JPS592501B2 - Applicator for warming the affected area in heat therapy - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an applicator for warming an affected area that is applied to heating therapy, and is capable of easily heating an affected area that exists deep inside a living body. .

By the way, if both the abnormal cell tissue that constitutes cancer or other tumor and the surrounding normal cell tissue are heated to a temperature range of 40°C or higher, only the former will rise to a temperature 2 to 2.5°C higher than the latter. It is well known that high temperatures can occur.

Therefore, in recent years, care has been taken to keep normal cell tissues within a temperature range of 43 degrees Celsius or below, where they will not be affected by necrosis, etc., and by heating the affected area and its surroundings, only abnormal cell tissues can be removed. A method of raising the temperature to around 45°C to cause necrosis and cure cancerous and other affected areas is attracting attention as so-called hyperthermia therapy, and its effectiveness is being confirmed clinically. . Various methods have been conventionally proposed for heating the affected area when performing such heating therapy, depending on the location of the affected area.

For example, attempts have been made to treat skin cancer by warming the affected area with an incandescent lamp, and to treat bladder cancer, heating the affected area with warm water injected into the bladder. However, all of these heating methods place the heating source directly near the affected area.
Because it is a device that touches or attempts to bring into contact, it cannot be applied unless the affected area is in a specific location, and it is more common to be unable to inject a heating source even if it is deep inside the body. It cannot be said to be an appropriate method for many other affected areas. Therefore, attempts have been made to use dielectric heating within a high-frequency electric field to heat the affected area located deep inside the living body.

This method attempts to heat the affected area by dielectric heating by supplying high-frequency power between a pair of electrode bodies attached to the surface of the living body so as to sandwich the affected area from both sides. Even if the affected area is located deep within the body, heating is possible. However, in this heating method, the required frequency of the high-frequency power to be supplied is high, for example, 13.
Since the frequency is about 56 MHz, various complicated problems tend to occur regarding impedance matching between the high frequency generation source and the electrode body, and between the electrode body and the living body. In addition, with this heating method, the electrode body must be brought into close contact with the surface of the living body in order to avoid a low electric field strength T due to the air gap between the electrode body and the living body, making it difficult to handle the electrode body during treatment. However, depending on the location of the affected area, it may be difficult to place the electrode body in close contact with the optimal location, and the affected area may not be heated as desired, so the applicable range may be unexpectedly wide. narrow. The present invention aims to utilize induction heating based on electromagnetic induction in order to easily heat the affected area located deep inside the living body in order to cope with the conventional situation as described above. It is something to do.

A coil, also called an inductor, is used for such induction heating, and heating methods using this are roughly classified into the following three types depending on how the coil is used. In other words, the first ten thousand expressions are the first
As shown in FIG. 1, the heated object 2 is placed inside the coil 1, and the second method is as shown in FIG. 2, in which the coil 1 is placed inside the heated object 2. In the third method, as shown in FIG. 3, the end face of the coil 1 is opposed to the object to be heated 2. However, the effectiveness of induction heating by the coil described above decreases as it approaches the center line of the coil perpendicular to the end face of the coil, and becomes zero on the center line. Therefore, with the first heating method described above, it is possible to hardly or not warm the affected area located deep inside the living body, and with the second heating method, the insertion of the coil into the inside of the living body itself is difficult. Because of this, it is virtually impossible to heat the affected area using the coil.Furthermore, in the third heating method, the heating range is donut-shaped, making it difficult to efficiently heat the affected area at a deep location. Therefore, the present inventors focused on what can be called a fourth induction heating method in order to easily warm the affected area located deep inside the living body.

In other words, in this method, a part of the outer circumferential surface of the coil is used as a heating surface, and this surface is brought close to or in contact with a part of the body's surface as close as possible to the affected area deep inside, and when a high-frequency current is passed through the coil, the above-mentioned heating is achieved. The idea is to use induced current induced outside the surface to warm the affected area. The present invention was made with the intention of developing an applicator for warming an affected area suitable for use in this manner.

The applicator for warming an affected area provided by the present invention is characterized in that the shape of the opening end surface is rectangular, and the number of turns with a certain width in the direction perpendicular to the end surface is 1 to 1. It consists of two or more single-layer coils, and the outer peripheral surface corresponding to the short side of the rectangular open end surface is used as a heating surface, and this surface is brought into contact with the surface of the living body. Therefore, according to the present invention, the heating surface of the applicator is
By applying a high-frequency current to the coil constituting the applicator while placing it in contact with the surface of the living body as close as possible to the affected area deep inside, the induced current induced outward from the heating surface is directed to the affected area. This makes it possible to easily warm the affected area deep inside the living body from outside the living body.

