CN110755730A

CN110755730A - Catheter and conveying device

Info

Publication number: CN110755730A
Application number: CN201810847228.2A
Authority: CN
Inventors: 刘丰洋
Original assignee: Minimally Invasive Shentong Medical Technology (shanghai) Co Ltd
Current assignee: Minimally Invasive Shentong Medical Technology (shanghai) Co Ltd; Microport Neurotech Shanghai Co Ltd
Priority date: 2018-07-27
Filing date: 2018-07-27
Publication date: 2020-02-07

Abstract

The invention provides a catheter applied to the technical field of medical instruments. The catheter is along the radial inlayer, intermediate level and the skin of including in proper order from inside to outside of catheter, the intermediate level includes the basal layer, wherein the intermediate level includes liquid crystal polymer silk. The catheter has the characteristics of high flexibility of the far end and good support performance of the near end, is good in integrity, and improves pushing efficiency.

Description

Catheter and conveying device

Technical Field

The invention relates to the technical field of medical instruments, in particular to a catheter and a conveying device.

Background

The nerve interventional therapy is a new means for treating cerebrovascular diseases, and achieves satisfactory treatment effect while causing smaller physical trauma to patients by methods such as embolism, dilation forming and mechanical clearing. Intracranial delivery catheters play an irreplaceable role in neurosurgical procedures. In the nerve interventional therapy operation, an intracranial delivery catheter reaches a lesion part under the guidance of a micro guide wire to establish a passage for subsequent instruments. In addition, intracranial delivery catheters can also be used to directly aspirate thrombi during embolectomy procedures when large vessels are occluded.

The intracranial delivery catheter has high performance requirements, needs to be soft at the far end and can reach a far treatment area through a bent blood vessel, namely needs to have good bending resistance and certain hardness so that the intracranial delivery catheter can smoothly advance along the blood vessel, and also needs to be free from collapse under certain pressure so as to keep the shape of an inner cavity complete and be convenient for other instruments to pass through, namely needs to have good lumen holding capacity. Intracranial delivery catheters also need to have less resistance to pushing and good support capabilities.

At present, two representative products are arranged in an intracranial delivery catheter in the market, one of the two representative products adopts a flat wire full-winding structure, the support performance of the proximal end of the intracranial delivery catheter is guaranteed, but the size of the flat wire is too large, so that the softness of the distal end of the intracranial delivery catheter is insufficient, and the intracranial delivery catheter cannot reach higher (far end) lesion positions such as island sections of middle cerebral arteries. The other intracranial delivery catheter is made of a full 304 stainless steel material, the inner layer of the intracranial delivery catheter is of a full winding structure, the outer layer of the intracranial delivery catheter is of a woven structure, the intracranial delivery catheter is of a full winding structure, the wire diameter of a stainless steel wire adopted by the full winding structure is small, so that the intracranial delivery catheter is soft in whole body, namely good in softness, and can reach higher lesion positions such as island segments of middle cerebral arteries and the like, but the proximal end of the intracranial delivery catheter is poor in supporting performance, so that the intracranial delivery catheter is easy to slide from the lesion positions to the proximal end in a blood vessel in the operation process, namely the intracranial delivery catheter is easy to withdraw, and other instruments are not convenient to pass through. In addition, the lumen retention capacity of the two catheters is not perfect, so that when the catheter is in a tortuous vessel, the subsequent instruments are difficult to pass through.

It can be seen that too large a wire diameter of the braided wire in the catheter causes problems of increased tube diameter and too stiff distal end, while too small a wire diameter causes other problems, such as reduced ovality resistance and lumen retention, and the existing catheter cannot always have both softness at the distal end and support at the proximal end.

Disclosure of Invention

The invention aims to provide a catheter and a conveying device, which aim to solve the problem that the flexibility of the distal end and the support performance of the proximal end of the conventional catheter cannot be combined.

In order to solve the technical problem, the invention provides a catheter which sequentially comprises an inner layer, a middle layer and an outer layer from inside to outside along the radial direction of the catheter, wherein the middle layer comprises a base layer, and the middle layer comprises liquid crystal polymer filaments.

Optionally, the basal layer cover is established on the surface of inlayer, the basal layer is followed the axial of pipe includes distal end basal layer and near-end basal layer from distal end to near-end in proper order, distal end basal layer includes the first winding wire of at least one share, near-end basal layer includes the second winding wire of at least one share.

