A snare with an injection needle

Abstract

This invention discloses a snare device with an injection needle, relating to the field of medical supplies technology. It includes a fixing tube with a first buckle at one end and a sliding groove on the front side. A sliding connector is located inside the fixing tube, with one end extending through the groove to the outside of the fixing tube. A blocking mechanism is located on the outer wall of the fixing tube near the first buckle. The blocking mechanism includes a pressure roller for pushing back the medication after injection to reduce injection pressure, and a pressing plate for moving the operating components. This invention achieves localized compression of the infusion tubing after injection, combined with axial pushing to generate a backflow effect, recovering residual medication from the needle tip into the infusion tubing, reducing residual pressure, preventing liquid splashing upon needle withdrawal, improving surgical field clarity, and preventing excessively slippery tissue surfaces. It has the advantages of preventing needle splashing during withdrawal and controllable injection depth.

Description

Technical Field

[0001] This invention relates to the field of medical supplies technology, specifically to a snare device with an injection needle. Background Technology

[0002] With the development of endoscopic minimally invasive technology, polyp removal has become one of the main treatment methods for common diseases of the digestive tract. In clinical practice, a snare is usually used to snare the lesion tissue and then combined with high-frequency electrocautery to complete the removal operation. In actual surgery, in order to reduce the risk of perforation and improve the success rate of snare removal, it is often necessary to inject physiological saline into the submucosa of the polyp or lesion before removal to make the tissue bulge locally, thereby forming a safe buffer layer and improving the operating space. Therefore, in clinical practice, it is usually necessary to first use an injection needle to complete the injection operation, and then change to a snare for snare removal.

[0003] However, in existing technologies, the injection needle and snare are mostly separate structures, which have significant shortcomings in actual operation: On the one hand, the instrument replacement process is cumbersome, which not only prolongs the operation time but also increases the complexity of the operation and the risk of positioning deviation; on the other hand, when the injection needle is withdrawn after the injection, the residual pressure inside the infusion tube and needle can easily cause liquid splashing or droplets to adhere to the tissue surface at the moment the needle withdraws from the tissue, making the surface of the lesion area slippery, thus affecting the gripping stability of the snare and even causing snare failure; in addition, traditional injection devices usually lack an effective pressure relief structure, making it difficult to adjust the internal pressure before needle withdrawal, and also lack precise control over the injection depth, which can easily lead to problems of piercing too deeply or too shallowly, affecting the safety and effectiveness of the operation.

[0004] Therefore, there is an urgent need to provide a device that integrates injection and snare functions, has the ability to prevent splashing during needle withdrawal, and enables controllable injection depth, in order to solve the problems of cumbersome operation, liquid splashing, and insufficient control precision in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a snare device with an injection needle to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a snare with an injection needle, comprising a fixing tube, one end of which is provided with an operating handle for easy hand support and positioning by the operator, a sliding groove is provided on the front side of the fixing tube, and a sliding connector is provided inside the fixing tube, one end of which extends to the outside of the fixing tube through the sliding groove. The operating handle includes a first buckle fixed to the far end of the fixed tube, and two second buckles connected to the sliding connector via a slide tube, for realizing the linkage control between external drive and internal structure; the first buckle and the two second buckles form a triangular hole for the user to hold with three fingers, thereby improving hand stability and operating accuracy; A connector is provided on the side of the fixed tube away from the first buckle. A support tube is connected inside the connector. One end of the support tube extends away from the fixed tube. A tube sheath is provided inside the support tube. The support tube is used to provide support for the side of the tube sheath close to the fixed tube, to prevent the tube sheath from bending, and to improve the overall rigidity and guiding stability. The outer wall of one end of the tube sheath is connected to the inner wall of the connector. The sheath is equipped with operating components for injecting medication and snare polyps, enabling integrated operation. A blocking mechanism is provided on the outer wall of the fixed tube near the first buckle. The blocking mechanism includes a pressure roller and a pressing plate. The pressure roller is used to press the infusion tube and push back the drug solution after the drug injection is completed, thereby reducing the residual injection pressure. The pressing plate is used to push the operating component to move, thereby adjusting the drug injection depth and controlling the needle advance and retreat.

[0007] According to the above technical solution, both the first buckle and the sliding connector are circular ring structures, which is beneficial for uniform force distribution and coaxial movement. The slide cylinder is used to support the two second buckles to slide stably on the outer wall of the fixed tube. The slide cylinder is a cylindrical structure, and its inner wall contacts the outer wall of the fixed tube to form a guiding fit. At the same time, the inner wall of the slide cylinder and the sliding connector extend to one end of the outer side of the fixed tube and are fixedly connected, so that when the second buckle is pushed, the sliding connector can be driven to move synchronously to realize power transmission.

