JPS60222030A - Magnetic measuring method and apparatus of temperature in living body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for magnetically measuring the desired internal temperature of an animal or plant for various purposes such as diagnosis, treatment, observation, observation, etc., and an apparatus directly used for carrying out the method. Regarding.

BACKGROUND OF THE INVENTION One method of destroying only cancer cells without destroying normal cells is to warm the temperature of the area where cancer cells are located to about 43°C.

Microwave irradiation is also used as a method to raise the body temperature at a designated location to a specified temperature, but it is difficult to measure the temperature at that location to see if it has reached the desired temperature.

Currently, there are methods of implanting a thermistor thermometer into the body and extending lead wires outside the body to measure the temperature at a designated location, and nuclear magnetic resonance computed tomography ('NMR-CT).
A method of measuring temperature based on the relaxation time is used.

Problems to be Solved by the Invention Thus, the present invention uses a magnetic material to convert humidity information into a magnetic signal in a simple and accurate manner when it is necessary to measure local body temperature in a living body for various purposes.

The purpose is to provide a method and device for reliable measurement.

Means to solve problems The basic principle of the method of the present invention will now be explained with reference to FIG.

A small magnet with length 1 and magnetic pole strength m is considered to be a magnetic dipole with magnetic moment M=m + if length 1 is minute compared to the distance to the measurement point. This magnetic dipole is located at an arbitrary point D (Xd
, Yd, Zd) parallel to the X axis, any point P(XI).

The strength of the magnetic field at Yl), Zp) is given by:

3(Fl-'#")W Fl where M is the magnetic charge of the dipole, and R is given by the following equation.

Hundred = (Xp-Xd) cross + (Yp-Yd)? (Zp-Z
d)2 Here, if the positional relationship between the magnetic dipole and the measurement point is constant, the strength of the measured magnetic field changes according to the change in the magnetic moment M.

Recently, magnetic materials whose magnetic properties change rapidly at 40 to 50°C have been developed. A small magnetic dipole is made using this magnetic material, and as shown in Figure 2, it is inserted into the desired location within the body α, and the magnetic flux density is measured from the outside by several tens of tens of degrees.
When magnetized with a magnetic field of 0 Gauss, the magnetic material β will have a magnetic moment M proportional to the strength of the external magnetic field. This magnetic moment M varies greatly depending on the temperature of the magnetic material β. Therefore, by measuring the magnetic field generated by this magnetic dipole outside the body at the same location, it is possible to measure the magnetic moment M, and therefore the temperature at the location where the magnetic material β is inserted.

EXAMPLE An example of the method of the present invention applied to cancer treatment using the principle will be described with reference to FIG.

In the method of the present invention, a magnetic material β made of ferrite with a Curie temperature of 42.5°C, which is almost comparable to the cancer cell destruction temperature of 43°C, is heated locally at the affected area by irradiating it with concentrated microwaves from the outside. An external magnetic field consisting of a steady magnetic field of approximately 200 Gauss is applied to the magnetic material β, which has been implanted in advance in the body α, to magnetically induce the magnetic material β, and then the external magnetic field is removed, and the magnetic material β is then placed at the affected measurement point. By locally heating the area by irradiating microwaves from the outside, changes in the residual magnetic field of the magnetic material β, which converts temperature information at the affected measurement point into magnetic information, are sequentially detected and measured outside the body using a flux probe F'P. When the temperature at the affected area measurement point reaches the Curie temperature of 42.5°C, which is almost the same as the cancer cell destruction temperature, the magnetic material β changes from a ferromagnetic material to a constant magnetic material, and the residual magnetic field begins to decrease rapidly. Capturing the residual magnetic field at the moment,
It was possible to measure and confirm that the temperature at the affected area measurement point had reached the critical temperature of 42.5°C, at which the magnetic properties of the magnetic material β, which was a ferromagnetic material, suddenly changed, and the affected area measurement point always maintained the critical temperature. The concentrated microwave irradiation can be controlled to destroy and treat the affected cancer cells at the measurement location.

Here, an experimental example of the present invention will be explained.

