JP2014097191A - Imaging apparatus, imaging method and program - Google Patents

Abstract

[PROBLEMS] To determine the optimum size and position of a plurality of partial areas in consideration of the influence of information (for example, diopter) indicating the characteristics of the eye to be examined when imaging a plurality of partial areas. To do.
An imaging apparatus uses a designation unit that designates an imaging range of an eye to be examined and information indicating an imaging range according to characteristics of the eye to be examined, and a plurality of images for imaging an eye to be examined in the designated imaging range. A determining unit that determines the size of each of the partial areas and the positions of the plurality of partial areas.
[Selection] Figure 3A

Description

  The present invention relates to an imaging apparatus, an imaging method, and a program.

  At present, various optical devices are used as ophthalmic apparatuses or ophthalmic devices. Among them, for example, an anterior ocular segment photographing machine, a fundus camera, and a confocal laser scanning ophthalmoscope (Scanning Laser Ophthalmoscope: SLO) are used as optical instruments for observing the eyes. Alternatively, optical coherence tomography (OCT apparatus), which is an optical tomographic imaging apparatus using optical interference by low-coherent light, is used as an optical instrument for observing the eye.

  In recent years, regarding an imaging apparatus having a scanning optical system such as SLO and OCT, a high-resolution imaging apparatus capable of observing photoreceptor cells using an adaptive optical system has been proposed.

  Patent Document 1 discloses an SLO that can capture a fundus image with high lateral resolution by using a compensation optical system that detects a wavefront reflected from the fundus and corrects wavefront aberration using a wavefront correction device.

JP 2007-14569 A

  Here, when imaging the eye to be examined by a fundus imaging apparatus having a conventional scanning optical system such as SLO or OCT, the imaging range specified by the operator is different from the actual imaging range. This is because the actual imaging range is the imaging range affected by the characteristics of the eye to be examined (for example, the diopter of the eye to be examined) relative to the designated imaging range (hereinafter referred to as “imaging range according to the characteristics”). Say). Here, when the diopter of the eye to be examined is considered as the characteristic of the eye to be examined, the imaging range affected by the diopter of the eye to be examined is also referred to as “imaging range corresponding to the diopter”. At this time, for example, when the eye to be examined is farsighted, the size of the designated imaging range is smaller than the imaging range corresponding to the diopter, and therefore it may not be possible to image a part of the designated imaging range. Conceivable. In this case, in order to acquire the image of the designated imaging range in the eye to be examined, it is conceivable to image the eye to be examined for each of a plurality of partial areas.

  An object of the present invention is to determine the optimum size and position of a plurality of partial areas in consideration of the effect of the diopter of the subject eye when imaging the eye to be examined for each of a plurality of partial areas.

An imaging apparatus according to one aspect of the present invention that achieves the above object is as follows:
A designation means for designating an imaging range of the eye to be examined;
Using information indicating the imaging range corresponding to the characteristics of the eye to be examined, the size of the plurality of partial areas and the position of the plurality of partial areas for imaging the eye to be examined in the designated imaging range are determined. And a determining means.

  According to the present invention, when the subject eye is imaged for each of the plurality of partial regions, the optimum size and position of the plurality of partial regions are taken into consideration in consideration of the influence of the characteristics of the subject eye (for example, the diopter of the subject eye). It becomes possible to determine.

1 is a diagram illustrating a configuration example of an imaging apparatus according to an embodiment of the present invention. The figure which illustrates the partial area | region for imaging a to-be-examined eye within the designated imaging range. 1 is a diagram illustrating a functional configuration of an imaging apparatus according to an embodiment. 6 is a flowchart of an imaging method by the imaging apparatus according to the embodiment. The figure which illustrates the memory | storage part which memorize | stores the imaging range according to diopter and diopter. The figure which illustrates the designation | designated screen which designates an imaging range. The figure which illustrates the partial area | region in the designated imaging range. The figure which illustrates the imaging center position of each partial area. The figure which illustrates the partial area | region in the designated imaging range. The figure which illustrates the partial area | region in the designated imaging range.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the constituent elements described in the embodiments are merely examples, and the technical scope of the present invention is determined by the claims, and is not limited by the following individual embodiments. .

(Configuration of imaging device)
FIG. 1 is a diagram illustrating a configuration example of an imaging apparatus according to the embodiment, and illustrates a configuration of an SLO using an adaptive optical system (compensating optical unit). The SLO illustrated in FIG. 1 is an example of a scanning laser opthalmoscope / SLO having an adaptive optical function. The configuration of the eyepiece portion is the same in the optical coherence tomography (OCT).

  In FIG. 1, a light source 101 is, for example, an SLD light source having a wavelength of 840 nm. The wavelength of the light source 101 is not particularly limited, but a wavelength of about 800 to 1500 nm is suitably used particularly for fundus photography in order to reduce glare and maintain resolution of the subject. The light emitted from the light source 101 passes through the single mode optical fiber 102 and is irradiated as a parallel light by the collimator 103.

