Sheath distal end structure for delivery of an interventional instrument and sheath

Abstract

The application discloses a sheath distal end structure for conveying an interventional instrument and a sheath. The sheath distal end structure for conveying an interventional instrument comprises a tubular body section having opposite distal and proximal sides, a plurality of elastic expansion pieces are arranged at the distal side of the body section in a circumferential interval, each expansion piece has a folding state extending axially along the body section and an eversion state away from each other, a connecting strip is arranged between two adjacent expansion pieces, two ends of the connecting strip are connected to the expansion pieces on the corresponding side respectively, and the connecting positions are adjacent to the distal ends of the expansion pieces; in the folding state of each expansion piece, the middle part of the connecting strip is folded and stored in the interval area of the two adjacent expansion pieces; and in the eversion state of each expansion piece, the middle part of the connecting strip is relatively unfolded.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a sheath distal end structure and a sheath for delivering an interventional device. BACKGROUND

[0002] An interventional device delivery system generally comprises a sheath core assembly and a sheath sleeved on the outside of the sheath core assembly, both of which constitute a sheath assembly and have a distal end that can enter the human body's vasculature and a proximal end connected to an operating handle. Based on the tortuous characteristics of the human body's vasculature and the consideration of remote operation, the direction of the distal end can be adjusted and controlled as needed to move to the target position.

[0003] In some cases, the interventional device is released in an improper position during surgery and needs to be retrieved and released again. The distal end of the existing sheath is a loading section for wrapping the interventional device, which is mostly a composite structure, that is, it has a metal skeleton, and a film is applied to the inside and / or outside of the metal skeleton to seal and improve smoothness. The sheath distal end adopts a radially expandable structure to facilitate the re-storing of the interventional device with an expanded distal end into the sheath, but the strength of the expanded structure and how to balance the reliability of the retrieval still need to be improved. SUMMARY

[0004] The present application provides a sheath distal end structure that further ensures reliability while considering strength.

[0005] The sheath distal end structure for delivering an interventional device according to the present application comprises a tubular body section, the body section has opposite distal and proximal sides, a plurality of elastic expansion pieces are arranged at the distal side of the body section in a circumferential direction, each expansion piece has a folding state extending in the axial direction of the body section and an everted state away from each other, a connecting strip is arranged between two adjacent expansion pieces, the two ends of the connecting strip are respectively connected to the expansion pieces on the corresponding side, and the connecting part is adjacent to the distal end of the expansion piece.

[0006] In the folding state of each expansion piece, the middle part of the connecting strip is folded and stored in the spacing area between the two adjacent expansion pieces.

[0007] In the everted state of each expansion piece, the middle part of the connecting strip is relatively unfolded.

[0008] The following also provides several optional modes, but not as an additional limitation to the above general scheme, just a further supplement or preferred, without technical or logical contradiction, each optional mode can be combined with the above general scheme, and can also be combined between multiple optional modes.

[0009] Optionally, the distal side edge of each expansion piece is arc-shaped, and the connecting strip extends along the tangential direction of the arc to connect to the distal side edge of the corresponding expansion piece.

[0010] Optionally, the two adjacent connecting strips butt against the distal side edge of the same expansion sheet, and the distal side edge of the butt joint part is smoothly transitioned.

[0011] Optionally, all the connecting strips continuously extend in the circumferential direction of the body section.

[0012] Optionally, in the folded state of each expansion sheet, the middle part of the connecting strip is U-shaped on the proximal side, and the bottom of the U-shaped part has two corner parts, and a protruding part is arranged on the outer side of each corner part.

[0013] Optionally, the two adjacent expansion sheets are spaced apart, and in the folded state of each expansion sheet, the connecting strip extends along an arc path from both ends thereof into the spaced-apart opening.

[0014] Optionally, in the folded state of each expansion sheet, the proximal side of the connecting strip is adjacent to the middle part of the spaced-apart opening in the axial direction of the body section.

[0015] Optionally, in the everted state of each expansion sheet, the two protruding parts corresponding to the same U-shaped part are adjacent to or abut against each other.

[0016] Optionally, in the everted state of each expansion sheet, the connecting strip is substantially V-shaped, and the top angle of the V-shaped part is greater than or equal to 120 degrees.

[0017] Optionally, the body section, the expansion sheets, and the connecting strips are of an integral structure.

[0018] Optionally, in the axial direction of the body section, the middle part of the spaced-apart opening is widened, and both ends thereof are narrowed.

[0019] Optionally, each expansion sheet has a first hollowed-out area, and the expansion sheets are arranged in a circumferential direction, and the number thereof is 3-6.

[0020] Optionally, the total area of the first hollowed-out area on the same expansion sheet is less than 50% of the area of the expansion sheet.

[0021] Optionally, the first hollowed-out area is a plurality of through holes, and the through holes on the same expansion sheet are arranged in an axial direction or a circumferential direction of the sheath.

[0022] Optionally, the side wall of the body section is arranged with a plurality of second hollowed-out areas.

[0023] Optionally, the second hollowed-out area is a plurality of through holes, and the through holes on the body section are arranged irregularly or in an array on the circumferential surface.

[0024] Optionally, the distal end structure of the sheath is cut from a pipe material having a shape memory function.

[0025] Optionally, the main body tube and the head-end tube are an integral cutting structure or a split docking structure. Optionally, the proximal end of the body section is provided with a connecting head that cooperates with other parts of the sheath tube.

[0026] The present application also provides a sheath tube for delivering an interventional instrument, a distal end of the sheath tube being a loading section for receiving the interventional instrument, the loading section adopting a multi-layer structure and comprising, from inside to outside, an inner liner tube, a metal tube and an outer covering film, wherein the metal tube comprises a main body tube and a head-end tube from the proximal end to the distal end; the head-end tube adopts the sheath tube distal end structure as described in the present application.

[0027] The present application also provides a sheath tube for delivering an interventional instrument, the sheath tube comprising, from the distal end to the proximal end in the axial direction, a loading section, a bending section and a first extension section, the sheath tube adopting a multi-layer structure and comprising:

[0028] an inner sheath tube, the inner sheath tube being distributed in the bending section and the first extension section in the axial direction;

[0029] an inner liner tube, the inner liner tube being docked at the distal end of the inner sheath tube and being distributed in the loading section in the axial direction;

[0030] a metal tube, the metal tube being wrapped around the outer periphery of the distal end of the inner sheath tube and the inner liner tube, the metal tube comprising, from the distal end to the proximal end, a head-end tube, a main body tube and an extension tube arranged in sequence, the head-end tube and the main body tube being both distributed in the loading section in the axial direction, and the extension tube being distributed in the bending section, wherein the head-end tube adopts the sheath tube distal end structure as described in the present application;

[0031] an outer covering film, the outer covering film being wrapped around the outer periphery of the metal tube and being distributed in the bending section and the loading section in the axial direction.

[0032] Optionally, the proximal end of the body section of the sheath tube distal end structure is provided with a first connecting head, and the distal end of the main body tube is provided with a second connecting head, the first connecting head and the second connecting head being mutually embedded and complementary in shape.

