Delivery sheath and delivery system

Abstract

The present application provides a delivery sheath and a delivery system. The delivery sheath includes a tube body and at least one reinforcing rib. The tube body includes a main section and a bendable section in the axial direction. The tube body includes an inner lining, a reinforcing layer and an outer layer arranged from the inside to the outside in the radial direction, wherein the reinforcing layer is a combination of one or more of a spring coil, a metal braided mesh or a cut sea wave tube. At least one reinforcing rib is arranged in the tube body along the axial direction of the tube body, and at least one reinforcing rib is configured on the curved outer side of at least part of the bendable section, or is configured to be symmetrically distributed with the axial cross section of at least part of the tube body as a symmetry plane and relatively close to the curved outer side. By improving the structure of the delivery sheath, the support and anti-torsion deflection performance of the delivery sheath are improved, thereby better delivery is performed.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to a delivery sheath and a delivery system. Background Art

[0002] Interventional therapy, characterized by its non-invasive nature, minimal trauma, rapid recovery, and excellent efficacy, has gradually become the mainstream treatment for structural heart disease. Typically, after puncturing the femoral artery, carotid artery, or femoral vein, a sheath or catheter is inserted through the blood vessel to establish a delivery channel from outside the body to inside the body. Implantable devices (such as occluders, clips, valve repair devices, valve replacement devices, radiofrequency ablation devices, stents, balloons, vascular plugs, and filters) are delivered through this channel to the lesion for placement or retrieval.

[0003] To adapt to the complex and diverse nature of human blood vessels and organs and accurately position implantable devices at diseased organs, a delivery system typically uses at least two layers of tubing. The outer delivery sheath typically has an adjustable or shaped distal end that provides a path for the inner catheter, which pushes and twists within the lumen of the delivery sheath. The delivery system achieves precise positioning of the implantable device through the interaction of these two layers.

[0004] This coordinated operation requires multiple adjustments to both the inner and outer tubes during operation of the delivery system. This includes twisting the inner catheter within a delivery sheath that has already been bent or shaped. During this process, the curved delivery sheath is easily affected by the movement of the inner catheter. When the inner catheter is twisted, the delivery sheath cannot maintain its originally adjusted desired position. The distal end of the curved delivery sheath will twist or deflect in the direction of the inner catheter's twisting, making it difficult for the inner catheter's distal end to point to the target position. Furthermore, the delivery sheath may be subjected to forces in the direction of the inner catheter's twisting, causing it to twist and deform, leading to delivery sheath failure.

[0005] In order to ensure that the distal end of the inner catheter points accurately, it is often necessary to perform compensatory twisting on the delivery sheath while twisting the inner catheter. That is, the inner and outer tubes need to be twisted, pushed, and pulled multiple times, and the distal end of the inner catheter needs to be repeatedly judged through images to ensure that the distal end of the inner catheter accurately points to the target position.

[0006] The existence of this problem will require the surgeon to continuously adjust the inner and outer tubes of the delivery system multiple times during the operation, thereby prolonging the operation time and increasing the difficulty of the operation. Summary of the Invention

[0007] The purpose of this application is to provide a delivery sheath and a delivery system to address the above-mentioned defects of the prior art, and to overcome the above-mentioned problems by being used in conjunction with an inner layer catheter.

[0008] The delivery sheath provided in the present application includes a tube body and at least one reinforcing rib; the tube body includes a main section and a bendable section in the axial direction; the tube body includes an inner lining, a reinforcing layer and an outer layer arranged from the inside to the outside in the radial direction, wherein the reinforcing layer is one or a combination of several of a spring coil, a metal braided mesh or a cut sea wave tube; the at least one reinforcing rib is arranged in the tube body along the axial direction of the tube body, and the at least one reinforcing rib is configured on the curved outside of at least part of the bendable section, or is configured to be symmetrically distributed with the axial cross-section of at least part of the tube body as the symmetry plane and relatively close to the curved outside.

[0009] The reinforcing ribs penetrate the entire tube body along the axial direction of the tube body, or are only arranged in a part of the tube body.

[0010] The reinforcing ribs are located between the inner lining of the pipe body and the reinforcing layer, or between the reinforcing layer and the outer layer, or the reinforcing ribs and the reinforcing layer form a composite integral structure.

[0011] The reinforcing rib is made of at least one round wire or flat wire; the radial cross-section of the round wire is circular, and the wire diameter is 0.05mm-1.0mm; the radial cross-section of the flat wire is rectangular, the long side of the rectangle is 0.05mm-3.0mm, and the short side is 0.05mm-0.2mm, wherein the short side of the rectangle extends along the radial direction of the tube body.

[0012] The reinforcing ribs are only arranged on the bendable section, and are made of two or more round wires or flat wires in parallel combination, or a parallel combination of round wires and flat wires, and the distal and proximal ends of the reinforcing ribs are respectively connected to fixing rings.

