A tube structure unit, a tube structure and a micro guide wire

Abstract

This invention discloses a tubular structural unit, a tubular structure, and a microguidewire, relating to the field of medical device technology. The tubular structural unit includes at least two sets of cutting structures, each set having a cutting portion and a connecting portion, with the connecting portions of adjacent sets of cutting structures sequentially staggered; or it includes at least three sets of cutting structures, each set having at least two cutting portions and at least two connecting portions, with the connecting portion of any set of cutting structures sequentially staggered from the corresponding connecting portions of the preceding and following sets. A tubular structure for a microguidewire comprises at least one segment of the aforementioned single-connecting-part structural unit and / or multi-connecting-part structural unit. This invention, through the staggered arrangement of connecting portions and the combination design of single or multiple connecting portions, reduces the bending stiffness at the tip, achieves multi-directional uniform bending and axial tensile capacity, balances torsional transmission and radial support, avoids the window sill effect caused by abrupt changes in stiffness, and improves the safety and maneuverability of the microguidewire.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a tubular structural unit, a tubular structure, and a microguidewire. Background Technology

[0002] Microguidewires are crucial tools in interventional procedures used to guide catheters or other instruments to the target blood vessel. During the procedure, the guidewire needs to be advanced and withdrawn multiple times within the tortuous vessel, and the flexibility and fracture resistance of its tip directly affect the safety of the procedure. Currently, the widely used hypotube-structured microguidewire in clinical practice employs a symmetrical double-beam cutting design at its distal end. That is, at each axial position, the tube wall forms two 180° symmetrically distributed uncut segments (connection sections) in the circumferential direction, and the flexibility is adjusted by changing the groove density.

[0003] However, existing symmetrical double-beam hypotubes have the following technical problems: Excessive tip stiffness: Even with increased groove density, the tip stiffness remains higher than that of the distal spring-structured microguidewire, posing a higher risk of damage to the blood vessel wall.

[0004] Stress concentration is prone to occur when bending: Since the two symmetrical uncut segments in each row are stretched when bending, stress concentration is obvious, and hypotube rupture is prone to occur in extremely curved blood vessels.

[0005] Poor axial tensile properties: The symmetrical double-beam structure is basically not stretchable. When the product is stretched, the core wire and the hyaluronic acid tube may break at the same time, posing a risk of scratching or puncturing blood vessels.

[0006] Therefore, there is an urgent need for a hyaluronic acid tube structure that can reduce the stiffness of the tip, bend uniformly in multiple directions, and have good axial tensile properties.

[0007] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0008] The purpose of this invention is to provide a tube structure unit, tube structure and microguidewire to solve the problems existing in the prior art, which can reduce the hardness of the tip, bend uniformly in multiple directions and have good axial tensile properties.

[0009] To achieve the above objectives, the present invention provides the following solution: A tube structure unit includes at least two sets of cutting structures, each set of cutting structures including a cutting portion and a connecting portion formed along the circumference of the tube; at least two sets of cutting structures are arranged side by side in sequence along the axial direction of the tube structure unit, and the connecting portions of adjacent sets of cutting structures are staggered in a clockwise or counterclockwise direction in the circumferential direction.

[0010] The present invention also provides another tube structure unit, including at least three sets of cutting structures, each set of cutting structures including at least two cutting portions and at least two connecting portions formed along the circumference of the tube; the at least three sets of cutting structures are arranged side by side in sequence along the axial direction of the tube structure unit, and the connecting portion of any set of cutting structures is staggered in the circumferential direction from the connecting portions of the preceding and following sets.

[0011] In an exemplary embodiment, in each group of at least two connecting portions of the cutting structure, the cutting portion between two adjacent connecting portions is designated as a reference segment A; in at least three groups of the cutting structures arranged in parallel along the axial direction of the tube structure unit, the length of the reference segment A gradually increases, gradually decreases, or remains unchanged.

[0012] The present invention also provides a tube structure for a microguidewire, characterized in that: it includes at least one single-connection tube structure unit as described in any one of claims 1-2 and / or at least one multi-connection tube structure unit as described in any one of claims 3-5; wherein, the tube structure unit as described in any one of claims 1-2 is referred to as a single-connection structure unit, and the tube structure unit as described in any one of claims 3-5 is referred to as a multi-connection structure unit.

[0013] In an exemplary embodiment, when the number of the tube structure units is N, and N is an integer greater than or equal to two, the N tube structure units are connected sequentially along the axial direction of the tube structure, and the flexibility of the N tube structure units gradually decreases from the distal end to the proximal end of the tube structure.

[0014] In one exemplary embodiment, the tube structure includes a single-connector structural unit, at least one gradient-type multi-connector structural unit, and at least one symmetrical multi-connector structural unit arranged sequentially from its distal end to its proximal end; wherein, In the single connection structural unit, the connection parts of any two adjacent sets of cutting structures are staggered by the same angle in the circumferential direction. At least one of the aforementioned gradient multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts. The circumferential lengths of the cutting parts in the first to Nth segments of the cutting structure gradually approach equal lengths, the circumferential angle between the two connecting parts gradually increases, and the connecting parts in the first to Nth segments of the cutting structure are successively offset by the same angle in the circumferential direction. At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first to the Nth segments are staggered by the same angle in the circumferential direction.

[0015] In one exemplary embodiment, the tube structure includes at least one symmetrical multi-connection structural unit, at least one asymmetrical multi-connection structural unit, at least one gradient multi-connection structural unit, and at least one symmetrical multi-connection structural unit arranged sequentially from its distal end to its proximal end; wherein, At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first segment to the Nth segment are staggered by the same angle in the circumferential direction. At least one section of the asymmetric multi-connection structure unit includes a first section, a second section, ..., an Nth section arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts, and the circumferential lengths of the two cutting parts are not equal. The connecting parts in the cutting structures of the first to the Nth sections are staggered by a preset angle in the circumferential direction. At least one of the aforementioned gradient multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts. The circumferential lengths of the cutting parts in the first to Nth segments of the cutting structure gradually approach equal lengths, the circumferential angle between the two connecting parts gradually increases, and the connecting parts in the first to Nth segments of the cutting structure are successively offset by the same angle in the circumferential direction.

[0016] In one exemplary embodiment, the tube structure includes at least one symmetrical multi-connector structural unit, one spirally cut segment, one single-connector structural unit, one transitional multi-connector structural unit, and at least one symmetrical multi-connector structural unit arranged sequentially from its distal end to its proximal end; wherein, At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first segment to the Nth segment are staggered by the same angle in the circumferential direction. The spiral cutting section is a continuous spiral groove, which makes the tube section form a spring-like structure; Each set of cutting structures in the transitional multi-connection structural unit includes two connecting parts and two cutting parts; wherein, the two connecting parts in each set of cutting structures are symmetrically distributed around one of the connecting parts in the last set of cutting structures in the previous single-connection structural unit, and the circumferential angle between the two connecting parts in each set of cutting structures gradually increases from the far end to the near end until they are symmetrically distributed at 180°.

[0017] In an exemplary embodiment, the proximal wall of the tube structure is further provided with a honeycomb-shaped perforated pattern, which is composed of multiple interconnected honeycomb units; the honeycomb units are selected from at least one of hexagonal, quadrilateral, triangular, rectangular, circular, concave hexagonal, double V-shaped, chiral structure or star-shaped.

[0018] The present invention also provides a microguidewire, characterized in that it includes the tubular structure described in any one of claims 6-11.

[0019] The present invention achieves the following technical effects compared to the prior art: The tube structure unit of claim 1, by providing at least two sets of cutting structures, each set having only one connecting part and one cutting part, and the connecting parts of adjacent sets being staggered sequentially, achieves the following beneficial effects: 1. Significantly reduced tip bending stiffness. Because each group has only one connection point, only that single connection point bears tensile strain during bending, avoiding the significant bending resistance caused by the simultaneous tension of two connection points in a traditional symmetrical double-beam structure. Finite element analysis shows that the bending stiffness of this structure can be reduced by approximately 90% compared to the traditional symmetrical double-beam structure, thereby significantly reducing the risk of damage to the blood vessel wall from the microguidewire tip.

[0020] 2. Achieve uniform bending in multiple directions. By staggering adjacent sets of connectors, the connectors can be distributed in a spiral pattern along the axial direction. When the stagger angle is selected appropriately (e.g., 90°), the connectors are evenly distributed across all circumferential phases, making the bending resistance of the tube body essentially equal in any lateral direction. This avoids the bending anisotropy caused by connectors being distributed only along a straight line or only diagonally in existing single-connector designs, allowing the guidewire to adapt to the complex three-dimensional orientation of blood vessels.

[0021] 3. Imparts axial tensile capacity to the tube. In traditional symmetrical double-beam structures, the two connecting parts are 180° opposite each other in the circumferential direction. When subjected to axial tensile force, both connecting parts are stretched and mutually constrained, resulting in minimal overall elongation and a high risk of brittle fracture. In contrast, in a single-connector structure, the spirally distributed single connecting part can elastically elongate like a spring under axial tensile force, thereby absorbing energy and dispersing stress. When the external force exceeds the limit, the tube extends through plastic deformation rather than suddenly fractures, significantly reducing the risk of the guidewire stump puncturing blood vessels after breakage.

[0022] 4. Simplified design and easier manufacturing. The single-connection structure only requires controlling two main parameters: the width of the connection and the misalignment angle, which allows for a wide range of stiffness adjustment, reducing the complexity of laser cutting path planning and facilitating mass production.

[0023] The tube structure unit of claim 2, by providing at least three sets of cutting structures, each set having at least two connecting parts and a corresponding number of cutting parts, and with adjacent sets of connecting parts arranged in a staggered manner, achieves the following beneficial effects: 1. Balancing Torque Transmission and Compliance: Compared to single-connector structures, multi-connector structures have multiple connections in the circumferential direction, significantly improving the torsional stiffness of the tube and enabling the transmission of rotation angle from the operating end to the tip at a near 1:1 ratio. Simultaneously, due to the increased number of connections, the width of each individual connection can be correspondingly reduced, thus achieving excellent torsional control performance without sacrificing excessive compliance. This is particularly crucial for neurointerventional surgeries requiring precise steering.

