JP2006187305A - Organism signal processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organism signal processor capable of obtaining a light measurement image correlated to the cerebral function. <P>SOLUTION: The organism signal processor comprises light measurement devices 1-3 and 5-13 for measuring the transmission light or reflection light of the light applied to the head of a subject 4 and finding optical characteristics inside the head based on the light measurement data, a stimulation presenting device 21 for applying stimulation to the subject, and brain wave measuring devices 30-31 for measuring organism signals correlated to the activity of the subject. The subject is alerted by intensifying the stimulation based on the brain waves and the optical characteristics are obtained by selecting the light measurement data. In this way, the state of activity of the brain of the subject is retained in the allowable range according to conditions for the light measurement, so that a light measurement image correlated to the cerebral function can be stably obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a biological signal processing apparatus, and more particularly to a biological signal processing apparatus suitable for brain function measurement formed by combining an optical measurement apparatus and another measurement apparatus such as an electroencephalogram measurement apparatus.

  The optical measurement device is called OCT (Optical Coherence Topography) and irradiates light on a living body as a subject to measure transmitted light from the living body or scattered light from inside the living body, and images differences in optical characteristics inside the living body. It is a device to convert. According to this optical measurement device, it is expected to be used in fields such as clinical medicine and brain science because it can measure biological metabolites and blood flow, and measure biological functions in a simple and harmless manner to the living body. Yes.

  For example, activation of higher brain functions is closely related to oxygen metabolism and blood circulation inside the living body, and these correspond to the concentration of a specific pigment (such as hemoglobin) in the living body. Therefore, multiple wavelengths of the visible to infrared region that are easily absorbed by the specific dye are irradiated to multiple parts of the brain, and the light that has passed through the brain is detected from the multiple parts. It has been proposed to measure the higher-order function of the brain by imaging the concentration of a substance, the concentration of hemoglobin in blood, and the like (Patent Document 1).

JP-A-9-149903

  By the way, according to the conventional optical measurement device, when measuring higher-order functions such as thinking, language, and movement, the brain is stimulated by hearing or vision, and the state change of the brain before and after it is imaged. Diagnose brain function by contrasting images.

  However, although the analysis of the relationship between the brain state and stimuli appearing in the optical measurement image is underway, there is no consideration for associating it with the brain function. It hasn't been done yet.

  Therefore, an object of the present invention is to realize a biological signal processing apparatus that can acquire an optical measurement image associated with a brain function.

  In order to solve the above problems, the present invention is characterized in that an optical measurement device and another measurement device such as an electroencephalogram measurement device are organically coupled. That is, in the field of brain science, electrodes are brought into contact with the scalp and the like to measure brain waves generated by brain activity, and to generate brain wave signals (α waves, β waves, θ waves, δ waves, etc.) in specific frequency bands. Based on this, attempts have been made to analyze higher-order brain functions such as intellectual movements such as thinking and language and motor functions. For example, development research is progressing to obtain a two-dimensional electroencephalogram by contacting many electrodes on the scalp surface, analyze the function of each part of the brain, diagnose the presence or absence of brain damage, etc., and reflect it in medicine Yes.

  Accordingly, the present invention provides an optical measurement device for measuring transmitted light or reflected light of light irradiated on the head of a subject and obtaining optical characteristics in the head based on the optical measurement data, and stimulating the subject. A biological signal processing device provided with a stimulus presentation device for providing a biological activity measurement device for measuring a biological signal correlated with the activity of the subject, wherein the stimulus presentation device is provided with the biological activity measurement device The stimulation is controlled based on the biological signal measured by. Thereby, since the stimulus given to the subject can be controlled, the activity state of the brain can be maintained in an allowable range according to the optical measurement conditions. As a result, an optical measurement image associated with the brain function can be acquired stably.

  In this case, typically, an electroencephalogram measurement apparatus that measures an electroencephalogram of a subject is used as the life activity measurement apparatus. In this case, the stimulus presentation device can control the stimulus according to the intensity of the θ wave or the β wave output from the electroencephalogram measurement device. That is, when the intensity of the θ wave or the β wave is high, it is considered that the state of wakefulness or attention (attention or concentration) is high. Therefore, for example, in the case of optical measurement of a brain function in an arousal state or a state of high attention intensity, an efficient optical measurement is performed under stable measurement conditions by presenting an arousal stimulus. be able to.

