JPH0663059A - High-frequency cautery device for medical treatment - Google Patents

Abstract

PURPOSE:To provide the high-frequency cautery device for medical treatment capable of making sure that an electrode catheter exists surely in the section to be cauterized by measuring the intracardiac potential in the state that the electrode catheter is in direct contact with a stimulus transmission system. CONSTITUTION:This high-frequency cautery device supplies a high-frequency current to the myocardium of the part to be cauterized and cauterizes the myocardium of the part to be cauterized by the Joule heat generated by the supplied high-frequency current. The above-mentioned device has a modulated high-frequency current generator 11 which generates the plural modulated high- frequency electric powers P including the very weak modulated high-frequency electric power as the modulated high-frequency electric power P formed by modulating a high-frequency electric power. An energization measuring means (arithmetic section) 19 which supplies the very weak modulated high-frequency current weaker than the high-frequency current to the myocardium prior to the cautery of the myocardium of the part to be cauterized and measures the current supplied in the myocardium at the time of energization is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical radiofrequency ablation device for treating heart diseases such as paroxysmal supraventricular tachycardia syndrome (PSVT) and refractory ventricular tachycardia (VT).

[0002]

2. Description of the Related Art Conventionally, paroxysmal supraventricular tachycardia syndrome (PSV)
In order to treat a heart disease such as T) or intractable ventricular tachycardia (VT), there is known a medical high-frequency ablation device that eliminates conduction abnormality in the stimulating conduction system of the heart and restores it to a normal state.

The stimulating conduction system consisting of a group of cells controls the contraction of the myocardium, which is the muscle forming the wall of the heart, and the sinoatrial node belonging to this stimulating conduction system acts as a pacemaker. Myocardial contraction occurs according to the generated electrical stimulation signal, and an automatic rhythm of the heart beat is generated.

By the way, paroxysmal supraventricular tachycardia syndrome (PS
Due to heart disease such as VT) or refractory ventricular tachycardia (VT)
There are cases where there are multiple stimulus sources that generate electrical stimulus signals or abnormal communication occurs in the stimulus conduction system, and the automatic rhythm of the heart beat may be disrupted.

In such a case, an electrode catheter is inserted into the heart, and an intracardiac potential (intracardiac potential) in each path of the stimulation conduction system is measured to detect an unnecessary electrical stimulation generation source or an abnormal conduction path. To do.

Then, high frequency power is supplied to the corresponding part of the detected unnecessary electrical stimulation generation source or abnormal conduction path through the electrode catheter so that the unnecessary electrical stimulation generation source or abnormal conduction path is supplied with high frequency power. It is cauterized by the generated Joule heat to cause coagulative necrosis, and is disconnected from the normal stimulation conduction system.

[0007] This method has the advantage that the physical burden on the patient is small because it can be treated by medical treatment without the need for conventional surgical operations.

[0008]

However, when cauterizing the corresponding site, the electrode catheter to which a high-frequency current is applied is positioned at the site corresponding to the cauterization based on the measured intracardiac potential. There was a problem that it was not possible to confirm whether or not it was located.

That is, in order to guide the electrode catheter to the site corresponding to ablation, the intracardiac potential measured by the electrode catheter is compared and contrasted with the known intracardiac potential. At this time, the electrode catheter directly contacts the stimulation conduction system. If, for example, the measurement is performed without a blood vessel, an accurate intracardiac potential cannot be obtained, and the electrode catheter cannot be reliably guided to the ablation corresponding site.

The present invention has been made in view of the above problems, and an object of the present invention is to measure an intracardiac potential in a state where the electrode catheter is in direct contact with the stimulating conduction system to obtain an electrode catheter. An object of the present invention is to provide a medical high-frequency ablation device capable of confirming that the abdomen is surely located at a site corresponding to ablation.

[0011]

In order to achieve the above object, a medical high-frequency ablation device according to the present invention applies a high-frequency current to an ablation myocardium of a heart via an electrode catheter to which high-frequency power is supplied. In a medical radiofrequency ablation device for cauterizing the ablation heart muscle by the Joule heat generated by the energized radiofrequency current, a plurality of modulated radiofrequency waves including weakly modulated radiofrequency power as the modulated radiofrequency power A modulation high-frequency power generator for generating power is provided, and a weak modulation high-frequency current is applied to the myocardium before cauterization of the ablation region myocardium, and an energization measuring means for measuring the energization current in the myocardium during energization is provided. It has a feature.

