RU178128U1 - AUTOMATED PROGRAMMABLE DEVICE - Google Patents

Abstract

This device relates to medical equipment, namely to devices for evoking evoked potentials for diagnostic and research purposes. The technical result of the use of the device is to create the possibility of the occurrence of evoked potentials and their simultaneous registration on the electroencephalogram. The technical result is achieved in that the device contains a programmable microcontroller and has connectors for connecting external stimulation devices and an electroencephalographic recorder. The device operates as follows. For the occurrence of evoked potentials and their registration, the device simultaneously sends a signal (s) to both external stimulation devices and an EEG recorder that is connected to a computer. During the experiment, the EEG of the subject's brain is removed. At the moment of giving the subject an external stimulus, this stimulus is recorded on a separate EEG channel. Depending on the type of experiment, stimuli of various nature (sound, light, signs) have their own mark on any separate EEG channel of the recorder involved in the device. At the same time, labels of different stimuli are fed to different channels. Thus, with further analysis of the EEG, the researcher receives the exact time of the external stimulus given, after which he can determine the response time of the brain to this stimulus. Also, depending on the experiment, due to this, it can fix the moment of the response of the test person to external stimulation. Subject's response to an external stimulus is recorded using a gamepad connected to the device.

Description

This device relates to medical equipment, namely to devices for evoking evoked potentials for diagnostic and research purposes.

Currently, studies of evoked potentials using electroencephalography are developing [1]. Evoked potential is an electrical reaction of the brain to an external stimulus or to the fulfillment of a mental cognitive task [2]. To conduct experiments to detect a motor reaction, a device is required that is connected to an electroencephalographic recorder (EEG recorder) at the time of the experiment. The device should combine the functions of supplying a signal that is significant for the test signal (light, sound, and others) and the simultaneous installation of a label indicating the time the signal was applied to the electroencephalogram (EEG). At the moment associated with a particular event, for example, by pressing a test subject’s button, an appropriate label should be placed on the EEG. Naturally, this device should be adapted for any existing electroencephalograph and the above research tasks. The device must also be automated and ergonomic.

A device for isolating auditory evoked potentials [3], comprising an acoustic stimulation path, including a sound frequency electrical signal generator, coupled to an acoustic to electrical signal transducer, a brain bioelectrical activity signal receiving path, including a series-connected electrode, amplifier, band-pass filter. Parallel channels are introduced into the interference compensation path.

A device photostimulator [4] is known, comprising a light source with a control unit for the parameters of light pulses, an opaque mask in which two flexible optical fibers are mounted, connected to the light source.

The disadvantages of these devices include the fact that there is no possibility of choosing the stimulus given to the subject. There is also no possibility of creating a stimulation program to automate the stimulation process with the possibility of choosing not only the type of stimulus, but also setting a specific sequence of alternating stimuli with certain pauses between them. The lack of automation of the programmed stimulation process leads to the addiction of the test subject to an external stimulus, and as a result to weakening the reaction of the brain to this stimulus, which reduces the frequency of response and impairs informativeness.

Known automated device for recording and analysis of the induced bioelectric activity of the brain of the test subject [5], containing means for influencing the object of study, means for recording responses, including sensors associated with an input / output device with a computer, a photorecorder unit with a control mechanism and a frame marker. The device is taken by us as a prototype.

Its disadvantages include the availability of consumables (film) and the limited ability to automate the stimulation process during the experiment due to the limited mechanical programmer and the inflexible ability to adjust the duration and modality of stimulating signals. There is no direct connection to the EEG recorder and the supply of labels to the EEG at the time of receipt of signals from stimulants, which makes it difficult to record the response time of the brain.

The technical result of the use of the device is to create the possibility of the occurrence of evoked potentials and their simultaneous registration on the electroencephalogram.

The technical result is achieved in that the device contains a programmable microcontroller and has connectors for connecting external stimulation devices and an electroencephalographic recorder.

A programmable microcontroller contains various preset programs in memory, within the framework of which various algorithms for influencing a test subject with external stimuli (sound, light, sign) through external stimulation devices are implemented. Due to the microcontroller, it is possible to automate the stimulation process during the experiment, as well as create unique combined stimulation programs with various stimuli, in different sequences, durations, etc., which prevents the subject from being tired, allows you to create individual stimulation programs for different studies. To change stimulation programs, you need to reprogram the microcontroller using a standard programmer.

The device is directly connected to the electroencephalographic recorder through a channel that was not used when the EEG was taken. When a device is connected in a loop to an EEG recorder, there may be more such channels. On this channel (s) the device applies the corresponding labels.

