Tearable structure

Abstract

Provided in the embodiments of the present application is a tearable structure, comprising: a weaving layer, provided with at least one pair of tearable regions that are arranged substantially in a longitudinal direction and match each other in a circumferential direction; a tubular support structure, extending in the longitudinal direction and being combined with the weaving layer and provided with a tearable thinner region arranged substantially in the longitudinal direction. When the tearable structure is in an untorn state, each pair of the tearable regions are engaged with each other in the circumferential direction. When subjected to an acting force in a tearing direction exceeding a first threshold, the support structure is longitudinally torn from a proximal end to a distal end of the thinner region, and the mutually engaged tearable regions are separated from the proximal end to the distal end. Since the left and right sides of the tearable regions are tightly engaged, the tearable structure can be better prevented from being easily folded or torn at the engagement joint when resistance is encountered in the blood vessel.

Description

Tearable structure TECHNICAL FIELD

[0001] The embodiments of the present application relate to the technical field of medical devices, in particular to a structure that can tear into the natural cavity of a living body. BACKGROUND

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

[0003] The application of tearable structure in the field of cardiac pacing is one of its important uses. Cardiac pacemaker implantation is a common treatment for heart disease, and the tearable sheath plays a key role in it. In the cardiac pacemaker implantation surgery, the tearable sheath is mainly used to create a channel in the heart tissue for the placement of pacing electrodes. It allows the doctor to safely and accurately guide the electrode to a specific part of the heart. These sheaths are usually designed with a tear line along the length, so that after the electrode is placed, the sheath can be easily torn and removed along this line.

[0004] Compared with sheaths that cannot be torn along the length, the advantages of tearable structure are: in the cardiac pacemaker implantation surgery, once the pacemaker lead is correctly placed, the tearable structure can be easily torn and quickly removed along the predetermined tear line, reducing the operation time and complexity. Since the tearable structure is designed to be easily torn along a specific path, they cause less damage to the surrounding tissues when removed, leaving the blood vessels such as pacing electrodes. The easy-to-tear feature of this sheath improves surgical efficiency, allowing doctors to complete pacemaker implantation more quickly, thereby shortening the overall operation time. Since the tearable structure causes less trauma when removed, the patient's discomfort and recovery time after surgery are usually reduced. In clinical practice, doctors prefer to use devices that can be easily handled and removed, especially in heart surgery where precise operation is required.

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

[0006] The Chinese patent CN112533661A adds a reinforcing layer in the tearable sheath, but the discontinuity of the reinforcing layer is still relatively weak, and it is still easy to deform or tear during the pushing process of the sheath.

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

[0008] SUMMARY

[0009] 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.

[0010] The present application provides a tearable structure, which comprises: a woven layer having at least one pair of tearable regions arranged substantially along the longitudinal direction and matched with each other in the circumferential direction; and a tubular support structure combined with the woven layer along the longitudinal direction, the support structure having a weak region arranged substantially along the longitudinal direction, the tearable structure being in an unteared state, each pair of the tearable regions being engaged with each other in the circumferential direction, when subjected to a force along the tearing direction exceeding a first threshold value, the support structure tears longitudinally from the proximal end to the distal end of the weak region, and the mutually engaged tearable regions unfold from the proximal end to the distal end, i.e., the mutually engaged tearable regions are sequentially separated in the circumferential direction from the proximal end to the distal end.

[0011] Optionally, the woven layer has two pairs of tearable regions distributed along the longitudinal direction, the support structure has two weak regions matched with the two pairs of tearable regions, and each weak region corresponds to each tearable region.

[0012] Optionally, one pair of the tearable regions is arranged in mirror image relative to the other pair of the tearable regions relative to the axial center line of the tearable structure, and the projection area of each tearable region and each weak region along the radial direction substantially overlaps.

[0013] Optionally, one pair of the tearable regions is arranged asymmetrically relative to the other pair of the tearable regions relative to the axial center line of the tearable structure, and the projection area of each tearable region and each weak region along the radial direction substantially overlaps.

