JPH03977Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a microwave scalpel whose rear end is connected to a microwave generator and which irradiates microwaves to living tissue from the tip of a high-frequency coaxial cable. It is.

[Problems that conventional technology and ideas try to solve]

Conventional microwave scalpels are of the so-called unipolar electrode type, in which a needle-like electrode is connected to a central conductor and together with an indifferent electrode constitute a unipolar antenna. This makes it possible to easily perform bloodless surgery even on fragile parenchymal organs that contain a large amount of blood. However, when the needle electrode is removed from the living body while microwaves are being generated, there is no load and a standing wave is generated, even if the handpiece is attached to the cable behind the needle electrode. There was a problem with abnormal heating.

The present invention focuses on the fact that if the energy sent out from the microwave generator for performing the required scalpel treatment can be reduced, it is possible not only to save power but also to avoid the abnormal heating mentioned above, and has developed a highly efficient microwave scalpel. The purpose is to provide.

[Means for solving problems]

In order to achieve this objective, the present invention connects needle-shaped electrodes to the center conductor and outer conductor at the tip of a high-frequency coaxial cable, and connects these needle-shaped electrodes with their tips exposed to form a rigid cutting edge-shaped dielectric. I surrounded myself with my body.

[Effect]

The cutting edge-shaped dielectric functions as a scalpel blade, and the needle-like electrodes act as bipolar electrodes to concentrate microwaves at their tips. Therefore, there is no microwave leakage at the rear end of the needle-shaped electrode where it is not inserted into the living body, and there is no microwave radiation in the middle of the electrode in the living tissue, and radiation is performed only at the tip. Therefore,
The output power of the microwave generator is propagated to the tip of the needle electrode with low loss, and local treatment is performed at the tip.

[Example of idea]

In FIG. 1, 10 is a high frequency coaxial cable whose rear end is connected to a microwave generation circuit, and as is well known, an internal conductor 1 is located at the center of a dielectric 11.
2, and an outer conductor 13 coaxially surrounding this conductor.
and an outer skin 14 surrounding these. Reference numeral 16 denotes a dielectric material, such as ceramic, which has a cutting edge shape and is rigid enough to incise living tissue.
This ceramic has an internal conductor 12 at the rear end.
Two needle-shaped electrodes 17 and 18 connected to the external conductor 13, respectively, are buried with their tips exposed. Reference numeral 19 denotes a hand piece that is fitted into the tip of the cable 10 and the rear end of the ceramic 16 to hold them.

When in use, hold the hand piece 19 with your hand and turn microwave generation on and off using a switch or foot switch attached to the hand piece 19, while radiating microwaves from the tips of both needle-like electrodes 17 and 18 and the ceramic 16. The incision function performs tissue resection, coagulation, and hemostasis. At this time, unlike conventional unipolar electrodes, the microwaves that have propagated through the cable 10 do not leak at the end of the cable, and are hardly radiated from around the ceramic 16, leaving the tips of the bipolar electrodes 17 and 18. radiated intensively.

FIG. 2 shows an experimental example for confirming the effects of the present invention. High frequency coaxial cable 30 with a length of 1.55m
2450MHz, 40W microwave was supplied from the rear end of (RG-62A/U), and three types of comparison electrodes were 0.9%
It was immersed in 10 c.c. of saline solution 31, and its temperature rise over time was measured. Here, Figure 2a corresponds to the conventional unipolar electrode, and the cable 3
A dielectric material 33 protrudes 10 mm from the dielectric material 33, and a needle electrode 32 with a length of 20 mm protrudes further from the dielectric material 33 and is immersed in the saline solution 31. FIG. 2b shows a needle electrode under the same conditions as FIG. 2a, immersed deeper to the outer conductor 35, and corresponds to the bipolar electrode that is the premise of the present invention. FIG. 2c shows a bipolar electrode surrounded by a ceramic 34 having a length of 30 mm according to the present invention, and the spacing between the needle electrodes is 2 mm.

Figure 3 shows the experimental results. The results for Figure 2 a are marked with an ○, the results for Figure 2 b are marked with an x, and the results for the second
Figure c is indicated by a □ mark. This result shows that by using a bipolar electrode for the microwave scalpel, the efficiency is greatly improved compared to the unipolar type. In addition, by embedding both needle-like electrodes in a cutting edge-shaped dielectric material according to the present invention, although the efficiency decreases due to the dielectric loss, on the contrary, heating is performed locally, improving the energy utilization rate. However, in any case, a significant efficiency improvement is possible.

Note that the shape of the needle electrode and its surrounding body can be variously modified depending on the application or impedance matching.

[Effect of idea]

As described above, the bipolar electrode type microwave scalpel of the present invention, which locally treats the necessary areas, greatly improves the efficiency of microwave energy.
It is possible to increase the output power or, conversely, to reduce the output power of the microwave generator. This reduction prevents the handpiece from becoming abnormally heated even if the microwave scalpel is removed from the living body while radiating microwaves. In addition, the envelope of the two needle electrodes acts as a cutting edge, allowing the needle electrode to be inserted deep before making the incision, as in the case of a conventional unipolar type, in order to gradually make a hemostatic incision toward the depth. This eliminates the problem of cutting blood vessels and causing massive bleeding.

[Brief explanation of the drawing]

Fig. 1 shows a microwave scalpel according to an embodiment of the present invention, a is a cross-sectional view thereof, b is a perspective view of its tip, and Figs. 2 a to c respectively confirm the effects of the present invention. The experimental needle electrode and FIG. 3 show the experimental results. 12...Inner conductor, 13...Outer conductor, 16...
...ceramic, 17,18...acicular electrode.

Claims (1)

[Scope of utility model registration request] Needle-like electrodes are connected to the center conductor and outer conductor at the tip of a high-frequency coaxial cable whose rear end is connected to a microwave generator, respectively, and both needle-like electrodes are cut with a rigid cutting blade so as to expose the tips of these electrodes. A microwave scalpel surrounded by a shaped dielectric material.