JP6912554B2 - Ophthalmic equipment - Google Patents

Description

The present invention relates to an ophthalmic apparatus.

In ophthalmic examinations (including any action to obtain data on the eye to be inspected, such as examination, measurement, imaging, etc.), fixation is performed to inspect the desired part of the eye to be inspected. Fixation is realized by having the subject gaze at the fixation target presented in a predetermined direction.

Fixation includes internal fixation, external fixation, and peripheral fixation. Internal fixation is a fixation method in which a bright spot image formed by a dot-matrix liquid crystal display (LCD) or a matrix light-emitting diode (LED) is projected onto the fundus of the eye through an objective lens of an inspection optical system. It has the feature that the shape and position of the marker (called the internal fixation target) can be set in detail. External fixation is performed using a light source (LED, etc.) provided on the outside of the housing in which the inspection optical system is housed. It is a fixation method that adjusts the direction of the LED. Peripheral fixation is performed using a plurality of light sources (LEDs, etc.) arranged around the objective lens, and by selectively lighting these light sources, the eye to be inspected is greatly rotated in a desired direction. be. Peripheral fixation is used in the examination of the area around the fundus.

Patent Document 1 discloses a technique for changing the size of an internal fixation target while moving it in order to prevent the subject from losing sight of the moving internal fixation target.

Japanese Unexamined Patent Publication No. 2004-141563

The scene where the visibility of the internal fixation target should be considered is not limited to the movement. For example, when aligning the inspection optical system with respect to the eye to be inspected, the inspection optical system (optical head) is brought closer to the eye to be inspected while the internal fixation target is presented. When the internal fixation light flux passes through a position away from the optical axis of the objective lens, such as when examining the optic nerve head, the internal fixation light flux reaches the fundus when the distance between the optical head and the eye to be inspected is short. When the distance is long, the internal fixation light flux does not reach the fundus. That is, as the optical head is brought closer to the eye to be inspected, an internal fixation target suddenly appears at the edge of the field of view at a certain stage. Therefore, the subject may not be able to recognize the internal fixation target, and the alignment may not be performed properly. In addition, when the internal fixation target enters the field of view, the eye to be inspected suddenly rotates and flare occurs in the observed image, which may interfere with the observation and alignment of the eye to be inspected.

One object of the ophthalmic apparatus according to the present invention is to improve the visibility of the internal fixation target.

The ophthalmic apparatus of the embodiment includes an optical system, a moving mechanism, and a control unit. The optical system includes an objective lens, an irradiation optical system that irradiates one eye to be inspected with light through the objective lens, and a fixation system that projects a fixation light beam onto the one eye to be inspected through the objective lens. .. The moving mechanism is capable of three-dimensionally moving at least a part of the optical system including the objective lens. The control unit controls the fixation system for changing the shape of the fixation flux while controlling the movement mechanism for alignment of the optical system with respect to one eye to be inspected.

According to the embodiment, it is possible to improve the visibility of the internal fixation target.

The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The schematic diagram which shows an example of the structure of the ophthalmic apparatus which concerns on embodiment. The flow chart which shows an example of the operation of the ophthalmic apparatus which concerns on embodiment. The schematic diagram for demonstrating an example of the operation of the ophthalmic apparatus which concerns on embodiment. The schematic diagram for demonstrating an example of the operation of the ophthalmic apparatus which concerns on embodiment. The schematic diagram for demonstrating an example of the operation of the ophthalmic apparatus which concerns on embodiment.

Some embodiments of the present invention will be described in detail with reference to the drawings. The embodiment may be any ophthalmic apparatus including an irradiation optical system that irradiates an eye to be inspected with light through an objective lens and a fixation system that projects a fixation light flux to the eye to be inspected through an objective lens. .. Examples of such an ophthalmic apparatus include an optical coherence tomography (OCT), a fundus camera, a scanning laser ophthalmoscope (SLO), a laser treatment apparatus (photocoagulation apparatus), and a perimeter. The OCT, fundus camera, and SLO are further provided with an optical system for detecting the return light of the light emitted by the irradiation optical system from the eye to be inspected. Hereinafter, an ophthalmic apparatus in which a swept source OCT and a fundus camera are combined will be described, but the embodiment is not limited thereto.

<Constitution>
As shown in FIG. 1, the ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic control unit 200. The fundus camera unit 2 is provided with an optical system substantially similar to that of a conventional fundus camera. The OCT unit 100 is provided with an optical system and a mechanism for executing OCT. The arithmetic control unit 200 includes a processor. A chin rest and a forehead pad for supporting the subject's face are provided at positions facing the fundus camera unit 2.

In the present specification, 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), a programmable logic device (for example, a SPLD). (Complex Program 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 stored in a storage circuit or a storage device, for example.

<Fundus camera unit 2>
The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef of the eye to be inspected E. Images obtained by photographing the fundus Ef (called a fundus image, a fundus photograph, etc.) include an observation image and a photographed image. The observation image is obtained, for example, by taking a moving image using near-infrared light. The captured image is, for example, a color image or a monochrome image obtained by using a visible flash light, or a monochrome image obtained by using a near-infrared flash light. The fundus camera unit 2 may also be capable of acquiring a fluorescein fluorescence image, an indocyanine green fluorescence image, a spontaneous fluorescence image, or the like.

The fundus camera unit 2 includes an illumination optical system 10 and a photographing optical system 30. The illumination optical system 10 irradiates the eye E to be inspected with illumination light. The photographing optical system 30 detects the return light of the illumination light from the eye E to be inspected. The measurement light from the OCT unit 100 is guided to the eye E to be inspected through the optical path in the fundus camera unit 2, and the return light is guided to the OCT unit 100 through the same optical path.

