JPH1119037A - Ophthalmic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ophthalmic device which performs an automatic alignment adjustment and an ocular tension automatic measurement based on an XY directional level value and a Z directional level value of a reflective light from an eye to be inspected. SOLUTION: This ophthalmic device having a function to automatically align the device main body (device optical system) regarding the XY direction and Z direction, to a specified reference location (alignment base point) of a cornea C of an eye E to be inspected, performs an automatic alignment adjustment while moving the device main body in such a manner that the alignment location may meet the alighment base point. When an XY directional level value becomes larger than a Z directional level value, the automatic alignment adjustment is completed, and an ocular tension measurement is performed. On the other hand, when the XY directional level value becomes smaller than the Z directional level value, the automatic alignment adjustment and the ocular tension measurement are stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a positional relationship between an apparatus main body (apparatus optical system) of an ophthalmic apparatus such as a non-contact type tonometry apparatus (tonometer) and an eye to be examined, and detects the positional relationship. The present invention relates to an ophthalmologic apparatus having an automatic alignment function capable of automatically aligning an apparatus main body at a predetermined position of an eye to be examined by moving the apparatus main body based on a result.

[0002]

2. Description of the Related Art Conventionally, an ophthalmologic apparatus having a so-called automatic alignment function, that is, a cornea reflected light of an alignment index light projected on an eye to be examined is guided to an optical sensor by a light receiving optical system, and the output of the optical sensor is used as a basis. An ophthalmologic apparatus that automatically adjusts the alignment of a measurement unit with respect to an eye to be examined is known.

In such an ophthalmologic apparatus, an examiner uses a joystick or the like to move a measurement optical axis to near the apex of a cornea of a subject's eye while watching a viewfinder or a monitor (coarse alignment adjustment). When the coarse alignment adjustment is completed, automatic alignment adjustment is started based on the output of the optical sensor.

[0004]

However, in an ophthalmologic apparatus having such an automatic alignment function, there is a problem that a malfunction may occur depending on the operation method, the state of the eye to be inspected, and the like.

For example, when the subject blinks during automatic alignment adjustment, reflected light from the eyelids or eyelashes may enter the optical sensor. As a result, the automatic alignment adjustment mechanism may move the measuring unit in a direction completely different from the desired direction. When such a malfunction occurs, the examiner has to once move the measuring unit away from the subject's eye or press the reset switch to cancel the automatic alignment mode.

In the stage of coarse alignment adjustment (performed by the examiner manually operating a joystick or the like) before automatic alignment adjustment, reflected light from the eyelids and cheeks may enter the optical sensor. The automatic alignment adjustment mechanism may malfunction due to some kinds of noise light.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the present invention automatically discriminates such noise light from light reflected from near the apex of the cornea of the eye to be examined. An object of the present invention is to provide an ophthalmologic apparatus that can effectively prevent a malfunction of an automatic alignment adjustment mechanism.

In order to solve the above-mentioned problems, an ophthalmologic apparatus according to the present invention comprises: an apparatus main body; first alignment detecting means for detecting a shift of an optical axis between the apparatus main body and an eye to be inspected; A second alignment detecting means for detecting a distance from the eye to be inspected, and the apparatus body being automatically moved with respect to the eye based on an output of the first alignment detecting means and an output of the second alignment detecting means. An ophthalmologic apparatus having an alignment drive unit for performing alignment.
A means for starting or stopping the operation of the alignment driving means based on detection results of the first alignment detecting means and the second alignment detecting means.

An ophthalmologic apparatus according to the present invention comprises:
First alignment detecting means for optically detecting a shift of an optical axis between the apparatus main body and the eye to be inspected, and second alignment detecting means for optically detecting a distance between the apparatus main body and the eye to be inspected; An alignment driving means for automatically aligning the apparatus main body with respect to an eye to be inspected based on an output of the first alignment detecting means and an output of the second alignment detecting means; And a means for starting or stopping the operation of the alignment driving means based on an amount of light detected by the alignment detecting means and the second alignment detecting means.

In the above apparatus, the present invention is characterized in that the operation of the alignment driving means is started when the light quantity level value detected by the second alignment detecting means becomes larger than a predetermined light quantity level value. Features.

