JP3705285B2 - Biomagnetic field measurement device - Google Patents

Description

  The present invention relates to a biomagnetic field measurement method and a biomagnetic field that measure a biomagnetic field generated by neural activity of the brain of a living body, myocardial activity of the heart, and the like using a plurality of magnetic flux meters composed of highly sensitive quantum interference elements (SQUIDs) It relates to a measuring device.

Conventionally, the results of biomagnetic field measurements have been displayed as isomagnetic field diagrams connecting the time-varying waveforms of the measured magnetic field components and the points where the magnetic field strength is equal at an arbitrary time. For example, it is known to measure the Z component (B _z ) in orthogonal coordinates or the same diameter component (B _r ) in polar coordinates and display the value of B _z or B _{r as} an isomagnetic field diagram. (H. Hosaka and D. Cohen, J. Electrocardiol., 9-4, 426 (1976)). In addition, the tangential component (B _x , B _y ) is measured in orthogonal coordinates and displayed as an isomagnetic field diagram for each component, or a two-dimensional magnetic field is represented by √ {(B _x ) ² , (B _y ) ² }. It is known to obtain vectors and display them as isomagnetic field diagrams (K. Tukada et al., Review of the Scientific Instruments, 66, 10 (1995)). Furthermore, a method is known in which after normal component B _z is measured, a magnetic field component equivalent to tangential component (B _x , B _y ) is analytically obtained from B _z (T. Miyashita et al., Proceedings). 20th International Conference IEEE / EMBS (Hong Kong), 520-523 (1998)).

Conventionally, analysis results of biomagnetic field components have been displayed using magnetic field time waveforms and isomagnetic field diagrams. In addition, the position, size, direction, etc. of the current source in the living body at an arbitrary time are estimated by solving the inverse problem, and using these, the initial excitation position of the arrhythmia in the heart and the focus of the eyelid in the brain It was used for position estimation. In order to track dynamic phenomena in a certain time zone, such as the excitement propagation process of the heart's myocardium and nerve excitement propagation in the brain, many isomagnetic field diagrams for each hour are displayed side by side, The locus of the current source vector estimated every time was displayed in one figure (N. Izumida et al., Japan Heart Journal, 731-742 (1998)).
H. Hosaka and D.H. Cohen, J .; Electrocardiol. , 9-4, 426 (1976) K. Tukada et al. , Review of the Scientific Instruments, 66, 10 (1995) T.A. Miyashita et al. , Proceedings 20th International Conference IEEE N. Izumida et al. , Japan Heart Journal, 731-742 (1998).

  Rather than arranging many isomagnetic field diagrams and analyzing dynamic excitation propagation of the heart and brain by pattern recognition, quantified graph display and graphic display for dynamic excitation propagation regardless of pattern recognition Was requested. In the method of estimating the current source at each moment, if the current source is localized, the current source can be estimated as a dipole model. However, in general, the current source is more widely distributed in the time zone. There are many. Moreover, when solving the inverse problem at each moment, many operations are required until the solution converges. In particular, when the degree of coincidence between the calculated magnetic field distribution created by the estimated current source and the actually measured magnetic field distribution is poor, the estimated value of the current source is degraded. For this reason, when the current source is estimated at each moment in a certain time zone, the estimation error becomes large, and an analysis result in which the continuity of the time change of the position, size, and direction of the current source is interrupted is given. was there.

  An object of the present invention is to provide a biomagnetic field measurement method and a biomagnetic field measurement apparatus capable of estimating the propagation process of electrophysiological excitation without displaying a dipole (magnetic field source) estimation and a large number of isomagnetic field diagrams. is there.

In the present invention, as a coordinate system in biomagnetic field measurement, an orthogonal coordinate system (x, y, z) (magnetic field components are represented as B _x , B _y , B _z ), a polar orthogonal coordinate system (r, θ, φ) ) Is used. When the measurement target is a heart or the like, an orthogonal coordinate system (x, y, z) with the chest wall as the xy plane is used. When the measurement target is the brain or the like, the head has a shape close to a sphere, so the polar orthogonal coordinate system (r, θ, φ) (the magnetic field components are B _r , B _θ , B _φ ) is used. It is done. The magnetic field component (normal component) perpendicular to the body surface of the head is represented by B _z and B _r , and the component parallel to the surface in contact with the surface of the living body (tangential component) is B _x , B _y , B _θ. , B _φ .

In the following description, the orthogonal coordinate system (x, y, z) will be described as an example. However, when the polar orthogonal coordinate system (r, θ, φ) is used, B _{z is set} to B _r and B _{x is set} to B. to _theta, to be replaced respectively _{B y} in B _phi.

  In the biomagnetic field measurement apparatus of the present invention, a biomagnetic field is measured from different directions using a set of sensor arrays. At this time, in order to analyze the measurement results of biomagnetic fields from multiple directions, (1) simultaneously with the measurement of biomagnetic fields in each direction, as a biosignal measurement device, an electrocardiograph, a heart sound meter, a pulse wave meter, an electroencephalograph Measure the biological signal generated periodically other than the biomagnetic field signal as a pair with the biomagnetic field signal, such as the electrocardiogram waveform, electrocardiogram, pulse waveform, brain waveform, etc. Or (2) Stimulate the nervous system by electrically stimulating a part of a living body with an electrical stimulator, generate sound with a sound stimulator and stimulate the auditory nervous system, generate odor with an odor stimulator Application of any stimulation signal, such as stimulating the olfactory nervous system, generating a light or color signal with a visual stimulator to stimulate the visual nervous system, or stimulating the skin with a tactile stimulator to stimulate the tactile nervous system A synchronization signal synchronized with the start of To the collection as a signal and a pair.

  A biomagnetic field emitted from the chest (hereinafter referred to as a cardiac magnetic field) is measured from, for example, two directions of the chest surface and back surface, or from four directions of the chest surface, back surface, right side surface of the chest, and left side surface. Of course, you may measure the biomagnetic field emitted from a chest other than these directions.

  A biomagnetic field (hereinafter referred to as a brain magnetic field) generated from the head (brain) by any one of the above stimuli, for example, from two directions, the front and rear of the head, or the front and rear of the head Measure from four directions from the right and left sides, or from five directions from the right and left sides of the head at the front and rear of the head and from the top of the head. Of course, you may measure the biomagnetic field emitted from a head from other than this direction.

  t is a time variable, and in the Cartesian coordinate system (x, y, z), x and y are coordinate positions where the individual sensors of the sensor array are arranged, a plane parallel to the surface in contact with the surface of the living body, xy plane, Let z be the axis perpendicular to the surface in contact with the surface of the living body.

For biomagnetic field waveforms measured from different directions, the following processing is performed for each direction. When a biological signal generated periodically is measured and collected as a pair with a biomagnetic field signal, the biological signal measured from a plurality of directions m = 1, 2,. The time of the waveform W _m (t) (m = 1, 2,..., M) of each measured biological signal so that the time axis of the waveform W _m (t) has a common origin (t = 0). A transformation T _m (m = 1, 2,..., M) is performed on the axis. Transform T _m (m = 1, 2,..., M) with respect to the time axis of the waveform F _m (m = 1, 2,..., M) of the biomagnetic field signal paired with the biological signal W _m (t) Perform the conversion. When the synchronization signal synchronized with the start of application of the stimulation signal is collected as a pair with the biomagnetic field signal, the waveform Fm of the biomagnetic field signal measured from a plurality of directions of m = 1, 2 _,. The time axis conversion T _m ′ (m = 1) so that the time axes of (m = 1, 2,..., M) have a common origin (t = 0) at the time when the synchronization signal is collected. , 2, ..., M). The above transformations T _m , T _m ′ (m = 1, 2,..., M) are transformations of parallel movement of the time axis.