Optionally, the middle layer further includes a reinforcing layer, the reinforcing layer is sleeved on at least part of the outer surface of the base layer, and the liquid crystal polymer filaments are disposed in the base layer and/or the reinforcing layer.

Optionally, the reinforcing layer is a woven layer.

Optionally, the woven layer comprises a plurality of strands of liquid crystal polymer filaments; or the braided layer comprises at least one strand of liquid crystal polymer filament and at least one strand of metal filament or other high molecular filaments; or the braided layer comprises a plurality of strands of filaments, and each strand of filament is formed by mixing a liquid crystal polymer filament and a metal filament or other high polymer filaments.

Optionally, the braided layer gradually changes from density to density from the distal end to the proximal end.

Optionally, the distal base layer and/or the proximal base layer comprise liquid crystal polymer filaments.

Optionally, a plurality of the first winding wires are helically wound in a co-rotating helical manner around the outer surface of the inner layer in a distal to proximal direction of the catheter, and/or a plurality of the second winding wires are helically wound in a co-rotating helical manner around the outer surface of the inner layer in a distal to proximal direction of the catheter.

Optionally, the distal base layer includes at least two first winding wires, wherein at least one first winding wire is a liquid crystal polymer wire, and at least one first winding wire is a metal wire or other polymer wire; or the distal base layer comprises a plurality of first wound filaments, each of which is a liquid crystal polymer filament.

Optionally, the proximal base layer comprises at least two strands of second winding wires, wherein at least one strand of the second winding wires is a liquid crystal polymer wire, and at least one strand of the second winding wires is a metal wire or other polymer wire; or the proximal base layer comprises a plurality of second winding wires, each of which is a liquid crystal polymer wire.

Optionally, the first winding wire is a round wire, and the second winding wire is a flat wire.

Optionally, the second winding wire is wound on the outer surface of the inner layer in a variable pitch manner in a proximal direction along the distal end of the catheter, and the pitch is gradually reduced or gradually reduced in a segment manner in the proximal direction along the distal end of the catheter.

Optionally, the reinforcing layer is fitted over at least part of the outer surface of the proximal base layer.

The invention also provides a conveying device which comprises the stress diffusion tube, the developing ring and the catheter, wherein the far end of the stress diffusion tube is connected with the near end of the catheter, and the developing ring is sleeved on the far end of the catheter.

The catheter and the conveying device provided by the invention have the following beneficial effects:

because the middle layer of the catheter comprises the liquid crystal polymer wire, the material has higher tensile strength and bending modulus, so that the far end of the catheter can be softer and/or the near end of the catheter can have better supporting performance, and meanwhile, the catheter can have lower pushing resistance, and therefore, the catheter can have the characteristics of good near end supporting performance, small pushing resistance and better far end softness. In addition, the liquid crystal polymer wire has certain shrinkage after being heated, the outer diameter of the guide pipe can be reduced when the inner diameter is the same, the combination degree between layers is effectively improved, the integrity of the guide pipe is improved, and therefore the pushing efficiency of the guide pipe is improved.

Drawings

FIG. 1 is a schematic axial cross-sectional view of a catheter in accordance with a first embodiment of the invention;

FIG. 2 is an enlarged, fragmentary, schematic view of a catheter according to one embodiment of the invention;

FIG. 3 is a schematic radial cross-sectional view of a catheter in accordance with a first embodiment of the invention;

FIG. 4 is another enlarged partial schematic view of a catheter according to a first embodiment of the invention;

FIG. 5 is an enlarged, fragmentary, schematic view of a catheter embodying three aspects of the invention;

FIG. 6 is a graph comparing the stiffness of a catheter of a third embodiment of the invention with a catheter of the same construction of this embodiment but with the distal base layer comprising only NiTi wires (not LCP wires);

figure 7 is a graph comparing the anti-ovality of a catheter of the third embodiment of the present invention with a catheter of the same construction as the first embodiment but not containing LCP filaments;

fig. 8 is a schematic structural view of a conveying apparatus in an eighth embodiment of the present invention.

Description of reference numerals:

100-a catheter; 100' -a catheter;

110-an inner layer;

120-an intermediate layer; 121, 121a, 121 b-a first winding wire; 122-a second wrap wire; 123-a reinforcing layer; 124-intersection point;

130-an outer layer;

200-a stress diffusion tube;

300-a connector;

400-developing ring.

