Ophthalmic device and ophthalmic system

Abstract

SOLUTION: In scanning an eye to be examined, a computer determines spiral scan parameters for executing a spiral scan of the eye to be examined, generates a scanner driving signal in the spiral scan parameters, and controls a scanner on the basis of the scanner driving signal. The computer executes conversion for aligning the spirally aligned data into a grid shape.EFFECT: Use of a spiral scan allows imaging with a high degree of precision to be achieved stably since there is only a slight speed difference in the change of a driving angle of a vertical axis and a horizontal axis.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to an ophthalmic device and an ophthalmic system.

Background Art

[0002] U.S. Patent Application Publication No. 2017 / 0065169 (Patent Document 1) discloses a method for scanning an eye to be examined and performing tomographic imaging.

[0003] A scanning method for performing cross-sectional imaging of a wide area of an eye to be examined is desired.

Summary of the Invention

[0004] In an aspect of the present disclosure, when scanning an eye to be examined, a computer determines spiral scan parameters for spirally scanning the eye to be examined, generates a scanner drive signal in the spiral scan parameters, and controls a scanner based on the scanner drive signal.

Brief Description of the Drawings

[0005]

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Embodiments for Carrying Out the Invention

[0006] Hereinafter, examples of embodiments of the disclosed technology will be described with reference to the drawings. In each drawing, the same or equivalent components and parts are given the same reference numerals. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios.

[0007] [Overview of the Ophthalmic System According to Embodiments of the Present Disclosure] First, an overview of the embodiments of the present disclosure will be described. FIG. 1 is a diagram showing the difference in the scanning method between raster scanning and spiral scanning according to the scanning method of the present embodiment when scanning a wide area from the central part to the peripheral part of the fundus. In the raster scanning on the left side of FIG. 1, one of the vertical axis and the horizontal axis is moved at high speed, and the other is moved at low speed. The axis moved at high speed is the high-speed axis, and the other is the low-speed axis. In FIG. 1, the vertical axis is the high-speed axis, and the horizontal axis is the low-speed axis. The spiral scan on the right side of FIG. 1 is such that the scan position moves in a spiral shape from the center to the periphery.

[0008] As shown in FIG. 2, in raster scanning, while the high-speed axis operates for a plurality (many) of cycles, the low-speed axis operates for one cycle. Therefore, the change in the driving angle is gentle (the angular velocity is small). Thus, in raster scanning, the speed difference in the change of the driving angles of the vertical axis and the horizontal axis is significantly different. For this reason, in a state where the eye to be examined is fixated in the optical axis direction of the objective optical system, in photographing a wide area including not only the central part but also the peripheral part of the eye to be examined, the speed difference in the change of the driving angles of the vertical axis and the horizontal axis becomes prominent, making it difficult to achieve accurate photographing and lacking stability. Also, in order to scan a wide area including the central part and the peripheral part of the eye to be examined in a state where the eye to be examined is fixated in the optical axis direction of the objective optical system, optical adjustments such as focusing must be followed in accordance with the periodic operation of the high-speed axis. This is because the fundus to be photographed is the inner surface of the eyeball, and the optical path length from the pupil to the retina is different between the central part and the peripheral part of the fundus. The change in the optical path length due to the scan position becomes particularly prominent when performing OCT imaging.

[0009] On the other hand, in the spiral scan of the present disclosure, as shown in FIG. 2, since the change in the driving angles of the vertical axis and the horizontal axis is defined based on a sine wave, the change between the vertical axis and the horizontal axis is smaller than that in raster scanning. For this reason, even when photographing a wide area including the central part and the peripheral part of the eye to be examined in a single scan, stable and accurate photographing can be achieved.

[0010] Also, in raster scanning and spiral scanning, the focus adjustment, which is one of the optical adjustments, is also different. The focus adjustment will be described with reference to FIGS. 3 and 4.

[0011] FIG. 3 shows a cross-sectional view of the eye to be examined and a contour diagram of the retinal surface at the pupil-to-retina distance. A contour diagram is a diagram in which a contour map is represented by the shade of color instead of lines. As shown in FIG. 3, the distance from the pupil to the retinal surface changes according to the angular field of the incident light beam. Note that the distance from the pupil to the retinal surface can also be rephrased as the distance between the central position of the retina and the position where the light beam hits the retina. The closer to the posterior pole of the fundus of the eye to be examined, the longer the distance from the incident light beam to the retinal surface.

[0012] FIG. 4 is a schematic diagram of focus adjustment in raster scan and spiral scan. As shown in FIG. 4, in raster scan, during one cycle of the scan on the fast axis side, the distance from the pupil to the retinal surface also changes in one cycle. Therefore, it is necessary to perform focus adjustment so as to follow the change in the distance from the pupil to the retinal surface. That is, it is necessary to perform the focus adjustment cycle at high speed in accordance with one cycle of the scan on the fast axis side of the raster scan. Thus, a lens drive mechanism or the like for performing focus adjustment needs to move at high speed.

[0013] On the other hand, in the spiral scan of the present disclosure, during the period from the start to the end of imaging, the distance from the pupil to the retinal surface only changes by one cycle (FIG. 4). Therefore, it is not necessary to perform focus adjustment at high speed. Also, in spiral scan, the focus gets closer as going to the outside, or the focus gets farther as going to the inside. For this reason, the amount of change in focus adjustment is also small, and it can be changed by a certain amount at a time. That is, the load on a lens drive mechanism or the like for performing focus adjustment can also be suppressed. When the imaging area is narrow, such as only in the central part of the fundus, the required amount of focus adjustment is small (the adjustment range becomes small), so there may be no influence on the imaging quality even without performing focus adjustment. However, when imaging including the peripheral part or the equatorial part of the fundus is performed, a large amount of focus adjustment is required as a whole (the adjustment range becomes large), so the technique of the spiral scan of the present disclosure becomes more effective.

[0014] [Embodiments of the Present Disclosure] Referring to FIG. 5, the configuration of the ophthalmic system 100 according to an embodiment of the present disclosure will be described. FIG. 5 is a block diagram showing the configuration of the ophthalmic system 100 according to the present embodiment. As shown in FIG. 5, the ophthalmic system 100 includes an ophthalmic device 110 that executes the scanning method of the present disclosure, an axial length measuring device 120, a network 130, a management server device (hereinafter referred to as "management server") 140, and an image display device (hereinafter referred to as "image viewer") 150.

