JP2012254230A - Optical measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical measuring instrument for observing a blood stream change, etc., to appear in a time period before/after a task period start time.SOLUTION: The optical measuring instrument 1 includes a light transmission/reception part 30 including: N light transmission probes 12 for irradiating a subject with light; and M light reception probes 13 for receiving light coming from the subject. A storage part 23 stores a high-speed control table for acquiring measurement data concerning the brain activity of the subject by irradiating the subject with the light from the light transmission probes 12 whose number is ≥X and ≤N and a low-speed control table for acquiring measurement data concerning the brain activity of the subject by irradiating the subject with the light from the light transmission probes 12 whose number is ≥1 and ≤Y. Control parts 21, 22 perform changeover between a time period using the high-speed control table and a time period using the low-speed control table, thereby to acquire the measurement data concerning the temporal change of the brain activity of the subject.

Description

  The present invention relates to an optical measurement device, and more particularly to an optical measurement device that measures brain activity non-invasively.

In recent years, in order to observe the activity state of the brain, an optical brain functional imaging apparatus (optical measurement apparatus) that measures light simply and non-invasively has been developed. In such an optical brain functional imaging apparatus, three different types of wavelengths λ ₁ , λ ₂ , and λ ₃ (for example, 780 nm, 805 nm, and 830 nm) are close by a light transmission probe disposed on the head surface of the subject. Infrared light is irradiated onto the brain, and the intensity (received light amount information) A of the near-infrared light of each wavelength λ ₁ , λ ₂ , λ ₃ emitted from the brain by a light receiving probe arranged on the head surface. λ ₁ ), A (λ ₂ ), and A (λ ₃ ) are detected.
From the received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) thus obtained, the concentration / optical path length product [oxyHb] of oxyhemoglobin in the cerebral blood flow, and deoxy In order to obtain the hemoglobin concentration and the optical path length product [deoxyHb], for example, the simultaneous equations shown in relational expressions (1), (2), and (3) are created using the Modified Beer Lambert rule, and the simultaneous equations are solved. (For example, refer nonpatent literature 1). Furthermore, the concentration / optical path length product of total hemoglobin ([oxyHb] + [deoxyHb]) is calculated from the concentration / optical path length product [oxyHb] of oxyhemoglobin and the deoxyhemoglobin concentration / optical path length product [deoxyHb]. Yes.
A (λ ₁ ) = E _O (λ ₁ ) × [oxyHb] + E _d (λ ₁ ) × [deoxyHb] (1)
A (λ ₂ ) = E _O (λ ₂ ) × [oxyHb] + E _d (λ ₂ ) × [deoxyHb] (2)
A (λ ₃ ) = E _O (λ ₃ ) × [oxyHb] + E _d (λ ₃ ) × [deoxyHb] (3)
E _O (λm) is an absorbance coefficient of oxyhemoglobin in light having a wavelength λm, and E _d (λm) is an absorbance coefficient of deoxyhemoglobin in light having a wavelength λm.

Here, the relationship between the distance (channel) between the light transmitting probe and the light receiving probe and the measurement site will be described. FIG. 7A is a cross-sectional view showing a relationship between a pair of light transmitting probe and light receiving probe and a measurement site, and FIG. 7B is a plan view of FIG. 7A.
The light transmitting probe 12 is pressed against the light transmitting point T on the subject's head surface, and the light receiving probe 13 is pressed against the light receiving point R on the subject's head surface. Then, light is emitted from the light transmitting probe 12 and light emitted from the head surface is incident on the light receiving probe 13. At this time, the light that has passed through the banana shape (measurement region) among the light irradiated from the light transmission point T on the head surface reaches the light receiving point R on the head surface. Thereby, in the measurement region, in particular, from the midpoint Ms of the line Ls connecting the light transmitting point T and the light receiving point R at the shortest distance along the surface of the head of the subject, the light transmitting point T and the light receiving point R. Received light quantity information A (λ ₁ ), A (λ for the measurement site S of the subject who is a depth Ls / 2 that is half the distance of the line connecting the head and the head along the subject's head surface. ₂ ), A (λ ₃ ) is obtained.

