Power supply device and ablation system

Abstract

To provide a new technique related to catheter ablation.SOLUTION: A power supply device 8 includes a power supply part 26 which is electrically connected to a catheter 4 having a plurality of electrodes and applies a voltage to the plurality of electrodes, and a control part 28 which controls the power supply part 26 so as to apply a voltage to a part of the electrodes continuously a plurality of times and subsequently apply a voltage to the other electrodes continuously a plurality of times.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power supply and an ablation system. [Background technology]

[0002] Patent Document 1 discloses an ablation system including an ablation catheter and a pulse waveform generator that delivers voltage pulses 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 research, 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 its purpose is to provide a novel technique related to catheter ablation. [Means for solving the problem]

[0006] One aspect of the present disclosure is a power supply device that includes a power supply unit electrically connected to a catheter having multiple electrodes and that applies a voltage to the multiple electrodes, and a control unit that controls the power supply unit to apply a voltage multiple times in succession to some of the electrodes and then apply a voltage multiple times in succession to other electrodes.

[0007] Another aspect of the present disclosure is an ablation system, comprising a catheter having a plurality of electrodes and the power supply device of the above aspect.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, a novel technique for catheter ablation can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an ablation system according to an embodiment. [Figure 2] FIG. 2 is a perspective view of an electrode assembly. [Figure 3] FIG. 4 is a diagram showing a first example of the timing of applying voltage to each electrode. [Figure 4] FIG. 10 is a diagram showing a second example of the timing of applying voltages to the electrodes. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure will be described below with reference to preferred embodiments and drawings. 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, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0012] 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 using elements and circuits such as a computer CPU and memory, and as a software configuration using 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.

[0013] The ablation system 1 performs a predetermined ablation on an affected area 2 of a patient. The affected area 2 may be, for example, an organ in which arrhythmia is occurring. 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 8.

[0014] The catheter 4, as an example, 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 distal end 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, for example, having multiple lumens. Various thin wires (not shown), such as conducting wires and operating wires, as well as an inner tube 22 (see FIG. 2), which will be described later, are inserted into the lumens.

[0015] 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 a plurality of electrodes 18. Note that Fig. 1 illustrates the splines 16 in a folded state, while Fig. 2 illustrates the splines 16 in an unfolded state.

[0016] 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, as an example, 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, but the number of splines 16 is not limited to six and may be any plural number. In the present disclosure, when there is no need to distinguish the first spline 16a to the sixth spline 16f from one another, they may be simply referred to as "splines 16."

[0017] 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 end of an inner tube 22. The inner tube 22 is passed through the lumen of the shaft 10, and its proximal end is 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.

[0018] When the inner tube 22 is retracted toward the base end of the shaft 10 with each spline 16 extended 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.

[0019] Each spline 16 is provided with a plurality of electrodes 18. The plurality of electrodes 18 are arranged at predetermined intervals along the longitudinal direction of the spline 16. Each electrode 18 is ring-shaped and made of a metal with good electrical conductivity, such as platinum, gold, silver, copper, aluminum, or 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. However, the number of electrodes 18 is not limited to four, and may be at least one. In the present disclosure, when it is not necessary to distinguish the first electrode 18a to the fourth electrode 18d from one another, they may be simply referred to as "electrodes 18."

[0020] The tip of a conductor (not shown) is connected to each electrode 18. The conductor is passed through the lumen of the shaft 10, and the proximal end is connected to a connector (not shown) of the handle 14 shown in FIG. 1. A power supply 8 is electrically connected to each conductor via the connector of the handle 14. A voltage is applied to the plurality of electrodes 18 by the power supply 8, as will be described in detail later.

