JPH09117456A - Microwave operation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically complete at a proper timing the coagulation of the body tissue by means of microwave irradiation. SOLUTION: This device is provided with a sensor 15 which detects at least either the reflected wave or the progressive wave of the microwave output in the device 1, and a completion judging means which monitors at least either the level or the waveform of the detected wave by the sensor 15 for the microwave output in the device 1 and which judges the completion of the coagulation of the body tissue and, on the basis of this judgment, the microwave output in the device 1 is stopped by an output stopping means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies microwaves from a main body device to a surgical electrode that has been inserted into living tissue,
The present invention relates to a microwave surgical apparatus that coagulates biological tissue in the vicinity of an electrode by irradiating the surgical electrode with microwaves to perform hemostasis, coagulation, incision and the like.

[0002]

2. Description of the Related Art Conventionally, this type of microwave surgical apparatus is disclosed in Japanese Patent Publication No. 1-20619 (A61B17 / 39), Japanese Patent Publication No. 1-20617 (A61B 17/36), etc. It is formed by connecting a monopolar type surgical electrode of various shapes such as a needle shape and a blade shape to a main body device via a coaxial cable in a replaceable manner.

Then, the surgical electrode is pierced or brought into contact with the living tissue, the microwave generator of the main unit is operated to supply the microwave (2450 MHz) of this generator to the surgical electrode, and the living tissue is supplied from this electrode. When the microwave is focused and irradiated inside, the tissue near the electrode is coagulated by using the dielectric heat energy generated in the living body.

By repeating this operation, operations such as hemostasis, coagulation, incision, dissection, and excision of the living body can be performed, and in particular, microwaves of this kind are used for surgery of a real organ such as a liver which has a high hemostasis effect and is fragile and contains much blood. Surgical devices are extremely useful.

When the coagulation by one microwave irradiation is completed, a DC tissue dissociation current whose central conductor is the negative electrode and whose outer conductor is the positive electrode is normally supplied from the main body device to the surgical electrode, and this current is supplied to this current. The tissue attached to the surgical electrode is softened by the electroosmotic action of the living body, and the surgical electrode is easily separated from the biological tissue.

[0006]

In the case of the above-described conventional microwave surgical apparatus, the growth of the coagulation layer due to microwave irradiation cannot be detected, so that the doctor or the like outputs the microwave based on experience and intuition. The time is set by a timer, and the living tissue is irradiated with microwaves for the set time (several tens of seconds) to complete one coagulation each time.

On the other hand, the growth of the coagulated layer by microwave irradiation differs depending on the shape of the surgical electrode, the condition of the living tissue and the like. Therefore, in the conventional device, it is not easy to finish coagulation at an appropriate timing, and the surgical electrode causes a minute spark discharge due to overcoagulation, carbonizing living tissue or attaching tissue to the electrode. There are some problems such as things to do.

An object of the present invention is to automatically end coagulation of living tissue by microwave irradiation at an appropriate timing.

[0009]

In order to achieve the above-mentioned object, in a microwave operation apparatus of the present invention, a sensor section for detecting at least one of a reflected wave and a traveling wave of a microwave output of a main body apparatus. ,

An end discriminating means for discriminating the end of coagulation of the living tissue by monitoring at least one of the level and the waveform of the detection wave of the sensor unit during the output of the microwave of the main body device,

Output termination means for stopping the microwave output of the main body apparatus by the termination determination of the termination determination means is provided.

Then, as the coagulation of the biological tissue due to the irradiation of the microwave progresses, the load impedance of the main body device with respect to the microwave output changes, and the traveling wave and the reflected wave of the main body device change. The level and waveform of the detected wave change as the coagulation progresses.

Therefore, the level of the detection wave of the sensor section,
By monitoring at least one of the waveforms, the termination determination means determines the termination of coagulation at an appropriate timing according to the condition of the living tissue.