  In addition, as the life activity measuring device, a body motion measuring device that measures the movement of, for example, a cervical muscle of a subject can be used instead of the electroencephalogram measuring device. In this case, the stimulus presentation device controls the stimulation based on the amount of body movement that is the movement of the subject's neck.

  In addition to or in addition to controlling the stimulus based on the biological signal measured by the biological activity measurement device, the optical measurement device selects optical measurement data based on the biological signal and obtains optical characteristics. Can be. According to this, the accuracy of the optical measurement can be improved by discarding the optical measurement data when the measurement condition is not met.

  Moreover, it is preferable to provide an eye-opening detection device that measures the degree of eye opening of the subject and to calibrate the α wave measured by the electroencephalogram measurement device according to the degree of eye opening. Thereby, the intensity | strength of the alpha wave which fluctuates according to an eye opening degree can be calibrated, and a measurement precision can be improved further.

  Furthermore, it is preferable to provide sampling pulse generation means for cooperatively controlling the measurement of the optical measurement means and the electroencephalogram measurement means. In this case, the sampling pulse generating means continuously presents a plurality of stimuli from the stimulus presenting device, performs measurement of the electroencephalogram measuring device for each stimulus presenting, and performs optical measurement during a plurality of stimulus presenting periods. Let the instrument measure once. Alternatively, after the stimulus presentation device presents a single stimulus and the optical measurement device performs the measurement once, the same stimulus is presented from the stimulus presentation device a plurality of times in a certain pause period. Thus, it is possible to cause the electroencephalogram measurement apparatus to perform measurement for each presentation of the stimulus. Thereby, measurement cooperation of optical measurement and electroencephalogram measurement with different measurement principles can be achieved.

  ADVANTAGE OF THE INVENTION According to this invention, the biological signal processing apparatus which can acquire the optical measurement image linked | related with the brain function is realizable.

[Embodiment 1]
FIG. 1 shows an overall configuration diagram of an embodiment of a biological signal processing apparatus of the present invention. The present embodiment is a system in which an optical measurement device and an electroencephalogram measurement device are combined. In the figure, a plurality (two in the illustrated example) of light sources 1 generate near-infrared light having a wavelength of about 600 to 1200 nm that is likely to pass through the human body. Near-infrared light generated from the light source 1 is guided to an optical directional coupler (optical coupler) 2 through an optical fiber, mixed, and coupled so as to be transmitted by one optical fiber 3 for irradiation light. The tip of the optical fiber 3 is attached to a head cap (not shown) so as to be held at a desired position on the head of the subject 4.

  The tip of the optical fiber 5 for condensing is fixed to the head cap, and the signal light returned to the outside while being scattered from the inside of the head of the subject 4 is guided to the photodetector 6. The photodetector 6 is composed of a photodiode or a photomultiplier tube and converts incident signal light into an electric signal. The signal light converted into an electrical signal by the photodetector 6 is input to a plurality (two in the illustrated example) of phase detectors (detectors) 7. The phase detector 7 performs filtering with reference to the period set for each light source 1, and outputs the amount of signal light corresponding to each light source 1 to the A / D converter 9. The A / D converter 9 converts the detected light amount of the signal light into digital and outputs it to the optical measurement control device 10.

  Here, the near-infrared light irradiated to the subject 4 is a mixture of two or three wavelengths from among wavelengths of 600 to 1200 nm in order to obtain the respective amounts of oxygenated hemoglobin and deoxygenated hemoglobin. And irradiated. In order to discriminate and detect these wavelengths by the photodetector 6, a method of sequentially lighting the signal light from the plurality of light sources 1 so as not to overlap, or each light source 1 blinks at a different frequency, A method of filtering by the blinking frequency is adopted.

