Helmet, magnetoencephalography system, information acquisition device, information acquisition method, and program

Abstract

To provide a helmet in which an optical pumping magnetometer for magnetoencephalography is disposed in a fixed manner with less restraint and stress on a subject.SOLUTION: A helmet 1 of the present invention includes: a body part 11; at least two or three fixing structures 12 for fixing the body part 11 onto the head of a subject; at least one or two optical pumping magnetometers 14 for measuring magnetic force; and at least one or two holders 13 for fixing the optical pumping magnetometers 14 onto the body part 11. The body part 11 is made of a non-elastic material and is structured so that the fixing structure 12 is inserted into each of three or more holes of the body part 11. The fixing structure 12 includes an elastic body 122 made of a non-metallic material, structured so as to be fixed to the body part 11. The elastic body 122 is positioned between the head and the body part 11 so as to energize the body part 11 against the head.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a helmet or the like for obtaining a magnetoencephalogram. [Background technology]

[0002] Conventionally, there have been methods for reducing errors in magnetoencephalography caused by the presence of non-neural magnetic fields (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-545661 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the prior art, a helmet in which an optically pumped magnetometer for measuring magnetoencephalograms is fixedly positioned was not available, and there was no helmet that was less restrictive and less stressful for the subject.

[0005] Furthermore, in the prior art, a great deal of effort was required to measure the sensor position. [Means for solving the problem]

[0006] The helmet of this first invention is a helmet for magnetoencephalography measurement, and comprises a main body, two or more fixing structures for fixing the main body to the subject's head, one or more optically pumped magnetometers for measuring magnetic force, and one or more holders for fixing the optically pumped magnetometers to the main body, the main body being made of a non-elastic material and having a structure in which the fixing structures are inserted into each of three or more holes in the main body, the fixing structures being a structure that is fixed to the main body, having an elastic body made of a non-metallic material, and the elastic body being positioned between the head and the main body to bias the main body against the head.

[0007] With this configuration, it is possible to provide a helmet for measuring magnetoencephalograms that places less restraint on the subject and causes less stress.

[0008] Furthermore, the helmet of the second invention differs from the helmet of the first invention in that the fixing structure is inserted into a hole in the main body portion, the outer periphery of the hole having the shape of a female screw, the elastic body being a spring made of resin, the fixing structure having the shape of a male screw, a male screw holder that is inserted into the female screw on the outer periphery of the hole in the main body portion and fixed to the main body portion, an elastic body that is housed within the male screw holder, and a pad that is positioned between the elastic body and the head and fixes the helmet to the head.

[0009] With this configuration, it is possible to provide a helmet for measuring magnetoencephalograms that places less restraint on the subject and causes less stress.

[0010] Furthermore, in the helmet of the third invention, compared to the second invention, the fixing structure further includes a pressing portion that is pressed toward the head by a spring, and the pressing portion is disposed between the elastic body and the pad, and has the function of pressing the pad in a direction toward the head by the elastic body.

[0011] With this configuration, it is possible to provide a helmet for measuring magnetoencephalograms that places less restraint on the subject and causes less stress.

[0012] Furthermore, the helmet of the fourth invention differs from the helmet of the first invention in that it further comprises a stretchable cap that comes into contact with the subject's head.

[0013] This configuration can protect the hair on the head.

[0014] Furthermore, the magnetoencephalography measurement system of the fifth invention is a magnetoencephalography measurement system comprising a helmet having a main body, two or more fixing structures, three or more optically pumped magnetometers, and three or more holders, and a measurement device, wherein the measurement device comprises an OPM management unit that stores OPM information for each of the three or more optically pumped magnetometers, the OPM information having an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point on the subject's head, and an OPM direction that specifies the direction of the optically pumped magnetometer, and a magnetic force storage unit that acquires the magnetic force measured by the optically pumped magnetometer for each of the three or more optically pumped magnetometers and stores the magnetic force in correspondence with the OPM information.

[0015] With this configuration, it is possible to provide a magnetoencephalogram measurement system including a helmet on which an optically pumped magnetometer for measuring magnetoencephalograms is fixedly disposed.

[0016] The sixth invention also provides an information acquisition device for acquiring OPM information in a measurement device comprising: an OPM management unit for storing, for each of three or more optical pumping magnetometers, OPM information having an OPM position that specifies the relative position of the optical pumping magnetometer with respect to a head reference point that is a reference point on the head of a subject, and an OPM direction that specifies the direction of the optical pumping magnetometer; and a magnetic force storage unit for acquiring, for each of the three or more optical pumping magnetometers, the magnetic force measured by the optical pumping magnetometer, and storing the magnetic force in association with the OPM information, the information acquisition device comprising: a main unit; the helmet includes three or more fixing structures for fixing the helmet to the head of a subject, three or more optical pumping magnetometers, and a holder for holding each of the three or more optical pumping magnetometers; an initial management unit in which first information is stored for each of the three or more optical pumping magnetometers, the first information having a first position specifying the position of each of the three or more optical pumping magnetometers with respect to a helmet reference point that is a reference point of the helmet, and an OPM direction specifying the direction of each of the three or more optical pumping magnetometers, and in which a first singular point position specifying the position of a singular point corresponding to each of the three or more landmarks on the helmet is stored; a brain image acquisition unit that acquires brain images of the inside of the head of the subject; an OPM information acquisition unit that acquires, for each of the three or more optically pumped magnetometers, OPM information having an OPM position that specifies a relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject and an OPM direction of the optically pumped magnetometer, using the first information, the first singular point position, the three-dimensional image, and the brain image; and a storage unit that stores the OPM information acquired by the OPM information acquisition unit for each of the three or more optically pumped magnetometers, the acquisition unit includes a first conversion means for acquiring second singularity positions that identify the positions of singularities corresponding to each of the three or more landmarks in the three-dimensional image, and converting a first position of each of the three or more optically pumped magnetometers into a second position that identifies the position in the three-dimensional image using each of the three or more second singularity positions and each of the three or more first singularity positions; acquiring a first subject position that identifies the position of a first subject reference point that is a reference point of the subject in the three-dimensional image, and acquiring a second subject position that identifies the position of a second subject reference point that is a reference point of the subject in the brain image, and using the first subject position and the second subject position;The information acquisition device includes a second conversion means for converting a second position in a three-dimensional image and acquiring an OPM position that identifies a relative position with respect to a head reference point in a brain image, and an OPM information acquisition means for acquiring OPM information having the OPM position and OPM direction acquired by the second conversion means for each of three or more optically pumped magnetometers.