A ferrite material with a Curie temperature of 42.5°C was used as the magnetic material, and it was embedded in silicone rubber made to resemble a living body, and the magnetic field generated from it was measured while changing the temperature.

FIG. 3 shows the measurement results. Here, a flux gate magnetometer is used to measure the magnetic flux, and at a temperature of 52°C, approximately 2
Magnetization is performed by applying a DC magnetic field of 0.00 Gauss.

In actual biological measurements, the magnetic field generated by the magnetic dipole outside the body is extremely small compared to the earth's magnetism, so special measures are required. In order to use a highly sensitive magnetometer such as a flux gate magnetometer, and to cancel out various magnetic noises from the earth's magnetic field and cities, two or more magnetic flux detection coils CI and C2 are connected in opposite directions to each other, as shown in Figure 4. is connected to. Thereby, only the magnetic field H from the magnetic material β for temperature measurement, which is close to the source, can be measured. Furthermore, since the magnetic field from the magnetic material β is a steady magnetic field that does not fluctuate, unlike a fluctuating magnetic field, it is difficult to measure. Measurements are performed when the probe is brought close to the probe FP and when it is separated from the probe FP, and the DC magnetic field is measured from the difference in the magnetic field H.

Embodiments of the apparatus of the present invention will now be described with reference to FIGS. 5 to 10.

The device A of the present invention includes a measurement system section B and a drive system section C.
and the signal processing system department, and the treatment system department E.
can also be attached. As shown in FIGS. 6 and 7, the measurement system section B includes a pair of magnetizers placed on one side of the ceiling section 2 and the floor section 3 of the non-magnetic structure 1 made of wood, plastic, etc., and vertically opposed to each other. 4 and 5, and fix the differential probe 6 inside the floor stand 3.
A measuring bed 7 on which the subject α can lie supine is placed movably in the front-rear Y-axis direction and the left-right X-axis direction, and the drive system section C excites and demagnetizes the pair of upper and lower magnetizers 4 and 5. It is equipped with a magnetizer power supply section 8 to control and a bed drive control section 9 to drive and control the measurement bed 7, and the signal processing system section appropriately pre-processes the magnetic measurement signals S1', 81'' obtained from the differential probe 6. A microcomputer (hereinafter referred to as microcomputer) that processes the input and issues an operation command signal to the drive system section C.
It is equipped with 10.

As shown in FIGS. 6 to 8, the structure 1 includes a floor base portion 3
The floor base part 3 includes a pair of left and right L-shaped guides 12 and 13 that extend along the entire length of the left and right edges of the rectangular floor frame 11 in parallel in the front-back direction. The left and right guides 1 are mounted on the left and right sides, and the left and right guides 1
2.13, the intermediate guide plate 14 is extended and fixed in parallel, and the housing part 15 of the lower magnetizer 5 is arranged in the left half and rear half position in the floor table part 3, and A differential probe 6 is fixedly protruding upward from the center of the front side, and its upper end is exposed to the lower side of the measurement bed 7.

The ceiling part 2 is constructed by supporting the lower ends of the four corners of the large rectangular frame 16 by four pillars 17, 18, 19, 20, and forming the floor frame 11.
The housing part 21 of the upper magnetizer 4 is placed in the rear half position in the top frame 16, which spans over the left half of the
is provided.

The measurement bed 7 has three pairs of left and right middle beams 22, 23, and 24 that are placed on the left and right guides 12, 13 on the floor frame 11 and on the intermediate guide plate 14 so as to be slidable in the front and rear Y-axis directions. A front-shaped guide 25 extending across the front ends and a trailing-shaped guide 26 extending across the rear ends face each other and extend parallel to each other in the left-right direction to form a wave tube, and between the front and rear-shaped guides 25.2'6. A bed receiving frame 29 is formed by corrugating front and rear filter media 27° 28 which extend parallel to each other in the left and right direction at a required interval over the right beam 23 and middle beam 24, and on the other hand, the bed receiving frame 29 is provided with a front and back guide. A sliding wedge plate 30, on which the subject α can lie supine, is fitted between 25 and 26 so as to be slidable in the left-right direction.

