A pulsed electric field ablation system

Abstract

This invention provides a pulsed electric field ablation system, including an ablation catheter and an ablation device, with the ablation catheter connected to the ablation device. The ablation catheter includes an operating handle, a catheter body, and a treatment head. The operating handle is located at the proximal end of the catheter body, and the treatment head is located at the distal end of the catheter body. The proximal end of the operating handle is connected to the ablation device via a tail wire. The ablation device includes a control system that can control and switch each set of electrodes for impedance measurement or ablation. By measuring voltage and current values ​​using AC signals, the impedance between electrodes is calculated. The impedance value is used to determine whether the electrodes are in good contact with the myocardial tissue. Good contact improves the effectiveness of ablation energy reaching the target point. Different electrode pairings are achieved through a switching circuit. Then, the optimal electrode combination is selected for discharge based on the judgment, forming a transverse, vertical, oblique, and intermittent discharge electric field, thus obtaining the optimal surgical ablation plan for different pulmonary vein morphologies.

Description

Technical Field

[0001] This invention relates to the field of medical devices, specifically a pulsed electric field ablation system. Background Technology

[0002] Ablation was first used to treat patients with supraventricular tachycardia who also had auxiliary pathways and Wolff-Parkinson-White syndrome. Today, ablation is also used to treat atrial flutter, atrial fibrillation, and ventricular arrhythmias.

[0003] The cornerstone of atrial fibrillation (AF) treatment is the isolation of the pulmonary veins in the left atrium, and pulsed electric field ablation has garnered widespread attention due to its superior effectiveness and safety. In AF treatment, bidirectional conduction block is primarily achieved through pulmonary vein isolation, preventing the conduction of abnormal electrical signals. The core of pulsed electric field ablation is to destroy abnormal myocardial cells using an electric field (irreversible electroporation), thereby preventing the conduction of abnormal electrocardiographic signals and achieving the goal of treating AF and other tachycardias. However, when the catheter releases the electric field through electrodes inside the heart, the impedance difference between blood and myocardial tissue, especially in poor tissue contact, leads to more electric field energy entering the bloodstream rather than targeting the myocardial tissue. In existing technologies, the electrodes only exhibit a single vertical discharge mode electric field distribution when discharging in the ablation area, resulting in discontinuous ablation zones, incomplete discharge distribution, and suboptimal ablation effects.

[0004] Patent CN114404035A discloses an ablation device with mapping function, comprising: an outer tube; an ablation assembly disposed at the distal end of the outer tube, including a radially retractable and expandable support frame and multiple electrodes disposed on the support frame; wherein at least one of the multiple electrodes is a first electrode capable of mapping; and a connector disposed at the proximal end of the outer tube, the connector including multiple conductive terminals, the connector forming an electrical connection with the multiple electrodes through the multiple conductive terminals, each of the multiple conductive terminals having at least one first terminal, each first terminal forming a one-to-one electrical connection with a corresponding first electrode, so that when the connector is connected to an external mapping device, the first electrode can be used for mapping through the first terminal. This patent enables the ablation device to have both mapping and ablation functions, solving the problem of needing to guide two devices, the ablation catheter and the mapping catheter, separately during surgery, simplifying the surgical operation. However, the ablation device in this patent cannot achieve electrode connection and uniform discharge in the ablation area, resulting in poor ablation effect in the ablation area.

[0005] Patent WO2022171149A1 discloses an ablation device, including an outer tube, a support frame, and an ablation element. The support frame is located at the distal end of the outer tube and has a radially contractible and expandable support structure. The support frame includes a load-bearing frame and connectors. The connectors are used to connect every two adjacent load-bearing rods to maintain a distance between adjacent load-bearing rods. The ablation element is located on the support frame and is used to output ablation energy to ablate the target ablation area. This patent connects adjacent load-bearing rods through connectors so that when the load-bearing frame is deformed by external force, it pulls the adjacent load-bearing rods to maintain the distance between adjacent load-bearing rods and maintain the stability of the load-bearing rod position. This makes the load-bearing frame less prone to twisting and deformation, avoids short circuits caused by excessively small distances between load-bearing rods leading to contact between ablation elements, and avoids damage to the target tissue, thereby improving ablation safety. However, this ablation device lacks a mapping function.

