JPH0513659B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an eye movement feedback type indicator presentation device, and is particularly applicable to examinations in ophthalmology and neuropsychiatry, and visual psychological experiments in psychological engineering and image engineering. The present invention relates to an eye movement feedback type indicator presentation device.

[Prior art and problems to be solved by the invention] Conventionally, when an index is presented at a specific position within the retina and the visual characteristics at that point are to be determined, a fixation point is set and the subject is asked to He instructed them to fixate on that point and not move their eyes, and presented them with an indicator.

However, even when fixating on one point, the eyeballs move rapidly and minutely due to fixation micromovements.
Even if the subject fixates, the accuracy of the index presentation point deteriorates by the magnitude of this visual fixation micromovement. Furthermore, depending on the image presented, there is a problem in that incidental eye movements are induced, making it difficult to maintain fixation.

Therefore, the main object of the present invention is to provide an eye movement feedback type indicator presentation device that can continue to present an indicator at a precise point within the retina even when the above-mentioned eye movement occurs. That's true.

[Means for Solving the Problems] The present invention is an eye movement feedback type index presentation device that presents an index on the retina of the eyeball, and includes an index presentation means that presents an index image on the retina of the eyeball, and a light source on the eyeball. A fundus irradiation light source that irradiates the fundus, a fundus photography camera that photographs the reflected light from the eyeball, and an index image from the index presentation means and the light from the fundus irradiation light source that form an image on the fundus, and the image from the fundus is photographed. The camera is configured to include an optical system for forming an image on the camera, an eye movement detecting means for detecting the movement of the eyeball, and a servo control means for controlling the optical system according to the detection output of the eye movement detecting means.

[Operation] The eye movement feedback type indicator presentation device according to the present invention detects the eye movement of the subject and feeds back the rotation angle of the eye to the optical system, thereby presenting a stationary indicator despite the movement of the eye. do.

[Embodiment of the Invention] FIG. 1 is a schematic block diagram of an embodiment of the invention. Referring to FIG. 1, a fundus irradiation light source 1 irradiates the fundus of an eye 3 with infrared light via an optical system 2.
The fundus image reflected from the fundus is input to the fundus photographing camera 4 via the same optical system 2. The index to be presented to the subject is generated by the index presentation unit 5 and presented on the retina of the eye 3 via the optical system 2 as well. In order to detect eye movement, infrared light is irradiated from the eye movement detection infrared light source 6 to the cornea of the eye 3 via the optical system 7. The reflected light from the surface of the cornea is passed through an optical system 8 for eye movement detection to an eye movement detection unit 9.
is input. The eye movement detection section 9 detects the amount of movement of the eyeball and provides the detection output to the servo control section 10. The servo control unit 10 generates a control signal for driving the galvanometer 11 according to the detection signal, and drives the galvanometer 11. The galvanometer 11 controls the optical system 2.

By configuring as described above, even if the subject's eye movements occur, the index can be presented stationary at a pre-designated position on the retina, and a stationary fundus image can be photographed. There are various methods for detecting eye movement, and one of them, the corneal reflection method, will be explained later with reference to FIGS. 3 and 4.

FIG. 2 is a diagram showing a specific example of one embodiment of the present invention. Referring to FIG. 2, optical system 2 includes half mirrors 21 and 22, prisms 23 and 24, and a lens system 25. Light from the fundus irradiation light source 1 passes through a half mirror 21, is reflected by a half mirror 22, and is input to the fundus through prisms 23, 24 and a lens system 25. The index to be presented to the subject is generated by the index presentation unit 5, and is generated by the half mirrors 21, 2.
2 and is presented to a specified position on the retina through prisms 23 and 24 and a lens system 25.

In the example shown in FIG. 2, a CRT is used as the index presentation section 5, and the index is displayed on the CRT screen. Then, the fundus image of the presented index passes through the lens system 25, prisms 24 and 23, and the half mirror 22, and becomes an input image of the fundus photographing camera 4. The lens system 25 focuses the light from the fundus irradiation light source 1 on the fundus image, and also focuses the fundus image onto the fundus photographing camera 4. The directions of the prisms 23 and 24 are controlled by galvanometers 111 and 112. For example, prism 23 is used to cancel the horizontal rotational component of eye movement, and prism 24 is used to cancel the vertical rotational component.

The infrared light source 6 for detecting eye movement is, for example, an infrared light source.
An LED is used, and a virtual image of an infrared LED spot is formed on the corneal surface via a lens system 27. The combined image is focused on an area sensor 83 such as a video camera via a mirror 81 and a lens system 82 that constitute the optical system 8. The eye movement detection section 9 detects horizontal and vertical two-dimensional eye movement from the image output from the area sensor 83 according to a principle described later, and generates a control signal for the servo control section 10.

