Serrated balloon

Abstract

The present invention belongs to the field of medical device technology, and discloses a serrated balloon, comprising a balloon, and a strip in the shape of a strip deployed on the outer surface of the balloon; the strip comprises a plurality of serrated units, and a plurality of connecting units connected between two serrated units; the serrated units comprise a wedge-shaped portion; the same connecting unit connects two serrated units to form a serrated unit group, and when the wedge-shaped portion on the strip is in an extruded state, at least some serrated unit groups have a structural rigidity different from that of other serrated units; and / or, at least some serrated unit groups have a structural rigidity different from that of other serrated unit groups. In actual use, the balloon in this application can adapt to discretely distributed plaque environments and severely tortuous blood vessel environments, guiding calcified plaques to rupture along the axial direction of the blood vessel; compared to existing modified balloons, it can simultaneously have high permeability and efficient scoring / cutting performance.

Description

Technical Field

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

[0002] Atherosclerosis (AS) is a major cause of coronary heart disease, cerebral infarction, and peripheral vascular disease. Balloon angioplasty is one of the most commonly used clinical treatments for atherosclerosis. A high-pressure balloon is introduced into the narrowed vascular lesion. The balloon's expansion exerts force on the plaque, which in turn stretches and compresses it, causing it to rupture or otherwise break. For lesions with higher stenosis, conventional balloon angioplasty often requires higher pressures due to the thicker and unevenly distributed plaques. Furthermore, when using conventional balloons for expansion, plaque rupture is relatively random, resulting in uncontrolled damage to the vessel and easily leading to restenosis.

[0003] The residual stenosis rate and long-term patency rate after conventional balloon angioplasty are poor. Residual stenosis refers to the failure of a vessel to fully dilate or undergo elastic recoil after balloon angioplasty (PTA), which may lead to restenosis.

[0004] Modified balloons generally refer to serrated balloons, spinous process balloons, and double-guidewire balloons. Their principles are similar (serrated balloons are microsurgical strips, spinous process balloons are nylon spinous process ridges, and double-guidewire balloons are metal wires). Compared with ordinary balloons, modified balloons have the following advantages: (1) For high-resistance lesions such as mild to moderate calcification, modified balloons can cause endothelial calcification to break, thereby improving the balloon expansion effect. (2) The tearing caused by the disordered expansion of ordinary balloons can easily lead to dissection hematoma and increase the risk of acute vascular occlusion. After the modified balloon is expanded, the plaque tear is guided to occur mostly in the long axis direction of the blood vessel, thereby reducing the formation of flow-limiting dissection. (3) The modified balloon is easy to fix on the plaque surface, avoiding balloon slippage, reducing the "watermelon seed effect" (especially in stent restenosis lesions), and thus reducing accidental damage to normal segments. In terms of lesion cutting, the serrated balloon outperforms the spinous process balloon and the double-guidewire balloon. In terms of lesion passability, the opposite is true: the serrated balloon outperforms the spinous process balloon and the double-guidewire balloon. Therefore, existing modified balloons are not suitable for: ① severe vessel tortuosity; ② lesion angles greater than 45°; ③ direct pretreatment of severely calcified lesions.

[0005] When used clinically, existing serrated balloons have the technical defect of being unable to achieve both high permeability and efficient scoring. Furthermore, when faced with severe blood vessel tortuosity, the local scoring effect fails, making it impossible to effectively guide the calcified plaque to crack along the axis of the blood vessel. When faced with a discretely distributed plaque environment, the local scoring effect fails, making it impossible to effectively guide the calcified plaque to crack along the axis of the blood vessel. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a serrated balloon to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention is specifically implemented by the following technical solutions.

[0008] A first aspect of the present invention provides a serrated balloon, comprising a balloon and a strip-shaped strip deployed on the outer surface of the balloon, wherein the strip comprises a plurality of serrated units, and the serrated unit comprises a wedge-shaped portion; the same connecting unit connects two serrated units to form a serrated unit group, and when the wedge-shaped portion on the strip is in an extruded state, at least some of the serrated unit groups have a structural rigidity different from that of other serrated units; and / or, at least some of the serrated unit groups have a structural rigidity different from that of other serrated unit groups.

[0009] The second aspect of the present invention provides a serrated balloon, comprising a balloon and a strip-shaped strip deployed on the outer surface of the balloon; the strip comprises a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated unit comprises a wedge-shaped portion; the same connecting unit connects two serrated units to form a serrated unit group, and at least some serrated unit groups have different structural rigidity from other serrated unit groups.

[0010] The third aspect of the present invention provides a serrated balloon, comprising a balloon and a strip-shaped strip deployed on the outer surface of the balloon; the strip comprises a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated units comprise a wedge-shaped portion; at least some of the connecting units are non-closed arches, and some of the connecting units are non-arched.

[0011] The fourth aspect of the present invention provides another serrated balloon, comprising a balloon and a strip-shaped strip deployed on the outer surface of the balloon; the strip comprises a plurality of serrated units, each of which comprises a wedge-shaped portion; the connecting unit is in the shape of a non-closed arch; and there are at least two connecting units whose arch opening directions are opposite to each other.

[0012] In one embodiment of the present invention, the strip is used to form a hole array in a desired blood vessel lumen through a plurality of wedge-shaped portions, so as to guide the tearing of the hardened plaque along the long axis of the blood vessel.

[0013] In one embodiment of the present invention, the serrated balloon is in an inflated state; in the inflated state, the serrated balloon is located within a vascular cavity. Furthermore, some serrated units that fail to contact the sclerotic plaque as desired can interact with their connected units to contact the sclerotic plaque; and / or some serrated units that fail to contact the sclerotic plaque as desired can indirectly contact the sclerotic plaque through the interaction of several connected units on the strip.

[0014] In one embodiment of the present invention, the serrated balloon further comprises a catheter assembly having a liquid guide channel function and a manipulation function.

[0015] In one embodiment of the invention, at least some of the connecting units are lateral compliant.

[0016] In one embodiment of the present invention, the serration unit includes a base portion supporting the wedge portion; the base portion has a base fixing surface facing the outer surface of the balloon, and the wedge portion is arranged on the base portion away from the base fixing surface.

[0017] In one embodiment of the present invention, the wedge-shaped portion is used to form micro-holes with a pore diameter of less than 1 mm and a pore depth of less than 1 mm in a desired blood vessel lumen.

[0018] In one embodiment of the present invention, the strip is made of metal material.

[0019] In one embodiment of the present invention, the serrated balloon further comprises a strip base disposed on the outer surface of the balloon, the strip base being used to reduce the concentration of force from the strip acting perpendicularly to the outer surface of the balloon and / or to resist lateral tipping of the strip.

[0020] In one embodiment of the present invention, the strip base is a high molecular polymer.

[0021] In one embodiment of the present invention, only one wedge-shaped portion is disposed on the base portion of some sawtooth units.

[0022] In one embodiment of the present invention, gaps are maintained between some of the base parts by arched connecting units.

[0023] In one embodiment of the present invention, some of the wedge-shaped portions have a height that is less than 0.7 mm and protrudes outward in the radial direction of the balloon relative to the arched connecting unit.

[0024] In one embodiment of the present invention, a mortise and tenon structure is formed between the two base portions of the strip, and a part of the strip base and the mortise and tenon structure are formed to enhance the peeling strength and / or interface stress diffusion between the strip and the strip base.

[0025] In one embodiment of the present invention, the arched connecting unit includes an arc-shaped portion, and the radian of the arc-shaped portion is less than 1 πrad.

[0026] In one embodiment of the present invention, the strip is not fixed to the working area of ​​the balloon.

[0027] In one embodiment of the present invention, the balloon is a compliant balloon or a semi-compliant balloon.

[0028] In one embodiment of the present invention, both ends of the strip are fixed on the serrated balloon away from the working area of ​​the balloon.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The serrated balloon provided in the present invention;

[0031] 1) By deploying strips on traditional balloons, the strips have serrated units (serrated protrusions) on a wedge-shaped portion, which allows for a more concentrated force than on ordinary balloons (when an object has discontinuous protrusions on its surface, it is easier to concentrate force than on a smooth object, resulting in a controllable and predictable cracking effect), thereby reducing expansion pressure and minimizing damage to blood vessels. This improves the residual stenosis rate and poor long-term patency rates after traditional balloon angioplasty, and increases postoperative lumen gain and blood flow.