[0013] The reinforcing ribs are special-shaped ribs formed by connecting multiple sections of metal wires of different shapes in series.

[0014] The special-shaped ribs are formed by alternatingly connecting at least two segments with different radial cross-sectional shapes, and the segments with the same cross-sectional shape have uniform lengths or are arranged in increasing order from far to near to the proximal end of the bendable segment.

[0015] The reinforcing ribs are cut from a metal hypotube, and continuous reinforcing ribs are formed on the outer side of the bend of at least part of the bendable section.

[0016] The reinforcing rib includes a main body, the radial cross-section of the main body is a rectangle, the long side of the rectangle is 0.05mm-3.0mm, and the short side of the rectangle is 0.05mm-0.2mm, wherein the short side of the rectangle extends radially along the tube body; the overall length of the main body is equal to the length of the bendable section.

[0017] Wherein, both ends of the reinforcing rib are respectively a fixing ring cut and formed integrally with the main body, and the axial length of each fixing ring is 0.5mm-2mm.

[0018] The reinforcing ribs are formed by continuous cutting of metal pipes, and there are two reinforcing ribs. The two reinforcing ribs are continuously and symmetrically arranged with at least a portion of the axial cross section of the pipe body as a symmetry plane.

[0019] The central angle α formed by each part of the two reinforcing ribs on the radial cross section is 120°, or the central angle α formed by each part of the two reinforcing ribs on the radial cross section increases continuously and smoothly from 120° to 165° from the distal end to the proximal end.

[0020] The reinforcing rib is formed by cutting a metal pipe into discontinuous segments, and the reinforcing rib includes at least two rib segments, which are spaced apart in the axial direction of the pipe body.

[0021] The angle β at which one of the rib segments rotates relative to the other in the circumferential direction is 0°, 90°, 120° or 180°.

[0022] The length of each rib segment is 0.5 mm to 10 mm, and the length of the rib segment increases from far to near to the proximal end of the bendable segment.

[0023] The present application also provides a delivery system, comprising a delivery sheath of the aforementioned structure, and an inner layer catheter accommodated in the inner cavity of the delivery sheath.

[0024] Compared with the prior art, the delivery sheath and delivery system provided by this application have at least the following advantages:

[0025] By improving the structure of the delivery sheath, the delivery sheath is provided with a tube body and at least one reinforcing rib arranged along the axial direction. After the delivery sheath is implanted in the designated position, the presence of the reinforcing rib enhances the rigidity of the delivery sheath against torsion or deflection. Therefore, the provision of the reinforcing rib can well enhance the support and anti-torsion deflection performance of the delivery sheath. Even when the inner catheter is twisted in the delivery sheath, the delivery sheath will not or will only slightly deform and deflect as the inner catheter twists, and can relatively stably maintain the original direction, so that the delivery sheath can continue to relatively stably maintain the originally adjusted position without the need for compensatory adjustment, thereby achieving effective, rapid and accurate adjustment of the delivery system.

[0026] Figures and Description of Figures

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate some embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 Schematic diagram of the overall structure of the delivery sheath and delivery system in some embodiments;

[0030] Figure 2 is an overall schematic diagram of a delivery sheath in some embodiments;

[0031] Figure 3 Schematic diagram of the structure of the delivery sheath in some embodiments;

[0032] Figure 4 is a schematic diagram of a radial cross-section of a pre-shaped delivery sheath in some embodiments;

[0033] Figure 5 Schematic diagram of the structure of a delivery sheath with a bending adjustment component in some embodiments;

[0034] Figure 6 Schematic diagram of a radial cross-section of a delivery sheath having a bending adjustment assembly in some embodiments;

[0035] Figure 7 Schematic diagram of the overall structure of a delivery sheath with a single reinforcing rib (with the outer layer removed) in some embodiments;

[0036] Figure 8 Schematic diagram of the structure of a single reinforcing rib in some embodiments;

[0037] Figure 9 Schematic diagram of the structure of a single special-shaped reinforcement rib in some embodiments;

[0038] Figure 10 Schematic diagram of the structure of a single reinforcing rib in some embodiments;

[0039] Figure 11 Schematic diagram of the structure of a single reinforcing rib in some embodiments;

[0040] Figure 12 is a schematic diagram of a radial cross-section of a delivery sheath having two reinforcing ribs in some embodiments;

[0041] Figure 13 Schematic diagram of the structure of two reinforcing ribs in some embodiments;

[0042] Figure 14 Schematic diagram of the structure of two reinforcing ribs in some embodiments;

[0043] Figure 15 Schematic diagram of the structure of smooth transition between two reinforcing ribs in some embodiments;

[0044] Figure 16 Schematic diagram of the structure of discontinuous reinforcement ribs in some embodiments;

[0045] Figure 17 Schematic diagram of the structure of discontinuous reinforcement ribs in some embodiments;

[0046] Figure 18 Schematic diagram of the angles between discontinuous reinforcing rib segments in some embodiments; DETAILED DESCRIPTION

[0047] For ease of description, here are the following definitions: In the field of interventional medical devices, the proximal end refers to the end closest to the operator, and the distal end refers to the end farther from the operator. A radial cross section is perpendicular to the central axis, and an axial cross section is parallel to the central axis. The delivery sheath's bending direction is P. Along this direction, the smaller bend radius is the inner bend, and the larger bend radius is the outer bend. The delivery sheath's deflection direction is Q.

