Search results for "RECOGNITION"

showing 10 items of 3607 documents

A method for quantifying atrial fibrillation organization based on wave-morphology similarity

2002

A new method for quantifying the organization of single bipolar electrograms recorded in the human atria during atrial fibrillation (AF) is presented. The algorithm relies on the comparison between pairs of local activation waves (LAWs) to estimate their morphological similarity, and returns a regularity index (/spl rho/) which measures the extent of repetitiveness over time of the detected activations. The database consisted of endocardial data from a multipolar basket catheter during AF and intraatrial recordings during atrial flutter. The index showed maximum regularity (/spl rho/=1) for all atrial flutter episodes and decreased significantly when increasing AF complexity as defined by W…

Signal processingBundle of Hismedicine.medical_specialtyMorphological similarityAtrial fibrillation (AF)Biomedical EngineeringSensitivity and SpecificityPattern Recognition AutomatedElectrocardiographySimilarity (network science)Heart RateInternal medicineAtrial Fibrillationotorhinolaryngologic diseasesmedicineHumansClinical treatmentWaveform morphologyMathematicsmedicine.diagnostic_testMinimum distanceModels CardiovascularReproducibility of ResultsSignal Processing Computer-AssistedAtrial fibrillationEndocardial signalmedicine.diseaseTachyarrhythmia organizationCardiologysense organsRhythm classificationBasket catheterElectrocardiographyAlgorithmsAtrial flutterBiomedical engineeringIEEE Transactions on Biomedical Engineering
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A fast recursive algorithm to compute local axial moments

2001

The paper describes a fast algorithm to compute local axial moments used in the algorithm of discrete symmetry transform (DST). The basic idea is grounded on fast recursive implementation of respective linear filters by using the so-called primitive kernel functions since the moment computation can be performed in the framework of linear filtering. The main result is that the computation of the local axial moments is independent of the kernel size, i.e. of the order O(1) per data point (pixel). This result is of relevance whenever the DST is used to face with real time computer vision problems. The experimental results confirm the time complexity predicted by the theory.

Signal processingComputationMoment (mathematics)Control and Systems EngineeringFace (geometry)Signal ProcessingPoint (geometry)Computer Vision and Pattern RecognitionElectrical and Electronic EngineeringTime complexityAlgorithmSoftwareLinear filterMathematicsDiscrete symmetrySignal Processing
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An Automatic System for the Analysis and Classification of Human Atrial Fibrillation Patterns from Intracardiac Electrograms

2008

This paper presents an automatic system for the analysis and classification of atrial fibrillation (AF) patterns from bipolar intracardiac signals. The system is made up of: 1) a feature- extraction module that defines and extracts a set of measures potentially useful for characterizing AF types on the basis of their degree of organization; 2) a feature-selection module (based on the Jeffries-Matusita distance and a branch and bound search algorithm) identifying the best subset of features for discriminating different AF types; and 3) a support vector machine technique-based classification module that automatically discriminates the AF types according to the Wells' criteria. The automatic s…

Signal processingComputer scienceFeature extractionBiomedical EngineeringFeature extraction and selectionFeature selectionSensitivity and SpecificityIntracardiac injectionPattern Recognition AutomatedArtificial IntelligenceSearch algorithmAtrial FibrillationmedicineHumansDiagnosis Computer-AssistedIntracardiac ElectrogramArrhythmia organizationSignal processingmedicine.diagnostic_testbusiness.industrySupport vector machines (SVMs)Reproducibility of ResultsPattern recognitionAtrial fibrillationHuman atrial fibrillationmedicine.diseaseSupport vector machineSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaAutomatic classificationArtificial intelligenceIntracardiac electrogrambusinessElectrocardiographyAlgorithmsIEEE Transactions on Biomedical Engineering
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PPG/ECG Multisite Combo System Based on SiPM Technology

2019

Two versions of a PPG/ECG combined system have been realized and tested. In a first version a multisite system has been equipped by integrating 3 PPG optodes and 3 ECG leads, whereas in another setup a portable version has been carried out. Both versions have been realized by equipping the optical probes with SiPM detectors. SiPM technology is expected to bring relevant advantages in PPG systems and overcome the limitations of physiological information extracted by state of the art PPG, such as poor sensitivity of detectors used for backscattered light detection and motion artifacts seriously affecting the measurements repeatability and pulse waveform stability. This contribution presents t…

Signal processingComputer scienceSiPM020209 energyPipeline (computing)Detector02 engineering and technologyPPG SiPMs Pattern recognitionSettore ING-INF/01 - ElettronicaSilicon photomultiplierPattern recognitionvisual_artSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaElectronic componentPattern recognition (psychology)0202 electrical engineering electronic engineering information engineeringvisual_art.visual_art_mediumElectronic engineeringWaveformPPGSensitivity (control systems)
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A nonstationary model for the analysis of transient speech signals

1987

In this correspondence, a model is presented for the analysis of transient speech signals, which is based on a sum of the impulsive responses corresponding to a number of poles with time-dependent parameters. The aim of this analysis is to obtain discriminative features of the different transient elements of speech.

