O.I. Antipov, M.Yu. Nagornaya
At present considerable interest of physiologists and clinicians to study the motor-evacuation activity of the stomach and intestines and the development of methods that allow both qualitatively and quantitatively assess the intensity and nature of motor activity of various gastrointestinal tract.
Already in the middle of XX century for the study of smooth muscle cells motor function used methods of measuring its electrical activity. For this use both inside and extracellular signal derivation methods. The electrogastrography is a method of studying, allowing evaluation of the bioelectric activity of the stomach, duodenum and other parts of the digestive tract. The electrogastrography is based on registration of electric potential changes of the bodies of the digestive tract.
However despite the numerous works carried out in this area, the uniform method of recording and analysis of bioelectrical activity of the stomach and intestines is absent. The great interest for deciphering electrogastrograms (EGG) is fractal analysis. At the moment proved fractal properties are vascular system of the animal organism, the dynamics of functions of the brain, heart, and electrically active cells. The explorers produce fractal analysis electrogastrogram signal shot by peripheral electrogastrography.
In the fractals and deterministic chaos theory one of the most popular method is Hurst’ normalized amplitude method. The main parameter which can be found by this method is a Hurst index. The Hurst index using advantage is based on the fact that its value can be define of the degree of the system randomization. The electrogastrogram signal Hurst index was calculated in this article. The Hurst index was equal to 0.71 that demonstrating the fractal nature of EGG. Thus it can be argued that the process that gave rise to this signal has a long-time memory, i.e. the investigated signal is persistent. The investigated electrogastrogram signal power spectrum was calculated in he second part of the article. The power spectrum was found as an autocorrelation function’ Fourier transform. The electrogastrogram power spectrum analysis allowed to classify of EGG as a fractal fractional noise. This fact also confirms the hypothesis of the studied signal fractal nature. The results achieved in the work prove the possibility of the fractal measures using for the signals of this class in a diagnostic problems. This fact may find application in medical practice.