[0032] 2) Through further design of the strip structure and function, the strip exhibits (distributes) different structural rigidities (structural rigidity areas) along the longitudinal direction (length direction), so as to adapt to the discretely distributed plaque environment and the severely tortuous vascular environment, and guide the calcified plaque to crack along the axial direction of the blood vessel; compared with existing modified balloons, it can have both high permeability and efficient scoring / cutting performance.

[0033] 3) By deploying connecting units with different shapes in the strips, the serrated balloon provided in the present invention can obtain better comprehensive performance including bending, sheathing and fatigue resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Provides a physical picture of a serrated balloon according to one embodiment of the present invention;

[0035] Figure 2 A schematic diagram of the overall structure of a serrated balloon according to one embodiment of the present invention is provided;

[0036] Figure 3 for Figure 2 Middle AA section partial enlarged schematic diagram;

[0037] Figure 4 for Figure 3 A local enlarged schematic diagram of point N in the middle;

[0038] Figure 5 for Figure 3 A partial enlarged schematic diagram of the M in the middle;

[0039] Figure 6 for Figure 2 Schematic diagram of the balloon with leaflets in a semi-folded state;

[0040] Figure 7 A partial schematic diagram of a strip structure with distribution of sawtooth unit groups of different structural rigidity in some embodiments;

[0041] Figure 8 For Figure 7 A partial schematic diagram of a strip structure with a different structural rigidity distribution;

[0042] Figure 9 A partial schematic diagram of a strip structure with different morphological connection units;

[0043] Figure 10 for Figure 9 Physical picture of the strip;

[0044] Figure 11 For Figure 9 A partial schematic diagram of a strip structure with a different structural rigidity distribution;

[0045] Figure 12 for Figure 11 Schematic diagram of the three-dimensional structure;

[0046] Figure 13 To have Figure 9 A partial schematic diagram of the strip structure of the suspended connection unit 423 with different connection positions of the middle connection unit 428;

[0047] Figure 14 For Figure 7 Partial schematic diagram of strip structures with different structural rigidity distributions and different shapes of connecting units;

[0048] Figure 15 For Figure 7 A partial schematic diagram of another strip structure with different structural rigidity distribution;

[0049] Figure 16 for Figure 15 A front view of the middle connecting unit 426;

[0050] Figure 17 It is a partial schematic diagram of a strip structure with sawtooth units of different shapes;

[0051] Figure 18 A partial schematic diagram of a strip structure having a wedge and a cone;

[0052] Figure 19 A partial schematic diagram of a strip structure having a wedge and a cone;

[0053] Figure 20 A schematic diagram of a strip structure having a single form and non-suspended connection units;

[0054] Figure 21 A schematic diagram of a distal end section of a strip having different forms of connecting units at both ends of the strip;

[0055] Figure 22 for Figure 21 Schematic diagram of an oblique upward view;

[0056] Figure 23 for Figure 20 Fatigue resistance test result diagram of the embodiment;

[0057] Figure 24 for Figure 21 Fatigue resistance test result diagram of the embodiment;

[0058] Figure 25 Schematic diagram of a sawtooth unit structure with a wedge in the strip structure of the present invention;

[0059] Figure 26 Schematic diagram of a sawtooth unit group with an arched opening toward a wedge-shaped portion in the strip of the present invention;

[0060] Figure 27 Schematic diagram of a sawtooth unit group with an arched opening toward the base portion in the strip of the present invention;

[0061] Figure 28 Schematic diagram of different distributions of arc centers of arched connecting units in the strip of the present invention;

[0062] Figure 29 It is a simplified linear diagram of the bow-shaped connection unit;

[0063] Figure 30 Schematic diagram of disturbance calculation of simply supported beam in the prior art;

[0064] Figure 31 is the function graph;

[0065] Figure 32 A simplified schematic diagram of disturbance calculation of the arched connection unit of the present invention;

[0066] Figure 33 Schematic diagram of the effect of serrated strips used in blood vessels;

[0067] Figure 34 Schematic diagram of some arched connection unit groups with the same compliance direction being deployed on opposite sides of a balloon in some embodiments;

[0068] Figure 35 Schematic diagram of the joint surface of the base portion of the sawtooth unit in some embodiments. DETAILED DESCRIPTION

[0069] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0070] See also Figures 1 to 35. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0071] The term "nominal pressure" in this specification refers to the pressure required to obtain the inflated balloon diameter indicated on the label. The nominal pressure is defined as the pressure at which 99% of the balloons will not rupture.

[0072] As used herein, the term "trackability" refers to the ability of a medical device (or interventional device, including serrated balloon catheters) to extend and advance smoothly and unimpeded along the intended path as it advances through a blood vessel or other internal conduit (i.e., its ability to follow the vascular anatomy). Medical devices must maintain sufficient rigidity to provide thrust while possessing good flexibility to adapt to the complex anatomy of the body. This balance ensures that the device can advance steadily in straight sections while also nimbly maneuvering around turns and branches.

[0073] The term "compliance" in this specification refers to the flexibility and adaptability of a medical device (or interventional device, including serrated balloon catheters) when bending or navigating complex anatomical structures (i.e., the device's ability to follow the natural curvature of an angled or tortuous vessel when deployed within it). The passability of a serrated balloon catheter is positively correlated with its trackability and compliance.

[0074] The term "lateral compliance" in this specification refers to the fact that, compared to straight rods, curved rods are more susceptible to further bending deformation along the direction of their curvature when subjected to lateral forces. This property is therefore defined as lateral compliance. Ideally, a straight rod, assuming uniform material, consistent cross-section, and no prestressing, has relatively uniform bending stiffness in all directions. However, the bending stiffness of a curved rod varies along its length. In particular, when the line of action of the bending moment does not coincide with the central axis of the rod, local areas may reach the material's yield strength first, causing significant deformation. When a curved rod is subjected to lateral forces, bending deformation is more likely to occur along the curvature than in the opposite direction of the curvature. This is because when the lateral force is in the same direction as the rod's own curvature, it is more likely to cause the rod to further deform along its original curve.

[0075] The term "compliant state" in this specification means that when a force is applied along the bending direction of the arc rod, the arc rod is in a unilaterally deformable state, which is defined as the compliant state.

[0076] The term "resistance state" as used herein refers to a state in which the curved rod resists deformation on one side, as opposed to the compliance state, when a force is applied in the direction opposite to the bending direction of the curved rod. This state is defined as resistance. The lateral force acts on the concave side of the curved rod (i.e., in the direction opposite to the bending direction), opposing the rod's inherent bending shape. In this situation, the rod's structure can, to a certain extent, resist the external force attempting to "correct" its original bending shape. Therefore, its ability to resist bending deformation is greater when applied in the direction opposite to the bending direction than when applied in the direction of the bending direction.

[0077] The term "rigidity characteristics" in this specification refers to the ability of a material or structure to resist deformation when subjected to external forces. Rigidity characteristics mainly involve: elastic modulus (E), which is a basic indicator for measuring the rigidity of a material and is defined as the ratio of stress to strain within the elastic range; the larger the elastic modulus, the stronger the material's ability to resist elastic deformation, that is, the better the rigidity. Shear modulus (G): Similar to the elastic modulus, but specifically refers to the ability of a material to resist shape changes under shear force, and is also an important parameter for evaluating structural rigidity. Bending stiffness (EI): For rod or beam structures, its bending stiffness is a measure of the structure's ability to resist bending deformation. The calculation formula is the elastic modulus E multiplied by the section moment of inertia I; the section moment of inertia reflects the influence of the cross-sectional shape on the bending resistance, so even if the material is the same, the rigidity of components with different cross-sectional shapes will be different. Torsional stiffness (GJ): Similar to bending stiffness, torsional stiffness measures the structure's ability to resist torsional deformation and is mainly determined by the material's shear modulus G and section polar moment of inertia J. Structural factors: The rigidity of an actual structure depends not only on the material itself, but is also closely related to factors such as the structure's geometry, size, and connection method.