[0024] 2. Offers flexible stiffness gradient design. By adjusting the number and width of the connectors, as well as the offset angle between adjacent groups, the bending and torsional stiffness of the tube at various axial positions can be precisely controlled. For example, fewer connectors (e.g., 2) can be used at the distal end to achieve higher compliance, while more connectors (e.g., 3 or 4) can be used at the proximal end to achieve stronger support, thus achieving a continuous gradient from the distal to the proximal end.

[0025] 3. Enhanced radial support. The multi-connection structure has multiple support points in the circumferential direction. When the tube is subjected to radial compressive load, these connections work together to resist deformation, preventing the hypotube from being crushed in tortuous blood vessels, ensuring the safety of the internal core wire and the patency of the instrument channel.

[0026] 4. Improved energy absorption and fracture resistance. The multi-connection structure distributes stress across multiple connections, preventing stress concentration at a single connection. During bending or tension, each connection deforms sequentially or collaboratively, absorbing energy through plastic deformation at multiple locations. This delays crack initiation and propagation, thereby improving the fatigue life and fracture toughness of the tube.

[0027] The tubular structure for microwires as described in claim 4, by comprising at least one single-connector structural unit and / or at least one multi-connector structural unit, achieves the following beneficial effects: 1. Customizable mechanical properties across the entire length range. Designers can flexibly choose the combination, sequence, and length of single and multiple connector units based on the curvature of the target vessel, the location of the lesion, and operational habits. For example, a single connector unit can be placed at the tip to achieve ultimate flexibility and axial tensile strength, while multiple connector units can be placed at the proximal end to achieve good torsional control and support. Transition units can be placed in the middle to achieve a smooth connection. This modular design allows for the development of multiple performance specifications from the same hypoem tube blank, reducing product development costs.

[0028] 2. Eliminating the "windowsill effect" caused by abrupt changes in stiffness. By sequentially connecting single-connector units and multi-connector units along the axial direction, and maintaining the continuity of the misalignment pattern at the connection points (e.g., the same misalignment angle and consistent rotation direction), the bending stiffness of the entire tube can increase monotonically and smoothly from the distal to the proximal end, without any obvious steps. This avoids the phenomenon in conventional designs where abrupt changes in stiffness cause other instruments (such as microcatheters) to become stuck or push the guidewire to detach during advancement, thus improving the smoothness and safety of the surgery.

[0029] 3. Balancing fracture safety and connection reliability. The axial tensile capacity provided by the single-connection unit allows the tube to undergo plastic elongation without immediate fracture when subjected to accidental overstretching, protecting the patient. Simultaneously, the numerous and evenly distributed connections in the multi-connection unit facilitate the formation of a strong connection with the core wire through welding or bonding, avoiding stress concentration at a single connection point that could lead to connection failure.

[0030] 4. Adaptable to various microwire types. This tube structure can be used in neural microwires that require extremely high tip flexibility (largely using single connector units), as well as coronary artery microwires that require strong torsional control performance (mainly using multi-connector units), and also in general-purpose microwires (a combination of both).

[0031] In summary, this invention addresses the technical challenges of existing hypotubes, such as excessive stiffness at the tip, limited bending direction, lack of axial stretchability, and uneven stiffness transition, by addressing the basic structural unit, reinforced structural unit, and combined tube structure. This results in a comprehensive range of beneficial effects, including reducing the risk of vascular injury, improving bending adaptability, enhancing fracture safety, and optimizing surgical maneuverability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a plan view of the tubular structure unit disclosed in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the tube structure unit disclosed in Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the tube structure for microguidewire disclosed in Sub-Example 1 of Embodiment 3 of the present invention; Figure 4 This is a schematic diagram of the tube structure for microguidewire disclosed in sub-example two of embodiment three of the present invention; Figure 5 This is a schematic diagram of the tube structure for microguidewire disclosed in sub-example three of embodiment three of the present invention; Figure 6 This is a schematic diagram of the hexagonal honeycomb-shaped hollow pattern disclosed in Embodiment 3 of the present invention; Figure 7 This is a schematic diagram of the diamond-shaped honeycomb hollow pattern disclosed in Embodiment 3 of the present invention; Among them, 1. Cutting structure; 101. Cutting part; 102. Connecting part; 2. Tube structure; 201. Single connecting part structural unit; 202. Multi-connecting part structural unit; 2021. Gradient multi-connecting part structural unit; 2022. Symmetrical multi-connecting part structural unit; 2023. Asymmetrical multi-connecting part structural unit; 2024. Spiral cutting segment; 203. Honeycomb hollow pattern. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] The purpose of this invention is to provide a tube structure unit, tube structure and microguidewire to solve the problems existing in the prior art, which can reduce the hardness of the tip, bend uniformly in multiple directions and have good axial tensile properties.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] It should be noted that, throughout this instruction manual, "distal" generally refers to the end of the microguidewire or hypotube that is furthest from the operator and closer to the lesion during interventional surgery, while "proximal" refers to the end closer to the operator. "Circumferential" refers to the direction along the circumference of the tube, and "axial" refers to the direction along the central axis of the tube. "Cut section" refers to the hollowed-out groove or opening formed on the wall of the hypotube by laser cutting, chemical etching, or mechanical processing, and "connecting section" refers to the uncut portion of the tube wall between adjacent cut sections, also known as the "uncut segment" or "rod." Unless otherwise specified, the angle values ​​appearing in the description refer to the central angle corresponding to the arc segment.

[0038] Furthermore, since the core wire, tip spring sheath, coating, and push rod of the microguidewire are mature existing technologies in this field, they will not be described in detail in this embodiment. Only the innovative and improved tube structure (hypophthalmic tube) will be described in detail. It should be understood that by combining the hypophthalmic tube containing the tube structure of this invention with conventional core wires, tip structures, etc., the microguidewire of this invention can be obtained.

[0039] Example 1 like Figure 1 As shown, this embodiment first provides a pipe structure unit. This pipe structure unit includes at least two sets of cutting structures 1. Here, "cutting structure" refers to a specific combination of an opening (i.e., a cut portion 101) formed circumferentially on the pipe wall at a certain position along the pipe's axial direction, and the remaining solid portion (i.e., a connecting portion 102). Each set of cutting structures 1 includes a cut portion 101 and a connecting portion 102 formed circumferentially on the pipe. In other words, on a certain circumferential cross-section of the pipe, only one connecting portion 102 (an uncut solid segment) connects the upstream and downstream sides of the pipe wall; the remaining parts are all empty cut portions 101. At least two such sets of cutting structures 1 are arranged side-by-side sequentially along the axial direction of the pipe structure unit, and the connecting portions 102 of adjacent sets of cutting structures 1 are staggered circumferentially.

[0040] In this embodiment, "parallel arrangement" means that the cutting structures 1 are arranged one after another in the axial direction. They can be adjacent to each other (i.e., there is no additional non-grooved segment between two adjacent cutting structures 1) or separated by a small non-grooved cylindrical segment. To obtain better compliance, they are usually arranged adjacently so that the cutting parts 101 are continuously distributed.

[0041] The "misalignment" refers to the circumferential offset of the connecting portion 102 of the latter group of cutting structures 1 relative to the connecting portion 102 of the former group of cutting structures 1. This offset angle can be any non-zero angle, such as 30°, 45°, 60°, 90°, 120°, etc. Through this misalignment, when the tube is subjected to bending loads, the connecting portions 102 at different axial positions distribute the bending stress, preventing stress concentration along a straight line, thereby improving the bending fatigue life of the tube. Simultaneously, since each group has only one connecting portion 102, the tube has a spring-like tensile capacity in the axial direction. When subjected to axial tension, the cutting portions 101 between the connecting portions 102 can open, achieving elastic elongation.

[0042] As a viable material option, the tube structure unit can be manufactured from nickel-titanium alloy (NiTi) tubes via laser cutting. NiTi alloys possess superelasticity and good biocompatibility, making them a commonly used material for manufacturing sodium hypochlorite tubes. After cutting, heat treatment can be performed to eliminate residual stress. The aforementioned laser cutting and heat treatment processes for NiTi tubes are mature existing technologies in this field and will not be elaborated upon here.

[0043] As a preferred embodiment, the connecting portions 102 of two adjacent sets of cutting structures 1 are staggered in a clockwise or counterclockwise direction in the circumferential direction. That is, when viewed from the far end (the end closer to the guide wire tip) to the proximal end (the end closer to the operator) of the tube structure unit, the circumferential position of the connecting portion 102 gradually shifts in a uniform rotation direction (clockwise or counterclockwise).

[0044] The offset angle can be set arbitrarily as needed. For example, it can be set to offset 90° each time, so that after four sets of cutting structures 1, the connecting part 102 rotates exactly one revolution, resulting in uniform bending stiffness of the tube in four orthogonal directions. Alternatively, it can be set to offset 45° each time, so that after eight sets of cutting structures 1, it rotates one revolution, achieving a smoother stiffness distribution. The size of the offset angle directly affects the compliance and torsional performance of the tube structural unit: when the offset angle is small (e.g., 15°~30°), the tube is easier to torsion, but the bending stiffness may exhibit anisotropy; when the offset angle is large (e.g., 90°), the bending isotropy is better.

[0045] It is important to note that the definition of the misalignment angle is based on the direction of rotation. From a circumferential perspective, if clockwise is considered positive, then the subsequent connecting part 102 rotates clockwise by an angle θ (0° < θ < 360°) relative to the preceding connecting part 102. When θ is less than 180°, it visually appears as a clear clockwise spiral; when θ equals 180°, the connecting part 102 rotates to the opposite side, resulting in the same clockwise and counterclockwise effect; when θ is greater than 180°, since "clockwise rotation θ" is equivalent to "counterclockwise rotation (360° - θ)," it visually presents a counterclockwise spiral effect, but from the defined direction of rotation, it still falls under clockwise misalignment. For example, setting a clockwise misalignment of 270° is equivalent to a counterclockwise misalignment of 90°. Designers can choose either description method based on process convenience or aesthetic requirements; those skilled in the art should understand that these two expressions are equivalent in this embodiment.

