JP2018050922A - Ophthalmic apparatus and ophthalmic apparatus alignment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and accurately perform alignment processing on a measurement light optical system with a cornea vertex of a subject eye.CONSTITUTION: Provided is a non-contact tonometer S comprising a head part 7 for measuring a subject eye E, a drive mechanism 100 for moving the head part, and a drive control part 150. A reflection image of the subject eye E made off a cornea vertex T by a first light source 41 is captured by a first camera 43, and a reflection image at an iris 32 is captured by a second camera 44. The first light source 41 and the first camera 43 are disposed symmetrically with an angle α relative to an axis O1 of the head part 7 on a plane containing the axis O1. The second light source 42 and the second camera 44 are disposed symmetrically with an angle α relative to the axis O1 of the head part 7 on a plane containing the axis O1. The drive control part 150 controls the drive mechanism 100 on the basis of two pairs of reflection images to align the head part 7 with the cornea vertex T of the subject eye E. Before this alignment processing, first alignment processing is performed in advance on the basis of an anterior eye part image of the subject eye E.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ophthalmologic apparatus for acquiring data of an eye to be examined and an alignment method in the ophthalmologic apparatus.

  The ophthalmologic apparatus includes an ophthalmologic measuring apparatus for measuring the characteristics of the eye to be examined and an ophthalmologic photographing apparatus for obtaining an image of the eye to be examined.

As an ophthalmologic measurement device, an ocular refraction examination device (refractometer, keratometer) that measures the refractive characteristics of the eye to be examined, a tonometer, a specular microscope that obtains corneal properties (corneal thickness, corneal endothelial cell density, etc.) And a wavefront analyzer that obtains aberration information of the eye to be examined using a Hartmann-Shack sensor.
Moreover, as an ophthalmologic photographing apparatus, an optical coherence tomography (Optical Coherence Tomography, OCT) is used to obtain a tomographic image, a fundus camera for photographing a fundus, or laser scanning using a confocal optical system. And a scanning laser opthalmoscope (SLO) that obtains an image of the fundus.

  In an ophthalmic examination using such an apparatus, an alignment process between the optical system and the eye to be examined is important from the viewpoint of accuracy and accuracy of the examination. In general, there are an operation for aligning the optical axis of the eye to be examined and the optical system (XY alignment) and an operation for adjusting the distance between the eye to be examined and the optical system to a predetermined working distance (Z alignment). .

  With respect to such alignment, there are those that perform XY alignment and Z alignment based on a pupil image captured by a stereo camera (see Patent Document 1, Patent Document 2, and Patent Document 3). This stereo camera has a wide alignment range and does not require manual alignment, and in most cases, automatic alignment is possible.

JP 2013-248376 A JP 2014-113385 A JP 2014-124370 A

  However, since the alignment process using a conventional stereo camera is based on the distance between the reference position of the device and the pupil, the position of the corneal apex cannot be determined due to individual differences in the anterior chamber depth. In Patent Document 3, a method for correcting the depth position information of the pupil image using the corneal refractive power is studied. In order to obtain the corneal refractive power, a mechanism for measuring the curvature of the cornea is provided separately. There is a need.

  Therefore, since the stereo camera method is affected by individual differences such as anterior chamber depth and corneal curvature as a working distance alignment means, it cannot be used in an apparatus that requires alignment with the corneal apex.

  The present invention has been made in view of the above problems, and provides an ophthalmologic apparatus and an ophthalmologic apparatus alignment method capable of quickly and accurately aligning a measurement optical system to a corneal apex of an eye to be examined. Is an issue.

  The invention according to claim 1, which solves the above-described problem, is a head unit that is disposed in proximity to the eye to be examined and that measures the eye to be examined, and a driving unit that moves the head part relative to the eye to be examined. And a drive control unit that controls the driving unit to align the head unit with the apex of the eye to be examined, and the measurement is within a plane including the measurement axis of the head unit. A light source arranged on a line segment that forms a predetermined angle with respect to the measurement axis with respect to an assumed position of the apex of the subject eye assumed as an axis, and a line symmetry position with the measurement axis as a symmetry axis A reflection image acquisition device that is arranged on another set line segment and acquires a reflection image of the light source by the eye to be inspected is a set, and the combination of the light source and the reflection image acquisition device is different from each other. Place two or more sets to get The drive control unit, and controls to the head portion of said drive means on the basis of the two or more sets of reflected images aligned relative to the apex of the subject's eye.

  Similarly, the invention according to claim 2 is the ophthalmologic apparatus according to claim 1, further comprising an anterior ocular segment image acquisition device that acquires an anterior ocular segment image of the eye to be examined, wherein the drive control unit includes the anterior ocular segment. It is characterized in that alignment control based on an image is performed.

  Similarly, the invention described in claim 3 is the ophthalmologic apparatus described in claim 2, wherein the anterior segment image acquisition device is the reflection image acquisition device.

  Similarly, the invention according to claim 4 is the ophthalmologic apparatus according to claim 2, wherein the anterior segment image acquisition device is an imaging device different from the reflection image acquisition device.