[0015] The ophthalmic device 110, the axial length measuring device 120, the management server 140, and the image viewer 150 are interconnected via the network 130. The network 130 is an arbitrary network such as a LAN, a WAN, the Internet, or a wide area Ethernet network. For example, when the ophthalmic system 100 is constructed in a single hospital, a LAN can be adopted for the network 130.

[0016] The axial length measuring device 120 measures the axial length, which is the length of the eye in the axial direction of the eye to be examined 12, and transmits the measured axial length to the management server 140.

[0017] Next, the configuration of the ophthalmic device 110 will be described with reference to FIGS. 6 and 7. FIG. 6 is a block diagram showing the hardware configuration of the ophthalmic device 110 according to the present embodiment. As shown in FIG. 6, the ophthalmic device 110 includes a photographing device 14 and a control device 16. When the ophthalmic device 110 is installed on a horizontal plane, the horizontal direction is defined as the "X direction", the vertical direction with respect to the horizontal plane is defined as the "Y direction", and the direction connecting the center of the pupil of the anterior eye part of the eye to be examined 12 and the center of the eyeball is defined as the "Z direction". Therefore, the X direction, the Y direction, and the Z direction are perpendicular to each other.

[0018] The control device 16 includes a computer having a CPU (Central Processing Unit), a RAM (Random Access Memory) 16B, a ROM (Read-Only Memory) 16C, an input / output (I / O) 16D, an input / display device 16E, and a communication interface (I / F) 16F. Each component of the control device 16 is connected to be communicable with each other via a bus.

[0019] The CPU 16A is a central arithmetic processing unit that executes various programs and controls each part. That is, the CPU 16A reads a program from the ROM 16C and executes the program using the RAM 16B as a work area. The CPU 16A performs control of each component and various arithmetic processes according to the program stored in the ROM 16C. In the present embodiment, a scan program for executing a scan process is stored in the ROM 16C.

[0020] The RAM 16B temporarily stores a program or data as a work area. The ROM 16C stores various programs and various data. Note that the control device 16 may further be configured to include a storage configured by a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). In this case, the storage stores various programs including an operating system and various data.

[0021] The input / display device 16E is connected to the CPU 16A via the I / O port 16D. The input / display device 16E has a graphical user interface (GUI) that displays an image of the eye to be examined 12 and receives various instructions from the user. As the GUI, a touch panel or a display can be adopted. Further, the control device 16 includes an image processing device 17 connected to the I / O port 16D.

[0022] The control device 16 is connected to the network 130 via the communication interface 16F. The communication interface 16F is an interface for communicating with other devices, and for example, standards such as Ethernet (registered trademark), FDDI, Wi-Fi (registered trademark), etc. are used.

[0023] The image processing device 17 generates an image of the eye to be examined 12 based on the data obtained by the imaging device 14.

[0024] In FIG. 6, the control device 16 of the ophthalmic device 110 includes the input / display device 16E, but the technology of the present disclosure is not limited thereto. For example, the control device 16 of the ophthalmic device 110 may not include the input / display device 16E, and may be provided with a separate input / display device physically independent of the ophthalmic device 110.

[0025] The imaging device 14 captures an image of the eye to be examined 12. The imaging device 14 operates under the control of the control device 16. The imaging device 14 includes an imaging optical system 19, an SLO (Scanning Laser Ophthalmology, hereinafter referred to as SLO) unit 18, and an OCT (Optical Coherence Tomography, hereinafter referred to as OCT) unit 20. Hereinafter, a front view image of the retina created based on the SLO data acquired by the SLO unit 18 is referred to as an SLO image, and a tomographic image or an en-face image of the retina created based on the OCT data acquired by the OCT unit 20 is referred to as an OCT image.

[0026] The imaging optical system 19 includes an optical path combining element 21, a first scanner 22, a second scanner 24, and an objective optical system 26. The optical path combining element 21 is a half mirror or a beam splitter, and the first scanner 22 and the second scanner 24 are optical scanners.

[0027] First, the acquisition of OCT images will be described. The light emitted from the OCT unit 20 and passing through the optical path synthesizing element 21 is scanned in the X-axis direction by the first scanner 22. The second scanner 24 scans the light emitted from the OCT unit 20 in the Y direction. The first scanner 22 and the second scanner 24 may be any optical elements capable of deflecting a light beam. For example, a polygon mirror, a galvanometer mirror, or the like can be used. Also, a combination thereof may be used. Note that the first scanner 22 and the second scanner 24 may be configured as one optical scanner. A raster scan or a spiral scan is performed using the first scanner 22 and the second scanner 24. The raster scan is mainly performed as a B scan (scanning along a line), and the spiral scan is mainly performed as a C scan (scanning a wide area).

[0028] The objective optical system 26 is an optical system that guides the light guided by the first scanner 22 and the second scanner 24 to the eye to be examined 12. Note that the objective optical system 26 may be a reflective optical system using a concave mirror such as an elliptical mirror, a refractive optical system using a wide-angle lens or the like, or a refractive-reflective optical system combining a concave mirror and a lens. By using a wide-angle optical system using an elliptical mirror, a wide-angle lens, or the like, it becomes possible to photograph the retina not only at the center of the fundus but also at the peripheral part of the fundus.

[0029] And, the OCT unit 20 is provided with a focus adjustment mechanism 28 for adjusting the focus of the measurement light. The focus adjustment mechanism 28 is one of the optical adjustment mechanisms described later.

[0030] The OCT unit 20 includes a light source 20A, a sensor (detection element) 20B, a first optical coupler 20C, a reference optical system 20D, a collimating lens 20E, and a second optical coupler 20F.

[0031] The light emitted from the light source 20A is branched by the first optical coupler 20C. One of the branched lights is collimated by the collimating lens 20E as measurement light and then incident on the imaging optical system 19. The measurement light is scanned in the X direction and the Y direction by the first scanner 22 and the second scanner 24. The scanned light is irradiated onto the fundus via the objective optical system 26 and the pupil 27. The measurement light reflected by the fundus is incident on the OCT unit 20 via the objective optical system 26, the second scanner 24, and the first scanner, and then incident on the second optical coupler 20F via the collimating lens 20E and the first optical coupler 20C.

[0032] The other light emitted from the light source 20A and branched by the first optical coupler 20C is incident on the reference optical system 20D as reference light, and then incident on the second optical coupler 20F via the reference optical system 20D. These lights incident on the second optical coupler 20F, that is, the measurement light reflected by the fundus and the reference light, are interfered by the second optical coupler 20F to generate interference light. The interference light is received by the sensor 20B. The image processing device 17 operating under the control of the image processing unit 105 generates OCT images such as tomographic images and en-face images based on the OCT data detected by the sensor 20B.

