Control method for pulse ablation catheter and pulse ablation catheter

Abstract

Provided is a readable storage medium on which a program is stored, and the program, when being executed, implements the following steps: obtaining, on the basis of a titration method, a pulse ablation index of an ablation lesion depth of a pulse ablation catheter with respect to discharge parameters; obtaining, on the basis of a titration method, a safe discharge relationship of an electrocardiogram signal variation with respect to a distance between an ablation target point of the pulse ablation catheter and an atrioventricular node and the discharge parameters; obtaining an actual distance between the ablation target point of the pulse ablation catheter and the atrioventricular node, obtaining expected discharge parameters according to the actual distance and the safe discharge relationship, and obtaining a predicted ablation lesion depth according to the expected discharge parameters and the pulse ablation index; and performing discharge on the basis of the expected discharge parameters when the predicted ablation lesion depth satisfies an expectation. Further provided is a pulse ablation catheter. With this configuration, situations such as conduction block can be effectively avoided, helping clinical operations to proceed smoothly.

Description

Control method of pulse ablation catheter and pulse ablation catheter Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a control method for a pulse ablation catheter and a pulse ablation catheter. Background Art

[0002] Supraventricular tachycardia (SVT) is a common arrhythmia caused by a rapid heartbeat. During an SVT episode, the heart rate is very fast (up to 100 beats per minute or more) and can last from a few minutes to a few days. Patients often experience symptoms such as weakness, fatigue, chest pain, shortness of breath, sweating, dizziness, and fainting. Over time, frequent episodes of SVT can weaken the heart and lead to heart failure. In extreme cases, SVT episodes can cause loss of consciousness or cardiac arrest.

[0003] Traditional cardiac radiofrequency ablation can only be performed at a distance from the atrioventricular node, and cannot be performed near the atrioventricular node. The reason is that the size and shape of the radiofrequency ablation lesion are difficult to accurately control. Radiofrequency ablation near the atrioventricular node can easily cause cardiac conduction block, which can cause death in severe cases.

[0004] Pulsed electric field ablation (PFA) is an emerging treatment for supraventricular tachycardia (SVT). This procedure uses a high-voltage (≥1000V) and short-duration (microsecond) pulsed electric field to cause target tissue damage through an irreversible electroporation mechanism. Compared to radiofrequency ablation (RFA), PFA can precisely control the total energy of the pulsed ablation by adjusting the single pulse dose (down to 0.01J) and the number of pulses. Therefore, the energy of PFA is relatively easier to quantify.

[0005] However, even though the energy of pulsed electric field ablation can be quantified, the size and depth of the pulsed electric field ablation lesion are still difficult to predict accurately, especially when ablation is performed near the atrioventricular node. When the size and depth of the ablation lesion exceed the expected range, it is easy to cause cardiac conduction block. Summary of the Invention

[0006] The object of the present invention is to provide a control method for a pulse ablation catheter and a pulse ablation catheter, so as to solve the problem that the depth of the ablation lesion is difficult to predict.

[0007] In order to solve the above technical problems, the present invention provides a readable storage medium having a program stored thereon. When the program is executed, the following steps are implemented: obtaining a pulse ablation index of the ablation lesion depth of the pulse ablation catheter in relation to discharge parameters based on a titration method; obtaining a safe discharge relationship between the distance between the ablation target of the pulse ablation catheter and the atrioventricular node and discharge parameters in relation to changes in electrocardiogram signals based on a titration method; obtaining the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, obtaining expected discharge parameters based on the actual distance and the safe discharge relationship, and obtaining a predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index; when the predicted ablation lesion depth meets expectations, performing discharge based on the expected discharge parameters.

[0008] Optionally, the discharge parameters include discharge voltage, discharge pulse width and discharge times.

[0009] Optionally, the expression of the pulse ablation index is: D = A*n a *U b *W c *ΔZ d *F e

[0010] Where D is the depth of the ablation lesion, A is a constant, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change value, F is the adhesion force value, a, b, c, d, and e are the power exponents of the parameters n, U, W, ΔZ, and F, respectively. The values ​​of a, b, c, d, and e range from 0 to 3, respectively.

[0011] Optionally, the expression of the pulse ablation index is: D = A*n a *U b *W c *ΔZ d +B*ln(F)

[0012] Where D is the depth of the ablation lesion, A and B are constants, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change value, F is the adhesion force value, a, b, c, d, and e are the power exponents of the parameters n, U, W, ΔZ, and F, respectively. The values ​​of a, b, c, d, and e range from 0 to 3, respectively.