[0017] With this configuration, the position of the optically pumped magnetometer can be measured quickly and easily.

[0018] In addition, the information acquisition device of the seventh invention, compared to the sixth invention, further comprises a holder management unit in which holder information is stored for each of three or more optical pumping magnetometers, the holder information having a holder position that identifies the position of each of three or more singular points of a holder that can hold the optical pumping magnetometer, and an OPM direction that identifies the orientation of the optical pumping magnetometer when held in the holder; a sensor coordinate management unit in which a relative sensor position that is information that identifies the sensor position, which is the measurement point of the magnetic force of the optical pumping magnetometer, and is information that identifies the relative position with respect to the holder; and an initial information acquisition unit that uses the holder position and the relative sensor position to acquire a first position for each of the three or more optical pumping magnetometers, and acquires first information that has the first position and the OPM direction, and the first information of the initial management unit is the first information acquired by the initial information acquisition unit.

[0019] With this configuration, the position of the optically pumped magnetometer can be measured very quickly and easily. [Effects of the Invention]

[0020] The helmet according to the present invention is a helmet in which an optically pumped magnetometer for measuring magnetoencephalograms is fixedly disposed, and it is possible to provide a helmet that places less restraint on the subject and causes less stress. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a conceptual diagram of a magnetoencephalography measurement system A according to the first embodiment. [Figure 2]Block diagram of the magnetoencephalography measurement system A [Figure 3] Block diagram of the information acquisition device 3 [Figure 4] FIG. 1 shows an example of the appearance of the holder 13. [Figure 5] A diagram showing an example of the appearance of the cap 15 [Figure 6] Enlarged view of the female screw 1101 [Figure 7] FIG. 10 shows the male screw holder 121 being inserted into the female screw 1101. [Figure 8] FIG. 12 shows an example of the fixing structure 12. [Figure 9] A diagram showing an example of the holder 13 [Figure 10] A diagram showing an example of the cap 15 [Figure 11] A diagram showing an example of the holder 13 [Figure 12] FIG. 1 shows an example of the OPM sensor 14. [Figure 13] A flowchart illustrating an example of the operation of the information acquisition device 3 [Figure 14] Overview of the computer system [Figure 15] Block diagram of the computer system DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of a helmet and the like will be described with reference to the drawings. Note that components with the same reference numerals in the embodiments perform similar operations, and therefore repeated description may be omitted.

[0023] (Embodiment 1) 1 is a conceptual diagram of a magnetoencephalogram measurement system A according to the present embodiment. The magnetoencephalogram measurement system A includes a helmet 1, a measurement device 2, and an information acquisition device 3.

[0024] The helmet 1 is for magnetoencephalography measurement and is placed on the head of the subject.

[0025] The measuring device 2 is a device that acquires the magnetic force acquired by an optical pumping magnetometer 14 (hereinafter referred to as "OPM sensor 14" as appropriate) described below, and stores the magnetic force in association with information that identifies the position and direction of the OPM sensor 14.

[0026] The information acquisition device 3 is a device that acquires information that specifies the position and orientation of the OPM sensor 14 relative to a reference point on the subject's head. The measurement device 2 and the information acquisition device 3 may be so-called servers or terminals. The server may be, for example, a cloud server or an ASP server, but the type does not matter. The terminal may be, for example, a PC or tablet terminal, but the type does not matter.

[0027] In this specification, information X being associated with information Y means that information Y can be obtained from information X, or information X can be obtained from information Y, and the method of association is not important. Information X and information Y may be linked, may exist in the same buffer, information X may be included in information Y, or information Y may be included in information X, etc.

[0028] Furthermore, in this specification, selecting or determining information Z means obtaining information Z, obtaining a pointer to information Z, obtaining the ID of information Z, setting a flag on information Z, etc., and it is sufficient if information Z can be accessed.

[0029] 2 is a block diagram of the magnetoencephalography measurement system A according to this embodiment, and FIG.

[0030] The helmet 1 constituting the magnetoencephalography measurement system A includes a main body 11, a fixing structure 12, a holder 13, an optically pumped magnetometer 14, and a cap 15. The fixing structure 12 includes, for example, a male screw holder 121, an elastic body 122, a pressing portion 123, and a pad 124.

[0031] The measurement device 2 includes an OPM management unit 21, a processing unit 22, and an output unit 23. The processing unit 22 includes a magnetic force accumulation unit 221.

[0032] The information acquisition device 3 includes a storage unit 31 and a processing unit 32. The storage unit 31 includes a holder management unit 311, a sensor coordinate management unit 312, and an initial management unit 313. The processing unit 32 includes an initial information acquisition unit 320, a three-dimensional image acquisition unit 321, a brain image acquisition unit 322, an OPM information acquisition unit 323, and an accumulation unit 324. The OPM information acquisition unit 323 includes a first conversion means 3231, a second conversion means 3232, and an OPM information acquisition means 3233.

[0033] It is preferable that the main body 11 constituting the helmet 1 has a space into which the fixing structure 12 is inserted. It is also preferable that the main body 11 has a space into which the OPM sensor 14 is inserted. The space may be called a hole. The main body 11 has a structure in which the fixing structure 12 is inserted into each of three or more holes in the main body 11.

[0034] The main body 11 is made of a non-metallic material. It is preferable that the main body 11 is made of resin, but it may also be made of ceramics or the like. It is preferable that the main body 11 is made of a non-elastic material.

[0035] The fixing structure 12 is a structure for fixing the main body 11 to the head of the subject. Fixing the main body 11 to the head of the subject may be done by fixing the main body 11 to the head of the subject via a cap 15.