[0033] Optionally, the first connecting head and the second connecting head are both T-shaped.

[0034] Optionally, the metal tube has a through hole, and the inner liner tube and the outer covering film are heat-fused and / or bonded to each other through the through hole.

[0035] The sheath tube distal end structure of the present application adopts a radial expandable structure, which can ensure the strength and guide the receiving of the interventional instrument through the multi-lobed metal sheet, i.e. the expansion sheet, and can further ensure the reliability through the connecting strip to avoid the mutual jamming of the structural gap between the expansion sheet and the interventional instrument. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figures la-lb Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0037] Figures lc-ld Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0038] Figure 2a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0039] Figure 2b Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 2a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0040] Figure 3a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 2a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0041] Figure 3b Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 3a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0042] Figure 4 Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 2a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0043] Figure 5a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0044] Figure 5b Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 5a Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0045] Figure 5c Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0046] Figure 6 Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0047] Figure 7 Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0048] Figure 8 Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 7

[0049] Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 9

[0050] Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state; Figure 10 Figure 9 Structure schematic diagram of the sheath distal end structure in an embodiment of the present application, different perspective views of each expansion piece in the folded state;

[0051] ​Figure 11 Fig. 1 is a perspective view of a delivery system according to an embodiment of the present application; Figure 9 Fig. 2 is an exploded view of a curved tube according to an embodiment of the present application;

[0052] Figure 12 Fig. 3 is a perspective view of a sheath tube according to an embodiment of the present application;

[0053] Figure 13 Fig. 4 is a perspective view of a sheath tube according to an embodiment of the present application; Figure 5c Figure 6 Figure 12 Fig. 5 is a perspective view of a sheath tube according to an embodiment of the present application;

[0054] Figure 14 Fig. 6 is a cross-sectional view of a sheath tube assembly according to an embodiment of the present application;

[0055] Figure 15a Fig. 7 is a perspective view of a sheath tube according to an embodiment of the present application; Figure 14

[0056] Fig. 8 is a perspective view of a sheath tube according to an embodiment of the present application; Figure 15b Figure 15a Fig. 9 is a perspective view of a sheath tube according to an embodiment of the present application;

[0057] Figure 15c Figure 15a Fig. 10 is a perspective view of a sheath tube according to an embodiment of the present application;

[0058] Figure 15d Fig. 11 is a perspective view of a sheath tube according to an embodiment of the present application;

[0059] Figure 16 Fig. 12 is a cross-sectional view of a sheath tube and inner core assembly according to an embodiment of the present application;

[0060] Figure 17a Fig. 13 is a perspective view of a sheath tube according to an embodiment of the present application; Figure 16

[0061] Fig. 14 is a perspective view of a sheath tube according to an embodiment of the present application; Figure 17b Figure 17a Fig. 15 is a perspective view of a sheath tube according to an embodiment of the present application;

[0062] Figure 17c Figure 17a Fig. 16 is a perspective view of a sheath tube according to an embodiment of the present application;

[0063] Figure 18 Fig. 17 is a perspective view of a sheath tube according to an embodiment of the present application;

[0064] Figure 19 Fig. 18 is an exploded view of a sheath tube according to an embodiment of the present application;

[0065] Figure 20 Fig. 19 is a perspective view of a delivery system according to an embodiment of the present application;

[0066] Figure 21 Fig. 20 is a perspective view of a delivery system according to an embodiment of the present application;​​​​​​Figure 20 Cross-sectional view of the inner sheath at the CC site;

[0067] Figure 22 for Figure 21 A magnified view of part A in the middle;

[0068] Figure 23 for Figure 20 Cross-sectional view of the middle BB area;

[0069] Figure 24 for Figure 20 A cross-sectional view of another embodiment at the BB portion;

[0070] Figure 25 This is a schematic diagram of the distal end changes when the interventional device delivery system of this application is adjusted.

[0071] The reference numerals in the figures are described as follows:

[0072] 100. Operating handle;

[0073] 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;

[0074] 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;

[0075] 130, front handle; 131, slide key; 132, slide slot;

[0076] 200, catheter;

[0077] 300, sheath; 310, loading section; 320, bending section; 330, first extension section; 340, head end tube; 341, spacer opening; 342, connecting strip; 342a, connecting strip; 342b, connecting strip; 343, first connector; 344, expansion piece; 345, hollow area; 346, main body section; 347, middle section; 348, distal side edge; 349, protrusion; 350, main body tube; 351, second connector; 360, extension tube; 3601, reinforcing rib; 3602, reinforcing rib; 370, inner sheath; 3701, PTFE inner layer; 3702, braided layer; 3703, reinforcing rib; 3704, braided layer; 3705, outer layer; 375, inner liner; 380, outer membrane;

[0078] 400, sheath core assembly;

[0079] 410, bent pipe; 411, first pulling section; 4111, reinforcing rib; 412, second pulling section; 4121, reinforcing rib; 4122, reinforcing rib; 413, second extending section; 414, transition section;

[0080] 420, core tube assembly; 421, guide head; 422, lock; 4221, lock hole; 4222, wire distribution disc; 4223, pull wire; 4224, lock rod; 4225, wire sleeve; 423, pressing strip; 424, inner core; 425, core tube; 4251, compliant section; 4252, third extending section; 4253, reinforcing rib;

[0081] 500, interventional instrument; 501, connecting ear. DETAILED DESCRIPTION

[0082] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0083] It should be noted that when an assembly is referred to as being "connected" to another assembly, it can be directly connected to the other assembly or there can be an intermediate assembly. When an assembly is referred to as being "disposed on" another assembly, it can be directly disposed on the other assembly or there can be an intermediate assembly.

[0084] 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 in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the terms "and / or" includes any and all combinations of one or more of the associated listed items.

[0085] In an interventional procedure, if the release position of an interventional instrument is improper, it is often necessary to be recovered and released again. The distal end of the existing sheath adopts a plurality of radially expandable expansion pieces, which facilitates the re-storing of the interventional instrument whose guide distal end has been expanded into the sheath. In actual operation, some interventional instruments may fail to be recovered. After analysis, these interventional instruments often have relatively large structural gaps (for example, the grid is relatively sparse). When recovered, the expansion pieces may occasionally be inserted into the structural gaps of the interventional instrument, blocking the movement of the interventional instrument and failing to be retracted into the sheath.

[0086] An embodiment of the present application provides a sheath distal end structure, which is a distal end part of a sheath, i.e. a head-end tube 340, only a metal framework part, and is connected with other parts (proximal end side part) of the sheath in use, and generally needs to be covered with a film to ensure necessary protection and sealing.

[0087] The sheath distal end structure of the embodiment comprises a tubular body segment 346 having opposite distal end side and proximal end side, a plurality of elastic expansion pieces 344 are arranged at the distal end side of the body segment 346 in a circumferential direction, each expansion piece 344 has a folding state extending in an axial direction of the body segment 346 and an everted state away from each other, and a connecting strip 342 is arranged between two adjacent expansion pieces 344, two ends of the connecting strip 342 are connected to the expansion pieces 344 on the corresponding side respectively, and the connecting position is adjacent to the distal end of the expansion piece 344.

