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Sample records for 12-lead surface ecg

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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…

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  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. 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

  15. 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

  16. 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

  17. 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.

  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. 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.

  20. 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.

  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. 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.

  3. 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.

  4. 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.

  5. 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

  6. ECG Artifact Removal from Surface EMG Signal Using an Automated Method Based on Wavelet-ICA.

    PubMed

    Abbaspour, Sara; Lindén, Maria; Gholamhosseini, Hamid

    2015-01-01

    This study aims at proposing an efficient method for automated electrocardiography (ECG) artifact removal from surface electromyography (EMG) signals recorded from upper trunk muscles. Wavelet transform is applied to the simulated data set of corrupted surface EMG signals to create multidimensional signal. Afterward, independent component analysis (ICA) is used to separate ECG artifact components from the original EMG signal. Components that correspond to the ECG artifact are then identified by an automated detection algorithm and are subsequently removed using a conventional high pass filter. Finally, the results of the proposed method are compared with wavelet transform, ICA, adaptive filter and empirical mode decomposition-ICA methods. The automated artifact removal method proposed in this study successfully removes the ECG artifacts from EMG signals with a signal to noise ratio value of 9.38 while keeping the distortion of original EMG to a minimum. PMID:25980853

  7. 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.

  8. 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%.

  9. Segmentation of ECG from Surface EMG Using DWT and EMD: A Comparison Study

    NASA Astrophysics Data System (ADS)

    Shahbakhti, Mohammad; Heydari, Elnaz; Luu, Gia Thien

    2014-10-01

    The electrocardiographic (ECG) signal is a major artifact during recording the surface electromyography (SEMG). Removal of this artifact is one of the important tasks before SEMG analysis for biomedical goals. In this paper, the application of discrete wavelet transform (DWT) and empirical mode decomposition (EMD) for elimination of ECG artifact from SEMG is investigated. The focus of this research is to reach the optimized number of decomposed levels using mean power frequency (MPF) by both techniques. In order to implement the proposed methods, ten simulated and three real ECG contaminated SEMG signals have been tested. Signal-to-noise ratio (SNR) and mean square error (MSE) between the filtered and the pure signals are applied as the performance indexes of this research. The obtained results suggest both techniques could remove ECG artifact from SEMG signals fair enough, however, DWT performs much better and faster in real data.

  10. 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

  11. 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.

  12. 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.

  13. [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.

  14. 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.

  15. Arm and wrist surface potential mapping for wearable ECG rhythm recording devices: a pilot clinical study

    NASA Astrophysics Data System (ADS)

    Lynn, W. D.; Escalona, O. J.; McEneaney, D. J.

    2013-06-01

    This study addresses an important question in the development of a ECG device that enables long term monitoring of cardiac rhythm. This device would utilise edge sensor technologies for dry, non-irritant skin contact suitable for distal limb application and would be supported by embedded ECG denoising processes. Contemporary ECG databases including those provided by MIT-BIH and Physionet are focused on interpretation of cardiac disease and rhythm tracking. The data is recorded using chest leads as in standard clinical practise. For the development of a peripherally located heart rhythm monitor, such data would be of limited use. To provide a useful database adequate for the development of the above mentioned cardiac monitoring device a unipolar body surface potential map from the left arm and wrist was gathered in 37 volunteer patients and characterized in this study. For this, the reference electrode was placed at the wrist. Bipolar far-field electrogram leads were derived and analysed. Factors such as skin variability, 50Hz noise interference, electrode contact noise, motion artifacts and electromyographic noise, presented a challenge. The objective was quantify the signal-to-noise ratio (SNR) at the far-field locations. Preliminary results reveal that an electrogram indicative of the QRS complex can be recorded on the distal portion of the left arm when denoised using signal averaging techniques.

  16. Adaptive filtering of ECG interference on surface EEnGs based on signal averaging.

    PubMed

    Garcia-Casado, Javier; Martinez-de-Juan, Jose L; Ponce, Jose L

    2006-06-01

    An external electroenterogram (EEnG) is the recording of the small bowel myoelectrical signal using contact electrodes placed on the abdominal surface. It is a weak signal affected by possible movements and by the interferences of respiration and, principally, of the cardiac signal. In this paper an adaptive filtering technique was proposed to identify and subsequently cancel ECG interference on canine surface EEnGs by means of a signal averaging process time-locked with the R-wave. Twelve recording sessions were carried out on six conscious dogs in the fasting state. The adaptive filtering technique used increases the signal-to-interference ratio of the raw surface EEnG from 16.7 +/- 6.5 dB up to 31.9 +/- 4.0 dB. In addition to removing ECG interference, this technique has been proven to respect intestinal SB activity, i.e. the EEnG component associated with bowel contractions, despite the fact that they overlap in the frequency domain. In this way, more robust non-invasive intestinal motility indicators can be obtained with correlation coefficients of 0.68 +/- 0.09 with internal intestinal activity. The method proposed here may also be applied to other biological recordings affected by cardiac interference and could be a very helpful tool for future applications of non-invasive recordings of gastrointestinal signals.

  17. 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

  18. 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

  19. 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.

  20. ECG body surface mapping in patients with gestational diabetes mellitus and optimal metabolic compensation.

    PubMed

    Žákovičová, E; Kittnar, O; Slavíček, J; Medová, E; Šváb, P; Charvát, J

    2014-01-01

    Women with gestational diabetes mellitus (GDM) are at increased risk for cardiovascular diseases (CVD) events compared with women without GDM. The aim of the present study was to evaluate 200 parameters of the heart electric field in 35 women with GDM under optimal glycemic compensation compared to 32 healthy pregnant women. All examinations were performed in the 36th week of gestation. The parameters in ECG body surface mapping (BSM) were registered by the diagnostic system Cardiag 112.2. The absolute values of maximum and minimum in depolarization and repolarization isopotential, isointegral and isoarea maps were not significantly different between the groups. These findings correspond to the result of heart rate variability examination. However BSM revealed the significant prolongation of QRS complex (p=0.05), shortening of ventricular myocardial activation time (ICHVAT) (p=0.01), prolongation of mean QT duration (p=0.01) and increase of QT interval dispersion (p=0.01) in women with GDM. Duration of QRS and ICHVAT significantly correlated with interventricular septum and posterior wall thickness in GDM group, QTd interval correlated significantly with HbA1C level. We conclude that despite of optimal metabolic control several significant abnormalities detected by ECG BSM are still present in patients with GDM. PMID:25669679

  1. Time-frequency characterization of atrial fibrillation from surface ECG based on Hilbert-Huang transform.

    PubMed

    Huang, Z; Chen, Y; Pan, M

    2007-01-01

    In this paper, based on Hilbert-Huang transform (HHT), we develop a new non-invasive time-frequency analysis method to characterize the dynamic behaviour of atrial fibrillation (AF) from surface ECG. We first extract f waves from single-lead ECG records of AF patients using PCA analysis. To capture the non-stationary behaviours of AF signals at different time scales, we use HHT to find the Hilbert spectrum and instantaneous frequency (IF) distribution of residual signals from principal component analysis. Two important feature variables, namely mean IF (mIF) and index of frequency stability over time (IS), are derived from the IF distribution, and in combination will be able to effectively discriminate two different AF types: self-terminating and non-terminating termination. The proposed AF signal decomposition and analysis method will help us efficiently differentiate individual AF patients, advance our understanding of AF mechanisms, and provide useful guidelines for improving administration of AF patients, especially paroxysmal AF.

  2. 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

  3. 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

  4. Effective extraction of diagnostic ECG waveform information using orthonormal basis functions derived from body surface potential maps.

    PubMed

    Kornreich, F; Rautaharju, P M; Warren, J W; Horacek, B M; Dramaix, M

    1985-10-01

    A common basis of orthogonal waveform functions was derived from 128 lead body surface potential maps of 405 subjects. Twelve such orthogonal functions or frames were adequate for reconstruction of original ECGs from the beginning of QRS to the end of T. A larger number of frames (18) was required when basis functions were derived separately for QRS (10) and ST-T segments (8). Diagnostic information content of the coefficients of the orthogonal basis functions was evaluated in comparison with Minnesota Code criteria for myocardial infarction and with a more advanced multivariate ECG analysis program (Pipberger Program). This was done by deriving a linear discriminant function for separating normals from ECGs of patients with myocardial infarction and testing the discriminant in a different test population of infarcts and normals. The diagnostic accuracy of orthogonal basis functions was as good as that of Pipberger's program and considerably better than that of the Minnesota Code. The classification method described is insensitive to noise and errors in detecting QRS and T wave onsets and offsets or in selecting proper baseline for amplitude measurements. The robustness and enhanced classification stability with respect to noise and minor wave detection errors is a potential advantage particularly in serial ECG comparison.

  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. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. [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.

  17. 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.

  18. 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

  19. 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

  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

    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.

  1. High-frequency ECG

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.

    2006-01-01

    ventricular surface and were signal-averaged and filtered in the 30-250 Hz frequency range. The results showed that the decrease noted in the HF-QRS correlated linearly with the local conduction delay. The results suggest that HF-QRS is a potent indicator of disturbed local conduction. An alternative theory is that HF-QRS reflect the shape of the original electrocardiographic signal. Bennhagen et al showed that root mean square (RMS) voltage values of the depolarization signal correlate poorly with the signal amplitude but highly with the first and second derivatives, i.e. the velocity and the acceleration of the signal. It has also been suggested that the autonomic nervous system affects HF-QRS. For example, sitting up causes significant changes in HF-QRS in some leads compared to the supine position [Douglas et al., 2006]. Unpublished results indicate that familial dysautonomic patients (both vagal and sympathetic degeneration) have very little Reduced Amplitude Zones (RAZ) formation . Athletic individuals, especially elite athletes, who have vagally-mediated changes on the conventional ECG (i.e. early repolarization, bradycardia) have increased RAZ formation. Further electrophysiological studies are needed, however, to better understand the underlying mechanisms of HF-QRS. Several investigators have studied HF-QRS in different cardiac conditions, including acute myocardial ischemia and myocardial infarction (MI). However, in order for clinicians to confidently use HF-QRS as an adjunct to standard ECG, more knowledge about the characteristics of HF-QRS is needed.

  2. 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

  3. 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

  4. Preoperative study of the surface ECG for the prognosis of atrial fibrillation maze surgery outcome at discharge.

    PubMed

    Hernández, Antonio; Alcaraz, Raúl; Hornero, Fernando; Rieta, José Joaquín

    2014-07-01

    The Cox-maze surgery is an effective procedure for terminating atrial fibrillation (AF) in patients requiring open-heart surgery associated with another heart disease. After the intervention, regardless of the patient's rhythm, all are treated with oral anticoagulants and antiarrhythmic drugs prior to discharge. Furthermore, patients maintaining AF before discharge could also be treated with electrical cardioversion (ECV). In view of this, a preoperative prognosis of the patient's rhythm at discharge would be helpful for optimizing drug therapy planning as well as for advancing ECV therapy. This work analyzes 30 preoperative electrocardiograms (ECGs) from patients suffering from AF in order to predict the Cox-maze surgery outcome at discharge. Two different characteristics of the AF pattern have been studied. On the one hand, the atrial activity (AA) organization, which provides information about the number of propagating wavelets in the atria, was investigated. AA organization has been successfully used in previous studies related to spontaneous reversion of paroxysmal AF and to the outcome of ECV. To assess organization, the dominant atrial frequency (DAF) and sample entropy (SampEn) have been computed. On the other hand, the second characteristic studied was the fibrillatory wave (f-wave) amplitude, which has been demonstrated to be a valuable indicator of the Cox-maze surgery outcome in previous studies. Moreover, this parameter has been obtained through a new methodology, based on computing the f-wave average power (fWP). Finally, all the computed indices were combined in a decision tree in order to improve prediction capability. Results for the DAF yielded a sensitivity (Se), a specificity (Sp) and an accuracy (Acc) of 61.54%, 82.35% and 73.33%, respectively. For SampEn the values were 69.23%, 76.00% and 73.33%, respectively, and for fWP they were 92.31%, 82.35% and 86.67%, respectively. Finally, the decision tree combining the three parameters analyzed

  5. 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.

  6. 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

  7. 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.

  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. 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. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  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. 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).

  2. 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

  3. 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

  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.

  5. 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

  6. 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.

  7. Antiequine chorionic gonadotropin (eCG) antibodies generated in goats treated with eCG for the induction of ovulation modulate the luteinizing hormone and follicle-stimulating hormone bioactivities of eCG differently.

    PubMed

    Hervé, Virginie; Roy, François; Bertin, Jean; Guillou, Florian; Maurel, Marie-Christine

    2004-01-01

    In dairy goats, treatments associating a progestogen and the equine chorionic gonadotropin (eCG) are the easiest way to induce and synchronize estrus and ovulation and to permit artificial insemination (AI) and/or out of season breeding. From the first treatment, the injection of eCG induces, in some females, the production of anti-eCG antibodies (Abs) that will interfere with the effectiveness of subsequent treatments. These anti-eCG Abs delay the preovulatory LH surge and the ovulation time, leading to poor fertility of the treated females. In this study, by in vitro bioassays, we show that anti-eCG Abs can positively or negatively modulate the LH and/or FSH bioactivities of eCG. Moreover, the modulation level of eCG bioactivity does not depend on the anti-eCG Ab affinity for eCG, as shown by surface plasmon resonance technology. The specificity of anti-eCG Abs tested by competitive ELISA highlighted the importance of a glycan environment in the recognition mechanism, especially the sialic acids specific to eCG. The different effects of anti-eCG Abs on eCG bioactivities could be explained by two hypotheses. First, steric hindrance preventing the interaction of eCG with its receptors would explain the inhibitory effect of some anti-eCG Abs; second, a conformational change in eCG by anti-eCG Abs could induce inhibition or potentiation of eCG bioactivities. It is significant that these modulations of eCG bioactivities by anti-eCG Abs impact mainly on the FSH bioactivity of eCG, which is essential for ovarian stimulation and subsequent fertility after treatment and AI, and to a lesser extent on LH bioactivity.

  8. [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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Development of a portable wireless system for bipolar concentric ECG recording

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    Cardiovascular diseases (CVDs) remain the biggest cause of deaths worldwide. ECG monitoring is a key tool for early diagnosis of CVDs. Conventional monitors use monopolar electrodes resulting in poor spatial resolution surface recordings and requiring extensive wiring. High-spatial resolution surface electrocardiographic recordings provide valuable information for the diagnosis of a wide range of cardiac abnormalities, including infarction and arrhythmia. The aim of this work was to develop and test a wireless recording system for acquiring high spatial resolution ECG signals, based on a flexible tripolar concentric electrode (TCE) without cable wiring or external reference electrode which would make more comnfortable its use in clinical practice. For this, a portable, wireless sensor node for analogue conditioning, digitalization and transmission of a bipolar concentric ECG signal (BC-ECG) using a TCE and a Mason-likar Lead-I ECG (ML-Lead-I ECG) signal was developed. Experimental results from a total of 32 healthy volunteers showed that the ECG fiducial points in the BC-ECG signals, recorded with external and internal reference electrode, are consistent with those of simultaneous ML-Lead-I ECG. No statistically significant difference was found in either signal amplitude or morphology, regardless of the reference electrode used, being the signal-to-noise similar to that of ML-Lead-I ECG. Furthermore, it has been observed that BC-ECG signals contain information that could not available in conventional records, specially related to atria activity. The proposed wireless sensor node provides non-invasive high-local resolution ECG signals using only a TCE without additional wiring, which would have great potential in medical diagnosis of diseases such as atrial or ventricular fibrillations or arrhythmias that currently require invasive diagnostic procedures (catheterization).

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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…

  2. 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.

  3. ST-segment changes in high-resolution body surface potential maps measured during exercise to assess myocardial ischemia: a pilot study

    PubMed Central

    Zaczek, Rajmund; Zavala-Fernandez, Heriberto; Janusek, Dariusz; Kobylecka, Małgorzata; Królicki, Leszek; Opolski, Grzegorz; Maniewski, Roman

    2014-01-01

    Introduction The aim of the study was to assess myocardial ischemia by analysis of ST-segment changes in high-resolution body surface potential maps (HR-BSPM) measured at rest and during an exercise stress test. Material and methods The study was carried out on a group of 28 patients with stable coronary artery disease and 15 healthy volunteers. The HR-BSPM were measured at rest and during the exercise stress test on a supine ergometer. The workload was increased in stages by 25 W every 2 min, beginning at 50 W. The maps of ST-segment depression (ST60) were calculated from time averaged recordings at rest and at maximal workload. Results The efficiency in detection of myocardial ischemia was higher for HR-BSPM than for standard 12-lead electrocardiography (ECG) when both methods were evaluated by outcomes of coronarography. The sensitivity of HR-BSPM was 82.4% while for the standard 12-lead ECG exercise stress test it was 58.8%. For some patients significant changes in the ST segment were observed at stress HR-BSPM but were not visible in standard 12-lead ECG recorded under the same conditions. Conclusions Obtained high values of sensitivity and specificity in myocardial ischemia detection suggest that maps of ST60 calculated from HR-BSPM can improve detection of patients with ischemic heart disease in comparison to the standard electrocardiographic exercise stress test examinations. PMID:25624843

  4. 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

  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. XML-BSPM: an XML format for storing Body Surface Potential Map recordings

    PubMed Central

    2010-01-01

    Background The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. Methods The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. Results This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. Conclusions This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual

  7. 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

  8. 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.

  9. [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.

  10. 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.

  11. 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

  12. Mouse ECG findings in aging, with conduction system affecting drugs and in cardiac pathologies: Development and validation of ECG analysis algorithm in mice.

    PubMed

    Merentie, Mari; Lipponen, Jukka A; Hedman, Marja; Hedman, Antti; Hartikainen, Juha; Huusko, Jenni; Lottonen-Raikaslehto, Line; Parviainen, Viktor; Laidinen, Svetlana; Karjalainen, Pasi A; Ylä-Herttuala, Seppo

    2015-12-01

    Mouse models are extremely important in studying cardiac pathologies and related electrophysiology, but very few mouse ECG analysis programs are readily available. Therefore, a mouse ECG analysis algorithm was developed and validated. Surface ECG (lead II) was acquired during transthoracic echocardiography from C57Bl/6J mice under isoflurane anesthesia. The effect of aging was studied in young (2-3 months), middle-aged (14 months) and old (20-24 months) mice. The ECG changes associated with pharmacological interventions and common cardiac pathologies, that is, acute myocardial infarction (AMI) and progressive left ventricular hypertrophy (LVH), were studied. The ECG raw data were analyzed with an in-house ECG analysis program, modified specially for mouse ECG. Aging led to increases in P-wave duration, atrioventricular conduction time (PQ interval), and intraventricular conduction time (QRS complex width), while the R-wave amplitude decreased. In addition, the prevalence of arrhythmias increased during aging. Anticholinergic atropine shortened PQ time, and beta blocker metoprolol and calcium-channel blocker verapamil increased PQ interval and decreased heart rate. The ECG changes after AMI included early JT elevation, development of Q waves, decreased R-wave amplitude, and later changes in JT/T segment. In progressive LVH model, QRS complex width was increased at 2 and especially 4 weeks timepoint, and also repolarization abnormalities were seen. Aging, drugs, AMI, and LVH led to similar ECG changes in mice as seen in humans, which could be reliably detected with this new algorithm. The developed method will be very useful for studies on cardiovascular diseases in mice.

  13. A Study on the Optimal Positions of ECG Electrodes in a Garment for the Design of ECG-Monitoring Clothing for Male.

    PubMed

    Cho, Hakyung; Lee, Joo Hyeon

    2015-09-01

    Smart clothing is a sort of wearable device used for ubiquitous health monitoring. It provides comfort and efficiency in vital sign measurements and has been studied and developed in various types of monitoring platforms such as T-shirt and sports bra. However, despite these previous approaches, smart clothing for electrocardiography (ECG) monitoring has encountered a serious shortcoming relevant to motion artifacts caused by wearer movement. In effect, motion artifacts are one of the major problems in practical implementation of most wearable health-monitoring devices. In the ECG measurements collected by a garment, motion artifacts are usually caused by improper location of the electrode, leading to lack of contact between the electrode and skin with body motion. The aim of this study was to suggest a design for ECG-monitoring clothing contributing to reduction of motion artifacts. Based on the clothing science theory, it was assumed in this study that the stability of the electrode in a dynamic state differed depending on the electrode location in an ECG-monitoring garment. Founded on this assumption, effects of 56 electrode positions were determined by sectioning the surface of the garment into grids with 6 cm intervals in the front and back of the bodice. In order to determine the optimal locations of the ECG electrodes from the 56 positions, ECG measurements were collected from 10 participants at every electrode position in the garment while the wearer was in motion. The electrode locations indicating both an ECG measurement rate higher than 80.0 % and a large amplitude during motion were selected as the optimal electrode locations. The results of this analysis show four electrode locations with consistently higher ECG measurement rates and larger amplitudes amongst the 56 locations. These four locations were abstracted to be least affected by wearer movement in this research. Based on this result, a design of the garment-formed ECG monitoring platform

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. The feasibility of bench tests for disposable ECG electrode adhesiveness.

    PubMed

    Baker, C D; Schoenberg, A A; Booth, H E

    1979-01-01

    The feasibility of recommending one standard bench test that adequately qualifies electrode adhesives for clinical use was examined by UBTL. Small strips, cut from whole, commercially available disposable ECG electrodes, were attached to three types of surfaces, and samples of each type of electrode were peel tested at 15 minutes, 8 hours, and 48 hours after attachment. A program was developed to average, display, and calculate peel strength parameters. Analysis of the data showed that (a) the peel strength of electrodes varied by more than a factor of 10 when measured on human skin, and by more than a factor of 3 when measured on bench test surfaces, and (b) the peel strength of the electrode adhesive strips did not correlate with intact electrode loss on ambulatory subjects. Therefore, UBTL could not recommend one bench test that would measure adhesion performance for all electrode types appropriate for inclusion in an AAMI ECG electrode standard.

  1. 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

  2. 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.

  3. 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.

  4. [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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. [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

  15. 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.

  16. 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.

  17. On the resolution of ECG acquisition systems for the reliable analysis of the P-wave.

    PubMed

    Censi, Federica; Calcagnini, Giovanni; Corazza, Ivan; Mattei, Eugenio; Triventi, Michele; Bartolini, Pietro; Boriani, Giuseppe

    2012-02-01

    The analysis of the P-wave on surface ECG is widely used to assess the risk of atrial arrhythmias. In order to provide reliable results, the automatic analysis of the P-wave must be precise and reliable and must take into account technical aspects, one of those being the resolution of the acquisition system. The aim of this note is to investigate the effects of the amplitude resolution of ECG acquisition systems on the P-wave analysis. Starting from ECG recorded by an acquisition system with a less significant bit (LSB) of 31 nV (24 bit on an input range of 524 mVpp), we reproduced an ECG signal as acquired by systems with lower resolution (16, 15, 14, 13 and 12 bit). We found that, when the LSB is of the order of 128 µV (12 bit), a single P-wave is not recognizable on ECG. However, when averaging is applied, a P-wave template can be extracted, apparently suitable for the P-wave analysis. Results obtained in terms of P-wave duration and morphology revealed that the analysis of ECG at lowest resolutions (from 12 to 14 bit, LSB higher than 30 µV) could lead to misleading results. However, the resolution used nowadays in modern electrocardiographs (15 and 16 bit, LSB <10 µV) is sufficient for the reliable analysis of the P-wave.

  18. Investigations of sensitivity and resolution of ECG and MCG in a realistically shaped thorax model

    NASA Astrophysics Data System (ADS)

    Mäntynen, Ville; Konttila, Teijo; Stenroos, Matti

    2014-12-01

    Solving the inverse problem of electrocardiography (ECG) and magnetocardiography (MCG) is often referred to as cardiac source imaging. Spatial properties of ECG and MCG as imaging systems are, however, not well known. In this modelling study, we investigate the sensitivity and point-spread function (PSF) of ECG, MCG, and combined ECG+MCG as a function of source position and orientation, globally around the ventricles: signal topographies are modelled using a realistically-shaped volume conductor model, and the inverse problem is solved using a distributed source model and linear source estimation with minimal use of prior information. The results show that the sensitivity depends not only on the modality but also on the location and orientation of the source and that the sensitivity distribution is clearly reflected in the PSF. MCG can better characterize tangential anterior sources (with respect to the heart surface), while ECG excels with normally-oriented and posterior sources. Compared to either modality used alone, the sensitivity of combined ECG+MCG is less dependent on source orientation per source location, leading to better source estimates. Thus, for maximal sensitivity and optimal source estimation, the electric and magnetic measurements should be combined.

  19. Investigations of sensitivity and resolution of ECG and MCG in a realistically shaped thorax model.

    PubMed

    Mäntynen, Ville; Konttila, Teijo; Stenroos, Matti

    2014-12-01

    Solving the inverse problem of electrocardiography (ECG) and magnetocardiography (MCG) is often referred to as cardiac source imaging. Spatial properties of ECG and MCG as imaging systems are, however, not well known. In this modelling study, we investigate the sensitivity and point-spread function (PSF) of ECG, MCG, and combined ECG+MCG as a function of source position and orientation, globally around the ventricles: signal topographies are modelled using a realistically-shaped volume conductor model, and the inverse problem is solved using a distributed source model and linear source estimation with minimal use of prior information. The results show that the sensitivity depends not only on the modality but also on the location and orientation of the source and that the sensitivity distribution is clearly reflected in the PSF. MCG can better characterize tangential anterior sources (with respect to the heart surface), while ECG excels with normally-oriented and posterior sources. Compared to either modality used alone, the sensitivity of combined ECG+MCG is less dependent on source orientation per source location, leading to better source estimates. Thus, for maximal sensitivity and optimal source estimation, the electric and magnetic measurements should be combined.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. [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.

  12. [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

  13. 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.

  14. 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.

  15. 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...

  16. 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...

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. [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

  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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. The evolution of ambulatory ECG monitoring.

    PubMed

    Kennedy, Harold L

    2013-01-01

    Ambulatory Holter electrocardiographic (ECG) monitoring has undergone continuous technological evolution since its invention and development in the 1950s era. With commercial introduction in 1963, there has been an evolution of Holter recorders from 1 channel to 12 channel recorders with increasingly smaller storage media, and there has evolved Holter analysis systems employing increasingly technologically advanced electronics providing a myriad of data displays. This evolution of smaller physical instruments with increasing technological capacity has characterized the development of electronics over the past 50 years. Currently the technology has been focused upon the conventional continuous 24 to 48 hour ambulatory ECG examination, and conventional extended ambulatory monitoring strategies for infrequent to rare arrhythmic events. However, the emergence of the Internet, Wi-Fi, cellular networks, and broad-band transmission has positioned these modalities at the doorway of the digital world. This has led to an adoption of more cost-effective strategies to these conventional methods of performing the examination. As a result, the emergence of the mobile smartphone coupled with this digital capacity is leading to the recent development of Holter smartphone applications. The potential of point-of-care applications utilizing the Holter smartphone and a vast array of new non-invasive sensors is evident in the not too distant future. The Holter smartphone is anticipated to contribute significantly in the future to the field of global health. PMID:24215744

  18. Multiprocessor system for Holter tape analysis (ECG)

    SciTech Connect

    Feldman, C.L.; Hubelbank, M.; Valvo, V.; Lane, B.

    1983-01-01

    Although techniques for recording and analyzing longterm ambulatory ECGS have been in existence for more than 20 years, the clinical usefulness and frequency of application of the technique continue to grow at an extraordinary rate. To meet the need for faster, more efficient processing of Holter tapes and the growing requirement that the analysis of the tape be quantitatively accurate, a new Holter analysis system has been developed. This system is built around two LSI11 microprocessors and a special purpose byte processor which incorporates an AMD 2903 bit slice chip. It includes 30 MB of mass storage and an impact printer with alphanumeric and graphic capabilities. In a test which included 55 separate readings of 34 12- or 24-hour tapes, correlations with hand counts of vpbs was greater than .99. The system processes either cassette or reel-to-reel tapes at 120* with simultaneous print/process capabilities, has a variety of user interactive displays to assure continuous operator validation, is remarkably nonfatiguing to operate, and automatically produces reports with tables, graphs, and sample ECG strips. 8 references.

  19. Microprocessor Based Real-Time Monitoring of Multiple ECG Signals

    PubMed Central

    Nasipuri, M.; Basu, D.K.; Dattagupta, R.; Kundu, M.; Banerjee, S.

    1987-01-01

    A microprocessor based system capable of realtime monitoring of multiple ECG signals has been described. The system consists of a number of microprocessors connected in a hierarchical fashion and capable of working concurrently on ECG data collected from different channels. The system can monitor different arrhythmic abnormalities for at least 36 patients even for a heart rate of 500 beats/min.

  20. 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.

  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. PMID:25570031

  2. 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.

  3. Noncontact ECG system for unobtrusive long-term monitoring.

    PubMed

    McDonald, Neil J; Anumula, Harini A; Duff, Eric; Soussou, Walid

    2012-01-01

    This paper describes measurements made using an ECG system with QUASAR's capacitive bioelectrodes integrated into a pad system that is placed over a chair. QUASAR's capacitive bioelectrode has the property of measuring bioelectric potentials at a small separation from the body. This enables the measurement of ECG signals through fabric, without the removal of clothing or preparation of skin. The ECG was measured through the subject's clothing while the subject sat in the chair without any supporting action from the subject. The ECG pad system is an example of a high compliance system that places minimal requirements upon the subject and, consequently, can be used to generate a long-term record from ECG segments collected on a daily basis, providing valuable information on long-term trends in cardiac health.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Preprocessing and Analysis of Digitized ECGs

    NASA Astrophysics Data System (ADS)

    Villalpando, L. E. Piña; Kurmyshev, E.; Ramírez, S. Luna; Leal, L. Delgado

    2008-08-01

    In this work we propose a methodology and programs in MatlabTM that perform the preprocessing and analysis of the derivative D1 of ECGs. The program makes the correction to isoelectric line for each beat, calculates the average cardiac frequency and its standard deviation, generates a file of amplitude of P, Q and T waves, as well as the segments and intervals important of each beat. Software makes the normalization of beats to a standard rate of 80 beats per minute, the superposition of beats is done centering R waves, before and after normalizing the amplitude of each beat. The data and graphics provide relevant information to the doctor for diagnosis. In addition, some results are displayed similar to those presented by a Holter recording.

