Ablation system

Abstract

To provide a novel technology related to a catheter ablation method.SOLUTION: An ablation system 1 includes: a catheter 4 including three or more electrodes; a power supply part 26 that applies a voltage to a plurality of electrodes, the power supply part 26 being electrically connected to the catheter 4; and a control part 28 that divides a plurality of electrodes 18 into a plurality of electrode groups of the number less than the number of the electrodes 18 and controls the power supply part 26 so as to successively apply a voltage to each electrode group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to ablation systems. [Background technology]

[0002] Patent Document 1 discloses an ablation system including an ablation catheter and a pulse waveform generator that delivers a voltage pulse to the ablation catheter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-500170 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of extensive investigations, the present inventors have come up with a novel technique for catheter ablation.

[0005] The present disclosure has been made in light of these circumstances, and has an object to provide a novel technique related to catheter ablation. [Means for solving the problem]

[0006] One aspect of the present disclosure is an ablation system that includes a catheter having three or more electrodes, a power supply unit electrically connected to the catheter and applying a voltage to the electrodes, and a control unit that divides the electrodes into a number of electrode groups less than the number of electrodes and controls the power supply unit to sequentially apply a voltage to each electrode group.

[0007] Any combination of the above components and any conversion of the expression of the present disclosure between a method, an apparatus, a system, etc. are also valid as aspects of the present disclosure. Effect of the Invention

[0008] According to the present disclosure, a novel technique for catheter ablation can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an ablation system according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of an electrode assembly. [Diagram 3] FIG. 2 is a diagram illustrating a first example of electrode grouping. [Figure 4] Fig. 4(A) is a diagram for explaining a second example of electrode grouping, Fig. 4(B) is a diagram for explaining a third example of electrode grouping, and Fig. 4(C) is a diagram for explaining a fourth example of electrode grouping. [Diagram 5] FIG. 13 is a schematic diagram of a tip portion of a catheter according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the scale and shape of each part shown in each drawing are set for convenience to facilitate explanation, and are not to be interpreted as being limiting unless otherwise specified. In addition, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. In addition, some of the members that are not important in explaining the embodiment in each drawing are omitted.

[0011] Fig. 1 is a schematic diagram of an ablation system 1 according to an embodiment. In Fig. 1, some of the components of the ablation system 1 are depicted as functional blocks. At least some of these functional blocks can be realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program or the like. Those skilled in the art will understand that these functional blocks can be realized in various ways by combining hardware and software.

[0012] The ablation system 1 performs a predetermined ablation on an affected area 2 of a patient. An example of the affected area 2 is an organ in which arrhythmia occurs. The ablation system 1 can also be used for ablation on other affected areas 2. The ablation system 1 includes a catheter 4, a return electrode 6, and a power supply unit 8.

[0013] The catheter 4 has a shaft 10, an electrode assembly 12, and a handle 14. The shaft 10 is made of a flexible tubular body, and at least the tip side is inserted into the patient's body. The shaft 10 is made of a known flexible material including resins such as polyolefin, polytetrafluoroethylene, polyether block amide, and polyamide. The shaft 10 has a multi-lumen structure having, for example, multiple lumens. Various thin wires (not shown) such as conductors and operating wires, an inner tube 22 (see FIG. 2) described later, and the like are inserted into the lumens.

[0014] An electrode assembly 12 is provided at the tip of the shaft 10. Fig. 2 is a perspective view of the electrode assembly 12. The electrode assembly 12 has a plurality of splines 16 and three or more electrodes 18. Note that Fig. 1 illustrates the splines 16 in a folded state, and Fig. 2 illustrates the splines 16 in an expanded state.

[0015] Each spline 16 is a linear body extending in the axial direction of the shaft 10, and is made of the same flexible material as the shaft 10. The electrode assembly 12 shown in FIG. 2 has a first spline 16a, a second spline 16b, a third spline 16c, a fourth spline 16d, a fifth spline 16e, and a sixth spline 16f as an example, but the number of splines 16 is not limited to six and may be any number. In the present disclosure, when it is not necessary to distinguish the first spline 16a to the sixth spline 16f from one another, they may be simply referred to as "splines 16."

