Nystagmus analysis device, program, and analysis system

Abstract

To provide a nystagmus analysis device and a program capable of analyzing nystagmus of a subject with a high degree of precision, and to provide an analysis system using them.SOLUTION: A nystagmus analysis device includes: data acquisition means for acquiring waveform data showing changes over time in visual lines of a subject (corresponding to processing of step S101); and analysis means for analyzing the acquired waveform data and obtaining each occurrence timing of a plurality of times of nystagmus occurring in a predetermined period being an analysis object (corresponding to processing of steps S103-S106).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a nystagmus support device and program, and an analysis system using the same. [Background technology]

[0002] As people age, the ability to control balance declines, leading to increased incidence of unsteadiness and falls. It has been reported that there are as many as 150,000 cases of femoral neck fractures associated with unsteadiness and falls each year, which is one of the reasons for the increase in medical and nursing care costs. Humans have an organ in the inner ear that senses balance, called the vestibular system, and the body maintains balance based on signals transmitted from the left and right vestibular systems to the brain. Therefore, if there is some abnormality in the vestibular function and the left and right vestibular nerves are stimulated unevenly, the brain becomes confused and causes dizziness.

[0003] Nystagmus testing is known as one of the tests for dizziness. Patent Document 1 discloses an analysis system that performs nystagmus analysis using video of the subject's pupils and links the analysis to head position data measured in parallel with the video. The invention disclosed in Patent Document 1 can analyze eye angle and eye velocity by dividing them into horizontal, vertical, and rotational components. Patent Document 2 discloses a recording device that measures the head position and eye movement of a subject and records the measurement data from the moment the subject becomes aware of dizziness. The invention disclosed in Patent Document 2 can analyze the frequency of nystagmus, the number of nystagmus, and the maximum slow phase velocity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-18704 A [Patent Document 2] JP 2010-207532 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, eye movement is represented as sawtooth waveform data. Although nystagmus may occur at the timings when the waveform data reaches its extreme values, strictly speaking, nystagmus does not occur at all of the timings when the waveform data reaches its extreme values ​​because the data contains some noise. The inventions disclosed in the above-mentioned patent documents analyze eye movement without taking into account the above-mentioned findings, and therefore cannot analyze nystagmus with high accuracy.

[0006] In view of the above problems, the present invention can provide a nystagmus support device and a program that can analyze the nystagmus of a subject with high accuracy. Furthermore, the present invention can provide an analysis system that uses the nystagmus support device and the program. [Means for solving the problem]

[0007] According to the present invention, there is provided a nystagmus analysis device comprising: a data acquisition means for acquiring waveform data representing changes in a subject's gaze over time; and an analysis means for analyzing the acquired waveform data to determine the occurrence timing of each of a number of nystagmus events that occurred within a specified period to be analyzed.

[0008] Furthermore, according to the present invention, there is provided a program for causing a computer to execute a data acquisition process for acquiring waveform data representing changes in the subject's gaze over time, and an analysis process for analyzing the acquired waveform data to determine the occurrence timing of each of a number of occurrences of nystagmus that occurred within a specified period to be analyzed.

[0009] Furthermore, according to the present invention, there is provided an analysis system comprising gaze measuring means for measuring the gaze of a subject, head position measuring means for measuring the head position of the subject, recording means for recording changes in the gaze and head position of the subject over time, and analysis means for analyzing the data recorded by the recording means and outputting an analysis result relating to the equilibrium function of the subject, wherein the analysis means outputs at least the occurrence timing of each of a plurality of nystagmus events that occurred within a specified period to be analyzed as the analysis result. Effect of the Invention

[0010] According to the above invention, the waveform data representing changes in the subject's line of sight is analyzed to determine the occurrence timing of each of a number of nystagmus events that occurred within a specified period to be analyzed, thereby making it possible to analyze the subject's nystagmus with high accuracy.

[0011] According to the present invention, there are provided a nystagmus support device and a program capable of analyzing the nystagmus of a subject with high accuracy. Furthermore, the present invention provides an analysis system using the nystagmus support device and the program. [Brief description of the drawings]

[0012] [Figure 1] This is a diagram depicting a subject wearing a VR device. [Diagram 2] 1 is a configuration diagram of an analysis system according to the present invention. [Diagram 3] 4 is a flowchart showing a processing procedure of nystagmus analysis according to the present invention. [Figure 4] FIG. 11 is a diagram showing waveform data after each process is performed. [Diagram 5] FIG. 11 is a diagram showing waveform data after each process is performed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0014] <Configuration of the analysis system according to the present invention> First, the configuration of the analysis system according to the present invention will be described. The present invention is a system for analyzing the equilibrium function of a subject.