[0048] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on certain embodiments of this application without making creative efforts are within the scope of protection of this application.

[0049] References throughout this specification to "one embodiment," "an embodiment," "in another embodiment," or "in certain embodiments" mean that at least one embodiment includes the particular referenced elements, structures, or features described in connection with that embodiment. Thus, appearances of the phrases "in one embodiment," "in an embodiment," "in another embodiment," or "in certain embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular elements, structures, or features may be combined in any suitable manner in one or more embodiments.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0051] The present application provides a delivery system 1, comprising a delivery sheath 10 and an inner catheter 20 accommodated in the inner cavity of the delivery sheath 10, for establishing a channel from the outside world to human blood vessels to target organs for the delivery of diagnostic and therapeutic instruments, such as Figure 1 shown.

[0052] During the operation, when the outer layer of the delivery sheath 10 is formed into a spatial bend and the inner layer catheter 20 is also accommodated in the inner cavity of the delivery sheath 10, if the anti-twisting and anti-deflection performance of the delivery sheath 10 is improved, it can effectively improve the deformation of the delivery sheath 10 and the distal directional deviation caused by the twisting of the inner layer catheter 20; thereby, the delivery sheath 10 can maintain its original direction relatively stably, and the inner layer catheter 20 can be well adjusted to the expected appropriate position without the need for compensatory adjustment.

[0053] The purpose of this application is to improve the anti-torsion and anti-deflection performance of the delivery sheath 10. The specific technical solution is introduced as follows.

[0054] In some embodiments, combined Figure 2-6 As shown, a delivery sheath 10 includes a tube body 12 and at least one reinforcing rib 14. The tube body 12 includes a bendable section 121 and a main section 123 in the axial direction; the tube body 12 includes an inner lining 122, a reinforcing layer 124 and an outer layer 126 arranged from the inside to the outside in the radial direction.

[0055] In some embodiments, in order to facilitate bending and simplify operation, the bendable section 121 of the tube body 12 may be pre-shaped so as to maintain a bent state.

[0056] In some embodiments, in order to flexibly adjust the delivery sheath 10, the delivery sheath 10 may further include a bending adjustment component 16, which can control the bending of the bendable section 121. Specifically, the bending adjustment component 16 includes an anchor ring 162, a bending adjustment wire 164, and a bending adjustment wire channel 166. Figure 5-6 shown.

[0057] In some embodiments, the inner liner 122 is made of PTFE (polytetrafluoroethylene) and extends through the flexible section 121 and the main body section 123 of the delivery sheath 10. The reinforcement layer 124 is a spring coil, a metal braid, or a cut hypotube, or a combination thereof, and is made of a metal such as stainless steel, tungsten, nickel titanium, etc. The outer layer 126 is made of a thermoplastic elastomer, such as Pebax (block polyetheramide resin) or TPU (thermoplastic polyurethanes), and is heat-sealably coated on the outside of the reinforcement layer 124.

[0058] It should be emphasized that the reinforcement layer 124 of the entire tube body 12 can have the same structure in the bendable section 121 and the main section 123, or it can use different structures in the bendable section 121 and the main section 123. The outer layer 126 of the entire tube body 12 can have the same structure in the bendable section 121 and the main section 123, or it can use different structures in the bendable section 121 and the main section 123. For example, the reinforcement layer 124 can use a cut hypotube in the portion corresponding to the bendable section 121 and a woven metal mesh in the portion corresponding to the main section 123. These two different structures form the reinforcement layer 124. The outer layer 126 can use a softer Pebax or TPU material, such as 25D Pebax or 35D Pebax, in the portion corresponding to the bendable section 121, and a harder Pebax or TPU material, such as 72D Pebax, in the portion corresponding to the main section 123. These two materials of different hardness are combined to form the outer layer 126.

[0059] In some embodiments, in order to enhance the anti-torsion and anti-deflection performance of the delivery sheath 10, at least one reinforcing rib 14 is arranged in the tube body 12 along the axial direction of the tube body 12, and at least one reinforcing rib 14 is configured on the outer side of the bend of at least part of the bendable section 121, that is, at a position symmetrically distributed with the bending adjustment wire 164 on the radial cross section. Because of the presence of the reinforcing rib 14, the performance of the tube body 12 will change from isotropic to anisotropic. The presence of the reinforcing rib 14 in the tube body 12 enhances its rigidity against torsion or deflection, because if the tube body 12 is to be twisted or deflected, the reinforcing rib 14 must be twisted or deflected first. In other words, the same state change requires greater force, and thus the anti-torsion and anti-deflection performance of the delivery sheath 10 can be greatly improved.