  The following arithmetic processing is performed for each of the waveforms of the biomagnetic field (cardiac magnetic field or brain magnetic field) measured from a plurality of directions having a common origin (t = 0).

When measuring the magnetic field component B _z (x, y, t) perpendicular to the surface in contact with the surface of the living body as the biomagnetic field, the amount of change in the x direction of the perpendicular magnetic field component B _z (x, y, t) , ∂B _z (x, y, t) / ∂x and the amount of change in the y direction of B _z (x, y, t), ∂B _z (x, y, t) / ∂y, According to the equations (1) and (2), the square root of the sum of squares, that is, the magnitude of the two-dimensional magnetic field vector I (x, y, t) (hereinafter simply referred to as vector intensity) and its phase θ (x, y , T) are respectively calculated.

I (x, y, t) = √ {(∂B _z (x, y, t) / ∂x) ² + (∂B _z (x, y, t) / ∂y) ² } (Equation 1)

θ (x, y, t) = − tan ⁻¹ {(−∂B _z (x, y, t) / ∂x) / (∂B _z (x, y, t) / ∂y)} (number 2)
Tangential component of the magnetic field emanating from the living body (a component parallel to the surface in contact with the surface of the living body) B _x, when measuring the B _y is (number 3), the equation (4), the tangential components B _x and B _y 2
Arithmetic processing for obtaining the vector intensity I (x, y, t) and its phase θ (x, y, t) from the square root of the sum of multiplication is performed.

I (x, y, t) = √ {(B _x (x, y, t)) ² + (B _y (x, y, t)) ² }
(Equation 3)

θ (x, y, t) = − tan ⁻¹ {−B _x (x, y, t) / B _y (x, y, t)}
... (Equation 4)
Next, the maximum vector intensity I _max (x _i , y _j , t) and the phase θ (x _i , y _j , t) at each time t of the measured biomagnetic field (cardiac magnetic field or brain magnetic field) are calculated. Ask. At time t, at the i-th x coordinate position of the sensor, the j-th y coordinate position, ie, in the (i, j) channel, the vector intensity I (x, y, t) is maximized. give. The maximum vector intensity I _max (x _i , y _j , t) and the phase θ (x _i , y _j , t) at each time t obtained are displayed for the time variable t. This display is referred to as a time-intensity plot (t-I _max ) and a time-phase plot (t-θ).

As a result, a time-intensity plot (t-I _max ) is obtained from a waveform of a biomagnetic field (cardiac magnetic field or brain magnetic field) signal measured from a plurality of directions and having a common common time origin (t = 0). , And a time-phase plot (t-θ). As a result, the time-intensity plot (t-I _max ) and the time-phase plot (t-θ) can be compared and displayed for each measurement surface of the biomagnetic field.

In addition, the positions (x _i , y) of all sensors obtained from the waveform of the signal of the biomagnetic field (cardiac magnetic field or brain magnetic field) measured from a plurality of directions and having a common common time origin (t = 0). _j ), that is, the vector intensity I (x, y, t) and its phase θ (x, y, t) in all channels can be displayed on the same display screen. This display is referred to as a time-phase / intensity plot (t-θ · I). In this display, the phase θ (x, y, t) is plotted against the time variable t, and the vector intensity I (x, y, t) is the plotted color, the shade of the plotted color, or the plotted symbol. Is changed in accordance with the vector intensity I (x, y, t) and displayed.

  As described above, the electrophysiological excitation propagation process can be measured by measuring the cardiac magnetic field or the brain magnetic field from multiple directions without performing dipole estimation or displaying many isomagnetic field diagrams. Can be quantified and displayed.

  According to the biomagnetic field measurement apparatus of the present invention, since the vector intensity and its phase are used, without solving the inverse problem and estimating the dipole (magnetic field source), and without displaying many isomagnetic field diagrams, Electrophysiological excitement propagation process can be quantified, and individual diseases and abnormalities can be grasped objectively and quantitatively.

  In the biomagnetic field measurement apparatus according to the embodiment of the present invention, a biomagnetic field generated from a living body is measured by a plurality of SQUID magnetometers. At this time, a biological signal measuring device that measures and collects biological signals generated periodically other than the biological magnetic field, or a stimulation signal that stimulates any of the various nervous systems and the start of application of this stimulation signal are synchronized. Use a stimulator that generates a synchronization signal.

  Biomagnetic field signals and biosignals that are simultaneously measured and collected as pairs from multiple directions, or biomagnetic field signals that are measured and collected from multiple directions as a pair with a synchronization signal synchronized with the start of application of a stimulus signal, The arithmetic processing unit performs arithmetic processing, and the arithmetic processing result is displayed on the display device.

  The arithmetic processing unit performs time axis conversion for translating the time axis of the biomagnetic field signal so that the biomagnetic field signals measured and collected from a plurality of directions have a common origin (t = 0). Arithmetic processing is performed on a biomagnetic field signal having an origin (t = 0).

  When the biological signal measuring device is used, the time axis conversion is performed so that the time axis of the biological signal measured from a plurality of directions has a common origin (t = 0) with the time variable t. Conversion of the time axis of the signal waveform is performed. At this time, the same conversion is performed for the time axis of the waveform of the biomagnetic field signal paired with the biosignal. When using a stimulator, time axis conversion is performed so that the time axis of the biomagnetic field signal measured from multiple directions has a common origin (t = 0) when the synchronization signal is collected. Is done.

  In another embodiment of the present invention, the arithmetic processing unit uses a signal of a biomagnetic field (cardiac magnetic field or brain magnetic field) having a common origin (t = 0) in a direction perpendicular to the surface in contact with the surface of the living body. Are the z direction, the x direction and the y direction are the directions perpendicular to the z direction and in contact with the surface of the living body, and the magnitude of the two-dimensional magnetic field vector and / or xy at each measurement point (x, y) of the biomagnetic field An angle representing the direction on the surface is obtained. On the display device, the time change of the magnitude and / or angle of the two-dimensional magnetic field vector with the common origin (t = 0) as the origin is displayed.

  A biomagnetic field measurement apparatus according to another embodiment of the present invention includes a plurality of SQUID magnetometers that measure a biomagnetic field (cardiac magnetic field or brain magnetic field) signal generated from the chest or head of a living body, and calculation of the biomagnetic field signal. An arithmetic processing device that performs processing and a display device that displays the result of the arithmetic processing are provided.

  The arithmetic processing unit determines the direction of the biomagnetic field from the biomagnetic field signal, with the direction perpendicular to the surface in contact with the surface of the living body as the z direction and the direction perpendicular to the z direction and horizontal to the surface in contact with the surface of the living body as the x direction and y direction. A two-dimensional magnetic field vector at each measurement point (x, y) is obtained, and the magnitude and / or xy plane of the maximum two-dimensional magnetic field vector among the two-dimensional magnetic field vectors at a plurality of measurement points (x, y). The angle representing the direction at is obtained at a plurality of time points when the biomagnetic field is measured. And the magnitude | size of the largest two-dimensional magnetic field vector and / or time change of an angle are displayed on a display apparatus.