[0016] The splines 16 are arranged at intervals around the axis of the shaft 10. The distal end of each spline 16 is connected to a distal tip 20. The proximal end of each spline 16 is inserted into the shaft 10 from its distal end and fixed to the shaft 10. The distal tip 20 is connected to the distal tip 20 with the distal end of an inner tube 22 connected to the distal tip 20. The inner tube 22 is passed through the lumen of the shaft 10 and has a proximal end connected to the handle 14. The inner tube 22 can be advanced and retreated toward the distal end and proximal end of the shaft 10 by operating the handle 14.

[0017] When the inner tube 22 is pulled toward the base end of the shaft 10 with each spline 16 extending linearly, the distal tip 20 is displaced toward the base end of the shaft 10. This causes each spline 16 to curve and bulge outward, and the electrode assembly 12 assumes a basket shape. When the inner tube 22 is pushed toward the distal end of the shaft 10 with each spline 16 curved, the distal tip 20 is displaced toward the distal end of the shaft 10. This causes each spline 16 to become linear, and the electrode assembly 12 is folded. The term "basket shape" comes from the fact that the shape of the multiple splines 16 resembles the curved pattern on the surface of a basketball.

[0018] A plurality of electrodes 18 are provided on each spline 16. The plurality of electrodes 18 are arranged at a predetermined interval from each other in the longitudinal direction of the spline 16. Each electrode 18 is ring-shaped and made of a metal having good electrical conductivity, such as platinum, gold, silver, copper, aluminum, stainless steel, or an alloy thereof. The electrode assembly 12 shown in FIG. 2 has a first electrode 18a, a second electrode 18b, a third electrode 18c, and a fourth electrode 18d on each spline 16 as an example, but the number of electrodes 18 is not limited to four, and may be three or more in the entire electrode assembly 12. In the present disclosure, when it is not necessary to distinguish the first electrode 18a to the fourth electrode 18d from each other, they may be simply referred to as "electrodes 18".

[0019] The tip of a conductor wire (not shown) is connected to each electrode 18. The conductor wire is passed through the lumen of the shaft 10, and the base end is connected to a connector (not shown) of the handle 14 shown in FIG. 1. A power supply unit 8 is electrically connected to each conductor wire via the connector of the handle 14. A voltage is applied to the multiple electrodes 18 by the power supply unit 8, as will be described in detail later.

[0020] The handle 14 is provided at the base end of the shaft 10, and is disposed outside the body when the catheter 4 is used, and is grasped or operated by an operator. The handle 14 has a main body portion grasped by the operator and an operation portion for advancing and retracting the inner tube 22. By operating the operation portion, the inner tube 22 can be displaced toward the base end side relative to the shaft 10. As a result, the electrode assembly 12 in the folded state unfolds in a direction intersecting with the axis of the shaft 10. Also, by operating the operation portion, the inner tube 22 can be displaced toward the tip side relative to the shaft 10. As a result, the electrode assembly 12 in the unfolded state is folded. The connector is provided in the main body portion. The catheter 4 may have an irrigation mechanism that sprays an irrigation fluid, such as saline, from the tip during ablation.

[0021] The return electrode 6 is attached to the body surface of the patient during ablation. The return electrode 6 is also electrically connected to a power supply 8. During ablation, a voltage is applied to each electrode 18 and the return electrode 6, thereby performing ablation.

[0022] The power supply device 8 includes an input unit 24, a power supply unit 26, a control unit 28, and a display unit 30. The input unit 24 is composed of, for example, a dial, a button, a touch panel, etc., and is operated by an operator of the ablation system 1. The operator can input various setting values ​​and signals instructing operations to the power supply device 8 via the input unit 24. Note that the various setting values ​​may be preset at the time of product shipment, etc., and held in the power supply device 8. A signal indicating the setting values, etc. is sent from the input unit 24 to the control unit 28.

[0023] The power supply unit 26 supplies ablation voltage V to the electrodes 18 and the return electrode 6 in accordance with a control signal CTL sent from the control unit 28. out The power supply unit 26 is composed of a predetermined power supply circuit such as a switching regulator. The control unit 28 controls the operation of the entire power supply device 8 and executes predetermined arithmetic processing. The control unit 28 is composed of a microcomputer, for example. The control unit 28 controls the application of the voltage Vout to the electrode 18 and the counter electrode 6 by sending a control signal CTL to the power supply unit 26. The display unit 30 displays various information to the outside. The display unit 30 is composed of a liquid crystal display, a CRT display, an organic EL display, etc.