[0078] The term "structural rigidity" in this specification refers to a structure's ability to resist deformation when subjected to external forces. The higher the rigidity of a structure, the smaller its deformation; the lower its rigidity, the larger its deformation. Factors influencing this rigidity include material properties (elastic modulus / Poisson's ratio), geometry (cross-sectional shape / dimensions / length), and boundary conditions (support method / load distribution).

[0079] The term "arch" in this specification refers to a structural form, usually composed of curves or curved surfaces, supported on a base at both ends, and can be in various forms such as arc, semicircle, ellipse, parabola, etc. The term "arc" in this specification refers to a part of a circle, that is, a curve on the circumference, with a fixed curvature. The term "segment" in this specification refers to a part of a circle, consisting of a chord and a corresponding arc. The arch can be divided into a major arc arch (an arch equal to or larger than a semicircle) and an inferior arc arch (an arch smaller than a semicircle).

[0080] The term "deflection" in this specification refers to the degree of bending deformation of a component (such as a beam, column, or plate) when subjected to an external force. It is measured as the distance from the center of each cross-section of the component after bending to the original axis. Angle is defined as the angle between the tangent to the chord at a point and the horizontal plane.

[0081] The term "wedge-shaped portion" in the present invention refers to at least a wedge tip with a cutting function or an end with a force-gathering function; it may also include a bottom that is widened relative to the wedge tip, and an inclined wedge-shaped side surface between the wedge tip and the bottom.

[0082] The test and evaluation method for the term "bendability" in the present invention is: the three-point bending performance test method for balloon catheters proposed in the YY / T 0858-2011 standard.

[0083] The test and evaluation method for the term "fatigue resistance" in the present invention is: "Simulate the repeated inflation and deflation process of the balloon in clinical use, record the fatigue life of the balloon, and the balloon should be able to withstand the specified number of cycles without rupture or performance degradation" proposed in the ISO 10555-4:2013 standard.

[0084] To address the technical shortcomings of existing modified balloons, which lack both high permeability and efficient cutting performance, the applicant, through extensive and in-depth research combined with finite element simulation analysis and experimental analysis, has proposed a core concept: designing teeth (also known as serrations) connected by connecting units to exhibit the following characteristics: 1) In the folded state, when the balloon is curved in an arc or S-shape, at least some teeth tend to conform to the balloon's curvature compared to other teeth; and / or, at least some teeth tend to resist the balloon's curvature. 2) In the inflated state, when the teeth are squeezed, at least some teeth tend to conform to the squeezing compared to other teeth; and / or, at least some teeth tend to resist the squeezing. 3) The strip exhibits (distributes) different structural rigidities (structural rigidity areas) along the longitudinal direction (length direction), so as to adapt to the discretely distributed plaque environment and the severely tortuous vascular environment and guide the calcified plaque to crack along the axial direction of the blood vessel; compared with existing modified balloons, it can simultaneously have high permeability and efficient scoring / cutting performance; improve the shortcomings of existing modified balloons in dealing with ① severe vascular tortuosity, ② lesion angle >45°, and ③ direct pretreatment of severely calcified lesions.

[0085] This structural design significantly improves the serrated balloon's flexibility and cornering ability (trackability) without sacrificing the strip's focused cutting action. Compared to conventional PTA, it achieves the combined effects of significantly increasing blood flow, minimizing vascular damage, enabling low-pressure angioplasty, and treating a variety of lesions (including arterial calcification). The anisotropic connecting units create a longitudinally distributed softness and hardness profile in the strip, maintaining superior stiffness during plaque cutting. This improved compliance does not significantly impair the tool's cutting performance, thus ensuring full functionality. Based on this core concept, the applicant provides the following specific embodiments.

[0086] like Figures 1 to 6As shown, the serrated balloon provided by the present invention comprises a balloon 200 supported on the distal end of a catheter assembly 100 and a strip-shaped band 400 disposed on the outer surface of balloon 200. The catheter assembly 100 typically comprises a push rod (catheter tube) capable of transmitting force to the balloon tip, enabling it to reach the lesion. The catheter assembly 100 functions as a fluid conduit and manipulator, and can employ either a rapid exchange (Rx) or over-the-wire (OTW) design as known in the art. Typically, the catheter 100 has one or more lumens within it, some of which connect the balloon cavity to the filling port 110. The outer diameter, hardness, and length of the balloon 200 tip can affect its ability to pass through the lesion. Currently, a conical design is often used in clinical practice, and it is attached to the catheter assembly 100 using laser welding technology. The outer surface of the balloon 200 can be generally divided into a balloon working area 260 that interacts with the blood vessel wall and a balloon non-working area 270 that does not interact with the blood vessel wall; the strip 400 is generally deployed in the balloon working area 260; the two ends 490 of the strip 400 (such as Figures 20-23 The strips between the two portions can be fixedly connected to the balloon working area 260 in a manner such as Figures 3 to 5 As shown, the entire strip 400 is bonded and fixed to the balloon working area 260 with an adhesive (polymer base layer 300) on its base surface facing the outer surface of the balloon. Alternatively, the strip 400 may be non-fixed to the balloon working area 260. Non-fixed methods include extending the ends 490 of the strip 400 beyond the balloon working area 260 and fixing them to the area near the balloon non-working area 270 by means of a cluster ring or direct bonding. The balloon 200 can be inflated and expanded by the catheter assembly 100 (e.g., Figure 1 As shown), it is also possible to release pressure back through the catheter assembly 100 (as shown Figure 6 As shown in the figure). Figures 4 to 25 As shown, the strip 400 includes several sawtooth units ( Figure 17 401 and 402, Figure 14 403, Figure 21 404, Figure 20 405), and a plurality of connection units connected between two sawtooth units ( Figure 7 420 Figure 19 421 Figure 18 422 Figure 13 423 Figure 14 424 and 425, Figure 15 426 Figure 11427, 428 and 429). The serrated balloon further includes a strip base (polymer base layer 300) disposed on the outer surface of the balloon. The strip base is used to reduce the concentration of force from the strip acting perpendicularly on the outer surface of the balloon and / or to resist lateral tipping of the strip. The strip base is made of a high molecular polymer.

[0087] According to one of the core concepts of the present invention, the strip 400 exhibits (distributes) different structural rigidities (structural rigidity regions) along the longitudinal direction (length direction) to adapt to the discretely distributed plaque environment and the severely tortuous vascular environment, and guide the calcified plaque to crack along the axial direction of the blood vessel. The first aspect of the present invention is to change the original single structural rigidity distribution of the strip 400 in the longitudinal direction (its length direction) (for example, Figure 20 Showing a strip structure with a single form and non-suspended connecting units), by combining connecting units of different forms and deploying them into the strip 400, at least some of the sawtooth unit groups (such as Figures 7 to 9 、 Figure 14 、 Figure 15 Among them, 800, 700, 800a, 700a, 800b, 700b, 800c, 7080c, 700c, 800d, 7080d, 710, 710b, 710c) have different structural rigidity from other sawtooth units; and / or, at least some sawtooth unit groups have different structural rigidity from other sawtooth unit groups (for example, 800, 700, 800a, 700a, 800b, 700b, 800c, 7080c, 700c, 800d, 7080d, 710, 710b, 710c of different forms, each of which has different structural rigidity). Form refers to the overall appearance and structural characteristics of an object, which includes not only shape, but also size, proportion, positional relationship and internal structure. Therefore, the second aspect of the present invention is to further change the form of the two connecting units of the same sawtooth unit so that the strip 400 can be used in some specific force-bearing environments (such as Figure 33 As shown), some sawtooth units (e.g., sawtooth unit 4011) are able to comply with this squeezing tendency compared to their sawtooth units (e.g., sawtooth unit 4012), and / or resist this squeezing tendency (e.g., sawtooth unit 4012 relative to sawtooth unit 4010).