[0046] In one specific implementation, to achieve uniform bending performance in four directions, it is preferable to set adjacent misalignment angles to be 90°, and rotate them sequentially in a clockwise direction. At this time, the connecting portion 102 of the first set of cutting structures 1 is located at the 0° phase (e.g., the top of the tube cross-section), the second set is located at the 90° phase (the rightmost), the third set is located at the 180° phase (the bottom), the fourth set is located at the 270° phase (the leftmost), the fifth set returns to the 0° phase, and so on. In this way, the bending resistance of the tube in the four directions is essentially equal, adapting to the three-dimensional bending path within the blood vessel.

[0047] In another embodiment, to achieve specific unidirectional bending performance (e.g., the guidewire needs to bend preferentially in a certain direction to pass through specific anatomical structures), the misalignment angle can be set to 180°. In this case, the connector 102 alternates between two opposite phases, and the tube can be easily bent only in the planes containing those two directions, while the bending stiffness is greater in the plane perpendicular to them. This embodiment can be used for guidewire designs with certain special requirements.

[0048] Based on the above implementation scheme, the misalignment angle can adopt different constant values ​​in different sections. For example, a larger misalignment angle (e.g., 90°) can be used at the distal end (head end) of the tubular structural unit to obtain isotropic compliance, while a smaller misalignment angle (e.g., 30°) can be used at the proximal end to maintain good torsional response. This segmented constant angle design is also a specific implementation scheme of this embodiment, as long as the misalignment between adjacent groups in each locality is constant (i.e., local equal-angle misalignment). However, for the sake of simplicity, this specific implementation scheme mainly describes an example of global equal-angle misalignment.

[0049] Furthermore, when the misalignment angle is set to greater than 180°, as mentioned above, the actual effect is equivalent to a reverse misalignment of less than 180°. Those skilled in the art can choose specific values ​​as needed. For example, setting a clockwise misalignment of 270° effectively creates a counter-clockwise 90° spiral. In manufacturing, if the laser cutting path facilitates continuous, large-angle rotation in the same direction, a large-angle misalignment can be used. Therefore, this invention explicitly includes misalignment angles greater than 180° within its scope of protection.

[0050] Example 2 This embodiment provides another tube structure unit, which differs from Embodiment 1 in that each group of cutting structures 1 includes at least two cutting portions 101 and at least two connecting portions 102 formed along the circumference of the tube; and the number of groups of cutting structures 1 is at least three. That is, at a certain axial position of the tube, the solid connecting portions 102 are no longer one, but two or more (e.g., three, four, six, etc.), which divide the tube wall into a corresponding number of cutting portions 101. These connecting portions 102 are distributed at intervals in the circumferential direction and jointly bear bending and torsional loads.

[0051] At least three sets of such cutting structures 1 are arranged side by side along the axial direction, and the connecting part 102 of any set of cutting structures 1 is staggered from the connecting parts 102 of the preceding and following sets. Here, "staggered" means that for a specific connecting part 102 in the preceding set, the corresponding connecting part 102 in the following set (i.e., the connecting part 102 that is functionally or sequentially the same) is offset circumferentially. Since each set has multiple connecting parts 102, the staggered relationship is more complex, but the basic idea is to gradually rotate the position of the connecting parts 102 along the axial direction to avoid forming straight "ribs," thereby dispersing stress.

[0052] In a simplest embodiment, each group of cutting structures 1 includes two connecting portions 102 and two cutting portions 101. The two connecting portions 102 are distributed at a certain angle (e.g., 90°, 120°, or 180°) in the circumferential direction. Between two adjacent groups, the two connecting portions 102 of the previous group are considered as a whole pattern, and the pattern of the next group is rotated by an angle (e.g., 30°). In this way, the connecting portions 102 of any group of cutting structures 1 are misaligned with the connecting portions 102 of its adjacent groups. When the number of groups is greater than or equal to three, this misalignment relationship forms a continuous spiral pattern.

[0053] In another embodiment, each set of cutting structures 1 includes three connecting portions 102 and three cutting portions 101, with the three connecting portions 102 being 120° apart. Between adjacent sets, the three connecting portions 102 are rotated as a whole by a certain angle (e.g., 20°). In this way, the tube body has uniform mechanical properties in three directions.

[0054] The main advantage of the multi-connector 102 structure over the single-connector 102 structure is that it can provide higher radial support while maintaining good torsional stiffness and torque transmission efficiency, and the mechanical properties can be finely adjusted by adjusting the number, width and misalignment angle of the connectors 102.

[0055] In a preferred embodiment, the connecting portions 102 of two adjacent sets of cutting structures 1 are staggered sequentially in a clockwise and / or counterclockwise direction in the circumferential direction. Similar to the above scheme, the staggering direction here can be a single clockwise or counterclockwise direction, or it can be clockwise in some sections and counterclockwise in other sections. Since the structure of multiple connecting portions 102 is relatively complex, the choice of staggering direction will affect the consistency of the torsional direction of the tube. Generally, in order to ensure the linear response of torque transmission, it is preferable to adopt a sequential staggering in a single direction (e.g., all clockwise).

[0056] The expression "and / or" means that the rotation can be entirely clockwise, entirely counterclockwise, or partially clockwise and partially counterclockwise. For example, a clockwise offset can be used at the distal end to obtain more compliant bending performance, while a counterclockwise offset can be used at the proximal end to obtain a stiffer torsional response. Both methods are within the scope of protection of this invention.

[0057] The misalignment angle can also be set arbitrarily. For a multi-connector 102 structure, the value of the misalignment angle can be defined separately relative to each connector 102, or the entire group of connectors 102 can be rotated as a rigid body. In a preferred embodiment of the present invention, the entire group of connectors 102 is rotated by a fixed angle, so that the relative positions of all connectors 102 remain unchanged, which is convenient for design and manufacturing.

[0058] Based on the above implementation scheme, the concept of "reference segment A" is further introduced, and its length is allowed to gradually change along the axial direction. Specifically, in each group of cutting structures 1, two adjacent connecting parts 102 are selected, and the cutting part 101 between them is defined as reference segment A. In at least three groups of cutting structures 1 arranged side by side along the axial direction, the length of reference segment A gradually increases, gradually decreases, or remains unchanged.

[0059] The length of reference segment A directly determines the flexibility of the pipe wall at that point: the longer reference segment A (i.e., the longer the arc of the cut section 101), the larger the cut area, the relatively thinner and weaker the remaining connecting section 102, and the easier it is for the pipe to bend in that section; conversely, the shorter reference segment A, the stiffer the pipe. By controlling the axial variation trend of reference segment A, the stiffness gradient of the pipe can be precisely designed.

[0060] The following section elaborates on the variation pattern of the reference segment A and the corresponding changes of other cutting segments 101 for different numbers of connecting parts 102.

[0061] (1) Case of two connecting parts 102 When each set of cutting structures 1 contains exactly two connecting parts 102, there are two cutting parts 101 in the circumferential direction (i.e., the gap between the two connecting parts 102). Let one cutting part 101 be designated as the reference segment A, and the other cutting part 101 be called the "follower segment B". Since the total circumferential length of the tube (360°) minus the sum of the arc lengths of the two connecting parts 102 equals the sum of the arc lengths of the two cutting parts 101, the length of the follower segment B changes accordingly with the length of the reference segment A. Specifically, if the arc lengths of the two connecting parts 102 remain constant, then when the reference segment A increases, the follower segment B must decrease; and vice versa. If the arc length of the connecting part 102 can also be variable, then the change in the follower segment B must also consider the change in the arc length of the connecting part 102. However, usually, to simplify the design, the width of the connecting part 102 can be set to be constant or vary according to another rule.

[0062] For example, in one specific embodiment, the arc length of both connecting portions 102 is set to 20° and remains constant. Then the sum of the arc lengths of the reference segment A and the follower segment B is 360° - 40° = 320°. If the reference segment A gradually increases from 10° to 150° from the distal end to the proximal end, then the follower segment B gradually decreases from 310° to 170°. In this way, the flexibility distribution of the tube will gradually soften as the reference segment A increases (because the longer cutting portion 101 is easier to bend), or if the follower segment B is the main stress area, it needs to be determined based on actual stress analysis. A more common design is to gradually decrease the reference segment A (i.e., shorten the cutting portion 101), thereby making the tube gradually stiffer from the distal end to the proximal end, which meets the requirement of a soft distal end and support proximal end for the microguidewire.

[0063] Alternatively, the reference section A can remain unchanged, for example, at a constant 80°, while the flexibility can be adjusted by changing the width of the connecting part 102 or other parameters.

[0064] (2) Case of three connecting parts 102 When each set of cutting structures 1 includes three connecting parts 102, three cutting parts 101 are formed circumferentially. At this time, two reference segments can be set, such as reference segment A and reference segment B. Reference segment A and reference segment B can each independently increase, decrease, or remain unchanged along the axial direction. The length of the remaining third cutting part 101 (called the follower segment C) is determined by subtracting the sum of the arc lengths of the three connecting parts 102 and the arc lengths of reference segments A and B from the total circumferential length.

[0065] For example, if the arc length of each of the three connecting sections 102 is set to 10° and remains constant, then the total arc length of the cutting section 101 is 330°. If the reference section A gradually increases from 20° to 100° from the distal end to the proximal end, while the reference section B gradually decreases from 50° to 10°, then the length of the follower section C is 330° - AB, and its variation trend depends on the combined effect of A and B. This multi-reference section design allows for more flexible adjustment of the stiffness distribution of the tube in different bending directions. For example, by varying the reference sections unevenly, the bending stiffness of the tube in one direction can be significantly less than in other directions, thereby directionally guiding the bending path of the guidewire.

[0066] This embodiment explicitly covers the case where two or more reference segments are set. As long as the length of at least one reference segment along the axial direction changes regularly, it will fall within the protection range regardless of how other cutting segments change.

