Power supply device and ablation system

Abstract

The power supply device of one embodiment of the present application includes: a power supply portion that supplies power for performing ablation using an irreversible electroporation method to a plurality of electrodes in an ablation catheter; and a control portion that controls a pulse voltage having a plurality of positive amplitude values to be applied to three or more application electrodes including the plurality of electrodes in a manner of applying the pulse voltage to the three or more application electrodes when the ablation is performed by supplying the power.

Description

Technical Field

[0001] The present invention relates to an ablation system comprising an ablation catheter for performing ablation and a power supply device for supplying electricity for performing ablation, and a power supply device applied to such an ablation system. Background Technology

[0002] As one of the medical devices used to treat lesions (such as tumors) in a patient's body, an ablation system for ablating such lesions has been proposed. This ablation system includes an electrode catheter serving as an ablation conduit and a power supply device for supplying electricity for ablation. Furthermore, for example, Patent Document 1 discloses an ablation system that performs ablation using irreversible electroporation (IRE).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2019-500170 Summary of the Invention

[0006] Furthermore, such ablation systems generally require improved effectiveness of treatments performed via ablation. Ideally, a power supply device and ablation system should be provided that enhance the effectiveness of treatments performed via ablation.

[0007] One embodiment of the present invention provides a power supply device comprising: a power supply unit that supplies power to a plurality of electrodes in an ablation catheter for performing ablation using an irreversible electroporation method; and a control unit that, when the power is supplied for the ablation, controls the pulse voltage by applying pulse voltages having multiple positive amplitude values ​​to three or more application electrodes including the plurality of electrodes.

[0008] An ablation system according to one embodiment of the present invention includes: an ablation catheter having a plurality of electrodes; and a power supply device according to one embodiment of the present invention described above.

[0009] In a power supply device and ablation system according to one embodiment of the present invention, when performing ablation using irreversible electroporation, the pulse voltage is controlled by applying pulse voltages with multiple positive amplitude values ​​to the three or more application electrodes. In ablation using irreversible electroporation, it is generally necessary to apply very high voltages (pulse voltages) to the electrodes; however, the electric field concentration caused by such high voltages easily leads to discharges from the electrode tips. If such discharges occur at the electrode tips, thrombi may form during ablation treatment, or the ablation catheter may shift due to the impact of the discharge. By controlling the application of pulse voltages with the aforementioned multiple positive amplitude values, it is easier to suppress the electric field concentration caused by high-voltage pulse voltages and to prevent discharges from the application electrodes. Therefore, it is easier to prevent the formation of thrombi and the shifting of the ablation catheter as described above.

[0010] Alternatively, the control unit may use pulse voltages having multiple positive amplitude values ​​to control the absolute value of the amplitude difference between adjacent application electrodes among the three or more application electrodes to below a first threshold, thereby controlling the electric field strength near the adjacent application electrodes to below a predetermined electric field threshold. In this case, the electric field strength near the adjacent application electrodes is below the predetermined electric field threshold, thus making it easier to suppress the electric field concentration. Therefore, it is less likely to generate the aforementioned discharge, and thus it is easier to prevent the formation of thrombi and the displacement of the ablation catheter placement as described above. As a result, the effectiveness of the treatment performed by ablation is further improved.

[0011] In this case, the control unit may control the maximum value of the absolute difference between the amplitude values ​​of the pulse voltages between the adjacent applied electrodes to be at least a second threshold. In this case, by controlling the absolute value of the amplitude difference between the pulse voltages to be below the first threshold and ensuring that the maximum value of the absolute value of the amplitude difference is at least a minimum value (the second threshold), the result is as follows: That is, while ensuring the range of the generated electric field (ablation range), the concentration of the electric field is suppressed. As a result, the effectiveness of the treatment performed by ablation is further improved.

[0012] Alternatively, the three or more application electrodes can be configured to consist of three or more electrodes that are part of the plurality of electrodes in the ablation catheter. In this case, the application electrode to which the pulse voltage, which is the object of control during ablation, is applied is only composed of the electrodes of the ablation catheter (the three or more electrodes mentioned above), thus making it easy to control the pulse voltage. As a result, the convenience of ablation is improved. Incidentally, in addition to the electrodes of such an ablation catheter, the counter plate mentioned above can be listed as an example of the three or more application electrodes.

[0013] It should be noted that the ablation catheters mentioned above can include those used to treat arrhythmias by ablating the affected area within the patient's body. Furthermore, the ablation target can also be, for example, a tumor-bearing area within the patient's body.

[0014] According to one embodiment of the present invention, the power supply device and ablation system are configured such that, during ablation using irreversible electroporation, the pulse voltage is controlled by applying pulse voltages with multiple positive amplitude values ​​to the three or more applied electrodes. Therefore, the following results are achieved: It is easier to prevent the formation of thrombi and displacement of the ablation catheter placement position as described above. This improves the effectiveness of the treatment performed by ablation. Attached Figure Description

[0015] Figure 1 This is a block diagram schematically illustrating an example of the overall configuration of an ablation system according to one embodiment of the present invention.

[0016] Figure 2 It means Figure 1 A schematic diagram showing a detailed example of the structure of an ablation catheter.

[0017] Figure 3 It means Figure 2 A schematic diagram illustrating an example of deformation near the tip of the duct shaft.

[0018] Figure 4 It means Figure 2 A schematic diagram illustrating another example of a deformed state near the tip of the duct shaft.

[0019] Figure 5 This is a timing diagram showing a typical voltage waveform example during ablation.

[0020] Figure 6 This is a schematic diagram showing the voltage waveform during ablation in a comparative example.

[0021] Figure 7 This is a schematic diagram illustrating the voltage waveform during ablation in an embodiment.

[0022] Figure 8 It means Figure 6 , Figure 7 A graph showing an example of the magnitude relationship of various parameters. Detailed Implementation

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the description proceeds in the following order.

