dr inż. Agnieszka Kaczkowska
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Year 2017

Visualization of shortterm heart period variability with network tools as a method for quantifying autonomic drive
PublicationWe argue that network methods are successful in detecting nonlinear properties in the dynamics of autonomic nocturnal regulation in shortterm variability. Two modes of visualization of networks constructed from RRincrements are proposed. The first is based on the handling of a state space. The state space of RRincrements can be modified by a bin size used to code a signal and by the role of a given vertex as the representation...
Year 2015

Chronographic Imprint of AgeInduced Alterations in Heart Rate Dynamical Organization
PublicationBeattobeat changes in the heart period are transformed into a network of increments between subsequent RRintervals, which enables graphical descriptions of shortterm heart period variability. Three types of such descriptions are considered: (1) network graphs arising from a set of vertices and directed edges, (2) contour plots of adjacency matrices A, representing the networks and transition matrices T, resulting from A, and (3)...

Entropic Measures of Complexity of ShortTerm Dynamics of Nocturnal Heartbeats in an Aging Population
PublicationTwo entropybased approaches are investigated to study patterns describing differences in time intervals between consecutive heartbeats. The first method explores matrices arising from networks of transitions constructed following events represented by a time series. The second method considers distributions of ordinal patterns of length three, whereby patterns with repeated values are counted as different patterns. Both methods provide...

Entropy Measures in the Assessment of Heart Rate Variability in Patients with Cardiodepressive Vasovagal Syncope
PublicationSample entropy (SampEn) was reported to be useful in the assessment of the complexity of heart rate dynamics. Permutation entropy (PermEn) is a new measure based on the concept of order and was previously shown to be accurate for short, nonstationary datasets. The aim of the present study is to assess if SampEn and PermEn obtained from baseline recordings might differentiate patients with various outcomes of the headup tilt test...

Generalised heart rate statistics reveal neurally mediated homeostasis transients
PublicationDistributions of accelerations and decelerations, obtained from increments of heart rate recorded during a headup tilt table (HUTT) test provide shortterm characterization of the complex cardiovascular response to a rapid controlled dysregulation of homeostasis. A generalised statistic is proposed for evaluating the neural reflexes responsible for restoring the homeostatic dynamics. An evaluation of the effects on heart rate...
Year 2014

Network Approach to Increments of RRintervals for Visualization of Dynamics of Cardiac Regulation
PublicationThe transition network for RR increments is pre sented in a directed and weighted graph, with vertices represent ing RR increments and edges corresponding to the order in a sequence of increments. The adjacency matrix and the transition matrix of this network provide a graphical tool which could be useful in the assessment of cardiac regulation. As an example, the method is applied in detecting differences between diurnal activity...

Ordinal Pattern Statistics for RR Intervals during HeadUp Tilt Test in Patients with the History of Vasovagal Syncope
PublicationWe apply ordinal pattern analysis to quantify differences in distribution of patterns of length 3 and 4 in basal state and during headup tilt test (HUTT) in patients with the history of syncope and positive (HUTT(+)) or negative (HUTT()) responses to the test. We identify the patterns related to prevalence of sympathetic or parasympathetic cardiac modulation as well as describe the relations between the response to the test and...

Temporal Changes in Complexity of Cardiovascular Regulation during HeadUp Tilt Test by Entropic Measures of Fluctuations of Heart Period Intervals and Systolic Blood Pressure
PublicationTemporal changes in complexity of cardiovascular regulation during headup tilt test by entropic measures of fluctuations of heart period intervals and systolic blood pressure
Year 2013

Ordinal pattern statistics for the assessment of heart rate variability
PublicationThe recognition of all main features of a healthy heart rhythm (the socalled sinus rhythm) is still one of the biggest challenges in contemporary cardiology. Recently the interesting physiological phenomenon of heart rate asymmetry has been observed. This phenomenon is related to unbalanced contributions of heart rate decelerations and accelerations to heart rate variability. In this paper we apply methods based on the concept...

Reducing the number of periodic points in the smooth homotopy class of a selfmap of a simplyconnected manifold with periodic sequence of Lefschetz numbers
PublicationLet f be a smooth selfmap of an mdimensional (m >3) closed connected and simplyconnected manifold such that the sequence of the Lefschetz num bers of its iterations is periodic. For a fixed natural r we wish to minimize, in the smooth homotopy class, the number of periodic points with periods less than or equal to r. The resulting number is given by a topological invariant J[f] which is defned in combinatorial terms and is...

The Efficiency of Polish Stock Market: Ordinal Patterns Approach
PublicationZunino et al. analyzed the problem of discrimination of developed and emergent markets by the use of ordinal patterns methods: number of forbidden patterns and ordinal pattern probability distribution as a basis for entropy and statistical measure of complexity. In this paper we apply the same methodology for the analysis of Polish stock market (index WIG). The results indicate that Polish market belongs neither to developed, nor...
Year 2012

Entropy measures of heart rate variability for short ECG datasets in patients with congestive heart failure
PublicationWe investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (FuzzyEn) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length...

Entropy Measures of heart rate variability for short ECG datasets in patients with congestive heart failure
PublicationWe investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (Fuzzy En) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length...

Lefschetz periodic point free selfmaps of compact manifolds
PublicationLet f be a selfmap of a compact connected manifold M. We characterize Lefschetz periodic point free continuous selfmaps of M for several classes of manifolds and generalize the results of Guirao and Llibre [J.L.G. Guirao, J. Llibre, On the Lefschetz periodic point free continuous selfmaps on connected compact manifolds,

Lefschetz periodic point free selfmaps of compact manifolds
PublicationLet f be a selfmap of a compact connected manifold M. We characterize Lefschetz periodic point free continuous selfmaps of M for several classes of manifolds and generalize the results of Guirao and Llibre [J.L.G. Guirao, J. Llibre, On the Lefschetz periodic point free continuous selfmaps on connected compact manifolds, Topology Appl. 158 (16) (2011) 21652169].

Minimization of the number of periodic points for smooth selfmaps of simplyconnected manifolds with periodic sequence of Lefschetz numbers
PublicationLet f be a smooth selfmap of mdimensional, m ≥ 4, smooth closed connected and simplyconnected manifold, r a fixed natural number. For the class of maps with periodic sequence of Lefschetz numbers of iterations the authors introduced in [Graff G., Kaczkowska A., Reducing the number of periodic points in smooth homotopy class of selfmaps of simplyconnected manifolds with periodic sequence of Lefschetz numbers, Ann. Polon. Math....
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