JP6691596B2 - Ophthalmic imaging device - Google Patents

Description

This invention also relates to the ophthalmic imaging equipment.

  The ophthalmologic photographing apparatus is used to acquire an image of an eye to be inspected. A slit lamp microscope (slit lamp), a fundus camera, and the like are known as ophthalmologic imaging apparatuses.

  The ophthalmologic photographing apparatus is generally configured to include 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 subject's eye to the imaging device. The ophthalmologic imaging apparatus acquires an image of the eye to be inspected using the imaging device.

JP, 2014-188339, A

  In the conventional ophthalmologic imaging apparatus, the illumination system illuminates the subject's eye with illumination light having a uniform light amount within the light flux cross section (that is, spatially uniform illumination light) regardless of the site of the subject's eye. As a result, whiteout or blackout may occur due to the difference in reflectance between parts, and it may not be possible to acquire an image suitable for observation.

  Further, since the eye to be inspected is illuminated with illumination light having a uniform amount of light within the cross section of the light flux, when strong light enters the pupil, the subject may feel dazzled and may give discomfort to the subject. Further, due to the miosis, it may not be possible to continue photographing or observing the eye to be inspected.

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

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 subject's eye with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to the imaging device. The control unit specifies the attention area by analyzing the image acquired by the imaging device, and controls at least the light amount at the in-plane position of the illumination light corresponding to the attention area. When the attention area is an area in the image corresponding to the cornea or the optic disc, the control unit controls the light amount so as to reduce the light amount of the illumination light with which the attention area is irradiated. When the attention area is an area in the image corresponding to the retina or the macula, the control unit controls the light quantity so as to increase the light quantity of the illumination light with which the attention area is irradiated.
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 subject's eye with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to the imaging device. In the acquisition step, the image of the subject's eye is acquired by the imaging device. In the control step, the region of interest in the image corresponding to the pupil, cornea, or optic disc is identified by analyzing the acquired image, and the light amount is controlled so that at least the amount of illumination light irradiated to the region of interest is reduced. is Ru is carried out.

  According to the present invention, it is possible to provide a new technique of an ophthalmologic imaging apparatus for acquiring an image of an eye to be inspected.

It is a schematic side view showing an example of the external appearance structure of the ophthalmologic imaging apparatus which concerns on embodiment. It is a schematic diagram showing an example of composition of an optical system of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of a control system of an ophthalmology photographing instrument concerning an embodiment. It is operation | movement explanatory drawing of the ophthalmology imaging | photography apparatus which concerns on embodiment. It is operation | movement explanatory drawing of the ophthalmology imaging | photography apparatus which concerns on embodiment. It is a flow figure showing an example of operation of an ophthalmology photographing instrument concerning an embodiment. It is a schematic diagram showing an example of composition of an optical system of an ophthalmology photographing instrument concerning an 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. Note that the contents of the documents described in this specification can be appropriately incorporated 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 to this. Examples of the ophthalmologic imaging apparatus to which the present invention can be applied include a slit lamp microscope, a fundus camera, a scanning laser ophthalmoscope (SLO), and a laser photocoagulation apparatus. Further, the imaged part by the ophthalmologic imaging apparatus according to the embodiment may be any part of the eye to be inspected, and for example, in the anterior ocular segment, it may be the cornea, vitreous body, crystalline lens, ciliary body, or corner angle. However, the posterior segment of the eye may be the retina, choroid, or vitreous. Further, the imaged region may be a region around the eye such as an eyelid or an orbit.

  First, the direction is defined. In the optical system of the apparatus, the direction from the optical element located closest to the subject to the subject is the front direction, and the opposite direction is the rear direction. The horizontal direction orthogonal to the front direction is defined as the left-right direction. Further, a 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 processing and arithmetic processing. Instead of providing the computer 100 separately from the microscope main body (a housing that stores the optical system and the like), it is also possible to apply a configuration in which a similar computer is mounted on the microscope main body.

