JPH06190059A - Power source for high frequency thermal therapy - Google Patents

Abstract

PURPOSE:To achieve a heating of an affected part alone while expanding a heating area by setting a thickness of an insulation member thinner sequentially to the tip from the base end thereof in an applicator electrode comprising a needle-shaped conductor for application of a high frequency to an organism and the insulation member interposed between the needle-shaped conductor and the organism. CONSTITUTION:In an applicator electrode 1 which comprises a needle-shaped conductor 2 for application of a high frequency to an organism and an insulation member 3 interposed between the needle-shaped conductor 2 and the organism, the thickness of the insulation member 3 is set thinner sequentially toward the tip from a base end. As a result, an insulation capacity of a part requiring no heating can be increased to allow the lowering of heating of the non-heating required part thereby enabling local heating safely and effectively. This also allows minimizing of a rise in the temperature of the non-heating required part to achieve a lowering of increase in the amount of undesired blood stream thereby enabling effective local heating. Moreover, the power consumption of the non-heating required part is reduced thereby achieving effective consumption of applied power at an affected part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a therapeutic electrode (applicator electrode) for a high frequency thermotherapy device.

[0002]

2. Description of the Related Art So-called dielectric hyperthermia treatment for treating an affected area such as cancer by applying a high frequency electric field is roughly divided into two non-invasive flat plate type applicator electrodes 61 and 62 as shown in FIG. And a method of treating a cancer tissue by locally heating a part 64 of the living body 63 including the affected part by applying a high frequency between the applicator electrodes 61 and 62 on the body surface of the living body 63. 8, a rod-shaped applicator electrode 71 is inserted into the cavity of the rectum, which is called an intracavitary heating method, and a high frequency wave is generated between the applicator electrode 72 and another applicator electrode 72 mounted on the body surface. Is applied to heat the periphery of the applicator electrode 71 inserted into the cavity.

As a method of more actively performing local heating represented by the above-mentioned intracavity heating method, as shown in FIG. 9, a needle-shaped invasive therapeutic applicator electrode 81 is attached to an affected area 84 of a living body 83. Treatment to treat cancer tissue by locally heating the affected area 84 by inserting a high frequency wave between it and another applicator electrode 82 attached to the body surface. There is a law. This needle-shaped applicator electrode 8
As shown in FIG. 11, 1 has a constant diameter, and the needle-shaped conductor is covered with an insulating member.

The intracavity heating method and the tissue heating method realize local heating by obtaining the concentration of electric force lines around the in-vivo applicator electrode due to the difference in area between both applicator electrodes in combination. Is what you are trying to do.

[0005]

In the tissue heating method in which a needle-shaped applicator electrode is used in a living body, conventionally, there is almost no cooling of the electrode due to the limitation of the electrode diameter and the like. Since the lines of electric force are remarkably concentrated, as shown in FIG. 10, a hot spot 85 is generated in the vicinity of the in-vivo electrode applicator electrode 81, and heating is performed over the entire biopsy insertion portion of the applicator electrode 81. To be done. That is,
The heating range was limited to an extremely narrow region near the in-vivo applicator electrode, and it was necessary to use many electrodes to expand the heating region. Further, since the entire area near the applicator electrode is heated, there is a problem in that the normal tissue part other than the affected part is also heated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electrode for high-frequency hyperthermia treatment which can heat only an affected area and can widen a heated area.

[0007]

An electrode for high-frequency hyperthermia treatment according to claim 1 of the present application is a needle-shaped conductor for applying a high frequency to a living body, and an insulation interposed between the needle-shaped conductor and the living body. And a member, the wall thickness of the insulating member is changed and set from one end to the other end of the needle-shaped conductor.

In this high-frequency hyperthermia treatment electrode, for example, the thickness of the insulating member at the base end is increased, and the thickness of the insulating member is decreased toward the distal end, thereby making a difference in the current distribution of the electrodes. It is possible to reduce the heating of the heating unnecessary portion at the base end due to the thick insulation, and effectively heat the heating required portion at the tip. The high-frequency hyperthermia treatment electrode according to claim 2, comprising: a needle-shaped conductor for applying a high-frequency wave to a living body, and an insulating member interposed between the needle-shaped conductor and the living body. The thickness is changed and set from one end of the needle-shaped conductor to the other end, and a cooling path is provided in parallel with the needle-shaped conductor.