  9. Performance characterstics of a commerical ECG gate

    SciTech Connect

    Graham, M.; Cavailloles, F.; Ritchie, J.L.; Williams, D.L.; Hamilton, G.W.

    1980-04-01

    A commercial ECG gate was tested to evaluate its ability to predict accurately the time of end-systole. The predicted times followed the manufacturer's specifications quite well. These times were compared with the actual times of end-systole as determined by computer-derived left-ventricular time-activity curves using Tc-99m-labeled red blood cells. Although there was moderate scatter, the predicted times of end-systole correlated well with the actual time (n = 59, r = 0.829). If the left-ventricular ejection fraction was calculated using the predicted time of end-systole, the error would be 0.03, or less, for 95% of the subjects.

  10. Variable threshold method for ECG R-peak detection.

    PubMed

    Kew, Hsein-Ping; Jeong, Do-Un

    2011-10-01

    In this paper, a wearable belt-type ECG electrode worn around the chest by measuring the real-time ECG is produced in order to minimize the inconvenient in wearing. ECG signal is detected using a potential instrument system. The measured ECG signal is transmits via an ultra low power consumption wireless data communications unit to personal computer using Zigbee-compatible wireless sensor node. ECG signals carry a lot of clinical information for a cardiologist especially the R-peak detection in ECG. R-peak detection generally uses the threshold value which is fixed. There will be errors in peak detection when the baseline changes due to motion artifacts and signal size changes. Preprocessing process which includes differentiation process and Hilbert transform is used as signal preprocessing algorithm. Thereafter, variable threshold method is used to detect the R-peak which is more accurate and efficient than fixed threshold value method. R-peak detection using MIT-BIH databases and Long Term Real-Time ECG is performed in this research in order to evaluate the performance analysis.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. ECG risk markers for atrial fibrillation and sudden cardiac death in minimally symptomatic obstructive sleep apnoea: the MOSAIC randomised trial

    PubMed Central

    Schlatzer, Christian; Bratton, Daniel J; Craig, Sonja E; Kohler, Malcolm; Stradling, John R

    2016-01-01

    Objective Obstructive sleep apnoea (OSA), atrial fibrillation (AF) and sudden cardiac death (SCD) may occur concomitantly, and are of considerable epidemiological interest, potentially leading to morbidity and mortality. Effective treatment of OSA with continuous positive airway pressure (CPAP) could prevent progression and/or recurrence of AF and factors leading to SCD. Recently, a randomised controlled trial showed a statistically and clinically significant prolongation of measures of cardiac repolarisation after CPAP withdrawal in symptomatic patients with moderate to severe OSA. Whether or not CPAP therapy improves ECG risk markers of AF and SCD in patients with minimally symptomatic OSA as well, is unknown. Methods 3 centres taking part in the MOSAIC (Multicentre Obstructive Sleep Apnoea Interventional Cardiovascular) trial randomisd 303 patients with minimally symptomatic OSA to receive either CPAP or standard care for 6 months. Treatment effects of CPAP on P-wave duration, P-wave dispersion, QT interval, QT dispersion, Tpeak-to-Tend (TpTe) and TpTe/QT ratio were analysed. Results Participants were primarily men (83%). Mean age was 57.8 (7.2) and mean ODI (Oxygen Desaturation Index) at baseline was 13.1/h (12.3). Full 12-lead ECG data was available in 250 patients. Mean (SD) baseline intervals of P-wave duration, P-wave dispersion, QTc interval, QT dispersion, TpTe and TpTe/QT ratio in ms were 87.4 (8.3), 42.3 (11.9), 397.8 (22.7), 43.1 (16.7), 73.5 (13.7) and 0.19 (0.0), respectively. No treatment effect of CPAP on risk markers for AF and SCD was found. Conclusions There seems to be no effect of CPAP on ECG measures of arrhythmia risk in patients with minimally symptomatic OSA. Trial registration number ISRCTN34164388; Post-results. PMID:26983946

  17. A Differential ECG Amplifier with Single-Ended Output

    NASA Technical Reports Server (NTRS)

    Katchis, L.

    1972-01-01

    Three-stage amplifier is used for ECG measurements which require conversion of differential input to single-ended output. Circuit may be useful in biological telemetry for amplification of signals from specimen-implanted sensors.

  18. A Harmonic Linear Dynamical System for Prominent ECG Feature Extraction

    PubMed Central

    Nguyen Thi, Ngoc Anh; Yang, Hyung-Jeong; Kim, SunHee; Do, Luu Ngoc

    2014-01-01

    Unsupervised mining of electrocardiography (ECG) time series is a crucial task in biomedical applications. To have efficiency of the clustering results, the prominent features extracted from preprocessing analysis on multiple ECG time series need to be investigated. In this paper, a Harmonic Linear Dynamical System is applied to discover vital prominent features via mining the evolving hidden dynamics and correlations in ECG time series. The discovery of the comprehensible and interpretable features of the proposed feature extraction methodology effectively represents the accuracy and the reliability of clustering results. Particularly, the empirical evaluation results of the proposed method demonstrate the improved performance of clustering compared to the previous main stream feature extraction approaches for ECG time series clustering tasks. Furthermore, the experimental results on real-world datasets show scalability with linear computation time to the duration of the time series. PMID:24719648

  19. A harmonic linear dynamical system for prominent ECG feature extraction.

    PubMed

    Thi, Ngoc Anh Nguyen; Yang, Hyung-Jeong; Kim, SunHee; Do, Luu Ngoc

    2014-01-01

    Unsupervised mining of electrocardiography (ECG) time series is a crucial task in biomedical applications. To have efficiency of the clustering results, the prominent features extracted from preprocessing analysis on multiple ECG time series need to be investigated. In this paper, a Harmonic Linear Dynamical System is applied to discover vital prominent features via mining the evolving hidden dynamics and correlations in ECG time series. The discovery of the comprehensible and interpretable features of the proposed feature extraction methodology effectively represents the accuracy and the reliability of clustering results. Particularly, the empirical evaluation results of the proposed method demonstrate the improved performance of clustering compared to the previous main stream feature extraction approaches for ECG time series clustering tasks. Furthermore, the experimental results on real-world datasets show scalability with linear computation time to the duration of the time series.

  20. The segmented-beat modulation method for ECG estimation.

    PubMed

    Agostinelli, A; Giuliani, C; Fioretti, S; Di Nardo, F; Burattini, L

    2015-08-01

    Electrocardiographic (ECG) tracings corrupted by noise with frequency components in the ECG frequency band, may result useless unless appropriately processed. The estimation of the clean ECG from such recordings, however, is quite challenging; being linear filtering inappropriate. In the common situations in which the R peaks are detectable, template-based techniques have been proposed to estimate the ECG by a template-beat concatenation. However, such techniques have the major limit of not being able to reproduce physiological heart-rate and morphological variability. Thus, the aim of the present study was to propose the segmented-beat modulation method (SBMM) as the technique that overcomes such limit. The SBMM is an improved template-based technique that provides good-quality estimations of ECG tracings characterized by some heart-rate and morphological variability. It segments the template ECG beat into QRS and TUP segments and then, before concatenation, it applies a modulation/demodulation process to the TUP-segment so that the estimated-beat duration and morphology adjust to those of the corresponding original-beat. To test its performance, the SBMM was applied to 19 ECG tracings from normal subjects. There were no errors in estimating the R peak location, and the errors in the QRS and TUP segments were low (≤65 μV and ≤30 μV, respectively), with the former ones being significantly higher than the latter ones. Eventually, TUP errors tended to increase with increasing heart-rate variability (correlation coefficient: 0.59, P<;10(-2)). In conclusion, the new SBMM proved to be a useful tool for providing good-quality ECG estimations of tracings characterized by heart-rate and morphological variability.

  1. Human ECG signal parameters estimation during controlled physical activity

    NASA Astrophysics Data System (ADS)

    Maciejewski, Marcin; Surtel, Wojciech; Dzida, Grzegorz

    2015-09-01

    ECG signal parameters are commonly used indicators of human health condition. In most cases the patient should remain stationary during the examination to decrease the influence of muscle artifacts. During physical activity, the noise level increases significantly. The ECG signals were acquired during controlled physical activity on a stationary bicycle and during rest. Afterwards, the signals were processed using a method based on Pan-Tompkins algorithms to estimate their parameters and to test the method.

  2. A method for the determination of ECG gate signal delays

    SciTech Connect

    Wery, R.; Hill, J.; Dworkin, H.J.

    1981-06-01

    A simple device using a rotating radioactive source was developed to monitor the presence of a delay between the patient's R wave and the gate signal being sent to the computer. Three commercial ECG gates were tested and significant delays were found in two of them. Identical patient data evaluated using ECG gates with and without significant delays produced calculated left-ventricular ejection fractions of 0.05 and 0.64, respectively.

  3. 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.

  4. Rationale and objectives for ECG screening in infancy.

    PubMed

    Saul, J Philip; Schwartz, Peter J; Ackerman, Michael J; Triedman, John K

    2014-12-01

    Electrocardiographic (ECG) screening in infants and children who may be at risk of sudden cardiac death (SCD) is controversial, and both rational and emotional arguments have often been given equal weight. We all have direct experience in this field, but have different backgrounds and have expressed divergent views on this topic. We attempted to build consensus among ourselves on the basis of the available facts, in the hope of providing an unbiased review of the relevant science and policy issues in favor of or against ECG screening in infants and children. This report presents our shared view on this medically and societally important topic. Long QT syndrome (LQTS) satisfies several criteria that may make ECG screening worthwhile: it is not rare (~1 in 2000 births); ECG diagnosis is feasible and can be used to trigger appropriate genetic testing; it causes approximately 10% of cases of sudden infant death syndrome (SIDS) as well as deaths in childhood and later in life, and effective treatments are available. By stimulating cascade screening in family members, diagnosis of affected infants may also prompt identification of asymptomatic but affected individuals. Neonatal screening is cost-effective by conventional criteria, and with a corrected QT (QTc) cutoff of 460 ms in 2 different ECGs, the number of false positives is estimated to be low (~1 in 1000 births). It is our conclusion that parents of newborn children should be informed about LQTS, a life-threatening but treatable disease of significant prevalence that may be diagnosed by a simple ECG. PMID:25239430

  5. 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.

  6. Adaptive wavelet Wiener filtering of ECG signals.

    PubMed

    Smital, Lukáš; Vítek, Martin; Kozumplík, Jiří; Provazník, Ivo

    2013-02-01

    In this study, we focused on the reduction of broadband myopotentials (EMG) in ECG signals using the wavelet Wiener filtering with noise-free signal estimation. We used the dyadic stationary wavelet transform (SWT) in the Wiener filter as well as in estimating the noise-free signal. Our goal was to find a suitable filter bank and to choose other parameters of the Wiener filter with respect to the signal-to-noise ratio (SNR) obtained. Testing was performed on artificially noised signals from the standard CSE database sampled at 500 Hz. When creating an artificial interference, we started from the generated white Gaussian noise, whose power spectrum was modified according to a model of the power spectrum of an EMG signal. To improve the filtering performance, we used adaptive setting parameters of filtering according to the level of interference in the input signal. We were able to increase the average SNR of the whole test database by about 10.6 dB. The proposed algorithm provides better results than the classic wavelet Wiener filter.

  7. 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.

  8. Adaptive wavelet Wiener filtering of ECG signals.

    PubMed

    Smital, Lukáš; Vítek, Martin; Kozumplík, Jiří; Provazník, Ivo

    2013-02-01

    In this study, we focused on the reduction of broadband myopotentials (EMG) in ECG signals using the wavelet Wiener filtering with noise-free signal estimation. We used the dyadic stationary wavelet transform (SWT) in the Wiener filter as well as in estimating the noise-free signal. Our goal was to find a suitable filter bank and to choose other parameters of the Wiener filter with respect to the signal-to-noise ratio (SNR) obtained. Testing was performed on artificially noised signals from the standard CSE database sampled at 500 Hz. When creating an artificial interference, we started from the generated white Gaussian noise, whose power spectrum was modified according to a model of the power spectrum of an EMG signal. To improve the filtering performance, we used adaptive setting parameters of filtering according to the level of interference in the input signal. We were able to increase the average SNR of the whole test database by about 10.6 dB. The proposed algorithm provides better results than the classic wavelet Wiener filter. PMID:23192472

  9. Validation of heart rate derived from a physiological status monitor-embedded compression shirt against criterion ECG.

    PubMed

    Dolezal, B A; Boland, D M; Carney, J; Abrazado, M; Smith, D L; Cooper, C B

    2014-01-01

    Firefighters are subject to extreme environments and high physical demands when performing duty-related tasks. Recently, physiological status monitors (PSM) have been embedded into a compression shirt to enable firefighters to measure, visualize, log, and transmit vital metrics such as heart rate (HR) to aid in cardiovascular risk identification and mitigation, thereby attempting to improve the health, fitness, and safety of this population. The purpose of this study was to validate HR recorded by the PSM-embedded compression shirt against a criterion standard laboratory ECG-derived HR when worn concurrently with structural firefighting personal protective equipment (PPE) during four simulated firefighting activities. Ten healthy, college-age men (mean ± SD: age: 21 ± 1 yr; body mass: 91 ± 10 kg; body mass index: 26.9 ± 3.1 kg/m(2)) completed four tasks that are routinely performed during firefighting operations: outdoor fast-paced walking (FW), treadmill walking (TW), searching/crawling (SC), and ascending/descending stairs (AD). They wore the PSM-embedded compression shirt under structural firefighting PPE. HR was recorded concurrently by the PSM-embedded compression shirt and a portable metabolic measurement system accompanied with a standard 12-lead electrocardiograph that was used to provide criterion measures of HR. For all four tasks combined there was very high correlation of PSM and ECG HR (r > 0.99; SEE 0.84 /min) with a mean difference (bias) of -0.02 /min and limits of agreement of -0.07 to 0.02 /min. For individual tasks, the correlations were also high (r-values = 0.99; SEE 0.81-0.89). The mean bias (limits of agreement) was: FW 0.03 (-0.09 to 0.14); TW 0.04 (-0.05 to 0.12); SC -0.01 (-0.12 to 0.10); AD -0.13 (-0.21 to -0.04) /min. These findings demonstrate that the PSM-embedded compression shirt provides a valid measure of HR during simulated firefighting activities when compared with a standard 12-lead ECG.

  10. 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

  11. Standard-compliant real-time transmission of ECGs: harmonization of ISO/IEEE 11073-PHD and SCP-ECG.

    PubMed

    Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

    2009-01-01

    Ambient assisted living and integrated care in an aging society is based on the vision of the lifelong Electronic Health Record calling for HealthCare Information Systems and medical device interoperability. For medical devices this aim can be achieved by the consistent implementation of harmonized international interoperability standards. The ISO/IEEE 11073 (x73) family of standards is a reference standard for medical device interoperability. In its Personal Health Device (PHD) version several devices have been included, but an ECG device specialization is not yet available. On the other hand, the SCP-ECG standard for short-term diagnostic ECGs (EN1064) has been recently approved as an international standard ISO/IEEE 11073-91064:2009. In this paper, the relationships between a proposed x73-PHD model for an ECG device and the fields of the SCP-ECG standard are investigated. A proof-of-concept implementation of the proposed x73-PHD ECG model is also presented, identifying open issues to be addressed by standards development for the wider interoperability adoption of x73-PHD standards.

  12. 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.

  13. 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.

  14. A controlled study of a new ECG electrode system.

    PubMed

    Sheffield, L T; Roitman, D I; Kansal, S

    1978-07-01

    A newly marketed resting ECG electrode system was compared with conventional metal suction and plate electrodes, electrode cream and patient cable. Two experienced technicians were given special training in the use of the new electrode, electrolyte and patient cable system and alternated daily in using new and conventional equipment. Nearly equal numbers of perfect-scoring ECGs were recorded with each system, attesting to the impartiality of the technicians. A total of 1,062 ECGs were evaluated, 554 with the new system and 508 with the conventional one. ECG tracings were evaluated by electrocardiographers unaware of which system was used for each. A quantitative scoring system was used to measure the technical quality of each tracing in terms of baseline drift, powerline artifact and myographic plus miscellaneous artifacts. The new system received mean scores of 2.33, 3.08, and 2.72, respectively, while the conventional electrodes received scores of 2.56, 3.03 and 2.79. We concluded that the two types of electrodes produced ECGs of essentially equal quality.

  15. 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%.

  16. 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.

  17. 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

  18. 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.

  19. SLOPE--a real-time ECG data compressor.

    PubMed

    Tai, S C

    1991-03-01

    An ECG sampled at a rate of 250 samples s-1 or more produces a large amount of redundant data that are difficult to store and transmit. In the paper, a real-time ECG data compressor, SLOPE, is presented. SLOPE considers some adjacent samples as a vector, and this vector is extended if the coming sample falls in a fan spanned by this vector and a threshold angle; otherwise, it is delimited as a linear segment. By this means SLOPE repeatedly delimits linear segments of different lengths and different slopes. The Huffman codes for the parameters to describe this linear segment are transmitted for that linear segment. SLOPEa, which is a slightly modified version of SLOPE, is used to compress ambulatory ECG data. All the operations used by SLOPE and SLOPEa are simple integer operations, both SLOPE and SLOPEa being real-time compressors. Experimental results show that an average of 192 bits per channel per second (bpcs) for each ECG signal is obtained by SLOPE and an average of 148 bpcs for each ECG signal is obtained by SLOPEa.

  20. 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

  1. Design intelligent wheelchair with ECG measurement and wireless transmission function.

    PubMed

    Chou, Hsi-Chiang; Wang, Yi-Ming; Chang, Huai-Yuan

    2015-01-01

    The phenomenon of aging populations has produced widespread health awareness and magnified the need for improved medical quality and technologies. Statistics show that ischemic heart disease is the leading cause of death for older people and people with reduced mobility; therefore, wheelchairs have become their primary means of transport. Hence, an arrhythmia-detecting smart wheelchair was proposed in this study to provide real-time electrocardiography (ECG)-monitoring to patients with heart disease and reduced mobility. A self-developed, handheld ECG-sensing instrument was integrated with a wheelchair and a lab-written, arrhythmia-detecting program. The measured ECG data were transmitted through a Wi-Fi module and analyzed and diagnosed using the human-machine interface.

  2. 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.

  3. [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

  4. ECG compression: evaluation of FFT, DCT, and WT performance.

    PubMed

    GholamHosseini, H; Nazeran, H; Moran, B

    1998-12-01

    This work investigates a set of ECG data compression schemes to compare their performances in compressing and preparing ECG signals for automatic cardiac arrhythmia classification. These schemes are based on transform methods such as fast Fourier transform (FFT), discrete cosine transform (DCT), wavelet transform (WT), and their combinations. Each specific transform is applied to a pre-selected data segment from the MIT-BIH database and then compression is performed in the new domain. These transformation methods are known as an important class of ECG compression techniques. The WT has been shown as the most efficient method for further improvement. A compression ratio of 7.98 to 1 has been achieved with a percent of root mean square difference (PRD) of 0.25%, indicating that the wavelet compression technique offers the best performance over the other evaluated methods.

  5. Design intelligent wheelchair with ECG measurement and wireless transmission function.

    PubMed

    Chou, Hsi-Chiang; Wang, Yi-Ming; Chang, Huai-Yuan

    2015-01-01

    The phenomenon of aging populations has produced widespread health awareness and magnified the need for improved medical quality and technologies. Statistics show that ischemic heart disease is the leading cause of death for older people and people with reduced mobility; therefore, wheelchairs have become their primary means of transport. Hence, an arrhythmia-detecting smart wheelchair was proposed in this study to provide real-time electrocardiography (ECG)-monitoring to patients with heart disease and reduced mobility. A self-developed, handheld ECG-sensing instrument was integrated with a wheelchair and a lab-written, arrhythmia-detecting program. The measured ECG data were transmitted through a Wi-Fi module and analyzed and diagnosed using the human-machine interface. PMID:26444818

  6. 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.

  7. On ECG reconstruction using weighted-compressive sensing.

    PubMed

    Zonoobi, Dornoosh; Kassim, Ashraf A

    2014-06-01

    The potential of the new weighted-compressive sensing approach for efficient reconstruction of electrocardiograph (ECG) signals is investigated. This is motivated by the observation that ECG signals are hugely sparse in the frequency domain and the sparsity changes slowly over time. The underlying idea of this approach is to extract an estimated probability model for the signal of interest, and then use this model to guide the reconstruction process. The authors show that the weighted-compressive sensing approach is able to achieve reconstruction performance comparable with the current state-of-the-art discrete wavelet transform-based method, but with substantially less computational cost to enable it to be considered for use in the next generation of miniaturised wearable ECG monitoring devices.

  8. On ECG reconstruction using weighted-compressive sensing

    PubMed Central

    Kassim, Ashraf A.

    2014-01-01

    The potential of the new weighted-compressive sensing approach for efficient reconstruction of electrocardiograph (ECG) signals is investigated. This is motivated by the observation that ECG signals are hugely sparse in the frequency domain and the sparsity changes slowly over time. The underlying idea of this approach is to extract an estimated probability model for the signal of interest, and then use this model to guide the reconstruction process. The authors show that the weighted-compressive sensing approach is able to achieve reconstruction performance comparable with the current state-of-the-art discrete wavelet transform-based method, but with substantially less computational cost to enable it to be considered for use in the next generation of miniaturised wearable ECG monitoring devices. PMID:26609381

  9. A computationally efficient QRS detection algorithm for wearable ECG sensors.

    PubMed

    Wang, Y; Deepu, C J; Lian, Y

    2011-01-01

    In this paper we present a novel Dual-Slope QRS detection algorithm with low computational complexity, suitable for wearable ECG devices. The Dual-Slope algorithm calculates the slopes on both sides of a peak in the ECG signal; And based on these slopes, three criterions are developed for simultaneously checking 1)Steepness 2)Shape and 3)Height of the signal, to locate the QRS complex. The algorithm, evaluated against MIT/BIH Arrhythmia Database, achieves a very high detection rate of 99.45%, a sensitivity of 99.82% and a positive prediction of 99.63%. PMID:22255619

  10. 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.

  11. A Web-based tool for processing and visualizing body surface potential maps.

    PubMed

    Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George

    2010-01-01

    The body surface potential map (BSPM) is potentially more accurate for diagnosing cardiac pathologies when compared to the standard 12-lead electrocardiogram (ECG). However, a contributing factor to the lack of widespread adoption of the BSPM is the shortage of standard methods for its storage and visualization. Based on these observations, a BSPM storage format based on the eXtensible Markup Language has been developed within this study, alongside a Web-based BSPM viewer. This viewer was created using a lossless vector graphics tool (Adobe Flash) to maintain the quality of the ECG waveforms when they are enlarged. The viewer also runs inside the Web browser to facilitate BSPM visualization independent of the clinician's geographical location. This online nature enabled the creation of a comments system that can be used to assist in a collaborative diagnosis. This is useful because BSPM diagnostic criteria are not well established. Moreover, using the viewer's innovative tools (ie, calipers, isopotential maps), the clinician can explore BSPM datasets. Algorithms have also been integrated within the system to extract and display the 12-lead ECG and the vectorcardiogram from the BSPM. This viewer has been available online for 10 months alongside a Weblog, which has been used to record the user's feedback. During this period, 12 experts from both the clinical and visualization domains evaluated the viewer and contributed to its design. It has been the general consensus of all experts that the application is an effective solution for visualizing BSPMs. This viewer has been tested to visualize 2 different BSPMs using a PC (3 GHz CPU, 3 GB RAM, 6 MB broadband). The Lux-192 BSPM and the Kornreich-117 BSPM where both uploaded and visualized within 3.8 seconds (mean time from 10 trials). This BSPM storage format and its associated viewer provide a framework for a BSPM management system. If this system is made widely available, it has the potential to provide BSPM

  12. 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.

  13. Measurement of ventricular function by ECG gating during atrial fibrillation

    SciTech Connect

    Bacharach, S.L.; Green, M.V.; Bonow, R.O.; Findley, S.L.; Ostrow, H.G.; Johnston, G.S.

    1981-03-01

    The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR), and their times of occurrence (TPER, TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beam mean values were compared with the corresponding parameters calculated from one ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TACs irrespective of their length. For this population with slow heart rates, we find that the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF.

  14. 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.

  15. ECG gated NMR-CT for cardiovascular diseases

    SciTech Connect

    Nishikawa, J.; Ohtake, T.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.

    1985-05-01

    The authors have been applying ECG gated NMR-CT to mainly patients with myocardial infarction (MI), and hypertrophic cardiomyopathy (HCM). Thirteen patients with MI, 8 with HCM and 5 without any heart diseases were studied by ECG gated NMR imaging (spin-echo technique, TR: depends on patient heart rate, TE: 35 and 70 msec.) with 0.35 T superconducting magnet. On NMR images (MRI), the authors examined the wall thickness, wall motion and T/sub 2/ relaxation time in the area of diseased myocardium. The lesions of old MI were depicted as the area of thin wall and T/sub 2/ relaxation time of those lesions were similar to the area of non-infarcted myocardium. The lesions of recent MI (up to 3.5 months from the recent attack) were shown as the same wall thickness as the non-infarcted myocardium and the area of prolonged T/sub 2/ relaxation time compared with that of non-infarcted myocardium. MRI demonstrated diffusely thick myocardium in all patients with HCM. T/sub 2/ relaxation time of the areas of HCM was almost the same as that of normal myocardium, and it's difference among each ventricular wall in patients with HCM was not statistically significant. The authors conclude that ECG gated NMR-CT offers 3-D morphological information of the heart without any contrast material nor radioisotopes. ECG gated MRI provides the useful informations to diagnose MI, especially in the differential diagnosis between old and recent MI.

  16. 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…

  17. 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.

  18. [Fetal ECG monitoring system based on MCU processing].

    PubMed

    Hu, Gang; Chen, Wei; Xie, Xicheng; Zhang, Hao

    2004-12-01

    In order to monitor the fetus in labor, the signal characteristic from fetal scalp electrode is researched, An adaptation algorithm and a peak to peak detecting technology are adopted in signal processing, and an adaptation gain control method is used to eliminate disturber from base-line shift. A fetal ECG monitoring system is designed on the basis of C8051F020 MCU.

  19. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic ECG/respirator synchronizer. 892.1970 Section 892.1970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic...

  20. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic ECG/respirator synchronizer. 892.1970 Section 892.1970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic...

  1. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic ECG/respirator synchronizer. 892.1970 Section 892.1970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic...

  2. Influence of Mobile Phones on the Quality of ECG Signal Acquired by Medical Devices

    NASA Astrophysics Data System (ADS)

    Buczkowski, T.; Janusek, D.; Zavala-Fernandez, H.; Skrok, M.; Kania, M.; Liebert, A.

    2013-10-01

    Health aspects of the use of radiating devices, like mobile phones, are still a public concern. Stand-alone electrocardiographic systems and those built-in, more sophisticated, medical devices have become a standard tool used in everyday medical practice. GSM mobile phones might be a potential source of electromagnetic interference (EMI) which may affect reliability of medical appliances. Risk of such event is particularly high in places remote from GSM base stations in which the signal received by GSM mobile phone is weak. In such locations an increase in power of transmitted radio signal is necessary to enhance quality of the communication. In consequence, the risk of interference of electronic devices increases because of the high level of EMI. In the present paper the spatial, temporal, and spectral characteristics of the interference have been examined. The influence of GSM mobile phone on multilead ECG recordings was studied. It was observed that the electrocardiographic system was vulnerable to the interference generated by the GSM mobile phone working with maximum transmit power and in DTX mode when the device was placed in a distance shorter than 7.5 cm from the ECG electrode located on the surface of the chest. Negligible EMI was encountered at any longer distance.

  3. 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.

  4. Detection of driving fatigue by using noncontact EMG and ECG signals measurement system.

    PubMed

    Fu, Rongrong; Wang, Hong

    2014-05-01

    Driver fatigue can be detected by constructing a discriminant mode using some features obtained from physiological signals. There exist two major challenges of this kind of methods. One is how to collect physiological signals from subjects while they are driving without any interruption. The other is to find features of physiological signals that are of corresponding change with the loss of attention caused by driver fatigue. Driving fatigue is detected based on the study of surface electromyography (EMG) and electrocardiograph (ECG) during the driving period. The noncontact data acquisition system was used to collect physiological signals from the biceps femoris of each subject to tackle the first challenge. Fast independent component analysis (FastICA) and digital filter were utilized to process the original signals. Based on the statistical analysis results given by Kolmogorov-Smirnov Z test, the peak factor of EMG (p < 0.001) and the maximum of the cross-relation curve of EMG and ECG (p < 0.001) were selected as the combined characteristic to detect fatigue of drivers. The discriminant criterion of fatigue was obtained from the training samples by using Mahalanobis distance, and then the average classification accuracy was given by 10-fold cross-validation. The results showed that the method proposed in this paper can give well performance in distinguishing the normal state and fatigue state. The noncontact, onboard vehicle drivers' fatigue detection system was developed to reduce fatigue-related risks.

  5. Mobile measurement system of ECG signal in vehicle environment

    NASA Astrophysics Data System (ADS)

    Oh, Kwang-seok; Lee, Sang-Ryong; Lee, Choon-Young; Kim, Myun-Hee

    2005-12-01

    This paper proposed a new method to measure the ECG signal from the driver. The ECG signal is often measured in the room. But it is mixed with many kinds of noise when it is measured during the vehicle moving. Noise occupied most many parts as the experimental among them was classified. And one suitable filter for each noise was designed. It used ALE(Adaptive Line Enhancement) to remove the noise occurred to electromagnetic wave in vehicle. To remove the noise occurred to steering or vibration of vehicle, the paper used Wavelet transformation after ALE(preprocessing filter). To realize unconscious measurement, this research used the stainless steel(not the electrode) fixed at steering wheel and designed the adaptive filter without using reference signal.