[0036] In order to sufficiently fix the main body 11 to the head of the subject using the fixing structures 12, it is preferable that there are three or more spaces into which the fixing structures 12 are inserted. It is preferable that the spaces into which the fixing structures 12 are inserted are located in front, on the left side, and on the right side of the head of the subject.

[0037] In order to obtain an appropriate magnetoencephalogram, it is preferable that the number of spaces into which the OPM sensors 14 are inserted is three or more.

[0038] The fixing structure 12 has an elastic body 122 that is positioned between the subject's head and the main body 11, thereby biasing the main body 11 toward the head. As shown in Fig. 4, the fixing structure 12 includes, for example, a male screw holder 121, an elastic body 122, a pressing portion 123, and a pad 124.

[0039] The male screw holder 121 has a male screw shape and is inserted into the female screw on the outer periphery of the hole in the main body 11, and has the function of fixing the fixing structure 12 to the main body 11. The male screw holder 121 has one or more notches 1211. As shown in FIG. 4, the male screw holder 121 preferably has four notches 1211.

[0040] The elastic body 122 is inserted into the male screw holder 121. The elastic body 122 is fixed to the main body 11 by being inserted into the male screw holder 121. It is preferable that the elastic body 122 is a spring. However, the elastic body 122 may be made of rubber, urethane, or the like. The elastic body 122 is made of a non-metallic material. This is because magnetism cannot be measured if a metallic elastic body 122 is used. It is preferable that the non-metallic material is resin, but rubber, wood, ceramics, or the like may also be used.

[0041] The pressing portion 123 is a portion that is pressed toward the head by the elastic body 122. The pressing portion 123 is disposed between the elastic body 122 and the pad 124, and has the function of pressing the pad 124 in the direction toward the head by the elastic body 122.

[0042] It is preferable that the fixing structure 12 has the pressing portion 123, but it is not necessary that the fixing structure 12 has the pressing portion 123.

[0043] The pad 124 comes into contact with the subject's head or the cap 15. In order to reduce irritation to the head when the main body 11 is fixed to the head, the pad 124 is preferably made of a flexible material. The pad 124 is preferably made of rubber, but may also be made of silicone, polyurethane foam, leather, etc.

[0044] The pad 124 is disposed between the elastic body 122 and the head. The pad 124 has the function of fixing the helmet 1 to the head.

[0045] For example, the outer periphery of the hole in the main body 11 has a structure of a female screw 1101. Then, when the male screw holder 121 of the fixing structure 12 rotates and the outer periphery of the hole in the main body 11 is inserted into the female screw 1101, the fixing structure 12 performs the function of fixing the main body 11 to the head of the subject. Note that FIG. 6 is an enlarged view of the female screw 1101 present around the hole in the main body 11. Also, FIG. 7 is a view showing the male screw holder 121 of the fixing structure 12 inserted into the female screw 1101 of the main body 11.

[0046] The fixing structure 12 may have the structure shown in Fig. 8. Such fixing structure 12 has a female screw 125, an elastic body 122, a male screw 121, and a pad 124. The fixing structure 12 of Fig. 8 has a pad 124 that contacts the subject's head or the cap by means of the elastic body 122 (a spring in this case), a male screw 121 that contacts the pad 124, a spring 122 that is inserted into the male screw 121 and the female screw 125 and urges the pad 124 toward the head when the screw is tightened, and the female screw 125. As shown in Fig. 6, the fixing structure 12 has the pad 124, male screw 121, spring 122, and female screw 125 arranged in this order from the side closest to the subject's head.

[0047] In other words, the fixing structure 12 may be any structure that has the function of fixing the main body 11 and the subject's head.

[0048] Holder 13 is a structure for fixing OPM sensor 14 to main body 11. As shown in FIG. 9 , holder 13 is, for example, integrated with main body 11 and has three or four protrusions. Holder 13 has, for example, three or more protrusions surrounding a hole in main body 11. The three or four protrusions fix OPM sensor 14. Holder 13 is not limited to the structure shown in FIG. 9 as long as it can fix OPM sensor 14 to main body 11. While it is preferable that holder 13 be integrated with main body 11, it may also be separable from main body 11. However, when holder 13 fixes OPM sensor 14 to main body 11, holder 13 is fixed to main body 11.

[0049] The optically pumped magnetometer 14 is a device that measures a magnetic field. The optically pumped magnetometer 14 is, for example, the "QuSpin Zero-Field Magnetometer" (see URL "https: / / nanoxeed.co.jp / product / qzfm_gen2 / "). The optically pumped magnetometer 14 is a known technique, so a detailed description thereof will be omitted.

[0050] The cap 15 is used to protect the subject's head when measuring the magnetic force of the subject's head. The cap 15 is usually in contact with the subject's head. The cap 15 is preferably made of a stretchable material. The cap 15 is made of, for example, a stretchable fiber. FIG. 10 is a diagram showing an example of the cap 15.

[0051] The OPM management unit 21 constituting the measurement device 2 stores three or more pieces of OPM information. The OPM information has an OPM position and an OPM direction. The OPM position is information specifying the position at which magnetic force is measured. The OPM position is information specifying the relative position of the OPM sensor 14 with respect to a reference point on the subject's head. The OPM position is information specifying the position of the center of the sensor that measures magnetic force. The OPM position is a three-dimensional coordinate value (x, y, z). The OPM direction is information specifying the direction of the OPM sensor 14 when held in the holder 13. The OPM direction is a vector. Each of the three or more pieces of OPM information corresponds to a different OPM sensor 14. Each of the three or more pieces of OPM information corresponds to, for example, a sensor identifier. The sensor identifier is information that identifies the OPM sensor 14. The sensor identifier may be a holder identifier that identifies the holder 13.

[0052] The processing unit 22 performs various types of processing. The various types of processing are, for example, processing performed by the magnetic force storage unit 221.

[0053] The magnetic force accumulation unit 221 acquires the magnetic force measured by the optical pumping magnetometer 14 for each of the three or more optical pumping magnetometers, and accumulates the magnetic force in association with the OPM information. The magnetic force accumulation unit 221 accumulates the magnetic force in association with the OPM information, for example, in the OPM management unit 21 of the measurement device 2 or in a device not shown.

