RU2645415C1 - Method of simultaneous evaluation of the degree of functional suppression of one eye by the other in the field of fixation of vision and in different points of the vision field and computerized system for its implementation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine, namely to ophthalmology. For simultaneous evaluation of the degree of functional suppression of one eye by another, using the imaging unit, the test objects red and blue are presented on the screen of the monitor to the patient wearing red and blue glasses, the patient is given the task to determine the location of test objects and their color, using the information input unit. Assessment is performed in two steps. With the help of the control unit, in the first stage, the test object is formed in the form of the same size of two squares coinciding in contour with circles adjoining their faces along the vertical axis of symmetry, where the circle of red color is placed on top, and the blue one - downwards with respect to the squares of the same color. In the second step, in addition to the test object formed in the first step, the series of images of test round elements of red and blue colors are presented separately in the pseudo-random order according to their color and coordinate.

EFFECT: group of inventions allows to carry out with a high accuracy the complex assessment of functional scotoma of suppression (FSS) in case of strabismus, evaluation of the competition of visual information from the central zone of the field of vision of the left and right eyes, as well as determining the size and position of the FSS in the binocular field of view due to automation and increasing the accuracy of measurements.

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Description

The invention relates to medicine, in particular to ophthalmology, and can be used to quantify functional suppression scotomas with strabismus.

Functional suppression scotoma (PSF) is the predominant form of sensory adaptation of the binocular visual system to eliminate possible diplopia due to asymmetric position of the eyes with strabismus. PSF is a “blind” area that appears in the field of view of the squinting eye with only two eyes open and disappears with monocular perception (one eye is covered). The appearance of FSP is due to the process of functional blocking of visual information entering the brain from the right or left eye. Scotomas resulting from anatomical defects of the visual analyzer (partial clouding of the optical media, damage to certain areas of the retina and part of the fibers of the optic nerve, etc.) do not disappear under monocular conditions of observation and, as a rule, are characterized by dimensional stability and localization in the field of view, those. qualitatively different from FSP.

To get the most complete picture of the parameters of the PSF, it is necessary to determine the size, shape and position of the PSP in the binocular field of view, as well as an assessment of the density of the PSP and its stability during repeated measurements.

Unfortunately, the existing methods for studying FSP do not make it possible to obtain sufficiently detailed information about its size, shape and localization in the field of view (Shamshinova AM, Volkov V.V. Functional research methods in ophthalmology: M .: Medicine, 1999; Kanski D. Clinical Ophthalmology: a systematic approach / [transl. from English]; 2nd ed .; edited by V.P. Yerichev. Wroclaw: Elsevier Urban & Partner, 2009).

Known methods for studying and restoring binocular vision (orthoptic and diploptic) and devices for their implementation are based on the separation of the visual fields of both eyes, i.e. haploscopy.

The most common way to study the PSF with strabismus is to identify it at synoptophore (SU 331794, Vyazovsky, Grechko, 03/14/1972). The separation of the visual fields of the right and left eyes in this device is carried out mechanically, using two (separately for each eye) movable optical tubes, with the help of which the test subjects are presented with paired test objects for combination and fusion. When examined at the synoptophor, the PSF may correspond to the objective angle of squint (the projection of the right image falls on the macular zone of the right eye, the projection of the left image to the macular zone of the left), the subjective angle of strabismus (the projection of one image falls on the macular zone of the fixing eye, and the projection of the other on peripheral part of the retina of the squinting eye) or be total (occupy most of the field of view of the squinting eye). However, a synoptophore study allows only the transverse angular size of the PSF to be determined, i.e. its borders horizontally. The disadvantage of this method is the mechanical separation of the fields of view, which leads to an increase in the angle of strabismus and reduces the tendency to binocular fusion.

In the patent “Method for research and restoration of binocular vision” (RU 2133103, Rosenblum et al., 05.26.1997), the separation of visual fields is carried out according to the principle of phase haploscopy using liquid crystal glasses. The phase separation in these glasses is achieved by electrical signals synchronized with the reference signal of the computer, which provides alternate supply of right and left stimuli to the display, while objects (representing a stereo pair) are presented with a frequency sufficient to exclude the flickering effect. The presence of PSF is indicated by the lack of volume perception in a patient with strabismus.

