Snare with controllable opening diameter

Abstract

This utility model discloses a snare with a controllable opening diameter; relating to the field of medical device technology, it includes a connecting rod, one end of which is equipped with a variable snare assembly. The connecting rod contains a hydraulic mechanism for controlling the opening diameter of the variable snare assembly. By sliding the hydraulic rod in the hydraulic mechanism, contrast fluid filled in the hydraulic chamber of the connecting rod is pushed into the tube of the variable snare assembly, causing the tube to expand. A shape memory alloy wire then causes the tube to contract, snareing and fixing the object to be retrieved inside the patient's body. The position of the snare is observed in conjunction with the contrast points within the tube and the contrast fluid to determine the relative position between the snare and the object to be retrieved. This utility model has the advantages of being easy to use, convenient for observation, and simple in structure.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a snare device with a controllable opening diameter. Background Technology

[0002] In clinical surgery, situations often arise where it is necessary to remove objects, including foreign bodies in blood vessels or improper placement of stents. To address this, snares have been specially designed to capture objects. These snares have a special hook, i.e., hook-shaped snares, to hook the object and then fix it in place with a locking wire. There is also a type of snare that is ring-shaped, made of shape memory material, called a single-ring snare.

[0003] Commercially available snares are prone to detachment during actual use, easily separating the captured object from the snare and requiring repeated attempts. If a snare is the wrong size, the instrument must be replaced, significantly increasing surgical time. Furthermore, existing snares require pulling the entire device backward while holding it to shrink the snare tip and encircle the object, which is inconvenient in practice and increases the risk of contact with surrounding tissues, potentially causing damage. Additionally, existing snares make it difficult to observe their position within the body, which may affect the normal progress of the surgery and could even lead to injury to the patient. Utility Model Content

[0004] To address the aforementioned problems, this utility model aims to provide a snare with a controllable opening diameter. By designing a polymer material tube that can deform in conjunction with a shape memory alloy wire, and combining this with the hydraulic action within the connecting rod, the tube can be opened or closed to the desired diameter to snare the object. This snare has the advantages of being easy to use, easy to observe, and having a simple structure.

[0005] The main idea of ​​the technical solution adopted in this utility model is as follows: a variable snare assembly is designed. A shape memory alloy wire is set in a hollow annular tube made of polymer material to shrink the tube into a three-layer small-diameter annular structure so that the snare can be inserted into the patient's body to retrieve the object. A piston rod is set in the connecting rod to push liquid into the tube so that the shrunken tube can be expanded. Then, through the reset characteristics of the shape memory alloy wire, the tube is shrunken again to snare and retrieve the object.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A snare with controllable opening diameter includes a connecting rod, one end of which is provided with a variable snare assembly, and the connecting rod is provided with a hydraulic mechanism for controlling the opening diameter of the variable snare assembly.

[0008] The variable snare assembly includes a tube body connected to a connecting rod, and a shape memory alloy wire is provided inside the tube body. The shape memory alloy wire can restore the tube body to a contracted state, and multiple developing points are also fixed inside the tube body.

[0009] Based on the above technical solution, the tube body is further made of polymer material.

[0010] Based on the above technical solution, the shape memory alloy wire is further described as a nickel-titanium alloy material.

[0011] Based on the above technical solution, the developing point is further made of a platinum-iridium alloy or other metallic material.

[0012] The hydraulic mechanism includes a hydraulic cavity located at one end of the connecting rod that is connected to the pipe body, and a hydraulic rod is slidably disposed in the hydraulic cavity.

[0013] Based on the above technical solution, further, a push block is provided at the end of the hydraulic rod away from the hydraulic chamber, and a sliding groove that cooperates with the push block is provided on one side of the connecting rod.

[0014] Based on the above technical solution, further, in the variable loop assembly and hydraulic mechanism, the tube body and hydraulic cavity are filled with contrast agent.

[0015] The beneficial effects of this utility model are:

[0016] 1. By designing a variable snare assembly and a hydraulic mechanism, the tube body is contracted via a shape memory alloy wire to insert the snare into the patient's body. A hydraulic rod pushes liquid from the hydraulic chamber into the tube body, opening it. When the liquid injection stops, the shape memory alloy wire causes the tube body to contract again, pushing the liquid back into the hydraulic chamber, thus snareing and removing objects from the patient's body. Compared to existing products, this invention allows for control of the innermost diameter of the tube body according to the size of different objects, offering advantages in ease of use and indirectly improving surgical efficiency.

[0017] 2. By setting contrast points inside the tube and combining the contrast agent filled in the tube and hydraulic cavity, the snare can be observed as a whole under X-ray irradiation after it is inserted into the patient's body, so as to determine whether the snare has reached the position to be removed. This makes the present invention easy to observe, thereby improving the accuracy of snare removal.