In the optical brain functional imaging system, oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb] and total hemoglobin concentration / optical path length product (multiple measurement sites in the brain) In order to measure [oxyHb] + [deoxyHb]), for example, a near-infrared spectrometer is used (see, for example, Patent Document 1).
FIG. 8 is a block diagram showing an example of a schematic configuration of a conventional near-infrared spectrometer. For ease of viewing, several light transmitting optical fibers and several light receiving optical fibers are omitted.
The near-infrared spectrometer 101 has a rectangular parallelepiped casing 11.
Inside the housing 11, a light source 2 that emits light, a light source driving mechanism 4 that drives the light source 2, a light detector 3 that detects light, an A / D (A / D converter) 5, and a transmitter A light receiving control unit 121, an analysis control unit 122, and a memory (storage unit) 123 are provided, and eight light transmitting probes 12, eight light receiving probes 13, Eight light transmitting optical fibers 14, eight light receiving optical fibers 15, a display device 26 having a monitor screen 26 a and the like, and a keyboard (input device) 27 are provided.

The light source drive mechanism 4 drives the light source 2 by a drive signal input from the light transmission / reception control unit 121. The light source 2 is, for example, a semiconductor laser LD1, LD2, or LD3 that can emit near-infrared light having three different wavelengths λ ₁ , λ ₂ , and λ ₃ .
The photodetector 3 transmits and receives light reception signals (light reception amount information) A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) via A / D 5 by detecting near infrared light respectively. For example, a photomultiplier tube.

The optical fiber for light transmission 14 and the optical fiber for light reception 15 are tubular having a diameter of 2 mm and a length of 2 m to 10 m, can transmit near infrared light in the axial direction, and is incident from one end. Light passes through the inside and exits from the other end, or near-infrared light incident from the other end passes through the inside and exits from one end.
One light transmission optical fiber 14 has both end portions so that one light transmission probe 12 and one semiconductor laser LD1, LD2, LD3 of the light source 2 are separated by a set length (2 m to 10 m). Connected to.
One light receiving optical fiber 15 connects one light receiving probe 13 and one photomultiplier tube of the photodetector 3 to both ends so as to be separated by a set length (2 m to 10 m). ing.

In such a near-infrared spectrometer 101, the holder 30 is used to bring the eight light-transmitting probes 12 and the eight light-receiving probes 13 into contact with the subject's head surface in a predetermined arrangement. Is done. FIG. 2 is a plan view showing an example of a holder 30 into which eight light transmitting probes and eight light receiving probes are inserted.
The light transmitting probes 12 _{T1 to} 12 _T8 and the light receiving probes 13 _{R1 to} 13 _R8 are arranged alternately in four in the vertical direction and four in the horizontal direction. As a result, the light receiving amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) that makes the probe interval between the light transmitting probe 12 and the light receiving probe 13 constant and a specific depth from the head surface is obtained. ing. In general, a channel with a channel of 30 mm is used. When the channel is 30 mm, the received light amount information A (λ ₁ ), A (λ ₂ ) at a depth of 15 mm to 20 mm from the midpoint of the channel, It is believed that A (λ ₃ ) is obtained. That is, the position of 15 mm to 20 mm in depth from the head surface substantially corresponds to the brain surface region, and the received light quantity information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) related to the brain activity is obtained. .

By the way, in such a positional relationship between the eight light transmitting probes 12 _{T1 to} 12 _T8 and the eight light receiving probes 13 _{R1 to} 13 _R8 , a single light receiving probe 13 irradiates from a plurality of light transmitting probes 12. The timing of irradiating light from the light transmitting probe 12 and the timing of receiving light by the light receiving probe 13 so that only the light irradiated from one light transmitting probe 12 is received without simultaneously receiving the received light. Need to be adjusted. For this reason, the control table storage area 123 a of the memory 123 stores a control table indicating the timing of emitting light by the light source 2 and the timing of detecting light by the photodetector 3.
Based on the control table stored in the control table storage area 123a, the light transmission / reception control unit 121 outputs a drive signal for transmitting light to one light transmission probe 12 to the light source drive mechanism 4 at a predetermined time. At the same time, a light reception signal (light reception amount information) received by the light reception probe 13 is detected by the photodetector 3.

