JP2015100410A - Brain function measurement instrument and brain function measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brain function measurement instrument and a brain function measurement method which implement efficient brain function measurement with fewer detection means such as probes to reduce burden on a subject.SOLUTION: A brain function measurement instrument 1 comprises: a detection unit 3 including a plurality of probes which have a selectively operable light projection part and light detection part formed integrally and which are regularly arranged in a subject's head; a control unit 10 for selectively operating the light projection part and the light detection part in each of the probes such that the light detection part only detects the light projected by the light projection part in one of the adjacent probes at any time point; and a data measurement unit 11 for measuring the intensity of the light detected by the light detection part. A brain function measurement method using the brain function measurement instrument 1 or the like is also provided.

Description

The present invention relates to a brain function measuring device and a brain function measuring method used in fields such as biomedical engineering.

  Various devices and methods have been devised so far to obtain information indicating functions inside the living body. For example, Patent Literature 1 discloses an optical measurement device using the optical fiber bundle 14 shown in FIG. And an optical measurement method are disclosed.

JP 2007-111461 A

  A probe is used for measuring the brain function. Usually, as shown in FIG. 7, a space in which a light irradiation probe PE dedicated to a light source and a light detection probe PD dedicated to detection repeat at 30 mm intervals. Optical measurement has been performed at a large number of measurement points (hereinafter also referred to as “channels”) M, which are arranged on the head in a pattern and are located at intermediate points between adjacent light irradiation probes PE and light detection probes PD.

  However, when the light irradiation probe PE and the light detection probe PD are arranged in this way, data can be measured (sampling) only at a spatial density of 30 mm square intervals from the measurement point M, so that activation of the brain function is temporarily measured. When it occurs at a position between M, a detection omission is caused.

  In order to avoid such inconvenience, as shown in FIG. 8, the light irradiation probe PE and the light detection probe PD are spaced at intervals of about 15 mm, which is the theoretical spatial resolution of brain function activation detection by near infrared spectroscopy. In this method, the number of the light irradiation probes PE and the light detection probes PD required for measuring the same area is the same as the arrangement method shown in FIG. Since it is twice as much, it takes time and effort to attach to the subject, and the subject is subject to a heavy load due to the light irradiation probe PE and the light detection probe PD, and the wire connecting these to the measurement terminal. There is.

  The present invention has been made in order to solve the above-described problems, and realizes an efficient measurement of brain function by a detecting means such as a smaller number of probes, and an apparatus for reducing the load on the subject. It aims to provide a method.

  In order to solve the above-described problems, the present invention includes a plurality of detection means having a light irradiation unit and a light detection unit that are integrally formed, and wherein the light irradiation unit and the light detection unit are selectively operated. All the light detection units that are regularly arranged on the head of the subject and detect light emitted from the light irradiation unit at any time are included in one adjacent detection means. A brain that selectively operates the light irradiating unit and the light detecting unit included in each detection means so as to detect only the light emitted from the unit, and measures the intensity of the light detected by the light detecting unit A function measuring means is provided.

  According to the present invention, it is possible to provide a brain function measuring device and a brain function measuring method capable of realizing efficient brain function measurement with a smaller number of detection means such as probes and reducing the load on the subject.

It is a block diagram which shows the structure of the brain function measuring apparatus 1 which concerns on embodiment of this invention. It is a figure which shows the structure of the bifurcated probe TP contained in the detection part 3 shown by FIG. It is a figure which shows the control method of the light irradiation probe PE and light detection probe PD by the control part 10 shown by FIG. It is a figure for demonstrating the brain function measuring method at the time of arrange | positioning the bifurcated probe TP by the hexagonal close-packing of 30 mm space | interval. It is a figure which shows the measuring method in the case where the conventional light irradiation probe and light detection probe are arrange | positioned at simple square lattice shape. It is a figure which shows the measuring method in case the conventional light irradiation probe and light detection probe are arrange | positioned at a double-density square lattice form. It is a figure for demonstrating the brain function measuring method when the light irradiation probe PE and the light detection probe PD are arrange | positioned at a simple square lattice form. It is a figure for demonstrating the brain function measuring method in case the light irradiation probe PE and the light detection probe PD are arrange | positioned at a double-density square-grid form.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or equivalent parts.