[0033] Next, the acquisition of the SLO image will be described. First, the SLO unit 18 will be described. As shown in FIG. 6, the SLO unit 18 includes a light source 40 for B (blue light), a light source 42 for G light (green light), a light source 44 for R light (red light), and a light source 46 for IR light (infrared light (for example, near-infrared light)), and optical systems 48, 50, 52, 54, 56 that reflect or transmit the light from the light sources 40, 42, 44, 46 and guide it to one optical path. The optical systems 48, 50, 56 are mirrors, and the optical systems 52, 54 are beam splitters. The B light is reflected by the optical system 48, transmitted through the optical system 50, and reflected by the optical system 54. The G light is reflected by the optical systems 50 and 54. The R light is transmitted through the optical systems 52 and 54. The IR light is reflected by the optical systems 52 and 56 and guided to one optical path respectively.

[0034] The SLO unit 18 is configured to be able to switch between a mode that emits G light, R light, and B light, and a combination of light sources that emit laser light with different wavelengths, such as a mode that emits infrared light. In the example shown in FIG. 2, it includes four light sources: a light source 40 for B light (blue light), a light source 42 for G light, a light source 44 for R light, and a light source 46 for IR light. However, the technology of the present disclosure is not limited to this. For example, the SLO unit 18 may further include a light source for white light and emit light in various modes such as a mode that emits only white light.

[0035] The light incident from the SLO unit 18 on the imaging optical system 19 passes through the optical path combining element 21 and is scanned in the X direction and the Y direction by the first scanner 22 and the second scanner. The scanned light is irradiated onto the posterior part of the eye to be examined 12 (fundus) via the pupil 27. The reflected light reflected by the fundus is incident on the SLO unit 18 via the imaging optical system 19, the first scanner 22, and the second scanner. In the case of taking an SLO image, raster scanning is mainly used.

[0036] The SLO unit 18 includes a beam splitter 64 that reflects B light and transmits light other than B light among the light from the posterior part of the eye to be examined 12 (fundus), and a beam splitter 58 that reflects G light and transmits light other than G light among the light transmitted through the beam splitter 64. The SLO unit 18 includes a beam splitter 60 that reflects R light and transmits light other than R light among the light transmitted through the beam splitter 58. The SLO unit 18 includes a beam splitter 62 that reflects IR light among the light transmitted through the beam splitter 60. The SLO unit 18 includes a B light detection element 70 that detects the B light reflected by the beam splitter 64, a G light detection element 72 that detects the G light reflected by the beam splitter 58, an R light detection element 74 that detects the R light reflected by the beam splitter 60, and an IR light detection element 76 that detects the IR light reflected by the beam splitter 62.

[0037] The light (reflected light reflected by the fundus) incident on the SLO unit 18 via the second scanner 24, the first scanner 22, and the optical path combining element 21 is reflected by the beam splitter 64 and received by the B light detection element 70 in the case of B light, transmitted through the beam splitter 64, reflected by the beam splitter 58, and received by the G light detection element 72 in the case of G light. The incident light is transmitted through the beam splitters 64 and 58, reflected by the beam splitter 60, and received by the R light detection element 74 in the case of R light. The incident light is transmitted through the beam splitters 64, 58, and 60, reflected by the beam splitter 62, and received by the IR light detection element 76 in the case of IR light. The image processing device 17 operating under the control of the CPU 16A generates an SLO image using the signals detected by the B light detection element 70, the G light detection element 72, the R light detection element 74, and the IR light detection element 76.

[0038] Various functions realized by the CPU 16A of the ophthalmic device 110 executing the scan program will be described. As shown in FIG. 7, the scan program includes a scan control function, a display control function, an optical adjustment function, an image processing function, a communication function, and a processing function as its functional configuration. By the CPU 16A executing the scan program having these functions, the CPU 16A functions as a scanner control unit 101, a display control unit 102, a processing unit 103, an optical adjustment unit 104, and an image processing unit 105. The scanner control unit 101 controls the first scanner 22 and the second scanner 24. Specifically, the scanner control unit 101 includes an orbit calculation unit 111 and a scanner drive unit 112.

[0039] FIG. 8 is a flowchart showing the flow of the scan processing routine by the ophthalmic device 110. The scan processing routine is executed by the CPU 16A reading the scan program from the ROM 16C or the storage, expanding it in the RAM 13, and executing it.

[0040] In step S100, the display control unit 102 generates image data of a setting screen 1500 for setting spiral scan parameters. The image data of the setting screen 1500 is transmitted to the input / display device 16E, and the setting screen 1500 is displayed on the input / display device 16E.

[0041] Specifically, the display control unit 102 generates image data of a setting screen 1500 including a first GUI for setting spiral scan parameters and a second GUI for checking a scan trajectory by a scanner drive signal. Here, GUI is a Graphical User Interface. For example, the first GUI is a GUI capable of individually inputting spiral scan parameters or a GUI capable of selecting a set of spiral scan parameters preset or registered by the user. That is, the first GUI accepts input of spiral scan parameters by individual input or selection. Also, frequently used parameter settings and user-preferred parameter settings are prepared in advance and stored in the RAM 16B as a plurality of scan modes. That is, in one scan mode, a plurality of parameter values for defining one spiral scan are grouped together (constituting a parameter group), and a name indicating the “plurality of parameter values” (for example, the character string “user setting 1” for the parameter group of the spiral scan frequently used by the user) is assigned, and the parameter group and the character string are stored as a set in the “user setting 1 mode”. And it is configured to be able to store a plurality of such scan modes. In this case, the first GUI may be configured to be able to select a scan mode.

[0042] Furthermore, as scanning modes, an anterior segment scanning mode for photographing the anterior segment of the eye to be examined, such as the cornea and the lens, and a posterior segment scanning mode for photographing the posterior segment (fundus) of the eye to be examined, such as the retina and the vortex vein, may be selectable. The anterior segment scanning mode is a spiral scanning mode in which a group of parameters optimal for spiral scanning for photographing the anterior segment is set in advance. The posterior segment scanning mode is a spiral scanning mode in which a group of parameters optimal for spiral scanning for photographing a wide range of the fundus is set in advance. Then, the scanning parameters received by the first GUI are used for the calculation of the scan by the trajectory calculation unit 111.