In the figure, reference numerals 31, 32, 33, 34, and 35 indicate a group of plastic guide rollers that are partially exposed and embedded so that they can freely roll.

As shown in FIGS. 6 and 9, the bed drive control section 9
, a Y-axis circumferential pulse motor 37 and an X-axis pulse motor 38 are installed in parallel on a stand 36 that is separate from the structure 1 to prevent the differential probe 6 from being adversely affected by magnetism, and a floor stand. Interposed between the frame 11 and the right half of the measurement bed 7, the drive torque of the Y-axis circumferential pulse motor 37 and the X-axis pulse motor 38 is transferred to the Y-axis and X-axis circumferential transmission shafts 39.40.
The Y-axis circumferential drive transmission mechanism 41 consists of Y-axis and X-axis drive transmission mechanisms 41 and 42 that transmit data to the measurement bed 7 via the The terminal end of the Y-axis circumferential transmission shaft 39 is penetrated between the left and right brackets 45 and 46 that are arranged opposite to each other on the left end of the association 43 and 44, and a driving sprocket (not shown) is fixed thereto, and the left and right brackets 47 and 48 A driven sprocket (not shown) is fixed by penetrating the sprocket shaft 49 between them, and a timing belt 50 is stretched endlessly between the driving sprocket and the driven sprocket (neither of which are shown), and the timing belt 50 is stretched halfway through the shaft. 27
．． The bed support frame 29 is fixed to an adapter 51 provided vertically on the lower side of the bed support frame 28, and is integrally movable in the front and rear Y-axis directions as the timing belt 50 rotates.

The X-axis circumferential drive transmission mechanism 42 has a bearing 52 and a decelerator 53 fixed opposite each other on the central part of the front and rear assemblies 43 and 44, and both ends of the squirrel brine shaft 54 are penetratingly supported between the bearing 52 and the decelerator 53. On the one hand, a pinion 55 interposed on the upper side between the front and rear crossing points 27.28 is spline-fitted to the spline shaft 54 so as to be able to slide freely in the axial direction, and on the other hand, a rack rod 56 that engages with the upper side of the pinion 55 is attached to a sliding wedge plate. The slide wedge plate 30 is attached and extends in the left and right X-axis directions at the center of the lower side, and as the spline shaft 54 rotates, the slide wedge plate 30 is integrally movable in the left and right X-axis directions via a pinion 55 and rack rods 56 and 56.

In the reducer 53, a large-diameter bevel gear (not shown) is fixed to the end of the spline shaft 54 passing through, and a small-diameter bevel gear (not shown) meshing at right angles with the large-diameter bevel gear is attached to the end of the X-axis transmission shaft 40 passing through the reducer 53. It is fixed.

57 in the figure is a right angle bearing, and the Y-axis peripheral pulse motor 3
Y
It is fixed to the starting end of the circumference transmission shaft 39, and 59 is a decelerator, which is internally meshed at right angles with a small-diameter bevel gear (not shown) fixed to the passing end of the motor shaft 60 of the X-axis pulse motor 38. A large-diameter bevel gear is fixed to the starting end of the X-axis transmission shaft 40 passing through the reducer 59.

As shown in FIG. 11, the signal processing system section connects a forward-wound first detection coil 6a and a reverse-wound second detection coil 6b of the differential probe 6 to a flux gate type first magnetometer 61 and a flux gate type first magnetometer 61, respectively. - Connected to the gate-type second magnetometer 62, and input analog measurement value signals S2' and S2'' output by magnetoelectric conversion from the first magnetometer 61 and the second magnetometer 62 to the differential amplifier 63 in parallel. Cancels other magnetic components and amplifies the signal.

