A multi-directionally adjustable curved microcatheter and method of manufacturing the same

Abstract

The application discloses a multi-direction adjustable bending microcatheter, which comprises a main catheter and a traction assembly; the main catheter has an adjustable bending section and a supporting section; the adjustable bending section is provided with a first skeleton assembly; the first skeleton assembly comprises a plurality of first skeleton units which are connected in sequence; each first skeleton unit comprises two supporting members and a plurality of limiting beads; the limiting beads are arranged in a staggered symmetrical distribution mode on the supporting members; four first channels are uniformly distributed in the supporting section and can be passed through by the traction assembly; the traction assembly comprises four traction wires and a fixing ring; the traction wires are fixed to the end of the adjustable bending section through the fixing ring; the other ends pass through the first skeleton assembly and the supporting section and are led out from the end of the supporting section. The application further discloses a manufacturing method for manufacturing the multi-direction adjustable bending microcatheter. The application can accurately control the curvature of the distal end head in multiple directions, improve the flexibility of the doctor in operating the catheter and the operation efficiency, and reduce the risk.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a multidirectional adjustable bendable microcatheter and its manufacturing method. Background Technology

[0002] Since the advent of hand-to-brain angiography in 1927, the treatment of various head and neck diseases has been revolutionized by the intervention of endovascular surgery, including the treatment of aneurysms, arteriosclerosis, and stroke. Catheters are introduced into the vascular system through small incisions in the skin, reaching pathological areas of the neurovascular system. Other medical devices or therapeutic drugs are then delivered through the catheter's lumen for targeted treatment. These minimally invasive procedures allow patients to benefit from faster, more effective recovery times and less discomfort.

[0003] However, for interventional physicians, the following problems with current microcatheter products used in interventional procedures urgently need to be addressed:

[0004] (1) The degree of freedom and feedback of catheter insertion instruments are limited. When the traditional catheter used for neurovascular surgery is in the patient’s body, the control of the tip of the interventional instrument is limited. When guided in the vascular system, the tip of the traditional catheter is generally fixed and has an unchangeable curvature, making it difficult to select branches in vascular networks with different curvatures. At this time, it is necessary to remove or replace the catheter, which increases the operation time and the difficulty of the doctor’s operation.

[0005] (2) For the treatment of intracranial aneurysms, the tip of the interventional device (usually a microcatheter) needs to be pre-shaped to reach the target position and deliver the coil into the aneurysm. However, the pre-shaping of the microcatheter increases the interventional procedure time and the difficulty of the doctor's operation. Sometimes, it may be necessary to perform multiple shaping operations to reach the target position. The control of these catheters is highly dependent on the interventional physician's operating skills and requires a very high level of operation.

[0006] (3) Traditional interventional surgery first uses a microguidewire to create a path, and then inserts a 4F~8F catheter along the microguidewire path. However, the disadvantage is that the tip of the microguidewire is thin, which may puncture the thin blood vessel wall and cause bleeding risk. Moreover, the microguidewire catheter approach is prone to the "windowsill effect", which makes it difficult to deliver instruments well.

[0007] (4) The effect of catheter products currently used in the market when they enter the patient’s body through the digital subtraction angiography (DSA) system is often difficult to distinguish. It is very difficult for doctors to view the patient’s image from a distance, which can easily lead to difficulty in distinguishing the image and the need for multiple angiography. Summary of the Invention

[0008] To overcome the shortcomings of existing technologies, this invention provides a multi-directional adjustable bendable microcatheter and its manufacturing method, which can accurately control the curvature of the distal tip in multiple directions, improve the flexibility of doctors in operating the catheter and the efficiency of surgery, and reduce risks.

[0009] The first aspect of the present invention is to provide a multidirectional adjustable bendable microcatheter, including a main guide tube and a traction component;

[0010] The main pipe has an adjustable bending section and a support section;

[0011] The adjustable bending section is provided with a first skeleton assembly, which includes several first skeleton units connected in sequence. Each first skeleton unit includes two support members and several limiting beads. The limiting beads have through holes. The support members are annular structures, and the support members have first, second, third, and fourth through holes evenly distributed around their circumference. The first and third through holes are opposite to each other, and the second and fourth through holes are opposite to each other. The two support members are coaxially arranged, forming an adjustment gap between them. A first number of limiting beads are provided between two corresponding first through holes in the adjustment gap, and a first number of limiting beads are provided between two corresponding third through holes in the adjustment gap. The second and fourth through holes on the side of one support member away from the adjustment gap are each provided with a first number of limiting beads. The support section has four first channels evenly distributed for the traction assembly to pass through.

[0012] The traction assembly includes four traction wires and a fixing ring. The ends of the four traction wires are all fixed to the end of the adjustable bending section by the fixing ring. The other ends of the four traction wires pass through the first skeleton assembly and the support section respectively, corresponding to the first through hole, the second through hole, the third through hole and the fourth through hole, and emerge from the end of the support section.

