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Updated: May 31, 2026

Automated Analysis of Dynamic Ca2+ Signals in Image Sequences
Published on: June 16, 2014
New method for analysis of nonstationary signals
1Laboratory of Biosignal Analysis Fundamentals, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks, Trojdena 4 st,, Warsaw, 02-109, Poland. step@ibib.waw.pl.
Background:
Analysis of signals by means of symbolic methods consists in calculating a measure of signal complexity, for example informational entropy or Lempel-Ziv algorithmic complexity. For construction of these entropic measures one uses distributions of symbols representing the analyzed signal.
Results:
We introduce a new signal characteristic named sequential spectrum that is suitable for analysis of the wide group of signals, including biosignals.The paper contains a brief review of analyses of artificial signals showing features similar to those of biosignals. An example of using sequential spectrum for analyzing EEG signals registered during different stages of sleep is also presented.
Conclusions:
Sequential spectrum is an effective tool for general description of nonstationary signals and it its advantage over Fourier spectrum. Sequential spectrum enables assessment of pathological changes in EEG-signals recorded in persons with epilepsy.
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