JP2001231791A - Electrosurgical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the carbonization of a living tissue and the adhesion of it to an operation instrument (electrode) by surely judging the end of a coagulation treatment regardless of contact area of the living tissue with the electrode holding the tissue and the thickness of the tissue which is held by the operation instrument (electrode). SOLUTION: A control part decides a maximum current value Imax as a first target value so as to permit output power to be a previously set initial setting value. Then the thickness (t) of the tissue 4a and the contact area A of the tissue 4a with the electrode 3 holding the tissue is obtained through the use of the combination (Imax, T) of Imax and a time T required till the value becomes Imax. The combination (A, t) of the obtained contact area A with the thickness (t) of the tissue is compared with the combination (Aset, tset) of the contact area Aset and the thickness tset of the initial setting value. Then the subsequent output of high frequency power and a coagulation end current value as a second target value are decided by the comparison result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrosurgical apparatus, and more particularly, to an electrosurgical apparatus having a high-frequency current output control portion.

[0002]

2. Description of the Related Art Generally, an electrosurgical device such as an electric scalpel is
It is used when performing procedures such as incision of living tissue and coagulation and hemostasis in a surgical operation or a medical operation. Such an electrosurgical apparatus includes a high-frequency ablation power supply device that generates a high-frequency current, and a surgical tool connected to the high-frequency ablation power supply device. A high-frequency current is supplied to the living tissue from the device via a surgical tool, and the living tissue is subjected to a treatment such as incision and coagulation hemostasis.

Various types of electrosurgical devices have been proposed in the past. For example, the electrosurgical device described in Japanese Patent Application Laid-Open No. 8-98845 prevents carbonization of a living tissue to be coagulated and applies the living tissue to an electrode. In order to prevent the adhesion, it has been proposed that the end of the coagulation treatment is determined from the tissue impedance and the output of the high-frequency current is stopped.

Further, in the electrosurgical apparatus described in Japanese Patent Application Laid-Open No. 10-225462, after determining the end of coagulation treatment, the output of the high-frequency current is reduced without stopping, and after determining the end of coagulation, the operator If it is determined that the coagulation treatment is insufficient, a treatment that can continue the treatment has been proposed. In addition, when the coagulation treatment is continued, since the output of the high-frequency current is reduced, the speed of degeneration of the living tissue is slow, and the operator may end the treatment when a desired coagulation state is obtained. It is possible.

[0005]

Generally, the smaller the contact area between a living tissue and an electrode which is a surgical tool for gripping the living tissue, the faster the change in tissue impedance of the living tissue.

For this reason, the electrosurgical apparatus described in the above-mentioned JP-A-8-98845 and JP-A-10-225462 has a small contact area between a living tissue and a surgical tool (electrode) for gripping the living tissue. In this case, there is a possibility that carbonization of the living tissue and attachment of the living tissue to the surgical tool (electrode) may occur while the measurement of the tissue impedance and the determination of the end of the coagulation treatment are being performed. Further, Japanese Patent Laid-Open No. 10-22 / 1990
In the electrosurgical apparatus disclosed in Japanese Patent No. 5462, when the contact area between a living tissue and a surgical tool (electrode) for gripping the living tissue is small, or when the thickness of the living tissue gripped by the surgical tool (electrode) is small, The speed of denaturation of the living tissue has been increased, and it has been difficult for the operator to end the treatment when a desired coagulation state is obtained. In addition, when the contact area is large, when the thickness of the living tissue gripped by the surgical instrument (electrode) is large, the speed of denaturation of the living tissue becomes excessively slow, and the time until a desired coagulation state is obtained is long. There was a problem of becoming.

The present invention has been made in view of the above circumstances, and has a contact area between a living tissue and a surgical tool (electrode) for gripping the living tissue and a thickness of the living tissue gripped by the surgical tool (electrode). Regardless of this, an object of the present invention is to provide an electrosurgical apparatus capable of reliably determining the end of coagulation treatment and preventing carbonization of a living tissue and attachment of the living tissue to a surgical tool (electrode).