Based on this determination, the output stopping means stops the microwave output of the main body device, so that the coagulation of the living tissue by the microwave irradiation is automatically terminated at an appropriate timing.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the overall configuration, in which a coaxial cable 2 is connected to a main body device 1 so that the coaxial cable 2 can be connected and detached, and a monopolar surgical electrode 3 of various shapes such as a needle shape and a blade shape is exchanged at the tip of the coaxial cable 2. Connector can be freely connected. When the surgical electrode 3 is needle-shaped or the like, the tip thereof is inserted into the living tissue, and when the surgical electrode 3 is blade-shaped or the like, the tip of the surgical blade is brought into contact with the biological tissue.

On the other hand, the operating conditions (irradiation conditions) such as the magnitude of microwave and tissue dissociation current (output), output time, etc. are designated by operating various setting knobs of an operation section (not shown) of the main body device 1. Then, the output times of the microwave and the tissue dissociation current are preset in the output time setting section 5 which operates as a timer via the output control section 4 having a function of outputting various contact signals.

Further, the output of the microwave generator 6 is variably set in the range of, for example, 10 to 110 W according to the designation of the magnitude of the microwave, and the direct current for the dissociation current is designated according to the designation of the magnitude of the tissue dissociation current. The output of the power supply 7 or the dissociation current setting unit 8 connected to the power supply 7 is variably set.

When the starting switch 9 of the main body 1 such as a foot switch is turned on, the timer for microwave irradiation of the output time setting section 5 is started and the output control section 4 causes the power source section of the microwave generator 6 to operate. 10, the power source unit 10 processes the input power source of the power receiving terminal 11 into a power source for microwave oscillation, such as a high-voltage power source, and supplies the power source to the oscillating unit 12.

By this feeding, the oscillator 12 generates a microwave MW of 2450 MHz of a set size, and this microwave MW is transmitted to the coaxial cable 2 via the cavity resonator 13, the mixer 14 and the sensor unit 15. The microwave of the cable 2 is output and supplied to the surgical electrode 3.

Then, the surgical electrode 3 focuses and irradiates the living tissue with the microwave MW, and the living tissue near the surgical electrode 3 is coagulated by the dielectric heat energy based on this irradiation.

By the way, the mixer 14 is composed of a microwave filter or the like, and mixes the microwave MW with the DC tissue dissociation current DC of the dissociation current setting section 8 and outputs the mixed result.

Further, the sensor section 15 is provided at the final stage output section of the main body apparatus 1 in order to detect at least one of the reflected wave R and the traveling wave T of the microwave output of the main body apparatus 1, and a so-called standing wave ( SWR) measuring device, in which both the reflected wave R and the traveling wave T are constantly detected.

Then, the output of the detection wave (reflected wave R, traveling wave T) of the sensor section 15 is supplied to a discrimination processing section 16 of a microcomputer structure forming an end discrimination means. The proper end timing of solidification is determined based on the output monitoring.

Next, the discrimination processing of the processing unit 16 will be described. First, the change in the reflected wave R and the traveling wave T based on the microwave irradiation of the surgical electrode 3 and the proper end timing of coagulation will be described.

When the living tissue is irradiated with the microwave MW of the surgical electrode 3, the coagulation progresses to cause the disappearance of water (such as body fluid) and the like, thereby changing the load impedance of the main body device 1 and reflecting the microwave output. The levels of the wave R and the traveling wave T (peak voltage) and their waveforms change.

The level and waveform change characteristics differ depending on the shape of the surgical electrode 3 such as the length of the needle that influences the microwave irradiation position (location) and the site of the biological tissue. In this case, when the surgical electrode 3 has the following three types of shapes A, B, and C, the change characteristics of the reflected wave R are almost the same as the measurement results of (a), (b), and (c) of FIG. As shown.

Type A: 15 mm length needle type for laparotomy 15 mm electrode Type B: 30 mm length needle type for laparotomy 30
mm Electrode Type C: Deeper transcutaneous transhepatic electrode with a larger diameter (1.6 mm diameter) than Types A and B

Then, as is clear from FIGS. 2A, 2B, and 2C, when 15 seconds have elapsed from the start of irradiation,
Irrespective of the electrode shape, the transient change is almost completed, and the type of the surgical electrode 3 can be discriminated from the waveform of the reflected wave R.

Further, surgical electrodes 3 of each type A, B, C
Therefore, as a result of repeating the experiment by measuring the reflected wave R, it was found that in the case of each type A, B, C, the appropriate end timing of the coagulation is as follows.