An ophthalmologic apparatus according to the present invention comprises: an apparatus main body;
First alignment detecting means for detecting a shift of an optical axis between the apparatus main body and the eye to be inspected, second alignment detecting means for detecting a distance between the apparatus main body and the eye to be inspected, and the first alignment detecting means An ophthalmologic apparatus comprising: an alignment driving means for automatically aligning the apparatus main body with respect to the subject's eye based on an output of the means and an output of the second alignment detecting means. 2 Based on the time change of the detection result of the alignment detecting means, determine the blinking state of the subject's eye,
Means for starting or stopping the operation of the alignment driving means in accordance with the blinking timing of the eye to be inspected.

In the above apparatus, the present invention is characterized in that alignment between the apparatus main body and the subject's eye can be executed by an operation of a subject.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an intraocular pressure measuring apparatus as an ophthalmologic apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1, FIG. 2 and FIG. 3 are views showing the configuration of an intraocular pressure measuring apparatus which is an ophthalmologic apparatus according to an embodiment of the present invention. 1, 2, and 3, an intraocular pressure measuring apparatus according to an embodiment of the present invention includes an anterior ocular segment observation optical system 10, an XY direction alignment index light projection optical system 20, an XY direction alignment detection optical system 30, It has a direction alignment index light projection optical system 50, a Z direction alignment light detection optical system 70, and a fixation target projection optical system 80. In the X direction,
The Y direction indicates a direction parallel to the surface of the subject's face (vertical direction and left and right direction), and the Z direction indicates a direction perpendicular to the surface of the subject's face (front-back direction). I have.

The apparatus for measuring tonometry according to the embodiment of the present invention further includes an injection nozzle 100, an air supply unit 101, an applanation sensor 102, an A / D (analog / digital) converter 103, a control circuit 104, and a drive circuit. 105, image processing circuit 106, display unit 107, memory unit 10
8, an XY-direction movement control mechanism 109a and a Z-direction movement control mechanism 109b.

The anterior segment observation optical system 10 for observing the anterior segment of the eye E is provided with a plurality of anterior segment units arranged on the left and right of the eye E to directly illuminate the anterior segment of the eye E with infrared light. Observation light source 11,
It has half mirrors 12 and 14, an objective lens 13, and a CCD (charge coupled device) camera 16, and has half mirrors 12 and 14, an objective lens 13, and a CCD.
The camera 16 is arranged along the optical axis O1. The reflected light from the anterior segment of the eye E illuminated by the anterior segment observation light source 11 is guided to the CCD camera 16 via the half mirror 12, the objective lens 13, and the half mirror 14,
Obtained as an anterior segment image.

An XY direction alignment index for projecting, on the cornea C of the eye E, an alignment index light used for performing alignment in the XY directions between the apparatus main body (apparatus optical system) of the tonometry apparatus and the eye E. Light projection optical system 2
Numeral 0 denotes a light source 21 that emits infrared light, a condenser lens 22, an aperture stop 23, a pinhole plate 24 that forms an alignment index, a dichroic mirror 25, and an arrangement on the optical path such that the focal points coincide with the pinhole plate 24. Projection lens 26 and the half mirror 12. The infrared light emitted from the light source 21 is collected by the condenser lens 22,
The light passes through the aperture stop 23 and is guided to the pinhole plate 24.
The light that has passed through the pinhole plate 24 is reflected by the dichroic mirror 25, becomes a parallel light beam by the projection lens 26, is reflected by the half mirror 12, and is projected on the cornea C.

An XY direction alignment detecting optical system 30, which receives reflected light of the alignment index light from the cornea C of the eye E to detect the relative positions of the apparatus main body and the cornea C in the XY directions, includes half mirrors 12 and 14, Objective lens 1
3 and an XY direction alignment detection sensor 31. The alignment target light projected onto the cornea C by the XY-direction alignment target light projection optical system 20 and reflected by the cornea C passes through the half mirror 12 and passes through the objective lens 1.
The light is converged at 3 and a part of the light is reflected by the half mirror 14 and enters the XY direction alignment detection sensor 31. X
The Y-direction alignment detection sensor 31 is configured by a light receiving element capable of detecting a position such as a PSD (position detector), and uses, for example, a two-dimensional PSD. In addition, you may comprise so that two one-dimensional PSD may be used.

