JP2020157041A - Slit lamp microscope - Google Patents

Abstract

To solve a problem in a Scheimpflug type slit lamp microscope caused by the difference in refractive index inside and outside of a subject's eye.SOLUTION: A slit lamp microscope of the exemplary embodiment includes an illumination system and an imaging system. The illumination system projects slit light onto an anterior segment of a subject's eye. The imaging system includes an optical system that guides the light from the anterior segment to which the slit light is projected, and an imaging element that receives the light guided by the optical system on an imaging surface. The object surface including the focal point of the illumination system displaced by the refractive index of the tissue of the anterior segment of the eye, the main surface of the optical system, and the imaging surface are arranged so as to satisfy the Scheimpflug condition.SELECTED DRAWING: Figure 4

Description

The present invention relates to a slit lamp microscope.

Diagnostic imaging occupies an important position in the field of ophthalmology. In diagnostic imaging, various ophthalmologic imaging devices are used. Ophthalmologic imaging devices include slit lamp microscopes, fundus cameras, scanning laser ophthalmoscopes (SLOs), optical coherence tomography (OCTs), and the like. In addition, various inspection devices and measuring devices such as a reflex meter, a keratometer, a tonometer, a specular microscope, a wavefront analyzer, and a microperimeter are also equipped with a function of photographing the anterior segment of the eye and the fundus.

One of the most widely and frequently used devices among these various ophthalmic devices is the slit lamp microscope. A slit lamp microscope is an ophthalmic apparatus for illuminating an eye to be inspected with slit light and observing or photographing an illuminated cross section with a microscope from the side.

For example, Patent Document 1 discloses a slit lamp microscope capable of performing anterior segment imaging while performing a combination of movement of an illumination system and an imaging system and movement of their focal points. According to this, it is possible to acquire a three-dimensional image in focus over a wide range of the anterior segment of the eye, while scanning the optical system in the optical axis direction (movement of the focal point) and scanning in the direction orthogonal to this (movement of the optical system). ) And it takes time and effort to shoot.

On the other hand, Patent Documents 2 and 3 disclose a technique for performing anterior segment imaging using the principle of Scheimpflug. The principle of Scheimpflug is a geometric rule regarding the orientation of the focal plane of the optical system when the lens plane is not parallel to the image plane, and there is a main plane of the lens (optical system) and an imaging plane of the imaging element. When they meet on one straight line, they insist that the objects in focus also meet on the same straight line.

According to this principle, if the slit lamp microscope is configured so that the surface (including the object surface) passing through the optical axis of the illumination system, the main surface of the imaging system, and the imaging surface of the image sensor intersect on the same straight line. , It is possible to obtain an image in which the entire object surface is in focus.

According to such a conventional Scheimpflug type slit lamp microscope, when observing and photographing the anterior segment from a direction inclined with respect to the optical axis of the eye to be inspected, the refractive index inside the eye to be inspected and the refractive index outside are Due to the difference, the light beam is refracted and the arrangement intended for the principle of Scheimpflug is broken. In addition, since there are individual differences in the shape and characteristics of the tissue of the eye to be inspected, individual differences also occur in the collapse of this arrangement. For example, the influence of individual differences in the shape (curvature) of the cornea and the refractive index of the anterior segment tissue can be considered.

Japanese Unexamined Patent Publication No. 2016-159073 Japanese Unexamined Patent Publication No. 2000-197607 Japanese Patent Application Laid-Open No. 2015-533322

An object of the present invention is to solve a problem of a Scheimpflug type slit lamp microscope caused by a difference in refractive index inside and outside the eye to be inspected.

An exemplary first embodiment is based on an illumination system that projects slit light onto the anterior segment of the eye to be inspected, an optical system that guides light from the anterior segment to which the slit light is projected, and the optical system. An imaging system including an imaging element that receives the guided light on an imaging surface, a surface including a focal point of the illumination system displaced by the refractive index of the tissue of the anterior segment of the eye, and a main body of the optical system. A slit lamp microscope in which a surface and the imaging surface are arranged so as to satisfy the shine-proof condition.

An exemplary second aspect is the slit lamp microscope of the first aspect, further including the illumination system and a moving mechanism for moving the imaging system, wherein the imaging system is the illumination system and the illumination system by the moving mechanism. A plurality of images of the anterior segment of the eye are acquired by repeatedly performing imaging in parallel with the movement of the imaging system.

An exemplary third aspect is the slit lamp microscope of the second aspect, further comprising a three-dimensional image construction unit that constructs a three-dimensional image based on the plurality of images.

An exemplary fourth aspect is the slit lamp microscope of the third aspect, further comprising a rendering section that renders the three-dimensional image to build a rendered image.

An exemplary fifth aspect is the slit lamp microscope according to any one of the second to fourth aspects, wherein at least one of the plurality of images or an image obtained by processing the same is subjected to a predetermined analysis process. Includes an analysis unit that applies.

An exemplary sixth aspect is the slit lamp microscope according to any one of the first to fifth aspects, wherein the deflection angle of the object surface due to the refractive index is in the range of 3 to 13 degrees.

An exemplary seventh aspect is the slit lamp microscope of the sixth aspect, wherein the deflection angle of the object surface due to the refractive index is in the range of 6 to 10 degrees.

An exemplary eighth aspect is the slit lamp microscope according to any one of the first to seventh aspects, wherein the deflection angle of the object surface due to the refractive index is the value of the radius of curvature of the cornea in a predetermined model eye and It is determined at least based on the value of the refractive index of the eye.

An exemplary ninth aspect is the slit lamp microscope according to any one of the first to fifth aspects, in which the deflection angle of the object surface due to the refractive index is determined by the optical axis of the illumination system and the photographing system. It is determined based on at least the angle formed by the optical axis.

An exemplary tenth aspect is the slit lamp microscope of the ninth aspect, wherein the angle is set to a value greater than 0 degrees and within the range of 60 degrees or less.

An exemplary eleventh aspect is the slit lamp microscope of the ninth or tenth aspect, in which the angle of deflection of the object surface by the refractive index is determined at least based on the angle and the radius of curvature of the cornea.

An exemplary twelfth aspect is the slit lamp microscope of the eleventh aspect, in which the value of the corneal radius of curvature is set based on a predetermined model eye.

An exemplary thirteenth aspect is the slit lamp microscope of the twelfth aspect, wherein the value of the corneal radius of curvature is in the range of 7.7 mm (mm) ± 0.5 mm based on the Gullstrand model eye. Is set to the value in.

An exemplary 14th aspect is the slit lamp microscope of the 9th or 10th aspect, in which the angle of deflection of the object surface by the refractive index is determined at least based on the angle and the refractive index of the eyeball.

An exemplary fifteenth aspect is the slit lamp microscope of the fourteenth aspect, wherein the value of the refractive index of the eyeball is set based on a predetermined model eye.

An exemplary 16th aspect is the slit lamp microscope of the 15th aspect, wherein the value of the refractive index of the eyeball is within the range of 1.336 ± 0.001 based on the Gullstrand model eye. Set.

An exemplary 17th aspect is the slit lamp microscope of the 9th or 10th aspect, wherein the deflection angle of the object surface due to the refractive index is at least based on the angle, the radius of curvature of the cornea and the refractive index of the eyeball. It is determined.

An exemplary eighteenth aspect is the slit lamp microscope of the seventeenth aspect, in which the value of the radius of curvature of the cornea and the value of the refractive index of the eyeball are each set based on a predetermined model eye.

An exemplary 19th aspect is the slit lamp microscope of the 18th aspect, wherein the value of the corneal radius of curvature is within the range of 7.7 mm ± 0.5 mm based on the Gullstrand model eye. The value of the refractive index of the eyeball is set to a value within the range of 1.336 ± 0.001.

An exemplary twentieth aspect is the slit lamp microscope of the nineteenth aspect, wherein the deflection angle is set to a value greater than 0 degrees and within the range of 11.09 degrees or less.

An exemplary 21st aspect is the slit lamp microscope according to any one of the 1st to 20th aspects, further comprising a first deflection mechanism for changing the direction of the optical axis of the photographing system.

An exemplary 22nd aspect is the slit lamp microscope of the 21st aspect, wherein the first deflection mechanism is substantially centered on the intersection of the object surface and the optical axis of the photographing system. Rotate the optical axis of.

An exemplary 23rd aspect is the slit lamp microscope of the 21st or 22nd aspect, wherein the image quality evaluation unit for analyzing the image of the eye to be inspected acquired by the photographing system and evaluating the image quality, and the above-mentioned It further includes a first deflection control unit that controls the first deflection mechanism based on at least the result of evaluation by the image quality evaluation unit.

An exemplary 24th aspect is a slit lamp microscope according to any one of the 21st to 23rd aspects, which measures the radius of curvature of the cornea by analyzing the image of the eye to be inspected acquired by the imaging system. Further includes a unit and a first determination unit that determines the target direction of the optical axis of the imaging system based on at least the result of measurement by the measurement unit, and the first deflection mechanism is the optical axis of the imaging system. The orientation is changed to the target orientation.

An exemplary 25th aspect is the slit lamp microscope according to any one of the 21st to 23rd aspects, the data receiving unit that receives the measurement data of the radius of curvature of the corneal membrane of the eye to be inspected, and the measurement. Further including a second determination unit that determines the target direction of the optical axis of the photographing system based on at least the data, the first deflection mechanism changes the direction of the optical axis of the photographing system to the target direction.

An exemplary 26th aspect is the slit lamp microscope according to any one of the 21st to 25th aspects, wherein in the photographing system, the first deflection mechanism changes the direction of the optical axis of the photographing system. Correspondingly, the imaging of the anterior segment is started.

An exemplary 27th aspect is the slit lamp microscope according to any one of the 1st to 20th aspects, further comprising a second deflection mechanism for changing the direction of the optical axis of the illumination system.

An exemplary 28th aspect is the slit lamp microscope of the 27th aspect, wherein the second deflection mechanism of the illumination system is centered on the intersection of the cornea of the eye to be inspected and the optical axis of the illumination system. Rotate the optical axis.

An exemplary 29th aspect is the slit lamp microscope of the 27th or 28th aspect, wherein the image quality evaluation unit for analyzing the image of the eye to be inspected acquired by the photographing system and evaluating the image quality, and the above-mentioned It further includes a second deflection control unit that controls the second deflection mechanism based on at least the result of evaluation by the image quality evaluation unit.

An exemplary thirty-third aspect is a slit lamp microscope according to any one of the 27th to 29th aspects, which measures the radius of curvature of the cornea by analyzing the image of the eye to be inspected acquired by the imaging system. Further includes a unit and a third determination unit that determines the target direction of the optical axis of the illumination system based on at least the result of measurement by the measurement unit, and the second deflection mechanism is the optical axis of the illumination system. The orientation is changed to the target orientation.

An exemplary thirty-first aspect is the slit lamp microscope according to any one of the 27th to 29th aspects, the data receiving unit that receives the measurement data of the radius of curvature of the corneal membrane of the eye to be inspected, and the measurement. Further including a fourth determination unit that determines the target orientation of the optical axis of the illumination system based on at least the data, the second deflection mechanism changes the orientation of the optical axis of the illumination system to the target orientation.

An exemplary 32nd aspect is the slit lamp microscope according to any one of the 27th to 31st aspects, wherein in the photographing system, the second deflection mechanism changes the direction of the optical axis of the illumination system. Correspondingly, the imaging of the anterior segment is started.

According to the exemplary embodiment, it is possible to avoid deviation from the Scheimpflug condition due to the difference in the refractive index inside and outside the eye to be inspected.

It is a schematic diagram for demonstrating the background of an exemplary embodiment. It is a schematic diagram for demonstrating the background of an exemplary embodiment. It is a schematic diagram for demonstrating the background of an exemplary embodiment. It is a schematic diagram for demonstrating the background of an exemplary embodiment. It is a schematic diagram for demonstrating the background of an exemplary embodiment. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is a flowchart which shows the operation of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is a flowchart which shows the operation of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is a flowchart which shows the operation of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic which shows the structure of the slit lamp microscope which concerns on an exemplary aspect. It is a flowchart which shows the operation of the slit lamp microscope which concerns on an exemplary aspect. It is the schematic for demonstrating the slit lamp microscope which concerns on an exemplary aspect. It is the schematic for demonstrating the slit lamp microscope which concerns on an exemplary aspect. It is the schematic for demonstrating the slit lamp microscope which concerns on an exemplary aspect. It is the schematic for demonstrating the slit lamp microscope which concerns on an exemplary aspect. It is the schematic for demonstrating the slit lamp microscope which concerns on an exemplary aspect.

An exemplary embodiment will be described in detail with reference to the drawings. It should be noted that the disclosure items of the documents cited in the present specification and other known techniques can be combined with the embodiments. Hereinafter, the background and outline of the embodiment will be briefly described first, and then some exemplary embodiments will be described.

<Background and outline>
As shown in FIG. 1A, the object plane (Subject Plane) SP to which the lens LN is focused is imaged as an image plane (Image Plane) IP at a position calculated by the position to the lens LN and the focal length of the lens LN. It is known to be (Newton's imaging formula). Further, as shown in FIG. 1B, when the object surface SP is displaced by a distance Δ in a certain direction, the square of the horizontal magnification β (that is, the vertical magnification) of the optical system is integrated with the distance Δ (Δ × β ² ). It is known that the image plane IP is also displaced in the same direction.

Based on Newton's imaging formula when the displacement of the paraboloid is taken into consideration, considering the case where the paraboloid SP is tilted with respect to the optical axis of the lens LN, the principle of shine proof is as shown in FIG. 1C. It is claimed that the plane PL1 including the paraboloid SP, the main surface PL2 (main plane) of the lens LN, and the plane PL3 including the image plane IP intersect at the same straight line CL.

Therefore, when the conditions shown in FIG. 1C are satisfied, theoretically, as shown in FIG. 1D, the eyeball optical axis Ex of the eye E to be inspected and the object surface SP are matched, that is, the main surface. By injecting the slit light SL into the eye E to be inspected along the plane PL1 that intersects with the same straight line CL as each of the PL2 and the plane PL3, a slit lamp microscope capable of focusing on the entire object surface SP and taking an image is realized. ..

However, the refraction of the slit light SL is caused by the difference in the refractive index inside and outside the eye E to be inspected (difference between the refractive index of air and the refractive index of the corneum, the difference in the refractive index at the boundary of the eyeball tissue, etc.). The physical surface SP is not accurate when is ignored, and a deviation from the shineproof condition occurs.

For example, as shown in FIG. 1E, the refraction on the anterior surface of the cornea is taken into consideration when the image is taken at an angle α with respect to the incident direction of the slit light SL corresponding to the optical axis of the eye (also indicated by the symbol SL). Then, the focal position FP1 of the lens LN located at the apex of the cornea does not displace, but the (exemplary) focal positions FP2 and FP3 located inside the eye E to be examined move to the positions indicated by the symbols FP2'and FP3', respectively. .. Therefore, the paraboloid that satisfies the Scheimpflug condition is not the original paraboloid SP that coincides with the optical axis of the eyeball Ex, but is located on a plane that passes through a plurality of focal positions FP1, FP2'and FP3'that take refraction into consideration. The paraboloid SP'is adopted.

Further, in order to realize the object surface SP', considering the angle between the object surface SP' and the object surface SP (optic axis of a crystal of the eye) and refraction at least on the anterior surface of the cornea, the original incident direction SL It can be seen from this that the slit light should be incident from the direction SL'inclined by the angle Δθ. As an example, assuming that the eye to be inspected is a sphere, the imaging angle is α = 30 degrees, and the calculation is performed using the radius of curvature of the cornea of the Bullstrand model eye = 7.7 mm and the refractive index of the eyeball = 1.336. The inclination angle of the object surface SP'with respect to the object surface SP is about 6 degrees, and the angle of the incident direction SL'with respect to the incident direction SL is about 8 degrees.

