JPH04279143A - Eyeball motion inspector - Google Patents

Abstract

PURPOSE:To omit complicated work for distinguishing an eyeball motion from twinkling in a measurement data when the eyeball motion of a person to be inspected is measured with an eyeball motion inspector. CONSTITUTION:An eyeball motion detector 3 and a twinkling detector 4 are connected to a TV camera 2 for photographing eyeball motion of a person to be inspected so as to allow the inputting of an image signal from the TV camera 2 simultaneously. An eyeball motion analyzer 5 is connected to the output sides of the eyeball motion detector 3 and the twinkling detector 4 to determine a trace of the eyeball motion with the eyeball motion analyzer 5 under a removal of twinkling from an eyeball motion displacement signal inputted from the eyeball motion detector 3 and a twinkling signal inputted from the twinkling detector 4. The trace of the eyeball motion as measured with the eyeball motion analyzer 5 is displayed on an eyeball motion display device 6.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an eye movement testing device for observing, recording, and analyzing eye movements when a subject tracks a presented visual target with his or her eyes for medical diagnosis. More specifically, the present invention relates to an eye movement testing device capable of measuring eye movement by detecting blinks of a subject during eye movement measurement.

0002

2. Description of the Related Art A well-known method for recording eye movements is EOG (electro-oculogram).
raphy) and is also used clinically. This involves placing electrodes on the skin around the eyes and recording the potential difference that occurs as the eye moves. Furthermore, a method (PENG) has been disclosed in which eye movement is detected by utilizing the difference in light reflection characteristics between the cornea and sclera of infrared rays irradiated onto the eyeball.

[0003] Also, the present applicant previously filed a patent application in 1983-145.
In No. 425, a dark room is formed in front of the subject's eyes, and an optotype consisting of a cross-shaped visible light source for testing is built into goggles that are equipped with a head-mounted means. The test subject can follow the test by switching the lighting of the
We have proposed an "eye movement testing device" that can be used to observe, record, and analyze eye movements by irradiating the eyeballs with invisible infrared rays and outputting video signals of eye movements using an infrared detection television camera. Ta. Furthermore, the present applicant has disclosed in Japanese Patent Application No. 63-292930 that a light emitting diode,
We proposed an eye movement analysis device equipped with a visual target covering the entire eye movement test range using a liquid crystal, etc., and then used autofocus to focus the TV camera on the area near the iris of the moving eyeball. Equipment (patent application 1986-31)
9322), etc.

0004

[Problems to be Solved by the Invention] Needless to say, the conventional EOG method and PENG method described above have problems with these methods, such as the need for a dark room during the examination, the need to separately present an optotype, etc. The above-mentioned special award Sho 63-14542 by the present applicant solved the problem of not being able to test the rotational movement of the eyeballs.
In both the invention of No. 5 and the eye movement analysis devices successively proposed by the applicant thereafter, it is not possible to prevent the subject from blinking during eye movement measurement. Therefore, the recorded data will contain a mixture of eye movement deviation and blinking, and if the recorded data includes blinking, there is a possibility that it will be mistakenly determined as abnormal eye movement. Conventionally, there has been a problem in that a doctor or the like who judges the data has to distinguish between eye movement and blinking.

[0005] The present invention has been made in view of the above-mentioned points. When measuring eye movements, a device automatically detects eye blinks and measures the eye movements, so that a doctor or the like can judge the data. An object of the present invention is to provide an eye movement testing device that makes it possible to omit the troublesome work of distinguishing between eye movement and blinking.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the eye movement testing device of the present invention includes a television camera for photographing the eye movements of a subject, and an image signal received from the television camera. an eye movement detection device that processes and detects eye movements; an eye blink detection device that receives video signals from the television camera and detects blinks based on fluctuations in the video signals; and an eye movement displacement signal from the eye movement detection device and the blink detection device. It consists of an eye movement analysis device that obtains an eye movement trajectory with blinks removed from the eye blink signal, and an eye movement display device that displays the eye movement trajectory measured by the eye movement analysis device.

