JP6490472B2 - Ophthalmic imaging apparatus and control method thereof - Google Patents

Description

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

  The ophthalmologic photographing apparatus is used for acquiring 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 is generally configured to include an illumination system and a photographing system. The illumination system illuminates the eye to be examined with illumination light. The imaging system guides the return light of the illumination light from the eye to be examined to the imaging device. The ophthalmologic imaging apparatus acquires an image of the eye to be examined using the imaging apparatus.

JP 2014-188339 A

  In a conventional ophthalmologic photographing apparatus, the illumination system illuminates the subject's eye with illumination light having a uniform amount of light (that is, spatially uniform illumination light) within the cross section of the light beam, regardless of the region of the subject's eye. As a result, whiteout or blackout may occur due to the difference in reflectance for each part, and an image suitable for observation may not be acquired.

  In addition, since the eye to be examined is illuminated with illumination light having a uniform amount of light within the cross section of the light beam, the subject may feel dazzled when intense light is incident on the pupil, which may cause discomfort to the subject. Furthermore, there are cases where it is impossible to continue photographing and observing the subject's eye due to miosis.

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

The ophthalmologic photographing apparatus according to the embodiment includes an illumination system, a photographing system, and a control unit. The illumination system includes an illumination light generation unit. The illumination light generation unit generates illumination light. The illumination system illuminates the eye to be examined with illumination light. The imaging system guides the return light of the illumination light from the eye to be examined to the imaging device. The control unit controls the illumination light generation unit based on the luminance distribution in the image acquired by the imaging device. The control unit is configured to identify a correspondence between the in-plane position of the illumination light generated by the illumination light generation unit and the illumination position of the illumination light in the image, and an illumination position based on the correspondence specified by the specification unit. And a light amount control unit that controls the light amount for each in-plane position by determining the control information for each and controlling the illumination light generation unit based on the determined control information.
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 generation unit generates illumination light. The illumination system illuminates the eye to be examined with illumination light. The imaging system guides the return light of the illumination light from the eye to be examined to the imaging device. In the acquisition step, an image of the eye to be examined is acquired by the imaging device. In the control step, the illumination light generation unit is controlled based on the luminance distribution in the acquired image. The control step identifies a correspondence relationship between the in-plane position of the illumination light generated by the illumination light generation unit and the illumination position of the illumination light in the image, and determines control information for each illumination position based on the identified correspondence relationship Then, the amount of light is controlled for each in-plane position by controlling the illumination light generation unit based on the determined control information.

  According to the present invention, it is possible to provide a new technique of an ophthalmologic photographing apparatus for acquiring an 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. It is the schematic showing an example of a structure of the optical system of the ophthalmologic imaging device which concerns on embodiment. It is the schematic showing an example of the structure of the control system of the ophthalmologic imaging device which concerns on embodiment. It is operation | movement explanatory drawing of the ophthalmologic imaging device which concerns on embodiment. It is operation | movement explanatory drawing of the ophthalmologic imaging device which concerns on embodiment. It is a flowchart showing an example of operation | movement of the ophthalmologic imaging device which concerns on embodiment. It is the schematic showing an example of a structure of the optical system of the ophthalmologic imaging device which concerns on 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. In addition, it is possible to use suitably the description content of the literature described in this specification as the content of the following embodiment.

  Hereinafter, a slit lamp microscope will be described as an example of the ophthalmologic photographing apparatus according to the embodiment, but the ophthalmic photographing apparatus according to the embodiment is not limited thereto. In addition to the slit lamp microscope, the ophthalmologic photographing apparatus to which the present invention can be applied includes a fundus camera, a scanning laser opthalmoscope (SLO), a laser photocoagulator, and the like. Further, the imaging region by the ophthalmologic imaging apparatus according to the embodiment may be an arbitrary region of the eye to be examined. For example, in the anterior eye portion, it may be a cornea, a vitreous body, a crystalline lens, a ciliary body, a corner, or the like. However, in the posterior eye portion, it may be a retina, a choroid, or a vitreous body. Further, the imaging region may be a peripheral region of the eye such as a eyelid or an 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. The horizontal direction orthogonal to the front direction is the left-right direction. Furthermore, the direction orthogonal to both the front-rear direction and the left-right direction is defined as the up-down 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. Instead of providing the computer 100 separately from the microscope main body (housing for storing the optical system or the like), a configuration in which the same computer is mounted on the microscope main body can be applied.