[0024] Next, the contents of the control executed by the control unit 28 will be described. The ablation system 1 of this embodiment performs ablation on the affected area 2 by irreversible electroporation (IRE). Since IRE is non-thermal, it is possible to suppress damage to tissues and nerves located around the affected area 2. For example, when performing pulmonary vein dissection to treat atrial fibrillation, it is possible to suppress damage to the esophagus and phrenic nerve around the affected area, and to suppress the occurrence of esophageal fistula and phrenic nerve paralysis.

[0025] In IRE, pulsed electric field ablation (PFA) is performed. PFA is an ablation technique that kills cells by applying a pulsed electric field generated by applying a high voltage to each electrode 18 and the return electrode 6, that is, forms a lesion in the affected area 2. The electric field tends to be reflected at the boundary between tissues. Therefore, it is possible to suppress damage to adjacent tissues when the affected area is cauterized.

[0026] When the electrode assembly 12 is inserted into the patient's body via a blood vessel or the like and placed on the affected area 2, the control unit 28 controls the power supply unit 26 to apply a voltage to each electrode 18 in sequence according to the rules described below. That is, the control unit 28 divides the electrodes 18 into a number of electrode groups G, the number of which is less than the number of the electrodes 18. The number of the electrodes 18 constituting each electrode group G is one or more, and at least one electrode group G is composed of two or more electrodes 18. The control unit 28 then controls the power supply unit 26 to apply a voltage to each electrode group G in sequence. When a plurality of electrodes 18 belong to an electrode group G, applying a voltage to the electrode group G causes the voltage to be applied to each electrode 18 simultaneously. Here, "applied simultaneously" means that the states in which the voltages are applied to the electrodes 18 overlap at least temporarily. The fact that the voltages are applied to each electrode group G in sequence can be confirmed, for example, by connecting an oscilloscope to each electrode 18.

[0027] 3 is a diagram illustrating a first example of grouping of the electrodes 18. In the first example, at least some of the electrodes 18 belonging to the same electrode group G are arranged on the same spline 16. Furthermore, the electrodes 18 of at least two electrode groups G are arranged on the same spline 16. Then, an electrode 18 belonging to another electrode group G is arranged between two electrodes 18 belonging to the same electrode group G.

[0028] For example, the first electrode 18a and the third electrode 18c on the first spline 16a are assigned to the first electrode group G1. Also, the second electrode 18b and the fourth electrode 18d on the first spline 16a are assigned to the second electrode group G2. Therefore, on the first spline 16a, the second electrode 18b belonging to the second electrode group G2 is disposed between the first electrode 18a and the third electrode 18c belonging to the first electrode group G1, and the third electrode 18c belonging to the first electrode group G1 is disposed between the second electrode 18b and the fourth electrode 18d belonging to the second electrode group G2.

[0029] Similarly, for the second spline 16b to the sixth spline 16f, the first electrode 18a and the third electrode 18c are assigned to the first electrode group G1, and the second electrode 18b and the fourth electrode 18d are assigned to the second electrode group G2. Thus, the electrode assembly 12 has 12 electrode groups G. In the present disclosure, when it is not necessary to distinguish the first electrode group G1 to the n-th electrode group Gn (n is an integer of 1 or more) from one another, they may be simply referred to as "electrode groups G."

[0030] The control unit 28 applies a voltage to the first electrode group G1 on the first spline 16a, and then applies a voltage to the second electrode group G2 on the first spline 16a. Next, the target to which the voltage is applied is shifted to the second spline 16b, and voltage is applied to the first electrode group G1 and the second electrode group G2 in that order. Thereafter, the target to which the voltage is applied is shifted to the third spline 16c to the sixth spline 16f in that order, and voltage is applied to each spline 16 in the order of the first electrode group G1 and the second electrode group G2.

[0031] The power supply unit 26 of this embodiment applies a voltage to each electrode 18 to generate a biphasic pulse (bipolar pulse). Thus, a positive voltage phase pulse and a negative voltage phase pulse are applied to each electrode 18, and the polarity of each electrode 18 alternates. The voltage amplitude value Am is, for example, 1000V or more and 4000V or less. The pulse width Δp is, for example, 0.1μs or more and 100μs or less.

[0032] As an example, the control unit 28 controls the power supply unit 26 to execute multiple rounds of sequential application of voltage, with the sequential application of voltage to the 12 electrode groups G being one round. The control unit 28 also controls the power supply unit 26 to repeat multiple sets of sequential application of voltage, with multiple rounds being one set. The number of rounds in one set and the number of sets to be repeated can be appropriately set based on experiments by the designer. For example, the number of rounds in one set is 2 to 1000 rounds, and the number of sets is 2 to 100 sets. The number of rounds may be one round, and the number of sets may be one set.