  6. 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.

  7. 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.

  8. 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.

  9. ECG contamination of EEG signals: effect on entropy.

    PubMed

    Chakrabarti, Dhritiman; Bansal, Sonia

    2016-02-01

    Entropy™ is a proprietary algorithm which uses spectral entropy analysis of electroencephalographic (EEG) signals to produce indices which are used as a measure of depth of hypnosis. We describe a report of electrocardiographic (ECG) contamination of EEG signals leading to fluctuating erroneous Entropy values. An explanation is provided for mechanism behind this observation by describing the spread of ECG signals in head and neck and its influence on EEG/Entropy by correlating the observation with the published Entropy algorithm. While the Entropy algorithm has been well conceived, there are still instances in which it can produce erroneous values. Such erroneous values and their cause may be identified by close scrutiny of the EEG waveform if Entropy values seem out of sync with that expected at given anaesthetic levels.

  10. 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.

  11. Patient ECG recording control for an automatic implantable defibrillator

    NASA Technical Reports Server (NTRS)

    Fountain, Glen H. (Inventor); Lee, Jr., David G. (Inventor); Kitchin, David A. (Inventor)

    1986-01-01

    An implantable automatic defibrillator includes sensors which are placed on or near the patient's heart to detect electrical signals indicative of the physiology of the heart. The signals are digitally converted and stored into a FIFO region of a RAM by operation of a direct memory access (DMA) controller. The DMA controller operates transparently with respect to the microprocessor which is part of the defibrillator. The implantable defibrillator includes a telemetry communications circuit for sending data outbound from the defibrillator to an external device (either a patient controller or a physician's console or other) and a receiver for sensing at least an externally generated patient ECG recording command signal. The patient recording command signal is generated by the hand held patient controller. Upon detection of the patient ECG recording command, DMA copies the contents of the FIFO into a specific region of the RAM.

  12. 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

  13. Discussion of "Computational Electrocardiography: Revisiting Holter ECG Monitoring".

    PubMed

    Baumgartner, Christian; Caiani, Enrico G; Dickhaus, Hartmut; Kulikowski, Casimir A; Schiecke, Karin; van Bemmel, Jan H; Witte, Herbert

    2016-08-01

    This article is part of a For-Discussion-Section of Methods of Information in Medicine about the paper "Computational Electrocardiography: Revisiting Holter ECG Monitoring" written by Thomas M. Deserno and Nikolaus Marx. It is introduced by an editorial. This article contains the combined commentaries invited to independently comment on the paper of Deserno and Marx. In subsequent issues the discussion can continue through letters to the editor.

  14. Capacitive driven-right-leg grounding in Indirect-contact ECG measurement.

    PubMed

    Lim, Yong Gyu; Chung, Gih Sung; Park, Kwang Suk

    2010-01-01

    For the reduction of common-mode noise level in Indirect-contact ECG (IDC-ECG) measurement, a driven-right-leg grounding method was applied to the IDC-ECG. Because the IDC-ECG does not require any direct contact between the electrodes and the human skin, it is adequate for un-constraining long-term ECG measurement at home and its various applications are now under development. However, larger 60 Hz noise induced by power line appears in IDC-ECG than in conventional ECG, that is a restriction of IDC-ECG application. In this study, the driven-right-leg ground which has been used in conventional direct-contact ECG, was adapted to the IDC-ECG measurement, by feedback of the inversion of amplified common-mode noise to the body through the conductive textile laid on the chair seat. It was shown that the level of 60Hz power line noise was reduced to about -40 dB when the driven-right-leg gain was 1000.

  15. 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

  16. Capacitive driven-right-leg grounding in Indirect-contact ECG measurement.

    PubMed

    Lim, Yong Gyu; Chung, Gih Sung; Park, Kwang Suk

    2010-01-01

    For the reduction of common-mode noise level in Indirect-contact ECG (IDC-ECG) measurement, a driven-right-leg grounding method was applied to the IDC-ECG. Because the IDC-ECG does not require any direct contact between the electrodes and the human skin, it is adequate for un-constraining long-term ECG measurement at home and its various applications are now under development. However, larger 60 Hz noise induced by power line appears in IDC-ECG than in conventional ECG, that is a restriction of IDC-ECG application. In this study, the driven-right-leg ground which has been used in conventional direct-contact ECG, was adapted to the IDC-ECG measurement, by feedback of the inversion of amplified common-mode noise to the body through the conductive textile laid on the chair seat. It was shown that the level of 60Hz power line noise was reduced to about -40 dB when the driven-right-leg gain was 1000. PMID:21095911

  17. 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.

  18. 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

  19. An ECG analysis interactive training system for understanding arrhythmias.

    PubMed

    Lessard, Yvon; Sinteff, Jean-Paul; Siregar, Pridi; Julen, Nathalie; Hannouche, Frédéric; Rio, Stéphane; Le Beux, Pierre

    2009-01-01

    The ECG remains a daily diagnostic tool for the detection of numerous cardiovascular diseases. Our goal was to use a computerized qualitative model (QM) of heart in order to build cases of simple arrhythmias dedicated to initial and more advanced medical teaching. The original QM is able to generate videograms of many cardiac disturbances. A Flash player is used to view ECG, synchronous Lewis diagram and chromatic 2D cardiac animation of a specific case. OAAT is a standardized 18 yes/no answers questionnaire which allows the learner to diagnose five main types of arrhythmias that can be compared with normal sinus rhythm (NSR) analysis. This new tool has been recently used by medical students during practical sessions. Based on medical reasoning learning on NSR video and upon trying to recognize an abnormal cardiac rhythm, all users can reach the 100% winning score since they can perform as many attempts as they like. We believe that unlimited case review with questionnaire answering, ECG and Lewis diagram replay and step-by-step visualization of the abnormal propagation of the cardiac impulse on the 2D heart videos are a highly efficient means to help students understand even complex arrhythmic mechanisms.

  20. 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.

  1. An ECG analysis interactive training system for understanding arrhythmias.

    PubMed

    Lessard, Yvon; Sinteff, Jean-Paul; Siregar, Pridi; Julen, Nathalie; Hannouche, Frédéric; Rio, Stéphane; Le Beux, Pierre

    2009-01-01

    The ECG remains a daily diagnostic tool for the detection of numerous cardiovascular diseases. Our goal was to use a computerized qualitative model (QM) of heart in order to build cases of simple arrhythmias dedicated to initial and more advanced medical teaching. The original QM is able to generate videograms of many cardiac disturbances. A Flash player is used to view ECG, synchronous Lewis diagram and chromatic 2D cardiac animation of a specific case. OAAT is a standardized 18 yes/no answers questionnaire which allows the learner to diagnose five main types of arrhythmias that can be compared with normal sinus rhythm (NSR) analysis. This new tool has been recently used by medical students during practical sessions. Based on medical reasoning learning on NSR video and upon trying to recognize an abnormal cardiac rhythm, all users can reach the 100% winning score since they can perform as many attempts as they like. We believe that unlimited case review with questionnaire answering, ECG and Lewis diagram replay and step-by-step visualization of the abnormal propagation of the cardiac impulse on the 2D heart videos are a highly efficient means to help students understand even complex arrhythmic mechanisms. PMID:19745450

  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. Unsupervised feature relevance analysis applied to improve ECG heartbeat clustering.

    PubMed

    Rodríguez-Sotelo, J L; Peluffo-Ordoñez, D; Cuesta-Frau, D; Castellanos-Domínguez, G

    2012-10-01

    The computer-assisted analysis of biomedical records has become an essential tool in clinical settings. However, current devices provide a growing amount of data that often exceeds the processing capacity of normal computers. As this amount of information rises, new demands for more efficient data extracting methods appear. This paper addresses the task of data mining in physiological records using a feature selection scheme. An unsupervised method based on relevance analysis is described. This scheme uses a least-squares optimization of the input feature matrix in a single iteration. The output of the algorithm is a feature weighting vector. The performance of the method was assessed using a heartbeat clustering test on real ECG records. The quantitative cluster validity measures yielded a correctly classified heartbeat rate of 98.69% (specificity), 85.88% (sensitivity) and 95.04% (general clustering performance), which is even higher than the performance achieved by other similar ECG clustering studies. The number of features was reduced on average from 100 to 18, and the temporal cost was a 43% lower than in previous ECG clustering schemes. PMID:22672933

  4. Compressive sensing exploiting wavelet-domain dependencies for ECG compression

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    Compressive sensing (CS) is an emerging signal processing paradigm that enables sub-Nyquist sampling of sparse signals. Extensive previous work has exploited the sparse representation of ECG signals in compression applications. In this paper, we propose the use of wavelet domain dependencies to further reduce the number of samples in compressive sensing-based ECG compression while decreasing the computational complexity. R wave events manifest themselves as chains of large coefficients propagating across scales to form a connected subtree of the wavelet coefficient tree. We show that the incorporation of this connectedness as additional prior information into a modified version of the CoSaMP algorithm can significantly reduce the required number of samples to achieve good quality in the reconstruction. This approach also allows more control over the ECG signal reconstruction, in particular, the QRS complex, which is typically distorted when prior information is not included in the recovery. The compression algorithm was tested upon records selected from the MIT-BIH arrhythmia database. Simulation results show that the proposed algorithm leads to high compression ratios associated with low distortion levels relative to state-of-the-art compression algorithms.

  5. Unsupervised feature relevance analysis applied to improve ECG heartbeat clustering.

    PubMed

    Rodríguez-Sotelo, J L; Peluffo-Ordoñez, D; Cuesta-Frau, D; Castellanos-Domínguez, G

    2012-10-01

    The computer-assisted analysis of biomedical records has become an essential tool in clinical settings. However, current devices provide a growing amount of data that often exceeds the processing capacity of normal computers. As this amount of information rises, new demands for more efficient data extracting methods appear. This paper addresses the task of data mining in physiological records using a feature selection scheme. An unsupervised method based on relevance analysis is described. This scheme uses a least-squares optimization of the input feature matrix in a single iteration. The output of the algorithm is a feature weighting vector. The performance of the method was assessed using a heartbeat clustering test on real ECG records. The quantitative cluster validity measures yielded a correctly classified heartbeat rate of 98.69% (specificity), 85.88% (sensitivity) and 95.04% (general clustering performance), which is even higher than the performance achieved by other similar ECG clustering studies. The number of features was reduced on average from 100 to 18, and the temporal cost was a 43% lower than in previous ECG clustering schemes.

  6. [Methods for the detection of ventricular late potentials. High amplification ECG, signal averaging technic, frequency analysis and intracardiac mapping].

    PubMed

    Hombach, V; Eggeling, T; Höher, M; Höpp, H W; Kochs, M; Giel, I; Emsermann, P; Hirche, H; Hilger, H H

    1988-06-01

    Circumscribed areas of injured myocardium which lead to late ventricular depolarization represent the pathologic-anatomic substrate for reentry mechanisms potentially capable of propagating ventricular tachycardia at the ventricular level. If the myocardial area from which delayed ventricular depolarization and, consequently, late potentials eminate, exceeds a critical minimal size, documentation of such signals can not only be achieved with direct endocardial mapping or catheter mapping but also by means of special high-resolution ECG techniques from the body surface. Since high amplification of the conventional ECG results in registration of noise signals in amplitude of up to 50 microV, late potentials with their amplitudes at the body surface ranging from 5 to a maximum of 20 microV, can only be discriminated after substantial enhancement of the signal-to-noise ratio. The noise arises from no less than three sources: physiologic noise, for example, from muscle activity; electronic noise from amplifiers and background noise of 50 or 60 Hz, respectively. To improve the signal-to-noise ratio, currently three methods are employed: sequential or temporal signal averaging, spatial signal averaging and fast Fourier transformation analysis of the frequency spectrum of the highly-amplified ECG. Temporal signal averaging has the purpose of smoothing randomly-occurring background noise and, at a specified point in time of the ECG cycle, to sum the signal incurred. The effectivity of this technique, however, is subject to certain conditions: the signal to be registered and the background noise must be independent from each other, the noise must be stationary and show normal random distribution, the signal of interest must be periodic and/or coupled with a fixed interval to a point in the ECG cycle which can be used as a trigger. The quality of the averaged signal is dependent on trigger stability. There are three approaches to trigger processing: voltage threshold

  7. A Comparison of IIR and Wavelet Filtering for Noise Reduction of the ECG

    PubMed Central

    Sørensen, JS; Johannesen, L; Grove, USL; Lundhus, K; Couderc, J-P; Graff, C

    2011-01-01

    This study compares the ability to preserve information and reduce noise contaminants on the ECG for five wavelet filters and three IIR filters. Two 3-lead Holter ECGs were used. White Gaussian Noise was added to the first ECG in increments of 10% coverage. The second ECG contained alternating muscle transients and noise-free segments. Computation times and SNR improvements for different noise coverages were calculated and compared. RMS errors were calculated from noise-free segments on the ECG with transient muscle noise. Wavelet filters improved SNR more than IIR filters when the signal coverage was more than 50% noise. In contrast, the computation times were shorter for IIR filters (6 s) than for wavelet filters (88 s). On the ECG with transient muscle noise there was a trade-off in performance between wavelet and IIR filtering. In a clinical setting where the amount of noise is unknown, using IIR filters appears to be preferred for consistent performance. PMID:22068831

  8. [Design of the Mobile ECG Monitoring System Based on Android 4.3].

    PubMed

    Zhang, Shun; Lian, Yuxi; Qin, Yajie; Wang, Yuanyuan

    2015-07-01

    To monitor and record Electrocardiograph (ECG) signals for 24 hours, a mobile ECG monitoring system is designed based on Android 4.3. In this system, domestic indigenous E9622A is used to acquire ECG signals and TI CC2541 is adopted to communicate with mobile phones. The program is implemented on the Android platform to display and process ECG signals. The whole system is integrated on a 2 cm x 2 cm PCB. From experiments, it is shown that ECG signals can be obtained effectively when this system is worn, and clear ECG waveforms and parameters can be shown on the phones. With this system, arrhythmia can be diagnosed preliminarily. It is also shown that the system is low-power, low-cost, flexible and portable.

  9. 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

  10. The Telemetric and Holter ECG Warehouse (THEW): the first three years of development and research.

    PubMed

    Couderc, Jean-Philippe

    2012-01-01

    The Telemetric and Holter ECG Warehouse (THEW) hosts more than 3700 digital 24-Holter ECG recordings from 13 independent studies. In addition to the ECGs, the repository includes patient information in separate clinical database with content varying according to the study focus. In its third year of activities, the THEW database has been accessed by researchers from 37 universities and 16 corporations located in 16 countries worldwide. Twenty publications were released primarily focusing on the development and validation of ECG-based technologies. This communication describes the content of the databases of the repository with brief summary of the research and development projects completed using these data.

  11. 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.

  12. 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.

  13. A novel approach to ECG classification based upon two-layered HMMs in body sensor networks.

    PubMed

    Liang, Wei; Zhang, Yinlong; Tan, Jindong; Li, Yang

    2014-03-27

    This paper presents a novel approach to ECG signal filtering and classification. Unlike the traditional techniques which aim at collecting and processing the ECG signals with the patient being still, lying in bed in hospitals, our proposed algorithm is intentionally designed for monitoring and classifying the patient's ECG signals in the free-living environment. The patients are equipped with wearable ambulatory devices the whole day, which facilitates the real-time heart attack detection. In ECG preprocessing, an integral-coefficient-band-stop (ICBS) filter is applied, which omits time-consuming floating-point computations. In addition, two-layered Hidden Markov Models (HMMs) are applied to achieve ECG feature extraction and classification. The periodic ECG waveforms are segmented into ISO intervals, P subwave, QRS complex and T subwave respectively in the first HMM layer where expert-annotation assisted Baum-Welch algorithm is utilized in HMM modeling. Then the corresponding interval features are selected and applied to categorize the ECG into normal type or abnormal type (PVC, APC) in the second HMM layer. For verifying the effectiveness of our algorithm on abnormal signal detection, we have developed an ECG body sensor network (BSN) platform, whereby real-time ECG signals are collected, transmitted, displayed and the corresponding classification outcomes are deduced and shown on the BSN screen.

  14. Embedding patients confidential data in ECG signal for healthcare information systems.

    PubMed

    Ibaida, Ayman; Khalil, Ibrahim; Al-Shammary, Dhiah

    2010-01-01

    In Wireless tele-cardiology applications, ECG signal is widely used to monitor cardiac activities of patients. Accordingly, in most e-health applications, ECG signals need to be combined with patient confidential information. Data hiding and watermarking techniques can play a crucial role in ECG wireless tele-monitoring systems by combining the confidential information with the ECG signal since digital ECG data is huge enough to act as host to carry tiny amount of additional secret data. In this paper, a new steganography technique is proposed that helps embed confidential information of patients into specific locations (called special range numbers) of digital ECG host signal that will cause minimal distortion to ECG, and at the same time, any secret information embedded is completely extractable. We show that there are 2.1475 × 10(9) possible special range numbers making it extremely difficult for intruders to identify locations of secret bits. Experiments show that percentage residual difference (PRD) of watermarked ECGs can be as low as 0.0247% and 0.0678% for normal and abnormal ECG segments (taken from MIT-BIH Arrhythmia database) respectively.

  15. 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

  16. Cardiac Repolarization Abnormalities and Potential Evidence for Loss of Cardiac Sodium Currents on ECGs of Patients with Chagas' Heart Disease

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    Some individuals with Chagas disease develop right precordial lead ST segment elevation in response to an ajmaline challenge test, and the prevalence of right bundle branch block (RBBB) is also high in Chagas disease. Because these same electrocardiographic abnormalities occur in the Brugada syndrome, which involves genetically defective cardiac sodium channels, acquired damage to cardiac sodium channels may also occur in Chagas disease. We studied several conventional and advanced resting 12-lead/derived Frank-lead ECG parameters in 34 patients with Chagas -related heart disease (mean age 39 14 years) and in 34 age-/gender-matched healthy controls. All ECG recordings were of 5-10 min duration, obtained in the supine position using high fidelity hardware/software (CardioSoft, Houston, TX). Even after excluding those Chagas patients who had resting BBBs, tachycardia and/or pathologic arrhythmia (n=8), significant differences remained in multiple conventional and advanced ECG parameters between the Chagas and control groups (n=26/group), especially in their respective QT interval variability indices, maximal spatial QRS-T angles and low frequency HRV powers (p=0.0006, p=0.0015 and p=0.0314 respectively). In relation to the issue of potential damage to cardiac sodium channels, the Chagas patients had: 1) greater than or equal to twice the incidence of resting ST segment elevation in leads V1-V3 (n=10/26 vs. n=5/26) and of both leftward (n=5/26 versus n=0/26) and rightward (n=7/26 versus n=3/26) QRS axis deviation than controls; 2) significantly increased filtered (40-250 Hz) QRS interval durations (92.1 8.5 versus 85.3 plus or minus 9.0 ms, p=0.022) versus controls; and 3) significantly decreased QT and especially JT interval durations versus controls (QT interval: 387.5 plus or minus 26.4 versus 408.9 plus or minus 34.6 ms, p=0.013; JT interval: 290.5 plus or minus 26.3 versus 314.8 plus or minus 31.3 ms; p=0.0029). Heart rates and Bazett-corrected QTc/JTc intervals

  17. 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.

  18. ECG in stress testing: child of a lesser diagnostic god?

    PubMed

    Longo, S; Del Negro, B; Picano, E

    1997-01-01

    When new technologies are added to the previously existing ones, the latter can be prematurely discarded and judged obsolete not only on the basis of rational scientific facts, but also on irrational trends. Old techniques, like electrocardiography, suffer from diagnostic ambiguities that can be solved by combination with a cardiac imaging technique, like stress echocardiography. ECG monitoring during all forms of stress testing can still offer surprising dividends for a better understanding of the complex physiology of coronary artery disease, a better clinical characterization of patients with microvascular angina, and may serve as an important adjunct marker to cardiac imaging techniques. PMID:9350596

  19. Real-time ECG algorithms for ambulatory patient monitoring.

    PubMed

    Pino, Esteban; Ohno-Machado, Lucila; Wiechmann, Eduardo; Curtis, Dorothy

    2005-01-01

    Brigham & Women's Hospital is designing a wireless monitoring system for patients on the waiting area of the Emergency Department. A real-time ECG algorithm is required to monitor and alert changes in patients that have not yet been admitted to the Emergency Room. For this purpose, three simple algorithms are compared in terms of processing time, beat detection accuracy and heart rate (HR) estimation. Varying amounts of noise were added to records from the MIT-BIH Arrhythmia Database [1] to mimic expected waiting room conditions. Some recommendations regarding selection of an algorithm and further processing of HR series are presented.

  20. 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

  1. ECG of the Month: Subtle ECG Change in a 31 Year-Old Man with Recent Chest Pain.

    PubMed

    Glancy, D Luke

    2016-01-01

    A 31-year-old man had an hour of pain across the upper portion of his chest anteriorly, and it radiated down the inner aspects of both arms. The pain came while he was walking and gradually disappeared as he sat quietly. Six Rolaid tablets did not seem to alter the pain. The pain was unaccompanied by dyspnea, sweating, nausea or vomiting. The night before the patient had had similar pain relieved by Rolaids and belching. After the second episode of pain, he went to the emergency department of a local hospital where an ECG was recorded. PMID:27598900

  2. Binary optimization for source localization in the inverse problem of ECG.

    PubMed

    Potyagaylo, Danila; Cortés, Elisenda Gil; Schulze, Walther H W; Dössel, Olaf

    2014-09-01

    The goal of ECG-imaging (ECGI) is to reconstruct heart electrical activity from body surface potential maps. The problem is ill-posed, which means that it is extremely sensitive to measurement and modeling errors. The most commonly used method to tackle this obstacle is Tikhonov regularization, which consists in converting the original problem into a well-posed one by adding a penalty term. The method, despite all its practical advantages, has however a serious drawback: The obtained solution is often over-smoothed, which can hinder precise clinical diagnosis and treatment planning. In this paper, we apply a binary optimization approach to the transmembrane voltage (TMV)-based problem. For this, we assume the TMV to take two possible values according to a heart abnormality under consideration. In this work, we investigate the localization of simulated ischemic areas and ectopic foci and one clinical infarction case. This affects only the choice of the binary values, while the core of the algorithms remains the same, making the approximation easily adjustable to the application needs. Two methods, a hybrid metaheuristic approach and the difference of convex functions (DC), algorithm were tested. For this purpose, we performed realistic heart simulations for a complex thorax model and applied the proposed techniques to the obtained ECG signals. Both methods enabled localization of the areas of interest, hence showing their potential for application in ECGI. For the metaheuristic algorithm, it was necessary to subdivide the heart into regions in order to obtain a stable solution unsusceptible to the errors, while the analytical DC scheme can be efficiently applied for higher dimensional problems. With the DC method, we also successfully reconstructed the activation pattern and origin of a simulated extrasystole. In addition, the DC algorithm enables iterative adjustment of binary values ensuring robust performance.

  3. Analysis of ECG from pole-zero models.

    PubMed

    Murthy, I S; Prasad, G S

    1992-07-01

    A complete solution to the fundamental problem of ECG analysis, viz., delineation of the signal into its component waves, is proposed from a system theoretic point of view. The discrete cosine transform of a bell shaped biphasic function is approximated mathematically by a system function with two poles and two zeros, i.e., of order (2, 2). Using this concept as the basis, a pole-zero model of suitable order is derived from the discrete cosine transform (DCT) of the given signal using Steiglitz-McBride method. This model is expanded into a unique set of partial fractions each of order (2, 2), and a biphasic function is recovered from each one of these fractions in the inverse process. Each of the P and T waves usually requires only one biphasic function, while the QRS complex needs two or at most three such fractions. A one-to-one relationship between the pole pattern in the z-plane and component wave pattern in the time signal is established. Results of analysis of continuous strips of ECG show that the delineated component waves are in excellent agreement with the original waves both qualitatively and quantitatively. The method is robust for the analysis of signals with artifacts of various kinds, independent of the sampling rate used, and is free from ad hoc back and forth search procedures. PMID:1516941

  4. The development of wireless sensor network for ECG monitoring.

    PubMed

    Lin, Jun-Liang; Liu, Hsien-Chieh; Tai, Yu-Ting; Wu, Hsin-Hsien; Hsu, Shuo-Jen; Jaw, Fu-Shan; Chen, You-Yin

    2006-01-01

    The main problem we want to solve contains two subjects: The first one is the patient's pressure due to wired physiological signal estimation. With wireless sensor network technique, patients only need to carry a few small nodes, and then the physiological signal can be transmitted in the air. The other subject of the vital problem is that some protocols, like Bluetooth, provide a peer to peer wireless communication technique, but such peer to peer network may need a complex algorithm to find the best data transmission path. In this study, we use the hierarchy routing as network topology that three-layer architecture contains PAN coordinator, router and device. The study focuses on implementation of a prototype electrocardiography (ECG) system which replaces wired connections between sensor points and a central node with wireless links. Successful implementation of the final system would be of benefit to all involved in the use of ECG as access to and movement of the patient would not be impeded by the physical constraints imposed by the cables. Most aspects of the design would also be portable to other sensor applications, making the work relevant to a vast range of systems where movement of sensors is desirable and constrained by hard-wired links. PMID:17946570

  5. Ubiquitous wireless ECG recording: a powerful tool physicians should embrace.

    PubMed

    Saxon, Leslie A

    2013-04-01

    The use of smart phones has increased dramatically and there are nearly a billion users on 3G and 4G networks worldwide. Nearly 60% of the U.S. population uses smart phones to access the internet, and smart phone sales now surpass those of desktop and laptop computers. The speed of wireless communication technology on 3G and 4G networks and the widespread adoption and use of iOS equipped smart phones (Apple Inc., Cupertino, CA, USA) provide infrastructure for the transmission of wireless biomedical data, including ECG data. These technologies provide an unprecedented opportunity for physicians to continually access data that can be used to detect issues before symptoms occur or to have definitive data when symptoms are present. The technology also greatly empowers and enables the possibility for unprecedented patient participation in their own medical education and health status as well as that of their social network. As patient advocates, physicians and particularly cardiac electrophysiologists should embrace the future and promise of wireless ECG recording, a technology solution that can truly scale across the global population.

  6. 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

  7. 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

  8. 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

  9. 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

  10. A novel approach for an ECG electrode integrated into a transcutaneous sensor.

    PubMed

    Hölscher, U

    1987-01-01

    The integration of an ECG-electrode into a common transcutaneous sensor allows simple handling and leads to a reduction of the physiological stress of pre-term infants. Furthermore it may allow future replacement of an invasive method to measure the ECG under labour by a non-invasive one.

  11. Interactive Videoconference Supported Teaching in Undergraduate Nursing: A Case Study for ECG

    ERIC Educational Resources Information Center

    Celikkan, Ufuk; Senuzun, Fisun; Sari, Dilek; Sahin, Yasar Guneri

    2013-01-01

    This paper describes how interactive videoconference can benefit the Electrocardiography (ECG) skills of undergraduate nursing students. We have implemented a learning system that interactively transfers the visual and practical aspects of ECG from a nursing skills lab into a classroom where the theoretical part of the course is taught. The…

  12. Effects of electrocardiography contamination and comparison of ECG removal methods on upper trapezius electromyography recordings.

    PubMed

    Marker, Ryan J; Maluf, Katrina S

    2014-12-01

    Electromyography (EMG) recordings from the trapezius are often contaminated by the electrocardiography (ECG) signal, making it difficult to distinguish low-level muscle activity from muscular rest. This study investigates the influence of ECG contamination on EMG amplitude and frequency estimations in the upper trapezius during muscular rest and low-level contractions. A new method of ECG contamination removal, filtered template subtraction (FTS), is described and compared to 30 Hz high-pass filter (HPF) and averaged template subtraction (ATS) methods. FTS creates a unique template of each ECG artifact using a low-pass filtered copy of the contaminated signal, which is subtracted from contaminated periods in the original signal. ECG contamination results in an over-estimation of EMG amplitude during rest in the upper trapezius, with negligible effects on amplitude and frequency estimations during low-intensity isometric contractions. FTS and HPF successfully removed ECG contamination from periods of muscular rest, yet introduced errors during muscle contraction. Conversely, ATS failed to fully remove ECG contamination during muscular rest, yet did not introduce errors during muscle contraction. The relative advantages and disadvantages of different ECG contamination removal methods should be considered in the context of the specific motor tasks that require analysis.

  13. Interoperability in digital electrocardiography: harmonization of ISO/IEEE x73-PHD and SCP-ECG.

    PubMed

    Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Serrano, Luis; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

    2010-11-01

    The ISO/IEEE 11073 (x73) family of standards is a reference frame for medical device interoperability. A draft for an ECG device specialization (ISO/IEEE 11073-10406-d02) has already been presented to the Personal Health Device (PHD) Working Group, and the Standard Communications Protocol for Computer-Assisted ElectroCardioGraphy (SCP-ECG) Standard for short-term diagnostic ECGs (EN1064:2005+A1:2007) has recently been approved as part of the x73 family (ISO 11073-91064:2009). These factors suggest the coordinated use of these two standards in foreseeable telecardiology environments, and hence the need to harmonize them. Such harmonization is the subject of this paper. Thus, a mapping of the mandatory attributes defined in the second draft of the ISO/IEEE 11073-10406-d02 and the minimum SCP-ECG fields is presented, and various other capabilities of the SCP-ECG Standard (such as the messaging part) are also analyzed from an x73-PHD point of view. As a result, this paper addresses and analyzes the implications of some inconsistencies in the coordinated use of these two standards. Finally, a proof-of-concept implementation of the draft x73-PHD ECG device specialization is presented, along with the conversion from x73-PHD to SCP-ECG. This paper, therefore, provides recommendations for future implementations of telecardiology systems that are compliant with both x73-PHD and SCP-ECG.

