Shock wave balloon catheter device

Abstract

The embodiment of the invention provides a shock wave balloon catheter device. The shock wave balloon catheter device comprises a balloon, a catheter and an electrode assembly. The balloon surrounds the periphery of the catheter; an electrode inner cavity is formed in the catheter; the electrode inner cavity is positioned in the catheter on one side of the near end of the balloon; the electrode assembly comprises a slender electrode supporting piece and a discharge electrode arranged at the far end of the electrode supporting piece; when the balloon is in an unfolded state, the far end of the electrode supporting piece and the discharge electrode are arranged in the balloon, and the far end of the electrode supporting piece extends towards the radial side wall of the balloon; when voltage is applied between the discharge electrodes, the discharge electrodes are configured to emit discharge shock waves in the liquid in the balloon; a part of circumferential arc section balloon area wall close to the discharge electrode can be adjusted to be attached to the vascular calcification lesion position, so that the vascular calcification lesion position obtains larger shock wave energy; the shock wave energy applied to a non-treatment area is reduced; when the balloon is in a folded state, the electrode supporting piece and the discharge electrode are arranged in the electrode inner cavity.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a shock wave balloon catheter device. Background Art

[0002] As heart disease patients age and the disease progresses, plaques in peripheral blood vessels and coronary arteries gradually calcify. This bone-like structure analogue causes vascular stenosis, reduces vascular blood flow, and may eventually lead to complete vascular occlusion. A shock wave balloon catheter device is provided for vascular calcification lesions; during treatment, the balloon on the catheter is pushed into the vascular calcification area; the balloon is then inflated and pressurized with liquid to make it contact with the inner wall of the blood vessel; a high-voltage pulse is applied to the electrode pair in the balloon, causing the electrode pair to discharge and generate shock waves in the liquid, which are then transmitted to the inner wall of the blood vessel to rupture the calcified plaque.

[0003] In some cases, in the circumferential direction of the blood vessel, only some arc segments may have calcified lesions, which are the treatment areas that require shock wave therapy; the remaining arc segments have no calcified or slightly calcified lesions and are non-treatment areas. However, in existing shock wave balloon catheter devices, the shock waves are basically uniformly propagated radially to the inner wall of the contacting blood vessels, applying shock wave energy to the treatment area and the non-treatment area. The shock wave energy applied to the non-treatment area may cause damage to the inner wall of the blood vessel in the non-treatment area.

[0004] For example, the blood vessel between the left ventricle and the aorta has an aortic valve, which is composed of three leaflets. The accumulation of calcium deposits on the leaflets will cause the leaflets to harden significantly and impair their ability to open and close effectively, leading to aortic valve stenosis and obstructing blood flow. The shock wave balloon catheter device can be used to break up the calcium deposits on the leaflets. However, in some cases, there may be only one or two leaflets with calcium deposits, which are therapeutic leaflets that require shock wave therapy; leaflets with no calcification deposits or slight calcification deposits are non-therapeutic leaflets that do not require shock wave therapy; and existing shock wave balloon catheter devices can only apply shock waves to the three leaflets basically evenly, and shock waves applied to leaflets with no calcification deposits or slight calcification deposits may also cause damage to them. Summary of the invention

[0005] The embodiments of the present application provide a shock wave balloon catheter device, which can enhance the shock wave energy applied to the treatment area where calcified lesions exist in the circumferential direction of the blood vessel; and at the same time, can reduce the shock wave energy applied to the non-treatment area in the circumferential direction of the blood vessel.

[0006] In one embodiment of the present application, a shock wave balloon catheter device is provided, comprising:

[0007] A balloon; the balloon has a folded state and an unfolded state; the balloon can be filled with liquid;

[0008] The balloon surrounds the outer circumference of the catheter; an electrode lumen is provided in the catheter; the electrode lumen is located in the catheter on the proximal side of the balloon;

[0009] An electrode assembly; the electrode assembly comprises

[0010] An elongated electrode support; when the balloon is in an expanded state, the distal end of the electrode support is placed in the balloon, and the distal end of the electrode support extends toward the radial side wall of the balloon;

[0011] Discharge electrode; the discharge electrode is arranged at the distal end of the electrode support;

