JP2014012036A - Slit lamp microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slit lamp microscope that can favorably obtain a captured image of an eye.SOLUTION: A slit lamp microscope comprises: an illumination optical system having an illumination light source for illuminating an eye; an observation optical system for observing a subject eye illuminated by the illumination light source; an imaging optical system having an imaging element for imaging the eye illuminated by the illumination light source; a filter arranged insertably and removably in an optical path of the illumination optical system or the imaging optical system; a filter detection part for detecting a filter placed in the optical path; and gain adjustment means for adjusting, according to a filter detection signal provided by the filer detection part, a gain of a signal outputted from each pixel of the imaging element.

Description

  The present invention relates to a slit mirror microscope for observing or photographing a subject's eye.

  In the slit microscope, various filters are detachably provided in an optical path such as an optical system in order to observe the state of the subject's eye. For example, in order to observe the state of a subject's eye that has been instilled with a fluorescent agent, a blue filter having a blue wavelength band is provided in the illumination system so that it can be inserted and removed (for example, Patent Document 1). reference).

JP-A-6-277179

  When a subject's eye is imaged using an imaging device in a state where a filter is disposed in the optical path of the illumination optical system, it is required that an image corresponding to the purpose is acquired. For example, in imaging of a subject's eye through a visible blue transmission filter, it is required to acquire an image in which the vicinity of the fluorescence emission wavelength band of the subject's eye is emphasized.

  An object of the present invention is to provide a slit mirror microscope capable of suitably obtaining a photographed image of a subject's eye in view of the above-described problems of the prior art.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) An illumination optical system having an illumination light source for illuminating the subject's eye, an observation optical system for observing the subject's eye illuminated by the illumination light source, and a subject eye illuminated by the illumination light source In a slit mirror microscope comprising an imaging optical system having an imaging device for imaging, a filter provided in a removable manner in the optical path of the illumination optical system or the imaging optical system, and a filter placed in the optical path And a gain adjusting means for adjusting a gain of a signal output from each pixel of the image pickup device in accordance with a detection signal of the filter by the filter detection unit.
(2) The gain adjusting unit amplifies the gain of the signal output from the pixel corresponding to the wavelength band of the excitation light by the light beam transmitted through the filter, and other than the wavelength band of the excitation light shielded by the filter The slit mirror microscope according to (1), wherein a gain of a signal output from the pixel corresponding to a wavelength band is reduced.
(3) The filter is a blue filter that transmits visible blue, and the gain correction unit amplifies the gain of the signal output from the green pixel of the image sensor and is output from the red and blue pixels. The slit mirror microscope according to (2), wherein correction is performed to reduce a gain of a signal to be transmitted.
(4) output means for outputting information of the eye of the subject imaged by the imaging device, the output means imaging the usage information of the filter based on a detection signal from the filter detection unit. The slit mirror microscope according to any one of (1) to (3), which is output together with an image captured by an element.
(5) The slit mirror microscope according to any one of (1) to (4), wherein the output unit outputs information on the image and the filter to an electronic medical record.
(6) The gain adjusting unit amplifies the gain of the signal output from the pixel corresponding to the wavelength band of the light beam that has passed through the filter, and is output from the pixel corresponding to the wavelength band shielded by the filter. The slit mirror microscope according to (1), wherein the gain of the signal is reduced.

  According to the present invention, a captured image of a subject's eye can be suitably obtained in a slit microscope.

  Embodiments according to the present invention will be described below with reference to the drawings. Here, a slit mirror microscope (hereinafter referred to as a slit lamp) will be described as an example of an ophthalmologic apparatus. FIG. 1 is an explanatory view of the appearance of a slit lamp. FIG. 2 is an explanatory diagram of the optical system of the slit lamp. FIG. 3 is a cross-sectional view of the slit lamp of FIG. 1 as viewed by cutting along the axis AA. FIG. 4 is a perspective view of the internal configuration of the main body 100b.

  The slit lamp 100 is roughly divided into a face support unit 100a and a main body 100b. The face support unit 100a provided on the subject side has a forehead support 11 for supporting the subject's forehead and a chin rest 12 for supporting the chin, and is fixed to the table 1 via two columns 13. ing. The main body 100b has a movable part 200b whose height in the vertical direction is adjusted with respect to the table 1, and a fixed part 200a that supports the movable part 200b. A control unit 85 that controls the operation of the illumination unit 60, the microscope unit (observation / photographing unit) 70, and the slit lamp 100 as a whole is provided in the casing of the movable unit 200b. A vertical movement mechanism 200 for moving the movable part 200b up and down with respect to the eye E is provided in the housing of the fixed part 200a.