[0043] The second GUI displays a superimposed image in which the scan trajectory by the scanner drive signal is superimposed on the posterior segment image or the anterior segment image of the eye to be examined. The superimposed image displays, as a foreground image, the scan trajectory of the spiral scan based on the scanner drive signal calculated by the trajectory calculation unit 111 based on the spiral scan parameters currently input to or selected by the first GUI. The superimposed image also displays, as a background image, the posterior segment image or the anterior segment image of the eye to be examined that has been photographed in advance. The posterior segment image or the anterior segment image may be read from the RAM 16B or the server 140 and used, for example, as an image of the eye to be examined of a patient photographed in the past. Further, when the trajectory calculation unit 111 has a function of determining whether a spiral trajectory can be correctly calculated, when parameters that cannot correctly calculate the spiral trajectory are set, image data may be generated so as to display, within the screen of the second GUI, text or an image indicating a warning informing the user that the parameters are incorrect.

[0044] Here, the setting screen 1500 will be described with reference to FIG. 15. As shown in FIG. 15, the setting screen 1500 includes a patient information identification information display column 1500A for displaying the identification information of the patient, a first GUI display column 1500B which is a screen for setting the spiral scan parameters, and a second GUI display column 1500C on which the superimposed image is displayed. As the superimposed image, not only the SLO image obtained by photographing the fundus, but also a schematic diagram of the fundus or a three-dimensional image (3D model) of the eye to be examined with the spiral scan trajectory superimposed thereon may be used. The image on which the trajectory is superimposed may be an image of the eye to be examined in a two-dimensional image or a three-dimensional image. When performing a spiral scan of the anterior segment of the eye, an image obtained by photographing the anterior segment of the eye to be examined with an anterior segment camera (not shown) may be used as the background image.

[0045] Further, the setting screen 1500 may display the predicted measurement time calculated by the trajectory calculation unit 111 based on the scan parameters, that is, the time required to execute the set spiral scan. In this case, the scan parameters set in the past and the measurement time actually required to capture the OCT image with the scan parameters are stored in the RAM 16B, and when the conditions are the same as the past measurement, the measurement time may be read from the RAM 16B and displayed.

[0046] Here, the coordinate system of the spiral scan according to this embodiment will be described with reference to FIG. 9. In the spiral scan according to this embodiment, the coordinate system is defined by the incident angle to the eye to be examined. A direction perpendicular to the pupil plane passing through the pupil center of the eye to be examined is defined as the Z-axis (optical axis), the left-right direction is defined as the X-axis, and the up-down direction is defined as the Y-axis. The angle formed by the incident light beam, which is the light beam emitted from the OCT unit 20 and incident on the eye to be examined, and the optical axis is the incident angle θ to the eye to be examined. FIG. 9 shows an example in which the incident light beam passes through the pupil center from the lower right and heads to the upper left. The incident angle θ is defined by the incident angle component in the X-axis direction and the incident angle component in the Y-axis direction. In this embodiment, the incident angle in the X-axis direction is denoted as θx, and the incident angle in the Y-axis direction is denoted as θy. That is, the incident angle θx is used as the first drive signal for driving the first scanner 22. And θy is used as the second drive signal for driving the second scanner 24. Thereby, it is possible to drive the first scanner 22 and the second scanner 24 with the light beam irradiated from the OCT unit 20 and irradiate the eye to be examined at a desired incident angle θ. Therefore, by changing the incident angles θx and θy for each sampling time interval, a spiral scan can be realized.

[0047] The spiral scan parameters are parameters used when the ophthalmic device 110 performs a spiral scan on the eye to be examined. The spiral scan parameters are the incident angles of light with respect to a plane in a plane orthogonal to the axis perpendicular to the pupil plane of the eye to be examined, and are described by a plurality of types of parameters including incident angle data indicating the correspondence between time and the incident angle.

[0048] Specifically, the spiral scan parameters include at least the type of spiral, the scan range, the start position {θ x0 , θ y0} of the spiral scan, and the sampling interval L.

[0049] The parameters of the spiral type are information for defining the shape of the spiral. The shape of the spiral can be represented in polar coordinates (distance r from the center of the spiral and angle Θ from the reference position). Since Θ is an angle that changes at each sampling interval, using r and Θ, the spiral shape can be, for example, · Uniform spiral (Archimedes spiral): r = aΘ · Parabolic spiral: r = a√Θ · Hyperbolic spiral: r = a / Θ · Lituus: r = a / √Θ · Logarithmic spiral: r = ae (bΘ) The spiral shapes determined by equations such as the above can be adopted. Here, a and b are constants, and e is the Euler's constant. For the spiral type, any of the above various spiral equations can be used. Hereinafter, the case where the uniform spiral is selected will be described as an example.

[0050] The spiral shape parameters consist of a code indicating the basic shape of the shape such as the above-mentioned uniform spiral and coefficients a, coefficients b, etc., and are parameters that form the basis of the orbit calculation in the orbit calculation unit 111.

[0051] The scan range parameters are parameters for determining the imaging range of the eye to be examined. The scan range parameters include the inner diameter r which is the minimum value of the radial direction r min and the outer diameter r which is the maximum value of the radial direction r max . That is, when the inner diameter r min and the outer diameter r max are determined, r min < r < r max is scanned. Further, the scan range parameters can include the ellipticity c and the orientation {dx, dy} of the ellipse. The incident angles θx and θy can be represented by the radial direction r and the circumferential direction θ of the angle formed by the optical axis with respect to the plane in a plane orthogonal to the optical axis which is an axis perpendicular to the pupil plane of the eye to be examined. When the equation of the above-mentioned uniform spiral polar coordinate system is converted into a rectangular coordinate system, the relationship between the incident angles θx and θy and the radial direction r and the circumferential direction θ is as shown in the following formula (1) for the aforementioned general spiral.

[0052]

Number

[0053] Therefore, adding the ellipticity c and the orientation {dx, dy} of the ellipse to the above formula (1), it is expressed as the following formula (2).

[0054]

Number

[0055] Here, θ is an angular value that changes for each sampling interval L. θ is defined between the start point and the end point of the spiral scan. a is a parameter that defines the interval (number of turns) between the lines of the spiral, c is a parameter that specifies the ellipticity, and dx and dy are parameters that define the orientation of the ellipse, respectively.

[0056] The scan trajectory parameters can be determined by defining the time variation of θ. For example, the scan trajectory parameters can be expressed as a function with time as a variable, such as θ = αt. As long as the relationship between θ and the time t can be defined, it is not necessarily required to be expressed by a mathematical formula, and it may be a parameter consisting of a data group in which the values of θ for each time are recorded one by one. Note that the time differential value of θ is always positive when the scan direction is from the inside to the outside, and always negative when the scan direction is from the outside to the inside. For example, in the case of θ = αt, when θ is monotonically decreasing, the time differential value α of θ is always α < 0, so the scan direction is from the outside to the inside (right in Figure 10). On the other hand, when θ is monotonically increasing, the time differential value α of θ is always α > 0, so the scan direction is from the inside to the outside (left in Figure 10). Such a scan direction can be included in the spiral scan parameters. That is, it is possible to specify whether the scan direction is from the outside to the inside or from the inside to the outside of the spiral.