[0054] The output unit 23 outputs the magnetic force stored in the magnetic force storage unit 221 for each of the three or more optically pumped magnetometers.

[0055] Here, output is a concept that includes displaying on a display, projection using a projector, printing on a printer, sound output, transmission to an external device, storage on a recording medium, and delivery of processing results to other processing devices or other programs.

[0056] Various types of information are stored in the storage unit 31 constituting the information acquisition device 3. The various types of information include, for example, holder information (to be described later), relative sensor positions (to be described later), first information (to be described later), and various mathematical formulas (to be described later).

[0057] The holder management unit 311 stores holder information for each of the three or more OPM sensors 14. The holder information is information relating to the holder 13. The holder information includes the holder position and the OPM direction.

[0058] The holder position is information that specifies the position of each of three or more singular points of the holder 13. FIG. 11 shows an example of the holder 13. Here, the holder 13 has four singular points (1101, 1102, 1103, 1104). The holder position is usually a three-dimensional coordinate value.

[0059] The sensor coordinate management unit 312 stores the relative sensor position. The relative sensor position is information that specifies the sensor position, which is the measurement point of the magnetic force of the OPM sensor 14. The relative sensor position is information that specifies the relative position of the sensor position with respect to the holder 13. The relative sensor position is information that specifies the relative position of the sensor position with respect to the holder position. The relative sensor position is usually a three-dimensional coordinate value.

[0060] The initial management unit 313 stores first information for each of the three or more OPM sensors 14. Three or more first singularity positions are stored in the initial management unit 313. It is preferable that the initial management unit 313 stores about six first singularity positions.

[0061] The first information includes a first position and an OPM direction. The first position is information that specifies the relative position of the OPM sensor 14 with respect to a helmet reference point. The helmet reference point is a reference point of the helmet 1. The helmet reference point is typically a three-dimensional coordinate value, for example, (0,0,0).

[0062] The first singular point position is information that specifies the position of a singular point corresponding to each of three or more landmarks on the helmet 1. The first singular point position is information that specifies the relative position of the landmark with respect to the helmet reference point. The first singular point position is usually a three-dimensional coordinate value. It is preferable that the helmet 1 have around six landmarks.

[0063] The processing unit 32 performs various types of processing. The various types of processing are, for example, processing performed by an initial information acquisition unit 320, a three-dimensional image acquisition unit 321, a brain image acquisition unit 322, an OPM information acquisition unit 323, and a storage unit 324.

[0064] The initial information acquisition unit 320 acquires a first position for each of the three or more OPM sensors 14 using the holder position and the relative sensor position. The initial information acquisition unit 320 acquires first information having the first position and the OPM direction. This first information is the first information of the holder management unit 311.

[0065] Here, it is assumed that holder 13 has the shape shown in FIG. 11. Here, holder 13 has four protrusions extending in the direction. The coordinate value of the singular point corresponding to 1101 on holder 13 is (1), the coordinate value of the singular point corresponding to 1102 is (2), the coordinate value of the singular point corresponding to 1103 is (3), and the coordinate value of the singular point corresponding to 1104 is (4). Also, it is assumed that OPM sensor 14 has the shape shown in FIG. 12, for example.

[0066] In this case, the initial information acquisition unit 320 acquires the OPM direction using Equation 1. The initial information acquisition unit 320 also acquires the holder position using Equation 2. Note that (a, b, c) in Equation 2 are constants.

[0067]

number

[0068]

number

[0069] The three-dimensional image acquisition unit 321 acquires a three-dimensional image of the head of the subject wearing the helmet 1. The three-dimensional image acquisition unit 321 is, for example, a camera that can capture three-dimensional images. The three-dimensional image acquisition unit 321 may acquire the three-dimensional image from the storage unit 31 or an external device (not shown).

[0070] The brain image acquisition unit 322 acquires brain images of the inside of the subject's head. A brain image is an image that includes the inside of the brain. The brain image is, for example, an MRI image, a CT image, or a PET image. The brain image acquisition unit 322 is, for example, a magnetic resonance imaging diagnostic device (MRI scanner), a computed tomography device (CT scanner), or a positron emission tomography device (PET scanner). The brain image acquisition unit 322 may acquire brain images from the storage unit 31 or an external device (not shown).

[0071] The OPM information acquisition unit 323 acquires, for each of the three or more optical pumping magnetometers 14, OPM information including an OPM position that specifies the relative position of the optical pumping magnetometer 14 with respect to a head reference point, which is a reference point of the subject's head, and an OPM direction of the optical pumping magnetometer 14, using the first information, the first singular point position, the three-dimensional image, and the brain image.

[0072] The OPM information acquisition unit 323 acquires OPM information using a first conversion means 3231, a second conversion means 3232, and an OPM information acquisition means 3233, which will be described below.

[0073] The first conversion means 3231 acquires second singularity positions that identify the positions of singularities corresponding to each of the three or more landmarks in the three-dimensional image acquired by the three-dimensional image acquisition unit 321. Next, the first conversion means 3231 converts the first positions of each of the three or more OPM sensors 14 into second positions that identify their positions in the three-dimensional image, using each of the three or more second singularity positions and each of the three or more first singularity positions. In other words, the first conversion means 3231 acquires, for each of the three or more OPM sensors 14, a second position that identifies the position of the OPM sensor 14 in the three-dimensional image.

[0074] The first conversion means 3231 converts the first position [x, y, z] of the OPM sensor 14 using the following formula 3 to obtain the second position [x', y', z']. In formula 3, T(α, β, γ, a, b, c) is a conversion matrix. α, β, γ, a, b, and c in the conversion matrix are constants. The conversion matrix is ​​stored in the storage unit 31. "R" in formula 3xyz " indicates the amount of rotation, and (a,b,c) indicates the amount of translation.