[0013] In a first aspect of the invention, as a preferred embodiment, the surface of the traction wire is covered with a covering tube, the covering tube including a proximal covering tube and a distal covering tube connected to each other, the proximal covering tube being disposed within the support section, and the distal covering tube being disposed within the adjustable bending section.

[0014] In a first aspect of the present invention, as a preferred embodiment, a second skeleton assembly is provided within the support segment. The second skeleton assembly includes a plurality of second skeleton units connected in sequence. Each second skeleton unit includes a support member and a plurality of limiting beads. A second number of limiting beads are provided on the first through hole, the second through hole, the third through hole, and the fourth through hole of the support member, thereby forming four first channels with the through holes of the limiting beads respectively.

[0015] In a first aspect of the present invention, as a preferred embodiment, the support segment further includes a first spring layer and a second spring layer; the first spring layer is made of flat wire and round wire; the second spring layer is made of 8 to 32 strands of springs.

[0016] In a first aspect of the present invention, as a preferred embodiment, the support segment further includes a first spring layer and a second braided layer; the first spring layer is made of flat wire and round wire; the second braided layer is made of 8 to 32 spindles of multi-strand braided wire.

[0017] In a first aspect of the present invention, as a preferred embodiment, the main tube further includes an inner tube layer and an outer tube layer, and the adjustable bend section and the support section are disposed between the inner tube layer and the outer tube layer;

[0018] The inner tube layer is made of a polymer material with high lubricity and ductility; the outer tube layer sleeved on the outer periphery of the adjustable bending section is made of a flexible polymer composite material; and the outer tube layer sleeved on the outer periphery of the support section is made of a polymer composite material with higher hardness.

[0019] The fixing ring and the support are made of a metallic material with non-transmittent linearity.

[0020] In a first aspect of the invention, as a preferred embodiment, a handle is further included, the handle being connected to the end of the support segment; the handle includes a bending adjustment structure connected to the traction assembly for controlling the curvature of the adjustable bending segment by pulling the traction wire.

[0021] A second aspect of the present invention provides a method for manufacturing a multidirectional adjustable bendable microcatheter, comprising the following steps:

[0022] Fabrication of a traction assembly: A distal end covering tube, a proximal end covering tube, and traction wires are provided. The ends of the distal end covering tube and the proximal end covering tube are connected. The traction wires are threaded through the distal end covering tube and the proximal end covering tube, resulting in four traction wires with covering tubes on their surfaces. A fixing ring is provided, and the ends of the four traction wires that extend from the proximal end covering tube are evenly distributed and fixed around the fixing ring, thus obtaining the traction assembly.

[0023] Fabrication of an adjustable bending section: Several metal rings are provided, with first, second, third, and fourth through holes evenly distributed around their circumference. The first and third through holes are positioned opposite each other, as are the second and fourth through holes, forming a support member. Several limiting beads with internal through holes are provided. Two support members are coaxially arranged, forming an adjustment gap between them. A first number of limiting beads are placed between corresponding first through holes and between corresponding third through holes in the adjustment gap. A first number of limiting beads are placed on the second and fourth through holes on the side of one support member away from the adjustment gap, respectively, forming a first skeleton unit. Several first skeleton units are sequentially fitted onto the traction assembly using four traction wires with covered tubes on their surfaces, corresponding to the first, second, third, and fourth through holes, respectively, to form an adjustable bending section. At this point, the remaining part of the traction assembly protrudes from the adjustable bending section.

[0024] Manufacturing the support section: Place four sets of the second number of limiting beads on the first through hole, second through hole, third through hole and fourth through hole of the support member to form a second skeleton unit; insert several second skeleton units into the traction assembly that passes through the adjustable bending section to obtain the first semi-finished tube.

[0025] Fabrication of inner and outer tubes: An inner tube is provided, which is a thin tube made of a polymer material with high lubricity and ductility; the inner tube is inserted into a first semi-finished product to obtain a second semi-finished product tube; a distal outer tube material is provided, which is composed of a flexible polymer composite material; the distal outer tube material is rheoformed onto the adjustable bending section of the second semi-finished product tube; a proximal outer tube material is provided, which is composed of a polymer composite material with high hardness; the proximal outer tube material is rheoformed onto the surface of the support section of the second semi-finished product tube; a main tube is obtained.

[0026] Install the handle: Install the end of the main tube away from the adjustable bend section to the handle connection port, and connect the traction component to the bend adjustment structure of the handle.

[0027] In a second aspect of the present invention, as a preferred embodiment, the step of manufacturing the support segment further includes the following steps:

[0028] A number of round wires and a number of flat wires are provided, and the round wires and the flat wires are wound side by side around the support section to obtain a first spring layer; 8 to 32 spindles of multi-strand metal wires are provided, and the multi-strand metal wires are wound onto the surface of the first spring layer through a spring winding device to form a second spring layer.