  14. 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.

  15. 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

  16. A review on digital ECG formats and the relationships between them.

    PubMed

    Trigo, Jesús Daniel; Alesanco, Alvaro; Martínez, Ignacio; García, José

    2012-05-01

    A plethora of digital ECG formats have been proposed and implemented. This heterogeneity hinders the design and development of interoperable systems and entails critical integration issues for the healthcare information systems. This paper aims at performing a comprehensive overview on the current state of affairs of the interoperable exchange of digital ECG signals. This includes 1) a review on existing digital ECG formats, 2) a collection of applications and cardiology settings using such formats, 3) a compilation of the relationships between such formats, and 4) a reflection on the current situation and foreseeable future of the interoperable exchange of digital ECG signals. The objectives have been approached by completing and updating previous reviews on the topic through appropriate database mining. 39 digital ECG formats, 56 applications, tools or implantation experiences, 47 mappings/converters, and 6 relationships between such formats have been found in the literature. The creation and generalization of a single standardized ECG format is a desirable goal. However, this unification requires political commitment and international cooperation among different standardization bodies. Ongoing ontology-based approaches covering ECG domain have recently emerged as a promising alternative for reaching fully fledged ECG interoperability in the near future.

  17. Mechanisms of exercise-recovery hysteresis in the ECG: ISCE 2015 paper.

    PubMed

    Swenne, Cees A

    2015-01-01

    This paper gives an overview of multiple factors, like the mechanisms governing rate adaptation of ventricular action potentials and autonomic mechanisms, which play a role in the genesis of exercise-recovery hysteresis in the ECG. It also discusses the possible association between exercise-recovery ECG hysteresis and arrhythmogeneity.

  18. Relative Amplitude based Features of characteristic ECG-Peaks for Identification of Coronary Artery Disease

    NASA Astrophysics Data System (ADS)

    Gohel, Bakul; Tiwary, U. S.; Lahiri, T.

    Coronary artery disease or Myocardial Infarction is the leading cause of death and disability in the world. ECG is widely used as a cheap diagnostic tool for diagnosis of coronary artery disease but has low sensitivity with the present criteria based on ST-segment, T wave and Q wave changes. So to increase the sensitivity of the ECG we have introduced relative amplitude based new features of characteristic ‘R’ and ‘S’ ECG-peaks between two leads. Relative amplitude based features shows remarkable capability in discriminating Myocardial Infarction and Healthy pattern using backpropogation neural network classifier yield results with 81.82% sensitivity and 81.82% specificity. Also relative amplitude might be an efficient method in minimizing the effect of body composition on ECG amplitude based features without use of any information from other than ECG

  19. [Computer assisted long-term ECG analysis: method and clinical importance (author's transl)].

    PubMed

    Weber, H; Joskowicz, G; Glogar, D; Steinbach, K

    1982-01-01

    The basic principle of computer assisted analysis of Holter recordings is to store the whole ECG after data reduction and AD conversion in digitized form on random access medium like magnetic disks. In "Multipass Scanning" the linear segmentation techniques leads to highly reproducible ECG-data, which were analysed during multiple passes under continuous operator control. The field of clinical applications of such a highly sophisticated method reaches from supraventricular over ventricular to symptomatic arrhythmias. In combination with ECG-telefon-telemetry computer assisted LT-ECG analysis could be used in more than 75% of the patients successfully. The clinical expectations during routine could be fulfilled in more than 75%. Commonly a detailed numerical or graphical description of clinical relevant arrhythmias were necessary in the demand of the routine. So computer assisted LT-ECG analysis is not only a tool for research, but also valuable in the clinical routine.

  20. 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.

  1. Capacitive ECG recording and beat-to-beat interval estimation after major cardiac event.

    PubMed

    Leicht, Lennart; Skobel, Erik; Mathissen, Marcel; Leonhardt, Steffen; Weyer, Soren; Wartzek, Tobias; Reith, Sebastian; Mohler, Werner; Teichmann, Daniel

    2015-08-01

    Today, heart diseases are the most common cause of death in the U.S.. Due to improved healthcare, more and more patients survive a major cardiac event, e.g. a heart attack. However, participation in everyday activity (e.g. driving a car) can be impaired afterwards. Patients might benefit from heart activity monitoring while driving using a capacitive ECG (cECG). However, it is unknown whether cECG is an appropriate monitoring tool for such patients. In this work, first results from a study including 10 patients having survived at least one major cardiac event are presented. It is shown that cECG can be used to diagnose heart rhythm deviations and estimate beat-to-beat intervals similar to conventional ECG. PMID:26738055

  2. The Abnormal vs. Normal ECG Classification Based on Key Features and Statistical Learning

    NASA Astrophysics Data System (ADS)

    Dong, Jun; Tong, Jia-Fei; Liu, Xia

    As cardiovascular diseases appear frequently in modern society, the medicine and health system should be adjusted to meet the new requirements. Chinese government has planned to establish basic community medical insurance system (BCMIS) before 2020, where remote medical service is one of core issues. Therefore, we have developed the "remote network hospital system" which includes data server and diagnosis terminal by the aid of wireless detector to sample ECG. To improve the efficiency of ECG processing, in this paper, abnormal vs. normal ECG classification approach based on key features and statistical learning is presented, and the results are analyzed. Large amount of normal ECG could be filtered by computer automatically and abnormal ECG is left to be diagnosed specially by physicians.

  3. 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

  4. P and T wave detection on multichannel ECG using FRI.

    PubMed

    Nair, Amrish; Marziliano, Pina

    2014-01-01

    This paper proposes a new method for detecting P and T waves in multilead ECG based on the Finite Rate of Innovation(FRI) technique [8]. A simple QRS detection scheme will be presented followed by a novel P and T wave detection algorithm. The novelty here is the modelling of the P and T wave using a Gaussian kernel. Using a 2D wavelet decomposition, the approximation coefficients are windowed based on the QRS locations. The FRI method is then used to identify the Gaussian distribution present in the window which will in turn provide the locations of the P and T wave. This method was tested on more than an hour of clean and noisy data and shows good performance in the noisy case. PMID:25570440

  5. Personalized USB Biosensor Module for Effective ECG Monitoring.

    PubMed

    Sladojević, Srdjan; Arsenović, Marko; Lončar-Turukalo, Tatjana; Sladojević, Miroslava; Ćulibrk, Dubravko

    2016-01-01

    The burden of chronic disease and associated disability present a major threat to financial sustainability of healthcare delivery systems. The need for cost-effective early diagnosis and disease prevention is evident driving the development of personalized home health solutions. The proposed solution presents an easy to use ECG monitoring system. The core hardware component is a biosensor dongle with sensing probes at one end, and micro USB interface at the other end, offering reliable and unobtrusive sensing, preprocessing and storage. An additional component is a smart phone, providing both the biosensor's power supply and an intuitive user application for the real-time data reading. The system usage is simplified, with innovative solutions offering plug and play functionality avoiding additional driver installation. Personalized needs could be met with different sensor combinations enabling adequate monitoring in chronic disease, during physical activity and in the rehabilitation process. PMID:27225580

  6. 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).

  7. [ECG indices in dogs after inhalation of 239Pu].

    PubMed

    Karpova, V N

    1985-11-01

    Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs.

  8. Prolonged QRS Duration on the Resting ECG is Associated with Sudden Death Risk in Coronary Disease, Independent of Prolonged Ventricular Repolarization

    PubMed Central

    Teodorescu, C; Reinier, K; Uy-Evanado, A; Navarro, J; Mariani, R; Gunson, K; Jui, J; Chugh, SS

    2011-01-01

    Background Abnormalities of ventricular repolarization as well as depolarization have been associated with increased risk of ventricular arrhythmias. Objective We evaluated the relative contribution of these predictors to risk of sudden cardiac death (SCD) among patients with coronary artery disease (CAD). Methods In the ongoing Oregon Sudden Unexpected Death Study (Oregon SUDS), adult residents of Portland, OR metropolitan area (population ~1 million) who suffered SCD were identified prospectively (2002-2007). Of these, we analyzed the subgroup of SCDs that had a resting 12-lead ECG prior to SCD and also had associated CAD. Comparisons were conducted with a control group of subjects with known CAD, but no history of SCD from the same geographic region. Corrected QT interval (QTc), JT interval (JTc), QRS duration (QRSd) and other parameters were measured from ECG prior and unrelated to SCD. Analysis of LV function was limited to those subjects that had echocardiography performed prior to and remote from SCD. Results A total of 642 SCD cases (71±13 yrs, 62% male) were compared to 450 controls (66±12 yrs, 64% male). SCD cases had significantly longer QRSd (102±25 vs. 97±20 ms, p=0.0008) as well as JTc (348±44 vs. 339±34 ms, p=0.0006) vs. controls. In cases with prolonged QRSd, 38% had severe LV systolic dysfunction (LVSD) and 62% had normal, mild or moderately decreased LV systolic function. In a multivariable model, QRSd, JTc, age and severe LVSD were independent predictors. There was minimal overlap between prolonged QRSd and JTc in both case and control groups (3% and 4%, respectively). Conclusions Prolonged QRSd, JTc and severe LVSD had independent contributions to risk of SCD in coronary disease, in this community-based setting. PMID:21699869

  9. A Review of Fetal ECG Signal Processing; Issues and Promising Directions

    PubMed Central

    Sameni, Reza; Clifford, Gari D.

    2010-01-01

    The field of electrocardiography has been in existence for over a century, yet despite significant advances in adult clinical electrocardiography, signal processing techniques and fast digital processors, the analysis of fetal ECGs is still in its infancy. This is, partly due to a lack of availability of gold standard databases, partly due to the relatively low signal-to-noise ratio of the fetal ECG compared to the maternal ECG (caused by the various media between the fetal heart and the measuring electrodes, and the fact that the fetal heart is simply smaller), and in part, due to the less complete clinical knowledge concerning fetal cardiac function and development. In this paper we review a range of promising recording and signal processing techniques for fetal ECG analysis that have been developed over the last forty years, and discuss both their shortcomings and advantages. Before doing so, however, we review fetal cardiac development, and the etiology of the fetal ECG. A selection of relevant models for the fetal/maternal ECG mixture is also discussed. In light of current understanding of the fetal ECG, we then attempt to justify recommendations for promising future directions in signal processing, and database creation. PMID:21614148

  10. Compressed ECG biometric: a fast, secured and efficient method for identification of CVD patient.

    PubMed

    Sufi, Fahim; Khalil, Ibrahim; Mahmood, Abdun

    2011-12-01

    Adoption of compression technology is often required for wireless cardiovascular monitoring, due to the enormous size of Electrocardiography (ECG) signal and limited bandwidth of Internet. However, compressed ECG must be decompressed before performing human identification using present research on ECG based biometric techniques. This additional step of decompression creates a significant processing delay for identification task. This becomes an obvious burden on a system, if this needs to be done for a trillion of compressed ECG per hour by the hospital. Even though the hospital might be able to come up with an expensive infrastructure to tame the exuberant processing, for small intermediate nodes in a multihop network identification preceded by decompression is confronting. In this paper, we report a technique by which a person can be identified directly from his / her compressed ECG. This technique completely obviates the step of decompression and therefore upholds biometric identification less intimidating for the smaller nodes in a multihop network. The biometric template created by this new technique is lower in size compared to the existing ECG based biometrics as well as other forms of biometrics like face, finger, retina etc. (up to 8302 times lower than face template and 9 times lower than existing ECG based biometric template). Lower size of the template substantially reduces the one-to-many matching time for biometric recognition, resulting in a faster biometric authentication mechanism. PMID:20703779

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

    PubMed

    Fong, Ee-May; Chung, Wan-Young

    2015-08-05

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

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

    PubMed Central

    Fong, Ee-May; Chung, Wan-Young

    2015-01-01

    A capacitive electrocardiography (cECG) technique using a non-invasive ECG measuring technology that does not require direct contact between the sensor and the skin has attracted much interest. The system encounters several challenges when the sensor electrode and subject’s skin are weakly coupled. Because there is no direct physical contact between the subject and any grounding point, there is no discharge path for the built-up electrostatic charge. Subsequently, the electrostatic charge build-up can temporarily contaminate the ECG signal from being clearly visible; a stabilization period (3–15 min) is required for the measurement of a clean, stable ECG signal at low humidity levels (below 55% relative humidity). Therefore, to obtain a clear ECG signal without noise and to reduce the ECG signal stabilization time to within 2 min in a dry ambient environment, we have developed a fabric electrode with embedded polymer (FEEP). The designed hygroscopic FEEP has an embedded superabsorbent polymer layer. The principle of FEEP as a conductive electrode is to provide humidity to the capacitive coupling to ensure strong coupling and to allow for the measurement of a stable, clear biomedical signal. The evaluation results show that hygroscopic FEEP is capable of rapidly measuring high-accuracy ECG signals with a higher SNR ratio. PMID:26251913

  13. 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.

  14. 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

  15. 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

  16. Diagnostic quality of time-averaged ECG-gated CT data

    NASA Astrophysics Data System (ADS)

    Klein, Almar; Oostveen, Luuk J.; Greuter, Marcel J. W.; Hoogeveen, Yvonne; Schultze Kool, Leo J.; Slump, Cornelis H.; Renema, W. Klaas Jan

    2009-02-01

    Purpose: ECG-gated CTA allows visualization of the aneurysm and stentgraft during the different phases of the cardiac cycle, although with a lower SNR per cardiac phase than without ECG gating using the same dose. In our institution, abdominal aortic aneurysm (AAA) is evaluated using non-ECG-gated CTA. Some common CT scanners cannot reconstruct a non-gated volume from ECG-gated acquired data. In order to obtain the same diagnostic image quality, we propose offline temporal averaging of the ECG-gated data. This process, though straightforward, is fundamentally different from taking a non-gated scan, and its result will certainly differ as well. The purpose of this study is to quantitatively investigate how good off-line averaging approximates a non-gated scan. Method: Non-gated and ECG-gated CT scans have been performed on a phantom (Catphan 500). Afterwards the phases of the ECG-gated CTA data were averaged to create a third dataset. The three sets are compared with respect to noise properties (NPS) and frequency response (MTF). To study motion artifacts identical scans were acquired on a programmable dynamic phantom. Results and Conclusions: The experiments show that the spatial frequency content is not affected by the averaging process. The minor differences observed for the noise properties and motion artifacts are in favor of the averaged data. Therefore the averaged ECG-gated phases can be used for diagnosis. This enables the use of ECG-gating for research on stentgrafts in AAA, without impairing clinical patient care.

  17. 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.

  18. Real-time ECG emulation: a multiple dipole model for electrocardiography simulation.

    PubMed

    Abkai, Ciamak; Hesser, Jürgen

    2009-01-01

    A new model for describing electrocardiography (ECG) is presented, which is based on multiple dipoles compared to standard single dipole approaches in vector electrocardiography. The multiple dipole parameters are derived from real data (e.g. four dipoles from 12-channel ECG) by solving the backward problem of ECG numerically. Results are transformed to a waveform description based on Gaussian mixture for every dimension of each dipole. These compact parameterized descriptors are used for a very realistic real-time simulation applying the forward solution of the proposed model.

  19. Early and prolonged ECG alterations resembling a myocardial injury after severe amitriptyline poisoning.

    PubMed

    Berlot, G; Vergolini, A; Calderan, C

    2010-01-01

    Evidence of cardiovascular toxicity is present in the majority of tricyclic antidepressant overdoses. We report the case of a 63-year-old woman admitted to our department with a severe amitriptyline poisoning. The ECG at admission showed a pattern mimicking an acute anteroseptal subepicardial infarction. This pattern persisted for 11 days. Myocardial enzymes and echocardiographic findings never confirmed an ischemic event. At discharge, the ECG returned normal without cardiac or neurologic sequelae. Our experience suggest that after severe tricyclic antidepressant ingestion, ECG alterations resembling myocardial injury may occur early and last for a longer period than previously reported.

  20. Evaluation of novel ECG signal processing on quantification of transient ischemia and baseline wander suppression.

    PubMed

    Kostic, Marko N; Fakhar, Sina; Foxall, Tom; Drakulic, Budimir S; Krucoff, Mitchell W

    2007-01-01

    The performance assessment of a novel ECG signal processing technology in Fidelity 100 (test) and four modern ECG systems (controls) was conducted. A quantitative evaluation for one control and a test system was done by simultaneous recordings on 54 patients undergoing percutaneous coronary intervention (PCI) and on a biological reference signal from an ECG simulator. A qualitative performance of baseline wander suppression was done on all five systems. The results showed that the Fidelity 100 system provided excellent detection and quantification of transient ischemia and baseline wander suppression.

  1. 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

  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. Check your biosignals here: a new dataset for off-the-person ECG biometrics.

    PubMed

    da Silva, Hugo Plácido; Lourenço, André; Fred, Ana; Raposo, Nuno; Aires-de-Sousa, Marta

    2014-02-01

    The Check Your Biosignals Here initiative (CYBHi) was developed as a way of creating a dataset and consistently repeatable acquisition framework, to further extend research in electrocardiographic (ECG) biometrics. In particular, our work targets the novel trend towards off-the-person data acquisition, which opens a broad new set of challenges and opportunities both for research and industry. While datasets with ECG signals collected using medical grade equipment at the chest can be easily found, for off-the-person ECG data the solution is generally for each team to collect their own corpus at considerable expense of resources. In this paper we describe the context, experimental considerations, methods, and preliminary findings of two public datasets created by our team, one for short-term and another for long-term assessment, with ECG data collected at the hand palms and fingers.

  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. CinC Challenge 2013: comparing three algorithms to extract fetal ECG

    NASA Astrophysics Data System (ADS)

    Loja, Juan; Velecela, Esteban; Palacio-Baus, Kenneth; Astudillo, Darwin; Medina, Rubén.; Wong, Sara

    2015-12-01

    This paper reports a comparison between three fetal ECG (fECG) detectors developed during the CinC 2013 challenge for fECG detection. Algorithm A1 is based on Independent Component Analysis, A2 is based on fECG detection of RS Slope and A3 is based on Expectation-Weighted Estimation of Fiducial Points. The proposed methodology was validated using the annotated database available for the challenge. Each detector was characterized in terms of its performance by using measures of sensitivity, (Se), positive predictive value (P+) and delay time (td). Additionally, the database was contaminated with white noise for two SNR conditions. Decision fusion was tested considering the most common types of combination of detectors. Results show that the decision fusion of A1 and A2 improves fQRS detection, maintaining high Se and P+ even under low SNR conditions without a significant td increase.

  6. Compression and Encryption of ECG Signal Using Wavelet and Chaotically Huffman Code in Telemedicine Application.

    PubMed

    Raeiatibanadkooki, Mahsa; Quchani, Saeed Rahati; KhalilZade, MohammadMahdi; Bahaadinbeigy, Kambiz

    2016-03-01

    In mobile health care monitoring, compression is an essential tool for solving storage and transmission problems. The important issue is able to recover the original signal from the compressed signal. The main purpose of this paper is compressing the ECG signal with no loss of essential data and also encrypting the signal to keep it confidential from everyone, except for physicians. In this paper, mobile processors are used and there is no need for any computers to serve this purpose. After initial preprocessing such as removal of the baseline noise, Gaussian noise, peak detection and determination of heart rate, the ECG signal is compressed. In compression stage, after 3 steps of wavelet transform (db04), thresholding techniques are used. Then, Huffman coding with chaos for compression and encryption of the ECG signal are used. The compression rates of proposed algorithm is 97.72 %. Then, the ECG signals are sent to a telemedicine center to acquire specialist diagnosis by TCP/IP protocol.

  7. A PD control-based QRS detection algorithm for wearable ECG applications.

    PubMed

    Choi, Changmok; Kim, Younho; Shin, Kunsoo

    2012-01-01

    We present a QRS detection algorithm for wearable ECG applications using a proportional-derivative (PD) control. ECG data of arrhythmia have irregular intervals and magnitudes of QRS waves that impede correct QRS detection. To resolve the problem, PD control is applied to avoid missing a small QRS wave followed from a large QRS wave and to avoid falsely detecting noise as QRS waves when an interval between two adjacent QRS waves is large (e.g. bradycardia, pause, and arioventricular block). ECG data was obtained from 78 patients with various cardiovascular diseases and tested for the performance evaluation of the proposed algorithm. The overall sensitivity and positive predictive value were 99.28% and 99.26%, respectively. The proposed algorithm has low computational complexity, so that it can be suitable to apply mobile ECG monitoring system in real time. PMID:23367208

  8. 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.

  9. Misinterpretation of the mouse ECG: ‘musing the waves of Mus musculus’

    PubMed Central

    Boukens, Bastiaan J; Rivaud, Mathilde R; Rentschler, Stacey; Coronel, Ruben

    2014-01-01

    The ECG is a primary diagnostic tool in patients suffering from heart disease, underscoring the importance of understanding factors contributing to normal and abnormal electrical patterns. Over the past few decades, transgenic mouse models have been increasingly used to study pathophysiological mechanisms of human heart diseases. In order to allow extrapolation of insights gained from murine models to the human condition, knowledge of the similarities and differences between the mouse and human ECG is of crucial importance. In this review, we briefly discuss the physiological mechanisms underlying differences between the baseline ECG of humans and mice, and provide a framework for understanding how these inherent differences are relevant to the interpretation of the mouse ECG during pathology and to the translation of the results from the mouse to man. PMID:25260630

  10. Unobtrusive monitoring of ECG-derived features during daily smartphone use.

    PubMed

    Kwon, Sungjun; Kang, Seungwoo; Lee, Youngki; Yoo, Chungkuk; Park, Kwangsuk

    2014-01-01

    Heart rate variability (HRV) is known to be one of the representative ECG-derived features that are useful for diverse pervasive healthcare applications. The advancement in daily physiological monitoring technology is enabling monitoring of HRV in people's everyday lives. In this study, we evaluate the feasibility of measuring ECG-derived features such as HRV, only using the smartphone-integrated ECG sensors system named Sinabro. We conducted the evaluation with 13 subjects in five predetermined smartphone use cases. The result shows the potential that the smartphone-based sensing system can support daily monitoring of ECG-derived features; The average errors of HRV over all participants ranged from 1.65% to 5.83% (SD: 2.54~10.87) for five use cases. Also, all of individual HRV parameters showed less than 5% of average errors for the three reliable cases.

  11. Design and implementation of a 3-lead ECG wireless remote monitoring system

    NASA Astrophysics Data System (ADS)

    Zhang, Shi; Jia, Xiaonan; Shang, Shuai

    2006-11-01

    Cardiovascular disease is one of the main diseases that menaces human health. It is necessary to monitor the patient's real-time electrocardiograph (ECG) for a long time to realize diagnosis and salvage. Remote ECG monitoring system is the solution. This paper introduces the design and implement of a 3-lead ECG wireless remote monitoring system. It collects, stores and transmits user's ECG which can be received by hospital and diagnosed by doctors. The development of the whole system contains three parts, the hardware and embedded software implementation of MONITOR, software of the MONITORING CENTER, and the routing software of NETWORK CENTER. According to the clinic experimentation, this system has high reliability and utility. There will be great social and economic benefit if this system is put into use.

  12. 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

  13. Motion artifact removal algorithm by ICA for e-bra: a women ECG measurement system

    NASA Astrophysics Data System (ADS)

    Kwon, Hyeokjun; Oh, Sechang; Varadan, Vijay K.

    2013-04-01

    Wearable ECG(ElectroCardioGram) measurement systems have increasingly been developing for people who suffer from CVD(CardioVascular Disease) and have very active lifestyles. Especially, in the case of female CVD patients, several abnormal CVD symptoms are accompanied with CVDs. Therefore, monitoring women's ECG signal is a significant diagnostic method to prevent from sudden heart attack. The E-bra ECG measurement system from our previous work provides more convenient option for women than Holter monitor system. The e-bra system was developed with a motion artifact removal algorithm by using an adaptive filter with LMS(least mean square) and a wandering noise baseline detection algorithm. In this paper, ICA(independent component analysis) algorithms are suggested to remove motion artifact factor for the e-bra system. Firstly, the ICA algorithms are developed with two kinds of statistical theories: Kurtosis, Endropy and evaluated by performing simulations with a ECG signal created by sgolayfilt function of MATLAB, a noise signal including 0.4Hz, 1.1Hz and 1.9Hz, and a weighed vector W estimated by kurtosis or entropy. A correlation value is shown as the degree of similarity between the created ECG signal and the estimated new ECG signal. In the real time E-Bra system, two pseudo signals are extracted by multiplying with a random weighted vector W, the measured ECG signal from E-bra system, and the noise component signal by noise extraction algorithm from our previous work. The suggested ICA algorithm basing on kurtosis or entropy is used to estimate the new ECG signal Y without noise component.

  14. P wave detection and delineation in the ECG based on the phase free stationary wavelet transform and using intracardiac atrial electrograms as reference.

    PubMed

    Lenis, Gustavo; Pilia, Nicolas; Oesterlein, Tobias; Luik, Armin; Schmitt, Claus; Dössel, Olaf

    2016-02-01

    Robust and exact automatic P wave detection and delineation in the electrocardiogram (ECG) is still an interesting but challenging research topic. The early prognosis of cardiac afflictions such as atrial fibrillation and the response of a patient to a given treatment is believed to improve if the P wave is carefully analyzed during sinus rhythm. Manual annotation of the signals is a tedious and subjective task. Its correctness depends on the experience of the annotator, quality of the signal, and ECG lead. In this work, we present a wavelet-based algorithm to detect and delineate P waves in individual ECG leads. We evaluated a large group of commonly used wavelets and frequency bands (wavelet levels) and introduced a special phase free wavelet transformation. The local extrema of the transformed signals are directly related to the delineating points of the P wave. First, the algorithm was studied using synthetic signals. Then, the optimal parameter configuration was found using intracardiac electrograms and surface ECGs measured simultaneously. The reverse biorthogonal wavelet 3.3 was found to be optimal for this application. In the end, the method was validated using the QT database from PhysioNet. We showed that the algorithm works more accurately and more robustly than other methods presented in literature. The validation study delivered an average delineation error of the P wave onset of -0.32±12.41 ms when compared to manual annotations. In conclusion, the algorithm is suitable for handling varying P wave shapes and low signal-to-noise ratios. PMID:26136298

  15. P wave detection and delineation in the ECG based on the phase free stationary wavelet transform and using intracardiac atrial electrograms as reference.

    PubMed

    Lenis, Gustavo; Pilia, Nicolas; Oesterlein, Tobias; Luik, Armin; Schmitt, Claus; Dössel, Olaf

    2016-02-01

    Robust and exact automatic P wave detection and delineation in the electrocardiogram (ECG) is still an interesting but challenging research topic. The early prognosis of cardiac afflictions such as atrial fibrillation and the response of a patient to a given treatment is believed to improve if the P wave is carefully analyzed during sinus rhythm. Manual annotation of the signals is a tedious and subjective task. Its correctness depends on the experience of the annotator, quality of the signal, and ECG lead. In this work, we present a wavelet-based algorithm to detect and delineate P waves in individual ECG leads. We evaluated a large group of commonly used wavelets and frequency bands (wavelet levels) and introduced a special phase free wavelet transformation. The local extrema of the transformed signals are directly related to the delineating points of the P wave. First, the algorithm was studied using synthetic signals. Then, the optimal parameter configuration was found using intracardiac electrograms and surface ECGs measured simultaneously. The reverse biorthogonal wavelet 3.3 was found to be optimal for this application. In the end, the method was validated using the QT database from PhysioNet. We showed that the algorithm works more accurately and more robustly than other methods presented in literature. The validation study delivered an average delineation error of the P wave onset of -0.32±12.41 ms when compared to manual annotations. In conclusion, the algorithm is suitable for handling varying P wave shapes and low signal-to-noise ratios.

  16. Sleep apnea classification using ECG-signal wavelet-PCA features.

    PubMed

    Rachim, Vega Pradana; Li, Gang; Chung, Wan-Young

    2014-01-01

    Sleep apnea is often diagnosed using an overnight sleep test called a polysomnography (PSG). Unfortunately, though it is the gold standard of sleep disorder diagnosis, a PSG is time consuming, inconvenient, and expensive. Many researchers have tried to ameliorate this problem by developing other reliable methods, such as using electrocardiography (ECG) as an observed signal source. Respiratory rate interval, ECG-derived respiration, and heart rate variability analysis have been studied recently as a means of detecting apnea events using ECG during normal sleep, but these methods have performance weaknesses. Thus, the aim of this study is to classify the subject into normal- or apnea-subject based on their single-channel ECG measurement in regular sleep. In this proposed study, ECG is decomposed into five levels using wavelet decomposition for the initial processing to determine the detail coefficients (D3-D5) of the signal. Approximately 15 features were extracted from every minute of ECG. Principal component analysis and a support vector machine are used for feature dimension reduction and classification, respectively. According to classification that been done from a data set consisting of thirty-five patients, the proposed minute-to-minute classifier specificity, sensitivity, and subject-based classification accuracy are 95.20%, 92.65%, and 94.3%, respectively. Furthermore, the proposed system can be used as a basis for future development of sleep apnea screening tools. PMID:25226993

  17. CNT/PDMS composite flexible dry electrodes for long-term ECG monitoring.

    PubMed

    Jung, Ha-Chul; Moon, Jin-Hee; Baek, Dong-Hyun; Lee, Jae-Hee; Choi, Yoon-Young; Hong, Joung-Sook; Lee, Sang-Hoon

    2012-05-01

    We fabricated a carbon nanotube (CNT)/ polydimethylsiloxane (PDMS) composite-based dry ECG electrode that can be readily connected to conventional ECG devices, and showed its long-term wearable monitoring capability and robustness to motion and sweat. While the dispersion of CNTs in PDMS is challenging, we optimized the process to disperse untreated CNTs within PDMS by mechanical force only. The electrical and mechanical characteristics of the CNT/PDMS electrode were tested according to the concentration of CNTs and its thickness. The performances of ECG electrodes were evaluated by using 36 types of electrodes which were fabricated with different concentrations of CNTs, and with a differing diameter and thickness. The ECG signals were obtained by using electrodes of diverse sizes to observe the effects of motion and sweat, and the proposed electrode was shown to be robust to both factors. The CNT concentration and diameter of the electrodes were critical parameters in obtaining high-quality ECG signals. The electrode was shown to be biocompatible from the cytotoxicity test. A seven-day continuous wearability test showed that the quality of the ECG signal did not degrade over time, and skin reactions such as itching or erythema were not observed. This electrode could be used for the long-term measurement of other electrical biosignals for ubiquitous health monitoring including EMG, EEG, and ERG.

