Foreign matter removing device for slender pipe and manufacturing method of foreign matter removing device

Abstract

The invention discloses a slender tube foreign body taking-out device and a manufacturing method thereof, and relates to the technical field of foreign body grabbing in blood vessels, the slender tube foreign body taking-out device comprises a capturing rod, one end of the capturing rod is provided with a handle detachably connected with the capturing rod, and the other end is provided with a capturing unit used for capturing foreign bodies; the capturing unit is a single spring mechanism which is spirally arranged in the length direction of the capturing rod; the spring mechanism comprises an inner core wire and a spring wire wound around the outer ring of the inner core wire, the inner core wire is spirally arranged along the end, away from the handle, of the capturing rod, and the inner core wire and the spring wire are both made of nickel-titanium memory alloy materials. According to the device, through the special design of the materials and the structures of the inner core wire and the spring wire, it is ensured that the spring mechanism can be stably retracted and pushed out of the sheathing canal every time, faults are avoided, and the working efficiency is improved; and in addition, foreign matters with different specifications and characteristics are considered in the shape design of the spring mechanism, so that smaller foreign matters or foreign matters with irregular surfaces or soft texture can be effectively bound, and the applicability of the spring mechanism is greatly expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of intravascular foreign body grabbing, and in particular to a slender tube foreign body removal device and a manufacturing method thereof. Background Art

[0002] During vascular interventional treatment, human tissue, catheters or guide wires sometimes become twisted, broken and fall off. These foreign objects remaining in the patient's blood vessels may cause a series of complications, so it is necessary to remove them.

[0003] Traditionally, a three-ring foreign body snare or a gooseneck catcher with a snare structure is used to remove foreign bodies. During the operation, the snare is first placed on the surface of the foreign body, and then the snare is pulled out of the body by external force to remove the foreign body. However, since the snare lacks self-binding properties, the foreign body can easily separate from it, making it difficult to remove the foreign body. Repeated application and pulling actions will increase the risk of surgery.

[0004] In contrast, a medical disposable three-dimensional spatial mesh capture device (application number: CN201721907969.2) that later appeared provided an improved solution. This capture device consists of a capture rod and handles at both ends of the device and a capture net. The capture net is composed of three capture wires that are twisted together into a spiral shape to form a three-dimensional mesh structure. The capture rod includes a sleeve and an inner core wire. The free end of the capture net is cross-wound and fixed by a stainless steel sleeve, and the other end is fixedly connected to the inner core wire. When in use, the capture net is first retracted into the sleeve, and after reaching the target position, the handle is pushed to unfold the capture net, forming a three-dimensional spatial mesh structure with self-binding force. Finally, the capture net is pulled out of the body by external force to complete the capture task.

[0005] Although the design gives the capture device a certain self-binding ability, due to its structural characteristics, when the capture net is pushed out from the inside of the casing, the three capture wires cannot be correctly unfolded every time, and sometimes they will be entangled with each other, which will affect its normal working state and increase the failure rate; in addition, the design can only effectively capture foreign objects within a specific size range - that is, those that can fit into the gap between two adjacent capture wires. For foreign objects that are too large, the entire capture net can only move in the same direction after unfolding until it is pushed out of the body, while foreign objects that are too small may escape from the gap, resulting in capture failure. Summary of the invention

[0006] In order to solve the problems that the three capturing wires of the above-mentioned capture device cannot be correctly unfolded every time, and sometimes become entangled with each other, affecting the normal working state and increasing the failure rate, and that the capture device can only effectively capture foreign objects within a specific size range and has limitations, the present invention provides a slender tube foreign object removal device and a manufacturing method thereof.

[0007] The technical solution of the present invention is as follows:

[0008] A slender tube foreign body removal device comprises a capture rod, one end of the capture rod is provided with a handle detachably connected thereto, and the other end of the capture rod is provided with a capture unit for capturing foreign bodies.