  Similarly, the invention described in claim 5 includes a head unit for measuring the eye to be examined that is disposed in proximity to the eye to be examined, and a drive unit that moves the head part relative to the eye to be examined. A method of aligning an ophthalmologic apparatus for controlling the driving means to align the head portion with the apex of the eye to be examined, wherein the method is within a plane including the measurement axis of the head portion and the measurement axis. Two or more light sources by two or more light sources arranged on two or more different line segments that form a predetermined angle with respect to the measurement axis with the assumed position of the assumed vertex of the eye to be examined as a base point. Obtaining a reflected image on two or more other line segments set at line symmetry positions with the measurement axis as a symmetry axis; and the head portion on the eye to be examined based on the two or more sets of reflected images. A step of aligning with respect to And wherein the Rukoto.

  Similarly, the invention according to claim 6 is the method of aligning an ophthalmologic apparatus according to claim 5, wherein the anterior ocular segment image of the eye to be examined is acquired, and the head unit based on the anterior ocular segment image is obtained. And a step of performing alignment.

  Similarly, the invention described in claim 7 includes a head unit for measuring the eye to be examined that is disposed in proximity to the eye to be examined, and a drive unit that moves the head part relative to the eye to be examined. A method of aligning an ophthalmologic apparatus for controlling the driving means to align the head portion with the apex of the eye to be examined, the step of obtaining an anterior ocular segment image of the eye to be examined, and the anterior eye A step of aligning the head portion based on a partial image, and a vertex of the eye to be examined which is assumed to be the measurement axis in a plane including the measurement axis of the head portion after performing the alignment processing consisting of Two or more reflection images of the two or more light sources arranged on two or more different line segments that form a predetermined angle with respect to the measurement axis with the assumed position of At the line symmetry position Performing an alignment process comprising: acquiring on the other two or more line segments, and aligning the head unit with respect to the eye to be inspected based on the two or more sets of reflected images. It is characterized by that.

  Similarly, the invention according to claim 8 includes a head unit for measuring the eye to be examined that is disposed in proximity to the eye to be examined, and a drive unit that moves the head part relative to the eye to be examined. A method of aligning an ophthalmologic apparatus for controlling the driving means to align the head portion with the apex of the eye to be examined, wherein the method is within a plane including the measurement axis of the head portion and the measurement axis. Two or more light sources by two or more light sources arranged on two or more different line segments that form a predetermined angle with respect to the measurement axis with the assumed position of the assumed vertex of the eye to be examined as a base point. Obtaining a reflected image on two or more other line segments set at line symmetry positions with the measurement axis as a symmetry axis; and the head portion on the eye to be examined based on the two or more sets of reflected images. And the step of aligning with If the predetermined alignment cannot be performed, a step of acquiring an anterior ocular segment image of the eye to be examined and a step of aligning the head unit based on the anterior segment image After performing the alignment processing, the predetermined predetermined value with respect to the measurement axis in a plane including the measurement axis of the head unit and preliminarily defined with respect to the measurement axis based on the assumed position of the apex of the eye to be examined assumed as the measurement axis Two or more reflected images by the eye to be examined of two or more light sources arranged on two or more different line segments forming an angle are set to two or more other lines set in line symmetry positions with the measurement axis as a symmetry axis. A positioning process is performed, which includes a step of acquiring in a minute and a step of positioning the head unit with respect to the eye to be examined based on the two or more sets of reflected images.

  According to the present invention, the apparatus main body can be quickly and accurately aligned with the corneal apex of the eye to be examined.

  That is, according to the ophthalmologic apparatus of the first aspect, the head unit is aligned with the vertex of the eye to be inspected based on the reflected image of the light source from two or more captured images captured by the two imaging devices. It is not necessary to consider the difference between the anterior chamber depth and the corneal curvature of the subject when adjusting the position of the subject.

  Further, according to the ophthalmologic apparatus according to claim 2, the alignment control based on the anterior segment image can be performed in combination with the control based on the reflected light, and the alignment processing is performed accurately and at high speed. Can do.

  According to the ophthalmologic apparatus of the third aspect, since the anterior ocular segment image acquisition means is the same imaging apparatus as the reflection image acquisition apparatus, the number of imaging apparatuses is not increased.

  In addition, according to the ophthalmologic apparatus of the fourth aspect, since the anterior ocular segment image acquisition device is an imaging device different from the reflected image acquisition device, it is optimal for the optimal position for acquiring the anterior ocular segment image and acquiring the reflected image. Can be arranged.

  According to the method for aligning an ophthalmologic apparatus according to claim 5, the head unit is aligned with the vertex of the eye to be inspected based on the reflected image of the light source from two or more captured images captured by the two imaging devices. Therefore, it is not necessary to consider the difference in the anterior chamber depth or the corneal curvature of the subject when adjusting the position of the head portion.

  According to the alignment method of the ophthalmologic apparatus according to claim 6, the alignment control based on the anterior ocular segment image can be performed in combination with the control based on the reflected light, and the alignment processing can be performed accurately and accurately. It can be done at high speed.

  In addition, according to the registration method of the ophthalmologic apparatus according to claim 7, after performing the alignment process based on the anterior segment image of the eye to be examined, the alignment process based on two or more sets of reflected images is performed. The head portion alignment process can be performed quickly and accurately.

  According to the alignment method in the ophthalmologic apparatus according to claim 8, first, alignment processing based on two or more sets of reflection images is performed, and if alignment is completed, the subsequent processing is not performed. Processing can be performed quickly.

