Balloon catheter assembly

Abstract

This specification discloses a balloon catheter assembly with a constraint structure, including a catheter hub, a balloon, and a catheter connected between the catheter hub and the balloon; the balloon is covered by a constraint structure, the constraint structure including a proximal connection end, a distal connection end, and an action segment connecting the proximal connection end and the distal connection end, wherein the width of at least one connecting rod of the proximal connection end and / or the distal connection end is greater than the width of at least one connecting rod of the action segment.

Description

[0001] Case Analysis

[0002] This application is a divisional application of Chinese patent application CN 202111363690.3 entitled “A balloon catheter assembly with a constraint structure”, filed on November 17, 2021. Technical Field

[0003] This manual relates to the field of medical devices, and in particular to a balloon catheter assembly. Background Technology

[0004] The application of percutaneous transluminal angioplasty (PTA) represents a significant advancement in the treatment of vascular diseases. After years of development, balloon angioplasty has become a widely recognized and mature technique in the medical field. Balloon angioplasty primarily targets the revascularization of narrowed or occluded blood vessels. It involves inserting a catheter with an inflatable balloon into the vascular system, and then, under external pressure, inflating the balloon within the narrowed or occluded area of ​​the vessel. This applies radial pressure to the inner wall of the vessel, widening the narrowed or occluded area and improving blood flow.

[0005] During inflation, an inflatable balloon is constrained by an external restraint structure, thus achieving a specific size and shape of inflation. However, in practical applications, it has been found that the restraint structure may fracture during balloon inflation due to insufficient toughness or excessive stress concentration, thereby damaging the balloon and potentially causing serious harm to the patient. Therefore, it is necessary for those skilled in the art to research a more reliable balloon catheter assembly and restraint structure. Summary of the Invention

[0006] This specification provides a balloon catheter assembly, including a catheter hub, a balloon, and a catheter connected between the catheter hub and the balloon; the balloon is surrounded by a constraint structure, the constraint structure including a proximal connection end, a distal connection end, and an action segment connecting the proximal connection end and the distal connection end, wherein the width of at least one connecting rod of the proximal connection end and / or the distal connection end is greater than the width of at least one connecting rod of the action segment.

[0007] In some embodiments, the width of at least one connecting rod connecting the proximal end and / or the distal end is 2 to 4 times the width of at least one connecting rod of the functional segment.

[0008] In some embodiments, the catheter includes an inner tube, an outer tube sleeved outside the inner tube, and a connecting tube disposed between the outer tube and the balloon; the distal end of the outer tube is connected to the connecting tube, and the outer surface of the connecting tube is connected to the proximal end of the balloon through an adhesive layer.

[0009] In some embodiments, the connecting tube is made of nylon or polyether block polyamide, and the adhesive layer is made of polyether block amide.

[0010] In some embodiments, the connecting tube has a length of 8mm-15mm.

[0011] In some embodiments, the adhesive layer has an L-shaped cross section.

[0012] In some embodiments, the constraint structure is a memory alloy bracket formed by integral cutting, and at least one connecting intersection of each wire in the memory alloy bracket forms at least one circular arc buffer segment.

[0013] In some embodiments, the balloon is a single-layer balloon made of nylon, nylon copolymer and / or polyterephthalate plastic, or a double-layer balloon with a polyterephthalate plastic inner layer and a nylon outer layer.

[0014] In some embodiments, the connecting proximal end of the constraint structure is fixedly connected to the proximal end of the adhesive layer.

[0015] In some embodiments, each wire in the constraint structure has a circular, trapezoidal and / or triangular cross section. BRIEF DESCRIPTION OF DRAWINGS

[0016] The embodiments of the present specification will be further illustrated in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, wherein:

[0017] Figure 1 is a structural schematic diagram of a balloon catheter assembly of some embodiments of the present specification.

[0018] Figure 2 is a schematic diagram of a connecting rod of a balloon catheter assembly of some embodiments of the present specification.

[0019] Figure 3 is a partially enlarged schematic diagram of a balloon catheter assembly of some embodiments of the present specification.

[0020] Figure 4 is a connecting schematic diagram of an adhesive layer of a balloon catheter assembly of some embodiments of the present specification.

[0021] Figure 5 is a schematic diagram of a wire connection of a constraint structure of a balloon catheter assembly of some embodiments of the present specification.

[0022] Figure 6 is a schematic diagram of a cross section of a wire of a constraint structure of a balloon catheter assembly of some embodiments of the present specification. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings required to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some examples or embodiments of the present specification, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor on the basis of these drawings. It should be understood that these exemplary embodiments are only given to enable those skilled in the art to better understand and implement the present specification, and do not limit the scope of the present specification in any way. Unless the context clearly indicates otherwise or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0024] As shown in the specification and claims, unless the context clearly indicates otherwise or otherwise stated, the words "one", "a", "an", and / or "the" do not specifically refer to the singular, but can also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment".