[0088] Referring to Figure la , Figure lb , in the folding state of each expansion piece 344, the middle part 347 of the connecting strip 342 is folded and stored in the spacing area between the two adjacent expansion pieces;

[0089] Referring to Figure lc , Figure ld , in the everted state of each expansion piece 344, the middle part 347 of the connecting strip 342 is unfolded relatively (relative to the folding state).

[0090] The distal end side of each expansion piece 344 in the prior art is isolated, so it is possible to be embedded in the structural gap of the interventional instrument 500, which hinders the recovery. Furthermore, the radial contraction force of each expansion piece 344 in the everted state is insufficient, and the effect of guiding the interventional instrument 500 is not good.

[0091] The sheath distal end structure, i.e. the head-end tube 340, of the embodiment is further improved, and the connecting strip 342 is added between two adjacent expansion pieces 344. The connecting strip 342 itself can be a single strip, a double strip or have a mesh or hollow structure, etc. Overall, it is connected between two adjacent expansion pieces 344. Especially in the everted state, the connecting strip 342 provides an additional pulling force between the two expansion pieces 344, strengthens the radial restraint force of all expansion pieces 344, and improves the guiding and recovery effect of the interventional instrument 500. The interventional instrument 500 is retracted in the sheath along the X3 direction while being bundled. More importantly, the connecting position of the connecting strip 342 and the expansion piece 344 is adjacent to the distal end of the expansion piece 344, which eliminates the isolated expansion piece 344 end or spike structure, and avoids being poked into the structural gap of the interventional instrument 500.

[0092] The end of the connecting strip 342 and the expansion sheet 344 of the corresponding side, the connecting position adjacent to the distal end of the expansion sheet 344 can be understood as close to or just at the distal end of the expansion sheet 344, especially in the eversion state, the distal end of the expansion sheet 344 can avoid forming an isolated convex position, reducing the risk of interference with the interventional instrument.

[0093] The shape of the middle part 347 is not strictly limited, mainly to connect and pull the two connected expansion sheets 344 in the eversion state, and the middle part 347 needs to be folded and stored in the surrounding state, so a foldable structure is adopted. The folding process can be driven by the elasticity of the expansion sheet 344, or the middle part 347 itself can be made of a predetermined elastic material to assist the folding. After folding, it is stored between the adjacent two expansion sheets and extends correspondingly to the proximal end.

[0094] The connection mode of the expansion sheet 344 and the connecting strip 342 affects the stress distribution and the folding effect of the connecting strip 342. In an embodiment, the distal side edge 348 of each expansion sheet 344 is arc-shaped, and the connecting strip extends along the tangent of the arc to the distal side edge of the corresponding expansion sheet. Figure lc The two adjacent connecting strips are connecting strip 342a and connecting strip 342b, respectively, wherein the connecting strip 342a extends along the X1 direction towards the distal side edge 348 of the expansion sheet 344, and the connecting strip 342b extends along the X2 direction towards the distal side edge 348 of the expansion sheet 344, and the connecting strip 342a and the connecting strip 342b are integrated with each other.

[0095] The arc-shaped distal side edge 348 only expresses the general trend or overall shape characteristics, and is not strictly limited. Each connecting strip extends along the tangent and converges, which provides better radial folding force and more reasonable stress distribution.

[0096] In another embodiment, the two adjacent connecting strips are connected to the distal side edge of the same expansion sheet, and the distal side edge of the connecting position is smoothly transitioned. The smooth outer edge can avoid safety hazards, such as the connecting strip 342a and the connecting strip 342b being connected to the distal side edge 348 of the same expansion sheet 344. After the connection, the connecting position is relatively smooth, avoiding the interference of the sharp or protruding part with the interventional instrument 500.

[0097] Further, all the connecting strips continuously extend in the circumferential direction of the body segment 346. As can be seen from the figure, since the adjacent connecting strips are smoothly connected, all the connecting strips are connected into a ring, although the middle part 347 will have slight ups and downs, which does not affect the overall trend,

[0098] In an embodiment, in the folded state, the middle part 347 of the connecting strip 342 is U-shaped at the proximal end side, the bottom of the U-shape has two corner parts, and a protrusion 349 is arranged at the outer side of each corner part. The protrusion 349 can structurally reinforce the corner part and avoid fatigue damage caused by repeated bending.

[0099] In an embodiment, in the everted state, the two protrusions corresponding to the same U-shape are adjacent to or abut against each other. The two protrusions adjacent to or abutting against each other can limit the unfolding angle of the connecting strip 342, so as not to be reversely folded in an extreme or abnormal case.

[0100] In an embodiment, the two adjacent expansion pieces are spaced apart by an opening 341, and in the folded state, the connecting strip 342 extends along an arc-shaped path from the two end parts thereof to the opening 341. That is, the connecting strip 342 is arc-shaped at the distal end side edge 348 adjacent to the expansion piece 344, which better conforms to the shape characteristics of the expansion piece 344 and extends close to the edge of the expansion piece 344, thereby occupying less space. The arc-shaped structure also does not excessively concentrate stress during unfolding, thereby reducing the security risk of fatigue fracture.

[0101] In the folded state, the proximal end side of the connecting strip 342 is adjacent to the middle part of the opening 341 in the axial direction of the body segment 346. In the folded state, the opening 341 is a generally strip-shaped gap, the distal end of which is closed by the connecting strip 342, and the proximal end of which is closed by the body segment 346. The head-end tube 340 can be made of a flexible metal material such as nickel-titanium alloy, that is, the body segment, the expansion piece, and the connecting strip are preferably integrated, so that the expansion piece 344 can be radially everted, can adapt to the gradual deformation of the interventional instrument during release of the interventional instrument, and can prevent the interventional instrument from suddenly collapsing at the end of release. In addition, when it is necessary to be recovered, the expansion piece 344 is radially everted to form a trumpet mouth, so as to facilitate guiding the interventional instrument to be gradually compressed and accommodated in the sheath tube 300.

[0102] The connecting strip 342 determines the extension position of the proximal end side after folding. In the axial direction of the body segment 346, the length relationship between the opening 341 and the connecting strip 342 also affects the limit everted angle of the expansion piece 344. Therefore, a suitable matching relationship is helpful to control the spatial posture of the expansion piece 344 during release or recovery, so as to ensure the shape control of the interventional instrument.

[0103] In the everted state, the connecting strip 342 is generally V-shaped, and the top angle of the V-shape is greater than or equal to 120 degrees. Of course, in combination with the foregoing, the top angle of the V-shape is in a rounded structure, and is generally U-shaped.

[0104] In an embodiment, each expansion piece has a hollow region, and the expansion pieces are arranged in a circumferential direction, and the number thereof is 3-6, for example, 5.