Considering the width of individual differences in these parameters and the type of model eye to be referred to, the deflection angle Δθ of the object surface due to the refractive index of the eye E to be inspected is included in the range of 3 to 13 degrees. It may be included in the range of 6 to 10 degrees. The type of model eye that can be referred to for determining the deflection angle Δθ is arbitrary. For example, the Gullstrand model eye and Navarro model disclosed in Japanese Patent Application Laid-Open No. 2012-93522 and Japanese Patent Application Laid-Open No. 2017-526517. It may be any of an eye, a Liou-Brennan model eye, a Badal model eye, an Arizona model eye, an Indiana model eye, any standardized model eye, and a model eye equivalent to any of these.

Further, in the above example, the deflection angle Δθ is determined at least based on the value of the radius of curvature of the cornea and the value of the refractive index of the eye in a predetermined model eye, but the method for determining the deflection angle Δθ is not limited to this. For example, it is possible to determine the deflection angle Δθ in addition to or instead of the radius of curvature of the cornea using the values of other parameters. Alternatively, it is also possible to use information other than the model eye. For example, it is possible to determine the deflection angle Δθ using the measurement data of the eye E to be inspected. Some examples will be described later.

<About slit lamp microscope>
In general, slit lamp microscopes are widely used in various medical facilities. The installation location of the slit lamp microscope according to the embodiment is not limited to the medical facility, and the situation or environment in which the expertise holder regarding the device is not on the side, or the expertise holder monitors, instructs, and operates from a remote location. It may be used in situations and environments where it can be used. Further, the slit lamp microscope according to the embodiment may be portable. Examples of facilities in which the slit lamp microscope according to the embodiment is installed include, in addition to medical facilities, opticians, optometrists, health examination venues, examination venues, patients' homes, welfare facilities, public facilities, examination vehicles, and the like. is there.

The slit lamp microscope according to the embodiment is an ophthalmologic imaging device (or more generally, a medical device) having at least an observation / imaging function (slit lamp microscope function) using slit light, and has other imaging functions (modality). Further may be provided. Examples of other modality include fundus cameras, SLOs, OCTs and the like.

The slit lamp microscope according to the embodiment may further have a function of measuring the characteristics of the eye to be inspected. Examples of measurement functions include visual acuity test, refraction measurement, intraocular pressure measurement, corneal endothelial cell measurement, aberration measurement, and visual field measurement.

The slit lamp microscope according to the embodiment may further include an application for analyzing captured images and measurement data. Further, the slit lamp microscope according to the embodiment may further have a function for treatment or surgery. Examples are photocoagulation therapy and photodynamic therapy.

Hereinafter, some exemplary embodiments of the embodiments will be described. It is possible to combine any two or more of these exemplary embodiments. Further, it is possible to combine any known technique or to perform modification (addition, replacement, etc.) based on any known technique for each or a combination of two or more of these exemplary embodiments.

In the embodiment illustrated below, the "processor" is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (for example, a SPLD Digital Device), a programmable logic device (for example, a SPLD) , CPLD (Complex Programmable Logical Device), FPGA (Field Programmable Gate Array)) and the like. The processor realizes the function according to the embodiment by reading and executing a program or data stored in a storage circuit or a storage device, for example.

The configuration of the slit lamp microscope according to the exemplary embodiment will be described. First, the direction is defined as follows. When the optical system of the slit lamp microscope is arranged in front of the eye to be inspected (neutral position), the direction from the lens (objective lens) located closest to the eye to be inspected in the optical system toward the eye to be inspected is forward (or). The depth direction, the depth direction, and the Z direction), and the opposite direction is the rear direction (−Z direction). Further, the horizontal direction orthogonal to the Z direction is defined as the left-right direction (or the lateral direction, the ± X direction). Further, the direction orthogonal to both the Z direction and the X direction is defined as the vertical direction (or the vertical direction, ± Y direction). The XYZ coordinate system is, for example, a three-dimensional Cartesian coordinate system defined as a right-handed system (or left-handed system).

Also, the observation imaging system of the slit lamp microscope is rotatable in at least a horizontal direction, a radial direction is a direction along the observation imaging system of the optical axis (the observation imaging optical axis) and r ₁ direction, the direction of rotation θ _One direction. Similarly, the illumination system of the slit lamp microscope is rotatable, a radial direction is a direction along the illumination system of the optical axis (illumination optical axis) and r ₂ direction, and the direction of rotation and theta ₂ direction. For example, the positive direction in the radial direction is the direction from the objective lens toward the eye to be inspected, and the positive direction in the rotation direction is the counterclockwise direction when viewed from above. The direction of rotation is defined, for example, with reference to the Z direction (that is, the Z direction is defined as a rotation angle of 0 degrees). When the observation imaging system is placed in the neutral position (that is, when θ ₁ = 0 degrees), the r ₁ direction coincides with the Z direction. Similarly, when the lighting system is located in the neutral position (that is, when θ ₂ = 0 degrees), the r ₂ direction coincides with the Z direction. At least one of the illumination system and the observation imaging system may be rotatable in the vertical direction. In this case as well, the radial direction and the rotational direction are similarly defined.

FIG. 2 shows an external configuration of a slit lamp microscope according to an exemplary embodiment. A computer 100 is connected to the slit lamp microscope 1. The computer 100 performs various types of information processing (control processing, arithmetic processing, etc.). The computer 100 may be connected to the slit lamp microscope 1 via a communication line, and may be, for example, a server on a network. Alternatively, the computer 100 may be a part of the slit lamp microscope 1.

The slit lamp microscope 1 is placed on the table 2. The base 4 is configured to be three-dimensionally movable via, for example, the moving mechanism unit 3. The base 4 is moved by tilting the operation handle 5. Alternatively, the moving mechanism unit 3 includes an actuator.

On the upper surface of the base 4, a support portion 15 for supporting the observation imaging system 6 and the illumination system 8 is provided. A support arm 16 that supports the observation imaging 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 lighting system 8 is rotatably attached to the upper portion of the support arm 16 in the left-right direction. The support arms 16 and 17 are rotatable independently of each other and coaxially with each other.

The observation imaging system 6 is moved by rotating the support arm 16. The lighting system 8 is moved by rotating the support arm 17. Each of the support arms 16 and 17 is rotated by an electrical mechanism. The moving mechanism unit 3 is provided with a mechanism for rotating the support arm 16 and a mechanism for rotating the support arm 17. The observation imaging system 6 can also be moved by manually rotating the support arm 16. Similarly, the lighting system 8 can be moved by manually rotating the support arm 17.

The illumination system 8 irradiates the eye E to be inspected with illumination light. As described above, the lighting system 8 can be rotated in the left-right direction. Further, the lighting system 8 may be configured to be rotatable in the vertical direction. That is, it may be configured so that the elevation angle and the depression angle of the lighting system 8 can be changed. By such a swing operation of the illumination system 8, the projection direction of the illumination light on the eye E to be inspected is changed.

The observation imaging system 6 has a pair of left and right optical systems that guide the return light of the illumination light projected on the eye E to be inspected. This optical system is housed in the lens barrel main body 9. The end of the lens barrel body 9 is the eyepiece 9a. The examiner observes the eye E to be inspected 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. Further, the observation imaging system 6 may be configured to be rotatable in the vertical direction. That is, it may be configured so that the elevation angle and the depression angle of the observation imaging system 6 can be changed. By such a swing operation of the observation and imaging system 6, the direction of observing the eye E to be inspected and the direction of imaging can be changed.

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

A magnification operation knob 11 for changing the magnification is arranged on the side surface of the lens barrel main body 9. Further, an imaging device 13 for photographing the eye E to be inspected is connected to the lens barrel main body 9. The image pickup device 13 includes an image pickup element. The image sensor is a photoelectric conversion element that detects light and outputs an image signal (electric signal). The image signal is input to the computer 100. As the image sensor, for example, a CCD image sensor, a CMOS image sensor, or the like is used.

A mirror 12 that reflects the illumination light flux output from the illumination system 8 toward the eye E to be inspected is arranged below the illumination system 8.

FIG. 3 shows a configuration example of the optical system of the slit lamp microscope 1. As described above, the slit lamp microscope 1 includes an observation imaging system 6 and an illumination system 8.

The observation imaging system 6 includes a pair of left and right optical systems. The configurations of the left and right optical systems are almost the same, enabling binocular observation of the eye E to be inspected. Note that FIG. 3 shows only one of the left and right optical systems of the observation imaging system 6. The observation imaging system 6 is not limited to the binocular optical system, and may be a monocular optical system. Reference numeral O1 indicates the optical axis of the observation imaging system 6.

Each of the left and right optical systems of the observation and photographing system 6 includes an objective lens 31, a variable magnification optical system 32, a beam splitter 34, an imaging lens 35, a prism 36, and an eyepiece lens 37. Here, the beam splitter 34 is provided on one or both of the left and right optical systems. The eyepiece lens 37 is provided in the eyepiece portion 9a. Reference numeral P indicates an imaging position of light guided to the eyepiece lens 37. The symbol Ec indicates the cornea of the eye E to be inspected. The symbol Eo indicates the examiner's eye.

The variable magnification optical system 32 includes a plurality of (for example, three) variable magnification lenses 32a, 32b, and 32c. In the present embodiment, a plurality of variable magnification lens groups that can be selectively inserted into the optical path of the observation imaging system 6 are provided. These variable magnification lens groups correspond to different magnifications. A variable magnification lens group arranged in the optical path of the observation imaging system 6 is used as the variable magnification optical system 32. By selectively inserting the variable magnification lens group in this way, the magnification (angle of view) of the observation image or the captured image of the eye E to be inspected can be changed. The magnification is changed, that is, the variable magnification lens group arranged in the optical path of the observation imaging system 6 is switched by operating the magnification operation knob 11. Further, the magnification can be changed electrically by using a switch (not shown) or the like.

The beam splitter 34 divides an optical path of light traveling along the optical axis O1 into an optical path located on an extension of the optical axis O1 and an optical path orthogonal to the optical axis O1. The light incident on the optical path located on the extension of the optical axis O1 is guided to the examiner's eye Eo via the imaging lens 35, the prism 36, and the eyepiece lens 37. The prism 36 translates the traveling direction of light upward.

On the other hand, the light incident on the optical path orthogonal to the optical axis O1 is guided to the image sensor 43 of the image pickup device 13 via the condensing lens 41 and the mirror 42. That is, the observation imaging system 6 guides the return light from the eye E to be examined to the imaging device 13. The image sensor 43 detects this return light and generates an image signal GS. The image pickup apparatus 13 is provided on one or both of the left and right optical systems.

The observation imaging system 6 includes a focusing mechanism 40 for changing the focus position (focus). The focusing mechanism 40 moves the objective lens 31 along the optical axis O1. The movement of the objective lens 31 is performed automatically and / or manually. When the objective lens 31 is automatically moved, for example, the computer 100 uses a known focus adjustment method (for example, a phase difference detection method, a contrast detection method, etc.) to set the focus position based on the return light from the eye E to be inspected. Can be sought. Further, the computer 100 can control the actuator so that the objective lens 31 moves along the optical axis O1 to the obtained focus position. On the other hand, when the objective lens 31 is manually moved, the actuator moves the objective lens 31 along the optical axis O1 in response to an operation by the user.

The observation imaging system 6 may include a first focusing lens arranged at a position on the optical axis O1 between the objective lens 31 and the image sensor 43. In this case, the focusing mechanism 40 changes the focus position of the observation imaging system 6 by moving the first focusing lens along the optical axis O1. Further, the whole (or a part) of the observation imaging system 6 may be configured to be movable along the optical axis O1. In this case, the focusing mechanism 40 changes the focus position of the observation imaging system 6 by moving the entire observation imaging system 6 along the optical axis O1. Similar to the case of moving the objective lens 31, the movement of the first focusing lens or the observation imaging system 6 by the focusing mechanism 40 is performed automatically or manually.

In this exemplary embodiment, an observation imaging system 6 capable of both observation through an eyepiece and imaging by an image sensor is adopted. However, the slit lamp microscope according to some exemplary embodiments may include an imaging system capable of only imaging with an image sensor.

The illumination system 8 includes an illumination light source 51, a condensing lens 52, a slit forming portion 53, and an objective lens 54. Reference numeral O2 indicates the optical axis of the illumination system 8.

The illumination light source 51 outputs illumination light. A plurality of light sources may be provided in the illumination system 8. For example, both a light source that outputs constant light (for example, a halogen lamp, a light emitting diode (LED), etc.) and a light source that outputs flash light (for example, a xenon lamp, an LED, etc.) can be provided as the illumination light source 51. Further, a light source for observing the anterior segment of the eye and a light source for observing the posterior segment of the eye may be provided separately. For example, the illumination light source 51 includes a visible light source that outputs visible light. The illumination light source 51 may include an infrared light source that outputs infrared light (for example, light having a center wavelength of 800 nm to 1000 nm).

The slit forming portion 53 is used to generate slit light. The slit forming portion 53 has a pair of slit blades. By changing the interval (slit width) of these slit blades, the width of the generated slit light can be changed. Further, the direction of the slit light can be changed by integrally rotating the pair of slit blades. The configuration of the slit forming portion 53 is not limited to the mode including the pair of slit blades, and may be any other mode.

The lighting system 8 includes a focusing mechanism 50 for changing the focus position (focus). The focusing mechanism 50 moves the objective lens 54 along the optical axis O2. The movement of the objective lens 54 is performed automatically and / or manually. When the objective lens 54 is automatically moved, for example, the computer 100 can obtain the focus position by analyzing the image in which the image based on the return light from the eye E to be inspected is drawn. Further, the computer 100 can control the actuator so that the objective lens 54 moves along the optical axis O2 to the obtained focus position. On the other hand, when the objective lens 54 is manually moved, the actuator moves the objective lens 54 along the optical axis O2 in response to an operation by the user.

The illumination system 8 may include a second focusing lens arranged at a position on the optical axis O2 between the objective lens 54 and the slit forming portion 53. In this case, the focusing mechanism 50 changes the focus position of the slit light by moving the second focusing lens along the optical axis O2. Further, the entire (or a part) of the lighting system 8 may be configured to be movable along the optical axis O2. In this case, the focusing mechanism 50 changes the focus position of the slit light by moving the entire illumination system 8 along the optical axis O2. Similar to the case of moving the objective lens 54, the movement of the second focusing lens or the illumination system 8 by the focusing mechanism 50 is performed automatically or manually.

Although not shown in FIG. 3, a mirror 12 that reflects the illumination luminous flux output from the illumination system 8 toward the eye E to be inspected is arranged on the optical axis O2. Typically, the lighting system 8 and the mirror 12 are configured to rotate integrally.

In some exemplary embodiments described below, the description will be made with reference to the slit lamp microscope 1 unless otherwise specified. However, the slit lamp microscope applicable to these exemplary embodiments or other embodiments is not limited to this.

<First aspect>
The slit lamp microscope according to the first aspect will be described. A configuration example of the slit lamp microscope 200 according to this embodiment is shown in FIGS. 4 and 5.

As shown in FIG. 4, the slit lamp microscope 200 includes a moving mechanism 60 in addition to the same imaging system (observation imaging system) 6, the illumination system 8, and the computer 100 as the slit lamp microscope 1, respectively. The computer 100 includes a control unit 110 and a data processing unit 120. The data processing unit 120A shown in FIG. 5 shows an example of the data processing unit 120. The data processing unit 120 (120A) includes a three-dimensional image construction unit 121, a rendering unit 122, and an analysis unit 123.

