RU2771489C1 - Device for registering the pupillary response of the eye - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to the field of medicine. The device for registering the pupillary response of the eye includes a lighting unit, an optical unit, a photographic registration unit and a control unit made with the ability to set the operating modes of emitters for monochromatic illumination with wavelengths of 671 nm, 546 nm and 435 nm and their combinations. In this case, the lighting unit, the optical unit and the photographic registration unit are installed sequentially one after another, their optical axes are located on the same line, forming a single optical axis. Moreover, the optical unit contains a diaphragm, including a liquid crystal display, with the possibility of changing the diaphragm opening in area and in light transmission intensity.EFFECT: application of this invention will improve the accuracy of measurement.7 cl, 5 dwg

Description

The invention relates to medicine, in particular to ophthalmology, toxicology, psychophysiology, and can be used in eye biomicroscopy, namely, the study of pupillary reactions of the eye.

Biomicroscopy allows you to examine the anterior part of the eye, namely: the cornea, the outer shell of the eye, the conjunctiva, the iris, the lens and the study of pupillary reactions. Lighting control provides high detail and contrast of the illuminated and darkened areas of the eye, which creates an optical section.

Known photoelectronic pupillograph (VF Ananin. Reflexology. M. Publishing House of the Russian University of Peoples' Friendship, Biomedinform, 1992, p. 144-145), containing a light stimulation unit, a viewfinder unit, a projection unit with a photodetector, an illuminator unit and an electronic unit.

The disadvantage of the known device is that the illuminator unit, made in the form of an infrared illuminator, containing an incandescent lamp, a condenser and an infrared filter, which creates a thermal effect on the surface of the eye and thereby introduces physiological discomfort in the process of registering the pupillary reflex.

A device for recording a pupillary reflex (RU No. 2066971, 27.09.1996, A61V 3/10) is known, containing an illuminator unit, a viewfinder unit and a projection unit, optically and mechanically interconnected, a light stimulation unit optically coupled to the optical axis of the projection unit, an electronic unit electrically connected to the light stimulation unit, the illuminator unit, the photodetector of the projection unit and the electro-optical converter of the viewfinder unit. The illuminator unit is made in the form of a set of infrared light-emitting diodes placed on an annular frame rigidly connected to the lens of the projection unit and optically conjugated with the eye of the subject. The light stimulation unit is a LED operating both in the background illumination mode and in the pulsed light flash mode, in the optical axis of which there is a plate with a fixation point made at the intersection in the optical axis of the projection unit, the light stimulation unit and the visual axis of the subject.

The disadvantages of this device are the possibility of registering the diameter of the pupil and the subsequent issuance of a conclusion as a variant of the norm and deviation from the norm without more detailed analysis results. The use of backlight sharply reduces the information content of the examination, since the retina reacts to any light exposure, including in the near infrared range. The use of a fluorescent lamp leads to constriction of the pupils as a reaction to a non-standardized exposure.

As a prototype, an illuminator device for the anterior segment of the eye (RU 175913, class A61V 3/10, 12/22/2017) is considered, containing an illuminator unit, a photographic recording unit, optically and mechanically interconnected, a light stimulation unit optically coupled to the optical axis of the projection block, a control unit electrically connected to the light stimulation unit, the illuminator unit. The illuminator includes a matte reflector in the shape of a truncated torus, configured to form uniform illumination of the anterior segment of the eye with diffused light, a protective screen with a hole whose diameter is smaller than the outer diameter of the reflector, a hood located above the protective screen and configured to limit the external light flux. The emitters are evenly distributed in a circle under the protective screen. The control unit is configured to programmatically set the operating modes of the emitters for monochromatic illumination with a wavelength of 671 nm, with a wavelength of 546 nm and 435 nm.

However, the known device has insufficient lighting contrast, the impossibility of regulating the light flux and selective illumination in the region of the periphery of the iris and the pupillary zone of the anterior segment of the eye, due to which this device has limited diagnostic capabilities of eye biomicroscopy.

The problem to which the invention is directed is the development of a device for recording the pupillary reaction of the eye, with the possibility of selective illumination in intensity and area, of the anterior segment of the eye, to assess the dependence of the pupillary reaction on the intensity of light exposure, and also to determine the synchronism parameter of the pupillary reaction to light exposure by the effect of the eye reflex to a bright red glow in the pupil area under direct illumination of the fundus, that is, by the effect of light reflection from the retina.

The technical result of the invention is the expansion of diagnostic and functional capabilities, increasing the measurement accuracy.

