Cardiac pacemaker electrode lead delivery sheath

Abstract

Examples herein provide a cardiac pacemaker electrode lead delivery sheath, the delivery sheath including a sheath tube, the sheath tube including at least a first tube segment disposed at a distal end thereof, the first tube segment having a first curved segment and a second curved segment disposed at the distal end thereof, wherein an included angle between a first bending surface of the first curved segment and a second bending surface of the second curved segment is 45° or greater.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to a Chinese application filed on March 3, 2023, bearing application number 202310193884.6, the entire contents of which are incorporated herein by reference.

[0002] TECHNICAL FIELD This disclosure relates to the technical field of medical devices, and in particular to cardiac pacemaker electrode lead delivery sheaths. [Background technology]

[0003] A cardiac pacemaker is an electronic therapeutic device implanted in the body. It uses a pulse generator to emit electrical pulses powered by a battery, which are then conducted by the lead electrodes to stimulate the cardiac muscle in contact with the electrodes, causing the heart to operate and contract, thereby achieving the goal of treating cardiac dysfunction caused by certain arrhythmias. The most important step in cardiac pacemaker implantation surgery is the implantation of the cardiac pacemaker electrode leads.

[0004] In clinical operations, the physiological properties of selective site pacing (e.g., ventricular septum, conduction bundle, and atrial septum pacing) have been demonstrated in various studies. However, current electrode lead delivery sheaths have problems, such as only being able to achieve ventricular septum or conduction bundle pacing but not being able to fully achieve selective site pacing, or being able to fully achieve selective site pacing but requiring the implantation of a special electrode lead and not being able to implant other common electrode leads.

[0005] Based on this, it is desirable to provide a cardiac pacemaker electrode-lead delivery sheath that solves the electrode-lead compatibility problem and thereby fully realizes selective pacing. Summary of the Invention

[0006] One or more embodiments herein provide a cardiac pacemaker electrode lead delivery sheath, the delivery sheath including a sheath tube, the sheath tube including at least a first tube segment disposed at a distal end thereof, the first tube segment having a first curved segment and a second curved segment disposed at a distal end thereof, wherein an included angle between a first bending surface of the first curved segment and a second bending surface of the second curved segment is 45° or greater.

[0007] In some embodiments, the first folding plane is perpendicular to the second folding plane.

[0008] In some embodiments, the hardness of the first curved segment is less than the hardness of the second curved segment.

[0009] In some embodiments, the radius of curvature of the second curved segment ranges from 18 cm to 70 cm.

[0010] In some embodiments, a first reference triangle is formed by connecting the proximal end point, the distal end point, and the maximum bending point of the second curved segment, and in the first reference triangle, the length of the first connecting line is smaller than the length of the second connecting line, the value range of the first included angle at the maximum bending point is 80° to 120°, the first connecting line is a connecting line between the proximal end point and the maximum bending point, and the second connecting line is a connecting line between the distal end point and the maximum bending point.

[0011] In some embodiments, the proximal end point, the distal end point and the farthest bending point of the second curved segment are connected to each other to form a second reference triangle, and in the second reference triangle, the length of the third connecting line is smaller than the length of the fourth connecting line, the value range of the second included angle at the farthest bending point is 90° to 130°, the third connecting line is a line connecting the proximal end point and the farthest bending point, and the fourth connecting line is a line connecting the distal end point and the farthest bending point.

[0012] In some embodiments, the first tube segment includes at least a braided layer, the braided layer being braided with braiding yarn, the diameter range of the braiding yarn of the second curved segment being 0.04 mm to 0.06 mm, and the braid density range of the second curved segment being 50 to 70.

[0013] In some embodiments, the radius of curvature of the second curved segment is in the range of 10 cm to 15 cm.

[0014] In some embodiments, a first reference triangle is formed by connecting the proximal end point, the distal end point, and the maximum bending point of the second curved segment, and in the first reference triangle, the length of the first connecting line is smaller than the length of the second connecting line, the value range of the first included angle at the maximum bending point is 80° to 120°, the first connecting line is a connecting line between the proximal end point and the maximum bending point, and the second connecting line is a connecting line between the distal end point and the maximum bending point.

[0015] In some embodiments, the proximal end point, the distal end point and the farthest bending point of the second curved segment are connected to each other to form a second reference triangle, and in the second reference triangle, the length of the third connecting line is smaller than the length of the fourth connecting line, the value range of the second included angle at the farthest bending point is 90° to 130°, the third connecting line is a line connecting the proximal end point and the farthest bending point, and the fourth connecting line is a line connecting the distal end point and the farthest bending point.

[0016] In some embodiments, the first tube segment includes at least a braided layer, the braided layer being braided with braiding yarn, the diameter range of the braiding yarn of the second curved segment being 0.05 mm to 0.07 mm, and the braid density range of the second curved segment being 60 to 80.

[0017] In some embodiments, the second curved segment employs a two-ply braid.

[0018] In some embodiments, the radius of curvature of the first curved segment is in the range of 5 cm to 8 cm.

[0019] In some embodiments, the sheath tube further includes a second tube segment and a third tube segment, the second tube segment being located in a central portion of the sheath tube, the third tube segment being located at a proximal end of the second tube segment, and the hardness of the second tube segment being greater than the hardness of the first tube segment and less than the hardness of the third tube segment.

[0020] In some embodiments, the second tube segment and the third tube segment each include at least a braided layer, the braided layer being braided with braiding yarn, and the braid density of the second tube segment being less than the braid density of the third tube segment.

[0021] In some embodiments, the delivery sheath further includes a sheath base, the sheath tube further includes a cutting tube segment located at a proximal end and an implanting tube segment located at a distal end of the cutting tube segment, the first tube segment is located at the distal end of the implanting tube segment, the cutting tube segment includes a connection region and a buffer region located in order from proximal to distal along the axial direction of the sheath tube, the sheath tube is connected to the sheath base via the connection region, and the buffer region is configured to provide a cut resistance force between the sheath tube and the implanting tube segment.

[0022] In some embodiments, the cut resistance provided by the relief region tapers from proximal to distal along the axial direction of the sheath tube.

[0023] In some embodiments, the buffer area includes a first protrusion structure disposed on an inner wall of the buffer area.

[0024] In some embodiments, the thickness of the first projection structure tapers from proximal to distal along the axial direction of the sheath tube.

[0025] In some embodiments, the first protrusion structure includes a cutting guide groove, the width of the cutting guide groove tapering from proximal to distal along the axial direction of the sheath tube.

[0026] In some embodiments, the first protrusion structure includes a plurality of protrusions spaced apart along the axial direction of the sheath tube.

[0027] In some embodiments, the buffer region includes a second protrusion structure disposed on an inner wall of the buffer region, the thickness of the second protrusion structure tapering from proximal to distal along the axial direction of the sheath tube.

[0028] In some embodiments, the sheath base includes a side branch, a handle, and a sheath base body, the handle is connected to the sheath base body, one end of the side branch passes through the handle and communicates with the sheath base body, the other end of the side branch is provided with a valve, and at least one fitting is connected to the valve.

[0029] In some embodiments, the sheath base body has a passageway along the axial direction of the sheath tube, one end of the side branch communicates with the passageway, the passageway is configured to deliver a medical device, the sheath base body has a thin-walled structure along the axial direction of the sheath tube, and a locking block is provided on a side wall of the sheath base body.

[0030] In some embodiments, the delivery sheath further includes a sheath cap, the sheath cap including a sheath cap body having an instrument passageway along the axial direction of the sheath tube, and a locking groove on a side wall of the sheath cap body, the locking groove engaging with the locking block of the sheath base body.

[0031] In some embodiments, the delivery sheath further includes a hemostatic valve, the hemostatic valve being located within the passage of the sheath base body, the hemostatic valve being provided with a circular hole structure and an elastic structure for passing the medical device through the hemostatic valve, and the elastic structure being located at a distal end of the circular hole structure and configured to open and close the circular hole structure.

[0032] In some embodiments, the material of the first curved segment comprises a developer material. [Brief explanation of the drawings]

[0033] Further description will be given herein by way of illustrative examples, which are described in detail with reference to the drawings, which are not limiting, and in which like numbers refer to like structures, wherein: [Figure 1] 1 is a schematic structural diagram of a cardiac pacemaker electrode lead delivery sheath according to some embodiments of the present disclosure; [Figure 2] 10A-10C are exemplary schematic diagrams of multiple three-dimensional bending molds for a first tube segment according to some embodiments herein. [Figure 3] 3A and 3B are exemplary schematic diagrams of a first reference triangle and a second reference triangle according to some embodiments of the present disclosure; [Figure 4] 1 is a schematic structural diagram of a sheath tube structure according to some embodiments of the present disclosure. [Figure 5] 1 is an exemplary schematic diagram of a braided layer according to some embodiments herein. [Figure 6] FIG. 10 is an exemplary schematic diagram of a braided layer according to some other embodiments herein. [Figure 7] 1 is a schematic structural diagram of a connection point between a sheath base and a sheath tube according to some embodiments of the present disclosure. [Figure 8] 10A and 10B are schematic structural diagrams of a connection point between a sheath base and a sheath tube according to some other embodiments of the present disclosure. [Figure 9]1 is a schematic structural diagram of a sheath base according to some embodiments herein. [Figure 10] 1A-1C are schematic structural diagrams of a sheath base body and handle connection according to some embodiments of the present disclosure; [Figure 11] 1 is a schematic structural diagram of a sheath cap according to some embodiments of the present disclosure. [Figure 12] 1 is a schematic structural diagram of a hemostasis valve according to some embodiments of the present disclosure. [Figure 13] 1 is a schematic structural diagram of an outlet opening of a hemostasis valve according to some embodiments of the present disclosure. [Figure 14] 1 is a schematic structural diagram of an outlet closure of a hemostasis valve according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0034] In order to more clearly describe the technical solutions of the embodiments of this specification, the following briefly introduces the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some examples or embodiments of this specification, and those skilled in the art can also apply this specification to other similar scenarios based on these drawings without any creative efforts. Unless obvious from the language environment or otherwise explained, the same symbols in the drawings represent the same structures or operations.

[0035] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are ways of distinguishing between different components, elements, members, parts, or assemblies at different levels, however, other terms may be substituted for the terms if they achieve the same purpose.