[0021] The handle 14 is provided at the base end of the shaft 10, and is disposed outside the body when the catheter 4 is in use, to be grasped or operated by the operator. The handle 14 has a main body portion grasped by the operator and an operating portion for advancing and retracting the inner tube 22. By operating the operating portion, the inner tube 22 can be displaced toward the base end relative to the shaft 10, thereby unfolding the electrode assembly 12, which is in a folded state, in a direction intersecting the axis of the shaft 10. Furthermore, by operating the operating portion, the inner tube 22 can be displaced toward the tip end relative to the shaft 10, thereby unfolding the electrode assembly 12, which is in an unfolded state. A connector is provided in the main body portion. The catheter 4 may have an irrigation mechanism that sprays irrigation fluid, such as saline, from the tip during ablation.

[0022] The return electrode 6 is attached to the patient's body surface 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.

[0023] 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 configured with, for example, a dial, a button, a touch panel, etc., and is operated by the 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 set in advance, such as at the time of product shipment, and stored 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.

[0024] The power supply unit 26 applies an ablation voltage V to the electrode 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 configured with 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 configured with a microcomputer, for example. The control unit 28 controls the application of voltage Vout to the electrode 18 and the return electrode 6 by sending a control signal CTL to the power supply unit 26. The display unit 30 displays various types of information to the outside. The display unit 30 is configured with a liquid crystal display, a CRT display, an organic EL display, etc.

[0025] Next, the content 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). Because 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 isolation 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 complications such as esophageal fistula and phrenic nerve paralysis.

[0026] 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, i.e., forms a lesion in the affected area 2. The electric field tends to be reflected at the boundaries between tissues. This makes it possible to suppress damage to adjacent tissues when cauterizing the affected area.

[0027] After the electrode assembly 12 is inserted into the patient's body via a blood vessel or the like and positioned at the affected area 2, the control unit 28 controls the power supply unit 26 to sequentially apply voltage to each electrode 18 according to the rules described below. That is, the control unit 28 controls the power supply unit 26 to apply voltage to some of the electrodes 18 multiple times in succession, and then to other electrodes 18 multiple times in succession. The "some electrodes 18" and the "other electrodes 18" may each refer to a single electrode 18 or to two or more electrodes 18. Furthermore, "applying voltage multiple times in succession" refers to applying a biphasic pulse to the same electrode 18 multiple times without applying voltage to other electrodes 18 in between. Hereinafter, the multiple consecutive voltage applications to the same electrode 18 will be referred to simply as "consecutive application." The sequential and consecutive application of voltage to each electrode 18 can be confirmed, for example, by connecting an oscilloscope to each electrode 18.

[0028] FIG. 3 shows a first example of the timing of applying voltage to each electrode 18. As an example, the control unit 28 continuously applies voltage to the first electrode 18a through the third electrode 18c provided on one spline 16 in sequence. The control unit 28 then continuously applies voltage to the first electrode 18a through the third electrode 18c provided on another spline 16 in sequence. The control unit 28 repeats this sequential application until finally applying voltage to all of the first electrodes 18a through the third electrodes 18c of the electrode assembly 12. In this embodiment, the fourth electrode 18d on each spline 16 is excluded from the targets to which voltage is applied. The fourth electrode 18d is provided for potential measurement or as a spare in case the ablation range is wide. The fourth electrode 18d may be omitted.

[0029] Specifically, first, a voltage is applied continuously multiple times to the first electrode 18a on the first spline 16a. Next, a voltage is applied continuously multiple times to the second electrode 18b on the first spline 16a. Next, a voltage is applied continuously multiple times to the third electrode 18c on the first spline 16a. Next, the voltage application target is shifted to the second spline 16b, and a voltage is applied continuously multiple times in sequence to the first electrode 18a to the third electrode 18c on the second spline 16b. Thereafter, a voltage is applied continuously multiple times in sequence to each of the electrodes 18 on the third spline 16c to the sixth spline 16f.

[0030] In this embodiment, the power supply unit 26 applies a voltage to each electrode 18 to generate a biphasic pulse (bipolar pulse). Therefore, 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 Am is, for example, 1000 V or more and 4000 V or less. The pulse width Δp is, for example, 0.1 μs or more and 100 μs or less.

