Automatic flat-head net basket locking mechanism and net basket guide pipe

Abstract

The invention discloses an automatic flat-head mesh basket locking mechanism and a mesh basket catheter, and relates to the technical field of medical instruments.The locking mechanism comprises a special-shaped pipe, a built-in pipe, a plug pin piece and an elastic locking piece, one end of the built-in pipe is inserted into the special-shaped pipe in a penetrating mode, and a gap used for clamping the far end of a nickel-titanium sheet is formed between one end of the special-shaped pipe and the built-in pipe; the other end is attached and fixedly connected with the built-in pipe; the elastic locking piece is arranged in the built-in pipe, and the plug pin piece is used for being inserted into the built-in pipe and extruding the elastic locking piece. After the end of the nickel-titanium sheet of the net basket is inserted between the special-shaped pipe and the built-in pipe, the plug pin piece is inserted into the built-in pipe, and in the inserting process of the plug pin piece, the end of the plug pin piece slides the pin shaft under the extrusion action of the extrusion slope, so that the sliding pin shaft slides along the chute and compresses the elastic piece; therefore, the sliding pin shaft can generate radial extrusion force on the plug pin piece through resilience force of the elastic piece, the plug pin piece can be locked conveniently, and therefore it is guaranteed that the end of the nickel-titanium sheet is locked.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a flat head basket automatic locking mechanism and a basket catheter. Background Art

[0002] In recent years, catheter treatment has been widely used in the treatment of various diseases. For example, inside the patient's heart or vein, once the catheter reaches the expected position, treatment can be carried out through corresponding techniques. And the distal end of the catheter used in the prior art is designed in various different forms, and the flat head basket catheter is one of the forms.

[0003] In the prior art, the basket of the basket catheter is generally cut from nitinol wire or nitinol sheet, and the nitinol wire or nitinol sheet at the distal end of the basket is generally adhesively fixed by a head-end metal column through gluing.

[0004] The deficiencies of the existing nitinol sheet fixing structure of the flat head basket are as follows: After the nitinol sheet of the existing basket catheter is adhesively fixed by gluing, since it will be soaked in blood during use, it is easy to cause the glue to fail, which will cause the parts to loosen and enter the human body, thus having a huge impact on life and health. Summary of the Invention

[0005] The purpose of the present invention is to provide a flat head basket automatic locking mechanism and a basket catheter to solve the technical problem that the end of the nitinol sheet of the flat head basket in the prior art is easily glued and fixed, which is likely to fail and fall off, posing a danger to patients.

[0006] The technical problem to be solved by the present invention can be achieved through the following technical solutions:

[0007] A flat head basket automatic locking mechanism includes:

[0008] A special-shaped tube and an inner tube, one end of the inner tube is inserted into the special-shaped tube, and a gap for clamping the distal end of the nitinol sheet is provided between one end of the special-shaped tube and the inner tube, and the other end is fixedly connected to the inner tube in a fitting manner;

[0009] A plug member and an elastic locking member, the elastic locking member is arranged inside the inner tube, the plug member is used for inserting into the inner tube and squeezing the elastic locking member, the elastic locking member is used for generating a radial squeezing force on the plug member inserted into the inner tube, and one end of the plug member and the inner wall of the special-shaped tube jointly clamp the distal end of the nitinol sheet.

[0010] Preferably, the special-shaped tube includes a thick-walled section and a thin-walled section, the inner diameter of the thick-walled section is equal to the outer diameter of the inner tube, and the thick-walled section is fixedly connected to the inner tube, the inner diameter of the thin-walled section is smaller than the outer diameter of the inner tube, and the edge of the thin-walled section far from the thick-walled section exceeds the edge of the inner tube.

[0011] Preferably, the plug member includes a plug rod and a pressing head. The plug rod is used to be inserted into the inner tube, and the pressing head is fixedly connected to one end of the plug rod. The pressing head cooperates with the special-shaped tube to clamp the distal end of the nitinol sheet.