  The irradiated measurement light 105 is transmitted through the light splitting unit 104 and guided to the compensation optical system. The compensation optical system includes a light splitting unit 106, a wavefront sensor 115 that is an example of a wavefront aberration measuring unit, a wavefront correction device 108 that is an example of a wavefront aberration correcting unit, and reflection mirrors 107-1 to 107-4 for guiding them. Have Here, the reflection mirrors 107-1 to 107-4 are installed so that at least the pupil of the eye to be examined, the wavefront sensor 115, and the wavefront correction device 108 are optically conjugate.

  For example, a variable reflection mirror is used as the wavefront correction device 108. However, the present invention is not limited to this example. For example, a liquid crystal spatial light modulator, LCOS (Liquid Crystal On Silicon), or the like can be used. The wavefront correction device 108 is disposed in the optical path of the compensation optical system, and controls the wavefront of the incident light to compensate for the wavefront aberration of the eye to be examined. Here, the wavefront correction device 108 corrects low-order wavefront aberration (diopter: for example, spherical power) of the eye to be examined and a high-order wavefront aberration of the eye to be examined. And a high-order aberration correction unit. As a result, the low-order aberration correction unit can correct the diopter of the eye to be examined when correcting low-order aberrations having a large aberration amount among the aberrations of the eye to be examined. The acquisition unit 302 described later uses the diopter information included in the measured low-order aberrations to obtain an imaging range corresponding to the diopter of the eye to be examined (an imaging range affected by the diopter of the eye to be examined). The information shown can be acquired.

  Here, the diopter of the eye to be examined may be obtained by obtaining the result of measurement using a ring image of the fundus of the eye to be examined with a refractometer (eye refractive power measuring device) or the like. Further, the position where the focus lens is moved so that the contrast of the fundus image of the eye to be inspected captured by a wide-area SLO image or the like becomes a pointed contrast may be acquired as the diopter of the eye to be inspected. Note that when obtaining an actual imaging range (for example, a scanning angle at which the measurement light is actually scanned by the scanning unit), in addition to the diopter of the eye to be examined, the axial length of the eye to be examined is considered as a characteristic of the eye to be examined. Thus, it can be obtained with high accuracy.

  The light that has passed through the compensation optical system is guided to the scanning optical system 109-1, the eyepieces 110-1 and 110-2, and the scanning optical system 109, and is one-dimensionally or two-dimensionally by the scanning optical systems 109 and 109-1. Imaged. In this example, the scanning optical system 109-1 uses a resonance scanner (resonance mirror) that can scan at high speed but has a narrow scanning angle of view for main scanning.

  The scanning optical system 109 uses a galvano scanner (galvano mirror) for sub-scanning. The galvano scanner of the scanning optical system 109 supplements an area in which the main scanning resonance mirror of the scanning optical system 109-1 has an insufficient angle and cannot be imaged. By using the galvano scanner of the scanning optical system 109, it is possible to image a fundus region that cannot be captured by the scanning optical system 109-1.

  The measurement light imaged by the scanning optical system 109 irradiates the eye 111 through the eyepieces 110-3 and 110-4 and the dichroic mirror 130. The measurement light applied to the eye 111 is reflected or scattered by the fundus (retina). By adjusting the positions of the eyepieces 110-3 and 110-4, it is possible to perform optimal irradiation by adjusting the focus in accordance with the diopter of the eye 111 to be examined.

  Reflected and scattered light from the fundus (retina) of the eye 111 to be examined travels in the opposite direction on the same optical path as when light enters from the adaptive optics, and is partially reflected by the light dividing unit 106 in the optical path. It is guided to the sensor 115 (wavefront measuring unit). The wavefront sensor 115 (wavefront measuring unit) measures the wavefront of the guided light beam.

  A part of the reflected and scattered light transmitted through the light splitting unit 106 is reflected by the light splitting unit 104 and guided to the light intensity sensor 114 through the collimator 112 and the optical fiber 113. The light intensity sensor 114 converts the guided light into an electrical signal, and the image processing unit 305 generates a fundus image based on the electrical signal converted by the light intensity sensor 114. The image processing unit 305 can generate an entire fundus image of the designated imaging range from images captured for a plurality of partial areas.

  The wavefront sensor 115 is connected to the adaptive optics controller 118 and inputs the wavefront of the received light beam to the adaptive optics controller 118. The wavefront correction device 108 is also connected to the adaptive optics control unit 118, and the wavefront correction device 108 corrects the shape of the reflection surface in accordance with an instruction from the adaptive optics control unit 118.

  The adaptive optics control unit 118 calculates the wavefront aberration based on the wavefront acquired from the wavefront sensor 115 to obtain a wavefront shape that can be corrected to a wavefront free of wavefront aberration, and causes the wavefront correction device 108 to deform the wavefront shape. Instruct. The adaptive optics control unit 118 repeats the instruction to the wavefront correction device 108 according to the measurement result of the wavefront by the wavefront sensor 115, and performs feedback control so that the reflection surface of the wavefront correction device 108 has an optimal wavefront shape without wavefront aberration. Is done.

  The control computer 148 controls the adaptive optics control unit 118, the image processing unit 305, and an actuator such as an optical scanning system and an objective lens. The user interface of the control computer 148 includes an input unit (306 in FIG. 3A) that receives an instruction from the operator, and a display unit (307 in FIG. 3A) that displays a designation screen (for example, FIG. 4) for designating an imaging range. ). For example, the operator designates an imaging range from a designation screen displayed on the display unit 307, inputs an imaging range as numerical data from the input unit 306, and information (for example, diopter) indicating characteristics of the eye to be examined. It is possible to specify.

