Kulikov V.B. Stochastic and singular analysis of fractal signals for space biomedicine systems. Aerospace and Environmental Medicine 2021 V. 55 № 1/1 special issue. P.69-70.

Авторы: Куликов В.Б.

Stochastic and singular analysis of fractal signals for space biomedicine systems

Kulikov V.B.

Nizhny Novgorod State Technical University named after R.E. Alekseev, Nizhny Novgorod, Russia
E-mail: vb.kulikov@ yandex.ru


Introduction. The report is devoted to the consideration of methods for the analysis of experimental data for medical monitoring systems in the conditions of space flight on orbital stations and in the conditions of cosmonaut training on Earth, the creation of stochastic components of expert systems for the processes of diagnosis and therapy. The methods are relevant for creating mathematical models of the mechanisms of functioning of human organs and systems with fractal stochastic properties, as well as for space gastroenterology and other branches of biomedicine.

Purpose of the study. The aim of the study is to develop new approaches to the study of random processes with fractal and chaotic properties.

Research methods. Identification methods are based on algorithms for solving inverse ill-posed problems, including identification of the distribution laws of random biomedical indicators and verification aspects of test problems. The identification of the desired characteristics of the probability density is performed by solving the Fredholm integral equation of the first kind on a limited sample. The solution of such problems is based on regularization methods.

The proposed scientific approach also allows us to obtain new results and conduct stochastic analysis on a variety of indicators of the human immune system.

The results of the research. The results of a study on stochastic and singular analysis of the experimental implementation of a fractal random process – the EGG signal (electrogastroenterographic signal) in gastroenterology (clinical data) are presented. Identified the distribution of local segments of the process based on the developed algorithms and programs for the diagnosis, implemented a modification of the singular spectral analysis (SSA method) in order to compress the signal and faster Troubleshooting; investigated the trajectory matrix EGG signal. It is shown that the segments of the EGG signal and their first differences (up to the third) have polymodal distribution densities [Kulikov V., Kulikov A., Ignatyev А., 2021)].

Conclusions. The identification time of a single polymodal distribution depends on its complexity and ranges from a few tenths to 10–15 seconds with a sample size of up to 10,000 samples, which allows us to consider the method as a rapid analysis. A similar diagnostic complex can be formed for the respiratory and cardiovascular systems.

The combination of SSA algorithms, wavelet analysis, the perturbation method, and independent components (ICA) will allow identifying dominant and latent factors in the study of the functioning of the gastrointestinal tract and other organs and systems of the astronaut.

The results of the performed studies are relevant for the data processing of the «Splanh» medical space experiment conducted by the SSC RF-IMBP RAS.

The research is carried out with the financial support of the Russian Foundation for Basic Research in the framework of scientific project No. 19-07-00926_a.

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