[0088] It is understandable that the factors that are positively correlated with the crossability of the serrated balloon are trackability and compliance, which are similar to the relevant indicators for evaluating the crossability of conventional balloon catheters: pushability and trackability. Among them, the trackability and compliance of the serrated strip 400 (or the so-called blade) are the main factors affecting the crossability of the serrated balloon. By designing the serrated strip 400 (or the so-called blade) in the longitudinal direction to adaptively form a compliant area (for example, Figure 33 The middle 422 region has a tendency to conform to the curvature of the blood vessel 900 ) and a resistance region (e.g. Figure 33 The middle 421 area has a functional structure that conforms to the bending tendency of the blood vessel 900. Through this functional structure, the serrated strip 400 (or the so-called blade) can have better tracking and flexibility without sacrificing working stiffness (structural rigidity); through this functional structure, the serrated balloon has both high passability and high-efficiency cutting performance. When facing severe tortuosity of the blood vessel, it can still effectively guide the calcified plaque to crack along the axis of the blood vessel. The functional structure can be composed of a tooth (serrated unit) and connecting units on its front and rear sides, or it can be composed of a connecting unit and the teeth (serrated units) at both ends. Specifically, Figures 7 to 24As shown, the functional structure, under a certain state (for example, the expanded or unexpanded balloon is curved in an arc shape), can enable the teeth at both ends of at least some of the connecting units to jointly form a new rigid structural area / group (700, 800, 7080, 7080a, 7080b, 800a, 700a, 800b, 700b, 800c, 7080c, 700c, 800d, 7080d, 710, 710b, 710c), distributed in the longitudinal direction of the serrated strip (or the so-called blade) (which means that at this time the serrated strip (or the so-called blade) is no longer uniformly flexible in the longitudinal direction, which is different from the prior art). In the non-expanded state, the new rigid structural areas / groups (700, 800, 7080, 7080a, 7080b, 800a, 700a, 800b, 700b, 800c, 7080c, 700c, 800d, 7080d, 710, 710b, 710c) can assist the balloon in transmitting the force of the pushing rod to the balloon tip so that it can reach the lesion smoothly; in the expanded state, the new rigid structural areas / groups (700, 800, 7080) can provide local rigidity to assist / help / push the teeth toward the blood vessel wall or plaque, and even the connecting units provide potential energy to assist the balloon in squeezing the wedge or cone into the calcified plaque or hardened tissue of the blood vessel wall. The bow-shaped / arc-shaped / arch-shaped shape of the connecting unit is only one of the specific preferred technical means for realizing the serrated balloon with both high passability and high-efficiency cutting performance in the concept of the present invention. In addition, as long as it can be achieved that: the strips present (distribute) different structural rigidity (structural rigidity areas) along the longitudinal direction (length direction), other connecting structures should be understood as the internal technical means or external technical means of the present invention.

[0089] When the wedge-shaped portion 430 (often also called a wedge or a cone) of the serrated strip (or so-called blade) is subjected to a force (direct or indirect) from the blood vessel wall and perpendicular to the connection unit [or when the wedge-shaped portion 430 of the serrated strip (or so-called blade) is subjected to a lateral force from the blood vessel wall that causes the connection unit to bend and deform], the connection unit 421 has a smaller deformation, while the connection unit 422 has a larger deformation, causing the serrated strip 400 (or so-called blade) to exhibit different compliance performance area distributions along the longitudinal direction; this compliance performance area distribution makes When the serrated balloon is not expanded, the serrated strip 400 (or so-called blade) can help the balloon transmit the force of the push rod to the balloon tip so that it can reach the lesion smoothly; in the expanded state, the serrated strip (or so-called blade) can provide local rigidity to assist / help / push the teeth toward the blood vessel wall or plaque, and even the connection unit provides potential energy to assist the balloon in squeezing the wedge or cone into the calcified plaque or hardened tissue of the blood vessel wall (not shown in the figure); compared with the traditional uniform flexible connection, this regional distribution of flexible performance can improve the tracking performance of the serrated balloon. Further, as Figure 7 and Figure 9 As shown, this paired anisotropic connection unit structure has the characteristics of automatically forming a resistance state and a compliance state, and can naturally group the teeth of the blade / strip to improve its compliance; the anisotropic connection unit enables the tooth complex to form a longitudinal soft and hard distribution form, so that it can still maintain this good stiffness when cutting the patch, thereby improving the flexibility without significantly weakening the cutting performance of the tool, thereby ensuring its functional integrity.

[0090] In some embodiments, the overall stiffness of the serrated balloon can be adjusted / increased (or reduced to increase flexibility) by increasing the overall dimensions of the link. The compliance of a compliant link can be adjusted / increased, while the resistance of a resistant link can be reduced, by increasing the arch height. Increasing the chord length increases the compliance of a compliant link and reduces the resistance of a resistant link. When the serrated strips (or so-called blades) are curved in an arc or S-shape, at least some of the teeth have a tendency to conform to the curvature of the serrated strips (i.e., they are in a compliant state, in which case the link is referred to as a compliant link); and / or at least some of the teeth have a tendency to resist the curvature of the serrated strips (i.e., they are in a resistant state, in which case the link is referred to as a resistant link).

[0091] In some specific embodiments, Figure 6 As shown, the balloon 200 has a plurality of leaflets 210 in the folded state, and the teeth (or serrated strips 400) are located between two leaflets 210 and have substantially the same tilted shape as the leaflets 210. When the balloon is in the folded state and is advanced into a tortuous hollow anatomical structure, as shown in FIG. Figure 33 As shown, the arched shape of the connecting units 422 between some teeth can conform to the bending tendency of the hollow anatomical structure 900 to assist the balloon in bending through the tortuous cavity; and / or, the arched shape of the connecting units 421 between some teeth can not conform to the bending tendency of the hollow anatomical structure to assist the balloon in maintaining axial local rigidity. In some specific embodiments, when the tooth group (or serrated strip 400) having a combination of arched connecting units 422 and arched connecting units 421 is advanced through a tortuous hollow anatomical structure, some teeth 4010 can conform to the bending tendency of the hollow anatomical structure 900, while some teeth 4011 can not conform to the bending tendency of the hollow anatomical structure; as shown in FIG. Figure 33As shown, when some teeth 4012 are able to abut against the outer side (the outer side is the side away from the center of the curve, the inner side is the side closer to the center of the curve) of the hollow anatomical structure 900 and serve as fulcrums for other connecting units (or teeth), the chain link units (teeth 4012 - arcuate connecting units 421 - teeth 4011) form relative structural rigidity, providing sufficient support for the teeth 4010 while increasing the thrust transmission range, allowing the teeth 4010 to advance close to the outer side of the curve of the hollow anatomical structure 900. In some specific embodiments, the serrated balloon has an inflated state; when the inflated serrated balloon is in the intraluminal environment, some teeth that fail to contact the sclerotic plaque as desired can contact the sclerotic plaque through interaction with their connecting units; and / or some teeth that fail to contact the sclerotic plaque can contact the sclerotic plaque through indirect action of several connecting units on the serrated strip 400. It can be understood that, compared to those modified balloons with conventional high flexibility, the wedge or cone of the present serrated balloon no longer relies solely on the stiffness of the balloon after inflation to (extrude) the sclerotic plaque; the uneven distribution of the structural rigidity of the serrated strip 400 itself can also enhance / increase the squeezing effect (shear effect) of the teeth (in a local area) on the sclerotic plaque. This enhanced / increased squeezing effect is particularly evident in blood vessels with staggered sclerotic plaques. This is because the uneven vascular wall causes the adjacent teeth on both sides or one side of a certain tooth to be squeezed by the plaque, resulting in displacement. This displacement causes the connecting unit to deform and accumulate potential energy (especially the connecting unit with a suspended area between the two ends, whose deformation potential energy is more significant). If the connecting units on both sides of the tooth have (exist) a potential energy difference, this potential energy difference can cause the wedge or cone to sway (twist) in a serpentine manner and cooperate with the balloon to squeeze the wedge or cone into (drill into) the sclerotic plaque.