[0015] FIG. 1 is a diagram illustrating a subject wearing a VR device 100. When carrying out the present invention, a VR device 100 is worn on the head of a subject, as shown in Fig. 1. The VR device 100 is a device that allows the wearer to experience a virtual reality environment, and is a so-called head-mounted display in which the area in front of both eyes of the wearer is covered with a display when worn on the head. The VR device 100 displays moving images for testing the balance function of the subject, records changes in the line of sight and head position during the display, and collects the respective measurement data.

[0016] FIG. 2 is a configuration diagram of an analysis system according to the present invention. As shown in FIG. 2, the VR device 100 includes a display unit 110, a gaze measuring unit 120, and a head position measuring unit . The display means 110 displays a moving image for testing the equilibrium function of the subject, and allows the subject to view the moving image. The display means 110 can be realized by a liquid crystal display device or the like. The gaze measurement means 120 measures the gaze of the subject viewing a moving image for testing the subject's balance function. The gaze measurement means 120 can be realized by an eye tracker (a sensor that detects the subject's gaze), etc. The gaze of the subject measured by the gaze measurement means 120 includes the rotation axis and rotation angle of the subject's eyeball, as well as the position of the subject's gaze (the position at which the subject is gazing). The head position measuring means 130 measures the head position of the subject viewing a moving image for testing the balance function of the subject. The head position measuring means 130 can be realized by a gyro sensor (a sensor that detects angular velocity) or the like.

[0017] As shown in FIG. 2, the VR device 100 is communicatively connected to the storage device 200, and the storage device 200 stores data measured by the VR device 100 (data showing changes in the subject's line of sight and head position over time).

[0018] As shown in FIG. 2, a computer device 300 is communicatively connected to a storage device 200 . The computer device 300 includes a display means 310 implemented by a liquid crystal display device or the like. The computer device 300 also includes an information processing device such as a CPU (not shown) and a storage device such as a ROM or RAM (not shown), and implements a data acquisition means 320 and an analysis means 330 through cooperation between this hardware and the installed software.

[0019] The computer device 300 can read and analyze the measurement data stored in the storage device 200 and output the analysis results regarding the equilibrium function of the subject to a display means 310, and has a configuration corresponding to the nystagmus analysis device according to the present invention. The data acquisition means 320 acquires waveform data representing changes in the subject's line of sight over time. The analysis means 330 analyzes the acquired waveform data and determines the occurrence timing of each of a plurality of nystagmus events that occurred within a predetermined period to be analyzed.

[0020] In addition, in implementing the present invention, communication between the VR device 100, the storage device 200, and the computer device 300 may be wireless communication or wired communication, and may be directly connected to each other or indirectly connected via other devices not shown.

[0021] <Flow of nystagmus analysis according to the present invention> Next, the flow of nystagmus analysis according to the present invention will be described. FIG. 3 is a flowchart showing the processing procedure of the nystagmus analysis according to the present invention. 4 and 5 are diagrams showing waveform data after each process has been performed.

[0022] First, the computer device 300 (data acquiring means 320) acquires waveform data representing changes in the subject's line of sight over time from the storage device 200 (step S101).

[0023] 4(a) shows the waveform data acquired in step S101. The waveform data contains a large amount of noise, so in order to analyze the nystagmus with high accuracy, it is necessary to reduce the influence of the noise. In order to reduce the influence of noise, the computer device 300 according to this embodiment smoothes the waveform data acquired in step S101. Specifically, the computer device 300 plots the average value of a number of consecutive points (three points in this embodiment) in the waveform data acquired in step S101 (step S102).

[0024] FIG. 4(b) shows the waveform data smoothed in step S102. The computer device 300 according to the present embodiment picks up points showing extreme values ​​in the waveform data. Specifically, the computer device 300 multiplies the leading slope and trailing slope of the target timing as a reference, and if the result is a positive value, the computer device 300 omits the timing, and if the result is a negative value, the computer device 300 keeps the timing (step S103). The process in step S103 corresponds to the "first process" according to the present invention.

[0025] FIG. 4(c) shows waveform data indicating the timing picked up in step S103. The computer device 300 according to this embodiment executes a process of omitting adjacent points (extreme values ​​occurring within a time period sufficiently shorter than the occurrence time of the nystagmus) in the waveform data. Specifically, when the difference between an earlier timing and a later timing among the timings left in step S103 is equal to or less than a threshold value, the computer device 300 omits one timing and keeps the other timing (step S104). The process in step S104 corresponds to the "first second process" according to the present invention.

