JPS6238179A - Method and apparatus for forming heat point in electromagnetic induction type hyperthermia - 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 and apparatus for heating a local area within a conductive object using i-magnetic induction, and more specifically to a method and apparatus for heating a local area within a conductive object using i-magnetic induction. The present invention relates to a method and apparatus suitable for elevating and thermally treating cancer.

[Conventional technology]

Cancer cells and pig intestines are more sensitive to heat than normal tissue. A cancer treatment method that utilizes this characteristic is hyperthermia (
hyperthermia) has been attracting attention in recent years. This is intended to increase the temperature of the lesion to 42°C to 45°C to cause necrosis of cancer cells or to prevent their proliferation.

[The problem that the invention attempts to solve]

However, this hyperthermia technology has not yet been put to practical use because it is extremely difficult to concentrate the heat spot on the lesion. That is, if there is a foci deep within the composition,
It was difficult to form a hot printing only there.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for locally heating a conductive object, which can be applied to heat treatment of cancer, or to other medical and industrial applications.

A method for heating a local area within a conductive object according to the present invention for solving the above-mentioned problems and achieving the above object is a method for heating a local area within a conductive object. can be.

generating a first high-frequency alternating magnetic field whose center is on one side with respect to the center of the local area and set to penetrate the object; A second high-frequency alternating magnetic field is generated, which is located on the side of generating eddy currents within the body;
third and fourth high frequency alternating magnetic fields having substantially the same mutual relationship as the mutual relationship of the first and second high frequency alternating magnetic fields; generating a high frequency alternating magnetic field, thereby generating eddy currents within said object;
--, it is characterized by.

A local heating device within a conductive object according to the present invention is as follows.

A first for generating first and second high frequency alternating magnetic fields.
．． Second. In addition to the third and fourth magnetic poles, there is also a fifth magnetic pole for stopping the spread of the first and second high frequency alternating magnetic fields. 6th. 7th. It has an eighth magnetic pole.

[For production]

In the above invention, the first high frequency alternating G field and the second high frequency alternating S field 42 are in an antiphase relationship with each other.

Therefore, a large eddy current is generated in the first high frequency alternating S field and the second high frequency alternating S field in the fall area 7 due to electrical insulation. ] If only the first and second high-frequency alternating magnetic fields of the pair are used,
The heating region is generated in a columnar manner along the first and second high-frequency alternating S fields, but when the third and fourth high-frequency alternating B fields are generated with different angular position compensation, the heating region is generated at the intersection point of each high-frequency alternating magnetic field, that is, the desired Local temperature is highest. Therefore, 1 station P9T
It is possible to suppress the rise in temperature other than that and bring the local temperature to the desired temperature.

In the apparatus of the present invention, the fifth. 6th. The effect of the seventh and eighth magnetic poles suppresses the spread 9 of the first and second high-frequency alternating S fields, making it possible to heat minute portions.

〔Example〕

Next, a method and apparatus for heating a lesion of a human body according to an embodiment of the present invention will be explained with reference to FIGS. 1 and 2. The cancer focus area (2) in the human body is shown as a heat treatment device. ), when heating multiple virtual straight lines +31 (41+51 +
61, and four magnetic field generators (7+ f8+ (9+ (
Place 101.

Now, an explanation will be given using the two magnetic field generators 7) as an example.
And, 1st. i2. Third. & 4th f) Ko(#
011[12Ia: Has 10 cities and has high frequency exchange @M
z source (+51 is switch S.