[0009] Specifically, the capture unit is a single spring mechanism spirally arranged along the length direction of the capture rod. The spring mechanism includes an inner core wire and a spring wire wound around its outer ring. The inner core wire is spirally arranged along the end of the capture rod away from the handle, and both the inner core wire and the spring wire are made of nickel-titanium memory alloy. The nickel-titanium memory alloy has a shape memory effect and super elasticity. These properties enable the inner core wire and the spring wire to withstand large deformations without plastic deformation, and can quickly return to their original shape and maintain a certain tension after being subjected to external force.

[0010] When the removal device is used to remove foreign bodies in a blood vessel, the operator first selects a suitable sheath according to the size of the blood vessel, then removes the handle of the removal device, inserts the capture rod into the sheath, and installs the handle after the capture rod extends from the sheath. Next, the capture rod is pulled to retract the spring mechanism into the sheath. When the sheath reaches the capture position, the handle is pushed to release the spring mechanism. Finally, the spring mechanism is pulled out of the blood vessel, and the self-binding property of the spring mechanism is relied upon to bind the foreign body in the blood vessel and take it out of the blood vessel.

[0011] Since the inner core wire and spring wire of the spring mechanism are made of nickel-titanium memory alloy with shape memory effect and superelasticity, the spring mechanism can quickly return to its original shape and maintain a certain tension after being subjected to external force. Therefore, the operator can quickly restrain the foreign object and it is not easy to loosen during the outward pulling process.

[0012] In addition, when the spring mechanism is retracted into or pushed out of the sheath, the part located inside the sheath will become straight, while the part located outside the sheath remains in a working state. This design enables the spring mechanism to be smoothly retracted into and pushed out of the sheath every time, avoiding malfunctions and thus improving work efficiency.

[0013] Of course, the specifications of the above-mentioned spring mechanism can also be set according to other situations. Smaller outer diameters and inner diameters are suitable for thin or narrow blood vessels, while larger outer diameters and inner diameters are more suitable for thicker blood vessels or situations that require greater gripping force. Through this flexible design, trauma to the patient can be reduced, making the removal process safer and more efficient.

[0014] As an implementation manner, the inner core wire is a spiral columnar structure with a constant diameter.

[0015] Furthermore, the end of the inner core wire away from the capture rod is provided with a spiral cone structure with a gradually decreasing diameter, and the size of the end opening can also be set according to the minimum size of the foreign matter, so that even smaller foreign matters can be successfully captured, thereby improving the adaptability of the retrieval device.

[0016] As another implementation method, the inner core wire is a spiral cone structure with a diameter gradually decreasing along the end away from the capture rod, which is convenient for processing, and the size of the end opening can also be set according to the minimum size of foreign matter, and has a wide range of applications.

[0017] To accommodate different clinical anatomical structures, the outer diameter of the spring mechanism is set to 1 mm-5 mm, and the wall thickness is set to 1 mm-1.25 mm.

[0018] Preferably, the cross-sectional shape of the spring wire is circular / triangular / a shape with more than three sides. The removal device provides spring wires with a variety of different cross-sectional shapes to facilitate operators to select according to specific usage requirements and foreign body characteristics.

[0019] Specifically, spring wire with a circular cross-section is easier to process and generates less friction when contacting foreign objects, making it suitable for capturing large objects or situations where friction requirements are not high. However, a triangle or a shape with more than three sides is suitable for situations where friction requirements are high. It can provide greater friction when contacting foreign objects and is particularly suitable for capturing foreign objects with irregular surfaces or soft textures, because the increased friction helps to grasp the foreign objects more firmly, thereby improving the capture efficiency.

[0020] For example, when handling delicate foreign objects or those requiring delicate manipulation, a circular cross-section may be preferred to reduce damage, whereas when handling foreign objects that require high stability and gripping force, a triangular or other polygonal cross-section may be selected.

[0021] In order to improve the structural strength, the inner core wire and the catch rod are integrally manufactured, and the diameter of the catch rod is larger than the diameter of the inner core wire, and there is a smooth transition between the two to reduce structural stress and improve structural strength.