[0025] In the description of the present specification, it should be understood that the terms "distal", "proximal", "inner", "outer", "away", "close", "one end" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present specification and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present specification.

[0026] In the present specification, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, "connection" can be fixed connection, or detachable connection, or integral; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements, or can represent the interaction relationship between two elements. Unless otherwise explicitly limited, for those skilled in the art, the specific meaning of the above terms in the present specification can be understood according to the specific circumstances.

[0027] In the process of blood vessel revascularization of stenosis and occlusion using balloon angioplasty, the balloon catheter can be constrained by the constraint structure sleeved outside, so as to have a certain inflation size and inflation shape, so that the stress on the blood vessel is more accurate. However, in some practical applications, it is found that the constraint structure may be broken due to problems such as too low toughness or too concentrated stress when the balloon inflates, thereby damaging the balloon and even causing serious harm to the patient.

[0028] To solve the above problems, some embodiments of the present specification provide a balloon catheter assembly, which increases the width of the connecting rod located at the connecting proximal end and / or the connecting distal end of the constraint structure before electrolytic polishing, so that the width of at least one connecting rod located at the connecting proximal end and / or the connecting distal end of the constraint structure is greater than the width of at least one connecting rod located at the action section of the constraint structure, thereby avoiding the connecting rod located at the connecting proximal end and / or the connecting distal end of the constraint structure from being too low in toughness due to excessive loss during electrolytic polishing.

[0029] In some other embodiments of the present specification, the stress distribution of the constraint structure in the balloon catheter assembly can also be changed by changing the shape of the constraint structure. For example, at least one circular arc buffer section can be formed at the connecting intersection of the constraint structure, thereby avoiding the connecting intersection from being broken due to too concentrated stress during inflation or contraction.

[0030] The balloon catheter assembly provided by the embodiments of the present specification will be described in detail below with reference to the accompanying drawings.

[0031] Figure 1 is a structural schematic diagram of the balloon catheter assembly of some embodiments of the present specification.

[0032] Referring to Figure 1 In some embodiments, the balloon catheter assembly 100 can include a catheter seat 110, a balloon 120, and a catheter 130 connected between the catheter seat 110 and the balloon 120, wherein the balloon 120 is wrapped outside with a constraint structure 140 for limiting the inflation size and inflation shape of the balloon.

[0033] In some embodiments, the balloon catheter assembly 100 can include one or more balloons 120, which can be expanded or contracted under the control of an operator (such as a doctor or a nurse). When the balloon 120 is expanded, it can act on the inner wall of the blood vessel, thereby inflating the stenosis and occlusion area in the blood vessel, and then widening the stenosis and occlusion area in the blood vessel, so that the blood flow is more unobstructed.

[0034] In some embodiments, when the balloon catheter assembly 100 includes a plurality (such as two or more) of balloons 120, the plurality of balloons 120 can be arranged equidistantly or unequidistantly in a certain order.

[0035] In some embodiments, the plurality of balloons 120 can be classified into distal balloons and proximal balloons according to their distance relationship with the catheter seat 110. Among them, the distal balloon can refer to one or more balloons of the plurality of balloons away from the catheter seat 110, and the proximal balloon can refer to one or more balloons of the plurality of balloons close to the catheter seat 110.

[0036] In some embodiments, the material of the balloon 120 can be one or more of nylon, nylon copolymer, or polyterephthalate plastic (such as PET (Polyethylene terephthalate, polyester resin)).

[0037] The catheter seat 110 can be used to connect or fix the catheter 130. In some embodiments, the catheter 130 can include a plurality of internal cavities (such as a guide wire cavity, a distal balloon expansion cavity, a proximal balloon expansion cavity, a drug loading cavity, etc.), and the catheter seat 110 can be provided with interfaces corresponding to each internal cavity of the catheter 130.

[0038] For example, in some possible embodiments, the catheter seat 110 can include a first interface, a second interface, a third interface, and a fourth interface. The first interface can be connected with the guide wire cavity of the catheter 130 for guiding through the guide wire or detecting the pressure in the lumen during surgery; the second interface can be communicated with the distal balloon expansion cavity of the catheter 130, and the third interface can be communicated with the proximal balloon expansion cavity of the catheter 130. The second interface and the third interface can be used to inject liquid or gas into the distal balloon and the proximal balloon respectively during surgery, so as to control the expansion of the balloon bodies in a certain order or simultaneously, and make the two end balloon bodies swell to temporarily block the blood flow, thereby forming a closed "vascular cavity"; the fourth interface can be communicated with the drug loading cavity of the catheter 130, so that the filling device is used to first suck back and then inject through the fourth interface during surgery, so that the blood in the closed vascular cavity dissolves the drug in the drug loading cavity and then returns to the closed vascular cavity.

