Medical ring-shaped combined knife

Abstract

The invention discloses a medical ring-shaped combined knife, which belongs to the technical field of medical instruments, and comprises an outer tube, a liquid injection joint, a handle, a slip ring, a ring sleeve and a traction piece, the liquid injection joint is arranged between the outer tube and the handle, a liquid injection channel is arranged on the liquid injection joint, a liquid injection cavity communicated with the liquid injection channel is formed in an inner cavity of the outer tube, the slip ring is slidably arranged on the handle, and the ring sleeve is arranged on the handle. The traction piece is slidably connected with the handle in a clamped and embedded mode, one end of the traction piece is fixedly connected with the sliding ring, the other end of the traction piece extends into the liquid injection cavity, the ring sleeve is fixedly connected with the end, away from the sliding ring, of the traction piece, and the ring sleeve comprises a cutting ring, a front throttling pipe and a rear throttling pipe, the front throttling pipe and the rear throttling pipe can stretch into the liquid injection cavity under traction of the traction piece, and liquid passing gaps are formed between the front throttling pipe and the outer pipe and between the rear throttling pipe and the outer pipe. According to the electric snare, the outer diameter of the outer tube is reduced, the electric snare can be controlled in a narrower cavity, preoperative and postoperative cleaning is facilitated, and the use experience of medical staff is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical instruments, in particular to a medical ring-shaped combined knife. Background Art

[0002] The electric snare is a medical device used in conjunction with an endoscope. It mainly uses high-frequency current to remove polyps or other excess tissues in the digestive tract. It generates heat through high-frequency current to achieve cutting and coagulation of target tissues. It is often used in digestive tract surgery. The operation of the electric snare needs to be combined with an endoscope. Under the guidance of the endoscope, polyps or other abnormal tissues in the digestive tract can be accurately located and treated.

[0003] At present, the working temperature of the cutting electric knife of the electric snare is usually 100-150℃, which is still a high temperature for human tissue and is easy to cause damage to human tissue when working for a long time; at the same time, the cutting electric knife will produce smoke when destroying tissue protein, which will affect the searchlight of the endoscope and thus affect the operation. In order to solve the above problems, electric snares that can spray water jets have gradually appeared on the market. The sprayed water jet acts on the tissue location to be cut or peeled to play a role in cooling and eliminating fog.

[0004] For example, the Chinese patent document with publication number CN213190042U discloses a medical ring-shaped combined knife, including a catheter part, a snare, a guide wire, a control part, and a needle seat; the catheter part is provided with a ring cavity and an injection cavity; the ring cavity is provided with a guide wire; the guide wire is connected to the snare, and the guide wire is directly or indirectly electrically connected to the energy supply platform; the needle seat is arranged on the outside of the catheter part, and the internal channel of the needle seat is connected to the injection cavity. When working, liquid is injected into the injection cavity through the internal channel of the needle seat, thereby eliminating smoke.

[0005] For another example, the Chinese patent document with publication number CN219000526U discloses a novel plasma bipolar snare, including a control handle, a pull ring is provided on one side of the control handle, a protective shell is fixedly connected to the other side of the control handle, an electrode connector is fixedly connected to the bottom end of the control handle, an outer tube is provided inside the protective shell, the other end of the outer tube extends to the outside of the protective shell, an injection tube and a connecting line are provided inside the outer tube, and a spraying mechanism is provided at one end of the injection tube. During operation, physiological saline is delivered to the cutting site using the injection port and the injection tube, so that the cutting snare can achieve plasma bipolar energization.

