Sheath for delivering an interventional instrument and sheath assembly

Abstract

The application discloses a sheath core assembly, a sheath assembly, a sheath, a sheath processing method, and an interventional instrument conveying system and conveying method. The sheath core assembly for conveying an interventional instrument comprises a core tube, a locking piece fixed to the distal end of the core tube and used for connecting the interventional instrument, and a bending pipe sleeved on the outer periphery of the core tube. The distal ends of the bending pipe and the core tube are fixedly connected with each other, and the proximal ends of the two are relatively slidable.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a sheath and sheath assembly for facilitating the delivery of interventional devices. Background Technology

[0002] Interventional device delivery systems generally include a sheath core assembly and a sheath that slides outside the sheath core assembly. These two components form the sheath assembly, with its distal end accessible to the body's vascular system and its proximal end connected to the operating handle. Due to the tortuous nature of the human vascular system and the need for long-distance operation, the distal end requires adjustment and control to move it to the target location. This places higher demands on the sheath's mechanical properties, such as balancing axial support and flexibility. Furthermore, the location and method of applying force during bending also affect safety and ease of operation. Summary of the Invention

[0003] This application provides a sheath and sheath assembly for delivering interventional devices, which improves overall performance through the rational arrangement of multiple layers and segments of the sheath, as well as structural improvements, such as at the distal end.

[0004] This application discloses a sheath for delivering interventional devices, wherein the distal end of the sheath is a loading section for receiving the interventional devices. The loading section has a multi-layer structure, comprising, from the inside out, an inner liner, a metal tube, and an outer membrane. The metal tube comprises, from the proximal end to the distal end, a main body tube and a head end tube that are connected to each other.

[0005] The head tube includes a body section, a plurality of elastic expansion plates arranged circumferentially at intervals on the distal side of the body section, a first connector on the proximal side of the body section, and a second connector on the distal side of the body tube. The first connector and the second connector are interlocked and complementary in shape.

[0006] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0007] Optionally, each expansion piece has a cutout area.

[0008] Optionally, the expansion plates are evenly arranged circumferentially, with a quantity of 3 to 6.

[0009] Optionally, the first connector is T-shaped.

[0010] Optionally, the body segment is hollowed out to form a developing area for mounting developing points.

[0011] Optionally, both the body segment and the first connector have through holes, and the inner liner and the outer membrane are thermally fused together at the through holes.

[0012] Optionally, the hollowed-out area consists of multiple through holes spaced apart along the axial direction of the sheath tube, and the total area of ​​the through holes on each expansion piece is less than 50% of the area of ​​the expansion piece.

[0013] Optionally, on the same expansion piece, the area of ​​the through hole is larger the closer it is to the far end.

[0014] Optionally, the through holes are circular or elliptical, and the number of through holes on the same expansion piece is 2 to 5.

[0015] Optionally, the hollowed-out area is a strip-shaped hole that extends axially along the head end tube.

[0016] Optionally, there are two strip holes on the same expansion piece.

[0017] Optionally, the strip-shaped holes extend to the same width.

[0018] Optionally, the two ends of the strip hole along its length are arc-shaped inner edges.

[0019] Optionally, there is a gap between two adjacent expansion pieces, and each expansion piece has a narrowing portion at its proximal end, and the gap has a widening portion at its proximal end corresponding to the narrowing portion.

[0020] Optionally, the inner edge of the widened portion is a smooth curve.

[0021] Optionally, the central region of the spaced opening extends with equal width along its length.

[0022] Optionally, the width of the equal-width extension portion of the interval opening is approximately the same as the width of the strip hole.

[0023] Optionally, the proximal side of the strip-shaped hole extends beyond the narrowing portion of the expansion piece.

[0024] Optionally, the proximal side of the strip hole extends 1–5 mm beyond the narrowed portion of the expansion piece.

[0025] Optionally, the distal end of the expansion piece has a smooth outer edge.

[0026] Optionally, the metal tube includes a head tube, a main tube, and an extension tube connected sequentially from the distal end to the proximal end, wherein in the axial direction, the head tube and the main tube are both distributed in the loading section, and the extension tube is distributed in the bending section.

[0027] Optionally, the extension tube is a hyaluronic acid tube.

[0028] Optionally, the head tube is cut from a nickel-titanium alloy tube, and the main tube and the extension tube are cut from stainless steel tubes.

[0029] Optionally, the head tube is made of nickel-titanium alloy, and each expansion piece has a closed state extending along the axial direction of the sheath tube and an outward-turned state that is far apart from each other.

[0030] Optionally, the head tube and the main tube are connected by a connector with complementary shapes, and the main tube and the extension tube are connected by a hook.

[0031] Optionally, the main tube has two hollowed-out areas distributed on its wall, and two guide ribs that extend axially and are arranged opposite each other in the radial direction are distributed between the two hollowed-out areas.

[0032] Optionally, along the axial direction of the sheath, the outer membrane comprises multiple segments, each made of a different material, or at least both made of the same material.

[0033] Optionally, the strength of the outer film corresponding to the main tube is greater than the strength of the outer film corresponding to the far end of the head tube.

[0034] Optionally, the main tube and the head tube are cut from metal tubes of different materials.

[0035] This application also provides a sheath assembly, including a slidingly nested sheath and a sheath core assembly, the sheath core assembly including a core tube, the distal end of which is fitted with a locking member for connecting an interventional device; the sheath is located on the outer periphery of the sheath core assembly and is the sheath for delivering the interventional device as described in this application.

[0036] Optionally, the sheath-core assembly further includes a bending tube sleeved around the periphery of the core tube, wherein the distal ends of the bending tube and the core tube are fixedly connected to each other, and their proximal ends can slide relative to each other.

[0037] Optionally, the sheath-core assembly further includes a bending tube located inside the core tube, wherein the distal ends of the bending tube and the core tube are fixedly connected to each other, and their proximal ends are slidable relative to each other.

[0038] Optionally, the core tube extends distally from the locking member and a guide head is fixed at the distal end of the extension. The space between the guide head and the locking member is the loading position for the interventional device, and the compressed interventional device is located in this loading position and connected to the locking member.

[0039] Optionally, the core tube includes a compliant section adjacent to the locking element and a third extension section that is connected to the compliant section and extends proximally, wherein the compliant section is made of a hyaluronic acid tube and has a length ranging from 120 to 18 mm, and the third extension section is made of a steel cable tube or a hyaluronic acid tube.

[0040] Optionally, the bending tube includes a pulling section and a second extension section from the far end to the near end, wherein the pulling section is an integral structure and uses a hyaluronic acid tube.

[0041] Optionally, the traction segment includes a first traction segment, a transition segment, and a second traction segment sequentially from the distal end to the proximal end. The first traction segment has higher compliance than the second traction segment, and the length ratio of the first traction segment to the length of the compliance segment is 1:0.7 to 1.5.

[0042] Optionally, the compliant section is formed by cutting to create a first reinforcing rib extending axially.

[0043] Optionally, the cut width of the conforming section is 0.1 to 1 mm, and the cut spacing is 0.1 to 1 mm.

[0044] Optionally, in the compliant segment, the closer to the far end, the smaller the limiting radius of curvature after bending.

[0045] Optionally, in the compliant section, the cut width gradually changes, and the cut width increases as it approaches the far end.

[0046] Optionally, in the compliant segment, the seam spacing gradually changes, and the seam spacing becomes smaller as it approaches the far end.

[0047] Optionally, the stiffness of the compliant segment gradually changes, and the stiffness decreases as it approaches the far end.

[0048] Optionally, the first tensioning section is formed by cutting to create an axially extending second reinforcing rib, the second reinforcing rib being 180 degrees apart from the first reinforcing rib in the circumferential direction.

[0049] Optionally, the slit width of the first pulling section is 0.03 to 0.5 mm, and the slit spacing is 0.2 mm to 0.85 mm.

[0050] Optionally, the second tensioning section is formed by cutting to create two axially extending third reinforcing ribs. The two third reinforcing ribs are radially opposite each other and are 90 degrees apart from the circumferential position of the first reinforcing rib.

[0051] Optionally, the slit width of the second pulling section is 0.03 to 0.5 mm, and the slit spacing is 0.2 mm to 0.85 mm.

[0052] Optionally, the transition segment is an uncut structure that completes the entire circle in the circumferential direction.

[0053] Optionally, the sheath is axially arranged from distal to proximal as the loading section, the bending section, and the first extension section; the proximal end of the inner liner is connected to the inner sheath, which is distributed axially in the bending section and the first extension section; the proximal end of the main tube is connected to a metal extension tube, which is distributed axially in the bending section; and the outer membrane extends proximally to wrap around the periphery of the extension tube.