[0067] (3) Cases with four or more connecting parts 102 For four connecting parts 102, three reference segments (A, B, C) can be set, and the fourth cutting segment is a follower segment; for N connecting parts 102, N-1 reference segments and one follower segment can be set. Those skilled in the art can select any number of reference segments for length gradient design as needed. For the sake of brevity, this specification will not exhaustively list them, but it should be understood that all these permutations and combinations are within the concept of this invention.

[0068] (4) Specific numerical examples of changes in the length of the reference segment In one embodiment of a tubular structure unit for a microguidewire, 30 sets of cutting structures 1 are arranged axially from the distal (proximal) end to the proximal end. Each set has two connecting parts 102 (with a constant arc length of 10°). The length of the reference segment A linearly increases from 5° in the first set to 155° in the 30th set, with an increment step of (155-5) / 29≈5.17°. The length of the follower segment B linearly decreases from 315° to 165°. Finite element analysis shows that this design achieves a proximal bending stiffness of approximately 1 / 30 of the proximal bending stiffness, resulting in a smooth transition and avoiding stress concentration. This example is for illustrative purposes only; actual values ​​can be adjusted according to clinical needs.

[0069] In a multi-connection structure unit 202 having at least two connection portions 102, in order to obtain a regular spiral pattern and uniform mechanical properties, it is preferable that the misalignment angle between any connection portion 102 in the latter group of cutting structures 1 and the corresponding connection portion 102 in the former group of cutting structures 1 is equal. Here, "corresponding connection portion 102" refers to a connection portion 102 that is in the same relative position in the same group of cutting structures 1 (e.g., numbered 1st, 2nd, ... kth connection portion 102 in circumferential order).

[0070] For example: Assume each group of cutting structures 1 contains two connecting parts 102, denoted as a and b respectively. In the first group, connecting part 102 a1 is located at a circumferential angle of 0°, and connecting part 102 b1 is located at a circumferential angle of 90° (i.e., a1 leads b1 by 90°). In the second group, the connecting part 102 corresponding to a1 is defined as a2, and the connecting part corresponding to b1 is defined as b2. If the misalignment angle α = 30° is set, then a2 is located at 30°, and b2 is located at 120° (still maintaining a 90° difference from a2). In the third group, a3 is located at 60°, b3 is located at 150°, and so on. Here, α = 30° is the misalignment angle of the corresponding connecting parts 102 in adjacent groups. At the same time, the angle between a1 and a2 is equal to the angle between a2 and a3 (both are 30°), and the angles between b1 and b2, and between b2 and b3 are also equal (also 30°). This design results in the entire multi-connection structural unit 202 exhibiting a spiral cutting pattern with equal pitch, leading to uniform mechanical properties.

[0071] In another embodiment, the misalignment angles of the two connecting parts 102 can be different: for example, the misalignment angle α from a1 to a2 is 30°, while the misalignment angle β from b1 to b2 is 45°. In the second group, a2 is at 30°, but to maintain the relative position of b2 to a2 (still a 90° difference), b2 will automatically be at 120°; however, if the individual misalignment angle of b1 to b2 is required to be 45°, it will conflict with the position of a2. Therefore, α=β is usually set to ensure that the relative positions of the connecting parts 102 within the group remain unchanged. However, it is also permissible for the relative positions within the group to vary axially, for example, the included angle of the connecting parts 102 in each group gradually changes, in which case α and β can be unequal.

[0072] In the case of three connecting parts 102, three independent misalignment angles α, β, and γ can be set, which can be equal or unequal. For example, α = 30°, β = 35°, and γ = 40° can be set, so that the distribution of connecting parts 102 in each group gradually changes, resulting in more complex mechanical properties. These are all optional embodiments of the present invention.

[0073] Example 3 This embodiment combines the aforementioned single-connector structural unit 201 (Embodiment 1) and multi-connector structural unit 202 (Embodiment 2) to form a tube structure 2 for a microguidewire. Specifically, the tube structure 2 includes at least one segment of single-connector structural unit 201 and / or at least one segment of multi-connector structural unit 202. Here, "and / or" means that the single-connector structural unit 201 can be used alone to constitute the entire tube structure 2, the multi-connector structural unit 202 can be used alone, or both can be used in combination.

[0074] For ease of description, in this embodiment, the pipe structure unit described in Embodiment 1 is referred to as "single connection structure unit 201", and the pipe structure unit described in Embodiment 2 is referred to as "multi-connection structure unit 202". It should be noted that the multi-connection structure unit 202 can be further subdivided into different subtypes, such as symmetrical type (two connection parts 102 are distributed at 180°), asymmetrical type (two cutting parts 101 have different lengths), and gradient type (the included angle of the connection parts 102 or the length of the cutting parts 101 changes along the axial direction), etc. These subtypes will be specifically defined in subsequent implementation embodiments.

[0075] In this embodiment, a typical tube structure 2 for a microguidewire can be a single-connector structural unit 201 and multiple multi-connector structural units 202 with different parameters connected sequentially from distal to proximal. The single-connector structural unit 201 provides the softest tip, while the multi-connector structural units 202 gradually transition to a stiffer proximal end. Another implementation uses all multi-connector structural units 202, but the multi-connector structural units 202 near the distal end have a smaller number of connectors 102 (e.g., 2 with a smaller included angle) and a longer cutting portion 101, while those near the proximal end have a larger number of connectors 102 (e.g., 4) and a shorter cutting portion 101.

[0076] This embodiment does not limit the specific number of segments, their arrangement order, or the gradual change pattern, as long as it includes at least one single-connection structural unit 201 and / or at least one multi-connection structural unit 202. Those skilled in the art can freely combine them according to the target clinical application (such as neurointervention, coronary artery intervention, etc.).

[0077] As a preferred embodiment, when the number N of the tube structure units is an integer greater than or equal to two, these N tube structure units are connected sequentially along the axial direction of the tube structure 2, and the flexibility of the N tube structure units gradually decreases from the far end to the near end of the tube structure 2.

[0078] Here, "gradually decreasing flexibility" means that from the distal (head) end to the proximal (end closer to the operator), the bending stiffness of each tubular structural unit gradually increases, meaning it becomes increasingly rigid. This gradual design is key to the microguidewire's excellent passage and support performance, avoiding the "step effect" or "windowsill effect" caused by abrupt changes in stiffness, and preventing guidewire prolapse or damage to blood vessels during advancement.

[0079] There are several ways to achieve a gradual decrease in softness, including but not limited to: Changing the length of the cut portion 101: In the single connection structure unit 201, the circumferential length of the cut portion 101 can be gradually reduced along the direction from the distal end to the proximal end (i.e., the width of the connection portion 102 can be increased), thereby reducing the flexibility.

[0080] Change the number of connecting parts 102: from a single connecting part (softest) to a double connecting part (harder), and then to a triple or quadruple connecting part (harder).

[0081] Changing the misalignment angle: In the single-connector 102 structure, a smaller misalignment angle (e.g., 30°) produces a denser spiral and slightly greater bending stiffness; a larger misalignment angle (e.g., 90°) is more flexible. Stiffness can be increased by decreasing the misalignment angle along the distal to proximal direction.

[0082] Changing the circumferential angle of the connecting part 102: For a double-connecting-part structure, the smaller the angle (e.g., 30°), the easier it is for the tube to bend in that plane, but the overall radial stiffness may be lower; the larger the angle (e.g., 180°), the more isotropic the tube becomes and the overall stiffness increases. Therefore, the angle between the two connecting parts 102 can be gradually increased along the direction from the distal end to the proximal end.

[0083] In one specific embodiment, a three-segment tubular structure unit is used: the first segment is a single-connector structure unit 201 with an adjacent misalignment angle of 90°, and the cut portion 101 is 340° long (equivalent to a 20° long connecting portion 102), exhibiting the highest flexibility; the second segment is a double-connector structure unit, with the two connecting portions 102 forming a 90° angle, and each connecting portion 102 being 30° long, with the cut portion 101 correspondingly reduced in size, exhibiting moderate flexibility; the third segment is a double-connector structure unit, with the two connecting portions 102 forming a 180° symmetrical shape, and each connecting portion 102 being 40° long, exhibiting the lowest flexibility. These three segments are connected sequentially, achieving a gradual increase in stiffness from the distal end to the proximal end.

[0084] Alternatively, all single-connector structural units 201 can be used, but the width of each connecting portion 102 gradually increases (i.e., the length of the cutting portion 101 gradually decreases), which can also achieve the effect of gradually decreasing flexibility. For example, the first connecting portion 102 is 10° long, the second connecting portion 102 is 20° long, and the third connecting portion 102 is 30° long.

[0085] All of the above-mentioned implementation methods fall within the protection scope of this invention, and those skilled in the art can determine the specific geometric parameters based on finite element analysis or experiments.

[0086] The following are three typical sub-implementation examples for detailed explanation.

[0087] Sub-example 1 In this example, the tube structure 2, along the direction from the distal (crown) end to the proximal (operating) end, is sequentially composed of a single-connector structural unit 201, at least one gradually tapering multi-connector structural unit 2021, and at least one symmetrical multi-connector structural unit 2022. Overall, the flexibility of this structure gradually decreases from the distal to the proximal end, that is, it is softest at the crown and hardest at the proximal end, thereby ensuring smooth passage through tortuous blood vessels while providing sufficient support for the advancement of subsequent instruments.

[0088] 1. Specific structure of single connection structural unit 201 The single-connection structural unit 201 refers to a section where each group of cutting structures 1 contains only one connecting part 102 and one cutting part 101, and the connecting parts 102 of adjacent groups of cutting structures 1 are staggered in the circumferential direction. This unit has extremely low radial stiffness and is axially stretchable, making it the core component for achieving ultra-flexible head ends.