[0006] The snares disclosed in the above two patent documents both have the function of injecting liquid. However, for the technical solution of CN213190042U, the injection cavity for injecting liquid and the snare cavity with a wire inside are independent and isolated from each other, which increases the difficulty of producing the catheter part. At the same time, it also increases the outer diameter of the catheter part, which is not conducive to the smooth entry of the catheter part into the human digestive tract. For the technical solution of CN219000526U, a liquid injection tube is inserted into the inner part of the outer tube. Since the liquid injection tube and the outer tube form an inner and outer outer tube structure, the outer diameter of the outer tube will undoubtedly increase, resulting in an increase in the difficulty of the outer tube extending into the digestive tract and increasing the pain of the patient. Summary of the invention

[0007] The technical problem to be solved by the present invention is that in the prior art, the outer diameter of the portion of the snare with a liquid injection function that extends into the human digestive tract is relatively large, the processing difficulty is relatively large and it aggravates the patient's pain. Based on this, the present invention provides an electric snare with a liquid injection function and can achieve precise and flexible control in a narrow digestive tract without designing the outer diameter of the outer tube to be large enough.

[0008] The technical solution adopted by the present invention to solve its technical problems is: a medical ring-shaped combined knife, including an outer tube, an injection joint, a handle, a slip ring, a snare and a traction piece, the injection joint is arranged between the outer tube and the handle, the outer tube is fixed relative to the injection joint, the handle is rotatable relative to the injection joint, an injection channel is arranged on the injection joint, the inner cavity of the outer tube forms an injection cavity connected with the injection channel, the slip ring is slidably arranged on the handle, the traction piece and the handle are slidably engaged and connected, one end of the traction piece is fixedly connected to the slip ring, the other end of the traction piece extends into the injection cavity, the snare is fixedly connected to one end of the traction piece away from the slip ring, the snare includes a cutting ring and a front throttle tube and a rear throttle tube connected at both ends of the cutting ring, the front throttle tube and the rear throttle tube can be extended into the injection cavity under the traction of the traction piece, and a liquid gap is formed between the front throttle tube and the rear throttle tube and the outer tube.

[0009] Furthermore, the handle is provided with a limit head, which is rotatable relative to the injection joint, the traction member is slidably engaged and connected to the limit head, and a limit member is fixedly provided on the outside of the traction member. Moving the traction member can separate or abut the limit member and the limit head. When the two are separated, the electric snare has a first state in which the front throttle tube and the rear throttle tube are both located inside the outer tube. When the two are abutted, the electric snare has a second state in which the front throttle tube is located outside the outer tube and the rear throttle tube is located inside the front end of the outer tube.

[0010] Furthermore, the traction part includes a steel wire rope and a booster tube connected to each other. The steel wire rope is located in the injection cavity and is fixedly connected to the snare. The booster tube is made of a hard material and is slidably engaged with the limit head. One end of the booster tube is fixedly connected to the slip ring. The limiter is a tubular structure fixedly sleeved on the outside of the booster tube.

[0011] Furthermore, the end of the injection joint is recessed to form an installation groove, the limit head is rotatably installed in the installation groove, a sealing groove is opened on the bottom wall of the installation groove, a sealing member is installed in the sealing groove, the booster tube can slidably pass through the sealing member, and the sealing member and the booster tube are sealed and connected, and the sealing member blocks one end of the injection channel.

[0012] Furthermore, the outer tube is a circular plastic hose, the front throttle tube and the rear throttle tube are both cylindrical structures and have an outer diameter smaller than the inner diameter of the outer tube, and the liquid gap is composed of the gap between the outer wall of the front throttle tube and the wall of the injection chamber and the gap between the rear throttle tube and the wall of the injection chamber.

[0013] Furthermore, a positioning pin is fixedly mounted on the front end of the front throttle tube.

[0014] Furthermore, one side of the slip ring protrudes outward to form an electrode mounting portion, a base is fixedly mounted in the electrode mounting portion, an electrode is mounted on the base, and the electrode is electrically connected to the traction member.

[0015] Furthermore, a socket for inserting the rear end of the traction member is provided on the base, the bottom of the electrode is threadedly connected to the base, and the lower end of the electrode extends into the socket and abuts against the traction member.

[0016] Furthermore, a nut is mounted on the front end of the liquid injection connector, the front end of the nut is opened, and the rear end of the outer tube passes through the front end of the nut and is squeezed and fixed between the nut and the liquid injection connector.