The observation light source 11 of the illumination optical system 10 is, for example, a halogen lamp or an LED (Light Emitting Diode). The light output from the observation light source 11 (observation illumination light) is reflected by the reflection mirror 12 having a curved reflecting surface, passes through the condenser lens 13, passes through the visible cut filter 14, and becomes near-infrared light. Become. Further, the observation illumination light is once focused in the vicinity of the photographing light source 15, reflected by the mirror 16, and passes through the relay lenses 17, 18, the diaphragm 19, and the relay lens 20. Then, the observation illumination light is reflected at the peripheral portion of the perforated mirror 21 (the region around the perforated portion), passes through the dichroic mirror 46, is refracted by the objective lens 22, and the eye E to be inspected (particularly the fundus Ef) is exposed. Illuminate.

The return light of the observation illumination light from the eye E to be inspected is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central region of the perforated mirror 21, and passes through the dichroic mirror 55. , It is reflected by the mirror 32 via the photographing focusing lens 31. Further, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the CCD image sensor 35 by the condenser lens 34. The CCD image sensor 35 detects the return light at a predetermined frame rate, for example. When the photographing optical system 30 is in focus on the fundus Ef, an observation image of the fundus Ef is obtained, and when the focus is on the anterior segment of the eye, an observation image of the anterior segment is obtained.

The photographing light source 15 is, for example, a visible light source including a xenon lamp or an LED. The light output from the photographing light source 15 (photographing illumination light) is applied to the fundus Ef through the same path as the observation illumination light. The return light of the photographing illumination light from the eye E to be examined is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by the mirror 36, and is reflected by the condenser lens 37. An image is formed on the light receiving surface of the CCD image sensor 38.

The LCD 39 displays an fixation target for fixing the eye E to be inspected. A part of the light flux (fixed-view light flux) output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the photographing focusing lens 31 and the dichroic mirror 55, and is a hole of the perforated mirror 21. Pass through the department. The solid-view light flux that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fixation position of the eye E to be inspected can be changed by changing the display position of the fixation target on the screen of the LCD 39.

The luminous flux output unit that outputs the solid-view luminous flux is not limited to the LCD 39. The luminous flux output unit may have a configuration in which the fixation position can be changed, for example, a matrix LED in which a plurality of LEDs are two-dimensionally arranged, a combination of a light source and a variable diaphragm (liquid crystal diaphragm, etc.), and the like. You can.

The fundus camera unit 2 is provided with an alignment optical system 50 and a focus optical system 60. The alignment optical system 50 generates an alignment index used for alignment of the optical system with respect to the eye E to be inspected. The focus optical system 60 generates a split index used for focus adjustment with respect to the eye E to be inspected.

The alignment light output from the LED 51 of the alignment optical system 50 passes through the diaphragms 52 and 53 and the relay lens 54, is reflected by the dichroic mirror 55, and passes through the hole portion of the perforated mirror 21. The light that has passed through the hole of the perforated mirror 21 passes through the dichroic mirror 46 and is projected onto the eye E to be inspected by the objective lens 22.

The corneal reflected light of the alignment light passes through the objective lens 22, the dichroic mirror 46, and the above-mentioned hole, and a part of the light passes through the dichroic mirror 55, passes through the photographing focusing lens 31, is reflected by the mirror 32, and is half. It passes through the mirror 33A, is reflected by the dichroic mirror 33, and is projected onto the light receiving surface of the CCD image sensor 35 by the condenser lens 34. Based on the received light image (alignment index image) by the CCD image sensor 35, the same manual alignment and auto alignment as before can be performed.

The focus optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10 in conjunction with the movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30. The reflection rod 67 is removable with respect to the illumination optical path.

When adjusting the focus, the reflecting surface of the reflecting rod 67 is obliquely provided in the illumination optical path. The focus light output from the LED 61 passes through the relay lens 62, is separated into two light beams by the split optotype 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is reflected by the condenser lens 66. It is once imaged on the reflecting surface of 67 and reflected. Further, the focus light passes through the relay lens 20, is reflected by the perforated mirror 21, passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef.

The fundus reflected light of the focus light is detected by the CCD image sensor 35 through the same path as the corneal reflected light of the alignment light. Based on the received light image (split index image) by the CCD image sensor 35, the same manual alignment and auto alignment as before can be performed.

The photographing optical system 30 includes diopter correction lenses 70 and 71. The diopter correction lenses 70 and 71 can be selectively inserted into the photographing optical path between the perforated mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus (+) lens for correcting high-intensity hyperopia, for example, a + 20D (diopter) convex lens. The diopter correction lens 71 is a minus (−) lens for correcting intense myopia, for example, a −20D concave lens. The diopter correction lenses 70 and 71 are attached to, for example, a turret plate. The turret plate is formed with a hole for when neither of the diopter correction lenses 70 and 71 is applied.

The dichroic mirror 46 synthesizes an optical path for fundus photography and an optical path for OCT. The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus photography. The optical path for OCT is provided with a collimator lens unit 40, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a mirror 44, and a relay lens 45 in this order from the OCT unit 100 side.

The optical path length changing unit 41 is movable in the direction of the arrow shown in FIG. 1, and changes the optical path length of the optical path for OCT. This change in the optical path length is used for correcting the optical path length according to the axial length of the eye E to be inspected, adjusting the interference state, and the like. The optical path length changing unit 41 includes, for example, a corner cube and a mechanism for moving the corner cube.

The optical scanner 42 is arranged at a position optically conjugate with the pupil of the eye E to be inspected. The optical scanner 42 changes the traveling direction of the measurement light LS passing through the optical path for OCT. As a result, the eye E to be inspected is scanned by the measurement light LS. The optical scanner 42 can deflect the measurement light LS in an arbitrary direction of the xy plane, and includes, for example, a galvano mirror that deflects the measurement light LS in the x direction and a galvano mirror that deflects the measurement light LS in the y direction.