  In the case of the method of filtering at the blinking frequency, as many phase detectors 7 as the number of the light sources 1 detected by the photodetector 6 are prepared. For example, a total of six phase detectors 7 for the light sources 1A, 1B, 1C, 1D, 1E, and 1F are prepared as the photodetectors 6A. In addition, a total of six phase detectors 7 for the light sources 1E, 1F, 1G, 1H, 1I, and 1J are prepared as the photodetectors 6B. For example, eight phase detectors 7 are prepared in one photo detector 6 at the maximum. Note that the phase detector 7 is not required when there are two types of wavelengths and when the light source is sequentially turned on.

  The optical measurement control device 10 controls the light intensity of each light source 1, the amplification degree of the photodetector 6, and the like via the driving device 8, and also controls from the start to the end of the optical biological measurement. The optical calculation device 11 uses the detected light amount of each light source output from the A / D converter 9 to detect the subject from two or three pairs of near infrared light passing through the same portion of the subject 4. The amount of change in oxygenated / deoxygenated hemoglobin and total hemoglobin in 4 is calculated. The optical measurement data obtained as a result of the calculation is displayed as a numerical value or an image on the monitor 12 as a display device, and also stored in the memory 13. The stimulus presentation device 21 is a device that is provided near the head of the subject 4, for example, and that stimulates the subject 4 with sound or video.

  On the other hand, the electroencephalogram measurement apparatus includes an electroencephalogram electrode 30 installed on the head of the subject 4, an electroencephalogram reception apparatus 31, and an electroencephalogram calculation apparatus 32. The electroencephalogram receiver 31 receives the change in the electroencephalogram detected by the electroencephalogram electrode 30, displays it on a monitor (not shown), and outputs it to the electroencephalogram calculator 32. The electroencephalogram calculation device 32 detects electroencephalograms such as θ waves and β waves based on the input electroencephalograms, and detects the state of the subject 4 such as physical condition (for example, sleepiness) based on them. Calculation results such as the magnitude or ratio of the θ wave and β wave obtained by the electroencephalogram calculation device 32 are output to the display screen 22 which is a result presentation device provided in the stimulus presentation device 21. The stimulus presentation device 21 outputs a trigger signal 23 to the optical measurement control device 10 when the magnitude or ratio of an input θ wave, β wave, or the like exceeds or falls below a set value to measure optical topography. Stop, pause, and start are controlled.

  That is, in optical measurement, it is desired to optically measure the relationship with the timing at which an auditory or visual stimulus is applied to the subject 4 by the stimulus presentation device 21, for example, a change in brain function before and after the stimulus is applied. Therefore, in the present embodiment, the optical measurement control device 10 can control the start, pause, and stop of the optical measurement by the trigger signal 23 output from the stimulus presentation device 21 according to the state of the subject 4 and the like. I am doing so.

  The operation and usage of the present embodiment configured as described above will be described in detail below. First, when optically measuring the brain activity state, it is necessary to satisfy the measurement conditions such as managing the brain activity state and the motion state of the subject 4 to be constant or a desired state. Hereinafter, the operation and use state of this embodiment will be described by dividing into measurement modes according to the optical measurement conditions. In addition, the following measurement modes can be operated or used independently or in combination of a plurality of modes as appropriate.

(Subject alert mode)
When optically measuring the activity state of the brain, it is necessary to call attention so that the subject 4 does not sleep, for example, as an example for maintaining and measuring the brain activity state and movement state of the subject 4 in a certain state. There is. In this case, as shown in FIG. 2, a warning image is presented on the display screen 22 of the stimulus presentation device 21. A curve 101 in FIG. 9A shows a temporal change in the arousal level of the subject 4 calculated by the electroencephalogram calculation device 32. A line 102 in FIG. 5A is a determination threshold for alerting the degree of arousal. In the period B in the figure where the arousal level is below the determination threshold, the warning lamp 104 is turned on as shown in FIG. 5B, and in the period A in the figure above the determination threshold, the warning is issued. The lamp 104 for is turned off. As a result, the optical measurement conditions can be maintained within a certain allowable range.