[0017] The beneficial effects of the present invention are as follows: the electric snare of the present invention enables the inner cavity of the outer tube to form an injection cavity for liquid injection, and the traction member extends into the injection cavity, which greatly reduces the outer diameter of the outer tube, can be accurately and flexibly manipulated in a narrower cavity, is easy to process, and at the same time alleviates the patient's pain, and can efficiently remove the heat transferred to the traction member when the snare is working, which is beneficial to further improve the cooling effect. In addition, the front throttle tube and the rear throttle tube reduce the flow area of ​​the injected liquid, so that the liquid passing through the liquid gap can be sprayed on the cutting part in the form of a straight water column at a certain flow rate, which is beneficial to preoperative and postoperative cleaning, thereby shortening the operation time and greatly improving the use experience of medical staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 is a schematic structural diagram of the electric snare of the present invention;

[0020] Figure 2 yes Figure 1 A partial enlarged view of the electric snare at point A shown;

[0021] Figure 3 yes Figure 1 A partial enlarged view of the electric snare at point B shown;

[0022] Figure 4 yes Figure 1 A schematic diagram of the connection structure between the snare and the outer tube in the electric snare device shown;

[0023] Figure 5 yes Figure 1 A partial enlarged view of point C in the electric snare shown.

[0024] In the figure: 1, outer tube, 11, injection chamber, 2, injection joint, 21, injection channel, 22, mounting groove, 23, sealing groove, 24, sealing member, 25, injection port, 3, handle, 31, limit head, 311, perforation, 4, slip ring, 41, electrode mounting portion, 42, base, 421, jack, 43, electrode, 5, snare, 51, cutting ring, 52, front throttle tube, 53, rear throttle tube, 54, liquid gap, 55, positioning needle, 6, traction member, 61, limit member, 62, wire rope, 63, booster tube, 7, nut, 8, sheath tube. DETAILED DESCRIPTION

[0025] The present invention will now be described in detail with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, and therefore only shows the components related to the present invention.

[0026] See also Figure 1-Figure 5 The present invention provides a medical ring-shaped combined knife, which combines the two functions of cleaning and cutting. The medical ring-shaped combined knife includes an outer tube 1, a liquid injection joint 2, a handle 3, a slip ring 4, a snare 5 and a traction member 6. The liquid injection joint 2 is connected between the outer tube 1 and the handle 3. The outer tube 1 is fixed relative to the liquid injection joint 2. The handle 3 is rotatable relative to the liquid injection joint 2. The liquid injection joint 2 is provided with a liquid injection channel 21. The liquid injection channel 21 runs through the front and rear ends of the liquid injection joint 2. The inner cavity of the outer tube 1 forms a liquid injection cavity 11 connected to the liquid injection channel 21. The slip ring 4 is slidable. The traction member 6 is arranged on the handle 3, and the traction member 6 is slidably engaged with the handle 3, one end of the traction member 6 is fixedly connected with the slip ring 4, and the other end of the traction member 6 extends into the liquid injection cavity 11, and the snare 5 is fixedly connected with the end of the traction member 6 away from the slip ring 4. The snare 5 includes a cutting ring 51 and a front throttle tube 52 and a rear throttle tube 53 connected to both ends of the cutting ring 51. The front throttle tube 52 and the rear throttle tube 53 can be pulled by the traction member 6 and extend into the liquid injection cavity 11, and the front throttle tube 52 and the rear throttle tube 53 form a liquid gap 54 with the outer tube 1. The above-mentioned "slidably engaged" means that the traction member 6 can slide along the axial direction of the handle 3, but cannot rotate relative to the handle 3, and when the handle 3 rotates, the traction member 6 can be driven to rotate synchronously.