  In another embodiment, the magnitude and angle of the two-dimensional magnetic field vector at each measurement point (x, y) are obtained at a plurality of time points when the biomagnetic field is measured. Then, the time change of the angle representing the direction on the xy plane and the magnitude of the two-dimensional magnetic field vector at each measurement point (x, y) is displayed on the display device. It is displayed in proportion to the depth or by color.

  A biomagnetic field measurement apparatus according to another embodiment of the present invention includes a plurality of SQUID magnetometers that measure a biomagnetic field signal generated from the head of a living body, a signal that stimulates the living body, and a signal that stimulates the living body. A stimulator that generates a synchronization signal that is synchronized with the start of the signal, an arithmetic processing device that performs arithmetic processing on signals of the biomagnetic field (brain magnetic field) measured from multiple directions of the head of the living body, and displays the results of the arithmetic processing A display device.

  The arithmetic processing unit has a direction perpendicular to the surface in contact with the surface of the living body in the z direction, a direction orthogonal to the z direction and horizontal to the surface in contact with the surface of the living body in the x direction and the y direction, and a time variable as t. The time axis of the waveform of the biological signal measured from a plurality of directions is performed based on the synchronization signal so that the time axis of the waveform of the biological signal measured from 1 has a common origin (t = 0).

Further, for a plurality of directions in which the biomagnetic field is measured, a two-dimensional magnetic field vector at each measurement point (x, y) of the biomagnetic field is obtained from a biomagnetic field signal having a common origin (t = 0), and a plurality of measurement points are obtained. The angle representing the magnitude of the maximum two-dimensional magnetic field vector and / or the direction on the xy plane among the two-dimensional magnetic field vectors at (x, y) is represented on the time axis with the common origin (t = 0) as the origin. Find at each point. Then, the maximum two-dimensional magnetic field vector magnitude and / or angle change over time is displayed on the display device in a plurality of directions in which the biomagnetic field is measured.
(First embodiment)
FIG. 1 is a perspective view illustrating a schematic configuration of a biomagnetic field measurement apparatus according to a first embodiment of the present invention. A biomagnetic field measurement apparatus that measures a magnetic field (cardiac magnetic field) generated from the heart (hereinafter referred to as a cardiac magnetic field measurement) uses a plurality of magnetic field sensors composed of quantum interference elements (SQUIDs). In order to remove the influence of environmental magnetic field noise, the cardiac magnetic field measurement is performed inside the magnetic field shield room 1. The subject 2 lies on the bed 4.

  Here, the orthogonal coordinate system (x, y, z) is set so that the xy plane becomes the plane of the bed. A dewar 3 that houses a plurality of magnetic field sensors in which a SQUID and a detection coil connected to the SQUID are integrated and filled with liquid He is disposed above the subject 2. The dewar 3 is fixed to the floor by a gantry 5. The output from the magnetic field sensor is input to an FLL (Flux Locked Loop) circuit 8 that outputs a voltage proportional to the magnetic field intensity detected by the detection coil.

  The FFL circuit 8 cancels the change of the biomagnetic field input to the SQUID through the feedback coil so as to keep the output of the SQUID constant. By converting the current passed through the feedback coil into a voltage, a voltage output proportional to the change in the biomagnetic field signal can be obtained. This voltage output is amplified by the amplifier of the amplifier filter circuit 9, the frequency band is selected by the filter circuit, and AD-converted by the data recording analysis device (arithmetic processing device) 10 to record the data.

  In the data recording / analyzing apparatus 10, various arithmetic processes are executed, and the arithmetic processing results are displayed on the display 11 and further output by a printer. Electrocardiograms are measured simultaneously with the measurement of the electrocardiogram. Electrocardiograph electrodes 6 are attached to the wrist and ankle of the subject 2, and the electric potential due to limb induction is guided to the electrocardiograph 7. The output of the electrocardiograph 7 is input to the amplifier filter circuit 9 of the biomagnetic field measurement device, the amplification and frequency band are selected, and the arithmetic processing is performed in the same manner as the electrocardiogram, and the electrocardiogram waveform is displayed on the display 11. When the measurement of the cardiac magnetic field is performed from the front and back, the subject is in a supine and prone state, and the cardiac magnetic field is measured.

  FIG. 2 is a perspective view for explaining the arrangement of the magnetic field sensors in the first embodiment of the present invention. The coil for detecting the normal component of the biomagnetic field has a plane perpendicular to the z direction. Magnetic field sensor 20-i (i = 11, 12,..., 18; i = 21, 22,..., 28; i = 31, 32,..., 38; i = 41, 42,. , 58; i = 61, 62, ..., 68; i = 71, 72, ..., 78; i = 81, 82, ..., 88) are vertically installed from the bottom inside the dewar. . The distances between the sensors were arranged at equal intervals (25 mm) in the x and y directions so as to accurately determine the amount of change in the normal component of the biomagnetic field in the x and y directions. Eight sensors each in the x and y directions were arranged in a square lattice pattern to provide 64 channels.

FIG. 3 is a perspective view for explaining the configuration of the magnetic field sensor for detecting the normal component of the biomagnetic field in the first embodiment of the present invention. The magnetic field sensor 20 is a sensor that measures a component _Bz perpendicular to the body surface, and a coil made of a superconducting wire (Nb-Ti wire) has a surface perpendicular to the z direction. This coil is a combination of two coils facing in opposite directions. The first derivative is formed by a detection coil 22 disposed at a position close to the living body and a reference coil 23 disposed at a position far from the living body to remove external magnetic field noise. A coil is formed. The coil diameters of the detection coil 22 and the reference coil 23 were 20 mmφ, and the distance (baseline) between the coils of the detection coil 22 and the reference coil 23 was 50 mm.

  External magnetic field noise is generated from a signal source far from the living body, and these are detected in the same manner by the detection coil 22 and the reference coil 23. On the other hand, since the magnetic field source in the living body is close to the coil, the biological magnetic field is detected more strongly by the detection coil 22. The detection coil 22 detects a biomagnetic field signal and external magnetic field noise, and the reference coil 23 detects only external magnetic field noise. Therefore, measurement with a higher S / N can be performed from the difference between the magnetic fields detected by both coils. The primary differential coil is connected to the input coil of the SQUID via the superconducting wiring of the mounting substrate on which the SQUID 21 is mounted, and the biomagnetic field signal detected by the coil is transmitted to the SQUID.

  A dewar with a built-in magnetic field sensor is placed above the subject lying on the bed, and the cardiac magnetic field generated from the heart is measured. Here, the direction of the body axis is the y-axis, and the x-axis is orthogonal to the y-axis.

