Tearable structure

Abstract

The embodiment of the utility model provides a tearable structure, comprising: a braid layer, the braid layer having at least one pair of tearable areas which are arranged substantially in the longitudinal direction and are matched with each other in the circumferential direction; the tubular supporting structure extends in the longitudinal direction and is combined with the braid layer, and the supporting structure is provided with a tearable weak area which is roughly arranged in the longitudinal direction; when the tearable structure is in a non-tearable state, all pairs of tearable areas are mutually meshed in the circumferential direction; when the supporting structure is subjected to acting force exceeding a first threshold value in the tearing direction, the supporting structure is longitudinally torn from the near end to the far end of the weak area, and the mutually-meshed tearable areas are unfolded from the near end to the far end. Due to the fact that the left side and the right side of the tearable area are tightly meshed, the situation that the tearable structure is not prone to being folded or torn at the meshing combination part when resistance is encountered in the blood vessel can be well avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of medical devices, and particularly to a structure that can be torn and enter the natural cavity of a living body. Background Art

[0002] The tearable structure is a commonly used tool in the medical field, especially in interventional surgeries. This sheath tube is designed with a special feature that it can be easily torn and removed along a preset line during the surgery without causing additional damage or interference to the surrounding tissues. The natural cavities in a living body include but are not limited to blood vessels, airways, esophagus, urethra, etc.

[0003] One of the important applications of the tearable structure is in the field of cardiac pacing. Cardiac pacemaker implantation is a common surgical treatment for heart diseases, in which the tearable sheath plays a key role. During cardiac pacemaker implantation surgery, the tearable sheath is mainly used to create a channel in the heart tissue for placing the pacing electrode. It allows doctors to safely and precisely guide the electrode to a specific part of the heart. These sheath tubes are usually designed with tear lines along the length direction, so that after the electrode is inserted, the sheath tube can be easily torn along this line and removed.

[0004] Compared with the sheath tube that cannot be torn along the length direction, the advantages of the tearable structure are as follows: during cardiac pacemaker implantation surgery, once the pacemaker lead is correctly placed, the tearable structure can be easily torn along the predetermined tear line and quickly removed, reducing the surgical time and complexity. Due to the tearable structure being designed with the function of being easily torn along a specific path, the damage to the surrounding tissues during removal is small, and devices such as pacing electrodes in the blood vessel are retained. The easy-to-tear characteristic of this sheath tube improves the surgical efficiency, enabling doctors to complete the pacemaker implantation faster, thereby shortening the overall surgical time. Since the tearable structure retains the instruments that need to be indwelled in the blood vessel during removal, the trauma is small, and the discomfort and recovery time of the patient after the operation are usually reduced. In clinical operations, doctors tend to use devices that can be easily handled and removed, especially in cardiac surgeries that require precise operations.

[0005] However, due to material defects, the tearable structure in the prior art has poor supporting force and cannot be arbitrarily three-dimensionally shaped. Since there is a lack of a strengthening structure at the weak part that can be torn, the sheath tube is prone to folding when passing through a curved angle. The strength and durability of the tearable sheath tube are inferior to those of traditional sheath tubes. The strength and durability of existing sheath tubes may not meet the requirements of some special medical procedures, such as procedures that need to be operated in a narrow space. During the pushing process, the strength of the sheath tube will significantly decrease, which may cause the sheath tube to deform or tear.

[0006] In Chinese Patent CN112533661A, a reinforcing layer is added to the tearable sheath. However, the discontinuous part of the reinforcing layer is still relatively weak and is still prone to deformation or tearing during the pushing process of the sheath tube.

[0007] Therefore, there is an urgent need for a tearable structure that has sufficient strength, meets plasticity, improves surgical efficiency, and ensures safety. Summary of the Invention

[0008] In view of the above problems, the present application provides a tearable structure to overcome the above problems or at least partially solve the above problems.

