Shapeable catheter

Abstract

The present application provides a shapeable catheter (10) comprising a first stiffness layer (50) and a second stiffness layer (60) defining an annular lumen (70) for receiving a liquid, the first stiffness layer being made of an elastic material having a first stiffness, the second stiffness layer being made of a material having a second stiffness, the second stiffness being greater than said first stiffness, and a support layer arranged adjacent to the first stiffness layer, the support layer having a recess on a surface facing the first stiffness layer, the shapeable catheter (10) having a shaped state and an unshaped state and changing between the two states in response to a liquid pressure within the annular lumen (70), in the shaped state the first stiffness layer (50) assumes a deformed state partially embedded within the recess of said support layer mechanically interlocking the first stiffness layer with the support layer together, in the unshaped state the first stiffness layer assumes an undeformed state allowing a relative displacement between said support layer.

Description

Technical Field

[0001] This application relates to the field of medical catheter technology, specifically to a shape-measuring catheter, particularly for use in minimally invasive interventional treatments. Background Technology

[0002] In minimally invasive interventional surgery, catheters are widely used as channels to deliver medical devices (such as self-expanding stents, balloons, embolization devices, etc.) to target sites within the patient's body. Especially in the field of neurointerventional therapy, due to the complex and tortuous anatomy of cerebral blood vessels, the procedure requires catheters to possess sufficient flexibility and maneuverability during delivery to safely navigate through convoluted vascular pathways; and also sufficient radial support and axial stability once at the target location to provide a reliable and stable pathway for the subsequent release of medical devices.

[0003] Existing technologies already include adjustable stiffness catheters or shape-adjustable catheters that can switch between a relatively compliant, non-shape-adjustable state and a relatively rigid, shape-adjustable state, in order to balance the flexibility of the catheter during delivery with its support at the target location.

[0004] However, these catheters still have many shortcomings. On the one hand, when existing catheters are transformed from an unshaped to a shaped state, they usually rely solely on the static friction between the layers of the catheter wall to increase hardness and maintain relative position, lacking a reliable interlocking mechanism between layers. This shaping method, which relies solely on material deformation or frictional resistance, is prone to undesirable relative displacement or even axial displacement (retreat) when the catheter is subjected to axial thrust or the reverse force from the release of the medical device (such as the recoil force generated on the catheter during the release of a self-expanding stent from the distal opening of the catheter). This causes the actual release position of the medical device to deviate from the intended position, affecting the surgical outcome. On the other hand, when some existing catheters are shaped in a curved configuration, the uneven deformation of the catheter layers in the curved state makes it difficult to form a stable and consistent bonding force between the layers. This leads to a decrease in the shaping stability and reliability of the catheter in complex curved shapes, making it impossible to achieve effective "in-situ" shaping in various vascular curved configurations. In addition, in cases such as neurointerventions where strong and stable support is required from the proximal part of the catheter, the anti-displacement ability and structural rigidity of existing catheters after shaping still need to be improved. Summary of the Invention

[0005] The purpose of this application is to solve one or more of the aforementioned technical problems.

[0006] The shapeable conduit of this application defines a central lumen and includes: a first hardness layer and a second hardness layer defining an annular cavity configured to receive liquid, and a support layer disposed adjacent to the first hardness layer. The first hardness layer is made of an elastic material having a first hardness, the second hardness layer is made of a material having a second hardness, and the support layer has a recess on its surface facing the first hardness layer. The second hardness is greater than the first hardness. The shapeable conduit has a shaped state and an unshaped state and changes between the shaped state and the unshaped state in response to the liquid pressure within the annular cavity. In the shaped state, the first hardness layer is in a deformed state, partially embedded in the recess of the support layer, mechanically interlocking the first hardness layer with the support layer. In the unshaped state, the first hardness layer is in a non-deformed state, allowing relative displacement between itself and the support layer.

[0007] In some embodiments, the second hardness is in the range of 55D to 72D; the first hardness is in the range of 25D to 40D or 70A to 90A.

