JPH06178762A - Perimetric device provided with pupil diameter measuring function - Google Patents

Abstract

PURPOSE:To accurately measure the pupil diameter of a subject by providing both a light-receiving means for receiving the measuring luminous flux reflected by the pupil part of an eye to be examined, and an arithmetic processing means for calculating the diameter of the pupil of the eye to be examined on the basis of the measuring signal from the light-receiving means. CONSTITUTION:An image pickup means 12 receives the measuring luminous flux reflected by the pupil part of the eye to be examined and coverts it into a measuring signal. The low-luminance part detecting means 41 of an arithmetic processing means 4 detects the part where the measuring signal of the image pickup means 12 becomes a low level, and a scanning line selective means 42 selects the scanning line in which the scanning time becomes maximum, and measures the scanning time. Further, on the basis of the scanning time of the scanning line selected by the scanning line selective means 42, the calculating part 43 calculates the diameter of a pupil by means of a prescribed calculation formula. A CPU 9 controls a target projection control part 2 for driving a light source 23 for index projection use, and also controls a rotary mirror driving motor 21 for target photographing use for determining the position of the target. Further, the CPU drives a target focusing motor 22 for regulating the focus so that the luminance and the size of the target cannot be changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual field measuring device,
In particular, the present invention relates to a visual field measuring device having a pupil diameter measuring function capable of automatically measuring the value of the pupil diameter by selecting the scanning line having the longest scanning time among the scanning lines of the imaged video signal. is there.

[0002]

2. Description of the Related Art Measuring a visual field of an eye to be examined is an effective means for diagnosing diseases of the eye such as glaucoma. In order to perform this visual field measurement accurately, it is necessary to measure and record the pupil diameter of the subject's eye. This is because when the pupil diameter changes due to the use of a drug or the like, the visual field contour line changes, and there is a risk that the visual field may be mistaken for improvement or deterioration.

Therefore, the diameter of the pupil of the subject has been conventionally measured, and as shown in FIG. 6A, the examiner uses a scale 810 formed on the lens 800 using a telescope. Then, the pupil 1000 of the eye of the subject was directly measured.

Further, as shown in FIG. 6B, a CCD camera or the like is used to capture an image of the eye of the subject, and this image pickup signal is displayed on the monitor 900, and the examiner is formed on the monitor 900. Using the scale 910, the pupil 10 of the eye of the subject is measured.
00 was measured indirectly.

[0005]

However, in the conventional method of measuring the pupil diameter, the examiner uses the scale 810 of the lens 800.
Is read or the scale 910 of the monitor 900 is read, a reading error by an examiner cannot be avoided, and further,
There is a problem that the pupil diameter of the subject cannot be accurately measured because the scale itself formed also has an error.

[0006]

Means for Solving the Problems The present invention configured as described above provides an index presenting means, a visual field measuring surface on which an index is presented by the index presenting means, and an eye position of an examinee. In a visual field measurement device having an eye placement guide portion for relatively fixing substantially at a predetermined position with respect to the measurement surface, a light receiving means for receiving the measurement light beam reflected by the eye pupil portion of the eye, It is composed of an arithmetic processing means for calculating the value of the pupil diameter of the eye to be inspected by the measurement signal from the light receiving means.

Further, the arithmetic processing means includes a low-luminance portion detecting means for detecting a portion where the measurement signal has a low level, and a low-luminance portion detected by the low-luminance portion detecting means. The scanning line selecting means for selecting the scanning line having the largest value, and the calculating section for calculating the value of the pupil diameter based on the scanning time of the scanning line selected by the scanning line selecting means. You can also

Further, the arithmetic processing means may be connected with an output means for outputting the value of the pupil diameter and a display means for displaying an observation image of the eye to be examined measured by the light receiving means.

[0009]

According to the present invention configured as described above, the index presenting means presents an index on the visual field measurement surface, and the subject eye placement guide portion positions the subject's eye position on the visual field measurement surface. It is relatively fixed at a predetermined position, the light receiving means receives the measurement light beam reflected by the pupil part of the eye to be inspected, and the arithmetic processing means calculates the value of the pupil diameter of the eye to be inspected from the measurement signal from the light receiving means. It is supposed to do.