[0013] Optionally, when the program stored on the readable storage medium is executed, the following steps are also implemented: obtaining the abutment force value of the pulse ablation catheter, and performing discharge based on the expected discharge parameters when the abutment force value is within a preset force value range.

[0014] Optionally, when the program stored on the readable storage medium is executed, the following steps are also implemented: under the premise of fixed discharge parameters, the pressure relationship between the ablation lesion depth and the contact force value of the pulse ablation catheter is obtained by titration method; in the step of obtaining the predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual contact force value of the pulse ablation catheter and the pressure relationship.

[0015] Optionally, when the program stored on the readable storage medium is executed, the following steps are also implemented: under the premise of fixed discharge parameters, the stability relationship of the ablation lesion depth with respect to the tip position of the pulse ablation catheter is obtained by titration method; in the step of obtaining the predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual tip position of the pulse ablation catheter and the stability relationship.

[0016] Optionally, the step of performing discharge based on the expected discharge parameters includes: performing a single trial discharge based on the expected discharge parameters; evaluating a result of the single trial discharge, and if the evaluation result meets a set condition, performing discharge according to the expected number of discharges.

[0017] To solve the above technical problems, the present invention also provides a pulse ablation catheter, which includes: a catheter body, an electrode and a control module; the electrode is arranged on the catheter body; the control module is configured to control the discharge of the electrode according to the program stored on the readable storage medium as described above.

[0018] Optionally, the pulse ablation catheter further includes a pressure sensor, which is disposed on the catheter body and is used to obtain an abutment force value and send it to the control module.

[0019] To summarize, in the control method of the pulse ablation catheter and the pulse ablation catheter provided by the present invention, the control method of the pulse ablation catheter includes: obtaining the pulse ablation index of the ablation lesion depth of the pulse ablation catheter with respect to the discharge parameters based on the titration method; obtaining the safe discharge relationship between the distance between the ablation target of the pulse ablation catheter and the atrioventricular node and the discharge parameters based on the change in the electrocardiogram signal; obtaining the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, obtaining the expected discharge parameters based on the actual distance and the safe discharge relationship, and obtaining the predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index; when the predicted ablation lesion depth meets expectations, performing discharge based on the expected discharge parameters.

[0020] With this configuration, the pulse ablation index, derived through titration, can be used to determine the ablation depth of a particular pulse ablation catheter under different discharge parameters. The safe discharge relationship, derived through titration, can guide the selection of safe, anticipated discharge parameters based on the actual distance between the ablation target and the atrioventricular node. When the predicted ablation depth meets expectations, discharge according to the anticipated discharge parameters can effectively avoid conduction block and other conditions, ensuring smooth clinical procedures. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0022] FIG1 is a schematic diagram of a pulse ablation catheter according to an embodiment of the present invention;

[0023] FIG2 is a schematic diagram of an ablation lesion in which a test discharge is performed on a potato using a titration method according to an embodiment of the present invention;

[0024] FIG3 is a schematic diagram of the ablation depth of a potato at different discharge voltages and discharge times based on the test discharge in FIG2 ;

[0025] FIG4 is a schematic diagram of the accuracy range of the pulse ablation index according to an embodiment of the present invention;

[0026] 5a and 5b are schematic diagrams of specific electrocardiograms of an embodiment of the present invention when a discharge voltage of 1500V is applied once near the atrioventricular node;

[0027] 5c and 5d are schematic diagrams of specific electrocardiograms obtained by discharging multiple times near the atrioventricular node with a discharge voltage of 1500V according to an embodiment of the present invention;

[0028] FIG6 is a schematic diagram showing the relationship between the distance between the ablation target and the atrioventricular node and the safe voltage according to an embodiment of the present invention;

[0029] FIG7 a is a schematic top view of an ablation lesion at different contact distances using a pulse ablation catheter according to an embodiment of the present invention;

[0030] FIG7 b is a schematic side view of the ablation lesion at different contact distances of the pulse ablation catheter according to an embodiment of the present invention;

[0031] FIG8 is a schematic diagram of performing discharge when the abutting force value is within a preset force value range according to an embodiment of the present invention;

[0032] FIG9a, FIG9b, and FIG9c are schematic diagrams showing comparisons of titration ablation depths of ablation lesions under different abutment stabilities according to an embodiment of the present invention.

[0033] In the drawings: 10 - catheter body; 11 - electrode; 111 - head electrode; 112 - ring electrode; 12 - insulation layer; 13 - pressure sensor. DETAILED DESCRIPTION

[0034] To make the objects, advantages, and features of the present invention more clearly apparent, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale. They are only used to conveniently and clearly assist in illustrating the purposes of the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may need to illustrate different focuses and sometimes use different scales.