The present invention will be explained in detail below, and it will be made clear that the above-mentioned effects can be expected together with other effects. First, referring to FIG. 2, FIG. 1 shows a first embodiment of an applicator 10 for warming an affected area according to the present invention, and FIG. 2 shows a second embodiment of the same.

This applicator 10 basically consists of only a coil 11, which is connected to a suitable power source capable of supplying the required alternating current. However, the above-mentioned coil 11 has a single layer structure with the number of turns of 1 or 2 or more,
Therefore, FIG. 1 shows a coil with 1 turns, and FIG. 2 shows a coil with 7 turns. In any case, this coil 11 is formed so that the open end surface 12 is rectangular in shape, and has a certain width along the coil center line row 0 in the direction perpendicular to the end surface 12. For this reason, in the first embodiment in which a coil with one turn is used, the coil is formed of a strip-shaped conductive material in order to ensure the above-mentioned width. In the coil 11, the outer circumferential surface 13 of the portion corresponding to the short side of the rectangular open end shape is a heating surface that comes into contact with the object to be heated. Note that FIG. 2 and 3 show a third embodiment of the applicator 10, and the coil 11 used in this embodiment has an open end surface 1.
On the condition that the shape of heating surface 13 is rectangular,
is curved so as to form a part of the inner surface of the cylinder, so that the overall planar shape is formed so as to spread out in a fan shape toward the opposite side of the heating surface 13. Next, in FIG. 3, FIG. 1 shows a first usage example of the affected area warming applicator according to the present invention, FIG. 2 shows a second usage example, and FIG. 3 shows a third usage example.
Examples of their use are shown. That is, in the usage example of FIG. 1, one applicator 10 is used for the living body 21, which is the object to be heated, and in the usage example of FIG. 2, two applicators 101 and one mouth 2 are used. In the usage example of FIG. 3, six applicators 101 to 101 are used as an example of three or more applicators.
106 are used. In any case, the applicators 10, 10, 102 used in each of these use cases
1 to 101 to 106 are the heating surfaces 13 of the coils 11, which are brought into contact with the surface of the living body 21 in which the affected part 22 exists deep inside. The applicator is brought into contact with or in close proximity to the surface of the living body 21, with the heating surface 13 brought as close as possible to the affected area 22 inside the living body. is desirable. Therefore, one applicator 10 used in the example of use in FIG. 1 is placed at a convenient location to approach the affected area 22, and two
The base applicators 101 and 1 mouth 2 are arranged facing each other so as to sandwich the affected area 22 from both sides, and the six applicators 10, to 106 used in the usage example of FIG.
They are arranged in a radial direction so as to surround the area.
Note that in each usage example shown in FIG. 3 above, the second
It is assumed that the applicator shown in FIG. 1 or 2 is used.

However, since the heating surface 13 of each of these applicators has a planar shape, it is difficult to apply the heating surface 13 to the surface of the living body 21. Therefore, especially in the usage example of FIG. 3 1 where only one applicator is used, , there is a concern that it is difficult to concentrate energy on the affected area 22. Therefore, in such a case, Fig. 2 3
When the applicator shown in 1 is used, the curved heating surface 13 of the applicator can be easily applied to the surface of the living body 21, and the above-mentioned concerns can therefore be resolved. Regarding the present invention configured as described above, the mechanism of warming the affected area will be explained next. For example, in the coil 11 of the applicator 10 shown in FIG. Assume that the width in the direction is b. If a high-frequency current of E per unit width is passed through the coil 11, the current I is . From the effective current e, frequency f and time t, I=,F
2Iesin2πFt・・・・・・・・・・・・・・・
...It is determined by the formula (1).

In addition, the vector potential A at a point P that is a distance r away from the minute area element Ds on the heating surface 13 can be expressed as the sum of the vector potentials due to the area element Ds, and the dielectric constant εo in vacuum and the speed of light c using A
= Life Chi ÷ Ds (2) It is determined by the formula.

However, when the vector potential A at point P changes over time, at that point P, DA E= 1 - ・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・(3) An electric field Dt is generated.

The strength E of this electric field can be further expressed as E=-4.0C2J÷Ds (4) using the above equations (2) and (3).

When the heating surface 13 of the coil 11 is brought into contact with a heated object having a conductivity σ and a high-frequency current having a frequency f is passed through the coil, the heating surface 13 of the heating surface 13 is heated. Heat is generated due to the action of the induced current induced outward.

At this time, the calorific value w per unit volume of the heated object is, assuming that the current flows uniformly within the coil 11, and if the above σ and f are small, Ds W = 4π2σF2Ie × 10- 14×[-]2...
...゜(5) It can be approximately determined by the formula r.

Therefore, the long side length h of the rectangular opening end face 12 is 60 (
V7! , the short side length a is 20 cm) and the width b of the heating surface 13 in the direction of the coil center line is 20 (V7!).
A coil 11 having the shape shown in FIG. 1 is prepared, and as shown in FIG. If a high frequency current of f = 1 MHz, Ie = IA/m is applied to
The calorific value w per unit can be calculated by the above equation (5) assuming that σ=0.6Ω/m.