[0008]

To achieve the above object, an electrosurgical apparatus according to the present invention comprises a treatment energy generating means for supplying treatment energy to a surgical instrument, and a variable means for varying the output of the treatment energy generating means. Detecting means for detecting a physical quantity of the treatment energy supplied from the treatment energy generating means to the living tissue via the surgical tool; and detecting the predetermined change amount from the start of the output of the treatment energy generating means. Measuring means for measuring the time until the measurement, and control means for controlling the variable means based on the detection result of the detecting means and the measuring time of the measuring means. With this configuration, it is possible to reliably determine the end of the coagulation treatment regardless of the contact area between the living tissue and the electrode holding the living tissue and the thickness of the living tissue gripped by the surgical tool (electrode). An electrosurgical apparatus capable of preventing carbonization and attachment of a living tissue to a surgical tool (electrode) is realized.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 7 relate to a first embodiment of the present invention, and FIG. 1 is an external configuration illustrating an overall configuration of an electrosurgical apparatus according to the first embodiment of the present invention. FIG. 2 is a circuit block diagram showing the configuration of the high-frequency ablation power supply of FIG. 1, FIG. 3 is a flowchart showing the control flow of the control unit shown in FIG. 2, and FIG. 4 is a front view when the electrode grips the tissue. , FIG.
Is a top view when the electrode grips the tissue, FIG. 6 is a first graph illustrating the operation of the high frequency power supply, and FIG. 7 is a second graph illustrating the operation of the high frequency power supply.

As shown in FIG. 1, an electrosurgical instrument 1 according to the present embodiment includes a high-frequency ablation power source 2 and a pair of surgical tools for supplying a high-frequency current from the high-frequency ablation power source 2 to a living tissue 4 a of a patient 4. And the main electrode 3. Also,
The high frequency ablation power source 2 has a high frequency current ON / OFF.
A foot switch 5 for controlling is connected.

As shown in FIG. 2, the pair of electrodes 3 grip a living tissue 4a of a patient 4 to supply a high-frequency current to the living tissue 4a having a thickness t held by the electrode 3. . As shown in FIG. 5, the contact area between the living tissue 4a and the electrode 3 holding the living tissue 4a at this time is represented by A.

[0012] As shown in FIG.
Is a DC power supply circuit 21 for supplying a DC current, a high frequency generation circuit 22 for converting the DC current from the DC power supply circuit 21 to a high frequency current, and a waveform generation circuit for controlling the waveform of the high frequency current for the high frequency generation circuit 22. Circuit 23 and the high-frequency current from the high-frequency generation circuit 22 to the pair of electrodes 3.
And an output transformer 24 for outputting the output
A current sensor 25 as detection means for detecting an output current output from the A / D converter 26 for A / D converting a current value detected by the current sensor 25;
The control unit 27 controls the DC power supply circuit 21 and the waveform generation circuit 23 based on the current data digitized by the D converter 26.

The control unit 27 includes a timer 27a as a measuring means for measuring the time from the start of output to the time when the current supplied to the living tissue reaches the maximum current value Imax, and the time T measured by the timer 27a. From the combination (Imax, T) with the maximum current value Imax, the thickness t of the living tissue 4a is calculated.
R that stores table data (A, t) to be described later for obtaining a contact area (hereinafter simply referred to as a contact area) A between the living tissue 4a and the electrode 3 holding the living tissue 4a.
OM27b.

Next, the operation of the control unit 27 will be described with reference to FIGS. 6 and 7 and the flowchart shown in FIG. First, the living tissue 4a of the patient 4 is gripped by the pair of electrodes 3, and the foot switch 5 is turned on. Foot switch 5
Is stepped on, the control unit 27 sets the maximum current value Imax and the time T to 0 in step S1, and starts measuring the time from the start of the output to the maximum current value Imax by the timer 27a. Next, in step S2, the DC power supply circuit 21 is set so that the output power becomes the preset initial value.
The waveform generator 23 is controlled. Here, the time change between the high-frequency power and the high-frequency current is, for example, as shown in FIG. 6 or FIG.

Generally, the high-frequency current rises immediately after the start of output, but then falls sharply. As a result, the living tissue 4a is heated while the high-frequency current is rising, and when the temperature of the living tissue 4a reaches the boiling point, the moisture present in the living tissue 4a evaporates and the resistance value increases. It is expected that the current value will decrease.