[0035] As used in the present invention, the singular forms "a", "an", "one", and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only the endpoints. The terms "proximal end" and "distal end" are defined herein with respect to a pulse ablation catheter having one end for inserting into the human body and a control end extending outside the body. The term "proximal" refers to a location closer to the control end of a pulsed ablation catheter extending outside the body, while the term "distal" refers to a location closer to the end of the pulsed ablation catheter that enters the human body and, therefore, further away from the control end of the pulsed ablation catheter. Alternatively, in manual or hand-operated applications, the terms "proximal" and "distal" are defined herein relative to an operator, such as a surgeon or clinician. The term "proximal" refers to a location closer to the operator, while the term "distal" refers to a location closer to the pulsed ablation catheter and, therefore, further away from the operator. Furthermore, as used herein, the terms "mounted," "connected," "connected," and "disposed" of one element to another should be understood broadly, generally indicating a connection, coupling, mating, or transmission relationship between the two elements, which can be direct or indirect via an intermediate element. They should not be construed to indicate or imply a spatial positional relationship between the two elements, i.e., one element can be positioned inside, outside, above, below, or to the side of another element, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances. Additionally, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used with respect to exemplary embodiments as they are shown in the figures, with an upward or upper direction toward the top of the corresponding figure and a downward or lower direction toward the bottom of the corresponding figure.

[0036] The present invention aims to provide a control method for a pulsed ablation catheter, a readable storage medium, and a pulsed ablation catheter to solve the problem of difficulty in predicting the depth of an ablation lesion.

[0037] Referring to FIG1 , an embodiment of the present invention provides a pulsed ablation catheter, comprising a catheter body 10, an electrode 11, and a control module (not shown). The electrode 11 is disposed on the catheter body 10, and the control module is configured to control the discharge of the electrode 11. In an alternative embodiment, the electrode 11 comprises a tip electrode 111 and a plurality of ring electrodes 112 (the embodiment shown in FIG1 includes three ring electrodes, namely, ring electrode 112a, ring electrode 112b, and ring electrode 112c). The tip electrode 111 is disposed at the distal end of the catheter body 10 (the left end in FIG1 ). The tip electrode 111 has a diameter of 1.5 mm to 3 mm, and a width (indicated by the axial distance) of 1 mm to 4 mm. The ring electrodes 112 have a diameter of 1.5 mm to 3 mm, and a width (indicated by the axial distance) of 0.5 mm to 4 mm. Preferably, the pulse ablation catheter further includes a plurality of insulating layers 12, which are disposed between the head electrode 111 and the plurality of ring electrodes 112 to separate the electrodes (including the head electrode 111 and the ring electrodes 112). It should be noted that the pulse ablation catheter shown in FIG1 is merely an example of a pulse ablation catheter and does not limit the structure of the pulse ablation catheter. Those skilled in the art may improve the structure of the pulse ablation catheter based on actual needs, and the present invention is not limited thereto.

[0038] In order to solve the problem of difficulty in predicting the depth of ablation lesions, an embodiment of the present invention provides a control method for a pulse ablation catheter, which includes:

[0039] Step S1: obtaining a pulse ablation index of the ablation lesion depth of the pulse ablation catheter with respect to discharge parameters based on a titration method;

[0040] Step S2: obtaining the safe discharge relationship between the distance between the ablation target point of the pulse ablation catheter and the atrioventricular node and the discharge parameters based on the change of the electrocardiogram signal using a titration method;

[0041] Step S3: obtaining the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, obtaining expected discharge parameters based on the actual distance and the safe discharge relationship, and obtaining a predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index;

[0042] Step S4: When the predicted ablation lesion depth meets expectations, discharge is performed based on the expected discharge parameters.

[0043] Titration is an effective method for quantifying ablation lesion depth and ECG signal changes. Due to the energy controllability of pulsed electric field ablation and the small energy of a single pulse discharge, different pulse energies can be used to titrate ablation to obtain the corresponding ablation lesion depth and ECG signal changes. This can then be used to determine the relationship between the pulse ablation index and safe discharge, thereby guiding actual ablation procedures.

[0044] If the energy of a single pulsed electric field discharge is sufficiently low, all discharge parameters can be exhausted, and theoretically, the ablation lesion depth of a specific pulsed ablation catheter or type of pulsed ablation catheter under various discharge parameters can be determined. For the same pulsed ablation catheter or type of pulsed ablation catheter, by setting different discharge parameters to ablate a test object (such as a potato or animal), and then measuring the ablation lesion depth under different discharge parameters after ablation, the pulsed ablation index under these discharge parameters can be obtained.