[0036] As used herein and in the claims, terms such as "a," "one," "one kind," and / or "the" do not specifically refer to the singular but may include the plural, unless the context clearly indicates an exceptional circumstance. Generally, the terms "comprise" and "include" refer only to the inclusion of explicitly identified steps and elements, and do not constitute an exclusive list, and a method or apparatus may include other steps or elements.

[0037] Arrhythmia is a general term for symptoms such as irregular heartbeats, being too fast or too slow, caused by abnormalities in the heart's electrical conduction system. Treatment methods for arrhythmia include drug therapy and non-drug therapy, but drug therapy can only control the heartbeat to a certain extent, and pacemaker implantation is currently the main method of treating chronic arrhythmias. The most important step in cardiac pacemaker implantation surgery (hereinafter referred to as implantation surgery) is the implantation of cardiac pacemaker electrode leads.

[0038] In clinical surgery, cardiac pacemaker electrode lead implantation requires guidance and support via an auxiliary sheath tube. The specific operational steps are to first insert the sheath tube into the cardiac chamber and then feed the electrode lead along the sheath tube into the cardiac chamber. After the electrode is fixed, the sheath tube needs to be removed from the body. However, because other testing devices are installed on the other end connected to the electrode, they interfere with the removal of the sheath tube. Therefore, the sheath tube must be cut along its axial direction to complete the removal of the entire sheath. When cutting, the operator (e.g., a physician) needs to precisely control the magnitude of the force, which places higher demands on the operator and is difficult to control, potentially causing unnecessary injury to the patient.

[0039] In addition, in clinical operations, the physiological properties of selective site pacing (e.g., ventricular septum, conduction bundle, and atrial septum pacing) have been demonstrated in various studies. However, current electrode lead delivery sheaths have problems, such as only being able to achieve ventricular septum or conduction bundle pacing but not being able to fully achieve selective site pacing, or being able to fully achieve selective site pacing but requiring the implantation of a special electrode lead and not being able to implant other common electrode leads.

[0040] 1 is a schematic structural diagram of a cardiac pacemaker electrode lead delivery sheath according to some embodiments of the present specification. As shown in FIG. 1, the cardiac pacemaker electrode lead delivery sheath (hereinafter referred to as delivery sheath) provided in some embodiments of the present specification includes a sheath tube 1, which includes at least a first tube segment 11 installed at its distal end. The first tube segment 11 is provided with a first curved segment 111 and a second curved segment 112, and the first curved segment 111 is located at the distal end of the first tube segment 11. Here, the included angle between the first bending surface of the first curved segment 111 and the second bending surface of the second curved segment is 45° or more.

[0041] The sheath tube 1 is a tubular structure for delivering an electrode lead. In some embodiments, the sheath tube 1 may be a one-piece structure or a separate structure. In some embodiments, the sheath tube 1 may be formed by rheological composite processing. In some embodiments, the sheath tube 1 may be divided into multiple tube segments, such as three segments, five segments, or ten segments, depending on the actual situation. For example, the sheath tube 1 may include a first tube segment 11 and a second tube segment 12 and a third tube segment 13, which will be described later. In some embodiments, all or some of the tube segments of the sheath tube 1 include at least a braided layer. For more details about the braided layer, please refer to Figures 4 to 6 and their related descriptions.

[0042] The first tube segment 11 is a sheath tube segment located at the distal end of the sheath tube 1. The first curved segment 111 is a sheath tube segment located at the distal end of the first tube segment 11, and the second curved segment 112 is a sheath tube segment located at the proximal end of the first tube segment 11. Here, the proximal end refers to the end closer to the operator, and the distal end refers to the end farther from the operator. In some embodiments, the first curved segment 111 and the second curved segment 112 may be connected to each other (as shown in FIG. 1 ) or may be spaced apart (e.g., another curved segment may be provided between the first curved segment 111 and the second curved segment 112).

[0043] In some embodiments, both the first curved segment 111 and the second curved segment 112 may be designed to be curved (i.e., the first tube segment 11 is curved), and the structural shape of the first tube segment 11 may be matched to the different chamber structures of the heart to better perform selective site pacing. In some embodiments, different curved segments may be made of different materials or have different hardnesses. Therefore, the first curved segment 111 and the second curved segment 112 may be distinguished by differences in hardness or material, and the positions of their ends, i.e., their respective start and end positions, may be determined.

[0044] In some embodiments, the material of the first curved segment 111 includes at least a developer material. A developer material is a material that has a developer effect or function. Exemplary developer materials include, but are not limited to, bismuth carbonate (Bi2O2CO3), barium sulfate (BaSO4), tungsten (W), etc.

[0045] As can be understood, the first curved segment 111 is located at the distal end of the first tube segment 11, that is, at the distal end (i.e., the tip) of the sheath tube 1. Therefore, if a developing material is filled or added to the material of the first curved segment 111, the tip of the sheath tube 1 can be made developable, making it easier to track the position of the tip of the sheath tube and realizing accurate positioning of the tip of the sheath tube, thereby ensuring operation accuracy during surgery.

[0046] The first bending plane is a plane on which a triangle is located, which is formed by connecting any point (e.g., the proximal end point, the distal end point) at both ends of the first curved segment 111 with the maximum bending point or the farthest bending point. For example, the first bending plane may be a horizontal plane. The second bending plane is a plane on which a triangle is located, which is formed by connecting any point (e.g., the proximal end point, the distal end point) at both ends of the second curved segment 112 with the maximum bending point or the farthest bending point. For example, the second bending plane may be a vertical plane. For a specific description of the proximal end point, the distal end point, the maximum bending point, and the farthest bending point, please refer to FIG. 3 and its related description.

[0047] In some embodiments, there is an included angle between the first bending surface of the first curved segment 111 and the second bending surface of the second curved segment 112. That is, the first curved segment 111 and the second curved segment 112 lie in different planes, and the first curved segment 111 and the second curved segment 112 are curved in different planes, i.e., the first tube segment 11 exhibits a three-dimensional curve.

[0048] In some embodiments, the angle between the first and second folding surfaces is 45° or greater. In some embodiments, the angle between the first and second folding surfaces may be 45° to 54°. In some embodiments, the angle between the first and second folding surfaces may be 55° to 64°. In some embodiments, the angle between the first and second folding surfaces may be 65° to 74°. In some embodiments, the first folding surface is perpendicular to the second folding surface, i.e., the angle between the first and second folding surfaces is 90°.

[0049] For more details on the sheath tube, please refer to the descriptions in other parts of this specification (for example, the related descriptions in FIGS. 2 to 8).

[0050] In some embodiments herein, the distal end of the sheath tube is designed to be three-dimensionally curved, which can better match the different chamber structures of the heart and establish a passage for delivering the electrode lead, allowing the tip of the electrode lead to reach the target pacing site, thereby realizing selective site pacing.

[0051] Different curved segments of the first tube segment 11 have different hardnesses. In some embodiments, the second curved segment 112 is made of a material with a high hardness because it needs to create and maintain a predetermined curved shape. Meanwhile, the first curved segment 111 is located at the distal end (i.e., the tip) of the sheath tube 1 and primarily plays a guiding role during the implantation procedure, and needs to adapt to changes in the shape of the blood vessel as well as avoid damaging the blood vessel wall. Therefore, the hardness of the first curved segment 111 is less than that of the second curved segment 112.

[0052] In some embodiments, the hardness range of the first curved segment 111 can be limited to better meet the deformation requirements of the first curved segment 111 and ensure its functionality and safety. In some embodiments, the hardness range of the first curved segment 111 may be 30D to 35D. In some embodiments, the hardness range of the first curved segment 111 may be 25D to 30D. In some embodiments, the hardness range of the first curved segment 111 may be 35D to 40D. By limiting the hardness of the first curved segment 111 within an appropriate range, the first curved segment 111 can adapt to various shape changes of a blood vessel, which not only can better guide a medical device such as an electrode lead but also can effectively avoid damage to the blood vessel wall.

[0053] In some embodiments, the hardness range of the second curved segment 112 can be limited to better maintain the preset curved shape of the second curved segment 112. In some embodiments, the hardness range of the second curved segment 112 can be 40D to 45D. In some embodiments, the hardness range of the second curved segment 112 can be 35D to 40D. In some embodiments, the hardness range of the second curved segment 112 can be 45D to 50D. By limiting the hardness of the second curved segment 112 within an appropriate range, the second curved segment 112 can better maintain the preset curved shape and can provide sufficient support for supporting the atrium or ventricle, thereby establishing a passage for a medical device such as an electrode lead.

[0054] In some embodiments, the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 can be limited to simultaneously satisfy the requirements for implantation guidance and maintaining a predetermined curved shape. In some embodiments, the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 may be 0.67 to 0.86. In some embodiments, the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 may be 0.70 to 0.80. In some embodiments, the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 may be 0.75 to 0.85. In some embodiments, the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 may be 0.65 to 0.80. In some embodiments, the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112 may be in the range of 0.70 to 0.90. As can be seen, by limiting the range of the ratio of the hardness of the first curved segment 111 to the hardness of the second curved segment 112, the hardness of the first curved segment 111 and the hardness of the second curved segment 112 can simultaneously meet the hardness requirements, which not only ensures that the first curved segment 111 does not damage the blood vessel wall during guiding, but also is advantageous for maintaining the preset curved shape of the second curved segment 112 to provide sufficient support.

[0055] 1 , the sheath tube 1 may further include a second tube segment 12 and a third tube segment 13, where the second tube segment 12 is located in the central portion of the sheath tube 1 and the third tube segment 13 is located at a more proximal end than the second tube segment 12. In other words, the second tube segment 12 is located between the first tube segment 11 and the third tube segment 13.

[0056] The second tube segment 12 is a sheath tube segment located in the central portion of the sheath tube 1, and the third tube segment 13 is a sheath tube segment located at the proximal end of the sheath tube 1. In some embodiments, the second tube segment 12 may directly connect the first tube segment 11 and the third tube segment 13. In some embodiments, the second tube segment 12 may indirectly connect the first tube segment 11 and the third tube segment 13 via another tube segment.

