Estimation of time delay by coherence analysis

R. B. Govindan, J. Raethjen, F. Kopper, J. C. Claussen, G. Deuschl*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Using coherence analysis (which is an extensively used method to study the correlations in frequency domain, between two simultaneously measured signals) we estimate the time delay between two signals. This method is suitable for time delay estimation of narrow band coherence signals for which the conventional methods cannot be reliably applied. We show, by analysing coupled Rössler attractors with a known delay, that the method yields satisfactory results. Then, we apply this method to human pathologic tremor. The delay between simultaneously measured traces of electroencephalogram (EEG) and electromyogram (EMG) data of subjects with essential hand tremor is calculated. We find that there is a delay of 11-27 milli-seconds (ms) between the tremor correlated parts (cortex) of the brain (EEG) and the trembling hand (EMG) which is in agreement with the experimentally observed delay value of 15 ms for the cortico-muscular conduction time. By surrogate analysis we calculate error bars of the estimated delay.

Original languageEnglish
Pages (from-to)277-295
Number of pages19
JournalPhysica A: Statistical Mechanics and its Applications
Volume350
Issue number2-4
DOIs
Publication statusPublished - 15 May 2005

Bibliographical note

© 2005, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Keywords

  • Coherence
  • Spectral methods
  • Time delay
  • Time series

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