CN116269731A

CN116269731A - Pulsed electric field ablation system

Info

Publication number: CN116269731A
Application number: CN202310148875.5A
Authority: CN
Inventors: 谭家宏; 杨永刚; 关鼎
Original assignee: Shanghai Xinlutong Life Technology Co ltd
Current assignee: Shanghai Xinlutong Life Technology Co ltd
Priority date: 2023-02-22
Filing date: 2023-02-22
Publication date: 2023-06-23

Abstract

The invention provides a pulsed electric field ablation system, which comprises an ablation catheter and ablation equipment, wherein the ablation catheter is connected with the ablation equipment; the ablation catheter comprises an operation handle, a catheter main body and a treatment head, wherein the operation handle of the ablation catheter is positioned at the proximal end of the catheter main body, and the treatment head of the ablation catheter is positioned at the distal end of the catheter main body; the proximal end of the operating handle is connected with the ablation equipment through a tail wire; the ablation device comprises a control system, wherein the control system can control and switch each group of electrodes to perform impedance measurement or ablation, the impedance between the electrodes is obtained through calculation by using alternating current signals to measure voltage and current values, whether the electrodes are well attached to myocardial tissues or not is judged and confirmed through the impedance values, and the good attachment improves the effectiveness of ablation energy reaching a target point; different pairing combinations of electrodes are realized through a switching circuit, then the optimal electrode combination discharge is selected according to judgment, and an electric field with transverse, vertical oblique and interval discharge is formed, namely, an optimal surgical ablation scheme is obtained aiming at different pulmonary vein morphologies.

Description

Pulsed electric field ablation system

Technical Field

The invention relates to the field of medical appliances, in particular to a pulsed electric field ablation system.

Background

Ablation is first used in the treatment of supraventricular tachycardia patients with the auxiliary pathways and pre-excitation syndromes, and today, ablation is also used in the treatment of atrial flutter, fibrillation and ventricular arrhythmias.

The cornerstone of atrial fibrillation treatment is the isolation of the pulmonary veins in the left atrium, and pulsed electric fields are of great interest for their excellent effectiveness and safety. In the field of atrial fibrillation treatment, bidirectional conduction block is realized mainly through pulmonary vein isolation, so that the aim of incapacity of conducting abnormal electric signals is fulfilled. The pulse electric field ablation core is to destroy abnormal myocardial cells (irreversible electroporation) by an electric field, thereby preventing abnormal electrocardiosignal transmission and achieving the aim of treating tachycardia diseases such as atrial fibrillation. When the catheter releases an electric field through the electrodes inside the heart, more electric field energy is introduced into the blood rather than targeted to myocardial tissue due to inconsistent impedance between the blood and myocardial tissue, particularly in conditions of poor tissue apposition. In the prior art, when an ablation area is discharged, the electrode only presents one electric field distribution state in a vertical discharge mode, so that a discontinuous ablation area is generated in the ablation area after discharge, the discharge distribution is incomplete, and the ablation effect of the ablation area is not optimal.

Patent CN114404035a discloses an ablation device with mapping function, comprising: an outer tube; an ablation assembly disposed at a distal end of the outer tube, comprising a radially contractible and expandable support skeleton and a plurality of electrodes disposed on the support skeleton; wherein at least one first electrode capable of being used for mapping is arranged in a plurality of the electrodes; the connector is arranged at the proximal end of the outer tube and comprises a plurality of conductive terminals, the connector is electrically connected with a plurality of electrodes through a plurality of conductive terminals, at least one first terminal is arranged in the conductive terminals, each first terminal is electrically connected with a corresponding first electrode in a one-to-one mode, and when the connector is connected to external mapping equipment, the first electrodes can be used for mapping through the first terminals. The patent enables the ablation device to have the functions of mapping and ablation, solves the problems that two devices of an ablation catheter and a mapping catheter are required to be guided respectively in an operation, and simplifies operation, but the ablation device in the patent cannot realize connection and uniform discharge of electrodes in an ablation area, and has poor ablation effect on the ablation area.

