This paper presents an application of Approximate Entropy (ApEn) and Sample Entropy (SampEn) in the analysis of heart rhythm, blood pressure and stroke volume for the diagnosis of vasovagal syndrome. The analyzed biosignals were recorded during positive passive tilt tests—HUTT(+). Signal changes and their entropy were compared in three main phases of the test: supine position, tilt, and pre-syn...

The detection of motion from image sequences is usually performed using a time differential method or calculating the difference from a background reference image. These algorithms often perform poorly in the presence of temporal clutter. This paper describes a technique that measures the irregularity of an intensity sequence to detect motion. We demonstrate that static background, interesting ...

Information entropy as a universal and fascinating statistical concept is helpful for numerous problems in the computational sciences. Approximate entropy (ApEn), introduced by Pincus (1991), can classify complex data in diverse settings. The capability to measure complexity from a relatively small amount of data holds promise for applications of ApEn in a variety of contexts. In this work we a...

In the real world, we are confronted not only with complex and high-dimensional data sets, but usually with noisy, incomplete and uncertain data, where the application of traditional methods of knowledge discovery and data mining always entail the danger of modeling artifacts. Originally, information entropy was introduced by Shannon (1949), as a measure of uncertainty in the data. But up to th...

This work describes the complexity found in the normal and the deaf crying acoustic waves. Using approximate entropy, in a single figure, the complexity of the auto-covariance of the signal is computed. Thus, using this complexity value, we are able to discriminate the normal and the deaf infants crying domains with

Larynx cancer patients receive radiotherapy as a non-invasive alternative to surgery and cure rates are high. Inevitably this impacts vocal fold functional-ity. Hence, voice recovery as a prerequisite for resuming normal life is of special interest. Voicing recovery following radiotherapy is studied in this paper. Complexity analysis, using approximate entropy to concisely quantify the collecti...

We use entropy to extend the rough set based notion of a reduct. We show that the order based genetic algorithms, applied to the search of classical decision reducts, can be used in exactly the same way in case of extracting optimal approximate entropy reducts from data.

Richman, Joshua S., and J. Randall Moorman. Physiological time-series analysis using approximate and sample entropy. Am J Physiol Heart Circ Physiol 278: H2039–H2049, 2000.—Entropy, as it relates to dynamical systems, is the rate of information production. Methods for estimation of the entropy of a system represented by a time series are not, however, well suited to analysis of the short and no...

This paper addresses the problem of measuring complexity from embedded attractors as a way to characterize changes in the dynamical behavior of different types of systems with a quasi-periodic behavior by observing their outputs. With the aim of measuring the stability of the trajectories of the attractor along time, this paper proposes three new estimations of entropy that are derived from a M...