[0006] Patent WO2022007490A1 discloses a system for treating arrhythmias using pulsed electric field ablation technology, including a voltage pulse system console, a pacing and ECG unit, and an ablation catheter. The voltage pulse system console includes an electrical pulse generator, a controller, a human-machine interface, and a converter. The pacing and ECG unit includes a cardiac stimulator, an ECG recorder, a pacing catheter, a mapping catheter, and a connector; pacing electrical signals are synchronously transmitted to the voltage pulse system console. The ablation catheter includes a distal end, a mid-body section, and a proximal control handle connected in sequence. The ablation catheter is connected to the system console via a converter, and the pulsed electric field is transmitted to the ablated tissue through electrodes on the ablation catheter. During ablation discharge, the converter isolates the pacing and ECG unit from the pulse system console. This patent, by controlling the electrodes in the spline basket and the annular catheter for discharge ablation, can create large-area irreversible damage that is localized, linear, annular, or uniformly distributed. The ablation area breaks through the traditional annular ablation of the pulmonary vein orifice, improving ablation efficiency. However, this patent is mainly used for ablation.

[0007] Therefore, how to improve the discharge mode of the electrodes in the ablation zone so that they can generate a complete and continuous electric field in the ablation zone, release more electric field energy to myocardial tissue, and improve ablation efficiency is a technical problem that urgently needs to be solved. Summary of the Invention

[0008] To achieve the above objectives, release more electric field energy into myocardial tissue, and improve ablation efficiency, this application provides a pulsed electric field ablation system, including an ablation catheter and an ablation device, wherein the ablation catheter is connected to the ablation device;

[0009] The ablation catheter includes an operating handle, a catheter body, and a treatment head. The operating handle of the ablation catheter is located at the proximal end of the catheter body, and the treatment head of the ablation catheter is located at the distal end of the catheter body. The proximal end of the operating handle is connected to the ablation device via a tail wire.

[0010] The treatment head includes a spline basket with multiple splines, wherein each spline includes multiple electrodes, the electrodes including ablation electrodes and mapping electrodes;

[0011] The ablation device includes a control system.

[0012] Preferably, the control system includes a switching circuit, a high-voltage pulse output circuit, and an impedance measurement circuit. The high-voltage pulse output circuit and the impedance measurement circuit are interconnected with the switching circuit, and the switching circuit is connected to the ablation electrode on the spline.

[0013] Preferably, the control system controls and switches the electrodes on the spline to perform any one or more pairs and to perform impedance measurement or ablation.

[0014] Preferably, the impedance measurement uses AC voltage and AC current measurement. The voltage value V is measured by a voltmeter and the current value I is measured by an ammeter. The impedance Z is then calculated according to the formula Z = U / I. The degree of contact between the electrodes and the tissue is determined by measuring the impedance between the electrodes.

[0015] Preferably, the electrode contact degree is first determined based on the impedance measurement value. If the impedance value of a certain group of electrodes is small, it is determined that the contact between the electrode group and the myocardial tissue is poor. The electrode group is disconnected during discharge to form the recommended discharge electrode combination. If a pair of paired electrodes is short-circuited, a prompt is given and discharge is prevented. At the same time, the number of the paired electrode that is short-circuited is indicated.

[0016] Preferably, an AC signal is emitted when measuring the impedance between each group of electrodes, and the frequency, amplitude, and phase of the AC signal are all adjustable.

[0017] Preferably, by switching electrode pairings, a list of impedances for different electrode combinations is obtained by measurement. Then, by setting a threshold and using software to determine the adhesion between the current electrode and the myocardial tissue pair, the optimal discharge electrode combination is recommended.

[0018] In a preferred embodiment, the threshold setting is achieved by measuring the impedance threshold range of a pair of electrodes in the blood under X-rays, ensuring the electrodes are fully immersed in the blood (without contact with tissue) N times, and then calculating the threshold range using an averaging algorithm. Similarly, the threshold range for multiple pairs of electrodes can be calculated using the same method. The threshold setting can be completed before discharge and impedance measurement, forming a threshold specific to each patient's individual blood impedance characteristics, rather than a uniformly pre-set threshold. This avoids misjudgments caused by differences in blood impedance between individual patients.

