JP3349372B2 - Microwave surgical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave surgical device which coagulates and stops bleeding of a living tissue by using a microwave, and more particularly, it is used for surgical treatment such as clotting and hemostasis of a diseased tissue in a deep part of a living tissue. It relates to a microwave surgical instrument.

[0002]

2. Description of the Related Art Conventionally, when treating a diseased tissue in a deep part of a living body, a method of treating the living body by laparotomy to the deep part has been adopted. In this case, laparotomy of the living body involves many dangers such as bleeding. , The surgery is a big deal, and
The disadvantage is that postoperative recovery is prolonged.

[0003] As a method of performing treatment without laparotomy, there is a method of using biopsy forceps or the like. That is, a biopsy forceps or the like is inserted into a deep part of the body through a biopsy puncture mantle from outside the body, and surgical treatment is performed under laparoscopy or ultrasonic examination. However, in this case, although a predetermined treatment can be performed without laparotomy, it is extremely difficult to stop the puncture hole with a biopsy forceps or the like.

[0004] Therefore, Japanese Utility Model Publication No. 1-1934 (A)
61B 17/36) has been developed.

The surgical instrument comprises an elongated percutaneous deep-body surgical electrode supported by a connector connected to a microwave oscillating unit via a coaxial cable, and the surgical electrode is a tubular ground electrode serving as an outer conductor. And a tubular insulator provided at the core of the ground electrode and having a tip derived from the tip of the ground electrode, and a rod-shaped insulator provided at the core of the insulator and having a tip derived from the tip of the insulator. A center electrode is provided, and a microwave of 2450 MHz is irradiated from the tip of the center electrode.

[0006] Under ultrasonic examination, the distal end of the surgical electrode, in other words, the distal end of the central electrode is directly punctured from the surface of the skin outside the body or from the surface of the solid organ, thereby deepening the living tissue. When microwaves are inserted into the diseased tissue and irradiated with microwaves, a spindle-shaped microwave electric field is formed between the tip of the center electrode and the tip of the ground electrode. Due to the heat, the deep diseased tissue is stopped and coagulated to necrosis, and predetermined surgical treatment is performed.

[0007] Conventionally, SUS30 is used as the ground electrode.
4. Teflon is used for the insulator and phosphor bronze is used for the center electrode.

[0008]

In the case of the above-mentioned conventional microwave surgical device, when a microwave discharge is generated to cause necrosis of a diseased tissue due to dielectric heat, the surface temperature of the surgical electrode rises, and the puncture portion of the surgical electrode is increased. Since burns occur on the skin and the like, the skin must be cooled with cold water, ice chips, or the like, and there is a problem that the operation is complicated.

Also, the center electrode is elongated, and if the strength is weak, there is a problem that the center electrode in the portion between the ground electrode and the tip of the center electrode is broken.

[0010] Conventionally, any attempt to improve between the surface temperature of the surgical electrode, the bending strength of the surgical electrode, and the matching with the microwave of 2450 MHz causes a problem in other conditions. There is a point.

The present invention has been made in consideration of the above points, and has been made to reduce the surface temperature of a surgical electrode, increase the strength of the surgical electrode, and improve the impedance matching state, in addition to the conventional technique. The purpose is to provide.

[0012]

In order to solve the above-mentioned problems, a microwave surgical instrument according to the present invention is supported by a connector connected to a microwave oscillating unit via a coaxial cable,
What is claimed is: 1. A microwave surgical device comprising an elongated surgical electrode having a distal end inserted into a deep part of a living tissue, comprising: a tubular ground electrode serving as an outer conductor of the surgical electrode; A tubular insulator extending from the tip of the ground electrode, a rod-shaped center electrode provided at the core of the insulator, and having a tip derived from the tip of the insulator; and a tip of the center electrode. And a microwave irradiation unit having a sharp conical point formed at a tip thereof, wherein the center electrode is constituted by a rod-shaped center body and a center outer layer body on the outer periphery of the center body, The outer layer and the ground electrode are made of a metal having a lower electrical resistivity than the center, and the center is made of a metal having a higher hardness than the outer layer.