[0012] When the balloon is in the expanded state, the discharge electrode is placed in the balloon following the distal end of the electrode support; at the same time, because the distal end of the electrode support extends toward the radial side wall of the balloon, the discharge electrode is not located at the balloon axis, but is close to a portion of the circumferential arc segment balloon area and away from the remaining portion of the circumferential arc segment balloon area; when a voltage is applied between the discharge electrodes, the discharge electrode is configured to emit a discharge shock wave in the liquid in the balloon; when the balloon is delivered to the lesion location, it can be adjusted so that the wall of the portion of the circumferential arc segment balloon area close to the discharge electrode is placed at the location of the vascular calcification lesion, and the wall of the remaining portion of the circumferential arc segment balloon area away from the discharge electrode is placed at the location of the blood vessel without calcification lesions. This allows the treatment area with calcified lesions in the circumferential direction of the blood vessel to obtain greater shock wave energy; at the same time, it reduces the shock wave energy applied to the non-treatment area in the circumferential direction of the blood vessel;

[0013] When the balloon moves in the blood vessel, in order to improve the passability, it is generally in a folded state to reduce the cross-sectional area; when the distal end of the electrode support is placed in the balloon, since the distal end of the electrode support extends toward the radial side wall of the balloon, the balloon cannot be completely folded, thereby increasing the cross-sectional area of ​​the balloon when moving in the blood vessel; for this reason, the electrode support of this embodiment is movable, and when the balloon is in a folded state, the electrode support and the discharge electrode are placed in the electrode lumen outside the balloon. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 A schematic diagram of the structure of a shock wave balloon catheter device provided in one embodiment of the present application;

[0016] Figure 2 A schematic diagram of the structure of an electrode assembly provided in one embodiment of the present application;

[0017] Figure 3 A cross-sectional view of a catheter provided for one embodiment of the present application;

[0018] Figure 4 This is a schematic diagram of the structure of a balloon located at a heart valve in one embodiment of the present application;

[0019] Figure 5 A schematic diagram of the structure of an electrode assembly provided in another embodiment of the present application;

[0020] Figure 6 Schematic diagram of the structure of the heart valve. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that these implementation methods are only used to illustrate the present invention and are not used to limit the scope. After reading the present invention, modifications of various equivalent forms of the present invention by those skilled in the art all fall within the scope defined by the present application.

[0022] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element in the middle. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an element in the middle. The "proximal end" in this application refers to the side close to the operator, and the "distal end" refers to the side away from the operator.

[0023] The following will be combined Figures 1 to 6 The shock wave balloon catheter device of the embodiment of this specification is explained and described. It should be noted that in the embodiment of the present invention, the same reference numerals represent the same components. For the sake of brevity, the detailed description of the same components is omitted in different embodiments, and the descriptions of the same components can be referenced and quoted to each other.

[0024] As heart disease patients age and the disease progresses, plaques in peripheral blood vessels and coronary arteries gradually calcify. This bone-like structure can cause narrowing of the vessels, reduce blood flow in the vessels, and may eventually lead to complete occlusion of the vessels.

[0025] The indications of the shock wave balloon catheter device include interventional treatment of vascular calcification lesions. The shock wave balloon catheter device includes a catheter, a balloon sealed around the outer circumference of the catheter, and at least one electrode pair arranged in the balloon; the balloon can be filled with liquid; each of the electrode pairs includes a first electrode and a second electrode; when a voltage is applied between the first electrode and the second electrode, a plasma arc is formed in the liquid in the balloon between the first electrode and the second electrode, thereby generating bubbles in the liquid, which expand and collapse, and then forming a mechanical shock wave in the balloon, which is mechanically transmitted through the liquid and the balloon to apply mechanical force or pressure to split any calcified plaque on or in the wall of the vascular system.

[0026] When the device is in clinical use, the balloon on the catheter is pushed into the vascular calcification area, and the balloon is pressurized to ensure close contact with the blood vessel wall; then a voltage is applied between the first electrode and the second electrode, and a shock wave is formed in the liquid in the balloon between the first electrode and the second electrode. The shock wave impacts and destroys the calcified lesions of the blood vessel, causing the calcification of the intima and the media to break. The modification effect of the calcified lesions can be judged by evaluating the symmetrical expansion of the balloon.

