JP3094988B2 - Biomagnetic field measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SQUID (SQUID) for measuring a magnetic field generated from the heart of an adult, a child, a fetus, or the like.
upperconducting Quantum In
In particular, the present invention relates to a biomagnetic field measurement apparatus using a magnetometer, in which an ultrasonic probe is arranged in a shield room, and an ultrasonic tomographic image of a subject and a waveform of a magnetic field emitted from the heart of the subject are displayed in the shield room. The present invention relates to a monitor device displayed in a room and a control for starting measurement of a biomagnetic field from inside a shield room.

[0002]

2. Description of the Related Art Ultrasonography is widely used for the diagnosis of fetal heart disease, but it is possible to grasp the shape and rough movement of the heart and the state of blood flow, but to fine movement of the heart muscle. Cannot be detected.

[0003] In the conventional biomagnetic field measurement, a waveform monitor is arranged outside a shield room, and an operator is required to
The waveform could not be confirmed inside the shield room. In particular, when detecting a magnetic field emanating from a fetal heart in which the position of the heart is not constant, the operator hears information from a person operating a monitor device outside the shielded room,
The measurement location had to be determined (Rev. Sc
i. Instrum. 66 (10) pp. 5085-
5091 (1995)).

Using a biomagnetic field measuring device, a magnetic field generated from the heart (hereinafter abbreviated as a cardiac magnetic field) can be measured to diagnose myocardial activity. On the other hand, the ultrasonic diagnostic apparatus can diagnose the state of blood flow in the heart and the like.

[0005]

The conventional biomagnetic field measurement has a problem that it takes a long time to search for a measurement place, and it is difficult to measure a magnetic field at an optimum place. Furthermore,
Since the control device for the SQUID magnetometer and the control device for capturing the magnetic field waveform were also located outside the shield room,
There was a problem that the magnetic field waveform could not be recorded in the most optimal time zone.

In order to accurately determine a heart disease, it is necessary to make a comprehensive diagnosis by collating a measurement result of a cardiac magnetic field obtained at about the same time with a result of an ultrasonic diagnostic apparatus. However, if a conventional ultrasonic diagnostic device that uses a lot of magnetic materials is placed inside a shield room, magnetic noise is generated. In this case, there is a problem that the measurement by the ultrasonic diagnostic apparatus cannot be performed simultaneously with the measurement of the cardiac magnetic field.

In the measurement of a very weak magnetic field generated from a fetal heart, the sensor of the biomagnetic field measuring device must be as close as possible to the fetal heart. However, just before measuring the magnetic field generated from the fetal heart because the fetus moves in the uterus, it is desirable to confirm the position of the fetal heart with an ultrasonic diagnostic apparatus capable of non-invasive diagnosis, It has been strongly desired to use an ultrasonic diagnostic apparatus in a shielded room.

An object of the present invention is to enable observation of a magnetic field waveform measured from a subject's heart in a shielded room, a magnetic field distribution and a current distribution obtained by arithmetic processing, and control of measurement start of a magnetic field waveform. Another object of the present invention is to provide a biomagnetic field measurement apparatus that can quickly adjust a sensor to an optimum measurement place.

Another object of the present invention is to provide an apparatus for measuring a biomagnetic field together with an ultrasonic inspection in a shield room.

[0010]

According to the biomagnetic field measuring apparatus of the present invention, there is provided a display for monitoring a magnetic field waveform emitted from a fetal heart inside a subject, a magnetic field distribution in the heart, and a current distribution in a shielded room. A means for moving a bed, a means for moving a gantry holding a cryostat, comprising: a speaker for emitting sound in synchronization with the heartbeat of a heart; a SQUID magnetometer; and a switch for controlling the capture of a magnetic field waveform. And an air mat for raising or lowering a part of the subject's body on the bed.

According to the biomagnetic field measuring apparatus of the present invention, the operator inside the shield can observe the magnetic field waveform generated from the heart of the fetus inside the subject in real time on the display screen of the display, and can find the optimum measurement position. Sensors can be quickly adjusted.

In the apparatus of the present invention, an ultrasonic probe of an ultrasonic diagnostic apparatus is disposed in a shield room, and a transmitting circuit for transmitting ultrasonic waves, and a processing for receiving ultrasonic waves and processing received signals. A main body of the ultrasonic diagnostic apparatus including a processing circuit to be performed is disposed outside the shield room, and an ultrasonic tomographic image is displayed on the display disposed in the shield room.

According to the configuration of the present invention, the measurement result of the biomagnetic field and the ultrasonic tomographic image of the fetus inside the subject can be confirmed in the shielded room, the magnetic field generated from the fetal heart is measured. The operator in the shielded room can observe the position of the fetal heart almost in real time using an ultrasonic tomographic image, so the SQUID
The position of the magnetometer can be quickly adjusted, and the magnetic field generated from the fetal heart can be detected with high sensitivity and sharpness. When measuring the magnetic field generated from the heart of an adult or a child, the cardiac magnetic field can be measured while simultaneously observing the blood flow state in the heart with an ultrasonic tomographic image.

According to the biomagnetic field measuring apparatus of the present invention, it is possible to detect abnormalities in the heart of a fetus such as arrhythmia, to make early diagnosis of heart disease, and to obtain important information for intrauterine treatment and postnatal treatment. it can.