[0029] In a second aspect of the present invention, as a preferred embodiment, the step of manufacturing the support segment further includes the following steps:

[0030] A number of round wires and a number of flat wires are provided, and the round wires and the flat wires are wound side by side around the support section to obtain a first spring layer; 8 to 32 spindles of multi-strand metal wires are provided, and the multi-strand metal wires are woven into the first spring layer by a braiding device to form a second braided layer.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention provides a multi-directional adjustable bend microcatheter that can accurately control the curvature of the distal tip in multiple directions, effectively improving the flexibility of the doctor in operating the catheter. The angle of the adjustable bend at the distal end can be controlled by the handle acting on the traction component to make vascular access. When encountering vascular crossing or tortuous locations, the curvature of the adjustable bend can be adjusted to achieve the optimal state and complete the entire surgical procedure.

[0033] 2. Particularly in the treatment of intracranial aneurysms, the multidirectional adjustable bendable microcatheter of this invention is suitable for filling aneurysm coils. When the distal tip of the catheter reaches the aneurysm, the release angle can be adjusted left-right or forward-backward using the operating handle while releasing the coil, ensuring that the filled coil covers the entire aneurysm as much as possible, preventing the risk of coil dislodgement due to insufficient filling. With the fixing ring and support at the end of the adjustable bend, the multidirectional adjustable bendable microcatheter of this invention is more visible than similar products under the support of a digital subtraction angiography (DSA) system, making it easier for doctors to observe the swinging state of the tip during surgery and adjust the angle in a timely manner.

[0034] 3. Traditionally, during surgery, the microguidewire tip is manually shaped before being inserted into the blood vessel. The guidewire is then rotated using a knob to create the path. This method is time-consuming, the knob rotation process cannot achieve a precise angle, resulting in a "bouncing" phenomenon, and the microguidewire's small outer diameter makes it difficult to determine its position using digital subtraction angiography (DSA). Furthermore, the microguidewire tip may puncture thin vessel walls, leading to vascular rupture and defects. However, the multi-directional adjustable bendable microcatheter of this invention eliminates the need for a guidewire. Simply adjusting the handle to control the bend angle of the tip allows entry into multi-branched or tortuous vessels. The bend adjustment is highly stable, preventing displacement during the insertion process. The outer diameter range of this invention is 2-3 times larger than that of the microguidewire. When used with other catheter products, the smaller gap reduces the likelihood of the "windowsill effect," improving intraoperative efficiency and effectively reducing risks and controlling costs. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the multidirectional adjustable bendable microcatheter of the present invention;

[0036] Figure 2This is a schematic diagram of the internal structure of the multidirectional adjustable bendable microcatheter of the present invention;

[0037] Figure 3 This is a schematic diagram of the internal structure of a multidirectional adjustable bendable microcatheter according to another embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the first skeleton unit of the multidirectional adjustable bendable microcatheter of the present invention;

[0039] Figure 5 This is a schematic diagram of the connection structure between the first skeleton unit and the traction component of the multidirectional adjustable bend microcatheter of the present invention.

[0040] Figure 6 This is a schematic diagram of the structure of the second skeleton unit of the multidirectional adjustable bendable microcatheter of the present invention;

[0041] Figure 7 This is a cross-sectional view of the adjustable bend section of the multidirectional adjustable bend microcatheter of the present invention.

[0042] Figure 8 This is a cross-sectional view of the support section of the multidirectional adjustable bendable microcatheter of the present invention;

[0043] Figure 9 This is a cross-sectional view of the support section of another embodiment of the multidirectional adjustable bendable microcatheter of the present invention.

[0044] Figure 10 This is a schematic diagram showing the usage state of the multi-directional adjustable bendable microcatheter of the present invention;

[0045] Figure 11 This is a schematic diagram of another usage state of the multidirectional adjustable bendable microcatheter of the present invention.

[0046] In the diagram: 100, main tube; 110, adjustable bend; 111, first skeleton unit; 1111, support member; 1111a, first through hole; 1111b, second through hole; 1111c, third through hole; 1111d, fourth through hole; 1112, limiting bead; 120, support section; 121, second skeleton unit; 122, first coiled spring layer; 123, second coiled spring layer; 124, second braided layer; 130, inner tube layer; 140, outer tube layer; 200, traction assembly; 210, fixing ring; 220, traction wire; 221, proximal covering tube; 222, distal covering tube; 300, handle. Detailed Implementation

[0047] The invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0048] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.

[0051] Example 1

[0052] like Figure 1-11 As shown, this embodiment provides a multidirectional adjustable bendable microcatheter, including a main tube 100, a traction component 200, and a handle 300.

