JP5592664B2 - Comfort determination device - Google Patents

Description

  The present invention relates to a comfort determination device that determines pleasure / discomfort based on an electroencephalogram.

  Electrical activity occurs when the brain of a human or animal is moving, and the electrical activity can be measured as an electroencephalogram by attaching electrodes on the scalp or the brain surface. In addition, it is said that the electroencephalogram can determine the person's psychological state and physiological state based on the frequency. For example, an electroencephalogram having a frequency of 14 to 30 Hz is called a β wave, and has a waveform that appears when awakened or when consciousness is tense. In addition, an electroencephalogram having a frequency of 7 to 13 Hz is called an α wave, and is a waveform that appears when relaxing. An electroencephalogram having a frequency of 4 to 6 Hz is called a θ wave, and has a waveform that appears in a shallow sleep state. An electroencephalogram having a frequency of 0.5 to 4 Hz is called a δ wave, and has a waveform that appears in a deep sleep state. For this reason, in recent years, a system for controlling equipment and the like using a detected brain wave has been developed.

  For example, a comfortable environment creation system disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 8-71050) includes state setting means for setting an environment desired by an individual, brain wave detection means for detecting an individual's brain wave, and brain wave detection means. From the comfort evaluation means for evaluating an individual's psychological state and the like based on the electroencephalogram information obtained in Step 1, the comparison determination means for comparing the output from the state setting means and the output from the comfort evaluation means, and the comparison determination means And a control means for controlling the device based on the output of. In this comfortable environment creation system, first, using the detected brain wave information, comfort is evaluated based on the frequency band of the most intense brain wave, or based on the brain wave intensity for each frequency band within a predetermined time. Comfort is evaluated. Then, the current individual state based on the evaluated comfort is compared with the state desired by the individual set by the state setting means, and the physiological result or psychological state desired by the individual is obtained using the comparison result. So that the equipment is controlled. In this way, this comfortable environment creation system attempts to create a comfortable environment.

  However, the comfortable environment creation system of Patent Document 1 does not disclose which part of the brain wave should be measured and analyzed in the subject's head. For this reason, there is a possibility that an erroneous evaluation of comfort may be performed when measuring the electroencephalogram at a site that is not related to human pleasure / discomfort.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a comfort determination device that can reduce the possibility that pleasure / discomfort is erroneously determined.

The comfort determination device according to the first invention includes an electroencephalogram measurement means and a determination means. The electroencephalogram measurement means can measure the electroencephalogram at the head of any one of the right side, left rear side, and right top of the subject. The determination means extracts a predetermined frequency band of the electroencephalogram measured by the electroencephalogram measurement means. The determination means determines whether the cold stimulus is pleasant or uncomfortable based on the extracted amplitude value of the predetermined frequency band.

In the comfort determination device according to the first aspect of the present invention, the cold stimulus is based on the amplitude value of a predetermined frequency band in the electroencephalogram measured at any one of the right head, left rear head and right parietal region. free-for discomfort has been determined.

  As a result of intensive studies by the inventor, it has been found that there is a correlation between the amplitude value of β waves detected in the right temporal region, the left rear temporal region, and the right temporal region and pleasant / discomfort sensations. For this reason, for example, when a β wave is extracted as a predetermined frequency band, it is possible to determine pleasure / discomfort based on the amplitude value of the β wave.

As a result, it is possible to reduce the possibility that the pleasantness / discomfort with respect to the cold stimulus is erroneously determined.

A comfort determination device according to a second aspect of the present invention is the comfort determination device of the first aspect, wherein the predetermined frequency band is a frequency band around the β wave. For this reason, with this comfort determination device, it is possible to determine whether the cold stimulus is pleasant or uncomfortable based on the amplitude value of the β wave.

  The β wave here is an electroencephalogram having a frequency of 14 to 30 Hz.

  A comfort determination device according to a third aspect of the present invention is the comfort determination device of the first or second aspect, wherein the electroencephalogram is an activity in any one region of the right island cortex, the left island cortex and the somatosensory area. It is an electroencephalogram that reflects.