Here, FIG. 3 is a diagram for explaining an example of the control table. According to such a control table, first 5 milliseconds, to the light-sending probe _{12 T1} is sending a wavelength 780nm light, the next 5 milliseconds, then sending the light of wavelength 805nm to the light-sending probe _{12 T1,} One light is transmitted at a predetermined timing so that the light transmitting probe 12 _T1 transmits light having a wavelength of 830 nm for the next 5 milliseconds and the light transmitting probe 12 _T2 is transmitted light having a wavelength of 780 nm for the next 5 milliseconds. The light transmitting probes 12 _{T1 to} 12 _T8 are sequentially transmitted with light. At this time, each time light is transmitted to any one of the light transmission probes 12 _{T1 to} 12 _T8 , the light reception signals are detected by the eight light reception probes 13 _{R1 to} 13 _R8 , thereby obtaining eight light reception signals. The data is stored in the data storage area 23b of the memory 123. Then, after transmitting light to all the eight light transmitting probes 12 _{T1 to} 12 _T8 , the light receiving signals of the light receiving probes 13 _R1 and 13 _R3 that detect the light from the light transmitting probe 12 _T1 are acquired. , so as to obtain a light reception signal of the light receiving probe _{13 R1} which detects the light from the light transmitting probe _{12 T2} and the light receiving probe _{13 R2} and the light receiving probe _{13 R4,} predetermined light receiving probe ₁₃ detected at a predetermined timing R1 to 13 The light reception signal of _R8 is acquired. Thereby, when viewed in plan as shown in FIG. 2, a total of 24 (S1 to S24) received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) are collected.

Based on a total of 24 received light quantity information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ), the analysis control unit 122 uses relational expressions (1), (2), and (3), From the transmitted light intensity of each wavelength (oxyhemoglobin absorption wavelength and deoxyhemoglobin absorption wavelength), oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb] and total hemoglobin concentration The optical path length product ([oxyHb] + [deoxyHb]) is obtained as measurement data.

JP 2001-337033 A

Factors affecting the accuracy of near-infrared spectroscopy concentration calculations for focal changes in oxygenation parameters, NeuroImage 18, 865-879, 2003

  By the way, in order to diagnose whether or not a subject's living tissue is normal, a doctor, a laboratory technician or the like gives a stimulus (hereinafter referred to as “load” or “task”) to the subject, and the subject. There is a test for observing measurement data relating to temporal changes in the brain activity of the subject obtained when the examiner's brain is activated. At this time, doctors, laboratory technicians, etc., while measuring the time, first put the subject in a task-execution state that causes the finger to move for a certain period of time (for example, 20 seconds) (hereinafter referred to as “task period”). Thereafter, the subject is allowed to rest in a steady state for a certain period of time (hereinafter referred to as “rest period”). After that, the rest period and the task period are alternately repeated a plurality of times (hereinafter referred to as “the subject is in a state of performing a task of moving a finger for a certain period of time and then in a steady state for a certain period of time”). , “Task repeat count”). As a result, measurement data as shown in FIG. 9 is obtained at a certain measurement site S. Note that the oxyhemoglobin concentration / optical path length product [oxyHb] (deoxyhemoglobin concentration / optical path length product [deoxyHb] at the time when the subject wears the holder 30 is plotted on the vertical axis in the measurement data shown in FIG. 9. Concentration / optical path length product ([oxyHb] + [deoxyHb])) Oxyhemoglobin concentration / optical path length product [oxyHb] (Deoxyhemoglobin concentration / optical path length product [deoxyHb], Total hemoglobin concentration / optical path length product ( The amount of change is [oxyHb] + [deoxyHb])), and the horizontal axis is time t.

