Recognition of true and false states of the brain by means of the electroencephalogram wavelet analysis

It is a well-known fact that mental activity of the brain can be presented by two different states, i.e., the true state and the false state. A promising method of the electroencephalogram (EEG) wavelet transform has been developed over recent years. Using this method, we evaluated the principle possibility for direct objective registration of mental activity in the human brain. Previously we developed and described (published) a new experimental model and software for recognizing the true and false mental responses of a person with the EEG wavelet transform. The developed experimental model and software-and-data support allowed us to compare (by EEG parameters) two mental states of brain activity, one of which is the false state, while another is the true state. The goal of this study is to develop an absolutely new information technology for recognizing the true and false states in mental activity of the brain by means of the EEG wavelet transform. Our study showed that the true and false states of the brain can be distinguished using the method of continuous wavelet transform and calculation of the EEG wavelet energy. It was revealed that the main differences between truthful and false mental responses are observed in the delta and alpha ranges of the EEG. In the EEG delta rhythm, the wavelet energy is much higher under conditions of the false response as compared to that in the true response. In the EEG alpha rhythm, the wavelet energy is significantly higher with the true answer than in the false one. These data open a new principal possibility of revealing the true and false mental state of the brain by means of continuous wavelet transform and calculation of the EEG wavelet energy.

Computer system for metrological testing of location sensors used to monitor the patient's condition in magnetotherapy

Non-contact monitoring of vital signs of a person is a reliable and safe way of promptly obtaining objective diagnostic information about the current physiological state of a patient during surgical operations, physiotherapeutic procedures or during sleep. The absence of direct contact of the sensors with the patient's body makes it possible to exclude the influence of a number of interfering factors, such as a violation or weakening of contact, which can lead to a deterioration in the quality of signals from the output of the sensors, a long-term location of the sensors on the body can have a psychological effect on the patient, changing his condition and thereby distorting the treatment method, etc. In order for the results of monitoring and diagnostics to be reliable and guaranteed accurate, it is necessary to carry out periodic metrological certification of location sensors, especially since many of them are of foreign production and their characteristics are either not standardized or do not meet the requirements of their operating conditions. Therefore, the tasks of developing methods and means for carrying out metrological tests of non-contact sensors for medical purposes are becoming urgent. Purpose – to show the possibility of implementing automated metrological tests of location sensors for medical use based on a personal computer and publicly available standard hardware and software. A method has been developed and implemented for conducting metrological tests of location sensors based on a personal computer, a digital dynamic measure of linear displacement, virtual measuring instruments, laser and ultrasonic sensors, as well as determining conversion errors in the LabVIEW environment. As an exemplary measuring instrument, it is proposed to use a webcam with a virtual device for recording the law of displacement in the LabVIEW Vison Development application. Full-scale experiments have been carried out, in which, using a digital measure of linear displacement, it is possible to reproduce with high accuracy almost any law of displacement and to regulate its informative parameters. Real movement signals were received with the help of virtual devices, recorded by two location sensors and a web camera. The errors of the means of registration are determined in comparison with the given digital method and analytically the law of movement. Introduction of the developed method and hardware and software for metrological certification of sensors of diagnostic channels of the systems of complex magnetotherapy «Multimag» and «Relaxmag». Carrying out automated metrological tests of sensors will ensure prompt, reliable and objective control of their actual characteristics, which means it will increase the effectiveness of treatment due to the prompt and continuous monitoring of the patient's functional state and an objective assessment of a number of important indicators.

Application of various optimization methods in calculating the error of a neural network for diagnosing parasitological diseases of the gastrointestinal tract

Formulation of the problem. This work is devoted to the use of artificial neural networks for diagnosing the functional state of the gastrointestinal tract caused by the influence of parasites in the body. For the experiment, 24 symptoms were selected, the number of which can be increased, and 9 most common diseases. The coincidence of neural network diagnostics with classical medical diagnostics for a specific disease is shown. The purpose of the work is to compare the neural networks in terms of their performance after describing the methods of preprocessing, isolating symptoms and classifying parasitic diseases of the gastrointestinal tract. Computer implementation of the experiment was carried out in the NeuroPro 0.25 software environment and optimization methods were chosen for training the network: "gradient descent" modified by Par Tan, "conjugate gradients", BFGS. Results. The results of forecasting using a multilayer perceptron using the above optimization methods are presented. To compare optimization methods, we used the values of the minimum and maximum network errors. Comparison of optimization methods using network errors makes it possible to draw the correct conclusion that for the task at hand, the best results were obtained when using the "conjugate gradients" optimization method. Practical significance. The proposed approach facilitates the work of the experimenter-doctor in choosing the optimization method when working with neural networks for the problem of diagnosing parasitic diseases of the gastrointestinal tract from the point of view of assessing the network error.