  As a result of the inventor's earnest study, the β wave detected in the right temporal region reflects the activation of the right insular cortex, and the β wave detected in the left rear temporal region reflects the activation of the left insular cortex. The β wave detected at the right parietal region was found to reflect the activation of the somatosensory cortex. For this reason, with this comfort determination device, it is possible to measure an electroencephalogram that reflects the activity of at least one of the right island cortex, the left island cortex, and the somatosensory area.

The fourth invention comfort determination device according to from the first invention be any comfort determination apparatus of the third aspect of the present invention, EEG means measures brain waves of the left rear side head.

In the comfort determination device according to the first aspect of the present invention, it is possible to reduce the possibility that the pleasantness / discomfort with respect to the cold stimulus is erroneously determined.

In the comfort determination device according to the second aspect of the present invention, it is possible to determine the comfort / discomfort with respect to the cold stimulus based on the amplitude value of the β wave.

  In the comfort determination device according to the third aspect of the invention, an electroencephalogram that reflects the activity of at least one of the right island cortex, the left island cortex, and the somatosensory cortex can be measured.

  In the comfort determination device according to the fourth aspect of the invention, the electroencephalogram measurement means measures the electroencephalogram of the left temporal region.

The figure which shows the correlation with the amplitude of beta wave detected in a right side head, and pleasant / unpleasant sensation evaluation. The figure which shows the correlation with the amplitude of a beta wave detected in a left back temporal region, and pleasant / unpleasant sensation evaluation. The figure which shows the correlation with the amplitude of (beta) wave detected in a right parietal part, and pleasant / unpleasant sensation evaluation. The figure which shows the correlation with the amplitude of the alpha wave detected in a right side head, and pleasant / unpleasant sensation evaluation. The figure which shows the correlation with the amplitude of the alpha wave detected in a left back temporal region, and pleasant / unpleasant sensation evaluation. The figure which shows the correlation with the amplitude of the alpha wave detected in a right top part, and pleasant / unpleasant sensation evaluation. It is a figure which shows the measurement result of the active region of the brain at the time of giving an unpleasant stimulus, Comprising: (a) The figure which shows the measurement result of the brain area | region containing the right island cortex and the left island cortex, (b) Somatosensory cortex The figure which shows the measurement result of the brain area | region containing A. 1 is a schematic diagram of a comfort determination device according to an embodiment of the present invention.

  Before describing the embodiment of the present invention, first, the knowledge by the present inventor, which became an important basis for the inventor to make the present invention, will be described.

<Key points of knowledge by the present inventor>
The present inventor first conducted an extensive study on the relationship between the electroencephalogram measured at a number of sites on the scalp and pleasant / unpleasant sensations, and as a result, detected at each site of the right temporal region, the left back temporal region, and the right temporal region. We found that there was a significant relationship between the amplitude of the generated β wave and the feeling of comfort and discomfort. Here, the detection of β waves at each part means that a β wave appears in the electroencephalogram measured at each part.

  Specifically, it has been found that when a person is subjectively uncomfortable, the amplitudes of β waves on the right temporal region, the left rear temporal region, and the right temporal region increase. For this reason, in order to evaluate human comfort and discomfort, it was considered effective to analyze the β waves detected in each part of the right temporal region, left posterior temporal region, and right temporal region. . Therefore, the present inventor has reached the present invention described later by paying attention to this point.

<Electroencephalogram analysis method and comfort / discomfort evaluation method>
Next, an electroencephalogram analysis method and a pleasant / unpleasant sensation evaluation method used when the present inventor obtains the above knowledge will be described.

  Eight test subjects (5 males, 3 females, 20s to 40s) were given cold stimulation as an unpleasant stimulus, and electroencephalogram analysis was performed while the cold stimulus was being applied, while being pleasant and uncomfortable. Introspective reports of sensory evaluation were collected. In addition, provision of the cold irritation | stimulation with respect to a test subject was performed in the shield room of room temperature 25 degreeC and humidity 51-61%.