  18. An efficient unsupervised fetal QRS complex detection from abdominal maternal ECG.

    PubMed

    Varanini, M; Tartarisco, G; Billeci, L; Macerata, A; Pioggia, G; Balocchi, R

    2014-08-01

    Non-invasive fetal heart rate is of great relevance in clinical practice to monitor fetal health state during pregnancy. To date, however, despite significant advances in the field of electrocardiography, the analysis of abdominal fetal ECG is considered a challenging problem for biomedical and signal processing communities. This is mainly due to the low signal-to-noise ratio of fetal ECG and difficulties in cancellation of maternal QRS complexes, motion and electromyographic artefacts. In this paper we present an efficient unsupervised algorithm for fetal QRS complex detection from abdominal multichannel signal recordings combining ICA and maternal ECG cancelling, which outperforms each single method. The signal is first pre-processed to remove impulsive artefacts, baseline wandering and power line interference. The following steps are then applied: maternal ECG extraction through independent component analysis (ICA); maternal QRS detection; maternal ECG cancelling through weighted singular value decomposition; enhancing of fetal ECG through ICA and fetal QRS detection. We participated in the Physionet/Computing in Cardiology Challenge 2013, obtaining the top official scores of the challenge (among 53 teams of participants) of event 1 and event 2 concerning fetal heart rate and fetal interbeat intervals estimation section. The developed algorithms are released as open-source on the Physionet website.

  19. Real-time CHF detection from ECG signals using a novel discretization method.

    PubMed

    Orhan, Umut

    2013-10-01

    This study proposes a new method, equal frequency in amplitude and equal width in time (EFiA-EWiT) discretization, to discriminate between congestive heart failure (CHF) and normal sinus rhythm (NSR) patterns in ECG signals. The ECG unit pattern concept was introduced to represent the standard RR interval, and our method extracted certain features from the unit patterns to classify by a primitive classifier. The proposed method was tested on two classification experiments by using ECG records in Physiobank databases and the results were compared to those from several previous studies. In the first experiment, an off-line classification was performed with unit patterns selected from long ECG segments. The method was also used to detect CHF by real-time ECG waveform analysis. In addition to demonstrating the success of the proposed method, the results showed that some unit patterns in a long ECG segment from a heart patient were more suggestive of disease than the others. These results indicate that the proposed approach merits additional research.

  20. Wavelet-Based ECG Steganography for Protecting Patient Confidential Information in Point-of-Care Systems.

    PubMed

    Ibaida, Ayman; Khalil, Ibrahim

    2013-12-01

    With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as point-of-care (PoC) applications in hospitals around the world. Therefore, huge amount of ECG signal collected by body sensor networks from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level, etc., and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data are being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this paper, a wavelet-based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest. To evaluate the effectiveness of the proposed technique on the ECG signal, two distortion measurement metrics have been used: the percentage residual difference and the wavelet weighted PRD. It is found that the proposed technique provides high-security protection for patients data with low (less than 1%) distortion and ECG data remain diagnosable after watermarking (i.e., hiding patient confidential data) and as well as after watermarks (i.e., hidden data) are removed from the watermarked data.

  1. Low-cost compact ECG with graphic LCD and phonocardiogram system design.

    PubMed

    Kara, Sadik; Kemaloğlu, Semra; Kirbaş, Samil

    2006-06-01

    Till today, many different ECG devices are made in developing countries. In this study, low cost, small size, portable LCD screen ECG device, and phonocardiograph were designed. With designed system, heart sounds that take synchronously with ECG signal are heard as sensitive. Improved system consist three units; Unit 1, ECG circuit, filter and amplifier structure. Unit 2, heart sound acquisition circuit. Unit 3, microcontroller, graphic LCD and ECG signal sending unit to computer. Our system can be used easily in different departments of the hospital, health institution and clinics, village clinic and also in houses because of its small size structure and other benefits. In this way, it is possible that to see ECG signal and hear heart sounds as synchronously and sensitively. In conclusion, heart sounds are heard on the part of both doctor and patient because sounds are given to environment with a tiny speaker. Thus, the patient knows and hears heart sounds him/herself and is acquainted by doctor about healthy condition. PMID:16848133

  2. 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.

  3. Low-cost compact ECG with graphic LCD and phonocardiogram system design.

    PubMed

    Kara, Sadik; Kemaloğlu, Semra; Kirbaş, Samil

    2006-06-01

    Till today, many different ECG devices are made in developing countries. In this study, low cost, small size, portable LCD screen ECG device, and phonocardiograph were designed. With designed system, heart sounds that take synchronously with ECG signal are heard as sensitive. Improved system consist three units; Unit 1, ECG circuit, filter and amplifier structure. Unit 2, heart sound acquisition circuit. Unit 3, microcontroller, graphic LCD and ECG signal sending unit to computer. Our system can be used easily in different departments of the hospital, health institution and clinics, village clinic and also in houses because of its small size structure and other benefits. In this way, it is possible that to see ECG signal and hear heart sounds as synchronously and sensitively. In conclusion, heart sounds are heard on the part of both doctor and patient because sounds are given to environment with a tiny speaker. Thus, the patient knows and hears heart sounds him/herself and is acquainted by doctor about healthy condition.

  4. 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

  5. Ambulatory respiratory rate detection using ECG and a triaxial accelerometer.

    PubMed

    Chan, Alexander M; Ferdosi, Nima; Narasimhan, Ravi

    2013-01-01

    Continuous monitoring of respiratory rate in ambulatory conditions has widespread applications for screening of respiratory diseases and remote patient monitoring. Unfortunately, minimally obtrusive techniques often suffer from low accuracy. In this paper, we describe an algorithm with low computational complexity for combining multiple respiratory measurements to estimate breathing rate from an unobtrusive chest patch sensor. Respiratory rates derived from the respiratory sinus arrhythmia (RSA) and modulation of the QRS amplitude of electrocardiography (ECG) are combined with a respiratory rate derived from tri-axial accelerometer data. The three respiration rates are combined by a weighted average using weights based on quality metrics for each signal. The algorithm was evaluated on 15 elderly subjects who performed spontaneous and metronome breathing as well as a variety of activities of daily living (ADLs). When compared to a reference device, the mean absolute error was 1.02 breaths per minute (BrPM) during metronome breathing, 1.67 BrPM during spontaneous breathing, and 2.03 BrPM during ADLs.

  6. Anomalous ECG downloads from semi-automatic external defibrillators.

    PubMed

    Calle, P A; Vanhaute, O; Ranhoff, J F; Buylaert, W A

    1998-08-01

    The coincidental print-out by two different Laerdal systems (subsequently called 'system A' and 'system B') of the same medical control module (MCM) for a Laerdal Heartstart 2000 semi-automatic external defibrillator (SAED) led to the discovery of three deficiencies in the information storage and printing processes. First, we noted that the impedance reported via system A was consistently higher. Second, we found the attachment of 'mysterious' ECG samples in the reports from system B, but not from system A. A third problem was the unpredictable (in)ability of system B to print out the information from the MCMs. Further investigations with help from the company suggested that the above-mentioned problems were caused by incompatibilities between the software in the different parts of equipment used (i.e. SAED devices, MCMs, printing systems and a computer program to store the information in a database). These observations demonstrate the need for strict medical supervision on all aspects of a SAED project, and for feed-back from clinicians to manufacturers. PMID:9863574

  7. Clinically accurate fetal ECG parameters acquired from maternal abdominal sensors

    PubMed Central

    CLIFFORD, Gari; SAMENI, Reza; WARD, Mr. Jay; ROBINSON, Julian; WOLFBERG, Adam J.

    2011-01-01

    OBJECTIVE To evaluate the accuracy of a novel system for measuring fetal heart rate and ST-segment changes using non-invasive electrodes on the maternal abdomen. STUDY DESIGN Fetal ECGs were recorded using abdominal sensors from 32 term laboring women who had a fetal scalp electrode (FSE) placed for a clinical indication. RESULTS Good quality data for FHR estimation was available in 91.2% of the FSE segments, and 89.9% of the abdominal electrode segments. The root mean square (RMS) error between the FHR data calculated by both methods over all processed segments was 0.36 beats per minute. ST deviation from the isoelectric point ranged from 0 to 14.2% of R-wave amplitude. The RMS error between the ST change calculated by both methods averaged over all processed segments was 3.2%. CONCLUSION FHR and ST change acquired from the maternal abdomen is highly accurate and on average is clinically indistinguishable from FHR and ST change calculated using FSE data. PMID:21514560

  8. ECG gated NMR-CT for cardiovascular diseases

    SciTech Connect

    Nishikawa, J.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.; Kawaguchi, H.; Mano, H.

    1984-01-01

    The authors applied NMR-CT to cardiac study with ECG gated technique to evaluate the left ventricular (LV) function and compared it with cardiovascular nuclear medicine study (NM). The NMR-CT machine has resistive air-core magnet with 0.15 Tesla. The saturation recovery image or inversion recovery image were obtained as 256 x 256 matrix and 15 mm in thickness. The study population was ten patients who were evaluated both by NMR image and by NM performed within one week interval. The heart muscle was able to be visualized without any contrast material nor radioisotopes in inversion recovery images, whereas saturation recovery images failed to separate heart muscle from blood pool. The wall motions of LV in both methods were well correlated except for inferior wall. The values of ejection fraction in NMR image were moderately low, but two modalities showed satisfactory correlation (r=0.85). The region of myocardial infarction was revealed as wall thinning and/or wall motion abnormality. It is still preliminary to draw a conclusion, however, it can be said that in the evaluation of LV function, method by NMR might be of equal value to those of NM. It can be certain that eventually gated NMR-CT will become more effective method for various aspects of cardiovascular evaluation.

  9. Electrocardiographic artefacts mimicking atrial tachycardia resulted in unnecessary diagnostic and therapeutic measures

    PubMed Central

    Sylvén, Christer

    2013-01-01

    Electrocardiographic (ECG) artefacts may closely simulate both supraventricular and ventricular tachycardias. We describe a case initially diagnosed as rapid atrial fibrillation, based on 12-lead surface ECG (especially the limb leads) and monitor tracing. The arrhythmia was resistant to beta blockers. Because of the at times apparently regular rhythm, an esophageal ECG recording was performed, and adenosine was administered. When the presumed atrial fibrillation terminated after sodium pentothal was administered while preparing for electrical cardioversion, the oesophageal ECG recordings and the ECGs during adenosine administration were reviewed. An ECG artefact diagnosis was suspected, and then confirmed, during relapse of the "arrhythmia," with simple palpation of the radial pulse and cardiac auscultation. PMID:23526333

  10. Electrocardiographic artefacts mimicking atrial tachycardia resulted in unnecessary diagnostic and therapeutic measures.

    PubMed

    Y-Hassan, Shams; Sylvén, Christer

    2013-03-01

    Electrocardiographic (ECG) artefacts may closely simulate both supraventricular and ventricular tachycardias. We describe a case initially diagnosed as rapid atrial fibrillation, based on 12-lead surface ECG (especially the limb leads) and monitor tracing. The arrhythmia was resistant to beta blockers. Because of the at times apparently regular rhythm, an esophageal ECG recording was performed, and adenosine was administered. When the presumed atrial fibrillation terminated after sodium pentothal was administered while preparing for electrical cardioversion, the oesophageal ECG recordings and the ECGs during adenosine administration were reviewed. An ECG artefact diagnosis was suspected, and then confirmed, during relapse of the "arrhythmia," with simple palpation of the radial pulse and cardiac auscultation.

  11. The chaos and order in human ECG under the influence of the external perturbations

    NASA Astrophysics Data System (ADS)

    Ragulskaya, Maria; Valeriy, Pipin

    The results of the many-year telecommunication heliomedical monitoring "Heliomed" show, that space weather and geophysical factor variations serve as a training factor for the adaptation-resistant member of the human population. Here we discuss the specific properties of the human ECG discovered in our experiment. The program "Heliomed" is carried out simultaneously at the different geographical areas that cover the different latitudes. The daily registered param-eters include: the psycho-emotional tests and the 1-st lead ECG, the arterial pressure, the variability cardiac contraction, the electric conduction of bioactive points on skin. The results time series compared with daily values of space weather and geomagnetic parameters. The analysis of ECG signal proceeds as follows. At first step we construct the ECG embedding into 3D phase space using the first 3 Principal Components of the ECG time series. Next, we divide ECG on the separate cycles using the maxima of the ECG's QRS complex. Then, we filter out the non-typical ECG beats by means of the Housdorff distance. Finally, we average the example of the ECG time series along the reference trajectory and study of the dynamical characteristics of the averaged ECG beat. It is found, that the ECG signal embeded in 3D phase space can be considered as a mix of a few states. At the rest, the occurrence of the primary ECG state compare to additional ones is about 8:2. The occurrence of the primary state increases after the stress. The main effect of the external perturbation is observed in structural change of the cardio-cycle and not in the variability of the R-R interval. The num-ber of none-typical cycles increase during an isolated magnetic storm. At the all monitoring centers participating experiment the same type of changes in the cardiac activity parameters is detected to go nearly simultaneously during an isolated magnetic storm. To understand the origin of the standard cardio-cycle changes we use the dynamical

  12. Construction of a Resting High Fidelity ECG "SuperScore" for Management and Screening of Heart Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Delgado, Reynolds; Poulin, Greg; Starc, Vito; Arenare, Brian; Rahman, M. A.

    2006-01-01

    Resting conventional ECG is notoriously insensitive for detecting coronary artery disease (CAD) and only nominally useful in screening for cardiomyopathy (CM). Similarly, conventional exercise stress test ECG is both time- and labor-consuming and its accuracy in identifying CAD is suboptimal for use in population screening. We retrospectively investigated the accuracy of several advanced resting electrocardiographic (ECG) parameters, both alone and in combination, for detecting CAD and cardiomyopathy (CM).

  13. 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.

  14. The emergency department ECG and immediately life-threatening complications in initially uncomplicated suspected myocardial ischemia.

    PubMed

    Zalenski, R J; Sloan, E P; Chen, E H; Hayden, R F; Gold, I W; Cooke, D

    1988-03-01

    The emergency physician's disposition of patients with suspected myocardial ischemia is currently debated; some physicians believe that a subgroup of patients can be managed safely outside the coronary care unit. Clinical predictors are needed in assessing the patient with suspected myocardial ischemia to help identify this subgroup. Through a retrospective cohort study, we investigated the value of the initial emergency department ECG in discriminating between chest pain patients with low and high risk for immediately life-threatening complications. Two hundred eleven initially uncomplicated consecutive coronary care unit admissions with suspected unstable angina or myocardial infarction were studied. Patient outcome, including the incidence of myocardial infarction, complications, and mechanical and pharmacologic interventions, was reviewed. Immediately life-threatening complications included ventricular fibrillation, ventricular tachycardia, shock, 2 degrees and 3 degrees block, and death. Mechanical interventions included electrocardioversion or defibrillation, endotracheal intubation, intra-aortic balloon pump, Swan-Ganz catheter, or pacemaker insertion. Pressors, antiarrhythmics, and vasodilators were the reviewed pharmacologic interventions. A positive ECG was defined by the presence of ST elevation or depression, T wave inversion, left ventricular hypertrophy, left bundle branch block, paced rhythm, or new Q waves. All other ECG interpretations were considered negative. Patients were divided into two groups based on this initial emergency physician ECG interpretation and their complication incidences compared. Of the 211 patients, 96 had a positive ECG; 115 had negative ECGs. Patients with positive ECGs were older, had a greater history and concurrent incidence of myocardial infarction, and more complications and intensive interventions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3345014

  15. 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.

  16. [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

  17. A Wearable Context-Aware ECG Monitoring System Integrated with Built-in Kinematic Sensors of the Smartphone

    PubMed Central

    Miao, Fen; Cheng, Yayu; He, Yi; He, Qingyun; Li, Ye

    2015-01-01

    Continuously monitoring the ECG signals over hours combined with activity status is very important for preventing cardiovascular diseases. A traditional ECG holter is often inconvenient to carry because it has many electrodes attached to the chest and because it is heavy. This work proposes a wearable, low power context-aware ECG monitoring system integrated built-in kinetic sensors of the smartphone with a self-designed ECG sensor. The wearable ECG sensor is comprised of a fully integrated analog front-end (AFE), a commercial micro control unit (MCU), a secure digital (SD) card, and a Bluetooth module. The whole sensor is very small with a size of only 58 × 50 × 10 mm for wearable monitoring application due to the AFE design, and the total power dissipation in a full round of ECG acquisition is only 12.5 mW. With the help of built-in kinetic sensors of the smartphone, the proposed system can compute and recognize user’s physical activity, and thus provide context-aware information for the continuous ECG monitoring. The experimental results demonstrated the performance of proposed system in improving diagnosis accuracy for arrhythmias and identifying the most common abnormal ECG patterns in different activities. In conclusion, we provide a wearable, accurate and energy-efficient system for long-term and context-aware ECG monitoring without any extra cost on kinetic sensor design but with the help of the widespread smartphone. PMID:25996508

  18. An integrated healthcare information system for end-to-end standardized exchange and homogeneous management of digital ECG formats.

    PubMed

    Trigo, Jesús Daniel; Martínez, Ignacio; Alesanco, Alvaro; Kollmann, Alexander; Escayola, Javier; Hayn, Dieter; Schreier, Günter; García, José

    2012-07-01

    This paper investigates the application of the enterprise information system (EIS) paradigm to standardized cardiovascular condition monitoring. There are many specifications in cardiology, particularly in the ECG standardization arena. The existence of ECG formats, however, does not guarantee the implementation of homogeneous, standardized solutions for ECG management. In fact, hospital management services need to cope with various ECG formats and, moreover, several different visualization applications. This heterogeneity hampers the normalization of integrated, standardized healthcare information systems, hence the need for finding an appropriate combination of ECG formats and a suitable EIS-based software architecture that enables standardized exchange and homogeneous management of ECG formats. Determining such a combination is one objective of this paper. The second aim is to design and develop the integrated healthcare information system that satisfies the requirements posed by the previous determination. The ECG formats selected include ISO/IEEE11073, Standard Communications Protocol for Computer-Assisted Electrocardiography, and an ECG ontology. The EIS-enabling techniques and technologies selected include web services, simple object access protocol, extensible markup language, or business process execution language. Such a selection ensures the standardized exchange of ECGs within, or across, healthcare information systems while providing modularity and accessibility.

  19. 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

  20. A Wearable Context-Aware ECG Monitoring System Integrated with Built-in Kinematic Sensors of the Smartphone.

    PubMed

    Miao, Fen; Cheng, Yayu; He, Yi; He, Qingyun; Li, Ye

    2015-05-19

    Continuously monitoring the ECG signals over hours combined with activity status is very important for preventing cardiovascular diseases. A traditional ECG holter is often inconvenient to carry because it has many electrodes attached to the chest and because it is heavy. This work proposes a wearable, low power context-aware ECG monitoring system integrated built-in kinetic sensors of the smartphone with a self-designed ECG sensor. The wearable ECG sensor is comprised of a fully integrated analog front-end (AFE), a commercial micro control unit (MCU), a secure digital (SD) card, and a Bluetooth module. The whole sensor is very small with a size of only 58 × 50 × 10 mm for wearable monitoring application due to the AFE design, and the total power dissipation in a full round of ECG acquisition is only 12.5 mW. With the help of built-in kinetic sensors of the smartphone, the proposed system can compute and recognize user's physical activity, and thus provide context-aware information for the continuous ECG monitoring. The experimental results demonstrated the performance of proposed system in improving diagnosis accuracy for arrhythmias and identifying the most common abnormal ECG patterns in different activities. In conclusion, we provide a wearable, accurate and energy-efficient system for long-term and context-aware ECG monitoring without any extra cost on kinetic sensor design but with the help of the widespread smartphone.

  1. [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.

  2. A Wearable Context-Aware ECG Monitoring System Integrated with Built-in Kinematic Sensors of the Smartphone.

    PubMed

    Miao, Fen; Cheng, Yayu; He, Yi; He, Qingyun; Li, Ye

    2015-01-01

    Continuously monitoring the ECG signals over hours combined with activity status is very important for preventing cardiovascular diseases. A traditional ECG holter is often inconvenient to carry because it has many electrodes attached to the chest and because it is heavy. This work proposes a wearable, low power context-aware ECG monitoring system integrated built-in kinetic sensors of the smartphone with a self-designed ECG sensor. The wearable ECG sensor is comprised of a fully integrated analog front-end (AFE), a commercial micro control unit (MCU), a secure digital (SD) card, and a Bluetooth module. The whole sensor is very small with a size of only 58 × 50 × 10 mm for wearable monitoring application due to the AFE design, and the total power dissipation in a full round of ECG acquisition is only 12.5 mW. With the help of built-in kinetic sensors of the smartphone, the proposed system can compute and recognize user's physical activity, and thus provide context-aware information for the continuous ECG monitoring. The experimental results demonstrated the performance of proposed system in improving diagnosis accuracy for arrhythmias and identifying the most common abnormal ECG patterns in different activities. In conclusion, we provide a wearable, accurate and energy-efficient system for long-term and context-aware ECG monitoring without any extra cost on kinetic sensor design but with the help of the widespread smartphone. PMID:25996508

  3. 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

  4. Use of frequency analysis on the ECG for the prognosis of low energy cardioversion treatment of atrial fibrillation.

    PubMed

    Diaz, J; Escalona, O; Glover, B M; Manoharan, G

    2009-01-01

    Electric cardioversion is the most effective therapy for restoring sinus rhythm in patient with atrial fibrillation (AF), however, there is not a guiding criteria for advising on when and in whom it will be successful. The objective of this study was to employ frequency analysis on the surface electrocardiogram (ECG) to predict the outcome of low energy internal cardioversion in patients with AF. Thirty nine patients with AF, for elective DC cardioversion were included in this study. One catheter was positioned in the right atrial appendage and another in the coronary sinus. A voltage step-up protocol (50-300 V) was used for patient cardioversion. Prior to shock delivery, residual atrial activity signal (RAAS) was derived from 60 seconds of surface ECG from defibrillator pads, by bandpass filtering and ventricular activity (QRST) cancellation. Dominant atrial fibrillatory frequency (DAFF) was estimated from the RAAS power spectrum as the dominant frequency within the 3-12 Hz band. DAFF was calculated from whole 60 seconds segment (DAFF_L) and from the finals 10 seconds segment (DAFF_S) of the RAAS. Lower DAFF_L and DAFF_S were found in successfully cardioverted patients than in those nonsuccessful ones, with energy < or =3 and < or =6 joules. Therapy result (employing 3J or less) was predicted in 35/39 (89.7%) patients with DAFF_L=5.40Hz, and DAFF_L was > or =5.75Hz in a 100% of noncardioverted patients. In conclusion, frequency analysis of the RAAS could be useful for predicting success of low energy internal cardioversion of patients with atrial fibrillation.

  5. Discrete wavelet transform and singular value decomposition based ECG steganography for secured patient information transmission.

    PubMed

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

    2014-10-01

    ECG Steganography provides secured transmission of secret information such as patient personal information through ECG signals. This paper proposes an approach that uses discrete wavelet transform to decompose signals and singular value decomposition (SVD) to embed the secret information into the decomposed ECG signal. The novelty of the proposed method is to embed the watermark using SVD into the two dimensional (2D) ECG image. The embedding of secret information in a selected sub band of the decomposed ECG is achieved by replacing the singular values of the decomposed cover image by the singular values of the secret data. The performance assessment of the proposed approach allows understanding the suitable sub-band to hide secret data and the signal degradation that will affect diagnosability. Performance is measured using metrics like Kullback-Leibler divergence (KL), percentage residual difference (PRD), peak signal to noise ratio (PSNR) and bit error rate (BER). A dynamic location selection approach for embedding the singular values is also discussed. The proposed approach is demonstrated on a MIT-BIH database and the observations validate that HH is the ideal sub-band to hide data. It is also observed that the signal degradation (less than 0.6%) is very less in the proposed approach even with the secret data being as large as the sub band size. So, it does not affect the diagnosability and is reliable to transmit patient information. PMID:25187409

  6. Revisiting QRS Detection Methodologies for Portable, Wearable, Battery-Operated, and Wireless ECG Systems

    PubMed Central

    Elgendi, Mohamed; Eskofier, Björn; Dokos, Socrates; Abbott, Derek

    2014-01-01

    Cardiovascular diseases are the number one cause of death worldwide. Currently, portable battery-operated systems such as mobile phones with wireless ECG sensors have the potential to be used in continuous cardiac function assessment that can be easily integrated into daily life. These portable point-of-care diagnostic systems can therefore help unveil and treat cardiovascular diseases. The basis for ECG analysis is a robust detection of the prominent QRS complex, as well as other ECG signal characteristics. However, it is not clear from the literature which ECG analysis algorithms are suited for an implementation on a mobile device. We investigate current QRS detection algorithms based on three assessment criteria: 1) robustness to noise, 2) parameter choice, and 3) numerical efficiency, in order to target a universal fast-robust detector. Furthermore, existing QRS detection algorithms may provide an acceptable solution only on small segments of ECG signals, within a certain amplitude range, or amid particular types of arrhythmia and/or noise. These issues are discussed in the context of a comparison with the most conventional algorithms, followed by future recommendations for developing reliable QRS detection schemes suitable for implementation on battery-operated mobile devices. PMID:24409290

  7. Subject identification via ECG fiducial-based systems: influence of the type of QT interval correction.

    PubMed

    Gargiulo, Francesco; Fratini, Antonio; Sansone, Mario; Sansone, Carlo

    2015-10-01

    Electrocardiography (ECG) has been recently proposed as biometric trait for identification purposes. Intra-individual variations of ECG might affect identification performance. These variations are mainly due to Heart Rate Variability (HRV). In particular, HRV causes changes in the QT intervals along the ECG waveforms. This work is aimed at analysing the influence of seven QT interval correction methods (based on population models) on the performance of ECG-fiducial-based identification systems. In addition, we have also considered the influence of training set size, classifier, classifier ensemble as well as the number of consecutive heartbeats in a majority voting scheme. The ECG signals used in this study were collected from thirty-nine subjects within the Physionet open access database. Public domain software was used for fiducial points detection. Results suggested that QT correction is indeed required to improve the performance. However, there is no clear choice among the seven explored approaches for QT correction (identification rate between 0.97 and 0.99). MultiLayer Perceptron and Support Vector Machine seemed to have better generalization capabilities, in terms of classification performance, with respect to Decision Tree-based classifiers. No such strong influence of the training-set size and the number of consecutive heartbeats has been observed on the majority voting scheme.

  8. Discrete wavelet transform and singular value decomposition based ECG steganography for secured patient information transmission.

    PubMed

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

    2014-10-01

    ECG Steganography provides secured transmission of secret information such as patient personal information through ECG signals. This paper proposes an approach that uses discrete wavelet transform to decompose signals and singular value decomposition (SVD) to embed the secret information into the decomposed ECG signal. The novelty of the proposed method is to embed the watermark using SVD into the two dimensional (2D) ECG image. The embedding of secret information in a selected sub band of the decomposed ECG is achieved by replacing the singular values of the decomposed cover image by the singular values of the secret data. The performance assessment of the proposed approach allows understanding the suitable sub-band to hide secret data and the signal degradation that will affect diagnosability. Performance is measured using metrics like Kullback-Leibler divergence (KL), percentage residual difference (PRD), peak signal to noise ratio (PSNR) and bit error rate (BER). A dynamic location selection approach for embedding the singular values is also discussed. The proposed approach is demonstrated on a MIT-BIH database and the observations validate that HH is the ideal sub-band to hide data. It is also observed that the signal degradation (less than 0.6%) is very less in the proposed approach even with the secret data being as large as the sub band size. So, it does not affect the diagnosability and is reliable to transmit patient information.

  9. Prediction and prevention of sudden death in young populations: the role of ECG screening.

    PubMed

    Dougherty, Kevin R; Friedman, Richard A; Link, Mark S; Estes, N A Mark

    2013-03-01

    Sudden cardiac death (SCD), particularly when it affects a child or a young athlete who is presumed to be healthy, is an emotionally charged event that has a widespread impact. An effective ECG screening strategy for this population is intuitively appealing. The primary objective of ECG screening is to detect occult cardiovascular conditions likely to manifest with SCD. Such an endeavor is only effective if it is highly sensitive with an acceptably low false-positive rate. It also must be accompanied by an intervention that reduces the risk of SCD and improves outcomes. Despite significant advancements, considerable knowledge gaps remain about the etiology of SCD and the frequency with which SCD occurs. Reports of screening programs that have reduced the incidence of SCD have limited generalizability based on program design and the populations studied. Within the USA, considerable gaps in knowledge exist related to the frequency of SCD in youth and to the incremental predictive value of an ECG when added to a standardized history and physical examination. The strategy of ECG screening of young populations needs careful consideration based on principles of effective screening and evidence-based medicine. From a health policy perspective, additional data are needed from robust registries and carefully designed trials before advancing ECG screening in youth. PMID:23179925

  10. 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.