The principle of the flux gate type magnetometer 64 is that the first and second detection coils 6a and 6 at the tip of the differential probe 6
The minute magnetic flux entering b is switched by high frequency signals from the first and second magnetometers 61 and 62, and amplified as a high frequency signal. The output from the flux gate type magnetometer 64 is for differential use.
Differential probe 6 or flux gate magnetometer 6
4 and 10m V P+! Since it is taking in the commercial frequency of 300 Hz, it is not possible to gain much gain, so the gain is fixed at about 40 dB and common mode noise is removed by using a high impedance input resistor.

65 in FIG. 10 is a piphod low-pass filter, and the output signal from the differential amplifier 63 contains many frequency components, and the required data is 1l-1.
The output signal of the differential amplifier 63 is inputted because it is almost a direct current component of less than z. IHz, 10Hz, 1
The frequency can be changed to 00Hz.

66 is a measured value A/D converter circuit, and in order for the microcomputer 67 to process the magnetic field measured by the flux gate type magnetometer 64, the measured value must be A/D converted. The A/D conversion start signal S3 is sent to the counter 6.
It is created by software using the output port address using 8 signals.

Reference numeral 69 is an input/output crab unit which is directly connected to the microcomputer 67 and mediates input/output signals.

70, 71, 72 are D/A converters, voltage -
A current converter, a correction coil, and a D/A for correction current.
Even if you configure the converter section and use the differential probe 6, if the geomagnetism cannot be completely canceled depending on the position where it is set, a correction coil 72 is added to the differential probe 6, and a correction DC coil 72 is added to the differential probe 6. A current is applied to completely cancel it out. That is, it is a circuit necessary for flowing a correction current to the correction coil 72 attached to the first and second detection coils 6a and 6b of the differential probe 6, and the current must be a constant current. Therefore, the voltage output by the D/A converter 70 is converted into a current, and a correction current is applied.

The D/A converter 70 selects a 12-bit analog output range of ±5V, and converts this ±5V output to ±10m using a voltage-to-current converter 71 using an operational amplifier.
It is converted to a constant current of A. Correction ability is ±5V D/A
The output can be ±950μG.

Reference numeral 73 is a pulse motor control, in which a control signal S4 for the Y-axis circumferential pulse motor 37 and the X-axis circumferential pulse motor 38 for driving the bed 7 is inputted by the microcomputer 67 via the input/output crab unit 69, and the Y-axis Frequency pulse motor 3
Drive pulse signals S5' and S5'' are output to the pulse motor 7 and the X-axis pulse motor 38, respectively.

In the measurement position detection counter 68, the analog measurement value signals S2' and 82'' captured by the differential probe 6 are detected by the bed 7.
During driving, the driving pulse signals must be captured at precise positions on the body surface and A/D converted, so the driving pulse signals emitted from the pulse motor control 73 are counted and inputted from the microcomputer 67 via the input/output crab unit 69. A countdown is performed using the pulse signal S6, and when the value reaches zero, a measurement position detection pulse signal S7 is sent to the input/output crab unit 69, and a start signal S3 for the A/D converter circuit 66 is generated.

Reference numeral 74 denotes a microwave treatment device in the treatment system section E, which consists of a magnetron 75 with an output of 50 to 200 W and a directional antenna 76, which are controlled by a microcomputer 67 via an input/output unit 69, and a directional antenna 76, which adversely affects the differential probe 6 during measurement. On the condition that there is no magnetic structure, the directional antenna 76 can be installed magnetically shielded on the other side of the ceiling 2 as shown in FIG. It is installed separately and irradiates the affected area with concentrated microwave energy, making it possible to perform temperature measurement and cancer cell destruction treatment at the same time. In other words, the microcomputer 67 to which the measured temperature information of the affected area is inputted as feedback performs arithmetic processing and simultaneously sends o, n -o to the microwave treatment device 74.
, f Control signal S8 regarding timing, output change, etc.
The temperature of the affected area can be maintained at 43°C at all times.

In the case of the present invention, the microwave treatment device 74 is applied as the treatment device, but an ultrashort wave treatment device or an ultrasonic treatment device may be applied to the device for other treatments.

In the figure, 77, 78, and 79 are the floppy disk and display connected to the microcomputer 67.

It is a line printer.

Further, the differential probe 6 may hang down from the ceiling part 2 so as to be able to move up and down.

