CN114948174A - Intelligent pulsed electric field ablation system for controlling output channel - Google Patents

Abstract

The invention belongs to the technical field of pulsed electric field ablation, and particularly relates to an intelligent pulsed electric field ablation system for controlling an output channel. The system comprises a pulse electric field ablation instrument and a multi-electrode pulse ablation catheter, wherein the multi-electrode pulse ablation catheter opens or closes a channel for outputting a high-voltage pulse signal according to a detection result of the pulse electric field ablation instrument; the multi-electrode pulse ablation catheter is also used for detecting the acquisition of impedance signals, PH value acquisition signals and/or dielectric constant signals at the catheter; the pulse electric field ablation instrument judges the ablation state of a high-voltage pulse signal acting on human tissues through one or more detection results of impedance detection, pH value detection and dielectric constant detection, and the ablation state is used for visual marking. The system reflects the state of human tissue at each electrode in the current high-voltage pulse ablation according to the change conditions of the impedance change rate, the PH value and the dielectric constant of the electrode, and carries out marking and intelligent switching according to the state.

Description

An intelligent pulsed electric field ablation system with output channel control

technical field

The invention belongs to the technical field of pulse electric field ablation, in particular to an intelligent pulse electric field ablation system for controlling an output channel.

Background technique

Existing treatments for tachyarrhythmias often use thermal ablation techniques such as radiofrequency and cryoablation. Among them, radio frequency technology can generate a sine wave with a fixed frequency. The generated radio frequency energy acts on the lesion to be treated through the radio frequency catheter or the radio frequency electrode, so as to achieve the effect of blocking or conditioning, thereby achieving the effect of treatment. In contrast, cryoablation absorbs heat through the evaporation process of the liquid refrigerant in the cryo-balloon, so that the temperature around the ablation target is suddenly lowered. Through low temperature, the tissue cells in the lesion area are damaged or killed, so as to achieve the purpose of treatment. The clinical application of these ablation techniques is limited by the thermal pool effect, and it is difficult to achieve full-thickness transmural ablation goals. At the same time, these ablation techniques do not have cell selectivity, so non-target cells will also be ablated and destroyed. .

In view of the above-mentioned defects of thermal ablation technology, pulsed electric field ablation technology as a non-thermal ablation technology has received increasing attention in clinical application. The pulsed electric field ablation technology is to generate a high-voltage pulsed electric field with a pulse width of milliseconds, microseconds or even nanoseconds, and release extremely high energy in a short period of time, which can make cell membranes and even intracellular organelles such as endoplasmic reticulum, endoplasmic reticulum, etc. Mitochondria, nuclei, etc. will produce a large number of irreversible micropores. And then cause the apoptosis of the diseased cells, so as to achieve the expected therapeutic purpose.

In the application of the treatment of tachyarrhythmia, the use of pulsed electric field ablation technology can selectively treat cardiomyocytes without affecting other non-target cells and tissues. specialty. Therefore, pulsed electric field ablation technology is expected to become an ideal means of cardiac ablation.

In the prior art, the ablation device usually needs to be used in combination with an electrophysiological three-dimensional mapping system. The ablation device outputs energy to the lesion to cause the transformation of the lesion, and the electrophysiological three-dimensional mapping system monitors the ablation process by collecting signals, for example, The electrophysiological 3D mapping system can mark the ablation points, so that the ablation position can be displayed intuitively, and the operator can adjust the parameters of the ablation equipment and the ablation direction in time according to the returned data displayed by the electrophysiological 3D mapping system.

After pulsed electric field discharge ablation is used, usually pulsed electric field discharge discharges between multiple electrodes to complete pulse energy output, rather than single-point ablation. Therefore, based on single-point ablation, the pressure sensor is used to feedback the ablation effect. The method of marking the ablation points of the measurement system is no longer suitable for the pulsed electric field discharged between multiple electrodes. It is necessary to improve the high-voltage pulse ablation and provide a new system for feedback of the ablation effect.