  11. 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

  12. Improved Clinical Risk Stratification in Patients with Long QT Syndrome? Novel Insights from Multi-Channel ECGs

    PubMed Central

    Samol, Alexander; Gönes, Mehmet; Zumhagen, Sven; Bruns, Hans-Jürgen; Paul, Matthias; Vahlhaus, Christian; Waltenberger, Johannes; Schulze-Bahr, Eric; Eckardt, Lars; Mönnig, Gerold

    2016-01-01

    Background We investigated whether multichannel ECG-recordings are useful to risk-stratify patients with congenital long-QT syndrome (LQTS) for risk of sudden cardiac death under optimized medical treatment. Methods In 34 LQTS-patients (11 male; age 31±13 years, QTc 478±51ms; LQT1 n = 8, LQT2 n = 15) we performed a standard 12-channel ECG and a 120-channel body surface potential mapping. The occurrence of clinical events (CE; syncope, torsade de pointes (TdP), sudden cardiac arrest (SCA)) was documented and correlated with different ECG-parameters in all lead positions. Results Seven patients developed TdP, four survived SCA and 12 experienced syncope. 12/34 had at least one CE. CE was associated with a longer QTc-interval (519±43ms vs. 458±42ms; p = 0.001), a lower T-wave integral (TWI) on the left upper chest (-1.2±74.4mV*ms vs. 63.0±29.7mV*ms; p = 0.001), a lower range of T-wave amplitude (TWA) in the region of chest lead V8 (0.10±0.08mV vs. 0.18±0.07mV; p = 0.008) and a longer T-peak-T-end time (TpTe) in lead V1 (98±23ms vs. 78±26ms; p = 0.04). Receiver-operating-characteristic (ROC) analyses revealed a sensitivity of 96% and a specificity of 75% (area under curve (AUC) 0.89±0.06, p = 0.001) at a cut-off value of 26.8mV*ms for prediction of CE by TWI, a sensitivity of 86% and a specificity of 83% at a cut-off value of 0.11mV (AUC 0.83±0.09, p = 0.002) for prediction of CE by TWA and a sensitivity of 83% and a specificity of 73% at a cut-off value of 87ms (AUC 0.80±0.07, p = 0.005) for prediction of CE by TpTe. Conclusions Occurrence of CE in LQTS-patients seems to be associated with a prolonged, low-amplitude T-wave. PMID:27379800

  13. Prolonged corrected QT interval is predictive of future stroke events even in subjects without ECG-diagnosed left ventricular hypertrophy.

    PubMed

    Ishikawa, Joji; Ishikawa, Shizukiyo; Kario, Kazuomi

    2015-03-01

    We attempted to evaluate whether subjects who exhibit prolonged corrected QT (QTc) interval (≥440 ms in men and ≥460 ms in women) on ECG, with and without ECG-diagnosed left ventricular hypertrophy (ECG-LVH; Cornell product, ≥244 mV×ms), are at increased risk of stroke. Among the 10 643 subjects, there were a total of 375 stroke events during the follow-up period (128.7±28.1 months; 114 142 person-years). The subjects with prolonged QTc interval (hazard ratio, 2.13; 95% confidence interval, 1.22-3.73) had an increased risk of stroke even after adjustment for ECG-LVH (hazard ratio, 1.71; 95% confidence interval, 1.22-2.40). When we stratified the subjects into those with neither a prolonged QTc interval nor ECG-LVH, those with a prolonged QTc interval but without ECG-LVH, and those with ECG-LVH, multivariate-adjusted Cox proportional hazards analysis demonstrated that the subjects with prolonged QTc intervals but not ECG-LVH (1.2% of all subjects; incidence, 10.7%; hazard ratio, 2.70, 95% confidence interval, 1.48-4.94) and those with ECG-LVH (incidence, 7.9%; hazard ratio, 1.83; 95% confidence interval, 1.31-2.57) had an increased risk of stroke events, compared with those with neither a prolonged QTc interval nor ECG-LVH. In conclusion, prolonged QTc interval was associated with stroke risk even among patients without ECG-LVH in the general population.

  14. ECG Prediction Based on Classification via Neural Networks and Linguistic Fuzzy Logic Forecaster.

    PubMed

    Volna, Eva; Kotyrba, Martin; Habiballa, Hashim

    2015-01-01

    The paper deals with ECG prediction based on neural networks classification of different types of time courses of ECG signals. The main objective is to recognise normal cycles and arrhythmias and perform further diagnosis. We proposed two detection systems that have been created with usage of neural networks. The experimental part makes it possible to load ECG signals, preprocess them, and classify them into given classes. Outputs from the classifiers carry a predictive character. All experimental results from both of the proposed classifiers are mutually compared in the conclusion. We also experimented with the new method of time series transparent prediction based on fuzzy transform with linguistic IF-THEN rules. Preliminary results show interesting results based on the unique capability of this approach bringing natural language interpretation of particular prediction, that is, the properties of time series. PMID:26221620

  15. 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

  16. Scuba diving, acute left anterior descending artery occlusion and normal ECG.

    PubMed

    Doll, Sébastien Xavier; Rigamonti, Fabio; Roffi, Marco; Noble, Stéphane

    2013-01-31

    We report the case of an acute proximal occlusion of the left anterior descending coronary (LAD) artery following a scuba diving decompression accident and associated with normal ECG. Following uneventful thromboaspiration and coronary stenting, the patient was discharged on day 4 with secondary preventative therapies. A transthoracic echocardiography performed at this point showed a complete recovery compared with an initial localised akinesia involving the anterior and apical portion of the left ventricle upon admission. This case highlights that significant acute coronary lesions involving the LAD can occur without any ECG anomaly. The presence of acute and persistent angina associated with troponin elevation should prompt physicians to consider coronary angiography without delay, independently of the ECG results.

  17. Using an injection signal to reduce motion artifacts in capacitive ECG measurements.

    PubMed

    Serteyn, Aline; Vullings, Rik; Meftah, Mohammed; Bergmans, Jan

    2013-01-01

    Capacitive electrodes are a promising alternative to the conventional adhesive ECG electrodes. They provide more comfort to the patient when integrated in everyday objects (e.g. beds or seats) for long-term monitoring. However, the application of such electrodes is limited by their high sensitivity to motion artifacts. Artifacts caused by variation of the coupling capacitance are studied here. An injection signal is proposed to track these variations in real-time. An adaptive filter then estimates the motion artifact and cancels it from the recorded ECG. The amplitude of the motion artifact is reduced in average by 29 dB in simulation and by 20 dB in a lab environment. Our method has the advantages that it is able to reduce motion artifacts occurring in the frequency band of the ECG and that it does not require knowledge about the measurement system.

  18. Comparison of JADE and canonical correlation analysis for ECG de-noising.

    PubMed

    Kuzilek, Jakub; Kremen, Vaclav; Lhotska, Lenka

    2014-01-01

    This paper explores differences between two methods for blind source separation within frame of ECG de-noising. First method is joint approximate diagonalization of eigenmatrices, which is based on estimation of fourth order cross-cummulant tensor and its diagonalization. Second one is the statistical method known as canonical correlation analysis, which is based on estimation of correlation matrices between two multidimensional variables. Both methods were used within method, which combines the blind source separation algorithm with decision tree. The evaluation was made on large database of 382 long-term ECG signals and the results were examined. Biggest difference was found in results of 50 Hz power line interference where the CCA algorithm completely failed. Thus main power of CCA lies in estimation of unstructured noise within ECG. JADE algorithm has larger computational complexity thus the CCA perfomed faster when estimating the components.

  19. 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

  20. 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.

  1. Development of standard test methods for evaluating defibrillation recovery characteristics of disposable ECG electrodes.

    PubMed

    Schoenberg, A A; Booth, H E; Lyon, P C

    1979-01-01

    A clinically relevant test for the measurement of defibrillation overload recovery of prefilled disposable ECG electrodes was developed and is proposed for use in an ECG electrode standard under development by AAMI. Defibrillation overload voltages and currents, as well as electrode polarization recovery voltages, were first measured in animal tests on 12 types of electrodes to allow correlation with various bench tests using a capacitor discharge at 10, 200, or 1000 V. Current overloads absorbed by the electrodes under worst conditions in animal tests were in the range of 2 percent of the defibrillation current flowing through the chest. These overloads were absorbed by most Ag-AgCl electrodes without excessive polarization. However, stainless steel, brass, and tin electrodes tended to polarize to levels that would saturate many ECG monitors. A standard bench test using a 200-V 10-muF capacitor was recommended for inclusion in the AAMI standard to determine whether electrodes are acceptable for use during defibrillation.

  2. Intelligent Classification of Heartbeats for Automated Real-Time ECG Monitoring

    PubMed Central

    Park, Juyoung

    2014-01-01

    Abstract Background: The automatic interpretation of electrocardiography (ECG) data can provide continuous analysis of heart activity, allowing the effective use of wireless devices such as the Holter monitor. Materials and Methods: We propose an intelligent heartbeat monitoring system to detect the possibility of arrhythmia in real time. We detected heartbeats and extracted features such as the QRS complex and P wave from ECG signals using the Pan–Tompkins algorithm, and the heartbeats were then classified into 16 types using a decision tree. Results: We tested the sensitivity, specificity, and accuracy of our system against data from the MIT-BIH Arrhythmia Database. Our system achieved an average accuracy of 97% in heartbeat detection and an average heartbeat classification accuracy of above 96%, which is comparable with the best competing schemes. Conclusions: This work provides a guide to the systematic design of an intelligent classification system for decision support in Holter ECG monitoring. PMID:25010717

  3. 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

  4. A novel ECG telemetry and monitoring system based on Z-Wave communication.

    PubMed

    Csernath, Geza; Szilagyi, Laszlo; Fordos, Gergely; Szilagyi, Sandor M

    2008-01-01

    This paper presents a novel ECG telemetry system based on Z-Wave communication protocol. The proposed system consists of small portable devices that acquire, compress and transmit the ECG to a RF-USB interface connected to a central monitoring computer. The received signals are filtered, QRS complexes and P and T waves are localized, and different waveforms are classified in order to be able to provide diagnosis tools like heart rate variability and turbulence analysis. Due to the limitation of communication bandwidth, the maximum number of measuring devices connected to a central monitor is four. The proposed system composed of inexpensive components can serve as flexible alternative to current ECG monitoring systems.

  5. 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

  6. 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.

  7. Robust off-line heartbeat detection using ECG and pressure-signals.

    PubMed

    Hoeben, Bart; Teo, Soo Kng; Yang, Bo; Su, Yi

    2016-01-01

    Artefacts in pressure- and ECG-signals generally arise due to different causes. Therefore, the combined analysis of both signals can increase the effectiveness of heartbeat detection compared to analysis using solely ECG-signals. In this paper, we present an algorithm for heartbeat annotation by combining the analysis of both the pressure- and ECG-signals. The novelties of our algorithm are as follows: (1) development of a new approach for annotating heartbeats using pressure-signals, (2) development of a mechanism that identifies and corrects paced rhythms, and (3) development of a noise detection approach. Our algorithm is tested on the datasets from the extended phase of the Physionet CINC-2014 challenge and produces an overall score of 87.31%. Finally, we put forth several recommendations that could further improve our algorithm.

  8. Comparison of JADE and canonical correlation analysis for ECG de-noising.

    PubMed

    Kuzilek, Jakub; Kremen, Vaclav; Lhotska, Lenka

    2014-01-01

    This paper explores differences between two methods for blind source separation within frame of ECG de-noising. First method is joint approximate diagonalization of eigenmatrices, which is based on estimation of fourth order cross-cummulant tensor and its diagonalization. Second one is the statistical method known as canonical correlation analysis, which is based on estimation of correlation matrices between two multidimensional variables. Both methods were used within method, which combines the blind source separation algorithm with decision tree. The evaluation was made on large database of 382 long-term ECG signals and the results were examined. Biggest difference was found in results of 50 Hz power line interference where the CCA algorithm completely failed. Thus main power of CCA lies in estimation of unstructured noise within ECG. JADE algorithm has larger computational complexity thus the CCA perfomed faster when estimating the components. PMID:25570833

  9. Sleep apnoea episodes recognition by a committee of ELM classifiers from ECG signal.

    PubMed

    Sadr, Nadi; de Chazal, Philip; van Schaik, Andre; Breen, Paul

    2015-01-01

    This paper describes a system for the recognition of sleep apnoea episodes from ECG signals using a committee of extreme learning machine (ELM) classifiers. RR-interval parameters (heart rate variability) have been used as the identifying features as they are directly affected by sleep apnoea. The MIT PhysioNet Apnea-ECG database was used. A committee of five ELM classifiers has been employed to classify one-minute epochs of ECG into normal or apnoeic epochs. Our results show that the classification performance from the committee of networks was superior to the results of a single ELM classifier for fan-outs from 1 to 100. Classification performance reached a plateau at a fan-out of 10. The maximum accuracy was 82.5% with a sensitivity of 81.9% and a specificity of 82.8%. The results were comparable to other published research with the same input data.

  10. On the application of optimal wavelet filter banks for ECG signal classification

    NASA Astrophysics Data System (ADS)

    Hadjiloucas, S.; Jannah, N.; Hwang, F.; Galvão, R. K. H.

    2014-03-01

    This paper discusses ECG signal classification after parametrizing the ECG waveforms in the wavelet domain. Signal decomposition using perfect reconstruction quadrature mirror filter banks can provide a very parsimonious representation of ECG signals. In the current work, the filter parameters are adjusted by a numerical optimization algorithm in order to minimize a cost function associated to the filter cut-off sharpness. The goal consists of achieving a better compromise between frequency selectivity and time resolution at each decomposition level than standard orthogonal filter banks such as those of the Daubechies and Coiflet families. Our aim is to optimally decompose the signals in the wavelet domain so that they can be subsequently used as inputs for training to a neural network classifier.

  11. 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.

  12. An ultra low power ECG signal processor design for cardiovascular disease detection.

    PubMed

    Jain, Sanjeev Kumar; Bhaumik, Basabi

    2015-08-01

    This paper presents an ultra low power ASIC design based on a new cardiovascular disease diagnostic algorithm. This new algorithm based on forward search is designed for real time ECG signal processing. The algorithm is evaluated for Physionet PTB database from the point of view of cardiovascular disease diagnosis. The failed detection rate of QRS complex peak detection of our algorithm ranges from 0.07% to 0.26% for multi lead ECG signal. The ASIC is designed using 130-nm CMOS low leakage process technology. The area of ASIC is 1.21 mm(2). This ASIC consumes only 96 nW at an operating frequency of 1 kHz with a supply voltage of 0.9 V. Due to ultra low power consumption, our proposed ASIC design is most suitable for energy efficient wearable ECG monitoring devices.

  13. ECG Prediction Based on Classification via Neural Networks and Linguistic Fuzzy Logic Forecaster

    PubMed Central

    Volna, Eva; Kotyrba, Martin; Habiballa, Hashim

    2015-01-01

    The paper deals with ECG prediction based on neural networks classification of different types of time courses of ECG signals. The main objective is to recognise normal cycles and arrhythmias and perform further diagnosis. We proposed two detection systems that have been created with usage of neural networks. The experimental part makes it possible to load ECG signals, preprocess them, and classify them into given classes. Outputs from the classifiers carry a predictive character. All experimental results from both of the proposed classifiers are mutually compared in the conclusion. We also experimented with the new method of time series transparent prediction based on fuzzy transform with linguistic IF-THEN rules. Preliminary results show interesting results based on the unique capability of this approach bringing natural language interpretation of particular prediction, that is, the properties of time series. PMID:26221620

  14. Labview Based ECG Patient Monitoring System for Cardiovascular Patient Using SMTP Technology.

    PubMed

    Singh, Om Prakash; Mekonnen, Dawit; Malarvili, M B

    2015-01-01

    This paper leads to developing a Labview based ECG patient monitoring system for cardiovascular patient using Simple Mail Transfer Protocol technology. The designed device has been divided into three parts. First part is ECG amplifier circuit, built using instrumentation amplifier (AD620) followed by signal conditioning circuit with the operation amplifier (lm741). Secondly, the DAQ card is used to convert the analog signal into digital form for the further process. Furthermore, the data has been processed in Labview where the digital filter techniques have been implemented to remove the noise from the acquired signal. After processing, the algorithm was developed to calculate the heart rate and to analyze the arrhythmia condition. Finally, SMTP technology has been added in our work to make device more communicative and much more cost-effective solution in telemedicine technology which has been key-problem to realize the telediagnosis and monitoring of ECG signals. The technology also can be easily implemented over already existing Internet.

  15. 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.

  16. ECG Prediction Based on Classification via Neural Networks and Linguistic Fuzzy Logic Forecaster.

    PubMed

    Volna, Eva; Kotyrba, Martin; Habiballa, Hashim

    2015-01-01

    The paper deals with ECG prediction based on neural networks classification of different types of time courses of ECG signals. The main objective is to recognise normal cycles and arrhythmias and perform further diagnosis. We proposed two detection systems that have been created with usage of neural networks. The experimental part makes it possible to load ECG signals, preprocess them, and classify them into given classes. Outputs from the classifiers carry a predictive character. All experimental results from both of the proposed classifiers are mutually compared in the conclusion. We also experimented with the new method of time series transparent prediction based on fuzzy transform with linguistic IF-THEN rules. Preliminary results show interesting results based on the unique capability of this approach bringing natural language interpretation of particular prediction, that is, the properties of time series.

  17. Pseudo-ischaemic ECG in a patient with amyotrophic lateral sclerosis surviving for a decade

    PubMed Central

    Zhang, Jian; Yang, Shi-Wei; Wang, Zheng; Wei, Guang-Ru; Zhou, Yu-Jie

    2012-01-01

    A 58-year-old female with no history of heart disease was admitted to our hospital for abnormal ECG mimicking myocardial ischaemia. The ECG revealed persistent T-wave inversion in almost all leads, especially in precordial leads V2–V6. The patient had no complaints of chest pain, chest distress, short of breath or other atypical myocardial ischaemia symptoms. She had a history of amyotrophic lateral sclerosis (ALS) with a disease course more than 20 years. Examinations help rule out other diseases causing persistent T-wave inversion. Importantly, cardiac catheterisation showed nearly normal coronary arteries that could rule out myocardial ischaemia. Accordingly, the authors presumed that the pseudo-ischaemic ECG was associated with ALS in this patient. The findings of the present case provide new evidence that autonomic nervous system may involve in the pathophysiological progress of ALS. PMID:22665549

  18. An ultra low power ECG signal processor design for cardiovascular disease detection.

    PubMed

    Jain, Sanjeev Kumar; Bhaumik, Basabi

    2015-08-01

    This paper presents an ultra low power ASIC design based on a new cardiovascular disease diagnostic algorithm. This new algorithm based on forward search is designed for real time ECG signal processing. The algorithm is evaluated for Physionet PTB database from the point of view of cardiovascular disease diagnosis. The failed detection rate of QRS complex peak detection of our algorithm ranges from 0.07% to 0.26% for multi lead ECG signal. The ASIC is designed using 130-nm CMOS low leakage process technology. The area of ASIC is 1.21 mm(2). This ASIC consumes only 96 nW at an operating frequency of 1 kHz with a supply voltage of 0.9 V. Due to ultra low power consumption, our proposed ASIC design is most suitable for energy efficient wearable ECG monitoring devices. PMID:26736397

  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. 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.

  1. Non-ECG-Gated Myocardial Perfusion MRI Using Continuous Magnetization-Driven Radial Sampling

    PubMed Central

    Sharif, Behzad; Dharmakumar, Rohan; Arsanjani, Reza; Thomson, Louise; Merz, C. Noel Bairey; Berman, Daniel S.; Li, Debiao

    2014-01-01

    Purpose Establishing a high-resolution non-ECG-gated first-pass perfusion (FPP) cardiac MRI technique may improve accessibility and diagnostic capability of FPP imaging. We propose a non-ECG-gated FPP imaging technique using continuous magnetization-driven golden-angle radial acquisition. The main purpose of this preliminary study is to evaluate whether, in the simple case of single-slice 2D imaging, adequate myocardial contrast can be obtained for accurate visualization of hypoperfused territories in the setting of myocardial ischemia. Methods A T1-weighted pulse sequence with continuous golden-angle radial sampling was developed for non-ECG-gated FPP imaging. A sliding-window scheme with no temporal acceleration was used to reconstruct 8 frames/second. Canines were imaged at 3T with and without coronary stenosis using the proposed scheme and a conventional magnetization-prepared ECG-gated FPP method. Results Our studies showed that the proposed non-ECG-gated method is capable of generating high-resolution (1.7×1.7×6 mm3) artifact-free FPP images of a single slice at high heart rates (92±21 beats/minute), while matching the performance of conventional FPP imaging in terms of hypoperfused-to-normal myocardial contrast-to-noise ratio (proposed: 5.18±0.70, conventional: 4.88±0.43). Furthermore, the detected perfusion defect areas were consistent with the conventional FPP images. Conclusion Non-ECG-gated FPP imaging using optimized continuous golden-angle radial acquisition achieves desirable image quality (i.e., adequate myocardial contrast, high spatial resolution, and minimal artifacts) in the setting of ischemia. PMID:24443160

  2. Management of serial ECGs and control strategies for the comparison process.

    PubMed

    Fayn, J; Rubel, P; Willems, J L

    1994-03-01

    Serial ECG management and control of the comparison process should be dynamically driven by patient data. The functional architecture requirements are specified for a computerized ECG processing system integrating serial analysis. The concepts of reference investigations and temporal events are first explained. A conceptual reference model is proposed which stratifies the serial analysis process into a few generic strategies which will be instantiated into several types of serial comparison processing tasks as a function of the clinical evolution of the patient. This model is an extension of the OEDIPE core data model developed and implemented during the AIM #2026 project.

  3. Skin-electrode impedance measurement during ECG acquisition: method’s validation

    NASA Astrophysics Data System (ADS)

    Casal, Leonardo; La Mura, Guillermo

    2016-04-01

    Skm-electrode impedance measurement can provide valuable information prior. dunng and post electrocardiographic (ECG) or electroencephalographs (EEG) acquisitions. In this work we validate a method for skm-electrode impedance measurement using test circuits with known resistance and capacitor values, at different frequencies for injected excitation current. Finally the method is successfully used for impedance measurement during ECG acquisition on a subject usmg 125 Hz and 6 nA square wave excitation signal at instrumentation amplifier mput. The method can be used for many electrodes configuration.

  4. A portable ECG monitoring device with Bluetooth and Holter capabilities for telemedicine applications.

    PubMed

    Lucani, Daniel; Cataldo, Giancarlos; Cruz, Julio; Villegas, Guillermo; Wong, Sara

    2006-01-01

    A prototype of a portable ECG-monitoring device has been developed for clinical and non-clinical environments as part of a telemedicine system to provide remote and continuous surveillance of patients. The device can acquire, store and/or transmit ECG signals to computer-based platforms or specially configured access points (AP) with Intranet/Internet capabilities in order to reach remote monitoring stations. Acquired data can be stored in a flash memory card in FAT16 format for later recovery, or transmitted via Bluetooth or USB to a local station or AP. This data acquisition module (DAM) operates in two modes: Holter and on-line transmission.

  5. [Adaptive de-noising of ECG signal based on stationary wavelet transform].

    PubMed

    Dong, Hong-sheng; Zhang, Ai-hua; Hao, Xiao-hong

    2009-03-01

    According to the limitations of wavelet threshold in de-noising method, we approached a combining algorithm of the stationary wavelet transform with adaptive filter. The stationary wavelet transformation can suppress Gibbs phenomena in traditional DWT effectively, and adaptive filter is introduced at the high scale wavelet coefficient of the stationary wavelet transformation. It would remove baseline wander and keep the shape of low frequency and low amplitude P wave, T wave and ST segment wave of ECG signal well. That is important for analyzing ECG signal of other feature information.

  6. 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.

  7. 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.

  8. 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.

  9. Anatomic distribution of culprit lesions in patients with non-ST-segment elevation myocardial infarction and normal ECG

    PubMed Central

    Moustafa, Abdelmoniem; Abi-Saleh, Bernard; El-Baba, Mohammad; Hamoui, Omar

    2016-01-01

    Background In patients presenting with non-ST-elevation myocardial infarction (NSTEMI), left anterior descending (LAD) coronary artery and three-vessel disease are the most commonly encountered culprit lesions in the presence of ST depression, while one third of patients with left circumflex (LCX) artery related infarction have normal ECG. We sought to determine the predictors of presence of culprit lesion in NSTEMI patients based on ECG, echocardiographic, and clinical characteristics. Methods Patients admitted to the coronary care unit with the diagnosis of NSTEMI between June 2012 and December 2013 were retrospectively identified. Admission ECG was interpreted by an electrophysiologist that was blinded to the result of the coronary angiogram. Patients were dichotomized into either normal or abnormal ECG group. The primary endpoint was presence of culprit lesion. Secondary endpoints included length of stay, re-hospitalization within 60 days, and in-hospital mortality. Results A total of 118 patients that were identified; 47 with normal and 71 with abnormal ECG. At least one culprit lesion was identified in 101 patients (86%), and significantly more among those with abnormal ECG (91.5% vs. 76.6%, P=0.041).The LAD was the most frequently detected culprit lesion in both groups. There was a higher incidence of two and three-vessel disease in the abnormal ECG group (P=0.041).On the other hand, there was a trend of higher LCX involvement (25% vs. 13.8%, P=0.18) and more normal coronary arteries in the normal ECG group (23.4% vs. 8.5%, P=0.041). On multivariate analysis, prior history of coronary artery disease (CAD) [odds ratio (OR) 6.4 (0.8-52)], male gender [OR 5.0 (1.5-17)], and abnormal admission ECG [OR 3.6 (1.12-12)], were independent predictors of a culprit lesion. There was no difference in secondary endpoints between those with normal and abnormal ECG. Conclusions Among patients presenting with NSTEMI, prior history of CAD, male gender and abnormal admission

  10. Compression and Encryption of ECG Signal Using Wavelet and Chaotically Huffman Code in Telemedicine Application.

    PubMed

    Raeiatibanadkooki, Mahsa; Quchani, Saeed Rahati; KhalilZade, MohammadMahdi; Bahaadinbeigy, Kambiz

    2016-03-01

    In mobile health care monitoring, compression is an essential tool for solving storage and transmission problems. The important issue is able to recover the original signal from the compressed signal. The main purpose of this paper is compressing the ECG signal with no loss of essential data and also encrypting the signal to keep it confidential from everyone, except for physicians. In this paper, mobile processors are used and there is no need for any computers to serve this purpose. After initial preprocessing such as removal of the baseline noise, Gaussian noise, peak detection and determination of heart rate, the ECG signal is compressed. In compression stage, after 3 steps of wavelet transform (db04), thresholding techniques are used. Then, Huffman coding with chaos for compression and encryption of the ECG signal are used. The compression rates of proposed algorithm is 97.72 %. Then, the ECG signals are sent to a telemedicine center to acquire specialist diagnosis by TCP/IP protocol. PMID:26779641

  11. Multiadaptive Bionic Wavelet Transform: Application to ECG Denoising and Baseline Wandering Reduction

    NASA Astrophysics Data System (ADS)

    Sayadi, Omid; Shamsollahi, Mohammad B.

    2007-12-01

    We present a new modified wavelet transform, called the multiadaptive bionic wavelet transform (MABWT), that can be applied to ECG signals in order to remove noise from them under a wide range of variations for noise. By using the definition of bionic wavelet transform and adaptively determining both the center frequency of each scale together with the[InlineEquation not available: see fulltext.]-function, the problem of desired signal decomposition is solved. Applying a new proposed thresholding rule works successfully in denoising the ECG. Moreover by using the multiadaptation scheme, lowpass noisy interference effects on the baseline of ECG will be removed as a direct task. The method was extensively clinically tested with real and simulated ECG signals which showed high performance of noise reduction, comparable to those of wavelet transform (WT). Quantitative evaluation of the proposed algorithm shows that the average SNR improvement of MABWT is 1.82 dB more than the WT-based results, for the best case. Also the procedure has largely proved advantageous over wavelet-based methods for baseline wandering cancellation, including both DC components and baseline drifts.

  12. 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

  13. 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.

  14. [Changes in ECG indicators during bicycle ergometry in patients having suffered myocardial infarction].

    PubMed

    Kheifets, Z N

    1984-01-01

    Altogether 218 patients with a history of myocardial infarction were subjected to bicycle ergometry. The ECG recorded at the height of the exercise showed a significant increase in the heart rate and in the amplitudes of P and R waves. The diastole and electric systole shortened. As the load was raised, the rate of A-B conduction was relatively decelerated.

  15. 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.

  16. 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

  17. Using statistical distances to detect changes in the normal behavior of ECG-Holter signals

    NASA Astrophysics Data System (ADS)

    Bastos de Figueiredo, Julio C.; Furuie, Sergio S.

    2001-05-01

    One of the main problems in the study of complex systems is to define a good metric that can distinguish between different dynamical behaviors in a nonlinear system. In this work we describe a method to detect different types of behaviors in a long term ECG-Holter using short portions of the Holter signal. This method is based on the calculation of the statistical distance between two distributions in a phase-space of a dynamical system. A short portion of an ECG-Holter signal with normal behavior is used to reconstruct the trajectory of an attractor in low dimensional phase-space. The points in this trajectory are interpreted as statistical distributions in the phase-space and assumed to represent the normal dynamical behavior of the ECG recording in this space. A fast algorithm is then used to compute the statistical distance between this attractor and all other attractors that are built using a sliding temporal window over the signal. For normal cases the distance stayed almost constant and below a threshold. For cases with abnormal transients, on the abnormal portion of ECG, the distance increased consistently with morphological changes.

  18. Efficient ECG signal analysis using wavelet technique for arrhythmia detection: an ANFIS approach

    NASA Astrophysics Data System (ADS)

    Khandait, P. D.; Bawane, N. G.; Limaye, S. S.

