JPS635726A - Eyeground examination apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ophthalmoscopy apparatus, and particularly to an ophthalmoscopy apparatus for observing and photographing a fundus image of an eye to be examined.

[Prior Art] Fundus examination devices for observing and photographing fundus images are conventionally known, but with this type of device, it is not possible to observe or photograph the entire area of the fundus at once. , it is necessary to set a fixation target to guide the examinee's line of sight, and to change the direction of the visual field of the examinee's eye to select the required part of the fundus.

Conventionally, a configuration is known in which a means for guiding the line of sight of the eye to be examined is provided in a main body of a measuring device such as a fundus camera, or in a part of a face support device for a patient to be examined. In particular, when a face support device is provided with a line-of-sight guidance means, a flexible arm or the like is protruded from a part of the support device, and a light-emitting part such as a miniature lamp is provided at the tip of the arm so that the subject can see this. The line of sight was guided by moving the free arm.

[Problems to be Solved by the Invention] However, in the conventional method as described above, the examiner focuses on the fundus while adjusting the delicate relative position of the fundus camera and the eye to be examined, and then moves the hand while maintaining that posture. I had to extend it wide and move the miniature lamp at the end of the flexible arm to guide the line of sight. Therefore, in the conventional method, the examiner has to continue performing delicate and troublesome manual control in an awkward posture, which poses a problem in that the examiner is highly fatigued.

In addition, in conventional devices, the distance between the eye-guiding means such as a small lamp and the subject is set to be very small, so if the gaze time is prolonged, the subject may experience physiological pain. there were.

In addition, conventional gaze guidance mechanisms have poor reproducibility when it becomes necessary to re-guide the gaze to a previously guided position, and cannot accurately reproduce the same part of the fundus at the same coordinates on a recording surface such as a film. There wasn't.

Therefore, images of the observed and photographed fundus are affected by distortion aberration of the optical system of the fundus camera, even of normal parts, and images with different magnifications are obtained even when examining the same coordinates on the fundus. There was a problem. Therefore, when determining the state of a lesion over time, in other words, it is difficult to judge whether a particular area is healing or worsening by arranging the fundus measurement results of a subject over time. .

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a fundus examination apparatus having an optical system for observing and photographing a fundus image of the eye to be examined, which is visible to the examinee. A configuration is adopted in which a fixation target is provided, the display position of the fixation target is controlled to move to guide the subject's line of sight, and a means is provided for recording display position information of the fixation target. .

[Function] According to the above configuration, since the display position of the fixation target can be recorded, the fixation target can be displayed at the same position when reexamination is necessary. By guiding the examinee's line of sight in the same direction, it is possible to observe and photograph a fundus image of the examinee's eye under the same examination conditions.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1(A) shows the configuration of an optical system of a fundus camera as a fundus examination apparatus employing the present invention. The fundus camera shown in FIG. 1 is a non-mydriatic type that uses infrared light when observing the eye to be examined and uses visible light when photographing.

- In FIG. 1(A), the symbol E is the eye to be examined, and the eye to be examined [II! Objective lens l directly facing the optical axis of E
is placed. The following optical elements are arranged on the optical axis behind the objective lens 1.

That is, what is indicated by the reference numeral 2 is a mirror with a hole for guiding illumination light from an illumination system, which will be described later, toward the eye E to be examined. A focusing lens 3a is located behind the perforated mirror 2.
A photographing system lens consisting of a fixed lens 3b and a fixed lens 3b is arranged.

A fundus image of the eye E to be examined is formed on a recording surface 4 of a film (or a photoelectric conversion element, etc.) by this photographic lens. Furthermore, the image to be formed on the recording surface 4 is formed on the movable mirror 2.
0. It is configured so that it can be observed using an observation optical system consisting of a field lens 29, a mirror 21, and an eyepiece 22.

On the other hand, illumination light during observation of the fundus image is generated by the lamp 6 as a light source. Further, illumination light during photographing is generated by a strobe tube 7. These light sources are arranged in series through a condenser lens 30.

Light from a lamp 6, such as a tungsten lamp, is converted into an infrared light beam through a filter R that passes light in the infrared region and blocks light in other regions.

