JPS6219147A - Fluid pulse emission controller of eye pressure measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an intraocular pressure measuring device used to measure the internal pressure of the eyeball, and in particular, to an intraocular pressure measuring device that is used to applanate the cornea with a fluid pulse. The present invention relates to a fluid pulse emission control device for a non-contact intraocular pressure measuring device.

[Prior Art] A non-contact intraocular pressure measuring device that uses fluid pulses sprays a fluid pulse onto the corneal surface from the axial direction of the device and measures the intraocular pressure based on the time taken until the cornea is applanated. However, the intraocular pressure is calculated assuming that the corneal apex is aligned with the axis of the device, so if the corneal apex is not aligned with the axis of the device, accurate intraocular pressure measurement is required. It is not possible.

Conventionally, this type of intraocular pressure measuring device projects an aiming light near the corneal surface from the axial direction of the device, and uses an observation means to observe the reflected image of the aiming light reflected along the axis. The position of the device is adjusted so that the reflected image is projected onto the axis line -1- of the device, and a beam splitter is installed on the axis line -1- in the middle of the beam splitter, and the divided reflected images are formed there. A light detection means is disposed at the image position, and the operation of the fluid pulse emitting means is controlled by an output signal from the light detection means,
The fluid pulse could only be fired when the tonometry device was in the correct position. (Japanese Patent Publication No. 5B-6772) [Problems to be Solved by the Invention] The conventional intraocular pressure measurement device described in Since the divided reflected images split by the beam splitter must be accurately projected onto the center of the light detection means, the installation position and orientation of the beam splitter must be adjusted extremely delicately, and it takes a great deal of time to assemble and adjust the beam splitter.
Moreover, since a certain degree of tolerance must be accepted for assembly and adjustment, this affects the measured intraocular pressure value, resulting in a disadvantage that the measured intraocular pressure value includes a considerable error.

An object of the present invention is to eliminate such drawbacks and provide a fluid pulse ejection control device for an intraocular pressure measuring device that can accurately measure intraocular pressure without errors and is extremely easy to assemble and adjust. shall be.

[Means for Solving the Problems] In order to achieve the above object, a fluid pulse emitting control device for an intraocular pressure measuring device according to the present invention includes a fluid pulse emitting means that ejects a fluid pulse toward the corneal surface from the axial direction of the device. , aiming light projection means for projecting aiming light near the corneal surface from the axial direction and projecting a reflected image of the aiming light reflected from the corneal surface along the axis near the axis; In the intraocular pressure measurement apparatus, a light detection means is disposed on the axis near the imaging position of the reflected image, and an output signal from the light detection means is used to emit a fluid pulse as described in 2 above. It is characterized by controlling the operation of the means.

[Operation] A reflected image of the aiming light on the corneal surface is formed near the axis of the apparatus, and can be observed by the examiner using the observation means. If the corneal apex does not match the axis of the device, the reflected image will be projected onto the peripheral area other than the light detection means arranged on the axis -L, so the position of the device should be adjusted to match the corneal apex. When the axes of the device exactly match, the reflected image is projected onto the light detection means, and the output signal from the light detection means causes the fluid pulse emitting means to emit fluid pulses.

[Example] An embodiment of the present invention will be described based on the drawings.

1 indicates the axis of the apparatus, and a fluid pulse emitting means 3 is provided for ejecting a fluid pulse from the direction of this axis 1 to two surfaces of the subject's cornea. This fluid pulse emitting means 3 comprises a solenoid 4. It is composed of a piston 5, a cylinder 6, and a nozzle 7. When the solenoid 4 is energized, the piston 5 moves within the cylinder 6, and the air inside the cylinder 6 is discharged from the nozzle 7 provided at the center of the objective lens 14. It is ejected toward two surfaces of the subject's cornea.

A light emitter 8 and a light receiver 9 are provided so as to form equal angles to the two corneal surfaces, and light emitted from the light emitter 8, reflected by the two corneal surfaces, and incident on the two light receivers 9. The amount of light reaches its maximum when the two surfaces of the cornea are applanated by the air pulse, so the intraocular pressure can be calculated from the time until the amount of light received by the light receiver 9 reaches its maximum.

IO and 11 indicate light emitting diodes that project aiming lights 10a and lla for detecting the positional relationship between the axis 1 of the apparatus and the subject's cornea 2, IO emits visible light and 11 emits infrared rays. The two beams follow the same optical path by the beam splitter 12. And this ray is transmitted to beam splitter 1
3 along the axis 1, and passes through the objective lens 14 and projects the aiming light, that is, the visible aiming light of the light emitting diode IO and the infrared aiming light of the light emitting diode 11, onto the image plane 15. When this image plane 15 is aligned with the center of curvature of the cornea 2, the reflected image of the aiming light by the two surfaces of the cornea is reflected by the objective lens 14.
The beam passes through the beam splitter 13 and is imaged onto the imaging plane 17 by the imaging lens 16, and these 10 to 16 form aiming light projection means.