[0033] By sequentially applying a voltage to each electrode group G, it is possible to enlarge the region that can be formed by each electrode 18, compared to the case where a voltage is simultaneously applied to all of the electrodes 18, in other words, to all of the electrode groups G. This is believed to be because, when a voltage is simultaneously applied to all of the electrodes 18, the current density decreases because the current is dispersed among the multiple electrodes 18, but when a voltage is sequentially applied to each electrode group G, the current is concentrated in one electrode group G, increasing the current density.

[0034] Furthermore, when a voltage is applied to each of the electrodes 18 in sequence, the region that can be formed by each electrode 18 can be larger than when a voltage is applied to each electrode group G. However, depending on the interval between two adjacent electrodes 18 and the magnitude of the voltage applied, it is possible to form a sufficiently large region by applying a voltage to each electrode group G, for example, a region large enough to overlap with the adjacent region. In this case, the method of applying a voltage to each of the electrodes 18 in sequence may have a disadvantage of taking a longer time to complete ablation, rather than an advantage of being able to form a large region.

[0035] In contrast, by sequentially applying a voltage to the electrode group G, the time required for ablation can be shortened compared to the case where a voltage is sequentially applied to the electrodes 18 one by one. Alternatively, if the time required to complete ablation is the same, the number of times the voltage is applied can be increased compared to the case where a voltage is sequentially applied to the electrodes 18 one by one, so that the region can be made larger. In addition, compared to the case where a voltage is sequentially applied to the electrodes 18 one by one, the power supply circuit for switching the target to which the voltage is applied can be simplified. This allows the power supply device 8 to be made smaller. In addition, it also makes it easier to add more electrodes 18.

[0036] Furthermore, when a voltage is applied simultaneously to two adjacent electrodes 18, regions of the same potential overlap, and a situation may occur in which no current flows through the overlapping portion. Since no region is formed in the portion where no current flows, a gap in the region occurs between the two adjacent electrodes 18. To address this issue, in this embodiment, an electrode 18 belonging to another electrode group G is disposed between two electrodes 18 belonging to the same electrode group G. This makes it possible to prevent the same potential regions from overlapping when a voltage is applied to two electrodes 18 of the same electrode group G. Therefore, it is possible to prevent the occurrence of a gap in the region.

[0037] The same electrode 18 may be assigned to two or more different electrode groups G. For example, the first electrode 18a and the second electrode 18b are assigned to the first electrode group G1, and the second electrode 18b and the third electrode 18c are assigned to the second electrode group G2. That is, the second electrode 18b located between the first electrode 18a and the third electrode 18c is assigned to both the first electrode group G1 and the second electrode group G2. In this case, it is possible to suppress the occurrence of a gap in the region. That is, even if a gap in the region is formed between the first electrode 18a and the second electrode 18b by applying a voltage to the first electrode group G1, the gap can be filled by the region formed by the second electrode 18b when applying a voltage to the second electrode group G2.

[0038] 4(A) is a diagram illustrating a second example of grouping the electrodes 18. In the second example, at least some of the electrodes 18 belonging to the same electrode group G are arranged on different splines 16.

[0039] For example, the first spline 16a and the second spline 16b are grouped together, the third spline 16c and the fourth spline 16d are grouped together, and the fifth spline 16e and the sixth spline 16f are grouped together. The first electrodes 18a in each group are assigned to the first electrode group G1, the second electrodes 18b in each group are assigned to the second electrode group G2, the third electrodes 18c in each group are assigned to the third electrode group G3, and the fourth electrodes 18d in each group are assigned to the fourth electrode group G4. Therefore, in the second example, two electrodes 18 belonging to the same electrode group G are aligned in the axial direction of the shaft 10. More specifically, at least when the splines 16 are deployed and no force other than the force for deploying the splines 16 is applied to each spline 16, the two electrodes 18 belonging to the same electrode group G are aligned in the axial direction of the shaft 10. In the present disclosure, the two electrodes 18 being aligned in the axial direction of the shaft 10 means that at least a portion of the two electrodes 18 overlaps with each other when viewed from a direction perpendicular to the axial direction of the shaft 10.