[0092] In some specific embodiments, the inflated state of the balloon exposes the teeth in the hollow anatomical structure; when the teeth are brought into contact with the desired object by pulling the inflated balloon through the proximal end of the catheter, the arched shape of the connecting units between some teeth can prevent the tooth base engagement surface from moving away from the balloon surface (especially when the wedge 430 is subjected to uneven force in the longitudinal direction and causes the tilting behavior), or the arched shape of the connecting units between some teeth can prevent the teeth from tilting in the longitudinal direction; and / or, the arched shape of the connecting units between some teeth can assist the wedge or cone to rest against the surface of the desired object. The inflated state of the balloon exposes the teeth in the hollow anatomical structure (inside the blood vessel lumen); when the teeth are brought into contact with the desired object by pulling the inflated balloon through the proximal end of the catheter, the arched shape of the connecting units between some teeth can prevent the teeth from tilting in the longitudinal direction; and / or, the arched shape of the connecting units between some teeth can assist the teeth to rest on the surface of the desired object. Furthermore, the deployment of the arched connecting units 427 near the two ends 490 of the strip 400 can improve the fatigue resistance of the strip 400g (having a single shape and non-suspended connecting units 428); Figures 20 to 24 As shown, the strip 400h has mixed-form connection units (arch connection units 427 / non-suspended connection units 428), while the strip 400g has only a single-form and non-suspended connection unit 428. After the same number of repeated inflation and deflation tests using the ISO10555-4:2013 standard, the strip 400h did not fail (as shown in the local magnification after the test). Figure 24 , no debonding or cracking was observed), while the strip 400g failed (as shown in the local magnification after the test). Figure 23 , debonding and cracking, the end 490 of the strip 400g is separated from the polymer base layer 300, and is lifted away from the balloon 200, and a crack g is formed, which extends from the end 490 of the strip 400g along its length direction).

[0093] In some specific applications, such as Figure 7 As shown, the serrated strip 400 is sequentially distributed with the first structural rigid unit (group) 700 and the second structural rigid unit (group) 800 in the longitudinal direction (long axis direction); in the direction from the base portion 410 toward the wedge portion 430, the rigidity of the first structural rigid unit (group) 700 is greater than the rigidity of the second structural rigid unit (group) 800. The first structural rigid unit (group) 700 and the second structural rigid unit (group) 800 are arranged in a staggered manner or partially overlapped or spaced apart or end to end. The first structural rigid unit (group) 700 may also be distributed only at one end or both ends of the serrated strip (or so-called blade). A third structural rigid unit (group) having a rigidity between the first structural rigid unit (group) and the second structural rigid unit (group) may also be provided. The third structural rigid unit (group) is generally considered to have no lateral compliance; the third structural rigid unit (group) may also be a group of teeth connected by straight rods; as shown in FIG. Figure 9 In the strip 400b structure shown, the third structural rigid unit (group) 710 between the first structural rigid unit (group) 700b and the second structural rigid unit (group) 800b does not have lateral compliance due to its straight rod shape. The third structural rigid unit (group) 710 in the strip 400b structure can also be replaced by a structural rigid unit (group) 710b; the connection unit of the structural rigid unit (group) 710 is the non-suspended connection unit 428, and the structural rigid unit (group) 710b is the suspended connection unit 423 (as shown in FIG. Figure 13 As shown). The structural rigid unit (group) 700 can be replaced with various forms, such as an arched connecting unit 424 (with straight rods on both shoulders) similar to the arched connecting unit 422, an arcuate connecting unit 427 with only a minor arc, etc. The structural rigid unit (group) 800 can be replaced with various forms, such as an arched connecting unit 425 (with straight rods on both shoulders) similar to the bowed connecting unit 421, an arcuate connecting unit 429 with only a minor arc, etc. By deploying connecting units with different forms in the strip, the strip can be formed as follows. Figure 7 The strip 400 shown, Figure 8 The strips 400a, Figure 9 The strip 400b shown, Figure 11 The strip 400c shown, Figure 14 The strip 400d, Figure 15 The strip 400e shown, Figures 21 and 22 The strip structure having mixed-form connection units such as the strip 400h enables the serrated balloon provided in the present invention to obtain better comprehensive performance including bending, sheathing and fatigue resistance.

[0094] The serrated strip 400 can typically be formed by etching or cutting away a portion of the metal material on both sides of the metal blade body (the wedge portion 430 side and the base portion 410 side) at specific intervals along the longitudinal direction of the blade (typically, the spacing between the connecting units is 0.1-10 mm, or longer), leaving the metal blade body material in the middle between the two sides to form a plurality of mixed-shaped connecting units. Considering the comprehensive performance of the serrated balloon, the strip of the present invention typically deploys arcuate or arched connecting units (these connecting units have arcuate geometric features or fan-shaped geometric features; for example, Figure 26 As shown, the fan-shaped geometric feature has a fan-shaped longitudinal section with an outer radius R1 and an inner radius R2); after making the originally difficult-to-bend metal blade flexible, a portion of the metal material is etched or cut to modify the blade body between each connecting unit to form the desired teeth ( Figure 17 As shown in 401 and 402, Figure 14 As shown 403, Figure 21This etching process gradually forms a connecting unit region formed by the two sides of the sawtooth strip 400 (the wedge portion 430 side - the base portion 410 side) being concave toward the middle. The connecting unit region includes an inclined groove 600 (such as the one located on the side of the wedge or cone) near the blade. Figure 28 As shown), and the non-enclosed area 500 (as shown) near the knife seat side (located on the side of the base portion 410, close to the base portion joint surface 412) Figure 28 and Figure 35 As shown). The inclined wall 610 of the inclined groove 600 is formed by the inclined setting of the end face of the wedge-shaped portion 430, which is used to prevent the wedge-shaped portion 430 from getting stuck with the cutting object and to increase the bending space of the connecting unit. Generally, the inclined groove 600 and the non-enclosed area 500 divide the connecting unit (bow-shaped connecting unit 421) into an upper arc and a lower arc. The upper arc has a significant arc design, which is intended to increase the flexibility of the structure so that it can better absorb and disperse stress when subjected to external force, thereby improving the stability of the structure. The lower arc also has an arc design, which is intended to increase the pushability of the structure so that it can better transmit and disperse force when subjected to external force, thereby improving the efficiency of the structure. The curvature of the upper arc is greater than that of the lower arc, or the arc length of the upper arc is greater than the arc length of the lower arc. The arc design of the upper and lower parts enables the connecting unit to better disperse stress and force when subjected to external force, thereby improving the rigidity and pushability of the structure. By etching, the serrated unit includes a base portion 410 and a wedge-shaped portion 430, and gaps are maintained between some base portions 410 by arched connecting units; the base portion 410 includes a base portion joint surface 412 facing the balloon. Between two serrated units, a non-enclosed area 500 is usually arranged close to the knife seat side (located on the side of the base portion 410, close to the base portion joint surface 412) (that is, the base portion joint surface 412 between at least some serrated units in the strip is non-continuous). In some specific applications, the strips of the serrated balloon have at least some connecting units that are non-enclosed arches (such as 422, 424, 427), and some connecting units that are non-arched (such as 423, 428, 426). Closed and non-closed are relative. For example, if there is a continuous base portion joint surface 412 (that is, there is no non-enclosed area 500) between two serrated units with bow-shaped / arched connecting units, it is closed; in another case, such as Figure 15 and Figure 16As shown, connecting unit 426 is composed of a pair of arcs fixed side by side to form a closed elliptical hole. Connecting unit 426 is also a form of arched closure. Of course, the connecting units of the serrated strip 400 do not necessarily have arcuate geometric features. They can also be straight rods, semicircular connecting units, or a combination of cylindrical coil spring connecting units and arcuate connecting units. In clinical use in severely tortuous blood vessels, the serrated balloon of the present invention can simultaneously achieve high permeability and efficient cutting effect.

[0095] In some specific scenarios (such as Figure 1 As shown), the bottom surface (base joint surface 412) between the two ends 490 of the strip 400 is all joined (bonded) to the outer surface of the balloon, but for some balloon bodies made of compliant or semi-compliant materials, this joining method cannot meet the fatigue resistance requirements; therefore, in some specific applications, the serrated strip 400 is not fixed to the balloon working area 260, and the two ends 490 of the strip 400 are respectively fixed on the serrated balloon non-working area 270 away from the balloon working area 260; the two ends 490 of the strip 400 can be joined and fixed to the serrated balloon by a hoop or bonding; with this arrangement, in a compliant or semi-compliant balloon carrier, in a filled state, the strip 400 can adapt to the deformation changes of the balloon body without failure.

