RU93658U1 - SYSTEM FOR MEASURING ENERGY TENSION IN THE BRAIN SUBSYSTEMS - Google Patents

Abstract

A system for measuring energy tension in the subsystems of the brain, containing an electrical resistance sensor, a photoplethysmogram sensor, a measuring unit, a signal processing unit, while the output of the electrical skin resistance sensor is connected through the first channel of the measuring unit to the first channel of the signal processing unit, which includes a filter and a determination unit connected in series parameters of the electrical resistance signal, connected to the processing unit with the function of demonstrating the parameters of the electrical resistance on the screen, the output of the photoplethysmogram sensor is connected through the second channel of the measuring unit to the second channel of the signal processing unit, which includes a filter connected in series and an RR-interval selection unit connected to the processor a block with the function of demonstrating the parameters of RR intervals on the screen, a block for selecting a combination of stimuli affecting a person, and an executive block for demonstrating a combination of stimuli, characterized in that electroencephalogram sensors are additionally introduced, connected by their outputs through the third channel of the measuring block to the third channel of the block signal processing, including a filter connected in series and a block for determining the parameters of these signals, connected to a processing unit designed to demonstrate the parameters of the electroencephalogram on the screen, while the block for selecting a combination of stimuli is configured to generate series of 80 sound stimuli of different frequencies or series of 40 sound stimuli stimuli of the same frequency, executive bl

Description

The invention relates to psychology, in particular to the field of psychophysiology and experimental psychology, and can be used to study and evaluate the characteristics of the course of cognitive processes and the emotional-volitional sphere of a person. This invention allows to obtain reliable information about objective and quantitative indicators of energy tension (vigorosity) in the central nervous system (CNS) of a person. The system can be used in all educational institutions, rehabilitation, employment and career centers, as well as psychological assistance rooms for the population to assess the resistance of the human body to harmful environmental influences, to individualize the training load, during preventive examinations and increase the effectiveness of measures for the correction and rehabilitation of psychosomatic disorders.

Currently, a set of issues related to the determinants of human social activity is relevant. With the introduction of computer technology, it became possible to effectively analyze the psychophysiological processes and significant information arrays in real time. This made it possible to create algorithms for guided experiments, on the basis of which fundamentally new methods and means for studying human mental activity were developed.

For the purposes of sociology, psychology, psychotherapy, advertising, security, and to solve many other applied and fundamental problems, methods are needed that would allow us to objectively and quantitatively fix the processes that determine the strength and direction of social activity, the ability to transform the environment, and counteract external factors, to creativity, and, on this basis, to predict the success of training and activities.

A device for determining the psychophysiological state of a person, comprising a sensor block having an electric skin resistance sensor and a photoplethysmogram sensor arranged for contact with human fingers is connected to the inputs of the respective signal conversion channels of the measuring unit, connected by their outputs through, respectively, the first signal processing channel a signal processing unit corresponding to a signal conversion channel for registering an electric skin sop otivleniya and including a digital filter, a differentiator connected in series, a node for determining the parameters of the electrical resistance signal and a person to determine the psycho-emotional state of a person, and a second signal processing channel of a signal processing unit corresponding to a signal conversion channel for registering a photoplethysmogram and including a digital filter, a differentiator, a selection unit RR-intervals, variometer of RR-intervals and analyzer of the state of the cardiovascular system of the person ESA, to the inputs of the analyzer psychophysiological state, and select a combination unit test stimuli affecting human - RF patent №2214166, A61V 5/16, 2003).

The disadvantages of the known devices are low efficiency and lack of information and reliability of the results.

The prototype of the invention is a device for determining the psychophysiological state of a person, containing a sensor unit having an electric skin resistance sensor and a photoplethysmogram sensor connected by outputs to the inputs of the respective signal conversion channels of the measuring unit, connected by their outputs through the first signal processing channel of the signal processing unit corresponding to the signal conversion channel for registration of electric skin resistance and including a follower but the connected digital filter, a differentiator, a node for determining the parameters of the electrical resistance signal, and a unit for determining the psychoemotional state of a person, and a second signal processing channel of a signal processing unit corresponding to a signal conversion channel for registering a photoplethysmogram and including a digital filter, a differentiator, a RR-interval extraction unit in series , variometer of RR-intervals and an analyzer of the state of the human cardiovascular system to the inputs of the analyzer of psychophysio ogicheskogo human condition and the selecting unit is a combination of test stimuli that affect humans. The device has a human functionality analyzer, the sensor unit has a human blood pressure sensor, the output of which is connected to the input of at least one additional signal conversion channel of the measuring unit, connected by the output to the input of an additional signal processing channel of the signal processing unit, including a series-connected node pulsogram extraction from an oscillometric signal corresponding to a blood pressure value, registration unit systolic and diastolic blood pressure and a node for determining the index of blood pressure, while the output of the analyzer of the psychophysiological state of a person and the output of an additional channel for signal processing, which is the output of the registration unit of the index of blood pressure, are connected to the inputs of the analyzer of human capabilities, which is connected to the input of the unit the choice of a combination of test stimuli acting on a person - RF patent No. 42111, A61B 5/16, 2004

