Cognitive function evaluation device and cognitive function evaluation system

Abstract

A cognitive function evaluation device includes a brain signal detection unit, a response motion detection unit, and a calculation unit. The brain signal detection unit detects a brain signal generated by the subject with respect to the stimulus. The response motion detection unit detects response motion of the subject with respect to the stimulus and outputs a response signal. The calculation unit detects an event-related potential and a motion preparation potential from the brain signal, calculates a response speed from the response signal, and evaluates the cognitive function on the basis of the event-related potential, the motion preparation potential, and the response signal.

Description

Technical Field

[0001] The invention relates to a cognitive function evaluation technology. Background Art

[0002] In Patent Document 1, dementia is identified using the waveform of electroencephalograms in response to visual stimulation, auditory stimulation, and olfactory stimulation.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-13375 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in the configuration shown in Patent Document 1, cognitive function is determined only by event-related potentials in response to stimulation, so that, for example, in the case of subjects with other functional impairments such as elderly people, cognitive impairment cannot be evaluated with high accuracy.

[0008] Therefore, an object of the present invention is to provide a technique for evaluating a subject's cognitive function with higher accuracy.

[0009] Solutions for solving problems

[0010] The cognitive function evaluation device of the present invention comprises a brain signal detection unit, a response movement detection unit and a computing unit. The brain signal detection unit detects the brain signal generated by the subject in response to stimulation. The response movement detection unit detects the response movement generated by the subject in response to stimulation and outputs a response signal. The computing unit detects event-related potentials and motor readiness potentials based on the brain signals, calculates the response speed based on the response signal, and evaluates cognitive function based on the event-related potentials, motor readiness potentials and response speed.

[0011] In this structure, the cognitive function is evaluated using the event-related potential to the stimulus, the motor preparation potential to the stimulus, and the response speed. Thus, the cognitive function to the stimulus, the motor indication function to the stimulus, and the motor function to the stimulus are used for evaluation, thereby improving the evaluation accuracy of the cognitive function of the subject.

[0012] Effects of the Invention

[0013] According to the present invention, the cognitive function of a subject can be evaluated with higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a functional block diagram of the cognitive function evaluation system according to the first embodiment of the present invention.

[0015] Figure 2 It is a functional block diagram showing the structure of the brain signal detection unit.

[0016] Figure 3 This is a diagram schematically showing a wearing state of a subject wearing a detection gear on cognitive function.

[0017] Figure 4 It is a functional block diagram showing the structure of the calculation unit.

[0018] Figure 5 (A) and Figure 5 (B) is a diagram showing the evaluation concept of cognitive function.

[0019] Figure 6 This is a flowchart showing an example of the cognitive function evaluation method according to the first embodiment.

[0020] Figure 7 This is a flowchart showing an example of cognitive function evaluation.

[0021] Figure 8 This is a flowchart showing an example of a classification method and an evaluation method for cognitive function decline.

[0022] Fig. 9 This is a functional block diagram of a cognitive function evaluation system according to a second embodiment of the present invention.

[0023] Fig.10 This is a flowchart showing an example of the cognitive function evaluation method according to the second embodiment.

[0024] Fig.11 This is a functional block diagram of a cognitive function evaluation system according to a third embodiment of the present invention.

[0025] Fig.12 This is a flowchart showing an example of a cognitive function evaluation method according to the third embodiment.

[0026] Fig.13 This is a flowchart showing an example of a cognitive function evaluation method according to the fourth embodiment.

[0027] Fig.14 This is a flowchart showing an example of a cognitive function evaluation method according to the fourth embodiment.

[0028] Fig.15 This is a flowchart showing an example of a cognitive function evaluation method according to the fifth embodiment. DETAILED DESCRIPTION

[0029] (First Embodiment)

[0030] A cognitive function evaluation system according to a first embodiment of the present invention will be described with reference to the drawings. Figure 1 This is a functional block diagram of the cognitive function evaluation system according to the first embodiment of the present invention. Figure 2 It is a functional block diagram showing the structure of the brain signal detection unit. Figure 3 1 is a diagram schematically showing a wearing state of a subject wearing a detection device on cognitive function. Figure 4 It is a functional block diagram showing the structure of the calculation unit.

[0031] (Structure of cognitive function evaluation system 1)

[0032] like Figure 1 As shown, the cognitive function evaluation system 1 includes a cognitive function evaluation device 10 and a stimulation presentation device 20. The cognitive function evaluation device 10 includes a brain signal detection unit 11, a response movement detection unit 12, and a calculation unit 13.