The device operates as follows. For the occurrence of evoked potentials and their registration, the device simultaneously sends a signal (s) to both external stimulation devices and an EEG recorder that is connected to a computer. During the experiment, the EEG of the subject's brain is removed. At the moment of giving the subject an external stimulus, this stimulus is recorded on a separate EEG channel. Depending on the type of experiment, stimuli of various nature (sound, light, signs) have their own mark on any separate EEG channel of the recorder involved in the device. At the same time, labels of different stimuli are fed to different channels. Thus, with further analysis of the EEG, the researcher receives the exact time of the external stimulus given, after which he can determine the response time of the brain to this stimulus. Also, depending on the experiment, due to this, it can fix the moment of the response of the test person to external stimulation. Subject's response to an external stimulus is recorded using a gamepad connected to the device. The device does not require consumables for its work.

The device is illustrated with graphic material.

In FIG. 1 is a photograph of the front of the device. The following symbols are shown in the photo:

1 - housing utility model;

2 - liquid crystal graphic display;

3 - function buttons

4 - panel LEDs;

5 - three-stable switch.

Case 1 is designed to protect the utility model from external influences. The liquid crystal graphic display 2 is intended for visual display of commands transmitted by the researcher of the utility model. Function buttons 3 are used to control the device. Using these buttons, it is possible to select stimulation programs through the menu displayed on the screen, determine such stimulation parameters as the duration of the stimuli, their sequence, as well as select the label channel and produce testing and self-testing programs for the device. Panel LEDs 4 are designed to notify about the functioning of a long-term stimulation program, the operation of a utility model from an internal battery, the operation of the device from an external power source. The three-stable switch 5 allows you to turn off the utility model (middle position), power it from the internal battery (upper position) and power it from an external power source (lower position).

In FIG. 2 shows a photograph of the back of the device. The following symbols are shown in the photo:

6 - connector plug external power;

7 - audio output for stereo headphone;

8 - audio output toggle switch;

9 - knob for the volume control of the audio stimulation signal;

10 - connector for connecting a gamepad;

11 - connector for connecting the signaling device of the end of the stimulation program;

12 - connector for connecting a light stimulator;

13 - connector for connecting a device display significant / insignificant signs of incentives;

14 - connector for connecting via cable to the EEG recorder. The connector of the external power supply plug + 9V 6 is designed to power the utility model from external power supplies + 9V. The audio output for the stereo headphone 7 is designed to connect an external stereo headphone. The audio output toggle switch 8 switches the utility model between the internal speaker and the external audio stimulator in the form of stereo headsets. The volume control knob of the audio stimulation signal 9 controls the volume of the stimulation signal. Connectors for connecting external stimulation devices are designed to connect external stimulation devices to the device and include a connector for connecting a gamepad 10, a connector for connecting an end signal to a stimulation program 11, a connector for connecting a light stimulator 12, a connector for connecting a device for displaying significant / insignificant characters- stimuli 13, a connector for connecting via cable to the EEG recorder 14.

In FIG. 3 shows a photograph of the internal arrangement of the elements of the device. The following symbols are shown in the photo:

15 - microcontroller;

16 - control board audio pacemaker;

17 - internal battery or chemical current source at 9V;

18 - tuning resistors - regulators of the liquid crystal graphic display;

19 - tuning resistors - frequency regulators of sound generators;

20 - tuning resistors - regulators of the level of the signal range of channel labels;

21 is a miniature loudspeaker.

The microcontroller 15 controls the device and the peripherals connected to it. The control board of the audio stimulator 16 is designed to accommodate the electronic elements of the audio stimulator. The internal battery 17 is designed to autonomously power a utility model. Trimmer resistors - regulators of the liquid crystal graphic display 18 are designed to regulate the brightness level of the graphic display and the contrast level of the graphic display. Trimmer resistors - regulators of sound generators 19 regulate the frequency of sound generators. Trimmer Resistors — Level Sweep Level Controllers for Channel Label 20 — Adjusts the sweep level of the channel mark signal. A miniature loudspeaker 21 is used to check the level of the audio stimulation signal.

The device operates as follows. The subject is the object of influence in order to identify the response of the brain in the form of temporary averaged characteristics - called potentials. Impacts on the test subject are made by applying external stimuli using external stimulators connected to the utility model. The response of the subject is recorded using a gamepad connected to the device. For the occurrence of evoked potentials and their registration, the device simultaneously sends a signal (s) to both external stimulation devices and an EEG recorder that is connected to a computer. During the experiment, the EEG of the subject's brain is removed. At the moment of giving the subject an external stimulus, this stimulus is recorded on a separate EEG channel. Depending on the type of experiment, stimuli of various nature (sound, light, signs) have their own mark on some particular EEG channel of the recorder involved in the device. At the same time, labels of different stimuli are fed to different channels. Thus, with further analysis of the EEG, the researcher receives the exact time of the external stimulus given, after which he can determine the response time of the brain to this stimulus.