[0089] In this embodiment, the length of the single connecting structural unit 201 can be set from 5 mm to 20 mm according to clinical needs. A typical embodiment is: the unit is 10 mm long and contains 40 sets of cutting structures 1 (with the same axial spacing between adjacent sets). In each set of cutting structures 1, the circumferential angle occupied by the cutting part 101 is 300° to 350°, and the corresponding connecting part 102 occupies 10° to 60°. In order to obtain uniform bending performance in four directions, the misalignment angle between adjacent connecting parts 102 is set to 90°, and they rotate sequentially in a clockwise direction. For example, if the circumferential angle of the cutting part 101 is 340°, the circumferential angle of the connecting part 102 is 20°, and the misalignment angle is 90°, then the first set of connecting parts 102 is located at 0° phase, the second set is located at 90°, the third set is located at 180°, the fourth set is located at 270°, the fifth set returns to 0°, and so on. When the tube is bent in any direction, the connecting part 102 appears alternately in different phases, which avoids excessive weakness in one direction. At the same time, since there is only one connecting part 102, the bending stiffness is only 10% to 20% of that of a traditional symmetrical double beam structure.

[0090] In another embodiment, to accommodate specific anatomical structures (such as the need for the guidewire to bend primarily within a single plane), the misalignment angle can be set to 180°. In this case, the connector 102 alternates between the 0° and 180° phases, and the tube is flexible only within the plane defined by these two phases, while maintaining greater stiffness in the vertical direction. This design reduces guidewire deflection in non-target directions.

[0091] Furthermore, the single-connection structural unit 201 itself can also be composed of multiple sub-segments, with the width or misalignment angle of the connection portion 102 of each sub-segment gradually changing from the distal end to the proximal end, thereby achieving a transition from extremely soft to slightly stiff within the unit. For example, within the first 3 mm near the head end, the cutting portion 101 is 350° long (connecting portion 102 circumferential angle 10°) with a misalignment angle of 90°; within the next 4 mm, the cutting portion 101 is reduced to 330° (connecting portion 102 circumferential angle 30°), while the misalignment angle remains at 90°; within the final 3 mm, the cutting portion 101 is reduced to 300° (connecting portion 102 circumferential angle 60°), and the misalignment angle is changed to 60°. In this way, the single-connection unit 102 itself provides a stiffness gradient.

[0092] 2. Specific structure of the gradient multi-connection structural unit 2021 The gradient-type multi-connector structural unit 2021 is adjacent to the proximal end of the single-connector structural unit 201 and consists of multiple small segments arranged sequentially from the distal end to the proximal end, denoted as the first segment, the second segment, ..., the Nth segment (N≥1; when N=1, it indicates only one gradient segment, but it can still contain multiple sets of cutting structures 1). Each small segment contains at least three sets of cutting structures 1. Each set of cutting structures 1 has two connecting parts 102 and two cutting parts 101. The cutting structures 1 within all small segments collectively achieve the following gradient objective: along the distal-to-proximal direction, the circumferential lengths of the two cutting parts 101 within the first to Nth segments gradually approach equality from a significant difference, and the circumferential angle between the two connecting parts 102 gradually increases from a small acute angle (ultimately reaching or approaching 180°). Simultaneously, within each small segment, the connecting parts 102 of adjacent sets of cutting structures 1 are successively offset by the same angle in the circumferential direction; the offset angle of this small segment is denoted as β. i (i=1…N). β of different segments i They can be the same or different; however, to ensure continuous rotation, the phase of the last set of connecting parts 102 of the previous segment and the phase of the first set of connecting parts 102 of the next segment should continue the misalignment pattern of the previous segment (i.e., the phase difference is equal to β of the previous segment). i (Or continue to increase according to the set rotation direction).

[0093] There are two modes for implementing gradation: gradation between segments and gradation within segments.

[0094] Gradual transition between segments: Within each segment, the length ratio of the cutting portions 101 and the included angle of the connecting portions 102 in all cutting groups remain constant, but the values ​​differ between different segments. For example, in the first segment, the lengths of the two cutting portions 101 are 10° and 330° (including an included angle of 20° in the connecting portions 102), in the second segment they become 30° and 310° (including an included angle of 30°), in the third segment they become 50° and 280° (including an included angle of 60°), and so on, until the Nth segment, where they become 170° and 170° (including an included angle of 180°). The misalignment angle β within each segment... i They can be set to the same (e.g., 90°). The transition between segments is achieved by changing the geometric parameters, but the direction of the misalignment angle remains unchanged.

[0095] Gradual transition within a small segment: Within each small segment, the length of the cutting portion 101 and the angle between the connecting portion 102 gradually change with the number of groups. For example, a small segment may contain 10 groups of cutting structures 1. Compared to the previous group, the short cutting portion 101 increases by a fixed step length, the long cutting portion 101 decreases by the same step length, and the angle between the connecting portions 102 increases proportionally. This gradual transition within a small segment can achieve a smoother transition, but requires at least 3 groups of cutting structures 1 within the small segment to reflect monotonous change.

[0096] Regardless of the mode used, the total length of the gradient-type multi-connector structural unit 2021 is typically 1–5 mm. In the numerical embodiment, N = 4 segments are defined: the first segment (farthest end) is 0.8 mm long, containing 4 sets of cutting structures 1, with the cutting part 101 having a length of 10° / 330°, the connecting part 102 having an included angle of 20°, and a misalignment angle of 90°; the second segment is 0.8 mm long, containing 4 sets, with the cutting part 101 having a length of 50° / 290°, an included angle of 60°, and a misalignment angle of 90°; the third segment is 0.8 mm long, containing 4 sets, with the cutting part 101 having a length of 90° / 250°, an included angle of 100°, and a misalignment angle of 90°; the fourth segment is 0.8 mm long, containing 4 sets, with the cutting part 101 having a length of 130° / 210°, an included angle of 140°, and a misalignment angle of 90°. After four short sections, extend the initial symmetrical section (cut section 101, 170° / 170° long, with an included angle of 180°) to achieve a perfect connection.

[0097] Furthermore, to achieve smoother contact, the short cut portion 101 can be designed with a slower initial change and a faster later change, or it can be designed in an exponential manner. For example, the short cut portion 101 can change according to a step function: the first two segments remain between 10° and 20°, the third segment rapidly rises to 100°, and the fourth segment rises to 135°. The included angle of the connecting portion 102 changes accordingly. This design allows for the retention of a longer, extremely soft region at the tip.

[0098] 3. Specific structure of the symmetrical multi-connection structural unit 2022 The symmetrical multi-connector structural unit 2022 is also composed of multiple segments (segment 1, segment 2, ..., segment N, N≥1). Each segment contains at least three sets of cutting structures 1. The two connecting parts 102 of each set of cutting structures 1 are symmetrically distributed at 180°, and the circumferential lengths of the two cutting parts 101 are equal (e.g., each cutting part 101 is 170° long, and each connecting part 102 is 10° wide). Within each segment, the corresponding connecting parts 102 of adjacent sets of cutting structures 1 are successively offset by the same angle in the circumferential direction, denoted as γ. j (j=1…N). γ j You can choose the same offset angle as the previous gradient element (e.g., 90°), or you can choose a different angle (e.g., 45°). Different segments of γ j They can be the same, or the first segment can be larger and the second segment smaller, to further increase the near-end stiffness.

[0099] The transition between segments also requires phase continuity: the position of the last connecting part 102 of the previous segment plus the misalignment angle γ of the previous segment. j This should be equal to the position of the first group of connecting parts 102 in the next segment (modulus 360°). If the misalignment angles of the two segments are different, then at the beginning of the next segment, the actual rotation angle of the first group of connecting parts 102 relative to the last group of the previous segment should be equal to the γ of the previous segment. j Then, within the next small segment, it uses its own γ j Continue rotating. This design allows for different helical densities in different sections, as long as they are properly joined at the boundaries.

[0100] In a typical embodiment, the symmetrical multi-connector structural unit 2022 consists of only one small segment (N=1), 10mm in length, containing 40 sets of cutting structures 1 with a misalignment angle of 90°. Its connecting parts 102 appear sequentially at 0°-180°, 90°-270°, 180°-0°, 270°-90°… forming a regular four-step repeating pattern. The bending stiffness of this structure is approximately more than 10 times that of a single connecting part 102 unit, but it has high torsional stiffness, enabling near-1:1 torque transmission.

[0101] In another embodiment, to enhance the torsional sensitivity at the proximal end, the symmetrical shape is divided into two segments: a first segment (3 mm long, offset angle 90°, connecting with the gradient shape); and a second segment (7 mm long, offset angle 30°, making the spiral denser and the torsional response faster). Between the two segments, the last set of connecting parts 102 of the first segment has a phase of θ, so the phase of the first set of connecting parts 102 of the second segment should be θ+90°, and then the second segment rotates in 30° increments.

[0102] To further increase proximal support without excessively increasing stiffness, the width of the connecting portion 102 can be increased (e.g., each connecting portion 102 is 15° wide, and each cut portion 101 is 165° wide), or the misalignment angle can be reduced (e.g., 45°) to make the spiral denser. Alternatively, the width or misalignment angle of the connecting portion 102 within each symmetrical multi-connecting portion 102 unit can be gradually varied to allow the stiffness to continue to increase smoothly.

[0103] By combining the above single connection part, gradient type and symmetrical type, a smooth transition from the farthest end (single rod) to the near end (symmetrical double rod) is achieved, with the stiffness gradually increasing, while maintaining uniform bending performance and good torsional response in all directions.

[0104] 4. Variations in the overall structure In the single-connection structural unit 201, different offset angles (such as 45°) and widths of the connection portion 102 (such as 15°) can also be used. In the gradient type, in addition to changing the length of the cut portion 101, the number of connection portions 102 can be gradually increased (from 2 to 3), or the included angle of the connection portions 102 can be gradually changed.

[0105] The following variations may also be included in the combination method: Multi-segment gradient: Using not just one set of gradient-type multi-connection structural units 2021, but two or three sets, with the length of the cut parts 101 in each set being equal but the rate of change being different, forming a stepped gradient.