Support for management medical decisions and the nature of uncertainty in them

The process of making a medical decision is characterized by a lack of knowledge and inconsistency of the available information, the lack of the possibility of attracting competent medical experts, limited time resources, incomplete or inaccurate information about the patient's condition. These aspects may be the causes of medical errors, which lead to further aggravation of the problem situation. Purpose – it is necessary to define and justify managerial medical decisions and types of medical information in conditions of uncertainty, when each variant of the sets of outcomes of the situation (recommendations) has its own unique set of values. The fundamental difference between this process for medical use is the concept of the "best medical solution", in which the key role is given to the patient's state of health in obtaining and evaluating alternatives, as well as the need to take into account the time, adverse reactions of the body and the costs of implementing this solution. In the medical field, support for medical decision-making can be classified as organizational-managerial and therapeutic-diagnostic, but both are determined by the position of the person making the medical decision and are aimed at effective management of the medical institution as a whole. The article describes the causes and factors of the nature of uncertainty in the tasks of supporting medical decision-making in medical-diagnostic and organizational-managerial areas. The analysis of the features of supporting medical decision-making in conditions of uncertainty is carried out. Approaches and directions in this area, as well as the concept of “solution”, are considered. The essence of the management medical decision is reflected. The classification of management medical decisions is given, the requirements that are imposed on them are highlighted. The features of the development of management medical solutions in the conditions of incompleteness and uncertainty, the problems that arise when they are implemented in information systems are presented. The general scheme of the process of creating a management medical solution is shown. The features of making group and individual decisions are reflected. The algorithm of actions of the person making the medical decision in the conditions of uncertainty, incompleteness and risk in medical subject areas is presented.

Development of an experimental setup for intraoperative angiography system

The treatment of locally advanced tumors of the head and neck presents serious difficulties due to the difficulty of localizing growths, namely the proximity to vital organs and systems of the body (brain, large blood vessels) and the small size of the areas of intervention limits the choice of treatment methods. So, the development of helper methods and hardware of intraoperative visualization of blood vessels is relevant. So, the development of auxiliary methods and hardware means of intraoperative blood vessel imaging for objective assessment of adequacy of blood supply and differentiated recognition of anatomical structures is especially relevant in biomedical optics. The aim of the work is to create an experimental setup for the development, testing and modification of the algorithms for improving the quality of the image of blood vessels against the background of surrounding tissues by optical method. The article is devoted to technological and program features of developing and creating an experimental setup for intraoperative imaging. Clinical problem of the necessity of vessel imaging has been established. Current state of intraoperative vessel imaging has been analyzed. Structure of the setup has been determined. The requirements for parts of the setup have been formulated. Usage of the chlorophyll as a new liquid for blood substitution has been experimentally justified. A MATLAB-based model for quality evaluation of functions of the setup has been developed. The experimental results obtained in the article are of great practical importance for the development of a biotechnological system for intraoperative vessel imaging.

Register of the human brain acoustic area spectrum

Last years, there were developed methods based on the human brain and body acoustic signals application. We consider human brain micro vibrations as an ancient, highly reliable, relatively rapid channel of the central nervous system with all the organism cells and structures. There is offered a method of the human brain acoustic area spectrum analysis and registration. Experimental sample “Register of the human brain micro vibrations spectrum is developed. The model of the human brain acoustic area generation is offered – neurovascular reflex and related with human brain blood vessels smooth muscularity nerve cells metabolism. In comparison with classical EEG, it is demonstrated that acoustic encephalogram also reflects human brain neuroreflex activity. Piezoelectric sensors, which feature in silicone membrane existence, are investigated. Such type of construction allowed to register human brain mechanical vibrations in the gamut from 0.1 up to 27 Hz. Spectral analysis is specific in that signal integration time is 160 seconds. Meanwhile, 12600 spectral harmonics of the human brain reticular activating system were reliably extracted. For convenience, all the acoustic area spectrum of the human brain was shrunk into segmental frame of reference which is frequency structured matrix of functional conditions multiplicity “multiple arousal” of 24х625 frequency cells size. All the developed technologies and device might be used for the organism adaptation estimations, psycho-emotional conditions estimations and functional-topical diagnosis of the internal parts of the human body.

Influence of digital filtering parameters on the pulse waveform in reflectance photoplethysmography

Photoplethysmography (PPG) is an optical method for recording pulse wave (PW) propagating in the tissue microvasculature. As a rule, filters with infinite impulse response (Butterworth, Bessel, etc.) often used in PPG signal processing introduce distortions in the PW signal. At the same time, the filtering parameters for a more accurate reproduction of PW have not yet been substantiated. The aim of this work is to study the influence of digital filtering parameters, such as bandwidth and filter order, on the pulse waveform. In the study, a digital bandpass Butterworth filter was used. The lower cutoff frequency of the filter varied from 0.1 to 1 Hz, the upper cutoff frequency varied from 2 to 10 Hz and the filter order – from 2nd to 6th. It was found that an increase in the lower cutoff frequency of the bandpass filtering leads to a decrease in the amplitude of the reflected diastolic wave and distortion of the front of the direct systolic wave. A decrease in the upper cutoff frequency leads to damping of the dicrotic notch and a phase shift of the PW. Increasing the filter order decreases the reflected wave amplitude. The minimal distortions of the PPG signal were observed at the lower cutoff frequency of 0.1 Hz, the upper one at 10 Hz and the filter order equal to 2. Thus, these parameters of a bandpass filtering can be recommended for processing PPG signals for a more accurate morphological analysis of PW. The obtained results make it possible to create devices for PW analysis with substantiated medical and technical requirements for filtration parameters.