[0039] It should be noted that the structure of the catheter seat 110 and the catheter 130 described above is only exemplary. In some other embodiments, the catheter 130 can include more or fewer internal cavities, and accordingly, the catheter seat 110 can include more or fewer interfaces.

[0040] The constraint structure 140 can be wrapped outside the balloon 120, so as to limit the inflation size and inflation shape of the balloon 120. Referring to Figure 2In some embodiments, the constraining structure 140 can include a proximal connecting end 141, a distal connecting end 142, and an acting section 143 connected between the proximal connecting end 141 and the distal connecting end 142 and acting on the balloon 120 to limit the inflation size and inflation shape of the balloon 120. The proximal connecting end 141 can refer to an end close to the catheter seat 110, and the distal connecting end 142 can refer to an end away from the catheter seat 110.

[0041] In some embodiments, the acting section 143, the proximal connecting end 141, and / or the distal connecting end 142 of the constraining structure 140 can each include at least one connecting rod. The connecting rods of the proximal connecting end 141 and / or the distal connecting end 142 can be connected with other components of the balloon catheter assembly 100 to fix the constraining structure 140. The connecting rods of the acting section 143 can be connected with each other and form a mesh ring structure capable of deforming with the inflation or deflation of the balloon 120 to wrap around the balloon 120 to limit the inflation size and inflation shape of the balloon 120.

[0042] In some embodiments, the biocompatibility of the constraining structure 140 is related to two factors, i.e., the host reaction induced by the material and the degradation of the material in the human body environment. For example, in the case of a constraining structure made of nickel-titanium alloy, the dissolution of nickel ions can cause problems such as allergy and inflammation, and the release rate of nickel ions is closely related to the surface quality of the constraining structure (specifically, the higher the corrosion resistance of the constraining structure, the slower the release rate of nickel ions, and the corrosion resistance of the constraining structure depends on its specific structure and surface morphology).

[0043] The surface morphology can be improved by electrolytic polishing, specifically, the surface roughness can be reduced. However, when the constraining structure 140 is processed by electrolytic polishing, since the number of connecting rods of the acting section 143 is greater than the number of connecting rods of the proximal connecting end 141 and / or the distal connecting end 142, the current passing through the connecting rods located at the proximal connecting end 141 and / or the distal connecting end 142 is greater than the current passing through the connecting rods located at the acting section 143, thereby causing excessive width loss of the connecting rods located at the proximal connecting end 141 and / or the distal connecting end 142 after polishing, and further causing certain safety hazards of the constraining structure 140.

[0044] Therefore, in order to avoid excessive width loss of the connecting rods located at the proximal connecting end 141 and / or the distal connecting end 142 after polishing, in some embodiments, the width of the connecting rods of the proximal connecting end 141 and / or the distal connecting end 142 can be increased before electrolytic polishing, so as to compensate for the loss of rod width during the electrochemical polishing process.

[0045] Based on this, in some embodiments, the width of at least one connecting rod located at the connection proximal end 141 and / or the connection distal end 142 can be greater than the width of at least one connecting rod located at the action section 143, so as to ensure that the connecting rod located at the connection proximal end 141 and / or the connection distal end 142 and the connecting rod located at the action section 143 have a width satisfying predetermined requirements after electrolytic polishing. It should be noted that the "width" of the connecting rod described in the present specification can refer to the dimension perpendicular to the extension direction of the length of the connecting rod.

[0046] Figure 2 is a schematic view of a connecting rod of a balloon catheter assembly according to some embodiments of the present specification.

[0047] Referring to Figure 2 In some embodiments, the connecting rod 1411 located at the connection proximal end 141 and the connecting rod 1421 located at the connection distal end 142 can be in a substantially parallel state, and the connecting rod 1431 located at the action section 143 can be connected to a plurality of S-shaped metal wires to form a mesh structure wrapped outside the balloon 120. Wherein, the "substantially parallel" between the connecting rod 1411 located at the connection proximal end 141 and the connecting rod 1421 located at the connection distal end 142 can refer to the included angle between the two being less than or equal to 15°.

[0048] Referring to Figure 2 In some embodiments, the number of connecting rods 1431 located at the action section 143 can be twice the number of connecting rods 1411 located at the connection proximal end 141 or the number of connecting rods 1421 located at the connection distal end 142, in other words, the current flowing through the connecting rods 1411 and 1421 can be twice the current flowing through the connecting rods 1431.