As shown in FIGS. 1 and 7, the biomagnetic field measuring apparatus of the present invention comprises a shield room 1, a bed 4, a SQUID magnetometer for detecting a magnetic field from a subject, and a SQUID magnetometer.
A cryostat 2 for holding the D magnetometer at a very low temperature (liquid helium He temperature or liquid nitrogen temperature), a gantry 180 for holding the cryostat, and a drive detection for driving the SQUID magnetometer and detecting a signal from the SQUID magnetometer A computer 90 that collects the output of the circuit 50 and performs an arithmetic process, and includes a measured magnetic field waveform, a measured electrocardiogram waveform, a distribution of a magnetic field obtained by the arithmetic process, and an arithmetic process in the shield room 1. Means for displaying one or more of the distributions of the measured currents (the monitor display 8).
0), a SQUID magnetometer operation button 19a for controlling the operation of the SQUID magnetometer, a data collection start button 19b for controlling the start of data collection, and a speaker 100 for generating a beep sound in synchronization with the heartbeat of the mother and the fetus. And
Outside the shield room, an amplifier filter unit 60 and a means (heart rate detection unit) 11 for detecting a heart rate and a heart rate from a measured magnetic field waveform are arranged.

In order to detect a magnetic field generated from a fetal heart, for example, 4 to 1
SQUID for detecting normal components (z components) of six magnetic fields
The magnetometers are arranged in a matrix of 2 × 2 to 4 × 4. A magnetic field distribution diagram and a current distribution diagram in a fetal heart can be obtained from magnetic field waveforms obtained from detection signals from a plurality of SQUID magnetometers. Further, when detailed information is required, SQUID magnetometers for detecting three components (x, y, z components) of the magnetic field may be arranged in a matrix.

Inside the shield room 1, an ultrasonic probe 8 is arranged. Outside the shield room 1, a transmission circuit for transmitting ultrasonic waves to the subject, and ultrasonic waves reflected from the subject are provided. And a processing circuit for performing reception signal processing and receiving signal processing. The ultrasonic tomographic image processed by the main body 6 is displayed on the monitor display 80 described above. When the components of the main body 6 are made of a non-magnetic material, the magnetic field generation from the main body 6 is shielded sufficiently small so as not to interfere with the detection of the magnetic field generated from the subject. The main unit 6 can be arranged at a position inside the shield room 1 away from the cryostat 2 in which the magnetometer is built.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a biomagnetic field measuring apparatus according to an embodiment of the present invention. As shown in FIG. 1, a cryostat 2 for holding a SQUID magnetometer at an extremely low temperature, a gantry 180 for holding a cryostat 2, a bed 4 on which a subject lies, and a SQ
A SQUID magnetometer operation button 19a for controlling the operation of the UID magnetometer, a data collection start button 19b for controlling the start of data collection, a monitor display 80 for displaying an output waveform of the SQUID magnetometer, a maternal and fetal A speaker 100 that generates a beep sound in synchronization with the heartbeat (heartbeat) of the heart is arranged. The SQUID magnetometer operation button 19a and the data collection start button 19b are placed at positions away from the SQUID magnetometer in order to avoid generation of magnetic field noise. It is desirable that the buttons 19a and 19b generate little current, such as a switch by infrared rays.
The monitor display 80 is desirably a monitor device that generates less magnetic field, such as a liquid crystal display, a plasma display, and a display by projection.

Outside the shield room, a drive detection circuit 50 for driving the SQUID magnetometer and detecting a magnetic signal from the SQUID magnetometer, and an amplifier filter unit 60 for applying an amplifier or filter to the output of the drive detection circuit 50
And a computer 90 for recording the output of the amplifier filter 60 as digital data, and a heart rate detection unit 11 for detecting the heart rate and heart rate of the heart from the measured magnetic field waveform. Heart rate detection unit 11
Is a narrow band (10 Hz) magnetic field signal generated from the heart, for example.
(20 Hz or the like) and a circuit for performing peak detection by applying a band-pass filter. However, similar heartbeat detection may be performed by software.

FIG. 2 is a diagram showing a configuration of a biomagnetic device in a shield room according to an embodiment of the present invention. When the four wheels 305 at the bottom of the bed slide on rails 295 arranged on the floor of the shield room, the entire bed can move in the direction A (bed short axis direction). The movement of the bed in the B direction (vertical direction) can be finely adjusted by a vertical movement lever 285 linked to a hydraulic cylinder. The movement of the bed in the direction C (bed long axis direction) can be finely adjusted by sliding the bed top plate 315. The gantry 180 holding the cryostat 2 moves the cryostat 2 in the direction D (in the xz plane) and in the direction E (yz).
(In-plane). Further, an air mat 245 for raising a part of the subject's body to bring the heart (adult's heart or fetus) closer to the lower end of the cryostat 2 is arranged on the bed. A of bed 4
The movement in the B and C directions, the movement in the D and E directions of the gantry 180, and the vertical movement of the air mat 245 can be controlled manually or by the remote control lever 19c.

The procedure for measuring the biomagnetic field in the apparatus shown in FIGS. 1 and 2 will be described below. The subject lies on the bed 4, and the operator in the shield room 1 moves the bed 4 up and down, left and right, and back and forth (A, B and C directions) manually or by a remote control lever 19 c, and incorporates a SQUID magnetometer. The cryostat 2 is aligned with the patient's heart. The gantry 180 is rotated in the D and E directions as needed to maintain the subject's heart and the position of the cryostat 2 in an optimal positional relationship. The position between the subject's heart and the cryostat 2 is 20
cm, the operator will use the SQUI
By pressing the D magnetometer operation button 19a, the SQUID magnetometer is operated. The operator performs the final fine adjustment while watching the output waveform from the SQUID magnetometer on the monitor display 80 and listening to the beep sound generated from the speaker 100 and accompanying the heartbeat of the subject. After the fine adjustment is finished, the operator
While viewing the magnetic field waveform of 0, the user presses the data collection start button 19b at the time when the
Record the magnetic field waveform to The above is a general operation procedure.