Since the apparatus A of the present invention is configured as described above, prior to measurement, the drive system section C, signal processing system section, and treatment system section E (not shown) are turned on and standby in an operable state.

Next, the subject α takes off accessories made of magnetic metal such as watches, glasses, necklaces, bracelets, etc., and lies supine on the sliding wedge plate 30 with the head turned to the left.

Continue to operate the microcomputer 10 so that the magnetic material β at the measurement point on the affected area of the subject α is positioned between the upper and lower magnetizers 4 and 5.
A pulse operation command signal commensurate with the amount of movement in the longitudinal Y-axis direction and the left-right X-axis direction is sent to the Y-axis circumferential pulse motor 37 and the X-axis circumferential pulse motor 38.
7 and 38 to move and position and stop the measurement bed 7 via the drive transmission mechanisms 41 and 42.

When the positioning is stopped, a magnetic field of 200 gauss is automatically applied between the upper and lower magnetizers 4°5 for a required period of time, and the magnets are automatically demagnetized.

When the magnet is automatically demagnetized, the microcomputer 10 issues data such as the pulse rate and number of operating pulses during acceleration/deceleration required for driving and other commands via the input/output crab unit 69 according to a preset program to drive the pulse motors 37 and 38 in forward and reverse directions. drive, move the measurement bed 7 in the Y-axis direction and the X-axis direction, position the affected area measurement point from the back side of the position where the magnetic material β is embedded on the differential probe 6, and move the differential probe each time. 6, the residual magnetism is detected by each of the first detection coil 6a and the second detection coil 6b, and the magnetic measurement signals St', S1'' are inputted to the first magnetometer 61 and the second magnetometer 62, and the analog measurement value signal 321 82'' and input it in parallel to the differential amplifier 63, the first detection coil 6a and the second detection coil 6b are connected in series in opposite directions via the first magnetometer 61 and the second magnetometer 62, respectively, on the way. and correction coil 72.
Since the correction current is flowing through the first and second detection coils 6a and 6b, the magnetic fields in places where the source of the magnetic field is far away, such as earth's magnetism, cancel each other out because they are parallel, and only the magnetic field from within the body is close to the source. As a result of measuring , the differential amplifier 63 outputs a genuine analog measurement value signal S9 related to the residual magnetism in the magnetic material β, and then filters 65 and A
/D converter circuit 66 and enters microcomputer 67 via input/output unit 69 to calculate and process the temperature of the affected area measurement point and sequentially output and display on line printer 79 and display 78.

Based on the temperature information of the affected area measurement point, the microcomputer 67 simultaneously controls the magnetron 75 via the input/output crab unit 69 to direct microwave energy from the directional antenna 76 to the affected area measurement point where the magnetic material β is embedded. Kake is intensively irradiated, and when the cancer cell destruction temperature is reached while local heating is progressing, the differential probe 6 detects a sudden change in magnetic properties at the Curie point temperature of the magnetic material β, and cancer cell destruction progresses. You can check what is being done on the display 78 or line printer 79.

In this way, the differential probe 6 constantly captures temperature information at the measurement point in the affected area, and based on that information, the microcomputer 67 controls the microwave treatment device 74 to keep the measurement point in the affected area at the cancer cell destruction temperature. .

Furthermore, in the present invention, the differential probe 6 is not disposed above the measurement bed 7, but is placed on the lower side, so that the differential probe 6 itself is exposed to the magnetic material β embedded in the measurement location of the affected area of the subject α. It can be fixed without the need to move up and down toward and away from the subject, and as a result, it can be fixed without touching the subject α, and the thickness of the site where the magnetic material β is implanted, gender and age, and in the case of the chest, at the time of measurement. Regardless of the state of liver suction, measurements can always be taken from a certain distance from the back, making it safe.

Furthermore, it is also possible to take the following steps: first irradiating microwave energy to the measurement site of the affected area where the magnetic material β is embedded, then applying an external magnetic field, and then measuring with a differential probe.