However, measurement data obtained using a control table as shown in FIG. 3 may not be able to detect changes in blood flow that appear in a time zone (for example, 4 seconds) before and after the start time of the task period. It was. That is, in the control table as shown in FIG. 3, the measurement time interval for obtaining measurement data related to the brain activity of the entire subject's brain is 125 milliseconds (number of light-transmitting probes × number of wavelengths × 5 milliseconds + DARK time). There was a problem of becoming longer.
It should be noted that if the light transmitting probes 12 that are far apart so that light hardly interferes with each other are transmitted to a plurality of light transmitting probes 12 at the same time, the efficiency of measurement can be improved. There was a problem that it was not possible to observe changes in blood flow appearing in the time zone before and after the start time.

  Therefore, in order to solve the above problems, the present inventor has studied a method for observing a blood flow change that appears in a time zone before and after the start time of the task period. Therefore, the light irradiated from the plurality of light transmitting probes 12 is simultaneously received by one light receiving probe 13 so that the measurement time interval for obtaining the measurement data related to the brain activity of the whole brain of the subject is shortened. However, the subject was irradiated with light from the eight light-transmitting probes 12 to obtain measurement data relating to the brain activity of the subject. As a result, it was found that blood flow changes appearing in the time zone before and after the start time of the task period can be observed. Therefore, by irradiating the subject with light from all eight light-transmitting probes 12, a high-speed control table for obtaining measurement data relating to the brain activity of the subject, and from one light-transmitting probe 12 It has been found that two types of control tables, a low-speed control table for obtaining measurement data relating to the brain activity of the subject, are used by sequentially irradiating a person with light. That is, the measurement data regarding the temporal change of the brain activity of the subject is obtained by switching between the time zone using the high speed control table and the time zone using the low speed control table according to the situation.

That is, the optical measuring device of the present invention includes a light transmitting / receiving unit having N light transmitting probes for irradiating light to a subject and M light receiving probes for receiving light emitted from the subject. A light measuring device comprising: a control unit that obtains measurement data related to temporal changes in the brain activity of the subject by controlling light transmission / reception with respect to the light transmission / reception unit, wherein N light transmissions A high-speed control table for obtaining measurement data related to the brain activity of the subject by irradiating the subject with light from X to N light-transmitting probes selected from the probes; For obtaining measurement data relating to the brain activity of the subject by irradiating the subject with light from one or more Y light-transmitting probes selected from among the N light-transmitting probes. A low speed control table is stored in a storage unit, and the control unit By switching and time zone time zone using the control table and using said low speed control table, the conjunction obtain measurement data with respect to time changes in brain activity of the subject, and so as to satisfy the following formula (1).
1 ≦ Y <X ≦ N (1)

Here, “measurement data on the brain activity of the subject by irradiating the subject with light from X to N light transmitting probes selected from among the N light transmitting probes. "High-speed control table for obtaining" is for observing a fast response such as a blood flow change appearing in a time zone before and after the start time of a task period with a brain in a predetermined region. In this case, the light emitted from a plurality of light-transmitting probes is received simultaneously, but it is sufficient to irradiate the subject with light from X to N light-transmitting probes. It is preferable to irradiate the subject with light from the light transmitting probe from the viewpoint of shortening the time for obtaining the measurement data.
Further, “measurement data relating to the brain activity of the subject can be obtained by irradiating the subject with light from one to Y light-transmitting probes selected from among the N light-transmitting probes. The “low-speed control table to obtain” is for observing in detail which part of the subject's brain has been activated, from one to Y light-transmitting probes in which light hardly interferes with each other. It is preferable from the viewpoint of grasping in detail which part of the subject's brain has been activated to irradiate the subject with light and to receive the light with a light receiving probe configured with a radiated light transmitting probe and a logic channel. .

  According to the optical measurement device of the present invention, according to the situation, by switching between the time zone using the high-speed control table and the time zone using the low-speed control table, to obtain measurement data regarding the temporal change in the brain activity of the subject, It is possible to observe a change in blood flow that appears in a time zone before and after the start time of the task period.