  FIG. 3 shows an example of a procedure for calculating the arousal level in the electroencephalogram calculation device 32, determining the arousal level, and presenting an alert. As shown in FIG. 3, the electroencephalogram calculation apparatus 32 measures the electroencephalogram implanted from the electroencephalogram reception apparatus 31 in real time (S1), and performs Fourier transform on the electroencephalogram data in the immediately preceding predetermined section (sampling period) for each sampling period. (S2). Next, the signal intensity of the θ wave (4 to 7 Hz component) in the electroencephalogram where the subject appears to sleep and slumber is obtained (S3). The obtained θ wave is displayed on the display screen 22 of the stimulus presentation device 21 as the arousal level as necessary. Next, it is determined whether or not the signal intensity of the θ wave exceeds a preset determination threshold (S5). If not exceeded, a warning message is displayed on the display screen 22 to alert the subject (S6). When the signal intensity of the θ wave exceeds the determination threshold, no alert is displayed on the display screen 22.

  Here, factors that prompt the attention of the subject include not only the arousal level but also the attention intensity that can be measured by an electroencephalogram or the body movement that can be measured by a myoelectric signal described later. In addition, it is preferable that the alerting method is performed by displaying an image on the display screen 22 when the response of the brain to sound is measured, and by sound when the response of the brain to vision is measured. Furthermore, the alerting can be made visually, for example, by an alarm sound intensity or frequency change, a tactile sense (temperature) change, or a reminder image or a calculation result graph.

  In this way, the brain wave calculation result is presented on the display screen 22 in the stimulus presentation device 21, and the drowsiness, attention intensity, etc. are fed back to the subject 4 to maintain the desired activity of the brain, For example, it is possible to perform brain function measurement by optical measurement in the “awake state”. As a result, the waste of the acquired optical measurement data can be reduced, and the calculation load of optical measurement can be reduced.

  In the example shown in FIGS. 2 and 3, the case of using the brain wave θ wave has been described, but it is possible to call attention in the same manner using a β wave (14 to 33 Hz). That is, the β wave has a high degree of tension and is in a state of high attention and cognitive power, and the β wave is generated when performing matters requiring attention. It should be noted that an α wave is generated when concentrated on a movie or television, but since this α wave is passive attention, it is different from the attention used in brain function measurement. On the other hand, since the attention of the β wave is positive, it is preferable to use the change of the β wave to evaluate the attention.

(Optical measurement control mode 1 according to the brain state)
In general, in optical measurement, optical measurement data is collected over a plurality of sampling periods and added to reduce noise included in the measurement data. Therefore, the measurement time under the same measurement condition becomes long, and if the brain state changes during that time, the collected optical measurement data may be wasted. Therefore, in the present embodiment, the electroencephalogram data 34 is sent from the electroencephalogram calculation device 32 to the optical calculation device 11, and the optical measurement data sampled according to the brain activity state in the optical calculation device 11 can be selected. .

  A curve 101 in FIG. 4A shows a temporal change in the arousal level (attention intensity) of the subject 4 calculated by the electroencephalogram calculation device 32. A line 102 in FIG. 10A is a determination threshold value for alerting the degree of arousal (attention intensity). Further, a curve 105 in FIG. 5B represents a time change of the optical measurement data calculated by the optical calculation device 11. Then, in the electroencephalogram calculation device 32 or the optical calculation device 11, the attention intensity is determined according to the processing procedure shown in FIG. 5, and the optical measurement data is selected. First, the brain wave data in an arbitrary measurement section A is Fourier transformed (S11). Next, the signal intensity of the θ wave (4 to 7 Hz component) in the electroencephalogram where it appears that the subject is asleep and dizzy is obtained (S12). It is determined whether or not the obtained signal strength of the θ wave exceeds a preset determination threshold value (S13). If the signal intensity of the θ wave exceeds the determination threshold, the section A is set as the optical measurement data addition section (S14), and if not, the section A is excluded from the optical measurement data addition section (S15). The process moves to the next section (S16). That is, the optical measurement data sampled in the sections 106 and 107 in FIG. 4 where the attention intensity exceeds the determination threshold 102 is added, and the optical measurement data in the sections other than the sections are discarded without being added.