<OCT unit 100>
As illustrated in FIG. 2, the OCT unit 100 is provided with an optical system for performing OCT of the eye E to be inspected. The configuration of this optical system is the same as that of the conventional swept source OCT. That is, this optical system divides the light from the wavelength sweep type (wavelength scanning type) light source into the measurement light and the reference light, and separates the return light of the measurement light from the eye E to be examined and the reference light via the reference optical path. It includes an interference optical system that causes interference to generate interference light and detects this interference light. The detection result (detection signal) obtained by the interference optical system is a signal showing the spectrum of the interference light, and is sent to the arithmetic control unit 200.

The light source unit 101 includes a wavelength sweep type (wavelength scanning type) light source that changes the wavelength of the emitted light at high speed, similarly to a general swept source OCT. The wavelength sweep type light source is, for example, a near infrared laser light source.

The light L0 output from the light source unit 101 is guided by the optical fiber 102 to the polarization controller 103, and its polarization state is adjusted. Further, the optical L0 is guided by the optical fiber 104 to the fiber coupler 105 and divided into the measurement optical LS and the reference optical LR.

The reference optical LR is guided by the optical fiber 110 to the collimator 111, converted into a parallel luminous flux, and guided to the corner cube 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with the optical path length of the measurement light LS. The dispersion compensating member 113 acts to match the dispersion characteristics between the reference light LR and the measurement light LS.

The corner cube 114 turns back the traveling direction of the incident reference light LR in the opposite direction. The incident and exit directions of the reference light LR with respect to the corner cube 114 are parallel to each other. The corner cube 114 is movable in the incident direction of the reference light LR, thereby changing the optical path length of the reference light LR.

In the configurations shown in FIGS. 1 and 2, the optical path length changing unit 41 for changing the length of the optical path (measurement optical path, measurement arm) of the measurement light LS and the optical path (reference optical path, reference arm) of the reference light LR Although both corner cubes 114 for changing the length are provided, only one of the optical path length changing portion 41 and the corner cube 114 may be provided. It is also possible to change the difference between the measured optical path length and the reference optical path length by using an optical member other than these.

The reference light LR that has passed through the corner cube 114 is converted from a parallel luminous flux to a focused luminous flux by the collimator 116 via the dispersion compensating member 113 and the optical path length correction member 112, and is incident on the optical fiber 117. The reference light LR incident on the optical fiber 117 is guided by the polarization controller 118 to adjust its polarization state, is guided to the attenuator 120 by the optical fiber 119 to adjust the amount of light, and is guided to the fiber coupler 122 by the optical fiber 121. Be taken.

On the other hand, the measurement optical LS generated by the fiber coupler 105 is guided by the optical fiber 127 and converted into a parallel light beam by the collimator lens unit 40, and is converted into a parallel light beam by the collimator lens unit 40, and the optical path length changing unit 41, the optical scanner 42, the OCT focusing lens 43, and the mirror 44. The light is reflected by the dichroic mirror 46 via the relay lens 45, refracted by the objective lens 22, and incident on the eye E to be inspected. The measurement light LS is scattered and reflected at various depth positions of the eye E to be inspected. The return light of the measurement light LS from the eye E to be inspected travels in the same direction as the outward path in the opposite direction, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

The fiber coupler 122 generates interference light by synthesizing (interfering with) the measurement light LS incidented through the optical fiber 128 and the reference light LR incidented via the optical fiber 121. The fiber coupler 122 generates a pair of interference light LCs by branching the interference light at a predetermined branching ratio (for example, 1: 1). The pair of interference light LCs are guided to the detector 125 through the optical fibers 123 and 124, respectively.

The detector 125 is, for example, a balanced photodiode (Balanced Photo Diode). The balanced photodiode has a pair of photodetectors that detect each pair of interference light LCs, and outputs the difference between the detection results by these. The detector 125 sends the detection result (detection signal) to the DAQ (Data Acquisition System) 130.

A clock KC is supplied to the DAQ 130 from the light source unit 101. The clock KC is generated in the light source unit 101 in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength sweep type light source. The light source unit 101 optically delays one of the two branched lights obtained by branching the light L0 of each output wavelength, and then sets the clock KC based on the result of detecting the combined light. Generate. The DATA 130 samples the detection signal input from the detector 125 based on the clock KC. The DAQ 130 sends the sampling result of the detection signal from the detector 125 to the arithmetic control unit 200.

<Calculation control unit 200>
The arithmetic control unit 200 controls each part of the fundus camera unit 2, the display device 3, and the OCT unit 100. In addition, the arithmetic control unit 200 executes various arithmetic processes. For example, the arithmetic control unit 200 performs signal processing such as Fourier transform on the spectrum distribution based on the detection result obtained by the detector 125 for each series of wavelength scans (for each A line), thereby performing signal processing in each A line. Form a reflection intensity profile. Further, the arithmetic control unit 200 forms image data by imaging the reflection intensity profile of each A line. The arithmetic processing for that purpose is the same as that of the conventional swept source OCT.

The arithmetic control unit 200 includes, for example, a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, and the like. Various computer programs are stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may include an operation device, an input device, a display device, and the like.

<Control system>
FIG. 3 shows a configuration example of the control system of the ophthalmic apparatus 1.

<Control unit 210>
The control unit 210 controls each unit of the ophthalmic apparatus 1. The control unit 210 includes a processor. The control unit 210 is provided with a main control unit 211, a storage unit 212, a fixation setting unit 213, and a position information generation unit 214.

<Main control unit 211>
The main control unit 211 performs various controls. For example, the main control unit 211 includes a photographing focusing lens 31, CCD (image sensor) 35 and 38, LCD 39, an optical path length changing unit 41, an optical scanner 42, an OCT focusing lens 43, a focus optical system 60, a reflecting rod 67, and the like. To control. Further, the main control unit 211 controls the light source unit 101, the reference drive unit 114A, the detector 125, the DAQ 130, and the like. The reference drive unit 114A moves the corner cube 114 provided in the reference optical path. Thereby, the length of the reference optical path is changed.