Signal processingComputer scienceSignal reconstructionSpeech recognitionSpeech processingsymbols.namesakeFourier transformDiscriminative modelComputer Science::SoundFrequency domainSignal ProcessingsymbolsTransient (oscillation)Decoding methodsIEEE Transactions on Acoustics, Speech, and Signal Processing
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Signal Processing for Image Enhancement and Multimedia Processing

2008

Signal processingMultimediaComputer scienceSpeech recognitionImage enhancementcomputer.software_genrecomputer
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Electrocardiogram Signal Analysing - Delineation and Localization of ECG Component

2016

In this paper, we develop a new approach based on nonlinear filtering scheme (NLFS) on cardiac signal to evaluate a robust single-lead electrocardiogram (ECG) delineation system and waves localization method based on nonlinear filtering approach. This system is built in two phases, in the first phase, we proposed a mathematical model for detecting ECG features like QRS complex peak, P and T-waves onsets and ends from noise free of synthetic ECG signal. Later, we develop a theoretical model to obtain real approach for detecting these features from real noisy ECG signals. Our method has been evaluated on electrocardiogram signals of QT-MIT standard database, the QRS peak achieve sensitivity (…

Signal processingNoise (signal processing)Computer sciencebusiness.industryPhase (waves)Pattern recognitionSignalStandard deviationQRS complexComputer visionSensitivity (control systems)Artificial intelligenceEcg signalbusinessProceedings of the 9th International Joint Conference on Biomedical Engineering Systems and Technologies
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Observer-based finite-time fuzzy H∞ control for discrete-time systems with stochastic jumps and time-delays

2014

This paper is concerned with the problem of observer-based finite-time H ∞ control for a family of discrete-time Markovian jump nonlinear systems with time-delays represented by Takagi-Sugeno (T-S) model. The main contribution of this paper is to design an observer-based finite-time H ∞ controller such that the resulting closed-loop system is stochastic finite-time bounded and satisfies a prescribed H ∞ disturbance attenuation level over the given finite-time interval. Sufficient criteria on stochastic finite-time H ∞ stabilization via observer-based fuzzy state feedback are presented for the solvability of the problem, which can be tackled by a feasibility problem in terms of linear matrix…

Signal processingObserver (quantum physics)Finite-time H∞ controlTakagi-Sugeno (T-S) modelMarkovian jump systemsFuzzy control systemFuzzy logicFinite-time H∞ control; Markovian jump systems; Observer-based control; Takagi-Sugeno (T-S) model; Electrical and Electronic Engineering; Control and Systems Engineering; Software; Signal Processing; 1707Nonlinear systemobserver-based controlTakagi–Sugeno (T–S) modelDiscrete time and continuous timeControl and Systems EngineeringControl theoryBounded functionSignal ProcessingComputer Vision and Pattern RecognitionState observerElectrical and Electronic Engineeringfinite-time H∞ controlfinite-time H infinity controlObserver-based controlSoftware1707Mathematics
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Information – theoretic characterization of concurrent activity of neural spike trains

2021

The analysis of massively parallel spike train recordings facilitates investigation of communications and synchronization in neural networks. In this work we develop and evaluate a measure of concurrent neural activity, which is based on intrinsic firing properties of the recorded neural units. An overall single neuron activity is unfolded in time and decomposed into working and non-firing state, providing a coarse, binary representation of the neurons functional state. We propose a modified measure of mutual information to reflect the degree of simultaneous activation and concurrency in neural firing patterns. The measure is shown to be sensitive to both correlations and anti-correlations,…

Signal processingQuantitative Biology::Neurons and CognitionArtificial neural networkComputer sciencebusiness.industrySpike trainFiring patterns020206 networking & telecommunicationsPattern recognition02 engineering and technologyMeasure (mathematics)Concurrent activityMutual informationNeural activitymedicine.anatomical_structure0202 electrical engineering electronic engineering information engineeringmedicineSpike trains020201 artificial intelligence & image processingSpike (software development)NeuronArtificial intelligencebusinessNeural synchrony2020 28th European Signal Processing Conference (EUSIPCO)
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Nonparametric statistics for DOA estimation in the presence of multipath

2002

This paper is concerned with array signal processing in nonGaussian noise and in the presence of multipath. Robust and fully nonparametric high resolution algorithms for direction of arrival (DOA) estimation are presented. The algorithms are based on multivariate spatial sign and rank concepts. Spatial smoothing of the multivariate rank and sign based covariance matrices is employed as a preprocessing step in order to deal with coherent sources. The performance of the algorithms is studied using simulations. The results show that almost optimal performance is obtained in wide variety of different noise conditions.

Signal processingRank (linear algebra)business.industryNoise (signal processing)Nonparametric statisticsDirection of arrivalPattern recognitionArtificial intelligenceCovariancebusinessSmoothingMultipath propagationMathematicsProceedings of the 2000 IEEE Sensor Array and Multichannel Signal Processing Workshop. SAM 2000 (Cat. No.00EX410)
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