[0049] Based on this, in some embodiments, in order to ensure that the connecting rod 1411 and / or 1421 located at the connection proximal end 141 and / or the connection distal end 142 and the connecting rod 1431 located at the action section 143 have a width satisfying predetermined requirements after electrolytic polishing, the width of the connecting rod 1411 and / or 1421 of the connection proximal end 141 and / or the connection distal end 142 before electrolytic polishing can be set to 1.5 times to 4 times the width of the connecting rod 1431 of the action section 143.

[0050] Optionally, in some embodiments, the width of connecting rod 1411 and / or 1421 may be 2 to 4 times the width of connecting rod 1431; in some embodiments, the width of connecting rod 1411 and / or 1421 may be 1.5 to 3.5 times the width of connecting rod 1431; in some embodiments, the width of connecting rod 1411 and / or 1421 may be 1.5 to 3 times the width of connecting rod 1431; in some embodiments, the width of connecting rod 1411 and / or 1421 may be 2 to 3 times the width of connecting rod 1431.

[0051] In some embodiments, the width W1 of the connecting rods 1411 and / or 1421 located at the proximal end 141 and / or the distal end 142 before electropolishing can be between 0.2 mm and 0.3 mm, and the width W2 of the connecting rod 1431 located at the active section 143 before electropolishing can be between 0.08 mm and 0.15 mm.

[0052] It should be noted that the above quantitative relationship between connecting rod 1431 and connecting rods 1411 and / or 1421 is merely illustrative. In some embodiments, the ratio of the number of connecting rods 1431 to the number of connecting rods 1411 or 1421 may be less than or greater than 2, and correspondingly, the ratio of the width of connecting rods 1411 and / or 1421 to the width of connecting rod 1431 may be less than 2 or greater than 4.

[0053] Figure 3 This is a schematic diagram of the balloon catheter assembly of some other embodiments of this specification.

[0054] like Figure 3 As shown, in some embodiments, the catheter 130 may include a stress diffusion tube 131, an inner tube 132, an outer tube 133 sleeved outside the inner tube 132, and a connecting tube 134 disposed between the outer tube and the proximal end 1201 of the balloon. One end of the stress diffusion tube 131 is connected to the catheter seat 110, and the other end is connected to the proximal end of the outer tube 133. The distal end of the outer tube 133 is connected to the proximal end of the connecting tube 134, and the distal end of the connecting tube 134 is connected to the proximal end 1201 of the balloon 120 via an adhesive layer 135.

[0055] In some embodiments, the inner tube 132 may be a tubular element, such as a round tube, a square tube, or other regular / irregular shaped elements. In some embodiments, the inner tube 132 may include multiple inner cavities, such as a guidewire cavity, a distal balloon expansion cavity, a proximal balloon expansion cavity, and a drug-loaded cavity, for accommodating the guidewire, distal expansion gas or liquid, proximal expansion gas or liquid, active drug, etc., respectively.

[0056] In some embodiments, the inner tube 132 can be made of metal or polymeric material, such as stainless steel, polyamide, polyether block amide, polyurethane, etc. In some embodiments, the inner wall and / or outer wall of the inner tube 132 can include a lubricating coating, such as a polytetrafluoroethylene coating, etc., to reduce its frictional resistance.

[0057] In some embodiments, the outer tube 133 can be woven with metal wires. In order to make the outer tube 133 have better directivity when entering the blood vessel system, in some embodiments, the metal wires used can be flat wires (i.e., flat metal wires).

[0058] In some embodiments, in order to reduce the size of the outer tube 133, the metal wires can be stainless steel wires or nickel-titanium wires, preferably flat stainless steel or nickel-titanium wires with a thickness of less than 0.2 mm, such as 0.1 mm, 0.08 mm, 0.15 mm, etc., so that the inner diameter of the entire outer tube 133 is controlled to be 0.6 mm to 1.2 mm, and the outer diameter is correspondingly controlled to be 0.8 mm to 1.4 mm.

[0059] In some embodiments, the outer tube 133 can include an outer layer and an inner layer, and the material of the outer layer and / or the inner layer can be polyimide, polyether block amide, or polytetrafluoroethylene, etc. In some embodiments, in order to control the thickness of the outer layer and / or the inner layer to be less than 0.2 mm, the metal wires can be directly wound on the inner layer of the outer tube 133, or the metal wires can be extruded together with the outer layer and / or the inner layer.

[0060] In some embodiments, the outer tube 133 can be bonded to the stress dispersion tube 131 by an adhesive, for example, the stress dispersion tube 131 and the outer tube 133 can be positioned, and then an adhesive is added. After the adhesive is applied, capillary action can occur through the narrow space between the two, thereby fully bonding the two. Exemplary adhesives can include polyimide adhesive, polytetrafluoroethylene adhesive, etc.

