JPH0728926B2 - Hyperthermia device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hyperthermia device used for treating a tumor by hyperthermia.

[Conventional technology]

The hyperthermia device selectively heats cancer cells to a temperature of 42 to 43 ° C. or higher, focusing on the fact that cancer cells are more susceptible to heat than normal cells, and various proposals have been made so far. For example, in JP-A-53-48389, a plurality of sets of electrodes are used, two opposing electrodes are switched and selected, and high-frequency energy is applied between the selected electrodes to heat the living body. Things are disclosed.

[Problems to be solved by the invention]

In the above-mentioned conventional hyperthermia device, the high-frequency energy output is set to zero when switching the electrodes,
After switching, high frequency energy is applied between the electrodes through a matching circuit corresponding to the electrodes switched and selected as a desired high output. However, the impedance of the load circuit including the selected electrode changes due to various factors such as the condition of the living body, the contact state of the electrode, and the disconnection of the electrode from the connecting portion. When high-power high-frequency energy is supplied, there is a problem that the equipment is damaged by high reflected power due to impedance mismatch, and the patient is exposed to electric shock.

The present invention has been made in view of such conventional problems, and effectively prevents equipment from being damaged due to impedance mismatch due to switching of electrodes and exposing a patient to danger such as electric shock. It is an object of the present invention to provide a hyperthermia device properly configured so that it can always be used safely.

[Means and Actions for Solving Problems]

In order to achieve the above-mentioned object, in the present invention, two electrodes are switched and selected by switching means from three or more electrodes that give high-frequency energy for heating a living body, and the two electrodes are selected between the selected two electrodes. While supplying the high frequency energy from the high frequency oscillating means through the variable matching device,
The high frequency energy output of the high frequency oscillating means is switched to a low output or zero before switching the electrodes, and after the electrodes are switched, the impedance is matched by the variable matching device in a low output state and then switched to a desired high output. .

〔Example〕

FIG. 1 shows an embodiment of the present invention. In this embodiment, one body electrode (hereinafter referred to as the first electrode) 1
And two body electrodes (hereinafter referred to as the second and third electrodes) 2,3
The two switches are automatically switched and selected by the changeover switch 4, and the input impedance of the load circuit including the selected two electrodes and the output impedance of the RF oscillator 5 are automatically selected by the variable matching device 6. Then, high-frequency energy is supplied from the RF oscillator 5 between the two selected electrodes. The changeover switch 4 and the variable matching device 6
Are provided on the interface 7 located near the patient.

The first electrode 1 is inserted into the body cavity 9 of the living body 8 and arranged so as to face the tumor 10. The first electrode 1 is covered with a balloon 11, and a conductive liquid medium such as physiological saline is circulated through the balloon 11 via a heat exchanger (not shown) provided outside, so that the balloon 11 is in contact with the portion. The inner wall of the body cavity should be heated or cooled.

Further, the second electrode 2 is arranged on one surface of the living body 8 so as to face the first electrode 1 and the tumor 10, and the third electrode 3 is, for example, the other surface of the living body 8 so as to face the second electrode 2. To place. These second and third electrodes 2 and 3 are brought into contact with the living body 8 via the balloons 12 and 13 as with the first electrode 1, and
A conductive liquid medium such as physiological saline is circulated through the balloons 12 and 13 via a heat exchanger (not shown), thereby cooling the living body surface at the portion where the balloons 12 and 13 are in contact. The heating or cooling system by the liquid medium in the first electrode 1 and the cooling system by the liquid medium in the second and third electrodes 2 and 3 are electrically separated from each other.

FIG. 2 is a block diagram showing a configuration of an example of the RF oscillator 5 shown in FIG. In this example, the high frequency energy (RF signal) from the oscillator 21 is supplied to the high frequency amplifier 22 and the matching device 23.
To the coaxial cable 24. The matching unit 23 is for matching impedance with the coaxial cable 24, and the output end of the coaxial cable 24 is connected to the variable matching unit 6 of the interface 7 arranged near the patient. The interface 7 is provided with connectors 31, 32, and 33 in addition to the variable matching unit 6 and the changeover switch 4, and these connectors 31 to 33 are provided with first to third electrodes 1 to 3 (first electrode) via RF cables, respectively.
(Refer to the drawing), two electrodes are switched and selected from these electrodes by the changeover switch 4, and the RF signal supplied between the selected electrodes via the coaxial cable 24 is supplied to the variable matching unit 6 and the changeover switch 4. So that the voltage is applied. In this example, the switching of the electrodes by the changeover switch 4 is automatically controlled by the main control unit 34 according to a predetermined program. Further, the interface 7 is provided with connectors 35, 36, 37 for the temperature detector, and these connectors 35
~ 37 are connected to temperature detectors for detecting the temperature of the portion heated by the electrodes, and their outputs are supplied to the main controller 34. The change-over switch 4 can also be program-controlled using the temperature thus detected as a parameter.

On the other hand, between the high frequency amplifier 22 and the matching unit 23, a phase measuring device 38 and a transmission type power meter 39 are connected, and the phase of the RF signal is input by the phase measuring device 38 and the RF signal is input by the transmission type power meter 39. Measure the power and the reflected power respectively. The outputs of the phase measuring device 38 and the transmission type wattmeter 39 are supplied to the main control unit 34 and the automatic matching control unit 40, and the automatic matching control unit 40 controls the variable matching unit 6 to change the switch 4 The input impedance of the load circuit including the two electrodes selected in step 1 is automatically matched with the output impedance of the coaxial cable 24, that is, the RF oscillator 5.

