JP2020022854A - Ophthalmic imaging apparatus, and control method thereof - Google Patents

Abstract

To provide a new technology on an ophthalmic imaging apparatus for acquiring an image of an eye to be examined.SOLUTION: An ophthalmic imaging apparatus includes an illumination system, an imaging system, and a control unit. The illumination system includes an illumination light generation part. The illumination light generation part generates an illumination light that allows light volume distribution at least in a beam cross section to be changed. The illumination system illuminates the eye to be examined with the illumination light. The imaging system guides a return light of the illumination light from the eye to be examined to an imaging device. The control part specifies a region of attention in an image by analyzing the image acquired by the imaging device, and controls the light volume at an in-plane position of the illumination light corresponding to the region of attention according to a site included in the region of attention.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ophthalmologic photographing apparatus and a control method thereof.

  An ophthalmologic photographing apparatus is used to acquire an image of an eye to be examined. As an ophthalmologic photographing apparatus, a slit lamp microscope (slit lamp), a fundus camera, and the like are known.

  An ophthalmologic photographing apparatus generally includes an illumination system and a photographing system. The illumination system illuminates the subject's eye with illumination light. The imaging system guides the return light of the illumination light from the eye to be inspected to the imaging device. The ophthalmologic imaging apparatus acquires an image of the eye to be inspected using the imaging apparatus.

JP 2014-188339 A

  In a conventional ophthalmologic imaging apparatus, an illumination system illuminates an eye to be examined with illumination light having a uniform light amount in a light beam cross section (that is, spatially uniform illumination light), regardless of the position of the eye to be inspected. As a result, overexposure or crushing of black may occur due to a difference in reflectance for each part, and an image suitable for observation may not be obtained.

  Further, since the subject's eye is illuminated with illumination light having a uniform light amount in the light beam cross section, the subject may feel dazzling when strong light enters the pupil, which may give the subject discomfort. Further, there is a case where it becomes impossible to continue photographing and observation of the eye to be examined due to miosis.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a new technique of an ophthalmologic photographing apparatus for acquiring an image of an eye to be examined.

An ophthalmologic imaging apparatus according to an embodiment includes an illumination system, an imaging system, and a control unit. The illumination system includes an illumination light generation unit. The illumination light generation unit generates illumination light capable of changing at least a light amount distribution in a light beam cross section. The illumination system illuminates the subject's eye with illumination light. The imaging system guides the return light of the illumination light from the eye to be inspected to the imaging device. The control unit specifies a region of interest in the image by analyzing the image acquired by the imaging device, and according to a part included in the region of interest, an in-plane position of illumination light corresponding to the region of interest. Control the amount of light.
The control method of the ophthalmologic imaging apparatus according to the embodiment includes an acquisition step and a control step. The ophthalmologic photographing apparatus includes an illumination system and a photographing system. The illumination system includes an illumination light generation unit. The illumination light generator generates illumination light capable of changing at least the light amount distribution in the light beam cross section. The illumination system illuminates the subject's eye with illumination light. The imaging system guides the return light of the illumination light from the eye to be inspected to the imaging device. In the obtaining step, an image of the subject's eye is obtained by the imaging device. In the control step, a region of interest in the image is identified by analyzing the acquired image, and the amount of illumination light at the in-plane position of the illumination light corresponding to the region of interest is controlled according to a part included in the region of interest. Is done.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the new technique of the ophthalmologic imaging apparatus for acquiring the image of an eye to be examined.

1 is a schematic side view illustrating an example of an external configuration of an ophthalmologic photographing apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating an example of a configuration of an optical system of the ophthalmologic imaging apparatus according to the embodiment. FIG. 2 is a schematic diagram illustrating an example of a configuration of a control system of the ophthalmologic imaging apparatus according to the embodiment. It is an operation explanatory view of the ophthalmologic photographing apparatus according to the embodiment. It is an operation explanatory view of the ophthalmologic photographing apparatus according to the embodiment. It is a flowchart showing an example of operation | movement of the ophthalmologic imaging apparatus which concerns on embodiment. FIG. 2 is a schematic diagram illustrating an example of a configuration of an optical system of the ophthalmologic imaging apparatus according to the embodiment.

  An example of an embodiment of an ophthalmologic photographing apparatus according to the present invention will be described in detail with reference to the drawings. The contents of the documents described in this specification can be appropriately used as the contents of the following embodiments.

  Hereinafter, a slit lamp microscope will be described as an example of the ophthalmologic imaging apparatus according to the embodiment, but the ophthalmologic imaging apparatus according to the embodiment is not limited thereto. Ophthalmologic imaging apparatuses to which the present invention can be applied include, in addition to a slit lamp microscope, a fundus camera, a scanning laser ophthalmoscope (SLO), a laser light coagulation apparatus, and the like. Further, the imaging site by the ophthalmologic imaging apparatus according to the embodiment may be an arbitrary site of the eye to be inspected, and may be, for example, a cornea, a vitreous body, a crystalline lens, a ciliary body, and a corner in an anterior eye part. In the posterior segment, it may be the retina, choroid, or vitreous. The imaging region may be a region around the eye such as the eyelids or the eye socket.

  First, the direction is defined. The direction from the optical element located closest to the subject in the apparatus optical system toward the subject is defined as the front direction, and the opposite direction is defined as the rear direction. A horizontal direction orthogonal to the front direction is defined as a left-right direction. Further, a direction perpendicular to both the front-rear direction and the left-right direction is defined as a vertical direction.

[First Embodiment]
[Appearance configuration]
The external configuration of the slit lamp microscope according to this embodiment will be described with reference to FIG. A computer 100 is connected to the slit lamp microscope 1. The computer 100 performs various control processes and arithmetic processes. Note that instead of providing the computer 100 separately from the microscope main body (a housing for storing an optical system and the like), a configuration in which a similar computer is mounted on the microscope main body can be applied.

  The slit lamp microscope 1 is mounted on a table 2. Note that the computer 100 may be installed on another table or another place. The base 4 is configured to be movable in the horizontal direction via the moving mechanism 3. The base 4 is moved by tilting the operation handle 5.