[0040] The control unit 28 first selects the first spline 16a and the second spline 16b as targets for voltage application, and applies voltage to the first electrode group G1, the second electrode group G2, the third electrode group G3, and the fourth electrode group G4 on the splines in that order. Next, the control unit 28 shifts the targets for voltage application to the third spline 16c and the fourth spline 16d, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on the splines in that order. After that, the control unit 28 shifts the targets for voltage application to the fifth spline 16e and the sixth spline 16f, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on the splines in that order.

[0041] According to the second example, the time required for ablation can be shortened as in the first example. In addition, the power supply circuit can be simplified. Also, the interval between the regions in which the electrodes 18 are arranged on two adjacent splines 16 tends to be wider than the interval between the adjacent electrodes 18 on the same spline 16. Therefore, according to the second example, the occurrence of gaps between the regions can be further suppressed.

[0042] FIG. 4B is a diagram for explaining a third example of grouping of the electrodes 18. In the third example, at least some of the electrodes 18 belonging to the same electrode group G are arranged on different splines 16. In the third example, two electrodes 18 belonging to the same electrode group G and arranged on different splines 16 are offset in the axial direction of the shaft 10. More specifically, in a state where at least the splines 16 are deployed and no force other than the force for deploying the splines 16 is applied to each spline 16, the two electrodes 18 belonging to the same electrode group G are offset in the axial direction of the shaft 10. In the present disclosure, the two electrodes 18 being offset in the axial direction of the shaft 10 means that the two electrodes 18 do not entirely overlap each other when viewed from a direction perpendicular to the axial direction of the shaft 10.

[0043] For example, the first spline 16a and the second spline 16b are grouped together, the third spline 16c and the fourth spline 16d are grouped together, and the fifth spline 16e and the sixth spline 16f are grouped together. In each group, the first electrode 18a on one spline 16 and the fourth electrode 18d on the other spline 16 belong to a first electrode group G1. In each group, the second electrode 18b on one spline 16 and the third electrode 18c on the other spline 16 belong to a second electrode group G2. In each group, the third electrode 18c on one spline 16 and the second electrode 18b on the other spline 16 belong to a third electrode group G3. Additionally, the fourth electrode 18d on one spline 16 and the first electrode 18a on the other spline 16 in each set belong to a fourth electrode group G4.

[0044] The control unit 28 first selects the first spline 16a and the second spline 16b as targets for voltage application, and applies voltage to the first electrode group G1, the second electrode group G2, the third electrode group G3, and the fourth electrode group G4 on the splines in that order. Next, the control unit 28 shifts the targets for voltage application to the third spline 16c and the fourth spline 16d, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on the splines in that order. After that, the control unit 28 shifts the targets for voltage application to the fifth spline 16e and the sixth spline 16f, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on the splines in that order.

[0045] According to the third example, the time required for ablation can be shortened as in the second example. In addition, the power supply circuit can be simplified. According to the third example, the occurrence of gaps between regions can be suppressed more than in the second example.

[0046] 4(C) is a diagram illustrating a fourth example of grouping of the electrodes 18. In the fourth example, at least some of the electrodes 18 belonging to the same electrode group G are arranged on different splines 16. Also, in the fourth example, two electrodes 18 belonging to the same electrode group G are arranged on splines 16 that are not adjacent to each other. In other words, one of the two electrodes 18 belonging to the same electrode group G is arranged on a specific spline 16. Also, the other is arranged on another spline 16 excluding the spline 16 adjacent to that spline 16.

[0047] For example, the first spline 16a and the fourth spline 16d are grouped together, the second spline 16b and the fifth spline 16e are grouped together, and the third spline 16c and the sixth spline 16f are grouped together. In each group, the first electrodes 18a are assigned to the first electrode group G1, the second electrodes 18b are assigned to the second electrode group G2, the third electrodes 18c are assigned to the third electrode group G3, and the fourth electrodes 18d are assigned to the fourth electrode group G4. Therefore, for example, when attention is paid to the first electrode group G1 arranged in the pair of the first spline 16a and the fourth spline 16d, the two first electrodes 18a belonging to the first electrode group G1 are arranged on the first spline 16a and the fourth spline 16d that are not adjacent to each other.

[0048] The control unit 28 first selects the first spline 16a and the fourth spline 16d as targets for voltage application, and applies voltage to the first electrode group G1, the second electrode group G2, the third electrode group G3, and the fourth electrode group G4 on these splines in that order. Next, the control unit 28 shifts the targets for voltage application to the second spline 16b and the fifth spline 16e, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on these splines in that order. After that, the control unit 28 shifts the targets for voltage application to the third spline 16c and the sixth spline 16f, and applies voltage to the first electrode group G1 to the fourth electrode group G4 on these splines in that order.