[0008] According to the above technical solution, the inner wall of one side of the connector is fixedly connected to the outer wall of the fixed tube, and the inner wall of the side of the connector away from the fixed tube is fixedly connected to the outer wall of the support tube. The support tube is made of elastic rubber material, which is used to provide buffer support while separating the tube sheath and the connector, reducing the wear of the tube sheath during the movement, improving service life and smooth operation.

[0009] According to the above technical solution, the operating components include an infusion tube and a cutting wire. The infusion tube is located inside the sheath and is used to deliver the medication. One end of the infusion tube extends to the distal end of the sheath and is fixedly connected to a needle for precise injection into the patient's tissue. One side of the cutting wire extends through the inside of the sheath to the distal end and forms a sliding knot structure. The other side is connected to an electrode set on the outer wall of the sliding tube. The electrode is used to connect to an external power source, thereby electro-removing the polyp through the cutting wire, realizing the integration of injection and resection functions.

[0010] According to the above technical solution, the other end of the infusion tube passes through the pressure pad and extends to the outside of the fixed tube through the sliding groove on the lower side of the pressure roller and the side wall of the fixed tube, which facilitates connection with the external infusion supply device. The outer wall of the infusion tube is fixedly connected to the inner wall of the pressure pad, so that the pressure pad can directly drive the infusion tube to move axially when it is pressed, thereby driving the needle to move forward and backward synchronously and realizing the adjustment of the injection depth.

[0011] According to the above technical solution, the blocking mechanism further includes a stabilizing cylinder and a limiting tube. One end of the limiting tube is fixedly connected to the outer wall of the sliding connector. The stabilizing cylinder is sleeved on the outside of the limiting tube and fixedly connected to the pressing plate, which is used to provide stable guidance and limit displacement during the pressing process. The pressing plate is connected to the sliding connector through a first spring, so as to achieve automatic reset after release and improve the continuity of operation.

[0012] According to the above technical solution, the pressing pad is located inside the fixed tube and is fixedly connected to the infusion tube. The outer part is for the operator to press, and a support plate is provided on its outer wall. The support plate contacts the outer wall of the fixed tube to provide support and guidance for the pressing pad, so as to avoid swaying during the pressing process and improve the stability of movement.

[0013] According to the above technical solution, the inner side of the pressing plate has a circular structure and is coaxially arranged with the sliding connector, the connector head and the tube holder, so that the thrust is stably transmitted to the tube sheath along the axial direction, thereby ensuring that the needle advance and retreat process is smooth and controllable.

[0014] According to the above technical solution, the fixed tube is provided with an installation port on the side near the first buckle, and is provided with a limiting frame and an elliptical groove opened on the limiting frame. The rotating rod is inserted into the elliptical groove and fixedly connected to the middle of the pressure roller. The second spring provides support force so that the pressure roller is always located on the upper side of the infusion tube, so that the infusion tube can be pressed when needed to realize the functions of liquid blocking and backflow.

