1. Field of the Invention
The present invention relates to an ophthalmologic imaging apparatus such as a fundus camera used in a group examination, an ophthalmological clinic, or the like, and to a control method for an ophthalmologic imaging apparatus.
2. Description of the Related Art
Hitherto, fundus imaging by a fundus camera has been widely used for a purpose of screening in a group examination or a diagnosis of ophthalmological diseases. In recent years, a method of recording fundus images as digital data has been commonly used in general. The imaged data is recorded in a portable recording medium, a hard disk drive of a PC, or the like.
In addition, in some cases, the fundus imaging is performed while a pupil of an eye to be inspected is dilated by using a mydriatic agent or the like, and in other cases, the fundus imaging is performed on a naturally dilated pupil without using a mydriatic agent or the like.
Types of imaging using a fundus camera include general color imaging, autofluorescence imaging (hereinafter referred to as FAF imaging) for imaging fundus autofluorescence, stereo imaging for acquiring a three-dimensional fundus image by utilizing parallax, and anterior imaging for imaging an iris or a pupil.
For instance, in fundus imaging in an ophthalmological clinic, the FAF imaging may be performed in addition to color imaging, so as to make a diagnosis on the eye to be inspected in a multilateral manner.
In this way, there are several types of imaging using a fundus camera. Therefore, a photographer may be confused about which fundus imaging should be performed or may forget to take a fundus image necessary for diagnosis. In addition, there is also a problem in that an imaging procedure becomes complicated.
In order to solve the above-mentioned problem, in Japanese Patent Application Laid-Open No. 2010-5073, there is disclosed a medical imaging apparatus in which an imaging sequence as the imaging procedure is registered in advance and displayed so that a photographer can easily know which fundus imaging should be performed in the imaging operation.
Using the fundus camera disclosed in Japanese Patent Application Laid-Open No. 2010-5073, a photographer can know which fundus imaging should be performed in the imaging operation, but this selection does not always consider imaging time.
For instance, it is supposed that the color imaging and the FAF imaging are performed on both eyes to be inspected without using a mydriatic agent.
In an imaging sequence display screen, there are displayed (No. 1, color imaging, right eye), (No. 2, color imaging, left eye), (No. 3, FAF imaging, right eye), (No. 4, FAF imaging, left eye), and the like. Therefore, it is possible to prevent omission of imaging. However, when imaging is performed in the order of (No. 1, color imaging, right eye), (No. 3, FAF imaging, right eye), (No. 2, color imaging, left eye), and (No. 4, FAF imaging, left eye), miosis occurs between (No. 1, color imaging, right eye) and (No. 3, FAF imaging, right eye), and hence it is necessary to wait until the eye to be inspected is dilated. The same is true between (No. 2, color imaging, left eye) and (No. 4, FAF imaging, left eye), and hence it is also necessary to wait until the eye to be inspected is dilated.
In this case, imaging efficiency may be lowered for the examiner, and imaging time may be prolonged for the person to be inspected.
Further, there is a problem in that it is necessary to manually perform alignment between the eye to be inspected and the fundus camera main body, focus adjustment to the fundus of the eye to be inspected, and the like, which is complicated for the examiner.
It is an object of the present invention to provide an ophthalmologic imaging apparatus capable of shortening imaging time and resolving a complicated operation for an examiner.
In order to achieve the above-mentioned object, an ophthalmologic imaging apparatus according to one aspect of the present invention includes: an illumination optical system configured to illuminate an eye to be inspected; an imaging optical system configured to observe and image the eye to be inspected through an objective lens and a focus lens; a focus index disposed in the illumination optical system so as to project light to a fundus of the eye to be inspected; a focus detection portion configured to detect a focus state from the focus index; a focus drive unit configured to drive the focus lens based on the focus detection portion; an alignment detection portion configured to detect a positional state between the eye to be inspected and the apparatus; an alignment drive unit configured to drive an alignment mechanism based on the alignment detection portion; a left and right eye detection unit including a left and right eye detection mechanism for determining whether the eye to be inspected is a left eye or a right eye; and a mydriatic state detection unit configured to detect a mydriatic state of the eye to be inspected. The ophthalmologic imaging apparatus is configured to image one of eyes a plurality of times and image left and right eyes. The mydriatic state detection unit switches an imaging sequence.
According to one embodiment of the present invention, it is possible to shorten the imaging time and resolve the complicated operation for the examiner. Therefore, it is possible to improve imaging efficiency for the examiner, and it is possible to reduce imaging load on the person to be inspected.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, embodiments of the present invention are described in detail with reference to the attached drawings.
The present invention is described in detail based on the illustrated embodiment.
The imaging portion C2 is configured to move in three-dimensional (XYZ) directions with respect to an eye to be inspected E by a drive portion including a pulse motor or the like disposed in the base unit C1. In addition, the imaging portion C2 can be moved in the XYZ directions by operation of a joy stick C3.