[0024] 1. Implementation method (example of voltage control of the four electrodes of the ablation catheter)

[0025] 2. Variations

[0026] <1. Implementation Method>

[0027] [constitute]

[0028] Figure 1 A block diagram schematically illustrates an example of the overall configuration of an ablation system 5 according to one embodiment of the present invention. For example, as... Figure 1 As shown, the ablation system 5 is used to treat a lesion 90 in the body of patient 9, and to perform prescribed ablation on such a lesion 90. It should be noted that the aforementioned lesion 90 may include, for example, lesions with arrhythmias, lesions with tumors such as cancer (liver cancer, lung cancer, breast cancer, kidney cancer, thyroid cancer, etc.).

[0029] The details will be described later, but in the ablation system 5 of this embodiment, the ablation of the affected area 90 described above is performed using irreversible electroporation (IRE) non-thermal ablation.

[0030] like Figure 1 As shown, such an ablation system 5 includes: an ablation catheter 1, a fluid supply device 2, and a power supply device 3. Furthermore, when performing ablation using this ablation system 5, for example, appropriate use... Figure 1 The counter plate 4 is shown.

[0031] (A. Ablation catheter 1)

[0032] The ablation catheter 1 is, for example, inserted into the patient 9 through a blood vessel, and is an electrode catheter used to treat the aforementioned arrhythmia, tumor, etc., by ablation of the affected area 90. The ablation catheter 1 also has an infusion mechanism that allows a prescribed infusion fluid L (e.g., physiological saline) to flow out (spray) from its tip during such ablation. In other words, the ablation system 5 is an ablation system with such an infusion mechanism. It should be noted that the fluid L is supplied to the interior of the ablation catheter 1 from the fluid supply device 2 described later, circulating (see [reference]). Figure 1 ).

[0033] Figure 2 This is a schematic diagram showing a detailed example of the structure of the ablation catheter 1. The ablation catheter 1 includes a catheter shaft 11 (catheter tube) which serves as the main body (long strip) of the catheter and a handle 12 attached to the base end of the catheter shaft 11.

[0034] (Catheter axis 11)

[0035] The conduit shaft 11 is composed of a flexible tubular structure (a hollow tubular member) and has a shape that extends along its own axial direction (Z-axis direction) (see reference). Figure 2 Specifically, the axial length of the guide shaft 11 is several to tens of times longer than the axial (Z-axis direction) length of the handle 12.

[0036] like Figure 2 As shown, the catheter shaft 11 has a tip portion (tip flexibility portion 11A) configured to provide superior flexibility. Furthermore, as... Figure 1 As shown, the specified tip-near structure 6, described later, is provided within the flexible portion 11A at the tip. The conduit shaft 11 also has a so-called multi-lumen structure, in which multiple cavities (inner holes, fine holes, through holes) are formed internally, extending along its own axial direction (Z-axis direction). Various fine wires (such as conductors 50, deflection wires, and deformation wires 60, described later) are inserted into the cavities of this conduit shaft 11 in a mutually electrically insulated manner. Furthermore, inside the conduit shaft 11, in addition to the cavities for inserting these various fine wires, cavities for allowing the aforementioned perfusion fluid L to flow are also formed and extend axially.

[0037] The outer diameter of such a conduit shaft 11 is, for example, about 0.3 to 4.0 mm, and the axial length of the conduit shaft 11 is, for example, about 300 to 1500 mm. In addition, the materials used to construct the conduit shaft 11 include, for example, thermoplastic resins such as polyamide, polyether polyamide, polyurethane, polyether block amide (PEBAX) (registered trademark), and nylon.

[0038] Here, as Figure 2 As shown, the aforementioned near-apex structure 6 includes: a branch point of the catheter shaft 11 (located on the base side of the near-apex structure 6), a confluence point located near the very tip of the catheter shaft 11 (near the tip 110 described later), and a plurality of (five in this example) branch structures 61a to 61e that individually connect these branch points and the confluence point in a curved manner. These branch structures 61a to 61e are arranged at approximately equal intervals in a plane orthogonal to the axial direction (Z-axis) of the catheter shaft 11 (in the XY plane).

[0039] In addition, such as Figure 2 As shown, in these branch structures 61a to 61e, one or more electrodes 111 (four electrodes 111 in this example) are arranged separately at predetermined intervals along their curved extension direction. Each electrode 111 is an annular electrode. On the other hand, a tip 110 is arranged at the confluence point (near the tip of the duct shaft 11) between the aforementioned branch structures 61a to 61e.

[0040] As described above, such electrodes 111 are, for example, electrodes for potential measurement or ablation, and are made of highly conductive metallic materials such as aluminum (Al), copper (Cu), SUS, gold (Au), and platinum (Pt). On the other hand, the tip 110 is made of a metallic material, for example, the same as that of each electrode 111, or a resin material such as silicone rubber or polyurethane. It should be noted that, as an example, the preferred parameters for each electrode 111 when using the above-described irreversible electroporation ablation method are as follows: Preferably, the length of each electrode 111 (electrode length along the axial direction of the conduit shaft 11) is approximately 0.3 to 5.0 mm, and the spacing between adjacent electrodes 111 along the axial direction of the conduit shaft 11 is approximately 0.3 to 5.0 mm.

[0041] The tip of each of the aforementioned wires 50 is individually electrically connected to each of the electrodes 111. Furthermore, the base of each wire 50 can be connected from inside the catheter shaft 11 via the handle 12 to the outside of the ablation catheter 1. Specifically, as... Figure 1 As shown, the base end of each wire 50 is taken out from the base end portion (connector portion) along the Z-axis in the handle 12.

[0042] It should be noted that the four electrodes 111 arranged according to each of the above-described branch structures 61a to 61e correspond to a specific example of the "three or more electrodes" and "three or more application electrodes" of the present invention.