Detailed Description

The catheter and delivery device of the present invention are described in further detail below with reference to the figures and the specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Example one

The present embodiments provide a catheter. Fig. 1 is a schematic axial cross-sectional view of a catheter in accordance with a first embodiment of the present invention, and as shown in fig. 1, the catheter 100 includes an inner layer 110, an intermediate layer 120 and an outer layer 130 in this order from inside to outside along a radial direction of the catheter. The outer layer 130 is disposed over the outer surface of the middle layer 120. Wherein the intermediate layer 120 comprises a distal base layer in the shape of a tube and a proximal base layer in the shape of a tube. The far-end foundation layer and the near-end foundation layer are sequentially sleeved on the outer surface of the far end of the inner layer 110 and the outer surface of the near end of the inner layer 110. The middle layer 120 further includes a tubular reinforcing layer 123, and the reinforcing layer 123 is sleeved on the outer surface of the proximal base layer. Wherein the reinforcement layer 123 comprises Liquid Crystal Polymer (LCP) filaments.

Since the proximal end of the distal base layer and the distal end of the proximal base layer in the middle layer 120 of the catheter 100 are connected to each other, the distal base layer and the proximal base layer are sleeved on the outer surface of the inner layer 110 together, the reinforcing layer 123 is sleeved on the outer surface of the proximal base layer, and the reinforcing layer 123 further includes Liquid Crystal Polymer (LCP) filaments, the distal end of the catheter 100 (the position of the distal end of the catheter 100 is the same as the position of the distal end of the distal base layer) is softer than the proximal end of the catheter 100 (the position of the proximal end of the catheter 100 is the same as the position of the proximal end of the proximal base layer), the proximal end of the catheter 100 can have better support performance than the distal end of the catheter 100, and at the same time, the catheter 100 can have smaller pushing resistance, thereby improving the efficiency of the interventional therapy. In addition, since the distal end of the intermediate layer 120 includes only a distal base layer, not a reinforcing layer, the distal end of the catheter 100 may have better softness. As can be seen from the above, the catheter 100 has the characteristics of good proximal support performance, low pushing resistance, and good distal flexibility.

In addition, the LCP filaments shrink to some extent after heating, which can reduce the outer diameter of the catheter 100 when the inner diameter is the same, and improve the degree of bonding between layers, improve the integrity of the catheter 100, thereby improving the pushing efficiency of the catheter 100.

The material of the inner layer 110 of the catheter 100 includes but is not limited to PTFE (polytetrafluoroethylene). The inner layer 110 is preferably made by tube extrusion, and the characteristics of the PTFE material itself make the inner surface of the inner layer 110 smooth, which facilitates the smooth passage of a guide wire or other instruments through the lumen of the catheter 100.

The material of the outer layer 130 of the catheter 100 includes PA (polyamide), PU (polyurethane) or polyurethanePebax (block polyether amide) or the like, wherein PU includes TPU (thermoplastic polyurethane). The outer layer 130 may be partially added with BaSO₄Or Bi₂O₃For example, by adding BaSO to a partial section of the outer layer 130₄Or Bi₂O₃To ensure the developability of the outer layer 130. At least a portion of the outer surface of the outer layer 130 along the length of the catheter 100 may be coated with a hydrophilic coating to reduce resistance to advancement of the catheter 100 through a blood vessel. The outer layer 130 preferably comprises a plurality of sections of polymer tubes with different hardness and different wall thickness, and the outer layer 130 material with different hardness is sequentially sleeved on the outer surface of the middle layer 120 from low hardness to high hardness from the distal end to the proximal end of the catheter 100, so as to further ensure the flexibility of the distal end and the hardness of the proximal end of the catheter 100.

Fig. 2 is a partially enlarged view of a catheter tube a in a first embodiment of the invention, and fig. 3 is a view of a radial cross-section of a catheter tube 100 in a first embodiment of the invention, shown only as an inner layer and an intermediate layer, with the outer layer 130 not shown. Referring to fig. 1, 2 and 3, in the intermediate layer 120, the reinforcing layer 123 is a woven layer, and the woven layer may be formed by weaving a plurality of strands of LCP filaments.