[0022] The present invention also provides a method for manufacturing the above-mentioned slender tube foreign body removal device, comprising the following steps:

[0023] S1. Preparation of spring mechanism:

[0024] First, the spring wire is wound into a straight spring tube, wherein the inner diameter of the spring tube matches the outer diameter of the inner core wire. Finally, the inner core wire and the spring tube are assembled into one body and installed on a heat setting tool for heat setting treatment.

[0025] It should be noted that the above-mentioned heat setting tool is designed according to the shape of the spring mechanism to be obtained.

[0026] For example, the heat setting tooling is set as follows: the heat setting tooling includes a mold block that is compatible with the internal specifications of the spring mechanism, the inner core wire and the spring tube of the spring mechanism are wound around the outer ring of the mold block, and then enter a space with a certain temperature for heat setting treatment together with the mold block, and finally a completed spring mechanism is obtained, and then the spring mechanism is removed from the mold block, wherein the mold block is made of heat-resistant alloy steel, high-speed steel or cemented carbide and other materials, which can meet the requirements of heat resistance, wear resistance and strength during the heat setting process.

[0027] S2. Assembly:

[0028] The spring mechanism prepared in step S1 is used as a capture unit, and is assembled and connected with other components to obtain a slender tube foreign body removal device.

[0029] The beneficial effects of the slender tube foreign body removal device of the present invention are:

[0030] 1. Through the special design of the material and structure of the inner core wire and spring wire, it is ensured that the spring mechanism can be smoothly retracted and pushed out of the sheath every time, avoiding malfunctions and improving work efficiency;

[0031] 2. The design of the shape of the spring mechanism takes into account foreign objects of different specifications and characteristics. It can also effectively restrain small foreign objects with irregular surfaces or soft textures, which greatly expands its applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the attached picture:

[0033] Figure 1 This is a schematic structural diagram of a slender tube foreign body removal device of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the present embodiment 1;

[0035] Figure 3 This is a schematic diagram of the structure of Embodiment 2;

[0036] Figure 4 This is a schematic diagram of the structure of Embodiment 3;

[0037] Figure 5 Schematic diagram of the assembly structure of the spring tube and the inner core wire in Example 1 (the cross-sectional shape of the spring wire is a triangle);

[0038] Figure 6 for Figure 5 A is an enlarged structural diagram (the cross-section of the spring wire is a rectangle);

[0039] Figure 7 It is a schematic diagram of the structure of the spring mechanism of the present invention being retracted into the sheath tube;

[0040] Figure 8 for Figure 7 BB-direction cross-sectional diagram;

[0041] Fig. 9 for Figure 8 A schematic diagram of the enlarged structure at C;

[0042] Fig.10 This is a schematic diagram of the structure of the spring mechanism of the present invention pushing out the sheath tube;

[0043] Fig.11 This is a schematic diagram of the use state of the spring mechanism in this embodiment 1;

[0044] Fig.12 This is a schematic diagram of another use state of the spring mechanism in Embodiment 1;

[0045] The components represented by the reference numerals in the figure are:

[0046] 1. Catch rod; 2. Handle; 3. Spring mechanism; 31. Inner core wire; 32. Spring wire; 4. Spring tube; 5. Sheath tube; 6. Tubular foreign body. DETAILED DESCRIPTION

[0047] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0048] Example

[0049] Combination Figure 1 The present embodiment provides a slender tube foreign body removal device, comprising a capture rod 1, one end of the capture rod 1 is provided with a handle 2 detachably connected thereto, and the other end is provided with a capture unit for capturing foreign bodies.

[0050] Specifically, the capture unit is a single spring mechanism 3 spirally arranged along the length direction of the capture rod 1. The spring mechanism 3 includes an inner core wire 31 and a spring wire 32 wound around its outer ring. The inner core wire 31 is spirally arranged along the end of the capture rod 1 away from the handle 2, and the inner core wire 31 and the spring wire 32 are both made of nickel-titanium memory alloy, wherein the nickel-titanium memory alloy has a shape memory effect and also has superelasticity. These characteristics enable the inner core wire 31 and the spring wire 32 to withstand large deformation without plastic deformation, and can quickly return to their original shape and maintain a certain tension after being subjected to external force.