  On the upper surface of the base 4, a support portion 15 that supports the observation system 6 and the illumination system 8 is provided. A support arm 16 that supports the observation system 6 is attached to the support unit 15 so as to be rotatable in the left-right direction. A support arm 17 for supporting the illumination system 8 is attached to the upper part of the support arm 16 so as to be rotatable in the left-right direction. The support arms 16 and 17 are independently rotatable coaxially.

  The observation system 6 is moved by manually rotating the support arm 16. The illumination system 8 is moved by manually rotating the support arm 17. In addition, each of the support arms 16 and 17 may be configured to be rotated by an electric mechanism. In that case, an actuator for generating a driving force for rotating each of the support arms 16 and 17 and a transmission mechanism for transmitting the driving force are provided. The actuator is constituted by, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears and a rack and pinion.

  The illumination system 8 generates illumination light, and illuminates the eye E with the generated illumination light. As described above, the illumination system 8 can swing right and left around the rotation axis. Thereby, the irradiation direction of the illumination light to the eye E is changed. The illumination system 8 may be configured to swing vertically. That is, the configuration may be such that the elevation angle and the depression angle of the illumination light can be changed.

  The observation system 6 has a pair of left and right optical systems for guiding the reflected light of the illumination light from the eye E. The observation system 6 is configured to include an imaging system. This optical system is housed in the lens barrel body 9. The optical path of the imaging system is coupled to the optical path of the observation system 6 within the lens barrel body 9. The end of the lens barrel body 9 is an eyepiece 9a. The examiner looks into the eye E by viewing the eyepiece 9a with the naked eye. As described above, by rotating the support arm 16, the lens barrel main body 9 can be rotated in the left-right direction. Thereby, the direction of the observation system 6 with respect to the eye E can be changed. Note that the reflected light of the illumination light includes various kinds of light passing through the eye E, such as scattered light, for example, and these various lights are also referred to as “reflected light” or “return light”. I do. In fluorescence contrast imaging or fluorescence contrast observation using illumination light as excitation light, fluorescence emitted by excitation light is included in “reflected light” or “return light”.

  A chin rest 10 is arranged at a position facing the lens barrel body 9. The chin rest 10 is provided with a chin rest part 10a and a forehead pad 10b for stably placing the face of the subject.

  An observation magnification operation knob 11 for changing the observation magnification is arranged on a side surface of the lens barrel body 9. Further, an imaging device 13 for imaging the eye E to be examined is connected to the lens barrel main body 9. The imaging device 13 includes an imaging element. The imaging element is a photoelectric conversion element that detects light and outputs an electric signal (image signal). The image signal is input to the computer 100. For example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is used as the imaging element. A mirror 12 that reflects an illumination light beam output from the illumination system 8 toward the subject's eye E is disposed below the illumination system 8.

[Configuration of optical system]
The configuration of the optical system of the slit lamp microscope 1 will be described with reference to FIG. The slit lamp microscope 1 has an observation system 6, an imaging system 7, and an illumination system 8. As described above, the observation system 6 includes the imaging system 7.

(Observation system)
The observation system 6 includes a pair of left and right optical systems. The left and right optical systems have substantially the same configuration. The examiner can observe the examinee's eye E with his / her binoculars using the left and right optical systems. FIG. 2 shows only one of the left and right optical systems of the observation system 6. Reference numeral O1 denotes an optical axis of the observation system 6 (observation optical axis) and an optical axis of the imaging system 7 (imaging optical axis).

  Each of the left and right optical systems of the observation system 6 includes an objective lens 31, a variable power optical system 32, a stop 33, a relay lens 35, a prism 36, and an eyepiece 37. The beam splitter 34 is provided on only one or both of the left and right optical systems. The eyepiece 37 is provided in the eyepiece 9a. Reference symbol P indicates an imaging position of light guided to the eyepiece 37. The symbol Ec indicates the cornea of the eye E, the symbol Ep indicates the iris, and the symbol Er indicates the fundus. The symbol Eo indicates the examiner's eye.

  The variable power optical system 32 includes a plurality of (for example, two) variable power lenses 32a and 32b. In this embodiment, a plurality of variable power lens groups that can be selectively inserted into the optical path of the observation system 6 are provided. These variable power lens groups are configured to give different magnifications. The variable power lens group arranged on the optical path of the observation system 6 is used as the variable power lenses 32a and 32b. Thereby, the magnification (angle of view) of the naked eye observation image and the captured image of the eye E can be changed. The change of the magnification, that is, the switching of the variable power lens group arranged on the optical path of the observation system 6 is performed by operating the observation magnification operation knob 11. Further, the magnification may be changed electrically using a switch (not shown) or the like.

  The beam splitter 34 splits the light traveling along the optical axis O1 into two. The light transmitted through the beam splitter 34 is guided to the examiner's eye Eo via the relay lens 35, the prism 36, and the eyepiece 37. The prism 36 includes two optical elements 36a and 36b, and translates the traveling direction of light upward in parallel. On the other hand, the light reflected by the beam splitter 34 is guided to the imaging system 7.

(Shooting system)
The imaging system 7 includes a relay lens 41, a mirror 42, and the imaging device 13. The imaging system 7 may further include a beam splitter 34. As described above, the imaging device 13 includes the imaging element 43. The imaging surface of the imaging element 43 is disposed at a position that is optically substantially conjugate with the imaging part (observation part) of the eye E (ie, the illumination position of the illumination light by the illumination system 8).

  The light reflected by the beam splitter 34 is guided to the imaging device 43 of the imaging device 13 via the relay lens 41 and the mirror 42. The image sensor 43 detects the reflected light and generates an image signal.

[Lighting system]
The illumination system 8 includes an illumination light generation unit 51 and a condenser lens 55. Reference symbol O2 indicates the optical axis of the illumination system 8 (illumination optical axis).

