JP2017055840A - Optical measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical measurement device capable of grasping a state of an autonomous nerve of a subject without separately adding dedicated hardware.SOLUTION: An optical measurement device 100 includes a plurality of light transmission probes 1 that can irradiate with measurement light a head region-of-interest R of a subject, a plurality of light reception probes 2 that can receive the measurement light of irradiation to the head region-of-interest R, brain activity measurement means (measurement part 10) for measuring the head region-of-interest R by a head measurement channel composed of the plurality of light transmission probes 1 and the plurality of light reception probes 2, and pulse wave measurement means (measurement part 10) for measuring a pulse wave of the subject by a pulse wave measurement channel composed using a part of the plurality of light transmission probes 1 and the plurality of light reception probes 2. The brain activity measurement means and the pulse wave measurement means are configured so as to perform the measurement concurrently.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical measurement device, and more particularly to an optical measurement device that measures brain activity of a subject.

  Conventionally, an optical measurement device that measures the brain activity of a subject is known. (For example, refer to Patent Document 1).

  Patent Document 1 includes a plurality of light transmission terminals for irradiating measurement light to a subject's head and a light-receiving terminal for receiving measurement light irradiated on the head, and uses near infrared spectroscopy (NIRS). An optical measurement device that uses it to measure brain activity is disclosed. In the optical measurement device, a measurement channel is configured by a pair of a light transmission terminal and a light reception terminal, and brain activity data is acquired for each measurement channel.

  Here, in the brain activity measurement, it is known that the state of the subject's autonomic nerve affects the measurement data. For example, when the autonomic nervous function is in an unbalanced state due to fatigue, stress, or autonomic nervous system diseases, data that evaluates the degree of influence of the autonomic nerve in the analysis of brain activity data and considers the magnitude of the effect Analysis may need to be performed.

JP 2009-230 A

  However, the optical measurement device of Patent Document 1 has a problem in that it cannot grasp the state of the subject's autonomic nerve in brain activity measurement. In addition, for example, when measuring the state of the subject's autonomic nerve simultaneously with the measurement by the optical measuring device, it is necessary to separately add dedicated hardware (measuring device) for measuring the state of the autonomic nerve There is. In this case, measurement becomes large and data analysis becomes complicated.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to grasp the state of the subject's autonomic nerve without adding dedicated hardware separately. It is to provide a possible optical measurement device.

  In order to achieve the above object, an optical measurement device according to one aspect of the present invention is configured to irradiate a head region of interest with a plurality of brain measurement light transmission terminals that can irradiate the subject's head region of interest with measurement light. A brain that measures the region of interest of the head using a plurality of brain measurement light receiving terminals that can receive the measured light, and a head measurement channel that includes a plurality of brain measurement light transmission terminals and a plurality of brain measurement light reception terminals. A pulse wave measuring means for measuring a subject's pulse wave by means of an activity measuring means, and a pulse wave measuring channel configured using a part of the plurality of brain measuring light transmitting terminals and the plurality of brain measuring light receiving terminals; The brain activity measuring means and the pulse wave measuring means are configured to measure in parallel.

  In the optical measurement device according to one aspect of the present invention, as described above, the pulse wave measurement channel configured using a part of the plurality of brain measurement light transmission terminals and the plurality of brain measurement light reception terminals, A pulse wave measuring means for measuring the pulse wave of the subject is provided, and the brain activity measuring means and the pulse wave measuring means are configured to measure in parallel. Thereby, the pulse wave measurement for grasping the state of the subject's autonomic nerve can be performed in parallel with the brain activity measurement. In addition, since the pulse wave measurement can be performed by using part of the brain measurement light transmitting terminal and the brain measurement light receiving terminal, it is not necessary to add dedicated hardware (measuring device) separately. As described above, according to the present invention, it is possible to grasp the state of the subject's autonomic nerve without separately adding dedicated hardware.

  In the optical measurement device according to the above aspect, preferably, from the head measurement channel, an arithmetic means for calculating an index for evaluating the balance of the autonomic nervous function based on the pulse wave data measured from the pulse wave measurement channel It further includes a display unit that displays the measured brain activity data and the calculated index on the same screen. If comprised in this way, the state of a test subject's autonomic nerve can be easily grasped | ascertained with the parameter | index for evaluating the balance of an autonomic-nerve function. Moreover, since the index of the autonomic nerve can be grasped on the screen of the display unit simultaneously with the brain activity data, the influence of the autonomic nerve can be evaluated during the measurement of the brain activity. As a result, for example, when the autonomic nervous function is unbalanced and the influence on the brain activity data is large, various measures such as adjustment of measurement conditions and appropriate treatment (such as taking a rest) on the subject are possible. become able to. Thereby, not only data analysis but also the convenience of the apparatus when performing brain activity measurement can be improved.

  In this case, preferably, the calculation means is configured to calculate an acceleration pulse wave based on the pulse wave data and calculate a ratio between a low frequency component and a high frequency component included in the acceleration pulse wave for a predetermined period as an index. ing. With this configuration, it is easier and more direct based on the ratio of the low-frequency component of the acceleration pulse wave that mainly reflects the sympathetic nerve function and the high-frequency component of the acceleration pulse wave that mainly reflects the parasympathetic nerve function, The state of the subject's autonomic nerve can be grasped. In the present specification, the “ratio between the low frequency component and the high frequency component included in the acceleration pulse wave” is an index (LF / HF) used in the field of the autonomic nervous function, “Low frequency component of acceleration pulse wave” indicates a frequency component of less than 0.15 Hz, and “High frequency component of acceleration pulse wave” indicates a frequency component of 0.15 Hz or more. Generally, the upper limit of the high frequency component is 0.40 Hz to 0.50 Hz. The boundary between the low frequency component and the high frequency component (0.15 Hz) and the upper limit of the high frequency component are not strictly limited to these values, but can be used as an index for evaluating the balance of autonomic nervous function. A different value may be adopted.