[0019] Preferably, if more than 50% of the electrodes are not properly attached, the position of the conduit needs to be adjusted, based on the impedance measurement above. After the conduit position is adjusted, the impedance measurement is performed again to form the optimal discharge electrode combination.

[0020] Preferably, the potential of the intracardiac signal before discharge is measured by a mapping electrode, and the potential of the intracardiac signal is measured after discharge. The change in the amplitude of the intracardiac signal potential before and after discharge is used to confirm whether the ablation of myocardial tissue has been completed.

[0021] In the preferred embodiment, the switching circuit automatically switches the discharge according to the recommended optimal discharge electrode combination in one operation, and the order of the discharge combination is not limited. This can form a horizontal, vertical, oblique, and spaced discharge electric field, so that the discharge ablation areas overlap and intersect each other, forming a continuous and complete discharge effect, thereby achieving complete coverage of the ablation area.

[0022] In the preferred embodiment, the order of the discharge combination according to the recommended optimal discharge electrode combination can be freely sorted in the software: for example, discharge in the order of horizontal, vertical, diagonal, horizontal interval, diagonal interval, or discharge in other orders.

[0023] Preferably, each electrode corresponds to two relay switches, the relays including relay A and relay B, that is, the nth electrode corresponds to relay An and relay Bn; relay A is used to switch whether the ablation electrode corresponds to the positive or negative terminal of the high voltage output; relay B is used to perform impedance measurement or discharge ablation on the switch.

[0024] Preferably, each electrode is configured as follows: the normally open contact of relay An is connected to the positive terminal of the high-voltage pulse output, and the normally closed contact of relay An is connected to the negative terminal of the high-voltage pulse output; the common terminal COM of relay An is connected to the normally open contact of relay Bn, the normally closed contact of relay Bn is connected to the impedance measurement circuit, and the COM terminal of relay Bn is connected to electrode Pn; the control signals of the two relays are connected to the control IO signal, and the IO signal drives the switching of the relays through the drive circuit.

[0025] Beneficial technical effects of the present invention:

[0026] (1) The pulsed electric field ablation system disclosed in this invention has a control system with circuit switching function inside the ablation device. The control system can control and switch each group of electrodes to perform impedance measurement or ablation. By measuring the voltage and current values ​​using AC signals, the impedance between the electrodes is calculated. The impedance value is used to confirm whether the electrodes are in good contact with the myocardial tissue. Good contact can improve the effectiveness of ablation energy reaching the target point. Furthermore, by switching the pairing combination of electrodes to form different electrode combinations, the optimal electrode combination is selected for discharge based on the judgment, so that the optimal surgical ablation plan can be obtained for different pulmonary vein morphologies.

[0027] (2) By switching the circuit automatically in one operation, a horizontal, vertical, oblique and intermittent discharge electric field can be formed, so that each discharge ablation area crosses and overlaps with each other, forming a continuous and complete discharge effect, thereby achieving complete coverage of the ablation area, achieving the best ablation effect, improving surgical safety and saving surgical time.

[0028] (3) Different discharge combination modes can realize a complete and continuous electrical isolation ablation area in space, thus ensuring the long-term effectiveness of pulse electric field ablation.

[0029] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings.

[0030] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, and these are all within the protection scope of this application. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to actual scale.

[0032] Figure 1 This is a schematic diagram of the overall structure of a pulsed electric field ablation system disclosed in this invention;

[0033] Figure 2 This is a schematic diagram of the function switching of the control system circuit within the ablation device in this invention;

[0034] Figure 3 This is a schematic diagram of the electrode impedance measurement principle in this invention;

[0035] Figure 4 This is a schematic diagram of electrode impedance measurement in this invention;

[0036] Figure 5 This is a schematic diagram of the circuit framework for each electrode arrangement in this invention;

[0037] Figure 6 This is a schematic diagram of lateral discharge in a preferred embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of vertical discharge in a preferred embodiment of the present invention;

[0039] Figure 8 This is a schematic diagram of oblique discharge in a preferred embodiment of the present invention;

[0040] Figure 9 This is a schematic diagram of oblique discharge in a preferred embodiment of the present invention;