[0012] Preferably, the pressing head includes a positioning plug. The diameter of the positioning plug is larger than that of the plug rod, and the outer diameter of the positioning plug is equal to the inner diameter of the inner tube. An outward convex body is provided on the side of the positioning plug away from the plug rod. The outer diameter of the outward convex body is larger than the outer diameter of the inner tube and smaller than the inner diameter of the thin-walled section.

[0013] Preferably, the elastic locking mechanism includes an inclined groove, a sliding pin shaft, an elastic member, and a positioning block. The positioning block is fixedly arranged in the inner tube. The inclined groove is opened on the inner wall of the inner tube. The sliding pin shaft is slidably connected in the inclined groove, and the elastic member is arranged between the sliding pin shaft and the positioning block.

[0014] Preferably, the end of the plug member for inserting into the inner tube is provided with a pressing inclined surface that cooperates with the sliding pin shaft.

[0015] Preferably, a spiral groove is provided on the outer wall of the plug member, and a card slot distributed radially along the plug member is provided on the side of the spiral groove away from the pressing inclined surface. Both the card slot and the spiral groove cooperate with the sliding pin shaft.

[0016] Preferably, the elastic member is a special-shaped spiral spring. The elastic member includes a large-loop part and a small-loop part, which are alternately distributed. The large-loop part is attached to the inner wall of the inner tube, and the small-loop part is attached to the outer wall of the plug member.

[0017] Preferably, a through hole for the plug member to pass through is opened on the positioning block, and a conical guide groove concentric with the through hole is opened on the side of the positioning block close to the elastic member. The conical guide groove facilitates guiding the end of the plug member to insert into the through hole.

[0018] Advantages of the present invention:

[0019] 1. After the distal end of the nitinol sheet of the basket of the present invention is inserted between the special-shaped tube and the inner tube, the plug member is inserted into the inner tube. After the plug member is inserted in place, the pressing head on the plug member relies on the outward convex body provided to jointly clamp the distal end of the nitinol sheet with the thin-walled section of the special-shaped tube. And during the insertion process of the plug member, its end presses the sliding pin shaft by the action of the pressing inclined surface, so that the sliding pin shaft slides along the inclined groove and compresses the elastic member. Thus, it is convenient to rely on the resilience of the elastic member to make the sliding pin shaft generate a radial pressing force on the plug member, which is convenient to lock the plug member, so as to ensure that the distal end of the nitinol sheet is locked and prevent it from falling off.

[0020] 2. The spiral grooves and radially distributed slots on the latch of the present invention can effectively prevent the sliding pin shaft and the latch from slipping, that is, prevent the latch from slipping out due to overall vibration, movement, bumps, etc.

[0021] 3. The elastic member of the present invention is a special-shaped coil spring, which includes alternating large coil parts and small coil parts, which is beneficial to reduce the distortion of the elastic member caused by compression, resulting in uneven elastic force and thus affecting the locking of the latch part; avoiding the occurrence of uneven self-locking force. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0024] Figure 3 yes Figure 1 A schematic diagram of the enlarged structure at B in the middle;

[0025] Figure 4 It is a structural schematic diagram of the relative position distribution of the chute and the built-in pipe in the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the sliding pin and the inclined groove in the present invention;

[0027] Figure 6 It is a structural schematic diagram of the latch member in the present invention;

[0028] Figure 7 It is a schematic diagram of the state before the latch member of the present invention is inserted into the interior of the built-in tube;

[0029] Figure 8 It is a schematic diagram of the state when the extrusion inclined surface at the end of the latch member in the present invention begins to contact the sliding pin shaft;

[0030] Figure 9 It is a schematic diagram of the state when the latch member of the present invention relies on the extrusion inclined surface to squeeze the sliding pin shaft.

