JPH0322788B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to microwave treatment devices such as microwave surgical instruments and microwave heating treatment devices (hyperthermia).

[Conventional technology]

In recent years, the application of microwaves to medical care has made remarkable progress, and the methods of its application are being expanded day by day, contributing to the advancement of medical care.

In other words, conventionally used microwave therapy devices treat diseases by irradiating microwaves from outside the human body to improve blood circulation and promote metabolism, but recently, By irradiating microwaves from the outside of the human body or directly into the human body, the dielectric heat generated in biological tissue is maintained and controlled at 42±1℃ for a certain period of time, and this process is repeated.
Microwave heating treatment devices (hyperthermia) that treat malignant tissues such as cancer and tumors by causing physiological degeneration, and microwaves are used to treat organs exposed through incisions in the human body, endoscopes, laparoscopes, etc. This is caused by direct irradiation of internal organs using
Microwave surgical instruments that coagulate, stop bleeding, and partially resect malignant tissue using dielectric heat at temperatures above 0.degree. C. are being put into practical use as new medical devices.

By the way, when such therapeutic equipment is used clinically, physiological information of the patient, such as blood pressure, body temperature, pulse rate, pulse wave, and electrocardiogram, is constantly monitored during surgery and treatment. Sensor sections of various monitoring devices (medical electrical devices) that monitor clinical information are attached to or inside the body of a patient.

In this case, these monitoring devices, like microwave heating treatment devices and microwave surgical devices, must be grounded to prevent electrocution of patients and surgeons due to leakage current of commercial alternating current, and to prevent induced interference caused by commercial alternating current. is required.

However, as mentioned above, when using a body-contact type microwave treatment device such as a microwave heating treatment device or a microwave surgical device together with a physiological information monitoring device, the treatment electrodes of the treatment device Under such circumstances, the sensor part of the monitoring equipment is connected to the human body fluid, which is a good electrical conductor.
If for some reason a current of about 500 μA flows through the heart between the therapeutic electrode and the sensor part, the heart will cause ventricular fibrillation (microshock), which can lead to extremely dangerous conditions such as cardiac arrest. I will do it.

For example, Fig. 4 shows a case where a microwave heating treatment device or a microwave surgical device is used in combination with an intracardiac blood pressure monitor, and in the figure, 1 indicates a microwave treatment device with a built-in microwave generator. 2 is a treatment electrode that is connected to the device body 1 via a coaxial cable 3 and irradiates microwaves from a generator. In a microwave surgical instrument, this corresponds to a surgical electrode inserted into an internal organ B in advance. Reference numeral 4 denotes the main body of the intracardiac blood pressure monitor, whose input terminal is connected to a cardiac catheter 5 inserted into the heart C via a blood pressure transducer 6, and continuously monitors changes in intracardiac blood pressure. do. 7 and 8 are power cords for the device main body 1 and the monitor main body 4, and 9 and 10 are ground wires for the device main body 1 and the monitor main body 4.

In such a state, the grounding by the grounding wire 9 of the device body 1 may be incomplete, or the grounding by the grounding wire 9 may be incomplete.
If it comes off, the leakage current of the commercial alternating current of the treatment equipment will
As shown by the one-dot chain arrow in the figure, the power cord 7
From there, it passes through the generator outer body in the device main body 1, passes through the outer conductor of the coaxial cable 3, reaches the treatment electrode 2, flows through the tissue of the internal organ B, and flows into the nearby heart C. Furthermore, the leakage current flowing into the heart C passes through the physiological saline in the catheter 5 inserted into the heart C, and reaches the metal pressure-receiving membrane of the blood pressure transducer 6.
It flows into the monitor main body 4 from the input terminal, and flows to the ground via the ground wire 10.

Therefore, ventricular fibrillation occurs in the patient's heart C due to the electric shock of the leakage current, resulting in a dangerous situation such as cardiac arrest.

Furthermore, FIGS. 5 and 6 show the case where a microwave treatment device, particularly a microwave surgical instrument, is used in combination with an intracardiac blood pressure monitor. In this case, by inserting a needle-shaped therapeutic electrode (surgical electrode) 2 into body tissue B, such as the liver, and irradiating it with microwaves, the local tissue of body organ B is stopped and coagulated, and the purpose of the surgery is achieved. However, the tissue dries due to the high-temperature dielectric heat and adheres to the treatment electrode 2, making it difficult to remove the needle, and if the tissue is forcibly removed, rebleeding often occurs. For this reason, this type of microwave treatment equipment is provided with a tissue dissociation device to facilitate removal of the treatment electrode 2 after surgery.