Patent WO2022171149A1 discloses an ablation device comprising an outer tube, a supporting framework and an ablation member, wherein the supporting framework is arranged at the distal end of the outer tube and is in a radially contractible and expandable bracket structure, the supporting framework comprises a bearing frame and a connecting member, and the connecting member is used for connecting every two adjacent bearing rods so as to keep the distance between the adjacent bearing rods; the ablation piece is arranged on the supporting framework and used for outputting ablation energy to ablate the target ablation area. This patent passes through connecting piece and connects adjacent carrier bar to when the carrier frame receives external force to take place deformation, pull adjacent carrier bar, keep the interval between the adjacent carrier bar, keep the stability of carrier bar position, make the whole difficult distortion of carrier frame, avoid the interval to lead to the contact to take place the short circuit between the ablation piece too little between the carrier bar, avoid the damage of breaking down to target tissue, and then improve the ablation security, but this ablation device does not have the mapping function.

Patent WO2022007490A1 discloses a system for treating arrhythmias with pulsed electric field ablation techniques, comprising a voltage pulse system console, a pacing and ECG unit and an ablation catheter; the voltage pulse system console comprises an electric pulse generator, a controller, a human-computer interface and a converter; the pacing and ECG unit comprises a cardiac stimulator, an ECG recorder, a pacing catheter, a mapping catheter and a connector, and pacing electrical signals are synchronously transmitted to a voltage pulse system console; the ablation catheter comprises a distal end, a main body middle section and a proximal end control handle which are sequentially connected; the ablation catheter is connected to the system console through a transducer, and the pulse electric field is transmitted to the ablation tissue through an electrode on the ablation catheter; during an ablative discharge, the transducer isolates the pacing and ECG units from the pulse system console. According to the patent, the electrodes in the spline basket and the annular catheter are controlled to conduct discharge ablation, so that local, linear, annular or uniformly distributed large-area irreversible damage can be formed, the ablation area breaks through the traditional annular ablation of the pulmonary vein orifice, and the ablation efficiency is improved. But the patent is primarily for ablation.

Therefore, how to improve the discharge mode of the electrode in the ablation area, so that the electrode can generate a complete and continuous electric field in the ablation area, release more electric field energy to myocardial tissues, and improve the ablation efficiency is a technical problem to be solved.

Disclosure of Invention

In order to achieve the above object, the present application provides a pulsed electric field ablation system for delivering more electric field energy to myocardial tissue to improve ablation efficiency, comprising an ablation catheter and an ablation device, the ablation catheter being connected to the ablation device;

the ablation catheter comprises an operation handle, a catheter main body and a treatment head, wherein the operation handle of the ablation catheter is positioned at the proximal end of the catheter main body, and the treatment head of the ablation catheter is positioned at the distal end of the catheter main body; the method comprises the steps of carrying out a first treatment on the surface of the The proximal end of the operating handle is connected with the ablation equipment through a tail wire;

the treatment head comprises a spline basket having a plurality of splines, wherein each spline comprises a plurality of electrodes, the electrodes comprising ablation electrodes and mapping electrodes;

the ablation device includes a control system.

Preferably, the control system comprises a switching circuit, a high-voltage pulse output circuit and an impedance measurement circuit, wherein the high-voltage pulse output circuit, the impedance measurement circuit and the switching circuit are connected with each other, and the switching circuit is connected with the ablation electrode on the spline.

Preferably, the control system controls and switches the individual electrodes on the spline to any one or more pairs and to perform impedance measurements or ablations.

Preferably, the impedance measurement adopts alternating voltage and alternating current measurement, a voltmeter is used for measuring a voltage value V and an ammeter is used for measuring a current value I, and then the impedance Z is calculated according to a formula Z=U/I; and judging the degree of the adhesion between the electrodes and the tissues by measuring the impedance between the electrodes.