(Means and effects for solving other problems)
In the optical measurement device of the present invention, the high-speed control table obtains measurement data relating to the brain activity of the subject by irradiating the subject with light from all N light-transmitting probes. The low-speed control table may obtain measurement data related to the brain activity of the subject by sequentially irradiating the subject with light from one light transmission probe.
Furthermore, the optical measurement device of the present invention obtains the measurement data by alternately repeating a task period for continuously applying a load to the subject and a rest period for removing the load from the subject a plurality of times. In the optical measurement device, the control unit uses the high-speed control table in at least one time zone before and after the start time of the task period, and uses the low-speed control in other time zones. A table may be used.
Here, the “load” is not limited to the behavior of the subject such as finger movement. For example, the subject itself may be passive such as making the subject hear sound. Anything that expresses brain activity may be used.

The block diagram which shows schematic structure of the optical measuring device which is one Embodiment of this invention. The top view which shows an example of the holder in which eight light transmission probes and eight light reception probes are inserted. The figure for demonstrating an example of a control table (low speed control table). The top view which shows an example of the holder used in a high-speed control table. The figure for demonstrating an example of a high-speed control table. The figure which shows an example of measurement data. The figure which shows the relationship between a pair of light transmission probe and light reception probe, and the measurement site | part of a brain. The block diagram which shows an example of schematic structure of the conventional near-infrared spectrometer. The figure which shows an example of measurement data.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

FIG. 1 is a block diagram showing a schematic configuration of an optical measurement apparatus according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the thing similar to the near-infrared spectrometer 101.
The optical measuring device 1 has a rectangular parallelepiped housing 11.
Inside the housing 11, a light source 2 that emits light, a light source driving mechanism 4 that drives the light source 2, a light detector 3 that detects light, an A / D (A / D converter) 5, and a transmitter A light receiving control unit 21, an analysis control unit 22, and a memory (storage unit) 23 are provided, and eight light transmitting probes 12, eight light receiving probes 13, Eight light transmitting optical fibers 14, eight light receiving optical fibers 15, a display device 26 having a monitor screen 26 a and the like, and a keyboard (input device) 27 are provided.

In addition, the memory 23 stores a control table storage area 23a for storing a high-speed control table and a low-speed control table for determining a control mode for controlling light transmission / reception with respect to the light transmission / reception unit 11, and a light reception signal (measurement data). And a data storage area 23b for storing.
4 and 5 are diagrams for explaining an example of the high-speed control table. According to such a high-speed control table, first, light having a wavelength of 780 nm is transmitted to all eight light transmission probes 12 _{T1 to} 12 _T8 for 5 milliseconds, and then all eight light transmission probes are transmitted for the next 5 milliseconds. 12 _T1 to 12 _T8 to by sending the light of wavelength 805 nm, the next 5 milliseconds, so as to sending the light of wavelength 830nm to all eight of the light-sending probe ₁₂ T1 _{to 12 T8,} 8 at a predetermined timing Light is transmitted to all the light transmitting probes 12 _{T1 to} 12 _T8 . At this time, each time light is transmitted to the eight light transmission probes 12 _{T1 to} 12 _T8 , the light reception signals are detected by the eight light reception probes 13 _{R1 to} 13 _R8 , thereby storing the eight light reception signals in the memory 23. Are stored in the data storage area 23b. Then, the light reception signals of all eight light reception probes 13 _{R1 to} 13 _R8 are acquired. Thereby, when viewed in plan as shown in FIG. 4, a total of eight (R1 to R8) received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) are collected. In the control table as shown in FIG. 5, the measurement time interval for obtaining measurement data relating to the brain activity of the entire subject's brain is 20 milliseconds (number of wavelengths × 5 milliseconds + DARK time).

  2 and 3 are diagrams for explaining an example of the low speed control table. Note that the low speed control table is used in the same manner as the control table of the near-infrared spectrometer 101, and thus the description thereof is omitted.

