WO2023236057A1

WO2023236057A1 - Electric snare

Info

Publication number: WO2023236057A1
Application number: PCT/CN2022/097441
Authority: WO
Inventors: 严航; 蔡大峰; 孔凡斌; 陈晨; 邱筱赛; 刘向飞
Original assignee: 上海诺英医疗器械有限公司
Priority date: 2022-06-07
Filing date: 2022-06-07
Publication date: 2023-12-14

Abstract

Disclosed is an electric snare, comprising an electric connector assembly, a traction cord, a snare wire, a loop electrode, a loop wire, a fixing screw, a drum spring, and a loop connecting rod, which are electrically connected in sequence. The head of the loop electrode has a certain radian. Further comprised are a sheath tube assembly having two layers of nested structure, the loop wire being arranged between the two layers of nested structures of the sheath tube assembly. The present invention utilizes the loop electrode and the snare wire serving as a transmitting electrode to form a dual-pole plasma electric snare. The energy outputted is low-frequency plasma energy. Thus, no negative pole plate is necessary to be attached to the body of a patient during surgery, the current can directly reach the loop electrode by means of the snare wire so as to form a loop without flowing through the human body, thereby removing the risk of arc burns.

Description

An electric snare

Technical field

The invention relates to the technical field of medical devices, and in particular to an electric snare used for endoscopic surgical resection of lesions.

Background technique

Most of the existing electric snares on the market are high-frequency monopolar designs. When inserting an endoscope for surgery, a negative plate needs to be attached to the human skin to form a circuit. During the surgery, the high-frequency energy passes through the diseased tissue and human muscle tissue in sequence. When it reaches the negative plate, it will cause certain damage to the human body, and there will be a certain amount of eschar at the lesion after removal. Some electric snares do not have a 360° rotation function.

Chinese patent document CN215018830U discloses a bipolar electric snare, which includes a core rod, a slip ring, a first electrode, a second electrode, an outer tube and a snare. The slip ring is sleeved on the outside of the core rod, and the core rod is provided with sequential connections inside. The traction steel wire booster tube and the insulated inner tube are equipped with traction steel wires. The insulated inner tube is covered with an outer tube. The end of the outer tube is provided with a metal end cap. The traction steel wire passes through the metal The end cap is connected to the snare, the first electrode is fixed on the slip ring and connected to the traction steel wire booster tube, the second electrode is fixed on the end of the core rod and connected to the outer tube, the first electrode and the second electrode are both connected to The external high-frequency equipment is connected. The bipolar poles in this device are fixed on the operating handle. By turning on the power of the high-frequency equipment and applying external force, the snare moves into the insulated inner tube, which can achieve the effect of removing diseased tissue and eliminate the problem of easy alignment of the negative plate. It solves the problem of burns on the human body, has a simple structure and reliable performance.

Chinese patent document CN105286991A discloses an electric snare, which includes a control handle and a flexible sheath connected in sequence. A control steel wire is passed through the flexible sheath, and one end of the control steel wire is connected to a sliding handle provided on the control handle. The electrodes are connected, and the other end is provided with a ferrule with a guide head and extends to the distal end of the flexible sheath; the flexible sheath is also provided with a control cable, one end of which passes through the side of the control handle, and the other end One end is connected to the guide head of the ferrule. The electric snare of the present invention has the advantages of simple structure and easy control of the direction of the snare opening, and is suitable for removing polyps or tumors that grow along the axial direction of the pipeline.

Chinese patent document CN211094659U discloses a medical electric snare, which includes a tubular handle, a flexible sheath, a ferrule, an anchor head and a synchronous drive assembly. The end of the flexible sheath is fixedly connected to the front end of the tubular handle. The ferrule is connected to the synchronous drive component through a first traction rope, the anchor head is connected to the synchronous drive component through a second traction rope, the tubular handle is provided with a high-frequency electric plug, and the first traction rope Connected to the high-frequency electric plug, the first traction rope and the second traction rope move synchronously and reversely within the flexible sheath under the driving of the synchronous driving assembly. The medical electric snare can use a synchronous drive component to drive the snare and anchor head to move toward each other at the same speed, thereby enabling polyps to be recovered directly after polyp removal.