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

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

  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 support arm 16 and 17 may be comprised so that it may be rotated by an electrical mechanism. In that case, an actuator for generating a driving force for rotating 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 constituted by, for example, a combination of gears, a rack and pinion, or the like.

  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 in the left-right direction 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 in the vertical direction. That is, you may be comprised so that the elevation angle and depression angle of illumination light can be changed.

  The observation system 6 has a pair of left and right optical systems that guide reflected light of illumination light from the eye E. Further, the observation system 6 is configured to include an imaging system. This optical system is housed in the barrel main body 9. The optical path of the imaging system is coupled to the optical path of the observation system 6 in the barrel main body 9. The end of the lens barrel body 9 is an eyepiece 9a. The examiner looks at the eye E with the naked eye by looking into the eyepiece 9a. As described above, the lens barrel body 9 can be rotated in the left-right direction by rotating the support arm 16. Thereby, the direction of the observation system 6 with respect to the eye E can be changed. 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 kinds of light are referred to as “reflected light” or “return light”. To do. Further, in fluorescence contrast imaging and 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 disposed at a position facing the lens barrel body 9. The chin rest 10 is provided with a chin rest 10a and a forehead rest 10b for stably arranging the face of the subject.

  An observation magnification operation knob 11 for changing the observation magnification is disposed on the side surface of the barrel main body 9. Further, an imaging device 13 for photographing the eye E is connected to the 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 electrical signal (image signal). The image signal is input to the computer 100. As the imaging element, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is used. A mirror 12 that reflects the illumination light beam output from the illumination system 8 toward the 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 includes an observation system 6, a photographing system 7, and an illumination system 8. As described above, the observation system 6 includes the photographing 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 eye E with binoculars using the left and right optical systems. In FIG. 2, only one of the left and right optical systems of the observation system 6 is shown. Reference numeral O1 denotes the optical axis of the observation system 6 (observation optical axis) and the 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 magnification optical system 32, a diaphragm 33, a relay lens 35, a prism 36, and an eyepiece lens 37. The beam splitter 34 is provided in only one or both of the left and right optical systems. The eyepiece lens 37 is provided in the eyepiece 9a. A symbol P indicates an imaging position of light guided to the eyepiece lens 37. Reference sign Ec represents the cornea of the eye E, reference sign Ep represents the iris, and reference sign Er represents the fundus. Reference Eo indicates the examiner's eye.

  The variable magnification optical system 32 includes a plurality of (for example, two) variable magnification 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. A variable power lens group disposed in the optical path of the observation system 6 is used as the variable power lenses 32a and 32b. Thereby, the magnification (field angle) of the naked eye observation image of the eye E and the captured image can be changed. Changing the magnification, that is, switching the zoom lens group disposed in the optical path of the observation system 6 is performed by operating the observation magnification operation knob 11. Moreover, you may comprise so that a magnification may be electrically changed using a switch etc. which are not illustrated.

  The beam splitter 34 divides 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 through the relay lens 35, the prism 36 and the eyepiece lens 37. The prism 36 includes two optical elements 36a and 36b, and translates the traveling direction of light upward. 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 an 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 conjugate with an imaging region (observation region) of the eye E (that is, an illumination position of illumination light by the illumination system 8).

  The light reflected by the beam splitter 34 is guided to the imaging element 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 an optical axis (illumination optical axis) of the illumination system 8.

  The illumination light generation unit 51 is disposed at a position that is optically conjugate with the imaging region of the eye E (that is, the illumination position of illumination light by the illumination system 8). For example, the pupil position of the light source of the illumination light generated in the illumination light generation unit 51 is disposed at a position that is optically conjugate with the imaging region of the eye E.

  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 or the shape of the projected image. Based on the control by the control unit 101, the illumination light generation unit 51 converts the slit light, the illumination light whose slit width, the direction of the slit light (the direction of the slit), the length and the shape of the slit light can be arbitrarily changed, into the slit light. 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 in the cross section of the light beam, the distribution of colors, and the like. The projector outputs light having a preset illumination pattern based on control by the control unit 101. Thereby, the projector can output illumination light whose slit width, direction of slit light, length of slit light, and shape can be arbitrarily changed as slit light.