[0054] Optionally, the inner sheath adopts a multi-layer structure, with a fourth reinforcing rib extending axially in the interlayer. There are two fourth reinforcing ribs, one of which is located at the same circumferential position as the first reinforcing rib, and the other is located 180 degrees away from the first reinforcing rib in the circumferential position.

[0055] Optionally, the distal end of the fourth reinforcing rib extends to the proximal end or the distal end of the extension tube.

[0056] Optionally, the extension tube is provided with a fifth reinforcing rib extending axially. The fifth reinforcing rib is one and is located at the same circumferential position as the first reinforcing rib; or there are two fifth reinforcing ribs, one of which is located at the same circumferential position as the first reinforcing rib, and the other is located 180 degrees away from the first reinforcing rib in the circumferential position.

[0057] This application also provides a method for processing a sheath, including:

[0058] Step S100: Provide an inner sheath and process a flared portion at the distal end of the inner sheath;

[0059] Step S200: The inner liner tube is fitted and fixed around the outer periphery of the flared portion;

[0060] Step S300: A metal tube is fitted around the outer periphery of the distal end of the inner sheath and around the outer periphery of the inner liner.

[0061] In step S400, the outer surface of the metal tube is covered in sections using an outer material, and the outer material of each section is melted to form an outer film.

[0062] The sheath tube may be the sheath tube described in this application, that is, this application also provides a method for processing the sheath tube, including:

[0063] Step S100: A flared portion is formed at the distal end of the inner sheath.

[0064] Step S200: The inner liner tube is fitted and fixed around the outer periphery of the flared portion;

[0065] Step S300: The metal tube is fitted around the outer periphery of the inner sheath tube and the inner liner tube;

[0066] In step S400, the outer surface of the metal tube is covered in sections using an outer coating material, and the outer coating material of each section is melted and then used to form the outer coating film.

[0067] Optionally, in step S200, the proximal end of the inner liner tube has multiple ear pieces arranged at intervals along the circumference. The multiple ear pieces are overlapped and wrapped around the outer periphery of the flared part, and then the multiple ear pieces are wrapped with a fixing sleeve and then heat-fused to fix them.

[0068] Optionally, 3 to 6 ear pieces are evenly arranged circumferentially.

[0069] Optionally, the inner liner tube is made of PTFE.

[0070] Optionally, the retaining sleeve is made of Pebax material.

[0071] Optionally, step S400 specifically includes:

[0072] Step S410: Wrap the first connecting sleeve around the joint between the main tube and the head tube, wrap the head tube with the head sleeve, and heat-melt the first connecting sleeve and the head sleeve together.

[0073] Step S420: Wrap the outer casing around the main tube and fix it with heat fusion;

[0074] Step S430: Wrap the second connecting sleeve around the inner sheath tube at the proximal end of the extension tube and the adjacent part, and fix the second connecting sleeve by heat fusion.

[0075] Step S440: Wrap the connecting sleeve around the outer circumference of the extension tube and fix it by heat fusion.

[0076] Optionally, the main tube has a hollowed-out area with intervals, and guide ribs are formed between adjacent hollowed-out areas. In step S420, before wrapping the main body jacket around the main tube, a liner is placed in each hollowed-out area and fixed by heat fusion.

[0077] Optionally, the liner is made of Pebax material.

[0078] Optionally, the head end jacket and the connecting sleeve are made of TPU material.

[0079] Optionally, the first connecting sleeve, the second connecting sleeve, and the main outer sleeve are all made of Pebax material. This application also provides an interventional device delivery system having opposing distal and proximal ends. The delivery system includes an operating handle at the proximal end and a sheath assembly connected to the operating handle and extending distally. The sheath assembly includes a sheath tube and a sheath core assembly, with both the sheath core assembly and the proximal end of the sheath tube extending to the operating handle.

[0080] The operating handle, sheath, and sheath core assembly in the delivery system may be at least one of the operating handle, sheath, and sheath core assembly described in this application.

[0081] This application also provides a method for delivering interventional devices, including loading the interventional device into a delivery system and then delivering it to a distal end;

[0082] The delivery system includes a proximal operating handle and a sheath assembly connected to the operating handle and extending distally. The sheath assembly includes a sheath tube and a sheath core assembly. An interventional device is connected to the sheath core assembly and enclosed by the sheath tube. The sheath core assembly includes a core tube, a locking device fixed to the distal end of the core tube for connecting the interventional device, and a bending tube. The distal ends of the bending tube and the core tube are fixedly connected to each other, and their proximal ends are slidable relative to each other and both extend to the operating handle.

[0083] During the delivery process, the proximal end of the bending tube is pulled, causing the proximal ends of the bending tube and the core tube to slide relative to each other, and driving the distal end of the core tube to change its orientation to adapt to the intervention path.

[0084] This application also provides an operating handle for delivering interventional devices to the human body, which connects to the proximal ends of three tubes nested in sequence and drives the proximal ends of the three tubes to move relative to each other. The three tubes, from the inside out, are a core tube, a bending tube, and a sheath tube. The operating handle includes a control component, a bending component, and a front handle.

[0085] The control component includes:

[0086] A first support body fixed relative to the front handle;

[0087] A first connector is slidably mounted on the first support body, and the proximal end of the sheath is fixed to the first connector;

[0088] A first driving member that is movably mounted on the first support and drives the first connecting member to slide;

[0089] The bending assembly includes:

[0090] A second support body that is fixed relative to the first support body;

[0091] The second connector is slidably installed on the second support body, and the proximal end of the bending tube passes through the sheath and is fixed to the second connector;

[0092] A second driving member that is movably mounted on the second support and drives the second connector to slide;

[0093] A pipe joint is fixedly installed at the proximal end of the second support body, and the proximal end of the core tube passes through the bending pipe and is fixed to the pipe joint.

[0094] Optionally, the front handle is connected to a conduit sleeved outside the sheath.

[0095] Optionally, the first driving member is rotatably sleeved on the outer periphery of the first support body, and a limiting mechanism is provided between the front handle and the first driving member to limit the rotation angle of the first driving member.

[0096] Optionally, the limiting mechanism includes:

[0097] A sliding key is installed on one of the front handle and the first drive component;

[0098] A lock hole is provided in the other of the front handle and the first drive member.

[0099] Optionally, the outer wall of the front handle is provided with a sliding groove, the sliding key is installed in the sliding groove, and the lock hole is opened on the axial end face of the first drive member.

[0100] Optionally, the limiting mechanism includes a locking pin that is threaded onto the first drive member and abuts against the first support.

[0101] Optionally, the first support body is cylindrical, and the side wall of the first support body is provided with a guide bar hole extending axially. The first connector is slidably installed inside the first support body, and the first connector is provided with a guide key extending radially out of the guide bar hole. The inner wall of the first drive member has a threaded structure that mates with the guide key.

[0102] Optionally, the second support is cylindrical and arranged coaxially with the first support, and the second support and the first support are fixed together as an integral structure or separately.

[0103] Optionally, the second drive member is rotatably mounted relative to the second support body, the second support body has an operating port, a portion of the second drive member is placed inside the second support body, and at least a portion is exposed to the operating port as a force-applying part, and the second connector is located inside the second support body and is linked with the second drive member.

[0104] Optionally, the second drive member has an internal thread, and at least a portion of the second connector has an external thread and extends into the second drive member, wherein the second drive member drives the second connector to slide in a threaded manner.

[0105] Optionally, the inner wall of the second support is provided with a guide strip extending axially, and at least a portion of the second connector is located within the second support, with the outer wall of that portion provided with a guide groove that mates with the guide strip.