BRIEF DESCRIPTION OF THE DRAWINGS The external appearance of the non-contact type tonometer which concerns on embodiment of this invention is shown, (a) is a front view, (b) is a side view which shows a use condition. It is a schematic diagram which shows the internal structure of the non-contact-type tonometer, (a) is a side view, (b) is a top view. It is a schematic diagram which shows the positional relationship of the to-be-examined eye, a camera, and a light source in the non-contact tonometer, (a) is a front view which shows the to-be-examined eye, the position of a camera, and a light source, (b) is a top view, (c). Is a side view. It is a block diagram which shows the control system of the non-contact-type tonometer ophthalmologic apparatus. It is a flowchart which shows the general | schematic operation | movement procedure of the non-contact type tonometer. It is a schematic diagram which shows the relationship between the Z direction position of a to-be-tested eye with respect to the imaging device in the non-contact-type tonometer, and a reflected image. It is a schematic diagram which shows the relationship between the X direction position of a to-be-tested eye with respect to the imaging device in the non-contact-type tonometer, and a reflected image. It is a schematic diagram which shows the relationship between the XYZ direction position of a to-be-tested eye with respect to the imaging device in the same non-contact-type tonometer, and a reflected image. It is a flowchart which shows the basic operation | movement procedure of the non-contact-type tonometer. It is a schematic diagram which shows the positional relationship of the to-be-tested eye, a camera, and a light source in the non-contact type tonometer in the ophthalmic apparatus which concerns on 2nd Embodiment of this invention, (a) shows the to-be-examined eye, the position of a camera, and a light source. A front view and (b) are top views. It is a schematic diagram explaining the non-contact type tonometer which concerns on other embodiment of this invention.

An ophthalmologic apparatus and an ophthalmologic apparatus alignment method according to embodiments for carrying out the present invention will be described. The present invention can be applied to any ophthalmic measurement apparatus, any ophthalmologic imaging apparatus, or any multifunction machine. That is, the present invention can be applied to a refractometer, a keratometer, a specular microscope, a tonometer, and the like as an ophthalmologic measuring apparatus.
In addition, the present invention can be applied to an OCT (optical coherence tomography) apparatus, a fundus camera, an SLO (scanning laser ophthalmoscope), and the like as an ophthalmologic photographing apparatus.
Hereinafter, a non-contact tonometer will be described as an example of the ophthalmologic apparatus according to the embodiment.

<Schematic configuration of non-contact tonometer>
1A and 1B show the appearance of a non-contact tonometer according to an embodiment of the present invention. FIG. 1A is a front view and FIG. 1B is a side view showing a use state. The non-contact tonometer S includes a support unit 1, a device base 2, a gantry 3, and a device body 4.

  The support part 1 is arrange | positioned at the apparatus base 2, and supports a test subject's face HB. The apparatus base 2 has a support portion 1. The apparatus base 2 is disposed on the installation table D, and the gantry 3 is disposed on the upper part. The gantry 3 is provided to be movable in the front-rear direction and the left-right direction with respect to the apparatus base 2. The front-rear direction (the direction along the optical axis of the non-contact tonometer S) is the Z direction, the left-right direction perpendicular to the optical axis is the X direction, and the vertical direction is the Y direction.

  The apparatus main body 4 including the head unit 7 disposed close to the eye E to be examined is provided on the top of the gantry 3 and is operated with respect to the gantry 3 by the operation of the driving mechanism 100 that is a driving unit disposed inside the apparatus main body 4. , Z direction, X direction, and Y direction are relatively moved. An airflow nozzle 8 is disposed in the head portion 7. The apparatus main body 4 may be structured to move in the Z, X, and Y directions as one unit without moving independently with respect to the gantry 3.

  The gantry 3 is provided with an operation knob 5 having a measurement button 5a, a monitor 6, and the like. The operation knob 5 is operated by an inspector, whereby the gantry 3 is moved back and forth, right and left, and up and down. In this example, the apparatus main body 4 moves back and forth and right and left by tilting the operation knob back and forth and right and left, and the apparatus main body 4 moves up and down by rotating the knob itself around the axis of the knob. Further, an airflow blowing nozzle 8 is provided on the front surface of the apparatus main body 4 through the anterior eye glass 12 (see FIG. 2) so as to face the subject's eye E to be examined. Further, the operation knob 5 may be configured to perform its function using a touch panel of the monitor 6 or an external mouse.

<Internal configuration of non-contact tonometer>
2A and 2B are schematic views showing the internal configuration of the non-contact tonometer, wherein FIG. 2A is a side view, FIG. 3B is a plan view, and FIG. It is a schematic diagram which shows a positional relationship, (a) is a front view which shows the position of a to-be-tested eye, a camera, and a light source, (b) is a top view, (c) is a side view.

  As shown in FIG. 2A, an air chamber 11, an intraocular pressure measurement system 10, an applanation light irradiation system 20 for measuring intraocular pressure, and a fixation light irradiation system 30 are arranged inside the apparatus main body 4. . In the present embodiment, as shown in FIGS. 2B and 3, the apparatus main body 4 includes a first light source 41 and a second light source 42 which are two illumination devices as a set of a light source and a reflected image acquisition device. The first camera 43 and the second camera 44 are disposed as two reflected image acquisition devices. As a result, two sets of the light source and the reflected image acquisition device are arranged. The first light source 41 and the second light source 42 are point light sources that emit infrared light, and the first camera 43 and the second camera 44 are digital imaging devices including an electronic image sensor that detects infrared light.