[0008] In some embodiments, the first hardening layer is made of a thermoplastic elastic material.

[0009] In some embodiments, the material forming the first hardness layer is Pebax 25D or 35D or TPU; the material forming the second hardness layer is Pebax 72D or Nylon 12.

[0010] In some embodiments, the support layer includes a braided structure and / or a spring structure, wherein the recess is a mesh hole of the braided structure and / or a turn gap of the spring structure.

[0011] In some embodiments, the braided structure is formed by cross-woven metal wires. In some embodiments, the spring structure is formed by winding flat or round stainless steel wire or nickel-titanium alloy wire. In some embodiments, the support layer includes one or more braided layers and / or one or more spring layers arranged in the radial direction.

[0012] In some embodiments, when the braided layer is arranged adjacent to the first stiffening layer and mechanically interlocked, the braiding density of the braided structure is 60-120 PPI; and / or, when the spring layer is arranged adjacent to the first stiffening layer and mechanically interlocked, the pitch of the spring structure is in the range of 0.5 times the spring wire diameter to 1.0 times the spring wire diameter.

[0013] In some embodiments, in the unshaped state, there is a gap between the first hardening layer and the support layer or they are directly bonded; and / or, in the shaped state, the first hardening layer includes a protrusion extending into the recess, and in the unshaped state, the first hardening layer includes a reduced-size protrusion or does not include a protrusion.

[0014] In some embodiments, the first hardness layer is located radially inside the second hardness layer.

[0015] In some embodiments, the second hardening layer is the outermost layer of the shapeable conduit.

[0016] In some embodiments, the first hardness layer is located radially outside the second hardness layer.

[0017] In some embodiments, the device further includes a catheter hub connected to the proximal end of the shapeable catheter, the catheter hub including a first channel communicating with the central lumen and a second channel communicating with the annular cavity.

[0018] Using the conduit of this application, the transition between a shaped and unshaped state is achieved by controlling the change in liquid pressure within the annular cavity. In the shaped state, the deformed first hardened layer and the supporting layer mechanically interfere and interlock, preventing relative displacement between them. The mechanical interference force ensures the stability and reliability of the conduit's shaping.

[0019] For the shape-adjustable catheter of this application, by maintaining the fluid pressure within the annular lumen of the catheter, the fluid pressure is reliably converted into mechanical interference force between the first rigid layer and the support layer, achieving mechanical interlocking and interference engagement. Regardless of the catheter's configuration or state, the catheter can be reliably "in situ" shaped into its current configuration. During the release of a medical device (e.g., a self-expanding stent) delivered to the patient via this catheter, the catheter itself is shaped and becomes sufficiently rigid to provide adequate support for the released medical device, preventing displacement (or retraction) and ensuring accurate release positioning. In neurointerventional therapy applications, the proximal portion is sufficiently rigid, allowing the catheter being delivered to the patient to conform to vascular conditions, providing strong and stable support for access establishment. Attached Figure Description

[0020] The above and other aspects of this application will now be described more fully with reference to the accompanying drawings. It should be noted that the drawings are schematic only and not to scale. In different drawings, the same components are indicated by the same reference numerals. It should be understood that the dimensions, scale relationships, and number of components or parts in the drawings do not constitute a limitation on this application.

[0021] Figure 1This is a schematic diagram of the sculptable catheter and catheter seat assembled together according to this application.

[0022] Figure 2 This is a cross-sectional view of the catheter.

[0023] Figure 3 A partially enlarged longitudinal section of the catheter before liquid injection into the annular cavity is shown.

[0024] Figure 4 This shows a partially enlarged longitudinal section of a conduit that has been shaped after the liquid in the annular cavity reaches a predetermined pressure.

[0025] Figure 5 An embodiment is shown in which the first rigid layer defining the annular cavity in the unshaped state of the catheter also has a protrusion extending toward the braided layer.