[0106] A single connection is directly followed by a symmetrical type: If the length of the gradient type is zero, that is, it jumps abruptly from a single connection to a symmetrical double connection, although stress concentration will occur, it is also an extreme implementation of the present invention if the process allows it and the clinical risk is acceptable.

[0107] Sub-example 2 In this embodiment, the tube structure 2, from distal to proximal, sequentially includes: at least one symmetrical multi-connection structural unit 2022 (distal symmetrical segment), at least one asymmetrical multi-connection structural unit 2023, at least one gradient multi-connection structural unit 2021, and at least one symmetrical multi-connection structural unit 2022 (proximal symmetrical segment). Similar to sub-embodiment one, each unit maintains staggered continuity both internally and between units. This structure reduces bending stiffness through asymmetrical design while retaining the symmetrical segment for distal fixation and the proximal high-support symmetrical segment.

[0108] 1. Distally symmetrical multi-connection structural unit 2022 This unit is located at the farthest end of the tube structure 2. Its function is to fix it to the core wire. It is relatively short, typically 0.5 mm to 2 mm. Its structure is the same as the symmetrical type in sub-example 1: it can be composed of one or more small segments, each segment containing at least three sets of cutting structures 1. Each set of cutting structures 1 has two symmetrically connected parts 102 at 180° and cutting parts 101 of equal length. Adjacent sets of connected parts 102 within the small segment are offset by the same angle, denoted as δ. k (k=1…p). The segments are staggered and continuous. At the same time, the connecting part 102 in the cutting structure 1 of each segment is staggered by the same angle, such as 10°, in the circumferential direction compared to the corresponding connecting part 102 in the corresponding cutting structure 1 of the previous segment.

[0109] 2. Asymmetric multi-connection structural unit 2023 The asymmetric multi-connector structural unit 2023 is immediately adjacent to the proximal side of the distal symmetrical segment. This unit also consists of multiple segments (segment 1, segment 2, ..., segment N, N≥1). Each segment contains at least three sets of cutting structures 1, each set of cutting structures 1 having two connecting parts 102 and two cutting parts 101, with the circumferential lengths of the two cutting parts 101 being unequal. In this unit, the connecting parts 102 of adjacent sets of cutting structures 1 within each segment are sequentially offset circumferentially by a predetermined angle, denoted as ε. i (i=1…N). This offset angle is usually taken as a small value (e.g., 10°~30°) to obtain a denser spiral and make the bending performance more uniform. The preset angle ε for different segments... i They can be the same, or they can increase or decrease from the distal end to the proximal end.

[0110] The unequal lengths of the cut sections 101 can maintain a constant ratio within different segments (e.g., always 260° / 80°), or they can vary segment by segment (e.g., the first segment 260° / 80°, the second segment 240° / 100°, the third segment 220° / 120°, etc., gradually approaching equality). If the asymmetrical segment itself already contains a length gradient, the subsequent gradient-type units can be omitted to directly enter the symmetrical type.

[0111] Inter-segment misalignment continuity requirements: The phase difference between the last set of connecting parts 102 of the distal symmetrical segment and the phase difference between the first set of connecting parts 102 of the asymmetrical segment should be equal to the misalignment angle of the distal symmetrical segment (or consistent with the rotation law); within each sub-segment of the asymmetrical segment, the phase difference between the last set of connecting parts 102 of the preceding sub-segment and the first set of connecting parts 102 of the following sub-segment should be equal to the ε of the preceding sub-segment. i .

[0112] Numerical Example: After the distal symmetrical segment ends, the connecting part 102 is located at a phase of 90°-270° (the last group). The asymmetrical segment uses a single small segment (N=1), with an offset angle ε=10°, and the cutting part 101 is 260° / 80° long (fixed). The connecting part 102 is 180° symmetrical. Therefore, the first group of connecting parts 102 in the asymmetrical segment should be located at (90°+10°)=100°-280°; the second group should be located at 110°-290°; and so on, for a total of 36 groups (total length calculated according to spacing). This spiral continues.

[0113] 3. Gradient-type multi-connection structural unit 2021 The function of the gradient-type multi-connection structural unit 2021 is to transition the unequal-length cut portion 101 of the asymmetrical segment to the equal-length cut portion 101 of the proximal symmetrical segment. Its structural design is similar to the gradient type in sub-example one, and also includes multiple small segments (first segment, ..., Mth segment), with at least three sets of cutting structures 1 within the multiple small segments, and when the number of cutting structures 1 within a small segment is greater than or equal to 2, adjacent sets are misaligned by the same angle (denoted as ζ). j Along the direction from distal to proximal end, the lengths of the two cut portions 101 in the first to Mth segments gradually become equal, and the included angle of the connecting portion 102 gradually increases to 180°.

[0114] Based on this, when connecting segments, the phase of a certain connecting part 102 in the last group of the first segment is a certain value, and the phase of the corresponding connecting part 102 in the first group of the second segment is increased by an offset angle (e.g., 10°) to achieve rotational continuity. That is, the phase of the connecting part 102 in the last group of the previous segment is increased by ζ. j It equals the first phase of the next small segment.

[0115] Numerical Example: The length of the cut section 101 at the end of the asymmetric segment is 260° / 80°, with a misalignment angle of 10°. The gradient unit is divided into 4 segments. The first segment: the length of the cut section 101 is 240° / 100°, with a misalignment angle of 10°; the second segment: 210° / 130°, with a misalignment angle of 10°; the third segment: 180° / 160°, with a misalignment angle of 10°; the fourth segment: 170° / 170°, with a misalignment angle of 10°. Each segment contains 5 sets of cutting structures 1. Thus, the misalignment angle remains at 10° throughout the gradient segment, the helical density remains constant, and only the length of the cut section 101 gradually becomes equal.

[0116] 4. Proximal symmetrical multi-connection structural unit 2022 The proximal symmetrical segment has the same structure as the distal symmetrical segment, but is longer. The arrangement of its internal segments and the selection of offset angles can be based on the proximal support requirements. For example, the proximal symmetrical segment can initially use the same offset angle of 10° as the gradient segment for a short section (e.g., 2 mm), then switch to a smaller offset angle (e.g., 5°) or a larger offset angle (e.g., 30°), achieved by setting multiple segments. The continuity of the offset between segments is always maintained. Ultimately, the entire tube forms a complete gradient from distal to proximal end: "symmetrical (fixed) – asymmetrical (constantly unequal) – gradient (gradually equal) – symmetrical (high support)," with all cutting patterns rotating in the same direction and maintaining phase continuity.

[0117] Sub-example 3 In this embodiment, the tube structure 2 comprises, from distal to proximal end, at least one symmetrical multi-connector structural unit 2022 (distal symmetrical segment), one spiral-cut segment 2024, one single-connector structural unit 201, at least one gradient multi-connector structural unit 2021, and at least one symmetrical multi-connector structural unit 2022 (proximal symmetrical segment). This embodiment is particularly suitable for scenarios requiring an extremely flexible tip.

[0118] 1. Multi-segment design of the 2022 symmetrical multi-connection structural unit. If rigid fixation with the core wire is required, a very short symmetrical multi-connector structural unit 2022 can be set at the farthest end. Its structure is the same as before: it can be composed of one or more small segments, each segment containing at least three sets of cutting structures 1, the connecting parts 102 are 180° symmetrical, the cutting parts 101 are of equal length, the misalignment angle inside the small segment is constant, and the misalignment between segments is continuous. If not required, the spiral cutting segment 2024 starts directly at the farthest end.

[0119] 2. Spiral cutting segment 2024 The spiral cut segment 2024 is a continuous spiral groove without circumferentially separate connecting parts 102, and is spring-shaped overall. This segment does not have the concept of a "group", therefore there is no internal misalignment angle. However, the end of the spiral cut segment 2024 needs to be geometrically matched with the beginning of the next single connecting part structural unit 201.

[0120] 3. Intra-segment misalignment and connection of single-connection structural unit 201 The single connecting section structural unit 201 is located near the end of the spiral cutting section 2024. Its structure is the same as that of the single connecting section 102 unit in sub-example 1: the connecting sections 102 of any two adjacent sets of cutting structures 1 are staggered by the same angle (e.g., 90°) in the circumferential direction. This unit is relatively short, typically 1 to 3 mm, and contains multiple sets of cutting structures 1.

[0121] 4. Evolution of inter-group misalignment and splitting in the 2021 graded multi-connection structural unit The gradient-type multi-connector structural unit 2021 serves as a bridge connecting the single-connector structural unit 201 and the proximal-symmetrical multi-connector structural unit 2022. Its structural design is similar to the gradient type in Sub-Example 1, also including multiple segments (first segment, ..., Kth segment), with at least three sets of cutting structures 1 within each segment. Each set of cutting structures 1 has two connecting parts 102 and two cutting parts 101. When the number of cutting structures 1 within a segment is greater than or equal to two, adjacent sets are offset by the same angle. Along the distal to proximal direction, the lengths of the two cutting parts 101 in the first to Kth segments gradually approach equality, and the included angle of the connecting parts 102 gradually increases to 180°.

[0122] Its core feature is that the two connecting parts 102 of the first group of cutting structures 1 in the first segment are evolved from the connecting parts 102 of the last group of cutting structures 1 of the preceding single connecting part structural unit 201: that is, the original one connecting part 102 is transformed into two independent connecting parts 102, and these two connecting parts 102 are symmetrically distributed about the center line of the original connecting part 102. It should be emphasized that the circumferential width of these two new connecting parts 102 can be set independently, and does not have to be equal to half the width of the original connecting part 102, nor does it have to be equal to each other; they can take any positive value according to mechanical requirements (for example, the original connecting part 102 is 20° wide, and the new connecting parts 102 can each take 8° and 12°, or each take 15° and 15°, or even each take 5° and 5°, etc.). In order to obtain symmetrical mechanical behavior, it is generally preferred that the two connecting parts 102 have equal widths, but the present invention does not exclude the design of unequal widths. From the far end to the near end (that is, as the number of groups increases), the circumferential angle between the two connecting parts 102 in each group of cutting structures 1 gradually increases until it reaches 180° symmetry.

