A laser cutting sheath and laser cutting method

Abstract

The application provides a laser cutting sheath, and belongs to the technical field of electrode lead cutting devices, and comprises a sheath body, an optical fiber and a laser head; the inner cavity of the sheath body can accommodate and pass through an electrode lead; and the optical fiber head emits laser suitable for cutting the electrode lead. The laser cutting sheath provided by the application cuts off the electrode lead through laser cutting; after the laser cuts off the electrode lead, the cut-off electrode lead comes out together with the sheath body, the cutting of the electrode lead is completed, the laser cutting can avoid many transmission mechanisms and mechanical structures, the laser cutting intensity is reliable, the laser cutting does not need to be performed for multiple times, the myocardial rupture injury cannot be caused by the laser cutting, the operation is safer, the operation difficulty of doctors is greatly reduced, and due to the characteristics of precision and rapidness of the laser cutting, the electrode head end is cut and separated by the laser cutting mode, the electrode head end can be accurately and rapidly cut, the operation complications are reduced, the operation of doctors is simplified, and the operation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode wire cutting devices, and in particular to a laser cutting sheath and a laser cutting method. Background Art

[0002] A pacemaker is typically implanted in a subcutaneous tissue pocket in the patient's chest wall. A pacemaker lead extends from the pacemaker through a vein and into a chamber of the patient's heart. The lead is used to conduct electrical signals (such as stimulation and / or mapping signals) between the pacemaker and the heart. The lead body is typically a composite tubular structure, with the inner and outer layers made of a low-hardness polymer material, such as TPU and / or silicone, and a metal coil between the inner and outer layers for conducting electrical signals. An anchoring structure, such as a barb or spiral thorn, is also provided at the tip of the lead. During implantation, the lead tip is anchored to the myocardium to prevent it from falling off due to external forces.

[0003] Within half a year after the electrode wire is implanted in the human body, its tip end will be wrapped and grown together with the endocardium. The longer the implantation time, the greater the wrapping force of the tissue and the higher the firmness. These wrapping forces are conducive to the positioning of the electrode, making the electrode less likely to be dislocated by external forces. However, when the electrode wire becomes infected or fails itself or for various other reasons, it needs to be removed or extracted from the body, these tissue wrapping forces will hinder the removal of the electrode, bringing great risks and difficulties to the operation.

[0004] like Figure 1 As shown, RV is the right atrium and LV is the right ventricle. After the electrode wire is implanted in the apex of the right atrium, it is very easy to cause myocardial tissue tearing and damage when the electrode wire is removed, causing harm to the patient and bringing great risks to the operation.

[0005] Therefore, some people have proposed using a cutter to remove the electrode wire, leaving the electrode head in the body, thus avoiding damage to the patient when the electrode wire is removed. The existing cutter is usually a rotating blade set in the target tube. The rotating blade is transported to the position of the electrode wire to be cut through the target tube, and then the rotating blade is controlled to perform rotary cutting to separate the electrode wire from the electrode head and pull the electrode wire out of the human body. In this cutting method, the rotating blade and its control rotating device are both mechanical structures with flexible transmission. Due to the size of the electrode wire, the size of the target tube, rotating blade and control rotating device are relatively small. Not only the manufacturing precision is high, but also the installation and matching precision is high. The strength of the parts may not meet the requirements. When cutting the electrode wire, multiple cuts may be performed, which increases the difficulty of cutting. Summary of the Invention

[0006] Therefore, the present invention provides a laser cutting sheath and a laser cutting method.

[0007] In order to solve the above technical problems, the present invention provides a laser cutting sheath, comprising:

[0008] Sheath body, optical fiber and laser head;

[0009] The sheath tube body is a tubular structure, and the inner cavity of the sheath tube body can accommodate and pass the electrode wire;

[0010] The optical fiber is arranged axially inside the sheath body along the sheath body, the optical fiber head is connected to the end of the optical fiber, and the optical fiber head is located at the distal end of the sheath body. The direction of the laser emitted by the optical fiber head is toward the inner cavity of the sheath body, and the emitted laser is suitable for cutting the electrode wire.