  The slit lamp microscope 1 is placed on the table 2. The computer 100 may be installed on another table or at another place. The base 4 is configured to be movable in the horizontal direction via the moving mechanism section 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 portion 15 so as to be rotatable in the left-right direction. A support arm 17 that supports 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. The support arms 16 and 17 may be configured to be rotated by an electric mechanism. In that case, an actuator that generates a driving force for rotating the support arms 16 and 17 and a transmission mechanism that transmits the driving force are provided. The actuator is composed of, for example, a pulse motor. The transmission mechanism is composed of, for example, a combination of gears or 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 be swung in the left-right direction about the rotation axis. Thereby, the irradiation direction of the illumination light with respect to the eye E is changed. The illumination system 8 may be configured to swing in the vertical direction as well. That is, it may be configured so that the elevation angle and depression angle of the illumination light can be changed.

  The observation system 6 has a pair of left and right optical systems that guide the reflected light of the illumination light from the eye E to be inspected. Further, 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 photographing system is coupled to the optical path of the observation system 6 inside 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 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 orientation of the observation system 6 with respect to the eye E can be changed. It should be noted that the reflected light of the illumination light includes various kinds of light such as scattered light that has passed through the eye E, but these various kinds of light are collectively referred to as “reflected light” or “returned light”. To do. Further, in fluorescence contrast imaging or fluorescence contrast observation using illumination light as excitation light, fluorescence emitted by the 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 10a and a forehead rest 10b for stably arranging the subject's face.

  An observation magnification operation knob 11 for changing the observation magnification is arranged on the side surface of the lens barrel body 9. Further, an image pickup device 13 for taking an image of the eye E is connected to the lens barrel body 9. The image pickup device 13 is configured to include an image pickup element. The image pickup 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. As the image sensor, 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 flux output from the illumination system 8 toward the subject's eye E is disposed below the illumination system 8.

[Structure 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, a photographing 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 almost the same configuration. The examiner can observe the eye E to be inspected binocularly by the left and right optical systems. Note that FIG. 2 shows only one of the left and right optical systems of the observation system 6. Reference numeral O1 represents 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 power 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 portion 9a. The symbol P indicates the image forming position of the light guided to the eyepiece lens 37. Reference symbol Ec indicates the cornea of the eye E, reference symbol Ep indicates the iris, and reference symbol Er indicates the fundus. Reference symbol Eo indicates the examiner's eye.

  The variable power optical system 32 is configured to include 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 in 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 macroscopic image of the eye E or the captured image can be changed. The change of the magnification, that is, the switching of the variable power lens group arranged in the optical path of the observation system 6 is performed by operating the observation magnification operation knob 11. Alternatively, a switch or the like (not shown) may be used to electrically change the magnification.

  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 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 has 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 image pickup device 13 includes the image pickup element 43. The image pickup surface of the image pickup element 43 is arranged at a position that is substantially conjugate with the imaged region (observation region) of the eye E (that is, 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 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.

[Illumination system]
The illumination system 8 includes an illumination light generator 51 and a condenser lens 55. Reference numeral O2 indicates the optical axis of the illumination system 8 (illumination optical axis).

  The illumination light generation unit 51 is arranged at a position that is substantially conjugate with the imaging site of the eye E (that is, the illumination position of the illumination light by the illumination system 8). For example, the pupil position of the light source of the illumination light generated by the illumination light generation unit 51 is arranged at a position that is substantially conjugate with the imaging site of the eye E to be examined.

  The illumination light generator 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 flux or the shape of the projected image. The illumination light generation unit 51 outputs the illumination light whose slit width, slit light direction (slit direction), slit light length, and shape can be arbitrarily changed based on the control by the control unit 101. Generate as. That is, the illumination light generator 51 can generate illumination light having a desired shape as slit light.

  The illumination light generator 51 is configured to include, for example, a projector. The projector can output light of an illumination pattern that can be changed arbitrarily as illumination light. The illumination pattern represents the shape of the cross section of the light flux, the distribution of the amount of light and the distribution of colors in the cross section of the light flux. The projector outputs light of an illumination pattern set in advance under the control of the control unit 101. Accordingly, the projector can output illumination light whose slit width, slit light direction, slit light length, and shape can be arbitrarily changed as slit light.