SUMMARY OF THE INVENTION

In view of the problem that the existing ablation point labeling method of the electrophysiological three-dimensional mapping system cannot accurately reflect the effect of multi-point ablation of high-voltage pulse signals, the present invention selects new parameters, such as impedance value, pH value and dielectric constant, according to these The change of parameters reflects the state and effect of high-voltage pulse ablation. Therefore, a pulsed electric field ablation system with intelligent control of the output channel is proposed.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

An intelligent pulsed electric field ablation system with output channel control, comprising a pulsed electric field ablation instrument and a multi-electrode pulsed ablation catheter,

The multi-electrode pulse ablation catheter opens or closes a channel for outputting high-voltage pulse signals according to the detection result of the pulse electric field ablation instrument; the multi-electrode pulse ablation catheter is also used for impedance signals at the catheter, pH value acquisition signals and/or Or the acquisition of dielectric constant signal;

The pulsed electric field ablation instrument performs impedance detection according to the impedance signal, performs pH value detection according to the pH value acquisition signal, and performs dielectric constant detection according to the dielectric constant signal. One or more of the detection results in the detection determine the ablation state after the high-voltage pulse signal acts on the human tissue, and the ablation state is used for visual marking.

As a preferred solution of the present invention, the ablation state includes non-perforation and perforation. When the ablation state is perforated, the channel for outputting high-voltage pulses is closed, and when the ablation state is non-perforated, the channel for outputting high-voltage pulses remains open.

As a preferred solution of the present invention, the impedance detection includes the detection of the impedance value and the detection of the impedance change rate,

If the impedance value is within the first impedance threshold value range and the impedance change rate is within the first change rate range, the electrode outputting the high-voltage pulse is in the blood pool and is not in contact with human tissue;

When the impedance value is within the second impedance threshold value range and the impedance change rate is within the second change rate range, the electrode outputting the high-voltage pulse is in contact with the human tissue.

As a preferred solution of the present invention, the method for acquiring the impedance signal used for impedance detection is as follows: load a signal with a frequency of 2KHz to 200KHz on the electrode of the multi-electrode pulse ablation catheter, collect the signal from 2KHz to 200KHz and act on the electrode after the electrode is collected. The return signal is converted into an impedance signal through filtering processing.

As a preferred solution of the present invention, on the premise that the electrode outputting the high-voltage pulse is in contact with human tissue, if the result of the pH value detection is that the variation range is within the range of ±0.5, the ablation state is perforation.

As a preferred solution of the present invention, on the premise that the electrode outputting the high-voltage pulse is in contact with human tissue, if the dielectric constant detection result is within the preset dielectric constant range, the ablation state is perforation.

As a preferred solution of the present invention, the method for obtaining the dielectric constant signal for dielectric constant detection is:

The sinusoidal excitation signal is applied to human tissue through the electrodes of the multi-electrode pulse ablation catheter. The frequency range of the sinusoidal excitation signal is 5KHz-300MHz, and the complex impedance electrical signal returned after the sinusoidal excitation signal of different frequencies acts on the human tissue is obtained. , the complex impedance electrical signal is a dielectric constant signal.

As a preferred solution of the present invention, on the premise that the electrode outputting the high-voltage pulse is not in contact with the human tissue, the result of the pH value detection is that the variation range is within the range of ±0.5, and the result of the dielectric constant detection is within the preset dielectric constant. The electric constant range, the ablation state is perforation.

As a preferred solution of the present invention, if the impedance change rate, the pH value change rate, and the dielectric constant change rate tend to be stable, the ablation state is perforation.

As a preferred solution of the present invention, it also includes a cardiac electrophysiological three-dimensional mapping system,

The cardiac electrophysiology three-dimensional mapping system is connected in communication with the pulsed electric field ablation instrument, and is used for displaying ablation status marks in the three-dimensional heart image;

The cardiac electrophysiology three-dimensional mapping system is also used to detect key conduction signals, the key conduction signals come from the sinoatrial node, atrioventricular node or His bundle, and output the key conduction signals to the pulsed electric field ablation instrument; the pulsed electric field ablation instrument shuts off the channel of the high-voltage pulse signal related to the key conduction signal.

Compared with the prior art, the beneficial effects of the present invention:

According to the electrode impedance, pH value and dielectric constant, the system of the invention reflects the state of human tissue at each electrode in the current high-voltage pulse ablation, and accurately reflects the multi-point ablation effect of the high-voltage pulse signal.

