RU109648U1 - DEVICE FOR DIAGNOSIS OF DISTURBANCE OF COLOR SENSITIVES - Google Patents

Abstract

 1. A device for diagnosing color impairment, containing a generator, a trigger, an emitter in the form of an LED, a brightness controller, characterized in that the generator is a variable frequency generator, mini-displays are introduced into the device to reflect the degree of color perception disturbance, a control button, a remote socket with three-color LEDs red, green and blue, while adjustable variable frequency, trigger, mini-display to reflect the degree of violation of color perception and brightness controls are made on the program Immovable single-chip microcontroller. ! 2. The device according to claim 1, characterized in that the device uses a rechargeable battery with recharge from the network adapter as a power supply. ! 3. The device according to claim 1, characterized in that the programmable microcontroller is connected by its input and output to a USB port for reprogramming the device and transferring data to a personal computer. ! 4. The device according to claim 1, characterized in that the remote bell with three-color LEDs is made in the form of a mask with three-color LEDs.

Description

The utility model is intended for use in medicine, more precisely in ophthalmology, and is used to diagnose patients with congenital and acquired color perception disorders.

Using the claimed utility model, it is possible to diagnose a violation of color perception, during mass screening, at the primary selection commissions of professional suitability (for work in rail transport, in the subway, in aviation, as well as workers whose activities are related to work where normal color perception is required) .

It is known that during the decomposition of white color by a prism into the spectrum of its constituent colors, violet 430 nm, blue 460 nm, green 520 nm, yellow 575 nm, orange 600 nm, red 650 nm and magenta> 650 nm are emitted as the main ones.

It is known that a monochromatic color with an intermediate long wavelength produces a sensation of a mixed color tone, for example: yellow-green at a wavelength> 520 nm and a wavelength <575 nm.

The peculiarity of color sensation is due to the presence in the retina of the human eye of different types of cones containing various photosensitive pigments and differing in spectral sensitivity, which determine the color vision of a person. Primary primary colors (according to international conventions) have the following parameters: red with a wavelength of 700 nm; green with a wavelength of 546 nm; blue with a wavelength of 435 nm.

Violation of color perception, expressed in the inability to distinguish from each other radiation, distinguishable by a person with normal color vision. Such a violation can be congenital or acquired in nature and is called color blindness or color blindness. These disorders can occur at the level of visual pigments and at the level of processing of nerve signals in the pathways from the retina to the visual zones of the brain or in the visual zones themselves.

The methods for studying the color vision of adults are based on testing the following abilities of the subject:

1) to perceive light radiation over all ranges of the visible spectrum - from 400 to 700 nm;

2) equalize the colors of different radiation in accordance with the laws of displacement inherent in normal trichromat.

Where normal trichromatome is understood to mean a person whose three types of cones function in the retina: red; green and blue.

In addition, normally besides cones in the human retina there are sticks that do not significantly affect color vision.

People with only two types of cones are called dichromats, and one type of cones is called monochromats.

Cones, according to their pigments, are called short-wave (S), medium-wave (M) and long-wave (L).

The joint work of three types of cones allows a person with normal color sensation to classify seven colors of the rainbow and distinguish between similar color shades.

It is known that different zones of the human retina differ in spectral sensitivity.

For example, the spectral sensitivity of the central macular region is formed only from red and green cones. Hence, the macular region of the retina is "blue-blind" - dichromatic (Wald G. Blue - blindness in the normal eye // J. Opt. Soc. Am. - 1967. - Vol.287. - P.1289-1292). In addition, the presence of a light-filtering pigment of the macula limits the spectral range in the macular region of the retina, with a spectrum shorter than 470 nm. As a result, color distinction in the macular region fits into an extremely narrow yellow-orange-red range (Zak P. P. “Theoretical Foundations of Spectral Vision Correction. Clinical Physiology of Vision”, Moscow, Publishing House of MBN 2002, p.664).