  Specifically, the cold stimulus was applied by bringing the tip of the subject's left middle finger (the part from the tip of the finger to the first joint) into contact with the cold pad. In addition, the cold stimulation was continuously applied to the subject for 10 minutes by keeping the subject's fingertip in contact with the cold pad for 10 minutes. The temperature of the cold pad was set to 1 ° C.

  In the electroencephalogram analysis, the electroencephalogram was measured, and the electroencephalogram amplitude value was calculated by frequency analysis of the measured electroencephalogram. We also measured the area of brain activity.

  The electroencephalogram was measured by connecting an electrode (64 ch) on the scalp of the subject. For the electroencephalogram measurement, an EGI net station system 200 was used.

  The frequency analysis of the electroencephalogram was performed on the electroencephalogram measured during the cold stimulation (10 minutes). In EEG frequency analysis, the measured EEG is divided every minute, and the FFT (Fast Fourier Transform) processing is performed on the EEG of each section, so that the average amplitude value (μV) of α wave and β wave for each minute is obtained. Calculated. In addition, BESA made by MEGIS Software was used for the frequency analysis of the electroencephalogram. Furthermore, in the frequency analysis, as the setting of the electroencephalogram frequency filter, the Low Cut filter was set to 1.6 Hz, the High Cut filter was set to 30 Hz, and the Hum filter was set to 50 Hz.

  The brain active area was measured when cold stimulation was applied to two of the eight subjects using functional magnetic resonance imaging (fMRI). For the measurement of the brain activation area, SIGNA 1.5T Excite system manufactured by GE (General Electric) was used.

  Pleasure / discomfort sensation was evaluated by evaluating the subject's subjective comfort / discomfort level numerically. Specifically, the degree of comfort / discomfort while giving a cold stimulus to the subject (10 minutes) was displayed on the subject himself / herself with a score every minute. The degree of comfort / discomfort was evaluated in the range of −9 to 9, and the lower the score, the more unpleasant.

<Results of electroencephalogram analysis and evaluation of comfort / discomfort>
From the results obtained by the above-mentioned electroencephalogram analysis method and pleasant / unpleasant sensation evaluation method, the amount of β-wave activation detected in the right, left occipital, and right parietal regions of the plurality of head regions, respectively. There was a significant correlation between the evaluation of pleasant and unpleasant feeling (see FIGS. 1, 2 and 3). In addition, as a comparative example, as a result of examining whether there is a correlation between the activation amount of the α wave detected in the right temporal region, the left posterior temporal region and the right parietal region and the evaluation of pleasant / discomfort sensation, As shown in FIGS. 4, 5, and 6, there was no correlation between the activation amount of the α wave and the evaluation regarding subjective pleasure / discomfort. As a result, the lower the score in the subjective evaluation of pleasant / unpleasant sensation, that is, the greater the subjective unpleasant sensation, the larger the amplitude of the β wave detected in the right temporal region, the left rear temporal region and the right temporal region. It was shown to be.

  Furthermore, from the measurement result by fMRI, as shown in FIG. 7, activation of the right island cortex, the left island cortex, and the somatosensory area was confirmed.

  From these results, the present inventor has obtained the following knowledge.

  A comparison was made between the amount of β wave activation in the right temporal region, left occipital region, and right parietal region observed by applying cold stimuli to subjects, and subjective evaluation of pleasantness and discomfort. Admitted. In other words, the increase / decrease in the amplitude value of the β wave detected in the right temporal region, the left occipital region, and the right temporal region is closely related to subjective pleasure / discomfort, and has a high correlation. ing. That is, it has been found that β waves detected in the right temporal region, the left rear temporal region, and the right temporal region can serve as an index for determining physiological comfort / discomfort. From this, the present inventor can determine human comfort / discomfort based on the amplitude value of the β wave detected in at least one of the right temporal region, the left rear temporal region, and the right temporal region. The knowledge that there is.