  In the optical measurement device according to the above aspect, preferably, the pulse wave measurement means constitutes a pulse wave measurement channel with measurement light having the same wavelength as that of the measurement light from the brain measurement light transmission terminal constituting the head measurement channel. It irradiates from the light transmission terminal for brain measurement. If comprised in this way, both brain activity data and pulse wave data can be acquired with common measurement light. In other words, it is not only necessary to add dedicated hardware (measuring device) separately, but also without using a dedicated light source for pulse wave measurement, using brain light source for brain activity measurement, Can get both.

  In the optical measurement device according to the above aspect, the brain activity measurement unit and the pulse wave measurement unit are preferably configured to acquire measurement data at the same sampling interval. If comprised in this way, based on the measurement data (brain activity data and pulse wave data) acquired at the same sampling interval, without the process etc. which match the time series between data in the analysis of brain activity data, etc. Unified analysis processing is possible. In addition, when dedicated hardware (measurement device) is added separately, it may be difficult to acquire brain activity data and pulse wave data at the same sampling interval due to limitations in hardware specifications. On the other hand, according to the present invention, the brain activity data and the pulse wave data can be easily acquired at the same sampling interval by providing the brain activity measuring means and the pulse wave measuring means in the same device. Therefore, the convenience of the apparatus can be improved.

  In the optical measurement device according to the above aspect, preferably, the pulse wave measurement unit configures the pulse wave measurement channel at the same timing as the measurement light irradiation timing from the brain measurement light transmission terminal that configures the head measurement channel. It is comprised so that measurement light may be irradiated from the light transmission terminal for brain measurement. If comprised in this way, when measuring the pulse wave measurement channel in addition to the measurement of the head measurement channel, the measurement can be performed without increasing the total cycle time of the measurement light irradiation cycle. In other words, in the head measurement channel, the measurement channels are concentrated in the head region of interest, so the irradiation timing of the measurement light is shifted for each brain measurement light transmission terminal so that the measurement light is not mixed into another head measurement channel. Sometimes. In contrast, the pulse wave measurement channel can be measured with fingers or earlobes that are separated from the head measurement channel, and the measurement light is not mixed into another channel. It is possible to suppress an increase in the total cycle time by matching.

  In the optical measurement device according to the above aspect, preferably, a plurality of head measurement channels are configured, and one pulse wave measurement channel is configured by a pair of light transmission terminals for brain measurement and a light reception terminal for brain measurement. Yes. With this configuration, the number of head measurement channels that can be measured can be reduced more than necessary even when the pulse wave measurement channel is configured by diverting the brain measurement light transmitting terminal and the brain measurement light receiving terminal. Absent. As a result, a sufficient number of brain activity data can be acquired while acquiring pulse wave data.

  In the optical measurement device according to the above aspect, preferably, a head measurement holder for holding a brain measurement light transmitting terminal and a brain measurement light receiving terminal at a head measurement position corresponding to a head region of interest, and a brain measurement A pulse wave measurement holder that holds the light transmission terminal and the light receiving terminal for brain measurement at the pulse wave measurement position of the subject, and the light transmission terminal for brain measurement and the light reception terminal for brain measurement are each a head measurement holder And the pulse wave measurement holder are detachable. If comprised in this way, without using a specific light transmission terminal for brain measurement and a light reception terminal for brain measurement as a dedicated terminal for pulse wave measurement, arbitrary and general-purpose terminals can be attached to and detached from the respective holders. be able to. As a result, the brain measurement light transmitting terminal and the brain measurement light receiving terminal can be freely selected during brain activity measurement, so that the convenience of the apparatus can be improved.

  According to the present invention, as described above, it is possible to grasp the state of the subject's autonomic nerve without separately adding dedicated hardware.

It is the schematic diagram which showed the whole structure of the optical measuring device by one Embodiment of this invention. It is a schematic diagram for demonstrating a head measurement channel and a head measurement holder. It is the schematic diagram which showed an example of the probe arrangement | positioning to the head measurement holder. It is a schematic diagram for demonstrating a pulse wave measurement channel and a holder for pulse wave measurement. It is the figure which showed an example of the lighting protocol of each light transmission probe. It is a conceptual diagram for demonstrating the process which calculates an parameter | index based on pulse wave data. It is a figure which shows an example of the display screen of a display part. It is a figure for demonstrating the parameter | index for evaluating the balance of an autonomic-nerve function. It is a flowchart for demonstrating the measurement process of the optical measuring device by one Embodiment of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  First, with reference to FIGS. 1-7, the whole structure of the optical measuring device 100 by one Embodiment of this invention is demonstrated.

[Configuration of optical measuring device]
First, an outline of brain activity measurement by the optical measurement device 100 will be described. The optical measurement device 100 is a device that optically measures a subject's brain activity using near infrared spectroscopy (NIRS) and generates time-series measurement result data.