  FIG. 1 is a block diagram showing a configuration of a brain function measuring apparatus 1 according to an embodiment of the present invention. As shown in FIG. 1, the brain function measurement apparatus 1 includes a measurement terminal 2 and a detection unit 3, and the measurement terminal 2 includes a control unit 10, a data measurement unit 11, a storage unit 12, an operation unit 13, a display unit 14, And the light source unit 15. The detection unit 3 and the light source unit 15 are connected by a light irradiation wire 5, and the detection unit 3 and the data measurement unit 11 are connected by a data wire 7. The light irradiation wire 5 and the data wire 7 correspond to a plurality of two-branch probes TP arranged in the detection unit 3 as described later.

  Here, the control unit 10 is connected to the data measurement unit 11, the storage unit 12, the operation unit 13, the display unit 14, and the light source unit 15, and the storage unit 12 is connected to the data measurement unit 11 and the display unit 14. The display unit 14 is also connected to the operation unit 13.

  On the other hand, the detection unit 3 includes a plurality of bifurcated probes TP shown in FIG. As shown in FIG. 2, the bifurcated probe TP forms an integral wire with the light irradiation probe PE and the light detection probe PD, and at the tip portion applied to the head of the subject, the light irradiation probe PE. And the photodetection probe PD are bifurcated. The other end of the light irradiation probe PE is connected to the light source unit 15 through the light irradiation wire 5, and the other end of the light detection probe PD is connected to the data measurement unit 11 through the data wire 7.

  Then, in the pair of the two-branch probes TP, light including near infrared rays is irradiated from the tip of the light irradiation probe PE included in one of the two-branch probes TP to the head of the subject, and the other two-branch probe Measurement of brain function using functional near-infrared spectroscopy (fNIRS) is realized by detecting the light from the head at the tip of the light detection probe PD included in the TP. The

  In the brain function measuring apparatus 1 having the above-described configuration, the control unit 10 selectively irradiates light to a plurality of light irradiation probes PE in order to execute an operation selected by the operation of the operation unit 13 by the user. The data measuring unit 11 is controlled so as to switch the light source unit 15 so as to selectively measure the intensity of light received by the plurality of light detection probes PD. The selective control of the light irradiation probe PE and the light detection probe PD by the control unit 10 will be described in detail later.

Further, the control unit 10 stores the intensity of the light measured by the data measurement unit 11 in the storage unit 12 according to the operation of the operation unit 13 by the user, and the intensity of the light stored in the storage unit 12 or the like. Data is displayed on the display unit 14. The control unit 10 can control the display of the display unit 14 in accordance with the above operation, and the operation unit 13 can adjust the display function of the display unit 14 in accordance with the above operation.

  Hereinafter, the selective control of the light irradiation probe PE and the light detection probe PD by the control unit 10 will be described in detail with reference to FIG.

  As shown in FIG. 3 (a), the plurality of bifurcated probes TP are arranged in a hexagonal close-packed arrangement in the detection unit 3, and each midpoint of adjacent bifurcated probes TP is the subject's brain. A measurement point M for measuring the function is used.

  Here, assuming that the midpoint of the adjacent bifurcated probe TP is the measurement point M as described above, if this probe is arranged in a simple square lattice pattern at intervals of 30 mm as shown in FIG. The distance between the points M is about 21 mm. On the other hand, when the bifurcated probe TP is disposed by hexagonal close-packing at intervals of 30 mm as shown in FIG. 4, the distance between the measurement points M can be shortened to 15 mm.

  The control unit 10 selectively operates the light irradiation probe PE and the light detection probe PD in each bifurcated probe TP arranged in a hexagonal close-packed manner in this way.

