JPH0547207B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pupillometer that can measure pupil area, pupil diameter, etc. even when there is eye movement. Various studies in psychology and VDT, which has been gaining interest in recent years
The present invention relates to an eye movement-permitting pupillometer suitable for use in research on visual fatigue caused by use.

[Prior art] In various studies in physiology and psychology, and studies on visual fatigue associated with VDT use,
There is a strong desire to measure changes in the pupil while working while freely moving the eyes. However, existing pupillometers divide the image taken by a TV camera into two parts at an appropriate slice level.
Since the pupil area or diameter is calculated using the converted data, if the eyeball moves during measurement, the monitor image changes, resulting in an error. Therefore, currently it is possible to measure only the pupillary reaction when the eyes are looking in a specified direction.

[Problems to be Solved by the Invention] The technical problem of the present invention is to eliminate the influence of the radius of curvature of the cornea, etc., which differs from person to person, and to eliminate the influence of the curvature radius of the cornea, etc., and to constantly photograph the eyeball from a certain direction, so that the eyeball movement is not affected. The object of the present invention is to provide an eye movement-permitting pupillometer that can accurately measure pupil area, pupil diameter, etc.

[Means for Solving the Problems] In order to solve the above problems, the eye movement permissive pupillometer of the present invention is provided with a galvanometer mirror that rotates according to the movement of the eyeball, and changes the real image of the eyeball to changes in the direction of the eyeball. A relay optical system that forms an image in a stationary state regardless of the position of the eye; a monitor that controls the swinging drive mechanism of the galvano mirror so as to always keep the light point of the reflected light at the origin of the screen; a pupillometer that is connected to the monitor and measures the detected pupil area and pupil diameter; It is constructed by having the following.

[Function] In the eye movement-permitting pupillometer having the above configuration, the direction of the eyeball is detected by the monitor, and the rotating mirror is controlled by the zero position method so as to maintain the light point of the corneal reflected light at the origin on the monitor. As a result, it is possible to eliminate the influence of the radius of curvature of the cornea, which differs for each individual, and to always photograph the eyeball from a fixed direction. Therefore, even when there is eye movement, the pupil area, diameter, etc. Can be measured accurately.

[Embodiment] FIG. 1 shows an embodiment of the eye movement permissive pupillometer of the present invention.

The inventors previously filed Japanese Patent Application No. 198376 (1983).
No. 63-54145) proposes an eye movement measurement device that measures eye movement with high precision. This measurement device is designed so that the pupil seen from the front is always displayed on the monitor no matter which direction the eye turns. By inputting the image into an existing pupillometer, the pupillary reaction can always be accurately measured from the front even when the eyes are moved freely.

The configuration is explained in detail based on the drawings.
In Figure 1, 1 is the eyeball of the subject to be measured, and 2 is a reference point set at a specific position on the subject's head. This is to compensate for the parallel movement of the eyeball.

The light source 4 irradiates the eyeball 1 with a beam of infrared light, and between the light source 4 and the dichroic mirror 5 disposed in front of the eyeball 1, there is a
From the light source 4 side, the beam splitter 7, an optical system having a pair of lenses 8 and 9, a galvano mirror 10, a spherical mirror 11, a galvano mirror 12 whose tilting is controlled together with the galvano mirror 10, and the spherical mirror A spherical mirror 13 facing opposite to 11 is disposed. Upper galvanometer mirror 1
0 and 12 can also be configured by a single galvanometer mirror that is rotatable around two orthogonal axes.

The dichroic mirror 5 disposed in front of the eyeball 1 allows visible light to pass through but reflects infrared light. Therefore, the infrared light from the light source 4 will illuminate the eyeball 1 through the relay optical system consisting of the above-mentioned lens and each mirror, but this is because a real image of the eyeball is created on the light source 4 side of the lens 8. It won't happen.

By tilting the gamba mirrors 10 and 12 by a predetermined amount around two axes or any one of the axes according to the movement of the eyeball, the real image of the eyeball created by the relay optical system can be adjusted to the direction of the eyeball 1. It can be kept stationary regardless of changes, and the eyeball 1 can always be illuminated from the front with infrared light.