[0060] In some embodiments, in order to enhance the anti-torsion and anti-deflection performance of the delivery sheath 10, at least one reinforcing rib 14 is symmetrically distributed and relatively close to the outer side of the bend with the axial cross-section of at least part of the tube body 12 as the symmetry plane, such as the axial cross-section O where the bending wire 164 is located.

[0061] It is particularly noted that when the tube body 12 bends along the reinforcing rib 14 or the opposite side of the reinforcing rib 14, since the bending direction of the reinforcing rib 14 is consistent with the bending direction of the tube body 12, the bending direction of the tube body 12 will be more stable and less likely to cause twisting and deflection.

[0062] In some embodiments, the reinforcing ribs 14 may extend through the entire delivery sheath 10 along the axial direction of the tubular body 12, or may be disposed only in a portion of the tubular body 12. Specifically, the reinforcing ribs 14 may extend to any position of the main body section 123, or even to the proximal end of the tubular body 12. In other words, the presence of the reinforcing ribs 14 throughout the tubular body 12 of the delivery sheath 10 helps prevent the entire tubular body 12 from torsional deformation, thereby improving the anti-torsion and anti-deflection performance of the entire tubular body 12.

[0063] Furthermore, in order to make the bending direction of the delivery sheath 10 more flexible and provide more room for bending adjustment, the reinforcing ribs 14 can be arranged only in the bendable section 121, with the proximal end of the reinforcing ribs 14 extending at least to the proximal end of the bendable section 121, or even arranged only in the rear half of the bendable section 121 (the end adjacent to the main section 123). This is because in the curved body 12 of the delivery sheath 10, when the inner layer catheter 20 twists, the first part of the delivery sheath 10 to deflect is the rear half of the bendable section 121, followed by the front half of the bendable section 121. Therefore, arranging the reinforcing ribs 14 only in the rear half of the bendable section 121 of the delivery sheath 10 is also an effective arrangement to prevent torsional deflection of the delivery sheath 10.

[0064] In some embodiments, at least one reinforcing rib 14 can be located between the inner lining 122 and the reinforcing layer 124, between the reinforcing layer 124 and the outer layer 126, or can be integrated with the reinforcing layer 124 to form a composite structure. When the reinforcing rib 14 is located between the inner lining 122 and the reinforcing layer 124, the reinforcing layer 124 can stabilize and secure the reinforcing rib 14, thereby facilitating its positioning and securement. When the reinforcing rib 14 is located between the reinforcing layer 124 and the outer layer 126, a wider range of positions are available for the reinforcing rib 14. When the reinforcing rib 14 and the reinforcing layer 124 form a composite structure, this saves space in the tube body 12 while ensuring the positioning and stability of the reinforcing rib 14, resulting in the best overall performance.

[0065] In some embodiments, the reinforcing rib 14 is optionally made of stainless steel, nickel titanium, or other metal materials. The reinforcing rib 14 is made of a single round wire with a circular radial cross-section, preferably with a wire diameter of 0.05 mm to 1.0 mm, and relies on the rigidity of the round wire itself to improve the torsional resistance of the tube 12.

[0066] In some embodiments, combined Figure 7 As shown, the reinforcing ribs 14 can also be made of a flat wire with a rectangular radial cross-section. The long side of the rectangle is preferably 0.05 mm to 3.0 mm, and the short side of the rectangle is preferably 0.05 mm to 0.2 mm, where the short side of the rectangle extends radially along the tube body 12. The different side lengths of the flat wire provide anisotropic stiffness, which better meets the anisotropic bending and anti-deflection requirements of the tube body 12.

[0067] It is particularly important to emphasize that the rectangular cross-section reinforcement ribs 14 provide rigidity in two different directions. The short side of the reinforcement ribs 14 aligns with the bending direction, so a smaller short side width helps reduce the impact of the reinforcement ribs 14 on the bending performance of the tube body 12. The long side is perpendicular to the bending direction, and a larger long side width helps the delivery sheath 10 resist twisting and deflection perpendicular to the bending direction when the inner layer catheter 20 is twisted.

[0068] In some embodiments, the distal and proximal ends of the reinforcing rib 14 are connected and fixed to the tubular body 12 of the delivery sheath 10 via a fixing ring 18 or other similar structure. Alternatively, the reinforcing rib 14 may be fixed solely by hot-melt fixation of the outer layer 126 without an additional fixing structure. If the distal end of the reinforcing rib 14 is fixed to the distal end of the tubular body 12 via the fixing ring 18, in order to avoid affecting the length of the distal straight section of the tubular body 12 or the length of the bendable section 121, the fixing ring 18 connecting the distal end of the reinforcing rib 14 is arranged as close as possible to the anchor ring 162, or overlapped in the same position, or even directly fixed to the anchor ring 162 by welding or other means, to reduce the influence of the fixing ring 18 on the bendable section 121 of the tubular body 12.