Based on the results calculated in this way, the state of distribution of the calorific value within the living body 21 is illustrated as shown in FIG. 4.

This figure shows the coordinate components from the center of the heating surface 13 in the Z-axis direction perpendicular to the surface, Z=1c7n)3C7n)5c-! R
L)7cm)9CrrL)11C7n, and the Y-axis direction coordinate component Y(
V7! It shows the relationship between and the calorific value w/1. According to this figure, in each section in the Z-axis direction, Y
The smaller the axial coordinate component, that is, the closer to the Z-axis, the greater the amount of heat generated. This means that the energy for warming the living body 21 is supplied to the living body 21 while converging along the Z-axis to a certain extent, and is applied to a limited area of the living body, that is, the affected area 22. Convenient for heating. In such directivity, the applicator shown in FIG. 3 is better than the applicator shown in FIGS. 1 and 2. Also, according to FIG. 4, as a matter of course, the amount of heat generated decreases as the coordinate component in the z-axis direction increases.

However, even at the coordinate position Z=1IC-IrL, the amount of heat generated is still 17.4% of that at the coordinate position Z=1(V7!). Therefore, for example,
The heating surface 13 of the applicator 10 is placed 1 from the surface of the living body 21.
When C7rL is separated and faced, the depth inside the living body is 10 (
Even at V7l, it will still be heated with a calorific value of more than 17% as described above. Therefore, even in the usage example shown in FIG. 3 1 in which only one applicator 10 is used, the area shallower than the affected area 22 that exists deep inside the living body 21 must be cooled by some means or the affected area By rotating the applicator 10 around the living body 21 around the body 22, it is possible to heat only the affected area 22 to the required temperature while preventing excessive heating of areas other than the affected area. However, it cannot be denied that using only one applicator 10 is insufficient to sufficiently warm the affected area 22 deep inside the living body. Therefore, the usage example shown in FIG. 31 is rather suitable for heating an affected area located in a relatively shallow area deep inside a living body. Therefore, when trying to warm an affected area that is relatively deep inside the living body, for example, near the center of the living body, two applicators 101 and 102 are used as shown in FIG. An example of use in which the devices are used facing each other is suitable.

That is, the relationship between the electric field strength E and the amount of heat generated per unit volume w is w=σE2...
・・・・・・・・・・・・・・・(6) There is a relationship,
It is known that when the former increases, the latter increases in proportion to its square. Thus, for example, a diameter of 20C-!
When the affected area 22 is at the center of the living body 21 in TL, the two applicators 101 and 102 are applied 1c7r each from the living body surface.
If the affected area is placed at a depth of 10L (V7L) and the affected area is placed facing each other with a distance of L, the amount of heat generated at the affected area at a depth of 10V (V7l) will be equal to that on the surface of the living body when only one applicator is used. What was 17.4% is twice this,
In other words, it reaches 69.6%, and therefore heating of the affected area 22 becomes much easier than in the usage example shown in FIG. 31. Similarly, six applicators 101 to 1 are installed as shown in FIG.
When using 06, the amount of heat generated at the affected area 22 is 17.4%
It is strengthened to 62 times, that is, 626.4%, and therefore heating of the affected area 22 becomes easier. However, in this usage example, if all the applicators are operated at the same time, the affected area 22 may be heated too much in view of the above heat generation ratio. Therefore, all applicators 101~
106 facing each other, namely 101, 104, and 10
Divide into three groups consisting of 2 and 105 and 103 and 106 and operate each group sequentially, or
If the two groups are divided into 01, 103, and 105, and 102, 104, and 106, and the two groups are operated alternately, only the affected area 22 will be heated continuously, while the other parts will be heated. can only be heated intermittently, thus making it easy to sufficiently heat the affected area 22, and preventing excessive heating of other areas, as shown in Figure 3.1. There is no need for protective means such as cooling the surface layer of the living body or rotating the applicator as described above in the usage example. On the other hand, applicator 1
0 shape, especially the short side length a at the rectangular opening end surface 12
The ratio of the long side length h of the filter to the area of the heating surface 13 is:
Each has a large impact on heating performance. First, if we look at the effect of the long side length, we will see the effect shown in Figure 5.