  The illumination light generator 51 is disposed at a position that is optically substantially conjugate with the imaging part of the eye E (ie, the illumination position of the illumination light by the illumination system 8). For example, the pupil position of the light source of the illuminating light generated by the illuminating light generating unit 51 is arranged at a position optically substantially conjugate to the imaging part of the eye E to be inspected.

  The illumination light generation unit 51 generates illumination light whose shape can be arbitrarily changed. The shape of the illumination light can be specified by the cross-sectional shape of the light beam and the shape of the projected image. The illumination light generation unit 51 converts the slit light, the direction of the slit light (the direction of the slit), the length and the shape of the slit light into the slit light that can be arbitrarily changed based on the control by the control unit 101. Generate as That is, the illumination light generation unit 51 can generate illumination light having a desired shape as slit light.

  The illumination light generation unit 51 includes, for example, a projector. The projector can output light of an illumination pattern that can be arbitrarily changed as illumination light. The illumination pattern represents the shape of the cross section of the light beam, the distribution of the amount of light and the distribution of the color in the cross section of the light beam. The projector outputs light having an illumination pattern set in advance based on control by the control unit 101. Thus, the projector can output, as slit light, illumination light whose slit width, direction of slit light, length and shape of slit light can be arbitrarily changed.

  The illumination pattern can be set by the user using, for example, an operation unit 104 described later. When the user specifies a shape pattern, an outer shape, a size, and the like using the operation unit 104, the control unit 101 specifies an illumination pattern based on the specified shape pattern and the like, and based on the specified illumination pattern. It is possible to control the projector.

  The projector may be a known projector using a digital micro mirror device. The projector may further include a light source. Examples of the light source include an LED (Light Emitting Diode) light source and a light source capable of outputting light of each color component of RGB. The projector may further include a relay optical system, a collimator lens, a projection lens, and the like.

  In addition, the projector may be one using LCoS (Liquid Crystal on Silicon) or MEMS (Micro Electro Mechanical Systems). Furthermore, the projector may use a liquid crystal display (LCD) (transmission type, reflection type). Since such a configuration is publicly known, detailed description is omitted. The projector may be any as long as it can output illumination light corresponding to an illumination pattern whose shape or the like can be arbitrarily changed.

  Note that the illumination light generation unit 51 may be provided with a plurality of light sources. In this case, the illumination light generation unit 51 can generate illumination light whose shape can be arbitrarily changed by controlling lighting and non-lighting of the plurality of light sources. Thus, the illumination light generation unit 51 can generate illumination light having a desired shape as slit light.

  The control unit 101 can control the light amount distribution of the illumination light within the light beam cross section by controlling the illumination light generation unit 51 based on the luminance distribution in the image of the eye E acquired by the imaging device 13. is there.

  The control unit 101 includes a specifying unit 60 and a light amount control unit 70. The specifying unit 60 specifies the correspondence between the illumination position of the illumination light generated by the illumination light generation unit 51 and the image of the eye E obtained using the imaging device 13. The light amount control unit 70 controls the light amount for each position in the light beam cross section of the illumination light by controlling the illumination light generation unit 51 based on the correspondence specified by the specifying unit 60. The specifying unit 60 and the light amount control unit 70 will be described later.

  The beam splitter 34 is an example of the “first optical path coupling member” according to this embodiment.

[Control system configuration]
The control system of the slit lamp microscope 1 will be described with reference to FIG. The control system of the slit lamp microscope 1 is configured around a control unit 101. Note that FIG. 3 shows only components that are particularly noticed in this embodiment, and other components are omitted.

(Control unit)
The control unit 101 controls each unit of the slit lamp microscope 1. For example, the control unit 101 performs control of the observation system 6, control of the imaging system 7, control of the illumination system 8, control of the data processing unit 110, and the like. Control of the observation system 6 includes control of the variable power optical system 32 and control of the stop 33. The control of the imaging system 7 includes control of the charge accumulation time of the image sensor 43, sensitivity, frame rate, and the like. The control of the illumination system 8 includes the control of the illumination light generation unit 51 and the like. The control of the data processing unit 110 includes control of an image generation process based on an image signal obtained by the image sensor 43 and control of an analysis process of the generated image. Further, the control unit 101 performs a process of reading data stored in the storage unit 102 and a process of writing data to the storage unit 102.

  As described above, the control unit 101 includes the specifying unit 60 and the light amount control unit 70.

<Specific part>
The specifying unit 60 specifies the correspondence between the position illuminated by the illumination light generated by the illumination light generation unit 51 and the illumination position by the illumination light that is actually applied to the eye E to be inspected. Specifically, the specifying unit 60 specifies the correspondence between the position in the light beam cross section (in-plane position) of the illumination light generated by the illumination light generation unit 51 and the illumination position of the illumination light in the image of the eye E. .

  The specifying unit 60 can specify the above-described correspondence using an in-plane pattern (landmark, position specifying pattern) represented by in-plane pattern information 102a described later. The in-plane pattern indicates the distribution of the intensity information of the illumination light in the illumination area by the illumination light. Specifically, the in-plane pattern is information in which intensity information is assigned to each of a plurality of partial regions obtained by dividing an illumination region. Each partial area is an area corresponding to one or more unit areas (one pixel, one digital micromirror, or the like). The in-plane pattern according to this embodiment is a binary pattern that indicates ON or OFF of illumination light for each partial area divided into a rectangular area.

<Light control unit>
The light amount control unit 70 controls the light amount for each position in the light beam cross section (for each unit area) by controlling the illumination light generation unit 51 based on the correspondence specified by the specifying unit 60. For example, the light amount control unit 70 determines the control information for each illumination position of the illumination light in the image based on the correspondence specified by the specifying unit 60. The light amount control unit 70 controls the light amount for each position in the light beam cross section by controlling the illumination light generation unit 51 based on the determined control information.

  The light amount control unit 70 can perform the above-described light amount control using the control information represented by the control table information 102b.