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

  The projector may be a known projector using a digital micromirror 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.

  Further, 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 known, detailed description thereof is omitted. The projector may be any projector that can output illumination light corresponding to an illumination pattern whose shape can be arbitrarily changed.

  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. Thereby, the illumination light generation part 51 can generate | occur | produce the illumination light of a desired shape as slit light.

  The control unit 101 can control the light quantity 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 generating unit 51 and the image of the eye E to be examined acquired using the imaging device 13. The light amount control unit 70 controls the illumination light generation unit 51 based on the correspondence specified by the specifying unit 60 to control the light amount for each position in the light beam cross section of the illumination light. The specifying unit 60 and the light amount control unit 70 will be described later.

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

[Control system configuration]
A 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 the control unit 101. Note that FIG. 3 shows only components that are particularly focused on in this embodiment, and other components are omitted.

(Control part)
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 magnification optical system 32 and control of the aperture 33. Control of the imaging system 7 includes control of charge accumulation time, sensitivity, frame rate, etc. of the image sensor 43. Control of the illumination system 8 includes control of the illumination light generation unit 51 and the like. Control of the data processing unit 110 includes control of image generation processing based on an image signal obtained by the image sensor 43, control of analysis processing of the generated image, and the like. In addition, 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 generating unit 51 and the illumination position by the illumination light actually irradiated on the eye E. 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 generating unit 51 and the illumination position of the illumination light in the image of the eye E to be examined. .

  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 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 areas obtained by dividing the illumination area. Each partial region is a region corresponding to one or more unit regions (one pixel, one digital micromirror, etc.). The in-plane pattern according to this embodiment is a binary pattern that indicates whether illumination light is turned on or off for each partial region that is divided into rectangular regions.

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

  The light quantity control unit 70 can perform the above-described light quantity 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 gradation value is a value in the range from the minimum value “0” to the maximum value “M” (M> 0, M is an integer). In this embodiment, the gradation value corresponds to the luminance value. A region having a large gradation value is a bright portion, and a region having a small gradation value is a dark portion.

  “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 illumination light amount currently applied. That is, “1 ×” on the vertical axis may indicate a control coefficient for outputting illumination light having 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 quantity 0.5 times the current illumination light quantity. “1.5 times” on the vertical axis represents a control coefficient for outputting illumination light having a light quantity 1.5 times the current illumination light quantity. That is, 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 in an area where the gradation value is m1 (0 <m1 <M) or more (that is, a bright part). Contains control information. Therefore, in the range where the gradation value is less than m1 and less than or equal to M, the amount of illumination light is controlled to decrease. 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) where the gradation value is m2 (0 <m2 ≦ m1 <M) or less. Control information to be included. Therefore, in the range where the gradation value is 0 or more and less than m2, the amount of illumination light is controlled to increase. The gradation value m <b> 2 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 luminance value” according to the embodiment, and the gradation value m2 is an example of the “second threshold value of luminance value” according to the embodiment.

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

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

[Data processing section]
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, detailed description thereof 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 section]
Various types of information are stored in the storage unit 102. 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 designating one or more in-plane patterns. The in-plane pattern information 102a is stored in the storage unit 102 in advance. The in-plane pattern information 102 a can be set by the user by using the operation unit 104.

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

[Display section]
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 or 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 section)
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) provided on the apparatus main body, a mouse of the computer 100, a keyboard, and the like. It is also possible to use any operation device or input device such as a trackball, a dedicated operation panel, a switch, a button, or a dial.

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

[Regarding control by the specifying unit 60 and the light amount control unit 70]
FIG. 5 is an operation explanatory diagram 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 the coordinate positions (1, 1) to (8, 6). Hereinafter, for convenience of explanation, a case where an in-plane pattern is applied to illumination light that illuminates the fundus Er of the eye E will be described, but the same applies to the case where an in-plane pattern is applied to slit light.

  Depending on the part of the eye E, the reflectance of the illumination light with respect to the part differs. For example, as shown in FIG. 5, in the fundus Er, the reflectance of the illumination light with respect to the optic nerve head P1 where the optic nerve head is located is high, and the reflectance of the illumination light with respect to the retina P2 and the illumination of the macula P3 where the fovea is located. Light reflectance is low. Therefore, when the eye E is illuminated with illumination light having a uniform light amount distribution, whiteout occurs in the optic nerve head P1, and black crush occurs in the retina P2 and the macula P3, and an image suitable for observation can be acquired. There are cases where it is not 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 with respect to the imaging region of the eye E as follows.