A disadvantage of the known device is that the algorithm it implements does not allow to establish the reliability of the received information about the subject. This is due to the fact that there is no feedback in the device, which allows checking the reliability of the test person’s reaction by registering the response on a new stimulus different from the previous or a series of previous stimuli.

The present invention is aimed at achieving a technical result, which is expressed in minimizing the influence of subjective and random factors on physiological reactions when presenting stimuli by adapting the base of semantic stimuli to the subject, in providing the possibility of correction of psychoemotional states by influencing the semantic component by consistently presenting the identified reliable semantic stimuli.

Ultimately, the specified technical result is to increase the efficiency and accuracy of studies of the severity of the psychophysiological components of the individual characteristics of the vigorous activity of the individual.

The specified technical result is achieved by the fact that in the system for measuring the energy tension in the subsystems of the brain, containing an electric skin resistance sensor (RAG), a photoplethysmogram sensor (PPG), a measuring unit, a signal processing unit, the output of the electric skin resistance sensor is connected through the first measurement channel unit, to the first channel of the signal processing unit, including a series-connected filter and a unit for determining the parameters of the signal of electrical skin resistance, connected to the processor unit, performed with the function of demonstrating the parameters of the electric skin resistance on the screen, the output of the photoplethysmogram sensor is connected, through the second channel of the measuring unit, to the second channel of the signal processing unit including a series-connected filter and an RR-interval extraction unit connected to the processor unit made with the function of demonstrating the parameters of RR-intervals on the screen, a unit for selecting a combination of stimuli acting on a person, and an executive unit for demonstrating a combination and stimuli, electroencephalogram sensors (EEGs) are added, connected by their outputs, through the third channel of the measuring unit, to the third channel of the signal processing unit, which includes a series-connected filter and a unit for determining the parameters of these signals, connected to a processor unit designed to demonstrate the parameters of the electroencephalogram on the screen, while the stimulus combination selection unit is configured to generate a series of 80 sound stimuli of different frequencies or a series of 40 sounds of stimuli of the same frequency, the executive unit for demonstrating the combination of stimuli is headphones, the processor unit is designed to display the recorded signals through three channels in the form of graphs and to determine the energy intensity indicators in the brain subsystems for the transmission of electrical skin resistance signals by the signal spectrum power in response 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli, for I channel of the transmission of electroencephalogram signals in terms of amplitudes in response to 10 consecutive sound stimuli with sums from 1 to 10, 2 to 11, 3 to 12 and the end of each series of sound stimuli, and for the signal transmission channel of the photoplethysmogram in terms of the variance of RR intervals in response by 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli.

The present invention is illustrated by a specific example, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the above set of features of the desired technical result.

Figure 1 - elements of registration and conversion of the system for measuring energy tension in the subsystems of the brain by printing registration of components of the orientational reaction;

figure 2 - laptop with a demonstration screen of a system for measuring energy tension in the subsystems of the brain by printing registration of components of the approximate reaction;

figure 3 is a graph of registration of evoked potentials (VP), display on a laptop screen;

figure 4 is a graph of the recorded skin-galvanic reaction (RAG), displayed on a laptop screen;

5 is a graph of a registered photoplethysmogram (PPG), a display on a laptop screen;

6 - dynamics of VP, PPG and RAG in the process of quenching the approximate reaction in response to insignificant (indifferent) sound clicks recorded in 148 subjects.

7 is an example of visualization of the distribution of parameters for a series of surveys;

Fig. 8 is an example of a system for measuring energy tension in

brain subsystems in the form of a block diagram.

According to the present invention, a system for measuring energy tension (vigorosity) in the brain subsystems by printing registration of the components of the orientational reaction is considered.