  An optical system including a laser light source 131 having a wavelength of 920 nm, an optical fiber 132, a collimator 133, a light splitting unit 134, a scanning optical system 139, eyepieces 140-1 and 140-2, a collimator 142, and a light intensity sensor 144 is a wide-field SLO. It is. Light from the wide-field optical system (optical unit) is reflected by the dichroic mirror 130 and irradiates the eye 111 to be examined. The light reflected from the fundus of the subject's eye 111 is reflected again by the dichroic mirror 130, travels in the optical path of the wide-field optical system in the direction opposite to the direction of incidence, and is partially reflected by the light dividing unit 134. , And is guided to the light intensity sensor 144 through the collimator 142. The light intensity sensor 144 converts the guided light into an electrical signal, and the image processing unit 305 generates a fundus image based on the electrical signal converted by the light intensity sensor 144. The wide-field optical system (optical unit) can be used to confirm the imaging target range to be imaged by the compensating optical system (compensating optical unit).

  An imaging apparatus having an adaptive optical system can acquire an image with high resolution by detecting and correcting the aberration of the eye to be examined using the adaptive optical system. However, the range that can be imaged with the wavefront corrected by the compensation optical system is narrow, and the range that can be imaged is about, for example, on the fundus, depending on the beam diameter, when trying to ensure resolution for observing photoreceptor cells. It is possible to image a portion limited to an imaging area of 350 μm square. The imaging area may be determined in advance, may be changed according to the scanning angle of the scanning optical system, or may be configured such that the operator can manually specify the scanning angle.

(Partial area within the specified imaging range)
FIG. 2 is a diagram illustrating a partial region for imaging the eye to be examined within the designated imaging range. In FIG. 2, the designated imaging range is a 900 μm square range, and the imaging range corresponding to the diopter is a 350 μm square range. In the present embodiment, a partial region for imaging the eye to be examined is determined within the designated imaging range. The determination of the partial area will be described in detail later.

  1 to 9 in FIG. 2 indicate the numbers of the determined partial areas. For example, imaging is performed for each partial area such as the partial areas 1, 2, 3,... In FIG. 2, and a fundus image of the entire area is generated from the image captured for each partial area. In the example of FIG. 2, as an example of a plurality of partial areas, a configuration including an overlapping area (a hatched area) where adjacent partial areas overlap is shown. The gist of the present invention is not limited to this example, and the image processing unit 305 uses the image for each partial area and the position of the partial area for the area not including the overlapping area. It is also possible to generate an entire image.

  As a joining region (overlapping region) in which adjacent partial regions overlap, in the example of FIG. 2, a region of 25 μm is included in the partial region. The size of the joining area can be designated from the input unit 306, for example. For example, when 25 μm is specified as the size of the joining region, 25 μm × 2 = 50 μm in the horizontal direction (lateral direction) and 25 μm × 2 = 50 μm in the vertical direction (vertical direction) are connected to each partial region. It is set as a matching area (overlapping area).

  When the size of the partial area is 350 μm square, the difference area (350 μm square−50 μm = 300 μm square) obtained by subtracting the joining area (50 μm square) does not overlap between the partial areas (effective area). It becomes. The center of the effective area (300 μm square) is set as the imaging center position. An image for each partial region is acquired by combining the imaging positions of the optical system for imaging the eye to be examined with the imaging center position as a reference.

  As an imaging procedure, first, when imaging the partial area 1 of FIG. 2, imaging of the resonance scanner (galvanomirror) of the scanning optical system 109-1 for the main scanning direction at the imaging center position of the divided partial area 1 is performed. Adjust the position. The wavefront of the guided light beam is measured by the wavefront sensor 115. The adaptive optics control unit 118 calculates a wavefront aberration based on the wavefront acquired from the wavefront sensor 115, calculates a wavefront shape for correcting the wavefront without the wavefront aberration, and outputs a shape deformation instruction to the wavefront correction device 108. To do. The wavefront correction device 108 corrects the shape of the reflection surface in accordance with an instruction from the adaptive optics control unit 118.

  After the shape of the reflecting surface is corrected by the wavefront correction device 108, the control computer 148 aligns the imaging position of the galvano scanner of the scanning optical system 109 for the sub-scanning direction with the imaging center position of the partial region 1. Then, the control computer 148 synchronizes the imaging by the resonance scanner of the scanning optical system 109 and the imaging by the galvano scanner of the scanning optical system 109. As a result of this synchronized imaging, the light reflected and scattered from the fundus of the eye 111 to be inspected travels along the optical path of the compensation optical system and is guided to the light intensity sensor 114 via the light splitting unit 104 and the collimator 112. The light intensity sensor 114 converts the guided light into an electrical signal, and the image processing unit 305 generates a fundus image of the partial region based on the electrical signal converted by the light intensity sensor 114. Then, the image processing unit 305 generates an entire image of the imaging range of the eye to be examined using the image of each partial region and the position of the partial region within the designated imaging range.