FIG. 3 is a diagram showing a configuration of magnetic field measurement for detecting a magnetic field generated from a fetal heart according to an embodiment of the present invention. Magnetic field generated from maternal heart 130 and fetal heart 1
In order to distinguish the magnetic field from the magnetic field generated from 40, the measurement of the maternal electrocardiogram by the limb lead electrocardiograph 120 is performed simultaneously with the measurement of the magnetic field by the SQUID magnetometer inside the cryostat 2. The monitor display 80 simultaneously displays maternal electrocardiogram information and fetal electrocardiogram information obtained by the SQUID magnetometer in the cryostat 2. The operator can move either the bed 4 or the cryostat 2 to search for the location of the fetal heart while watching the fetal heart's magnetic field waveform and listening to the beep associated with the fetal heart's heartbeat. Becomes Thus, the lower portion of the cryostat 2 is brought into close contact with the abdominal surface of the mother (FIG. 11).
), The optimal position for detecting the magnetic field of the fetal heart can be selected. In addition, as a filter constituting the amplifier filter unit 60, noise caused by abdominal movement due to maternal respiration (2-3 Hz abdominal movement gives vibration to the cryostat, and this vibration is transmitted to the SQUID magnetometer. Therefore, in order to eliminate noise, the frequency component of 2 to 3 Hz of the output signal of the drive detection circuit 50 is cut off and a signal having a predetermined frequency band (4 to 5 Hz or more) is passed. Use an analog or digital filter.

FIG. 4 is a view showing an example of a screen showing the result of the measurement of the magnetic field emitted from the fetal heart, and is a screen displayed on the monitor display 80 when the magnetic field emitted from the fetal heart shown in FIG. 3 is detected. FIG. As shown in the upper part of the screen, channels 0, 1, 2,
The magnetic field waveforms 15-1, 15-2, 15-3, and 15-4 emitted from the fetal heart detected in step 3, respectively, are swept in real time from left to right on the screen and drawn. As shown in the lower part of the screen, a maternal electrocardiogram (ECG) 205 is simultaneously swept and drawn. The operator operates upper waveforms 15-1, 15-2, 15-3,
Since the position of the peak of 15-4 does not coincide with the position of the peak of the lower waveform 205, it is confirmed that the magnetic field generated from the fetal heart is detected.

The screen shows the upper waveforms 15-1, 15-2,
The heart rate of the fetus which displays the heart rate detected from 15-3 and 15-4 as a numerical value (heart rate = 14 in FIGS. 4 and 5)
2), a portion 175 for displaying the fetal heartbeat, a fetal heartbeat synchronization flashing light 165 that flashes in synchronization with the fetal heartbeat to notify the timing of the fetal heartbeat, and a maternal electrocardiogram 205 obtained from the maternal electrocardiogram 205 at the bottom of the screen. A portion 195 for displaying the heart rate of the mother (heart rate = 70 in FIGS. 4 and 5) for displaying the heart rate numerically, and the heartbeat of the mother for notifying the timing of the heartbeat of the heart 130 of the mother. A maternal heart rate synchronization flashing light 185 flashing in synchronization is displayed. The maternal heart rate can be measured using the limb lead electrocardiograph 120 or the maternal heart 130.
May be extracted from the magnetic field waveform emanating from.

At the same time as the fetal heartbeat synchronous flashing light 165 for notifying the timing of the fetal heartbeat blinks, a beep sound is generated from the speaker 100 in accordance with the fetal heartbeat. If necessary, a beep corresponding to the heartbeat of the mother's heart 130 is also generated. The operator can detect the magnetic field signal emitted from the fetal heart by referring to the beep sound synchronized with the heartbeat of the fetus emitted from the speaker 100, the heartbeat synchronization blinking light 165 of the fetus, the magnetic field waveform 15 emitted from the heart of the fetus, and the like. The cryostat 2 having a built-in SQUID magnetometer can be quickly fitted on the abdomen of a pregnant woman.

FIG. 5 is a diagram showing another example of a screen showing the result of the measurement of the magnetic field generated from the fetal heart, which is displayed on the monitor display 80 when the magnetic field generated from the fetal heart shown in FIG. 3 is detected. FIG. 7 is a diagram showing a screen displayed. The monitor display 80 shows the magnetic field distribution diagram 21 in the fetal heart.
5 and the current distribution diagram 225 in the fetal heart, the magnetic field waveforms 15-1, 15-2, 15-
3, 15-4, and the waveform of the maternal electrocardiogram 205 are simultaneously displayed in real time.

The magnetic field distribution diagram 215 shows a plurality of SQUIDs.
The distribution of the normal magnetic field component (B _z component) measured by the magnetometer, and the measured tangential magnetic field component (B _x ,
B _y ), the absolute value ( ² (B _x ² + B _y ² )) of the measured magnetic field component in the normal direction (dB _z / dx, dB _z / dy)
(絶 対 ((dB _z / dx) ² + (dB _z / d
y) It is displayed using one of ² )).