[0031] Description of reference numerals:

[0032] 1. NiTi sheet; 2. PEEK tube; 3. Restraint ring; 4. Inner support sleeve; 5. Special-shaped tube; 51. Thick-walled section; 52. Thin-walled section; 6. Internal tube; 7. Balloon; 8. Latch; 81. Positioning plug; 82. Insert rod; 83. Spiral groove; 84. Slot; 85. Extrusion slope; 86. External protrusion; 9. Sliding pin; 10. Elastic part; 11. Positioning block; 12. Bevel groove; 13. Perforation; 14. Conical guide groove. DETAILED DESCRIPTION

[0033] The following is a detailed description of the specific embodiments of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0034] As Figures 1-9 shown, a flat head basket automatic locking mechanism is used to lock the end of the nitinol sheet 1 in the basket structure of a medical flat head basket catheter. The basket structure includes a plurality of circumferentially distributed nitinol sheets 1, and both ends of the nitinol sheet 1 need to be locked. The locking mechanism includes a special-shaped tube 5, an inner tube 6, a plug member 8, and an elastic locking member. One end of the inner tube 6 is inserted into the special-shaped tube 5, and a gap for placing the distal end of the nitinol sheet 1 is provided between one end of the special-shaped tube 5 and the inner tube 6, and the other end is fixedly connected to the inner tube 6 in a fitting manner.

[0035] The elastic locking member is arranged inside the inner tube 6. The plug member 8 is used to be inserted into the inner tube 6 and squeeze the elastic locking member. The elastic locking member is used to generate a radial squeezing force on the plug member 8 inserted into the inner tube 6 to prevent the inserted plug member 8 from disengaging from the inner tube 6. One end of the plug member 8 and the inner wall of the special-shaped tube 5 jointly clamp the distal end of the nitinol sheet 1.

[0036] In some specific embodiments, the special-shaped tube 5 includes a thick-walled section 51 and a thin-walled section 52. The inner diameter of the thick-walled section 51 is equal to the outer diameter of the inner tube 6, and the thick-walled section 51 is fixedly connected to the inner tube 6. The inner diameter of the thin-walled section 52 is smaller than the outer diameter of the inner tube 6, and the edge of the thin-walled section 52 away from the thick-walled section 51 extends beyond the edge of the inner tube 6, that is, the two are not aligned. The end of the inner tube 6 is located inside the thin-walled section 52. In this way, it is convenient to have a gap for inserting the distal end of the nitinol sheet 1 between the end of the inner tube 6 and the thin-walled section 52. At the same time, because the edge of the inner tube 6 is shorter than the edge position of the thin-walled section 52, it is convenient to press the nitinol sheet 1 against the thin-walled section 52 by the end of the plug member 8.

[0037] In some specific embodiments, referring to Figure 6 shown, the plug member 8 includes a plug rod 82 and a pressing head. The plug rod 82 is used to be inserted into the inner tube 6, and the pressing head is fixedly connected to one end of the plug rod 82. Both are cylinders, and the pressing head and the special-shaped tube 5 cooperate to clamp the distal end of the nitinol sheet 1.

[0038] Among them, the pressing head includes a positioning plug 81. The diameter of the positioning plug 81 is larger than the diameter of the plug rod 82. The outer diameter of the positioning plug 81 is equal to the inner diameter of the inner tube 6, and the two are adapted and fitted. An outer convex body 86 is provided on the side of the positioning plug 81 away from the plug rod 82. The outer diameter of the outer convex body 86 is larger than the outer diameter of the inner tube 6. Here, it can be slightly larger, and specifically can be set based on the thickness of the nitinol sheet 1. And the outer diameter of the outer convex body 86 is smaller than the inner diameter of the thin-walled section 52.

[0039] After the distal end of the nitinol sheet 1 is inserted between the thin-walled section 52 of the special-shaped tube 5 and the inner tube 6 to achieve preliminary positioning, the pin member 8 is inserted into the inner tube 6. The positioning plug 81 of the pin member 8 is inserted into the inner tube 6 in cooperation, and the convex body 86 on the positioning plug 81 abuts against the end of the inner tube 6 and stops. Since the outer diameter of the convex body 86 is larger than the outer diameter of the inner tube 6 and smaller than the inner diameter of the thin-walled section 52 of the special-shaped tube 5, the nitinol sheet 1 inserted can be extruded, and the nitinol sheet 1 can be extruded and deformed to a certain extent, so as to be easily pressed tightly by the convex body 86.