[0043] Here, the shape of the structure 6 near the tip is configured to change (deform) according to the deformation operation of the handle 12 (the operation of the deformation operation part 123 described later). Specifically, the shape of the structure 6 near the tip is a non-expanded shape (contracted shape: see the description later) in which the structure 6 near the tip does not expand along the axial direction (Z-axis). Figure 3 ) and the unfolded shape (expanded shape: refer to) that causes the structure 6 near the top to unfold axially from the non-unfolded shape. Figure 2 and the following Figure 4 The variations between these two shapes are described in detail later. However, as an example of such a non-expanded shape (first shape), one can cite the "petal shape" (an example of the flat shape, composed of the aforementioned multiple branch structures 61a-61e) as an example. Figure 3 On the other hand, as an example of the aforementioned unfolded shape (second shape), one can cite a petal shape (each branch structure 61a-61e) unfolding axially (the so-called "basket shape": see...). Figure 2 and the following Figure 4 ).

[0044] Incidentally, the "basket shape" mentioned above refers to, for example, such as... Figure 2 , Figure 4 The shape formed by the multiple branch structures 61a to 61e shown is similar to the curved pattern formed on the surface of a basketball.

[0045] (Handle 12)

[0046] Handle 12 is the part that the operator (doctor) grasps (holds) when using ablation catheter 1. For example... Figure 2 As shown, the handle 12 has a handle body 121 attached to the base end of the guide shaft 11, a rotation operation part 122, and a deformation operation part 123.

[0047] The handle body 121 corresponds to the part that the operator actually holds (the gripping part), and has a shape that extends along its axial direction (Z-axis). The handle body 121 is made of synthetic resins such as polycarbonate and acrylonitrile-butadiene-styrene copolymer (ABS).

[0048] Details will be described later, but the rotation operating part 122 is the part operated during a deflection action that causes bidirectional deflection (flexion) near the tip of the catheter shaft 11 (tip flexible part 11A). This rotation operating part 122 is used in conjunction with a pair of deflection lines (not shown) during such a deflection action. Specifically, during such a deflection action, the operator of the ablation catheter 1 operates (rotates) the rotation operating part 122. Figure 2 As shown, such a rotating operating unit 122 is configured to include a locking mechanism 40 and a rotating plate 41.

[0049] It should be noted that the tips of each of the aforementioned pair of deflection lines are fixed to the tip side of the catheter shaft 11 (for example, near the tip 110). Furthermore, the base ends of each of these pair of deflection lines extend from inside the catheter shaft 11 into the handle 12 (inside the handle body 121).

[0050] like Figure 2 As shown, the rotating plate 41 is a component rotatably mounted to the handle body 121 with a rotation axis (Y-axis) perpendicular to its axial direction (Z-axis) as its center. This rotating plate 41 corresponds to the part that the operator actually operates during the aforementioned rotational operation, and is roughly disk-shaped. Specifically, in this example, as... Figure 2 As indicated by arrows d1a and d1b, the rotating plate 41 can be rotated bidirectionally relative to the handle body 121 in the ZX plane (rotation operation with the aforementioned rotation axis as the rotation center).

[0051] It should be noted that the locking mechanism 40 described above is a mechanism for fixing (locking) the rotational position of such a rotating plate 41 in the ZY plane.

[0052] Here, as Figure 2As shown, a pair of grips 41a and 41b are integrally disposed on the side of the rotating plate 41. In this example, as... Figure 2 As shown, with the rotation axis of the rotating plate 41 as the center, the handles 41a and 41b are positioned at points symmetrically opposite each other. These handles 41a and 41b correspond to the parts operated (pressed) by the operator using the fingers of one hand when rotating the rotating plate 41. It should be noted that such a rotating plate 41 is made of, for example, the same material (synthetic resin, etc.) as the handle body 121 described above.

[0053] Furthermore, a pair of fasteners (not shown) are provided on such a rotating plate 41. These fasteners are components (wire fasteners) used to individually fix each base end of the pair of deflection wires by means of thread fixing or the like. It should be noted that, among these fasteners, the lead-in length near each base end when fixing each base end of the pair of deflection wires can be arbitrarily adjusted.

[0054] The aforementioned deformation operation section 123 is operated by the operator during a deformation operation that changes the shape of the aforementioned tip-near structure 6 between the aforementioned non-expanded shape (petal shape) and unfolded shape (basket shape). In the deformation line 60 used during such a deformation operation, its tip side is fixed to the tip-near structure 6 (near the aforementioned tip tip 110). On the other hand, as... Figure 2 As shown, the base end of the deformation line 60 is taken out from the base end of the handle body 121 and assembled into the deformation operation part 123.

[0055] In such a transformation operation unit 123, specifically as follows: Figure 2 As indicated by arrows d3a and d3b, the operation is performed along the extension direction (Z-axis) of the deformation line 60. This involves pushing the deformation line 60 into the handle body 121 and pulling the deformation line 60 out of the handle body 121. Details will be described later, but the operation performed on the deformation operation section 123 in the direction of arrows d3a and d3b corresponds to the deformation operation used to deform the structure 6 near the tip. Furthermore, the shape of the structure 6 near the tip during the deformation operation can be set to any intermediate shape between the non-expanded shape (petal shape) and the unfolded shape (basket shape) based on the position of the deformation operation section 123 (a set position along the Z-axis).

[0056] (B. Liquid supply device 2)

[0057] The liquid supply device 2 is a device for supplying the aforementioned infusion liquid L to the ablation catheter 1, such as... Figure 1 As shown, it has a liquid supply section 21.

[0058] like Figure 1 As shown, the liquid supply unit 21 supplies the aforementioned liquid L to the ablation catheter 1 at any time according to the control signal CTL2 described later. Furthermore, the supply of liquid L is executed or stopped according to the control signal CTL2. It should be noted that such a liquid supply unit 21 may be configured to include, for example, a liquid pump and a resin tube.

[0059] (C. Power supply device 3)

[0060] like Figure 1 As shown, the power supply device 3 is a device that supplies power Pout (pulse voltage described later) for ablation using the aforementioned irreversible electroporation method between the ablation catheter 1 (electrode 111) and the counter plate 4 (described later), while simultaneously controlling the supply of liquid L in the liquid supply device 2. Figure 1 As shown, the power supply device 3 includes an input unit 31, a power supply unit 32, a control unit 33, and a display unit 34.