The technical result of the invention is achieved due to the fact that the device for recording the pupillary reaction of the eye includes an illumination unit, a photographic recording unit, an optical unit and a control unit configured to set the operating modes of emitters for monochromatic illumination with wavelengths of 671 nm, 546 nm and 435 nm and their combinations. According to the invention, the illumination unit, the optical unit and the photographic recording unit are installed sequentially one after the other, their optical axes are located on the same line, forming a single optical axis. The optical block contains a diaphragm, including a liquid crystal display, with the possibility of changing the diaphragm opening in terms of area and light transmission intensity.

The control unit is configured to set the operating modes of the lighting unit and the parameters of the aperture of the optical unit.

The photographic recording unit is configured to obtain digital images of the pupil of the eye.

A single optical axis when registering the pupillary reaction of the eye is aligned with the center of the pupil of the eye of the subject.

The illumination unit is made with the possibility of selective illumination of the zones of the anterior segment of the eye, along the contour of the periphery of the iris and pupillary zone, as well as along the meridians.

The diaphragm is made with the possibility of light transmission from 0 to 100%.

The diaphragm is made with the possibility of changing the aperture opening along the meridians of the eye.

The location of the optical axes of the illumination unit, the optical unit and the photo registration unit sequentially one after another, on the same line with the formation of a single optical axis, ensures the correct formation of the image and the determination of the geometric parameters of the anterior segment of the eye, iris, pupillary zone for real measurements of parameters, improves focusing accuracy the center of the pupil of the eye, which should coincide with the single optical axis of the device, which has a positive effect on the reliability of the data obtained in the diagnosis of the examined eye during biomicroscopy.

The presence of a liquid crystal display in the optical unit provides both a complete overlap of the light flux and the ability to control the intensity of the light flux within the limits necessary for examining the eye. Complete closure is necessary to assess pupillary dilation as a response to the absence of light exposure. Adjusting the parameters of the intensity of the light flux provides a new diagnostic level, namely, the assessment of the dependence of the pupillary reaction on the intensity of light exposure.

Liquid crystal display elements, as a rule, have linear dimensions from 0.05 to 0.1 mm, which makes it possible to adjust the intensity of the light flux, transparency or the maximum degree of dimming when an electrical signal is applied.

The implementation of the lighting unit with the possibility of selective illumination of the zones of the anterior segment of the eye, along the contour of the periphery of the iris and pupillary zone, as well as along the meridians, provides selective diagnostics of the pupillary reaction of the eye, thereby expanding the functionality of the device.

The performance of the diaphragm with the possibility of light transmission from 0 to 100% allows for diagnostics in a wide range of steam meters, also increasing the reliability of the results in biomicroscopy of the eye of the subject.

The device for recording the pupillary reaction of the eye is illustrated in the following drawings, where in Fig. 1 shows a functional diagram of the device; in fig. 2 - examples of illumination parameters of the anterior segment of the eye in terms of light transmission area, where 2a - complete darkening, the diaphragm is completely closed, 2b - darkening by 50%, 2c - darkening by 25%, 2d - no darkening; in fig. 3 – examples of selective shading in the center of the pupil, 3a – shading diameter 2.5 mm, 2b – shading diameter 3.5 mm, 3c – shading diameter 9 mm; in fig. 4 - darkening of the diaphragm on the periphery of the pupil, 4a - darkening in the center, 4b - darkening along the periphery; in fig. 5 - shows the reaction of the pupil of the eye to light passing through the diaphragm with a different opening area, 5a - examples of matching the diameter of the diaphragm with the diameter of the pupil.

The device for recording the pupillary reaction of the eye includes a lighting unit 1 installed one after another, an optical unit 2 and a photo registration unit 3. The optical axes of the lighting unit 1, the optical unit 2 and the photographic recording unit 3 are located on the same line, forming a single optical axis 4 of the device, which, when registering the pupillary reaction of the eye, is aligned with the center of the pupil 5 of the subject's eye. The optical unit 2 contains a diaphragm 6, including a liquid crystal display (not shown in Fig.). The diaphragm 6 is configured to regulate the diaphragmatic opening 7 and includes meridians 8 located along the periphery of the diaphragm 6. To control the process of registering the pupillary reaction of the eye, the device includes a control unit 9 associated with the lighting unit 1, the optical unit 2 and the photographic recording unit 3.

The device for recording the pupillary reaction of the eye works as follows.