  Here, “the amplitude of the electroencephalogram” means “the height from the trough to the peak of the waveform of the electroencephalogram”, that is, the amplitude value. Further, the activation amount of the β wave here means the amplitude value of the β wave.

<Comfort determination device>
Next, the comfort determination device 80, which is an embodiment of the present invention that has been completed by the present inventors, will be described based on the knowledge described above.

  FIG. 8 is a schematic diagram of the comfort determination device 80 according to the embodiment of the present invention.

  The comfort determination device 80 is a device that can determine whether an individual (subject) is in a pleasant state or an unpleasant state. The comfort determination device 80 includes an electroencephalogram measurement unit 20 and a pleasant / uncomfortable determination unit 40.

  The electroencephalogram measurement unit 20 includes an electrode unit (not shown) for measuring individual electroencephalogram data, and is connected to the pleasant / discomfort determination unit 40 by wire. In addition, the electrode part is mounted on the scalp corresponding to the right side of the head of the individual. Furthermore, the electroencephalogram measurement unit 20 transmits the measured electroencephalogram data to the pleasant / unpleasant determination unit 40. In the present embodiment, the electrode portion is mounted on the scalp corresponding to the right side of the head. However, the present invention is not limited to this, and at least one of the right side, left rear side, and right top of the head is not limited thereto. It suffices to be mounted on the scalp corresponding to one part. In the present embodiment, the electroencephalogram measurement unit 20 and the pleasant / unpleasant determination unit 40 are connected by wire. However, if the measured electroencephalogram data can be transmitted to the pleasant / unpleasant determination unit, even if the connection is wireless. Good.

  The comfort / discomfort determination unit 40 determines comfort based on the measured brain waves. Specifically, the comfort / discomfort determination unit 40 determines comfort using β waves as an index. More specifically, the pleasant / unpleasant determination unit 40 determines a pleasant / unpleasant state based on an increase / decrease in the amplitude value of the β wave.

  The pleasant / uncomfortable determination unit 40 includes an analysis unit 41 and a determination unit 42.

  The analysis unit 41 creates frequency band data and β-wave amplitude value data by performing frequency analysis processing based on the electroencephalogram data. The analysis unit 41 includes an acquisition unit 43 and a calculation unit 44.

  The acquisition unit 43 amplifies the electroencephalogram data transmitted from the electroencephalogram measurement unit 20 every predetermined time (for example, 1 minute) (hereinafter referred to as one section), and converts the analog signal into a digital signal. Process.

  The calculation unit 44 performs FFT processing on the electroencephalogram data that has been subjected to A / D conversion processing in the acquisition unit 43, separates it for each frequency component, and calculates a power spectrum (intensity) for each frequency band. The frequency bands of the brain waves are δ waves (0.5 to 4 Hz), θ waves (4 to 8 Hz), α waves (8 to 13 Hz), and β waves (13 to 35 Hz). Furthermore, the calculating part 44 transmits the frequency component with the largest power spectrum to the determination part 42 mentioned later as frequency band data. In addition, when the power spectrum of the β wave is the highest, the calculation unit 44 extracts one section of the β wave and transmits the maximum amplitude of the β wave in the one section to the determination unit 42 as amplitude value data.

  The determination unit 42 determines whether the individual is in a pleasant state or an unpleasant state based on the frequency data and the amplitude value data of the β wave. Specifically, the determination unit 42 determines whether or not the user is in an uncomfortable state based on the amplitude value data of the β wave. More specifically, the determination unit 42 determines that the current state is the unpleasant state when the value of the current amplitude value data of the β wave transmitted from the calculation unit 44 is equal to or greater than a predetermined value. . Further, the determination unit 42 determines that the current state is the pleasant state when the value of the current amplitude value data of the β wave transmitted from the calculation unit 44 is less than the predetermined value. Furthermore, when the frequency band of the frequency band data transmitted from the calculation unit 44 is a frequency band other than the β wave, the determination unit 42 determines that the state is a pleasant state.