[0014] Optionally, each pair of tearable regions comprises a first woven area and a second woven area arranged opposite in the circumferential direction, the first woven area and the second woven area respectively form a plurality of inflection points and openings formed by adjacent inflection points, and when the tearable regions are engaged with each other in the circumferential direction, 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 comprises a V-shaped groove extending longitudinally along the outer periphery of the support structure.

[0015] Optionally, each of the tearable regions is formed by at least one wire being longitudinally and serpentine woven.

[0016] Optionally, the support structure comprises a polymer layer, and the woven layer is embedded in the polymer layer.

[0017] Optionally, the polymer layer comprises an inner tube and an outer tube, and the woven layer is disposed between and fused with the inner tube and the outer tube.

[0018] Optionally, the tearable structure further comprises a tear valve having a first valve body and a second valve body, the first valve body and the second valve body being connected with at least one of the support structure and the woven layer respectively; when the first valve body and the second valve body are away from each other, the first valve body and the second valve body drive the support structure to tear along the weak region, and the mutually engaging tearable regions expand from the proximal end to the distal end.

[0019] As can be seen from the above technical solutions, the embodiment of the present application provides the woven layer of the tearable structure with the tearable regions that can engage with each other in the circumferential direction. Since the left and right sides are tightly engaged, deformation or folding can be better avoided when resistance is encountered in the blood vessel. The ordinary tearable structure is prone to rupture or folding during the tearing process due to the formation of the gap. The tearable structure of the present application can form the tearable regions at any position, and it is not necessary to consider that two pairs of oppositely arranged tearable regions must be provided on the tearable structure in order to avoid rupture of the tearable sheath. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0021] FIGS. 1A-1B are cross-sectional views of two embodiments of a tearable structure according to the present application;

[0022] FIGS. 2A-2B are a perspective view and a side view of a first embodiment of a woven layer of a tearable structure according to the present application;

[0023] FIGS. 3A-3B are a perspective view and a side view of a second embodiment of a woven layer of a tearable structure according to the present application;

[0024] FIGS. 4A-4B are a perspective view and a side view of another embodiment of a tearable structure according to the present application;

[0025] FIG. 5 is a schematic diagram of an embodiment of a tearable valve of a tearable structure according to the present application.

[0026] Element Reference

[0027] 101: woven layer; 102: support structure; 103: weak area; 1031: tearable area; 105: groove; 117: first woven area; 118: second woven area; 119: inflection point; 120: opening; 121: first valve body; 122: second valve body; 130: polymer layer. Specific Embodiment

[0028] In order 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 combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art should be within the scope of protection of the embodiments of the present application.

[0029] The specific implementation of the embodiments of the present application will be further described below in combination with the drawings of the embodiments of the present application.

[0030] Referring to FIGS. 1A-5, in a specific implementation of the present application, a tearable structure is provided, which includes a woven layer 101 having at least one pair of tearable areas 1031 arranged substantially along the longitudinal direction and matching each other in the circumferential direction; a tubular support structure 102 combined with the woven layer 101 along the longitudinal direction, the support structure 102 having a weak area 103 arranged substantially along the longitudinal direction and being tearable; and the tearable areas 1031 matching each other in the circumferential direction are engaged with each other in the circumferential direction in the unteared state of the tearable structure; when subjected to a force along the tearing direction exceeding a threshold value, the support structure 102 is torn longitudinally 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 along the tearing direction, and the "distal end" refers to the end away from the applied force along the tearing direction.

[0031] The woven layer 101 can enhance the strength and durability of the tearable structure, while the provision of the tearable areas 1031 can meet the requirements of surgery and facilitate surgical operation 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 along the tearing direction exceeding a second threshold value, the first threshold value is greater than the second threshold value, which indicates that the strength of the tearable structure of the present application is higher, thereby overcoming the characteristics of the existing tearable structure that is easy to fold and has poor push performance, and better adapting to various curved blood vessel access conditions.

[0032] The braided layer 101 can include metal wires crossing each other or partially overlapping, or can include metal wires without crossing or overlapping relationship. The metal wires can be made of nickel-titanium alloy, stainless steel, cobalt-chromium alloy, etc.