[0018] 3. The overall structure of this utility model is relatively simple, and the cost of each component is low, making it easy to mass-produce. The device has good overall sealing performance, and the surface of the snare can be easily cleaned after use for reuse. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the present invention in its contracted state;

[0020] Figure 2 This is a three-dimensional structural diagram of the present invention in a semi-open state;

[0021] Figure 3 This is a three-dimensional structural diagram of the present invention in its fully opened state.

[0022] Figure 4 This is a cross-sectional view of the variable snare assembly in its contracted state.

[0023] Figure 5 A cross-sectional view of the variable snare component in a semi-open state;

[0024] Figure 6 A cross-sectional view of the variable snare component in its fully open state;

[0025] Figure 7 for Figure 4 A detailed view of point A;

[0026] Figure 8 This is a three-dimensional structural diagram of the hydraulic mechanism.

[0027] The components are: 1. Connecting rod; 2. Variable loop assembly; 201. Tube body; 202. Shape memory alloy wire; 203. Development point; 3. Hydraulic mechanism; 301. Hydraulic chamber; 302. Hydraulic rod; 303. Push block; 304. Slide groove. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] The inventors discovered that commercially available snares are prone to detachment during actual use, easily separating the captured object from the snare and requiring repeated attempts. If a snare is the wrong size, the instrument must be replaced, significantly increasing surgical time. Furthermore, existing snares require pulling the entire device backward to shrink the snare tip and encircle the object when inserted into blood vessels or other areas, which is inconvenient in practice and increases the risk of contact with surrounding tissues, potentially causing damage. Additionally, existing snares make it difficult to observe their position within the body when inserted, which may affect the normal progress of the surgery and could even lead to injury to the patient.

[0030] Based on the above findings, this application proposes a snare with a controllable opening diameter. A shape memory alloy wire is installed inside a hollow annular tube made of polymer material to shrink the tube into a three-layered, small-diameter annular structure, allowing the snare to be inserted into the patient's body for retrieval. A piston rod is installed in the connecting rod to push liquid into the tube, ensuring the shrinking tube continuously opens to a controllable diameter. The shape memory alloy wire's restoring properties cause the tube to shrink again, snareing and retrieving the object. This device is convenient to use, easy to observe, and has a simple structure.

[0031] See Figures 1-3 This application discloses a snare with controllable opening diameter, including a connecting rod 1, which is a slender hollow rod made of lightweight metal or plastic with high strength. A variable snare assembly 2 is connected to one end of the connecting rod 1.

[0032] See Figures 4-7 The variable loop assembly 2 includes a tube 201, which is made of a highly elastic polymer material. The tube 201 is a closed, circular, hollow tube. A shape memory alloy wire 202 is disposed inside the tube. The shape memory alloy wire 202 is made of nickel-titanium alloy and its initial shape is as follows: Figure 4 In the multi-layered bending state shown, the shape memory alloy wire 202 can keep the tube 201 in the same bending and shrinking state as it, or make the tube 201 in the unfolded state shrink back to the bending state.

[0033] In some embodiments, a threaded hole is provided on the wall of the pipe body 201, and an installation head that mates with the threaded hole is provided at one end of the connecting rod 1. During installation, the connecting rod 1 and the pipe body 201 can be fixed by screwing the installation head into the threaded hole through threaded engagement. In some embodiments, multiple threaded holes at different positions can be provided on the pipe body 201. This invention can install the connecting rod 1 and the pipe body 201 in different connection states according to the actual usage requirements. That is, the connecting rod 1 and the pipe body 201 can be connected in a state where they are perpendicular to each other or parallel to each other. During installation, a sealing plug can be used to block and seal the other threaded holes on the pipe body 201.

[0034] The connecting rod 1 is equipped with a hydraulic mechanism 3 for adjusting the degree of expansion of the tube 201, see reference. Figure 8 The hydraulic mechanism 3 includes a hydraulic chamber 301 formed in the connecting rod 1. One end of the hydraulic chamber 301 is connected to the mounting head of the connecting rod 1, that is, the liquid in the hydraulic chamber 301 can be transported to the pipe body 201 through the mounting head.

[0035] A hydraulic rod 302 is slidably disposed in the hydraulic chamber 301. The hydraulic rod 302 is in close contact with the hydraulic chamber 301. When the hydraulic rod 302 slides, it can push the liquid filled in the hydraulic chamber 301 into the tube 201, thereby unfolding the tube 201 which is in a bent and contracted state, so as to snare objects in the patient's body through its central region. By adjusting the hydraulic rod 302 along the axial direction of the connecting rod 1, the amount of liquid filled into the tube 201 can be adjusted, thereby adjusting the degree of unfolding of the tube 201.

[0036] In some embodiments, a push block 303 is provided at the end of the hydraulic rod 302 away from the hydraulic chamber 301. A groove 304 is provided on one side of the connecting rod 1 along its axial direction. The push block 303 passes through the groove 304. When using this utility model, the hydraulic rod 302 can be adjusted along the axial direction of the connecting rod 1 by pushing the push block 303 along the groove 304, thereby controlling the liquid filled into the tube 201.