  In this case, when storing the optical measurement data in the memory 13, markers indicating the base points and end points of the addition sections 106 and 107 are added and stored. In addition, since the θ wave is in a slumbering state, if it does not occur halfway, there is a possibility of a good sleep, so it may be better to evaluate the δ wave (1.5 to 4 Hz).

  Therefore, according to this optical measurement control mode 1, optical measurement data that deviates from the measurement conditions can be discarded, so that the accuracy of optical measurement can be improved. In addition, the number of repeated measurements for improving measurement accuracy can be reduced, and the substantial measurement time can be shortened.

  Further, as described in the example of FIG. 3, the optical measurement data can be selected by determining the attention intensity based on the β wave instead of the θ wave of FIG. 5. FIG. 6 illustrates each waveform diagram when optical measurement data is selected based on other brain waves. FIG. 4A shows an electroencephalogram waveform diagram, FIG. 2B shows an example of an electroencephalogram in a specific frequency band included in the electroencephalogram, and FIG. 3C shows an example of an optical measurement data waveform. As shown in the figure, when the electroencephalogram in the specific frequency band falls below the determination threshold 108, the optical measurement data is discarded and the optical measurement data of the other sections 109 and 109 are added.

(Optical measurement control mode 2 according to the brain state)
Some brain diseases have uncertain times of onset, such as epilepsy. It is important to observe the brain state before and after the seizure of such a brain disease, but since it is not known when it will occur, it is necessary to perform optical measurements over a long period of time. There is a problem that the burden is large. In addition, a large amount of optical measurement data must be stored for a long time, and a storage device having a huge storage capacity is required.

  Therefore, when an epileptic seizure is detected based on the diagnosis result of the electroencephalogram calculation device 32, a trigger signal 35 shown in FIG. 1 is sent to the optical measurement control device 10. When the optical measurement control device 10 receives the trigger signal 35, the optical measurement control device 10 stores optical measurement data for a certain period before that in the memory 13. Thereby, the storage capacity of the memory 13 can be saved. In addition, the electroencephalogram calculation device 32 sends the detection of the epileptic seizure to the stimulus presentation device 21 and displays that fact on the display screen 22.

  As described above, according to the embodiment of FIG. 1, the oxygenation / deoxygenation hemoglobin and the total amount in the brain of the subject 4 before and after the subject 4 is given a stimulus such as hearing or vision. The brain function can be measured by observing the change in the brain state, for example, by determining the amount of change in hemoglobin and imaging it.

  In particular, it is possible to perform brain function measurement by optical topography in a state in which a desired activity or the like of the brain is maintained, for example, in a “wake state”. As a result, the waste of the acquired optical measurement data can be reduced, and the calculation processing load of optical measurement can be reduced.

Moreover, since the optical measurement result is calculated by selecting the optical measurement data that matches the measurement condition, the accuracy of the optical measurement can be improved.
[Embodiment 2]
FIG. 7 shows an overall configuration diagram of another embodiment of the biological signal processing apparatus of the present invention. This embodiment is different from the embodiment shown in FIG. 1 in that a body motion detection device is coupled in addition to or instead of the electroencephalogram measurement device. Since the other points are the same as those in the embodiment of FIG. 1, the same reference numerals are given to the respective parts and the description thereof is omitted.

  The body movement detection device includes a myoelectric electrode 40 attached in contact with the neck of the subject 4, a myoelectric receiving device 41 that receives a myoelectric signal detected by the myoelectric electrode 40, and myoelectric reception. A body motion calculation device 42 that calculates body motion based on the myoelectric signal received by the device 41 is provided. The body motion calculation device 42 can feed back to the subject 4 by detecting that the subject 4 has moved the head and displaying it on the display screen 22 of the stimulus presentation device 21, for example. For example, as shown in FIG. 8, a waveform is displayed as a time change of the body movement amount 111 with a time change of the electroencephalogram 110.

