RU1782530C - Appliance for measuring the field of vision - Google Patents

Abstract

Usage: the device provides the ability to measure directly by the patient without the assistance of the field of view operator with increased accuracy while automatically mapping the measurement results on a standard form. SUMMARY OF THE INVENTION: a light mark is formed on LEDs, its movement along the meridian is carried out by the patient himself by turning the helm of the electronic LED switch. In this case, the LEDs are powered from an electronic generator of rectangular pulses of regulated frequency so that a light mark is formed on two adjacent alternately flashing LEDs, and the patient adjusts the position of the mark on the meridian under study to the position when he will see only one of the two LEDs. At this moment, by pressing a button, the patient turns on the mark of the boundary point of view on the map form. The rotation angles of the switchboard helm and the rotation of the study meridian are introduced into the mapping device so that the position of the mark on the field of view map corresponds to the angular position of the light mark on the hemisphere at the moment the mark is turned on. Additionally, the instrument allows the determination of the critical frequency in the idiot of the flicker of a pulsating light source. 1 s.p. f-ly, 4 ill, sl C

Description

The invention relates to medical equipment and can be used for medical diagnostics in ophthalmology, in particular for monitoring vision in the treatment of patients with glaucoma and other eye diseases accompanied by a reduction in vision, as well as for measuring the limiting frequency of visibility of flicker when changing the frequency of flashes of the observed source light, which is necessary for in-depth diagnosis of vision,

A device for measuring field of view (device PNR-1) containing a base with a vertical stand, through

the upper part of which passes the horizontal axis. A dark concave semi-cylindrical screen with a radius of 333 mm with a graduation of 5 ° from the center to the edges is fixed at one end of the axis, and a tablet for sight cards is attached at the other, perpendicular to the axis. The screen is fixed to the midpoint axis so that its midline lies with the axis in the same plane, and the center of curvature of the screen lies on the extension of the axis. A stationary ruler is diametrically located directly above the tablet, graduated in divisions from 0 to 90 ° through 10 °. A slide with a guide can move along the ruler

s |

00

go with

W

about

a nest for a needle or pencil. During operation, the operator moves the test mark along the middle line of the screen in the form of a white circle of a certain diameter, applied to the dark holder, and according to the patient’s report, he counts the position of the mark on the screen at the moment when the patient began to see it when the view was fixed to the center of the screen.

Then the operator sets the slider on the line of the recording device to the position corresponding to the countdown according to the graduation of the screen, and with a needle or pencil makes a mark on the form through the slot on the slider. After that, the operator rotates the screen (and with it the tablet with the form) to a new position and, moving the holder with the mark from the edge of the screen towards the center, determines a new point of view, etc. until completion of the full examination.

The main disadvantage of this device is a large number of sources of measurement errors, a large investment of time for examining a patient

A prototype of the proposed technical solution is the Projection perimeter PRP-bO device, which is a further improvement of this type of device. So the test mark in it (the object) is created by an optical projector projecting the image of the mark in the form of a light spot onto the inner surface of the arcuate screen by rotating the projector relative to the screen. The rotation mechanism of the projector is kinematically connected with a reading and recording device, which eliminates possible errors of the operator1 when reading the position of the mark on the screen and entering this coordinate into the recording device.

The closest in technical essence to the proposed device is a device for measuring vision (PRP-60 device), containing a base with a vertical strut, through the upper part of which there is a horizontal axis, at one end of which a concave semicylindrical screen is fixed at the midpoint an arcuate strip, the middle line of which lies in a plane passing through the horizontal axis. A label projector is attached to the side of the screen and attached to the axis of the screen so that when the screen is rotated about the axis, the projector rotates with the screen. The projector projects a mark in the form of a round spot on the screen and has a mechanism, and moving the mark along the middle line of the screen is carried out by turning it, which the mark can be

placed anywhere in the midline on the inside of the screen. At the other end of the axis there is a reference scale, a screen rotation and a perpendicularly fixed field of view card holder. Above the form, there is a movable bar with a guide hole in the middle, which is kinematically connected with the mechanism for moving the mark on the screen, because the guide hole in the bar moves in diameter, and its offset from the center of the form is proportional to the angle of deviation of the mark on the screen from its central points. At the time of the patient’s report, the operator through the guide hole draws with a pencil or needle marks on the form, the sequence of which, at different angles of the screen, reflect the field of view on the form