[0049] The fourth example can also shorten the time required for ablation, as in the second and third examples. The power supply circuit can also be simplified. The fourth example can suppress the occurrence of gaps in the regions more than the third example. The fourth example can widen the interval between the previous application of voltage to each electrode 18 and the next application of voltage. In particular, by forming a pair of splines 16 facing each other across the inner tube 22, the interval can be further widened. As a result, the temperature of each electrode 18 can be suppressed from rising excessively.

[0050] The fourth electrode 18d on each spline 16 may be excluded from the target to which the voltage is applied. In this case, the second electrode group G2 in the first example is composed of only the second electrode 18b. The second and fourth examples do not include the fourth electrode group G4. The first electrode group G1 and the fourth electrode group G4 in the third example are composed of only the first electrode 18a. The fourth electrode 18d excluded from the target to which the voltage is applied may be used for potential measurement or as a spare when the ablation range is wide.

[0051] In the first to fourth examples, the combination of splines 16, the combination of electrodes 18, the order of voltage application, the number of electrodes 18 belonging to each electrode group G, and the like may be changed as appropriate. For example, in the third example, in each set of splines 16, the first electrode 18a on one spline 16 and the second spline 16 on the other spline 16 may be assigned to a first electrode group G1, the second electrode 18b on one spline 16 and the third electrode 18c on the other spline 16 may be assigned to a second electrode group G2, the third electrode 18c on one spline 16 and the fourth electrode 18d on the other spline 16 may be assigned to a third electrode group G3, and the fourth electrode 18d on one spline 16 and the first electrode 18a on the other spline 16 may be assigned to a fourth electrode group G4.

[0052] In the fourth example, the first spline 16a and the fifth spline 16e may be a pair, the second spline 16b and the fourth spline 16d may be a pair, and the third spline 16c and the sixth spline 16f may be a pair. The voltage application order in the first to fourth examples may be, for example, the first electrode group G1, the third electrode group G3, the second electrode group G2, and the fourth electrode group G4. The order of power supply to the electrodes 18 may be different for each electrode group G. The power supply unit 26 may apply a voltage to each electrode 18 to generate a monophasic pulse. The shapes and numbers of the splines 16 and the electrodes 18 are not limited.

[0053] It is also possible to combine the first and third examples, for example, and assign the first electrode 18a and the third electrode 18c on the first spline 16a and the first electrode 18a and the third electrode 18c on the second spline 16b to the first electrode group G1.

[0054] The configurations of the catheter 4 and the power supply device 8 can be changed as appropriate. For example, the distal end side of the shaft 10 of the catheter 4 may be bent in one direction or in multiple directions by operating the handle 14. The control of the power supply unit 26 by the control unit 28 may be realized by hardware (circuit) or software (program). When realized by software, the software is composed of a group of programs for causing a computer to execute each function. Each program may be, for example, built into the computer in advance, or may be installed into the computer from a network or a recording medium.

[0055] The above describes the embodiments of the present disclosure in detail. The above-mentioned embodiments merely show specific examples of implementing the present disclosure. The contents of the embodiments do not limit the technical scope of the present disclosure, and many design changes such as changes, additions, and deletions of components are possible within the scope of the idea of ​​the present disclosure defined in the claims. A new embodiment with a design change has the effects of each of the combined embodiments and modifications. In the above-mentioned embodiments, the contents for which such design changes are possible are emphasized by adding notations such as "in this embodiment" and "in this embodiment", but design changes are permitted even in contents without such notations. Any combination of components included in each embodiment is also valid as an aspect of the present disclosure. The hatching on the cross section of the drawing does not limit the material of the object to which the hatching is added.

[0056] (Modification) 5 is a schematic diagram of the tip of a catheter 4 according to a modified example. The catheter 4 according to the modified example does not have a spline 16 at the tip of the shaft 10, and a plurality of electrodes 18 are arranged on the shaft 10. As an example, a first electrode 18a, a second electrode 18b, a third electrode 18c, a fourth electrode 18d, a fifth electrode 18e, and a sixth electrode 18f are arranged on the shaft 10. The number of electrodes 18 can be changed as appropriate.