  According to the present embodiment, as with the degree of arousal (attention intensity) of the electroencephalogram, compared with a determination threshold value (corresponding to 102 in FIG. 2) corresponding to a preset allowable amount of body movement, It is possible to realize the operation or use mode corresponding to the alert mode and the light measurement control modes 1 and 2 depending on the brain state. Conversely, the state of the brain when it moves can also be optically measured.

  That is, in the alert mode of the subject based on the amount of body movement, as shown in the processing procedure of FIG. 3, the myoelectricity is measured in real time, the amount of body movement is obtained from the myoelectric data of the immediately preceding sampling cycle, and the amount of body movement is It is determined whether or not the determination threshold is exceeded. If it exceeds, a warning such as “Do not move” is presented on the display screen 22, for example. The waveforms of the myoelectric signal 112, the amount of body movement 113, and the optical measurement data 114 at this time are shown in FIGS. As shown in the figure, it is determined whether or not the amount of body movement 113 obtained by integrating the myoelectric signal 112 exceeds the determination threshold value 115. For the sections 116 and 116 where the optical measurement data is not exceeded, the optical measurement data is discarded. Add optical measurement data.

Further, as in the processing procedure of FIG. 5, the amount of body movement is obtained from the myoelectric data of the section A, it is determined whether or not the body movement amount exceeds the determination threshold, and the optical measurement data of the section A is excluded from the addition section. When the threshold value is not exceeded, the process of setting the section A as the addition section is performed for each section. Thereby, the accuracy of optical measurement can be improved by selecting the optical measurement data that matches the measurement conditions and calculating the optical measurement result.
(Specific example of optical measurement control mode based on body movement)
FIG. 10 shows an example of processing in a measurement mode specific to body movement. In the case of an infant, the task (movement, etc.) may not be started at the signal of the examiner. In this case, the movement of the mouth or hand is detected from the myoelectric signal, and a period in which the movement is equal to or greater than a certain threshold can be regarded as the task period. However, sections in which body movement is very large and it is difficult to measure brain function by optical measurement can be excluded from the measurement data. That is, as shown in FIG. 10, the amount of body movement is obtained from the electromyogram data of section A (S21). Next, it is determined whether the calculated body movement amount exceeds the first determination threshold value Ta (S22). If it exceeds, the optical measurement data of the section A is excluded from the addition section (S24). On the other hand, if the body movement amount does not exceed the determination threshold Ta, it is determined whether or not the second determination threshold Tb (where Ta> Tb) is exceeded (S23). If the body movement amount exceeds Tb, that is, if Tb <body movement amount <Ta, the optical measurement data in the section A is set as the addition section (S25). On the other hand, if the amount of body movement does not exceed Tb, the process proceeds to step S24, and the optical measurement data of the section A is excluded from the addition section. After completing these processes, the process proceeds to the next section (S26).

It should be noted that instead of step S21 in FIG. 10, myoelectricity is measured in real time to determine the amount of body movement, and in steps S24 and S25, if Tb <body movement amount <Ta, an image that the infant likes is a stimulus presentation device. 21. When the body movement amount> Ta and the body movement amount <Tb, the image that the infant does not like can be displayed on the display screen 22. That is, in order to maintain body movement at present, an image that the infant likes is displayed. When it is desired to suppress the body movement, an animation with a slow tempo is displayed, and when it is desired to increase the body movement, an animation with an up-tempo and relatively unfavorable is displayed.
[Embodiment 3]
FIG. 11 shows an overall configuration diagram of still another embodiment of the biological signal processing apparatus of the present invention. This embodiment is different from the embodiment in FIG. 1 in that an eye-opening monitor 50 is provided. Since the other points are basically the same as those in the embodiment of FIG. 1, the same reference numerals are given to the respective parts and the description thereof is omitted.

  Since the amount of α wave in the brain wave is reduced by eye opening, in order to improve the measurement accuracy of α wave, the measured value of α wave is different between when the eye is open and when it is closed. It is necessary to change the evaluation. This is particularly necessary when measuring the brain function of infants. Therefore, in the present embodiment, an eye opening monitor 50 for detecting the open / closed state of the eyes is provided, and the detection signal 51 of the eye opening monitor 50 is input to the electroencephalogram calculation device 32.