[0061] In some embodiments, in order to enhance the pushability and twistability of the balloon 120, the connection between the distal end of the outer tube 133 and the proximal end of the balloon 120 can be connected through the connecting tube 134 and the bonding layer 135.

[0062] In some embodiments, the distal end of the outer tube 133 can be connected to the proximal end of the connecting tube 134, and the distal end of the connecting tube 134 can be connected to the proximal end 1201 of the balloon 120 through the bonding layer 135. In some embodiments, in order to reduce the outer diameter size of the catheter 130 as much as possible, the bonding layer 135 can be connected to the outer surface of the connecting tube 134 and / or the inner surface of the proximal end 1201 of the balloon 120.

[0063] In some embodiments, in order to achieve sufficient bonding, the bonding layer 135 can be bonded with the inner surface of the proximal end 1201 of the balloon 120, the outer surface of the distal end of the connecting tube 134, and the cross section of the distal end of the connecting tube 134 at the same time.

[0064] In some embodiments, the outer tube 133 and the radial dimension of the balloon 120 can have a certain difference, in order to ensure that the two ends of the connecting tube 134 can be reliably connected with the proximal end 1201 of the balloon 120 and the distal end of the outer tube 133 respectively, the connecting tube 134 can be a variable diameter structure. Specifically, the size of the two ends of the connecting tube 134 can be different, wherein the size of the end close to the outer tube 133 can be the same as or close to the size of the outer tube 133, and the size of the end close to the proximal end 1201 of the balloon can be the same as or close to the size of the proximal end 1201 of the balloon.

[0065] In some embodiments, in order to make the balloon segment have better torsion performance, a connecting tube 134 with softer material can be used to connect the outer tube 133 and the proximal end 1201 of the balloon 120. In some embodiments, the connecting tube 134 and the bonding layer 135 can adopt different soft materials.

[0066] In some embodiments, in order to facilitate bonding, the bonding layer 135 can adopt a material with a lower melting point. In some embodiments, the melting point of the material used by the bonding layer 135 can be lower than the melting point of the material used by the connecting tube 134.

[0067] In some embodiments, the connecting tube 134 can be made of nylon or polyether block polyamide (PEBAX) material, and the bonding layer 135 can be made of polyether block amide (PEBA) material.

[0068] In some embodiments, considering that soft material can increase the torsion performance, but at the same time it can also cause the push performance to be poor, therefore, by setting the bonding layer 135 at the connecting tube 134, on the one hand, the connecting tube 134 made of soft material can be slightly thickened, so that its toughness is enhanced, and on the other hand, since the material used by the bonding layer 135 has a lower melting point, it can also quickly melt when heated, so as to firmly connect the distal end of the outer tube 133 and the proximal end 1201 of the balloon.

[0069] Figure 4 is a schematic diagram of a bonding layer of a balloon catheter assembly according to some embodiments of the present specification.

[0070] Referring to Figure 4In some embodiments, in order to achieve sufficient bonding between the bonding layer 135 and the connecting tube 134 and the proximal end 1201 of the balloon, the bonding layer 135 can be provided in an L-shaped cross-section structure. Specifically, the bonding layer 135 can include a first connecting portion 135-1 and a second connecting portion 135-2, wherein the thickness of the first connecting portion 135-1 is greater than the thickness of the second connecting portion 135-2, the first connecting portion 135-1 can be connected to the cross-section of the distal end of the connecting tube 134 and the inner surface of the proximal end 1201 of the balloon at the same time, and the second connecting portion 135-2 can be connected to the outer surface of the connecting tube 134. It should be noted that the connection between the connecting tube 134 and the proximal end 1201 of the balloon can be made more reliable by increasing the connection area between the two through the L-shaped cross-section structure of the bonding layer 135.

[0071] In some embodiments, the bonding layer 135 can be heat welded by using laser, heat radiation metal jaws, RF energy or other methods. In some embodiments, the heat welding temperature can be controlled in two stages: in the first stage, the welding temperature is raised to 100-110°C for 20-30s to soften the bonding layer 135; in the second stage, the welding temperature is raised to 150-160°C for 80-100s to sufficiently weld the bonding layer 135.

[0072] In some embodiments, it has been found through experiments that when the length of the connecting tube 134 is too long (for example: greater than 15mm), the pushing force cannot be transmitted, thereby causing poor pushing performance, and when the length of the connecting tube 134 is too short (for example: less than 8mm), the twisting performance is poor due to the close distance between the multiple welding points.

[0073] Based on the above test results, in some embodiments, in order to ensure the comprehensive twisting performance and pushing performance of the balloon segment, the length of the connecting tube 134 can be controlled to be between 8mm and 15mm. Alternatively, in some embodiments, the length of the connecting tube 134 can be 8mm-10mm; in some embodiments, the length of the connecting tube 134 can be 10mm-15mm; in some embodiments, the length of the connecting tube 134 can be 9mm-12mm.