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

  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) that is not illuminated with illumination light and a partial area (black area) that is illuminated with illumination light having a predetermined reference light amount are designated. Thereby, the illumination light generation unit 51 illuminates the eye E with illumination light L2 having a light quantity distribution as shown in FIG. By imaging 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 acquired.

  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 condition and imaging region of the image G1 substantially match the imaging condition and imaging region of the image G2. That is, the image G2 is desirably an image acquired for the same imaging region using illumination light having the same light quantity distribution in the cross section of the light beam as when the image G1 was acquired.

  The identifying unit 60 identifies the correspondence relationship described above based on the image G1 acquired using the illumination light L1 and the image G2 acquired 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 specifying unit 60 obtains the difference between the image G1 and the image G2, and the obtained difference and the above-mentioned in-plane pattern By specifying the positional relationship with the pattern, it is possible to specify the aforementioned correspondence. Accordingly, when the image of the eye E to be examined acquired using the imaging device 13 is analyzed to identify the position of the characteristic part in the image, and the above-described correspondence is specified based on the position of the specified characteristic part Compared to the above, the processing load can be greatly reduced.

  Note that, in order to specify the above-described correspondence relationship, a case where the imaging conditions and the imaging region are matched for the image G1 and the image G2 will be described. However, if the above-described correspondence relationship can be specified, the image G1 and the image G2 will be described. It is desirable to match at least the imaging region.

  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). As a result, 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 can be identified easily and with high accuracy. The in-plane pattern may be a temporally irregular pattern.

  The control unit 101 can control the illumination light generation unit 51 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 during which the subject cannot perceive. The user can set the predetermined period by using the operation unit 104. Thereby, the above-described correspondence can be specified without the subject perceiving 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 with respect to the eye E.

  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). Even in this case, the above-described correspondence can be specified without the subject perceiving the in-plane pattern. In this case, the imaging device 13 is configured to include an imaging device capable of detecting return light from the invisible light described above.

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

  For example, in the vicinity of the coordinate position (2, 4) corresponding to the optic papilla P1, the reflectance of illumination light may be 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 amount of light is reduced in the area near the coordinate position (2, 4) as shown in FIG. The illumination light generation unit 51 is controlled.

  On the other hand, in the vicinity of the coordinate position (5, 4) corresponding to the macula P3, the reflectance of the illumination light is low and black crushing 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 amount of light is increased in the area near the coordinate position (5, 4) as shown in FIG. The illumination light generation unit 51 is controlled. By photographing the eye E using the imaging device 13, an image G <b> 3 of the eye E suitable for observation is acquired while suppressing occurrence of whiteout or blackout. By performing the above light amount control 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 the in-plane pattern information 102 a stored in the storage unit 102. The light quantity control unit 70 specifies an in-plane pattern that makes the light quantity uniform in the cross section of the light beam from the in-plane pattern information 102 a read from the storage unit 102. The light amount control unit 70 controls the illumination light generation unit 51 using the specified in-plane pattern, thereby controlling the light amount for each position in the light beam cross section. Thereby, the illumination light generation part 51 illuminates the area | region corresponding to the partial area | region of coordinate position (1,1)-(8,6) with the illumination light L1 which has a uniform light quantity. In addition, you may illuminate a some partial area | region with the illumination light L1 with uniform light quantity, without applying an in-plane pattern.

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

(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 this in-plane pattern, a partial area that is not illuminated with illumination light and a partial area that is illuminated with illumination light having a predetermined reference light amount are designated. 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 illumination light of the reference light amount.

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

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

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

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

(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 eye E. As a result, the image G3 of the eye E to be examined suitable for observation is acquired while suppressing the occurrence of overexposure or blackout due to illumination with the illumination light whose light amount has been controlled in S7.

(S9)
The control unit 101 determines whether to end 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 user's operation content on the operation unit 104. When it is determined not to end the operation of the slit lamp microscope 1 (S9: N), the operation of the slit lamp microscope 1 proceeds to S3. Therefore, in S5 thereafter, the specifying unit 60 can specify the above-described correspondence relationship using the image G2 acquired in S4 and the image G3 acquired in S8. Thereby, control of the light quantity with respect to the live image of the eye E to be examined can be performed in real time.