[0061] The input unit 31 is used to input instruction signals (operation signals Sm) for indicating various settings and prescribed actions. These operation signals Sm are input from the input unit 31 based on operations performed by the operator of the power supply unit 3 (e.g., an engineer). However, these various settings can also be set to be preset in the power supply unit 3 without being input by the operator, for example, at the time of product shipment. Furthermore, the settings input by the input unit 31 are supplied to the control unit 33, which will be described later. It should be noted that such an input unit 31 is constructed using, for example, a standard dial, button, or touch panel.

[0062] The power supply unit 32 supplies power Pout between the ablation catheter 1 (electrode 111) and the counter plate 4 (described later) according to the control signal CTL1. Further details will be described later; however, when supplying such power Pout for ablation, a high-voltage pulse voltage (voltage Vout) is applied to each electrode 111 of the ablation catheter 1. It should be noted that this power supply unit 32 is constructed using a standard power supply circuit (e.g., a switching regulator).

[0063] The control unit 33 is a component that controls the entire power supply unit 3 while performing prescribed calculations, and is configured, for example, using a microcomputer. Specifically, the control unit 33 firstly has the function of controlling the power supply operation of the power Pout in the power supply unit 32 using the control signal CTL1 (power supply control function). During the power Pout supply operation, the control unit 33 also controls the aforementioned pulse voltage (voltage Vout). Furthermore, the control unit 33 has the function of controlling the liquid L supply operation in the liquid supply device 2 (liquid supply unit 21) using the control signal CTL2 (liquid supply control function).

[0064] It also continuously supplies the control unit 33 with temperature information It (refer to) measured in the ablation catheter 1 (temperature sensors such as thermocouples configured corresponding to each electrode 111). Figure 1 Furthermore, the power supply unit 32 continuously supplies the control unit 33 with the measured value of the impedance Z between the electrode 111 of the ablation catheter 1 and the counter plate 4 (described later) (see reference). Figure 1 ).

[0065] It should be noted that the detailed operation of the pulse voltage control in the control unit 33 during the power supply operation of the aforementioned Pout will be described later. Figure 7 , Figure 8 ).

[0066] Display unit 34 is a part that displays various information and outputs it to the outside (monitor). The information to be displayed may include, for example, various setting values ​​input from input unit 31, various parameters supplied from control unit 33, and temperature information It supplied from ablation catheter 1. However, the information to be displayed is not limited to these; it may also be configured to display other information or add other information to the display. Such a display unit 34 is constructed using a display based on various methods (e.g., liquid crystal display, CRT (Cathode Ray Tube) display, organic EL (Electro Luminescence) display, etc.).

[0067] (D. Counter plate 4)

[0068] For example, such as Figure 1 As shown, the electrode 4 is used in a state of being worn on the body surface of the patient 9 during ablation. Specifically, during ablation using the aforementioned irreversible electroporation method, power (Pout) is supplied between the ablation catheter 1 (electrode 111) and the electrode 4. Furthermore, during such ablation, the aforementioned impedance Z is measured continuously, and the measured impedance Z is supplied from the power supply unit 32 to the control unit 33 in the power supply device 3 (see reference). Figure 1 ).

[0069] [Actions and their functions / effects]

[0070] (A. Basic movements)

[0071] In this ablation system 5, for example, as described above, when treating a lesion 90 with arrhythmia or a lesion 90 with a tumor such as cancer, such a lesion 90 is ablated using the aforementioned irreversible electroporation method (see [reference]). Figure 1 In such dissolution, firstly, for example, as... Figure 1 As indicated by arrow P1, the catheter shaft 11 of the ablation catheter 1 is inserted into the body of the patient 9, for example, through a blood vessel. Then, the affected area 90 is ablated by supplying power Pout (voltage Vout) from the power supply device 3 (power supply unit 32) between the electrode 111 near the tip of the ablation catheter 1 and the counter plate 4.

[0072] Furthermore, in this embodiment, during such ablation, the aforementioned perfusion fluid L is supplied to the ablation catheter 1. Specifically, for example, as... Figure 2 As shown, liquid L is supplied to the handle body 121 from the base end side (liquid inlet) of the handle body 121. Furthermore, the power supply device 3 (control unit 33) uses the aforementioned control signal CTL2 to control the supply operation of liquid L in such a liquid supply device 2. Then, for example, as... Figure 2 As shown, the liquid L flows out (sprays) from near the tip of the ablation catheter 1 (near the branch point described above in the near-tip structure 6). By spraying such liquid L, blood retention during ablation is reduced, thus preventing thrombus adhesion to the treatment area.

[0073] (A-1. Deflection of the tip flexible part 11A by rotation operation)

[0074] Here, in the ablation catheter 1, the shape near the tip of the catheter shaft 11 (tip flexible portion 11A) changes bidirectionally according to the rotation operation of the rotating plate 41 performed by the operator. That is, during the ablation of the affected area 90 as described above, the tip flexible portion 11A is bidirectionally deflected according to such rotation operation (the aforementioned bidirectional deflection operation).

[0075] Specifically, for example, when an operator grasps the handle 12 (handle body 121) with one hand and operates the pinch handle 41a with the fingers of that hand, the rotating plate 41 is moved towards... Figure 2 When rotating in the direction of arrow d1a (right-hand rotation), the result is as follows. That is, within the catheter shaft 11, one of the aforementioned pair of deflection lines is stretched towards the base end. As a result, the flexible portion 11A at the tip of the catheter shaft 11... Figure 2 The direction indicated by arrow d2a is bent (flexed).

[0076] Furthermore, for example, when the operator operates the hand 41b to rotate the plate 41 towards... Figure 2 When the direction of arrow d1b (left-handed) is rotated, the result is as follows. That is, within the catheter shaft 11, the other of the pair of deflection lines is stretched towards the base end. As a result, the flexible portion 11A at the tip of the catheter shaft 11... Figure 2 The arrow d2b in the image indicates the direction of the bend.