[0053] The main tube 100 has an adjustable bend 110 and a support section 120. In this embodiment, the overall outer diameter of the main tube 100 is between 1.6F and 3F (0.528mm to 0.99mm), the adjustable bend 110 is designed to be between 2mm and 60mm in length, and the overall effective length ranges from 100cm to 200cm.

[0054] Specifically, the adjustable bending section 110 is provided with a first skeleton assembly, which is formed by sequentially connecting a plurality of first skeleton units 111. In this embodiment, the first skeleton unit 111 includes two support members 1111 and a plurality of limiting beads 1112. The limiting beads 1112 are small spherical shapes with through holes inside. The support members 1111 are annular structures. The main function of the support members 1111 is to support the adjustable bending section 110 to prevent deformation during bending and to maintain the integrity of the inner cavity. Its material is metal (such as platinum-iridium, stainless steel, nickel-titanium, tungsten, copper, etc.), which has non-transmittance linearity and can be used as a good developing material. The support members 1111 are evenly distributed with first through holes 1111a and second through holes 111 in the circumferential direction. 1b. A third through hole 1111c and a fourth through hole 1111d, wherein the first through hole 1111a and the third through hole 1111c are arranged opposite each other, and the second through hole 1111b and the fourth through hole 1111d are arranged opposite each other; two support members 1111 are coaxially arranged, forming a bending gap between the two support members 1111; a first number of limiting beads 1112 are provided between the two corresponding first through holes 1111a in the bending gap, and a first number of limiting beads 1112 are provided between the two corresponding third through holes 1111c in the bending gap; at the same time, a first number of limiting beads 1112 are respectively provided on the second through hole 1111b and the fourth through hole 1111d on the side of one of the support members 1111 away from the bending gap;

[0055] The support section 120 has four first channels evenly distributed within it, allowing the traction assembly 200 to pass through. The support section 120 mainly provides stronger support for the distal end, enabling the distal end of the conduit to reach a more distant position. The support section 120 has high tube hardness and strong torsional response capability.

[0056] The traction assembly 200 includes four traction wires 220 and a fixing ring 210; the ends of the four traction wires 220 are all fixed to the end of the adjustable bend 110, i.e. the far end of the main tube 100, by the fixing ring 210.

[0057] The traction wire 220 is made by twisting, which generally requires 3 to 10 wires to be wound together at the same time using equipment to form a twisted structure, thus giving it superior flexural strength and tensile strength compared to round wires of the same outer diameter.

[0058] The retaining ring 210 is mainly used to fix the traction wire 220. On the other hand, the retaining ring 210 is made of a metal material with non-transmittent linearity and is used for positioning and imaging effect of the head end of the adjustable bend 110.

[0059] The free ends of the four traction wires 220 of the traction assembly 200 pass through the first skeleton assembly and the support section 120 respectively, corresponding to the first through hole 1111a, the second through hole 1111b, the third through hole 1111c and the fourth through hole 1111d, and exit from the end of the support section 120 to connect with the handle 300.

[0060] The handle 300 is connected to the end of the support section 120; the handle 300 includes a bending adjustment structure, which is connected to the traction assembly 200, and is used to control the curvature of the adjustable bending section 110 by pulling the traction wire 220. In this embodiment, the handle 300 can be implemented using an existing operating handle with traction wire control function; its specific structure is well known to those skilled in the art and will not be described in detail here.

[0061] In this embodiment, the limiting bead 1112 serves to limit the bending angle. The larger the adjustment angle, the more limiting beads 1112 are needed, resulting in a larger bending gap. In this embodiment, the limiting beads 1112 are arranged in a staggered, symmetrical pattern within the bending gap of each unit. This arrangement allows the bending segment 110 to be bent in four evenly distributed directions (i.e., the direction from the axis of the bending segment 110 towards the first through hole 1111a, the second through hole 1111b, the third through hole 1111c, and the fourth through hole 1111d). Bending can also be achieved by pulling adjacent traction wires 22. 0. Adjust the direction of the middle section of each adjacent traction wire 220. For example, by pulling the traction wire 220 in the first through hole 1111a and the second through hole 1111b, the adjustable bending section 110 bends to a point between the first through hole 1111a and the second through hole 1111b, thus realizing the all-round bending of the microcatheter. On the other hand, when the adjustable bending section 110 is bent by traction, the contact point between the two adjacent limiting beads 1112 on the squeezed side changes along its spherical surface, the connection stability between them is stronger, and the curvature change process is smoother, without jamming, folding or other situations, thus achieving more precise control.

[0062] In order to improve the smoothness of the traction wire 220 during stretching and to prevent the traction wire 220 from deforming due to the influence of adjacent layer structures, the traction wire 220 in this embodiment is covered with a covering tube, which includes a proximal covering tube 221 and a distal covering tube 222 that are connected to each other.