[0041] Figure 10 This is a schematic diagram of lateral interval discharge in a preferred embodiment of the present invention;

[0042] Figure 11 This is a schematic diagram of oblique interval discharge in a preferred embodiment of the present invention;

[0043] Figure 12 This is a schematic diagram of oblique interval discharge in a preferred embodiment of the present invention;

[0044] Figure 13 This is a schematic diagram comparing the discharge electric field distribution of the electrodes before the improvement of the prior art with the discharge electric field distribution of the electrode combination after the improvement of the present invention;

[0045] Figure 14 This is an anatomical diagram of the ablation process before the improvement of the vertical discharge mode;

[0046] Figure 15 This is a Masion staining map of the ablation region before the improvement of the vertical discharge mode;

[0047] Figure 16 This is an intracardiac signal potential diagram of the pre-improved vertical discharge mode;

[0048] Figure 17 These are improved cross-discharge, vertical discharge, and lateral discharge ablation diagrams.

[0049] Figure 18 These are Masion staining images of the ablation regions after the improved cross-discharge, vertical discharge, and lateral discharge processes.

[0050] Figure 19It is an improved intracardiac signal potential diagram after cross discharge, vertical discharge and transverse discharge are completed;

[0051] Among them, 1. ablation catheter; 11. operating handle; 12. catheter body; 13. treatment head; 2. ablation device; 23. switching circuit; 24. high voltage pulse output circuit; 25. impedance measurement circuit. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to help fully understand the embodiments of this application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. In addition, for clarity and brevity, descriptions of known functions and structures are omitted in the embodiments.

[0053] It should be understood that the phrase "an embodiment" or "this embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "an embodiment" or "this embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0054] Furthermore, reference numerals and / or letters may be repeated in different examples within this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed.

[0055] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" in this article describes another type of relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it are in an "or" relationship.

[0056] In this article, the term "at least one" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, "at least one of A and B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0057] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion.

[0058] Example 1

[0059] refer to Figure 1 As shown, Figure 1 This is a schematic diagram of the overall structure of a pulsed electric field ablation system disclosed in this invention. This invention describes a pulsed electric field ablation system, including an ablation catheter 1 and an ablation device 2, wherein the ablation catheter 1 is connected to the ablation device 2;

[0060] The ablation catheter 1 includes an operating handle 11, a catheter body 12, and a treatment head 13. The operating handle 11 is located at the proximal end of the catheter body 12, and the treatment head 13 is located at the distal end of the catheter body 12. The proximal end of the operating handle 11 is connected to the ablation device 2 via a tail wire. The treatment head 13 includes a spline basket with multiple splines, each spline including multiple electrodes, including ablation electrodes and mapping electrodes. The ablation device 2 is an ablation instrument, which includes a control system. The control system has a circuit switching function to realize the recommended discharge electrode combination, forming a highly efficient high-voltage pulse discharge ablation with transverse, vertical, oblique, and intermittent discharge electric fields.

[0061] refer to Figure 2 As shown, Figure 2 This is a schematic diagram of the function switching of the control system circuit within the ablation device of the present invention. The control system includes a switching circuit 23, a high-voltage pulse output circuit 24, and an impedance measurement circuit 25. The high-voltage pulse output circuit 24 and the impedance measurement circuit 25 are connected to the positive and negative terminals of the switching circuit 23, and the switching circuit 23 is connected to the ablation electrode on the spline.

[0062] Furthermore, the control system controls and switches the electrodes on the spline to perform any one or more pairs and to perform impedance measurement or ablation.

[0063] The principle of impedance measurement includes the following:

[0064] The impedance measurement employs AC voltage and AC current measurements. First, the voltage value V is measured using a voltmeter and the current value I is measured using an ammeter. Then, the impedance Z is calculated using the formula Z = U / I. (Reference) Figure 3 As shown, Figure 3This is a schematic diagram of the electrode impedance measurement principle in this invention. The impedance between electrodes P1 and P3 is Z. The voltage source DDS generates an excitation signal, which is simultaneously connected in series with an ammeter and across a voltmeter. The RC circuit and switching circuit 23 serve the functions of current limiting and switching with the high-voltage pulse output circuit 24, respectively.