[0077] Thus, the bidirectional (head-shaking) deflection of the catheter shaft 11 is achieved by the operator rotating the rotating plate 41. It should be noted that by rotating the handle body 121 around an axis (in the XY plane), for example, the state of the catheter shaft 11 inserted into the patient's body can be kept unchanged, and the bending direction (deflection direction) of the flexible portion 11A at the tip of the catheter shaft 11 can be freely set. Therefore, the ablation catheter 1 is provided with a deflection mechanism for bidirectional deflection of the flexible portion 11A at the tip, allowing it to be inserted into the patient's body while changing the shape of the area near the tip of the catheter shaft 11 (the flexible portion 11A at the tip).

[0078] (A-2. Deformation of structure 6 near the top via deformation operation)

[0079] Next, besides Figure 2 Other than that, refer to Figure 3 , Figure 4 The deformation action of the structure 6 near the tip of the guide shaft 11, which is performed by the deformation operation of the deformation operation unit 123 described above, will be explained.

[0080] Figure 3 ( Figure 3 (A) Figure 3 (B) is a diagram schematically illustrating an example of the deformed state near the tip of the duct shaft 11 (the aforementioned petal-shaped state, as an example of the aforementioned non-unfurled shape). Furthermore, Figure 4 ( Figure 4 (A) Figure 4 Figure (B) is a schematic diagram illustrating an example of another deformation state (the aforementioned basket shape, as an example of the aforementioned unfolded shape) near the tip of the conduit shaft 11 (tip near structure 6). It should be noted that... Figure 4 The unfolded shape shown (basket shape) is just one example; for instance, it could also be from... Figure 4 The shape shown is slightly withered (deformed), etc.

[0081] First, for example, such as Figure 2As indicated by arrow d3a, when the deformation line 60 is pulled out of the handle body 121 by the deformation operation of the deformation operation unit 123 performed by the operator, the result is as follows. That is, as described above, the base end of the deformation line 60 is fitted to the deformation operation unit 123, therefore, in this case, for example, as... Figure 3 (A) Figure 3 As indicated by arrow d4a in (B), the deformation line 60 is stretched towards the base end during the aforementioned pull-out operation. Thus, as described above, the tip side of the deformation line 60 is fixed to the structure 6 near the tip (near the tip tip 110), therefore, for example, as... Figure 3 (A) Figure 3 As shown in (B), by stretching the tip 110 towards the base, each branch structure 61a-61e becomes a shape that contracts towards the base. That is, the structure 6 near the tip becomes the aforementioned non-expanded shape (in this example, a shape that is approximately flattened in the XY plane). Specifically, in this example, as... Figure 3 As shown in (A), the shape of the structure 6 near the top becomes the petal shape described above, which is composed of the branch structures 61a to 61e.

[0082] On the other hand, for example, such as Figure 2 As indicated by arrow d3b, when the deformation line 60 is pushed into the handle body 121 by the deformation operation of the deformation operation section 123 performed by the operator, the result is as follows. That is, in this case, for example, as... Figure 4 (A) Figure 4 As indicated by arrow d4b in (B), with the aforementioned pushing operation, the deforming line 60 is pushed out towards the top. Thus, for example, as... Figure 4 (A) Figure 4 As shown in (B), the branch structures 61a to 61e are extended towards the tip by the tip 110, forming a shape that expands towards the tip. That is, the structure 6 near the tip forms the aforementioned expanded shape (a shape that expands towards the tip along the Z-axis). Specifically, in this example, as... Figure 4 As shown in (A), the shape of the structure 6 near the top becomes the aforementioned basket shape composed of the branch structures 61a to 61e.

[0083] Thus, the deformation of the structure 6 near the top end is performed according to the deformation operation of the deformation operation unit 123.

[0084] (B. Ablation using irreversible electroporation)

[0085] Here, we will explain in detail the ablation using the aforementioned irreversible electroporation (IRE) method.

[0086] First, as mentioned above, irreversible electroporation is a non-thermal ablation method that can suppress damage to surrounding blood vessels and nerves, and therefore has attracted attention. Specifically, in existing common ablation methods such as RFA (Radiofrequency Ablation) and cryoablation, which utilize thermal energy, complications such as phrenic nerve paralysis and esophageal fistula may occur. In contrast, irreversible electroporation ablation, which uses PFA (Pulsed Electric Field Ablation), utilizes non-thermal energy and therefore does not have the potential to cause these complications.

[0087] In detail, when using such irreversible electroporation ablation, the myocardium (electric field strength threshold: approximately 400 V / cm) is generally the first to be affected by the ablation. However, the electric field strength during ablation is typically set to a value (e.g., approximately 1000–1500 V / cm) that will not affect the esophagus (electric field strength threshold: approximately 1750 V / cm) or the diaphragmatic nerves (electric field strength threshold: approximately 3800 V / cm). Therefore, as mentioned above, complications such as phrenic nerve paralysis and esophageal fistula are not caused.

[0088] Figure 5 This is a diagram illustrating a typical voltage waveform during ablation, presented using a timing diagram. Specifically, they are: Figure 5 (A) represents a typical waveform example of the voltage Vout applied to the electrodes of the ablation catheter during the aforementioned RFA. Figure 5 (B) represents a typical waveform example of the voltage Vout applied to the electrodes of the ablation catheter during irreversible electroporation ablation (PFA as described above). It should be noted that in these... Figure 5 (A) Figure 5 In (B), the horizontal axis represents time t, and the vertical axis represents voltage (the potential difference with the reference potential shown in the figure).

[0089] First of all, Figure 5 In the example of the RFA shown in (A), the voltage Vout is a high-frequency voltage (frequency = 500 kHz, period ΔT = approximately 2 μs), and the amplitude Am of the voltage Vout is approximately 70 V. Incidentally, the power supplied during this RFA is, for example, approximately 25 W. Furthermore, in the case of this RFA, for example, as... Figure 5 As shown in (A), the continuous wavelength time (e.g., on the order of tens of seconds, around 30 to 60 [s]) constitutes a high frequency, therefore, this RFA is a thermal ablation method.