  The illumination pattern can be set by the user using the operation unit 104 described later, for example. When the user uses the operation unit 104 to specify, for example, a shape pattern, an outer shape, a size, etc., 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 that uses 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 RGB color components. The projector may further include a relay optical system, a collimator lens, a projection lens, and the like.

  Further, the projector may be one that uses LCoS (Liquid Crystal on Silicon) or MEMS (Micro Electro Mechanical Systems). Further, the projector may use a liquid crystal display (hereinafter, LCD) (transmissive type, reflective type). Since such a configuration is publicly known, detailed description will be omitted. The projector may be any one that can output illumination light corresponding to an illumination pattern whose shape and the like can be arbitrarily changed.

  Note that the illumination light generator 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 generator 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 flux cross section by controlling the illumination light generation unit 51 based on the brightness distribution in the image of the eye E to be inspected 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 identifying unit 60 identifies the correspondence relationship 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 inspected acquired by 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 within the light flux cross section of the illumination light. The identification 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 mainly includes a control unit 101. It should be noted that FIG. 3 shows only the constituent parts of particular interest in this embodiment, and omits the other constituent parts.

[Control part]
The control unit 101 controls each unit of the slit lamp microscope 1. For example, the control unit 101 controls the observation system 6, the imaging system 7, the illumination system 8, 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 diaphragm 33. The control of the imaging system 7 includes control of the charge storage time, sensitivity, frame rate, etc. of the image sensor 43. The control of the illumination system 8 includes control of the illumination light generation unit 51. Control of the data processing unit 110 includes control of image generation processing based on the image signal obtained by the image sensor 43, control of analysis processing of the generated image, and the like. Further, the control unit 101 performs a process of reading data stored in the storage unit 102 and a process of writing data in the storage unit 102.

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

<Specification part>
The identifying unit 60 identifies the correspondence between the position illuminated by the illumination light generated by the illumination light generator 51 and the illumination position of the illumination light actually applied to the eye E. Specifically, the identifying unit 60 identifies the correspondence relationship between the position within the luminous flux cross section (in-plane position) of the illumination light generated by the illumination light generator 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 relationship using an in-plane pattern (landmark, position specifying pattern) represented by in-plane pattern information 102a described later. The in-plane pattern indicates a 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 area is an area corresponding to one or more unit areas (one pixel, one digital micromirror, etc.). It is assumed that the in-plane pattern according to this embodiment is a binary pattern that indicates whether the illumination light is on or off for each of the partial areas divided into rectangular areas.

<Light intensity controller>
The light amount control unit 70 controls the illumination light generation unit 51 based on the correspondence specified by the specifying unit 60, thereby controlling the light amount for each position within the light flux cross section (for each unit area) of the illumination light. 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 illumination light generation unit 51 based on the determined control information to control the light amount for each position within the light flux cross section.

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

  FIG. 4 shows an explanatory diagram of the control table information 102b according to this embodiment. In FIG. 4, the horizontal axis represents the gradation value in the image of the eye E and the vertical axis represents the 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 area of the in-plane pattern. The gradation value is a value in the range of the minimum value “0” to the maximum value “M” (M> 0, M is an integer). In this embodiment, the grayscale value corresponds to the luminance value. Areas with large gradation values are bright areas, and areas with small gradation values are dark areas.

  “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 represents control information for outputting illumination light having a light quantity of 0.5 times the reference light quantity. “1.5 times” on the vertical axis represents control information for outputting illumination light having a light amount of 1.5 times the reference light amount.

  Further, 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 the control coefficient for outputting the illumination light of the current illumination light amount as the control information. In this case, “0.5 times” on the vertical axis indicates a control coefficient for outputting illumination light having a light amount of 0.5 times the current illumination light amount. “1.5 times” on the vertical axis indicates a control coefficient for outputting the illumination light whose light amount is 1.5 times the current illumination light amount. That is, a range exceeding "1 times" on the vertical axis shows a control coefficient for increasing the current illumination light amount, and a range less than "1 times" on the vertical axis shows a control coefficient for decreasing the current illumination light amount. .