  That is, in the two-branch probe TP that emits light from the light irradiation probe PE, the control unit 10 does not simultaneously detect light by the light detection probe PD that is paired with the light irradiation probe PE. All the light detection probes PD that control the TP and detect the light irradiated from the light irradiation probe PE at any time are irradiated from the light irradiation probe PE included in one adjacent bifurcated probe TP. The light irradiation probe PE and the light detection probe PD included in each bifurcated probe TP are selectively operated so as to detect only the emitted light.

  In the following, an example of the above control by the control unit 10 for the six bifurcated probes TP shown in FIG. Note that this control prevents the data measured at each measurement point M from interfering with the data measurement unit 11 by changing the intensity of light detected by the light detection probe PD at different times for each measurement point M. Time division multiple access (TDMA) is used.

  At time T, as shown in FIG. 3B, the control unit 10 selectively operates the light detection probe PD with the two-branch probes TP2 to TP5 indicated by black circles to detect light. In the bifurcated probes TP1 and TP6 indicated by, the light irradiation probe PE is selectively operated to irradiate light.

  As a result, the bifurcated probes TP2 and TP3 detect the light emitted from the bifurcated probe TP1, thereby intermediate the bifurcated probe TP1 and the bifurcated probe TP2 and the bifurcated probe TP1 and bifurcated. The function of the subject's brain at two measurement points M located in the middle of the probe TP3 is measured. Similarly, the bifurcated probes TP4 and TP5 detect the light emitted from the bifurcated probe TP6, so that they are intermediate between the bifurcated probe TP6 and the bifurcated probe TP4 and the bifurcated probes TP6 and TP5. The function of the subject's brain at two measurement points M located in the middle of the branching probe TP5 is measured. Note that the light emitted from the bifurcated probe TP1 is not detected in the bifurcated probe TP4 and the bifurcated probe TP5 because they are far from the bifurcated probe TP1. Similarly, in the two-branch probe TP2 and the two-branch probe TP3, the light emitted from the two-branch probe TP6 is not detected.

  Next, at time 2T after the lapse of time T, as shown in FIG. 3C, the control unit 10 selectively operates the light detection probe PD with the bifurcated probes TP1, TP3, and TP4. In the two-branch probe TP2, the light irradiation probe PE is selectively operated to emit light.

  As a result, the bifurcated probes TP1, TP3, TP4 detect the light emitted from the bifurcated probe TP2, thereby providing an intermediate between the bifurcated probe TP2 and the bifurcated probe TP1, The function of the subject's brain is measured at three measurement points M located in the middle of the bifurcated probe TP3 and in the middle of the bifurcated probe TP2 and the bifurcated probe TP4.

  Next, at time 3T after the elapse of time T, as shown in FIG. 3D, the control unit 10 selectively selects the light detection probe PD with the bifurcated probes TP1, TP2, TP4, and TP5. The two-branch probe TP3 selectively operates the light irradiation probe PE to irradiate light.

  As a result, the bifurcated probes TP1, TP2, TP4, and TP5 detect the light emitted from the bifurcated probe TP3, so that they are intermediate between the bifurcated probe TP3 and the bifurcated probe TP1. At four measurement points M located between TP3 and the bifurcated probe TP2, between the bifurcated probe TP3 and the bifurcated probe TP4, and between the bifurcated probe TP3 and the bifurcated probe TP5 Measure the function of the subject's brain.

  Next, at time 4T after the elapse of time T, as shown in FIG. 3E, the control unit 10 selectively selects the light detection probe PD with the bifurcated probes TP2, TP3, TP5, and TP6. The two-branch probe TP4 selectively operates the light irradiation probe PE to irradiate light.

  As a result, the bifurcated probes TP2, TP3, TP5, and TP6 detect the light emitted from the bifurcated probe TP4, so that they are intermediate between the bifurcated probe TP4 and the bifurcated probe TP2, and the bifurcated probe TP2. At four measurement points M located in the middle of TP4 and the bifurcated probe TP3, in the middle of the bifurcated probe TP4 and the bifurcated probe TP5, and in the middle of the bifurcated probe TP4 and the bifurcated probe TP6 Measure the function of the subject's brain.