[0031] In this embodiment, ablation is completed by applying voltage continuously in sequence to all of the electrodes 18 to which voltage is to be applied in the electrode assembly 12, i.e., the first electrode 18a to the third electrode 18c on the first spline 16a to the sixth spline 16f. Note that, with one cycle being defined as the application of voltage to all of the electrodes 18 to which voltage is to be applied, ablation may be completed by applying voltage multiple times. The number of consecutive voltage applications and the number of cycles may be appropriately set by a designer based on experiments, etc. For example, the number of consecutive applications is set within a range of 2 to 100. The number of consecutive applications may also vary for each electrode. The number of cycles may be, for example, 1 to 1000 cycles. Furthermore, the control unit 28 may control the power supply unit 26 to repeat the sequential application of voltage multiple times, with multiple cycles being defined as one set. The number of sets may be appropriately set by a designer based on experiments, etc., and may be, for example, 1 to 100 sets.

[0032] By sequentially applying a voltage to each electrode 18, it is possible to increase the region that can be formed by each electrode 18 compared to when a voltage is applied to all of the multiple electrodes 18 simultaneously. This is thought to be because when a voltage is applied to all of the multiple electrodes 18 at once, the current is dispersed among the multiple electrodes 18, resulting in a decrease in current density, whereas when a voltage is applied sequentially to each electrode 18, the current is concentrated in one electrode 18, resulting in an increase in current density. Furthermore, by sequentially applying a voltage to the multiple electrodes 18 at intervals, it is possible to suppress body movements of the patient caused by PFA.

[0033] Furthermore, by continuously applying a voltage to the same electrode 18, the number of times the power supply target needs to be switched can be reduced compared to when the power supply target is switched for each voltage application, which simplifies the control performed by control unit 28.

[0034] Furthermore, control unit 28 may control power supply unit 26 as follows. Fig. 4 is a diagram showing a second example of the timing of applying voltage to each electrode 18. That is, control unit 28 controls power supply unit 26 to apply voltage multiple times in succession to all of the electrodes 18 to which voltage is applied that are provided on some of the splines 16, and then to apply voltage multiple times in succession to all of the electrodes 18 to which voltage is applied that are provided on other of the splines 16. "Some of the splines 16" and "other splines 16" may each be one spline 16 or two or more splines 16.

[0035] As an example, the control unit 28 simultaneously and continuously applies a voltage to the first electrodes 18a to the third electrodes 18c provided on one spline 16. Then, the control unit 28 simultaneously and continuously applies a voltage to the first electrodes 18a to the third electrodes 18c provided on another spline 16. The control unit 28 repeats this sequential application until finally applying a voltage to all of the first electrodes 18a to the third electrodes 18c of the electrode assembly 12. In the present disclosure, "simultaneously applied" means that the states in which voltages are applied to the electrodes 18 overlap at least temporarily.

[0036] Specifically, first, a voltage is applied simultaneously and continuously multiple times to the first electrode 18a to the third electrode 18c on the first spline 16a. Next, the target to which the voltage is applied is shifted to the second spline 16b, and a voltage is applied simultaneously and continuously multiple times to the first electrode 18a to the third electrode 18c on the second spline 16b. Thereafter, the target to which the voltage is applied is shifted in order from the third spline 16c to the sixth spline 16f, and a voltage is applied simultaneously and continuously multiple times to the first electrode 18a to the third electrode 18c on each spline 16. Note that application of voltage to all splines 16 may be counted as one rotation, and ablation may be completed by applying voltage multiple times. Alternatively, multiple rotations of voltage may be counted as one set, and multiple sets of voltage application may be performed. The number of consecutive voltage applications, the number of rotations, and the number of sets are as described above.