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

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

[effect]
The effect 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 photographing system (for example, the photographing system 7), a control unit (for example, the control unit 101), including. The illumination system includes an illumination light generation unit (for example, illumination light generation unit 51). The illumination light generation unit generates illumination light. The illumination system illuminates the eye to be examined (for example, eye E to be examined) with illumination light. The imaging system guides the return light of the illumination light from the eye to be examined to the imaging device (for example, the imaging device 13). The control unit controls the illumination light generation unit based on the luminance distribution in the 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 eye to be examined acquired by the imaging device, and thus has a light amount distribution corresponding to the luminance distribution of the image of the eye to be examined. The eye to be examined can be illuminated with illumination light. Accordingly, an image of the subject eye suitable for observation is obtained by illuminating the subject eye with illumination light having a light amount distribution changed in consideration of the difference in reflection of illumination light according to the imaging region of the subject eye. It becomes possible.

  Further, 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 within the beam cross section) and an illumination position of the illumination light in the image. The light amount control unit determines 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, thereby calculating 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 correspondence, the optimum corresponding to the region of the eye to be examined regardless of the position of the illumination system and the imaging system It is possible to simultaneously illuminate the subject's eye with a large amount of light.

  The light quantity control unit may control the light quantity so as to reduce the light quantity of the illumination light with respect to the illumination position of the bright part whose luminance value is equal to or higher than the first threshold in the image.

  According to such a configuration, since the amount of illumination light with respect to the illumination position corresponding to the bright portion of the image of the eye to be examined is reduced, the dynamic range of the imaging system can be expanded.

  The light quantity control unit may control the light quantity so as to increase the light quantity 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 in the image.

  According to such a configuration, since the amount of illumination light with respect to the illumination position corresponding to the dark part of the image of the eye to be examined is increased, the dynamic range of the imaging system can be expanded.

  In addition, the specifying unit may 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. ) And the correspondence relationship may be specified.

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

  The in-plane pattern may include at least a spatially irregular pattern.

  According to such a configuration, since the spatially irregular pattern is used as the in-plane pattern, it is possible to specify the correspondence relationship with high accuracy. For example, the difference between the image of the eye to be examined illuminated with illumination light to which the in-plane pattern is applied and the image of the eye to be examined illuminated with illumination light to which the in-plane pattern is not applied substantially corresponds to the in-plane pattern. . The positional relationship between the difference and the in-plane pattern may not be uniquely specified for the regular part, but may be uniquely specified for the irregular part. Therefore, by using at least a spatially irregular pattern as the in-plane pattern, the above correspondence can be specified with high accuracy.

  Further, the control unit may control the illumination light generation unit so that the eye to be examined is illuminated with illumination light having an in-plane pattern for at least a predetermined period.

  According to such a configuration, since the eye to be examined is illuminated with illumination light having an in-plane pattern for at least a predetermined period, the above correspondence can be specified without imposing a burden on the subject. It becomes possible.

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

  According to such a configuration, since the eye to be examined is illuminated with invisible light as illumination light having an in-plane pattern, it is possible to identify the above correspondence without imposing a burden on the subject. Become.

  Moreover, 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 the slit light, and the function of the slit lamp microscope having the above-described effect can be realized.

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

  According to such a configuration, since the illumination light is output by the projector, 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 (for example, an 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 arranged substantially coaxially, so that the eye to be examined that can be observed with the eyepiece and the image of the eye to be examined acquired by the imaging device are substantially the same. Can be made.

  Moreover, the control method of the ophthalmologic imaging 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, the illumination system 8) and an imaging system (for example, the imaging system 7). The illumination system includes an illumination light generation unit (for example, illumination light generation unit 51). The illumination light generation unit generates illumination light. The illumination system illuminates the eye to be examined (for example, eye E to be examined) with illumination light. The imaging system guides the return light of the illumination light from the eye to be examined to the imaging device (for example, the imaging device 13). In the acquisition step, an image of the eye to be examined is acquired 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. However, 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 photographing system is coupled to the optical path of the illumination system.

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

  FIG. 7 shows a configuration example of the optical system of the slit lamp microscope according to this embodiment. In FIG. 7, the same parts as those in FIG.