[0106] The conveying system of this application has been further improved in terms of the operating handle, sheath core assembly, sheath tube and their connection method, which makes it easier to adjust the bending operation and meet the performance requirements of each component. Attached Figure Description

[0107] Figure 1 This is a schematic diagram of the conveying system of this application;

[0108] Figure 2 for Figure 1 Exploded view of components of the conveyor system;

[0109] Figure 3a for Figure 1 Schematic diagram of the internal structure of the control handle;

[0110] Figure 3b for Figure 1 A schematic diagram of the internal structure of the control handle from another perspective;

[0111] Figure 3c for Figure 3b A magnified view of a portion of the image;

[0112] Figure 4 for Figure 1 Exploded view of the components of the control handle;

[0113] Figure 5a This is a schematic diagram of the locking mechanism of the core tube assembly using a wired control method in one embodiment of this application;

[0114] Figure 5b for Figure 5a Diagram showing the interaction between the locking mechanism and the access device;

[0115] Figure 5c This is a schematic diagram of the core tube assembly in one embodiment of this application;

[0116] Figure 6 This is a schematic diagram of the bending pipe in one embodiment of this application;

[0117] Figure 7 This is a schematic diagram of the core tube (compliant section) in one embodiment of this application;

[0118] Figure 8 for Figure 7 A structural schematic diagram of the core tube (compliant section) from another angle;

[0119] Figure 9 This is a schematic diagram of the bending pipe in one embodiment of this application;

[0120] Figure 10 for Figure 9 A structural diagram of the middle adjustment bend at another angle;

[0121] Figure 11 for Figure 9 Development diagram of the central adjustment bend;

[0122] Figure 12 This is a schematic diagram of the sheath structure in one embodiment of this application;

[0123] Figure 13 for Figure 5c , Figure 6 , Figure 12 A schematic diagram of the assembled components;

[0124] Figure 14 This is a cross-sectional view of a sheath assembly in one embodiment of this application;

[0125] Figure 15a for Figure 14 A schematic diagram of the structure after the interventional device is loaded;

[0126] Figure 15b for Figure 15a A schematic diagram of the structure of the interventional device during partial release;

[0127] Figure 15c for Figure 15a A schematic diagram of the structure after the interventional device has been fully released;

[0128] Figure 15d This is a schematic diagram showing the relative axial segments of each pipe fitting in one embodiment of this application;

[0129] Figure 16 This is a cross-sectional view of the sheath and inner core assembly in one embodiment of this application;

[0130] Figure 17a for Figure 16 A schematic diagram of the structure after the interventional device is loaded;

[0131] Figure 17b for Figure 17a A schematic diagram of the structure of the interventional device during partial release;

[0132] Figure 17c for Figure 17a A schematic diagram of the structure after the interventional device has been fully released;

[0133] Figure 17d This is a schematic diagram showing the relative axial segments of each pipe fitting in one embodiment of this application;

[0134] Figure 18 A diagram showing the components inside the sheath;

[0135] Figure 19a This is a schematic diagram of the head end tube structure;

[0136] Figure 19bThis is a schematic diagram of the unfolded structure of the head end tube in another embodiment;

[0137] Figure 20 This is a schematic diagram of the remote portion of the conveying system of this application;

[0138] Figure 21 for Figure 20 A cross-sectional view of the inner sheath at the CC region;

[0139] Figure 22 for Figure 21 Enlarged view of part A in the middle;

[0140] Figure 23 for Figure 20 A sectional view of the BB section;

[0141] Figure 24 for Figure 20 A cross-sectional view of the BB portion of another embodiment;

[0142] Figures 25-34 This is a schematic diagram showing the components and related changes involved in the sheath processing in one embodiment of this application;

[0143] Figure 35 This is a schematic diagram showing the changes at the far end of the conveyor system during bending in this application;

[0144] Figures 36-40 This is a schematic diagram illustrating the state changes of different processes in the usage scenario of the delivery system of this application.

[0145] The annotations in the figure are explained as follows:

[0146] 100. Operating handle;

[0147] 110. Bending assembly; 111. Second support body; 112. Second drive component; 113. Second connector; 114. Guide bar; 115. Guide groove; 116. Operating port; 117. Force application part; 118. Luer joint;

[0148] 120. Control component; 121. First support body; 122. First drive component; 123. First connector; 124. Guide key; 125. Guide strip hole; 126. Lock hole;

[0149] 130. Front handle; 131. Sliding button; 132. Slide groove;

[0150] 200. Catheter;

[0151] 300. Sheath; 310. Loading section; 320. Bending section; 330. First extension section;

[0152] 340. Head end tube; 341. Spacing opening; 342. Developing area; 343. First connector; 344. Expander; 345. Hollowed-out area; 346. Body section; 347. Through hole; 348. Narrowing section; 349. Proximal side of the strip hole;

[0153] 350. Main tube; 351. Second connector; 352. Finishing part; 353. Hollowed-out area; 354. Hollowed-out area; 355. Guide rib;

[0154] 360. Extension tube; 3601. Reinforcing rib (fifth reinforcing rib); 3602. Reinforcing rib (fifth reinforcing rib);

[0155] 370. Inner sheath; 370A. Distal portion; 370B. Proximal portion; 3701. PTFE inner layer; 3702. Braided layer; 3703. Reinforcing rib (fourth reinforcing rib); 3704. Braided layer; 3705. Outer layer; 371. Distal end; 372. Mandrel; 373. Frustum section; 374. Flared end; 375. Inner liner; 376. Cutting area; 377. Fixing sleeve;

[0156] 380. Outer film; 381. First connecting sleeve; 382. Head end outer sleeve; 383. First liner; 384. Second liner; 385. Main body outer sleeve; 386. Second connecting sleeve; 387. Connecting sleeve;

[0157] 400. Sheath core assembly;

[0158] 410. Adjusting pipe; 411. First tension section; 4111. Reinforcing rib (second reinforcing rib); 412. Second tension section; 4121. Reinforcing rib (third reinforcing rib); 4122. Reinforcing rib (third reinforcing rib); 413. Second extension section; 414. Transition section;

[0159] 420. Core tube assembly; 421. Guide head; 422. Locking element; 4221. Lock hole; 4222. Cable divider; 4223. Pull cable; 4224. Locking rod; 4225. Cable sleeve; 423. Pressure strip; 424. Inner core; 425. Core tube; 4251. Compliant section; 4252. Third extension section; 4253. Reinforcing rib (first reinforcing rib);

[0160] 500. Interventional devices; 501. Connecting ear;

[0161] 600. Aortic valve. Detailed Implementation

[0162] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0163] It should be noted that when a component is said to be "connected" to another component, it can be directly connected to the other component or it can be connected to a component in between. When a component is said to be "set on" another component, it can be directly set on the other component or it may be set to a component in between.

[0164] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The term "and / or" as used herein includes any combination of one or more of the associated listed items.

[0165] See Figures 1-4 One embodiment of this application provides a delivery system having a distal end and a proximal end. The delivery system includes an operating handle 100 at the proximal end, a sheath 300 connected to the operating handle 100 and extending distally, and a sheath core assembly 400. The sheath 300 is slidably fitted to the outer periphery of the sheath core assembly 400.

[0166] The sheath core assembly includes a core tube and a locking device fixed to the distal end of the core tube for connecting to the interventional device. The locking device can have various different structural forms, such as a groove to connect to the connecting ear on the stent, a radially outward protruding head, or a wire-controlled method, using a long wire or wire loop to connect to the stent. Regardless of the form, the purpose is to achieve connection with the connecting ear of the stent.

[0167] In some embodiments, the sheath-core assembly further includes a bending tube sleeved around the periphery of the core tube, wherein the distal ends of the bending tube and the core tube are fixedly connected to each other, and the proximal ends of both extend to the operating handle and can slide relative to each other.

[0168] In some embodiments, the sheath-core assembly further includes a bending tube located inside the core tube, wherein the distal ends of the bending tube and the core tube are fixedly connected to each other, and their proximal ends are slidable relative to each other.

[0169] Regardless of their internal / external relationship, the core tube and the bending tube need relative movement at their proximal ends. Generally, during bending, the proximal end of the core tube is kept constant, or rather, the proximal end of the bending tube is pulled using the proximal end of the core tube as a reference. Differences in the internal / external relationship between the core tube and the bending tube can result in different contact points at the bend. The following embodiments and accompanying drawings primarily use the bending tube on the outer side as an example. The structure of the operating handle can be adjusted accordingly based on the internal / external relationship between the core tube and the bending tube to allow relative movement at their proximal ends.

[0170] In other embodiments, the delivery system may further include a catheter 200 fixed relative to the operating handle 100, the catheter 200 being used to establish a channel to prevent damage to internal tissues during the reciprocating motion of the sheath 300. The interventional device is loaded into the sheath core assembly 400 and, encased in the sheath 300, enters the body along with the catheter 200. The sheath 300 can then move axially relative to both the catheter and the sheath 300 to release the interventional device and, if necessary, retrieve it.

[0171] The bending is primarily achieved by operating handle 100. (Reference) Figure 3a and Figure 4 In one embodiment shown, the operating handle 100 is used to connect the proximal ends of three tubes nested inside and outside in sequence, and to drive the proximal ends of the three tubes to move relative to each other. The three tubes are, from the inside out, a core tube, a bending tube, and a sheath tube. The operating handle 100 includes a control component 120, a bending component 110, and a front handle 130.