  In the present embodiment, as shown in FIG. 3A, the first light source 41 and the first camera 43 are only an angle β from the horizontal plane H passing through the axis O1 that is the measurement axis of the head unit 7 including the airflow spray nozzle 8. It is arranged on an inclined plane A. Further, the axis O2 of the first camera 43 is arranged on a line segment passing through the corneal apex T and forming an angle α with the axis O1, as shown in FIG. In addition, the first light source 41 is arranged in a line-symmetrical position with the first camera 43 with the axis O1 as the axis of symmetry in FIG.

  Similarly, as shown in FIG. 3A, the second light source 42 and the second camera 44 are arranged on a plane B inclined by an angle β from the horizontal plane H passing through the axis O1 to the opposite side of the plane A. Further, the axis O3 of the second camera 44 is arranged on a line segment that forms an angle α with the axis O1 along the corneal apex T as shown in FIG. 5B. In FIG. 2B, the second light source 42 is arranged in a line-symmetrical position with the second camera 44 with the axis O1 as the axis of symmetry.

  Thereby, the infrared rays from the first light source 41 are totally reflected by the corneal vertex T of the eye E, and the first camera 43 acquires the bright spot as a reflected image. Similarly, the infrared light from the second light source 42 is totally reflected at the corneal apex T of the eye E, and the second camera 44 acquires this bright spot as a reflected image. In this example, the first camera 43 and the second camera 44 photograph the eye E from below the horizontal plane H by an angle γ. This is to prevent the shooting from being hindered by wrinkles or wrinkles.

  Further, in this embodiment, as shown in FIG. 2A, the anterior segment illumination light source 19 is arranged, and the first camera 43 and the second camera 44 are pupils of the eye E to be examined by the anterior segment illumination light source 19. Is acquired as an anterior segment image. That is, the first camera 43 and the second camera 44 have both functions of a reflected image acquisition device and an anterior ocular segment image acquisition device.

  The 1st camera 43 and the 2nd camera 44 image | photograph each of the reflected image and the anterior eye part image by the to-be-tested eye E substantially simultaneously. Here, “substantially simultaneously” indicates that the photographing timing shift to such an extent that the eye movement can be ignored in photographing by the first camera 43 and the second camera 44 is permitted. As a result, two or more images when the eye E is in the same position can be acquired by a camera. Therefore, by analyzing these images, the positions of the pupils and bright spots can be specified in the XYZ directions.

  Air is sent from the air injection device 70 (see FIG. 4: not shown in FIG. 2) to the air chamber 11, and the sent air is jetted from the airflow spray nozzle 8 toward the eye E. In the figure, reference numeral 12 denotes an anterior eye glass, and reference numerals 13 and 14 denote chamber glass. In the air chamber 11, the air in the cylinder is compressed by a piston driven by a rotary solenoid, and the compressed air is sent to the air chamber 11.

  Behind the air chamber 11, optical axes of an intraocular pressure measurement system 10, an applanation light irradiation system 20, and a fixation light irradiation system 30 are arranged, and the intraocular pressure measurement system 10, the applanation light irradiation system 20, and the fixation light irradiation system. The 30 optical axes are arranged in the airflow spray nozzle 8. Further, a chamber window glass 14 is disposed in the air chamber 11, and an axis O 1 of the intraocular pressure measurement system 10, the applanation light irradiation system 20, and the fixation light irradiation system 30 passes through the chamber window glass 14. The chamber window glass 14 is inclined with a predetermined angle with respect to the axis O1 in order to eliminate the influence of light reflection.

<Optical system of non-contact tonometer>
As shown in FIG. 2A, the intraocular pressure measurement system 10 includes a first dichroic mirror 15, an imaging lens 16, an applanation sensor 17 including an infrared sensor, and a pinhole 18. The applanation light irradiation system 20 includes an applanation light source 21 that is an infrared light source and a diaphragm 22. Further, the fixation light irradiation system 30 includes visible light, for example, a green fixation light source 31 and a diaphragm 32. The applanation light irradiation system 20 and the fixation light irradiation system 30 are coupled by a second dichroic mirror 24, converted into parallel light by a collimator lens 25, guided to the first dichroic mirror 15, and the airflow blowing nozzle 8 from the air chamber 11. After that, the eye E is irradiated.

  In this embodiment, the applanation light source 21 of the applanation light irradiation system 20 irradiates the eye E with infrared light having a predetermined diameter. The applanation sensor 17 detects reflected light from the eye E. When air is ejected from the airflow spray nozzle 8 to the eye E, the change in the amount of reflected light based on the change in the corneal shape detected by the applanation sensor 17 is measured to measure the intraocular pressure.

  In the applanation light irradiation system 20, the infrared light from the applanation light source 21 passes through the diaphragm 22, is reflected by the second dichroic mirror 24, and is collimated by the collimator lens 25. Then, the light is reflected by the first dichroic mirror 15, passes through the inside of the chamber window glass 14 and the airflow spray nozzle 8, and illuminates the cornea of the eye E to be examined. The applanation light irradiation system 20 and the fixation light irradiation system 30 are combined coaxially by the second dichroic mirror 24 and irradiated to the eye E.

  The second dichroic mirror 24 transmits the wavelength in the visible light range from the fixation light irradiation system 30 and reflects the wavelength in the infrared light range from the applanation light irradiation system 20. The second dichroic mirror 24 is formed with a dielectric multilayer film having the characteristics described above. The first dichroic mirror 15 has a characteristic of substantially reflecting wavelengths in the visible light region, partially transmitting wavelengths in the infrared region, and reflecting partially. The second dichroic mirror 24 is a multilayer mirror, and generally has a transmittance of 50% and a reflectance of 50%, but may be configured to have a low transmittance and a high reflectance.

