahabadi, Eiman; Farahabadi, Amin; Dehnavi, Alireza Mehri

    2011-01-01

    BACKGROUND: Ischemic heart disease is one of the common fatal diseases in advanced countries. Because signal perturbation in healthy people is less than signal perturbation in patients, entropy measure can be used as an appropriate feature for ischemia detection. METHODS: Four entropy-based methods comprising of using electrocardiogram (ECG) signal directly, wavelet sub-bands of ECG signals, extracted ST segments and reconstructed signal from time-frequency feature of ST segments in wavelet domain were investigated to distinguish between ECG signal of healthy individuals and patients. We used exercise treadmill test as a gold standard, with a sample of 40 patients who had ischemic signs based on initial diagnosis of medical practitioner. RESULTS: The suggested technique in wavelet domain resulted in the highest discrepancy between healthy individuals and patients in comparison to other methods. Specificity and sensitivity of this method were 95% and 94% respectively. CONCLUSIONS: The method based on wavelet sub-bands outperformed the others. PMID:22973350

  6. High Resolution ECG for Evaluation of Heart Function During Exposure to Subacute Hypobaric Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, Petra; Finderle, Zarko; Schlegel, Todd T.; Princi, Tanja; Starc, Vito

    2010-01-01

    High altitude climbing presents a wide spectrum of health risks, including exposure to hypobaric hypoxia. Risks are also typically exacerbated by the difficulty in appropriately monitoring for early signs of organ dysfunction in remote areas. We investigated whether high resolution advanced ECG analysis might be helpful as a non-invasive and easy-to-use tool (e.g., instead of Doppler echocardiography) for evaluating early signs of heart overload in hypobaric hypoxia. Nine non-acclimatized healthy trained alpine rescuers (age 43.7 plus or minus 7.3 years) climbed in four days to the altitude of 4,200 m on Mount Ararat. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position on different days but at the same time of day at four different altitudes: 400 m (reference altitude), 1,700 m, 3,200 m and 4,200 m. Changes in conventional and advanced resting ECG parameters, including in beat-to-beat QT and RR variability, waveform complexity, signal-averaged, high-frequency and spatial/spatiotemporal ECG was estimated by calculation of the regression coefficients in independent linear regression models. A p-value of less than 0.05 was adopted as statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with trends k = -96 ms/1000 m with p = 0.000 and k = -9 ms/1000 m with p = 0.001, respectively. Significant changes were found in P-wave amplitude, which nearly doubled from the lowest to the highest altitude (k = 41.6 microvolt/1000 m with p = 0.000), and nearly significant changes in P-wave duration (k = 2.9 ms/1000 m with p = 0.059). Changes were less significant or non-significant in other studied parameters including those of waveform complexity, signal-averaged, high-frequency and spatial/spatiotemporal ECG. High resolution ECG analysis, particularly of the P wave, shows promise as a tool for monitoring early changes in heart function

  7. A novel biometric authentication approach using ECG and EMG signals.

    PubMed

    Belgacem, Noureddine; Fournier, Régis; Nait-Ali, Amine; Bereksi-Reguig, Fethi

    2015-05-01

    Security biometrics is a secure alternative to traditional methods of identity verification of individuals, such as authentication systems based on user name and password. Recently, it has been found that the electrocardiogram (ECG) signal formed by five successive waves (P, Q, R, S and T) is unique to each individual. In fact, better than any other biometrics' measures, it delivers proof of subject's being alive as extra information which other biometrics cannot deliver. The main purpose of this work is to present a low-cost method for online acquisition and processing of ECG signals for person authentication and to study the possibility of providing additional information and retrieve personal data from an electrocardiogram signal to yield a reliable decision. This study explores the effectiveness of a novel biometric system resulting from the fusion of information and knowledge provided by ECG and EMG (Electromyogram) physiological recordings. It is shown that biometrics based on these ECG/EMG signals offers a novel way to robustly authenticate subjects. Five ECG databases (MIT-BIH, ST-T, NSR, PTB and ECG-ID) and several ECG signals collected in-house from volunteers were exploited. A palm-based ECG biometric system was developed where the signals are collected from the palm of the subject through a minimally intrusive one-lead ECG set-up. A total of 3750 ECG beats were used in this work. Feature extraction was performed on ECG signals using Fourier descriptors (spectral coefficients). Optimum-Path Forest classifier was used to calculate the degree of similarity between individuals. The obtained results from the proposed approach look promising for individuals' authentication. PMID:25836061

  8. A novel biometric authentication approach using ECG and EMG signals.

    PubMed

    Belgacem, Noureddine; Fournier, Régis; Nait-Ali, Amine; Bereksi-Reguig, Fethi

    2015-05-01

    Security biometrics is a secure alternative to traditional methods of identity verification of individuals, such as authentication systems based on user name and password. Recently, it has been found that the electrocardiogram (ECG) signal formed by five successive waves (P, Q, R, S and T) is unique to each individual. In fact, better than any other biometrics' measures, it delivers proof of subject's being alive as extra information which other biometrics cannot deliver. The main purpose of this work is to present a low-cost method for online acquisition and processing of ECG signals for person authentication and to study the possibility of providing additional information and retrieve personal data from an electrocardiogram signal to yield a reliable decision. This study explores the effectiveness of a novel biometric system resulting from the fusion of information and knowledge provided by ECG and EMG (Electromyogram) physiological recordings. It is shown that biometrics based on these ECG/EMG signals offers a novel way to robustly authenticate subjects. Five ECG databases (MIT-BIH, ST-T, NSR, PTB and ECG-ID) and several ECG signals collected in-house from volunteers were exploited. A palm-based ECG biometric system was developed where the signals are collected from the palm of the subject through a minimally intrusive one-lead ECG set-up. A total of 3750 ECG beats were used in this work. Feature extraction was performed on ECG signals using Fourier descriptors (spectral coefficients). Optimum-Path Forest classifier was used to calculate the degree of similarity between individuals. The obtained results from the proposed approach look promising for individuals' authentication.

  9. ECG Sensor Card with Evolving RBP Algorithms for Human Verification.

    PubMed

    Tseng, Kuo-Kun; Huang, Huang-Nan; Zeng, Fufu; Tu, Shu-Yi

    2015-08-21

    It is known that cardiac and respiratory rhythms in electrocardiograms (ECGs) are highly nonlinear and non-stationary. As a result, most traditional time-domain algorithms are inadequate for characterizing the complex dynamics of the ECG. This paper proposes a new ECG sensor card and a statistical-based ECG algorithm, with the aid of a reduced binary pattern (RBP), with the aim of achieving faster ECG human identity recognition with high accuracy. The proposed algorithm has one advantage that previous ECG algorithms lack-the waveform complex information and de-noising preprocessing can be bypassed; therefore, it is more suitable for non-stationary ECG signals. Experimental results tested on two public ECG databases (MIT-BIH) from MIT University confirm that the proposed scheme is feasible with excellent accuracy, low complexity, and speedy processing. To be more specific, the advanced RBP algorithm achieves high accuracy in human identity recognition and is executed at least nine times faster than previous algorithms. Moreover, based on the test results from a long-term ECG database, the evolving RBP algorithm also demonstrates superior capability in handling long-term and non-stationary ECG signals.

  10. ECG Sensor Card with Evolving RBP Algorithms for Human Verification.

    PubMed

    Tseng, Kuo-Kun; Huang, Huang-Nan; Zeng, Fufu; Tu, Shu-Yi

    2015-01-01

    It is known that cardiac and respiratory rhythms in electrocardiograms (ECGs) are highly nonlinear and non-stationary. As a result, most traditional time-domain algorithms are inadequate for characterizing the complex dynamics of the ECG. This paper proposes a new ECG sensor card and a statistical-based ECG algorithm, with the aid of a reduced binary pattern (RBP), with the aim of achieving faster ECG human identity recognition with high accuracy. The proposed algorithm has one advantage that previous ECG algorithms lack-the waveform complex information and de-noising preprocessing can be bypassed; therefore, it is more suitable for non-stationary ECG signals. Experimental results tested on two public ECG databases (MIT-BIH) from MIT University confirm that the proposed scheme is feasible with excellent accuracy, low complexity, and speedy processing. To be more specific, the advanced RBP algorithm achieves high accuracy in human identity recognition and is executed at least nine times faster than previous algorithms. Moreover, based on the test results from a long-term ECG database, the evolving RBP algorithm also demonstrates superior capability in handling long-term and non-stationary ECG signals. PMID:26307995

  11. ECG Sensor Card with Evolving RBP Algorithms for Human Verification

    PubMed Central

    Tseng, Kuo-Kun; Huang, Huang-Nan; Zeng, Fufu; Tu, Shu-Yi

    2015-01-01

    It is known that cardiac and respiratory rhythms in electrocardiograms (ECGs) are highly nonlinear and non-stationary. As a result, most traditional time-domain algorithms are inadequate for characterizing the complex dynamics of the ECG. This paper proposes a new ECG sensor card and a statistical-based ECG algorithm, with the aid of a reduced binary pattern (RBP), with the aim of achieving faster ECG human identity recognition with high accuracy. The proposed algorithm has one advantage that previous ECG algorithms lack—the waveform complex information and de-noising preprocessing can be bypassed; therefore, it is more suitable for non-stationary ECG signals. Experimental results tested on two public ECG databases (MIT-BIH) from MIT University confirm that the proposed scheme is feasible with excellent accuracy, low complexity, and speedy processing. To be more specific, the advanced RBP algorithm achieves high accuracy in human identity recognition and is executed at least nine times faster than previous algorithms. Moreover, based on the test results from a long-term ECG database, the evolving RBP algorithm also demonstrates superior capability in handling long-term and non-stationary ECG signals. PMID:26307995

  12. High Frequency QRS ECG Accurately Detects Cardiomyopathy

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Arenare, Brian; Poulin, Gregory; Moser, Daniel R.; Delgado, Reynolds

    2005-01-01

    High frequency (HF, 150-250 Hz) analysis over the entire QRS interval of the ECG is more sensitive than conventional ECG for detecting myocardial ischemia. However, the accuracy of HF QRS ECG for detecting cardiomyopathy is unknown. We obtained simultaneous resting conventional and HF QRS 12-lead ECGs in 66 patients with cardiomyopathy (EF = 23.2 plus or minus 6.l%, mean plus or minus SD) and in 66 age- and gender-matched healthy controls using PC-based ECG software recently developed at NASA. The single most accurate ECG parameter for detecting cardiomyopathy was an HF QRS morphological score that takes into consideration the total number and severity of reduced amplitude zones (RAZs) present plus the clustering of RAZs together in contiguous leads. This RAZ score had an area under the receiver operator curve (ROC) of 0.91, and was 88% sensitive, 82% specific and 85% accurate for identifying cardiomyopathy at optimum score cut-off of 140 points. Although conventional ECG parameters such as the QRS and QTc intervals were also significantly longer in patients than controls (P less than 0.001, BBBs excluded), these conventional parameters were less accurate (area under the ROC = 0.77 and 0.77, respectively) than HF QRS morphological parameters for identifying underlying cardiomyopathy. The total amplitude of the HF QRS complexes, as measured by summed root mean square voltages (RMSVs), also differed between patients and controls (33.8 plus or minus 11.5 vs. 41.5 plus or minus 13.6 mV, respectively, P less than 0.003), but this parameter was even less accurate in distinguishing the two groups (area under ROC = 0.67) than the HF QRS morphologic and conventional ECG parameters. Diagnostic accuracy was optimal (86%) when the RAZ score from the HF QRS ECG and the QTc interval from the conventional ECG were used simultaneously with cut-offs of greater than or equal to 40 points and greater than or equal to 445 ms, respectively. In conclusion 12-lead HF QRS ECG employing

  13. ECG Monitoring in Cardiac Rehabilitation: Is It Needed?

    ERIC Educational Resources Information Center

    Greenland, Philip; Pomilla, Paul V.

    1989-01-01

    Discusses the controversial use of continuous electrocardiogram (ECG) monitoring as a safety measure in cardiac rehabilitation exercise programs. Little evidence substantiates its value for all patients during exercise. In the absence of empirical evidence documenting the worth of this expensive procedure, it is recommended for use with high-risk…

  14. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    NASA Technical Reports Server (NTRS)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  15. Improvements in ECG accuracy for diagnosis of left ventricular hypertrophy in obesity

    PubMed Central

    Rider, Oliver J; Ntusi, Ntobeko; Bull, Sacha C; Nethononda, Richard; Ferreira, Vanessa; Holloway, Cameron J; Holdsworth, David; Mahmod, Masliza; Rayner, Jennifer J; Banerjee, Rajarshi; Myerson, Saul; Watkins, Hugh; Neubauer, Stefan

    2016-01-01

    Objectives The electrocardiogram (ECG) is the most commonly used tool to screen for left ventricular hypertrophy (LVH), and yet current diagnostic criteria are insensitive in modern increasingly overweight society. We propose a simple adjustment to improve diagnostic accuracy in different body weights and improve the sensitivity of this universally available technique. Methods Overall, 1295 participants were included—821 with a wide range of body mass index (BMI 17.1–53.3 kg/m2) initially underwent cardiac magnetic resonance evaluation of anatomical left ventricular (LV) axis, LV mass and 12-lead surface ECG in order to generate an adjustment factor applied to the Sokolow–Lyon criteria. This factor was then validated in a second cohort (n=520, BMI 15.9–63.2 kg/m2). Results When matched for LV mass, the combination of leftward anatomical axis deviation and increased BMI resulted in a reduction of the Sokolow–Lyon index, by 4 mm in overweight and 8 mm in obesity. After adjusting for this in the initial cohort, the sensitivity of the Sokolow–Lyon index increased (overweight: 12.8% to 30.8%, obese: 3.1% to 27.2%) approaching that seen in normal weight (37.8%). Similar results were achieved in the validation cohort (specificity increased in overweight: 8.3% to 39.1%, obese: 9.4% to 25.0%) again approaching normal weight (39.0%). Importantly, specificity remained excellent (>93.1%). Conclusions Adjusting the Sokolow–Lyon index for BMI (overweight +4 mm, obesity +8 mm) improves the diagnostic accuracy for detecting LVH. As the ECG, worldwide, remains the most widely used screening tool for LVH, implementing these findings should translate into significant clinical benefit. PMID:27486142

  16. Centennial of the string galvanometer and the electrocardiogram.

    PubMed

    Fisch, C

    2000-11-15

    This article is a review of the history of the string galvanometer and of the electrocardiogram (ECG) on the occasion of the centennial of the instrument. Einthoven most likely developed the string galvanometer prior to 1901, the date of the first publication. The galvanometer made electrocardiography practical creating a new branch of medicine and even a new industry. In 1791 Galvani, in 1842 Mateucci and in 1855 Kolliker and Muller recorded, using the nerve muscle preparation, contraction of injured muscle, contraction of muscle when laid across a beating heart, and occasionally two contractions. In 1872 Lippmann introduced the capillary manometer. Using the capillary manometer Waller recorded for the first time from body surface voltage changes generated by the heart. Einthoven and Lewis dominated the early years of electrocardiography. The former made his contributions by 1913 while Lewis continued the studies of arrhythmias until 1920. The period following 1920 was influenced largely by Wilson. None did as much to advance ECG knowledge as did Wilson. The interest shifted to the theory of the ECG, abnormalities of wave form and of ECG leads. A major contribution of the ECG is in evaluation of ischemic heart disease and cardiac arrhythmias. Issues facing electrocardiography in the year 2000 include a shortage of experienced electrocardiographers, the advent of new noninvasive procedures and, paradoxically, wide acceptance of the ECG by the medical profession. The role of the computer in analysis of the clinical ECG is limited. The technique, while reasonably reliable for analysis of the normal tracing and some ECG waveforms, has serious limitations when applied to arrhythmias. The early hopes for "stand-alone" programs are yet to be realized.

  17. Centennial of the string galvanometer and the electrocardiogram.

    PubMed

    Fisch, C

    2000-11-15

    This article is a review of the history of the string galvanometer and of the electrocardiogram (ECG) on the occasion of the centennial of the instrument. Einthoven most likely developed the string galvanometer prior to 1901, the date of the first publication. The galvanometer made electrocardiography practical creating a new branch of medicine and even a new industry. In 1791 Galvani, in 1842 Mateucci and in 1855 Kolliker and Muller recorded, using the nerve muscle preparation, contraction of injured muscle, contraction of muscle when laid across a beating heart, and occasionally two contractions. In 1872 Lippmann introduced the capillary manometer. Using the capillary manometer Waller recorded for the first time from body surface voltage changes generated by the heart. Einthoven and Lewis dominated the early years of electrocardiography. The former made his contributions by 1913 while Lewis continued the studies of arrhythmias until 1920. The period following 1920 was influenced largely by Wilson. None did as much to advance ECG knowledge as did Wilson. The interest shifted to the theory of the ECG, abnormalities of wave form and of ECG leads. A major contribution of the ECG is in evaluation of ischemic heart disease and cardiac arrhythmias. Issues facing electrocardiography in the year 2000 include a shortage of experienced electrocardiographers, the advent of new noninvasive procedures and, paradoxically, wide acceptance of the ECG by the medical profession. The role of the computer in analysis of the clinical ECG is limited. The technique, while reasonably reliable for analysis of the normal tracing and some ECG waveforms, has serious limitations when applied to arrhythmias. The early hopes for "stand-alone" programs are yet to be realized. PMID:11092639

  18. A method of ECG template extraction for biometrics applications.

    PubMed

    Zhou, Xiang; Lu, Yang; Chen, Meng; Bao, Shu-Di; Miao, Fen

    2014-01-01

    ECG has attracted widespread attention as one of the most important non-invasive physiological signals in healthcare-system related biometrics for its characteristics like ease-of-monitoring, individual uniqueness as well as important clinical value. This study proposes a method of dynamic threshold setting to extract the most stable ECG waveform as the template for the consequent ECG identification process. With the proposed method, the accuracy of ECG biometrics using the dynamic time wraping for difference measures has been significantly improved. Analysis results with the self-built electrocardiogram database show that the deployment of the proposed method was able to reduce the half total error rate of the ECG biometric system from 3.35% to 1.45%. Its average running time on the platform of android mobile terminal was around 0.06 seconds, and thus demonstrates acceptable real-time performance. PMID:25570031

  19. ECG Signal Analysis and Arrhythmia Detection using Wavelet Transform

    NASA Astrophysics Data System (ADS)

    Kaur, Inderbir; Rajni, Rajni; Marwaha, Anupma

    2016-06-01

    Electrocardiogram (ECG) is used to record the electrical activity of the heart. The ECG signal being non-stationary in nature, makes the analysis and interpretation of the signal very difficult. Hence accurate analysis of ECG signal with a powerful tool like discrete wavelet transform (DWT) becomes imperative. In this paper, ECG signal is denoised to remove the artifacts and analyzed using Wavelet Transform to detect the QRS complex and arrhythmia. This work is implemented in MATLAB software for MIT/BIH Arrhythmia database and yields the sensitivity of 99.85 %, positive predictivity of 99.92 % and detection error rate of 0.221 % with wavelet transform. It is also inferred that DWT outperforms principle component analysis technique in detection of ECG signal.

  20. A capacitive ECG array with visual patient feedback.

    PubMed

    Eilebrecht, Benjamin; Schommartz, Antje; Walter, Marian; Wartzek, Tobias; Czaplik, Michael; Leonhardt, Steffen

    2010-01-01

    Capacitive electrocardiogram (ECG) sensing is a promising technique for less constraining vital signal measurement and close to a commercial application. Even bigger trials testing the diagnostic significance were already done with single lead systems. Anyway, most applications to be found in research are limited to one channel and thus limited in its diagnostic relevance as only diseases coming along with a change of the heart rate can be diagnosed adequately. As a consequence the need for capacitive multi-channel ECGs combining the diagnostic relevance and the advantages of capacitive ECG sensing emerges. This paper introduces a capacitive ECG measurement system which allows the recording of standardized ECG leads according to Einthoven and Goldberger by means of an electrode array with nine electrodes.

  1. A method of ECG template extraction for biometrics applications.

    PubMed

    Zhou, Xiang; Lu, Yang; Chen, Meng; Bao, Shu-Di; Miao, Fen

    2014-01-01

    ECG has attracted widespread attention as one of the most important non-invasive physiological signals in healthcare-system related biometrics for its characteristics like ease-of-monitoring, individual uniqueness as well as important clinical value. This study proposes a method of dynamic threshold setting to extract the most stable ECG waveform as the template for the consequent ECG identification process. With the proposed method, the accuracy of ECG biometrics using the dynamic time wraping for difference measures has been significantly improved. Analysis results with the self-built electrocardiogram database show that the deployment of the proposed method was able to reduce the half total error rate of the ECG biometric system from 3.35% to 1.45%. Its average running time on the platform of android mobile terminal was around 0.06 seconds, and thus demonstrates acceptable real-time performance.

  2. A novel similarity comparison approach for dynamic ECG series.

    PubMed

    Yin, Hong; Zhu, Xiaoqian; Ma, Shaodong; Yang, Shuqiang; Chen, Liqian

    2015-01-01

    The heart sound signal is a reflection of heart and vascular system motion. Long-term continuous electrocardiogram (ECG) contains important information which can be helpful to prevent heart failure. A single piece of a long-term ECG recording usually consists of more than one hundred thousand data points in length, making it difficult to derive hidden features that may be reflected through dynamic ECG monitoring, which is also very time-consuming to analyze. In this paper, a Dynamic Time Warping based on MapReduce (MRDTW) is proposed to make prognoses of possible lesions in patients. Through comparison of a real-time ECG of a patient with the reference sets of normal and problematic cardiac waveforms, the experimental results reveal that our approach not only retains high accuracy, but also greatly improves the efficiency of the similarity measure in dynamic ECG series.

  3. Application of artificial neural networks for versatile preprocessing of electrocardiogram recordings.

    PubMed

    Mateo, J; Rieta, J J

    2012-02-01

    The electrocardiogram (ECG) is the most widely used method for diagnosis of heart diseases, where a good quality of recordings allows the proper interpretation and identification of physiological and pathological phenomena. However, ECG recordings often have interference from noises including thermal, muscle, baseline and powerline noises. These signals severely limit ECG recording utility and, hence, have to be removed. To deal with this problem, the present paper proposes an artificial neural network (ANN) as a filter to remove all kinds of noise in just one step. The method is based on a growing ANN which optimizes both the number of nodes in the hidden layer and the coefficient matrices, which are optimized by means of the Widrow-Hoff delta algorithm. The ANN has been trained with a database comprising all kinds of noise, both from synthesized and real ECG recordings, in order to handle any noise signal present in the ECG. The proposed system improves results yielded by conventional techniques of ECG filtering, such as FIR-based systems, adaptive filtering and wavelet filtering. Therefore, the algorithm could serve as an effective framework to substantially reduce noise in ECG recordings. In addition, the resulting ECG signal distortion is notably more reduced in comparison with conventional methodologies. In summary, the current contribution introduces a new method which is able to suppress all ECG interference signals in only one step with low ECG distortion and a high noise reduction.

  4. "Virtual" Experiment for Understanding the Electrocardiogram and the Mean Electrical Axis.

    ERIC Educational Resources Information Center

    Anderson, Jamie; DiCarlo, Stephen E.

    2000-01-01

    Describes a virtual experiment designed to introduce students to the theory and application of the electrocardiogram (ECG) and the mean electrical axis (MEA). Students are asked to reduce and analyze data, calculate and plot the MEA, and answer questions in the inquiry-based, experimental activity. (Author/WRM)

  5. Singularity detection by wavelet approach: application to electrocardiogram signal

    NASA Astrophysics Data System (ADS)

    Jalil, Bushra; Beya, Ouadi; Fauvet, Eric; Laligant, Olivier

    2010-01-01

    In signal processing, the region of abrupt changes contains the most of the useful information about the nature of the signal. The region or the points where these changes occurred are often termed as singular point or singular region. The singularity is considered to be an important character of the signal, as it refers to the discontinuity and interruption present in the signal and the main purpose of the detection of such singular point is to identify the existence, location and size of those singularities. Electrocardiogram (ECG) signal is used to analyze the cardiovascular activity in the human body. However the presence of noise due to several reasons limits the doctor's decision and prevents accurate identification of different pathologies. In this work we attempt to analyze the ECG signal with energy based approach and some heuristic methods to segment and identify different signatures inside the signal. ECG signal has been initially denoised by empirical wavelet shrinkage approach based on Steins Unbiased Risk Estimate (SURE). At the second stage, the ECG signal has been analyzed by Mallat approach based on modulus maximas and Lipschitz exponent computation. The results from both approaches has been discussed and important aspects has been highlighted. In order to evaluate the algorithm, the analysis has been done on MIT-BIH Arrhythmia database; a set of ECG data records sampled at a rate of 360 Hz with 11 bit resolution over a 10mv range. The results have been examined and approved by medical doctors.

  6. Primary prevention of sudden cardiac death of the young athlete: the controversy about the screening electrocardiogram and its innovative artificial intelligence solution.

    PubMed

    Chang, Anthony C

    2012-03-01

    The preparticipation screening for athlete participation in sports typically entails a comprehensive medical and family history and a complete physical examination. A 12-lead electrocardiogram (ECG) can increase the likelihood of detecting cardiac diagnoses such as hypertrophic cardiomyopathy, but this diagnostic test as part of the screening process has engendered considerable controversy. The pro position is supported by argument that international screening protocols support its use, positive diagnosis has multiple benefits, history and physical examination are inadequate, primary prevention is essential, and the cost effectiveness is justified. Although the aforementioned myriad of justifications for routine ECG screening of young athletes can be persuasive, several valid contentions oppose supporting such a policy, namely, that the sudden death incidence is very (too) low, the ECG screening will be too costly, the false-positive rate is too high, resources will be allocated away from other diseases, and manpower is insufficient for its execution. Clinicians, including pediatric cardiologists, have an understandable proclivity for avoiding this prodigious national endeavor. The controversy, however, should not be focused on whether an inexpensive, noninvasive test such as an ECG should be mandated but should instead be directed at just how these tests for young athletes can be performed in the clinical imbroglio of these disease states (with variable genetic penetrance and phenotypic expression) with concomitant fiscal accountability and logistical expediency in this era of economic restraint. This monumental endeavor in any city or region requires two crucial elements well known to business scholars: implementation and execution. The eventual solution for the screening ECG dilemma requires a truly innovative and systematic approach that will liberate us from inadequate conventional solutions. Artificial intelligence, specifically the process termed "machine

  7. Primary prevention of sudden cardiac death of the young athlete: the controversy about the screening electrocardiogram and its innovative artificial intelligence solution.

    PubMed

    Chang, Anthony C

    2012-03-01

    The preparticipation screening for athlete participation in sports typically entails a comprehensive medical and family history and a complete physical examination. A 12-lead electrocardiogram (ECG) can increase the likelihood of detecting cardiac diagnoses such as hypertrophic cardiomyopathy, but this diagnostic test as part of the screening process has engendered considerable controversy. The pro position is supported by argument that international screening protocols support its use, positive diagnosis has multiple benefits, history and physical examination are inadequate, primary prevention is essential, and the cost effectiveness is justified. Although the aforementioned myriad of justifications for routine ECG screening of young athletes can be persuasive, several valid contentions oppose supporting such a policy, namely, that the sudden death incidence is very (too) low, the ECG screening will be too costly, the false-positive rate is too high, resources will be allocated away from other diseases, and manpower is insufficient for its execution. Clinicians, including pediatric cardiologists, have an understandable proclivity for avoiding this prodigious national endeavor. The controversy, however, should not be focused on whether an inexpensive, noninvasive test such as an ECG should be mandated but should instead be directed at just how these tests for young athletes can be performed in the clinical imbroglio of these disease states (with variable genetic penetrance and phenotypic expression) with concomitant fiscal accountability and logistical expediency in this era of economic restraint. This monumental endeavor in any city or region requires two crucial elements well known to business scholars: implementation and execution. The eventual solution for the screening ECG dilemma requires a truly innovative and systematic approach that will liberate us from inadequate conventional solutions. Artificial intelligence, specifically the process termed "machine

  8. Robust fetal QRS detection from noninvasive abdominal electrocardiogram based on channel selection and simultaneous multichannel processing.

    PubMed

    Ghaffari, Ali; Mollakazemi, Mohammad Javad; Atyabi, Seyyed Abbas; Niknazar, Mohammad

    2015-12-01

    The purpose of this study is to provide a new method for detecting fetal QRS complexes from non-invasive fetal electrocardiogram (fECG) signal. Despite most of the current fECG processing methods which are based on separation of fECG from maternal ECG (mECG), in this study, fetal heart rate (FHR) can be extracted with high accuracy without separation of fECG from mECG. Furthermore, in this new approach thoracic channels are not necessary. These two aspects have reduced the required computational operations. Consequently, the proposed approach can be efficiently applied to different real-time healthcare and medical devices. In this work, a new method is presented for selecting the best channel which carries strongest fECG. Each channel is scored based on two criteria of noise distribution and good fetal heartbeat visibility. Another important aspect of this study is the simultaneous and combinatorial use of available fECG channels via the priority given by their scores. A combination of geometric features and wavelet-based techniques was adopted to extract FHR. Based on fetal geometric features, fECG signals were divided into three categories, and different strategies were employed to analyze each category. The method was validated using three datasets including Noninvasive fetal ECG database, DaISy and PhysioNet/Computing in Cardiology Challenge 2013. Finally, the obtained results were compared with other studies. The adopted strategies such as multi-resolution analysis, not separating fECG and mECG, intelligent channels scoring and using them simultaneously are the factors that caused the promising performance of the method. PMID:26462679

  9. Wavelet transform and Huffman coding based electrocardiogram compression algorithm: Application to telecardiology

    NASA Astrophysics Data System (ADS)

    Chouakri, S. A.; Djaafri, O.; Taleb-Ahmed, A.

    2013-08-01

    We present in this work an algorithm for electrocardiogram (ECG) signal compression aimed to its transmission via telecommunication channel. Basically, the proposed ECG compression algorithm is articulated on the use of wavelet transform, leading to low/high frequency components separation, high order statistics based thresholding, using level adjusted kurtosis value, to denoise the ECG signal, and next a linear predictive coding filter is applied to the wavelet coefficients producing a lower variance signal. This latter one will be coded using the Huffman encoding yielding an optimal coding length in terms of average value of bits per sample. At the receiver end point, with the assumption of an ideal communication channel, the inverse processes are carried out namely the Huffman decoding, inverse linear predictive coding filter and inverse discrete wavelet transform leading to the estimated version of the ECG signal. The proposed ECG compression algorithm is tested upon a set of ECG records extracted from the MIT-BIH Arrhythmia Data Base including different cardiac anomalies as well as the normal ECG signal. The obtained results are evaluated in terms of compression ratio and mean square error which are, respectively, around 1:8 and 7%. Besides the numerical evaluation, the visual perception demonstrates the high quality of ECG signal restitution where the different ECG waves are recovered correctly.

  10. Myocardial infarction with an initially normal electrocardiogram--angiographic findings.

    PubMed

    Caceres, L; Cooke, D; Zalenski, R; Rydman, R; Lakier, J B

    1995-10-01

    To analyze the paradox of acute myocardial infarction (AMI) with an initially normal electrocardiogram (ECG), we reviewed the records of 732 patients discharged with a final diagnosis of AMI over a 2-year period. Twenty-one patient were identified whose initial ECG was normal and who underwent coronary arteriography during the index hospitalization. According to the ECG evolution, three distinct groups were identified: Group 1: those who subsequently developed ST elevation or Q waves (n = 7), Group 2: those who developed ST depression or T-wave inversion (n = 8), and Group 3: those whose ECG remained normal ( n = 6). Peak creatine kinase (CK), timing of the first ECG change, life-threatening complications, and location of the infarct-related coronary lesion were recorded. Infarct-related coronary lesions were also classified into those in a major coronary trunk versus those in secondary branches. The incidence of AMI with a normal ECG was 3.7%. There was no difference in the frequency of coronary artery involvement in the groups studied: left anterior descending (33%), right coronary artery (38%), and circumflex (28%). All ECG changes developed within the first 48 h of hospitalization; 17 +/- 15 in Group 1, and 24 +/- 12 h in Group 2. All six patients who had a persistently normal ECG (Group 3) had lesions in branch vessels (p < 0.05 when compared with Group 1 plus Group 2). Patients who developed ST elevation or Q waves (Group 1) always had a major artery trunk involved (p < 0.05 when compared with Group 2 plus Group 3). Patients in Group 3 had less myocardial damage and fewer complications compared with the other two groups. Myocardial infarction with an initial normal ECG is uncommon and may result from involvement of any of the three coronary arteries. Electrocardiographic evolution usually occurs within the first 48 h of hospitalization. Patients whose ECGs remain normal appear to have culprit lesions in coronary branches, smaller infarctions, and fewer in

  11. Empirical mode decomposition of the ECG signal for noise removal

    NASA Astrophysics Data System (ADS)

    Khan, Jesmin; Bhuiyan, Sharif; Murphy, Gregory; Alam, Mohammad

    2011-04-01

    Electrocardiography is a diagnostic procedure for the detection and diagnosis of heart abnormalities. The electrocardiogram (ECG) signal contains important information that is utilized by physicians for the diagnosis and analysis of heart diseases. So good quality ECG signal plays a vital role for the interpretation and identification of pathological, anatomical and physiological aspects of the whole cardiac muscle. However, the ECG signals are corrupted by noise which severely limit the utility of the recorded ECG signal for medical evaluation. The most common noise presents in the ECG signal is the high frequency noise caused by the forces acting on the electrodes. In this paper, we propose a new ECG denoising method based on the empirical mode decomposition (EMD). The proposed method is able to enhance the ECG signal upon removing the noise with minimum signal distortion. Simulation is done on the MIT-BIH database to verify the efficacy of the proposed algorithm. Experiments show that the presented method offers very good results to remove noise from the ECG signal.

  12. Improved wavelet packet compression of electrocardiogram data: 1. noise filtering

    NASA Astrophysics Data System (ADS)

    Bradie, Brian D.

    1995-09-01

    The improvement in the performance of a wavelet packet based compression scheme for single lead electrocardiogram (ECG) data, obtained by prefiltering noise from the ECG signals, is investigated. The removal of powerline interference and the attenuation of high-frequency muscle noise are considered. Selected records from the MIT-BIH Arrhythmia Database are used as test signals. After both types of noise artifact were filtered, an average data rate of 167.6 bits per second (corresponding to a compression ratio of 23.62), with an average root mean-square (rms) error of 15.886 (mu) V, was achieved. These figures represent better than a 9% improvement in data rate and a 13.5% reduction in rms error over compressing the unfiltered signals.

  13. Sequential Total Variation Denoising for the Extraction of Fetal ECG from Single-Channel Maternal Abdominal ECG

    PubMed Central

    Lee, Kwang Jin; Lee, Boreom

    2016-01-01

    Fetal heart rate (FHR) is an important determinant of fetal health. Cardiotocography (CTG) is widely used for measuring the FHR in the clinical field. However, fetal movement and blood flow through the maternal blood vessels can critically influence Doppler ultrasound signals. Moreover, CTG is not suitable for long-term monitoring. Therefore, researchers have been developing algorithms to estimate the FHR using electrocardiograms (ECGs) from the abdomen of pregnant women. However, separating the weak fetal ECG signal from the abdominal ECG signal is a challenging problem. In this paper, we propose a method for estimating the FHR using sequential total variation denoising and compare its performance with that of other single-channel fetal ECG extraction methods via simulation using the Fetal ECG Synthetic Database (FECGSYNDB). Moreover, we used real data from PhysioNet fetal ECG databases for the evaluation of the algorithm performance. The R-peak detection rate is calculated to evaluate the performance of our algorithm. Our approach could not only separate the fetal ECG signals from the abdominal ECG signals but also accurately estimate the FHR. PMID:27376296

  14. Electrocardiogram analysis of the normal unanesthetized green peafowl (Pavo muticus).

    PubMed

    Hassanpour, H; Hojjati, P; Zarei, H

    2011-01-01

    The aim of this study was to describe normal electrocardiogram (ECG) patterns and values in unanesthetized green peafowl (Pavo muticus). The standard bipolar and augmented unipolar limb leads ECGs were recorded in the birds. The waveforms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine P, PR (segment and interval), QRS, ST, QT durations, P, net QRS complex and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated using leads II and III. The mean heart rates were calculated from lead II that was 257.5 ± 5.33 beats/min. The P wave was dominantly positive in all leads. The dominant pattern of waveforms of the QRS complexes were QS in leads II, III, and aVF. In leads I, aVR and aVL, the R pattern was dominant. The T wave was almost positive in leads I, II, and aVF. The average value of the heart MEA was -96.75 ± 3.31°. Description of normal ECG parameters will facilitate a better realizing of ECG changes of unhealthy green peafowls.

  15. Electrocardiogram analysis of the normal unanesthetized green peafowl (Pavo muticus).

    PubMed

    Hassanpour, H; Hojjati, P; Zarei, H

    2011-01-01

    The aim of this study was to describe normal electrocardiogram (ECG) patterns and values in unanesthetized green peafowl (Pavo muticus). The standard bipolar and augmented unipolar limb leads ECGs were recorded in the birds. The waveforms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine P, PR (segment and interval), QRS, ST, QT durations, P, net QRS complex and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated using leads II and III. The mean heart rates were calculated from lead II that was 257.5 ± 5.33 beats/min. The P wave was dominantly positive in all leads. The dominant pattern of waveforms of the QRS complexes were QS in leads II, III, and aVF. In leads I, aVR and aVL, the R pattern was dominant. The T wave was almost positive in leads I, II, and aVF. The average value of the heart MEA was -96.75 ± 3.31°. Description of normal ECG parameters will facilitate a better realizing of ECG changes of unhealthy green peafowls. PMID:21971912

  16. Steganography in arrhythmic electrocardiogram signal.

    PubMed

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach. PMID:26736533

  17. Steganography in arrhythmic electrocardiogram signal.

    PubMed

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  18. ECG scores for a triage of patients with acute myocardial infarction transported by the emergency medical system.

    PubMed

    Zalenski, R J; Grzybowski, M; Ross, M A; Blaustein, N; Bock, B

    2000-01-01

    Prehospital triage of cardiac patients for bypass from community hospitals to cardiac centers may improve survival. This article determines if electrocardiogram (ECG)-based scoring triage methods (Aldrich MI scoring, QRS distortion, and the TIMI classification) and location of infarct (via 12 lead ECG) are associated with mortality before and after adjusting for age, sex, and race. It is a retrospective study of 291 AMI adult patients transported by ambulance to community hospitals or cardiac centers. Patients with an ED chief complaint of chest pain or dyspnea, presence of MI as defined by ECG findings of 0.1 mV of ST segment elevation in two leads or positive CPK-MB were eligible for the study. The primary outcome variable was 2-year mortality as determined with a metropolitan Detroit tri-county death index. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (with 95% CIs) of the predictor variables with mortality. Of the initial population selected for the study (n = 291), 229 patients were eligible for the analysis. The mean age was 66 years (SD of 14.4) with 63.8% being male and 54% being white. The overall mortality point estimate was 21.3% (95% CI of 15.2 to 27.3%). Aldrich scores and QRS distortion (yes/no) were not associated with mortality. Patients classified as a "high risk" for AMI per TIMI status were almost 3 times more likely to die than those at "low risk" and reached borderline statistical significance (P = .06) after adjusting for the covariates. Having an anterior infarct, as opposed to an inferior infarct, was significantly associated with death before and after adjusting for the covariates (Unadjusted OR = 2.6, Adjusted OR = 2.8). Properly training emergency medical system professionals in this area may prove useful for identifying higher risk AMI patients in the prehospital setting. PMID:11265729

  19. Microprocessor-Based Ambulatory ECG Monitoring System

    PubMed Central

    Le-Huy, P.; L'Huillier, J.P.; Oumerzouk, Y.; Yvroud, E.

    1983-01-01

    Ambulatory monitoring of electrocardiograms (ECGs) was facilitated by the introduction of Holter method in the early '60s. Since this time, many researchs have been undertaken in order to improve the overall performances of the recorder and analyser, two unseparated parts of this method. The principal drawbacks of Holter method are well-known: • Recording of ECG is based on the assumption that the arrhythmia of interest will be occurred in monitoring period. • Analysis and arrhythmia detection could be processed only after the monitoring period. This is a time-consuming and tedious job, and subjected to human error. • Process “Recording-Play-back - Analysis - Diagnosis” takes usually many days. In this paper, the design of a microprocessor - based portable recorder will be described. The analysis and classification of arrhythmia are processed immediately upon their occurrence according to a look-up table, which could be programmed to suit a particular need.

  20. Robust and accurate anomaly detection in ECG artifacts using time series motif discovery.

    PubMed

    Sivaraks, Haemwaan; Ratanamahatana, Chotirat Ann

    2015-01-01

    Electrocardiogram (ECG) anomaly detection is an important technique for detecting dissimilar heartbeats which helps identify abnormal ECGs before the diagnosis process. Currently available ECG anomaly detection methods, ranging from academic research to commercial ECG machines, still suffer from a high false alarm rate because these methods are not able to differentiate ECG artifacts from real ECG signal, especially, in ECG artifacts that are similar to ECG signals in terms of shape and/or frequency. The problem leads to high vigilance for physicians and misinterpretation risk for nonspecialists. Therefore, this work proposes a novel anomaly detection technique that is highly robust and accurate in the presence of ECG artifacts which can effectively reduce the false alarm rate. Expert knowledge from cardiologists and motif discovery technique is utilized in our design. In addition, every step of the algorithm conforms to the interpretation of cardiologists. Our method can be utilized to both single-lead ECGs and multilead ECGs. Our experiment results on real ECG datasets are interpreted and evaluated by cardiologists. Our proposed algorithm can mostly achieve 100% of accuracy on detection (AoD), sensitivity, specificity, and positive predictive value with 0% false alarm rate. The results demonstrate that our proposed method is highly accurate and robust to artifacts, compared with competitive anomaly detection methods.

  1. A Precise Drunk Driving Detection Using Weighted Kernel Based on Electrocardiogram

    PubMed Central

    Wu, Chung Kit; Tsang, Kim Fung; Chi, Hao Ran; Hung, Faan Hei

    2016-01-01

    Globally, 1.2 million people die and 50 million people are injured annually due to traffic accidents. These traffic accidents cost $500 billion dollars. Drunk drivers are found in 40% of the traffic crashes. Existing drunk driving detection (DDD) systems do not provide accurate detection and pre-warning concurrently. Electrocardiogram (ECG) is a proven biosignal that accurately and simultaneously reflects human’s biological status. In this letter, a classifier for DDD based on ECG is investigated in an attempt to reduce traffic accidents caused by drunk drivers. At this point, it appears that there is no known research or literature found on ECG classifier for DDD. To identify drunk syndromes, the ECG signals from drunk drivers are studied and analyzed. As such, a precise ECG-based DDD (ECG-DDD) using a weighted kernel is developed. From the measurements, 10 key features of ECG signals were identified. To incorporate the important features, the feature vectors are weighted in the customization of kernel functions. Four commonly adopted kernel functions are studied. Results reveal that weighted feature vectors improve the accuracy by 11% compared to the computation using the prime kernel. Evaluation shows that ECG-DDD improved the accuracy by 8% to 18% compared to prevailing methods. PMID:27171090

  2. Electrocardiogram Based Identification using a New Effective Intelligent Selection of Fused Features

    PubMed Central

    Abbaspour, Hamidreza; Razavi, Seyyed Mohammad; Mehrshad, Nasser

    2015-01-01

    Over the years, the feasibility of using Electrocardiogram (ECG) signal for human identification issue has been investigated, and some methods have been suggested. In this research, a new effective intelligent feature selection method from ECG signals has been proposed. This method is developed in such a way that it is able to select important features that are necessary for identification using analysis of the ECG signals. For this purpose, after ECG signal preprocessing, its characterizing features were extracted and then compressed using the cosine transform. The more effective features in the identification, among the characterizing features, are selected using a combination of the genetic algorithm and artificial neural networks. The proposed method was tested on three public ECG databases, namely, MIT-BIH Arrhythmias Database, MITBIH Normal Sinus Rhythm Database and The European ST-T Database, in order to evaluate the proposed subject identification method on normal ECG signals as well as ECG signals with arrhythmias. Identification rates of 99.89% and 99.84% and 99.99% are obtained for these databases respectively. The proposed algorithm exhibits remarkable identification accuracies not only with normal ECG signals, but also in the presence of various arrhythmias. Simulation results showed that the proposed method despite the low number of selected features has a high performance in identification task. PMID:25709939

  3. A Precise Drunk Driving Detection Using Weighted Kernel Based on Electrocardiogram.

    PubMed

    Wu, Chung Kit; Tsang, Kim Fung; Chi, Hao Ran; Hung, Faan Hei

    2016-01-01

    Globally, 1.2 million people die and 50 million people are injured annually due to traffic accidents. These traffic accidents cost $500 billion dollars. Drunk drivers are found in 40% of the traffic crashes. Existing drunk driving detection (DDD) systems do not provide accurate detection and pre-warning concurrently. Electrocardiogram (ECG) is a proven biosignal that accurately and simultaneously reflects human's biological status. In this letter, a classifier for DDD based on ECG is investigated in an attempt to reduce traffic accidents caused by drunk drivers. At this point, it appears that there is no known research or literature found on ECG classifier for DDD. To identify drunk syndromes, the ECG signals from drunk drivers are studied and analyzed. As such, a precise ECG-based DDD (ECG-DDD) using a weighted kernel is developed. From the measurements, 10 key features of ECG signals were identified. To incorporate the important features, the feature vectors are weighted in the customization of kernel functions. Four commonly adopted kernel functions are studied. Results reveal that weighted feature vectors improve the accuracy by 11% compared to the computation using the prime kernel. Evaluation shows that ECG-DDD improved the accuracy by 8% to 18% compared to prevailing methods. PMID:27171090

  4. Biosignal PI, an Affordable Open-Source ECG and Respiration Measurement System

    PubMed Central

    Abtahi, Farhad; Snäll, Jonatan; Aslamy, Benjamin; Abtahi, Shirin; Seoane, Fernando; Lindecrantz, Kaj

    2015-01-01

    Bioimedical pilot projects e.g., telemedicine, homecare, animal and human trials usually involve several physiological measurements. Technical development of these projects is time consuming and in particular costly. A versatile but affordable biosignal measurement platform can help to reduce time and risk while keeping the focus on the important goal and making an efficient use of resources. In this work, an affordable and open source platform for development of physiological signals is proposed. As a first step an 8–12 leads electrocardiogram (ECG) and respiration monitoring system is developed. Chips based on iCoupler technology have been used to achieve electrical isolation as required by IEC 60601 for patient safety. The result shows the potential of this platform as a base for prototyping compact, affordable, and medically safe measurement systems. Further work involves both hardware and software development to develop modules. These modules may require development of front-ends for other biosignals or just collect data wirelessly from different devices e.g., blood pressure, weight, bioimpedance spectrum, blood glucose, e.g., through Bluetooth. All design and development documents, files and source codes will be available for non-commercial use through project website, BiosignalPI.org. PMID:25545268

  5. Human Identification Using Compressed ECG Signals.

    PubMed

    Camara, Carmen; Peris-Lopez, Pedro; Tapiador, Juan E

    2015-11-01

    As a result of the increased demand for improved life styles and the increment of senior citizens over the age of 65, new home care services are demanded. Simultaneously, the medical sector is increasingly becoming the new target of cybercriminals due the potential value of users' medical information. The use of biometrics seems an effective tool as a deterrent for many of such attacks. In this paper, we propose the use of electrocardiograms (ECGs) for the identification of individuals. For instance, for a telecare service, a user could be authenticated using the information extracted from her ECG signal. The majority of ECG-based biometrics systems extract information (fiducial features) from the characteristics points of an ECG wave. In this article, we propose the use of non-fiducial features via the Hadamard Transform (HT). We show how the use of highly compressed signals (only 24 coefficients of HT) is enough to unequivocally identify individuals with a high performance (classification accuracy of 0.97 and with identification system errors in the order of 10(-2)). PMID:26364201

  6. ECG biometric identification: A compression based approach.

    PubMed

    Bras, Susana; Pinho, Armando J

    2015-08-01

    Using the electrocardiogram signal (ECG) to identify and/or authenticate persons are problems still lacking satisfactory solutions. Yet, ECG possesses characteristics that are unique or difficult to get from other signals used in biometrics: (1) it requires contact and liveliness for acquisition (2) it changes under stress, rendering it potentially useless if acquired under threatening. Our main objective is to present an innovative and robust solution to the above-mentioned problem. To successfully conduct this goal, we rely on information-theoretic data models for data compression and on similarity metrics related to the approximation of the Kolmogorov complexity. The proposed measure allows the comparison of two (or more) ECG segments, without having to follow traditional approaches that require heartbeat segmentation (described as highly influenced by external or internal interferences). As a first approach, the method was able to cluster the data in three groups: identical record, same participant, different participant, by the stratification of the proposed measure with values near 0 for the same participant and closer to 1 for different participants. A leave-one-out strategy was implemented in order to identify the participant in the database based on his/her ECG. A 1NN classifier was implemented, using as distance measure the method proposed in this work. The classifier was able to identify correctly almost all participants, with an accuracy of 99% in the database used. PMID:26737619

  7. Amplifier input impedance in dry electrode ECG recording.

    PubMed

    Assambo, Cedric; Burke, Martin J

    2009-01-01

    This paper presents a novel approach for designing the front-end of instrumentation amplifiers for use in dry electrode recording of the human electrocardiogram (ECG). The method relies on information provided by the characterization of the skin-electrode interface and the analysis of low frequency ECG criteria defined by international standards. Marginal measurements of capacitive elements of the skin-electrode interface as small as 0.01 microF, suggest values of input impedance in the order of 1.3 GOmega. However, results in 99% of the data analyzed indicate that a recording amplifier providing an input impedance of 500 MOmega should ensure clear signal sensing without distortion.

  8. Diagnostic Value of Electrocardiogram in Predicting Exaggerated Blood Pressure Response to Exercise Stress Testing

    PubMed Central

    Eshraghi, Ali; Ebdali, Reyhaneh Takalloo; Sajjadi, Seyed Sajed; Golnezhad, Reza

    2016-01-01

    Introduction It is believed that an exaggerated blood pressure response (EBPR) to exercise stress test is associated with a higher risk of cardiovascular events. It is also assumed that QT dispersion (QT-d), which was originally proposed to measure the spatial dispersion of ventricular recovery times, may have a relationship to cardiovascular events. The objective of this study was to examine the difference of changes in QT-d, Maxi-QT, Mini-QT, and QT-c (corrected QT interval) of the electrocardiogram in two groups of patients with exaggerated blood pressure responses (EBPR group) and normal responses (control group) to exercise testing. Also, the diagnostic value of each of these criteria in the prediction of EBPR was studied. Methods This cross-sectional study was conducted from May 2015 to February 2016 on patients suspected of coronary artery disease (CAD) undergoing exercise testing who had been referred to Ghaem and Imam Reza hospitals in Mashhad (Iran). All patients underwent a treadmill exercise test with the 12-lead ECG, which was optically scanned and digitized for analysis of QT-d, QT max, and QT min. Patients were divided into two groups of normal and EBPR to exercise testing. QT changes of ECG were compared between the two groups, and the diagnostic accuracy of QT variables for prediction of EBPR to exercise testing was studied. A multiple linear regression analysis (MLR), Pearson Chi-qquare, independent samples t-test, and receiver operating characteristic (ROC) curve were used as statistical methods in IBM SPSS version 19. Results Sixty patients (55% male) with a mean age of 50.48 ± 10.89 years were studied in two groups of normal (n=30) and exaggerated blood pressure response (n=30) to exercise testing. Maximum QT and QT dispersion were statistically different in individuals’ exaggerated blood pressure response to exercise stress test (p < 0.05). The logistic regression analysis revealed that none of our parameters predicted the EBPR. The ROC

  9. ECG signals denoising using wavelet transform and independent component analysis

    NASA Astrophysics Data System (ADS)

    Liu, Manjin; Hui, Mei; Liu, Ming; Dong, Liquan; Zhao, Zhu; Zhao, Yuejin

    2015-08-01

    A method of two channel exercise electrocardiograms (ECG) signals denoising based on wavelet transform and independent component analysis is proposed in this paper. First of all, two channel exercise ECG signals are acquired. We decompose these two channel ECG signals into eight layers and add up the useful wavelet coefficients separately, getting two channel ECG signals with no baseline drift and other interference components. However, it still contains electrode movement noise, power frequency interference and other interferences. Secondly, we use these two channel ECG signals processed and one channel signal constructed manually to make further process with independent component analysis, getting the separated ECG signal. We can see the residual noises are removed effectively. Finally, comparative experiment is made with two same channel exercise ECG signals processed directly with independent component analysis and the method this paper proposed, which shows the indexes of signal to noise ratio (SNR) increases 21.916 and the root mean square error (MSE) decreases 2.522, proving the method this paper proposed has high reliability.

  10. Diagnostic Role of ECG Recording Simultaneously With EEG Testing.

    PubMed

    Kendirli, Mustafa Tansel; Aparci, Mustafa; Kendirli, Nurten; Tekeli, Hakan; Karaoglan, Mustafa; Senol, Mehmet Guney; Togrol, Erdem

    2015-07-01

    Arrhythmia is not uncommon in the etiology of syncope which mimics epilepsy. Data about the epilepsy induced vagal tonus abnormalities have being increasingly reported. So we aimed to evaluate what a neurologist may gain by a simultaneous electrocardiogram (ECG) and electroencephalogram (EEG) recording in the patients who underwent EEG testing due to prediagnosis of epilepsy. We retrospectively evaluated and detected ECG abnormalities in 68 (18%) of 376 patients who underwent EEG testing. A minimum of 20 of minutes artifact-free recording were required for each patient. Standard 1-channel ECG was simultaneously recorded in conjunction with the EEG. In all, 28% of females and 14% of males had ECG abnormalities. Females (mean age 49 years, range 18-88 years) were older compared with the male group (mean age 28 years, range 16-83 years). Atrial fibrillation was more frequent in female group whereas bradycardia and respiratory sinus arrhythmia was higher in male group. One case had been detected a critical asystole indicating sick sinus syndrome in the female group and treated with a pacemaker implantation in the following period. Simultaneous ECG recording in conjunction with EEG testing is a clinical prerequisite to detect and to clarify the coexisting ECG and EEG abnormalities and their clinical relevance. Potentially rare lethal causes of syncope that mimic seizure or those that could cause resistance to antiepileptic therapy could effectively be distinguished by detecting ECG abnormalities coinciding with the signs and abnormalities during EEG recording.