  FIG. 4 is a diagram for explaining the positional relationship between the arrangement of the magnetic field sensor and the front and back of the chest of the subject 2 in the first embodiment of the present invention. In FIG. 4, white circles indicate positions where magnetic field sensors are arranged in an 8 × 8 array, that is, magnetic field measurement points 30. The measurement reference point 31 on the front of the chest of the subject 2 and the measurement reference point 31 ′ on the back are the same on the xy coordinates. In the example shown in FIG. 4, the measurement reference points 31 on the front face correspond to the magnetic field sensors located in the second row and the third column from the left on the measurement surface, and the measurement reference points are located in the second row and the sixth column on the back surface. Corresponds to magnetic field sensor. However, the coordinate system on the back surface takes the x coordinate opposite to the coordinate system on the front surface. For example, a magnetic field sensor located in one row and one column on the front corresponds to a magnetic field sensor located in one row and eight columns on the back, and a magnetic field sensor located on eight rows and eight columns on the front is Corresponds to a magnetic field sensor located in 8 rows and 1 column.

  FIG. 5 is a perspective view for explaining a method of aligning the arrangement of the magnetic field sensor and the position of the human chest in the first embodiment of the present invention. Various mechanisms and methods for aligning the measurement reference point 31 of the sensor array with the reference point 40 of the subject are known. In the example shown in FIG. 5, an x-direction laser light source 41 that generates a fan-shaped x-axis line forming beam 43 in a plane parallel to the xz plane of the orthogonal coordinate system, and a plane parallel to the yz plane of the orthogonal coordinate system. A y-direction laser light source 42 that generates a fan-shaped y-axis line forming beam 44 is used for alignment. On the outer peripheral surface of the dewar 3, an xz mark (mark) 45 indicating the position of the xz plane of the orthogonal coordinate system and a yz mark (mark) 46 indicating the position of the yz plane of the orthogonal coordinate system are marked.

  The x-axis line forming beam 43 is irradiated on the outer peripheral surfaces of the subject 2 and the dewar 3 so as to irradiate the reference point 40 set on the body surface of the subject and the xz mark (mark) 45 of the dewar 3. The position of the x direction laser light source 41 is adjusted. Similarly, the y-axis line forming beam 44 is applied to the outer peripheral surfaces of the subject 2 and the dewar 3, and the reference point 40 set on the body surface of the subject and the yz mark (mark) 46 of the dewar 3 are displayed. The position of the y-direction laser light source 42 is adjusted so as to irradiate. Thereby, a sensor and the position of a biological body can be adjusted. The beams 43 and 44 intersect to form an intersecting line 49 parallel to the z-axis.

FIG. 6 is a diagram for explaining the flow of measurement of the biomagnetic field and analysis of the measured signal in the first embodiment of the present invention. In the analysis shown in FIG. 6, the maximum vector at each time of the measured cardiac magnetic field is selected. First, the magnetocardiogram is measured from the front and back directions. Measuring the normal component B _z of the cardiac magnetic field. Electrocardiograms are measured simultaneously with the measurement of the magnetocardiogram. Next, the time axis is adjusted so that the waveforms of the electrocardiogram measured simultaneously with the measurement of the magnetocardiogram from the front and back surfaces become the same waveform at the same time. That is, the time axis of each electrocardiogram is translated so that the same time phase in each measured electrocardiogram becomes the same time. The time axis of the measurement data of the electrocardiogram based on the electrocardiogram data (hereinafter referred to as the electrocardiogram waveform) is set by applying the parallel movement of the time axis adjusted for each electrocardiogram to the corresponding electrocardiogram measurement data.

Next, as described with reference to FIG. 4, in order to correlate the measurement data of the magnetocardiogram on the front and back, the x coordinate on the back is inverted to change the correspondence between the position of the sensor array and the measurement data. Next, the amount of change ∂B _z (x, y, t) / ∂x in the x direction of the magnetic field component B _z (x, y, t) perpendicular to the measured biological surface, and B _z (x, y , T) in the direction of change ∂B _z (x, y, t) / ∂ y is obtained by calculation, and the vector intensity I (x, y at 64 observation points measured on the front and back sides, respectively. , T) based on (Equation 1) and vector phase θ (x, y, t) based on (Equation 2).

Next, the maximum vector of the vector intensity I (x, y, t) is extracted at each time t for each measurement surface (front, back) of the cardiac magnetic field. That is, the maximum vector intensity I _max (x _i , y _j , t at each time t of the vector intensity I (x, y, t) obtained from the measurement data of the cardiac magnetic field on each of the front and back surfaces. ) And its phase θ (x _i , y _j , t). Next, the maximum vector intensity I _max (x _i , y _j , t) and its phase θ (x _i , y _j , t) at each time t obtained are displayed for the time variable t. That is, a time-intensity plot (t-I _max ) and a time-phase plot (t-θ) are displayed for each measurement surface (front and back) of the cardiac magnetic field. Hereinafter, a specific example obtained based on the flowchart of FIG. 6 will be described.

  FIG. 7 is a diagram showing an example of the electrocardiogram waveform measured from the front and the back, and the electrocardiogram waveform measured simultaneously with the measurement of the electrocardiogram waveform, with a healthy subject as the subject. In FIG. 7, the cardiac magnetic field waveform is displayed by superimposing all the time waveforms of 64 channels, and the electrocardiogram waveform shows the waveform of the second induction. In order to adjust the time axis of the magnetocardiogram waveform measured from the front and back, the time T1 of the start point of the time zone in which the ventricle called the QRS wave of the electrocardiogram measured during the electrocardiogram measurement from the front is depolarized Is set to 0. Next, the time T2 of the start point of the QRS wave of the electrocardiogram waveform measured at the time of measuring the magnetocardiogram from the back is set to 0, and the time axes of the two electrocardiogram waveforms are aligned. The time origin of the magnetocardiogram waveform from the front is set to t = T1 = 0, and the time origin of the magnetocardiogram waveform from the back is set to t = T2 = 0.

  FIG. 8 shows the current at the time after 30 ms from the start point of the QRS wave, which is the process of depolarizing the ventricle of the heart magnetic field waveform of the healthy subject measured from the front in the first embodiment of the present invention. It is an arrow figure and a figure showing a maximum current vector. The size of each arrow at 64 measurement points indicates the vector intensity based on (Equation 1), and the phase is calculated based on (Equation 2). The largest vector among the 64 vectors is selected as the maximum vector.

  FIG. 9 is a diagram showing a reference for the phase θ of the maximum vector in the first embodiment of the present invention. In FIG. 9, the positive direction (right direction) of the x-axis is θ = 0 degrees, the clockwise direction is the positive direction of the phase, and the counterclockwise direction is the negative direction of the phase.

FIG. 10 shows a time period from the start point of QRS wave to 200 ms, which is the process of depolarizing the ventricle of the heart magnetic field waveform of a healthy person measured from the front and back in the first embodiment of the present invention. time in - the intensity plot _{(t-I max),} time - is a view showing a display example of a phase plot (t-θ). The maximum vector intensity (pT / cm) obtained from the magnetocardiogram waveforms measured from the front and back surfaces, and the phase change over time show different patterns. However, the maximum vector intensity (pT / cm) is common in that it shows a pattern having a large value in a time zone from about 20 ms to about 100 ms from the start point of the QRS wave.

  Next, the measurement example regarding the patient of the right leg block among the leg blocks having stimulation conduction disorder in the ventricle will be described.