Further, in the arithmetic processing means, the low-luminance portion detecting means detects a portion where the measurement signal becomes low level, and the scanning line selecting means is the low-luminance portion detected by the low-luminance portion detecting means, Select the scan line that maximizes the scan time,
The calculator may calculate the value of the pupil diameter based on the scanning time of the scanning line selected by the scanning line selecting means.

The output means connected to the arithmetic processing means outputs the value of the pupil diameter, and the display means connected to the arithmetic processing means displays the observation image of the eye to be measured measured by the light receiving means. You can also do it.

[0012]

[Measurement principle]

The measurement signal from the light receiving means causes the eye A to be inspected.
The principle of calculating the pupil diameter for calculating the value of the pupil diameter will be described in detail.

For example, when the light receiving means is an image pickup means composed of a CCD or the like, when this image pickup signal is output to a monitor or the like, the horizontal scanning frequency of the monitor is f (Hz), and one horizontal scanning is performed. If the required time is T (sec),

T = 1 / f (sec) ..... Formula 1

[0016]

Here, when the horizontal length of the area displayed on the monitor is X (mm), the scanning time t _min (s of the displayed image per 1 mm in the displayed object is t _min (s).
ec / mm) is

T _min = T / X (sec / mm) ··· Second formula

As shown in FIG. 5, the video signal in the white portion of the display object has a high level and the video signal in the black portion has a low level. The pupil diameter can be measured by utilizing the level difference between the video signals. That is, the pupil 1000
It is a black part corresponding to (3) and measures the time during which the video signal is at a low level.

Specifically, the time during which the pupil portion is scanned is measured for each scanning line, and the scanning line having the longest scanning time, that is, the scanning line obtained by scanning the diameter portion of the pupil 1000 is selected. Then, if the scanning time at that time is Tx, the pupil diameter L (mm) can be obtained as follows using this scanning time Tx and the scanning time t _min per 1 mm.

L = (1 / t _min ) Tx = Tx / t _min (mm) (3rd expression)

[0022]

【Example】

An embodiment of the present invention will be described with reference to the drawings.

An embodiment of the present invention will be described with reference to the drawings. 1 and 2 are views for explaining the mechanical configuration of the visual field measuring device 1. The visual field measuring device 1 has a housing 11
0, the housing 110 is provided with a substantially hemispherical dome 120, and the inner surface of the dome 120 serves as a projection screen 130. Projection screen 1
Reference numeral 30 corresponds to a visual field measuring surface. Dome 12
0 is provided with a panel 140 on the front surface thereof.
A face receiving hole 150 is formed in the face receiving hole 150, and the face receiving member 16 for fixing the face is provided in the face receiving hole 150.
0 is provided. The face receiving member 160 has a forehead support member 161 and a jaw receiving member 162 attached thereto. The eye to be measured is the spherical center O of the projection screen 130.
It is located near the center of the sphere, including.

The face receiving member 160 for fixing the face portion is constructed to be movable left and right so that either the left eye or the right eye can be measured. In this embodiment, the face receiving member 160 and the handle are connected by an appropriate driving means,
When the handle is rotated, the forehead support member 161 and the chin rest member 162 are configured to move left and right in conjunction with each other. Therefore, when measuring the left eye of the measurement subject, the handle is rotated and the forehead support member 161 and the chin rest member 1 are rotated.
When 62 and 62 are moved to the right side, and then the right eye of the person to be measured is measured, the handle may be rotated to move both the forehead support member 161 and the chin rest member 162 to the left side. . Further, as shown in FIG. 3, in the present embodiment, the measuring eye detecting means 11 for detecting whether the face receiving member 160 is on the right side or the left side is formed. The measuring eye detecting means 11 is composed of an appropriate electric switch means.

The face receiving member 160 for fixing the face portion is
It corresponds to the eye placement guide portion.