  The control table information 102b is for controlling the illumination light generation unit 51 so as to reduce the light amount of the illumination light with respect to the illumination position of the area (that is, the bright portion) where the gradation value is m1 (0 <m1 <M) or more. Contains control information. Therefore, in the range where the gradation value is less than m1 and less than or equal to M, the light amount of the 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 light amount of the illumination light with respect to the illumination position of the area (that is, the dark portion) where the gradation value is m2 (0 <m2 ≦ m1 <M) or less. It includes control information for doing. Therefore, in the range where the gradation value is 0 or more and less than m2, the light amount of the illumination light is controlled to increase. 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 brightness value” according to the embodiment, and the gradation value m2 is an example of the “second threshold value of the brightness 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 advance in this hard disk drive. The operation of the control unit 101 is realized by the cooperation of this control program and the above hardware.

  The control unit 101 is arranged in the device body of the slit lamp microscope 1 (for example, in the base 4) 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, detailed description thereof will be omitted. The data processing unit 110 may be configured to perform a predetermined analysis process on the image generated based on the image signal. The data processing unit 110 is arranged in the main body of the slit lamp microscope 1 and the computer 100 together with the control unit 101.

[Memory]
Various information is stored in the storage unit 102. In particular, the in-plane pattern information 102a and the control table information 102b are stored in the storage unit 102 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 102a can be set by the user 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 device body of the slit lamp microscope 1 or may be provided in the computer 100.

[Operation part]
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 body, a mouse of the computer 100, a keyboard, and the like. Further, it is possible to use any operation device or input device such as a trackball, a dedicated operation panel, a switch, a button, a dial or the like.

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

[Regarding Control by Identifying Unit 60 and Light Amount Control Unit 70]
FIG. 5 shows an operation explanatory diagram of the identifying 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 shown. Here, it is assumed that the plurality of partial areas are arranged at coordinate positions (1, 1) to (8, 6). Hereinafter, for convenience of description, the case where the in-plane pattern is applied to the illumination light that illuminates the fundus Er of the eye E to be examined will be described, but the same applies when the in-plane pattern is applied to the slit light.

  Depending on the part of the eye E to be examined, 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 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 macular portion P3 where the fovea is located are illuminated. Light reflectance is low. Therefore, when the eye E to be inspected is illuminated with illumination light having a uniform light amount distribution, white spots occur in the optic papilla P1 and black crushing occurs in the retina P2 and the macula P3, and an image suitable for observation can be obtained. Sometimes you can't. 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 to be examined as follows.

  First, the light amount control unit 70 illuminates the subject's eye E with the illumination light L1 having a uniform light amount within the light flux cross section. For example, the light quantity control unit 70 controls the illumination light generation unit 51 by using an in-plane pattern that makes the light quantity uniform in the light flux cross section, thereby controlling the light quantity for each light flux cross section position. Thereby, the illumination light generation unit 51 illuminates the area corresponding to the partial area of the coordinate positions (1, 1) to (8, 6) with the illumination light L1 having a uniform light amount. An image G1 of the subject's eye E illuminated with the illumination light L1 having a uniform light quantity is acquired by photographing the subject's eye E using the image pickup device 13.

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

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

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

  The identifying unit 60 identifies the above-described correspondence relationship 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. Thereby, when the image of the eye E to be inspected acquired by using the imaging device 13 is analyzed to specify the position of the characteristic part in the image, and the above-mentioned correspondence is specified based on the position of the specified characteristic part. The processing load can be significantly reduced compared to.

  It should be noted that, in order to specify the above-mentioned correspondence, a case will be described in which the image capturing conditions and the imaged parts of the images G1 and G2 are matched. However, if the above-described corresponding relationship can be identified, the image G1 and the image G2 It is desirable to match at least the imaged parts.

