WO2010107337A1

WO2010107337A1 - Visual field examination device

Info

Publication number: WO2010107337A1
Application number: PCT/RU2010/000075
Authority: WO
Inventors: Вячеслав Николаевич БЕТИН
Original assignee: Федеральное Государственное Унитарное Предприятие Государственный Рязанский Приборный Завод"
Priority date: 2009-03-06
Filing date: 2010-02-18
Publication date: 2010-09-23
Also published as: RU2420223C2; RU2009107942A

Abstract

The invention relates to medicine, more specifically to ophthalmology. The technical result consists in increasing the quality and reliability of information obtainable when examining a patient's visual field. The claimed visual field examination device comprises a body (1) with a handle (18) and a sight hole (16) for the patient to look at a demonstration screen (2), which is mounted in the cavity of the body (1), of luminous spot‑type test objects (4) and fixed luminous test objects (5, 6) arranged in perforated openings of a perforated sector of a sphere (3). The demonstration screen (2), which is composed of translucent material, faces the internal surface of the perforated sector of the sphere (3), is axially symmetric with said sector and repeats the shape thereof. A device (12) for illuminating the demonstration screen (2) is arranged inside the body (1). The radiation sources of the luminous spot‑type test objects (4), fixed luminous test objects (5, 6) and illuminating device (12) are connected to a power supply, control and recording unit (14).

Description

DEVICE FOR STUDYING THE FIELD OF VISION

Technical field

The invention relates to medicine, in particular to ophthalmology, and in particular to perimeters for subjectively detecting the presence of a test stimulus against a specific background, and can be used for early diagnosis of primary glaucoma and other diseases that limit the field of view of the human eye.

State of the art

A device for studying the field of view is known (USSR copyright certificate JVb 1680056, MPK5 A61B 3/024, 1991), including a hemispherical screen with LEDs located on its surface, a fixation optical mark, and also power, control and registration means. The known device is equipped with flanges for rotating a hemispherical screen, which, in turn, allows you to increase the number of test objects presented per unit area of the field of view and, accordingly, improve the accuracy of the study of the patient's field of view.

The known device has the following disadvantages, narrowing its functionality. Firstly, it does not allow to study the extreme peripheral boundaries of the field of view, which is fundamentally important, for example, for the early diagnosis of glaucoma. The limited diagnostic capabilities of the device for studying the field of view are largely due to the inefficient constructive design of the hemispherical screen, the geometric shape of which differs significantly from the geometric shape of the retina, which is not allows you to investigate and receive a response to light irritation of the most extreme peripheral in its location photosensitive elements of the patient’s retina. Secondly, the device according to copyright certificate Ns 1680056 is characterized by rather large dimensions of a hemispherical screen with light test objects, which significantly limits the area of its effective use. In particular, the device cannot be used to check the field of view of bedridden patients and in the field, as well as for self-monitoring at home for patients with glaucoma. A known method for the early diagnosis of open-angle glaucoma

(RF patent Zh2220644, IPC A61 BZ / 024), which is implemented using stationary projection perimeters, in particular, the domestic production perimeter ППП-50. The combination of rather complicated manipulations with the patient’s head partially solves the problem of increasing the studied field of view of the patient.

The main disadvantages of implementing this diagnostic method are the large dimensions of the stationary projection perimeters and the low accuracy of positioning the patient’s eye with respect to the coordinates of the light test objects when turning the head relative to the perimeter.

As the closest analogue to the claimed technical solution for the achieved technical result, a device for studying the field of view (patent RU Ne 2285440, MPK8 A61 B 3/024, 2006) was selected, containing a demonstration screen with perforations and light spot test objects in the form of LEDs for presentation to the patient. The demonstration screen is made in the form of a hollow sphere and is placed with a gap in a sphere-shaped body with a handle, and a fixation light test object for fixing the patient’s gaze is located on the surface of the demonstration screen along its central axis. Viewing window for observation of light point test objects are located opposite the fixation light test object, while the diameters of the body, screen and viewing window are selected in accordance with the horizontal size of the human eye socket.

The disadvantages of the device according to patent RU N ° 2285440 are the insufficient quality and reliability of the information obtained in the study of the patient’s field of vision, which ultimately reduces the quality of early diagnosis of various eye diseases, including early glaucoma. This is explained by a combination of the following factors: - the presence of only one fixation light test object located in the center of the demonstration screen, which does not allow optimizing the number of light test objects (stimuli) to ensure the maximum size of the examined field of view; the absence of a uniform background of adjustable brightness, on which the patient detects stimuli, since these stimuli are located in the perforations of the demonstration screen and are directly facing the patient’s eye, and there are no means for illuminating the demonstration screen in the device.