[0027] When the electric snare of the present invention is used, before being inserted into the human digestive tract, the cutting ring 51, the front throttle tube 52 and the rear throttle tube 53 are all accommodated in the front end of the injection cavity 11 (i.e., the end of the injection cavity 11 away from the handle 3), so that the front end of the outer tube 1 can enter the digestive tract. When the medical staff inserts the outer tube 1 into the part to be cut, if bleeding occurs in the part, in order to avoid affecting the operation, physiological saline can be injected into the injection cavity 11 through the injection channel 21, and then flow out through the liquid gap 54 to clean the tissue to be cut. After cleaning, push the slip ring 4 forward to drive the traction member 6 and the snare 5 to move forward, and finally make the cutting ring 51 extend to the outside of the outer tube 1 and open, and then the cutting ring 51 is wrapped around the tissue to be cut. Then, pull the slip ring 4 backward to make the cutting ring 51 tighten the tissue to be cut, and at the same time, burn and cut the tissue under the action of heat generated by the high-frequency current. When the burning produces smoke, the cutting can be suspended, and then physiological saline can be injected into the injection cavity 11 through the injection channel 21, and finally act on the cutting part, which can cool down the temperature and eliminate the smoke, so as to continue the cutting operation. The electric cutting and cleaning processes are intermittent, that is, when one of them is working, the other is suspended. It should be noted that before cutting, the medical staff can rotate the handle 3 relative to the injection connector 2 to adjust the angle of the cutting ring 51 so as to cover the tissue to be cut. When the handle 3 rotates, the injection connector 2 and the outer tube 1 do not rotate, which avoids the friction of the outer tube 1 on the patient's digestive cavity when it rotates, and also ensures that the water injection part on the injection connector 2 will not move, which reduces the patient's pain and improves the user experience of medical staff.

[0028] The electric snare of the present invention forms an injection cavity 11 for liquid injection in the inner cavity of the outer tube 1, and the traction member 6 extends into the injection cavity 11. Compared with the prior art method of independently separating the snare cavity and the injection cavity and inserting the injection tube separately in the outer tube, the present invention greatly reduces the outer diameter of the outer tube, and can be accurately and flexibly controlled in a narrower cavity, while reducing the pain of the patient. In addition, before cutting, the front throttle tube 52 is located in the front end of the outer tube 1, and the front throttle tube 52 limits the flow area of ​​the injected liquid, so that the liquid passing through the liquid gap 54 can be sprayed at the to-be-cut part in the form of a straight water column at a certain flow rate, which is conducive to preoperative cleaning, and during the cutting operation, the rear throttle tube 53 is located in the front end of the outer tube 1, and at this time, the liquid flowing out through the liquid gap 54 can also be sprayed at the cutting part at a certain flow rate to play a cooling and defogging role. In this way, the cutting part before and after the electric cutting can be cleaned by the same instrument, saving operation time. Furthermore, during the injection, the physiological saline flows directly through the traction member 6, which can timely remove the heat transferred to the traction member 6 when the snare 5 is working, which is conducive to further improving the cooling effect. At the same time, since the size of the liquid gap 54 is much smaller than the size of the front throttle tube 52 and the rear throttle tube 53, the front throttle tube 52 and the rear throttle tube 53 can play a certain guiding role on the cutting ring 51 when moving in the injection cavity 11, which can prevent the cutting ring 51 from being excessively deviated when the traction member 6 moves in the outer tube 1, which helps medical staff to accurately control.

[0029] See also Figure 2 As a preferred embodiment, the handle 3 has a limit head 31, the limit head 31 is rotatable relative to the injection connector 2, the traction member 6 is slidably engaged and connected to the limit head 31, and the limit member 61 is fixedly arranged outside the traction member 6. The moving traction member 6 can drive the limit member 61 to move so that the limit member 61 is separated from or abutted against the limit head 31. When the limit member 61 is separated from the limit head 3, the electric snare has a first state in which the front throttle tube 52 and the rear throttle tube 53 are both located in the outer tube 1. When the limit member 61 abuts against the limit head 31, the electric snare has a second state in which the front throttle tube 52 is located outside the outer tube 1 and the rear throttle tube 53 is located inside the front end of the outer tube 1 (see Figure 5 In the first state, the snare 5 is completely contained in the outer tube 1, and the outer tube 1 can provide good protection for the snare 5. When the slip ring 4 slides forward, the traction member 6 and the limit member 61 can be driven to move. When the limit member 61 abuts against the limit head 31, the snare 5 moves into place. At this time, the snare 5 is completely extended to the outside of the outer tube 1 and is in an open state, which is conducive to the medical staff to quickly move the snare 5 into place.

