Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745542
M. Risk, D. Ślȩzak, P. Turjanski, A. Panelli, R. Taborda, G. Marshall
The spectral analysis of heart rate variability, based on the Fourier transform, needs even sampled data. The objectives of this study were to develop an interpolation method based on multi rate FIR filters, and then to implement this method for parallel processing machines. A total of three data sets were used: a) simulated heart rate with an IPFM model, b) autonomic blockage database (both pharmacological and postural), and c) long term Holter studies (recordings of 24 hours). Spectral analysis, for the three data sets, was processed for both interpolation using FIR filters and cubic splines, the results for Bland and Altman analysis for low frequency band, showed a difference of -47plusmn131 ms2; then for the high frequency band, the difference was 3plusmn48 ms2. The presented method of time series calculation, using FIR filters, probed to be equivalent for both simulated and real data, and is suitable for parallel programming implementation.
{"title":"Time series calculation of heart rate using multi rate FIR filters","authors":"M. Risk, D. Ślȩzak, P. Turjanski, A. Panelli, R. Taborda, G. Marshall","doi":"10.1109/CIC.2007.4745542","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745542","url":null,"abstract":"The spectral analysis of heart rate variability, based on the Fourier transform, needs even sampled data. The objectives of this study were to develop an interpolation method based on multi rate FIR filters, and then to implement this method for parallel processing machines. A total of three data sets were used: a) simulated heart rate with an IPFM model, b) autonomic blockage database (both pharmacological and postural), and c) long term Holter studies (recordings of 24 hours). Spectral analysis, for the three data sets, was processed for both interpolation using FIR filters and cubic splines, the results for Bland and Altman analysis for low frequency band, showed a difference of -47plusmn131 ms2; then for the high frequency band, the difference was 3plusmn48 ms2. The presented method of time series calculation, using FIR filters, probed to be equivalent for both simulated and real data, and is suitable for parallel programming implementation.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114782999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745566
L. Lehman, T. H. Kyaw, G. Clifford, R. Mark
We describe a novel search engine that is capable of rapid execution of queries concerning changes in the gradients and absolute (and relative) values of multiple irregularly sampled and asynchronous physiological parameters over many time scales. The search engine enables search criteria for multiple physiological parameters using gradient bounds, rates of change, and threshold breeches over various time scales. Multiple signals can be searched and combined in a Boolean manner to form complex queries. Pre-computed ranges and multi-scale gradients are used to significantly reduce the search time for locating temporal events. We have implemented the search engine in MATLAB and tested the algorithm on a massive multi-parameter intensive care unit database (MIMIC II). To illustrate the use of our search approach, a set of numerical search criteria were developed by clinicians to locate evidence for important pathophysiological conditions.
{"title":"A temporal search engine for a massive multi-parameter clinical information database","authors":"L. Lehman, T. H. Kyaw, G. Clifford, R. Mark","doi":"10.1109/CIC.2007.4745566","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745566","url":null,"abstract":"We describe a novel search engine that is capable of rapid execution of queries concerning changes in the gradients and absolute (and relative) values of multiple irregularly sampled and asynchronous physiological parameters over many time scales. The search engine enables search criteria for multiple physiological parameters using gradient bounds, rates of change, and threshold breeches over various time scales. Multiple signals can be searched and combined in a Boolean manner to form complex queries. Pre-computed ranges and multi-scale gradients are used to significantly reduce the search time for locating temporal events. We have implemented the search engine in MATLAB and tested the algorithm on a massive multi-parameter intensive care unit database (MIMIC II). To illustrate the use of our search approach, a set of numerical search criteria were developed by clinicians to locate evidence for important pathophysiological conditions.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116612516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745437
S. Jacquir, S. Binczak, M. Rossé, D. Vandroux, G. Laurent, P. Athias, J. Bilbault
To provide further insights into the impulse propagation between cardiac myocytes, we performed multiparametric studies of excitation spread with cellular resolution in confluent monolayers of cultured cardiomyocytes (CM). Simultaneous paired intracellular recordings of action potentials in two individual CM revealed slight periodic spontaneous advances/delays in the interspike time lag. Multisite field potential recordings performed with microelectrode arrays (MEA) confirmed random and iterative cycle-to-cycle changes in the direction of excitation spread. These local spontaneous variations in the cardiac impulse propagation pathways may be a safety process protecting against microscopically discontinuous conduction, and abnormality of this natural process could contribute to the genesis of some heart arrhythmias.