The XY direction alignment detection circuit 91a
A relative position in the XY direction between the apparatus body and the cornea C of the eye E is calculated based on the output of the XY direction alignment detection sensor 31, and position information 111 indicating the calculation result is output to the control circuit 104. On the other hand, the light transmitted through the half mirror 14 is guided to the CCD camera 16. Output information 112 of the CCD camera 16 is output to the control circuit 104, and predetermined image processing is performed by the image processing circuit 106.
By this image processing, the anterior segment image 41 and the bright spot image R of the eye E are displayed on the display screen 107a of the display unit 107, as shown in FIG. In FIG. 4, an alignment area 40 is an area where automatic alignment adjustment is possible. The examiner determines a bright spot image R indicating the position of the optical axis O1 of the apparatus optical system.
The apparatus body is moved up, down, left, and right (XY directions) using a joystick (not shown) so that is located at the center of the alignment area 40, and measurement is performed in a direction in which the optical axis O1 of the apparatus optical system matches the eyeball optical axis of the eye E to be inspected. Move the part.
When the bright spot image R enters the alignment area 40, the XY direction movement control mechanism 109a is driven. This gives X
Automatic alignment adjustment is started by the Y-direction movement control mechanism 109a.

A Z-direction alignment index light projection optical system 50 for irradiating the cornea C of the subject's eye E with a slit light for performing alignment in the Z direction between the apparatus main body of the tonometry apparatus and the subject's eye E in an oblique direction. Is a light source 51 that emits infrared light, a condenser lens 52, a slit plate 53, a dichroic mirror 44, an aperture stop 45, and an objective lens 46.
Having. The infrared light emitted from the light source 51 is converged by the condenser lens 52 and passes through the slit plate 53. The passing light is reflected by the dichroic mirror 44, passes through the aperture stop 45, is focused by the objective lens 46, and irradiates the cornea C of the eye E to be examined.

Z-direction alignment index light projection optical system 50
The reflected light from the cornea C of the light irradiated by the
The Z-direction alignment detecting optical system 70 for detecting a position in the direction comprises an objective lens 61, a dichroic mirror 6
2 and a Z-direction alignment detection sensor 71. The reflected light from the cornea C of the light illuminated by the Z-direction alignment index light projection optical system 50 is
Are focused, guided by the dichroic mirror 62, reflected, and incident on the Z-direction alignment detection sensor 71.
The Z-direction alignment detection sensor 71 is constituted by a light sensor such as a line sensor or a one-dimensional PSD. The Z direction alignment detection circuit 91b detects the peak position of the amount of light based on the output of the Z direction alignment detection sensor 71. Thereby, the position in the Z direction is detected. The position information 110 is output from the Z-direction alignment detection circuit 91b to the control circuit 104. Based on this detection information, the apparatus main body is moved back and forth (Z direction) with respect to the eye E by the Z direction movement control mechanism 109b to secure the working distance.
That is, the Z-direction alignment detection optical system 70 is set so that the working distance becomes OK when the peak of the amount of received light is detected at a predetermined address of the line sensor constituting the Z-direction alignment detection sensor 71.

The fixation target projection optical system 80 for projecting a fixation target image onto the eye E to be examined includes a fixation target projection light source 8 that emits visible light.
1, a pinhole plate 82, a dichroic mirror 25, a projection lens 26, and a half mirror 12.
Fixation target light, which is visible light emitted from the fixation target projection light source 81, passes through the dichroic mirror 25 via the pinhole plate 82, becomes a parallel light flux by the projection lens 26, and is reflected by the half mirror 12. Then, the image is projected on the eye E to be examined. The line of sight of the subject's eye E is the half mirror 12
The fixation target light reflected by is fixed by gazing at the fixation target light.

The air supply unit 101 includes the injection nozzle 10
An air pulse is emitted to the cornea C of the eye E through 0 to deform the cornea C.