[0033] (Stimulus Presentation Device 20)

[0034] The stimulus presentation device 20 presents visual stimulation to the subject. For example, the stimulus presentation device 20 is a display capable of displaying a predetermined image.

[0035] The stimulus presentation device 20 displays a first image and a second image of different shapes (for example, two circles of different sizes) at a predetermined period as visual stimulation. At this time, the display frequency of the first image is different from the display frequency of the second image.

[0036] For example, the first image is displayed at a high frequency, and the second image is displayed at a low frequency. More specifically, the first image is displayed normally every second, and the first image at a specific timing is replaced with the second image and displayed.

[0037] The stimulus presentation device 20 presents the visual stimulus by, for example, receiving a visual stimulus presentation start instruction from the computing unit 13 of the cognitive function evaluation device 10. In addition, the stimulus presentation device 20 does not necessarily receive a visual stimulus presentation start instruction from the computing unit 13. For example, the visual stimulus may be presented in synchronization with each processing and each sampling period of the computing unit 13 by other functional units not shown.

[0038] (Brain signal detection unit 11)

[0039] like Figure 2 As shown, the brain signal detection unit 11 includes a brain signal sensor 111 and a brain signal processing unit 112. The brain signal sensor 111 is realized by, for example, a known sensor capable of acquiring brain signals.

[0040] The brain signal sensor 111 uses, for example, Figure 3The detection device 100 shown in FIG. 1 is worn by a subject. The detection device 100 includes a headband 101, a brain signal sensor 1111, and a brain signal sensor 1112. The brain signal sensor 1111 and the brain signal sensor 1112 are connected to Figure 2 The number of brain signal sensors 111 of the detection device 100 is arbitrary.

[0041] The headband 101 is made of a band-shaped base material. The headband 101 has elasticity, for example. The headband 101 is worn on the head 800 of the subject 80. The brain signal sensor 1111 is arranged on the inner side of the part of the headband 101 on the side of the back of the head 801. In addition, the brain signal sensor 1112 is arranged on the inner side of the part of the headband 101 on the side of the front of the head 802. The brain signal sensor 1111 and the brain signal sensor 1112 acquire brain signals of the subject 80 and output the brain signals to the brain signal processing unit 112.

[0042] The brain signal processing unit 112 is implemented by, for example, an electronic circuit, an IC, etc. The brain signal processing unit 112 performs filtering processing, amplification processing, etc. on the brain signal acquired by the brain signal sensor 111 (brain signal sensor 1111, brain signal sensor 1112). The brain signal processing unit 112 outputs the brain signal after the prescribed processing to the operation unit 13. In addition, the detection device 100 is not limited to Figure 3 The disclosed device may be, for example, a device embedded in a head mounted display (HMD), a VR (Vertual Reality) device, or the like.

[0043] (Response motion detection unit 12)

[0044] The response movement detection unit 12 is implemented by, for example, a physical button, a touch panel, or an operation input device (such as a mouse) disposed in the cognitive function evaluation apparatus 10. That is, the response movement detection unit 12 is implemented by a member capable of detecting movement caused by the subject 80 when an event of a cognitive target occurs.

[0045] The response movement detection unit 12 detects the input timing (operation timing) of the response movement performed by the subject 80 and calculates a response signal. The response movement detection unit 12 outputs the response signal to the calculation unit 13.

[0046] (Calculation unit 13)

[0047] like Figure 4 As shown, the calculation unit 13 includes a sampling period determination unit 131, an event-related potential detection unit 132, a movement preparation potential detection unit 133, a response speed detection unit 134, and an analysis unit 135. The calculation unit 13 is realized by an electronic circuit, an IC, an MPU, or the like.

[0048] The sampling period determination unit 131 receives a stimulus trigger from the stimulus presentation device 20 or a response signal from the response motion detection unit 12. The stimulus trigger is a trigger indicating the timing at which an image (video) of a response target is presented. The sampling period determination unit 131 determines a sampling period for detecting an event-related potential and a sampling period for detecting a motor preparatory potential.

[0049] The sampling period determination unit 131 specifies a sampling period for detecting an event-related potential to the event-related potential detection unit 132. The sampling period determination unit 131 specifies a sampling period for detecting an event-related potential to the movement preparation potential detection unit 133.

[0050] The brain signal is input to the event-related potential detection unit 132. The event-related potential detection unit 132 detects an event-related potential (e.g., P300) related to the visual stimulation based on the waveform of the brain signal, etc. during the sampling period for detecting the event-related potential of the visual stimulation. The event-related potential detection unit 132 outputs the detected event-related potential to the analysis unit 135.