[0075]

number

[0076] The second transformation means 3232 acquires first subject positions that identify the position of each of one or more first subject reference points in the three-dimensional image. The second transformation means 3232 also acquires second subject positions that identify the position of each of one or more second subject reference points in the brain image. Next, the second transformation means 3232 transforms a second position [x', y', z'] in the three-dimensional image using each of one or more first subject positions and one or more second subject positions to acquire a third position [x'', y'', z''] of a point corresponding to the second position in the brain image. The third position corresponds to each of the three or more OPM sensors 14. Next, the second transformation means 3232 acquires an OPM position that identifies the relative position of each of the three or more OPM sensors 14 with respect to the head reference point in the brain image.

[0077] The first subject reference point is a reference point of the subject in the three-dimensional image. The second subject reference point is a reference point of the subject in the brain image. The first subject reference point and the second subject reference point are the same point on the subject. The first subject reference point and the second subject reference point are, for example, the root of the subject's nose and the tip of the subject's nose.

[0078] For example, the coordinates of the first subject's reference point in the rth 3D image are expressed as [x 0,r ,y 0,r ,z 0,r ], and the coordinate of the rth brain image is [x' 0,r ,y' 0,r ,z' 0,r ], the second transformation means 3232 performs, for example, rigid body transformation from the first subject position in the three-dimensional image to coordinates in the brain image using the following Equation 4.

[0079]

number

[0080] In addition, in Equation 4, the transformation sequence T is found by searching for α, β, γ, a, b, and c that minimize d in the following Equation 5. The simplex method is used to search for α, β, γ, a, b, and c. In Equation 5, R is the number of first subject reference points and second subject reference points. In Equation 5, [x m,r ,y m,r ,z m,r ] is the second subject position.

[0081]

number

[0082] The OPM information acquiring means 3233 acquires OPM information having the OPM position and OPM direction acquired by the second converting means 3232 for each of the three or more OPM sensors 14.

[0083] The storage unit 324 stores the OPM information acquired by the OPM information acquisition unit 323 for each of the three or more OPM sensors 14. The storage unit 324 stores the OPM information, for example, in association with a sensor identifier. The storage unit 324 stores the OPM information, for example, in the OPM management unit 21 of the measurement device 2. There is no restriction on where the storage unit 324 stores the OPM information.

[0084] The OPM management unit 21, storage unit 31, holder management unit 311, sensor coordinate management unit 312, and initial management unit 313 are preferably non-volatile recording media, but can also be realized as volatile recording media.

[0085] The process by which information is stored in the OPM management unit 21, etc. is not important. For example, information may be stored in the OPM management unit 21, etc. via a recording medium, information transmitted via a communication line, etc. may be stored in the OPM management unit 21, etc., or information input via an input device may be stored in the OPM management unit 21, etc.

[0086] The processing unit 22, magnetic force storage unit 221, processing unit 32, three-dimensional image acquisition unit 321, brain image acquisition unit 322, OPM information acquisition unit 323, first conversion means 3231, second conversion means 3232, OPM information acquisition means 3233, and storage unit 324 can typically be realized by a processor, memory, or the like. The processing procedures of the processing unit 22, etc. are typically realized by software, and the software is recorded on a recording medium such as a ROM. However, they may also be realized by hardware (dedicated circuitry). The processor may be a CPU, MPU, GPU, or the like, and the type is not important.

[0087] The three-dimensional image acquisition unit 321 is realized by, for example, a 3D scanner.

[0088] The brain image acquisition unit 322 is realized by, for example, an MRI scanner.

[0089] The output unit 23 may or may not include an output device such as a display, a speaker, etc. The output unit 23 may be realized by driver software for an output device, or a combination of driver software for an output device and the output device, etc.

[0090] Next, an example of the operation of the information acquisition device 3 constituting the magnetoencephalography measurement system A will be described with reference to the flowchart of FIG.

[0091] (Step S1301) The information acquisition device 3 determines whether or not to acquire initial information. If the initial information is to be acquired, the process proceeds to step S1302; if not, the process proceeds to step S1312. Note that the initial information is acquired when, for example, the information acquisition device 3 receives an instruction to acquire the initial information.

[0092] (Step S1302) The initial information acquiring unit 320 assigns 1 to a counter i.

[0093] (Step S1303) The initial information acquisition unit 320 determines whether or not the i-th holder 13 for which initial information is to be acquired is present in the helmet 1. If the i-th holder 13 is present, the process proceeds to step S1304, and if not, the process returns to step S1301.

[0094] (Step S1304) The initial information acquisition unit 320 acquires the holder position of the i-th holder 13 (for example, the coordinate values ​​of the four singular points in FIG. 11) from the holder management unit 311.

[0095] (Step S1305) The initial information acquisition unit 320 acquires a vector in the x direction using the holder position acquired in step S1304 and an arithmetic expression (see Equation 1).

[0096] (Step S1306) The initial information acquisition unit 320 acquires a vector in the y direction using the holder position acquired in step S1304 and an arithmetic expression (see Equation 1).

[0097] (Step S1307) The initial information acquisition unit 320 acquires a vector in the z direction using the holder position acquired in step S1304 and an arithmetic expression (see Equation 1).

[0098] (Step S1308) The initial information acquisition unit 320 acquires an OPM direction having a vector in the x direction, a vector in the y direction, and a vector in the z direction.

[0099] (Step S1309) The initial information acquiring unit 320 acquires the first position using the x-direction vector, the y-direction vector, the z-direction vector, and the arithmetic expression (see Equation 2).

[0100] (Step S1310) The initial information acquisition unit 320 acquires first information having a first position and an OPM direction. The initial information acquisition unit 320 stores the first information in association with an identifier that identifies the i-th holder 13. Note that the identifier that identifies the holder 13 may be a sensor identifier.

[0101] (Step S1311) The initial information acquisition unit 320 increments the counter i by 1. The process returns to step S1303.

[0102] (Step S1312) The information acquisition device 3 determines whether or not to acquire OPM information. If OPM information is to be acquired, the process proceeds to step S1313, and if not, the process returns to step S1301. Note that OPM information is acquired when, for example, an instruction to acquire OPM information is received.

[0103] (Step S1313) The information acquisition device 3 assigns 1 to the counter i.