In the example shown in FIG. 5, the absolute value (√) of the differential value (dB _z / dx, dB _z / dy) of the magnetic field component (B _z component) in the normal direction measured by nine SQUID magnetometers.
Shows the ^{_{((dB z / dx) 2}} + (dB z / dy) 2)) magnetogram 215 obtained from.

The current distribution diagram 225 shows the vector values of the measured tangential magnetic field components (B _x , B _y ) as 9 counterclockwise.
0 degree turn was either direction indicates the direction of the vector value turned 90 degrees counterclockwise of a differential value of the magnetic field component of the measured normal direction _{(dB z / dx, dB z} / dy).

The screen shown in FIG. 5 is similar to FIG. 4, and includes a fetal heart-beat synchronous flashing light 165, a part 175 for displaying the fetal heart-rate, a maternal heart-rate synchronous blinking light 185, and a maternal heart-rate. (Heart rate = 70 in FIGS. 4 and 5).

The displayed distribution map is obtained by detecting the peak value of the magnetic field signal emitted from the fetal heart by the heart rate detecting unit 11 and displaying the distribution of the magnetic field and the current by the time phase indicated by the line 235 representing the time when the distribution map is displayed. Is the distribution of the magnetic field and the current in. The magnetic field distribution diagram 215 and the current distribution diagram 225 may be displayed for every heartbeat, or may be displayed once every few heartbeats. The operator uses the magnetic field distribution map 21
5 or moving the bed 4 or the gantry 180 while determining the current distribution diagram 225 and the magnetic field waveform 15 generated from the fetal heart to determine the location and observation range of the strongest magnetic field generated from the fetal heart Becomes possible.

The vertical direction of the display screen of the magnetic field distribution diagram 215 or the current distribution diagram 225 corresponds to a sensor position obtained when the operator looks at the mother from the cryostat 2 above the bed 4 so that the operator can see which part of the mother's body. It is possible to judge whether the magnetic field generated from the heart of the fetus is strong, and to easily understand the position of the fetus in the mother.

FIG. 6 is a structural view of the air mat 245 arranged between the lower abdomen near the pregnant woman where the fetal heart 140 of FIG. FIG. 6 shows a state in which the air is maximally filled from the air input unit 275 into the air mat 245. To prevent a pregnant woman from falling sideways and dropping from the air mat 245, guides 255 for preventing falling are provided on both sides of the flat portion 265. The pregnant woman lies on her back on the bed 4 or lays on her side so that the lower abdomen is positioned on the deflated air mat 245.

Thereafter, the operator operates the air input unit 27.
From step 5, air is put into the air mat 245 using a pump or the like, and the lower abdomen of the pregnant woman is raised. By raising only the lower abdomen of the pregnant woman, the cryostat 2 can be moved away from the mother's heart 130, so that only the magnetic field signal from the fetal heart can be easily separated. Adjustment of the input of air in the air mat 245 can also be performed by the remote control lever 19c.

FIG. 7 shows another example of the configuration of the biomagnetic field measuring apparatus according to the embodiment of the present invention. In the apparatus having the configuration shown in FIG. 1, an ultrasonic tomographic image can be observed inside a shield room. FIG. 3 is a diagram illustrating a configuration. In the description relating to FIG.
Description common to FIG. 1 is omitted. As shown in FIG. 7, inside a shield room 1, an ultrasonic probe (ultrasonic probe) 8 for performing an ultrasonic inspection on a bed 4 on which a subject (not shown) lies, Monitor display 80 for displaying the obtained ultrasonic tomographic image by receiving the reflected ultrasonic wave by the ultrasonic probe 8 and performing signal processing, gain, focus, various photographing modes (measurement modes) of the ultrasonic diagnostic apparatus, etc. Is set. Various shooting modes (measurement modes) include an A mode, a B mode, an M mode, a Doppler mode, and a CFM mode, which will be described later.

Outside the shield room 1, a measuring circuit of an ultrasonic diagnostic apparatus (a transmitting circuit for transmitting ultrasonic waves and a processing circuit for receiving ultrasonic waves and processing received signals)
And the like, and an ultrasonic diagnostic apparatus main body 6 containing therein.
The ultrasonic diagnostic apparatus body 6 includes an ultrasonic probe 8, a monitor display 80, and a controller 1 inside the shield room 1.
10 and constitutes the entire ultrasonic diagnostic apparatus.

Next, an example of a procedure for measuring a weak magnetic field generated from the fetal heart by the apparatus of the present invention will be described. Although not described in the description of FIG. 1, the bed 4 moves in the short axis of the bed (A direction, x direction), moves in the long axis of the bed (C direction, y direction), and moves the bed up and down. Direction (B direction,
The cryostat 2 can be moved in the D direction (in the xz plane) and the E direction (y direction) by the gantry 180.
(in the z-plane). The subject lies on the bed 4 pulled out from under the cryostat 2 in the A direction (x direction). The operator applies the ultrasonic probe 8 to the abdomen of the subject, confirms the position of the heart of the fetus while watching the ultrasonic image (for example, a B-mode image) on the monitor display 80, and places the lower surface of the cryostat 2 at the confirmed position as much as possible. A, B,
By adjusting the amount of movement in the direction C and the amount of tilt of the gantry 180 in the directions D and E, the cryostat 2 can be adjusted to an optimum position and the fetal heart magnetic field can be measured.