[0096] like Figure 14 、 Figure 17 、 Figure 20 、 Figure 21 and Figure 25As shown, the serrated units in the serrated balloon of the present invention may preferably have one or a combination of 401, 402, 403, 404, and 405. The serrated units are used to focus force (pressure focusing) or cut, thereby controlling the morphology of plaque rupture at a relatively low balloon operating pressure (expansion pressure), causing the blood vessel and plaque to rupture along a predetermined path, thereby limiting damage to the blood vessel. For fibrous plaques with dense elastic fibers and hard calcified lesions, the serrated units can directionally sever the fibrous plaque and calcified ring, fully squeezing the plaque and reducing elastic recoil, significantly increasing the minimum lumen area and immediate lumen rate after stent implantation. For lesions with excessive proliferation of smooth muscle cells and fibrous tissue, the blades of the serrated units can incise the proliferating intimal tissue within the stent. Before balloon inflation, the teeth are contained within the balloon's concavities, preventing damage to the vessel. During inflation, the teeth extend beyond the balloon's surface, regularly and orderly incising the plaque, relieving hoop stress in the vessel wall, increasing plaque compression, and reducing intimal dissection and elastic recoil. Typically, a serrated balloon is used to create an array of holes within a desired vessel lumen using a plurality of wedge-shaped sections, thereby guiding the tearing of sclerotic plaque along the vessel's longitudinal axis. Furthermore, when the inflated serrated balloon is deployed within a vessel, some serrated elements that fail to contact the sclerotic plaque as intended can be brought into contact through interaction with their connecting elements (e.g., the bending direction of an arched connecting element is opposite to the curvature of the vessel wall, thereby forming an arched connecting element that resists the bending tendency of the vessel wall). Alternatively, some serrated elements that fail to contact the sclerotic plaque can be brought into contact through indirect interaction between several connecting elements along the strip (this interaction is typically caused by the diverse / anisotropic deformation of hybrid connecting elements).

[0097] In some embodiments, the sawtooth units (also called teeth) have defined geometric dimensions, such as Figure 25 and Figure 26As shown, for example, the length L1 is 0.05-5 mm, the width is 0.05-3 mm, and the height H1 is 0.05-3 mm; or the length L1 is 0.1-2 mm, the width is 0.1-2 mm, and the height H1 is 0.1-2 mm; or the length is 2-10 mm, the width is 0.5-5 mm, and the height is 0.2-4 mm. In some specific embodiments, the arch height H3 can be designed to be 0.1-1 times the difference between the tooth height and the colloid infiltration depth H2 of the tooth polymer base; the chord length L4 / L5 can be designed to be 0.2-3 times the tooth length. For example, if the tooth height is 0.5 and the polymer base depth is 0.2, the arch height can be designed to be 0.03-0.3; if the tooth length is 0.8, the chord length ranges from 0.16-2.4; all the above units are mm. The connecting unit can be made of metal materials with good human biocompatibility, such as stainless steel, nickel-titanium alloy, or aluminum-magnesium alloy, or biocompatible polymers such as PA12, PP, and PET. The connecting unit has defined geometric dimensions, such as a length of 0.1-0.5 mm (alternatively 0.15-1 mm) and a height of 0.05-1 mm (alternatively 0.1-1.5 mm). The wedge-shaped portion 430 has defined geometric dimensions, such as a length of 0.1-0.8 mm (alternatively 0.15-1.5 mm) and a height of 0.08-0.6 mm (alternatively 0.1-1 mm). The spacing between the two wedge-shaped portions 430 has defined geometric dimensions, such as a length of 0.1-0.5 mm (alternatively 0.08-2 mm).

[0098] In some specific embodiments, the sawtooth unit includes a base portion supporting a wedge-shaped portion; the base portion has a base fixing surface facing the outer surface of the balloon, and the wedge-shaped portion is disposed on the base portion away from the base fixing surface; and / or the wedge-shaped portion is configured to form a micro-hole with a diameter of less than 1 mm and a depth of less than 1 mm within a desired vascular lumen. Furthermore, some sawtooth units have a base portion with only one wedge-shaped portion; and / or some base portions are spaced apart by arched connecting units; and / or some wedge-shaped portions have a height that protrudes radially outward from the arched connecting units in the balloon and is less than 0.7 mm.

[0099] In some specific embodiments, Figure 34 and Figure 35As shown, two arcuate curved surfaces (4201, 4202) with substantially the same curvature are formed by etching or cutting the sawtooth strip 400 in opposite directions. The sawtooth strip 400 includes a discontinuous base portion engagement surface 412 facing the balloon 200. Above the base portion engagement surface 412 is a base portion 410 of teeth. The teeth also include a wedge-shaped portion 430 supported on the base portion 410, with the wedge-shaped portion 430 having an area intended to enhance force concentration or cutting action. The sawtooth strip 400 can typically be formed by etching or cutting away portions of metal material on both sides of the metal blade body (blade side - blade seat side) at specific intervals along the longitudinal direction of the blade (typically 0.1-10 mm or longer between connecting units), retaining the metal blade body material in the middle portion between the two sides to form a plurality of connecting units 420 having arcuate or fan-shaped geometric features. At least some of the base portions 410 are connected by connecting units to form a non-enclosed area 500 extending radially outward from the balloon 200 (in other words, the formation of the non-enclosed area 500 is caused by the spaced arrangement of the sawtooth units). The non-enclosed area 500 forms a mortise (or has a mortise shape), and the mortise and tenon structure with the polymer base layer 300 (i.e., the strip base) is used to improve the peeling strength of the sawtooth unit; and or, at least some of the base portion joint surfaces 412 are provided with mortises 413 (or 414) extending along the height direction of the sawtooth unit, and the mortise and tenon structure with the polymer base layer 300 is used to improve the peeling strength of the sawtooth unit, so as to enhance the diffusion of interfacial stress between the strip base and the strip. Figure 27 As shown, further, the ends of the connecting unit 420 fixed to the serrated unit have a transition section (or transition connection area) design. Some serrated units are connected by a connecting unit 420 that is at least partially longitudinally arched. One or both ends of the connecting unit 420 are arranged on the base portion and away from the base portion joint surface on an inclined pier 440. The inclined pier 440 is connected to the base portion 410 at an inclined angle and is not perpendicular to the base portion joint surface 412 (or not perpendicular to the radial direction of the balloon 200). This arrangement, on the one hand, helps the inclined pier 440 vectorize or disperse the pressure or tension it receives to various directions of the base portion 410. On the other hand, it helps the serrated strips or teeth transmit longitudinal thrust in various bending states (i.e., ensure the pushability of the balloon system).

[0100] In some specific embodiments, Figure 34As shown, the serrated balloon includes 400 pairs (groups) of serrated strips, which are arranged on both sides of the balloon axis; the 400 pairs (groups) of serrated strips have lateral compliance (on the same circumference of the balloon, the arc opening directions of the two connecting units of the 400 pairs of serrated strips are the same); these paired serrated strips 400 have the same structural rigidity (structural rigidity area) along the circumferential direction of the balloon; the 400 pairs (groups) of serrated strips adaptively form compliance areas and resistance areas in the axial direction of the balloon (or the longitudinal direction of the balloon), so that the balloon is not axially compliant. The free combination with the rigid area produces a length change of the chain link structure (the longitudinal length of the tooth group 400 is greater than the longitudinal length of the teeth on both sides thereof) to enhance the pushing ability (improve tracking performance), and help the serrated balloon to smoothly pass through complex and tortuous blood vessels (bifurcated blood vessels) in the unexpanded state and quickly reach the lesion site; for blood vessels with large angles, the resistance area of ​​the serrated balloon can be manipulated (twisted / pushed / pulled) to make it rest against the blood vessel wall (resistance state), and the compliance area of ​​the free end of the serrated balloon can be used to comply with the bending trend of the blood vessel to complete the bending or bypass the complex anatomical structure (compliant state).