  The illumination unit 60 includes a visible light source 61, a condenser lens 62, a variable aperture 63, a variable slit 64, a projection lens 65, and a prism mirror 66, and illuminates the observation site of the subject eye E. The light beam (visible light) from the light source 61 passes through the condenser lens 62 and illuminates the variable aperture 63 and the variable slit 64. The light beam that has passed through the aperture 63 and the slit 64 passes through the projection lens 65, is reflected by the prism mirror 66, and is projected onto the eye E. As the visible light source 61, a known lamp such as a halogen lamp or LED is used.

  A blue filter (blue transmission filter) 90 is detachably provided between the slit 64 of the illumination unit 60 and the projection lens 65. For the blue filter 90, for example, a filter that transmits visible blue of 470 to 500 nm is used. By using a filter that transmits a specific wavelength band (blue), an image in which the affected area is emphasized by excitation light is acquired. A position sensor 91 is provided at a position where the insertion of the filter 90 can be detected when the blue filter 90 is inserted into the optical path. For example, the sensor 91 is an optical element such as a photo interrupter or a known position detection element such as a switch. Note that the blue filter 90 may be disposed in the optical path of the illumination optical system, and may be disposed in a position other than the position shown in FIG. 2 in the optical path.

  The microscope unit 70 includes an objective lens 71, a variable magnification optical system 72, a half mirror 73, an imaging lens 74, an erecting prism 75, a field stop 76, and an eyepiece lens 77. The light beam reflected by the eye E passes through the objective lens 71, the variable magnification optical system 72, the half mirror 73, and the imaging lens 74, and is reflected by the erecting prism 75. The light beam reflected by the prism 75 passes through the field stop 76 and the eyepiece lens 77 and enters the eye F of the examiner.

  The light beam reflected by the half mirror 73 passes through the relay lens 78 and enters the camera (imaging device) 80. As the image sensor 80, a known digital camera or the like provided with a CCD having sensitivity to visible light is used. The control unit 85 captures a captured image of the image sensor 80 based on a command signal from a switch 22a described later, and displays the captured image on the monitor 87.

  The up-and-down moving mechanism 200 of the fixed portion 200a includes a base 21 fixed to the table 1, a casing 21a provided so as to be slidable with respect to the base 21, and a part of the casing 21a installed in the casing 21a. Is provided with a joystick 22 that is an operation member that appears outside through an opening (not shown), and a drive unit 50 installed in the housing 21a.

  The joystick 22 is inserted through the joystick 22 in a substantially vertical direction (Y direction), a grip (rotating unit) 22a that is gripped and rotated by an examiner, a switch 22b that inputs a trigger signal for photographing (image acquisition), and the like. It comprises a shaft (support member) 22c and a known rotary encoder 22d that detects the rotation angle of the grip 22a.

  The drive unit 50 is a hollow brushless motor (hereinafter referred to as a motor) 51 that is fixed to the housing 21 a and is provided to be rotatable about the rotation axis L <b> 1, and a drive detection unit that detects the rotation of the motor 51. It has a sensor 56. A female screw 51b is formed at a predetermined pitch in the hollow portion of the hollow brushless motor 51, and the female screw 51b is coupled to a shaft 52 (male screw 52a) on the movable part 200b side described later. When the female screw 51b rotates with the rotation of the motor 51, the shaft 52 (male screw 52a) is moved in the vertical (up and down) direction via the female screw 51b. Then, the vertical height of the movable portion 200b is changed in conjunction with the vertical movement of the male screw 52a.

  The movable part 200 b includes a base shaft 23 that extends substantially perpendicular to the base 21, an arm 24 that supports the illumination unit 60, and an arm 25 that supports the microscope unit 70. The arm 24 and the arm 25 are supported so as to be individually rotatable in the horizontal direction around the central axis B, whereby the illumination unit 60 and the microscope unit 70 are individually rotated around the central axis B.

  A shaft 52 inserted through the female screw 51b of the motor 51 is fixed below the movable portion 200b. A feed screw (male screw) 52a having a predetermined pitch is formed at the tip of the shaft 52 and is fitted to the female screw 51b. When the rotation of the female screw 51b is transmitted to the male screw 52a, the movable part 200b is moved up and down in a predetermined step.

  The male screw 52a only needs to be formed in a predetermined range on the shaft 52 so that it does not come off the female screw 51b when the movable part 200b reaches the upper limit or the lower limit of the moving range.