[0063] The proximal end capping tube 221 is fitted onto the surface of the traction wire 220 within the support section 120. The proximal end capping tube 221 is made of a relatively rigid polymer material, which not only enhances the strength of the support section 120 but also effectively protects the traction wire 220 during its movement within the lumen. The inner diameter of the proximal end capping tube 221 is more than half the outer diameter of the traction wire 220 to prevent deformation of the proximal end capping tube 221 after catheter formation, which could affect the tension of the traction wire 220.

[0064] The distal end covering tube 222 is fitted onto the surface of the traction wire 220 within the adjustable bend 110. The distal end covering tube 222 is made of a relatively soft polymer tubing, which can enhance its flexibility and tensile strength, ensuring that the adjustable bend 110 can be bent and shaped.

[0065] As one embodiment of the support section 120, a second skeleton assembly is provided within the support section 120. The second skeleton assembly is composed of multiple second skeleton units 121 connected in sequence. Each second skeleton unit 121 includes a support member 1111 and a plurality of limiting beads 1112. A second number of limiting beads 1112 are provided on the first through hole 1111a, the second through hole 1111b, the third through hole 1111c, and the fourth through hole 1111d of the support member 1111, thereby forming four first channels with the through holes of the limiting beads 1112. That is, the limiting beads 1112 are arranged in an equal number in a ring on the support member 1111. This arrangement can enhance the rigidity of the support section 120, reduce the bending radius, and provide stronger support and torsional control for the adjustable bending section 110.

[0066] The hardness of the proximal tube body can be adjusted by changing the number of limiting beads 1112 in each second skeleton unit 121 of the second skeleton assembly. Fewer limiting beads 1112 result in more support members 1111, meaning a higher density of support members 1111, better support of the support segment 120, and better force transmission. Based on the hardness adjustment effect of the limiting beads 1112 on the support segment 120, and combined with the hardness requirements of different sections of the support segment 120, the limiting beads 1112 in the second skeleton unit 121 formed by different sections of the support segment 120 can be increased or decreased sequentially to control the hardness gradually. Furthermore, the preset curvature of the support segment 120 can be adjusted by setting different numbers of limiting beads 1112 on the first through hole 1111a, second through hole 1111b, third through hole 1111c, and fourth through hole 1111d of the second skeleton unit 121.

[0067] In another embodiment of the support section 120, the support section 120 includes a first spring layer 122 and a second spring layer 123; the first spring layer 122 is made of flat wire and round wire wound together; the second spring layer 123 is made of multi-strand springs wound with 8 to 32 spindles. The combination of the two spring layers with different structures forms a reinforcing layer, which improves the torsional resistance of the support section 120.

[0068] In another embodiment of the support section 120, the support section 120 further includes a first spring layer 122 and a second braided layer 124; the first spring layer 122 is made of flat and round wires wound together; the difference is that the second braided layer 124 is made of 8 to 32 spindles of multi-strand braided filaments. The reinforcing layer formed by the combination of the spring layer and the mesh braided layer improves the bending resistance of the support section 120.

[0069] The above support section 120 can also be implemented by using a second skeleton component, two different structures of spring layers, or a combination of spring layers and mesh braided layers. Adaptive adjustments can be made according to the actual situation, which can be understood by those skilled in the art.

[0070] In this embodiment, the main tube 100 further includes an inner tube layer 130 and an outer tube layer 140, with the adjustable bend 110 and support section 120 disposed between the inner tube layer 130 and the outer tube layer 140. The inner tube layer 130 is made of PTFE, which has good lubricity and ductility, and can be processed into a thin tube, contributing to the flexibility of the adjustable bend 110 and adapting to the delivery device requirements within the main tube 100 cavity. The outer tube layer 140 includes a distal outer tube layer and a proximal outer tube layer. The distal outer tube layer is a segment of the outer tube layer 140 sleeved around the adjustable bend 110, made of a flexible polymer composite material, using PU, TPU, and PEBAX polymer composite tubing, heated in a rheometer until fused with the inner structure, exhibiting characteristics such as flexibility, easy bending, and strong resilience. The proximal outer tube layer is an outer tube layer 140 segment sleeved around the support section 120, made of high-hardness polymer composite material; it is made of nylon and PEBAX polymer composite material, which is heated by a rheometer to fuse with the inner layer structure, and its characteristics include high hardness and strong resistance to deformation.