[0015] According to the above technical solution, the outer end of the rotating rod is provided with a hexagonal groove to facilitate connection with external tools or testing devices, and the outer wall of the pressure roller is provided with an annular groove to increase the friction between the roller and the outer wall of the infusion tube, thereby improving the pressing effect and pressure discharge efficiency.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: By incorporating a pressing pad, an infusion tube, and a first spring, the needle can be driven to quickly retract into the sheath after the drug injection is completed, forming a covered needle withdrawal path. This avoids the retention and ejection of liquid droplets during manual needle removal, effectively reducing the probability of the tissue surface being lubricated by liquid, thereby improving the stability of the subsequent snare. By incorporating a sliding connector, a sliding cylinder, a second buckle, and a cutting wire, stable force transmission and coaxial guidance can be achieved during the tightening process of the snare, ensuring uniform tightening of the sliding knot and reliable force application. This prevents deviation or slippage during the snare process, thereby improving the success rate of polyp removal and the accuracy of excision. By incorporating a pressure roller, a rotating rod, and a second spring, the infusion tubing can be locally compressed after injection and, in conjunction with axial pushing, generate a backflow effect, recovering the residual medication inside the needle into the infusion tubing, reducing residual pressure inside the tubing, preventing liquid splashing at the moment of needle removal, improving the clarity of the surgical field, and avoiding excessively slippery tissue surfaces. By incorporating a rotating rod and an external angle encoder, the axial displacement of the infusion tubing and needle can be converted into a detectable signal, enabling real-time monitoring and precise control of the injection depth. This avoids tissue damage or poor injection results caused by improper insertion depth, thereby improving operational safety and consistency. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is an enlarged structural diagram of one end of the sheath of the present invention; Figure 3 This is a schematic diagram of the disassembled structure of the present invention; Figure 4 This is a schematic diagram of the internal structure of the fixed tube of the present invention; Figure 5 This is a schematic diagram of a portion of the blocking mechanism of the present invention; Figure 6 This is a schematic diagram of the disassembled structure of the blocking mechanism of the present invention; Figure 7 This is a schematic diagram of the internal structure of the slide tube of the present invention; Figure 8 This is an enlarged structural schematic diagram of the blocking mechanism of the present invention; In the diagram: 1. Fixed tube; 2. First buckle; 3. Sliding connector; 4. Slide cylinder; 5. Second buckle; 6. Connector; 7. Support tube; 8. Tube sheath; 9. Infusion tube; 10. Needle; 11. Cutting wire; 12. Electrode; 13. Blocking mechanism; 301. Stabilizing cylinder; 302. Pressing plate; 303. First spring; 304. Support plate; 305. Limiting frame; 306. Rotating rod; 307. Pressure roller; 308. Second spring; 309. Limiting tube. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Please refer to Figure 1-6 The present invention provides a technical solution: a snare with an injection needle, comprising a fixed tube 1, a first buckle 2 at one end of the fixed tube 1, a sliding groove on the front side of the fixed tube 1, a sliding connector 3 inside the fixed tube 1, one end of the sliding connector 3 extending through the sliding groove to the outside of the fixed tube 1 and connected to a sliding cylinder 4 and two second buckles 5, the first buckle 2 and the two second buckles 5 forming a three-finger grip structure, the sliding cylinder 4 being sleeved on the outer wall of the fixed tube 1 and fixedly connected to the sliding connector 3, used to drive the sliding connector 3 to move axially; a connector 6 is provided on the side of the fixed tube 1 away from the first buckle 2, the inner wall of one side of the connector 6 being fixedly connected to the outer wall of the fixed tube 1, and the inner wall of the side of the connector 6 away from the fixed tube 1 being fixedly connected to the outer wall of a support tube 7, the support tube 7 being made of elastic rubber material, used to separate the tube sheath 8 and the connector 6; a tube sheath 8 is provided inside the support tube 7, and an operating component is provided inside the tube sheath 8, the operating component including an infusion tube 9 and a mounting tube 8. A needle 10 is attached to one end of an infusion tube 9, and a cutting wire 11 is used for snare removal. The infusion tube 9 is located inside a sheath 8, with one end extending to the side of the sheath 8 away from the fixing tube 1 and fixedly connected to the needle 10. The cutting wire 11 passes through the sheath 8 and extends to the distal end to form a sliding knot, with its other end connected to an electrode 12 disposed on the outer wall of the sliding cylinder 4. A blocking mechanism 13 is disposed on the outer wall of the fixing tube 1 near the first buckle 2, and the blocking mechanism 13 includes a pressure roller 30. 7 and the pressure plate 302, the infusion tube 9 passes through the blocking mechanism 13 and is connected to the pressure plate 302; the other end of the infusion tube 9 passes through the pressure plate 302 and extends to the outside of the fixed tube 1 through the groove on the lower side of the pressure roller 307 and the side wall of the fixed tube 1; the infusion tube 9 is fixedly connected to the pressure plate 302 and moves axially synchronously with the pressure plate 302 to drive the needle 10 to extend or retract; the pressure plate 302 is used to drive the infusion tube 9 to move axially to drive the needle 10 to extend or retract; This embodiment mainly realizes the rapid retraction of the needle after the snare injects the medicine, thereby avoiding liquid splashing during the needle withdrawal process. The fixed tube 1 serves as the overall holding base, with a first buckle 2 at one end. A sliding groove extending axially is opened on the front side of the fixed tube 1. A sliding connector 3 is coaxially arranged inside the fixed tube 1. One end of the sliding connector 3 extends to the outside of the fixed tube 1 through the sliding groove and is fixedly connected to a sliding cylinder 4. Two second buckles 5 are arranged on the outside of the sliding cylinder 4. The first buckle 2 and the two second buckles 5 together form a three-finger grip structure. The first buckle 2 is for the thumb to abut, and the two second buckles 5 are for the index and middle fingers to