[0011] Optionally, the laser head includes a reflector and a focusing mirror optically coupled in sequence, the reflector is suitable for receiving laser light transmitted by an optical fiber, and the focus of the focusing mirror is located at the position of the electrode wire inside the sheath body.

[0012] Optionally, the reflector has a reflective surface, and the angle between the reflective surface and the axis of the sheath body is 45±10 degrees; the angle between the plane normal of the focusing mirror and the axis of the sheath body is 90±10 degrees.

[0013] Optionally, it further comprises a first lumen, which is arranged on the sheath tube body along the axial direction of the sheath tube body;

[0014] One end of the first cavity is adapted to be connected to the injection device, and the other end is adapted to be communicated with the inner cavity of the sheath body, and the position where the other end communicates with the inner cavity of the sheath body matches the position of the laser head.

[0015] Optionally, the injection device is a physiological saline injection device.

[0016] Optionally, a one-way valve is provided at the distal end of the sheath body, and the one-way valve is only suitable for allowing the electrode wire to pass through.

[0017] Optionally, the one-way valve is an elastic seal. After the electrode wire pierces or passes through the elastic seal, the elastic seal fills and seals the gap between the electrode wire and the one-way valve under its own elastic action.

[0018] Optionally, a correction piece is further included, the correction piece is located in the sheath body, and a position on the correction piece suitable for passing the electrode wire coincides with the axis of the sheath body;

[0019] The correction member is arranged close to the laser head and is at least partially located near the electrode wire cutting position;

[0020] The two sides of the cutting position on the electrode wire are respectively the proximal side and the distal side, wherein the end with the electrode head is the distal side.

[0021] Optionally, the correction member is a coaxial spring piece, which is annular and arranged in the sheath body. The coaxial spring piece is provided with a through hole suitable for the electrode wire to pass through, and the through hole is coaxial with the sheath body.

[0022] The coaxial spring piece is located at the distal end of the sheath body, close to the laser head, and is located proximal to the electrode wire cutting position.

[0023] Optionally, the correction member is a coaxial spring piece, which is cylindrical and arranged in the sheath body. The cylindrical coaxial spring piece is coaxial with the sheath body, and a through hole suitable for the electrode wire to pass through is opened on the coaxial spring piece.

[0024] The two ends of the coaxial spring are respectively located on both sides of the position where the electrode wire is to be cut. An opening is provided on the side wall of the coaxial spring to allow the laser to pass through, and through holes are provided on the end faces of both ends of the coaxial spring to allow the liquid to pass through.

[0025] A laser cutting method is also provided, comprising the laser cutting sheath described above, further comprising the following steps:

[0026] The sheath body is sleeved on the electrode wire and moves along the electrode wire toward the electrode head;

[0027] After the laser head on the sheath body moves to the position to be cut, the laser transmitted by the laser head cuts the electrode wire, separating the electrode head from the electrode wire;

[0028] After the cutting is completed, the cutting sheath and the cut electrode wire are taken out together.

[0029] The technical solution of the present invention has the following advantages:

[0030] 1. The laser cutting sheath provided by the present invention has an optical fiber and an optical fiber head arranged in the sheath body, and then the electrode wire is passed through the sheath body. After the optical fiber head is transported to the position of the electrode wire to be cut, the electrode wire is cut by laser cutting. After the laser cuts the electrode wire, the cut electrode wire comes out together with the sheath body, completing the cutting of the electrode wire. The use of laser cutting can avoid many mechanical structures such as transmission mechanisms. The laser cutting strength is reliable and there is no need for multiple cuttings. This method will not cause myocardial rupture and damage, and the operation is safer and greatly reduces the difficulty of the doctor's operation. At the same time, since laser cutting has the characteristics of precision and speed, the electrode tip end is cut and separated by laser cutting, which can accurately and quickly cut the electrode tip end, reduce surgical complications, simplify the doctor's operation, and improve surgical efficiency.