  11. Real time ECG artifact removal for myoelectric prosthesis control.

    PubMed

    Zhou, Ping; Lock, Blair; Kuiken, Todd A

    2007-04-01

    The electrocardiogram (ECG) artifact is a major noise source contaminating the electromyogram (EMG) of torso muscles. This study investigates removal of ECG artifacts in real time for myoelectric prosthesis control, a clinical application that demands speed and efficiency. Three methods with simple and fast implementation were investigated. Removal of ECG artifacts by digital high-pass filtering was implemented. The effects of the cutoff frequency and filter order of high-pass filtering on the resulting EMG signal were quantified. An alternative adaptive spike-clipping approach was also developed to dynamically detect and suppress the ECG artifacts in the signal. Finally, the two methods were combined. Experimental surface EMG recordings with different ECG/EMG ratios were used as testing signals to evaluate the proposed methods. As a key parameter for clinical myoelectric prosthesis control, the average rectified amplitude of the signal was used as the performance indicator to quantitatively analyze the EMG content distortion and the ECG artifact suppression imposed by the two methods. Aiming at clinical application, the optimal parameter assignment for each method was determined on the basis of the performance using the suite of testing signals with various ECG/EMG ratios. PMID:17395995

  12. The application of wavelet and feature vectors to ECG signals.

    PubMed

    Matsuyama, A; Jonkman, M

    2006-03-01

    The Electrocardiogram (ECG) is one of the most commonly known biological signals. Traditionally ECG recordings are analysed in the time-domain by skilled physicians. However, pathological conditions may not always be obvious in the original time-domain signal. Fourier analysis provides frequency information but has the disadvantage that time characteristics will be lost. Wavelet analysis, which provides both time and frequency information, can overcome this limitation. Here a new method, the combination of wavelet analysis and feature vectors, is applied with the intent to investigate its suitability as a diagnostic tool. ECG signals with normal and abnormal beats were examined. There were two stages in analysing ECG signals: feature extraction and feature classification. To extract features from ECG signals, wavelet decomposition was first applied and feature vectors of normalised energy and entropy were constructed. These feature vectors were used to classify signals. The results showed that normal beats and abnormal beats composed different clusters in most cases. In conclusion, the combination of wavelet transform and feature vectors has shown potential in detecting abnormalities in an ECG recording. It was also found that normalised energy and entropy are features, which are suitable for classification of ECG signals.

  13. Some regularity on how to locate electrodes for higher fECG SNRs

    NASA Astrophysics Data System (ADS)

    Zhang, Jie-Min; Huang, Xiao-Lin; Guan, Qun; Liu, Tie-Bing; Li, Ping; Zhao, Ying; Liu, Hong-Xing

    2015-03-01

    The electrocardiogram (ECG) recorded from the abdominal surface of a pregnant woman is a composite of maternal ECG, fetal ECG (fECG) and other noises, while only the fECG component is always needed by us. With different locations of electrode pairs on the maternal abdominal surface to measure fECGs, the signal-to-noise ratios (SNRs) of the recorded abdominal ECGs are also correspondingly different. Some regularity on how to locate electrodes to obtain higher fECG SNRs is needed practically. In this paper, 343 groups of abdominal ECG records were acquired from 78 pregnant women with different electrode pairs locating, and an appropriate extended research database is formed. Then the regularity on fECG SNRs corresponding to different electrode pairs locating was studied. Based on statistical analysis, it is shown that the fECG SNRs are significantly higher in certain locations than others. Reasonable explanation is also provided to the statistical result using the theories of the fetal cardiac electrical axis and the signal phase delay. Project supported by the National Natural Science Foundation of China (Grant No. 61271079) and the Supporting Plan Project of Jiangsu Province, China (Grant No. BE2010720).

  14. Correlation method of electrocardiogram analysis

    NASA Astrophysics Data System (ADS)

    Strinadko, Marina M.; Timochko, Katerina B.

    2002-02-01

    The electrocardiograph method is the informational source for functional heart state characteristics. The electrocardiogram parameters are the integrated map of many component characteristics of the heart system and depend on disturbance requirements of each device. In the research work the attempt of making the skeleton diagram of perturbation of the heart system is made by the characteristic description of its basic components and connections between them through transition functions, which are written down by the differential equations of the first and second order with the purpose to build-up and analyze electrocardiogram. Noting the vector character of perturbation and the various position of heart in each organism, we offer own coordinate system connected with heart. The comparative analysis of electrocardiogram was conducted with the usage of correlation method.

  15. The use of a portable three-lead ECG monitor to detect atrial fibrillation in general practice

    PubMed Central

    Kristensen, Anne N.; Jeyam, Brintha; Riahi, Sam; Jensen, Martin B.

    2016-01-01

    Objective To evaluate how well an inexpensive portable three-lead ECG monitor PEM identified patients with atrial fibrillation (AF) compared to a normal 12-lead ECG. Design Cross-sectional method comparison study. Setting From April 2014 to February 2015, we included patients coming to the general practice clinic “Lægerne Sløjfen”, Aalborg, Denmark for a routine ECG. Patients with severe dementia, mental illness or poor ECG readings were excluded. After oral and written informed consent an ECG and PEM recordings were obtained simultaneously. The PEM recordings were analyzed by two general practitioners (GPs) in training and ECG recordings were evaluated by a senior GP and a cardiologist. Both the PEM and the ECG recordings were analysed blinded. Subjects Ninety-three patients were included and four were excluded due to poor ECG readings. Main outcome measures The sensitivity and specificity of PEM compared to a standard 12-lead ECG. Results Eighty-nine of the 93 (95.7%) patients had ECGs of a satisfactory technical quality and were included in the study. The sensitivity of diagnosing AF by PEM recordings was 86.7% and the specificity was 98.7% when compared to a 12-lead ECG. According to the cardiologist, the misclassification of three PEM recordings were due to interpretation errors and not related to the PEM recording per se. Conclusions The inexpensive portable PEM device recording diagnosed AF with a high sensitivity and specificity. Key Points Simple ECG monitors could be useful to identify atrial fibrillation and thereby lead to a better prevention of stroke.The PEM device was easy to use and 95.7% of the recordings were technically acceptable for detecting atrial fibrillation.The PEM device has a high sensitivity and specificity in detecting atrial fibrillation compared to a standard 12-lead ECG.Further studies should evaluate the clinical usefulness of the PEM device, e.g. to detect intermittent atrial fibrillation. PMID:27409151

  16. Improving automatic analysis of the electrocardiogram acquired during magnetic resonance imaging using magnetic field gradient artefact suppression.

    PubMed

    Abächerli, Roger; Hornaff, Sven; Leber, Remo; Schmid, Hans-Jakob; Felblinger, Jacques

    2006-10-01

    The electrocardiogram (ECG) used for patient monitoring during magnetic resonance imaging (MRI) unfortunately suffers from severe artefacts. These artefacts are due to the special environment of the MRI. Modeling helped in finding solutions for the suppression of these artefacts superimposed on the ECG signal. After we validated the linear and time invariant model for the magnetic field gradient artefact generation, we applied offline and online filters for their suppression. Wiener filtering (offline) helped in generating reference annotations of the ECG beats. In online filtering, the least-mean-square filter suppressed the magnetic field gradient artefacts before the acquired ECG signal was input to the arrhythmia algorithm. Comparing the results of two runs (one run using online filtering and one run without) to our reference annotations, we found an eminent improvement in the arrhythmia module's performance, enabling reliable patient monitoring and MRI synchronization based on the ECG signal. PMID:17015063

  17. DIETARY SODIUM ALTERS THE PREVALENCE OF ELECTROCARDIOGRAM DETERMINED LEFT VENTRICULAR HYPERTROPHY IN HYPERTENSION

    PubMed Central

    Vaidya, Anand; Bentley-Lewis, Rhonda; Jeunemaitre, Xavier; Adler, Gail K.; Williams, Jonathan S.

    2010-01-01

    BACKGROUND Determination of left ventricular hypertrophy (LVH) via electrocardiogram (ECG) is a known independent risk factor for cardiovascular morbidity and mortality in hypertension. Dietary sodium and hypertension are both associated with unfavorable alterations in left ventricular mass, however to what extent their interplay affects ECG screening for LVH is unclear. METHODS The effects of controlled dietary sodium manipulation on ECG determinants of LVH in hypertensive subjects were evaluated using well established voltage criteria for LVH. ECG’s from 80 hypertensive subjects were evaluated following random sequence assignment to 7 days of high sodium (HS) intake (200 mEq/24h), and then 7 days of low sodium (LS) intake (10 mEq/24h). RESULTS Sodium restriction over 7 days resulted in significant decreases in overall, and LVH-specific, ECG voltages. Most subjects (72%) exhibited decrements in overall ECG voltage with sodium restriction, but a smaller minority (28%) displayed higher voltages when on LS intake (28%). The prevalence of ECG-determined LVH significantly declined with LS diet (HS diet 22/80 [28%] vs. LS diet 8/80 [10%], p<0.05). Subjects exhibiting reversal of LVH status with sodium restriction were younger, demonstrated salt-sensitivity of blood pressure, and lower LVH-specific ECG voltage. CONCLUSIONS Short-term dietary sodium fluctuations can significantly alter overall ECG voltage and the prevalence of ECG-determined LVH in hypertensive individuals. Inclusion of dietary sodium assessment when screening hypertensive subjects for LVH by ECG may improve the consistency of cardiac risk assessment. PMID:19265788

  18. Use of concept maps to promote electrocardiogram diagnosis learning in undergraduate medical students.

    PubMed

    Dong, Ruimin; Yang, Xiaoyan; Xing, Bangrong; Zou, Zihao; Zheng, Zhenda; Xie, Xujing; Zhu, Jieming; Chen, Lin; Zhou, Hanjian

    2015-01-01

    Concept mapping is an effective method in teaching and learning, however this strategy has not been evaluated among electrocardiogram (ECG) diagnosis learning. This study explored the use of concept maps to assist ECG study, and sought to analyze whether this method could improve undergraduate students' ECG interpretation skills. There were 126 undergraduate medical students who were randomly selected and assigned to two groups, group A (n = 63) and group B (n = 63). Group A was taught to use concept maps to learn ECG diagnosis, while group B was taught by traditional methods. After the course, all of the students were assessed by having an ECG diagnostic test. Quantitative data which comprised test score and ECG features completion index was compared by using the unpaired Student's t-test between the two groups. Further, a feedback questionnaire on concept maps used was also completed by group A, comments were evaluated by a five-point Likert scale. The test scores of ECGs interpretation was 7.36 ± 1.23 in Group A and 6.12 ± 1.39 in Group B. A significant advantage (P = 0.018) of concept maps was observed in ECG interpretation accuracy. No difference in the average ECG features completion index was observed between Group A (66.75 ± 15.35%) and Group B (62.93 ± 13.17%). According qualitative analysis, majority of students accepted concept maps as a helpful tool. Difficult to learn at the beginning and time consuming are the two problems in using this method, nevertheless most of the students indicated to continue using it. Concept maps could be a useful pedagogical tool in enhancing undergraduate medical students' ECG interpretation skills. Furthermore, students indicated a positive attitude to it, and perceived it as a resource for learning.

  19. Mobile Messaging Services-Based Personal Electrocardiogram Monitoring System

    PubMed Central

    Tahat, Ashraf A.

    2009-01-01

    A mobile monitoring system utilizing Bluetooth and mobile messaging services (MMS/SMSs) with low-cost hardware equipment is proposed. A proof of concept prototype has been developed and implemented to enable transmission of an Electrocardiogram (ECG) signal and body temperature of a patient, which can be expanded to include other vital signs. Communication between a mobile smart-phone and the ECG and temperature acquisition apparatus is implemented using the popular personal area network standard specification Bluetooth. When utilizing MMS for transmission, the mobile phone plots the received ECG signal and displays the temperature using special application software running on the client mobile phone itself, where the plot can be captured and saved as an image before transmission. Alternatively, SMS can be selected as a transmission means, where in this scenario, dedicated application software is required at the receiving device. The experimental setup can be operated for monitoring from anywhere in the globe covered by a cellular network that offers data services. PMID:19707531

  20. Alterations in the rat electrocardiogram induced by stationary magnetic fields

    SciTech Connect

    Gaffey, C.T.; Tenforde, T.S.

    1981-01-01

    A field strength dependent increase in the amplitude of the T-wave signal in the rat electrocardiogram (ECG) was observed during exposure to homogeneous, stationary magnetic fields. For 24 adult Sprague-Dswley and Buffalo rats of both sexes, the T-wave amplitude was found to increase by an average of 408% in a 2.0 Tesla (1 Tesla = 10/sup 4/ Gauss) field. No significant magnetically induced changes were observed in other components of the ECG record, including the P wave and the QRS complex. The minimum field level at which augmentation of the T wave could be detected was 0.3 Tesla. The magnetically induced increase in T-wave amplitude occurred instantaneously, and was immediately reversible after exposure to fields as high as 2.0 Tesla. No abnormalities in any component of the ECG record, including the T wave, were noted during a period of 3 weeks following cessation of a continuous 5-h exposure of rats to a 1.5-Tesla field. The heart rate and breathing rate of adult rats were not altered during, or subsequent to, application of fields up to 2.0 Tesla. The effect of animal orientation within the field was tested using juvenile rats 3-14 days old. The maximum increase in T-wave amplitude was observed when subjects were placed with the long axis of the body perpendicular to the lines of magnetic induction. (JMT)

  1. An MLP neural network for ECG noise removal based on Kalman filter.

    PubMed

    Moein, Sara

    2010-01-01

    In this paper, application of Artificial Neural Network (ANN) for electrocardiogram (ECG) signal noise removal has been investigated. First, 100 number of ECG signals are selected from Physikalisch-Technische Bundesanstalt (PTB) database and Kalman filter is applied to remove their low pass noise. Then a suitable dataset based on denoised ECG signal is configured and used to a Multilayer Perceptron (MLP) neural network to be trained. Finally, results and experiences are discussed and the effect of changing different parameters for MLP training is shown.

  2. A low-power asynchronous ECG acquisition system in CMOS technology.

    PubMed

    Hwang, Sungkil; Trakimas, Michael; Sonkusale, Sameer

    2010-01-01

    An asynchronous electrocardiogram (ECG) acquisition system is presented for wearable ambulatory monitoring. The proposed system consists of a low noise front-end amplifier (AFE) with tunable bandwidth, an asynchronous analog-to-digital converter (ADC), and digital signal processing (DSP). Data compression is achieved by the inherent signal dependent sampling rate of the asynchronous architecture. This makes the system attractive for compact wearable ECG monitoring applications. The AFE and ADC were fabricated in a 0.18 microm CMOS technology and consume a total of 79 microW. Measured results demonstrating ECG monitoring are presented. PMID:21096052

  3. Extended Kalman smoother with differential evolution technique for denoising of ECG signal.

    PubMed

    Panigrahy, D; Sahu, P K

    2016-09-01

    Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal. These parameters are used by the EKS for the development of the state equation and also for initialization of the parameters of EKS. EKS framework is used for denoising the ECG signal from the single channel. The effectiveness of proposed noise cancellation technique has been evaluated by adding white, colored Gaussian noise and real muscle artifact noise at different SNR to some visually clean ECG signals from the MIT-BIH arrhythmia database. The proposed noise cancellation technique of ECG signal shows better signal to noise ratio (SNR) improvement, lesser mean square error (MSE) and percent of distortion (PRD) compared to other well-known methods. PMID:27542170

  4. Extended Kalman smoother with differential evolution technique for denoising of ECG signal.

    PubMed

    Panigrahy, D; Sahu, P K

    2016-09-01

    Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal. These parameters are used by the EKS for the development of the state equation and also for initialization of the parameters of EKS. EKS framework is used for denoising the ECG signal from the single channel. The effectiveness of proposed noise cancellation technique has been evaluated by adding white, colored Gaussian noise and real muscle artifact noise at different SNR to some visually clean ECG signals from the MIT-BIH arrhythmia database. The proposed noise cancellation technique of ECG signal shows better signal to noise ratio (SNR) improvement, lesser mean square error (MSE) and percent of distortion (PRD) compared to other well-known methods.

  5. Live ECG readings using Google Glass in emergency situations.

    PubMed

    Schaer, Roger; Salamin, Fanny; Jimenez Del Toro, Oscar Alfonso; Atzori, Manfredo; Muller, Henning; Widmer, Antoine

    2015-01-01

    Most sudden cardiac problems require rapid treatment to preserve life. In this regard, electrocardiograms (ECG) shown on vital parameter monitoring systems help medical staff to detect problems. In some situations, such monitoring systems may display information in a less than convenient way for medical staff. For example, vital parameters are displayed on large screens outside the field of view of a surgeon during cardiac surgery. This may lead to losing time and to mistakes when problems occur during cardiac operations. In this paper we present a novel approach to display vital parameters such as the second derivative of the ECG rhythm and heart rate close to the field of view of a surgeon using Google Glass. As a preliminary assessment, we run an experimental study to verify the possibility for medical staff to identify abnormal ECG rhythms from Google Glass. This study compares 6 ECG rhythms readings from a 13.3 inch laptop screen and from the prism of Google Glass. Seven medical residents in internal medicine participated in the study. The preliminary results show that there is no difference between identifying these 6 ECG rhythms from the laptop screen versus Google Glass. Both allow close to perfect identification of the 6 common ECG rhythms. This shows the potential of connected glasses such as Google Glass to be useful in selected medical applications.

  6. Variability in surface ECG morphology: signal or noise?

    NASA Technical Reports Server (NTRS)

    Smith, J. M.; Rosenbaum, D. S.; Cohen, R. J.

    1988-01-01

    Using data collected from canine models of acute myocardial ischemia, we investigated two issues of major relevance to electrocardiographic signal averaging: ECG epoch alignment, and the spectral characteristics of the beat-to-beat variability in ECG morphology. With initial digitization rates of 1 kHz, an iterative a posteriori matched filtering alignment scheme, and linear interpolation, we demonstrated that there is sufficient information in the body surface ECG to merit alignment to a precision of 0.1 msecs. Applying this technique to align QRS complexes and atrial pacing artifacts independently, we demonstrated that the conduction delay from atrial stimulus to ventricular activation may be so variable as to preclude using atrial pacing as an alignment mechanism, and that this variability in conduction time be modulated at the frequency of respiration and at a much lower frequency (0.02-0.03Hz). Using a multidimensional spectral technique, we investigated the beat-to-beat variability in ECG morphology, demonstrating that the frequency spectrum of ECG morphological variation reveals a readily discernable modulation at the frequency of respiration. In addition, this technique detects a subtle beat-to-beat alternation in surface ECG morphology which accompanies transient coronary artery occlusion. We conclude that physiologically important information may be stored in the variability in the surface electrocardiogram, and that this information is lost by conventional averaging techniques.

  7. Chaos control applied to cardiac rhythms represented by ECG signals

    NASA Astrophysics Data System (ADS)

    Borem Ferreira, Bianca; Amorim Savi, Marcelo; Souza de Paula, Aline

    2014-10-01

    The control of irregular or chaotic heartbeats is a key issue in cardiology. In this regard, chaos control techniques represent a good alternative since they suggest treatments different from those traditionally used. This paper deals with the application of the extended time-delayed feedback control method to stabilize pathological chaotic heart rhythms. Electrocardiogram (ECG) signals are employed to represent the cardiovascular behavior. A mathematical model is employed to generate ECG signals using three modified Van der Pol oscillators connected with time delay couplings. This model provides results that qualitatively capture the general behavior of the heart. Controlled ECG signals show the ability of the strategy either to control or to suppress the chaotic heart dynamics generating less-critical behaviors.

  8. Nonstationary harmonic modeling for ECG removal in surface EMG signals.

    PubMed

    Zivanovic, Miroslav; González-Izal, Miriam

    2012-06-01

    We present a compact approach for mitigating the presence of electrocardiograms (ECG) in surface electromyographic (EMG) signals by means of time-variant harmonic modeling of the cardiac artifact. Heart rate and QRS complex variability, which often account for amplitude and frequency time variations of the ECG, are simultaneously captured by a set of third-order constant-coefficient polynomials modulating a stationary harmonic basis in the analysis window. Such a characterization allows us to significantly suppress ECG from the mixture by preserving most of the EMG signal content at low frequencies (less than 20 Hz). Moreover, the resulting model is linear in parameters and the least-squares solution to the corresponding linear system of equations efficiently provides model parameter estimates. The comparative results suggest that the proposed method outperforms two reference methods in terms of the EMG preservation at low frequencies. PMID:22453600

  9. [An improved wavelet threshold algorithm for ECG denoising].

    PubMed

    Liu, Xiuling; Qiao, Lei; Yang, Jianli; Dong, Bin; Wang, Hongrui

    2014-06-01

    Due to the characteristics and environmental factors, electrocardiogram (ECG) signals are usually interfered by noises in the course of signal acquisition, so it is crucial for ECG intelligent analysis to eliminate noises in ECG signals. On the basis of wavelet transform, threshold parameters were improved and a more appropriate threshold expression was proposed. The discrete wavelet coefficients were processed using the improved threshold parameters, the accurate wavelet coefficients without noises were gained through inverse discrete wavelet transform, and then more original signal coefficients could be preserved. MIT-BIH arrythmia database was used to validate the method. Simulation results showed that the improved method could achieve better denoising effect than the traditional ones. PMID:25219225

  10. ECG-synchronized DSA exposure control: improved cervicothoracic image quality

    SciTech Connect

    Kelly, W.M.; Gould, R.; Norman, D.; Brant-Zawadzki, M.; Cox, L.

    1984-10-01

    An electrocardiogram (ECG)-synchronized x-ray exposure sequence was used to acquire digital subtraction angiographic (DSA) images during 13 arterial injection studies of the aortic arch or carotid bifurcations. These gated images were compared with matched ungated DSA images acquired using the same technical factors, contrast material volume, and patient positioning. Subjective assessments by five experienced observers of edge definition, vessel conspicuousness, and overall diagnostic quality showed overall preference for one of the two acquisition methods in 69% of cases studied. Of these, the ECG-synchronized exposure series were rated superior in 76%. These results, as well as the relatively simple and inexpensive modifications required, suggest that routine use of ECG exposure control can facilitate improved arterial DSA evaluations of suspected cervicothoracic vascular disease.

  11. Adaptive filtering for ECG rejection from surface EMG recordings.

    PubMed

    Marque, C; Bisch, C; Dantas, R; Elayoubi, S; Brosse, V; Pérot, C

    2005-06-01

    Surface electromyograms (EMG) of back muscles are often corrupted by electrocardiogram (ECG) signals. This noise in the EMG signals does not allow to appreciate correctly the spectral content of the EMG signals and to follow its evolution during, for example, a fatigue process. Several methods have been proposed to reject the ECG noise from EMG recordings, but seldom taking into account the eventual changes in ECG characteristics during the experiment. In this paper we propose an adaptive filtering algorithm specifically developed for the rejection of the electrocardiogram corrupting surface electromyograms (SEMG). The first step of the study was to choose the ECG electrode position in order to record the ECG with a shape similar to that found in the noised SEMGs. Then, the efficiency of different algorithms were tested on 28 erector spinae SEMG recordings. The best algorithm belongs to the fast recursive least square family (FRLS). More precisely, the best results were obtained with the simplified formulation of a FRLS algorithm. As an application of the adaptive filtering, the paper compares the evolutions of spectral parameters of noised or denoised (after adaptive filtering) surface EMGs recorded on erector spinae muscles during a trunk extension. The fatigue test was analyzed on 16 EMG recordings. After adaptive filtering, mean initial values of energy and of mean power frequency (MPF) were significantly lower and higher respectively. The differences corresponded to the removal of the ECG components. Furthermore, classical fatigue criteria (increase in energy and decrease in MPF values over time during the fatigue test) were better observed on the denoised EMGs. The mean values of the slopes of the energy-time and MPF-time linear relationships differed significantly when established before and after adaptive filtering. These results account for the efficacy of the adaptive filtering method proposed here to denoise electrophysiological signals.

  12. Alterations in the rat electrocardiogram induced by stationary magnetic fields

    SciTech Connect

    Gaffey, C.T.; Tenforde, T.S.

    1981-01-01

    A field strength dependent increase in the amplitude of the T-wave signal in the rat electrocardiogram (ECG) was observed during exposure to homogeneous, stationary magnetic fields. For 24 adult Sprague-Dawley and Buffalo rats of both sexes, the T-wave amplitude was found to increase by an average of 408% in a 2.0 Tesla (1 Tesla - 10(4) Gauss) field. No significant magnetically induced changes were observed in other components of the ECG record, including the P wave and the QRS complex. The minimum field level at which augmentation of the T wave could be detected was 0.3 Tesla. The magnetically induced increase in T-wave amplitude occurred instantaneously, and was immediately reversible after exposure to fields as high as 2.0 Tesla. No abnormalities in any component of the ECG record, including the T wave, were noted during a period of 3 weeks following cessation of a continuous 5-h exposure of rats to a 1.5-Tesla field. The heart rate and breathing rate of adult rats were not altered during, or subsequent to, application of fields up to 2.0 Tesla. The effect of animal orientation within the field was tested using juvenile rats 3-14 days old. The maximum increase in T-wave amplitude was observed when subjects were placed with the long axis of the body perpendicular to the lines of magnetic induction. These experimental observations, as well as theoretical considerations, suggest that augmentation of the signal amplitude in the T-wave segment of the ECG may result from a superimposed electrical potential generated by aortic blood flow in the presence of a stationary magnetic field.

  13. Removal of baseline wandering in ECG signal by improved detrending method.

    PubMed

    Shin, Seung-Won; Kim, Kyeong-Seop; Song, Chul-Gyu; Lee, Jeong-Whan; Kim, Jeong-Hwan; Jeung, Gyeo-Wun

    2015-01-01

    The very first step to process electrocardiogram (ECG) signal is to eliminate baseline wandering interference that is usually caused by electrode-skin impedance mismatch, motion artifacts due to a patient's body moment or respiratory breathing. A new method is thus suggested to remove baseline wandering in ECG by improving the detrending method that was originally proposed for eliminating slow non-stationary trends from heart rate variability (HRV). In our proposed method, a global trend is estimated in terms of baseline wandering by merging the local trend based on an ECG segment that represents a part of the ECG signal. The experimental results show that the improved detrending method can efficiently resolve baseline wandering without distorting any morphological characteristic embedded in the ECG signal in no time delay manner.

  14. Adaptive technique for P and T wave delineation in electrocardiogram signals.

    PubMed

    Bayasi, Nourhan; Tekeste, Temesghen; Saleh, Hani; Khandoker, Ahsan; Mohammad, Baker; Ismail, Mohammed

    2014-01-01

    The T and P waves of electrocardiogram signals are excellent indicators in the analysis and interpretation of cardiac arrhythmia. As such, the need to address and develop an accurate delineation technique for the detection of these waves is necessary. In this paper, we present a novel robust and adaptive T and P wave delineation method for real-time analysis and nonstandard ECG morphologies. The proposed method is based on ECG signal filtering, value estimation of different fiducial points, applying backward and forward search windows as well as adaptive thresholds. Simulations and evaluations prove the accuracy of the proposed technique in comparison to those proposed techniques in the literature. The mean error for the T peak, T offset, P peak and P offset values are found to be 9.8, 2.3, 7.3 and 3.5 milliseconds, respectively, based on the Physionet QT database, rendering our algorithm as an excellent candidate for ECG signal analysis. PMID:25569904

  15. Robust suppression of nonstationary power-line interference in electrocardiogram signals.

    PubMed

    Li, Guojun; Zeng, Xiaopin; Zhou, Xiaona; Zhou, Yu; Liu, Guojin; Zhou, Xichuan

    2012-07-01

    It is a challenge to suppress time-varying power-line interference (PLI) with various levels in electrocardiogram (ECG) signals. Most previous attempts of tracking and suppressing the nonstationary PLI signal are based on the least-squares (LS) algorithm. This makes these methods susceptible to QRS complex in suppressing a low-level PLI signal which is frequently coupled in battery-operated ECG equipment. To address the limitation of LS-based methods, this study presents a robust PLI suppression system based on a robust extension of the Kalman filter. In addition, we used an improved version of empirical mode decomposition to further attenuate the QRS complex. Experiments show that our system could effectively suppress the PLI while preserving meaningful ECG components at various interference levels.

  16. Evaluation of agreement between temporal series obtained from electrocardiogram and pulse wave.

    NASA Astrophysics Data System (ADS)

    Leikan, GM; Rossi, E.; Sanz, MCuadra; Delisle Rodríguez, D.; Mántaras, MC; Nicolet, J.; Zapata, D.; Lapyckyj, I.; Siri, L. Nicola; Perrone, MS

    2016-04-01

    Heart rate variability allows to study the cardiovascular autonomic nervous system modulation. Usually, this signal is obtained from the electrocardiogram (ECG). A simpler method for recording the pulse wave (PW) is by means of finger photoplethysmography (PPG), which also provides information about the duration of the cardiac cycle. In this study, the correlation and agreement between the time series of the intervals between heartbeats obtained from the ECG with those obtained from the PPG, were studied. Signals analyzed were obtained from young, healthy and resting subjects. For statistical analysis, the Pearson correlation coefficient and the Bland and Altman limits of agreement were used. Results show that the time series constructed from the PW would not replace the ones obtained from ECG.

  17. Motion artifact reduction in electrocardiogram using adaptive filtering based on half cell potential monitoring.

    PubMed

    Ko, Byung-hoon; Lee, Takhyung; Choi, Changmok; Kim, Youn-ho; Park, Gunguk; Kang, KyoungHo; Bae, Sang Kon; Shin, Kunsoo

    2012-01-01

    The electrocardiogram (ECG) is the main measurement parameter for effectively diagnosing chronic disease and guiding cardio-fitness therapy. ECGs contaminated by noise or artifacts disrupt the normal functioning of the automatic analysis algorithm. The objective of this study is to evaluate a method of measuring the HCP variation in motion artifacts through direct monitoring. The proposed wearable sensing device has two channels. One channel is used to measure the ECG through a differential amplifier. The other is for monitoring motion artifacts using the modified electrode and the same differential amplifier. Noise reduction was performed using adaptive filtering, based on a reference signal highly correlated with it. Direct measurement of HCP variations can eliminate the need for additional sensors. PMID:23366209

  18. Accurate programmable electrocardiogram generator using a dynamical model implemented on a microcontroller

    NASA Astrophysics Data System (ADS)

    Chien Chang, Jia-Ren; Tai, Cheng-Chi

    2006-07-01

    This article reports on the design and development of a complete, programmable electrocardiogram (ECG) generator, which can be used for the testing, calibration and maintenance of electrocardiograph equipment. A modified mathematical model, developed from the three coupled ordinary differential equations of McSharry et al. [IEEE Trans. Biomed. Eng. 50, 289, (2003)], was used to locate precisely the positions of the onset, termination, angle, and duration of individual components in an ECG. Generator facilities are provided so the user can adjust the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave settings. The heart rate can be adjusted in increments of 1BPM (beats per minute), from 20to176BPM, while the amplitude of the ECG signal can be set from 0.1to400mV with a 0.1mV resolution. Experimental results show that the proposed concept and the resulting system are feasible.

  19. Towards the clinical use of concentric electrodes in ECG recordings: influence of ring dimensions and electrode position

    NASA Astrophysics Data System (ADS)

    Prats-Boluda, G.; Ye-Lin, Y.; Bueno-Barrachina, JM; Rodriguez de Sanabria, R.; Garcia-Casado, J.

    2016-02-01

    To overcome the limited spatial resolution of standard 12-lead ECG recordings, concentric ring electrodes (CRE) have been proposed to provide valuable data for the diagnosis of a wide range of cardiac abnormalities, including infarction and arrhythmia. Although theoretical studies indicate that the dimensions of the CRE regulate the depth of the electric dipoles sensed by these electrodes, this has not been experimentally confirmed. The aim of this work was to analyze the influence of CRE dimensions and position of a wireless multi-CRE sensor node on the cardiac signal recorded. For this, four wireless multichannel ECG recording nodes based on flexible multi-ring electrodes were placed at positions CMV1 (position comparable to V1), CMV2, CMV4R and CMV5; each node providing three bipolar concentric ECG signals (BC-ECG). Standard 12-lead ECG and 12 BC-ECG signals were recorded in 29 volunteers. The results revealed that a ring with an outer diameter of 33.5 mm achieves a balance between the ease-of-use and spatial resolution of smaller electrodes and improved detectability and higher amplitudes of signals from larger ring electrodes. Although a standard 12-lead ECG outperforms BC-ECC recordings in detectability of cardiac waves, if the relative amplitude of the wave is also considered, BC-ECG at CMV1 proved superior at picking up atrial activity. In fact, in most of the BC-ECG signals picked up at CMV1, P1 and P2 atrial activity waves were more clearly identified than in simultaneous 12-Lead ECG signals. Likewise, BC-ECG signals revealed higher spatial resolution in detecting anomalous electrical activity in local regions, such as impaired intraventricular driving, or atrioventricular blocks. Finally, the wireless multi-CRE sensor node provides enhanced comfort and handling to both patient and clinician over wired systems.

  20. Surface electrocardiogram reconstruction from intracardiac electrograms using a dynamic time delay artificial neural network

    PubMed Central

    Porée, Fabienne; Kachenoura, Amar; Carrault, Guy; Dal Molin, Renzo; Mabo, Philippe; Hernandez, Alfredo I.

    2013-01-01

    The study proposes a method to facilitate the remote follow-up of patients suffering from cardiac pathologies and treated with an implantable device, by synthesizing a 12-lead surface ECG from the intracardiac electrograms (EGM) recorded by the device. Two methods (direct and indirect), based on dynamic Time Delay artificial Neural Networks (TDNN) are proposed and compared with classical linear approaches. The direct method aims to estimate 12 different transfer functions between the EGM and each surface ECG signal. The indirect method is based on a preliminary orthogonalization phase of the available EGM and ECG signals, and the application of the TDNN between these orthogonalized signals, using only three transfer functions. These methods are evaluated on a dataset issued from 15 patients. Correlation coefficients calculated between the synthesized and the real ECG show that the proposed TDNN methods represent an efficient way to synthesize 12-lead ECG, from two or four EGM and perform better than the linear ones. We also evaluate the results as a function of the EGM configuration. Results are also supported by the comparison of extracted features and a qualitative analysis performed by a cardiologist. PMID:23086502

  1. ECG De-noising: A comparison between EEMD-BLMS and DWT-NN algorithms.

    PubMed

    Kærgaard, Kevin; Jensen, Søren Hjøllund; Puthusserypady, Sadasivan

    2015-08-01

    Electrocardiogram (ECG) is a widely used non-invasive method to study the rhythmic activity of the heart and thereby to detect the abnormalities. However, these signals are often obscured by artifacts from various sources and minimization of these artifacts are of paramount important. This paper proposes two adaptive techniques, namely the EEMD-BLMS (Ensemble Empirical Mode Decomposition in conjunction with the Block Least Mean Square algorithm) and DWT-NN (Discrete Wavelet Transform followed by Neural Network) methods in minimizing the artifacts from recorded ECG signals, and compares their performance. These methods were first compared on two types of simulated noise corrupted ECG signals: Type-I (desired ECG+noise frequencies outside the ECG frequency band) and Type-II (ECG+noise frequencies both inside and outside the ECG frequency band). Subsequently, they were tested on real ECG recordings. Results clearly show that both the methods works equally well when used on Type-I signals. However, on Type-II signals the DWT-NN performed better. In the case of real ECG data, though both methods performed similar, the DWT-NN method was a slightly better in terms of minimizing the high frequency artifacts. PMID:26737124

  2. ECG De-noising: A comparison between EEMD-BLMS and DWT-NN algorithms.

    PubMed

    Kærgaard, Kevin; Jensen, Søren Hjøllund; Puthusserypady, Sadasivan

    2015-08-01

    Electrocardiogram (ECG) is a widely used non-invasive method to study the rhythmic activity of the heart and thereby to detect the abnormalities. However, these signals are often obscured by artifacts from various sources and minimization of these artifacts are of paramount important. This paper proposes two adaptive techniques, namely the EEMD-BLMS (Ensemble Empirical Mode Decomposition in conjunction with the Block Least Mean Square algorithm) and DWT-NN (Discrete Wavelet Transform followed by Neural Network) methods in minimizing the artifacts from recorded ECG signals, and compares their performance. These methods were first compared on two types of simulated noise corrupted ECG signals: Type-I (desired ECG+noise frequencies outside the ECG frequency band) and Type-II (ECG+noise frequencies both inside and outside the ECG frequency band). Subsequently, they were tested on real ECG recordings. Results clearly show that both the methods works equally well when used on Type-I signals. However, on Type-II signals the DWT-NN performed better. In the case of real ECG data, though both methods performed similar, the DWT-NN method was a slightly better in terms of minimizing the high frequency artifacts.

  3. Clinical evaluation of a wireless ECG sensor system for arrhythmia diagnostic purposes.

    PubMed

    Fensli, Rune; Gundersen, Torstein; Snaprud, Tormod; Hejlesen, Ole

    2013-06-01

    In a clinical study, a novel wireless electrocardiogram (ECG) recorder has been evaluated with regard to its ability to perform arrhythmia diagnostics. As the ECG recorder will detect a "non-standard" ECG signal, it has been necessary to compare those signals to "standard" ECG recording signals in order to evaluate the arrhythmia detection ability of the new system. Simultaneous recording of ECG signals from both the new wireless ECG recorder and a conventional Holter recorder was compared by two independent cardiology specialists with regard to signal quality for performing arrhythmia diagnosis. In addition, calculated R-R intervals from the two systems were correlated. A total number of 16 patients participated in the study. It can be considered that recorded ECG signals obtained from the wireless ECG system had an acceptable quality for arrhythmia diagnosis. Some of the patients used the wireless sensor while doing physical sport activities, and the quality of the recorded ECG signals made it possible to perform arrhythmia diagnostics even under such conditions. Consequently, this makes possible improvements in correlating arrhythmias to physical activities.

  4. [Removal Algorithm of Power Line Interference in Electrocardiogram Based on Morphological Component Analysis and Ensemble Empirical Mode Decomposition].

    PubMed

    Zhao, Wei; Xiao, Shixiao; Zhang, Baocan; Huang, Xiaojing; You, Rongyi

    2015-12-01

    Electrocardiogram (ECG) signals are susceptible to be disturbed by 50 Hz power line interference (PLI) in the process of acquisition and conversion. This paper, therefore, proposes a novel PLI removal algorithm based on morphological component analysis (MCA) and ensemble empirical mode decomposition (EEMD). Firstly, according to the morphological differences in ECG waveform characteristics, the noisy ECG signal was decomposed into the mutated component, the smooth component and the residual component by MCA. Secondly, intrinsic mode functions (IMF) of PLI was filtered. The noise suppression rate (NSR) and the signal distortion ratio (SDR) were used to evaluate the effect of de-noising algorithm. Finally, the ECG signals were re-constructed. Based on the experimental comparison, it was concluded that the proposed algorithm had better filtering functions than the improved Levkov algorithm, because it could not only effectively filter the PLI, but also have smaller SDR value. PMID:27079083

  5. Human Authentication Based on ECG Waves Using Radon Transform

    NASA Astrophysics Data System (ADS)

    Hegde, Chetana; Prabhu, H. Rahul; Sagar, D. S.; Shenoy, P. Deepa; Venugopal, K. R.; Patnaik, L. M.

    Automated security is one of the major concerns of modern times. Secure and reliable authentication systems are in great demand. A biometric trait like electrocardiogram (ECG) of a person is unique and secure. In this paper, we propose a human authentication system based on ECG waves considering a plotted ECG wave signal as an image. The Radon Transform is applied on the preprocessed ECG image to get a radon image consisting of projections for θ varying from 0 o to 180 o . The pairwise distance between the columns of Radon image is computed to get a feature vector. Correlation Coefficient between feature vector stored in the database and that of input image is computed to check the authenticity of a person. Then the confusion matrix is generated to find False Acceptance Ratio (FAR) and False Rejection Ratio (FRR). This methodology of authentication is tested on ECG wave data set of 105 individuals taken from Physionet QT Database. The proposed authentication system is found to have FAR of about 3.19% and FRR of about 0.128%. The overall accuracy of the system is found to be 99.85%.

  6. Fast multi-scale feature fusion for ECG heartbeat classification

    NASA Astrophysics Data System (ADS)

    Ai, Danni; Yang, Jian; Wang, Zeyu; Fan, Jingfan; Ai, Changbin; Wang, Yongtian

    2015-12-01

    Electrocardiogram (ECG) is conducted to monitor the electrical activity of the heart by presenting small amplitude and duration signals; as a result, hidden information present in ECG data is difficult to determine. However, this concealed information can be used to detect abnormalities. In our study, a fast feature-fusion method of ECG heartbeat classification based on multi-linear subspace learning is proposed. The method consists of four stages. First, baseline and high frequencies are removed to segment heartbeat. Second, as an extension of wavelets, wavelet-packet decomposition is conducted to extract features. With wavelet-packet decomposition, good time and frequency resolutions can be provided simultaneously. Third, decomposed confidences are arranged as a two-way tensor, in which feature fusion is directly implemented with generalized N dimensional ICA (GND-ICA). In this method, co-relationship among different data information is considered, and disadvantages of dimensionality are prevented; this method can also be used to reduce computing compared with linear subspace-learning methods (PCA). Finally, support vector machine (SVM) is considered as a classifier in heartbeat classification. In this study, ECG records are obtained from the MIT-BIT arrhythmia database. Four main heartbeat classes are used to examine the proposed algorithm. Based on the results of five measurements, sensitivity, positive predictivity, accuracy, average accuracy, and t-test, our conclusion is that a GND-ICA-based strategy can be used to provide enhanced ECG heartbeat classification. Furthermore, large redundant features are eliminated, and classification time is reduced.

  7. Exploiting prior knowledge in compressed sensing wireless ECG systems.

    PubMed

    Polanía, Luisa F; Carrillo, Rafael E; Blanco-Velasco, Manuel; Barner, Kenneth E

    2015-03-01

    Recent results in telecardiology show that compressed sensing (CS) is a promising tool to lower energy consumption in wireless body area networks for electrocardiogram (ECG) monitoring. However, the performance of current CS-based algorithms, in terms of compression rate and reconstruction quality of the ECG, still falls short of the performance attained by state-of-the-art wavelet-based algorithms. In this paper, we propose to exploit the structure of the wavelet representation of the ECG signal to boost the performance of CS-based methods for compression and reconstruction of ECG signals. More precisely, we incorporate prior information about the wavelet dependencies across scales into the reconstruction algorithms and exploit the high fraction of common support of the wavelet coefficients of consecutive ECG segments. Experimental results utilizing the MIT-BIH Arrhythmia Database show that significant performance gains, in terms of compression rate and reconstruction quality, can be obtained by the proposed algorithms compared to current CS-based methods. PMID:24846672

  8. A system for intelligent home care ECG upload and priorisation.

    PubMed

    D'Angelo, Lorenzo T; Tarita, Eugeniu; Zywietz, Tosja K; Lueth, Tim C

    2010-01-01

    In this contribution, a system for internet based, automated home care ECG upload and priorisation is presented for the first time. It unifies the advantages of existing telemonitoring ECG systems adding functionalities such as automated priorisation and usability for home care. Chronic cardiac diseases are a big group in the geriatric field. Most of them can be easily diagnosed with help of an electrocardiogram. A frequent or long-term ECG analysis allows early diagnosis of e.g. a cardiac infarction. Nevertheless, patients often aren't willing to visit a doctor for prophylactic purposes. Possible solutions of this problem are home care devices, which are used to investigate patients at home without the presence of a doctor on site. As the diffusion of such systems leads to a huge amount of data which has to be managed and evaluated, the presented approach focuses on an easy to use software for ECG upload from home, a web based management application and an algorithm for ECG preanalysis and priorisation.

  9. Noninvasive extraction of fetal electrocardiogram based on Support Vector Machine

    NASA Astrophysics Data System (ADS)

    Fu, Yumei; Xiang, Shihan; Chen, Tianyi; Zhou, Ping; Huang, Weiyan

    2015-10-01

    The fetal electrocardiogram (FECG) signal has important clinical value for diagnosing the fetal heart diseases and choosing suitable therapeutics schemes to doctors. So, the noninvasive extraction of FECG from electrocardiogram (ECG) signals becomes a hot research point. A new method, the Support Vector Machine (SVM) is utilized for the extraction of FECG with limited size of data. Firstly, the theory of the SVM and the principle of the extraction based on the SVM are studied. Secondly, the transformation of maternal electrocardiogram (MECG) component in abdominal composite signal is verified to be nonlinear and fitted with the SVM. Then, the SVM is trained, and the training results are compared with the real data to ensure the effect of the training. Meanwhile, the parameters of the SVM are optimized to achieve the best performance so that the learning machine can be utilized to fit the unknown samples. Finally, the FECG is extracted by removing the optimal estimation of MECG component from the abdominal composite signal. In order to evaluate the performance of FECG extraction based on the SVM, the Signal-to-Noise Ratio (SNR) and the visual test are used. The experimental results show that the FECG with good quality can be extracted, its SNR ratio is significantly increased as high as 9.2349 dB and the time cost is significantly decreased as short as 0.802 seconds. Compared with the traditional method, the noninvasive extraction method based on the SVM has a simple realization, the shorter treatment time and the better extraction quality under the same conditions.

  10. ECG manifestations of left ventricular electrical remodeling.

    PubMed

    Estes, E Harvey

    2012-01-01

    Research and thinking about the electrocardiographic manifestations of left ventricular hypertrophy has been constrained by a limited conceptual model of the process: heart disease produces chamber enlargement (increased mass), which in turn produces an altered electrocardiogram. The process is much more complex than can be represented in this simple model. A more robust and intricate model is proposed, in which heart (and vascular) disease causes structural changes, electrical changes, biochemical changes, and others, all of which interact to produce electrical remodeling of ventricular myocardium. This electrical remodeling results in a variety of ECG changes. All of these changes interact, leading to an altered clinical course, and to premature death. It is suggested that research, based on this model, can provide new clues to the processes involved, and improve the prediction of clinical outcomes. New directions in research, in recording equipment, and in organizational activities are suggested to test this new model, and to improve the usefulness of the electrocardiogram as a research and diagnostic tool.

  11. A proposal for monitoring patients with heart failure via "smart phone technology"-based electrocardiograms.

    PubMed

    Madias, John E

    2016-01-01

    The ubiquitous smart phone/device technology (SPT) has enabled the safe acquisition/transmission (A/T) of clinical and laboratory patient data, including the electrocardiogram (ECG). SPT-based A/T of the ECG has been found useful in the detection of atrial fibrillation, in monitoring of the QTc interval, in patients undergoing antiarrhythmic drug loading, and in management of patients with acute ST-elevation myocardial infarction. Previous work has shown a relationship between changes in the voltage of the ECG QRS complexes, with perturbations in the edematous state of various etiologies, including heart failure (HF). It is proposed herein to employ serially SPT-based 3-lead ECG A/T for the monitoring and management of patients with HF in their ambient environment. The proposed method will enable patients with HF to acquire/transmit their 3-lead ECG to the caring HF team, using only their smart phone and it takes into consideration the advanced degrees of physical incapacitation and age-related infirmities inherent to the HF population. PMID:27334627

  12. Temporal abstraction and inductive logic programming for arrhythmia recognition from electrocardiograms.

    PubMed

    Carrault, G; Cordier, M-O; Quiniou, R; Wang, F

    2003-07-01

    This paper proposes a novel approach to cardiac arrhythmia recognition from electrocardiograms (ECGs). ECGs record the electrical activity of the heart and are used to diagnose many heart disorders. The numerical ECG is first temporally abstracted into series of time-stamped events. Temporal abstraction makes use of artificial neural networks to extract interesting waves and their features from the input signals. A temporal reasoner called a chronicle recogniser processes such series in order to discover temporal patterns called chronicles which can be related to cardiac arrhythmias. Generally, it is difficult to elicit an accurate set of chronicles from a doctor. Thus, we propose to learn automatically from symbolic ECG examples the chronicles discriminating the arrhythmias belonging to some specific subset. Since temporal relationships are of major importance, inductive logic programming (ILP) is the tool of choice as it enables first-order relational learning. The approach has been evaluated on real ECGs taken from the MIT-BIH database. The performance of the different modules as well as the efficiency of the whole system is presented. The results are rather good and demonstrate that integrating numerical techniques for low level perception and symbolic techniques for high level classification is very valuable.

  13. Can myocardial ischemia be recognized by the exercise electrocardiogram in coronary disease patients with abnormal resting Q waves

    SciTech Connect

    Ahnve, S.; Savvides, M.; Abouantoun, S.; Atwood, J.E.; Froelicher, V.

    1986-05-01

    This study was performed in order to determine whether exercise-induced myocardial ischemia demonstrated by thallium-201 imaging could be detected by ST segment shifts in patients with abnormal Q waves at rest. Fifty-four patients with coronary artery disease and exercise-induced thallium-201 defects were compared to 22 patients with similar Q wave patterns but without thallium-201 exercise defects and to 14 normal subjects. Exercise data were analyzed visually in the 12-lead ECG and for spatial ST vector shifts. Both ST segment depression observed on the 12-lead ECG and spatial criteria were reasonably sensitive and specific for ischemia when the resting ECG showed no Q waves or inferior Q waves (range 69% to 93%). However, when anterior Q waves were present, ST segment shifts could not distinguish patients with ischemia from those with normal perfusion as determined by thallium imaging.

  14. Electrocardiograms Corresponding to the Development of Myocardial Infarction in Anesthetized WHHLMI Rabbits (Oryctolagus cuniculus), an Animal Model for Familial Hypercholesterolemia

    PubMed Central

    Kobayashi, Tsutomu; Ito, Takashi; Yamada, Satoshi; Kuniyoshi, Nobue; Shiomi, Masashi

    2012-01-01

    The aim of this study was to determine whether features indicative of myocardial ischemia occur in the electrocardiograms (ECG) in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for human familial hypercholesterolemia. ECG were recorded in 110 anesthetized WHHLMI rabbits (age, 10 to 39 mo) by using unipolar and bipolar limb leads with or without chest leads. We noted the following electrocardiographic changes: T wave inversion (37.4%), ST segment depression (31.8%), deep Q wave (16.3%), reduced R wave amplitude (7.3%), ST segment elevation (2.7%), and high T wave (1.8%). These ECG changes resembled those in human patients with coronary heart disease. Histopathologic examination revealed that the left ventricular wall showed acute myocardial lesions, including loss of cross-striations, vacuolar degeneration, coagulation necrosis of cardiac myocytes, and edema between myofibrils, in addition to chronic myocardial lesions such as myocardial fibrosis. The coronary arteries that caused these ECG changes were severely stenosed due to atherosclerotic lesions. Ischemic ECG changes corresponded to the locations of the myocardial lesions. Normal ECG waveforms were similar between WHHLMI rabbits and humans, in contrast to the large differences between rabbits and mice or rats. In conclusion, ischemic ECG changes in WHHLMI rabbits reflect the location of myocardial lesions, making this model useful for studying coronary heart disease. PMID:23114045

  15. Electrocardiograms corresponding to the development of myocardial infarction in anesthetized WHHLMI rabbits (Oryctolagus cuniculus), an animal model for familial hypercholesterolemia.

    PubMed

    Kobayashi, Tsutomu; Ito, Takashi; Yamada, Satoshi; Kuniyoshi, Nobue; Shiomi, Masashi

    2012-10-01

    The aim of this study was to determine whether features indicative of myocardial ischemia occur in the electrocardiograms (ECG) in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for human familial hypercholesterolemia. ECG were recorded in 110 anesthetized WHHLMI rabbits (age, 10 to 39 mo) by using unipolar and bipolar limb leads with or without chest leads. We noted the following electrocardiographic changes: T wave inversion (37.4%), ST segment depression (31.8%), deep Q wave (16.3%), reduced R wave amplitude (7.3%), ST segment elevation (2.7%), and high T wave (1.8%). These ECG changes resembled those in human patients with coronary heart disease. Histopathologic examination revealed that the left ventricular wall showed acute myocardial lesions, including loss of cross-striations, vacuolar degeneration, coagulation necrosis of cardiac myocytes, and edema between myofibrils, in addition to chronic myocardial lesions such as myocardial fibrosis. The coronary arteries that caused these ECG changes were severely stenosed due to atherosclerotic lesions. Ischemic ECG changes corresponded to the locations of the myocardial lesions. Normal ECG waveforms were similar between WHHLMI rabbits and humans, in contrast to the large differences between rabbits and mice or rats. In conclusion, ischemic ECG changes in WHHLMI rabbits reflect the location of myocardial lesions, making this model useful for studying coronary heart disease. PMID:23114045

  16. An Adaptive Framework for Real-Time ECG Transmission in Mobile Environments

    PubMed Central

    2014-01-01

    Wireless electrocardiogram (ECG) monitoring involves the measurement of ECG signals and their timely transmission over wireless networks to remote healthcare professionals. However, fluctuations in wireless channel conditions pose quality-of-service challenges for real-time ECG monitoring services in a mobile environment. We present an adaptive framework for layered coding and transmission of ECG data that can cope with a time-varying wireless channel. The ECG is segmented into layers with differing importance with respect to the quality of the reconstructed signal. According to this observation, we have devised a simple and efficient real-time scheduling algorithm based on the earliest deadline first (EDF) policy, which decides the order of transmitting or retransmitting packets that contain ECG data at any given time for the delivery of scalable ECG data over a lossy channel. The algorithm takes into account the differing priorities of packets in each layer, which prevents the perceived quality of the reconstructed ECG signal from degrading abruptly as channel conditions worsen, while using the available bandwidth efficiently. Extensive simulations demonstrate this improvement in perceived quality. PMID:25097886

  17. Development of Novel Non-Contact Electrodes for Mobile Electrocardiogram Monitoring System

    PubMed Central

    Chou, Willy; Wang, Hsing-Yu; Huang, Yan-Jun; Pan, Jeng-Shyang

    2013-01-01

    Real-time monitoring of cardiac health is helpful for patients with cardiovascular disease. Many telemedicine systems based on ubiquitous computing and communication techniques have been proposed for monitoring the user's electrocardiogram (ECG) anywhere and anytime. Usually, wet electrodes are used in these telemedicine systems. However, wet electrodes require conduction gels and skin preparation that can be inconvenient and uncomfortable for users. In order to overcome this issue, a new non-contact electrode circuit was proposed and applied in developing a mobile electrocardiogram monitoring system. The proposed non-contact electrode can measure bio-potentials across thin clothing, allowing it to be embedded in a user's normal clothing to monitor ECG in daily life. We attempted to simplify the design of these non-contact electrodes to reduce power consumption while continuing to provide good signal quality. The electrical specifications and the performance of monitoring arrhythmia in clinical settings were also validated to investigate the reliability of the proposed design. Experimental results show that the proposed non-contact electrode provides good signal quality for measuring ECG across thin clothes. PMID:27170853

  18. Wavelet-based unsupervised learning method for electrocardiogram suppression in surface electromyograms.

    PubMed

    Niegowski, Maciej; Zivanovic, Miroslav

    2016-03-01

    We present a novel approach aimed at removing electrocardiogram (ECG) perturbation from single-channel surface electromyogram (EMG) recordings by means of unsupervised learning of wavelet-based intensity images. The general idea is to combine the suitability of certain wavelet decomposition bases which provide sparse electrocardiogram time-frequency representations, with the capacity of non-negative matrix factorization (NMF) for extracting patterns from images. In order to overcome convergence problems which often arise in NMF-related applications, we design a novel robust initialization strategy which ensures proper signal decomposition in a wide range of ECG contamination levels. Moreover, the method can be readily used because no a priori knowledge or parameter adjustment is needed. The proposed method was evaluated on real surface EMG signals against two state-of-the-art unsupervised learning algorithms and a singular spectrum analysis based method. The results, expressed in terms of high-to-low energy ratio, normalized median frequency, spectral power difference and normalized average rectified value, suggest that the proposed method enables better ECG-EMG separation quality than the reference methods. PMID:26774422

  19. Classification of the electrocardiogram signals using supervised classifiers and efficient features.

    PubMed

    Zadeh, Ataollah Ebrahim; Khazaee, Ali; Ranaee, Vahid

    2010-08-01

    Automatic classification of electrocardiogram (ECG) signals is vital for clinical diagnosis of heart disease. This paper investigates the design of an efficient system for recognition of the premature ventricular contraction from the normal beats and other heart diseases. This system includes three main modules: denoising module, feature extraction module and classifier module. In the denoising module, it is proposed the stationary wavelet transform for noise reduction of the electrocardiogram signals. In the feature extraction module a proper combination of the morphological-based features and timing interval-based features are proposed. As the classifier, several supervised classifiers are investigated; they are: a number of multi-layer perceptron neural networks with different number of layers and training algorithms, support vector machines with different kernel types, radial basis function and probabilistic neural networks. Also, for comparison the proposed features, we have considered the wavelet-based features. It has done comprehensive simulations in order to achieve a high efficient system for ECG beat classification from 12 files obtained from the MIT-BIH arrhythmia database. Simulation results show that best results are achieved about 97.14% for classification of ECG beats.