[0026] Figure 6 A partial longitudinal section of another embodiment of the catheter is shown. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, not all embodiments. The following description of the embodiments is merely illustrative and does not constitute any limitation on this application and its application. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This application relates to shapeable catheters in the field of medical devices. The catheter of this application can be used to establish a pathway for delivering medical devices (such as self-expanding stents) within a patient's body, while simultaneously performing the delivery of the self-expanding stent. The catheter of this application can be used, but is not limited to, in neurointerventional surgical pathways during intracranial treatment procedures.

[0029] Figure 1 The illustration shows the catheter 10 of this application assembled with a catheter seat 15. The catheter seat 15 has a Y-shaped dual-channel configuration; for example, the catheter seat 15 can be a dual-channel Luer connector or any known similar structure. The first channel (sometimes also called the main channel) in the dual-channel configuration communicates with the central lumen 25 of the catheter. Figure 2 For example, it is used for intravascular injection of contrast agents into a patient's blood vessels; the second channel (sometimes also called a side channel) communicates with the annular lumen 70 of the catheter 10 for injecting and releasing fluid, such as saline, into the annular lumen 70 for shaping the catheter. Accordingly, the ends of the first and second channels opposite to the end connected to the catheter 10 are respectively connected to an external fluid (contrast agent or shaping fluid) supply source, such as a pressure pump. This will be described in detail below.

[0030] The catheter 10 extends axially along its central axis and has a first end 10a and a second end 10b opposite in the axial direction. The first end 10a is connected to the catheter hub 15 and is the operating end operated by an operator, also referred to in the art as the "proximal end," while the second end 10b serves as the anterior portion when inserted into the patient's body, also referred to as the "crown end" or "distal end." The second end 10b can be configured as a flexible distal end. Since the details of the flexible distal end are not the focus of this application, they are only shown schematically.

[0031] Figure 2 The cross-sectional structure of the conduit 10 is shown, for example along... Figure 1 The cross section of AA.

[0032] refer to Figure 2 A cross-sectional view shows that the conduit 10 includes an innermost layer 20, a spring layer 30 radially surrounding the innermost layer 20, a braided layer 40 radially surrounding the spring layer 30, a first hard layer 50 radially surrounding the braided layer 40, and a second hard layer 60 radially surrounding the first hard layer 50. An annular cavity or annular gap 70 is formed between the first hard layer 50 and the second hard layer 60. In the illustrated example, the second hard layer 60 is the outermost layer of the conduit 10. As described above, the annular cavity 70 communicates with a second or side channel of the conduit seat 15 to receive liquid injected from the conduit seat 15.

[0033] The innermost layer 20 is a coating applied to the inner circumference of the spring layer 30. The coating may be PTFE (polytetrafluoroethylene) or a similar material to ensure that the inner surface of the central lumen 25 of the catheter 10 is smooth and flat, facilitating the passage of delivered medical devices (such as self-expanding stents).

[0034] Spring layer 30 is a spring formed by winding one or more strands of braided wire. The spring pitch can be constant along the axial direction or gradually increase in the direction toward the distal end 10b. The braided wire can be flat or round wire, and an exemplary cross-sectional dimension of the flat wire can be 0.001" x 0.003". The material of the braided wire used to wind the spring can be stainless steel or other materials commonly used in the art.

[0035] The braided layer 40 is a tubular structure with a mesh-like opening formed by weaving braided filaments, such as 8-strand or 16-strand braided filaments. The material of the braided filaments can be, but is not limited to, metals, such as nickel-titanium alloys. The braiding density of the braided layer 40 should be appropriately designed to facilitate and ensure that the first hardened layer 50, which deforms towards it, can be embedded within the mesh openings of the braided layer 40, as described in detail below. As an example, the braiding density of the braided layer 40 can be 60-120 PPI (intersections per inch), thus forming a mesh opening (gap) size suitable for embedding the adjacent first hardened layer 50 after deformation. Figure 2 sectional view and Figure 3 A partially enlarged view of the conduit 10 in its initial or unformed state is shown, with the braided layer 40 closely attached to the spring layer 30 on its radially inner side and the first rigid layer 50 on its radially outer side, while the mesh holes 44 of the braided layer 40 ( Figure 3 It is open to the spring layer 30 and the first hardness layer 50.