[0031] 2. The laser cutting sheath provided by the present invention includes a reflector and a focusing mirror optically coupled in sequence. The reflector can avoid bending of the optical fiber end and ensure the transmission stability of the optical fiber. The focusing mirror can focus the laser emitted by the optical fiber, concentrate the energy to the focal position, and cut the electrode wire.

[0032] 3. The laser cutting sheath provided by the present invention is provided with a first lumen on the sheath body, one end of the first lumen is connected to the injection device, and the other end is connected to the inner cavity of the sheath body, wherein the injection device is a physiological saline injection device, and by injecting physiological saline into the first lumen, the transmittance of the laser can be improved, and the laser cutting efficiency can be improved; at the same time, the laser can be prevented from causing ablation damage to the blood; in the process of physiological saline circulating along the first lumen and the inner cavity, foreign matter generated during the cutting process can also be discharged, further improving safety; continuous injection of physiological saline can also transfer heat to prevent local overheating during the cutting process, further improving surgical safety.

[0033] 4. The laser cutting sheath provided by the present invention and the setting of the correction piece can ensure that the electrode wire is coaxial with the sheath tube body, ensure the stability and consistency of the laser focal length, and improve product performance and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a schematic diagram of the structure of directly pulling out the electrode head in the prior art;

[0036] Figure 2 A schematic structural diagram of a laser cutting sheath provided in an embodiment of the present invention;

[0037] Figure 3 A cross-sectional view of a laser cutting sheath provided in an embodiment of the present invention;

[0038] Figure 4 A schematic diagram of the optical circuit of a laser head for laser sheath cutting according to an embodiment of the present invention;

[0039] Figure 5 A schematic diagram of the liquid flow direction in the first lumen of the laser cutting sheath provided in an embodiment of the present invention;

[0040] Figure 6 A schematic structural diagram of a first embodiment of a one-way valve provided in an embodiment of the present invention;

[0041] Figure 7 A schematic structural diagram of a second embodiment of a one-way valve provided in an embodiment of the present invention;

[0042] Figure 8 A schematic diagram of a first connection structure between a correction member and a sheath tube body provided in an embodiment of the present invention;

[0043] Figure 9 A schematic structural diagram of a first embodiment of a calibration component provided by an embodiment of the present invention;

[0044] Figure 10 A schematic diagram of a second connection structure between the correction member and the sheath tube body provided in an embodiment of the present invention;

[0045] Figure 11 A schematic structural diagram of a second embodiment of the correction component provided in an embodiment of the present invention.

[0046] Description of reference numerals:

[0047] 2. Electrode wire; 4. Inner cavity; 10. Sheath body; 11. Optical fiber; 12. Reflector; 13. Focusing mirror; 14. One-way valve; 15. First cavity; 16. Coaxial shrapnel. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be noted that the terms "proximal", "distal" and "axial" are commonly used terms in the field of interventional medicine. Specifically, "distal" refers to the end away from the operator during the surgical operation; "proximal" refers to the end close to the operator during the surgical operation; "axial" refers to the direction of the device's central axis, and the radial direction is the direction perpendicular to the central axis. The terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. In addition, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0050] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0051] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0052] Example 1

[0053] This embodiment provides a specific implementation of laser cutting sheath, such as Figure 2 、 Figure 3 and Figure 4 As shown, an optical fiber 11 and an optical fiber 11 head are arranged in the sheath body 10, and then the electrode wire 2 is passed through the sheath body 10. After the optical fiber 11 head is transported to the position of the electrode wire 2 to be cut, the electrode wire 2 is cut by laser cutting. After the laser cuts the electrode wire 2, the cut electrode wire 2 comes out together with the sheath body 10, completing the cutting of the electrode wire 2. Laser cutting can avoid many mechanical structures such as transmission mechanisms. The laser cutting strength is reliable and there is no need for multiple cuttings. This method will not cause myocardial rupture damage, and the operation is safer and greatly reduces the difficulty of the doctor's operation. At the same time, since laser cutting has the characteristics of precision and speed, the electrode tip end can be cut and separated by laser cutting, which can accurately and quickly cut the electrode tip end, reduce surgical complications, simplify the doctor's operation, and improve surgical efficiency.