  Specifically, as shown in FIG. 1, the optical measurement device 100 includes a head region of interest R from a light transmission probe 1 in which measurement light in the near infrared wavelength region is arranged on the head surface of the subject. Irradiate. Then, the measurement light intensity (the amount of received light) is acquired by causing the measurement light applied to the head region of interest R to be incident on the light receiving probe 2 disposed on the head surface. The light transmission probe 1 is an example of the “brain measurement light transmission terminal” in the claims. The light receiving probe 2 is an example of the “light receiving terminal for brain measurement” in the claims.

  The optical measurement device 100 is based on the intensity (light reception amount) of measurement light of a plurality of wavelengths (for example, three wavelengths of 780 nm, 805 nm, and 830 nm) in the near infrared region (approximately 700 nm to 2500 nm) and the absorption characteristics of hemoglobin. Changes in oxygenated hemoglobin, deoxygenated hemoglobin, and total hemoglobin are measured. That is, the optical measurement device 100 measures the hemoglobin change amount in the head region of interest R as a brain activity that reflects a change in blood flow in the brain accompanying the brain activity. The head region of interest R is set according to the measurement purpose and is not particularly limited. For example, in the measurement of brain activity related to cognitive function, the frontal lobe (frontal cortex) is mainly set as the head region of interest R.

  In addition to the brain activity measurement, the optical measurement device 100 according to the present embodiment is configured to measure a subject's pulse wave.

  As shown in FIG. 1, the optical measurement device 100 includes a measurement unit 10, a main body control unit 11, and a main storage unit 12. The measurement unit 10 includes a light output unit 13, a light detection unit 14, and a measurement control unit 15. The optical measuring device 100 includes a display unit 16 and an operation input unit 17. In addition, the optical measurement device 100 includes a plurality of light transmitting probes 1 that can irradiate the subject's head region of interest R with measurement light, and a plurality of light receiving probes 2 that can receive the measurement light that has been irradiated to the head region of interest R. With. The measuring unit 10 is an example of “brain activity measuring means” and “pulse wave measuring means” in the claims. The main body control unit 11 is an example of the “calculation unit” in the claims.

  The measurement unit 10 has a function of configuring a measurement channel by a pair of the light transmission probe 1 and the light reception probe 2 and performing measurement using the measurement light for each measurement channel. Specifically, the measuring unit 10 is a brain activity measuring unit that measures a head region of interest R by a head measuring channel 21 (see FIG. 2) configured by a plurality of light transmitting probes 1 and a plurality of light receiving probes 2. The pulse wave measurement that measures the pulse wave of the subject by the pulse wave measurement channel 22 (see FIG. 4) configured using a part of the plurality of light transmitting probes 1 and the plurality of light receiving probes 2. Functions as a means.

  The light output unit 13 is configured to output measurement light to the light transmission probe 1 via the optical fiber 3. The light output unit 13 includes a semiconductor laser or the like as a light source, and outputs the above-described measurement light having a plurality of wavelengths in the near infrared wavelength region. The light detection unit 14 includes a photomultiplier tube or the like as a detector, and is configured to acquire and detect measurement light incident on the light receiving probe 2 via the optical fiber 3.

  The measurement control unit 15 controls the operation of the light output unit 13 and the light detection unit 14, controls the timing of turning on and off the light output unit 13, and acquires the received light amount signal from the light detection unit 14.

  The main body control unit 11 is a computer composed of a CPU, a memory, and the like, and is configured to control the measurement operation of the optical measurement device 100 by executing various programs stored in the main storage unit 12. .

  In addition, the main body control unit 11 outputs the obtained measurement data to the display unit 16 by executing data analysis software (program). The measurement data is time-series data including time information and measurement value information, and is recorded in the main storage unit 12 for each measurement channel.

  The main storage unit 12 is composed of, for example, an HDD (Hard Disk Drive) and stores various programs executed by the main body control unit 11 and can store measurement data obtained as a result of measurement. The display unit 16 is a display device such as a liquid crystal monitor, for example, and the operation input unit 17 is an input device including a keyboard and a mouse, for example.

  A plurality of light transmitting probes 1 and light receiving probes 2 are provided. In the present embodiment, the optical measurement device 100 includes a head measurement holder 4 that holds the light transmission probe 1 and the light reception probe 2 at a head measurement position corresponding to the head region of interest R, and the light transmission probe 1 and the light reception probe. And a pulse wave measurement holder 5 for holding 2 at the pulse wave measurement position of the subject. The light transmitting probe 1 and the light receiving probe 2 are configured to be detachable from the head measuring holder 4 and the pulse wave measuring holder 5, respectively.

  As shown in FIG. 2, the head measurement holder 4 is configured to be mounted on the head of the subject and includes a plurality of mounting holes 4a for fixing the probe. The light transmitting probe 1 and the light receiving probe 2 are fixed to a predetermined position on the head surface by being attached to the head measuring holder 4. A head measurement channel (measurement point) 21 is formed between the adjacent light transmitting probe 1 and light receiving probe 2. The head measurement channel 21 includes a light transmitting probe 1 and a light receiving probe 2 arranged at a predetermined first interval D1 on the subject's head, and acquires brain activity data 23 (see FIG. 1). It is a measurement channel. The first interval D1 is generally a constant interval of about 3 cm.

  As shown in FIG. 3, in the head measurement holder 4, the light transmitting probes 1 and the light receiving probes 2 are arranged so as to be alternately arranged in, for example, row and column directions. In this case, the head measurement channel 21 can be configured by the light transmitting probe 1 and the light receiving probe 2 adjacent in the row direction and the column direction, and the number of measurement channels per number of probes can be maximized. is there. FIG. 3 shows an example in which 42 head measuring channels 21 are configured by 14 light transmitting probes 1 and 13 light receiving probes 2.