Description of drawings

1 is a system connection block diagram of a pulsed electric field ablation system for intelligently controlling an output channel in Embodiment 1 of the present invention;

2 is a schematic block diagram of a pulsed electric field ablation system for intelligently controlling an output channel in Embodiment 1 of the present invention;

3 is a schematic diagram of classification of impedance detection schemes in Embodiment 1 of the present invention;

4 is a schematic diagram of time-sharing handover detection in Embodiment 1 of the present invention;

5 is a schematic diagram of frequency division switching detection in Embodiment 1 of the present invention;

6 is a schematic diagram of fusion extraction detection in Embodiment 1 of the present invention;

7 is a schematic diagram of a pH detection scheme in Example 1 of the present invention;

8 is a schematic diagram of a dielectric detection scheme in Embodiment 1 of the present invention;

9 is a structural diagram of a spherical multi-electrode pulsed electric field ablation catheter with variable shape in Example 1 of the present invention;

FIG. 10 is an expansion diagram of a spherical multi-electrode pulsed electric field ablation catheter with variable shape in Example 1 of the present invention;

11 is a schematic diagram of the expansion and alignment of the spherical multi-electrode pulsed electric field ablation catheter with variable shape in Example 1 of the present invention;

12 is a schematic diagram of a ring-shaped multi-electrode pulsed electric field ablation catheter in Embodiment 1 of the present invention;

13 is a schematic diagram of the stretching of the annular multi-electrode pulsed electric field ablation catheter in Embodiment 1 of the present invention;

14 is a schematic diagram of a variable-shape annular multi-electrode pulsed electric field ablation catheter in Example 1 of the present invention;

15 is a schematic diagram of the distal end of a variable-shape annular multi-electrode pulsed electric field ablation catheter (with a guide wire) in Example 1 of the present invention;

FIG. 16 is an example of ablation point marking of the cardiac electrophysiology three-dimensional mapping system in Embodiment 1 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be construed that the scope of the above-mentioned subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

Example 1

The block diagram and realization principle of a pulsed electric field ablation system that intelligently controls the output channel are shown in Figure 1-2. A multi-electrode pulsed electric field ablation catheter that can be used with this system is shown in Figures 9-15. The following is the detailed implementation process.

1. There is a certain difference between the impedance of the multi-electrode pulsed electric field ablation catheter in the blood pool and the impedance of the adjacent tissue. At the same time, during the movement of the catheter, the change of the degree of contact can have a certain response to the rate of change of the impedance. . Therefore, it can be judged whether it is currently in contact with the tissue through the impedance between the electrodes, and at the same time, the degree of tissue abutment can be reflected by the rate of change of the impedance.

2. When the tissue is discharged by the pulsed electric field, it will cause the programmed cell death due to irreversible electroporation. These will reflect a drop in impedance at the ablation site, a change in pH, a change in dielectric constant, etc. However, when the pulsed electric field is ablated to a certain extent, these changes will be slower and reach a certain balance, because the cardiomyocytes that can cause irreversible electroporation under this electric field intensity have already been processed, and there is not much to continue ablation. meaning. Therefore, after each ablation, the impedance value change, pH value change, dielectric constant change, etc. of the current ablation position can be detected in real time, to determine whether the current point needs to be pulsed electric field ablation.

3. In order to avoid the impact of pulsed electric field ablation on conductive cells of important tissues (such as sinoatrial node, His bundle, etc.), it is necessary to effectively identify the electrophysiological signals around the electrodes, and identify the risky electrodes in the surrounding electrophysiological signals. Avoid discharging.

4. The impedance detection can be performed in the following ways: time-division switching detection, fusion extraction detection, and frequency-division switching detection. The detection signal here usually has a loading frequency of 2Khz to 200Khz, and the electrical signal obtained by the extraction is converted into an actual impedance signal through filtering, as shown in Figure 3-Figure 6. When the impedance value is 150 ohms, it is considered that the electrode is close to the tissue. After high-voltage pulse ablation is performed ten times, the impedance value decreases by 40-50 ohms, indicating that it is an effective ablation point. When the electrode is in the blood pool, the impedance is 100 ohms, but when the electrode is attached to human tissue, the impedance value is 200 ohms. Not only the impedance value is used to reflect the attachment state, but also the impedance change rate is used to reflect the attachment state. In the blood pool, the impedance change rate is lower. When it is close to the human tissue, the impedance change rate is higher. The impedance change rate not only reflects the degree of contact between the electrode and the human body, but also reflects the relative position relationship between the electrode and the tissue. .

5. PH detection usually uses a PH sensor, and the PH value of the corresponding area of different electrodes is detected by time-sharing through channel switching. For example, if the PH value is stable within the range of ±0.5, it means that the perforation is completed and no further ablation is required. In addition, It is detected that the concentration of NA ions is high and the pH value is high. When the cells are perforated, the potassium ions in the cells overflow and the pH value drops, indicating that the system has perforated through the wall and the ablation is completed, which is an effective ablation point.