[0045] Furthermore, in the prior art, ablation near the atrioventricular node of the heart is an industry pain point, which can easily cause problems such as electrocardiogram conduction block. In view of the changes in electrocardiogram signals, in areas that are prone to electrocardiogram conduction block, such as near the atrioventricular node of the heart, the safe discharge relationship at different distances can be obtained based on the data of titration ablation in in vitro experiments or animal experiments. Then, based on the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, combined with the safe discharge relationship, appropriate expected discharge parameters can be selected. Based on the expected discharge parameters and the pulse ablation index, the expected ablation lesion depth can be predicted. Then, when the predicted ablation lesion depth meets the expectations, discharge is performed according to the expected discharge parameters, which can effectively avoid conduction block and other situations, and help clinical operations proceed smoothly.

[0046] In an alternative example, step S1 can be implemented by testing the test object (such as potatoes) in vitro using a titration method. Specific details are as follows:

[0047] By using the control variable method, only the number of discharges or the discharge voltage is changed, and other discharge parameters are fixed, and a test discharge is performed on a potato, the depth of the ablation lesion in the potato will change. Optionally, the discharge parameters here include discharge voltage, discharge pulse width, and number of discharges. By performing test discharges on potatoes at different discharge times or discharge voltages, and actually measuring the depth of the ablation lesion at different discharge times or discharge voltages, the relationship between the depth of the ablation lesion and the number of discharges or discharge voltages can be obtained. In an exemplary embodiment, as shown in Figures 2 and 3, tests were performed at three discharge voltages of 1000V, 1100V, and 1200V, with discharges of 10 times, 20 times, 30 times, and 40 times, respectively. The results showed that under the premise of fixing other discharge parameters, increasing the discharge voltage or increasing the number of discharges will increase the depth of the ablation lesion.

[0048] It should be noted that the examples shown in FIG. 2 and FIG. 3 are only tested by controlling the discharge voltage and the number of discharges. In other embodiments, the discharge voltage or the number of discharges may be fixed and the test may be performed by controlling the discharge pulse width.

[0049] In a preferred embodiment, based on the data obtained by titration of the test object in vitro, the expression of the pulse ablation index is proposed as follows: D = A*n a *U b *W c *ΔZ d *F e

[0050] Where D is the ablation lesion depth, A is a constant, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change, and F is the contact force. a, b, c, d, and e are the exponents of the parameters n, U, W, ΔZ, and F, respectively. The exponents a, b, c, d, and e range from 0 to 3, respectively. The impedance change ΔZ can be detected by the impedance detection module installed on the pulse ablation catheter. The contact force F can be detected by the force detection module installed on the pulse ablation catheter. The constant A and the exponents a, b, c, d, and e can be obtained by fitting the measured data using the titration method. As shown in Figure 4, the accuracy of the ablation lesion depth calculated using the expression for the pulse ablation index is ≤1 mm.

[0051] In another preferred embodiment, based on the data obtained by titration of the test object in vitro, the expression of the pulse ablation index is proposed as follows: D = A*n a *U b *W c *ΔZ d +B*ln(F)

[0052] Where D is the ablation lesion depth, A and B are constants, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change, and F is the contact force. a, b, c, d, and e are the exponents of the parameters n, U, W, ΔZ, and F, respectively, with values ​​ranging from 0 to 3. The impedance change ΔZ can be measured by the impedance detection module installed on the pulse ablation catheter. The contact force F can be measured by the force detection module installed on the pulse ablation catheter. The constants A and B and the exponents a, b, c, d, and e can be obtained by fitting the measured data using the titration method.

[0053] Optionally, step S2 can be implemented by using a titration method in animal experiments. The details are as follows:

[0054] Using the controlled variable method, only the number of discharges or the discharge voltage is changed, and other discharge parameters are fixed. When the animals are tested and discharged, the ECG signals of the animals will change in different ways. In severe cases, conduction blocks may occur. Some more serious conduction blocks may even be irreversible, as shown in Table 1:

[0055] Table 1

[0056] Please refer to Figures 5a and 5b, which are specific electrocardiogram diagrams of a discharge voltage of 1500V near the atrioventricular node. The electrocardiogram diagram of Figure 5a shows that after the discharge voltage of 1500V is discharged once, the electrocardiogram changes from a normal electrocardiogram signal to a conduction block. The electrocardiogram diagram of Figure 5b shows that after a few minutes of conduction block caused by the completion of the discharge, the electrocardiogram signal returns to a normal heart rhythm.