  The eye-opening monitor 50, for example, takes an image of an eyeball in real time with a CCD camera or the like, and detects the degree of opening and closing using the area of the black eye as an evaluation function. That is, as shown in FIGS. 12B, 12C, and 12D, the open eye state is divided into a plurality of stages, such as a state where the eyes are closed, a state where the eyes are half open, and a state where the eyes are fully open. Based on a plurality of data obtained by measuring wave intensity in advance, a calibration curve 120 shown in FIG.

  Thereby, according to this Embodiment, since the alpha wave can be calibrated according to an open eye state in the electroencephalogram calculation apparatus 32, the measurement precision of alpha wave can be improved. As a result, the content presented by the stimulus presentation device 21 can be made appropriate.

Although not shown, as in FIG. 1, the electroencephalogram data 34 can be sent from the electroencephalogram computation device 32 to the optical computation device 11 and reflected in the control of the optical measurement control modes 1 and 2 described above. In addition, the trigger signal 35 can be output to the optical measurement control device 10 based on a detection signal such as a seizure of a brain disease.
[Embodiment 4]
Here, in the biological signal processing apparatus of the embodiment shown in FIG. 1 or FIG. 11, it is preferable to coordinate measurement control because there is a difference in measurement principle between optical measurement and electroencephalogram measurement. That is, both optical measurement and electroencephalogram measurement measure changes in brain function with respect to a stimulus, but in order to improve the accuracy of the measurement value, a plurality of sampling data is added to one stimulus.

  However, due to the difference in measurement principle, as shown in FIG. 13, in the case of a typical evoked electrometer (ERP) used for electroencephalogram measurement, the interval for applying stimulation (stimulus interval) is, for example, 0.1 to 1 second. The required number of additions is 20 to 200 times, whereas in the case of optical measurement, the stimulation interval is 15 to 30 seconds and the required number of additions is 5 to 10 times. In other words, in the case of an electroencephalogram, the reaction can be detected within a few tens of milliseconds after the stimulus is applied, whereas in the case of optical measurement that measures changes in blood hemoglobin concentration, the blood state changes after the stimulus is applied. This is because it takes 10 to 15 seconds or more.

  Therefore, in the present embodiment, as shown in FIG. 14, in the case where the stimulation period S and the rest (rest) period R are alternately measured repeatedly, while one stimulation 130 is repeatedly given at a stimulation interval of 1 second, The electroencephalogram measurement can be added 100 times, and the optical measurement is set so that one stimulus presentation period 20 seconds can be added 5 times. Thereby, cooperation with optical measurement and electroencephalogram measurement can be taken. This coordinated measurement can be realized by the sampling pulse generation means shown in FIG. That is, as shown in the figure, the clock pulse generated from the clock pulse generator 60 is divided into clock pulses suitable for brain wave measurement by the first frequency divider 61 and supplied to the sampler 62 for brain wave measurement. To do. Further, the clock pulse frequency-divided by the first frequency divider 61 is further frequency-divided by the second frequency divider 63 and supplied to the optical measurement sampling device 64. Accordingly, as shown in FIG. 16, sampling pulses 131 and 132 are output from the sampling device 64 and the sampling device 62, respectively, and the optical measurement data and the electroencephalogram data are sampled at the set timing.

  FIG. 17 shows another embodiment of measurement cooperative control. In this embodiment, the same stimulus is used for the light measurement and the brain wave measurement, and the stimulus is applied once for each light measurement and brain wave measurement. The stimulation time of the light measurement 135 is minimized, and a response to one stimulation is measured. The stimulation of the electroencephalogram measurement 136 also adds a stimulus between the optical measurement 135 and the optical measurement 135 to increase the number of measurements. The necessary rest time is secured before and after the light measurement stimulus.

  In this way, by coordinating the measurement between the optical measurement and the electroencephalogram measurement, the brain function measurement by the optical measurement and the electroencephalogram measurement can be associated in a short time without impairing the measurement characteristics of the two. Can contribute to the advancement of science and brain medicine.