The slit lamp microscope 200 may be a single device or a system including two or more devices. For example, in some embodiments, the slit lamp microscope 200 is a communication device that is responsible for communication between a main unit including an illumination system 8, an imaging system 6, and a moving mechanism 60, a computer 100, and the main unit and the computer 100. And include. Also, in some embodiments, the slit lamp microscope 200 includes a similar main unit (and computer 100) as well as a remote control computer that can access the main unit (or computer 100) via a communication line.

The illumination system 8 irradiates the anterior segment of the eye E to be inspected with slit light. Reference numeral O2 indicates an optical axis (illumination optical axis) of the illumination system 8. The illumination system 8 can change, for example, the width, length, and direction of the slit light. The length of the slit light is the cross-sectional dimension of the slit light in a direction orthogonal to the cross-sectional width direction of the slit light corresponding to the slit width. The slit width and the slit length are typically expressed as the dimensions of the projected image of the slit light onto the anterior segment of the eye or as the dimensions of the slit formed by the slit forming portion 53.

The photographing system 6 photographs the anterior segment of the eye that is irradiated with the slit light from the illumination system 8. Reference numeral O1 indicates an optical axis (photographing optical axis) of the photographing system 6. The photographing system 6 includes an optical system 6a and an image sensor 43.

The optical system 6a guides the light from the anterior segment of the eye to be inspected E irradiated with the slit light to the image sensor 43. The image sensor 43 receives the light guided by the optical system 6a on the image pickup surface.

The light guided by the optical system 6a (that is, the light from the anterior segment of the eye E to be inspected) includes the return light of the slit light irradiating the anterior segment of the eye, and may further include other light. Examples of return light are reflected light, scattered light, and fluorescence. As an example of other light, there is light (indoor light, sunlight, etc.) from the installation environment of the slit lamp microscope 200.

The lighting system 8 and the photographing system 6 according to this aspect function as a Scheimpflug camera. That is, the structure of the lighting system 8 and the photographing system 6 is configured so that the object surface SP determined based on the lighting system 8, the main surface of the optical system 6a, and the imaging surface of the image pickup device 43 satisfy the so-called Scheimpflug condition. And placement is determined.

More specifically, as shown in FIG. 1E, the object surface SP including the focal point of the illumination system 8 displaced by the refractive index of the tissue of the anterior segment, the main surface of the optical system 6a, and the image pickup surface of the image sensor 43. The configurations and arrangements of the lighting system 8 and the photographing system 6 are determined so that the two intersect on the same straight line. As a result, it is possible to focus on the entire surface SP and perform shooting. As described above, the conventional Scheimpflug type slit lamp microscope does not consider the displacement of the focal point of the illumination system due to the refractive index of the tissue of the anterior segment of the eye, so that the entire object surface SP is focused and photographed. Cannot be done.

The range of the object surface SP is set wider than the range from, for example, the anterior surface of the cornea to the crystalline lens (typically the posterior surface). However, the range of the physical surface SP is not limited to this. Further, the object surface SP can be aligned with respect to a predetermined imaging target range (for example, a range from the anterior surface of the cornea to the posterior surface of the crystalline lens) of the eye E to be inspected. The operation for this alignment may include, for example, a known alignment operation.

In order to satisfy the Scheimpflug condition, typically, the configuration and arrangement of the elements included in the lighting system 8, the configuration and arrangement of the elements included in the photographing system 6, and the lighting system 8 and the photographing system 6 Design, adjustment, processing, etc. related to the relative position are performed.

As a parameter indicating the relative position between the illumination system 8 and the photographing system 6, for example, there is an angle (imaging angle) formed by the illumination optical axis O2 and the photographing optical axis O1. In the conventional shine-proof type slit lamp microscope, the illumination optical axis O2 and the eyeball optical axis Ex coincide with each other, but in the slit lamp microscope 200 according to this embodiment, the eyeball optical axis Ex and the illumination optical axis O2 are aligned. It has an angle (deflection angle) Δθ.

The deflection angle Δθ is determined at least based on the refractive index of the anterior segment of the eye. This refractive index may be a measured value of the refractive index of the eye E to be inspected, or may be a standard value. An example of a standard value is the above-mentioned model eye value.

The deflection angle Δθ may be further determined based on other eye parameters. For example, there are the radius of curvature of the cornea, the thickness of the cornea, the depth of the anterior chamber, the radius of curvature of the front surface of the crystalline lens, the thickness of the crystalline lens, and the radius of curvature of the posterior surface of the crystalline lens. Further, the deflection angle Δθ may depend on the photographing angle formed by the illumination optical axis O2 and the photographing optical axis O1.

In this way, the deflection angle Δθ may be set to a value within the range of 3 to 13 degrees according to individual differences in eyeball parameters, the type of model eye to be referred to, the shooting angle, and the like, and further 6 to 6 to 13 degrees. It may be set to a value within the range of 10 degrees. The value of the deflection angle Δθ is not limited to these.

The moving mechanism 60 moves the lighting system 8 and the photographing system 6. In this embodiment, the moving mechanism 60 can integrally move the lighting system 8 and the photographing system 6 in the left-right direction. When the lighting system 8 and the photographing system 6 are integrally moved in the left-right direction, the longitudinal direction of the slit light is typically along the up-down direction. That is, in a typical control example, the direction of the slit light (longitudinal direction) and the moving direction of the illumination system 8 and the photographing system 6 are orthogonal to each other. As a result, the eye E to be inspected can be scanned with the slit light.

Further, the moving mechanism 60 can move the lighting system 8 and the photographing system 6 independently of each other. For example, the moving mechanism 60 can independently rotate the lighting system 8 in the horizontal direction and the photographing system 6 in the horizontal direction. Thereby, the shooting angle formed by the illumination optical axis O2 and the shooting optical axis O1 can be changed.

When the configuration illustrated in FIG. 2 is adopted, the moving mechanism 60 includes an actuator that rotates the support arm 16 that supports the imaging system (observation imaging system) 6 in the left-right direction and a support arm 17 that supports the illumination system 8. Includes an actuator that rotates in the left-right direction. As a result, the lighting system 8 and the photographing system 6 can rotate independently of each other and coaxially with each other.

The movement mode of the illumination system 8 by the movement mechanism 60 is not limited to the above example, and the movement mode of the photographing system 6 is not limited to the above example. For example, the moving mechanism 60 may be configured so that the lighting system 8 and the photographing system 6 can be integrally moved in an arbitrary direction. Further, the moving mechanism 60 may be configured so that the relative position between the lighting system 8 and the photographing system 6 can be arbitrarily changed.

The control unit 110 provided in the computer 100 controls each unit of the slit lamp microscope 200. For example, the control unit 110 controls the elements of the lighting system 8, the elements of the photographing system 6, the moving mechanism 60, the data processing unit 120, and the like.

The control unit 110 includes one or more processors, one or more main storage devices, one or more auxiliary storage devices, and the like. A control program or the like is stored in the auxiliary storage device. The control program and the like may be stored in a computer or a storage device accessible to the slit lamp microscope 200. The function of the control unit 110 is realized by the cooperation between software such as a control program and hardware such as a processor.

The control unit 110 can apply the following controls to the lighting system 8, the photographing system 6, and the moving mechanism 60 in order to scan the three-dimensional region of the eye E to be inspected with the slit light.

First, the control unit 110 controls the moving mechanism 60 for arranging the lighting system 8 and the photographing system 6 at a predetermined scan start position (alignment control). The scan start position is, for example, a position corresponding to the end (first end) of the cornea of the eye E to be inspected in the left-right direction, or a position further away from the optical axis of the eye Ex. Hereinafter, some exemplary embodiments of the alignment control will be described, but the alignment control is not limited thereto.

Alignment control includes, for example, control of arranging the illumination system 8 so that the angle of the illumination optical axis O2 with respect to the eyeball optical axis Ex of the eye E to be examined is equal to a predetermined deflection angle (Δθ), and illumination arranged in this way. Control to arrange the photographing system 6 so that the angle of the photographing optical axis O1 with respect to the illumination optical axis O2 of the system 8 becomes equal to a predetermined photographing angle (α−Δθ), and the illumination system 8 and the photographing system arranged in this way. Includes control to move 6 integrally to a predetermined scan start position.

In another example, the alignment control is a control in which the illumination system 8 and the imaging system 6 are arranged so that the angle formed by the illumination optical axis O2 and the imaging optical axis O1 is equal to a predetermined imaging angle (α−Δθ). The illumination system 8 is arranged so that the illumination optical axis O2 of the illumination system 8 arranged at such a relative position with respect to the photographing system 6 forms a predetermined deflection angle Δθ with respect to the eyeball optical axis Ex of the eye E to be examined. The control includes a control and a control for integrally moving the lighting system 8 and the photographing system 6 arranged in this way to a predetermined scan start position.

In yet another example, the alignment control is a control in which the illumination system 8 and the imaging system 6 are arranged so that the angle formed by the illumination optical axis O2 and the imaging optical axis O1 is equal to a predetermined imaging angle (α). Control to integrally move the illumination system 8 and the imaging system 6 arranged in such a manner to a predetermined scan start position so that the illumination optical axis O2 coincides with the eyeball optical axis Ex of the eye E to be inspected, and to the eyeball optical axis Ex. It includes a control for moving the illumination system 8 so as to rotate the illumination optical axis O2 arranged so as to coincide with the above by a predetermined deflection angle Δθ.

After the illumination system 8 and the photographing system 6 are arranged at the scan start position, the control unit 110 controls the illumination system 8 to start irradiating the eye E to be examined with slit light (slit light irradiation control). The slit light irradiation control may be performed before the execution of the alignment control or during the execution of the alignment control. The illumination system 8 typically irradiates continuous light as slit light, but intermittent light (pulse light) may be irradiated as slit light. Further, although the illumination system 8 typically irradiates visible light as slit light, infrared light may be irradiated as slit light.

At the same time as the start of irradiation of the slit light, or at an arbitrary timing before or after that, the control unit 110 controls the photographing system 6 to start the moving image photographing of the eye E to be inspected (imaging control). That is, the photographing system 6 acquires a plurality of images of the anterior segment of the eye E to be inspected by repeatedly performing imaging in parallel with the movement of the lighting system 8 and the photographing system 6 by the moving mechanism 60. Movie shooting is performed at a predetermined repetition rate.

After executing the alignment control, the slit light irradiation control, and the photographing control, the control unit 110 controls the moving mechanism 60 to start the movement of the lighting system 8 and the photographing system 6 (movement control). The lighting system 8 and the photographing system 6 are integrally moved by the movement control. That is, the lighting system 8 and the photographing system 6 are moved while maintaining the relative positions (for example, the photographing angle α−Δθ) between the lighting system 8 and the photographing system 6. The illumination system 8 and the photographing system 6 are moved from the above-mentioned scan start position to a predetermined scan end position. The scan end position is, for example, the position corresponding to the end (second end) of the cornea opposite to the first end in the left-right direction, or from the eyeball optical axis Ex. It is a distant position. The scan range is the range from the scan start position to the scan end position.

An exemplary embodiment of scanning with slit light is to irradiate the eye E with slit light having a horizontal direction as a width direction and a vertical direction as a longitudinal direction, and move the illumination system 8 and the photographing system 6 in the horizontal direction. At the same time, moving image shooting by the shooting system 6 is executed.

Here, the length of the slit light (that is, the dimension of the slit light in the vertical direction) is set to, for example, the diameter of the cornea or more. That is, the length of the slit light is set to be equal to or larger than the corneal diameter. Further, as described above, the moving distance (that is, the scanning range) of the lighting system 8 and the photographing system 6 is set to be equal to or larger than the corneal diameter in the left-right direction. As a result, at least the entire cornea of the eye E to be inspected can be scanned with slit light. A wider scan range can be applied when scanning the sclera, scanning the iris, scanning the angle, and the like. The scan range is not limited to these exemplary modes, and can be arbitrarily set according to the part to be imaged and the like.

By such a scan, a plurality of cross-sectional images having different irradiation positions of the slit light can be obtained. In other words, a moving image is obtained in which the irradiation position of the slit light moves in the horizontal direction. The cross section shown by each cross-sectional image includes the paraboloid SP shown in FIG. The focus of the shooting system 6 is on the entire surface SP. The object surface SP includes, for example, the range from the anterior surface of the cornea to the posterior surface of the crystalline lens. In this case, a clear (focused, high quality, fine) image of the three-dimensional region extending from the anterior surface of the cornea to the posterior surface of the crystalline lens can be obtained.

The data processing unit 120 executes various data processing. The data to be processed may be either the data acquired by the slit lamp microscope 200 or the data input from the outside. For example, the data processing unit 120 can process the images acquired by the lighting system 8 and the photographing system 6.

The data processing unit 120 includes one or more processors, one or more main storage devices, one or more auxiliary storage devices, and the like. A data processing program or the like is stored in the auxiliary storage device. The data processing program and the like may be stored in a computer or a storage device accessible to the slit lamp microscope 200. The function of the data processing unit 120 is realized by the cooperation between software such as a data processing program and hardware such as a processor.

As described above, the data processing unit 120A, which is an exemplary embodiment of the data processing unit 120, includes a three-dimensional image construction unit 121, a rendering unit 122, and an analysis unit 123 (see FIG. 5).

The three-dimensional image construction unit 121 constructs a three-dimensional image based on a plurality of images of the eye E to be inspected acquired by using the illumination system 8 and the photographing system 6. In this aspect, the three-dimensional image construction unit 121 can construct a three-dimensional image based on a plurality of cross-sectional images collected by scanning the eye E to be inspected with slit light.

A three-dimensional image is an image (image data) in which pixel positions are defined by a three-dimensional coordinate system. Examples of 3D images include stack data and volume data. The stack data is constructed by embedding a plurality of two-dimensional images (for example, a plurality of cross-sectional images) in a single three-dimensional coordinate system according to their positional relationship. Volume data is also called voxel data, and is constructed by applying voxelization processing to stack data, for example.

An example of the process of constructing a three-dimensional image will be described. The three-dimensional image construction unit 121 can extract a partial image from each of the plurality of images and construct a three-dimensional image from the extracted plurality of partial images. Here, the partial image is, for example, an image corresponding to the object surface SP (object surface image) or an image including at least a part of the object surface image. According to this example, for example, it is possible to construct a clear (focused, high-quality, fine) three-dimensional image from the anterior surface of the cornea to the posterior surface of the crystalline lens.

The rendering unit 122 constructs a new image (rendered image) by rendering the three-dimensional image constructed by the three-dimensional image construction unit 121.

Rendering can be any process, including, for example, 3D computer graphics. 3D computer graphics is an image with a three-dimensional effect by converting virtual three-dimensional objects (three-dimensional images such as stack data and volume data) in the three-dimensional space defined by the three-dimensional coordinate system into two-dimensional information. It is a calculation method to create.

Examples of rendering are volume rendering, maximum value projection (MIP), minimum value projection (MinIP), surface rendering, multi-section reconstruction (MPR), projection image construction, shadowgram construction, and section image obtained with a slit lamp microscope. There is a reproduction of. Further, the rendering unit 122 may be able to execute arbitrary processing together with such rendering.

The rendering unit 122 can identify a region in the three-dimensional image corresponding to a predetermined portion of the eye E to be inspected. For example, the rendering unit 122 corresponds to a region corresponding to the cornea, a region corresponding to the anterior surface of the cornea, a region corresponding to the posterior surface of the cornea, a region corresponding to the crystalline lens, a region corresponding to the anterior surface of the crystalline lens, a region corresponding to the posterior surface of the crystalline lens, and an iris. It is possible to specify the area to be rendered, the area corresponding to the corner, and the like. Known image processing such as segmentation, edge detection, threshold value processing, filtering, and labeling is applied to such image region identification. Further, the image region may be specified by using machine learning using a convolutional neural network or the like.

The 3D image is typically stack data or volume data. The designation of the cross section for the three-dimensional image is performed manually or automatically. For example, the above-mentioned image area identification is applied to the automatic designation of the cross section.