[0057] In some embodiments, the third tube segment 13 is located more proximal than the second tube segment 12, and therefore the operator must push the sheath tube 1 into the blood vessel along the third tube segment 13 during the implantation procedure. Therefore, the third tube segment 13 is made of a high-hardness material, and the second tube segment 12 is located between the first tube segment 11 and the third tube segment 13. To prevent the sheath tube 1 from bending due to the sudden change in hardness, the second tube segment 12 may be made of a medium-hardness material.

[0058] In some embodiments, the hardness of the second tube segment 12 is greater than the hardness of the first tube segment 11 and less than the hardness of the third tube segment 13. That is, the hardness of the sheath tube 1 gradually decreases from the proximal end to the distal end along the axial direction of the sheath tube 1. Here, the axial direction of the sheath tube 1 refers to the direction in which the centerline of the sheath tube 1 extends.

[0059] In some embodiments, the hardness range of the second tube segment 12 is 50D to 65D, and the hardness range of the third tube segment 13 is 67D to 72D. In some embodiments, the hardness range of the second tube segment 12 is 50D to 55D, and the hardness range of the third tube segment 13 is 67D to 68D. In some embodiments, the hardness range of the second tube segment 12 is 55D to 60D, and the hardness range of the third tube segment 13 is 69D to 70D. In some embodiments, the hardness range of the second tube segment 12 is 60D to 65D, and the hardness range of the third tube segment 13 is 71D to 72D.

[0060] As can be seen, by limiting or selecting the hardness range of the second tube segment 12 and the third tube segment 13, the hardness of the second tube segment 12 and the third tube segment 13 can be within an appropriate range, ensuring the pushability of the sheath tube 1 and effectively preventing the sheath tube 1 from bending, thereby ensuring the practicality and safety of the delivery sheath during the implantation procedure.

[0061] In some embodiments, the hardness of each tube segment (e.g., first tube segment 11, second tube segment 12, and third tube segment 13) of the sheath tube 1 may be related not only to the material used for each tube segment, but also to its structure. Therefore, the material or structure (e.g., the braiding method of the braided layer) used for each tube segment of the sheath tube 1 can be selected or designed to ensure that the hardness of each tube segment of the sheath tube 1 is within an appropriate range. For more details about the braided layer, please refer to Figures 4 to 6 and their related descriptions.

[0062] In some embodiments, the sheath tube 1 further includes a cutting tube segment disposed at the proximal end thereof and an implanting tube segment disposed at the distal end thereof, and the first tube segment 11, the second tube segment 12, and the third tube segment 13 may be part of the implanting tube segment. For more details about the cutting tube segment and the implanting tube segment, please refer to Figures 7-8 and their related descriptions.

[0063] In some examples, the delivery sheath may further include a sheath base, and at least a portion of the proximal end of the sheath tube 1 is located within the sheath base. The sheath base is a structure for controlling the delivery of the electrode lead. In some embodiments, the sheath tube 1 may be connected to the sheath base in various manners. Exemplary connection methods may include fastening, adhesion, etc. In some embodiments, a medical device may be introduced into the sheath tube 1 through the sheath base (e.g., a passage in the sheath base body) and further delivered to a target chamber (e.g., the right atrium of the heart) through the sheath tube 1. Here, the medical device refers to one or more devices required for the implantation procedure. For example, the medical device may include a guidewire, a dilator, an electrode lead, etc.

[0064] In some embodiments, the sheath base may include a side branch, a handle, and a sheath base body, the handle connected to the sheath base body, one end of the side branch passing through the handle and communicating with the sheath base body, the other end of the side branch having a valve on which at least one fitting is connected.

[0065] In some embodiments, the sheath base body has a passageway along the axial direction of the sheath base, and one end of the side branch communicates with the passageway, which is configured to deliver a medical device. In some embodiments, the sheath base body has a thin-walled structure along the axial direction of the sheath tube, and a locking block is provided on the side wall of the sheath base body. For more details about the sheath base, please refer to Figures 9-10 and their related descriptions.

[0066] In some embodiments, the delivery sheath may further include a sheath cap. The sheath cap is a structure that covers the proximal end of the sheath base body. In some embodiments, the sheath cap has an instrument passageway along the axial direction of the sheath tube and a locking groove on the side wall of the sheath cap that is engaged with a locking block on the sheath base body. In some embodiments, the sheath cap can be used to secure a hemostatic valve. For more information about the sheath cap, see FIG. 11 and its related description.

[0067] In some embodiments, the delivery sheath may further include a hemostatic valve. A hemostatic valve is a structure for preventing blood from leaking out of a blood vessel. In some embodiments, the hemostatic valve is disposed within a passageway of the sheath base body. In some embodiments, the hemostatic valve is provided with a circular hole structure and an elastic structure for passing a medical device therethrough, and the elastic structure is disposed at the distal end of the circular hole structure and configured to open and close the circular hole structure. For more details regarding the hemostatic valve, please refer to Figures 12 to 14 and their associated descriptions.

[0068] As described above, the first tube segment 11 may be designed with a three-dimensional curve to match different cardiac chamber structures and better perform selective site pacing. As can be appreciated, cardiac chamber structures differ from pacing sites, and the corresponding three-dimensional curved shape of the first tube segment 11 may also differ. In some embodiments, the cardiac chamber structure may include cardiac chamber shapes and cardiac chamber sizes.

[0069] FIG. 2 is an exemplary schematic diagram of multiple three-dimensional bending patterns of a first tube segment according to some embodiments of the present disclosure. By way of example only, as shown in FIG. 2, the three-dimensional bending patterns of the first tube segment 11 may include seven types: S, M, L, B, C, D, and E, which are denoted as S-type, M-type, L-type, B-type, C-type, D-type, and E-type, respectively. In the figure, the tube segment between points II and III is the first curved segment 111, and the tube segment between points I and II is the second curved segment 112. As can be seen from FIG. 2, the three-dimensional bending pattern of the first tube segment 11 depends on the curvature of the first curved segment 111 and the second curved segment 112, particularly the curvature of the second curved segment 112. In some embodiments, the curvature can be characterized by the curvature radius, where a smaller curvature radius corresponds to a larger curvature.

[0070] In some embodiments, the second curved segment 112 has a relatively large radius of curvature because it is primarily used to support the atrium or ventricle and needs to provide sufficient support to establish a passageway for the electrode lead, and the first curved segment 111 has a relatively small radius of curvature because it is primarily used to guide the tip of the electrode lead to reach the target pacing site.

[0071] In some embodiments, to smoothly advance the first tube segment 11 into the target chamber and guide the tip of the electrode lead to reach the target pacing site to achieve selective site pacing, different chamber structures where different pacing sites are located are used, and different three-dimensional bending types of the first tube segment 11 are adopted. In some embodiments, because the size of the atrium is smaller than the size of the ventricle, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, the tip of the sheath tube 1 (or the distal end of the first curved segment 111) needs to reach the right ventricle, and in this case, the bending radius of the second curved segment 112 should be large, and the three-dimensional bending type of the first tube segment 11 can be any of the above-mentioned S-type, M-type, L-type, B-type, and C-type. When the delivery sheath is used for atrial septal pacing, the tip of the sheath tube 1 (or the distal end of the first curved segment 111) must reach the right atrium. In this case, the curve radius of the second curved segment 112 should be small, and the three-dimensional bending type of the first tube segment 11 may be either Type D or Type E as described above. For a delivery sheath used for the same chamber shape (e.g., the right atrium), the three-dimensional bending type of the first tube segment 11 depends on the size of the chamber. For example, for a delivery sheath for a child's right atrium, the three-dimensional bending type of the first tube segment 11 may be Type S.

[0072] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the second curved segment 112 may have a bending radius ranging from 18 cm to 70 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the second curved segment 112 may have a bending radius ranging from 15 cm to 55 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the second curved segment 112 may have a bending radius ranging from 25 cm to 80 cm.

[0073] In some embodiments, the structural shape of the second curved segment 112 can be characterized by constructing a triangle on the second curved segment 112 and based on data related to the triangle. FIG. 3 is an exemplary schematic diagram of a first reference triangle and a second reference triangle according to some embodiments herein. As shown in FIG. 3, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the proximal end point A1, the distal end point B1, and the maximum bending point C1 of the second curved segment 112 are connected to each other to form a first reference triangle ΔA1C1B1. In the first reference triangle ΔA1C1B1, the length of the first connecting line is shorter than the length of the second connecting line, and the value of the first included angle ∠A1C1B1 at the maximum bending point C1 ranges from 80° to 120°. Here, the first connection is a connection A1C1 between the proximal end point A1 and the maximum bending point C1, and the second connection is a connection B1C1 between the distal end point B1 and the maximum bending point C1.

[0074] The center line of the second curved segment 112 forms a first curve S1, the proximal end point A1 is the proximal end point of the first curve S1, the distal end point B1 is the distal end point of the first curve S1, and the maximum bending point C1 is the point on the first curve S1 where the curvature is maximum or the point on the first curve S1 where the curvature radius is minimum.

[0075] The first included angle ∠A1C1B1 is the included angle at the maximum bending point C1 in the first reference triangle ΔA1C1B1, and can reflect the degree of curvature or radius of curvature of the second curved segment 112. For example, the smaller the angle of the first included angle ∠A1C1B1 (e.g., an acute angle), the greater the degree of curvature and radius of curvature of the second curved segment 112. Conversely, the larger the angle of the first included angle ∠A1C1B1 (e.g., an obtuse angle), the less the degree of curvature and radius of curvature of the second curved segment 112.

[0076] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the value of the first included angle ∠A1C1B1 may range from 80° to 90°. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the value of the first included angle ∠A1C1B1 may range from 110° to 120°.

[0077] In some embodiments, the area of ​​the first reference triangle ΔA1C1B1 can not only reflect the curvature and extension size of the second curved segment 112, but also intuitively reflect the size of the two-dimensional space occupied by the first reference triangle ΔA1C1B1, so that by limiting the area of ​​the first reference triangle ΔA1C1B1, the structural shape of the second curved segment 112 can adapt to different chamber structures of the heart.

[0078] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the first reference triangle ΔA1C1B1 is 20 cm 2 ~35cm 2 In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the first reference triangle ΔA1C1B1 is 17 cm 2 ~20cm 2 In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the first reference triangle ΔA1C1B1 is 35 cm 2 ~40cm 2 may be.