[0065] Furthermore, the electrode adhesion is determined based on the impedance measurement values. If the impedance value of a certain group of electrodes is low, it is determined that the adhesion between the electrode group and the myocardial tissue is poor. The electrode group is disconnected during discharge to form the recommended discharge electrode combination. If a pair of paired electrodes is short-circuited, a prompt is given and discharge is prevented. At the same time, the number of the paired electrode that is short-circuited is indicated.

[0066] refer to Figure 4 As shown, Figure 4 This is a schematic diagram of electrode impedance measurement in this 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 contact between the electrodes and the tissue can be determined by measuring the impedance between the electrodes.

[0067] Furthermore, a sine wave is generated using a high-frequency AC signal in a fixed-frequency or swept-frequency mode. This wave passes through an RC circuit and switching circuit 23, entering electrodes P1 and P3 to form a current I. Due to the presence of impedance Z, a voltage U is generated. Since the amplitude of voltage U is relatively small, and other frequencies of electrical signals exist within the human body, it needs to pass through a signal processing circuit before entering the ADC for sampling. ADC sampling includes current and voltage sampling, converting the analog signal into a digital signal, which then enters the digital signal processing unit (DSP+FPGA). The real part a and imaginary part b of U are calculated using DFT, and then... The magnitude of voltage U is calculated, and the magnitude of I is calculated similarly. Finally, the impedance Z is obtained through Z = U / I.

[0068] Furthermore, by switching electrode pairings, a list of impedances for different electrode combinations is obtained. Then, through threshold setting and software judgment, the adhesion between the current electrodes and the myocardial tissue can be confirmed to form a surgically recommended electrode combination discharge plan. For example, if the impedance measured by electrodes P1 and P3 is within the set threshold range, it is determined that electrodes P1 and P3 have not made good contact with the tissue, and the combination of electrodes P1 and P3 will not be used during discharge.

[0069] The threshold setting is achieved as follows: the impedance threshold range of a pair of electrodes in the blood is calculated by measuring N times under X-ray with the electrodes completely immersed in the blood (without contact with tissue), and then averaging the results. Similarly, the threshold range for multiple pairs of electrodes can be calculated using the same method. The threshold setting can be completed before discharge and impedance measurement, forming a threshold characteristic specific to each patient's blood impedance, rather than a uniformly pre-set threshold. This avoids misjudgments caused by differences in blood impedance between individual patients.

[0070] Based on the impedance measurements above, if more than 50% of the electrodes are not properly attached, an automatic prompt will be issued indicating that the position of the conduit needs to be adjusted. After the position of the conduit is adjusted, the impedance measurement will be performed again to form the optimal combination of discharge electrodes before discharge.

[0071] Furthermore, the control system in the ablation device 2 performs system function switching: each electrode corresponds to two relay switches, including relay A and relay B, that is, the nth electrode corresponds to relay An and relay Bn. Relay A is used to switch whether the ablation electrode corresponds to the positive or negative terminal of the high-voltage output, and relay B is used to perform impedance measurement or discharge ablation. For example, electrode 1 corresponds to relay switch A1 and relay switch B1; electrode 2 corresponds to relay switch A2 and relay switch B2. The nth electrode corresponds to relay An and relay Bn.

[0072] refer to Figure 5 As shown, Figure 5 This is a schematic diagram of the circuit framework for each electrode in this invention. Each electrode is configured as follows: the normally open contact of relay An is connected to the positive terminal of the high-voltage pulse output; the normally closed contact of relay An is connected to the negative terminal of the high-voltage pulse output; the common terminal COM of relay An is connected to the normally open contact of relay Bn; the normally closed contact of relay Bn is connected to the impedance measurement circuit 25; and the COM terminal of relay Bn is connected to electrode Pn. The control signals for both relays are connected to the control IO signal, which drives the switching of the relays through the drive circuit. See item 2 in Table 1 below:

[0073] Table 1 shows the relay switching function table.