Preferably, firstly, judging the electrode leaning degree according to the impedance measurement value, if the impedance value of a certain group of electrodes is smaller, judging that the group of electrodes are in poor leaning with myocardial tissue, and disconnecting the group of electrodes during discharging to form a recommended discharging electrode combination; if a short circuit occurs in a certain group of paired electrodes, the number of the paired electrodes with the short circuit is prompted to stop discharging.

Preferably, an ac signal is emitted when measuring the impedance between each set of electrodes, the frequency, amplitude and phase of which ac signal are all adjustable.

Preferably, by switching the paired combinations of electrodes, a list of impedances of the different electrode combinations is measured, and then the abutment between the current electrode and the myocardial tissue pair is determined and determined by threshold setting and software to recommend an optimal discharge electrode combination.

In a preferred embodiment, the threshold setting is achieved by: the range of impedance thresholds of a pair of electrodes in blood can be measured N times under X-rays with the electrodes completely in the blood (not against tissue), and calculated by an average algorithm. Similarly, a plurality of pairs of electrodes can also calculate the corresponding threshold range through the method. The setting of the threshold value can be completed before discharging and measuring the impedance, so that the threshold value of the blood impedance characteristic of each patient is formed instead of the threshold value which is uniformly set in advance, and misjudgment caused by the difference of the blood impedance among patients can be avoided.

Preferably, if more than 50% of the electrodes are poorly attached, prompting that the catheter position needs to be adjusted through the impedance measurement judgment; and after the position of the catheter is adjusted, impedance measurement is carried out again to form an optimal discharge electrode combination.

Preferably, the potential of the intracardiac signal before discharge is measured by the mapping electrode, and the potential of the intracardiac signal after the discharge is completed is measured, and whether the ablation of the myocardial tissue is completed is confirmed by the change of the potential amplitude of the intracardiac signal before and after the discharge.

In a preferred embodiment, according to the recommended optimal discharge electrode combination, the switching circuit is used for realizing automatic switching discharge through one-time operation, and the discharge combination sequence is not limited, so that a transverse, vertical, oblique and interval discharge electric field can be formed, and each discharge ablation area is mutually overlapped in a crossing way to form a continuous and complete discharge effect, thereby realizing complete coverage of the ablation area.

In a preferred embodiment, the order of the discharge combinations can be freely ordered in the software according to the recommended optimal discharge electrode combinations: such as in a transverse, vertical, diagonal, transverse, diagonal spacing order, or in other orders.

Preferably, each electrode corresponds to two relay switches, and the relay comprises a relay A and a relay B, namely An nth electrode corresponds to a relay An and a relay Bn; the relay A is used for switching the positive end or the negative end of the ablation electrode corresponding to the high-voltage output; the relay B is used to switch to impedance measurement or discharge ablation.

Preferably, each electrode is provided as follows: the normally open contact of the relay An is connected to the positive end of the high-voltage pulse output, and the normally closed contact of the relay An is connected to the negative end of the high-voltage pulse output; the common end COM of the relay An is connected to a normally open contact of the relay Bn, the normally closed contact of the relay Bn is connected to An impedance measurement circuit, and the COM of the relay Bn is connected to An electrode Pn; the control signals of the two relays are connected to the controlled IO signals, and the IO signals drive the switching of the relays through the driving circuit.

The beneficial technical effects of the invention are as follows:

(1) According to the pulse electric field ablation system disclosed by the invention, the control system with the circuit switching function is arranged in the ablation equipment, the control system can control and switch each group of electrodes to perform impedance measurement or ablation, the impedance between the electrodes is obtained through calculation by using alternating current signals to measure voltage and current values, whether the electrodes are well attached to myocardial tissues or not is confirmed through judgment of the impedance values, and the effectiveness of ablation energy reaching a target point can be improved through good attachment; and the pairing combination of the electrodes is switched to form the combination of different electrodes, and then the optimal electrode combination is selected for discharging according to judgment, so that the optimal surgical ablation scheme can be obtained aiming at different pulmonary vein forms.