Here, at the time T = 0, the high-frequency power is output according to the initial set value. After this, step S
Steps S3 to S6 are repeated to determine the maximum current value Imax as the first target value of the high-frequency current, and to measure the time from the start of the output until reaching the maximum current value Imax.

In step S3, the high-frequency current is detected by the current sensor 25, and the detected current value is converted by the A / D converter 26.
Is converted to digital data. The current value converted into the digital data is passed to the control unit 27 as the current value I. Then, the control unit 27 performs a maximum value determination for obtaining a maximum current value (first target value) Imax of the current in step S4. Details of the operation in step S4 are shown in steps S5 and S6.

In step S5, the maximum current value Ima up to the previous time is
The magnitude of x and the current value I measured this time are compared. If the current value I is larger than the previous maximum current value Imax, the value of Imax is replaced with I in step S6, the time T is stored, and the process returns to step S3. This is repeated until the current value I falls below the previous maximum current value Imax.

On the other hand, the current value I is the maximum current value I up to the previous time.
If it is less than max, it means that the current maximum current value (first target value) Imax has been determined, and the routine proceeds to step 7.
In step S7, the control unit 27 uses the Imax and the time T required to reach the Imax (hereinafter simply referred to as time) T to obtain the thickness t and the contact area A of the living tissue 4a according to Table 1 below.
Ask for.

The details of the operation in step S7 will be described below. Generally, the resistance value R is inversely proportional to the area A, is proportional to the length (thickness) t, and the current I is inversely proportional to the resistance R. R∝l / A, R∝1 / I (1) Further, the constitution V of the living tissue 4a sandwiched between the electrodes 3
Is determined by the product of the area A and the thickness t. V = A × t (2) The amount of energy at which the normal tissue per unit volume undergoes protein denaturation is determined by the product of the output W and the time T, and T∝V∝A × t (3) ) Is obtained.

In the present embodiment, based on the combination (Imax, T) of the maximum current value Imax and the time T, the control unit 27 can easily determine the thicknesses t1 to t of the three types of living tissue 4a.
3 and the table data relating to the contact areas A1 to A3 (A
1 to A3, t1 to t3) in the ROM 27b, and the table data (A1 to A3, t1 to t3) stored in the ROM 27b have the following relationships.

[0022]

[Table 1] In Table 1, the combination of the contact area A2 and the thickness t2 of the living tissue 4a (A2, t2) is a predetermined initial value as a reference value of the combination (Imax, T) of the maximum current value Imax and the time T. (Aset, tset), and using (A2, t2) as a reference value, the following relationship is obtained. t1: t2: t3 = 1/2: 1: 2, A1: A2: A3 = 1/2: 1: 2, I = A2 / t2, V = A2 × t2 (4) From Table 1, Using the combination (Imax, T) of the maximum current value Imax and the time T, the combination (A, T) of the current contact area A and the thickness t of the living tissue 4a can be known. For example, when the current value is I and the time is 4T (I, 4T), from Table 1, the contact area is A3 and the thickness is t3.
That is, (A3, t3).
The graph shown in FIG. 6 is for the case of (A3, t3). As another example, when the current value is I and the time is 0.25T (I, 0.25T), from Table 1, the contact area is A1 and the thickness is t1, that is, (A1,
t1). The graph shown in FIG. 7 is for the case of (A1, t1).

In step S8, a comparison between the obtained combination (A, t) of the contact area A and the thickness t of the living tissue 4a and the combination (Aset, tset) of the contact area Aset and the thickness tset of the initial set value are performed. The comparison result (A <
Aset ort <tset), the subsequent output of the high-frequency power and the setting of the coagulation completion current value as the second target value are set to 2
The output is reset or the coagulation completion current value as the second target value is determined for each system.