  20. A three-lead, programmable, and microcontroller-based electrocardiogram generator with frequency domain characteristics of heart rate variability

    NASA Astrophysics Data System (ADS)

    Wei, Ying-Chieh; Wei, Ying-Yu; Chang, Kai-Hsiung; Young, Ming-Shing

    2012-04-01

    The objective of this study is to design and develop a programmable electrocardiogram (ECG) generator with frequency domain characteristics of heart rate variability (HRV) which can be used to test the efficiency of ECG algorithms and to calibrate and maintain ECG equipment. We simplified and modified the three coupled ordinary differential equations in McSharry's model to a single differential equation to obtain the ECG signal. This system not only allows the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters to be adjusted, but can also be used to adjust the very low frequency, low frequency, and high frequency components of HRV frequency domain characteristics. The system can be tuned to function with HRV or not. When the HRV function is on, the average heart rate can be set to a value ranging from 20 to 122 beats per minute (BPM) with an adjustable variation of 1 BPM. When the HRV function is off, the heart rate can be set to a value ranging from 20 to 139 BPM with an adjustable variation of 1 BPM. The amplitude of the ECG signal can be set from 0.0 to 330 mV at a resolution of 0.005 mV. These parameters can be adjusted either via input through a keyboard or through a graphical user interface (GUI) control panel that was developed using LABVIEW. The GUI control panel depicts a preview of the ECG signal such that the user can adjust the parameters to establish a desired ECG morphology. A complete set of parameters can be stored in the flash memory of the system via a USB 2.0 interface. Our system can generate three different types of synthetic ECG signals for testing the efficiency of an ECG algorithm or calibrating and maintaining ECG equipment.

  1. Patient-specific ECG beat classification technique.

    PubMed

    Das, Manab K; Ari, Samit

    2014-09-01

    Electrocardiogram (ECG) beat classification plays an important role in the timely diagnosis of the critical heart condition. An automated diagnostic system is proposed to classify five types of ECG classes, namely normal (N), ventricular ectopic beat (V), supra ventricular ectopic beat (S), fusion (F) and unknown (Q) as recommended by the Association for the Advancement of Medical Instrumentation (AAMI). The proposed method integrates the Stockwell transform (ST), a bacteria foraging optimisation (BFO) algorithm and a least mean square (LMS)-based multiclass support vector machine (SVM) classifier. The ST is utilised to extract the important morphological features which are concatenated with four timing features. The resultant combined feature vector is optimised by removing the redundant and irrelevant features using the BFO algorithm. The optimised feature vector is applied to the LMS-based multiclass SVM classifier for automated diagnosis. In the proposed technique, the LMS algorithm is used to modify the Lagrange multiplier, which in turn modifies the weight vector to minimise the classification error. The updated weights are used during the testing phase to classify ECG beats. The classification performances are evaluated using the MIT-BIH arrhythmia database. Average accuracy and sensitivity performances of the proposed system for V detection are 98.6% and 91.7%, respectively, and for S detections, 98.2% and 74.7%, respectively over the entire database. To generalise the capability, the classification performance is also evaluated using the St. Petersburg Institute of Cardiological Technics (INCART) database. The proposed technique performs better than other reported heartbeat techniques, with results suggesting better generalisation capability.

  2. Removing movement artifacts from equine ECG recordings acquired with textile electrodes.

    PubMed

    Lanata, Antonio; Guidi, Andrea; Baragli, Paolo; Paradiso, Rita; Valenza, Gaetano; Scilingo, Enzo Pasquale

    2015-08-01

    This study reports on the implementation of a novel system to detect and reduce movement artifact (MA) contribution in electrocardiogram (ECG) recordings acquired from horses in free movement conditions. The system comprises both integrated textile electrodes for ECG acquisition and one triaxial accelerometer for movement monitoring. Here, ECG and physical activity are continuously acquired from seven horses through the wearable system and a model that integrates cardiovascular and movement information to estimate the MA contribution is implemented. Moreover, in this study we propose a new algorithm where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG recodigns. Achieved results showed a reduction of MA percentage greater than 40% between before- and after- the application of the proposed algorithm to seven hours of recordings. PMID:26736667

  3. A Primary Study of Indirect ECG Monitor Embedded in a Bed for Home Health Care

    NASA Astrophysics Data System (ADS)

    Ueno, Akinori; Shiogai, Yuuki; Ishiyama, Yoji

    A system for monitoring electrocardiogram (ECG) through clothes inserted between the measuring electrodes and the body surface of a subject when lying on a mattress has been proposed. The principle of the system is based on capacitive coupling involving the electrode, the clothes, and the skin. Validation of the system revealed the following: (1) In spite of the gain attenuation in the pass band of the system, distortion of the detected signal was subtle even when clothes thicker than 1mm were inserted, (2) The system was able to yield a stable ECG from a subject particularly during sound sleep, (3) The system succeeded in detecting ECG after changing the posture into any of supine, right lateral, or left lateral positions by adopting a newly devised electrode configuration. Therefore, the proposed system appears promising for application to bedding as a non-invasive and awareness-free system for ECG monitoring during sleep.

  4. A Human ECG Identification System Based on Ensemble Empirical Mode Decomposition

    PubMed Central

    Zhao, Zhidong; Yang, Lei; Chen, Diandian; Luo, Yi

    2013-01-01

    In this paper, a human electrocardiogram (ECG) identification system based on ensemble empirical mode decomposition (EEMD) is designed. A robust preprocessing method comprising noise elimination, heartbeat normalization and quality measurement is proposed to eliminate the effects of noise and heart rate variability. The system is independent of the heart rate. The ECG signal is decomposed into a number of intrinsic mode functions (IMFs) and Welch spectral analysis is used to extract the significant heartbeat signal features. Principal component analysis is used reduce the dimensionality of the feature space, and the K-nearest neighbors (K-NN) method is applied as the classifier tool. The proposed human ECG identification system was tested on standard MIT-BIH ECG databases: the ST change database, the long-term ST database, and the PTB database. The system achieved an identification accuracy of 95% for 90 subjects, demonstrating the effectiveness of the proposed method in terms of accuracy and robustness. PMID:23698274

  5. Removing movement artifacts from equine ECG recordings acquired with textile electrodes.

    PubMed

    Lanata, Antonio; Guidi, Andrea; Baragli, Paolo; Paradiso, Rita; Valenza, Gaetano; Scilingo, Enzo Pasquale

    2015-01-01

    This study reports on the implementation of a novel system to detect and reduce movement artifact (MA) contribution in electrocardiogram (ECG) recordings acquired from horses in free movement conditions. The system comprises both integrated textile electrodes for ECG acquisition and one triaxial accelerometer for movement monitoring. Here, ECG and physical activity are continuously acquired from seven horses through the wearable system and a model that integrates cardiovascular and movement information to estimate the MA contribution is implemented. Moreover, in this study we propose a new algorithm where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG recodigns. Achieved results showed a reduction of MA percentage greater than 40% between before- and after- the application of the proposed algorithm to seven hours of recordings.

  6. ECG manifestations of multiple electrolyte imbalance: peaked T wave to P wave ("tee-pee sign").

    PubMed

    Johri, Amer M; Baranchuk, Adrian; Simpson, Christopher S; Abdollah, Hoshiar; Redfearn, Damian P

    2009-04-01

    The surface electrocardiogram (ECG) is a useful instrument in the detection of metabolic disturbances. The accurate characterization of these disturbances, however, may be considerably more difficult when more than one metabolic abnormality is present in the same individual. While "classic" ECG presentations of common electrolyte disturbances are well described, multiple electrolyte disturbances occurring simultaneously may generate ECG abnormalities that are not as readily recognizable. We report a case of hyperkalemia, with concurrent hypocalcemia and hypomagnesemia resulting in (1) peaking of the T wave, (2) a prominent U wave, and (3) prolongation of the descending limb of the T wave such that it overlapped with the next P wave. In this particular ECG from a patient with combined electrolyte imbalance, we have dubbed the unusual appearance of the segment between the peak of the T wave to the next P wave as the "tee-pee" sign. PMID:19419407

  7. Quantification of motion artifact in ECG electrode design.

    PubMed

    Kearney, Kenneth; Thomas, Chris; McAdams, Eric

    2007-01-01

    We have developed a more accurate and reproducible method of quantifying motion artifact in ECG (electrocardiogram) electrodes to assist in electrode assessment and design. It uses an algorithm developed by Sensor Technology & Devices Ltd. to reliably overcome the variation in results due to differing skin types and other causes of spurious readings such as reproducibility of movements used. The method combines a clear, concise experimental protocol with a software package and DSP algorithm to produce a transferable result for one pair of electrodes that can be used for comparison.

  8. The study and design of a wireless ECG monitoring system.

    PubMed

    Yang, Hongli; Chai, Jihong

    2012-01-01

    This paper describes a research project on wireless electrocardiogram (ECG) monitoring systems. A detection and measurement processor designed by a MSP430 microcontroller accomplishes the analog-to-digital conversion, digital filtering, QRS wave detection, and heart rate calculation. The data of detection can be sent to the central controller and personal computer (PC) by wireless on-chip MG2455 through a ZigBee network. This design can be used widely in home healthcare, community healthcare, and sports training, as well as in healthcare facilities, due to its characteristics of low power consumption, small size, and reliability. PMID:23039742

  9. MicroECG: An Integrated Platform for the Cardiac Arrythmia Detection and Characterization

    NASA Astrophysics Data System (ADS)

    Nascimento, Bruno; Batista, Arnaldo; Alves, Luis Brandão; Ortigueira, Manuel; Rato, Raul

    A software tool for the analysis of the High-Resolution Electrocardiogram (HR-ECG) for Arrhythmia detection is introduced. New algorithms based on Wavelet analysis are presented and compared with the classic Simson protocol over the P and QRS segments of the Electrocardiogram (EEG). A novel procedure based on a two step wavelet analysis and synthesis is performed in order to obtain a frequency description of the P, T or QRS segments. This frequency "signature" is useful for the detection of otherwise asymptomatic Arrhythmia patients. The tool has been developed in Matlab, and deployed for a standalone C application.

  10. Combining Wavelet Transform and Hidden Markov Models for ECG Segmentation

    NASA Astrophysics Data System (ADS)

    Andreão, Rodrigo Varejão; Boudy, Jérôme

    2006-12-01

    This work aims at providing new insights on the electrocardiogram (ECG) segmentation problem using wavelets. The wavelet transform has been originally combined with a hidden Markov models (HMMs) framework in order to carry out beat segmentation and classification. A group of five continuous wavelet functions commonly used in ECG analysis has been implemented and compared using the same framework. All experiments were realized on the QT database, which is composed of a representative number of ambulatory recordings of several individuals and is supplied with manual labels made by a physician. Our main contribution relies on the consistent set of experiments performed. Moreover, the results obtained in terms of beat segmentation and premature ventricular beat (PVC) detection are comparable to others works reported in the literature, independently of the type of the wavelet. Finally, through an original concept of combining two wavelet functions in the segmentation stage, we achieve our best performances.

  11. Using ordinal partition transition networks to analyze ECG data.

    PubMed

    Kulp, Christopher W; Chobot, Jeremy M; Freitas, Helena R; Sprechini, Gene D

    2016-07-01

    Electrocardiogram (ECG) data from patients with a variety of heart conditions are studied using ordinal pattern partition networks. The ordinal pattern partition networks are formed from the ECG time series by symbolizing the data into ordinal patterns. The ordinal patterns form the nodes of the network and edges are defined through the time ordering of the ordinal patterns in the symbolized time series. A network measure, called the mean degree, is computed from each time series-generated network. In addition, the entropy and number of non-occurring ordinal patterns (NFP) is computed for each series. The distribution of mean degrees, entropies, and NFPs for each heart condition studied is compared. A statistically significant difference between healthy patients and several groups of unhealthy patients with varying heart conditions is found for the distributions of the mean degrees, unlike for any of the distributions of the entropies or NFPs.

  12. Using ordinal partition transition networks to analyze ECG data

    NASA Astrophysics Data System (ADS)

    Kulp, Christopher W.; Chobot, Jeremy M.; Freitas, Helena R.; Sprechini, Gene D.

    2016-07-01

    Electrocardiogram (ECG) data from patients with a variety of heart conditions are studied using ordinal pattern partition networks. The ordinal pattern partition networks are formed from the ECG time series by symbolizing the data into ordinal patterns. The ordinal patterns form the nodes of the network and edges are defined through the time ordering of the ordinal patterns in the symbolized time series. A network measure, called the mean degree, is computed from each time series-generated network. In addition, the entropy and number of non-occurring ordinal patterns (NFP) is computed for each series. The distribution of mean degrees, entropies, and NFPs for each heart condition studied is compared. A statistically significant difference between healthy patients and several groups of unhealthy patients with varying heart conditions is found for the distributions of the mean degrees, unlike for any of the distributions of the entropies or NFPs.

  13. Diverse and composite features for ECG signals processing.

    PubMed

    Ubeyli, Elif Derya

    2008-01-01

    The automated diagnostic systems employing diverse and composite features for electrocardiogram (ECG) signals were analyzed and their accuracies were determined. Because of the importance of making the right decision, classification procedures classifying the ECG signals with high accuracy were investigated. The classification accuracies of multilayer perceptron neural network (MLPNN), recurrent neural network (RNN), and mixture of experts (ME) trained on composite features and modified mixture of experts (MME) trained on diverse features were compared. The inputs of these automated diagnostic systems were composed of diverse or composite features (wavelet coefficients and power levels of the power spectral density estimates obtained by the eigenvector methods) and were chosen according to the network structures. The conclusions of this study demonstrated that the MME trained on diverse features achieved accuracy rates which were higher than that of the other automated diagnostic systems trained on composite features. PMID:18408257

  14. A compact electric potential sensor array for the acquisition and reconstruction of the 7-lead electrocardiogram without electrical charge contact with the skin.

    PubMed

    Harland, C J; Clark, T D; Peters, N S; Everitt, M J; Stiffell, P B

    2005-12-01

    Conventional electrocardiogram (ECG) systems make use of separate electrical connections to the arms and legs. These use a 'long baseline' for the voltage reference potential which in the case of precordial ECG leads is provided using a Wilson central terminal (WCT) wiring configuration. The aims of this project were (a) to construct compact, non-invasive surface ECG sensor arrays which would operate without the need for a WCT reference, (b) to obtain high quality precordial ECGs showing fine differences in ECG detail between small adjacent areas of the chest and (c) to reconstruct, from a compact array of four sensors, ECGs which closely match to the conventional 7-lead ECG system, but without the need for multiple wires and long baselines. In this paper, we describe two sensor array configurations which have been constructed using electric potential sensors (EPSs). We show high quality precordial ECGs obtained from small areas of the surface of the chest and show the different angular vectors (leads) in the frontal cardiac plane constructed using signals from the array elements. We suggest that these ECG arrays, which are simple to apply, should prove to be a valuable tool in providing useful information about the state of the heart. PMID:16311443

  15. ECG-cryptography and authentication in body area networks.

    PubMed

    Zhang, Zhaoyang; Wang, Honggang; Vasilakos, Athanasios V; Fang, Hua

    2012-11-01

    Wireless body area networks (BANs) have drawn much attention from research community and industry in recent years. Multimedia healthcare services provided by BANs can be available to anyone, anywhere, and anytime seamlessly. A critical issue in BANs is how to preserve the integrity and privacy of a person's medical data over wireless environments in a resource efficient manner. This paper presents a novel key agreement scheme that allows neighboring nodes in BANs to share a common key generated by electrocardiogram (ECG) signals. The improved Jules Sudan (IJS) algorithm is proposed to set up the key agreement for the message authentication. The proposed ECG-IJS key agreement can secure data communications over BANs in a plug-n-play manner without any key distribution overheads. Both the simulation and experimental results are presented, which demonstrate that the proposed ECG-IJS scheme can achieve better security performance in terms of serval performance metrics such as false acceptance rate (FAR) and false rejection rate (FRR) than other existing approaches. In addition, the power consumption analysis also shows that the proposed ECG-IJS scheme can achieve energy efficiency for BANs.

  16. ECG-based heartbeat classification for arrhythmia detection: A survey.

    PubMed

    Luz, Eduardo José da S; Schwartz, William Robson; Cámara-Chávez, Guillermo; Menotti, David

    2016-04-01

    An electrocardiogram (ECG) measures the electric activity of the heart and has been widely used for detecting heart diseases due to its simplicity and non-invasive nature. By analyzing the electrical signal of each heartbeat, i.e., the combination of action impulse waveforms produced by different specialized cardiac tissues found in the heart, it is possible to detect some of its abnormalities. In the last decades, several works were developed to produce automatic ECG-based heartbeat classification methods. In this work, we survey the current state-of-the-art methods of ECG-based automated abnormalities heartbeat classification by presenting the ECG signal preprocessing, the heartbeat segmentation techniques, the feature description methods and the learning algorithms used. In addition, we describe some of the databases used for evaluation of methods indicated by a well-known standard developed by the Association for the Advancement of Medical Instrumentation (AAMI) and described in ANSI/AAMI EC57:1998/(R)2008 (ANSI/AAMI, 2008). Finally, we discuss limitations and drawbacks of the methods in the literature presenting concluding remarks and future challenges, and also we propose an evaluation process workflow to guide authors in future works.

  17. Inkjet printed ECG electrodes for long term biosignal monitoring in personalized and ubiquitous healthcare.

    PubMed

    Batchelor, John C; Casson, Alexander J

    2015-08-01

    This paper investigates the performance of inkjet printed electrodes for electrocardiogram (ECG) monitoring in personalized and ubiquitous healthcare. As a rapid prototyping, additive manufacturing approach, inkjet printing can allow personalization of electrode sizes and shapes and can be used with a range of substrates to achieve good long term connections to the skin. We compare the performance of two types of inkjet electrodes printed using different substrates. Results demonstrate that both new electrodes can record ECG information, with comparable signal-to-noise ratios to conventional Ag/AgCl electrodes. The time-frequency decomposition of the collected signals is also explored.

  18. Simple method for adaptive filtering of motion artifacts in E-textile wearable ECG sensors.

    PubMed

    Alkhidir, Tamador; Sluzek, Andrzej; Yapici, Murat Kaya

    2015-08-01

    In this paper, we have developed a simple method for adaptive out-filtering of the motion artifact from the electrocardiogram (ECG) obtained by using conductive textile electrodes. The textile electrodes were placed on the left and the right wrist to measure ECG through lead-1 configuration. The motion artifact was induced by simple hand movements. The reference signal for adaptive filtering was obtained by placing additional electrodes at one hand to capture the motion of the hand. The adaptive filtering was compared to independent component analysis (ICA) algorithm. The signal-to-noise ratio (SNR) for the adaptive filtering approach was higher than independent component analysis in most cases.

  19. A low-power portable ECG sensor interface with dry electrodes

    NASA Astrophysics Data System (ADS)

    Xiaofei, Pu; Lei, Wan; Hui, Zhang; Yajie, Qin; Zhiliang, Hong

    2013-05-01

    This paper describes a low-power portable sensor interface dedicated to sensing and processing electrocardiogram (ECG) signals. Dry electrodes were employed in this ECG sensor, which eliminates the need of conductive gel and avoids complicated and mandatory skin preparation before electrode attachment. This ECG sensor system consists of two ICs, an analog front-end (AFE) and a successive approximation register analog-to-digital converter (SAR ADC) containing a relaxation oscillator. This proposed design was fabricated in a 0.18 μm 1P6M standard CMOS process. The AFE for extracting the biopotential signals is essential in this ECG sensor. In measurements, the AFE obtains a mid-band gain of 45 dB, a bandwidth from 0.6 to 160 Hz, and a total input referred noise of 2.8 μV rms while consuming 1 μW from the 1.8 V supply. The noise efficiency factor (NEF) of our design is 3.4. After conditioning, the amplified ECG signal is digitized by a 12-bit SAR ADC with 61.8 dB SNDR and 220 fJ/conversion-step. Finally, a complete ECG sensor interface with three dry copper electrodes is demonstrated in real-word setting, showing successful recordings of a capture ECG waveform.

  20. Synthetic ECG Generation and Bayesian Filtering Using a Gaussian Wave-Based Dynamical Model

    PubMed Central

    Sayadi, Omid; Shamsollahi, Mohammad B.; Clifford, Gari D.

    2011-01-01

    In this paper, we describe a Gaussian wave-based state space to model the temporal dynamics of electrocardiogram (ECG) signals. It is shown that this model may be effectively used for generating synthetic ECGs as well as separate characteristic waves (CWs) such as the atrial and ventricular complexes. The model uses separate state variables for each CW, i.e. P, QRS and T, and hence is capable of generating individual synthetic CWs as well as realistic ECG signals. The model is therefore useful for generating arrhythmias. Simulations of sinus bradycardia, sinus tachycardia, ventricular flutter, atrial fibrillation, and ventricular tachycardia are presented. In addition, discrete versions of the equations are presented for a model-based Bayesian framework for denoising. This framework, together with an extended Kalman filter (EKF) and extended Kalman smoother (EKS), were used for denoising the ECG for both normal rhythms and arrhythmias. For evaluating the denoising performance the signal-to-noise ratio (SNR) improvement of the filter outputs and clinical parameter stability were studied. The results demonstrate superiority over a wide range of input SNRs, achieving a maximum 12.7 dB improvement. Results indicate that preventing clinically relevant distortion of the ECG is sensitive to the number of model parameters. Models are presented which do not exhibit such distortions. The approach presented in this paper may therefore serve as an effective framework for synthetic ECG generation and model-based filtering of noisy ECG recordings. PMID:20720288

  1. Prevalence of abnormal ECGs in male soccer players decreases with the Seattle criteria, but is still high.

    PubMed

    Berge, H M; Gjesdal, K; Andersen, T E; Solberg, E E; Steine, K

    2015-08-01

    Electrocardiogram (ECG) and echocardiography are mandatory in preparticipation cardiac screening in soccer players. Abnormal ECG findings usually require follow-up investigations. The main aim of this study was to compare the prevalence of abnormal ECG findings in male professional soccer players according to European Society of Cardiology's (ESC) recommendations and the Seattle criteria, and to assess the need for echocardiography. ECGs from 587 of 595 (99%) players were recorded with ClickECG, and measurements were derived with visually adjusted on-screen calipers on the computer-based averaged PQRST complex. Echocardiographic recordings were performed with Vivid 7/i and categorized according to reference values for athlete's heart. After the initial screening, 32 (5.5%) players were recommended for follow-up. The prevalence of abnormal ECGs was 29.3% vs 11.2% according to the ESC's recommendations and the Seattle criteria, respectively. None of the players with abnormal ECGs only according to the ESC's recommendations had abnormal echocardiograms. Echocardiography alone detected one player with abnormalities (athlete's heart). The Seattle criteria reduced the number of athletes with abnormal ECGs considerably compared with the ESC recommendations. Based on echocardiographic evaluations, this increased the specificity of the Seattle criteria, without increasing the number of false-negative ECGs. The need for mandatory echocardiography in soccer players seems limited.

  2. [Research on ECG de-noising method based on ensemble empirical mode decomposition and wavelet transform using improved threshold function].

    PubMed

    Ye, Linlin; Yang, Dan; Wang, Xu

    2014-06-01

    A de-noising method for electrocardiogram (ECG) based on ensemble empirical mode decomposition (EEMD) and wavelet threshold de-noising theory is proposed in our school. We decomposed noised ECG signals with the proposed method using the EEMD and calculated a series of intrinsic mode functions (IMFs). Then we selected IMFs and reconstructed them to realize the de-noising for ECG. The processed ECG signals were filtered again with wavelet transform using improved threshold function. In the experiments, MIT-BIH ECG database was used for evaluating the performance of the proposed method, contrasting with de-noising method based on EEMD and wavelet transform with improved threshold function alone in parameters of signal to noise ratio (SNR) and mean square error (MSE). The results showed that the ECG waveforms de-noised with the proposed method were smooth and the amplitudes of ECG features did not attenuate. In conclusion, the method discussed in this paper can realize the ECG denoising and meanwhile keep the characteristics of original ECG signal. PMID:25219236

  3. Reduction of Motion Artifacts and Improvement of R Peak Detecting Accuracy Using Adjacent Non-Intrusive ECG Sensors

    PubMed Central

    Choi, Minho; Jeong, Jae Jin; Kim, Seung Hun; Kim, Sang Woo

    2016-01-01

    Non-intrusive electrocardiogram (ECG) monitoring has many advantages: easy to measure and apply in daily life. However, motion noise in the measured signal is the major problem of non-intrusive measurement. This paper proposes a method to reduce the noise and to detect the R peaks of ECG in a stable manner in a sitting arrangement using non-intrusive sensors. The method utilizes two capacitive ECG sensors (cECGs) to measure ECG, and another two cECGs located adjacent to the sensors for ECG are added to obtain the information on motion. Then, active noise cancellation technique and the motion information are used to reduce motion noise. To verify the proposed method, ECG was measured indoors and during driving, and the accuracy of the detected R peaks was compared. After applying the method, the sum of sensitivity and positive predictivity increased 8.39% on average and 26.26% maximally in the data. Based on the results, it was confirmed that the motion noise was reduced and that more reliable R peak positions could be obtained by the proposed method. The robustness of the new ECG measurement method will elicit benefits to various health care systems that require noninvasive heart rate or heart rate variability measurements. PMID:27196910

  4. [Research on ECG de-noising method based on ensemble empirical mode decomposition and wavelet transform using improved threshold function].

    PubMed

    Ye, Linlin; Yang, Dan; Wang, Xu

    2014-06-01

    A de-noising method for electrocardiogram (ECG) based on ensemble empirical mode decomposition (EEMD) and wavelet threshold de-noising theory is proposed in our school. We decomposed noised ECG signals with the proposed method using the EEMD and calculated a series of intrinsic mode functions (IMFs). Then we selected IMFs and reconstructed them to realize the de-noising for ECG. The processed ECG signals were filtered again with wavelet transform using improved threshold function. In the experiments, MIT-BIH ECG database was used for evaluating the performance of the proposed method, contrasting with de-noising method based on EEMD and wavelet transform with improved threshold function alone in parameters of signal to noise ratio (SNR) and mean square error (MSE). The results showed that the ECG waveforms de-noised with the proposed method were smooth and the amplitudes of ECG features did not attenuate. In conclusion, the method discussed in this paper can realize the ECG denoising and meanwhile keep the characteristics of original ECG signal.

  5. Reduction of Motion Artifacts and Improvement of R Peak Detecting Accuracy Using Adjacent Non-Intrusive ECG Sensors.

    PubMed

    Choi, Minho; Jeong, Jae Jin; Kim, Seung Hun; Kim, Sang Woo

    2016-01-01

    Non-intrusive electrocardiogram (ECG) monitoring has many advantages: easy to measure and apply in daily life. However, motion noise in the measured signal is the major problem of non-intrusive measurement. This paper proposes a method to reduce the noise and to detect the R peaks of ECG in a stable manner in a sitting arrangement using non-intrusive sensors. The method utilizes two capacitive ECG sensors (cECGs) to measure ECG, and another two cECGs located adjacent to the sensors for ECG are added to obtain the information on motion. Then, active noise cancellation technique and the motion information are used to reduce motion noise. To verify the proposed method, ECG was measured indoors and during driving, and the accuracy of the detected R peaks was compared. After applying the method, the sum of sensitivity and positive predictivity increased 8.39% on average and 26.26% maximally in the data. Based on the results, it was confirmed that the motion noise was reduced and that more reliable R peak positions could be obtained by the proposed method. The robustness of the new ECG measurement method will elicit benefits to various health care systems that require noninvasive heart rate or heart rate variability measurements. PMID:27196910

  6. High-frequency ECG

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    The standard ECG is by convention limited to 0.05-150 Hz, but higher frequencies are also present in the ECG signal. With high-resolution technology, it is possible to record and analyze these higher frequencies. The highest amplitudes of the high-frequency components are found within the QRS complex. In past years, the term "high frequency", "high fidelity", and "wideband electrocardiography" have been used by several investigators to refer to the process of recording ECGs with an extended bandwidth of up to 1000 Hz. Several investigators have tried to analyze HF-QRS with the hope that additional features seen in the QRS complex would provide information enhancing the diagnostic value of the ECG. The development of computerized ECG-recording devices that made it possible to record ECG signals with high resolution in both time and amplitude, as well as better possibilities to store and process the signals digitally, offered new methods for analysis. Different techniques to extract the HF-QRS have been described. Several bandwidths and filter types have been applied for the extraction as well as different signal-averaging techniques for noise reduction. There is no standard method for acquiring and quantifying HF-QRS. The physiological mechanisms underlying HF-QRS are still not fully understood. One theory is that HF-QRS are related to the conduction velocity and the fragmentation of the depolarization wave in the myocardium. In a three-dimensional model of the ventricles with a fractal conduction system it was shown that high numbers of splitting branches are associated with HF-QRS. In this experiment, it was also shown that the changes seen in HF-QRS in patients with myocardial ischemia might be due to the slowing of the conduction velocity in the region of ischemia. This mechanism has been tested by Watanabe et al by infusing sodium channel blockers into the left anterior descending artery in dogs. In their study, 60 unipolar ECGs were recorded from the entire

  7. Electrocardiogram of the Mixmaster universe

    NASA Astrophysics Data System (ADS)

    Bini, Donato; Cherubini, Christian; Geralico, Andrea; Jantzen, Robert T.

    2009-01-01

    The Mixmaster dynamics is revisited in a new light as revealing a series of transitions in the complex scale invariant scalar invariant of the Weyl curvature tensor best represented by the speciality index \\mathcal{S} , which gives a four-dimensional measure of the evolution of the spacetime independent of all the three-dimensional gauge-dependent variables except for the time used to parametrize it. Its graph versus time characterized by correlated isolated pulses in its real and imaginary parts corresponding to curvature wall collisions serves as a sort of electrocardiogram of the Mixmaster universe, with each such pulse pair arising from a single circuit or 'complex pulse' around the origin in the complex plane. These pulses in the speciality index and their limiting points on the real axis seem to invariantly characterize some of the so-called spike solutions in inhomogeneous cosmology and should play an important role as a gauge-invariant lens through which to view current investigations of inhomogeneous Mixmaster dynamics.

  8. Enhancement of low sampling frequency recordings for ECG biometric matching using interpolation.

    PubMed

    Sidek, Khairul Azami; Khalil, Ibrahim

    2013-01-01

    Electrocardiogram (ECG) based biometric matching suffers from high misclassification error with lower sampling frequency data. This situation may lead to an unreliable and vulnerable identity authentication process in high security applications. In this paper, quality enhancement techniques for ECG data with low sampling frequency has been proposed for person identification based on piecewise cubic Hermite interpolation (PCHIP) and piecewise cubic spline interpolation (SPLINE). A total of 70 ECG recordings from 4 different public ECG databases with 2 different sampling frequencies were applied for development and performance comparison purposes. An analytical method was used for feature extraction. The ECG recordings were segmented into two parts: the enrolment and recognition datasets. Three biometric matching methods, namely, Cross Correlation (CC), Percent Root-Mean-Square Deviation (PRD) and Wavelet Distance Measurement (WDM) were used for performance evaluation before and after applying interpolation techniques. Results of the experiments suggest that biometric matching with interpolated ECG data on average achieved higher matching percentage value of up to 4% for CC, 3% for PRD and 94% for WDM. These results are compared with the existing method when using ECG recordings with lower sampling frequency. Moreover, increasing the sample size from 56 to 70 subjects improves the results of the experiment by 4% for CC, 14.6% for PRD and 0.3% for WDM. Furthermore, higher classification accuracy of up to 99.1% for PCHIP and 99.2% for SPLINE with interpolated ECG data as compared of up to 97.2% without interpolation ECG data verifies the study claim that applying interpolation techniques enhances the quality of the ECG data. PMID:23062461

  9. The Electrocardiogram as an Example of Electrostatics

    ERIC Educational Resources Information Center

    Hobbie, Russell K.

    1973-01-01

    Develops a simplified electrostatic model of the heart with conduction within the torso neglected to relate electrocardiogram patterns to the charge distribution within the myocardium. Suggests its application to explanation of Coulomb's law in general physics. (CC)

  10. Accuracy of remote electrocardiogram interpretation with the use of Google Glass technology.

    PubMed

    Jeroudi, Omar M; Christakopoulos, George; Christopoulos, George; Kotsia, Anna; Kypreos, Megan A; Rangan, Bavana V; Banerjee, Subhash; Brilakis, Emmanouil S

    2015-02-01

    We sought to investigate the accuracy of remote electrocardiogram (ECG) interpretation using Google Glass (Google, Mountain View, California). Google Glass is an optical head mounted display device with growing applications in medicine. We compared interpretation of 10 ECGs with 21 clinically important findings by faculty and fellow cardiologists by (1) viewing the electrocardiographic image at the Google Glass screen; (2) viewing a photograph of the ECG taken using Google Glass and interpreted on a mobile device; (3) viewing the original paper ECG; and (4) viewing a photograph of the ECG taken with a high-resolution camera and interpreted on a mobile device. One point was given for identification of each correct finding. Subjective rating of the user experience was also recorded. Twelve physicians (4 faculty and 8 fellow cardiologists) participated. The average electrocardiographic interpretation score (maximum 21 points) as viewed through the Google Glass, Google Glass photograph on a mobile device, on paper, and high-resolution photograph on a mobile device was 13.5 ± 1.8, 16.1 ± 2.6, 18.3 ± 1.7, and 18.6 ± 1.5, respectively (p = 0.0005 between Google Glass and mobile device, p = 0.0005 between Google Glass and paper, and p = 0.002 between mobile device and paper). Of the 12 physicians, 9 (75%) were dissatisfied with ECGs viewing on the prism display of Google Glass. In conclusion, further improvements are needed before Google Glass can be reliably used for remote electrocardiographic analysis.

  11. Towards numerical temporal-frequency system modelling of associations between electrocardiogram and ballistocardiogram.

    PubMed

    Srinivasan, Aravind; Zhang, Haihong; Lin, Zhiping; Biswas, Jit; Chen, Zhihao

    2015-01-01

    Ballistocardiogram (BCG) is a vital sign of ballistic forces generated by each heartbeat. With the advancements in related sensor and computing technologies in recent years, BCG has become far more accessible and thus regained its interest in both research and industry fields. Here we would like to promote the system modelling approach to BCG computing that allows to explore the underlying association between BCG and other physiological signals such as electrocardiogram (ECG). This is in contrast to most of the existing works in the related signal processing domain, which focus on detecting heart rate only. The system modelling approach may eventually improve the clinical significance of the BCG by extracting deeply embedded information. Towards this goal, here we present our preliminary study where we design a Wavelet-based temporal-frequency system model for associating BCG and ECG. To validate the model, we also collect simultaneous BCG and ECG recordings from 4 healthy subjects. We use the system model to build a BCG to ECG predicting algorithm. We demonstrate that this temporal-frequency model and algorithm is far superior, in terms of accuracy, to the naïve method of linear modelling. PMID:26736282

  12. Heart rate variability and electrocardiogram waveform as predictors of morbidity during hypothermia and rewarming in rats.

    PubMed

    Matthew, C B; Bastille, A M; Gonzalez, R R; Sils, I V

    2002-09-01

    This study examined electrocardiogram (ECG) waveform, heart rate (HR), mean blood pressure (BP), and HR variability as potential autonomic signatures of hypothermia and rewarming. Adult male Sprague-Dawley rats had telemetry transmitters surgically implanted, and 2 weeks were allowed for recovery prior to induction of hypothermia. Rats were lightly anesthetized (sodium pentobarbital, 35 mg/kg i.p.) and placed in a coil of copper tubing through which temperature-controlled water was circulated. Animals were cooled to a core temperature (Tc) of 20 degrees C, maintained there for 30 min, and then rewarmed. Data (Tc, BP, HR from ECG, and 10-s strips of ECG waveforms) were collected every 5 min throughout hypothermia and rewarming. Both HR and BP declined after initial increases with the drop in HR starting at a higher Tc than the drop in BP (29.6 +/- 2.4 degrees C vs. 27.1 +/- 3.3 degrees C, p < 0.05). Animals that were not successfully rewarmed exhibited a significant (p < 0.05) increase in the normalized standard deviation of interbeat intervals (IBI) throughout cooling compared with animals that were successfully rewarmed. The T wave of the ECG increased in amplitude and area with decreasing Tc. T-wave amplitude and IBI variability show potential as predictors of survival in hypothermic victims.

  13. Algorithm for the classification of multi-modulating signals on the electrocardiogram.

    PubMed

    Mita, Mitsuo

    2007-03-01

    This article discusses the algorithm to measure electrocardiogram (ECG) and respiration simultaneously and to have the diagnostic potentiality for sleep apnoea from ECG recordings. The algorithm is composed by the combination with the three particular scale transform of a(j)(t), u(j)(t), o(j)(a(j)) and the statistical Fourier transform (SFT). Time and magnitude scale transforms of a(j)(t), u(j)(t) change the source into the periodic signal and tau(j) = o(j)(a(j)) confines its harmonics into a few instantaneous components at tau(j) being a common instant on two scales between t and tau(j). As a result, the multi-modulating source is decomposed by the SFT and is reconstructed into ECG, respiration and the other signals by inverse transform. The algorithm is expected to get the partial ventilation and the heart rate variability from scale transforms among a(j)(t), a(j+1)(t) and u(j+1)(t) joining with each modulation. The algorithm has a high potentiality of the clinical checkup for the diagnosis of sleep apnoea from ECG recordings.

  14. The design of heart sounds and electrocardiogram monitor system based Atmega 128L

    NASA Astrophysics Data System (ADS)

    Cao, Miao; An, Zhiyong; Zhang, Ying

    2006-11-01

    This paper introduces a realtime system which can acquire,process,store and display heart sounds and electrocardiogram(ECG) of the human body at the same time.It is composed of superior microprocessor--Atmega128L,large capacity Flash and the new type LCD.All hardwares adopt low power design and surface mounting package. The specialities of the system are low power, compact, and high intelligence. In consideration of transplant and solidity of the system, at the same time, it ensures that some complicated arithmetic can be realized.The system software applies mold construction and programs in C language. A model for automatic arithmetic is established for the feature extraction of ECG, realtime cardiotach ambulatory analysis is realized. The system is capable of recording ECG and heart sounds information in succession for 48 hours and it stores the no compression data synchronously. More than ten types of familiar heart diseases can be diagnosed in time by it automatically. The testing data achieved from this system is dependable, the diagnosing result is accurate and the waveform is no distortion. It solved a problem within the same kind of products effectively, that is, the dynamic ECG and heart sounds signal are acquired separately. The system do not affect the daily living and working of human being when it is used, so it is suited for clinical and family monitoring.

  15. Natural environmental associations in a 50-day human electrocardiogram.

    PubMed

    Delyukov, A; Gorgo, Y; Cornélissen, G; Otsuka, K; Halberg, F

    2001-07-01

    Meteorotropic associations of heart rate (HR) and HR variability (HRV) were investigated in a clinically healthy 48-year-old man in Kiev. His electrocardiogram (ECG) was determined over 50 days by fitting him with an ambulatorily wearable device; various natural physical environmental variables were also monitored. The mean inter-beat interval, the standard deviation of these intervals, the spectral power in several frequency ranges, the power ratio of the approx. 10.5-s/approx. 3.6-s spectral components and other aspects of HRV were computed over consecutive 14.4-min intervals. Together with ordinary meteorological variables, geomagnetic disturbances (GMD) and fluctuations of atmospheric pressure (FAP) in the range 0.01-0.10 Hz (10-100 s) were measured. The assessable infradian spectra (with frequencies lower than 1 cycle/28 hours) of all HRV parameters showed two major components with periods of about 3.5 and 10 days. Two environmental variables, FAP and wind speed (with which FAP is closely related), revealed both of these rhythms and showed the greatest cross-spectral coherence (0.70-0.98) with corresponding oscillations of HRV. Less specific but statistically significant product-moment correlations with major HRV indices were also found; most of these were with FAP, but correlations with air temperature, humidity, wind speed and geomagnetic disturbances were also found. Long-term ECG recording, essential in the detection of infradian rhythms, proved to be sensitive to physical environmental variables, notably meteorological ones. FAP, usually neglected since its role has not been considered in previous biometeorological studies, or some factor closely related to FAP is probably involved in synchronizing or influencing the approximately 3.5-day HR and HRV rhythms in humans.

  16. A normal electrocardiogram precludes the need for left ventriculography in the assessment of coronary artery disease

    PubMed Central

    Khan, M; Sinha, S; Hayton, S; Fynn, S; Henderson, R; Bennett, D

    1998-01-01

    Objective—To assess whether a normal electrocardiogram can identify good left ventricular function and obviate the need for routine left ventriculography in patients undergoing cardiac catheterisation for suspected coronary artery disease.
Design—A prospective study of patients undergoing cardiac catheterisation.
Setting—A regional cardiac centre.
Patients—The electrocardiograms, coronary angiograms, and left ventriculograms of 391 consecutive patients undergoing investigations for suspected coronary artery disease were entered into the study. Patients with arrhythmias and cardiac pathologies other than coronary artery disease were excluded.
Main outcome measures—The electrocardiogram was assessed using a 29 point QRS scoring system, and classified by two cardiologists and a trainee cardiologist as normal or abnormal. Left ventricular function was assessed by digital ventriculography.
Results—The sensitivity, specificity, and negative predictive value of a QRS score of 0 (normal QRS complexes) for discriminating good left ventricular function (ejection fraction ⩾ 50%) were 92.6%, 41.5%, and 97.2%, respectively. The figures for a normal electrocardiogram as assessed by a doctor were 96.3%, 40.4%, and 98.6% for cardiologist A; 96.3%, 37.4%, and 98.4% for cardiologist B; and 94.4%, 49.6%, and 98.2% for the cardiology trainee.
Conclusions—If a cardiologist judges the ECG to be normal, left ventriculography is unnecessary and a formal QRS score does not improve reliability of this clinical judgment. Adopting this strategy would save £30-40 000 in consumables and 65-87 hours of catheter laboratory and staff time for a department catheterising 3000 patients with suspected coronary artery disease annually.

 Keywords: cardiac catheterisation;  electrocardiogram;  left ventricular ejection fraction PMID:9602660

  17. Pocket ECG electrode

    NASA Technical Reports Server (NTRS)

    Lund, Gordon F. (Inventor)

    1982-01-01

    A low-noise electrode suited for sensing electrocardiograms when chronically and subcutaneously implanted in a free-ranging subject. The electrode comprises a pocket-shaped electrically conductive member with a single entrance adapted to receive body fluids. The exterior of the member and the entrance region is coated with electrical insulation so that the only electrolyte/electrode interface is within the member remote from artifact-generating tissue. Cloth straps are bonded to the member to permit the electrode to be sutured to tissue and to provide electrical lead flexure relief.

  18. Pocket ECG electrode

    NASA Technical Reports Server (NTRS)

    Lund, G. F. (Inventor)

    1980-01-01

    A low noise electrode suited for sensing electrocardiograms when chronically and subcutaneously implanted in a free ranging subject is described. The electrode comprises a pocket shaped electrically conductive member with a single entrance adapted to receive body fluids. The exterior of the member and the entrance region is coated with electrical insulation so that the only electrolyte/electrode interface is within the member, remote from artifact-generating tissue. Cloth straps are bonded to the member to permit the electrode to be sutured to tissue and to provide electrical lead flexure relief.

  19. Assessing ECG signal quality indices to discriminate ECGs with artefacts from pathologically different arrhythmic ECGs.

    PubMed

    Daluwatte, C; Johannesen, L; Galeotti, L; Vicente, J; Strauss, D G; Scully, C G

    2016-08-01

    False and non-actionable alarms in critical care can be reduced by developing algorithms which assess the trueness of an arrhythmia alarm from a bedside monitor. Computational approaches that automatically identify artefacts in ECG signals are an important branch of physiological signal processing which tries to address this issue. Signal quality indices (SQIs) derived considering differences between artefacts which occur in ECG signals and normal QRS morphology have the potential to discriminate pathologically different arrhythmic ECG segments as artefacts. Using ECG signals from the PhysioNet/Computing in Cardiology Challenge 2015 training set, we studied previously reported ECG SQIs in the scientific literature to differentiate ECG segments with artefacts from arrhythmic ECG segments. We found that the ability of SQIs to discriminate between ECG artefacts and arrhythmic ECG varies based on arrhythmia type since the pathology of each arrhythmic ECG waveform is different. Therefore, to reduce the risk of SQIs classifying arrhythmic events as noise it is important to validate and test SQIs with databases that include arrhythmias. Arrhythmia specific SQIs may also minimize the risk of misclassifying arrhythmic events as noise.

  20. Assessing ECG signal quality indices to discriminate ECGs with artefacts from pathologically different arrhythmic ECGs.

    PubMed

    Daluwatte, C; Johannesen, L; Galeotti, L; Vicente, J; Strauss, D G; Scully, C G

    2016-08-01

    False and non-actionable alarms in critical care can be reduced by developing algorithms which assess the trueness of an arrhythmia alarm from a bedside monitor. Computational approaches that automatically identify artefacts in ECG signals are an important branch of physiological signal processing which tries to address this issue. Signal quality indices (SQIs) derived considering differences between artefacts which occur in ECG signals and normal QRS morphology have the potential to discriminate pathologically different arrhythmic ECG segments as artefacts. Using ECG signals from the PhysioNet/Computing in Cardiology Challenge 2015 training set, we studied previously reported ECG SQIs in the scientific literature to differentiate ECG segments with artefacts from arrhythmic ECG segments. We found that the ability of SQIs to discriminate between ECG artefacts and arrhythmic ECG varies based on arrhythmia type since the pathology of each arrhythmic ECG waveform is different. Therefore, to reduce the risk of SQIs classifying arrhythmic events as noise it is important to validate and test SQIs with databases that include arrhythmias. Arrhythmia specific SQIs may also minimize the risk of misclassifying arrhythmic events as noise. PMID:27454007

  1. Heritability of Abnormalities in Cardiopulmonary Coupling in Sleep Apnea: Use of an Electrocardiogram-based Technique

    PubMed Central

    Ibrahim, Lamia H.; Jacono, Frank J.; Patel, Sanjay R.; Thomas, Robert J.; Larkin, Emma K.; Mietus, Joseph E.; Peng, Chung-Kang; Goldberger, Ary L.; Redline, Susan

    2010-01-01

    Rationale: Studies of the genetics of obstructive sleep apnea may be facilitated by identifying intermediate traits with high heritability that quantify etiological pathways, such as those related to respiratory control. Electrocardiogram (ECG)-based sleep spectrograms, measuring the coupling between respiratory modulation of ECG QRS-wave amplitude and heart rate variability, may provide measures of sleep state and ventilatory dynamics during sleep. We evaluated the familial aggregation of distinctive spectrographic biomarkers of unstable sleep, related to elevated-low frequency cardiopulmonary coupling (e-LFC), to assess their utility in genetic studies. Methods: 622 participants from 137 families from the Cleveland Family Study underwent standardized polysomnography (PSG). From the ECG signal on the PSG, the interbeat interval time series and the corresponding ECG-derived respiratory signal were extracted, and the low frequency (0.01-0.1 Hz) component of their coupling was computed using a fully automated method. Narrow sense heritability of e-LFC was calculated using variance component methods. Results: A spectral marker of abnormal low frequency cardiopulmonary coupling (e-LFC) demonstrated moderate correlation with apnea hypopnea index (AHI; r = 0.35, P < 0.0001). The heritability estimate for e-LFC, after adjusting for age and sex was 0.32 (P < 10-5) and remained unchanged after additionally adjusting for body mass index or AHI. In biological relatives of those with sleep apnea, a related marker of e-LFC was more prevalent than in controls (P = 0.05). Conclusions: Approximately 30% of the variability of e-LFC, measured from a continuous ECG during sleep, is explained by familial factors other than BMI. ECG-based spectrographic measures of cardiopulmonary coupling may provide novel phenotypes for characterizing subgroups of individuals with different propensities and genetic etiologies for sleep apnea or for other conditions associated with sleep fragmentation

  2. A novel LabVIEW-based multi-channel non-invasive abdominal maternal-fetal electrocardiogram signal generator.

    PubMed

    Martinek, Radek; Kelnar, Michal; Koudelka, Petr; Vanus, Jan; Bilik, Petr; Janku, Petr; Nazeran, Homer; Zidek, Jan

    2016-02-01

    This paper describes the design, construction, and testing of a multi-channel fetal electrocardiogram (fECG) signal generator based on LabVIEW. Special attention is paid to the fetal heart development in relation to the fetus' anatomy, physiology, and pathology. The non-invasive signal generator enables many parameters to be set, including fetal heart rate (FHR), maternal heart rate (MHR), gestational age (GA), fECG interferences (biological and technical artifacts), as well as other fECG signal characteristics. Furthermore, based on the change in the FHR and in the T wave-to-QRS complex ratio (T/QRS), the generator enables manifestations of hypoxic states (hypoxemia, hypoxia, and asphyxia) to be monitored while complying with clinical recommendations for classifications in cardiotocography (CTG) and fECG ST segment analysis (STAN). The generator can also produce synthetic signals with defined properties for 6 input leads (4 abdominal and 2 thoracic). Such signals are well suited to the testing of new and existing methods of fECG processing and are effective in suppressing maternal ECG while non-invasively monitoring abdominal fECG. They may also contribute to the development of a new diagnostic method, which may be referred to as non-invasive trans-abdominal CTG +  STAN. The functional prototype is based on virtual instrumentation using the LabVIEW developmental environment and its associated data acquisition measurement cards (DAQmx). The generator also makes it possible to create synthetic signals and measure actual fetal and maternal ECGs by means of bioelectrodes.

  3. A novel LabVIEW-based multi-channel non-invasive abdominal maternal-fetal electrocardiogram signal generator.

    PubMed

    Martinek, Radek; Kelnar, Michal; Koudelka, Petr; Vanus, Jan; Bilik, Petr; Janku, Petr; Nazeran, Homer; Zidek, Jan

    2016-02-01

    This paper describes the design, construction, and testing of a multi-channel fetal electrocardiogram (fECG) signal generator based on LabVIEW. Special attention is paid to the fetal heart development in relation to the fetus' anatomy, physiology, and pathology. The non-invasive signal generator enables many parameters to be set, including fetal heart rate (FHR), maternal heart rate (MHR), gestational age (GA), fECG interferences (biological and technical artifacts), as well as other fECG signal characteristics. Furthermore, based on the change in the FHR and in the T wave-to-QRS complex ratio (T/QRS), the generator enables manifestations of hypoxic states (hypoxemia, hypoxia, and asphyxia) to be monitored while complying with clinical recommendations for classifications in cardiotocography (CTG) and fECG ST segment analysis (STAN). The generator can also produce synthetic signals with defined properties for 6 input leads (4 abdominal and 2 thoracic). Such signals are well suited to the testing of new and existing methods of fECG processing and are effective in suppressing maternal ECG while non-invasively monitoring abdominal fECG. They may also contribute to the development of a new diagnostic method, which may be referred to as non-invasive trans-abdominal CTG +  STAN. The functional prototype is based on virtual instrumentation using the LabVIEW developmental environment and its associated data acquisition measurement cards (DAQmx). The generator also makes it possible to create synthetic signals and measure actual fetal and maternal ECGs by means of bioelectrodes. PMID:26799770

  4. The highly-cited Electrocardiogram-related articles in science citation index expanded: characteristics and hotspots.

    PubMed

    Yang, Xianglin; Gu, Jiaojiao; Yan, Hong; Xu, Zhi; Ren, Bing; Yang, Yaming; Yang, Xiaodong; Chen, Qi; Tan, Shaohua

    2014-01-01

    We used bibliometric analysis methodology in the expanded Science Citation Index to identify highly-cited electrocardiogram (ECG)-related articles with total citations (TC2012) exceeding 100 from the publication year to 2012. Web of Science search tools were used to identify the highly-cited articles. The aspects analyzed for highly cited publications included effect of time on citation analysis, journals and Web of Science categories, number of authors per publication, originating institutions and countries, total citation and total citation per year life cycles of articles (C2012) and research hotspots. Results showed that a total of 467 electrocardiogram-related publications were regarded as the highly-cited publications. TC2012 ranged from 101 to 2879, with 215 as the average number of citations. No highly-cited publications have emerged yet during the first two years of the present 2010 Decade. All 11 countries and institutions originating highly-cited ECG-related publications were developed countries, USA in 9 of them. Four subject categories were identified as hotspots by total citations TC2012 and C2012: atrial fibrillation, long QT syndrome, angina and myocardial infarction, and risk factor analysis and health evaluation.

  5. Detection of Cardiac Abnormalities from Multilead ECG using Multiscale Phase Alternation Features.

    PubMed

    Tripathy, R K; Dandapat, S

    2016-06-01

    The cardiac activities such as the depolarization and the relaxation of atria and ventricles are observed in electrocardiogram (ECG). The changes in the morphological features of ECG are the symptoms of particular heart pathology. It is a cumbersome task for medical experts to visually identify any subtle changes in the morphological features during 24 hours of ECG recording. Therefore, the automated analysis of ECG signal is a need for accurate detection of cardiac abnormalities. In this paper, a novel method for automated detection of cardiac abnormalities from multilead ECG is proposed. The method uses multiscale phase alternation (PA) features of multilead ECG and two classifiers, k-nearest neighbor (KNN) and fuzzy KNN for classification of bundle branch block (BBB), myocardial infarction (MI), heart muscle defect (HMD) and healthy control (HC). The dual tree complex wavelet transform (DTCWT) is used to decompose the ECG signal of each lead into complex wavelet coefficients at different scales. The phase of the complex wavelet coefficients is computed and the PA values at each wavelet scale are used as features for detection and classification of cardiac abnormalities. A publicly available multilead ECG database (PTB database) is used for testing of the proposed method. The experimental results show that, the proposed multiscale PA features and the fuzzy KNN classifier have better performance for detection of cardiac abnormalities with sensitivity values of 78.12 %, 80.90 % and 94.31 % for BBB, HMD and MI classes. The sensitivity value of proposed method for MI class is compared with the state-of-art techniques from multilead ECG. PMID:27118009

  6. ECG boy: low-cost medical instrumentation using mass-produced, hand-held entertainment computers. A preliminary report.