[0030] The traction member 6 includes a steel wire rope 62 and a booster tube 63 which are connected to each other. The steel wire rope 62 is located in the injection cavity 11 and is fixedly connected to the snare 5. The booster tube 63 is made of a hard material and is slidably engaged with the limit head 31. One end of the booster tube 63 is fixedly connected to the slip ring 4. The limiter 62 is a tubular structure fixedly sleeved on the outside of the booster tube 63. The steel wire rope 62 has certain elasticity and toughness, and is relatively soft, which is conducive to extending into the human digestive tract. The booster tube 63 is made of a hard material, which ensures that the structure of the booster tube 63 does not deform, which is conducive to the stable movement of the booster tube 63. In this embodiment, the limiter 62 is a stainless steel tube. In other embodiments, the limiter 62 can also be a supporting flange protruding from the outside of the booster tube 63.

[0031] Furthermore, the stopper head 31 is provided with a through hole 311, and the booster tube 63 is slidably engaged with the through hole 311. The cross section of the through hole 311 is non-circular, and the booster tube 63 cooperates with the through hole 311, so that the booster tube 63 can only slide along the through hole 311, but cannot rotate relative to the stopper head 31. It can be understood that the through hole 311 is an elliptical hole or a square hole or other irregular polygonal hole, which is not limited here.

[0032] As a preferred embodiment, the end of the injection joint 2 is recessed to form a mounting groove 22, and the limit head 31 is rotatably mounted in the mounting groove 22. A sealing groove 23 is provided on the bottom wall of the mounting groove 22, and a sealing member 24 is installed in the sealing groove 23. The booster tube 63 can slide through the sealing member 24, and the sealing member 24 is sealed and connected to the booster tube 63, and the sealing member 24 blocks one end of the injection channel 21. By providing the sealing member 24, the liquid in the injection channel 21 is effectively prevented from flowing backward into the handle 3, thereby avoiding leakage. The sealing member 24 can be made of silicone or rubber material, which is not limited here. Furthermore, a liquid injection port 25 is provided on the side of the injection joint 2, and the liquid injection port 25 is connected to the injection channel 21. The liquid injection port 25 is used to connect with a liquid supply device (for example, a syringe) to achieve liquid injection in the injection channel 21.

[0033] See also Figure 3 In this embodiment, the slip ring 4 and the handle 3 are slidably connected by means of mutually cooperating sliding grooves and convex block structures, so that the slip ring 4 can slide along the length direction of the handle 3. One side of the slip ring 4 protrudes outward to form an electrode mounting portion 41, and a base 42 is fixedly mounted in the electrode mounting portion 41. An electrode 43 is mounted on the base 42. The electrode 43 is connected to the traction member 6 by wires, and the electrode 43 is externally connected to a power supply device to supply power to the snare 5 through the traction member 6.

[0034] As a preferred embodiment, the base 42 is provided with a socket 421 for inserting the rear end of the traction member 6, the bottom of the electrode 43 is threadedly connected to the base 42, and the lower end of the electrode 43 extends into the socket 421 and abuts against the traction member 6. During installation, the electrode 43 is screwed into the base 42 until the electrode 43 presses and fixes one end of the traction member 6 on the hole wall of the socket 421. At this time, the traction member 6 is fixedly connected to the base 42, and at the same time, the electrode 43 and the traction member 6 are electrically connected, which is simple and convenient to operate, and greatly improves the assembly efficiency.