  Next, at time 5T after the elapse of time T, as shown in FIG. 3 (f), the control unit 10 selectively operates the light detection probe PD with the bifurcated probes TP3, TP4, and TP6. The two-branch probe TP5 selectively activates the light irradiation probe PE to emit light.

  Thus, the bifurcated probes TP3, TP4, and TP6 detect the light emitted from the bifurcated probe TP5, so that the intermediate between the bifurcated probe TP5 and the bifurcated probe TP3, the bifurcated probe TP5, The function of the subject's brain is measured at three measurement points M located in the middle of the bifurcated probe TP4 and in the middle of the bifurcated probe TP5 and the bifurcated probe TP6.

  The control of the bifurcated probe TP by the controller 10 shown in FIGS. 3B to 3F can be summarized as shown in FIG. Here, the numbers in the figure indicate the order of the measurement points M measured from time T to time 5T at the positions of the measurement points M.

  According to FIG. 3 (g), it can be seen that at each measurement point M located in the middle of the adjacent bifurcated probe TP, the light intensity is measured twice until the time 5T.

  Here, for comparison with the control method shown in FIG. 3, a measurement method in the case where the conventional light irradiation probe and the light detection probe are arranged in a simple square lattice will be described with reference to FIG.

  FIG. 5 (a) shows an example of a conventional light irradiation probe and light detection probe arranged in a simple square lattice shape. Light irradiation probes PE1, PE2, PE3 and black circles indicated by white circles are shown. The photodetection probes PD1, PD2, PD3 indicated by are alternately arranged in a simple square lattice pattern.

  At time T, as shown in FIG. 5 (b), the light detection probes PD1 and PD2 detect the light emitted from the light irradiation probe PE1 to thereby detect the light irradiation probe PE1 and the light detection probe PD1. The function of the brain of the subject is measured at two measurement points M located between the light irradiation probe PE1 and the light detection probe PD2.

  Next, at time 2T after the elapse of time T, as shown in FIG. 5C, the light detection probes PD1, PD2, and PD3 detect light emitted from the light irradiation probe PE2, thereby irradiating light. The brain of the subject at three measurement points M located between the probe PE2 and the light detection probe PD1, between the light irradiation probe PE2 and the light detection probe PD2, and between the light irradiation probe PE2 and the light detection probe PD3. Measure function.

  Further, at time 3T after the elapse of time T, as shown in FIG. 5D, the light detection probes PD2 and PD3 detect the light irradiated from the light irradiation probe PE3 to thereby detect the light irradiation probe PE3. The function of the subject's brain is measured at two measurement points M located between the light detection probe PD2 and between the light irradiation probe PE3 and the light detection probe PD3.

  The control methods shown in FIGS. 5B to 5D can be summarized as shown in FIG. 5E. Here, the numbers in the figure indicate the order of the measurement points M measured from time T to time 3T at the positions of the measurement points M.

  According to FIG. 5 (e), it can be seen that at each measurement point M located in the middle of adjacent probes, the light intensity is measured once until the time 3T.

  Similarly, a measurement method in the case where conventional light irradiation probes and light detection probes are arranged in a double-density square lattice will be described with reference to FIG.

  FIG. 6A shows an example of a conventional light irradiation probe and light detection probe arranged in a double-density square lattice, and light irradiation probes PE1, DPE1, PE2, indicated by white circles. The light detection probes PD1, DPD1, PD2, DPD2, and PD3 indicated by black circles DPE2 and PE3 are alternately arranged in a double-density square lattice pattern.

  At time T, as shown in FIG. 6 (b), the light detection probes PD1 and PD2 detect the light emitted from the light irradiation probe PE1, so that the light irradiation probe PE1 and the light detection probe PD1 The function of the brain of the subject is measured at two measurement points M located between the light irradiation probe PE1 and the light detection probe PD2.