[0101] In the present application, the opening direction of the arched connection unit 422 is opposite to that of the arched connection unit 421, that is, the arched connection unit 422 and the arched connection unit 421 are centrally symmetrically distributed with the axis origin of the serrated strip 400 as the center, so that the serrated strip 400 is S-shaped as a whole, which can disperse the force in multiple directions, thereby improving the flexibility of the flexible cutting component. If the arched connection unit 421 and the curved direction of the blood vessel are consistent, this part is in a flexible state; if the arched connection unit 422 and the curved direction of the blood vessel are opposite, this part is in a resistant state. When the serrated strip 400 of the present application passes through a coronary artery with a large angle, the arched connection unit 421 passes through the angle with high flexibility, while the arched connection unit 422 gives the serrated strip 400 a certain rigidity in a resistant state, so that the serrated strip 400 can smoothly pass through the complex and tortuous blood vessels and quickly reach the lesion site.

[0102] The connecting unit is an arc-shaped connecting rod (arc-shaped connecting rod). The longitudinal cross-section (two lines at both ends) of the connecting unit (arc-shaped connecting rod) is fan-shaped. The arc of the fan is less than 1π rad (the arc of the arc-shaped connecting rod is less than 1π rad), which is equivalent to the angle corresponding to the arc being less than 180°. For example, it can be 175°, 160°, 150°, 140°, 120°, 110°, 100°, 80°, 60°, etc. The transverse cross-section of the arc-shaped connecting rod is one of the regular geometric shapes such as rectangle, I-beam, ellipse, circle, trapezoid, etc., or the transverse cross-section of the arc-shaped connecting rod is irregular. These arc-shaped connecting rods have lateral compliance.

[0103] The arc openings of the connecting units with arched or fan-shaped geometric features are deliberately arranged in combination, such as the openings facing upwards (e.g. Figure 7 and Figure 8 The middle arched connecting unit 421) and the opening facing downward (such as Figure 7 and Figure 8 The middle arch connecting unit 422) forms a repeating unit, two openings facing upwards separated by two openings facing downwards form a repeating unit, an opening facing left and an opening facing right form a repeating unit, an opening facing left and an opening facing downwards form a repeating unit, and various other combinations can be arranged. These repeating units are sequentially connected to a number of teeth or sawtooth units (401 or 402 or 403, or a combination thereof) to form a serrated strip 400 (or so-called blade). When these serrated strips 400 (or so-called blades) are curved in an arc or S-shape, at least some of the teeth have a tendency to conform to the curvature of these serrated strips (i.e., they are in a compliant state); and / or, at least some of the teeth have a tendency to resist the curvature of these serrated strips (i.e., they are in a resistant state). This structural design can significantly improve the flexibility and cornering ability (tracking) of the serrated balloon without sacrificing the concentrated cutting effect of the blade. This anisotropic connection unit creates a longitudinally distributed softness and hardness within the toothed complex, maintaining good rigidity even when cutting through plaque. This improves compliance without significantly impairing the tool's cutting performance, ensuring full functionality. Of course, the shape of the connection unit is not limited to bows, arcs, or arches; it only needs to provide lateral compliance.

[0104] In some specific embodiments, Figures 17 to 19As shown, the area for the force-gathering effect of the wedge-shaped portion 430 is a tip 432 formed by surfaces converging toward a point; the area for the cutting effect of the wedge-shaped portion 430 is a blade (431, 433) formed by surfaces (such as 4332, 4312) converging toward a line. The blades (431, 433), also commonly referred to as leading edges or cutting surfaces, are the portions that come into direct contact with the plaque and are responsible for the primary cutting action. The primary force they are subjected to is shear, causing the plaque material to plastically deform and ultimately fracture. In some specific embodiments, the blade has an inclined slope toward the distal end of the catheter (e.g., toward tip 4321); and / or, the blade has an inclined slope toward the proximal end of the catheter (e.g., toward tip 4322). This orientation design can prevent the teeth from getting stuck when the user pushes and pulls the serrated balloon catheter to modify the notches or teeth on the plaque; it can also make it easier for the balloon to squeeze the wedge or cone on the teeth into the desired object to be cut (sclerotic plaque or fibrous plaque). The sawtooth unit includes a base portion and a wedge-shaped portion (or a conical portion). The leading edge 4311 (also called a blade or cutting surface, which directly contacts the plaque for cutting) of the sawtooth unit 401 is arranged parallel to the base portion joint surface 412, and the leading edge 4311 is sharp; the leading edge 4331 of the sawtooth unit 402 is arranged at an angle to the base portion joint surface 412, and the leading edge 4331 has a change from thick to thin, that is, the cutting surface changes from a wide surface to a sharp surface, and even forms a surface with both a blade and a tip.

[0105] Further explanation of the connection unit with bow-shaped geometric features. Figures 25 to 29 As shown, the connection unit has a bow-shaped geometric feature (such as Figure 29 The arched geometric features include an arc and a chord corresponding to the arc, the chord has a chord length (L2, L4, L5) geometric dimension, and the arc has an arc length or arc height (H3) geometric dimension; the chord length of the connecting unit is 0.2-3 times the longitudinal length of the tooth, and the arc length of the connecting unit is less than a semicircle (called a "minor arc"); or, the longitudinal section of the connecting unit has a fan-shaped geometric feature (such as Figure 26 As shown in FIG), the sector-shaped geometric features include an arc and a chord corresponding to the arc. The chord has a chord length geometric dimension, and the arc has an arc length or arc height geometric dimension. The chord length of the connecting unit is 0.2-3 times the longitudinal length of the tooth, and the arc length of the connecting unit is less than a semicircle. The arched connecting unit includes an arc portion, and the arc of the arc portion is less than 1π rad. Figure 29 , the bow-shaped connecting unit is simplified into an arc shape (the solid line inferior arc part in the figure), the arc shape has a chord length L2 and an arc height H3 (arc height); the tangents at both ends of the connecting unit are in contact and fixed with the vertical line of the tooth (the Y axis in the figure) at an angle ɛ, and the angle ɛ is not equal to 0; the ends of the longitudinal section of the bow ( Figure 28 In the figure, the dotted line on one side of the tooth shows the end of the connecting unit with a complete arch or fan shape) and the horizontal line of the tooth ( Figure 29The X-axis) is tilted (non-vertical); in other words, the extension line of the end of the arched portion of the connecting unit is not parallel to the vertical line of the teeth. It is understandable that the present invention does not expect the connecting unit to be too soft and lose certain mechanical properties (such as force transmission in the longitudinal direction, especially to achieve uniform thrust transmission over a long distance), so that the pushing performance of the serrated strip (or balloon system) is reduced, or the rigidity of the serrated strip is insufficient (the cutting or local force focusing effect is reduced); although the superior arc-shaped connecting unit (such as Figure 29 The design of the semicircle (dashed line in the middle) increases flexibility, but also reduces the rigidity of the zigzag strip structure. When subjected to a large load in the longitudinal direction, the arc part may undergo a large deformation (the two ends will be displaced toward the middle symmetry axis and elastically folded), affecting the overall stability of the zigzag strip. The superior arc-shaped connecting unit design will increase the resistance during the pushing process, because the curved path requires more pushing force to overcome friction and inertia. When a horizontal force ( Figure 29 The X-axis arrow points to the center of the arc connection unit, such as the thrust during surgical operation; the arc connection unit structure may experience bending deformation, especially in the middle area of ​​the connection unit, where significant deflection may occur; if the connection unit is designed to be similar to a minor arc arch bridge ( Figure 28 The arched connecting unit 420) may generate X-axis compression or tensile stress, which is beneficial to the stability and strength of the connecting unit; the arched connecting unit (arch bridge) with a structural shape between a straight rod and a U-shaped rod (major arc) has both the compressive and tensile properties of a straight rod and the flexibility of a U-shaped rod, so that the entire structure (such as a serrated strip or a balloon system) can maintain good stability and control under the action of thrust. When a force is applied in the opposite direction of the arc at one end (such as Figure 29 The Y-axis arrow points to the center), the connection unit may experience torsional and bending deformations. For example, during the cutting process, the serrated strip (or teeth) is subjected to a reaction force. The applied force may cause one side of the connection unit to be compressed and the other side to be stretched. This asymmetric stress distribution may affect the stability and durability of the connection unit. In addition, due to the presence of the teeth, this deformation may cause relative displacement between the teeth, thereby affecting the cutting effect. Compared with the long torque of the superior arc, the short torque of the inferior arc is more helpful in absorbing part of the torsional force and maintaining the structural rigidity of the serrated strip, so that the cutting effect or force-gathering effect of the teeth is not significantly affected by the increased flexibility of the serrated strip.

