JPS6138707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic wave generator used in hyperthermia therapy, which uses microwave irradiation to heat cancer tissue to stop its regenerative function and lead to death.

The inventors of the present application have proposed the electromagnetic generator shown in FIG. 1 as an electromagnetic generator for use in thermotherapy, which treats cancer tissue by heating it to around 43° C. for a necessary period of time.

In FIG. 1, reference numeral 1 denotes a columnar dielectric body having a relative permittivity εr approximately equal to the relative permittivity of the human body, for example, εr=80, and a loop antenna 2, for example, is attached to one end of the columnar dielectric body 1 as an excitation antenna. The loop antenna 2 has a size of 1/√ of the size in the atmosphere determined by the frequency used, and is excited at a frequency of 500 MHz or less in order to heat the deep part of the human body.

By the way, in the thermotherapy using the electromagnetic wave generator shown in FIG. 1, as shown in FIG. When irradiating electromagnetic waves toward cancer tissue 7 existing inside the human body 3,
It is necessary to prevent burns to the cortical layer due to heating due to dielectric loss in the cortical layer.

However, since a water bag is used, it is difficult to set the electromagnetic wave generator on the human body, and furthermore, there is a fear that a sufficient cooling effect may not be obtained for the parts of the human body that are difficult to insert the water bag into.

The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave generator for thermotherapy that can reliably prevent skin burns during thermotherapy using microwaves and is convenient to handle.

In order to achieve this object, the present invention provides an exposed excitation antenna in the cavity of a columnar case made of an insulating material such as glass or plastic, and fills the cavity of the case with pure water as a dielectric substance. It has a structure in which it circulates as cooling water, and since the dielectric constant of pure water is approximately equal to the dielectric constant of the human body, the reflection loss when the radiation surface of the electromagnetic wave generator is brought into direct contact with the human body can be minimized. The reflux of pure water cools the skin layer where electromagnetic waves are incident, thereby preventing burns.

Hereinafter, the present invention will be explained based on examples.

FIG. 3 is a perspective view showing one embodiment of the present invention.

First, the structure will be described. Reference numeral 10 denotes a columnar case, which is made of an insulating material such as glass or plastic, and has the shape of a hollow cylindrical body with both ends sealed. One end surface of the columnar case 10 forms a radiation surface 12 for injecting electromagnetic waves into the human body,
A pair of feeder lines 14 and 14' from the loop antenna 2 are drawn out from the other end face as an excitation antenna exposed in the cavity inside the columnar case 10. Furthermore, a pair of hose connection pipes 16 and 16' are taken out from the circumference of the case on the loop antenna mounting side and the radiation surface 12 side of the columnar case 10, respectively.

FIG. 4 is a sectional view of the electromagnetic wave generator of the present invention. When used as an electromagnetic wave generator, the columnar case 10 is filled with pure water by supplying pure water from one hose connection pipe 16, and the emitter is emitted. In order to cool the cortical part of the human body that comes into contact with the surface 12, the pure water supplied from the hose connection pipe 16 is drawn out to the hose connection pipe 16' side as shown by the arrow, and the pure water contained in the columnar case 10 is circulated. That's what I do.

Next, the operation of the electromagnetic wave generator of the present invention will be explained.

First, in the electromagnetic wave generator of the present invention having the structure shown in FIGS. 3 and 4, the loop antenna 2 is enclosed as an excitation antenna in a columnar dielectric body made of pure water by filling the columnar case 10 with pure water. It operates as a dielectric antenna.

That is, the dielectric constant of pure water is approximately equal to the dielectric constant of the human body, εr = 80.7, and the pure water filling the columnar case 10 functions as a dielectric waveguide for the microwaves radiated from the loop antenna 2. have Also,
The size of the loop antenna 2 when sealed in a highly dielectric material made of pure water is the same as that in the atmosphere.
1√ of the size determined by the frequency used below 500MHz
Furthermore, the microwave radiated by the excitation of the loop antenna 2 has a relative permittivity εa of the air outside partitioned by the columnar case 10, and εa=1.0.
Relative permittivity of pure water sealed inside εr=80.7
Due to this difference in dielectric constant, the transmitted power of the microwave radiated to the external space through the columnar case 10 is extremely small, and the magnitude of the electromagnetic wave radiated from the loop antenna 2 is sufficiently small. The part is pure water filled inside the columnar case 10,
That is, electromagnetic waves are intensively radiated toward the radiation surface 12 that contacts the human body enclosed in the dielectric waveguide.