{"title":"Multisite field potential recordings and analysis of the impulse propagation pattern in cardiac cells culture","authors":"S. Jacquir, S. Binczak, M. Rossé, D. Vandroux, G. Laurent, P. Athias, J. Bilbault","doi":"10.1109/CIC.2007.4745437","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745437","url":null,"abstract":"To provide further insights into the impulse propagation between cardiac myocytes, we performed multiparametric studies of excitation spread with cellular resolution in confluent monolayers of cultured cardiomyocytes (CM). Simultaneous paired intracellular recordings of action potentials in two individual CM revealed slight periodic spontaneous advances/delays in the interspike time lag. Multisite field potential recordings performed with microelectrode arrays (MEA) confirmed random and iterative cycle-to-cycle changes in the direction of excitation spread. These local spontaneous variations in the cardiac impulse propagation pathways may be a safety process protecting against microscopically discontinuous conduction, and abnormality of this natural process could contribute to the genesis of some heart arrhythmias.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123833409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745611
N. Bachner, D. Adam, M. Leitman, Z. Vered
Functional echocardiographic imaging, based on speckle tracking, has recently gained widespread use. It provides valuable clinical information, but only the longitudinal or circumferential strains are provided. Assessing these measures across the wall has immense diagnostic information. The purpose of this study was to employ a novel technique that allows measuring the left ventricular transmural kinematics in normal subjects. A novel smoothing technique was developed for a speckle tracking imaging program, called 2D-strain, to achieve spatial transmural resolution analysis, and then applied to standard echocardiographic cines. The results show heterogeneity of the left ventricular rotation and circumferential strain across the wall, with large values for the inner layer, and smaller ones for the outer layer. Using standard echocardiography, transmural analysis is feasible, and it may provide early diagnosis of different pathologies that were difficult to attain before.
{"title":"Ultrasound echocardiographic assessment of transmural inhomogeneity of the left ventricular contraction during the heart cycle","authors":"N. Bachner, D. Adam, M. Leitman, Z. Vered","doi":"10.1109/CIC.2007.4745611","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745611","url":null,"abstract":"Functional echocardiographic imaging, based on speckle tracking, has recently gained widespread use. It provides valuable clinical information, but only the longitudinal or circumferential strains are provided. Assessing these measures across the wall has immense diagnostic information. The purpose of this study was to employ a novel technique that allows measuring the left ventricular transmural kinematics in normal subjects. A novel smoothing technique was developed for a speckle tracking imaging program, called 2D-strain, to achieve spatial transmural resolution analysis, and then applied to standard echocardiographic cines. The results show heterogeneity of the left ventricular rotation and circumferential strain across the wall, with large values for the inner layer, and smaller ones for the outer layer. Using standard echocardiography, transmural analysis is feasible, and it may provide early diagnosis of different pathologies that were difficult to attain before.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122173424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745547
P. Bonizzi, V. Zarzoso, Olivier Meste
Up to now the functioning of the Atrio-Ventricular Junction (AVJ) during Atrial Fibrillation (AF) is still not completely understood. To shed some light on the AVJ behavior during AF episodes, this study analyses the existence of a possible relationship between the occurrence of a heart beat and the power of the atrial activity (AA) preceding this heart beat in an electrocardiogram (ECG) signal. AA power is measured in the interval of the ECG between the onset of the heart beat under analysis and the ending of the previous heart beat (T-Q interval). Our analysis has shown a difference in the distributions of AA power versus cardiac cycle length (RR interval on the ECG) between healthy and pathological subjects. In particular, a negative trend between these two parameters is discovered in pathological subjects. This negative relation shows a possible coherence between power arriving at the AVJ and the triggering of the heart beat, which is in line with the assumptions made in the quantitative model for the ventricular response during AF by Cohen.