    PubMed

    Rohde, M M; Bement, S L; Lupa, R S

    1998-01-01

    A prototype low-cost, portable ECG monitor, the "ECG Boy," is described. A mass produced hand-held video game platform is the basis for a complete three-lead, driven right-leg electrocardiogram (ECG). The ECG circuitry is planned to fit in a standard modular cartridge that is inserted in a production Nintendo "Gameboy." The combination is slightly smaller than a paperback book and weighs less than 500 g. The unit contains essential safety features such as optical isolation and is powered by 9-V and AA batteries. Functionally, the ECG Boy permits viewing ECG recordings in real time on the integrated screen. The user can select both the lead displayed on the screen and the time scale used. A 1-mV reference allows for calibration. Other ECG enhancements such as data transmission via telephone can be easily and inexpensively added to this system. The ECG Boy is intended as a proof of concept for a new class of low-cost biomedical instruments. Rising health care costs coupled with tightened funding have created an acute demand for low-cost medical equipment that satisfies safety and quality standards. A mass-produced microprocessor-based platform designed for the entertainment market can keep costs low while providing a functional basis for a biomedical instrument.

  7. A miniature on-chip multi-functional ECG signal processor with 30 µW ultra-low power consumption.

    PubMed

    Liu, Xin; Zheng, Yuan Jin; Phyu, Myint Wai; Zhao, Bin; Je, Minkyu; Yuan, Xiao Jun

    2010-01-01

    In this paper, a miniature low-power Electrocardiogram (ECG) signal processing application specific integrated circuit (ASIC) chip is proposed. This chip provides multiple critical functions for ECG analysis using a systematic wavelet transform algorithm and a novel SRAM-based ASIC architecture, while achieves low cost and high performance. Using 0.18 µm CMOS technology and 1 V power supply, this ASIC chip consumes only 29 µW and occupies an area of 3 mm(2). This on-chip ECG processor is highly suitable for reliable real-time cardiac status monitoring applications.

  8. A robust approach for ECG-based analysis of cardiopulmonary coupling.

    PubMed

    Zheng, Jiewen; Wang, Weidong; Zhang, Zhengbo; Wu, Dalei; Wu, Hao; Peng, Chung-Kang

    2016-07-01

    Deriving respiratory signal from a surface electrocardiogram (ECG) measurement has advantage of simultaneously monitoring of cardiac and respiratory activities. ECG-based cardiopulmonary coupling (CPC) analysis estimated by heart period variability and ECG-derived respiration (EDR) shows promising applications in medical field. The aim of this paper is to provide a quantitative analysis of the ECG-based CPC, and further improve its performance. Two conventional strategies were tested to obtain EDR signal: R-S wave amplitude and area of the QRS complex. An adaptive filter was utilized to extract the common component of inter-beat interval (RRI) and EDR, generating enhanced versions of EDR signal. CPC is assessed through probing the nonlinear phase interactions between RRI series and respiratory signal. Respiratory oscillations presented in both RRI series and respiratory signals were extracted by ensemble empirical mode decomposition for coupling analysis via phase synchronization index. The results demonstrated that CPC estimated from conventional EDR series exhibits constant and proportional biases, while that estimated from enhanced EDR series is more reliable. Adaptive filtering can improve the accuracy of the ECG-based CPC estimation significantly and achieve robust CPC analysis. The improved ECG-based CPC estimation may provide additional prognostic information for both sleep medicine and autonomic function analysis. PMID:27118307

  9. Research of fetal ECG extraction using wavelet analysis and adaptive filtering.

    PubMed

    Wu, Shuicai; Shen, Yanni; Zhou, Zhuhuang; Lin, Lan; Zeng, Yanjun; Gao, Xiaofeng

    2013-10-01

    Extracting clean fetal electrocardiogram (ECG) signals is very important in fetal monitoring. In this paper, we proposed a new method for fetal ECG extraction based on wavelet analysis, the least mean square (LMS) adaptive filtering algorithm, and the spatially selective noise filtration (SSNF) algorithm. First, abdominal signals and thoracic signals were processed by stationary wavelet transform (SWT), and the wavelet coefficients at each scale were obtained. For each scale, the detail coefficients were processed by the LMS algorithm. The coefficient of the abdominal signal was taken as the original input of the LMS adaptive filtering system, and the coefficient of the thoracic signal as the reference input. Then, correlations of the processed wavelet coefficients were computed. The threshold was set and noise components were removed with the SSNF algorithm. Finally, the processed wavelet coefficients were reconstructed by inverse SWT to obtain fetal ECG. Twenty cases of simulated data and 12 cases of clinical data were used. Experimental results showed that the proposed method outperforms the LMS algorithm: (1) it shows improvement in case of superposition R-peaks of fetal ECG and maternal ECG; (2) noise disturbance is eliminated by incorporating the SSNF algorithm and the extracted waveform is more stable; and (3) the performance is proven quantitatively by SNR calculation. The results indicated that the proposed algorithm can be used for extracting fetal ECG from abdominal signals.

  10. Performance evaluation of carbon black based electrodes for underwater ECG monitoring.

    PubMed

    Reyes, Bersain A; Posada-Quintero, Hugo F; Bales, Justin R; Chon, Ki H

    2014-01-01

    Underwater electrocardiogram (ECG) monitoring currently uses Ag/AgCl electrodes and requires sealing of the electrodes to avoid water intrusion, but this procedure is time consuming and often results in severe irritations or even tearing of the skin. To alleviate these problems, our research team developed hydrophobic electrodes comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS) that provide all morphological waveforms without distortion of an ECG signal for dry and water-immersed conditions. Performance comparison of CB/PDMS electrodes to adhesive Ag/AgCl hydrogel electrodes was carried out in three different scenarios which included recordings from a dry surface, water immersion, and post-water immersion conditions. CB/PDMS electrodes were able to acquire ECG signals highly correlated with those from adhesive Ag/AgCl electrodes during all conditions. Statistical reduction in ECG amplitude (p<0.05) was only found during the immersed condition with CB/PDMS electrodes when compared to Ag/AgCl electrodes sealed with their waterproof adhesive tape. Besides this reduction readability of the recordings was not obscured and all morphological waveforms of the ECG signal were discernible. The advantages of our CB/PDMS electrodes are that they are reusable, can be fabricated economically, and most importantly, high-fidelity underwater ECG signals can be acquired without relying on the heavy use of waterproof sealing. PMID:25570300

  11. Powerline interference reduction in ECG signals using empirical wavelet transform and adaptive filtering.

    PubMed

    Singh, Omkar; Sunkaria, Ramesh Kumar

    2015-01-01

    Separating an information-bearing signal from the background noise is a general problem in signal processing. In a clinical environment during acquisition of an electrocardiogram (ECG) signal, The ECG signal is corrupted by various noise sources such as powerline interference (PLI), baseline wander and muscle artifacts. This paper presents novel methods for reduction of powerline interference in ECG signals using empirical wavelet transform (EWT) and adaptive filtering. The proposed methods are compared with the empirical mode decomposition (EMD) based PLI cancellation methods. A total of six methods for PLI reduction based on EMD and EWT are analysed and their results are presented in this paper. The EWT-based de-noising methods have less computational complexity and are more efficient as compared with the EMD-based de-noising methods. PMID:25412942

  12. Hiding patients confidential datainthe ECG signal viaa transform-domain quantization scheme.

    PubMed

    Chen, Shuo-Tsung; Guo, Yuan-Jie; Huang, Huang-Nan; Kung, Woon-Man; Tseng, Kuo-Kun; Tu, Shu-Yi

    2014-06-01

    Watermarking is the most widely used technology in the field of copyright and biological information protection. In this paper, we use quantization based digital watermark encryption technology on the Electrocardiogram (ECG) to protect patient rights and information. Three transform domains, DWT, DCT, and DFT are adopted to implement the quantization based watermarking technique. Although the watermark embedding process is not invertible, the change of the PQRST complexes and amplitude of the ECG signal is very small and so the watermarked data can meet the requirements of physiological diagnostics. In addition, the hidden information can be extracted without knowledge of the original ECG data. In other words, the proposed watermarking scheme is blind. Experimental results verify the efficiency of the proposed scheme. PMID:24832688

  13. Reliable resource-constrained telecardiology via compressive detection of anomalous ECG signals.

    PubMed

    Chandra, Bollepalli S; Sastry, Challa S; Jana, Soumya

    2015-11-01

    Telecardiology is envisaged as a supplement to inadequate local cardiac care, especially, in infrastructure deficient communities. Yet the associated infrastructure constraints are often ignored while designing a traditional telecardiology system that simply records and transmits user electrocardiogram (ECG) signals to a professional diagnostic facility. Against this backdrop, we propose a two-tier telecardiology framework, where constraints on resources, such as power and bandwidth, are met by compressively sampling ECG signals, identifying anomalous signals, and transmitting only the anomalous signals. Specifically, we design practical compressive classifiers based on inherent properties of ECG signals, such as self-similarity and periodicity, and illustrate their efficacy by plotting receiver operating characteristics (ROC). Using such classifiers, we realize a resource-constrained telecardiology system, which, for the PhysioNet databases, allows no more than 0.5% undetected patients even at an average downsampling factor of five, reducing the power requirement by 80% and bandwidth requirement by 83.4% compared to traditional telecardiology.

  14. Wavelet-based watermarking and compression for ECG signals with verification evaluation.

    PubMed

    Tseng, Kuo-Kun; He, Xialong; Kung, Woon-Man; Chen, Shuo-Tsung; Liao, Minghong; Huang, Huang-Nan

    2014-01-01

    In the current open society and with the growth of human rights, people are more and more concerned about the privacy of their information and other important data. This study makes use of electrocardiography (ECG) data in order to protect individual information. An ECG signal can not only be used to analyze disease, but also to provide crucial biometric information for identification and authentication. In this study, we propose a new idea of integrating electrocardiogram watermarking and compression approach, which has never been researched before. ECG watermarking can ensure the confidentiality and reliability of a user's data while reducing the amount of data. In the evaluation, we apply the embedding capacity, bit error rate (BER), signal-to-noise ratio (SNR), compression ratio (CR), and compressed-signal to noise ratio (CNR) methods to assess the proposed algorithm. After comprehensive evaluation the final results show that our algorithm is robust and feasible. PMID:24566636

  15. Wavelet-Based Watermarking and Compression for ECG Signals with Verification Evaluation

    PubMed Central

    Tseng, Kuo-Kun; He, Xialong; Kung, Woon-Man; Chen, Shuo-Tsung; Liao, Minghong; Huang, Huang-Nan

    2014-01-01

    In the current open society and with the growth of human rights, people are more and more concerned about the privacy of their information and other important data. This study makes use of electrocardiography (ECG) data in order to protect individual information. An ECG signal can not only be used to analyze disease, but also to provide crucial biometric information for identification and authentication. In this study, we propose a new idea of integrating electrocardiogram watermarking and compression approach, which has never been researched before. ECG watermarking can ensure the confidentiality and reliability of a user's data while reducing the amount of data. In the evaluation, we apply the embedding capacity, bit error rate (BER), signal-to-noise ratio (SNR), compression ratio (CR), and compressed-signal to noise ratio (CNR) methods to assess the proposed algorithm. After comprehensive evaluation the final results show that our algorithm is robust and feasible. PMID:24566636

  16. Wavelet-based watermarking and compression for ECG signals with verification evaluation.

    PubMed

    Tseng, Kuo-Kun; He, Xialong; Kung, Woon-Man; Chen, Shuo-Tsung; Liao, Minghong; Huang, Huang-Nan

    2014-01-01

    In the current open society and with the growth of human rights, people are more and more concerned about the privacy of their information and other important data. This study makes use of electrocardiography (ECG) data in order to protect individual information. An ECG signal can not only be used to analyze disease, but also to provide crucial biometric information for identification and authentication. In this study, we propose a new idea of integrating electrocardiogram watermarking and compression approach, which has never been researched before. ECG watermarking can ensure the confidentiality and reliability of a user's data while reducing the amount of data. In the evaluation, we apply the embedding capacity, bit error rate (BER), signal-to-noise ratio (SNR), compression ratio (CR), and compressed-signal to noise ratio (CNR) methods to assess the proposed algorithm. After comprehensive evaluation the final results show that our algorithm is robust and feasible.

  17. ECG compression using uniform scalar dead-zone quantization and conditional entropy coding.

    PubMed

    Chen, Jianhua; Wang, Fuyan; Zhang, Yufeng; Shi, Xinling

    2008-05-01

    A new wavelet-based method for the compression of electrocardiogram (ECG) data is presented. A discrete wavelet transform (DWT) is applied to the digitized ECG signal. The DWT coefficients are first quantized with a uniform scalar dead-zone quantizer, and then the quantized coefficients are decomposed into four symbol streams, representing a binary significance stream, the signs, the positions of the most significant bits, and the residual bits. An adaptive arithmetic coder with several different context models is employed for the entropy coding of these symbol streams. Simulation results on several records from the MIT-BIH arrhythmia database show that the proposed coding algorithm outperforms some recently developed ECG compression algorithms.

  18. Community-Based ECG Monitoring System for Patients with Cardiovascular Diseases.

    PubMed

    Lin, Bor-Shyh; Wong, Alice M; Tseng, Kevin C

    2016-04-01

    This study aims to develop a community-based electrocardiogram (ECG) monitoring system for cardiac outpatients to wirelessly detect heart rate, provide personalized healthcare, and enhance interactive social contact because of the prevalence of deaths from cardiovascular disease and the growing problem of aging in the world. The system not only strengthens the performance of the ECG monitoring system but also emphasizes the ergonomic design of wearable devices and user interfaces. In addition, it enables medical professionals to diagnose cardiac symptoms remotely and electronically manage medical reports and suggestions. The experimental result shows high performance of the dry electrode, even in dynamic conditions. The comparison result with different ECG healthcare systems shows the essential factors that the system should possess and the capability of the proposed system. Finally, a user survey was conducted based on the unified theory of acceptance and users of technology (UTAUT) model.

  19. An ultra-high input impedance ECG amplifier for long-term monitoring of athletes

    PubMed Central

    Gargiulo, Gaetano; Bifulco, Paolo; Cesarelli, Mario; Ruffo, Mariano; Romano, Maria; Calvo, Rafael A; Jin, Craig; van Schaik, André

    2010-01-01

    We present a new, low-power electrocardiogram (ECG) recording system with an ultra-high input impedance that enables the use of long-lasting, dry electrodes. The system incorporates a low-power Bluetooth module for wireless connectivity and is designed to be suitable for long-term monitoring during daily activities. The new system using dry electrodes was compared with a clinically approved ECG reference system using gelled Ag/AgCl electrodes and performance was found to be equivalent. In addition, the system was used to monitor an athlete during several physical tasks, and a good quality ECG was obtained in all cases, including when the athlete was totally submerged in fresh water. PMID:22915916

  20. Cloud-ECG for real time ECG monitoring and analysis.

    PubMed

    Xia, Henian; Asif, Irfan; Zhao, Xiaopeng

    2013-06-01

    Recent advances in mobile technology and cloud computing have inspired numerous designs of cloud-based health care services and devices. Within the cloud system, medical data can be collected and transmitted automatically to medical professionals from anywhere and feedback can be returned to patients through the network. In this article, we developed a cloud-based system for clients with mobile devices or web browsers. Specially, we aim to address the issues regarding the usefulness of the ECG data collected from patients themselves. Algorithms for ECG enhancement, ECG quality evaluation and ECG parameters extraction were implemented in the system. The system was demonstrated by a use case, in which ECG data was uploaded to the web server from a mobile phone at a certain frequency and analysis was performed in real time using the server. The system has been proven to be functional, accurate and efficient. PMID:23261079

  1. Real-time ECG transmission via Internet for nonclinical applications.

    PubMed

    Hernández, A I; Mora, F; Villegas, G; Passariello, G; Carrault, G

    2001-09-01

    Telemedicine is producing a great impact in the monitoring of patients located in remote nonclinical environments such as homes, elder communities, gymnasiums, schools, remote military bases, ships, and the like. A number of applications, ranging from data collection, to chronic patient surveillance, and even to the control of therapeutic procedures, are being implemented in many parts of the world. As part of this growing trend, this paper discusses the problems in electrocardiogram (ECG) real-time data acquisition, transmission, and visualization over the Internet. ECG signals are transmitted in real time from a patient in a remote nonclinical environment to the specialist in a hospital or clinic using the current capabilities and availability of the Internet. A prototype system is composed of a portable data acquisition and preprocessing module connected to the computer in the remote site via its RS-232 port, a Java-based client-server platform, and software modules to handle communication protocols between data acquisition module and the patient's personal computer, and to handle client-server communication. The purpose of the system is the provision of extended monitoring for patients under drug therapy after infarction, data collection in some particular cases, remote consultation, and low-cost ECG monitoring for the elderly.

  2. A constrained two-layer compression technique for ECG waves.

    PubMed

    Byun, Kyungguen; Song, Eunwoo; Shim, Hwan; Lim, Hyungjoon; Kang, Hong-Goo

    2015-08-01

    This paper proposes a constrained two-layer compression technique for electrocardiogram (ECG) waves, of which encoded parameters can be directly used for the diagnosis of arrhythmia. In the first layer, a single ECG beat is represented by one of the registered templates in the codebook. Since the required coding parameter in this layer is only the codebook index of the selected template, its compression ratio (CR) is very high. Note that the distribution of registered templates is also related to the characteristics of ECG waves, thus it can be used as a metric to detect various types of arrhythmias. The residual error between the input and the selected template is encoded by a wavelet-based transform coding in the second layer. The number of wavelet coefficients is constrained by pre-defined maximum distortion to be allowed. The MIT-BIH arrhythmia database is used to evaluate the performance of the proposed algorithm. The proposed algorithm shows around 7.18 CR when the reference value of percentage root mean square difference (PRD) is set to ten. PMID:26737691

  3. Comparison of three artificial models of the MHD effect on the electrocardiogram

    PubMed Central

    Oster, Julien; Llinares, Raul; Payne, Stephen; Tse, Zion Tsz Ho; Schmidt, Ehud Jeruham; Clifford, Gari D.

    2013-01-01

    The Electrocardiogram (ECG) is often acquired during Magnetic Resonance Imaging (MRI) for both image acquisition synchronisation with heart activity and patient monitoring to alert for life-threatening events. Accurate ECG analysis is mandatory for cutting-edge applications, such as MRI guided interventions. Nevertheless, the majority of the clinical analysis of ECG acquired inside MRI is made difficult by the superposition of a voltage called the MagnetoHydroDynamic (MHD) effect. MHD is induced by the flow of electrically charged particles in the blood perpendicular to the static magnetic field, which creates a potential of the order of magnitude of the ECG and temporally coincident with the repolatisation period. In this study, a new MHD model is proposed which is an extension of several existing models and incorporates MRI-based blood flow measurements made across the aortic arch. The model is extended to several cardiac cycles to allow the simulation of a realistic ECG acquisition during MRI examination and the quality assessment of MHD suppression techniques. A comparison of two existing models is made with our new model and with an estimate of the MHD voltage observed during a real MRI scan. Results indicate a good agreement between our proposed model and the estimated MHD for most leads, although there are clearly some descrepencies with the observed signal which are likely to be due to remaining deficiencies in the model. However, the results demonstrate that our new model provides a closer approximation to observed MHD effects and a better depiction of the complexity of the MHD effect compared to the previously published models. The source code will be made freely available under and open source license to facilitate collaboration and allow more rapid development of more accurate models of the MHD effect. PMID:24761753

  4. CardioGuard: A Brassiere-Based Reliable ECG Monitoring Sensor System for Supporting Daily Smartphone Healthcare Applications

    PubMed Central

    Kwon, Sungjun; Kim, Jeehoon; Kang, Seungwoo; Lee, Youngki; Baek, Hyunjae

    2014-01-01

    Abstract We propose CardioGuard, a brassiere-based reliable electrocardiogram (ECG) monitoring sensor system, for supporting daily smartphone healthcare applications. It is designed to satisfy two key requirements for user-unobtrusive daily ECG monitoring: reliability of ECG sensing and usability of the sensor. The system is validated through extensive evaluations. The evaluation results showed that the CardioGuard sensor reliably measure the ECG during 12 representative daily activities including diverse movement levels; 89.53% of QRS peaks were detected on average. The questionnaire-based user study with 15 participants showed that the CardioGuard sensor was comfortable and unobtrusive. Additionally, the signal-to-noise ratio test and the washing durability test were conducted to show the high-quality sensing of the proposed sensor and its physical durability in practical use, respectively. PMID:25405527

  5. Fetal ECG Extraction from Abdominal Signals: A Review on Suppression of Fundamental Power Line Interference Component and Its Harmonics

    PubMed Central

    Ţarălungă, Dragoş-Daniel; Ungureanu, Georgeta-Mihaela; Gussi, Ilinca; Strungaru, Rodica; Wolf, Werner

    2014-01-01

    Interference of power line (PLI) (fundamental frequency and its harmonics) is usually present in biopotential measurements. Despite all countermeasures, the PLI still corrupts physiological signals, for example, electromyograms (EMG), electroencephalograms (EEG), and electrocardiograms (ECG). When analyzing the fetal ECG (fECG) recorded on the maternal abdomen, the PLI represents a particular strong noise component, being sometimes 10 times greater than the fECG signal, and thus impairing the extraction of any useful information regarding the fetal health state. Many signal processing methods for cancelling the PLI from biopotentials are available in the literature. In this review study, six different principles are analyzed and discussed, and their performance is evaluated on simulated data (three different scenarios), based on five quantitative performance indices. PMID:24660020

  6. A micropower dry-electrode ECG preamplifier.

    PubMed

    Burke, M J; Gleeson, D T

    2000-02-01

    This paper describes the development of a very low-power preamplifier intended for use in pasteless-electrode recording of the human electrocardiogram. The expected input signal range is 100 microV-10 mV from a lead-II electrode configuration. The amplifier provides a gain of 43 dB in a 3-dB bandwidth of 0.05 Hz-2 kHz with a defined high input impedance of 75 M omega. It uses a driven common electrode to enhance rejection of common-mode interfering signals, including low-frequency motion artifact, achieving a common-mode rejection ratio (CMRR) of better than 80 dB over its entire bandwidth. The gain and phase characteristics meet the recommendations of the American Heart Association, ensuring low distortion of the output ECG signal and making it suitable for clinical monitoring. The amplifier has a power consumption of 30 microW operating from a 3.3-V battery and is intended for use in small, lightweight, portable electrocardiographic equipment and heart-rate monitoring instrumentation.

  7. Electrocardiogram transmission - The state of the art.

    NASA Technical Reports Server (NTRS)

    Firstenberg, A.; Huston, S. W.; Olsen, D. E.; Hahn, P. M.

    1971-01-01

    A comparative analysis of available clinical EKG telemetry systems was conducted. Although present day electrocardiogram diagnosis requires a high degree of measurement accuracy, there exists wide variations in the performance characteristics of the various telemeters marketed today necessitating careful consideration of specifications prior to procurement. The authors have endeavored to provide the physicians with a clear understanding, in terms of the effects on the electrocardiogram, of the factors he must evaluate in order to ensure high fidelity EKG reproduction. A tabulation of comparative parameter values for each unit obtained from manufacturers' specifications and substantiated by standardized performance tests conducted in our laboratory is presented.

  8. Brugada ECG patterns in athletes.

    PubMed

    Chung, Eugene H

    2015-01-01

    Brugada syndrome is responsible for up to 4% of all sudden cardiac deaths worldwide and up to 20% of sudden cardiac deaths in patients with structurally normal hearts. Heterogeneity of repolarization and depolarization, particularly over the right ventricle and the outflow tract, is responsible for the arrhythmogenic substrate. The coved Type I ECG pattern is considered diagnostic of the syndrome but its prevalence is very low. Distinguishing between a saddle back Type 2 Brugada pattern and one of many "Brugada-like" patterns presents challenges especially in athletes. A number of criteria have been proposed to assess Brugada ECG patterns. Proper precordial ECG lead placement is paramount. This paper reviews Brugada syndrome, Brugada ECG patterns, and recently proposed criteria. Recommendations for evaluating a Brugada ECG pattern are provided.

  9. A Telesurveillance System With Automatic Electrocardiogram Interpretation Based on Support Vector Machine and Rule-Based Processing

    PubMed Central

    Lin, Ching-Miao; Lai, Feipei; Ho, Yi-Lwun; Hung, Chi-Sheng

    2015-01-01

    Background Telehealth care is a global trend affecting clinical practice around the world. To mitigate the workload of health professionals and provide ubiquitous health care, a comprehensive surveillance system with value-added services based on information technologies must be established. Objective We conducted this study to describe our proposed telesurveillance system designed for monitoring and classifying electrocardiogram (ECG) signals and to evaluate the performance of ECG classification. Methods We established a telesurveillance system with an automatic ECG interpretation mechanism. The system included: (1) automatic ECG signal transmission via telecommunication, (2) ECG signal processing, including noise elimination, peak estimation, and feature extraction, (3) automatic ECG interpretation based on the support vector machine (SVM) classifier and rule-based processing, and (4) display of ECG signals and their analyzed results. We analyzed 213,420 ECG signals that were diagnosed by cardiologists as the gold standard to verify the classification performance. Results In the clinical ECG database from the Telehealth Center of the National Taiwan University Hospital (NTUH), the experimental results showed that the ECG classifier yielded a specificity value of 96.66% for normal rhythm detection, a sensitivity value of 98.50% for disease recognition, and an accuracy value of 81.17% for noise detection. For the detection performance of specific diseases, the recognition model mainly generated sensitivity values of 92.70% for atrial fibrillation, 89.10% for pacemaker rhythm, 88.60% for atrial premature contraction, 72.98% for T-wave inversion, 62.21% for atrial flutter, and 62.57% for first-degree atrioventricular block. Conclusions Through connected telehealth care devices, the telesurveillance system, and the automatic ECG interpretation system, this mechanism was intentionally designed for continuous decision-making support and is reliable enough to reduce the

  10. Sparse electrocardiogram signals recovery based on solving a row echelon-like form of system.

    PubMed

    Cai, Pingmei; Wang, Guinan; Yu, Shiwei; Zhang, Hongjuan; Ding, Shuxue; Wu, Zikai

    2016-02-01

    The study of biology and medicine in a noise environment is an evolving direction in biological data analysis. Among these studies, analysis of electrocardiogram (ECG) signals in a noise environment is a challenging direction in personalized medicine. Due to its periodic characteristic, ECG signal can be roughly regarded as sparse biomedical signals. This study proposes a two-stage recovery algorithm for sparse biomedical signals in time domain. In the first stage, the concentration subspaces are found in advance. Then by exploiting these subspaces, the mixing matrix is estimated accurately. In the second stage, based on the number of active sources at each time point, the time points are divided into different layers. Next, by constructing some transformation matrices, these time points form a row echelon-like system. After that, the sources at each layer can be solved out explicitly by corresponding matrix operations. It is noting that all these operations are conducted under a weak sparse condition that the number of active sources is less than the number of observations. Experimental results show that the proposed method has a better performance for sparse ECG signal recovery problem. PMID:26816398

  11. The relationship between serum ferritin levels and electrocardiogram characteristics in acutely ill patients

    PubMed Central

    Laudanski, Krzysztof; Ali, Huma; Himmel, Andrew; Godula, Kasia; Stettmeier, Mary; Calvocoressi, Lisa

    2009-01-01

    BACKGROUND: Cardiac arrhythmias are common comorbidities among acutely ill patients admitted to hospitals. An abnormal iron metabolism may contribute to the abnormalities in the conduction and propagation of action potentials through myocardium. OBJECTIVE: To determine whether serum indexes of iron metabolism correlate with electrocardiogram (ECG) changes. METHODS: In the present retrospective, pilot chart review, serum levels of iron, ferritin, Na+, K+, Mg2+, Ca2+ and total iron-binding capacity in 77 hospitalized patients with acute illness were correlated with ECG variables. RESULTS: The serum ferritin level correlated strongly (r=0.49) with QT/QTs interval. There were three subjects with QT prolongation (longer than 450 ms) within the high serum ferritin (576 ng/mL or greater) group versus subjects with low ferritin. Multiple regression analysis showed that serum ferritin level and serum iron level contributed to the variance in the QT/QTs prolongation. No other correlation between the studied serum markers and ECG characteristics were found. CONCLUSION: The present study suggests that serum ferritin and iron levels affect the QT interval in a variety of medical conditions, possibly contributing to the emergence of fatal cardiac arrhythmias. PMID:20098576

  12. Electrocardiogram derived respiratory rate from QRS slopes and R-wave angle.

    PubMed

    Lázaro, Jesús; Alcaine, Alejandro; Romero, Daniel; Gil, Eduardo; Laguna, Pablo; Pueyo, Esther; Bailón, Raquel

    2014-10-01

    A method for estimating respiratory rate from electrocardiogram (ECG) signals is presented. It is based on QRS slopes and R-wave angle, which reflect respiration-induced beat morphology variations. The 12 standard leads, 3 leads from vectorcardiogram (VCG), and 2 additional non-standard leads derived from VCG loops were analyzed. The following series were studied as ECG derived respiration (EDR) signals: slope between the peak of Q and R waves, slope between the peak of R and S waves, and the R-wave angle. Information from several EDR signals was combined in order to increase the robustness of estimation. Evaluation is performed over two databases containing ECG and respiratory signals simultaneously recorded during two clinical tests with different characteristics: tilt test, representing abrupt cardiovascular changes, and stress test representing a highly non-stationary and noisy environment. A combination of QRS slopes and R-wave angle series derived from VCG leads obtained a respiratory rate estimation relative error of 0.50 ± 4.11% (measuring 99.84% of the time) for tilt test and 0.52 ± 8.99% (measuring 96.09% of the time) for stress test. These results outperform those obtained by other reported methods, both in tilt and stress testing.

  13. Signal-quality indices for the electrocardiogram and photoplethysmogram: derivation and applications to wireless monitoring.

    PubMed

    Orphanidou, Christina; Bonnici, Timothy; Charlton, Peter; Clifton, David; Vallance, David; Tarassenko, Lionel

    2015-05-01

    The identification of invalid data in recordings obtained using wearable sensors is of particular importance since data obtained from mobile patients is, in general, noisier than data obtained from nonmobile patients. In this paper, we present a signal quality index (SQI), which is intended to assess whether reliable heart rates (HRs) can be obtained from electrocardiogram (ECG) and photoplethysmogram (PPG) signals collected using wearable sensors. The algorithms were validated on manually labeled data. Sensitivities and specificities of 94% and 97% were achieved for the ECG and 91% and 95% for the PPG. Additionally, we propose two applications of the SQI. First, we demonstrate that, by using the SQI as a trigger for a power-saving strategy, it is possible to reduce the recording time by up to 94% for the ECG and 93% for the PPG with only minimal loss of valid vital-sign data. Second, we demonstrate how an SQI can be used to reduce the error in the estimation of respiratory rate (RR) from the PPG. The performance of the two applications was assessed on data collected from a clinical study on hospital patients who were able to walk unassisted.

  14. Direct reading of electrocardiograms and respiration rates

    NASA Technical Reports Server (NTRS)

    Wise, J. P.

    1969-01-01

    Technique for reading heart and respiration rates is more accurate and direct than the previous method. Index of a plastic calibrated card is aligned with a point on the electrocardiogram. Complexes are counted as indicated on the card and heart or respiration rate is read directly from the appropriate scale.

  15. Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals.

    PubMed

    Elhaj, Fatin A; Salim, Naomie; Harris, Arief R; Swee, Tan Tian; Ahmed, Taqwa

    2016-04-01

    Arrhythmia is a cardiac condition caused by abnormal electrical activity of the heart, and an electrocardiogram (ECG) is the non-invasive method used to detect arrhythmias or heart abnormalities. Due to the presence of noise, the non-stationary nature of the ECG signal (i.e. the changing morphology of the ECG signal with respect to time) and the irregularity of the heartbeat, physicians face difficulties in the diagnosis of arrhythmias. The computer-aided analysis of ECG results assists physicians to detect cardiovascular diseases. The development of many existing arrhythmia systems has depended on the findings from linear experiments on ECG data which achieve high performance on noise-free data. However, nonlinear experiments characterize the ECG signal more effectively sense, extract hidden information in the ECG signal, and achieve good performance under noisy conditions. This paper investigates the representation ability of linear and nonlinear features and proposes a combination of such features in order to improve the classification of ECG data. In this study, five types of beat classes of arrhythmia as recommended by the Association for Advancement of Medical Instrumentation are analyzed: non-ectopic beats (N), supra-ventricular ectopic beats (S), ventricular ectopic beats (V), fusion beats (F) and unclassifiable and paced beats (U). The characterization ability of nonlinear features such as high order statistics and cumulants and nonlinear feature reduction methods such as independent component analysis are combined with linear features, namely, the principal component analysis of discrete wavelet transform coefficients. The features are tested for their ability to differentiate different classes of data using different classifiers, namely, the support vector machine and neural network methods with tenfold cross-validation. Our proposed method is able to classify the N, S, V, F and U arrhythmia classes with high accuracy (98.91%) using a combined support

  16. Diagnostic ECG classification based on neural networks.

    PubMed

    Bortolan, G; Willems, J L

    1993-01-01

    This study illustrates the use of the neural network approach in the problem of diagnostic classification of resting 12-lead electrocardiograms. A large electrocardiographic library (the CORDA database established at the University of Leuven, Belgium) has been utilized in this study, whose classification is validated by electrocardiographic-independent clinical data. In particular, a subset of 3,253 electrocardiographic signals with single diseases has been selected. Seven diagnostic classes have been considered: normal, left, right, and biventricular hypertrophy, and anterior, inferior, and combined myocardial infarction. The basic architecture used is a feed-forward neural network and the backpropagation algorithm for the training phase. Sensitivity, specificity, total accuracy, and partial accuracy are the indices used for testing and comparing the results with classical methodologies. In order to validate this approach, the accuracy of two statistical models (linear discriminant analysis and logistic discriminant analysis) tuned on the same dataset have been taken as the reference point. Several nets have been trained, either adjusting some components of the architecture of the networks, considering subsets and clusters of the original learning set, or combining different neural networks. The results have confirmed the potentiality and good performance of the connectionist approach when compared with classical methodologies.

  17. Adaptive independent component analysis to analyze electrocardiograms

    NASA Astrophysics Data System (ADS)

    Yim, Seong-Bin; Szu, Harold H.

    2001-03-01

    In this work, we apply adaptive version independent component analysis (ADAPTIVE ICA) to the nonlinear measurement of electro-cardio-graphic (ECG) signals for potential detection of abnormal conditions in the heart. In principle, unsupervised ADAPTIVE ICA neural networks can demix the components of measured ECG signals. However, the nonlinear pre-amplification and post measurement processing make the linear ADAPTIVE ICA model no longer valid. This is possible because of a proposed adaptive rectification pre-processing is used to linearize the preamplifier of ECG, and then linear ADAPTIVE ICA is used in iterative manner until the outputs having their own stable Kurtosis. We call such a new approach adaptive ADAPTIVE ICA. Each component may correspond to individual heart function, either normal or abnormal. Adaptive ADAPTIVE ICA neural networks have the potential to make abnormal components more apparent, even when they are masked by normal components in the original measured signals. This is particularly important for diagnosis well in advance of the actual onset of heart attack, in which abnormalities in the original measured ECG signals may be difficult to detect. This is the first known work that applies Adaptive ADAPTIVE ICA to ECG signals beyond noise extraction, to the detection of abnormal heart function.

  18. Acquisition of Visual Perceptual Skills from Worked Examples: Learning to Interpret Electrocardiograms (ECGs)

    ERIC Educational Resources Information Center

    van den Berge, Kees; van Gog, Tamara; Mamede, Silvia; Schmidt, Henk G.; van Saase, Jan L. C. M.; Rikers, Remy M. J. P.

    2013-01-01

    Research has shown that for acquiring problem-solving skills, instruction consisting of studying worked examples is more effective and efficient for novice learners than instruction consisting of problem-solving. This study investigated whether worked examples would also be a useful instructional format for the acquisition of visual perceptual…

  19. Effects of thyroid hormone deficiency on electrocardiogram findings of congenitally hypothyroid neonates.

    PubMed

    Asami, T; Suzuki, H; Yazaki, S; Sato, S; Uchiyama, M

    2001-08-01

    Hypothyroid status is believed to cause various metabolic changes in infants. However, it is interesting that even severely hypothyroid neonates, detected during mass neonatal screening, rarely show bradycardia, hypothermia, or inactivity. To study cardiac functions of screen-detected neonates with congenital hypothyroidism (CH), we recorded the electrocardiograms (ECG) of 53 screen-detected CH neonates before levothyroxine (LT4) replacement therapy, and 15 age-matched normal neonates for controls. The 53 CH neonates were divided into two groups according to initial serum thyroid hormone levels: a mildly hypothyroid group (n = 37), serum thyroid-stimulating hormone (TSH) less than 100 microIU/mL and free thyroxine (FT4) 0.6 ng/dl or more; and a severely hypothyroid group (n = 16), TSH 100 microIU/mL or more and FT4 less than 0.6 ng/dL. TSH, FT4, and other blood chemicals were measured on an autoanalyzer (Hitachi 7170). After blood sampling, the ECG was recorded during induced sleep by oral administration of triclofos sodium syrup. ECG parameters, including HR, PR, QRS, QT time and corrected QT time (QTc) were automatically obtained, using an auto-ECG analyzing system. The following results were obtained. No CH patients showed abnormal ECG findings. There was no significant difference of the mean heart rates (HRs) between the mildly hypothyroid (147.5 +/- 16.3 beats per minute) and the control group (148.3 +/- 12.1 beats per minute). The mean HR in the severely hypothyroid group (134.0 +/- 17.9 beats per minute, p = 0.007) was significantly low compared with the normal control group. However, all values were within normal ranges. QTc in the severely hypothyroid group (0.414 +/- 0.015, p = 0.033) was significantly shorter than in the control group (0.440 +/- 0.052). No statistical differences of PR, QRS, and QT time were noted among the three groups. All ECG parameters were within normal ranges. HR positively correlated with FT4 and log (FT4), and negatively with TSH

  20. Deployment of an Advanced Electrocardiographic Analysis (A-ECG) to Detect Cardiovascular Risk in Career Firefighters

    NASA Technical Reports Server (NTRS)

    Dolezal, B. A.; Storer, T. W.; Abrazado, M.; Watne, R.; Schlegel, T. T.; Batalin, M.; Kaiser, W.; Smith, D. L.; Cooper, C. B.

    2011-01-01

    INTRODUCTION: Sudden cardiac death is the leading cause of line of duty death among firefighters, accounting for approximately 45% of fatalities annually. Firefighters perform strenuous muscular work while wearing heavy, encapsulating personal protective equipment in high ambient temperatures, under chaotic and emotionally stressful conditions. These factors can precipitate sudden cardiac events like myocardial infarction, serious dysrhythmias, or cerebrovascular accidents in firefighters with underlying cardiovascular disease. PURPOSE: The purpose of this study was to deploy and then evaluate the contribution of resting advanced ECG (A-ECG) in addition to other screening tools (family history, lipid profiles, and cardiopulmonary exercise tests, XT) in assessment of an individual fs cardiac risk profile. METHODS: Forty-four career firefighters were recruited to perform comprehensive baseline assessments including tests of aerobic performance, fasting lipids and glucose. Five-min resting 12-lead A-ECGs were obtained in a subset of firefighters (n=21) and transmitted over a secure networked system to a NASA physician collaborator. Using myocardial perfusion and other imaging as the gold standard, A-ECG scoring has been proven useful in accurately identifying a number of cardiac pathologies including coronary artery disease (CAD), left ventricular hypertrophy, hypertrophic cardiomyopathy, and non-ischemic and ischemic cardiomyopathy. RESULTS: Subjects f mean (SD) age was 43 (8) years, weight 91 (13) kg, and BMI 28 (3) kg/m2. Fifty-one percent of subjects had .3 cardiovascular risk factors. One subject had ST depression on XT ECG, at least one positive A-ECG score for CAD, and documented CAD based on cardiology referral. While all other subjects, including those with fewer risk factors, higher aerobic fitness, and normal exercise ECGs, were classified as healthy by A-ECG, there was no trend for association between risk factors and any of 20 A-ECG parameters in the

  1. Can Functional Cardiac Age be Predicted from ECG in a Normal Healthy Population

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd; Starc, Vito; Leban, Manja; Sinigoj, Petra; Vrhovec, Milos

    2011-01-01

    In a normal healthy population, we desired to determine the most age-dependent conventional and advanced ECG parameters. We hypothesized that changes in several ECG parameters might correlate with age and together reliably characterize the functional age of the heart. Methods: An initial study population of 313 apparently healthy subjects was ultimately reduced to 148 subjects (74 men, 84 women, in the range from 10 to 75 years of age) after exclusion criteria. In all subjects, ECG recordings (resting 5-minute 12-lead high frequency ECG) were evaluated via custom software programs to calculate up to 85 different conventional and advanced ECG parameters including beat-to-beat QT and RR variability, waveform complexity, and signal-averaged, high-frequency and spatial/spatiotemporal ECG parameters. The prediction of functional age was evaluated by multiple linear regression analysis using the best 5 univariate predictors. Results: Ignoring what were ultimately small differences between males and females, the functional age was found to be predicted (R2= 0.69, P < 0.001) from a linear combination of 5 independent variables: QRS elevation in the frontal plane (p<0.001), a new repolarization parameter QTcorr (p<0.001), mean high frequency QRS amplitude (p=0.009), the variability parameter % VLF of RRV (p=0.021) and the P-wave width (p=0.10). Here, QTcorr represents the correlation between the calculated QT and the measured QT signal. Conclusions: In apparently healthy subjects with normal conventional ECGs, functional cardiac age can be estimated by multiple linear regression analysis of mostly advanced ECG results. Because some parameters in the regression formula, such as QTcorr, high frequency QRS amplitude and P-wave width also change with disease in the same direction as with increased age, increased functional age of the heart may reflect subtle age-related pathologies in cardiac electrical function that are usually hidden on conventional ECG.

  2. Noninvasive Fetal ECG analysis

    PubMed Central

    Clifford, Gari D.; Silva, Ikaro; Behar, Joachim; Moody, George B.

    2014-01-01

    Despite the important advances achieved in the field of adult electrocardiography signal processing, the analysis of the non-invasive fetal electrocardiogram (NI-FECG) remains a challenge. Currently no gold standard database exists which provides labelled FECG QRS complexes (and other morphological parameters), and publications rely either on proprietary databases or a very limited set of data recorded from few (or more often, just one) individuals. The PhysioNet/Computing in Cardiology Challenge 2013 enables to tackle some of these limitations by releasing a set of NI-FECG data publicly to the scientific community in order to evaluate signal processing techniques for NI-FECG extraction. The Challenge aim was to encourage development of accurate algorithms for locating QRS complexes and estimating the QT interval in noninvasive FECG signals. Using carefully reviewed reference QRS annotations and QT intervals as a gold standard, based on simultaneous direct FECG when possible, the Challenge was designed to measure and compare the performance of participants’ algorithms objectively. Multiple challenge events were designed to test basic FHR estimation accuracy, as well as accuracy in measurement of inter-beat (RR) and QT intervals needed as a basis for derivation of other FECG features. This editorial reviews the background issues, the design of the Challenge, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. PMID:25071093

  3. Microcontroller-based underwater acoustic ECG telemetry system.

    PubMed

    Istepanian, R S; Woodward, B

    1997-06-01

    This paper presents a microcontroller-based underwater acoustic telemetry system for digital transmission of the electrocardiogram (ECG). The system is designed for the real time, through-water transmission of data representing any parameter, and it was used initially for transmitting in multiplexed format the heart rate, breathing rate and depth of a diver using self-contained underwater breathing apparatus (SCUBA). Here, it is used to monitor cardiovascular reflexes during diving and swimming. The programmable capability of the system provides an effective solution to the problem of transmitting data in the presence of multipath interference. An important feature of the paper is a comparative performance analysis of two encoding methods, Pulse Code Modulation (PCM) and Pulse Position Modulation (PPM).

  4. Modeling left and right atrial contributions to the ECG: A dipole-current source approach.

    PubMed

    Jacquemet, Vincent

    2015-10-01

    This paper presents the mathematical formulation, the numerical validation and several illustrations of a forward-modeling approach based on dipole-current sources to compute the contribution of a part of the heart to the electrocardiogram (ECG). Clinically relevant applications include identifying in the ECG the contributions from the right and the left atrium. In a Courtemanche-based monodomain computer model of the atria and torso, 1000 dipoles distributed throughout the atrial mid-myocardium are found to be sufficient to reproduce body surface potential maps with a relative error <1% during both sinus rhythm and atrial fibrillation. When the boundary element method is applied to solve the forward problem, this approach enables fast offline computation of the ECG contribution of any anatomical part of the atria by applying the principle of superposition to the dipole sources. In the presence of a right-left activation delay (sinus rhythm), pulmonary vein isolation (sinus rhythm) or left-right differences in refractory period (atrial fibrillation), the decomposition of the ECG is shown to help interpret ECG morphology in relation to the atrial substrate. These tools provide a theoretical basis for a deeper understanding of the genesis of the P wave or fibrillatory waves in normal and pathological cases.

  5. The initial electrocardiogram in patients seen by a mobile coronary care unit.

    PubMed

    Dalzell, G W; Purvis, J; Adgey, A A

    1991-03-01

    The advent of thrombolytic therapy for patients with suspected acute myocardial infarction has highlighted the importance of the initial electrocardiogram (ECG) in decision making. Thus we analysed the initial ECGs of 94 consecutive cases with suspected myocardial infarction who were seen within six hours after the onset of chest pain by a mobile coronary care unit. The study included 91 patients (three patients admitted twice) (61 male), aged 27-83 years (mean 60.5). Median time from onset of chest pain to arrival of the mobile coronary care unit was 75 minutes (range 15-345), and mean mobile coronary care unit response time was 12.3 +/- 7 (SD) minutes (range 5-45). The majority of cases (65 of 94, 69.1 per cent) were seen within two hours of the onset of symptoms. A final diagnosis of myocardial infarction was made in 48 of 94 (51.1 per cent) cases; 38 had unstable angina and eight other diagnoses. Of the 48 with myocardial infarction the initial ECG showed ST segment elevation in 37, ST depression and or T wave inversion in six, Q waves only in three and left bundle branch block in two. No patient with an initially normal ECG had a myocardial infarction. Thrombolytic therapy was given out of hospital to 33 of 38 patients with ST segment elevation. In seven patients with ST elevation (median delay time to intensive care 60 minutes), rapid resolution of ST segment elevation occurred following thrombolytic therapy and there was no significant elevation of cardiac enzymes, suggesting that the infarct had been aborted.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2047517

  6. Electrocardiogram, heart movement and heart rate in the awake gecko (Hemidactylus mabouia).

    PubMed

    Germer, Carina M; Tomaz, Juliana M; Carvalho, Ana F; Bassani, Rosana A; Bassani, José W M

    2015-01-01

    The electrocardiogram (ECG) is the simplest and most effective non-invasive method to assess the electrical activity of the heart and to obtain information on the heart rate (HR) and rhythm. Because information on the HR of very small reptiles (body mass <10 g) is still scarce in the literature, in the present work we describe a procedure for recording the ECG in non-anesthetized geckos (Hemidactylus mabouia, Moreau de Jonnès, 1818) under different conditions, namely manual restraint (MR), spontaneous tonic immobility (TI), and in the non-restrained condition (NR). In the gecko ECG, the P, QRS and T waves were clearly distinguishable. The HR was 2.83 ± 0.02 Hz under MR, which was significantly greater (p < 0.001) than the HR under the TI (1.65 ± 0.09 Hz) and NR (1.60 ± 0.10 Hz) conditions. Spontaneously beating isolated gecko hearts contracted at 0.84 ± 0.03 Hz. The in vitro beating rate was affected in a concentration-dependent fashion by adrenoceptor stimulation with noradrenaline, as well as by the muscarinic cholinergic agonist carbachol, which produced significant positive and negative chronotropic effects, respectively (p < 0.001). To our knowledge, this is the first report on the ECG morphology and HR values in geckos, particularly under TI. The methodology and instrumentation developed here are useful for non-invasive in vivo physiological and pharmacological studies in small reptiles without the need of physical restraint or anesthesia.

  7. Effects of 900 MHz electromagnetic field emitted by cellular phones on electrocardiograms of guinea pigs.

    PubMed

    Meral, I; Tekintangac, Y; Demir, H

    2014-02-01

    This study was carried out to determine the effects of electromagnetic field (EMF) emitted by cellular phones (CPs) on electrocardiograms (ECGs) of guinea pigs. A total of 30 healthy guinea pigs weighing 500-800 g were used. After 1 week of adaptation period, animals were randomly divided into two groups: control group (n = 10) and EMF-exposed group (n = 20). Control guinea pigs were housed in a separate room without exposing them to EMFs of CPs. Animals in second group were exposed to 890-915 MHz EMF (217 Hz of pulse rate, 2 W of maximum peak power and 0.95 wt kg(-1) of specific absorption rate) for 12 h day(-1) (11 h 45 min stand-by and 15 min speaking mode) for 30 days. ECGs of guinea pigs in both the groups were recorded by a direct writing electrocardiograph at the beginning and 10th, 20th and 30th days of the experiment. All ECGs were standardized at 1 mV = 10 mm and with a chart speed of 50 mm sec(-1). Leads I, II, III, lead augmented vector right (aVR), lead augmented vector left (aVL) and lead augmented vector foot (aVF) were recorded. The durations and amplitudes of waves on the trace were measured in lead II. The data were expressed as mean with SEM. It was found that 12 h day(-1) EMF exposure for 30 days did not have any significant effects on ECG findings of guinea pigs. However, this issue needed to be further investigated in a variety of perspectives, such as longer duration of exposure to be able to elucidate the effects of mobile phone-induced EMFs on cardiovascular functions.

  8. The risk factors and prevention of cardiovascular disease: the importance of electrocardiogram in the diagnosis and treatment of acute coronary syndrome.

    PubMed

    Rosiek, Anna; Leksowski, Krzysztof

    2016-01-01

    Acute coronary syndrome is a leading cause of emergency medical treatment and hospitalization in Poland. High-speed electrocardiogram (ECG) has shown good accuracy of the initial diagnosis and of the final diagnosis in treated cardiac patients. Initial diagnosis and definitive diagnosis were analyzed statistically (P<0.0001). Although much is said about the prevention of sudden death in heart failure, the elimination of risk factors health care in Poland does not pay due attention to the need for early diagnosis and ECG analysis (at the stage of prevention). This article presents the inclusion of ECG in the prevention process and shows that it allows for early detection of cardiovascular diseases. In Poland, ST-segment elevation myocardial infarction patients are identified in the ambulance that reduces time to door-to-balloon. PMID:27540297

  9. Validity of computational hemodynamics in human arteries based on 3D time-of-flight MR angiography and 2D electrocardiogram gated phase contrast images

    NASA Astrophysics Data System (ADS)

    Yu, Huidan (Whitney); Chen, Xi; Chen, Rou; Wang, Zhiqiang; Lin, Chen; Kralik, Stephen; Zhao, Ye

    2015-11-01

    In this work, we demonstrate the validity of 4-D patient-specific computational hemodynamics (PSCH) based on 3-D time-of-flight (TOF) MR angiography (MRA) and 2-D electrocardiogram (ECG) gated phase contrast (PC) images. The mesoscale lattice Boltzmann method (LBM) is employed to segment morphological arterial geometry from TOF MRA, to extract velocity profiles from ECG PC images, and to simulate fluid dynamics on a unified GPU accelerated computational platform. Two healthy volunteers are recruited to participate in the study. For each volunteer, a 3-D high resolution TOF MRA image and 10 2-D ECG gated PC images are acquired to provide the morphological geometry and the time-varying flow velocity profiles for necessary inputs of the PSCH. Validation results will be presented through comparisons of LBM vs. 4D Flow Software for flow rates and LBM simulation vs. MRA measurement for blood flow velocity maps. Indiana University Health (IUH) Values Fund.

  10. The risk factors and prevention of cardiovascular disease: the importance of electrocardiogram in the diagnosis and treatment of acute coronary syndrome

    PubMed Central

    Rosiek, Anna; Leksowski, Krzysztof

    2016-01-01

    Acute coronary syndrome is a leading cause of emergency medical treatment and hospitalization in Poland. High-speed electrocardiogram (ECG) has shown good accuracy of the initial diagnosis and of the final diagnosis in treated cardiac patients. Initial diagnosis and definitive diagnosis were analyzed statistically (P<0.0001). Although much is said about the prevention of sudden death in heart failure, the elimination of risk factors health care in Poland does not pay due attention to the need for early diagnosis and ECG analysis (at the stage of prevention). This article presents the inclusion of ECG in the prevention process and shows that it allows for early detection of cardiovascular diseases. In Poland, ST-segment elevation myocardial infarction patients are identified in the ambulance that reduces time to door-to-balloon. PMID:27540297

  11. Predictable and reliable ECG monitoring over IEEE 802.11 WLANs within a hospital.

    PubMed

    Park, Juyoung; Kang, Kyungtae

    2014-09-01

    Telecardiology provides mobility for patients who require constant electrocardiogram (ECG) monitoring. However, its safety is dependent on the predictability and robustness of data delivery, which must overcome errors in the wireless channel through which the ECG data are transmitted. We report here a framework that can be used to gauge the applicability of IEEE 802.11 wireless local area network (WLAN) technology to ECG monitoring systems in terms of delay constraints and transmission reliability. For this purpose, a medical-grade WLAN architecture achieved predictable delay through the combination of a medium access control mechanism based on the point coordination function provided by IEEE 802.11 and an error control scheme based on Reed-Solomon coding and block interleaving. The size of the jitter buffer needed was determined by this architecture to avoid service dropout caused by buffer underrun, through analysis of variations in transmission delay. Finally, we assessed this architecture in terms of service latency and reliability by modeling the transmission of uncompressed two-lead electrocardiogram data from the MIT-BIH Arrhythmia Database and highlight the applicability of this wireless technology to telecardiology.

  12. Predictable and reliable ECG monitoring over IEEE 802.11 WLANs within a hospital.

    PubMed

    Park, Juyoung; Kang, Kyungtae

    2014-09-01

    Telecardiology provides mobility for patients who require constant electrocardiogram (ECG) monitoring. However, its safety is dependent on the predictability and robustness of data delivery, which must overcome errors in the wireless channel through which the ECG data are transmitted. We report here a framework that can be used to gauge the applicability of IEEE 802.11 wireless local area network (WLAN) technology to ECG monitoring systems in terms of delay constraints and transmission reliability. For this purpose, a medical-grade WLAN architecture achieved predictable delay through the combination of a medium access control mechanism based on the point coordination function provided by IEEE 802.11 and an error control scheme based on Reed-Solomon coding and block interleaving. The size of the jitter buffer needed was determined by this architecture to avoid service dropout caused by buffer underrun, through analysis of variations in transmission delay. Finally, we assessed this architecture in terms of service latency and reliability by modeling the transmission of uncompressed two-lead electrocardiogram data from the MIT-BIH Arrhythmia Database and highlight the applicability of this wireless technology to telecardiology. PMID:25083792

  13. The centennial of the Einthoven electrocardiogram.

    PubMed

    Kligfield, Paul

    2002-01-01

    Recording of the electrocardiogram by string galvanometer evolved a century ago from wide-ranging advances in physiology, physics, and engineering. Although body surface recordings had been obtained prior to the work of Willem Einthoven, his ingenuity in mathematically correcting capillary electrometer tracings and incorporating recent advances in electromagnetism, recording technology, optics, and quartz chemistry into the new instrument led to a fundamental tool for the investigation of the heart. For his work, Einthoven received the Nobel Prize. PMID:12539109

  14. Subband higher-order statistics and cross-correlation for heartbeat type recognition based on two-lead electrocardiogram.