[0036] In the radial direction, the first hardening layer 50 and the second hardening layer 60 define the annular cavity 70.

[0037] Figure 3 The diagram illustrates the initial state of the conduit 10 in an unshaped condition. The annular cavity 70 is empty of liquid or the liquid is at atmospheric pressure. The first hardening layer 50 covers the braided layer 40, but there is no mechanical interference between the braided layer 40 and the first hardening layer 50. Here, "no mechanical interference" can mean that relative displacement can occur between them, for example, in the axial direction and / or the circumferential direction. Specifically, the inner circumferential surface of the first hardening layer 50 is generally smooth and does not protrude into the mesh holes 44 of the braided layer 40. At this point, the conduit 10 exhibits maximum flexibility.

[0038] The first hardness layer 50 is made of a polymer material having a first hardness, and the second hardness layer 60 is made of a material having a second hardness greater than the first hardness. For example, the first hardness can be in the range of 20D-40D or 70A-90A, and the second hardness can be in the range of 55D-72D. Both the second hardness and the hardness of the braided metal layer 40 are greater than the first hardness, and the second hardness is chosen to be sufficiently large such that when the liquid in the annular cavity 70 has a certain or predetermined pressure, the second hardness layer 60 forces the liquid to deform the first hardness layer 50 into the mesh holes 44 of the braided layer 40, without causing the second hardness layer 60 to deform outwards or with negligible deformation. At this time, the conduit 10 enters the shaped state, such as... Figure 4 As shown.

[0039] Specifically, after the first hardening layer 50 is pressed against the outer periphery of the braided layer 40 by the liquid in the annular cavity 70, since the hardness of the braided layer 40 (the metal material) is also greater than the first hardness of the first hardening layer 50, the first hardening layer 50 forms a protrusion 52 under the reaction force of the braided mesh structure of the braided layer 40. The protrusion 52 extends into the mesh holes 44 of the braided layer 40 and abuts and interferes with the braided layer 40. In this way, mechanical interference or interlocking is formed between the first hardening layer 50 and the braided layer 40, which effectively prevents the braided layer 40 from shifting relative to the first hardening layer 50 in the radial and axial directions, and realizes the shaping of the conduit 10. It can be understood that as long as the liquid pressure in the annular cavity 70 is sufficient or reaches a predetermined pressure value, the conduit 10 is shaped, regardless of whether the conduit 10 is in a straight configuration or a curved configuration, and regardless of the bending angle of the conduit 10. The conduit shaping achieved by mechanical interference in this application is stable and reliable.

[0040] Furthermore, the material with a first hardness used to form the first hardness layer 50 can be an elastic material, such that when the liquid pressure within the annular cavity 70 is released (e.g., released to atmospheric pressure), the first hardness layer 50 can return to or recover to its original state. Figure 3 The first hardness layer 50 and the braided layer 40 are in an initial state where they do not interfere with each other. Some examples of elastic polymer materials that meet the first hardness range include Pebax 25D or 35D, or TPU of equivalent hardness. Examples of materials that can be used as the second hardness layer 60 are Pebax 72D or Nylon 12, etc. Of course, this application is not limited to these listed materials while satisfying the above-described functions.

[0041] For the illustrated conduit 10, an example of a liquid pressure capable of achieving the shaping effect is 10-20 atm. The gap size of the annular cavity 70 can be in the range of 0.02 mm - 0.05 mm. However, these are not limiting.

[0042] According to the example shown in the diagram, Figure 3 In its unformed state, the inner circumferential surface of the first hard layer 50 is tightly attached to the braided layer 40. However, this application is not limited to this, and it is also possible for there to be a small gap between the first hard layer 50 and the braided layer 40.

