000075732 001__ 75732
000075732 005__ 20191127155501.0
000075732 0247_ $$2doi$$a10.1155/2018/4953273
000075732 0248_ $$2sideral$$a108391
000075732 037__ $$aART-2018-108391
000075732 041__ $$aeng
000075732 100__ $$0(orcid)0000-0003-4068-127X$$aBolea, Juan$$uUniversidad de Zaragoza
000075732 245__ $$aOn the standardization of approximate entropy: multidimensional approximate entropy index evaluated on short-term HRV time series
000075732 260__ $$c2018
000075732 5060_ $$aAccess copy available to the general public$$fUnrestricted
000075732 5203_ $$aBackground. Nonlinear heart rate variability (HRV) indices have extended the description of autonomic nervous system (ANS) regulation of the heart. One of those indices is approximate entropy, ApEn, which has become a commonly used measure of the irregularity of a time series. To calculate ApEn, a priori definition of parameters like the threshold on similarity and the embedding dimension is required, which has been shown to be critical for interpretation of the results. Thus, searching for a parameter-free ApEn-based index could be advantageous for standardizing the use and interpretation of this widely applied entropy measurement. Methods. A novel entropy index called multidimensional approximate entropy, , is proposed based on summing the contribution of maximum approximate entropies over a wide range of embedding dimensions while selecting the similarity threshold leading to maximum ApEn value in each dimension. Synthetic RR interval time series with varying levels of stochasticity, generated by both MIX(P) processes and white/pink noise, were used to validate the properties of the proposed index. Aging and congestive heart failure (CHF) were characterized from RR interval time series of available databases. Results. In synthetic time series, values were proportional to the level of randomness; i.e., increased for higher values of P in generated MIX(P) processes and was larger for white than for pink noise. This result was a consequence of all maximum approximate entropy values being increased for higher levels of randomness in all considered embedding dimensions. This is in contrast to the results obtained for approximate entropies computed with a fixed similarity threshold, which presented inconsistent results for different embedding dimensions. Evaluation of the proposed index on available databases revealed that aging was associated with a notable reduction in values. On the other hand, evaluated during the night period was considerably larger in CHF patients than in healthy subjects. Conclusion. A novel parameter-free multidimensional approximate entropy index, , is proposed and tested over synthetic data to confirm its capacity to represent a range of randomness levels in HRV time series. values are reduced in elderly patients, which may correspond to the reported loss of ANS adaptability in this population segment. Increased values measured in CHF patients versus healthy subjects during the night period point to greater irregularity of heart rate dynamics caused by the disease.
000075732 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/TIN2014-5356-R$$9info:eu-repo/grantAgreement/ES/MINECO/DPI2016-75458-R$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 638284-MODELAGE$$9info:eu-repo/grantAgreement/EC/H2020/638284/EU/Is your heart aging well? A systems biology approach to characterize cardiac aging from the cell to the body surface/MODELAGE$$9info:eu-repo/grantAgreement/ES/DGA/T96
000075732 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000075732 590__ $$a2.591$$b2018
000075732 591__ $$aMATHEMATICS, INTERDISCIPLINARY APPLICATIONS$$b21 / 105 = 0.2$$c2018$$dQ1$$eT1
000075732 591__ $$aMULTIDISCIPLINARY SCIENCES$$b24 / 69 = 0.348$$c2018$$dQ2$$eT2
000075732 592__ $$a0.535$$b2018
000075732 593__ $$aMultidisciplinary$$c2018$$dQ1
000075732 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000075732 700__ $$0(orcid)0000-0003-1272-0550$$aBailón, Raquel$$uUniversidad de Zaragoza
000075732 700__ $$0(orcid)0000-0002-1960-407X$$aPueyo, Esther$$uUniversidad de Zaragoza
000075732 7102_ $$15008$$2800$$aUniversidad de Zaragoza$$bDpto. Ingeniería Electrón.Com.$$cÁrea Teoría Señal y Comunicac.
000075732 773__ $$g2018 (2018), 4953273[15 pp.]$$pComplexity$$tComplexity$$x1076-2787
000075732 8564_ $$s3129900$$uhttps://zaguan.unizar.es/record/75732/files/texto_completo.pdf$$yVersión publicada
000075732 8564_ $$s25326$$uhttps://zaguan.unizar.es/record/75732/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
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000075732 951__ $$a2019-11-27-15:50:36
000075732 980__ $$aARTICLE