Chinese patent document CN215018830U discloses a bipolar electric snare. The bipolar electric snare is fixed on the operating handle. By turning on the power supply of the high-frequency equipment and applying external force, the snare moves into the insulated inner tube, which can achieve the effect of removing diseased tissue and eliminate It eliminates the problem that the negative plate easily causes burns to the human body, and has a simple structure and reliable performance.

The above three types of electric snares all have their own characteristics, but they are all high-frequency designs and cannot avoid accidental injury problems caused by excessive temperatures. Moreover, the return electrode of the electric snare described in CN215018830U is directly placed on the outside of the sheath, which may result in insufficient contact between the return electrode and the diseased tissue.

In summary, existing electric snares mainly have the following shortcomings:

1. Conventional high-frequency electric snares are all unipolar in design, and the energy output is high-frequency energy. During surgery, a negative electrode plate needs to be attached to the patient's exposed skin. The current will flow through the human body and reach the negative electrode plate, causing the risk of arc burns. . High-frequency energy not only acts on the surface of the tissue, but also penetrates into the lower layers of the tissue, causing greater thermal damage and slower postoperative recovery.

2. The loop electrode of the existing bipolar plasma electric snare is designed with an ordinary stainless steel tube. During the operation, there is a risk that the loop electrode will not be in sufficient contact with the tissue, thus failing to stimulate the plasma.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art by using a snare wire as a transmitting electrode and a loop electrode to form a bipolar plasma electric snare, so that the output energy is low-frequency plasma energy, and there is no need to attach a negative electrode to the patient during surgery. plate, the current will directly reach the return electrode through the snare wire to form a loop, without flowing through the human body, and there is no risk of arc burns.

In order to achieve the above object, the present invention provides an electric snare, which includes an electrical joint assembly, a traction rope, a snare wire, a loop electrode, a loop wire, a fixing screw, a drum spring and a loop connecting rod that are electrically connected in sequence. The loop electrode The head has a certain curvature; it also includes a sheath assembly with a two-layer nesting structure, and the circuit wire is sandwiched between the two-layer nesting structure of the sheath assembly.

Further, the head of the return electrode is spherical.

Further, the sheath assembly includes a concentric two-layer structure of an outer sheath tube and an inner sheath tube, and the outer sheath tube clamps the loop wire between the two-layer structures through heat shrinkage.

Further, the traction rope is arranged along the axis of the outer sheath, and the space between the inner wall of the inner sheath and the traction rope constitutes a launch chamber.

Further, the inner diameter of the return electrode is smaller than the outer diameter of the inner sheath. The inner sheath is reduced in diameter by extrusion and then inserted into the inner cavity of the return electrode to be fixed, forming a limit at the reduced diameter position. point, and the limiting point is adapted to block the connecting tube used to connect the snare wire and the traction rope from moving toward the mouth of the inner sheath.

Further, the return electrode and the outer sheath are nested and connected through an inverted tooth-shaped structure.

Further, the rear end of the inner sheath is connected to a front rod, and a perfusion chamber interface is radially provided on the outer wall of the front rod. The perfusion chamber interface extends inward and is connected to the perfusion chamber. The perfusion chamber Communicated with the inner sheath.

Further, the fixing screw is rotatably embedded in the end sleeve, and the front rod and the fixing screw are fixed as one body.

Further, one end of the loop connecting rod is sleeved with a fixed drum spring and is close to the inner wall of the end sleeve. The elastic drum-shaped outer wall of the drum spring is in close contact with the fixing screw, and the two are suitable for relative rotation. .

Further, an insulating tube is nested in the inner hole of the fixing screw, and the loop wire is squeezed between the fixing screw and the insulating tube.

Further, a step hole is provided at the end of the threaded hole for connecting the fixing screw at the rear end of the front rod. A sealing gasket is tightly fitted inside the step hole, and the fixing screw is coated with thread glue.

Further, a plastic gasket is provided between the sealing gasket and the fixing screw.

Further, the circuit connecting rod and the drum spring are connected by soldering.

Further, the electrical connector assembly includes a first electrical connector and a second electrical connector, the first electrical connector is electrically connected to the loop connecting rod, and the second electrical connector is electrically connected to the traction rope; The first electrical connector is a spring pin, so that the circuit connecting rod is adapted to maintain an electrical connection with the first electrical connector during sliding back and forth.