The blink detection device includes a video signal addition means for receiving a video signal from a television camera and adding video signals for a predetermined number of screens, and a video signal addition means for comparing whether the sum of the video signals is larger than a reference value. It is efficient to comprise means for comparing with a reference value, and an eyelid signal outputting means for outputting a blinking signal indicating the presence or absence of blinking as a result of the comparison to the eye movement analysis device.

[0008]

[Operation] When testing the eye movement of a subject using the eye movement testing device configured as described above, the television camera photographs the eye movement of the test subject and transmits the video signal of the eye movement to the eye movement detection device. output to the blink detection device. The eye movement detection device that receives the video signal of the eye movement measures the eye movement based on data (movement of the center of gravity of the pupil, etc.) obtained through image processing. On the other hand, a blink detection device that receives an eye movement video signal at the same time as the eye movement detection device detects blinks based on fluctuations in the video signal (changes in brightness level, changes in pupil area, etc.). The eye movement analysis device calculates an eye movement trajectory with blinks removed from the eye movement displacement signal obtained by the eye movement detection device and the blink signal from the eye blink detection device, and the obtained eye movement trajectory is displayed on the eye movement display device. will be displayed.

[0009] When detecting an eye blink with the above-mentioned eye blink detection device, the video signal addition means adds the video signals of a predetermined number of screens received from the television camera, and the comparison means compares the sum of the video signals with the reference value. By comparing whether it is larger or not, it is possible to easily and accurately detect the blink signal and output it to the eye movement analysis device. In other words, when the eyelids are open and the pupil is photographed, the added screen brightness level decreases because the pupil is dark, and conversely, when the pupil is hidden by blinking, the brightness level increases. By comparing the brightness level with an appropriate reference value, it is determined whether or not the user is blinking.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of a test subject's eye movement using the eye movement testing device of the present invention.
is a flowchart showing the operation of the system when examining eye movement using the device. 1 shows the subject's eyeball, which is in a state of tracking a presented optotype (not shown) for eye movement testing. The television camera 2 is equipped with an eyeball 1 that is illuminated using natural light, visible light, or invisible infrared rays.
It receives reflected light from the surface of the eye and outputs a video signal, and the video signal is simultaneously output to the eye movement detection device 3 and the blink detection device 4.

The eye movement detection device 3 receives the video signal from the television camera 2, sequentially scans the images, processes the images, and detects the movement of the pupil center of gravity coordinates, that is, the eye movement of the subject.
The detected eye movement deviation signal is output to the eye movement analysis device 5. On the other hand, the blink detection device 4
Blinks are detected as described later based on fluctuations in the video signal received from the television camera 2 at the same time as the eye movement testing device 3, and the blink signal is output to the eye movement analysis device 5.

The eye movement analysis device 5 measures an eye movement trajectory from which blinks have been removed using the eye movement deviation signal from the eye movement detection device 3 and the blink signal from the eye blink detection device 4, and calculates the measured eye movement trajectory. This signal is output to the eye movement display device 6. The eye movement display device 6 receives the eye movement trajectory signal from the eye movement analysis device 5, and displays the eye movement of the subject on a monitor display, a data printer, or the like.

Next, a case will be described in which the eye movement of a subject is examined using the apparatus of the present invention. First, a visual target such as a lit LED is presented to the subject, which is sequentially moved by switching the lights on for the subject to follow, and the movement of the subject's eyeball 1 is photographed using the television camera 2. . At this time, the video signal of the eye movement from the television camera 2 is output to the eye movement detection device 3 and the blink detection device 4, and the video signal is image-processed by the eye movement detection device 3 to determine the center of gravity of the pupil. While eye movements are detected by locometry,
The blink detection device 4 detects blinks based on fluctuations in the eyeball video signal.