In particular, with reference to fig. 2, the woven layer comprises a plurality of diamond-shaped lattice structures. The plurality of LCP filaments can be woven by conventional weaving methods, such as one over the other (as shown in fig. 1, 2, and 3), two over the other, or other weaving methods to form a diamond-shaped lattice structure, thereby providing superior support to the proximal portion of the catheter 100, while increasing the force transfer efficiency and thus providing less resistance to the pushing of the catheter 100.

To further improve the performance of the reinforcing layer 123, the braided layer is sparse at the distal end and dense at the proximal end, and becomes dense gradually or gradually from the distal end to the proximal end, so that the force of the catheter 100 from the proximal end to the distal end can be uniformly transmitted while improving the supporting performance of the catheter 100 and reducing the pushing resistance of the catheter 100, and the flexibility of the distal end part of the catheter 100 is ensured. Specifically, a plurality of intersections 124 are formed between the plurality of filaments in the braid. The spacing between two axially adjacent intersection points 124 along the catheter 100 tapers from the distal end of the catheter 100 to the proximal end of the catheter 100 to distribute the braid from sparse to dense from distal to proximal to further improve the support and flexibility of the proximal end of the catheter 100. In other embodiments, the braided layer may be uniform in density, or tapered or segmented from the distal end to the proximal end.

Referring to fig. 1, in the intermediate layer 120, the distal base layer includes a strand of the first winding wire 121, and the strand of the first winding wire 121 is spirally wound on the outer surface of the inner layer 110 in a direction from the distal end of the catheter 100 to the proximal end of the catheter 100, and a direction parallel to the paper surface from left to right in fig. 1 is a direction from the distal end of the catheter 100 to the proximal end of the catheter 100. The proximal base layer includes a second winding wire 122, and the second winding wire 122 is spirally wound on the outer surface of the inner layer 110 in a direction from the distal end of the catheter 100 toward the proximal end of the catheter 100. Wherein the proximal end of the first winding wire 121 may or may not be connected to the distal end of the second winding wire 122.

Specifically, fig. 4 is an enlarged partial schematic view of the catheter 100 at B according to the first embodiment of the present invention, and referring to fig. 1 and 4, the first winding wire 121 is a round wire, that is, the cross-sectional shape of the first winding wire 121 is a circle; the second winding wire 122 is a flat wire, and for example, the cross-sectional shape of the second winding wire 122 is rectangular. Because first winding wire 121 is the circle silk, just second winding wire 122 is the flat silk, and the area of contact of the outward appearance of flat silk spiral winding back and inlayer 110 is big with the area of contact of the outward appearance of inlayer 110 than the circle silk spiral winding back, therefore the support nature of the pipe that has the flat silk part of winding is better than the support nature of the pipe that has the circle silk part of winding, and the pipe that has the circle silk part of winding simultaneously can still keep better compliance and anti ellipse ability. Therefore, when the first winding wire 121 of the distal base layer is a round wire and the second winding wire 122 of the proximal base layer is a flat wire, the distal end of the catheter 100 can have better flexibility and the proximal end can have better support performance. In other embodiments, the first winding wire 121 may be a flat wire and the second winding wire 122 may be a round wire, or both the first winding wire 121 and the second winding wire 122 may be round wires or flat wires.

Further, the reinforcing layer 123 is disposed on a portion of the outer surface of the proximal base layer, and preferably, the reinforcing layer 123 is disposed on the outer surface of the proximal-most portion of the proximal base layer. Because the near-end base layer is a flat wire, the reinforcing layer 123 can be conveniently sleeved on the near-end base layer, and the processing is convenient. In other embodiments, the reinforcing layer 123 may be disposed over the entire outer surface of the proximal base layer and a portion of the outer surface of the distal base layer.

In order to further improve the support performance of the proximal end of the catheter 100 and not affect the flexibility of the distal end of the catheter 100, the second winding wire 122 in the proximal base layer is wound on the outer surface of the inner layer 110 in a variable pitch manner in the direction from the distal end of the catheter 100 to the proximal end of the catheter 100, and the pitch becomes smaller in sequence or in sections from the distal end to the proximal end of the catheter 100. The pitch of the first wrapping wire 121 in the distal base layer in the direction approaching from the distal end of the catheter 100 to the proximal end of the catheter 100 may also be made smaller in sequence or in segments. This enhances the support of the catheter 100 from the distal end to the proximal end, either sequentially or in sections, thereby allowing the force of the catheter 100 from the proximal end to the distal end to be transmitted uniformly and improving the pushing performance of the catheter 100.