Further, the end surface of the spring pin in contact with the circuit connecting rod is a flat surface.

Further, the loop electrode and the loop wire are laser welded.

Compared with the prior art, the beneficial effects of the present invention are:

1. The snare wire as the transmitting electrode and the return electrode form a bipolar plasma electric snare. The output energy is low-frequency plasma energy. There is no need to attach a negative plate to the patient during surgery. The current will directly reach the return electrode through the snare wire to form a loop. It does not flow through the human body and there is no risk of arc burns. The energy excited during surgery is low-frequency plasma energy, which causes low thermal damage to tissues and will not deepen with the increase of surgical time, making the surgical process safer.

2. The loop electrode has a certain curvature, which will play a guiding role during the insertion of the endoscope, making the bending smoother. At the same time, this design can make the loop electrode more fully in contact with the tissue, and can well stimulate the plasma.

Description of the drawings

Figure 1 is a schematic structural diagram of an embodiment of the present invention;

Figure 2 is a schematic structural diagram of the head of an electric snare in one embodiment of the present invention;

Figure 3 is a schematic structural diagram of the handle end of the electric snare in one embodiment of the present invention;

Figure 4 is a partial enlarged view of the lower half of Figure 3;

Figure 5 is a schematic cross-sectional view of the sheath in one embodiment of the present invention;

Figure 6 is a schematic structural diagram of a loop electrode in one embodiment of the present invention;

Figure 7 is a schematic structural diagram of a drum spring in one embodiment of the present invention;

Figure 8 is a schematic structural diagram of a spring pin in one embodiment of the present invention.

In the picture:

1-trap wire (emitting electrode); 2-loop electrode; 2-1 inverted teeth; 3-outer sheath; 4-front rod; 4-1-perfusion chamber interface; 5-end sleeve; 6-electrical connector assembly ; 6-1-The first electrical connector (spring Pin); 6-2-The second electrical connector (Pin); 7-Handle; 8-Inner sheath; 8-1 Reducing position; 8-2 Limit Position; 9-connecting tube; 10-loop wire; 11-traction rope; 12-sealing gasket; 13-fixing screw; 14-insulating tube; 15-drum spring; 16-loop connecting rod; 17-launch chamber (water outlet) cavity).

Detailed ways

The following describes the embodiments of the present invention through specific examples in conjunction with the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

It should be noted that the directional words mentioned in this article, such as up, down, left, right, front, middle, back, bottom, top, inside, outside, etc., all refer to the directions shown in the figure. This is for convenience of description and is not intended to limit the invention in any way.

As shown in Figures 1 to 8, one embodiment of the electric snare of the present invention includes an electrical connector assembly 6, a traction rope 11, a snare wire 1, a loop electrode 2, a loop wire 10, a fixing screw 13, and a drum that are electrically connected in sequence. Spring 15 and loop connecting rod 16, the head of the loop electrode 2 has a certain curvature; it also includes a sheath assembly with a two-layer nesting structure, and the loop wire 10 is sandwiched between the two layers of the sheath assembly. between structures.

In this embodiment, the snare wire 1 as the transmitting electrode and the return electrode 2 are used to form a bipolar plasma snare. The current flows from the electrical connector assembly 6 through the traction rope 11, the snare wire 1, the diseased tissue, the return electrode 2, and The loop wire 10, fixing screw 13, drum spring 15 and loop connecting rod 16 then return to the electrical connector assembly 6 to form a loop. There is no need to attach a negative plate to the patient during surgery, the current does not flow through the human body, and the output energy is low-frequency plasma energy. No risk of arc burns. The energy excited during surgery is low-frequency plasma energy, which causes low thermal damage to tissues and will not deepen with the increase of surgical time, making the surgical process safer. Since the head of the return electrode 2 has a certain curvature, it will play a guiding role during the insertion of the endoscope, thereby making the bending smoother. At the same time, this design can make the return electrode 2 more fully in contact with the diseased tissue, forming a good current conduction effect.