On the other hand, when the cross section of the three-dimensional image is manually specified, the rendering unit 122 renders the three-dimensional image and constructs a display image for manually specifying the cross section. The display image is typically an image showing the entire part to be observed, for example, a part from the anterior surface of the cornea to the posterior surface of the crystalline lens. Rendering for constructing the display image is typically volume rendering or surface rendering.

The control unit 110 causes a display device (not shown) to display the display image constructed by the rendering unit 122. The user specifies a desired cross section for the displayed image using an operating device such as a pointing device. The position information of the cross section specified in the display image is input to the rendering unit 122.

Since the display image is a rendered image of the three-dimensional image, there is a trivial positional correspondence between the display image and the three-dimensional image. Based on this positional correspondence relationship, the rendering unit 122 specifies the position of the cross section in the three-dimensional image corresponding to the position of the cross section designated in the display image. That is, the rendering unit 122 specifies a cross section for the three-dimensional image.

Further, the rendering unit 122 can construct a three-dimensional partial image by cutting the three-dimensional image at the cross section. The rendering unit 122 can render this three-dimensional partial image to construct an image for display.

The analysis unit 123 applies the analysis process to the image of the eye E to be inspected. The image to which the analysis process is applied may be, for example, at least one image among a plurality of images collected by scanning the slit light, or an image obtained by processing the image. Examples of the latter include a three-dimensional image constructed by the three-dimensional image construction unit 121, a rendered image constructed by the rendering unit 122, and other processed images.

The analysis process includes, for example, measurement of a predetermined parameter. For measurement, for example, processing for obtaining measurement data regarding parameters indicating the morphology of tissues (thickness, diameter, area, volume, angle, shape, etc.) and data regarding parameters indicating relationships between tissues (distance, direction, etc.) are used. It may be any of the required processes. Examples of measurement parameters are anterior corneal curvature, anterior corneal radius of curvature, posterior corneal curvature, posterior corneal radius of curvature, corneal diameter, corneal film thickness, corneal topography, anterior atrioventricular depth, angle, anterior lens curvature, anterior lens radius of curvature, and lens. There are posterior curvature, lens posterior radius of curvature, lens thickness, etc. The measurement data may be distribution data of measurement parameters.

The analysis process may further include evaluation of the measurement data. The evaluation includes, for example, comparison with standard data (reference data). The standard data may be, for example, normal eye data (normal eye database) or diseased eye data related to a predetermined disease (sick eye database). Examples of evaluation include evaluation of corneal shape (radius of curvature, radius of curvature distribution, topography, etc.), evaluation of corneal film thickness (distribution), evaluation of anterior chamber depth, evaluation of corner angle (distribution), lens shape (radius of curvature, curvature). Evaluation of radius of curvature (distribution, topography, etc.), evaluation of lens thickness (distribution), evaluation of cataract (opacity), etc.

The slit lamp microscope 200 may include a communication unit that performs data communication with other devices. The communication unit transmits data to another device and receives data transmitted from the other device. The data communication method executed by the communication unit is arbitrary. For example, the communication unit includes one or more of various communication interfaces such as an Internet-compliant communication interface, a dedicated line-compliant communication interface, a LAN-compliant communication interface, and a short-range communication-compliant communication interface. Data communication may be wired communication or wireless communication. The data transmitted and / or received by the communication unit may be encrypted. In that case, for example, the control unit 110 and / or the data processing unit 120 decodes the data received by the communication unit 9 and / or the encryption processing unit that encrypts the data transmitted by the communication unit. Includes a chemical processing unit.

The slit lamp microscope 200 may include a display device and an operation device. Alternatively, the display device or operation device may be a peripheral device of the slit lamp microscope 200. The display device displays various information under the control of the control unit 110. The display device may include a flat panel display such as a liquid crystal display (LCD). The operation device includes a device for operating the slit lamp microscope 200 and a device for inputting information. Operating devices include, for example, buttons, switches, levers, dials, handles, knobs, mice, keyboards, trackballs, operating panels and the like. A device in which a display device and an operation device are integrated, such as a touch screen, may be used.

<Second aspect>
The slit lamp microscope according to the second aspect will be described. 6 and 7 show a configuration example of the slit lamp microscope 200A according to this embodiment.

As shown in FIG. 6, the slit lamp microscope 200A includes a photographing system 6, an illumination system 8, a moving mechanism 60, and a computer 100, similarly to the slit lamp microscope 200 according to the first aspect. The moving mechanism 60 according to this aspect functions as a first deflection mechanism 70.

The computer 100 includes a control unit 110 and a data processing unit 120. The control unit 110B and the data processing unit 120B shown in FIG. 7 are an example of the control unit 110 of this embodiment and an example of the data processing unit 120 of this embodiment, respectively. The control unit 110B includes a first deflection control unit 111. The data processing unit 120B includes an image quality evaluation unit 124, a measurement unit 125, and a first determination unit 126. The data processing unit 120 (120B) of this embodiment may further include any one of the three-dimensional image construction unit 121, the rendering unit 122, and the analysis unit 123.

The first deflection mechanism 70 changes the direction of the optical axis (photographing optical axis O1) of the photographing system 6. That is, the first deflection mechanism 70 changes the direction of the photographing system 6, in other words, rotates the photographing system 6. For example, the first deflection mechanism 70 rotates the photographing system 6 substantially around the intersection of the object surface SP and the photographing optical axis O1 in the state where the above-mentioned alignment is performed. Reference numeral SPA in FIG. 6 indicates a virtual rotation axis of the photographing system 6 substantially located at the intersection of the object surface SP and the photographing optical axis O1. The first deflection mechanism 70 operates under the control of the first deflection control unit 111. The first deflection mechanism 70 includes, for example, an actuator that generates a rotational driving force, or an actuator that generates a linear driving force, and a mechanism that converts the linear driving force into a rotational driving force.

The image quality evaluation unit 124 analyzes the image of the eye E to be inspected acquired by the photographing system 6 and evaluates the image quality. The image quality evaluation parameter is, for example, the intensity of the edge (magnitude of gradient, magnitude of differential value), but may be another parameter. The image quality evaluation unit 124 analyzes the image of the eye E to be inspected, calculates the value of the image quality evaluation parameter, and evaluates the image quality by comparing the calculated parameter value with a predetermined threshold value.

The first deflection control unit 111 can control the first deflection mechanism 70 based on the result of evaluation by the image quality evaluation unit 124. For example, when the image quality evaluation unit 124 determines that the parameter value is less than the threshold value, the first deflection control unit 111 can control the first deflection mechanism 70 in order to change the orientation of the photographing system 6. ..

The measurement unit 125 and the first determination unit 126 generate information for changing the orientation of the photographing system 6 from the current orientation to a suitable orientation (target orientation). Information generation by the measurement unit 125 and the first determination unit 126 and image quality evaluation by the image quality evaluation unit 124 may be combined, or only one of these may be performed.

The measuring unit 125 analyzes the image of the eye E to be inspected acquired by the photographing system 6 and measures the radius of curvature of the cornea. The image analyzed by the measuring unit 125 may be, for example, one or more cross-sectional images acquired by the slit light, or a three-dimensional image constructed based on the scan of the slit light. The measuring unit 125 may be configured as the analysis unit 123 of the first aspect or a part thereof.

For example, the measuring unit 125 analyzes the image of the eye E to be inspected acquired by the photographing system 6 and identifies an image region corresponding to the anterior surface of the cornea. This image region identification may include, for example, any of segmentation, edge detection, thresholding, filtering, labeling, and machine learning using a convolutional neural network.

The measuring unit 125 may perform measurement on parameters other than the radius of curvature of the cornea. This measurement parameter may be any parameter that can be used to change the orientation of the photographing system 6.

The first determination unit 126 determines the target orientation of the photographing system 6 (photographing optical axis O1) based on at least the result of measurement by the measuring unit 125. In this target orientation, a default object surface SP (for example, an object surface SP aligned with the optical axis Ex of the eyeball), a default main surface of the optical system 6a, and an image pickup surface (image plane) of the image sensor 43 are set. The orientation of the photographing system 6 (the orientation of the main surface and the orientation of the image plane) so as to satisfy the Scheimpflug condition.

The parameters that can be used in the calculation for determining the target orientation are, for example, the relative position between the illumination system 8 and the imaging system 6 (for example, the imaging angle), and the relative position of the illumination system 8 with respect to the eye E to be inspected (for example,). , The deflection angle of the illumination optical axis O2 with respect to the eyeball optical axis Ex), the relative position of the imaging system 6 with respect to the eye E to be inspected, the setting of the elements of the illumination system 6 (for example, the slit width, the slit length, etc.), the elements of the imaging system 6. Any parameters related to the slit lamp microscope 200A, such as the setting of (for example, focal length, aperture value, etc.), may be included. In addition to the radius of curvature of the cornea, the parameters that can be used in the calculation to determine the target orientation are the refractive index of the cornea, the refractive index of the aqueous chamber, the refractive index of the crystalline lens, the corneal thickness, the depth of the anterior chamber, and the anterior surface of the crystalline lens. It may include any eye-related parameters such as radius of curvature, lens thickness, and radius of curvature of the posterior surface of the lens. The values of the parameters relating to the eye may be standard values or may be measured values for the eye to be inspected E.

The operation for determining the target orientation may be performed, for example, based on a default calculation formula including any of these parameters and / or a graph or table for any of these parameters. Further, the calculation for determining the target orientation may include, for example, processing using ray tracing, machine learning, or the like.

The first deflection control unit 111 can control the first deflection mechanism 70 so as to change the direction of the photographing system 6 (photographing optical axis O1) in the target direction determined by the first determination unit 126.

When the information generation by the measurement unit 125 and the first determination unit 126 and the image quality evaluation by the image quality evaluation unit 124 are combined, for example, when the image quality evaluation unit 124 determines that the image quality is insufficient, the measurement unit 125 and the first 1 The target direction is determined by the determination unit 126, and the direction of the photographing system 6 (photographing optical axis O1) can be changed based on the target direction.

An operation example of the slit lamp microscope 200A according to this aspect will be described. An example of the operation of the slit lamp microscope 200A is shown in FIG. It is assumed that preparatory processing such as alignment has already been performed.

(S1: Photographing the anterior segment)
First, the slit lamp microscope 200A photographs the anterior segment of the eye E to be inspected. This anterior segment imaging is performed using slit light, and consists of, for example, one or more imaging.

(S2: Evaluate image quality)
The image quality evaluation unit 124 analyzes the image of the anterior segment acquired in step S1 and evaluates the image quality. For example, the image quality evaluation unit 124 calculates the edge strength of the image of the anterior segment of the eye and compares the calculated edge strength with the threshold value. When the edge strength is equal to or more than the threshold value, the image quality is sufficient, and when the edge strength is less than the threshold value, the image quality is insufficient.

(S3: Image quality OK?)
If it is determined in step S2 that the image quality is sufficient (S3: Yes), the process proceeds to step S7. On the other hand, if it is determined in step S2 that the image quality is not sufficient (S3: No), the process proceeds to step S4.

(S4: Calculate the radius of curvature of the cornea)
When it is determined that the image quality of the anterior segment image acquired in step S1 is not sufficient (S3: No), the measuring unit 125 analyzes the image of the eye E to be inspected and measures the radius of curvature of the cornea. The image of the eye E to be inspected may be an anterior segment image acquired in step S1 or may be another image.

An example of the process performed when calculating the radius of curvature of the cornea from an image other than the anterior segment image acquired in step S1 will be described. When it is determined that the image quality of the anterior segment image acquired in step S1 is not sufficient (S3: No), the slit lamp microscope 200A rephotographs the anterior segment of the eye E to be inspected. This anterior segment imaging targets at least the anterior surface of the cornea. The measuring unit 125 obtains the radius of curvature of the cornea by analyzing the image acquired by this anterior segment imaging.

(S5: Determine the target direction of the shooting optical axis)
The first determination unit 126 determines the target orientation of the photographing system 6 (photographing optical axis O1) based on at least the radius of curvature of the cornea calculated in step S4.

(S6: Change the orientation of the shooting system)
The first deflection control unit 111 controls the first deflection mechanism 70 so that the direction of the photographing system 6 (photographing optical axis O1) matches the target direction determined in step S5.

(S7: Scan the anterior segment with slit light)
Corresponding to the completion of the deflection of the imaging system 6 in step S6, the slit lamp microscope 200A applies a scan with slit light to the anterior segment of the eye E to be inspected. As a result, for example, a clear image group extending from the anterior surface of the cornea to the posterior surface of the crystalline lens can be obtained.

The data processing unit 120B (three-dimensional image construction unit 121) can construct a three-dimensional image based on this image group. As a result, for example, a three-dimensional image representing a three-dimensional region extending from the anterior surface of the cornea to the posterior surface of the crystalline lens in high definition can be obtained.

The data processing unit 120B (rendering unit 122) can construct an arbitrary rendered image from this three-dimensional image. This allows the user to observe a high quality image of the desired portion of the eye E to be inspected.

The data processing unit 120B (analysis unit 123) can apply a predetermined analysis process to at least one of the plurality of images acquired in step S7 or an image obtained by processing the same. This makes it possible to obtain arbitrary analysis data regarding the eye E to be inspected.

In this example, the completion of the deflection (S6) of the photographing system 6 triggers the scan (S7) by the slit light, but the trigger of the scan by the slit light is not limited to this. For example, scanning with slit light may be started in response to a user's instruction. Further, in response to the completion of the deflection (S6) of the imaging system 6, the process returns to step S1, and the imaging of the anterior segment, the evaluation of the image quality, the measurement of the radius of curvature of the cornea, the determination of the target orientation, and the orientation of the imaging system 6 The changes may be executed again.

<Third aspect>
The slit lamp microscope according to the third aspect will be described. 9 and 10 show a configuration example of the slit lamp microscope 200B according to this embodiment.

As shown in FIG. 9, the slit lamp microscope 200B includes an imaging system 6, an illumination system 8, a moving mechanism 60 that functions as a first deflection mechanism 70, and a moving mechanism 60 that functions as a first deflection mechanism 70, similarly to the slit lamp microscope 200A according to the second aspect. It is equipped with a computer 100.

The computer 100 includes a control unit 110, a data processing unit 120, and a data receiving unit 130. The control unit 110B and the data processing unit 120C shown in FIG. 10 are an example of the control unit 110 of this embodiment and an example of the data processing unit 120 of this embodiment, respectively. The control unit 110B includes a first deflection control unit 111 similar to the second aspect. The data processing unit 120C includes a second determination unit 127 in addition to the image quality evaluation unit 124 similar to the second aspect. The data processing unit 120 (120C) of this embodiment may further include any one of the three-dimensional image construction unit 121, the rendering unit 122, the analysis unit 123, the measurement unit 125, and the first determination unit 126. The matters described in the first aspect and / or the second aspect can be applied to these optional elements.

Similar to the second aspect, the first deflection control unit 111 can control the first deflection mechanism 70 based on the evaluation result by the image quality evaluation unit 124.

The data receiving unit 130 receives the measurement data of the radius of curvature of the cornea of the eye E to be inspected, which has been acquired in advance. The data receiving unit 130 according to one aspect may include, for example, at least a part of the communication unit described above. In this case, the data receiving unit 130 receives the measurement data of the radius of curvature of the cornea of the eye E to be inspected from a filing system such as an electronic medical record system. The data receiving unit 130 according to another aspect includes a device (drive device, data reader, data scanner, etc.) for acquiring data recorded on a recording medium. In this case, the data receiving unit 130 (drive device, etc.) has, for example, the radius of curvature of the corneal radius of the eye E recorded on a computer-readable non-temporary recording medium (magnetic disk, optical disk, magneto-optical disk, semiconductor memory, etc.). Read the measurement data. Alternatively, the data receiving unit 130 (data scanner or the like) reads the measurement data of the radius of curvature of the cornea of the eye E to be inspected printed on the paper sheet.