It is connected with a valve. The first coil (111 is placed on one side of the human body (1) along the straight line (3), and the second coil Q21 is placed on the other side of the human body (1) along the @ line (3). The third filter 031 is located on the other side of the human body (1) along the p-line (3), and the fourth
The coil [+41 is ih! (Human body along 34fc (1
1 on one side. The first coil Qll and the fourth coil α41. The second coil 0Z and the third fill ( ) 31 are arranged in parallel with an interval determined according to the size of the cancer lesion (2). The third and fourth fill συq forces u: x +141 have the first polarity and the second polarity with respect to the direction toward the human body (1).
They are connected in series in order so that the polarity becomes , the first polarity, and the second polarity. This ninth class coil (II+-(1
For example, when the switch S1 is turned on at 41 and a high frequency current of 0 or more is caused to flow through the side 1, at a certain instant the arrow ! A first high frequency alternating S field indicated by 161 and a second high frequency alternating magnetic field indicated by arrow αn are generated. At this time, the first magnetic pole generated on the human body side of the first fill 011 becomes a polarity, the second magnetic pole generated on the human body side of the second coil Q2+ becomes a magnetic pole, and the third magnetic pole generated on the human body side of the third coil 030 becomes a magnetic pole. 3 a
The pole becomes a north pole, and the fourth magnetic pole generated on the human body side of the fourth filter t141 becomes a magnetic pole.

The centers of the first and second high-frequency alternating S-field forces are:

Although they are along the virtual straight line (3), they do not match.

The first Takayama-Oki-Yi-Yu-Yu-Kai-hi-Shin-tsume-wa-Yi-Kou-A-Tongue mW-shi-duke] which extends so as to sandwich the lesion (2) has a phase difference of 80 degrees, that is, an inverse phase relationship. ing. Therefore, the eddy current in the columnar part sandwiched by the first and second high-frequency alternating magnetic fields tlbI (+77) is generated more strongly than in other parts.The human body and the cancer focus part f21 have electrical conductivity. Therefore, an eddy current is generated due to electromagnetic induction based on a high frequency magnetic field. When an eddy current is generated as described above, Joule heat is generated and the temperature rises.

What is important here is to determine the thickness of the high-frequency current and the number of turns of the coils Qll to σ so that the temperature rise caused by the single magnetic field generator 17+ will not destroy the normal parts of the human body (1). It is. Therefore, a single magnetic field generator (7
), the temperature required for the lesion (2) (42℃-45℃)
It is difficult to raise with leaves. Therefore, the lesion area (2
A high frequency alternating magnetic field is also generated by the magnetic field generating device (81 (9+ (II) vc) at another straight line +41 +51 +61 intersecting with I!t can be made significantly higher than others.

039α special bite QD is the 5th. 6th. The seventh and eighth coils are the first and second 7rFJ frequency alternating field σtil
It is provided to limit the spread of Q71 by 1lIII. Although the wiring is omitted in FIG. 1, specifically, as shown in FIG. 3, it is connected to the U5IVC in the opposite direction to the first to fourth coils qυ~041. And the fifth. 6th. 7th and 8th coil Q8i (191 (2tJl
(The shuttle characteristics of each coil α■ to Zll are determined so that the polarity is the first polarity, the second polarity, the second polarity, and the third polarity based on the side facing the human body (1) of 211. Therefore, at a certain instant, as shown in Fig. 3, the 5th, 6th, 7th, and 8th coils O shallow α!JIG?υ2D are N
It becomes a pole, a magnetic pole, a magnetic pole, a north pole. The strength of the magnetic poles of the fifth to eighth coils is set so as to limit the spread of the first and second high-frequency alternating magnetic fields +161flη. ff1J A tongue that restricts the flow of magnetic flux between the first magnetic pole PI and the fourth magnetic pole P6 when they approach each other.

By using the repulsive action between the first magnetic pole P1 and the fifth magnetic pole lno, which are adjacent to each other with the same polarity, and the repulsive action between the fourth EB pole P4 and the sixth pole P6, No. 7 on the right.
and the eighth magnetic pole P? ,P are also used in the same way.

Note that the strengths of the fifth and sixth magnetic poles P, P, P, are set so that a flow of the foundation occurs between them. Seventh and eighth magnetic poles P? , Ps are similarly set.

In FIG. 1, the second magnetic field generator (81 is the first
The first magnetic field generating device fl (71, first to eighth co(
t111G21u:N(1410&clIclII
Corresponding to K, the 9th to 16th coils + 1la) (12a
month 138) (142 month 11'1a) 119aJ (2+l
a) +21a). This second magnetic field generator (
81 is.