hold, forming a stable triangular force fulcrum. The reason for using a three-finger grip instead of a single-hand grip is that in minimally invasive surgery, the operator needs to control the needle advance and retreat, snare tightening and electrocautery at the same time. The three-finger structure can assign different functions to different fingers, avoid operational interference, and improve hand stability and operational accuracy. A connector 6 is provided on the side of the fixed tube 1 away from the first buckle 2. The inner wall of one side of the connector 6 is fixedly connected to the outer wall of the fixed tube 1. A support tube 7 is fixedly connected to the inner wall of the side of the connector 6 away from the fixed tube 1. The support tube 7 is made of elastic rubber material and has a tube sheath 8 inside. The function of the support tube 7 is to: firstly, separate the tube sheath 8 from the connector 6 to reduce the wear of the tube sheath 8 during movement; secondly, provide elastic buffer support for the side of the tube sheath 8 close to the fixed tube 1 to prevent the tube sheath 8 from bending under force, thereby improving the overall rigidity and guiding stability. An operating assembly is provided inside the sheath 8. The operating assembly includes an infusion tube 9 and a needle 10 located at one end of the infusion tube 9, as well as a cutting wire 11 for snare resection. The infusion tube 9 is located inside the sheath 8, with one end extending to the side of the sheath 8 away from the fixed tube 1 and fixedly connected to the needle 10 for delivering medication to the patient's lesion tissue. The cutting wire 11 passes through the inside of the sheath 8 and extends to the distal end to form a sliding knot structure. Its other end is connected to an electrode 12 located on the outer wall of the sliding cylinder 4. The electrode 12 is used to connect to an external high-frequency power supply, thereby electroresecting the polyp through the cutting wire 11. A blocking mechanism 13 is provided on the outer wall of the fixed tube 1 near the first buckle 2. The blocking mechanism 13 includes a pressure roller 307 and a pressing plate 302. The other end of the infusion tube 9 passes through the pressing plate 302 and is fixedly connected to it. Then, the infusion tube 9 extends to the outside of the fixed tube 1 through the sliding groove on the lower side of the pressure roller 307 and the side wall of the fixed tube 1, which facilitates connection with an external infusion supply device. The pressing plate 302 forms a telescopic linkage structure with the limiting tube 309 through the stabilizing cylinder 301. One end of the limiting tube 309 is fixedly connected to the outer wall of the sliding connector 3. The stabilizing cylinder 301 is sleeved on the outside of the limiting tube 309 away from the sliding connector 3. The end of the stabilizing cylinder 301 away from the limiting tube 309 is connected to the pressing plate 302. The outer wall of the pressing plate 302 is fixedly connected. Through the above-mentioned telescopic linkage design, it provides stable guidance during the movement of the pressing plate 302, limits radial displacement, and ensures that the thrust is transmitted axially. The pressing plate 302 is located inside the fixed tube 1 and is connected to the outer wall of the sliding connector 3 through the first spring 303. The first spring 303 is used to provide automatic reset force after the pressing plate 302 is released, thereby improving the continuity of operation. A support plate 304 is fixedly connected to the outer wall of the portion of the pressing plate 302 located outside the fixed tube 1. The support plate 304 contacts the outer wall of the fixed tube 1 and is used to provide support and guidance during the pressing process, to prevent the pressing plate 302 from swaying and to improve the stability of movement. In the example of this application, the infusion tube 9 is preferably made of a medical elastic material that can recover its original shape after multiple compression deformations, thereby ensuring the stability of liquid backflow and the reliability of repeated use. The portion of the pressing plate 302 located inside the fixed tube 1 is circular, and this circular structure is coaxially arranged with the sliding connector 3, the connector 6, and the tube holder 7. Through the above coaxial design, the pressing plate 302 can apply a uniform axial pushing and pulling force to the tube sheath 8 during movement, avoiding the tube sheath 8 from bending or the needle 10 from deviating from the predetermined puncture path due to eccentricity, thereby ensuring that the needle 10 advances and retreats smoothly and controllably. In use, the operator presses the pressure plate 302 with their thumb and holds the two second buckles 5 with their index and middle fingers to form a stable fulcrum. The thumb presses the pressure plate 302 forward, and the pressure plate 302, through its fixed connection with the infusion tube 9, directly transmits the pushing force to the infusion tube 9. At the same time, the second buckles 5 transmit the holding force to the sliding connector 3 through the slide cylinder 4, keeping the sliding connector 3 stable. The pressure plate 302 drives the infusion tube 9 to move forward, squeezing the first spring 303 to contract it, thereby allowing the needle 10 to extend from the distal end of the tube sheath 8. Under the elastic support of the tube holder 7, the tube sheath 8 always remains axially straight, effectively reducing the risk of bending. After the needle 10 is inserted into the patient's tissue, the operator injects saline into the infusion tube 9 through an external fluid supply device, causing the tissue to bulge and form a safety buffer layer. After the injection is completed, the operator releases the pressing plate 302. Under the restoring force of the first spring 303, the pressing plate 302 drives the infusion tube 9 to move backward quickly, so that the needle 10 is completely retracted into the tube sheath 8 in a very short time, forming an encapsulated retrieval path. With the above settings, the retraction speed of the needle 10 is much higher than the residence time of the liquid on the needle tip surface. The needle 10 is wrapped by the sheath 8 during the process of detaching from the tissue, thereby effectively preventing droplet adhesion and splashing. Structurally, it suppresses the source of splashing. Compared with the traditional injection device that requires manual needle removal, this solution achieves automatic and rapid retraction of the needle through spring reset, avoiding the problems of droplet retention and splashing caused by uneven speed and angle deviation during manual needle removal. It effectively reduces the probability of the tissue surface being lubricated by liquid, thereby improving the stability of subsequent snare operations.