Here, the respective cases of the graphs of FIGS. 6 and 7 will be described. First, (A3, t3) in FIG.
The case will be described. In the case of (A3, t3) in FIG. 6, the contact area and the thickness are respectively set to the initial set values (Ase
t, tset), the process proceeds to step S9. In step S9, the obtained contact area A3 and thickness t
The output is reset according to the combination of (A3, t3). In this case, the output remains the set output. next,
In step S10, the obtained contact area A3 and thickness t3
The solidification completion current value (second target value) If is set based on the combination (A3, t3). In this case, If = I
max x 70%.

On the other hand, in the case of (A1, t1) in FIG.
The contact area and thickness are initially set values (Aset, tse
Since it is 1/2 of t), the process proceeds to step S11. In step S11, the output is reset to the set output × 50% based on the combination (A1, t1) of the obtained contact area A1 and thickness t1. Then, in step S12, the coagulation completion current value If = Imax × 50%.

Here, the output and the coagulation completion current value are reduced for the following reasons. Small contact area,
When the thickness is thin, the grasped tissue is heated rapidly after Imax, and the water in the tissue evaporates immediately, so that the tissue is not carbonized or the electrode 3 is prevented from adhering to the tissue. Output for a long time.

Thereafter, in step S13, the current value I is measured again, and the current value I is determined as the solidification completion current value (second target value).
The current value I is compared with the coagulation completion current value If in step S14 until the current value I falls below the coagulation completion current value If. If the current value I is smaller than the coagulation completion current value If, the biological tissue 4a grasped by the electrode 3 in step S15. It is considered that the coagulation has been completed, the power is reduced by 50%, and the process ends (step S16).

As a result, in order to recognize the contact area and the thickness between the electrode 3 and the tissue based on the change in the high-frequency current, the end of coagulation is reliably determined under any conditions, and the carbonization of the living tissue 4a and the living tissue 4a are performed. To the electrode 3 can be prevented.

In the present embodiment, the subsequent output of the high-frequency power and the setting of the coagulation completion current value are described as two systems based on the contact area and the thickness, but the present invention is not limited to this. Further, in the present embodiment, using Table 1,
The contact area and thickness were determined, and A = f (Imax,
T), t = g (Imax, T) may be given and an approximate expression may be calculated from this approximate expression. As for the change in the current value, an average value of several times may be used in order to perform the measurement more accurately. In addition, in the present embodiment, the output after the completion of solidification is set to 50%, but the output is not limited to this value and may be 100% or less.

In this embodiment, the physical quantity detecting means is a current sensor. However, the present invention is not limited to this, and a voltage sensor or a combination of a current sensor and a voltage sensor may be used.

(Second Embodiment) FIGS. 8 to 10 relate to a second embodiment of the present invention, and FIG.
FIG. 9 is a first graph for explaining the operation of the high-frequency power supply, and FIG. 10 is a second graph for explaining the operation of the high-frequency power supply.

In the first embodiment, the contact area and the thickness are determined using the current value detected from the high-frequency current, and the output of the high-frequency power and the setting of the solidification completion current value as the second target value are performed. In the second embodiment, the contact area and the thickness are obtained by using the impedance (hereinafter, resistance) value instead of the current value. For other configurations,
The description is omitted because it is almost the same as the first embodiment,
The operation of the control unit 27 will be described with reference to FIGS. 9 and 10 and according to the flowchart shown in FIG.

First, the living tissue 4a of the patient 4 is gripped by the pair of electrodes 3, and the foot switch 5 is turned on. When the foot switch 5 is depressed, the control unit 27 sets the minimum resistance value Zmin to 100 and the time T to 0 in step S21, and starts measuring the time from the output start to the minimum resistance value Zmin by the timer 27a. I do. Next, step S2
In step 2, the DC power supply circuit 21 and the waveform generation circuit 23 are controlled so that the output power becomes a preset initial value.
Here, the time change between the high-frequency power and the resistance is, for example, as shown in FIG.
Or it is as shown in FIG.

In general, the resistance once drops immediately after the start of output, but rises sharply as human tissue dries due to heating. Here, at the time point T = 0, the high-frequency power is output according to the initial set value. After this, step S
Steps S26 to S26 are repeated to determine the minimum resistance value Zmin as the first target value, and to measure the time from the start of the output until the minimum resistance value Zmin is reached.