In the present embodiment, the pulse wave measurement channel 22 is configured using a part of the plurality of light transmission probes 1 and the plurality of light reception probes 2. That is,
The light transmitting probe 1 and the light receiving probe 2 are disposed at the pulse wave measurement position of the subject by being attached to the pulse wave measurement holder 5 shown in FIG. A pulse wave measurement channel (measurement point) 22 is formed between the adjacent light transmitting probe 1 and light receiving probe 2. The pulse wave measurement channel 22 is a measurement channel for acquiring the pulse wave data 24 (see FIG. 6) of the subject.

  The pulse wave measurement holder 5 employs a different structure depending on the pulse wave measurement site of the subject. The pulse wave measurement site can be, for example, the finger of the subject or the earlobe of the subject. FIG. 4 shows an example of measuring a so-called finger plethysmogram using a subject's finger as a pulse wave measurement site.

  In this case, the pulse wave measurement holder 5 includes a cylindrical portion 5a having a cylindrical shape into which a subject's finger (for example, index finger) can be inserted. A mounting hole 5b for fixing the probe at the pulse wave measurement position of the subject is formed in the pulse wave measurement holder 5 so as to penetrate the cylindrical part 5a from the outer peripheral part to the inner peripheral part. The pulse wave measurement holder 5 includes two mounting holes 5b, and the light transmitting probe 1 and the light receiving probe 2 are mounted one by one. Therefore, in this embodiment, the pulse wave measurement channel 22 is configured by one pair (one channel) of the pair of light transmission probe 1 and light reception probe 2.

  The light transmitting probe 1 and the light receiving probe 2 (that is, the two attachment holes 5b) are arranged with a predetermined second interval D2. The second distance D2 is, for example, about 10 mm. Thereby, measurement light is irradiated from the light transmitting probe 1 into the tissue of the fingertip, and the measurement light that has passed through the tissue is received by the light receiving probe 2. Since the measurement light is absorbed according to the blood flow in the tissue, the measurement signal of the pulse wave measurement channel 22 is pulse wave data 24 (finger plethysmogram) reflecting changes in blood flow accompanying pulsation. Get as.

  With such a configuration, in the configuration example shown in FIGS. 3 and 4, brain activity data is obtained from the 42 head measurement channels 21 constituted by 14 light transmitting probes 1 and 13 light receiving probes 2. 23 is acquired, and pulse wave data 24 is acquired from the 43rd pulse wave measurement channel 22 constituted by each one light transmitting probe 1 and light receiving probe 2.

(Overview of measurement)
Next, an outline of measurement in the head measurement channel 21 and the pulse wave measurement channel 22 will be described.

  In the present embodiment, the optical measurement device 100 performs the measurement of the brain activity data 23 from the head measurement channel 21 and the measurement of the pulse wave data 24 from the pulse wave measurement channel 22 in parallel under common measurement conditions. It is configured to be implemented. The measurement conditions include the wavelength of measurement light used for measurement and the sampling interval of measurement data.

  That is, the measurement unit 10 is configured to irradiate measurement light having the same wavelength as measurement light from the light transmission probe 1 constituting the head measurement channel 21 from the light transmission probe 1 constituting the pulse wave measurement channel 22. ing. As described above, the brain activity data 23 is acquired using measurement light having a plurality of wavelengths (for example, three wavelengths of 780 nm, 805 nm, and 830 nm). The measurement unit 10 also controls the light transmission probe 1 of the pulse wave measurement channel 22 to irradiate measurement light having the same plurality of wavelengths from the light output unit 13. In other words, the optical measurement device 100 acquires the pulse wave data 24 using a common light source (light output unit 13) used for brain activity measurement without providing a dedicated light source for pulse wave measurement.

  For example, in the probe arrangement of FIG. 3, when measurement light is simultaneously irradiated from the light transmission probes 1 (for example, the first and fourth light transmission probes) on both sides sandwiching one light receiving probe 2, both measurement lights Will be received, causing interference between measurement channels. Therefore, the measurement unit 10 sequentially performs lighting of each light transmission probe 1 (irradiation of measurement light) by shifting the lighting timing in units of lighting cycles according to a preset protocol.

  FIG. 5 shows a configuration example of the lighting protocol, in which the horizontal axis represents the lighting cycle number, and the vertical axis represents the light transmission probe number. In FIG. 5, the light transmission probe 1 of the head measurement channel 21 shown in FIG. 3 is set to No. 1 to No. 14, and the light transmission probe 1 of the pulse wave measurement channel 22 is set to No. 15. In the configuration example of FIG. 5, the number of lighting cycles is 14. That is, for each lighting cycle, the light transmitting probes 1 of the head measurement channel 21 are sequentially turned on one by one from No. 1 to No. 14.

  Here, the light transmission probe 1 of the pulse wave measurement channel 22 is turned on simultaneously (in the same lighting cycle) with the 14th light transmission probe 1 of the head measurement channel 21 in the 14th lighting cycle. That is, in the present embodiment, the measurement unit 10 measures from the light transmission probe 1 that configures the pulse wave measurement channel 22 at the same timing as the measurement light irradiation timing from the light transmission probe 1 that configures the head measurement channel 21. It is comprised so that light may be irradiated.

  This is because interference between the measurement channels does not occur between the head measurement channel 21 configured on the subject's head and the pulse wave measurement channel 22 configured on the fingertip even if the light is simultaneously turned on. is there. For this reason, the pulse wave measurement channel 22 may be turned on in any lighting cycle other than No. 14.