[0069] In some embodiments, the reinforcing rib 14 is disposed only on the bendable section 121 and is formed by freely combining multiple wires of different shapes, such as two or more round wires, two or more flat wires, or a combination of round and flat wires. The distal and proximal ends of the reinforcing rib 14 are respectively connected to the fixing ring 18. The reinforcing rib 14, formed from the combined wires, exhibits a more pronounced anisotropic stiffness.

[0070] In some embodiments, combined Figure 8As shown, a stainless steel wire braided mesh tube is used as the reinforcement layer 124, and the reinforcement ribs 14 are only arranged between the inner lining 122 and the reinforcement layer 124 of the bendable section 121 of the tube body 12. Two stainless steel round wires 140 are used in parallel as the reinforcement ribs 14. The distal and proximal ends of the two parallel stainless steel round wires 140 are respectively welded to two stainless steel fixing rings 18. The wire diameter of the stainless steel round wires 140 is preferably 0.05mm-1.0mm. The rigidity of the reinforcement ribs 14 composed of the two parallel stainless steel round wires 140 is not easy to twist and deflect, which can improve the rigidity of the reinforcement ribs 14 in the vertical bending direction. The higher rigidity in this direction is more conducive to improving the anti-twisting and anti-deflection performance of the tube body 12, making the delivery sheath 10 less likely to twist and deflect.

[0071] In some embodiments, the reinforcing rib 14 can even be a special-shaped rib formed by combining multiple sections of metal wires of different shapes in series. Among them, the overall shape of at least one reinforcing rib 14 is set to be special-shaped, and is formed by alternating connection of at least two segments with different radial cross-sectional shapes. The segments can be connected by welding, and the cross-section of the segments is circular, rectangular, polygonal, etc. The length of each segment can be set to be uniform and equal, or it can be set to a length with a certain regular arrangement and combination. Among them, different cross-sections have different bending stiffness characteristics. For example, the circular cross-section is isotropic, and the rectangular cross-section has two mutually perpendicular bending stiffnesses along the direction of the long side and the short side. The bending stiffness of the entire reinforcing rib 14 can be adjusted by combining segments with different cross-sections to balance the bending and anti-torsion and anti-deflection performance of the tube body 12.

[0072] Specifically, combined Figure 9 As shown, for example, segments with circular and rectangular cross sections are selected to be connected at intervals to form the special-shaped reinforcement rib 14. Among them, the lengths of the circular segment 142 and the rectangular segment 144 are respectively l i 、l j , the value range is 0.5mm-10mm. i 、l j The values ​​of can be the same or different. i With l i+1 The length of the rectangular segment l j than l (j+1) The length is short, for example l j1 than l j2 1 mm shorter, that is, they are arranged in increasing order from far to near to the proximal end of the bendable section 121 .

[0073] Because, it is understandable that the rectangular segment 144 can have anisotropic rigidity, and the rigidity of the proximal end of the bendable section 121 of the delivery sheath 10 has a greater impact on the anti-torsion and anti-deflection performance of the delivery sheath 10, the rectangular segment 144 with a longer proximal end of the bendable section 121 is more conducive to improving the anti-torsion and anti-deflection performance of the delivery tube body 12. At the same time, the thickness of the rectangular segment 144 in the bending direction of the delivery sheath 10 is smaller than the thickness in the torsional and deflection direction, thereby maintaining bendability while enhancing anti-torsion and deflection performance.

[0074] It should be noted that due to the presence of the reinforcing ribs 14, when the inner catheter 20 undergoes twisting and deflection within the delivery sheath 10, the reinforcing ribs 14 themselves are not easily twisted or deflected, thereby also preventing the delivery sheath 10 from twisting and deflecting. Ribs 14 of appropriate material and size can effectively balance the rigidity and bending compliance of the delivery sheath 10, thereby achieving the goal of reducing deformation or twisting of the delivery sheath 10 with the inner catheter 20 without affecting its performance requirements.

[0075] In some embodiments, the reinforcement rib 14 is cut from a metal sea wave tube, which itself has a thin-walled and thick-walled structural feature. By cutting, a continuous reinforcement rib body 140 can be easily obtained on the curved outer side of at least part of the bendable section 121. In addition, the two ends of the metal sea wave tube are kept intact without being cut, and an integrally cut reinforcement rib 14 structure can be obtained.