[0040] In some specific embodiments, referring to Figure 7 As shown, the elastic locking mechanism includes an inclined groove 12, a sliding pin shaft 9, an elastic member 10 and a positioning block 11. The positioning block 11 is fixedly arranged in the inner tube 6. The inclined groove 12 is opened on the inner wall of the inner tube 6 and there are two of them, which are distributed in pairs on both sides of the inner tube 6. The sliding pin shaft 9 is slidably connected in the inclined groove 12 and straddles between the two inclined grooves 12. The elastic member 10 is arranged between the sliding pin shaft 9 and the positioning block 11. It should be noted that the initial position of the sliding pin shaft 9 is close to the position where the central axis of the inner tube 6 is located.

[0041] When the pin member 8 is inserted into the inner tube 6, the end of the pin member 8 contacts and presses the sliding pin shaft 9, causing the sliding pin shaft 9 to slide along the inclined groove 12, and the sliding pin shaft 9 compresses the elastic member 10. When the pin member 8 is inserted to the position where the positioning block 11 is located, it is just inserted in place. At this time, due to the resilience of the elastic member 10 pushing the sliding pin shaft 9, the sliding pin shaft 9 generates a radial extrusion force on the pin member 8, realizing the locking of the pin member 8 and preventing it from disengaging during the use of the basket catheter.

[0042] In some specific embodiments, the end of the pin member 8 for inserting into the inner tube 6 is provided with an extrusion inclined surface 85 that cooperates with the sliding pin shaft 9. During the insertion of the pin member 8, the extrusion inclined surface 85 at its end contacts the sliding pin shaft 9 and performs extrusion, facilitating the extrusion of the sliding pin shaft 9 to slide along the inclined groove 12.

[0043] In some specific embodiments, in order to prevent the sliding pin 9 and the latch member 8 from slipping off, a spiral groove 83 is provided on the outer wall of the latch member 8, and a groove 84 distributed radially along the latch member 8 is provided on the side of the spiral groove 83 away from the extrusion inclined surface 85. The groove 84 and the spiral groove 83 both cooperate with the sliding pin 9. During the process of the latch member 8 being inserted into the built-in tube 6, and after the sliding pin 9 is squeezed along the inclined groove 12 by the extrusion inclined surface 85 for a certain distance, as the latch member 8 continues to go deeper, the spiral groove 83 contacts the sliding pin 9. At this time, in order to avoid obstruction, the latch member 8 can be rotated and kept moving forward until the sliding pin 9 is stuck in the groove 84. By providing the spiral groove 83 and the groove 84, the latch member 8 can be better in contact with the sliding pin 9 to prevent slipping off. At the same time, the groove 84 at the end of the spiral groove 83 can prevent the latch member 8 from slipping out due to overall vibration, movement, bumps, etc.

[0044] In some specific embodiments, reference Figure 7 As shown, the elastic member 10 is a special-shaped coil spring, and the elastic member 10 includes a large circle part and a small circle part, which are alternately distributed. The large circle part fits the inner wall of the built-in tube 6, and the small circle part fits the outer wall of the latch member 8. This design is beneficial to reducing the distortion of the elastic member 10 caused by compression, resulting in uneven elastic force and thus affecting the locking of the latch member 8; avoiding the occurrence of uneven self-locking force.

[0045] In some specific embodiments, a through hole 13 for the latch member 8 to pass through is formed on the positioning block 11, and a conical guide groove 14 concentrically distributed with the through hole 13 is formed on the side of the positioning block 11 close to the elastic member 10, so that the conical guide groove 14 facilitates guiding the end of the latch member 8 to be inserted into the through hole 13.

[0046] In other specific embodiments, reference Figure 3 As shown, the automatic locking mechanism of the flat-headed basket also includes a fixing mechanism for fixing the proximal end of the nickel-titanium sheet 1, the fixing mechanism includes a restraining ring 3 and an inner support sleeve 4, the inner support sleeve 4 is inserted in the restraining ring 3, and the proximal end of the nickel-titanium sheet 1 is inserted between the restraining ring 3 and the inner support sleeve 4, the outer diameter of one end of the inner support sleeve 4 gradually increases, and the outer diameter of the other end remains unchanged. The end with a reduced diameter is clamped and locked with the restraining ring 3 on the outside to prevent the nickel-titanium sheet 1 from being pulled out.