[0172] The control component 120 includes:

[0173] The first support body 121 is fixed relative to the front handle 130;

[0174] A first connector 123 is slidably mounted on the first support 121, and the proximal end of the sheath is fixed to the first connector 123;

[0175] A first driving member 122 is movably installed on the first support 121 and drives the first connector 123 to slide;

[0176] The bending assembly 110 includes:

[0177] A second support 111 is fixed relative to the first support 121;

[0178] The second connector 113 is slidably installed on the second support 111, and the proximal end of the bending tube passes through the sheath and is fixed to the second connector 113;

[0179] A second driving member 112 is movably installed on the second support 111 and drives the second connector 113 to slide;

[0180] A pipe joint is fixedly installed at the proximal end of the second support body 111, and the proximal end of the core tube passes through the bending pipe and is fixed to the pipe joint.

[0181] Specifically, the control component 120 includes a first support body 121, a first drive member 122 rotatably sleeved on the outer periphery of the first support body 121, a guide bar hole 125 extending axially on the side wall of the first support body 121, a first connector 123 slidably installed inside the first support body 121, a guide key 124 extending from the guide bar hole 125 on the first connector 123, and a threaded structure on the inner wall of the first drive member 122 that mates with the guide key 124.

[0182] In one embodiment, the first support 121 is cylindrical, and the side wall of the first support 121 has a guide bar 114 hole extending axially. The first connector 123 is slidably installed inside the first support 121. The first connector 123 is provided with a guide key 124 extending radially out of the guide bar 114 hole. The inner wall of the first drive member 122 has a threaded structure that mates with the guide key 124.

[0183] Specifically, the first support 121 is roughly cylindrical and can be a one-piece or radially interlocking split structure (e.g. Figure 4 When the first driving member 122 rotates, it drives the first connecting member 123 to slide inside the first support body 121 through the guide key 124. Due to the restriction of the guide bar hole 125, the first connecting member 123 does not rotate, that is, it only moves axially.

[0184] The front handle 130 is fixedly connected to the first support 121, the proximal end of the conduit 200 is fixedly inserted into the front handle 130, the proximal end of the sheath 300 is fixedly installed on the first connector 123, and the sheath 300 extends distally through the conduit 200.

[0185] Regarding the cooperation relationship between the first support 121 and the second support 111, referring to one embodiment, the second support 111 is cylindrical and arranged coaxially with the first support 121, and the second support 111 and the first support 121 are fixed together by an integral structure or separately.

[0186] Regarding the cooperation relationship between the second drive member 112 and the second support body 111, referring to one embodiment, the second drive member 112 is rotatably mounted relative to the second support body 111, the second support body 111 has an operation port 116, a portion of the second drive member 112 is placed inside the second support body 111, and at least a portion is exposed to the operation port 116 as a force application part 117, and the second connector 113 is located inside the second support body 111 and is linked with the second drive member 112.

[0187] Specifically, the bending assembly 110 includes a second support 111, which is also generally cylindrical and fixed relative to the first support 121. The second support 111 itself can adopt an integral or radially snap-fit ​​split structure (e.g., Figure 4 The second support 111 and the first support 121 are arranged coaxially and are fixedly connected separately.

[0188] Correspondingly, the bending assembly 110 also includes a second driving member 112. In a specific embodiment, the second driving member 112 has an internal thread, and at least a portion of the second connecting member 113 has an external thread and extends into the second driving member 112. The second driving member 112 drives the second connecting member 113 to slide in a threaded manner.

[0189] Specifically, the second driving member 112 is rotatably mounted relative to the second support body 111. The second support body 111 has a partial opening 116. A portion of the second driving member 112 is placed inside the second support body 111, and at least a portion is exposed to the opening 116 as a force-applying part 117. The second driving member 112 is generally cylindrical and has internal threads. A second connecting member 113 is slidably mounted inside the second driving member 112.

[0190] To limit the movement of the second connector 113, in one embodiment, the inner wall of the second support 111 is provided with an axially extending guide strip 114, and at least a portion of the second connector 113 is located within the second support 111, with the outer wall of this portion provided with a guide groove 115 that mates with the guide strip 114. In this embodiment, the engagement of the guide groove 115 and the guide strip 114 allows the second connector 113 to slide only axially relative to the second support 111.

[0191] As can be easily understood from the above description, the bending function of the operating handle 100 is mainly achieved through the rotation between various components. To prevent instability in the bending state caused by the movement of various components during operation, a corresponding limiting mechanism can be set. Referring to one embodiment, the first driving member 122 is rotatably sleeved on the outer periphery of the first support body 121, and a limiting mechanism is provided between the front handle 130 and the first driving member 122 to limit the rotation angle of the first driving member 122.

[0192] Accordingly, this embodiment exemplarily provides a method for setting a limiting mechanism. Referring to one embodiment, the limiting mechanism includes:

[0193] A sliding key 131 is installed in one of the front handle 130 and the first drive component 122;

[0194] A keyhole 126 is provided in one of the front handle 130 and the first drive member 122.

[0195] When the sliding key 131 engages with the locking hole 126, the circumferential positions of the front handle 130 and the first driving member 122 are determined. Therefore, the axial position of the first connecting member 123 relative to the front handle 130 is determined, and the bending function of the operating handle 100 is restricted, ensuring stability during use. In an actual product, a specific configuration can be found in one embodiment where the outer wall of the front handle 130 has a groove 132, the sliding key 131 is installed in the groove 132, and the locking hole 126 is located on the axial end face of the first driving member 122.

[0196] The number of keyholes 126 can be increased to achieve locking of the first drive member 122 in multiple positions. (Reference) Figure 3c Multiple locking holes are provided on the axial end face of the first driving member 122 and are arranged sequentially along the circumferential surface of the first driving member 122. Increasing the number of locking holes 126 can increase the number of locking positions of the first driving member 122. However, correspondingly, increasing the number of locking holes 126 will increase the manufacturing difficulty of the first driving member 122 and reduce the gap between adjacent locking holes 126, thereby reducing the strength of a single locking hole 126. Therefore, the specific number can be adjusted according to design requirements, actual working conditions and actual product dimensions.

[0197] exist Figure 3b and Figure 3c In the given embodiment, because the first driving member 122 is a split structure that interlocks vertically, the locking hole 126 near the separation point has two configurations: one is an open configuration facing the separation point, and the other is a closed configuration that avoids the separation point. In a specific product, only one of the two configurations may appear.

[0198] Correspondingly, a limiting mechanism can also be provided between the first driving member 122 and the first support body 121 to achieve the above-mentioned functions. Referring to one embodiment, the limiting mechanism includes a locking pin (not shown) that is threaded onto the first driving member 122 and abuts against the first support body 121. The locking pin's screw connection with the first driving member 122 can achieve the relative position of itself and the first driving member 122, thereby achieving the positioning of the first support body 121. When the relative position of the first driving member 122 and the first support body 121 is determined, the function of the limiting mechanism described above can also be achieved, so the locking principle will not be elaborated further.

[0199] One embodiment of this application provides a sheath-core assembly for delivering interventional devices, including a core tube and a locking member fixed to the distal end of the core tube for connecting the interventional device. The sheath-core assembly also includes a bending tube sleeved around the periphery of the core tube. The distal ends of the bending tube and the core tube are fixedly connected to each other, while their proximal ends are slidable relative to each other. The sheath-core assembly 400 includes a bending tube 410 and a core tube 425 nested together. The bending tube 410 wraps around the core tube 425, and their distal ends are fixedly connected to each other, while their proximal ends are slidable relative to each other. The proximal end of the bending tube 410 is fixed to a second connector 113, and the proximal end of the core tube 425 extends out of the second connector 113 and is fixed to the tail end (proximal side) of the second support 111. To facilitate docking with external tubing, a pipe connector, such as a Luer connector 118, is installed on the proximal end of the core tube 425.

[0200] When the interventional device needs to be released or retrieved, rotating the first drive member 122 causes the first connector 123 to move axially, which in turn causes the sheath 300 to move relative to the sheath-core assembly 400. When bending is required, rotating the second drive member 112 causes the second connector 113 to move axially, which in turn causes the proximal end of the bending tube 410 to move relative to the proximal end of the core tube 425. Since the distal ends of the two are fixed to each other, the relative movement of the proximal ends will cause the distal ends of the two to bend radially together.

[0201] See Figures 5a to 11 The sheath-core assembly 400 includes a bending tube 410 and a core tube assembly 420. The core tube assembly 420 includes a core tube 425. A locking element 422 is installed at the distal end of the core tube 425 for connecting to an interventional device. The bending tube 410 is sleeved around the core tube 425. The distal ends of the bending tube 410 and the core tube 425 are fixedly connected to each other, while their proximal ends can slide relative to each other.