In this high-frequency hyperthermia treatment electrode, for example, the thickness of the insulating member at the base end is increased, and the thickness of the insulating member is made thinner toward the distal end, thereby heating the unheated portion of the base end. Is reduced due to the thick insulation and is cooled by the cooling unit, so that the heating of the unnecessary heating portion is reduced. The high-frequency thermotherapy electrode according to claim 3 is the electrode for high-frequency thermotherapy comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body. The needle-shaped conductor is a tubular body, and a cooling path is formed in the tubular body.

Since this high-frequency thermotherapy electrode forms a cooling path in the needle-shaped electrode, the cooling medium does not exist in the high-frequency passage portion, so that the impedance characteristic of the cooling medium affects the heating characteristic. Instead, for example, the cooling medium can be a high-impedance gas, and the insulation between the electrode and the cooling medium can be ideal. The high-frequency thermotherapy electrode according to claim 4 is the high-frequency thermotherapy electrode comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body. A part of the insulating member is removed and the needle-shaped conductor is exposed and set.

In this high-frequency thermotherapy electrode, a part of the insulating member, for example, the tip of the insulating member is removed to expose only the tip of the needle-shaped conductor, and the characteristics of the insulating member and the exposed portion of the needle-shaped conductor. By increasing the difference, only the exposed portion of the needle-shaped conductor is used as an effective electrode. That is, the heating is not performed on the portions other than the exposed portion, and the heating range and the heating portion can be freely set by appropriately changing the length of the exposed portion and the exposed portion. This electrode is suitable for the purpose of completely limiting the effective electrode in the case of being inserted into a living body, since the heated region becomes clear as compared with the electrode according to claim 1.

[0012]

The present invention will be described in more detail with reference to the following examples. FIG. 1 is a view showing a needle-shaped applicator electrode (high-frequency thermotherapy electrode) showing an embodiment of the present invention. The applicator electrode 1 of this embodiment is composed of a needle-shaped conductor (needle-shaped electrode) 2 and a catheter 3, and the catheter 3 has a taper shape that becomes thinner toward the tip,
It is composed of an insulating member, and as shown in the sectional view of FIG. 2, a tubular portion 4 having a constant diameter is formed inside. When the applicator electrode 1 is used, the one in which the needle-shaped conductor 2 is attached to this cylindrical portion 4 is used.

This applicator electrode 1 is shown in FIGS.
When used in a state similar to that shown in, the thickness of the catheter 3 is thicker toward the base of the applicator electrode 1 and thinner toward the tip, so that electric field concentration due to the needle-shaped electrode 2 does not occur toward the base. Therefore, heating is reduced and no heating spot is generated. That is, in the applicator electrode of this embodiment, it is possible to limit the effective electrode portion of the applicator electrode that is inserted into the living body.

FIG. 3 is a view showing a needle-shaped applicator electrode showing another embodiment of the present invention. The applicator electrode 11 of this embodiment also comprises a needle-shaped conductor (needle-shaped electrode) 12 and a catheter 13, and the catheter 13
4, a tubular portion 14 having a constant diameter is formed inside as shown in FIG. 4, and these points are the same as those shown in FIG.

The feature of the applicator electrode 11 of this embodiment is that the wall thickness of the catheter 13 is not tapered, that is, not continuously changed, but the wall thickness is gradually reduced from the base end to the tip. There is a point. According to the applicator electrode 11, the thickness of the catheter 13 is gradually increased,
Since it is extremely changed, it is possible to further increase the difference in heat generation between the heated portion and the non-heated portion. Further, this stepped catheter can be easily produced by combining catheter tubes having different thicknesses, and an optimal therapeutic applicator electrode can be produced for each affected area. Of course, the catheter shown in FIG. 1 or FIG. 3 is different in taper degree, the number of steps, the degree, etc. are variously prepared, so that the optimal treatment according to the affected area is performed. be able to.

As described above, the fact that the applicator electrode can be prepared according to the affected area is important in local heating, and more reliable local heating can be realized. Furthermore, as another embodiment, the needle-shaped conductors 2 and 12 shown in FIGS.
The insulating material may be coated on itself and the shape of the insulating material may be tapered or stepped as shown in FIG. 2 or FIG. This makes it possible to achieve heating in the local tissue without using a catheter.

In this embodiment, by insulating the electrode itself, it is possible to avoid abnormal heating due to poor contact between the catheter and the electrode (intervening air or the like) when the catheter is used. It is considered that abnormal heating due to poor adhesion is very likely to occur when a catheter or the like is used, and avoiding this hot spot means that more stable local heating is realized.

