JPS58121966A - Microwave discharge device for heat treatment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave radiator for heating treatment, particularly a microwave radiator that increases the temperature inside a living body by utilizing dielectric loss caused by microwaves. 45
It is known that cancer cells can be killed by heating at °C for a certain period of time, and other treatments can be performed more effectively.

For this reason, a microwave applicator is used as a device to effectively heat the affected area inside the human body, and microwaves are emitted from this applicator towards the affected area inside the human body, and the dielectric loss caused by this microwave is utilized. A device has been proposed that increases the temperature of the affected area. However, since the dielectric loss characteristics inside a living body caused by microwaves of the same intensity are considered to be almost constant regardless of the depth of the living body, when heating the human body using microwaves with the above device,
The temperature inside the human body decreases exponentially as it gets deeper from the surface of the human body. Therefore, the temperature of the affected area within the human body is 43-45°C.
In order to heat the affected area to a certain level, the shallower parts of the affected area are unnecessarily heated to a higher temperature, which is undesirable because healthy tissue is also destroyed.

The present invention was made in view of the above-mentioned problems, and its purpose is to effectively heat an affected area at a predetermined depth of the human body, such as a malignant tumor such as cancer, without raising the temperature of the surface of the human body. An object of the present invention is to provide a microwave radiator for heating treatment.

- In order to achieve the above object, the present invention provides a microwave applicator that radiates microwaves into the human body to heat the inside of the human body;
The applicator is characterized by comprising a cooling device which is provided on the microwave emitting surface of the applicator and cools the surface of the human body by the action of a cooling medium that comes into close contact with the human body during use and flows inside.

Next, preferred embodiments of the present invention will be described.

FIG. 1 is an explanatory diagram of the external appearance of a microwave radiator.

In the figure, reference numeral 10 denotes a microwave applicator connected to the end of a coaxial cable 12 via a connector 14, and in this embodiment, it is formed into a substantially cylindrical shape.

This applicator 10 has an opening on the opposite side of the connector 14, and is structured to radiate microwaves toward the human body from this opening. Reference numeral 16 denotes a Teflon sheet bag 1) as a cooling device, which is placed at the opening of the applicator 10, that is, the microwave radiation surface, and when in use, it is brought into close contact with the human body surface 9 and flows into the bag through the inlet 18 and the outlet. The cooling water flowing out from 20 forcibly cools the surface of the human body. In this embodiment, since the applicator 10 and the seat bag 16 are formed separately, a space for positioning the seat bag 16 between the applicator 1o and the human body is secured during use, and furthermore, the applicator 10 and the seat bag 16 are formed separately. A spacer 22 is provided for positioning the applicator 10 and setting the microwave radiation direction of the applicator 1o. This spacer 22 consists of a support plate 24 fixed to the applicator 1o, and a pair of legs 26 provided at both ends of the support plate 24.The legs 26 are positioned at the tips of the legs 26 to come into contact with the human body. A rubber cover name is provided, and its height can be adjusted as desired by changing the screwing position with the support plate 24.

The present invention consists of the above configuration, and its operation will be explained next.

First, in this embodiment, a case will be considered in which microwaves are directly radiated into the human body from the applicator 10 without using the cooling device, that is, the Teflon sheet bag 16.

Generally, it is assumed that the dielectric loss caused by microwaves inside the human body is almost constant regardless of its depth, so the heating inside the body due to microwaves decreases exponentially from the surface of the human body as shown in the following equation: do.

T(t) = To-e・・・・・・・・・Mountain・
・・・・・・・・・・・・ filt: Depth from the human body surface α: Constant determined by the high frequency characteristics of the human body TO: Skin temperature on the human body surface Equation (1) above is illustrated in a graph as shown in Figure 2. Shown in middle (a). However, in order to treat malignant tumors such as cancer, it is necessary to heat the affected area located at a predetermined depth within the human body to 43-45°C.
If the temperature exceeds ~45°C, there is a risk that the tissue in this area will be destroyed. Therefore, it is necessary to sufficiently raise the temperature of the affected area while lowering the temperature of the surface of the human body that is irradiated with microwaves to prevent destruction of healthy tissue.

Therefore, in the present invention, the height of the legs 26 of the spacer 22 is adjusted, the Teflon sheet bag 16 is positioned between the opening of the applicator 10 and the human body surface, and the Teflon sheet bag 16 is further cooled. By constantly flowing water in and out, the surface of the human body, which is heated by the microwaves radiated from the applicator 10 toward the human body, is cooled. The heating characteristic inside the human body obtained by causing the cooling water to flow in and out of the seat bag 16 in this way is shown by the curve (b) in FIG. As is clear from the figure, according to the present invention, it is possible to prevent the temperature rise on the surface of the human body and effectively warm the affected area within the body.

