A balloon dilatation catheter

Abstract

The present invention relates to a balloon dilatation catheter, which includes a double-layer balloon assembly and a drill bit assembly. The double-layer balloon assembly includes an inner tube, an outer tube sleeved outside the inner tube, an outer balloon arranged at the distal end of the outer tube, and an inner balloon arranged at the distal end of the inner tube. The inner balloon is located in the outer balloon, and the distal ends of the inner balloon and the outer balloon are provided with end covers that can be opened and closed; the drill bit assembly includes a movable catheter and a drill bit structure arranged at the distal end of the movable catheter, the movable catheter is inserted in the inner tube, and the balloon dilatation catheter has a first working state and a second working state. In the first working state, the drill bit structure is located in the inner balloon and the end cover is closed; in the second working state, at least part of the drill bit structure is located outside the distal end of the inner balloon and the end cover is open; the balloon dilatation catheter is switched between the first working state and the second working state by operating the movable catheter, and the drill bit structure can extend from the distal end of the inner balloon to perform in-depth drilling on thrombus tissue.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a balloon dilatation catheter. Background Art

[0002] Balloon dilatation catheters are interventional devices used to treat thrombotic blockages in peripheral blood vessels, dredge blood vessels, and dilate vascular channels. Existing balloon dilatation catheters are used by guiding the balloon over a guidewire until it reaches the lesion site for balloon dilation. However, when dealing with a large amount of clogged tissue within a vessel, the guidewire's invasive capabilities are poor, resulting in the guidewire failing to pass through the clogged tissue, or even failing to pass the balloon after the guidewire has passed through the clogged tissue. Summary of the Invention

[0003] The purpose of the present invention is to provide a new type of balloon dilatation catheter, which has a double-balloon structure and a drill structure is provided in the inner balloon. The distal end of the inner balloon can be opened, and the drill structure can be extended from the distal end of the inner balloon to realize the distal drilling function.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A balloon dilatation catheter, comprising:

[0006] A double-layer balloon assembly, comprising an inner tube, an outer tube sleeved outside the inner tube, an outer balloon disposed at the distal end of the outer tube, and an inner balloon disposed at the distal end of the inner tube, the inner balloon being located within the outer balloon, a filling cavity being formed between the outer side wall of the inner balloon and the inner side wall of the outer balloon, an annular channel being formed between the outer side wall of the inner tube and the inner side wall of the outer tube and communicating with the filling cavity for transporting liquid and / or gas into the filling cavity, the distal ends of the inner balloon and the outer balloon being provided with openable and closable end caps, and the distal ends of the outer balloon and the inner balloon being sealed and connected;

[0007] A drill bit assembly comprises a movable guide tube and a drill bit structure arranged at the distal end of the movable guide tube, wherein the movable guide tube is movably inserted into the inner tube.

[0008] The balloon dilatation catheter has a first working state and a second working state. When the balloon dilatation catheter is in the first working state, the drill bit structure is located in the inner balloon and the end cover is closed. When the balloon dilatation catheter is in the second working state, at least part of the drill bit structure is located outside the distal end of the inner balloon and the end cover is open.

[0009] The balloon dilatation catheter is switched between the first working state and the second working state by operating the movable catheter.

[0010] Furthermore, the end cover includes an annular seat and a conical cap arranged on the annular seat, the distal end of the outer balloon and the distal end of the inner balloon are respectively fixedly connected to the annular seat, and the conical cap is composed of multiple magnetic cover bodies connected by magnetic attraction. The cover body is integrally formed with the annular seat and the cover body is flippable. The cover body is provided with a magnetic sheet, and the outer diameter of the conical cap gradually decreases from the annular seat toward the direction away from the inner balloon.

[0011] In an embodiment of the present invention, the inner and outer balloons have substantially the same structure, with their inner diameters gradually increasing and then remaining constant from the proximal end to the distal end, resembling a transverse U-shaped structure. The outer edge of the annular seat is fixedly connected to the distal end of the outer balloon, while the inner edge of the annular seat is fixedly connected to the distal end of the inner balloon, thereby sealing the distal ends of the outer and inner balloons.

