JPH0638930A - Load-detection type tonometer - Google Patents

Abstract

PURPOSE:To provide a lead-detection type tonometer wherein the structure thereof is simple and can be downsized and intraocular pressure can be accurately measured. CONSTITUTION:A slide bed 3, on which a load sensor 1 is mounted, is provided so as to be moved on a surface plate 4 slidably in front and rear directions and when a lever 6 is pulled by an operator, the slide bed 3 is moved forward by the tensile force of a spring 5, and thus an eye 9 to be examined is indirectly pushed through the surface of an eyelid 10, by a pressure-applying rod 2 joned to the load sensor 1. The load thereof is detected by the load sensor 1 and in a signal-processing circuit, intraocular pressure is found on the basis of the load ratio between changes with the passage of time. The structure thereof is made extremely simple compared with a usual structure wherein the eye 9 is pushed through the drive of a motor, and can be downsized, and the intraocular pressure can accurately be measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tonometer for measuring intraocular pressure, and more particularly to a load detection type tonometer for indirectly pressurizing an eye to be examined from above the eyelid and detecting the load to measure the intraocular pressure. It is a thing.

[0002]

2. Description of the Related Art At present, there are two types of tonometers that are mainly used. A contact applanation tonometer and a non-contact tonometer. The contact applanation tonometer has a problem in that the inspection member needs to be brought into direct contact with the cornea of the eye to be inspected, so that the cornea is scratched or transmitted from the inspection member. Although the non-contact tonometer has improved those problems, in principle, it is necessary to blow an air jet to the cornea, so that there is a problem that the patient feels uncomfortable.

Based on these circumstances, a load detection type tonometer has been devised in which the eye to be inspected is indirectly pressurized from above the eyelid and the load is detected by a sensor to measure the intraocular pressure. This method aims to measure the intraocular pressure objectively and quantitatively using the principle of the intraocular pressure test by palpation.

[0004]

However, the conventional load detection type tonometer has the following problems.

1) A motor was used as a driving means for pressurizing the eyeball, but this was not practical because it would make the device bulky.

2) When the eyeball is indirectly pressurized by using a pressure rod, there is a phenomenon that the entire eyeball moves to the back even though it is desired to generate only the displacement of the surface of the eyeball. for that reason,
The load amount detected by the load sensor is not only related to the displacement of the eyeball surface, but also the component due to the movement of the entire eyeball is added.

3) The greatest advantage of the load detection type tonometer is that the eye pressure of the subject's eye is closed. However, in general, the cornea in the closed eye state exists at a position completely different from that in the open eye state, and therefore it is difficult to press the cornea over the eyelid in the closed eye state.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve these problems and provide a practical load detection type tonometer which can accurately measure the intraocular pressure and can be downsized.

[0009]

In order to solve the above problems, according to the present invention, a load sensor connected to a pressure rod is moved toward the eye to be inspected, and the pressure rod closes the eye to be inspected. In the load detection type tonometer which pressurizes from above the eyelid, detects the load by the load sensor and measures the intraocular pressure of the eye to be inspected from the ratio of the change of the load with time, the load sensor goes to the eye to be inspected. A structure is adopted in which all movement is performed by an elastic body.

[0010]

With such a structure, the structure is extremely simple as compared with the conventional method of driving the motor to pressurize the eye to be inspected, and the tonometer as a whole can be miniaturized.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. First, the structure of the load-type tonometer of the embodiment will be described with reference to FIG.

In the tonometer of the present embodiment shown in FIG. 1, the slide bed 3 having the load sensor 1 mounted thereon is placed on the surface plate 4 in the anteroposterior direction along the eye axis of the eye 9 to be measured (left and right in the figure). Direction) and is biased forward by a spring 5. A trigger 6 operated by an examiner is provided at the rear end of the surface plate 4 in the figure so as to be rotatable around a shaft 6a as a fulcrum, and a lower end of the trigger 6 is detachably attached to the slide bed 3. To meet.

Further, a shaft 1a on which a load to be detected is applied protrudes from the front side of the load sensor 1, and a pressure rod 2 for indirectly pressurizing the eye 9 to be inspected from above the eyelid 10 is fixed to the tip thereof. Has been done. A cylinder 7 is provided in front of the surface plate 4 so as to be movable in the front-rear direction, and is urged forward by a spring 8. The diameter of the cylinder 7 corresponds to the diameter of the eye 9 to be inspected. The pressure bar 2 is arranged in the cylinder 7 along the center line of the cylinder 7.

Next, FIG. 2 shows the configuration of an electric circuit for obtaining the intraocular pressure from the output signal of the load sensor 1. Figure 2
In the figure, 11 is an A / D converter for A / D converting the output of the load sensor 1. Reference numeral 12 is a signal processing circuit including a microprocessor or the like, which processes the weight data signal output from the A / D converter 11 and performs arithmetic processing for obtaining an intraocular pressure value as described later. Further, 13 is a memory used for storing load data, and 14 is a display for displaying the intraocular pressure value of the measurement result.