  In this example, the SLO using the adaptive optics system is exemplarily described. However, the present invention is not limited to the SLO, and can be similarly applied to the OCT.

(First embodiment: acquisition and connection of images for each partial region)
FIG. 3A is a diagram illustrating a functional configuration of the imaging apparatus 300 according to the embodiment of the present invention. The designation unit 301 functions as a user interface for the control computer 148. The designation unit 301 receives an instruction from the operator, and a display unit that displays a designation screen for confirming and designating the imaging range (for example, a wide-field electronic image of the eye to be examined in FIG. 4). 307.

  For example, the operator can input an imaging range numerically from the input unit 306 of the specifying unit 301, or can specify information (for example, diopter value) indicating the characteristics of the eye to be examined. Here, the characteristic of the eye to be examined is, for example, the diopter of the eye to be examined.

  Note that when determining the actual imaging range, the diopter of the eye to be examined must be taken into account, for example, when the focus lens is disposed between the galvanometer mirror and the eye to be examined as shown in FIG. is there. In this case, when the focus lens is moved to correct the diopter of the eye to be examined, the scanning range of the measurement light scanned by the galvanometer mirror is changed. For this reason, the actual imaging range is different from the designated imaging range. That is, the designated imaging range and the actual imaging range do not match due to the effect of the diopter of the eye to be examined, and even if the focus lens is moved to correct the diopter of the eye to be examined, it does not match. For this reason, in order to make the designated imaging range coincide with the actual imaging range, for example, it is necessary to adjust the scanning angle of the galvanometer mirror according to the diopter of the eye to be examined.

  In addition, the focus lens may be disposed between the galvanometer mirror and the light source. In this case, even if the focus lens is moved to correct the diopter of the eye to be examined, the scanning range of the measurement light scanned by the galvanometer mirror is not changed. That is, the designated imaging range and the actual imaging range match even if the focus lens is moved to correct the diopter of the eye to be examined. For this reason, if the measurement light is scanned at the designated scanning angle by the galvanometer mirror, it is possible to take an image within the designated imaging range. When the axial length of the eye to be examined does not match the set value (for example, the average axial length of 23 mm) set in the apparatus, the actual imaging range (for example, scanning in which the measurement light is actually scanned by the scanning unit) When obtaining (angle), it is necessary to consider the axial length of the eye to be examined as a characteristic of the eye to be examined. In general, when the beam diameter of the measurement light is large, the device in which the focus lens is arranged between the galvanometer mirror and the light source is compared with the device in which the focus lens is arranged between the galvanometer mirror and the eye to be examined. And get bigger.

  The characteristic of the eye to be examined may be the axial length of the eye to be examined. For example, when the eye to be examined is intense myopia, since the eye axis length of the eye to be examined is long, the scanning range in which the measurement light is scanned by the galvanometer mirror is larger than the designated scanning range. For this reason, the actual imaging range becomes larger than the designated imaging range. For this reason, it is preferable to consider the axial length when determining the actual imaging range. Further, the information indicating the axial length may be acquired from an external device, and the size of the imaging range corresponding to the diopter to be described later may be determined based on the acquired information indicating the axial length.

  In addition to the axial length of the eye to be examined, the characteristics of the eye to be examined may be the refractive index of the cornea of the eye to be examined, the depth of the anterior chamber of the eye to be examined, or the like. For example, it is preferable to store the values of these parameters and the scanning angle of the galvano mirror in the storage unit for each designated imaging range in association with each other. In this case, for example, if the designated imaging range and the axial length are given, the scanning angle of the galvanometer mirror is determined. Of course, a combination of these parameters may be used as the characteristics of the eye to be inspected. In this case, for example, it is conceivable to store a conversion equation for obtaining the scanning angle of the galvanometer mirror using these parameters in the storage unit. .

  Further, the operator can specify the size of the joining area (overlapping area), which is an area where the partial areas overlap, from the input unit 306 of the specifying unit 301.

  The moving unit 308 moves the optical element (the eyepiece lens 110-4) constituting the optical system in order to adjust the focus of the optical system with respect to the eye to be examined. The storage unit 310 functions as a database that stores diopter and an imaging range corresponding to the diopter.

  The acquisition unit 302 acquires information indicating an imaging range corresponding to the diopter of the eye to be examined. For example, the acquisition unit 302 can acquire an imaging range corresponding to the diopter by a calculation process using the position of the optical element moved by the moving unit 308 and the imaging magnification of the optical system. In addition, information indicating the imaging range can be acquired with reference to information stored in the storage unit 310 in advance, regardless of the arithmetic processing. For example, the acquisition unit 302 refers to the table of the storage unit 310 using the specified diopter as key information, and searches for information indicating an imaging range corresponding to the specified diopter. When range information (imaging range information) corresponding to the designated diopter is stored in the table, the acquisition unit 302 acquires information indicating the imaging range according to the diopter by reading from the table of the storage unit 310. can do.

  The acquisition unit 302 can be connected to an external device 350 (including an external server and a table) via the network 380. The acquisition unit 302 can acquire information indicating the imaging range corresponding to the diopter via the network 380 by the arithmetic processing executed by the external device 350. In addition, the acquisition unit 302 can acquire information indicating an imaging range corresponding to the diopter from the table of the external device 350 via the network 380.