The anaglyphic (using red and blue or green filters) method of separation of the visual fields is more convenient and closer to the natural conditions of observation than mechanical, and simpler than the phase (SU 1409266, Helmholtz Moscow Scientific Research Institute of Biomedical Medicine, July 15, 1988). Through red-green glasses, the patient is presented with round eyes from a distance of 30-35 cm with round luminous tests - color anaglyphs through red-green glasses. If the patient has PSF, he does not perceive one of the test objects. The disadvantage of this method is that it does not make it possible to assess the size, shape and position of the FSP in the field of view. Other implementations of the method and device for measuring are known (see, for example, Rychkova S.I., Korolenko A.V. Study of functional scotoma using liquid crystal glasses / SIBERIAN MEDICAL MAGAZINE, No. 6, OCTOBER 2005, pp. 60-61) .

A method for mapping FSP with strabismus is described (Economides JR et al. Perception via the deviated eye in strabismus / J. Neurosci. 2012 Jul 25; 32 (30): 10286-95). Testing with this software package should be carried out in a darkened room. The patient's head should be fixed with a chin. Eye movements of the patient must be controlled by a device for recording eye movements. Testing is carried out in red-blue glasses for dichoptic presentation of incentives. To reduce the crosstalk of the transmission of spectacle filters, stimuli were presented against a randomly-pointed background. Incentives in this software package were circles of red, blue or purple color, presented randomly at certain points on the screen (the distance between the points was 5 degrees, the total stimulus field was 60 degrees horizontally and 30 degrees vertically). After presenting the stimulus, the subject had to answer what color stimulus he saw. Verbal responses of patients are recorded in the computer manually. Incentives were presented for a short time (200 ms), before and during presentation, the subject had to fix the central stimulus (cross, angular size - 1 degree); for each measurement, the fixation cross was either red or blue (that is, fixation was performed with one eye (the randomly dotted background was purple, that is, it allowed binocular fixation). The program has the additional ability to increase the number of test points in the fovea region. on average, testing one patient takes about 40-60 minutes (20 minutes for 250 measurement points, of which 125 for each eye, and the entire measurement is repeated 2-3 times).

Closest to patentable is a method for evaluating FSP and a device for diagnosing and treating a child with strabismus and reduced visual acuity (CN 100348147 C, Van Lipin et al., November 14, 2007 - prototype for both objects). The device is a computerized complex, including a processor, monitor, keyboard, mouse, red-blue glasses, a printer. Built-in software includes the functions of visual diagnostics, therapy and training in the treatment of strabismus and amblyopia. The software sets the random red and blue colors of two images on a black screen and overlays them to form a square inside a square with three-dimensional graphics. Patients are asked to separate two squares (red and blue), to do this, use the standard computer control settings, doctors use the up and down arrow keys, mouse or keyboard. However, the test methodology is difficult for the child and for patients with severe ophthalmopathology.

The technical problem solved by the present invention is to increase the information content and simplify the implementation of means for simultaneously assessing the degree of functional suppression of one eye by the other in the field of fixation of the gaze and at different points of the field of view.

A patented method for simultaneously assessing the degree of functional suppression of one eye by the other involves presenting the patient in red-blue glasses on the screen with images of test objects in red and blue, with the task of the patient to determine the location of the test objects and their color and subsequent analysis of the results.

The difference is that the assessment is carried out in two stages.

At the first stage, the nature of the relationship between visual information from the right and left eye in the center of the binocular field of view or in the area of fixation of the gaze is determined, for which purpose a test object is displayed in the center of the computer screen in the form of the same size of two squares coinciding along the contour with circles adjacent to their faces along the vertical axis of symmetry, with the red circle placed on top and the blue color below the squares of the same color. The patient looks at the screen in anaglyph glasses (with a red filter for the right eye and a blue filter for the left eye). The task for the patient is to fix the gaze on the specified central test object and determine its color. At the same time, they are diagnosed with vision:

one test object of red color - suppression of the patient’s left eye in the central zone of the field of view;

one test object of blue color - suppression of the patient’s right eye in the central zone of the field of view;

two test objects or their parts of red and blue colors - diplopia in the central zone of the field of view;

circles of red and blue, placed above and below the square of an indefinite color - bifoveal fusion in the central zone of the field of view.