In one embodiment, the head of the return electrode 2 is spherical. In this embodiment, the spherical structure is more rounded and smooth while maintaining a constant arc, which reduces the resistance during the insertion of the endoscope, and has a larger contact area with the diseased tissue, that is, the conductive area is larger and the resistance is smaller. It is easier to ignite plasma, which reduces the risk of insufficient contact between the loop electrode and the tissue during the operation, thus failing to ignite plasma. The current bipolar plasma electric snare loop electrode is designed with an ordinary stainless steel tube.

In one embodiment, as shown in Figure 5, the sheath assembly includes a concentric two-layer structure of an outer sheath 3 and an inner sheath 8. The outer sheath 3 shrinks the loop wire through heat shrinkage. 10 is clamped between the two layers. In this embodiment, the sheath assembly is designed with a double-layer tube structure, so that the snare wire 1 serving as the cutter head is always in the center position. When the double-lumen sheath is used, the snare wire is eccentric when it extends, resulting in the existence of the endoscopic field of view. A certain deviation makes the doctor's experience less effective than having a clearer view during surgery. The outer sheath 3 is a heat-shrinkable tube, which realizes the insulation between the loop and the launch branch, and ensures that the launch chamber 17 has enough space to work while the overall outer diameter of the sheath assembly will not be too large.

In one embodiment, as shown in Figure 5, the traction rope 11 is arranged along the axis of the outer sheath 3, and the space between the inner wall of the inner sheath 8 and the traction rope 11 constitutes Launch chamber 17. In this embodiment, the traction rope 11 is located at the center of the outer sheath 3. Since the head end of the traction rope 11 is connected to the snare wire 1, this ensures that the snare wire 1 is located in the center and expands the surgical field of view. This structure can also maximize the cross-sectional area of the emission chamber 17, so that the water output is large and slow, making the physiological saline and the snare wire 1 more fully in contact, ensuring continuous plasma excitation, and avoiding the plasma of current bipolar plasma electric snares. The medium saline flows out from the non-launch chamber, which may cause intraoperative risks due to insufficient contact between the saline and the snare wire.

In one embodiment, as shown in FIG. 6 , the inner diameter of the return electrode 2 is smaller than the outer diameter of the inner sheath 8 , and the inner sheath 8 is reduced in diameter by extrusion and then inserted into the return electrode 2 The inner cavity is fixed, and a limit point 8-2 is formed at the reducing position 8-1. The limit point 8-2 is suitable for blocking the direction of the connecting pipe 9 used to connect the snare wire 1 and the traction rope 11. The mouth direction of the inner sheath 8 moves. In this embodiment, the limit point 8-2 can block and limit the movement of the snare wire 1 to the left, so that the snare wire 1 will not protrude excessively from the inner sheath 8, which is precisely defined. The length of the snare wire 1 entering the lesion is conducive to accurately adjusting its entry length according to surgical needs to achieve better surgical results. It also solves the problem that the current connecting tube between the snare wire and the traction rope may extend out of the sheath, thus This causes problems such as lags during retrieval and inability to retract smoothly.

In one embodiment, as shown in FIG. 6 , the loop electrode 2 and the outer sheath 3 are nested and connected through an inverted tooth-shaped structure. In this embodiment, when the loop electrode 2 and the outer sheath 3 are pulled out, a large friction force will be generated between the inverted teeth and the sheath, thereby ensuring the connection strength and reducing the current problems caused by the loop electrode and the outer sheath 3. The sheaths are bonded together, which takes a long time to cure. At the same time, the sheaths are made of PTFE, which has the risk of falling off due to the non-stick surface.

In one embodiment, as shown in Figure 3, the rear end of the inner sheath 8 is connected to a front rod 4, and a perfusion chamber interface 4-1 is radially provided on the outer wall of the front rod 4. The cavity interface 4-1 extends inward and is connected to the perfusion cavity, and the perfusion cavity is connected to the inner sheath 8. In this embodiment, the perfusion chamber interface 4-1 is connected to the bagged physiological saline through an infusion set. The physiological saline reaches the snare wire 1 through the inner sheath 8, and then flows out from the root of the snare wire 1, stimulating the plasma effect and simultaneously treating the snare. The wire 1 is tightened, and the snare wire 1 contacts the lesion tissue to realize the cutting of the lesion tissue.