The first and second winding

wires

121 and 122 may be nitinol wires, 304 stainless steel wires, copper wires, silver wires, platinum iridium alloy wires, PVC (polyvinyl chloride) wires, ABS (terpolymer of acrylonitrile (a), butadiene (B), and styrene (S)) wires, PLA (polylactic acid) wires, and the like.

Wherein the pitch P of the first and second winding

wires

121 and 122 is in the range of 50PPI P400 PPI, and the helix angle α of the first and second winding

wires

121 and 122 is in the range of 45 DEG α 90 deg.

Preferably, the outer diameter of the catheter 100 is gradually increased from the distal end to the proximal end of the catheter 100, so that the proximal end of the catheter 100 has better support performance and the distal end has better softness.

The catheter 100 is made as follows:

first, the first winding wire 121 and the second winding wire 122 are sequentially spirally wound on the outer surface of the inner layer 110 to form a distal foundation layer and a proximal foundation layer, respectively, and the proximal end of the distal foundation layer and the distal end of the proximal foundation layer are connected to each other. Wherein the first and second winding

wires

121 and 122 can be spirally wound against the inner layer 110.

Before the first and second winding

wires

121 and 122 are spirally wound on the outer surface of the inner layer 110, the first and second winding

wires

121 and 122 may be heat-treated to be set so that the first and second winding

wires

121 and 122 are spirally wound and closely attached to the inner layer 110.

Next, a plurality of strands of LCP filaments are woven into a diamond-shaped lattice structure over the outer surface of the inner layer 110 using weaving means conventional in the art, such as one over one under (as shown in fig. 1, 2 and 3) or two over two under.

Again, the outer layer 130 is sequentially disposed over the outer surface of the distal base layer, over the outer surface of the proximal base layer not covered by the reinforcing layer 123, and over the outer surface of the reinforcing layer 123, even though the outer layer 130 is disposed over the entire outer surface of the middle layer 120.

Finally, after the catheter 100 is positioned in the desired location, the inner layer 110, the proximal base layer, the distal base layer, the reinforcing layer 123, and the outer layer 130 are secured together by a heat shrinking process.

A comparative experiment of the push resistance and the supporting ability of the catheter 100 in which the reinforcing layer 123 is woven using liquid crystal polymer filaments was conducted together with a catheter in which the reinforcing layer does not include liquid crystal polymer filaments (other polymer filaments were used instead), but has the same structure as the catheter 100 in the present embodiment, and it was found that: the catheter 100 including the liquid crystal polymer filaments in the reinforcing layer 123 has a smaller withdrawal distance than the catheter not including the liquid crystal polymer filaments in the reinforcing layer, which indicates that the catheter has better support performance and smaller pushing resistance, and can reach a more distal blood vessel position; with the same inner diameter, the catheter 100 including the liquid crystal polymer filaments in the reinforcing layer 123 has a smaller outer diameter than the catheter not including the liquid crystal polymer filaments in the reinforcing layer; the catheter 100 including the liquid crystal polymer filaments in the reinforcing layer 123 has a higher stiffness than the catheter without the liquid crystal polymer filaments in the reinforcing layer, wherein the difference between the stiffness of the catheter 100 and the stiffness of the catheter is smaller at the distal end and larger at the proximal end, and it can be seen that the application of the liquid crystal polymer filaments in the middle layer of the catheter 100, especially the reinforcing layer, can significantly enhance the stiffness of the catheter 100 at the proximal end while having a smaller effect on the softness at the distal end. The experimental data are shown in the following table:

catheter 100	Ability to be in place	Push resistance (g)
			The reinforcing layer 123 comprises LCP filaments	M2	225.6
LCP filaments are not included in the reinforcement layer 123	M1	362

Catheter 100	Withdrawing distance (mm)
		The reinforcing layer 123 comprises LCP filaments	7
LCP filaments are not included in the reinforcement layer 123	19.4

Among these, the withdrawal distance assesses the ability of the catheter to remain in place while pushing subsequent instruments through the blood vessel, with smaller data being better. I.e., the smaller the pullback distance, the better the support performance.