Then, at the second stage, the functional suppression of one eye is determined by the other and at different peripheral points of the visual field, for which an additional series of images of test round elements of red and blue color is presented individually in a pseudo-random order around the test object formed in the first stage, and the task for the patient is to fix the gaze on the test object and confirm (by clicking the left mouse button on the computer) the fact of seeing the round element, then, at the end of the series, the number of of each of the seen and missed round elements for each eye separately and form a map of the field of view, while with an amount of more than 15 percent of the missed elements, the functional suppression of one eye by the other is estimated as significant, moreover, the more pronounced the higher this indicator.

The method can be characterized by the fact that the test field of the computer screen is 30 degrees, while the square image has a size of 15 × 15 (mm), and the circles have a diameter of 7 mm, and also that the test round elements have a diameter of 15 mm, their centers are located on concentric circles relative to the central test object.

The method can be characterized by the fact that a series of images consists of 240 elements of red and blue in equal quantities, while the duration of presentation of each element is 2 seconds.

The method can be characterized by the fact that they preliminarily determine and compensate for the strabismus angle of the patient who is in his own glasses, using prisms, the strength of which is selected so that the installation movements of the eyes under conditions of fixation of the object's eye at a distance of 40 cm, in conditions of alternating overlapping of the right and left eyes were absent.

The computerized system for implementing the method according to claim 1 comprises a processor, a monitor with a screen, an information input unit, a control unit associated with a visual information display unit on a monitor screen in the form of images of red and blue colors and red- blue glasses for the patient.

The difference is as follows. A block for selecting the mode of the first and second stages has been introduced, the input-output of which is connected to the information input unit and the control unit, which includes a test object generation module, a series of images of the test circular elements and a field of view map forming module. The visual information display unit in the first stage mode is capable of displaying in the center of the screen a stationary test object in the form of the same size of two squares with circles coinciding along the contour, and in the second stage mode, in addition to the stationary test object mentioned, a series of images of test round elements presented individually by pseudo-random order in color and coordinate, and the information input unit represents a patient console with keys, configured to assign response codes n The first and second stages of documenting the results and the formation of a field of view map in the control unit.

The system can also be characterized by the fact that the test field of the monitor screen is 30 degrees, the test object is in the form of the same size of two squares with circles coinciding along the contour, with the red circle placed on top and the blue circle below the square of the same color, with the image a square has a size of 15 × 15 (mm), and circles have a diameter of 7 mm.

The system can be characterized by the fact that the formation module is configured to form a series of 240 test round elements of red and blue color with a diameter of 15 mm, the centers of which are placed on concentric circles, the presentation time of each element is 2 seconds.

The technical result of the method consists in a comprehensive assessment of the PSF with strabismus, i.e. the degree of functional suppression of visual information from one of the eyes; assessing the competition of visual information from the central zone of the field of view of the left and right eye; as well as determining the size and position of the PSF in the binocular field of view.

The technical result of the system is the ability to automate and improve the accuracy of measurements in the process of determining the size and position of the PSF in the binocular field of view with simplification.

The essence of the group of inventions is illustrated in the drawings, where:

FIG. 1 is an image of a test object of red color for the eye, in front of which a red filter is installed;

FIG. 2 is an image of a test object of blue color for the eye, in front of which a blue light filter is installed;

FIG. 3 - image of the test object observed by the patient with diplopia in the central zone of the field of view;

FIG. 4 is an image of a test object observed by a patient during bifoveal fusion in the central zone of the field of view;

FIG. 5 is a view of a test object in the form of squares with circles for the first stage;

FIG. 6 is a view of a test object and test round elements for the second stage (unfilled circles indicate positions in which a single test round element may appear);

FIG. 7 is a block diagram of an automated device;

FIG. 8 - algorithm for the operation of the control unit;

FIG. 9, 10, 11 - field of view maps to examples of the method.

Pre-determine and compensate for the strabismus angle under optimal optical correction (the child in his glasses) using prisms. The strength of the prism is selected in such a way that when the patient’s right and left eyes are alternately overlapped under conditions of fixation of the object’s eye at a distance of 40 cm, there are no adjusting eye movements. Additionally, the position of light reflexes from the cornea of the child is additionally clarified when the eye is fixed with a glance at a distance of 40 cm

Then, a red filter is placed in front of the patient's right eye, and blue in front of the left eye. The patient with optimal correction (optical and prismatic) should look at the computer screen 10, located at a distance of 40 cm from the eyes.