[0057] The start position parameters {θ x0 , θ y0}{is the start time t of the spiral scan 0 at the incident angles θx and θy, and the end position {θ xtf , θ ytf}} is the incident angles θx and θy at the end time t f of the spiral scan.

[0058] The sampling interval parameter L is a parameter indicating the interval at which the spiral scan is used to scan the eye to be examined. That is, the sampling interval parameter L is the circumferential sampling interval, and can be said to be the moving distance (the length of the spiral) at the sampling time interval. The value of a in the above formula (2) determines the number of turns of the ellipse and determines the radial sampling interval (that is, the interval between lines). By determining the time change of θ, the circumferential sampling interval is determined. When the value of a is large, the number of turns of the spiral decreases, and the whole is photographed roughly (left in Figure 11). When the value of a is small, the number of turns of the spiral increases, and the whole is photographed finely (middle in Figure 11).

[0059] Also, the sampling interval parameter L can be arbitrarily determined by the time change of θ. For example, when θ is proportional to t, while photographing the center finely, it is photographed roughly as it goes outwards (right in Figure 11). In the case of the right in Figure 11, there may be a lot of information to be examined and observed in the center part, so it is effective in such a case. Let the sampling times be t 1 , t 2 , …. In this case, the sampling interval L 1 from a certain time t 2 to the next time t (t1→t2) can be expressed by the following formula (3).

[0060] [Number]

[0061] According to the above formula (3), the time changes of the incident angles θx and θy may be determined such that the value of the sampling interval L changes in a desired form for each time. For example, when setting the sampling interval L at equal intervals, for each time interval t s →t s+1 it is sufficient to ensure that the value of L is always constant.

[0062] In addition, the spiral center position (X, Y) can be included in the scan parameters. When photographing the eye to be examined, the part of the eye to be examined that one wishes to examine is not necessarily limited to the range centered on the center of the eye to be examined (for example, the optic nerve head). For example, it is also conceivable to perform a spiral scan centered on the vortex vein existing near the equator of the fundus.

[0063] Therefore, by including the spiral center position (X, Y) defined in polar coordinates in the scan parameters, it is possible to photograph the eye to be examined with higher accuracy according to the requirements. The spiral center position (X, Y) can be expressed by the following formula (4) obtained by adding X and Y to the above formula (2).

[0064]

Equation

[0065] The center of the spiral can be shifted to a predetermined position by the spiral center position (X, Y). For example, as shown in FIG. 12, the center position of the spiral is shifted by (X, Y).

[0066] Here, an example of a scan trajectory that can be set by the spiral scan parameters will be described. FIGS. 13 and 14 are diagrams showing examples of scan trajectories. When the outer diameter r max is reduced, only the vicinity of the center of the spiral can be photographed (left in FIG. 13). On the other hand, the inner diameter r minWhen it is enlarged, it is possible to photograph a ring-shaped region on the outer periphery of the eye to be examined excluding the central part of the spiral (in the middle of FIG. 13). Further, by setting the ellipticity c to a value other than 1, the region can be made elliptical (on the right in FIG. 13). Regarding the direction {dx, dy} of the ellipse, by setting values other than dx = dy = 0, the axis of the ellipse can be rotated (on the left in FIG. 14). By combining these, various variations such as photographing only the outside and elliptical (in the middle of FIG. 14), and further changing the orientation (on the right in FIG. 14) can be realized.

[0067] Therefore, for the eye to be examined, it is possible to efficiently photograph only the desired examination range. Also, the above-described spiral scan parameters are merely examples and can be set variously within a range not departing from the spirit of the present disclosure.

[0068] The above-described scan parameters are set by the user using the first GUI 1500B of the setting screen 1500 displayed on the input / display device 16E. In step S100, when the setting of the scan parameters is completed, the scan parameters are stored in the RAM 16B (step S101).

[0069] In step S102, the trajectory calculation unit 111 reads out the spiral scan parameters set by the user from the RAM 16B via the processing unit 103. The trajectory calculation unit 111 calculates a scan trajectory based on the set spiral scan parameters. Then, the trajectory calculation unit 111 passes the calculated scan trajectory to the display control unit 102. Note that the trajectory calculation unit 111 may have a function of determining whether a correct spiral trajectory can be calculated with the set spiral scan parameters. For example, a spiral trajectory with too few turns such as 1 or 2, or a case where the spiral trajectory exceeds the scanable range (exceeds the maximum angle of view of the ophthalmic device 110) can be considered. When such a substantially unphotographable spiral trajectory is calculated, a message prompting the user for re-setting may be notified, or the trajectory calculation unit 111 may calculate appropriate scan parameters and propose the appropriate scan parameters to the user.

[0070] In step S103, the display control unit 102 generates a second GUI in which the scan trajectory by the scanner drive signal calculated in step S102 is superimposed on the fundus image, which is the captured eye image, updates the above-described setting screen 1500, and displays the updated setting screen on the input / display device 16E. When the object of the spiral scan is the fundus, the graphic data of the scan trajectory is superimposed on the SLO image of the fundus, which is the background image. On the other hand, when the object of the spiral scan is the anterior segment of the eye, the graphic data of the scan trajectory is superimposed on the image of the anterior segment of the eye, which is the background image. Further, when superimposing the background image and the graphic data of the scan trajectory, processing such as enlarging and reducing the graphic data of the scan trajectory according to the size of the background image and aligning the positions of the background image and the graphic data of the scan trajectory is performed.

[0071] In step S104, the trajectory calculation unit 111 determines, via the processing unit 103, whether or not the user has accepted the determination of the spiral scan parameters (that is, the determination to perform measurement on the scan trajectory of the second GUI displayed in the second GUI display column 1500C of FIG. 15) on the input / display device 16E.

[0072] If the determination has not been accepted (NO in step S104 above), the process returns to step S100. Then, when the scan parameters are set again, the scan trajectory is redisplayed using the reset scan parameters.

[0073] On the other hand, if the determination has been accepted (YES in step S104 above), in step S105, a scanner drive signal and an adjustment amount of the optical adjustment mechanism corresponding to the scanner drive signal are generated.