As shown in FIG. 2, the housing 110 is provided with a projection optical system 300 on the back side of the dome 120. The projection optical system 300 includes an illumination light source 310, a condenser lens 320, and an index. 330 and collimator lens 3
40, a projection lens 350, and reflection mirrors 360 and 36
It is composed of 0 and 0. Here, the illumination light source 310, the condenser lens 320, the visual target 330, and the collimator lens 340.
And constitute a first optical system for emitting the target light as a parallel light flux. Projection lens 350 and reflection mirror 36
0 is the second for guiding the parallel projection light beam together with the rotating mirror 400, which will be described later, to guide the target projection light to the target presentation portion I of the projection screen 130 through the vicinity of the center of the ball except the center O. It constitutes an optical system, and the dome 120 is provided with a guide hole 121. The target projection light reflected by the reflection mirror 360 is guided to the rotary mirror 400 through the guide hole 121.

The rotating mirror 400 is provided in the vicinity of the sphere center except the sphere center O, and when the rotating mirror 400 is rotated, the target point I to be displayed is changed.

Next, the electrical construction of the visual field measuring apparatus 1 of this embodiment will be described with reference to FIG. This visual field measuring device 1
The electrical configuration of the field of view projection control unit 2 and the response switch 3
An arithmetic processing unit 4 for calculating the value of the pupil diameter, an optotype projection program storage unit 5, a temporary storage unit 6, an operation unit 7, a display unit 8, a CPU 9, and an external data input unit 10.
And a measuring eye detecting means 11 and an imaging means 12.

The visual field projection control unit 2 controls the optotype projection mirror drive motor 21, the visual field focusing drive motor 22 and the index projection light source 23, and corresponds to optotype presenting means. Is. The target-projection rotary mirror drive motor 21 drives the rotary mirror 400, and by rotating the rotary mirror 400, the target present portion I is displayed.
Can be changed.

The drive motor 22 for focusing the visual target is the imaging lens 3
The distance L ₁ from the rotation center of the rotating mirror 400 to the optotype presenting position I can be changed. That is, when the rotary mirror drive motor 21 for photographing the target is driven to rotate the rotary mirror 400, the distance L ₁ from the rotation center of the rotary mirror 400 to the target position I is changed. In order to correct this change in the distance L ₁ , it is necessary to drive the optotype focusing drive motor 22 and move the imaging lens 350 in the optical axis direction. As a result,
It is possible to display on the projection screen 130 an image of a target whose size and brightness hardly change regardless of the change of the target display position I.

The optotype projection light source 23 controls the lighting of the illumination light source 310. Not only can it be switched on and off, but also the brightness (intensity) of the light source can be changed by adjusting the light source voltage. it can. And the illumination light source 310
The brightness of the target on the projection screen 130 can be changed by adjusting the intensity of the.

The response switch 3 corresponds to response detection means, and inputs whether or not the person to be measured recognizes the visual target. The response switch 3 is preferably operated by the person to be measured, but when the person to be measured is a child or an elderly person, the measurer receives the recognition from the person to be measured and is operated by the person to be measured. Good.

The arithmetic processing means 4 is for calculating the value of the pupil diameter of the subject, and is the low luminance part detecting means 41.
And a scanning line selecting unit 42 and a calculating unit 43.

The low-luminance part detecting means 41 is used as the image pickup means 12.
This is for detecting the part where the measurement signal of is low level. The scanning line selection means 42 is the low luminance part detection means 4
This is for selecting the scanning line that has the longest scanning time in the low-intensity portion detected in 1. Calculation unit 4
Reference numeral 3 is for calculating the value of the pupil diameter based on the scanning time of the scanning line selected by the scanning line selecting means 42.

As shown in FIG. 4, the image pickup means 12 is arranged so as to face the eye of the subject.

The image pickup means 12 corresponds to a light receiving means, and is for receiving the measurement light beam reflected by the pupil part of the eye to be examined and converting it into a measurement signal. In this embodiment, CC
Although the D camera is used, any one can be adopted as long as it is a light receiving means capable of obtaining an image signal.