The ophthalmic device 1 includes a moving mechanism 150. The moving mechanism 150 moves, for example, the fundus camera unit 2 (or at least a part of the optical system housed therein). The moving mechanism 150 may be able to move the OCT unit 100 (or at least a part of the optical system housed therein). The moving mechanism 150 includes one or more actuators 151. The actuator 151 includes, for example, a pulse motor or the like controlled by the main control unit 211, and generates a driving force for moving the fundus camera unit 2 or the like. The driving force generated by the pulse motor 151 is transmitted by a mechanism (not shown) to move the fundus camera unit 2 and the like. As a result, the fundus camera unit 2 and the like are moved three-dimensionally. The moving mechanism 150 is, for example, an x-moving mechanism including a first actuator and a mechanism for converting a first driving force generated by the first actuator into movement in the x-direction, a second actuator and a second driving force generated by the second actuator. Includes a y-movement mechanism with a mechanism for converting ..

<Memory unit 212>
The storage unit 212 stores various types of data. The data stored in the storage unit 212 includes, for example, image data of an OCT image, image data of a fundus image, eye information to be inspected, and the like. The eye test information includes subject information such as patient ID and name, left eye / right eye identification information, electronic medical record information, and the like.

Further, the storage unit 212 may store in advance information (fixation information) for controlling fixation. In one example of fixation information, the part of the eye and the aspect of the fixation target are associated with each other. This fixation information associates the display position of the fixation target on the LCD 39 with each of the two or more parts of the eye. Alternatively, this fixation information associates the shape of the fixation target displayed on the LCD 39 with each of the two or more parts of the eye.

The aspect of the fixation target recorded in the fixation information may include an aspect of change of the fixation target. In the present embodiment, at least one of the projection position and the shape of the fixation light beam with respect to the eye E to be inspected is changed according to the movement of the fundus camera unit 2 and the like. In order to realize such control, the fixation information associates the position of the fundus camera unit 2 and the like with the projection position and / or shape of the fixation light flux. The position of the fundus camera unit 2 and the like is detected by an arbitrary method. This position detection is performed using, for example, an encoder provided in the moving mechanism 150, the fundus camera unit 2, or the like. Alternatively, this position detection may be performed with reference to the control history of the moving mechanism 150 by the main control unit 211. Alternatively, this position detection may be performed by a method using two or more anterior segment cameras disclosed in Japanese Patent Application Laid-Open No. 2013-248376.

An example of the screen configuration of the LCD 39 is shown in FIG. The LCD 39 of this example is a dot matrix LCD, and 51 pixels (x direction) × 51 pixels (y direction) are arranged on the screen 39a. Coordinates 0 to 50 are given to the array in the x direction (horizontal direction) in order from left to right, and coordinates 0 to 50 in order from bottom to top in the array in the y direction (vertical direction). Is given.

The characters attached to some pixels of the screen 39a indicate the positions of the fixation targets (bright spots) corresponding to the parts of the eye. When the eye to be inspected is the right eye, the pixel "M" of (x, y) = (25, 25) indicates the fixation target corresponding to the macula, and the pixel "C" of (x, y) = (20, 26). Indicates a fixation target corresponding to the center of the fundus, and the pixel "W" of (x, y) = (17,26) indicates a fixation target corresponding to a wide scan, and (x, y) = (10, Pixel "C" in 26) indicates a fixation target corresponding to the optic nerve head. When the eye to be inspected is the left eye, the pixel "M" of (x, y) = (25, 25) indicates a fixation target corresponding to the macula, and the pixel of (x, y) = (30, 26). “C” indicates the fixation target corresponding to the center of the fundus, and the pixel “W” of (x, y) = (33, 26) indicates the fixation target corresponding to the wide scan, and (x, y) = ( Pixels "C" in 40 and 26) indicate a fixation target corresponding to the optic disc. Further, the eight pixels "2" to "9" arranged in a circular shape indicate the fixation targets corresponding to the eight positions in the peripheral portion of the fundus. The optical axis (objective optical axis) of the objective lens 22 is arranged at the lower left corner of the pixel "M".

An example of fixation information is shown in FIG. The fixation information 212a associates the initial position and the final position of the fixation target with the eye region (fixation position) to be inspected. Pixels "M" are associated with both the initial position and the final position of the site "macula". The initial position "M" and the final position "C" are associated with the site "center of the fundus". The initial position "M" and the final position "W" are associated with the portion "wide". The site "optic disc" is associated with an initial position "M" and a final position "D".

In this example, the position of the fixation target is unchanged for the site "macula", but the fixation target is moved for the sites "center of the fundus", "wide" and "optic disc". Similarly, the pixels "M" can be set as the initial positions for the pixels "2" to "9" corresponding to the peripheral portion of the fundus. The position of the fixation target may be unchanged for a portion whose final position is relatively close to the objective optical axis, such as "center of fundus" or "wide".

The initial positions of the sites "center of the fundus", "wide", "optic disc" and the periphery of the fundus may be other than the pixel "M". For example, the initial position may be set to an arbitrary position on the macula "M" side of the final position.

Another example of fixation information is shown in FIG. The fixation information 212b associates the initial form and the final form of the fixation target with the part of the eye (fixation position) to be inspected. Pixels "M" are associated with the site "macula" in both the initial form and the final form. The initial form "Line MC" and the final form "C" are associated with the site "center of the fundus". “Line MC” indicates a straight line (line segment) connecting the pixel “M” and the pixel “C”. The initial form "Line MW" and the final form "W" are associated with the portion "wide". “Line MW” indicates a straight line connecting the pixel “M” and the pixel “W”. The site "optic disc" is associated with an initial form "Line MD" and a final form "D". “Line MD” indicates a straight line (line segment) connecting the pixel “M” and the pixel “D”.