{"title":"Atrio-Ventricular Junction behaviour during Atrial Fibrillation","authors":"P. Bonizzi, V. Zarzoso, Olivier Meste","doi":"10.1109/CIC.2007.4745547","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745547","url":null,"abstract":"Up to now the functioning of the Atrio-Ventricular Junction (AVJ) during Atrial Fibrillation (AF) is still not completely understood. To shed some light on the AVJ behavior during AF episodes, this study analyses the existence of a possible relationship between the occurrence of a heart beat and the power of the atrial activity (AA) preceding this heart beat in an electrocardiogram (ECG) signal. AA power is measured in the interval of the ECG between the onset of the heart beat under analysis and the ending of the previous heart beat (T-Q interval). Our analysis has shown a difference in the distributions of AA power versus cardiac cycle length (RR interval on the ECG) between healthy and pathological subjects. In particular, a negative trend between these two parameters is discovered in pathological subjects. This negative relation shows a possible coherence between power arriving at the AVJ and the triggering of the heart beat, which is in line with the assumptions made in the quantitative model for the ventricular response during AF by Cohen.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124947499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745563
M. Ghasemi, A. Jalali, H. Sadabadi, M. Atarod, H. Golbayani, P. Ghorbanian, A. Ghaffari
Hypothesis/Objective: The aim of this study is to characterize the location and extent of moderate to large, relatively compact infarcts using ECG evidence. Method: In this paper, we proposed a method on the basis of vectorcardiography which assumes that heart vector is proportional to relevant active depolarization area(s). To examine our ideas, we used the normal VCG which includes the information of location, amplitude, and direction of heart vector at any instant. The model based comparison of cases under study and relevant normal VCGs gives region i.e. segment(s) and depth i.e. extent of myocardial infarction. Results and Conclusion: We evaluated the method on CinC/Physionet Challenge 2007 database. In our final entry the scores of EPD equal to 32 (ranked 3rd), SO equal to 0.933 (ranked 3rd) and CED equal to 1 (ranked 1st) are achieved. It also ranked the third among the other methods proposed to CinC/Physionet Challenge 2007.
{"title":"Electrocardiographic imaging of myocardial infarction using heart vector analysis","authors":"M. Ghasemi, A. Jalali, H. Sadabadi, M. Atarod, H. Golbayani, P. Ghorbanian, A. Ghaffari","doi":"10.1109/CIC.2007.4745563","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745563","url":null,"abstract":"Hypothesis/Objective: The aim of this study is to characterize the location and extent of moderate to large, relatively compact infarcts using ECG evidence. Method: In this paper, we proposed a method on the basis of vectorcardiography which assumes that heart vector is proportional to relevant active depolarization area(s). To examine our ideas, we used the normal VCG which includes the information of location, amplitude, and direction of heart vector at any instant. The model based comparison of cases under study and relevant normal VCGs gives region i.e. segment(s) and depth i.e. extent of myocardial infarction. Results and Conclusion: We evaluated the method on CinC/Physionet Challenge 2007 database. In our final entry the scores of EPD equal to 32 (ranked 3rd), SO equal to 0.933 (ranked 3rd) and CED equal to 1 (ranked 1st) are achieved. It also ranked the third among the other methods proposed to CinC/Physionet Challenge 2007.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127675582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745482
M.G. Smyrnakis, D.J. Evans
In this paper we present a Bayesian inference Multilayer Perceptron (MLP) which was used to classify the events of the Long Term ST Database (LTSTDB) as ischaemic or non-ischaemic episodes with an accuracy of 89.1%, sensitivity of 82.3% and specificity of 91.2% when the accuracy of the winning paper was 90.7%. The Automatic Relevance Determination (ARD) method was used to identify which of the extracted features that were used as input in the Bayesian inference MLP were the most important with respect to the models performance. ARD indicated that DeltaT, a combination of the ST deviation and the duration of the episode, inspired from Langley et al., was the most important feature for determining Ischaemic episodes, given the data. A simple MLP which had as input variable of only DeltaT was trained to verify the results of the ARD method. The classification accuracy was 85.8% on the test set. We can conclude from the results that the most important extracted feature was DeltaT.