[0106] In structural engineering, deflection and rotation are important parameters for evaluating the deformation of structures such as beams and arches under load. High deflection indicates greater deformability and increased compliance, while low deflection indicates less deformability and poorer compliance. High rotation also indicates greater deformability and increased compliance, while low rotation indicates less deformability and poorer compliance. Therefore, in this application, deflection and rotation are used to describe the compliance of arched connection units.

[0107] First, Figure 30 For example, a single force applied to the simply supported beam at a distance x from its endpoint causes the beam to bend, resulting in deflection, which is the maximum displacement of the beam perpendicular to its original axis after the force is applied. The formula for calculating this deflection is shown in Equation 1.

[0108] Deflection (Formula I)

[0109] Where y is the deflection of the node at distance x from the endpoint, m; F is the single point force, N; L is the total length of the simply supported beam, m; E is the elastic modulus of the simply supported beam material, N / m 2 ; I is the moment of inertia of the section, m 4 , x unit is m.

[0110] To simplify the description, a single-point force F is applied to the end of the simply supported beam. The deflection is calculated as shown in Equation II, and the rotation angle is calculated as shown in Equation III:

[0111] Deflection (Formula II)

[0112] Corner (Formula III)

[0113] From Formula II, we can see that if the single-point force value F is smaller under the same deformation, the flexibility of the simply supported beam is better; if the deflection y is larger and the rotation angle θ is larger under the same single-point force value F, the flexibility of the simply supported beam is better.

[0114] When the cross-section and material of the simply supported beam remain unchanged, EI remains unchanged.

[0115] The principle of the flexibility of the arched connecting unit is as follows: to ensure that the spacing between the connectors is consistent with that of the straight connecting rods, half of their length remains L.

[0116] Form 2 is a fixed arched form, which can be considered as a curve formed by form 1 (straight line structure) under a certain force value P. The calculation formulas for its deflection y1 and rotation angle θ0 can be deduced as follows:

[0117] Deflection =H (Formula III)

[0118] Corner (Formula IV)

[0119] tan =H / L (Formula V)

[0120] From this we can deduce that L= (Formula VI)

[0121] Assumptions ,but (formula )

[0122] The function graph of Figure 7 .

[0123] from Figure 31 It can be seen that in the range of (0, π / 2), it is always less than 1, so L is always less than L′.

[0124] like Figure 31 As shown, the curve of form 2 is treated as a statically determinate system under the force P value, and the same force F is superimposed to form the curve of form 3. According to the superposition principle, in the form equivalent to a straight rod, the deflection value of form 3 is increased.

[0125] Deflection (Mode )

[0126] Corner (Mode )

[0127] like Figure 32 As shown, in form 3, the deflection y′ of the arch connection unit is always greater than the deflection y of the simply supported beam (Formula II), and the rotation angle θ′ of the arch connection unit is always greater than the rotation angle θ of the simply supported beam (Formula III).

[0128] Therefore, when the arched connection unit is consistent with the bending angle of the blood vessel, the arched connection unit has stronger flexibility than the linear connection piece; when the arched connection unit is opposite to the bending angle of the blood vessel, the arched connection unit will form a spring structure to resist deformation to increase reverse rigidity.

[0129] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A serrated balloon comprising a balloon and a strip disposed on the outer surface of the balloon; the strip comprising a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated units comprising a wedge-shaped portion; characterized in that: The same connecting unit connects two serrated units to form a serrated unit group. When the wedge-shaped portion on the strip is in an extruded state, at least some of the serrated unit groups have structural rigidity different from that of other serrated unit groups; and / or, at least some of the serrated unit groups have structural rigidity different from that of other serrated unit groups. The connecting unit includes a resistance type and a compliance type.

2. A serrated balloon comprising a balloon and a strip disposed on the outer surface of the balloon; the strip comprising a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated units comprising a wedge-shaped portion; characterized in that: The same connecting unit connects two sawtooth units to form a sawtooth unit group, and at least some sawtooth unit groups have different structural rigidity from other sawtooth unit groups; the connecting unit includes a resistance type and a compliance type.

3. A serrated balloon comprising a balloon and a strip disposed on the outer surface of the balloon; the strip comprising a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated units comprising a wedge-shaped portion; characterized in that: At least some of the connection units are in a non-closed arch shape, and some of the connection units are in a non-arch shape; the connection units include resistance type and compliance type.

4. A serrated balloon comprising a balloon and a strip disposed on the outer surface of the balloon; the strip comprising a plurality of serrated units and a plurality of connecting units connected between two serrated units; the serrated units comprising a wedge-shaped portion; characterized in that: The connecting unit is in the shape of a non-closed arch; there are at least two connecting units whose arch opening directions are opposite to each other.

5. The serrated balloon according to any one of claims 1 to 4, characterized in that: The strip is used to form a hole array in a desired blood vessel lumen through a plurality of wedge-shaped portions, so as to guide the tearing of the hardened plaque along the long axis of the blood vessel.

6. The serrated balloon according to claim 5, characterized in that: The serrated balloon has an inflated state; the inflated serrated balloon is in an intravascular environment, and some serrated units that fail to contact the sclerotic plaque as expected can contact the sclerotic plaque through interaction with their connecting units; and / or, some serrated units that fail to contact the sclerotic plaque as expected can contact the sclerotic plaque through the indirect action of several connecting units on the strip.

7. The serrated balloon according to any one of claims 1 to 4, characterized in that: The serrated balloon further comprises a catheter component having the functions of a liquid guide channel and a manipulation function.

8. The serrated balloon according to any one of claims 1 to 4, characterized in that: At least some of the linking units are laterally compliant.

9. The serrated balloon according to any one of claims 1 to 4, characterized in that: The sawtooth unit includes a base portion supporting the wedge-shaped portion; the base portion has a base fixing surface facing the outer surface of the balloon, and the wedge-shaped portion is arranged on the base portion away from the base fixing surface; and / or, the wedge-shaped portion is used to form micro-holes with a pore diameter of less than 1 mm and a pore depth of less than 1 mm in a desired blood vessel lumen; And / or, the strip is made of metal material.

10. The serrated balloon according to claim 9, characterized in that: The serrated balloon further includes a strip base disposed on the outer surface of the balloon, the strip base being used to reduce the concentration of force from the strip acting perpendicularly to the outer surface of the balloon and / or to resist lateral tipping of the strip.

11. The serrated balloon according to claim 9, characterized in that: The base portion on some sawtooth units deploys only one wedge; and / or, gaps are maintained between some of the base portions by arched connecting units; And / or, some of the wedge-shaped portions have a height that protrudes radially outward from the balloon relative to the arched connecting unit and is less than 0.7 mm.

12. The serrated balloon according to claim 10, characterized in that: A mortise is provided between the two base portions of the strip, and a part of the strip base and the mortise form a mortise and tenon structure to enhance the peeling strength and / or interface stress diffusion between the strip and the strip base; And / or, the strip base is a high molecular polymer.

13. The serrated balloon according to any one of claims 3 to 4, characterized in that: The arched connecting unit includes an arc-shaped portion, and the arc of the arc-shaped portion is less than 1 π rad.

14. The serrated balloon according to any one of claims 1 to 4, characterized in that: The strip is not fixed to the working area of ​​the balloon.

15. The serrated balloon according to claim 14, characterized in that: The balloon is a compliant balloon or a semi-compliant balloon.

16. The serrated balloon according to claim 14, characterized in that: Two ends of the strip are respectively fixed on the serrated balloon away from the working area of ​​the balloon.

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