[0027] The shock wave balloon catheter device efficiently and safely destroys superficial and deep calcifications, thereby significantly improving vascular compliance. The device is effective not only for superficial and deep calcifications, but also for eccentric and non-eccentric lesions, reducing the risk of complications such as dissection and perforation.

[0028] In some cases, in the circumferential direction of the blood vessel, only some arc segments may have calcified lesions, which are the treatment areas that require shock wave therapy; the remaining arc segments have no calcified or slightly calcified lesions and are non-treatment areas. However, in existing shock wave balloon catheter devices, the shock waves are basically uniformly propagated radially to the inner wall of the contacting blood vessels, applying shock wave energy to the treatment area and the non-treatment area. The shock wave energy applied to the non-treatment area may cause damage to the inner wall of the blood vessel in the non-treatment area.

[0029] The blood vessel between the left ventricle and the aorta has the aortic valve, such as Figure 6As shown, the aortic valve inhibits the blood flow injected into the aorta from flowing back into the left ventricle. The aortic valve is composed of three leaflets 4. The accumulation of calcium deposits 401 on the leaflets 4 will cause aortic valve stenosis and hinder blood flow. The shock wave balloon catheter device can be used to break up the calcium deposits 401 on the leaflets 4; and compared with the calcified plaques in other vascular parts, the calcified tissue of the aortic valve requires greater shock wave energy to complete the treatment. However, there may be only one or two leaflets 4 with calcium deposits 401, which are the treatment leaflets that require shock wave treatment; for leaflets 4 with no calcification deposits or slight calcification deposits, they are non-treatment leaflets that do not require shock wave treatment; and the existing shock wave balloon catheter device can only apply shock waves to the three leaflets 4 basically evenly, and the shock waves applied to the leaflets 4 with no calcification deposits or slight calcification deposits may also cause damage to them.

[0030] To solve the above technical problems, an embodiment of the present application provides a shock wave balloon catheter device, such as Figure 1 Shown, including

[0031] Balloon 1; the balloon 1 has a folded state and an unfolded state; the balloon 1 can be filled with liquid;

[0032] The catheter 2; the balloon 1 surrounds the outer periphery of the catheter 2; an electrode lumen is provided in the catheter 2; the electrode lumen is located in the catheter 2 on the proximal side of the balloon 1;

[0033] An electrode assembly; the electrode assembly comprises

[0034] An elongated electrode support 301; when the balloon 1 is in an expanded state, the distal end of the electrode support 301 is placed in the balloon 1, and the distal end of the electrode support 301 extends toward the radial side wall of the balloon 1;

[0035] Discharge electrode 302; the discharge electrode 302 is arranged at the distal end of the electrode support 301;

[0036] When the balloon 1 is in the expanded state, the discharge electrode 302 is placed in the balloon 1 following the distal end of the electrode support 301; at the same time, because the distal end of the electrode support 301 extends toward the radial side wall of the balloon 1, the discharge electrode 302 is not located at the axis of the balloon 1, but is close to a part of the circumferential arc segment balloon area and away from the rest of the circumferential arc segment balloon area; when a voltage is applied between the discharge electrodes 302, the discharge electrodes 302 are configured to emit discharge shock waves in the liquid in the balloon 1; when the balloon 1 is delivered to the lesion position, it can be adjusted so that the part of the circumferential arc segment balloon area close to the discharge electrode 302 is attached to the vascular calcification lesion position, and the rest of the circumferential arc segment balloon area away from the discharge electrode 302 is attached to the blood vessel position without calcification lesions. This allows the treatment area with calcified lesions in the circumferential direction of the blood vessel to obtain greater shock wave energy; at the same time, it reduces the shock wave energy applied to the non-treatment area in the circumferential direction of the blood vessel;

[0037] When the balloon 1 moves in the blood vessel, in order to improve the passability, it is generally in a folded state to reduce the cross-sectional area; when the distal end of the electrode support 301 is placed in the balloon 1, since the distal end of the electrode support 301 extends toward the radial side wall of the balloon 1, this will make it impossible for the balloon 1 to be completely folded, thereby increasing the cross-sectional area of ​​the balloon 1 when moving in the blood vessel; for this reason, the electrode support 301 of this embodiment is movable, and when the balloon 1 is in a folded state, the electrode support 301 and the discharge electrode 302 are placed in the electrode cavity outside the balloon 1.