  Based on the operation signal from the keyboard 27, the transmission / reception control unit 21 sets the task period time, the rest period time, and the task repetition count, so that the task period time, the rest period time, and the task are set. The number of repetitions is stored in the data storage area 23b, and the high-speed control table is used for the time zone before and after the start time of the task period (for example, 2 seconds before and after the start time of the task period). First, the light transmission / reception with respect to the holder 30 is controlled using a low speed control table. FIG. 6 is a graph showing an example of measurement data obtained at one measurement site S. The ordinate in the measurement data shown in FIG. 6 indicates the concentration of oxyhemoglobin / optical path length product [oxyHb] (deoxyhemoglobin concentration / optical path length product [deoxyHb], total hemoglobin Concentration / optical path length product ([oxyHb] + [deoxyHb])) Oxyhemoglobin concentration / optical path length product [oxyHb] (Deoxyhemoglobin concentration / optical path length product [deoxyHb], Total hemoglobin concentration / optical path length product ( The amount of change is [oxyHb] + [deoxyHb])), and the horizontal axis is time t.

In order to obtain measurement data as shown in FIG. 6, for example, before starting measurement, a doctor, a laboratory technician, or the like uses the input screen displayed on the monitor screen 23 a to set the task period time and rest period. Input and set measurement conditions such as time and number of task repetitions.
As a result, the light transmission / reception control unit 21 controls light transmission / reception with respect to the holder 30 using the low speed control table during the rest period. Therefore, first 5 milliseconds, is sending a wavelength 780nm light to the light-sending probe _{12 T1,} the next 5 milliseconds, then sending the light of wavelength 805nm to the light-sending probe _{12 T1,} the next 5 milliseconds, feed is sending the light of wavelength 830nm to the optical probe _{12 T1,} the next 5 milliseconds, the light having a wavelength of 780nm to the light-sending probe _{12 T2} so as to sending, one light transmitting probe _{12 T1} ~ at a predetermined timing 12 Lights are sent in sequence to _T8 . At this time, each time light is transmitted to any one of the light transmission probes 12 _{T1 to} 12 _T8 , the light reception signals are detected by the eight light reception probes 13 _{R1 to} 13 _R8 , thereby obtaining eight light reception signals. The data is stored in the data storage area 23b of the memory 23. Thereafter, the light is sequentially transmitted to one of the light transmission probes 12 _{T1 to} 12 _T8 at a predetermined timing until 2 seconds before the start time of the task period.

In the time zone before and after the start time of the task period, light transmission / reception with respect to the holder 30 is controlled using the high-speed control table. That is, switching from using the low speed control table to using the high speed control table 2 seconds before the start time of the task period, and switching the low speed control table from using the high speed control table 2 seconds after the start time of the task period. Switch to use. Therefore, two seconds before the start time of the task period, first, light of wavelength 780 nm is transmitted to all eight light transmission probes 12 _{T1 to} 12 _T8 for 5 milliseconds, and all eight light transmission probes are transmitted for the next 5 milliseconds. The light transmitting probes 12 _{T1 to} 12 _T8 are configured to transmit light having a wavelength of 805 nm, and for the next 5 milliseconds, all eight light transmitting probes 12 _{T1 to} 12 _T8 are configured to transmit light having a wavelength of 830 nm. Light is transmitted to all eight light transmission probes 12 _{T1 to} 12 _T8 at the timing. At this time, each time light is transmitted to the eight light transmission probes 12 _{T1 to} 12 _T8 , the light reception signals are detected by the eight light reception probes 13 _{R1 to} 13 _R8 , thereby storing the eight light reception signals in the memory 23. Are stored in the data storage area 23b. Thereafter, the light transmission to all eight light transmission probes 12 _{T1 to} 12 _T8 is repeated at a predetermined timing until 2 seconds after the start time of the task period. Then, after 2 seconds from the start time of the task period, the control table to be used is switched from the high speed control table to the low speed control table.
In this way, the control table to be used is switched from the low speed control table to the high speed control table 2 seconds before the start time of the task period, and is switched from the high speed control table to the low speed control table 2 seconds after the start time of the task period. Will be repeated until the measurement is completed.