First and second high frequency alternating magnetic fields a61 (third and fourth high frequency alternating magnetic fields +1fta in the direction perpendicular to 17) 11
7a)'P Except for the device that generates light, it is in the same direction as the first magnetic field generator (7). Therefore, detailed explanation thereof will be omitted.

The third and fourth magnetic field generators +91001 are arranged between the first and second magnetic field generators +71 and +81. In order to strongly heat the lesion (2) three-dimensionally, the coils of the third and fourth magnetic field generators +91 QOI are arranged in parallel in the vertical axis (Z#) direction. Therefore.

1g1 diagram shows λ of the upper coil.

FIG. 2 shows the relationship between the third magnetic field generator (91) and the inlet peak as seen from the low nIN in FIG. 1. The first, second, third, and Fourth coil (l])~
04; and the 17th to 20th fills (11b month 12b month 13b) corresponding to the 5th to 8th coils tta to 21)
) (14b) and 21st to 24th) Ile 118bJ
lISlbH20bH21bJ are provided respectively.

As shown in the arrow (16B) 117a,
Fifth and sixth high frequency alternating magnetic fields are generated. The configuration and operation of this third magnetic field generator (9) are as follows:
This device is the same as the first magnetic field generator (7) except that it generates a sixth high-frequency alternating magnetic field +1fibN17b). In FIG. 1, the fourth magnetic field generator αQ, indicated only by 1icJ (12cJ), has essentially the same configuration as the first magnetic field generator (7).

When heating the cancerous lesion (2) using the apparatus shown in FIGS. 1 to 3, the following steps are performed:
, the high frequency X current is sequentially applied to the first to fourth magnetic field generators (7) to Ql with a time difference. Due to this.

1! Eddy currents are generated by magnetic induction, and the cancerous lesion (2) is heated by Joule heat. At this time, no matter which of the first to fourth magnetic field generators (71 to QOI) an eddy current flows through the cancer focus part (2), the temperature of the cancer focus part (2) becomes the highest. At this time, eddy currents flow in areas other than the cancer focus area (2), and the temperature rises, but the heating by the eddy currents is not superimposed, so the temperature does not become very high.Please note that the heated area is the cancer focus area (2). If it protrudes significantly from the surface, cooling may be performed on all eight sides.

Increasing the frequency of the high-frequency alternating magnetic field also increases the heating effect caused by eddy currents. At this time, it is thought that eddy currents are concentrated near the conductor surface due to the skin effect.

That is, if the lesion is located deep within the human body, applying a lofty @ foundation may not be able to generate heat or IJIL in the lesion. However, at frequencies below 100 MH2, the skin effect can be almost ignored.

The cooling effect of blood flow is a factor that prevents the flow of water inside the body, but ignoring ζi, the 9 from the epidermis is 0.05.
The external magnetic field Bo = 1 mT is the time required to raise the temperature of the hot water in the lesion at point m by 5°C.

Specific heat 4.19X] OJ-K -g, density D=]
・0] gcm When calculated under the condition of 1 frequency of 50 MHz, it is approximately 770 mg. Therefore, even if there is a cooling effect due to blood flow, the formation of hot spots is sufficient. ! If the location of the lesion and the medical condition permit, temporary hemostasis can be used in combination with laser beams, laser beams, etc.

As is clear from the above, the non-therapeutic method does not use radiation or drugs, and therefore has extremely few side effects.

Therefore, it can be expected to be highly effective in heating cancer treatment inside the human body, which cannot be treated with lasers or microwaves.

Next, it is explained with reference to FIGS. 4 to 6 that the eddy current density in the region sandwiched between the first high frequency alternating magnetic field ubJ and the second high frequency alternating field aη becomes large.

Figures 4 and 5 show the 'FiL flow q! near the center of the square conductor plate marked with ±8 scales in the X-axis direction and the Y direction. Shows how to increase the j degree.