  Note that the lead angles of the female screw 51b and the male screw 52a are formed such that when the vertical movement of the movable part 100b is stopped, the movable part 200b is not pushed down by its own weight and exhibits a frictional force that maintains the position. The lead angle is determined in consideration of the minimum vertical movable width of the movable part 200b. That is, when the lead angle is narrow, the movable portion 200b is vertically aligned in finer steps. On the other hand, when the lead angle is narrowed, there is a disadvantage that it takes time to move the movable part 200b up and down. The lead angle may be determined in consideration of the above conditions. Furthermore, the lead angles of the female screw 51b and the male screw 52a are preferably determined in consideration of the material, the state of grease, and the like.

  Further, in the present embodiment, the main body portion 100a is provided with a support portion for stabilizing the vertical movement of the movable portion 200b. For example, the support portion is a combination of a cylindrical portion 231 fixed to the fixed portion 200a and a shaft 232 that passes through the hollow formed inside the cylindrical portion 231 and is fixed to the movable portion 200b side. Composed.

  When the movable portion 200b moves up and down, the shaft 232 fixed to the movable portion 200b moves in the vertical direction along the inner wall of the cylindrical portion 231. As a result, the movable portion 200b is held by the plurality of support members, and the vertical movement operation is further stabilized.

  Further, in the present embodiment, the main body 100a is provided with a position detector for detecting the vertical position of the movable part 200b with respect to the fixed part 200a. For example, the position detection unit includes three sensors having a plate portion 54 that is fixed on the movable portion 200b side and moved up and down in conjunction with the movable portion 200b, and an opening that is fixed on the fixed portion 200a side and through which the plate portion 54 passes. 55a-55c.

  When the movable portion 200b is moved up and down and the plate portion 54 is detected by all three sensors 55a to 55c, the control portion 85 detects that the movable portion 200b is at the lower limit. When the plate portion 54 is detected only by the sensor 55a, it is detected that the movable portion 200b is at the upper limit. Further, in the present embodiment, when the plate portion 54 is detected by the sensors 55a and 55b and is not detected by the sensor 55c, the main body portion 100a is assumed to be at an intermediate position (position of an eye level marker not shown) in the movable range.

That is, when a switch (not shown) is pressed for initial alignment of the main body 100a, the motor 50 is driven to move the movable part 200b up and down until the plate part 54 is detected by the sensors 55a and 55b. It is easily adjusted automatically.
As the sensor, a known sensor such as an optical sensor such as a photo interrupter, a magnetic sensor, or a mechanical sensor is used.

  With the above configuration, when the joystick 22 is slid in the horizontal direction (front / rear / left / right direction) by the examiner's operation, the main body 100b moves in the horizontal direction with respect to the eye E by a known slide mechanism. On the other hand, when the grip 22a is rotated in the horizontal direction around the shaft 22b, the rotation direction, the rotation speed, and the like are detected by the encoder 22d. Based on the output signal from the encoder 22d, the control unit 85 rotates the motor 51 (rotor 57) based on the correspondence between the rotation amount of the grip 22d and the rotation amount of the motor 51 (rotor 57) stored in the memory 81 described later. To control. When the rotor 57 is rotated by the drive control of the control unit 85, the male screw 52a is moved up and down along the female screw 51b formed in the hollow portion 51a, and the entire movable unit 200b is moved up and down.

  The control unit 85 controls the drive of the entire apparatus. The control unit 85 is connected to the above-described grip 22a, switch 22b, encoder 22d, sensors 55a to 55c, motor 51, sensor 56, monitor 87, sensor 91, memory 81, and the like.

  The controller 85 directly controls the rotation amount and rotation direction of the motor 51 based on the input signal from the joystick 22. Further, the control unit 85 detects the rotation state of the motor 51 based on the rotation amount and rotation speed of the motor 51 detected by the sensor 56 and performs control to correctly operate based on the input signal from the joystick 22.

  Further, the control unit 85 recognizes that the filter 90 is disposed in the optical path of the illumination unit 60 in accordance with a signal from the sensor 91. Further, when the filter 90 is detected, the control unit 85 adjusts the gain of the image sensor 80 on the assumption that the photographing mode has been switched. Here, it is recognized that the normal photographing mode has been switched to the fluorescent photographing mode.

  In photographing without passing through a normal filter, the eye E is illuminated with illumination light having a wide wavelength band. On the other hand, in the case of photographing through a filter, the wavelength band of illumination light is limited, and the amount of light is insufficient, and it may be difficult to obtain a clear image. In view of this, the prior art has proposed a method for increasing the amount of illumination light to ensure the amount of light in photographing through a filter. However, a normal filter has a characteristic that the transmitted light amount at the center wavelength in the wavelength band is maximized and the transmitted light amount is gradually attenuated as the distance from the center wavelength increases. For this reason, when the amount of illumination light is increased, the light flux of noise components other than the light flux having the wavelength band required for photographing is also increased, and the photographed image is not clearly obtained.