[0051] There are at least three implementations for the design of the shape of the spring mechanism 3:

[0052] Embodiment 1, combination Figure 2The inner core wire 31 is a spiral columnar structure with a constant diameter, and its structure is easy to manufacture.

[0053] Embodiment 2, combined Figure 3 The front section of the inner core wire 31 is a spiral columnar structure with a constant diameter, and the end of the inner core wire 31 away from the capture rod 1 is provided with a spiral cone structure with a gradually decreasing diameter, and the end is closed / has an opening, and the size of the opening can also be set according to the minimum size of the foreign body, so that even smaller or soft foreign bodies can be successfully captured, thereby improving the adaptability of the retrieval device.

[0054] Embodiment 3, combined Figure 4 The inner core wire 31 is a spiral cone structure with a diameter gradually decreasing along the end away from the capture rod 1. While maintaining processing convenience, it can adapt to foreign objects of different sizes by gradually reducing the diameter. This structure can provide better flexibility and adaptability without sacrificing too much strength, and the size of the end opening can be set as needed to accommodate the smallest size of foreign objects, thereby ensuring that even very small objects can be successfully captured. The end is closed / has an opening, and the size of the opening can be set according to the smallest size of foreign objects, and it has a wide range of applications.

[0055] In general, the above embodiment 1 is more suitable for the situation where the specifications of the foreign body are compatible with the inner diameter of the spring mechanism 3, while the embodiments 2 and 3 are both suitable for the capture of a variety of different specifications and soft foreign bodies, and the adaptability is wider than that of the embodiment 1. The part of the constant diameter spiral columnar structure in the embodiment 2 provides higher structural strength and stability, and the spiral cone structure further meets the requirements of passability and flexibility. Here, the operator can select the most suitable one among the above three embodiments according to the actual application requirements.

[0056] To adapt to different clinical anatomical structures, the outer diameter of the spring mechanism 3 is set to 1mm-5mm, and the wall thickness is 1mm-1.25mm; and in Examples 2 and 3, the maximum outer diameter of the spring mechanism 3 (the end of the spring mechanism 3 close to the capture rod 1) is set to 2.5mm-5mm, the minimum outer diameter (the end of the spring mechanism 3 away from the capture rod 1) is set to 1mm-3mm, and the wall thickness is 1mm-1.25mm.

[0057] Of course, the specifications of the above-mentioned spring mechanism 3 can also be set according to other situations. Smaller outer diameters and inner diameters are suitable for small or narrow blood vessels, while larger outer diameters and inner diameters are more suitable for thicker blood vessels or situations that require greater gripping force. Through this flexible design, the trauma to the patient is reduced, making the removal process safer and more efficient.

[0058] To improve the structural strength, one implementation method is to integrally manufacture the inner core wire 31 and the catch rod 1, wherein the diameter of the catch rod 1 is larger than the diameter of the inner core wire 31, and there is a smooth transition between the two to reduce structural stress and improve structural strength.

[0059] Combination Figure 1-Figure 6 The cross-sectional shape of the spring wire 32 is circular (see Figure 1 ) or triangle (see Figure 2-Figure 5 ) or a shape with more than three sides (see Figure 6 The cross-sectional shape of the spring wire 32 is a quadrilateral, such as a rhombus, a square, or a rectangle). The removal device provides a plurality of spring wires 32 with different cross-sectional shapes, so that the operator can select according to specific usage requirements and foreign body characteristics, thereby meeting various clinical needs.

[0060] Specifically, the spring wire 32 with a circular cross-section generates less friction when contacting foreign objects, and is suitable for capturing large objects or situations where the friction requirement is not high; while a triangle or a shape with more than three sides is suitable for situations where the friction requirement is high, and can provide greater friction when contacting foreign objects, and is particularly suitable for capturing foreign objects with irregular surfaces or soft textures, because the increased friction helps to grasp the foreign objects more firmly, thereby improving the capture efficiency.