The main prerequisite for organizing the study of the issue of obtaining information about personality vigorosity was a refined understanding of passionarity and the introduction of a new concept - vigorosity. As a result of research, it was found that in modern psychophysiological, psychological and socio-psychological definitions of passionarity an understanding of two fundamentally different phenomena is hidden.

One of them is socio-historical in nature and manifests itself in the presence in a certain place and at a certain time of a noticeable number of people with special qualities, accompanied by economic, cultural, social, spiritual and other transformations. This is actually passionarity. Another phenomenon characterizes the energy potential of specific people and their desire to participate in a passionary phenomenon, the implementation of passionate transformations, as the whole ethnic group, and its individual groups. Such personality traits do not necessarily lead to passionarity as a socio-historical phenomenon, but are a necessary prerequisite for the latter. In order to separate these two phenomena, it was proposed to designate this personality phenomenon by the term “vigorosity” (from latvigorous - vigorous, strong, energetic) - a personality quality characterized by high energy, activity, desire to achieve a goal and overcome obstacles.

In the course of the research, an understanding of vigorosity as a high activity combined with the peculiarities of the value-semantic sphere was proposed. The principle of activity is currently considered as the basis of modern psychophysiology. Modern studies show that the scale of an individual’s active behavior develops in a continuum, at one end of which there is an approximate reaction (OR) - maximum uncertainty, since the probabilities of all hypotheses are equal, and at the other - a conditioned reflex (SD) maximum certainty: the probability of one hypothesis is equal to one and all the rest to zero. Therefore, if SD is the maximum reactivity of the central nervous system - a fully automated action (stimulus - reaction), then PR is a manifestation of central nervous system activity - the formation of readiness for action in the absence of a highly probable future model.

Thus, the energy resources in the human central nervous system, from the standpoint of modern psychophysiology, are redistributed from the maximum costs of vigorous activity to the costs necessary for stereotyped behavior. This means that the basis for the development of an objective and quantitative scale of energy tension, reflecting the level of vigorosity, should be the PR - the only mechanism known today for the redistribution of energy resources to actively satisfy motivation and achieve significant goals.

According to the classical ideas, an OR occurs when there is a mismatch between the incoming sensory information and the stimulus model formed on the basis of the integration of previously received sensory information - this is the OR for new information. It gradually fades away when the same sensory signal is repeated, because a new model is formed to include this stimulus and the distinction between the stimulus and the model disappears. The limitations of the three-component OR - stimulus, its model and their comparison, is that it is difficult to imagine how the nervous system can perform such a task with a huge number of stimuli entering the brain at any given moment. Important for the understanding of vigorosity is the fact that extinction of OR may not occur if the stimulus, having lost the quality of novelty, remains significant for the subject. It is the significance of the stimulus that determines the severity and generalization of OR in vigoros upon presentation of information directly or indirectly related to the vigorous nature of the activity.

Significance is the most important factor in generating ORs, and a new stimulus triggers ORs only because any new information is potentially significant and may require a change in the nature of active behavior. Thus, the extinction of OR is a very convenient psychophysiological model that reflects the redistribution of energy resources during the transition from the active state of the central nervous system to the reactive one.

The activation component in the OR structure is the earliest and rapidly fading phenomenon. It reflects the direct nonspecific activating effects of the brain stem and thalamus on higher-level subsystems. This component is important, because only with a certain (optimal) severity of it, it is possible to implement such subtle psychophysiological mechanisms as attention, perception, assessment of the novelty of stimuli, fixing pragmatic information in memory, etc. A sharp increase or, conversely, an excessive decrease in the severity of the activation component of the PR disorganizes or blocks learning and memorization.

In animal experiments, it was shown that with irritation of the reticular formation and the nonspecific thalamus, nonspecific activation occurs in the cerebral cortex. This reaction is easily observed by depression of the alpha rhythm (DAR) of the EEG, ECG, PPG and pneumograms (respiration).

Thus, an increase in PPG in response to external influences in a state of calm wakefulness of the test means the attraction of an energy resource to activate a non-specific global level of wakefulness and to provide reactive processes. This means that only the activation component of OR, the functional value of which is associated with the mechanisms of non-specific, involuntary, non-selective, reactive processes, cannot be taken as the basis for developing a scale of energy voltage that provides a high level of vigorosity.