FIG. 11 shows the first embodiment of the present invention, from the start of the QRS wave, which is the process of depolarizing the ventricle of the magnetocardiogram waveform of the right leg block patient measured from the front and back to 200 ms. the time in hours - the intensity plot (t-I _max), time - is a view showing a display example of a phase plot (t-θ). Unlike the case of the healthy person shown in FIG. 10, the vector intensity obtained from the cardiac magnetic field waveform measured from the front shows a large value over a long time period of about 160 ms after about 60 ms from the QRS wave start point. It can be seen that the heart activity time is also long. In addition, when the time change of the phase obtained from the cardiac magnetic field waveform measured from the front is compared with the case of the healthy person shown in FIG. 10, the change in the initial time zone from the start point of the QRS wave is It can be seen that it is smaller than the case. Thus, abnormalities in the propagation of excitement of the heart can be easily discriminated by the present invention.
(Second embodiment)
In the second embodiment of the present invention, in addition to the display of the time-intensity plot (t-I _max ) and the time-phase plot (t-θ) for each measurement surface (front, back) of the cardiac magnetic field,
Data of all the magnetocardiographic waveforms of 64 channels are displayed.

  In the second embodiment of the present invention, the biomagnetic field is measured and measured when performing the time-phase / intensity plot (t-θ · I) of the vector at each time of all 64 channels in the second embodiment of the present invention. It is a figure explaining the flow of an analysis of the received signal. In the flowchart shown in FIG. 12, the processing up to obtaining the vector intensity and the phase at each measurement point (channel) is the same as in FIG. In the flowchart shown in FIG. 12, the time-phase / intensity of vectors in all 64 channels obtained directly from the cardiac magnetic field data measured from the front and back without selecting the maximum vector. A plot (t−θ · I) is displayed.

  FIG. 13 shows 64 channels in the time zone from the QRS start point to 200 ms, which is the process of depolarizing the ventricle of the cardiac magnetic field waveform measured from the front of the healthy subject in the second embodiment of the present invention. It is a figure which shows the example of a display of the time-phase intensity | strength plot of the vector of all the channels.

  FIG. 14 shows 64 channels in the time zone from the QRS start point to 200 ms, which is the process of depolarizing the ventricle of the cardiac magnetic field waveform measured from the back of the healthy subject in the second embodiment of the present invention. It is a figure which shows the example of a display of the time-phase intensity | strength plot of the vector of all the channels.

  FIG. 15 shows a time period from the start point of the QRS wave to 200 ms, which is the process of depolarizing the ventricle of the magnetocardiogram waveform of the right leg block patient measured from the front in the second embodiment of the present invention. It is a figure which shows the example of a display of the time-phase intensity | strength plot of the vector of all the channels of 64 channels. A large difference can be recognized at a glance between the plot pattern of FIG. 15 and the plot pattern of FIG.

  FIG. 16 shows a time period from the start point of the QRS wave to 200 ms, which is the process of depolarizing the ventricle of the magnetocardiogram waveform of the right leg block patient measured from the back in the second embodiment of the present invention. It is a figure which shows the example of a display of the time-phase intensity | strength plot of the vector of all the channels of 64 channels. A large difference can be recognized at a glance between the plot pattern of FIG. 16 and the plot pattern of FIG.

In FIG. 13 to FIG. 16, the pattern is displayed easily because the phase is displayed as the vertical axis by distinguishing by the density of the plot points that display the vector intensity at each of the 64 measurement points at each time. Can be identified. In addition to displaying the intensity of the plot points as vector intensity, it is also possible to display the difference in color (color scale) of the plot points and the size of the plot points. With such a plot, it is possible to easily detect a difference from a healthy person.
(Third embodiment)
In the third embodiment, magnetic field components in the x direction and y direction of the biomagnetic field are measured.

Figure 17 is a diagram for explaining a third tangential components B _x biomagnetic field to be employed in the _Examples, and outline of a configuration example of a magnetic field sensor for detecting the B _y component of the present invention. A magnetic field sensor 20 ′ shown in FIG. 17 uses a planar coil.

  In the sensor for measuring the magnetic field in the x direction, the detection coil 22'-1 and the reference coil 23'-1 are arranged side by side on one plane, and constitute a primary differential coil for measuring the magnetic field in the x direction. The size of the coils of the detection coil 22′-1 and the reference coil 23′-1 is a square of 20 mm × 20 mm, and the distance between the centers of the respective coils of the detection coil 22′-1 and the reference coil 23′-1 (baseline ) Was 50 mm. The primary differential coil for measuring the magnetic field in the x direction is connected to the SQUID input coil via the superconducting wiring of the mounting board on which SQUID 21-1 'is mounted, and the biomagnetic field signal detected by the coil is transmitted to the SQUID. .

  In the sensor for measuring the magnetic field in the y direction, the detection coil 22'-2 and the reference coil 23'-2 are arranged side by side on one plane to constitute a primary differential coil for measuring the magnetic field in the y direction. The size of the coils of the detection coil 22′-2 and the reference coil 23′-2 is a square of 20 mm × 20 mm, and the distance between the centers of the coils of the detection coil 22′-2 and the reference coil 23′-2 (baseline ) Was 50 mm. The primary differential coil for measuring the magnetic field in the y direction is connected to the SQUID input coil via the superconducting wiring of the mounting substrate on which SQUID 21-2 ′ is mounted, and the biomagnetic field signal detected by the coil is transmitted to the SQUID. .

A magnetic field sensor capable of measuring the x-component and y-component of the biomagnetic field by attaching the x-component detection magnetic field sensor and the y-component detection magnetic field sensor to two orthogonal surfaces of a quadrangular prism support. Is forming. Magnetic field sensors having a quadrangular prism shape as shown in FIG. 17 are arranged in a sensor array as shown in FIG. Based on the measured tangential components B _x and B _y , the vector intensity I (x, y, t) is obtained based on (Equation 3), and the phase θ (x, y, t) is obtained on the basis of (Equation 4).

As described with reference to FIGS. 6 and 12, instead of obtaining the differential in the x direction and the y direction of the normal component of the biomagnetic field, it is based on (Equation 3) and (Equation 4) from the two measured tangential components. Using the vector intensity I (x, y, t) and the phase θ (x, y, t) obtained in the same manner as in the first and second embodiments described above, the maximum vector Time-intensity plot (t-I _max ) and time-phase plot (t-θ), or time-phase / intensity plot (t-θ · I) for all 64 channels can be obtained and displayed. .
(Fourth embodiment)
In the fourth embodiment, the first-order differential components of the normal component in the x direction and the y direction are directly measured and analyzed using a planar differential coil.

  FIG. 18 shows a semicircular coil formed side by side with linear portions through which currents flow in opposite directions when a magnetic field is incident on the coil from the same direction, which is used in the fourth embodiment of the present invention. FIG. 5 is a diagram showing an example of the shape of the differential coil 50 having a circular shape as a whole coil. 18 can detect a value obtained by differentiating a magnetic field in a direction orthogonal to a straight line portion through which currents flowing in opposite directions flow. A differential coil 50 is provided on a mounting board on which SQUID 21 ″ is mounted. The biomagnetic field signal detected by the differential coil is connected to the SQUID input coil via the superconducting wiring and transmitted to the SQUID. A plane type differential coil having a straight line portion in which currents flowing in opposite directions flow in the x direction and a plane type differential coil having in the y direction are prepared.