That is, a tissue dissection power source 11 made of a DC power source is provided in the device body 1, and the negative terminal of the power source 11 is connected to the coaxial cable 3 through a relay contact 13 in a coaxial relay device 12 that is connected to the coaxial cable 3. connected to the internal conductor 3a of the internal conductor 3a.
The positive terminal of the electrode 11 is connected to the outer conductor 3b of the coaxial cable 3 via the coaxial relay device 12, and the electrode at the base of the therapeutic electrode 2 is connected to the outer conductor 3b of the coaxial cable 3 via the coaxial relay device 12. Further, the positive terminal of the power source 11 is directly connected to the auxiliary electrode 15 without using the coaxial cable 3.

Here, 16 is a microwave generator such as a magnetron built into the device body 1, and the generator 1
The end of the inner conductor 3a of the coaxial cable 3 is introduced into the cavity coupler 18 on the metal outer body 17 of No. 6, and the outer conductor 3b of the coaxial cable 3 is inserted into the cavity coupler 18, the metal outer body 17 and the ground wire 9 is grounded, and 19 is a foot switch that turns on and off the relay contact 13.

Therefore, the microwave generated by the generator 16 is irradiated from the treatment electrode 2 through the internal conductor 3a of the coaxial cable 3 to stop bleeding and perform coagulation surgery on the tissue of the internal organ B, and then the auxiliary electrode 15 is pressed near the surgical site. In addition, when the metal body 14 of the treatment electrode 2 is pressed against the surgical tissue and the foot switch 19 is operated to turn on the relay contact 13, the direct current (about 10 mA) of the power source 11 is transmitted from the auxiliary electrode 15 and coaxially. from the metal body 14 through the outer conductor 3b of the cable 3,
Moisture flows through the coagulated tissue to the therapeutic electrode 2, and due to electrolysis and electroosmosis, water is generated and concentrated at the interface between the electrode 2 and the tissue, making it extremely easy to remove the needle from the therapeutic electrode 2. It will be done.

However, in such a configuration, when operating the tissue dissection, if the foot switch 19 is accidentally operated and the DC power of the tissue dissection power source 11 is applied while the auxiliary electrode 15 and the metal body 14 are not in contact with the tissue, the power source 11 The direct current of coaxial relay device 1
2. Outer conductor 3b of coaxial cable 3, generator 16
and flows to the earth via the ground wire 9, and further,
This current flows into the monitor body 4 from the ground wire 10 of the intracardiac blood pressure monitor, reaches the heart C from the input terminal through the metal pressure-receiving membrane of the blood pressure transducer 6 and the physiological saline in the catheter 5, and flows through the body fluids. This will flow to the treatment electrode 2 inserted into the internal organ B. In other words, the direct current for tissue dissection (at least 10°) will unexpectedly flow through the heart, and there is a strong possibility that this will lead to extremely dangerous situations such as ventricular fibrillation and cardiac arrest.

In addition, in earlier microwave surgical instruments, microwave surgery such as hemostasis and coagulation was performed using an endoscope without exposing the internal organs of the patient's body without making any incisions in the patient's body. Tissue dissection of the treatment electrode 2 is carried out by pressing the metal body 14 at the base of the electrode 2 against the tissue, but when the metal body 14 is not sufficiently pressed against the tissue, the foot switch 1 is
If 9 is operated, a situation such as ventricular fibrillation or cardiac arrest will occur as described above.

[Problem that the invention seeks to solve]

Therefore, in the present invention, in a microwave therapy device used together with a physiological information monitoring device electrically connected to the heart, leakage current of commercial alternating current or direct current of a tissue dissection power source passes through the heart to the monitoring device. The technical challenge is to prevent any flow between the two.

[Means for solving problems]

This invention is used in conjunction with a monitoring device that monitors physiological information by electrically connecting to the heart, and includes a built-in microwave generator. A microwave treatment device that directly irradiates internal tissues of the microwave generator is characterized in that the output circuit of the microwave generator is provided with an electrical insulator that blocks low frequencies and direct current.

[Effect]

Therefore, in the microwave treatment device of the present invention configured as described above, the coaxial cable and the treatment electrode connected to the output circuit of the microwave generator are grounded against low frequencies and direct current by an electrical insulator. Therefore, commercial alternating current leakage current and direct current will not flow between the monitoring device and the treatment electrode, and these currents will be prevented from flowing through the heart.

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 3 showing one embodiment thereof. Note that the same symbols as above indicate the same or corresponding items.