[0033] The support structure 102 can be made of polymer, and can include an inner liner layer forming the inner side of the tearable structure, and an outer cover layer in which the braided layer 101 is embedded or the polymer layer fused with the inner liner layer and the outer cover layer. The inner liner layer, the outer cover layer and the braided layer 101 can be fused by a hot melt process. As shown in FIG. 1, after the support structure 102 is fused with the braided layer 101, the braided layer 101 is covered in the support structure 102. Alternatively, the polymer material can be coated only on the surface of the braided layer 101.

[0034] As shown in FIGS. 1A-4B, the braided layer 101 has two pairs of tearable regions 1031 arranged along the longitudinal direction and matching each other in the circumferential direction, and the support structure 102 has two weak regions 103, each pair of tearable regions 1031 corresponding to one weak region 103, and each pair of tearable regions 1031 and each weak region 103 substantially overlap in the radial direction, for example, the projection lines of each tearable region 1031 and each weak region 103 along the longitudinal direction are in the same plane as the axis of the braided layer 101. When torn by external force, the tearable regions 1031 and the weak regions 103 will be damaged first.

[0035] In an embodiment, as shown in FIGS. 1A-1B, one pair of tearable regions is asymmetrically arranged relative to the other pair of tearable regions with respect to the axis of the tearable structure, and each tearable region and each weak region substantially overlap in the radial direction.

[0036] In an embodiment, as shown in FIGS. 2A-2B, one pair of tearable regions is mirror-symmetrically arranged relative to the other pair of tearable regions with respect to the axis of the tearable structure, and each tearable region and each weak region substantially overlap in the radial direction. With respect to the mirror-symmetrically arranged adjacent two pairs of tearable regions, the asymmetrically arranged adjacent two pairs of tearable regions are closer to each other in the circumferential surface.

[0037] As shown in FIGS. 1A-4B, in an embodiment, the braided layer 101 includes a first braided zone 117 and a second braided zone 118 which are braided along a longitudinal direction, wherein the braiding forms a plurality of inflection points 119 distributed along the longitudinal direction, and an opening 120 is formed between two adjacent inflection points 119, when the two tearable regions 1031 are engaged with each other along a circumferential direction, the inflection points of the first braided zone 117 are inserted into the openings of the second braided zone 118, and the inflection points of the second braided zone 118 are inserted into the openings of the first braided zone 117, and there are weak regions 103 and non-weak regions 104 distributed along an axial direction on the support structure 102. In a cross section perpendicular to the axial center 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 length. The weak regions 103 include V-shaped grooves 105 extending along the axial direction. The first braided zone 117 and the second braided zone 118 can form two half-circular structures or asymmetric structures, and the braided layer 101 is heat-fused between the inner liner tube and the outer sleeve tube high polymer material. The first braided zone 117 and the second braided zone 118 are not used to limit that the braided layer 101 includes only two braided zones, but can also include more braided zones and corresponding more tearable regions.

[0038] As shown in FIGS. 1A-4B, in an embodiment, the braided layer 101 includes a first braided zone 117 and a second braided zone 118 which are braided along a longitudinal direction, wherein the braiding forms a plurality of inflection points 119 distributed along the longitudinal direction, and an opening 120 is formed between two adjacent inflection points 119, when the two tearable regions 1031 are engaged with each other along a circumferential direction, the inflection points of the first braided zone 117 are inserted into the openings of the second braided zone 118, and the inflection points of the second braided zone 118 are inserted into the openings of the first braided zone 117. There are weak regions 103 and non-weak regions 104 distributed along an axial direction on the support structure 102. In a cross section perpendicular to the axial center 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 length. The weak regions 103 and the non-weak regions 104 are made of different materials, wherein the tear strength of the material of the non-weak regions 104 is 1.1-100 times the tear strength of the material of the weak regions 103. The first braided zone 117 and the second braided zone 118 can form two half-circular structures or asymmetric structures, and the braided layer 101 is heat-fused in the support structure 102. The first braided zone 117 and the second braided zone 118 are not used to limit that the braided layer 101 includes only two braided zones, but can also include more braided zones and corresponding more tearable regions.