[0026] FIG. 5(a) shows the waveform data from which adjacent points have been removed in step S104. The computer device 300 according to the present embodiment picks up points showing extreme values ​​in the waveform data. Specifically, the computer device 300 multiplies the leading slope and trailing slope of the target timing as a reference, and if the result is a positive value, the computer device 300 omits the timing, and if the result is a negative value, the computer device 300 keeps the timing (step S105). The process in step S105 corresponds to the "second first process" according to the present invention.

[0027] FIG. 5(b) shows waveform data indicating the timing picked up in step S105. The computer device 300 according to the present embodiment executes a process of picking out points in the waveform data where the gradient of the fast phase (the later side in the time series) is greater than the gradient of the slow phase (the earlier side in the time series). In other words, since the definition of nystagmus indicates that the change in the subject's gaze is greater in the fast phase than in the slow phase, points that meet this definition are picked out. Specifically, the computer device 300 compares the front tilt and rear tilt based on the timing detected in step S105, and detects the timing when the absolute value of the rear tilt minus the absolute value of the front tilt is equal to or greater than a threshold value (step S106). The process in step S106 corresponds to the "second process" according to the present invention.

[0028] 5(c) shows waveform data indicating the timings picked up in step S106. Each of these timings is the nystagmus timing extracted by the present invention. In this embodiment, in order to improve the visibility of the timing of each nystagmus, the sign function is used to draw the nystagmus points at a position slightly away from each other in the Y-axis direction of the waveform data. The sign function is a function that returns 1 for positive numbers, -1 for negative numbers, and 0 for 0. Finally, the computer device 300 according to this embodiment outputs waveform data indicating the timing of the nystagmus picked up in step S106, that is, the waveform data shown in FIG. 5(c), to the display means 310 (step S107).

[0029] As described above, the computer device 300 (analysis means 330) according to this embodiment is configured to determine the occurrence timing of nystagmus by alternately executing a first process (steps S103 and S105) for detecting extreme values ​​and a second process (steps S104 and S106) for omitting a portion of the timing detected in the first process multiple times. In this way, the computer device 300 according to this embodiment can determine the occurrence timing of nystagmus with high accuracy by executing different aspects of the second process in two stages.

[0030] However, the above content is one specific example of implementing the present invention, and the present invention may be implemented in a manner in which the timing of the occurrence of nystagmus is determined by executing processes corresponding to the first process and the second process described above once each, or in a manner in which the timing of the occurrence of nystagmus is determined by executing processes corresponding to the first process and the second process described above three or more times each. Therefore, it can be said that the computer device 300 (analysis means 330) determines the occurrence timing of nystagmus by executing a first process (steps S103 and S105) for detecting the timing at which the waveform data reaches an extreme value, and a second process (steps S104 and S106) for omitting a portion of the timing detected by the first process.

[0031] <About the program according to the present invention> The program of the present invention, when installed in computer device 300, causes the computer device 300 to execute a data acquisition process (corresponding to the process of step S101 above) for acquiring waveform data showing changes in the subject's gaze over time, and an analysis process (corresponding to the processes of steps S103 to S106 above) for analyzing the acquired waveform data and determining the occurrence timing of each of multiple nystagmuses that occurred within a specified period to be analyzed. This makes it possible to realize a program that can analyze the subject's nystagmus with high accuracy.

[0032] <Modification> The above-described embodiment of the present invention can be modified in various ways within the scope of the object and achievement of the present invention.

[0033] The present invention is not limited to being implemented by the system configuration shown in FIG. 2, and other configurations may be adopted. For example, while storage device 200 is illustrated in FIG. 2 as being external to computing device 300 , a corresponding component may be internal to computing device 300 . Also, in FIG. 2, one VR device 100 is illustrated for one computer device 300, but either or both may be realized by multiple devices. 2, the waveform data showing the subject's line of sight is acquired by the VR device 100, but the waveform data may be acquired by another device. For example, the waveform data may be acquired by analyzing an image of the subject's eyeball captured by a camera (not shown) and generating something equivalent to the above-mentioned waveform data.

[0034] The processing procedure described based on FIG. 3 is one specific example of implementing the present invention, and modifications may be made, such as rearranging the order of processing, omitting some processing, or adding processing not described in the above embodiment, within the scope of achieving the object of the present invention.