[0123] More specifically, suppose the last set of cut structures 1 at the end of the single-connection structural unit 201 has a connecting part 102 with a circumferential width of W0 and a centerline located at the circumferential phase Φ (i.e., the arc range occupied by the connecting part 102 is [Φ - W0 / 2, Φ + W0 / 2]). In the first set of cut structures 1 of the first segment of the gradient multi-connection structural unit 2021, the single connecting part 102 is replaced by two new connecting parts 102. The circumferential widths of these two new connecting parts 102 are denoted as w1 and w2, respectively (w1>0, w2>0, and w1+w2 may not be equal to W0, i.e., the total solid arc length of the tube at this location can change). These two connecting parts 102 are symmetrical about the original centerline Φ, i.e., their centerlines are located at Φ - θ / 2 and Φ + θ / 2, respectively, where θ is the angle between the centerlines of the two connecting parts 102 (in radians or degrees). The magnitude of θ determines the circumferential distance between the two connecting parts 102 (i.e., the arc length of the small cutting part 101). Let the arc length of the small cutting part 101 be Δ1, then according to geometric relationships: Δ1 = θ - (w1 + w2) / 2. More accurately, the circumferential distance between the two connecting parts 102 (i.e., the arc length of the cutting part 101 between the end of the first connecting part 102 and the front end of the second connecting part 102) is equal to the distance between the center lines of the two connecting parts 102 minus half the sum of the widths of the two connecting parts 102.

[0124] Subsequently, in the subsequent segments of the cut structure 1 of the gradually changing multi-connection structural unit 2021 (second group, third group, ..., Nth group), the width of the two connecting parts 102 can remain constant or gradually change (e.g., gradually widen to increase stiffness). The interval between the two connecting parts 102 (i.e., the arc length of the small cut part 101) gradually increases. Let the arc length of the small cut part 101 in the second group be Δ2, in the third group it be Δ3, ..., Δ n , and satisfy Δ1<Δ2<Δ3<…<Δ n .

[0125] Finally, when the interval Δ n When the lengths of the two cut sections 101 are increased to be equal, a symmetrical double-beam state is achieved. Let the final widths of the two connecting sections 102 be w respectively. 1end and w 2end (Usually a constant value), then of the two cutting portions 101, the smaller cutting portion 101 is Δ n The large cut section 101 is 360° - (w 1end +w 2end ) - Δ n Let the two be equal: Δ n = [360° - (w 1end +w 2end)] / 2. At this time, the two connecting parts 102 are symmetrical about the center (if w 1end = w 2end >, then the centers of the connecting parts 102 are exactly 180° apart). After the transition type ends, it enters the symmetrical multi-connecting part structure unit 2022. All the cutting structures 1 in this unit maintain this symmetrical state and continue to rotate with the same misalignment angle η.

[0126] Taking a specific set of values ​​as an example (for illustrative purposes only, not constituting a limitation): The width W0 of the end connection 102 of a single connection unit 102 is 20°. In the first segment of the gradient type, the widths of the two new connection parts 102 are each set to 10° (equal), and the small cut 101Δ1 = 16°. Therefore, the centers of the two connection parts 102 are located at Φ ± (16+10) / 2 = Φ ±13°. In the second segment, the widths of the two connection parts 102 remain 10° each, the small cut 101Δ2 = 30°, and the centers of the two connection parts 102 are located at Φ ±20° (because (30+10) / 2 = 20°). In the third segment, Δ3 = 44°, the center line of symmetry Φ, and the center is located at Φ ±27°. This continues until Δ... n When (360-20) / 2 = 170°, both cut sections 101 are 170°, achieving symmetry. At this point, the centers of the two connecting sections 102 are exactly 180° apart (because the small gap is 170° + 10° + 10° = 190°, and the large gap is also 170°, so the centers of the two connecting sections 102 are 180° apart). After this, the design enters a symmetrical unit, maintaining the width of each connecting section 102 at 10°, with a 170° interval and a misalignment angle of 90°. In another design, the widths of the two new connecting sections 102 can be unequal, for example, 8° and 12° respectively. In this case, the final symmetrical state must satisfy Δ... n =(360-20) / 2=170° remains unchanged, but at this time, although the total width of the two connecting parts 102 is 20°, their widths are not equal.

[0127] 5. Proximal symmetrical multi-connection structural unit 2022 The proximal symmetrical segment is the same as described above and can be composed of multiple small segments. Each small segment contains at least three sets of cutting structures 1. The connecting part 102 is 180° symmetrical, the cutting parts 101 are of equal length, and the internal misalignment angle is constant (usually consistent with η of the transition type, or adjusted as needed). The phase of the connecting part 102 of the first set of cutting structures 1 should continue the phase of the last set of the transition type, that is, rotated by an angle η in the same direction.

[0128] For example, if the last group of intervals in the transition type has an angle Δ=170° and the axis of symmetry is located at Φ, then the two connecting parts 102 of the first group of connecting parts 102 in the proximal symmetrical segment should be located at Φ+η and Φ+η+180° (because of symmetry). Then, the interior of the proximal symmetrical segment continues to rotate with an offset angle of η. In this way, the entire tube body, from spiral cutting to single connecting part 102, then to the transition type, and then to the symmetrical type, has all cutting patterns with the same rotation direction and continuous phase, achieving a perfect mechanical gradient.

[0129] 6. Complete Numerical Examples The distal symmetrical segment has a length of 0.5 mm, four sets of cutting structures 1, a connecting part 102 with a width of 10°, a cutting part 101 with a length of 170°, and an offset angle of 90°. The last set of connecting parts 102 is located at the 180°-0° phase.

[0130] Spiral cutting section 2024: length 9 mm, pitch 0.5 mm, groove width 0.12 mm.

[0131] Single connecting part structural unit 201: length 2 mm, cutting part 101 length 340°, connecting part 102 width 20°, misalignment angle 90°, the phase of the first group of connecting parts 102 is set to 0°, a total of 8 groups.

[0132] Gradual-type multi-connector structural unit 2021: Length 2.27 mm, assuming an axial length of 0.25 mm per segment (approximately 9.08 segments, taking 9 segments). Each connecting part 102 is 10° wide, with an initial interval of 16° and a final interval of 170°, and a step size of (170-16) / (9-1)=20°. The first set of symmetry axes is located at the phase of the last set of connecting parts 102 in a single connecting part (after the single connecting part structural unit 201 is misaligned by 8 sets, the phase is 0°+7×90°=630°≡270°), so the first segment of the symmetry axis is located at 270°, and the centers of the two connecting parts 102 are located at 270°±(16°+10°) / 2=270°±13°, i.e., 257° and 283°. The 9th segment has an interval of 16 + 8 × 20 = 176°, which is close to 170°. At this point, the lengths of the two cut parts 101 are (360 - 20 - 176) = 164° and 176° respectively, which are basically symmetrical.

[0133] Proximal symmetrical multi-connector structural unit 2022: length 10 mm, each connector 102 is 10° wide, the cut section 101 is 170° long, and the misalignment angle is 90°. The first set of symmetry axes is located at the last set of symmetry axes of the transition type + 90° = 270° + 90° = 360° ≡ 0°, therefore the connector 102 is located between 0° and 180°. It then rotates in 90° increments.

[0134] Through the detailed design described above, this sub-implementation achieves a smooth transition from a continuous spiral (extremely flexible) through a single connecting part and a split transition to a symmetrical double beam (high support), and the misalignment relationship between all the cut parts 101 is continuous and unified.

[0135] As a preferred embodiment of the third embodiment, based on the tube structure 2 of all the above sub-embodiments, a honeycomb-shaped perforated pattern 203 is further provided on the proximal tube wall. This honeycomb-shaped perforated pattern 203 is composed of multiple interconnected honeycomb units. The honeycomb units can be selected from at least one of hexagonal, quadrilateral, triangular, rectangular, circular, concave hexagonal, double V-shaped, chiral structure, or star-shaped.

[0136] In a preferred embodiment, the honeycomb cells are regular hexagons, arranged in a periodic array on the outer surface near the end of the tube or along its entire circumference. The side length and wall thickness of the hexagons can be adjusted according to the required mechanical properties. Compared with traditional symmetrical double-beam hyaluronic acid tubes, the honeycomb structure has the following advantages: when the tube is subjected to bending, tension, or compression, the wall panels of each honeycomb cell undergo elastic deformation, distributing stress to multiple surrounding cells, avoiding stress concentration, and thus significantly improving fracture resistance. Furthermore, the mechanical behavior of the honeycomb structure can be categorized into elastic and plastic responses, static / quasi-static and dynamic (low, medium, high speed) responses, in-plane (longitudinal and transverse) and out-of-plane responses, etc. Unlike elastic responses, the mechanical behavior of the honeycomb structure in the plastic range is more complex, exhibiting more pronounced nonlinear characteristics. Under compression, the stress exhibits three distinct stages: an elastic stage, a plateau stage, and a densification stage. Moreover, the energy absorption mechanism of the honeycomb differs under different loading directions. Under in-plane loads, the honeycomb structure primarily absorbs energy through bending deformation of the unit walls and plastic hinges at the unit wall joints. Under out-of-plane loads, it absorbs energy through buckling of the unit cell walls and in-plane deformation. The compressive stress and energy absorption level of the honeycomb structure are typically higher in the out-of-plane direction. This multi-mode energy dissipation mechanism enables the subsurface tube to exhibit higher strength and toughness when subjected to complex loads.

[0137] Another advantage of the honeycomb perforated pattern 203 is improved proximal support. In interventional procedures, when other instruments (such as microcatheters) are advanced along the guidewire, insufficient proximal support can lead to a "windowsill effect"—the instrument tip gets stuck at the step where the guidewire stiffness changes, or pushes the guidewire forward and prolapses. The honeycomb structure, with its excellent out-of-plane stiffness, provides stable radial support, effectively mitigating the windowsill effect. This allows instruments to pass more smoothly through tortuous areas such as the cavernous sinus segment and the ophthalmic artery, shortening the procedure time.