The servo control unit 10 controls the galvanometers 111 and 112 according to instructions from the eye movement detection unit 9. In this way, the prisms 23 and 24 are driven so as to cancel the eye movement, and as a result, the index presented to the subject remains stationary at the specified position on the retina even if the eye movement occurs. I can do it. Similarly, the incident light from the fundus irradiation light source 1 further enters the fundus surface from the front, and the fundus photography camera 4 can always capture a still image of the fundus even if eyeball movement occurs. On the fundus image,
An index on the retina can be photographed together with a fundus image, and the presentation position of the index can be determined while observing the subject's retina.

Eye movement detection methods include a method that irradiates the eye with weak infrared light and detects the difference between the light reflected from the black eye and the white of the eye, a method that detects the movement of a light spot imaged on the cornea, There are various methods, such as having a subject wear a contact lens with a built-in coil, and detecting eye movement from the induced electromotive force accompanying eye movement within a magnetic field.

FIGS. 3 and 4 are diagrams for explaining the principle of detecting eye movement. In FIGS. 3 and 4, a virtual image 33 is formed on the crystalline lens 31 using the infrared LED 12. Since the rotation center O of the eyeball and the rotation center O' of the crystalline lens 31 are different, the virtual image 33 moves in parallel as the eyeball rotates. This amount of parallel movement 34 corresponds to the rotation angle of the eyeball, and an area sensor 83 such as a video camera shown in FIG. 2 is used to photograph an image 33' of the virtual image 33 that has been moved in parallel as shown in FIG. It is detected by

FIGS. 5 and 6 are diagrams showing specific examples of the index presentation section shown in FIG. 2. The example shown in FIG. 5 is composed of an image processor, and is composed of an image generation section 51 that generates a presentation image, and a CRT display 52 that displays the output of this image generation section 51. Ru. As the CRT display 52, in addition to a small monitor, a small viewfinder used in a television camera may be used.

The example shown in FIG. 6 is an example using a laser light source or a point light source. The presentation image generation section 56 generates an image or index to be presented to the subject, and its output is given to the servo control section 57. The servo control section 57 generates signals for controlling galvanometers 58, 59 for horizontal and vertical deflection. Galvanometer 58,5
9 controls the mirrors 54 and 55 and the laser light source 5
The direction of travel of the laser beam from 3 is controlled to generate a desired presentation image.

By using the index presentation unit as described above,
The index can be presented stationary at a predetermined position on the retina despite the movement of the eyeball, and a clear still image of the fundus can be taken, and the position of the index on the retina can be confirmed on that image, allowing accurate presentation. You can specify the location.

[Effects of the Invention] As described above, according to the present invention, when presenting an index on the retina, the eye movement of the subject is captured,
By feeding back the movement, it is possible to present a stationary index despite the movement of the eyeball. Further, it is an object of the present invention to provide an eye movement feedback type index presentation device that can determine the presentation position of the index from a stationary fundus image and is extremely useful in visual psychology fields such as applications in ophthalmology and elucidation of neural circuits in the retina. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of one embodiment of the present invention. FIG. 2 is a diagram showing an example of implementation of an embodiment of the present invention. FIGS. 3 and 4 are diagrams for explaining the principle of detecting eye movement. FIG. 5 and FIG. 6 are diagrams showing specific examples of the index presentation section. In the figure, 1 is a fundus irradiation light source, 2, 7, and 8 are optical systems, 3 is an eye, 4 is a camera for photographing the fundus, 5 is an index presentation unit, 6 is an infrared light source for eye movement detection, and 9 is eye movement detection. part, 10, 57 is a servo control part, 1
1, 58, 59, 111, 112 are galvanometers, 21, 22 are half mirrors, 23, 24 are prisms, 25, 27, 82 are lens systems, 51, 5
6 is a presentation image generation unit, 52 is a CRT display,
53 is a laser light source, 54 and 55 are mirrors, and 83 is an area sensor.

Claims (1)

[Scope of Claims] 1. An eye movement feedback type index presentation device that presents an index on the retina of the eyeball, comprising: index presentation means that presents an index image on the retina of the eyeball; fundus irradiation that irradiates light onto the eyeball. a light source; a fundus photographing camera that photographs reflected light from the eyeball; an index image from the index presenting means and light from the fundus irradiation light source are imaged on the fundus, and an image from the fundus is sent to the fundus photographic camera; an optical system for forming an image; an eye movement detection means for detecting the movement of the eyeball;
and an eye movement feedback type index presentation device, comprising a servo control means for controlling the optical system according to a detection output of the eye movement detection means.