Identification of signs of predominance, for example, reactive attention in a person will indicate disorders associated with attention deficit disorder (ADD). However, to assess the energy stress in vigoros, it is important that the voltage level in the activation subsystem of the brain is optimal.

Evolutionarily active mechanisms of the central nervous system have arisen in connection with the need (in order to save energy) to optimally distribute always limited cellular resources. This can clearly be observed in representatives of different animal species in the process of phylogenetic development. At present, it is generally accepted that the emotional-motivational subsystem is the primary “filter” of incoming information. It authorizes further in-depth processing of information in the event that its significance is established. The work of the emotional-motivational subsystem is provided by the median brain structures that make up the Peipitz circle. An objective and quantitative measure of the activity of the emotional-motivational subsystem of the brain is the presence and severity of the skin-galvanic reaction - RAG. Thus, at the Peipitz circle level, the generalized OR phase ends and, therefore, the implementation of non-specific, reactive, and unjustifiably energy-intensive processes.

During the implementation of active processes, first of all, the significance of the stimulus is determined. Due to this, cognitive activity is concentrated in a significant direction and at the same time is distracted from everything else, thereby achieving a sharp increase in the efficiency of the central nervous system. The cognitive subsystem of the brain is a mechanism for in-depth processing of only the information that was determined to be significant at the previous stage. During the period of the cognitive subsystem, new cognitive skills are developed, existing cognitive skills are integrated to assess the likelihood of a positive result of the body's activity, the optimal scheme of actions is selected and a decision is made. The work of the cognitive subsystem of the brain is provided mainly by cortical-subcortical structures, and the degree of its activation is estimated by the amplitude and latent periods of the late (after 50 ms) components of the evoked potentials - EP (most often by the vertex potential).

Thus, due to the active, rather than reactive, nature of the mechanisms of the emotional-motivational and cognitive subsystems of the brain, they can be taken as the basis for the development of the scale of energy tension of vigorosity. This means that the degree of vigorous stress is a function of three variables simultaneously - RAG, VP and FPG, and for its quantitative assessment, simultaneous (printing) registration of these indicators is necessary.

As a result of studying published data theoretically in individuals with high values of vigorosity, one should expect:

- optimal tension in the activation subsystem of the brain, allowing you to use a wider range of mechanisms from the emotionally motivational and cognitive subsystems;

- increased relative to the norm of tension in the emotionally motivational subsystem of the brain, in response to significant situations and, conversely, a sharp decrease in stress to insignificant;

- increased tension in the cognitive subsystem, providing faster and more detailed processing of relevant information.

Evaluation of the components of the orientational reaction is carried out using a system for measuring energy tension in the subsystems of the brain (vigorosity) by printing registration of the components of the orientational reaction.

The system consists of: a high-speed analog-to-digital converter, a three-channel amplifier, headphones, touch sensors, connecting wires (Fig. 1), an interface and software installed on a laptop (Fig. 2).

The study using the system was carried out according to a specially developed technique. The subjects were in a sitting position, relaxing, with their eyes closed. They were informed that during the study they would produce a series of clicks without having to react to them - a state of calm wakefulness. RAG, VP and FPG were recorded in response to the cheeks delivered with a random inter-stimulus interval of 3.5 to 7.6 s.

RAG according to I.O.Tarkhanov was recorded by non-polarizing electrodes with an area of 5 cm ² . To analyze the RGR, a 4-second fragment was allocated in the recording, which corresponds to 2048 samples at a sampling (digitizing) frequency of a signal of 500 Hz. The interval length of 4 seconds is selected based on the duration of the constant component of the period of occurrence of the sound stimulus.

An indicator of the energy tension in the emotional-motivational subsystem of the subjects was the power of the RAG spectrum in response to 10 consecutive stimuli with sums from 1 to 10, from 2 to 11, from 3 to 12 ... and until the end of each series of sound stimuli.

EPs were recorded monopolarly with silver chloride electrodes in the Cz lead in relation to the potential of the earlobe. The standard technique for extracting EP from EEG was used. The standard technique is also implemented in the polygraph because a large amount of normative material on the characteristics of the EP has been developed with the help of it, which greatly facilitates the control of the cognitive sphere.

An indicator of the energy voltage in the cognitive subsystem of the subjects was the amplitude of N1-P2 EP components in response to 10 consecutive stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 ... until the end of each series of sound stimuli.