[0079] As can be understood, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, and C-type, by limiting the area of ​​the first reference triangle ΔA1C1B1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0080] In some embodiments, in addition to directly limiting the area of ​​the first reference triangle ΔA1C1B1, the structural shape of the second curved segment 112 can be adapted to different chamber structures of the heart by limiting the side lengths of the first reference triangle ΔA1C1B1.

[0081] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the length of the connection line A1B1 between the proximal end point A1 and the distal end point B1 may range from 6 cm to 8 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the length of the connection line A1B1 between the proximal end point A1 and the distal end point B1 may range from 5 cm to 6 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the length of the connection A1B1 between the proximal end point A1 and the distal end point B1 ranges from 8 cm to 10 cm.

[0082] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the first connection A1C1 may be in the range of 3 cm to 5 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the first connection A1C1 may be in the range of 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the first connection A1C1 may be in the range of 5 cm to 6 cm.

[0083] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending pattern of S, M, L, B, or C, the second connection wire B1C1 may have a length ranging from 7 cm to 9 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending pattern of S, M, L, B, or C, the second connection wire B1C1 may have a length ranging from 6 cm to 7 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending pattern of S, M, L, B, or C, the second connection wire B1C1 may have a length ranging from 9 cm to 10 cm.

[0084] As can be understood, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type and C-type, by limiting the side length of the first reference triangle ΔA1C1B1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0085] In some embodiments herein, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, a first reference triangle ΔA1C1B1 is constructed for the second curved segment 112, where the first included angle ∠A1C1B1 at the maximum bending point C1 can clearly characterize the degree of curvature of the second curved segment 112, and further, when combined with the area and side length of the first reference triangle ΔA1C1B1, can more intuitively represent the degree of matching between the structural shape of the second curved segment 112 and the different chamber structures of the heart. Based on this, by limiting the first included angle ∠A1C1B1 or the area or side length of the first reference triangle ΔA1C1B1, the degree of matching between the first tube segment 11 and the different chamber structures of the heart can be effectively ensured, thereby ensuring the functionality of the delivery sheath during implantation.

[0086] 3, a second reference triangle ΔA1D1B1 is formed by connecting the proximal end point A1, the distal end point B1, and the farthest bending point D1 of the second curved segment 112. In the second reference triangle ΔA1D1B1, the length of the third connecting line is shorter than the length of the fourth connecting line, and the value of the second included angle ∠A1D1B1 at the farthest bending point D1 ranges from 90° to 130°. Here, the third connecting line is a line A1D1 connecting the proximal end point A1 and the farthest bending point D1, and the fourth connecting line is a line B1D1 connecting the distal end point B1 and the farthest bending point D1.

[0087] The farthest fold point D1 is the point on the first curve that is farthest from the connecting line A1B1 between the proximal endpoint A1 and the distal endpoint B1. In some embodiments, the farthest fold point D1 is obtained by drawing a parallel line to the connecting line A1B1 and translating the parallel line to the right until it is tangent to the first curve, i.e., the tangent point of the parallel line to the first curve is the farthest fold point D1. In some embodiments, the farthest fold point D1 may or may not overlap with the maximum fold point C1.

[0088] The second included angle ∠A1D1B1 is the included angle at the farthest bending point D1 in the second reference triangle ΔA1B1D1, and can reflect the degree of protrusion of the second curved segment 112. For example, the smaller the angle of the second included angle ∠A1D1B1 (e.g., an acute angle), the higher the degree of protrusion of the second curved segment 112. The larger the angle of the second included angle ∠A1D1B1 (e.g., an obtuse angle), the lower the degree of protrusion of the second curved segment 112.

[0089] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the second included angle ∠A1D1B1 may be in the range of 50° to 60°. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the second included angle ∠A1D1B1 may be in the range of 60° to 70°.

[0090] In some embodiments, the area of ​​the second reference triangle ΔA1D1B1 can not only reflect the protrusion degree of the second curved segment 112, but also intuitively reflect the size of the two-dimensional space occupied by the second reference triangle ΔA1D1B1, so that by limiting the area of ​​the second reference triangle ΔA1D1B1, the structural shape of the second curved segment 112 can adapt to different chamber structures of the heart.

[0091] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the second reference triangle ΔA1D1B1 is 25 cm 2 ~40cm 2 In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the second reference triangle ΔA1D1B1 is 21 cm2 ~25cm 2 In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending types of the first tube segment 11 are S-type, M-type, L-type, B-type, and C-type, the area of ​​the second reference triangle ΔA1D1B1 may be 40 cm 2 ~45cm 2 may be.

[0092] As can be understood, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type and C-type, by limiting the area of ​​the second reference triangle ΔA1D1B1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0093] In some embodiments, in addition to directly limiting the area of ​​the second reference triangle ΔA1D1B1, the side lengths of the second reference triangle ΔA1D1B1 can be limited to adapt the structural shape of the second curved segment 112 to different chamber structures of the heart.

[0094] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the third connection wire A1D1 may range from 7 cm to 9 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the third connection wire A1D1 may range from 6 cm to 7 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the third connection wire A1D1 may range from 9 cm to 10 cm.

[0095] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the fourth connection B1D1 may range from 3 cm to 5 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the fourth connection B1D1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the first tube segment 11 has a three-dimensional bending type of S, M, L, B, or C, the length of the fourth connection B1D1 may range from 5 cm to 6 cm.

[0096] As can be understood, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type and C-type, by limiting the side length of the second reference triangle ΔA1B1D1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0097] In some embodiments herein, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-shaped, M-shaped, L-shaped, B-shaped, or C-shaped, the size of the space occupied by the second curved segment 112 can be more accurately represented based on the triangle formed by the farthest bending point D1, the proximal end point A1, and the distal end point B1, because the farthest bending point D1 is farther from the line A1B1 connecting the proximal end point A1 and the distal end point B1 than the maximum bending point C1. Based on this, the second included angle ∠A1D1B1 and the area or side length of the second reference triangle ΔA1D1B1 can be limited to effectively ensure the matching degree between the first tube segment 11 and the different chamber structures of the heart, thereby further ensuring the functionality of the delivery sheath during implantation.

[0098] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E-shaped three-dimensional bending, the second curved segment 112 may have a curvature radius ranging from 10 cm to 15 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E-shaped three-dimensional bending, the second curved segment 112 may have a curvature radius ranging from 8 cm to 10 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E-shaped three-dimensional bending, the second curved segment 112 may have a curvature radius ranging from 15 cm to 20 cm.

[0099] As shown in FIG. 3 , when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is Type D or Type E, the proximal end point A1, the distal end point B1, and the maximum bending point C1 of the second curved segment 112 are connected to each other to form a first reference triangle ΔA1C1B1. In the first reference triangle ΔA1C1B1, the length of the first connecting line is shorter than the length of the second connecting line, and the value of the first included angle ∠A1C1B1 at the maximum bending point C1 ranges from 70° to 100°. Here, the first connecting line is the connecting line A1C1 between the proximal end point A1 and the maximum bending point C1, and the second connecting line is the connecting line B1C1 between the distal end point B1 and the maximum bending point C1. For more details about the proximal end point, the distal end point, the maximum bending point, and the first included angle, please refer to the above related description of FIG. 3 .

[0100] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the first reference triangle ΔA1C1B1 is 8 cm 2 ~20cm 2 In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the first reference triangle ΔA1C1B1 may be 8 cm 2 ~12cm 2 In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the first reference triangle ΔA1C1B1 may be 15 cm 2 ~20cm 2 may be.

[0101] As can be understood, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, by limiting the area of ​​the first reference triangle ΔA1C1B1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0102] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the connection A1B1 between the proximal end point A1 and the distal end point B1 may range from 3 cm to 5 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the connection A1B1 between the proximal end point A1 and the distal end point B1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the connection A1B1 between the proximal end point A1 and the distal end point B1 may range from 5 cm to 6 cm.

[0103] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the first connection A1C1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the first connection A1C1 may range from 1 cm to 2 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the first connection A1C1 may range from 3 cm to 5 cm.

[0104] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the second connection B1C1 may range from 3 cm to 4 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the second connection B1C1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the second connection B1C1 may range from 4 cm to 6 cm.

[0105] As can be understood, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, by limiting the side length of the first reference triangle ΔA1C1B1 within an appropriate range, i.e., by limiting the structural shape of the second curved segment 112, it can be adapted to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0106] As shown in FIG. 3 , when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is Type D or Type E, the proximal end point A1, the distal end point B1, and the distalmost bending point D1 of the second curved segment 112 are connected to each other to form a second reference triangle ΔA1D1B1. In the second reference triangle ΔA1D1B1, the length of the third connecting line is shorter than the length of the fourth connecting line, and the second included angle ∠A1D1B1 at the distalmost bending point D1 ranges from 80° to 110°. Here, the third connecting line is the connecting line A1D1 between the proximal end point A1 and the distalmost bending point D1, and the fourth connecting line is the connecting line B1D1 between the distal end point B1 and the distalmost bending point D1. For more details about the distalmost bending point and the second included angle, please refer to the above related description of FIG. 3 .

[0107] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the second reference triangle ΔA1D1B1 is 10 cm 2 ~25cm 2 In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area range of the second reference triangle ΔA1D1B1 is 10 cm 2 ~14cm 2 In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the second reference triangle ΔA1D1B1 may be 20 cm 2 ~25cm 2 may be.

[0108] As can be understood, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the area of ​​the second reference triangle ΔA1D1B1 can be limited within an appropriate range, i.e., the structural shape of the second curved segment 112 can be limited to adapt to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0109] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the third connection A1D1 may range from 3 cm to 4 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the third connection A1D1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D or E bending type, the length of the third connection A1D1 may range from 4 cm to 6 cm.

[0110] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the fourth wire B1D1 may range from 2 cm to 3 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the fourth wire B1D1 may range from 1 cm to 2 cm. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type bending, the length of the fourth wire B1D1 may range from 3 cm to 5 cm.

[0111] As can be understood, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the side length of the second reference triangle ΔA1D1B1 can be limited within an appropriate range, i.e., the structural shape of the second curved segment 112 can be limited to adapt to different chamber structures of the heart, thereby laying the foundation for realizing selective site pacing.