Blink detection in the blink detection device 4 is performed as follows. FIG. 3 is a flowchart showing a procedure for detecting a subject's blink in the blink detection device 4. First, an optotype is presented to the subject and a video signal of the eyeball 1 is captured when the subject tracks the optotype (step 11).
). Then, the screen is scanned and the video signals are added (
Step 12), and the addition is performed until the sum of the video signals for one screen is obtained (Step 13). Next, it is compared and determined whether the added video signal is larger than a preset reference value (step 14). At this time, when the subject blinks and the pupil is hidden, the brightness level of the sum of the video signals increases, so this brightness level is compared with an appropriate reference value, and if it is higher than the reference value, the eyelids are blinked. On the other hand, when the pupil is photographed with the eyelids open without blinking, the brightness level decreases because the pupil is dark, and it is determined that the user is not blinking (step 16). In this way, the blink signal, which is a signal indicating that the eye is blinking and a signal indicating that the eye is not blinking, is output to the eye movement analysis device 5 (step 1
7), this is done until the eye movement measurement is completed (step 18).

The eye movement analysis device 5 removes blinks from the eye blink signal obtained by the eye blink detection device 4 as described above and the eye movement displacement signal obtained by the eye movement detection device 3 described above. A trajectory is obtained, and the eye movement trajectory signal is output to the eye movement display device 6, and the eye movement with blinks removed is displayed on the eye movement display device, regardless of whether the subject blinked during the test.

In the embodiment, the case where the summation of the video signals for comparison with the reference value in the blink detection device 4 is calculated for one screen was explained. Of course, it is also possible to compare with a predetermined reference value.

Furthermore, in the blink detection device of the embodiment, the presence or absence of blinking was detected by scanning the screen and summing the video signals and comparing the luminance level with that of a reference value. If there is no change in the amount of light entering the examinee's eyes during the test, the pupil size will remain approximately constant, and if the examinee blinks, the pupil will chip and become smaller.
It is also possible to detect the size of the pupil with the blink detection device 4 and determine whether or not the person is blinking based on the detected pupil size.

As described above, in the eye movement testing device of the present invention, regardless of the blink detection method, the eye movement detection device can be used in combination with the eye movement detection device and the eye blink signal can be used to detect the eye movement of the doctor or other examiner. can easily perform accurate eye movement measurements without any troublesome work.

[0020]

Effects of the Invention According to the eye movement testing device of the present invention as set forth in claim 1, when testing the eye movement of a subject, the test data can be determined based on the blink of the eye of the subject during measurement of the eye movement. This method eliminates the need for doctors and others to perform the troublesome work of distinguishing between eye movements and blinks from recorded data, making it possible to measure eye movements extremely easily and accurately.

According to the second aspect of the invention, the eye blink detection device incorporated in the eye movement testing device can easily and reliably detect eye blinks by comparing the addition sum of video signals of a predetermined number of screens with a reference value. can be detected, and accurate eye movement measurements can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an eye movement testing device that is an embodiment of the present invention;

FIG. 2 is a flowchart showing the operation of the system of the inspection device of the present invention;

FIG. 3 is a flowchart showing a procedure for detecting eye blinks in the eye blink detection device.

[Explanation of symbols]

1. Subject's eyeballs 2 TV camera 3 Eye movement detection device 4 Blink detection device 5 Eye movement analysis device 6 Eye movement display device

Claims (2)

[Claims] Claims 1: A television camera for photographing eye movements of a subject; an eye movement detection device for receiving and image-processing video signals from the television camera to detect eye movements; and an image from the television camera. an eye-blink detection device that receives a signal and detects eye-blinks based on the fluctuation thereof; an eye-movement analysis device that calculates an eye-movement trajectory with blinks removed from the eye-movement displacement signal from the eye-movement detection device and the blink signal from the eye-blink detection device; An eye movement testing device comprising: an eye movement display device that displays an eye movement trajectory measured by an eye movement analysis device. 2. The blink detection device compares the video signal addition means for receiving the video signal from the television camera and adding the video signals of a predetermined number of screens to see if the total sum of the video signals is larger than a reference value. 2. The eye movement testing device according to claim 1, comprising means for comparing with a reference value, and blink signal output means for outputting a blink signal indicating the presence or absence of blinking as a result of the comparison to the eye movement analysis device.