There are two varieties of the method for detecting PPG - PPG in reflected light and PPG in transmitted light. The system uses a technique based on reflected light. FPG was recorded standardly with the index finger of the right hand. As an informative parameter when processing the pulse blood filling signal, heart rate variability was chosen, which can be calculated based on the analysis of R-R intervals.

An indicator of the energy voltage in the activation subsystem was the dispersion of R-R intervals in response to 10 consecutive stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 until the end of each series of sound stimuli.

Examples of recorded VP, RAG and PPG are shown in figure 3, 4 and 5, respectively. The duration of the entire recording of electrophysiological parameters was 20-30 minutes.

The implementation of RAG, VP and FPG - the components of the OR recorded by the system in response to the indifferent stimulus (Fig.6) in 148 subjects revealed that the extinction or exponential nature of extinction is natural for all components of the OR. The data are normalized by the magnitude of the first response to the stimulus (ordinate). On the abscissa axis is the sequence number of the summation; from 1 to 10, from 2 to 11, 3-13, etc. At the same time, the extinction decrement of VP and FPG practically do not differ. Although the decrement of the extinction of FIGs after the seventh summation should apparently be considered as an average trend, leveling individual revivals of the FPG components of the OR. None of the registered components of the PR revealed a two-phase nature of extinction, as could be expected from the analysis of published data.

Thus, using the system, you can get a comprehensive picture of the redistribution of energy tensions in the main subsystems of the human brain during the transition from the active state of the central nervous system to the reactive one in response to the presentation of new indifferent stimuli. Moreover, the norm for FPG is:

- serial number of the extinction sum - 7;

- the relative magnitude of the changes in the extinction process - 10%;

- the nature of extinction is close to linear. Standards for extinction of VP are:

- serial number of the extinction sum - 30;

- the relative magnitude of the changes in the extinction process - 20%;

- the nature of the extinction is slightly exponential. Standards for the extinction of RAG are:

- serial number of the extinction sum - 15;

- the relative magnitude of the changes in the extinction process is 55%;

- the nature of extinction is exponential.

Repeated presentation of indifferent clicks caused a gradual decrease in the amplitude of the EP, the power spectrum of the RAG and the dispersion of the R-R intervals of the PPG in all subjects — this is “habituation”. Currently, there are two types of addiction - “fast” and “slow”.

The first of them is defined as a decrease in the severity of the components of the OR within the first series of stimuli (intraserial, Fig.6). Rapid addiction is sharply enhanced due to the regular presentation of stimuli and a decrease in the interstimulus interval (from 3 s or less). It stops when the intensity, duration, frequency, position in the space of the stimulus changes.

The second type of addiction - interservice, is the summation of the processes of "quick" addiction, less associated with the modality of the stimulus, develops regardless of the regularity of presentation of the stimulus and the size of the interstimulus intervals (from 3 s to 33 s), stops when the functional significance of the stimuli, which keep the physical characteristics.

In accordance with the data in the modern scientific literature on the functional significance of fast and slow addiction, this means that during the first test with the help of the system, the following mechanisms are realized in the brain: activation, attention, perception, assessment of the novelty and significance of stimuli and decision-making (fast addictive). Changes from testing to testing (slow addiction) is a reflection of the mechanisms:

memory access, selection of the necessary information, comparison with current activities and also decision making.

These research results were obtained using a system for measuring energy tension in the brain subsystems by printing registration of the components of the orientational reaction.

According to the present invention, a specific implementation of a system for measuring energy tension in subsystems of the brain, presented in the form of a block diagram in Fig. 8, is considered.

The system includes a measuring unit 1 of sensors, consisting of a sensor 2 of electric skin resistance, a sensor 3 of the photoplethysmogram and sensors 4 of an electroencephalogram, a three-channel measuring unit of 5 signals coming from the measuring unit of 1 sensors, a three-channel unit of 6 signal processing, coming from the corresponding sensors of the measuring unit 1, the processor unit 7 of the psychophysiological state of the subject with algorithms for evaluating signals from sensors and plotting on the monitor 8, and the selection unit 9 connected to block 7 mbinatsii sound stimuli acting on the test through headphones 10.

On Fig also shows digital noise reduction filters 11, amplifiers 12, analog-to-digital converters (ADCs) 13, digital filters 14, differentiators 15, block 16 determine the parameters of the electrical resistance signal, block 17 allocation of RR-intervals, block 18 determining the emotional state human, variometer 19 RR-intervals, analyzer 20 state of the human cardiovascular system.