[0057] The control unit 28 groups the electrodes 18 such that an electrode 18 belonging to another electrode group G is disposed between two electrodes 18 belonging to the same electrode group G. For example, the first electrode 18a, the third electrode 18c, and the fifth electrode 18e are assigned to the first electrode group G1, and the second electrode 18b, the fourth electrode 18d, and the sixth electrode 18f are assigned to the second electrode group G2. Then, the control unit 28 applies a voltage to the first electrode group G1, and then applies a voltage to the second electrode group G2.

[0058] For example, the first electrode 18a and the fourth electrode 18d are assigned to the first electrode group G1, the second electrode 18b and the fifth electrode 18e to the second electrode group G2, and the third electrode 18c and the sixth electrode 18f to the third electrode group G3. The control unit 28 applies voltages to the first electrode group G1, the second electrode group G2, and the third electrode group G3 in that order. With this configuration, the same effects as those of the embodiment can be achieved.

[0059] The embodiment may be specified by the items described below. [1st item] A catheter (4) having three or more electrodes (18); a power supply unit (26) electrically connected to the catheter (4) and configured to apply a voltage to the plurality of electrodes (18); and a control unit (28) that divides the plurality of electrodes (18) into a plurality of electrode groups (G) whose number is less than the number of the electrodes (18) and controls the power supply unit (26) to sequentially apply a voltage to each electrode group (G). Ablation system (1). [Second item] The catheter (4) has a shaft (10) and a plurality of splines (16) arranged in a circumferential direction of the shaft (10), At least some of the electrodes (18) belonging to the same electrode group (G) are arranged on the same spline (16). Item 1. An ablation system (1) as described in item 1. [3rd item] The electrodes (18) of at least two electrode groups (G) are disposed on the same spline (16); An electrode (18) belonging to another electrode group (G) is disposed between two electrodes (18) belonging to the same electrode group (G); Item 2. An ablation system (1). [4th item] The catheter (4) has a shaft (10) and a plurality of splines (16) arranged in a circumferential direction of the shaft (10), At least some of the electrodes (18) belonging to the same electrode group (G) are arranged on different splines (16). Item 1. An ablation system (1) as described in item 1. [Item 5] Two electrodes (18) belonging to the same electrode group (G) and arranged on different splines (16) are offset in the axial direction of the shaft (10). Item 4. An ablation system (1). [Item 6] Two electrodes (18) belonging to the same electrode group (G) are arranged on splines (16) that are not adjacent to each other. An ablation system (1) as described in item 4 or 5. [Item 7] The catheter (4) has a shaft (10), A plurality of electrodes (18) are disposed on the shaft (10). Item 1. An ablation system (1) as described in item 1. [Item 8] An electrode (18) belonging to another electrode group (G) is disposed between two electrodes (18) belonging to the same electrode group (G); Item 7. An ablation system (1) as described in item 7. [Explanation of symbols]

[0060] 1 ablation system, 4 catheter, 8 power supply, 10 shaft, 12 electrode assembly, 16 spline, 18 electrode, 26 power supply unit, 28 control unit.

Claims

1. A catheter having three or more electrodes; a power supply unit electrically connected to the catheter and configured to apply a voltage to the electrodes; A control unit that divides the plurality of electrodes into a plurality of electrode groups less than the number of the electrodes and controls the power supply unit to sequentially apply a voltage to each electrode group. Ablation system.

2. The catheter includes a shaft and a plurality of splines arranged in a circumferential direction of the shaft, At least some of the electrodes belonging to the same electrode group are arranged on the same spline. The ablation system of claim 1 .

3. the electrodes of at least two of the electrode groups are disposed on the same spline; The electrode belonging to the same electrode group is disposed between two of the electrodes belonging to another electrode group. The ablation system of claim 2 .

4. The catheter includes a shaft and a plurality of splines arranged in a circumferential direction of the shaft, At least some of the electrodes belonging to the same electrode group are arranged on different splines. The ablation system of claim 1 .

5. Two electrodes belonging to the same electrode group and arranged on different splines are offset in the axial direction of the shaft. The ablation system of claim 4 .

6. Two electrodes belonging to the same electrode group are arranged on the splines that are not adjacent to each other. An ablation system as claimed in claim 4 or 5.

7. The catheter has a shaft. A plurality of the electrodes are disposed on the shaft. The ablation system of claim 1 .

8. The electrode belonging to another electrode group is disposed between two of the electrodes belonging to the same electrode group. The ablation system of claim 7.

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