[0054] In this embodiment, Figure 3 and Figure 4 As shown, the laser head includes a reflector 12 and a focusing mirror 13 optically coupled in sequence. The reflector 12 prevents bending of the end of the optical fiber 11, ensuring the transmission stability of the optical fiber 11. The focusing mirror 13 is provided to focus the laser light emitted by the optical fiber 11, concentrating the energy at the focal point and cutting the electrode wire 2. If the reflector is not provided, the end of the optical fiber 11 needs to be bent 90 degrees, which greatly reduces the propagation effect of the optical fiber 11. Specifically, the reflector 12 has a reflective surface, and the reflective surface and the axis of the sheath body 10 are at an angle of 45±10 degrees. The plane normal of the focusing mirror 13 and the axis of the sheath body 10 are at an angle of 90±10 degrees.

[0055] In this embodiment, Figure 2 and Figure 5As shown, a first lumen 15 is provided on the sheath body 10, one end of the first lumen 15 is connected to the injection device, and the other end is connected to the inner cavity 4 of the sheath body 10, wherein the inner cavity 4 of the sheath body 10 is a second lumen. Specifically, the injection device is a saline injection device. During the cutting process, saline can be continuously injected into the first lumen 15 through the saline injection device. Since the distal end of the sheath body 10 is in the heart cavity filled with blood, the light transmittance is poor, and saline has high light transmittance. By injecting saline into the first lumen 15, the light transmittance of the laser can be improved, and the laser heat can be prevented from being absorbed by the blood, thereby improving safety and laser cutting efficiency; at the same time, it can avoid laser ablation damage to the blood; in the process of saline circulating along the first lumen 15 and the inner cavity 4, foreign matter generated during the cutting process can also be discharged, further improving safety; continuous injection of saline can also transfer heat, prevent local overheating during the cutting process, and further improve surgical safety.

[0056] In this embodiment, a one-way valve 14 is also included, which is arranged at the distal end of the sheath body 10. The one-way valve 14 is only suitable for allowing the electrode wire 2 to pass through, that is, when the end of the electrode wire 2 exposed on the outside passes through the sheath end during the advancement of the sheath body 10, it also passes through the one-way valve 14. The one-way valve 14 isolates the internal space of the sheath body 10 from the outside, preventing saline from flowing into the blood during the cutting process. At the same time, the one-way valve 14 can also prevent foreign matter generated during the cutting process from flowing into the blood.

[0057] Specifically, the one-way valve 14 is an elastic seal, which can be made of materials such as silicone, TPF, and TPE. After the electrode wire 2 pierces or passes through the elastic seal, the elastic seal, under its own elastic action, fills and seals the gap between the electrode wire 2 and the one-way valve 14. Moreover, after the cutting is completed, when the sheath body is withdrawn outward, when the severed electrode wire 2 is separated from the one-way valve 14, the elastic seal, under its own elastic action, fills and seals the hole previously penetrated by the electrode wire 2, thereby minimizing the flow of saline into the blood through the distal end of the sheath body 10.

[0058] Specifically, such as Figure 6 As shown, a small hole is pre-opened on the elastic seal, which is coaxial with the sheath body 10 to facilitate the insertion of the electrode wire 2. The diameter of the small hole is close to or smaller than the diameter of the electrode wire 2. When the electrode wire 2 passes through the one-way valve 14, it can play a good sealing role. The physiological saline will not enter the human body, but will be discharged from the body through the inner cavity 4 of the sheath.