6. The detection of dielectric constant uses sinusoidal excitation signals with multiple frequencies in the range of 5KHz-300MHz to stimulate and respond to changes in complex impedance electrical signals corresponding to cells and tissues under different frequency signals. These signals are converted into signals in the frequency domain by methods such as Fourier transform. The frequency domain signals of different types of cells and even ions at a certain frequency can be obtained. The frequency domain signal is a characteristic value that can reflect its changes, and this value is used as the basis for judging the dielectric constant. Changes in the dielectric constant of cardiomyocytes, NA ions, CA ions, and K ions, can reflect the changes in the area of cells after pulsed electric field ablation to a certain extent.

Further, the impedance detection includes the detection of the impedance value and the detection of the impedance change rate,

When the impedance value is within the first impedance threshold value range and the impedance change rate is within the first change rate range, the electrode outputting the high-voltage pulse is in the blood pool and is not in contact with the human tissue. The first impedance threshold range is 100-150 ohms; the first change rate range of the impedance change rate is that the impedance change rate is much larger than 50 ohms/0.5 seconds.

When the impedance value is within the second impedance threshold value range and the impedance change rate is within the second change rate range, the electrode outputting the high-voltage pulse is in contact with the human tissue. The second impedance threshold range of the impedance value is about 200 ohms, and the second change rate range of the impedance change rate is about 50 ohms/0.5 seconds.

Further, under the premise that the electrode outputting the high-voltage pulse is in contact with the human tissue, if the result of the pH value detection is within the range of ±0.5, then only the result of the pH value detection can be used to judge. The ablation state is perforation.

Further, on the premise that the electrode outputting the high voltage pulse is in contact with the human tissue, if the dielectric constant detection result is within the preset dielectric constant range (for example, the K ion dielectric constant is 100), the ablation state is perforation.

In addition, under the premise that the electrodes that output high-voltage pulses are not in contact with human tissue, it is necessary to meet the requirements that the pH value detection result is within the range of ±0.5, and the dielectric constant detection result is within the preset dielectric constant. range, the ablation state can be judged as perforation.

7. The electrophysiological signal mainly collects the electrophysiological signal indicated on the electrode circuit through a band-pass filter acquisition circuit, and judges and identifies it through an algorithm.

7.1. The specific intelligent output channel control is based on the one shown in Figure 1-3. The pulsed electric field ablation instrument has the functions of impedance detection, PH detection and dielectric constant detection, and the identification of electrophysiological signals is realized by establishing the consumable catheter and the cardiac electrophysiological three-dimensional mapping system through the pulsed electric field ablation instrument.

7.2 The pulse electric field ablation instrument judges the current impedance situation through impedance detection, and identifies whether the current electrode position is a blood pool based on this. If it is there the electrode will not discharge. It is guaranteed that there will be no meaningless discharge in the case of sticking to the blood pool.

7.3 The pulse electric field ablation instrument can identify the change rate of the current electrode impedance through impedance detection. When the change rate has a large change or a large back-and-forth fluctuation, it can be used to judge that the current electrode is unstable or even the degree of adhesion is decreased. At this time, the electrodes here should not be discharged, so as not to reduce the effect of the discharge. It will not be activated until the pulsed electric field ablation instrument judges that the position is well attached through impedance detection by operating the catheter.

7.4 The pulse electric field ablation instrument will also judge the impedance characteristics of the current electrode ablation after each discharge by means of impedance detection, PH detection, dielectric constant detection, etc. When the above parameters are combined, when the impedance value, pH value, and the rate of change and fluctuation of the dielectric constant tend to be stable, it is considered that the region where the current electrode is located no longer needs to be ablated. The pulsed electric field ablation instrument will disconnect the electrode path according to the result, and will not perform ablation until the catheter moves to other areas, and the pulsed electric field energy ablation instrument will make the energy output function of the electrode path.

7.5 The multi-electrode ablation catheter and the cardiac electrophysiological three-dimensional mapping system are established through the path established by the pulsed electric field ablation instrument, and the electrophysiological signal monitoring of the multi-electrode catheter can be carried out. When the cardiac electrophysiology 3D mapping system recognizes that the electrophysiological signals on some electrode pathways are key conduction signals, such as the sinoatrial node, the atrioventricular node or the bundle of His. The cardiac electrophysiology 3D mapping system is sent to the pulsed electric field ablation instrument in time through the communication bus, and the pulsed electric field ablation instrument disconnects the electrode path that needs protection determined according to the cardiac electrophysiology 3D mapping system to ensure that the energy output will not pass through this electrode path , effectively ensuring the safety of ablation.