[0105] The hollowed-out area 345 of the expansion sheet 344 facilitates deformation of the expansion sheet and reduces the resistance to eversion. In one embodiment, the hollowed-out area 345 is a strip-shaped hole, a circular hole, an elliptical hole, or a water-drop-shaped hole. The hollowed-out areas 345 on the same expansion sheet are one or multiple and are isolated from each other. The inner edge of each hollowed-out area is smooth to avoid cracking due to excessive stress concentration during deformation. The total area of the hollowed-out areas 345 on the same expansion sheet is less than 50% of the area of the expansion sheet. The hollowed-out areas 345 are multiple through-holes, which are arranged on the same expansion sheet in an axial direction or a circumferential direction.

[0106] The body section 346 can also be formed with a developing area in a hollowed-out manner for mounting a developing point to facilitate monitoring of the position or posture of the instrument during the operation through an image device.

[0107] During subsequent processing, a film structure can be arranged on both the inner and outer sides of the body section 346 in a radial direction. In order to facilitate fusion between the inner and outer films, multiple second hollowed-out areas are arranged on the side wall of the body section. The second hollowed-out areas are multiple through-holes, which can be arranged in a random manner or in an array on the peripheral surface.

[0108] In the axial direction of the body section 346, the middle part of the body section is widened and the two ends are narrowed. The expansion sheet 344 is gradually widened at a position adjacent to the proximal end thereof to improve the connection strength and ensure necessary resilience. The distal end of the expansion sheet is provided with an arc-shaped edge to disperse stress and improve safety.

[0109] The proximal end of the body section 346 is provided with a connecting head that cooperates with other parts of the sheath. For example, the first connecting head 343 is T-shaped. Through-holes are arranged on the body section 346 and the first connecting head 343 to facilitate fusion of the high-molecular materials serving as the inner and outer layers of the sheath.

[0110] Overall, the distal end structure of the sheath is cut from a tube material having a shape memory function, such as a nickel-titanium alloy.

[0111] Referring to Figures la-4 In one embodiment of the present application, an interventional instrument delivery system is provided, which has opposite distal and proximal ends. The delivery system includes an operating handle 100 at the proximal end and a sheath assembly connected to the operating handle 100 and extending toward the distal end. The sheath assembly includes a sheath 300 and a sheath core assembly 400,

[0112] The sheath core assembly includes a core tube and a locking piece coupled to the distal end of the core tube for connecting an interventional instrument.

[0113] The sheath 300 is slidingly fitted on the outer periphery of the sheath core assembly 400. The distal end of the sheath is a loading section and is used to accommodate an interventional instrument.

[0114] Multiple elastic expansion sheets 344 are arranged on the distal end side of the loading section in a circumferential direction (which can be combined with the Figures la-ld), each expansion piece 344 has a closed state along the body segment 346 and an everted state away from each other, and a connecting strip 342 is arranged between two adjacent expansion pieces 344, and two ends of the connecting strip 342 are connected to the expansion pieces 344 on the corresponding sides respectively, and the connecting positions are adjacent to the distal ends of the expansion pieces 344;

[0115] Referring to Figure la , Figure lb , in the closed state of each expansion piece 344, the middle part 347 of the connecting strip 342 is folded and stored in the interval region between the two adjacent expansion pieces;

[0116] Referring to Figure lc , Figure ld , in the everted state of each expansion piece 344, the middle part 347 of the connecting strip 342 is unfolded relatively (relative to the closed state).

[0117] As for the sheath tube 300, the sheath tube distal end structure of each of the above embodiments can be used, and the specific structure of the sheath tube itself will be improved in the following embodiments.

[0118] The lock in the sheath core assembly can have various forms of structures, for example, a groove form is connected with the connecting lug on the support, or a convex head form protrudes radially outward, or a wire control mode is used, and a long wire or a wire ring is connected with the support. No matter which form is used, the purpose is to realize the connection with the connecting lug of the support.

[0119] In some embodiments, the sheath core assembly further comprises a bending adjusting mechanism sleeved on the outer periphery of the core tube. The bending adjusting mechanism can drive the movement of the distal end of the core tube and change the orientation to adapt to the placement position of the interventional instrument.

[0120] In some embodiments, the bending adjusting mechanism is a bending tube, and the distal ends of the bending tube and the core tube are fixedly connected with each other, and the proximal ends of the two are extended and connected to the operation handle and can slide relatively.

[0121] In some embodiments, the sheath core assembly further comprises a bending tube inside the core tube, and the distal ends of the bending tube and the core tube are fixedly connected with each other, and the proximal ends of the two can slide relatively.

[0122] No matter the internal and external relationship between the core tube and the bending tube, the proximal ends of the two need to have relative movement. Generally, in the bending process, the proximal end part of the core tube is kept unchanged, or the proximal end part of the core tube is taken as a reference, and the proximal end of the bending tube is pulled. The different internal and external relationships between the core tube and the bending tube can lead to different abutting positions of the two at the turning part. The following embodiments and the accompanying drawings mainly take the bending tube on the outer side as an example. As for the structure of the operation handle, the proximal ends of the two can be adjusted to have relative movement according to the adjustment of the internal and external relationship between the core tube and the bending tube.

[0123] In other embodiments, the interventional instrument delivery system can further comprise a catheter 200 fixed relative to the operation handle 100, which is used to establish a channel to prevent the sheath tube 300 from injuring the body tissue during reciprocating movement. The interventional instrument is loaded in the sheath core assembly 400 and enters the body together with the catheter 200 under the wrapping of the sheath tube 300, and then the sheath tube 300 can be axially moved relative to the other two to achieve the release of the interventional instrument and the recovery operation if necessary.

[0124] The bending is mainly achieved by the operation handle 100. Referring to the embodiment shown in Figures 3a-4 The operation handle 100 is used to connect the proximal ends of the three nested tubes in order from inside to outside, and drive the proximal ends of the three tubes to move relative to each other, the three tubes are the core tube, the bending tube and the sheath tube from inside to outside, and the operation handle 100 comprises a control assembly 120, a bending assembly 110 and a front handle 130;

[0125] The control assembly 120 comprises:

[0126] A first support body 121 fixed relative to the front handle 130;

[0127] A first connecting piece 123 slidingly installed on the first support body 121, and the proximal end of the sheath tube is fixed to the first connecting piece 123;

[0128] A first driving piece 122 movably installed on the first support body 121 and driving the first connecting piece 123 to slide;

[0129] The bending assembly 110 comprises:

[0130] A second support body 111 fixed relative to the first support body 121;

[0131] A second connecting piece 113 slidingly installed on the second support body 111, and the proximal end of the bending tube is fixed to the second connecting piece 113 after passing through the sheath tube;

[0132] A second driving piece 112 movably installed on the second support body 111 and driving the second connecting piece 113 to slide;

[0133] A pipe joint fixedly installed at the proximal end of the second support body 111, and the proximal end of the core tube is fixed to the pipe joint after passing through the bending tube.

[0134] Of course, if the bending tube is not provided, the bending assembly 110 is omitted accordingly, and the operation handle 100 is further simplified.

[0135] Specifically, the control assembly 120 comprises a first support body 121, a first driving member 122 rotatably sleeved on the outer periphery of the first support body 121, a guide slot hole 125 extending along the axial direction is formed in the side wall of the first support body 121, a first connecting member 123 is slidingly installed in the interior of the first support body 121, a guide key 124 extending out of the guide slot hole 125 is arranged on the first connecting member 123, and the inner wall of the first driving member 122 is provided with a threaded structure matched with the guide key 124.

[0136] On the first support body 121, with reference to an embodiment, the first support body 121 is in a cylindrical shape, the guide slot hole 125 extending along the axial direction is formed in the side wall of the first support body 121, the first connecting member 123 is slidingly installed in the interior of the first support body 121, the guide key 124 extending out of the guide slot hole 125 is arranged on the first connecting member 123, and the inner wall of the first driving member 122 is provided with a threaded structure matched with the guide key 124.

[0137] Specifically, the first support body 121 is in a substantially cylindrical shape, which can be in an integrated structure or a split structure (such as Figure 4 When the first driving member 122 rotates, the first connecting member 123 is driven to slide in the interior of the first support body 121 through the guide key 124, and the first connecting member 123 does not rotate, i.e., only moves axially, due to the limitation of the guide slot hole 125.

[0138] The front end handle 130 is fixedly connected with respect to the first support body 121, the proximal end of the catheter 200 is fixedly inserted on the front end handle 130, and the proximal end of the sheath tube 300 is fixedly installed on the first connecting member 123, and the sheath tube 300 extends to the distal end through the catheter 200.

[0139] On the cooperation relationship between the first support body 121 and the second support body 111, with reference to an embodiment, the second support body 111 is in a cylindrical shape and is coaxially arranged with the first support body 121, and an integrated structure or a split fixed structure is adopted between the second support body 111 and the first support body 121.

[0140] On the cooperation relationship between the second driving member 112 and the second support body 111, with reference to an embodiment, the second driving member 112 is rotatably installed with respect to the second support body 111, the second support body 111 is provided with an operation port 116, a part of the second driving member 112 is located in the interior of the second support body 111, and at least a part thereof is exposed to the operation port 116 as a force applying part 117, and the second connecting member 113 is located in the interior of the second support body 111 and is linked with the second driving member 112.

[0141] Specifically, the bending adjustment component 110 includes a second support body 111, which is also substantially cylindrical and fixed relative to the first support body 121. The second support body 111 itself can adopt an integral or radially buckled split structure (such as Figure 4 ), the second support body 111 and the first support body 121 are coaxially arranged and fixedly docked in a split manner.

[0142] Correspondingly, the bending adjustment component 110 also includes a second driving member 112. In the specific setting of the second driving member 112, referring to one 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.

[0143] Specifically, the second driving member 112 is rotatably installed relative to the second support body 111, and 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.

[0144] To limit the movement of the second connecting member 113, referring to one embodiment, the inner wall of the second support body 111 is provided with an axially extending guide bar 114. At least a portion of the second connecting member 113 is located within 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. In this embodiment, the cooperation between the guide groove 115 and the guide bar 114 allows the second connecting member 113 to slide only in the axial direction relative to the second support body 111.

[0145] As will be readily understood from the foregoing, the bending adjustment function of the operating handle 100 is primarily achieved through the rotation of its components. To prevent the components from shifting relative to each other during operation, resulting in an unstable bending state, a corresponding limiting mechanism may be provided. Referring to one embodiment, the first drive member 122 is rotatably mounted on the outer periphery of the first support body 121, and a limiting mechanism is provided between the front handle 130 and the first drive member 122 to limit the rotational angle of the first drive member 122.

[0146] Accordingly, this embodiment exemplarily provides a setting method of a limit mechanism. Referring to an embodiment, the limit mechanism includes:

[0147] a sliding key 131 mounted on one of the front handle 130 and the first driving member 122;

[0148] The locking hole 126 is defined in the other of the front handle 130 and the first driving member 122 .

[0149] When the sliding key 131 engages with the lock hole 126, the position of the front handle 130 and the first driving member 122 in the circumferential direction is determined, and thus the axial position of the first connecting member 123 relative to the front handle 130 is determined, and the function of the operating handle 100 for adjusting the bending is limited, ensuring the stability during use. In the actual product, the specific setting can refer to an embodiment, the outer wall of the front handle 130 is provided with a sliding groove 132, and the sliding key 131 is installed in the sliding groove 132, and the lock hole 126 is provided on the end face of the first driving member 122 in the axial direction.

[0150] The lock hole 126 can realize the locking of the first driving member 122 in multiple positions by increasing the number of itself. Referring to Figure 3b , the lock hole is provided with multiple on the end face of the first driving member 122 in the axial direction, and is arranged in sequence along the peripheral surface of the first driving member 122. The increase in the number of the lock hole 126 can increase the locking position of the first driving member 122, but correspondingly, the increase in the number of the lock hole 126 will increase the manufacturing difficulty of the first driving member 122 and reduce the gap between adjacent lock holes 126, thereby reducing the strength of the single lock hole 126, so the specific number can be adjusted according to the design needs, actual working conditions and actual product size.

[0151] Because the first driving member 122 is a split structure of upper and lower buckling, the lock hole 126 close to the separation has two kinds of settings, one of which is open towards the separation, and the other is to avoid the separation to realize the closed setting. In the specific product, only one of the two setting modes may appear.

[0152] Correspondingly, the first driving member 122 and the first support body 121 can also be provided with a limiting mechanism to realize the above-mentioned function. Referring to an embodiment, the limiting mechanism includes a locking pin (not shown in the figure) which is screwed on the first driving member 122 and abuts against the first support body 121. The screw connection of the locking pin and the first driving member 122 can realize the relative position of itself and the first driving member 122, thereby realizing 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 above-mentioned limiting mechanism is also realized, and thus the locking principle is not repeated.

[0153] An embodiment of the present application provides a sheath core assembly for conveying an interventional instrument, which comprises a core tube, a locking piece fixed to the distal end of the core tube for connecting the interventional instrument, and a bending tube sleeved on the outer periphery of the core tube, the distal ends of the bending tube and the core tube are fixedly connected to each other, and the proximal ends of the two are relatively slidable. The sheath core assembly 400 comprises an inner and outer nested bending tube 410 and a core tube 425, the bending tube 410 is wrapped outside the core tube 425, the distal ends of the two are fixedly connected to each other, and the proximal ends of the two are relatively slidable, wherein the proximal end of the bending tube 410 is fixed to the second connecting piece 113, the proximal end of the core tube 425 extends out of the second connecting piece 113 and is fixed to the tail end of the second support body 111, i.e., the proximal end side, in order to facilitate the butt joint with the external pipe, the proximal end of the core tube 425 is provided with a pipe joint, for example, a luer joint 118 or the like.

[0154] When the interventional instrument needs to be released or recovered, the first driving piece 122 is rotated to axially move the first connecting piece 123, i.e., to drive the sheath tube 300 to move relative to the sheath core assembly 400. When bending is needed, the second driving piece 112 is rotated to axially move the second connecting piece 113, i.e., to drive 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 fixedly connected to each other, the relative movement of the proximal ends will cause the distal ends of the two to be deflected and bent together in the radial direction.

[0155] Referring to Figures 5a-11 , the sheath core assembly 400 comprises a bending tube 410 and a core tube assembly 420, wherein the core tube assembly 420 comprises a core tube 425, the distal end of the core tube 425 is provided with a locking piece 422 for connecting the interventional instrument, the bending tube 410 is sleeved on the outer periphery of the core tube 425, and the distal ends of the bending tube 410 and the core tube 425 are fixedly connected to each other, and the proximal ends of the two are relatively slidable.

[0156] The distal end side of the bending tube 410 extends adjacent to the proximal end side of the locking piece 422, the bending tube 410 can be directly fixed with the core tube 425, or directly fixed with the proximal locking piece 422, or both, the bending tube 410 and the core tube 425 can both adopt a metal material such as a hypotube, and are fixed by welding, bonding or fasteners.

[0157] The distal end of the core tube 425 further extends out of the locking piece 422 and is fixed with a guide head 421. The distal end of the guide head 421 has a round head structure with converging shape to facilitate the in-vivo guiding and advancing, and the position between the guide head 421 and the locking piece 422 serves as a loading position of the interventional instrument, and the interventional instrument in a compressed state is located in this position and is limitedly matched with the locking piece 422.

[0158] In one embodiment, the inner core 424 is inserted into the core tube 425, the distal end of the inner core 424 extends out of the locking member 422 and is fixed with the guide head 421, the proximal end of the inner core 424 extends to a certain length, which is not strictly limited, and the position on the outer periphery of the inner core between the guide head and the locking member is the loading position of the interventional instrument, the interventional instrument in the compressed state is located in this position and is limited by 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 relative to the core tube 425, and thus the radial space of the loading position is expanded.

[0159] Referring to Figure 5a and Figure 5b In some embodiments, the locking member adopts a wire control mode, the proximal end of the interventional instrument 500 is provided with a connecting ear 501, the connecting ear 501 is generally provided with a hanging hole or a hook for inserting the pull wire 4223, the locking member 422 is provided with a locking hole 4221, the distal end of the locking rod 4224 is matched with the locking hole 4221, and the proximal end can extend to the operation handle.

[0160] In the loading state, the pull wire 4223 is sleeved on the locking rod 4224 after passing through the connecting ear 501, and since the distal end of the locking rod 4224 is inserted into the locking hole 4221, the connecting ear 501 can be limited from being pulled out of the locking member 422 by the pull wire 4223. When it is needed to be released, the locking rod 4224 is pulled towards the proximal end and is pulled out of the locking hole 4221, and the pull wire 4223 is also released, so that the connecting ear 501 is allowed to be pulled out of the locking member 422.

[0161] When there are multiple connecting ears 501, multiple pull wires 4223 can be configured, and each pull wire 4223 extends towards the distal end through a wire distribution disc 4222. In order to regularize the wire bundle, a wire sleeve 4225 can be sleeved on the outer periphery of the core tube 425 to form an extension channel of the pull wire 4223.

[0162] The matching locking rod 4224 and the locking hole 4221 form a set of locking mechanisms, and multiple sets of locking mechanisms can be configured according to needs and are arranged in sequence along the circumference of the locking member 422.

[0163] Referring to Figure 5c In some embodiments, one or more limiting grooves are arranged on the outer periphery of the locking member 422, the interventional instrument is provided with a connecting ear which is arranged in the limiting groove, the limiting groove is used for axial limiting of the interventional instrument, and only allows the interventional instrument to be released after radial expansion. In order to prevent the connecting ear from being accidentally pulled out or suddenly outwardly poked to hurt the tissue when being released, a pressing strip 423 matched with each limiting groove is further fixed on the locking member 422. After loading, the pressing strip 423 is bound by the sheath to limit the connecting ear in the limiting groove, which further improves the safety, and the flexible pressing strip 423 is outwardly turned to allow the connecting ear to be pulled out of the locking member 422 when being released.

[0164] The inner core 424 and the core tube 425 are both tubular structures, and no axial relative movement is required between the core tube 425 and the inner core 424, so the two are nested and welded together, and one or more welding points can be provided. If necessary, a bushing can be added at the welding site to fill the radial gap between the two, and the inner core 424 and the core tube 425 are welded to the bushing, which can be made of the same material as the core tube 425.

[0165] 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 to the operating handle.

[0166] In an embodiment, in order to facilitate bending, the core tube 425 includes a compliant section 4251 adjacent to the lock 422, and a third extension section 4252 opposite the compliant section 4251 and extending proximally. The compliant section has a smaller stiffness than the third extension section, that is, it has better flexibility and is easier to bend.

[0167] In an embodiment, the compliant section 4251 is a hypotube or a spring tube (i.e., a tube wall with a helically extending reinforcing rib), and the length ranges from 120mm to 180mm, for example, 150mm.

[0168] The third extension section 4252 is a hypotube or a steel cable tube (woven or twisted with metal wires); the steel cable tube can be wrapped with a PTFE film for lubrication.

[0169] In other embodiments, the core tube 425 is a whole hypotube. The hypotube can not only ensure axial support but also be radially bent. 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 or lightly cut area becomes the reinforcing rib). The reinforcing rib can extend to the proximal end of the core tube 425, but since there is no obvious need for bending near the proximal end of the core tube 425, the reinforcing rib can also extend to the middle or slightly near the proximal end of the core tube 425.

[0170] Referring to Figure 7 , Figure 8 When the compliant section 4251 is cut, the width of the cutting seam (i.e., the diameter of the laser spot) is 0.1-1mm, and the seam spacing (i.e., the uncut part between adjacent cutting seams) is 0.1-1mm; wherein a uncut part is axially extended to form a reinforcing rib 4253.

[0171] In some embodiments, the core tube is the object to be bent, and the compliant section is configured to have a smaller limit curvature radius as it is closer to the distal end. This can make the distal end of the core tube more adaptable to complex paths. In terms of the compliant section, at least one of the following methods can be used, for example:

[0172] The slit width gradually changes in the compliant section, and the slit width is larger as it is closer to the distal end.

[0173] The slit distance gradually changes in the compliant section, and the slit distance is smaller as it is closer to the distal end.

[0174] The rigidity (flexibility) gradually changes in the compliant section, and the rigidity is lower as it is closer to the distal end.

[0175] Referring to Figures 9-11 The bending tube 410 is sleeved outside the core tube 425, and the bending tube 410 sequentially comprises a pulling section and a second extension section 413 from the distal end to the proximal end, wherein the pulling section is an integral structure and adopts a hypotube.

[0176] The distal end side of the pulling section extends close to the proximal end side of the locking piece 422, and is fixed with the core tube 425. In order to prevent the pulling section from being reversed during processing, different marks such as punching can be made at both ends of the pulling section to identify the assembly direction of the distal end and the proximal end.

[0177] The pulling section sequentially comprises a first pulling section 411, a transition section 414 and a second pulling section 412 from the distal end to the proximal end.

[0178] In the present application, the bending tube 410 is outside the core tube 425, that is, the main part of the force is outside, and the passive part is inside, so that a larger bending angle can be allowed compared with the case where the main part is inside and the passive part is outside.