[0057] Please refer to Figures 5c and 5d, which are specific electrocardiogram diagrams of multiple discharges with a discharge voltage of 1500V near the atrioventricular node. The electrocardiogram diagram of Figure 5c shows that after multiple discharges with a discharge voltage of 1500V, the electrocardiogram changes from a normal electrocardiogram signal to a conduction block. The electrocardiogram diagram of Figure 5d shows that the electrocardiogram signal does not return to a normal rhythm for a long time after the completion of the discharge-induced conduction block.

[0058] Furthermore, the distance between the ablation target and the AV node (i.e., the His bundle) can also affect ECG signal changes. A controlled variable approach can be used to vary only the distance between the ablation target and the AV node and the discharge voltage, while keeping other discharge parameters constant, and then test discharges in animals.

[0059] Referring to Figure 6, in an alternative example, the distance between the ablation target and the AV node is selected to be 2mm to 10mm. Discharge ablation is performed using different discharge voltages at each distance. The maximum voltage that can be applied at each distance without causing ECG signal conduction block is determined as the benchmark. This benchmark maximum voltage is the safe voltage at that distance. This provides the safe discharge relationship, or the relationship between the distance from the ablation target to the AV node and the discharge voltage. As shown in Figure 6, overall, the safe voltage increases with increasing distance from the AV node.

[0060] It should be noted that the example shown in FIG. 6 only controls the discharge voltage for testing. In other embodiments, the discharge voltage may be fixed and the test may be performed by controlling the discharge times or the discharge pulse width.

[0061] After the pulse ablation index and the safe discharge relationship are obtained based on step S1 and step S2, step S3 can be used in actual ablation. In step S3, the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node can be measured, for example, by a three-dimensional mapping module. In an alternative exemplary embodiment, a three-dimensional model of the heart can be performed before the operation, and then after the pulse ablation catheter is inserted into the body, the position of the distal end of the pulse ablation catheter can be obtained by a three-dimensional mapping module, thereby obtaining the actual distance between the ablation target and the atrioventricular node. The specific principle can be referred to the prior art, and the present invention will not elaborate on this.

[0062] After obtaining the actual distance between the ablation target and the atrioventricular node, the current safe discharge parameters (including safe voltage, safe pulse width, and safe discharge times) can be determined based on the safe discharge relationship obtained in step S2. By selecting appropriate expected discharge parameters based on the safe discharge parameters, the discharge voltage and pulse width can be controlled within a safe range, effectively reducing or avoiding the occurrence of conduction block and other conditions, thereby improving ablation safety.

[0063] Furthermore, after determining the expected discharge parameters, the predicted ablation lesion depth can be inferred from the pulse ablation index. It is understood that the predicted ablation lesion depth is the theoretically calculated ablation lesion depth corresponding to the expected discharge parameters. The predicted ablation lesion depth can be compared with an expected value or expected range. For example, during preoperative evaluation, an expected value or expected range can be set for the ablation lesion depth. If the predicted ablation lesion depth matches the expected value or is within the expected range, the predicted ablation lesion depth is considered to meet expectations, and discharge can be performed based on the expected discharge parameters. In some embodiments, the predicted ablation lesion depth can also be provided to the operator for reference, allowing the operator to determine whether discharge is necessary.

[0064] With this configuration, the pulse ablation index, derived through titration, can be used to determine the ablation depth of a particular pulse ablation catheter under different discharge parameters. The safe discharge relationship, derived through titration, can guide the selection of safe, anticipated discharge parameters based on the actual distance between the ablation target and the atrioventricular node. When the predicted ablation depth meets expectations, discharge according to the anticipated discharge parameters can effectively avoid conduction block and other conditions, ensuring smooth clinical procedures.

[0065] Optionally, in the pulse ablation catheter provided in this embodiment, the control module is configured to control the discharge of the electrode 11 according to the control method of the pulse ablation catheter as described above.

[0066] Please continue to refer to Figure 1. Preferably, the pulse ablation catheter also includes an impedance detection module and / or a force detection module. The force detection module may include a pressure sensor 13, which is provided on the catheter body 10. The pressure sensor 13 is used to obtain the contact force value and send it to the control module. In an alternative exemplary embodiment, the electrode 11 of the pulse ablation catheter includes a ring electrode 112a, a ring electrode 112b and a ring electrode 112c arranged in sequence from the distal end to the proximal end, and the pressure sensor 13 is located between the ring electrode 112a and the ring electrode 112b. Preferably, the pressure sensor 13 is covered by an insulating layer 12. Preferably, the spacing between the head electrode 111 and the ring electrode 112a is 1mm to 3mm, the spacing between the ring electrode 112a and the ring electrode 112b is 4mm to 7mm, and the spacing between the ring electrode 112b and the ring electrode 112c is 1mm to 3mm. The setting of the impedance detection module can refer to the existing technology and will not be described in detail here.