FIG. 5 is an explanatory diagram of thermotherapy using the electromagnetic wave generator of the present invention, in which the radiation surface 12 of the columnar case 10 in the electromagnetic wave generator 4 of the present invention is directed toward the cancerous tissue 7 existing inside the human body 3. The hoses 6 and 6' are connected to the hose connection pipes 16 and 16' provided in the columnar case 10 to fill the columnar case 10 with pure water and to remove heat generated by dielectric loss at the contact surface with the human body 3. Reflux pure water for absorption cooling. In this state, the coaxial cable 18
When a microwave signal of 500 MHz or less is supplied to the loop antenna 2 to excite it, electromagnetic wave energy is concentratedly incident on the human body 3 via the dielectric waveguide formed of pure water filled in the columnar case 10, and the columnar case 10 is Since the dielectric constants of the pure water filling the case 10 and the human body 3 are approximately equal, the reflection loss at the contact surface of the electromagnetic wave generator 4 with the human body 3 is small, and the heat generated due to the dielectric loss at the contact surface is It is cooled by the pure water circulating inside the case 10, and prevents burns from occurring in the skin layer of the human body 3 that is in contact with the electromagnetic wave generator 4.

Of course, the electromagnetic wave generator of the present invention has a columnar case 10.
Since the pure water that fills the inside of the body and acts as a dielectric substance also functions as cooling water, there is no need to interpose a cooling water bag between the electromagnetic wave generator 4 and the human body 3, and it is difficult to insert a water bag between the electromagnetic wave generator 4 and the human body 3. Since the electromagnetic wave generator 4 can be brought into direct contact with the human body even if only partially, the position of the electromagnetic wave generator 4 relative to the human body for performing thermal treatment can be easily set and handling becomes extremely convenient.

The above embodiment takes as an example a case in which a columnar case with a circular cross section is filled with pure water as a highly dielectric material, but in the case of a circular cross section, the electromagnetic waves radiated by the loop antenna are Since mode loss is likely to occur due to multiple modes, a columnar case with an oval, elliptical, or polygonal cross section may be used to reduce mode loss even if the electromagnetic wave propagation mode is reduced.

In addition, in the above embodiment, a loop antenna is provided as an excitation antenna in the columnar case, but other embodiments include a dipole used in the frequency band below 500MHz, a linear antenna such as a folded antenna, or a pair of electrodes. It is also possible to use a plate-shaped antenna with a plate arranged thereon, and of course, the size of these excitation antennas may be 1√, which is the size in the atmosphere determined by the frequency used.

Next, to explain the effects of the present invention, first, the dielectric material of the electromagnetic wave generator, which operates as a dielectric antenna with an excitation antenna sealed in a high dielectric material, is filled with pure water, which is approximately equal to the dielectric constant of the human body, in a columnar case. The pure water filled with this dielectric material is circulated as cooling water to absorb the heat generated by the dielectric loss of electromagnetic waves incident on the human body, so it is used as an electromagnetic wave generator for thermal treatment of cancerous tissue. It is no longer necessary to interpose a cooling water bag between the body and the human body, and the electromagnetic wave generator can be easily brought into contact with parts of the human body where it is difficult to intervene with a water bag to perform heat treatment. This makes handling of the electromagnetic wave generator extremely easy. In addition, since the pure water filled in the columnar case has a dielectric constant approximately equal to that of the human body, there is almost no reflection loss at the interface of the electromagnetic waves from the electromagnetic wave generator entering the human body, and cancerous tissue inside the human body It is possible to efficiently irradiate electromagnetic waves to heat the area.

Furthermore, since the pure water that fills the case as a high dielectric material that makes up the electromagnetic wave generator also functions as cooling water, the electromagnetic wave generator and cooling device are integrated, making the electromagnetic wave generator more compact. be able to.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of the electromagnetic wave generator proposed by the inventors of the present application, Fig. 2 is an explanatory diagram of thermotherapy using the electromagnetic wave generator of Fig. 1, and Fig. 3 is the invention of the present invention. FIG. 4 is a perspective view showing one embodiment of the third embodiment.
The cross-sectional view in the figure and FIG. 5 are explanatory diagrams of thermotherapy according to the present invention. 1: Column dielectric, 2: Loop antenna, 3: Human body, 4: Electromagnetic wave generator, 5: Water bag,
6, 6': hose, 7: cancer tissue, 10: columnar case, 12: radiation surface, 14, 14': power supply line, 1
6, 16': Hose connection pipe, 18: Coaxial cable.

Claims (1)

[Claims] 1 A columnar case with a cavity filled with pure water as a dielectric substance, an excitation antenna provided exposed inside the cavity of the columnar case, and a system in which the pure water in the columnar case is circulated as a cooling medium. An electromagnetic wave generator for thermotherapy, characterized in that it consists of a pair of hose connection pipes.