[0047] It should be noted that epoxy glue can be injected between the restraining ring 3 and the inner support sleeve 4 for further fixation, and epoxy glue can also be injected into the gap between the special-shaped tube 5 and the built-in tube 6 for further fixation to ensure that the nickel-titanium sheet 1 will not fall off.

[0048] A basket catheter may include the automatic locking mechanism of any of the above-mentioned embodiments, and also includes a balloon 7 and a PEEK tube 2. The balloon 7 is fixedly sleeved on the outside of the built-in tube 6 and is on one side of the special-shaped tube 5. The PEEK tube 2 is a polyetheretherketone material tube, which is tightly attached to the inside of the built-in tube 6 and supports the positioning block 11. The PEEK tube 2 slides through the inner support sleeve 4, that is, the inner support sleeve 4 can slide relative to the PEEK tube 2, thereby facilitating the storage or expansion of the flat-head basket composed of nickel-titanium sheets 1.

[0049] In order to facilitate the understanding of the embodiments of this solution by those skilled in the art, the working principle of this solution is briefly described in combination with specific application scenarios:

[0050] First, the proximal end of the nickel-titanium sheet 1 constituting the basket structure is inserted circumferentially between the restraining ring 3 and the inner support sleeve 4, and the end of the inner support sleeve 4 with a reduced diameter is clamped and locked with the restraining ring 3; then the distal end of the nickel-titanium sheet 1 is inserted into the gap between the inner tube 6 and the special-shaped tube 5;

[0051] Then, the latch member 8 is inserted into the built-in tube 6, and the positioning plug 81 of the latch member 8 is inserted into the built-in tube 6, and the outer protrusion 86 on the positioning plug 81 stops when it contacts the end of the built-in tube 6. Since the outer diameter of the outer protrusion 86 is larger than the outer diameter of the built-in tube 6 and smaller than the inner diameter of the thin-walled section 52 of the special-shaped tube 5, it can produce an extrusion effect on the inserted nickel-titanium sheet 1, and the nickel-titanium sheet 1 can be squeezed and deformed to a certain extent, so that it is easy to be pressed by the outer protrusion 86;

[0052] And during the process of inserting the latch member 8 into the built-in tube 6, the end of the latch member 8 relies on the extrusion inclined surface 85 to contact and extrude the sliding pin shaft 9, causing the sliding pin shaft 9 to slide along the inclined groove 12, and the sliding pin shaft 9 compresses the elastic member 10. When the latch member 8 is inserted to the position of the positioning block 11, it is just inserted into place. At this time, the elastic member 10 pushes the sliding pin shaft 9 due to its rebound force, so that the sliding pin shaft 9 generates a radial extrusion force on the latch member 8, thereby automatically locking the latch member 8 to prevent it from detaching during the use of the basket catheter, thereby preventing the end of the nickel-titanium sheet 1 from falling off.

[0053] And when the latch member 8 is inserted into the built-in tube 6 and inserted into place, the sliding pin shaft 9 is just stuck in the slot 84. By providing the spiral groove 83 and the slot 84, the latch member 8 can be better in contact with the sliding pin shaft 9 to prevent slipping. At the same time, the slot 84 at the end of the spiral groove 83 can prevent the latch member 8 from slipping out due to overall vibration, movement, bumps, etc.

[0054] At the same time, the elastic member 10 is a special-shaped helical spring, which is composed of large and small coil parts distributed alternately, which is beneficial to reduce the distortion of the elastic member 10 caused by compression, resulting in uneven elastic force and thus affecting the locking of the latch member 8; avoiding the occurrence of uneven self-locking force.

[0055] The above discloses only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art shall fall within the protection scope of the present invention.