[0112] As described above, the three-dimensional bending shape of the first tube segment 11 mainly depends on the degree of bending of the second curved segment 112, and therefore, the bending radius of the first curved segment 111 of the above seven bending shapes is considered to be approximately the same. Furthermore, since the first curved segment 111 is mainly used to guide the tip of the electrode lead to reach the target pacing site, the bending radius of the first curved segment 111 is relatively small.

[0113] In some embodiments, the radius of curvature of the first curved segment 111 may range from 5 cm to 8 cm. In some embodiments, the radius of curvature of the first curved segment 111 may range from 3 cm to 5 cm. In some embodiments, the radius of curvature of the first curved segment 111 may range from 8 cm to 12 cm.

[0114] As can be understood, in addition to limiting the curvature radius of the second curved segment 112, the curvature radius of the first curved segment 111 is also limited, which further ensures that the three-dimensional bending shape of the first tube segment 11 can adapt to different chamber structures of the heart, thereby allowing the tip of the electrode lead to reach the target pacing site, and further realizing selective site pacing.

[0115] Fig. 4 is a schematic structural diagram of a sheath tube structure according to some embodiments of the present disclosure. Fig. 5 is an exemplary schematic diagram of a braided layer according to some embodiments of the present disclosure. Fig. 6 is an exemplary schematic diagram of a braided layer according to some other embodiments of the present disclosure. As shown in Fig. 4, all or some of the tube segments of the sheath tube 1 include a braided layer 113, an outer layer 114, and an inner layer 115. In some embodiments, the outer layer 114, the braided layer 113, and the inner layer 115 can be formed into the sheath tube 1 by rheological compounding.

[0116] 4 to 6, the first tube segment 11 includes at least a braided layer 113, which is made of braided yarn. The braided yarn may be made of a metal wire such as a stainless steel wire.

[0117] In some embodiments, the first tube segment 11 may further include an outer layer 114 and an inner layer 115, with the braided layer 113 positioned between the outer layer 114 and the inner layer 115. The outer layer 114 is positioned outside the braided layer 113 and is the outer wall layer of the sheath tube 1 (e.g., the first tube segment 11), and the inner layer 115 is positioned inside the braided layer 113 and is the inner wall layer of the sheath tube 1 (e.g., the first tube segment 11). In some embodiments, the outer layer 114 and the inner layer 115 may be made of the same or different materials. For example, the outer layer 114 may be made of a highly flexible material such as block polyetheramide resin (Pebax) to avoid damaging the patient's blood vessels during an implantation procedure, and the inner layer 115 may be made of a highly lubricious material such as polytetrafluoroethylene (PTFE) to reduce resistance when passing a medical device such as an electrode lead through the inner layer 115 and allow the medical device to smoothly reach the target chamber.

[0118] In some embodiments, the delivery sheath may come into contact with human tissues or organs, such as blood vessels, during the implantation procedure, which may cause the first tube segment 11, particularly the second curved segment 112, to bend due to its three-dimensional bending shape, thereby causing unnecessary injury to the patient. Therefore, it is necessary to ensure the safety of the delivery sheath during the implantation procedure by improving the folding resistance of the second curved segment 112 while keeping the hardness of the second curved segment 112 within an appropriate range.

[0119] In some embodiments, the braiding method of the braided layer 113 can affect not only the hardness of the second curved segment 112 but also the folding resistance of the second curved segment 112. In some embodiments, the braiding method of the braided layer 113 is related to the shape, size, and braiding density of the braided yarn. Considering that the shape of the braided yarn is difficult to change (e.g., circular yarn), the braiding method of the braided layer 113 is primarily related to the size (e.g., diameter) and braiding density of the braided yarn. For example, the higher the braiding density, the higher the hardness, and the lower the braiding density, the lower the hardness. Also, for example, the higher the braiding density, the better the folding resistance, and the lower the braiding density, the worse the folding resistance.

[0120] 3 , when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the bending radius is smaller, the degree of bending is higher, and the second curved segment 112 is easier to bend, when the delivery sheath is used for atrial septum pacing, for example, when the three-dimensional bending type of the first tube segment 11 is D-type or E-type. Based on this, when the delivery sheath is used for atrial septum pacing, for example, when the three-dimensional bending type of the first tube segment 11 is D-type or E-type, the size (e.g., diameter) of the braided thread of the second curved segment 112 may be appropriately increased and / or the braid density may be appropriately improved.

[0121] In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the diameter range of the braided thread of the second curved segment 112 may be 0.04 mm to 0.06 mm, and the braid density range of the second curved segment 112 may be 50 to 70. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the diameter range of the braided thread of the second curved segment 112 may be 0.05 mm to 0.07 mm, and the braid density range of the second curved segment 112 may be 40 to 50. In some embodiments, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, the diameter range of the braided thread of the second curved segment 112 may be 0.03 mm to 0.05 mm, and the braid density range of the second curved segment 112 may be 70 to 80.

[0122] As can be seen, when the delivery sheath is used for ventricular septum, atrioventricular bundle branch, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, by limiting the diameter and braiding density of the braided yarn of the braided layer 113 within an appropriate range, the hardness of the second curved segment 112 can be within an appropriate range and its folding resistance can be improved to a certain extent, thereby ensuring the safety of the delivery sheath during the implantation operation.

[0123] The diameter and braid density of the braided thread of the second curved segment 112 may be set independently or in combination with the shape parameters (e.g., the curvature radius of the second curved segment 112) when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type. As can be appreciated, the diameter range and braid density range of the braided thread of the second curved segment 112 can be further limited based on the shape parameters when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type, thereby improving the folding resistance and thereby improving the safety of the delivery sheath during implantation. In some embodiments, when the shape parameters when the three-dimensional bending type of the first tube segment 11 is S-type, M-type, L-type, B-type, or C-type are different, the diameter range and braid density range of the braided thread of the second curved segment 112 may be different. For example, when the curvature radius of the second curved segment 112 is in the range of 18 cm to 35 cm, the braid density range may be 58 to 70. For example, if the radius of curvature of the second curved segment 112 is in the range of 40 cm to 70 cm, the braid density may be in the range of 50 to 55.

[0124] In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type three-dimensional bending, the diameter range of the braided thread of the second curved segment 112 may be 0.05 mm to 0.07 mm, and the braid density range of the second curved segment 112 may be 60 to 80. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the first tube segment 11 has a D-type or E-type three-dimensional bending, the diameter range of the braided thread of the second curved segment 112 may be 0.06 mm to 0.08 mm, and the braid density range of the second curved segment 112 may be 50 to 60. In some embodiments, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, the diameter range of the braided thread of the second curved segment 112 may be 0.03 mm to 0.05 mm, and the braid density range of the second curved segment 112 may be 80 to 90.

[0125] As can be seen, when the delivery sheath is used for atrial septal pacing, for example, when the three-dimensional bending type of the first tube segment 11 is type D or type E, by appropriately increasing the diameter and braiding density of the braided yarn of the braided layer 113, the hardness of the second curved segment 112 can be ensured to be within an appropriate range, while effectively improving its folding resistance, thereby ensuring the safety of the delivery sheath during clinical operation.

[0126] The diameter and braid density of the braided thread of the second curved segment 112 may be set independently or in combination with the shape parameters (e.g., the curvature radius of the second curved segment 112) when the three-dimensional bending type of the first tube segment 11 is D-type or E-type. As can be appreciated, the diameter range and braid density range of the braided thread of the second curved segment 112 can be further limited based on the shape parameters when the three-dimensional bending type of the first tube segment 11 is D-type or E-type, thereby improving the folding resistance and thereby improving the safety of the delivery sheath during implantation. In some embodiments, when the shape parameters when the three-dimensional bending type of the first tube segment 11 is D-type or E-type are different, the diameter range and braid density range of the braided thread of the second curved segment 112 can be different. For example, when the curvature radius of the second curved segment 112 is in the range of 10 cm to 12 cm, the braid density range can be 70 to 80. For example, if the radius of curvature of the second curved segment 112 is in the range of 13 cm to 15 cm, the braid density may be in the range of 60 to 70.

[0127] In some embodiments, the braiding style of the braided layer 113 may be related to the winding style of the braided thread. As described above, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-, M-, L-, B-, or C-type, the bending radius is smaller, the degree of bending is greater, and the second curved segment 112 is easier to bend. Therefore, when the delivery sheath is used for ventricular septum, atrioventricular bundle, and left bundle branch pacing, for example, when the three-dimensional bending type of the first tube segment 11 is S-, M-, L-, B-, or C-type, the second curved segment 112 can be braided as a single thread by winding two braided threads (abbreviated as single-thread braiding), as shown in FIG. 5 . When the delivery sheath is used for atrial septal pacing, for example, when the first tubing segment 11 has a three-dimensional bending type of D or E, the second curved segment 112 is made of a double-strand braid, i.e., a single strand wrapped with two braiding threads is braided separately, as shown in Figure 6. The double-strand braiding method allows for a natural transition in hardness between the different tubing segments, thereby effectively improving the folding resistance of the second curved segment 112.

[0128] In some embodiments, the second tube segment 12 and the third tube segment 13 each include at least a braided layer 113, which is made of braided yarn. In some embodiments, the second tube segment 12 and the third tube segment 13 have a structure similar to that of the first tube segment 11 and may further include an outer layer 114 and an inner layer 115. For more details about the outer layer 114 and the inner layer 115, please refer to the related description above.

[0129] In some embodiments, the hardness of each tube segment of the sheath tube 1 is related not only to the materials used for each tube segment (e.g., the materials used for the outer layer 114 and the inner layer 115) but also to the braiding method of the braided layer 113. For example, a higher braid density results in a higher hardness, and a lower braid density results in a lower hardness. In some embodiments, the hardness of the second tube segment 12 is lower than the hardness of the third tube segment 13, and therefore the braid density of the second tube segment 12 may be lower than the braid density of the third tube segment 13.

[0130] In some embodiments, the braid density of the second tube segment 12 ranges from 30 to 40, and the braid density of the third tube segment 13 ranges from 50 to 70. In some embodiments, the braid density of the second tube segment 12 ranges from 30 to 35, and the braid density of the third tube segment 13 ranges from 50 to 60. In some embodiments, the braid density of the second tube segment 12 ranges from 35 to 40, and the braid density of the third tube segment 13 ranges from 60 to 70. In some embodiments, the braid density of the second tube segment 12 ranges from 20 to 35, and the braid density of the third tube segment 13 ranges from 40 to 60. In some embodiments, the braid density of the second tube segment 12 ranges from 35 to 45, and the braid density of the third tube segment 13 ranges from 60 to 75.