[0071] Example 2

[0072] This embodiment provides a method for manufacturing a multidirectional adjustable bendable microcatheter, used to produce the multidirectional adjustable bendable microcatheter of Embodiment 1, comprising the following steps:

[0073] Step S1: Fabricate traction component 200;

[0074] A distal end covering tube 222, a proximal end covering tube 221, and a traction wire 220 are provided. The distal end covering tube 222 and the proximal end covering tube 221 are connected at their ends, and the traction wire 220 is passed through the distal end covering tube 222 and the proximal end covering tube 221. This results in four traction wires 220 with covering tubes on their surfaces. Specifically, the connection between the distal end covering tube 222 and the proximal end covering tube 221 can be achieved by cutting the distal end covering tube 222 to a designed length of 10mm to 50mm, making a flared shape at one end, and then passing the traction wire 220 through the flared shape to the other end (leaving enough traction wire 220 at the other end for the proximal end covering tube 221 to pass through). Take out the proximal end covering tube 221 and cut it again according to the design dimensions of 100cm to 200cm for the total length of the support section 120. At this time, both ends of the cut are flat. You can cut one end at an angle of 45 to 70 degrees to form an elliptical cross section. Then insert the traction wire 220 into the hole of the elliptical cross section and connect it with the flared mouth of the distal end covering tube 222. Use laser welding or UV curing bonding to firmly fix the interface.

[0075] A fixing ring 210 is provided, and the four traction wires 220, extending from the proximal end of the covering tube 221, are evenly fixed to the circumference of the fixing ring 210 to obtain the traction assembly 200. Specifically, four traction wire welding holes are made at 90° intervals in the circumference at the thick end of the fixing ring 210 using laser cutting and laser drilling. The ends of the traction wires 220 extending from the proximal end of the covering tube 221 are inserted into the traction wire welding holes in the developing ring, and then filled and fused using welding material. After filling the four traction wire welding holes in the developing ring in this way, the welding strength is tested using a tensile testing instrument and found to be above 5N, thus completing the fabrication of the traction assembly 200.

[0076] Step S2: Create the adjustable bend 110;

[0077] A plurality of metal rings are provided, which can be manufactured from tubes containing developing material or metal material according to designed inner diameter, outer diameter, thickness, and width dimensions. A first through hole 1111a, a second through hole 1111b, a third through hole 1111c, and a fourth through hole 1111d are laser-drilled at 90° intervals along the circumference of the metal rings, wherein the first through hole 1111a and the third through hole 1111c are arranged opposite each other, and the second through hole 1111b and the fourth through hole 1111d are arranged opposite each other, thus obtaining a support member 1111. A plurality of limiting beads 1112 are provided, which are made by laser-drilling through the center of a sphere of a designed size. Two support members 1111 are coaxially arranged, forming a bending gap between the two support members 1111. A first number of limiting beads 1112 are placed between corresponding two first through holes 1111a in the bending gap, and a first number of limiting beads 1112 are placed between corresponding two third through holes 1111c in the bending gap. A first number of limiting beads 1112 are placed; the first number of limiting beads 1112 are placed on the second through hole 1111b and the fourth through hole 1111d on the side of the support member 1111 away from the bending gap, respectively, to obtain the first skeleton unit 111; through four traction wires 220 with covering tubes on their surfaces, corresponding to the first through hole 1111a, the second through hole 1111b, the third through hole 1111c and the fourth through hole 1111d respectively, several first skeleton units 111 are sequentially sleeved onto the traction assembly 200 to obtain the adjustable bending section 110. At this time, the remaining part of the traction assembly 200 passes through the adjustable bending section 110. It should be noted that the insertion method is symmetrical, and the number of symmetrical limiting beads 1112 is consistent. After each section of the support member 1111 is sleeved, it is necessary to adjust it by 90° and then re-sew the same number of limiting beads 1112 and support member 1111, and so on to complete the internal structure of the entire adjustable bending section 110. After completion, the bending gap is used to control the angle of the 110° curvature of the adjustable bending section. The larger the bending angle, the larger the bending gap, and vice versa.

[0078] Step S3: Fabricate support section 120;

[0079] Four sets of the second number of limiting beads 1112 are placed on the first through hole 1111a, the second through hole 1111b, the third through hole 1111c, and the fourth through hole 1111d of the support member 1111 to form the second skeleton unit 121. Several second skeleton units 121 are sequentially inserted into the traction assembly 200 that passes through the adjustable bending section 110. The difference between this step and step S2 is that it does not require adjusting the 90° insertion of the limiting beads 1112. Instead, the number of insertion of the limiting beads 1112 at the four ends is kept consistent. The fewer the insertions, the harder the support section 120 is, and vice versa. At the same time, the support member 1111 needs to be inserted after each section is completed. Its function is to protect the tube body from deformation or breakage during use so that it can maintain a good circular cavity during bending. Thus, the first semi-finished tube is obtained.

[0080] A number of round wires and a number of flat wires are provided, and the round wires and the flat wires are wound side by side around the support section 120 to obtain a first spring layer 122; 8 to 32 spindles of multi-strand metal wires are wound around the surface of the first spring layer to form a reinforcing layer; the multi-strand metal wires are wound on the surface of the first spring layer by a spring winding device, or woven in a mesh on the surface of the first spring layer by a weaving device.