  FIG. 4 is an explanatory diagram of the control table information 102b according to this embodiment. In FIG. 4, the horizontal axis indicates the gradation value in the image of the eye E, and the vertical axis indicates control information for the illumination light. The gradation value indicates, for example, an average value of gradation values of a plurality of pixels in each partial region of the in-plane pattern. The tone value is a value in a range from a minimum value “0” to a maximum value “M” (M> 0, M is an integer). In this embodiment, the gradation values correspond to the luminance values. An area with a large tone value is a bright part, and an area with a small tone value is a dark part.

  “1 ×” on the vertical axis indicates control information for outputting illumination light having a predetermined reference light amount. “0.5 times” on the vertical axis indicates control information for outputting illumination light having a light amount 0.5 times the reference light amount. “1.5 times” on the vertical axis indicates control information for outputting illumination light having a light amount 1.5 times the reference light amount.

  The vertical axis may represent a control coefficient based on the currently applied illumination light amount. That is, “1 ×” on the vertical axis may indicate a control coefficient for outputting illumination light of the current illumination light amount as control information. In this case, “0.5 times” on the vertical axis indicates a control coefficient for outputting illumination light having a light amount 0.5 times the current illumination light amount. “1.5 times” on the vertical axis indicates a control coefficient for outputting illumination light of 1.5 times the current illumination light amount. In other words, a range exceeding “1” on the vertical axis indicates a control coefficient for increasing the current illumination light amount, and a range less than “1” on the vertical axis indicates a control coefficient for decreasing the current illumination light amount. .

  The control table information 102b is used to control the illumination light generation unit 51 so as to reduce the amount of illumination light with respect to the illumination position of an area (i.e., a bright portion) whose gradation value is equal to or greater than m1 (0 <m1 <M). Contains control information. Therefore, in the range where the gradation value is less than m1 and not more than M, control is performed so that the amount of illumination light decreases. The gradation value m1 can be set by the user using the operation unit 104.

  Further, the control table information 102b controls the illumination light generation unit 51 so as to increase the amount of illumination light with respect to the illumination position of an area (that is, a dark part) whose gradation value is equal to or less than m2 (0 <m2 ≦ m1 <M). Control information. Therefore, in the range where the gradation value is equal to or more than 0 and less than m2, control is performed so that the amount of illumination light increases. The gradation value m2 can be set by the user using the operation unit 104.

  In FIG. 4, the gradation value m1 is an example of the “first threshold value of the luminance value” according to the embodiment, and the gradation value m2 is an example of the “second threshold value of the luminance value” according to the embodiment.

  The control unit 101 includes hardware such as a microprocessor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a hard disk drive. A control program is stored in the hard disk drive in advance. The operation of the control unit 101 is realized by cooperation between the control program and the hardware.

  The control unit 101 is arranged in the apparatus main body (for example, in the base 4) of the slit lamp microscope 1 or the computer 100.

[Data processing unit]
The data processing unit 110 generates an image based on the image signal obtained by the image sensor 43. Since the image generation process by the data processing unit 110 is a known process, a detailed description is omitted. The data processing unit 110 may be configured to perform a predetermined analysis process on an image generated based on the image signal. The data processing unit 110 is arranged in the apparatus main body of the slit lamp microscope 1 and the computer 100 together with the control unit 101.

[Storage unit]
The storage unit 102 stores various types of information. In particular, the storage unit 102 stores in-plane pattern information 102a and control table information 102b in advance.

  The in-plane pattern information 102a includes information for specifying one or more in-plane patterns. The in-plane pattern information 102a is stored in the storage unit 102 in advance. The user can set the in-plane pattern information 102 a by using the operation unit 104.

  The control table information 102b includes one or more pieces of control information for controlling the light amount control unit 70. The control table information 102b is stored in the storage unit 102 in advance. The control table information 102b can be set by the user by using the operation unit 104.

(Display)
The display unit 103 displays various information under the control of the control unit 101. The display unit 103 includes an arbitrary display device such as a flat panel display such as an LCD and a CRT display. The display unit 103 may be provided in the apparatus main body of the slit lamp microscope 1 or may be provided in the computer 100.

(Operation unit)
The operation unit 104 includes an operation device and an input device. The operation unit 104 includes buttons and switches (for example, the operation handle 5 and the like) provided on the apparatus main body, a mouse and a keyboard of the computer 100, and the like. Also, any operation device or input device such as a trackball, a dedicated operation panel, switches, buttons, and dials can be used.

  Although the display unit 103 and the operation unit 104 are separately illustrated in FIG. 3, they may be integrally configured. As a specific example, a touch panel type LCD can be used.

[Regarding control by specifying unit 60 and light amount control unit 70]
FIG. 5 is a diagram illustrating the operation of the specifying unit 60 and the light amount control unit 70. In FIG. 5, for convenience of explanation, coordinate information for indicating the coordinate position of the partial area obtained by dividing the illumination area of the illumination light is illustrated. Here, it is assumed that the plurality of partial areas are arranged at coordinate positions (1, 1) to (8, 6). Hereinafter, for convenience of explanation, a case will be described in which an in-plane pattern is applied to illumination light that illuminates the fundus Er of the eye E, but the same applies to a case where an in-plane pattern is applied to slit light.

  The reflectance of the illuminating light with respect to the part of the eye E varies depending on the part. For example, as shown in FIG. 5, in the fundus Er, the reflectance of the illumination light to the optic disc P1 where the optic disc is located is high, and the reflectance of the illumination light to the retina P2 and the illumination to the macula P3 where the fovea is located. Light reflectance is low. Therefore, when the subject's eye E is illuminated with illumination light having a uniform light amount distribution, overexposure occurs in the optic papilla P1 or blackout occurs in the retina P2 and the macula P3, and an image suitable for observation can be obtained. It may not be possible. Therefore, the control unit 101 controls the light amount distribution of the illumination light in the specifying unit 60 and the light amount control unit 70 in consideration of the reflectance of the illumination light to the imaging region of the eye E as described below.