That is, in the case of type A, when the level of the reflected wave R becomes equal to 2 seconds before 15 seconds after the start of irradiation of the microwave MW, a predetermined time (5 seconds)
After the lapse of the above, the level of the reflected wave R is kept below the level slightly (0.2 V) higher than the level 5 seconds before, and when a predetermined time (10 seconds) has passed from this state,
It is the proper end timing of solidification.

In the case of type B, the microwave MW
After the lapse of 30 seconds from the start of the irradiation of No. 3, when the level of the reflected wave R becomes equal to or higher than a predetermined voltage (2V), the appropriate end timing of coagulation is reached.

Further, in the case of type C, the microwave M
When the level of the reflected wave R becomes higher than 2 seconds after 15 seconds have elapsed from the start of W irradiation, a predetermined time (5 seconds)
After the lapse of the above, the level of the reflected wave R becomes higher than the level of 5 seconds before by a predetermined amount (0.1 V) or more, and when a predetermined time (10 seconds) elapses from this state, the coagulation ends properly. Become.

Therefore, for the surgical electrodes 3 of types A and C, the proper end timing of coagulation can be determined by monitoring the waveform of the reflected wave R (time change of level), and for the surgical electrodes 3 of type B. By monitoring the current level of the reflected wave R, it is possible to determine the proper end timing of coagulation.

Further, the start of the irradiation of the microwave MW can be grasped from the fact that the level of the traveling wave T becomes a constant value (2 V) or more, for example.

Therefore, the discrimination processing unit 16 uses the start switch 9
When the output control unit 4 notifies that the switch is turned on, as shown in FIGS.
The discrimination processing program of FIG. 5 is executed, and first, in step S1 of FIG. 3, the process waits until the peak voltage of the traveling wave T becomes 2 V or more, and detects the start of irradiation of the microwave MW.

When this irradiation start is detected,
The internal timer counter is initialized in step S2 to immediately start the time counting operation, and waits for 15 seconds to elapse in step S3.

After the lapse of 15 seconds, the process proceeds to step S4, the waveform of the reflected wave R is compared with the reference waveform of each type A, B, C previously stored in the internal memory or the like, and the closest reference waveform is obtained. Then, the type of the surgical electrode 3 is determined.

By the way, the reference waveform is a typical waveform of each type when 15 seconds have elapsed from the start of irradiation, for example, for type B, the waveform as shown in FIG. 2 (a), (b) of FIG.
It is the waveform of the change characteristic as shown in (c).

When the type of the surgical electrode 3 is discriminated, the process is branched according to this discrimination, and in the case of the simplest type B discriminated from the current level of the reflected wave R, the process proceeds from step S4 to step S5. And then 1
After waiting for 5 seconds, when 15 seconds have passed and 30 seconds have passed from the start of irradiation, it is repeatedly determined in step S6 whether or not the positive peak voltage of the reflected wave R has risen to 2 V or higher.

At this time, the waveform of the reflected wave R changes as the coagulation progresses, for example, as shown in FIGS. 6 (b) and 6 (c), and FIG. 6 (b) shows the waveform during coagulation 30 seconds after the start of irradiation. , (C) are waveforms at the timing of ending the coagulation.

As is clear from FIGS. 6A, 6B and 6C, in the case of the type B surgical electrode 3, the level of the reflected wave R immediately after the type discrimination is shown in FIG. ), The reflected wave R lowers in level due to a decrease in water, and its peak voltage becomes smaller than 2 V as shown in (b) of the figure. Therefore, the level of the reflected wave R rises, and the peak voltage at the end is raised to 2 V or higher as shown in FIG.

If microwaves are further applied from the state shown in FIG. 6C, the state becomes an over-coagulated state, which causes adverse effects such as carbonization of living tissue.

When the peak voltage of the reflected wave R rises to 2V and the coagulation finishes at an appropriate timing, the process shifts from step S6 to step S7 and the output controller 4 is notified of the stop of the microwave output. Then, the power supply unit 10 is turned off by the output stopping unit of the output control unit 4, and the microwave output of the main body device 1 is automatically stopped.