The light from any of the above-mentioned light sources is incident on the mirror 23 via the condenser lens 9. The illumination light reflected by the mirror 23 passes through the ring slit 10 for passing the illumination light through the peripheral region of the iris of the eye E, and is introduced into the relay lens 11. The relay lens 11 is the above-mentioned perforated mirror 2.
As a result, the ring-shaped illumination light is incident on the eye E through the perforated mirror 2 and the objective lens 1.

On the other hand, the light reflected from the fundus once forms an intermediate image of the fundus with the objective lens 1, passes through the opening of the perforated mirror 2, and is placed at a position substantially conjugate with the movable mirror 20 by the photographic lens 3. A fundus image is formed on the field lens 29.

The infrared light flux from the field lens 29 is filtered by a filter 13 that reflects the light flux in the infrared region and passes the light flux in the visible region.
is reflected by the TV camera 1 by the relay lens 14.
The image is formed on the imaging surface of No. 5 and observed on a video monitor (not shown).

On the other hand, a fixation target 17 is provided at a position substantially conjugate with the fundus of the eye via a movable mirror 20, a field lens 29, and a relay lens 18. This fixation target 17 is visually recognized by the eye to be examined through the optical system during the examination, and guides the eye in a predetermined direction.

The fixation target is configured such that, for example, a pinhole is illuminated from the rear. When the fixation target is composed of a single display point, the fixation target 17 can be changed by moving the fixation target 17 in a plane perpendicular to the optical axis of the optical system.
Since the imaging point of the light beam guided from the to the fundus of the eye to be examined also moves, the line of sight of the eye to be examined E can be guided in a desired direction.

Further, when the fixation target is constituted by a display device consisting of a display element such as a light emitting diode or a liquid crystal as described later, the line of sight can be guided by controlling the display position of the display device.

The position of the fixation target 17 in FIG. 1A is linked to the imprint fixation target 17' by mechanical or electrical means. The fixation target 17' for imprinting is set by moving the fixation target 17, selecting the imaging area, and then moving the strobe tube 7.
When photographing the fundus by emitting light and flipping up the movable mirror 20, the image is recorded on a recording surface of 4° by the recording lens 3C. The recording surface 4° may be the same as the recording surface 4 for recording the fundus image.

FIG. 1(B) shows different embodiments of fixation targets for imprinting.

Figure 1 (B) is a perspective view of the main parts of the optical system.
, %, 17 indicates the fixation target, and 17p indicates the display position of the fixation target. In this embodiment, the fixation target 17' for imprinting is composed of an LED array. A fixation target 17' for imprinting shown here is illuminated by a predetermined LED element according to the movement of the display position of the display point 17p of the fixation target 17, and is projected onto the recording surface 4 via the mirror 3f and lens 3c. recorded in

According to the above configuration, the position of the fixation target for imprinting, which moves in conjunction with the actual fixation target, is recorded at a specific coordinate position on the recording surface 4''.

When performing a reexamination later, if the position of the fixation target 17 is determined by referring to the fixation target position recorded on the recording surface 4'', the line of sight of the eye to be examined can be guided in the same direction as during the previous examination. Fundus images can be observed and photographed under the same conditions using a conventional configuration.In this case, unlike conventional configurations, the fixation target is accurately reproduced at the position of the previous examination. Unfavorable phenomena such as magnification changes in fundus images that occur can be eliminated.

FIG. 2 shows a different embodiment of the invention.

The configuration shown in FIG. 2 is an example of a configuration in which a Tasoko image is recorded using a TV image recording device.

The basic configuration of the optical system in FIG. 2 is almost the same as that in FIG. 1, except that there is no infrared filter for the lamp 6 for observation and photography using visible light. Further, the fundus image output by the TV camera 15 is recorded on a magnetic recording device 15a using a magnetic disk device or the like.

In the embodiment shown in FIG. 2, the fixation target 17 and the fixation target 17' for imprinting are integrated. That is, fixation target 1
The light emitted from the mirror 7 is guided in the direction of the eye E through the half mirror 13d and is reflected in the direction of the projection lens 3a through the half mirror 13d.
It is guided to a predetermined position on the imaging surface of the TV camera 15 via the lens 13b.

With such a configuration, it is also possible to record the line of sight guidance direction of the eye to be examined, which can be used for re-examination.

FIG. 3 illustrates a further different embodiment.