[0051] The brain signal is input to the motor preparation potential detection unit 133 . The motor preparation potential detection unit 133 detects the motor preparation potential based on the waveform of the brain signal, etc., during the sampling period for detecting the motor preparation potential. The motor preparation potential detection unit 133 outputs the motor preparation potential to the analysis unit 135 .

[0052] The stimulation trigger and the response signal are input to the response speed detection unit 134. The response speed detection unit 134 detects the response speed using the time difference between the timing of the stimulation trigger and the timing of the response signal. The response speed detection unit 134 outputs the response speed to the analysis unit 135. In addition, the response speed detection unit 134 may detect the response signal using the time difference between the timing of the motor preparatory potential and the timing of the response signal instead of using the time difference between the timing of the stimulation trigger and the timing of the response signal.

[0053] The analysis unit 135 evaluates cognitive function using event-related potential, motor preparation potential, and response speed. More specifically, the analysis unit 135 evaluates cognitive function using, for example, the following method. Figure 5 (A) Figure 5 (B) is a diagram showing the evaluation concept of cognitive function.

[0054] The analysis unit 135 calculates an index INDv related to the recognition of visual stimulation using the event-related potential. The index INDv is calculated using the waveform and amplitude of the event-related potential. For example, the lower the index value, the lower the recognition function for visual stimulation.

[0055] The analysis unit 135 calculates an index INDm related to motor preparation for stimulation using the motor preparation potential. The index INDm is calculated using the waveform, amplitude, generation timing, etc. of the motor preparation potential. For example, the lower the index value, the lower the motor preparation ability for stimulation.

[0056] The analysis unit 135 calculates the index INDr related to the motor function to the stimulation using the response speed. The index INDr is calculated using the speed of the response. For example, the lower the index value, the lower the motor ability to the stimulation.

[0057] The analyzing unit 135 evaluates the cognitive function using the index INDv, the index INDm, and the index INDr.

[0058] For example, regarding the index INDv, the index INDm, and the index INDr, the analyzing unit 135 compares each index of the subject 80 with each index of the cognitive evaluation standard. The analyzing unit 135 evaluates the cognitive function using the comparison result.

[0059] For example, in Figure 5 In the case of (A), the index INDv of the subject 80 is higher than the index INDv of the cognitive evaluation standard. The index INDm of the subject 80 is at the same level as the index INDm of the cognitive evaluation standard. The index INDr of the subject 80 is lower than the index INDr of the cognitive evaluation standard. In this case, the analysis unit 135 evaluates that the ability of the motor system to the stimulus is low although the cognitive function to the stimulus is normal. Thus, for example, the analysis unit 135 evaluates that the ability of the motor system to the stimulus is lower than the general level although there is no problem with the cognitive function.

[0060] On the other hand, when it is detected that the index INDr is lower than the cognitive evaluation standard, the analysis unit 135 evaluates that the cognitive function is low. Thus, for example, the analysis unit 135 evaluates that there is a risk of dementia.

[0061] In addition, for example, regarding the index INDv, the index INDm, and the index INDr, the analysis unit 135 compares each index of the subject 80 this time with each index in the past. The analysis unit 135 evaluates the decline in cognitive function using the result of the comparison. That is, the analysis unit 135 evaluates the decline in cognitive function based on the changes in the index at multiple different times (in other words, the changes in cognitive function).

[0062] For example, in Figure 5In the case of (B), the current index INDv of the subject 80 is lower than the past index INDv. The current index INDm of the subject 80 is at the same level as the past index INDm. The current index INDr of the subject 80 is lower than the past index INDr of the cognitive evaluation standard. In this case, the analysis unit 135 evaluates that the cognitive function and motor ability are reduced.

[0063] On the other hand, when it is detected that the current index INDv is the same as the past index INDv, or the current index INDv is higher than the past index INDv, the analysis unit 135 evaluates that the cognitive function has not declined. And at this time, if the current index INDm and the current index INDr are lower than their past indexes, the analysis unit 135 evaluates that the motor system capacity has declined although the cognitive function has not declined.

[0064] As described above, the cognitive function evaluation system 1 and the cognitive function evaluation device 10 can evaluate cognitive function using multiple indicators including the motor system for visual stimulation. Thus, the cognitive function evaluation system 1 and the cognitive function evaluation device 10 can evaluate the cognitive function of the subject more accurately by also considering the ability of the subject's motor system.

