Использование параметров нестационарности сигналов легочной аускультации для обнаружения и локализации легочной патологии

Abstract

Introduction. The paper proposes the use of monitoring of pH in the esophagus in combination with an auscultation of the lungs to assess the effect of gastrointestinal-esophageal-tracheobronchial reflux. Problem statement. Methodology. A typical auscultatory signal is presented as a quasiperiodic random process and bronchoobstructive changes caused by reflux as a random factor affecting this process. The approach of estimating the step of the influence of this factor is proposed on the basis of comparison of indices of the nonstationarity of the spectrum of the signal itself and its linear transformation. To calculate the spectral-temporal signal parameters, a continuous wavelet transform for the discrete signals was used. The level of significance of the factor influence the informative signal was estimated using T-statistics. Purpose of work. Increasing the effectiveness of information and measurement technologies for non-invasive express control of the state of respiratory organs in the diagnosis of reflux-associated bronchial asthma. Research results. As a result of the work, a method for evaluating the effect of reflux on respiratory organs during postoperative recovery was developed and experimentally confirmed. The method consists in the computation of informative indicators that quantify the level of the nonstationarity of the signal and its linear transformation, the coefficients of the inter-spectral correlation. The results of experimental studies confirmed the effectiveness and statistical significance of the proposed method and informative indicators. Conclusion. The task of increasing the reliability of the classification of postoperative pulmonary complications was solved in the work, and the possibility of localization of lung limb obstruction was proved by means of auscultative signal monitoring The use of the mathematical apparatus presented in the article may prove useful in solving the problem of diagnosis of gastroesophagotracheobronchial reflux and reflux-associated bronchial asthma.