In one embodiment, as shown in FIG. 4 , the fixing screw 13 is rotatably embedded in the end sleeve 5 , and the front rod 4 and the fixing screw 13 are fixed as one body. In this embodiment, after the fixing screw 13 is connected to the front rod 4 to form a whole, there will be no axial displacement relative to the end sleeve 5 and the entire handle 7, but it can perform 360° axial rotation, making it more convenient during surgery. The angle can be adjusted accurately to snare the target tissue, which improves the convenience of the doctor's surgery, thereby improving the efficiency of the surgery. It overcomes the problem that the current bipolar electric snare cannot rotate 360° and requires high professionalism of the operator. defect.

In one embodiment, as shown in Figure 4, one end of the loop connecting rod 16 is sleeved with a fixed drum spring 15 and then closely adheres to the inner wall of the end sleeve 5. The elastic drum-shaped outer wall of the drum spring 15 is in contact with the said drum spring 15. The fixing screw 13 is in close contact and is suitable for relative rotation. In this embodiment, the drum spring 15 is elastically designed to ensure that the fixing screw 13 and the drum spring 15 are always in an electrically connected state when the front rod 4 rotates, and at the same time, it does not interfere with the rotation.

In one embodiment, as shown in FIG. 4 , an insulating tube 14 is nested in the inner hole of the fixing screw 13 , and the circuit wire 10 is squeezed between the fixing screw 13 and the insulating tube 14 . In this embodiment, electrical conduction between the loop wire 10 and the fixing screw 13 is achieved, while ensuring the insulation effect between the transmitting branch and the loop.

In one embodiment, as shown in Figure 4, the rear end of the front rod 4 is provided with a step hole at the end of the threaded hole for connecting the fixing screw 13, and a sealing gasket 12 is tightly fitted inside the step hole. The fixing screws 13 are coated with thread glue. In this embodiment, the sealing gasket 12 can improve the sealing effect, and the thread glue can improve the tightness.

In one embodiment, as shown in FIG. 4 , a plastic gasket is provided between the sealing gasket 12 and the fixing screw 13 . In this embodiment, the plastic gasket can prevent the sealing gasket 12 from being greatly deformed during the pushing and pulling process, thereby ensuring its sealing performance.

In one embodiment, the circuit connecting rod 16 and the drum spring 15 are connected by soldering. In this embodiment, the drum spring 15 can be made of brass, and soldering can ensure its connection strength and good electrical conductivity.

In one embodiment, as shown in Figures 1, 3 and 8, the electrical connector assembly 6 includes a first electrical connector 6-1 and a second electrical connector 6-2. The first electrical connector 6-1 The second electrical connector 6-2 is electrically connected to the loop connecting rod 16, and the second electrical connector 6-2 is electrically connected to the traction rope 11; the first electrical connector 6-1 is a spring pin, so that the loop connecting rod 16 is suitable for The electrical connection with the first electrical connector 6-1 is maintained during the sliding process back and forth. In this embodiment, the spring pin of the first electrical connector 6-1 can be made of brass and can be elastically expanded and contracted to ensure that the spring pin is always in contact with the loop connecting rod 16, thereby ensuring good electrical conductivity and not being fixed. The type connection also allows the loop connecting rod 16 to slide forward and backward while maintaining electrical performance, so as to facilitate the release and retraction of the snare wire 1.

In one embodiment, as shown in FIG. 8 , the end surface of the spring pin that contacts the loop connecting rod 16 is flat. In this embodiment, the contact between the flat surface of the end surface of the spring pin and the cylindrical surface of the loop connecting rod 16 is a line contact, which improves the conductive stability compared to point contact.

In one embodiment, the return electrode 2 and the return wire 10 are laser welded. In this embodiment, laser welding can ensure that the loop electrode 2 and the loop wire 10 are always in a conductive state, overcoming the current risk of poor contact that exists between the loop electrode and the loop wire through extrusion to form conduction.