[0065] In addition, the cognitive function evaluation device 10 can also use the above-mentioned event-related potential, motor readiness potential and response speed combination, or the combination of index INDv, index INDm and index INDr to estimate the MMSE (mini-mental status examination) score. For example, the cognitive function evaluation device 10 uses the combination of event-related potential, motor readiness potential and response speed, or the combination of index INDv, index INDm and index INDr as a feature quantity to learn in association with the score of the MMSE score. The cognitive function evaluation device 10 estimates the score of the MMSE score by substituting the combination of event-related potential, motor readiness potential and response speed, or the combination of index INDv, index INDm and index INDr into the estimation formula obtained by the learning.

[0066] Although not shown in the drawings, the cognitive function evaluation device 10 may also include a display to display the evaluation result.

[0067] (Cognitive function evaluation method)

[0068] Figure 6 is a flowchart showing an example of a cognitive function evaluation method according to the first embodiment. Figure 6 For each processing, descriptions of the parts that are the same as those in the above-mentioned structure are omitted.

[0069] The stimulus presentation device 20 presents visual stimulation (S11). The computing unit 13 of the cognitive function evaluation device 10 detects visual event-related potential (S12). The computing unit 13 of the cognitive function evaluation device 10 detects motor readiness potential (S13). The computing unit 13 of the cognitive function evaluation device 10 detects response speed (S14).

[0070] The computing unit 13 of the cognitive function evaluation device 10 evaluates cognitive function using visual event-related potential, motor readiness potential, and response speed (S15). Specifically, the computing unit 13 executes, for example, Figure 7 , Figure 8 Processing shown. Figure 7 This is a flowchart showing an example of cognitive function evaluation. Figure 8 This is a flowchart showing an example of a classification method and an evaluation method for cognitive function decline.

[0071] The calculation unit 13 calculates the index INDv related to visual stimulation using the event-related potential (S51). The calculation unit 13 calculates the index INDm related to the movement instruction using the motor preparation potential (S52). The calculation unit 13 calculates the index INDr related to the motor function using the response speed. In addition, the calculation order of the index INDv, the index INDm, and the index INDr is not limited to this, and they can also be calculated in parallel.

[0072] The calculation unit 13 classifies and evaluates the descending function using the index INDv, the index INDm, and the index INDr (S54). More specifically, the calculation unit 13 performs the following operations, for example: Figure 8 Processing shown.

[0073] If the index INDv related to visual stimulation is abnormal (S541: YES), the calculation unit 13 classifies the state as a state of cognitive decline or a state of low cognitive function (S542). The abnormality of the index INDv means, for example, that the index INDv is lower than a reference value indicating low cognitive function.

[0074] If the index INDv is normal (S541: No), the calculation unit 13 classifies the state as being in a normal cognitive function state (S543). The index INDv is normal, for example, when the index INDv is higher than the reference value indicating low cognitive function. In addition, for the following indexes INDm and INDr, the preset reference value is used in the specific classification as in the case of the index INDv. Therefore, for the following indexes INDm and INDr, the description of the classification method using the reference value is omitted.

[0075] If the index INDm related to exercise preparation is abnormal (S544: YES), the calculation unit 13 classifies the state as a state of decreased exercise instruction function or a state of low exercise instruction function (S545). That is, the calculation unit 13 classifies the state as a state of low exercise instruction function despite normal cognitive function.

[0076] If the index INDm is normal (S544: No), the calculation unit 13 classifies the state as being in a normal state of the exercise instruction function (S546).

[0077] If the index INDr related to motor function is abnormal (S547: Yes), the calculation unit 13 classifies the state as a state of decreased motor function or a state of low motor function (S548). That is, the calculation unit 13 classifies the state as a state of low motor function although the cognitive function and motor instruction function (i.e., brain function) are normal.

[0078] If the index INDr related to the motor function is normal (S547: No), the calculation unit 13 classifies the motor function as being normal (S549). That is, the calculation unit 13 classifies the cognitive function, the exercise instruction function, and the motor function as being normal.

[0079] As described above, the cognitive function evaluation device 10 can classify and evaluate cognitive function by combining the index using event-related potentials with the various indexes related to movement. Thus, the cognitive function evaluation device 10 can evaluate cognitive function with higher accuracy.

[0080] (Second Embodiment)

[0081] The cognitive function evaluation system involved in the second embodiment of the present invention is described with reference to the accompanying drawings. The difference is that the cognitive function evaluation system 1 involved in the first embodiment uses visual stimulation, while the cognitive function evaluation system 1A involved in the second embodiment uses auditory stimulation. The other basic structures and processes of the cognitive function evaluation system 1A are the same as those of the cognitive function evaluation system 1, and the description of the same parts is omitted.