In step S23, the high-frequency current is detected by the current sensor 25, and the detected current value is output from the A / D converter 2
At step 6, it is converted into digital data. The current value converted into the digital data is passed to the control unit 27 as the current value I. Then, the control unit 27 obtains the resistance value Z from the set output and the current value I, and performs a minimum value determination for obtaining a minimum resistance value (first target value) Zmin in step S24.

As described above, the change in the resistance value is almost the same as the change in the current value described in the first embodiment.
The thickness t and the contact area A of the living tissue 4a are obtained from Table 2 below according to the movement described in the flowchart of FIG.

[0037]

[Table 2] In Table 2, as a reference value of the combination (Zmin, T) of the minimum resistance value Zmin and the time T, a combination of the contact area A2 and the thickness t2 of the living tissue 4a (A
, T2) to a predetermined initial set value (Aset, tse)
t), and (A2, t2) is used as a reference value. From Table 2, the current contact area A and the thickness t of the living tissue 4a can be known using the minimum resistance value Zmin and the time T.

In step S28, the obtained contact area A
And a combination (A, t) of the thickness t of the living tissue 4a,
The initial set value is compared with a combination (Aset, tset) of the contact area Aset and the thickness tset, and the comparison result (A <
Aset ort <tset), the subsequent output of the high-frequency power and the setting of the coagulation completion resistance value as the second target value are set to 2
The output is reset or the solidification completion resistance value as the second target value is determined for each system.

Here, each case of the graphs of FIGS. 9 and 10 will be described. First, (A3, t
The case 3) will be described. In the case of (A3, t3) in FIG. 9, the process proceeds from step S28 to step S29, and the output is reset in step S29. In this case, the output remains the set output. Next, step S1
At 0, the solidification completion resistance value (second target value) Zf is set. In this case, Zf = Zmin × 140%. On the other hand, in the case of (A1, t1) in FIG.
Then, the process proceeds from step S31 to step S31. In step S31, the output is reset to the set output × 50%. Then, in step S32, the solidification completion resistance value Zf is set to Zf = Zmin × 200%.

Thereafter, in step S33, the resistance value Z is measured again, and the resistance value Z is determined as the solidification completion resistance value (second target value).
Until the value exceeds Zf, the resistance value Z is compared with the coagulation completion resistance value Zf in step S34. When the resistance value Z exceeds the coagulation completion resistance value Zf, in step S35, the biological tissue 4a grasped by the electrode 3 is removed. It is considered that the coagulation has been completed, the power is reduced by 50%, and the process ends (step S36).

As a result, in the same manner as in the first embodiment, the contact area and the thickness between the electrode 3 and the tissue are recognized on the basis of the change in the resistance. Carbonization of the tissue 4a and attachment of the living tissue 4a to the electrode 3 can be prevented.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[Appendix] (Appendix 1) Treatment energy generating means for supplying treatment energy to the surgical instrument, variable means for varying the output of the treatment energy generating means, and the treatment energy generating means via the surgical instrument Detecting means for detecting a physical amount of the treatment energy supplied to the living tissue, measuring means for measuring a time from the start of the output of the treatment energy generating means to the detection means detecting a predetermined amount of change, An electrosurgical apparatus comprising: a control unit that controls the variable unit based on a detection result of the unit and a measurement time of the measuring unit.

(Additional Item 2) The electrosurgical apparatus according to Additional Item 1, wherein the physical quantity detected by the detection means is a current value, a voltage value, or an impedance value.

(Additional Item 3) The control means determines the first target value by a predetermined function from the detection value detected by the detection means, and the control means determines the first target value by the first target value determination means. The thickness of the living tissue gripped by the surgical tool and the contact area between the living tissue and the surgical tool are calculated based on the measured first target value and the measurement time required to reach the first target value measured by the measuring means. The electrosurgical apparatus according to claim 1, further comprising: a calculating unit configured to determine a second target value and an output of the high-frequency current based on a calculation result of the calculating unit.

(Additional Item 4) The electrosurgical apparatus according to Additional Item 1, wherein the detecting means is a current sensor, and a detection value detected by the current sensor is a current value.