[0138] In practice, a honeycomb pattern can be laser-cut into the near-end wall of a nickel-titanium tube. The dimensions of the honeycomb unit are, for example, a hexagon with a side-to-side distance of 0.5 mm and a wall thickness of 0.05 mm. Multiple units are interconnected, covering a section of the tube's circumference and axial length (e.g., 20 mm). The overall flexibility or stiffness can be adjusted by changing the area of ​​the hollowed-out portions or the area of ​​the connecting portions; a larger hollowed-out area results in higher flexibility and lower stiffness, and vice versa. To ensure a smooth transition with the distal cut pattern, a short, unpatterned transition zone can be created between the honeycomb area and the distal cut area.

[0139] Besides hexagons, quadrilaterals (such as square or rhomboid grids), triangles (such as triangular grids), circles (circular hole arrays), concave hexagons (negative Poisson's ratio structures), double V-shapes (arrowhead shapes), chiral structures (rotationally symmetric), or star shapes (concave star shapes) can also be used. These structures all possess excellent fracture resistance and energy absorption characteristics. For example, the concave hexagonal structure exhibits a negative Poisson's ratio effect, contracting laterally under tension to better conform to the core wire; chiral structures possess a unique torsional-stretching coupling effect. Designers can choose the appropriate geometry based on specific requirements.

[0140] It should be noted that the honeycomb-shaped hollow pattern 203 can be applied to any combination of specific sub-example 1, sub-example 2, and sub-example 3, or it can be independently combined with other features in example 3.

[0141] Example 4 This embodiment provides a microguidewire, including any of the tube structures 2 described in Embodiment 3. Furthermore, the microguidewire also includes a core wire (typically stainless steel or nickel-titanium alloy wire), with the tube structure 2 sleeved and fixedly connected to the distal end of the core wire. The connection method can be welding (e.g., laser spot welding), bonding (medical epoxy resin), or mechanical crimping. The proximal end of the core wire is typically a thicker stainless steel wire, providing pushing force; the distal end gradually tapers to achieve flexibility when used with the hypotube.

[0142] In one specific implementation, the fabrication steps of the microguidewire are as follows: Prepare a nickel-titanium alloy or stainless steel core wire with a diameter of 0.3mm and a length of 2000mm. The distal 150mm of the core wire is tapered and the distal end has a diameter of 0.05mm.

[0143] Prepare a nickel-titanium alloy hypo tube blank with an outer diameter of 0.4 mm, an inner diameter of 0.35 mm, and a length of 300 mm.

[0144] Using a femtosecond laser cutting machine, corresponding grooves and honeycomb near-end patterns are processed at the far end of the sodium hypotube according to the cutting pattern of any one of the embodiments described in Embodiment 3 (e.g., Sub-Embodiment 1).

[0145] The cut hyaluronic acid tube can be selectively heat-treated for shaping (500℃, 10 minutes, water quenching).

[0146] When stainless steel core wire is selected, the platinum tungsten spring and stainless steel core wire must be connected together by welding or bonding.

[0147] The sodium hypotube is fitted onto the core wire or core wire spring assembly, with the distal end of the sodium hypotube extending approximately 0.2 mm beyond the end of the core wire. The distal end of the sodium hypotube is then fixed to the core wire by welding or bonding.

[0148] The near end of the hyaluronic acid tube is further reinforced by welding or bonding to the core wire.

[0149] The entire microwire is coated with a hydrophilic coating (e.g., polyvinylpyrrolidone) to reduce friction.

[0150] The microguidewire obtained through the above process was tested in an in vitro simulated vascular tortuosity model, and the tip stiffness was reduced by about 50% compared with the traditional symmetrical double-beam hypotube microguidewire, which can achieve 1:1 torsion control.

[0151] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention, and do not imply or require that the device or element referred to must have a specific orientation or construction method, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish the objects of description and should not be construed as limiting importance or order, and the features defined by such terms may explicitly or implicitly include one or more of those features. Unless otherwise stated, "a plurality of" in the description of this invention refers to two or more.

[0152] The terms "installation," "connection," and "joining" should be interpreted broadly, unless otherwise explicitly defined, to include, but are not limited to, fixed connections, detachable connections, or integrally formed connections; mechanical or electrical connections; direct connections or indirect connections via an intermediate medium; and internal communication between two components. Those skilled in the art can understand their meaning based on the specific technical solution. The fixed connections involved in this invention, unless otherwise stated, include both detachable fixed connections (such as bolt and screw connections) and non-detachable fixed connections (such as riveting and welding), and may also include integral structures achieved through an integral forming process (such as casting) (except where integral forming is clearly not feasible).

[0153] Unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes cover states or shapes that are similar to, close to, or nearly similar to those states or shapes.

[0154] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process.

[0155] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only used to complement the content disclosed in the specification, so as to enable those skilled in the art to understand and read them, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0156] In the embodiments of this application, the same reference numerals are used to denote the same component or part.

[0157] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0158] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A tubular structural unit, characterized in that: It includes at least two sets of cutting structures, each set of cutting structures including a cutting part and a connecting part formed along the circumference of the tube body; at least two sets of cutting structures are arranged side by side in sequence along the axial direction of the tube body structural unit, and the connecting parts of adjacent sets of cutting structures are staggered in the circumferential direction in a clockwise or counterclockwise direction.

2. A tubular structural unit, characterized in that: It includes at least three sets of cutting structures, each set of cutting structures including at least two cutting portions and at least two connecting portions formed along the circumference of the tube body; the at least three sets of cutting structures are arranged side by side in sequence along the axial direction of the tube body structural unit, and the connecting portion of any set of cutting structures is staggered in the circumferential direction with the connecting portions of the preceding and following sets in a clockwise or counterclockwise direction.

3. The tubular structural unit according to claim 2, characterized in that: In each group of at least two connecting parts of the cutting structure, the cutting part between two adjacent connecting parts is set as the reference segment A; in at least three groups of the cutting structures arranged in parallel along the axial direction of the tube structure unit, the length of the reference segment A gradually increases, gradually decreases, or remains unchanged.

4. A tubular structure for a microguidewire, characterized in that: It includes at least one single-connection tube structure unit as described in claim 1 and / or at least one multi-connection tube structure unit as described in claim 2 or 3; wherein, the tube structure unit as described in claim 1 is called a single-connection structure unit, and the tube structure unit as described in claim 2 or 3 is called a multi-connection structure unit.

5. The tubular structure for microguidewires according to claim 4, characterized in that: When the number of the tube structure units is N, and N is an integer greater than or equal to two, the N tube structure units are connected sequentially along the axial direction of the tube structure, and the flexibility of the N tube structure units gradually decreases from the far end to the near end of the tube structure.

6. The tubular structure for microguidewires according to claim 5, characterized in that: The tubular structure includes a single-connector structural unit, at least one gradient-type multi-connector structural unit, and at least one symmetrical multi-connector structural unit arranged sequentially from its distal end to its proximal end; wherein... In the single connection structural unit, the connection parts of any two adjacent sets of cutting structures are staggered by the same angle in the circumferential direction. At least one of the aforementioned gradient multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts. The circumferential lengths of the cutting parts in the first to Nth segments of the cutting structure gradually approach equal lengths, the circumferential angle between the two connecting parts gradually increases, and the connecting parts in the first to Nth segments of the cutting structure are successively offset by the same angle in the circumferential direction. At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first to the Nth segments are staggered by the same angle in the circumferential direction.

7. The tubular structure for microguidewires according to claim 4, characterized in that: The tubular structure includes at least one symmetrical multi-connection structural unit, at least one asymmetrical multi-connection structural unit, at least one gradient multi-connection structural unit, and at least one symmetrical multi-connection structural unit arranged sequentially from its distal end to its proximal end; wherein... At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first segment to the Nth segment are staggered by the same angle in the circumferential direction. At least one section of the asymmetric multi-connection structure unit includes a first section, a second section, ..., an Nth section arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts, and the circumferential lengths of the two cutting parts are not equal. The connecting parts in the cutting structures of the first to the Nth sections are staggered by a preset angle in the circumferential direction. At least one of the aforementioned gradient multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts and two cutting parts. The circumferential lengths of the cutting parts in the first to Nth segments of the cutting structure gradually approach equal lengths, the circumferential angle between the two connecting parts gradually increases, and the connecting parts in the first to Nth segments of the cutting structure are successively offset by the same angle in the circumferential direction.

8. The tubular structure for microguidewires according to claim 4, characterized in that: The tubular structure includes at least one symmetrical multi-connector structural unit, one spirally cut segment, one single-connector structural unit, one transitional multi-connector structural unit, and at least one symmetrical multi-connector structural unit arranged sequentially from its distal end to its proximal end; wherein... At least one of the symmetrical multi-connection structural units includes a first segment, a second segment, ..., an Nth segment arranged sequentially from the distal end to the proximal end of the tube structure. Each set of cutting structures includes two connecting parts symmetrically distributed at 180° and two cutting parts with equal circumferential lengths. The corresponding connecting parts in the cutting structures of the first segment to the Nth segment are staggered by the same angle in the circumferential direction. The spiral cutting section is a continuous spiral groove, which makes the tube section form a spring-like structure; Each set of cutting structures in the transitional multi-connection structural unit includes two connecting parts and two cutting parts; wherein, the two connecting parts in each set of cutting structures are symmetrically distributed around one of the connecting parts in the last set of cutting structures in the previous single-connection structural unit, and the circumferential angle between the two connecting parts in each set of cutting structures gradually increases from the far end to the near end until they are symmetrically distributed at 180°.

9. The tubular structure for microguidewires according to any one of claims 4-8, characterized in that: The proximal wall of the tube structure is also provided with a honeycomb-shaped perforated pattern, which is composed of multiple interconnected honeycomb units; the honeycomb unit is selected from at least one of hexagonal, quadrilateral, triangular, rectangular, circular, concave hexagonal, double V-shaped, chiral structure or star-shaped.

10. A microguidewire, characterized in that: Includes the tubular structure as described in any one of claims 4-9.

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