0000000000226461

AUTHOR

Ulrike Richter

showing 3 related works from this author

Propagation pattern analysis during atrial fibrillation based on the adaptive group LASSO.

2012

The present study introduces sparse modeling for the estimation of propagation patterns in intracardiac atrial fibrillation (AF) signals. The estimation is based on the partial directed coherence (PDC) function, derived from fitting a multivariate autoregressive model to the observed signals. A sparse optimization method is proposed for estimation of the model parameters, namely, the adaptive group least absolute selection and shrinkage operator (aLASSO). In simulations aLASSO was found superior to the commonly used least-squares (LS) estimation with respect to estimation performance. The normalized error between the true and estimated model parameters dropped from 0.200.04 for LS estimatio…

Normalization (statistics)Computer scienceBiomedical EngineeringHealth InformaticsGroup lassoSensitivity and SpecificityPattern Recognition AutomatedHeart Conduction SystemStatisticsAtrial FibrillationCoherence (signal processing)AnimalsHumansComputer SimulationDiagnosis Computer-AssistedTime series1707ShrinkageSparse matrixPropagation patternModels CardiovascularReproducibility of ResultsElectroencephalographySignal ProcessingSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaAlgorithmAlgorithmsAnnual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
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A Novel Approach to Propagation Pattern Analysis in Intracardiac Atrial Fibrillation Signals

2010

The purpose of this study is to investigate propagation patterns in intracardiac signals recorded during atrial fibrillation (AF) using an approach based on partial directed coherence (PDC), which evaluates directional coupling between multiple signals in the frequency domain. The PDC is evaluated at the dominant frequency of AF signals and tested for significance using a surrogate data procedure specifically designed to assess causality. For significantly coupled sites, the approach allows also to estimate the delay in propagation. The methods potential is illustrated with two simulation scenarios based on a detailed ionic model of the human atrial myocyte as well as with real data recordi…

Frequency analysiComputer scienceBiomedical EngineeringElectrogramAction PotentialsIntracardiac injectionPattern Recognition AutomatedSurrogate datalaw.inventionHeart Conduction SystemlawAtrial FibrillationmedicineHumansCoherence (signal processing)Computer SimulationDiagnosis Computer-AssistedSimulationFrequency analysisbusiness.industryBody Surface Potential MappingPartial directed coherenceModels CardiovascularPropagation patternAtrial fibrillationPattern recognitionAtrial arrhythmiamedicine.diseaseInformation engineeringMappingFrequency domainSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaGranger causalityMultivariate autoregressive modelingArtificial intelligencebusinessSimulationAnnals of Biomedical Engineering
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Propagation pattern analysis during atrial fibrillation based on sparse modeling.

2012

In this study, sparse modeling is introduced for the estimation of propagation patterns in intracardiac atrial fibrillation (AF) signals. The estimation is based on the partial directed coherence function, derived from fitting a multivariate autoregressive model to the observed signal using least-squares (LS) estimation. The propagation pattern analysis incorporates prior information on sparse coupling as well as the distance between the recording sites. Two optimization methods are employed for estimation of the model parameters, namely, the adaptive group least absolute selection and shrinkage operator (aLASSO), and a novel method named the distance-adaptive group LASSO (dLASSO). Using si…

Normalization (statistics)Computer scienceAtrial fibrillation (AF)Biomedical EngineeringSignalPattern Recognition AutomatedElectrocardiographyelectrogramgroup least absolute selection and shrinkage operator (LASSO)Operator (computer programming)StatisticsAtrial FibrillationHumansComputer SimulationSelection (genetic algorithm)ShrinkageSignal processingNoise (signal processing)partial directed coherence (PDC)Models CardiovascularSignal Processing Computer-Assistedpropagation pattern analysiFrequency domainSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaPattern recognition (psychology)AlgorithmAlgorithmsIEEE transactions on bio-medical engineering
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