[0012] In an embodiment of the present invention, the axes of the inner balloon, the outer balloon, the outer tube, the inner tube, the movable catheter, and the end cap coincide with each other.

[0013] In an embodiment of the present invention, the filled punching space between the inner balloon and the outer balloon can be used to inject a mixed solution of injection water and developer. The internal space of the inner balloon is used to accommodate a drill bit.

[0014] Furthermore, the number of the cover bodies is 3 to 5, and the distal end of the cover body is a silicone head provided with a magnetic sheet.

[0015] According to some specific embodiments, the number of the covers is 4. The end cap at the distal end of the double balloon structure is designed with open petals, and the conical cap is divided into four petals. When the micro drill structure is extended by thrust, the end cap is pushed open until the drill is fully retracted and then closed again.

[0016] Furthermore, the drill bit structure has magnetic properties that repel the magnetic properties of the cover body.

[0017] Furthermore, the drill bit structure is a spiral sheet wound around the outer periphery of the distal end of the movable catheter and extending axially along the movable catheter, and the outer diameter of the spiral sheet gradually increases from the distal end to the proximal end of the movable catheter.

[0018] Furthermore, the axial length of the spiral sheet is 1 / 3 to 2 / 3 of the axial length of the inner balloon.

[0019] Furthermore, the distal end of the spiral sheet and / or the movable guide tube has magnetism that repels the magnetism of the cover.

[0020] In an embodiment of the present invention, the inner balloon and the outer balloon can be made using conventional balloon inflation processes, which are not described in detail in the present invention. Nylon is preferably used. For example, in one embodiment, two independent balloons can be produced: an inner balloon with a diameter of 2.5 mm and an outer balloon with an outer diameter of 4 mm (the diameter of the balloon refers to the diameter of the middle part of the spindle-shaped balloon after expansion). The surface of the inner balloon is then reinforced with fabric to improve its compliance. After processing, the proximal end of the inner balloon is docked with the distal end of the inner tube; at the same time, the proximal end of the outer balloon is docked with the distal end of the outer tube, and the outer surface of the outer balloon is then reinforced with fabric. The fabric reinforcement adopts a conventional woven balloon process, using a webbing made of polytetraethylene and polyurethane to grid-cover the balloon surface. Laser welding is used for docking (welding conditions that can be used include: spot size 1-2 mm, rotation speed 100-300 rpm, energy controlled at about 800 mW and duration of 25 seconds for circumferential welding). After welding, the distal end of the inner balloon and the distal end of the outer balloon are cut off as needed to form a U-shaped structure. The inner tube is inserted into the outer tube, the inner balloon is inserted into the outer balloon, and then the distal ends of the inner balloon and the outer balloon are connected to the end caps respectively.

[0021] In an embodiment of the present invention, the distal end of the inner balloon is first fixedly connected to the inner edge of the annular seat, and then the distal end of the outer balloon is fixedly connected to the outer edge of the annular seat. Specifically, the end cap is put on the cylindrical tooling, the inner balloon is partially pulled out from the outer balloon, glue is applied to the distal end of the inner balloon and / or the inner edge of the annular seat, the distal end of the inner balloon and the inner edge of the annular seat are butted together, and then light-cured. The tooling is a cylindrical transparent glass tube. During light-curing, ultraviolet light is inserted into the glass tube and cured from the inside to the adhesive portion. After the curing is completed, glue is applied to the distal end of the outer balloon and / or the outer edge of the annular seat, the distal end of the outer balloon and the outer edge of the annular seat are butted together, and then light-cured. The ultraviolet light can be irradiated from the outside. After curing, the outer surface of the outer balloon can be reinforced with fabric.