  The determination unit 303 uses the information indicating the imaging range corresponding to the diopter of the eye to be examined to determine the sizes of the plurality of partial areas and the positions of the plurality of partial areas for imaging the eye to be examined in the designated imaging range. decide. The determination unit 303 determines the size of the plurality of partial areas using information indicating the imaging range corresponding to the diopter of the eye to be examined and the size of the predetermined partial area, and determines the specified imaging range. The position of a plurality of partial areas is determined using the determined size. Further, the determination unit 303 divides the designated imaging range by the determined size to determine the positions of the plurality of partial areas. The determination unit 303 determines whether or not the imaging range corresponding to the diopter is within the imaging range designated by the operator of the imaging apparatus when imaging the eye to be examined. When the determination unit 303 determines that the image is within the specified imaging range, the image acquisition unit 304 acquires an image of the specified imaging range, and the image processing unit 305 acquires the image acquired by the image acquisition unit 304. Output as an overall image.

  The determination unit 303 compares the designated imaging range with information indicating the imaging range acquired by the acquisition unit 302. When determining that the designated imaging range exceeds the imaging range corresponding to the diopter, the determining unit 303 determines a plurality of partial areas for imaging the eye to be examined within the imaging range of the eye to be examined. The determination unit 303 uses the information on the imaging range of the eye to be examined and the information indicating the imaging range according to the diopter, and the size and the imaging of the plurality of partial areas for imaging the eye to be examined within the imaging range of the eye to be examined. The position of the partial area within the range is determined. This position becomes a reference position for imaging for each partial area (imaging center position).

  In order to acquire an image for each partial region, the image acquisition unit 304 controls the moving unit 308 to focus the optical system (compensation optical system, scanning optical system 109, 109-1). The image acquisition unit 304 can also obtain the diopter by using position information of the eyepieces 110-3 and 4 that are focused. The acquisition unit 302 can acquire diopter from the image acquisition unit 304 and acquire information indicating an imaging range according to the diopter of the eye to be examined by referring to the arithmetic processing described above or the storage unit 310. .

  After focusing, the image acquisition unit 304 acquires an image for each partial region by aligning the imaging position of the optical system for imaging the eye to be examined with the position (imaging center position) for each partial region. Note that scanning of light by the scanning optical systems 109 and 109-1 is synonymous with “imaging”.

  The display control unit 320 displays the image for each partial area acquired by the image acquisition unit 304 on the display unit 307. The determination unit 330 determines whether or not to use the partial area image displayed on the display unit 307 under the control of the display control unit 320 to generate the entire image of the imaging range of the eye to be examined. The operator observes the image displayed on the display unit 307, and the determination unit 330 receives the operator's determination result via the input unit 306. The determination of the image is not limited to the case where the determination result obtained by the operator's observation is input via the input unit 306, but the feature amount of the image quality of the partial area (for example, the luminance and brightness of the subject in the partial area). It is also possible to determine the reference value as a threshold value. For example, when the feature amount of the image quality of the acquired partial area is equal to or larger than a reference threshold value, the determination unit 330 determines to use the image to generate the entire image of the imaging range of the eye to be examined. On the other hand, when the acquired feature amount of the image quality of the partial area is less than a reference threshold value, the determination unit 330 determines that the image is not used to generate the entire image of the imaging range of the eye to be examined.

  The image processing unit 305 generates an entire image of the imaging range of the eye to be examined using the image for each partial area and the position of the partial area. When the joining area (overlapping area) is designated, the image processing unit 305 joins the images of the partial areas adjacent to each other in the overlapping area, and generates an entire image of the imaging range of the eye to be examined. The display control unit 320 displays the entire image generated by the image processing unit 305 on the display unit 307.

  Next, an imaging method by the imaging apparatus according to the present embodiment will be described using the flowchart of FIG. 3B. The image pickup apparatus will be described as having the SLO configuration having the adaptive optical system described with reference to FIG. 1, but the same image pickup method can be applied to OCT as described above.

  In step S101, the designation unit 301 designates an imaging range in accordance with an input from the operator. The imaging range may be designated by numerical values for the length and width, and the imaging range is graphically determined from the image (wide field electronic image) of the designation screen for designating the imaging range of the eye to be examined as shown in FIG. It is also possible to set. In addition to the manual input by the operator, a predetermined imaging range may be automatically designated by using some signal as a trigger.

  In step S102, the image acquisition unit 304 drives the wavefront correction device 108 according to the input to the wavefront sensor 115 to correct the wavefront aberration, and drives the eyepieces 110-3 and 4 to adjust the focus. If the wavefront is approximated by the Zernike coefficient obtained by measurement of the wavefront sensor 115 and the focus is adjusted, the focus can be adjusted with higher accuracy.

  In step S103, the designation unit 301 acquires diopter as information indicating the characteristics of the eye to be examined. In step S104, the determination unit 303 is specified as the sizes of a plurality of partial areas for imaging the eye to be examined within the imaging range, using the imaging range specified in step S101 and the diopter acquired in step S103. The position of the partial area in the imaging range is determined. When the imaging range is designated from the wide-field electronic image in FIG. 4 in step S101, the designation unit 301 sets the imaging range to the vertical and horizontal lengths based on the imaging magnification corresponding to the diopter of the wide-field optical system. And the imaging range is designated by a numerical range. The determination unit 303 determines the sizes (sizes) of the plurality of partial areas and the positions of the plurality of partial areas from the division result using the width of the specified imaging range and the width of the imaging range corresponding to the diopter.