In other words, this figure shows the amount of heat generated w that changes depending on the coordinate component in the Z-axis direction for several types of applicators with different long side lengths h.
is expressed in % based on Z = IC-1rL. In this figure, curve 1 is h = 80C-! TL)
2 is h = 60 cm) 3 is h = 40 cm, 4 is h = 20 (
V7l,5 indicates the equality of each applicator, h=10-. However, the dimensions a x b of the heating surface of each applicator shall be 20cm x 20crrL. As is clear from this figure, the heating performance of the applicator is better as the long side length h of the opening end surface is longer than the short side length a. However, there is not much difference between curves 1 and 2. Therefore, considering that the smaller the overall size is, the easier it is to handle, the long side length h of the opening end surface
It can be said that an applicator with a ratio of 3:1 to short side length a is the most practical. Next, if we look at the influence of the area of the heating surface, we can see the effect as shown in Figure 6.

That is, this figure shows the amount of heat generated w, which changes depending on the coordinate component in the z-axis direction, in % with respect to Z=1cTrL for several types of applicators with different heating surface areas a×b. However, it is assumed that the above-mentioned ratio of h to a of 3:1 is maintained for all applicators. In this figure, the applicator dimensions AXbXh corresponding to each curve are 20 x 20 x 6 for curve 1.
16 x 16 x 48 for 0 and 2, 12 x 12 x 36 for 3
, 4 is 8×8×24, and 5 is 5×5×15 (all units are CTrL). As is clear from this figure, the heating performance of the applicator is better as the heating surface area becomes larger. However, if we consider the cross-sectional area of the living body to be heated, and also consider ease of handling as in the case of the long side length h, the dimensions of the heating surface are 20 cTn.
×20 (approximately 7n) is the limit. As explained above, according to the present invention, the following effects can be expected.

First of all, generally speaking, when trying to heat the inside of a living body, it is better to use induction heating than to use dielectric heating, without heating the fat layer and bone tissue that have high impedance. In addition, each part of the living body, including the head and chest, can be easily heated without being obstructed by air-containing tissues or cavities, and the heating applicator can be heated with lower frequency power. Since the applicator can be driven, there is an advantage that the electrical drive system of the applicator can be simplified. However, the present invention uses an applicator consisting of a single-layer coil having a rectangular opening end face and a certain width in a direction perpendicular to the end face, and having one or more turns. The outer circumferential surface corresponding to the short side of the opening end face is used as a heating surface and is brought into contact with the surface of the living body, and the induced current induced outside the heating surface is made to act inside the living body. Therefore, according to the present invention, while making full use of the above-mentioned advantages of induction heating, it is possible to treat the affected area deep inside the living body in a manner better than the conventional example shown in FIGS. 1, 2, and 3 above. In addition, the applicator of the present invention makes it easier to concentrate heating energy on the affected area than the inductor used in the conventional examples. The affected area can be heated efficiently.

Further, according to the present invention, since it is not necessary to bring the applicator into particular contact with the living body surface, the applicator can be easily handled during treatment, and by adjusting the distance of the applicator from the living body surface, the applicator can be easily handled during treatment. The internal heating status of the affected area can be adjusted relatively easily from the outside.

Moreover, since the applicator according to the present invention is made of a coil with a simple structure, it is extremely easy to manufacture, and can be adjusted depending on the location and size of the affected area to be heated, the type of disease, the degree of deterioration, etc. An inductor with a size and shape suitable for these inductors can be easily prepared, and therefore has the advantage of a wider range of applicability than the conventional inductor.

[Brief explanation of the drawing]

1, 2, and 3 are perspective views showing conventional examples of induction heating; FIG. 2, 1, 2, and 3 are perspective views showing each embodiment of the present invention; and FIG. 3, 1, 2. , 3 are plan views showing respective usage examples of the applicator for warming an affected area according to the present invention, FIG. 4 is a graph showing the distribution state of calorific value inside a living body, and FIG. FIG. 6 is a graph showing the influence of the length of the long side of the opening end surface on the heating performance of an applicator for warming an affected area, and FIG. 6 is a graph showing the influence of the area of the heating surface on the heating performance. 10... Heating applicator, 11...
・Coil, 12... Open end surface, 13...
・Heating surface, 21... Living body, 22... Affected area, h... Long side length, a... Short side length, b...・・・Width.

Claims (1)

[Claims] 1. Consists of a coil through which a high-frequency current is passed, and this coil has a rectangular open end face, has a certain width in the direction of the coil center line perpendicular to the end face, and has 1 to 2 turns. The above-mentioned single-layer coil is characterized in that the outer peripheral surface of the coil corresponding to the short side of the rectangular opening end surface of this coil is used as the heating surface to be brought into contact with the surface of the living body. Applicator for heating the affected area in therapy. 2. The applicator for warming an affected area according to claim 1, wherein the ratio of the length of the long side to the length of the short side of the rectangular opening end face is 3:1. 3. Provided that the opening end surface is rectangular, the heating surface is curved so as to form a part of the inner surface of the cylinder, and the overall planar shape is formed so as to spread out in a fan shape toward the opposite side of the heating surface. The applicator for warming an affected area according to claim 1, characterized in that: