Sheath assembly

Abstract

Provided is a processing method for a sheath tube (300) for delivering an interventional device (500) into a body, the processing method comprising: step S100, providing an inner sheath tube (370) and processing a flared portion (374) at a distal end portion (370A) of the inner sheath tube (370); step S200, sleeve-fixing an inner liner tube (375) on the periphery of the flared portion (374); step S300, sleeve-fitting a metal tube (375) on the periphery of the distal end portion (370A) of the inner sheath tube (370) and the periphery of the inner liner tube (375); step S400, using an outer covering material to cover the outer surface of the metal tube (375) in sections, and heat-melting each section of the outer covering material to form an outer covering film (380) as a whole. The processing method of the sheath tube (300) further ensures corresponding performance for a sheath tube (300) with a complex structure through the processing method.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a sheath assembly for delivering an interventional device. Background Art

[0002] An interventional device delivery system typically includes a sheath core assembly and a sheath tube that slides over the sheath core assembly. The two together form the sheath tube assembly, with the distal end capable of entering the human vascular system and the proximal end connected to an operating handle. Due to the tortuous nature of the human vascular system and considerations for long-distance operation, the distal end needs to be adjusted and controlled to move it to the target position. This places dual requirements on the sheath tube for axial support and bendability. Furthermore, the location and method of force applied during bending also affect safety and operational control to a certain extent.

[0003] It is necessary to further optimize the structure and processing method for sheaths with complex layer structures. Summary of the Invention

[0004] The present application provides a method for processing a sheath tube, which further ensures corresponding performance of a sheath tube with a complex structure through the processing method.

[0005] The present application provides a method for processing a sheath tube, wherein the sheath tube is used to deliver an interventional device into the body, and the method for processing the sheath tube comprises:

[0006] Step S100, providing an inner sheath tube and processing a flared portion at the distal end of the inner sheath tube;

[0007] Step S200, sleeve-fitting and fixing the liner pipe on the outer periphery of the flared portion;

[0008] Step S300, sleeve a metal tube on the outer periphery of the distal end of the inner sheath tube and the outer periphery of the inner liner tube;

[0009] Step S400: using outer covering materials to cover the metal tube in sections, and heat-melting each section of outer covering materials to form an outer covering film as a whole.

[0010] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution. They are merely further supplements or optimizations. Under the premise that there are no technical or logical contradictions, each optional method can be combined separately for the above-mentioned overall solution, or multiple optional methods can be combined.

[0011] The sheath of the present application is divided into a loading section, a bending section, and a first extension section in the axial direction from the distal end to the proximal end, wherein the loading section is used to accommodate the interventional instrument. The sheath adopts a multi-layer structure, including:

[0012] An inner sheath tube, which is distributed in the bending section and the first extension section in the axial direction;

[0013] An inner liner tube, the inner liner tube being connected to the distal end of the inner sheath tube and being distributed in the loading section in the axial direction;

[0014] A metal tube, the metal tube being wrapped around the distal end of the inner sheath tube and the outer periphery of the inner liner tube, and the metal tube being distributed in the bending section and the loading section in the axial direction;

[0015] The outer membrane is wrapped around the outer periphery of the metal tube and is distributed in the bending section and the loading section in the axial direction.

[0016] Optionally, the metal tube includes a head end tube, a main body tube and an extension tube that are connected in sequence from the distal end to the proximal end, wherein in the axial direction, the head end tube and the main body tube are both distributed in the loading section, and the extension tube is distributed in the bending section.

[0017] Optionally, the extension tube is a hypotube.

[0018] Optionally, the inner sheath tube adopts a multi-layer structure, and a fourth reinforcing rib extending axially is provided in the interlayer. There are two fourth reinforcing ribs, one of which is at the same circumferential position as the first reinforcing rib, and the other fourth reinforcing rib is 180 degrees out of circumferential position with the first reinforcing rib.

[0019] Optionally, the distal end of the fourth reinforcing rib extends to the proximal end of the extension tube or the distal end of the extension tube.

[0020] Optionally, a fifth reinforcing rib extending axially is provided in the extension tube, and there is one fifth reinforcing rib, which 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 fifth reinforcing rib is 180 degrees out of circumferential position with the first reinforcing rib.

[0021] Optionally, the head end tube and the main body tube are connected to each other by using connectors with complementary shapes, and the main body tube and the extension tube are connected to each other by a hook.

[0022] Optionally, two hollow areas are distributed on the tube wall of the main tube, and two guide ribs extending axially and arranged radially opposite to each other are distributed between the two hollow areas.

[0023] Optionally, along the axial direction of the sheath, the outer membrane includes multiple sections, each section is made of a different material, or at least two sections are made of the same material.

[0024] Optionally, the outer membrane strength corresponding to the main body tube is greater than the outer membrane strength corresponding to the distal end of the head end tube.

[0025] Optionally, the main body tube and the head end tube are cut from metal tubes of different materials.

[0026] Optionally, each expansion piece has a hollow area.

[0027] Optionally, the expansion pieces are evenly arranged along the circumferential direction, and the number thereof is 3 to 6.

[0028] Optionally, the first connector is T-shaped.

[0029] Optionally, the main body segment is hollowed out to form a developing area for installing a developing point.

[0030] Optionally, through holes are distributed on the main body section and the first connector, and the inner lining tube and the outer membrane are heat-fused to each other at the through holes.

[0031] Optionally, the hollow area is a plurality of through holes spaced apart along the axial direction of the sheath tube, and the total area of ​​the through holes on each expansion sheet is less than 50% of the area of ​​the expansion sheet.

[0032] Optionally, on the same expansion sheet, the through hole closer to the distal end has a larger area.

[0033] Optionally, the through holes are circular or elliptical, and the number of through holes on the same expansion sheet is 2 to 5.

[0034] Optionally, the hollow area is a strip-shaped hole, and the strip-shaped hole extends axially along the head end tube.

[0035] Optionally, there are two strip-shaped holes on the same expansion piece.

[0036] Optionally, the strip-shaped holes extend with equal width.

[0037] Optionally, both ends of the strip-shaped hole in the length direction are arc-shaped inner edges.

[0038] Optionally, there is a spacing opening between two adjacent expansion pieces, each expansion piece has a narrowing portion at its proximal end, and the spacing opening has a widening portion at its proximal end corresponding to the narrowing portion.

[0039] Optionally, the inner edge of the widened portion is a smooth curve.

[0040] Optionally, the middle region of the spacing opening in the length direction extends with equal width.

[0041] Optionally, the width of the equal-width extension portion of the interval opening is substantially the same as the width of the strip-shaped hole.

[0042] Optionally, the proximal end side of the strip-shaped hole passes over the narrowed portion of the expansion piece.

[0043] Optionally, the proximal end side of the strip-shaped hole exceeds the narrowed portion of the expansion piece by 1 to 5 mm.

[0044] Optionally, the distal end of the expansion piece has a smooth outer edge.

[0045] Optionally, the sheath tube is composed of the loading section, the bending section and the first extension section from the distal end to the proximal end in the axial direction; the proximal end of the liner tube is connected to the inner sheath tube, and the inner sheath tube is distributed in the bending section and the first extension section in the axial direction; the proximal end of the main body tube is connected to the extension tube made of metal, and the extension tube is distributed in the bending section in the axial direction, and the outer membrane also extends to the proximal end and wraps around the outer circumference of the extension tube.

[0046] Optionally, the head end tube is cut from a nickel-titanium alloy tube, and the main tube and the extension tube are cut from a stainless steel tube.

[0047] Optionally, the head end tube is made of nickel-titanium alloy, and each expansion piece has a surrounding state extending along the axial direction of the sheath tube and an everted state away from each other.

[0048] The sheath tube may be the sheath tube of the present application, that is, the present application further provides a method for processing the sheath tube, comprising:

[0049] Step S100, forming a flared portion at the distal end of the inner sheath;

[0050] Step S200, sleeve-fitting and fixing the liner pipe on the outer periphery of the flared portion;

[0051] Step S300, sleeve the metal tube on the outer periphery of the inner sheath tube and the inner liner tube;

[0052] Step S400: using outer covering materials to cover the metal tube in sections, and heat-melting the sections of outer covering materials to form the outer covering film as a whole.

[0053] Optionally, in step S200, the proximal end of the liner tube is provided with a plurality of ear pieces spaced apart along the circumferential direction, the plurality of ear pieces are overlapped and wrapped around the outer periphery of the flared portion, and then the plurality of ear pieces are wrapped with a fixing sleeve and fixed by hot melting.

[0054] Optionally, 3 to 6 ears are evenly arranged along the circumference.

[0055] Optionally, the inner lining tube is made of PTFE.

[0056] Optionally, the fixing sleeve is made of Pebax material.

[0057] Optionally, step S400 specifically includes:

[0058] Step S410: Wrap a first connecting sleeve around the butt joint of the main tube and the head end tube, wrap a head end outer sleeve around the head end tube, and fix the first connecting sleeve and the head end outer sleeve by hot-melt;

[0059] Step S420, wrapping the main body jacket around the outer periphery of the main body tube and fixing it with hot melt;

[0060] Step S430, wrapping a second connecting sleeve around the inner sheath at the proximal end of the extension tube and adjacent portions thereof, and fixing the second connecting sleeve by heat-melting;

[0061] Step S440: Wrap the connecting sleeve around the outer periphery of the extension tube and fix it with hot melt.

[0062] Optionally, the main tube has hollow areas distributed at intervals, and guide ribs are formed between adjacent hollow areas. In step S420, before wrapping the main outer jacket around the main tube, linings are placed in each hollow area and fixed by hot melting.

[0063] Optionally, the lining is made of Pebax material.

[0064] Optionally, the head end jacket and the connecting sleeve are made of TPU material.

[0065] Optionally, the first connecting sleeve, the second connecting sleeve and the main body jacket are all made of Pebax material.

[0066] The present application also provides a sheath tube assembly, comprising a sheath tube and a sheath core assembly that are slidably nested, the sheath core assembly comprising a core tube, a locking member for connecting an interventional instrument being installed at the distal end of the core tube; the sheath tube is located at the periphery of the sheath core assembly and is the sheath tube described in the present application, the sheath tube being divided into a loading section, a bending section, and a first extension section in the axial direction from the distal end to the proximal end, wherein the loading section is used to accommodate the interventional instrument, and the sheath tube adopts a multi-layer structure, comprising:

[0067] An inner sheath tube, which is distributed in the bending section and the first extension section in the axial direction;

[0068] An inner liner tube, the inner liner tube being connected to the distal end of the inner sheath tube and being distributed in the loading section in the axial direction;

[0069] A metal tube, the metal tube being wrapped around the distal end of the inner sheath tube and the outer periphery of the inner liner tube, and the metal tube being distributed in the bending section and the loading section in the axial direction;

[0070] The outer membrane is wrapped around the outer periphery of the metal tube and is distributed in the bending section and the loading section in the axial direction.

[0071] According to the need for bending adjustment, the sheath-core assembly may further include a bending adjustment tube, which is sleeved on the outer circumference of the core tube. The distal ends of the bending adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of the two can slide relative to each other.

[0072] The present application also provides an interventional instrument delivery system having opposite distal and proximal ends, the delivery system comprising an operating handle at the proximal end and a sheath assembly connected to the operating handle and extending toward the distal end, the sheath assembly comprising a sheath and a sheath core assembly;

[0073] The sheath-core assembly includes a core tube, a locking piece fixed to the distal end of the core tube for connecting to an interventional instrument, and a bend adjustment tube sleeved on the outer circumference of the core tube. The distal ends of the bend adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of the two can slide relative to each other and both extend to connect to the operating handle;

[0074] The sheath tube is slidably fitted on the outer periphery of the sheath core assembly. The distal end of the sheath tube is a loading section for accommodating interventional instruments. The loading section adopts a multi-layer structure, which includes an inner lining tube, a metal tube and an outer membrane from the inside to the outside. The proximal end of the sheath tube extends and is connected to the operating handle.

[0075] The operating handle, sheath tube and sheath-core assembly in the delivery system may adopt at least one of the operating handle, sheath tube and sheath-core assembly of the present application.

[0076] The present application further improves the processing method of the sheath tube and meets the performance requirements of each component. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a schematic diagram of the structure of the conveying system of this application;

[0078] Figure 2 for Figure 1 Exploded view of the conveying system;

[0079] Figure 3 for Figure 1 Schematic diagram of the internal structure of the middle operating handle;

[0080] Figure 4 for Figure 1 Exploded view of the operating handle;

[0081] Figure 5a This is a schematic structural diagram of a core tube assembly in an embodiment of the present application in which the locking element adopts a wire control method;

[0082] Figure 5b for Figure 5a Schematic diagram of the cooperation between the central locking piece and the access device;

[0083] Figure 5c This is a structural diagram of a core tube assembly in one embodiment of the present application;

[0084] Figure 6 This is a schematic structural diagram of an adjustable elbow in one embodiment of the present application;

[0085] Figure 7 This is a structural diagram of a core tube (compliant section) in one embodiment of the present application;

[0086] Figure 8 for Figure 7 Schematic diagram of the structure of the core tube (compliant section) from another angle;

[0087] Figure 9 This is a schematic structural diagram of an adjustable elbow in one embodiment of the present application;

[0088] Figure 10 for Figure 9 Schematic diagram of the structure of the center adjustment elbow at another angle;

[0089] Figure 11 for Figure 9 Expanded view of the center adjustment elbow;

[0090] Figure 12 This is a schematic structural diagram of a sheath tube in one embodiment of the present application;

[0091] Figure 13 for Figure 5c 、 Figure 6 、 Figure 12 Schematic diagram of the structure after the components are assembled;

[0092] Figure 14 This is a cross-sectional view of a sheath assembly in one embodiment of the present application;

[0093] Figure 15a for Figure 14 Schematic diagram of the structure after the interventional device is loaded;

[0094] Figure 15b for Figure 15a Schematic diagram of the structure of the interventional device when it is half released;

[0095] Figure 15c for Figure 15a Schematic diagram of the structure of the interventional device after it is fully released;

[0096] Figure 15d This is a schematic diagram of the relative relationship between the axial sections of each pipe fitting in one embodiment of the present application;

[0097] Figure 16 This is a cross-sectional view of a sheath tube and an inner core assembly in one embodiment of the present application;

[0098] Figure 17a for Figure 16 Schematic diagram of the structure after the interventional device is loaded;

[0099] Figure 17b for Figure 17a Schematic diagram of the structure of the interventional device when it is half released;

[0100] Figure 17c for Figure 17a Schematic diagram of the structure of the interventional device after it is fully released;

[0101] Figure 17d This is a schematic diagram of the relative relationship between the axial sections of each pipe fitting in one embodiment of the present application;

[0102] Figure 18 It is an indicator diagram of each component in the sheath;

[0103] Figure 19a Schematic diagram of the structure of the head end tube;

[0104] Figure 19b Schematic diagram of the expanded structure of the head end tube in another embodiment;

[0105] Figure 20 A schematic diagram of the distal portion of the delivery system of the present application;

[0106] Figure 21 for Figure 20 Cross-sectional view of the inner sheath at the CC site;

[0107] Figure 22 for Figure 21 A magnified view of part A in the middle;

[0108] Figure 23 for Figure 20 Cross-sectional view of the middle BB area;

[0109] Figure 24 for Figure 20 A cross-sectional view of another embodiment at the BB portion;

[0110] Figures 25 to 34 Schematic diagram of components and related changes involved in the sheath tube processing process in one embodiment of the present application;

[0111] Figure 35 This is a schematic diagram of the distal end changes when the conveying system of this application is bent;

[0112] Figures 36 to 40 This is a schematic diagram of the state changes of the conveying system of this application in different processes in the usage scenario.

[0113] The reference numerals in the figures are described as follows:

[0114] 100. Operating handle;

[0115] 110. Bending adjustment assembly; 111. Second support; 112. Second driving member; 113. Second connecting member; 114. Guide strip; 115. Guide groove; 116. Operation port; 117. Force-applying portion; 118. Luer connector;

[0116] 120, control assembly; 121, first support body; 122, first driving member; 123, first connecting member; 124, guide key; 125, guide bar hole; 126, lock hole;

[0117] 130, front handle; 131, slide key; 132, slide slot;

[0118] 200, catheter;

[0119] 300, sheath; 310, loading section; 320, bending section; 330, first extension section;

[0120] 340, head end tube; 341, spacer opening; 342, developing area; 343, first connector; 344, expansion piece; 345, hollow area; 346, main body section; 347, through hole; 348, narrowing portion; 349, proximal side of the strip hole;

[0121] 350, main tube; 351, second connector; 352, closing portion; 353, hollow area; 354, hollow area; 355, guide rib;

[0122] 360, extension tube; 3601, reinforcement rib (fifth reinforcement rib); 3602, reinforcement rib (fifth reinforcement rib);

[0123] 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, truncated cone section; 374, flared portion; 375, inner liner; 376, cutting area; 377, fixing sleeve;

[0124] 380, outer membrane; 381, first connecting sleeve; 382, ​​head end jacket; 383, first lining; 384, second lining; 385, main body jacket; 386, second connecting sleeve; 387, connecting sleeve;

[0125] 400, sheath core assembly;

[0126] 410, bending adjustment tube; 411, first pulling section; 4111, reinforcing rib (second reinforcing rib); 412, second pulling section; 4121, reinforcing rib (third reinforcing rib); 4122, reinforcing rib (third reinforcing rib); 413, second extension section; 414, transition section;

[0127] 420, core tube assembly; 421, guide head; 422, lock piece; 4221, lock hole; 4222, distribution plate; 4223, pull wire; 4224, lock rod; 4225, threading sleeve; 423, pressure strip; 424, inner core; 425, core tube; 4251, compliance section; 4252, third extension section; 4253, reinforcement rib (first reinforcement rib);

[0128] 500. Interventional device; 501. Connecting ear;

[0129] 600. Aortic valve. DETAILED DESCRIPTION

[0130] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0131] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be an intermediate component. When a component is referred to as being "disposed on" another component, it may be directly disposed on the other component or there may be an intermediate component.

[0132] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are intended only to describe specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0133] See also Figures 1 to 4 In one embodiment of the present application, a delivery system is provided, having relative distal and proximal ends. The delivery system includes an operating handle 100 at the proximal end and a sheath tube 300 and a sheath core assembly 400 connected to the operating handle 100 and extending toward the distal end. The sheath tube 300 is slidably fitted on the outer periphery of the sheath core assembly 400.

[0134] The sheath-core assembly includes a core tube and a locking piece fixed at the distal end of the core tube for connecting to an interventional device. The locking piece can have a variety of different structural forms, for example, a groove form is used to connect to the connecting ear on the stent, or a radially outward protruding convex head form is used, or a wire control method is used to connect to the stent using a long wire or a wire loop. Regardless of which form is used, its purpose is to achieve connection with the connecting ear of the stent.

[0135] In some embodiments, the sheath-core assembly further comprises a bend adjustment tube sleeved on the outer periphery of the core tube. The distal ends of the bend adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of both extend to be connected to the operating handle and can slide relative to each other.

[0136] In some embodiments, the sheath-core assembly further comprises a bending adjustment tube located inside the core tube. The distal ends of the bending adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of the two can slide relative to each other.

[0137] Regardless of the internal and external relationship between the core tube and the bend adjustment tube, relative movement is required at the proximal end. Generally speaking, when adjusting the bend, the proximal end of the core tube is kept unchanged, or the proximal end of the core tube is used as a reference. When the proximal end of the bend adjustment tube is pulled, the difference in the internal and external relationship between the core tube and the bend adjustment tube can result in different contact points between the two at the turning point. The following embodiments and accompanying drawings mainly use the bend adjustment tube on the outside as an example. Regarding the structure of the operating handle, the proximal ends of the core tube and the bend adjustment tube can be adjusted accordingly according to the internal and external relationship between the core tube and the bend adjustment tube, so that the proximal ends of the two can move relative to each other.

[0138] In other embodiments, the delivery system may further include a catheter 200 fixed relative to the operating handle 100. The catheter 200 is used to establish a channel to prevent the sheath 300 from damaging tissues in the body during reciprocating motion. The interventional device is loaded into the sheath-core assembly 400 and, wrapped in the sheath 300, enters the body along with the catheter 200. The sheath 300 can then move axially relative to the other two to achieve the release of the interventional device and, when necessary, the retrieval operation.

[0139] The bending adjustment is mainly achieved by operating the handle 100.

[0140] In one embodiment, the operating handle 100 mainly includes a control component 120 , a bending adjustment component 110 and a front handle 130 .

[0141] The control component 120 includes a first support body 121, a first driving member 122 is rotatably sleeved on the outer periphery of the first support body 121, and a guide bar hole 125 extending axially is opened on the side wall of the first support body 121. A first connecting member 123 is slidably installed inside the first support body 121, and a guide key 124 extending from the guide bar hole 125 is provided on the first connecting member 123. The inner wall of the first driving member 122 has a threaded structure that cooperates with the guide key 124.

[0142] The first support body 121 is roughly cylindrical and can adopt an integrated or radially interlocked split structure. When the first driving member 122 rotates, the guide key 124 drives the first connecting member 123 to slide inside the first support body 121, and due to the limitation of the guide bar hole 125, the first connecting member 123 does not rotate, that is, it only moves axially.

[0143] The front handle 130 is fixedly connected to the first support body 121 , the proximal end of the catheter 200 is fixedly plugged into the front handle 130 , the proximal end of the sheath 300 is fixedly mounted on the first connector 123 , and the sheath 300 extends to the distal end through the catheter 200 .

[0144] The bending adjustment assembly 110 includes a second support body 111, which is also roughly cylindrical and fixed relative to the first support body 121. The second support body 111 itself can adopt an integrated or radially interlocked split structure. The second support body 111 and the first support body 121 are coaxially arranged and adopt a split fixed docking method.

[0145] The bending adjustment assembly 110 also includes a second driving member 112, which is rotatably installed relative to the second support body 111. The second support body 111 is partially provided with an operating port 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 operating port 116 as a force-applying portion 117. The second driving member 112 is a cylindrical structure as a whole and has an internal thread. A second connecting member 113 is slidably installed inside the second driving member 112. In order to limit the movement of the second connecting member 113, a guide bar 114 is provided on the inner wall of the second support body 111. A portion of the second connecting member 113 in the axial direction extends out of the second support body 111 and the outer wall of this portion is provided with a guide groove 115 that cooperates with the guide bar 114, so that the second connecting member 113 can only slide axially relative to the second support body 111.

[0146] In one embodiment of the present application, a sheath-core assembly for delivering interventional instruments is provided, including a core tube, a locking member fixed at the distal end of the core tube for connecting the interventional instrument, and the sheath-core assembly also includes a bend adjustment tube sleeved on the outer circumference of the core tube. The distal ends of the bend adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of the two can slide relative to each other.

[0147] The sheath-core assembly 400 includes an adjustment tube 410 and a core tube 425 that are nested inside and outside. The adjustment tube 410 is wrapped around the outside of the core tube 425. The distal ends of the two are fixedly connected to each other, and the proximal ends can slide relative to each other. The proximal end of the adjustment tube 410 is fixed to the second connecting member 113, and the proximal end of the core tube 425 extends out of the second connecting member 113 and is fixed to the tail end of the second support body 111, that is, the proximal side. In order to facilitate docking with external pipes, a pipe connector is installed at the proximal end of the core tube 425, such as a Luer connector 118.

[0148] To release or retrieve the interventional instrument, the first driver 122 is rotated to cause the first connector 123 to move axially, thereby driving the sheath tube 300 to move relative to the sheath-core assembly 400. To adjust the bend, the second driver 112 is rotated to cause the second connector 113 to move axially, thereby driving the proximal end of the bend adjustment 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 causes the distal ends of both to deflect and bend radially.

[0149] See also Figures 5a to 11 The sheath-core assembly 400 includes a bend adjustment tube 410 and a core tube assembly 420, wherein the core tube assembly 420 includes a core tube 425, and a locking member 422 is installed at the distal end of the core tube 425 for connecting the interventional instrument. The bend adjustment tube 410 is sleeved on the outer circumference of the core tube 425, and the distal ends of the bend adjustment tube 410 and the core tube 425 are fixedly connected to each other, and the proximal ends of the two can slide relative to each other.

[0150] The distal end of the bend adjustment tube 410 extends to the proximal end of the adjacent locking piece 422. The bend adjustment tube 410 can be directly fixed to the core tube 425, or directly fixed to the proximal locking piece 422, or both fixing methods can be used. Both the bend adjustment tube 410 and the core tube 425 can be made of metal materials such as sea wave tubes and fixed by welding, bonding or fasteners.

[0151] The distal end of the core tube 425 further extends beyond the locking element 422 and is secured with a guide head 421. The distal end of the guide head 421 has a converging rounded structure to facilitate passage through the body. The area between the guide head 421 and the locking element 422 serves as the loading position for the interventional instrument. The compressed interventional instrument is positioned in this position and engages with the locking element 422 for limiting movement.

[0152] In one embodiment, an inner core 424 is provided inside the core tube 425, and a locking piece 422 is extended from the distal end of the inner core 424 and a guide head 421 is fixed thereto. 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 piece serves as the loading position for the interventional instrument. The interventional instrument in a compressed state is in this position and is limited by the locking piece 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, and thus the radial space of the loading position is expanded.

[0153] See also Figure 5a and Figure 5b In some embodiments, the lock is controlled by wire. The proximal end of the interventional instrument 500 is provided with a connecting ear 501. The connecting ear 501 generally has a hanging hole or a hook for threading the pull wire 4223. The lock 422 is provided with a locking hole 4221. The distal end of the locking rod 4224 cooperates with the locking hole 4221, and the proximal end can extend to the operating handle.

[0154] When loaded, the pull cord 4223 passes through the connecting ear 501 and onto the locking rod 4224. Since the distal end of the locking rod 4224 is inserted into the locking hole 4221, the pull cord 4223 can prevent the connecting ear 501 from being released from the locking member 422. To release the connecting ear 501, the locking rod 4224 is pulled proximally and out of the locking hole 4221, releasing the pull cord 4223 and allowing the connecting ear 501 to be released from the locking member 422.

[0155] There are multiple connecting ears 501, and multiple pull wires 4223 can be configured. Each pull wire 4223 extends to the distal end through a distribution plate 4222. In order to regularize the wire harness, a wire sleeve 4225 can be installed on the outer periphery of the core tube 425 to form an extension channel for the pull wire 4223.

[0156] The matching locking rod 4224 and locking hole 4221 serve as a set of locking mechanisms. Multiple sets of locking mechanisms can be configured as needed and arranged in sequence along the circumference of the locking member 422.

[0157] See also Figure 5c In some embodiments, the locking element 422 is provided with one or more retaining grooves on its outer periphery. The interventional instrument includes a connecting lug that fits into the retaining grooves. The retaining grooves serve to limit the axial position of the interventional instrument, allowing it to be released only after radial expansion. To prevent the connecting lug from accidentally dislodging or suddenly tilting outward during release, potentially injuring tissue, a pressure strip 423 is secured to the locking element 422, cooperating with each retaining groove. After loading, the pressure strip 423 is constrained by the sheath, confining the connecting lug within the retaining groove, further enhancing safety. During release, the flexible pressure strip 423 flips outward, allowing the connecting lug to escape from the locking element 422.

[0158] The inner core 424 and the core tube 425 are both tubular structures. The core tube 425 and the inner core 424 do not require axial relative movement, so they are nested and welded together, with one or more weld fixation points being provided. If necessary, bushings can be added to the welded areas to fill radial gaps between the inner core 424 and the core tube 425, respectively, and the bushings can be welded to the inner core 424 and the core tube 425, respectively. The bushings can be made of the same material as the core tube 425.

[0159] One end of the core tube 425 is directly or indirectly fixed to the proximal side of the locking member 422, and the other end extends toward the operating handle.

[0160] In one embodiment, to facilitate bending, the core tube 425 includes a compliant segment 4251 adjacent to the locking element 422, and a third extension segment 4252 extending proximally from the compliant segment 4251. The compliant segment has a lower stiffness than the third extension segment, i.e., it has better flexibility and is easier to bend.

[0161] In one embodiment, the compliant section 4251 is made of a hypotube or a spring tube (ie, a tube wall interlayer with spirally extending reinforcing ribs), and has a length ranging from 120 mm to 180 mm, for example, 150 mm.

[0162] The third extension section 4252 is made of a hypotube or a steel cable tube (made of braided or twisted metal wires); the steel cable tube can be wrapped with a PTFE film to play a lubricating role.

[0163] In other embodiments, the core tube 425 is a whole hypotube. The hypotube can ensure axial support and radial bending. In order to control the bending direction of the compliant section 4251, the compliant section 4251 can have an axially extending reinforcing rib, which is obtained by cutting the corresponding part of the hypotube (the uncut area or the area with relatively sparse cuts becomes the reinforcing rib). The reinforcing rib can extend to the nearest end of the core tube 425. However, since there is no obvious bending adjustment requirement when the core tube 425 is near the proximal end, the reinforcing rib can also extend to the middle of the core tube 425 or slightly near the proximal end.

[0164] See also Figure 7 , Figure 8 When the conforming section 4251 is cut, the cutting slit width (i.e., the laser spot diameter) is 0.1 to 1 mm, and the slit spacing (i.e., the uncut portion between adjacent cutting slits) is 0.1 to 1 mm; an uncut portion extends axially to form a reinforcing rib 4253.

[0165] In some embodiments, the core tube is the object to be bent, and the compliant segment is configured so that the closer it is to the distal end, the smaller the ultimate curvature radius after the bending. This allows the distal end of the core tube to better adapt to complex paths. Specifically, with respect to the compliant segment, at least one of the following methods may be employed, for example:

[0166] The slit width in the compliance section changes gradually, and the closer to the distal end, the larger the slit width.

[0167] In the compliance section, the gap spacing changes gradually, and the closer to the distal end, the smaller the gap spacing.

[0168] In the compliant section, the stiffness (degree of bendability) changes gradually, and the stiffness decreases as it approaches the distal end.

[0169] See also Figures 9 to 11 The bending adjustment tube 410 is sleeved on the outside of the core tube 425. The bending adjustment tube 410 includes a pulling section and a second extension section 413 from the distal end to the proximal end, wherein the pulling section is an integrated structure and adopts a hypotube.

[0170] The distal end of the pulling section extends adjacent to the proximal end of the locking member 422 and is fixed to the core tube 425. In order to prevent the pulling section from being reversed during processing, different markings such as punching can be used at both ends of the pulling section to identify the assembly orientation of the distal and proximal ends.

[0171] The pulling section includes a first pulling section 411 , a transition section 414 and a second pulling section 412 in sequence from the distal end to the proximal end.

[0172] In this application, the bending adjustment tube 410 is located outside the core tube 425, that is, the active element that applies force during bending is outside, and the passive element that is pulled is inside. This setting allows a larger bending angle to be obtained relative to the active element being inside and the passive element being outside.

[0173] The first pulling section 411 is formed with a reinforcing rib 4111 by cutting, and the circumferential position of the reinforcing rib 4111 is 180 degrees different from the reinforcing rib 4253 of the compliant section 4251 .

[0174] The second pulling section 412 also adopts a cutting method. When the first pulling section 411 and the second pulling section 412 are cut, the cutting seam width is: 0.03~0.5mm, and the seam spacing is: 0.2mm~0.85mm; among them, the first pulling section 411 is located at the expected bending position and should be relatively softer and easier to bend. The second pulling section 412 is relatively hard, but in order to ensure a certain degree of softness, it can bend in the transportation package and can bend according to the blood vessels after entering the human body during surgery. Therefore, the cutting method is adopted. During actual operation, the seam width and seam spacing can be adjusted accordingly according to the softness and hardness requirements of different sections.

[0175] The second pulling section 412 has cutting-formed reinforcing ribs 4121 and 4122 , which are radially opposite to each other, i.e., their circumferential positions differ by 180 degrees, and both differ by 90 degrees from the circumferential positions of the reinforcing ribs 4111 of the first pulling section 411 .

[0176] The transition section 414 is not cut. The transition section 414 connects the first pulling section 411 and the second pulling section 412 and also shares the pulling stress at different circumferential positions.

[0177] The second extension section 413 has no special bending requirements and is mainly responsible for transmitting tension. For example, it uses a hypotube without additional cutting, extends to the proximal end and is connected to the operating handle.

[0178] During the bending process, the first pulling section 411 and the compliant section 4251 primarily bend to a greater degree. Therefore, when cutting the hypotube, a bending angle of >270° is generally required. The single reinforcing rib structure provided on each section ensures that the bending section does not stretch when subjected to force. The first pulling section 411 and the compliant section 4251, when superimposed internally and externally, provide moderate flexibility, facilitating bending and ensuring force transmission. Overall, the bending tube 410 is 5mm to 10mm longer than the core tube 425 to accommodate 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.

[0179] See also Figures 12 and 13To accommodate bending adjustments or changes in distal orientation during passage through the body, the outermost sheath 300 has varying degrees of softness and hardness at different axial locations. From distal to proximal, the sheath 300 comprises a loading section 310, a bending section 320, and a first extension section 330. During use, the sheath primarily bends proximally to the loading area, adjacent to the interventional instrument 500, where the bending section 320 is located.

[0180] See also Figure 14 to Figure 15d In one embodiment, the nested relationship of the sheath tube 300, the core tube assembly 420 and the bending tube 410, and the release process of the interventional instrument are shown. Figure 15d The figure also illustrates the approximate axial position relationship of each section in the sheath tube 300, the core tube assembly 420 and the bending tube 410. As for each section, the sheath tube 300 adopts a multi-layer composite structure, that is, for a certain section, a multi-layer structure is adopted and different components are included during processing. The structure and process of the sheath tube 300 are also the improvements of this application.

[0181] See also Figures 16 to 17d In one embodiment, the nested relationship between the sheath tube 300 and the core tube assembly 420 and the release process of the interventional instrument are shown. Figure 15d The figure also illustrates the approximate axial positional relationship of each section in the sheath tube 300 and the core tube assembly 420. For each section, the sheath tube 300 adopts a multi-layer composite structure, that is, for a certain section, a multi-layer structure is adopted and different components are included during processing. The structure and process of the sheath tube 300 are also one of the improvements of this application. In this embodiment, the core tube assembly 420 includes a core tube 425, on which a locking piece 422 is fixed. The distal end of the core tube 425 further extends out of the locking piece 422 and a guide head 421 is fixed at the farthest end. The distal end of the guide head 421 has a round head structure with a convergent shape to facilitate guiding and advancing in the body. The position between the guide head 421 and the locking piece 422 serves as the loading position of the interventional instrument. The interventional instrument in a compressed state is in this position and is limited by the locking piece 422.

[0182] In one embodiment, an inner core 424 is provided inside the core tube 425, and the distal end of the inner core 424 extends out of the locking piece 422 and is fixed with a guide head 421. The distal end of the core tube 425 only extends to the locking piece 422, and 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, so that the radial space of the loading position can be expanded.

[0183] In one embodiment of the present application, a sheath for delivering an interventional device is provided. The distal end of the sheath is a loading section 310 for accommodating the interventional device. The loading section 310 has a multi-layer structure, and includes, from the inside to the outside, an inner liner 375, a metal tube, and an outer membrane 380. The metal tube includes, from the proximal end to the distal end, a main body tube 350 and a head end tube 340 that are connected to each other.

[0184] The head end tube 340 includes a main body section 346, a plurality of expansion pieces 344 located at the distal end of the main body section and spaced circumferentially, a first connector 343 located at the proximal end of the main body section, and a second connector 351 located at the distal end of the main body tube 350. The first connector 343 and the second connector 351 interlock with each other and have complementary shapes. In one embodiment of the present application, a sheath tube for delivering interventional instruments is provided. The sheath tube is axially divided from the distal end to the proximal end into a loading section 310, a bendable section 320, and a first extension section 330. The loading section 310 is used to accommodate the interventional instrument 500. The sheath tube adopts a multi-layer structure, including: an inner sheath tube 370, which is axially distributed in the bendable section and the first extension section;

[0185] The inner lining tube 375 is connected to the distal end of the inner sheath tube 370 and is distributed in the loading section in the axial direction;

[0186] A metal tube is wrapped around the distal end of the inner sheath tube and the outer periphery of the inner liner tube, and the metal tubes are distributed in the bending section and the loading section in the axial direction;

[0187] The outer membrane 380 is wrapped around the outer circumference of the metal tube and is distributed in the bending section and the loading section in the axial direction.

[0188] Since the loading section 310 needs to wrap the interventional instrument, the proximal portion of the loading section 310 (ie, the bending section 320 and the first extension section 330 ) has a larger diameter than that of the sheath.

[0189] Figure 18 The diagram shows some visible parts of the sheath tube 300. The distal portion of the sheath tube 300 generally has at least a three-layer structure, wherein the inner and outer layers are both made of polymer materials, and the middle layer is a metal tube. The middle layer adopts a three-section docking structure, which includes a head end tube 340, a main body tube 350 and an extension tube 360 ​​that are docked in sequence from the distal end to the proximal end. In the axial direction, the head end tube and the main body tube are both distributed in the loading section, and the extension tube is distributed in the bending section.

[0190] The bendable section can be bent to change the direction of the distal end of the sheath during delivery, while the first extension section mainly provides sufficient axial pushing force and pulling force and has sufficient length to connect the operating handle.

[0191] The tip tube 340 is cut from a nickel-titanium alloy tube, and the main tube 350 and the extension tube 360 ​​are cut from stainless steel tubes. The tip tube 340 and the main tube 350 have a larger diameter than the extension tube 360 ​​because they are used to wrap the interventional instrument. Figure 18 In accordance with the axial positional relationship, the connecting portion between the main tube 350 and the extension tube 360 ​​is also expanded and reduced in diameter accordingly.

[0192] See also Figure 19a In one embodiment, the distal end of the head tube 340 is circumferentially defined with a plurality of spaced openings 341. Between adjacent spaced openings is an expansion piece 344, each expansion piece 344 having a hollowed-out area 345. In a preferred embodiment, the expansion pieces 344 are evenly spaced circumferentially, with a number of 3 to 6, for example, 5.

[0193] Overall, the tip tube 340 preferably has a one-piece structure. The main body section 346 is hollowed out to form a developing area 342 for mounting a developing point. The first connector 343 is T-shaped for docking with the main body tube 350 and axially limiting the position. Both the main body section 346 and the first connector 343 are provided with through-holes 347 to facilitate fusion of the polymer materials used in the inner and outer layers of the sheath tube.

[0194] The spacing 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 everted, adapting to the gradual deformation of the interventional instrument during release and preventing the interventional instrument from suddenly bursting out at the end of release. In addition, when retrieval is required, each expansion piece 344 radially everts to form a flared mouth, facilitating the gradual radial compression and storage of the interventional instrument within the sheath tube 300. To achieve better elasticity, the tip tube 340 can be made of nickel-titanium alloy, and each expansion piece can have a surrounding state extending axially along the sheath tube and an everted state away from each other.

[0195] The hollow area 345 of the expansion piece 344 facilitates deformation of the expansion piece and reduces eversion resistance. In one embodiment, the hollow area 345 is a strip hole, which extends axially along the head end tube 340. On the same expansion piece, there are one, two or more strip holes.

[0196] In a preferred embodiment, the strip holes extend in equal widths and have arc-shaped inner edges at both ends of the length direction, thereby preventing cracking caused by excessive stress concentration during deformation.

[0197] In one embodiment, each expansion piece 344 has a narrowed portion 348 at the proximal end, and the spacer opening has a corresponding widened portion at the proximal end, corresponding to the narrowed portion 348 .

[0198] In order to disperse stress, the inner edge of the widened part adopts a smooth curve, such as the teardrop-shaped large head part.

[0199] In one embodiment, the spacing opening itself generally extends with a uniform width except for a chamfered portion at the distal end to accommodate the expansion piece and a widened portion at the proximal end.

[0200] The width of the equally-width extended portion of the interval openings is substantially the same as the width of the strip-shaped hole. For example, the width of the strip-shaped hole is taken as the reference width, and the width of the equally-width extended portion of the interval openings is ±20% of the reference width.

[0201] In order to facilitate outward rotation of each expansion piece 344 at the narrowed portion 348 and reduce deformation resistance proximal to the narrowed portion, in one embodiment, the proximal side 349 of the strip-shaped hole extends beyond the narrowed portion of the expansion piece. In a preferred embodiment, the proximal side 349 of the strip-shaped hole extends beyond the narrowed portion of the expansion piece by 1 to 5 mm, for example, 1.5 to 3 mm.

[0202] To avoid potential safety hazards, in one embodiment, the distal end of the expansion piece has a smooth outer edge, for example, in the form of a chamfered corner, or in the form of an arc that bulges toward the distal end.

[0203] See also Figure 19b In one embodiment, each expansion piece 344 has a hollow region 345. Hollow regions 345 are multiple through-holes spaced axially along the sheath tube. The total area of ​​the through-holes on each expansion piece is less than 50% of the expansion piece's total area. As can be seen in the figure, the through-holes on the same expansion piece increase in area as they approach the distal end. The through-holes are circular or elliptical in shape, and the number of through-holes on any expansion piece ranges from 2 to 5.

[0204] and Figure 19a Similar to the corresponding embodiment, the main body section 346 of the head tube is hollowed out to form a developing area 342 for mounting a developing point. The first connector 343 is T-shaped for docking with the main body tube and axial positioning. Through holes 347 are distributed on both the main body section 346 and the first connector 343, allowing for better fusion of the polymer materials of the inner and outer layers of the sheath tube. Spacer openings 341 are located between adjacent expansion pieces 344. These spacer openings 341 are strip-shaped notches that are open at the distal end and closed at the proximal end. The expansion pieces 344 narrow toward the distal end, with curved edges at the distal end for enhanced safety.

[0205] To prevent the metal material of the middle layer from scratching the blood vessel wall, the outermost layer at least wraps the head end 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 material part is a multi-segment structure, the outer membrane 380 also adopts a multi-segment splicing structure during processing and then melts into one.

[0206] For example, along the axial direction of the sheath, the outer membrane 380 includes multiple sections, each section is made of a different material, or at least two sections are made of the same material.

[0207] In one embodiment, the outer coating strength corresponding to the main tube 350 is greater than the outer coating strength corresponding to the distal end of the head end tube 340 .

[0208] The inner layer includes an inner sheath tube 370 and an inner lining tube 375. One side of the inner sheath tube 370 extends proximally, and the other side extends to the connection position of the main tube 350 and the extension tube 360. The inner sheath tube 370 extends further distally from the connection position of the main tube 350 and the extension tube 360 ​​through the inner lining tube 375 until it reaches the distal side of the head end tube 340. The inner lining tube 375 can be made of PTFE material.

[0209] The axial position of the distal end portion of the extension tube 360 ​​corresponds to the compliant section 4251 and the first pulling section 411 , and the extension tube 360 ​​may also be cut to form a reinforcing rib.

[0210] See also Figures 20 to 24 The inner sheath 370 itself adopts a multi-layer structure, which includes, from the inside to the outside, a PTFE inner layer 3701, a braided layer 3702, a braided layer 3704, and an outer layer 3705, wherein two reinforcing ribs 3704 extending axially are fixedly wrapped between the braided layer 3702 and the braided layer 3704.

[0211] One of the two reinforcing ribs 3704 is located at the same circumferential position as the reinforcing rib 4253 , and the other is 180 degrees away from the circumferential position of the reinforcing rib 4253 .

[0212] The braided layer 3702 and the braided layer 3704 are not required to have a distinct layered structure and can be woven into one body and clamp the reinforcing ribs. The outer layer 3705 can be made of Pebax material.

[0213] A reinforcing rib 4253 is provided in the compliant section 4251 , and a reinforcing rib 4111 is provided in the first pulling section 411 . The circumferential positions of the reinforcing rib 4253 and the reinforcing rib 4111 are staggered by 180 degrees.

[0214] The sheath in the cross-sectional view only illustrates the extension tube 360 ​​portion. The extension tube 360 ​​may be provided with a reinforcing rib 3601. The reinforcing rib 3601 and the reinforcing rib 4253 are located on the same side in the radial direction, i.e., at the same circumferential position.

[0215] Or in other embodiments, two reinforcing ribs are provided in the extension tube 360, namely, the reinforcing rib 3601 and the reinforcing rib 3602, wherein the reinforcing rib 3601 and the reinforcing rib 4253 are located on the same side in the radial direction, i.e., at the same circumferential position, and the reinforcing rib 3602 and the reinforcing rib 4111 are located on the same side in the radial direction, i.e., 180 degrees away from the circumferential position of the reinforcing rib 4253.

[0216] The inner sheath 370 exists in both the bending section 320 and the first extension section 330. Since the bending section 320 has a larger bending angle when adjusting the bend, the strength of the inner sheath 370 in the bending section 320 and the first extension section 330 is different. The inner sheath 370 in the bending section 320 is softer. For example, the outer layer 3705 of the inner sheath 370 in the bending section 320 is made of 30-59D Pebax, and the outer layer 3705 of the inner sheath 370 in the first extension section 330 is made of 60-90D Pebax. The braided layers and PTFE inner layer 3701 at different parts of the inner sheath 370 can adopt the same settings. Figures 25 to 34 In one embodiment of the present application, a method for processing a sheath tube 300 is provided, comprising:

[0217] Step S100, forming a flared portion at the distal end of the inner sheath;

[0218] The distal end 371 of the inner sheath can be heated and softened and expanded to form a flared portion 374 in combination with the inserted core rod 372 . A portion of the outer circumference of the core rod 372 can be processed into a truncated cone section 373 according to the expected shape of the flared portion 374 .

[0219] Step S200, sleeve and fix the liner pipe on the outer periphery of the flared portion;

[0220] Take an inner lining tube 375 made of PTFE material, with ears arranged at intervals along the circumference at the end of the inner lining tube 375, and the cutting area 376 is between the ears. Wrap this end in the flared part 374, then wrap it with a fixing sleeve 377 and hot-melt it to connect the inner lining tube 375 to the distal end 371 of the inner sheath tube.

[0221] The fixing sleeve 377 and the flared portion 374 are made of the same material, such as Pebax, and the cutting area 376 facilitates the fusion of the fixing sleeve 377 and the flared portion 374 to ensure the connection strength of the liner tube 375.

[0222] Step S300: placing a metal tube on the outer periphery of the inner sheath tube and the inner liner tube;

[0223] The extension tube 360, the main tube 350 and the head end tube 340 are connected in sequence, and the adjacent two are axially limited by hooks, snaps, etc., among which the head end tube 340 is made of nickel-titanium alloy tube, while the extension tube 360 ​​and the main tube 350 can be made of stainless steel tube.

[0224] The proximal side of the head end tube 340 is provided with a T-shaped first connector 343, and the distal side of the main body tube 350 is provided with a T-shaped second connector 351. The first connector 343 and the second connector 351 cooperate with each other in axial limitation in a complementary manner.

[0225] The proximal end of the main tube 350 has a closed portion 352, which connects to the extension tube 360 ​​via this closed portion 352, which can be connected using conventional hooks or snaps. The main tube 350 has hollow areas 353 and 354 on its wall, with axially extending guide ribs 355 located between them. The guide ribs 355 limit the bending direction of the sheath tube 300. Two guide ribs 355 are arranged in radially opposite directions.

[0226] The extension tube 360, the main tube 350 and the head end tube 340 are connected in sequence and then inserted into the outside of the inner sheath tube 370 and the inner lining tube 375. The position of the flared portion 374 corresponds to the axial position of the closed portion 352. The inner lining tube 375 is slightly longer than the head end tube 340. The position of the inner lining tube 375 corresponding to the spacing opening 341 is also cut accordingly to adapt to the deformation of the expansion piece.

[0227] Step S400: Use the outer covering material to cover the metal tube in sections, and heat-melt each section of the outer covering material to form an outer covering film. Specifically, it includes:

[0228] Step S410: Wrap the first connecting sleeve 381 around the joint between the main tube 350 and the head end tube 340, wrap the head end outer sleeve 382 around the outer periphery of the head end tube 340, and fix the first connecting sleeve 381 and the head end outer sleeve 382 by hot-melt.

[0229] The head end outer sleeve 382 is also slightly longer than the head end tube 340 and is roughly aligned with the inner lining tube 375. Then the first connecting sleeve 381 and the head end outer sleeve 382 are hot-melted together with the corresponding positions of the inner lining tube 375 to wrap and fix the docking parts of the main tube 350 and the head end tube 340 as well as the inside and outside of the head end tube 340.

[0230] The first lining 383 and the second lining 384 are placed on the hollow areas 353 and 354, and then hot-melted to the corresponding positions of the inner lining tube 375, so that the first lining 383 and the second lining 384 penetrate into and fill the corresponding hollow areas.

[0231] Step S420: Wrap the main body jacket 385 around the outer periphery of the main body tube 350 and fix it by hot-melt;

[0232] 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 the joint portion between the extension tube 360 ​​and the main body tube 350 .

[0233] The head end jacket 382 requires better flexibility, and the material can be TPU, etc., while the first connecting sleeve 381, the first lining 383, the second lining 384, and the main jacket 385 can use Pebax with better strength, among which the first lining 383 and the second lining 384 can be thinner than the main jacket 385. For example, the thickness of the first lining 383 and the second lining 384 is about 0.15 mm, and the thickness of the main jacket 385 can be increased to 0.35 mm.

[0234] In addition, the first connecting sleeve 381 requires greater strength, so a relatively hard material can be selected, such as a hardness of 60-72D. The main outer sleeve 385 mainly has a protective function, and the hardness can be appropriately reduced, such as 40-55D. Step S430, wrap the second connecting sleeve 386 around the proximal end of the extension tube 360 ​​and the adjacent inner sheath tube 370, and fix the second connecting sleeve 386 by hot-melt.

[0235] Step S440: Wrap the connecting sleeve 387 around the outer periphery of the extension tube 360 ​​and fix it with hot melt.

[0236] The axial position of the connecting sleeve 387 is 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.

[0237] The second connecting sleeve 386 uses Pebax with better strength, and the connecting sleeve 387 requires better flexibility because it is located in the bending position, so the material can be TPU, etc. In addition, the connecting sleeve 387 can also prevent the internal metal tube from directly contacting and scratching the blood vessels, and also plays a sealing role.

[0238] The various sections of material wrapped around the outer circumference of the extension tube 360, the main tube 350, and the head end tube 340 are finally melted together to form an outer membrane 380. Finally, the part extending beyond the distal end of the head end tube 340 is hot-melt sealed. The part corresponding to the spacing opening 341 can also be cut accordingly to adapt to the possible deformation of the spacing opening 341, or the elasticity of the material of the head end jacket 382 itself can be used to adapt.

[0239] See also Figures 35 to 40 When the bend adjustment system of the present application is used, the orientation of the distal part can be actively changed by pulling the bend adjustment tube at the operating handle, which is more adaptable to the delivery of complex paths. Taking the insertion of the 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 directed to and positioned at the aortic valve 600 by bending. Since the bend adjustment tube pulls the core tube assembly, the interventional device loaded on the core tube assembly does not change its orientation when the sheath is withdrawn to release the interventional device, which can avoid the hidden danger of misplacement during the release process.

[0240] The technical features of the above-described embodiments may be combined in any manner. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as no contradiction exists between these combinations of technical features, they 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 deemed that the drawing also discloses examples of combinations of the various embodiments involved.

[0241] The above-described embodiments merely represent several implementation methods of the present application. 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 a person skilled in the art may make various modifications and improvements without departing from the spirit of the present application, and such modifications and improvements are all within the scope of protection of the present application.

Claims

1. A sheath assembly, characterized in that: The sheath-core assembly comprises a sheath tube and a sheath-core assembly that are slidably nested. The sheath-core assembly comprises a core tube. A locking piece is installed at the distal end of the core tube for connecting an interventional instrument. The distal end of the core tube further extends beyond the locking piece and is fixed with a guide head. The sheath tube is axially composed of a loading section, a bending section, and a first extension section from the distal end to the proximal end; the loading section adopts a multi-layer structure, and comprises, from the inside to the outside, an inner liner tube, a metal tube, and an outer membrane, wherein the metal tube comprises, from the proximal end to the distal end, a main body tube and a head end tube; the head end tube comprises a main body section, and a plurality of elastic expansion pieces located at the distal end of the main body section and arranged at intervals along the circumferential direction; the main body section of the head end tube is hollowed out to form a developing area; each expansion piece has a surrounding state extending along the axial direction of the sheath tube and an everted state away from each other; The proximal end of the main body tube is provided with a closing portion, and is connected to a metal extension tube through the closing portion. The extension tube is a hypotube, and the extension tube is distributed in a suitable bending section in the axial direction; The proximal end of the inner liner is butted against an inner sheath tube, and the inner sheath tube is axially distributed in the bending section and the first extension section; the inner sheath tube has different strengths in the bending section and the first extension section, and the inner sheath tube is softer in the bending section; The core tube includes a compliant section adjacent to the locking element and a third extension section connected to the compliant section and extending proximally. The axial position of the distal end of the extension tube corresponds to the compliant section, and the compliant section has smaller rigidity than the third extension section.

2. The sheath assembly according to claim 1, wherein The outer membrane further extends proximally to wrap around the outer circumference of the extension tube.

3. The sheath assembly according to claim 2, wherein: The loading section has a larger diameter than the bending section and the first extension section; The distal part of the sheath has at least a three-layer structure. The inner and outer layers are both made of polymer materials, and the middle layer is a metal tube. The middle layer adopts a three-section docking structure. From the distal end to the proximal end, it includes the head end tube, the main body tube and the extension tube that are docked in sequence. In the axial direction, the head end tube and the main body tube are distributed in the loading section, and the extension tube is distributed in the bending section.

4. The sheath assembly according to claim 1, wherein: The compliant section adopts a hypotube, and the third extension section adopts a steel cable tube or a hypotube.

5. The sheath assembly according to claim 4, wherein: The length of the compliant section ranges from 120 to 180 mm.

6. The sheath assembly according to claim 1, wherein: Two hollow areas are distributed on the tube wall of the main tube.

7. The sheath assembly according to claim 6, wherein: Two guide ribs extending axially and arranged radially opposite to each other are distributed between the two hollow areas.

8. The sheath assembly according to claim 1, wherein: The strength of the outer membrane corresponding to the main body tube is greater than the strength of the outer membrane corresponding to the distal end of the head end tube.

9. The sheath assembly according to claim 1, wherein: The main body tube and the head end tube are cut from metal tubes of different materials.

10. The sheath assembly according to claim 1, wherein: The sheath-core assembly further comprises a bending adjustment tube sleeved on the periphery of the core tube or located inside the core tube. The distal ends of the bending adjustment tube and the core tube are fixedly connected to each other, and the proximal ends of the two can slide relative to each other.

11. The sheath assembly according to claim 10, wherein: The bending adjustment tube includes a pulling section and a second extension section from the distal end to the proximal end; the pulling section is an integrated structure and adopts a sea wave 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.

12. The sheath assembly according to claim 11, wherein: The length of the compliant section ranges from 120 mm to 180 mm.

13. The sheath assembly according to claim 1, wherein: The expansion pieces are evenly arranged along the circumferential direction, and the number thereof is 3 to 6.

14. The sheath assembly according to claim 1, wherein: Each expansion piece has a hollow area.

15. The sheath assembly according to claim 14, wherein: The hollow area is a plurality of through holes arranged at intervals along the axial direction of the sheath tube.

16. The sheath assembly according to claim 15, wherein: The total area of ​​the through holes on each expansion sheet is less than 50% of the area of ​​the expansion sheet.

17. The sheath assembly according to claim 16, wherein: On the same expansion sheet, the through hole closer to the distal end has a larger area.

18. The sheath assembly according to claim 17, wherein: The through holes are circular or elliptical, and the number of through holes on the same expansion sheet is 2 to 5.

19. The sheath assembly according to claim 15, wherein: The hollow area is a strip-shaped hole, and the strip-shaped hole extends axially along the head end tube.

20. The sheath assembly according to claim 19, wherein On the same expansion sheet, there are two strip-shaped holes, and each of the strip-shaped holes extends with the same width.

21. The sheath assembly according to claim 19, wherein Both ends of the strip-shaped hole in the length direction are arc-shaped inner edges.

22. The sheath assembly according to claim 15, wherein: There is a spacing opening between two adjacent expansion pieces. Each expansion piece has a narrowing portion at its proximal end, and the spacing opening has a widening portion corresponding to the narrowing portion at its proximal end.

23. The sheath assembly according to claim 22, wherein: The inner edge of the widened portion is a smooth curve.

24. The sheath assembly according to claim 22, wherein: The middle area of ​​the spacing opening in the length direction extends with equal width.

25. The sheath assembly according to claim 22, wherein: The hollow area is a strip-shaped hole, and the strip-shaped hole extends axially along the head end tube; the proximal end side of the strip-shaped hole passes over the narrowed portion of the expansion piece where it is located.

26. The sheath assembly according to claim 25, wherein: The width of the equal-width extension portion of the interval opening is the same as the width of the strip-shaped hole.

27. The sheath assembly according to claim 25, wherein: The proximal end of the strip hole extends 1 to 5 mm beyond the narrowed portion of the expansion piece.

28. The sheath assembly according to claim 1, wherein: The distal end of the expansion piece has a smooth outer edge.

29. The sheath assembly according to claim 4, wherein: A first reinforcing rib extending in the axial direction is provided in the compliant section; The inner sheath tube adopts a multi-layer structure, and a fourth reinforcing rib extending axially is arranged in the interlayer. There are two fourth reinforcing ribs, one of which is at the same circumferential position as the first reinforcing rib, and the other fourth reinforcing rib is 180 degrees out of circumferential position with the first reinforcing rib.

30. The sheath assembly according to claim 29, wherein The first reinforcing rib is obtained by cutting the corresponding portion of the hypotube.

31. The sheath assembly according to claim 30, wherein: The cutting slit width of the compliant section is 0.1-1 mm, and the slit spacing is 0.1-1 mm; an uncut portion extends axially to form the first reinforcing rib.

32. The sheath assembly according to claim 4, wherein: The compliant section is configured such that the closer it is to the distal end, the smaller the limit curvature radius after being bent, specifically in at least one of the following ways: a) the cutting slit width in the compliant section changes gradually, and the cutting slit width increases as it approaches the distal end; b) the gap spacing in the compliant section gradually changes, and the gap spacing becomes smaller as it approaches the distal end; c) In the compliant section, the stiffness changes gradually, and the closer to the distal end, the lower the stiffness.

33. The sheath assembly according to claim 29, wherein: The outer membrane further extends proximally and wraps around the outer circumference of the extension tube; The distal end of the fourth reinforcing rib extends to the proximal end of the extension tube or the distal end of the extension tube.

34. The sheath assembly according to claim 33, wherein: A fifth reinforcing rib extending in the axial direction is provided in the extension tube. The fifth reinforcing rib is one and is located at the same circumferential position as the first reinforcing rib.

35. The sheath assembly of claim 33, wherein: A fifth reinforcing rib extending along the axial direction is provided in the extension tube. There are two fifth reinforcing ribs, one of which is at the same circumferential position as the first reinforcing rib, and the other fifth reinforcing rib is 180 degrees out of circumferential position with the first reinforcing rib.

36. The sheath assembly according to claim 1, wherein: The proximal end of the inner liner is butted against an inner sheath tube, and the inner sheath tube is axially distributed in the bending section and the first extension section; the inner sheath tube adopts a multi-layer structure, wherein the outer layer of the bending section adopts 30-59D Pebax; The outer layer of the first extension section is made of 60-90D Pebax.

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