[0022] In an embodiment of the present invention, the annular seat of the end cap and the multiple cap bodies are integrally formed using a drop molding process. The mold is heated to 110°C and sprayed with a release agent. The head molding area of ​​the base portion of the high-temperature mold is immersed in molten polyurethane plastic liquid. After standing for 10±2 seconds, it is slowly removed and placed in a horizontal fixture, where it rotates parallel to the horizontal plane at a speed of 0.5 revolutions per second. The base mold is naturally cooled to 90±5°C. After rotation stops, the upper mold is closed and pressure is increased to 15±2 Newtons (pressure can control thickness). The mold continues to rotate until it cools naturally. After removing excess flash after extrusion, the distal taper is manually peeled off, and the mold is placed in a contoured jig and baked at 50°C for half an hour. Fabric reinforcement can also be applied to the outer surface of the end cap. A groove is provided on the inner side of the silicone head. A soft magnetic disk is embedded in the groove and attached by curing glue, with the magnetic disk's north pole facing inward and its south pole facing outward. The silicone head with the embedded magnetic disk is then glued to the inner side of the distal end of the end cap.

[0023] Furthermore, the movable catheter is provided with a guide wire channel extending from the proximal end to the distal end thereof and open at both ends for the guide wire to pass through, and the balloon dilatation catheter also includes a guide wire.

[0024] Furthermore, the guide wire has magnetism that is attracted to the magnetism of the cover body. After the guide wire is inserted, the cover body can be closed and adsorbed onto the guide wire by relying on the magnetic force, thereby further improving the stability during closure.

[0025] In an embodiment of the present invention, the guide wire is replaced by conventional 304 stainless steel with a flexible ferrite 444 stainless steel, so that the guide wire can be attracted by the magnetic sheet on the cover body, and the end cover is closed by magnetic force. The movable catheter and the spiral sheet are both made of flexible ferrite 444 stainless steel, which is magnetic and can be magnetized. After magnetization, the magnetism of the drill bit structure and the magnetism of the cover body and the guide wire are repelled by the magnetic pole of the guide wire, and the repulsive force is greater than the attraction of the guide wire to the cover body. Therefore, when the drill bit structure is pushed out along the guide wire, the cover body opens due to the magnetic repulsion. When used in a blood vessel, the distal end of the drill bit structure will protrude from the guide wire because the guide wire cannot enter the blocked area. At this time, it does not affect the opening or closing of the end cover.

[0026] Furthermore, the balloon dilatation catheter also includes a catheter seat arranged at the distal end of the outer tube and the distal end of the inner tube, and the catheter seat is provided with a first channel for the movable catheter to pass through and a second channel for liquid and / or gas to pass through. The first channel is connected to the inner tube, and the extension direction of the first channel is consistent with the extension direction of the inner tube. The second channel is connected to the proximal end of the annular channel.

[0027] Furthermore, the catheter seat is provided with a driving device capable of driving the movable catheter to move axially and / or rotate around its own axis.

[0028] According to some specific embodiments, the axial length of the drill bit structure is 2-3 mm.

[0029] According to some specific embodiments, the axial lengths of the outer balloon and the inner balloon are independently 5 to 10 mm.

[0030] According to some specific embodiments, the maximum inner diameter of the inner balloon is 2-3 mm.

[0031] According to some specific embodiments, the maximum outer diameter of the outer balloon when inflated is 3-5 mm.

[0032] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0033] The balloon dilatation catheter of the present invention has a double-balloon structure and a drill structure is provided in the inner balloon. The distal end of the inner balloon can be opened, and the drill structure can be extended from the distal end of the inner balloon to perform deep drilling on the thrombus tissue, thereby improving the effect of dredging and dilating blood vessels. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] It should be noted that in order to fully display the structure in the drawings, the proportional relationship in the drawings has been adaptively adjusted, but it does not represent the proportional relationship of the structures of the various parts in actual use, or the proportional relationship in the drawings as a factor in limiting the scope of protection of the present invention.