Disclosure of invention

The technical result, the achievement of which the claimed invention is directed, consists in improving the quality and reliability of the information obtained in the study of the patient’s field of vision.

The specified technical result is achieved by the fact that the claimed device for the study of the field of view contains a housing with a pen and a viewing window for observation by a patient on a demonstration screen installed in the cavity of the housing, light point test objects and a fixation light test object in the center of the demonstration screen. The demo screen faces the inner surface of the perforated sector of the sphere, axisymmetric with him and repeats his form. The device is equipped with one or more additional fixation light test object, as well as a backlight device inside the case, facing the demonstration screen made of translucent material and transmitting radiation from light point test objects and fixation light test objects, which are located in the perforation holes of the perforated sector spheres. The radiation sources of light point test objects, fixation light test objects, and backlight devices are connected to a power supply, control, and registration unit.

The claimed technical solution allows to expand the examined field of view of the patient with a fixed number of light emitters in the perforated sector of the sphere by introducing one or more additional, offset from the center of the perforated sector of the sphere and the demonstration screen of the fixation light test object.

The inventive device for the study of the field of view contains a housing 1 (Fig. 1-3, 5-8), in the cavity of which is installed a demonstration screen 2 (Fig. 2 - 4). The demonstration screen 2 faces the inner surface of the perforated sector of sphere 3 (Fig. 2, 3), in the perforations of which light spot test objects 4 (Figs. 2-4) are placed for presentation to the patient and fixation light test objects 5 (Fig. 2). 2-4) and 6 (Fig. 4). The demonstration screen 2 is axisymmetric to the perforated sector of the sphere 3, repeats its shape and fits snugly to it. The housing 1 has the shape of a truncated cone with an opening angle of, for example, 104 degrees. This body geometry is more optimal compared to the sphere used in the prototype, from the point of view of the structure of the face and more technological, and the selected angle of the cone solution allows you to examine the central (25 degrees) and mid-peripheral (50 degrees) of the patient’s field of vision without any additional measures.

The housing 1 is made of a material opaque to external radiation.

The demonstration screen 2 is made of a translucent material (for example, translucent plastic). Its thickness is selected from the condition of ensuring the necessary brightness and maximum clarity of the boundaries (sizes) of the stimuli - luminous light point test objects 4 presented to the patient. The demonstration screen 2 can be made in the form of a layer of paint and varnish (for example, white matte paint) or a polymer material deposited by spraying on the inner surface of the perforated sector of the sphere 3.

Light point test objects 4 are placed in the perforations of the perforated sector of the sphere 3 located along eight half-meridians with a step of 45 degrees. The minimum number of light point test objects 4 on the half-meridians corresponds to the generally accepted arrangement: after 10 degrees, starting from the tenth degree on each even and starting from the fifth degree - on each odd half-meridian (Fig. 4).

As light sources of light point test objects 4, LEDs can be used directly, then they are placed on a flexible printed circuit board 7 (Fig. 2), mounted on a perforated sector of a sphere 3, or mounted directly in its perforated holes, and electrically connected using wires with a control board 8 (Fig. 2). Light point test objects 4 can also be output apertures of optical fibers 9 (Fig. 3, 5), fixed in the perforations of the perforated sector of sphere 3, while their input apertures are optically coupled to a radiation source, for example, LEDs located on a printed control board, which in turn is installed on the plate 10 (Fig. 3), mechanically connected with the perforated sector of the sphere 3. The output apertures of the optical fibers 9 abut against the demonstration screen 2, projecting the presented stimuli onto it. The radiation generated by the radiation sources propagates through the optical fibers 9 due to the effect of total internal reflection from the walls of the optical fibers. This solution has its advantages, since it significantly facilitates the replacement of radiation sources (in this case, LEDs) and allows, if necessary, to quickly change the color of the glow of light point test objects.

The light point test objects 4 may also be output apertures of the optical fibers 9 optically coupled to the light emitting screen 11 (FIG. 5) as a radiation source, which is, for example, a computer display. The angular dimensions of the stimuli are chosen according to ISO 12866 equal

0.43 degrees.