[0082] (Structure and Processing of Cognitive Function Evaluation System 1A)

[0083] Fig. 9 1 is a functional block diagram of a cognitive function evaluation system according to a second embodiment of the present invention. A cognitive function evaluation system 1A according to the second embodiment includes a cognitive function evaluation device 10A and a stimulation presentation device 20A.

[0084] The stimulation presentation device 20A presents auditory stimulation. For example, the stimulation presentation device 20A is a speaker that can emit a predetermined sound.

[0085] The stimulation presentation device 20A emits a first sound and a second sound having different frequencies at a predetermined period as auditory stimulation. At this time, the emission frequency of the first sound is different from the emission frequency of the second sound.

[0086] For example, the first sound is emitted at a high frequency, and the second sound is emitted at a low frequency. More specifically, the first sound is emitted every second, and the first sound at a certain timing is replaced by the second sound.

[0087] The stimulation presentation device 20A receives an instruction to start presentation of auditory stimulation from, for example, the calculation unit 13A of the cognitive function evaluation device 10A, and presents auditory stimulation.

[0088] The computing unit 13A of the cognitive function evaluation device 10A is different from the computing unit 13 of the first embodiment in that the event-related potential of the auditory stimulation is used as the event-related potential. The other structures and processes in the computing unit 13A are the same as those in the computing unit 13, and the description of the parts other than those that need to be newly described is omitted.

[0089] The event-related potential detection unit 132 of the computing unit 13A (see Figure 8 and Figure 4 ) During the sampling period for detecting the event-related potential of the auditory stimulation, the event-related potential (eg, MMN) related to the auditory stimulation is detected based on the waveform of the brain signal, etc. The event-related potential detection unit 132 outputs the detected event-related potential to the analysis unit 135.

[0090] The analysis unit 135 calculates the index INDh related to auditory stimulation using the event-related potential of auditory stimulation. The analysis unit 135 evaluates cognitive function using the index INDh related to auditory stimulation, the index INDm related to exercise instruction, and the index INDr related to motor function.

[0091] (Cognitive function evaluation method)

[0092] Fig.10 This is a flowchart showing an example of the cognitive function evaluation method according to the second embodiment.

[0093] The stimulus presentation device 20A presents an auditory stimulus (S21). The computing unit 13A of the cognitive function evaluation device 10A detects an auditory event-related potential (S22). The computing unit 13A detects a motor readiness potential (S23). The computing unit 13A detects a response speed (S24). The computing unit 13A evaluates cognitive function using the auditory event-related potential (index INDh), the motor readiness potential (index INDm), and the response speed (index INDr) (S25).

[0094] As described above, in the cognitive function evaluation system 1A according to the second embodiment, the cognitive function is evaluated using auditory stimulation. In this case, the cognitive function evaluation system 1A can also evaluate the cognitive function with higher accuracy, similarly to the cognitive function evaluation system 1 .

[0095] (Third Embodiment)

[0096] The cognitive function evaluation system according to the third embodiment of the present invention is described with reference to the accompanying drawings. The difference is that the cognitive function evaluation system 1 according to the first embodiment uses visual stimulation, and the cognitive function evaluation system 1A according to the second embodiment uses auditory stimulation. In contrast, the cognitive function evaluation system 1B according to the third embodiment selects visual stimulation and auditory stimulation for use. The other basic structures and processes of the cognitive function evaluation system 1B are the same as those of the cognitive function evaluation systems 1 and 1A, and the description of the same parts is omitted.

[0097] (Structure and Processing of Cognitive Function Evaluation System 1B)

[0098] Fig.11 1 is a functional block diagram of a cognitive function evaluation system according to a third embodiment of the present invention. A cognitive function evaluation system 1B according to the third embodiment includes a cognitive function evaluation device 10B and a stimulation presentation device 20B.

[0099] The stimulus presentation device 20B selectively presents auditory stimulation and visual stimulation.

[0100] The calculation unit 13B of the cognitive function evaluation device 10B uses the evaluation results of event-related potentials (auditory event-related potentials) including auditory stimulation (evaluation results of auditory cognitive function) and the evaluation results of event-related potentials (visual event-related potentials) including visual stimulation (evaluation results of visual cognitive function) to perform comprehensive evaluation.