Sensors 2, 3, 4 are connected by outputs to the inputs of the respective channels of blocks 5, 6.

The first channel of blocks 5, 6, corresponding to the signal conversion channel for detecting electric skin resistance, includes serially connected noise reduction filter 11, amplifier 12, ADC 13, digital filter 14, differentiator 15, and electric skin resistance signal determination block 16.

The second channel of blocks 5, 6, corresponding to the signal conversion channel for recording the photoplethysmogram, includes serially connected noise reduction filter 11, amplifier 12, ADC 13, digital filter 14, differentiator 15, RR interval extraction unit 17, RR interval variometer 19 and analyzer 20 human cardiovascular system.

The third channel of blocks 5, 6, corresponding to the signal conversion channel for recording the electroencephalogram, includes a noise-canceling filter 11, an amplifier 12, an ADC 13, a digital filter 14, a differentiator 15, and a human psychoemotional state determination unit 18.

These channels are connected to the processor unit 7, which has the function of demonstrating the parameters of the electrical resistance and RR intervals and the parameters of the signals for the electroencephalogram in the form of graphs and determining energy intensity indicators in the brain subsystems in accordance with the following algorithms:

- for the transmission channel of electrical skin resistance signals according to the power of the spectrum of signals in response to 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli,

- for a signal transmission channel for an electroencephalogram in magnitude of amplitudes in response to 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli,

- for the photoplethysmogram signal transmission channel according to the dispersion value of R-R intervals in response to 10 consecutive sound stimuli with sums from 1 to 10, from 2 to 11, from 3 to 12, and before the end of each series of sound stimuli.

Block 9 of the selection of a combination of sound stimuli is configured to form a series of 80 sound stimuli of different frequencies or a series of 40 sound stimuli of the same frequency.

The Executive unit demonstration of a combination of stimuli is a headphone 10.

The system is designed for simultaneous registration and computer-aided processing of signals of a skin-galvanic reaction (sensor 2 of electro-skin resistance), photoplethysmograms (sensor 3 photoplethysmograms) and electroencephalograms (4 EEG sensors) with the aim of examining the functional organization of the human nervous system. The system is designed for individual and mass screening examinations in the context of modeling stimulating effects (sound stimulation).

The hardware of the system, together with the software module for recording and displaying, provides preliminary conversion, processing of the transmitted data streams in digital form in real time and the output of the registered physiological signals to the display screen (monitor) of the PC (laptop).

The following is an example of a specific implementation of the system shown in figures 1 and 2.

The system consists of a high-speed analog-to-digital converter, a three-channel amplifier, which make up the hardware of the system, headphones (an audio stimulator), touch sensors (an FPG sensor, a CGR sensor) that make up the test unit, and connecting wires (an EEG cable, an interface cable to a PC) ( figure 1), the interface and software installed on the PC (laptop) (figure 2). Technical characteristics of the system are given in table 1.

Table 1 Channel Options Values EEG Number of channels one Input impedance not less than 100 megohms Dynamic range of signal measurement 500 mV to 500 μV Noise voltage no more than 3 mkv Inter-channel attenuation not less than 60 dB Bandwidth 0.2 ... 500 Hz Frequency response not worse than 5% Common Mode Attenuation no less than 110 dB RAG Number of channels one Amplitude of measuring current no more than 50,0 μA Dynamic range of signal measurement 10-100000 ohm Time constant not less than 10 s Upper bandwidth limit not less than 35 Hz FIG Number of channels one Signal recording principle reflective Bandwidth 0.5 ... 35 Hz Computer connection RS-232 (COM port)

Table 2 shows the technical characteristics of the PC.

table 2 OS Windows 95/98/2000 / XP CPU Minimum: 750 MHz Recommended: PENTIUM III and above Memory Minimum: 128 Mb Recommended: 512 Mb HDD Minimum: 10 Gb Recommended: 40 Mb and above Free volume Minimum: 512 Mb hard drive Recommended: 1 Gb Video card Minimum: SVGA Monitor Minimum: 15 ", 60 Hz, dot pitch 0.28 Recommended: 17 ", 70 Hz, dot pitch 0.26 Ports Minimum: 1 serial port (COM) Recommended: 1 parallel port (LPT) and 2 serial ports (COM),

The system provides simultaneous recording of electroencephalogram signals, skin-galvanic reactions, photoplethysmograms and transmission of digital data through the interface module in a PC via RS-232 interface over three channels. Registration of the skin-galvanic reaction is carried out using electrodes made of stainless steel. The electrodes of the KGR, EEG and the PPG sensor have connecting and mounting elements that provide fastening to the body of the subject. EEG electrodes are made in accordance with GOST 25995-83 and are located on the surface of the head and ear.