[0037] In this way, by switching the target to which voltage is applied in spline units, it is possible to enlarge the region that can be formed by each electrode 18, as in the first example in which the target to which voltage is applied is switched in electrode units. Furthermore, compared to the first example, it is possible to further simplify control. Furthermore, it is possible to easily simplify the power supply circuit for switching the target to which voltage is applied. This allows the power supply device 8 to be made more compact. Furthermore, it is possible to easily add more electrodes 18. Furthermore, compared to the first example, it is possible to shorten the time required for ablation. Alternatively, if the time until ablation is completed is the same, it is possible to increase the number of times that voltage is applied, thereby making it possible to further enlarge the region.

[0038] The order of power supply is not limited as long as voltage is ultimately applied to all of the electrodes 18 to be powered in the electrode assembly 12. For example, after voltage is continuously applied to some of the electrodes 18 to be powered on one spline 16, the power supply may move to the electrodes 18 on the next spline 16. As one example, voltage may be continuously applied in sequence to the first electrodes 18a on each spline 16, then voltage may be continuously applied in sequence to the second electrodes 18b on each spline 16, and finally voltage may be continuously applied in sequence to the third electrodes 18c on each spline 16.

[0039] Furthermore, the order in which power is supplied to the first electrodes 18a to the third electrodes 18c on each spline 16 is not limited. The order in which power is supplied to the first electrodes 18a to the third electrodes 18c may differ for each spline 16. The order in which power is supplied to the first spline 16a to the sixth spline 16f is also not limited. Furthermore, some splines 16 may be excluded from the targets for power supply. Alternatively, the electrodes 18 may be divided into a plurality of electrode groups, the number of which is less than the number of electrodes 18, and voltage may be applied to each electrode group in sequence. The second example described above is an example of such grouping. Note that the electrodes 18 belonging to each electrode group may be arranged on different splines 16. Alternatively, the electrodes 18 on one spline 16 may belong to different electrode groups. Alternatively, the same electrode 18 may be assigned to two or more different electrode groups.

[0040] Furthermore, the shape and number of the splines 16 and the electrodes 18 are not limited. Alternatively, the catheter 4 may not have splines 16 at the tip of the shaft 10, and the electrodes 18 may be disposed on the shaft 10. Alternatively, the power supply unit 26 may apply a voltage to each electrode 18 to generate a monophasic pulse.

[0041] Furthermore, the configurations of the catheter 4 and the power supply device 8 can be modified as appropriate. For example, the distal end of the shaft 10 of the catheter 4 may be bendable 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, for example, be pre-installed in the computer, or may be installed into the computer from a network or a recording medium.

[0042] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0043] The embodiments may be specified by the following items. [1st item] a power supply unit (26) electrically connected to the catheter (4) having a plurality of electrodes (18) and applying a voltage to the plurality of electrodes (18); and a control unit (28) that controls the power supply unit (26) to apply a voltage to some of the electrodes (18) multiple times in succession, and then apply a voltage to other electrodes (18) multiple times in succession. Power supply (8). [Second item] The catheter (4) has a shaft (10) and a plurality of splines (16) arranged in a direction around the axis of the shaft (10), Each spline (16) is provided with at least one electrode (18); the control unit (28) controls the power supply unit (26) to apply voltages multiple times in succession to all of the electrodes (18) to be supplied with power and provided on some of the splines (16), and then to apply voltages multiple times in succession to all of the electrodes (18) to be supplied with power and provided on other splines (16); The power supply device (8) described in item 1. [3rd item] a catheter (4) having a plurality of electrodes (18); The power supply device (8) according to the first or second item, Ablation system (1). [Explanation of symbols]

[0044] 1 ablation system, 4 catheter, 8 power supply unit, 10 shaft, 16 spline, 18 electrode, 26 power supply unit, 28 control unit.

Claims

[Claim 1] a power supply unit electrically connected to the catheter having a plurality of electrodes and applying a voltage to the plurality of electrodes; and a control unit that controls the power supply unit to apply a voltage to some of the electrodes multiple times in succession, and then apply a voltage to other of the electrodes multiple times in succession. power supply.

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