The high-frequency amplifier 22 is driven by the power supply unit 41, and the output ON / OFF control unit 42 controls the power supply unit 41 to ON / OFF control the output of the high-frequency amplifier 22. Output ON / OFF control unit 42
Is controlled by the main control unit 34 based on the output of the temperature detector that detects the temperature of the heating portion, and when the temperature of the heating portion detected by the temperature detector becomes equal to or higher than the set temperature, the high frequency amplifier The output of 22 is turned off, and it is turned on when the temperature falls below the set temperature.

Further, the reflected power measured by the transmission power meter 39 is also supplied to the overreflection monitoring unit 43, and when the reflected power exceeds the reference value as compared with a predetermined reference value, the signal is displayed by the overreflection. Bowl 44
Is supplied to display the occurrence of overreflection, and the main control unit 34
And the forced OFF control unit 45 to supply the forced OFF control unit 45.
Controls the RF signal output from the high-frequency amplifier 22 to be forcibly turned off via the output ON / OFF control unit 42 and the power supply unit 41. This prevents damage to the equipment due to excessive reflected power due to a sudden impedance mismatch due to the electrodes coming off the connectors 31 to 33.

In this embodiment, the amplification factor of the high frequency amplifier 22 is controlled by the main controller 34.
In this way, the output of the high-frequency amplifier 22 becomes low when the matching state becomes worse than a certain reference value at the start of oscillation, before and after the switching of the electrodes by the changeover switch 4, and during the supply of the RF signal. For example, the desired high output
When the output power is 500 W, the output power is set to 50 W), and automatic matching is performed in this low output state, and after the desired matching is achieved, the output is controlled to the desired high output. In this way, device damage due to impedance mismatch at the start of oscillation or when RF signals are supplied to the living body due to electrode switching and during supply is effectively prevented, and the risk of electric shock to the patient is effectively prevented. To do.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications and changes can be made. For example, in the above-described example, the output of the high frequency amplifier 22 is low and the changeover switch 4 is used to switch the electrodes. However, the output is once turned off from a low output, or a high output is obtained without a low output. It is also possible to switch the electrodes from the state to off and switch the electrodes, and after switching, perform low-power automatic matching. Further, the switching of the electrodes by the changeover switch 4 is not limited to automatic, but may be configured to be performed manually. In this case, it is preferable to provide a switch for manually switching the output of the high-frequency amplifier 22 to a desired high output, low output and off, and by operating this switch, the output is set to low output or off prior to switching of the electrode, After switching, impedance matching can be performed automatically or manually in a low output state, and after confirmation of the matching by a display device such as a meter, a lamp or a buzzer, a desired high output can be supplied. Further, in the case of manually operating the changeover switch 4 in this way, a lock mechanism is provided so that the changeover switch 4 is locked under the high output state and the electrodes cannot be changed over, or the changeover switch 4 is operated. Is detected by a photoelectric sensor or a contact sensor,
Based on the output, a warning device may be used to warn by sound or light that the operation of the changeover switch 4 is prohibited under a high output state. Further, the number of electrodes is not limited to three, and, for example, a plurality of in-body electrodes to be inserted into a body cavity are provided in the insertion direction, and these electrodes are selected and used together with a plurality of external electrodes. It is also possible to switch and select two electrodes from the outer electrodes. Furthermore, the present invention can be effectively applied not only to RF but also to the case of using microwaves.

〔The invention's effect〕

As described above, according to the present invention, the high frequency energy output of the high frequency oscillating means is switched to low output or zero before switching the electrodes, and impedance matching is achieved by the variable matching device in the low output state after switching the electrodes. After that, by switching to a desired high output to heat the living body, it is possible to effectively prevent damage to the device due to impedance mismatch due to switching of electrodes, and to make the patient risk of electric shock. It can always be used safely without exposure.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of an example of the RF oscillator shown in FIG. 1 ... Internal electrode, 2,3 ... Extracorporeal electrode 4 ... Changeover switch, 5 ... RF oscillation device 6 ... Variable matching device, 7 ... Interface 8 ... Body, 9 ... Body cavity 10 ... Tumor, 11〜13 …… Balloon 21 …… Oscillator, 22 …… High-frequency amplifier 23 …… Matching device, 24 …… Coaxial cable 31 ～ 33 …… Connector, 34 …… Main control unit 35 ～ 37 …… Connector, 38 …… Phase measuring device 39 …… Transmission wattmeter, 40 …… Automatic matching control unit 41 …… Power supply unit, 42 …… Output ON / OFF control unit 43 …… Overreflection monitoring unit, 44 …… Overreflection display unit 45… ... Forced OFF control unit

Front page continuation (72) Inventor Yasuhiro Ueda 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Shinji Hatta 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Kogyo Co., Ltd. (56) Reference JP-A-63-242277 (JP, A)

Claims (1)

[Claims] 1. A three or more electrode for applying high frequency energy for heating a living body, a switching means for switching and selecting two electrodes from these electrodes, and high frequency energy between the selected two electrodes. The high frequency oscillating means for supplying, the variable matching device for matching the impedance between the load circuit including the electrode selected by the switching means and the high frequency oscillating means, and the high frequency energy output of the high frequency oscillating means, the switching means Means for switching to a low output or zero prior to switching of the electrodes by means of, and for switching to a desired high output after matching by the variable matching device in a low output state after switching of the electrodes. .