[0020] Example 2: Please refer to Figure 1-5 Based on Embodiment 1, the present invention provides a technical solution: the blocking mechanism 13 further includes a stabilizing cylinder 301 and a limiting tube 309. One end of the limiting tube 309 is fixedly connected to the outer wall of the sliding connector 3. The stabilizing cylinder 301 is sleeved on the outside of the limiting tube 309 away from the sliding connector 3. The end of the stabilizing cylinder 301 away from the limiting tube 309 is fixedly connected to the outer wall of the pressing piece 302. One side of the pressing piece 302 extends to the outside of the fixed tube 1, and the pressing piece 302 is connected to the outer wall of the sliding connector 3 via a first spring 303 at the inner side of the fixed tube 1. The pressing piece 302 is fixedly connected to the outer wall of the infusion tube 9 at the middle of the inner side of the fixed tube 1. The outer part of the fixed tube 1 is used for the user to press and push, and the pressing plate 302 is fixedly connected to the support plate 304 on the outer wall of the outer part of the fixed tube 1, which is used to contact the outer wall of the fixed tube 1 to provide guidance support; the inner part of the pressing plate 302 is a circular structure, and the circular structure is coaxially arranged with the sliding connector 3, the connector 6, and the support tube 7, which is used to apply a pushing and pulling force to the tube sheath 8 during movement; the cutting wire 11 passes through the tube sheath 8 and extends to the distal end to form a sliding knot, and its other end is connected to the electrode 12 provided on the outer wall of the sliding cylinder 4. When the sliding cylinder 4 drives the sliding connector 3 to move axially, the cutting wire 11 moves relative to the tube sheath 8 to achieve the tightening of the sliding knot; This embodiment mainly realizes the stable snare and high-frequency electrosurgical excision of the lesion tissue after the snare is injected. The outer end of the sliding connector 3 is fixedly connected to the sliding cylinder 4. The sliding cylinder 4 is a cylindrical structure sleeved on the outer wall of the fixed tube 1. Its inner wall slides in contact with the outer wall of the fixed tube 1. The reason for adopting the cylindrical structure is that the cylindrical structure can limit the radial sway of the sliding connector 3 and ensure that it always maintains the coaxiality with the fixed tube 1 during axial movement, thereby accurately transmitting the operator's driving force to the cutting wire 11 at the far end. Two second buckles 5 are fixedly set on the outside of the sliding cylinder 4 as the driving input end of the snare tightening action. The cutting wire 11 in the operating assembly passes through the inside of the tube sheath 8 and extends to the distal end to form a retractable sliding knot structure. Its other end is led back along the inner wall of the tube sheath 8 to the position of the sliding cylinder 4 and connected to the electrode 12 fixed to the outer wall of the sliding cylinder 4. The electrode 12 is used to connect to an external high-frequency power supply to provide an energy path for electrocution. After the injection is completed, the lesion tissue is in a raised state, which creates good operating conditions for snare excision; the operator keeps the first buckle 2 stable and uses the index and middle fingers to pull the two second buckles 5 backward; this action drives the slide cylinder 4 to move backward along the axis of the fixed tube 1; since the slide cylinder 4 is fixedly connected to the sliding connector 3, the sliding connector 3 moves backward synchronously, thereby pulling the rear end of the cutting wire 11 to move backward relative to the tube sheath 8, so that the distal end of the slip knot gradually tightens. During this process, the tightening force of the sliding connector 3 forms a stable force transmission path along the cutting wire 11 inside the sheath 8; the sheath 8 binds the movement path of the cutting wire 11, so that the cutting wire 11 always maintains a coaxial relationship with the sheath 8 during the tightening process, avoiding the cutting wire 11 from shifting or slipping due to local bias; after the sliding connector tightens the lesion tissue, the operator connects the electrode 12 to the outside, and the high-frequency current forms a closed loop through the cutting wire 11 to realize high-frequency electroresection of the lesion tissue; This application uses the sheath 8 and the fixed tube 1 to restrain the movement path of the sliding connector 3 and the cutting wire 11, so that the snare tightening process is stable and controllable, the snare tightening is uniform and the force is reliable, avoiding cutting deviation or snare failure caused by loose structure, thereby improving the success rate of polyp snare removal and the accuracy of resection.