[0076] Specifically, combined Figure 10 As shown, the cutting reinforcement rib 14 is made of a metal such as stainless steel or nickel-titanium. After cutting, the reinforcement rib 14 includes a main body 140. The main body 140 has a rectangular cross-section with a long side of 0.05 mm to 3.0 mm and a short side of 0.05 mm to 0.2 mm. The short side of the rectangle extends radially along the tube body 12. The length of the main body 140 corresponds to the length of the flexible section 121 of the delivery sheath 10.

[0077] In some embodiments, combined Figure 10 As shown, each end of the rib body 140 retains a single-piece, cut-to-size, complete tubing with an axial length of 0.5mm-2mm, serving as a retaining ring 18 for securing the rib 14 to the delivery sheath 10. Axially, the retaining rings 18 at each end of the body 140 are located at the ends of the bendable section 121 of the delivery sheath 10. Radially, the retaining rings 18 are positioned between the liner 122 and the reinforcing layer 124, which is sleeved over the cut rib 14. The metal braided mesh reinforcing layer 124 secures the rib 14.

[0078] That is to say, when the delivery sheath 10 is bent, on the one hand, the reinforcement layer 124 made of the metal braided mesh can provide support performance, improve the bending strength of the delivery sheath 10, and prevent the delivery sheath 10 from collapsing and deforming due to bending. On the other hand, the integrally cut and formed reinforcement ribs 14 can bend as the tube body 12 of the delivery sheath 10 bends, and will not easily shift under the fixation of the reinforcement layer 124. When the inner layer catheter 20 in the delivery sheath 10 is twisted, the rigidity of the integrally cut and formed metal reinforcement ribs 14 in the direction perpendicular to the bending direction makes it difficult for the delivery sheath 10 to deflect, thereby enhancing its anti-torsion and anti-deflection functions.

[0079] In some embodiments, the delivery sheath 10 radially comprises, from inside to outside, an inner liner 122, a reinforcement layer 124 made of cut hypotube, and an outer layer 126. The cut hypotube can serve both as the reinforcing ribs 14 and the reinforcing layer 124, thereby forming a composite, integrated structure with the reinforcing ribs 14 and the reinforcing layer 124. The cut lines on the reinforcing layer 124 can reduce its hardness, improve its compliance, and provide a certain degree of support.

[0080] Specifically, combined Figure 11 As shown, the metal hypotube is cut and retained to form a single reinforcing rib 14 on the opposite side of the delivery sheath 10 (i.e., on the outer side of the bend), thereby providing the cut metal hypotube with both support and torsion and deflection resistance. In the axial direction, the entire tube body 12 utilizes the cut hypotube as a reinforcement layer 124, with the single reinforcing rib 14 continuously running through the entire cut hypotube, improving the torsion and deflection resistance of the entire tube body 12.

[0081] It is important to emphasize that this integrated structure ensures that the delivery sheath 10 body 12 can bend without easily collapsing when the delivery sheath 10 is bent. When the inner catheter 20 is twisted, the single reinforcing rib 14 on the cutting pattern effectively resists torsional deflection, preventing the delivery sheath 10 from deflecting or twisting.

[0082] In some embodiments, to reduce costs, a single reinforcing rib 14 may be continuously inserted through only the bendable section 121 of the tube body 12, while the main section 123 may be provided with a metal braided mesh tube 124. Combining these two structures preserves the bending performance of the bendable section 121 of the tube body 12 while improving its anti-torsion and anti-deflection performance.

[0083] In some embodiments, the basic structure of the delivery sheath 10 is substantially the same as the aforementioned structure, with the biggest difference being the change in the number and relative position of the reinforcing ribs 14. Figure 12As shown, at least two reinforcing ribs 14 are arranged on the delivery sheath 10 , and the two reinforcing ribs 14 are continuously and symmetrically arranged with the axial section O of at least part of the tube body 12 , that is, the axial section O where the bending wire 164 is located, as the symmetry plane.

[0084] It is particularly noted that the central angle α formed by the two reinforcing ribs 14 on the same radial cross-section can be any angle between 0° and 180°. Among them, when the angle of the central angle α between the two reinforcing ribs 14 is 0°, it is equivalent to the effect of a single reinforcing rib. When the angle of the central angle α between the two reinforcing ribs 14 is not 0°, the two reinforcing ribs 14 are symmetrically located on both sides of the axial cross-section O of the tube body 12 where the bending wire 164 or the bending direction is located as the symmetry plane. The reason for this arrangement is that when the inner layer catheter 20 acts on the outer layer of the delivery sheath 10 torsionally, causing the delivery sheath 10 to have a tendency to deform, the symmetrical reinforcing ribs 14 on both sides have the ability to resist deformation, which can prevent the tube body 12 from deforming and effectively prevent the tube body 12 from deflecting.

[0085] In some embodiments, to maximize the effectiveness of the reinforcing ribs 14 while not affecting the performance of the delivery sheath 10, the lengths of the two reinforcing ribs 14 are set to be equal to the length of the bendable section 121 of the delivery sheath 10. Each reinforcing rib 14 can be made of stainless steel round wire, stainless steel flat wire, or a combination of multiple stainless steel wires arranged in parallel, or even a twisted combination of multiple strands of stainless steel wire.