(2) The automatic switching discharge of the switching circuit can be realized through one-time operation, so that transverse, vertical, oblique and interval discharge electric fields can be formed, the discharge ablation areas are mutually overlapped in a crossing way, and a continuous and complete discharge effect is formed, so that the complete coverage of the ablation areas is realized, the optimal ablation effect is achieved, the operation safety is improved, and the operation time is saved.

(3) Different discharge combination modes realize complete and continuous electric isolation ablation areas in space, and further ensure long-term effectiveness of pulsed electric field ablation.

The foregoing description is only a summary of the technical solutions of the present application, so that the technical means of the present application may be implemented according to the content of the specification, and so that the foregoing and other objects, features and advantages of the present application may be more clearly understood, the following detailed description of the preferred embodiments of the present application is given in conjunction with the accompanying drawings.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of the specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is also possible for a person skilled in the art to obtain other drawings according to these drawings without inventive effort, which are all within the protection scope of the present application. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale.

FIG. 1 is a schematic diagram of the overall structure of a pulsed electric field ablation system of the present disclosure;

FIG. 2 is a schematic diagram of the switching of functions of the control system circuitry within the ablation device of the invention;

FIG. 3 is a schematic diagram of the principle of electrode impedance measurement in the present invention;

FIG. 4 is a schematic diagram of electrode impedance measurement in accordance with the present invention;

FIG. 5 is a schematic diagram of a circuit frame for each electrode arrangement in the present invention;

FIG. 6 is a schematic diagram of a lateral discharge in a preferred embodiment of the present invention;

FIG. 7 is a schematic view of a vertical discharge in a preferred embodiment of the present invention;

FIG. 8 is a schematic diagram of an oblique discharge in a preferred embodiment of the invention;

FIG. 9 is a schematic view of oblique discharge in a preferred embodiment of the present invention;

FIG. 10 is a schematic diagram of a laterally spaced discharge in a preferred embodiment of the present invention;

FIG. 11 is a schematic view of a diagonally spaced discharge in a preferred embodiment of the present invention;

FIG. 12 is a schematic view of a diagonally spaced discharge in a preferred embodiment of the present invention;

FIG. 13 is a graph showing the comparison of the prior art discharge electric field distribution of the modified front electrode with the discharge electric field distribution of the modified rear electrode assembly of the present invention;

FIG. 14 is a pre-retrofit vertical discharge mode ablation anatomic map;

FIG. 15 is a map of the vertical discharge mode ablation area prior to modification, version;

FIG. 16 is a graph of signal potential in the vertical discharge mode prior to modification;

FIG. 17 is an anatomic map of modified cross-discharge, vertical discharge, and lateral discharge ablation;

FIG. 18 is a map of modified cross discharge, vertical discharge and lateral discharge ablation zone Masion staining;

FIG. 19 is a graph of intra-cardiac signal potentials after completion of modified cross discharge, vertical discharge, and lateral discharge;

wherein, 1, an ablation catheter; 11. an operation handle; 12. a catheter body; 13. a treatment head; 2. an ablation device; 23. a switching circuit; 24. a high voltage pulse output circuit; 25. an impedance measuring circuit.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to facilitate a thorough understanding of embodiments of the present application. It will therefore be apparent to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the application. In addition, descriptions of well-known functions and constructions are omitted in the embodiments for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "the present embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the "one embodiment" or "this embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: the terms "/and" herein describe another associative object relationship, indicating that there may be two relationships, e.g., a/and B, may indicate that: the character "/" herein generally indicates that the associated object is an "or" relationship.

The term "at least one" is herein merely an association relation describing an associated object, meaning that there may be three kinds of relations, e.g., at least one of a and B may represent: a exists alone, A and B exist together, and B exists alone.