  Next, at the time 2T after the elapse of the time T, as shown in FIG. 6C, the light detection probes PD1, PD2, and PD3 detect the light emitted from the light irradiation probe PE2, thereby irradiating the light. The brain of the subject at three measurement points M located between the probe PE2 and the light detection probe PD1, between the light irradiation probe PE2 and the light detection probe PD2, and between the light irradiation probe PE2 and the light detection probe PD3. Measure function.

  Further, at time 3T after the elapse of time T, as shown in FIG. 6D, the light detection probes PD2 and PD3 detect the light emitted from the light irradiation probe PE3, so that the light irradiation probe PE3. The function of the subject's brain is measured at two measurement points M located between the light detection probe PD2 and between the light irradiation probe PE3 and the light detection probe PD3.

  Further, at time 4T after the elapse of time T, as shown in FIG. 6 (e), the light detection probes DPD1 and DPD2 detect the light irradiated from the light irradiation probe DPE1 to thereby detect the light irradiation probe DPE1 and the light. The function of the subject's brain is measured at two measurement points M located between the detection probe DPD1 and between the light irradiation probe DPE1 and the light detection probe DPD2.

  Further, at time 5T after the elapse of time T, as shown in FIG. 6 (f), the light detection probes DPD1 and DPD2 detect the light irradiated from the light irradiation probe DPE2 to thereby detect the light irradiation probe DPE2 and the light. The function of the subject's brain is measured at two measurement points M located between the detection probe DPD1 and between the light irradiation probe DPE2 and the light detection probe DPD2.

  The control methods shown in FIGS. 6B to 6F can be summarized as shown in FIG. 6G. Here, the numbers in the figure indicate the order of the measurement points M measured from time T to time 5T at the positions of the measurement points M.

  According to FIG. 6 (g), it can be seen that the intensity of light is measured once at each measurement point M, which is the middle of adjacent probes or the position of the probe, until the time 5T.

  Here, when the control method according to the embodiment of the present invention shown in FIG. 3 and the control method shown in FIGS. 5 and 6 are compared, the control method shown in FIGS. At time 3T or time 5T when the measurement cycle is completed, measurement is performed only once at each measurement point M as described above, whereas in the control method shown in FIG. Two measurements using optical paths in two forward and reverse directions are performed in the middle of the probe TP.

  From this, when the number of measurements executed per time T is compared, the control method shown in FIG. 5 is 2.3 times (= total number of measurement points 7 / hour 3T), and the control method shown in FIG. Is 2.2 times (= total number of measurement points 11 / hour 5T), but according to the control method shown in FIG. 3, it is 3.6 times (= total number of measurement points 18 / hour 5T). As compared with the control method using the conventional light irradiation probe and the light detection probe shown in FIG. 5 or FIG. 6, it is possible to realize the measurement of the brain function with higher temporal efficiency.

  Further, such time efficiency by the control method shown in FIG. 3 increases as the area to be measured increases in multi-channel measurement in which the brain function is measured at a large number of measurement points M. For example, in the case where a total of 16 conventional probes are arranged in a simple square lattice pattern at intervals of 30 mm vertically and horizontally, the area to be measured is 81 square centimeters. A total of 49 conventional probes arranged in a double-density square lattice like the arrangement shown in FIG. 8 or the closest packed lattice like the arrangement shown in FIG. When measuring with a total of 18 arranged bifurcated probes TP, the measurement target areas are 81 square centimeters and 81.8 square centimeters, respectively.

  The number of measurement points M within the measurement target area is 24 in the case of the simple square lattice arrangement, 45 in the case of the double density square lattice arrangement, and in the case of the close packed lattice arrangement. Therefore, the in-plane density at the measurement point M in the double-density square lattice arrangement and the close-packed lattice arrangement is about 2 of the in-plane density in the simple square lattice arrangement. It turns out that it becomes double.