[0067] During use, the electrode that actually performs the discharge can be selected among the electrodes 11. For example, in some embodiments, the head electrode 111 can discharge the ring electrode 112b and the ring electrode 112c. In other embodiments, the head electrode 111 can also discharge the ring electrode 112a, the ring electrode 112b and the ring electrode 112c. Optionally, an irrigation hole can be provided on the head electrode 111 to perform saline irrigation. Optionally, a temperature sensor can be provided on the head electrode 111 to perform the function of monitoring tissue temperature. Optionally, the head electrode 111 can be annular in the circumferential direction and can be placed inside or outside the insulating layer 12. Optionally, the distal end of the head electrode 111 can be provided with a groove toward the proximal end to perform the function of gathering the energy of the head end. Optionally, a position sensor can be provided at the distal end of the catheter body 10 to facilitate the three-dimensional mapping module to obtain the distal position information of the catheter body 10.

[0068] The pressure sensor 13 is provided to obtain the abutment force value of the catheter body 10 relative to the ablation target, and the abutment force value can be provided to the operator for reference.

[0069] In some embodiments, factors influencing the ablation lesion depth also include the pulsed ablation catheter's contact distance, contact force, contact angle, or contact stability. As shown in Figures 7a and 7b, when only the contact distance and / or contact force are changed while other discharge parameters are fixed, a test discharge is performed on a potato, and the ablation lesion depth of the potato also changes.

[0070] Figures 7a and 7b show the ablation lesion results when the tip of the pulsed ablation catheter was in good contact with the potato surface (i.e., the contact distance) at 0 mm, 2 mm, and 4 mm, respectively. 0 mm indicates that the tip of the pulsed ablation catheter was in good contact with the potato surface (the contact force was 5 g to 10 g), and the ablation lesion depth was approximately 5 mm. 2 mm and 4 mm indicate that the tip of the pulsed ablation catheter was not in good contact with the potato surface, and the ablation lesion depths were approximately 3 mm and 1 mm, respectively. Overall, the sum of the ablation lesion depth and the distance between the tip of the pulsed ablation catheter and the potato surface was approximately 5 mm. It can be understood that when the tip of the pulsed ablation catheter is in good contact with the potato (i.e., when the contact distance is relatively small and the contact force is within an appropriate range), the ablation lesion depth can be effectively increased.

[0071] In actual clinical practice, because the patient's heart is constantly beating, it is difficult for the operator to maintain a constant contact force between the pulse ablation catheter and the ablation target. Most of the time, the contact force fluctuates with the heart cycle. In the pulse ablation catheter provided in this embodiment, the control module can implement the function of automatically discharging when a preset force value range is met based on the contact force value obtained by the pressure sensor 13. Optionally, the control method of the pulse ablation catheter also includes: obtaining the contact force value of the pulse ablation catheter, and when the contact force value is within the preset force value range, performing discharge based on the expected discharge parameters.

[0072] The preset force value interval can be set according to different ablation sites. For example, corresponding to different ablation sites, the preset force value interval can be set to a low force value interval [0g~10g), a medium force value interval [10g~30g) and a high force value interval [30g~100g]. When the contact force value falls within the preset force value interval corresponding to the corresponding ablation site, discharge can be automatically performed. Furthermore, a reference example of automatically performing discharge when the contact force value is within the preset force value interval is as follows: for each heartbeat cycle, the R wave signal is used as a reference, and after the R wave is delayed for a period of time (such as 0~500ms), a force value judgment is performed. If the contact force value is within the preset force value interval, discharge is performed, as shown in Figure 8.

[0073] Optionally, the control method of the pulse ablation catheter further includes:

[0074] Step S51: Under the premise of fixing the discharge parameters, obtaining the pressure relationship between the ablation lesion depth and the abutment force value of the pulse ablation catheter by titration method;

[0075] Step S52: In the step of obtaining the predicted ablation lesion depth according to the expected discharge parameters and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual abutment force value of the pulse ablation catheter and the pressure relationship.