[0037] When the connecting rod 1 is inserted into the patient's body, the hydraulic rod 302 is pushed to open the tube 201. When the area of ​​the middle region of the tube 201 is larger than the cross-sectional area of ​​the object to be retrieved, it indicates that the tube 201 can trap the object inside the patient's body. At this point, the hydraulic rod 302 is stopped from being pushed closer to the tube 201. The tube 201 then gradually returns to its original position under the action of the shape memory alloy wire 202, pushing the liquid in the tube 201 back into the hydraulic chamber 301. At the same time, the hydraulic rod 302 is pushed to slide back along the connecting rod 1, thereby restoring the tube 201 to its original position. Returning to its initial bent state, the circular area formed in the middle of the tube 201 gradually contracts until it encircles and fixes the object to be retrieved. Then, the object can be removed from the patient's body by pulling out the connecting rod 1, using the encircling action of the tube 201. In addition, when it is confirmed that the tube 201 can encircle the object to be retrieved, the push block 303 can be manually slid in the opposite direction to reset the hydraulic rod 302, thereby drawing the liquid filled in the tube 201 back into the hydraulic chamber 301 in the connecting rod 1, thereby increasing the contraction speed of the tube 201 and improving the retrieval efficiency.

[0038] In some embodiments, the liquid filled in the hydraulic chamber 301 is a contrast agent. At the same time, multiple imaging points 203 are fixed inside the tube 201 by means of bonding or other methods. The imaging points 203 are hollow cylindrical structures with the same curvature as the inner wall of the tube 201. The imaging points 203 are made of metal materials with good imaging effects, such as platinum-iridium alloy. When the contrast agent and imaging points 203 are observed by X-ray irradiation equipment, they can show good imaging effects. Therefore, when this utility model is used, it can be used with an external X-ray observation device to observe the position of the device in the patient's body and to observe the position between the snare as a whole and the object to be removed, thereby improving the accuracy of snare.

[0039] Specific application examples

[0040] During surgery, external X-ray equipment is used for observation. If a foreign object is found in the patient's body, this snare device can be used to remove the foreign object.

[0041] The doctor holds the connecting rod 1 and inserts the tube 201, which is in a retracted state, into the patient's body. During this time, the doctor uses an X-ray device to observe the imaging point 203 in the tube 201 and the contrast fluid in the connecting rod 1 to determine the relative position between the snare and the object to be removed.

[0042] Once it is confirmed that the tube body 201 is in a position that can snare the object, the push block 303 is manually slid along the groove 304 on the connecting rod 1 to fill the tube body 201 with contrast fluid. The contrast fluid fills the tube body 201, causing the internal shape memory alloy wire 202 to be initially stressed and open with the tube body 201 until the area of ​​the hollow region formed in the middle is larger than the cross-sectional area of ​​the object to be retrieved. By controlling the dosage of the injected contrast fluid, the opening range of the device can be controlled to make it closer to the object to be retrieved.

[0043] The tube 201 is fitted onto the object to be removed, and the push block 303 is released or slid in the opposite direction to allow the tube 201 to contract under the action of the shape memory alloy wire 202, thereby reducing the dose of contrast agent in the tube 201. The area of ​​the hollow region formed in the middle of the tube 201 is gradually reduced until the tube 201 can snare and fix the object to be removed. Then the connecting rod 1 and the entire tube 201 are pulled out of the patient's body to remove the foreign object.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A snare with controllable opening diameter, comprising a connecting rod (1), characterized in that, One end of the connecting rod (1) is provided with a variable loop assembly (2), and the connecting rod (1) is provided with a hydraulic mechanism (3) for controlling the opening diameter of the variable loop assembly (2). The variable snare assembly (2) includes a tube (201), a shape memory alloy wire (202) is provided inside the tube (201), and a plurality of developing points (203) are also provided inside the tube (201). The hydraulic mechanism (3) includes a hydraulic chamber (301) opened in the connecting rod (1), and a hydraulic rod (302) is slidably arranged in the hydraulic chamber (301).

2. The snare with controllable opening diameter according to claim 1, characterized in that, The tube body (201) is made of polymer material.

3. The snare with controllable opening diameter according to claim 1, characterized in that, The shape memory alloy wire (202) is a nickel-titanium alloy.

4. A snare with a controllable opening diameter according to claim 1, characterized in that, The developing point (203) is a platinum-iridium alloy.

5. A snare with a controllable opening diameter according to claim 1, characterized in that, The hydraulic rod (302) has a push block (303) at one end away from the hydraulic chamber (301), and a groove (304) that cooperates with the push block (303) is provided on one side of the connecting rod (1).

6. A snare with a controllable opening diameter according to claim 1, characterized in that, In the variable loop assembly (2) and the hydraulic mechanism (3), the tube body (201) and the hydraulic chamber (301) are filled with contrast agent.

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