  In addition, the time required to complete the measurement of one cycle is 4T for the simple square lattice arrangement, 8T for the double-density square lattice arrangement, and 8T for the close packed lattice arrangement. In the case of the close-packed grid arrangement, the measurement is performed twice at each measurement point M, so that the number of measurements performed per time T is 6 times / hour T, 5 6 times / hour T, 10.9 times / hour T. Therefore, according to the measurement by the close-packed grid arrangement, it is possible to realize about twice the time efficiency with respect to the measurement by the other two arrangements.

  Further, in any of the above arrangements, the measurement target area increases and the time efficiency increases, and in the case of the simple square lattice arrangement, the ratio to the case shown in FIGS. 2.6 times (= 6 times / 2.3 times), 2.5 times (= 5.6 times / 2.2 times) in the case of the above double density square lattice arrangement, In this case, it is 3.0 times (= 10.9 times / 3.6 times).

  Therefore, as shown in FIG. 3, the brain function measuring method in which the bifurcated probe TP is arranged in a close-packed grid pattern is a brain function measuring method by another arrangement when measuring a wide area. It can be seen that this is a measurement method having the property of improving the time efficiency of measurement.

  Therefore, when searching for brain function activation sites by conducting multi-channel measurement over a large area, for example, searching using large-scale near-infrared spectroscopy (NIRS) such as whole-head measurement In brain function measurement and the like, a brain function measurement method in which bifurcated probes TP are arranged in a close-packed grid as described above and each bifurcated probe TP is switched and controlled as shown in FIG. Can be said to be particularly suitable.

  As described above, according to the brain function measuring apparatus 1 and the brain function measuring method shown in FIG. 3 according to the embodiment of the present invention, the spatial sampling density is dramatically increased compared to the conventional brain function measuring method. In addition, the number of necessary probes can be greatly reduced as compared with the measurement method using the double density square lattice arrangement.

  In addition, since the number of required probes can be reduced, the time required to attach the probe to the subject's head during brain function measurement can be shortened, and the degree of adhesion between the head and each probe must be thoroughly managed. Therefore, the quality of measurement data can be improved.

  Furthermore, according to the brain function measuring apparatus 1 and the brain function measuring method shown in FIG. 3 according to the embodiment of the present invention, it occurs when the subject wears the detection unit 3 shown in FIG. 1 on the head. It is possible to reduce a load on the subject due to the probe included in the detection unit 3 or a wire connecting the probe and the measurement terminal.

DESCRIPTION OF SYMBOLS 1 Brain function measuring device 3 Detection part 10 Control part 11 Data measurement part TP Bifurcated probe PE Light irradiation probe PD Photodetection probe

Claims (6)

A plurality of detection means regularly arranged on the subject's head, including a light irradiation unit and a light detection unit that are integrally formed and selectively operate;
At any time, all the light detection units that detect the light emitted from the light irradiation unit detect only the light emitted from the light irradiation unit included in one adjacent detection unit. Control means for selectively operating the light irradiation section and the light detection section included in each of the detection means,
A brain function measuring device comprising: a measuring unit that measures the intensity of the light detected by the light detecting unit.   The brain function measuring device according to claim 1, wherein the arrangement is a close-packed grid pattern.   The brain function measuring apparatus according to claim 1, wherein the light is a near infrared ray. A plurality of detection means having a light irradiation part and a light detection part formed integrally, and a plurality of detection means for selectively operating the light irradiation part and the light detection part are regularly arranged on the head of the subject; And the steps
At any time, all the light detection units that detect the light emitted from the light irradiation unit detect only the light emitted from the light irradiation unit included in one adjacent detection unit. A brain function comprising: a second step of selectively operating the light irradiation unit and the light detection unit included in each of the detection means and measuring the intensity of the light detected by the light detection unit Measurement method.   The brain function measuring method according to claim 4, wherein the arrangement is a close-packed grid pattern. The brain function measuring method according to claim 4, wherein the light is near infrared rays.

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