[0074] In some embodiments, it is considered that the twisting performance and pushing performance of the balloon segment are also related to the thickness of the connecting tube 134, whether the bonding layer 135 is added, and the thickness of the bonding layer 135. In order to ensure the comprehensive twisting performance and pushing performance of the balloon segment, in some embodiments, the bonding layer 135 can be provided at the connection between the connecting tube 134 and the proximal end 1201 of the balloon, and the thickness of the bonding layer 135 can be controlled to be between 0.1mm and 0.2mm, and the thickness of the connecting tube 134 can be controlled to be between 0.1mm and 0.2mm.

[0075] To verify the feasibility of the thickness of the adhesive layer 135 and the thickness of the connecting tube 134, the applicant has conducted corresponding tests. The exemplary test results are shown in the following table:

[0076]

[0077]

[0078] As can be seen from the above table, when the adhesive layer 135 is provided at the connection between the connecting tube 134 and the proximal end 1201 of the balloon, and the thickness of the adhesive layer 135 is controlled between 0.1mm-0.2mm, and the thickness of the connecting tube 134 is controlled between 0.1mm-0.2mm, the balloon catheter assembly 100 has a larger maximum pushing force and better bending ability (i.e. better twisting performance and pushing performance). Exemplarily, in some embodiments, the thickness of the connecting tube 134 can be set to 0.1mm, and the thickness of the adhesive layer 135 can be set to 0.2mm; in some embodiments, the thickness of the connecting tube 134 can be set to 0.2mm, and the thickness of the adhesive layer 135 can be set to 0.1mm.

[0079] In some embodiments, in order to meet the needs of the periphery, the length of the balloon 120 can be 20mm-40mm, and the diameter can be 5mm-16mm. Alternatively, in some embodiments, the length of the balloon 120 can be 20mm-30mm, and the diameter can be 5mm-10mm; in some embodiments, the length of the balloon 120 can be 25mm-35mm, and the diameter can be 8mm-12mm.

[0080] In some embodiments, the balloon 120 can be a single-layer balloon made of nylon or nylon copolymer, or a polyterephthalic plastic, or a double-layer balloon made of a polyterephthalic plastic for the inner layer and nylon for the outer layer. It should be noted that in some embodiments, by setting the balloon 120 as a double-layer balloon made of a polyterephthalic plastic for the inner layer and nylon for the outer layer, the excessive force exerted by the restraint structure 140 on the balloon 120 when the balloon 120 is inflated can be prevented.

[0081] Figure 5 is a schematic diagram of the wire connection of the restraint structure of the balloon catheter assembly of some embodiments of the present specification.

[0082] In some embodiments, the restraint structure 140 can be a memory alloy stent formed by integral cutting (such as laser integral cutting), and exemplary memory alloys can include nickel-titanium alloy, copper-nickel alloy, etc. For reference Figure 2 and Figure 5In some embodiments, the memory metal stent can include a plurality of wires, which can be classified into a connecting rod 1411 at the proximal end 141, a connecting rod 1421 at the distal end 142, a connecting rod 1431 at the action section 143, and an S-shaped structure connected with the connecting rod 1411 at the proximal end, the connecting rod 1421 at the distal end, and the connecting rod 1431 at the action section.

[0083] In some embodiments, a plurality of S-shaped structures can be arranged in an array along the arrangement direction of the balloon 120. Each column constitutes a wave-shaped constraint ring, and each constraint ring can be connected with at least one of the connecting rod 1411 at the proximal end, the connecting rod 1421 at the distal end, and the connecting rod 1431 at the action section. In some embodiments, in order to make the constraint structure 140 have substantially the same constraint force on the balloon 120 at different positions, the plurality of constraint rings can have the same spacing.

[0084] The constraint ring formed by the S-shaped structure can expand or contract with the state of the balloon 120, thereby limiting the expansion size and expansion shape of the balloon 120, in other words, the constraint ring formed by the S-shaped structure can cooperate with the longitudinal and radial expansion of the balloon 120 during the expansion process, and can keep the balloon 120 at the desired position during the expansion process.

[0085] In some embodiments, the total length of the constraint ring formed by the S-shaped structure after the balloon 120 expands can be greater than the maximum circumference of the balloon 120 after expansion. In some embodiments, in order to make the constraint ring have substantially the same constraint effect on the balloon 120, different constraint rings can be provided to have substantially the same contraction performance and circumference.