[0035] See also Figure 5 The outer tube 1 is a circular plastic hose. The front throttle tube 52 and the rear throttle tube 53 are both cylindrical structures and their outer diameters are smaller than the inner diameter of the outer tube 1 to ensure that the front throttle tube 52 and the rear throttle tube 53 can move in the injection cavity 11. The liquid gap 54 is composed of the gap between the outer wall of the front throttle tube 52 and the cavity wall of the injection cavity 11 and the gap between the rear throttle tube 53 and the cavity wall of the injection cavity 11. In the present embodiment, the outer diameters of the front throttle tube 52 and the rear throttle tube 53 are smaller than the inner diameter of the outer tube 1, ensuring that the front throttle tube 52 and the rear throttle tube 53 can move in the outer tube 1 and that the liquid gap 54 is formed. In other embodiments not shown, the outer diameters of the front throttle tube 52 and the rear throttle tube 53 match the inner diameter of the outer tube 1, and the outer walls of the front throttle tube 52 and the rear throttle tube 53 are slidably connected to the inner wall of the outer tube 1. At this time, a plurality of grooves are axially opened on the outer walls of the front throttle tube 52 and the rear throttle tube 53, and the two ends of the grooves pass through the opposite end walls of the throttle tube, and the grooves form the liquid gap 54, thereby ensuring that the front throttle tube 52 and the rear throttle tube 53 can slide more stably in the outer tube 1.

[0036] In this embodiment, the rear throttle tube 53 is fixedly sleeved on the front end of the traction member 6, and one end of the cutting ferrule 51 is fixedly connected to the traction member 6. In other embodiments, one end of the rear throttle tube 53 is fixedly connected to the cutting ferrule 51, and the front end of the traction member 6 is fixedly connected to the other end of the rear throttle tube 53.

[0037] As a preferred embodiment, a positioning pin 55 is fixedly installed at the front end of the front throttle tube 52. The positioning pin 55 is a cylindrical structure. The positioning pin 55 is used to mark and locate the part to be cut before electrocuting, making the operation more accurate and convenient. During the specific operation, the slip ring 4 is pushed forward to expose the positioning pin 55 to the outside of the outer tube 1 to mark and locate the part to be cut.

[0038] See also Figure 1 , Figure 4The front end of the injection joint 2 is provided with a nut 7, and the front end of the nut 7 is provided with an opening. The rear end of the outer tube 1 passes through the front end of the nut 7 and is squeezed and fixed between the nut 7 and the injection joint 2, thereby realizing the fixed connection between the outer tube 1 and the injection joint 2. Specifically, the front end of the injection joint 2 is provided with a conical structure, and the rear end of the outer tube 1 is provided with a flared structure that matches the conical structure. During assembly, the nut 7 is rotated, and the nut 7 can squeeze and fix the flared structure on the conical structure. In addition, since the outer tube 1 is a hose structure, it can be deformed to a certain extent when being squeezed, so that the seal between the outer tube 1 and the injection joint 2 is ensured. Further, the rear end of the outer tube 1 is fixedly provided with a sheath tube 8, and the rear end of the sheath tube 8 passes through the front end opening of the nut 7 and is squeezed and fixed between the nut 7 and the outer tube 1. By providing the sheath tube 8, the structural strength of the connection position between the outer tube 1 and the nut 7 is improved, and excessive bending and deformation of the connection between the outer tube 1 and the nut 7 is avoided, and deformation and damage of the rear end of the outer tube 1 are prevented.

[0039] The electric snare of the present invention forms an injection cavity 11 for liquid injection in the inner cavity of the outer tube 1, and the traction member 6 extends into the injection cavity 11, which greatly reduces the outer diameter of the outer tube. It can be accurately and flexibly controlled in a narrower cavity, which is convenient for processing and relieves the pain of the patient. It can also efficiently remove the heat transferred to the traction member 6 when the snare 5 is working, which is beneficial to further improve the cooling effect. In addition, the front throttle tube 52 and the rear throttle tube 53 reduce the flow area of ​​the injected liquid, so that the liquid passing through the liquid gap 54 can be sprayed on the cutting part in the form of a straight water column at a certain flow rate, which is beneficial to preoperative and postoperative cleaning, thereby shortening the operation time and greatly improving the user experience of medical staff.