[0009] An embodiment of the present application provides a tearable structure. The tearable structure includes: a braided layer having at least a pair of tearable regions arranged substantially longitudinally and matching each other circumferentially; a tubular support structure extending longitudinally and combined with the braided layer, and the support structure having a tearable weak region arranged substantially longitudinally; in the non-torn state of the tearable structure, each pair of the tearable regions bite each other circumferentially; when a force in the tearing direction exceeding a first threshold is applied, the support structure tears longitudinally from the proximal end to the distal end of the weak region, and the mutually biting tearable regions unfold from the proximal end to the distal end, that is, the mutually biting tearable regions are sequentially separated circumferentially from the proximal end to the distal end.

[0010] Optionally, the braided layer has two pairs of tearable regions distributed longitudinally, the support structure has two weak regions matching the two pairs of tearable regions, and each of the weak regions corresponds to each of the tearable regions respectively.

[0011] Optionally, one pair of the tearable regions is mirror-symmetrically arranged relative to the axis of the tearable structure with respect to the other pair of the tearable regions, and the projection regions of each of the tearable regions and each of the weak regions along the radial direction substantially overlap.

[0012] Optionally, one pair of the tearable regions is asymmetrically arranged relative to the axis of the tearable structure with respect to the other pair of the tearable regions, and the projection regions of each of the tearable regions and each of the weak regions along the radial direction substantially overlap.

[0013] Optionally, each pair of tearable regions includes a first braided area and a second braided area arranged oppositely circumferentially. The first braided area and the second braided area respectively form several inflection points and openings formed by adjacent inflection points. When the tearable regions bite each other circumferentially, the inflection points of the first braided area are inserted into the openings of the second braided area, the inflection points of the second braided area are inserted into the openings of the first braided area, and the weak region includes a V-shaped groove extending longitudinally along the outer periphery of the support structure.

[0014] Optionally, each of the tearable regions is formed by at least one wire woven in a serpentine pattern longitudinally.

[0015] Optionally, the support structure includes a polymer layer, and the woven layer is embedded in the polymer layer.

[0016] Optionally, the polymer layer includes an inner liner tube and an outer jacket tube, and the woven layer is disposed between the inner liner tube and the outer jacket tube and is fused with the inner liner tube and the outer jacket tube.

[0017] Optionally, the tearable structure further includes: a tear valve having a first valve body and a second valve body, wherein the first valve body and the second valve body are respectively connected to at least one of the support structure and the woven layer; when the first valve body and the second valve body move away from each other, the first valve body and the second valve body respectively drive the support structure to tear along the weak region, and the mutually engaged tearable regions are unfolded from the proximal end to the distal end.

[0018] As can be seen from the above technical solutions, in the woven layer of the tearable structure in the embodiments of the present application, there are tearable regions that can be mutually engaged in the circumferential direction. Since the engagement on the left and right sides is tight, it is possible to better avoid deformation or kinking when encountering resistance in the blood vessel. Ordinary tearable structures are prone to rupture or kinking during the tearing process because gaps are formed, while the tearable structure of the present application can form tearable regions at any position without having to consider setting two pairs of oppositely arranged tearable regions on the tearable structure to avoid rupture of the tear sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the embodiments of the present application, and those of ordinary skill in the art can also obtain other drawings based on these drawings.

[0020] Figure 1A-1B They are cross-sectional views of two embodiments of a tearable structure of the present application respectively;

[0021] Figure 2A-2B They are respectively a perspective view and a side view of a first embodiment of the woven layer of a tearable structure of the present application;

[0022] Figure 3A-3B They are respectively a perspective view and a side view of a second embodiment of the woven layer of a tearable structure of the present application;

[0023] Figure 4A-4B They are respectively a perspective view and a side view of another embodiment of a tearable structure of the present application;

[0024] Figure 5 This is a schematic diagram of an embodiment of a tear valve with a tearable structure in the present application.