[0021] Example 3: Please refer to Figure 1-8Based on Embodiments 1 and 2, the present invention provides the following technical solution: A mounting port is provided on the side of the fixing tube 1 near the first buckle 2. Limiting frames 305 are provided on both the front and rear sides of the mounting port. An elliptical groove is provided on the limiting frame 305, and a rotating rod 306 is inserted into the elliptical groove. The middle part of the rotating rod 306 is fixedly connected to the outer wall of the pressure roller 307. A second spring 308 is provided between the lower side of the rotating rod 306 and the lower side of the inner wall of the elliptical groove. The second spring 308 provides support force to the rotating rod 306 to maintain pressure. The roller 307 is located on the upper side of the infusion tube 9; the pressure roller 307 is used to press the infusion tube 9 after the injection is completed and cooperate with the axial movement of the infusion tube 9 to achieve the backflow of liquid in the tube, so as to reduce the residual pressure in the needle 10; when the pressure roller 307 is pressed down, the pressure roller 307 overcomes the elastic force of the second spring 308 and presses the infusion tube 9 against the inner wall of the fixed tube 1, and then pushes the pressure roller 307 to roll in the direction of the first buckle 2, so that the liquid in the infusion tube 9 is pushed back towards the supply end, forming a negative pressure zone on one side of the needle 10 to achieve the backflow of residual drug solution; This embodiment mainly realizes the active release of residual pressure inside the infusion tube 9 and needle 10 after injection and before needle withdrawal, thereby completely eliminating the risk of liquid splashing at the moment of needle withdrawal. The blocking mechanism 13 is set on the side of the fixed tube 1 near the first buckle 2. Its core components include pressure roller 307, rotating rod 306, second spring 308 and limiting structure. Specifically, the infusion tube 9 is structurally located between the pressure roller 307 and the inner wall of the fixed tube 1, forming a flow channel that can be selectively compressed. During routine injection, the pressure roller 307 is in a high position, the infusion tube 9 remains unobstructed, and the drug solution can be infused normally. If the needle is withdrawn directly after the injection, residual positive pressure will remain inside the infusion tubing 9 and needle 10. Withdrawing the needle 10 at this time can easily cause liquid splashing, blurring the surgical field and making the tissue surface slippery. To address this problem, this embodiment provides the following solution: The operator first presses down on the pressure roller 307, causing the pressure roller 307 and the rotating rod 306 to move downward against the elastic force of the second spring 308, pressing the infusion tube 9 tightly against the lower part of the inner wall of the fixed tube 1, achieving partial closure of the infusion tube 9. At this time, the infusion tube 9 is flattened at this position, and the lumen is temporarily blocked. Subsequently, the operator maintains the pressing state and uses the same finger to push the pressure roller 307 towards the first buckle 2, causing the pressure roller 307 to roll along the surface of the infusion tube 9 towards the proximal end while in a compressed state. During this process, the infusion tube 9 undergoes local compression deformation when passing under the pressure roller 307, and the liquid inside the tube is pushed towards the infusion end. After the pressure roller 307 rolls over, the infusion tube 9 recovers its original shape in the compressed area by its own elasticity, thereby forming an instantaneous negative pressure zone behind this area, i.e., on the side of the needle 10. This negative pressure actively draws the residual liquid inside the needle 10 back into the infusion tube 9, achieving mechanical backflow. After the above-mentioned aspiration operation is completed, the residual pressure inside the infusion tube 9 and the needle 10 has been significantly reduced or even eliminated. At this time, the operator can safely pull out the needle 10 without splashing the medicine. After the operation is completed, the rotating rod 306 is released, and the pressure roller 307 automatically returns to the high position under the elastic force of the second spring 308, releasing the clamp on the infusion tube 9 and restoring the unobstructed state of the pipeline. During the rolling of the pressure roller, the infusion tube 9 forms a partially closed section between the pressure roller 307 and the inner wall of the fixed tube 1. This closed section moves along the axial direction of the infusion tube 9 as the pressure roller 307 moves, squeezing the liquid in the tube towards the supply end during the movement. After the pressure roller 307 rolls past, the originally compressed area quickly returns to its original state, thus forming an instantaneous volume expansion area on the side near the needle 10. Since this area is in a relatively closed state for a short time, a negative pressure is formed at the needle tip, thereby achieving active backflow of residual liquid.