[0086] In some embodiments, at least one connecting intersection 1432 of each wire in the memory metal stent can form at least one circular arc buffer section. Specifically, the connecting intersection of any two wires in the memory metal stent forms a fillet or circular arc structure when cut, thereby avoiding the connecting intersection 1432 of each wire from being too concentrated in stress and causing the stent to break during expansion or contraction, thereby causing serious harm to the patient. In addition, by setting the connecting intersection 1432 as a fillet or circular arc structure, compared with a sharp angle or a right angle, the sharp angle structure can also prevent the force on the balloon 120 from being too sharp and damaging the balloon 120.

[0087] Referring to Figure 5In some embodiments, the rounded or arc-shaped structure formed by the connecting intersection of the metal wires when cut can be a circular arc with a radius of R1, which can be concave or convex relative to the connecting intersection. In some embodiments, the radius R1 corresponding to the rounded or arc-shaped structure can be between 0.5mm and 1mm, wherein the radius R1 and the arc length corresponding to the rounded or arc-shaped structure at each connecting intersection can be the same or different.

[0088] In some embodiments, the connecting proximal end 141 of the constraint structure 140 can be connected at the proximal end of the adhesive layer 135 (e.g., the second connecting portion 135-2) or the proximal end 1201 of the balloon. In some embodiments, by connecting the connecting proximal end 141 of the constraint structure 140 at the proximal end of the adhesive layer 135 (e.g., the second connecting portion 135-2), compared to connecting at the proximal end 1201 of the balloon, the connecting proximal end 141 of the constraint structure 140 can be prevented from expanding with the balloon, thereby achieving better limiting effect, and compared to connecting at the proximal end 1201 of the balloon, the overall outer diameter size of the catheter 130 can also be reduced to some extent.

[0089] The connecting distal end 142 of the constraint structure 140 can be connected with the distal end of the balloon 120, wherein the distal end of the balloon 120 can refer to the position of the balloon 120 farthest from the catheter seat 110. In some embodiments, the connecting distal end 142 of the constraint structure 140 can be fixedly connected with the distal end of the balloon 120 by adhesion or clamping, and similarly, the connecting proximal end 141 of the constraint structure 140 can also be fixedly connected with the proximal end of the adhesive layer 135 or the proximal end 1201 of the balloon by adhesion or clamping.

[0090] Figure 6 is a schematic view of the cross section of the metal wire of the constraint structure of the balloon catheter assembly of some embodiments of the present specification.

[0091] Referring to Figure 6 In some embodiments, the cross section of the metal wire in the constraint structure 140 can be one or more of a trapezoidal shape (as shown in 6A), a triangular shape (as shown in 6B), or a circular shape (as shown in 6C), which can refer to the cross section perpendicular to the length extension direction of the metal wire. In some embodiments, the radial dimension of the metal wire in the constraint structure 140 can be between 0.1mm and 0.2mm. It should be noted that the above description of the shape of the cross section of the metal wire is only exemplary, and in the embodiments of the present specification, the cross section shape of the metal wire can be, but is not limited to, the above-mentioned trapezoidal shape, triangular shape, and circular shape. For example, in some embodiments, the cross section shape of the metal wire can also be a rectangular shape.

[0092] In some embodiments, the outer surface of the balloon 120 and the outer surface of the constraint structure 140 can be used for applying a drug. In some embodiments, the drug can be applied to the outer surface of the balloon 120 and / or the outer surface of the constraint structure 140 in a one-time application manner. In other embodiments, openings can be formed between two adjacent balloons 120 to communicate with a drug-carrying cavity inside the catheter 130, and the drug can be delivered through the drug-carrying cavity in the catheter 130 and then delivered to the outer surface of the balloon 120 and / or the outer surface of the constraint structure 140 through the openings formed between the two adjacent balloons, or directly dissolved in the blood vessel cavity, wherein the outer surface of the constraint structure 140 can refer to the side away from the balloon 120. In some embodiments, the balloon catheter assembly 100 can further include a developing assembly, and the drug can be accurately delivered to the target position to be treated according to the internal image of the blood vessel obtained by the developing assembly, so as to improve the treatment effect of the drug on the inner wall of the blood vessel to a certain extent.