[0202] The distal end of the bending tube 410 extends to the proximal end of the adjacent locking element 422. The bending tube 410 can be directly fixed to the core tube 425, or directly fixed to the adjacent locking element 422, or a combination of both fixing methods. Both the bending tube 410 and the core tube 425 can be made of metal materials such as hyaluronic acid tubes and fixed by welding, bonding or fasteners.

[0203] The distal end of the core tube 425 extends further into a locking member 422 and is fixed with a guide head 421. The distal end of the guide head 421 has a converging round head structure to facilitate its insertion and movement within the body. The position between the guide head 421 and the locking member 422 serves as the loading position for the interventional device. The compressed interventional device is located in this position and is limited and engaged with the locking member 422.

[0204] In one embodiment, an inner core 424 is provided inside the core tube 425. The distal end of the inner core 424 extends out to form a locking member 422 and is fixed with a guide head 421. The proximal extension length of the inner core 424 is not strictly limited. The position on the outer periphery of the inner core and between the guide head and the locking member serves as the loading position for the interventional device. The interventional device in a compressed state is in this position and is limited and engaged with the locking member 422. Since the core tube 425 does not extend to the loading position, the inner core 424 has a smaller outer diameter than the core tube 425, thus expanding the radial space of the loading position.

[0205] See Figure 5a and Figure 5b In some embodiments, the locking device is wire-controlled. The proximal end of the interventional device 500 has a connecting ear 501, which generally has a hanging hole or hook for threading the pull wire 4223. The locking device 422 has a locking hole 4221. The distal end of the locking rod 4224 engages with the locking hole 4221, and the proximal end can extend to the operating handle.

[0206] In the loaded state, the pull cable 4223 passes through the connecting lug 501 and is looped onto the locking bar 4224. Since the far end of the locking bar 4224 is inserted into the lock hole 4221, the pull cable 4223 can prevent the connecting lug 501 from disengaging from the lock 422. When release is required, the locking bar 4224 is pulled towards the near end and disengaged from the lock hole 4221, and the pull cable 4223 is also released, allowing the connecting lug 501 to disengage from the lock 422.

[0207] There are multiple connecting ears 501, and multiple pull wires 4223 can be configured. Each pull wire 4223 extends to the far end via a splitter 4222. In order to organize the wire bundle, a wire sleeve 4225 can be fitted around the core tube 425 to form an extension channel for the pull wire 4223.

[0208] The locking rod 4224 and the lock hole 4221 that work together form a locking mechanism. Multiple locking mechanisms can be configured as needed and arranged sequentially along the circumference of the lock 422.

[0209] See Figure 5c In some embodiments, the locking member 422 has one or more limiting grooves on its outer periphery. The interventional instrument has connecting ears that fit into the limiting grooves. The limiting grooves are used to axially limit the interventional instrument, allowing it to be released only after radial expansion. To prevent the connecting ears from accidentally dislodging or suddenly protruding outwards and injuring tissue during release, a pressure strip 423 that mates with each limiting groove is also fixed at the locking member 422. After loading, the pressure strip 423 is restrained by the sheath, restricting the connecting ears within the limiting grooves, further improving safety. During release, the flexible pressure strip 423 flips outwards, allowing the connecting ears to dislodge from the locking member 422.

[0210] The inner core 424 and the core tube 425 are both tubular structures. Since there is no need for axial relative movement between the core tube 425 and the inner core 424, they are nested together and welded together. Welding points can be set at one or more locations. If necessary, bushings can be added at the welding points to fill the radial gap between the two. The inner core 424 and the core tube 425 are welded to the bushings respectively, and the bushings can be made of the same material as the core tube 425.

[0211] One end of the core tube 425 is directly or indirectly fixed to the proximal side of the lock 422, and the other end extends toward the operating handle.

[0212] In one embodiment, for ease of bending, the core tube 425 includes a compliant section 4251 adjacent to the locking member 422, and a third extension section 4252 that is adjacent to the compliant section 4251 and extends proximally. The compliant section has less stiffness than the third extension section, i.e., it has better flexibility and is easier to bend.

[0213] In one embodiment, the compliant section 4251 is made of a hyaluronic acid tube or a spring tube (i.e., a tube with spirally extending reinforcing ribs in the tube wall interlayer), and its length ranges from 120 mm to 180 mm, for example, 150 mm.

[0214] The third extension section 4252 uses a hyaluronic acid tube or a steel cable tube (made of braided or stranded metal wire); the steel cable tube can be wrapped with a PTFE membrane for lubrication.

[0215] In other embodiments, the core tube 425 is a single piece of sodium hypochlorite tubing. The sodium hypochlorite tubing provides both axial support and radial bending capability. To control the bending direction of the compliant section 4251, the compliant section 4251 may have an axially extending reinforcing rib. This reinforcing rib is obtained by cutting a corresponding portion of the sodium hypochlorite tubing (the uncut or sparsely cut area becomes the reinforcing rib). The reinforcing rib may extend to the nearest end of the core tube 425, but since there is no significant bending requirement near the near end of the core tube 425, the reinforcing rib may also extend to the middle of the core tube 425 or slightly closer to the near end.

[0216] See Figure 7 , Figure 8 When cutting section 4251, the kerf width (i.e., laser spot diameter) is 0.1 to 1 mm, and the kerf spacing (i.e., the uncut portion between adjacent kerfs) is 0.1 to 1 mm; among them, an uncut portion extends along the axial direction to form a reinforcing rib 4253.

[0217] In some embodiments, the core tube, as the object to be bent, is configured such that the compliant segment has a smaller limiting radius of curvature after bending as it approaches the distal end. This allows the distal end of the core tube to better adapt to complex paths. Specifically, regarding the compliant segment, at least one of the following methods can be employed, for example:

[0218] The kerf width gradually changes in the conforming section, and the kerf width increases as it approaches the far end.

[0219] In the compliant segment, the suture spacing gradually changes, and the suture spacing becomes smaller as it approaches the far end.

[0220] In the compliant section, the stiffness (degree of bendability) gradually changes, and the stiffness decreases as it approaches the far end.

[0221] See Figures 9-11 The bending tube 410 is sleeved outside the core tube 425. The bending tube 410 includes a pulling section and a second extension section 413 from the far end to the near end. The pulling section is an integral structure and uses a hysteresis tube.

[0222] The distal end of the pull section extends to the proximal end of the adjacent locking element 422 and is fixed to the core tube 425. To prevent the pull section from being reversed during processing, different markings can be made at both ends of the pull section by means of drilling to identify the assembly orientation of the distal and proximal ends.

[0223] The traction segment, from distal to proximal, includes a first traction segment 411, a transition segment 414, and a second traction segment 412.

[0224] In this application, the bending tube 410 is located outside the core tube 425, that is, the active force applied during bending is on the outside, while the passive force being pulled is on the inside. This arrangement, with the active force on the inside and the passive force on the outside, allows for a larger bending angle.

[0225] The first tensioning section 411 is formed with a reinforcing rib 4111 by cutting, and the reinforcing rib 4111 is 180 degrees away from the reinforcing rib 4253 of the compliant section 4251 in the circumferential position.

[0226] The second traction segment 412 also adopts a cutting method. When cutting the first traction segment 411 and the second traction segment 412, the cutting suture width is 0.03~0.5mm and the suture spacing is 0.2mm~0.85mm respectively. The first traction segment 411 is located at the expected bending position and should be relatively soft and easier to bend. The second traction segment 412 is relatively hard, but in order to ensure a certain degree of flexibility so that it can be bent during transportation and packaging, and can bend according to blood vessels after entering the human body during surgery, a cutting method is adopted. In actual operation, the suture width and suture spacing can be adjusted according to the softness and hardness requirements of different segments.

[0227] The second tensioning section 412 has reinforcing ribs 4121 and 4122 formed by cutting. The two reinforcing ribs are radially opposite each other, that is, their circumferential positions are 180 degrees apart, and both are 90 degrees apart from the circumferential position of the reinforcing rib 4111 of the first tensioning section 411.

[0228] The transition section 414 is not cut. The transition section 414 connects the first tension section 411 and the second tension section 412, and also shares the tension stress at different positions in the circumferential direction.

[0229] The second extension section 413 has no special bending requirements and mainly bears the responsibility of transmitting tensile force. For example, it can be extended to the proximal end and connected to the operating handle by using a non-cut hyaluronic acid tube.