Modern vision of relationship between theta rhythm and the processes of attention

At present time conceptions of complex neurophysiological mechanisms underlying processes of attention are actively developing. In last few years, several researches revealed rhythmic character of processes of attention. Especially theta-rhythm is considered to be significant in organization of rhythmic interactions between brain zones, which take part in providing attention systems work. The aim of the work – to analyze and summarize modern date about role of theta-rhythm in providing basic processes of attention. The report presents modern data about role of theta-rhythm in processes of attention. Specific features of attention systems are discussed. Thrifold model of attention, developed by Steven E. Petersen and Michael I. Posner is reviewed in detail. Moreover, evidences of rhythmic character of processes of attention are summarized and leading part of theta-activity in providing these processes is demonstrated. We also discuss the investigations by Randolph F. Helfrich and Ian C. Fiebelkorn et al. which stated that the quantization of processes of attention with theta-frequency as a general principle of brain structures activity. Dependence of frequency characteristics of cortex zones of human brain from number of objects of attention is discussed. There is also an analysis of theta-band’s ability to modulate biopotentials of higher frequency. Special attention is paid to the researches focused on theta-gamma coupling. The influence of theta-rhythm phase on gamma-rhythm amplitude in phase-amplitude coupling of theta- and gamma-band is analyzed. Theta-rhythm is considered to be one of the rhythmic components that regulate complex mental functions such as attention, memory and consciousness. Obviously, there is a lack of an exact understanding of the role for every band in mental functions regulation; therefore, more investigations in this field are required. However, several data about the role of theta-band in mental functions was collected. A complex of systems with different physiological and neurochemical basis provides attention. It was demonstrated that attention - is a rhythmical process in which theta-band is a crucial part. Theta-rhythm provides synchronization and joint activity of distant brain structures. Moreover, theta-rhythm modulates high-frequent bands. Theta- gamma-band coupling is supposed to be important for attention. Such cooperation is considered to be an evidence of cortical and subcortical zones and provides coordination of analyzing systems of different level. It is suggested that different phases of theta-band may provide retention/switching of attention or determine information flow. As a summary of review of literary sources, there is a conclusion about high significance of this frequency range in different attention systems functioning.

Mode of use by mobile phone and change of time of simple audio-motor reaction for users of mobile communication. Age related features of ipsilateral and contralateral effects

By analysing the time of a simple auditory-motor reaction with mono-presentation of an audio signal, the effect of the electromagnetic radiation of a mobile phone on the human auditory system is evaluated. Regularities in the frequency of occurrence of ipsi and contralateral effects in mobile users of different age groups are obtained. This study has no analogues in either Russian or foreign publications and is currently exclusive. The purpose was to study age-related features of the severity of ipsi and contralateral effects, depending on the mode of use of the mobile phone. To record the ipsi- and contralateral effects, we used the differences in the average values of a simple auditory-motor reaction between the left and right ears with mono-presentation of the sound signal of 573 respondents of different age groups. The obtained values were compared with the control group data for each age group (491 respondents). If the difference was greater than in the control group, the ipsilateral or contralateral effect was recorded. The severity of the effect was evaluated taking into account the lateral preferences of each participant in the experiments (to which ear the mobile phone is most often held) and the mode of use of the mobile phone. Statistical processing of the results was carried out using the non-parametric Mann-Whitney test and the method of descriptive statistics: prevalence indicator (Pr) (relative frequency of manifestation of a particular attribute in the sample). The comparison of the severity of ipsi and contralateral effects for different age groups allowed us to establish the following patterns. It was found that, in general, the manifestation of the contralateral effect decreases with age, and the ipsilateral effect increases. However, this change is not linear. It is shown that the features of the manifestation of the contralateral and ipsilateral effect for each age group depend both on the time of daily use of a mobile phone and on the total duration of use of a mobile phone. We believe that when studying multidimensional input data, an individual approach is necessary. The presented results confirm the negative effect of the radiation of mobile phones on the auditory system, primarily of our younger generation. Given the special vulnerability of children to physical environmental factors and the depth of penetration of EMR MT into the brain of a child, we believe that from a radiobiological point of view, there is already a need to develop a special SanPiN (sanitary rules and norms) for all available modern low-intensity sources of electromagnetic radiation, including Wi-Fi.