  FIG. 5 is a diagram illustrating a partial region when the imaging range (entire region) specified in step S101 is 1200 μm in length and 1600 μm in width in the case of an eye to be examined having a diopter minus 10D. When the diopter is minus 10D (−10D), the partial region is 397 μm square (FIG. 5). When the diopter is 0D, the partial area is 350 μm square.

  The acquisition unit 302 can acquire (calculate) the imaging range corresponding to the diopter from the imaging magnification of an optical system (compensation optical system, scanning optical system, eyepiece) for imaging the eye to be examined. Or the acquisition part 302 can also acquire the imaging range corresponding to a diopter with reference to the memory | storage part 310 which memorize | stores the imaging range according to a diopter and a diopter. FIG. 3C is a diagram illustrating data stored in the storage unit 310. The storage unit 310 stores a table for storing an imaging range corresponding to the diopter. When the diopter of the eye to be examined is designated, the acquisition unit 302 can acquire the corresponding imaging range by referring to the table in the storage unit 310.

  Assuming that the joining area (overlapping area) is 25 μm, the determination unit 303 subtracts the area obtained by subtracting the joining area (50 μm = 25 μm × 2) at both ends from the imaging range (397 μm square) in the case of diopter minus 10D. It is determined as an effective area (347 μm square) that does not overlap between them. When the joining area (overlapping area) is not specified and the diopter is minus 10D, the effective area is 397 μm square.

  The determination unit 303 determines four partial areas for covering the imaging range in the direction of the vertical width of 1200 μm of the imaging range from the division result (about 3.46) obtained by dividing the vertical width of 1200 μm by the effective area length of 347 μm. Further, the determination unit 303 determines five partial areas for covering the imaging range in the direction of the horizontal width of 1600 μm of the imaging range from the division result (about 4.61) obtained by dividing the horizontal width of 1600 μm by the effective area length of 347 μm.

  When the diopter is 0D, the effective area is 300 μm (= 350 μm−50 μm). The determination unit 303 determines four partial areas for covering the imaging range in the direction of the vertical width of 1200 μm of the shooting range from the division result (4.00) obtained by dividing the vertical width of the shooting range by 1200 μm by the effective area length of 300 μm. To do. Further, the determination unit 303 determines six partial areas for covering the imaging range in the direction of the horizontal width of 1600 μm of the imaging range from the division result (about 5.33) obtained by dividing the horizontal width of 1600 μm by the effective area length of 300 μm.

  In step S <b> 105, the determination unit 303 determines the size of each imaging region and the imaging center position that is a reference position for imaging for each partial region. In order to obtain the imaging center position of each imaging area, first, the determination unit 303 determines the size of each imaging area. It is assumed that the vertical length of the imaging range specified in step S101 is ly = 1200 μm and the horizontal length is lx = 1600 μm. From the calculation result of the determination unit 303 described above, the number of partial areas arranged in the vertical length direction is (Dy) = 4, and the number of partial areas arranged in the horizontal direction is (Dx) = 5. The determination unit 303 determines the width X in the horizontal direction and the width Y in the vertical direction of each partial region using the expressions (1) and (2).

Horizontal width X = lx ÷ Dx (1)
= 1600μm ÷ 5 = 320μm
Vertical width Y = ly ÷ Dy (2)
= 1200μm ÷ 4 = 300μm
The determination unit arranges the partial areas having the horizontal width X and the vertical width Y obtained by the expressions (1) and (2) in the designated imaging range, and sets the center position of each partial area to each partial area. Is determined as the imaging center position. FIG. 6 is a diagram illustrating the imaging center position of each partial region. (Sx1, Sy1),... (SxDx, Sy1), (Sx1, Sy2),... (Sx1, SyDy),... (SxDx, SyDy) are imaging center positions in the respective partial areas. Yes, this position is a reference position for imaging for each partial area.

  When the center position of the designated imaging range is set to (0, 0), the determination unit 303 determines the imaging center position (Sxi, Syj) in each partial area using the expressions (3) and (4). The imaging center position (Sxi, Syj) can specify the position of each partial area within the designated imaging range.

Sxi = − (lx ÷ 2) + (lx × ((2 × i) −1)) ÷ (2 × Dx)) (3)
Syj = − (ly ÷ 2) + (ly × ((2 × j) −1)) ÷ (2 × Dy)) (4)
(I = 1, 2,... Dx, j = 1, 2,... Dy)
In step S <b> 106, the image acquisition unit 304 acquires an image for each partial region by matching the imaging center position of each partial region with the imaging position of the optical system for imaging the eye to be examined. Just as the imaging range varies depending on the diopter of the eye to be examined, the imaging magnification of the optical system varies depending on the diopter. When the diopter is 0D, the size of the partial area is 350 μm square, and when the diopter is minus 10D, the size of the partial area is 397 μm square, so that the imaging magnification (M) of the diopter minus 10D with respect to the diopter 0D is M = 350 ÷ 397 = 0.8816.