FIG. 8 is a diagram showing the overall configuration of an ultrasonic diagnostic apparatus used in the biomagnetic field measuring apparatus according to the embodiment of the present invention. An ultrasonic probe (ultrasonic probe) 8, a controller 110, a monitor display 80 are provided in the shield room 1.
Is arranged. The ultrasonic probe 8 is connected to the transmission / reception unit and the electronic scanning unit 9 of the ultrasonic diagnostic apparatus main body 6 arranged outside the shield room 1 by a cable 150 constituted by a coaxial flat cable or the like. The echo signal obtained by the transmission / reception unit and the electronic scanning unit 9 is signal-processed by a signal processing circuit (not shown), stored in the image memory unit 10 as image data, and displayed on the monitor display 80 inside the shield room 1. It is displayed as a sound wave image. A measured magnetic field waveform and the like are output to the monitor display 80 in the same manner as in the configuration of FIG.

FIG. 9 is a diagram showing a configuration of the ultrasonic probe 8 used in the embodiment of the present invention. As the piezoelectric ceramic (vibrator) 14 constituting the ultrasonic vibrator, a piezoelectric body obtained by polarizing ceramics such as lead zirconate titanate and lead titanate with a high electric field to have a piezoelectric characteristic, or polyvinylidene fluoride (PVDF) ) Is used. In particular, when an ultrasonic probe is used in the vicinity of a SQUID magnetometer, it is desirable to use PVDF made of a nonmagnetic material. A signal electrode 21-1 is formed on the first surface of the piezoelectric ceramic 14, and a high-voltage electrode 21-2 is formed on the second surface. Acoustic matching with a living body is formed on the upper surface of the signal electrode 21-1. An acoustic matching layer 13 is formed. The acoustic matching layer 13 is formed by mixing fillers (fillers) of various non-magnetic materials in epoxy resin, fused quartz, or the like, and has an optimal acoustic impedance.

For example, when acoustic matching is performed in one layer, as is well known, when the wavelength of an ultrasonic wave is λ, the acoustic impedance of a medium (here, a living body) is Z _M , and the acoustic impedance of a piezoelectric ceramic is Z _0. , The impedance is λ (Z _M Z ₀ ), and the thickness is λ / 4. In many cases, the acoustic matching is composed of multiple layers. On the upper surface of the acoustic matching layer 13, an acoustic lens 12 for forming a beam for focusing emitted ultrasonic waves is arranged.

For example, an acoustic lens 12 in which a filler such as SiO _{2 made of a} nonmagnetic material is mixed with silicon rubber and the sound velocity, acoustic impedance, ultrasonic attenuation, etc. are set to optimal values is used. The sound speed of the acoustic lens is about 1500 m / s
ec, the acoustic impedance is preferably about 1, 5 MRayls, and the ultrasonic attenuation is preferably as small as possible. On the back surface of the piezoelectric ceramics 14, a backing (backing) material 20 is provided.
Are arranged, and the rear braking member 20 is a piezoelectric ceramic 14.
(Vibrator) and has the function of acoustically damping and shortening the ultrasonic pulse waveform. The rear braking member 20 is formed by press-molding a powder of a non-magnetic material such as tungsten oxide or titanium oxide in an epoxy resin.
The signal electrode 21-1 and the high voltage electrode 21-2 are connected to the connector 22.
Is electrically connected to the transmission / reception unit of the ultrasonic diagnostic apparatus main body 6 and the electronic scanning unit 9 by a cable 150 constituted by a coaxial flat cable or the like.

Most of the acoustic lens 12, the acoustic matching layer 1
3, electrodes 21-1, 21-2, piezoelectric ceramics 14,
The rear brake material 20, the connector 22, the cable 150, etc.
It is stored in a case 28. The case 28 is preferably made of plastic, and when it is necessary to provide an electromagnetic shield, the case 28 is electromagnetically shielded with a nonmagnetic material such as aluminum or copper.

FIGS. 10 (a), 10 (b), 10
(C), FIG. 10 (d), and FIG. 10 (e) are views in the slice direction (indicated by F) of the ultrasonic probe including the arrayed transducers used in the shield room in the embodiment of the present invention. It is a figure showing an example of a range. FIG. 10 (a), FIG.
(B) Linear array probe (one-dimensional array transducer)
Show the visual field ranges 16a and 16b when G is used, G is the electronic scanning direction, and F is the slice direction. FIG. 10 (a)
FIG. 10B shows a field of view 16 a when the ultrasonic waves generated from the ultrasonic array (piezoelectric ceramics) 14 are narrowly focused by the acoustic lens 12, and FIG. Field 16b for obtaining a three-dimensional ultrasonic image of the body surface of the fetus integrated in the slice direction (indicated by F) so as to focus the obtained ultrasonic waves more widely by the acoustic lens 12
Is shown.

FIGS. 10 (c) and 10 (d) show that the piezoelectric ceramic is divided in the slice direction (indicated by F) and that the slice direction is the same as the electronic scanning direction (indicated by G).
Field-of-view ranges 16c and 16 when using a probe (two-dimensional array transducer) that focuses ultrasonic waves by electronic scanning
d. FIG. 10C shows a visual field range 16c when the focus of the ultrasonic wave is narrowed by the electronic scanning in two directions. In FIG. 10D, the focus of the ultrasound is widened by the electronic scanning in two directions, and a three-dimensional ultrasound image of the body surface of the fetus can be obtained. FIG. 10 (e) shows a one-dimensional array transducer portion 23 of a linear array or a convex array in the acoustic coupling agent inside the ultrasonic probe 8.
Field of view range 16e obtained as three-dimensional data by mechanically rotating in a scanning direction orthogonal to the electronic scanning direction
H is the rotation direction and G is the electronic scanning direction.