[0038] The electrode inner cavity is used to accommodate the electrode assembly, and the electrode inner cavity can be of any shape.

[0039] In this embodiment, optionally, the electrode lumen extends axially along the catheter 2. Figure 2As shown, the electrode support 301 includes a guide section 3012 and a support section 3011 connected to the distal end of the guide section 3012; the discharge electrode 302 is arranged on the support section 3011; the guide section 3012 is located in the electrode lumen and can move axially along the electrode lumen, and the proximal end of the guide section 3012 can extend outside the body, so that the doctor can operate the electrode support 301 to advance and withdraw along the catheter 2; there is a bending angle between the support section 3011 and the guide section 3012 in a free state, so that the support section 3011 extends toward the radial side wall of the balloon 1, and the bending angle can be selected at any angle, such as 90°, 120°. When the electrode support 301 is delivered to the lesion site along the catheter 2, the position of the discharge electrode 302 along the axial direction of the balloon 1 can also be adjusted, and the discharge electrode 302 is closer to the lesion site.

[0040] Optionally, the connection between the support segment 3011 and the guide segment 3012 is made of a bendable elastic deformable material; for example, a nickel-titanium wire coated with an insulating layer may be used; the support segment 3011 and the guide segment 3012 are pre-plasticized so that the support segment 3011 and the guide segment 3012 have a bending angle in a free state. Optionally, the electrode support 301 is made of a nickel-titanium wire coated with an insulating layer. When the balloon 1 is in a folded state, the electrode support 301 and the discharge electrode 302 are withdrawn into the electrode cavity outside the balloon 1, and the bending angle between the support segment 3011 and the guide segment 3012 may be increased by the force of the electrode cavity, for example, close to 180°; and when the balloon 1 is in an unfolded state, the support segment 3011 and the guide segment 3012 can be pushed into the balloon 1 and restored to the bending angle in a free state.

[0041] Optionally, the catheter 2 includes an inner catheter 201 and an outer catheter 202;

[0042] The balloon 1 is sleeved on the outer circumference of the inner catheter 201, and the distal end of the balloon 1 is sealed and connected to the inner catheter 201;

[0043] The outer catheter 202 is sleeved on the outer periphery of the inner catheter 201 ; the distal end of the outer catheter 202 is connected to the proximal end of the balloon 1 ; the inner wall of the outer catheter 202 and the outer wall of the inner catheter 201 define a channel, and the channel is used to infuse liquid into the balloon 1 .

[0044] When the balloon 1 is in a folded state, the electrode support 301 and the discharge electrode 302 are placed in the channel. Figure 3As shown, the electrode assembly also includes an electrode sleeve 303; the electrode sleeve 303 is located in the channel and extends along the axial direction of the channel; the tubular cavity of the electrode sleeve 303 constitutes the electrode inner cavity, and a seal, such as a silicone valve, is provided between the electrode inner cavity and the balloon 1 to prevent the liquid in the balloon 1 from communicating with the electrode inner cavity; another optional scheme is that the channel is a single undivided cavity, and the channel as a whole serves as the electrode inner cavity, that is, the electrode support 301 and the discharge electrode 302 are directly connected to the injected liquid, and the electrode support 301, the discharge electrode 302 and the injected liquid share the channel.

[0045] In this embodiment, optionally, the number of the electrode assembly may be one; or, the number of the electrode assembly is at least two, and at least two of the electrode assemblies are arranged circumferentially along the catheter 2 .

[0046] In an optional embodiment, the device is used to treat heart valve calcification; Figure 4 As shown, since the aortic valve is composed of three leaflets 4, the number of the electrode assemblies is three; and the three electrode assemblies are arranged along the circumference of the catheter 2, corresponding to the three leaflets 4 one by one. Optionally, each of the electrode assemblies is provided with an independent electrode sleeve 303, so that the three electrode supports 301 move in the separated electrode cavities, and the three electrode supports 301 will not be entangled in contact in the catheter 2. Optionally, each of the electrode assemblies can be independently controlled for power supply.