  When the diopter is 0D, it is possible to capture the partial area with reference to the imaging center position of the partial area by applying the imaging magnification (M) to the scanning angle of the scanning optical system driven at the position of (Sxi, Syj) become. The image acquisition unit 304 captures the scanning optical system 109-1 for the main scanning direction and the scanning optical system 109 for the sub-scanning direction synchronized therewith at a predetermined scanning field angle with respect to the imaging center position of the partial region. Thus, an image of each partial area can be acquired.

  The image acquisition unit 304 can calculate the scanning angle of the scanning optical system by the following (5) to (8). The image acquisition unit 304 can obtain the value obtained by adding the joining region to the distances X and Y (distance between the imaging center positions) obtained in step S105, using the equations (5) and (6).

x direction: X + (2 × joining amount) (5)
y direction: Y + (2 × joining amount) (6)
A scanning angle when imaging is performed when the scanning optical system 109-1 for the main scanning direction and the scanning optical system 109 for the sub-scanning direction synchronized therewith have a diopter of 0D is Θ. When the imaging magnification is M, the image acquisition unit 304 sets the scanning angle Θx in the main scanning direction and the scanning angle Θy in the sub-scanning direction for imaging a 350 μm square at a diopter 0D to the values of the expressions (5) and (6). And can be obtained by equations (7) and (8).

Θx = Θ × (X + (2 × joining amount)) ÷ 350 μm × M (7)
Θy = Θ × (Y + (2 × joining amount)) ÷ 350 μm × M (8)
In step S <b> 107, the display control unit 320 displays the partial area image acquired in step S <b> 106 on the display unit 307.

  In step S108, the suitability of the image displayed in step S107 is determined. The determination unit 330 determines whether or not to use the partial region image displayed on the display unit 307 under the control of the display control unit 320 in step S107 to generate the entire image of the imaging range of the eye to be examined. . If the determination result of the operator or the image quality does not satisfy the threshold value that is the criterion of the feature amount, the determination unit 330 determines that the partial region image is not used to generate the entire image (S108-No), and the processing Is returned to step S101. In step S101, the imaging range is designated again, and the same processing is repeated thereafter. For example, when the operator determines that the displayed image is not appropriate, the imaging range can be corrected and the imaging range can be reset.

  On the other hand, if it is determined in step S108 that the operator's determination result or the image quality is equal to or higher than a threshold value that is a criterion for the feature amount, the determination unit 330 determines that the partial region image is used to generate the entire image. (S108-Yes), the process proceeds to step S109. In this step, the entire image of the imaging range of the eye to be examined is generated using only the partial region image determined to be appropriate for the generation of the entire image, except for the partial region image determined not to be appropriate for the generation of the entire image. Is possible.

  In step S109, the image acquisition unit 304 determines whether or not imaging of all the partial areas has been completed. If not completed (No in S109), the process returns to step S106, and the unimaged partial areas are selected. Take an image. If all imaging has been completed (S109-Yes), the process proceeds to step S110.

  In step S110, the image processing unit 305 generates an entire image of the imaging range of the eye to be inspected using the image for each partial area and the position of the partial area. When the joining area (overlapping area) is designated, the image processing unit 305 joins the images of the partial areas adjacent to each other in the overlapping area, and generates an entire image of the imaging range of the eye to be examined.

  For example, the image processing unit 305 identifies the position of each partial area in the imaging range from the position of the partial area (imaging center position), and an image of the partial area corresponding to the identified area. By arranging these, it is possible to generate an entire image. Alternatively, the image processing unit 305 uses the imaging center position (Sxi, Syj) and the number of partial areas (the number of partial areas in the vertical length direction (Dy) and the number of partial areas in the horizontal direction (Dx)). Thus, by arranging the images of the partial areas as shown in FIG. 6 within the imaging range, an entire image can be generated.

  In step S110, the display control unit 320 displays the entire image generated in step S110 on the display unit 307.

(Second Embodiment: Illustrative Specification of Imaging Range)
In the first embodiment, a rectangular range is designated as the imaging range (S101 in FIG. 3), a plurality of partial areas in the imaging range are determined, and an entire image is generated from images captured in each partial area. explained. The gist of the present invention is not limited to the case where the imaging range is designated by a rectangle. For example, as the range designation in step S101 in FIG. 3, as shown in FIG. 7, it is also possible to designate an imaging range such as a cruciform range where the designated areas intersect within a 1600 μm square. is there. In the imaging range of FIG. 7, when the diopter is minus 10D (−10D), it is divided into partial areas of 397 μm square.

  FIG. 8 is a diagram exemplifying designation of an imaging range where regions intersect in an oblique direction. It is also possible to specify an imaging range such as an X-shaped range in which the regions intersect in an oblique direction within a 1600 μm square. In the imaging range of FIG. 8, when the diopter is minus 10D (−10D), it is divided into partial areas of 397 μm square.