The applanation sensor 102 optically detects the cornea C deformed by the air pulse from the injection nozzle 100. Specifically, the cornea C is irradiated with the detection light simultaneously with the emission of the air pulse to the cornea C. This detection light is reflected by the deformed cornea C, and the reflected light is received by the applanation sensor 102 and converted into an electric signal. This electric signal is converted into a digital signal by an A / D (analog / digital) converter 103 and then input to a control circuit 104.

The control circuit 104 comprises a CPU (central processing unit) 104a and a program memory 104b. The CPU 104a stores the program memory 10
The control / processing of the entire intraocular pressure measurement device is performed according to various control / processing programs stored in 4b.

Incidentally, the amount of detection light reflected by the cornea C, which is received by the cornea C, increases with the start of the deformation of the cornea C and reaches a peak when the cornea C is applanated. Is determined by the CPU 104a.

The drive circuit 105 drives the air supply unit 101 when measuring intraocular pressure under the control of the CPU 104a.

The memory unit 108 stores setting conditions and the like for executing and stopping automatic alignment adjustment / automatic intraocular pressure measurement described later.

Next, the operation of the tonometry apparatus according to the embodiment of the present invention will be described.

In the automatic alignment adjustment / automatic intraocular pressure measurement in the intraocular pressure measurement apparatus according to the present embodiment, the measurement operation is temporarily stopped when three intraocular pressure measurements are completed. this is,
When the bright spot image R is present in the alignment area 40, the automatic alignment adjustment / automatic measurement of the intraocular pressure is repeatedly performed, so as to prevent the burden on the patient more than necessary. The suspension of the tonometry is performed by switching the RL switch for switching the measurement target of the left and right eyes E (for example, switching the tonometry from the left eye to the right eye), switching the front and rear of the observation lens, and the clear switch. , And until the printing of an intraocular pressure measurement result by a printing unit (not shown) is completed. The number of times of measuring the intraocular pressure until the operation of measuring the intraocular pressure temporarily stops is not limited to three, and can be set arbitrarily.

FIG. 5 is a diagram showing each measurement site of the cornea of the eye to be examined in which the XY direction level value and the Z direction level value are actually measured by the intraocular pressure measuring apparatus according to the embodiment of the present invention. FIG. 6 shows the results of incident light level conversion values of the XY direction level value and the Z direction level value actually measured at each measurement site of the cornea of the eye shown in FIG. 5 by the intraocular pressure measuring apparatus according to the embodiment of the present invention. FIG. 6, the vertical axis indicates a detection level value (arbitrary level value) of reflected light from each measurement site of the cornea C of the eye E shown in FIG. 5, and the horizontal axis indicates each measurement site corresponding to the detected reflected light. Is shown.

FIG. 6 shows a light quantity conversion level value incident on the two-dimensional PSD of an XY direction alignment detection circuit 91a for detecting the position in the XY direction of the optical axis O1 of the apparatus optical system with respect to the optical axis of the eye E of the eye E. Device operating position (intraocular pressure measurement position) in the Z direction with respect to the vertex of cornea C of eye E to be examined
Is shown in terms of the light amount conversion level value incident on the one-dimensional PSD of the Z-direction alignment detection circuit 91b for detecting.

These light quantity conversion level values are determined by the fact that the alignment position of the eye E to be examined with respect to the cornea C
In the direction, when the position coincides with the alignment origin (reference position), the adjustment is performed such that the XY direction level value Lxy becomes 1200 (arbitrary level value) and the Z direction level value Lz becomes 600 (arbitrary level value). It is needless to say that these numerical values are merely examples, and do not limit the scope of the present invention.

The alignment of the apparatus main body with respect to the eye E is automatically performed with the subject such as a patient's eye open. In this case, the XY direction and the Z direction near the vertex of the cornea of the eye E to be inspected are used. In the light amount conversion level value, the XY direction level value is larger than the Z direction level value (Lxy> L).
z).