The optotype projection program storage unit 5 stores a program for determining optotype presenting conditions for visual field measurement. The optotype brightness, index position, lighting time, and the like are set to desired values. Can be controlled. For example, a screening measurement program, a meridional program, a glaucoma program, or the like can be adopted as this target projection program.

The temporary storage unit 6 corresponds to a temporary storage means and stores the presence or absence of the recognition of the visual target of the person to be measured, and in the present embodiment, the random access memory (RA).
M) is adopted. That is, for the presented optotype,
This is for storing whether or not the response switch 3 has been activated. The temporary storage unit 6 also stores the level of the optotype when the optotype of the measurement subject is recognized, and the measurement eye detecting means 1
Based on the detection signal No. 1, the right eye response data and the left eye response data are identified and stored. That is RA
Of the M storage areas, an area for storing the right-eye response data and an area for storing the left-eye response data are defined in advance, and the storage areas are switched based on the detection signal of the measurement eye detecting means 11. It is configured like.

The operation section 7 is for operating the entire visual field measuring apparatus 1, and is composed of various control switches and a light pen. The display unit 8 is composed of a TV monitor or the like, and can display the type and index distribution of the optotypes projected on the photographing screen 130, commands input from the control switch, and the like, and further, in the present embodiment. The display unit 8 corresponds to a display unit and can also display an image captured by the image capturing unit 12.

The CPU 9 controls various arithmetic operations of the visual field measuring apparatus 1. The arithmetic processing means 4 etc.
It is configured to perform a calculation together with the function of U.

The external data input means 10 is for inputting inspection data other than visual field measurement data. The external data input means 10 may be a reading means such as an electronic medical chart composed of an IC card or a magnetic card, and is a means such as a keyboard, a mouse or a light pen, which is manually input by a measurer. May be. Further, the external data input means 10 may be an interface for directly connecting to the tonometer. The examination data other than the visual field measurement data corresponds to, for example, data such as intraocular pressure, fundus finding, and medical history.

The floppy disk drive 12 corresponds to a storage means, and is for storing the right eye response data and the left eye response data stored in the temporary storage section 6 in the floppy disk. The storage means is not limited to the floppy disk drive, but a hard disk, an optical disk, or the like can be adopted.

The printer 13 is for printing out the measurement result based on the right-eye response data and the left-eye response data stored in the temporary storage section 6. CPU9
Since the right-eye response data and the left-eye response data are separately stored, the printer 13 can output the left-eye and right-eye visual field measurement data in a predetermined order. Further, the printer 13 of this embodiment corresponds to an output means and can output the value of the measured pupil diameter.

Next, the operation of this embodiment will be described.

First, at the start of measurement, the handle is rotated to adjust the distance between the forehead support member 161 and the chin rest member 162. Next, the face receiving member 160 detects whether it is on the right side or the left side, and the measurement eye detecting means 11 transmits a detection signal to the CPU.

When the CPU 9 activates the image pickup means 12, the image pickup means 12 receives the measurement light beam reflected by the pupil part of the eye to be examined and converts it into a measurement signal.

Further, the low-brightness portion detecting means 41 of the arithmetic processing means 4 detects the portion where the measurement signal of the image pickup means 12 becomes low level, and the scanning line selecting means 42 selects the scanning line having the longest scanning time. Then, the scanning time Tx is measured. Further, the calculation unit 43 uses the scanning line selection unit 42.
Based on the scanning time Tx of the scanning line selected by
The value of the pupil diameter can be calculated by calculating the formula.

Next, when a measurement start command is input from the operation unit 7, the CPU 9 reads the control program from the visual field projection program storage unit 5 and executes it. Further, the CPU 9 controls the target projection control unit 2 according to the control program to drive the index projection light source 23. Furthermore, the position of the target is determined by controlling the rotary mirror driving motor 21 for capturing the target and rotating the rotary mirror 400. Further, the CPU 9 drives the optotype focusing motor 22 according to the rotation of the rotary mirror 400, and adjusts the optotype so that the brightness and size of the optotype do not change.