[0101] As a comprehensive evaluation, for example, the operation unit 13B compares the evaluation result of the auditory cognitive function with the evaluation result of the visual cognitive function, and uses the result of the lower cognitive function as a comprehensive evaluation. Alternatively, the operation unit 13B scores the evaluation result of the auditory cognitive function and the evaluation result of the visual cognitive function, and uses the average value of their scores as a comprehensive evaluation. Alternatively, the operation unit 13B may also weight one of the evaluation results of the auditory cognitive function and the evaluation result of the visual cognitive function, and evaluate one of the evaluation results with a higher weight as a comprehensive evaluation.

[0102] In this way, the cognitive function evaluation system 1B performs comprehensive evaluation using a plurality of evaluation results obtained using different event-related potentials. Thus, the cognitive function evaluation device 10B can evaluate cognitive function with higher accuracy.

[0103] (Cognitive function evaluation method)

[0104] Fig.12 This is a flowchart showing an example of a cognitive function evaluation method according to the third embodiment.

[0105] The cognitive function evaluation device 10B evaluates the auditory cognitive function (S20: refer to Fig.10 ). The cognitive function evaluation device 10B evaluates the visual cognitive function (S10: refer to Figure 6 The cognitive function evaluation device 10B performs comprehensive evaluation using the evaluation results of the auditory cognitive function and the evaluation results of the visual cognitive function ( S30 ).

[0106] (Fourth Embodiment)

[0107] The cognitive function evaluation system involved in the fourth embodiment of the present invention is described with reference to the accompanying drawings. The cognitive function evaluation system involved in the fourth embodiment has the same structure as the cognitive function evaluation system 1B involved in the third embodiment, but the evaluation method is different. Therefore, the following description of the cognitive function evaluation system involved in the fourth embodiment is based on the differences between the cognitive function evaluation system involved in the third embodiment, and the description of other aspects is omitted.

[0108] Fig.13 , Fig.14 This is a flowchart showing an example of a cognitive function evaluation method according to the fourth embodiment.

[0109] exist Fig.13 In the case of hearing impairment, the cognitive function evaluation system performs a hearing impairment determination test (S41). Specifically, the stimulus presentation device emits a sound for hearing impairment detection. The sound for hearing impairment detection may be the same as the sound for presenting auditory stimulation, or may be different from the sound for presenting auditory stimulation. The cognitive function evaluation device detects the response of the subject 80 to the sound for hearing impairment detection. The response can be detected using the same method as the detection of the response to auditory stimulation.

[0110] When the cognitive function evaluation system determines that the subject 80 does not have a hearing impairment (S42: "No"), it evaluates the auditory cognitive function (S20). Specifically, the cognitive function evaluation device instructs the stimulus presentation device to present an auditory stimulus, so that the stimulus presentation device presents the auditory stimulus. The cognitive function evaluation device uses the auditory stimulus to evaluate the cognitive function.

[0111] When the cognitive function evaluation system determines that the subject 80 has a hearing impairment (S42: "Yes"), the visual cognitive function is evaluated (S10). Specifically, the cognitive function evaluation device instructs the stimulus presentation device to switch from auditory stimulation to visual stimulation to present visual stimulation, so that the stimulus presentation device presents visual stimulation. The cognitive function evaluation device uses visual stimulation to evaluate cognitive function.

[0112] In addition, the determination of whether there is a hearing impairment can be achieved, for example, by repeating the emission of a sound for detecting a hearing impairment and the detection of the recognition of the sound or the detection of a response input based on brain signals a prescribed number of times, and detecting the situation where the recognition of the sound fails to be completed the prescribed number of times, or the situation where the detection of the response input fails to be completed the prescribed number of times.

[0113] exist Fig.14 In the case of hearing impairment, the cognitive function evaluation system performs the same processing as that in the process up to the determination of hearing impairment and the process in the case of hearing impairment. Fig.13 The same treatment is applied to the case. Fig.14 In the case of hearing impairment, the cognitive function evaluation system performs the following processing.

[0114] The cognitive function evaluation system performs an evaluation of the auditory cognitive function and an evaluation of the visual cognitive function ( S20 , S10 ). The cognitive function evaluation system performs a comprehensive evaluation using the evaluation of the auditory cognitive function and the evaluation of the visual cognitive function ( S30 ).

[0115] As described above, the cognitive function evaluation system can evaluate the cognitive function with higher accuracy by taking the physical condition of the subject into consideration.

[0116] (Fifth Embodiment)

[0117] A cognitive function evaluation system according to a fifth embodiment of the present invention will be described with reference to the accompanying drawings. The cognitive function evaluation system according to the fifth embodiment is different from the cognitive function evaluation system according to the fourth embodiment. Fig.14 The difference of the cognitive function evaluation system in the processing shown is that an initial test is added and the results of the initial test are reflected in the comprehensive evaluation. The processing of the cognitive function evaluation system involved in the fifth embodiment is the same as the processing of the cognitive function evaluation system involved in the fourth embodiment, and the description of the same parts is omitted.