[0043] According to the example shown in the figure, the first hard layer 50 can be described as including at least one protrusion 52 in the shaped state, which is at least partially embedded in the mesh hole 44 of the braided layer 40, but does not include any protrusion 52 in the unshaped or initial state. The protrusion 52 is an "uneven" feature formed by the liquid in the annular cavity 70 pressing the first hard layer 50 against the outer periphery of the braided layer 40.

[0044] However, it is conceivable that in Figure 3In its unformed state, the first hard layer 50 may have protrusions on its inner circumferential surface facing the braided layer 40. However, the situation where the size of the protrusions is insufficient to cause mechanical interference with the braided layer 40 is also within the scope of this application. For example, Figure 5 The diagram also shows the initial unshaped state of the conduit. The protrusion 52 of the first hard layer 50 extends into the mesh hole 44 of the braided layer 40, but there is a gap 54 between the two, so relative displacement can still occur between the first hard layer 50 and the braided layer 40.

[0045] For example, when the conduit 10 is in an unformed state, the inner circumferential surface of the first hardness layer 50 does not have Figure 5 The protrusion 52, but it is also possible that at least part or all of the inner circumferential surface has a minute gap 54 between it and the braided layer 40. During the process of the conduit 10 changing to its final shape, the first hardened layer 50 is gradually pressed against the braided layer 40, eliminating the gap between them. Then, the liquid pressure within the annular cavity 70 further increases, forming a gap between the first hardened layer 50 and the braided layer 40. Figure 4 The mechanical interference is shown. The conduit 10 enters the shaping state. Therefore, the first hardening layer 50 of the conduit 10 of this application may or may not include the protrusion 52 on the inner circumferential surface.

[0046] Although the second hardening layer 60 is shown as the outermost layer of the conduit 10 in the illustrated example, this application is not limited thereto. Other layered structures outside the second hardening layer 60 are also within the scope of this application.

[0047] Although in the illustrated example, the feature that mechanically interferes with the first hardened layer 50 deformed by liquid compression is the mesh hole 44 feature on the braided layer 40, the first hardened layer 50 can be adjacent to any other cylindrical layer structure (referred to herein as a "support layer") to satisfy the requirement of interference engagement with the elastically deformable first hardened layer 50, provided that the material hardness of the support layer is greater than that of the first hardened layer 50 and includes uneven or recessed features on the outer peripheral surface facing the first hardened layer 50. As an example, the braided layer 40 can be replaced with a spring layer as the support layer, in which case the first hardened layer 50 can mechanically embed itself within the turn gaps of the spring layer when deformed by liquid compression, achieving mechanical interference and thus achieving the same technical effect as described in this application. In this case, preferably, the pitch of the spring structure is in the range of 0.5 times the spring wire diameter to 1.0 times the spring wire diameter. Of course, any combination of spring structure and braided structure adjacent to the first hardened layer 50 is also within the scope of this application. Furthermore, the feature that interferes with the first hardness layer 50 does not necessarily have to be a mesh hole; any recess in a structure that can achieve the same function is within the scope of this application.

[0048] As described above, the shapeable conduit of this application achieves the purpose of a reliable, stable, in-situ shaped conduit 10 through a combination that can be described as "support layer - first hardness layer 50 - annular cavity 70 - second hardness layer 60". The first hardness layer 50 is made of an elastic material, the hardness of the support layer and the second hardness layer 60 are both greater than the hardness of the first hardness layer 50, and the support layer includes a recessed feature (or uneven structure) on its surface facing the first hardness layer 50. When the first hardness layer 50 is elastically deformed by the liquid within the annular cavity 70, it forms a protrusion 52 that can embed into the recess on the support layer, forming an interference engagement. This causes mechanical interference and interlocking between the first hardness layer 50 and the support layer, and when the liquid pressure is released, it can disengage from the interference engagement with the support layer (the recess), returning to a state where the first hardness layer 50 and the support layer can be displaced relative to each other. The support layer can be a braided layer 40 or a spring layer 30, or a combination of both.