[0179] The first pulling section 411 is formed with a reinforcing rib 4111 in a cutting manner, and the reinforcing rib 4111 is 180 degrees away from the circumferential position of the reinforcing rib 4253 of the compliant section 4251.

[0180] The second pulling section 412 is also cut, and the cutting slit width of the first pulling section 411 and the second pulling section 412 is respectively 0.03-0.5mm, and the slit distance is 0.2mm-0.85mm; wherein the first pulling section 411 is at the expected bending position, and should be relatively soft and more flexible, and the second pulling section 412 is relatively hard, but in order to ensure a certain softness, it can be bent during transportation and packaging, and after entering the human body during surgery, it can be bent according to the blood vessels, so the cutting method is adopted, and the slit width and the slit distance can be adjusted according to the softness requirements of different sections during actual operation.

[0181] The second pulling section 412 is provided with a reinforcing rib 4121 and a reinforcing rib 4122 formed by cutting, the two reinforcing ribs are diametrically opposite, that is, 180 degrees away from the circumferential position, and both are 90 degrees away from the circumferential position of the reinforcing rib 4111 of the first pulling section 411.

[0182] The transition section 414 is not cut, and 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.

[0183] The second extension section 413 does not have special bending requirements, and mainly bears the transmission of the pulling force, for example, a hypotube is not additionally cut, and extends to the proximal end and is connected to the operating handle.

[0184] During the bending process, the first pulling section 411 and the compliant section 4251 are mainly bent to a large extent, so the bending angle is generally required to be > 270° when cutting the hypotube, and the single reinforcing structure of the first pulling section 411 and the compliant section 4251 respectively ensures that the bending stress is not stretched, and the softness of the first pulling section 411 and the compliant section 4251 is moderate after being overlapped inside and outside, which is easy to bend and ensures the transmission of force. Overall, the bending tube 410 is 5mm-10mm longer than the core tube 425 to match the axial offset after bending, and the core tube 425 and the sheath tube 300 are passive during bending, and the bending tube 410 is active.

[0185] Referring to Figures 12-13 , in order to adapt to the change of the distal direction during bending or in-vivo passing, the outermost sheath tube 300 also has different softness distribution at different axial positions, and the sheath tube 300 includes a loading section 310, a bending section 320, and a first extension section 330 from the distal end to the proximal end. During use, the bending mainly occurs on the proximal side of the loading area adjacent to the interventional instrument 500, that is, the bending section 320.

[0186] Referring to Figures 14-15d , the nesting 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 illustrated in an embodiment, and the approximate axial position relationship of each section of the sheath tube 300, the core tube assembly 420, and the bending tube 410 is also illustrated in Figure 15d . 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 improved in the present application.

[0187] Referring to Figures 16-18 , the nesting relationship of the sheath tube 300 and the core tube assembly 420 (without setting the bending tube 410, compared with the foregoing) and the release process of the interventional instrument are illustrated in an embodiment, and the approximate axial position relationship of each section of the sheath tube 300 and the core tube assembly 420 is also illustrated in Figure 15dThe sheath tube 300 is also shown in the approximate axial position of each section of the core tube assembly 420. For each section, the sheath tube 300 adopts a multi-layer composite structure, i.e. for a section, the multi-layer structure is adopted and different components are included in the processing. The structure and process of the sheath tube 300 are also one of the improvements of the present application. In the embodiment, the core tube assembly 420 includes a core tube 425, the core tube 425 is fixed with a locking piece 422, the core tube 425 further extends the locking piece 422 at the distal end and is fixed with a guide head 421 at the most distal end. The distal end of the guide head 421 has a converging round head structure to facilitate the in-vivo threading and advancing, and the position between the guide head 421 and the locking piece 422 serves as a loading position of the interventional instrument. The compressed interventional instrument is located in the position and is limited by the locking piece 422.

[0188] In an embodiment, the core tube 425 is provided with an inner core 424, the distal end of the inner core 424 extends out of the locking piece 422 and is fixed with the guide head 421, the distal end of the core tube 425 only extends to the locking piece 422, and the extension length of the proximal end 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 relative to the core tube 425, so that the radial space of the loading position is expanded.

[0189] In an embodiment of the present application, a sheath tube for conveying an interventional instrument is provided, the distal end of the sheath tube is a loading section 310 and is used to accommodate the interventional instrument, the loading section 310 adopts a multi-layer structure and sequentially includes an inner liner tube 375, a metal tube and an outer wrapping film 380 from inside to outside, wherein the metal tube includes a main tube 350 and a head tube 340 from the proximal end to the distal end; the head tube 340 can adopt Figures la-ld The distal end structure of the sheath tube of each embodiment involved in the present application.

[0190] The main tube 350 and the head tube 340 can adopt an integrated cutting structure or a split butt joint structure.

[0191] When the split butt joint structure is adopted, for example, the head tube 340 is provided with a first connecting head 343 at the proximal end side of the body section, the distal end side of the main tube 350 is provided with a second connecting head 351, and the first connecting head 343 and the second connecting head 351 are embedded and complementary in shape. The mutual interpenetrating nesting and the like can also be adopted.

[0192] In another embodiment of the present application, a sheath tube for conveying an interventional instrument is provided, the sheath tube is sequentially divided into a loading section 310, a bending section 320 and a first extension section 330 from the distal end to the proximal end in the axial direction, wherein the loading section 310 is used to accommodate the interventional instrument 500, the sheath tube adopts a multi-layer structure and includes:

[0193] an inner sheath tube 370, which is distributed in the bending section and the first extension section in the axial direction;

[0194] The inner liner tube 375 is butted against the distal end of the inner sheath tube 370 and is distributed in the loading section in the axial direction;

[0195] The metal tube is wrapped around the outer periphery of the distal end portion of the inner sheath tube and the inner liner tube and is distributed in the loading section and the bending section in the axial direction. The metal tube comprises, from the distal end to the proximal end, a head tube 340, a main tube 350 and an extension tube 360 arranged in sequence. 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. The head tube 340 can be made of Figures la-ld The sheath tube distal end structure of each embodiment involved in the present application;

[0196] The outer wrapping film 380 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.

[0197] The loading section 310 has a larger diameter relative to the proximal end portion of the sheath tube in the loading section 310, i.e. the bending section 320 and the first extension section 330, because it needs to wrap the interventional instrument. Figure 19 The partial visible components of the sheath tube 300 are shown. The distal end portion of the sheath tube 300 has a structure of at least three layers in general, the inner and outer layers are both made of polymer material, and the middle layer is a metal tube.

[0198] The bending section can be bent to change the direction of the distal end of the sheath tube during delivery, and the first extension section mainly provides sufficient axial pushing force and pulling force and has sufficient length to connect the operation handle.

[0199] The head tube 340 is cut from a nickel-titanium alloy tube, and the main tube 350 and the extension tube 360 are respectively cut from stainless steel tubes. The head tube 340 and the main tube 350 have a larger tube diameter relative to the extension tube 360 because they need to wrap the interventional instrument, and the head tube 340 and the main tube 350 are combined with Figure 19 the axial position relationship to correspondingly expand and change the diameter at the joint between the main tube 350 and the extension tube 360.