  Further, in the present embodiment, the measurement unit 10 has both the acquisition of the brain activity data 23 from the head measurement channel 21 and the acquisition of the pulse wave data 24 from the pulse wave measurement channel 22 at the same sampling interval. It is comprised so that measurement data may be acquired.

  The sampling interval is a predetermined time interval such as 75 μsec or 125 μsec, for example, and is preset by the user as one of the measurement conditions. The optical measurement device 100 is configured to be able to select (change) these sampling intervals. For this reason, the brain activity data 23 and the pulse wave data 24 are acquired collectively as time-series measurement data.

  The obtained brain activity data 23 and pulse wave data 24 are recorded in the main storage unit 12. In the present embodiment, the main body control unit 11 calculates an index 25 (see FIG. 1) for evaluating the balance of the autonomic nervous function based on the pulse wave data 24 measured from the pulse wave measurement channel 22. It is configured.

  Specifically, as shown in FIG. 6, the main body control unit 11 calculates the acceleration pulse wave 24 a based on the pulse wave data 24, and the ratio between the low frequency component and the high frequency component included in the acceleration pulse wave for a predetermined period. Is calculated as the index 25. The acceleration pulse wave 24a is a second-order differential wave (pulse wave differentiated twice) of a fingertip pulse wave (fingertip volume pulse wave). “Acceleration” here is not a motion of an object but is commonly used in the meaning of second order differentiation.

  The acceleration pulse wave 24a includes five characteristic components of a wave, b wave, c wave, d wave, and e wave. For the acceleration pulse wave 24a calculated from the pulse wave data 24, the main body control unit 11 sets a predetermined period Dt (a-a interval) from the a wave to the next a wave for a time interval corresponding to one cycle of the acceleration pulse wave 24a. Get as. And the main body control part 11 decomposes | disassembles the acceleration pulse wave 24a for every frequency component by performing a frequency analysis with respect to the acceleration pulse wave 24a within the time window set to the range of this predetermined period Dt. Then, the main body control unit 11 calculates a ratio (LF / HF) between the power of the low frequency component and the power of the high frequency component included in the acceleration pulse wave 24a.

  Here, the low frequency component (LF: Low Frequency) of the acceleration pulse wave 24a is, for example, a frequency component of less than 0.15 Hz, and the high frequency component (HF: High Frequency) of the acceleration pulse wave 24a is a frequency of 0.15 Hz or more. Ingredients. The low frequency component LF mainly reflects the sympathetic nerve function, and the high frequency component HF mainly reflects the parasympathetic nerve function. Therefore, the ratio LF / HF between the low frequency component and the high frequency component can be used as an index 25 representing the balance between the sympathetic nerve and the parasympathetic nerve (balance of autonomic nerve function).

  The obtained index (LF / HF) 25 is stored in the main storage unit 12 and displayed on the display unit 16. As shown in FIG. 7, in this embodiment, the display unit 16 displays the brain activity data 23 measured from the head measurement channel 21 and the calculated index (LF / HF) 25 on the same screen. . The index 25 is displayed as 43 ch measurement data corresponding to the pulse wave measurement channel 22 together with the brain activity data 23 of 1 ch to 42 ch.

(Indicator for evaluating the balance of autonomic nervous function)
From the value of the obtained index (LF / HF) 25, for example, the degree of fatigue of the subject can be evaluated. As shown in FIG. 8, the LF / HF value is about 1.3 to about 1.4 at the normal time when the sympathetic nerve and the parasympathetic nerve are balanced. As HF increases, the HF decreases and the LF / HF value increases (the balance of the autonomic nervous function is lost).

  The imbalance of autonomic nervous function as seen in the degree of fatigue also affects brain activity measurement. Specifically, as shown in FIG. 7, in brain activity measurement, a rest period (rest period) PR in which a set task is not performed and a task period (task period) PT in which a task is performed are generally provided. The brain activity is evaluated as a difference (relative value) between the measurement value of the rest period PR and the measurement value of the task period PT. Therefore, in general, measurement is performed so that the measurement value of the rest period PR is stably lowered to the baseline, but when the subject's degree of fatigue is high, the measurement value is close to the baseline in the rest period PR. There is a case where the difference from the task period PT becomes unclear without being sufficiently lowered.

  Therefore, when analyzing the brain activity data 23, whether or not the fluctuation of the brain activity data 23 is due to the influence of the autonomic nervous system by considering whether or not the balance of the autonomic nerve function is in an appropriate state. It is possible to evaluate whether or not the component evaluated as the influence of the autonomic nervous system is removed as noise of the brain activity data 23, or to analyze the effect of the autonomic nervous system itself.

  During the measurement of the brain activity data 23, the value of the index (LF / HF) 25 is displayed in real time together with the brain activity data 23, so whether or not the value of the index 25 is increasing (autonomic nerves). Whether or not the balance of functions has been lost can be grasped during measurement. Therefore, if there is a concern about the adverse effects of the autonomic nervous system on the brain activity data 23, the measurement conditions such as adjusting the difficulty level of the task in the task period PT and the length of the rest period PR may be reviewed, or if necessary By taking measures such as taking a break, more appropriate brain activity data 23 can be acquired.

(Measurement process of optical measuring device)
Next, the measurement process of the optical measurement device 100 will be described with reference to FIG. The following processing is performed by the main body control unit 11 of the optical measurement device 100 controlling each unit such as the measurement control unit 15 (measurement unit 10).