[0131] In some embodiments, the correlation between the braid densities of the second tube segment 12 and the third tube segment 13 may be expressed as a range of braid density ratios. In some embodiments, the ratio of the braid density of the second tube segment 12 to the braid density of the third tube segment 13 ranges from 0.43 to 0.80. In some embodiments, the ratio of the braid density of the second tube segment 12 to the braid density of the third tube segment 13 ranges from 0.50 to 0.70. In some embodiments, the ratio of the braid density of the second tube segment 12 to the braid density of the third tube segment 13 ranges from 0.55 to 0.75. In some embodiments, the ratio of the braid density of the second tube segment 12 to the braid density of the third tube segment 13 ranges from 0.40 to 0.55. In some embodiments, the ratio of the braid density of the second tube segment 12 to the braid density of the third tube segment 13 ranges from 0.70 to 0.85.

[0132] In some embodiments of the present specification, by limiting the braid density range or the braid density ratio range of the second tube segment 12 and the third tube segment 13, the hardness of the second tube segment 12 and the third tube segment 13 can be within an appropriate hardness range, and at the same time, their folding resistance can be improved to a certain extent, thereby ensuring the pushability and safety of the delivery sheath.

[0133] Figure 7 is a schematic structural diagram of a connection point between a sheath base and a sheath tube according to some embodiments of the present disclosure. Figure 8 is a schematic structural diagram of a connection point between a sheath base and a sheath tube according to some other embodiments of the present disclosure. As shown in Figures 7 and 8, the delivery sheath further includes a sheath base 2, the sheath tube 1 further includes a cutting tube segment 14 installed at the proximal end and an implanting tube segment 15 installed at the distal end of the cutting tube segment 14, and the first tube segment 11 is located at the distal end of the implanting tube segment 15.

[0134] The implant tube segment 15 is the tube segment where the sheath tube 1 is located at the distal end of the cutting tube segment 14. In some embodiments, the implant tube segment 15 may include a first tube segment 11, a second tube segment 12, and a third tube segment 13. In some embodiments, the implant tube segment 15 may further include other tube segments. In some embodiments, the implant tube segment 15 is used to establish a passageway for a medical device, such as an electrode lead, and to guide the device to reach a target chamber.

[0135] The cutting tube segment 14 is a transition tube segment used to connect the sheath tube 1 to the sheath base 2. In some embodiments, the cutting tube segment 14 includes a connection region 141 and a buffer region 142, which are arranged in this order from proximal to distal along the axial direction of the sheath tube 1. The sheath tube 1 is connected to the sheath base 2 via the connection region 141, and the buffer region 142 is configured to provide cut resistance between the sheath base 2 and the implantable tube segment 15. In some embodiments, the axial direction of the sheath tube 1 may be represented by the X direction indicated by the arrow in FIG. 7. Proximal to distal refers to the direction from the end closest to the operator to the end farthest from the operator.

[0136] The connection region 141 is a tubing segment through which the cutting tube segment 14 connects to the sheath base 2. In some embodiments, the connection region 141 is located within the sheath base 2 (e.g., within the passageway 231 described below) and is connected to the sheath base 2 in a variety of ways. Exemplary connection methods include, but are not limited to, fastening, adhesive, etc. The buffer region 142 is a transition tubing segment located between the connection region 141 and the implantation tube segment 15. In some embodiments, the buffer region 142 is used to provide cut resistance.

[0137] As described above, after the electrodes have been fixed, the sheath tube 1 normally needs to be removed from the body. However, because another test device is provided at the other end connected to the electrode, this interferes with the removal of the sheath tube, so the sheath tube 1 needs to be cut along its axial direction to complete the removal of the entire sheath. The cutting resistance force is the resistance force encountered when an operator (e.g., a doctor) cuts the sheath tube 1 along its axial direction and removes it from the body.

[0138] In some embodiments, the cutting resistance provided by the buffer region 142 tapers from proximal to distal along the axial direction of the sheath tube 1. As can be understood, when an operator cuts the sheath tube 1 along the axial direction of the sheath tube 1, some sheath tube segments located within the sheath base 2 (e.g., the connection region 141 of the cutting tube segment 14) are blocked by the sheath base 2 and therefore require a large cutting force due to their high cutting resistance. However, other sheath tube segments located outside the sheath base 2 are no longer blocked by the sheath base 2 and require a small cutting force due to a sudden decrease in cutting resistance, thereby avoiding injury to the patient. Therefore, by gradually reducing the cutting resistance provided by the transition tube segment (e.g., the buffer region 142) located within the sheath base 2 from proximal to distal along the axial direction of the sheath tube 1, a sudden change in cutting force can be avoided, making the entire cutting process smoother, thereby reducing the difficulty of the operator's operation, reducing surgical risks, and improving the safety of the surgical process.

[0139] In some embodiments, the structure of the buffer region 142 can be designed so that the cutting resistance provided by the buffer region 142 gradually decreases from proximal to distal along the axial direction of the sheath tube 1, making the overall cutting process smoother, further reducing the difficulty of operation for the operator and the risk of surgery, and improving the safety of the surgical process.

[0140] 7, the buffering area 142 includes a first protrusion structure 1421 disposed on an inner wall of the buffering area 142. The first protrusion structure 1421 is disposed on the inner wall of the buffering area 142 to increase cut resistance. The first protrusion structure 1421 may be designed in various structural shapes, such as a rectangular parallelepiped shape. In some embodiments, the first protrusion structure 1421 and the buffering area 142 may be an integrally molded structure, or may be attached to the inner wall of the buffering area 142 by adhesive or other methods.

[0141] In some embodiments, the thickness of the first protrusion structure 1421 tapers from the proximal to the distal end along the axial direction of the sheath tube 1. Here, the thickness of the first protrusion structure 1421 refers to the wall thickness of the first protrusion structure 1421 in the radial direction of the sheath tube 1. As can be seen, because the thickness of the first protrusion structure 1421 tapers from the proximal to the distal end along the axial direction of the sheath tube 1, the cut resistance force provided by the first protrusion structure 1421 installed on the inner wall of the buffer region 142 also tapers from the proximal to the distal end along the axial direction of the sheath tube 1, thereby causing the cut resistance force provided by the buffer region 142 to taper from the proximal to the distal end along the axial direction of the sheath tube 1 and effectively avoiding a sudden change in the cut force during cutting.

[0142] In some embodiments, the first protrusion structure 1421 includes a cutting guide groove 14211, and the width of the cutting guide groove 14211 gradually decreases from the proximal end to the distal end along the axial direction of the sheath tube 1. The cutting guide groove 14211 is a groove structure, such as a V-shaped groove, formed in the first protrusion structure 1421 along the axial direction of the sheath tube 1. The width of the cutting guide groove 14211 is the width of the cutting guide groove 14211 in the circumferential direction of the sheath tube 1. In some embodiments, the cutting guide groove 14211 is formed in the center of the first protrusion structure 1421 and is used to guide the cutting direction of the cutting cutter. As can be seen, the width of the cutting guide groove 14211 gradually decreases from the proximal end to the distal end along the axial direction of the sheath tube 1, which not only guides the cutting cutter but also makes it more convenient for the operator to perform the cutting operation.

[0143] The depth of the cutting guide groove 14211 is smaller than the thickness of the first protrusion structure 1421, and ensures that the cutting force required to cut a region of the buffer region 142 where the first protrusion structure 1421 is provided is greater than the cutting force required to cut a region of the buffer region 142 where the first protrusion structure 1421 is not provided. In some embodiments, the depth of the cutting guide groove 14211 may gradually decrease from the proximal to the distal end along the axial direction of the sheath tube 1.

[0144] In some embodiments, the first protrusion structure 1421 includes multiple protrusions spaced apart along the axial direction of the sheath tube 1. As shown in FIG. 7 , each protrusion has a cutting guide groove 14211, and the thickness and / or length of the multiple protrusions gradually decrease from the proximal end to the distal end along the axial direction of the sheath tube 1. Here, the thickness of the protrusion refers to the wall thickness of the protrusion in the radial direction of the sheath tube 1, and the length of the protrusion refers to the length of the protrusion in the circumferential direction of the sheath tube 1. Note that the number of multiple protrusions is not limited and can be set according to actual needs. In some embodiments, the first protrusion structure 1421 may include only one protrusion, i.e., one protrusion is the first protrusion structure 1421.

[0145] 7 , the buffering region 142 includes a second protrusion structure 1422 attached to an inner wall of the buffering region 142, and the thickness of the second protrusion structure 1422 gradually decreases from the proximal end to the distal end along the axial direction of the sheath tube 1. The second protrusion structure 1422 is attached to an outer wall of the buffering region 142 to increase cut resistance. In some embodiments, the second protrusion structure 1422 and the buffering region 142 may be an integrally molded structure, or may be attached to the outer wall of the buffering region 1422 by adhesive or other means.

[0146] In some embodiments, the second protrusion structure 1422 may include a first protrusion 14221 and a second protrusion 14222, which are symmetrically arranged. In some embodiments, a gap is provided between the first protrusion 14221 and the second protrusion 14222 to provide frictional resistance to the cutting cutter, and the gap has a bell-mouth shape, with the width gradually decreasing from proximal to distal along the axial direction of the sheath tube 1. In some embodiments, the gap is wider near the connection region 141 and is used to guide the cutting cutter, and is narrower near the implantable tube segment 15, which can increase the cutting resistance. This structural design increases the friction and resistance between the cutting cutter and the sheath tube 1 in the buffer region 142, gradually reducing the cutting force used by the operator when cutting the buffer region 142, thereby effectively eliminating sudden changes in cutting force during the cutting process, making the entire cutting process smoother, reducing the difficulty of operation for the operator and the surgical risks, and avoiding unnecessary damage to the patient.