The information input/output device 16, which is seen through the mirror 5 disposed in front of the eyeball 1 and the dichroic mirror 15 behind it, is used as an index during measurement, and the dichroic mirror 15 An image sensor (PSD: Position Sensitive Detector or CCD) for position correction of the eyeball 1 is placed in the direction of the reflected light.
This is realized by ) 18 is for measuring the reference point 2 fixed on the head and maintaining the position of the measuring device and the eyeball in a constant relationship. Further, on the optical axis split by the beam splitter 7, a monitor 20 composed of a PSD or CCD is arranged. This monitor 2
0 is a rocking drive mechanism (not shown) for the galvanometer mirrors 10 and 12 so that the reflected light spot of the eyeball is always maintained at the origin of the monitor screen 21 by the zero position method.
The galvanometer mirrors 10 and 12 are controlled to give necessary tilting movements. And the monitor 20 above
A pupillometer 22 is connected to the pupillometer 22, which measures the pupil area, pupil diameter, etc. based on the output thereof. As this pupillometer 22, an existing one can be used.

In the figure, reference numeral 25 indicates a measuring instrument bed on which the entire apparatus is placed and whose position can be adjusted vertically, longitudinally, and horizontally, and is controlled by the image sensor 18 to maintain the reference point 2 at the origin. (Zero-position method). However, if the subject's head is fixed using a tooth mold or the like, the position adjustment function can be omitted.

A measuring device having such a configuration measures a reference point 2 fixed on the head using a position correction image sensor 18, thereby maintaining the position of the measuring device and the eyeball in a constant relationship, and aligning the eyeballs with each other in parallel. The movement is compensated for, and in this state, a change in the orientation of the eyeball 1 is detected by the monitor 20, and the galvano mirrors 10 and 12 are tilted according to the output, so that infrared light is always directed to the eyeball 1 regardless of the orientation of the eyeball 1. It is designed to be able to project from the front, and measure pupil area, pupil diameter, etc. in that state.

More specifically, the light source 4 projects infrared light converged into a beam, but the monitor 20 placed on its optical axis ensures that the reflected light point of the eyeball 1 always aligns with the origin of the monitor. The galvano mirrors 10 and 12 are controlled so as to maintain the position. That is, in the monitor 20, control is performed to maintain the reflected light spot at the origin of the monitor using the zero position method. This method allows highly accurate control without being affected by nonlinearity on the screen of a monitor such as a PSD or CCD. In addition, especially by adopting the zero position method, it becomes possible to eliminate the influence of the radius of curvature of the cornea, etc., which differs for each individual, which has been a problem in conventional eye movement measurement methods. Furthermore, since it is possible to measure up to twice the rotation angle of the galvanometer mirror, it is possible to measure at a wide angle of eyeball rotation.

FIG. 2 is a diagram showing an example of measurement results obtained by the apparatus having the configuration shown in FIG.

Figure A shows accommodation, Figure B shows the left and right angles of the eye, Figure C shows the vertical angle, and Figure D shows the pupil area. Measurement time is 60 seconds. Subjects: -7D
After focusing on the indicator presented on the screen, the task is to search from left to right for the specified number from the random numbers displayed on the CRT placed in -2D. It can be seen that the pupil area changes suddenly when looking at nearby objects or turning the eyes from the right to the left.

[Effects of the Invention] According to the eye movement-permitting pupillometer of the present invention, by always photographing the eyeball from a fixed direction, it is possible to accurately measure the pupil area, pupil diameter, etc. even when there is eye movement. Furthermore, when measuring eye movements, it is not only possible to eliminate the effects of the radius of curvature of the cornea, which differs in each individual, but also to eliminate the effects of nonlinearity on the monitor screen. Furthermore, the influence of parallel movement of the eyeballs is eliminated, and as a result, it becomes possible to measure pupillary reactions with high precision.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of measurement results obtained by the apparatus having the configuration shown in FIG. 1... Eyeball, 10, 12... Galvanometer mirror,
20...Monitor, 22...Pupillometer.

Claims (1)

[Scope of Claims] 1. A relay optical system that includes a galvanometer mirror that rotates according to the movement of the eyeball and forms a real image of the eyeball in a stationary state regardless of changes in the orientation of the eyeball; The galvanometer mirror is placed on the optical axis that is optically coaxial with the infrared light that is irradiated from the front, and the galvano mirror swings so that the light point of the light reflected from the cornea of the eyeball is always kept at the origin of the screen using the zero position method. A pupillometer that allows eye movement, comprising: a monitor that controls a drive mechanism; and a pupillometer that is connected to the monitor and measures the detected pupil area and pupil diameter.