[0061] For example, when handling fragile foreign objects or foreign objects that require delicate manipulation, a circular cross-section may be preferred to reduce damage; when handling foreign objects that require high stability and gripping force, a triangular or other polygonal cross-section will be selected, and when necessary, in order to reduce the damage caused by the triangular or other polygonal cross-section spring wire 32, the corners can be designed as smooth curved surfaces.

[0062] In a more preferred implementation, the spring wire 32 has two or more different cross-sections at different positions along its length, preferably the main working part has a triangular or polygonal cross-section, and the transition part or supporting part has a circular cross-section. This variable cross-section design can achieve functional regulation and customization according to the working needs of different parts of the spring wire 32, which can not only meet the safety requirements in clinical treatment, but also cope with various types of removal difficulties.

[0063] When the retrieval device is used for retrieval of foreign bodies in a blood vessel, the operator first selects a suitable sheath tube 5 according to the size of the blood vessel, then removes the handle 2 of the retrieval device, inserts the catch rod 1 into the sheath tube 5, and after the catch rod 1 extends out of the sheath tube 5, installs the handle 2, then pulls the handle 2 to retract the spring mechanism 3 into the sheath tube 5. At this time, the spring mechanism 3 is in the sheath tube 5 as a whole and is in a straight state (see FIG. Figure 7-Figure 9 ), and the inner diameter of the spring mechanism 3 and the sheath tube 5 have good coaxiality.

[0064] When the sheath 5 reaches the grasping position, push the handle 2 to release the spring mechanism 3 (see Fig.10 ), and finally pull the spring mechanism 3 out of the blood vessel, and rely on the self-binding property of the spring mechanism 3 to bind the foreign matter in the blood vessel and take it out of the blood vessel.

[0065] In this embodiment, since the inner core wire 31 and the spring wire 32 of the spring mechanism 3 are made of nickel-titanium memory alloy with shape memory effect and superelasticity, the spring mechanism 3 can quickly return to its original shape and maintain a certain tension after being acted upon by an external force. Therefore, the operator can quickly restrain the foreign object and it is not easy to loosen during the outward pulling process.

[0066] In addition, when the spring mechanism 3 is retracted into or pushed out of the sheath tube 5, the portion located inside the sheath tube 5 will become straight, while the portion located outside the sheath tube 5 remains in a working state. This design enables the spring mechanism 3 to be smoothly retracted into and pushed out of the sheath tube 5 each time, avoiding malfunctions and thus improving work efficiency.

[0067] Combination Fig.11 and Fig.12 As for the capture of tubular foreign bodies 6, since the single spirally arranged spring mechanism 3 of the retrieval device has a multi-turn spring structure, the spring mechanism 3 can capture the tubular foreign bodies 6 from multiple angles, and is also very suitable for capturing broken tubular foreign bodies 6 such as catheters.

[0068] The present invention also provides a method for manufacturing the above-mentioned slender tube foreign body removal device, Figure 2 and Figure 5 And for example 1, it includes the following steps:

[0069] First, the spring mechanism 3 is prepared, the spring wire 32 is wound into a straight spring tube 4, wherein the inner diameter of the spring tube 4 matches the outer diameter of the inner core wire 31, and finally, the inner core wire 31 and the spring tube 4 are assembled into one body (see Figure 5 ), and installed on the heat setting tooling for heat setting treatment.