[0093] In some embodiments, in order to increase the area of the drug applied to the outer surface of the constraint structure 140, a wire with a trapezoidal cross section can be selected to form the constraint structure 140, and the lower base 610 of the wire with a trapezoidal cross section can be directed outward (i.e., away from the balloon 120), or a wire with a triangular cross section can be selected, and the longest side (e.g., 621) of the three sides can be directed outward (i.e., away from the balloon 120). Considering that when the cross-sectional shape of the wire is triangular, the force exerted by the side of the wire towards the balloon 120 can be relatively sharp (i.e., the force per unit area is relatively large), therefore, in order to avoid damage to the balloon during the expansion process due to the force exerted by the wire being too sharp, in some embodiments, the area of the side of the wire towards the balloon 120 and in contact with the balloon 120 can be increased, for example, the angle of the corner of the triangle towards the balloon 120 can be increased to be an obtuse angle greater than 120°, thereby not only increasing the contact area of the wire with the balloon 120 during the expansion of the balloon, reducing the force per unit area of the wire acting on the balloon, but also increasing the area of the side 620 of the wire away from the balloon 120, thereby increasing the area available for applying the drug. In some embodiments, the outer surface of the constraint structure can be provided with a drug coating. In some embodiments, the drug coating can only be provided on the outer surface of the balloon and not on the outer surface of the constraint structure, because if the drug coating is provided on the outer surface of the constraint structure, the metal wire part of the constraint structure will form a concave part relative to the balloon during the expansion of the balloon, which cannot contact the inner wall of the blood vessel, thereby failing to release the drug.

[0094] In some embodiments, the drug coating on the outer surface of the constraining structure 140 can comprise at least one other active drug in addition to the macrolide drug, such as at least one selected from the group consisting of paclitaxel and its derivatives, rapamycin and its derivatives, phosphodiesterase inhibitors, thrombin inhibitors, thymidine kinase inhibitors, antibiotics, adenosine. It should be noted that the above drugs are merely exemplary, and the drug coating on the outer surface of the constraining structure 140 in the embodiments of the present specification can be, but is not limited to, the aforementioned exemplary drugs.

[0095] The foregoing detailed description has set forth various embodiments of the devices and / or methods via the use of specific terminology. As such, the description herein is not intended to limit the devices and / or methods in any way so long as the description does not read on pre-existing prior art. It is intended to cover any and all modifications and variations of the various embodiments including their equivalents. It is intended to include all alternatives, modifications and equivalents for the features under claims. It is submitted with the understanding that the use of specific nomenclature is merely intended to add clarity and better communicate the underlying principles of the devices and / or methods.

[0096] In addition, certain features, structures, or characteristics of the devices and / or methods can be used in suitable combination. Therefore, it is to be understood that even though a number of features and aspects of the devices and / or methods have been identified herein, the present devices and / or methods can include all features that would be apparent to one of ordinary skill in the art upon examining the disclosure, and that are within the scope of the devices and / or methods.

[0097] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Pronouns in the masculine form include the feminine form, and vice versa, except as otherwise expressly specifically herein. Singular referents exhibit the same limitations. It is further noted that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Pronouns in the masculine form include the feminine form, and vice versa, except as otherwise expressly specifically herein. Singular referents exhibit the same limitations.

[0098] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0099] For each patent, patent application, patent application publication, and other material, such as articles, books, specifications, publications, and documents, referenced in this specification, the entire contents of which are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this specification, as well as documents that limit the broadest scope of the claims in this specification (currently or subsequently appended to this specification). It should be noted that in the event of any inconsistency or conflict between the descriptions, definitions, and / or terminology used in the supplementary materials to this specification and the content of this specification, the descriptions, definitions, and / or terminology used in this specification shall prevail.

[0100] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and are considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A constraint structure for a balloon catheter assembly, characterized by, The constraint structure comprises a connection proximal end, a connection distal end, and an action section connected between the connection proximal end and the connection distal end; the number of connection rods of the action section is greater than the number of connection rods of the connection proximal end and / or the connection distal end; the constraint structure is processed by electrolytic polishing; the width of at least one connection rod of the connection proximal end and / or the connection distal end is 1.5 to 4 times the width of at least one connection rod of the action section.

2. The restraining structure of claim 1, wherein, The constraint structure is wrapped outside the balloon and is a memory alloy stent formed by integral cutting.

3. The restraint structure of claim 1, wherein, The width of at least one connection rod of the connection proximal end and / or the connection distal end is 2 to 4 times the width of at least one connection rod of the action section.

4. The restraining structure of claim 1, wherein, The outer surface of the constraint structure is provided with a drug coating.

5. The restraint structure of claim 2, wherein, The outer surface of the balloon is provided with a drug coating.

6. The restraint structure of claim 1, wherein, The constraint structure is a memory alloy stent formed by integral cutting, and at least one circular arc buffer section is formed at at least one connection intersection of each wire in the memory alloy stent.

7. The restraint structure of claim 2, wherein, The balloon is a single-layer balloon made of nylon, nylon copolymer and / or polyterephthalic plastic, or a double-layer balloon with a polyterephthalic plastic inner layer and a nylon outer layer.

8. The restraint structure of claim 6, wherein, The cross section of each wire in the constraint structure is circular, trapezoidal and / or triangular.

9. A balloon catheter assembly comprising the constraint structure according to claim 1.

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