FIG. 5 is a sectional view showing still another embodiment of the present invention. FIG. 5 (a) is an axial sectional view.
5B is a cross-sectional view taken along the line AA of FIG.
As described above, in the configuration of the applicator electrode having the insulating region stepwise, by making it possible to cool the electrode used, it is possible to further reduce hot spots due to the concentration of lines of electric force in the vicinity of the applicator electrode, The heating area can be expanded.

That is, it becomes possible to selectively avoid the hot spot near the electrodes even in the affected area. In general, flat plate type and intracavity electrode applicators were cooled by having a cooling layer between the surface of the internal electrode and the living body, but in such a configuration, the cooling medium exists in the high frequency passage part. Therefore, if the impedance of the cooling medium is high, the cooling medium itself causes power loss.

Further, since the needle-shaped electrode has no cooling passage,
As described above, the heating region is concentrated near the electrodes. This embodiment applicator electrode solves these problems. That is, the embodiment shown in FIG. 5 is intended to realize cooling of a small-diameter needle-shaped applicator electrode.

The applicator electrode 21 has an insulating coating 2
3, a pair of metal pipes 22a and 22b are provided, and these pipes 22a and 22b also serve as electrodes and are used as cooling pipes. Although not shown, the insulation coating 23
Are appropriately formed in steps. A metal hollow pipe or the like is used as an electrode, and the cooling medium is cooled from the inside by passing through the pipe.

According to the structure of this embodiment, as compared with the conventional applicator electrode having a cooling layer between the electrode surface and the living body, the cooling layer is provided only on the inner side of the electrode, so that the cooling layer on the electrode surface is formed. The outer diameter of the final finish of the applicator electrode can be reduced by the amount that does not exist. However, in the needle-shaped applicator electrode, as a matter of course, it is necessary to use a pipe having a small diameter, and in order to secure the flow rate of the cooling medium, it is necessary to circulate the cooling medium at high pressure.

However, according to the structure of this embodiment, since the cooling medium does not exist in the high frequency passage portion, the impedance characteristic of the cooling medium does not affect the heating efficiency at all. Therefore, compressed gas or the like can be used as the cooling medium. In general, gas has a high impedance, so that ideal insulation between the electrode and the cooling medium can be obtained.

Further, since the gas can be used as a cooling medium, it is possible to avoid liquid leakage when a liquid such as cooling water is used and an increase in the weight of the applicator electrode due to the use of the liquid. . FIG. 6 is a schematic diagram of a high-frequency thermotherapy device realized by using the applicator electrode 21 of FIG. Here, compressed air is used as a cooling medium, and compressed air from the clean unit 26 of the main body 25 is supplied to valves V ₁ , ..., V ₉ provided on individual supply paths 27 _-1 , ..., 27 _-9. It is turned ON / OFF by the valve, and the temperature of the applicator electrodes 21 _-1 , ..., 21 _-9 can be finely adjusted by adjusting the ON / OFF timing of the valves V ₁ , ..., V ₉ . According to this, the temperature of the applicator electrode can be controlled by cooling at a constant temperature.

FIG. 7 is an axial sectional view showing still another embodiment of the present invention. The applicator electrode 31 is similar to the embodiment shown in FIG. 2 in that it is composed of a needle-shaped conductor (needle-shaped electrode) 32 and a catheter (insulating member) 33, but the tip of the catheter 33 is removed. The feature is that the tip end portion 32a of the needle electrode 32 is exposed. As a result, heating is not performed in the portion of the needle electrode 32 covered with the catheter 33, and only the tip portion 32a becomes the effective electrode, so that the electric field can be concentrated on the tip portion 32a. In addition to this, by changing the length of the exposed portion of the needle electrode 32 or changing the removed portion of the catheter 33, it is possible to freely set the heating range and heating region.

[0026]

According to the invention described in claim 1 of this application, since the insulating member of which thickness gradually changes is interposed between the needle-shaped electrode and the living body, the insulating capacity of the heating unnecessary portion is increased. By doing so, the heating of the heating unnecessary portion can be reduced, and safe and effective local heating can be performed. Since the temperature rise of the heating unnecessary portion can be reduced, the increase of the unnecessary blood flow can be suppressed, and the effective local heating can be performed. Since the power consumption of the heating unnecessary portion is reduced, the applied power is effectively consumed in the affected area, and efficient heating can be performed. When a tube such as a catheter is used to secure the insulating region, the same electrode can be used for different heating sites by changing it.