[0036] Figure 1 Schematic diagram of the three-dimensional structure of the balloon dilatation catheter of Example 1;

[0037] Figure 2 This is a front view of the balloon dilatation catheter of Example 1;

[0038] Figure 3 is a cross-sectional view of the balloon dilatation catheter of Example 1;

[0039] Figure 4 is a front view of the balloon dilatation catheter of Example 1 in another state;

[0040] Figure 5This is a schematic structural diagram of some components of the balloon dilatation catheter of Example 1.

[0041] In the above figure: 11, inner tube; 12, outer tube; 13, outer balloon; 14, inner balloon; 15, filling chamber; 16, end cap; 161, annular seat; 162, cover body; 1621, silicone head; 21, movable catheter; 22, spiral sheet; 3, guide wire; 4, catheter seat. DETAILED DESCRIPTION

[0042] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0043] In the description of the present invention, it should be understood that the distal end refers to the end of the instrument or component away from the operator, and the proximal end refers to the end of the instrument or component close to the operator; the axial direction refers to the direction parallel to the line connecting the distal and proximal centers of the instrument or component, and the radial direction refers to the direction perpendicular to the axial direction; the inner and outer are positions defined by the distance relative to the center of the instrument or component, where the inner position is close to the center of the instrument or component, and the outer position is far from the center of the instrument or component. The description of the above-mentioned directional words is only for the convenience of describing the embodiments of the present invention and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention.

[0044] In the description of the present invention, unless otherwise specified or limited, the terms "connected" and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0045] In the description of the present invention, a plurality refers to two or more.

[0046] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example 1

[0047] This embodiment is an implementation of the balloon dilatation catheter of the present invention. Figures 1 to 5 As shown, it includes a double-layer balloon assembly, a drill assembly, a catheter seat 4 and a guide wire 3.

[0048] Specifically, the double-layer balloon assembly includes an inner tube 11, an outer tube 12 sleeved outside the inner tube 11, an outer balloon 13 arranged at the distal end of the outer tube 12, and an inner balloon 14 arranged at the distal end of the inner tube 11. The inner balloon 14 is located in the outer balloon 13, and a filling cavity 15 is formed between the outer wall of the inner balloon 14 and the inner wall of the outer balloon 13. An annular channel connected to the filling cavity 15 is formed between the outer wall of the inner tube 11 and the inner wall of the outer tube 12 for transporting liquid and / or gas (such as a mixed solution of injection water and developer) into the filling cavity 15. The distal ends of the inner balloon 14 and the outer balloon 13 are provided with end covers 16 that can be opened and closed, and the distal ends of the outer balloon 13 and the distal ends of the inner balloon 14 are closed and connected. In this embodiment, the end cap 16 includes an annular seat 161 and a conical cap disposed on the annular seat 161. The distal ends of the outer balloon 13 and the inner balloon 14 are fixedly connected to the annular seat 161, respectively. The conical cap is composed of a plurality of magnetic cover bodies 162 connected by magnetic attraction. The cover body 162 is integrally formed with the annular seat 161 and the cover body 162 is reversible. The cover body 162 is provided with a magnetic sheet. The outer diameter of the conical cap gradually decreases from the annular seat 161 toward the direction away from the inner balloon 14. In this embodiment, the structures of the inner balloon 14 and the outer balloon 13 are roughly the same. From the proximal end to the distal end, the inner diameter first gradually increases and then remains unchanged, similar to a horizontal U-shaped structure. The outer edge of the annular seat 161 is fixedly connected to the distal end of the outer balloon 13, and the inner edge of the annular seat 161 is fixedly connected to the distal end of the inner balloon 14, thereby sealing the distal end of the outer balloon 13 and the distal end of the inner balloon 14. The axes of the inner balloon 14, outer balloon 13, outer tube 12, inner tube 11, movable catheter 21 and end cap 16 coincide. In this embodiment, there are four caps 162, and the distal end of each cap 162 is a silicone head 1621 with a magnetic sheet.