{"title":"Classifying ischemic events using a Bayesian inference Multilayer Perceptron and input variable evaluation using automatic relevance determination","authors":"M.G. Smyrnakis, D.J. Evans","doi":"10.1109/CIC.2007.4745482","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745482","url":null,"abstract":"In this paper we present a Bayesian inference Multilayer Perceptron (MLP) which was used to classify the events of the Long Term ST Database (LTSTDB) as ischaemic or non-ischaemic episodes with an accuracy of 89.1%, sensitivity of 82.3% and specificity of 91.2% when the accuracy of the winning paper was 90.7%. The Automatic Relevance Determination (ARD) method was used to identify which of the extracted features that were used as input in the Bayesian inference MLP were the most important with respect to the models performance. ARD indicated that DeltaT, a combination of the ST deviation and the duration of the episode, inspired from Langley et al., was the most important feature for determining Ischaemic episodes, given the data. A simple MLP which had as input variable of only DeltaT was trained to verify the results of the ARD method. The classification accuracy was 85.8% on the test set. We can conclude from the results that the most important extracted feature was DeltaT.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127707445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745408
Joey F. A. Ubachs, A. Gorgels, E. Hedstrom, H. Arheden, R. Selvester, S. Knippenberg, G. Wagner, H. Engblom
The aim of the present study was to test the hypothesis that perfusion SPECT, estimation of regional wall thickening using MRI and the distribution of ST changes on the admission ECG display similar localization of the MaR in patients with reperfused first-time MI. Eleven patients with first-time MI with ST-elevation underwent percutaneous coronary intervention (PCI), SPECT imaging within 3 hours of the PCI and Cardiac MRI the day after admission. All images were presented in polar plots and compared with polar plots generated from the initial ECG's, based upon ST-changes. Comparison of the displays reveals similarity of location of myocardium at risk by all three methods in 73% of the patients, between SPECT and ECG in 91% of the patients, and between SPECT and wall thickening by MRI in 73% of the patient.
{"title":"Location of myocardium at risk in comparison between single photon emission computed tomography, magnetic resonance imaging and electrocardiography","authors":"Joey F. A. Ubachs, A. Gorgels, E. Hedstrom, H. Arheden, R. Selvester, S. Knippenberg, G. Wagner, H. Engblom","doi":"10.1109/CIC.2007.4745408","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745408","url":null,"abstract":"The aim of the present study was to test the hypothesis that perfusion SPECT, estimation of regional wall thickening using MRI and the distribution of ST changes on the admission ECG display similar localization of the MaR in patients with reperfused first-time MI. Eleven patients with first-time MI with ST-elevation underwent percutaneous coronary intervention (PCI), SPECT imaging within 3 hours of the PCI and Cardiac MRI the day after admission. All images were presented in polar plots and compared with polar plots generated from the initial ECG's, based upon ST-changes. Comparison of the displays reveals similarity of location of myocardium at risk by all three methods in 73% of the patients, between SPECT and ECG in 91% of the patients, and between SPECT and wall thickening by MRI in 73% of the patient.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"280 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120978673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745490
J. Couderc, S. Kaab, M. Hinterseer, S. McNitt, X. Xia, A. Fossa, B. Beckmann, S. Polonsky, W. Zareba
Assessing the propensity of an individual to drug-induced arrhythmias when exposed to a QT-prolonging drug is challenging because baseline QT prolongation has limited predictive value. In this study, we investigated the role of computerized ECG parameters quantifying T-wave morphology for the identification of individuals who developed drug-induced torsades de pointes (TdPs). In 34 patients, 5-minute digital ECGs have been acquired at baseline and during sotalol challenge. Seventeen of these patients had a history of drug-induced TdPs. We identified specific baseline features of the T-waves common to patients with history of TdPs. The sotalol-induced changes of T-wave morphologies were also different between the two groups suggesting that ECGs may provide relevant information for the identification of patients with an increased propensity to TdPs.