[0022] With the above setup, without adding a complex valve body structure, the partial closure of the infusion tube and the directional back push of the liquid inside the tube are achieved by using only a single rollable pressure roller 307. The structure is simple and the operation is intuitive. It significantly reduces the risk of liquid splashing during the needle withdrawal process, improves the clarity of the surgical field, and avoids the tissue surface from becoming too slippery due to drug residue, thus creating good operating conditions for subsequent snare removal.

[0023] Example 4: Please refer to Figure 1-8 Based on Embodiments 1, 2, and 3, the present invention provides the following technical solution: one end of the rotating rod 306 extends to the outside of the fixed tube 1, and a hexagonal slot is provided at the end of the rotating rod 306 located on the outside of the fixed tube 1 for rigid connection with an external angle encoder. The outer wall of the pressure roller 307 is provided with grooves in a ring shape to increase the friction with the outer wall of the infusion tube 9. When the pressing plate 302 drives the infusion tube 9 to move axially, the infusion tube 9 drives the pressure roller 307 to rotate through friction. The pressure roller 307 drives the rotating rod 306 to generate a corresponding angular displacement. This angular displacement is transmitted to the external angle encoder through the hexagonal slot and converted into a real-time monitoring signal of the needle tip 10 extension length, thereby realizing precise control of the injection depth. This embodiment mainly realizes real-time monitoring and precise control of injection depth to avoid tissue damage or poor injection effect caused by improper puncture depth. The hexagonal slot at the outer end of the rotating rod 306 is used to rigidly connect with an external angle encoder, thereby converting the small rotation of the rotating rod 306 into an electrical signal that can be recognized by the electronic system. In the example of this application, since the rotating rod 306 is fixedly connected to the pressure roller 307, and the pressure roller 307 is in contact with the outer wall of the infusion tube 9, under normal conditions there is slight contact and no compression is generated. Therefore, the axial displacement of the infusion tube 9 will cause the pressure roller 307 to rotate passively. Specifically, when the operator pushes the pressing plate 302 to move the infusion tube 9 forward, the friction between the infusion tube 9 and the pressure roller 307 drives the pressure roller 307 to rotate, and the pressure roller 307 drives the rotating rod 306 to rotate accordingly. Conversely, when the pressing plate 302 is reset under the action of the first spring 303 and the infusion tube 9 moves backward, the pressure roller 307 rotates in the opposite direction. Meanwhile, the pressing plate 302 has a coaxial circular structure and is arranged coaxially with the sliding connector 3, connector 6, and support tube 7. Its axial displacement is linearly related to the extension length of the needle 10. The distance the pressing plate 302 moves forward is the same as the distance the needle 10 extends forward. Therefore, during the process of pressing the pressing plate 302 to advance the needle 10, the displacement of the infusion tube 9 is directly mapped to the extension length of the needle 10. The displacement of the infusion tube 9 is then converted into the rotation angle of the pressure roller 307 through friction drive, and then transmitted to the external angle encoder through the rotating rod 306 to form a complete measurement link. In the example of this application, the outer surface of the pressure roller 307 is provided with anti-slip texture, and the pressure roller 307 and the infusion tube 9 maintain a preset contact pressure, so that the infusion tube 9 can stably drive the pressure roller 307 to rotate synchronously during axial movement, thereby ensuring the correspondence between angular displacement and infusion tube displacement.

[0024] Before use, the operator calibrates the angle encoder to zero, setting the state where the needle 10 is fully retracted into the sheath 8 as the zero point. During operation, the control module reads the angle signal output by the angle encoder in real time. In this embodiment, the axial displacement of the infusion tube 9 is proportionally related to the rotation angle of the pressure roller 307, which is determined by the effective rolling radius of the pressure roller 307. At the same time, since the infusion tube 9 is fixedly connected to the needle 10, the displacement of the infusion tube 9 is one-to-one with the extension length of the needle 10. Thus, the extension length of the needle 10 can be calculated by detecting the angle change of the pressure roller. The operator can accurately control the pressure of the thumb based on this real-time feedback data to avoid inserting too deeply and causing tissue perforation or inserting too shallowly and causing inaccurate drug injection position. In addition, the operator can also adjust the injection volume based on the depth information to ensure that the drug is accurately injected into the submucosa rather than the deeper muscle layer, thereby improving the injection effect and reducing the risk of complications. After the injection is completed, the needle is retrieved. The system can record the maximum displacement value during this operation as an operation parameter to achieve data management and facilitate postoperative review or reference and comparison of subsequent cases. With the above settings, without changing the main mechanical structure, the mechanical displacement is converted into a measurable angle signal through the frictional transmission relationship between the pressure roller 307 and the infusion tube 9, realizing real-time monitoring and precise control of the injection depth. This design allows the operator to intuitively understand the position of the needle in the tissue, greatly reducing the high dependence of the operation on the operator's experience and feel, and improving the safety and consistency of the operation.