The second determination unit 127 determines the target orientation of the imaging system 6 (imaging optical axis O1) based on at least the measurement data of the radius of curvature of the cornea of the eye E to be inspected acquired by the data reception unit 130. The target orientation and the method for determining the target (calculation method, etc.) may be the same as that for the first determination unit 126 according to the second aspect.

When the information generation by the second determination unit 127 and the image quality evaluation by the image quality evaluation unit 124 are combined, for example, when the image quality evaluation unit 124 determines that the image quality is insufficient, the second determination unit 127 determines the target orientation. The orientation of the photographing system 6 can be changed based on the determination and the target orientation.

An operation example of the slit lamp microscope 200B according to this aspect will be described. An example of the operation of the slit lamp microscope 200B is shown in FIG. It is assumed that preparatory processing such as alignment has already been performed.

(S11: Photographing the anterior segment of the eye)
First, for example, in the same manner as in step S1 of the second aspect, the slit lamp microscope 200B photographs the anterior segment of the eye E to be inspected.

(S12: Evaluate image quality)
For example, in the same manner as in step S2 of the second aspect, the image quality evaluation unit 124 analyzes the image of the anterior segment acquired in step S11 and evaluates the image quality.

(S13: Image quality OK?)
When it is determined in step S12 that the image quality is sufficient (S13: Yes), the process proceeds to step S17. On the other hand, when it is determined in step S12 that the image quality is not sufficient (S13: No), the process proceeds to step S14.

(S14: Acquisition of measurement data of corneal radius of curvature)
When it is determined that the image quality of the anterior segment image acquired in step S11 is not sufficient (S13: No), the data receiving unit 130 accepts the measurement data of the corneal radius of curvature of the eye E to be inspected acquired in advance.

(S15: Determine the target direction of the shooting optical axis)
The second determination unit 127 determines the target orientation of the photographing system 6 (photographing optical axis O1) based on at least the measurement data of the radius of curvature of the cornea acquired in step S14. This calculation is performed, for example, in the same manner as in step S5 of the second aspect.

(S16: Change the orientation of the shooting system)
For example, in the same manner as in step S6 of the second aspect, the first deflection control unit 111 first deflects so that the direction of the photographing system 6 (photographing optical axis O1) matches the target direction determined in step S15. The mechanism 70 is controlled.

(S17: Scan the anterior segment with slit light)
Corresponding to the completion of the deflection of the imaging system 6 in step S16, the slit lamp microscope 200B scans the anterior segment of the eye E to be inspected with slit light in the same manner as in step S7 of the second aspect, for example. Apply. As a result, for example, a clear image group extending from the anterior surface of the cornea to the posterior surface of the crystalline lens can be obtained.

The data processing unit 120C (three-dimensional image construction unit 121) can construct a three-dimensional image based on this image group. As a result, for example, a three-dimensional image representing a three-dimensional region extending from the anterior surface of the cornea to the posterior surface of the crystalline lens in high definition can be obtained.

The data processing unit 120C (rendering unit 122) can construct an arbitrary rendered image from this three-dimensional image. This allows the user to observe a high quality image of the desired portion of the eye E to be inspected.

The data processing unit 120C (analysis unit 123) can apply a predetermined analysis process to at least one of the plurality of images acquired in step S17 or an image obtained by processing the same. This makes it possible to obtain arbitrary analysis data regarding the eye E to be inspected.

For example, when the image quality of the image of the eye E to be inspected acquired in step S17 is insufficient, the data processing unit 120C (measurement unit 125) may use at least one of the plurality of images acquired in step S17 or at least one of them. By analyzing the image obtained by processing the above, or by analyzing the image obtained by the new photographing performed after step S17 or the image obtained by processing the image E. The radius of curvature of the cornea can be measured. Based on at least the measurement data of the radius of curvature of the cornea acquired thereby, the data processing unit 120C (first determination unit 126) can determine a new target orientation of the photographing system 6 (photographing optical axis O1). Further, the first deflection control unit 111 can control the first deflection mechanism 70 so as to change the direction of the photographing system 6 (photographing optical axis O1) to this new target direction. This series of processes is effective, for example, when there is a substantial difference between the measurement data of the corneal radius of curvature acquired in the past and the current corneal radius of curvature.

In this example, the completion of the deflection (S16) of the photographing system 6 triggers the scan (S17) by the slit light, but the trigger of the scan by the slit light is not limited to this. For example, scanning with slit light may be started in response to a user's instruction. Further, the process may return to step S11 in response to the completion of the deflection (S16) of the photographing system 6. At this time, the front eye portion may be photographed, the image quality may be evaluated, the orientation of the photographing system 6 may be changed, and the like may be executed again. Alternatively, as in the second aspect, imaging of the anterior segment of the eye, evaluation of image quality, measurement of the radius of curvature of the cornea, determination of the target orientation, change of the orientation of the imaging system 6, and the like may be performed.

<Fourth aspect>
The slit lamp microscope according to the fourth aspect will be described. 12 and 13 show a configuration example of the slit lamp microscope 200C according to this embodiment.

As shown in FIG. 12, the slit lamp microscope 200C includes a photographing system 6, an illumination system 8, and a computer 100, similarly to the slit lamp microscope 200 according to the first aspect. Further, the slit lamp microscope 200C further includes a moving mechanism 60A including a second deflection mechanism 61.

The computer 100 includes a control unit 110 and a data processing unit 120. The control unit 110C and the data processing unit 120D shown in FIG. 13 are an example of the control unit 110 of this embodiment and an example of the data processing unit 120 of this embodiment, respectively. The control unit 110C includes a second deflection control unit 112. The data processing unit 120D includes an image quality evaluation unit 124, a measurement unit 125, and a third determination unit 128. The data processing unit 120 (120D) of this embodiment may further include any one of the three-dimensional image construction unit 121, the rendering unit 122, the analysis unit 123, the first determination unit 126, and the second determination unit 127. Further, the slit lamp microscope 200C may include a first deflection mechanism 70, and may further include a first deflection control unit 111.

The second deflection mechanism 61 changes the direction of the optical axis (illumination optical axis O2) of the illumination system 8. That is, the second deflection mechanism 61 changes the direction of the illumination system 8, in other words, rotates the illumination system 8. For example, the second deflection mechanism 61 rotates the illumination optical axis O2 around the intersection of the cornea of the eye E to be inspected and the illumination optical axis O2 in the above-mentioned alignment state (see FIG. 12). The second deflection mechanism 61 operates under the control of the second deflection control unit 112. The second deflection mechanism 61 includes, for example, an actuator that generates a rotational driving force, an actuator that generates a linear driving force, and a mechanism that converts the linear driving force into a rotational driving force.

In this aspect, the second deflection mechanism 61 is included in the moving mechanism 60A. The moving mechanism 60A is an element similar to the moving mechanism 60 of the first aspect, and includes at least a mechanism for rotating the illumination optical axis O2 (second deflection mechanism 61).

Similar to the second aspect, the image quality evaluation unit 124 analyzes the image of the eye E to be inspected acquired by the photographing system 6 and evaluates the image quality. The second deflection control unit 112 can control the second deflection mechanism 61 based on the result of evaluation by the image quality evaluation unit 124. For example, when the image quality evaluation unit 124 determines that the parameter value is less than the threshold value, the second deflection control unit 112 may control the second deflection mechanism 61 in order to change the direction of the illumination optical axis O2. it can.

The measurement unit 125 and the third determination unit 128 generate information for changing the direction of the illumination optical axis O2 from the current direction to a suitable direction (target direction). The information generation by the measuring unit 125 and the third determination unit 128 and the image quality evaluation by the image quality evaluation unit 124 may be combined, or only one of these may be performed.

Similar to the second aspect, the measuring unit 125 analyzes the image of the eye E to be inspected acquired by the photographing system 6 and measures the radius of curvature of the cornea. The measuring unit 125 may perform measurement on parameters other than the radius of curvature of the cornea. This measurement parameter may be any parameter that can be used to change the direction of the illumination optical axis O2.

The third determination unit 128 determines the target direction of the illumination optical axis O2 based on at least the result of the measurement by the measurement unit 125. The target orientation is the illumination optical axis O2 such that the object surface SP, the default main surface of the optical system 6a, and the image pickup surface (default image plane) of the image pickup element 43 satisfy the Scheimpflug condition. The orientation (the orientation of the object surface SP).

The parameters that can be used in the calculation for determining the target orientation are, for example, the relative position between the illumination system 8 and the imaging system 6 (for example, the imaging angle), and the relative position of the illumination system 8 with respect to the eye E to be inspected (for example,). , The deflection angle of the illumination optical axis O2 with respect to the eyeball optical axis Ex), the relative position of the imaging system 6 with respect to the eye E to be inspected, the setting of the elements of the illumination system 6 (for example, the slit width, the slit length, etc.), the elements of the imaging system 6. Any parameters related to the slit lamp microscope 200C, such as the setting of (for example, focal length, aperture value, etc.), may be included. In addition to the radius of curvature of the cornea, the parameters that can be used in the calculation to determine the target orientation are the refractive index of the cornea, the refractive index of the aqueous chamber, the refractive index of the crystalline lens, the corneal thickness, the depth of the anterior chamber, and the anterior surface of the crystalline lens. It may include any eye-related parameters such as radius of curvature, lens thickness, and radius of curvature of the posterior surface of the lens. The values of the parameters relating to the eye may be standard values or may be measured values for the eye to be inspected E.

The operation for determining the target orientation may be performed, for example, based on a default calculation formula including any of these parameters and / or a graph or table for any of these parameters. Further, the calculation for determining the target orientation may include, for example, processing using ray tracing, machine learning, or the like.

The second deflection control unit 112 can control the second deflection mechanism 61 so as to change the direction of the illumination optical axis O2 in the target direction determined by the third determination unit 128 (illumination shown in FIG. 12). Rotation of the angle Δθ of the optical axis O2). As a result, it is possible to realize a physical surface SP that satisfies the Scheimpflug condition in the relationship between the main surface of the optical system 6a and the image pickup surface (image plane) of the image pickup element 43.

When the information generation by the measurement unit 125 and the third determination unit 128 and the image quality evaluation by the image quality evaluation unit 124 are combined, for example, when the image quality evaluation unit 124 determines that the image quality is insufficient, the measurement unit 125 and the first 3 The target direction can be determined by the determination unit 128, and the direction of the illumination optical axis O2 can be changed based on the target direction.

An operation example of the slit lamp microscope 200C according to this aspect will be described. An example of the operation of the slit lamp microscope 200C is shown in FIG. It is assumed that preparatory processing such as alignment has already been performed.

(S21: Photographing the anterior segment of the eye)
First, for example, in the same manner as in step S1 of the second aspect, the slit lamp microscope 200C photographs the anterior segment of the eye E to be inspected.

(S22: Evaluate image quality)
The image quality evaluation unit 124 analyzes the image of the anterior segment acquired in step S21 and evaluates the image quality in the same manner as in step S2 of the second aspect, for example.

(S23: Image quality OK?)
When it is determined in step S22 that the image quality is sufficient (S23: Yes), the process proceeds to step S27. On the other hand, when it is determined in step S22 that the image quality is not sufficient (S23: No), the process proceeds to step S24.

(S24: Calculate the radius of curvature of the cornea)
When it is determined that the image quality of the anterior segment image acquired in step S21 is not sufficient (S23: No), the measuring unit 125 displays the image of the eye E to be inspected in the same manner as in step S4 of the second aspect, for example. Analyze and measure the radius of curvature of the cornea.

(S25: Determine the target direction of the illumination optical axis)
The third determination unit 128 determines the target orientation of the illumination optical axis O2 based on at least the radius of curvature of the cornea calculated in step S24.

(S26: Change the direction of the lighting system)
The second deflection control unit 112 changes the direction of the illumination system 8 under the control of the second deflection mechanism 61 so that the direction of the illumination optical axis O2 matches the target direction determined in step S25.

(S27: Scan the anterior segment with slit light)
Corresponding to the completion of the deflection of the illumination system 8 in step S26, the slit lamp microscope 200C applies a scan by slit light to the anterior segment of the eye E to be inspected. As a result, for example, a clear image group extending from the anterior surface of the cornea to the posterior surface of the crystalline lens can be obtained.

The data processing unit 120D (three-dimensional image construction unit 121) can construct a three-dimensional image based on this image group. As a result, for example, a three-dimensional image representing a three-dimensional region extending from the anterior surface of the cornea to the posterior surface of the crystalline lens in high definition can be obtained.

The data processing unit 120D (rendering unit 122) can construct an arbitrary rendered image from this three-dimensional image. This allows the user to observe a high quality image of the desired portion of the eye E to be inspected.

The data processing unit 120D (analysis unit 123) can apply a predetermined analysis process to at least one of the plurality of images acquired in step S27 or an image obtained by processing the same. This makes it possible to obtain arbitrary analysis data regarding the eye E to be inspected.

In this example, the completion of the deflection (S26) of the illumination system 8 triggers the scan (S27) by the slit light, but the trigger of the scan by the slit light is not limited to this. For example, scanning with slit light may be started in response to a user's instruction. Further, in response to the completion of the deflection (S26) of the illumination system 8, the process returns to step S21 to photograph the anterior segment, evaluate the image quality, measure the radius of curvature of the cornea, determine the target orientation, and determine the orientation of the illumination system 8. The changes may be executed again.

<Fifth aspect>
The slit lamp microscope according to the fifth aspect will be described. 15 and 16 show a configuration example of the slit lamp microscope 200D according to this embodiment.

As shown in FIG. 15, the slit lamp microscope 200D includes a photographing system 6, an illumination system 8, a moving mechanism 60A including a second deflection mechanism 61, and a computer, similarly to the slit lamp microscope 200C according to the fourth aspect. With 100.

The computer 100 includes a control unit 110, a data processing unit 120, and a data receiving unit 130. The control unit 110C and the data processing unit 120E shown in FIG. 16 are an example of the control unit 110 of this embodiment and an example of the data processing unit 120 of this embodiment, respectively. The control unit 110C includes a second deflection control unit 112 similar to the fourth aspect. The data processing unit 120E includes a fourth determination unit 129 in addition to the image quality evaluation unit 124 similar to the second aspect. The data processing unit 120 (120E) of this embodiment is a three-dimensional image construction unit 121, a rendering unit 122, an analysis unit 123, a measurement unit 125, a first determination unit 126, a second determination unit 127, and a third determination unit 128. Any of them may be further included. Further, the slit lamp microscope 200D may include a first deflection mechanism 70, and may further include a first deflection control unit 111. The data receiving unit 130 receives the measurement data of the radius of curvature of the cornea of the eye E to be inspected, which has been acquired in advance, as in the third aspect.

The fourth determination unit 129 determines the target orientation of the illumination optical axis O2 based on at least the measurement data of the radius of curvature of the cornea of the eye E to be inspected acquired by the data reception unit 130. The target orientation and the method for determining the target (calculation method, etc.) may be the same as that for the third determination unit 128 according to the fourth aspect.

When the information generation by the 4th determination unit 129 and the image quality evaluation by the image quality evaluation unit 124 are combined, for example, when the image quality evaluation unit 124 determines that the image quality is insufficient, the 4th determination unit 129 determines the target orientation. It can be determined and the orientation of the lighting system 8 can be changed based on this target orientation.

An operation example of the slit lamp microscope 200D according to this aspect will be described. An example of the operation of the slit lamp microscope 200D is shown in FIG. It is assumed that preparatory processing such as alignment has already been performed.

(S31: Photographing the anterior segment of the eye)
First, for example, in the same manner as in step S1 of the second aspect, the slit lamp microscope 200D photographs the anterior segment of the eye E to be inspected.