  The in-plane pattern applied to the illumination light L2 includes at least a spatially irregular pattern (nonuniform pattern, nonuniform pattern), as shown in FIG. This makes it possible to easily and highly accurately specify the positional relationship between the difference between the images G1 and G2 and the in-plane pattern applied to the illumination light L2. The in-plane pattern may be a temporally irregular pattern.

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

  The illumination light including the in-plane pattern may be invisible light. At least the in-plane pattern may be projected on the eye E by invisible light (for example, infrared light). Even in this case, the subject can specify the above-mentioned correspondence without 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 described above.

  The light amount 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 illumination light generation unit 51 based on the determined control information to control the light amount for each position within the light flux cross section.

  For example, in a region near the coordinate position (2, 4) corresponding to the optic papilla P1, the reflectance of the 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, as shown in FIG. 6, the light quantity is lowered in the area near the coordinate position (2, 4). The illumination light generator 51 is controlled.

  On the other hand, in the region near 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, as shown in FIG. 5, the light quantity is increased in the area near the coordinate position (5, 4). The illumination light generator 51 is controlled. By photographing the eye E to be inspected using the imaging device 13, the image G3 of the eye E suitable for observation is acquired while suppressing the occurrence of whiteout and blackout. By controlling the light amount using the image G3 instead of the image G1, it is possible to acquire a live image suitable for observation. 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 flow chart 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 is uniform in the light flux cross section, based on the in-plane pattern information 102a 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 to control the light amount for each position within the light flux cross section. Thereby, the illumination light generation unit 51 illuminates the area corresponding to the partial area of the coordinate positions (1, 1) to (8, 6) with the illumination light L1 having a uniform light amount. Note that the 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 image the eye E to be inspected. As a result, the image G1 of the subject's eye E illuminated with the illumination light having a uniform light amount in S1 is acquired.

(S3)
Next, the light quantity control unit 70 identifies 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 which is not illuminated by the illumination light and a partial area which is illuminated by the illumination light of a predetermined reference light quantity 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 reference light amount of illumination light.

  The light amount control unit 70 controls the illumination light generation unit 51 using the specified in-plane pattern to control the light amount for each position within the light flux cross section. Thereby, the illumination light generator 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 image the eye E to be inspected. Thereby, the image G2 of the subject's eye E illuminated with the illumination light having the light amount distribution corresponding to the in-plane pattern is acquired in S3.

(S5)
The identifying unit 60 identifies the above-described correspondence relationship 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)
The light amount 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 illumination light generation unit 51 based on the control information determined in S6 to control the light amount for each position within the light flux cross section.

(S8)
The control unit 101 controls the imaging device 13 to image the eye E to be inspected. As a result, the image G3 of the eye E to be inspected, which is suitable for observation, is obtained while suppressing the occurrence of overexposure and underexposure due to being illuminated with the illumination light whose light amount is 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 to end the operation of the slit lamp microscope 1 based on the operation content of the user with respect to the operation unit 104. When it is determined that the operation of the slit lamp microscope 1 is not ended (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-mentioned correspondence relationship by using the image G2 acquired in S4 and the image G3 acquired in S8. Accordingly, the control of the light amount of the live image of the eye E to be inspected can be executed in real time.

  When it is determined to end the operation of the slit lamp microscope 1 (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 a “specification step” according to the embodiment. S7 is an example of a "control step" according to the embodiment.

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

  The ophthalmologic imaging apparatus (eg, slit lamp microscope 1) according to the embodiment includes an illumination system (eg, illumination system 8), an imaging system (eg, imaging system 7), a control unit (eg, 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 an eye to be inspected (for example, eye E to be inspected) with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to the imaging device (for example, the imaging device 13). The control unit controls the illumination light generation unit based on the brightness distribution in the image acquired by the imaging device.

  According to such a configuration, since the illumination light control unit is controlled based on the brightness distribution of the image of the eye to be inspected acquired by the imaging device, it has a light amount distribution corresponding to the brightness distribution of the image of the eye to be inspected. The eye to be inspected can be illuminated with the illumination light. Thereby, by illuminating the eye to be inspected 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 observed suitable for observation is acquired. It will be 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 the in-plane position of the illumination light generated by the illumination light generation unit (for example, the position within the light flux cross section) and the 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 identification unit, and controls the illumination light generation unit based on the determined control information to control the light amount for each in-plane position. Control.