[0147] The buffering area 142 may have both the first protrusion structure 1421 and the second protrusion structure 1422, or may have only the first protrusion structure 1421 or only the second protrusion structure 1422. When the first protrusion structure 1421 and the second protrusion structure 1422 are both installed in the buffering area 142, the cutting guide groove 14211 of the first protrusion structure 1421 is collinear with the gap of the second protrusion structure 1422. As can be seen, both the gap and the cutting guide groove 14211 serve to guide the cutting path of the cutting cutter, so designing the gap and the cutting guide groove 14211 to be collinear eliminates the need for the operator to change the cutting path when performing a cutting operation, improving operational convenience.

[0148] It should be noted that there are various installation methods for the first protrusion structure 1421 and the second protrusion structure 1422. In some embodiments, the first protrusion structure 1421 and the second protrusion structure 1422 may be simultaneously installed on the inner wall of the buffer area 142 (for example, as shown in FIG. 7) or simultaneously installed on the outer wall of the buffer area 142 (for example, as shown in FIG. 8). In some embodiments, the first protrusion structure 1421 and the second protrusion structure 1422 may be simultaneously installed on the inner wall and outer wall of the buffer area 142, respectively.

[0149] Fig. 9 is a schematic structural diagram of a sheath base according to some embodiments of the present specification. Fig. 10 is a schematic structural diagram of a connection between a sheath base main body and a handle according to some embodiments of the present specification. As shown in Figs. 9 and 10, the sheath base 2 includes a side branch 21, a handle 22, and a sheath base main body 23. The handle 22 is connected to the sheath base main body 23. One end of the side branch 21 passes through the handle 22 and communicates with the sheath base main body 23. A valve 211 is provided at the other end of the side branch 21, and at least one joint (not shown) is connected to the valve 211.

[0150] The side branch 21 is a tubular structure in the sheath base 2 that allows communication between the sheath tube 1 and other devices or equipment. The fitting is a connecting member, including, but not limited to, a Luer fitting. In some embodiments, the fitting may be used to communicate between the side branch 21 and other devices or equipment. For example, the fitting may be connected to a suction device to facilitate the aspiration of air or the injection of an anticoagulant such as heparin. The valve 211 is a control member, including, but not limited to, a three-way valve. In some embodiments, the valve 211 can control communication between the side branch 21 and other devices or equipment and cut off communication between the side branch 21 and other devices or equipment. When the valve 211 is closed, air can be prevented from entering the blood vessel and blood can be prevented from leaking out of the body.

[0151] The handle 22 is a structure of the sheath base 2 that allows the operator to grasp the handle 22 to perform the cardiac pacemaker implantation procedure. In some embodiments, the handle 22 has a good feel and grip, helping the operator to better grasp and use the delivery sheath. In some embodiments, the handle 22 and the sheath base body 23 may be integrally molded or may be connected by welding, adhesive, or other methods.

[0152] 10 , the sheath base body 23 has a passage 231 formed along the axial direction of the sheath tube 1, one end of the side branch 21 communicates with the passage 231, and the passage 231 is configured to deliver a medical device. In some embodiments, the sheath base body 23 has a thin-wall structure 232 formed along the axial direction of the sheath tube 1, and a locking block 233 is formed on the side wall of the sheath base body 23.

[0153] The passage 231 is a passage through which the sheath base body 23 delivers a medical device (e.g., an electrode lead, etc.). In some embodiments, the connection region 141 of the sheath tube 1 is placed in the passage 231, and the medical device is introduced into the sheath tube 1 through the passage 231 and then delivered into the target chamber. In some embodiments, the size of the passage 231 may be determined depending on the size of the sheath base body 23 and the medical device.

[0154] The thin-walled structure 232 is a sidewall of a portion of the sheath base body 23. In some embodiments, the thickness of the thin-walled structure 232 tapers from the proximal to the distal end along the axial direction of the sheath tube 1, thereby gradually reducing the cutting force required when cutting the sheath base body 23 and allowing the operator to more easily cut. Here, the thickness of the thin-walled structure 232 refers to the thickness of the thin-walled structure 232 in the radial direction of the sheath tube 1.

[0155] The locking block 233 is a structure installed on the side wall of the sheath base body 23 and connects to the sheath cap. In some embodiments, the number of locking blocks 233 may be one or more. When there is one locking block 233, the locking block 233 may be peripherally installed on the side wall of the sheath base body 23. When there are multiple locking blocks 233, the locking blocks 233 may be symmetrically installed on the side wall of the sheath base body 23. In some embodiments, the locking block 233 and the sheath base body 23 may be an integrally molded structure or may be connected by adhesive, fastening, or other methods. For more details about the sheath cap, please refer to FIG. 11 and its related description.

[0156] In some embodiments, the sheath base body 23 further has a notch (not shown) along the axial direction of the sheath tube 1, the notch extending from the proximal end of the sheath base body 23 to the distal end of the sheath base body 23 and used to guide the cutting cutter. In some embodiments, the notch on the sheath base body 23, the cutting guide groove 14211 of the first protrusion structure 1421, and / or the gap of the second protrusion structure 1422 are collinear, and the cutting cutter naturally transitions from the notch to the cutting guide groove 14211 and / or the gap during cutting, improving the guiding effect for the cutting cutter.

[0157] 11 is a schematic structural diagram of a sheath cap according to some embodiments of the present disclosure. As shown in FIG. 11, the delivery sheath further includes a sheath cap 3. The sheath cap 3 has an instrument passage 31 formed along the axial direction of the sheath tube 1 and a locking groove 32 formed on a side wall of the sheath cap 3. The locking groove 32 is engaged with a locking block 233 of the sheath base body 23.

[0158] The sheath cap 3 is a structure that is fitted over the proximal end of the sheath base body 23. In some embodiments, the sheath cap 3 may be engaged with the locking block 233 of the sheath base body 23 via the locking groove 32 so that it is fitted over the proximal end of the sheath base body 23. In some embodiments, the sheath cap 3 may include a sheath cap top and an annular side wall connected to the sheath cap top, and the locking groove 32 is opened in the annular side wall. In some embodiments, the sheath cap 3 can be used to secure a hemostatic valve 4. For more details about the hemostatic valve 4, please refer to Figures 12 to 14 and their related descriptions.

[0159] The locking groove 32 is located on the side wall of the sheath cap 3 and is a structure for connecting the sheath cap 3 to the sheath base 2. In some embodiments, the locking groove 32 is located corresponding to the locking block 233 of the sheath base body 23. By locking the locking block 233 of the sheath base body 23 into the locking groove 32, the sheath cap 3 can be connected to the sheath base 2 (e.g., the sheath base body 23). The instrument passage 31 is a passage through the sheath cap 3 for passing a medical instrument (e.g., an electrode lead, etc.). In some embodiments, when the sheath cap 3 is placed over the proximal end of the sheath base body 23, the instrument passage 31 at least partially overlaps with the passage 231 of the sheath base body 23. In some embodiments, the instrument passage 31 extends radially along the sheath tube 1 on one side of the sheath cap 3, forming a notch. This notch design allows the operator to cut the sheath cap 3 without cutting the sheath cap 3 when cutting the sheath base body 23, thereby saving time and effort.

[0160] Figure 12 is a schematic structural diagram of a hemostasis valve according to some embodiments of the present disclosure. Figure 13 is a schematic structural diagram of an outlet-opening hemostasis valve according to some embodiments of the present disclosure. Figure 14 is a schematic structural diagram of an outlet-closed hemostasis valve according to some embodiments of the present disclosure. As shown in Figures 12 to 14, the delivery sheath further includes a hemostasis valve 4 installed in the passage 231 of the sheath base body 23. A circular hole structure 41 and an elastic structure 42 for passing a medical instrument through the hemostasis valve 4 are provided, and the elastic structure 42 is installed at the distal end of the circular hole structure 41 and configured to open and close the circular hole structure 41.

[0161] The hemostatic valve 4 is a structure for preventing the outflow of blood from a blood vessel. The material of the hemostatic valve 4 includes, but is not limited to, silicone rubber.

[0162] The circular hole structure 41 is a hole structure in the hemostasis valve 4 and is used to provide a passage for a medical instrument. In some embodiments, the circular hole structure 41 may include a first circular hole 411 and a second circular hole 412, where the first circular hole 411 is located at the proximal end of the hemostasis valve 4 and the second circular hole 412 is located at the distal end of the hemostasis valve 4, and the first circular hole 411 communicates with the second circular hole 412. A medical instrument (e.g., a dilator, an electrode guidewire, etc.) enters the passage 231 of the sheath base body 23 sequentially through the first circular hole 411 and the second circular hole 412, and is then introduced into the sheath tube 1. Here, the first circular hole 411 can be understood as an inlet of the hemostasis valve 4, and the second circular hole 412 can be understood as an outlet of the hemostasis valve 4, and the inner diameter of the first circular hole 411 is larger than the inner diameter of the second circular hole 412. In some embodiments, first and second holes 411, 412 are positioned eccentrically to allow for better hemostasis.

[0163] The elastic structure 42 is a sheet-like structure for opening and closing the circular hole structure 41 in the hemostatic valve 4. For example, the elastic structure 42 may include an elastic sheet. In some embodiments, the elastic structure 42 can automatically close by itself. The elastic structure 42 is located at the distal end of the circular hole structure 41 (e.g., the second circular hole 412) and opens toward the sheath tube 1. This allows the insertion of a medical instrument only toward the sheath tube 1, thereby achieving efficient hemostasis without affecting the insertion of a medical instrument such as a dilator. When a medical instrument is inserted, the elastic structure 42 opens (e.g., as shown in FIG. 13 ), and the medical instrument and the second circular hole 412 fit tightly together to achieve hemostasis. After the medical instrument is removed, the elastic structure 42 automatically closes (e.g., as shown in FIG. 14 ) by itself, achieving hemostasis. That is, regardless of whether or not a medical instrument is passed through the circular hole structure 41 (for example, the second circular hole 412), the hemostatic valve 4 can maintain a tight seal, thereby achieving the effect of stopping bleeding.

[0164] 12, the hemostatic valve 4 further includes a reinforcing rib 43 that is disposed around the outer periphery of the hemostatic valve 4 and is close to the elastic structure 42. In some embodiments, the reinforcing rib 43 can not only better assist the elastic structure 42 in automatically closing, but also better achieve hemostasis when withdrawing a medical instrument. At the same time, the reinforcing rib 43 can also prevent the elastic structure 42 from opening and allowing air into the blood vessel during clinical negative pressure suction.