In this example, the morphology of the fixation target is unchanged for the site "macula", but the morphology of the fixation target is changed for the sites "center of the fundus", "wide" and "optic disc". Specifically, for these parts, the shape of the fixation target changes from the bright line connecting the initial position and the final position shown in FIG. 5 to the bright point indicating the final position. The same may apply to the pixels "2" to "9" corresponding to the peripheral portion of the fundus. The form of the fixation target may be unchanged for a portion whose final position is relatively close to the objective optical axis, such as "center of fundus" or "wide".

The fixation information is not limited to these. For example, the form of the fixation target is not limited to a straight line or a point, and may be an arbitrary one-dimensional shape or an arbitrary two-dimensional shape. It is also possible to display information different from the fixation target on the LCD 39. For example, an image of an arrow pointing to the final position of the fixation target is displayed using pixel "M" and pixels around it.

<Focus setting unit 213>
In the present embodiment, the part of the eye (fixation position) to be examined is specified. The designation of the site is performed manually, for example, using the user interface 240. Alternatively, the control unit 210 may specify the site based on the selection result of the inspection mode or the analysis mode. Further, in follow-up observation, preoperative and postoperative observation, etc., the control unit 210 can acquire the site designated in the past examination from the electronic medical record information or the like and specify it again.

The fixation setting unit 213 sets the initial form and the final form of the fixation target (fixation light flux) based on the eye portion designated in this way. This process is performed with reference to the fixation information (for example, fixation information 212a or 212b) stored in the storage unit 212. For example, when the optic nerve head is designated as the eye region, the fixation setting unit 213 acquires the initial position "M" and the final position "D" associated with the "optic nerve head" in the fixation information 212a. .. These are set as information for controlling the fixation target.

The fixation setting unit 213 may be configured to set further information for controlling the fixation target. For example, it is possible to set information indicating the timing of changing the fixation target. When the fixation information 212a shown in FIG. 5 is applied, the fixation setting unit 213 sets, for example, the movement timing of each step when the fixation target is gradually moved from the initial position to the final position for each pixel. .. As a specific example, the distance (distance in the z direction) between the position (last retracted position) of the fundus camera unit 2 or the like where the distance from the eye E to be examined is the longest and the position corresponding to the working distance (working distance) is set. , By dividing by the number of pixels between the initial position and the final position, it is possible to associate a plurality of positions between the last retracted position and the working distance position with a plurality of pixels between the initial position and the final position. Can be done.

Similarly, when the fixation information 212b shown in FIG. 6 is applied, the timing of shortening the length of the emission line is set to a plurality of positions in the z direction (for example, a plurality of positions between the last retracted position and the working distance position). It is possible to associate it with the position). Further, it is possible to set the timing of displaying the arrow image indicating the final position of the fixation target and the timing of hiding it in association with a plurality of positions in the z direction. For example, the LCD 39 is displayed so that the arrow image is displayed when the fundus camera unit 2 or the like is located within a predetermined distance from the last retracted position, and the arrow image is not displayed when the fundus camera unit 2 or the like is located outside this range. Can be controlled.

<Location information generator 214>
The position information generation unit 214 generates position information indicating the position of the fundus camera unit 2 and the like.
When the moving mechanism 150 or the fundus camera unit 2 or the like is provided with an encoder, the position information generation unit 214 can obtain the position of the fundus camera unit 2 or the like based on the signal output from the encoder. Further, when the main control unit 211 executes the control of the movement mechanism 150, the position information generation unit 214 can obtain the position of the fundus camera unit 2 and the like based on the control history of the movement mechanism 150 by the main control unit 211. When two or more front-eye cameras are provided, the position information generation unit 214 and the fundus camera unit 2 and the like and the eye to be inspected by executing the arithmetic processing disclosed in Japanese Patent Application Laid-Open No. 2013-248376. The relative position with E can be obtained.

In this way, the position information generation unit 214 may generate position information of the fundus camera unit 2 or the like represented by a predetermined coordinate system (for example, the xyz coordinate system representing the movement state by the movement mechanism 150). Alternatively, position information indicating the relative position between the fundus camera unit 2 and the like and the eye E to be inspected may be generated.

<Image forming unit 220>
The image forming unit 220 forms the image data of the cross-sectional image of the fundus Ef based on the sampling result of the detection signal input from the DAQ 130. This processing includes signal processing such as noise removal (noise reduction), filter processing, and FFT (Fast Fourier Transform), as in the conventional swept source OCT. The image data formed by the image forming unit 220 is a group of image data (a group of image data) formed by imaging reflection intensity profiles in a plurality of A lines (lines in the z direction) arranged along the scan line. It is a data set including A scan image data).

The image forming unit 220 includes, for example, at least one of a processor and a dedicated circuit board. In this specification, "image data" and "image" based on the "image data" may be equated with each other. In addition, the part of the eye E to be inspected and the image showing it may be equated.

<Data processing unit 230>
The data processing unit 230 performs image processing and analysis processing on the image formed by the image forming unit 220. For example, the data processing unit 230 executes correction processing such as image brightness correction and dispersion correction. Further, the data processing unit 230 performs image processing and analysis processing on the images (fundus image, anterior ocular segment image, etc.) obtained by the fundus camera unit 2. The data processing unit 230 includes, for example, at least one of a processor and a dedicated circuit board.

<User interface 240>
The user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes a display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device such as a touch panel in which a display function and an operation function are integrated. It is also possible to build embodiments that do not include at least a portion of the user interface 240. For example, the display device may be an external device connected to an ophthalmic device.

<motion>
The operation of the ophthalmic apparatus 1 will be described. An example of the operation is shown in FIG.

(S1: Specify the imaging site)
First, the part of the eye E to be inspected to be the target of OCT or fundus photography is designated. As described above, the user (inspector) or the control unit 210 specifies the imaging site.

(S2: Set the initial form and final form of the fixation target)
The fixation setting unit 213 sets the initial form and the final form of the fixation target (fixation light flux) based on the part of the eye designated in step S1. This process is performed with reference to the fixation information stored in the storage unit 212. For example, when the imaging site "optic disc" is designated in step S1, the fixation setting unit 213 has an initial position "M" and a final position "D" corresponding to the "optic disc" in the fixation information 212a shown in FIG. To get.