However, when the subject closes his eyes by blinking or the like and his eyelashes are over his eyes, the relationship Lxy> Lz does not hold, as is clear from FIG. The XY direction level value is smaller than the Z direction level value (Lxy <Lz). Accordingly, the ratio between the XY direction level value and the Z direction level value is obtained, and if it is determined that the cornea C of the eye E is not correctly detected based on the ratio, the apparatus main body is aligned with the eye E. Therefore, the automatic alignment adjustment and the automatic measurement of the intraocular pressure are stopped.

The automatic alignment adjustment and the stop of the automatic measurement of the intraocular pressure can be more reliably performed by setting a predetermined threshold value other than the relationship of Lxy <Lz.
For example, the conditions for stopping the automatic alignment adjustment and the automatic measurement of the intraocular pressure are set as in the following (1) or (2).
That is, (1) Lxy <Lz, or Lxy <500, or Lz <200 (500 and 200 are arbitrary level values). (2) Lxy <aLz, or Lxy <b, or L
z <c (a, b, and c are arbitrary constants) The above numerical values can be changed by adjusting the light amount conversion level value at the alignment origin (reference position).

Here, the automatic alignment adjustment in the tonometry apparatus according to the embodiment of the present invention will be described with reference to FIG. FIG. 7 is a control flowchart showing automatic alignment adjustment in the tonometry apparatus according to the embodiment of the present invention. This automatic alignment adjustment is performed by the control circuit 104.
Under the control of the CPU 104a.

In FIG. 7, in step A1, the XY direction level value Lxy and the Z direction level value Lz detected by the XY direction alignment detecting circuit 91a and the Z direction alignment detecting circuit 91b are obtained. In the processing after step A2, it is determined whether to execute (continue) or stop the above-described automatic alignment adjustment and automatic intraocular pressure measurement.

When Lxy is smaller than Lz in step A2, when Lxy is smaller than 500 in step A3, or when Lz is 20 in step A4.
If it is smaller than 0, the automatic alignment adjustment operation is stopped (step A5). Specifically, the operations of the XY direction movement control mechanism 109a and the Z direction movement control mechanism 109b are stopped. At this time, if the automatic measurement of the intraocular pressure is performed, the automatic measurement of the intraocular pressure is also stopped. Specifically, the operation of the drive circuit 105 is stopped.

On the other hand, in step A2, Lxy becomes Lz
If it is the above, Lxy is 500 in step A3.
If Lz is greater than or equal to 2 in step A4,
If it is not less than 00, it is determined in step A6 whether the apparatus main body (apparatus optical system) has been aligned with the eye E. In step A6, the apparatus main body is
When the alignment is OK and the alignment is OK, measurement of intraocular pressure is started (step A8).

On the other hand, if the alignment is not OK in step A6, the automatic alignment adjustment operation is executed (continued) (step A7). That is, the process returns to the process of step A1, and the above process is repeated.

It is to be noted that since blinking or the like often occurs once and repeats several times, once the automatic alignment adjustment and the automatic measurement of the intraocular pressure are once stopped, the automatic alignment adjustment and the automatic intraocular pressure are performed until a predetermined time elapses. By continuing the measurement stop state, the tonometry apparatus according to the present invention can be more effectively utilized.

When the subject closes his / her eyes, X
Since the Y-direction level value and the Z-direction level value change continuously, changes in these level values are continuously detected, and if a threshold value is provided, whether the subject's eyes are surely opened or not is determined. It is also possible to more reliably determine when the subject's eyes are opened and the like.

Further, the present invention can be applied to an ophthalmologic apparatus having a self-alignment function in which the subject himself can adjust the alignment by himself. By providing a buzzer or the like that generates a signal from the ophthalmic apparatus that prompts the subject to blink in such an ophthalmic apparatus, the subject can close or open the eyelids according to the generation of the signal. Thus, the subject's eye can be reliably inspected at the moment when the subject's eye opens. In addition,
The examiner other than the subject may prompt the blinking.

Further, in the present embodiment, the tonometry apparatus has been described, but the present invention can be applied to other ophthalmologic apparatuses.

