JPS63242276A - Hyperthermia apparatus - 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 [Field of Industrial Application] This invention relates to a hyperthermia device used to treat tumors by thermotherapy.

[Conventional technology]

As a conventional hyperthermia device, for example, the
There are those described in Japanese Patent Application Laid-Open No. 61-50567.

FIG. 3 shows the configuration of a conventional hyperthermia device, in which high frequency energy from a high frequency oscillation device 1 is applied between electrodes 5 and 6 via one matching box 2 and a cable 3.4. The living body is dielectrically heated between the two. Here, the matching box 2 matches the output impedance of the high-frequency oscillator 1 with the input impedance of a load circuit consisting of cables 3, 4, electrodes 5.6, and a living body interposed between these electrodes. .4 length, electrode 5.6 size and electrode 5
．． Matching with the high frequency oscillator 1 is performed in accordance with changes in the input impedance of the load circuit due to changes in the distance between the oscillators 6, etc.
This allows high frequency energy to be efficiently applied to the living body between the electrodes 5 and 6.

[Problem that the invention seeks to solve]

However, in the conventional hyperthermia device, since the cables 3, 4 connected to the matching box 2 are relatively long, the impedance changes due to these cables 3.4 are large, and therefore the size of the electrode 5.6 and the When including changes in impedance due to changes in the distance between the two, the input impedance of the load circuit changes over a wide range. For this reason, it is extremely difficult to achieve accurate matching using one matching device 2, and therefore there is a problem in that high frequency energy cannot always be efficiently supplied between the electrodes 5 and 6. Further, since matching is performed over a wide range, there is a problem that the matching box 2 is large in size and has a complicated configuration.

This invention was made by focusing on these conventional problems, and it is possible to always achieve accurate matching, so that high frequency energy can always be efficiently supplied, and the matching device is also small and has a simple configuration. It is an object of the present invention to provide a hyperthermia device appropriately configured to achieve the following.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plurality of matching devices between a high-frequency oscillation means and an electrode for applying high-frequency energy from the high-frequency oscillation means to a living body. A matching device provided near the electrode is used as a variable matching device, and these matching devices share the task of matching the output impedance of the high frequency oscillation means and the input impedance of the load circuit connected to the variable matching device.

(Function) In the above configuration, since the variable matching device at the last stage is provided near the electrode, the cable connected from this variable matching device to the electrode can be short.

Therefore, the change in impedance of the load circuit connected to this variable matching box is small, and the variable matching box can easily and accurately match this load circuit with the connection cable from the previous matching box. Good alignment can be achieved, and the configuration can be made simple and compact.

In addition, in the matching box at the front stage, it is only necessary to match the cable connected to the variable matching box at the next stage and the matching box or high frequency oscillation means at the previous stage, so matching can be done easily and accurately. In addition, the configuration can be made simple and compact.

〔Example〕

FIG. 1 shows an embodiment of the present invention.

The RF oscillation device 11 is provided with an RF oscillation means 12 and a fixed matching box 13, and one end of a coaxial cable 14 is connected to this matching box 13. Further, an interface 16 is arranged near the living body 15, a variable matching device 17 and a changeover switch 18 are provided on this interface 16, and the other end of the coaxial cable 14 is connected to the variable matching device 17.

One intracorporeal electrode 21 and two extracorporeal electrodes 22 and 23 are connected to the interface 16, and a changeover switch 18 is used to switch between these two electrodes.

In this way, in this embodiment, the matching box 13 allows the RF
The oscillation means 12 and the coaxial cable 14 are matched, and the variable matching device 17 matches the coaxial cable 14 with a load circuit including the two electrodes selected by the changeover switch 18, and the selected two electrodes are matched. High frequency energy from the RF oscillation means 12 is supplied between the electrodes.

Note that the in-body electrode 21 is inserted into the body cavity 24 of the living body 15 and placed so as to face the tumor 25 . This internal electrode 21
is covered with a balloon 26, and an electrically conductive liquid medium such as physiological saline is circulated through the balloon 26 via an external heat converter (not shown).
The inner wall of the body cavity is heated or cooled where it comes in contact with the body cavity.

Further, the extracorporeal electrode 22 is placed on one surface of the living body 15 so as to face the intracorporeal electrode 21 and the l1ffi tumor 25,
Further, the other extracorporeal electrode 23 is placed on the other surface of the living body 15, for example, so as to face one extracorporeal electrode 22.

These extracorporeal electrodes 22 and 23 are brought into contact with the living body 15 via balloons 27 and 28 in the same manner as the intracorporeal electrodes 21, and the balloons 27 and 28 are filled with a conductive liquid medium such as physiological saline using a heat exchanger (not shown). The balloons are circulated through the balloons 27 and 28, thereby cooling the living body surface in contact with the balloons 27 and 28. Note that the heating or cooling system using a liquid medium in the internal electrode 21 and the external electrode 22,
The cooling systems using each liquid medium in 23 are configured to be electrically separated from each other.