[0074] First, the scanner drive unit 112 generates a first drive signal for the first scanner 22 in the X direction and a second drive signal for the second scanner 24 in the Y direction for scanning along the scan trajectory based on the determined spiral scan parameters.

[0075] Next, based on the generated scanner drive signal, the optical adjustment unit 104 calculates the adjustment amount at the timing of each sampling (i.e., the timing of each A-scan). When the optical adjustment mechanism is the focus adjustment mechanism 28, based on the focus adjustment amount, the focus lens is driven in the optical axis direction, and the focus adjustment is executed.

[0076] Alternatively, instead of setting the adjustment amount of the optical adjustment mechanism for each A-scan, the scan trajectory may be divided into a plurality of sections, and the adjustment amount may be set for each section.

[0077] Note that the optical adjustment mechanism is not limited to the focus adjustment mechanism 28. It may be an adjustment mechanism that adjusts optical parameters that change depending on the distance from the pupil to the retina, such as an optical path length adjustment mechanism, a dispersion adjustment mechanism, a polarization adjustment mechanism, etc. Furthermore, these adjustment mechanisms are not limited to one, and there may be a plurality of them.

[0078] Here, the adjustment of the optical adjustment mechanism performed during spiral scan execution will be described.

[0079] When scanning the peripheral part of the fundus compared to when scanning the central part of the fundus, the distance from the pupil to the retina becomes shorter. Therefore, the optical adjustment unit 104 makes an adjustment to increase the diopter as the focus adjustment amount. For example, if it was 0 diopter (no adjustment) at the central part of the fundus, the adjustment is made to gradually increase to +0.5 diopter and +1.0 diopter as it goes to the peripheral part of the fundus. However, the focus adjustment amount at the central part of the fundus and the rate of change of the adjustment amount when going to the periphery vary depending on the eye under examination (patient). This focus adjustment is performed both during OCT imaging and during SLO imaging. Conversely, in a spiral scan from the peripheral part of the fundus to the central part of the fundus, the adjustment is made to gradually decrease to -0.5 diopter and -1.0 diopter as it goes to the peripheral part of the fundus. The adjustment amount may be changed according to the incident angle of the incident light for imaging on the pupil.

[0080] In addition, as optical adjustments performed only during OCT imaging, there are 1) optical path length adjustment of the reference optical path and 2) dispersion adjustment for adjusting the dispersion between the reference light and the measurement light.

[0081] 1) The optical path length adjustment is to adjust so that the optical path length of the measurement light and the optical path length of the reference light are the same. Assume that an optical path length adjustment mechanism (not shown) (composed of a driving device for driving a reference mirror for adjusting the optical path length by a motor or the like) is in the reference optical path. The optical adjustment unit 104 outputs an adjustment instruction to the optical path adjustment mechanism so as to perform adjustment such that the optical path length of the reference light becomes shorter when scanning the peripheral part of the fundus than when scanning the central part of the fundus. Further, when the optical path length adjustment mechanism is in the optical path of the measurement light, the optical adjustment unit 104 outputs an adjustment instruction to the optical path adjustment mechanism so as to perform adjustment such that the optical path length of the measurement light becomes longer when scanning the peripheral part of the fundus than when scanning the central part of the fundus. By this optical path length adjustment, the optical path length of the reference light and the optical path length of the measurement light become the same depending on the location of the central part or the peripheral part of the fundus, and OCT imaging including OCT data of an appropriate depth can be performed.

[0082] 2) The dispersion adjustment is to perform adjustment so that the dispersion of the reference optical path becomes the same as the dispersion of the measurement optical path. The dispersion varies depending on the distance that the measurement light passes through the lens of the eye to be examined. In the scan during OCT imaging, the distance that the measurement light passes through the lens varies depending on the incident angle of the measurement light to the pupil. The distance that the measurement light passes through the lens is longer and the dispersion becomes larger in the scan of the central part of the fundus. On the other hand, in the scan of the peripheral part of the fundus, the distance that the measurement light passes through the lens is shorter and the dispersion becomes smaller. Accordingly, the dispersion adjustment mechanism is controlled so that the amount of dispersion on the reference optical path side becomes the same as the amount of dispersion of the optical path on the measurement light side (so that the dispersion becomes smaller when scanning the peripheral part of the retina than when scanning the central part of the retina). The dispersion adjustment mechanism may be a mechanism such as one that can adjust the degree of twist of an optical fiber or the like. Alternatively, it may be performed by data processing for correcting the amount of dispersion with respect to the OCT data instead of adjusting with a mechanism.

[0083] Furthermore, polarization adjustment exists. Polarization adjustment is to adjust the amount of polarization shift that occurs according to the distance that light passes through the lens in the eye.

[0084] The amount of polarization varies according to the distance that the measurement light passes through the lens of the eye to be examined. In the scan during OCT imaging, the distance passing through the lens varies depending on the entry angle of the measurement light into the pupil. The distance that the measurement light passes through the lens is longer in the scan of the central part of the fundus, and the amount of polarization shift becomes larger. On the other hand, in the scan of the peripheral part of the fundus, the distance that the measurement light passes through the lens is shorter, and the polarization shift becomes smaller. Accordingly, the polarization adjustment mechanism is controlled so that the amount of polarization on the reference optical path side becomes the same as the amount of polarization on the optical path side of the measurement light (so that the polarization becomes smaller when scanning the peripheral part of the retina compared to when scanning the central part of the retina). The polarization adjustment mechanism includes a mechanism that adjusts polarization by rotating a polarizing plate.

[0085] There are, for example, the following methods for determining the adjustment amount of the optical adjustment mechanism. The adjustment amounts (such as the focus adjustment amount, the optical path length adjustment amount, the dispersion adjustment amount, the polarization adjustment amount, etc.) described above are prepared by the optical adjustment mechanism mounted on the ophthalmic device 110 in the following manner.

[0086] · Method 1: Perform adjustment at a representative position (usually the central axis of the eye to be examined) to obtain the adjustment amount, calculate the distance from the pupil to the retina for each incident angle based on the model of the eye to be examined, and then determine the adjustment amount for each time based on the calculated distance. Here, the model of the eye to be examined may be a spherical model or may be configured to use a model such as Navarro.

[0087] · Method 2: Perform adjustment over the entire scan range before imaging to create an adjustment amount map. At the time of imaging, determine the adjustment amount for each time based on the created adjustment amount map and the scan trajectory.

[0088] · Method 3: Measure the distance from the pupil to the retina over the entire scan range before imaging to create the shape data of the eyeball. At the time of imaging, determine the adjustment amount for each time based on the created shape data of the eyeball and the scan trajectory.