It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprise," "include," or any other variation thereof, are intended to cover a non-exclusive inclusion.

Example 1

Referring to fig. 1, fig. 1 is a schematic diagram of the overall structure of a pulsed electric field ablation system according to the present disclosure. The invention introduces a pulsed electric field ablation system, which comprises an ablation catheter 1 and an ablation device 2, wherein the ablation catheter 1 is connected with the ablation device 2;

the ablation catheter 1 comprises an operation handle 11, a catheter main body 12 and a treatment head 13, wherein the operation handle 11 of the ablation catheter 1 is positioned at the proximal end of the catheter main body 12, and the treatment head 13 of the ablation catheter 1 is positioned at the distal end of the catheter main body 12; the proximal end of the operating handle 11 is connected with the ablation device 2 through a tail wire; the treatment head 13 comprises a spline basket having a plurality of splines, wherein each spline comprises a plurality of electrodes, including ablation electrodes and mapping electrodes. The ablation equipment 2 is an ablation instrument, and the ablation equipment 2 comprises a control system, wherein the control system has a circuit switching function, and realizes recommended discharge electrode combination to form high-efficiency high-voltage pulse discharge ablation of transverse, vertical, oblique and interval discharge electric fields.

Referring to fig. 2, fig. 2 is a schematic diagram showing the switching of the functions of the control system circuit in the ablation device of the invention. The control system comprises a switching circuit 23, a high-voltage pulse output circuit 24 and an impedance measurement circuit 25, wherein the high-voltage pulse output circuit 24 and the impedance measurement circuit 25 are connected with the positive end and the negative end of the switching circuit 23, and the switching circuit 23 is connected with an ablation electrode on the spline.

Further, the control system controls and switches each electrode on the spline to conduct any one or more groups of pairing and conduct impedance measurement or ablation.

Wherein the impedance measurement principle comprises the following:

the impedance measurement adopts alternating voltage and alternating current measurement, a voltage value V and a current value I are measured through a voltmeter, and then the impedance Z is calculated according to a formula Z=U/I. Referring to fig. 3, fig. 3 is a schematic diagram of the principle of electrode impedance measurement in the present invention. The impedance between the electrode P1 and the electrode P3 is Z, and the voltage source DDS generates an excitation signal and is connected with an ammeter in series and connected with the voltmeter in a bridging way. Wherein the RC circuit and the switching circuit 23 function as a current limiting function and a switching function with the high voltage pulse output circuit 24, respectively.

Further, judging the electrode leaning degree according to the impedance measurement value, if the impedance value of a certain group of electrodes is smaller, judging that the group of electrodes are in poor leaning with myocardial tissue, and disconnecting the group of electrodes during discharging to form a recommended discharging electrode combination; if a short circuit occurs in a certain group of paired electrodes, the number of the paired electrodes with the short circuit is prompted to stop discharging.

Referring to fig. 4, fig. 4 is a schematic diagram of electrode impedance measurement according to the present invention. The voltage source DDS can output a sine wave with adjustable frequency, amplitude and phase. Since the impedance of human blood and myocardial tissue is different, the degree of the electrode's abutment with the tissue can be determined by measuring the impedance between the electrodes.

Further, a sine wave is sent out by adopting a fixed frequency or sweep frequency mode of a high-frequency alternating current signal, and enters the electrode P1 and the electrode P3 through the RC circuit and the switching circuit 23 to form a current I. The voltage U is generated due to the existence of the impedance Z, and the voltage U has smaller amplitude, and meanwhile, the human body has electric signals with other frequencies, so that the electric signals need to enter an ADC for sampling after passing through a signal processing circuit. ADC sampling comprises current and voltage sampling, converts an analog signal into a digital signal, then enters a digital signal processing unit (DSP+FPGA), calculates a real part a and an imaginary part b of U through DFT, and then passes through

And calculating a mode of the voltage U, and similarly calculating a mode of the voltage I, and finally obtaining the impedance Z through Z=U/I.