[0025] Element reference numerals

[0026] 101: Braided layer; 102: Support structure; 103: Weak area; 1031: Tearable area; 105: Groove; 117: First braided area; 118: Second braided area; 119: Inflection point; 120: Opening; 121: First valve body; 122: Second valve body; 130: Polymer layer. Detailed implementation manners

[0027] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the embodiments of the present application.

[0028] The following further illustrates the specific implementation of the embodiments of the present application in conjunction with the accompanying drawings of the embodiments of the present application.

[0029] See Figures 1A to 5 , in a specific implementation of the present application, a tearable structure is provided. The tearable structure includes a braided layer 101, and the braided layer 101 has at least a pair of tearable areas 1031 that are arranged substantially longitudinally and are circumferentially matched with each other; a tubular support structure 102, the support structure 102 extends longitudinally and is combined with the braided layer 101, and the support structure 102 has a tearable weak area 103 that is arranged substantially longitudinally; in the non-torn state of the tearable structure, the tearable areas 1031 that are circumferentially matched with each other are circumferentially engaged with each other; when a force in the tear direction exceeding a threshold value is applied, the support structure 102 is longitudinally torn from the proximal end to the distal end of the weak area 103, and the engaged tearable areas 1031 are unfolded from the proximal end to the distal end. The "proximal end" refers to the end close to the applied force in the tear direction, and the "distal end" refers to the end far from the applied force in the tear direction.

[0030] The braided layer 101 can enhance the strength and durability of the tearable structure, while the setting of the tearable area 1031 can meet the surgical requirements, making it easier to perform surgical operations when encountering twists and turns in the blood vessel. If the tearable sheath of Chinese patent CN112533661A can be torn when subjected to a force in the tearing direction exceeding the second threshold, then the first threshold is greater than the second threshold, indicating that the tearable structure of the embodiment of the present application has a higher strength, thereby overcoming the characteristics of the existing tearable structure that is easy to bend and has poor pushing performance, and can better adapt to various curved vascular access conditions.

[0031] The braided layer 101 may include metal wires that cross or partially overlap each other, or may include metal wires that do not cross or overlap each other. The material of the metal wires may be nickel-titanium alloy, stainless steel, cobalt-chromium alloy, etc.

[0032] The support structure 102 may be made of a polymer, and may include: an inner lining layer, which forms the inner side of the tearable structure; an outer jacket layer, and the braided layer 101 is embedded in the outer jacket layer or in a polymer layer formed by integrating the inner lining layer and the outer jacket layer. The inner lining layer, the outer jacket layer and the braided layer 101 may be integrated by a hot melt process. As can be seen from FIG1 , after the support structure 102 and the braided layer 101 are integrated, the braided layer 101 is coated therein by the support structure 102. It is also possible to coat the polymer material only on the surface of the braided layer 101.

[0033] like Figures 1A-4B As shown, the braided layer 101 has two pairs of tearable areas 1031 arranged roughly in the longitudinal direction and matched with each other in the circumferential direction, and the support structure 102 has two weak areas 103, each pair of tearable areas 1031 corresponds to one weak area 103, and the radial projection areas of each pair of tearable areas 1031 and each weak area 103 roughly overlap, for example, the longitudinal projection lines of each tearable area 1031 and each weak area 103 are on the same plane as the axis of the braided layer 101. When torn by external force, the tearable areas 1031 and the weak areas 103 will be damaged first.

[0034] In one embodiment, if Figure 1A-1B As shown, one pair of tearable areas is asymmetrically arranged with respect to the axis of the tearable structure and the other pair of tearable areas, and the projection areas of each tearable area and each weak area along the radial direction substantially overlap.

[0035] In one embodiment, if Figure 2A-2B As shown, one pair of tearable areas is arranged in a mirror image with respect to the axis of the tearable structure and the other pair of tearable areas, and the projection areas of each tearable area and each weak area along the radial direction substantially overlap. Compared with the two adjacent pairs of tearable areas arranged in a mirror image, the two adjacent pairs of tearable areas arranged asymmetrically are closer along the circumferential surface.