[0230] During the bending process, the first tension section 411 and the compliant section 4251 undergo significant bending. Therefore, when cutting the submersible tube, a bending angle >270° is generally required. The single reinforcing rib structure on each section ensures that it does not stretch under bending stress. The overlapping of the first tension section 411 and the compliant section 4251 results in moderate flexibility, facilitating bending and ensuring force transmission. Overall, the bending tube 410 is 5mm to 10mm longer than the core tube 425 to match the axial offset after bending. During bending, the core tube 425 and the sheath tube 300 are passive, while the bending tube 410 actively applies force.

[0231] See Figures 12-13 To adapt to changes in distal orientation during bending or passage within the body, the outermost sheath 300 has varying degrees of hardness and softness at different axial locations. From distal to proximal, the sheath 300 includes a loading section 310, a bending section 320, and a first extension section 330. During use, it primarily bends near the proximal side of the loading area adjacent to the insertion device 500, i.e., where the bending section 320 is located.

[0232] See Figures 14-15d One embodiment illustrates the nesting relationship of the sheath 300, the core tube assembly 420, and the bending tube 410, as well as the release process of the interventional device. Figure 15d The diagram also illustrates the approximate axial positional relationship of each segment in the sheath tube 300, core tube assembly 420, and bending tube 410. For each segment, the sheath tube 300 adopts a multi-layer composite structure, that is, for a certain segment, a multi-layer structure is adopted and different components are included in the processing. The structure and process of the sheath tube 300 are also improvements of this application.

[0233] See Figures 16-17d One embodiment illustrates the nesting relationship between the sheath 300 and the core tube assembly 420, as well as the release process of the interventional device. Figure 15dThe diagram also illustrates the approximate axial positional relationship of the segments in the sheath 300 and core tube assembly 420. For each segment, the sheath 300 employs a multi-layered composite structure; that is, for a given segment, a multi-layered structure is used, and different components are incorporated during processing. The structure and manufacturing process of the sheath 300 are also improvements of this application. In this embodiment, the core tube assembly 420 includes a core tube 425, on which a locking member 422 is fixed. The locking member 422 extends further from the distal end of the core tube 425, and a guide head 421 is fixed at its farthest end. The distal end of the guide head 421 has a converging rounded head structure to facilitate its insertion and movement within the body. The position between the guide head 421 and the locking member 422 serves as the loading position for the interventional device. The compressed interventional device is positioned in this position and is restrained and engaged by the locking member 422.

[0234] In one embodiment, an inner core 424 is provided inside the core tube 425. The distal end of the inner core 424 extends out to the locking member 422 and is fixed with a guide head 421. The distal end of the core tube 425 only extends to the locking member 422. The proximal extension length of the inner core 424 is not strictly limited. Since the core tube 425 does not extend to the loading position, the inner core 424 has a smaller outer diameter than the core tube 425, which expands the radial space of the loading position.

[0235] In one embodiment of this application, a sheath for delivering interventional devices is provided. The distal end of the sheath is a loading section 310 for receiving interventional devices. The loading section 310 has a multi-layer structure, which includes an inner liner tube 375, a metal tube (“partial”) and an outer membrane 380 from the inside out. The metal tube includes a main tube 350 and a head tube 340 that are connected to each other from the proximal end to the distal end.

[0236] The head end tube 340 includes a body section 346, a plurality of expansion plates 344 arranged circumferentially at intervals on the far end side of the body section, a first connector 343 on the proximal end side of the body section, and a second connector 351 on the far end side of the main body tube 350. The first connector 343 and the second connector 351 are interlocked and complementary in shape.

[0237] In one embodiment of this application, the portion of the sheath other than the loading section 310 is further improved and refined. In this embodiment, the sheath is divided into a loading section 310, a bending section 320 and a first extension section 330 in the axial direction from the distal end to the proximal end. The loading section 310 is used to house the interventional device 500. The sheath adopts a multi-layer structure, including an inner sheath 370, which is distributed in the bending section and the first extension section in the axial direction.

[0238] The inner liner tube 375 is connected to the distal end of the inner sheath tube 370, and the inner liner tube 375 is distributed in the loading section in the axial direction.

[0239] Metal tubes are wrapped around the distal part of the inner sheath tube and the outer periphery of the inner liner tube. The metal tubes are distributed in the bending section and the loading section in the axial direction. The main tube 350 and the head tube 340 are both located in the loading section.

[0240] The outer membrane 380 is wrapped around the outer periphery of the metal tube, and the outer membrane 380 is distributed in the bending section and the loading section in the axial direction.

[0241] Because the loading section 310 needs to enclose the interventional device, it has a larger diameter than the proximal portion of the sheath (i.e., the bendable section 320 and the first extension section 330).

[0242] Figure 18 The diagram illustrates some visible components of the sheath 300. The distal portion of the sheath 300 generally has at least three layers: the inner and outer layers are made of polymer material, and the middle layer is a metal tube. The middle layer employs a three-section joint structure, consisting of a head tube 340, a main tube 350, and an extension tube 360, sequentially joined from the distal to the proximal end. Axially, the head tube and main tube are located in the loading section, while the extension tube is located in the bendable section. In the above embodiment, the metal tube was also mentioned when describing the loading section 310. Since this refers to the loading section, it is part of the overall metal tube, including only the head tube 340 and the main tube 350. It can also be understood as a "part" of the overall metal tube, corresponding to the annotation in parentheses above.

[0243] The bendable section can be bent to change the orientation of the distal end of the sheath during delivery, while the first extension section mainly provides sufficient axial pushing and pulling force and has sufficient length to connect the operating handle.

[0244] The tip tube 340 is cut from a nickel-titanium alloy tube, while the main tube 350 and extension tube 360 ​​are cut from stainless steel tubes. Because the tip tube 340 and main tube 350 need to enclose the interventional device, they have a larger diameter than the extension tube 360. Figure 18 The axial position relationship is such that the connection between the main tube 350 and the extension tube 360 ​​is also flared and the diameter is changed accordingly.

[0245] See Figure 19a In one embodiment, the distal end of the head tube 340 has a plurality of spaced openings 341 along the circumferential direction, and an expansion piece 344 is located between two adjacent spaced openings. Each expansion piece 344 has a hollow area 345. In a preferred embodiment, the expansion pieces 344 are evenly arranged along the circumferential direction, and the number is 3 to 6, for example, 5.

[0246] Overall, the head tube 340 preferably adopts an integral structure, the body section 346 forms a developing area 342 in a hollowed-out manner for installing developing points, and the first connector 343 is T-shaped for docking with the main tube 350 and axially limiting it. Both the body section 346 and the first connector 343 have through holes 347 distributed on them, which can better fuse the polymer materials that serve as the inner and outer layers of the sheath.

[0247] The septum opening 341 is a strip-shaped notch, open at the distal end and closed at the proximal end. Because the tip tube 340 is made of an elastic metal material such as nickel-titanium alloy, each expansion piece 344 can be radially folded outwards. This allows it to adapt to the gradual deformation of the interventional device during release and prevents sudden ejection at the end of release. Furthermore, when retrieval is required, each expansion piece 344 radially folds outwards to form a flared opening, facilitating the gradual radial compression and retraction of the interventional device into the sheath 300. To achieve better elasticity, the tip tube 340 can be made of nickel-titanium alloy, with each expansion piece having both an axially extending, encircling state and a mutually distancing, folded-out state.

[0248] The hollow area 345 of the expansion piece 344 facilitates the deformation of the expansion piece and reduces the outward resistance. In one embodiment, the hollow area 345 is a strip hole that extends along the axial direction of the head end tube 340. On the same expansion piece, there are one, two or more strip holes.

[0249] In a preferred embodiment, the strip-shaped holes extend to a uniform width. Both ends of the strip-shaped holes have arc-shaped inner edges along their length. This prevents cracking caused by excessive stress concentration during deformation.

[0250] In one embodiment, each expansion piece 344 has a narrowing portion 348 at its proximal end, and the spacer opening has a corresponding widening portion at its proximal end, that is, corresponding to the narrowing portion 348.

[0251] To distribute stress, the inner edge of the widened section is made of a smooth curve, such as the teardrop-shaped large head.

[0252] In one embodiment, the spacer opening itself extends at a generally uniform width, except for the distal side which accommodates the chamfer of the expansion piece and the proximal side which is widened.

[0253] The width of the equal-width extension of the interval opening is approximately the same as the width of the strip hole. For example, the width of the strip hole is taken as the reference width, and the width of the equal-width extension of the interval opening is ±20% of the reference width.

[0254] To facilitate the outward folding of each expansion piece 344 at the narrowing portion 348 and reduce the deformation resistance on the proximal side of the narrowing portion, in one embodiment, the proximal side 349 of the strip hole extends beyond the narrowing portion of the expansion piece. In a preferred embodiment, the proximal side 349 of the strip hole extends beyond the narrowing portion of the expansion piece by 1 to 5 mm, for example, 1.5 to 3 mm.