1 is an overall configuration diagram of an embodiment of a biological signal processing apparatus of the present invention. It is a figure explaining the stimulus presentation of the alerting by an electroencephalogram. It is a flowchart of the processing procedure of alerting by an electroencephalogram. It is a figure explaining the control of the optical measurement by an electroencephalogram. It is a flowchart of the process sequence of the optical measurement by an electroencephalogram. It is a figure explaining the control of the optical measurement by an electroencephalogram. It is a whole block diagram of other embodiment of the biosignal processing apparatus of this invention. It is a figure explaining the relationship between an electroencephalogram and a body motion. It is a figure explaining the relationship between a myoelectric signal, a body movement amount, and optical measurement. It is a flowchart of the process sequence of the optical measurement by a body movement. It is a whole block diagram of other embodiment of the biosignal processing apparatus of this invention. It is a figure explaining the relationship between the degree of eye opening, and an alpha wave. It is a figure explaining the difference in the measurement characteristic of optical measurement and electroencephalogram measurement. It is a time chart which shows the measurement timing of one Embodiment of an optical measurement and an electroencephalogram measurement. It is a block diagram of the sampling pulse production | generation means of optical measurement and an electroencephalogram measurement. It is a time chart of the sampling pulse generated by the sampling pulse generation means of FIG. It is a time chart which shows the measurement timing of other embodiment of an optical measurement and an electroencephalogram measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Optical coupler 4 Subject 6 Optical detector 7 Detector 10 Optical measurement control apparatus 11 Optical arithmetic device 12 Monitor 13 Memory 21 Stimulus presentation device 22 Display screen 23 Trigger signal 30 Electroencephalogram electrode 31 Electroencephalogram receiver 31 Electroencephalogram arithmetic device 33 EEG data 34 EEG data 35 Trigger signal

Claims (7)

  An optical measurement device that measures transmitted light or reflected light of the light irradiated on the head of the subject, and obtains optical characteristics in the head based on the optical measurement data, and a stimulus presentation device that applies a stimulus to the subject A biological signal processing device comprising: a biological activity measurement device that measures a biological signal correlated with the activity of the subject; and the stimulus presentation device is based on the biological signal measured by the biological activity measurement device A biological signal processing apparatus for controlling the stimulation.   The biological activity measurement device is an electroencephalogram measurement device that measures an electroencephalogram of the subject, and the stimulus presentation device controls the stimulation according to the intensity of a θ wave or a β wave output from the electroencephalogram measurement device. The biological signal processing apparatus according to claim 1.   The biological activity measurement device is a body motion measurement device that measures the movement of muscles of the subject, and the stimulus presentation device controls the stimulation according to the amount of body motion output from the body motion measurement device. The biological signal processing apparatus according to claim 1.   An optical measurement device that measures transmitted light or reflected light of the light irradiated on the head of the subject, and obtains optical characteristics in the head based on the optical measurement data, and a stimulus presentation device that applies a stimulus to the subject A biological signal processing device comprising: a biological activity measurement device that measures a biological signal correlated with the activity of the subject; and the optical measurement device is based on the biological signal measured by the biological activity measurement device The biological signal processing apparatus is characterized in that the optical characteristics are obtained by selecting the optical measurement data.   The electroencephalogram measurement apparatus is an electroencephalogram measurement apparatus that measures the electroencephalogram of the subject, and the optical measurement apparatus discards the optical measurement data according to the intensity of the θ wave or the β wave output from the electroencephalogram measurement apparatus. The biological signal processing apparatus according to claim 4, wherein the biological signal processing apparatus is selected.   The biological activity measurement device is a body motion measurement device that measures the movement of muscles of the subject, and the optical measurement device discards the optical measurement data according to the amount of body motion output from the body motion measurement device. The biological signal processing apparatus according to claim 4, wherein the biological signal processing apparatus is selected.   The biological signal according to claim 2, wherein an eye opening detection device that measures an eye opening degree of the subject is provided, and the electroencephalogram measurement apparatus calibrates an α wave measured according to the eye opening degree. Processing equipment.

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