(Additional Item 5) The electrosurgical apparatus according to additional item 1, wherein the detecting means is a voltage sensor, and a detection value detected by the voltage sensor is a voltage value.

(Additional Item 6) The above-mentioned detecting means is a voltage sensor and a current sensor, and the detection values detected by the voltage sensor and the current sensor are a voltage value and a current value. An electrosurgical device according to claim 1.

(Additional Item 7) The electrosurgical apparatus according to additional item 2, wherein the second target value is a hemostatic completion prediction point or a coagulation completion prediction point.

(Additional Item 8) As a result of the calculation by the calculation means, when the ratio of the thickness of the living tissue to the contact area of the living tissue gripped by the surgical tool is small, the output of the predetermined high-frequency current is lower than the predetermined output. 3. The electrosurgical apparatus according to claim 2, wherein the output is adjusted.

(Additional Item 9) As a result of the calculation by the calculating means, when the ratio of the thickness of the living tissue to the contact area of the living tissue gripped by the surgical tool is small, the predetermined output of the predetermined high-frequency current is lower. The electrosurgical apparatus according to claim 1, wherein the electrosurgical apparatus is adjusted so as to be output.

(Supplementary note 10) As a result of the calculation by the calculating means, when the ratio of the thickness of the living tissue to the contact area of the living tissue gripped by the surgical instrument is small, the time of the high-frequency current becomes long so that 2. The electrosurgical apparatus according to claim 2, wherein the target value is adjusted.

(Additional Item 11) The electrosurgical apparatus according to additional item 2, wherein the output of the high-frequency current is adjusted again after the physical quantity reaches the second target value.

[0054]

As described above, according to the present invention, the contact area between the living tissue and the surgical tool (electrode) holding the living tissue and the thickness of the living tissue gripped by the surgical tool (electrode) are determined. Without fail, the determination of the end of the coagulation treatment
Carbonization of the living tissue and attachment of the living tissue to the surgical tool (electrode) can be prevented. In addition, the speed at which the denaturation of the living tissue is degraded is maintained in a range where it can be easily determined, and the effect of easily determining the coagulation state is obtained.

[Brief description of the drawings]

FIG. 1 is an external configuration diagram illustrating an overall configuration of an electrosurgical apparatus according to a first embodiment of the present invention.

FIG. 2 is a circuit block diagram showing a configuration of the high-frequency ablation power source of FIG.

FIG. 3 is a flowchart showing a control flow of a control unit shown in FIG. 2;

FIG. 4 is a front view when an electrode grips tissue.

FIG. 5 is a top view when an electrode grips tissue.

FIG. 6 is a first graph illustrating the operation of a high-frequency power supply.

FIG. 7 is a second graph illustrating the operation of the high-frequency power supply.

FIG. 8 is a flowchart showing a control flow of a control unit having the second embodiment of the present invention.

FIG. 9 is a first graph illustrating the operation of a high-frequency power supply.

FIG. 10 is a second graph illustrating the operation of the high-frequency power supply.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electric surgery device 2 ... High frequency cautery power supply 3 ... Electrode (a pair of electrodes) 5 ... Foot switch 21 ... DC power supply circuit 22 ... High frequency generation circuit 23 ... Waveform generation circuit 24 ... Output transformer 25 ... Current sensor 26 ... A / D Converter 27 ... Control unit 27a ... Timer 27b ... ROM

Continued on the front page (72) Inventor Shinji Hatta 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Inventor Kenji Harano 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industrial Co., Ltd. F term (reference) 4C060 KK03 KK04 KK10 KK13 KK14 KK22 KK23 MM24

Claims (1)

[Claims] 1. A treatment energy generating means for supplying treatment energy to a surgical tool, a variable means for varying an output of the treatment energy generating means, and a treatment energy generating means which supplies the treatment energy to a living tissue via the surgical tool. Detecting means for detecting a physical quantity of the treatment energy, measuring means for measuring a time from the start of output of the treatment energy generating means until the detecting means detects a predetermined amount of change, a detection result of the detecting means, An electrosurgical apparatus comprising: a control unit that controls the variable unit based on a measurement time of the measurement unit.