  First, the light quantity control unit 70 illuminates the eye E with the illumination light L1 having a uniform light quantity in the light beam cross section. For example, the light amount control unit 70 controls the light amount for each light beam cross-sectional position by controlling the illumination light generation unit 51 using an in-plane pattern that makes the light amount uniform in the light beam cross section. Thereby, the illumination light generation unit 51 illuminates the area corresponding to the partial area at the coordinate positions (1, 1) to (8, 6) with the illumination light L1 having a uniform light amount. By imaging the eye E using the imaging device 13, an image G1 of the eye E illuminated with the illumination light L1 having a uniform light amount is obtained.

  Next, the light quantity control unit 70 controls the light quantity for each position in the light beam cross section by controlling the illumination light generation unit 51 using, for example, an in-plane pattern as shown in FIG. In the in-plane pattern shown in FIG. 5, a partial area (white area) not illuminated by illumination light and a partial area (black area) illuminated by illumination light having a predetermined reference light amount are specified. Thereby, the illumination light generation unit 51 illuminates the eye E with the illumination light L2 having the light amount distribution as shown in FIG. By photographing the eye E using the imaging device 13, an image G2 of the eye E illuminated with the illumination light L2 to which the in-plane pattern as shown in FIG. 5 is applied is obtained.

  The image G1 is an example of a “first image” according to the embodiment, and the image G2 is an example of a “second image” according to the embodiment.

  It is desirable that the imaging conditions and the imaging region of the image G1 substantially match the imaging conditions and the imaging region of the image G2. That is, it is desirable that the image G2 is an image acquired for the same imaging region using illumination light having the same light amount distribution in the light beam cross section as when the image G1 was acquired.

  The specifying unit 60 specifies the above-described correspondence based on the image G1 obtained using the illumination light L1 and the image G2 obtained using the illumination light L2 having a predetermined in-plane pattern. Since the difference between the image G1 and the image G2 substantially corresponds to the in-plane pattern applied to the illumination light L2, the identifying unit 60 calculates the difference between the image G1 and the image G2, and determines the obtained difference and the above-described in-plane pattern. By specifying the positional relationship with the pattern, it is possible to specify the correspondence described above. Thereby, when analyzing the image of the eye E obtained by using the imaging device 13 to specify the position of the characteristic portion in the image, and specifying the above-described correspondence based on the position of the specified characteristic portion The processing load can be greatly reduced as compared with.

  Note that, in order to identify the above-described correspondence, a case will be described in which the imaging conditions and the imaging parts are matched for the images G1 and G2. However, if the correspondence can be identified, the images G1 and G2 It is desirable to match at least only the imaging site.

  As shown in FIG. 5, the in-plane pattern applied to the illumination light L2 includes at least a spatially irregular pattern (non-uniform pattern, non-uniform pattern). This makes it possible to easily and accurately specify the positional relationship between the difference between the image G1 and the image G2 and the in-plane pattern applied to the illumination light L2. The in-plane pattern may be an irregular pattern in time.

  The control unit 101 can control the illumination light generation unit 51 so as to illuminate the eye E with illumination light having an in-plane pattern for at least a predetermined period. The predetermined period is a period in which the subject cannot sense. The user can set the predetermined period by using the operation unit 104. Thus, the above-described correspondence can be specified without the subject sensing the in-plane pattern. In this case, the control unit 101 can acquire an image of the eye E illuminated with the illumination light by controlling the imaging device 13 in synchronization with the illumination timing of the illumination light to the eye E.

  Further, the illumination light including the in-plane pattern may be invisible light. At least the in-plane pattern may be projected onto the eye E by invisible light (for example, infrared light). Also in this case, the above-described correspondence can be specified without the subject sensing the in-plane pattern. In this case, the imaging device 13 is configured to include an imaging element capable of detecting the return light from the invisible light.

  The light quantity control unit 70 determines the control information for each partial area from the control table information 102b as shown in FIG. 4 based on the correspondence specified by the specifying unit 60. The light amount control unit 70 controls the light amount for each position in the light beam cross section by controlling the illumination light generation unit 51 based on the determined control information.

  For example, in the region near the coordinate position (2, 4) corresponding to the optic papilla P1, the reflectance of the illumination light is high and whiteout may occur. In this embodiment, since the control information is determined for each partial area from the control table information 102b as shown in FIG. 4, the light amount is reduced in the area near the coordinate position (2, 4) as shown in FIG. The illumination light generator 51 is controlled.

  On the other hand, in a region near the coordinate position (5, 4) corresponding to the macula P3, the reflectance of the illumination light is low, and blackening may occur. In this embodiment, since the control information is determined for each partial area from the control table information 102b as shown in FIG. 4, the light amount is increased in the area near the coordinate position (5, 4) as shown in FIG. The illumination light generator 51 is controlled. By photographing the eye E using the imaging device 13, an image G3 of the eye E suitable for observation is obtained while suppressing the occurrence of overexposure and crushed black. By controlling the light amount using the image G3 instead of the image G1, a live image suitable for observation can be obtained. In this case, the image G3 is an example of the “first image” according to the embodiment.

[Operation example]
The operation of the slit lamp microscope 1 will be described.

  FIG. 6 shows a flowchart of an operation example of the slit lamp microscope 1.

(S1)
First, the control unit 101 reads out the in-plane pattern information 102a stored in the storage unit 102. The light amount control unit 70 specifies an in-plane pattern such that the light amount becomes uniform in the light beam cross section from the in-plane pattern information 102a read from the storage unit 102. The light amount control unit 70 controls the light amount for each position in the light beam cross section by controlling the illumination light generation unit 51 using the specified in-plane pattern. Thereby, the illumination light generation unit 51 illuminates the area corresponding to the partial area at the coordinate positions (1, 1) to (8, 6) with the illumination light L1 having a uniform light amount. Note that a plurality of partial regions may be illuminated with the illumination light L1 having a uniform light amount without applying the in-plane pattern.

(S2)
The control unit 101 controls the imaging device 13 to photograph the subject's eye E. Thereby, an image G1 of the eye E illuminated with the illumination light having a uniform light amount in S1 is obtained.