It is known that congenital disorders of color perception are connected by the genetic apparatus and are accordingly inherited.

There are three types of congenital color vision disorders:

- defect of perception of red color (protan defect),

- defect in the perception of green (deuter defect),

- defect in the perception of blue (tritan defect).

According to the degree of disturbance, each species is divided into abnormal trichromasia, protanopia, deuteropia, and monochromasia.

Congenital color vision disorders occur in 7% of the population, in men 10-15 times more often than women (A.M. Shamshinova, VV Volkov. Functional research methods in ophthalmology. M. Medicine, 1998).

Acquired defects in color vision in the initial stage of the disease often appear in one eye, which is associated with pathological changes in the macular region of the retina or in a violation of conduction in the fibers of the optic nerve. As a result of injuries or surgery on the brain, defects in color perception can also occur in the double eye. As the disease progresses, there is a decrease in visual acuity, a decrease in contrast sensitivity, and a decrease in the critical frequency of flicker fusion (CFSM). By CFSM is meant the maximum frequency of intermittent light radiation at which the eye begins to perceive radiation as a constant.

It is known that CSFM is a function of the light and distinguishing ability of the system, which characterizes the functional mobility (lability) of the visual pathway from the retinal receptors to the brain.

In ophthalmic practice, CFSM serves as a criterion for the diagnosis of a number of diseases, including glaucoma, partial atrophy of the optic nerve, maculadystrophy, congenital high degree of myopia, congenital cone-shaped dysfunction, pituitary tumor and other diseases.

Normally, the CFFF in a healthy person, both in adults and children, averages 41-45 Hz (red light with a dominant wave - 630 nm). However, this value is characteristic only of the macular zone with central presentation of the stimulus. With an increase in the stimulus area, CFSM grows towards the temporal parts of the visual field and reaches 58-60 Hz on the periphery of the visual field (Dependence of local CFSM disorders on the nature of pathological changes in the visual system. M.V. Zueva, I.V. Tsapenko, E.Yu. Zakharova, K.V. Golubtsov, O.Yu. Orlov, Mater. III Moscow Scientific and Practical Ophthalmos Conf. Moscow, 1999. p. 36-37).

With a disease of the organ of vision, the CESF indicators decrease and are more dependent on the type of pathological process in the retina and optic nerve, as well as in the higher floors of the visual system (Fliker fision freguence in ophthalmic express-diagnosis. KVGolubtsov, OYOrlov. Twentth Euopean Conference on Visual Perceprtion Helsinki - Espoo, Finland, 1997, p. 59 .; Features of the use of pulsed chromatic light in the diagnosis and treatment of optic atrophy Shigina N.A., Kuman I.G., Krutov S.V., Golubtsov K.V. / Clinical Ophthalmology. Theme of the issue - Inflammatory eye diseases. 2002. Volume 3, No. 1, pp. 37-40).

Acquired color vision defects can be divided into three classes:

- aging and diseases of the optical apparatus of the eyes,

- diseases of the retina and optic nerve or their nutrition,

- violation or pathological changes in the visual centers of the brain, which often occur as a result of injuries or surgical intervention.

It is known that traditional methods adequately respond to the study of congenital defects in color vision disorders, and for some acquired defects, these methods do not meet the task. Therefore, for acquired defects in color perception, local color stimuli of various colors and sizes are necessary (Shamshinova A.M. V.V. Volkov. Functional research methods in ophthalmology. M. Medicine, 1998).

The weakening of color perception in old age is usually insignificant and is expressed in a change in sensitivity in the blue spectral region and takes the form of tritanopia. In such patients, studies have shown that the CFSM values for blue are reduced, with relatively normal indicators for red and green light. This is due to an increase in the density of optical media and some yellowing of the lens. Since there are very few blue cones in the human retina, compared with red and green, a decrease in light intensity in the blue region of the spectrum can shift color perception towards tritanomaly.

Diabetic patients often show up as tritanomals, resulting in premature yellowing of the lens.