As part of the system hardware, calibration devices are provided to verify the technical characteristics of the EEG channel. The calibration device for the EEG channel is based on the Wien generator and provides a test signal of 1 mV 10 Hz through the EEG channel. The operation of the calibration devices is provided by the microcontroller and is performed when sending the appropriate commands from the PC. The calibration device is designed to verify the following specifications:

- common mode attenuation coefficient;

- dynamic range of amplification channels of the measuring transducer;

- time constant;

- inter-channel attenuation;

The calibration of the passband of the EEG channel can be performed both using a calibration device, which is part of the hardware, and a specialized functional generator with a frequency range from 0.01 to 10000 Hz. Frequency setting error +/- 0.5%. Error in setting the amplitude of the output signal +/- 3%. The coefficient of nonlinear distortion + 2% according to TU 42-2-561-89.

The noise characteristics of the EEG channel are checked according to the following method: the analog inputs of each channel are sequentially combined and connected to a common point in the circuit, the channel gain is set to maximum. The noise voltage is monitored from peak to peak for each channel.

The preparation of the test subject and the system for recording electrophysiological signals is as follows.

1. Place the RAG registration electrodes on the inner parts of the second phalanges of the index and ring fingers of the right hand.

2. Position the FPG registration sensor at the end of the middle finger of the right hand.

3. Place the previously wetted bridge electrode on the vertex (use an EEG helmet as a mount).

4. Connect the common wire of the EEG channel to the electrode placed on the earlobe.

5. Enable monitoring in the software module.

The control and visualization program is built on a modular type. The main settings of the operating modes of the hardware, visualization of signals and data storage are made using the menu.

To configure external sound stimulation of the hardware, the frequency of the duration and time of occurrence of sound stimuli and the setting of both significant and insignificant sound stimuli are provided. The setup of the series provides that the constant part of the period of occurrence of the stimulus cannot be less than 4 seconds, the time deviation is in the range from 0 to the value of the variable component.

After setting the parameters of the examination and calibration of the device, you can proceed to the beginning of the registration of signals. To do this, it is necessary to activate the monitoring of signals, after which the system will turn on the power of the channels and the values of the EEG, GSR and FIG signals will appear on the screen.

The system has the ability to conduct two types of examinations:

1. Examination with sound stimuli of different frequencies - significant and insignificant incentives. In this case, the subject is presented with a series consisting of 80 sound stimuli provided in random order. The series suggests estimating the number of significant incentives by counting.

2. Examination with sound stimuli of the same frequency - insignificant incentives. In the series, the subject does not evaluate the number of stimuli.

If the series of the current examination was carried out completely, the system will automatically stop recording and allow you to start processing the results. If motion artifacts, areas with a high noise level were noticed in the series, then the program provides the function of editing the source data by rejecting unsuccessful fragments (digital filter).

After processing each of the signals, a window appears in the active panel with a visualization of the distribution of parameters for the survey series. An example of such a window is presented in Fig.7. The analysis allows you to visualize 30 blocks obtained by averaging 40 sound stimuli. Each block contains an average value over 10 stimuli. If the survey is carried out according to Series 80, then the results of calculations on significant incentives are presented. The results thus obtained will be presented in the form of text data.

Depending on the conditions of the selection, responses related to different levels of the auditory analyzer can be highlighted. The entire response of the auditory analyzer can be represented:

- short-latency auditory EP (ASWP) - the first 10 ms;

- medium latent VP (SAVP) - from 10 to 50 ms;

- long-latent auditory EP (DSWP) - more than 50 ms.

In our case, we are dealing with long-latent VPs and analyze the VPs in time up to 500 ms. The time corresponding to 500 ms is 250 samples of the signal, therefore, the sample is analyzed in the range from 0 to 250 samples.

For averaging, blocks of 250 points are selected in sequence, corresponding in time to the occurrence of a sound stimulus.

The general formula for filling the VP array can be represented as:

, when changing 1 in the range from 0 to 250.

Each VP is calculated according to a block of 10 stimuli, and the subsequent VP is recalculated according to the algorithm: removing the first and adding the next to the analyzed block.