At the first stage of the study, in the center of the screen 10 for the study of binocular fusion in the central zone of the field of view, foveal vision, test object 12 is presented, consisting of a central red square 121 (15 × 15 mm in size) with an upper red circle 122 (7 mm in diameter) and the central blue square 123 with the lower blue circle 124. The circles 122, 124 are adjacent to the faces of the squares along the vertical axis of symmetry 13. Upon successful fuzzing of the red and blue images, the patient perceives a visual image (Fig. 4), consisting of one central square 125 predominantly red or blue or with an alternating change of red and blue. Moreover, the patient sees a red circle 122 above the common (fuzzy) square 125 and a blue circle 124 under the square. Red 122 and blue 124 circles are thus “marks” for the right and left eye.

If there is suppression in the central zone (see Fig. 1, 2) from the side of either the right or left eye, the patient does not perceive the image of either a red or blue object, respectively. In diplopia, the patient perceives both blue and red objects, but at a certain distance from each other (Fig. 3).

According to the results of this diagnostic stage, conclusions are drawn about the nature of the relationship between visual information from the right and left eye (diplopia, bifoveal fusion, suppression) in the central zone of the field of view.

At the second stage, the patient should fix the gaze of the central test object 12 and note, by pressing the input unit (patient panel), the appearance of additional images of test round elements in red and blue (diameter of the test field is 30 degrees). Test elements are circles measuring 15 mm in diameter. They appear one at a time at different points on the screen 10 in random order. The color of the circles — red or blue — also changes randomly. The duration of presentation of each peripheral test object is 2 s. A total of 120 red (for one eye) and 120 blue (for the other eye) peripheral elements are presented 20. The centers 21 of the test circular elements 20 are placed on concentric circles 22 relative to the test object 12.

The field of view map is automatically filled in the form of an image, which shows which test objects are marked and which are missing (see further Fig. 9-11). When evaluating the results of the study, the number of missed test objects and their localization in the binocular field of view are analyzed.

In FIG. 7 shows a block diagram of an automated system, where: 1 - patient, 2 - glasses with red (R) and blue (B) filters; 31 - control unit; 32 - block selection mode (first or second stage); 33 - block display visual information; 34 - display; 35 - input unit - patient panel with keys K, C, D, B, C; 36 — module for generating test objects; 37 - a module for generating a series of 240 images of peripheral test objects; 38 is a module for generating a field of view map.

In FIG. 8 shows the algorithm for the operation of the control unit of an automated system.

After switching on, a system start signal is generated, which arrives at the mode selection block 32, which initiates the loading of the necessary executive programs and initial data that implements the algorithm of the first diagnostic stage into the control unit 31. Upon completion of the download, the control unit 31, at the command of the operator, generates a permission signal for starting the programs.

In accordance with the algorithm of the first stage, the control unit 31 transmits to the visual information display unit 33 a command to display on the screen 10 from the central red square 121 (size 15 × 15 mm) with the upper red circle 122 (7 mm in diameter) and the central blue square 123 with the lower blue circle 124 formed in the module 36. According to the program executed, the control unit 31 generates a reception permission signal for response codes generated by the input unit 35 (patient panel) by pressing the keys 351 of the block 35.

The patient fixes his gaze on the test object and, depending on the perceived image, presses the corresponding keys 351 of the input block 35:

when the “C” key is pressed, the response code “C” is generated at the output of the input unit, corresponding to the diagnosis: suppression of the patient’s right eye in the central zone of the field of view (perceived image of Fig. 1);

when the “K” key is pressed, the response code “K” is generated at the output of the input unit, corresponding to the diagnosis: suppression of the patient’s left eye in the central zone of the field of view (Fig. 2);

when you press the "D" key at the output of the input block, the response code "D" is generated, which corresponds to the diagnosis: diplopia in the central zone of the field of view (Fig. 3);

when the “B” key is pressed, the response code “B” is generated at the output of the input unit, corresponding to the diagnosis: bifoveal fusion in the central zone of the field of view (Fig. 4).