[0255] To avoid safety hazards, in one embodiment, the distal end of the expansion piece has a smooth outer edge, for example, by using rounded corners, or by using an arc shape that protrudes distally.

[0256] See Figure 19b In one embodiment, each expansion piece 344 has a hollow area 345, which consists of multiple through holes spaced apart along the axial direction of the sheath tube. The total area of ​​the through holes on each expansion piece is less than 50% of the area of ​​the expansion piece. As can be seen in the figure, the area of ​​the through holes closer to the far end on the same expansion piece is larger. The through holes are circular or elliptical, and the number of through holes on the same expansion piece is 2 to 5.

[0257] and Figure 19a Similarly, in the corresponding embodiment, the body section 346 of the head tube forms a developing area 342 in a hollowed-out manner for installing developing points. The first connector 343 is T-shaped for docking with the main tube and axially limiting its position. Through holes 347 are distributed on both the body section 346 and the first connector 343, allowing for better fusion of the polymer materials in the inner and outer layers of the sheath. An interval opening 341 is formed between adjacent expansion pieces 344. The interval opening 341 is a strip-shaped notch, open at the distal end and closed at the proximal end. The expansion pieces 344 narrow towards the distal end, and an arc-shaped edge is used at the farthest end to improve safety.

[0258] To prevent the metal material in the middle layer from scratching the blood vessel wall, the outermost layer must at least wrap the head tube 340, the main tube 350, and the extension tube 360. The outermost outer membrane 380 can be made of polymer material. Since the metal part has a multi-segment structure, the outer membrane 380 also adopts a multi-segment splicing structure during processing and then melts it into one piece.

[0259] For example, along the axial direction of the sheath, the outer membrane 380 comprises multiple segments, each made of a different material, or at least both made of the same material.

[0260] In one embodiment, the strength of the outer film corresponding to the main tube 350 is greater than the strength of the outer film corresponding to the distal end of the head tube 340.

[0261] The inner layer includes an inner sheath tube 370 and an inner liner tube 375. The inner sheath tube 370 extends proximally on one side and extends to the junction of the main tube 350 and the extension tube 360 ​​on the other side. The inner sheath tube 370 extends further distally from the junction of the main tube 350 and the extension tube 360 ​​through the inner liner tube 375 until it reaches the distal end of the head tube 340. The inner liner tube 375 may be made of PTFE material.

[0262] The axial position of the distal portion of the extension tube 360 ​​corresponds to the compliant section 4251 and the first pulling section 411. The extension tube 360 ​​can also be cut to form reinforcing ribs.

[0263] See Figures 20-24 The inner sheath 370 itself adopts a multi-layer structure, consisting of a PTFE inner layer 3701, a braided layer 3702, a braided layer 3704, and an outer layer 3705 from the inside out. Two reinforcing ribs 3704 extending axially are fixedly wrapped between the braided layers 3702 and 3704.

[0264] One of the two reinforcing ribs 3704 is in the same circumferential position as the reinforcing rib 4253, while the other is 180 degrees away from the reinforcing rib 4253 in the same circumferential position.

[0265] The braided layers 3702 and 3704 do not require a distinct layered structure; they can be woven together and have reinforcing ribs sandwiched between them. The outer layer 3705 can be made of Pebax material.

[0266] A reinforcing rib 4253 is provided in the conforming section 4251, and a reinforcing rib 4111 is provided in the first tension section 411. The reinforcing ribs 4253 and 4111 are circumferentially offset by 180 degrees.

[0267] The sheath shown in the cross-sectional view only shows the extension tube 360. The extension tube 360 ​​may be provided with a reinforcing rib 3601. The reinforcing rib 3601 and the reinforcing rib 4253 are on the same side of the radial direction, that is, in the same circumferential position.

[0268] In other embodiments, the extension tube 360 ​​is provided with two reinforcing ribs, namely reinforcing rib 3601 and reinforcing rib 3602. Reinforcing rib 3601 and reinforcing rib 4253 are located on the same side of the radial direction, that is, at the same circumferential position. Reinforcing rib 3602 and reinforcing rib 4111 are located on the same side of the radial direction, that is, at a circumferential position 180 degrees different from that of reinforcing rib 4253.

[0269] The inner sheath 370 exists in both the bending section 320 and the first extension section 330. Because the bending section 320 has a larger bending angle during bending, the inner sheath 370 has different strengths in the bending section 320 and the first extension section 330. The inner sheath 370 is softer in the bending section 320. For example, the outer layer 3705 of the inner sheath 370 in the bending section 320 uses 30-59D Pebax, while the outer layer 3705 of the inner sheath 370 in the first extension section 330 uses 60-90D Pebax. The braided layers and the PTFE inner layer 3701 at different locations of the inner sheath 370 can use the same configuration. See also... Figures 25-34 One embodiment of this application provides a method for processing a sheath 300, comprising:

[0270] Step S100: A flared portion is formed at the distal end of the inner sheath.

[0271] The distal end 371 of the inner sheath can be heated and softened, and combined with the inserted mandrel 372, the distal end 371 can be enlarged to form a flared portion 374. A portion of the outer periphery of the mandrel 372 can be processed into a frustum section 373 according to the expected shape of the flared portion 374.

[0272] Step S200: Fit the inner liner tube onto the outer periphery of the flared part;

[0273] Take a PTFE inner tube 375. The end of the inner tube 375 has ear pieces arranged at intervals along the circumference. The area between the ear pieces is the cutting area 376. Wrap this end around the flared part 374, and then wrap it with a fixing sleeve 377 and heat-melt it to connect the inner tube 375 to the far end 371 of the inner sheath tube.

[0274] The fixing sleeve 377 and the flared part 374 are made of the same material, such as Pebax, while the cutting area 376 facilitates the fusion of the fixing sleeve 377 and the flared part 374, ensuring the connection strength of the inner liner tube 375.

[0275] Step S300: A metal tube is fitted around the outer periphery of the inner sheath and the inner liner.

[0276] The extension tube 360, main tube 350, and head tube 340 are connected in sequence, and the adjacent tubes are axially limited by hooks, buckles, or other means. The head tube 340 is made of nickel-titanium alloy, while the extension tube 360 ​​and main tube 350 can be made of stainless steel.

[0277] The proximal end of the head tube 340 has a T-shaped first connector 343, and the distal end of the main tube 350 has a T-shaped second connector 351. The first connector 343 and the second connector 351 are complementary in shape and cooperate with each other for axial limiting.

[0278] The main tube 350 has a constriction section 352 on its proximal side, which connects to the extension tube 360 ​​via the constriction section 352. The connection can be made using conventional hooks or clips. The tube wall of the main tube 350 has hollowed-out areas 353 and 354, and between them are axially extending guide ribs 355. The guide ribs 355 can restrict the bending direction of the sheath tube 300. There are two guide ribs 355 arranged radially opposite each other.

[0279] The extension tube 360, main tube 350, and head end tube 340 are sequentially connected and then fitted onto the outside of the inner sheath tube 370 and inner liner tube 375. The position of the flared part 374 corresponds to the axial position of the constricted part 352. The inner liner tube 375 is slightly longer than the head end tube 340. The inner liner tube 375 is also cut at the position corresponding to the spacer opening 341 to accommodate the deformation of the expansion piece.

[0280] Step S400 involves segmentally wrapping the metal tube with an outer material, with each segment of the outer material being heat-melted to form an overall outer film. Specifically, this includes:

[0281] Step S410: Wrap the first connecting sleeve 381 around the joint of the main tube 350 and the head tube 340, wrap the head tube 340 with the head sleeve 382, ​​and heat-melt fix the first connecting sleeve 381 and the head sleeve 382.

[0282] The head end sleeve 382 is also slightly longer than the head end tube 340 and roughly aligned with the inner liner tube 375. Then, the first connecting sleeve 381 and the head end sleeve 382, ​​together with the corresponding positions of the inner liner tube 375, are heat-fused to fix the joint between the main body tube 350 and the head end tube 340, as well as the inner and outer parts of the head end tube 340.

[0283] First lining piece 383 and second lining piece 384 are placed in the hollowed-out areas 353 and 354, and then heat-fused to the corresponding positions of the inner lining tube 375. The first lining piece 383 and second lining piece 384 are then inserted into and filled into the corresponding hollowed-out areas.

[0284] Step S420: Wrap the outer casing 385 around the main body tube 350 and fix it with heat fusion.