    PubMed

    Yu, Sung-Nien; Liu, Fan-Tsen

    2014-01-01

    Regular electrocardiogram beat classification system usually based on single lead ECG signal. This study designated to add a second lead of ECG signal to the system and apply higher-order statistics and inter-lead cross-correlation features to study the influence of the second lead to the recognition rates and noise-tolerance of the classifier. Discrete wavelet transformation is employed to decompose the ECG signals into different subband components and higher order statistics is recruited to characterize the ECG signals as an attempt to elevate the accuracy and noise-resistibility of heartbeat discrimination. A feed-forward back-propagation neural network (FFBNN) is employed as classifier. When compared with the system that uses only one lead, the second lead raises the recognition rate from 97.74% to 98.25%. We also study the ability of the two-lead system in resisting different levels of white Gaussian noise. More than 97.8% accuracy can be retained with the two-lead system even when the SNR decreases to 10 dB. PMID:25569892

  15. Transform Domain Robust Variable Step Size Griffiths' Adaptive Algorithm for Noise Cancellation in ECG

    NASA Astrophysics Data System (ADS)

    Hegde, Veena; Deekshit, Ravishankar; Satyanarayana, P. S.

    2011-12-01

    The electrocardiogram (ECG) is widely used for diagnosis of heart diseases. Good quality of ECG is utilized by physicians for interpretation and identification of physiological and pathological phenomena. However, in real situations, ECG recordings are often corrupted by artifacts or noise. Noise severely limits the utility of the recorded ECG and thus needs to be removed, for better clinical evaluation. In the present paper a new noise cancellation technique is proposed for removal of random noise like muscle artifact from ECG signal. A transform domain robust variable step size Griffiths' LMS algorithm (TVGLMS) is proposed for noise cancellation. For the TVGLMS, the robust variable step size has been achieved by using the Griffiths' gradient which uses cross-correlation between the desired signal contaminated with observation or random noise and the input. The algorithm is discrete cosine transform (DCT) based and uses symmetric property of the signal to represent the signal in frequency domain with lesser number of frequency coefficients when compared to that of discrete Fourier transform (DFT). The algorithm is implemented for adaptive line enhancer (ALE) filter which extracts the ECG signal in a noisy environment using LMS filter adaptation. The proposed algorithm is found to have better convergence error/misadjustment when compared to that of ordinary transform domain LMS (TLMS) algorithm, both in the presence of white/colored observation noise. The reduction in convergence error achieved by the new algorithm with desired signal decomposition is found to be lower than that obtained without decomposition. The experimental results indicate that the proposed method is better than traditional adaptive filter using LMS algorithm in the aspects of retaining geometrical characteristics of ECG signal.

  16. Accuracy of localization of acute myocardial infarction by 12 lead electrocardiography

    SciTech Connect

    Yasuda, T.; Ribeiro, L.G.; Holman, B.L.; Alpert, J.S.; Maroko, P.R.

    1982-04-01

    Until recently, ECG accuracy in localizing acute myocardial infarction (AMI) could be assessed only by comparing the ECGs with autopsy findings. This approach, however, preselected patients, including only those who died. It is possible that this postmortem group of patients would be different from the whole population of patients with AMI. Myocardial imaging with /sup 99/mTc-pyrophosphate offers the advantage of directly localizing the region of injured myocardium in the acute phase of AMI. In 34 patients with confirmed AMI and focal uptake of /sup 99/mTc-pyrophosphate, serial ECGs were obtained and interpreted by two independent observers. The sensitivity and specificity of serial ECGs in determining the location of AMI in the five left ventricular (LV) wall segments were determined: (1) in the anterior wall sensitivity was 86.7% and specificity was 89.5%; (2) in the lateral wall sensitivity was 73.7% and specificity was 80.0%; (3) in the high lateral wall sensitivity was 80.0% and specificity was 87.5%; (4) in the inferior wall sensitivity was 87.5% and specificity was 100%; (5) in the true posterior wall sensitivity was 83.3% and specificity was 86.4%. Overall, in the 170 LV wall segments (five per patient) examined, scans localized with a sensitivity of 81.9% and a specificity of 88.8%. After four patients with LBBB were excluded, sensitivity increased to 87.1%. Overall, localization of AMI by serial ECG was accurate in 85.9% of the 34 patients included in the study.

  17. The future of remote ECG monitoring systems.

    PubMed

    Guo, Shu-Li; Han, Li-Na; Liu, Hong-Wei; Si, Quan-Jin; Kong, De-Feng; Guo, Fu-Su

    2016-09-01

    Remote ECG monitoring systems are becoming commonplace medical devices for remote heart monitoring. In recent years, remote ECG monitoring systems have been applied in the monitoring of various kinds of heart diseases, and the quality of the transmission and reception of the ECG signals during remote process kept advancing. However, there remains accompanying challenges. This report focuses on the three components of the remote ECG monitoring system: patient (the end user), the doctor workstation, and the remote server, reviewing and evaluating the imminent challenges on the wearable systems, packet loss in remote transmission, portable ECG monitoring system, patient ECG data collection system, and ECG signals transmission including real-time processing ST segment, R wave, RR interval and QRS wave, etc. This paper tries to clarify the future developmental strategies of the ECG remote monitoring, which can be helpful in guiding the research and development of remote ECG monitoring. PMID:27582770

  18. The future of remote ECG monitoring systems

    PubMed Central

    Guo, Shu-Li; Han, Li-Na; Liu, Hong-Wei; Si, Quan-Jin; Kong, De-Feng; Guo, Fu-Su

    2016-01-01

    Remote ECG monitoring systems are becoming commonplace medical devices for remote heart monitoring. In recent years, remote ECG monitoring systems have been applied in the monitoring of various kinds of heart diseases, and the quality of the transmission and reception of the ECG signals during remote process kept advancing. However, there remains accompanying challenges. This report focuses on the three components of the remote ECG monitoring system: patient (the end user), the doctor workstation, and the remote server, reviewing and evaluating the imminent challenges on the wearable systems, packet loss in remote transmission, portable ECG monitoring system, patient ECG data collection system, and ECG signals transmission including real-time processing ST segment, R wave, RR interval and QRS wave, etc. This paper tries to clarify the future developmental strategies of the ECG remote monitoring, which can be helpful in guiding the research and development of remote ECG monitoring. PMID:27582770

  19. A low computational complexity algorithm for ECG signal compression.

    PubMed

    Blanco-Velasco, Manuel; Cruz-Roldán, Fernando; López-Ferreras, Francisco; Bravo-Santos, Angel; Martínez-Muñoz, Damián

    2004-09-01

    In this work, a filter bank-based algorithm for electrocardiogram (ECG) signals compression is proposed. The new coder consists of three different stages. In the first one--the subband decomposition stage--we compare the performance of a nearly perfect reconstruction (N-PR) cosine-modulated filter bank with the wavelet packet (WP) technique. Both schemes use the same coding algorithm, thus permitting an effective comparison. The target of the comparison is the quality of the reconstructed signal, which must remain within predetermined accuracy limits. We employ the most widely used quality criterion for the compressed ECG: the percentage root-mean-square difference (PRD). It is complemented by means of the maximum amplitude error (MAX). The tests have been done for the 12 principal cardiac leads, and the amount of compression is evaluated by means of the mean number of bits per sample (MBPS) and the compression ratio (CR). The implementation cost for both the filter bank and the WP technique has also been studied. The results show that the N-PR cosine-modulated filter bank method outperforms the WP technique in both quality and efficiency. PMID:15271283

  20. A mobile device system for early warning of ECG anomalies.

    PubMed

    Szczepański, Adam; Saeed, Khalid

    2014-01-01

    With the rapid increase in computational power of mobile devices the amount of ambient intelligence-based smart environment systems has increased greatly in recent years. A proposition of such a solution is described in this paper, namely real time monitoring of an electrocardiogram (ECG) signal during everyday activities for identification of life threatening situations. The paper, being both research and review, describes previous work of the authors, current state of the art in the context of the authors' work and the proposed aforementioned system. Although parts of the solution were described in earlier publications of the authors, the whole concept is presented completely for the first time along with the prototype implementation on mobile device-a Windows 8 tablet with Modern UI. The system has three main purposes. The first goal is the detection of sudden rapid cardiac malfunctions and informing the people in the patient's surroundings, family and friends and the nearest emergency station about the deteriorating health of the monitored person. The second goal is a monitoring of ECG signals under non-clinical conditions to detect anomalies that are typically not found during diagnostic tests. The third goal is to register and analyze repeatable, long-term disturbances in the regular signal and finding their patterns. PMID:24955946

  1. A Mobile Device System for Early Warning of ECG Anomalies

    PubMed Central

    Szczepański, Adam; Saeed, Khalid

    2014-01-01

    With the rapid increase in computational power of mobile devices the amount of ambient intelligence-based smart environment systems has increased greatly in recent years. A proposition of such a solution is described in this paper, namely real time monitoring of an electrocardiogram (ECG) signal during everyday activities for identification of life threatening situations. The paper, being both research and review, describes previous work of the authors, current state of the art in the context of the authors' work and the proposed aforementioned system. Although parts of the solution were described in earlier publications of the authors, the whole concept is presented completely for the first time along with the prototype implementation on mobile device—a Windows 8 tablet with Modern UI. The system has three main purposes. The first goal is the detection of sudden rapid cardiac malfunctions and informing the people in the patient's surroundings, family and friends and the nearest emergency station about the deteriorating health of the monitored person. The second goal is a monitoring of ECG signals under non-clinical conditions to detect anomalies that are typically not found during diagnostic tests. The third goal is to register and analyze repeatable, long-term disturbances in the regular signal and finding their patterns. PMID:24955946

  2. Comparative analysis of diagnostic 12-lead electrocardiography and 3-dimensional noninvasive mapping.

    PubMed

    Leong, Kevin Ming Wei; Lim, Phang Boon; Kanagaratnam, Prapa

    2015-03-01

    The clinical utility of noninvasive electrocardiographic imaging has been demonstrated in a variety of conditions. It has recently been shown to have superior predictive accuracy and higher clinical value than validated 12-lead electrogram algorithms in the localization of arrhythmias arising from the ventricular outflow tract, and displays similar potential in other conditions.

  3. Deployment of an Advanced Electrocardiographic Analysis (A-ECG) to Detect Cardiovascular Risk in Career Firefighters

    NASA Technical Reports Server (NTRS)

    Dolezal, B. A.; Storer, T. W.; Abrazado, M.; Watne, R.; Schlegel, T. T.; Batalin, M.; Kaiser, W.; Smith, D. L.; Cooper, C. B.

    2011-01-01

    INTRODUCTION Sudden cardiac death is the leading cause of line of duty death among firefighters, accounting for approximately 45% of fatalities annually. Firefighters perform strenuous muscular work while wearing heavy, encapsulating personal protective equipment in high ambient temperatures, under chaotic and emotionally stressful conditions. These factors can precipitate sudden cardiac events like myocardial infarction, serious dysrhythmias, or cerebrovascular accidents in firefighters with underlying cardiovascular disease. Screening for cardiovascular risk factors is recommended but not always followed in this population. PHASER is a project charged with identifying and prioritizing risk factors in emergency responders. We have deployed an advanced ECG (A-ECG) system developed at NASA for improved sensitivity and specificity in the detection of cardiac risk. METHODS Forty-four professional firefighters were recruited to perform comprehensive baseline assessments including tests of aerobic performance and laboratory tests for fasting lipid profiles and glucose. Heart rate and conventional 12-lead ECG were obtained at rest and during incremental treadmill exercise testing (XT). In addition, a 5-min resting 12-lead A-ECG was obtained in a subset of firefighters (n=18) and transmitted over a secure networked system to a physician collaborator at NASA for advanced-ECG analysis. This A-ECG system has been proven, using myocardial perfusion and other imaging, to accurately identify a number of cardiac pathologies including coronary artery disease (CAD), left ventricular hypertrophy, hypertrophic cardiomyopathy, non-ischemic cardiomyopathy, and ischemic cardiomyopathy. RESULTS Subjects mean (SD) age was 43 (8) years, weight 91 (13) kg, and BMI of 28 (3) kg/square meter. Maximum oxygen uptake (VO2max) was 39 (9) ml/kg/min. This compares with the 45th %ile in healthy reference values and a recommended standard of 42 ml/kg/min for firefighters. The metabolic threshold (VO

  4. Pattern classification of time plane features of ECG wave from cell-phone photography for machine aided cardiac disease diagnosis.

    PubMed

    Mitra, Rupendra Nath; Pramanik, Sayak; Mitra, Sucharita; Chaudhuri, Bidyut B

    2014-01-01

    This article reports a robust technique for extracting time plane features of Electrocardiogram (ECG) from digital images of ECG paper strips. We concluded this article reporting performance evaluation of the system developed for machine aided cardiac disease detection. Mostly paper based ECG recordings are used in developing countries and digital photographs of different leads could easily be taken and sent with a mediocre cellular phone set. Apart from extracting the features, the proposed system detects cardiac axis deviation and diagnose if Left or Right Bundle Branch Blockage (LBBB or RBBB) is present while fed with the digital photographs of different leads of ECG strips. Preprocessing of the low-resolution images involves background grid line noise removal, adaptive image binarization by Sauvola's method and Bresenham's line joining algorithm to link the ECG signature, if broken. Pattern extraction mainly delineate the time plane features like P wave, QRS complex and T wave using water reservoir based pattern recognition techniques and Discrete Wavelet Transform (DWT). Cardiac axis deviation detection is done by checking the overall voltage levels of QRS complexes of lead I, II and III. Having the knowledge of cardiac axis completes the requirements to comment on the cardiac blockage like Left or Right Bundle Branch Blockage (LBBB or RBBB). Thus, the proposed algorithm is primarily developed for machine aided diagnosis of LBBB or RBBB from the digital photographs of ECG paper strips. PMID:25571067

  5. A 58 nW ECG ASIC With Motion-Tolerant Heartbeat Timing Extraction for Wearable Cardiovascular Monitoring.

    PubMed

    Da He, David; Sodini, Charles G

    2015-06-01

    An ASIC for wearable cardiovascular monitoring is implemented using a topology that takes advantage of the electrocardiogram's (ECG) waveform to replace the traditional ECG instrumentation amplifier, ADC, and signal processor with a single chip solution. The ASIC can extract heartbeat timings in the presence of baseline drift, muscle artifact, and signal clipping. The circuit can operate with ECGs ranging from the chest location to remote locations where the ECG magnitude is as low as 30 μV. Besides heartbeat detection, a midpoint estimation method can accurately extract the ECG R-wave timing, enabling the calculations of heart rate variability. With 58 nW of power consumption at 0.8 V supply voltage and 0.76 mm (2) of active die area in standard 0.18 μm CMOS technology, the ECG ASIC is sufficiently low power and compact to be suitable for long term and wearable cardiovascular monitoring applications under stringent battery and size constraints. PMID:25252285

  6. Position difference regularity of corresponding R-wave peaks for maternal ECG components from different abdominal points

    NASA Astrophysics Data System (ADS)

    Zhang, Jie-Min; Guan, Qun; Tang, Li-Ming; Liu, Tie-Bing; Liu, Hong-Xing; Huang, Xiao-Lin; Si, Jun-Feng

    2014-01-01

    We collected 343 groups of abdominal electrocardiogram (ECG) data from 78 pregnant women and deleted the channels unable for experts to determine R-wave peaks from them; then, based on these filtered data, the statistics of position difference of corresponding R-wave peaks for different maternal ECG components from different points were studied. The resultant statistics showed the regularity that the position difference of corresponding maternal R-wave peaks between different abdominal points does not exceed the range of 30 ms. The regularity was also proved using the fECG data from MIT—BIH PhysioBank. Additionally, the paper applied the obtained regularity, the range of position differences of the corresponding maternal R-wave peaks, to accomplish the automatic detection of maternal R-wave peaks in the recorded all initial 343 groups of abdominal signals, including the ones with the largest fetal ECG components, and all 55 groups of ECG data from MIT—BIH PhysioBank, achieving the successful separation of the maternal ECGs.

  7. A novel approach for removing ECG interferences from surface EMG signals using a combined ANFIS and wavelet.

    PubMed

    Abbaspour, Sara; Fallah, Ali; Lindén, Maria; Gholamhosseini, Hamid

    2016-02-01

    In recent years, the removal of electrocardiogram (ECG) interferences from electromyogram (EMG) signals has been given large consideration. Where the quality of EMG signal is of interest, it is important to remove ECG interferences from EMG signals. In this paper, an efficient method based on a combination of adaptive neuro-fuzzy inference system (ANFIS) and wavelet transform is proposed to effectively eliminate ECG interferences from surface EMG signals. The proposed approach is compared with other common methods such as high-pass filter, artificial neural network, adaptive noise canceller, wavelet transform, subtraction method and ANFIS. It is found that the performance of the proposed ANFIS-wavelet method is superior to the other methods with the signal to noise ratio and relative error of 14.97dB and 0.02 respectively and a significantly higher correlation coefficient (p<0.05). PMID:26643795

  8. A Novel ECG Data Compression Method Using Adaptive Fourier Decomposition With Security Guarantee in e-Health Applications.

    PubMed

    Ma, JiaLi; Zhang, TanTan; Dong, MingChui

    2015-05-01

    This paper presents a novel electrocardiogram (ECG) compression method for e-health applications by adapting an adaptive Fourier decomposition (AFD) algorithm hybridized with a symbol substitution (SS) technique. The compression consists of two stages: first stage AFD executes efficient lossy compression with high fidelity; second stage SS performs lossless compression enhancement and built-in data encryption, which is pivotal for e-health. Validated with 48 ECG records from MIT-BIH arrhythmia benchmark database, the proposed method achieves averaged compression ratio (CR) of 17.6-44.5 and percentage root mean square difference (PRD) of 0.8-2.0% with a highly linear and robust PRD-CR relationship, pushing forward the compression performance to an unexploited region. As such, this paper provides an attractive candidate of ECG compression method for pervasive e-health applications. PMID:25222961

  9. A Novel ECG Data Compression Method Using Adaptive Fourier Decomposition With Security Guarantee in e-Health Applications.

    PubMed

    Ma, JiaLi; Zhang, TanTan; Dong, MingChui

    2015-05-01

    This paper presents a novel electrocardiogram (ECG) compression method for e-health applications by adapting an adaptive Fourier decomposition (AFD) algorithm hybridized with a symbol substitution (SS) technique. The compression consists of two stages: first stage AFD executes efficient lossy compression with high fidelity; second stage SS performs lossless compression enhancement and built-in data encryption, which is pivotal for e-health. Validated with 48 ECG records from MIT-BIH arrhythmia benchmark database, the proposed method achieves averaged compression ratio (CR) of 17.6-44.5 and percentage root mean square difference (PRD) of 0.8-2.0% with a highly linear and robust PRD-CR relationship, pushing forward the compression performance to an unexploited region. As such, this paper provides an attractive candidate of ECG compression method for pervasive e-health applications.

  10. Effects of freeze-dried red wine on cardiac function and ECG of the Langendorff-perfused rat heart.

    PubMed

    Ferrara, Antonella; Fusi, Fabio; Gorelli, Beatrice; Sgaragli, Giampietro; Saponara, Simona

    2014-02-01

    The effect of freeze-dried red wine (FDRW) on cardiac function and electrocardiogram (ECG) in Langendorff-isolated rat hearts was investigated. FDRW significantly decreased left ventricular pressure and coronary perfusion pressure, the latter being dependent on the activation of both phosphatidylinositol 3-kinase and eNOS. FDRW did not affect the QRS and QT interval in the ECG, although at 56 μg of gallic acid equivalents/mL, it prolonged PQ interval and induced a second-degree atrioventricular block in 3 out of 6 hearts. This is the first study demonstrating that at concentrations resembling a moderate consumption of red wine, FDRW exhibited negative inotropic and coronary vasodilating activity leaving unaltered ECG, whereas at very high concentrations, it induced arrhythmogenic effects.

  11. The HERO-2 ECG sub-studies in patients with ST elevation myocardial infarction: implications for clinical practice.

    PubMed

    Wong, Cheuk-Kit; White, Harvey D

    2013-12-01

    The ECG studies of the international HERO-2 trial in ST elevation myocardial infarction (STEMI) patients evaluated the prognostic value of ECGs systematically recorded at baseline and at 60-min post-administration of fibrinolytic therapy. Patients were overall managed conservatively with a low percentage undergoing angiography. Many of the analyses were pre-specified. While modern management of STEMI has improved, particularly with the widespread use of primary angioplasty, the HERO-2 database documents the prognostic relationship between ECG findings in STEMI patients managed with fibrinolytic therapy and 30-day mortality. This article describes the history of the HERO-2 ECG sub-studies, discloses new information in the project development and summarizes its findings. The strength of having serial ECG recordings is discussed as is the weakness of lacking angiographic correlation. The paper discusses with take-home points (Table 1) the prognostic implications of bundle branch blocks, QRS duration, Q waves in infarct leads, V1 ST elevation during inferior STEMI, lead aVR ST changes and new ST depression in the infarct leads after fibrinolysis. With the ever increasing emphasis on early (including pre-hospital) therapies for STEMI, a diagnosis based on the 12-lead ECG, the current summary article provides helpful hints to fully extract ECG information, and a vision for future STEMI diagnosis and management.

  12. Determinants of discrepancies in detection and comparison of the prognostic significance of left ventricular hypertrophy by electrocardiogram and cardiac magnetic resonance imaging.

    PubMed

    Bacharova, Ljuba; Chen, Haiying; Estes, E Harvey; Mateasik, Anton; Bluemke, David A; Lima, Joao A C; Burke, Gregory L; Soliman, Elsayed Z

    2015-02-15

    Despite the low sensitivity of the electrocardiogram (ECG) in detecting left ventricular hypertrophy (LVH), ECG-LVH is known to be a strong predictor of cardiovascular risk. Understanding reasons for the discrepancies in detection of LVH by ECG versus imaging could help improve the diagnostic ability of ECG. We examined factors associated with false-positive and false-negative ECG-LVH, using cardiac magnetic resonance imaging (MRI) as the gold standard. We also compared the prognostic significance of ECG-LVH and MRI-LVH as predictors of cardiovascular events. This analysis included 4,748 participants (mean age 61.9 years, 53.5% females, 61.7% nonwhites). Logistic regression with stepwise selection was used to identify factors associated with false-positive (n = 208) and false-negative (n = 387), compared with true-positive (n = 208) and true-negative (n = 4,041) ECG-LVH, respectively. A false-negative ECG-LVH status was associated with increased odds of Hispanic race/ethnicity, current smoking, hypertension, increased systolic blood pressure, prolongation of QRS duration, and higher body mass index and with lower odds of increased ejection fraction (model-generalized R(2) = 0.20). A false-positive ECG-LVH status was associated with lower odds of black race, Hispanic race/ethnicity, minor ST-T abnormalities, increased systolic blood pressure, and presence of any major electrocardiographic abnormalities (model-generalized R(2) = 0.29). Both ECG-LVH and MRI-LVH were associated with an increased risk of cardiovascular disease events (hazard ratio 1.51, 95% confidence interval 1.03 to 2.20 and hazard ratio 1.81, 95% confidence interval 1.33 to 2.46, respectively). In conclusion, discrepancy in LVH detection by ECG and MRI can be relatively improved by considering certain participant characteristics. Discrepancy in diagnostic performance, yet agreement on predictive ability, suggests that LVH by ECG and LVH by imaging are likely to be two distinct but somehow related

  13. Non-Invasive Drosophila ECG Recording by Using Eutectic Gallium-Indium Alloy Electrode: A Feasible Tool for Future Research on the Molecular Mechanisms Involved in Cardiac Arrhythmia

    PubMed Central

    Kuo, Po-Hung; Tzeng, Te-Hsuen; Huang, Yi-Chun; Chen, Yu-Hao; Chang, Yi-Chung; Ho, Yi-Lwun; Wu, June-Tai; Lee, Hsiu-Hsian; Lai, Po-Jung; Liu, Kwei-Yan; Cheng, Ya-Chen; Lu, Shey-Shi

    2014-01-01

    Background Drosophila heart tube is a feasible model for cardiac physiological research. However, obtaining Drosophila electrocardiograms (ECGs) is difficult, due to the weak signals and limited contact area to apply electrodes. This paper presents a non-invasive Gallium-Indium (GaIn) based recording system for Drosophila ECG measurement, providing the heart rate and heartbeat features to be observed. This novel, high-signal-quality system prolongs the recording time of insect ECGs, and provides a feasible platform for research on the molecular mechanisms involved in cardiovascular diseases. Methods In this study, two types of electrode, tungsten needle probes and GaIn electrodes, were used respectively to noiselessly conduct invasive and noninvasive ECG recordings of Drosophila. To further analyze electrode properties, circuit models were established and simulated. By using electromagnetic shielded heart signal acquiring system, consisted of analog amplification and digital filtering, the ECG signals of three phenotypes that have different heart functions were recorded without dissection. Results and Discussion The ECG waveforms of different phenotypes of Drosophila recorded invasively and repeatedly with n value (n>5) performed obvious difference in heart rate. In long period ECG recordings, non-invasive method implemented by GaIn electrodes acts relatively stable in both amplitude and period. To analyze GaIn electrode, the correctness of GaIn electrode model established by this paper was validated, presenting accuracy, stability, and reliability. Conclusions Noninvasive ECG recording by GaIn electrodes was presented for recording Drosophila pupae ECG signals within a limited contact area and signal strength. Thus, the observation of ECG changes in normal and SERCA-depleted Drosophila over an extended period is feasible. This method prolongs insect survival time while conserving major ECG features, and provides a platform for electrophysiological signal research

  14. Comparative study of ECG signal denoising by wavelet thresholding in empirical and variational mode decomposition domains.

    PubMed

    Lahmiri, Salim

    2014-09-01

    Hybrid denoising models based on combining empirical mode decomposition (EMD) and discrete wavelet transform (DWT) were found to be effective in removing additive Gaussian noise from electrocardiogram (ECG) signals. Recently, variational mode decomposition (VMD) has been proposed as a multiresolution technique that overcomes some of the limits of the EMD. Two ECG denoising approaches are compared. The first is based on denoising in the EMD domain by DWT thresholding, whereas the second is based on noise reduction in the VMD domain by DWT thresholding. Using signal-to-noise ratio and mean of squared errors as performance measures, simulation results show that the VMD-DWT approach outperforms the conventional EMD-DWT. In addition, a non-local means approach used as a reference technique provides better results than the VMD-DWT approach. PMID:26609387

  15. VLSI implementation of a new LMS-based algorithm for noise removal in ECG signal

    NASA Astrophysics Data System (ADS)

    Satheeskumaran, S.; Sabrigiriraj, M.

    2016-06-01

    Least mean square (LMS)-based adaptive filters are widely deployed for removing artefacts in electrocardiogram (ECG) due to less number of computations. But they posses high mean square error (MSE) under noisy environment. The transform domain variable step-size LMS algorithm reduces the MSE at the cost of computational complexity. In this paper, a variable step-size delayed LMS adaptive filter is used to remove the artefacts from the ECG signal for improved feature extraction. The dedicated digital Signal processors provide fast processing, but they are not flexible. By using field programmable gate arrays, the pipelined architectures can be used to enhance the system performance. The pipelined architecture can enhance the operation efficiency of the adaptive filter and save the power consumption. This technique provides high signal-to-noise ratio and low MSE with reduced computational complexity; hence, it is a useful method for monitoring patients with heart-related problem.

  16. An ECG oximetry system for identifying obstructive and central apnoea events.

    PubMed

    de Chazal, Philip; Sadr, Nadi; Jayawardhana, Madhuka

    2015-01-01

    An automatic algorithm for processing simultaneously acquired electrocardiogram (ECG) and oximetry signals that identifies epochs of pure central apnoea, epochs containing obstructive apnoea and epochs of normal breathing is presented. The algorithm uses time and spectral features from the ECG derived heart-rate and respiration information, as well as features capturing desaturations from the oximeter sensor. Evaluation of performance of the system was achieved by using leave-one-record-out cross validation on the St. Vincent's University Hospital / University College Dublin Sleep Apnea Database from the Physionet collections of recorded physiologic signals. When classifying the three epoch types, our system achieved a specificity of 80%, a sensitivity to central apnoea of 44% and sensitivity to obstructive apnoea of 35%. A sensitivity of 81% was achieved when the central and obstructive epochs were combined into one class.

  17. The exploitation of spatial topographies for atrial signal extraction in atrial fibrillation ECGs.

    PubMed

    Bonizzi, Pietro; Phlypo, Ronald; Zarzoso, Vicente; Meste, Olivier

    2008-01-01

    The accuracy in the extraction of the atrial activity (AA) from electrocardiogram (ECG) signals recorded during atrial fibrillation (AF) episodes plays an important role in the analysis and characterization of atrial arrhythmias. The present contribution puts forward a method for AA signal extraction based on a blind source separation (BSS) formulation. The latter exploits spatial information on the different components in the ECG related or not to AF. The source directions or spatial topographies of the components not related to AF are used to determine the nullspace of the AA, so that the topographies related to AA become more suitable to describe AF sources. The comparative performance of the method is evaluated on real data recorded from patients with noticeable AF. The AA extraction quality of the proposed technique is comparable to that of previous algorithms.

  18. An ECG oximetry system for identifying obstructive and central apnoea events.

    PubMed

    de Chazal, Philip; Sadr, Nadi; Jayawardhana, Madhuka

    2015-01-01

    An automatic algorithm for processing simultaneously acquired electrocardiogram (ECG) and oximetry signals that identifies epochs of pure central apnoea, epochs containing obstructive apnoea and epochs of normal breathing is presented. The algorithm uses time and spectral features from the ECG derived heart-rate and respiration information, as well as features capturing desaturations from the oximeter sensor. Evaluation of performance of the system was achieved by using leave-one-record-out cross validation on the St. Vincent's University Hospital / University College Dublin Sleep Apnea Database from the Physionet collections of recorded physiologic signals. When classifying the three epoch types, our system achieved a specificity of 80%, a sensitivity to central apnoea of 44% and sensitivity to obstructive apnoea of 35%. A sensitivity of 81% was achieved when the central and obstructive epochs were combined into one class. PMID:26738069

  19. Improving ECG Classification Accuracy Using an Ensemble of Neural Network Modules

    PubMed Central

    Javadi, Mehrdad; Ebrahimpour, Reza; Sajedin, Atena; Faridi, Soheil; Zakernejad, Shokoufeh

    2011-01-01

    This paper illustrates the use of a combined neural network model based on Stacked Generalization method for classification of electrocardiogram (ECG) beats. In conventional Stacked Generalization method, the combiner learns to map the base classifiers' outputs to the target data. We claim adding the input pattern to the base classifiers' outputs helps the combiner to obtain knowledge about the input space and as the result, performs better on the same task. Experimental results support our claim that the additional knowledge according to the input space, improves the performance of the proposed method which is called Modified Stacked Generalization. In particular, for classification of 14966 ECG beats that were not previously seen during training phase, the Modified Stacked Generalization method reduced the error rate for 12.41% in comparison with the best of ten popular classifier fusion methods including Max, Min, Average, Product, Majority Voting, Borda Count, Decision Templates, Weighted Averaging based on Particle Swarm Optimization and Stacked Generalization. PMID:22046232

  20. PROPOSED SIMPLE METHOD FOR ELECTROCARDIOGRAM RECORDING IN FREE-RANGING ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

    PubMed

    Chai, Norin; Pouchelon, Jean Louis; Bouvard, Jonathan; Sillero, Leonor Camacho; Huynh, Minh; Segalini, Vincent; Point, Lisa; Croce, Veronica; Rigaux, Goulven; Highwood, Jack; Chetboul, Valérie

    2016-03-01

    Electrocardiography represents a relevant diagnostic tool for detecting cardiac disease in animals. Elephants can present various congenital and acquired cardiovascular diseases. However, few electrophysiologic studies have been reported in captive elephants, mainly due to challenging technical difficulties in obtaining good-quality electrocardiogram (ECG) tracings, and no data are currently available for free-ranging Asian elephants (Elephas maximus). The purpose of this pilot prospective study was to evaluate the feasibility of using a simple method for recording ECG tracings in wild, apparently healthy, unsedated Asian elephants (n = 7) in the standing position. Successful six-lead recordings (I, II, III, aVR, aVL, and aVF) were obtained, with the aVL lead providing the best-quality tracings in most animals. Variables measured in the aVL lead included heart rate, amplitudes and duration of the P waves, QRS complexes, T and U waves, and duration of the PR, QT, and QU intervals. A negative deflection following positive P waves, representative of an atrial repolarization wave (Ta wave), was observed for five out of the seven elephants.

  1. Combining neural networks and ANFIS classifiers for supervised examining of electrocardiogram beats.

    PubMed

    Javadi, Mehrdad

    2013-11-01

    Abstract In this paper, the supervised classification of the electrocardiogram (ECG) beats based on the fusion of several intelligent learning machines is described. For classification of ECG heartbeats, first, the QRS complexes are delineated by an efficient algorithm so as to identify the fiducial and J-locations of each complex. For each delineated QRS complex, a feature vector is established based on the geometrical properties of the complex waveform and its associated discrete-wavelet transform. Next, three different multi-layer perceptron back-propagation (MLP-BP) networks are trained with different topologies and intrinsic parameters. Afterwards, the outputs of MLP-BPs are used as the new feature space elements for training three adaptive fuzzy network inference systems (ANFIS) in order to increase the final accuracy. At the end, the outputs of ANFIS classifiers are voted based on majority for each input sample. The method was applied to seven arrhythmias (Normal, LBBB, RBBB, PVC, APB, VE, VF) which belong to the MIT-BIH Arrhythmia Database and the average accuracy value Acc=98.28% was achieved for the beat-level. Also, the proposed method was assessed to five arrhythmias (Normal, LBBB, RBBB, PVC, APB) according to validation standards of the American Heart Association (AHA) at record (subject) level and the average accuracy value Acc=73.39% was achieved. To evaluate performance quality of the new proposed hybrid learning machine, the obtained results were compared with similar peer-reviewed studies in this area. PMID:24044548

  2. New approach for T-wave end detection on electrocardiogram: Performance in noisy conditions

    PubMed Central

    2011-01-01

    Background The detection of T-wave end points on electrocardiogram (ECG) is a basic procedure for ECG processing and analysis. Several methods have been proposed and tested, featuring high accuracy and percentages of correct detection. Nevertheless, their performance in noisy conditions remains an open problem. Methods A new approach and algorithm for T-wave end location based on the computation of Trapezium's areas is proposed and validated (in terms of accuracy and repeatability), using signals from the Physionet QT Database. The performance of the proposed algorithm in noisy conditions has been tested and compared with one of the most used approaches for estimating the T-wave end point: the method based on the threshold on the first derivative. Results The results indicated that the proposed approach based on Trapezium's areas outperformed the baseline method with respect to accuracy and repeatability. Also, the proposed method is more robust to wideband noise. Conclusions The trapezium-based approach has a good performance in noisy conditions and does not rely on any empirical threshold. It is very adequate for use in scenarios where the levels of broadband noise are significant. PMID:21906317

  3. Automated and manufacturer independent assessment of the battery status of implanted cardiac pacemakers by electrocardiogram analysis.

    PubMed

    Schreier, G; Hayn, D; Kollmann, A; Scherr, D; Lercher, P; Rotman, B; Klein, W

    2004-01-01

    According to international standards, cardiac pacemakers have to indicate the status of their batteries upon magnet application by specific stimulation patterns. The purpose of this study has been to assess whether this concept can be used as a basis for automated and manufacturer independent examination of the depletion level of pacemakers in the framework of a collaborative telemedical pacemaker follow-up system. A prototype of such a system was developed and tested in a real clinical environment. Electrocardiograms (ECGs) were recorded during magnet application and automatically processed to extract the specific stimulation patterns. The results were used to assign each signal a corresponding pacemaker status: "ok," "replace" or "undefined," based on the expected behavior of the devices as specified by the manufacturer. The outcome of this procedure was compared to the result of an expert examination, resulting in a positive predictive value of 100% for the detection of ECGs indicating pacemaker status "ok." The method can, therefore, be utilized to quickly, safely and manufacturer neutrally classify cases into the categories "ok" and "needs further checking," which - in a telemedical setting - may be used to increase the efficiency of pacemaker follow-up procedures in the future. PMID:17271607

  4. PROPOSED SIMPLE METHOD FOR ELECTROCARDIOGRAM RECORDING IN FREE-RANGING ASIAN ELEPHANTS (ELEPHAS MAXIMUS).

    PubMed

    Chai, Norin; Pouchelon, Jean Louis; Bouvard, Jonathan; Sillero, Leonor Camacho; Huynh, Minh; Segalini, Vincent; Point, Lisa; Croce, Veronica; Rigaux, Goulven; Highwood, Jack; Chetboul, Valérie

    2016-03-01

    Electrocardiography represents a relevant diagnostic tool for detecting cardiac disease in animals. Elephants can present various congenital and acquired cardiovascular diseases. However, few electrophysiologic studies have been reported in captive elephants, mainly due to challenging technical difficulties in obtaining good-quality electrocardiogram (ECG) tracings, and no data are currently available for free-ranging Asian elephants (Elephas maximus). The purpose of this pilot prospective study was to evaluate the feasibility of using a simple method for recording ECG tracings in wild, apparently healthy, unsedated Asian elephants (n = 7) in the standing position. Successful six-lead recordings (I, II, III, aVR, aVL, and aVF) were obtained, with the aVL lead providing the best-quality tracings in most animals. Variables measured in the aVL lead included heart rate, amplitudes and duration of the P waves, QRS complexes, T and U waves, and duration of the PR, QT, and QU intervals. A negative deflection following positive P waves, representative of an atrial repolarization wave (Ta wave), was observed for five out of the seven elephants. PMID:27010258

  5. Numerical simulation of electrocardiograms for full cardiac cycles in healthy and pathological conditions.

    PubMed

    Schenone, Elisa; Collin, Annabelle; Gerbeau, Jean-Frédéric

    2016-05-01

    This work is dedicated to the simulation of full cycles of the electrical activity of the heart and the corresponding body surface potential. The model is based on a realistic torso and heart anatomy, including ventricles and atria. One of the specificities of our approach is to model the atria as a surface, which is the kind of data typically provided by medical imaging for thin volumes. The bidomain equations are considered in their usual formulation in the ventricles, and in a surface formulation on the atria. Two ionic models are used: the Courtemanche-Ramirez-Nattel model on the atria and the 'minimal model for human ventricular action potentials' by Bueno-Orovio, Cherry, and Fenton in the ventricles. The heart is weakly coupled to the torso by a Robin boundary condition based on a resistor-capacitor transmission condition. Various electrocardiograms (ECGs) are simulated in healthy and pathological conditions (left and right bundle branch blocks, Bachmann's bundle block, and Wolff-Parkinson-White syndrome). To assess the numerical ECGs, we use several qualitative and quantitative criteria found in the medical literature. Our simulator can also be used to generate the signals measured by a vest of electrodes. This capability is illustrated at the end of the article. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26249327

  6. Electromagnetic interference produced by a hearing aid device on electrocardiogram recording.

    PubMed

    Baranchuk, Adrian Marco; Kang, Jaskaran; Shaw, Cathy; Witjes, Rita

    2008-01-01

    An 85-year-old male was implanted with a single-chamber permanent pacemaker because of atrial fibrillation with slow ventricular response. The patient had a chronic hearing impairment and decided to buy a hearing aid device. The MyLink device (MyLink, Phonak, Stafa, Switzerland) is a multifrequency FM transmitter/receiver (169.40-176.00 MHz and 214.00-220.00 MHz) with a neck-loop antenna that is designed to be used in combination with a second FM transmitter, which detects sound, produced by an audio source or person, and transmits this information to the MyLink wearer. These transmissions are subsequently converted by the MyLink and sent to the patient's existing hearing aids wirelessly. Given the proximity of the receiver to the left-sided pacemaker pocket, a concern about possible interaction was brought to our attention. Normal functioning of the pacemaker was observed during the test. However, potent electromagnetic interference on electrocardiogram (ECG) recording was induced when the MyLink loop antenna was placed on top or near the ECG electrodes.

  7. The effect of acupuncture at PC-6 on the electroencephalogram and electrocardiogram.

    PubMed

    Kim, Min Soo; Kim, Hak Dong; Seo, Hee Don; Sawada, Kazuaki; Ishida, Makoto

    2008-01-01

    The present study aims to examine the effect of acupuncture stimulation of an acupuncture point (PC-6) and nonacupuncture point on electroencephalograms (EEGs) and electrocardiograms (ECGs). We used EEG in 10 healthy subjects to investigate cortical activation during stimulation of acupuncture points (neiguan: PC-6) and nonacupuncture points. Our most interesting finding was the marked differences of amplitude of EEG power between acupuncture points and nonacupuncture points stimulation. Wavelet transform was used as the EEG signal processing method, because it has advantages in a time domain and frequency domain characteristics analysis. EEGs were collected from 16 channels, and the alpha-wave (8-13 Hz), beta-wave (13-30 Hz), theta-wave (4-8 Hz) and delta-wave (0.5-4 Hz) were used as standards for frequency bands. According to the experiment results, EEG signals increased considerably after acupuncture stimulation; in each frequency band, the average amplitude was higher after acupuncture stimulation; ECG heart rates were faster by at least 10% after acupuncture stimulation. Consequently, it will be possible to verify the function of acupuncture stimulation on neiguan (acupuncture points; PC-6) more effectively.

  8. Gold-195m first-pass radionuclide ventriculography, thallium-201 single-photon emission CT, and 12-lead ECG stress testing as a combined procedure

    SciTech Connect

    Kipper, S.L.; Ashburn, W.L.; Norris, S.L.; Rimkus, D.S.; Dillon, W.A.

    1985-09-01

    Graded, sequential, rest/exercise, gold-195m, first-pass ventriculography and thallium-201 (Tl-201) single-photon emission computed tomography (SPECT) were performed simultaneously during a single, electrocardiograph-monitored, bicycle stress test in 24 individuals. The technical aspects and logistics involved in performing this combined radionuclide study are stressed in this preliminary report. Fourteen healthy volunteers each had a normal left ventricular ejection fraction and wall-motion response, along with normal T1-201 perfusion and washout, as determined by both visual and quantitative analysis of the tomographic sections. Each of ten patients with coronary artery disease had at least one abnormality of these parameters. The authors suggest that it is technically feasible to evaluate both cardiac function and myocardial perfusion simultaneously by combing Au-195m ventriculography and Tl-201 SPECT imaging into a single, noninvasive, diagnostic package.

  9. Simplified 2D Bidomain Model of Whole Heart Electrical Activity and ECG Generation

    NASA Astrophysics Data System (ADS)

    Sovilj, Siniša; Magjarević, Ratko; Abed, Amr Al; Lovell, Nigel H.; Dokos, Socrates

    2014-06-01

    The aim of this study was the development of a geometrically simple and highly computationally-efficient two dimensional (2D) biophysical model of whole heart electrical activity, incorporating spontaneous activation of the sinoatrial node (SAN), the specialized conduction system, and realistic surface ECG morphology computed on the torso. The FitzHugh-Nagumo (FHN) equations were incorporated into a bidomain finite element model of cardiac electrical activity, which was comprised of a simplified geometry of the whole heart with the blood cavities, the lungs and the torso as an extracellular volume conductor. To model the ECG, we placed four electrodes on the surface of the torso to simulate three Einthoven leads VI, VII and VIII from the standard 12-lead system. The 2D model was able to reconstruct ECG morphology on the torso from action potentials generated at various regions of the heart, including the sinoatrial node, atria, atrioventricular node, His bundle, bundle branches, Purkinje fibers, and ventricles. Our 2D cardiac model offers a good compromise between computational load and model complexity, and can be used as a first step towards three dimensional (3D) ECG models with more complex, precise and accurate geometry of anatomical structures, to investigate the effect of various cardiac electrophysiological parameters on ECG morphology.

  10. Simulation of elevated T-waves of an ECG inside a static magnetic field (MRI).

    PubMed

    Gupta, Aditya; Weeks, Arthur R; Richie, Samuel M

    2008-07-01

    In MRI, the flow of blood in the patient is subjected to a strong static magnetic field (B(0)). The movement of charge carriers in a magnetic field causes a magnetofluid dynamic (MFD) effect that induces a voltage across the artery. This induced voltage distorts the ECG signal of the patient and appears as an elevation of the T-wave of the ECG signal. Flow of blood through the aortic arch is perpendicular to the magnetic field and coincides with the occurrence of the T-wave of the ECG. Based on these facts, it is proposed that the elevation in the T-wave occurs because of the voltage induced across the aortic arch. In this paper, the elevation is computed mathematically using the equations of MFD. A method is developed to measure this induced voltage based on discretization of the aortic arch and measuring the blood flow profile in the aorta. The results are compared to the ECG signals measured in humans in the bore of 1.5 T imaging magnet. The computed ECG signals at the 12 leads are very similar to the measured values. PMID:18595808

  11. New Features of Electrocardiogram in a Case Report of Arrhythmogenic Right Ventricular Cardiomyopathy

    PubMed Central

    Pei, Haifeng; Yu, Qiujun; Su, Xiaohua; Wang, Zhen; Zhao, Heng; Yang, Dachun; Yang, Yongjian; Li, De

    2016-01-01

    Abstract Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a crucial health problem. With sudden death often being the first presentation, early diagnosis for ARVC is essential. Up to date, electrocardiogram (ECG) is a widely used diagnostic method without invasive harms. To diagnose and treat ARVC as well as possible, we should clearly elucidate its pathophysiological alterations. A 66-year-old farmer presented to the Emergency Department with continuous palpitation, chest tightness, profuse sweating, and nausea with no obvious predisposing causes. An ECG indicated ventricular tachycardia (VT). The patient experienced a sudden drop in blood pressure and acute confusion. After an immediate electrical conversion, his consciousness was gradually restored, and symptoms relieved. The patient was then transferred to the Department of Cardiology to receive ECG, echocardiography, coronary angiogram, biochemical assays, endocardiac tracing, and radiofrequency ablation. In the end, he was diagnosed with ARVC, evidenced by bilateral ventricle dilation and epsilon waves in leads V1–V3. Appropriate therapies were provided for this patient including pharmacological intervention and radiofrequency ablation. Although the diagnosis of ARVC is not difficult, this patient's ECG manifested several interesting features and should be further investigated: T wave inversions were found extensively in the anterior and inferior leads, revealing the involvement of bilateral ventricles; VTs with different morphologies and cycle lengths were found, and some VTs manifested the feature of irregularly irregular rhythm, reminding us to carefully differentiate some special VTs from atrial fibrillation (AF); and epsilon waves gradually appeared in leads V1–V3 and avR since the onset of ARVC. Most importantly, the epsilon waves behind QRS complex appeared in both sinus rhythm and ventricular premature beats/VT originating from cardiac apex, whereas the epsilon waves prior to QRS complex

  12. Semisupervised ECG Ventricular Beat Classification With Novelty Detection Based on Switching Kalman Filters.

    PubMed

    Oster, Julien; Behar, Joachim; Sayadi, Omid; Nemati, Shamim; Johnson, Alistair E W; Clifford, Gari D

    2015-09-01

    Automatic processing and accurate diagnosis of pathological electrocardiogram (ECG) signals remains a challenge. As long-term ECG recordings continue to increase in prevalence, driven partly by the ease of remote monitoring technology usage, the need to automate ECG analysis continues to grow. In previous studies, a model-based ECG filtering approach to ECG data from healthy subjects has been applied to facilitate accurate online filtering and analysis of physiological signals. We propose an extension of this approach, which models not only normal and ventricular heartbeats, but also morphologies not previously encountered. A switching Kalman filter approach is introduced to enable the automatic selection of the most likely mode (beat type), while simultaneously filtering the signal using appropriate prior knowledge. Novelty detection is also made possible by incorporating a third mode for the detection of unknown (not previously observed) morphologies, and denoted as X-factor. This new approach is compared to state-of-the-art techniques for the ventricular heartbeat classification in the MIT-BIH arrhythmia and Incart databases. F1 scores of 98.3% and 99.5% were found on each database, respectively, which are superior to other published algorithms' results reported on the same databases. Only 3% of all the beats were discarded as X-factor, and the majority of these beats contained high levels of noise. The proposed technique demonstrates accurate beat classification in the presence of previously unseen (and unlearned) morphologies and noise, and provides an automated method for morphological analysis of arbitrary (unknown) ECG leads.

  13. Correlation of repolarization of ventricular monophasic action potential with ECG in the murine heart.

    PubMed

    Danik, Stephan; Cabo, Candido; Chiello, Christine; Kang, Sacha; Wit, Andrew L; Coromilas, James

    2002-07-01

    Transgenic mice have become important experimental models in the investigation of mechanisms causing cardiac arrhythmias because of the ability to create strains with alterations in repolarizing membrane currents. It is important to relate alterations in membrane currents in cells to their phenotypic expression on the electrocardiogram (ECG). The murine ECG, however, has unusual characteristics that make interpretation of the phenotypic expression of changes in ventricular repolarization uncertain. The major deflection representing the QRS (referred to as "a") is often followed by a secondary slower deflection ("b") and sometimes a subtle third deflection ("c"). To determine whether the second or third deflections or both represent ventricular repolarization, we recorded the ventricular monophasic action potential (MAP) in open-chest mice and correlated repolarization with the ECG. There was no significant correlation by linear regression, between action potential duration to 50% or 90% repolarization (APD(50) or APD(90)), respectively, of the MAP and either the interval from onset of Q to onset of b (Qb interval) or onset of c (Qc interval). Administration of 4-aminopyridine (4-AP) significantly prolonged APD(50) and APD(90) and the Qb interval, indicating that this deflection on the ECG represents part of ventricular repolarization. After 4-AP, the c wave disappeared, also suggesting that it represents a component of ventricular repolarization. Although it appears that both the b and c waves that follow the Q wave on the ECG represent ventricular repolarization, neither correlates exactly with APD(90) of the MAP. Therefore, an accurate measurement of complete repolarization of the murine ventricle cannot be obtained from the surface ECG. PMID:12063311

  14. Physical activities recognition from ambulatory ECG signals using neuro-fuzzy classifiers and support vector machines.

    PubMed

    Kher, Rahul; Pawar, Tanmay; Thakar, Vishvjit; Shah, Hitesh

    2015-02-01

    The use of wearable recorders for long-term monitoring of physiological parameters has increased in the last few years. The ambulatory electrocardiogram (A-ECG) signals of five healthy subjects with four body movements or physical activities (PA)-left arm up down, right arm up down, waist twisting and walking-have been recorded using a wearable ECG recorder. The classification of these four PAs has been performed using neuro-fuzzy classifier (NFC) and support vector machines (SVM). The PA classification is based on the distinct, time-frequency features of the extracted motion artifacts contained in recorded A-ECG signals. The motion artifacts in A-ECG signals have been separated first by the discrete wavelet transform (DWT) and the time-frequency features of these motion artifacts have then been extracted using the Gabor transform. The Gabor energy feature vectors have been fed to the NFC and SVM classifiers. Both the classifiers have achieved a PA classification accuracy of over 95% for all subjects. PMID:25641014

  15. Cancelling ECG Artifacts in EEG Using a Modified Independent Component Analysis Approach

    NASA Astrophysics Data System (ADS)

    Devuyst, Stéphanie; Dutoit, Thierry; Stenuit, Patricia; Kerkhofs, Myriam; Stanus, Etienne

    2008-12-01

    We introduce a new automatic method to eliminate electrocardiogram (ECG) noise in an electroencephalogram (EEG) or electrooculogram (EOG). It is based on a modification of the independent component analysis (ICA) algorithm which gives promising results while using only a single-channel electroencephalogram (or electrooculogram) and the ECG. To check the effectiveness of our approach, we compared it with other methods, that is, ensemble average subtraction (EAS) and adaptive filtering (AF). Tests were carried out on simulated data obtained by addition of a filtered ECG on a visually clean original EEG and on real data made up of 10 excerpts of polysomnographic (PSG) sleep recordings containing ECG artifacts and other typical artifacts (e.g., movement, sweat, respiration, etc.). We found that our modified ICA algorithm had the most promising performance on simulated data since it presented the minimal root mean-squared error. Furthermore, using real data, we noted that this algorithm was the most robust to various waveforms of cardiac interference and to the presence of other artifacts, with a correction rate of 91.0%, against 83.5% for EAS and 83.1% for AF.

  16. Automatic detection of ECG electrode misplacement: a tale of two algorithms.

    PubMed

    Xia, Henian; Garcia, Gabriel A; Zhao, Xiaopeng

    2012-09-01

    Artifacts in an electrocardiogram (ECG) due to electrode misplacement can lead to wrong diagnoses. Various computer methods have been developed for automatic detection of electrode misplacement. Here we reviewed and compared the performance of two algorithms with the highest accuracies on several databases from PhysioNet. These algorithms were implemented into four models. For clean ECG records with clearly distinguishable waves, the best model produced excellent accuracies (> = 98.4%) for all misplacements except the LA/LL interchange (87.4%). However, the accuracies were significantly lower for records with noise and arrhythmias. Moreover, when the algorithms were tested on a database that was independent from the training database, the accuracies may be poor. For the worst scenario, the best accuracies for different types of misplacements ranged from 36.1% to 78.4%. A large number of ECGs of various qualities and pathological conditions are collected every day. To improve the quality of health care, the results of this paper call for more robust and accurate algorithms for automatic detection of electrode misplacement, which should be developed and tested using a database of extensive ECG records.