[0104] (Step S1314) If the i-th OPM sensor 14 (holder 13) for acquiring OPM information exists, the information acquisition device 3 proceeds to step S1315, and if not, returns to step S1301.

[0105] (Step S1315) The first conversion unit 3231 acquires the first information corresponding to the i-th OPM sensor 14 (holder 13).

[0106] (Step S1316) The first conversion means 3231 acquires the first position included in the first information.

[0107] (Step S1317) The first conversion means 3231 acquires a conversion formula (see Equation 3) for converting the first position.

[0108] (Step S1318) The first conversion means 3231 converts the first position using a conversion formula to obtain a second position.

[0109] (Step S1319) The second conversion means 3232 acquires the first subject position in the three-dimensional image.

[0110] (Step S1320) The second conversion means 3232 acquires a second subject position of the brain image.

[0111] (Step S1321) Second conversion means 3232 acquires a conversion formula (see Equation 4) based on the first subject position and the second subject position.

[0112] (Step S1322) The second conversion means 3232 converts the second position using the conversion formula to obtain the OPM position.

[0113] (Step S1323) The second conversion means 3232 acquires the OPM direction included in the first information.

[0114] (Step S1324) The OPM information acquisition means 3233 acquires OPM information having an OPM position and an OPM direction.

[0115] (Step S1325) The OPM information acquiring means 3233 stores the OPM information in association with the identifier of the i-th OPM sensor 14.

[0116] (Step S1326) The information acquisition device 3 increments the counter i by 1. The process returns to step S1314.

[0117] In the flowchart of FIG. 13, the process ends when the power is turned off or an interrupt occurs to end the process.

[0118] As described above, according to this embodiment, it is possible to provide a helmet for measuring magnetoencephalograms, which places less restraint on the subject and causes less stress.

[0119] Furthermore, according to this embodiment, hair on the head can be protected.

[0120] Furthermore, according to this embodiment, it is possible to provide a magnetoencephalogram measurement system including a helmet on which the optically pumped magnetometer 14 for measuring the magnetoencephalogram is fixedly disposed.

[0121] Furthermore, according to this embodiment, the position of the optically pumped magnetometer 14 can be measured quickly and easily.

[0122] The processing in this embodiment may be realized by software. This software may be distributed by software download or the like. This software may also be recorded on a recording medium such as a CD-ROM and distributed. This also applies to the other embodiments in this specification. The software that realizes the information acquisition device 3 in this embodiment is the following program. That is, this program is a program for causing a computer to function that acquires OPM information used in a measurement device that includes: an OPM management unit that stores, for each of three or more optically pumped magnetometers, OPM information having an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction that specifies the direction of the optically pumped magnetometer; and a magnetic force storage unit that acquires, for each of the three or more optically pumped magnetometers, the magnetic force measured by the optically pumped magnetometer and stores the magnetic force in association with the OPM information, and the program causes a computer to function that acquires OPM information used in a measurement device that includes: an OPM management unit that stores, for each of three or more optically pumped magnetometers, OPM information having an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction that specifies the direction of the optically pumped magnetometer, and a magnetic force storage unit that acquires, for each of the three or more optically pumped magnetometers, the magnetic force measured by the optically pumped magnetometer and stores the magnetic force in association with the OPM information, and the program causes a computer to function that acquires OPM information used in a measurement device that includes: a main body unit; three or more fixing structures that fix the main body unit to the head of the subject; three or more optically pumped magnetometers; and a holder that holds each of the three or more optically pumped magnetometers. the computer is operable to function as a three-dimensional image acquisition unit that acquires three-dimensional images of the head of the subject wearing the helmet, a brain image acquisition unit that acquires brain images of the inside of the head of the subject, an OPM information acquisition unit that acquires, for each of the three or more optically pumped magnetometers, OPM information having an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction of the optically pumped magnetometer, and a storage unit that stores the OPM information acquired by the OPM information acquisition unit for each of the three or more optically pumped magnetometers,The OPM information acquisition unit is a program for causing the computer to function as comprising: first conversion means for acquiring second singularity positions that identify positions of singularities corresponding to each of the three or more landmarks in the three-dimensional image, and using each of the three or more second singularity positions and each of the three or more first singularity positions to convert a first position of each of the three or more optically pumped magnetometers into a second position that identifies a position in the three-dimensional image; second conversion means for acquiring a first subject position that identifies a position of a first subject reference point that is a reference point for the subject in the three-dimensional image, acquiring a second subject position that identifies a position of a second subject reference point that is the reference point for the subject in the brain image, and using the first subject position and the second subject position to convert the second position in the three-dimensional image to obtain an OPM position that identifies a relative position with respect to the head reference point in the brain image; and OPM information acquisition means for acquiring OPM information having the OPM position and OPM direction acquired by the second conversion means for each of the three or more optically pumped magnetometers.

[0123] 14 shows the appearance of a computer that executes the programs described herein to realize the information acquisition device 3 and the like according to the various embodiments described above. The above-described embodiments can be realized by computer hardware and a computer program executed thereon. FIG. 14 is an overview of this computer system 300, and FIG. 15 is a block diagram of the system 300.

[0124] In FIG. 14, a computer system 300 includes a computer 301 including a CD-ROM drive, a keyboard 302, a mouse 303, and a monitor 304.

[0125] 15, computer 301 includes, in addition to CD-ROM drive 3012, MPU 3013, bus 3014 connected to CD-ROM drive 3012 etc., ROM 3015 for storing programs such as a boot-up program, RAM 3016 connected to MPU 3013 for temporarily storing instructions of application programs and providing temporary storage space, and hard disk 3017 for storing application programs, system programs, and data. Although not shown here, computer 301 may further include a network card for providing connection to a LAN.

[0126] A program that causes computer system 300 to execute the functions of information acquisition device 3 and the like of the above-described embodiment may be stored on CD-ROM 3101, inserted into CD-ROM drive 3012, and then transferred to hard disk 3017. Alternatively, the program may be transmitted to computer 301 via a network (not shown) and stored on hard disk 3017. The program is loaded into RAM 3016 when executed. The program may also be loaded directly from CD-ROM 3101 or the network.