0 of the examined eye of the patient. Replacing the form, the operator similarly examines the second gras. To align the eye in the observation hemisphere in the known device, two located

5 at an angle of the direction of the light source, the rays of which intersect in the center of the hemisphere, where the patient places the test eye, and there is an auxiliary weak one to fix its view in the center of the screen

0 light source that the patient should look at during the examination.

The main disadvantage of the known device is the long duration and complexity of the examination of the patient.

5 An object of the invention is to reduce the examination time of a patient.

In FIG. 1 and 2 schematically depict a general view of a possible embodiment of the claimed device (front view and side view);

0 in FIG. 3 - automatic recording device; in FIG. 4 is an electrical functional diagram of the entire device.

The device consists of (see Fig. 1, 2) a base with a vertical stand 1, in the upper part of which 5 a horizontal axis is movably placed, bearing on one of its ends a semi-cylindrical concave holder 2 of LEDs 3, which are uniformly

0 are distributed along its middle line, and on the other end is the tablet 4 of the recording and recording device 5. When working on the tablet, the field of view card is fixed. The metering and recording device 5 attached to the rack 1 includes an LED switch with a control knob 6. The LEDs are connected to the switch with a free wire bundle 7, which, when the LED holder 2 is rotated, is wound or wound on the harness receiver 8, on the axis of the holder 2. On the base of the rack 1, an electronic unit 9 is also installed, comprising a generator 26, a recording pulse generator 13, rectifiers 31, 32 with a power switch 10, a pulse frequency adjustment knob 11, and a switch 12 the left and left groups of LEDs on the holder 2, as well as the button 34 for turning on the drive of the mark in the reading and recording device 5. The reading and recording device 5 (see Fig. 3) contains a plate 14 mounted on a rack 1 below the axis of the holder 2, on which two coaxial axles 16 are movably fixed on bearings 15, along which levers 17 can be moved on the slots, bearing stamps 18 at their ends. The line of possible stamp positions extends along the diameter of the tablet 4 with the field of view card fixed on it, crosses its center. Below on the plate 14 is a switch 19 LEDs. The handle 6 of the switch and the levers 17 are kinematically interconnected by a cable transmission through the rollers 20 and a tension play-back spring 21. When the handle 6 is rotated, the cable 22 fixed on the handle drum moves the levers 17 on the splines along the axis 16. The diameter of the drum on the handle 6, the distance between levers 17 and the position of the sliders on the biscuits of the switch 19 is selected so that when the handle 6 of the switch 19 is in one extreme position, one of the levers 17 holds the stamp over the edge of the card blank, the second lever 17 holds the stamp over the center of the blank and one TERM switches the switch 19 is energized through switch 12 to the extreme two LEDs of one group or central LEDs of the second group (the switch 12 depending on the position). When the handle 6 is rotated to another extreme position, the levers 17 move in the reverse order, i.e. the former on the edge of the form moves to the center, and the former on the center goes to the edge, and the switches of the switch 19 respectively reverse the LEDs of the groups.

At the outer ends of the axles 16, levers 23 are fastened, which carry the retractable cores 24 of the solenoids 25 at the ends. The solenoids 25, when the button 13 is pressed through the switch 12, are connected to the storage capacitor, the discharge of which causes the core 24 to be pulled once, the rotation of the corresponding axis 16, and accordingly the impact a stamp through the copy tape on the card form on tablet 4, creating a mark on it. The switch 12 provides a correspondence between the group where the LEDs are on and the connected solenoid 25.

The device can be made for 5 eye examinations with one color of a label and with labels of two colors. In the first case, on the holder 2, all the LEDs of one (e.g., yellow) glow. In this case, during the examination it is enough to rotate the holder 2 within an angle of 180 °, using the switch 12, sequentially conduct the examination on one half (group) of LEDs, and then on the second.