(S32: Evaluate image quality)
For example, in the same manner as in step S2 of the second aspect, the image quality evaluation unit 124 analyzes the image of the anterior segment acquired in step S31 and evaluates the image quality.

(S33: Image quality OK?)
When it is determined in step S32 that the image quality is sufficient (S33: Yes), the process proceeds to step S37. On the other hand, when it is determined in step S32 that the image quality is not sufficient (S33: No), the process proceeds to step S34.

(S34: Acquisition of measurement data of corneal radius of curvature)
When it is determined that the image quality of the anterior segment image acquired in step S31 is not sufficient (S33: No), the data receiving unit 130 accepts the measurement data of the corneal radius of curvature of the eye E to be inspected acquired in advance.

(S35: Determine the target direction of the illumination optical axis)
The fourth determination unit 129 determines the target orientation of the illumination optical axis O2 based on at least the measurement data of the radius of curvature of the cornea acquired in step S34. This calculation is executed in the same manner as in step S25 of the fourth aspect, for example.

(S36: Change the direction of the lighting system)
For example, in the same manner as in step S26 of the fourth aspect, the second deflection control unit 112 controls the second deflection mechanism 61 so that the direction of the illumination optical axis O2 matches the target direction determined in step S35. The direction of the lighting system 8 is changed.

(S37: Scan the anterior segment with slit light)
Corresponding to the completion of the deflection of the illumination system 8 in step S36, the slit lamp microscope 200D scans the anterior segment of the eye E to be inspected with slit light in the same manner as in step S7 of the second aspect, for example. Apply. As a result, for example, a clear image group extending from the anterior surface of the cornea to the posterior surface of the crystalline lens can be obtained.

The data processing unit 120E (three-dimensional image construction unit 121) can construct a three-dimensional image based on this image group. As a result, for example, a three-dimensional image representing a three-dimensional region extending from the anterior surface of the cornea to the posterior surface of the crystalline lens in high definition can be obtained.

The data processing unit 120E (rendering unit 122) can construct an arbitrary rendered image from this three-dimensional image. This allows the user to observe a high quality image of the desired portion of the eye E to be inspected.

The data processing unit 120E (analysis unit 123) can apply a predetermined analysis process to at least one of the plurality of images acquired in step S37 or an image obtained by processing the same. This makes it possible to obtain arbitrary analysis data regarding the eye E to be inspected.

For example, when the image quality of the image of the eye E to be inspected acquired in step S37 is insufficient, the data processing unit 120E (measurement unit 125) may use at least one of the plurality of images acquired in step S37 or a plurality of images thereof. By analyzing the image obtained by processing the above, or by analyzing the image obtained by the new photographing performed after step S37 or the image obtained by processing the image E. The radius of curvature of the cornea can be measured. Based on at least the measurement data of the radius of curvature of the cornea acquired thereby, the data processing unit 120E (third determination unit 128) can determine a new target orientation of the illumination optical axis O2. Further, the second deflection control unit 112 can deflect the illumination system 8 by controlling the second deflection mechanism 61 so as to change the direction of the illumination optical axis O2 to this new target direction. This series of processes is effective, for example, when there is a substantial difference between the measurement data of the corneal radius of curvature acquired in the past and the current corneal radius of curvature.

In this example, the completion of the deflection (S36) of the illumination system 8 triggers the scan (S37) by the slit light, but the trigger of the scan by the slit light is not limited to this. For example, scanning with slit light may be started in response to a user's instruction. Further, the process may return to step S31 in response to the completion of the deflection (S36) of the lighting system 8. At this time, the image of the anterior segment of the eye, the evaluation of the image quality, the change of the direction of the lighting system 8, and the like may be executed again. Alternatively, as in the fourth aspect, imaging of the anterior segment of the eye, evaluation of image quality, measurement of the radius of curvature of the cornea, determination of the target orientation, change of the orientation of the illumination system 8, and the like may be performed.

<Effect>
The effect of the slit lamp microscope according to the embodiment will be described.

The slit lamp microscope according to some aspects includes an illumination system and an imaging system. The lighting system projects slit light onto the anterior segment of the eye to be inspected. The photographing system includes an optical system that guides the light from the anterior segment to which the slit light is projected, and an image pickup element that receives the light guided by the optical system on the image pickup surface. Further, the object surface including the focal point of the illumination system displaced by the refractive index of the tissue of the anterior segment of the eye, the main surface of the optical system, and the imaging surface are arranged so as to satisfy the Scheimpflug condition.

For example, the slit lamp microscope 200 includes an illumination system 8 and a photographing system 6. The illumination system 8 projects slit light onto the anterior segment of the eye E to be inspected. The photographing system 6 includes an optical system 6a that guides the light from the anterior segment to which the slit light is projected, and an image pickup element 43 that receives the light guided by the optical system 6a on the imaging surface. Further, the object surface SP including the focal point of the illumination system 8 displaced by the refractive index of the tissue of the anterior segment of the eye, the main surface of the optical system 6a, and the image pickup surface of the image pickup element 43 so as to satisfy the Scheimpflug condition. Is located in.

According to such a slit lamp microscope, the object surface, the main surface of the optical system, and the imaging surface satisfy the Scheimpflug condition in consideration of the displacement of the focal point of the illumination system due to the refractive index of the tissue of the anterior segment of the eye. Therefore, it is possible to acquire a focused image of the area of the eye to be inspected corresponding to the object surface.

In some embodiments, the deflection angle of the object surface due to the refractive index of the tissue of the anterior segment of the eye may be included in the range of 3 to 13 degrees, and may be further included in the range of 6 to 10 degrees. Good. Further, in some embodiments, the deflection angle of the object surface due to the refractive index of the tissue of the anterior segment of the eye may be determined at least based on the value of the radius of curvature of the cornea and the value of the refractive index of the eye in a predetermined model eye.

In some embodiments, the slit lamp microscope may further include a moving mechanism that moves the illumination and imaging systems. Further, the photographing system may be configured to acquire a plurality of images of the anterior segment of the eye by repeatedly performing imaging in parallel with the movement of the lighting system and the photographing system by the moving mechanism.

For example, the slit lamp microscope 200 includes a moving mechanism 60 that moves the illumination system 8 and the photographing system 6. The photographing system 6 can acquire a plurality of images of the anterior segment of the eye by repeatedly performing imaging in parallel with the movement of the lighting system 8 and the photographing system 6 by the moving mechanism 60. The mode in which the movement of the lighting system 8 and the photographing system 6 and the repeated photographing are executed in parallel is arbitrary. In one example, repeated imaging can be performed in parallel with the continuous movement of the lighting system 8 and the imaging system 6. In another example, the lighting system 8 and the photographing system 6 can be moved and photographed alternately.

With such a slit lamp microscope, it is possible to repeatedly take images in parallel with the movement of the object surface, so that it is possible to acquire an in-focus image of the area of the eye to be inspected corresponding to the movement range of the object surface. It is possible.

In some embodiments, the slit lamp microscope further provides a three-dimensional image construction unit that constructs a three-dimensional image based on a plurality of images of the anterior segment acquired by repeated imaging in parallel with the movement of the illumination system and the imaging system. May include.

For example, the slit lamp microscope 200 constructs a three-dimensional image based on a plurality of images of the anterior segment acquired by repeated imaging in parallel with the movement of the illumination system 8 and the photographing system 6 by the three-dimensional image constructing unit 121. Can be done.

According to such a slit lamp microscope, it is possible to acquire a three-dimensional image in focus for a three-dimensional region of the eye to be inspected, which corresponds to a moving range of an object surface.

In some embodiments, the slit lamp microscope may further include a rendering unit that renders the 3D image constructed by the 3D image building unit to build the rendered image.

For example, the slit lamp microscope 200 can construct a rendered image by rendering the three-dimensional image constructed by the three-dimensional image constructing unit 121 by the rendering unit 122.

According to such a slit lamp microscope, it is possible to construct and observe a desired rendered image from a three-dimensional image in focus for a three-dimensional region of the eye to be inspected.

In some embodiments, the slit lamp microscope is an image (3) obtained by processing at least one or a plurality of images of the anterior segment of the eye acquired by repeated imaging in parallel with the movement of the illumination system and the imaging system. It may include an analysis unit that applies a predetermined analysis process to a three-dimensional image, a rendered image, another processed image, etc.).

For example, the slit lamp microscope 200 is an image obtained by processing at least one of a plurality of images of the anterior segment of the eye acquired by the analysis unit 123 by repeated imaging in parallel with the movement of the illumination system and the imaging system. A predetermined analysis process can be applied to the image.

According to such a slit lamp microscope, it is possible to analyze a high-quality image in which an object surface is in focus, so that it is possible to acquire highly accurate and highly accurate analysis data.

In some embodiments, the slit lamp microscope may further include a first deflection mechanism that changes the orientation of the optical axis of the imaging system.

For example, the slit lamp microscope 200A (or 200B) includes a first deflection mechanism 70 that changes the direction of the optical axis (photographing optical axis) O1 of the photographing system 6.

According to such a slit lamp microscope, an image is taken so that the object surface, the main surface of the optical system, and the image pickup surface of the image sensor satisfy the Scheimpflug condition according to individual differences in the tissue shape and characteristics of the eye to be inspected. It is possible to adjust the direction of the optical axis of the system 6.

In some embodiments, the first deflection mechanism may be configured to rotate the imaging system substantially around the intersection of the object surface and the optical axis of the imaging system.

For example, the first deflection mechanism 70 of the slit lamp microscope 200A (or 200B) is a virtual rotation axis SPA located substantially at the intersection of the object surface SP and the optical axis (photographing optical axis) O1 of the photographing system 6. The photographing system 6 is configured to rotate around the center.

According to such a slit lamp microscope, it is possible to adjust the orientation of the imaging system in order to satisfy the Scheimpflug condition without changing the position of the illumination system with respect to the cornea of the eye to be inspected.

In some embodiments, the slit lamp microscope has an image quality evaluation unit that analyzes the image of the eye to be inspected acquired by the imaging system to evaluate the image quality, and a first deflection mechanism based on at least the evaluation result by the image quality evaluation unit. It may further include a first deflection control unit that performs control.

For example, the slit lamp microscope 200A (or 200B) analyzes the image of the eye E to be inspected acquired by the photographing system 6 to evaluate the image quality, and the image quality evaluation unit 124 evaluates the image quality at least based on the evaluation result. It further includes a first deflection control unit 111 that controls the first deflection mechanism 70.

According to such a slit lamp microscope, it is possible to adjust the orientation of the photographing system in order to satisfy the Scheimpflug condition according to the image quality of the actually acquired image. For example, poor quality images can be obtained if the Scheimpflug conditions are not met. In such a case, according to this aspect, it is possible to automatically adjust the orientation of the photographing system.

In some embodiments, the slit lamp microscope has a measuring unit that analyzes the image of the eye to be inspected acquired by the imaging system to measure the radius of curvature of the cornea, and an optical axis of the imaging system based on at least the measurement results of the measuring unit. It may further include a first determination part that determines the target orientation of the. Further, the slit lamp microscope of the present embodiment may be configured to change the orientation of the photographing system to this target orientation by the first deflection mechanism.

For example, the slit lamp microscope 200A has a measuring unit 125 that analyzes the image of the eye E to be inspected acquired by the photographing system 6 to measure the radius of curvature of the cornea, and the photographing system 6 based on at least the result of the measurement by the measuring unit 125. It further includes a first determination unit 126 that determines the target orientation of the optical axis (photographing optical axis) O1. In the slit lamp microscope 200A, the orientation of the photographing system 6 can be changed to the target orientation determined by the first determination unit 126 by the first deflection mechanism 70.

According to such a slit lamp microscope, the radius of curvature of the cornea of the eye to be inspected is actually measured, the target direction of the optical axis of the imaging system is determined from the obtained data, and the imaging system for satisfying the Scheimpflug condition. The orientation of the can be adjusted. This makes it possible to adjust the orientation of the photographing system with high accuracy and high accuracy.

In some embodiments, the slit lamp microscope determines the target orientation of the optical axis of the imaging system based on at least the data receiving unit that receives the measurement data of the corneal radius of curvature of the eye to be inspected and the measurement data. 2 A determination unit may be further provided. Further, the slit lamp microscope of this embodiment may be configured to change the direction of the optical axis of the photographing system to this target direction by the first deflection mechanism.

For example, the slit lamp microscope 200B has a data receiving unit 130 that receives measurement data of the radius of curvature of the cornea of the eye E to be inspected in advance, and an optical axis (photographing optical axis) O1 of the photographing system 6 based on at least this measurement data. It further includes a second determination unit 127 that determines the target orientation. The slit lamp microscope 200B can change the direction of the optical axis (photographing optical axis) O1 of the photographing system 6 to the target direction determined by the second determination unit 127 by the first deflection mechanism 70.

According to such a slit lamp microscope, the target orientation of the optical axis of the imaging system is determined from the actual measurement data of the radius of curvature of the cornea of the eye to be inspected, and the orientation of the imaging system is adjusted to satisfy the Scheimpflug condition. It can be carried out. This makes it possible to adjust the orientation of the photographing system with high accuracy and high accuracy.

In some embodiments, the imaging system may be configured to initiate imaging of the anterior segment in response to a change in the orientation of the optical axis of the imaging system by the first deflection mechanism.

For example, in the slit lamp microscope 200A (or 200B), the front eye by the illumination system 8 and the imaging system 6 corresponds to the change in the direction of the optical axis (optical axis) O1 of the imaging system 6 by the first deflection mechanism 70. You can start shooting the part.

According to such a slit lamp microscope, it is possible to automatically perform anterior segment imaging after the orientation of the imaging system is adjusted, so that anterior segment imaging is performed in a state where the Scheimpflug conditions are not satisfied. It is possible to avoid such a situation.

In some embodiments, the slit lamp microscope may further include a second deflection mechanism that redirects the optical axis of the illumination system.

For example, the slit lamp microscope 200C (or 200D) further includes a second deflection mechanism 61 that changes the direction of the optical axis (illumination optical axis) O2 of the illumination system 8.

According to such a slit lamp microscope, the object surface, the main surface of the optical system, and the image pickup surface of the image sensor are illuminated so as to satisfy the Scheimpflug condition according to individual differences in the tissue shape and characteristics of the eye to be inspected. It is possible to adjust the orientation of the system.

In some embodiments, the second deflection mechanism may be configured to rotate the illumination optical axis around the intersection of the cornea of the eye to be inspected and the illumination optical axis.

For example, the second deflection mechanism 61 of the slit lamp microscope 200C (or 200D) is configured to rotate the illumination optical axis O2 (illumination system 8) around the intersection of the cornea of the eye E to be inspected and the illumination optical axis O2. Has been done.

According to such a slit lamp microscope, it is possible to adjust the orientation of the illumination system in order to satisfy the Scheimpflug condition without changing the position of the imaging system with respect to the cornea of the eye to be inspected.

In some embodiments, the slit lamp microscope has an image quality evaluation unit that analyzes the image of the eye to be inspected acquired by the imaging system to evaluate the image quality, and a second deflection mechanism based on at least the evaluation result by the image quality evaluation unit. A second deflection control unit that performs control may be further included.

For example, the slit lamp microscope 200C (or 200D) analyzes the image of the eye E to be inspected acquired by the photographing system 6 to evaluate the image quality, and the image quality evaluation unit 124 evaluates the image quality at least based on the evaluation result. It further includes a second deflection control unit 112 that controls the second deflection mechanism 61.

According to such a slit lamp microscope, the orientation of the illumination system can be adjusted to satisfy the Scheimpflug condition according to the image quality of the actually acquired image. For example, poor quality images can be obtained if the Scheimpflug conditions are not met. In such a case, according to this aspect, it is possible to automatically adjust the orientation of the lighting system.