[0059] As an alternative embodiment, Figure 7As shown, a cross-shaped or star-shaped incision is provided in the center of the elastic seal, and the width of the incision is close to or smaller than the diameter of the electrode wire 2. By adopting the cross-shaped or star-shaped incision, the incision can be automatically closed under the elastic action of the elastic seal when the sheath body 10 is withdrawn from the body, and the risk of residues generated during the cutting process entering the human body is lower.

[0060] The setting of the correction piece can ensure that the electrode wire 2 is coaxial with the sheath tube body 10, ensure the stability and consistency of the laser focal length, and improve product performance and safety.

[0061] In this embodiment, the correction member is a coaxial spring piece 16, such as Figure 8 and Figure 9 As shown, the coaxial spring clip 16 is annular and disposed within the sheath body 10. The coaxial spring clip 16 is provided with a through hole through which the electrode wire 2 can pass. The through hole is coaxially arranged with the sheath body 10, and the coaxial spring clip 16 is located at the distal end of the sheath body 10, close to the laser head. The coaxial spring clip 16 is located proximal to the position to be cut of the electrode wire 2. The coaxial spring clip 16 and the end of the sheath body 10 jointly support the electrode wire 2, keeping the position to be cut of the electrode wire 2 on the axis of the sheath body 10, facilitating the laser head to cut the electrode wire 2 and preventing the electrode wire 2 from deviating without support, making cutting difficult for the laser head.

[0062] As an alternative embodiment, the correction member is a coaxial spring piece 16, which is cylindrical, such as Figure 10 and Figure 11 As shown, a cylindrical coaxial spring clip 16 is arranged in the sheath body 10, and the cylindrical coaxial spring clip 16 is coaxially arranged with the sheath body 10. A through hole is provided on the coaxial spring clip 16 to allow the electrode wire 2 to pass through. In this arrangement of the coaxial spring clip 16, the two ends of the coaxial spring clip 16 are respectively located on both sides of the position of the electrode wire 2 to be cut, so that when the electrode wire 2 is passed through the through hole, the two ends of the coaxial spring clip 16 can support the electrode wire 2, so that the position of the electrode wire 2 to be cut is at the axial position of the sheath body 10; an opening is provided on the side wall of the coaxial spring clip 16, and the laser emitted by the laser head can hit the electrode wire 2 in the coaxial spring clip 16 through the opening; through holes are provided on the end faces of both ends of the coaxial spring clip 16, and the liquid injected by the injection device can pass through the through holes in the inner cavity 4.

[0063] This embodiment also includes a handle located at the proximal end of the sheath body 10. The handle is provided with an optical fiber 11 interface. During the operation, the optical fiber 11 interface is connected to the laser generator. The laser can use a 1064nm wavelength light source, which has high stability, high performance, and fast operation speed. During the operation, the laser is emitted from the laser generator, transmitted to the laser head through the optical fiber 11, and then the laser direction is changed by the reflector 12. The focusing mirror 13 focuses the laser, and finally the laser is directed to the surface of the electrode wire 2, thereby cutting and cutting the electrode wire 2. The handle is provided with a rotating mechanism coupled to the sheath body 10. The rotating mechanism can drive the sheath body 10 to rotate. The rotating mechanism can use a motor. During the operation of the handle, the device is connected to the electrical interface, driving the motor to rotate, thereby circumferentially cutting the electrode wire 2 and separating it as a whole.

[0064] As an alternative embodiment, multiple optical fibers 11 and laser heads can be provided, which are arranged circumferentially in the sheath body 10, with their focal positions all facing the position of the electrode wire 2. In this way, there is no need for the sheath body 10 to rotate, and multiple laser heads can emit lasers synchronously to cut off the electrode wire 2 as a whole.

[0065] Example 2

[0066] This embodiment provides a specific implementation method of the laser cutting method, which is implemented using the laser cutting sheath in Example 1, and includes the following steps: the sheath body is placed on the electrode wire and moves along the electrode wire toward the electrode head; after the laser head on the sheath body moves to the position to be cut, the laser transmitted by the laser head cuts the electrode wire to separate the electrode head from the electrode wire; after the cutting is completed, the cutting sheath is connected to the cut electrode wire and taken out together.