By the ultrasonic scanning shown in FIG.
An arbitrary cross section can be displayed, and furthermore, a three-dimensional image of a blood vessel can be obtained by using CFM (color flow mapping. Mechanical rotation is preferably performed by a method such as an ultrasonic motor, which hardly generates a magnetic field. (C) The three-dimensional scanning shown in FIG. 10 (e) can be electronically performed using the two-dimensional array transducer shown in FIG. 10 (d).

FIGS. 10 (a), 10 (b), 10
(C), FIG. 10 (d), and FIG. 10 (e), the ultrasonic probe composed of the arrayed transducers used in the shield room in the embodiment of the present invention can be arranged below the cryostat 2. . FIG. 11 is a view for explaining an embodiment in which the ultrasonic probe for performing the mechanical scan shown in FIG. 10E is arranged below the cryostat 2. The ultrasonic probe 8 is attached to a rack and pinion 30-1 fixedly arranged below the cryostat 2 by a holder 30-2.
Attached through. By turning the vertical adjustment dial 25-1, the ultrasonic probe 8 can move up and down along the side surface of the cryostat 2,
Further, the contact angle of the ultrasonic probe 8 with the living body surface can be changed by turning the dial 25-2, and the distal end surface of the ultrasonic probe 8 can be brought into close contact with the living body surface 29.

As described above, the one-dimensional array vibrator portion 23 can be rotated in the acoustic coupling agent inside the ultrasonic probe 8. One-dimensional array transducer part 2
The rotary motion of 3 may be driven by an ultrasonic motor or the like, and when noise during driving becomes a problem, the one-dimensional array transducer 23 is manually adjusted to the optimum position by the transducer direction setting dial 24. Can be fixed and used. As a result, for example, as shown in FIG. 11, the fetus 3 inside the uterus 33 of the subject 29 in a specific direction in the visual field range 16e.
1 is obtained, the position of the lower surface of the cryostat for keeping the superconducting quantum interference device at a low temperature with respect to the position of the heart 32 of the fetus 31, and the magnetic field signal detected from the heart 32 of the fetus 31 Adjust to be larger. The method described above is particularly effective when measuring the magnetic field generated from the fetal heart, and the movement of the fetal blood flow and the like is monitored by the ultrasonic diagnostic apparatus simultaneously with the measurement of the fetal cardiac magnetic field by the biomagnetic field measuring apparatus. it can.

When measuring the magnetic field generated from the twin fetal heart, the position of the heart of each twin fetus is confirmed using the ultrasonic probe 8 described above, and the heart of each fetal heart is measured. By bringing the lower surface of the cryostat closer to the above, the magnetic field signals generated from each fetal heart can be separately measured. In the above description, the case where the ultrasonic probe for performing the mechanical scan shown in FIG. 10E is arranged below the cryostat 2 has been described as an example.
10 (a), 10 (b), 10 (c), 10
(D) Also in the case of the ultrasonic probe shown in FIG. 10 (e) and composed of one-dimensional or two-dimensionally arranged transducers used in a shield room, it can be arranged below the cryostat 2.

FIGS. 10 (a), 10 (b), 10
(C), an ultrasonic probe comprising an arrayed transducer used in a shield room in the embodiment of the present invention shown in FIGS. 10 (d) and 10 (e) is replaced with a gantry 180 holding the cryostat 2; Can be placed in a part of FIG.
FIG. 11 is a view for explaining an embodiment in which the ultrasonic probe for performing the mechanical scan shown in FIG. The circumferential direction of the cryostat 2 (R1
One direction) is surrounded by an inner guide rail 35-2, and the guide rail 35-2 is supported by an inner support 35-4.
Is held on the gantry 180.

Further, outside the inside guide rail 35-2, the outside guide rail 35-1 is held on the gantry 180 by the outside support 35-3. The rack and pinion 30-1 is configured to be rotatable between the outer guide rail 35-1 and the inner guide rail 35-2 in the circumferential direction of the cryostat 2 (R11 direction).

A stopper 34 for fixing the rotational position of the rack and pinion 30-1 between the outer guide rail 35-1 and the inner guide rail 35-2 is provided on the rack and pinion 30-.
1 is provided at the upper end. Rack pinion 30-
An ultrasonic probe 8 for performing a mechanical scan with a configuration shown in FIG. 11 is arranged below the cryostat 2 at the lower end of the cryostat 2. The method of bringing the distal end surface of the ultrasonic probe 8 into close contact with the living body surface 29 is the same as that described with reference to FIG. 11. In the configuration shown in FIG. 12, the ultrasonic probe 8 is moved at any position in the circumferential direction of the cryostat 2. , Living body surface 2
9 can be adhered.

In the above description, the ultrasonic probe for performing the mechanical scan shown in FIG.
0 has been described as an example.
(A), FIG. 10 (b), FIG. 10 (c), FIG. 10 (d),
1 used in the shield room shown in FIG.
In the case of an ultrasonic probe including a two-dimensional or two-dimensionally arranged transducer, it can be arranged in a part of the gantry 180.

