Use Of Autocorrelation To Improve The Three Dimensional Plot Of Transcutaneous Human electrogastrograms

Transcutaneous human electrogastrograms (EGG) have been recorded for many years without significant improvement in their interpretation. The application of amplitude or power spectrum analysis is a powerful method to analyse EGG signals which have a relatively narrow frequency band and infralow fundamental frequencies (0.03-0.1 Hz) . Three dimensional plots are often used to represent the dynamics of the amplitude or power changes in the EGG signals vs. frequency and time. Because of the movement and respiratory artifacts three dimensional plots are not always clear enough to allow further interpretation of the results. In this paper we address that problem suggesting three dimensional plot of the autocorrelated EGG signals. The proposed method minimizes the influence of the artifacts and provides both repeatable results and good possibilities for interpretation.