The number of fixation light test objects - constantly glowing or constantly blinking test objects, on which the patient fixes his gaze during examination, in the inventive device is greater than in the prototype, at least one test object, and one fixation light test object 5 is located in the center of the perforated sector of the sphere 3, coinciding with the center of the demonstration screen 2, and the other - additional fixation test object 6 is shifted relative to the center by a predetermined angle (for example, by an angle lying in the range of 1 - 50 degrees mustache). Fixation light test objects 5, 6 can be made in the form of independent LEDs installed in the perforated sector of sphere 3, or selected from among light point test objects 4.

The use of several points of fixation of the gaze allows you to significantly expand the scope of the field of view without the need for complex mechanical manipulation with the claimed device or moving the patient’s head. When the eyeball is rotated and the gaze is fixed on an additional fixation light test object, the presented stimuli are focused on new points of the fundus displaced to the periphery. By optimizing the location and number of light point test objects and gaze fixation points, fixation light test objects, using the minimum number of emitters, it is possible to fully investigate the most critical and important areas of the patient’s field of vision, that is, not only the central field, but also peripheral - nasal and temporal zones.

In the case 1, closer to the patient’s eye, there is a backlight 12 (Fig. 6), facing the demonstration screen 2. The purpose of this device is to provide illumination of the surface of the demonstration screen 2, eliminating the possibility of radiation entering the patient’s eye. The backlight device 12 can be implemented in the form of LEDs mounted on a printed circuit board, for example, in the form of a ring, electrically connected via wires to the control board 8. The backlight device 12 can be located inside the housing 1 both above and below the front pole of the eyeball the patient. It is advisable to provide the backlight device with a shoulder 13 (Fig. 6) to protect the eyes from the emission of LEDs, while providing a fairly wide viewing angle.

As the radiation sources in the illumination device 12, LEDs can be used that generate radiation in various spectral regions (LEDs of different colors) and create, when alternately or jointly turned on, the background color of the demonstration screen necessary for studying the field of view.

Block 14 power, control and registration (Fig. 1, 8), electrically connected via cable 15 (Fig. 1, 8) with radiation sources light point test objects 4, fixation light test objects 5 and 6, and illumination device 12 are configured to individually control the brightness of each radiation source, which eliminates the spread of their parameters. Unit 14 power, control and registration can be performed, for example, in the form of a personal computer.

For patient observation of stimuli in the housing 1 there is a viewing window 16 (Figs. 2-3, 5, 7-9), in which a nozzle 17 (Figs. 7, 8) can be located, configured to control the distance from the eyeball to the demonstration screen 2. The nozzle can be, for example, a hollow pipe moving along the thread of the housing 1 (Fig. 7), or a set of hollow pipes of various lengths installed in the viewing window 16 of the housing 1 for tight fit. The nozzle 17 “moves” the patient’s eye in relation to the demonstration screen 2, and its use allows the use of the inventive device to patients with various degrees of planting eyes (for example, with deep-set or strongly bulging eyes).

To hold the device during the examination of the patient, the case is equipped with a handle 18 (Fig. 1, 5, 8, 9). The presence of the second additional handle 19 (Fig. 1, 5, 8, 9), located, for example, at an angle of 157.5 degrees to the handle 18, corresponds to the direction of one of the half-meridians and allows you to fix the device and examine the field of view of the patient in a new position of additional fixation light test object shifted by a fixed degree.

The housing 1 is made of two parts of the front 20 and rear 21 (Fig. 9), which are mechanically connected, but can rotate relative to each other. The demonstration screen 2 and the perforated sector of the sphere 3 with light point test objects and fixation light test objects placed therein are installed in the rear part 21 housing 1, the viewing window 16 and the backlight 12 - in front of the housing 20 20.

In the back of the housing, behind the perforated sector 3, a display 22 (Fig. 9 - 1 1), for example, a liquid crystal or LED, can be placed to indicate the results of the field of view, mechanically connected to the housing 1, and electrically to the power supply unit 14, registration and management.

The display 22 is provided with a coordinate grid deposited on its screen, for example, a grid of polar coordinates (figure 10). A translucent blank 23 (FIG. 10, 1 1) can be placed on the display screen 22 to copy the results of the field of view research onto it. For reliable placement of the form 23, the display screen 22 is provided with a shoulder 24 (Fig. 1 1).