[0081] Specifically, the four traction wires 220 of the traction assembly 200 are arranged in a ring at 90° intervals using tooling or equipment, and then glued and fixed one by one so that all four are on the same horizontal line without crossing or tangling. Then, the round wire and the flat wire are wound side by side using a spring winding device so that the four traction wires 220 can be firmly attached without displacement. After the spring winding is completed, the two ends of the winding wire are fixed with glue, and the excess wire is cut off using a laser welding machine.

[0082] The reinforcing layer can be prepared by winding 8-32 strands of multi-strand metal wire onto the surface using a multi-strand spring winding machine to form a second spring layer 123. This layer is defined as the reinforcing layer, and its purpose is to make the proximal end stronger and more resistant to bending. Finally, the wires at both ends are welded to the first spring layer 122 using a laser welding machine, and any excess wires are removed using a tool.

[0083] The reinforcing layer can also be made by braiding 8 to 32 strands of metal wire onto the surface using a braiding device to form a second braided layer 124. Then, the first and last strands of the surface layer are also welded off using a laser welding machine and welded to the first spring layer 122. Excess strands are then removed using a tool.

[0084] Step S4: Fabricate the inner and outer tubes;

[0085] An inner tube is provided, the inner tube being a thin tube made of a polymer material with high lubricity and ductility; the inner tube is inserted into the first semi-finished product to obtain a second semi-finished product tube.

[0086] Provide the outer tube material at the far end. The outer tube material at the far end is made of PU, TPU and PEBAX polymer composite tube. Its characteristics include flexibility, easy bending and strong recovery ability. After it is fitted, it is heated to 200℃~350℃ by a rheometer and then connected to the adjustable bending section 110 of the second semi-finished tube.

[0087] A proximal outer tube layer material is provided. The proximal outer tube layer is made of nylon and PEBAX polymer composite material, which has the characteristics of hardness and strong deformation resistance. After being fitted into the tube, it is heated to 200℃~350℃ to the surface of the second semi-finished tube support section 120 by a rheometer to obtain the main tube 100.

[0088] After all the outer tube materials and inner structure are made, the traction wire 220 at the end of the support section 120 can be pulled. At this time, it can be seen that each time the traction wire 220 at one end is adjusted, the adjustable bending section 110 will bend in the direction of stretching. After the stretching force is released, the adjustable bending section 110 will naturally return to its initial state.

[0089] Step S5: Outer coating:

[0090] Clean the main tube 100 obtained in step S4 with an ultrasonic cleaner, then apply a layer of primer solution to the surface of the main tube 100, cure it with a curing device and let it dry for about half an hour, then immerse the cured primer tube 100 in the top coat solution, and cure it again with a curing device to make its surface more lubricated.

[0091] Step S6: Install handle 300;

[0092] Install the end of the main tube 100 away from the adjustable bend section 110 to the connection port of the handle 300, and connect the traction assembly 200 to the bend adjustment structure of the handle 300.

[0093] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A multidirectional adjustable bendable microcatheter, characterized in that, Including the main pipe and traction components; The main pipe has an adjustable bending section and a support section; The adjustable bending section is provided with a first skeleton assembly, which includes several first skeleton units connected in sequence. Each first skeleton unit includes two support members and several limiting beads. The limiting beads have through holes. The support members are annular structures, and the support members have first, second, third, and fourth through holes evenly distributed around their circumference. The first and third through holes are opposite to each other, and the second and fourth through holes are opposite to each other. The two support members are coaxially arranged, forming an adjustment gap between them. A first number of limiting beads are provided between two corresponding first through holes in the adjustment gap, and a first number of limiting beads are provided between two corresponding third through holes in the adjustment gap. The second and fourth through holes on the side of one support member away from the adjustment gap are each provided with a first number of limiting beads. The support section has four first channels evenly distributed for the traction assembly to pass through. The traction assembly includes four traction wires and a fixing ring. The ends of the four traction wires are all fixed to the end of the adjustable bending section by the fixing ring. The other ends of the four traction wires pass through the first skeleton assembly and the support section respectively, corresponding to the first through hole, the second through hole, the third through hole and the fourth through hole, and emerge from the end of the support section.

2. The multidirectional adjustable bendable microcatheter according to claim 1, characterized in that, The surface of the traction wire is covered with a covering tube, which includes a proximal covering tube and a distal covering tube connected to each other. The proximal covering tube is disposed within the support section, and the distal covering tube is disposed within the adjustable bending section.