[0086] It should be noted that ribs 14 with circular radial cross-sections have isotropic rigidity, while ribs 14 with rectangular radial cross-sections have anisotropic rigidity, with greater rigidity in the direction of thickness. When rectangular ribs 14 are used, the greater the angle between the two ribs 14, the better the torsional resistance of the tube body 12.

[0087] In some selected embodiments, combined Figure 13 As shown, in order to simultaneously meet the anisotropic rigidity of the reinforcing rib 14 and minimize the impact on the bending performance of the tube body 12, preferably, two reinforcing ribs 14 are formed by cutting a metal hypotube. The two reinforcing ribs 14 are a composite integral structure with the two ends of the main body 140 connected to the fixing ring 18. The central angle α formed by each part of the two reinforcing ribs 14 on the radial cross section can be set to 120° to achieve a balance between the bending performance and the anti-torsion and anti-deflection performance of the tube body 12.

[0088] In some embodiments, combined Figure 14-15As shown, the reinforcing layer 124 and the reinforcing ribs 14 are a composite, integrated structure formed by continuously cutting a metal hypotube. At least two reinforcing ribs 14 are formed on the metal hypotube. The central angle α formed by the two reinforcing ribs 14 on the same radial cross-section can be set to a constant angle, for example, both are 120°. Alternatively, it can be set to a variable angle. Extending from the distal end to the proximal end of the bendable section 121 of the delivery sheath 10, the central angle α formed by the two reinforcing ribs 14 on each radial cross-section arranged axially continuously increases and transitions from 120° to 165°, thereby achieving better torsional resistance at the proximal end of the bendable section 121 of the delivery sheath 10 and better bending performance at the distal end of the bendable section 121. This corresponds to the situation where, after the delivery sheath 10 is bent, the proximal end of the bendable section 121 is more torsionally resistant, while the distal end of the bendable section 121 has relatively lower torsion resistance requirements.

[0089] In some embodiments, the delivery sheath 10 radially includes an inner lining 122, a reinforcement layer 124 in the form of a metal hypotube structure, and an outer layer 126 made of a thermoplastic elastomer. Figure 16 As shown, at least one reinforcing rib 14 is formed by cutting non-continuous segments on the metal hypotube. The reinforcing rib 14 includes at least two rib segments 141, which are spaced apart in the axial direction of the tube body 12. Each rib segment 141 of the reinforcing rib 14 has a length of 0.5 mm to 10 mm, a width of 0.05 mm to 3.0 mm, and a thickness of 0.05 mm to 0.3 mm. One of two adjacent rib segments 141 can be rotated circumferentially relative to the other by 0°, 90°, 120°, or 180°.

[0090] It is understood that the greater the width and thickness of the reinforcing ribs 14, the greater the rigidity of the reinforcing ribs 14, the greater the ability to resist deformation, the more significantly the rigidity of the tube body 12 is improved, and the more conducive it is to improving the torsional resistance of the tube body 12. However, with the corresponding increase in rigidity of the tube body 12, the tube body 12 also becomes more difficult to bend. When using segmented reinforcing ribs 14, it is possible to maintain the torsional resistance of the tube body 12 while appropriately improving its bending adaptability, thus achieving a good balance between the two.

[0091] In other embodiments, the number of discontinuous reinforcing ribs 14 is varied, with at least two discontinuous reinforcing ribs 14 arranged with the axial cross-section of the delivery sheath 10 where the bending adjustment wire 164 is located serving as a plane of symmetry. Discontinuous reinforcing ribs 14 can release deformation at spaced-apart locations, making them more susceptible to bending than continuous reinforcing ribs 14. This facilitates the bending of the delivery sheath 10, improves its bending performance, and helps reduce the overall rigidity of the tube body 12 of the delivery sheath 10.

[0092] Specifically, combined Figure 16-18As shown, the reinforcing rib 14 is composed of at least two rib segments 141 in the axial direction of the tube body 12. The length of each rib segment 141 is 0.5mm-10mm. The lengths of the rib segments 141 from far to near are L1, L2, ...L n , set to a length with a certain regular arrangement and combination. Preferably, the length L of the proximal rib segment 141 is n The ribs 141 are longer than the length L1 of the distal rib segment 141, and the length increases from distal to proximal to the proximal end of the bendable segment 121. This is because when the delivery sheath 10 is torsionally deflected, the maximum deformation is concentrated at the proximal end of the bendable segment 121. The longer proximal rib segment 141 helps the delivery sheath 10 achieve better torsional resistance.

