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Titolo:
Conditional entropy approach for the evaluation of the coupling strength
Autore:
Porta, R; Baselli, G; Lombardi, F; Montano, N; Malliani, A; Cerutti, S;
Indirizzi:
Univ Milan, Dipartimento Sci Preclin, Milan, Italy Univ Milan Milan Italy iv Milan, Dipartimento Sci Preclin, Milan, Italy Univ Brescia, Dipartimento Elettron Automaz, Brescia, Italy Univ Brescia Brescia Italy ipartimento Elettron Automaz, Brescia, Italy Osped San Paolo, Milan, Italy Osped San Paolo Milan ItalyOsped San Paolo, Milan, Italy Univ Milan, Osped L Sacco, Ctr Ric Cardiovasc, CNR, I-20122 Milan, Italy Univ Milan Milan Italy I-20122 Ric Cardiovasc, CNR, I-20122 Milan, Italy Politecn Milan, Dipartimento Bioingn, Milan, Italy Politecn Milan Milan Italy cn Milan, Dipartimento Bioingn, Milan, Italy
Titolo Testata:
BIOLOGICAL CYBERNETICS
fascicolo: 2, volume: 81, anno: 1999,
pagine: 119 - 129
SICI:
0340-1200(199908)81:2<119:CEAFTE>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
TIME-SERIES; SYMPATHETIC DISCHARGE; SPECTRAL-ANALYSIS; DECEREBRATE CATS; SYNCHRONIZATION; SYSTEMS; NONLINEARITY; OSCILLATORS; VARIABILITY; COMPLEXITY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Porta, R Univ Milan, Osped L Sacco, Dipartimento Sci Preclin, Via GB Grassi 74, I-20157 Milan, Italy Univ Milan Via GB Grassi 74 Milan Italy I-20157157 Milan, Italy
Citazione:
R. Porta et al., "Conditional entropy approach for the evaluation of the coupling strength", BIOL CYBERN, 81(2), 1999, pp. 119-129

Abstract

A method that enables measurement of the degree of coupling between two signals is presented. The method is based on the definition of an uncoupling function calculating, by means of entropy rates, the minimum amount of independent information (i.e. the information carried by one signal which cannot be derived from the other). An estimator of the uncoupling function able to deal with short segments of data (a few hundred samples) is proposed, thus enabling the method to be used for usual experimental recordings. A synchronisation index is derived from the estimate of the uncoupling function by means of a minimisation procedure. It quantifies the maximum amount of information exchanged between the two signals. Simulations in which non-linear coordination schemes are produced and changes in the coupling strength are artificially induced are used to check the ability of the proposed index to measure the degree of synchronisation between signals. The synchronisation analysis is utilised to measure the coupling strength between the beat-to-beat variability of the sympathetic discharge and ventilation in decerebrate artificially ventilated cats and the degree of synchronisation between the beat-to-beat variability of the heart period and ventricular repolarisation interval in normal subjects and myocardial infarction patients. The sympathetic discharge and ventilation are strongly coupled and the coupling strength is not affected by manoeuvres capable of increasing or depressing sympathetic activity. The synchronisation is lost after spinalisation. The synchronisation analysis confirms that the heart period and ventricular repolarisation interval are well coordinated. In normal subjects, the synchronisation index is not modified by experimental conditions inducing changes inthe sympathovagal balance. On the contrary, it strongly decreases after myocardial infarction, thus detecting and measuring the uncoupling between the heart period and ventricular repolarisation interval.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 14/07/20 alle ore 09:22:39