By arranging a planar differential coil for detecting differential components in the x and y directions at each measurement point of the sensor array as shown in FIG. 2, the normal component of the biomagnetic field at each of the 64 measurement points. The differential values in the x and y directions can be directly measured. From the measured differential values in the x and y directions, the vector intensity I (x, y, t) is obtained based on (Equation 1), and the phase θ (x, y, t) is obtained based on (Equation 2). ) Similar to the first to third embodiments described above, the maximum vector time-intensity plot (t-I _max ) and time-phase plot (t-θ), or 64 channels Time-phase / intensity plots (t-θ · I) for all channels can be obtained and displayed.
(Fifth embodiment)
FIG. 19 is a diagram for explaining an outline of a configuration example of a biomagnetic field measurement apparatus that performs cardiac magnetic field measurement simultaneously from the front and back directions used in the fifth embodiment of the present invention. In the configuration example of the biomagnetic field measurement apparatus of the fifth embodiment, it is not necessary for the subject 2 to change the posture in order to measure the cardiac magnetic field from the front and back directions, and the cardiac magnetic field is measured from two directions at the same time. it can. Two dewars, an upper dewar 3′-1 and a lower dewar 3′-2, are provided, and each sensor array as described in the first to fourth embodiments is arranged. The upper dewar 3′-1 and the lower dewar 3′-2 are held by the gantry 5 ′. A pulley 13 that can move in the horizontal direction is attached to the leg of the bed 4 '. After the subject 2 gets on the bed 4 ′, the bed 4 ′ is moved along the rail 12 to a fixed position between the upper dewar 3′-1 and the lower dewar 3′-2. Since the cardiac magnetic field can be measured simultaneously from two directions from the sensor array disposed above and below the subject 2 without measuring periodic biological signals such as an electrocardiogram, the time of the data of the cardiac magnetic field measured from the two directions There is no need to adjust the axis.
(Sixth embodiment)
In the sixth embodiment, a magnetic field (brain magnetic field) induced by auditory sensation by sound stimulation is measured. FIG. 20 is a perspective view for explaining a configuration example of a biomagnetic field measuring apparatus for measuring an auditory-induced brain magnetic field in the sixth embodiment of the present invention. The subject lies on the bed 4, the surface of the head to be measured is brought close to the bottom surface of the dewar 3, and the cerebral magnetic field is measured.

  In the configuration shown in FIG. 20, a tone burst sound having a 50 ms holding time width at 1 kHz is generated by the sound stimulator 183. The interval between sound stimuli is 0.3 Hz (frequency about once every 3.3 seconds). A synchronization signal 184 is generated in accordance with the application timing of the sound stimulus, and the synchronization signal 184 is input to the data recording analysis device (arithmetic processing device) 10. Using the input synchronization signal 184, the time axis of the brain magnetic field waveform is matched, and then the averaging process is performed to improve the signal-to-noise ratio.

  The tone burst sound generated by the sound stimulator 183 is input to the left ear through the air tube 182 and the adapter 181. Although not shown in FIG. 20, measurement is performed so that white noise is always given to the right ear and there is no influence from the sound from the outside. The brain magnetic field is measured by a magnetic field sensor in the dewar 3. The magnetic field sensor is driven by the FLL circuit 8, and the output of the FLL circuit 8 is collected and recorded as digital data in the data recording / analyzing apparatus 10 through the amplifier filter circuit 9. A screen for controlling the data recording / analyzing apparatus 10, the FLL circuit 8, the amplifier filter circuit 9 and the like, a screen for displaying the data analysis result, and the like are displayed on the display 11. Components other than the bed 4 and the dewar 3 shown in FIG. 20 are desirably arranged outside the magnetic field shield room 1 shown in FIG.

  FIG. 21 is a diagram for explaining the positional relationship between the arrangement of the magnetic field sensor and the human head in the sixth embodiment of the present invention. FIG. 21 shows the measurement range (175 mm × 175 mm) of the cerebral magnetic field by the measurement point 30 where the magnetic field sensor is arranged. The measurement range when measuring the cerebral magnetic field from the left side of the subject 2 is shown at the top, and the measurement range when measuring the cerebral magnetic field from the right side at the bottom is shown. In FIG. 21, since the auditory-induced brain magnetic field is measured, a measurement point 30 is also arranged slightly above the ear.

  FIG. 22 is a flowchart for explaining the procedure for measuring the cerebral magnetic field in the sixth embodiment of the present invention. First, in order to measure the cerebral magnetic field from the left side of the head, the head of the subject 2 and the dewar 3 are aligned, first the right ear stimulation (contralateral sound stimulation) is performed for 8 minutes, and then left Ear stimulation (ipsilateral sound stimulation) is performed for 8 minutes. Subsequently, in order to measure the cerebral magnetic field from the right temporal region, the subject 2 lies on the bed 2 with the left shoulder down and performs alignment. After the alignment, the left ear stimulation (opposite sound stimulation) is performed for 8 minutes, and the right ear stimulation (ipsilateral sound stimulation) is continuously performed for 8 minutes.

  FIG. 23 is a diagram for explaining a display example of the measurement result of the cerebral magnetic field of a healthy person and the principle of extracting the maximum vector in the sixth embodiment of the present invention. 23 shows an example of the measurement result of the cerebral magnetic field when the left ear is stimulated, and the bottom of FIG. 23 shows the measurement result of the cerebral magnetic field when the right ear is stimulated. The measured cerebral magnetic field waveforms 212 and 214 are obtained by superposing the measured cerebral magnetic field waveforms of all 64 channels subjected to baseline correction in the time zone before the sound stimulation after 70 times of addition processing. it's shown.

The current arrow maps 211 and 213 respectively indicate current arrow maps at times (peaks called N100m) at which the maximum peaks of the measured brain magnetic field waveforms 212 and 214 appear. Current (intensity of contralateral side stimulus) intensity Icontralateral from the maximum current arrow in arrow map 211 (hereinafter, abbreviated as I _c) and calculates the inclination θ1 of the maximum current arrow. Similarly, an intensity I ipsilateral (intensity of ipsilateral stimulation) (hereinafter abbreviated as I _i ) and a gradient θ 2 of the maximum current arrow are calculated from the maximum current arrow in the current arrow map 213. Calculation is performed to obtain the intensity ratio I _i / I _c (intensity of the ipsilateral stimulus / intensity of the contralateral stimulus) and the phase difference | Δθ | = | θ1−θ2 |. When measuring the cerebral magnetic field from the right temporal region, I _c (intensity of contralateral stimulation) uses the maximum current arrow at the peak of the cerebral magnetic field waveform by left ear stimulation, and I _i (ipsilateral stimulation) For intensity, the maximum current arrow at the peak of the waveform of the cerebral magnetic field due to right ear stimulation is used.

FIG. 24 is a diagram showing an example of the result of the intensity ratio I _i / I _c (intensity of ipsilateral stimulation / intensity of contralateral stimulation) obtained in the sixth embodiment of the present invention. It is.

  FIG. 25 is a diagram showing a result example of the phase difference | Δθ | obtained in the sixth embodiment of the present invention.

  FIG. 26 is a diagram showing a result example in which the time (latency) when N100m obtained in the sixth embodiment of the present invention appears is summarized for each temporal region.