First, what is shown in FIG. 1 is a microwave generator 16' made of a magnetron built into the main body 1 of a microwave treatment device.
20 is a chassis grounded via a ground wire 9;
Reference numeral 21 denotes a metal outer body that is electrically connected to the chassis 20, that is, grounded, and houses a thermionic tube, a permanent magnet, a radiator, etc.;
A thermionic tube antenna 22 protrudes from the center of the top surface of 1. 23 is a cavity coupler called a cavity attached to the metal outer body 21;
The antenna 22 is introduced into the cavity coupler 23, and the metal coaxial connector 24 of the coaxial cable 3 is connected to the threaded portion 23' of the cavity coupler 23 by introducing its coupling rod 25 into the cavity coupler 23. ing.

26 is a thermally conductive silicone rubber or the like that is provided between the metal outer body 21 and the cavity coupler 23, which constitute a part of the output circuit of the microwave generator 16', and cuts off low frequency and direct current between the two. thin plate (thickness 0.3
mm), and as shown in FIGS. 2 and 3, there is a circular hole 26a equal to the inner diameter of the lower end periphery of the cavity coupler 23 and several bolt insertion holes 2.
6b is transparent, and as shown in FIG.
8 to the bolt insertion hole in the lower end periphery of the cavity coupler 23 and the bolt insertion hole 26b in the electrical insulator 26.
By passing it through and fastening it to the metal outer body 21, the cavity coupler 23 is integrally connected to the outer body 21, and an electric insulator 26 is interposed between the two.

Here, since the grounded metal outer body 21 and the cavity coupler 23 are coupled at ultra-high frequencies without problems such as power loss and frequency deviation, the thermionic tube oscillates and the cavity coupler 23 is connected to the antenna 22. The microwave emitted into the coaxial cable 3 is transmitted to the output section via the coaxial cable 3 as a microwave electric field between the coupling rod 25 of the coaxial connector 24 and the external metal conductor of the coaxial connector 24 directly connected to the cavity coupler 23. That is, the microwaves are transmitted to the therapeutic electrode 2, and the human body is irradiated with the microwaves from the electrode 2.

Therefore, this kind of microwave generator 16'
For example, when installed in a microwave treatment device such as a microwave heating treatment device or a microwave surgical device shown in FIG. Even in this case, the leakage current of the commercial alternating current is blocked by the electrical insulator 26 between the metal outer body 21 and the cavity coupler 23, so that the leakage current flows from the therapeutic electrode 2 through the human body A, particularly the heart C, into the heart. It will not flow to the blood pressure monitor side, and situations such as ventricular fibrillation and cardiac arrest will be avoided.

Furthermore, when the microwave generator 16' is applied to the microwave surgical instrument shown in FIGS. Even if the foot switch 19 is operated by mistake without contacting the tissue, the direct current from the tissue dissection power source 11 will be interrupted by the electrical insulator 26 and will flow from the metal outer body 17 to the ground through the ground wire 9. This current flows from the catheter 5 of the intracardiac blood pressure monitor to the heart C.
It does not flow through the treatment electrode 2, thereby avoiding situations such as ventricular fibrillation and cardiac arrest.

Note that the present invention is not limited to the case where the microwave therapy device is used in combination with an intracardiac blood pressure monitor, but can be implemented in the same way when used in combination with other monitoring devices that monitor physiological information of the heart, and the same effect can be achieved. It is something that can be obtained.

〔Effect of the invention〕

As described above, according to the microwave treatment device of the present invention, the treatment electrode that comes into contact with living tissue can be insulated from the ground in terms of low frequency and direct current using an electric insulator via a coaxial cable. Even if there is a mishandling of the device or the ground wire is disconnected or dropped, there will be no risk of leakage current of the commercial AC of the device itself or the effects of medical purposes due to the connection between the physiological information monitoring device and the living body and the earth. Current (DC current)
This has the unique effect of significantly improving safety, as there is no possibility of dangerous conditions such as ventricular fibrillation or cardiac arrest caused by electric shock to the heart.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the microwave treatment device of the present invention, in which FIG. 1 is a front view of the microwave generator, FIG. 2 is an exploded perspective view of the main parts of FIG. 1, and FIG. Figure 3 is a plan view of the electrical insulator, Figures 4 and 5 are illustrations of microwave treatment, and Figure 6 is a plan view of the electrical insulator.
The figure is a configuration diagram of the microwave treatment equipment in FIG. 5. 2...Treatment electrode, 3...Coaxial cable, 1
6'...Microwave generator, 26...Electric insulator,
A...human body, B...internal organs, C...heart.

Claims (1)

[Claims] 1 It is used in conjunction with a monitoring device that is electrically connected to the heart to monitor physiological information, and it has a built-in microwave generator, and the microwaves from the generator are transmitted to the internal tissues of the living body via a coaxial cable to a therapeutic electrode. 1. A microwave treatment device configured to directly irradiate energy, characterized in that the output circuit of the microwave generator is provided with an electric insulator that blocks low frequencies and direct current.