(S3)
Next, the light quantity control unit 70 specifies a predetermined in-plane pattern from the in-plane pattern information 102a read from the storage unit 102 in S1. In the in-plane pattern, a partial area not illuminated with the illumination light and a partial area illuminated with the illumination light of a predetermined reference light amount are specified. For example, in FIG. 5, the area corresponding to the partial area at the coordinate position (2, 1) is not illuminated, and the area corresponding to the partial area at the coordinate position (3, 1) is illuminated with the reference amount of illumination light.

  The light amount control unit 70 controls the light amount for each position in the light beam cross section by controlling the illumination light generation unit 51 using the specified in-plane pattern. Thereby, the illumination light generation unit 51 illuminates the eye E with the illumination light L2 having the light amount distribution as shown in FIG.

(S4)
The control unit 101 controls the imaging device 13 to photograph the subject's eye E. Thereby, the image G2 of the eye E illuminated with the illumination light having the light amount distribution corresponding to the in-plane pattern in S3 is obtained.

(S5)
The specifying unit 60 specifies the above-described correspondence based on the image G1 obtained using the illumination light L1 and the image G2 obtained using the illumination light L2 having a predetermined in-plane pattern.

(S6)
The light quantity control unit 70 determines the control information for each partial area from the control table information 102b as shown in FIG. 4 based on the correspondence specified by the specifying unit 60.

(S7)
The light amount control unit 70 controls the light amount for each position in the light beam cross section by controlling the illumination light generation unit 51 based on the control information determined in S6.

(S8)
The control unit 101 controls the imaging device 13 to photograph the subject's eye E. As a result, the image G3 of the eye E to be observed suitable for observation is obtained while suppressing occurrence of overexposure and crushed black due to being illuminated with the illumination light whose light amount has been controlled in S7.

(S9)
The control unit 101 determines whether or not to terminate the operation of the slit lamp microscope 1. For example, the end of the operation is instructed by the user using the operation unit 104. The control unit 101 can determine whether or not to end the operation of the slit lamp microscope 1 based on the content of a user operation on the operation unit 104. When it is determined that the operation of the slit lamp microscope 1 is not terminated (S9: N), the operation of the slit lamp microscope 1 proceeds to S3. Therefore, in subsequent S5, the specifying unit 60 can specify the above-described correspondence using the image G2 obtained in S4 and the image G3 obtained in S8. Thereby, the control of the light amount for the live image of the eye E can be executed in real time.

  When it is determined that the operation of the slit lamp microscope 1 ends (S9: Y), the operation of the slit lamp microscope 1 ends (end).

  In FIG. 6, S2, S4, and S8 are examples of the “acquisition step” according to the embodiment. S5 is an example of the “specific step” according to the embodiment. S7 is an example of a “control step” according to the embodiment.

[effect]
The effects of the ophthalmologic photographing apparatus according to this embodiment will be described.

  The ophthalmologic photographing apparatus (for example, the slit lamp microscope 1) according to the embodiment includes an illumination system (for example, the illumination system 8), a photography system (for example, the photography system 7), and a control unit (for example, the control unit 101). including. The illumination system includes an illumination light generation unit (for example, the illumination light generation unit 51). The illumination light generator generates illumination light. The illumination system illuminates the subject's eye (for example, the subject's eye E) with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to an imaging device (for example, the imaging device 13). The control unit controls the illumination light generation unit based on a luminance distribution in an image acquired by the imaging device.

  According to such a configuration, the illumination light control unit is controlled based on the luminance distribution of the image of the subject's eye acquired by the imaging device. The subject's eye can be illuminated with the illumination light. Thereby, by illuminating the eye with the illumination light having the light amount distribution changed in consideration of the difference in the reflection of the illumination light according to the imaging region of the eye to be inspected, an image of the eye to be inspected suitable for observation is obtained. It becomes possible.

  The control unit may include a specifying unit (for example, the specifying unit 60) and a light amount control unit (for example, the light amount control unit 70). The specifying unit specifies a correspondence relationship between an in-plane position of the illumination light generated by the illumination light generation unit (for example, a position in a light beam cross section) and an illumination position of the illumination light in the image. The light amount control unit determines the control information for each illumination position based on the correspondence specified by the specifying unit, and controls the illumination light generation unit based on the determined control information to thereby control the light amount for each in-plane position. Control.

  According to such a configuration, by controlling the amount of light for each in-plane position of the illumination light based on the above-described correspondence relationship, the optimum light intensity corresponding to the part of the eye to be inspected is obtained regardless of the positions of the illumination system and the imaging system. The eye to be examined can be illuminated simultaneously with a large amount of light.

  Further, the light amount control unit may control the light amount so as to reduce the light amount of the illuminating light with respect to the illuminating position of the bright part whose luminance value is equal to or more than the first threshold in the image.

  According to such a configuration, the amount of illumination light at the illumination position corresponding to the bright part of the image of the eye to be inspected is reduced, so that the dynamic range of the imaging system can be expanded.

  Further, the light amount control unit may control the light amount so as to increase the light amount of the illumination light with respect to the illumination position of the dark part whose luminance value is equal to or less than the second threshold value in the image.

  According to such a configuration, the amount of illumination light at the illumination position corresponding to the dark part of the image of the eye to be inspected is increased, so that the dynamic range of the imaging system can be expanded.

  In addition, the specifying unit may be configured to include a first image (for example, images G1 and G3) acquired using illumination light and a second image (for example, image G2) acquired using illumination light having a predetermined in-plane pattern. ), The correspondence may be specified.

  According to such a configuration, since the above-described correspondence is specified using the in-plane pattern, the processing load is significantly increased as compared with the case where the correspondence is specified by analyzing the image of the eye to be inspected. Can be reduced.

  Further, the in-plane pattern may include at least a spatially irregular pattern.