[0049] Although the braided layer 40 and the spring layer 30 are shown in the figure and described above as two adjacent separate layers, the braided layer 40 and the spring layer 30 can be a hybrid layer structure interwoven together, such as the aforementioned support layer. In a specific example, the support layer arranged adjacent to each other on the radially inner side of the first stiffness layer 50 can be one or more braided layers 40 and one or more spring layers 30 arranged in any order.

[0050] Although the preceding description with reference to the accompanying drawings is based on a layer combination of "support layer - first hardening layer 50 - annular cavity 70 - second hardening layer 60" arranged radially from the inside out, i.e., the first hardening layer 50, made of a less hard elastic material, and the second hardening layer 60, made of a harder material, are located radially inside and radially outside the annular cavity 70, respectively, this application also contemplates the opposite scenario, where the second hardening layer 60 is located radially inside the first hardening layer 50. In this case, the support layer, which is adjacent to the first hardening layer 50 and mechanically interferes with and interlocks with it in its shaped state, is located radially outside the first hardening layer 50. An exemplary layer arrangement of the conduit used in this scenario is as follows: Figure 6 As shown, the layers are arranged radially from the inside out as follows: innermost layer 20 (PTFE coating) - spring layer 30 - braided layer 40 - second hardness layer 60 - annular cavity 70 - first hardness layer 50 - support layer 80 (as described above with braided and / or spring structures) - outermost layer 90. It should be understood that, except for the adjacent arrangement of "second hardness layer 60 - annular cavity 70 - first hardness layer 50 - support layer 80" from the inside out, the other layer structures can be modified. All other details described above regarding the inner-outer layer combination "support layer - first hardness layer 50 - annular cavity 70 - second hardness layer 60" apply to the inner-outer layer combination "second hardness layer 60 - annular cavity 70 - first hardness layer 50 - support layer 80".

[0051] Because the catheter of this application achieves its shape solely by pressurizing the fluid within the annular cavity 75, regardless of the actual configuration of the catheter 10 (whether it is straight or curved, and the degree of curvature), this application achieves "stepless" shaping, meaning that the catheter 10 can be shaped into any (continuous) curvature configuration. This allows the principle of this application to be applied in a very wide range of scenarios or to catheters used in different surgeries.

[0052] When using the catheter 10 of this application, during the process of pushing the catheter 10 (e.g., carrying a medical device within its central lumen 25) to a target site (e.g., an intracranial target site) within the patient's body, considerable flexibility is required because it needs to traverse the bends of various anatomical structures. This flexibility is provided by a first hardness layer 50 made of a less rigid elastic material and an internal spring structure. When the catheter 10 is pushed to the target site within the patient's body and it is necessary to release the medical device from the central lumen 25, the catheter 10 needs to have relative rigidity and provide sufficient stability and support. At this time, a liquid such as saline is injected into the annular cavity 70 through the side channel of the catheter seat 15 and pressurized to a preset pressure. According to the principle described above, the liquid pressure is converted into mechanical locking force and interference force, and the catheter 10 quickly hardens and reliably settles into its current configuration, ensuring the stability of the catheter 10 during the release of the medical device without any displacement or slippage. Thus, the correct position of the medical device is ensured. After the procedure is completed, the fluid pressure in the annular cavity 70 is released, and the catheter 10 returns to its pliability, after which it can be withdrawn from the patient's body.

[0053] Depending on actual needs, the catheter 10 can have [specific features] along its entire length in the axial direction. Figure 2 Alternatively, the conduit 10 may have a segmented structure along its axial direction, and the cross-sectional structure illustrated in the description of this application may extend only a portion of the length of the conduit 10.

[0054] The catheter of this application can reliably achieve in-situ shaping in response to changes in liquid pressure under any bending configuration, and provides sufficient axial support and anti-displacement capability through a stable mechanical interlocking mechanism in the shaped state, so as to ensure accurate release of medical devices and stable establishment of interventional access.