[0076] Step S51, similar to steps S1 and S2, can be implemented by titrating a test object (e.g., a potato). For example, only the contact force value can be varied, while other discharge parameters are fixed, and a test discharge can be performed on a potato to determine the pressure relationship between the ablation lesion depth and the contact force value. Furthermore, in step S52, the actual contact force value obtained by pressure sensor 13, combined with the pressure relationship obtained in step S51, can be used to correct the predicted ablation lesion depth, further improving the accuracy of the predicted ablation lesion depth.

[0077] Optionally, the control method of the pulse ablation catheter further includes:

[0078] Step S61: Under the premise of fixing discharge parameters, obtaining the stability relationship between the ablation lesion depth and the tip position of the pulse ablation catheter by titration method;

[0079] Step S62: In the step of obtaining the predicted ablation lesion depth according to the expected discharge parameters and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual tip position of the pulse ablation catheter and the stability relationship.

[0080] Step S61 is similar to the aforementioned steps S1 and S2 and can be implemented by testing a test object (e.g., a potato) using a titration method. For example, only the contact stability can be changed, while other discharge parameters are fixed, and a test discharge can be performed on a potato to obtain a stability relationship between the ablation lesion depth and the contact stability. Furthermore, in step S62, the contact stability of the actual tip position of the ablation catheter can be obtained using a position sensor and a three-dimensional mapping module. Combined with the stability relationship, the predicted ablation lesion depth can be corrected, which can further improve the accuracy of the predicted ablation lesion depth.

[0081] Please refer to Figures 9a to 9c, which show the titration ablation comparison of the ablation lesion depth under different contact stability. Specifically, in the examples shown in Figures 9a to 9c, three groups of titration ablation comparisons with different contact stability were performed. The first group G1 was to discharge at a fixed position (single-point discharge), the second group G2 was to perform multiple-point discharges in a certain area (regional multi-point discharge), and the third group G3 was to discharge continuously at a certain position until one of the points turned red. They are represented in the figure as G1, G2 and G3 respectively. The number of discharges in the first group G1 and the second group G2 was 20 times, and the number of discharges in the third group G3 was 40 times. Comparing the ablation lesion results of the three groups, it was found that the depths of the ablation lesions of the three groups were respectively 6.8mm for the first group G1, 5.5mm for the second group G2, and 7.8mm for the third group G3. This means that for the same 20 discharges, the ablation lesions of the first group G1 with single-point discharge (i.e., good adhesion stability) will be deeper; and if the adhesion stability is not good (such as the third group G3), it is necessary to increase the number of discharges at a certain position to achieve the ablation lesion depth with good adhesion stability. Optionally, the adhesion stability can also be quantified according to certain rules, such as by setting a weight coefficient according to the number of discharge points for quantification. Those skilled in the art can make settings according to actual conditions to obtain a quantifiable and comparable stability relationship between the depth of the ablation lesion and the adhesion stability.

[0082] Optionally, in step S4, the step of performing discharge based on the expected discharge parameter includes:

[0083] Step S41: performing a single test discharge based on the expected discharge parameters;

[0084] Step S42: Evaluate the result of a single test discharge. If the evaluation result meets the set conditions, discharge is performed according to the expected number of discharges.

[0085] Since the expected discharge parameters are theoretically calculated based on data obtained from in vitro titration experiments, the effectiveness and safety of discharging according to the expected discharge parameters can be evaluated through a test discharge. First, a single test discharge is performed according to step S41. Here, a single test discharge means that the number of discharges is fixed to 1, and the other discharge parameters are set according to the expected discharge parameters calculated in steps S1 to S3.

[0086] In step S42, the results of the single test discharge are evaluated. This evaluation step can be performed based on pre-set conditions (such as whether the ECG signal exhibits conduction block). In practice, this evaluation can be performed using a program built into the control module, or manually by the operator. This embodiment does not limit the implementation method of the evaluation. If the evaluation result meets the set conditions, discharge is performed according to the expected number of discharges in the expected discharge parameters calculated in steps S1 through S3.

[0087] Based on the above-described method for controlling a pulsed ablation catheter, an embodiment of the present invention further provides a readable storage medium having a program stored thereon. When executed, the program implements the steps of the above-described method for controlling a pulsed ablation catheter. The readable storage medium may be provided independently or attached to the pulsed ablation catheter, for example, attached to a control module of the pulsed ablation catheter, although this is not a limitation of the present invention.