In some embodiments, the slit lamp microscope has a measuring unit that analyzes the image of the eye to be inspected acquired by the imaging system to measure the radius of curvature of the cornea, and an optical axis of the illumination system based on at least the measurement results of the measuring unit. It may further include a third determination part that determines the target orientation of the. Further, the slit lamp microscope of this embodiment may be configured to change the direction of the illumination optical axis to this target direction by the second deflection mechanism.

For example, the slit lamp microscope 200C has a measuring unit 125 that analyzes the image of the eye E to be inspected acquired by the photographing system 6 to measure the radius of curvature of the cornea, and an illumination optical axis O2 based on at least the measurement result by the measuring unit 125. It is further provided with a third determination unit 128 that determines the target orientation of the above. The slit lamp microscope 200C can change the direction of the illumination optical axis O2 to this target direction by the second deflection mechanism 61.

According to such a slit lamp microscope, the radius of curvature of the cornea of the eye to be inspected is actually measured, the target orientation of the illumination optical axis is determined from the obtained data, and the orientation of the illumination system for satisfying the shineproof condition. Can be adjusted. This makes it possible to adjust the orientation of the lighting system with high accuracy and high accuracy.

In some embodiments, the slit lamp microscope has a data receiving unit that receives measurement data of the corneal radius of curvature of the eye to be inspected, and a fourth determination that determines the target orientation of the illumination optical axis based on at least this measurement data. It may be further provided with a part. Further, the slit lamp microscope of this embodiment may be configured to change the direction of the illumination optical axis to the target direction by the second deflection mechanism.

For example, the slit lamp microscope 200D has a data receiving unit 130 that receives measurement data of the radius of curvature of the cornea of the eye E to be inspected in advance, and a fourth determination that determines the target direction of the illumination optical axis O2 based on at least this measurement data. It further includes a portion 129. Further, in the slit lamp microscope 200D, the direction of the illumination optical axis O2 can be changed to the target direction by the second deflection mechanism 61.

According to such a slit lamp microscope, the target orientation of the illumination optical axis is determined from the actual measurement data of the radius of curvature of the cornea of the eye to be inspected, and the orientation of the illumination system is adjusted to satisfy the shineproof condition. Can be done. This makes it possible to adjust the lighting system with high accuracy and high accuracy.

In some embodiments, the imaging system may be configured to initiate imaging of the anterior segment in response to a change in the orientation of the illumination system by the second deflection mechanism.

For example, the slit lamp microscope 200C (or 200D) can start imaging of the anterior segment of the eye by the illumination system and the imaging system in response to the change in the orientation of the illumination system by the second deflection mechanism.

According to such a slit lamp microscope, it is possible to automatically perform anterior segment imaging after the orientation of the illumination system is adjusted, so that anterior segment imaging is performed in a state where the Scheimpflug conditions are not satisfied. It is possible to avoid such a situation.

<Sixth aspect>
In the first to fifth aspects described above, it is assumed that the directions (incident angles) of all the main rays incident on the image pickup surface of the image pickup device are the same. However, in consideration of the fact that the imaging surface is eccentric and inclined with respect to the optical axis of the optical system, strictly speaking, the incident angles of the main rays reaching different positions on the imaging surface are different. The present aspect provides some exemplary optical system configurations that take into account such differences in incident angles.

First, the optical simulation carried out by the present inventor will be described. As shown in FIG. 18, as an example, three positions 300a, 300b, and 300c of the image pickup device 300 on the image pickup surface are considered. Reference numeral 301 indicates an optical system optical axis passing through the center of the diaphragm (or a main ray traveling along the optical system optical axis). The angle of view of the image obtained by the image sensor 300 is defined with reference to the optical axis 301 of the optical system. The position 300b corresponds to the center of the angle of view. The main ray incident angle at position 300b was set to 38.11 degrees. At this time, the main ray incident angle at the position 300a (lower end position of the angle of view) was 40.09 degrees, and the main ray incident angle at the position 300c (upper end position of the angle of view) was 36.06 degrees. As described above, it was found that the error of the incident angle of the main ray within the angle of view reaches a maximum of about 4 degrees.

In the first to fifth aspects, the main ray incident angle of 38.11 degrees at the position 300b corresponding to the center of the angle of view is typically applied to the entire angle of view. On the other hand, in this embodiment, different main ray incident angles are applied to different positions within the angle of view. That is, although it is assumed that the main ray incident angle is uniform in the first to fifth aspects, the non-uniformity of the main ray incident angle is considered in this embodiment.

The result of such a simulation is shown. The positions on the imaging surface corresponding to the apex of the cornea, the anterior lens capsule, the lens nucleus, and the posterior lens capsule are referred to as the corneal corresponding position, the anterior capsule corresponding position, the nuclear corresponding position, and the posterior capsule corresponding position.

The distance between the corneal compatible position and the anterior capsule compatible position is set to 2.55 mm, the distance between the corneal compatible position and the nuclear compatible position is set to 4.91 mm, and the corneal compatible position and the posterior capsule compatible position The distance between them is set to 7.14 mm.

Further, the design value of the main ray incident angle at the corneal corresponding position was set to 39.11 degrees, and 39.11 degrees was obtained as the correction value. The design value of the main ray incident angle at the position corresponding to the anterior capsule was set to 38.61 degrees, and 34.63 degrees was obtained as the correction value. The design value of the main ray incident angle at the nuclear correspondence position was set to 38.11 degrees, and 31.64 degrees was obtained as the correction value. The design value of the main ray incident angle at the position corresponding to the posterior capsule was set to 37.61 degrees, and 29.24 degrees was obtained as the correction value.

The average of these correction values is 33.65 degrees. In this aspect, the optical system can be designed so that the angle of incidence of the main ray on the imaging surface has an average value of 33.65 degrees.

An example of the calculation for obtaining the correction value of the main ray incident angle will be described below. Reference numeral 400 in FIG. 19 indicates an eyeball (eyeball model). The eyeball 400 is arranged so that the corneal apex 401 is located at the origin of the xy coordinate system and the optical axis of the eyeball coincides with the y-axis. Reference numeral 410 indicates an image pickup surface (air conversion image plane) of the air-converted image pickup device. The air-equivalent image plane 410 passes through the corneal apex 401. Reference numeral 420 indicates a main ray. The imaging position of the ray including the main ray 420 is indicated by reference numeral 421. Further, assuming that the angle formed by the main ray 420 with respect to the y-axis is θ ₁ and each formed by the air-converted image plane 410 with respect to the y-axis is θ ₂ , the angle of incidence of the main ray 420 with respect to the air-converted image plane 410 is θ. Is expressed as θ = θ ₁ + θ ₂ .

In the model shown in FIG. 19, the correction value of the main ray incident angle can be obtained by obtaining the condition for the optical axis of the image plane converted in the eyeball and the optical axis of the eyeball (typically the illumination optical axis) to match. .. As can be seen from FIG. 19, that the optical axis of the image plane converted in the eyeball and the optical axis of the eyeball coincide with each other means that the image formation position 421 of the light ray including the main ray 420 is arranged on the y-axis, that is, y. It is synonymous with setting the displacement Δ of the image formation position 421 with respect to the axis in the x direction to zero (making the displacement Δ close to zero: Δ → 0).

With respect to an arbitrary principal ray incident angle (arbitrary position on the imaging surface) θ (θ = θ ₁ + θ ₂ ), the displacement Δ can be obtained, for example, through the following four calculation steps.

(1) Set θ ₁ and θ ₂ . If _one of θ ₁ and θ ₂ is set, the other is uniquely determined. For example, since θ is given, if θ ₁ is set, then θ ₂ = θ − θ ₁ .

(2) The intersection of the main ray 420 and the air-equivalent image plane 410 is obtained without considering the refraction by the eyeball 400. That is, the design position of the imaging position 421 is obtained.

(3) The position where the main ray 420 is incident on the eyeball 400 (cornea) is determined. In other words, the intersection of the surface of the eyeball 400 and the main ray 420 is obtained. Further, the incident angle and the exit angle of the main ray 420 at this intersection are obtained. That is, the refraction point and the refraction angle of the main ray 420 are obtained.

(4) The distance (displacement Δ above) in the x direction between the (intra-eyeball) imaging position 421 and the optical axis of the eyeball (y-axis) in consideration of the refraction by the eyeball 400 (cornea) is obtained.

The above four calculation steps (1) to (4) are repeated while changing θ ₁ and θ ₂ until the magnitude of the displacement Δ (absolute value of the displacement Δ) becomes less than a predetermined threshold value. Here, the threshold value is set to, for example, 0.0001. By such an iterative calculation, a correction value of the main ray incident angle is obtained when the displacement Δ is sufficiently small, that is, when the image plane optical axis and the eyeball optical axis (illumination optical axis) substantially coincide with each other. Be done.

As an example of such an operation, the operation for the nuclear corresponding position will be described below. The nuclear correspondence position is θ = 38.11107 degrees. Further, the radius of curvature of the cornea of the eyeball 400 is set to r = 7.72 mm, and the refractive index of the eyeball is set to n = 1.337.

(1) First, θ ₁ and θ ₂ are set. Hypothetically set θ ₂ = 5 degrees. At this time, θ ₁ = θ − θ ₂ = 38.11107-5 = 33.11107 degrees.

(2) Next, the intersection of the main ray 420 and the air-equivalent image plane 410 is obtained, ignoring the refraction by the eyeball 400. For that purpose, first, an equation representing the air-converted image plane 410 and an equation representing the main ray 420 are obtained. Since the angle between the air-converted image plane 410 and the x-axis is 90-θ ₂ degrees, the formula for expressing the air-converted image plane 410 is y = (tan (90-θ ₂ )) x = (tan (90-90-). 5)) x = 11.43005x.

On the other hand, since the angle formed by the main ray 420 and the x-axis is 90 + θ ₁ degree, the inclination of the main ray 420 with respect to the nuclear correspondence position is tan (90 + θ ₁ ) = tan (90 + 33.11107) = −1.53333. Become.

The optical system design data is referred to in calculating the y-intercept (y = y _s ) of the main ray 420. an xy coordinate system origin (corneal vertex 401), the distance between the intersection of the principal ray 420 and the air equivalent image plane 410 represented by _{I m.} For example, the distance _{I m} is 0.00000mm next on the cornea corresponding position, the distance _{I m} is 1.81661mm next about the anterior capsule corresponding position, the distance _{I m} is 3.68280mm next Nuclear corresponding position, the posterior capsule corresponding position the distance _{I m} becomes 5.57288mm of.

See FIG. 20 here. In FIG. 20, the origin of the xy coordinate system (corneal apex 401), the intersection of the main ray 420 and the air-equivalent image plane 410, and the y-intercept (point of (x, y) = (0, y _s )) are shown. A triangle with three vertices is shown. Applying the sine theorem in the triangle, the value _{y s} y-intercept of Nuclear corresponding positions is calculated as _{follows: y s = I m · sin} (180-θ) / sinθ 1 = 3.68280 · sin (180-38.11107) / sin (38.11107) = 4.1609.

From the above, the formula representing the main ray 420 for the nuclear correspondence position is expressed as follows: y = −1.53333x + 4.1609. Therefore, the intersection of the principal ray 420 and the air equivalent image plane 410 for nuclear corresponding position coordinates _(x i, _{y i)} is the equation y = -1.53335x + 4.16096 representing the principal ray 420, air conversion image plane It is obtained by solving a system of equations consisting of the equation y = 11.43005x representing 410: (x _i , y _i ) = (0.32098, 3.66879). This is the end of the calculation step (2).

(3) Next, the refraction point and the refraction angle of the main ray 420 are obtained. The cornea of eye 400 is expressed by the following equation: x ² + (y-r) ² = r ² = 7.72 ² . The coordinates (x _c , y _c ) of the intersection of the cornea and the main ray 420 can be obtained by solving a simultaneous equation consisting of the equation representing the cornea and the equation representing the main ray 420. The coordinates of the intersection (x _c , y _c ) for the nuclear correspondence position are as follows: (x _c , y _c ) = (2.45277, 0.40001).

Subsequently, the incident angle and the exit angle of the main ray 420 at this intersection (x _c , y _c ) are obtained. For that purpose, first, the inclination of the tangent line 430 of the eyeball 400 (cornea) at the intersection (x _c , y _c ) is obtained. Nuclear corresponding position, the inclination of the tangent 430 of the curve ^{x 2 + (y-r)} 2 = 7.72 2 representing the cornea, the intersection _(x c, _{y c)} corresponds to the x derivative of. Differentiating the curve x ² + (y-r) ² = 7.72 ² representing the cornea by x gives the following equation: y'= x / (r ^2- x ² ) ^1/2 . By substituting the x coordinate x _c of the intersection (x _c , y _c ) into this x differential equation, the slope tan θ _y' = 0.33508 of the tangent line 430 is obtained, and θ _y' = arctan (0.33508) = 18.52486 is obtained.

Further, as can be seen from FIG. 21, with respect to the nuclear correspondence position, the incident angle θ _i of the main ray 420 at the intersection (x _c , y _c ) is θ _i = θ ₁ −θ _{y ′} = 33.11107-18.52486. = 14.58621.

Further, the nucleus corresponding position, the intersection _(x c, _{y c)} emission angle theta _{i 'is} obtained by using the Snell's law: theta _i' of the principal ray 420 in _{= arcsin ((sinθ i) /} n) = arcsin ((sin (14.58621)) /1.337) = 10.85705. This is the end of the calculation step (3).

(4) Finally, the distance (displacement Δ) in the x direction between the imaging position 421 in consideration of the refraction by the eyeball 400 and the optical axis of the eyeball is obtained. For that purpose, first, the intersection of the main ray 420 and the x-axis is found. Regarding the nuclear correspondence position, if y = 0 is set in the formula y = −1.53333x + 4.1609 that represents the main ray 420, the intersection (x ₀ , y ₀ ) between the main ray 420 and the x-axis is obtained as follows. : (X ₀ , y ₀ ) = (2.71364,0).

Next, the imaging position of the incident light beam when the refraction by the eyeball 400 is ignored is obtained. That is, the distance between the x-axis and the air-equivalent image plane 410 when the refraction by the eyeball 400 is ignored is obtained. Consider a triangle whose three vertices are the intersection of the main ray 420 and the x-axis, the intersection of the main ray 420 and the air-equivalent image plane 410, and the foot (perpendicular point) of the perpendicular line drawn from this intersection to the x-axis. To do. By applying the Pythagorean theorem to this triangle, the distance L between the x-axis and the air-equivalent image plane 410 can be found as follows: L = ((x ₀ − x _i ) ² + (y ₀ ) −Y _i ) ² ) ^1/2 = ((2.71364-0.32098) ² + (0-3.66879) ² ) ^1/2 = 4.38005.

Further, referring to FIG. 22, the distance Δ ₁ traveled in the x direction from the time when the main ray 420 passes through the x-axis until it is incident on the eyeball 400, that is, the point where the main ray 420 intersects the x-axis and the main ray 420 The x component Δ ₁ of the distance between the point where the eyeball 400 intersects with the eyeball 400 is obtained by the following calculation: Δ ₁ = | x _c − x ₀ | = | 2.45277-2.71364 | = 0.26087 ..

On the other hand, the distance delta ₁ the principal ray 420 travels in the y-direction until it enters the eyeball 400 after passing through the _x-axis, i.e., the principal ray 420 is the principal ray 420 and the point of intersection to the x-axis intersects the eye 400 The y component H ₁ of the distance between the points is H ₁ = | y _{c −} y ₀ | = 0.40001.

Therefore, the distance L ₁ from the time when the main ray 420 passes through the x-axis until it enters the eyeball 400, that is, the point where the main ray 420 intersects the x-axis and the point where the main ray 420 intersects the eyeball 400. The distance L ₁ between them is obtained by the following calculation: L ₁ = (Δ ₁ ² + H ₁ ² ) ^1/2 = (0.26087 ² + 0.40001 ² ) ^1/2 = 0.47755.