[0127] The program does not necessarily include an operating system (OS) or a third-party program that causes the computer 301 to execute the functions of the information acquisition device 3 of the above-described embodiment. The program only needs to include instructions that call appropriate functions (modules) in a controlled manner to achieve the desired results. How the computer system 300 operates is well known, and a detailed description thereof will be omitted.

[0128] The computer that executes the program may be a single computer or a plurality of computers, that is, it may perform centralized processing or distributed processing.

[0129] Furthermore, in each of the above embodiments, it goes without saying that two or more communication means present in one device may be physically realized by one medium.

[0130] Furthermore, in each of the above embodiments, each process may be realized by centralized processing in a single device, or may be realized by distributed processing in a plurality of devices.

[0131] The present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these modifications are also included within the scope of the present invention. [Industrial Applicability]

[0132] As described above, the helmet of the present invention is a helmet in which an optically pumped magnetometer for measuring magnetoencephalograms is fixed and positioned, and has the effect of providing a helmet that places less restraint on the subject and causes less stress, making it useful as a helmet for measuring magnetoencephalograms, etc. [Explanation of symbols]

[0133] 1 helmet 2. Measuring equipment 3 Information acquisition device 11 Main body 12 Fixed structure 13 Holder 14 Optically pumped magnetometer 15 Cap 21 OPM Management Department 22, 32 Processing section 23 Output section 31 Storage area 121 Male thread holder 122 Elastic Body 123 Pressing part 124 pads 221 Magnetic force storage unit 311 Holder Management Department 312 Sensor coordinate management unit 313 Initial Management Department 320 Initial information acquisition section 321 3D image acquisition unit 322 Brain Imaging Unit 323 OPM Information Acquisition Department 324 Storage Unit 3231 First Conversion Means 3232 Second conversion means 3233 OPM information acquisition means

Claims

1. A helmet for magnetoencephalography (MEG) measurement, comprising: a main body; two or more fixing structures for fixing the main body to a head of a subject; one or more optically pumped magnetometers for measuring magnetic force; and one or more holders for fixing the optically pumped magnetometers to the main body; The main body portion is The body is made of a non-elastic material and has a structure in which the fixing structure is inserted into each of three or more holes in the body, The fixing structure includes: A helmet having a structure fixed to the main body portion, having an elastic body made of a non-metallic material, and having the elastic body positioned between the head and the main body portion to bias the main body portion against the head.

2. a hole in the main body portion, the outer periphery of the hole into which the fixing structure is inserted having a female thread shape; the elastic body is a spring made of resin, The fixing structure includes:

2. The helmet according to claim 1, further comprising: a male screw holder having a male screw shape, which is inserted into the female screw on the outer periphery of the hole in the main body portion and fixed to the main body portion; the elastic body housed in the male screw holder; and a pad disposed between the elastic body and the head and which fixes the helmet to the head.

3. The fixing structure includes: The device further includes a pressing portion that is pressed toward the head side by the spring, The pressing portion is 3. The helmet according to claim 2, wherein the elastic body is disposed between the elastic body and the pad, and has a function of pressing the pad in a direction toward the head by the elastic body.

4. 2. The helmet according to claim 1, further comprising a stretchable cap that comes into contact with the subject's head.

5. 5. A magnetoencephalography (MEG) measurement system comprising: the helmet according to claim 1, which comprises the main body, two or more fixing structures, three or more optically pumped magnetometers, and three or more holders; and a measurement device, The measuring device is an OPM management unit in which OPM information is stored for each of the three or more optically pumped magnetometers, the OPM information including an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point on the head of the subject, and an OPM direction that specifies the direction of the optically pumped magnetometer; a magnetic force storage unit that acquires the magnetic force measured by each of the three or more optical pumping magnetometers and stores the magnetic force in association with the OPM information.

6. an OPM management unit in which OPM information is stored for each of the three or more optically pumped magnetometers, the OPM information including an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point on the head of the subject, and an OPM direction that specifies the direction of the optically pumped magnetometer; an information acquisition device for acquiring OPM information in a measurement device including a magnetic force storage unit that acquires a magnetic force measured by each of the three or more optical pumping magnetometers and stores the magnetic force in association with the OPM information, The information acquisition device an initial management unit in which first information is stored for each of the three or more optical pumping magnetometers, the first information having a first position specifying a position of each of the three or more optical pumping magnetometers and an OPM direction specifying a direction of each of the three or more optical pumping magnetometers relative to a helmet reference point that is a reference point of the helmet, the helmet comprising: a main body, three or more fixing structures for fixing the main body to the head of the subject, three or more optical pumping magnetometers, and a first singularity position specifying a position of a singularity corresponding to each of the three or more landmarks of the helmet; a three-dimensional image acquisition unit that acquires a three-dimensional image of the head of the subject wearing the helmet; a brain image acquisition unit that acquires brain images obtained by photographing the inside of the head of the subject; an OPM information acquisition unit that acquires, for each of the three or more optically pumped magnetometers, OPM information including an OPM position that specifies a relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction of the optically pumped magnetometer, using the first information, the first singularity position, the three-dimensional image, and the brain image; a storage unit for storing the OPM information acquired by the OPM information acquisition unit for each of the three or more optically pumped magnetometers; The OPM information acquisition unit a first conversion means for acquiring second singularity positions that identify positions of singularities corresponding to the three or more landmarks in the three-dimensional image, and converting first positions of the three or more optically pumped magnetometers into second positions that identify positions of the three or more optically pumped magnetometers in the three-dimensional image, using the three or more second singularity positions and the three or more first singularity positions; a second conversion means for acquiring a first subject position specifying the position of a first subject reference point that is a reference point of the subject in the three-dimensional image, acquiring a second subject position specifying the position of a second subject reference point that is the reference point of the subject in the brain image, and converting the second position in the three-dimensional image using the first subject position and the second subject position to acquire an OPM position specifying a relative position with respect to the head reference point in the brain image; an OPM information acquisition means for acquiring, for each of the three or more optically pumped magnetometers, OPM information having the OPM position and the OPM direction acquired by the second conversion means;

7. a holder management unit in which holder information is stored for each of the three or more optically pumped magnetometers, the holder information including a holder position that specifies the position of each of three or more singular points of the holder that can hold the optically pumped magnetometer, and an OPM direction that specifies the orientation of the optically pumped magnetometer when held in the holder; a sensor coordinate management unit in which a relative sensor position is stored, the relative sensor position being information specifying the sensor position, which is the measurement point of the magnetic force of the optical pumping magnetometer, and specifying the relative position with respect to the holder; an initial information acquiring unit for acquiring a first position of each of the three or more optically pumped magnetometers using the holder position and the relative sensor position, and acquiring first information having the first position and the OPM direction; The information acquisition device according to claim 6 , wherein the first information of the initial management unit is the first information acquired by the initial information acquisition unit.