  Prior to the measurement, a plurality of light transmitting probes 1 and light receiving probes 2 are arranged at measurement positions corresponding to the head region of interest R of the subject via the head measuring holder 4. Further, the finger of the subject is placed inside the pulse wave measurement holder 5, whereby the light transmission probe 1 and the light receiving probe 2 are placed at the pulse wave measurement site (finger). In this state, measurement is performed.

  First, in step S1 of FIG. 9, the main body control unit 11 sets various parameters related to measurement conditions and measurement. Measurement conditions and parameters are acquired, for example, by receiving an input operation via the operation input unit 17 or reading out setting information recorded in advance in the main storage unit 12. Thereby, the main body control unit 11 sets the configuration (probe arrangement) of each measurement channel used for measurement, the lighting cycle protocol, the sampling interval, and the like.

  In step S2, the main body control unit 11 determines whether or not to start measurement. For example, when a measurement start instruction is input via the operation input unit 17, the main body control unit 11 determines that measurement is started, and proceeds to the next step. When the measurement is not started, the main body control unit 11 repeats the determination in step S2 and waits.

  In the present embodiment, when the measurement is started, the body control unit 11 controls the measurement unit 10 so that the brain activity measurement in step S3 and the pulse wave measurement in step S4 are performed in parallel. That is, measurement light is sequentially emitted from the light transmission probe 1 according to the lighting protocol set in step S1 (see FIG. 5), and is received by the respective light reception probes 2, whereby each head measurement channel 21 and pulse wave measurement. Measurement data is acquired from the channel 22. At this time, the brain activity data 23 and the pulse wave data 24 are acquired at a common sampling interval.

  Thereby, in Step S3, measurement part 10 acquires brain activity data 23 (1ch-42ch) of head region of interest R by each head measurement channel 21. In step S <b> 4, the measurement unit 10 acquires the pulse wave data 24 (43ch) of the subject through the pulse wave measurement channel 22. The obtained brain activity data 23 and pulse wave data 24 are recorded in the main storage unit 12.

  Steps S <b> 5 to S <b> 7 are processes for calculating an index 25 (LF / HF) for evaluating the balance of the autonomic nervous function based on the pulse wave data 24. As described above, since the index 25 is calculated based on the data for the predetermined period Dt of the acceleration pulse wave 24a, strictly speaking, the calculation of the index 25 is started from the time when the data for the predetermined period Dt is accumulated. . After the data for the predetermined period Dt is accumulated, the index 25 is calculated each time the pulse wave data 24 is acquired by sliding the time window corresponding to the predetermined period Dt as the pulse wave data 24 is acquired. Is done.

  Specifically, in step S5, the main body control unit 11 calculates the acceleration pulse wave 24a by differentiating the acquired pulse wave data 24 twice. Next, in step S6, the main body control unit 11 extracts a low frequency component (LF) and a high frequency component (HF) of the acceleration pulse wave 24a by frequency analysis of the acceleration pulse wave 24a included in the predetermined period Dt. In step S <b> 7, the main body control unit 11 calculates the ratio (LF / HF) between the low frequency component and the high frequency component as the index 25.

  Next, in step S <b> 8, the main body control unit 11 displays the obtained brain activity data 23 and the index 25 on the display unit 16. That is, as shown in FIG. 7, on the display screen of the display unit 16, the brain activity data 23 from 1ch to 42ch and the 43ch index 25 (LF / HF) as the measurement result of the pulse wave data 24 are simultaneously displayed. Is displayed.

  In step S9, the main body control unit 11 determines whether or not to end the measurement. When the measurement is not finished, the main body control unit 11 returns the process to steps S3 and S4 and continues the measurement. The main body control unit 11 determines to end the measurement when a measurement end instruction is input via the operation input unit 17 or when a preset measurement time has elapsed. In that case, the main body control unit 11 ends the measurement process after executing a predetermined measurement end process in step S10.

  As described above, the measurement process of the optical measurement device 100 is executed.

[Effect of this embodiment]
In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the measurement unit 10 that measures the pulse wave of the subject by the pulse wave measurement channel 22 configured using a part of the plurality of light transmission probes 1 and the plurality of light reception probes 2. And the measurement unit 10 is configured to perform brain activity measurement and pulse wave measurement in parallel. Thereby, the pulse wave measurement for grasping the state of the subject's autonomic nerve can be performed in parallel with the brain activity measurement. Further, since the pulse wave measurement can be performed by using a part of the light transmitting probe 1 and the light receiving probe 2, there is no need to add dedicated hardware (measuring device) separately. As described above, according to the optical measurement device 100 of the present embodiment, the state of the subject's autonomic nerve can be grasped without adding dedicated hardware separately.

  In the present embodiment, as described above, the main body control unit 11 that calculates the index 25 for evaluating the balance of the autonomic nervous function based on the pulse wave data 24 measured from the pulse wave measurement channel 22, the head A display unit 16 for displaying the brain activity data 23 measured from the unit measurement channel 21 and the calculated index 25 on the same screen is provided. Thereby, the state of the subject's autonomic nerve can be easily grasped by the index 25 for evaluating the balance of the autonomic nerve function. In addition, since the autonomic nerve index 25 can be grasped on the screen of the display unit 16 simultaneously with the brain activity data 23, the influence of the autonomic nerve can be evaluated during the measurement of the brain activity. As a result, for example, when the autonomic nerve function is unbalanced and the influence on the brain activity data 23 is large, various measures such as adjustment of measurement conditions and appropriate treatment (such as taking a rest) for the subject are performed. Will be able to. Thereby, not only data analysis but also the convenience of the optical measurement device 100 when performing brain activity measurement can be improved.