[0049] Specifically, the drill assembly includes a movable catheter 21 and a drill structure disposed at the distal end of the movable catheter 21. The movable catheter 21 is movably inserted into the inner tube 11. The drill structure comprises a spiral blade 22 wound around the outer periphery of the distal end of the movable catheter 21 and extending axially along the movable catheter 21. The outer diameter of the spiral blade 22 gradually increases from the distal end of the movable catheter 21 to the proximal end. The axial length of the spiral blade 22 is two-thirds the axial length of the inner balloon 14. The spiral blade 22 and the distal end of the movable catheter 21 have magnetic properties that repel the magnetic properties of the cover 162. In this embodiment, the movable catheter 21 is provided with a guidewire passage extending from the proximal end to the distal end and open at both ends for the passage of the guidewire 3. The guidewire 3 has magnetic properties that attract the magnetic properties of the cover 162. After the guidewire 3 is inserted, the conical cap is closed and adheres to the guidewire 3 by magnetic force, further improving the stability of the closure. In this embodiment, the guide wire 3 is made of flexible ferrite 444 stainless steel instead of conventional 304 stainless steel, allowing it to be attracted by the magnetic sheet on the cover 162, achieving a closed state of the end cap 16 through magnetic force. The movable guide tube 21 and spiral sheet 22 are both made of flexible ferrite 444 stainless steel, which is magnetic and can be magnetized. After magnetization, the magnetic properties of the drill bit structure repel the magnetic properties of the cover 162 and the guide wire 3 due to the magnetic poles of the guide wire 3. The repulsive force is greater than the attractive force of the guide wire 3 on the cover 162. Therefore, when the drill bit structure is pushed along the guide wire 3, the cover 162 opens due to the magnetic repulsion.

[0050] Specifically, catheter adapter 4 is disposed at the distal ends of outer tube 12 and inner tube 11. It defines a first passageway for the passage of movable catheter 21 and a second passageway for the passage of liquid and / or gas. The first passageway communicates with inner tube 11, extending in the same direction as inner tube 11. The second passageway communicates with the proximal end of the annular passageway. In this embodiment, catheter adapter 4 is provided with a drive device capable of driving the movable assembly to move axially and rotate about its own axis.

[0051] In this embodiment, the axial length of the drill bit structure is 2.5 mm, the axial length of the outer balloon 13 is 10 mm, the axial length of the inner balloon 14 is 8 mm, the maximum inner diameter of the inner balloon 14 is 2.5 mm, and the maximum outer diameter of the outer balloon 13 when filled is 4 mm.

[0052] The balloon dilatation catheter of this embodiment has a first working state and a second working state. When the balloon dilatation catheter is in the first working state, the drill structure is located in the inner balloon 14, and the end cap 16 is closed. When the balloon dilatation catheter is in the second working state, at least part of the drill structure is located outside the distal end of the inner balloon 14, and the end cap 16 is open. The balloon dilatation catheter can be switched between the first working state and the second working state by operating the movable catheter 21. The end cap 16 at the distal end of the double-balloon structure of this embodiment has a flap design. The conical end cap 16 is divided into four flaps. When the micro-drill structure is extended by a thrust, the end cap 16 is pushed open. The end cap 16 remains open until the drill is fully retracted and then closes again. The micro-drill structure in the balloon dilatation catheter of this embodiment can extend from the distal end of the inner balloon 14 to drill deep into thrombus tissue, improving the effect of dredging and dilating blood vessels.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A balloon dilatation catheter, characterized in that: The balloon dilatation catheter comprises: A double-layer balloon assembly, comprising an inner tube (11), an outer tube (12) sleeved outside the inner tube (11), an outer balloon (13) arranged at the distal end of the outer tube (12), and an inner balloon (14) arranged at the distal end of the inner tube (11), wherein the inner balloon (14) is located in the outer balloon (13), a filling cavity (15) is formed between the outer side wall of the inner balloon (14) and the inner side wall of the outer balloon (13), an annular channel connected to the filling cavity (15) and used for conveying liquid and / or gas into the filling cavity (15) is formed between the outer side wall of the inner tube (11) and the inner side wall of the outer tube (12), the distal end of the inner balloon (14) and the distal end of the outer balloon (13) are provided with an end cap (16) that can be opened and closed, and the distal end of the outer balloon (13) and the distal end of the inner balloon (14) are sealed and connected; A drill bit assembly comprises a movable guide tube (21) and a drill bit structure arranged at the distal end of the movable guide tube (21), wherein the movable guide tube (21) is movably inserted into the inner tube (11). The balloon dilatation catheter has a first working state and a second working state. When the balloon dilatation catheter is in the first working state, the drill bit structure is located in the inner balloon (14) and the end cap (16) is closed; When the balloon dilatation catheter is in the second working state, at least part of the drill structure is located outside the distal end of the inner balloon (14), and the end cap (16) is opened; The balloon dilatation catheter is switched between the first working state and the second working state by operating the movable catheter (21).