[0040] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the scope of the present invention through the above description. The technical scope of this invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A medical ring-shaped combined knife, characterized in that: The invention comprises an outer tube, an injection joint, a handle, a slip ring, a snare and a traction piece. The injection joint is arranged between the outer tube and the handle. The outer tube is fixed relative to the injection joint, and the handle is rotatable relative to the injection joint. An injection channel is arranged on the injection joint. The inner cavity of the outer tube forms an injection cavity connected with the injection channel. The slip ring is slidably arranged on the handle. The traction piece and the handle are slidably engaged and connected. One end of the traction piece is fixedly connected to the slip ring, and the other end of the traction piece extends into the injection cavity. The snare is fixedly connected to one end of the traction piece away from the slip ring. The snare comprises a cutting ring and a front throttle tube and a rear throttle tube connected at both ends of the cutting ring. The front throttle tube and the rear throttle tube can extend into the injection cavity under the traction of the traction piece, and a liquid gap is formed between the front throttle tube and the rear throttle tube and the outer tube.

2. The electric snare according to claim 1, characterized in that: The handle is provided with a limit head, which is rotatable relative to the injection joint, and the traction member is slidably engaged and connected to the limit head. The outside of the traction member is fixedly provided with a limit member, and moving the traction member can separate or abut the limit member and the limit head. When the two are separated, the electric snare has a first state in which the front throttle tube and the rear throttle tube are both located inside the outer tube. When the two are abutted, the electric snare has a second state in which the front throttle tube is located outside the outer tube and the rear throttle tube is located inside the front end of the outer tube.

3. The electric snare as claimed in claim 2, characterized in that: The traction part includes a steel wire rope and a booster tube which are connected to each other. The steel wire rope is located in the injection cavity and is fixedly connected to the snare. The booster tube is made of hard material and is slidably engaged with the limit head. One end of the booster tube is fixedly connected to the slip ring. The limiter is a tubular structure fixedly sleeved on the outside of the booster tube.

4. The electric snare as claimed in claim 4, characterized in that: The end of the injection joint is recessed to form an installation groove, the limit head can be rotatably installed in the installation groove, the bottom wall of the installation groove is provided with a sealing groove, a sealing member is installed in the sealing groove, the booster tube can slidably pass through the sealing member, and the sealing member and the booster tube are sealed and connected, and the sealing member blocks one end of the injection channel.

5. The electric snare according to claim 1, characterized in that: The outer tube is a circular plastic hose. The front throttle tube and the rear throttle tube are both cylindrical structures with an outer diameter smaller than the inner diameter of the outer tube. The liquid gap is composed of the gap between the outer wall of the front throttle tube and the wall of the injection cavity and the gap between the rear throttle tube and the wall of the injection cavity.

6. The electric snare according to claim 5, characterized in that: A positioning pin is fixedly installed at the front end of the front throttle tube.

7. The electric snare as claimed in claim 1, characterized in that: One side of the slip ring protrudes outward to form an electrode mounting portion, a base is fixedly mounted in the electrode mounting portion, an electrode is mounted on the base, and the electrode is electrically connected to the traction member.

8. The electric snare according to claim 7, characterized in that: The base is provided with a socket for inserting the rear end of the traction member, the bottom of the electrode is threadedly connected with the base, and the lower end of the electrode extends into the socket and abuts against the traction member.

9. The electric snare according to claim 1, characterized in that: The front end of the liquid injection joint is sleeved with a nut, the front end of the nut is opened, and the rear end of the outer tube passes through the front end of the nut and is squeezed and fixed between the nut and the liquid injection joint.

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