Therefore, when the distal end of the surgical electrode is inserted into the deep part of the living tissue, the conical point at the distal end of the microwave irradiating portion at the distal end of the center electrode is inserted into the diseased tissue. A microwave electric field is generated between the wave irradiator and the ground electrode, and the dielectric heat causes hemostasis and coagulation of the diseased tissue, necrosis, and surgical treatment is performed. At this time, since the center electrode is formed by the center body and the outer layer body, and the center outer layer body is formed of a metal having lower electric resistivity than the center body, the high frequency current of the microwave electric field is electrically Low heat generation by flowing through the center outer layer with good characteristics,
The surface temperature of the surgical electrode can be made lower than before to prevent a burn at the insertion portion of the surgical electrode. Moreover, since the center body is made of a metal having a higher hardness than the outer layer body,
The strength of the center electrode can be increased, as well as the impedance matching.

Next, the ground electrode is constituted by a cylinder and a ground outer layer on the outer periphery of the cylinder, and the ground outer layer is constituted by a metal having a lower electric resistivity than the cylinder.
The surface temperature can be further reduced by lowering the heat generated by the surgical electrode.

[0015] state, and are not formed by coating on the central body a central outer body, furthermore, the ground layer body also cylindrical
Ru der those formed by coating on the body.

Further, the outer center layer and the ground electrode ,
The layer body and the ground outer layer body are made of at least one of silver, copper, gold, aluminum, brass, nickel, tin and chromium.

[0017]

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

(Embodiment 1) In the front view of FIG. 1 and the cross-sectional view of FIG.
Reference numeral 1 denotes a connector, which is connected to a flexible coaxial cable connected to the microwave oscillating unit. Reference numeral 2 denotes a long and thin percutaneous surgical electrode for percutaneous deep in the body, which is supported by the connector 1 and penetrates the skin from outside the body and penetrates into a deep part of the living tissue. Reference numeral 3 denotes a tubular ground electrode serving as an external conductor of the surgical electrode 2. Is provided at the core of the ground electrode 3, the tip is a tubular microwave insulator derived from the tip of the ground electrode 3, 5 is provided at the core of the insulator 4, and the tip is the tip of the insulator 4. The rod-shaped central electrode 6 derived from the central electrode 5 is a microwave irradiating part fixed to the tip of the central electrode 5, and a sharp conical point 7 is formed at the tip. 2450 from part 6
A microwave of MHz is applied. Further, the center electrode 5 is composed of a rod-shaped center body 8 and a center outer layer body 9 on the outer periphery of the center body 8. The center body 8 is formed of a metal having a higher hardness than the center outer layer body 9. Strength has been increased.

The center outer layer body 9 and the ground electrode 3 are made of a metal having a lower electric resistivity than the center body 8, and a high-frequency current of the center electrode 5 flows through a metal having good electric characteristics.
Low fever.

(Embodiment 2) The sectional view of FIG. 3 showing Embodiment 2 is different from FIG. 2 in the following point. The ground electrode 3 of FIG.
And a grounded outer layer body 11 on the outer periphery of the cylindrical body 10. The grounded outer layer body 11 is formed of a metal having lower electric resistivity than the cylindrical body 10, and the high-frequency current of the ground electrode 3 is a metal having good electric characteristics. Flows through.

In the first and second embodiments, the center outer layer body 9 and the ground outer layer body 11 are attached to the center body 8 and the cylindrical body 10, respectively.
In addition to being formed by coating such as plating and painting, both may be integrated by fitting.

[Embodiment] The metal having a low electric resistivity in the present invention, that is, the metal of the center outer layer body 9, the ground electrode 3, or the ground outer layer body 11 is as follows.
It is composed of silver, copper, gold, aluminum, brass, nickel, tin, chromium or the like, and is desirably composed of at least one of these metals.

The high hardness metal of the center body 8 includes:
In addition to tool steel having excellent hardness, phosphor bronze may be used.

Next, the experimental results will be described. As a conventional example, phosphor bronze is used for the center electrode 5, Teflon is used for the insulator 4, and SUS304 is used for the ground electrode 3. When 60 W, 60 sec is applied as the irradiation condition, the temperature rises to 181.8 ° C. The surface rises to about 100 ° C. as shown by a white circle in FIG. 4 and burns the electrode insertion portion.

On the other hand, as an example of the present invention, SK5 of tool steel is used for the center body 8 of the center electrode 5, silver plating is used for the center outer layer body 9, Teflon is used for the insulator 4, and brass is used for the ground electrode 3. When electricity is supplied for 60 seconds, the temperature rises only to 98.5 ° C., and can be reduced to almost half of the conventional example.
As shown by the black circle in FIG. 4, the surface of the mantle tube is about 70 ° C. or less, which can be reduced by 30 to 40% of the conventional example, and can prevent burns at the electrode insertion portion.