FIG. 13 is a diagram for explaining the configuration of the monitor display 80 according to the embodiment of the present invention. The monitor display 80 has a controller 110 and a display screen. The ultrasonic images in the modes set by the setting buttons 17a to 17d of the various measurement (photographing) modes are displayed.
As a mode that can be set, an A mode setting button 17a (see FIG.
Middle button A), B-mode setting button 17 for obtaining tomogram
b (button B in FIG. 13), M mode setting button 17c (button M in FIG. 13) for observing temporal movement of the tissue wall, Doppler mode or CFM mode setting for monitoring blood flow movement There is a button 17d (button Dop in FIG. 13) and the like. Each of the A mode, the M mode, the Doppler mode, and the CFM mode operates alternately with the B mode.

The ultrasonic image is displayed on the gain adjustment button 17e.
(The button Gain in FIG. 13) and the focus adjustment button 17f (the button Focus in FIG. 13) can be adjusted to obtain a clear image. When you want to print out an ultrasonic image, use the freeze button 17h (FIG. 13).
By pressing the middle button Freeze, the screen is paused and the print start button 17g (button Prin in FIG. 13) is pressed.
By pressing t), a paused ultrasound image can be printed. In the above description, the ultrasonic image is displayed on the monitor display 80, but the display data is not limited to the ultrasonic image. For example, the waveform of the electrocardiogram and the waveform of the cardiac magnetic field obtained by the SQUID magnetometer Can also be displayed at the same time.

It is desirable that the monitor display 80 be constituted by a liquid crystal display or a plasma display which generates little magnetic field noise. The various buttons 17a to 17h of the monitor display 80 are configured to have a touch panel type button, or the various buttons 17a to 17h of the monitor display 80 are provided with a function of lighting and are installed separately from the monitor display 80. And a display lamp for lighting and displaying a mode such as an ultrasonic image controlled by the controller 110.

FIG. 14 is a view for explaining the arrangement of the control section and the ultrasonic probe support of the ultrasonic diagnostic apparatus according to the embodiment of the present invention. Controller 110 of ultrasonic diagnostic apparatus
Is usually arranged beside the bed 4, and the controller 110 can be detached from the bed 4 as needed to use it in a handy type. The control by the controller 110 is the same as that shown in FIG. 13, and is executed by selecting various measurement (photographing) mode setting buttons 17a to 17d, a gain adjustment button 17e, a focus adjustment button 17f, a freeze button 17h, and a print start button 17g. You.

The controller 110 shown in FIG. 14 and the ultrasonic diagnostic apparatus main body 6 shown in FIG. 7 are connected by communication means using infrared rays or electrically connected by a cable. Various data including a control signal and image data is exchanged with the ultrasonic diagnostic apparatus main body 6. The control contents of the controller 110 are shown in FIG.
Is lit on the display screen of the monitor display 80. An ultrasonic probe support 26 and an ultrasonic probe support 27 are arranged beside the bed 4. When the operator performs measurement by the ultrasonic diagnostic apparatus at the same time as the cardiac magnetic field measurement, the operator adjusts the ultrasonic probe support 26 so that the ultrasonic probe 8 is not in contact with the cryostat 2 and the part of the subject to be measured. And fix it so that the measurement site is within the field of view.

If the measurement by the ultrasonic diagnostic apparatus is not necessary at the same time as the measurement of the cardiac magnetic field, the ultrasonic probe 8 is placed on the ultrasonic probe support 27 beside the bed 4 and, if necessary, measured by the ultrasonic diagnostic apparatus. Can be executed. In addition, various measurement (photographing) mode setting buttons 17a to 17d,
Gain adjustment button 17e, focus adjustment button 17
f, a freeze button 17h, and a print start button 17g may be provided outside the ultrasonic probe 8.

FIG. 15 is a view for explaining the detailed configuration of the ultrasonic probe support 26. Spindle rotation perpendicular to the plane of the bed 4 of the rotary shaft member 26-1 is (R ₁ direction) coupled, the arm member 26-2 having a telescopic mechanism for varying the length of the long direction (L direction) one end, rotating the main shaft of the rotary shaft member 26-1 (R ₂ direction) capable coupled, retaining member 26-3 for holding the ultrasound probe 8, the other end of the arm member 26-2, the arm member 26 rotation about the axis of -2 (R ₃ direction) are coupled. R ₁ , R ₂ , R ₃ direction rotation and L
By adjusting the length in the direction, the distal end surface of the ultrasonic probe 8 is brought into close contact with the living body surface 29.

[0061]

As described above, according to the present invention,
When measuring the magnetic field generated from the heart of the subject (adult or fetus), the operator can observe the position of the subject's heart almost in real time using an ultrasonic tomographic image inside the shield room, so the optimal measurement position The position of the SQUID magnetometer can be quickly adjusted, and the magnetic field generated from the subject's heart can be detected with high sensitivity and sharpness. In addition, while observing the position of the heart of the fetus with an ultrasonic tomographic image, the position of the lower surface of the cryostat 2 can be adjusted so that the magnetic field signal from the heart of the fetus is maximized, and the cryostat 2 can be brought into close contact with the body surface. The measurement of the magnetic field signal from the fetal heart and the observation of the blood flow state in the heart can be performed in the shield room at the same time.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a biomagnetic device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a biomagnetic device in a shield room according to an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of measuring a magnetic field emitted from a fetal heart according to an embodiment of the present invention.

FIG. 4 is a diagram showing an example of a screen showing a result of measurement of a magnetic field emitted from a fetal heart according to the embodiment of the present invention.

FIG. 5 is a diagram showing an example of a screen showing a result of measurement of a magnetic field emitted from a fetal heart according to the embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of an air mat according to the embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a biomagnetic field measuring apparatus according to an embodiment of the present invention.