[0047] During treatment, firstly, the three electrode supports 301 are placed in the electrode inner cavity, the balloon 1 is in a folded state, and then the balloon 1 is pushed to the heart valve; according to the calcification lesions of the three leaflets 4, the treatment leaflet 4 that needs shock wave treatment is determined, and the electrode assembly corresponding to the treatment leaflet 4 is pushed into the balloon 1 through the electrode support 301. When the corresponding electrode assembly is in the balloon 1, the distal end of the corresponding electrode support 301 extends toward the treatment leaflet 4, and the distance between the corresponding electrode assembly and the treatment leaflet 4 is relatively short, so that the shock wave energy applied by the corresponding electrode assembly to the treatment leaflet 4 is larger, and the shock wave energy applied to the remaining leaflets 4 is smaller.

[0048] When two or more leaflets 4 require shock wave treatment, the corresponding electrode assemblies can be pushed into the balloon 1 at the same time to generate discharge shock waves; or the corresponding electrode assemblies can be pushed into the balloon 1 in turn to generate discharge shock waves.

[0049] The electrode assembly in this embodiment has an optional solution, wherein the electrode assembly further comprises a guide shield disposed on the electrode support 301; the guide shield surrounds the outer periphery of the discharge electrode 302, and the guide shield is provided with an opening toward the distal end of the electrode support 301. The guide shield enables the shock wave energy to be better concentrated and propagated toward the distal end of the electrode support 301, and applied to the partial circumferential arc segment balloon region close to the discharge electrode 302.

[0050] Specifically, the guide cover may be cylindrical; or, the guide cover may be trumpet-shaped, and the cross-sectional area of ​​the distal end section of the guide cover is larger than the cross-sectional area of ​​the proximal end section.

[0051] In an optional embodiment, if Figure 5 As shown, the discharge electrode 302 includes

[0052] A first inner electrode 3021 disposed on the electrode support 301;

[0053] A second inner electrode 3022 disposed on the electrode support 301;

[0054] An outer electrode sheath 3023 surrounding the first inner electrode 3021 and the second inner electrode 3022; the outer electrode sheath 3023 is provided with an opening toward the distal end of the electrode support 301; the outer electrode sheath 3023, the first inner electrode 3021 and the second inner electrode 3022 are insulated and separated respectively;

[0055] When voltage is applied between the first inner electrode 3021 and the second inner electrode 3022, a discharge arc is generated between the first inner electrode 3021 and the outer electrode sheath 3023, and a discharge arc is generated between the outer electrode sheath 3023 and the second inner electrode 3022, so that current flows through the first inner electrode 3021, the outer electrode sheath 3023, and the second inner electrode 3022 in sequence; the positions where the discharge arcs occur are all located in the area surrounded by the outer electrode sheath 3023, and the outer electrode sheath 3023 constitutes the guide cover, which gathers the shock wave energy so that the shock wave energy can propagate along the opening of the outer electrode sheath 3023 toward the distal end of the electrode support 301, and be applied to the partial circumferential arc segment balloon area close to the discharge electrode 302.

[0056] In an optional specific embodiment, the first inner electrode 3021 and the second inner electrode 3022 are both insulated wires, and the outer electrode sheath 3023 is a bare conductor; the conductor at the distal end face of the first inner electrode 3021 is exposed, and the conductor at the distal end face of the second inner electrode 3022 is exposed; the distal end face of the first inner electrode 3021 and the distal end face of the second inner electrode 3022 are both located in the area surrounded by the outer electrode sheath 3023. When a voltage is applied between the first inner electrode 3021 and the second inner electrode 3022, a discharge arc is generated between the distal end face of the first inner electrode 3021 and the outer electrode sheath 3023, and a discharge arc is generated between the outer electrode sheath 3023 and the distal end face of the second inner electrode 3022, so that the current flows through the first inner electrode 3021, the outer electrode sheath 3023, and the second inner electrode 3022 in sequence, and a discharge shock wave is generated in the area surrounded by the outer electrode sheath 3023.

[0057] It should be noted that, in the description of this specification, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of this specification, unless otherwise specified, the meaning of "plurality" is two or more.

[0058] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with the technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit of the present application should be included in the protection scope of the present application.

[0059] It should be understood that the above description is for illustration and not for limitation. By reading the above description, many embodiments and many applications beyond the provided examples will be apparent to those skilled in the art. For comprehensive purposes, all articles and references, including the disclosures of patent applications and announcements, are incorporated herein by reference.