[0070] It should be noted that the above-mentioned heat setting tool is designed according to the shape of the spring mechanism 3 required. For this embodiment 1, for example, the heat setting tool is configured as follows: The heat setting tool includes a Figure 2 ) is a mold block that matches the internal specifications of the spring mechanism 3 shown in FIG. After the inner core wire 31 and the spring tube 4 are assembled into one, it is wound around the outer ring of the mold block, and then placed in a space with a certain temperature for heat setting treatment together with the mold block. Finally, the spring mechanism 3 is removed from the mold block, and finally the spring mechanism 3 is obtained as shown in FIG. Figure 2In the spring mechanism 3 shown, the mold block is made of heat-resistant alloy steel, high-speed steel or hard alloy, etc. These materials can meet the requirements of heat resistance, wear resistance and strength of the mold block during the heat setting process.

[0071] In another preferred embodiment, the spring mechanism 3 in Example 1, Example 2, and Example 3 of the present invention may have different shape memory properties (such as phase change temperature points) at different locations along the length direction to adapt to more precise regulation in clinical applications. To this end, during production, different locations of the spring wire 32 may be processed to have different shape memory properties by first controlling the composition gradient or performing differential heat treatment, so that the spring wire 32 has differentiated shape memory properties along the length direction of the spring tube 4 after being wound into a straight spring tube 4. Different locations of the inner core wire 31 may also be processed to have different shape memory properties by first controlling the composition gradient or performing differential heat treatment. In some cases, the spring tube 4 and the inner core wire 31 may further have different shape memory properties even in the corresponding local sections at the same position, thereby achieving more precise fine-tuning of the clamping performance of the spring mechanism 3 and adapting to more complex foreign bodies.

[0072] After the spring mechanism 3 is prepared, the prepared spring mechanism 3 can be used as a capture unit and assembled and connected with other components to finally obtain a slender tube foreign body removal device.

Claims

1. A slender tube foreign body removal device, characterized in that: It comprises a capture rod (1), one end of which is provided with a handle (2) detachably connected thereto, and the other end of which is provided with a capture unit for capturing foreign matter; The capture unit is a single spring mechanism (3) spirally arranged along the length direction of the capture rod (1); The spring mechanism (3) comprises an inner core wire (31) and a spring wire (32) wound around its outer ring, the inner core wire (31) being spirally arranged along one end of the catch rod (1) away from the handle (2), and the inner core wire (31) and the spring wire (32) are both made of nickel-titanium memory alloy.

2. A slender tube foreign body removal device as claimed in claim 1, characterized in that: The inner core wire (31) is a spiral columnar structure with a constant diameter.

3. A slender tube foreign body removal device as claimed in claim 2, characterized in that: The end of the inner core wire (31) facing away from the capture rod (1) is provided with a spiral cone structure with a gradually decreasing diameter.

4. The slender tube foreign body removal device according to claim 1, characterized in that: The inner core wire (31) is a spiral cone-shaped structure with a diameter gradually decreasing as it moves away from the capture rod (1).

5. The slender tube foreign body removal device according to claim 1, characterized in that: The cross-sectional shape of the spring wire (32) is circular.

6. The slender tube foreign body removal device according to claim 1, characterized in that: The cross-sectional shape of the spring wire (32) is a triangle / a shape having more than three sides.

7. The slender tube foreign body removal device according to claim 1, characterized in that: The outer diameter of the spring mechanism (3) is 1 mm-5 mm, and the wall thickness is 1 mm-1.25 mm.

8. The slender tube foreign body removal device according to claim 1, characterized in that: The inner core wire (31) and the capture rod (1) are integrally manufactured and formed.

9. The slender tube foreign body removal device according to claim 8, characterized in that: The diameter of the capture rod (1) is greater than the diameter of the inner core wire (31).

10. A method for manufacturing a slender tube foreign body removal device according to any one of claims 1 to 9, characterized in that: The steps include: S1. Preparation of spring mechanism: First, the spring wire (32) is wound into a straight spring tube (4), wherein the inner diameter of the spring tube (4) matches the outer diameter of the inner core wire (31); Finally, the inner core wire (31) and the spring tube (4) are assembled into one body and installed on a heat setting tool to perform heat setting treatment; S2, assembly: the spring mechanism (3) prepared in step S1 is used as a capture unit, and is assembled and connected with other components to obtain a slender tube foreign body removal device.

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