Claims

1. An automatic locking mechanism for a flat-head basket, characterized in that: include: A special-shaped tube (5) and an internal tube (6), wherein one end of the internal tube (6) is inserted into the special-shaped tube (5), and a gap for clamping the distal end of the nickel-titanium sheet (1) is provided between one end of the special-shaped tube (5) and the internal tube (6), and the other end is fitted and fixedly connected to the internal tube (6); A latch member (8) and an elastic locking member, wherein the elastic locking member is arranged inside the built-in tube (6), the latch member (8) is used to be inserted into the built-in tube (6) and to squeeze the elastic locking member, and the elastic locking member is used to generate a radial squeezing force on the latch member (8) inserted into the built-in tube (6), and one end of the latch member (8) and the inner wall of the special-shaped tube (5) jointly clamp the distal end of the nickel-titanium sheet (1).

2. The automatic locking mechanism of a flat-head basket according to claim 1, characterized in that: The special-shaped tube (5) comprises a thick-walled section (51) and a thin-walled section (52); the inner diameter of the thick-walled section (51) is equal to the outer diameter of the built-in tube (6), and the thick-walled section (51) is fixedly connected to the built-in tube (6); the inner diameter of the thin-walled section (52) is smaller than the outer diameter of the built-in tube (6), and the edge of one side of the thin-walled section (52) away from the thick-walled section (51) exceeds the edge of the built-in tube (6).

3. The automatic locking mechanism of a flat-head basket according to claim 2, characterized in that: The latch member (8) comprises an insertion rod (82) and an extrusion head, wherein the insertion rod (82) is used to be inserted into the built-in tube (6), and the extrusion head is fixedly connected to one end of the insertion rod (82), and the extrusion head cooperates with the special-shaped tube (5) to clamp the distal end of the nickel-titanium sheet (1).

4. The automatic locking mechanism for a flat-head basket according to claim 3, characterized in that: The extrusion head comprises a positioning plug (81), the diameter of the positioning plug (81) is greater than the diameter of the insertion rod (82), the outer diameter of the positioning plug (81) is equal to the inner diameter of the built-in tube (6), and an outer protrusion (86) is provided on the side of the positioning plug (81) away from the insertion rod (82), the outer diameter of the outer protrusion (86) is greater than the outer diameter of the built-in tube (6), and the outer diameter of the outer protrusion (86) is smaller than the inner diameter of the thin-walled section (52).

5. The automatic locking mechanism for a flat-head basket according to claim 1, characterized in that: The elastic locking mechanism comprises an inclined groove (12), a sliding pin shaft (9), an elastic member (10) and a positioning block (11); the positioning block (11) is fixedly arranged in the built-in tube (6); the inclined groove (12) is formed on the inner wall of the built-in tube (6); the sliding pin shaft (9) is slidably connected in the inclined groove (12); and the elastic member (10) is arranged between the sliding pin shaft (9) and the positioning block (11).

6. The automatic locking mechanism for a flat-head basket according to claim 5, characterized in that: One end of the latch member (8) used for inserting into the built-in tube (6) is provided with an extrusion slope (85) matched with the sliding pin shaft (9).

7. The automatic locking mechanism for a flat-head basket according to claim 5, characterized in that: A spiral groove (83) is provided on the outer wall of the latch member (8), and a clamping groove (84) distributed radially along the latch member (8) is provided on the side of the spiral groove (83) away from the extrusion inclined surface (85), and the clamping groove (84) and the spiral groove (83) are both matched with the sliding pin shaft (9).

8. The automatic locking mechanism for a flat-head basket according to claim 5, characterized in that: The elastic member (10) is a special-shaped coil spring, comprising a large coil portion and a small coil portion, the large coil portion and the small coil portion are alternately distributed, the large coil portion is attached to the inner wall of the built-in tube (6), and the small coil portion is attached to the outer wall of the latch member (8).

9. The automatic locking mechanism for a flat-head basket according to claim 5, characterized in that: The positioning block (11) is provided with a through hole (13) for the latch member (8) to pass through, and a tapered guide groove (14) coaxially distributed with the through hole (13) is provided on a side of the positioning block (11) close to the elastic member (10), and the tapered guide groove (14) is used to guide the end of the latch member (8) to be inserted into the through hole (13).

10. A basket catheter, characterized in that: It comprises an automatic locking mechanism for a flat-head mesh basket as described in any one of claims 1 to 9.

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