[0046]

As described above, according to the present invention, when the eyelids and eyelashes of the subject are at the alignment position which is the optical axis of the apparatus optical system, the automatic alignment adjustment and the automatic measurement of the intraocular pressure are reliably performed. Can be stopped. This can prevent unnecessary pain from being applied to the subject without performing unnecessary automatic alignment adjustment or intraocular pressure measurement.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a part of a configuration of an intraocular pressure measuring apparatus which is an ophthalmologic apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of a configuration of an intraocular pressure measurement device according to an embodiment of the present invention.

FIG. 3 is a diagram showing a part of the configuration of an intraocular pressure measurement device according to an embodiment of the present invention.

FIG. 4 is a diagram showing a display screen such as an anterior segment image displayed on a display unit of the tonometry apparatus according to the embodiment of the present invention.

FIG. 5 shows an X-ray image obtained by the tonometry apparatus of the embodiment of the present invention
The figure which shows each measurement site | part of the cornea of the eye to be examined in which a Y direction level value and a Z direction level value are actually measured.

FIG. 6 shows the results of the incident light level conversion values of the XY-direction level value and the Z-direction level value actually measured at each measurement site of the cornea of the eye shown in FIG. 5 by the tonometry apparatus according to the embodiment of the present invention. FIG.

FIG. 7 is a control flowchart showing automatic alignment adjustment in the intraocular pressure measurement device according to the embodiment of the present invention.

[Explanation of symbols]

 E eye to be examined C cornea 10 anterior ocular segment observation optical system 20 XY-direction alignment target light projection optical system 30 XY-direction alignment detection optical system 50 Z-direction alignment target light projection optical system 70 Z-direction alignment light detection optical system 80 fixation target projection Optical system 100 Injection nozzle 101 Air supply unit 102 Applanation sensor 103 A / D converter 104 Control circuit 104a CPU 104b Program memory 105 Drive circuit 106 Image processing circuit 107 Display unit 108 Memory unit 109a XY direction movement control mechanism 109b Z direction movement Control mechanism

Claims (5)

[Claims] 1. An apparatus main body, first alignment detecting means for detecting a shift of an optical axis between the apparatus main body and an eye to be inspected, and a second alignment detecting means for detecting a distance between the apparatus main body and an eye to be inspected.
An ophthalmologic apparatus comprising: an alignment detecting unit; and an alignment driving unit for automatically aligning the apparatus main body with respect to an eye to be examined based on an output of the first alignment detecting unit and an output of the second alignment detecting unit. An ophthalmologic apparatus comprising: means for starting or stopping the operation of the alignment driving means based on detection results of the first alignment detecting means and the second alignment detecting means. 2. An apparatus main body; first alignment detecting means for optically detecting a shift of an optical axis between the apparatus main body and an eye to be inspected; and optically determining a distance between the apparatus main body and the eye to be inspected. A second alignment detecting means, and an alignment driving means for automatically aligning the apparatus main body with the subject's eye based on the output of the first alignment detecting means and the output of the second alignment detecting means. An ophthalmologic apparatus comprising: means for starting or stopping the operation of the alignment driving means based on the amount of light detected by the first alignment detecting means and the second alignment detecting means. Ophthalmic device. 3. An operation of said alignment driving means is started when a light quantity level value detected by said second alignment detecting means becomes larger than a predetermined light quantity level value. An ophthalmologic apparatus according to item 1. 4. An apparatus main body, first alignment detecting means for detecting a deviation of an optical axis between the apparatus main body and an eye to be inspected, and a second alignment detecting means for detecting a distance between the apparatus main body and the eye to be inspected.
An ophthalmologic apparatus comprising: an alignment detecting unit; and an alignment driving unit for automatically aligning the apparatus main body with respect to an eye to be examined based on an output of the first alignment detecting unit and an output of the second alignment detecting unit. Determining a state of blinking of the eye to be inspected based on a temporal change in detection results of the first alignment detecting means and the second alignment detecting means, and activating the alignment driving means in accordance with the timing of blinking of the eye to be inspected; An ophthalmologic apparatus comprising: means for starting or stopping the operation. 5. The ophthalmologic apparatus according to claim 4, wherein the alignment between the apparatus main body and the subject's eye can be executed by an operation of a subject.