Further, the notification device 17 of the main body device 1 is notified of the end notification via the output control unit 4, and the notification device 17 sounds a buzzer sound, a voice message or the like or lights the lamp. The end of coagulation (end of microwave irradiation) is notified by light such as a message of letters or figures.

On the other hand, in the case of type A, step S in FIG.
4 to step S8 in FIG. 4, the peak voltage of the reflected wave R at the time of type discrimination, that is, 15 seconds after the start of microwave irradiation is held in the internal register R ₀ .

Further, in steps S9 and S10, it is judged whether or not the peak voltage of the reflected wave R after 2 seconds is equal to the holding voltage of the register R ₀ , and 4 to 4 from the irradiation start of FIG. Identify whether the level increase due to a transient change such as during 8 seconds has ended.

Then, until the peak voltage of the reflected wave R after 2 seconds becomes equal to the value held in the register R ₀ , step S8,
The processing of S9 and S10 is repeated, and the peak voltage of the reflected wave R is monitored while updating the value held in the register R ₀ .

Next, when the peak voltage of the reflected wave R after 2 seconds becomes equal to the value held in the register R ₀ , step S10
From step S11 to step S11, wait for a further 5 seconds. When this 5 seconds elapses, step S12 determines whether the current peak voltage of the reflected wave R is 0.2 V higher than the value held in the register R ₀ or less. Whether or not it is determined, the process returns to step S10 until this state is reached, and the processing from step S10 is repeated.

When the current peak voltage of the reflected wave R becomes 0.2 V higher than the value held in the register R ₀ or less and becomes almost unchanged, the process proceeds to step S13 and waits for 10 seconds, When 10 seconds have passed and an appropriate end timing of coagulation is reached, the process proceeds to the end of coagulation in step S14, the microwave output is stopped and the end of coagulation is notified in the same manner as in step S7.

Next, in the case of type C, the process proceeds from step S4 in FIG. 3 to step S15 in FIG. 5, and as in step S8 in FIG. 4, the reflected wave 15 seconds after the start of microwave irradiation starts due to this step S15. The peak voltage of R is held in the internal register R ₀ .

Further, in steps S16 and S17, 2
The peak voltage of the reflected wave R when the second has elapsed is the register R _0.
It is discriminated whether or not the voltage has become larger than the holding voltage of (1), and it is discriminated whether or not it has reached the level gradual increase state after the elapse of 25 seconds in (c) of FIG.

Then, the processes of steps S15, S16, and S17 are repeated until the gradual increase state is reached, and the register R
The peak voltage of the reflected wave R is monitored while the held value of ₀ is updated.

Next, in the gradually increasing state, the process proceeds from step S17 to step S18 and waits for 5 seconds to elapse. When this 5 seconds elapses, the current peak voltage of the reflected wave R is registered in step S19. It is determined whether or not the value held by R ₀ is higher by 0.1 V or more, and the process returns to step S17 until this state is reached.
Repeat the process from 7.

When the current peak voltage of the reflected wave R becomes higher than the value held in the register R ₀ by 0.1 V or more, the process shifts to step S20 and waits for 10 seconds.
When 0 seconds has passed and the appropriate end timing of solidification is reached,
The process proceeds to the end of solidification in step S21, and steps S7 and S
Similarly to 14, the microwave output is stopped and the end of coagulation is notified.

Therefore, regardless of the type of the surgical electrode 3, the coagulation by microwave irradiation is automatically terminated at an appropriate end timing, and the occurrence of overcoagulation or the like is surely prevented and the operability and the functionality are remarkably improved. improves.

Even if the microwave irradiation continues until the time set by the timer for some reason as in the case of FIG. 2B, output control is performed based on the time-up notification of the output time setting unit 5. The unit 4 turns off the power supply unit 10 to stop the microwave output of the main body device 1.

During the microwave irradiation, the start switch 9
When is turned on again, the output control unit 4 immediately turns off the power supply unit 10 to stop the microwave output. Therefore, sufficient safety is secured.

Next, when the microwave irradiation is finished, the output control unit 4 activates the timer for the dissociation current of the output time setting unit 5, and the output is turned on to the dissociation current setting unit 18 via the setting unit 5. Is commanded, and the process automatically shifts to tissue dissociation.