[0090] On the other hand, Figure 5In the example of PFA shown in (B), the voltage Vout becomes a high-voltage (amplitude Am = 1500 [V]) and short-duration (pulse amplitude Δtp = 100 [μs]) pulse voltage. That is, in the case of this PFA, it becomes such a short-duration (μs level as described above) pulse waveform; therefore, this PFA differs from the aforementioned RFA and is a non-thermal ablation method. Furthermore, in ablation using irreversible electroporation, electroporation is generated by applying such a high-voltage and short-duration pulse voltage to the electrodes. Specifically, nanoscale pores are created in the cells of the ablated object using such a pulse voltage, thereby inducing apoptosis (cell suicide) in the poreped cells, thus causing cell extinction.

[0091] (C. Control action of pulse voltage)

[0092] Next, refer to Figures 6-8 While comparing with the comparative example, the control operation of the voltage Vout (the pulse voltage mentioned above) in the control unit 33 during ablation using the above-described irreversible electroporation method will be explained in detail.

[0093] Figure 6 This is a schematic diagram illustrating the voltage waveform during ablation in a comparative example. Figure 7 This is a diagram schematically illustrating an example of the voltage waveform during ablation in an embodiment of this invention. Furthermore, Figure 8 It means Figure 6 , Figure 7 A graph showing an example of the magnitude relationship of various parameters (amplitude difference ΔV and thresholds ΔVth1 and ΔVth2, described later).

[0094] Specifically, in Figure 6 (E) Figure 7 In (E), examples of equipotential surfaces Se of the electric field generated by the application of a voltage Vout (pulse voltage) are schematically shown near the four electrodes 111 (applied electrodes: for convenience, referred to as electrodes 111a to 111d) arranged according to each of the above-described branch structures 61a to 61e. Furthermore, in Figure 6 (A) Figure 6 (D) and Figure 7 (A) Figure 7 In (D), examples of timing waveforms of each voltage Vout (pulse voltages VoutA to VoutD) applied individually to these electrodes 111a to 111d are schematically shown. It should be noted that in these... Figure 6 (A) Figure 6 (D) and Figure 7Among the pulse voltages VoutA to VoutD shown in (A) to (D), the pulse voltages are in phase with each other (refer to pulse widths Δtp1, Δtp2, Δtp3). Furthermore, in these... Figure 6 (A) Figure 6 (D) and Figure 7 In (A) to (D), respectively, the horizontal axis represents time t, and the vertical axis represents voltage (the potential difference with the aforementioned reference potential).

[0095] (C-1. Comparative Example)

[0096] First of all, Figure 6 In the comparative example shown, during the pulse widths Δtp1 and Δtp3, the pulse voltages VoutA and VoutB have an amplitude value of Am101 = 1250 [V], while the pulse voltages VoutC and VoutD have an amplitude value of 0 [V]. On the other hand, during the pulse width Δtp2, conversely, the pulse voltages VoutA and VoutB have an amplitude value of 0 [V], while the pulse voltages VoutC and VoutD have an amplitude value of Am101 = 1250 [V]. That is, in this comparative example, pulse voltages VoutA to VoutD with a positive (>0) amplitude value of Am101 (=1250 [V]) are individually applied to the four electrodes (electrodes 111a to 111d).

[0097] Thus, in ablation using irreversible electroporation, as described above, a very high voltage is applied to each electrode 111 (electrodes 111a to 111d). Figure 6 In the comparative example shown, the amplitude value Am101 = 1250 [V] is used. However, there is a situation where electric field concentration caused by such high voltage can easily lead to discharge from the end of electrode 111.

[0098] Specifically, in Figure 6 In the comparative example shown, the absolute value of the amplitude difference ΔV between the pulse voltages VoutB and VoutC between adjacent electrodes 111b and 111c of the four electrodes 111a to 111d (amplitude difference ΔV(BC) = Am101) is very large. Details are as follows... Figure 6 As shown, the amplitude difference ΔV(BC) = Am101 is greater than the specified threshold ΔVth1 (ΔV(BC) > ΔVth1). This may lead to the following situations: Figure 6 As indicated by reference numeral Pe in the attached figure, a discharge is generated at the inner end between these electrodes 111b and 111c due to the electric field concentration caused by such a very large amplitude difference ΔV (as a region of electric field strength E that is larger than the specified electric field threshold Eth).

[0099] Furthermore, if such a discharge is generated at the tip of electrode 111, thrombosis may occur during ablation treatment, or the placement position of ablation catheter 1 (the placement position in patient 9) may shift due to the impact of the discharge. As a result, the effectiveness of ablation treatment is reduced in this comparative example.

[0100] (C-2. Examples of this implementation)

[0101] In response, Figure 7 In the embodiment shown, during the pulse widths Δtp1 and Δtp3, the amplitude values ​​of the pulse voltages VoutA, Am1, and VoutB are 1500 V, Am2, and 250 V, respectively, while VoutC has an amplitude value of 250 V and VoutD has an amplitude value of 0 V. Conversely, during the pulse width Δtp2, the amplitude values ​​are 0 VoutA, 250 VoutB, 1250 VoutC, and 1500 V, respectively. That is, in this embodiment, unlike the comparative example described above, pulse voltages VoutA to VoutD with multiple positive amplitude values ​​(three positive amplitude values ​​Am1, Am2, and Am3 in this example) are applied individually to the four application electrodes (electrodes 111a to 111d).

[0102] In this embodiment, the control unit 33 uses pulse voltages with these various positive amplitude values ​​to perform the control as shown below. That is, the control unit 33 controls the electric field strength E near these adjacent electrodes 111 to be below the electric field threshold Eth by controlling the absolute value of the amplitude difference ΔV between the pulse voltages of adjacent electrodes 111 among the four electrodes 111a to 111d to be below the aforementioned threshold ΔVth1.