[0025] This solution provides an integrated medical device that combines injection and snare removal functions, allowing the operator to complete tissue injection and subsequent snare removal in a single procedure. This avoids the time-consuming, positioning errors, and discontinuous operation problems associated with repeated changes of traditional instruments. Furthermore, by incorporating an axially driven infusion tube 9 and an elastic reset structure, the needle 10 can quickly retract into the sheath 8 after injection. This structural encapsulation reduces needle exposure time, minimizing the risk of fluid adhesion and ejection. Further, a pressure roller 307 rolling-type blocking mechanism is introduced, which locally compresses the infusion tube 9 and rolls it axially to prevent the fluid inside the tube from being ejected. The needle is pushed back to the supply end and a negative pressure area is formed on the needle side, which effectively eliminates residual pressure and suppresses liquid splashing at the moment of needle withdrawal, improving the clarity of the surgical field and the dryness of the tissue surface. At the same time, the coaxial transmission structure of the sliding connector 3 and the cutting wire 11 makes the snare tightening process stable and reliable, with uniform force and less tendency to deviate, improving the success rate of polyp retrieval and the accuracy of excision. In addition, through the frictional transmission relationship between the pressure roller 307 and the infusion tube 9, the mechanical displacement is converted into an angular displacement signal and can be connected to an external detection device to realize real-time monitoring and quantitative control of the needle extension length, thereby reducing the dependence on the operator's experience and improving the accuracy of injection depth control and surgical safety.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A snare with an injection needle, comprising a fixing tube (1), an operating handle disposed at one end of the fixing tube (1), and a connector (6) disposed at the other end of the fixing tube (1), wherein the fixing tube (1) is provided with an axially movable sliding connector (3), characterized in that, Also includes: The blocking mechanism (13) is disposed on the outer wall of the fixed tube (1) and close to the operating handle; The operating assembly includes a sheath (8), an infusion tube (9) inserted within the sheath (8), a needle (10) located at the distal end of the infusion tube (9), and a cutting wire (11) for snare excision; the proximal end of the sheath (8) is connected to the fixed tube (1) via the connector (6); the proximal end of the infusion tube (9) passes through the blocking mechanism (13) and is connected to the sliding connector (3). The blocking mechanism (13) includes a pressing plate (302) and a pressure roller (307). The pressing pad (302) is axially movable relative to the fixed tube (1) and is used to drive the infusion tube (9) to move axially, so as to drive the needle (10) to extend or retract relative to the tube sheath (8). The pressure roller (307) is rotatably mounted on the fixed tube (1) and presses against the outer wall of the infusion tube (9). When the pressing plate (302) drives the infusion tube (9) to retract towards the proximal end, the pressure roller (307) maintains a pressing state on the infusion tube (9) to form a negative pressure on the proximal side of the infusion tube (9), thereby drawing back the residual liquid in the needle (10).

2. The snare with an injection needle according to claim 1, characterized in that: The operating handle includes a first buckle (2) fixed to the far end of the fixed tube (1) and two second buckles (5) connected to the sliding connector (3) via a slide cylinder (4). The first buckle (2) and the two second buckles (5) form a three-finger grip structure. The slide cylinder (4) is sleeved on the outer wall of the fixed tube (1) and is used to drive the sliding connector (3) to move axially.

3. The snare with an injection needle according to claim 2, characterized in that: The inner wall of one side of the connector (6) is fixedly connected to the outer wall of the fixed tube (1), and an elastic support (7) is provided between the inner wall of the connector (6) away from the fixed tube (1) and the tube sheath (8).

4. A snare with an injection needle according to claim 3, characterized in that: The cutting wire (11) is inserted into the tube sheath (8) and extends to the distal end to form a sliding knot. The proximal end of the cutting wire (11) is connected to the electrode (12) disposed on the outer wall of the sliding cylinder (4).

5. A snare with an injection needle according to claim 4, characterized in that: The proximal end of the infusion tube (9) is fixedly connected to the pressure plate (302) and moves axially synchronously with the pressure plate (302); the part of the pressure plate (302) located inside the fixed tube (1) is connected to the sliding connector (3) through the first spring (303).

6. A snare with an injection needle according to claim 5, characterized in that: The blocking mechanism (13) also includes a stabilizing cylinder (301) and a limiting tube (309). One end of the limiting tube (309) is fixedly connected to the sliding connector (3). The stabilizing cylinder (301) is sleeved on the outside of the limiting tube (309) away from the sliding connector (3). The end of the stabilizing cylinder (301) away from the limiting tube (309) is fixedly connected to the pressing piece (302).

7. A snare with an injection needle according to claim 6, characterized in that: The inner wall of the pressing pad (302) inside the fixed tube (1) is fixedly connected to the outer wall of the infusion tube (9). The part of the pressing pad (302) outside the fixed tube (1) is provided with a support plate (304). The support plate (304) slides in contact with the outer wall of the fixed tube (1) to provide guiding support.

8. A snare with an injection needle according to claim 7, characterized in that: The pressing plate (302) is located inside the fixed tube (1) and has a circular inner wall structure. The circular structure is coaxial with the sliding connector (3), the connector (6), and the support tube (7) and is used to apply a pushing and pulling force to the tube sheath (8) during movement.

9. A snare with an injection needle according to claim 8, characterized in that: The fixed tube (1) has an installation port on the side near the first buckle (2). The installation port is provided with a limit frame (305) on both the front and rear sides. The limit frame (305) has an elliptical groove. A rotating rod (306) is inserted into the elliptical groove. The middle part of the rotating rod (306) is fixedly connected to the outer wall of the pressure roller (307). A second spring (308) is provided between the lower side of the rotating rod (306) and the lower side of the inner wall of the elliptical groove. The second spring (308) is used to provide support force to the rotating rod (306) and to elastically press the pressure roller (307) against the upper side of the infusion tube (9).

10. A snare with an injection needle according to claim 9, characterized in that: One end of the rotating rod (306) extends to the outside of the fixed tube (1). The rotating rod (306) has a hexagonal groove at one end on the outside of the fixed tube (1). The outer wall of the pressure roller (307) has a uniformly circumferential groove to increase the friction with the outer wall of the infusion tube (9).

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