[0089] In step S106, the scanner drive unit 112 moves the first scanner 22 and the second scanner 24 to their initial positions based on the initial values of the scan drive signals for the first scanner 22 and the second scanner 24 (drives the first scanner 22 and the second scanner 24 so that the reflecting surfaces of the first scanner 22 and the second scanner 24 are at the initial angles).

[0090] Then, the optical adjustment unit 104 controls the optical adjustment mechanism to move to the initial position (set to the initial adjustment amount). For example, the focus adjustment mechanism 28 moves the focus lens so that the focus is adjusted at the start position of the scan.

[0091] In step S107, the scanner drive unit 112 drives the first scanner 22 based on the first scanner drive signal and drives the second scanner 24 based on the second scanner signal. At the same time, the optical adjustment unit 104 controls the focus adjustment mechanism 28 based on the adjustment amount of the focus adjustment mechanism. Note that it may be configured to have a function of measuring the movement of the eye to be examined in real time using an eye tracking function or the like and applying feedback to follow the movement of the eye to be examined.

[0092] In step S108, the image processing unit 105 performs Fourier transform or the like on the detection signal acquired by the sensor 20B of the OCT unit 20 along the scan trajectory formed by the processing in step S107 above, and generates A-scan data (OCT data).

[0093] In step S109, the image processing unit 105 performs a conversion to arrange the A-scan data arranged in the sampling order along the scan trajectory in a grid pattern. This is a conversion for reconstructing the A-scan data into a two-dimensional or three-dimensional grid pattern in order to perform image processing smoothly. That is, since the sample point positions of the data obtained by spiral scan are arranged in a spiral shape (left figure in Fig. 16), in order to enable digital processing, it is converted into a grid pattern (right figure in Fig. 16). The position information of the sample points may be calculated from the spiral trajectory and the data of the sampling frequency, or the position information (angle information of the reflecting surface) of the first scanner 22 and the second scanner 24 at each sample point may be calculated from the first drive signal and the second drive signal and used.

[0094] In step S110, the image processing unit 105 generates an OCT image such as a tomographic image of the retina or a three-dimensional image of the retina from the converted data. Then, the image processing unit 105 outputs the generated OCT image to the display control unit 102.

[0095] In step S111, the display control unit 102 displays the OCT image generated in step S110 on the input / display device 16E. Further, the processing unit 103 combines the OCT image and the patient identification information and transmits them to the management server 140. The management server 140 stores the combined OCT image and patient identification information.

[0096] In FIG. 8 described above, a scan processing routine in which the user operates the ophthalmic apparatus 110 to perform spiral scan settings was explained. Next, a modified example in which the user performs spiral scan settings using the image viewer 150 of the ophthalmic system 100 will be explained.

[0097] FIG. 17 is a flowchart showing a process in which the user performs spiral scan settings using the image viewer 150 and an image taken based on the spiral scan executed by the ophthalmic apparatus 110 is displayed on the image viewer 150.

[0098] Hereinafter, with reference to FIG. 17, the processing executed by the CPU of the image viewer 150 will be described. In step S200, the image viewer 150 displays the setting screen 1500 (FIG. 15) received from the ophthalmic device 110 via the network 130. The setting screen 1500 (FIG. 15) displayed on the image viewer 150 is the same screen as the setting screen 1500 displayed on the ophthalmic device 110.

[0099] In step S201, the image viewer 150 receives the spiral scan parameters input by the user from the setting screen 1500.

[0100] In step S202, the image viewer 150 transmits the input spiral scan parameters to the ophthalmic device 110 via the network 130.

[0101] In step S203, the image viewer 150 checks whether the spiral scan is as intended by the user by viewing the superimposed image (a superimposed image in which the scan trajectory is superimposed on the posterior eye image or anterior eye image of the eye to be examined, generated by the ophthalmic device 110 and received via the network 130) created based on the set spiral scan parameters. If the spiral scan is okay, the user operates the decision button on the setting screen 1500, and the scan parameters will be determined.

[0102] In step S204, the image viewer 150 determines whether the determination of the scan parameters has been input.

[0103] If the determination of the scan parameters has not been input (NO in step S204 above), the image viewer 150 displays a message for the user to re-set the scan parameters or the like, and then returns to step S200. On the other hand, if the determination of the scan parameters has been input (YES in step S204 above), in step S205, the image viewer 150 transmits the received determination to the ophthalmic device 110 via the network 130.

[0104] In step S206, the image viewer 150 receives the OCT image captured by the ophthalmic device 110 using the spiral scan parameters determined via the network 130.

[0105] In step S207, the image viewer 150 displays the OCT image received in step S207. Thus, by executing the processing routine of FIG. 17, the scan parameters can be set from a remote location via the image viewer 150.

[0106] As described above, according to the scan method according to the embodiment of the present disclosure, there is provided a scan method for scanning an eye to be examined, in which a computer determines spiral scan parameters for spiral scanning the eye to be examined, generates a scanner drive signal in the spiral scan parameters, and controls the scanner based on the scanner drive signal, so that stable and accurate imaging can be realized.

[0107] In addition, by displaying a setting screen 1500 for setting the spiral scan parameters, imaging according to the user's requirements can be realized.

[0108] In addition, by displaying a superimposed image in which the scan trajectory by the scanner drive signal is superimposed on the posterior eye image or the anterior eye image of the eye to be examined, the user can confirm the imaging of the eye to be examined desired by the user, so that accurate imaging can be realized.

[0109] In addition, by displaying a setting screen 1500 including a first GUI (Graphical User Interface) for setting the spiral scan parameters and a second GUI for confirming the scan trajectory by the scanner drive signal, the user can confirm the imaging of the eye to be examined desired by the user, so that accurate imaging can be realized.

[0110] In addition, OCT data is A-scan data arranged in a spiral shape, and the computer can achieve accurate imaging by performing a conversion that arranges the A-scan data arranged in a spiral shape in a grid pattern.

[0111] In addition, the spiral scan parameters include, in a plane orthogonal to the axis perpendicular to the pupil plane of the eye to be examined, the incident angle of light with respect to the plane, and the incident angle data showing the correspondence between time and the incident angle, so that the scan trajectory can be set, and thus imaging according to the user's requirements can be achieved.

[0112] In addition, the spiral scan parameters are the incident angle of light with respect to the plane in a plane orthogonal to the axis perpendicular to the pupil plane of the eye to be examined, and the incident angle is represented by the radial direction and the circumferential direction of the angle formed by the optical axis with respect to the plane, so that the scan trajectory can be easily set, and thus imaging according to the user's requirements can be achieved.