It is known that at the receptor level, congenital disorders are caused by the complete absence of one of the three types of cones or the deviation of their spectral sensitivity from the norm. Accordingly, three forms of dichromasia are distinguished, i.e. the presence of only two instead of three types of cones: (a) protanopia, when there are no long-wave cones (red), (b) deuteranopia, when there are no medium-wave cones (green), (c) tritanopia, when there are no short-wave blue cones. Since the genes of the long-wave and medium-wave pigments are localized in the sex chromosome, the first two forms are sex-related and occur in approximately 1% of men. Tritanopia is not related to sex and is extremely rare.

It is known that deviations of the spectral sensitivity curves of one of the cone types from the norm give three forms of abnormal trichromasia:

- protanomaly,

- deuteromania,

- tritanomaly.

Abnormal trichromasia are more common than dichromosia. The first two forms of anomalies are also associated with gender and in total are found in 6% of men.

Identification of congenital disorders of color vision is carried out using polychromatic tables or devices for the study of color vision - anamaloscopes. Often they are not comparable with the above classification of congenital anomalies.

The accepted division of protanomalies and deuteranomalies into types A, B and C is determined by the number of read pseudoisochromatic tables (for example, from the atlas of Rabkin, Yustova, Ishihara, etc.).

The International Standards Committee for the detection of congenital red-green disorders along with Ishihara tables recommends the use of a spectral anomaloscope.

To diagnose acquired color sensations, tables of the American Optical Company (Hardy-Rand-Ritter) are often used to diagnose abnormalities in the blue-yellow (RY) region of the spectrum.

Another method for diagnosing color sensation disorders is based on measurements of the photopic “visibility” curve. It is measured either by the laborious method of heterochromic comparisons, when the subject is asked to subjectively adjust the brightness of two adjacent surfaces with different color tones, or by the method of flickering photometry, when two compared radiation is applied to the patient’s eye, alternately with a lower frequency of stimulus emission than the critical fusion flicker frequency . The criterion for equality of brightness, two comparable emissions is the absence of flicker. It is known that in order to balance subjectively the green and red radiations, protanopes (people with a reduced perception of red radiation) require a higher intensity of red radiation than green, and deuteranopes (people with a reduced perception of green radiation) require a higher intensity of green radiation compared to red

Normally, the “visibility” curve is determined by the operation of long-wave and medium-wave cones and has the form of an average spectral sensitivity curve of these cones. The deviation of the “visibility from the normal” curve can serve as an indicator of violations in the properties of long-wave and medium-wave cones. The absence of long-wave cones (protanopia) shifts the curve to the short-wave side, and it coincides with the spectral sensitivity curve of medium-wave cones. The absence of medium-wave cones (deuteronomy) leads to a shift in the “visibility” curve to the long-wave part of the spectrum. The deviation in the spectral sensitivity of one of the cone types (protanopia and / or deuteranomaly) also leads to shifts in the “visibility” curve, but to a lesser extent.

Flickering becomes hardly noticeable at a certain intermediate ratio of the intensities of red and green radiation, which corresponds to the equality of the subjective brightnesses of these radiations. That is, with the equal participation of red and green radiation, a flicker fusion occurs, and the subject with normal color sensation perceives it as not flickering yellow light. There arises the so-called point of "silence" at which flicker is indistinguishable.

The shift of the “visibility” curve along the spectral axis relative to the norm indicates which type the patient belongs to.

Since the considered spectral sensitivity curves are fairly standard, there is no need to take the entire curve for diagnostic purposes.

It should be noted that with any method of studying color perception, the illumination of the room where the study is taking place is of great importance, since extraneous light can significantly affect the diagnostic readings and shift the “visibility” curve along the spectral axis in both directions.

According to the international standard (1985), when checking the color sensation in living rooms in living people in the northern hemisphere of the globe, it is proposed to use illumination within 350-500 lux from windows oriented to the north.