When the subject recognizes the presented optotype, the subject activates the response switch 3. When the person to be measured determines whether or not the response switch 3 is activated and the person to be measured does not recognize the target and does not activate the response switch 3, the target projection control unit 2 is controlled to present the presentation level. Up.

Next, when the person to be measured recognizes the visual target and activates the response switch 3, the response of the person to be measured and the level at the time of the response are stored in the temporary storage section 6. The right-eye response data and the left-eye response data are stored in separate storage areas of the temporary storage unit 6 based on the detection signal of the measurement eye detection means 11.

Then, it is determined whether or not all the measurement points have been measured, and if all the points are not finished, the optotypes are moved to the unfinished points and the optotypes are presented.

In the present embodiment configured as described above, the measured value of the pupil diameter can be output to the printer 13 and the image picked up by the image pickup means 12 can be displayed on the display section 8.

[0054]

[Effect] According to the present invention configured as described above, the index presenting means, the visual field measuring surface on which the index is presented by the index presenting means, and the position of the eye to be examined of the subject are predetermined with respect to the visual field measuring surface. In the visual field measuring device having an eye placement guide part for substantially fixed to the position of, the light receiving means for receiving the measurement light beam reflected by the pupil part of the eye and the measurement from this light receiving means. The signal is composed of an arithmetic processing means for calculating the value of the pupil diameter of the eye to be inspected, so that the value of the pupil diameter of the eye to be inspected can be automatically measured, and the reading error by the examiner is small. It has the outstanding effect of disappearing.

[0055]

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an index presenting unit of the present embodiment.

FIG. 3 is a perspective view illustrating the electrical configuration of the present embodiment.

FIG. 4 is a diagram illustrating an image pickup unit 12 of the present embodiment.

FIG. 5 is a diagram illustrating the principle of the present invention.

FIG. 6 is a diagram illustrating a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Field-of-view measuring device 2 Field-of-view projection control unit 3 Response switch 4 Calculation processing unit 41 Low-intensity part detection unit 42 Scanning line selection unit 43 Calculation unit 45 Irradiation optical system 5 Visual target projection program storage unit 6 Temporary storage unit 7 Operation unit 8 Display Part 9 CPU 10 External data input means 11 Measuring eye detecting means 12 Imaging means 12 130 Projection screen 160 Face receiving member 161 Forehead resting member 162 Jaw receiving member

Claims (3)

[Claims] 1. An index presenting means, a visual field measuring surface on which an index is presented by the index presenting means, and an eye position of a subject are fixed substantially at a predetermined position relative to the visual field measuring surface. In the visual field measuring device having an eye placement guide portion for the light receiving means for receiving the measurement light beam reflected by the pupil portion of the eye to be inspected, and the measurement signal from the light receiving means, the pupil diameter of the eye to be inspected A visual field measuring device having a pupil diameter measuring function, which comprises an arithmetic processing unit for calculating a value. 2. The index presenting means, the visual field measuring surface on which the index is presented by the index presenting means, and the position of the subject's eye to be inspected are relatively fixed to a predetermined position relative to the visual field measuring surface. In the visual field measuring device having an eye placement guide portion for the light receiving means for receiving the measurement light beam reflected by the pupil portion of the eye to be inspected, and the measurement signal from the light receiving means, the pupil diameter of the eye to be inspected And a low-luminance portion detecting means for detecting a portion where the measurement signal has a low level, and the low-luminance portion detecting means for detecting the value. In the low-luminance portion, the value of the pupil diameter is calculated based on the scanning line selecting means for selecting the scanning line having the longest scanning time and the scanning time of the scanning line selected by the scanning line selecting means. From the calculation unit to A visual field measuring device having a pupil diameter measuring function characterized by being configured. 3. The arithmetic processing means is connected to an output means for outputting the value of the pupil diameter and a display means for displaying an observation image of the eye to be examined measured by the light receiving means. A visual field measuring device having a pupil diameter measuring function according to 1 or 2.