[0200] To prevent the metal material of the middle layer from scratching the blood vessel wall, the outermost layer at least wraps the head tube 340, the main tube 350 and the extension tube 360. The outer wrapping film 380 of the outermost layer can be made of polymer material. Since the metal material part is a multi-section structure, the outer wrapping film 380 is also a multi-section splicing structure during processing and is then fused into one body.

[0201] For example, the outer wrapping film 380 comprises multiple sections along the axial direction of the sheath tube, and each section is made of different material, or at least two sections are made of the same material.

[0202] In one embodiment, the outer wrapping film strength corresponding to the main tube 350 is greater than the outer wrapping film strength corresponding to the distal end of the head tube 340.

[0203] The inner layer includes an inner sheath 370 and an inner liner 375, the inner sheath 370 extends to the proximal end on one side and to the joint of the main tube 350 and the extension tube 360 on the other side, and the inner sheath 370 further extends to the distal end side of the head tube 340 through the inner liner 375 from the joint of the main tube 350 and the extension tube 360, wherein the inner liner 375 can be made of PTFE material.

[0204] The axial position of the distal end portion of the extension tube 360 corresponds to the compliant section 4251 and the first pull section 411, and the extension tube 360 can also be formed with a reinforcing rib by cutting.

[0205] Referring to Figures 20-24 , the inner sheath 370 itself adopts a multi-layer structure, from the inside to the outside in turn PTFE inner layer 3701, woven layer 3702, woven layer 3704, and outer layer 3705, wherein two reinforcing ribs 3703 extending along the axial direction are fixedly wrapped between the woven layer 3702 and the woven layer 3704.

[0206] One of the two reinforcing ribs 3703 is 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.

[0207] The woven layer 3702 and the woven layer 3704 do not require a clear layered structure, and can be woven into one and hold the reinforcing rib, and the outer layer 3705 can be made of Pebax material.

[0208] The reinforcing rib 4253 is arranged in the compliant section 4251, and the reinforcing rib 4111 is arranged in the first pull section 411, and the circumferential positions of the reinforcing rib 4253 and the reinforcing rib 4111 are staggered by 180 degrees.

[0209] The sheath in the cross-sectional view only shows part of the extension tube 360, and the extension tube 360 can be provided with a reinforcing rib 3601, and the reinforcing rib 3601 is at the same circumferential position as the reinforcing rib 4253 on the same side in the radial direction;

[0210] Or in other embodiments, two reinforcing ribs are arranged in the extension tube 360, which are reinforcing rib 3601 and reinforcing rib 3602, wherein the reinforcing rib 3601 is at the same circumferential position as the reinforcing rib 4253 on the same side in the radial direction, and the reinforcing rib 3602 is at the same circumferential position as the reinforcing rib 4111 on the same side in the radial direction, that is, 180 degrees away from the circumferential position of the reinforcing rib 4253.

[0211] The inner sheath tube 370 exists in the suitable bending section 320 and the first extension section 330. Since the suitable bending section 320 has a greater bending angle during bending, the inner sheath tube 370 has different strengths in the suitable bending section 320 and the first extension section 330. The inner sheath tube 370 is softer in the suitable bending section 320. For example, the outer layer 3705 of the inner sheath tube 370 in the suitable bending section 320 adopts Pebax of 30-59D, the outer layer 3705 of the inner sheath tube 370 in the first extension section 330 adopts Pebax of 60-90D, and the braided layer and the PTFE inner layer 3701 at different positions of the inner sheath tube 370 can adopt the same setting.

[0212] Referring to Figure 25 The bending system of the present application can actively change the orientation of the distal end by pulling the bending tube at the operating handle, and can better adapt to the delivery of complex paths. Since the bending tube pulls the core tube assembly, the interventional instrument loaded on the core tube assembly does not change the orientation when the sheath tube is retracted to release the interventional instrument, and the misalignment risk during the release process can be avoided.

[0213] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure. When technical features in different embodiments are embodied in the same figure, it is considered that the figure also discloses the combination of the embodiments involved.

[0214] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patentable scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application.

Claims

1. A sheath distal structure for delivering an interventional device, comprising a tubular body segment having a distal end and a proximal end opposite to each other, wherein a plurality of elastic expansion pieces are circumferentially spaced apart on the distal end of the body segment, each expansion piece having a closed state extending axially along the body segment and an everted state spaced apart from each other, characterized in that: A connecting strip is provided between two adjacent expansion pieces, with both ends of the connecting strip being connected to the expansion pieces on the corresponding sides, and the connection portion being adjacent to the distal end of the expansion piece; When the expansion pieces are in the enclosed state, the middle portion of the connecting strip is folded and stored in the interval area between two adjacent expansion pieces; When each expansion piece is in an outward-turned state, the middle portion of the connecting strip is relatively unfolded; A plurality of second hollow areas are arranged on the side wall of the main body segment.

2. The distal end structure of the sheath for delivering an interventional device according to claim 1, wherein: The distal side edge of each expansion piece is arc-shaped, and the connecting strip extends substantially along the tangent direction of the arc to connect to the distal side edge of the corresponding expansion piece.

3. The distal end structure of the sheath for delivering an interventional device according to claim 2, wherein: Two adjacent connecting strips are butted against the distal side edge of the same expansion piece, and the distal side edge of the butted portion has a smooth transition.

4. The distal end structure of the sheath for delivering an interventional device according to any one of claims 1 to 3, characterized in that: All the connecting strips extend continuously in the circumferential direction of the body segment.

5. The distal end structure of the sheath for delivering an interventional device according to claim 1, wherein: When the expansion pieces are in the enclosed state, the middle portion of the connecting strip is U-shaped at the proximal end, the bottom of the U-shape has two corner portions, and a protrusion is provided on the outer side of each corner portion.

6. The distal end structure of the sheath for delivering an interventional device according to claim 5, characterized in that: When each expansion piece is in the everted state, the two protrusions corresponding to the same U shape are adjacent to or abut against each other.

7. The distal end structure of the sheath for delivering an interventional device according to claim 1, wherein: There is a spacing opening between two adjacent expansion pieces. When the expansion pieces are in the enclosed state, the connecting strips extend from their two ends along an arc path into the spacing opening.

8. The distal end structure of the sheath for delivering an interventional device according to claim 7, wherein: When the expansion pieces are in the enclosed state, the proximal end side of the connecting strip is adjacent to the middle of the spacing opening in the axial direction of the main body segment.

9. The distal end structure of the sheath for delivering an interventional device according to claim 7, wherein: In the axial direction of the body segment, the middle portion of the spacing opening is widened and the two ends are narrowed.

10. The distal end structure of the sheath for delivering an interventional device according to claim 1, wherein: When each expansion piece is in the outward-turned state, the connecting strip is roughly V-shaped, and the top angle of the V-shape is greater than or equal to 120 degrees.

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