[0067] Laser cutting does not require complex mechanical structures and the structure is simple and easy to operate.

[0068] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A laser cutting sheath, characterized in that: include: Sheath body, optical fiber and laser head; The sheath tube body is a tubular structure, and the inner cavity of the sheath tube body can accommodate and pass the electrode wire; The optical fiber is arranged axially inside the sheath tube body, the optical fiber head is connected to the end of the optical fiber, and the optical fiber head is located at the distal end of the sheath tube body. The direction of the laser emitted by the optical fiber head is toward the inner cavity of the sheath tube body, and the emitted laser is suitable for cutting the electrode wire; The sheath tube body further comprises a first lumen, wherein the first lumen is arranged on the sheath tube body along the axial direction of the sheath tube body; One end of the first cavity is adapted to be connected to the injection device, and the other end is adapted to be communicated with the inner cavity of the sheath tube body, and the position where the other end communicates with the inner cavity of the sheath tube body matches the position of the laser head; A one-way valve is provided at the distal end of the sheath body, and the one-way valve is only suitable for allowing the electrode wire to pass through; Also included is a correction piece, the correction piece is located in the sheath body, and the position of the correction piece suitable for passing the electrode wire coincides with the axis of the sheath body; The correction member is arranged close to the laser head and is at least partially located near the electrode wire cutting position; The two sides of the cutting position on the electrode wire are respectively the proximal side and the distal side, wherein the end with the electrode head is the distal side.

2. The laser cutting sheath according to claim 1, characterized in that The laser head comprises a reflector and a focusing mirror optically coupled in sequence. The reflector is suitable for receiving laser light transmitted by an optical fiber. The focus of the focusing mirror is located at the position of the electrode wire in the sheath body.

3. The laser cutting sheath according to claim 2, characterized in that The reflector has a reflective surface, and the angle between the reflective surface and the axis of the sheath tube body is 45±10 degrees; the angle between the plane normal of the focusing mirror and the axis of the sheath tube body is 90±10 degrees.

4. The laser cutting sheath according to claim 1, characterized in that The injection device is a physiological saline injection device.

5. The laser cutting sheath according to claim 1, characterized in that The one-way valve is an elastic sealing member. After the electrode wire pierces or passes through the elastic sealing member, the elastic sealing member fills and seals the gap between the electrode wire and the one-way valve under the elastic action of the elastic sealing member itself.

6. The laser cutting sheath according to claim 1, characterized in that The correction piece is a coaxial spring piece, which is annular and arranged in the sheath body. The coaxial spring piece is provided with a through hole suitable for the electrode wire to pass through, and the through hole is coaxial with the sheath body. The coaxial spring piece is located at the distal end of the sheath body, close to the laser head, and is located proximal to the electrode wire cutting position.

7. The laser cutting sheath according to claim 1, characterized in that The correction member is a coaxial spring piece, which is cylindrical and arranged in the sheath body. The cylindrical coaxial spring piece is coaxial with the sheath body and has a through hole suitable for the electrode wire to pass through. The two ends of the coaxial spring are respectively located on both sides of the position where the electrode wire is to be cut. An opening is provided on the side wall of the coaxial spring to allow the laser to pass through, and through holes are provided on the end faces of both ends of the coaxial spring to allow the liquid to pass through.

8. A laser cutting method comprising the laser cutting sheath according to any one of claims 1 to 7, characterized in that: The following steps are also included: The sheath body is sleeved on the electrode wire and moves along the electrode wire toward the electrode head; After the laser head on the sheath body moves to the position to be cut, the laser transmitted by the laser head cuts the electrode wire, separating the electrode head from the electrode wire; After the cutting is completed, the cutting sheath and the cut electrode wire are taken out together.

Images