[0036] As shown Figures 1A-4B in FIG. 1, in one embodiment, the braided layer 101 includes a first braided region 117 and a second braided region 118 that are serpentinely braided longitudinally, wherein the serpentine braiding forms a plurality of inflection points 119 distributed longitudinally, and an opening 120 is formed between two adjacent inflection points 119. When two tearable regions 1031 are engaged with each other circumferentially, the inflection points of the first braided region 117 are inserted into the openings of the second braided region 118, and the inflection points of the second braided region 118 are inserted into the openings of the first braided region 117. There are weak regions 103 and non-weak regions 104 distributed axially on the support structure 102. In a cross-section perpendicular to the axis line, the weak regions 103 and the non-weak regions 104 are alternately distributed, and the arc length of each weak region 103 accounts for 1 / 360 - 30 / 360 of the entire circumferential perimeter. The weak region 103 includes a V-shaped groove 105 extending axially. The first braided region 117 and the second braided region 118 can form two semi-circular structures or an asymmetric structure, and the braided layer 101 is heat-melted between the inner liner tube and the outer sleeve polymer material. The first braided region 117 and the second braided region 118 are not used to limit the braided layer 101 to only include two braided regions, and there can also be more braided regions and corresponding more tearable regions.

[0037] As shown Figures 1A-4B in FIG. 2, in one embodiment, the braided layer 101 includes a first braided region 117 and a second braided region 118 that are serpentinely braided longitudinally, wherein the serpentine braiding forms a plurality of inflection points 119 distributed longitudinally, and an opening 120 is formed between two adjacent inflection points 119. When two tearable regions 1031 are engaged with each other circumferentially, the inflection points of the first braided region 117 are inserted into the openings of the second braided region 118, and the inflection points of the second braided region 118 are inserted into the openings of the first braided region 117. There are weak regions 103 and non-weak regions 104 distributed axially on the support structure 102. In a cross-section perpendicular to the axis line, the weak regions 103 and the non-weak regions 104 are alternately distributed, and the arc length of each weak region 103 accounts for 1 / 360 - 30 / 360 of the entire circumferential perimeter. The materials of the weak region 103 and the non-weak region 104 are different. Among them, the tearing strength of the material of the non-weak region 104 is 1.1 - 100 times that of the material of the weak region 103. The first braided region 117 and the second braided region 118 can form two semi-circular structures or an asymmetric structure, and the braided layer 101 is heat-melted in the support structure 102. The first braided region 117 and the second braided region 118 are not used to limit the braided layer 101 to only include two braided regions, and there can also be more braided regions and corresponding more tearable regions.

[0038] As shown Figures 1A-4BAs shown, the inflection point 119 of the second braided region 118 and the opening 120 of the first braided region 117 are circumferentially opposite to each other. The first braided region 117 and the second braided region 118 each include a single wire.

[0039] In the above two embodiments, the first braided region 117 and the second braided region 118 are arranged in a lapped and staggered manner. The advantage of this structure is that the two parts bite like a zipper, resulting in better pushing ability of the tearable structure and better shape retention ability at the same time. The braiding methods of the first braided region 117 and the second braided region 118 are not limited to the above embodiments and can also be any other braiding methods.

[0040] In one embodiment, the support structure includes a polymer layer, and the braided layer is embedded in the polymer layer. During production, the tubular braided layer 101 can be transferred to the inner liner tube, and the inner liner tube, the outer sleeve tube, and the braided layer 101 are melted together by heat reflow to form a complete polymer braided tube. In the design of the outer sleeve tube, a V-shaped groove 105 can be designed during extrusion molding. Before the start of heat reflow, ensure that the V-shaped groove 105 of the outer sleeve tube coincides with the weak area 103 of the braided layer 101. When tearing the polymer braided tube, the V-shaped groove 105 can play a guiding role.