In the configuration shown in FIG. 3, a fixation target 17 is provided between the relay lens 11 and the ring slit 10 inside the blind system. Furthermore, as a modified configuration of FIG. 3, the fixation target may be constructed from a display board in which display elements such as LEDs are arranged at predetermined positions in an optical path branched from the illumination optical path by a half mirror or the like.

The fixation target 17 is moved in the optical axis direction of the illumination system so as to maintain a nearly conjugate relationship with the fundus of the eye E in conjunction with the focus lens 3a so that the patient can see it no matter what the optical system settings are. be done. Further, the line of sight is guided by moving the fixation target 17 within a plane perpendicular to the optical axis of the illumination system.

The linkage between the fixation target 17 and the fixation target 17' for imprinting is as follows.
This is performed by detecting the position of the fixation target 17 in a plane perpendicular to the optical axis using an electrical method. As a position detection method, for example, a method of coupling a potentiometer to the fixation target 17 or a photo sensor or the like is used to detect the light emitting display position of the fixation target, and this detection signal is transmitted as shown in FIG.
It is conceivable to display the XY coordinates on the fixation target for imprinting using a processing system as shown in C).

In FIG. 1(C), symbols 100X and 100Y are analog signals that detect the display position of the fixation target 17 as two-dimensional coordinates in the X and Y directions, and these detection signals 100X and 100
Y is input to A/D converters 101X and 10IY, converted into digital signals, and sent to digital signal processing devices 102x and 102X.
Input to 02Y. Signal processing device 102X, 102Y
is a fixation target 1 composed of, for example, a two-dimensional LED array, etc.
The XY coordinate display (lighting) position of No. 7 is determined based on the A/D converted coordinate signal.

It is also conceivable to light up the light emitting part of the fixation target 17'' for imprinting, which is configured in the same way as the fixation target 17.Furthermore, the light from the light emitting point of the fixation target 17 can be directly transmitted to a light guide or the like. It is also possible to consider a method in which the magnetic flux is guided to the recording surface using

FIG. 3 shows a different configuration of the fixation target for imprinting, in which the fixation target 17' for imprinting is composed of a two-dimensional array of LED arrays, and the light from each light emitting part is transmitted through an optical fiber.
7a is used to illustrate the structure that leads to the recording surface 4'' for the fixation target.In addition, in the configuration shown in FIG. 3, since the inspection is performed using infrared light, an infrared A filter R is provided.

Even with such a configuration, the line of sight of the eye to be examined and
Information regarding the guided position can be recorded. In this embodiment, the fixation target 17 is visually recognized through the main optical system and the illumination system. Of course, when the strobe tube 7 is used to emit light during photographing, the fixation target must be removed from the optical path.

Next, FIG. 4 shows a further different embodiment.

The configuration in FIG. 4 is almost the same as that in FIG. 1, except that infrared light is not used, and observation is performed with the naked eye through the eyepiece 28 without using an imaging device. are different.

Although the position of the fixation target 17 is the same as that shown in FIG. 1, this embodiment exemplifies a different recording method for the position of the fixation target 17.

In this embodiment, the fixation target 17 does not have a single light emitting point, but is composed of a large number of light emitting elements such as LEDs arranged two-dimensionally, as in the case of FIG. Directs the line of sight by emitting light.

On the other hand, the fixation target 17' for imprinting has the same (or similar) light emitting element arrangement as the fixation target 17, and as in the case of FIG. is placed at a position conjugate to .

Fixation target 17 for line-of-sight guidance and fixation target 17 for imprinting
The linkage of degrees is performed by lighting up the light-emitting elements of the fixation target 17 and the light-emitting elements occupying the same coordinate position of the fixation target 17°. Which light emitting element of the fixation target 17 is caused to emit light is controlled using a joystick, a switch, etc. In this case, the fixation target 17, 17' may be lit using the same drive signal.

Further, FIGS. 5A and 5B show an embodiment in which a fixation target 17 is provided on the front surface of the fundus examination apparatus.

FIG. 5(A) shows the external appearance of the optical system of the fundus examination apparatus. In FIG. A fixation target group 30 is provided concentrically around this lens barrel l°.

This fixation target group is composed of a group of light emitting elements such as LEDs. The LEDs constituting the fixation target group are formed radially so as to divide the concentric circles of the fixation target group at predetermined angles.