FIG. 2 is a block diagram showing the configuration of an example of the above-mentioned RF oscillation device 11. In this example, high frequency energy (RF multiplied signal) from an oscillator 31 is supplied to a coaxial cable 14 via a high frequency amplifier 32 and a matching box 13.The output end of the coaxial cable 14 is placed near the patient as described above. It is connected to the variable matching box 17 provided in the interface 16.The interface 16 has a connector 33.3.
4 and 35 are provided, and the internal and external electrodes 21 to 23 (see FIG. 1) are connected to these connectors 33 to 35 via conductive wires, respectively, and two electrodes are switched and selected from these electrodes using a changeover switch 18. The RF double signal is applied between the selected electrodes via the variable matching device 17 and the changeover switch 18, which is supplied via the coaxial cable 14. In this example, switching of electrodes by the changeover switch 18 is controlled by the main control unit 36 according to a predetermined program. In addition, the interface 16 is provided with connectors 37, 38, and 39 for temperature sensors, and temperature sensors that detect the temperature of the portion heated by the electrodes are connected to these connectors 37 to 39, and their outputs are sent to the main control unit. 36
supply to. Note that the changeover switch 18 can also be program-controlled using the thus detected temperature as a parameter.

On the other hand, a phase measuring device 40 and a transmission type power meter 41 are connected between the high frequency amplifier 32 and the matching device 13. Measure the power and reflected power respectively. The outputs of the phase measuring device 40 and the transmission power meter 41 are supplied to the main control section 36 and the automatic matching control section 4.
2, and the automatic matching control section 42 controls the variable matching device 1.
7 to automatically match the input impedance of the load circuit including the two electrodes selected by the changeover switch 18 with the output impedance of the coaxial cable 14, that is, the RF oscillator 11.

The high frequency amplifier 32 is driven by a power supply section 43, and under the control of the main control section 36, the power supply section 43 outputs 0N.
The frequency amplifier 32 is controlled by the 10FF control unit 44.
The output is controlled by 0N10FF. This allows, for example, to turn off the RF signal output when selecting electrode switching with the changeover switch 18, or to turn off the RF signal output when the temperature of the heated part detected by the temperature detector exceeds the set temperature, or to turn it off when the temperature of the heated part detected by the temperature detector exceeds the set temperature. control so that it turns on when the

In addition, the reflected power measured by the transmission power meter 41 is also supplied to an overreflection monitoring section 45, where it is compared with a predetermined reference value, and when the reflected power exceeds the reference value, the signal is displayed as an overreflection display. 46 to display the occurrence of hyperreflection, and also to the main control section 36 and forced OFF control section 47, and the forced OFF control section 47 outputs 0N10FF control section 44.
and RF from the high frequency amplifier 32 via the power supply section 41
Control to forcibly turn off the signal output. This prevents damage to the equipment due to excessive reflected power due to sudden impedance mismatching caused by electrodes falling off from the connectors 33 to 35 or the like.

Furthermore, in this example, the amplification factor of the high frequency amplifier 32 is controlled by the main control unit 36, so that when oscillation starts, when the supply of the RF multiplied signal to the living body is started by switching the electrodes with the changeover switch 18, and when the RF multiplied signal When the matching condition becomes worse than a certain reference value during signal supply, the output of the high frequency amplifier 32 is set to a low output, and after automatic matching is performed in this low output state and the desired matching is achieved, the output is set to a predetermined value. Control to high output. In this way, R to the living body
Prevents equipment damage due to impedance mismatch at the start of F-fold signal supply or during supply.

As mentioned above, in this embodiment, the matching box 13 matches the RF oscillation means 12 and the coaxial cable 14, and the variable matching box 17 matches the coaxial cable 14 and the load circuit, thereby generating RF oscillation. Since the matching between the means 12 and the load circuit is shared, matching can always be achieved with high precision, and therefore high frequency energy can always be efficiently supplied, and each matching box 1
3 and 17 can also be made simple and compact.

Note that this invention is not limited to the above-described embodiments (and many modifications and changes are possible. For example, the number of internal electrodes inserted into the body cavity is not limited to one, but multiple in the insertion direction. The number of extracorporeal electrodes is not limited to two, but can also be one or three or more.Also, the changeover switch 18 is not limited to automatic operation, but can be operated manually. Furthermore, the number of matching boxes is not limited to two, and three or more matching boxes may be provided.

〔Effect of the invention〕

As described above, according to the present invention, a plurality of matching devices are provided between the high-frequency oscillation means and the electrodes, and the matching devices provided near the electrodes are made variable. Since the matching with the load circuit is shared, matching can always be achieved with high precision, and therefore high frequency energy can always be efficiently supplied, and each matching box can also be made small and simple in configuration.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of an example of the RF oscillation device shown in FIG. 1, and FIG. 3 is a diagram showing a conventional technique. 11... RF oscillation device 12... RF oscillation means 13... Matching box 14... Coaxial cable 15... Living body 16... Interface 17...
・Variable matching box 18...Selector switch 21...
・Internal electrode 22.23...External electrode 24・
・Body cavity 25 ・II tumor 26-28
···balloon

Claims (1)

[Claims] 1. In a hyperthermia device configured to supply high-frequency energy from a high-frequency oscillation means to a living body via an electrode, a plurality of matching devices are provided between the high-frequency oscillation means and the electrode, and a plurality of matching devices are provided near the electrode. 1. A hyperthermia device characterized in that a matching box is made variable to match the output impedance of the high frequency oscillation means and the input impedance of a load circuit including the electrodes and a living body.