In this embodiment, water was used as the cooling medium passing through the seat bag 16. This is because the dielectric loss characteristics of water are close to those of the human body, and their high frequency characteristics are also similar, so the reflection of microwaves that occurs at the interface between water and the human body is This is because it is expected to be extremely small compared to the microwave reflection that occurs at the interface with the However, if such microwave loss is not a problem, other types of cooling media can also be used.

According to an animal experiment using rabbit thigh muscles, when cooling water at 15° C. was flowed at 125 CC per minute in the seat bag 16 and 50 W microwaves were radiated from the applicator 10 to the muscle for 4 minutes. , the skin temperature To of the muscle is 4
4 points at a depth of 1411g1 within the muscle while maintaining the temperature at 0°C.
It has been confirmed that it can be heated up to 5゛CK.

Note that the point to be noted in the present invention is that the seat bag 16
Some percent of the microwave energy radiated from the shear applicator 1° is consumed by the cooling water flowing inside. According to experiments, when cooling water at 24°C was flowed at a rate of 100 cc per minute into the seat bag 16 with a thickness of 5 m, and the water was heated at 25.9°C as a load, 50 cm of the irradiated energy was It has been confirmed that it is consumed by cooling water. Therefore, in order to heat the affected area within the body to a predetermined temperature, it is necessary to take into account the energy loss of the microwave within the cooling device and increase the energy by this loss before emitting the microwave.

11 Additionally, the size of the microwave energy emitted from the applicator 10 and the seat bag 16
By adjusting the temperature of the cooling water inside the body, the temperature distribution in the depth direction inside the body can be freely adjusted. Also, in the above embodiment, the applicator and the cooling device were formed separately. This was explained using a microwave radiator as an example. However, the present invention is not limited to this, and the applicator and cooling device can also be formed integrally. FIG. 3 is a side sectional view showing one embodiment of the microwave radiator formed in this manner.

In the figure, the cooling device 16 is a Teflon sheet bag in which two Teflon sheets (30, 32) are placed at the opening of the applicator 10 with a certain gap between them.
．． The end of 32 is hermetically fixed to the opening edge of applicator 10, and cooling water is allowed to flow into the space surrounded by these two sheets 30 and 32. The above Teflon seams) 30, 32 are fixed to the applicator 10 by 0.
rings 34 and 36, and a ring-shaped gasket 38 having a substantially L-shaped cross section and engaging with the outer edge of the opening of the applicator 10.
, an elastic support member 4 that presses this seal further inward.
0. First, the O-ring 34 is fitted into the groove 42 formed on the outer edge of the opening of the applicator 10, and the end of one Teflon sheet 30 is sealed and fixed between the O-ring and the inner side of the ring-shaped packing. Here, a concave groove 38a is formed at a position of the packing 38 facing the O-ring 34 to improve the degree of sealing of the Teflon sheet 30. Further, O is formed on the inner surface of the elastic support member 40.
The ring 36 is adhesively fixed, and the end of the other Teflon sheet 32 is sealed and fixed between the 01J ring 36 and the packing 38. Note that a groove 38b is formed at a position of the gasket 38 facing the O-ring 36 to improve the degree of sealing of the Teflon sheet 32. In the space surrounded by the Teflon sheets 30 and 32 supported and fixed in this way, there are an inlet 18 and an outlet 20 formed in the packing 38.
Cooling water is injected and discharged from the pump to cool the surface of the human body, as described above.

According to the present invention, microwaves are used to effectively heat and treat affected areas within the human body, such as malignant tumors such as cancer, and a cooling device is used to effectively reduce the temperature rise on the surface of the human body caused by the microwaves. By suppressing the temperature, it becomes possible to effectively heat only the affected area within the body without destroying the healthy tissues existing on the surface of the human body.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of a microwave radiator for heating treatment according to the present invention, Fig. 2 is a heating characteristic diagram inside the human body, and Fig. 3 is a side sectional view showing another embodiment of the present invention. be. Corresponding members in each figure are given the same reference numerals, 10 is an applicator, and 16 is a cooling device. Applicant Aloka Co., Ltd. Sai 1 Illustration 2 M Sai 3 Illustration 8b

Claims (1)

[Claims] (zl A microwave applicator that radiates microwaves into a human body to heat the inside of the body, and a cooling medium that is provided on the microwave radiation surface of this applicator and that comes into close contact with the human body during use and that flows inside the body.) A microwave radiator for warming treatment, characterized in that it is equipped with a cooling device that cools the surface of the human body by its action. (2. In the microwave radiator according to claim (1), the cooling device A microwave radiator for heating treatment, characterized in that it uses a seat bag as a seat bag and has a structure in which cooling water flows in and out of the seat bag.