[0165] The hemostasis valve 4 may be installed in the passage 231 of the sheath base body 23 in various ways. In some embodiments, the hemostasis valve 4 may be fixed in the passage 231 of the sheath base body 23 by adhesive bonding, welding, fastening, mechanical positioning, or other methods. In some embodiments, the hemostasis valve 4 may be fixed in the passage 231 of the sheath base body 23 via the sheath cap 3. As just an example, the hemostasis valve 4 has an outer edge extending along the radial direction of the sheath tube 1, the hemostasis valve 4 is positioned in the passage 231 of the sheath base body 23, the outer edge of the hemostasis valve 4 is locked between the instrument passage 31 of the sheath cap 3 and the sheath cap top, and when the locking block 233 on the sheath base body 23 is inserted into the locking groove 32 of the sheath cap 3, the hemostasis valve 4 can be fixed in the passage 231 of the sheath base body 23.

[0166] Potential beneficial effects of the embodiments herein include, but are not limited to, the following: 1) by designing the structural shape of the sheath tube (e.g., the first tube segment), a full series of delivery sheaths can be provided for pacing at different sites, solving the problem of clinical operation difficulty due to differences in the chamber sizes of patients' hearts, reducing the difficulty of operation for the operator, and solving the problem of a lack of suitable delivery sheaths in the field of atrial septal pacing; 2) by providing a protrusion structure (e.g., a first protrusion structure, a second protrusion structure) on the cutting tube segment, cutting can be made more smoothly, thereby reducing the difficulty of operation for the operator and the surgical risk, and effectively avoiding damage to the patient; and 3) by providing a hemostatic valve, air can be prevented from entering the blood vessel during clinical negative pressure suction, and the hemostatic valve can automatically close when the medical instrument is withdrawn, resulting in better and more reliable hemostasis.

[0167] The basic concepts have been described above, and it is apparent to those skilled in the art that the above detailed disclosure is merely illustrative and does not limit the present specification. Although not explicitly described herein, those skilled in the art may make various changes, improvements, and modifications to the present specification. Since such changes, improvements, and modifications are proposed herein, such changes, improvements, and modifications still fall within the spirit and scope of the exemplary embodiments of the present specification. [Explanation of symbols]

[0168] 1 sheath tube 11 First tube segment 111 First curved segment 112 Second curved segment 113 braided layer 114 Outer layer 115 Inner layer 12 Second Tube Segment 13 Third Tube Segment 14 Cut tube segments 141 Connection Area 142 Buffer area 1421 First protrusion structure 14211 Cutting guide groove 1422 Second protrusion structure 14221 1st protrusion 14222 Second protrusion 15 implantable tube segments 2 Sheath Base 21 Side Branch 211 Valve 22 Handle 23 Sheath base body 231 Passage 232 Thin wall structure 233 Locking Block 3 Sheath Cap 31 Instrument aisle 32 Locking groove 4 Hemostasis valve 41 Circular hole structure 411 1st circular hole 412 2nd round hole 42 Elastic Structure 43 Reinforcing rib

Claims

1. 1. A cardiac pacemaker electrode lead delivery sheath comprising a sheath tube, the sheath tube including at least a first tube segment disposed at a distal end thereof, the first tube segment having a first curved segment and a second curved segment, the first curved segment being located at the distal end of the first tube segment, wherein an included angle between a first bent surface of the first curved segment and a second bent surface of the second curved segment is 45° or greater.

2. 2. The cardiac pacemaker electrode lead delivery sheath of claim 1, wherein the first bending plane is perpendicular to the second bending plane.

3. 2. The cardiac pacemaker electrode lead delivery sheath of claim 1, wherein the first curved segment has a stiffness less than the stiffness of the second curved segment.

4. 4. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein the radius of curvature of the second curved segment is in the range of 18 cm to 70 cm.

5. a first reference triangle is formed by connecting the proximal end point, the distal end point and the maximum bending point of the second curved segment with each other; 5. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein, in the first reference triangle, a length of a first connection line is smaller than a length of a second connection line, a value of a first included angle at the maximum bending point ranges from 80° to 120°, the first connection line is a connection line between the proximal end point and the maximum bending point, and the second connection line is a connection line between the distal end point and the maximum bending point.

6. a second reference triangle is formed by connecting the proximal end point, the distal end point, and the farthest bending point of the second curved segment to each other; 5. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein, in the second reference triangle, a length of a third connection line is smaller than a length of a fourth connection line, a value of a second included angle at the farthest bending point ranges from 90° to 130°, the third connection line is a connection line between the proximal end point and the farthest bending point, and the fourth connection line is a connection line between the distal end point and the farthest bending point.

7. 7. The cardiac pacemaker electrode lead delivery sheath according to claim 4, wherein the first tube segment includes at least a braided layer, the braided layer being braided with a braiding thread, the diameter range of the braiding thread of the second curved segment being 0.04 mm to 0.06 mm, and the braid density range of the second curved segment being 50 to 70.

8. 4. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein the radius of curvature of the second curved segment is in the range of 10 cm to 15 cm.

9. a first reference triangle is formed by connecting the proximal end point, the distal end point and the maximum bending point of the second curved segment with each other; 9. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein in the first reference triangle, a length of a first connection line is smaller than a length of a second connection line, a value of a first included angle at the maximum bending point ranges from 80° to 120°, the first connection line is a connection line between the proximal end point and the maximum bending point, and the second connection line is a connection line between the distal end point and the maximum bending point.

10. a second reference triangle is formed by connecting the proximal end point, the distal end point, and the farthest bending point of the second curved segment to each other; 9. The cardiac pacemaker electrode lead delivery sheath according to claim 1, wherein in the second reference triangle, a length of a third connection line is smaller than a length of a fourth connection line, a value of a second included angle at the farthest bending point ranges from 90° to 130°, the third connection line is a connection line between the proximal end point and the farthest bending point, and the fourth connection line is a connection line between the distal end point and the farthest bending point.

11. 11. The cardiac pacemaker electrode lead delivery sheath according to claim 8, wherein the first tube segment includes at least a braided layer, the braided layer being braided with a braiding thread, the diameter range of the braiding thread of the second curved segment being 0.05 mm to 0.07 mm, and the braid density range of the second curved segment being 60 to 80.

12. 12. The cardiac pacemaker electrode lead delivery sheath according to claim 8 or 11, wherein the second curved segment employs a two-fold braid.

13. 13. The cardiac pacemaker electrode lead delivery sheath according to any one of claims 1 to 12, wherein the radius of curvature of the first curved segment is in the range of 5 cm to 8 cm.

14. 2. The cardiac pacemaker electrode lead delivery sheath of claim 1, wherein the sheath tube further includes a second tube segment and a third tube segment, the second tube segment being located in a central portion of the sheath tube, the third tube segment being located at a proximal end of the second tube segment, and the hardness of the second tube segment being greater than the hardness of the first tube segment and less than the hardness of the third tube segment.

15. 15. The cardiac pacemaker electrode lead delivery sheath of claim 14, wherein the second tube segment and the third tube segment each include at least a braided layer, the braided layer being braided with braiding yarn, and the braid density of the second tube segment being lower than the braid density of the third tube segment.

16. 2. The cardiac pacemaker electrode lead delivery sheath of claim 1, further comprising a sheath base, wherein the sheath tube further comprises a cutting tube segment disposed at a proximal end thereof and an implanting tube segment disposed at a distal end of the cutting tube segment, the first tube segment being located at the distal end of the implanting tube segment, the cutting tube segment including a connection region and a buffer region disposed in order from proximal to distal along the axial direction of the sheath tube, the sheath tube being connected to the sheath base via the connection region, and the buffer region being configured to provide a cut-off resistance force between the sheath base and the implanting tube segment.

17. 17. The cardiac pacemaker electrode lead delivery sheath of claim 16, wherein the cut resistance provided by the relief region tapers from proximal to distal along the axial direction of the sheath tube.

18. 18. The cardiac pacemaker electrode lead delivery sheath of claim 17, wherein the buffering region includes a first protrusion structure disposed on an inner wall of the buffering region.

19. 20. The cardiac pacemaker electrode lead delivery sheath of claim 18, wherein the thickness of the first protrusion structure tapers from proximal to distal along the axial direction of the sheath tube.

20. 20. The cardiac pacemaker electrode lead delivery sheath of claim 18, wherein the first protrusion structure includes a cutting guide groove, the width of the cutting guide groove tapering from proximal to distal along the axial direction of the sheath tube.

21. 20. The cardiac pacemaker electrode lead delivery sheath of claim 18, wherein the first projection structure comprises a plurality of projections spaced apart along the axial direction of the sheath tube.

22. 22. The cardiac pacemaker electrode lead delivery sheath according to claim 17, wherein the buffer region includes a second protrusion structure disposed on an inner wall of the buffer region, and the thickness of the second protrusion structure tapers from the proximal end to the distal end along the axial direction of the sheath tube.

23. 17. The cardiac pacemaker electrode lead delivery sheath of claim 16, wherein the sheath base includes a side branch, a handle, and a sheath base body, the handle is connected to the sheath base body, one end of the side branch passes through the handle and communicates with the sheath base body, the other end of the side branch is provided with a valve, and at least one joint is connected to the valve.

24. the sheath base body has a passage formed along an axial direction of the sheath tube, one end of the side branch communicates with the passage, and the passage is configured to deliver a medical instrument; 24. The cardiac pacemaker electrode lead delivery sheath of claim 23, wherein the sheath base body has a thin-wall structure along the axial direction of the sheath tube, and a locking block is provided on the side wall of the sheath base body.

25. 24. The cardiac pacemaker electrode lead delivery sheath of claim 23, further comprising a sheath cap, the sheath cap having an instrument passageway along the axial direction of the sheath tube, and a locking groove on a side wall of the sheath cap, the locking groove being engaged with the locking block of the sheath base body.

26. a hemostatic valve disposed within the passage of the sheath base body; 24. The cardiac pacemaker electrode lead delivery sheath of claim 23, wherein the hemostasis valve is provided with a circular hole structure and an elastic structure for passing the medical device therethrough, the elastic structure being located at a distal end of the circular hole structure and configured to open and close the circular hole structure.

27. 2. The cardiac pacemaker electrode lead delivery sheath of claim 1, wherein the material of the first curved segment includes at least a developing material.

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