  According to such a configuration, at least a spatially irregular pattern is used as the in-plane pattern, so that the correspondence can be specified with high accuracy. For example, the difference between the image of the subject's eye illuminated with the illumination light to which the in-plane pattern is applied and the image of the subject's eye illuminated with illumination light to which the in-plane pattern is not applied substantially corresponds to the in-plane pattern. . In the specification of the positional relationship between the difference and the in-plane pattern, there is a possibility that a regular part cannot be uniquely specified, but an irregular part can be uniquely specified. Therefore, by using at least a spatially irregular pattern as the in-plane pattern, the above-described correspondence can be specified with high accuracy.

  The control unit may control the illumination light generation unit to illuminate the eye to be inspected with the illumination light having the in-plane pattern for at least a predetermined period.

  According to such a configuration, the subject's eye is illuminated with the illumination light having the in-plane pattern for at least the predetermined period, so that the above-described correspondence relationship can be specified without putting a burden on the subject. Will be possible.

  The illumination light including the in-plane pattern may be invisible light.

  According to such a configuration, since the subject's eye is illuminated with invisible light as illumination light having an in-plane pattern, the above-described correspondence can be specified without putting a burden on the subject. Become.

  Further, the illumination light generation unit may generate illumination light whose shape can be arbitrarily changed.

  According to such a configuration, illumination light that can be changed to an arbitrary shape can be used as slit light, and the function of the slit lamp microscope having the above-described effects can be realized.

  Further, the illumination light generation unit may include a projector capable of outputting light having an illumination pattern that can be arbitrarily changed.

  According to such a configuration, the illumination light is output by the projector, so that the configuration and control of the ophthalmologic photographing apparatus can be simplified.

  Further, the ophthalmologic photographing apparatus according to the embodiment may include an observation system (for example, the observation system 6) and a first optical path coupling member (for example, the beam splitter 34). The observation system includes an eyepiece (eg, eyepiece 37). The observation system guides the return light of the illumination light from the eye to be examined to the eyepiece. The first optical path coupling member couples the optical path of the imaging system to the optical path of the observation system.

  According to such a configuration, the optical path of the imaging system and the optical path of the observation system can be disposed substantially coaxially, so that the eye to be observed that can be observed by the eyepiece and the image of the eye to be inspected acquired by the imaging device substantially match each other. Can be done.

  Further, the control method of the ophthalmologic photographing apparatus (for example, the slit lamp microscope 1) according to the embodiment includes an acquisition step (for example, S2, S4, S8) and a control step (for example, S7). The ophthalmologic imaging apparatus includes an illumination system (for example, illumination system 8) and an imaging system (for example, imaging system 7). The illumination system includes an illumination light generation unit (for example, the illumination light generation unit 51). The illumination light generator generates illumination light. The illumination system illuminates the subject's eye (for example, the subject's eye E) with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to an imaging device (for example, the imaging device 13). In the obtaining step, an image of the subject's eye is obtained by the imaging device. In the control step, the illumination light generation unit is controlled based on the luminance distribution in the acquired image.

[Second embodiment]
In the slit lamp microscope according to the first embodiment, the case where the optical path of the imaging system is coupled to the optical path of the observation system has been described, but the slit lamp microscope according to the embodiment is not limited to this. In the slit lamp microscope according to the second embodiment, the optical path of the imaging system is coupled to the optical path of the illumination system.

  The configuration of the slit lamp microscope according to the second embodiment is almost the same as that of the first embodiment. Hereinafter, the second embodiment will be described focusing on differences from the first embodiment.

  FIG. 7 shows a configuration example of an optical system of the slit lamp microscope according to this embodiment. 7, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description will be appropriately omitted.

  The configuration of the slit lamp microscope 1A according to this embodiment differs from the configuration of the slit lamp microscope 1 shown in FIG. 2 in that the optical path of the imaging system is coupled to the optical path of the illumination system. The slit lamp microscope 1A includes an observation system 6A, an imaging system 7A, and an illumination system 8A.

  The observation system 6A includes a pair of left and right optical systems, similar to the observation system 6. Each of the left and right optical systems of the observation system 6A has an objective lens 31, a variable power optical system 32, a stop 33, a relay lens 35, a prism 36, and an eyepiece 37. FIG. 7 shows only one of the left and right optical systems of the observation system 6A. Symbol O1A is the optical axis (observation optical axis) of the observation system 6A. The observation system 6A is arranged inside the lens barrel main body 9A.

  The imaging system 7A includes a relay lens 41 and the imaging device 13 as in the imaging system 7. The imaging system 7A may further include a beam splitter 34A. Symbol O2A indicates the optical axis of the imaging system 7A (imaging optical axis) and the optical axis of the illumination system 8A (illumination optical axis).

  The beam splitter 34A splits the light traveling along the optical axis O2A into two. The light reflected by the beam splitter 34A is guided to the image sensor 43 of the image pickup device 13 via the relay lens 41. The image sensor 43 detects the reflected light and generates an image signal. A dichroic mirror or a half mirror may be provided instead of the beam splitter 34A.

  The illumination system 8A includes an illumination light generation unit 51 and a condenser lens 55. The illumination system 8A may further include a beam splitter 34A.

  The operation of the slit lamp microscope 1A according to this embodiment is the same as that of the first embodiment, and thus the description is omitted.

  The beam splitter 34A is an example of the “second optical path coupling member” according to the embodiment.

[effect]
The effects of the ophthalmologic photographing apparatus according to this embodiment will be described.

  The ophthalmologic photographing apparatus according to the embodiment (for example, the slit lamp microscope 1A) includes a second optical path coupling member (for example, the beam splitter 34A). The second optical path coupling member couples the optical path of the imaging system (for example, the imaging system 7A) to the optical path of the illumination system (for example, the illumination system 8A).

  According to such a configuration, since the optical path of the imaging system and the optical path of the illumination system can be arranged substantially coaxially, the correspondence between the in-plane position of the illumination light and the illumination position of the illumination light in the image of the subject's eye can be accurately determined. It can be specified. Further, since the positions of the photographing system and the illumination system can be fixed, the correspondence becomes constant, and the process of specifying the correspondence becomes unnecessary.