  In the present embodiment, as described above, the acceleration pulse wave 24a is calculated based on the pulse wave data 24, and the ratio (LF / HF) between the low frequency component and the high frequency component included in the acceleration pulse wave 24a in the predetermined period Dt. ) Is calculated as the index 25, the main body control unit 11 is configured. Thereby, based on the ratio of the low-frequency component of the acceleration pulse wave 24a that mainly reflects the sympathetic nerve function and the high-frequency component of the acceleration pulse wave 24a that mainly reflects the parasympathetic nerve function, it is easier and more direct. The state of the autonomic nerve can be grasped.

  In this embodiment, as described above, the measurement light having the same wavelength as the measurement light from the light transmission probe 1 constituting the head measurement channel 21 is irradiated from the light transmission probe 1 constituting the pulse wave measurement channel 22. Thus, the measuring unit 10 is configured. Thereby, both the brain activity data 23 and the pulse wave data 24 can be acquired by the common measurement light. That is, it is not necessary to add dedicated hardware (measuring device) separately, and brain activity is measured by using a light source for brain activity measurement (light output unit 13) without providing a light source dedicated to pulse wave measurement. Both the data 23 and the pulse wave data 24 can be acquired.

  In the present embodiment, as described above, the measurement unit 10 is configured to acquire the brain activity data 23 and the pulse wave data 24 at the same sampling interval. Thereby, unified analysis processing becomes possible based on the measurement data (brain activity data 23 and pulse wave data 24) acquired at the same sampling interval. In addition, when dedicated hardware (measuring device) is added separately, it may be difficult to acquire the brain activity data 23 and the pulse wave data 24 at the same sampling interval due to restrictions on hardware specifications. On the other hand, in the present embodiment, the same optical measuring device 100 is configured to perform brain activity measurement and pulse wave measurement, whereby the brain activity data 23 and the pulse wave data 24 can be easily made identical. Therefore, the convenience of the optical measurement device 100 can be improved.

  In the present embodiment, as described above, measurement is performed from the light transmission probe 1 constituting the pulse wave measurement channel 22 at the same timing as the measurement light irradiation timing from the light transmission probe 1 constituting the head measurement channel 21. The measurement unit 10 is configured to emit light. Thereby, in the case of measuring the pulse wave measurement channel 22 in addition to the measurement of the head measurement channel 21, the measurement is performed without increasing the total cycle time of the measurement light irradiation cycle (total number of cycles in FIG. 5). It can be performed. That is, since the pulse wave measurement channel 22 does not mix measurement light into another channel, it is possible to prevent the total cycle time from becoming longer by matching the irradiation timing of the measurement light.

  In the present embodiment, as described above, a plurality of head measurement channels 21 are configured, and one pulse wave measurement channel 22 is configured by a pair of light transmission probe 1 and light reception probe 2. As a result, even when the pulse wave measuring channel 22 is configured by diverting the light transmitting probe 1 and the light receiving probe 2, the number of head measuring channels 21 that can be measured is not reduced more than necessary. As a result, a sufficient number of brain activity data 23 can be acquired while acquiring the pulse wave data 24.

  In the present embodiment, as described above, the head measurement holder 4 that holds the light transmission probe 1 and the light reception probe 2 at the head measurement position corresponding to the head region of interest R, the light transmission probe 1 and the light reception. A pulse wave measurement holder 5 for holding the probe 2 at the pulse wave measurement position of the subject is provided. The light transmitting probe 1 and the light receiving probe 2 are configured to be detachable from the head measuring holder 4 and the pulse wave measuring holder 5, respectively. Thereby, an arbitrary and general-purpose probe can be attached to and detached from each holder without using the specific light transmitting probe 1 and light receiving probe 2 as dedicated terminals (probes) for pulse wave measurement. As a result, the light transmitting probe 1 and the light receiving probe 2 can be freely selected at the time of brain activity measurement, so that the convenience of the optical measuring device 100 can be further improved.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the example in which the pulse wave data 24 is obtained using the finger of the subject as the pulse wave measurement site has been shown, but the present invention is not limited to this. For example, the subject's earlobe may be the pulse wave measurement site. Although not shown, in this case, for example, a clip-shaped pulse wave measurement holder that sandwiches the earlobe from both sides can be used. In the pulse wave measurement holder, the light transmitting probe 1 is held on one side of the earlobe, and the light receiving probe 2 is held on the other side of the earlobe. Thereby, it is possible to acquire pulse wave data by acquiring, from the light receiving probe 2, measurement light that has been irradiated from the light transmitting probe 1 and passed through the earlobe.

  Moreover, in the said embodiment, although the example (refer FIG. 3) which comprised the head measuring channel 21 of 42 points | pieces by 14 light transmission probes 1 and 13 light reception probes 2 was shown, this invention is shown. It is not limited to this. The number of head measurement channels 21 and the arrangement of the light transmitting probe 1 and the light receiving probe 2 are arbitrary and may be set according to the measurement purpose.

  Moreover, in the said embodiment, although the example of the lighting protocol (refer FIG. 5) which lights each light transmission probe 1 which comprises the head measurement channel 21 one by one was shown, this invention is not limited to this. In the present invention, each light transmission probe 1 may be turned on by a lighting protocol other than the pattern shown in FIG.