2. The balloon dilatation catheter according to claim 1, characterized in that: The end cover (16) includes an annular seat (161) and a conical cap arranged on the annular seat (161). The distal ends of the outer balloon (13) and the inner balloon (14) are fixedly connected to the annular seat (161) respectively. The conical cap is composed of a plurality of magnetic cover bodies (162) connected by magnetic attraction. The cover body (162) and the annular seat (161) are integrally formed and the cover body (162) is flippable. The cover body (162) is provided with a magnetic sheet. The outer diameter of the conical cap gradually decreases from the annular seat (161) in a direction away from the inner balloon (14).

3. The balloon dilatation catheter according to claim 2, characterized in that: The number of the cover bodies (162) is 3 to 5, and the distal end of the cover body (162) is a silicone head (1621) provided with a magnetic sheet.

4. The balloon dilatation catheter according to claim 2, characterized in that: The drill bit structure has magnetic properties that repel the magnetic properties of the cover body (162).

5. The balloon dilatation catheter according to claim 2, characterized in that: The drill bit structure is a spiral sheet (22) wound around the outer periphery of the distal end of the movable catheter (21) and extending along the axial direction of the movable catheter (21), and the outer diameter of the spiral sheet (22) gradually increases from the distal end to the proximal end of the movable catheter (21).

6. The balloon dilatation catheter according to claim 5, characterized in that: The axial length of the spiral sheet (22) is 1 / 3 to 2 / 3 of the axial length of the inner balloon (14).

7. The balloon dilatation catheter according to claim 2, characterized in that: The movable catheter (21) is provided with a guide wire channel extending from the proximal end to the distal end thereof and open at both ends for the guide wire (3) to pass through. The balloon dilatation catheter further comprises a guide wire (3), and the guide wire (3) has magnetic properties that are attracted to the magnetic properties of the cover body (162).

8. The balloon dilatation catheter according to claim 1, characterized in that: The balloon dilatation catheter further comprises a catheter seat (4) arranged at the distal end of the outer tube (12) and the distal end of the inner tube (11), the catheter seat (4) being provided with a first channel for the movable catheter (21) to pass through, and a second channel for liquid and / or gas to pass through, the first channel being connected to the inner tube (11), the extension direction of the first channel being consistent with the extension direction of the inner tube (11), and the second channel being connected to the proximal end of the annular channel.

9. The balloon dilatation catheter according to claim 8, characterized in that: The catheter seat (4) is provided with a driving device capable of driving the movable catheter (21) to move axially and / or rotate around its own axis.

10. The balloon dilatation catheter according to claim 1, characterized in that: The axial length of the drill structure is 2 to 3 mm; and / or the axial lengths of the outer balloon (13) and the inner balloon (14) are independently 5 to 10 mm.

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