[0118] Fig.15 This is a flowchart showing an example of a cognitive function evaluation method according to the fifth embodiment.

[0119] The cognitive function evaluation system performs an initial test ( S51 ). The initial test is, for example, at least one of a test for detecting the wearing state and a test for measuring the concentration level of the subject 80 .

[0120] In the test of detecting the wearing state of the detection device 100, the cognitive function evaluation system detects the wearing state by, for example, measuring the amplitude of the brain signal. For example, if the amplitude is less than a predetermined threshold, it is determined that there is a problem with the wearing state, and if the amplitude is greater than the predetermined threshold, it is determined that the wearing state is normal. In addition, in the case where there is a problem with the wearing state, the cognitive function evaluation system can notify the subject 80, the evaluator, etc. that there is a problem with the wearing state. As a result, for example, assistance can be provided to correct the wearing state to normal.

[0121] In a test for measuring the degree of concentration, the cognitive function evaluation system, for example, performs frequency analysis on brain signals to determine the state of alpha waves. The cognitive function evaluation system determines the state of the subject 80, such as inability to concentrate, based on the state of alpha waves (brain signals of a specific frequency). For example, if the alpha waves are within the normal value range, the cognitive function evaluation system estimates that the subject 80 is normal, and if the alpha waves are outside the normal value range, the cognitive function evaluation system estimates that the subject 80 is abnormal. Abnormal here means, for example, the possibility of cognitive function decline.

[0122] If the state and wearing state of the subject 80 are normal (S52: YES), the cognitive function evaluation system shifts to the hearing impairment determination test (S41).

[0123] If the state of subject 80 is abnormal (S52: No), the cognitive function evaluation system reflects the result of the determination in the comprehensive evaluation (S30A). If the state of subject 80 is abnormal, the cognitive function evaluation system may not evaluate the cognitive function (evaluation impossible).

[0124] As described above, the cognitive function evaluation system can evaluate cognitive function with higher accuracy by taking into account the wearing state of the detection device 100 and the physical and mental states of the subject.

[0125] <1> A cognitive function evaluation device, comprising:

[0126] A brain signal detection unit that detects brain signals generated by the subject in response to stimulation;

[0127] a response motion detection unit, which detects the response motion of the subject to the stimulus and outputs a response signal; and

[0128] A calculation unit detects an event-related potential and a motor readiness potential from the brain signal, calculates a response speed from the response signal, and evaluates cognitive function based on the event-related potential, the motor readiness potential, and the response speed.

[0129] <2> according to <1> A cognitive function evaluation device, wherein:

[0130] The operation unit performs the following processing:

[0131] Calculating a first index related to stimulus cognition using the event-related potential;

[0132] Calculating a second index related to the movement instruction using the movement readiness potential;

[0133] Calculating a third index related to motor function using the response speed;

[0134] The cognitive function is evaluated using the first index, the second index, and the third index.

[0135] <3> according to <1> or <2> A cognitive function evaluation device, wherein:

[0136] The operation unit performs the following processing:

[0137] evaluating the cognitive function at different multiple times;

[0138] The decline in cognitive function is evaluated based on changes in cognitive function at the plurality of time points.

[0139] <4> according to <1> to <3> The cognitive function evaluation device of any one of the above, wherein

[0140] The calculation unit estimates an MMSE score using the evaluation result of the cognitive function.

[0141] <5> A cognitive function evaluation system having:

[0142] according to <1> to <4> A cognitive function evaluation device as described in any one of the above; and

[0143] A stimulus presenting device presents the stimulus to the subject.

[0144] <6> according to <5> The cognitive function evaluation system, in which

[0145] The stimulus presentation device presents visual stimulus,

[0146] The calculation unit detects an event-related potential generated by the visual stimulation as the event-related potential.

[0147] <7> according to <5> The cognitive function evaluation system, in which

[0148] The stimulus presentation device presents auditory stimulation,

[0149] The calculation unit detects an event-related potential generated by the auditory stimulation as the event-related potential.

[0150] <8> according to <5> The cognitive function evaluation system, in which

[0151] The stimulus presentation device selectively presents visual stimulation and auditory stimulation,

[0152] The operation unit performs the following processing:

[0153] detecting at least one of an event-related potential generated due to the visual stimulation and an event-related potential generated due to the auditory stimulation as the event-related potential;

[0154] The cognitive function is evaluated using an event-related potential generated due to the visual stimulation or an event-related potential generated due to the auditory stimulation.