  Moreover, in the said embodiment, although the example (refer FIG. 4) which comprised the pulse wave measurement channel 22 of 1 point by a pair of light transmission probe 1 and the light reception probe 2, this invention is not limited to this. Two or more pulse wave measurement channels 22 may be configured. However, when the number of pulse wave measurement channels 22 is increased, the number of probes that can be used for the head measurement channel 21 is reduced accordingly. For the purpose of acquiring measurement data for evaluating the balance of autonomic nerve function during brain activity measurement, one pulse wave measurement channel 22 is sufficient, but it may be set according to the measurement purpose.

  In the above embodiment, the index 25 (LF / HF) is calculated based on the pulse wave data 24, and the brain activity data 23 and the index 25 are displayed on the display unit 16 at the same time. It is not limited to this. In the present invention, for example, the brain activity data 23 and the pulse wave data 24 may be displayed, or only the brain activity data 23 may be displayed without displaying the pulse wave data 24 and the index 25. When the index 25 is not displayed, the index 25 may not be calculated during the measurement operation illustrated in FIG. That is, only the pulse wave data 24 may be stored in the main storage unit 12 and the index 25 may be calculated when performing data analysis after the measurement is completed.

  Although FIG. 7 shows an example of a display mode in which the brain activity data 23 and the index 25 are simply arranged, the present invention is not limited to this. The display mode on the display screen of the display unit 16 is not limited to that shown in FIG. 7 and may be arbitrarily changed.

  Moreover, although the said embodiment showed the example which calculates ratio (LF / HF) of the low frequency component contained in the acceleration pulse wave 24a as the parameter | index 25 for evaluating the balance of an autonomic nerve function 24a. The present invention is not limited to this. In the present invention, data other than LF / HF obtained from the pulse wave data 24 may be calculated as long as the data is an index for evaluating the balance of the autonomic nervous function. For example, there is a report that even if the degree of fatigue increases, the LF value does not change so much and the HF value decreases significantly, so the HF value may be calculated as an index.

  Moreover, although the measurement part 10 showed the structural example which functions as both a brain activity measurement means and a pulse wave measurement means in the said embodiment, this invention is not limited to this. For example, the optical measurement device may individually include a measurement unit that functions as a brain activity measurement unit and a measurement unit that functions as a pulse wave measurement unit.

1 Light transmission probe (light transmission terminal for brain measurement)
2 Light receiving probe (light receiving terminal for brain measurement)
4 Head measurement holder 5 Pulse wave measurement holder 10 Measurement unit (brain activity measurement means, pulse wave measurement means)
11 Main body control unit (calculation means)
16 Display unit 21 Head measurement channel 22 Pulse wave measurement channel 23 Brain activity data 24 Pulse wave data 24a Acceleration pulse wave 25 Index 100 Optical measurement device Dt Predetermined period R Head region of interest

Claims (8)

A plurality of brain measuring light transmission terminals capable of irradiating the subject's head region of interest with measurement light;
A plurality of brain light receiving terminals capable of receiving the measurement light emitted to the head region of interest;
Brain activity measuring means for measuring the region of interest of the head by means of a head measurement channel configured by the plurality of brain measurement light transmitting terminals and the plurality of brain measurement light receiving terminals,
A pulse wave measurement means for measuring a subject's pulse wave by a pulse wave measurement channel configured using a part of the plurality of brain measurement light transmitting terminals and the plurality of brain measurement light receiving terminals;
The optical measurement device, wherein the brain activity measurement unit and the pulse wave measurement unit are configured to perform measurement in parallel. Based on the pulse wave data measured from the pulse wave measurement channel, calculation means for calculating an index for evaluating the balance of autonomic nerve function,
The optical measurement device according to claim 1, further comprising: a display unit that displays the brain activity data measured from the head measurement channel and the calculated index on the same screen.   The calculating means is configured to calculate an acceleration pulse wave based on pulse wave data, and to calculate a ratio between a low frequency component and a high frequency component included in the acceleration pulse wave of a predetermined period as the index. Item 3. The optical measurement device according to Item 2.   The pulse wave measuring means transmits measurement light having the same wavelength as the measurement light from the brain measurement light transmission terminal constituting the head measurement channel from the brain measurement light transmission terminal constituting the pulse wave measurement channel. The optical measurement device according to claim 1, wherein the optical measurement device is configured to irradiate.   The optical measurement device according to claim 1, wherein the brain activity measurement unit and the pulse wave measurement unit are configured to acquire measurement data at the same sampling interval.   The pulse wave measuring means has the same timing as the measurement light from the brain measurement light transmission terminal constituting the head measurement channel and the brain measurement light transmission terminal constituting the pulse wave measurement channel. The optical measurement device according to claim 1, wherein the optical measurement device is configured to irradiate measurement light. A plurality of the head measurement channels are configured,
The optical measurement device according to claim 1, wherein the number of the pulse wave measurement channels is one by a pair of the light transmission terminals for brain measurement and the light reception terminals for brain measurement. A head measurement holder for holding the brain measurement light transmitting terminal and the brain measurement light receiving terminal at a head measurement position corresponding to the head region of interest;
A pulse wave measurement holder that holds the light transmission terminal for brain measurement and the light reception terminal for brain measurement at a pulse wave measurement position of a subject;
The brain measurement light transmitting terminal and the brain measurement light receiving terminal are configured to be detachable from the head measurement holder and the pulse wave measurement holder, respectively. The optical measuring device according to item.

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