Further, by switching the pairing combination of the electrodes, a list of the impedance of different electrode combinations is obtained by measurement, and then the current electrode and myocardial tissue adhesion condition can be confirmed by threshold setting and software judgment, so that an electrode combination discharge scheme recommended by the operation is formed. For example, if the impedance measured by the electrode P1 and the electrode P3 is within the set threshold, it is determined that the electrode P1 and the electrode P3 do not adhere well to the tissue, and the combination of the electrode P1 and the electrode P3 is not used for discharging.

Wherein, the threshold setting is realized by the following modes: the range of impedance thresholds of a pair of electrodes in blood can be measured N times under X-rays with the electrodes completely in the blood (not against tissue), and calculated by an average algorithm. Similarly, a plurality of pairs of electrodes can also calculate the corresponding threshold range through the method. The setting of the threshold value can be completed before discharging and measuring the impedance, so that the threshold value of the blood impedance characteristic of each patient is formed instead of the threshold value which is uniformly set in advance, and misjudgment caused by the difference of the blood impedance among patients can be avoided.

Judging through the impedance measurement, if more than 50% of electrodes are not good in contact, automatically sending a prompt that the position of the catheter needs to be adjusted; and after the position of the catheter is adjusted, impedance measurement is carried out again to form an optimal discharge electrode combination for discharging.

Further, the control system in the ablation device 2 performs system function switching: each electrode corresponds to two relay switches, and the relay comprises a relay A and a relay B, namely An nth electrode corresponds to a relay An and a relay Bn. The relay A is used for switching the positive end or the negative end of the ablation electrode corresponding to the high-voltage output, and the relay B is used for conducting impedance measurement or discharge ablation on the switching. For example, electrode No. 1 corresponds to relay switch A1 and relay switch B1; electrode No. 2 corresponds to relay switch A2 and relay switch B2. The nth electrode corresponds to relay An and relay Bn.

Referring to fig. 5, fig. 5 is a schematic diagram of a circuit frame for each electrode arrangement in the present invention. Each electrode is provided as follows: the normally open contact of the relay An is connected to the positive end of the high-voltage pulse output, the normally closed contact of the relay An is connected to the negative end of the high-voltage pulse output, the common end COM of the relay An is connected to the normally open contact of the relay Bn, the normally closed contact of the relay Bn is connected to the impedance measuring circuit 25, and the COM of the relay Bn is connected to the electrode Pn. The control signals of the two relays are connected to the controlled IO signals, and the IO signals drive the switching of the relays through the driving circuit. As shown by number 2 in table 1 below:

table 1 shows a relay switching function table

Sequence number	Relay An state	Relay Bn state	Electrode n-state
				1	Normally open or normally closed	Normally closed type	Access impedance measurement circuit
2	Normally open	Normally open	High-voltage pulse output positive terminal is connected
				3	Normally closed type	Normally open	Accessing high-voltage pulse output negative terminal

When the driving signal An is high, the relay An is switched from a normally closed contact to a normally open contact, namely COM of the relay An is conducted with the positive end of the high-voltage pulse output; meanwhile, when the driving signal Bn is high, the relay Bn is switched from the normally closed contact to the normally open contact, namely COM of the relay An is conducted with the COM end of the relay Bn, so that the electrode n is conducted with the positive end of the high-voltage pulse output.

According to the invention, the voltage and current values are measured by using the alternating current signals, the impedance between the electrodes is obtained through calculation, whether the electrodes are well attached to myocardial tissues or not is confirmed through judgment of the impedance values, and the effectiveness of ablation energy reaching a target point can be improved through good attachment.

Example 2

Based on the above-described example 1, this example illustrates a typical discharge pattern combination using 6 electrodes as an example, and compares with the prior art to verify the excellent effects of the present invention.