To attenuate the contribution of network interference to the signal spectrum, before filtering out the VP, the signal was filtered by a non-recursive digital moving average filter: where , fd = 500 Hz The result of the selection of the VP from the EEG signal is presented in Fig.3. As an informative parameter in the analysis of the RAG signal, its energy characteristic was adopted. To determine it, the following algorithm was proposed. For each stimulus, a 4-second fragment was selected in the analyzed record, including 2048 samples of the signal. An interval of 4 seconds was chosen based on the duration of the constant component of the period of occurrence of the sound stimulus.

The analysis used the spectrum of the RAG signal. The signal fragment was previously processed by a smoothing window of the form to eliminate the edge effects of Gibbs.

At the next stage, the spectral components of the signal were summed in the frequency range up to 10 Hz.

The summation algorithm is as follows:

The lower frequency of the analyzed signal is determined by the observation duration of 4 seconds, which corresponds to a frequency of 0.25 Hz. High frequency analyzed signal 2 Hz. Correspondence of the spectrum samples to real frequencies: 2048 samples corresponds to 500 Hz.

Accordingly, 41 spectrum samples correspond to a frequency of 10 Hz. The formula for determining the signal energy in the range from 0.25 Hz to 10 Hz:

where i are the samples of the signal in the spectral region.

For each stimulus, the characteristic S0.25_10 was determined. For a block of 10 stimuli, the set of characteristics was averaged by the formula:

, where S0.25_10-j is the average energy characteristic over a block of 10 stimuli in a series.

S0.25_10-j is stored in the survey results

Signal Processing FIG.

As an informative parameter in the processing of the pulse blood filling signal, heart rate variability was chosen, which can be calculated based on the analysis of R-R intervals.

To determine the R-R intervals in the PPG signal, an adaptive algorithm for analyzing the first derivative of the signal with a moving threshold was used.

Further, according to the set of RR intervals in the period range between the stimuli, the standard deviation was determined by the formula: where an unbiased estimate of the variance of the heart rate is presented.

The number of cardiac cycles between the stimuli is analyzed and the value of σ for each period is calculated.

For a block of 10 stimuli, the set of characteristics was averaged by the formula:

where σ-j is the average variance of the heart rate over a block of

10 incentives in a series.

σ - j is stored in the survey results.

The present invention is industrially applicable.

The system for measuring energy tension in the subsystems of the brain to determine the psychophysiological state of a person allows to increase the efficiency, reliability and informativeness of determining the psychophysiological state of a person, as well as to predict the level of human vigorous activity.

Claims (1)

A system for measuring energy tension in the subsystems of the brain, containing an electric skin resistance sensor, a photoplethysmogram sensor, a measuring unit, a signal processing unit, while the output of the electric skin resistance sensor is connected through the first channel of the measuring unit to the first channel of the signal processing unit, including a filter and a determination unit connected in series parameters of the electrical resistance signal connected to the processor unit configured to demonstrate parameters of electric skin resistance on the screen, the output of the photoplethysmogram sensor is connected through the second channel of the measuring unit to the second channel of the signal processing unit, which includes a series-connected filter and an RR interval allocation unit connected to a processor unit configured to demonstrate the parameters of RR intervals on the screen, unit selection of a combination of stimuli acting on a person, and an executive unit for demonstrating a combination of stimuli, characterized in that additionally elemental sensors are introduced CTGs connected via their outputs through the third channel of the measuring unit to the third channel of the signal processing unit, including a series-connected filter and a unit for determining the parameters of these signals, connected to a processor unit configured to demonstrate the parameters of the electroencephalogram on the screen, while the stimulus combination selection unit is made with the possibility of forming a series of 80 sound stimuli of different frequencies or a series of 40 sound stimuli of the same frequency, executive bl The demonstration of a combination of stimuli consists of headphones, the processor unit has the functions of displaying the recorded signals through three channels in the form of graphs and determining the energy intensity indicators in the brain subsystems for the electrical resistance signal transmission channel by the signal spectrum power in response to 10 consecutive sound stimuli with summations from 1 to 10, from 2 to 11, from 3 to 12, and until the end of each series of sound stimuli, for an electroencephalogram signal transmission channel in magnitude of amplitudes in response to 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli, and for a signal transmission channel, photoplethysmograms according to the dispersion value of RR intervals in response to 10 consecutive sound stimuli with summation from 1 to 10, from 2 to 11, from 3 to 12 and before the end of each series of sound stimuli.