title: Interpretation of heart rate variability via detrended fluctuation analysis and alphabeta filter.
abstract: Detrended fluctuation analysis (DFA), suitable for the analysis of nonstationary time series, has confirmed the existence of persistent long-range correlations in healthy heart rate variability data. In this paper, we present the incorporation of the alphabeta filter to DFA to determine patterns in the power-law behavior that can be found in these correlations. Well-known simulated scenarios and real data involving normal and pathological circumstances were used to evaluate this process. The results presented here suggest the existence of evolving patterns, not always following a uniform power-law behavior, that cannot be described by scaling exponents estimated using a linear procedure over two predefined ranges. Instead, the power law is observed to have a continuous variation with segment length. We also show that the study of these patterns, avoiding initial assumptions about the nature of the data, may confer advantages to DFA by revealing more clearly abnormal physiological conditions detected in congestive heart failure patients related to the existence of dominant characteristic scales.
authors.affiliation: School of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom. jcea@xanum.uam.mx
authors.forename: J C
authors.initials: JC
authors.lastname: Echeverría
authors.forename: M S
authors.initials: MS
authors.lastname: Woolfson
authors.forename: J A
authors.initials: JA
authors.lastname: Crowe
authors.forename: B R
authors.initials: BR
authors.lastname: Hayes-Gill
authors.forename: G D H
authors.initials: GD
authors.lastname: Croaker
authors.forename: H
authors.initials: H
authors.lastname: Vyas
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D016011:Normal Distribution; D010363:Pattern Recognition, Automated; D012016:Reference Values; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012890:Sleep; D013223:Statistics as Topic; D013269:Stochastic Processes; D014851:Wakefulness