When examining the pupillary reaction of the eye, a single optical axis 4 is combined with the optical axis of the center of the pupil 5 of the eye of the subject. The focal length to the plane of the iris should be at least 20 mm, which ensures the safety of the examination, minimizes optical aberrations and centering the optical system relative to the plane of the iris. The diameter of the diaphragm opening 7 of the diaphragm 6 of the optical block 2 corresponds to the diameter of the iris plane, which averages 10.0 mm ± 1.0 mm. The optical system is pre-calibrated on standard tests with a tolerance of 0.1 mm. Illumination of the anterior segment of the eye and the pupillary zone is carried out by the illumination unit 1 through the optical unit 2. To study the pupillary response, monochromatic light stimuli with a wavelength of 671 nm (red), with a wavelength of 546 nm (green) and 435 nm (blue) are exposed. These light stimuli can be used alone or in combination, which in this case provides white light. As a result of using this method, there is a previously unavailable possibility of a selective reaction of the components of the central zone of the retina to a light stimulus with different wavelengths, which significantly expands the diagnostic possibilities in the study of pupillary reactions. In accordance with the three-component theory of color vision by G. Helmholtz, there are three types of cones in the human retina, each of which is most sensitive to light of a certain wavelength: to the red, green and blue parts of the light spectrum, that is, it corresponds to three "primary" colors. The existing analogues use white color, which is a mixture of different wavelengths in the range of 360-780 nm. This is a non-specific light exposure that is difficult to standardize. The use of the above frequencies has a high standardization. In this case, the study is carried out in 3 ranges, respectively, the accuracy of the study increases .

The measurement of pupillary reactions consists in matching the sizes of the pupil 5 and the diaphragm opening 7 of the diaphragm 6, which is determined by the area of the liquid crystal elements of the diaphragm 6. Based on the known parameters of the transparency of each liquid crystal element of the diaphragm 6 and its localization, by summing them up, information is obtained on the geometric parameters of the diaphragm 6. The results are compared the effect of lighting on the eye passing through the specified geometric parameters of the diaphragm 6. When certain geometric parameters of the diaphragm opening 7 of the diaphragm 6 are reached, an eye reaction is observed, which determines the result of the effect of lighting on the eye using the photographic recording unit 3 for obtaining digital images and subsequent data processing.

This device allows selective illumination of the periphery of the iris, in which only the area of the iris from the periphery to the pupillary border is illuminated. The central region of the pupil is closed by the diaphragm 6. Such an impact on the pupil 5 of the eye makes it possible to determine the initial diameter of the pupil 5, which is necessary as a starting point for measuring the reaction of the eye to various light effects. The use of a liquid crystal diaphragm 6 allows you to select the desired option for the illumination zone of the pupil 5. This illumination option eliminates the need to use infrared illumination of the entire zone of the anterior segment of the eye. By adjusting the diaphragm 6 using the control unit 9, it is possible to obtain selective illumination of various zones of the anterior segment of the eye, namely, along the meridians 8 and the location in relation to the periphery of the iris and the pupillary zone. Contrasting lighting increases the diagnostic capabilities of biomicroscopy of the anterior segment of the eye. Contrasting is based on the well-known Tyndall effect, increasing contrast makes brightly lit objects stand out in relation to dark ones. In FIG. 5 illustrates how the pupil diameter changes depending on the illumination parameters of the central zone of the retina. The pupillary reflex is unconditioned and is not controlled by the will of the subject. A prerequisite for obtaining a pupillary reflex is the coaxial arrangement of the lighting unit 1, the optical unit 2 with the optical center 5 of the eye and, accordingly, the central zone of the retina of the lighting system and the photographic recording unit 3. Such a coaxial arrangement is necessary to improve the efficiency of the results of the study of pupillary reactions. Since the pupillary reaction rate is quite high, it is necessary to ensure adequate data processing speed. To do this, the change in the pupil diameter is implemented by the method of combining with the diameter of the diaphragm 6. Since the diameter of the diaphragm 6 is known and is a function of the number of liquid crystal elements used with a known area of each element, the conversion to the pupil area is possible in real time. This improves measurement accuracy, performance and data objectification.

The use of diaphragm 6 based on liquid crystal elements provides both a complete overlap of the light flux and the ability to control the intensity of the light flux over a wide range. When an electric current enters the liquid crystal layer, it causes their light transmission to change. Having overcome the front polarized display panel, the light encounters a filter in its path, which passes only its red, green or blue component. A cluster of these three colors forms a pixel on the screen. With selective lighting, a wide range of shades can be created. Liquid crystal elements are capable of changing the degree of transmission and, as a consequence, the intensity of radiation affecting the segment of the eye, depending on the control signal of the control unit 9. The selectivity of illumination provides a new diagnostic level, namely, the assessment of the dependence of the pupillary reaction on the intensity of light exposure.