[0035] The present embodiment encompasses the following technical ideas. (1) A nystagmus analysis device comprising: a data acquisition means for acquiring waveform data representing changes in a subject's gaze over time; and an analysis means for analyzing the acquired waveform data to determine the occurrence timing of each of a number of nystagmus events that occurred within a specified period to be analyzed. (2) The nystagmus analysis device described in (1) in which the analysis means executes a first process for detecting the timing at which the waveform data reaches an extreme value and a second process for omitting a portion of the timing detected by the first process to determine the occurrence timing of the nystagmus. (3) The nystagmus analyzer according to (2), wherein the analysis means executes the first process and the second process alternately multiple times to determine the occurrence timing of the nystagmus. (4) The nystagmus analyzer according to (3), wherein the first second process is a process for omitting one timing and retaining the other timing when a difference between an earlier timing and a later timing among the timings detected by the first first process is equal to or less than a threshold value. (5) The second process of the second time is a process of comparing the front tilt and the rear tilt based on the timing detected by the second first process, and detecting the timing when the absolute value of the rear tilt minus the absolute value of the front tilt is equal to or greater than a threshold value. (6) The nystagmus analyzer according to (3), wherein both the first process and the second process are processes in which, when the value obtained by multiplying the front tilt and the rear tilt based on the target timing is positive, the timing is omitted, and when the value obtained is negative, the timing is retained. (7) A program for causing a computer to execute a data acquisition process for acquiring waveform data showing changes in the subject's gaze over time, and an analysis process for analyzing the acquired waveform data to determine the occurrence timing of each of multiple occurrences of nystagmus that occurred within a specified period to be analyzed. (8) An analysis system comprising: gaze measuring means for measuring the gaze of a subject; head position measuring means for measuring the head position of the subject; recording means for recording changes in the gaze and head position of the subject over time; and analysis means for analyzing the data recorded by the recording means and outputting an analysis result relating to the equilibrium function of the subject, wherein the analysis means outputs at least the occurrence timing of each of a plurality of nystagmus events that occur within a specified period to be analyzed as the analysis result. [Explanation of symbols]

[0036] 100 VR Devices 110 Display means 120 Eye Tracking Method 130 Head position measurement means 200 Storage device 300 Computer equipment 310 Display means 320 Data Acquisition Method 330 Analysis means

Claims

1. A data acquisition means for acquiring waveform data representing changes in the subject's gaze over time; an analysis means for analyzing the acquired waveform data and determining the occurrence timing of each of a plurality of nystagmus events that occurred within a predetermined period to be analyzed; A nystagmus analysis device comprising:

2. the analysis means executes a first process for detecting timings at which the waveform data reaches an extreme value, and a second process for omitting a part of the timings detected by the first process, thereby determining the occurrence timings of the nystagmus; The nystagmus analyzer according to claim 1 .

3. the analysis means executes the first process and the second process alternately a plurality of times to obtain a timing of occurrence of the nystagmus; The nystagmus analyzer according to claim 2.

4. the first second process is a process of omitting one of the timings detected by the first first process and retaining the other timing when a difference between an earlier timing and a later timing is equal to or smaller than a threshold value; The nystagmus analyzer according to claim 3.

5. The second process is a process of comparing the tilt of the front side with the tilt of the rear side based on the timing detected by the first process for the second time, and detecting the timing when the absolute value of the tilt of the front side subtracted from the absolute value of the tilt of the rear side is equal to or greater than a threshold value. The nystagmus analyzer according to claim 3.

6. In both the first process and the second process, when a positive value is obtained by multiplying a front gradient by a rear gradient based on a target timing, the target timing is omitted, and when a negative value is obtained, the target timing is retained. The nystagmus analyzer according to claim 3.

7. On the computer, a data acquisition process for acquiring waveform data representing changes in the subject's gaze over time; an analysis process for analyzing the acquired waveform data to determine the occurrence timing of each of a plurality of nystagmus events that occurred within a predetermined period to be analyzed; A program for executing the above.

8. A gaze measuring means for measuring the gaze of a subject; A head position measuring means for measuring a head position of the subject; A recording means for recording changes in the subject's line of sight and head position over time; an analysis means for analyzing the data recorded by the recording means and outputting an analysis result regarding the equilibrium function of the subject; Equipped with The analysis means outputs at least the occurrence timing of each of a plurality of nystagmus events that occurred within a predetermined period to be analyzed as the analysis result.

1. An analysis system comprising:

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