A Multiscale Energy-Based Time-Domain Approach for Interference Detection in Non-stationary Signals

Author(s):  
Vittoria Bruni ◽  
Lorenzo Della Cioppa ◽  
Domenico Vitulano
2014 ◽  
Vol 14 (5) ◽  
pp. 270-278 ◽  
Author(s):  
P. Sovilj ◽  
M. Milovanović ◽  
D. Pejić ◽  
M. Urekar ◽  
Z. Mitrović

Abstract Measurement methods, based on the approach named Digital Stochastic Measurement, have been introduced, and several prototype and small-series commercial instruments have been developed based on these methods. These methods have been mostly investigated for various types of stationary signals, but also for non-stationary signals. This paper presents, analyzes and discusses digital stochastic measurement of electroencephalography (EEG) signal in the time domain, emphasizing the problem of influence of the Wilbraham-Gibbs phenomenon. The increase of measurement error, related to the Wilbraham-Gibbs phenomenon, is found. If the EEG signal is measured and measurement interval is 20 ms wide, the average maximal error relative to the range of input signal is 16.84 %. If the measurement interval is extended to 2s, the average maximal error relative to the range of input signal is significantly lowered - down to 1.37 %. Absolute errors are compared with the error limit recommended by Organisation Internationale de Métrologie Légale (OIML) and with the quantization steps of the advanced EEG instruments with 24-bit A/D conversion


2010 ◽  
Vol 5 (3) ◽  
pp. 205-213 ◽  
Author(s):  
M. Muthuraman ◽  
A. Galka ◽  
G. Deuschl ◽  
U. Heute ◽  
J. Raethjen

Author(s):  
M. MacCallum ◽  
A. E. A. Almaini

Polysomnographic (sleep) signals are recorded from patients exhibiting symptoms of a suspected sleep disorder such as Obstructive Sleep Apnoea (OSA). These non-stationary signals are characterised by having both quantitative information in the frequency domain and rich, dynamic data in the time domain. The collected data is subsequently analysed by skilled visual evaluation to determine whether arousals are present, an approach which is both time-consuming and subjective. This paper presents a wavelet-based methodology which seeks to alleviate some of the problems of the above method by providing: (a) an automated mechanism by which the appropriate stage of sleep for disorder observation may be extracted from the composite electroencephalograph (EEG) data set and (b) an ensuing technique to assist in the diagnosis of full arousal by correlation of wavelet-extracted information from a number of specific patient data sources (e.g. pulse oximetry, electromyogram [EMG] etc.).


2004 ◽  
Vol 04 (02) ◽  
pp. L267-L272 ◽  
Author(s):  
K. DAROWICKI ◽  
A. ZIELIŃSKI

Approaches to the electrochemical noise (EN) analysis are generally based on the assumption of its stationarity. In spite of usability of such methodology, occurrences of non-stationary signals are rather frequent in the practice. The methods of overcoming this drawback are presented in the paper. Applications of short-time Fourier transformation are discussed. It utilizes the concept of time-localized analyzing functions generated by appropriately chosen sliding time-domain window. Such technique, applied in discrete time measurement regime yields time-dependent frequency EN decomposition. Additionally, the authors introduce the concept of time dependent spectral noise response and spectral noise resistance.


Author(s):  
Michael Feldman

This paper describes a new technique, called the Hilbert Vibration Decomposition method, dedicated to decomposition of non-stationary wideband dynamic signals. Using the Hilbert transform in the time domain, we extract a number of elementary oscillating components of the initial signal, who’s both the instantaneous frequency and envelope can vary in time. Modeling examples of decomposition of non-stationary signals are included.


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