Next, the intraocular pressure measuring operation of this embodiment will be described with reference to FIG.

FIG. 3 shows a state at the time of measurement as seen from above the subject's head. In FIG. 3, 15 is the other eye which is not the subject's eye, and 16 is the nose. Further, in the tonometer of this embodiment, a fixation lamp 17 is provided behind the load sensor 1. Before performing the measurement, the slide bed 3 is locked by the trigger 6 and is in the position shown in FIG.

As shown in FIG. 3, at the time of measurement, the subject has the subject's eye 9 closed and the other eye 15 opened. Next, the cylinder 7 is applied to the peripheral portion of the eyeball from above the eyelid of the eye 9 to be inspected, and is pressed with a constant strength by the elastic force of the spring 8 to fix the eyeball in the front-back direction. Then, the fixation lamp 17 is turned on so that the other eye 15 can see the fixation lamp 17. That is, the front is fixed and the position of the cornea 15a of the eye 15 is fixed to the front. As a result, the position of the cornea 9a of the eye 9 to be inspected that is interlocked with the eye 15 is also fixed in front of the fixation lamp 17 and faces the pressure rod 2.

Here, when the operator pulls the trigger 6, the lock of the slide bed 3 is released, and the slide bed 3 is released.
Is slid forward by pulling the spring 5, the pressurizing rod 2 pressurizes the eyeball of the eye 9 to be inspected from above the eyelid, and the load thereof is detected by the load sensor 1.

The output signal of the load sensor 1 is A / D converted as load data by the A / D converter 11 of FIG. 2, input to the signal processing circuit 12, and written in the memory 13.
After that, the signal processing circuit 12 reads the load data from the memory 13, obtains the ratio of load change / time as shown in the flowchart of FIG. 4 (step S1), and further based on the correlation between the weight change / time and the intraocular pressure. The load change / time is converted into intraocular pressure (step S2). That is, generally, the hardness of the eyeball is measured by the load amount with respect to the pushing amount of the pressure rod 2, but since the pressure rod 2 is moving here, the hardness of the eyeball is measured based on the load change with time. Quantify that. Here, the relationship between load and time is shown in FIG. Since the apparent hardness of the eyeball is determined by the intraocular pressure, the intraocular pressure can be converted from the ratio of load change / time, that is, the inclination. That is, according to the result of the comparison experiment using the load-type tonometer, as shown in FIG. 6, it has been found that the load change / time and the intraocular pressure have a direct proportional correlation, and based on this correlation, the load Change / time can be converted into intraocular pressure.

In this way, the signal processing circuit 12 obtains the intraocular pressure value and then displays the intraocular pressure value on the display 14 (step S3).

The signal processing circuit 12 obtains the intraocular pressure value, and then the eye 9 to be inspected with respect to the pressure bar 2 generated at the time of measuring the intraocular pressure.
The intraocular pressure value shall be corrected so as to eliminate the influence on the intraocular pressure measurement due to the position variation, the subject's body temperature, and the measurement environment.

According to the present embodiment as described above, the movement of the slide bed 3, that is, the movement of the load sensor 1 is performed by the spring, so that the structure is extremely superior to the conventional structure using a motor as a drive source for pressurization. It becomes easier and the tonometer as a whole can be made smaller. Further, by pressing the cylinder 7 to fix the eyeball in the front-back direction before pressurizing the eyeball of the eye 9 with the pressure rod 2, a component due to the movement of the entire eyeball from the load amount detected by the load sensor 1 is detected. It can be removed and the intraocular pressure can be measured more accurately. Further, by fixing the fixation lamp 17 to the other eye 15, the cornea 9a of the eye 9 to be inspected can be directed forward regardless of the closed eye state. From this point as well, the intraocular pressure can be measured more accurately. be able to.

[0023]

As is apparent from the above description, according to the present invention, the load sensor connected to the pressure rod is moved toward the eye to be inspected, and the pressure rod causes the eyelid to be closed. In a load detection tonometer that pressurizes from above and detects the load by the load sensor and measures the intraocular pressure of the eye from the ratio of the change over time of the load, the load sensor moves toward the eye Since an elastic body is adopted, the whole tonometer can be downsized with a much simpler structure than the conventional one, and the excellent effect that the tonometry can be accurately performed is obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structure of a load detection type tonometer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an electric circuit for obtaining an intraocular pressure from an output signal of a load sensor in the same tonometer.

FIG. 3 is an explanatory diagram showing a state at the time of measuring the intraocular pressure as seen from above the head of the subject.

FIG. 4 is a flowchart of processing of a signal processing circuit for obtaining intraocular pressure.

FIG. 5 is a diagram showing a relationship between a load of a pressure rod and time when measuring intraocular pressure.

FIG. 6 is a diagram showing a correlation between load change / time and intraocular pressure according to experimental results.