[0074] Serial Number Relay An state Relay Bn state Electrode n state 1 Normally open or normally closed Normally closed Connect to impedance measurement circuit 2 Normally open Normally open Connect to the positive terminal of the high voltage pulse output 3 Normally closed Normally open Connect to the negative terminal of the high voltage pulse output

[0075] When the drive signal An is high, the relay An switches from a normally closed contact to a normally open contact, that is, the COM terminal of the relay An is connected to the positive terminal of the high voltage pulse output; at the same time, when the drive signal Bn is high, the relay Bn switches from a normally closed contact to a normally open contact, that is, the COM terminal of the relay An is connected to the COM terminal of the relay Bn, thereby realizing the connection between the electrode n and the positive terminal of the high voltage pulse output.

[0076] This invention uses AC signals to measure voltage and current values, calculates the impedance between electrodes, and uses the impedance value to confirm whether the electrodes are in good contact with myocardial tissue. Good contact can improve the effectiveness of ablation energy reaching the target.

[0077] Example 2

[0078] Based on the above embodiment 1, this embodiment takes 6 electrodes as an example to illustrate a typical discharge mode combination and compares it with the prior art to verify the excellent effect of the present invention.

[0079] Combined with appendix Figure 6-12 As shown, Figure 6 The middle part is the discharge combination of P1 and P2 electrodes. Figure 7 The middle part is the discharge combination of P1 and P3 electrodes. Figure 8 The middle part is the discharge combination of P1 and P4 electrodes. Figure 9 The middle part is the discharge combination of P2 and P3 electrodes. Figure 10 The middle part is the discharge combination of P1 and P5 electrodes. Figure 11 The middle part is the discharge combination of P1 and P6 electrodes. Figure 12 The middle section uses the P3 and P5 electrode discharge combination. By switching the electrode combination, the aforementioned intermittent discharge, oblique discharge, vertical discharge, and lateral discharge are achieved, thereby completing the cross-coverage of the electric field and realizing complete and continuous pulmonary vein isolation. As shown in Table 2:

[0080] Table 2 provides an explanation of electrode pairing.

[0081]

[0082] Note: When a pair of electrodes is discharging, other electrodes can also be paired and discharged simultaneously (e.g., when P1 and P3 are paired and discharged vertically, P2 and P4 can also be paired and discharged vertically simultaneously). The number of electrodes in the pulsed electric field ablation catheter is not limited to 6; this embodiment is only an example.

[0083] According to the recommended optimal discharge electrode combination, the discharge can be generated by switching circuit 23 to form a horizontal, vertical, oblique, and intermittent discharge electric field. The order of the discharge combination is not limited. The discharge can be completed in the order of horizontal, vertical, oblique, horizontal interval, and oblique interval, or other discharge sequences. The priority of all discharge electric field directions can be set in the software.

[0084] Furthermore, referring to the attached diagram and the electrode pairings in the table above, compare the differences between the electrode discharge electric field distribution before and after the improvement. (See attached diagram.) Figure 13 As shown, Figure 13 This is a schematic diagram comparing the discharge electric field distribution of the electrodes before the improvement of the prior art with the discharge electric field distribution of the electrode combination after the improvement of the present invention.

[0085] Before the improvement, the electrode distribution only had one vertical discharge mode electric field distribution. As shown in the figure, the upper left and upper right electrodes were positive, and the lower left and lower right electrodes were negative. During discharge, the electric field strength at the center was low, resulting in discontinuous ablation regions. Figure 14 , 15 As shown. And as... Figure 16 As shown, the decrease in intracardiac signal potential after ablation, as measured by the mapping electrode, was not significant.

[0086] The improved electrode combination discharge electric field distribution diagram shows that the improved electric field exhibits superposition of cross discharge, vertical discharge, and transverse discharge. For example... Figure 17 As shown, due to the superposition of several discharge modes in the middle region, the Masion staining pattern shows that a continuous and complete ablation region is formed after the discharge is completed, and it penetrates the wall. This avoids the problem of low electric field intensity and discontinuous ablation effect in the middle region caused by only one discharge mode in the previous method. Figure 18 As shown, compared to the changes in intracardiac signal potential before the improvement, the intracardiac signal potential basically disappears after the improvement due to the continuous discharge of the electric field, which includes cross discharge, vertical discharge and transverse discharge.