[0088] In summary, in the control method, readable storage medium, and pulse ablation catheter provided by the present invention, the control method of the pulse ablation catheter includes: obtaining a pulse ablation index of the ablation lesion depth of the pulse ablation catheter with respect to discharge parameters based on a titration method; obtaining a safe discharge relationship between the distance between the ablation target of the pulse ablation catheter and the atrioventricular node and discharge parameters based on changes in the electrocardiogram signal; obtaining the actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, obtaining expected discharge parameters based on the actual distance and the safe discharge relationship, and obtaining a predicted ablation lesion depth based on the expected discharge parameters and the pulse ablation index; when the predicted ablation lesion depth meets expectations, performing discharge based on the expected discharge parameters. With such a configuration, by obtaining the pulse ablation index by titration, the ablation lesion depth of a certain type of pulse ablation catheter under different discharge parameters can be obtained. By obtaining the safe discharge relationship by titration, the selection of safe expected discharge parameters can be guided based on the actual distance between the ablation target and the atrioventricular node. Furthermore, when the predicted ablation lesion depth meets expectations, discharge is performed according to the expected discharge parameters, which can effectively avoid conduction block and other situations and help the clinical operation proceed smoothly.

[0089] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the present invention.

Claims

1. A readable storage medium having a program stored thereon, characterized in that: When the program is executed, the following steps are performed: Obtaining the pulse ablation index of the pulse ablation catheter's ablation lesion depth in relation to discharge parameters based on the titration method; Obtaining the relationship between the distance between the ablation target of the pulse ablation catheter and the atrioventricular node and the safe discharge parameters based on the change of the ECG signal using the titration method; Obtaining an actual distance between the ablation target of the pulse ablation catheter and the atrioventricular node, obtaining an expected discharge parameter based on the actual distance and the safe discharge relationship, and obtaining a predicted ablation lesion depth based on the expected discharge parameter and the pulse ablation index; When the predicted ablation lesion depth meets expectations, discharge is performed based on the expected discharge parameters.

2. The readable storage medium according to claim 1, wherein The discharge parameters include discharge voltage, discharge pulse width and discharge times.

3. The readable storage medium according to claim 1, wherein The expression of the pulse ablation index is: D = A*n a *U b *W c *ΔZ d *F e Where D is the depth of the ablation lesion, A is a constant, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change value, F is the adhesion force value, a, b, c, d, and e are the power exponents of the parameters n, U, W, ΔZ, and F, respectively. The values ​​of a, b, c, d, and e range from 0 to 3, respectively.

4. The readable storage medium according to claim 1, wherein The expression of the pulse ablation index is: D = A*n a *U b *W c *ΔZ d +B*ln(F) Where D is the depth of the ablation lesion, A and B are constants, n is the number of discharges, U is the discharge voltage, W is the discharge pulse width, ΔZ is the impedance change value, F is the adhesion force value, a, b, c, d, and e are the power exponents of the parameters n, U, W, ΔZ, and F, respectively. The values ​​of a, b, c, d, and e range from 0 to 3, respectively.

5. The readable storage medium according to claim 1, wherein When the program is executed, the following steps are also performed: The abutment force value of the pulse ablation catheter is acquired, and when the abutment force value is within a preset force value range, discharge is performed based on the expected discharge parameter.

6. The readable storage medium according to claim 1, wherein When the program is executed, the following steps are also performed: Under the premise of fixed discharge parameters, the pressure relationship between the depth of the ablation lesion and the abutment force value of the pulse ablation catheter is obtained by titration method; In the step of obtaining the predicted ablation lesion depth according to the expected discharge parameter and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual abutment force value of the pulse ablation catheter and the pressure relationship.

7. The readable storage medium according to claim 1, wherein: When the program is executed, the following steps are also performed: Under the premise of fixed discharge parameters, the stability relationship between the ablation lesion depth and the tip position of the pulse ablation catheter is obtained by titration method; In the step of obtaining the predicted ablation lesion depth according to the expected discharge parameters and the pulse ablation index, the predicted ablation lesion depth is corrected based on the actual tip position of the pulse ablation catheter and the stability relationship.

8. The readable storage medium according to claim 1, wherein: The step of performing discharge based on the expected discharge parameter comprises: performing a single test discharge based on the expected discharge parameters; Evaluate the results of a single test discharge. If the evaluation result meets the set conditions, discharge is performed according to the expected number of discharges.

9. A pulse ablation catheter, characterized in that: include: Catheter body, electrodes and control module; The electrodes are arranged on the catheter body; The control module is configured to control the discharge of the electrodes according to the program stored on the readable storage medium according to any one of claims 1 to 8.

10. The pulse ablation catheter according to claim 9, characterized in that: The pulse ablation catheter further includes a pressure sensor, which is disposed on the catheter body and is used to obtain an abutment force value and send the value to the control module.

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