  The analysis results for 4 healthy subjects, 5 right hemisphere infarction patients, 2 patients with chronic dizziness, and 2 patients with moyamoya disease in which disturbances in cerebral blood flow were observed will be described with reference to FIGS. . However, in 2 out of 5 patients with right hemisphere infarction, the magnetoencephalogram was not detected in the right temporal region because the infarct range was wide.

  As shown in FIG. 24, it can be understood that the current ratio is smaller than 1 in both sides of a healthy person, and the current arrow strength on the opposite side is strong. On the other hand, in one case of right hemisphere infarction (right cerebral infarction) and one patient with chronic vertigo, it can be seen that there are cases where the current ratio is greater than one. Two patients with moyamoya disease had a current ratio of 1 or less, which was the same as that of healthy subjects.

  As shown in FIG. 25, it can be seen that the phase difference of both sides of a healthy person is 20 degrees or less, and the directions of the maximum vectors are in good agreement. On the other hand, a phase difference of over 20 degrees was observed in 3 out of 6 right-sided cerebral infarction patients, and the phase difference was significantly different from the other cases in 1 chronic vertigo patient and 1 moyamoya disease patient. It was.

  As shown in FIG. 26, the latency of contralateral sound stimulation (stimulation of the left ear) is significantly shorter in the right side of a healthy subject, but in the left side of the head, significance is particularly recognized in any case. Absent. In the left temporal region of right hemisphere infarction, the latency was prolonged in 3 out of 6 cases due to ipsilateral sound stimulation (stimulation of the left ear) in comparison with healthy subjects. In the right temporal region of right hemisphere infarction, the contralateral sound stimulation (left ear stimulation) tended to be longer than in healthy subjects, and even in the ipsilateral sound stimulation (right ear stimulation), It was found that one of the three cases was extended.

  In patients with chronic dizziness, one out of two cases showed a prolonged left temporal latency. On the other hand, in patients with moyamoya disease, there was no significant difference in the latency of both sides from healthy subjects.

Although detailed explanation is omitted, a synchronization signal synchronized with the start of application of a stimulus signal such as light and sound applied to a living body is collected as a pair with a brain magnetic field signal, and a brain magnetic field measured from a plurality of directions. The time axis is converted, that is, the time axis is translated so that the time axis of the waveform has a common origin (t = 0) when the synchronization signal is collected. Next, similarly to the first to fourth embodiments, the vector intensity I (x, y, t) and its phase θ (x, y, t) are obtained, and the time-intensity plot of the maximum vector is obtained. (T-I _max ) and time-phase plot (t-θ), or time-phase / intensity plot (t-θ · I) for all channels can be obtained and displayed.

  In each of the embodiments of the present invention described above, the vector intensity and the phase obtained from the measured magnetic field waveform of the cardiac magnetic field or the brain magnetic field are used. Without analyzing the biological phenomena using a large number of figures (maps) that represent the state of aging, using a much smaller figure (map) than the number used in the prior art, The time change of electrophysiological excitement can be grasped in detail.

The perspective view explaining schematic structure of the biomagnetic field measuring device of the 1st example of the present invention. The perspective view explaining arrangement | positioning of the magnetic field sensor in 1st Example of this invention. The perspective view explaining the structure of the magnetic field sensor which detects the normal line component of the biomagnetic field in 1st Example of this invention. The figure explaining the positional relationship with arrangement | positioning of the magnetic field sensor in the 1st Example of this invention, and the front of a human body, and the back. The perspective view explaining the method of aligning arrangement | positioning of the magnetic field sensor in 1st Example of this invention, and the position with the chest of a human body. The figure explaining the flow of the measurement of the biomagnetic field in the 1st Example of this invention, and the analysis of the measured signal. The figure which shows the example of the electrocardiogram waveform measured simultaneously with the measurement of the electrocardiogram waveform measured from the front and the back, and the electrocardiogram waveform in the first embodiment of the present invention with the healthy subject as the subject. In the 1st Example of this invention, the current arrow figure in the time after 30 ms progress from the starting point of QRS wave of the healthy person's cardiac magnetic field waveform measured from the front, and the figure which shows the maximum current vector. The figure which shows the reference | standard of the phase of the largest vector in 1st Example of this invention. In the first embodiment of the present invention, the time-intensity plot (t-I _max x) in the time zone from the start point of the QRS wave of the cardiac magnetic field waveform of the healthy subject measured from the front and back to 200 ms. ) And a display example of a time-phase plot (t-θ). In the first embodiment of the present invention, the time-intensity plot (t-) in the time zone from the start point of the QRS wave of the magnetocardiogram waveform of the right leg block patient measured from the front and back to 200 ms. The figure which shows the example of a display of Imax) and a time-phase plot (t-theta). Flow of measurement of biomagnetic field and analysis of measured signal when performing time-phase / intensity plot of vector at each time of all 64 channels in the second embodiment of the present invention. Illustration to explain. In the second embodiment of the present invention, the time-phase intensity plot of the vectors of all 64 channels in the time zone from the QRS start point of the cardiac magnetic field waveform measured from the front of the healthy subject to 200 ms is shown. The figure which shows the example of a display. In the second embodiment of the present invention, the time-phase intensity plot of the vectors of all 64 channels in the time zone from the QRS start point of the cardiac magnetic field waveform measured from the back of the healthy subject to 200 ms is shown. The figure which shows the example of a display. In the second embodiment of the present invention, the time of the vectors of all 64 channels in the time zone from the start of the QRS wave of the magnetocardiogram waveform of the right leg block patient measured from the front to 200 ms− The figure which shows the example of a display of a phase intensity plot. In the second embodiment of the present invention, the time of the vectors of all the channels of 64 channels in the time zone from the start point of the QRS wave of the magnetocardiogram waveform of the right leg block patient measured from the back to 200 ms− The figure which shows the example of a display of a phase intensity plot. Third tangential components B _x biomagnetic field to be employed in the _embodiment, and a schematic diagram for explaining the structural example of the magnetic field sensor for detecting the B _y component of the present invention. The figure which shows the example of the differential coil which has the shape of a circle as a whole coil used in the 4th Example of this invention. The figure explaining the outline of the structural example of the biomagnetic field measuring apparatus which performs a cardiac magnetic field measurement simultaneously from the direction of the front and back used in the 5th Example of this invention. The perspective view explaining the structural example of the biomagnetic field measuring apparatus which measures the cerebral magnetic field induced in auditory in the 6th Example of this invention. The figure explaining the positional relationship of arrangement | positioning of the magnetic field sensor and head of a human body in the 6th Example of this invention. The flowchart explaining the procedure of the measurement of the brain magnetic field in the 6th Example of this invention. The figure explaining the display example of the measurement result of a cerebral magnetic field of a healthy subject, and the principle which extracts a maximum vector in the 6th Example of this invention. 6 illustrates an example of a result of the intensity ratio I _{i /} I c of the maximum current vector obtained in the practice example _(intensity of the intensity / contralateral side stimulation of ipsilateral stimulus) of the present invention. The figure which shows the example of a result of phase difference | (DELTA) (theta) | obtained in the 6th Example of this invention. The figure which shows the example of a result which put together the time (latency) when N100m obtained in the 6th Example of this invention appeared for every temporal region.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Magnetic field shield room, 2 ... Subject, 3 ... Dewar, 3'-1 ... Upper dewar, 3'-2 ... Lower dewar, 4, 4 '... Bed, 5, 5' ... Gantry, 6 ... Electrocardiograph Electrode, 7 ... Electrocardiograph, 8 ... FLL circuit, 9 ... Amplifier filter circuit, 10 ... Data recording analysis device, 11 ... Display (display device), 12 ... Rail, 13 ... Pulley, 20, 20-i (i = 11, 12, ..., 18; i = 21, 22, ..., 28; i = 31, 32, ..., 38; i = 41, 42, ..., 48; i = 51, 52, ..., 58; = 61, 62, ..., 68; i = 71, 72, ..., 78; i = 81, 82, ..., 88), 20 ', 20 "... magnetic field sensors, 21, 21-1', 21-2 ' 21 "... SQUID, 22, 22'-1, 22'-2 ... detection coil, 23, 23'-1, 23'-2 ... reference coil, 30 ... total Point, 31, 31 '... measurement reference point, 40 ... subject reference point, 41 ... x-direction laser light source, 42 ... y-direction laser light source, 43 ... x-axis line forming beam, 44 ... y-axis line forming beam , 45 ... xz mark (mark), 46 ... yz mark (mark), 49 ... crossing line, 50 ... differential coil, 181 ... adapter, 182 ... air tube, 183 ... sound stimulator, 184 ... synchronization signal, 211, 213 ... Current arrow map, 212, 214 ... Measured brain magnetic field waveform.