[0055] In this application, the terms "first," "second," etc., are used only to distinguish one component or part from another, but these components or parts should not be limited by such terms.

[0056] The present application has been described in detail above with reference to specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and not as limiting the present application. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and such modifications or alterations do not depart from the scope of the present application.

Claims

1. A shapeable catheter (10) defining a central lumen (25), wherein, The shapeable conduit (10) includes: a first hardness layer (50) and a second hardness layer (60) defining an annular cavity (70) configured to receive liquid, and a support layer disposed adjacent to the first hardness layer (50). The first hardness layer (50) is made of an elastic material having a first hardness, and the second hardness layer (60) is made of a material having a second hardness. The support layer has a recess on its surface facing the first hardness layer (50). The second hardness is greater than the first hardness. The shapeable conduit (10) has a shaped state and an unshaped state and changes between the shaped state and the unshaped state in response to the liquid pressure in the annular cavity (70). In the shaped state, the first hardness layer (50) is in a deformed state in which it is partially embedded in the recess of the support layer, mechanically interlocking the first hardness layer (50) with the support layer. In the unshaped state, the first hardness layer (50) is in a non-deformed state in which relative displacement between the first hardness layer (50) and the support layer is permitted.

2. The shape-adjustable catheter (10) according to claim 1, wherein, The second hardness is in the range of 55D to 72D; the first hardness is in the range of 25D to 40D or 70A to 90A.

3. The shape-adjustable catheter (10) according to claim 2, wherein, The first hardness layer (50) is made of thermoplastic elastic material.

4. The shape-adjustable catheter (10) according to claim 3, wherein, The material forming the first hardness layer (50) is Pebax 25D or 35D or TPU; the material forming the second hardness layer (60) is Pebax 72D or Nylon 12.

5. The shape-adjustable catheter (10) according to claim 1, wherein, The support layer includes a braided structure and / or a spring structure, and the recess is a mesh hole (44) of the braided structure and / or a turn gap of the spring structure.

6. The shape-adjustable catheter (10) according to claim 5, characterized in that... At least one of the following: The braided structure is made of interwoven metal wires; The spring structure is made of flat or round stainless steel wire or nickel-titanium alloy wire. The support layer includes one or more braided layers (40) and / or one or more spring layers (30) arranged in the radial direction.

7. The shape-adjustable catheter (10) according to claim 6, wherein: When the braided layer (40) and the first hard layer (50) are arranged adjacent to each other and mechanically interlocked, the braiding density of the braided structure is 60-120 PPI; When the spring layer is arranged adjacent to the first hardness layer (50) and mechanically interlocked, the pitch of the spring structure is in the range of 0.5 times the spring wire diameter to 1.0 times the spring wire diameter.

8. The shape-adjustable catheter (10) according to any one of claims 1-7, wherein, In the non-formed state, there is a gap or direct adhesion between the first hardening layer (50) and the support layer; and / or In the shaped state, the first hardening layer (50) includes a protrusion (52) extending into the recess, and in the unshaped state, the first hardening layer (50) includes a reduced-size protrusion or does not include a protrusion.

9. The shape-adjustable catheter (10) according to any one of claims 1-7, wherein, The first hardness layer (50) is located radially inside the second hardness layer (60).

10. The shape-adjustable catheter (10) according to claim 9, characterized in that, The second hardness layer (60) is the outermost layer of the shapeable conduit (10).

11. The shape-adjustable catheter (10) according to any one of claims 1-7, wherein, The first hardness layer (50) is located radially outside the second hardness layer (60).

12. The shape-adjustable catheter (10) according to any one of claims 1-7, wherein, It also includes a catheter seat (15) connected to the proximal end (10b) of the shapeable catheter (10), the catheter seat (15) including a first channel communicating with the central lumen (25) and a second channel communicating with the annular cavity (70).

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