  17. Issues in implementing a knowledge-based ECG analyzer for personal mobile health monitoring.

    PubMed

    Goh, K W; Kim, E; Lavanya, J; Kim, Y; Soh, C B

    2006-01-01

    Advances in sensor technology, personal mobile devices, and wireless broadband communications are enabling the development of an integrated personal mobile health monitoring system that can provide patients with a useful tool to assess their own health and manage their personal health information anytime and anywhere. Personal mobile devices, such as PDAs and mobile phones, are becoming more powerful integrated information management tools and play a major role in many people's lives. We focus on designing a health-monitoring system for people who suffer from cardiac arrhythmias. We have developed computer simulation models to evaluate the performance of appropriate electrocardiogram (ECG) analysis techniques that can be implemented on personal mobile devices. This paper describes an ECG analyzer to perform ECG beat and episode detection and classification. We have obtained promising preliminary results from our study. Also, we discuss several key considerations when implementing a mobile health monitoring solution. The mobile ECG analyzer would become a front-end patient health data acquisition module, which is connected to the Personal Health Information Management System (PHIMS) for data repository. PMID:17947185

  18. Adaptive neuro-fuzzy inference system for classification of ECG signals using Lyapunov exponents.

    PubMed

    Ubeyli, Elif Derya

    2009-03-01

    This paper describes the application of adaptive neuro-fuzzy inference system (ANFIS) model for classification of electrocardiogram (ECG) signals. Decision making was performed in two stages: feature extraction by computation of Lyapunov exponents and classification by the ANFIS trained with the backpropagation gradient descent method in combination with the least squares method. Four types of ECG beats (normal beat, congestive heart failure beat, ventricular tachyarrhythmia beat, and atrial fibrillation beat) obtained from the PhysioBank database were classified by four ANFIS classifiers. To improve diagnostic accuracy, the fifth ANFIS classifier (combining ANFIS) was trained using the outputs of the four ANFIS classifiers as input data. The proposed ANFIS model combined the neural network adaptive capabilities and the fuzzy logic qualitative approach. Some conclusions concerning the saliency of features on classification of the ECG signals were obtained through analysis of the ANFIS. The performance of the ANFIS model was evaluated in terms of training performance and classification accuracies and the results confirmed that the proposed ANFIS model has potential in classifying the ECG signals. PMID:19084286

  19. Consistent quality control in ECG compression by means of direct metrics.

    PubMed

    Hernando-Ramiro, Carlos; Blanco-Velasco, Manuel; Lovisolo, Lisandro; Cruz-Roldán, Fernando

    2015-09-01

    The aim of electrocardiogram (ECG) compression is to reduce the amount of data as much as possible while preserving the significant information for diagnosis. Objective metrics that are derived directly from the signal are suitable for controlling the quality of the compressed ECGs in practical applications. Many approaches have employed figures of merit based on the percentage root mean square difference (PRD) for this purpose. The benefits and drawbacks of the PRD measures, along with other metrics for quality assessment in ECG compression, are analysed in this work. We propose the use of the root mean square error (RMSE) for quality control because it provides a clearer and more stable idea about how much the retrieved ECG waveform, which is the reference signal for establishing diagnosis, separates from the original. For this reason, the RMSE is applied here as the target metric in a thresholding algorithm that relies on the retained energy. A state of the art compressor based on this approach, and its PRD-based counterpart, are implemented to test the actual capabilities of the proposed technique. Both compression schemes are employed in several experiments with the whole MIT-BIH Arrhythmia Database to assess both global and local signal distortion. The results show that, using the RMSE for quality control, the distortion of the reconstructed signal is better controlled without reducing the compression ratio. PMID:26260978

  20. Consistent quality control in ECG compression by means of direct metrics.

    PubMed

    Hernando-Ramiro, Carlos; Blanco-Velasco, Manuel; Lovisolo, Lisandro; Cruz-Roldán, Fernando

    2015-09-01

    The aim of electrocardiogram (ECG) compression is to reduce the amount of data as much as possible while preserving the significant information for diagnosis. Objective metrics that are derived directly from the signal are suitable for controlling the quality of the compressed ECGs in practical applications. Many approaches have employed figures of merit based on the percentage root mean square difference (PRD) for this purpose. The benefits and drawbacks of the PRD measures, along with other metrics for quality assessment in ECG compression, are analysed in this work. We propose the use of the root mean square error (RMSE) for quality control because it provides a clearer and more stable idea about how much the retrieved ECG waveform, which is the reference signal for establishing diagnosis, separates from the original. For this reason, the RMSE is applied here as the target metric in a thresholding algorithm that relies on the retained energy. A state of the art compressor based on this approach, and its PRD-based counterpart, are implemented to test the actual capabilities of the proposed technique. Both compression schemes are employed in several experiments with the whole MIT-BIH Arrhythmia Database to assess both global and local signal distortion. The results show that, using the RMSE for quality control, the distortion of the reconstructed signal is better controlled without reducing the compression ratio.

  1. Switching Kalman filter based methods for apnea bradycardia detection from ECG signals.

    PubMed

    Montazeri Ghahjaverestan, Nasim; Shamsollahi, Mohammad B; Ge, Di; Hernández, Alfredo I

    2015-09-01

    Apnea bradycardia (AB) is an outcome of apnea occurrence in preterm infants and is an observable phenomenon in cardiovascular signals. Early detection of apnea in infants under monitoring is a critical challenge for the early intervention of nurses. In this paper, we introduce two switching Kalman filter (SKF) based methods for AB detection using electrocardiogram (ECG) signal.The first SKF model uses McSharry's ECG dynamical model integrated in two Kalman filter (KF) models trained for normal and AB intervals. Whereas the second SKF model is established by using only the RR sequence extracted from ECG and two AR models to be fitted in normal and AB intervals. In both SKF approaches, a discrete state variable called a switch is considered that chooses one of the models (corresponding to normal and AB) during the inference phase. According to the probability of each model indicated by this switch, the model with larger probability determines the observation label at each time instant.It is shown that the method based on ECG dynamical model can be effectively used for AB detection. The detection performance is evaluated by comparing statistical metrics and the amount of time taken to detect AB compared with the annotated onset. The results demonstrate the superiority of this method, with sensitivity and specificity 94.74[Formula: see text] and 94.17[Formula: see text], respectively. The presented approaches may therefore serve as an effective algorithm for monitoring neonates suffering from AB. PMID:26235524

  2. Epileptic seizure onset detection based on EEG and ECG data fusion.

    PubMed

    Qaraqe, Marwa; Ismail, Muhammad; Serpedin, Erchin; Zulfi, Haneef

    2016-05-01

    This paper presents a novel method for seizure onset detection using fused information extracted from multichannel electroencephalogram (EEG) and single-channel electrocardiogram (ECG). In existing seizure detectors, the analysis of the nonlinear and nonstationary ECG signal is limited to the time-domain or frequency-domain. In this work, heart rate variability (HRV) extracted from ECG is analyzed using a Matching-Pursuit (MP) and Wigner-Ville Distribution (WVD) algorithm in order to effectively extract meaningful HRV features representative of seizure and nonseizure states. The EEG analysis relies on a common spatial pattern (CSP) based feature enhancement stage that enables better discrimination between seizure and nonseizure features. The EEG-based detector uses logical operators to pool SVM seizure onset detections made independently across different EEG spectral bands. Two fusion systems are adopted. In the first system, EEG-based and ECG-based decisions are directly fused to obtain a final decision. The second fusion system adopts an override option that allows for the EEG-based decision to override the fusion-based decision in the event that the detector observes a string of EEG-based seizure decisions. The proposed detectors exhibit an improved performance, with respect to sensitivity and detection latency, compared with the state-of-the-art detectors. Experimental results demonstrate that the second detector achieves a sensitivity of 100%, detection latency of 2.6s, and a specificity of 99.91% for the MAJ fusion case. PMID:27057745

  3. Switching Kalman filter based methods for apnea bradycardia detection from ECG signals.

    PubMed

    Montazeri Ghahjaverestan, Nasim; Shamsollahi, Mohammad B; Ge, Di; Hernández, Alfredo I

    2015-09-01

    Apnea bradycardia (AB) is an outcome of apnea occurrence in preterm infants and is an observable phenomenon in cardiovascular signals. Early detection of apnea in infants under monitoring is a critical challenge for the early intervention of nurses. In this paper, we introduce two switching Kalman filter (SKF) based methods for AB detection using electrocardiogram (ECG) signal.The first SKF model uses McSharry's ECG dynamical model integrated in two Kalman filter (KF) models trained for normal and AB intervals. Whereas the second SKF model is established by using only the RR sequence extracted from ECG and two AR models to be fitted in normal and AB intervals. In both SKF approaches, a discrete state variable called a switch is considered that chooses one of the models (corresponding to normal and AB) during the inference phase. According to the probability of each model indicated by this switch, the model with larger probability determines the observation label at each time instant.It is shown that the method based on ECG dynamical model can be effectively used for AB detection. The detection performance is evaluated by comparing statistical metrics and the amount of time taken to detect AB compared with the annotated onset. The results demonstrate the superiority of this method, with sensitivity and specificity 94.74[Formula: see text] and 94.17[Formula: see text], respectively. The presented approaches may therefore serve as an effective algorithm for monitoring neonates suffering from AB.

  4. Assessment of the exercise electrocardiogram in women versus men using tomographic myocardial perfusion imaging as the reference standard.

    PubMed

    Miller, T D; Roger, V L; Milavetz, J J; Hopfenspirger, M R; Milavetz, D L; Hodge, D O; Gibbons, R J

    2001-04-01

    The exercise electrocardiogram (ECG) is widely believed to be less accurate in women, primarily due to a high prevalence of false-positive tests. The purpose of this study was to examine the relative accuracy of the exercise ECG in women versus men in 8,671 patients (3,213 women, 5,458 men) using myocardial perfusion imaging as the reference standard. More women (14%) than men (10%) had a false-positive ECG (p <0.001), but the absolute difference was relatively small. The false-negative rate was considerably lower in women (17% vs 32%, p <0.001). Compared with men, women had lower test sensitivity (30% vs 42%, p <0.001) and positive predictive value (34% vs 70%, p <0.001) but higher specificity (82% vs 78%, p = 0.002), negative predictive value (78% vs 52%, p <0.001), and accuracy (69% vs 58%, p <0.001). In patients with a false-negative exercise ECG, "high-risk" scans were less prevalent in women (12% vs 19%, p <0.001). In the smaller subset of patients referred for coronary angiography (205 women, 838 men), the false-positive electrocardiographic rate was again higher in women (13% vs 7%, p = 0.003), but neither specificity (69% vs 74%, p = NS) nor accuracy (60% vs 66%, p = NS) was different between the sexes. Thus, the percentage of patients with a false-positive exercise ECG was higher in women than men but low in absolute terms (<15%) for both sexes. Test specificity was not lower in women. These results suggest that gender should not be a major determinant for selecting stress imaging over standard treadmill testing.

  5. Non-contact ECG monitoring

    NASA Astrophysics Data System (ADS)

    Smirnov, Alexey S.; Erlikh, Vadim V.; Kodkin, Vladimir L.; Keller, Andrei V.; Epishev, Vitaly V.

    2016-03-01

    The research is dedicated to non-contact methods of electrocardiography. The authors describe the routine of experimental procedure and suggest the approach to solving the problems which arise at indirect signal recording. The paper presents the results of experiments conducted by the authors, covers the flow charts of ECG recorders and reviews the drawbacks of filtering methods used in foreign equivalents.

  6. Comparison of three artificial models of the magnetohydrodynamic effect on the electrocardiogram.

    PubMed

    Oster, Julien; Llinares, Raul; Payne, Stephen; Tse, Zion Tsz Ho; Schmidt, Ehud Jeruham; Clifford, Gari D

    2015-01-01

    The electrocardiogram (ECG) is often acquired during magnetic resonance imaging (MRI), but its analysis is restricted by the presence of a strong artefact, called magnetohydrodynamic (MHD) effect. MHD effect is induced by the flow of electrically charged particles in the blood perpendicular to the static magnetic field, which creates a potential of the order of magnitude of the ECG and temporally coincident with the repolarisation period. In this study, a new MHD model is proposed by using MRI-based 4D blood flow measurements made across the aortic arch. The model is extended to several cardiac cycles to allow the simulation of a realistic ECG acquisition during MRI examination and the quality assessment of MHD suppression techniques. A comparison of two existing models, based, respectively, on an analytical solution and on a numerical method-based solution of the fluids dynamics problem, is made with the proposed model and with an estimate of the MHD voltage observed during a real MRI scan. Results indicate a moderate agreement between the proposed model and the estimated MHD model for most leads, with an average correlation factor of 0.47. However, the results demonstrate that the proposed model provides a closer approximation to the observed MHD effects and a better depiction of the complexity of the MHD effect compared with the previously published models, with an improved correlation (+5%), coefficient of determination (+22%) and fraction of energy (+1%) compared with the best previous model. The source code will be made freely available under an open source licence to facilitate collaboration and allow more rapid development of more accurate models of the MHD effect.

  7. A new technique for simultaneous monitoring of electrocardiogram and walking cadence

    NASA Technical Reports Server (NTRS)

    Hausdorff, J. M.; Forman, D. E.; Pilgrim, D. M.; Rigney, D. R.; Wei, J. Y.; Goldberger, A. L. (Principal Investigator)

    1992-01-01

    A new technique for simultaneously recording continuous electrocardiographic (ECG) data and walking step rate (cadence) is described. The ECG and gait signals are recorded on 2 channels of an ambulatory Holter monitor. Footfall is detected using ultrathin, force-sensitive foot switches and is frequency modulated. The footfall signal provides an indication of the subject's activity (walking or standing), as well as the instantaneous walking rate. Twenty-three young and elderly subjects were studied to demonstrate the use of this ECG and gait recorder. High-quality gait signals were obtained in all subjects, and the effects of walking on the electrocardiogram were assessed. Initial investigation revealed the following findings: (1) Although walking rates were similar in young and elderly subjects, the elderly had both decreased heart rate (HR) variability (p < 0.005) and increased cadence variability (p < 0.0001). (2) Overall, there was an inverse relation between HR and cadence variability (r = -0.73). Three elderly subjects with no known cardiac disease had HR and cadence variability similar to those of the young, whereas elderly subjects with history of congestive heart failure were among those with the lowest HR variability and the highest cadence variability. (3) Low-frequency (approximately equal to 0.1 Hz) HR oscillations (frequently observed during standing) persisted during walking in all young subjects. (4) In some subjects, both step rate and HR oscillated at the same low frequency (approximately equal to 0.1 Hz) previously identified with autonomic control of the baroreflex.(ABSTRACT TRUNCATED AT 250 WORDS).

  8. Measurement of ECG abnormalities and cardiovascular risk classification: a cohort study of primary care patients in the Netherlands

    PubMed Central

    Groot, Anne; Bots, Michiel L; Rutten, Frans H; den Ruijter, Hester M; Numans, Mattijs E; Vaartjes, Ilonca

    2015-01-01

    Background GPs need accurate tools for cardiovascular (CV) risk assessment. Abnormalities in resting electrocardiograms (ECGs) relate to increased CV risk. Aim To determine whether measurement of ECG abnormalities on top of established risk estimation (SCORE) improves CV risk classification in a primary care population. Design and setting A cohort study of patients enlisted with academic general practices in the Netherlands (the Utrecht Health Project [UHP]). Method Incident CV events were extracted from the GP records. MEANS algorithm was used to assess ECG abnormalities. Cox proportional hazards modelling was applied to relate ECG abnormalities to CV events. For a prediction model only with SCORE variables, and a model with SCORE+ECG abnormalities, the discriminative value (area under the receiver operator curve [AUC]) and the net reclassification improvement (NRI) were estimated. Results A total of 2370 participants aged 38–74 years were included, all eligible for CV risk assessment. During a mean follow-up of 7.8 years, 172 CV events occurred. In 19% of the participants at least one ECG abnormality was found (Lausanne criteria). Presence of atrial fibrillation/flutter (AF) and myocardial infarction (MI) were significantly related to CV events. The AUC of the SCORE risk factors was 0.75 (95% CI = 0.71 to 0.79). Addition of MI or AF resulted in an AUC of 0.76 (95% CI = 0.72 to 0.79) and 0.75 (95% CI = 0.72 to 0.79), respectively. The NRI with the addition of ECG abnormalities was small (MI 1.0%; 95% CI = −3.2% to 6.9%; AF 0.5%; 95% CI = −3.5% to 3.3%). Conclusion Performing a resting ECG in a primary care population does not seem to improve risk classification when SCORE information — age, sex, smoking, systolic blood pressure, and total cholesterol/HDL ratio — is already available. PMID:25548311

  9. Computer analysis of the exercise electrocardiogram and control of radionuclide ventriculography: an optimal statistical decision model for diagnosis of coronary artery disease

    SciTech Connect

    Hsia, P.W.E.

    1987-01-01

    A new automated technique for the diagnosis of coronary artery disease (CAD) by stress electrocardiography and radionuclide ventriculography (RNV) has been developed. The method employs digital signal processing of the electrocardiogram (ECG) for recognition of ischemic and arrhythmic events. On-line detection of abnormal beats is used for control image acquisition by the gamma camera resulting in improved image quality since only identical beats are included in the composite images of the cardiac cycle. A combined stress ECG analysis which measures ST changes indicative of ischemia, and radionuclide results, which reveal corresponding ejection fraction abnormalities yields greater sensitivity and specificity than either test alone. Digitized data from the electrocardiogram are analyzed in a beat-by-beat mode and a contextual diagnosis of underlying rhythm is given. Template generation, R wave detection, QRS window size, baseline correction, and continuous updating of heart rate are completely automated. A statistical model base on computerized ST segment measurements combined with radionuclide ventriculography data has been developed by using a logistic model with stepwise regression fitting. A previously acquired database of similar measurements was used for designing the model. The most significant parameters were found to be (1) ejection fraction of exercise RNV; (2) difference of ST level between exercise and resting test (stdif); and (3) ejection fraction difference between exercise and resting test. The new parameter stdif, not previously used in ECG interpretation, was found to be of great diagnostic significance.

  10. Independent Prognostic Value of Single and Multiple Non-Specific 12-Lead Electrocardiographic Findings for Long-Term Cardiovascular Outcomes: A Prospective Cohort Study

    PubMed Central

    Sawano, Mitsuaki; Kohsaka, Shun; Okamura, Tomonori; Inohara, Taku; Sugiyama, Daisuke; Shiraishi, Yasuyuki; Watanabe, Makoto; Nakamura, Yasuyuki; Higashiyama, Aya; Kadota, Aya; Okuda, Nagako; Murakami, Yoshitaka; Ohkubo, Takayoshi; Fujiyoshi, Akira; Miura, Katsuyuki; Okayama, Akira; Ueshima, Hirotsugu

    2016-01-01

    Aims The long-term prognostic effect of non-specific 12-lead electrocardiogram findings is unknown. We aimed to evaluate the cumulative prognostic impact of axial, structural, and repolarization categorical abnormalities on cardiovascular death, independent from traditional risk scoring systems such as the Framingham risk score and the NIPPON DATA80 risk chart. Methods and Results A total of 16,816 healthy men and women from two prospective, longitudinal cohort studies were evaluated. 3,794 (22.6%) individuals died during a median follow-up of 15 years (range, 2.0–24 years). Hazard ratios for cardiovascular death, all-cause death, coronary death and stroke death were calculated for the cumulative and independent axial, structural, and repolarization categorical abnormalities adjusted for the Framingham risk score and the NIPPON DATA80 risk chart. Individuals with two or more abnormal categories had a higher risk of cardiovascular death after adjustment for Framingham risk score (men: HR 4.27, 95%CI 3.35–5.45; women: HR 4.83, 95%CI 3.76–6.22) and NIPPON DATA80 risk chart (men: HR 2.39, 95%CI 1.87–3.07; women: HR 2.04, 95%CI 1.58–2.64). Conclusion Cumulative findings of axial, structural, and repolarization abnormalities are significant predictors of long-term cardiovascular death in asymptomatic, healthy individuals independent of traditional risk stratification systems. PMID:27362562

  11. A comparative study of two techniques (electrocardiogram- and landmark-guided) for correct depth of the central venous catheter placement in paediatric patients undergoing elective cardiovascular surgery

    PubMed Central

    Barnwal, Neeraj Kumar; Dave, Sona T; Dias, Raylene

    2016-01-01

    Background and Aims: The complications of central venous catheterisation can be minimized by ensuring catheter tip placement just above the superior vena cava-right atrium junction. We aimed to compare two methods, using an electrocardiogram (ECG) or landmark as guides, for assessing correct depth of central venous catheter (CVC) placement. Methods: In a prospective randomised study of sixty patients of <12 years of age, thirty patients each were allotted randomly to two groups (ECG and landmark). After induction, central venous catheterisation was performed by either of the two techniques and position of CVC tip was compared in post-operative chest X-ray with respect to carina. Unpaired t-test was used for quantitative data and Chi-square test was used for qualitative data. Results: In ECG group, positions of CVC tip were above carina in 12, at carina in 9 and below carina in 9 patients. In landmark group, the positions of CVC tips were above carina in 10, at carina in 4 and below carina in 16 patients. Mean distance of CVC tip in ECG group was 0.34 ± 0.23 cm and 0.66 ± 0.35 cm in landmark group (P = 0.0001). Complications occurred in one patient in ECG group and in nine patients in landmark group (P = 0.0056). Conclusion: Overall, landmark-guided technique was comparable with ECG technique. ECG-guided technique was more precise for CVC tip placement closer to carina. The incidence of complications was more in the landmark group. PMID:27512162

  12. Electrocardiogram classification using delay differential equations

    NASA Astrophysics Data System (ADS)

    Lainscsek, Claudia; Sejnowski, Terrence J.

    2013-06-01

    Time series analysis with nonlinear delay differential equations (DDEs) reveals nonlinear as well as spectral properties of the underlying dynamical system. Here, global DDE models were used to analyze 5 min data segments of electrocardiographic (ECG) recordings in order to capture distinguishing features for different heart conditions such as normal heart beat, congestive heart failure, and atrial fibrillation. The number of terms and delays in the model as well as the order of nonlinearity of the model have to be selected that are the most discriminative. The DDE model form that best separates the three classes of data was chosen by exhaustive search up to third order polynomials. Such an approach can provide deep insight into the nature of the data since linear terms of a DDE correspond to the main time-scales in the signal and the nonlinear terms in the DDE are related to nonlinear couplings between the harmonic signal parts. The DDEs were able to detect atrial fibrillation with an accuracy of 72%, congestive heart failure with an accuracy of 88%, and normal heart beat with an accuracy of 97% from 5 min of ECG, a much shorter time interval than required to achieve comparable performance with other methods.

  13. [Usefulness of vector analysis of the electrocardiogram].

    PubMed

    de Micheli, A; Medrano, G A

    2001-01-01

    An electrocardiogram corresponding to an obese, hypertensive woman 52 years old, is presented. It shows a left bundle branch block of advanced degree and the AQRSF at 70 degrees. In this case, the key of the electrocardiographic diagnosis is that the second vector originated by depolarization of the lower left septal mass is oriented downward, which is unusual in the presence of left bundle branch block. This fact may be due to a marked clockwise rotation. Therefore, it is possible that right ventricle pathologic conditions be associated to those involving the left ventricle. Cardiopulmonary tests determined the existence of a chronic pulmonary emphysema. Furthermore the study of this case shows the usefulness of vectorcardiographic exploration in clinical practice. PMID:11665661

  14. An Energy efficient application specific integrated circuit for electrocardiogram feature detection and its potential for ambulatory cardiovascular disease detection.

    PubMed

    Jain, Sanjeev Kumar; Bhaumik, Basabi

    2016-03-01

    A novel algorithm based on forward search is developed for real-time electrocardiogram (ECG) signal processing and implemented in application specific integrated circuit (ASIC) for QRS complex related cardiovascular disease diagnosis. The authors have evaluated their algorithm using MIT-BIH database and achieve sensitivity of 99.86% and specificity of 99.93% for QRS complex peak detection. In this Letter, Physionet PTB diagnostic ECG database is used for QRS complex related disease detection. An ASIC for cardiovascular disease detection is fabricated using 130-nm CMOS high-speed process technology. The area of the ASIC is 0.5 mm(2). The power dissipation is 1.73 μW at the operating frequency of 1 kHz with a supply voltage of 0.6 V. The output from the ASIC is fed to their Android application that generates diagnostic report and can be sent to a cardiologist through email. Their ASIC result shows average failed detection rate of 0.16% for six leads data of 290 patients in PTB diagnostic ECG database. They also have implemented a low-leakage version of their ASIC. The ASIC dissipates only 45 pJ with a supply voltage of 0.9 V. Their proposed ASIC is most suitable for energy efficient telemetry cardiovascular disease detection system. PMID:27284458

  15. An Energy efficient application specific integrated circuit for electrocardiogram feature detection and its potential for ambulatory cardiovascular disease detection.

    PubMed

    Jain, Sanjeev Kumar; Bhaumik, Basabi

    2016-03-01

    A novel algorithm based on forward search is developed for real-time electrocardiogram (ECG) signal processing and implemented in application specific integrated circuit (ASIC) for QRS complex related cardiovascular disease diagnosis. The authors have evaluated their algorithm using MIT-BIH database and achieve sensitivity of 99.86% and specificity of 99.93% for QRS complex peak detection. In this Letter, Physionet PTB diagnostic ECG database is used for QRS complex related disease detection. An ASIC for cardiovascular disease detection is fabricated using 130-nm CMOS high-speed process technology. The area of the ASIC is 0.5 mm(2). The power dissipation is 1.73 μW at the operating frequency of 1 kHz with a supply voltage of 0.6 V. The output from the ASIC is fed to their Android application that generates diagnostic report and can be sent to a cardiologist through email. Their ASIC result shows average failed detection rate of 0.16% for six leads data of 290 patients in PTB diagnostic ECG database. They also have implemented a low-leakage version of their ASIC. The ASIC dissipates only 45 pJ with a supply voltage of 0.9 V. Their proposed ASIC is most suitable for energy efficient telemetry cardiovascular disease detection system.

  16. An Energy efficient application specific integrated circuit for electrocardiogram feature detection and its potential for ambulatory cardiovascular disease detection

    PubMed Central

    Bhaumik, Basabi

    2016-01-01

    A novel algorithm based on forward search is developed for real-time electrocardiogram (ECG) signal processing and implemented in application specific integrated circuit (ASIC) for QRS complex related cardiovascular disease diagnosis. The authors have evaluated their algorithm using MIT-BIH database and achieve sensitivity of 99.86% and specificity of 99.93% for QRS complex peak detection. In this Letter, Physionet PTB diagnostic ECG database is used for QRS complex related disease detection. An ASIC for cardiovascular disease detection is fabricated using 130-nm CMOS high-speed process technology. The area of the ASIC is 0.5 mm2. The power dissipation is 1.73 μW at the operating frequency of 1 kHz with a supply voltage of 0.6 V. The output from the ASIC is fed to their Android application that generates diagnostic report and can be sent to a cardiologist through email. Their ASIC result shows average failed detection rate of 0.16% for six leads data of 290 patients in PTB diagnostic ECG database. They also have implemented a low-leakage version of their ASIC. The ASIC dissipates only 45 pJ with a supply voltage of 0.9 V. Their proposed ASIC is most suitable for energy efficient telemetry cardiovascular disease detection system. PMID:27284458

  17. Therapeutic efficacy of intensified walk training under the electrocardiogram telemetry in stroke induced lower limb dysfunction patients with heart failure

    PubMed Central

    Shen, Dantong; Huang, Huai; Yuan, Hui; Ye, Shuilin; Li, Min; Gu, Jing; Wang, Zhiwei

    2015-01-01

    Objectives: This study aimed to explore the therapeutic efficacy of intensified walk training under the electrocardiogram (ECG) telemetry in stroke induced lower limb dysfunction patients with heart failure. Material and Methods: A total of 40 patients with stroke induced lower limb dysfunction and heart failure were randomized into control group and walk training group (n=20 per group). Besides comprehensive rehabilitation, patients in walk training group received intensified walk training under the ECG telemetry and patients in control group received traditional training. After 5-week treatment, the FMA score of lower limbs, ADL score, 6-min walking distance and left ventricular ejection fraction (EF) by heart ultrasonography were determined. Results: There were no marked differences in the demographics between two groups at baseline, and no severe complications were observed during training in the walk training group. In control group, 6 patients developed lung edema which required further therapy. After 5-week training, the FMA score of lower limbs, ADL score and 6-min walk distance were improved to different extents, but the improvement was more obvious in walk training group (P<0.05). The left ventricular EF remained unchanged in both groups. Conclusions: In patients with stroke induced lower limb dysfunction and heart failure, routine rehabilitation in combination with additional walk training under the ECG telemetry is helpful to increase the training efficiency and training intensity and improve the low limb function and walk distance when the safety is assured. PMID:26629190

  18. Cost-effectiveness of pre-participation screening of athletes with ECG in Europe and Algeria.

    PubMed

    Assanelli, Deodato; Levaggi, Rosella; Carré, François; Sharma, Sanjay; Deligiannis, Asterios; Mellwig, Klaus Peter; Tahmi, Mohamed; Vinetti, Giovanni; Aliverti, Paola

    2015-03-01

    The aim of this study is to evaluate the cost-effectiveness of ECG in combination with family and personal history and physical examination in order to detect cardiovascular diseases that might cause sudden death in athletes. The study was conducted on a cohort of 6,634, mainly young professional and recreational athletes, 1,071 from Algeria and 5,563 from Europe (France, Germany and Greece). Each athlete underwent medical history, physical examination, and resting 12-lead ECG. 293 athletes (4.4 %), 149 in Europe (2.7 %) and 144 in Algeria (13.4 %) required further tests, and 56 were diagnosed with cardiovascular disease and thus disqualified. The cost-effectiveness ratio (CER) was calculated as the ratio between the cost of screening and the number of statistical life-years saved by the intervention. The estimated reduced risk of death deriving from treatment or disqualification resulted in the saving of 79.1 statistical life-years in Europe and 136.3 in Algeria. CER of screening was 4,071 purchasing-power-parity-adjusted US dollars ($PPP) in Europe and 582 $PPP in Algeria. The results of this study strongly support the utilisation of 12-lead ECG in the pre-participation screening of young athletes, especially in countries where secondary preventive care is not highly developed.

  19. Implementation of a wireless ECG acquisition SoC for IEEE 802.15.4 (ZigBee) applications.

    PubMed

    Wang, Liang-Hung; Chen, Tsung-Yen; Lin, Kuang-Hao; Fang, Qiang; Lee, Shuenn-Yuh

    2015-01-01

    This paper presents a wireless biosignal acquisition system-on-a-chip (WBSA-SoC) specialized for electrocardiogram (ECG) monitoring. The proposed system consists of three subsystems, namely, 1) the ECG acquisition node, 2) the protocol for standard IEEE 802.15.4 ZigBee system, and 3) the RF transmitter circuits. The ZigBee protocol is adopted for wireless communication to achieve high integration, applicability, and portability. A fully integrated CMOS RF front end containing a quadrature voltage-controlled oscillator and a 2.4-GHz low-IF (i.e., zero-IF) transmitter is employed to transmit ECG signals through wireless communication. The low-power WBSA-SoC is implemented by the TSMC 0.18-μm standard CMOS process. An ARM-based displayer with FPGA demodulation and an RF receiver with analog-to-digital mixed-mode circuits are constructed as verification platform to demonstrate the wireless ECG acquisition system. Measurement results on the human body show that the proposed SoC can effectively acquire ECG signals.

  20. A Novel Algorithm for Movement Artifact Removal in ECG Signals Acquired from Wearable Systems Applied to Horses.

    PubMed

    Lanata, Antonio; Guidi, Andrea; Baragli, Paolo; Valenza, Gaetano; Scilingo, Enzo Pasquale

    2015-01-01

    This study reports on a novel method to detect and reduce the contribution of movement artifact (MA) in electrocardiogram (ECG) recordings gathered from horses in free movement conditions. We propose a model that integrates cardiovascular and movement information to estimate the MA contribution. Specifically, ECG and physical activity are continuously acquired from seven horses through a wearable system. Such a system employs completely integrated textile electrodes to monitor ECG and is also equipped with a triaxial accelerometer for movement monitoring. In the literature, the most used technique to remove movement artifacts, when noise bandwidth overlaps the primary source bandwidth, is the adaptive filter. In this study we propose a new algorithm, hereinafter called Stationary Wavelet Movement Artifact Reduction (SWMAR), where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG signals in horses. A comparative analysis with the Normalized Least Mean Square Adaptive Filter technique (NLMSAF) is performed as well. Results achieved on seven hours of recordings showed a reduction greater than 40% of MA percentage (between before- and after- the application of the proposed algorithm). Moreover, the comparative analysis with the NLMSAF, applied to the same ECG recordings, showed a greater reduction of MA percentage in favour of SWMAR with a statistical significant difference (p-value < 0.0.5). PMID:26484686

  1. A Novel Algorithm for Movement Artifact Removal in ECG Signals Acquired from Wearable Systems Applied to Horses

    PubMed Central

    Lanata, Antonio; Guidi, Andrea; Baragli, Paolo; Valenza, Gaetano; Scilingo, Enzo Pasquale

    2015-01-01

    This study reports on a novel method to detect and reduce the contribution of movement artifact (MA) in electrocardiogram (ECG) recordings gathered from horses in free movement conditions. We propose a model that integrates cardiovascular and movement information to estimate the MA contribution. Specifically, ECG and physical activity are continuously acquired from seven horses through a wearable system. Such a system employs completely integrated textile electrodes to monitor ECG and is also equipped with a triaxial accelerometer for movement monitoring. In the literature, the most used technique to remove movement artifacts, when noise bandwidth overlaps the primary source bandwidth, is the adaptive filter. In this study we propose a new algorithm, hereinafter called Stationary Wavelet Movement Artifact Reduction (SWMAR), where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG signals in horses. A comparative analysis with the Normalized Least Mean Square Adaptive Filter technique (NLMSAF) is performed as well. Results achieved on seven hours of recordings showed a reduction greater than 40% of MA percentage (between before- and after- the application of the proposed algorithm). Moreover, the comparative analysis with the NLMSAF, applied to the same ECG recordings, showed a greater reduction of MA percentage in favour of SWMAR with a statistical significant difference (p–value < 0.0.5). PMID:26484686

  2. A Novel Algorithm for Movement Artifact Removal in ECG Signals Acquired from Wearable Systems Applied to Horses.

    PubMed

    Lanata, Antonio; Guidi, Andrea; Baragli, Paolo; Valenza, Gaetano; Scilingo, Enzo Pasquale

    2015-01-01

    This study reports on a novel method to detect and reduce the contribution of movement artifact (MA) in electrocardiogram (ECG) recordings gathered from horses in free movement conditions. We propose a model that integrates cardiovascular and movement information to estimate the MA contribution. Specifically, ECG and physical activity are continuously acquired from seven horses through a wearable system. Such a system employs completely integrated textile electrodes to monitor ECG and is also equipped with a triaxial accelerometer for movement monitoring. In the literature, the most used technique to remove movement artifacts, when noise bandwidth overlaps the primary source bandwidth, is the adaptive filter. In this study we propose a new algorithm, hereinafter called Stationary Wavelet Movement Artifact Reduction (SWMAR), where the Stationary Wavelet Transform (SWT) decomposition algorithm is employed to identify and remove movement artifacts from ECG signals in horses. A comparative analysis with the Normalized Least Mean Square Adaptive Filter technique (NLMSAF) is performed as well. Results achieved on seven hours of recordings showed a reduction greater than 40% of MA percentage (between before- and after- the application of the proposed algorithm). Moreover, the comparative analysis with the NLMSAF, applied to the same ECG recordings, showed a greater reduction of MA percentage in favour of SWMAR with a statistical significant difference (p-value < 0.0.5).

  3. Compression of ECG signals using variable-length classifıed vector sets and wavelet transforms

    NASA Astrophysics Data System (ADS)

    Gurkan, Hakan

    2012-12-01

    In this article, an improved and more efficient algorithm for the compression of the electrocardiogram (ECG) signals is presented, which combines the processes of modeling ECG signal by variable-length classified signature and envelope vector sets (VL-CSEVS), and residual error coding via wavelet transform. In particular, we form the VL-CSEVS derived from the ECG signals, which exploits the relationship between energy variation and clinical information. The VL-CSEVS are unique patterns generated from many of thousands of ECG segments of two different lengths obtained by the energy based segmentation method, then they are presented to both the transmitter and the receiver used in our proposed compression system. The proposed algorithm is tested on the MIT-BIH Arrhythmia Database and MIT-BIH Compression Test Database and its performance is evaluated by using some evaluation metrics such as the percentage root-mean-square difference (PRD), modified PRD (MPRD), maximum error, and clinical evaluation. Our experimental results imply that our proposed algorithm achieves high compression ratios with low level reconstruction error while preserving the diagnostic information in the reconstructed ECG signal, which has been supported by the clinical tests that we have carried out.

  4. [Clinical evaluation of ECG at the onset subjective symptoms using real-time analysis electrocardiograph (event recorder)].

    PubMed

    Takizawa, Yoshinori; Shimetani, Naoto; Uchiyama, Kenji; Takayanagi, Kan; Mori, Mikio

    2005-05-01

    Examination of patient complaining of palpitation, chest pain and chest discomfort is usually performed by 12-lead electrocardiograph. However, the recording time is short and there are few opportunities to capture an ECG demonstrating conditions during subjective symptoms. To investigate the cause, we need to obtain an ECG during subjective symptoms. Thus, we frequently use a Holter ECG, which can be recorded for 24 hours. However, some patients have a low frequency of subjective symptoms, which may not appear during a 24-hour examination. We used a real-time electrocardiograph (Event Recorder CG-6106 made by Card Guard Scientific Survival Limited) as a monitor during subjective symptoms. Thereafter, ECG findings at the onset of subjective symptoms could be analyzed in 30 patients who did not have a clear cardiac disease. In this examination, arrhythmia was recorded in 25 of 30 cases. Although in these cases ECG during subjective symptoms could not be captured even when Holter examination was performed several times ECG during subjective symptoms was captured using an Event Recorder. This method using an Event Recorder is simple and convenient, moreover, is considered very useful for investigation of subjective symptoms. In the future, the use of an Event Recorder for heart-health-care in the daily life of healthy people and/or cardiac disease patient is highly anticipated.

  5. ECG-ELECTRODE INDUCED HYPOPIGMENTATION.

    PubMed

    Tripi, Paul A; Parthasarathy, Supraja N; Honda, Kord

    2016-06-01

    Skin reactions following the application of electrocardiography (ECG) electrodes have been reported in adults and children, and are postulated to result from contact with the conductive gel or adhesive used on the electrodes. Although contact dermatitis is the usual cause of such reactions, contact depigmentation or hypopigmentation may also occur. We report a case of hypopigmentation in a healthy boy following continuous electrocardiography monitoring during general anesthesia for dental rehabilitation.

  6. ECG-ELECTRODE INDUCED HYPOPIGMENTATION.

    PubMed

    Tripi, Paul A; Parthasarathy, Supraja N; Honda, Kord

    2016-06-01

    Skin reactions following the application of electrocardiography (ECG) electrodes have been reported in adults and children, and are postulated to result from contact with the conductive gel or adhesive used on the electrodes. Although contact dermatitis is the usual cause of such reactions, contact depigmentation or hypopigmentation may also occur. We report a case of hypopigmentation in a healthy boy following continuous electrocardiography monitoring during general anesthesia for dental rehabilitation. PMID:27487645

  7. Adaptive Fourier decomposition based ECG denoising.

    PubMed

    Wang, Ze; Wan, Feng; Wong, Chi Man; Zhang, Liming

    2016-10-01

    A novel ECG denoising method is proposed based on the adaptive Fourier decomposition (AFD). The AFD decomposes a signal according to its energy distribution, thereby making this algorithm suitable for separating pure ECG signal and noise with overlapping frequency ranges but different energy distributions. A stop criterion for the iterative decomposition process in the AFD is calculated on the basis of the estimated signal-to-noise ratio (SNR) of the noisy signal. The proposed AFD-based method is validated by the synthetic ECG signal using an ECG model and also real ECG signals from the MIT-BIH Arrhythmia Database both with additive Gaussian white noise. Simulation results of the proposed method show better performance on the denoising and the QRS detection in comparing with major ECG denoising schemes based on the wavelet transform, the Stockwell transform, the empirical mode decomposition, and the ensemble empirical mode decomposition.

  8. The maximal exercise ECG in asymptomatic men.

    PubMed

    Cumming, G R; Borysyk, L; Dufresne, C

    1972-03-18

    Lead MC5 bipolar exercise ECG was obtained in 510 asymptomatic males, aged 40 to 65, utilizing the bicycle ergometer, with maximal stress in 71% of the subjects. "Ischemic changes" occurred in 61 subjects, the frequency increasing from 4% at age 40 to 45, to 20% at age 50 to 55, to 37% at age 61 to 65. Subjects having an ischemic type ECG change on exercise had more frequent minor resting ECG changes, more resting hypertension, and a greater incidence of high cholesterol values than subjects with a normal ECG response to exercise, but there was no difference in the incidence of obesity, low fitness, or high systolic blood pressure after exercise. Current evidence suggests that asymptomatic male subjects with an abnormal exercise ECG develop clinical coronary heart disease from 2.5 to over 30 times more frequently than those with a normal exercise ECG.

  9. ECG Morphological Variability in Beat Space for Risk Stratification After Acute Coronary Syndrome

    PubMed Central

    Liu, Yun; Syed, Zeeshan; Scirica, Benjamin M.; Morrow, David A.; Guttag, John V.; Stultz, Collin M.

    2014-01-01

    Background Identification of patients who are at high risk of adverse cardiovascular events after an acute coronary syndrome (ACS) remains a major challenge in clinical cardiology. We hypothesized that quantifying variability in electrocardiogram (ECG) morphology may improve risk stratification post‐ACS. Methods and Results We developed a new metric to quantify beat‐to‐beat morphologic changes in the ECG: morphologic variability in beat space (MVB), and compared our metric to published ECG metrics (heart rate variability [HRV], deceleration capacity [DC], T‐wave alternans, heart rate turbulence, and severe autonomic failure). We tested the ability of these metrics to identify patients at high risk of cardiovascular death (CVD) using 1082 patients (1‐year CVD rate, 4.5%) from the MERLIN‐TIMI 36 (Metabolic Efficiency with Ranolazine for Less Ischemia in Non‐ST‐Elevation Acute Coronary Syndrome—Thrombolysis in Myocardial Infarction 36) clinical trial. DC, HRV/low frequency–high frequency, and MVB were all associated with CVD (hazard ratios [HRs] from 2.1 to 2.3 [P<0.05 for all] after adjusting for the TIMI risk score [TRS], left ventricular ejection fraction [LVEF], and B‐type natriuretic peptide [BNP]). In a cohort with low‐to‐moderate TRS (N=864; 1‐year CVD rate, 2.7%), only MVB was significantly associated with CVD (HR, 3.0; P=0.01, after adjusting for LVEF and BNP). Conclusions ECG morphological variability in beat space contains prognostic information complementary to the clinical variables, LVEF and BNP, in patients with low‐to‐moderate TRS. ECG metrics could help to risk stratify patients who might not otherwise be considered at high risk of CVD post‐ACS. PMID:24963105

  10. An algorithm for sleep apnea detection from single-lead ECG using Hermite basis functions.

    PubMed

    Sharma, Hemant; Sharma, K K

    2016-10-01

    This paper introduces a methodology for the detection of sleep apnea based on single-lead electrocardiogram (ECG) of the patient. In the proposed technique, each QRS complex of the ECG signal is approximated using a linear combination of the lower order Hermite basis functions. The coefficients of the Hermite expansion are then used to discriminate the apnea and normal segments along with three features based on R-R time series (mean of R-R intervals, the standard deviation of R-R intervals) and energy in the error of the QRS approximation. To perform classification between the apnea and normal segments, four different types of classifiers (K-nearest neighbor (KNN), multilayer perceptron neural network (MLPNN), support vector machine (SVM), and least-square support vector machine (LS-SVM)) are used in this work. In total, 70 ECG recordings from Apnea-ECG dataset are used in this study and the performance of the proposed algorithm is evaluated based on the minute-by-minute (per-segment) classification, and per-recording (where the entire ECG recording of a subject is discriminated as the apnea or normal one) classification. By considering the events of apnea and hypopnea together, an accuracy of about 84% is achieved on the minute-by-minute basis classification using the LS-SVM classifier with the Gaussian radial basis function (RBF) kernel. On the other hand, an accuracy of about 97.14% is achieved for per-recording classification using the SVM, and LS-SVM classifiers. From the results, it is observed that the proposed methodology provides comparable accuracy with the methods existing in the literature at reduced computational cost due to the lesser number of features selected for the classification. PMID:27543782

  11. Capsular contracture simulating myocardial infarction on ECG.

    PubMed

    Peters, W; McEwan, P

    1993-03-01

    A patient is presented with severe bilateral class IV capsular contractures who presented 16 years after prepectoral breast augmentation with a "septal infarct" pattern on ECG. This abnormal ECG proved to be an artifact caused by unavoidable misplacement of the V2 and V3 leads because of the severe capsular contracture. Following open capsulotomy, normal anatomic lead placement was possible, and a normal ECG was produced.

  12. Atrial fibrillation disorganization is reduced by catheter ablation: a standard ECG study.

    PubMed

    Bonizzi, Pietro; Meste, Olivier; Zarzoso, Vicente; Latcu, Decebal Gabriel; Popescu, Irina; Ricard, Philippe; Saoudi, Nadir

    2010-01-01

    Selection of candidates to catheter ablation (CA) of long-lasting persistent atrial fibrillation (AF) is challenging, since success is not guaranteed. In this study, we put forward an automated method for noninvasively evaluating the reduction of the complexity of the AF organization following CA. Complexity is meant as the amount of disorganization observed on the ECG, supposed to be directly correlated to the number and interactions of atrial wavefronts. By means of PCA, the complexity of the AF organization is evaluated quantitatively from a 12-lead ECG recording. Preliminary results show that CA is able to reduce the complexity of AF organization in the atrial wavefront pattern propagation, despite the persistence of AF in most cases. This can be viewed as a first clinical validation of this parameter. Whether AF complexity and its reduction by CA are predictive of long-term outcome is thus still to be determined.

  13. Nonlinear adaptive wavelet analysis of electrocardiogram signals

    NASA Astrophysics Data System (ADS)

    Yang, H.; Bukkapatnam, S. T.; Komanduri, R.

    2007-08-01

    Wavelet representation can provide an effective time-frequency analysis for nonstationary signals, such as the electrocardiogram (EKG) signals, which contain both steady and transient parts. In recent years, wavelet representation has been emerging as a powerful time-frequency tool for the analysis and measurement of EKG signals. The EKG signals contain recurring, near-periodic patterns of P , QRS , T , and U waveforms, each of which can have multiple manifestations. Identification and extraction of a compact set of features from these patterns is critical for effective detection and diagnosis of various disorders. This paper presents an approach to extract a fiducial pattern of EKG based on the consideration of the underlying nonlinear dynamics. The pattern, in a nutshell, is a combination of eigenfunctions of the ensembles created from a Poincare section of EKG dynamics. The adaptation of wavelet functions to the fiducial pattern thus extracted yields two orders of magnitude (some 95%) more compact representation (measured in terms of Shannon signal entropy). Such a compact representation can facilitate in the extraction of features that are less sensitive to extraneous noise and other variations. The adaptive wavelet can also lead to more efficient algorithms for beat detection and QRS cancellation as well as for the extraction of multiple classical EKG signal events, such as widths of QRS complexes and QT intervals.

  14. Electrocardiogram abnormalities in captive chimpanzees (Pan troglodytes).

    PubMed

    Doane, Cynthia J; Lee, D Rick; Sleeper, Meg M

    2006-12-01

    Although cardiovascular disease is the leading cause of death in the captive chimpanzee population, little is known about the prevalence and etiology of heart disease in this species. We reviewed the physical exam records of 265 common chimpanzees (Pan troglodytes) for electrocardiogram abnormalities. During the 24-mo period reviewed (August 2003 through August 2005), 34 animals were diagnosed with cardiac arrhythmias consisting of ventricular arrhythmias, supraventricular arrhythmias, conduction disturbances, mixed arrhythmias, and bradycardia. The incidence of cardiac arrhythmia was significantly higher in male animals, chimpanzees 20 to 39 y old, and those with structural heart disease. Incidence of cardiac arrhythmia was not significantly higher in animals with hypertension, hyperlipidemia, or chronic viral infections. During the retrospective period, 7 animals with cardiac arrhythmias died or were euthanized. Mortality was significantly higher in animals with ventricular arrhythmias compared with those without ventricular arrhythmias. We conclude that in the common chimpanzee, age, male gender, and structural heart disease are risk factors for developing cardiac arrhythmias and that ventricular arrhythmias are risk factors for mortality. PMID:17219782

  15. Biotelemetry for Monitoring Electrocardiograms during Athletic Events and Stress Tests

    ERIC Educational Resources Information Center

    Mitchell, B. W.; Thomasson, G. O.

    1975-01-01

    This article discusses a study attempting to determine if a biotelemetry system developed for use on chickens could be suitable for monitoring electrocardiograms of humans during exercise. Techniques for its use are reviewed. (JS)

  16. Graphite Based Electrode for ECG Monitoring: Evaluation under Freshwater and Saltwater Conditions

    PubMed Central

    Thap, Tharoeun; Yoon, Kwon-Ha; Lee, Jinseok

    2016-01-01

    We proposed new electrodes that are applicable for electrocardiogram (ECG) monitoring under freshwater- and saltwater-immersion conditions. Our proposed electrodes are made of graphite pencil lead (GPL), a general-purpose writing pencil. We have fabricated two types of electrode: a pencil lead solid type (PLS) electrode and a pencil lead powder type (PLP) electrode. In order to assess the qualities of the PLS and PLP electrodes, we compared their performance with that of a commercial Ag/AgCl electrode, under a total of seven different conditions: dry, freshwater immersion with/without movement, post-freshwater wet condition, saltwater immersion with/without movement, and post-saltwater wet condition. In both dry and post-freshwater wet conditions, all ECG-recorded PQRST waves were clearly discernible, with all types of electrodes, Ag/AgCl, PLS, and PLP. On the other hand, under the freshwater- and saltwater-immersion conditions with/without movement, as well as post-saltwater wet conditions, we found that the proposed PLS and PLP electrodes provided better ECG waveform quality, with significant statistical differences compared with the quality provided by Ag/AgCl electrodes. PMID:27092502

  17. Design of Secure ECG-Based Biometric Authentication in Body Area Sensor Networks.

    PubMed

    Peter, Steffen; Reddy, Bhanu Pratap; Momtaz, Farshad; Givargis, Tony

    2016-04-22

    Body area sensor networks (BANs) utilize wireless communicating sensor nodes attached to a human body for convenience, safety, and health applications. Physiological characteristics of the body, such as the heart rate or Electrocardiogram (ECG) signals, are promising means to simplify the setup process and to improve security of BANs. This paper describes the design and implementation steps required to realize an ECG-based authentication protocol to identify sensor nodes attached to the same human body. Therefore, the first part of the paper addresses the design of a body-area sensor system, including the hardware setup, analogue and digital signal processing, and required ECG feature detection techniques. A model-based design flow is applied, and strengths and limitations of each design step are discussed. Real-world measured data originating from the implemented sensor system are then used to set up and parametrize a novel physiological authentication protocol for BANs. The authentication protocol utilizes statistical properties of expected and detected deviations to limit the number of false positive and false negative authentication attempts. The result of the described holistic design effort is the first practical implementation of biometric authentication in BANs that reflects timing and data uncertainties in the physical and cyber parts of the system.

  18. A New Strategy for ECG Baseline Wander Elimination Using Empirical Mode Decomposition

    NASA Astrophysics Data System (ADS)

    Shahbakhti, Mohammad; Bagheri, Hamed; Shekarchi, Babak; Mohammadi, Somayeh; Naji, Mohsen

    2016-06-01

    Electrocardiogram (ECG) signals might be affected by various artifacts and noises that have biological and external sources. Baseline wander (BW) is a low-frequency artifact that may be caused by breathing, body movements and loose sensor contact. In this paper, a novel method based on empirical mode decomposition (EMD) for removal of baseline noise from ECG is presented. When compared to other EMD-based methods, the novelty of this research is to reach the optimized number of decomposed levels for ECG BW de-noising using mean power frequency (MPF), while the reduction of processing time is considered. To evaluate the performance of the proposed method, a fifth-order Butterworth high pass filtering (BHPF) with cut-off frequency at 0.5Hz and wavelet approach are applied. Three performance indices, signal-to-noise ratio (SNR), mean square error (MSE) and correlation coefficient (CC), between pure and filtered signals have been utilized for qualification of presented techniques. Results suggest that the EMD-based method outperforms the other filtering method.

  19. Mobile Cloud-Computing-Based Healthcare Service by Noncontact ECG Monitoring

    PubMed Central

    Fong, Ee-May; Chung, Wan-Young

    2013-01-01

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service. PMID:24316562

  20. Design of Secure ECG-Based Biometric Authentication in Body Area Sensor Networks.

    PubMed

    Peter, Steffen; Reddy, Bhanu Pratap; Momtaz, Farshad; Givargis, Tony

    2016-01-01

    Body area sensor networks (BANs) utilize wireless communicating sensor nodes attached to a human body for convenience, safety, and health applications. Physiological characteristics of the body, such as the heart rate or Electrocardiogram (ECG) signals, are promising means to simplify the setup process and to improve security of BANs. This paper describes the design and implementation steps required to realize an ECG-based authentication protocol to identify sensor nodes attached to the same human body. Therefore, the first part of the paper addresses the design of a body-area sensor system, including the hardware setup, analogue and digital signal processing, and required ECG feature detection techniques. A model-based design flow is applied, and strengths and limitations of each design step are discussed. Real-world measured data originating from the implemented sensor system are then used to set up and parametrize a novel physiological authentication protocol for BANs. The authentication protocol utilizes statistical properties of expected and detected deviations to limit the number of false positive and false negative authentication attempts. The result of the described holistic design effort is the first practical implementation of biometric authentication in BANs that reflects timing and data uncertainties in the physical and cyber parts of the system. PMID:27110785

  1. Mobile cloud-computing-based healthcare service by noncontact ECG monitoring.

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2013-01-01

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service. PMID:24316562

  2. Graphite Based Electrode for ECG Monitoring: Evaluation under Freshwater and Saltwater Conditions.

    PubMed

    Thap, Tharoeun; Yoon, Kwon-Ha; Lee, Jinseok

    2016-01-01

    We proposed new electrodes that are applicable for electrocardiogram (ECG) monitoring under freshwater- and saltwater-immersion conditions. Our proposed electrodes are made of graphite pencil lead (GPL), a general-purpose writing pencil. We have fabricated two types of electrode: a pencil lead solid type (PLS) electrode and a pencil lead powder type (PLP) electrode. In order to assess the qualities of the PLS and PLP electrodes, we compared their performance with that of a commercial Ag/AgCl electrode, under a total of seven different conditions: dry, freshwater immersion with/without movement, post-freshwater wet condition, saltwater immersion with/without movement, and post-saltwater wet condition. In both dry and post-freshwater wet conditions, all ECG-recorded PQRST waves were clearly discernible, with all types of electrodes, Ag/AgCl, PLS, and PLP. On the other hand, under the freshwater- and saltwater-immersion conditions with/without movement, as well as post-saltwater wet conditions, we found that the proposed PLS and PLP electrodes provided better ECG waveform quality, with significant statistical differences compared with the quality provided by Ag/AgCl electrodes. PMID:27092502

  3. Searching biosignal databases by content and context: Research Oriented Integration System for ECG Signals (ROISES).

    PubMed

    Kokkinaki, Alexandra; Chouvarda, Ioanna; Maglaveras, Nicos

    2012-11-01

    Technological advances in textile, biosensor and electrocardiography domain induced the wide spread use of bio-signal acquisition devices leading to the generation of massive bio-signal datasets. Among the most popular bio-signals, electrocardiogram (ECG) possesses the longest tradition in bio-signal monitoring and recording, being a strong and relatively robust signal. As research resources are fostered, research community promotes the need to extract new knowledge from bio-signals towards the adoption of new medical procedures. However, integrated access, query and management of ECGs are impeded by the diversity and heterogeneity of bio-signal storage data formats. In this scope, the proposed work introduces a new methodology for the unified access to bio-signal databases and the accompanying metadata. It allows decoupling information retrieval from actual underlying datasource structures and enables transparent content and context based searching from multiple data resources. Our approach is based on the definition of an interactive global ontology which manipulates the similarities and the differences of the underlying sources to either establish similarity mappings or enrich its terminological structure. We also introduce ROISES (Research Oriented Integration System for ECG Signals), for the definition of complex content based queries against the diverse bio-signal data sources. PMID:21397354

  4. Mobile cloud-computing-based healthcare service by noncontact ECG monitoring.

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2013-12-02

    Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service.