FIG. 8 is a diagram showing an overall configuration of an ultrasonic diagnostic apparatus used in the biomagnetic field measuring apparatus according to the embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of an ultrasonic probe used in the embodiment of the present invention.

FIG. 10 is a diagram showing an example of a visual field range in a slice direction of an ultrasonic probe including an arrayed transducer used in the embodiment of the present invention.

FIG. 11 is a diagram illustrating a configuration in which an ultrasonic probe is arranged below a cryostat in the embodiment of the present invention.

FIG. 12 is a view for explaining a configuration in which an ultrasonic probe is arranged in a part of a gantry in the embodiment of the present invention.

FIG. 13 is a diagram illustrating a configuration of a monitor display according to an embodiment of the present invention.

FIG. 14 is a diagram illustrating an arrangement of a control unit and an ultrasonic probe support of the ultrasonic diagnostic apparatus according to the embodiment of the present invention.

FIG. 15 is a diagram illustrating a detailed configuration of an ultrasonic probe support according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Shield room, 2 ... Cryostat, 4 ... Bed, 6 ... Ultrasonic diagnostic apparatus main body, 8 ... Ultrasonic probe, 9
... Transceiver and electronic scanner, 10 ... Image memory, 1
DESCRIPTION OF SYMBOLS 1 ... Heart rate detection unit, 12 ... Acoustic lens, 13 ... Acoustic matching layer, 14 ... Piezoelectric ceramics (vibrator), 15-
1, 15-2, 15-3, 15-4, 16a, 16b,
16c, 16d, 16e, 17a: A mode setting button, 17b: B mode setting button, 17c: M mode setting button, 17d: Doppler mode or CFM mode setting button, 17e: Gain adjustment button, 17f: Focus adjustment button, 17g … Print start button, 17h…
Freeze button, 19a ... SQUID magnetometer operation button, 19b ... data collection start button, 19c ... remote control lever, 20 ... rear brake material, 21-1 ... signal electrode, 21-2 ... high voltage electrode, 22 ... connector, 23 …
One-dimensional array vibrator part, 24 ... vibrator direction setting dial, 25-1 ... vertical direction adjustment dial, 25-2 ... dial, 26 ... ultrasonic probe support, 26-1 ... rotating shaft member, 26- 2... Arm member having a telescopic mechanism, 26-3.
Holding member for holding the ultrasonic probe, 27: ultrasonic probe support, 28: case, 29: living body surface, 30-1
... rack and pinion, 30-2 ... holder, 31 ... fetus,
32: heart, 33: uterus, 34: stopper, 35-1 ...
Outer guide rail, 35-2 ... Inner guide rail, 35
-3: outer support, 35-4: inner support, 50: drive detection circuit, 60: amplifier filter unit, 80: monitor display, 90: computer, 100: speaker, 110: controller, 120: limb lead electrocardiogram Total
130 ... maternal heart, 140 ... fetal heart, 150 ... cable, 165 ... fetal heart rate synchronous flashing light, 175 ...
The part that displays the heart rate of the fetus, 180 ... Gantry,
185: Maternal heart-beat synchronous flashing light, 195: Part for displaying the maternal heart rate, 205: Maternal electrocardiogram, 21
5: magnetic field distribution diagram, 225: current distribution diagram, 235: magnetic field,
Lines representing the time at which the current distribution diagram is displayed, 245: air mat, 255: guide for preventing overturn, 265: flat portion, 275: air input portion, 285: lever for vertical movement, 295: rail, 305: wheels, 315: Bed top plate, A: Movement in x direction, B: Movement in z direction, C: Movement in y direction, D: Rotation in xz plane, E: Rotation in yz plane, F
... Slice direction, G: Electronic scanning direction, H: Rotation direction.

Continued on the front page (72) Inventor Hitoshi Sasabuchi 882 Ma, Hitachinaka-shi, Ibaraki Pref.Hitachi, Ltd.Measurement Equipment Division (72) Inventor Kenji Teshigawara 882 Ma, Hitachinaka-shi, Ibaraki Pref.Hitachi, Ltd.Measurement Instruments Division, Hitachi, Ltd. (72) Inventor Hiroyuki Suzuki 882-Hita, Hitachinaka-City, Ibaraki Pref. Inventor Ryuichi Shinomura 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (56) References JP-A-7-308303 (JP, A) JP-A-6-269426 (JP, A) JP-A-5-115459 (JP, A) JP-A-10-248821 (JP, A) JP-A-11-151219 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 5 / 05

Claims (1)

(57) [Claims] A bed for supporting a subject, and a bed for supporting the subject.
The component (B _z ) in the normal direction (z direction) of the magnetic field generated from
A class that keeps a plurality of SQIUD magnetometers to be detected at low temperature.
An iostat and means for holding the cryostat;
Are placed in a shield room and the plurality of SQIUDs
Driving the magnetometer, and transmitting signals from the plurality of SQIUD magnetometers
And a drive detection circuit for detecting the signal, and an output of the drive detection circuit.
Using the collected and detected normal component (B _z ) in the normal direction
From {((dB _z / dx) ² + (dB _z / dy) ² )}
A computer that performs arithmetic processing for obtaining the magnetic field distribution map
The subject's ECG in the shielded room
Waveform, distribution of the magnetic field obtained by the arithmetic processing,
Any one or more of the current distributions obtained by the arithmetic processing
Biomagnetic field having display means for displaying
Measuring device.