8. 1. An information acquisition method for acquiring OPM information used in a measurement device comprising: an OPM management unit that stores OPM information for each of three or more optically pumped magnetometers, the OPM information having an OPM position that specifies a relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point on the head of a subject, and an OPM direction that specifies a direction of the optically pumped magnetometer; and a magnetic force storage unit that acquires a magnetic force measured by the optically pumped magnetometer for each of the three or more optically pumped magnetometers, and stores the magnetic force in association with the OPM information, an initial management unit in which first information having a first position specifying a position of each of the three or more optical pumping magnetometers and an OPM direction specifying a direction of each of the three or more optical pumping magnetometers relative to a helmet reference point that is a reference point of a helmet, the first information having a first position specifying a position of each of the three or more optical pumping magnetometers relative to a helmet reference point that is a reference point of the helmet, and an OPM direction specifying a direction of each of the three or more optical pumping magnetometers, is stored for each of the three or more optical pumping magnetometers, and a first singularity position specifying a position of a singularity corresponding to each of the three or more landmarks of the helmet is stored; a three-dimensional image acquisition unit; a brain image acquisition unit; an OPM information acquisition unit; and a storage unit, a three-dimensional image acquisition step in which the three-dimensional image acquisition unit acquires a three-dimensional image of the head of the subject wearing the helmet; a brain image acquiring step in which the brain image acquiring unit acquires a brain image capturing an inside of the head of the subject; an OPM information acquisition step in which the OPM information acquisition unit acquires, for each of the three or more optically pumped magnetometers, OPM information including an OPM position that specifies a relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction of the optically pumped magnetometer, using the first information, the first singularity position, the three-dimensional image, and the brain image; a storage step in which the storage unit stores the OPM information acquired by the OPM information acquisition unit for each of the three or more optically pumped magnetometers, The OPM information acquisition step includes: a first conversion substep of acquiring second singularity positions that identify positions of singularities corresponding to the three or more landmarks in the three-dimensional image, and converting first positions of the three or more optically pumped magnetometers into second positions that identify positions of the three or more optically pumped magnetometers in the three-dimensional image using the three or more second singularity positions and the three or more first singularity positions; a second transformation substep of acquiring a first subject position specifying the position of a first subject reference point that is a reference point for the subject in the three-dimensional image, acquiring a second subject position specifying the position of a second subject reference point that is the reference point for the subject in the brain image, and transforming the second position in the three-dimensional image using the first subject position and the second subject position to obtain an OPM position specifying a relative position with respect to the head reference point in the brain image; and an OPM information acquisition substep of acquiring, for each of the three or more optically pumped magnetometers, OPM information having the OPM position and the OPM direction acquired by the second conversion means.

9. an OPM management unit in which OPM information is stored for each of the three or more optically pumped magnetometers, the OPM information including an OPM position that specifies the relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point on the head of the subject, and an OPM direction that specifies the direction of the optically pumped magnetometer; a magnetic force storage unit that acquires a magnetic force measured by each of the three or more optical pumping magnetometers and stores the magnetic force in association with the OPM information, a helmet having a main body, three or more fixing structures for fixing the main body to the head of a subject, three or more optical pumping magnetometers, and a holder for holding each of the three or more optical pumping magnetometers, wherein first information having a first position specifying a position of each of the three or more optical pumping magnetometers and an OPM direction specifying a direction of each of the three or more optical pumping magnetometers relative to a helmet reference point that is a reference point of the helmet is stored for each of the three or more optical pumping magnetometers, and the computer is accessible to an initial management unit in which first singularity positions specifying a position of a singularity corresponding to each of the three or more landmarks of the helmet are stored; a three-dimensional image acquisition unit that acquires a three-dimensional image of the head of the subject wearing the helmet; a brain image acquisition unit that acquires brain images obtained by photographing the inside of the head of the subject; an OPM information acquisition unit that acquires, for each of the three or more optically pumped magnetometers, OPM information including an OPM position that specifies a relative position of the optically pumped magnetometer with respect to a head reference point that is a reference point of the head of the subject, and an OPM direction of the optically pumped magnetometer, using the first information, the first singularity position, the three-dimensional image, and the brain image; each of the three or more optically pumped magnetometers functions as a storage unit that stores the OPM information acquired by the OPM information acquisition unit; The OPM information acquisition unit a first conversion means for acquiring second singularity positions that identify positions of singularities corresponding to the three or more landmarks in the three-dimensional image, and converting first positions of the three or more optically pumped magnetometers into second positions that identify positions of the three or more optically pumped magnetometers in the three-dimensional image, using the three or more second singularity positions and the three or more first singularity positions; a second conversion means for acquiring a first subject position specifying the position of a first subject reference point that is a reference point of the subject in the three-dimensional image, acquiring a second subject position specifying the position of a second subject reference point that is the reference point of the subject in the brain image, and converting the second position in the three-dimensional image using the first subject position and the second subject position to acquire an OPM position specifying a relative position with respect to the head reference point in the brain image; A program for causing the computer to function as if it were equipped with an OPM information acquisition means for acquiring OPM information having the OPM position and the OPM direction acquired by the second conversion means for each of the three or more optically pumped magnetometers.

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