{"title":"Investigating the role of ventricular repolarization morphology in surface ECGs for identifying patients with a history of drug-induced arrhythmias","authors":"J. Couderc, S. Kaab, M. Hinterseer, S. McNitt, X. Xia, A. Fossa, B. Beckmann, S. Polonsky, W. Zareba","doi":"10.1109/CIC.2007.4745490","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745490","url":null,"abstract":"Assessing the propensity of an individual to drug-induced arrhythmias when exposed to a QT-prolonging drug is challenging because baseline QT prolongation has limited predictive value. In this study, we investigated the role of computerized ECG parameters quantifying T-wave morphology for the identification of individuals who developed drug-induced torsades de pointes (TdPs). In 34 patients, 5-minute digital ECGs have been acquired at baseline and during sotalol challenge. Seventeen of these patients had a history of drug-induced TdPs. We identified specific baseline features of the T-waves common to patients with history of TdPs. The sotalol-induced changes of T-wave morphologies were also different between the two groups suggesting that ECGs may provide relevant information for the identification of patients with an increased propensity to TdPs.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121476113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1109/CIC.2007.4745571
A. Khandoker, Y. Kimura, T. Ito, M. Palaniswami
Fetal ECG and Doppler ultrasound signals provide clinically significant information concerning the physiological state of a fetus. In this study, we propose a non-invasive system to recognize the timings of fetal cardiac events on the basis of analysis of fetal ECG and Doppler ultrasound signal together. Fetal ECG was extracted from transabdominal ECG (10 normal subjects, 38-41 weeks of gestation) using blind source separation with the reference signal. Multiresolution wavelet analysis enabled the frequency contents of the Doppler signals to be linked to the opening and closing of the heartpsilas valves (Aortic and mitral). The time intervals from R peak of fetal ECG to opening and closing of aortic valve were found to be 99.16plusmn22.07 (msec) and 222.70plusmn21.83 (msec) respectively. The time intervals from R peak to opening and closing of mitral valve were found to be 305.32plusmn22.71 (msec) and 37.84plusmn18.23 (msec) respectively.
{"title":"Non-invasive determination of electromechanical time intervals of cardiac cycle using abdominal ECG and Doppler ultrasound signals from fetal hearts","authors":"A. Khandoker, Y. Kimura, T. Ito, M. Palaniswami","doi":"10.1109/CIC.2007.4745571","DOIUrl":"https://doi.org/10.1109/CIC.2007.4745571","url":null,"abstract":"Fetal ECG and Doppler ultrasound signals provide clinically significant information concerning the physiological state of a fetus. In this study, we propose a non-invasive system to recognize the timings of fetal cardiac events on the basis of analysis of fetal ECG and Doppler ultrasound signal together. Fetal ECG was extracted from transabdominal ECG (10 normal subjects, 38-41 weeks of gestation) using blind source separation with the reference signal. Multiresolution wavelet analysis enabled the frequency contents of the Doppler signals to be linked to the opening and closing of the heartpsilas valves (Aortic and mitral). The time intervals from R peak of fetal ECG to opening and closing of aortic valve were found to be 99.16plusmn22.07 (msec) and 222.70plusmn21.83 (msec) respectively. The time intervals from R peak to opening and closing of mitral valve were found to be 305.32plusmn22.71 (msec) and 37.84plusmn18.23 (msec) respectively.","PeriodicalId":406683,"journal":{"name":"2007 Computers in Cardiology","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122924025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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