  The infrared light reflected by the cornea of the eye E passes through the inside of the airflow blowing nozzle 8, the chamber window glass 14, and the first dichroic mirror 15, passes through the imaging lens 16 and the pinhole 18, and passes through the applanation sensor 17. To. The applanation sensor 17 detects a change in the amount of infrared light reflected from the cornea and transmitted through the pinhole 18. Thereby, the intraocular pressure of the eye E is measured.

  That is, the cornea becomes flat due to the pressure of the jetted air and is recessed. The pinhole 18 is arranged so as to be conjugated with the light source by the imaging lens when the cornea becomes flat. Therefore, when the cornea changes from a convex surface to a flat surface and a concave surface, the maximum amount of light passes through the pinhole 18 and enters the applanation sensor 17. Therefore, it is determined that the cornea has become flat when the amount of light received by the applanation sensor 17 reaches the maximum after the start of air injection. Here, a pressure gauge for detecting the internal pressure of the air chamber 11 is disposed in the air chamber 11, and when the light amount becomes maximum (when the cornea becomes a flat surface), the detected pressure value is used as an intraocular pressure value. Measured.

  The subject fixes the line of sight to the measurement optical axis by fixing the image of the fixation light source 31 that forms an image at a substantially infinite distance. In addition, the stop can be illuminated with the fixation light source 31, and this stop can be used as a secondary light source.

<Control system for non-contact tonometer>
Next, a control system of the non-contact tonometer S according to the embodiment will be described. FIG. 4 is a block diagram showing a control system of the non-contact tonometer ophthalmologic apparatus. The non-contact tonometer S includes an air injection device 70 that introduces compressed air into the air chamber 11, a chin rest drive motor 81 that moves the chin rest of the support portion 1 up and down, an initial position switch 91, A drive mechanism 100 of the apparatus main body 4, a printer unit 110, a communication unit 120, and a control unit 130 are provided.

  The air injection device 70 includes a rotary solenoid 71 that drives a piston that pumps air that is pumped to the air chamber 11, and a pressure sensor 72 that measures the pressure in the air chamber 11.

  The initial position switch 91 is used to reset each movable part of the non-contact type tonometer S to the initial position when the non-contact type tonometer S is started or after measurement of the eye to be examined is completed. The drive mechanism 100 performs alignment by moving the apparatus body 4 relative to the support unit 1 in the XY and Z directions. The monitor 6 is composed of a liquid crystal display device, for example, and displays necessary information such as an anterior eye image captured by the first camera 43 and the second camera 44. The operation unit includes various operation means including the operation knob 5 described above. The operation unit may be configured to allow input from a touch panel attached to the monitor 6. The printer unit 110 prints measurement results and the like on a sheet. The communication unit 120 transmits a measurement result to an electronic medical record system or other devices, and receives a subject ID read by a barcode reader.

  The control unit 130 includes an arithmetic processing unit 140 and a drive control unit 150 that is a drive control device. The arithmetic processing unit 140 performs image processing and the like. The drive control unit 150 includes a main control unit 151 including a CPU (Central Processing Unit), a storage unit 152 including a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The main control unit 151 executes the control method of the ophthalmologic apparatus according to the present invention by the program stored in the storage unit 152 to perform each process described later.

<Schematic operation of non-contact tonometer S>
FIG. 5 is a flowchart showing a basic operation procedure of the non-contact tonometer. In order to measure the intraocular pressure of the subject with the non-contact tonometer S according to the present embodiment, the subject is first positioned on the support unit 1 (step S1), and then the first alignment process (step S2) is performed. Then, a second alignment process (step S3) is performed. With these processes, the tip of the airflow spray nozzle 8 is aligned with the eye E and the distance is adjusted with respect to the apex of the cornea. Then, after the alignment is completed, the intraocular pressure is measured (step S4).

<First alignment processing>
In the non-contact tonometer S according to the present embodiment, as the first alignment processing, an anterior ocular segment image is acquired by the first camera 43 and the second camera 44 that photograph the eye E from different directions. Rough alignment is performed in the XYZ directions based on the anterior segment image. After completion of the first alignment process, the apparatus body 4 is retracted by a specified amount (for example, 3 mm), and then the reflected image at the corneal apex of the eye E of the first light source 41 obtained by the first camera 43 and the second image are obtained. Based on the reflection image at the apex of the cornea of the eye E of the second light source 42 acquired by the camera 44, precise alignment in the XYZ directions is performed as the second alignment processing.

  Here, in the first alignment processing based on the pupil of the anterior segment image, the position of the pupil is detected by detecting the position of the pupil by a known method. However, in the first alignment process, it is difficult to precisely align the position with respect to the corneal apex T, particularly the position in the Z direction. This is because alignment is performed based on the position of the pupil on the back side of the cornea. Therefore, in this embodiment, after performing rough alignment in the first alignment processing, second alignment using the reflection image at the corneal apex is performed, and the alignment of the head portion 7 to the corneal apex is accurately performed. To do

<Second alignment processing>
The second alignment process will be described below. FIG. 6 is a schematic diagram showing the relationship between the Z-direction position of the eye to be examined with respect to the imaging apparatus and the reflected image in the non-contact tonometer, and FIG. FIG. 8 is a schematic diagram showing the relationship between the position of the subject's eye in the XYZ direction and the reflected image with respect to the imaging apparatus in the non-contact tonometer.