[Explanation of symbols]

 1 Load Sensor 2 Pressurizing Rod 3 Slide Bed 4 Surface Plate 5, 8 Spring 6 Trigger 7 Cylinder 9 Eye 9 A / D Converter 12 Signal Processing Circuit 13 Memory 14 Indicator 15 Other Eye 17 Fixing Light

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 29, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art As a conventional intraocular pressure measuring method, a contact type is used.
A thing and a non-contact type thing are known. Contact type device
The measurement part of is brought into direct contact with the eyeball to obtain a certain amount of deformation.
The intraocular pressure is obtained from the pressing force required for. On the other hand, non
The contact type sprays air on the surface of the cornea and mainly
Many methods measure the deformation of the cornea.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

However, the contact type is currently used.
Currently, it is highly reliable, but part of the device is directly attached to the cornea.
The cornea is touched, so if the examiner is not familiar with the operation,
The problem is that there is a risk of damage.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

On the other hand, in the non-contact method, the above-mentioned corneal damage
Although the risk is reduced, air is sprayed on the cornea,
There is a problem of giving the examiner discomfort and fear. One
The machine doesn't touch the cornea directly
The point above is that the stress is applied directly to the cornea during measurement.
There is no difference from the contact type.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Therefore, an object of the present invention is to solve the above problems.
Safe, easy to operate and uncomfortable for the subject
It can be configured easily and inexpensively without giving a feeling of feeling or fear.
To provide a tonometer.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Delete

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Delete

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Delete

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

In order to solve the above problems, according to the present invention, the eye to be inspected is placed on the eyelid of the eye to be inspected.
The pressure bar to be pressed and the drive that generates the pressing force of the pressure bar.
Moving means and a load for detecting the load applied to the pressure rod
The sensor and the load when the pressure bar presses the eye to be examined.
The intraocular pressure of the eye to be inspected based on the load detected by the heavy sensor
Provided is a load detection type tonometer provided with a calculating means for obtaining the load.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

With this structure , the driving means drives the driving means.
The pressure rod presses the eye to be inspected from above the eyelid,
The load applied to the pressurizing rod is detected by the load sensor.
The intraocular pressure is calculated by the calculation means based on the detection result of
It

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

According to the present embodiment as described above, the subject
May be examined with the eyelids of the eye examined closed
Therefore, for the cornea of the eye to be examined, any of the conventional
Unlike the method, it can perform a completely non-contact inspection. Well
Since pressing is done from the top of the lid, it looks like the conventional contact method.
There is no risk of damaging the cornea, and operation of the device is extremely easy.
It will be easier. In addition, as in the conventional non-contact method,
Since no contact air is sprayed, the subject feels uncomfortable,
There is no fear. Further, according to the present embodiment, since the movement of the slide bed 3, that is, the movement of the load sensor 1 is performed by the spring, the structure is extremely simple and the tonometer as a whole can be downsized. Further, by pressing the cylinder 7 to fix the eyeball in the front-back direction before pressurizing the eyeball of the eye 9 with the pressure rod 2, a component due to the movement of the entire eyeball from the load amount detected by the load sensor 1 is detected. It can be removed and the intraocular pressure can be measured more accurately. Further, by fixing the fixation lamp 17 to the other eye 15, the cornea 9a of the eye 9 to be inspected can be directed forward regardless of the closed state, and from this point as well, the intraocular pressure can be measured more accurately. be able to.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

As is apparent from the above description, according to the present invention, it is possible to press the eye to be inspected from above the eyelid of the eye to be inspected.
A pressure rod, drive means for generating a pressing force of the pressure rod,
A load sensor for detecting the load applied to the pressure rod,
When the pressure bar presses the eye to be examined, the load sensor
Calculation to calculate the intraocular pressure of the eye based on the detected load
Since the structure of the load detection type tonometer provided with the means is adopted,
Measurement of eye pressure by pressing the eye to be inspected with the eyes closed from above the eyelids
Damage to the cornea of the subject's eye as before.
There is no danger, it is easy to operate, and the subject feels discomfort and fear.
It does not give a feeling. Further, the tonometer as a whole can be downsized with a simple structure, and an excellent effect that the tonometry can be accurately performed can be obtained.

Claims (4)

[Claims] 1. A load sensor connected to a pressure bar is moved toward the eye to be inspected, and the pressure bar presses the eye to be inspected in a closed state from above the eyelid, and the load sensor detects the load. In a load detection type tonometer for measuring the intraocular pressure of the eye to be examined from the rate of change of the load with time, a load detection type tonometer characterized in that the load sensor is moved toward the subject eye by an elastic body. . 2. The load detection type tonometer according to claim 1, further comprising a cylinder for pressing the peripheral edge of the eye to be examined from above the eyelid to fix the eye to be examined in the front-back direction. 3. The load detection type eye according to claim 1, wherein a fixation lamp for fixing the front side to the other eye of the subject, which is not the subject's eye, is provided at the time of measuring the intraocular pressure. Pressure gauge. 4. An electric circuit is provided, which eliminates the influence on the intraocular pressure measurement due to the positional fluctuation of the eye to be examined with respect to the pressurizing rod generated during intraocular pressure measurement, the body temperature of the subject, and the measurement environment. The load detection tonometer according to any one of claims 1 to 3.