    2010-02-01

    This paper deals with improved ECG signal analysis using Wavelet Transform Techniques and employing subsequent modified feature extraction for Arrhythmia detection based on Neuro-Fuzzy technique. This improvement is based on suitable choice of features in evaluating and predicting life threatening Ventricular Arrhythmia . Analyzing electrocardiographic signals (ECG) includes not only inspection of P, QRS and T waves, but also the causal relations they have and the temporal sequences they build within long observation periods. Wavelet-transform is used for effective feature extraction and Adaptive Neuro-Fuzzy Inference System (ANFIS) is considered for the classifier model. In a first step, QRS complexes are detected. Then, each QRS is delineated by detecting and identifying the peaks of the individual waves, as well as the complex onset and end. Finally, the determination of P and T wave peaks, onsets and ends is performed. We evaluated the algorithm on several manually annotated databases, such as MIT-BIH Arrhythmia and CSE databases, developed for validation purposes. Features based on the ECG waveform shape and heart beat intervals are used as inputs to the classifiers. The performance of the ANFIS model is 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. Cross validation is used to measure the classifier performance. A testing classification accuracy of 95.13% is achieved which is a significant improvement.

  19. Evaluation of Digital Compressed Sensing for Real-Time Wireless ECG System with Bluetooth low Energy.

    PubMed

    Wang, Yishan; Doleschel, Sammy; Wunderlich, Ralf; Heinen, Stefan

    2016-07-01

    In this paper, a wearable and wireless ECG system is firstly designed with Bluetooth Low Energy (BLE). It can detect 3-lead ECG signals and is completely wireless. Secondly the digital Compressed Sensing (CS) is implemented to increase the energy efficiency of wireless ECG sensor. Different sparsifying basis, various compression ratio (CR) and several reconstruction algorithms are simulated and discussed. Finally the reconstruction is done by the android application (App) on smartphone to display the signal in real time. The power efficiency is measured and compared with the system without CS. The optimum satisfying basis built by 3-level decomposed db4 wavelet coefficients, 1-bit Bernoulli random matrix and the most suitable reconstruction algorithm are selected by the simulations and applied on the sensor node and App. The signal is successfully reconstructed and displayed on the App of smartphone. Battery life of sensor node is extended from 55 h to 67 h. The presented wireless ECG system with CS can significantly extend the battery life by 22 %. With the compact characteristic and long term working time, the system provides a feasible solution for the long term homecare utilization. PMID:27240841

  20. Wireless Sensor-Based Smart-Clothing Platform for ECG Monitoring.

    PubMed

    Wang, Jie; Lin, Chung-Chih; Yu, Yan-Shuo; Yu, Tsang-Chu

    2015-01-01

    The goal of this study is to use wireless sensor technologies to develop a smart clothes service platform for health monitoring. Our platform consists of smart clothes, a sensor node, a gateway server, and a health cloud. The smart clothes have fabric electrodes to detect electrocardiography (ECG) signals. The sensor node improves the accuracy of QRS complexes detection by morphology analysis and reduces power consumption by the power-saving transmission functionality. The gateway server provides a reconfigurable finite state machine (RFSM) software architecture for abnormal ECG detection to support online updating. Most normal ECG can be filtered out, and the abnormal ECG is further analyzed in the health cloud. Three experiments are conducted to evaluate the platform's performance. The results demonstrate that the signal-to-noise ratio (SNR) of the smart clothes exceeds 37 dB, which is within the "very good signal" interval. The average of the QRS sensitivity and positive prediction is above 99.5%. Power-saving transmission is reduced by nearly 1980 times the power consumption in the best-case analysis.

  1. ECG Rhythm Analysis with Expert and Learner-Generated Schemas in Novice Learners

    ERIC Educational Resources Information Center

    Blissett, Sarah; Cavalcanti, Rodrigo; Sibbald, Matthew

    2015-01-01

    Although instruction using expert-generated schemas is associated with higher diagnostic performance, implementation is resource intensive. Learner-generated schemas are an alternative, but may be limited by increases in cognitive load. We compared expert- and learner-generated schemas for learning ECG rhythm interpretation on diagnostic accuracy,…

  2. 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

  3. 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

  4. Food and Insulin Effect on QT/QTC Interval of ECG

    ClinicalTrials.gov

    2014-08-19

    Effects of Different Meals on the QT/QTc Interval; Insulin and Oral Hypoglycemic [Antidiabetic] Drugs Causing Adverse Effects in Therapeutic Use; C-Peptide Effects on the QT/QTc Interval; Moxifloxacin ECG Profile in Fed and Fasted State; Japanese vs. Caucasian TQT Comparison

  5. 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.

  6. An intelligent telecardiology system using a wearable and wireless ECG to detect atrial fibrillation.

    PubMed

    Lin, Chin-Teng; Chang, Kuan-Cheng; Lin, Chun-Ling; Chiang, Chia-Cheng; Lu, Shao-Wei; Chang, Shih-Sheng; Lin, Bor-Shyh; Liang, Hsin-Yueh; Chen, Ray-Jade; Lee, Yuan-Teh; Ko, Li-Wei

    2010-05-01

    This study presents a novel wireless, ambulatory, real-time, and autoalarm intelligent telecardiology system to improve healthcare for cardiovascular disease, which is one of the most prevalent and costly health problems in the world. This system consists of a lightweight and power-saving wireless ECG device equipped with a built-in automatic warning expert system. This device is connected to a mobile and ubiquitous real-time display platform. The acquired ECG signals are instantaneously transmitted to mobile devices, such as netbooks or mobile phones through Bluetooth, and then, processed by the expert system. An alert signal is sent to the remote database server, which can be accessed by an Internet browser, once an abnormal ECG is detected. The current version of the expert system can identify five types of abnormal cardiac rhythms in real-time, including sinus tachycardia, sinus bradycardia, wide QRS complex, atrial fibrillation (AF), and cardiac asystole, which is very important for both the subjects who are being monitored and the healthcare personnel tracking cardiac-rhythm disorders. The proposed system also activates an emergency medical alarm system when problems occur. Clinical testing reveals that the proposed system is approximately 94% accurate, with high sensitivity, specificity, and positive prediction rates for ten normal subjects and 20 AF patients. We believe that in the future a business-card-like ECG device, accompanied with a mobile phone, can make universal cardiac protection service possible.

  7. Evaluation of Digital Compressed Sensing for Real-Time Wireless ECG System with Bluetooth low Energy.

    PubMed

    Wang, Yishan; Doleschel, Sammy; Wunderlich, Ralf; Heinen, Stefan

    2016-07-01

    In this paper, a wearable and wireless ECG system is firstly designed with Bluetooth Low Energy (BLE). It can detect 3-lead ECG signals and is completely wireless. Secondly the digital Compressed Sensing (CS) is implemented to increase the energy efficiency of wireless ECG sensor. Different sparsifying basis, various compression ratio (CR) and several reconstruction algorithms are simulated and discussed. Finally the reconstruction is done by the android application (App) on smartphone to display the signal in real time. The power efficiency is measured and compared with the system without CS. The optimum satisfying basis built by 3-level decomposed db4 wavelet coefficients, 1-bit Bernoulli random matrix and the most suitable reconstruction algorithm are selected by the simulations and applied on the sensor node and App. The signal is successfully reconstructed and displayed on the App of smartphone. Battery life of sensor node is extended from 55 h to 67 h. The presented wireless ECG system with CS can significantly extend the battery life by 22 %. With the compact characteristic and long term working time, the system provides a feasible solution for the long term homecare utilization.

  8. Automatic detection of respiration rate from ambulatory single-lead ECG.

    PubMed

    Boyle, Justin; Bidargaddi, Niranjan; Sarela, Antti; Karunanithi, Mohan

    2009-11-01

    Ambulatory electrocardiography is increasingly being used in clinical practice to detect abnormal electrical behavior of the heart during ordinary daily activities. The utility of this monitoring can be improved by deriving respiration, which previously has been based on overnight apnea studies where patients are stationary, or the use of multilead ECG systems for stress testing. We compared six respiratory measures derived from a single-lead portable ECG monitor with simultaneously measured respiration air flow obtained from an ambulatory nasal cannula respiratory monitor. Ten controlled 1-h recordings were performed covering activities of daily living (lying, sitting, standing, walking, jogging, running, and stair climbing) and six overnight studies. The best method was an average of a 0.2-0.8 Hz bandpass filter and RR technique based on lengthening and shortening of the RR interval. Mean error rates with the reference gold standard were +/-4 breaths per minute (bpm) (all activities), +/-2 bpm (lying and sitting), and +/-1 breath per minute (overnight studies). Statistically similar results were obtained using heart rate information alone (RR technique) compared to the best technique derived from the full ECG waveform that simplifies data collection procedures. The study shows that respiration can be derived under dynamic activities from a single-lead ECG without significant differences from traditional methods. PMID:19775978

  9. Extracting the respiration cycle lengths from ECG signal recorded with bed sheet electrodes

    NASA Astrophysics Data System (ADS)

    Vehkaoja, A.; Peltokangas, M.; Lekkala, J.

    2013-09-01

    A method for recognizing the respiration cycle lengths from the electrocardiographic (ECG) signal recorded with textile electrodes that are attached to a bed sheet is proposed. The method uses two features extracted from the ECG that are affected by the respiration: respiratory sinus arrhythmia and the amplitude of the R-peaks. The proposed method was tested in one hour long recordings with ten healthy young adults. A relative mean absolute error of 5.6 % was achieved when the algorithm was able to provide a result for approximately 40 % of the time. 90 % of the values were within 0.5 s and 97 % within 1 s from the reference respiration value. In addition to the instantaneous respiration cycle lengths, also the mean values during 1 and 5 minutes epochs are calculated. The effect of the ECG signal source is evaluated by calculating the result also from the simultaneously recorded reference ECG signal. The acquired respiration information can be used in the estimation of sleep quality and the detection of sleep disorders.

  10. An Autonomous Wireless Sensor Node With Asynchronous ECG Monitoring in 0.18 μ m CMOS.

    PubMed

    Mansano, Andre L; Li, Yongjia; Bagga, Sumit; Serdijn, Wouter A

    2016-06-01

    The design of a 13.56 MHz/402 MHz autonomous wireless sensor node with asynchronous ECG monitoring for near field communication is presented. The sensor node consists of an RF energy harvester (RFEH), a power management unit, an ECG readout, a data encoder and an RF backscattering transmitter. The energy harvester supplies the system with 1.25 V and offers a power conversion efficiency of 19% from a -13 dBm RF source at 13.56 MHz. The power management unit regulates the output voltage of the RFEH to supply the ECG readout with VECG = 0.95 V and the data encoder with VDE = 0.65 V . The ECG readout comprises an analog front-end (low noise amplifier and programmable voltage to current converter) and an asynchronous level crossing ADC with 8 bits resolution. The ADC output is encoded by a pulse generator that drives a backscattering transmitter at 402 MHz. The total power consumption of the sensor node circuitry is 9.7 μ W for a data rate of 90 kb/s and a heart rate of 70 bpm. The chip has been designed in a 0.18 μm CMOS process and shows superior RF input power sensitivity and lower power consumption when compared to previous works. PMID:26812734

  11. An intelligent telecardiology system using a wearable and wireless ECG to detect atrial fibrillation.

    PubMed

    Lin, Chin-Teng; Chang, Kuan-Cheng; Lin, Chun-Ling; Chiang, Chia-Cheng; Lu, Shao-Wei; Chang, Shih-Sheng; Lin, Bor-Shyh; Liang, Hsin-Yueh; Chen, Ray-Jade; Lee, Yuan-Teh; Ko, Li-Wei

    2010-05-01

    This study presents a novel wireless, ambulatory, real-time, and autoalarm intelligent telecardiology system to improve healthcare for cardiovascular disease, which is one of the most prevalent and costly health problems in the world. This system consists of a lightweight and power-saving wireless ECG device equipped with a built-in automatic warning expert system. This device is connected to a mobile and ubiquitous real-time display platform. The acquired ECG signals are instantaneously transmitted to mobile devices, such as netbooks or mobile phones through Bluetooth, and then, processed by the expert system. An alert signal is sent to the remote database server, which can be accessed by an Internet browser, once an abnormal ECG is detected. The current version of the expert system can identify five types of abnormal cardiac rhythms in real-time, including sinus tachycardia, sinus bradycardia, wide QRS complex, atrial fibrillation (AF), and cardiac asystole, which is very important for both the subjects who are being monitored and the healthcare personnel tracking cardiac-rhythm disorders. The proposed system also activates an emergency medical alarm system when problems occur. Clinical testing reveals that the proposed system is approximately 94% accurate, with high sensitivity, specificity, and positive prediction rates for ten normal subjects and 20 AF patients. We believe that in the future a business-card-like ECG device, accompanied with a mobile phone, can make universal cardiac protection service possible. PMID:20371411

  12. Wireless Sensor-Based Smart-Clothing Platform for ECG Monitoring

    PubMed Central

    Wang, Jie; Lin, Chung-Chih; Yu, Yan-Shuo; Yu, Tsang-Chu

    2015-01-01

    The goal of this study is to use wireless sensor technologies to develop a smart clothes service platform for health monitoring. Our platform consists of smart clothes, a sensor node, a gateway server, and a health cloud. The smart clothes have fabric electrodes to detect electrocardiography (ECG) signals. The sensor node improves the accuracy of QRS complexes detection by morphology analysis and reduces power consumption by the power-saving transmission functionality. The gateway server provides a reconfigurable finite state machine (RFSM) software architecture for abnormal ECG detection to support online updating. Most normal ECG can be filtered out, and the abnormal ECG is further analyzed in the health cloud. Three experiments are conducted to evaluate the platform's performance. The results demonstrate that the signal-to-noise ratio (SNR) of the smart clothes exceeds 37 dB, which is within the “very good signal” interval. The average of the QRS sensitivity and positive prediction is above 99.5%. Power-saving transmission is reduced by nearly 1980 times the power consumption in the best-case analysis. PMID:26640512

  13. Cost-effectiveness analysis of computerized ECG interpretation system in an ambulatory health care organization.

    PubMed

    Carel, R S

    1982-04-01

    The cost-effectiveness of a computerized ECG interpretation system in an ambulatory health care organization has been evaluated in comparison with a conventional (manual) system. The automated system was shown to be more cost-effective at a minimum load of 2,500 patients/month. At larger monthly loads an even greater cost-effectiveness was found, the average cost/ECG being about $2. In the manual system the cost/unit is practically independent of patient load. This is primarily due to the fact that 87% of the cost/ECG is attributable to wages and fees of highly trained personnel. In the automated system, on the other hand, the cost/ECG is heavily dependent on examinee load. This is due to the relatively large impact of equipment depreciation on fixed (and total) cost. Utilization of a computer-assisted system leads to marked reduction in cardiologists' interpretation time, substantially shorter turnaround time (of unconfirmed reports), and potential provision of simultaneous service at several remotely located "heart stations."

  14. Application of computerized exercise ECG digitization. Interpretation in large clinical trials.

    PubMed

    Caralis, D G; Shaw, L; Bilgere, B; Younis, L; Stocke, K; Wiens, R D; Chaitman, B R

    1992-04-01

    The authors report on a semiautomated program that incorporates both visual identification of fiducial points and digital determination of the ST-segment at 60 ms and 80 ms from the J point, ST slope, changes in R wave, and baseline drift. The off-line program can enhance the accuracy of detecting electrocardiographic (ECG) changes, as well as reproducibility of the exercise and postexercise ECG, as a marker of myocardial ischemia. The analysis program is written in Microsoft QuickBASIC 2.0 for an IBM personal computer interfaced to a Summagraphics mm1201 microgrid II digitizer. The program consists of the following components: (1) alphanumeric data entry, (2) ECG wave form digitization, (2) calculation of test results, (4) physician overread, and (5) editor function for remeasurements. This computerized exercise ECG digitization-interpretation program is accurate and reproducible for the quantitative assessment of ST changes and requires minimal time allotment for physician overread. The program is suitable for analysis and interpretation of large volumes of exercise tests in multicenter clinical trials and is currently utilized in the TIMI II, TIMI III, and BARI studies sponsored by the National Institutes of Health. PMID:1522395

  15. 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

  16. 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

  17. 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.

  18. An ultra-low power (ULP) bandage-type ECG sensor for efficient cardiac disease management.

    PubMed

    Shin, Kunsoo; Park, G G; Kim, J P; Lee, T H; Ko, B H; Kim, Y H

    2013-01-01

    This paper proposed an ultra-low power bandage-type ECG sensor (the size: 76 × 34 × 3 (mm(3)) and the power consumption: 1 mW) which allows for a continuous and real-time monitoring of a user's ECG signals over 24h during daily activities. For its compact size and lower power consumption, we designed the analog front-end, the SRP (Samsung Reconfigurable Processor) based DSP of 30 uW/MHz, and the ULP wireless RF of 1 nJ/bit. Also, to tackle motion artifacts(MA), a MA monitoring technique based on the HCP (Half-cell Potential) is proposed which resulted in the high correlation between the MA and the HCP, the correlation coefficient of 0.75 ± 0.18. To assess its feasibility and validity as a wearable health monitor, we performed the comparison of two ECG signals recorded form it and a conventional Holter device. As a result, the performance of the former is a little lower as compared with the latter, although showing no statistical significant difference (the quality of the signal: 94.3% vs 99.4%; the accuracy of arrhythmia detection: 93.7% vs 98.7%). With those results, it has been confirmed that it can be used as a wearable health monitor due to its comfortability, its long operation lifetime and the good quality of the measured ECG signal.

  19. An ECG-based Algorithm for the Automatic Identification of Autonomic Activations Associated with Cortical Arousal

    PubMed Central

    Basner, Mathias; Griefahn, Barbara; Müller, Uwe; Plath, Gernot; Samel, Alexander

    2007-01-01

    Objectives: EEG arousals are associated with autonomic activations. Visual EEG arousal scoring is time consuming and suffers from low interobserver agreement. We hypothesized that information on changes in heart rate alone suffice to predict the occurrence of cortical arousal. Methods: Two visual AASM EEG arousal scorings of 56 healthy subject nights (mean age 37.0 ± 12.8 years, 26 male) were obtained. For each of 5 heartbeats following the onset of 3581 consensus EEG arousals and of an equal number of control conditions, differences to a moving median were calculated and used to estimate likelihood ratios (LRs) for 10 categories of heartbeat differences. Comparable to 5 consecutive diagnostic tests, these LRs were used to calculate the probability of heart rate responses being associated with cortical arousals. Results: EEG and ECG arousal indexes agreed well across a wide range of decision thresholds, resulting in a receiver operating characteristic (ROC) with an area under the curve of 0.91. For the decision threshold chosen for the final analyses, a sensitivity of 68.1% and a specificity of 95.2% were obtained. ECG and EEG arousal indexes were poorly correlated (r = 0.19, P <0.001, ICC = 0.186), which could in part be attributed to 3 outliers. The Bland-Altman plot showed an unbiased estimation of EEG arousal indexes by ECG arousal indexes with a standard deviation of ± 7.9 arousals per hour sleep. In about two-thirds of all cases, ECG arousal scoring was matched by at least one (22.2%) or by both (42.5%) of the visual scorings. Sensitivity of the algorithm increased with increasing duration of EEG arousals. The ECG algorithm was also successfully validated with 30 different nights of 10 subjects (mean age 35.3 ▯ 13.6 years, 5 male). Conclusions: In its current version, the ECG algorithm cannot replace visual EEG arousal scoring. Sensitivity for detecting <10-s EEG arousals needs to be improved. However, in a nonclinical population, it may be valuable to

  20. 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.

  1. 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

  2. ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

    PubMed Central

    Creta, Antonio; Campanale, Cosimo Marco; Fittipaldi, Mario; Giorgino, Riccardo; Quintarelli, Fabio; Satriano, Umberto; Cruciani, Alessandro; Antinolfi, Vincenzo; Di Berardino, Stefano; Costanzo, Davide; Bettini, Ranieri; Mangiameli, Giuseppe; Caricato, Marco; Mottini, Giovanni

    2016-01-01

    Background Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children. Methods We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height2.7 (LVMI2.7) and weight (LVMIw). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI2.7 >51 g/m2.7; (3) LVMIw >3.4 g/weight. Results 40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI2.7 >51 g/m2.7 while 19 children (6%) an LVMIw >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation. Conclusion ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH.

  3. Agreement between clinical and portable EMG/ECG diagnosis of sleep bruxism.

    PubMed

    Castroflorio, T; Bargellini, A; Rossini, G; Cugliari, G; Deregibus, A; Manfredini, D

    2015-10-01

    The aim of this study was to compare clinical sleep bruxism (SB) diagnosis with an instrumental diagnosis obtained with a device providing electromyography/electrocardiography (EMG/ECG) recordings. Forty-five (N = 45) subjects (19 males and 26 females, mean age 28 ± 11 years) were selected among patients referring to the Gnathology Unit of the Dental School of the University of Torino. An expert clinician assessed the presence of SB based on the presence of one or more signs/symptoms (i.e., transient jaw muscle pain in the morning, muscle fatigue at awakening, presence of tooth wear, masseter hypertrophy). Furthermore, all participants underwent an instrumental recording at home with a portable device (Bruxoff; OT Bioelettronica, Torino, Italy) allowing a simultaneous recording of EMG signals from both the masseter muscles as well as heart frequency. Statistical procedures were performed with the software Statistical Package for the Social Science v. 20.0 (SPSS 20.0; IBM, Milan, Italy). Based on the EMG/ECG analysis, 26 subjects (11 males, 15 females, mean age 28 ± 10 years) were diagnosed as sleep bruxers, whilst 19 subjects (7 males, 12 females, mean age 30 ± 10 years) were diagnosed as non-bruxers. The correlation between the clinical and EMG/ECG SB diagnoses was low (ϕ value = 0.250), with a 62.2% agreement (28/45 subjects) between the two approaches (kappa = 0.248). Assuming instrumental EMG/ECG diagnosis as the standard of reference for definite SB diagnosis in this investigation, the false-positive and false-negative rates were unacceptable for all clinical signs/symptoms. In conclusion, findings from clinical assessment are not related with SB diagnosis performed with a portable EMG/ECG recorder.

  4. ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

    PubMed Central

    Creta, Antonio; Campanale, Cosimo Marco; Fittipaldi, Mario; Giorgino, Riccardo; Quintarelli, Fabio; Satriano, Umberto; Cruciani, Alessandro; Antinolfi, Vincenzo; Di Berardino, Stefano; Costanzo, Davide; Bettini, Ranieri; Mangiameli, Giuseppe; Caricato, Marco; Mottini, Giovanni

    2016-01-01

    Background Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children. Methods We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height2.7 (LVMI2.7) and weight (LVMIw). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI2.7 >51 g/m2.7; (3) LVMIw >3.4 g/weight. Results 40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI2.7 >51 g/m2.7 while 19 children (6%) an LVMIw >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation. Conclusion ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH. PMID:27651998

  5. 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

  6. Computed tomography-guided in vivo cardiac orientation and correlation with ECG in individuals without structural heart disease and in age-matched obese and older individuals.

    PubMed

    Sathananthan, Gnalini; Aggarwal, Gunjan; Zahid, Simmi; Byth, Karen; Chik, William; Friedman, Daniel; Thiagalingam, Aravinda

    2015-05-01

    The cardiac axis in a structurally normal heart is influenced by a number of factors. We investigated the anatomical and electrical cardiac axes in middle-aged individuals without structural heart disease and compared this with age-matched obese and older individuals without structural heart disease. A retrospective study of controls included those between 30 and 60 years old with a normal body mass index (BMI), who were then compared with obese individuals between 30 and 60 years old and with individuals more than 60 years old with a normal BMI. The anatomical cardiac axis was determined along the long axis by cardiac computed tomography (CT) and correlated with the electrical cardiac axis on a surface electrocardiogram (ECG) in the frontal plane. A total of 124 patients were included. In the controls (n = 59), the mean CT axis was 38.1° ± 7.8° whilst the mean ECG axis was 51.8° ± 26.6°, Pearson r value 0.12 (P = 0.365). In the obese (n = 36), the mean CT axis was 25.1° ± 6.2° whilst the mean ECG axis was 20.1° ± 23.9°, Pearson r value 0.05 (P = 0.808). In the older group (n = 29), the mean CT axis was 34.4° ± 9.1° whilst the mean ECG axis was 34.4° ± 30.3°, Pearson r value 0.26 (P = 0.209). Obese individuals have a more leftward rotation of both axes than age-matched normals (P <0.0001), which could be secondary to elevation of the diaphragm. Older individuals have a more leftward rotation only of their electrical cardiac axis (P = 0.01), which could be a normal variant or reflect underlying conduction disturbances in this age group.

  7. Pseudoaneurysm of the thoracic aorta sustained during exposure to a tornado diagnosed with ECG-synchronized CT aortography.

    PubMed

    Chakraborty, Amit; von Herrmann, Paul F; Embertson, Ryan E; Landwehr, Kevin P; Winkler, Michael A

    2016-01-01

    A case of a tornado victim with a delayed presentation of injury to the aortic isthmus is discussed. Tornado forces resemble the forces of high energy explosions, and the injuries that can occur as a result of these forces can be bizarre. The patient presented with the unique computed tomography (CT) findings of isolated pseudoaneurysm of the thoracic aorta in the absence of other traumatic injury to the thorax. Equivocal results of the initial CT aortogram (CTA) were confirmed with ECG-synchronized CTA (ECG-CTA), demonstrating the superiority of ECG-CTA as compared to standard CTA. PMID:27317209

  8. Pseudoaneurysm of the thoracic aorta sustained during exposure to a tornado diagnosed with ECG-synchronized CT aortography.

    PubMed

    Chakraborty, Amit; von Herrmann, Paul F; Embertson, Ryan E; Landwehr, Kevin P; Winkler, Michael A

    2016-01-01

    A case of a tornado victim with a delayed presentation of injury to the aortic isthmus is discussed. Tornado forces resemble the forces of high energy explosions, and the injuries that can occur as a result of these forces can be bizarre. The patient presented with the unique computed tomography (CT) findings of isolated pseudoaneurysm of the thoracic aorta in the absence of other traumatic injury to the thorax. Equivocal results of the initial CT aortogram (CTA) were confirmed with ECG-synchronized CTA (ECG-CTA), demonstrating the superiority of ECG-CTA as compared to standard CTA.

  9. Removing ECG Artifact from the Surface EMG Signal Using Adaptive Subtraction Technique

    PubMed Central

    Abbaspour, S; Fallah, A

    2014-01-01

    Background: The electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. Objective: Removing electrocardiogram contamination from electromyogram signals. Methods: In this paper, the clean electromyogram signal, electrocardiogram artifact and electrocardiogram signal were recorded from leg muscles, the pectoralis major muscle of the left side and V4, respectively. After the pre-processing, contaminated electromyogram signal is simulated with a combination of clean electromyogram and electrocardiogram artifact. Then, contaminated electromyogram is cleaned using adaptive subtraction method. This method contains some steps; (1) QRS detection, (2) formation of electrocardiogram template by averaging the electrocardiogram complexes, (3) using low pass filter to remove undesirable artifacts, (4) subtraction. Results: Performance of our method is evaluated using qualitative criteria, power spectrum density and coherence and quantitative criteria signal to noise ratio, relative error and cross correlation. The result of signal to noise ratio, relative error and cross correlation is equal to 10.493, 0.04 and %97 respectively. Finally, there is a comparison between proposed method and some existing methods. Conclusion: The result indicates that adaptive subtraction method is somewhat effective to remove electrocardiogram artifact from contaminated electromyogram signal and has an acceptable result. PMID:25505766

  10. Advances in ambulatory monitoring: regulatory considerations.

    PubMed

    Buckles, David; Aguel, Felipe; Brockman, Randall; Cheng, James; Demian, Cindy; Ho, Charles; Jensen, Donald; Mallis, Elias

    2004-01-01

    Conventional ambulatory electrocardiogram (ECG) (Holter) monitoring involves 2 or 3 surface leads recorded with electrode positions and signal characteristics that are different from diagnostic quality 12-lead ECGs due to the limitations imposed by technology on the ambulatory recorders. The rapid pace of technological development for medical devices, particularly electrocardiography, has now enabled the recording of diagnostic quality 12-lead ECG waveforms for extended time periods. This capability allows Holter recording to become another source for diagnostic 12-lead ECG records on a par with other modalities such as resting ECG and exercise stress testing. Additionally, other diagnostic techniques such as S-T segment analysis and Q-T interval analysis that rely on diagnostic quality waveforms can now be applied. All of these enhancements to the traditional Holter modality have altered the regulatory perspective of these devices, since the enhancements may represent a new intended use for the device.

  11. Advances in ambulatory monitoring: regulatory considerations.

    PubMed

    Buckles, David; Aguel, Felipe; Brockman, Randall; Cheng, James; Demian, Cindy; Ho, Charles; Jensen, Donald; Mallis, Elias

    2004-01-01

    Conventional ambulatory electrocardiogram (ECG) (Holter) monitoring involves 2 or 3 surface leads recorded with electrode positions and signal characteristics that are different from diagnostic quality 12-lead ECGs due to the limitations imposed by technology on the ambulatory recorders. The rapid pace of technological development for medical devices, particularly electrocardiography, has now enabled the recording of diagnostic quality 12-lead ECG waveforms for extended time periods. This capability allows Holter recording to become another source for diagnostic 12-lead ECG records on a par with other modalities such as resting ECG and exercise stress testing. Additionally, other diagnostic techniques such as S-T segment analysis and Q-T interval analysis that rely on diagnostic quality waveforms can now be applied. All of these enhancements to the traditional Holter modality have altered the regulatory perspective of these devices, since the enhancements may represent a new intended use for the device. PMID:15534803

  12. A vector-free ECG interpretation with P, QRS & T waves as unbalanced transitions between stable configurations of the heart electric field during P-R, S-T & T-P segments

    PubMed Central

    2014-01-01

    Since cell membranes are weak sources of electrostatic fields, this ECG interpretation relies on the analogy between cells and electrets. It is here assumed that cell-bound electric fields unite, reach the body surface and the surrounding space and form the thoracic electric field that consists from two concentric structures: the thoracic wall and the heart. If ECG leads measure differences in electric potentials between skin electrodes, they give scalar values that define position of the electric field center along each lead. Repolarised heart muscle acts as a stable positive electric source, while depolarized heart muscle produces much weaker negative electric field. During T-P, P-R and S-T segments electric field is stable, only subtle changes are detectable by skin electrodes. Diastolic electric field forms after ventricular depolarization (T-P segments in the ECG recording). Telediastolic electric field forms after the atria have been depolarized (P-Q segments in the ECG recording). Systolic electric field forms after the ventricular depolarization (S-T segments in the ECG recording). The three ECG waves (P, QRS and T) can then be described as unbalanced transitions of the heart electric field from one stable configuration to the next and in that process the electric field center is temporarily displaced. In the initial phase of QRS, the rapidly diminishing septal electric field makes measured potentials dependent only on positive charges of the corresponding parts of the left and the right heart that lie within the lead axes. If more positive charges are near the "DOWN" electrode than near the "UP" electrode, a Q wave will be seen, otherwise an R wave is expected. Repolarization of the ventricular muscle is dampened by the early septal muscle repolarization that reduces deflection of T waves. Since the "UP" electrode of most leads is near the usually larger left ventricle muscle, T waves are in these leads positive, although of smaller amplitude and longer

  13. A vector-free ECG interpretation with P, QRS & T waves as unbalanced transitions between stable configurations of the heart electric field during P-R, S-T & T-P segments.