7.6 During the ablation process, the pulsed electric field ablation instrument switches the electrode path intelligently according to the above information, so as to ensure that the electrode path is effectively attached to the position where the treatment needs to be continued for ablation. During this process, the pulsed electric field ablation instrument will transmit the information of the enabled electrode pathway to the cardiac electrophysiology three-dimensional mapping system in real time. The cardiac electrophysiology 3D mapping system can mark the actual discharge points on the ablation model according to this information. The discharge point marked by this method can indicate the effective ablation point, so that the operator can judge whether the ablation area meets the requirements according to the discharge point, so that the patient can obtain more effective treatment.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. It is obvious to those skilled in the art that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and scope of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described according to an embodiment, it does not mean that the embodiment only includes an independent technical solution. This description in the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole and implement the The technical solutions in the examples can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims (10)

1. An intelligent pulsed electric field ablation system for controlling an output channel is characterized by comprising a pulsed electric field ablation instrument and a multi-electrode pulsed ablation catheter,

the multi-electrode pulse ablation catheter opens or closes a channel for outputting a high-voltage pulse signal according to the detection result of the pulse electric field ablation instrument; the multi-electrode pulse ablation catheter is also used for acquiring impedance signals, PH value acquisition signals and/or dielectric constant signals at the catheter;

the pulsed electric field ablation instrument carries out impedance detection according to the impedance signal, carries out PH value detection according to the PH value acquisition signal, carries out dielectric constant detection according to the dielectric constant signal, and judges the ablation state of the high-voltage pulse signal after being applied to human tissues through one or more detection results of the impedance detection, the PH value detection and the dielectric constant detection, wherein the ablation state is used for visual marking.

2. The system of claim 1, wherein the ablation state comprises unperforated and perforated, and wherein the channel outputting the high voltage pulse is closed when the ablation state is perforated and remains open when the ablation state is unperforated.

3. An intelligent output channel-controlled pulsed electric field ablation system as in claim 1, wherein said impedance detection includes detection of an impedance value and detection of a rate of change of impedance,

when the impedance value is in a first impedance threshold range and the impedance change rate is in a first change rate range, the electrode outputting the high-voltage pulse is in the blood pool and is not attached to human tissues;

and when the impedance value is in a second impedance threshold range and the impedance change rate is in a second change rate range, the electrode outputting the high-voltage pulse is attached to the human tissue.

4. The system of claim 3, wherein the impedance signal for the impedance detection is obtained by: and loading signals with the frequency of 2KHz to 200KHz to the electrode of the multi-electrode pulse ablation catheter, collecting return signals of the signals from 2KHz to 200KHz acting on the electrode, and converting the return signals into impedance signals through filtering treatment.

5. The system as claimed in claim 3, wherein the ablation state is perforation if the variation of the PH value detected by the PH value detection is ± 0.5, under the condition that the electrode outputting the high voltage pulse is attached to the human tissue.

6. The system as claimed in claim 3, wherein the ablation state is perforation if the result of the permittivity detection is within a predetermined permittivity range under the condition that the electrode outputting the high voltage pulse is attached to the human tissue.

7. The system of claim 6, wherein the permittivity signal for permittivity detection is obtained by:

and (3) enabling the sinusoidal excitation signal to act on human tissues through the electrodes of the multi-electrode pulse ablation catheter, wherein the frequency range of the sinusoidal excitation signal is 5KHz-300MHz, and acquiring a complex impedance electric signal returned after the sinusoidal excitation signal with different frequencies acts on the human tissues, wherein the complex impedance electric signal is a dielectric constant signal.

8. The system as claimed in claim 3, wherein the ablation status is perforation if the PH value detected by the PH sensor is within ± 0.5 and the permittivity detected by the permittivity sensor is within the predetermined permittivity range, without the electrode outputting the high voltage pulse contacting the tissue.

9. The system of claim 1, wherein the ablation state is perforation if the rate of change of impedance, the rate of change of PH, and the rate of change of permittivity are stable.

10. The system of any one of claims 1-9, further comprising a cardiac electrophysiology three-dimensional mapping system,

the cardiac electrophysiology three-dimensional mapping system is in communication connection with the pulsed electric field ablation instrument and is used for displaying an ablation state mark in a cardiac three-dimensional image;

the cardiac electrophysiology three-dimensional mapping system is also used for detecting key conducting signals from a sinoatrial node, an atrioventricular node or a his bundle and outputting the key conducting signals to the pulsed electric field ablator; and the pulsed electric field ablator cuts off the channel of the high-voltage pulse signal related to the key conduction signal.

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