On the cable 15, connected to the power supply, control and registration unit 14, there is a “see” button 25 (Fig. 1, 8). The position of the button 25 is selected so that both the patient and the doctor can work with it. This facilitates, in particular, examination of the field of view of patients with limited motor skills.

Brief Description of the Drawings

The claimed technical solution is illustrated by the drawings: in FIG. 1 shows the layout of the device relative to the face of the patient; in FIG. 2 illustrates the implementation of the demonstration screen and the perforated sector of the sphere with light point test objects - light diodes; in FIG. 3 illustrates the implementation of the demonstration screen and the perforated sector of the sphere with light point test objects - output apertures of optical fibers, optically connected with LEDs by iodines; in FIG. Figure 4 shows an example of the location of light point test objects along eight half-meridians and two fixation light test objects; in FIG. 5 illustrates the connection of optical fibers to a light-emitting screen; in FIG. 6 illustrates the organization of the backlight inside the device from the side of the patient’s eye; in FIG. 7 illustrates an example of a nozzle in the form of a hollow pipe; in FIG. 8 shows an example of a device with a housing with two handles; in FIG. 9 shows a device with a display for indicating the results of a visual field examination; in FIG. 10 shows an example embodiment of a device with a display, side view of FIG. 9; in FIG. 11 illustrates an example of a display blank arrangement.

Industrial applicability

The study of the visual field of the patient’s eyes using the inventive device is as follows.

The device is connected to the power supply, control and registration unit 14 (for example, a computer). The patient with the help of the handle 18 holds the device, the examined eye fits snugly to the viewing window. The second eye is closed. The patient fixes his gaze on the central fixation light test object 5 (turned on by a doctor or program) and he is presented with alternating light point test objects - stimuli in the form of luminous points on the surface demo screen 2. The patient or the doctor, using the patient's voice command, using button 28 registers the perception of each stimulus.

In the process of examining the field of view, the doctor (or the computer according to a given program) alternately turns on other fixation points and alternately presents stimuli. If necessary, a more detailed examination of the device with a demonstration screen rotates around its central axis, changing the position of the point of fixation of the gaze and expanding the examined field of view of the patient. The demonstration screen can be rotated by one or more predetermined angles by rotating parts of the housing relative to each other, or by a fixed angle by intercepting the device using the second additional handle 19.

After presenting all the stimuli with different points of fixation of the gaze, the received information from the patient (“saw” / “not seen”) is processed, the results of the study are analyzed, and an appropriate diagnostic conclusion about the condition of the patient’s visual system is made.

The use of various combinations of spectra of radiation sources of light point test objects, fixation light test objects and illumination means of a demonstration screen (for example, the same emission spectrum of light point test objects and a backlight device, or the emission spectrum of fixation light test objects, which differs from the spectrum of light point test

Λ objects and backlight devices) further extends the diagnostic capabilities of the claimed device.

Claims

CLAIM

1. A device for studying the field of view, including a power supply, control and registration unit and a case with a pen and a viewing window for patient observation on a demonstration screen installed in the cavity of the case, light point test objects and a fixation light test object in its center, characterized the fact that the demonstration screen faces the inner surface of the perforated sector of the sphere, is axisymmetric with it and repeats its shape, and the device is equipped with one or more additional fixation light test object volume and illumination device inside the case, facing the demonstration screen made of a translucent material and transmitting radiation of light point test objects and fixation light test objects, which are located in the perforation holes of the perforated sector of the sphere, and radiation sources of light point test objects, fixation light test objects and backlight devices are connected to the power supply, control and registration unit.

2. The device according to p. 1, characterized in that the light point test objects are output apertures of optical fiber optical fibers that are optically coupled to radiation sources.

3. The device according to claim 1, characterized in that the fixation light test objects are selected from among light point test objects.

4. The device according to claim 1, characterized in that the power supply, control and registration unit is configured to individually control the brightness of each radiation source of light point test objects, fixation light test objects, and a backlight device.

5. The device according to p. L, characterized in that they use various combinations of spectra of radiation sources of light point test objects, fixation light test objects and means for illuminating the demonstration screen.

6. The device according to claim 1, characterized in that the housing is equipped with an additional handle.

7. The device according to p. 1, characterized in that in the viewing window of the housing is a nozzle that adjusts the distance from the eyeball to the demonstration screen.

8. The device according to p. 1, characterized in that it is equipped with a display to indicate the results of the study of the field of view, mechanically associated with the body.

9. The device according to p. L, characterized in that it is equipped with a stimulus perception registration button.