[Third embodiment]
In the slit lamp microscope according to the first embodiment or the second embodiment, a case has been described in which the light amount distribution of the illumination light is controlled based on the luminance distribution of the image of the eye to be inspected. It is not limited to this. In the third embodiment, a region of interest in an image of an eye to be examined is specified, and the amount of illumination light for the specified region of interest is controlled.

  The configuration of the slit lamp microscope according to the third embodiment is the same as that of the first embodiment or the second embodiment. Hereinafter, the second embodiment will be described focusing on differences from the first embodiment.

  The control unit according to this embodiment specifies a region of interest by analyzing an image of the eye E obtained by using the imaging device 13 in the specifying unit. The attention area is determined in advance. The attention area can be set by the user using the operation unit 104. The region of interest includes a region corresponding to the pupil, a region corresponding to the cornea, a region corresponding to the optic disc, a region corresponding to the retina, a region corresponding to the macula, and the like.

  For example, the specifying unit can specify the attention area based on the position information of one or more characteristic parts set in advance for the image of the eye E. The characteristic portions include an iris, a running state of blood vessels, a macula, and the like. The position information of the characteristic portion may be determined in advance, or may be set by the user using the operation unit 104. Further, the specifying unit may specify the attention area by searching for an image of the eye E by pattern matching based on a preset shape pattern.

  The control unit according to this embodiment controls the light amount of the illumination light corresponding to at least the attention area specified by the specifying unit in the light flux cross-sectional position (in-plane position) in the light amount control unit.

  For example, the light amount control unit controls the light amount so as to reduce the light amount of the illumination light applied to the attention area. Accordingly, when the region of interest specified by the specifying unit is a region corresponding to the pupil, the amount of illumination light incident on the pupil can be reduced. Therefore, the subject does not feel uncomfortable. Further, it is possible to avoid a situation in which observation cannot be continued due to miosis.

  In addition, when the region of interest specified by the specifying unit is a region corresponding to the cornea or the optic disc, it is possible to remove artifacts that are unnecessary for observation and are caused by reflection of illumination light by the cornea or the optic disc.

  Further, the light quantity control unit may control the light quantity so as to increase the light quantity of the illumination light applied to the attention area. Thus, when the region of interest specified by the specifying unit is a region corresponding to the retina or the macula, the amount of illumination light applied to the retina or the macula can be increased. Therefore, it is possible to prevent the occurrence of blackening of the image and to obtain an image suitable for observation.

[effect]
The effects of the ophthalmologic photographing apparatus according to this embodiment will be described.

  In the ophthalmologic imaging apparatus according to the embodiment, the control unit may include a specifying unit and a light amount control unit. The specifying unit specifies a region of interest by analyzing the image. The light quantity control unit controls the light quantity of at least the in-plane position of the illumination light corresponding to the attention area.

  According to such a configuration, the amount of illumination light with respect to the attention area specified in the image of the eye to be inspected is controlled, so that it is possible to correspond to the site of the eye to be inspected regardless of the positions of the illumination system and the imaging system. The subject's eye can be illuminated at the same time with the optimal amount of light.

  Further, the region of interest may be a region in an image corresponding to the pupil, cornea, or optic disc. The light amount control unit may control the light amount so as to reduce the light amount of the illumination light applied to the attention area.

  According to such a configuration, the subject does not feel uncomfortable. Further, it is possible to avoid a situation in which observation cannot be continued due to miosis. In addition, it is possible to remove artifacts caused by reflection of illumination light unnecessary for observation.

  The embodiments described above are merely examples for carrying out the present invention. A person who intends to implement the present invention can make arbitrary modifications, omissions, additions, substitutions, and the like within the scope of the present invention.

1, 1A Slit lamp microscope 6, 6A Observation system 7, 7A Imaging system 8, 8A Illumination system 12, 42 Mirror 13 Imaging device 31 Objective lens 32 Zoom optical system 33 Aperture 35, 41 Relay lens 36 Prism 37 Eyepiece lens 34 , 34A Beam splitter 43 Image sensor 51 Illumination light generator 60 Identifier 70 Light controller 100 Computer 101 Controller 102 Storage 102a In-plane pattern information 102b Control table information 103 Display 104 Operation unit 110 Data processing unit E Eye to be examined

Claims (6)

An illumination system that includes an illumination light generation unit that generates illumination light, and illuminates the subject's eye with the illumination light.
An imaging system that guides return light of the illumination light from the eye to be examined to an imaging device;
By analyzing an image acquired by the imaging device, a region of interest in the image is specified, and the amount of in-plane light of illumination light corresponding to the region of interest is controlled according to a part included in the region of interest. A control unit to
Ophthalmic imaging apparatus including: The ophthalmologic imaging apparatus according to claim 1, wherein the illumination light generation unit generates illumination light whose shape can be arbitrarily changed. The ophthalmologic imaging apparatus according to claim 1, wherein the illumination light generation unit includes a projector that can output light having an illumination pattern that can be arbitrarily changed. An observation system that includes an eyepiece and guides return light of the illumination light from the eye to be examined to the eyepiece,
The ophthalmologic imaging apparatus according to any one of claims 1 to 3, further comprising: a first optical path coupling member that couples an optical path of the imaging system to an optical path of the observation system. The ophthalmologic imaging apparatus according to any one of claims 1 to 3, further comprising a second optical path coupling member that couples an optical path of the imaging system to an optical path of the illumination system. Control of an ophthalmologic imaging apparatus including: an illumination system that includes an illumination light generation unit that generates illumination light and illuminates an eye to be examined with the illumination light; and an imaging system that guides return light of the illumination light from the eye to be examined to an imaging apparatus. The method
An acquisition step of acquiring an image of the eye to be examined by the imaging device,
A control step of identifying a region of interest in the image by analyzing the acquired image, and controlling a light amount of an in-plane position of illumination light corresponding to the region of interest in accordance with a portion included in the region of interest When,
A control method for an ophthalmologic photographing apparatus including:

Images