[0012]

With the medical high-frequency cautery apparatus according to the present invention,
Weakly modulated high-frequency power by inserting the electrode catheter supplied with the modulated high-frequency power generated by the modulated high-frequency power generator into the heart through the blood vessel of the patient and positioning it at the abnormal electrical stimulation source or conduction path that is the site to be cauterized. Apply current. The applied weak modulation high frequency current is measured by the energization measuring means and the resistance value in the myocardium is displayed. Based on the resistance value, it is confirmed whether or not the electrode catheter is surely in contact with the ablation site.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a medical high-frequency cautery device according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a medical high-frequency ablation device 10 has a modulated high-frequency power generator 11, a switch box 12, an electrode catheter 13 connected to the switch box 12, and a counter electrode plate 14. H is the patient to be treated.

The modulated high frequency power generator 11 has a CR oscillation modulator 15, a power amplifier 16, a selector 17, a voltage stabilizer 18, a calculator 19, a display 20, and an impedance controller 21.

The CR oscillation modulator 15 is a modulated high frequency signal generator having a CR oscillation modulator circuit 15a for generating a modulated high frequency signal, and generates a modulated high frequency signal of 450 KHz to 1000 KHz and outputs it to the power amplifier 16. .

The power amplifier 16 includes a power amplifier circuit 16a,
Low frequency filter 16b and DC component removal filter 1
6c, and the power amplifier circuit 16a power-amplifies the input modulated high-frequency signal into modulated high-frequency power P. It is output to the selection unit 17.

At the time of output, the modulated high frequency power P has different voltages to generate a weak current (weak modulated high frequency current) and an ablation current (modulated high frequency current) having the same waveform. The weak current is a current for measuring the impedance of the ablated part for specifying the ablation position, and the ablation current is a current for cauterizing the ablated part.

The modulated high frequency power P amplified by the power amplification is shown in FIG.
It has a modulation waveform as shown in (3) and enables power supply by soft start to prevent microshock when energized. From this power amplification unit 16, a maximum of 5
An output of 0 W is supplied.

The selection unit 17 has a selection switch 22. By operating the selection switch 22, the contact piece 22a is connected to the cauterization output terminal 22b, and the modulated high frequency power P for generating cauterization current is supplied to the voltage stabilizing unit. Cautery C to be output to 18,
Alternatively, the contact piece 22a is connected to the test output terminal 22c, and the modulated high frequency power P for generating a weak current is supplied to the voltage stabilizing unit 18.
The test T to be output to can be selected alternatively.

The selection switch 22 is selected for test T by turning on a test switch 41 described later, and is selected for cautery C by turning on a manual switch 44 described later.

The voltage stabilizing unit 18 has a voltage stabilizing circuit 18a. The modulated high frequency power P output from the selecting unit 17 is output to a stable state via the voltage stabilizing circuit 18a, and then the switch box. It is output to 12.

The switch box 12 has an electrocardiograph output (E
KG) and radio frequency output (RF) changeover switch 23, and a monopolar (Monop) of the electrode catheter 13 described later.
It has a change-over switch 24 for the polar and the bipolar.

The changeover switch 23 has two interlocking contact pieces 25a and 25b, electrocardiograph terminals 26a and 26b, and power terminals 27a and 27b, and the changeover switch 24 includes two interlocking contact pieces 28a and 28a. 28 b, an electrode catheter terminal 29, and a counter electrode terminal 30. The contact piece 25a and the contact piece 28a are connected, and the contact piece 25b and the contact piece 28b are connected. The electrode catheter terminal 29 has distal terminals 29a and 29b and a proximal terminal 29c. An electrocardiograph (not shown) is connected to the electrocardiograph terminals 26a and 26b.

By the switching operation of the changeover switch 23, the contact piece 25a and the electrocardiograph terminal 26a are brought into contact (at the same time, the contact piece 25b and the electrocardiograph terminal 26b are also brought into contact), and the contact piece 2
It is possible to select the electrode catheter output in which 5a and the power terminal 27a are brought into contact (at the same time, the contact piece 25b and the power terminal 27b are also brought into contact).

Further, by the switching operation of the change-over switch 24, the contact piece 28a and the distal terminal 29a are brought into contact with each other (the contact piece 28b and the proxy terminal 29c are also brought into contact with each other), and the contact piece 28a and the distal terminal 29b are brought together. It is possible to select the monopolar which is brought into contact (at the same time, the contact piece 28b and the counter electrode terminal 30 are also brought into contact).

Therefore, the modulated high frequency power P amplified by the power amplifier 16 is passed through the switch box 12 and
Electrode catheter 13 or electrode catheter 13 and counter electrode 1
4 is supplied.

In the electrocardiograph output state, the intracardiac potential (potential in the myocardium in the heart) is passed through the electrode catheter 13.
Is supplied to the electrocardiograph, and the intracardiac potential at the contact position of the electrode catheter 13 measured by the electrocardiograph is imaged as an electrocardiogram.

In the output state of the electrode catheter, the modulated high frequency power P is supplied into the heart through the electrode catheter 13 and cautery C or test T is performed. Further, in the bipolar state, electricity is applied between the distal terminal 29a and the proxy terminal 29c, and in the monopolar state, electricity is applied between the distal terminal 29b and the counter electrode terminal 30.