Upon receipt of the response code in the control unit 31, the response code is stored in the patient file generated in the control unit, after which the control unit 31 generates a second stage trigger signal, which is received in the mode selection unit 32. Block 32 initiates the loading of the necessary executive programs and source data that implements the second stage algorithm to the control unit 31.

In accordance with the algorithm of the second stage, the control unit 31 transmits to the visual information display unit 33 a command for generating a series of 240 images of test circular elements 20, which is executed in module 37.

Each image of the test object consists of one test circular element 20 with a diameter of 15 mm in red or blue. The centers of the 21 circles are arranged on concentric circles 22 for maximum uniform coverage of the test field. An angle of 30 degrees in a series for blue and red circles separately. Total 120 red (for one eye) and 120 blue (for the other eye) peripheral test objects.

Upon completion of the series formation, the control unit 31 generates a pseudo-random sequence of images from the series of test round elements created in the module 37 and transmits a command to the module 36 to display the central test object similar to the test object of the first stage to the visual information display unit 33. According to the executable program, the control unit 31 transmits to the visual information display unit 33 a command to display the next image from a pseudo-random sequence every two seconds. In accordance with these commands, the desired image appears on the screen 10 of the visual information display unit 33 (central test object 12 and one test round element 20).

In accordance with the task given to the patient to fix the gaze on the test object 12 and confirm the fact of seeing the round element 20, the patient should fix the gaze of the central test object 12 and note, by pressing the “B” key of the input unit 35, the appearance of peripheral test round elements 20.

In the absence of pressing the “B” key upon presentation of the test object from the series, the control unit 31 creates a “pass” mark in the patient file for the test object. When the “B” key is pressed in the input unit 35, the pressing command is sent to the control unit 31, which creates a “marked” mark for the element 20 in the patient file.

After completion of the presentation of all 240 images from a pseudo-random sequence, the control unit 31 calculates the number of skipped test objects for each eye separately and the module 38 generates a field of view map.

The data of the analysis result is displayed on screen 10 or an additional display (not shown in the block diagram) of the display unit 33 in the form:

- the diagnosis obtained as a result of the first stage: suppression of the patient’s left or right eye, diplopia in the central zone of the field of vision or bifoveal fusion in the central zone of the field of vision;

- An image of the map of the field of view, which shows which test objects are marked and which are missing;

- the percentage of missed test round elements for each eye separately, according to which it is possible to assess the degree of FSP: normal 0-5%, weak 6-15%; average 16-20%; a strong 20% or more, in recent cases an indicator of the need for training.

In FIG. Figures 9-11 show examples of examinations of three patients, where: 3 - areas in which the patient noticed test objects corresponding to the right eye and test objects corresponding to the left eye; 4 - zones in which the patient noticed only test objects corresponding to the right eye; 5 - zones in which the patient noticed only test objects corresponding to the left eye.

Example 1. Map of the field of view of the patient S.A., 7 years old (Fig. 9).

The patient perceives only part of the central test object corresponding to the right eye. The patient did not notice 10 test round elements (one to the right, the other to the left of the central test object and 8 in more peripheral zones) corresponding to the left eye; the patient did not notice 10 test round elements corresponding to the right eye. A total of 20 test round elements were missed in the binocular field of view.

The shape of the FSP is complex, the size of the FSP in the binocular field of view is 1538 square meters. mm for the right eye and 1691 sq. mm (including the central zone of the field of view) for the left eye.

Based on the obtained parameters, a preliminary diagnosis was established: friendly (non-paralytic) alternating strabismus converging with the vertical component, hyperopic astigmatism in both eyes.

Example 2. Map of the field of view of the patient S.K., 15 years old (Fig. 10).

The patient perceives only part of the central test object corresponding to the left eye. The patient did not notice 28 test round elements corresponding to the right eye (5 of them are located paracentrally and 23 in more peripheral zones); the patient did not notice 4 test round elements corresponding to the right eye. A total of 32 test round elements were missed in the binocular field of view.

The shape of the FSP is complex, the size of the FSP in the binocular field of view is 4460 square meters. mm (including the central zone of the field of view) for the right eye and 615 square mm for the left eye.

Preliminary diagnosis: inconsistent friendly (non-paralytic) converging strabismus of the right eye only, mild hyperopia of both eyes.

Example 3. Map of the field of view of the patient P.I., 15 years old (Fig. 11).