Claims

1. A shock wave balloon catheter device, characterized in that: include A balloon; the balloon has a folded state and an unfolded state; the balloon can be filled with liquid; The balloon surrounds the outer circumference of the catheter; An electrode lumen is provided in the catheter; the electrode lumen is located in the catheter on the proximal side of the balloon; An electrode assembly; the electrode assembly comprises An elongated electrode support; when the balloon is in an expanded state, the distal end of the electrode support is placed in the balloon, and the distal end of the electrode support extends toward the radial side wall of the balloon; Discharge electrode; The discharge electrode is arranged at the distal end of the electrode support; when the balloon is in an expanded state, the discharge electrode is placed in the balloon, and when a voltage is applied between the discharge electrodes, the discharge electrode is configured to emit a discharge shock wave in the liquid in the balloon; when the balloon is in a folded state, the electrode support and the discharge electrode are placed in the electrode inner cavity.

2. The device according to claim 1, characterized in that: The electrode lumen extends axially along the catheter; the electrode support comprises a guide segment and a support segment connected to the distal end of the guide segment; the guide segment is located in the electrode lumen and can move axially along the electrode lumen; a bending angle is provided between the support segment and the guide segment so that the support segment extends toward the radial side wall of the balloon; and the discharge electrode is arranged on the support segment.

3. The device according to claim 1, characterized in that: The connection between the support section and the guide section is made of a bendable elastic deformable material; in a free state, there is a bending angle between the support section and the guide section.

4. The device according to claim 1, characterized in that: The catheter comprises an inner catheter and an outer catheter; The balloon is sleeved on the outer circumference of the inner catheter, and the distal end of the balloon is sealed and connected to the inner catheter; The outer catheter is sleeved on the outer periphery of the inner catheter; the distal end of the outer catheter is connected to the proximal end of the balloon; the inner wall of the outer catheter and the outer wall of the inner catheter define a channel, and the channel is used to infuse liquid into the balloon; when the balloon is in a folded state, the electrode support and the discharge electrode are placed in the channel.

5. The device according to claim 1, characterized in that: The electrode assembly further comprises an electrode sleeve; the electrode sleeve is located in the channel and extends along the axial direction of the channel; the lumen of the electrode sleeve constitutes the electrode inner cavity.

6. The device according to claim 5, characterized in that: A seal is provided between the electrode lumen and the balloon.

7. The device according to claim 1, characterized in that: The number of the electrode assemblies is at least two, and at least two of the electrode assemblies are arranged along the circumference of the catheter.

8. The device according to claim 1, characterized in that: The device is used to treat heart valve calcification; the number of the electrode assemblies is three; and the three electrode assemblies are arranged along the circumference of the catheter.

9. The device according to claim 1, characterized in that: The electrode assembly further comprises a guide cover arranged on the electrode support; the guide cover surrounds the outer periphery of the discharge electrode and is provided with an opening facing the distal end of the electrode support.

10. The device according to claim 9, characterized in that: The guide cover is cylindrical; or, The guide cover is trumpet-shaped, and the cross-sectional area of ​​the distal end section of the guide cover is larger than the cross-sectional area of ​​the proximal end section.

11. The device according to claim 1, characterized in that: The discharge electrode comprises a first inner electrode disposed on the electrode support; a second inner electrode disposed on the electrode support; An outer electrode sheath surrounding the first inner electrode and the second inner electrode; the outer electrode sheath is provided with an opening toward the distal end of the electrode support; the outer electrode sheath, the first inner electrode and the second inner electrode are insulated and separated respectively; When a voltage is applied between the first inner electrode and the second inner electrode, a discharge arc is generated between the first inner electrode and the outer electrode sheath, and a discharge arc is generated between the outer electrode sheath and the second inner electrode, so that current flows through the first inner electrode, the outer electrode sheath, and the second inner electrode in sequence; the locations where the discharge arcs occur are all located within the area surrounded by the outer electrode sheath.

12. The device according to claim 11, characterized in that: The first inner electrode and the second inner electrode are both insulated wires; the conductor at the distal end surface of the first inner electrode is exposed, and the conductor at the distal end surface of the second inner electrode is exposed; the distal end surface of the first inner electrode and the distal end surface of the second inner electrode are both located in the area surrounded by the outer electrode sheath.

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