[0113] In addition, the spiral scan parameters further include at least one of the ellipticity of the spiral and the central position of the spiral, so that the scan trajectory can be freely changed, and thus imaging according to the user's requirements can be achieved.

[0114] In addition, the scanner includes a first scanner that scans in a first direction and a second scanner that scans in a second direction perpendicular to the first direction, the scanner drive signal includes a first drive signal θx for driving the first scanner and a second drive signal θy for driving the second scanner, and the first drive signal θx and the second drive signal θy are defined by the above formula (2). For example, the first direction is the X-axis direction and the second direction is the vertical direction. Therefore, it becomes easier to set the scan trajectory, and thus imaging according to the user's requirements can be achieved.

[0115] In addition, by using spiral scanning, since the speed difference in the change of the driving angles of the vertical axis and the horizontal axis is small, stable and accurate imaging can be realized. Furthermore, by using spiral scanning, since the change speed of focus adjustment is also small, the processing load can also be suppressed.

[0116] Note that the present disclosure is not limited to the above-described embodiments, and various modifications and applications are possible without departing from the gist of the invention.

[0117] Also, in the above embodiment, the configuration is such that the setting screen 1500 etc. is displayed via communication, but it is not limited thereto. For example, the ophthalmic device 110 and the image viewer 150 may be configured as one device.

[0118] Also, although the setting screen is configured to be created by the CPU 16A of the control device 16 of the ophthalmic device 110, it is also possible to generate the setting screen by the CPU (not shown) of the management server 140 using the fundus image and the axial length of the subject stored in the management server 140, and transmit it to the ophthalmic device 110 or the image viewer 150.

[0119] Also, the image processing device 17 of the ophthalmic device 110 may be implemented as a separate device. In this case, the ophthalmic device 110 and the image processing device 17 may be configured to communicate via the network 130.

[0120] Note that, in the above-described embodiment, the scan program that the CPU reads and executes software (program) may be executed by various processors other than the CPU. Examples of the processor in this case include a PLD (Programmable Logic Device) whose circuit configuration can be changed after manufacturing, such as an FPGA (Field-Programmable Gate Array), and a dedicated electric circuit, which is a processor having a circuit configuration dedicated to executing specific processing, such as an ASIC (Application Specific Integrated Circuit). Further, the scan program may be executed by one of these various processors, or may be executed by a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs, and a combination of a CPU and an FPGA, etc.). More specifically, the hardware structure of these various processors is an electric circuit combining circuit elements such as semiconductor elements.

[0121] That is, a scanning method for scanning the eye to be examined using a scanner and an optical system for guiding light to the eye to be examined, wherein an orbit calculation unit sets spiral scan parameters used for spiral scanning by the scanner, generates a scanner drive signal in the spiral scan parameters, and a control unit controls the scanner based on the scanner drive signal may also be used.

[0122] Also, in each of the above embodiments, the mode in which the scan program is pre-stored (installed) in the ROM 16C or the storage has been described, but the present invention is not limited to this. The program may be provided in a form stored in a non-transitory storage medium such as a CD-ROM (Compact Disk Read Only Memory), a DVD-ROM (Digital Versatile Disk Read Only Memory), and a USB (Universal Serial Bus) memory. Further, the program may be in a form downloaded from an external device via a network.

Claims

1. 1. An ophthalmologic apparatus that processes data acquired by helically scanning a subject's eye with light, the apparatus changing an angle of a reflecting surface of a scanner at predetermined time intervals based on a drive signal for controlling the angle of the reflecting surface, the apparatus comprising: a position calculation unit that calculates, from the drive signal, angle information of the reflecting surface of the scanner driven by the drive signal based on a scanning point distance interval parameter, thereby calculating a position of a scanning point on the subject's eye; a conversion unit that converts the positions of the scanning points calculated by the position calculation unit from the spiral to a lattice shape, the scanning point distance interval parameter determines a distance interval of the scanning points in a circumferential direction in the helical scan based on a correspondence relationship between an incident angle with respect to the subject's eye and time; An ophthalmic apparatus comprising:

2. the position calculation unit calculates the position of the scanning point from angle information of the reflecting surface of the scanner driven by the drive signal based on the scanning point distance interval parameter in the radial direction determined by the number of turns of the spiral in the spiral scan; The ophthalmic device according to claim 1 .

3. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal generated based on scanning parameters including at least one parameter of a spiral type parameter, a scanning range parameter, a scanning start position parameter, a scanning end position parameter, and an ellipticity parameter in the spiral scanning; An ophthalmic apparatus according to claim 1 or 2.

4. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal generated based on the scanning parameters including a center position of the spiral, an inner radius and an outer radius from the center position, and a range of the spiral scanning excluding the center range of the spiral; An ophthalmic apparatus according to claim 3.

5. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal based on the scanning parameters including a correspondence relationship between an incident angle of light with respect to a plane orthogonal to an axis perpendicular to a pupil plane of the subject's eye and time; An ophthalmic apparatus according to claim 3 or 4.

6. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal generated for performing the spiral scan along a scanning trajectory based on the set scanning parameters; The ophthalmic apparatus according to any one of claims 3 to 5.

7. the position calculation unit calculates the position of the scanning point from angle information of a reflective surface of the scanner driven by the drive signal generated based on the scanning parameters including a start position parameter of the helical scan, which is an incident angle at a start time of the helical scan, and an end position parameter of the helical scan, which is an incident angle at a end time of the helical scan; The ophthalmic apparatus according to any one of claims 3 to 6.

8. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal generated based on a posterior eye segment scanning parameter for scanning the posterior eye segment of the subject's eye in a posterior eye segment imaging mode; An ophthalmic apparatus according to any one of claims 1 to 7.

9. the position calculation unit calculates the position of the scanning point from angle information of a reflecting surface of the scanner driven by the drive signal generated based on an anterior-segment scanning parameter for scanning the anterior segment of the subject's eye in an anterior-segment imaging mode; An ophthalmic apparatus according to any one of claims 1 to 8.

10. an optical member for adjusting the light to be irradiated to the subject's eye; an adjustment unit that adjusts the optical member according to a distance from a pupil to a retina; The ophthalmic apparatus according to claim 1 , further comprising:

11. The adjustment unit adjusts at least one of an optical path length of the light, an amount of dispersion of the optical path of the light, a polarization of the light, and a focus. An ophthalmic device according to claim 10.

12. An ophthalmic apparatus according to any one of claims 1 to 11; an image display device that displays a setting screen for setting scanning parameters received from the ophthalmic device via a network; An ophthalmology system comprising:

Images