  5. Design of Secure ECG-Based Biometric Authentication in Body Area Sensor Networks

    PubMed Central

    Peter, Steffen; Pratap Reddy, Bhanu; Momtaz, Farshad; Givargis, Tony

    2016-01-01

    Body area sensor networks (BANs) utilize wireless communicating sensor nodes attached to a human body for convenience, safety, and health applications. Physiological characteristics of the body, such as the heart rate or Electrocardiogram (ECG) signals, are promising means to simplify the setup process and to improve security of BANs. This paper describes the design and implementation steps required to realize an ECG-based authentication protocol to identify sensor nodes attached to the same human body. Therefore, the first part of the paper addresses the design of a body-area sensor system, including the hardware setup, analogue and digital signal processing, and required ECG feature detection techniques. A model-based design flow is applied, and strengths and limitations of each design step are discussed. Real-world measured data originating from the implemented sensor system are then used to set up and parametrize a novel physiological authentication protocol for BANs. The authentication protocol utilizes statistical properties of expected and detected deviations to limit the number of false positive and false negative authentication attempts. The result of the described holistic design effort is the first practical implementation of biometric authentication in BANs that reflects timing and data uncertainties in the physical and cyber parts of the system. PMID:27110785

  6. Graphite Based Electrode for ECG Monitoring: Evaluation under Freshwater and Saltwater Conditions.

    PubMed

    Thap, Tharoeun; Yoon, Kwon-Ha; Lee, Jinseok

    2016-04-15

    We proposed new electrodes that are applicable for electrocardiogram (ECG) monitoring under freshwater- and saltwater-immersion conditions. Our proposed electrodes are made of graphite pencil lead (GPL), a general-purpose writing pencil. We have fabricated two types of electrode: a pencil lead solid type (PLS) electrode and a pencil lead powder type (PLP) electrode. In order to assess the qualities of the PLS and PLP electrodes, we compared their performance with that of a commercial Ag/AgCl electrode, under a total of seven different conditions: dry, freshwater immersion with/without movement, post-freshwater wet condition, saltwater immersion with/without movement, and post-saltwater wet condition. In both dry and post-freshwater wet conditions, all ECG-recorded PQRST waves were clearly discernible, with all types of electrodes, Ag/AgCl, PLS, and PLP. On the other hand, under the freshwater- and saltwater-immersion conditions with/without movement, as well as post-saltwater wet conditions, we found that the proposed PLS and PLP electrodes provided better ECG waveform quality, with significant statistical differences compared with the quality provided by Ag/AgCl electrodes.

  7. Correlation Changes of EEG and ECG After Fast Cable CAR Ascents.

    PubMed

    Edlinger, G; Guger, C

    2005-01-01

    In the Eastern Alps in Europe, the Dachstein. massif with a height of almost 3000 m is an ideal location for investigating the effects of changes in altitude on the human body. Within a few minutes, a cable car facilitates an ascent from 1702 m to 2700 m above sea level, where the partial pressure of oxygen is about 550 mmHg (as compared to 760 mmHg at sea level). In this study ten healthy subjects performed a reaction time task at 990 m and 2700 m in altitude. The subjects were instructed to perform a right hand index finger movement as fast as possible after a green light flashed (repeated 50 times). The corresponding electrocardiogram (ECG) and the electroencephalogram (EEG) were recorded. From the ECG heart rate and heart rate variability measures in the time and frequency domain were calculated. An event-related desynchronization/synchronization (ERD/ERS) analysis was performed with the EEG data. Finally, the EEG activity and the ECG parameters were correlated. PMID:17281509

  8. ECG response of koalas to tourists proximity: a preliminary study.

    PubMed

    Ropert-Coudert, Yan; Brooks, Lisa; Yamamoto, Maki; Kato, Akiko

    2009-01-01

    Koalas operate on a tight energy budget and, thus, may not always display behavioral avoidance reaction when placed in a stressful condition. We investigated the physiological response of captive koalas Phascolarctos cinereus in a conservation centre to the presence of tourists walking through their habitat. We compared, using animal-attached data-recorders, the electrocardiogram activity of female koalas in contact with tourists and in a human-free area. One of the koalas in the tourist zone presented elevated heart rate values and variability throughout the recording period. The remaining female in the exhibit area showed a higher field resting heart rates during the daytime than that in the isolated area. In the evening, heart rate profiles changed drastically and both the koalas in the exhibit and in the tourist-free zones displayed similar field resting heart rates, which were lower than those during the day. In parallel, the autonomic nervous systems of these two individuals evolved from sympathetic-dominant during the day to parasympathetic-dominant in the evening. Our results report ECG of free-living koalas for the first time. Although they are preliminary due to the difficulty of having sufficient samples of animals of the same sex and age, our results stress out the importance of studies investigating the physiological reaction of animals to tourists. PMID:19823679

  9. Heritability of ECG Biomarkers in the Netherlands Twin Registry Measured from Holter ECGs

    PubMed Central

    Hodkinson, Emily C.; Neijts, Melanie; Sadrieh, Arash; Imtiaz, Mohammad S.; Baumert, Mathias; Subbiah, Rajesh N.; Hayward, Christopher S.; Boomsma, Dorret; Willemsen, Gonneke; Vandenberg, Jamie I.; Hill, Adam P.; De Geus, Eco

    2016-01-01

    Introduction: The resting ECG is the most commonly used tool to assess cardiac electrophysiology. Previous studies have estimated heritability of ECG parameters based on these snapshots of the cardiac electrical activity. In this study we set out to determine whether analysis of heart rate specific data from Holter ECGs allows more complete assessment of the heritability of ECG parameters. Methods and Results: Holter ECGs were recorded from 221 twin pairs and analyzed using a multi-parameter beat binning approach. Heart rate dependent estimates of heritability for QRS duration, QT interval, Tpeak–Tend and Theight were calculated using structural equation modeling. QRS duration is largely determined by environmental factors whereas repolarization is primarily genetically determined. Heritability estimates of both QT interval and Theight were significantly higher when measured from Holter compared to resting ECGs and the heritability estimate of each was heart rate dependent. Analysis of the genetic contribution to correlation between repolarization parameters demonstrated that covariance of individual ECG parameters at different heart rates overlap but at each specific heart rate there was relatively little overlap in the genetic determinants of the different repolarization parameters. Conclusions: Here we present the first study of heritability of repolarization parameters measured from Holter ECGs. Our data demonstrate that higher heritability can be estimated from the Holter than the resting ECG and reveals rate dependence in the genetic—environmental determinants of the ECG that has not previously been tractable. Future applications include deeper dissection of the ECG of participants with inherited cardiac electrical disease. PMID:27199769

  10. Contact dermatitis caused by ECG electrode paste.

    PubMed

    Cochran, R J; Rosen, T

    1980-12-01

    A case of contact dermatitis caused by ECG electrode cream is presented and the pertinent literature is reviewed. Our patient was found to be allergic to propylene glycol. Patch-testing remains an invaluable tool in the evaluation of patients suspected of being allergic to ECG paste, creams, and gels.

  11. A novel algorithm for Bluetooth ECG.

    PubMed

    Pandya, Utpal T; Desai, Uday B

    2012-11-01

    In wireless transmission of ECG, data latency will be significant when battery power level and data transmission distance are not maintained. In applications like home monitoring or personalized care, to overcome the joint effect of previous issues of wireless transmission and other ECG measurement noises, a novel filtering strategy is required. Here, a novel algorithm, identified as peak rejection adaptive sampling modified moving average (PRASMMA) algorithm for wireless ECG is introduced. This algorithm first removes error in bit pattern of received data if occurred in wireless transmission and then removes baseline drift. Afterward, a modified moving average is implemented except in the region of each QRS complexes. The algorithm also sets its filtering parameters according to different sampling rate selected for acquisition of signals. To demonstrate the work, a prototyped Bluetooth-based ECG module is used to capture ECG with different sampling rate and in different position of patient. This module transmits ECG wirelessly to Bluetooth-enabled devices where the PRASMMA algorithm is applied on captured ECG. The performance of PRASMMA algorithm is compared with moving average and S-Golay algorithms visually as well as numerically. The results show that the PRASMMA algorithm can significantly improve the ECG reconstruction by efficiently removing the noise and its use can be extended to any parameters where peaks are importance for diagnostic purpose.

  12. Dry contact fingertip ECG-based authentication system using time, frequency domain features and support vector machine.

    PubMed

    Singh, Karan; Singhvi, Akshit; Pathangay, Vinod

    2015-08-01

    Acquiring fingertip ECG (electrocardiogram) signal using dry contact electrodes is challenging due to the presence of noise and interference by EMG (electromyogram) potentials. In this paper, we propose a method for using the fingertip ECG signal for biometric authentication. The noisy segments of the signal are segmented out using a variance-based heuristic and the clean signal is used for subsequent processing. By applying baseline correction and band pass filtering, the filtered signal is used for beat feature extraction. The features are used to train a support vector machine (SVM) classifier. Experimental results are presented to show the optimum filter parameters and feature sets for best classification performance. The performance of the proposed method with the optimum parameters was evaluated on a public domain CYBHi dataset with 126 subjects and the beat level EER of 3.4% was obtained.

  13. Dry contact fingertip ECG-based authentication system using time, frequency domain features and support vector machine.

    PubMed

    Singh, Karan; Singhvi, Akshit; Pathangay, Vinod

    2015-08-01

    Acquiring fingertip ECG (electrocardiogram) signal using dry contact electrodes is challenging due to the presence of noise and interference by EMG (electromyogram) potentials. In this paper, we propose a method for using the fingertip ECG signal for biometric authentication. The noisy segments of the signal are segmented out using a variance-based heuristic and the clean signal is used for subsequent processing. By applying baseline correction and band pass filtering, the filtered signal is used for beat feature extraction. The features are used to train a support vector machine (SVM) classifier. Experimental results are presented to show the optimum filter parameters and feature sets for best classification performance. The performance of the proposed method with the optimum parameters was evaluated on a public domain CYBHi dataset with 126 subjects and the beat level EER of 3.4% was obtained. PMID:26736315

  14. A wireless sensor network compatible wearable u-healthcare monitoring system using integrated ECG, accelerometer and SpO2.

    PubMed

    Chung, Wan-Young; Lee, Young-Dong; Jung, Sang-Joong

    2008-01-01

    This paper presents the design and development of a wearable ubiquitous healthcare monitoring system using integrated electrocardiogram (ECG), accelerometer and oxygen saturation (SpO(2)) sensors. In this design, non-intrusive healthcare system was designed based on wireless sensor network (WSN) for wide area coverage with minimum battery power to support RF transmission. We have developed various devices such as wearable ubiquitous sensor network (USN) node, wearable chest sensor belt and wrist pulse oximeter for this system. Low power ECG, accelerometer and SpO(2) sensors board was integrated to the wearable USN node for user's health monitoring. The wearable ubiquitous healthcare monitoring system allows physiological data to be transmitted in wireless sensor network using IEEE 802.15.4 from on-body wearable sensor devices to a base-station which is connected to a server PC. Physiological data can be displayed and stored in the server PC continuously.

  15. PLI cancellation in ECG signal based on adaptive filter by using Wiener-Hopf equation for providing initial condition.

    PubMed

    Manosueb, Anchalee; Koseeyaporn, Jeerasuda; Wardkein, Paramote

    2014-01-01

    This paper presents a technique for finding the optimal initial weight for adaptive filter by using difference equation. The obtained analytical response of the system identifies the appropriate weights for the system and shows that the MSE depends on the initial weight. The proposed technique is applied to eliminate the known frequency power line interference (PLI) signal in the electrocardiogram (ECG) signal. The PLI signal is considered as a combination of cosine and sine signals. The adaptive filter, therefore, attempts to adjust the amplitude of cosine and sine signals to synthesize a reference signal very similar to the contaminated PLI signal. To compare the potential of the proposed technique to other techniques, the system is simulated by using the Matlab program and the TMS320C6713 digital board. The simulation results demonstrate that the proposed technique enables the system to eliminate the PLI signal with the fastest time and gains the superior results of the recovered ECG signal.

  16. Algorithms Based on CWT and Classifiers to Control Cardiac Alterations and Stress Using an ECG and a SCR

    PubMed Central

    Villarejo, María Viqueira; Zapirain, Begoña García; Zorrilla, Amaia Méndez

    2013-01-01

    This paper presents the results of using a commercial pulsimeter as an electrocardiogram (ECG) for wireless detection of cardiac alterations and stress levels for home control. For these purposes, signal processing techniques (Continuous Wavelet Transform (CWT) and J48) have been used, respectively. The designed algorithm analyses the ECG signal and is able to detect the heart rate (99.42%), arrhythmia (93.48%) and extrasystoles (99.29%). The detection of stress level is complemented with Skin Conductance Response (SCR), whose success is 94.02%. The heart rate variability does not show added value to the stress detection in this case. With this pulsimeter, it is possible to prevent and detect anomalies for a non-intrusive way associated to a telemedicine system. It is also possible to use it during physical activity due to the fact the CWT minimizes the motion artifacts. PMID:23666135

  17. Algorithms based on CWT and classifiers to control cardiac alterations and stress using an ECG and a SCR.

    PubMed

    Villarejo, María Viqueira; Zapirain, Begoña García; Zorrilla, Amaia Méndez

    2013-05-10

    This paper presents the results of using a commercial pulsimeter as an electrocardiogram (ECG) for wireless detection of cardiac alterations and stress levels for home control. For these purposes, signal processing techniques (Continuous Wavelet Transform (CWT) and J48) have been used, respectively. The designed algorithm analyses the ECG signal and is able to detect the heart rate (99.42%), arrhythmia (93.48%) and extrasystoles (99.29%). The detection of stress level is complemented with Skin Conductance Response (SCR), whose success is 94.02%. The heart rate variability does not show added value to the stress detection in this case. With this pulsimeter, it is possible to prevent and detect anomalies for a non-intrusive way associated to a telemedicine system. It is also possible to use it during physical activity due to the fact the CWT minimizes the motion artifacts.

  18. Body surface ECG signal shape dispersion.

    PubMed

    Khaddoumi, Balkine; Rix, Hervé; Meste, Olivier; Fereniec, Małgorzata; Maniewski, Roman

    2006-12-01

    The spatial distribution of the shape of the electrocardiography (ECG) waves obtained by body surface potential mapping (BSPM) is studied, using a 64-channel high-resolution ECG system. The index associated to each lead is the shape difference between its ECG wave and a reference computed taking into account all the leads on the same column. The reference is either a selected real wave or a synthetic signal computed by integral shape averaging (ISA). Better results are obtained with the ISA signal using the distribution function method (DFM) for computing the shape difference. The spatial dispersion of ECG waves is showed to allow the separation of patients after myocardial infarction (MI) from healthy subjects. In addition, the reference signal position for each column is computed. The path linking these positions appears as an invariant, i.e., it is independent of the subject and the ECG wave.

  19. A 24-HOUR AMBULATORY ECG MONITORING IN ASSESSMENT OF QT INTERVAL DURATION AND DISPERSION IN ROWERS WITH PHYSIOLOGICAL MYOCARDIAL HYPERTROPHY

    PubMed Central

    Kim, Z.F.; Bilalova, R.R.; Tsibulkin, N.A.; Almetova, R.R.; Mudarisova, R.R.; Ahmetov, I.I.

    2013-01-01

    Myocardial hypertrophy (MH) due to cardiac pathology is characterized by an increase in QT interval duration and dispersion, while the findings for exercise-induced myocardial hypertrophy are contradictory. The majority of published research findings have not explored this relationship, but there have only been a few conducted studies using 24-hour ECG monitoring. The aim of the study was to determine the QT interval duration and dispersion in short-term and 24-hour ECG in endurance athletes with myocardial hypertrophy and without it. Methods: A total of 26 well-trained rowers underwent a resting 12-lead ECG, 24-hour ECG monitoring and echocardiography. Results: Athletes with MH (n = 7) at rest did not show any increase in QTc interval duration and dispersion, or mean and maximal QTc duration in Holter monitoring compared to athletes without MH (n = 19). Left ventricular mass was not significantly correlated with any QTc characteristics. Furthermore, athletes with MH had significantly longer mean QT (P = 0.01) and maximal QT (P = 0.018) intervals in Holter monitoring and higher 24-hour heart rate variability indexes due to stronger vagal effects. Conclusions: The present study demonstrated that athlete's heart syndrome with myocardial hypertrophy as a benign phenomenon does not lead to an increase in QT interval duration, or increases in maximal and mean duration in a 24-hour ECG. An increase in QT interval duration in athletes may have an autonomic nature. PMID:24744494

  20. Effects of cuff inflation and deflation on pulse transit time measured from ECG and multi-wavelength PPG.

    PubMed

    Liu, Jing; Li, Yao; Ding, Xiao-Rong; Dai, Wen-Xuan; Zhang, Yuan-Ting

    2015-01-01

    Pulse transit time (PTT), which refers to the time it takes a pulse wave to travel between two arterial sites is a promising index for cuff-less blood pressure (BP) estimation, as well as non-invasive assessment of arterial functions. However, it has not been investigated whether PTTs measured from ECG and different wavelength PPG are equally affected by the arterial status. Furthermore, comparison between the changes of different PTTs can provide enlightenment on the hardware implementation of the PTT-based BP estimation method. This work mainly studied the changes of PTTs calculated from electrocardiogram (ECG) and multi-wavelength photoplethysmogram (PPG) after exerting cuff pressure on the upper arm. A four-channel PPG acquisition system was developed to collect the multi-wavelength PPG signals of red, yellow, green and blue light at the fingertip simultaneously. Ten subjects participated in the experiment and their PTTs measured from different PPG and ECG signals before and after exerting cuff pressure were compared. This study found that within one minute after the four-minute cuff inflation and deflation process, the PTT measured from ECG and yellow PPG experienced a significant increase (p<;0.05) while the PTT from ECG and blue PPG had no statistical difference (p>0.9) compared with that before exerting cuff pressure. This indicates that PTTs calculated from different wavelength PPG have different recoverability from smooth muscle relaxation. Another interesting finding is that the PTT calculated from ECG and yellow PPG had a strong correlation (|r|>0.7) with the time difference between yellow PPG and other PPG signals, which implies the potential of the time difference between yellow PPG and other PPGs as a complementary to PTT-based model for blood pressure estimation. PMID:26737652

  1. Improvement of surface ECG recording in adult zebrafish reveals that the value of this model exceeds our expectation.

    PubMed

    Liu, Chi Chi; Li, Li; Lam, Yun Wah; Siu, Chung Wah; Cheng, Shuk Han

    2016-01-01

    The adult zebrafish has been used to model the electrocardiogram (ECG) for human cardiovascular studies. Nonetheless huge variations are observed among studies probably because of the lack of a reliable and reproducible recording method. In our study, an adult zebrafish surface ECG recording technique was improved using a multi-electrode method and by pre-opening the pericardial sac. A convenient ECG data analysis method without wavelet transform was also established. Intraperitoneal injection of KCl in zebrafish induced an arrhythmia similar to that of humans, and the arrhythmia was partially rescued by calcium gluconate. Amputation and cryoinjury of the zebrafish heart induced ST segment depression and affected QRS duration after injury. Only cryoinjury decelerated the heart rate. Different changes were also observed in the QT interval during heart regeneration in these two injury models. We also characterized the electrocardiophysiology of breakdance zebrafish mutant with a prolonged QT interval, that has not been well described in previous studies. Our study provided a reliable and reproducible means to record zebrafish ECG and analyse data. The detailed characterization of the cardiac electrophysiology of zebrafish and its mutant revealed that the potential of the zebrafish in modeling the human cardiovascular system exceeds expectations. PMID:27125643

  2. Architecture design of the multi-functional wavelet-based ECG microprocessor for realtime detection of abnormal cardiac events.

    PubMed

    Cheng, Li-Fang; Chen, Tung-Chien; Chen, Liang-Gee

    2012-01-01

    Most of the abnormal cardiac events such as myocardial ischemia, acute myocardial infarction (AMI) and fatal arrhythmia can be diagnosed through continuous electrocardiogram (ECG) analysis. According to recent clinical research, early detection and alarming of such cardiac events can reduce the time delay to the hospital, and the clinical outcomes of these individuals can be greatly improved. Therefore, it would be helpful if there is a long-term ECG monitoring system with the ability to identify abnormal cardiac events and provide realtime warning for the users. The combination of the wireless body area sensor network (BASN) and the on-sensor ECG processor is a possible solution for this application. In this paper, we aim to design and implement a digital signal processor that is suitable for continuous ECG monitoring and alarming based on the continuous wavelet transform (CWT) through the proposed architectures--using both programmable RISC processor and application specific integrated circuits (ASIC) for performance optimization. According to the implementation results, the power consumption of the proposed processor integrated with an ASIC for CWT computation is only 79.4 mW. Compared with the single-RISC processor, about 91.6% of the power reduction is achieved.

  3. A particle filter framework for the estimation of heart rate from ECG signals corrupted by motion artifacts.

    PubMed

    Nathan, Viswam; Akkaya, Ilge; Jafari, Roozbeh

    2015-01-01

    In this work, we describe a methodology to probabilistically estimate the R-peak locations of an electrocardiogram (ECG) signal using a particle filter. This is useful for heart rate estimation, which is an important metric for medical diagnostics. Some scenarios require constant in-home monitoring using a wearable device. This poses a particularly challenging environment for heart rate detection, due to the susceptibility of ECG signals to motion artifacts. In this work, we show how the particle filter can effectively track the true R-peak locations amidst the motion artifacts, given appropriate heart rate and R-peak observation models. A particle filter based framework has several advantages due to its freedom from strict assumptions on signal and noise models, as well as its ability to simultaneously track multiple possible heart rate hypotheses. Moreover, the proposed framework is not exclusive to ECG signals and could easily be leveraged for tracking other physiological parameters. We describe the implementation of the particle filter and validate our approach on real ECG data affected by motion artifacts from the MIT-BIH noise stress test database. The average heart rate estimation error is about 5 beats per minute for signal streams contaminated with noisy segments with SNR as low as -6 dB. PMID:26737796

  4. Empirical mode decomposition of multiple ECG leads for catheter ablation long-term outcome prediction in persistent atrial fibrillation.

    PubMed

    Hidalgo-Munoz, Antonio R; Tome, Ana M; Latcu, Decebal G; Zarzoso, Vicente

    2015-01-01

    Predictive models arouse increasing interest in clinical practice, not only to improve successful intervention rates but also to extract information of diverse physiological disorders. This is the case of persistent atrial fibrillation (AF), the most common cardiac arrhythmia in adults. Currently, catheter ablation (CA) is one of the preferred therapies to face this disease. However, selecting the best responders to CA by standard noninvasive techniques such as the electrocardiogram (ECG) remains a challenge. This work presents different predictive models for determining long-term CA outcome based on the dominant frequency (DF) of atrial activity measured in the ECG. The ensemble empirical mode decomposition (EEMD) is employed to obtain the intrinsic mode functions (IMFs) composing the ECG signal in each lead. The IMF DFs computed in multiple leads are then combined into a logistic regression (LR) model. The IMF DF features are discriminant enough to reach 79% accuracy for long-term CA outcome prediction, outperforming other methods based on DF computation. Our study shows EEMD as a valuable alternative to extract clinically relevant spectral information from AF ECGs and confirms the advantage of LR to build multivariate predictive models as compared with univariate analysis.

  5. Improvement of surface ECG recording in adult zebrafish reveals that the value of this model exceeds our expectation

    PubMed Central

    Liu, Chi Chi; Li, Li; Lam, Yun Wah; Siu, Chung Wah; Cheng, Shuk Han

    2016-01-01

    The adult zebrafish has been used to model the electrocardiogram (ECG) for human cardiovascular studies. Nonetheless huge variations are observed among studies probably because of the lack of a reliable and reproducible recording method. In our study, an adult zebrafish surface ECG recording technique was improved using a multi-electrode method and by pre-opening the pericardial sac. A convenient ECG data analysis method without wavelet transform was also established. Intraperitoneal injection of KCl in zebrafish induced an arrhythmia similar to that of humans, and the arrhythmia was partially rescued by calcium gluconate. Amputation and cryoinjury of the zebrafish heart induced ST segment depression and affected QRS duration after injury. Only cryoinjury decelerated the heart rate. Different changes were also observed in the QT interval during heart regeneration in these two injury models. We also characterized the electrocardiophysiology of breakdance zebrafish mutant with a prolonged QT interval, that has not been well described in previous studies. Our study provided a reliable and reproducible means to record zebrafish ECG and analyse data. The detailed characterization of the cardiac electrophysiology of zebrafish and its mutant revealed that the potential of the zebrafish in modeling the human cardiovascular system exceeds expectations. PMID:27125643

  6. New gender-specific partition values for ECG criteria of left ventricular hypertrophy: recalibration against cardiac MRI.

    PubMed

    Alfakih, Khaled; Walters, Kevin; Jones, Tim; Ridgway, John; Hall, Alistair S; Sivananthan, Mohan

    2004-08-01

    ECG criteria for left ventricular hypertrophy (LVH) were mostly validated using left ventricular mass (LVM) as measured by M-mode echocardiography. LVM as measured by cardiac MRI has been demonstrated to be much more accurate and reproducible. We reevaluated the sensitivity and specificity of 4 ECG criteria of LVH against LVM as measured by cardiac MRI. Patients with systemic hypertension (n=288) and 60 normal volunteers had their LVM measured using a 1.5-Tesla MRI system. A 12-lead ECG was recorded, and 4 ECG criteria were evaluated: Sokolow-Lyon voltage, Cornell voltage, Cornell product, and Sokolow-Lyon product. Based on a cardiac MRI normal range, 39.9% of the hypertensive males and 36.7% of the hypertensive females had elevated LVM index. At a specificity of 95%, the Sokolow-Lyon product criterion had the highest sensitivity in females (26.2%), the Cornell criterion had the highest sensitivity in males (26.2%), and the Cornell product criteria had a relatively high sensitivity in both males and females (25.0% and 23.8%). Receiver operating characteristic curves showed the Cornell and Cornell product criteria to be superior for males whereas the Sokolow-Lyon product criterion was superior for females. Comparing the mean LVM index values of the subjects who were ECG LVH positive to the normal volunteers indicated that the ECG LVH criteria detect individuals with an LVM index substantially above the normal range. We have redefined the partition values for 4 different ECG LVH criteria, according to gender, and found that they detect subjects with markedly elevated LVM index.

  7. To decide medical therapy according to ECG criteria in patients with supraventricular tachycardia in emergency department: adenosine or diltiazem

    PubMed Central

    Dogan, Halil; Ozucelik, Dogac Niyazi; Aciksari, Kurtulus; Caglar, Ilker Murat; Okutan, Nursel; Yazicioglu, Mustafa; Avyaci, Baris Murat; Simsek, Cem; Ozasir, Derya; Giray, Tufan Akin; Ayan, Cem; Celikmen, Feridun; Okuturlar, Yıldız; Sarikaya, Sezgin

    2015-01-01

    The aim of this study is to investigate the effect of ECG criteria which are used for the distinction between AVNRT and AVRT for the choice of treatment in patients with Supraventricular Tachycardia (SVT). The 77 patients with narrow QRS complex SVT which was treated with Adenosine or Diltiazem in the Emergency Department were evaluated retrospectively. All 12-lead ECG during tachycardia were blindly reviewed according to ECG criteria (Pseudo-r` in V1, Pseudo-S-wave in the inferior leads, Visible P-wave, aVL notch) by a cardiologist and an emergency physician. In this study, while 59.6% of the patients returned to normal sinus rhythm (NSR) after the first dose 6 mg, 64.91% of them after the first dose 12 mg and 71.92% of them after the second dose of 12 mg adenosine, 95% of the patients returned to NSR after the 0.25 mg/kg diltiazem. The most visible ECG findings were visible P waves and the least visible ECG findings were Pseudo-S waves in the inferior leads. It was statistically significant between converted by adenosine to NSR and converted by diltiazem to NSR to the presence of visible P-wave and the aVL lead notch in their ECG findings. Conclusion: The rate of return to NSR through diltiazem was found higher than that of adenosine in narrow complex SVT patients. Also, diltiazem may be the first medication to be preferred in the presence of retrograt P wave and aVL notch in the ECG of the patients with narrow QRS complex stable SVT. PMID:26309644

  8. Improving ECG Services at a Children's Hospital: Implementation of a Digital ECG System

    PubMed Central

    Osei, Frank A.; Gates, Gregory J.; Choi, Steven J.; Hsu, Daphne T.; Pass, Robert H.; Ceresnak, Scott R.

    2015-01-01

    Background. The use of digital ECG software and services is becoming common. We hypothesized that the introduction of a completely digital ECG system would increase the volume of ECGs interpreted at our children's hospital. Methods. As part of a hospital wide quality improvement initiative, a digital ECG service (MUSE, GE) was implemented at the Children's Hospital at Montefiore in June 2012. The total volume of ECGs performed in the first 6 months of the digital ECG era was compared to 18 months of the predigital era. Predigital and postdigital data were compared via t-tests. Results. The mean ECGs interpreted per month were 53 ± 16 in the predigital era and 216 ± 37 in the postdigital era (p < 0.001), a fourfold increase in ECG volume after introduction of the digital system. There was no significant change in inpatient or outpatient service volume during that time. The mean billing time decreased from 21 ± 27 days in the postdigital era to 12 ± 5 days in the postdigital era (p < 0.001). Conclusion. Implementation of a digital ECG system increased the volume of ECGs officially interpreted and reported. PMID:26451150

  9. ‘Action potential-like’ ST elevation following pseudo-Wellens' electrocardiogram

    PubMed Central

    Oksuz, Fatih; Sensoy, Baris; Sen, Fatih; Celik, Ethem; Ozeke, Ozcan; Maden, Orhan

    2015-01-01

    Coronary artery vasospasm is an important cause of chest pain syndromes that can lead to myocardial infarction, ventricular arrhythmias, and sudden death. In 1959, Prinzmetal et al described a syndrome of nonexertional chest pain with ST-segment elevation on electrocardiography. Persistent angina is challenging, and repeated coronary angioplasty may be required in this syndrome. Calcium antagonists are extremely effective in treating and preventing coronary spasm, and may provide long-lasting relief for the patient. Whereas the Wellens' syndrome is characterized by symmetrically inverted T-waves with preserved R waves in the precordial leads suggestive of impending myocardial infarction due to a critical proximal left anterior descending stenosis, the pseudo-Wellens' syndrome caused by coronary artery spasm has also rarely been reported in literature. We present a pseudo-Wellens syndrome as a cause of vasospastic angina, and a diffuse ST segment elavation on electrocardiogram resembling the Greek letter lambda, called also 'action potential-like' ECG in a patient with vasospastic-type Printzmetal angina. PMID:26432739

  10. ECG findings after myocardial infarction in children after Kawasaki disease

    SciTech Connect

    Nakanishi, T.; Takao, A.; Kondoh, C.; Nakazawa, M.; Hiroe, M.; Matsumoto, Y.

    1988-10-01

    Standard 12-lead ECGs were evaluated in 17 children with myocardial infarction and 78 children without myocardial infarction after Kawasaki disease; sensitivity and specificity of the ECG infarction criteria were determined. The presence or absence of myocardial infarction was determined from either clinical examination results (coronary angiography, ventriculography, and thallium-201 myocardial imaging) or autopsy findings. Of seven patients with inferior infarction, abnormally deep Q waves in lead II, III, or aVF were observed in six, but the duration was greater than 0.04 second in only one (14%). The sensitivity and specificity of inferior infarction criteria based on Q wave amplitude were 86% and 97%, respectively. Of eight patients with anterior infarction, seven (88%) had abnormally deep and wide (greater than or equal to 0.04 second) Q waves in anterior chest leads. The sensitivity and specificity of the infarction criteria based on the amplitude and duration of the Q wave were 75% and 99%, respectively. Of seven patients with lateral infarction, Q waves were observed in lead I, aVL, or both in four patients, and in all of these patients Q waves were wider than 0.04 second. In two patients with both inferior and anterior infarction, Q waves were observed only in leads II, III, and aVF; in only one patient were the Q waves wider than 0.04 second. Thus deep Q waves in lead II, III, or aVF that are not wider than 0.04 second may indicate inferior infarction in children. Q waves in lead I, aVL, and chest leads associated with anterolateral infarction are in most instances deep and wide.

  11. Recording of ECG signals on a portable MiniDisc recorder for time and frequency domain heart rate variability analysis.

    PubMed

    Norman, S E; Eager, R A; Waran, N K; Jeffery, L; Schroter, R C; Marlin, D J

    2005-01-17

    Analysis of heart rate variability (HRV) is a non-invasive technique useful for investigating autonomic function in both humans and animals. It has been used for research into both behaviour and physiology. Commercial systems for human HRV analysis are expensive and may not have sufficient flexibility for appropriate analysis in animals. Some heart rate monitors have the facility to provide inter-beat interval (IBI), but verification following collection is not possible as only IBIs are recorded, and not the raw electrocardiogram (ECG) signal. Computer-based data acquisition and analysis systems such as Po-Ne-Mah and Biopac offer greater flexibility and control but have limited portability. Many laboratories and veterinary surgeons have access to ECG machines but do not have equipment to record ECG signals for further analysis. The aim of the present study was to determine whether suitable HRV data could be obtained from ECG signals recorded onto a MiniDisc (MD) and subsequently digitised and analysed using a commercial data acquisition and analysis package. ECG signals were obtained from six Thoroughbred horses by telemetry. A split BNC connecter was used to allow simultaneous digitisation of analogue output from the ECG receiver unit by a computerised data acquisition system (Po-Ne-Mah) and MiniDisc player (MZ-N710, Sony). Following recording, data were played back from the MiniDisc into the same input channel of the data acquisition system as previously used to record the direct ECG. All data were digitised at a sampling rate of 500 Hz. IBI data were analysed in both time and frequency domains and comparisons between direct recorded and MiniDisc data were made using Bland-Altman analysis. Despite some changes in ECG morphology due to loss of low frequency content (primarily below 5 Hz) following MiniDisc recording, there was minimal difference in IBI or time or frequency domain analysis between the two recording methods. The MiniDisc offers a cost

  12. Biomedical Implementation of Liquid Metal Ink as Drawable ECG Electrode and Skin Circuit

    PubMed Central

    Yu, Yang; Zhang, Jie; Liu, Jing

    2013-01-01

    Background Conventional ways of making bio-electrodes are generally complicated, expensive and unconformable. Here we describe for the first time the method of applying Ga-based liquid metal ink as drawable electrocardiogram (ECG) electrodes. Such material owns unique merits in both liquid phase conformability and high electrical conductivity, which provides flexible ways for making electrical circuits on skin surface and a prospective substitution of conventional rigid printed circuit boards (PCBs). Methods Fundamental measurements of impedance and polarization voltage of the liquid metal ink were carried out to evaluate its basic electrical properties. Conceptual experiments were performed to draw the alloy as bio-electrodes to acquire ECG signals from both rabbit and human via a wireless module developed on the mobile phone. Further, a typical electrical circuit was drawn in the palm with the ink to demonstrate its potential of implementing more sophisticated skin circuits. Results With an oxide concentration of 0.34%, the resistivity of the liquid metal ink was measured as 44.1 µΩ·cm with quite low reactance in the form of straight line. Its peak polarization voltage with the physiological saline was detected as −0.73 V. The quality of ECG wave detected from the liquid metal electrodes was found as good as that of conventional electrodes, from both rabbit and human experiments. In addition, the circuit drawn with the liquid metal ink in the palm also runs efficiently. When the loop was switched on, all the light emitting diodes (LEDs) were lit and emitted colorful lights. Conclusions The liquid metal ink promises unique printable electrical properties as both bio-electrodes and electrical wires. The implemented ECG measurement on biological surface and the successfully run skin circuit demonstrated the conformability and attachment of the liquid metal. The present method is expected to innovate future physiological measurement and biological circuit

  13. High-frequency Electrocardiogram Analysis in the Ability to Predict Reversible Perfusion Defects during Adenosine Myocardial Perfusion Imaging

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.; Carlsson, Marcus; Pettersson, Jonas; Nilsson, Klas; Pahlm, Olle

    2007-01-01

    Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on myocardial perfusion imaging (MPI) scans during adenosine. The purpose of the present study was to try to reproduce those findings. Methods: 12-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. HF-QRS were analyzed regarding morphology and changes in root mean square (RMS) voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC=0.736) in a combination of morphology and RMS changes. None of the measurements, however, were statistically better than tossing a coin (AUC=0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans.

  14. Short-term effects of oral dronedarone administration on cardiac function, blood pressure and electrocardiogram in conscious telemetry dogs

    PubMed Central

    SAENGKLUB, Nakkawee; YOUNGBLOOD, Brad; DEL RIO, Carlos; SAWANGKOON, Suwanakiet; HAMLIN, Robert L.; KIJTAWORNRAT, Anusak

    2016-01-01

    Dronedarone is a multichannel blocking antiarrhythmic drug that has been used for management of atrial fibrillation in humans, but the data in veterinary medicine are inadequate. The objective of this study was to determine the short-term effects of oral dronedarone on cardiac inotropy and lusitropy, blood pressure and electrocardiogram (ECG) in healthy dogs. A total of 6 beagle dogs were instrumented with telemetry units and sono-micrometry crystals to obtain left ventricular pressure-volume relationship, mean blood pressure (MBP) and ECG. Dogs were given orally dronedarone (20 mg/kg, twice per day) for 7 days. All parameters were obtained hourly at 4–8 hr after the first dose and at 12-, 96- (day 4) and 168-hr (day 7) after dosing. The results showed that dronedarone had no effect on inotropy and lusitropy, while it significantly lengthened PQ interval (P<0.001) and lowered MBP (P<0.05). Dronedarone also tended to reduce cardiac output (P=0.237) and heart rate (P=0.057). These results suggested that short-term effects of oral dronedarone administration at a dose of 20 mg/kg, twice per day, produced negative dromotropy with minimal effect on cardiac function in conscious dogs. PMID:26922916

  15. Compressive sensing of electrocardiogram signals by promoting sparsity on the second-order difference and by using dictionary learning.

    PubMed

    Pant, Jeevan K; Krishnan, Sridhar

    2014-04-01

    A new algorithm for the reconstruction of electrocardiogram (ECG) signals and a dictionary learning algorithm for the enhancement of its reconstruction performance for a class of signals are proposed. The signal reconstruction algorithm is based on minimizing the lp pseudo-norm of the second-order difference, called as the lp(2d) pseudo-norm, of the signal. The optimization involved is carried out using a sequential conjugate-gradient algorithm. The dictionary learning algorithm uses an iterative procedure wherein a signal reconstruction and a dictionary update steps are repeated until a convergence criterion is satisfied. The signal reconstruction step is implemented by using the proposed signal reconstruction algorithm and the dictionary update step is implemented by using the linear least-squares method. Extensive simulation results demonstrate that the proposed algorithm yields improved reconstruction performance for temporally correlated ECG signals relative to the state-of-the-art lp(1d)-regularized least-squares and Bayesian learning based algorithms. Also for a known class of signals, the reconstruction performance of the proposed algorithm can be improved by applying it in conjunction with a dictionary obtained using the proposed dictionary learning algorithm.

  16. [A USB-Based Digital ECG Sensor].

    PubMed

    Shi Bol; Kong, Xiangyong; Ma, Xiaozhi; Zhang, Genxuan

    2016-01-01

    Based on the ECG-specific BMD 101 integrated circun chip, this study designed a digital ECG sensor. In practical application, users just need to connect the ECG sensor 'o upper computer (such as PC or mobile phone) through USB interface, to realize the functions including display, alarm, saving, transfer etc. After tests, They demonstrate that the sensor can be applied to the detection of arrhythmia, such as bigeminy coupled rhythm, proiosystole etc. Besides, the sensor has various advantages in monitoring an managing the heart health of people out of hospital, including low cost, small volume, usableness, simplicity of operation etc. PMID:27197497

  17. Month-to-Month and Year-to-Year Reproducibility of High Frequency QRS ECG signals

    NASA Technical Reports Server (NTRS)

    Batdorf, Niles; Feiveson, Alan H.; Schlegel, Todd T.

    2006-01-01

    High frequency (HF) electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. We therefore prospectively investigated the reproducibility of the root mean squared (RMS) voltage, kurtosis, and the presence versus absence of reduced amplitude zones (RAzs) in signal averaged 12-lead HF QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of RMS voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of RMS voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. RAzs were also reproducible at a rate of up to 87% and 8 1 %, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead HF QRS electrocardiograms are sufficiently reproducible for clinical use.

  18. Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals

    NASA Technical Reports Server (NTRS)

    Batdorf, Niles J.; Feiveson, Alan H.; Schlegel, Todd T.

    2004-01-01

    High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use.

  19. New Features of Electrocardiogram in a Case Report of Arrhythmogenic Right Ventricular Cardiomyopathy: A Care-Compliant Article.

    PubMed

    Pei, Haifeng; Yu, Qiujun; Su, Xiaohua; Wang, Zhen; Zhao, Heng; Yang, Dachun; Yang, Yongjian; Li, De

    2016-04-01

    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a crucial health problem. With sudden death often being the first presentation, early diagnosis for ARVC is essential. Up to date, electrocardiogram (ECG) is a widely used diagnostic method without invasive harms. To diagnose and treat ARVC as well as possible, we should clearly elucidate its pathophysiological alterations. A 66-year-old farmer presented to the Emergency Department with continuous palpitation, chest tightness, profuse sweating, and nausea with no obvious predisposing causes. An ECG indicated ventricular tachycardia (VT). The patient experienced a sudden drop in blood pressure and acute confusion. After an immediate electrical conversion, his consciousness was gradually restored, and symptoms relieved. The patient was then transferred to the Department of Cardiology to receive ECG, echocardiography, coronary angiogram, biochemical assays, endocardiac tracing, and radiofrequency ablation. In the end, he was diagnosed with ARVC, evidenced by bilateral ventricle dilation and epsilon waves in leads V1-V3. Appropriate therapies were provided for this patient including pharmacological intervention and radiofrequency ablation. Although the diagnosis of ARVC is not difficult, this patient's ECG manifested several interesting features and should be further investigated: T wave inversions were found extensively in the anterior and inferior leads, revealing the involvement of bilateral ventricles; VTs with different morphologies and cycle lengths were found, and some VTs manifested the feature of irregularly irregular rhythm, reminding us to carefully differentiate some special VTs from atrial fibrillation (AF); and epsilon waves gradually appeared in leads V1-V3 and avR since the onset of ARVC. Most importantly, the epsilon waves behind QRS complex appeared in both sinus rhythm and ventricular premature beats/VT originating from cardiac apex, whereas the epsilon waves prior to QRS complex occurred in

  20. Electrocardiogram-Gated 320-Slice Multidetector Computed Tomography for the Measurement of Pulmonary Arterial Distensibility in Chronic Thromboembolic Pulmonary Hypertension

    PubMed Central

    Kasai, Hajime; Sugiura, Toshihiko; Tanabe, Nobuhiro; Sakurai, Yoriko; Yahaba, Misuzu; Matsuura, Yukiko; Shigeta, Ayako; Kawata, Naoko; Sakao, Seiichiro; Kasahara, Yasunori; Tatsumi, Koichiro

    2014-01-01

    Background We aimed to study whether pulmonary arterial distensibility (PAD) correlates with hemodynamic parameters in chronic thromboembolic pulmonary hypertension (CTEPH) using electrocardiogram (ECG)-gated 320-slice multidetector computed tomography (MDCT). Methods and Findings ECG-gated 320-slice MDCT and right heart catheterization (RHC) was performed in 53 subjects (60.6±11.4 years old; 37 females) with CTEPH. We retrospectively measured the minimum and maximum values of the cross sectional area (CSA) of the main pulmonary artery (mainPA), right pulmonary artery (rtPA), and left pulmonary artery (ltPA) during one heartbeat. PAD was calculated using the following formula: PAD = [(CSAmaximum−CSAminimum)/CSAmaximum]×100(%). The correlation between hemodynamic parameters and PAD was assessed. Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) were 40.8±8.7 mmHg and 8.3±3.0 wood units, respectively. PAD values were as follows: mainPA (14.0±5.0%), rtPA (12.8±5.6%), and ltPA (9.7±4.6%). Good correlations existed between mainPAD, with mPAP (r = −0.594, p<0.001) and PVR (r = −0.659, p<0.001). The correlation coefficients between rtPAD and ltPAD with pulmonary hemodynamics were all lower or equal than for mainPAD. Conclusions PAD measured using ECG-gated 320-slice MDCT correlates with pulmonary hemodynamics in subjects with CTEPH. The mainPA is suitable for PAD measurement. PMID:25365168

  1. ECG identification of left ventricular hypertrophy. Relationship of test performance to body habitus.

    PubMed

    Okin, P M; Roman, M J; Devereux, R B; Kligfield, P

    1996-01-01

    Obesity is associated with the presence of left ventricular hypertrophy (LVH) and, conversely, with decreased sensitivity of the electrocardiogram (ECG) for LVH due to attenuating effects on QRS amplitudes. Although the Framingham-adjusted Cornell voltage, incorporating age, sex, and body mass index (BMI), was developed to correct for the effects of obesity on the accuracy of the ECG, the impact of body habitus on ECG detection of LVH for newer, more accurate ECG criteria based on the time-voltage area under the QRS complex has not been determined. The authors examined the test accuracy of the Sokolow-Lyon voltage, Cornell voltage, Cornell product (product of QRS duration and Cornell voltage), Framingham-adjusted Cornell voltage, and time-voltage area of the horizontal plane vector QRS for the detection of echocardiographic LVH in relation to body habitus in 250 patients. Normal-weight or overweight status was based on sex-specific population-based BMI partitions. Using partitions with a matched specificity of 98% in the overall population without LVH, the sensitivity of standard ECG criteria varied according to body habitus. Sensitivity of the Framingham-adjusted Cornell voltage was less in normal-weight than in overweight patients (49 vs 59%, P = .0004); there were also trends toward lower sensitivity in normal-weight patients for the Cornell voltage (40 vs 65%, P = .10) and the Cornell product (43 vs 65%, P = NS), but sensitivity of the Sokolow-Lyon voltage was lower in obese than in nonobese patients (18 vs 50%, P = .025). In contrast, the horizontal plane vector area had similar sensitivity in obese and normal-weight patients (76 vs 74%, P = NS). Specificity varied with body habitus only for the Framingham-adjusted Cornell voltage: 100% in normal-weight vs 95% in overweight patients (P < .05). Thus, accuracy of the Framingham-adjusted Cornell voltage and Sokolow-Lyon voltage varies significantly with body habitus. In contrast, accuracy of the Cornell voltage

  2. A Novel Mobile ECG Telemonitoring System.

    PubMed

    Wu, Baoming; Zhuo, Yu; Zhu, Xinjian; Yan, Qingguang; Zhu, Lingyun; Li, Gang

    2005-01-01

    This paper introduces a novel mobile ECG telemonitoring system. By means of CDMA1x (GPSOne) mobile telecommunication network, the system can perform "full time and space" monitoring of human ECG signal, and once the signal of the monitored subject departed from its normal ranges, the hospital ECG monitoring center can further localize his/her geographical position and give rescue in the first time. Another feature of the system is its high anti-interference capability. In order to reduce 50Hz and RF interferences during mobile monitoring, which are usual much serious than conventional hospital monitoring, a new active recording technology was proposed and an active ECG recording electrode was designed. The system has passed the clinical test and used in China.

  3. Embroidered Electrode with Silver/Titanium Coating for Long-Term ECG Monitoring

    PubMed Central

    Weder, Markus; Hegemann, Dirk; Amberg, Martin; Hess, Markus; Boesel, Luciano F.; Abächerli, Roger; Meyer, Veronika R.; Rossi, René M.

    2015-01-01

    For the long-time monitoring of electrocardiograms, electrodes must be skin-friendly and non-irritating, but in addition they must deliver leads without artifacts even if the skin is dry and the body is moving. Today's adhesive conducting gel electrodes are not suitable for such applications. We have developed an embroidered textile electrode from polyethylene terephthalate yarn which is plasma-coated with silver for electrical conductivity and with an ultra-thin titanium layer on top for passivation. Two of these electrodes are embedded into a breast belt. They are moisturized with a very low amount of water vapor from an integrated reservoir. The combination of silver, titanium and water vapor results in an excellent electrode chemistry. With this belt the long-time monitoring of electrocardiography (ECG) is possible at rest as well as when the patient is moving. PMID:25599424

  4. The role of the ECG in diagnosis, risk estimation, and catheterization laboratory activation in patients with acute coronary syndromes: a consensus document.

    PubMed

    Birnbaum, Yochai; Nikus, Kjell; Kligfield, Paul; Fiol, Miguel; Barrabés, Jose Antonio; Sionis, Alessandro; Pahlm, Olle; Niebla, J Garcia; de Luna, Antonio Bayès

    2014-09-01

    The electrocardiogram (ECG) is the most widely used imaging tool helping in diagnosis and initial management of patients presenting with symptoms compatible with acute coronary syndrome. Acute ischemia affects the configuration of the QRS complexes, the ST segments and the T waves. The ECG should be read along with the clinical assessment of the patient. ST segment elevation (and ST depression in leads V1 -V3 ) in patients with active symptoms usually indicates acute occlusion of an epicardial artery with ongoing transmural ischemia. These patients should be triaged for emergent reperfusion therapy per current guidelines. However, many patients have ST segment elevation secondary to nonischemic causes. ST depression in leads other than V1 -V3 usually are indicative of subendocardial ischemia secondary to subocclusion of the epicardial artery, distal embolization to small arteries or spasm supply/demand mismatch. ST depression may also be secondary to nonischemic etiologies, such as left ventricular hypertrophy, cardiomyopathies, etc. Knowing the clinical scenario, comparison to previous ECG and subsequent ECGs (in cases that there are changes in the quality or severity of symptoms) may add in the diagnosis and interpretation in difficult cases. This review addresses the different ECG patterns, typically seen in patients with active symptoms, after resolution of symptoms and the significance of such changes when seen in asymptomatic patients.

  5. ECG Feature Extraction using Time Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Nair, Mahesh A.

    The proposed algorithm is a novel method for the feature extraction of ECG beats based on Wavelet Transforms. A combination of two well-accepted methods, Pan Tompkins algorithm and Wavelet decomposition, this system is implemented with the help of MATLAB. The focus of this work is to implement the algorithm, which can extract the features of ECG beats with high accuracy. The performance of this system is evaluated in a pilot study using the MIT-BIH Arrhythmia database.

  6. The ECG dilemma: guidelines on improving interpretation.

    PubMed

    Mele, Paul F

    2008-01-01

    The "ECG Dilemma" was recognized by the American College of Cardiology (ACC) and the American Heart Association more than 10 years ago. Estimates put the number of patients suffering from significant ECG interpretation errors every year in the same range as deaths from diabetes. Missed MI ranks in the top tier of malpractice dollars lost. Guidelines have been put forth to reduce these losses and improve patient safety and quality of care. These guidelines, and suggestions towards implementing them, are discussed.

  7. The Zigbee wireless ECG measurement system design with a motion artifact remove algorithm by using adaptive filter and moving weighted factor

    NASA Astrophysics Data System (ADS)

    Kwon, Hyeokjun; Oh, Sechang; Varadan, Vijay K.

    2012-04-01

    The Electrocardiogram(ECG) signal is one of the bio-signals to check body status. Traditionally, the ECG signal was checked in the hospital. In these days, as the number of people who is interesting with periodic their health check increase, the requirement of self-diagnosis system development is being increased as well. Ubiquitous concept is one of the solutions of the self-diagnosis system. Zigbee wireless sensor network concept is a suitable technology to satisfy the ubiquitous concept. In measuring ECG signal, there are several kinds of methods in attaching electrode on the body called as Lead I, II, III, etc. In addition, several noise components occurred by different measurement situation such as experimenter's respiration, sensor's contact point movement, and the wire movement attached on sensor are included in pure ECG signal. Therefore, this paper is based on the two kinds of development concept. The first is the Zibee wireless communication technology, which can provide convenience and simpleness, and the second is motion artifact remove algorithm, which can detect clear ECG signal from measurement subject. The motion artifact created by measurement subject's movement or even respiration action influences to distort ECG signal, and the frequency distribution of the noises is around from 0.2Hz to even 30Hz. The frequencies are duplicated in actual ECG signal frequency, so it is impossible to remove the artifact without any distortion of ECG signal just by using low-pass filter or high-pass filter. The suggested algorithm in this paper has two kinds of main parts to extract clear ECG signal from measured original signal through an electrode. The first part is to extract motion noise signal from measured signal, and the second part is to extract clear ECG by using extracted motion noise signal and measured original signal. The paper suggests several techniques in order to extract motion noise signal such as predictability estimation theory, low pass filter

  8. Smartphone home monitoring of ECG

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Hsu, Charles; Moon, Gyu; Landa, Joseph; Nakajima, Hiroshi; Hata, Yutaka

    2012-06-01

    A system of ambulatory, halter, electrocardiography (ECG) monitoring system has already been commercially available for recording and transmitting heartbeats data by the Internet. However, it enjoys the confidence with a reservation and thus a limited market penetration, our system was targeting at aging global villagers having an increasingly biomedical wellness (BMW) homecare needs, not hospital related BMI (biomedical illness). It was designed within SWaP-C (Size, Weight, and Power, Cost) using 3 innovative modules: (i) Smart Electrode (lowpower mixed signal embedded with modern compressive sensing and nanotechnology to improve the electrodes' contact impedance); (ii) Learnable Database (in terms of adaptive wavelets transform QRST feature extraction, Sequential Query Relational database allowing home care monitoring retrievable Aided Target Recognition); (iii) Smartphone (touch screen interface, powerful computation capability, caretaker reporting with GPI, ID, and patient panic button for programmable emergence procedure). It can provide a supplementary home screening system for the post or the pre-diagnosis care at home with a build-in database searchable with the time, the place, and the degree of urgency happened, using in-situ screening.

  9. ECG patch monitors for assessment of cardiac rhythm abnormalities.

    PubMed

    Lobodzinski, S Suave

    2013-01-01

    The primary goal of long-term monitoring is the improvement of diagnostic yield. Despite the clear utility of Holter monitoring in clinical cardiology, issues of relatively low diagnostic yield, cost and inconvenience have motivated the development of ultra-portable devices referred to as ECG patch monitors. Although the "gold standard" for assessing cardiac rhythm abnormalities remains a 12-lead Holter, there is an increasing interest in portable monitoring devices that provide the opportunity for evaluating cardiac rhythm in real-world environments such as the workplace or home. To facilitate patient acceptance these monitors underwent a radical miniaturization and redesign to include wireless communication, water proofing and a patch carrier for attaching devices directly to the skin. We review recent developments in the field of "patch" devices primarily designed for very long-term monitoring of cardiac arrhythmic events. As the body of supporting clinical validation data grows, these devices hold promise for a variety of cardiac monitoring applications. From a clinical and research standpoint, the capacity to obtain longitudinal cardiac activity data by patch devices may have significant implications for device selection, monitoring duration, and care pathways for arrhythmia evaluation and atrial fibrillation surveillance. From a research standpoint, the new devices may allow for the development of novel diagnostic algorithms with the goal of finding patterns and correlations with exercise and drug regimens.