[0155] <9> according to <8> The cognitive function evaluation system, in which

[0156] The stimulus presentation device presents a sound for hearing impairment detection before presenting the auditory stimulus.

[0157] The operation unit performs the following processing:

[0158] Using at least the brain signal to detect hearing impairment;

[0159] When the hearing impairment is detected, instructing the stimulus presentation device to present the visual stimulus,

[0160] The stimulus presentation device presents the visual stimulus,

[0161] The calculation unit evaluates the cognitive function using an event-related potential generated by the visual stimulation.

[0162] <10> according to <5> to <9> The cognitive function evaluation system of any one of the above, wherein:

[0163] The operation unit performs the following processing:

[0164] Before presenting the stimulus, using brain signals of specific frequencies among the brain signals to estimate the likelihood of cognitive decline;

[0165] The results of the estimation are also used to evaluate the cognitive function.

[0166] Description of Reference Numerals

[0167] 1, 1A, 1B: cognitive function evaluation system; 10, 10A, 10B: cognitive function evaluation device; 11: brain signal detection unit; 12: response movement detection unit; 13, 13A, 13B: operation unit; 20, 20A, 20B: stimulus presentation device; 80: subject; 100: detection equipment; 101: headband; 111, 1111, 1112: brain signal sensor; 112: brain signal processing unit; 131: sampling period determination unit; 132: event-related potential detection unit; 133: motor preparation potential detection unit; 134: response speed detection unit; 135: analysis unit; 800: head; 801: back of the head; 802: front of the head.

Claims

1. A cognitive function evaluation device, comprising: A brain signal detection unit that detects brain signals generated by the subject in response to stimulation; a response motion detection unit, which detects the response motion of the subject to the stimulus and outputs a response signal; and A calculation unit detects event-related potentials and motor readiness potentials from brain signals, calculates response speed from the response signal, and evaluates cognitive function based on the event-related potentials, the motor readiness potentials, and the response speed.

2. The cognitive function evaluation device according to claim 1, wherein: The operation unit performs the following processing: Calculating a first index related to stimulus cognition using the event-related potential; Calculating a second index related to the movement instruction using the movement readiness potential; The response speed is used to calculate a third index related to motor function; the first index, the second index and the third index are used to evaluate the cognitive function.

3. The cognitive function evaluation device according to claim 1 or 2, wherein: The operation unit performs the following processing: evaluating the cognitive function at different multiple times; The decline in cognitive function is evaluated based on changes in cognitive function at the plurality of time points.

4. The cognitive function evaluation device according to any one of claims 1 to 3, wherein: The calculation unit estimates a Mini-Mental State Examination (MMSE) score using the evaluation result of the cognitive function.

5. A cognitive function evaluation system comprising: The cognitive function evaluation device according to any one of claims 1 to 4; and A stimulus presenting device presents the stimulus to the subject.

6. The cognitive function evaluation system according to claim 5, wherein: The stimulus presentation device presents visual stimuli, The calculation unit detects an event-related potential generated by the visual stimulation as the event-related potential.

7. The cognitive function evaluation system according to claim 5, wherein: The stimulus presentation device presents auditory stimulation, The calculation unit detects an event-related potential generated by the auditory stimulation as the event-related potential.

8. The cognitive function evaluation system according to claim 5, wherein: The stimulus presentation device selectively presents visual stimulation and auditory stimulation, The operation unit performs the following processing: detecting at least one of an event-related potential generated due to the visual stimulation and an event-related potential generated due to the auditory stimulation as the event-related potential; The cognitive function is evaluated using an event-related potential generated due to the visual stimulation or an event-related potential generated due to the auditory stimulation.

9. The cognitive function evaluation system according to claim 8, wherein: The stimulus presentation device presents a sound for hearing impairment detection before presenting the auditory stimulus. The operation unit performs the following processing: Using at least the brain signal to detect hearing impairment; When the hearing impairment is detected, instructing the stimulus presentation device to present the visual stimulus, The stimulus presentation device presents the visual stimulus, The calculation unit evaluates the cognitive function using an event-related potential generated by the visual stimulation.

10. The cognitive function evaluation system according to any one of claims 5 to 9, wherein: The operation unit performs the following processing: Before presenting the stimulus, using brain signals of specific frequencies among the brain signals to estimate the likelihood of cognitive decline; The results of the estimation are also used to evaluate the cognitive function.

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