  The configuration of the slit lamp microscope 1A according to this embodiment is different from the configuration of the slit lamp microscope 1 shown in FIG. 2 in that the optical path of the photographing 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.

  Similar to the observation system 6, the observation system 6 </ b> A includes a pair of left and right optical systems. Each of the left and right optical systems of the observation system 6A includes an objective lens 31, a variable magnification optical system 32, a diaphragm 33, a relay lens 35, a prism 36, and an eyepiece lens 37. In FIG. 7, only one of the left and right optical systems of the observation system 6A is shown. Reference symbol O1A denotes the optical axis (observation optical axis) of the observation system 6A. The observation system 6A is disposed in the barrel main body 9A.

  The imaging system 7 </ b> A includes the 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 (imaging optical axis) of the imaging system 7A and the optical axis (illumination optical axis) of the illumination system 8A.

  The beam splitter 34A splits the light traveling along the optical axis O2A into two. The light reflected by the beam splitter 34 </ b> A is guided to the image sensor 43 of the imaging device 13 via the relay lens 41. The image sensor 43 detects the reflected light and generates an image signal. Instead of the beam splitter 34A, a dichroic mirror or a half mirror may be arranged.

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

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

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

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

  The ophthalmologic photographing apparatus (for example, slit lamp microscope 1A) according to the embodiment includes a second optical path coupling member (for example, 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 eye to be examined can be accurately obtained. It becomes possible to specify. Further, since the positions of the photographing system and the illumination system can be fixed, this correspondence relationship is constant, and processing for specifying the correspondence relationship becomes unnecessary.

[Third Embodiment]
In the slit lamp microscope according to the first embodiment or the second embodiment, the case where the light amount distribution of the illumination light is controlled based on the luminance distribution of the image of the eye to be examined has been described. However, the slit lamp microscope according to the embodiment is It is not limited to this. In the third embodiment, the attention area in the image of the eye to be examined is specified, and the amount of illumination light with respect to the specified attention area 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. In the following, the second embodiment will be described focusing on the differences from the first embodiment.

  The control unit according to this embodiment specifies the region of interest by analyzing the image of the eye E acquired using the imaging device 13 at 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 attention area includes an area corresponding to the pupil, an area corresponding to the cornea, an area corresponding to the optic nerve head, an area corresponding to the retina, an area corresponding to the macula.

  For example, the specifying unit can specify a region of interest based on position information of one or more characteristic parts set in advance for the image of the eye E. Examples of the characteristic part include an iris, a running state of blood vessels, and a macula. The position information of the characteristic part may be determined in advance or may be set by the user using the operation unit 104. 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.

  In the light amount control unit, the control unit according to this embodiment controls the light amount at the position in the light beam cross section (in-plane position) of the illumination light corresponding to at least the region of interest specified by the specifying unit.

  For example, the light amount control unit controls the amount of light so as to reduce the amount of illumination light irradiated to the region of interest. Thereby, when the attention area specified by the specifying unit is an area corresponding to the pupil, the amount of illumination light incident on the pupil can be reduced. Therefore, no uncomfortable feeling is given to the subject. In addition, it is possible to avoid a situation where 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 caused by reflection of illumination light by the cornea and the optic disc that are unnecessary for observation.

  Further, the light amount control unit may control the light amount so as to increase the light amount of the illumination light irradiated to the attention area. Thereby, 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 black crushing of the image and obtain an image suitable for observation.

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

  In the ophthalmologic photographing 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 the in-plane position of the illumination light corresponding to at least the attention area.

  According to such a configuration, the amount of illumination light with respect to the region of interest specified in the image of the eye to be examined is controlled, so that it corresponds to the part of the eye to be examined regardless of the position of the illumination system and the imaging system. The eye to be examined can be illuminated at the same time with the optimum light quantity.