  On the other hand, there may be a method in which the examiner manually adjusts the gain of the pixel of the image sensor according to the photographing conditions, but it is necessary to reset the setting every time the photographing conditions are changed, which takes time and effort for the examiner. Is a burden. In addition, if there is a mistake in setting the gain of the pixel of the image sensor, there is a risk of failure of shooting. Similarly, it is conceivable to adjust the image quality of the captured image acquired by the image sensor using an image processing apparatus such as a personal computer.

  Therefore, the present invention increases the gain of the pixel of the imaging element in the wavelength band (color) corresponding to the light flux in the wavelength band that has passed through the filter when shooting through the filter. Alternatively, the gain of the pixel of the imaging element in the wavelength band (color) corresponding to the excitation light by the light flux in the wavelength band that has passed through the filter is increased. On the other hand, the gain of the pixel of the imaging device in the wavelength band (color) corresponding to the light flux in the wavelength band shielded by the filter is reduced. Alternatively, the gain of the pixel of the image sensor corresponding to a wavelength band (color) other than the wavelength band (color) of the excitation light is decreased.

  That is, the gain adjustment is performed so that the gain of the green pixel 80b corresponding to the light beam in the green wavelength band excited by the blue light beam of the filter 90 is increased and the gain of the red pixel 80a and the blue pixel 80c is decreased. Is done. In this way, noise light can be suppressed and a captured image corresponding to the transmission characteristics of the filter can be obtained. Further, the gain of the image sensor is automatically adjusted by the filter detection, so that it is possible to save the trouble of setting the examiner and to suppress the occurrence of imaging defects.

  In addition, while gain correction and color correction performed on a personal computer target an image including a noise component acquired in advance by an image sensor, the present invention performs gain and color correction when acquiring an image by the image sensor. Is done. Therefore, an image from which noise components have been removed in advance is acquired, so that the image quality is improved as compared with correction by a personal computer or the like.

  Next, using the slit mirror microscope as described above, an operation in the case of photographing the subject's eye with the filter installed will be described. First, the filter 90 is inserted from a slit (not shown) of the main body 100b, and an eye drop (fluorescent agent) is instilled into the patient's eye. When the detection signal of the sensor 91 is detected by the control unit 85, the fluorescent photographing mode is recognized. The control unit 85 adjusts the gain of the image sensor 80. Here, the gain of the green pixel 80b is set high, and the gain of the red pixel 80a and the blue pixel 80c is set low.

  When the preparation for photographing is completed and the light source 61 is turned on, the light beam from the light source 61 enters the filter 90 from the condenser lens 62 through the projection lens 65. The filter 90 transmits only the wavelength component in the blue predetermined band out of the light flux emitted from the light source 61. The blue component light beam transmitted through the filter 90 illuminates the subject's eye E through the prism mirror 66. The green excitation light from the subject eye E instilled with the fluorescent agent is reflected by the half mirror 73 through the objective lens 71. The reflected light is imaged by the image sensor 80 through the relay lens 78.

At this time, since only the gain of the green pixel 80b of the image sensor 80 is increased, a green (fluorescent) captured image is acquired in a clearer state. An image acquired by the image sensor 38 is stored in the memory 81. At this time, it is assumed that usage information of the filter 90 based on the detection signal of the sensor 91 is also stored.
When the filter 90 is removed from the optical path of the illumination unit 60, the control unit 85 recognizes that the shooting mode has been returned to the normal shooting according to the detection signal from the sensor 91, and returns the gain adjustment of the image sensor 80. Process.

  In addition, the illumination light quantity of the light source 61 may be increased with the gain adjustment of the image sensor 80. In the present invention, since only the gain of the pixel of the image sensor 80 in the wavelength band transmitted through the filter is increased, a clearer image can be obtained while suppressing the influence of noise light.

  Note that the photographed image stored in the memory 81 is output together with the photographing information. For example, the captured image of the memory 81 and the use information of the filter based on the detection result of the sensor 91 are externally output via an external storage medium (not shown), LAN, or the like. In this case, fluorescence imaging information is added to the captured image 83, and management of the captured image by the examiner is facilitated. For example, the use information of the filter includes information indicating that the blue filter is used in shooting, and information indicating that the image is a shot image shot using the blue filter, and is output together with the shot image. In addition, when outputting on an electronic medical chart via a personal computer, a picked-up image and the usage information of a filter are simply displayed on a predetermined display column. In addition, the collection of photographing information by an electronic medical record is more accurately performed, and the usability of the examiner is improved.