As shown in FIG. 3, the electrode catheter 13 is formed into a tubular body that can be inserted into a blood vessel or the like, and has electrodes of a distal electrode, a distal 13a, and a front electrode, a proximal 13b. It has a general-purpose two-lumen structure divided into two parts. At the rear end, a distal plug 13c and a proxy plug 1 for energizing
Two plugs 3d are provided, the distal plug 13c is connected to the distal 13a, and the proximal plug 13d is connected to the proximal 13b by electric wires L, respectively.

As a method of energizing the electrode catheter 13, a bipolar type in which electricity is applied between the distal 13a and the proximal 13b, or a distal 13a and a counter electrode plate 1 are used.
There is a monopolar type that energizes between four.

The arithmetic unit 19 has detectors 31a and 31b, an arithmetic circuit 32 and a display circuit 33, and outputs an output signal based on the detection signal input from the voltage stabilizing unit 18 to the display unit 20 and the impedance control unit 21. Output to. The detection signal is a part of the modulated high frequency power P output to the switch box 12.

The detector 31a detects a voltage component from the input detection signal and outputs it to the arithmetic circuit 32. Similarly,
The detector 31b outputs the detected current component to the arithmetic circuit 32.

The arithmetic circuit 32 has a CPU 32a, and the voltage of the modulated high frequency power P which is the output power to the switch box 12 from the detected voltage component and current component,
Each value of current, impedance, power and energy is calculated. The calculation result is sent to the display circuit 33 as a display signal.

At the same time, the comparison signal corresponding to the calculated impedance value is sent from the calculation circuit 32 to the impedance control section 21.

The display circuit 33 converts the input display signal into a DC signal for display and control, and displays it on the display section 20 formed on the outer surface of the modulated high frequency power generator 11.

Therefore, the calculator 19 measures the energizing current in the myocardium when the weak current generated by the modulated high frequency power P is applied to the myocardium.

As shown in FIG. 4, the display section 20 includes an energy (JOULE) display section 34 and an electric power (W) display section 3.
5, voltage (V) display unit 3 including current (A) display unit 36, analog voltmeter 37a, and voltage setting volume 37b
7, an impedance (Ω) display section 38 having an impedance setting digital switch 38a, and a timer (SEC) display section 39.

Note that the display unit is shown in parentheses, and each value is digitally displayed except for the voltage (V).

In the figure, 40 is a power switch and 41
Is a test switch, 42 is a start switch, 43 is a stop switch, 44 is a manual switch, 45 is a clear switch, 46 is an output connector, 47 is an impedance control switch, and 48 is an output indicator lamp. Manual switch 44 is ON while it is being pressed
It becomes a state.

The impedance control section 21 has a comparator 49 for measuring and comparing input signals, and outputs a control signal from the comparator 49 to the voltage stabilizing section 18.

The reference voltage V0 is applied to the comparator 49, and the comparison voltage of the comparison signal input to the impedance controller 21 is compared with the reference voltage V0. As a result of the comparison, when the comparison voltage is equal to or higher than the reference voltage V0, the comparator 49 outputs a high level signal (control signal). By inputting this high level signal to the voltage stabilizing unit 18, the output of the modulated high frequency power P from the voltage stabilizing unit 18 to the switch box 12 is stopped.

Therefore, the impedance control section 21 functions as a supply control means.

Next, the operation of the medical high-frequency ablation device having the above configuration will be described.

First, the power switch 40 is turned on, the impedance control switch 47 is turned on, and the impedance setting digital switch 38a is set.
Set the impedance rise value with.

Changeover switch 24 of switch box 12
After selecting either monopolar or bipolar, the selector switch 23 selects the electrocardiograph output.

The electrode catheter 13 is inserted into the heart through the blood vessel of the patient H, and the abnormal electrical stimulation source or conduction path that is the ablation site is mapped. At this time, the intracardiac potential is supplied to the electrocardiograph through the electrode catheter 13,
The target position can be specified by measuring the intracardiac potential with an electrocardiograph.

After the mapping is completed and the target position can be specified, a high frequency output is selected by the changeover switch 23, the test switch 41 is turned on, and a weak current is supplied to the myocardium by the modulated high frequency power P. By supplying a weak current to the myocardium, the resistance value in the myocardium is displayed on the impedance display section 38, and it can be confirmed whether or not the distal 13a of the electrode catheter 13 is surely in contact with the ablation site.

Generally, when the distal 13a is in contact with the endocardial surface, a resistance value of 80Ω to 150Ω is measured.

Therefore, the calculation unit 19 determines that the modulated high frequency power P
It functions as an energization measuring means for measuring the energizing current in the myocardium when the weak current is energized.