    PubMed

    Kurbel, Sven

    2014-01-01

    Since cell membranes are weak sources of electrostatic fields, this ECG interpretation relies on the analogy between cells and electrets. It is here assumed that cell-bound electric fields unite, reach the body surface and the surrounding space and form the thoracic electric field that consists from two concentric structures: the thoracic wall and the heart. If ECG leads measure differences in electric potentials between skin electrodes, they give scalar values that define position of the electric field center along each lead. Repolarised heart muscle acts as a stable positive electric source, while depolarized heart muscle produces much weaker negative electric field. During T-P, P-R and S-T segments electric field is stable, only subtle changes are detectable by skin electrodes.Diastolic electric field forms after ventricular depolarization (T-P segments in the ECG recording). Telediastolic electric field forms after the atria have been depolarized (P-Q segments in the ECG recording). Systolic electric field forms after the ventricular depolarization (S-T segments in the ECG recording). The three ECG waves (P, QRS and T) can then be described as unbalanced transitions of the heart electric field from one stable configuration to the next and in that process the electric field center is temporarily displaced. In the initial phase of QRS, the rapidly diminishing septal electric field makes measured potentials dependent only on positive charges of the corresponding parts of the left and the right heart that lie within the lead axes. If more positive charges are near the "DOWN" electrode than near the "UP" electrode, a Q wave will be seen, otherwise an R wave is expected. Repolarization of the ventricular muscle is dampened by the early septal muscle repolarization that reduces deflection of T waves. Since the "UP" electrode of most leads is near the usually larger left ventricle muscle, T waves are in these leads positive, although of smaller amplitude and longer

  14. ECG criteria for localizing the pulmonary vein origin of spontaneous atrial premature complexes: validation using intracardiac recordings.

    PubMed

    Rajawat, Yadavendra S; Gerstenfeld, Edward P; Patel, Vickas V; Dixit, Sanjay; Callans, David J; Marchlinski, Francis E

    2004-02-01

    We have shown that pacemapping from each of the pulmonary veins reveals unique surface ECG characteristics. However, application of these criteria to spontaneous atrial premature complexes is often difficult because of obscuration by the prior T wave. We hypothesized that the pulmonary vein of origin of spontaneous atrial premature complexes can be determined by measuring characteristics of the P wave whether or not the P wave was superimposed on the prior T wave. We analyzed 58 spontaneous atrial premature complexes of known pulmonary vein origin in 30 patients referred for atrial fibrillation ablation. The origin of all the atrial premature complexes was documented by detailed, intracardiac multipolar catheter mapping. Based on previous work, the criteria for distinguishing right-sided from left-sided pulmonary vein origin of atrial premature complex includes: (1) P wave duration < 120 ms; (2) P wave amplitude in lead I > 0.05 mV; and (3) P wave amplitude in leads II/III > 1.25. The criteria to separate superior from inferior pulmonary veins included the sum of the P wave amplitude in all the inferior leads greater than 0.3 mV. The combination of the P wave duration < 120 ms and the ratio of the P wave amplitude in leads II/III > 1.25, distinguished right-sided from left-sided pulmonary vein origin of spontaneous atrial premature complexes with a sensitivity of 82% and specificity of 100%. The sum of the P wave amplitude in leads II, III, and aVF > 0.3 mV distinguished superior from inferior pulmonary vein of origin with a sensitivity of 39% and specificity of 73%. The pulmonary vein origin of spontaneous atrial premature complexes can often be localized using careful quantitative analysis of the surface ECG despite superimposition of the P wave upon the T wave. Separation of right-sided from left-sided pulmonary vein origin of spontaneous atrial premature complexes can be determined with good specificity and sensitivity, while the ability to distinguish inferior

  15. 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

  16. 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

  17. 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

  18. Optimising diagnostic accuracy with the exercise ECG: opportunities for women and men with stable ischaemic heart disease

    PubMed Central

    Shaw, Leslee J; Xie, Joe X; Phillips, Lawrence M; Goyal, Abhinav; Reynolds, Harmony R; Berman, Daniel S; Picard, Michael H; Bhargava, Balram; Devlin, Gerard; Chaitman, Bernard R

    2016-01-01

    The exercise ECG is an integral part within the evaluation algorithm for diagnosis and risk stratification of patients with stable ischaemic heart disease (SIHD). There is evidence, both older and new, that the exercise ECG can be an effective and cost-efficient option for patients capable of performing at maximal levels of exercise with suitable resting ECG findings. In this review, we will highlight the major dilemmas in interpreting suspected coronary artery disease symptoms in women and identify optimal strategies for employing exercise ECG as a first-line diagnostic test in the SIHD evaluation algorithm. We will highlight current evidence as well as recent guideline statements on this subject. Trial registration number NCT01471522; Pre-results. PMID:27326241

  19. 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

  20. Wearable real-time ecg monitoring with emergency alert system for scuba diving.

    PubMed

    Cibis, Tobias; Groh, Benjamin H; Gatermann, Heike; Leutheuser, Heike; Eskofier, Bjoern M

    2015-01-01

    Medical diagnosis is the first level for recognition and treatment of diseases. To realize fast diagnosis, we propose a concept of a basic framework for the underwater monitoring of a diver's ECG signal, including an alert system that warns the diver of predefined medical emergency situations. The framework contains QRS detection, heart rate calculation and an alert system. After performing a predefined study protocol, the algorithm's accuracy was evaluated with 10 subjects in a dry environment and with 5 subjects in an underwater environment. The results showed that, in 3 out of 5 dives as well as in dry environment, data transmission remained stable. In these cases, the subjects were able to trigger the alert system. The evaluated data showed a clear ECG signal with a QRS detection accuracy of 90 %. Thus, the proposed framework has the potential to detect and to warn of health risks. Further developments of this sample concept can imply an extension for monitoring different biomedical parameters.

  1. Common mode noise cancellation for electrically non-contact ECG measurement system on a chair.

    PubMed

    Keun Kim, Ko; Kyu Lim, Yong; Suk Park, Kwang

    2005-01-01

    Electrically non-contact ECG measurement system on a chair can be applied to a number of various fields for continuous health monitoring in daily life. However, the body is floated electrically for this system due to the capacitive electrodes and the floated body is very sensitive to the external noises or motion artifacts which affect the measurement system as the common mode noise. In this paper, the Driven-Seat-Ground circuit similar to the Driven-Right-Leg circuit is proposed to reduce the common mode noise. The analysis of this equivalent circuit is performed and the output signal waveforms are compared between with Driven-Seat-Ground and with capacitive ground. As the results, the Driven-Seat-Ground circuit improves significantly the properties of the fully capacitive ECG measurement system as the negative feedback.

  2. An ECG electrode-mounted heart rate, respiratory rhythm, posture and behavior recording system.

    PubMed

    Yoshimura, Takahiro; Yonezawa, Yoshiharu; Maki, Hiromichi; Ogawa, Hidekuni; Ninomiya, Ishio; Morton Caldwell, W

    2004-01-01

    R-R interval, respiration rhythm, posture and behavior recording system has been developed for monitoring a patient's cardiovascular regulatory system in daily life. The recording system consists of three ECG chest electrodes, a variable gain instrumentation amplifier, a dual axis accelerometer, a low power 8-bit single-chip microcomputer and a 1024 KB EEPROM. The complete system is mounted on the chest electrodes. R-R interval and respiration rhythm are calculated by the R waves detected from the ECG. Posture and behavior such as walking and running are detected from the body movements recorded by the accelerometer. The detected data are stored by the EEPROM and, after recording, are downloaded to a desktop computer for analysis.

  3. Wearable real-time ecg monitoring with emergency alert system for scuba diving.

    PubMed

    Cibis, Tobias; Groh, Benjamin H; Gatermann, Heike; Leutheuser, Heike; Eskofier, Bjoern M

    2015-01-01

    Medical diagnosis is the first level for recognition and treatment of diseases. To realize fast diagnosis, we propose a concept of a basic framework for the underwater monitoring of a diver's ECG signal, including an alert system that warns the diver of predefined medical emergency situations. The framework contains QRS detection, heart rate calculation and an alert system. After performing a predefined study protocol, the algorithm's accuracy was evaluated with 10 subjects in a dry environment and with 5 subjects in an underwater environment. The results showed that, in 3 out of 5 dives as well as in dry environment, data transmission remained stable. In these cases, the subjects were able to trigger the alert system. The evaluated data showed a clear ECG signal with a QRS detection accuracy of 90 %. Thus, the proposed framework has the potential to detect and to warn of health risks. Further developments of this sample concept can imply an extension for monitoring different biomedical parameters. PMID:26737677

  4. NOTE: Solving the ECG forward problem by means of a meshless finite element method

    NASA Astrophysics Data System (ADS)

    Li, Z. S.; Zhu, S. A.; He, Bin

    2007-07-01

    The conventional numerical computational techniques such as the finite element method (FEM) and the boundary element method (BEM) require laborious and time-consuming model meshing. The new meshless FEM only uses the boundary description and the node distribution and no meshing of the model is required. This paper presents the fundamentals and implementation of meshless FEM and the meshless FEM method is adapted to solve the electrocardiography (ECG) forward problem. The method is evaluated on a single-layer torso model, in which the analytical solution exists, and tested in a realistic geometry homogeneous torso model, with satisfactory results being obtained. The present results suggest that the meshless FEM may provide an alternative for ECG forward solutions.

  5. Implementation of a Data Packet Generator Using Pattern Matching for Wearable ECG Monitoring Systems

    PubMed Central

    Noh, Yun Hong; Jeong, Do Un

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  6. 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.

  7. 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.

  8. 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.

  9. Implementation of a data packet generator using pattern matching for wearable ECG monitoring systems.

    PubMed

    Noh, Yun Hong; Jeong, Do Un

    2014-01-01

    In this paper, a packet generator using a pattern matching algorithm for real-time abnormal heartbeat detection is proposed. The packet generator creates a very small data packet which conveys sufficient crucial information for health condition analysis. The data packet envelopes real time ECG signals and transmits them to a smartphone via Bluetooth. An Android application was developed specifically to decode the packet and extract ECG information for health condition analysis. Several graphical presentations are displayed and shown on the smartphone. We evaluate the performance of abnormal heartbeat detection accuracy using the MIT/BIH Arrhythmia Database and real time experiments. The experimental result confirm our finding that abnormal heart beat detection is practically possible. We also performed data compression ratio and signal restoration performance evaluations to establish the usefulness of the proposed packet generator and the results were excellent. PMID:25029280

  10. A Wearable Healthcare System With a 13.7 μA Noise Tolerant ECG Processor.

    PubMed

    Izumi, Shintaro; Yamashita, Ken; Nakano, Masanao; Kawaguchi, Hiroshi; Kimura, Hiromitsu; Marumoto, Kyoji; Fuchikami, Takaaki; Fujimori, Yoshikazu; Nakajima, Hiroshi; Shiga, Toshikazu; Yoshimoto, Masahiko

    2015-10-01

    To prevent lifestyle diseases, wearable bio-signal monitoring systems for daily life monitoring have attracted attention. Wearable systems have strict size and weight constraints, which impose significant limitations of the battery capacity and the signal-to-noise ratio of bio-signals. This report describes an electrocardiograph (ECG) processor for use with a wearable healthcare system. It comprises an analog front end, a 12-bit ADC, a robust Instantaneous Heart Rate (IHR) monitor, a 32-bit Cortex-M0 core, and 64 Kbyte Ferroelectric Random Access Memory (FeRAM). The IHR monitor uses a short-term autocorrelation (STAC) algorithm to improve the heart-rate detection accuracy despite its use in noisy conditions. The ECG processor chip consumes 13.7 μA for heart rate logging application.

  11. 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

  12. ECG gating of thallium-201 myocardial images: effect on detection of ischemic heart disease

    SciTech Connect

    McKillop, J.H.; Fawcett, H.D.; Baumert, J.E.; McDougall, I.R.; DeBusk, R.F.; Harrison, D.C.; Goris, M.L.

    1981-03-01

    Using the angiographic findings as the standard, we have examined the sensitivity and specificity of ECG-gated static thallium-201 myocardial images in 54 patients undergoing selective coronary arteriography. Gated and nongated images, each in anterior, 45 LAO, and 65 LAO projections, were processed by interpolative background subtraction. They were then analyzed separately by four independent observers who were unaware of patient identity, the results of coronary arteriography, and which studies were gated or nonongated. No significant differences were observed between the gated and ngated images regarding sensitivity or specificity, the detection rate for reversible myocardial ischmia, the accuracy of prediction of arteriographic extent of disease, or the degree of inter-or intraobserver variability. We conclude that ECG-gated acquisition of Tl-201 images does not produce any significant advantages, at least when interpolative background subtraction is used.

  13. 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

  14. Classification of ECG signals using LDA with factor analysis method as feature reduction technique.

    PubMed

    Kaur, Manpreet; Arora, A S

    2012-11-01

    The analysis of ECG signal, especially the QRS complex as the most characteristic wave in ECG, is a widely accepted approach to study and to classify cardiac dysfunctions. In this paper, first wavelet coefficients calculated for QRS complex are taken as features. Next, factor analysis procedures without rotation and with orthogonal rotation (varimax, equimax and quartimax) are used for feature reduction. The procedure uses the 'Principal Component Method' to estimate component loadings. Further, classification has been done with a LDA classifier. The MIT-BIH arrhythmia database is used and five types of beats (normal, PVC, paced, LBBB and RBBB) are considered for analysis. Accuracy, sensitivity and positive predictivity are performance parameters used for comparing performance of feature reduction techniques. Results demonstrate that the equimax rotation method yields maximum average accuracy of 99.056% for unknown data sets among other used methods.

  15. Simultaneous Greedy Analysis Pursuit for compressive sensing of multi-channel ECG signals.

    PubMed

    Avonds, Yurrit; Liu, Yipeng; Van Huffel, Sabine

    2014-01-01

    This paper addresses compressive sensing for multi-channel ECG. Compared to the traditional sparse signal recovery approach which decomposes the signal into the product of a dictionary and a sparse vector, the recently developed cosparse approach exploits sparsity of the product of an analysis matrix and the original signal. We apply the cosparse Greedy Analysis Pursuit (GAP) algorithm for compressive sensing of ECG signals. Moreover, to reduce processing time, classical signal-channel GAP is generalized to the multi-channel GAP algorithm, which simultaneously reconstructs multiple signals with similar support. Numerical experiments show that the proposed method outperforms the classical sparse multi-channel greedy algorithms in terms of accuracy and the single-channel cosparse approach in terms of processing speed.

  16. 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

  17. ECG denoising and fiducial point extraction using an extended Kalman filtering framework with linear and nonlinear phase observations.

    PubMed

    Akhbari, Mahsa; Shamsollahi, Mohammad B; Jutten, Christian; Armoundas, Antonis A; Sayadi, Omid

    2016-02-01

    In this paper we propose an efficient method for denoising and extracting fiducial point (FP) of ECG signals. The method is based on a nonlinear dynamic model which uses Gaussian functions to model ECG waveforms. For estimating the model parameters, we use an extended Kalman filter (EKF). In this framework called EKF25, all the parameters of Gaussian functions as well as the ECG waveforms (P-wave, QRS complex and T-wave) in the ECG dynamical model, are considered as state variables. In this paper, the dynamic time warping method is used to estimate the nonlinear ECG phase observation. We compare this new approach with linear phase observation models. Using linear and nonlinear EKF25 for ECG denoising and nonlinear EKF25 for fiducial point extraction and ECG interval analysis are the main contributions of this paper. Performance comparison with other EKF-based techniques shows that the proposed method results in higher output SNR with an average SNR improvement of 12 dB for an input SNR of -8 dB. To evaluate the FP extraction performance, we compare the proposed method with a method based on partially collapsed Gibbs sampler and an established EKF-based method. The mean absolute error and the root mean square error of all FPs, across all databases are 14 ms and 22 ms, respectively, for our proposed method, with an advantage when using a nonlinear phase observation. These errors are significantly smaller than errors obtained with other methods. For ECG interval analysis, with an absolute mean error and a root mean square error of about 22 ms and 29 ms, the proposed method achieves better accuracy and smaller variability with respect to other methods.

  18. ECG denoising and fiducial point extraction using an extended Kalman filtering framework with linear and nonlinear phase observations.

    PubMed

    Akhbari, Mahsa; Shamsollahi, Mohammad B; Jutten, Christian; Armoundas, Antonis A; Sayadi, Omid

    2016-02-01

    In this paper we propose an efficient method for denoising and extracting fiducial point (FP) of ECG signals. The method is based on a nonlinear dynamic model which uses Gaussian functions to model ECG waveforms. For estimating the model parameters, we use an extended Kalman filter (EKF). In this framework called EKF25, all the parameters of Gaussian functions as well as the ECG waveforms (P-wave, QRS complex and T-wave) in the ECG dynamical model, are considered as state variables. In this paper, the dynamic time warping method is used to estimate the nonlinear ECG phase observation. We compare this new approach with linear phase observation models. Using linear and nonlinear EKF25 for ECG denoising and nonlinear EKF25 for fiducial point extraction and ECG interval analysis are the main contributions of this paper. Performance comparison with other EKF-based techniques shows that the proposed method results in higher output SNR with an average SNR improvement of 12 dB for an input SNR of -8 dB. To evaluate the FP extraction performance, we compare the proposed method with a method based on partially collapsed Gibbs sampler and an established EKF-based method. The mean absolute error and the root mean square error of all FPs, across all databases are 14 ms and 22 ms, respectively, for our proposed method, with an advantage when using a nonlinear phase observation. These errors are significantly smaller than errors obtained with other methods. For ECG interval analysis, with an absolute mean error and a root mean square error of about 22 ms and 29 ms, the proposed method achieves better accuracy and smaller variability with respect to other methods. PMID:26767425

  19. [Development of dynamic ECG acquisition and recording system: review and prospect].

    PubMed

    Li, Suyi; Yang, Meiling; Ding, Mei; Lin, Guangda; Ling, Zhenbao

    2012-02-01

    Dynamic electrocardiography (DCG) or Holter is the best device to detect arrhythmia and can help early detection of some sudden cardiac death risk factors. The acquisition and recording system of the DCG, however, affects the data quality and the patients' comfort directly. This paper reviews the related latest studies, and discusses the importance of new ECG electrode and wireless dynamic monitoring in DCG monitoring field. Moreover, the existed main problems are summarized and classified and the prospects for the development trend are presented.

  20. Synthesize, optimize, analyze, repeat (SOAR): Application of neural network tools to ECG patient monitoring

    SciTech Connect

    Watrous, R.; Towell, G.; Glassman, M.S.

    1995-12-31

    Results are reported from the application of tools for synthesizing, optimizing and analyzing neural networks to an ECG Patient Monitoring task. A neural network was synthesized from a rule-based classifier and optimized over a set of normal and abnormal heartbeats. The classification error rate on a separate and larger test set was reduced by a factor of 2. When the network was analyzed and reduced in size by a factor of 40%, the same level of performance was maintained.

  1. Ultra-Thin Chip Package (UTCP) and stretchable circuit technologies for wearable ECG system.

    PubMed

    Sterken, Tom; Vanfleteren, Jan; Torfs, Tom; de Beeck, Maaike Op; Bossuyt, Frederick; Van Hoof, Chris

    2011-01-01

    A comfortable, wearable wireless ECG monitoring system is proposed. The device is realized using the combination of two proprietary advanced technologies for electronic packaging and interconnection : the UTCP (Ultra-Thin Chip Package) technology and the SMI (Stretchable Mould Interconnect) technology for elastic and stretchable circuits. Introduction of these technologies results in small fully functional devices, exhibiting a significant increase in user comfort compared to devices fabricated with more conventional packaging and interconnection technologies.

  2. Impact of Cardiac Arrhythmia on Velocity Quantification by ECG gated Phase Contrast MRI

    PubMed Central

    Markl, Michael; Fluckiger, Jacob; Lee, Daniel C.; Ng, Jason; Goldberger, Jeffrey J.

    2014-01-01

    Objective To systematically investigate the impact of beat-to-beat variations on ECG gated multi-beat flow imaging with phase contrast (PC) MRI based on real time in-vivo TEE data in patients with known arrhythmia. Methods Real-time 2D Doppler transesophageal echocardiography (TEE) was performed in five patients with atrial fibrillation (4 male, age=64±8.7 years). TEE data provided real-time left atrial (LA) and left ventricular (LV) flow velocities in consecutive cardiac cycles with different RR-interval durations. PC-MRI acquisitions were simulated from the TEE velocity measures by constructing time-resolved k-space data for segmented sampling schemes typically used for ECG gated 2D PC MRI. Each simulation was repeated 100 times to minimize effects from data that may be weighted to a particular beat in the center of k-space. The resulting LA and LV velocities were compared to the average TEE velocities and data from individual cardiac cycles. Results Despite beat-to-beat variations velocities in TEE data, ECG gated flow imaging with MRI could reproduce persistent average LA and LV mean velocities within 7.0–7.4% compared to TEE. Conclusions PC-MRI velocity measurements in patients with varying R-R interval durations are not significantly different from time-averaged real-time velocity data for a typical segmented k-space data acquisition schemes. Though beat-to-beat variations in atrial velocities that were observed with TEE cannot be detected with ECG gated multi-beat PC MRI, it can reliably assess average flow patterns across multiple beats PMID:25978593

  3. ECG characterization of paroxysmal atrial fibrillation: parameter extraction and automatic diagnosis algorithm.

    PubMed

    Ros, E; Mota, S; Fernández, F J; Toro, F J; Bernier, J L

    2004-12-01

    Paroxysmal atrial fibrillation (PAF) is one of the most common heart arrhythmias. It is very difficult to detect unless an explicit Atrial Fibrillation episode occurs during the exploration. The present paper describes a number of low level parameters extracted from ECG traces where no Atrial Fibrillation process is present. The ability of this parameter set to characterize PAF patients is studied and discussed. Based on these parameters a modular automatic classification algorithm for PAF diagnosis is developed and evaluated. PMID:15518652

  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. 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.

  8. 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

  9. 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.

  10. Wavelet-based ECG data compression system with linear quality control scheme.

    PubMed

    Ku, Cheng-Tung; Hung, King-Chu; Wu, Tsung-Ching; Wang, Huan-Sheng

    2010-06-01

    Maintaining reconstructed signals at a desired level of quality is crucial for lossy ECG data compression. Wavelet-based approaches using a recursive decomposition process are unsuitable for real-time ECG signal recoding and commonly obtain a nonlinear compression performance with distortion sensitive to quantization error. The sensitive response is caused without compromising the influences of word-length-growth (WLG) effect and unfavorable for the reconstruction quality control of ECG data compression. In this paper, the 1-D reversible round-off nonrecursive discrete periodic wavelet transform is applied to overcome the WLG magnification effect in terms of the mechanisms of error propagation resistance and significant normalization of octave coefficients. The two mechanisms enable the design of a multivariable quantization scheme that can obtain a compression performance with the approximate characteristics of linear distortion. The quantization scheme can be controlled with a single control variable. Based on the linear compression performance, a linear quantization scale prediction model is presented for guaranteeing reconstruction quality. Following the use of the MIT-BIH arrhythmia database, the experimental results show that the proposed system, with lower computational complexity, can obtain much better reconstruction quality control than other wavelet-based methods.

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Sudden cardiac arrest risk stratification based on 24-hour Holter ECG statistics.

    PubMed

    Kasahara, Keisuke; Shiobara, Masahito; Nakamura, Saya; Yamashiro, Koichiro; Yana, Kazuo; Ono, Takuya

    2015-08-01

    This study examined the feasibility of using indices obtained from a long term Holter ECG record for sudden cardiac arrest (SCA) risk stratification. The ndices tested were the QT-RR interval co-variability and the alternans ratio percentile (ARP(θ)) which is defined as the θ(th) percentile of alternans ratios over a 24 hour period. The QT-RR interval co-variabilities are evaluated by the serial correlation coefficient between QT and RR trend sequences (QTRC). Previously reported Kalman filter technique and a simple smoothing spline method for the trend estimation are compared. Parameter θ in the alternans ratio percentile index was optimized to achieve the best classification accuracy. These indices were estimated from 26 cardiovascular outpatients for Holter ECG record. Patients were classified into high and low risk groups according to their clinical diagnosis, and the obtained indices were compared with those of 25 control subjects. A risk stratification using the two indices QTRC and ARP(θ) yielded an average sensitivity of 0.812 and a specificity of 0.925. The sensitivities and specificities of all three categories exceeded 0.8 except for the sensitivity to detect the high-risk patient group. Other short-term ECG parameters may need to be incorporated in order to improve the sensitivity.

  16. A novel feature extracting method of QRS complex classification for mobile ECG signals

    NASA Astrophysics Data System (ADS)

    Zhu, Lingyun; Wang, Dong; Huang, Xianying; Wang, Yue

    2007-12-01

    The conventional classification parameters of QRS complex suffer from larger activity rang of patients and lower signal to noise ratio in mobile cardiac telemonitoring system and can not meet the identification needs of ECG signal. Based on individual sinus heart rhythm template built with mobile ECG signals in time window, we present semblance index to extract the classification features of QRS complex precisely and expeditiously. Relative approximation r2 and absolute error r3 are used as estimating parameters of semblance between testing QRS complex and template. The evaluate parameters corresponding to QRS width and types are demonstrated to choose the proper index. The results show that 99.99 percent of the QRS complex for sinus and superventricular ECG signals can be distinguished through r2 but its average accurate ratio is only 46.16%. More than 97.84 percent of QRS complexes are identified using r3 but its accurate ratio to the sinus and superventricular is not better than r2. By the feature parameter of width, only 42.65 percent of QRS complexes are classified correctly, but its accurate ratio to the ventricular is superior to r2. To combine the respective superiority of three parameters, a nonlinear weighing computation of QRS width, r2 and r3 is introduced and the total classification accuracy up to 99.48% by combing indexes.

  17. A robust and simple security extension for the medical standard SCP-ECG.

    PubMed

    Rubio, Oscar J; Alesanco, Alvaro; García, José

    2013-02-01

    This paper proposes a SCP-ECG security extension after having analyzed the features of this standard, its security requirements and the current measures implemented by other medical protocols. Our approach permits SCP-ECG files to be stored safely and proper access to be granted (or denied) to users for different purposes: interpretation of the test, consultation, clinical research or teaching. The access privileges are scaled by means of role-based profiles supported by cryptographic elements (ciphering, digital certificates and digital signatures). These elements are arranged as metadata into a new section which extends the protocol and protects the remaining sections. The application built to implement this approach has been extensively tested, showing its capacity to authenticate users and to protect the integrity of files and the privacy of sensitive data, with a low impact on file size and access time. In addition, this solution is compatible with any version of the SCP-ECG and can be easily integrated into e-health platforms.

  18. Comparison of sensor arrangements of MCG and ECG with respect to information content

    NASA Astrophysics Data System (ADS)

    Nalbach, M.; Dössel, O.

    2002-08-01

    Magnetocardiography (MCG) deals with the measurement of biomagnetic fields due to electrical excitation of the heart. The solution of the inverse problem of MCG and electrocardiography (ECG) is the reconstruction and visualization of the excitation process. The calculation is performed from MCG data recorded by multichannel systems. For a maximum of information content an optimized magnetometer arrangement is determined which is not realized at present. The information content with respect to imaging of bioelectric sources is defined by the slope of the singular values, respective the signal-to-noise ratio and the dimension of the nullspace. Reconstruction errors due to modelling errors are not taken into account in this work. The nullspace describes the set of non-detectable source patterns in MCG and ECG. A conventional commercial sensor arrangement will be compared to an improved sensor composition. Recent publications show evidence that MCG contains more or different diagnostic information in cardiac arrhythmia and infarction diagnosis than electrocardiography. Therefore, first results of a general comparison of the information content of MCG and ECG are presented.

  19. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    NASA Astrophysics Data System (ADS)

    O'Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  20. [Detection of Heart Rate of Fetal ECG Based on STFT and BSS].

    PubMed

    Wang, Xu; Cai, Kun

    2016-01-01

    Changes in heart rate of fetal is function regulating performance of the circulatory system and the central nervous system, it is significant to detect heart rate of fetus in perinatal fetal. This paper puts forward the fetal heart rate detection method based on short time Fourier transform and blind source separation. First of all, the mixed ECG signal was preprocessed, and then the wavelet transform technique was used to separate the fetal ECG signal with noise from mixed ECG signal, after that, the short-time Fourier transform and the blind separation were carried on it, and then calculated the correlation coefficient of it, Finally, An independent component that it has strongest correlation with the original signal was selected to make FECG peak detection and calculated the fetal instantaneous heart rate. The experimental results show that the method can improve the detection rate of the FECG peak (R), and it has high accuracy in fixing peak(R) location in the case of low signal-noise ratio. PMID:27197491