In the time zone before and after the start time of the task period, the analysis control unit 22 uses a relational expression based on a total of eight received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ). (1) Using (2) and (3), from the intensity of light passing through each wavelength (oxyhemoglobin absorption wavelength and deoxyhemoglobin absorption wavelength), oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration The optical path length product [deoxyHb] and total hemoglobin concentration / optical path length product ([oxyHb] + [deoxyHb]) are obtained as measurement data, and in other time zones, a total of 24 received light quantity information A (λ ₁ ) Based on A (λ ₂ ) and A (λ ₃ ), the relational expressions (1), (2), and (3) are used to pass each wavelength (the absorption wavelength of oxyhemoglobin and the absorption wavelength of deoxyhemoglobin). From light intensity, oxyhemoglobin concentration and optical path Product [oxyHb], determined deoxyhemoglobin concentration-path length product [deoxyHb] and concentration-path length product of total hemoglobin ([oxyHb] + [deoxyHb]) as measurement data.
At this time, the time zone before and after the start time of the task period and the other time zones are different in the number of measurement sites of the brain from which data is acquired. For example, the measurement site S1, the measurement site S2, and the measurement site In S5, the received light amount information A (λ ₁ ), A (λ) obtained by the light receiving probe 13 _R1 in the time zone before and after the start time of the task period as the data of the time zone before and after the start time of the task period. ₂ ) and A (λ ₃ ), and in the measurement site S3 and the measurement site S7, as the data of the time zone before and after the start time of the task period, the light receiving probe 13 in the time zone before and after the start time of the task period _The received light amount obtained by the light receiving probe 13 in the time zone before and after the start time of the task period so as to use the received light amount information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) obtained by _R2. Information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) may be used for a plurality of corresponding measurement sites S.

  As described above, according to the optical measurement device 1 of the present invention, the time zone using the high-speed control table and the time zone using the low-speed control table are switched according to the situation, and the time change of the brain activity of the subject is related. Since measurement data is obtained, it is possible to observe changes in blood flow that appear in the time zone before and after the start time of the task period.

  INDUSTRIAL APPLICABILITY The present invention can be used for an optical measurement device that measures brain activity non-invasively.

1: Optical measuring device 12: Light transmission probe 13: Light reception probe 21: Light transmission / reception control unit 22: Analysis control unit 23: Memory (storage unit)
30: Holder (transmission / reception unit)
T: Transmitting point R: Receiving point

Claims (3)

A light transmission / reception unit having N light transmission probes for irradiating the subject with light and M light reception probes for receiving light emitted from the subject;
By controlling light transmission / reception with respect to the light transmission / reception unit, a light measurement device comprising a control unit for obtaining measurement data relating to temporal changes in the brain activity of the subject,
For obtaining measurement data relating to the brain activity of the subject by irradiating the subject with light from X to N light-transmitting probes selected from among the N light-transmitting probes. A high-speed control table;
For obtaining measurement data relating to the brain activity of the subject by irradiating the subject with light from one or more Y light-transmitting probes selected from among the N light-transmitting probes. The low speed control table is stored in the storage unit,
The control unit switches between a time zone using the high-speed control table and a time zone using the low-speed control table, and obtains measurement data related to temporal changes in the brain activity of the subject,
An optical measuring device satisfying the following formula (1).
1 ≦ Y <X ≦ N (1) The high-speed control table obtains measurement data related to the brain activity of the subject by irradiating the subject with light from all N light-transmitting probes,
The low-speed control table obtains measurement data related to brain activity of the subject by sequentially irradiating the subject with light from one light transmission probe. The optical measuring device according to 1. A task period for continuously applying a load to the subject and a rest period for removing the load from the subject are repeatedly repeated a plurality of times, thereby obtaining the measurement data,
The control unit uses the high-speed control table for at least one time zone before and after the start time of the task period, and uses the low-speed control table for other time zones. The optical measuring device according to claim 1 or 2.

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