RESUMO
This paper introduced the definition, structure of basis wavelet functions and wavelet lifting. Wavelet transform and wavelet lifting were applied in signal processing of EGG in our study. The characteristics of signal energy, information entropy and joint entropy were analyzed to introduce general selective method of wavelet basis functions after the signals have been filtered. In order to verify the rationality of evaluation criteria, signals of electrogastrogram (EGG) were processed and filtered with different wavelet basis functions in the experiments. Signals of EGG were filtered by wavelet transform and wavelet lifting, slow wave and spike wave of EGG were filtered. And the rationality of wavelet transform, wavelet lifting and effectiveness of EGG filter algorithm were proved by the experimental data. It provided an effective solution for the diagnosis and measurement of gastric diseases.
Assuntos
Humanos , Eletrodiagnóstico , Métodos , Gastroenteropatias , Diagnóstico , Motilidade Gastrointestinal , Processamento de Sinais Assistido por Computador , Estômago , Fisiologia , Análise de OndaletasRESUMO
This paper presents a removal method of electrogastrogram (EGG) baseline wander based on wavelet transformation. The basic idea of this method is using the low-frequency signal which is obtained through multi-scale decomposition of EGG signals to approximate the baseline wander of EGG, so the component of baseline wander is filtered out from the sampling EGG signals. The method was applied successfully to process the experimental data of dog EGG in our laboratory. The experimental data and analysis of results showed that this method could filter out the baseline wander of EGG, and this method would not affect the gastric spike and slow wave bandwidth signals, which could be shown from the characteristics of bandwidth filter of wavelet transformation.