  The distance between the eye E and the tip of the airflow spray nozzle 8 will be described with reference to FIG. For example, the first camera 43 acquires a reflection image of the eye E of the first light source 41 by the cornea. As shown in FIG. 3A, a position away from the tip of the airflow spray nozzle 8 by WD is set as a base point ST which is an assumed position of the eye E. Then, when the corneal vertex T of the eye E is far from the base point ST (FIG. 6B), it coincides (FIG. 6C), and is close (FIG. 6D). Consider the reflection image.

  When the corneal vertex T of the eye E is far from the base point ST, as shown in FIG. 5B, the bright spot 61 of the reflected image 60 is generated from the axis O2 to the axis O1 side. The bright spot 61 is slightly blurred.

  When the corneal apex T of the eye E coincides with the base point ST, as shown in FIG. 5C, the bright spot 61 of the reflected image 60 is generated on the axis O2. The bright spot 61 appears in focus and clearly.

  Further, when the corneal apex T of the eye E is closer to the base point ST, as shown in FIG. 4D, the bright spot 61 of the reflected image 60 is generated by being shifted from the axis O2 to the opposite side to the axis O1. . The bright spot 61 is slightly blurred.

  Under such conditions, even if the eye E is displaced in the X direction, as shown in FIG. 7D, the bright spot 61 is generated on the axis O2 side from the axis O1. This is similar to the reflected image when the eye E to be examined shown in FIG. 6B is away from the base point ST. For this reason, a single camera may not be able to distinguish between a deviation in the X direction and a deviation in the Z direction. In the present embodiment, the reflected image (first reflected image R1) obtained by the first camera 43 and the reflected image obtained by the second camera 44 in the Z direction (far and near) of the eye E and the deviation in the X direction are obtained. The determination is made based on (second reflection image R2).

  FIG. 8 is a schematic diagram showing the relationship between the position in the XYZ direction of the eye to be examined and the reflected image with respect to the imaging apparatus in the non-contact tonometer. When the cornea vertex T of the eye E coincides with the base point ST, the bright spots 61 and 61 of the first reflection image R1 and the second reflection image R2 are generated at the center position. When the corneal apex T is closer to the base point ST, as shown in FIG. 4B, in the first reflection image R1 and the second reflection image R2, the two bright spots 61 and 61 are separated from the center position in the drawing. Leave in the direction. When the corneal apex T is far from the base point ST, as shown in FIG. 5C, in the first reflection image R1 and the second reflection image R2, the two bright spots 61 and 61 are the axes O2 and O3. Move to the O1 side.

  On the other hand, when the corneal apex T is displaced in the X direction, as shown in FIGS. 4D and 4E, the two bright spots 61 and 61 are on the axis O2 in the first reflection image R1 and the second reflection image R2. , Move in the same direction on the X axis from the axis O3. Further, when the corneal apex T is shifted in the Y direction, as shown in FIGS. 5F and 5G, in the first reflection image R1 and the second reflection image R2, the two bright spots 61 and 61 have an axis O2. , Move from the axis O3 on the Y axis in the opposite direction.

  In the present embodiment, the position of the corneal vertex T of the eye E with respect to the tip of the airflow spray nozzle 8 is acquired from the two reflected images acquired by the first camera 43 and the second camera 44 as described above. However, since this method uses the principle of “optical lever”, the minute displacement of the eye E is magnified and reflected in the reflected image. For this reason, if the corneal apex T of the eye E is largely deviated, the first camera 43 and the second camera 44 may not be able to detect them.

  Therefore, in this embodiment, the first camera 43 and the second camera 44 acquire the anterior segment image of the eye E, thereby performing a first alignment process, and further performing the second alignment process as described above. Alignment is performed based on the reflected image.

<Basic operation procedure of non-contact tonometer>
Details of the procedure for measuring intraocular pressure will be described below. FIG. 9 is a flowchart showing an operation procedure of the non-contact tonometer. First, in the non-contact tonometer S, the control unit 130 turns on the fixation light source 31 and irradiates the eye E with fixation light (step SA1). Next, the control unit 130 performs a first alignment process. That is, the control unit 130 turns on the anterior segment illumination light source 19 and illuminates the eye E with infrared light (step SA2). Thereby, the anterior segment image of the eye E is captured by the first camera 43 and the second camera 44. The control unit 130 searches for the pupil based on the two anterior segment images (step SA3), detects the pupil (Yes in step SA4), calculates the pupil center (step SA5), and determines the position of the pupil center. Based on the above, the drive mechanism 100 is driven to perform alignment (XYZ alignment) in the XYZ directions (step SA6).

  If no pupil is detected in this process (NO in step SA4), manual alignment by the examiner is performed (step SA14). The pupil cannot be detected when the support unit 1 is not adjusted with respect to the face HB and the first camera 43 and the second camera 44 are imaging a portion of the face HB other than the eye E. The inspector adjusts the height of the support portion 1 so that the subject's face HB is correctly placed on the support portion 1, and the inspector operates the operation knob 5 while observing the monitor 6 to move the drive mechanism 100. By operating, the apparatus main body 4 is moved and adjusted so that the eye E can be observed with the first camera 43 and the second camera 44.