(S3: Display the initial form of the fixation target)
The main control unit 211 causes the LCD 39 to display the fixation target in the initial form set in step S2. For example, when the initial position "M" is set in step S2, the main control unit 211 has the pixel "" located at (x, y) = (25, 25) among the plurality of pixels arranged on the screen 39a of the LCD 39. Only "M" is turned on. As mentioned above, the pixel "M" is arranged on the objective optical axis (more specifically, the pixel "M" is one of the four pixels closest to the objective optical axis).

(S4: Retreat the optical system and observe the anterior segment of the eye)
The user or the main control unit 211 retracts the optical system (fundus camera unit 2 or the like) in order to observe the anterior segment of the eye E to be inspected by operating the moving mechanism 150, and arranges the optical system (fundus camera unit 2 or the like) at the rearmost retracted position, for example. The anterior segment observation is performed by the main control unit 211 displaying a moving image of the observation image (moving image) of the anterior segment obtained by using the above-mentioned observation illumination light (near infrared light) on the display unit 241. Alternatively, it may be a moving image of the anterior segment obtained by at least one of the anterior segment cameras 5A and 5B. The anterior segment cameras 5A and 5B will be described later.

FIG. 8A shows the presentation state of the fixation target when the optical system is retracted. At this stage, the pixel "M" is turned as the initial form of the fixation target (initial fixation target T _S). Since the initial fixation target T _S is disposed on the objective optical axis 22a, a fixation light beam output from the pixel "M" is projected onto the fundus oculi Ef of the eye E through the objective lens 22. Thus, the subject can visually recognize the initial fixation target T _S.

Fixation target T _E is a pixel corresponding to "the optic papilla", "D", used as the final fixation target in this example. The initial fixation target T _S is first displayed in this example, the conventional ophthalmologic apparatus pixel "D" is displayed from beginning to end. At the stage of step S4, the involuntary luminous flux DP output from the pixel “D” cannot pass through the objective lens 22, so that it is not projected onto the fundus Ef. Therefore, in the case of a conventional ophthalmic device, the subject cannot visually recognize the fixation target at this stage.

Reference numeral 4 in FIG. 8A represents a housing in which the optical system is housed. For example, the fundus camera unit 2 and the OCT unit 100 are housed in the housing 4. Two anterior segment cameras 5A and 5B disclosed in Japanese Patent Application Laid-Open No. 2013-248376 are provided on the surface (front surface) of the housing 4 on the side of the eye to be inspected E. The position information generation unit 214 obtains the three-dimensional position of the eye E to be inspected by analyzing two anterior segment images acquired substantially simultaneously from different directions by the anterior segment cameras 5A and 5B. This three-dimensional position is the relative position of the eye E to be inspected with respect to the anterior segment cameras 5A and 5B (that is, the optical system housed in the fundus camera unit 2 and the like). Further, the analysis of the two anterior segment images may be the same as the analysis disclosed in Japanese Patent Application Laid-Open No. 2013-248376.

(S5: Align the center of the pupil with the center of the anterior segment image)
The user or the main control unit 211 analyzes the observation image of the anterior eye portion so that the pupil center of the eye E to be inspected is arranged in the frame center (or within a predetermined range including the frame center) of the observation image. 4 is moved in the x direction and the y direction. As a result, the x-position and the y-position of the optical system are adjusted so that the objective optical axis 22a is arranged at the center of the pupil of the eye E to be inspected.

(S6: Start advancing the optical system)
The user or the main control unit 211 starts advancing the housing 4 by operating the moving mechanism 150. As a result, the housing 4 is moved in the + z direction from, for example, the last retracted position toward the eye E to be inspected.

The two front eye cameras 5A and 5B shoot moving images at predetermined time intervals (shooting rates), and the position information generation unit 214 sequentially calculates the relative position between the eye E to be inspected and the optical system in real time.

(S7: Start morphological change of fixation target)
The main control unit 211 changes the form of the fixation target based on the position information sequentially acquired by the position information generation unit 214. In this example, the main control unit 211 changes the position of the fixation target displayed on the LCD 39 according to the change in the relative position between the eye E to be inspected and the optical system. For example, the main control unit 211 moves the display position of the fixation target by a predetermined unit distance in response to a change in the distance in the z direction between the eye E to be inspected and the optical system by a predetermined unit amount. .. As a specific example, the main control unit 211 sets the display position of the fixation target to the initial fixation target T each time the distance between the eye E to be inspected and the optical system in the z direction decreases (or increases) by a unit amount. moving from _S side by one pixel in the final fixation target T _E side. Here, the predetermined unit amount and the predetermined unit distance are recorded in advance in, for example, fixation information.

The state in which the fixation target is displayed between the initial fixation target T _S and a final fixation target T _E shown in FIG. 8B. At this stage, the housing 4 is located between the position corresponding to the rearmost position and the working distance (working distance position), between the LCD39 initial fixation target T _S and a final fixation target T _E intermediate fixation target T _H is displayed. At any time during the movement of the housing 4, the display position of the intermediate fixation target T _H is the fixation light beam HP, so as to pass through the objective lens 22 (i.e. the eye E is visually recognized an intermediate fixation target T _H To be controlled). This control is performed based on, for example, fixation information. In the state shown in FIG. 8B, the fixed-point luminous flux DP output from the pixel “D” still cannot pass through the objective lens 22. Therefore, in the case of a conventional ophthalmic device, the subject cannot visually recognize the fixation target even at this stage.

(S8: Did you reach the WD position (neighborhood)?)
The advance of the optical system and the morphological change of the fixation target are executed until it is determined that the housing 4 has reached (near) the working distance position. Whether or not the housing 4 has reached (near) the working distance position is determined based on the position information obtained in real time by the position information generation unit 214.

