Аннотация

Кузин А.И. Методы и аппаратура неинвазивных исследований электрической активности желудочно-кишечного тракта. – Рукопись.

Диссертация на соискание ученой степени кандидата технических наук по специальности 05.11.17 – медицинские приборы и системы. – Харьковский национальный университет радиоэлектроники, Харьков, 2002.

Разработан метод оценки интенсивности и направления моторики по биопотенциалам, регистрируемым от конечностей. Достоверность метода подтверждена одновременно проводимой рентгенографией. В ходе разработки метода исследованы: поведение электродов для отведения сверхнизкочастотных биопотенциалов с поверхности тела; возможности резонансных активных фильтров в подстройке к индивидуальным характеристикам электрической активности органов желудочно-кишечного тракта; методы цифрового спектрального анализа сигналов желудка и кишечника в том числе алгоритм минимизации избыточного представления сигнала с использованием нейронной сети; влияние схемотехнических решений усилителей биопотенциалов желудка на шумовые характеристики сигнала при отведении от проекции на брюшную стенку.

На основе проведенных экспериментальных и теоретических исследований обоснованы параметры аппаратуры электроэнтерографии и усовершенствованы характеристики аппаратуры электрогастрографии.

Ключевые слова: электроэнтерография, электрогастрография, моторика.

Abstract

Kuzin A.I. Methods and technique for noninvasive gastrointestinal electrical activity studies. – Manuscript.

Dissertation for a degree of Candidate of Sciences in Technics on the specialty 05.11.17 – Medical devices and systems. – Kharkiv National University of Radioelectronics. Kharkiv. Ukraine. 2002.

A method for estimating intensity and direction of gastrointestinal motor activity is presented. In the approach cutaneous electrodes are placed on the limbs. Reliability of the method has been proved by simultaneously-conducted roentgenography.

While developing the method the following problems have been researched into:

Restrictions and possibilities of gastrointestinal electrical activity (GiEA) recordings from the skin surface. This theoretical study has resulted in proposing limbs recording model which suggests an idea of avoiding the omenta.

Noise and drift parameters of commonly-used electrodes within the range of electroenterogram frequencies. The performances of Ag/AgCl and stainless steel electrodes with different active surface are measured and compared. It has been concluded that silver/silver chloride electrodes meet the requirements of adequate recording as far as electrode exchange current exceeds a hundredfold input bias and/or offset current of the input stage amplifier.

Possibilities of the resonance active filters in electroenterogram signal preprocessing. In order to fit individual electrical parameters of GiEA such features of the proposed filters as are explored: frequency, gain, merit adjustment and phase detection.

Restrictions and possibilities of GiEA analysis methods. Apart from theoretical comparisons, the excessive signal representation algorithm based on a neural network has been explored in practice. The algorithm showed 3.75 times higher spectral resolution and more distinct time-frequency plot than Fourier fast transform.

Stability of electrogastrogram recordings. The compromise between high input impedance and acceptable signal-to-noise rate has been found by improving a multichannel electrogastrograph circuitry.

Informativeness of electroenterogram. In order to estimate the knowledge of the recordings from the limbs, stomach electroenterography and electrogastrography were done simultaneously. The experiments indicated sufficient time correlation between the signals, which implies at least equal usefulness compared to electrogastrography.

The said explorations have also let one rationalize parameters for the equipment to be used in the above-mentioned method.

Keywords: motor activity, electroenterogram, electrogastrogram.