  When the imaging range is designated as shown in FIGS. 7 and 8, the processing from step S <b> 102 to step S <b> 110 in FIG. 3B is the same as that in the first embodiment as processing after designation of the imaging range. However, since the entire partial area overlaps in the intersecting partial areas, the partial areas may be imaged in either direction. When the imaging range is designated as shown in FIGS. 7 and 8, only the designated imaging range needs to be imaged in the 1600 μm square area, and the processing load from step S102 to step S110 in FIG. 3B is reduced. It becomes possible to do.

  According to each of the above embodiments, when the designated imaging range exceeds the imaging range according to the diopter, the partial area for imaging the eye to be examined is determined within the designated imaging range, and the image of the partial area is determined. It becomes possible to get. Alternatively, it is possible to prevent an unnecessary burden from being imposed on the subject by imaging an unnecessarily large range.

  The imaging device according to each of the above embodiments can also be applied to an endoscope device. For example, the endoscope apparatus includes an irradiation unit including a light source and an imaging device that is provided in an outer cylinder that can be inserted into a body cavity and images the inside of the body cavity with light from the light source of the irradiation unit.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (18)

A designation means for designating an imaging range of the eye to be examined;
Using information indicating the imaging range corresponding to the characteristics of the eye to be examined, the size of the plurality of partial areas and the position of the plurality of partial areas for imaging the eye to be examined in the designated imaging range are determined. A determination means;
An imaging apparatus comprising:   The determining means determines the size of the plurality of partial areas using information indicating the imaging range according to the characteristics of the eye to be examined and the size of a predetermined partial area, and the specified imaging range and the determination The imaging apparatus according to claim 1, wherein positions of the plurality of partial areas are determined using the measured size.   The imaging apparatus according to claim 1, wherein the determination unit determines the positions of the plurality of partial regions by dividing the designated imaging range by the determined size.   The image acquisition means for acquiring an image for each partial area by aligning an imaging position of an optical unit for imaging the eye to be examined with a position for each of the partial areas. 4. The imaging device according to any one of 3. The determining means determines a reference position for each of the plurality of partial areas for imaging with an optical unit for imaging the eye to be examined, using the size and position of the plurality of partial areas.
The imaging apparatus according to claim 4, wherein the image acquisition unit acquires an image for each of the plurality of partial areas by aligning an imaging position of the optical unit with the reference position.   6. The image processing device according to claim 1, further comprising image processing means for generating an entire image of the imaging range of the eye to be examined using the images for each of the plurality of partial areas and the positions of the plurality of partial areas. The imaging device according to any one of the above.   The said image processing means produces | generates the whole image of the imaging range of the said to-be-tested eye by connecting the image of the said adjacent partial area | region in the overlapping area | region where an adjacent partial area | region overlaps. Imaging device. Display control means for displaying an image for each of the plurality of partial areas on a display unit;
Determining means for determining whether to use for generating the entire image of the imaging range of the eye to be examined for each of the displayed images;
Image processing means for generating an entire image of the imaging range of the eye to be examined using the image determined to be used and the positions of the plurality of partial areas;
The imaging apparatus according to claim 1, further comprising: Moving means for moving an optical element constituting the optical unit in order to adjust the focus of the optical unit for imaging the eye to be examined with respect to the eye to be examined;
An acquisition unit that acquires information indicating an imaging range according to the characteristics by a calculation process using the position of the optical element moved by the moving unit and the imaging magnification of the optical unit;
The imaging apparatus according to claim 1, further comprising: Storage means for storing a diopter of the eye to be examined and an imaging range corresponding to the diopter;
An acquisition unit that acquires information indicating an imaging range corresponding to the diopter of the eye to be examined from the storage unit as information indicating an imaging range corresponding to the characteristic;
The imaging apparatus according to claim 1, further comprising:   9. The information processing apparatus according to claim 1, further comprising an acquisition unit that is connected to an external device via a network and acquires information indicating an imaging range corresponding to the characteristic from the external device. Imaging device. Wavefront aberration measuring means for measuring the wavefront aberration of the eye to be examined;
The acquisition means which acquires the information which shows the imaging range according to the diopter of the eye to be examined as the information which shows the imaging range according to the characteristic using the measured wavefront. The imaging device according to any one of 1 to 8.   The imaging apparatus according to claim 1, further comprising an acquisition unit configured to acquire information indicating an imaging range corresponding to the characteristic based on information indicating the characteristic of the eye to be examined. .   9. The apparatus according to claim 1, further comprising an acquisition unit configured to acquire information indicating an imaging range corresponding to the characteristic based on information indicating an axial length of the eye to be examined. Imaging device.   The imaging apparatus according to claim 1, wherein the plurality of partial areas include an overlapping area in which adjacent partial areas overlap each other.   16. The imaging apparatus according to claim 1, wherein the optical unit for imaging the eye to be inspected includes a compensation optical unit for correcting wavefront aberration.   The program for functioning a computer as each means of the imaging device of any one of Claims 1 thru | or 16. An imaging method for an imaging apparatus,
A designation step in which the designation unit of the imaging device designates an imaging range of the eye to be examined; and
The determination unit of the imaging apparatus uses the information indicating the imaging range corresponding to the characteristics of the eye to be examined, and uses the information indicating the imaging range to capture the eye to be examined in the designated imaging range and the plurality of parts. A determining step for determining the position of the region;
An imaging method characterized by comprising:

Images