Referring to fig. 6 to 12, the electrode discharge combinations of P1 and P2 in fig. 6, the electrode discharge combinations of P1 and P3 in fig. 7, the electrode discharge combinations of P1 and P4 in fig. 8, the electrode discharge combinations of P2 and P3 in fig. 9, the electrode discharge combinations of P1 and P5 in fig. 10, the electrode discharge combinations of P1 and P6 in fig. 11, and the electrode discharge combinations of P3 and P5 in fig. 12. By switching the electrode combination, the interval discharge, the oblique discharge, the vertical discharge and the transverse discharge are realized, so that the cross coverage of an electric field is finished, and the complete and continuous pulmonary vein isolation is realized. As shown in table 2:

table 2 shows electrode pairing

Note that: when one pair of electrodes is matched for discharging, other electrodes can be matched for discharging simultaneously (for example, when P1 and P3 are matched for vertical discharging, P2 and P4 can be matched for vertical discharging simultaneously). The number of electrodes of the pulsed electric field ablation catheter is not limited to 6, and this embodiment is merely an example.

According to the recommended optimal discharge electrode combination, the discharge electric fields of the horizontal, vertical, oblique and interval can be formed by the discharge of the switching circuit 23, the discharge combination sequence is not limited, the discharge can be completed according to the sequence of the horizontal, vertical, oblique, horizontal interval and oblique interval, the discharge sequence can also be other discharge sequences, and all the discharge electric field directions can be set with priority in software.

Further, in combination with the electrode pairing in the drawings and the tables, the comparison shows the distribution of the discharge electric field of the electrode before improvement and the difference after improvement. As shown in fig. 13, fig. 13 is a schematic diagram showing the comparison between the discharge electric field distribution of the prior art modified front electrode and the discharge electric field distribution of the electrode combination after the modification of the present invention.

The distribution of the electrode discharge electrode before improvement only has one vertical discharge mode electric field distribution state, and can be seen from the figure: the upper left and right electrodes are positive electrodes, the lower left and right electrodes are negative electrodes, and the electric field intensity at the center position is lower during discharge, and discontinuous ablation areas are generated as shown in fig. 14 and 15. And as shown in fig. 16, the amplitude of the drop in the intracardiac signal potential after ablation as measured by the mapping electrode is also not significant.

And as can be seen from the improved electrode combination discharge electric field distribution diagram, the improved electric field shows cross discharge, vertical discharge and transverse discharge superposition. As shown in FIG. 17, the middle area is overlapped by several discharge modes, and the map shows that a continuous and complete ablation area is formed after the discharge is completed, and the wall is penetrated, so that the problems that the electric field intensity of the middle area is lower and the ablation effect is discontinuous due to only one discharge mode before improvement are avoided. As shown in fig. 18, the intracardiac signal potential substantially disappears after the improvement due to the formation of electric field continuous discharge including cross discharge, vertical discharge, and lateral discharge, compared to the change of the intracardiac signal potential before the improvement.

According to the invention, through designing the electrode switching function, the discharge combinations of different modes such as cross discharge, vertical discharge, transverse discharge and the like are realized, a continuous and complete ablation area is formed after the discharge of several modes, as shown in fig. 19, and an intracardiac potential signal measured by a mapping electrode immediately disappears after the discharge is finished, so that the continuity and the integrity of the ablation area are effectively improved by the ablation scheme.

According to the invention, the electrodes which are well attached are judged to be the optimal electrode combination through software, and the optimal electrode combination discharge is realized through the switching circuit, so that the vertical, transverse, oblique and interval discharge electric fields are formed, and the ablation areas are mutually crossed and overlapped to form a continuous and complete discharge ablation effect.

The above description is only of the preferred embodiments of the present invention and it is not intended to limit the scope of the present invention, but various modifications and variations can be made by those skilled in the art. Variations, modifications, substitutions, integration and parameter changes may be made to these embodiments by conventional means or may be made to achieve the same functionality within the spirit and principles of the present invention without departing from such principles and spirit of the invention.