Subsequently, the output voltage value is set by operating the voltage setting volume 37b according to the planned cauterization power and the impedance value.

After setting the output voltage value, the manual switch 44 is turned on to supply the modulated high frequency power P to the electrode catheter 13 to cauterize the myocardium.

At this time, the modulated high frequency power P uses the rising of the modulated high frequency as a soft start (see FIG. 2), and
Low frequency filter 16b and DC component removal filter 1
Since it is supplied via 6c, it is possible to prevent microshock and improve the safety to the patient during supply.

During the energization of the modulated high frequency power P, if the intracellular tissue is denatured and the resistance value rises and the impedance rise value exceeds the set value, the supply is stopped.

That is, after the manual switch 44 is turned on, the impedance of the living tissue is equal to or more than the value (reference voltage V0) obtained by adding the set impedance increase value with reference to the impedance value at the time point of about 3 seconds. Rises, the modulated high frequency power generator 11 operates and the control signal from the impedance controller 21 is output to the voltage stabilizer 18.

Due to the output of the control signal, the impedance display of the impedance display section 38 flickers and the supply of the modulated high frequency power P is stopped, so that the excessive increase of the living tissue is prevented.

The impedance increase value in the impedance control section 21 is set to a value that can stop the power supply and prevent the destruction of myocardial cells when it suddenly increases, and is generally set to about 50Ω to 100Ω.

Although the above operation is described for the manual operation, the timer operation is also possible.

At this time, after setting the cauterization time on the timer display section 39, the cauterization can be started by the start switch 42. When it is desired to stop the cauterization on the way, the ablation can be stopped by the stop switch 43. Others are the same as during manual operation.

By the way, it is experimentally found that the impedance is used as the detection signal of the impedance control section 21 which is the energization control means, and the current has the largest speed and amount of electrical change during cauterization. This is because it is most suitable to safely perform cauterization by monitoring the current and converting it into an impedance value in the arithmetic circuit 31 to use.

As described above, when cauterizing the ablation area by the modulated high frequency current, the modulated high frequency power is used to cauterize a narrower area of the myocardium deeply without microshock, and to ablate the site to be cauterized. When the impedance value of the myocardium is constantly monitored and an increase value is set, and when the value exceeds the value obtained by adding the set value based on the initial impedance value, the supply of modulated high-frequency power is stopped and the cells due to overcauterization of the myocardium are stopped. By preventing the destruction, it is possible to enhance the safety during myocardial ablation.

In particular, since the actual impedance value of the myocardium can be measured before cauterization and it can be confirmed that the tip part of the electrode catheter 13 is surely contacting the endocardial surface, more accurate cauterization is achieved. It will be possible.

That is, by measuring the intracardiac potential with the electrode catheter 13 in direct contact with the stimulation conduction system,
It is possible to confirm that the electrode catheter 13 is surely positioned at the site corresponding to the ablation before the ablation of the ablation region myocardium. Further, by using the impedance value as the detection signal, a more accurate ablation power value is set. be able to.

Furthermore, since the voltage stabilizing circuit 18a for stabilizing the output voltage of the voltage setting type is built in, a stable and constant voltage can be always supplied, so that stable cauterization is possible.

The electrode catheter 13 is not limited to a specific one, and a general-purpose electrode catheter can be used as long as it is a high-frequency electrode catheter.

[0066]

EFFECTS OF THE INVENTION The medical radiofrequency ablation device according to the present invention has the above-mentioned configuration. Therefore, by measuring the intracardiac potential in a state where the electrode catheter is in direct contact with the stimulation conduction system, Before cauterization, it can be confirmed that the electrode catheter is surely positioned at the site corresponding to cauterization.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a medical high-frequency ablation device according to the present invention.

FIG. 2 is a schematic diagram of a waveform of a modulated high frequency wave.

FIG. 3 is a schematic configuration diagram of an electrode catheter.

FIG. 4 is a plan view of a display unit of the modulated high frequency power generator.

[Explanation of symbols]

 10 Medical High Frequency Cautery Device 11 Modulated High Frequency Power Generation Device 13 Electrode Catheter 19 Computing Unit (Electrical Measurement Unit) P Modulated High Frequency Power

Claims (1)

[Claims] 1. A high frequency current is applied to the ablated part myocardium of the heart via an electrode catheter to which a high frequency power is supplied, and the ablated part myocardium is cauterized by Joule heat generated by the applied high frequency current. In a medical high-frequency ablation device, the high-frequency power is provided with a modulated high-frequency power generation device that generates a plurality of modulated high-frequency powers including weakly modulated high-frequency power as modulated high-frequency power, and is weak before ablation of the ablation region myocardium. A modulated high frequency current is applied to the myocardium,
A medical radiofrequency ablation device having an energization measuring means for measuring an energizing current in the myocardium when energized.