A two-dimensional conductor GL with uniform conductivity and magnetic infiltration rate is prepared as a conductor plate, and a uniform magnetic field HoY is applied to the whole. Also, C! of the two small areas indicated by diagonal lines in FIGS. 4 and 5! 41 In addition to the uniform magnetic field H0, IC also has a local fH
Immediately add the Kaima and the horses in the direction of the arrow group in Figure 5. That is, on one side, a local home field HA having the same phase as Ho is added, and on the other hand, a local group world 9 having an antiphase with Ho is added. To generate these local magnetic fields HA and HB, for example, air-core coils (four coils) are placed above and below the conductor plate, and these are used as a pair. This is the result of calculating the eddy electric current fN density on y@ of the conductor plate.Here, the local magnetic field HA, HBtr I HAI = IHBl
= a As IHol, find the eddy current density when a=1 and a=]0, and find the characteristic line 65VC! Result when 9a=10? The results in the case of a = ] are shown using the 1% sex line (g). As is clear from Fig. 6, the local magnetic fields HA, H
When the amplitude of B is small (i.e. a=1), the local Pk magnetic field H
The influence of A and HB is small, with 1! near the center y=0! If the amplitude of the local magnetic field HA ``B is large (i.e., the shadow 1 of the local magnetic field is thick at a = 103,
Two current loops gather near the center y=O, creating a large electric density? It turns out that you can get it too.

Accordingly, τ1 local research field HA, HB is high frequency 1! Because the flow changes depending on the direction of the current, it causes a large change in the magnetic field near y=O compared to the edge of the conductor plate, resulting in an increase in #l current. A so-called hot spot is formed.

Here, the uniform magnetic field HI was introduced to theoretically study the efficiency of eddy current generation depending on the magnitude of the amplitude of the F9rfB field, so it is not necessary in actual cases.

Since the local magnetic fields HA and HB correspond to the first and second high-frequency alternating magnetic fields ση in FIG. 1, the eddy current density in the region sandwiched by the first and second high-frequency alternating magnetic fields 11b1αη increases. That is clear. In Figure 1, it is necessary to heat the lesion B+21V inside the human body.

Even if FIG. 4 and FIG. 5 are applied to seven cases, it is impossible to heat the lesion (2). Therefore, heating is performed from multiple angles.

[Modified example]

The invention is not limited to the embodiments described above.

For example, the following modifications are possible.

(al　As shown in Figure 7, the Buddha's heart @ @ 21■ Beggar.

, :, 1m [:) Ill c111c (3 8 magnetic poles P1 to P may be formed.

(bl Multiple magnetic field generators (7) shown in Figure 1
Instead of providing the magnetic field generator (7), one magnetic field generator (7) may be rotated around the lesion (2) and a high frequency alternating magnetic field may be applied from an angular position in the morning. That is, after generating the first and second high-frequency alternating magnetic fields with a single magnetic field generator, the third and fourth high-frequency alternating magnetic fields, and then the MIJ
The fifth and sixth high frequency alternating magnetic fields may be generated.

(cl The 5th to 8th m poles Ps S in Fig. 3
The PsO strength is further strengthened, and the a east [magnetic field line] moves to the lesion area (2
) may be embedded in a U-shape in the vicinity 1.

rdl matrilineal P, corresponding to the size of the lesion +21;
and P.

The interval between hPt and Pl may be adjustable. Alternatively, the high frequency alternating magnetic fields of the first and bacteria 2 may be obtained without arranging the a-poles P, P, and Pj and P4 facing each other.

〔Effect of the invention〕

As is clear from the above, according to the present invention, a local area inside a three-dimensional object can be easily heated.

Therefore, it is extremely useful for heat treatment of cancer, etc.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a local heating device according to an embodiment of the present invention. FIG. 2 is a side view showing a part of line 11-U in FIG. 1. FIG. 3 is a plan view showing the magnetic field generator of FIG. 1 in more detail. The fourth factor is a plan view showing the relationship between the conductor plate and the field of station P9r for finding the density of eddy current in the two-dimensional conductor plate. FIG. 5 is an MT plane view on the y-axis of FIG. 4. FIG. 6) A diagram showing the relationship between the 'l 4' ll stop position of the conductor plate in FIG. 4 and the #I current density. FIG. 7 is a plan view showing the l-field generator Y of Hennosugi's example. (11...human body, (2)...cancer lesion, (3+
(4115+(61... virtual straight line, (7) (8) (9
)αQ...magnetic field generator, qυ...first coil. J...Second coil, αJ...Third fill, ■)
...Fourth coil, a...power supply, (IbI...
A first high frequency alternating magnetic field. 071...Second high frequency alternating S field, a81...Fifth
Phil. a9...6th fill, (2I...7th fill,
QD... 8th coil. Agent Nori Takano Figure 1 BA tJ2 Figure 7 Figure 4 Figure 5 Figure 6 y Main entrance 3L Good L placement