[0103] Specifically, in Figure 7 In the illustrated embodiment, unlike the comparative example described above, the absolute value of the amplitude difference ΔV between the pulse voltages VoutB and VoutC between adjacent electrodes 111b and 111c, denoted as ΔV(BC) = |Am2 - Am3| (=1000[V]), is controlled to be below the threshold ΔVth1 (ΔV(BC) ≤ ΔVth1). It should be noted that in this embodiment, the absolute value of the amplitude difference ΔV between the pulse voltages VoutA and VoutB between adjacent electrodes 111a and 111b (=250[V]) and the absolute value of the amplitude difference ΔV between the pulse voltages VoutC and VoutD between adjacent electrodes 111c and 111d (=250[V]) are also controlled to be below the threshold ΔVth1.

[0104] The details of controlling such pulsed voltages VoutA to VoutD will be described later. However, in this embodiment, compared to the comparative example described above, it is easier to suppress the electric field concentration caused by the high-voltage pulsed voltage. Specifically, as... Figure 7 As shown, for example, unlike the comparative example above, the electric field strength E near the ends of adjacent electrodes 111b and 111c is below the electric field threshold Eth (E≤Eth).

[0105] In addition, for example, such as Figure 8 As shown, the range of the absolute value of the amplitude difference ΔV can also be set as follows. That is, firstly, the absolute value of the amplitude difference ΔV can be set to a range below the threshold ΔVth1, as described above. Figure 8 The range R1 shown is: ΔV ≤ ΔVth1). Furthermore, the control unit 33 can also control the maximum value of the absolute value of the pulse voltage amplitude difference ΔV between such adjacent electrodes 111 to be above the threshold ΔVth2 (see reference). Figure 8 The range shown is R2). It should be noted that, for convenience, this... Figure 8 The range R2 shown is ΔVth2≤ΔV≤ΔVth1), however, as mentioned above, the control object above the threshold ΔVth2 is preferably set to the maximum value among the absolute values ​​of the amplitude difference ΔV, compared to the absolute value of the amplitude difference ΔV itself.

[0106] It should be noted that these thresholds ΔVth1 and ΔVth2 correspond to specific examples of the "first threshold" and "second threshold" of the present invention, respectively. Furthermore, as specific examples of threshold ΔVth1, ΔVth1 = approximately 1100 to 1500 [V] can be listed, and preferably, ΔVth1 = approximately 1300 [V]. Furthermore, as specific examples of threshold ΔVth2, ΔVth2 = approximately 500 to 900 [V] can be listed, and preferably, ΔVth2 = approximately 700 [V].

[0107] (D. Function / Effect)

[0108] Thus, in the ablation system 5 of this embodiment, for example, the following effects and functions are achieved.

[0109] First, in this embodiment, when performing ablation using irreversible electroporation, the voltage Vout (pulse voltage) is controlled by applying pulse voltages (e.g., pulse voltages VoutA to VoutD) with multiple positive amplitude values ​​(e.g., three positive amplitude values ​​Am1 to Am3) to the three or more application electrodes (electrode 111). By controlling the ablation by applying pulse voltages with such multiple positive amplitude values, as described above, it is easy to suppress electric field concentration caused by high-voltage pulse voltages and to prevent discharge from the ends of the application electrodes. As a result, when using irreversible electroporation ablation, it is easier to prevent the formation of thrombi and displacement of the ablation catheter 1 as described above. Therefore, in this embodiment, the effectiveness of treatment using irreversible electroporation ablation can be improved.

[0110] Furthermore, in this embodiment, by using pulse voltages with the aforementioned multiple positive amplitude values ​​to control the absolute value of the amplitude difference ΔV between the adjacent applied electrodes to be below a threshold ΔVth1, the electric field strength E near such adjacent applied electrodes is controlled to be below a predetermined electric field threshold Eth. Thus, with the electric field strength E near the adjacent applied electrodes below the predetermined electric field threshold, it is easier to suppress the aforementioned electric field concentration. Therefore, it is less likely to generate the aforementioned discharge, and thus it is easier to prevent the formation of thrombi and the displacement of the ablation catheter 1's placement position as described above. As a result, the effectiveness of treatment performed using irreversible electroporation ablation can be further improved.

[0111] Furthermore, in this embodiment, when the maximum value of the absolute value of the pulse voltage amplitude difference ΔV is controlled to be above or above the threshold ΔVth2, the result is as follows: That is, while controlling the absolute value of such pulse voltage amplitude difference ΔV to be below or below the threshold ΔVth1, and ensuring that the maximum value of such amplitude difference ΔV is above or above the minimum value (threshold ΔVth2), as described above, the range of the generated electric field (ablation range) is ensured while the above-mentioned electric field concentration is suppressed. As a result, the effectiveness of treatment performed using irreversible electroporation ablation can be further improved.

[0112] In addition, in this embodiment, it is assumed that all three or more application electrodes are composed of electrodes 111 (three or more electrodes 111) of the ablation catheter 1. Therefore, the result is as follows: that is, the application electrode for applying the pulse voltage, which is the target of control during ablation, is composed only of electrodes 111 of the ablation catheter 1. Therefore, such pulse voltage control can be easily performed. As a result, the convenience of ablation using irreversible electroporation is improved.

[0113] <2. Variations>

[0114] The present invention has been described above with examples of embodiments, but the present invention is not limited to these embodiments and can be modified in various ways.

[0115] For example, the materials of the components described in the above embodiments are not limited, and other materials may be used. Furthermore, while the structure of the ablation catheter 1 has been specifically listed and described in the above embodiments, it is not necessary to have all the components; other components may also be included. Specifically, for example, a leaf spring capable of deforming in the flexural direction may be provided inside the catheter shaft 11 as a swaying component.

[0116] Furthermore, while the above embodiments have specifically described the configuration of the handle 12 (handle body 121 and rotation operation part 122), it is not necessary to have all of these components; other components may also be included. Specifically, for example, the configuration of the deformable operation part 123 is not limited to the configuration described in the above embodiments and may also be other configurations.