Example two

The present embodiment provides a catheter 100, and the difference between the present embodiment and the first embodiment is that in the present embodiment, the first winding wire 121 is an LCP wire.

Since the first winding wire 121 is an LCP wire, the distal end of the catheter 100 can have better softness and simultaneously have improved anti-ovality.

In other embodiments, the first and/or second winding

wires

121, 122 are LCP wires, and the woven layer is other wire material; or the second and woven layers may both comprise LCP filaments, but the first winding filament is the other filament material.

When the second winding wire 122 and/or the braided layer are LCP wires, the proximal end of the catheter 100 can have a stronger supporting property, the pushing resistance of the catheter 100 can be reduced, and the distal end positioning ability can be improved.

EXAMPLE III

The present embodiment provides a catheter 100.

Referring to fig. 5, fig. 5 is a partially enlarged schematic view of a catheter in a third embodiment of the present invention, which is different from the first embodiment in that the distal base layer includes two first winding

wires

121a and 121b, the two first winding

wires

121a and 121b are spirally wound in a cocurrent spiral manner from the distal end to the proximal end of the inner layer 110, wherein one first winding wire 121a is an LCP wire, and the other first winding wire 121b is a nitinol wire. The co-rotating helical pattern means that the two first winding wires may be helically wound in the same manner as any two of the multi-start helical patterns, for example, the two first winding wires may be helically wound in a double-start helical pattern, or the two first winding wires may be helically wound in the same manner as any two of the three-start helical or medium multi-start helical patterns.

Because the distal end of the catheter 100 comprises a strand of LCP wire and a strand of Nitinol wire, the properties of the two materials can be fully utilized, and the anti-ovality performance of the distal end of the catheter 100 can be improved while the distal end of the catheter 100 has better softness.

Fig. 6 is a graph comparing the stiffness of a catheter 100 ' of the same construction as the catheter 100 ' of the third embodiment of the present invention, but with the distal base layer comprising only NiTi filaments (not LCP filaments), and fig. 7 is a graph comparing the anti-ovality of the catheter 100 of the third embodiment of the present invention with the catheter 100 ' of the same construction but with the distal base layer comprising only NiTi filaments (not LCP filaments). Referring to fig. 6 and 7, comparative experiments conducted on the catheter 100 in this example with a catheter 100' that did not include liquid crystal polymer filaments in the distal base layer, but was identical in structure to the catheter 100 in this example, revealed that: the catheter 100 with the liquid crystal polymer filaments in the distal base layer has less lumen deformation than the catheter 100' without the liquid crystal polymer filaments in the distal base layer, indicating better ellipse resistance, and the proximal stiffness is significantly higher while the distal softness is nearly the same.

Where the stiffness test is a two point bend test, see fig. 6, where the ordinate is the force used to bend the catheter in N (newtons), with larger data indicating that the catheter 100 is stiffer and the abscissa is the distance from the measurement point to the distal end in cm.

Wherein, the ellipse resistance performance test can measure the deformation condition of the lumen when the distal end of the catheter is bent excessively. Referring to fig. 7, where the ordinate is the change in the outer diameter of the catheter (i.e. the difference between the outer diameter before testing and the outer diameter when the distal end is overbent) in mm, and the abscissa is the distance between the measurement point and the distal end of the catheter in cm x 1.5 (e.g. "3" means 4.5cm from the distal end of the catheter). The specific process for carrying out the ellipse resistance performance test comprises the steps of preparing cylinders with the diameters of 1mm, 3mm, 5mm and the like, placing the cylinders under a microscope, sequentially attaching samples of the two catheters to the cylinders with the same specification in a surrounding manner, measuring the diameter change of the catheters before and after the catheter is attached to the wall, and calculating the change rate of the diameter change, thereby measuring the deformation condition of the lumen when the distal end of the catheter is bent excessively. I.e., the greater the change in conduit diameter, the higher its rate of change, and the poorer the anti-ovality properties. Since the catheter 100' without the LCP wire at overbending was bent (kink) 10.5cm from the distal end, its outer diameter could not be measured, and the value was recorded as "0", while the actual outer diameter rate of change would be 100%.