  In the above, an example using a blue filter used for fluorescence, staining reaction observation, etc. has been shown. In addition to this, the configuration of the present invention is applied to various types of filters used in the slit microscope, so that the image sensor can be easily set to be suitable for photographing, and a clear image can be obtained. You can get it. For example, in the optical path of the illumination optical system, a non-red filter (green filter) used for inspecting abnormalities of the optic nerve fiber is disposed. In the optical path of the observation / photographing optical system, a yellow filter or the like for suppressing the blue light for excitation by combining with a blue filter and making the fluorescent image easier to see is disposed.

  When a plurality of filters are arranged, it is preferable that the detection unit can determine which filter is arranged in the optical path and used for photographing in addition to the presence or absence of the filter. In this case, the captured image and filter usage information including which filter is used are output to the outside. When determining one filter from a plurality of filters, for example, the type of the filter can be determined by detecting the position of the rotating disk on which the plurality of filters are arranged.

  By performing the control as described above, it is possible to obtain a clear image in which the influence of noise light is suppressed. In addition, the filter detection information is output together with the captured image, thereby facilitating management of the captured image. Furthermore, even if it is a weak (small) fluorescent portion that is likely to be overlooked by the naked eye observation through the microscope unit 70, the gain of the image acquired by the image sensor 80 is appropriately adjusted, so that it is displayed on a monitor such as a personal computer. By highlighting, it helps to understand the pathology more accurately.

  When a plurality of filters are used for one shooting, such as a combination of an exciter filter and a barrier filter, the gain adjustment of the image sensor may be performed based on the detection result of at least one filter.

  In the above configuration, the example in which the position sensor 91 for detecting the insertion of the filter 90 is provided is shown. In addition to this, the insertion of the filter 90 may be detected based on a captured image of the image sensor 80. That is, the characteristics of the luminance distribution of the pixels of the image sensor 80 when each filter 90 is inserted are stored in the memory 81 in advance, and the arrangement of various filters is detected based on information from the image sensor 80 without providing the position sensor 91. You may do it.

It is explanatory drawing of the external appearance of a slit lamp. It is explanatory drawing of the optical system of a slit lamp. It is sectional drawing of a slit lamp. It is a perspective view of the internal structure of a slit lamp main body.

60 Illumination Unit 70 Microscope Unit 90 Filter 91 Sensor 80 Image Sensor 80a Red Pixel 80b Green Pixel 80c Blue Pixel 85 Control Unit 100 Slit Lamp

Claims (6)

An illumination optical system having an illumination light source for illuminating the subject's eye;
An observation optical system for observing the eye of the subject illuminated by the illumination light source;
An imaging optical system having an image sensor for imaging the eye of the subject illuminated by the illumination light source;
In a slit mirror microscope comprising:
A filter that is detachably provided in an optical path of the illumination optical system or the photographing optical system;
A filter detection unit for detecting a filter placed in the optical path;
A slit mirror microscope comprising: a gain adjusting unit that adjusts a gain of a signal output from each pixel of the image pickup device in accordance with a detection signal of the filter by the filter detection unit.   The gain adjusting unit amplifies a gain of a signal output from a pixel corresponding to a wavelength band of excitation light by a light beam transmitted through the filter, and sets the gain band to a wavelength band other than the wavelength band of the excitation light shielded by the filter. The slit mirror microscope according to claim 1, wherein a gain of a signal output from the corresponding pixel is reduced. The filter is a blue filter that transmits visible blue color,
3. The slit according to claim 2, wherein the gain correction unit performs correction to amplify a gain of a signal output from a green pixel of the image sensor and reduce a gain of a signal output from a red pixel and a blue pixel. Mirror microscope. Output means for outputting information of the eye of the subject imaged by the imaging element;
The slit mirror microscope according to any one of claims 1 to 3, wherein the output unit outputs use information of the filter based on a detection signal from the filter detection unit together with an image captured by the image sensor.   The slit mirror microscope according to any one of claims 1 to 4, wherein the output means outputs information of the image and the filter to an electronic medical record. The gain adjusting means amplifies the gain of the signal output from the pixel corresponding to the wavelength band of the light beam transmitted through the filter, and the gain of the signal output from the pixel corresponding to the wavelength band shielded by the filter The slit mirror microscope according to claim 1, wherein

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