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

  According to such a configuration, the subject does not feel uncomfortable. In addition, it is possible to avoid a situation where 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 embodiment described above is merely an example 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 variable power optical system 33 aperture 35, 41 relay lens 36 prism 37 eyepiece 34 , 34A Beam splitter 43 Image sensor 51 Illumination light generation unit 60 Identification unit 70 Light amount control unit 100 Computer 101 Control unit 102 Storage unit 102a In-plane pattern information 102b Control table information 103 Display unit 104 Operation unit 110 Data processing unit E Eye to be examined

Claims (13)

An illumination system that illuminates the eye to be examined with the illumination light, comprising an illumination light generator that generates illumination light;
An imaging system for guiding the return light of the illumination light from the eye to be imaged to an imaging device;
A control unit that controls the illumination light generation unit based on a luminance distribution in an image acquired by the imaging device;
Only including,
The controller is
A specifying unit that specifies a correspondence relationship between an in-plane position of the illumination light generated by the illumination light generation unit and an illumination position of the illumination light in the image;
Control information is determined for each illumination position based on the correspondence specified by the specifying unit, and the amount of light is calculated for each in-plane position by controlling the illumination light generation unit based on the determined control information. A light amount control unit for controlling
Ophthalmic imaging device that includes a. The ophthalmologic according to claim 1, wherein the light amount control unit controls the light amount so as to reduce a light amount of illumination light with respect to an illumination position of a bright portion having a luminance value equal to or greater than a first threshold in the image. Shooting device. The light quantity control unit, the luminance value in the image was claim 1 or, characterized in that for controlling the amount of light to increase the amount of illumination light to the illumination position of the dark part is below the second threshold claim ophthalmic imaging apparatus according to 2. The specifying unit specifies the correspondence relationship based on a first image acquired using the illumination light and a second image acquired using illumination light having a predetermined in-plane pattern. ophthalmic imaging apparatus according to any one of claims 1 to 3, characterized. The ophthalmic imaging apparatus according to claim 4, wherein the in-plane pattern includes at least a spatially irregular pattern. Wherein the control unit is according to claim 4 or wherein the controller controls the illumination light generation unit so as to illuminate the eye to be examined with illumination light having the plane pattern by at least a predetermined period of time to claim 5 The ophthalmic imaging apparatus described. The ophthalmologic photographing apparatus according to any one of claims 4 to 6, wherein the illumination light including the in-plane pattern is invisible light. An illumination system that illuminates the eye to be examined with the illumination light, comprising an illumination light generator that generates illumination light;
An imaging system for guiding the return light of the illumination light from the eye to be imaged to an imaging device;
A control unit that controls the illumination light generation unit based on a luminance distribution in an image acquired by the imaging device;
Including
The controller is
A specifying unit for specifying a region of interest by analyzing the image;
A light amount control unit for controlling the light amount of at least an in-plane position of illumination light corresponding to the region of interest;
Including
The region of interest is a region in the image corresponding to a pupil, cornea, or optic disc;
The light quantity control unit, ophthalmology imaging apparatus which performs the control of the light amount to lower the light level of the illumination light irradiated on the region of interest. The ophthalmologic photographing apparatus according to any one of claims 1 to 8, wherein the illumination light generation unit generates illumination light whose shape can be arbitrarily changed. The ophthalmologic photographing apparatus according to any one of claims 1 to 9, wherein the illumination light generation unit includes a projector capable of outputting light having an illumination pattern that can be arbitrarily changed. An observation system comprising an eyepiece, and guiding the return light of the illumination light from the eye to the eyepiece;
Ophthalmic imaging apparatus according to any one of claims 1 to 10, characterized in that it comprises a first optical path coupling member for coupling the optical path of the imaging system in the optical path of the observation system. An illumination system that illuminates the eye to be examined with the illumination light, comprising an illumination light generator that generates illumination light;
An imaging system for guiding the return light of the illumination light from the eye to be imaged to an imaging device;
A control unit that controls the illumination light generation unit based on a luminance distribution in an image acquired by the imaging device;
A second optical path coupling member that couples the optical path of the imaging system to the optical path of the illumination system ;
Ophthalmic imaging device that includes a. Control of an ophthalmologic imaging apparatus including an illumination system that includes an illumination light generation unit that generates illumination light and that illuminates the subject's eye with the illumination light, and an imaging system that guides return light of the illumination light from the eye to the imaging device A method,
An acquisition step of acquiring an image of the eye to be examined by the imaging device;
A control step of controlling the illumination light generator based on a luminance distribution in the acquired image;
Only including,
The control step specifies a correspondence relationship between an in-plane position of the illumination light generated by the illumination light generation unit and an illumination position of the illumination light in the image, and the illumination based on the identified correspondence relationship control information determined for each location, controlling the amount of light for each of the in-plane position by controlling the illumination light generator based on the determined control information, the control method of ophthalmology imaging device.

Images