When a copper alloy such as brass is used for the ground electrode 3, if there is a concern about a living body, a plating layer such as brass is used for the cylindrical body 10 and gold or the like is used for the ground outer layer body 11 as the ground electrode 3. In this case, the temperature can be further reduced.

When SK5 made of tool steel was used for the center electrode 5 and brass was used for the ground electrode 3, the temperature rose to 200 ° C. or more in about 30 seconds.

[0028]

Since the present invention is configured as described above, it has the following effects. Surgical electrode 2
Is inserted into the deep part of the living tissue, the conical point 7 at the tip of the microwave irradiator 6 at the tip of the center electrode is pierced into the diseased tissue. A microwave electric field is generated between the electrode and the ground electrode 3, and the induced heat causes hemostasis and coagulation of the diseased tissue, necrosis, and performs surgical treatment. At this time, the center electrode 5 is constituted by a rod-shaped center body 8 and a center outer layer body 9 on the outer periphery of the center body 8, and the center outer layer body 9 and the ground electrode 3 are formed by a metal having lower electric resistivity than the center body 8. In addition, since the center body 8 is made of a metal having a higher hardness than the center outer layer body 9, a high frequency current flows through the center outer layer body 9 having good electric characteristics due to a skin effect, so that heat generation is reduced and the surface temperature of the surgical electrode is reduced. It is possible to prevent the burn of the puncture portion of the surgical electrode 2 by making it lower than before. Moreover, the central body 8
Is made of a metal having a higher hardness than the central outer layer body 9, the strength of the surgical electrode can be increased, and the impedance matching state can be improved.

The ground electrode 3 is connected to the cylindrical body 10 and the cylindrical body 10.
, The outer peripheral body 11 of the ground
By forming 1 from a metal having a lower electrical resistivity than the cylindrical body 10, it is possible to further reduce the heat generation of the surgical electrode 2 and lower the surface temperature.

[Brief description of the drawings]

FIG. 1 is an overall front view of a first embodiment of the present invention.

FIG. 2A is a partial cross-sectional view of Embodiment 1 of the present invention, and FIG.

3A is a partial cross-sectional view of Embodiment 2 of the present invention, and FIG. 3B is a cut-away side view of A. FIG.

FIG. 4 is a diagram showing the relationship between the distance from the center electrode tip and the temperature of the mantle tube surface.

[Explanation of symbols]

 2 Surgical electrode 3 Ground electrode 4 Insulator 5 Center electrode 6 Microwave irradiation part 7 Point 8 Center body 9 Center outer layer body 10 Cylindrical body 11 Ground outer layer body

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 18/18

Claims (6)

(57) [Claims] 1. A microwave surgical device comprising an elongated surgical electrode supported by a connector connected to a microwave oscillating unit via a coaxial cable and having a distal end inserted into a deep part of a living tissue, A tubular ground electrode serving as an outer conductor of the electrode; a tubular insulator provided at a core of the ground electrode; a tip portion provided at a core portion of the insulator; A rod-shaped center electrode having a tip portion derived from the tip of the insulator; anda microwave irradiator having a sharp conical point formed at a tip located at the tip of the center electrode; The center electrode is constituted by a rod-shaped center body and an outer center layer on the outer periphery of the center body; and the center outer layer body and the ground electrode are formed of a metal having a lower electric resistivity than the center body. Is harder than the center outer layer Microwave surgical instrument characterized by being composed of a metal. 2. A grounding electrode comprising a cylindrical body and a grounded outer layer on the outer periphery of the cylindrical body, wherein the grounded outer layer is formed of a metal having a lower electric resistivity than the cylindrical body. 2. The microwave surgical instrument according to 1. 3. A microwave surgical device of claim 1 Symbol mounting, characterized in that the central outer layer body is formed by a coating on the central body. 4. The center outer layer and the ground outer layer include a center body and a ground outer layer.
Microwave surgical instrument according to claim 2 Symbol mounting, characterized in that it is formed by coating fine cylindrical body. 5. The method according to claim 1, wherein the center outer layer body and the ground electrode are made of silver, copper,
Gold, aluminum, brass, nickel, tin or chrome
Characterized by comprising at least one or more of
The microwave surgical instrument according to claim 1 or 3. 6. The center outer layer and the ground outer layer are made of silver, copper,
Gold, aluminum, brass, nickel, tin or chrome
Consisting of at least one of Feature
The microwave surgical instrument according to claim 2 or 4.