The difference between the distance L ₁ proceeding before entering the above, the distance L between the x-axis and the air equivalent image plane 410 when ignoring refraction, from the principal ray 420 passes through the x-axis to the eyeball 400 , the distance between the by multiplying the eyeball refractive index n, the length _{L 2} of the principal ray 420 of the eye 400, that is, and the imaging position 421 that the principal ray 420 intersects the eye 400 (cornea) L ₂ is obtained by the following calculation: L ₂ = (LL ₁ ) · n = (4.38005-0.47755) · 1.337 = 5.21764.

Further, the angle θ _n formed by the main ray 420 in the eyeball 400 with respect to the optical axis (y-axis) of the eyeball 400 is obtained by the following equation: θ _n = θ _y' + θ _i' = 18.52486 + 10.85705. = 29.38191.

Furthermore, the distance delta ₂ of the principal ray 420 in the eye 400 travels in the x direction is obtained by the following _{calculation: L 2 · sinθ n = 5.21764} · sin (29.38191) = 2.55992.

As a result, the distance Δ (target displacement Δ) in the x direction between the imaging position 421 and the eyeball optical axis (y-axis) in consideration of refraction by the eyeball 400 (eye to be inspected) can be obtained by the following equation: Δ = X ₀ −Δ ₁ −Δ ₂ = 2.71364-0.26087-2.55992 = 0.10715.

The magnitude of the displacement Δ thus obtained (absolute value of the displacement Δ) is compared with a predetermined threshold value (for example, 0.0001). In this example, since the displacement Δ = 0.10715> 0.0001, θ ₁ and θ ₂ are changed, and the four calculation steps (1) to (4) are executed again. This iterative operation is repeated until the magnitude of the displacement Δ becomes less than the threshold value. As a result, a correction value for the incident angle of the main ray 420 can be obtained when the displacement Δ is sufficiently small, that is, when the image plane optical axis and the eyeball optical axis (illumination optical axis) substantially coincide with each other.

The table below shows the values of various parameters for the corneal-corresponding position, anterior-sac-corresponding position, nuclear-corresponding position, and posterior-sac-corresponding position, which were obtained by the above-mentioned calculations to satisfy the displacement Δ <0.0001. Shown.

Based on the findings obtained from the above simulation, it is possible to set the deflection angle of the object surface due to the refractive index of the eye E to be inspected as follows.

First, the deflection angle of the object surface due to the refractive index of the eye to be inspected E is determined at least based on the angle formed by the optical axis of the illumination system 8 (illumination optical axis O2) and the optical axis of the imaging system 6 (imaging optical axis O1). May be done.

Here, the angle formed by the illumination optical axis O2 and the photographing optical axis O1 may be set to a value within a range larger than 0 degrees and 60 degrees or less. It is natural from the Scheimpflug principle that the angle range does not include 0 degrees. In addition, the maximum value of 60 degrees in the angle range is the finding obtained by the present inventors on anterior ocular segment imaging using the Scheimpflug principle, and an image of the range from the cornea to the crystalline lens can be obtained. This is a limit value of the angle formed by the illumination optical axis O2 and the photographing optical axis O1 that can be preferably acquired.

The deflection angle of the object surface due to the refractive index of the eye E to be inspected may be determined at least based on the radius of curvature of the cornea in addition to the angle formed by the illumination optical axis O2 and the photographing optical axis O1.

Here, the value of the radius of curvature of the cornea may be set based on a predetermined model eye. This model eye can be, for example, a Gullstrand model eye, a Navarro model eye, a Liou-Brennan model eye, a Badal model eye, an Arizona model eye, an Indiana model eye, an arbitrary standardized model eye, and any of these. It may be any of the equivalent model eyes.

Typically, as in the above calculation example, the value of the radius of curvature of the cornea may be set to a value within the range of, for example, 7.7 mm ± 0.5 mm based on the Gullstrand model eye.

The deflection angle of the object surface due to the refractive index of the eye E to be inspected may be determined at least based on the refractive index of the eyeball in addition to the angle formed by the optical axis O2 for illumination and the optical axis O1 for photographing.

Here, the value of the refractive index of the eyeball may be set based on a predetermined model eye. This model eye can be, for example, a Gullstrand model eye, a Navarro model eye, a Liou-Brennan model eye, a Badal model eye, an Arizona model eye, an Indiana model eye, an arbitrary standardized model eye, and any of these. It may be any of the equivalent model eyes.

Typically, as in the above calculation example, the value of the refractive index of the eyeball may be set to a value in the range of, for example, 1.336 ± 0.001 based on the Gullstrand model eye.

The deflection angle of the object surface due to the refractive index of the eye E to be inspected may be determined at least based on the radius of curvature of the cornea and the refractive index of the eyeball, in addition to the angle formed by the illumination optical axis O2 and the photographing optical axis O1.

Here, each of the value of the radius of curvature of the cornea and the value of the refractive index of the eyeball may be set based on a predetermined model eye as described above. Typically, as in the above calculation example, the value of the radius of curvature of the cornea is set to a value within the range of 7.7 mm ± 0.5 mm, and the value of the refractive index of the eyeball is set based on the Gullstrand model eye. It can be set to a value within the range of 1.336 ± 0.001.

The value of the corneal radius of curvature is set to a value within the range of 7.7 mm ± 0.5 mm, and the value of the refractive index of the eyeball is set to a value within the range of 1.336 ± 0.001. When the angle between the axis O2 and the shooting optical axis O1 is set to a value within the range of 60 degrees or less and larger than 0 degrees, the deflection angle of the object surface due to the refractive index of the eye E to be examined is from 0 degrees. Is also large and may be set to a value within the range of 11.09 degrees or less. Here, the fact that the deflection angle of the object surface is larger than 0 degrees is a matter naturally obtained from the principle of Scheimpflug. Further, the maximum value of 11.09 degrees in the deflection angle range is the corneal radius of curvature r = 7.2 mm, the refractive index n = 1.337, and the illumination optical axis O2 in the calculation steps (1) to (4). It is a value obtained by applying an angle θ = θ ₁ + θ ₂ = 60 degrees between the image and the optical axis O1 and performing an operation so that the displacement Δ <0.0001.

According to this aspect, deviation from the Scheimpflug condition due to the difference in refractive index inside and outside the eye to be inspected can be avoided with higher accuracy and higher accuracy than in the first to fifth aspects. ..

It is possible to combine any one or two or more of the first to fifth aspects with this aspect. Further, any known technique can be combined with the embodiment including at least a part of this embodiment, and modifications (addition, substitution, etc.) based on the arbitrary known technique can be performed. ..

<Other matters>
Some of the embodiments described above are merely examples. Therefore, it is possible to make arbitrary modifications (omission, substitution, addition, etc.) within the scope of the gist of the present invention.

For example, in some embodiments, the slit lamp microscope may be remotely controlled. Therefore, the slit lamp microscope includes, for example, a receiving unit, a control unit, and a transmitting unit.

The receiving unit of the slit lamp microscope of this embodiment receives an instruction from the first device via a communication line. The receiving unit includes at least a part of the above-mentioned communication unit. The first device includes, for example, an operation device for inputting an instruction for remotely controlling the slit lamp microscope, a computer for receiving the input instruction, and a transmitting device for transmitting the received instruction to the slit lamp microscope. ..

The control unit of the slit lamp microscope of this embodiment controls at least the illumination system and the photographing system according to the instruction received by the receiving unit. As a result, an image of the eye to be inspected can be obtained. The control unit includes at least a part of the computer 100.

The transmission unit of the slit lamp microscope of this embodiment transmits the image of the eye to be inspected obtained in response to an instruction or the data (image, analysis data, etc.) obtained by processing the image to the second device via a communication line. Send. The transmission unit includes at least a part of the communication unit described above. The second device includes at least a receiving device that receives an image or data transmitted from the slit lamp microscope, such as a storage device that stores the received image or data, a computer that processes the received image or data, and the like. Further included.

Instead of a configuration in which the direction of the optical axis of the photographing system can be changed like the slit lamp microscopes 200A and 200B, a light field camera is provided as an image pickup device, and the image obtained by this image pickup device is subjected to optical space image processing. At least the entire surface of the object may be obtained in focus.

It is possible to configure a program that causes a computer to execute a process relating to any one or a combination of any two or more of several embodiments. In addition, it is possible to configure a program that causes a computer to execute a process realized by applying modifications within the scope of the gist of the present invention to any one or a combination of any two or more of several embodiments. Is.

Further, it is possible to create a computer-readable non-temporary recording medium on which such a program is recorded. The non-temporary recording medium may be in any form, and examples thereof include a magnetic disk, an optical disk, a magneto-optical disk, and a semiconductor memory.

The present invention includes a method realized by any one of several aspects or a combination of any two or more. The present invention also includes a method realized by applying any modification within the scope of the gist of the present invention to any one or a combination of any two or more of several embodiments.

200, 200A, 200B, 200C, 200D Slit lamp microscope 6 Imaging system 6a Optical system 8 Illumination system O2 Illumination optical axis 43 Image sensor 60 Moving mechanism 61 Second deflection mechanism 70 First deflection mechanism 100 Computer 111 First deflection control unit 112 2nd deflection control unit 121 3D image construction unit 122 Rendering unit 123 Analysis unit 124 Image quality evaluation unit 125 Measurement unit 126 1st decision unit 127 2nd decision unit 128 3rd decision unit 129 4th decision unit 130 Data reception unit

Claims (32)

An illumination system that projects slit light onto the anterior segment of the eye to be inspected,
An imaging system including an optical system that guides light from the anterior segment to which the slit light is projected and an image pickup element that receives the light guided by the optical system on an imaging surface.
The object surface including the focal point of the illumination system displaced by the refractive index of the tissue of the anterior segment, the main surface of the optical system, and the imaging surface are arranged so as to satisfy the Scheimpflug condition. ,
Slit lamp microscope. Further including a moving mechanism for moving the lighting system and the photographing system,
The photographing system acquires a plurality of images of the anterior segment of the eye by repeatedly performing imaging in parallel with the movement of the lighting system and the photographing system by the moving mechanism.
The slit lamp microscope of claim 1. A three-dimensional image construction unit that constructs a three-dimensional image based on the plurality of images is further included.
The slit lamp microscope of claim 2. Further including a rendering unit that renders the three-dimensional image and constructs a rendered image.
The slit lamp microscope of claim 3. A unit including an analysis unit that applies a predetermined analysis process to at least one of the plurality of images or an image obtained by processing the plurality of images.
The slit lamp microscope according to any one of claims 2 to 4. The deflection angle of the object surface due to the refractive index is included in the range of 3 to 13 degrees.
The slit lamp microscope according to any one of claims 1 to 5. The deflection angle of the object surface due to the refractive index is included in the range of 6 to 10 degrees.
The slit lamp microscope of claim 6. The angle of deflection of the object surface due to the refractive index is determined at least based on the value of the radius of curvature of the cornea in a predetermined model eye and the value of the refractive index of the eye.
The slit lamp microscope according to any one of claims 1 to 7. The deflection angle of the object surface due to the refractive index is determined at least based on the angle formed by the optical axis of the lighting system and the optical axis of the photographing system.
The slit lamp microscope according to any one of claims 1 to 5. The angle is set to a value greater than 0 degrees and less than or equal to 60 degrees.
The slit lamp microscope of claim 9. The deflection angle of the object surface due to the refractive index is determined based on at least the angle and the radius of curvature of the cornea.
The slit lamp microscope according to claim 9 or 10. The value of the radius of curvature of the cornea is set based on a predetermined model eye.
The slit lamp microscope of claim 11. The value of the radius of curvature of the cornea is set to a value within the range of 7.7 mm ± 0.5 mm based on the Gullstrand model eye.
The slit lamp microscope of claim 12. The angle of deflection of the object surface due to the refractive index is determined at least based on the angle and the refractive index of the eyeball.
The slit lamp microscope according to claim 9 or 10. The value of the refractive index of the eyeball is set based on a predetermined model eye.
The slit lamp microscope of claim 14. The value of the refractive index of the eyeball is set to a value within the range of 1.336 ± 0.001 based on the Gullstrand model eye.
The slit lamp microscope of claim 15. The angle of deflection of the object surface due to the refractive index is determined at least based on the angle, the radius of curvature of the cornea, and the refractive index of the eyeball.
The slit lamp microscope according to claim 9 or 10. Each of the value of the radius of curvature of the cornea and the value of the refractive index of the eyeball are set based on a predetermined model eye.
The slit lamp microscope of claim 17. Based on the Glucland model eye, the value of the radius of curvature of the cornea is set to a value within the range of 7.7 mm ± 0.5 mm, and the value of the refractive index of the eyeball is 1.336 ± 0.001. Set to a value within the range,
The slit lamp microscope of claim 18. The deflection angle is set to a value greater than 0 degrees and within the range of 11.09 degrees or less.
The slit lamp microscope of claim 19. A first deflection mechanism for changing the direction of the optical axis of the photographing system is further provided.
The slit lamp microscope according to any one of claims 1 to 20. The first deflection mechanism substantially rotates the optical axis of the photographing system around the intersection of the object surface and the optical axis of the photographing system.
The slit lamp microscope of claim 21. An image quality evaluation unit that analyzes the image of the eye to be inspected acquired by the photographing system and evaluates the image quality.
Further including a first deflection control unit that controls the first deflection mechanism based on at least the result of evaluation by the image quality evaluation unit.
The slit lamp microscope of claim 21 or 22. A measuring unit that analyzes the image of the eye to be inspected acquired by the photographing system and measures the radius of curvature of the cornea.
A first determination unit that determines the target direction of the optical axis of the photographing system based on at least the result of measurement by the measurement unit.
Including
The first deflection mechanism changes the direction of the optical axis of the photographing system to the target direction.
The slit lamp microscope according to any one of claims 21 to 23. A data receiving unit that receives measurement data of the corneal radius of curvature of the eye to be inspected in advance,
A second determination unit that determines the target orientation of the optical axis of the photographing system based on at least the measurement data, and
Including
The first deflection mechanism changes the direction of the optical axis of the photographing system to the target direction.
The slit lamp microscope according to any one of claims 21 to 23. The photographing system starts photographing the front eye portion in response to the change of the direction of the optical axis of the photographing system by the first deflection mechanism.
The slit lamp microscope according to any one of claims 21 to 25. A second deflection mechanism for changing the direction of the optical axis of the lighting system is further provided.
The slit lamp microscope according to any one of claims 1 to 20. The second deflection mechanism rotates the optical axis of the illumination system around the intersection of the cornea of the eye to be inspected and the optical axis of the illumination system.
The slit lamp microscope of claim 27. An image quality evaluation unit that analyzes the image of the eye to be inspected acquired by the photographing system and evaluates the image quality.
Further includes a second deflection control unit that controls the second deflection mechanism based on at least the result of evaluation by the image quality evaluation unit.
The slit lamp microscope of claim 27 or 28. A measuring unit that analyzes the image of the eye to be inspected acquired by the photographing system and measures the radius of curvature of the cornea.
Further including a third determination unit that determines the target direction of the optical axis of the lighting system based on at least the result of measurement by the measurement unit.
The second deflection mechanism changes the direction of the optical axis of the lighting system to the target direction.
The slit lamp microscope according to any one of claims 27 to 29. A data receiving unit that receives measurement data of the corneal radius of curvature of the eye to be inspected in advance,
It further includes a fourth determination unit that determines the target orientation of the optical axis of the illumination system based on at least the measurement data.
The second deflection mechanism changes the direction of the optical axis of the lighting system to the target direction.
The slit lamp microscope according to any one of claims 27 to 29. The photographing system starts photographing the front eye portion in response to the change of the direction of the optical axis of the lighting system by the second deflection mechanism.
The slit lamp microscope according to any one of claims 27 to 31.

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