When measuring the pupillary reaction of the eye using a liquid crystal diaphragm 6, it is also possible to determine the synchronism parameter of the pupillary reaction to light exposure and the speed of pupil contraction, by the effect of the eye reflex to a bright red glow in the pupil area under direct illumination of the fundus, that is, by the effect of light reflection from the retina . A sign of displacement along one of the meridians 8 is evidence of a violation of pupillary function as a sign of muscle atrophy or the presence of adhesions. In such a study, the central region of the pupil is closed with a diaphragm 6, in which, using the meridian 8, various zones of the anterior segment of the eye are selectively illuminated. Such a measurement is necessary for image contrast in biomicroscopy of the eye.

Complete closure is necessary to assess pupillary dilation as a response to the absence of light exposure. In FIG. Figures 2, 3 and 4 show examples of using the application in the variant of complete (100%) dimming of the diaphragm 6, that is, the exclusion of external light exposure. In this case, pupil dilation is provided, which is necessary in the study of pupillary reactions. Changing the degree of light transmission of the diaphragm 6 makes it possible to quantify the pupillary response to changing light exposure. This technique for studying pupillary reactions allows us to study in more detail the relationship between a changing illumination parameter and a change in pupil diameter. An example is shown (FIGS. 2b, 2c, and 2d) using 50%, 25%, and 0% pupil area illumination, respectively. It is possible to determine the pupillary response in a dynamic version by comparing the pupillary response to the parameter of full blackout (Fig. 2a) and full light transmission (Fig. 2d) or in a more graduated version. Adjustment of the parameters of the intensity of the light flux provides a new diagnostic level, namely, a quantitative assessment of the pupillary response to changing light exposure. The interval of change in pupil diameter is from 1.5 to 9.0 mm. Examples of changes in pupil diameter are images 3a, 3b, 3c respectively, pupil diameters are 2.5, 3.5 and 9 mm. Selective darkening in the center allows you to quantify the pupillary response and produce a more contrast image of the iris based on the Tyndall effect. The possibility of dimming the diaphragm on the periphery provides several positive qualities - a selective effect on the pupillary area, that is, the study of the pupillary reaction in the most common version. The change in pupil diameter can be immediately evaluated in accordance with the area of the illuminated area as a function of the number of liquid crystal elements. An additional advantage is the high rate of registration of pupillary reactions, since this is provided by the control electronic control unit 9. All of the above options for using the liquid crystal diaphragm 6 can be performed at the discretion of the physician, sequentially or in various combinations. The use of these options for the study of pupillary reactions significantly increases the information content of the method and device, ensures the implementation of the goal - expanding diagnostic and functional capabilities, increasing measurement accuracy.

The device for recording the pupillary reaction of the eye is made at the level of a prototype.

Claims (7)

1. A device for recording the pupillary reaction of the eye, including an illumination unit, an optical unit, a photographic recording unit and a control unit, configured to set the operating modes of emitters for monochromatic illumination with wavelengths of 671 nm, 546 nm and 435 nm and their combinations, characterized in that that the illumination unit, the optical unit and the photographic recording unit are installed in series one after another, their optical axes are located on the same line, forming a single optical axis, while the optical unit contains a diaphragm that includes a liquid crystal display, with the possibility of changing the diaphragm opening in terms of area and transmission intensity Sveta. 2. The device according to claim. 1, characterized in that the control unit is configured to set the operating modes of the lighting unit and the parameters of the aperture of the optical unit. 3. The device according to claim. 1, characterized in that the photographic recording unit is configured to obtain digital images of the pupil of the eye. 4. The device according to claim. 1, characterized in that a single optical axis when registering the pupillary reaction of the eye is aligned with the center of the pupil of the eye of the subject. 5. The device according to claim 1, characterized in that the lighting unit is configured to selectively illuminate the zones of the anterior segment of the eye, along the contour of the periphery of the iris and pupillary zone, as well as along the meridians. 6. The device according to claim. 1, characterized in that the diaphragm is made with the possibility of light transmission from 0 to 100%. 7. The device according to claim. 1, characterized in that the diaphragm is made with the possibility of changing the diaphragm opening along the meridians of the eye.

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