  In the state where the XYZ alignment has been completed (step SA7), the airflow spray nozzle 8 may not be at an appropriate position with respect to the eye E. For this reason, the control unit 130 performs the second alignment process. Prior to this process, the control unit 130 drives the drive mechanism 100 to retract the airflow spray nozzle 8 by, for example, 3 mm in the Z direction (step SA7).

  Next, the control unit 130 performs a second alignment process. First, the control unit 130 turns on the first light source 41 and the second light source 42 (step SA8). Then, the first camera 43 and the second camera 44 acquire reflection images of the first light source 41 and the second light source 42 at the corneal vertex T of the eye E (step SA9). Next, the control unit 130 calculates the center of gravity of the bright spot in each reflection image, and drives the drive mechanism 100 based on the positional relationship between the tip of the airflow spray nozzle 8 and the corneal vertex T of the eye E to be examined by the above-described method. Alignment in the XYZ directions (XYZ alignment) is performed (step SA11). And the control part 130 drives the air injection apparatus 70, injects air from the airflow spray nozzle 8 to the eye E to be examined, detects reflected light with the applanation sensor 17, and measures an intraocular pressure (step SA13). For XY alignment, the applanation light source 21 may be turned on during the alignment, and the alignment may be performed based on the position of the Purkinje image generated by reflection from the cornea.

  As described above, the non-contact tonometer S according to the present embodiment performs the first alignment process based on the two anterior segment images, and then retracts the apparatus main body 4 once, The second alignment is performed based on the two reflected images of the corneal apex T of the eye E to be inspected by the first light source and the second light source. Therefore, the non-contact tonometer S can directly detect the corneal apex T of the eye E, and it is not necessary to take into account the difference between the anterior chamber depth and the corneal curvature of the subject, and the cornea of the airflow spray nozzle 8 can be accurately measured. Alignment with the vertex T can be performed.

  In the example shown in FIG. 9, the first alignment process is performed to align the pupil of the eye to be examined, and thereafter the average anterior chamber depth (3 mm) is retracted to start the second alignment process. However, the alignment completion position in the first alignment process can be set to a position 3 mm in front of the pupil. In this case, it is possible to smoothly shift from the first alignment to the second alignment without being too close to the eye to be examined.

  In the example shown in FIG. 9, in the first alignment process, the anterior segment image is acquired using the first camera 43 and the second camera 44, but separately from the first camera 43 and the second camera 44. An anterior eye camera 23 (see FIG. 3), which is an infrared imaging device, is arranged, and the anterior eye image of the eye E can be acquired by the anterior eye camera 23. In this case, the first camera 43 and the second camera 44 are used exclusively for obtaining the reflected images of the first light source 41 and the second light source 42. In addition, although two sets of the light source and the camera for obtaining the reflected image are used, the number of sets may be two or more, and for example, three sets may be provided.

Second Embodiment
Next, a second embodiment of the present invention will be described. FIG. 10 is a schematic diagram showing the positional relationship between the eye to be examined, the camera, and the light source in the non-contact tonometer in the ophthalmic apparatus according to the second embodiment of the present invention. The front view which shows a position, (b) is a top view.

  In this embodiment, the 1st light source 41, the 2nd light source 42, the 1st camera 43, and the 2nd camera 44 are arrange | positioned on the horizontal surface H which passes along the axis | shaft O1 of the airflow spray nozzle 8. FIG. The first camera 43 and the first camera 43 are arranged with the axes O2 and O3 so as to form the same angle δ as the axis O3. In addition, reflecting members 45 and 46 made of a half mirror or a dichroic mirror are disposed on the axes O2 and O3 of the first camera 43 and the second camera 44, and the first light source 41 and the second light source 42 are connected to the first camera 43. The second camera 44 is disposed at the position of the mirror image. Thereby, the light from the first light source 41 and the second light source 42 is irradiated to the eye E along the axis O2 and the axis O3.

<Other embodiments>
In each of the above examples, the angle formed by the first light source 41 and the first camera 43 with the axis O1 and the angle formed by the second light source 42 and the second camera 44 with the axis O1 are the same. In the present invention, this angle can be different. FIG. 11 is a schematic diagram for explaining a non-contact tonometer according to another embodiment of the present invention.

  In the example shown in FIG. 11A, the angle a formed by the first light source 41 and the first camera 43 with respect to the axis O1, and the angle b formed by the second light source 42 and the second camera 44 with respect to the axis O1. It is a thing. In the example shown in FIG. 6B, the angle c formed by the first light source 41 and the first camera 43 with respect to the axis O1 is set, and the axes of the second light source 42 and the second camera 44 are made coincident with the axis O1. It is a thing. In this example, in the second camera 44, a half mirror 44c is disposed between the lens 44a and the imaging device 44b, and the light from the first light source 41 is guided to the axis O1. In order to arrange this in the non-contact tonometer S, for example, when the second camera 44 is added to the example shown in FIG. 2B, the applanation sensor 17 of the tonometry system 10 is reached. A new half mirror is arranged at an angle of 45 ° with respect to the axis O1 in the optical path to which the second camera 44 is attached. Also in these examples, as in the first embodiment and the second embodiment, two reflected images at the cornea vertex T of the light source can be acquired and the alignment process can be performed.