Next, an optical system constructing the imaging portion C2 of the fundus camera C is described with reference to
On an optical axis L1, there are disposed an observation light source 1 configured to emit fixed light from a halogen lamp or the like, a condenser lens 2, a filter 3 configured to transmit infrared light and to block visible light, an imaging light source 4 such as a strobe light, a lens 5, and a mirror 6. On an optical axis L2 in the direction of reflection by the mirror 6, there are arranged in order a ring stop 7 having a ring-like aperture, a relay lens 8, and a perforated mirror 9 having a center aperture.
In addition, on an optical axis L3 in the direction of reflection by the perforated mirror 9, there are disposed a dichroic mirror 24 and an objective lens 10 so as to be opposed to the eye to be inspected E. The dichroic mirror 24 can be inserted in or removed from the optical axis L3. Then, an imaging stop 11 is disposed in the aperture of the perforated mirror 9. Further, behind the imaging stop 11, there are arranged in order a focus lens 12 that moves on the optical axis L3 so as to adjust focus, an imaging lens 13, and a half mirror 100. Behind the half mirror 100, there is disposed an imaging element 14 for observing a moving image and for taking a still image. At the end of an optical axis L4 in the direction of reflection by the half mirror 100, there is disposed an internal fixation lamp 101.
Further, an output of the imaging element 14 is connected to an image processing portion 17, and an output of the image processing portion 17 is connected to a system control portion 18. The image processing portion 17 outputs an observed image imaged by the imaging element 14 to be displayed on a monitor 15.
Now, structures of optical systems for alignment and focus are described.
First, a structure of an anterior observation optical system for alignment is described.
On an optical axis L5 in the direction of reflection by the dichroic mirror 24, there is formed an anterior observation optical system for observing an anterior ocular segment, which includes a lens 61, a stop 62, a prism 63, a lens 64, and a two-dimensional imaging element 65 having sensitivity in an infrared region. Here, light entering the prism 63 is refracted and split by an upper half and by a lower half of the prism 63 oppositely in the left and right direction. Therefore, if a distance between the eye to be inspected E and the imaging portion C2 is longer than an appropriate operating distance, a position of an image formed by the lens 61 becomes closer to the lens 61 than the prism 63. Then, an upper half of the observed image is shifted to right while a lower half of the observed image is shifted to left. Using this anterior observation optical system, it is possible to observe the anterior ocular segment of the eye to be inspected E illuminated by an anterior observation light source 105 in an infrared wavelength region different from the wavelength passing through the filter 3 for blocking visible light, so as to detect the alignment state with the anterior ocular segment of the eye to be inspected E.
Next, a structure of an alignment index projection optical system is described.
On a front surface of the perforated mirror 9, there is disposed a light emitting end of a light guide 104a for guiding light beams from an LED light source 103a, and this light emitting end is an alignment index P1. The alignment index P1 is disposed away from the optical axis L3. In addition, at a symmetric position with respect to the alignment index P1 around the optical axis L3, there is disposed a light emitting end of a light guide 104b for guiding light beams from an LED light source 103b (not shown) having the same wavelength as the LED light source 103a. This light emitting end is an alignment index P2 constructing the alignment index projection optical system. Further, if the operating distance between the eye to be inspected E and the imaging portion C2 is appropriate, light beams from the light emitting ends of the light guide 104a and the light guide 104b are reflected by a corneal surface of the eye to be inspected E. Then, the index light beams become parallel and propagate the same optical path as a fundus reflection light beam of an illumination light beam, so as to form images on an image plane of the imaging element 14. Using the alignment index projection optical system described above, it is possible to detect a positional relationship between the alignment indexes so that an alignment state with a fundus Er of the eye to be inspected E can be detected.
Finally, a structure of a focus optical system is described.
Between the ring stop 7 and the relay lens 8 on the optical axis L2, there is disposed a focus index projecting portion 22. This focus index projecting portion 22 is disposed for projecting a split index on a pupil Ep of the eye to be inspected E. Further, the focus index projecting portion 22 and the focus lens 12 are configured to synchronously move in directions of the optical axis L2 and the optical axis L3 respectively by a focus lens drive portion 19 and a focus index drive portion 20 based on control by the system control portion 18. In this case, the focus index projecting portion 22 and the imaging element 14 have an optically conjugate relationship. Using this focus optical system, it is possible to detect a focus state of the fundus Er of the eye to be inspected E.