[0039] As shown in FIGS. 1A-4B, the inflection points 119 of the second braided zone 118 and the openings 120 of the first braided zone 117 are oppositely arranged along a circumferential direction. The first braided zone 117 and the second braided zone 118 each include a single wire material.

[0040] The first braided area 117 and the second braided area 118 of the above two embodiments are in a lap joint staggered distribution, and the advantage of this structure is that the two parts are engaged like a zipper, so that the pushability of the tearable structure is better, and at the same time, the shape retention ability is better. The braiding method of the first braided area 117 and the second braided area 118 is not limited to the above embodiments, and can also be any other braiding method.

[0041] In an embodiment, the support structure includes a polymer layer, and the braided layer is embedded in the polymer layer. When manufacturing, 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, the V-shaped groove 105 of the outer sleeve tube is ensured to coincide with the weak area 103 of the braided layer 101, and the V-shaped groove 105 can play a guiding role when the polymer braided tube is torn.

[0042] As shown in FIG. 5, the tearable structure can further include a tear valve that can prevent blood from flowing backward, and 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 with at least one of the support structure 102 and the braided layer 101, and when the first valve body 121 and the second valve body 122 are away from each other, the first valve body 121 and the second valve body 122 drive the support structure 102 to tear along the weak area 103, and the mutually engageable tearable area 1031 expands from the proximal end to the distal end.

[0043] In summary, the embodiments of the present application provide a braided layer in the tearable structure, which has a tearable area that can be engaged in the circumferential direction. Since the left and right sides are tightly engaged, deformation or folding can be better avoided when encountering resistance in the blood vessel. Ordinary tearable structures are prone to breakage or folding during the tearing process due to the formation of gaps, while the tearable structure of the present application can form a tearable area at any position, without the need to consider that two pairs of oppositely arranged tearable areas must be provided on the tearable structure to avoid breaking the tearable sheath.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A tearable structure, characterized by, The tearable structure comprises: a woven layer having at least one pair of tearable regions arranged substantially along a longitudinal direction and matching each other in a circumferential direction; a tubular support structure combined with the woven layer along the longitudinal direction, and having a weak region arranged substantially along the longitudinal direction; in an unteared state, each pair of the tearable regions engages each other in the circumferential direction; when subjected to a force along a tearing direction exceeding a first threshold, the support structure tears longitudinally from a proximal end to a distal end of the weak region, and the engaged tearable regions unfold from the proximal end to the distal end.

2. The tearable structure of claim 1, wherein, The woven layer has two pairs of tearable regions distributed along the longitudinal direction, and 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.

3. The tearable structure of claim 2, wherein, One of the pairs of tearable regions is arranged in a mirror image relative to the other pair of tearable regions with respect to an axial center line of the tearable structure, and each of the tearable regions substantially overlaps with each of the weak regions in a radial direction.

4. The tearable structure of claim 2, wherein, One of the pairs of tearable regions is arranged asymmetrically relative to the other pair of tearable regions with respect to an axial center line of the tearable structure, and each of the tearable regions substantially overlaps with each of the weak regions in a radial direction.

5. A tearable structure according to claim 3 or 4, characterised in that, Each pair of tearable regions comprises a first woven area and a second woven area arranged opposite to each other in the circumferential direction, the first woven area and the second woven area form a plurality of inflection points and openings formed by adjacent inflection points, respectively, and when the tearable regions engage each other in the circumferential direction, the inflection points of the first woven area are inserted into the openings of the second woven area, and the inflection points of the second woven area are inserted into the openings of the first woven area, and the weak region comprises a V-shaped groove extending longitudinally along an outer periphery of the support structure.

6. The tearable structure of claim 5, wherein, Each of the tearable regions is formed by weaving at least one wire in a serpentine manner along the longitudinal direction.

7. The tearable structure of claim 1, wherein, The support structure comprises a polymer layer, and the woven layer is embedded in the polymer layer.

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

9. The tearable structure of claim 1, wherein, The tearable structure further comprises a tear valve having a first valve body and a second valve body connected with at least one of the support structure and the woven layer, respectively; when the first valve body and the second valve body move away from each other, the first valve body and the second valve body 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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