Reference numeral 18 indicates a transparent screen plate disposed perpendicularly to the axis l on the image forming surface 17, and reference numeral 19 indicates an eyepiece.These constitute an observation means, and the examiner 20 uses the transparent screen plate 18
The reflected image of the aiming light projected onto the second lens can be observed through the eyepiece lens 19.

21 is the central axis 1-1- of the transparent screen plate 18;
The received light amount signal from this photoelectric element 21 is compared with the set received light amount signal value 23 in a comparator 22, and when the deviation value from the comparison is below a certain value, a trigger is activated. An actuation signal is issued from the generator 24 and input to an AND circuit 25 inserted in the power supply circuit to the solenoid 4. Then, when the switch 26 of the power supply circuit is turned on in advance, the AND circuit 25
When turned on, solenoid 4 is energized and an air pulse is emitted.

Next, the operation of this embodiment will be explained.

The subject's cornea 2 is made to substantially match the axis l of the apparatus, the subject is made to gaze at the aiming light 10a, and the image plane 15 is positioned so as to be at the center of curvature of the cornea 2 using a known adjustment device (not shown). When adjusting the aiming light, i.e. the light emitting diode 1
The visible aiming light of the light emitting diode 11 and the infrared aiming light of the light emitting diode 11 are reflected by two surfaces of the cornea, and the reflected images are displayed on the transparent screen plate 18.
1, and the reflected image of the visible aiming light is observed by the examiner 20 through the eyepiece 19. If the vertex of the cornea 2 does not coincide with the axis l, the reflected image will be projected onto the peripheral part of the transparent screen plate 18 other than the center (i.e., the photoelectric element 21 part), so □further operate the adjustment device. Then, the reflected image on the transparent screen plate 18 is brought close to the photoelectric element 21.

When the two vertices of the cornea and the axis l exactly coincide, the reflected image of the aiming light is projected onto the photoelectric element 21 at the center of the transparent screen plate 18, and the photoelectric element 21 outputs a large received light amount signal, which is output from the trigger generator 24. The trigger signal is input to the AND circuit 25, and the AND circuit 25 is turned on and the solenoid 4
is energized, and air pulses are automatically emitted toward the two corneal surfaces.

In addition, in the second embodiment, a diode that emits visible light and a diode that emits infrared light were used together, but the diode is not limited to this, and only one of them could be used. Alternatively, a light emitting body other than a diode may be used. Furthermore, the air pulse is automatically emitted when the two corneal vertices coincide with the axis l, but when the trigger signal from the trigger generator 24 is input to the AND circuit 25, the switch 26
Air pulses may be fired by manually turning on the air pulse.

[Effects of the Invention] According to the fluid pulse emission control device of the intraocular pressure measuring device of the present invention, the light detection means is provided on the axis of the device, and when the reflected image of the aiming light by the corneal surface is projected on the axis, the fluid Since the pulse emitting means is activated, it is not affected by the installation error of the beam splitter as in the conventional case, and it is possible to see an accurate eye without any errors when the corneal apex and the axis of the device are perfectly aligned. Pressure can be measured, and the device is extremely easy to assemble and adjust.

[Brief explanation of the drawing]

The drawing is a block diagram of an embodiment of the fluid pulse emission control device of the intraocular pressure measuring device of the present invention. l...Axis 2...Cornea 3...Fluid pulse emitting means 4...Solenoid 5...Piston 6...
Cylinder 7... Nozzle 10.11... Light emitting diode 10a, 11a = Aiming light 12.13... Beam splitter 14... Objective lens 15... Image plane 16...
- Imaging lens 17... Image forming surface 18... Transparent screen plate 19... Eyepiece lens 21... Photoelectric element 22... Comparator 23... Set received light amount signal value

Claims (1)

[Scope of Claims] 1. Fluid pulse emitting means for emitting a fluid pulse toward the corneal surface from the axial direction of the device, and aiming light projected near the corneal surface from the axial direction and reflected along the corneal surface by the corneal surface. In the intraocular pressure measuring device, the intraocular pressure measuring device includes an aiming light projection means for projecting a reflected image of the aimed aiming light near the axis, and an observation means for observing the reflected image, on the axis near the imaging position of the reflected image. 1. A fluid pulse emission control device for an intraocular pressure measuring device, characterized in that a light detection means is disposed in the light detection means, and the operation of the fluid pulse emission means is controlled by an output signal from the light detection means. 2. The intraocular pressure measuring device according to claim 1, wherein the aiming light includes visible aiming light formed by visible light and infrared aiming light formed by infrared rays and operating the light detection means. Fluid pulse firing control device. 3. Control of the operation of the fluid pulse emitting means is to automatically emit fluid pulses, Claim 1
A fluid pulse emission control device for the intraocular pressure measuring device according to item 1 or 2.