  According to such a configuration, by controlling the light amount for each in-plane position of the illumination light based on the above correspondence, the optimum amount corresponding to the site of the eye to be examined regardless of the position of the illumination system and the imaging system. It is possible to illuminate the eye to be inspected at the same time with various light amounts.

  Further, the light amount control unit may control the light amount so as to reduce the light amount of the illumination light with respect to the illumination position of the bright part having a brightness value of the first threshold value or more in the image.

  With such a configuration, the light amount of the illumination light with respect to 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 widened.

  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 portion whose brightness value is equal to or less than the second threshold in the image.

  With such a configuration, the light amount of the illumination light with respect to 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 widened.

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

  According to such a configuration, since the correspondence is specified by 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, since the at least spatially irregular pattern is used as the in-plane pattern, it is possible to specify the above correspondence with high accuracy. For example, the difference between the image of the eye to be inspected illuminated with the illumination light to which the in-plane pattern is applied and the image of the eye to be inspected illuminated with the illumination light to which the in-plane pattern is not applied is substantially equivalent 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 it is possible to uniquely specify 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 as to illuminate the subject's eye with the illumination light having the in-plane pattern for at least a predetermined period.

  According to such a configuration, since the eye to be inspected is illuminated with the illumination light having the in-plane pattern for at least the predetermined period, it is possible to specify the above correspondence without burdening the subject. It will be possible.

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

  According to such a configuration, since the eye to be inspected is illuminated with the invisible light as the illumination light having the in-plane pattern, it is possible to specify the above correspondence without burdening the subject. Become.

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

  With such a configuration, the illumination light that can be changed into 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 having an illumination pattern that can be changed arbitrarily.

  According to such a configuration, since the projector outputs the illumination light, the configuration and control of the ophthalmologic imaging apparatus can be simplified.

  Moreover, the ophthalmologic imaging 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 lens (for example, eyepiece lens 37). The observation system guides the return light of the illumination light from the subject's eye to the eyepiece lens. 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, since the optical path of the imaging system and the optical path of the observation system can be arranged substantially coaxially, the eye to be observed with the eyepiece and the image of the eye to be acquired by the imaging device are substantially matched. Can be made.

  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 photographing apparatus includes an illumination system (for example, illumination system 8) and a photographing system (for example, photography 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 an eye to be inspected (for example, eye E to be inspected) with illumination light. The imaging system guides the return light of the illumination light from the subject's eye to the imaging device (for example, the imaging device 13). In the acquisition step, the image of the subject's eye is acquired by the imaging device. In the control step, the illumination light generation unit is controlled based on the brightness 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. 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. 7, the same parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

  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 imaging system is coupled to the optical path of the illumination system. The slit lamp microscope 1A includes an observation system 6A, a photographing system 7A, and an illumination system 8A.

  The observation system 6A includes a pair of left and right optical systems, like 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 diaphragm 33, a relay lens 35, a prism 36, and an eyepiece lens 37. Note that FIG. 7 shows only one of the left and right optical systems of the observation system 6A. Reference numeral O1A is an optical axis (observation optical axis) of the observation system 6A. The observation system 6A is arranged in the lens barrel body 9A.

  The image capturing system 7A includes the relay lens 41 and the image capturing device 13, similarly to the image capturing system 7. The imaging system 7A may further include a beam splitter 34A. Reference numeral O2A indicates an optical axis of the image capturing system 7A (image capturing optical axis) and an 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 imaging element 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 has 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, the description thereof will be 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 imaging apparatus according to this embodiment will be described.