Claims

1. A pulsed electric field ablation system, characterized by comprising an ablation catheter (1) and an ablation device (2), the ablation catheter (1) being connected to the ablation device (2);

the ablation catheter (1) comprises an operation handle (11), a catheter main body (12) and a treatment head (13), wherein the operation handle (11) of the ablation catheter (1) is positioned at the proximal end of the catheter main body (12), and the treatment head (13) of the ablation catheter (1) is positioned at the distal end of the catheter main body (12); the proximal end of the operating handle (11) is connected with the ablation device (2) through a tail wire;

the treatment head (13) comprises a spline basket having a plurality of splines, wherein each spline comprises a plurality of electrodes, the electrodes comprising ablation electrodes and mapping electrodes;

the ablation device (2) comprises a control system.

2. A pulsed electric field ablation system according to claim 1, characterized in that the control system comprises a switching circuit (23), a high voltage pulse output circuit (24), an impedance measurement circuit (25), the high voltage pulse output circuit (24), the impedance measurement circuit (25) being interconnected with the switching circuit (23), the switching circuit (23) being connected with an ablation electrode on the spline.

3. A pulsed electric field ablation system according to claim 1 wherein the control system controls and switches the individual electrodes on the spline to any one or more pairs and to perform impedance measurements or ablations.

4. A pulsed electric field ablation system according to claim 3, wherein the impedance measurement is performed using ac voltage and ac current, the voltage value V is measured by a voltmeter and the current value I is measured by an ammeter, and the impedance Z is calculated according to the formula Z = U/I; and judging the degree of the adhesion between the electrode and the myocardial tissue by measuring the impedance between the electrodes.

5. The pulsed electric field ablation system of claim 4, wherein the electrode placement is determined based on impedance measurements, and if the impedance of a set of electrodes is small, the set of electrodes is determined to be in poor contact with myocardial tissue, and the set of electrodes is disconnected during discharge to form a recommended discharge electrode combination; if a short circuit occurs in a certain group of paired electrodes, the number of the paired electrodes with the short circuit is prompted to stop discharging.

6. The pulsed electric field ablation system of claim 4, wherein an ac signal is emitted when impedance between each set of electrodes is measured, the ac signal being adjustable in frequency, amplitude and phase.

7. The pulsed electric field ablation system of claim 6, wherein a list of impedances of different electrode combinations is measured by switching paired combinations of electrodes, and then the abutment between the current electrode and myocardial tissue pair is determined and determined by thresholding and software to form a surgically recommended electrode combination discharge plan.

8. A pulsed electric field ablation system according to any of claims 1-7, characterized in that the switching circuit (23) is configured to automatically switch the discharge by one operation, and the discharge combination sequence is not limited, so that the discharge electric fields in the transverse, vertical, oblique and interval directions can be formed, so that the discharge ablation areas are mutually overlapped in a crossing manner, and a continuous and complete discharge effect is formed, thereby realizing complete coverage of the ablation areas.

9. A pulsed electric field ablation system according to any of claims 1-7 wherein each of said electrodes corresponds to two relay switches, said relays comprising relay a and relay B, i.e. the nth electrode corresponds to relay An and relay Bn; the relay A is used for switching the positive end or the negative end of the ablation electrode corresponding to the high-voltage output; the relay B is used to switch to impedance measurement or discharge ablation.

10. The pulsed electric field ablation system of claim 9, wherein each electrode is configured to: the normally open contact of the relay An is connected to the positive end of the high-voltage pulse output, and the normally closed contact of the relay An is connected to the negative end of the high-voltage pulse output; the common end COM of the relay An is connected to a normally open contact of the relay Bn, the normally closed contact of the relay Bn is connected to An impedance measurement circuit (25), and the COM of the relay Bn is connected to An electrode Pn; the control signals of the two relays are connected to the controlled IO signals, and the IO signals drive the switching of the relays through the driving circuit.