[0087] This invention achieves different discharge modes, such as cross discharge, vertical discharge, and lateral discharge, through electrode switching design. After several discharge modes, a continuous and complete ablation region is formed, such as... Figure 19 As shown, the intracardiac potential signal measured by the mapping electrode immediately disappeared after the discharge was completed, indicating that the ablation scheme of the present invention effectively improved the continuity and integrity of the ablation area.

[0088] This invention uses software to determine the best electrode combination based on the well-fitting electrodes. By switching circuits, the best electrode combination is discharged, forming vertical, horizontal, oblique, and intermittent discharge electric fields. This allows the ablation areas to overlap and form a continuous and complete discharge ablation effect.

[0089] The above description is merely a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A pulsed electric field ablation system, characterized in that, It includes an ablation catheter (1) and an ablation device (2), wherein the ablation catheter (1) is connected to the ablation device (2); The ablation catheter (1) includes an operating handle (11), a catheter body (12), and a treatment head (13). The operating handle (11) of the ablation catheter (1) is located at the proximal end of the catheter body (12), and the treatment head (13) of the ablation catheter (1) is located at the distal end of the catheter body (12). The proximal end of the operating handle (11) is connected to the ablation device (2) via a tail wire. The treatment head (13) includes a spline basket with multiple splines, wherein each spline includes multiple electrodes, the electrodes including ablation electrodes and mapping electrodes; The ablation device (2) includes a control system; The control system includes a switching circuit (23), a high-voltage pulse output circuit (24), and an impedance measurement circuit (25). The high-voltage pulse output circuit (24) and the impedance measurement circuit (25) are interconnected with the switching circuit (23), and the switching circuit (23) is connected to the ablation electrode on the spline. The control system selects the pairing combination of the ablation electrodes through the switching circuit to generate a superimposed ablation electric field in the tissue area, thereby achieving complete coverage of the ablation area. The switching circuit (23) automatically switches the discharge in one operation, and the order of discharge combination is not restricted. It can form a horizontal, vertical, oblique and spaced discharge electric field, so that each discharge ablation area crosses and overlaps with each other, forming a continuous and complete discharge effect, thereby achieving complete coverage of the ablation area. The control system controls and switches the electrodes on the spline to perform any one or more pairs of pairings and to perform impedance measurement or ablation. The impedance measurement employs AC voltage and AC current measurements. A voltmeter measures the voltage value V and an ammeter measures the current value I. The impedance Z is then calculated using the formula Z=U / I. The degree of contact between the electrodes and the myocardial tissue is determined by measuring the impedance between the electrodes. First, the electrode adhesion is determined based on the impedance measurement values. If the impedance value of a certain group of electrodes is less than the threshold range, it is determined that the electrode group is not properly attached to the myocardial tissue. The electrode group is disconnected during discharge to form the recommended discharge electrode combination. If a pair of paired electrodes is short-circuited, a prompt is given and discharge is stopped. At the same time, the number of the paired electrode that is short-circuited is indicated. When measuring the impedance between each set of electrodes, an AC signal is emitted, the frequency, amplitude, and phase of which are all adjustable. By switching electrode pairings, a list of impedances for different electrode combinations is obtained. Then, by setting thresholds and using software to determine the adhesion between the current electrode and the myocardial tissue pair, a surgically recommended electrode combination discharge scheme is formed.

2. The pulsed electric field ablation system according to claim 1, characterized in that, Each electrode corresponds to two relay switches, including relay A and relay B, that is, the nth electrode corresponds to relay An and relay Bn; relay A is used to switch whether the ablation electrode corresponds to the positive or negative terminal of the high voltage output; The relay B is used to switch between impedance measurement and discharge ablation.

3. The pulsed electric field ablation system according to claim 2, characterized in that, Each electrode is configured as follows: the normally open contact of relay An is connected to the positive terminal of the high-voltage pulse output, and the normally closed contact of relay An is connected to the negative terminal of the high-voltage pulse output; the common terminal COM of relay An is connected to the normally open contact of relay Bn, the normally closed contact of relay Bn is connected to the impedance measurement circuit (25), and the COM terminal of relay Bn is connected to electrode Pn; the control signals of the two relays are connected to the control IO signal, and the IO signal drives the switching of the relays through the drive circuit.

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