Thus, the present invention has excellent effects such as accurately capturing the temperature at a measurement point within the body using a magnetic material and being applicable to various treatments.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the magnitude of the magnetic field created by a magnetic dipole according to the principle of the present invention, Fig. 2 is an explanatory diagram of the magnetic measurement method of the internal body temperature of the present invention, and Fig. 13 is a diagram of the characteristics of the magnetic field with respect to temperature changes. , Fig. 4 is a connection diagram of the magnetic flux detection coil used in the differential probe, Fig. 5 is a block diagram showing the system concept of the device of the present invention, and Fig. 6 is a diagram showing the connection of the measurement system section, drive system section, and treatment system section. Fig. 7 is a front perspective view of the structure with the measurement bed removed, Fig. 8 is a front perspective view of the measurement bed partially disassembled with the floor base, and Fig. 9 shows the timing belt. Fig. 10 is a block diagram of the electronic circuit in the device of the present invention, and Fig. 11 shows details of the differential probe, 7 Lux Goo type 1-type magnetometer, and differential amplifier. This is a block diagram. A... Magnetic measurement device B... Measurement system section C...
・Drive system section D...Signal processing system section E...
・Treatment system section H...Residual magnetic field S1', Sl"・
... Magnetic measurement signal α ... Subject β ... Magnetic material 1 ... Non-magnetic structure 2 ... Ceiling part 3 ... Floor table part 4.5 ... Magnetizer 6 ...・Differential probe 7...
Measurement bed 63...Differential amplifier 64...Flux gate type magnetic flux controller 65...Filter 66...A/D converter circuit 67...Microcomputer 68...Position detection counter 69... Input/output crab unit 70...D/A converter 71...Voltage-current converter 72...Correction coil Fig. 1^ Fig. 2 Fig. 3 30 '40 5054 ('C) Fig. 4 Fig. 5 Figure 8 0 u 11

Claims (1)

[Claims] 1. A magnetic material is implanted in a living body at a measurement location, and an external magnetic field is applied to the magnetic material to induce magnetic induction, and then the external magnetic field is removed and temperature information at the measurement location is converted into magnetic information. 2. A magnetic measurement method for internal temperature of a living body, in which the residual magnetic field emitted from the magnetic material to be converted is detected outside the body and measured to measure the temperature at the measurement location. 3. Magnetic measurement method for internal body temperature according to claim 1, wherein the measurement location is heated locally by being irradiated with microwaves from the outside. Method 4: Magnetic measurement method for the internal temperature of a living body according to claim 3, wherein the local heating is made to substantially match the Curie temperature of the magnetic material. 5: The magnetic material has a temperature that substantially matches the cancer cell destruction temperature. Magnetic measurement method for internal body temperature according to claim 1, 2, 3 or 4 using a ferrite material having a curie temperature of 42.5° C. 6, non-magnetic structure ceiling Magnetizers are installed vertically opposite each other in the chamber and the floor table, and a differential probe is fixed in the floor table, and a measurement bed on which the subject can lie supine is placed in the front and rear Y-axis directions. A measuring system section mounted movably in the left and right X-axis directions, and an excitation operation of the magnetizer, as well as an X-axis pulse motor and a Y-axis pulse motor, move the measuring bed in the front-rear, Y-axis directions, and left-right X directions. A drive system unit that controls the drive in the axial direction, a 7 lux gate type magnetometer, and a differential amplifier that transmits the magnetic measurement signal obtained from the differential probe. The correction current value signal outputted from the input/output unit is input to the input/output unit which is directly connected to the microcomputer via the filter and A/D converter, and the corrected current value signal is outputted from the input/output unit via the D/A converter and voltage-current converter. While no correction current flows through the correction coil attached to the differential probe, the X-axis circumferential pulse motor and the Y-axis circumferential pulse - [-
The operation command signal is sequentially input from the input/output crab unit to the pulse motor control, which distributes drive pulse signals to the motor, and the measurement position detection counter counts the drive pulse signals emitted from the pulse motor control. and a signal processing system unit which inputs a measurement position detection pulse signal to the input/output crab unit.