FIG. 5(B) shows the cross-sectional structure of the fixation target group portion of FIG. 5(A) in this sixth embodiment.

The fixation target group portion on the front side of the fundus examination apparatus is composed of a three-layer structure. An LED element is fitted as a light source into a through hole provided at a predetermined position in the chassis 31 on the front surface of the fundus examination apparatus.

A fixation target plate 32 is provided on the chassis 31 in order to set an appropriate light emitting range for visual guidance. A plurality of openings (pinholes) 32a having a predetermined area are formed at positions corresponding to the respective LED elements of the fixation target plate 32.

Furthermore, a light-diffusing member 33 made of a milky-white acrylic plate or the like is fixed to the front surface of the fixation target plate by a method such as adhesive.

Control of the display position by turning on and off each LED element constituting the fixation target 17 is controlled by a switch SW provided on the side of the fundus examination device. The switch SW is not limited to the side of the device, but may be provided at any other position that is easy for the inspector to operate.

Here, a bush type switch is exemplified as the switch SW, but various types such as a rotary switch and an analog switch controlled by a joystick or the like can be used.

Further, in this embodiment, a display 17d consisting of a three-digit LCD element is provided directly above the switch SW, and the control position of the fixation target 17 by the switch SW can be displayed by this display.

In the above configuration, the examiner instructs the examinee to look at the fixation target group, and guides the examinee's line of sight by operating the switch SW as appropriate during the fundus examination, thereby achieving the desired goal of the examinee's eye. The area can be observed or photographed. At this time, the operator can easily guide the line of sight by simply operating a switch SW provided at hand.

Also, the control position of the fixation target 17 displayed on the display 17d, that is, 4! By recording the i-guidance position, the subject's line of sight can be guided so that the target area can be easily observed and photographed when the same area is reexamined.

In the above configuration, the fixation target group is constructed using LED light emitting elements, but display means other than light emitting elements may be used. Provide a brightly colored display board that can be easily rotated.
The rotation and movement of the 0 display board, which can also be moved to guide the line of sight, is performed by a drive means such as a motor, and this drive means may be controlled by the switch SW.

In any of the above embodiments, the distance between the fixation target 17 and the subject's eye is not too close and is set at an appropriate distance, so that the test can be easily performed in a short time without causing fatigue or pain for both the examiner and the subject. Tests can be carried out.

In all of the above embodiments, the fixation target 1 is fixed by optical means.
Although the configuration for recording the 7th position has been exemplified, for example, the 4th position
In the embodiment shown in the figure, it is also conceivable to form digital information regarding the line-of-sight guidance direction from the drive signal of the fixation target 17 and record this in a memory element, magnetic disk device, or the like.

[Effect] As is clear from the above, according to the present invention, in a fundus examination apparatus having an optical system for observing and photographing a fundus image of an eye to be examined, a plurality of fixation targets that are visible to the examinee can be fixed. The present invention adopts a configuration in which the subject's line of sight is guided by controlling the movement of the display position of the fixation target, and a means for recording the display position of the fixation target is provided. It is possible to obtain higher reproducibility of the gaze guidance position compared to the arm-type gaze guidance system, etc., and it is possible to provide an excellent fundus examination apparatus that is particularly suitable for cases where re-examinations are repeatedly performed.

[Brief explanation of the drawing]

1 to 5 show different embodiments of the fundus examination device of the present invention, FIG. 1(A) is an explanatory diagram showing the overall configuration of the device, and FIG. 1(B) is an optical system. Perspective view of Figure 1 (C
) is a block diagram of the processing system, FIGS. 2 to 4 are explanatory diagrams showing the overall configuration of the device, FIG. 5(A) is a perspective view of the front of the device, and FIG. 5(B) is a diagram of the front of the device. FIG. 1... Objective lens 1゛... Lens barrel 3... Imprinting lens 4.4゛... Recording surface 6... Lamp
7... Strobe tube 15... TV camera 17.17'... Fixation target 17a... Optical fiber Fig. 1 (C) Fig. 5 (B)

Claims (1)

[Claims] In an ophthalmoscopy device that has an optical system for observing and photographing fundus images of the subject's eye, a fixation target that is visible to the subject is provided, and the display position of this fixation target is moved and controlled. An ophthalmoscopy apparatus characterized by comprising means for guiding the line of sight and for recording display position information of the fixation target.