3. The multidirectional adjustable bendable microcatheter according to claim 2, characterized in that, The support section is provided with a second skeleton assembly, which includes a number of second skeleton units connected in sequence. Each second skeleton unit includes a support member and a number of limiting beads. The first through hole, the second through hole, the third through hole and the fourth through hole of the support member are each provided with a second number of limiting beads, so that the first through hole, the second through hole, the third through hole and the fourth through hole of the limiting beads respectively form four first channels.

4. A multidirectional adjustable bendable microcatheter according to claim 2, characterized in that, The support section also includes a first spring layer and a second spring layer; the first spring layer is made of flat wire and round wire; the second spring layer is made of 8 to 32 strands of springs.

5. A multidirectional adjustable bendable microcatheter according to claim 2, characterized in that, The support section also includes a first spring layer and a second braided layer; the first spring layer is made of flat wire and round wire; the second braided layer is made of multi-strand braided wire of 8 to 32 spindles.

6. A multidirectional adjustable bendable microcatheter according to claim 2, characterized in that, The main pipe also includes an inner pipe layer and an outer pipe layer, and the adjustable bending section and the support section are disposed between the inner pipe layer and the outer pipe layer; The inner tube layer is made of a polymer material with high lubricity and ductility; the outer tube layer sleeved on the outer periphery of the adjustable bending section is made of a flexible polymer composite material; and the outer tube layer sleeved on the outer periphery of the support section is made of a polymer composite material with higher hardness. The fixing ring and the support are made of a metallic material with non-transmittent linearity.

7. A multidirectional adjustable bendable microcatheter according to claim 1, characterized in that, It also includes a handle connected to the end of the support section; the handle includes a bending adjustment structure connected to the traction assembly, used to control the curvature of the adjustable bending section by pulling the traction wire.

8. A method for manufacturing a multidirectional adjustable bendable microcatheter, characterized in that, Includes the following steps, Fabrication of a traction assembly: A distal end covering tube, a proximal end covering tube, and traction wires are provided. The ends of the distal end covering tube and the proximal end covering tube are connected. The traction wires are threaded through the distal end covering tube and the proximal end covering tube, resulting in four traction wires with covering tubes on their surfaces. A fixing ring is provided, and the ends of the four traction wires that extend from the proximal end covering tube are evenly distributed and fixed around the fixing ring, thus obtaining the traction assembly. Fabrication of an adjustable bending section: Several metal rings are provided, with first, second, third, and fourth through holes evenly distributed around their circumference. The first and third through holes are positioned opposite each other, as are the second and fourth through holes, forming a support member. Several limiting beads with internal through holes are provided. Two support members are coaxially arranged, forming an adjustment gap between them. A first number of limiting beads are placed between corresponding first through holes and between corresponding third through holes in the adjustment gap. A first number of limiting beads are placed on the second and fourth through holes on the side of one support member away from the adjustment gap, respectively, forming a first skeleton unit. Several first skeleton units are sequentially fitted onto the traction assembly using four traction wires with covered tubes on their surfaces, corresponding to the first, second, third, and fourth through holes, respectively, to form an adjustable bending section. At this point, the remaining part of the traction assembly protrudes from the adjustable bending section. Manufacturing the support section: Place four sets of the second number of limiting beads on the first through hole, second through hole, third through hole and fourth through hole of the support member to form a second skeleton unit; insert several second skeleton units into the traction assembly that passes through the adjustable bending section to obtain the first semi-finished tube. Fabrication of inner and outer tubes: An inner tube is provided, which is a thin tube made of a polymer material with high lubricity and ductility; the inner tube is inserted into a first semi-finished product to obtain a second semi-finished product tube; a distal outer tube material is provided, which is composed of a flexible polymer composite material; the distal outer tube material is rheoformed onto the adjustable bending section of the second semi-finished product tube; a proximal outer tube material is provided, which is composed of a polymer composite material with high hardness; the proximal outer tube material is rheoformed onto the surface of the support section of the second semi-finished product tube; a main tube is obtained. Install the handle: Install the end of the main tube away from the adjustable bend section to the handle connection port, and connect the traction component to the bend adjustment structure of the handle.

9. A method for manufacturing a multidirectional adjustable bendable microcatheter according to claim 8, characterized in that, The process of fabricating the support segment also includes the following steps: A number of round wires and a number of flat wires are provided, and the round wires and the flat wires are wound side by side around the support section to obtain a first spring layer; 8 to 32 spindles of multi-strand metal wires are provided, and the multi-strand metal wires are wound onto the surface of the first spring layer through a spring winding device to form a second spring layer.

10. A method for manufacturing a multidirectional adjustable bendable microcatheter according to claim 8, characterized in that, The process of fabricating the support segment also includes the following steps: A number of round wires and a number of flat wires are provided, and the round wires and the flat wires are wound side by side around the support section to obtain a first spring layer; 8 to 32 spindles of multi-strand metal wires are provided, and the multi-strand metal wires are woven into the first spring layer by a braiding device to form a second braided layer.

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