In other embodiments, the distal base layer may further include three, four or five first winding wires 121, the plurality of first winding wires 121 may be helically wound on the inner layer 110 in a co-rotating manner in a proximal direction along the distal end of the catheter 100, and the plurality of first winding wires 121 may be the same or different in material, wherein at least one first winding wire 121 is an LCP wire, for example, the plurality of first winding wires 121 may be all LCP wires. Of course, the number of strands of the first winding wire 121 in the distal base layer may be other, and is not limited herein.

Example four

The present embodiment provides a catheter 100, and the difference between the present embodiment and the first embodiment is that, in the present embodiment, the strand of first winding wire 121 is a composite wire made of LCP wire and metal wire or non-metal wire.

EXAMPLE five

The present embodiment provides a catheter 100, and the difference between the present embodiment and the first embodiment is that in the present embodiment, the second winding wire 122 is a composite wire made of LCP wire and metal wire or nonmetal wire.

In other embodiments, the catheter 100 can include a plurality of the second winding wires 122, with the plurality of second winding wires 122 being helically wound around the inner layer 110 in a co-current helical manner in a proximal-to-distal direction of the catheter 100. Wherein the second winding wire 122 may be LCP wire, metal wire, non-metal wire, or two or more of the foregoing.

EXAMPLE six

The present embodiment provides a catheter 100, and the difference between the present embodiment and the first embodiment is that in the present embodiment, the braided layer includes a plurality of strands, including at least one LCP strand and one nitinol strand. The braided layer is formed by mixing and braiding LCP wires and nickel-titanium alloy wires. The catheter 100 has better performance due to the different properties of the two wires that combine well.

In other embodiments, the braided layer comprises a plurality of strands of filaments, and each strand of filaments is formed by mixing LCP filaments with metal filaments or other polymer filaments to form composite filaments and is braided from the composite filaments. The metal wire can be a nickel-titanium alloy wire, a 304 stainless steel wire, a copper wire, a silver wire, a platinum-iridium alloy wire and the like, and the polymer wire can be made of PVC, ABS, PLA and the like.

EXAMPLE seven

The present embodiment provides a catheter 100, and the difference between the present embodiment and the first embodiment is that, in the present embodiment, the intermediate layer 120 does not include the reinforcing layer 123 having a tubular shape.

Specifically, in the present embodiment, the catheter 100 includes an inner layer 110, an intermediate layer 120, and an outer layer 130 in sequence from inside to outside along the radial direction of the catheter. The outer layer 130 is disposed over the outer surface of the middle layer 120. Wherein the intermediate layer 120 comprises only a distal base layer in the shape of a tube and a proximal base layer in the shape of a tube. The distal base layer and the proximal base layer are sequentially sleeved on the outer surface of the distal end of the inner layer 110 and the outer surface of the proximal end of the inner layer 100. The outer layer 130 is disposed over the outer surfaces of the distal and proximal base layers.

The distal base layer includes at least one first winding wire 121, and the first winding wire 121 is spirally wound on the outer surface of the inner layer 110 in a direction in which the distal end of the catheter 100 approaches the proximal end of the catheter 100. The distal base layer includes at least one second winding wire 122, and the second winding wire 122 is spirally wound on the outer surface of the inner layer 110 in a direction approaching the proximal end of the catheter 100 from the distal end of the catheter 100. Wherein the proximal end of the first winding wire 121 may or may not be connected to the distal end of the second winding wire 122.

The first winding wire 121 and/or the second winding wire 122 include LCP wires therein. For example, the first winding wire 121 is an LCP wire, and the second winding wire 122 is one of a metal wire, another polymer wire, or a composite wire formed by a metal wire and another polymer wire; alternatively, the second winding wire 122 is an LCP wire, and the first winding wire 121 is one of a metal wire, another polymer wire, or a composite wire formed by a metal wire and another polymer wire; alternatively, the first winding wire 121 and the second winding wire 122 are both LCP wires.

Example eight

The present embodiment provides a conveying apparatus. Referring to fig. 8, fig. 8 is a schematic structural diagram of a conveying device in an eighth embodiment of the present invention, where the conveying device includes: stress diffusion tube 200, connector 300 and catheter 100 of the above embodiments. The distal end of the stress diffusion tube 200 is connected with the proximal end of the catheter 100, the stress diffusion tube 200 is used for preventing the catheter 100 and the connecting piece from being broken, the distal end of the connecting piece 300 is connected with the proximal end of the stress diffusion tube, and the connecting piece 300 is used for being connected with other medical instruments. Wherein the other medical device may be an operating handle, an infusion set, an ablation energy device, or the like.