  10. Compressed sensing of ECG signal for wireless system with new fast iterative method.

    PubMed

    Tawfic, Israa; Kayhan, Sema

    2015-12-01

    Recent experiments in wireless body area network (WBAN) show that compressive sensing (CS) is a promising tool to compress the Electrocardiogram signal ECG signal. The performance of CS is based on algorithms use to reconstruct exactly or approximately the original signal. In this paper, we present two methods work with absence and presence of noise, these methods are Least Support Orthogonal Matching Pursuit (LS-OMP) and Least Support Denoising-Orthogonal Matching Pursuit (LSD-OMP). The algorithms achieve correct support recovery without requiring sparsity knowledge. We derive an improved restricted isometry property (RIP) based conditions over the best known results. The basic procedures are done by observational and analytical of a different Electrocardiogram signal downloaded them from PhysioBankATM. Experimental results show that significant performance in term of reconstruction quality and compression rate can be obtained by these two new proposed algorithms, and help the specialist gathering the necessary information from the patient in less time if we use Magnetic Resonance Imaging (MRI) application, or reconstructed the patient data after sending it through the network. PMID:26428598

  11. A preliminary study of the effect of electrode placement in order to define a suitable location for two electrodes and obtain sufficiently reliable ECG signals when monitoring with wireless system.

    PubMed

    Noh, Hyung Wook; Jang, Yongwon; Lee, I B; Song, Yoonseon; Jeong, Ji-Wook; Lee, Sooyeul

    2012-01-01

    Most countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer. Therefore, there has been a promising market for portable ECG equipment and it is increasing. To use portable ECG measuring devices, it is essential to define a suitable location for the measuring as we need to reduced electrode size and distance. This research proposes to study how the inter-electrode distance affects the signal and how the electrode pair should be placed on the chest in order to obtain a sufficiently reliable ECG signal to detect heart arrhythmias in any environment, such as home or work. Therefore, we developed a compact, portable patch type ambulatory ECG monitoring system, Heart Tracker, using a microprocessor for preliminary study of signal analysis. To optimize the electrode arrangement in wireless environment, we compared HT and standard 12 lead with changing electrode position.

  12. SPEAR Trial: Smartphone Pediatric ElectrocARdiogram Trial

    PubMed Central

    Nguyen, Hoang H.; Van Hare, George F.; Rudokas, Michael; Bowman, Tammy; Silva, Jennifer N. A.

    2015-01-01

    Objectives Smartphone-enabled ECG devices have the potential to improve patient care by enabling remote ECG assessment of patients with potential and diagnosed arrhythmias. This prospective study aimed to assess the usefulness of pediatric ECG tracings generated by the AliveCor device (Oklahoma City, OK) and to assess user satisfaction. Study Design Enrolled pediatric patients with documented paroxysmal arrhythmia used the AliveCor device over a yearlong study period. Pediatric electrophysiologists reviewed all transmitted ECG tracings. Patient completed surveys were analyzed to assess user satisfaction. Results 35 patients were enrolled with the following diagnoses: supraventricular tachycardia (SVT, 57%), atrial fibrillation (AF, 11%), ectopic atrial tachycardia (EAT, 6%), atrial tachycardia (AT, 3%), and ventricular tachycardia (VT, 23%). A total of 238 tracings were received from 20 patients, 96% of which were of diagnostic quality for sinus rhythm, sinus tachycardia, SVT, and AF. 126 patient satisfaction surveys (64% from parents) were completed. 98% of the survey responses indicated that it was easy to obtain tracings, 93% found it easy to transmit the tracings, 98% showed added comfort in managing arrhythmia by having the device, and 93% showed interest in continued use of the device after the study period ended. Conclusions Smartphone-enabled ECG devices can generate tracings of diagnostic quality in children. User satisfaction was extremely positive. Use of the device to manage certain patients with AF and SVT showcases the future role of remote ECGs in the successful outpatient management of arrhythmias in children by potentially reducing Emergency Department visits and healthcare costs. PMID:26295569

  13. ECG compression using Slantlet and lifting wavelet transform with and without normalisation

    NASA Astrophysics Data System (ADS)

    Aggarwal, Vibha; Singh Patterh, Manjeet

    2013-05-01

    This article analyses the performance of: (i) linear transform: Slantlet transform (SLT), (ii) nonlinear transform: lifting wavelet transform (LWT) and (iii) nonlinear transform (LWT) with normalisation for electrocardiogram (ECG) compression. First, an ECG signal is transformed using linear transform and nonlinear transform. The transformed coefficients (TC) are then thresholded using bisection algorithm in order to match the predefined user-specified percentage root mean square difference (UPRD) within the tolerance. Then, the binary look up table is made to store the position map for zero and nonzero coefficients (NZCs). The NZCs are quantised by Max-Lloyd quantiser followed by Arithmetic coding. The look up table is encoded by Huffman coding. The results show that the LWT gives the best result as compared to SLT evaluated in this article. This transform is then considered to evaluate the effect of normalisation before thresholding. In case of normalisation, the TC is normalised by dividing the TC by ? (where ? is number of samples) to reduce the range of TC. The normalised coefficients (NC) are then thresholded. After that the procedure is same as in case of coefficients without normalisation. The results show that the compression ratio (CR) in case of LWT with normalisation is improved as compared to that without normalisation.

  14. Low-power wireless ECG acquisition and classification system for body sensor networks.

    PubMed

    Lee, Shuenn-Yuh; Hong, Jia-Hua; Hsieh, Cheng-Han; Liang, Ming-Chun; Chang Chien, Shih-Yu; Lin, Kuang-Hao

    2015-01-01

    A low-power biosignal acquisition and classification system for body sensor networks is proposed. The proposed system consists of three main parts: 1) a high-pass sigma delta modulator-based biosignal processor (BSP) for signal acquisition and digitization, 2) a low-power, super-regenerative on-off keying transceiver for short-range wireless transmission, and 3) a digital signal processor (DSP) for electrocardiogram (ECG) classification. The BSP and transmitter circuits, which are the body-end circuits, can be operated for over 80 days using two 605 mAH zinc-air batteries as the power supply; the power consumption is 586.5 μW. As for the radio frequency receiver and DSP, which are the receiving-end circuits that can be integrated in smartphones or personal computers, power consumption is less than 1 mW. With a wavelet transform-based digital signal processing circuit and a diagnosis control by cardiologists, the accuracy of beat detection and ECG classification are close to 99.44% and 97.25%, respectively. All chips are fabricated in TSMC 0.18-μm standard CMOS process. PMID:25561446

  15. Joint Feature Extraction and Classifier Design for ECG-Based Biometric Recognition.

    PubMed

    Gutta, Sandeep; Cheng, Qi

    2016-03-01

    Traditional biometric recognition systems often utilize physiological traits such as fingerprint, face, iris, etc. Recent years have seen a growing interest in electrocardiogram (ECG)-based biometric recognition techniques, especially in the field of clinical medicine. In existing ECG-based biometric recognition methods, feature extraction and classifier design are usually performed separately. In this paper, a multitask learning approach is proposed, in which feature extraction and classifier design are carried out simultaneously. Weights are assigned to the features within the kernel of each task. We decompose the matrix consisting of all the feature weights into sparse and low-rank components. The sparse component determines the features that are relevant to identify each individual, and the low-rank component determines the common feature subspace that is relevant to identify all the subjects. A fast optimization algorithm is developed, which requires only the first-order information. The performance of the proposed approach is demonstrated through experiments using the MIT-BIH Normal Sinus Rhythm database.

  16. Evolving a Bayesian Classifier for ECG-based Age Classification in Medical Applications.

    PubMed

    Wiggins, M; Saad, A; Litt, B; Vachtsevanos, G

    2008-01-01

    OBJECTIVE: To classify patients by age based upon information extracted from their electro-cardiograms (ECGs). To develop and compare the performance of Bayesian classifiers. METHODS AND MATERIAL: We present a methodology for classifying patients according to statistical features extracted from their ECG signals using a genetically evolved Bayesian network classifier. Continuous signal feature variables are converted to a discrete symbolic form by thresholding, to lower the dimensionality of the signal. This simplifies calculation of conditional probability tables for the classifier, and makes the tables smaller. Two methods of network discovery from data were developed and compared: the first using a greedy hill-climb search and the second employed evolutionary computing using a genetic algorithm (GA). RESULTS AND CONCLUSIONS: The evolved Bayesian network performed better (86.25% AUC) than both the one developed using the greedy algorithm (65% AUC) and the naïve Bayesian classifier (84.75% AUC). The methodology for evolving the Bayesian classifier can be used to evolve Bayesian networks in general thereby identifying the dependencies among the variables of interest. Those dependencies are assumed to be non-existent by naïve Bayesian classifiers. Such a classifier can then be used for medical applications for diagnosis and prediction purposes.

  17. Evolving a Bayesian Classifier for ECG-based Age Classification in Medical Applications

    PubMed Central

    Wiggins, M.; Saad, A.; Litt, B.; Vachtsevanos, G.

    2010-01-01

    Objective To classify patients by age based upon information extracted from their electro-cardiograms (ECGs). To develop and compare the performance of Bayesian classifiers. Methods and Material We present a methodology for classifying patients according to statistical features extracted from their ECG signals using a genetically evolved Bayesian network classifier. Continuous signal feature variables are converted to a discrete symbolic form by thresholding, to lower the dimensionality of the signal. This simplifies calculation of conditional probability tables for the classifier, and makes the tables smaller. Two methods of network discovery from data were developed and compared: the first using a greedy hill-climb search and the second employed evolutionary computing using a genetic algorithm (GA). Results and Conclusions The evolved Bayesian network performed better (86.25% AUC) than both the one developed using the greedy algorithm (65% AUC) and the naïve Bayesian classifier (84.75% AUC). The methodology for evolving the Bayesian classifier can be used to evolve Bayesian networks in general thereby identifying the dependencies among the variables of interest. Those dependencies are assumed to be non-existent by naïve Bayesian classifiers. Such a classifier can then be used for medical applications for diagnosis and prediction purposes. PMID:22010038

  18. ECG compression using non-recursive wavelet transform with quality control

    NASA Astrophysics Data System (ADS)

    Liu, Je-Hung; Hung, King-Chu; Wu, Tsung-Ching

    2016-09-01

    While wavelet-based electrocardiogram (ECG) data compression using scalar quantisation (SQ) yields excellent compression performance, a wavelet's SQ scheme, however, must select a set of multilevel quantisers for each quantisation process. As a result of the properties of multiple-to-one mapping, however, this scheme is not conducive for reconstruction error control. In order to address this problem, this paper presents a single-variable control SQ scheme able to guarantee the reconstruction quality of wavelet-based ECG data compression. Based on the reversible round-off non-recursive discrete periodised wavelet transform (RRO-NRDPWT), the SQ scheme is derived with a three-stage design process that first uses genetic algorithm (GA) for high compression ratio (CR), followed by a quadratic curve fitting for linear distortion control, and the third uses a fuzzy decision-making for minimising data dependency effect and selecting the optimal SQ. The two databases, Physikalisch-Technische Bundesanstalt (PTB) and Massachusetts Institute of Technology (MIT) arrhythmia, are used to evaluate quality control performance. Experimental results show that the design method guarantees a high compression performance SQ scheme with statistically linear distortion. This property can be independent of training data and can facilitate rapid error control.

  19. Demonstration of a fully differential VGA chip with small THD for ECG acquisition system

    NASA Astrophysics Data System (ADS)

    Gongli, Xiao; Yuliang, Qin; Weilin, Xu; Baolin, Wei; Jihai, Duan; Xueming, Wei

    2015-10-01

    We present both a theoretical and experimental demonstration of a fully differential variable gain amplifier (VGA) with small total harmonic distortion (THD) for an electrocardiogram (ECG) acquisition system. Capacitive feedback technology is adopted to reduce the nonlinearity of VGA. The fully differential VGA has been fabricated in SMIC 0.18-μm CMOS process, and it only occupies 0.11 mm2. The measurements are in good agreement with simulation results. Experimental results show that the gain of VGA changes from 6.17 to 43.75 dB with a gain step of 3 dB. The high-pass corner frequency and low-pass corner frequency are around 0.22 Hz and 7.9 kHz, respectively. For each gain configuration, a maximal THD of 0.13% is obtained. The fully differential VGA has a low THD and its key performance parameters are well satisfied with the demands of ECG acquisition system application in the UWB wireless body area network. Project supported by the National Natural Science Foundation of China (Nos. 61264001, 61465004, 61161003, 61166004), the Guangxi Natural Science Foundation (Nos. 2013GXNSFAA019333, 2013GXNSFAA019338), the Science and Technology Research Key Project of Guangxi Department of Education (No. 2013ZD026), and the Innovation Project of GUET Graduate Education (No. GDYCSZ201457).

  20. Detection of segments with fetal QRS complex from abdominal maternal ECG recordings using support vector machine

    NASA Astrophysics Data System (ADS)

    Delgado, Juan A.; Altuve, Miguel; Nabhan Homsi, Masun

    2015-12-01

    This paper introduces a robust method based on the Support Vector Machine (SVM) algorithm to detect the presence of Fetal QRS (fQRS) complexes in electrocardiogram (ECG) recordings provided by the PhysioNet/CinC challenge 2013. ECG signals are first segmented into contiguous frames of 250 ms duration and then labeled in six classes. Fetal segments are tagged according to the position of fQRS complex within each one. Next, segment features extraction and dimensionality reduction are obtained by applying principal component analysis on Haar-wavelet transform. After that, two sub-datasets are generated to separate representative segments from atypical ones. Imbalanced class problem is dealt by applying sampling without replacement on each sub-dataset. Finally, two SVMs are trained and cross-validated using the two balanced sub-datasets separately. Experimental results show that the proposed approach achieves high performance rates in fetal heartbeats detection that reach up to 90.95% of accuracy, 92.16% of sensitivity, 88.51% of specificity, 94.13% of positive predictive value and 84.96% of negative predictive value. A comparative study is also carried out to show the performance of other two machine learning algorithms for fQRS complex estimation, which are K-nearest neighborhood and Bayesian network.

  1. [Measurement of coefficient of variation of R-R interval in ECG for patients with impotence].

    PubMed

    Takasaki, N; Kotani, T; Miyazaki, S; Saitou, S

    1989-08-01

    The coefficient of variation (CV = SD/mean x 100) of the R-R interval in electrocardiogram (ECG) was measured as an indication of parasympathetic nerve function in patients with impotence. Of 762 patients 104 (13.6%) had a CV value lower than 2.0. The factors which led to the low CV value were evident in 50 patients (48%), i.e. diabetes mellitus in 26, side effects by antiulcer, antidepressant or antihypertensive agent in 16, renal failure in 1, alcoholism in 2 and age over 70 years old in 4. The possible factors of the low CV value, such as neurogenic, thyroid, cardiovascular and endocrine disorders were found in 12 patients (11.5%). In the remaining 42 patients (40.4%), CV value was decreased by unknown factors. Measurement of CV of R-R interval in ECG was safe and useful as a screening test for patients with impotence to detect the dysfunction of the parasympathetic nerve system.

  2. Estimating the measuring sensitivity of unipolar and bipolar ECG with lead field method and FDM models.

    PubMed

    Puurtinen, Merja; Viik, Jari; Takano, Noriyuki; Malmivuo, Jaakko; Hyttinen, Jari

    2009-05-01

    New portable electrocardiogram (ECG) measurement systems are emerging into market. Some use nonstandard bipolar electrode montage and sometimes very small interelectrode distances to improve the usability of the system. Modeling could provide a straightforward method to test new electrode systems. The aim of this study was to assess whether modeling the electrodes' measuring sensitivity with lead field method can provide a simple tool for testing a number of new electrode locations. We evaluated whether the actual ECG signal strength can be estimated by lead fields with two realistic 3D finite difference method (FDM) thorax models. We compared the modeling results to clinical body surface potential map (BSPM) data from 236 normal patients and studied 117 unipolar and 42 bipolar leads. In the case of unipolar electrodes the modeled measuring sensitivities correlated well with the clinical data (r=0.86, N=117, p<0.05). In the case of bipolar electrodes the correlation was moderate (r=0.62 between Model 1 and clinical data, r=0.71 between Model 2 and clinical data, N=42 and p<0.05 for both). Based on this we can conclude that lead field analysis based on realistic thorax models provides a good initial prediction for designing new electrode montages and measurement systems.

  3. Joint Feature Extraction and Classifier Design for ECG-Based Biometric Recognition.

    PubMed

    Gutta, Sandeep; Cheng, Qi

    2016-03-01

    Traditional biometric recognition systems often utilize physiological traits such as fingerprint, face, iris, etc. Recent years have seen a growing interest in electrocardiogram (ECG)-based biometric recognition techniques, especially in the field of clinical medicine. In existing ECG-based biometric recognition methods, feature extraction and classifier design are usually performed separately. In this paper, a multitask learning approach is proposed, in which feature extraction and classifier design are carried out simultaneously. Weights are assigned to the features within the kernel of each task. We decompose the matrix consisting of all the feature weights into sparse and low-rank components. The sparse component determines the features that are relevant to identify each individual, and the low-rank component determines the common feature subspace that is relevant to identify all the subjects. A fast optimization algorithm is developed, which requires only the first-order information. The performance of the proposed approach is demonstrated through experiments using the MIT-BIH Normal Sinus Rhythm database. PMID:25680220

  4. Detection of fiducial points in ECG waves using iteration based adaptive thresholds.

    PubMed

    Wonjune Kang; Kyunguen Byun; Hong-Goo Kang

    2015-08-01

    This paper presents an algorithm for the detection of fiducial points in electrocardiogram (ECG) waves using iteration based adaptive thresholds. By setting the search range of the processing frame to the interval between two consecutive R peaks, the peaks of T and P waves are used as reference salient points (RSPs) to detect the fiducial points. The RSPs are selected from candidates whose slope variation factors are larger than iteratively defined adaptive thresholds. Considering the fact that the number of RSPs varies depending on whether the ECG wave is normal or not, the proposed algorithm proceeds with a different methodology for determining fiducial points based on the number of detected RSPs. Testing was performed using twelve records from the MIT-BIH Arrhythmia Database that were manually marked for comparison with the estimated locations of the fiducial points. The means of absolute distances between the true locations and the points estimated by the algorithm are 12.2 ms and 7.9 ms for the starting points of P and Q waves, and 9.3 ms and 13.9 ms for the ending points of S and T waves. Since the computational complexity of the proposed algorithm is very low, it is feasible for use in mobile devices. PMID:26736854

  5. Investigation of ECG Changes in Absence Epilepsy on WAG/Rij Rats

    PubMed Central

    Es'haghi, Fatemeh; Shahabi, Parviz; Frounchi, Javad; Sadighi, Mina; Yousefi, Hadi

    2015-01-01

    Introduction: Seizures are symptoms associated with abnormal electrical activity in electroencephalogram (EEG). The present study was designed to determine the effect of absence seizure on heart rate (HR) changes in electrocardiogram (ECG). Methods: HR alterations were recorded simultaneous with spike and wave discharges (SWD) by EEG in 6 WAG/Rij rats as a well characterized and validated genetic animal epilepsy model. Moreover, 6 control rats were used to distinguish the differences of HR changes between various groups. Electrodes were placed on the skull and under the chest skin, minimizing time delay and signal attenuation. HR was calculated by an adaptable algorithm based on continues wavelet transform (CWT) particular for this study. Three main features of HR; minimum, maximum, and mean values were estimated for pre-ictal and ictal intervals for all seizures. Results: ECG beats detected with sensitivity of 99.9% and positive predictability of 99.8% based on CWT. HR deceleration was found in 86% of the seizures. There were statistically significant (P<0.001) reductions of these values from pre-ictal to ictal intervals. Interictal HR acceleration and ictal deceleration were the major feature of alterations and in 23% of seizures, this decrease had priority to the onsets. Discussion: These findings may lead to design a seizure alarm system based on HR and to obtain new insights about sudden unexpected death in epilepsy (SUDEP) phenomenon and side-effects of antiepileptic drugs (AED). PMID:27307957

  6. A novel biometric authentication approach using electrocardiogram signals.

    PubMed

    Gürkan, Hakan; Guz, Umit; Yarman, B S

    2013-01-01

    In this work, we present a novel biometric authentication approach based on combination of AC/DCT features, MFCC features, and QRS beat information of the ECG signals. The proposed approach is tested on a subset of 30 subjects selected from the PTB database. This subset consists of 13 healthy and 17 non-healthy subjects who have two ECG records. The proposed biometric authentication approach achieves average frame recognition rate of %97.31 on the selected subset. Our experimental results imply that the frame recognition rate of the proposed authentication approach is better than that of ACDCT and MFCC based biometric authentication systems, individually. PMID:24110673

  7. Estimating actigraphy from motion artifacts in ECG and respiratory effort signals.

    PubMed

    Fonseca, Pedro; Aarts, Ronald M; Long, Xi; Rolink, Jérôme; Leonhardt, Steffen

    2016-01-01

    Recent work in unobtrusive sleep/wake classification has shown that cardiac and respiratory features can help improve classification performance. Nevertheless, actigraphy remains the single most discriminative modality for this task. Unfortunately, it requires the use of dedicated devices in addition to the sensors used to measure electrocardiogram (ECG) or respiratory effort. This paper proposes a method to estimate actigraphy from the body movement artifacts present in the ECG and respiratory inductance plethysmography (RIP) based on the time-frequency analysis of those signals. Using a continuous wavelet transform to analyze RIP, and ECG and RIP combined, it provides a surrogate measure of actigraphy with moderate correlation (for ECG+RIP, ρ = 0.74, p  <  0.001) and agreement (mean bias ratio of 0.94 and 95% agreement ratios of 0.11 and 8.45) with reference actigraphy. More important, it can be used as a replacement of actigraphy in sleep/wake classification: after cross-validation with a data set comprising polysomnographic (PSG) recordings of 15 healthy subjects and 25 insomniacs annotated by an external sleep technician, it achieves a statistically non-inferior classification performance when used together with respiratory features (average κ of 0.64 for 15 healthy subjects, and 0.50 for a dataset with 40 healthy and insomniac subjects), and when used together with respiratory and cardiac features (average κ of 0.66 for 15 healthy subjects, and 0.56 for 40 healthy and insomniac subjects). Since this method eliminates the need for a dedicated actigraphy device, it reduces the number of sensors needed for sleep/wake classification to a single sensor when using respiratory features, and to two sensors when using respiratory and cardiac features without any loss in performance. It offers a major benefit in terms of comfort for long-term home monitoring and is immediately applicable for legacy ECG and RIP monitoring devices already used in clinical

  8. ECG phenomena: pseudopreexcitation and repolarization disturbances resembling ST-elevation myocardial infarction caused by an intraatrial rhabdomyoma in a newborn.

    PubMed

    Paech, Christian; Gebauer, Roman Antonin

    2014-01-01

    As is known from other reports, a rhabdomyoma or tumor metastasis may alter intracardiac electrical conduction, producing electrical phenomena like pseudopreexcitation or repolarization disturbances resembling ST-elevation myocardial infarction or Brugada's syndrome. We present a newborn with a giant atrial rhabdomyoma and additionally multiple ventricular rhabdomyomas. He presented with several electrocardiogram (ECG) phenomena due to tumor-caused atrial depolarization and repolarization disturbances. Except from the cardiac tumors, the physical status was within normal range. Initial ECG showed a rapid atrial tachycardia with a ventricular rate of 230 bpm, which was terminated by electrical cardioversion. Afterwards, the ECG showed atrial rhythm with frequent atrial premature contractions and deformation of the PR interval with large, broad P waves and loss of discret PR segment, imposing as pseudopreexcitation. The following QRS complex was normal, with seemingly abnormal ventricular repolarization resembeling ST-elevation myocardial infarction. The atrial tumor was resected with consequent vast atrial reconstruction using patch plastic. The ventricular tumors were left without manipulation. After surgery, pseudopreexcitation and repolarization abnormalities vanished entirely and an alternans between sinus rhythm and ectopic atrial rhythm was present. These phenomena were supposably caused by isolated atrial depolarization disturbances due to tumor-caused heterogenous endocardial activation. The seemingly abnormal ventricular repolarization is probably due to repolarization of the atrial mass, superimposed on the ventricular repolarization. Recognizably, the QRS complex before and after surgical resection of the rhabdomyoma is identical, underlining the atrial origin of the repolarization abnormalities before surgery.

  9. Combined ECG, Echocardiographic, and Biomarker Criteria for Diagnosing Acute Myocardial Infarction in Out-of-Hospital Cardiac Arrest Patients

    PubMed Central

    Lee, Sang-Eun; Uhm, Jae-Sun; Kim, Jong-Youn; Pak, Hui-Nam; Lee, Moon-Hyoung

    2015-01-01

    Purpose Acute coronary lesions commonly trigger out-of-hospital cardiac arrest (OHCA). However, the prevalence of coronary artery disease (CAD) in Asian patients with OHCA and whether electrocardiogram (ECG) and other findings might predict acute myocardial infarction (AMI) have not been fully elucidated. Materials and Methods Of 284 consecutive resuscitated OHCA patients seen between January 2006 and July 2013, we enrolled 135 patients who had undergone coronary evaluation. ECGs, echocardiography, and biomarkers were compared between patients with or without CAD. Results We included 135 consecutive patients aged 54 years (interquartile range 45-65) with sustained return of spontaneous circulation after OHCA between 2006 and 2012. Sixty six (45%) patients had CAD. The initial rhythm was shockable and non-shockable in 110 (81%) and 25 (19%) patients, respectively. ST-segment elevation predicted CAD with 42% sensitivity, 87% specificity, and 65% accuracy. ST elevation and/or regional wall motion abnormality (RWMA) showed 68% sensitivity, 52% specificity, and 70% accuracy in the prediction of CAD. Finally, a combination of ST elevation and/or RWMA and/or troponin T elevation predicted CAD with 94% sensitivity, 17% specificity, and 55% accuracy. Conclusion In patients with OHCA without obvious non-cardiac causes, selection for coronary angiogram based on the combined criterion could detect 94% of CADs. However, compared with ECG only criteria, the combined criterion failed to improve diagnostic accuracy with a lower specificity. PMID:26069108

  10. ECG changes in factory workers exposed to 27.2  MHz radiofrequency radiation.

    PubMed

    Chen, Qingsong; Xu, Guoyong; Lang, Li; Yang, Aichu; Li, Shilin; Yang, Liwen; Li, Chaolin; Huang, Hanlin; Li, Tao

    2013-05-01

    To research the effect of 27.2 MHz radiofrequency radiation on electrocardiograms (ECG), 225 female workers operating radiofrequency machines at a shoe factory were chosen as the exposure group and 100 female workers without exposure from the same factory were selected as the control group. The 6 min electric field strength that the female workers were exposed to was 64.0 ± 25.2 V/m (mean ± SD), which exceeded 61 V/m, the International Commission on Non-Ionizing Radiation Protection reference root mean square levels for occupational exposure. A statistical difference was observed between the exposed group and the control group in terms of the rate of sinus bradycardia (χ(2)  = 11.48, P = 0.003). When several known risk factors for cardiovascular disease were considered, including smoking, age, alcohol ingestion habit, and so on, the exposure duration was not an effective factor for ECG changes, sinus arrhythmia, or sinus bradycardia according to α = 0.05, while P = 0.052 for sinus arrhythmia was very close to 0.05. We did not find any statistical difference in heart rate, duration of the QRS wave (ventricular depolarization), or corrected QT intervals (between the start of the Q wave and end of the T wave) between the exposed and control groups. Occupational exposure to radiofrequency radiation was not found to be a cause of ECG changes after consideration of the confounding factors.

  11. Resuscitation great. Willem Einthoven: the development of the human electrocardiogram.

    PubMed

    Cajavilca, Christian; Varon, Joseph

    2008-03-01

    The electrocardiogram is one of the most commonly used diagnostic tools in healthcare. This ingenious device was developed and created in the early 1900s by Willem Einthoven, MD, PhD after studying the mechanisms of electromagnetism and Waller's capillary electrometer. Einthoven dedicated most of his research and clinical activities to improve the early versions of the electrical current recording medical devices. Einthoven's most notable invention was the string galvanometer which we now know as the electrocardiogram. Although the idea of using the string galvanometer as a diagnostic tool faced opposition by scientists and physicians of his time, he remained convinced of the potential of his machine to improve patient care. Einthoven's string galvanometer subsequently became the standard diagnostic tool for recognition and differentiation of heart conditions through the interpretation of cardiac waves, and has become standard practice in the field of resuscitation. In 1924, Einthoven received the Nobel Prize in Medicine for his development of the string galvanometer.

  12. Resuscitation great. Willem Einthoven: the development of the human electrocardiogram.

    PubMed

    Cajavilca, Christian; Varon, Joseph

    2008-03-01

    The electrocardiogram is one of the most commonly used diagnostic tools in healthcare. This ingenious device was developed and created in the early 1900s by Willem Einthoven, MD, PhD after studying the mechanisms of electromagnetism and Waller's capillary electrometer. Einthoven dedicated most of his research and clinical activities to improve the early versions of the electrical current recording medical devices. Einthoven's most notable invention was the string galvanometer which we now know as the electrocardiogram. Although the idea of using the string galvanometer as a diagnostic tool faced opposition by scientists and physicians of his time, he remained convinced of the potential of his machine to improve patient care. Einthoven's string galvanometer subsequently became the standard diagnostic tool for recognition and differentiation of heart conditions through the interpretation of cardiac waves, and has become standard practice in the field of resuscitation. In 1924, Einthoven received the Nobel Prize in Medicine for his development of the string galvanometer. PMID:18164799

  13. Intermittent short ECG recording is more effective than 24-hour Holter ECG in detection of arrhythmias

    PubMed Central

    2014-01-01

    Background Many patients report symptoms of palpitations or dizziness/presyncope. These patients are often referred for 24-hour Holter ECG, although the sensitivity for detecting relevant arrhythmias is comparatively low. Intermittent short ECG recording over a longer time period might be a convenient and more sensitive alternative. The objective of this study is to compare the efficacy of 24-hour Holter ECG with intermittent short ECG recording over four weeks to detect relevant arrhythmias in patients with palpitations or dizziness/presyncope. Methods Design: prospective, observational, cross-sectional study. Setting: Clinical Physiology, University Hospital. Patients: 108 consecutive patients referred for ambiguous palpitations or dizziness/presyncope. Interventions: All individuals underwent a 24-hour Holter ECG and additionally registered 30-second handheld ECG (Zenicor EKG® thumb) recordings at home, twice daily and when having cardiac symptoms, during 28 days. Main outcome measures: Significant arrhythmias: atrial fibrillation (AF), paroxysmal supraventricular tachycardia (PSVT), atrioventricular (AV) block II–III, sinus arrest (SA), wide complex tachycardia (WCT). Results 95 patients, 42 men and 53 women with a mean age of 54.1 years, completed registrations. Analysis of Holter registrations showed atrial fibrillation (AF) in two patients and atrioventricular (AV) block II in one patient (= 3.2% relevant arrhythmias [95% CI 1.1–8.9]). Intermittent handheld ECG detected nine patients with AF, three with paroxysmal supraventricular tachycardia (PSVT) and one with AV-block-II (= 13.7% relevant arrhythmias [95% CI 8.2–22.0]). There was a significant difference between the two methods in favour of intermittent ECG with regard to the ability to detect relevant arrhythmias (P = 0.0094). With Holter ECG, no symptoms were registered during any of the detected arrhythmias. With intermittent ECG, symptoms were registered during half of the arrhythmia

  14. The influence of novel CT reconstruction technique and ECG-gated technique on image quality and patient dose of cardiac computed tomography.

    PubMed

    Dyakov, I; Stoinova, V; Groudeva, V; Vassileva, J

    2015-07-01

    The aim of the present study was to compare image quality and patient dose in cardiac computed tomography angiography (CTA) in terms of volume computed tomography dose index (CTDI vol), dose length product (DLP) and effective dose, when changing from filtered back projection (FBP) to adaptive iterative dose reduction (AIDR) reconstruction techniques. Further aim was to implement prospective electrocardiogram (ECG) gating for patient dose reduction. The study was performed with Aquilion ONE 320-row CT of Toshiba Medical Systems. Analysis of cardiac CT protocols was performed before and after integration of the new software. The AIDR technique showed more than 50 % reduction in CTDIvol values and 57 % in effective dose. The subjective evaluation of clinical images confirmed the adequate image quality acquired by the AIDR technique. The preliminary results indicated significant dose reduction when using prospective ECG gating by keeping the adequate diagnostic quality of clinical images. PMID:25836680

  15. [Implementation of ECG Monitoring System Based on Internet of Things].

    PubMed

    Lu, Liangliang; Chen, Minya

    2015-11-01

    In order to expand the capabilities of hospital's traditional ECG device and enhance medical staff's work efficiency, an ECG monitoring system based on internet of things is introduced. The system can monitor ECG signals in real time and analyze data using ECG sensor, PDA, Web servers, which embeds C language, Android systems, .NET, wireless network and other technologies. After experiments, it can be showed that the system has high reliability and stability and can bring the convenience to medical staffs.

  16. [Implementation of ECG Monitoring System Based on Internet of Things].

    PubMed

    Lu, Liangliang; Chen, Minya

    2015-11-01

    In order to expand the capabilities of hospital's traditional ECG device and enhance medical staff's work efficiency, an ECG monitoring system based on internet of things is introduced. The system can monitor ECG signals in real time and analyze data using ECG sensor, PDA, Web servers, which embeds C language, Android systems, .NET, wireless network and other technologies. After experiments, it can be showed that the system has high reliability and stability and can bring the convenience to medical staffs. PMID:27066681

  17. A Combination Method for Electrocardiogram Rejection from Surface Electromyogram

    PubMed Central

    Abbaspour, Sara; Fallah, Ali

    2014-01-01

    The electrocardiogram signal which represents the electrical activity of the heart provides interference in the recording of the electromyogram signal, when the electromyogram signal is recorded from muscles close to the heart. Therefore, due to impurities, electromyogram signals recorded from this area cannot be used. In this paper, a new method was developed using a combination of artificial neural network and wavelet transform approaches, to eliminate the electrocardiogram artifact from electromyogram signals and improve results. For this purpose, contaminated signal is initially cleaned using the neural network. With this process, a large amount of noise can be removed. However, low-frequency noise components remain in the signal that can be removed using wavelet. Finally, the result of the proposed method is compared with other methods that were used in different papers to remove electrocardiogram from electromyogram. In this paper in order to compare methods, qualitative and quantitative criteria such as signal to noise ratio, relative error, power spectrum density and coherence have been investigated for evaluation and comparison. The results of signal to noise ratio and relative error are equal to 15.6015 and 0.0139, respectively. PMID:24772195

  18. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  19. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  20. Multichannel ECG and Noise Modeling: Application to Maternal and Fetal ECG Signals

    NASA Astrophysics Data System (ADS)

    Sameni, Reza; Clifford, Gari D.; Jutten, Christian; Shamsollahi, Mohammad B.

    2007-12-01

    A three-dimensional dynamic model of the electrical activity of the heart is presented. The model is based on the single dipole model of the heart and is later related to the body surface potentials through a linear model which accounts for the temporal movements and rotations of the cardiac dipole, together with a realistic ECG noise model. The proposed model is also generalized to maternal and fetal ECG mixtures recorded from the abdomen of pregnant women in single and multiple pregnancies. The applicability of the model for the evaluation of signal processing algorithms is illustrated using independent component analysis. Considering the difficulties and limitations of recording long-term ECG data, especially from pregnant women, the model described in this paper may serve as an effective means of simulation and analysis of a wide range of ECGs, including adults and fetuses.

  1. Preprocessing and analysis of the ECG signals

    NASA Astrophysics Data System (ADS)

    Zhu, Jianmin; Zhang, Xiaolan; Wang, Zhongyu; Wang, Xiaoling

    2008-10-01

    According to the request of automatic analysis and depressing high frequency interference of the ECG signals, this paper applies low-pass filter to preprocess ECG signals, and proposes a QRS complex detection method based on wavelet transform, which takes advantage of Marr wavelet to decompose and filter the ECG signals with Mallat algorithm, using the relationship between wavelet transform and signal singularity to detect QRS complex with amplitude threshold method in scale 3, and to detect P wave and R wave in scale 4. Meanwhile, compositive detection method is used for re-detection, thus to improving the detection accuracy ratio. At last, records from ECG database of MIT/BIH which is widely accepted in the world are used to test the algorithm. And the result shows that correction detecting ratio under this algorithm has been more than 99.8 percent. The detection method in this paper is simple and running fast, and is easy to be realized in the real-time detecting system using for clinical diagnosis.

  2. A Mathematical Model for Segmenting ECG Signals

    NASA Astrophysics Data System (ADS)

    Feier, Horea; Roşu, Doina; Falniţǎ, Lucian; Roşu, Şerban; Pater, Liana

    2010-09-01

    This paper deals with the behavior of the modulus of the continuous wavelet transform (CWT) for some known mother wavelets like the Morlet wavelet and the Mexican Hat. By exploiting these properties, the models presented can behave as a segmentation/ recognition signal processing tool by modeling the temporal structure of the observed surface ECG.

  3. Novel electrodes for underwater ECG monitoring.

    PubMed

    Reyes, Bersain A; Posada-Quintero, Hugo F; Bales, Justin R; Clement, Amanda L; Pins, George D; Swiston, Albert; Riistama, Jarno; Florian, John P; Shykoff, Barbara; Qin, Michael; Chon, Ki H

    2014-06-01

    We have developed hydrophobic electrodes that provide all morphological waveforms without distortion of an ECG signal for both dry and water-immersed conditions. Our electrode is comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS). For feasibility testing of the CB/PDMS electrodes, various tests were performed. One of the tests included evaluation of the electrode-to-skin contact impedance for different diameters, thicknesses, and different pressure levels. As expected, the larger the diameter of the electrodes, the lower the impedance and the difference between the large sized CB/PDMS and the similarly-sized Ag/AgCl hydrogel electrodes was at most 200 kΩ, in favor of the latter. Performance comparison of CB/PDMS electrodes to Ag/AgCl hydrogel electrodes was carried out in three different scenarios: a dry surface, water immersion, and postwater immersion conditions. In the dry condition, no statistical differences were found for both the temporal and spectral indices of the heart rate variability analysis between the CB/PDMS and Ag/AgCl hydrogel (p > 0.05) electrodes. During water immersion, there was significant ECG amplitude reduction with CB/PDMS electrodes when compared to wet Ag/AgCl electrodes kept dry by their waterproof adhesive tape, but the reduction was not severe enough to obscure the readability of the recordings, and all morphological waveforms of the ECG signal were discernible even when motion artifacts were introduced. When water did not penetrate tape-wrapped Ag/AgCl electrodes, high fidelity ECG signals were observed. However, when water penetrated the Ag/AgCl electrodes, the signal quality degraded to the point where ECG morphological waveforms were not discernible.

  4. Novel electrodes for underwater ECG monitoring.

    PubMed

    Reyes, Bersain A; Posada-Quintero, Hugo F; Bales, Justin R; Clement, Amanda L; Pins, George D; Swiston, Albert; Riistama, Jarno; Florian, John P; Shykoff, Barbara; Qin, Michael; Chon, Ki H

    2014-06-01

    We have developed hydrophobic electrodes that provide all morphological waveforms without distortion of an ECG signal for both dry and water-immersed conditions. Our electrode is comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS). For feasibility testing of the CB/PDMS electrodes, various tests were performed. One of the tests included evaluation of the electrode-to-skin contact impedance for different diameters, thicknesses, and different pressure levels. As expected, the larger the diameter of the electrodes, the lower the impedance and the difference between the large sized CB/PDMS and the similarly-sized Ag/AgCl hydrogel electrodes was at most 200 kΩ, in favor of the latter. Performance comparison of CB/PDMS electrodes to Ag/AgCl hydrogel electrodes was carried out in three different scenarios: a dry surface, water immersion, and postwater immersion conditions. In the dry condition, no statistical differences were found for both the temporal and spectral indices of the heart rate variability analysis between the CB/PDMS and Ag/AgCl hydrogel (p > 0.05) electrodes. During water immersion, there was significant ECG amplitude reduction with CB/PDMS electrodes when compared to wet Ag/AgCl electrodes kept dry by their waterproof adhesive tape, but the reduction was not severe enough to obscure the readability of the recordings, and all morphological waveforms of the ECG signal were discernible even when motion artifacts were introduced. When water did not penetrate tape-wrapped Ag/AgCl electrodes, high fidelity ECG signals were observed. However, when water penetrated the Ag/AgCl electrodes, the signal quality degraded to the point where ECG morphological waveforms were not discernible. PMID:24845297

  5. The Development of a Portable ECG Monitor Based on DSP

    NASA Astrophysics Data System (ADS)

    Nan, CHI Jian; Tao, YAN Yan; Meng Chen, LIU; Li, YANG

    With the advent of global information, researches of Smart Home system are in the ascendant, the ECG real-time detection, and wireless transmission of ECG become more useful. In order to achieve the purpose we developed a portable ECG monitor which achieves the purpose of cardiac disease remote monitoring, and will be used in the physical and psychological disease surveillance in smart home system, we developed this portable ECG Monitor, based on the analysis of existing ECG Monitor, using TMS320F2812 as the core controller, which complete the signal collection, storage, processing, waveform display and transmission.

  6. Sparse Matrix for ECG Identification with Two-Lead Features

    PubMed Central

    Tseng, Kuo-Kun; Luo, Jiao; Wang, Wenmin; Haiting, Dong

    2015-01-01

    Electrocardiograph (ECG) human identification has the potential to improve biometric security. However, improvements in ECG identification and feature extraction are required. Previous work has focused on single lead ECG signals. Our work proposes a new algorithm for human identification by mapping two-lead ECG signals onto a two-dimensional matrix then employing a sparse matrix method to process the matrix. And that is the first application of sparse matrix techniques for ECG identification. Moreover, the results of our experiments demonstrate the benefits of our approach over existing methods. PMID:25961074

  7. [Development of multi-function ECG signal generator].

    PubMed

    Cheng, F; Wei, Y X

    2000-07-01

    This paper describes the development of a portable multi-function ECG signal generator, which is based on micro-controller. It uses technique of LCD screen, and realizes man-machine interaction by keyboard. In constructing and disposing data module of the ECG signal, Eigen-heartbeat Code mapping method gets ROM saved greatly. Therefore it can generate all kinds of user-defined ECG signal sequence with no extension of on-board memory chips. This system can also simulate kinds of ECG signals, which have various heart rates and symptoms. It can meet the needs of researching and maintenance of kinds of ECG instruments. PMID:12583134

  8. Validation of PC-based Sound Card with Biopac for Digitalization of ECG Recording in Short-term HRV Analysis

    PubMed Central

    Maheshkumar, K.; Dilara, K.; Maruthy, K. N.; Sundareswaren, L.

    2016-01-01

    Background: Heart rate variability (HRV) analysis is a simple and noninvasive technique capable of assessing autonomic nervous system modulation on heart rate (HR) in healthy as well as disease conditions. The aim of the present study was to compare (validate) the HRV using a temporal series of electrocardiograms (ECG) obtained by simple analog amplifier with PC-based sound card (audacity) and Biopac MP36 module. Materials and Methods: Based on the inclusion criteria, 120 healthy participants, including 72 males and 48 females, participated in the present study. Following standard protocol, 5-min ECG was recorded after 10 min of supine rest by Portable simple analog amplifier PC-based sound card as well as by Biopac module with surface electrodes in Leads II position simultaneously. All the ECG data was visually screened and was found to be free of ectopic beats and noise. RR intervals from both ECG recordings were analyzed separately in Kubios software. Short-term HRV indexes in both time and frequency domain were used. Results: The unpaired Student's t-test and Pearson correlation coefficient test were used for the analysis using the R statistical software. No statistically significant differences were observed when comparing the values analyzed by means of the two devices for HRV. Correlation analysis revealed perfect positive correlation (r = 0.99, P < 0.001) between the values in time and frequency domain obtained by the devices. Conclusion: On the basis of the results of the present study, we suggest that the calculation of HRV values in the time and frequency domains by RR series obtained from the PC-based sound card is probably as reliable as those obtained by the gold standard Biopac MP36. PMID:27583239

  9. Multiobjective optimization-based design of wearable electrocardiogram monitoring systems.

    PubMed

    Martinez-Tabares, F J; Jaramillo-Garzón, J A; Castellanos-Dominguez, G

    2014-01-01

    Nowadays, the use of Wearable User Interfaces has been extensively growing in medical monitoring applications. However, production and manufacture of prototypes without automation tools may lead to non viable results since it is often common to find an optimization problem where several variables are in conflict with each other. Thus, it is necessary to design a strategy for balancing the variables and constraints, systematizing the design in order to reduce the risks that are present when it is exclusively guided by the intuition of the developer. This paper proposes a framework for designing wearable ECG monitoring systems using multi-objective optimization. The main contributions of this work are the model to automate the design process, including a mathematical expression relating the principal variables that make up the criteria of functionality and wearability. We also introduce a novel yardstick for deciding the location of electrodes, based on reducing interference from ECG by maximizing the electrode-skin contact.

  10. Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

    PubMed

    Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

    2010-10-01

    Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies.

  11. High amplitude of R waves in electrocardiograms, and overload related to heaviness of work in the population of maritime workers.

    PubMed

    Waśkiewicz, J

    1998-01-01

    In the compass of 20 years 4705 electrocardiograms of maritime industry workers were subjected to evaluation. The population examined consisted of: 780 seamen and deep sea fishermen, 307 merchant marine officers over 40 years of age and 260 officers under 40, 1326 harbour workers who perform light and moderately heavy physical work, 363 harbour workers employed not directly at cargo loading, and 1023 hard working stevedores. The study group was sampled at random. 526 cases of left ventricle hypertrophy were revealed, including: LVH /p/ type--348, LVH /e/--82, LVH /m/--66, and LVH /s/--30 cases. Arterial hypertension according WHO standards was diagnosed in 334 people. 38 people with arterial hypertension showed LVH with ST-T disorders. The highest proportion of LVH /p/ and ecg with traits of vagotony were found in the stevedores performing heavy and very heavy work. In the group of seamen and deep sea fishermen LVH /p/ hypertrophy was manifest in 2.3%, all LVH cases totally in 5.9%, and traits of vagotony in 10.0% of subjects. All the LVH cases with ST-T changes in the study material were associated with the arterial hypertension and few cases with other pathology. Features of LVH /p/ in the groups examined as well as in the individual evaluation were connected with a high level of physical activity. PMID:10431649

  12. Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

    PubMed

    Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

    2010-10-01

    Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies. PMID:20674066

  13. Robust sleep apnea monitoring using heart rate variability and extended Kalman classification based on single lead ECG.

    PubMed

    Asadpour, Vahid; Fazel-Rezai, Reza; Alibakhshian, Elahe

    2013-01-01

    Sleep apnea diagnosis requires analysis of long term polysomnographic signal during one period of night sleep. Limited access to sleep laboratories, various required devices and dedicated assistants made the diagnosis of sleep apnea underestimated and not easily accessible to the general population. In this work, a classification method based on modified Kalman filter which uses heart rate variability (HRV) wavelet signal obtained from a single electrocardiogram (ECG) lead is proposed. A pre-filtering was performed on wavelet transform to improve the correlation of extracted features. Sample entropy was used to enhance the convergence rate and accuracy of classification. The performance of the proposed method was evaluated in terms of accuracy, sensitivity and specificity. The classifier overcomes these methods by 5.3% to 7.2% improvements in accuracy.

  14. Time based measurement of the impedance of the skin-electrode interface for dry electrode ECG recording.

    PubMed

    Dozio, Roberta; Baba, Adeshina; Assambo, Cedric; Burke, Martin J

    2007-01-01

    This paper reports the measurement of the properties of dry or pasteless conductive electrodes to be used for long-term recording of the human electrocardiogram (ECG). Knowledge of these properties is essential for the correct design of the input stage of associated recording amplifiers. Measurements were made on three commercially available conductive carbon based electrodes at pressures of 5 mmHg and 20 mmHg, located on the lower abdomen of the body on three subjects having different skin types. Parameter values were fitted to a two-time-constant based model of the electrode using data measured over a period of 10s. Values of resistance, ranging from 40kOmega to 1590kOmega and of capacitance ranging from 0.05 microF to 38 microF were obtained for the components, while the values of the time-constants varied from 0.07 s to 3.9s.

  15. An unusual ECG pattern in restrictive cardimyopathy

    PubMed Central

    Selvaganesh, M.; Arul, A.S.; Balasubramanian, S.; Ganesan, N.; Naina Mohammed, S.; Sivakumar, G.S.; Veeramani, S.R.; Jeyasingh, P.; Sathishkumar, S.; Selvaraju, S.

    2015-01-01

    Restrictive cardiomyopathy is the least common type of primary cardiomyopathies. Electrocardiographic recording is abnormal in 99% of patients with RCM. Biatrial enlargement, obliquely elevated ST segment with notched or biphasic late peaking T waves are considered characteristic ECG finding. Significant ST depression with T inversion mimicking subendocardial ischemia has also been reported in patients with RCM and is even suggested as a predictor of sudden cardiac death. We noted a similar ECG pattern in a 16 yr girl with Idiopathic restrictive cardiomyopathy. Coronaries were normal, stress perfusion imaging did not show any perfusion defect. This diffuse resting ST depression with T inversion in precordial & inferior leads along with ST elevation in aVR was persistent for more than six months. PMID:26304570

  16. Single frequency RF powered ECG telemetry system

    NASA Technical Reports Server (NTRS)

    Ko, W. H.; Hynecek, J.; Homa, J.

    1979-01-01

    It has been demonstrated that a radio frequency magnetic field can be used to power implanted electronic circuitry for short range telemetry to replace batteries. A substantial reduction in implanted volume can be achieved by using only one RF tank circuit for receiving the RF power and transmitting the telemetered information. A single channel telemetry system of this type, using time sharing techniques, was developed and employed to transmit the ECG signal from Rhesus monkeys in primate chairs. The signal from the implant is received during the period when the RF powering radiation is interrupted. The ECG signal is carried by 20-microsec pulse position modulated pulses, referred to the trailing edge of the RF powering pulse. Satisfactory results have been obtained with this single frequency system. The concept and the design presented may be useful for short-range long-term implant telemetry systems.

  17. An unusual ECG pattern in restrictive cardimyopathy.

    PubMed

    Selvaganesh, M; Arul, A S; Balasubramanian, S; Ganesan, N; Naina Mohammed, S; Sivakumar, G S; Veeramani, S R; Jeyasingh, P; Sathishkumar, S; Selvaraju, S

    2015-01-01

    Restrictive cardiomyopathy is the least common type of primary cardiomyopathies. Electrocardiographic recording is abnormal in 99% of patients with RCM. Biatrial enlargement, obliquely elevated ST segment with notched or biphasic late peaking T waves are considered characteristic ECG finding. Significant ST depression with T inversion mimicking subendocardial ischemia has also been reported in patients with RCM and is even suggested as a predictor of sudden cardiac death. We noted a similar ECG pattern in a 16 yr girl with Idiopathic restrictive cardiomyopathy. Coronaries were normal, stress perfusion imaging did not show any perfusion defect. This diffuse resting ST depression with T inversion in precordial & inferior leads along with ST elevation in aVR was persistent for more than six months. PMID:26304570

  18. The patient's motivation during bicycle stress ECG test is dependent on the investigator's sex in male patients.

    PubMed

    Jung, Christian; Ferrari, Markus; Goebel, Bjoern; Figulla, Hans R

    2009-08-21

    The exercise electrocardiogram is a commonly used non-invasive method for detection of electrocardiogram (ECG) changes secondary to myocardial ischemia. Studies showed the importance of the patient's motivation to reach the estimated submaximal heart rate. The purpose of this study was to test whether the patient's motivation is dependent on the investigator's sex. We included 1170 patients (in-hospital patients and out-clinic patients; 63.5% male, 36.5% female) in this study. Stress test data (stationary bicycle with gradually increasing intensity) were collected retrospectively: patient's age, sex, maximal power stage, ECG-abnormalities, angina pectoris, and attending physician's sex. Male patients achieved a higher power stage than their female counterparts (126.5+/-47.7 W vs. 89.7+/-30.4 W). When male patients were supervised by a female doctor they reached higher maximum power stages (136.6+/-53.5 W vs. 121.6+/-43.3 W; p=0,001), more often the submaximal heart rate (47.9% vs. 38.3%; p=0.02) but complained less frequent about angina pectoris (5.6% vs. 17.3%). In contrast, none of these parameters was dependent on the attending physician's sex in female patients. The attending physician's sex influences the maximum exercise ability and the incidence of complaints during bicycle stress in male patients but not in females. We would speculate that men try to impress women with physical strength and try to dissimulate physical discomfort or pain. This could possibly influence the validity of such non-invasive methods with exercise dependent detection of myocardial ischemia.

  19. Electrocardiogram of Clinically Healthy Mithun (Bos frontalis): Variation among Strains.

    PubMed

    Sanyal, Sagar; Das, Pradip Kumar; Ghosh, Probal Ranjan; Das, Kinsuk; Vupru, Kezha V; Rajkhowa, Chandan; Mondal, Mohan

    2010-09-22

    A study was conducted to establish the normal electrocardiogram in four different genetic strains of mithun (Bos frontalis). Electrocardiography, cardiac electrical axis, heart rate, rectal temperature and respiration rate were recorded in a total of 32 adult male mithun of four strains (n = 8 each). It was found that the respiration and heart rates were higher (P < .05) in Manipur than other three strains. Amplitude (P < .05) and duration of P wave and QRS complex differed (P < .01) among the strains. Mizoram strain had the highest amplitude and duration of P wave and QRS complex. On the other hand, higher (P < .05) amplitude and duration of T wave were recorded in Arunachalee and Mizoram strains. The mean electrical axis of QRS complex that were recorded for Arunachalee and Manipur strains were similar to that reported for other bovine species; whereas the electrical axis of QRS for Nagamese and Mizoram strains were more close to feline and caprine species, respectively. In conclusion, electrocardiogram of mithun revealed that the amplitude and duration of P wave, QRS complex and T wave were different among four different genetic strains of mithun and the electrical axis of QRS complex for Nagamese and Mizoram mithuns are dissimilar to bovine species.

  20. The normal electrocardiogram of conscious golden eagles (Aquila chrysaetos).

    PubMed

    Hassanpour, Hossein; Moghaddam, Abdol Karim Zamani; Bashi, Mehdi Cheraghchi

    2010-09-01

    The aim of this study was to describe the normal electrocardiographic patterns and values in conscious golden eagles (Aquila chrysaetos). The standard bipolar and augmented unipolar limb leads' electrocardiograms were recorded in the golden eagles. The waveforms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine P, PR (segment and interval), QRS, ST, and QT durations and P, net QRS complex, and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis for the frontal plane was calculated using standard bipolar leads II and III. The mean heart rate was 346.7 +/- 14.29 beats/min. The P wave was predominantly positive in standard bipolar leads I and II and augmented unipolar limb leads aVL and aVF. The dominant pattern ofwaveforms of the QRS complexes were QS in leads I, II, III, and aVF, whereas in leads aVR and aVL, the pattern was always R. The T wave was slightly positive in leads I, II, and aVF. The average value of the heart mean electrical axis was -85.9 +/- 7.50 degrees. Establishment of normal electrocardiogram values will facilitate a better understanding of electrocardiographic changes seen in many avian diseases. PMID:20945639