[0117] Furthermore, the shape near the tip of the catheter shaft 11 is not limited to the design described in the above embodiments. Specifically, in the above embodiments, an ablation catheter of the type where the shape near the tip of the catheter shaft 11 changes bidirectionally according to the operation of the rotating plate 41 (bidirectional type) was used as an example, but it is not limited to this. That is, for example, it could also be an ablation catheter of the type where the shape near the tip of the catheter shaft 11 changes unidirectionally according to the operation of the rotating plate 41 (unidirectional type). In this case, only one (one) of the above-described operating line is provided. In addition, it could also be an ablation catheter of the type where the shape near the tip of the catheter shaft 11 is fixed. In this case, the above-described operating line, rotating plate 41, etc. are not required.

[0118] Furthermore, the arrangement, shape, and number (one or more) of the electrodes 111 near the tip of the conduit shaft 11 (within the tip-near structure 6) are not limited to the cases listed in the above embodiments. Moreover, the shape of the tip-near structure 6 is not limited to the shapes described in the above embodiments (the flat shape (petal shape), the non-flat shape (basket shape), etc.), and may be other shapes. In addition, the configuration of the tip-near structure 6 itself (the branching point, confluence point, arrangement, shape, and number of multiple branching structures, etc.) is not limited to the configuration described in the above embodiments, and may be other configurations.

[0119] In addition, the values, ranges, and magnitude relationships of the various parameters described in the above embodiments are not limited to those described in the above embodiments, and may also be other values, ranges, and magnitude relationships.

[0120] Furthermore, while the block structures of the liquid supply device 2 and the power supply device 3 have been specifically described in the above embodiments, it is not necessary to have all the blocks described in the above embodiments; other blocks may also be included. Moreover, the entire ablation system 5 may include other devices besides those described in the above embodiments.

[0121] Furthermore, in the above embodiments, the control operations (ablation processing operations using the aforementioned pulse voltage control, etc.) in the control unit 33, which includes power supply control function and liquid supply control function, have been specifically described. However, the control methods (ablation methods using pulse voltage control, etc.) in these power supply control functions and liquid supply control functions are not limited to the methods listed in the above embodiments. Specifically, in the above embodiments, a method for controlling the pulse voltage by applying a pulse voltage having multiple positive amplitude values ​​has been specifically described, but it is not limited to the method described in the above embodiments; other methods may also be used to control the pulse voltage. In addition, as described in the embodiments, it is also possible to use other control methods instead of controlling the absolute value of the pulse voltage amplitude difference ΔV to be below the threshold ΔVth1 or above the threshold ΔVth2.

[0122] In addition, the above embodiments describe a case where the three or more electrodes for applying pulse voltages are all composed of electrodes 111 of the ablation catheter 1, but this is not an exclusive case. For example, it is also possible to configure the three or more electrodes for applying pulse voltages together with the electrodes 111 of such an ablation catheter, including other electrodes (e.g., the counter plate 4 described above). Furthermore, the above embodiments, etc., illustrate the case where power Pout for performing irreversible electroporation ablation is supplied between the multiple electrodes 111 and the counter plate 4 in the ablation catheter 1, but this is not an exclusive case. That is, as a method for supplying such power Pout to the multiple electrodes 111, for example, it is also possible to supply such power Pout between the multiple electrodes 111 without using the counter plate 4.

[0123] Furthermore, the series of processes described in the above embodiments can be performed by hardware (circuit) or by software (program). If performed by software, the software consists of a group of programs for executing each function via a computer. These programs can be pre-installed on the computer for use, or installed on the computer from a network or recording medium.

[0124] Furthermore, in the above embodiments, the example given is an ablation catheter 1 that sprays the infusion liquid L (with an infusion mechanism) to the outside, but it is not limited to this example. For example, the present invention can also be applied to an ablation catheter that does not have such an infusion mechanism.

[0125] Furthermore, in the above embodiments, examples were given of ablation targets such as the affected area 90 of the patient 9 with arrhythmia or the affected area 90 of a tumor, but the invention is not limited to these examples. That is, the ablation system of the present invention can also be applied to other parts of the patient 9's body (organs, body tissues, etc.) for ablation.

[0126] Furthermore, the various examples described so far can be applied in any combination.

Claims

1. A power supply device, comprising: The power supply unit provides electricity to multiple electrodes in the ablation catheter for performing ablation using irreversible electroporation; and The control unit, when supplying power to perform the ablation, controls the pulse voltage by applying pulse voltages with multiple positive amplitude values ​​to three or more application electrodes, including the plurality of electrodes. The control unit utilizes the pulse voltage having the aforementioned multiple positive amplitude values. The absolute value of the pulse voltage amplitude difference between adjacent application electrodes among the three or more application electrodes is controlled to be below a first threshold. Therefore, the electric field strength near the adjacent applied electrode is controlled to be below a specified electric field threshold.

2. The power supply device according to claim 1, wherein, The control unit controls the maximum value of the absolute value of the difference in amplitude of the pulse voltage between the adjacent applied electrodes to be above a second threshold.

3. The power supply device according to claim 1 or 2, wherein, The three or more application electrodes are each composed of three or more electrodes that are part of the plurality of electrodes in the ablation catheter.

4. The power supply device according to claim 1 or 2, wherein, The ablation catheter is used to treat arrhythmias by ablating the affected area in the patient's body.

5. An ablation system, comprising: The ablation catheter has multiple electrodes and a power supply device. The power supply device has: The power supply unit supplies power to the plurality of electrodes in the ablation catheter for performing ablation using irreversible electroporation; and The control unit, when supplying power to perform the ablation, controls the pulse voltage by applying pulse voltages with multiple positive amplitude values ​​to three or more application electrodes, including the plurality of electrodes. The control unit utilizes the pulse voltage having the aforementioned multiple positive amplitude values. The absolute value of the pulse voltage amplitude difference between adjacent application electrodes among the three or more application electrodes is controlled to be below a first threshold. Therefore, the electric field strength near the adjacent applied electrode is controlled to be below a specified electric field threshold.

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