  The ophthalmologic imaging apparatus (eg, slit lamp microscope 1A) according to the embodiment includes a second optical path coupling member (eg, beam splitter 34A). The second optical path coupling member couples the optical path of the imaging system (for example, the imaging system 7A) with 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 inspected can be accurately determined. It becomes possible to specify. Further, since the positions of the photographing system and the illumination system can be fixed, this correspondence becomes constant, and the process of identifying the correspondence 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 brightness distribution of the image of the eye to be examined has been described. It is not limited to this. In the third embodiment, the attention area in the image of the eye to be inspected is specified, and the light amount of the illumination light for the specified attention area is controlled.

  The configuration of the slit lamp microscope according to the third embodiment is similar to 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 attention area by analyzing the image of the eye E to be inspected acquired by using the imaging device 13 in the specifying unit. The attention area is predetermined. 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 to be inspected. The characteristic parts include the iris, the running state of blood vessels, and the 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. Further, the specifying unit may specify the attention area by searching the 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 at the light beam cross-section position (in-plane position) of the illumination light corresponding to at least the attention area specified by the specifying unit 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 with which the attention area is irradiated. Thereby, when the attention area specified by the specifying unit is the area corresponding to the pupil, the light amount of the 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 the observation cannot be continued due to miosis.

  Further, when the region of interest specified by the specifying unit is the region corresponding to the cornea or the optic disc, it is possible to remove the artifacts caused by the reflection of the illumination light by the cornea or the optic disc that is not necessary for observation.

  The light amount control unit may control the light amount so as to increase the light amount of the illumination light with which the attention area is irradiated. Thereby, when the attention area specified by the specifying unit is an area corresponding to the retina or the macula, the light amount of the illumination light applied to the retina or the macula can be increased. Therefore, it is possible to prevent the image from being blackened and obtain an image suitable for observation.

[effect]
The effects of the ophthalmologic imaging 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 the attention area by analyzing the image. The light amount control unit controls at least the light amount at the in-plane position of the illumination light corresponding to the attention area.

  According to such a configuration, since the light amount of the illumination light for the attention area specified in the image of the eye to be inspected is controlled, it corresponds to the site of the eye to be inspected regardless of the positions of the illumination system and the imaging system. It is possible to illuminate the eye to be inspected at the same time with an optimum light amount.

  The region of interest may be a region in the image corresponding to the pupil, cornea, or optic disc. The light quantity control unit may control the light quantity so as to reduce the light quantity of the illumination light with which the attention area is irradiated.

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

  The embodiments described above are merely examples for implementing the present invention. A person who intends to implement the present invention can make arbitrary modifications, omissions, additions, substitutions, etc. within the scope of the gist 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 magnification optical system 33 Aperture 35, 41 Relay lens 36 Prism 37 Eyepiece 34 , 34A Beam splitter 43 Imaging device 51 Illumination light generation unit 60 Identification unit 70 Light intensity 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 (5)

An illumination system that includes an illumination light generation unit that generates illumination light, and illuminates an eye to be inspected with the illumination light,
An imaging system that guides the return light of the illumination light from the eye to be examined to an imaging device,
A control unit that specifies the attention area by analyzing the image acquired by the imaging device, and controls at least the light amount of the in-plane position of the illumination light corresponding to the attention area,
Including,
When the region of interest is the cornea, or a region in the image corresponding to the optic disc, the control unit performs the control of the light amount so as to reduce the light amount of the illumination light irradiated to the attention region,
When the attention area is an area in the image corresponding to the retina or the macula, the control unit controls the light amount so as to increase the light amount of the illumination light with which the attention area is irradiated. . The ophthalmic imaging apparatus according to claim 1, wherein the illumination light generation unit generates illumination light whose shape can be arbitrarily changed. The ophthalmic imaging apparatus according to claim 1 or 2, wherein the illumination light generation unit includes a projector that can output light of an illumination pattern that can be changed arbitrarily. An observation system including an eyepiece, which guides return light of the illumination light from the eye to be examined to the eyepiece,
The 1st optical-path coupling member which couple | bonds the optical path of the said imaging system with the optical path of the said observation system. The ophthalmologic imaging apparatus as described in any one of Claims 1-3. The ophthalmologic photographing 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 with an optical path of the illumination system.

Images