A programmable microcontroller is used as a system control module, which allows controlling stimulation by various types of stimulation devices connected from the outside (sound, light). For full interactivity between the operator and the microcontroller, a full display is selected that displays sufficient information for the operator to perceive. As such a screen, the graphically-alphanumeric liquid crystal indicator was most optimally suited.

A useful model was used to obtain, within the framework of several experiments, for labeling the EEG. The subject was placed in a shielded, darkened room. The researcher preselected one of the programs laid down, then left the room and the experiment began. At the same time, the device gave a certain time for the researcher to leave the room before starting the work of the stimulation program. The device supplied both significant and insignificant sound stimuli during their joint alternate chaotic delivery to the subject in the form of short sound signals with frequencies of 1000 Hz and 2000 Hz. In another experiment, the device allowed for automated stimulation of the test subject by chaotic alternation, consisting of 60 signals, and the following mandatory conditions were met programmatically: 1 - the time between stimuli ranges from 7 to 15 seconds; 2 - ratio insignificant / significant stimuli 1/3, i.e. 25% of the total number of sound stimuli. Also, in another experiment, the supply of each of the supplied sound stimuli was performed with a warning light stimulus, for a random time of 1-3 seconds before the sound stimulus. The patient response was recorded through a gamepad. Due to the simultaneous supply of external signals by the device and affixing appropriate labels to the EEG, it was subsequently possible to analyze the nature of the evoked potentials in the subjects.

The device can be used in the experimental work of research institutes, research laboratories to solve the problems of obtaining and analyzing short-latent and long-latent, significant, insignificant, reflex, cognitive evoked potentials, for research purposes.

Information sources

1. Gnezditsky V.V. The inverse problem of EEG and clinical encephalography (mapping and localization of sources of electrical activity of the brain). - M .: MEDpress-inform, 2004 .-- 624 p.

2. Zenkov L.R. Clinical electroencephalography (with elements of epileptology). / A guide for doctors / L.R. Zenkov. 6th ed. - M .: MEDpress-inform, 2013 .-- 356 p.

3. Pat. SU 1055471 A, A device for the allocation of auditory evoked potentials [Text] / V.P. Ovsyanik, E.A. Bakay, A.A. Baryshnikov and A.N. Vovchinsky - No. 3349890 / 28-13; declared 07.24.81; publ. 11/23/83. Bull. No. 43.

4. Pat. SU 194360, A61B G02C. Photostimulator [Text] / A.P. Belyshev - No. 1053505 / 31-16; declared 02/07/66; publ. 03/30/67. Bull. No. 8.

5. Pat. RU 2266043 C2, A61B 5/0482. Automated device for recording and analyzing brain-induced bioelectric activity

subject [Text] / S.V. Adbertin - No. 2003125211/14; declared 08/06/2003; publ. 02/20/2005. Bull. Number 35.

Claims (1)

 A device for extracting evoked potentials containing control means providing an impact on the object of study, means for inputting and outputting signals to other devices, characterized in that the device has a housing on the front panel of which there is a liquid crystal graphic display for visual display of commands transmitted by the researcher, functional buttons to control the device, panel LEDs to notify about the functioning of the stimulation program, the operation of the device from the source food outlets; a three-position switch that allows you to turn off the device in the middle position, power from the internal battery in the upper position and power from the external power source in the lower position; on the rear panel of the device there is a connector of the external power plug + 9 V, designed to power the device from external power sources; audio output for stereo head phones designed to connect external stereo headphones; an audio output toggle switch that switches the device between the internal speaker and stereo head phones; knob for adjusting the volume of the audio stimulation signal; a connector for connecting a gamepad, a connector for connecting a signaling device of the end of a stimulation program, a connector for connecting a light stimulator, a connector for connecting a device for displaying significant / insignificant stimulus signs, a connector for connecting a recording device; Inside the device there are: a microcontroller that controls the device and the peripherals connected to it; audio stimulator control board designed to accommodate electronic elements of the audio stimulator; internal rechargeable battery intended for autonomous power supply of the device; tuning resistors - regulators of the liquid crystal graphic display, designed to regulate the brightness level of the graphic display and the contrast level of the graphic display; tuning resistors - regulators of sound generators, regulating the frequencies of sound generators; tuning resistors - regulators of the span of the signals of the channel labels, regulating the level of the signal range of the channel labels; miniature loudspeaker for checking the level of audio stimulation signal.

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