Further, according to the invention of claim 2, since the cooling path is further provided in parallel with the needle-shaped conductor, in addition to the effects of the above-mentioned items 1 to 3, the needle-shaped conductor is provided. It is possible to suppress heating in the vicinity of the electrodes and perform appropriate heating only on the affected area. According to the third aspect of the invention, since the needle-shaped conductor is formed into a tubular body and the cooling passage is formed in the tubular body, it is provided between the internal electrode and the living body like a conventional intracavity applicator. Since there is no cooling layer, a small-diameter applicator electrode can be configured, and the burden on the patient at the time of insertion or insertion is reduced. Since the hot spots near the in-vivo electrodes can be removed by cooling, it is possible to expand the heating region, reduce the number of required electrodes, and reduce the burden on the patient. Since the cooling medium exists only inside the electrode, there is no change in heating efficiency due to the impedance characteristics of the cooling medium itself, and stable heating treatment can be performed. By using a high-impedance substance as the cooling medium, the insulation between the electrode and the cooling medium can be easily realized, and safe heating treatment can be achieved.

Further, according to the invention described in claim 4, since the needle-shaped conductor is exposed by removing a part of the insulating member,
Since the characteristic difference between the insulating member and the exposed portion of the needle-shaped conductor can be increased and substantially only the exposed portion can be used as an effective electrode, the heated portion becomes clearer than the electrode according to claim 1. . By changing the length of the exposed portion of the needle-shaped conductor and the removed portion of the insulating member, the heating range and heating region can be set freely, which is particularly suitable for the purpose of completely limiting the effective electrode.

[Brief description of drawings]

FIG. 1 is an explanatory view of an applicator electrode showing an embodiment of the present invention.

FIG. 2 is an axial sectional view of the applicator electrode of the same embodiment.

FIG. 3 is an explanatory view of an applicator electrode showing another embodiment of the present invention.

FIG. 4 is an axial cross-sectional view of the applicator electrode of the same embodiment.

FIG. 5 is a sectional view of an applicator electrode showing still another embodiment of the present invention.

FIG. 6 is a schematic view of a high-frequency thermotherapy device using the applicator electrode of the same embodiment.

FIG. 7 is an axial sectional view of an applicator electrode showing yet another embodiment of the present invention.

FIG. 8 is a diagram for explaining a conventional treatment using two flat plate type applicator electrodes.

FIG. 9 is an explanatory diagram illustrating a conventional intracavity heating method.

FIG. 10 is a diagram illustrating a conventional tissue heating method using a needle electrode.

FIG. 11 is an explanatory view showing a heating spot by the same tissue heating method.

FIG. 12 is an external view showing a conventional needle-shaped applicator electrode.

[Explanation of symbols]

 1 Applicator electrode 2 Needle-like conductor 3 Insulation member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriyuki Takahashi, 17 Nakadoji-Minami-cho, Shimogyo-ku, Kyoto Science Center Building, Omron Life Science Laboratory Co., Ltd. Scenter Building Co., Ltd. Omron Life Science Research Institute (72) Inventor Akinori Kato 17 Nakadoji Minami-cho, Shimogyo-ku, Kyoto Science Center Building Omron Life Science Research Institute

Claims (4)

[Claims] 1. A high-frequency thermotherapy electrode comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body, wherein the thickness of the insulating member is the needle. An electrode for high-frequency hyperthermia treatment, characterized in that the electrode is set by changing from one end of the conductor to the other end. 2. An electrode for high-frequency thermotherapy comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body, wherein the wall thickness of the insulating member is the needle. An electrode for high-frequency hyperthermia treatment, characterized in that it is changed and set from one end of the shaped conductor to the other end, and a cooling passage is provided in parallel with the needle shaped conductor. 3. A high-frequency thermotherapy electrode comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body, wherein the needle-shaped conductor is a tubular body. An electrode for high-frequency hyperthermia treatment, characterized in that a cooling passage is formed in the cylindrical body. 4. A high-frequency thermotherapy electrode comprising a needle-shaped conductor for applying a high frequency to a living body and an insulating member interposed between the needle-shaped conductor and the living body, wherein a part of the insulating member is removed, An electrode for high-frequency hyperthermia treatment, characterized in that the needle-shaped conductor is exposed and set.