1: Supporting unit 2: Device base 3: Mounting base 4: Device body 5: Operation knob 5a: Measurement button 6: Monitor 7: Head unit 8: Airflow spray nozzle 10: Intraocular pressure measurement system 11: Air chamber 12: Anterior eye unit Window glass 14: Chamber window glass 15: First dichroic mirror 16: Imaging lens 17: Applanation sensor 18: Pinhole 19: Anterior illumination light source 20: Applanation light irradiation system 21: Applanation light source 22: Aperture 23: Anterior eye camera 24: second dichroic mirror 25: collimator lens 29: anterior eye area sensor 30: fixation light irradiation system 31: fixation light source 32: aperture 41: first light source 42: second light source 43: first Camera 44: Second camera 44a: Lens 44b: Image sensor 44c: Half mirror 45, 46: Reflective member 60: Reflected image 61: Bright spot 70: Air injection device 71: Rotary solenoid 2: pressure sensor 81: the chin rest drive motor 91: the initial position switch 100: the driving mechanism 110: the printer unit 120: Communication unit 130: control unit 140: arithmetic processing unit 150: drive control unit 151, the main controller 152: storage unit

Claims (8)

A head unit that is arranged close to the eye to be measured and measures the eye to be examined;
Drive means for moving the head portion relative to the eye to be examined;
In an ophthalmologic apparatus comprising: a drive control unit that controls the driving unit to align the head unit with the vertex of the eye to be examined.
It is arranged on a line segment that forms a predetermined angle with respect to the measurement axis in a plane including the measurement axis of the head portion, with the assumed position of the apex of the eye to be examined assumed as the measurement axis as a base point And a reflected image acquisition device that is arranged on another line segment set at a line symmetry position with the measurement axis as a symmetry axis, and obtains a reflected image of the light source by the eye to be examined. Two or more sets of reflection image acquisition devices are arranged to acquire the reflection images from different directions,
The drive control unit controls the drive unit based on the two or more sets of reflected images to align the head unit with the vertex of the eye to be examined. An anterior ocular segment image acquisition device that acquires an anterior ocular segment image of the eye to be examined;
The ophthalmologic apparatus according to claim 1, wherein the drive control unit performs alignment control based on the anterior ocular segment image.   The ophthalmologic apparatus according to claim 2, wherein the anterior ocular segment image acquisition apparatus is the reflection image acquisition apparatus.   The ophthalmologic apparatus according to claim 2, wherein the anterior ocular segment image acquisition device is an imaging device different from the reflection image acquisition device. A head unit that measures the eye to be examined disposed close to the eye to be examined; and a driving unit that moves the head unit relative to the eye to be examined, and controls the driving unit to control the head A method for aligning an ophthalmic apparatus for aligning a portion with a vertex of the eye to be examined,
Two or more different line segments that form a predetermined angle with respect to the measurement axis within a plane that includes the measurement axis of the head unit and that is based on the assumed position of the apex of the eye to be examined that is assumed for the measurement axis Obtaining two or more reflected images by the eye to be examined of two or more light sources arranged on the other two or more line segments set at line symmetry positions with the measurement axis as a symmetry axis;
Aligning the head with respect to the eye to be examined based on the two or more sets of reflected images;
A method for aligning an ophthalmic apparatus, comprising: Obtaining an anterior ocular segment image of the eye to be examined;
Aligning the head portion based on the anterior segment image;
The method for aligning an ophthalmic apparatus according to claim 5. A head unit that measures the eye to be examined disposed close to the eye to be examined; and a driving unit that moves the head unit relative to the eye to be examined, and controls the driving unit to control the head A method for aligning an ophthalmic apparatus for aligning a portion with a vertex of the eye to be examined,
Obtaining an anterior ocular segment image of the eye to be examined;
Aligning the head portion based on the anterior segment image;
After performing the alignment process consisting of
Two or more different line segments that form a predetermined angle with respect to the measurement axis within a plane that includes the measurement axis of the head unit and that is based on the assumed position of the apex of the eye to be examined that is assumed for the measurement axis Obtaining two or more reflected images by the eye to be examined of two or more light sources arranged on the other two or more line segments set at line symmetry positions with the measurement axis as a symmetry axis;
Aligning the head with respect to the eye to be examined based on the two or more sets of reflected images, and performing an alignment process comprising:
A method for aligning an ophthalmologic apparatus. A head unit that measures the eye to be examined disposed close to the eye to be examined; and a driving unit that moves the head unit relative to the eye to be examined, and controls the driving unit to control the head A method for aligning an ophthalmic apparatus for aligning a portion with a vertex of the eye to be examined,
Two or more different line segments that form a predetermined angle with respect to the measurement axis within a plane that includes the measurement axis of the head unit and that is based on the assumed position of the apex of the eye to be examined that is assumed for the measurement axis Obtaining two or more reflected images by the eye to be examined of two or more light sources arranged on the other two or more line segments set at line symmetry positions with the measurement axis as a symmetry axis;
Aligning the head portion with the eye to be examined based on the two or more sets of reflected images, and performing an alignment process comprising:
If the predetermined alignment is not possible,
Obtaining an anterior ocular segment image of the eye to be examined;
Aligning the head portion based on the anterior segment image;
After performing the alignment process consisting of
Two or more different line segments that form a predetermined angle with respect to the measurement axis within a plane that includes the measurement axis of the head unit and that is based on the assumed position of the apex of the eye to be examined that is assumed for the measurement axis Obtaining two or more reflected images by the eye to be examined of two or more light sources arranged on the other two or more line segments set at line symmetry positions with the measurement axis as a symmetry axis;
Aligning the head with respect to the eye to be examined based on the two or more sets of reflected images, and performing an alignment process comprising:
A method for aligning an ophthalmologic apparatus.