Comparison of digital filter and wavelet transform for extracting electroencephalogram rhythm.
- Author:
Taorong XIE
1
;
Jian PEI
;
Caili JIA
;
Shude CHEN
;
Dengjiang QIAO
Author Information
1. State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China.
- Publication Type:Journal Article
- MeSH:
Algorithms;
Artifacts;
Brain;
physiology;
Electroencephalography;
methods;
Humans;
Signal Processing, Computer-Assisted
- From:
Journal of Biomedical Engineering
2009;26(4):743-747
- CountryChina
- Language:Chinese
-
Abstract:
It is very important to extract electroencephalogram (EEG) rhythm in clinical diagnoses. Digital filter and wavelet transform are used to extract the rhythm from a piece of EEG at the sampling rate of 2 kHz. The Daubechies order 4 wavelet (db4) was used to decompose the EEG at 8 levels. According to the filter characteristic of wavelet decomposition, the reconstructions of aS, d8, d7, d6 and d5 component are nearly corresponding to the rhythms of delta, theta, alpha, gamma separately. The 6 order ellipse infinite impulse response (IIR) filter is also used to decompose the EEG. As the quality factor of wavelet decomposition filter is constant, the wavelet transform obtains better extracted rhythm than the digital filter. Furthermore, the wavelet transform method can be used to extract the low frequency rhythm from wide frequency band.