The structures of the alignment optical system and the focus optical system are described above. Next, operations thereof are described in more detail with reference to
Next,
When an automatic alignment is performed on the anterior ocular segment of the eye to be inspected E so as to achieve the state of
In addition, the focus index projecting portion 22 and the focus lens 12 synchronously move in the directions of the optical axis L2 and the optical axis L3, respectively, based on control by the system control portion 18. Thus, the imaging element 14 and the focus index projecting portion 22 have an optically conjugate relationship. Therefore, when the focus index projecting portion 22 is moved in the direction of the optical axis L2, the split indexes 22a and 22b are moved in the observed image on the imaging element 14, and the focus lens 12 is synchronously moved in the direction of the optical axis L3. In other words, by controlling the split indexes 22a and 22b to move on the imaging element 14 from the state of
Further, in the present invention, it is necessary to determine in advance whether the eye to be inspected as a subject to imaging and observation is the right eye or the left eye as described later. As a determination method, for example, it is possible to determine based on an image of the eye to be inspected under being observed, or an operator may input information of the eye from which the inspection should be started in advance so that the determination is made based on the input. The structure described above constructs a left and right eye detection unit for determining whether the eye to be inspected is the left or right eye in the present invention.
As described above, the fundus camera according to this embodiment can automatically perform all the operations from alignment through focusing by operations of the alignment and the focusing. In addition, it should be understood that imaging operation can be performed after detecting that the alignment operation and the focusing operation are finished. In other words, the examiner can perform automatic imaging using the fundus camera C by pressing an imaging start switch (not shown) in an operation input portion 21. Further, because the fundus camera C can move in the left and right direction (X direction), it is also possible to automatically switch the eye to be imaged. With this structure, this embodiment is described as an ophthalmologic imaging apparatus, which can automatically perform the alignment operation and the focus operation to the eye to be imaged so as to automatically perform the operation until imaging.
Next, a characteristic operation in this embodiment is described with reference to
Hitherto, as illustrated in the imaging sequence of
In this way, hitherto, after finishing imaging two times for one eye (the right eye in
In addition, after finishing the autofluorescence imaging of the right eye in Step 502, it is necessary to wait until the pupil of the person to be inspected is dilated for time Tb before starting the color imaging of the left eye in Step 504. During this waiting time, switching from the right eye to the left eye is performed in Step 503. Hitherto, because of simplification of alignment operation by the operator, the imaging sequence of
On the other hand, as illustrated in the imaging sequence of
That is, in this case, as an imaging sequence for shortening imaging time, there are employed (No. 1, color imaging, right eye), (No. 2, color imaging, left eye), (No. 3, FAF imaging, right eye), and (No. 4, FAF imaging, left eye).
After imaging in (No. 1, color imaging, right eye), imaging in (No. 2, color imaging, left eye) with little influence of miosis is performed. The miosis of the right eye due to the last imaging in (No. 1, color imaging, right eye) is ameliorated while the imaging in (No. 2, color imaging, left eye) is performed. Therefore, imaging in (No. 3, FAF imaging, right eye) is performed at a timing capable of imaging in the mydriatic state. Similarly, the miosis of the left eye due to the last imaging in (No. 2, color imaging, left eye) is ameliorated while the imaging in (No. 3, FAF imaging, right eye) is performed. Therefore, imaging in (No. 4, FAF imaging, left eye) is performed at a timing capable of imaging in the mydriatic state.
In this way, the imaging sequence of
The reason why the time of the imaging sequence can be shortened is described again in detail.
There is utilized the fact that the time until the pupil of the person to be inspected is dilated after imaging is shorter for the eye that is not imaged than for the eye that is imaged. In
Further, utilizing the time Ta′ until the pupil of the eye that is not imaged is dilated after the color imaging, the switching from the right eye to the left eye in Step 512 and the switching from the left eye to the right eye in Step 514 are performed.
As described above, because the time after color imaging of both eyes until the next imaging can be shortened, the time from start to finish of the imaging becomes shorter in the imaging sequence of
In addition, in the imaging sequence of
As described above, the ophthalmologic imaging apparatus according to this embodiment can reduce load on the person to be inspected because the imaging time can be shortened without requiring the operator to perform complicated operation.
Two imaging modes of the color imaging and the autofluorescence imaging are described in this embodiment, but also in three times of imaging for one eye in which a red-free imaging is combined to the above-mentioned two imaging modes, it is possible to shorten the time from start to finish of the imaging by the imaging sequence in which the other eye is imaged after imaging one eye.
As described above, when the imaging is performed without a mydriatic agent, miosis of the pupil of the person to be inspected occurs after color imaging of the right eye performed in Step 501, for example. However, when imaging is performed with a mydriatic agent, the time from start to finish of the imaging becomes shorter in the imaging sequence of
This is because that miosis of the pupil of the person to be inspected does not occur even after the color imaging of the right eye is performed in Step 501. Therefore, it is not necessary to secure the time Ta after performing the color imaging of the right eye in Step 501 until the pupil is dilated. Therefore, it is possible to promptly perform the autofluorescence imaging of the right eye in Step 502. Similarly, it is possible to promptly perform the autofluorescence imaging of the left eye in Step 505 after performing the color imaging of the left eye in Step 504.