5 In a two-color device, the study on which can provide additional information, the LEDs on one half of the holder 2 are set to the same color, and on the other half to the other color of the glow. In this case, during the examination, the holder is rotated 360 ° on each color, and the color of the examination is changed switch 12. To distinguish on the accessory card form

5 marks for the color of the inspection of the stamp 18 on the levers 17 are set with an excellent mark shape.

The device also contains (see Fig. 4) a pulse generator 26 generating

0 two meanders of adjustable frequency with a phase shift of 180 °, arriving at biscuits 27 and 28 of a paired multi-position switch that performs the functions of switch 19. The biscuits of the biscuits are connected to

5 anodes of LEDs 3 parallel to the right and left groups on the holder 2. The cathodes of each group have a common wire and are connected to the negative pole of the pulse generator 26 through a double switch

0 12, the second pair of contacts of which switches on the power of the traction solenoids 25, shunted by the diodes 30 from the storage capacitor 29 when the button 34 is pressed, the capacitor 29, button 34 and

5, a resistor 33 forms a recording pulse generator 13.

The contacts of both biscuits 27 and 28 of the switch are parallel with a shift of one, i.e. the contact and the biscuit 27 are connected to the terminal 0 + 1 of the biscuit 28. Thanks to this connection, the flashes of the LEDs P and P + 1 alternate continuously, creating a double mark with the frequency set in the pulse generator 26.

5 straighteners 31 and 32 provide

power supply of the pulse generator 26 and the shaper 13 registration pulses

The device operates as follows. The examined eye of the patient is fixed in the center of the semi-cylindrical concave holder 2, originally set for example in a horizontal position.

Set the switch 12 to the position corresponding to the field of vision check, for example, in the left area, and the contacts of the switch biscuits 27, 28 to the position in which the LEDs 3 are periodically illuminated near the center of the holder 2. Then, the rectifiers 31 and 32 are turned on. After that, the patient gradually puts the contacts of the switch biscuits 27, 28 into a position in which the eye still detects the periodic flashing of the LEDs located on the holder 2, after which it presses the button of the registration pulse generator 13. The charge accumulated on the capacitor 29 enters the winding of the solenoid 25 located on the reading-recording device 5. The operation of the solenoid 25 leads to the movement of its core 24, causing the movement of the stamp 18.

Since the latter is kinematically connected with the handle of the LED commutator 19, this leads to the appearance of a mark on the map form of the field of vision previously placed on the tablet 4. To control the field of vision in the right area of the switch 12 is set to the opposite position, after which the operation of the device occurs similarly to the above.

To control the vision of the eye in a different plane, the position of the holder 2 is changed. After that, the control is carried out in the order described above.

Claims (2)

SUMMARY OF THE INVENTION 1. A device for measuring a field of view, comprising a base with a vertical stand, on which a horizontal axis is fixed with an arcuate plate covering the maximum field of view, and is rotatable, the horizontal axis being connected to the arcuate plate at its midpoint, and a light source markers, characterized in that, in order to reduce the examination time, two groups of LEDs are introduced into it, located on the inner side of the plate along its center line with at a constant step with alternating LEDs of each of the groups, a pulse generator, the first and second outputs of which is connected via a switch to the first outputs of the LEDs, respectively, of the first and the second group, and the second terminals of the LEDs located on each side of the arcuate plate are combined and connected to the second switch connecting them to a common wire, a recording pulse shaper, the outputs of which are connected to the inputs of the reporting and recording unit mounted on a vertical column behind the arcuate a plate. 2. The device according to claim 1, with the proviso that the reporting and recording unit comprises a tablet fixed to the horizontal axis and perpendicular to it, printing stamps that can be moved along the radius from the center of the tablet and kinematically connected to the LED switch and to the solenoids, the first outputs of the coils of which are the inputs of the unit, and the second inputs connected to a common wire. 9us.2 12 24 4/6 17 18 J6 18 i 25 /9 24 21 Figs