Claims (7)

A plurality of SQUID magnetometers for measuring a biomagnetic field generated from a living body;
A biological signal measuring device for measuring and collecting biological signals generated periodically other than the biomagnetic field;
An arithmetic processing unit that performs arithmetic processing of the measured biomagnetic field signal and the biomedical signal;
A display device for displaying the result of the arithmetic processing;
Performing the measurement of the biomagnetic field and the biosignal simultaneously from a plurality of directions;
The arithmetic processing unit is:
Using the biological signal measured in the plurality of directions as a time variable, the time axis is converted so that the biomagnetic field signal measured in the plurality of directions has a common origin (t = 0). ,
Performing the same transformation as the transformation on the time axis of the waveform of the biomagnetic signal measured simultaneously with the biosignal,
The direction perpendicular to the surface that contacts the surface of the living body is the z direction, and the direction that is orthogonal to the z direction and that is horizontal to the surface that contacts the surface of the living body is the x direction and y direction, and has the common origin (t = 0) Using the biomagnetic field signal, obtain the magnitude of the two-dimensional magnetic field vector and / or the angle representing the direction in the xy plane at each measurement point (x, y) of the biomagnetic field,
Among the two-dimensional magnetic field vectors at the plurality of measurement points (x, y), an angle representing the maximum magnitude of the two-dimensional magnetic field vector and / or the direction on the xy plane is defined as the common origin (t = 0). At each point on the time axis with
The biomagnetic field measurement , wherein the display device displays the maximum magnitude of the two-dimensional magnetic field vector and / or the time change of the angle in each of the plurality of directions in which the biomagnetic field is measured. apparatus.   2. The biomagnetic field measurement apparatus according to claim 1, wherein the time change of the maximum two-dimensional magnetic field vector and / or the angle is the same for each direction in which the biomagnetic field is measured. A biomagnetic field measurement apparatus characterized by being displayed using the time axis.   2. The biomagnetic field measurement apparatus according to claim 1, wherein a time change in the magnitude and / or angle of the maximum two-dimensional magnetic field vector is different in each direction in which the biomagnetic field is measured. A biomagnetic field measuring apparatus which is displayed in color and using the same time axis.   A plurality of SQUID magnetometers for measuring a biomagnetic field generated from the heart of a living body, a biosignal measuring device for measuring any one of an electrocardiogram waveform, a heart waveform, and a pulse waveform as a biosignal, and the measured biomagnetic field A signal processing unit that performs arithmetic processing on the signal and the biological signal, and a display device that displays a result of the arithmetic processing, and performing the measurement of the biomagnetic field and the measurement of the biological signal simultaneously. The calculation processing device is operated in two directions, ie, a surface and a back surface. The arithmetic processing unit is configured such that the direction perpendicular to the surface in contact with the surface of the living body is the z direction, and the direction perpendicular to the z direction and horizontal to the surface in contact with the surface of the living body And the y direction, the time variable t, and the time axis of the waveform of the biological signal measured from the two directions has a common origin (t = 0), the biological signal measured from the two directions. Waveform time axis Performing the same transformation as the transformation on the time axis of the waveform of the biomagnetic field signal measured simultaneously with the biomedical signal, and the common origin (t = 0), a two-dimensional magnetic field vector at each measurement point (x, y) of the biomagnetic field is obtained from the signal of the biomagnetic field having 0), and the two-dimensional magnetic field at a plurality of measurement points (x, y). An angle representing the magnitude of the maximum two-dimensional magnetic field vector and / or the direction on the xy plane among the vectors is obtained at each point on the time axis with the common origin (t = 0) as the origin, and the display device The biomagnetic field measurement apparatus, wherein the time change of the maximum magnitude and / or angle of the maximum two-dimensional magnetic field vector is displayed in the two directions in which the biomagnetic field is measured.   5. The biomagnetic field measurement apparatus according to claim 4, wherein a direction in which the angle is 0 ° is a left horizontal direction perpendicular to the body axis of the living body, the angle is in a range of 0 ° to 180 °, and 0 A biomagnetic field measuring apparatus, characterized in that it is displayed in the range of ° to -180 °.   5. The biomagnetic field measurement apparatus according to claim 4, wherein information on the leg block conduction disorder of the heart is detected.   A plurality of SQUID magnetometers that measure a biomagnetic field generated from the head of the living body, a signal that stimulates the living body, and a stimulation device that generates a synchronization signal synchronized with the start of generation of the stimulating signal, and the measured An arithmetic processing unit that performs arithmetic processing of a biomagnetic field signal and the synchronization signal; and a display device that displays a result of the arithmetic processing; and measurement of the synchronization signal from each of a plurality of directions of the head of the living body The bio-magnetic field is measured, and the arithmetic processing unit is configured such that the direction perpendicular to the surface in contact with the surface of the living body is the z direction, the direction perpendicular to the z direction and horizontal to the surface in contact with the surface of the living body is the x direction, and The synchronization measured in each of the plurality of directions so that the time axis of the biomagnetic field waveform measured from the plurality of directions has a common origin (t = 0), where y is the time variable and t is the time variable. Signal to the common source (T = 0) The time axis of the waveform of the biomagnetic field measured from the plurality of directions is converted, and the living body having the common origin (t = 0) in the plurality of directions in which the biomagnetic field is measured. A two-dimensional magnetic field vector at each measurement point (x, y) of the biomagnetic field is obtained from the magnetic field signal, and the maximum 2 of the two-dimensional magnetic field vectors at the plurality of measurement points (x, y). An angle representing the magnitude of the dimensional magnetic field vector and / or the direction on the xy plane is obtained at each point on the time axis with the common origin (t = 0) as the origin, and the maximum two-dimensional A biomagnetic field measurement apparatus, wherein a time change of the magnitude and / or angle of a magnetic field vector is displayed for the plurality of directions in which the biomagnetic field is measured.

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