In other words, because the time Ta and the time Tb until the pupil is dilated are not necessary in the imaging with a mydriatic agent, the time from start to finish of the imaging in the imaging sequence of
Next, a method of solving the above-mentioned problem in the imaging with a mydriatic agent is described.
After the color imaging of the right eye of
Next, an operation by the method described above is described.
When the photography start switch is pressed, the imaging sequence of
Further, the above-mentioned detection of the mydriatic state is performed by an imaging sequence performing unit that selects and performs the imaging sequence in accordance with a result of the detection by the mydriatic state detection unit. The imaging sequence performing unit is constructed by a module region in the system control portion 18. In other words, the module region in the system control portion 18 working as a determining unit images one of the left and right eyes to be inspected for a plurality of times and determines an imaging order for imaging the other eye, in accordance with the acquired information about a mydriatic state.
Further, various known comparing units can be used for the imaging sequence performing unit as long as it is possible to perform detection and comparison of the pupil diameter as described above.
In addition, as the method of solving the above-mentioned problem, the following method may be employed.
Specifically, whether or not a mydriatic agent is used is input to the operation input portion 21 in advance. For instance, there is a method in which the operation input portion 21 includes a mydriatic agent check switch or the like. First, when a mydriatic agent is not used, the mydriatic agent check switch is turned off (is not turned on) while the photography start switch is pressed, thereby performing the imaging sequence of
Further, it is preferred that the mydriatic agent check switch for checking whether or not a mydriatic agent has been used work as an imaging sequence input unit for selecting and performing the imaging sequence. Further, a form of the imaging sequence input unit is not limited to the above-mentioned check switch but may be constructed by a selection switch and an execution switch, without limiting to the embodiment.
By the method described above, it is possible to perform the imaging sequence in which the time from start to finish of the imaging becomes shortest depending on with or without a mydriatic agent. Therefore, the effect of reducing load on the person to be inspected can be increased.
As described above, the imaging sequence when imaging the left and right eyes to be inspected for a plurality of times by operating the focus unit and the alignment unit is preferably stored in advance in an imaging sequence storing unit disposed, for example, in the system control portion 18. In addition, it is preferred to store a plurality of the imaging sequences such as ones illustrated in
In the first embodiment, it is described that the time of the imaging sequence can be shortened in the two imaging modes of the color imaging and the autofluorescence imaging, for example.
In a second embodiment of the present invention, there is described a case where stereo imaging of both eyes to be inspected is performed on the same eye to be inspected.
As the stereo imaging by the ophthalmologic imaging apparatus, there are known a simultaneous three-dimensional imaging method in which left and right images used for a three-dimensional image are simultaneously acquired in a single imaging, and an imaging method in which left and right images used for a three-dimensional image are acquired by performing normal imaging two times while shifting in the left and right direction. In this embodiment, there is described a case of adopting the method of performing the normal imaging two times while shifting in the left and right direction. In addition, in this embodiment, the imaging performed two times while shifting in the left and right direction is referred to as right side imaging and left side imaging. Further, there is described a case where the imaging is performed without using a mydriatic agent for the left and right eyes in order to reduce load on the person to be inspected.
Hitherto, as illustrated in the imaging sequence of
In this way, hitherto, after finishing the stereo imaging two times for one eye (the right eye in
On the other hand, as illustrated in the imaging sequence of
Thus, when the imaging sequence of
The reason why the time of the imaging sequence can be shortened is the same as that in the first embodiment, and hence description thereof is omitted. However, the time that can be shortened is as follows.
First, instead of waiting for the time Ta until the pupil of the right eye is dilated after the right side imaging of the right eye is performed in Step 711 illustrated in the imaging sequence of
Further, utilizing the time Ta′ until the pupil of the eye that is not imaged is dilated after each imaging, the switching from the right eye to the left eye in Step 712 and the switching from the left eye to the right eye in Step 714 are performed.
As described above, the time from start to finish of the imaging can be shortened more in the imaging sequence of
In addition, it should be understood that the same effect as in the first embodiment can be obtained by using the method for solving the problem inherent in the use of a mydriatic agent as described above in the first embodiment.
Further, the present invention can also be realized by performing the following processing. That is, the processing involves supplying software (program) for realizing the functions of the above-mentioned embodiments to a system or an apparatus via a network or various storage media and causing a computer (or a CPU, an MPU, or the like) of the system or the apparatus to read and execute the program.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2013-109013, filed May 23, 2013, and Japanese Patent Application No. 2013-109014, filed May 23, 2013, which are hereby incorporated by reference herein in their entirety.
Number | Date | Country | Kind |
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2013-109013 | May 2013 | JP | national |
2013-109014 | May 2013 | JP | national |