[0093] In some embodiments, the width of the rib segment 141 of the discontinuous reinforcing rib 14 is specifically set to be 0.05mm-3mm, and the widths W1, W2, ... W n , forming a certain arrangement pattern in the radial direction. The wider the width, the better the deformation resistance of the reinforcing rib 14 and the better the torsional deflection resistance of the tube body 12. Preferably, the rib segment 141 with the largest width is arranged at the proximal end of the bendable segment 121 to obtain the strongest torsional deflection resistance.

[0094] In other embodiments, at least two discontinuous reinforcing ribs 14 are provided on the reinforcing layer 124 formed by cutting the metal hypotube. The central angle formed between the at least two reinforcing ribs 14 on the same radial cross-section forms an angle α, which can be anywhere from 0° to 180°. Each reinforcing rib 14 can be composed of rib segments 141 of uniform length and width to ensure that the hardness of the bendable section 121 of the tube body 12 does not change suddenly. Adjacent rib segments 141 are formed alternately, with an offset central angle β, which can be anywhere from 0° to 90°. The discontinuous reinforcing ribs 14 formed by the displaced rib segments 141 are equivalent to increasing the number of reinforcing ribs 14, thereby helping to improve the torsional and deflection resistance of the entire tube body 12.

[0095] In some embodiments, the central angle α formed by the distal ends of at least two reinforcing ribs 14 on the same radial cross-section is preferably 120°, the rib segments 141 formed by cutting have a rectangular cross-section, and the offset angle β between adjacent rib segments 141 is preferably set to 30°. This configuration optimizes the anti-deflection performance of the delivery sheath 10. It should be emphasized that using a cut metal hypotube as the reinforcing layer 124 facilitates the production of reinforcing ribs 14 of varying lengths, widths, and positions.

[0096] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A delivery sheath, characterized in that: The invention comprises a tube body, only one bending wire and only one reinforcing rib; the tube body comprises a main section and a bendable section in the axial direction; the tube body comprises an inner lining, a reinforcing layer and an outer layer arranged from the inside to the outside in the radial direction, wherein the reinforcing layer is one or a combination of a spring coil, a metal braided mesh or a cut hypotube; the reinforcing rib is arranged in the tube body along the axial direction of the tube body, and the reinforcing rib is configured on the outer side of the bend of at least part of the bendable section; in the radial cross section, the reinforcing rib is located at a position symmetrically distributed with respect to the bending wire, and the reinforcing rib and the bending wire are located on the same radial straight line.

2. The delivery sheath according to claim 1, characterized in that The reinforcing ribs penetrate the entire tube body along the axial direction of the tube body, or are only arranged in a portion of the tube body.

3. The delivery sheath according to claim 1 or 2, characterized in that: The reinforcing ribs are located between the inner lining of the pipe body and the reinforcing layer, or between the reinforcing layer and the outer layer, or the reinforcing ribs and the reinforcing layer are constructed into a composite integral structure.

4. The delivery sheath according to claim 1 or 2, characterized in that: The reinforcing rib is made of at least one round wire or flat wire; the radial cross-section of the round wire is circular, and the wire diameter is 0.05mm-1.0mm; the radial cross-section of the flat wire is rectangular, the long side of the rectangle is 0.05mm-3.0mm, and the short side is 0.05mm-0.2mm, wherein the short side of the rectangle extends along the radial direction of the tube body.

5. The delivery sheath according to claim 4, characterized in that: The reinforcing rib is only arranged on the bendable section. The reinforcing rib is made by combining two or more round wires or flat wires in parallel, or by combining round wires and flat wires in parallel. The distal end and proximal end of the reinforcing rib are respectively connected to fixing rings.

6. The delivery sheath according to claim 1 or 2, characterized in that: The reinforcing ribs are special-shaped ribs formed by connecting multiple sections of metal wires of different shapes in series.

7. The delivery sheath according to claim 6, characterized in that: The special-shaped ribs are formed by alternatingly connecting at least two segments with different radial cross-sectional shapes. The segments with the same cross-sectional shape have uniform lengths or are arranged in increasing order from far to near to the proximal end of the bendable segment.

8. The delivery sheath according to claim 3, characterized in that: The reinforcing ribs are formed by cutting a metal hypotube, and continuous reinforcing ribs are formed on the outer side of the bend of at least part of the bendable section.

9. The delivery sheath according to claim 8, characterized in that: The reinforcing rib includes a main body, the radial cross-section of the main body is a rectangle, the long side of the rectangle is 0.05mm-3.0mm, and the short side of the rectangle is 0.05mm-0.2mm, wherein the short side of the rectangle extends along the radial direction of the tube body; the overall length of the main body is equal to the length of the bendable section.

10. The delivery sheath according to claim 9, characterized in that: Both ends of the reinforcing rib are respectively a fixing ring cut and formed integrally with the main body, and the axial length of each fixing ring is 0.5mm-2mm.

11. A delivery system comprising the delivery sheath according to any one of claims 1 to 10, and an inner layer catheter accommodated in the lumen of the delivery sheath.

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