[0041] As Figure 5 shown, the tearable structure may further include: a tear valve that can prevent blood backflow. The tear valve has a first valve body 121 and a second valve body 122; the first valve body 121 and the second valve body 122 are respectively connected to at least one of the support structure 102 and the braided layer 101. When the first valve body 121 and the second valve body 122 move away from each other, the first valve body 121 and the second valve body 122 respectively drive the support structure 102 to tear along the weak area 103, and the tearable areas 1031 that bite each other unfold from the proximal end to the distal end.

[0042] In summary, in the embodiments of the present application, tearable areas that can bite each other circumferentially are provided in the braided layer of the tearable structure. Since the left and right sides bite tightly, it is possible to better avoid deformation or folding when encountering resistance in the blood vessel. Ordinary tearable structures are prone to rupture or folding during the tearing process because gaps are formed, while the tearable structure of the present application can form tearable areas at any position without the need to consider setting two pairs of oppositely arranged tearable areas on the tearable structure to avoid rupture of the tear sheath.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A tearable structure, characterized in that, The tearable structure includes: a woven layer having at least a pair of tearable regions arranged substantially longitudinally and mating with each other circumferentially; a tubular support structure extending longitudinally and combined with the woven layer, and the support structure having a tearable weak region arranged substantially longitudinally; In the non-torn state of the tearable structure, each pair of the tearable regions engages with each other circumferentially; when a force in the tearing direction exceeding a first threshold is applied, the support structure tears longitudinally from the proximal end to the distal end of the weak region, and the engaged tearable regions unfold from the proximal end to the distal end.

2. The tearable structure according to claim 1, wherein The woven layer has two pairs of tearable regions distributed longitudinally, the support structure has two weak regions matching the two pairs of tearable regions, and each of the weak regions corresponds to each of the tearable regions respectively.

3. The tearable structure according to claim 2, wherein One pair of the tearable regions is mirror-symmetrically arranged relative to the axis of the tearable structure with respect to the other pair of the tearable regions, and the projection regions of each of the tearable regions and each of the weak regions in the radial direction substantially overlap.

4. The tearable structure according to claim 2, characterized in that, One pair of the tearable regions is asymmetrically arranged relative to the axis of the tearable structure with respect to the other pair of the tearable regions, and the projection regions of each of the tearable regions and each of the weak regions in the radial direction substantially overlap.

5. The tearable structure according to claim 3 or 4, characterized in that, Each pair of tearable regions includes a first woven area and a second woven area arranged oppositely circumferentially, the first woven area and the second woven area respectively form several inflection points and openings formed by adjacent inflection points, and when the tearable regions engage with each other circumferentially, the inflection points of the first woven area are inserted into the openings of the second woven area, the inflection points of the second woven area are inserted into the openings of the first woven area, and the weak region includes a V-shaped groove extending longitudinally along the outer periphery of the support structure.

6. The tearable structure according to claim 5, wherein, Each of the tearable regions is formed by at least one wire woven in a serpentine shape longitudinally.

7. The tearable structure according to claim 1, wherein The support structure includes a polymer layer, and the woven layer is embedded in the polymer layer.

8. The tearable structure according to claim 7, wherein The polymer layer includes an inner liner tube and an outer sleeve tube, and the woven layer is arranged between the inner liner tube and the outer sleeve tube and fused with the inner liner tube and the outer sleeve tube.

9. The tearable structure according to claim 1, wherein The tearable structure further includes: a tear valve having a first valve body and a second valve body, the first valve body and the second valve body are respectively connected to at least one of the support structure and the woven layer; when the first valve body and the second valve body move away from each other, the first valve body and the second valve body respectively drive the support structure to tear along the weak region, and the engaged tearable regions unfold from the proximal end to the distal end.

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