In one embodiment, the usage process is as follows:

One end of the accessory connection line is connected to the electrical connector assembly 6, and the other end is connected to the plasma RF therapy device to obtain energy; when the snare wire 1 is passed through the handle 7 to take the lesion tissue and tighten it (while tightening, step on the cutting pedal) to output energy. , the current will flow from the second electrical connector 6-2 to the snare wire 1 via the traction rope 11, and then return to the first via the loop electrode 2, the loop wire 10, the fixing screw 13, the drum spring 15 and the loop connecting rod 16 after flowing through the diseased tissue. The electrical connector 6-1 forms a current loop. At the same time, the physiological saline will enter through the perfusion chamber interface 4-1, reach the snare wire 1 through the inner tube 8, and then flow out from the root of the snare wire 1, stimulating the plasma effect and retracting the snare wire 1 at the same time. Tight to achieve cutting of the diseased tissue. After the snare wire 1 has taken out the lesion tissue and retracted, the tip of the snare wire 1 can be placed in a position just exposing the outer sheath 3. This can make the loop electrode 2 more fully in contact with the target tissue during coagulation, thereby achieving rapid and effective treatment. Coagulation reduces patient risk while improving surgical efficiency. During the operation, if it is difficult to pull the ferrule due to the direction and angle of the ferrule, the handle 7 can be rotated to obtain an optimal angle.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims

An electric snare, which is characterized in that it includes an electrical joint assembly, a traction rope, a snare wire, a loop electrode, a loop wire, a fixing screw, a drum spring and a loop connecting rod that are electrically connected in sequence. The head of the loop electrode has a certain Radian; also includes a sheath assembly having a two-layer nesting structure, and the loop wire is sandwiched between the two-layer nesting structure of the sheath assembly.
The electric snare according to claim 1, characterized in that the head of the return electrode is spherical.
The electric snare according to claim 1, characterized in that the sheath assembly includes a concentric two-layer structure of an outer sheath and an inner sheath, and the outer sheath shrinks the loop wire through heat shrinkage. Clamped between the two layers.
The electric snare according to claim 3, characterized in that the traction rope is arranged along the axis of the outer sheath, and the space between the inner wall of the inner sheath and the traction rope forms a launch cavity.
The electric snare according to claim 3, characterized in that the inner diameter of the return electrode is smaller than the outer diameter of the inner sheath, and the inner sheath is inserted into the return electrode after being reduced in diameter by extrusion. The inner cavity is fixed, and a limit point is formed at the diameter reduction position. The limit point is suitable for blocking the connecting tube used to connect the snare wire and the traction rope from moving toward the mouth of the inner sheath.
The electric snare according to claim 3, characterized in that the loop electrode and the outer sheath are nested and connected through an inverted tooth-shaped structure.
The electric snare according to claim 3, characterized in that the rear end of the inner sheath is connected to a front rod, and a perfusion chamber interface is radially provided on the outer wall of the front rod, and the perfusion chamber interface faces Extends inward and is connected to the perfusion chamber, and the perfusion chamber is connected with the inner sheath.
The electric snare according to claim 7, characterized in that the fixing screw is rotatably embedded in the end sleeve, and the front rod and the fixing screw are fixed as one body.
The electric snare according to claim 8, characterized in that, one end of the circuit connecting rod is sleeved with a fixed drum spring and closely adheres to the inner wall of the end sleeve, and the elastic drum-shaped outer wall of the drum spring is in contact with the fixed drum spring. The screws are in close contact and are suitable for relative rotation.
The electric snare according to claim 8, characterized in that an insulating tube is nested in the inner hole of the fixing screw, and the circuit wire is squeezed between the fixing screw and the insulating tube.
The electric snare according to claim 7, characterized in that the rear end of the front rod is provided with a stepped hole at the end of the threaded hole for connecting the fixing screw, and a sealing gasket is tightly fitted inside the stepped hole. The fixing screws are coated with thread glue.
The electric snare according to claim 11, characterized in that a plastic gasket is provided between the sealing gasket and the fixing screw.
The electric snare according to claim 9, characterized in that the circuit connecting rod and the drum spring are connected by soldering.
The electric snare according to claim 1, wherein the electrical connector assembly includes a first electrical connector and a second electrical connector, the first electrical connector is electrically connected to the loop connecting rod, and the second electrical connector is electrically connected to the circuit connecting rod. The electrical connector is electrically connected to the traction rope; the first electrical connector is a spring pin, so that the loop connecting rod is adapted to maintain an electrical connection with the first electrical connector during sliding forward and backward.
The electric snare according to claim 14, characterized in that the end surface of the spring pin in contact with the circuit connecting rod is flat.
The electric snare according to claim 13, characterized in that the loop electrode and the loop wire are laser welded.