The patient successfully fuses the part of the central test object corresponding to the right eye and the part of the central test object corresponding to the left eye (perceives the full image of the central test object). The patient did not notice 2 test round elements corresponding to the left eye; and 1 test round element corresponding to the right eye in the peripheral zones. In total, 3 test circular elements were missed in the binocular visual field in the most peripheral zones (307.6 sq. Mm for the right eye and 153.8 sq. Mm for the left).

Preliminary diagnosis: moderate hyperopia of both eyes (without binocular vision impairment).

Claims (18)

1. A method for simultaneously assessing the degree of functional suppression of one eye with the other, including presenting the patient in red-blue glasses on the screen with images of test objects in red and blue, with the task of the patient to determine the location of the test objects and their color, and subsequent analysis of the results, characterized in that The assessment is carried out in two stages: at the first stage, the nature of the relationship between visual information from the right and left eye in the center of the binocular field of view or in the area of fixation of the gaze is determined, for which purpose a test object is displayed in the center of the computer screen in the form of the same size of two squares coinciding along the contour with circles adjacent to their faces along the vertical axis of symmetry, with a red circle placed on top and a blue color below from the squares of the same color; the task for the patient is to fix the gaze on the specified test object and determine its color, while diagnosing it with vision: one test object of red color - suppression of the patient’s left eye in the central zone of the field of view; one test object of blue color - suppression of the patient’s right eye in the central zone of the field of view; two test objects or their parts of red and blue colors - diplopia in the central zone of the field of view; circles of red and blue, placed above and below the square of an indefinite color, - bifoveal fusion in the central zone of the field of view; then, at the second stage, the functional suppression of one eye is determined by the other and at different peripheral points of the visual field, for which an additional series of images of test round elements of red and blue color is presented individually in a pseudo-random order around the test object formed in the first stage, and the task for the patient is to fix the gaze on the test object and confirm the fact of seeing the round element, then at the end of the series, the number of seen and missed round elements is counted entrances for each eye separately and form a map of the field of view, while with an amount of more than 15 percent of the missing elements, the functional suppression of one eye by the other is estimated as significant, the more pronounced the higher this indicator. 2. The method according to p. 1, characterized in that the test field of the computer screen is 30 degrees, while the square image has a size of 15 × 15 (mm), and the circles have a diameter of 7 mm. 3. The method according to p. 1, characterized in that the test round elements have a diameter of 15 mm, their centers are placed on concentric circles relative to the test object. 4. The method according to p. 1, characterized in that the series of images consists of 240 elements of red and blue in equal quantities, while the duration of the presentation of each element is 2 seconds. 5. The method according to p. 1, characterized in that they preliminarily determine and compensate for the strabismus angle of the patient who is in his own glasses, using prisms, the strength of which is selected so that the installation movements of the eyes under conditions of fixing the object’s eye at a distance of 40 cm, alternating overlapping of the right and left eyes were absent. 6. A computerized system for implementing the method according to claim 1, comprising a processor, a monitor with a screen, an information input unit, a control unit associated with a visual information display unit on a monitor screen in the form of images of red and blue colors, configured to exchange information and control and red-blue glasses for the patient, characterized in that a mode selection block of the first and second stages is introduced, the input-output of which is connected to the information input unit and the control unit, which includes a test object generation module, a series of image forming test circular elements and a visual field map generating module, wherein the visual information display unit in the first stage mode is capable of displaying in the center of the screen a stationary test object in the form of the same size of two squares with circles coinciding along the contour, and in the second stage mode, in addition to the stationary test object mentioned, a series of images of test round elements presented individually by pseudo-random order in color and coordinate, and the information input unit represents a patient console with keys, configured to assign response codes n The first and second stages of documenting the results and the formation of a field of view map in the control unit. 7. The system according to claim 6, characterized in that the test field of the monitor screen is 30 degrees, the test object is in the form of the same size of two squares with circles coinciding along the contour, with the red circle placed on top and the blue circle below the squares of the same name color, while the image of the square has a size of 15 × 15 (mm), and the circles have a diameter of 7 mm. 8. The method according to p. 1, characterized in that the formation module is configured to form a series of 240 test round elements of red and blue color with a diameter of 15 mm, the centers of which are placed on concentric circles, the duration of presentation of each element is 2 seconds.

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