However, the spectrum of natural daylight is not constant, therefore, preference is given to artificial lighting of the room, with a bluish-white color "C" of about 330 lux. The use of any fixtures with a yellow light, for example: incandescent lamps leads to a shift in the curve of "visibility".

A device is known for diagnosing color perception (see patent for utility model RU No. 82107, Aydu E.A.I., Golubtsov K.V., Maksimov V.V., Trunov V.G.). This device allows you to identify the degree of color perception disorders in the red-green green region of the spectrum. The disadvantages of the device are its significant cost and the inability to conduct research in the blue-green region of the spectrum.

The closest device is a device for studying color perception disorders (see SU No. 1690665, Maksimov V.V., Gnyubkin V.F., etc.), where the idea of a “flickering photometer” is used - red and green radiation is presented on the test field alternately with a standard frequency of 30 Hz. The disadvantage of this device is that it operates at a standard frequency of 30 Hz, which is significantly lower than the critical fusion flicker frequency. Therefore, it is difficult to determine the degree of color perception disorder in patients with high CFSM, since with high CFSM flickering is noted on the whole scale of the “visibility” curve, and in people with low CFSM, flicker is not found on the whole scale.

The basis of this utility model is the task of creating a simple device designed for the diagnosis of patients with congenital and acquired impairment of color perception. The device allows diagnosing patients with normal and abnormal trichromasia, dysfunction in two forms: protanopia and deuteronomy, detection of monochromatism, when only one type of receiver is functioning and color discrimination is completely absent. Using the device, it is possible to study pathological processes in the visual system in patients with diabetes with darkening of optical media and to identify patients with signs of tritanomaly.

The device also conduct studies of CSFM in the macular region of the retina for various colors.

The inventive device for the diagnosis of color sensing disorders, contains a reference frequency generator, counting trigger, a red and green emitter, made in the form of a two-color LED, brightness control. A distinctive feature is that the device has an adjustable variable frequency generator, a standard pulse generator, an indicator of the frequency and degree of color perception violation in the form of a display, a type of work switch, an external bell with a three-color LED, red, green and blue, a light protection mask with three color LEDs red, green and blue, control buttons, moreover, a variable frequency generator, a trigger, a standard pulse shaper and current regulators are made on a programmable monocris microcontroller.

Also, in the inventive device, as a power supply, a rechargeable battery with recharging from a network adapter can be used, a programmable microcontroller can be connected with its input and output to a USB port for reprogramming the device and transferring data to a personal computer.

The research procedure with congenital color vision disorders on this device is as follows: first, the critical flicker fusion frequency is determined using a light mask in which the red, green and blue LEDs are inserted. The average values of CFSM for red and green stimuli are fixed and based on the data obtained, a frequency of 3-4 Hz is selected below the flicker fusion and a color sensation is diagnosed at the received frequency.

Figure 1 presents a diagram of the inventive utility model, in which:

1 - controlled variable frequency generator, 2 - trigger, 3 and 4 - controlled brightness generators 5 - light mask with a three-color diode, 6 - mini-display to reflect the degree of color perception, 7 - device control buttons.

Claims (4)

1. A device for diagnosing color impairment, containing a generator, a trigger, an emitter in the form of an LED, a brightness controller, characterized in that the generator is a variable frequency generator, mini-displays are introduced into the device to reflect the degree of color perception disturbance, a control button, a remote socket with three-color LEDs red, green and blue, while adjustable variable frequency, trigger, mini-display to reflect the degree of violation of color perception and brightness controls are made on the program Immovable single-chip microcontroller. 2. The device according to claim 1, characterized in that the device uses a rechargeable battery with recharge from the network adapter as a power supply. 3. The device according to claim 1, characterized in that the programmable microcontroller is connected by its input and output to a USB port for reprogramming the device and transferring data to a personal computer. 4. The device according to claim 1, characterized in that the remote bell with three-color LEDs is made in the form of a mask with three-color LEDs.