The "neighborhood" of the working distance is set in advance at least in a range in which the involuntary luminous flux DP output from the pixel "D" passes through the objective lens 22. Further, in response to the case 4 being advanced to a predetermined position, the main control unit 211 is a front lens (not shown) for switching the focus of the optical system from the focus for observing the anterior segment of the eye to the focus for observing the fundus. ) Is inserted. Before the housing 4 reaches the working distance position, the displayed observation image is switched from the anterior segment observation image to the fundus observation image.

(S9: The final form of the fixation target is displayed)
When the housing 4 has reached the working distance position (near), the main control unit 211 displays the final fixation target T _E by illuminating the pixel "D". The final fixation target T _E is the position of the fixation target corresponding to the optic papilla is an imaging region designated in step S1 (i.e. the target site of OCT and fundus photography).

A state in which final fixation target T _E is displayed shown in FIG. 8C. At this stage, the housing 4 is placed in the working distance position, the final fixation target T _E is displayed on the LCD 39. As described above, in this example, the subject can always visually recognize the fixation target while moving the housing 4 from the last retracted position to the working distance position. Gradually Specifically, the subject is initially viewing the initial fixation target T _S that is displayed in the center of the LCD 39 (pixel "M"), the intermediate stage toward the final fixation target T _E viewing the moving intermediate fixation target T _H. Thereby, the fixation position of the eye E is directed to the final fixation target T _E corresponding to the imaging region.

It should be noted that the housing 4 may be moved backward after starting to move forward. In that case, the main control unit 211 sets the display position of the fixation target to the initial fixation target T according to the distance (the amount of increase in the relative distance between the eye to be inspected E and the optical system) in which the housing 4 is moved backward. It can be moved to the _{S side.}

(S10: Fine-tune the alignment)
The user or the ophthalmic apparatus 1 aligns the optical system with respect to the eye E to be inspected, for example, based on the alignment index. As a result, the result of the alignment performed in steps S6 to S9 is fine-tuned. It is also possible to fine-tune the alignment based on the pair of anterior segment observation images obtained by the two anterior segment cameras 5A and 5B.

(S11: Adjust the shooting conditions)
The user or the ophthalmic apparatus 1 adjusts various imaging conditions such as fine adjustment of the scanning position, fine adjustment of the measurement arm length and the reference arm length, fine adjustment of the presentation position of the fixation target, focus adjustment, and insertion of the small pupil diaphragm. conduct.

(S12: Photograph the fundus)
The ophthalmologic apparatus 1 executes OCT and imaging of the fundus Ef. The acquired data is stored in the storage unit 212 or the external storage. In addition, the ophthalmic apparatus 1 or another apparatus executes imaging processing and analysis processing based on the acquired data.

<Action / effect>
The operation and effect of the ophthalmic apparatus according to the embodiment will be described.

The ophthalmic apparatus of the embodiment includes an optical system, a moving mechanism, and a control unit. The optical system includes an objective lens, an irradiation optical system that irradiates the eye to be inspected with light through the objective lens, and a fixation system that projects a fixation light beam onto the eye to be inspected through the objective lens. In the above embodiment, the objective lens 22 corresponds to the objective lens, the illumination optical system 10 and the measuring arm correspond to the irradiation optical system, and the optical path from the LCD 39 to the objective lens 22 corresponds to the fixation system.

The moving mechanism operates to move at least a part of the optical system including the objective lens. In the above embodiment, the moving mechanism 150 corresponds to the moving mechanism.

The control unit changes at least one of the projection position and the shape of the fixation light flux by controlling the fixation system in response to the movement of at least a part of the optical system by the movement mechanism. In the above embodiment, the control unit 210 corresponds to the control unit.

According to such an embodiment, when the optical system is moved in a state where the fixation target is presented in alignment or the like, the projection position and shape of the fixation light flux can be changed according to the movement of the optical system. .. Therefore, it is possible to improve the visibility of the fixation target so that the subject can continuously see the fixation target. As a result, alignment and the like can be performed properly. In addition, there is no inconvenience that the eye to be inspected suddenly rotates when the fixation target enters the field of view and flare occurs in the observed image.

The ophthalmic apparatus of the embodiment may include a designated portion for designating a portion of the eye to be inspected to be irradiated with light by the irradiation optical system. In this case, the control unit can switch at least one mode of change in the projection position and shape of the fixation light flux according to the portion designated by the designated unit. The designation of the part is performed manually or automatically.

In the above embodiment, the user interface 240 and the control unit 210 correspond to the designated unit. Further, the control unit 210 of the above embodiment refers to the fixation information 212a shown in FIG. 5, and refers to the first projection position (initial) of the fixation light flux according to a designated site (macula, optic disc, etc.). The position) and the last projection position (final position) can be switched. Here, the fixation information 212a can include information indicating one or more projection positions arranged between the initial position and the final position and the timing of changing the projection position. In this case, the control unit 210 executes control for sequentially projecting the fixation light flux to three or more projection positions according to the fixation information 212a, and control for changing the projection position at the timing according to the fixation information 212a. ..

As another example, the control unit 210 refers to the fixation information 212b shown in FIG. 6, and refers to the initial shape (initial form) of the fixation light flux according to a designated site (macula, optic disc, etc.). And the final form (final form) can be switched. Here, it is possible to include one or more intermediate forms applied between the initial form and the final form, and information indicating the timing of changing the form in the fixation information 212b. In this case, the control unit 210 controls to change the form of the fixation light flux into three or more forms according to the fixation information 212b, and a control to change the form of the fixation light flux at the timing according to the fixation information 212b. Execute.

According to such a configuration, it is possible to change the projection position and shape of the fixation light flux in a manner corresponding to a designated portion (photographed portion or the like). Therefore, control for allowing the subject to continuously see the fixation target can be executed according to the designated portion. As a result, it is possible to improve visibility regardless of the designated portion.