The transport apparatus further includes a developer ring 400. The visualization ring 400 is sleeved on the distal end of the catheter 100 to ensure that the catheter 100 can be observed during the operation.

The LCP filaments in the above embodiments refer to filamentary materials composed of LCP, wherein LCP is a polymer, which has not been used in the field of medical devices to date. LCP has very high tensile strength and flexural modulus, so it has very good processability, and the resulting product has very good integrity.

It should be noted that, in the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

Additionally, the "proximal" and "distal" in the above embodiments are relative orientations, relative positions, directions of elements or actions with respect to each other from the perspective of a physician using the medical device, although "proximal" and "distal" are not intended to be limiting, but "proximal" generally refers to the end of the medical device that is closer to the physician during normal operation, and "distal" generally refers to the end that is first introduced into the patient. Furthermore, the term "or" in the above embodiments is generally used in the sense of comprising "and/or" unless otherwise explicitly indicated. In the above embodiments, "both ends" refer to the proximal end and the distal end.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.

Claims

1. A catheter, characterized by comprising an inner layer, a middle layer and an outer layer in this order from inside to outside in the radial direction of the catheter, the middle layer comprising a base layer, wherein the middle layer comprises liquid crystal polymer filaments.

2. The catheter of claim 1, wherein the base layer is disposed over the outer surface of the inner layer, the base layer comprising a distal base layer and a proximal base layer in sequence from a distal end to a proximal end along an axial direction of the catheter, the distal base layer comprising at least one first wrap wire and the proximal base layer comprising at least one second wrap wire.

3. The catheter of claim 1 or 2, wherein the intermediate layer further comprises a reinforcement layer disposed over at least a portion of the outer surface of the base layer, the liquid crystal polymer filaments being disposed in the base layer and/or the reinforcement layer.

4. The catheter of claim 3, wherein the reinforcing layer is a braided layer.

5. The catheter of claim 4, wherein said braid comprises a plurality of strands of liquid crystal polymer filaments; or the braided layer comprises at least one strand of liquid crystal polymer filament and at least one strand of metal filament or other high molecular filaments; or the braided layer comprises a plurality of strands of filaments, and each strand of filament is formed by mixing a liquid crystal polymer filament and a metal filament or other high polymer filaments.

6. The catheter of claim 4, wherein said braid is tapered from a distal end to a proximal end.

7. The catheter of claim 2, wherein the distal base layer and/or the proximal base layer comprise liquid crystal polymer filaments.

8. A catheter as in claim 7, wherein a plurality of the first wrap wires are helically wrapped in a co-helical manner around the outer surface of the inner layer in a distal to proximal direction of the catheter and/or a plurality of the second wrap wires are helically wrapped in a co-helical manner around the outer surface of the inner layer in a distal to proximal direction of the catheter.

9. The catheter of claim 8, wherein the distal base layer comprises at least two strands of first wound filaments, wherein at least one strand of the first wound filaments is a liquid crystal polymer filament and at least one strand of the first wound filaments is a metal filament or other polymeric filament; or the distal base layer comprises a plurality of first wound filaments, each of which is a liquid crystal polymer filament.

10. The catheter of claim 8, wherein the proximal base layer comprises at least two strands of second wound wires, wherein at least one strand of the second wound wires is a liquid crystal polymer wire and at least one strand of the second wound wires is a metal wire or other polymeric wire; or the proximal base layer comprises a plurality of second winding wires, each of which is a liquid crystal polymer wire.

11. The catheter of claim 2 or 8, wherein the first winding wire is a round wire and the second winding wire is a flat wire.

12. The catheter of claim 2 or 8, wherein the second winding wire is wound on the outer surface of the inner layer at a variable pitch in a proximal direction along the distal end of the catheter, and the pitch is gradually reduced or stepwise reduced in the proximal direction along the distal end of the catheter.

13. The catheter of claim 3, wherein the reinforcing layer is disposed over at least a portion of an outer surface of the proximal base layer.

14. A delivery device comprising a stress diffusion tube, a visualization ring and a catheter as claimed in any of claims 1 to 13, wherein the distal end of the stress diffusion tube is connected to the proximal end of the catheter and the visualization ring is fitted over the distal end of the catheter.