Claims (7)

[Claims] (1) A method of heating a local area within a conductive object, in which a first high-frequency alternating magnetic field whose center is on one side with respect to the center of the local area and is set to penetrate the object is applied. At the same time, a second high-frequency alternating magnetic field is generated, the center of which is located on the other side with respect to the local center, is set to penetrate the object, and has a phase difference with respect to the first high-frequency alternating magnetic field. generating a high frequency alternating magnetic field, thereby generating an eddy current in the object;
and third and fourth high frequency alternating magnetic fields having substantially the same mutual relationship as the second high frequency alternating magnetic field, the angular positional relationship with respect to the local area being different from the first and second high frequency alternating magnetic fields. 1. A method of local heating within a conductive object, the method comprising: generating an eddy current in the object, thereby generating an eddy current within the object. (2) The conductive material according to claim 1, wherein the third and fourth high-frequency alternating magnetic fields are generated with a time difference with respect to the first and second high-frequency alternating magnetic fields. Local heating method within the body. (3) The local heating method within a conductive object according to claim 1, wherein the phase difference is a phase difference that has an inverse phase relationship. (4) The first and second high-frequency alternating magnetic fields are alternating magnetic fields having a frequency of 10^5 Hz or more.
Local heating method within a conductive object as described in . (5) The local heating method within a conductive object according to claim 1, wherein the conductive object is a human body and the local area is a cancer lesion. (6) A device for heating a local area within a conductive object, comprising a plurality of high frequency alternating magnetic field generating devices provided corresponding to a plurality of virtual straight lines passing through the local area, the high frequency alternating magnetic field generating device: The high-frequency alternating magnetic field generator is configured to generate a high-frequency alternating magnetic field for causing an eddy current to flow in the object, and the high-frequency alternating magnetic field generating device has a first magnetic field of a first polarity.
a second magnetic pole of a second polarity, a third magnetic pole of the first polarity, a fourth magnetic pole of the second polarity, a fifth magnetic pole of the first polarity, and a second magnetic pole of the first polarity. a sixth magnetic pole having a polarity of , a seventh magnetic pole having a second polarity, and an eighth magnetic pole having a first polarity, and the first magnetic pole is located on one side of the object. The second magnetic pole is arranged along the straight line on the other side of the object, and a first magnetic pole is disposed along the straight line on the other side of the object, and a first magnetic pole is disposed along the straight line on the other side of the object.
is arranged opposite to the first magnetic pole to generate a high-frequency alternating magnetic field, the third magnetic pole is arranged along the straight line on the other side of the object, and the fourth magnetic pole is arranged along the straight line on the other side of the object. a second magnetic pole disposed along the straight line on one side and between the third magnetic pole and the third magnetic pole;
are arranged to face the third magnetic pole in order to generate a high-frequency alternating magnetic field, and the fifth and sixth magnetic poles are arranged between the first magnetic pole and the fourth magnetic pole, and the fifth and sixth magnetic poles are arranged between the first and fourth magnetic poles. The seventh and eighth magnetic poles are arranged between the second magnetic pole and the third magnetic pole. and is set to generate a high frequency alternating magnetic field for limiting the spread of the first and second high frequency alternating magnetic fields, and by sequentially operating the plurality of high frequency alternating magnetic field generators, the plurality of virtual straight lines are A local heating device in a conductive object, characterized in that it is configured to heat the local area corresponding to an intersection. (7) The high frequency alternating magnetic field for preventing the spread is:
7. The local heating device in a conductive object according to claim 6, which is generated in synchronization with the first and second high-frequency alternating magnetic fields.