  With this configuration, the comfort determination device 80 can determine a pleasant / uncomfortable feeling based on the detected amplitude value of the β wave. For this reason, the determination result by the comfort determination device 80 is displayed on a display or the like, so that it is possible to notify whether the individual is in a pleasant state or an uncomfortable state. In addition, by controlling the equipment and the like using the determination result, it is possible to approach the environment desired by the individual.

<Features>
(1)
The inventor has a correlation between the increase / decrease in the amplitude value of the β wave detected in the right head, left head and right top and the subjective pleasure / discomfort. It was found that the larger the value, the larger the amplitude value of the β wave. Therefore, in the above embodiment, the brain wave of the right temporal region is measured, and frequency analysis is performed on the measured brain wave. In the frequency analysis, when the power spectrum of the β wave is the highest, the amplitude value of the β wave is calculated. That is, a pleasant / unpleasant state is determined based on the amplitude value of the β wave detected in the right head. For this reason, it can be determined that the user is in an uncomfortable state based on the amplitude value of the β wave.

  As a result, it is possible to reduce the possibility that pleasure / discomfort is erroneously determined.

(2)
In the above embodiment, the electroencephalogram of the right temporal region is measured. In addition, activation of the right insular cortex, left insular cortex, and somatosensory cortex was observed by applying cold stimulation to the subject, and β detected in the right temporal region, the left rear temporal region, and the right temporal region The amplitude of the wave is closely related to the activation of the right, left, and somatosensory cortex, and the beta waves detected in the right, left posterior, and right parietal areas are the right cortex The inventor has obtained the knowledge that the activation of the left island cortex and somatosensory cortex is reflected. For this reason, an electroencephalogram that reflects the activity of the right island cortex region can be measured.

<Modification>
In the above embodiment, pleasantness / discomfort is determined based on whether or not the amplitude value of the β wave is equal to or greater than a predetermined value.

  Alternatively, the past β wave amplitude value and the current β wave amplitude value may be compared to determine that the state is uncomfortable when the amplitude value increases.

  Moreover, in the said embodiment, the predetermined value used as the determination standard of pleasant / unpleasant is preset.

  Instead, a predetermined value serving as a determination criterion for pleasure / discomfort may be determined based on the amplitude value of the person's β wave and the person's comfort / discomfort evaluation.

  For example, the pleasant / unpleasant determination unit compares an input unit that allows an individual to input subjective pleasant / unpleasant evaluation, and an evaluation input from the input unit and an amplitude value of a β wave calculated by the computing unit. In the case of further including a determination unit that determines a pleasant / unpleasant reference value, a pleasant / unpleasant reference value (corresponding to a predetermined value) that is a determination criterion for pleasant / unpleasant can be determined on an individual basis. As a result, the accuracy of the pleasant / unpleasant determination can be improved.

  Since the present invention is an invention relating to a comfort determination device that can reduce the possibility that pleasure / discomfort is erroneously determined, application to various devices that require determination of comfort is effective.

20 Electroencephalogram measurement unit (electroencephalogram measurement means)
40 Pleasure / discomfort determination unit (determination means)
80 Comfort determination device

JP-A-8-71050

Claims (4)

Subjects the right temporal, and measurable EEG means an electroencephalogram any one site left rear head and right parietal (20),
A determination means (40) for extracting a predetermined frequency band of the electroencephalogram measured by the electroencephalogram measurement means and determining pleasantness / discomfort with respect to a cold stimulus based on an amplitude value of the predetermined frequency band;
A comfort determination device (80) comprising: The predetermined frequency band is a frequency band around the β wave,
The comfort determination device according to claim 1. The electroencephalogram is an electroencephalogram reflecting the activity of any one region of the right island cortex, the left island cortex and the somatosensory cortex.
The comfort determination device according to claim 1 or 2. The EEG measuring means measures the brain waves of the left rear head,
The comfort determination device according to any one of claims 1 to 3.