In the embodiment, the control unit may include a setting unit that sets an initial mode and a final mode of the fixation light flux based on a portion designated by the designated unit. In this case, the control unit can change at least one of the projection position and the shape of the fixation light flux from the initial mode to the final mode.

In the above embodiment, the fixation setting unit 213 corresponds to the setting unit. Further, examples of the initial mode include the initial position of FIG. 5 and the initial form of FIG. 6, and examples of the final mode include the final position of FIG. 5 and the final form of FIG.

According to such a configuration, it is possible to automatically set the mode of change of the fixation target due to the movement of the optical system according to the designated portion. Therefore, the operability and convenience of the ophthalmic apparatus are improved.

The setting unit sets the initial mode and so that the distance between the fixation beam of the initial mode and the optical axis of the objective lens is shorter than the distance between the fixation beam of the final mode and the optical axis of the objective lens. It may be configured to set the final aspect.

In the above embodiment, for example, when the designated site is the optic nerve head, the fixation setting unit 213 sets the pixel "M" on the objective optical axis 22a as the initial position, and at a position away from the objective optical axis 22a. The pixel "D" can be set as the final position. Similarly, when the designated site is the optic nerve head, the fixation setting unit 213 sets a straight line connecting the pixel "M" on the objective optical axis 22a and the pixel "D" at a position away from it as the initial form. Moreover, the pixel "D" at a position away from the objective optical axis 22a can be set as the final position.

According to such a configuration, it is possible to guide the fixation to a designated portion while starting the change of the aspect (projection position, shape) of the fixation target from the vicinity of the objective optical axis having high visibility.

In the embodiment, the control unit is configured to change at least one of the projection position and shape of the fixation light flux from the initial mode to the final mode in response to the shortening of the distance between the objective lens and the eye to be inspected by the moving mechanism. May be done.

In the above embodiment, for example, when the designated site is the optic nerve head, the control unit 210 changes the display position of the fixation target from the pixel "M" to the pixel "C" as the housing 4 approaches the eye E to be inspected. Can be made to.

Thus, the embodiment may be configured as follows: the optometry system includes a luminous flux output unit (LCD39) that outputs a luminous flux; the setting unit is the initial output of the luminous flux by the luminous flux output unit. The position and the final output position are set; the control unit changes the output position of the fixed-point luminous flux by the luminous flux output unit from the initial output position to the final output position according to the shortening of the distance between the objective lens and the eye to be inspected. Let me.

Further, in the above embodiment, when the designated site is the optic nerve head, the control unit 210 starts with the pixel "C" from the emission line connecting the pixel "M" and the pixel "C" as the housing 4 approaches the eye E to be inspected. The fixation target can be changed up to the bright spot in.

Thus, the embodiment may be configured as follows: the optometry system includes a luminous flux output unit (LCD39) that outputs a luminous flux; the setting unit is the initial output of the luminous flux by the luminous flux output unit. The shape and the final output shape are set; the control unit changes the output shape of the involuntary luminous flux by the luminous flux output unit from the initial output shape to the final output shape according to the shortening of the distance between the objective lens and the eye to be inspected. Let me.

The ophthalmic apparatus of the embodiment may include an operation unit (for example, an operation unit 242). Further, the moving mechanism may be configured to move at least a portion of the optical system in response to an operation performed using the operating unit. That is, the ophthalmic apparatus of the embodiment may be configured to move the optical system by manual operation. As a result, it is possible to improve the visibility of the fixation target in manual alignment.

In embodiments, the moving mechanism may include an actuator controlled by a control unit (eg, actuator 151). Further, the control unit may be configured to coordinately control the actuator and the fixation system. As a result, the movement of the optical system can be linked with the movement and deformation of the fixation target, and the visibility of the fixation target in auto-alignment can be improved.

The ophthalmic apparatus of the embodiment may include a positioning portion that locates at least a part of the optical system that is moved by the moving mechanism. In the above embodiment, the position specifying unit includes the position information generating unit 214, and the position of the optical system is specified by using, for example, an encoder provided in the moving mechanism 150, the fundus camera unit 2, or the like, or main control. It is performed with reference to the control history of the moving mechanism 150 by the unit 211, or is performed using two or more anterior segment cameras. Further, the control unit controls the fixation system based on the position of the optical system specified by the position specifying unit.

According to this configuration, it is possible to suitably change the projection position and shape of the solid-view light flux while monitoring the position of the optical system.

The embodiments described above are merely examples of the present invention. A person who intends to carry out the present invention can arbitrarily make modifications (omission, substitution, addition, etc.) within the scope of the gist of the present invention.

1 Ophthalmic device 10 Illumination optical system 22 Objective lens 39 LCD
100 OCT unit 150 Moving mechanism 210 Control unit

Claims (5)

An optical system including an objective lens, an irradiation optical system that irradiates one eye to be inspected with light through the objective lens, and a fixation system that projects a fixation light beam onto the one eye to be inspected through the objective lens. When,
A moving mechanism capable of three-dimensionally moving at least a part of the optical system including the objective lens,
An ophthalmic apparatus including a control unit that controls the fixation system for changing the shape of the fixation light flux while controlling the movement mechanism for alignment of the optical system with respect to the one eye to be inspected. A designated portion for designating the site of the one eye to be inspected to be irradiated with light by the irradiation optical system is provided.
The ophthalmic apparatus according to claim 1, wherein the control unit switches the mode of changing the shape of the fixation light flux according to the portion designated by the designation unit. Equipped with an operation unit
The ophthalmic apparatus according to claim 1 or 2, wherein the moving mechanism moves at least a part of the optical system in response to an operation performed by using the operating unit. The moving mechanism includes an actuator controlled by the control unit.
The ophthalmic apparatus according to claim 1 or 2, wherein the control unit links and controls the actuator and the fixation system. A position specifying unit for specifying the position of at least a part of the optical system moved by the moving mechanism is provided.
The ophthalmic apparatus according to any one of claims 1 to 4, wherein the control unit executes control of the fixation system based on the position specified by the position specifying unit.

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