At this time, a DC tissue dissociation current DC of a size set in the living tissue is supplied from the DC power source 7 through the dissociation current setting unit 8, the mixer 14, the sensor unit 15, the coaxial cable 2 and the surgical electrode 3. The supplied dissociation current DC utilizes the electroosmotic effect of the living body to soften the tissue adhering to the surgical electrode 3 and dried, thereby facilitating the withdrawal of the surgical electrode 3 from the living body.

When the output time setting unit 5 is up, the output control unit 4 commands the dissociation current setting unit 18 to turn off the output, and the supply of the tissue dissociation current DC is automatically terminated. Will be notified by.

Desired hemostasis and coagulation of the living body can be performed by shifting the position of the surgical electrode 3 to be inserted and repeating the microwave irradiation and the dissociation of the biological tissue as described above a required number of times.

By the way, the type of surgical electrode used is 1
In the case where it is fixed to one, for example, the determination in step S4 of FIG. 3 becomes unnecessary.

Instead of monitoring the level or waveform of the reflected wave R, the level or waveform of the traveling wave T may be monitored to automatically stop the microwave output.
The microwave output may be automatically stopped by monitoring both levels or waveforms of the traveling wave T.

At this time, since the level and the waveform which are the reference for discrimination are different depending on the shape of the surgical electrode 3 and the surgical site of the living tissue, the change characteristics of the reflected wave R and the traveling wave T under the conditions applied in advance by experiments or the like. Can be measured and the reference level and waveform required for discrimination can be set in the discrimination processing unit 16 or the like. And, it goes without saying that the discrimination procedure and the like may be different from those in FIGS.

The output control section 4 and the like shown in FIG. 1 may have any configuration. For example, the output control section 4, the output time setting section 5, the discrimination processing section 16 and the like are formed by one microcomputer. It is also possible to do so.

Further, the present invention can be similarly applied to the case of so-called simultaneous irradiation in which one microwave irradiation is performed by superposing the microwave output on the tissue dissociation current intermittently or continuously.

[0067]

The present invention has the following effects. The load impedance of the main body device 1 with respect to the microwave output changes as the biological tissue coagulates due to the irradiation of microwaves, and the traveling wave and the reflected wave of the microwave of the main body device 1 change. And the waveform change according to the progress of the coagulation, and based on the monitoring of at least one of the level and the waveform of the detection wave of the sensor unit 15, the termination determination means terminates the coagulation at an appropriate timing according to the condition of the living tissue. Can be determined.

Since the output stopping means stops the microwave output of the main body apparatus 1 based on this determination, the coagulation of the living tissue by the microwave irradiation can be automatically terminated at an appropriate timing, so-called overcoagulation. It is possible to reliably prevent the occurrence of, and it is possible to significantly improve operability and functionality.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a characteristic diagram of changes in the level of a reflected wave for each type of surgical electrode.

FIG. 3 is a first flowchart for explaining the operation of the determination processing unit in FIG.

FIG. 4 is a second flowchart for explaining the operation of the determination processing unit in FIG.

FIG. 5 is a third flowchart for explaining the operation of the determination processing unit in FIG.

6 (a), (b), and (c) are explanatory views of an example of a waveform change of the reflected wave in FIG.

[Explanation of symbols]

 1 Main device 2 Coaxial cable 3 Surgical electrode 4 Output control unit 5 Output time setting unit 6 Microwave generator 15 Sensor unit 16 Discrimination processing unit

Claims (1)

[Claims] 1. A main body device for outputting a microwave, and a surgical electrode which is connected to the main body device by a cable and is inserted into a living tissue, and the living tissue is irradiated with the microwave to coagulate the living tissue. And a sensor unit that detects at least one of a reflected wave and a traveling wave of a microwave output of the main body device, and a detection of the sensor unit during the output of the microwave of the main body device. An end determination means for determining at least one of the wave level and the waveform to determine the end of the coagulation, and an output stop means for stopping the microwave output of the main body device by the determination of the end of the end determination means are provided. A microwave surgical device characterized in that