[0285] The distal end of the main body sleeve 385 is roughly aligned with the proximal end of the first connecting sleeve 381, and the proximal end of the main body sleeve 385 wraps around the joint of the extension tube 360 ​​and the main body tube 350.

[0286] The head end jacket 382 requires better flexibility and can be made of materials such as TPU. The first connecting sleeve 381, the first liner 383, the second liner 384, and the main body jacket 385 can be made of materials with better strength, such as Pebax. The first liner 383 and the second liner 384 can be thinner than the main body jacket 385. For example, the thickness of the first liner 383 and the second liner 384 is about 0.15mm, while the thickness of the main body jacket 385 can be increased to 0.35mm.

[0287] In addition, the first connecting sleeve 381 requires greater strength, so a relatively hard material can be selected, such as 60-72D. The main outer sleeve 385 mainly provides wrapping and protection, and its hardness can be appropriately reduced, for example, 40-55D. In step S430, the second connecting sleeve 386 is wrapped around the inner sheath 370 at the proximal end of the extension tube 360 ​​and the adjacent part, and the second connecting sleeve 386 is fixed by heat fusion.

[0288] Step S440: Wrap the connecting sleeve 387 around the outer periphery of the extension tube 360 ​​and fix it by heat fusion.

[0289] The axial position of the connecting sleeve 387 is such that the proximal end is connected to the second connecting sleeve 386, and the distal end is connected to the main body outer sleeve 385.

[0290] The second connecting sleeve 386 uses Pebax or similar materials for better strength. The connecting sleeve 387, being located at the bend, requires better flexibility and can be made of materials such as TPU. In addition, the connecting sleeve 387 can prevent the internal metal tube from directly contacting and scratching blood vessels, and also serves as a seal.

[0291] The materials wrapped around the extension tube 360, the main tube 350, and the head tube 340 are eventually fused together to form an outer film 380. Finally, the part of the head tube 340 that extends beyond the end is heat-fused to close the opening. The part corresponding to the interval opening 341 can also be cut to accommodate the possible deformation of the interval opening 341, or to utilize the elasticity of the material of the head sleeve 382 itself.

[0292] See Figures 35-40 The bending adjustment system of this application can actively change the orientation of the distal part by pulling the bending adjustment tube at the operating handle during use, which can better adapt to the delivery of complex paths. Taking the insertion of interventional device 500 into the aortic valve 600 as an example, when passing through the aortic arch, the distal end of the sheath assembly is pointed to and positioned at the aortic valve 600 by the bending adjustment. Since the bending adjustment tube pulls the core tube assembly, the interventional device loaded in the core tube assembly does not change its orientation when the sheath is withdrawn to release the interventional device, which can avoid the risk of misalignment during the release process.

[0293] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification. When technical features of different embodiments are embodied in the same drawing, it can be regarded as the drawing also disclosing examples of combinations of the various embodiments involved.

[0294] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A sheath for delivering interventional instruments, characterized in that, The sheath consists of a loading section, a bending section, and a first extension section in axial direction from the distal end to the proximal end. The distal end of the sheath is a loading section for receiving interventional instruments, and the diameter of the loading section is larger than that of the flexible section and the first extension section. The sheath has a multi-layer structure, consisting of an inner layer, a metal tube, and an outer membrane from the inside out. The metal tube consists of a head tube, a main tube, and an extension tube connected sequentially from the distal end to the proximal end. In the axial direction, the head tube and the main tube are distributed in the loading section, and the extension tube is distributed in the bending section. The inner layer includes an inner sheath and an inner liner, the inner liner being connected to the distal end of the inner sheath. The inner sheath is distributed axially in the bendable section and the first extension section, the inner sheath being softer in the bendable section than in the first extension section. The outer film is wrapped around the outer periphery of the metal tube, and the outer film is distributed axially in the bending section and the loading section; The head end tube includes a body section and a plurality of elastic expansion plates arranged at circumferential intervals on the distal side of the body section.

2. The sheath for delivering interventional instruments as described in claim 1, characterized in that, Each expansion piece has a hollow area; the hollow area is a plurality of through holes arranged at intervals along the axial direction of the sheath tube, and the total area of ​​the through holes on each expansion piece is less than 50% of the area of ​​the expansion piece.

3. The sheath for delivering interventional instruments as described in claim 2, characterized in that, The hollowed-out area is a strip-shaped hole that extends axially along the head end tube.

4. The sheath for delivering interventional instruments as described in claim 1, characterized in that, There is a gap between two adjacent expansion pieces, and each expansion piece has a narrowing portion at the proximal end. The gap has a widening portion at the proximal end that corresponds to the narrowing portion.

5. The sheath for delivering interventional instruments as described in claim 4, characterized in that, The inner edge of the widened portion is a smooth curve.

6. The sheath for delivering interventional instruments as described in claim 4, characterized in that, The central region of the interval opening extends at a constant width along its length; the width of the equally wide extended portion of the interval opening is approximately the same as the width of the strip hole.

7. The sheath for delivering interventional instruments as described in claim 1, characterized in that, The proximal end of the body segment has a first connector, and the distal end of the main tube has a second connector. The first connector and the second connector are interlocked and complementary in shape.

8. A sheath assembly, comprising a slidingly nested sheath and a sheath core assembly, the sheath core assembly comprising a core tube, the distal end of which is fitted with a locking element for connecting an interventional device; characterized in that, The sheath is the sheath for delivering interventional instruments as described in any one of claims 1 to 6.

9. The sheath assembly as claimed in claim 8, characterized in that, The sheath-core assembly also includes a bending tube sleeved around the core tube. The distal ends of the bending tube and the core tube are fixedly connected to each other, while their proximal ends can slide relative to each other.

10. The sheath assembly as claimed in claim 9, characterized in that, The sheath-core assembly also includes a bending tube located inside the core tube. The distal ends of the bending tube and the core tube are fixedly connected to each other, while their proximal ends can slide relative to each other.

11. The sheath assembly as claimed in claim 9 or 10, characterized in that, The core tube includes a compliant section adjacent to the locking element and a third extension section that is connected to the compliant section and extends proximally, wherein the compliant section is made of hyaluronic acid tube and has a length ranging from 120 to 18 mm, and the third extension section is made of steel cable tube or hyaluronic acid tube.

12. The sheath assembly as claimed in claim 11, characterized in that, The bending tube includes a pulling section and a second extension section from the distal end to the proximal end. The pulling section is an integral structure and uses a hysteresis tube. The pulling section includes a first pulling section, a transition section and a second pulling section from the distal end to the proximal end. The first pulling section has higher flexibility than the second pulling section. The length ratio of the first pulling section to the length of the compliant section is 1:0.7~1.

5.

13. The sheath assembly as claimed in claim 12, characterized in that, The compliant section is formed by cutting to create an axially extending first reinforcing rib; the cut width of the compliant section is 0.1~1mm, and the cut spacing is 0.1~1mm.

14. The sheath assembly as claimed in claim 13, characterized in that, In the compliant segment, the closer to the far end, the smaller the limiting radius of curvature after bending.

15. The sheath assembly as claimed in claim 13, characterized in that, The first tensioning section is formed by cutting to create an axially extending second reinforcing rib, and the circumferential position of the second reinforcing rib differs from that of the first reinforcing rib by 180 degrees.

16. The sheath assembly as claimed in claim 15, characterized in that, The width of the cut in the first pulling section is 0.03~0.5mm, and the spacing between cuts is 0.2mm~0.85mm.

17. The sheath assembly as claimed in claim 15, characterized in that, The second tensioning section is formed by cutting to create two axially extending third reinforcing ribs. The two third reinforcing ribs are radially opposite each other and are 90 degrees apart from the circumferential position of the first reinforcing rib.

18. The sheath assembly as claimed in claim 17, characterized in that, The second pulling section has a cutting slit width of 0.03~0.5mm and a slit spacing of 0.2mm~0.85mm; the transition section is a complete circumferential uncut structure.

19. The sheath assembly as claimed in claim 13, characterized in that, The inner sheath adopts a multi-layer structure, with a fourth reinforcing rib extending axially in the interlayer. There are two fourth reinforcing ribs, one of which is located at the same circumferential position as the first reinforcing rib, and the other is located 180 degrees away from the first reinforcing rib in the circumferential position.

20. The sheath assembly as claimed in claim 13, characterized in that, The extension tube is made of sodium hypochlorite tube, and a fifth reinforcing rib extending axially is provided inside the extension tube. The fifth reinforcing rib is one and is located in the same circumferential position as the first reinforcing rib; or there are two fifth reinforcing ribs, one of which is located in the same circumferential position as the first reinforcing rib, and the other is located 180 degrees away from the first reinforcing rib in the circumferential position.

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