Lubricating liner inside the catheter tube
By expanding and optionally bonding a lubricating liner to the inner wall of a catheter tube, the method addresses the challenge of reduced contact area and elongation, enhancing stability and reducing friction.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- BENDIT TECH
- Filing Date
- 2024-05-06
- Publication Date
- 2026-06-10
Smart Images
Figure 2026518852000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a lubricious liner for use within a catheter tube, in particular to expanding or joining such a lubricious liner to the inner wall of the tube, in order to reduce friction and facilitate the sliding of an object within the tube.
Background Art
[0002] In many surgical or medical procedures, it is necessary to insert and slide objects such as wires, stents, needles, surgical instruments, embolic capture meshes, etc. into the lumen of a catheter or tube (these terms are used interchangeably). In particular, when the catheter is bent when passing through a particular vascular structure, the frictional force between the object and the inner wall of the catheter can make it difficult to push the object through the lumen.
[0003] In the art, it is known to reduce friction and thereby enable an object to slide more easily within a catheter by inserting a liner made of a lubricious material, such as a fluorocarbon like polytetrafluoroethylene (PTFE), into the catheter to form a low friction surface.
[0004] However, due to the non-stick nature of the lubricious liner, it is difficult to join the lubricious liner to the inner wall of the catheter. Thus, conventional liners have been joined at one or more points of the tube, with the remaining portion of the liner either floating unrestrained or completely floating within the tube.
[0005] When the liner is (partially or fully) floating within the tube and due to assembly constraints, the outer diameter (OD) of the liner is smaller than the inner diameter (ID) of the tube. As a result, the contact area between the liner and the tube is reduced, allowing the liner to move, which can cause elongation of the liner.
Summary of the Invention
[0006] The present invention aims to provide an innovative method for extending a lubricating liner radially outward toward the inner wall of a catheter or tube, and for optionally joining the liner to the tube, as will be described in more detail below.
[0007] In one non-limiting embodiment of the present invention, a portion of the liner is expanded to press against the inner wall of the tube without being joined to the tube, and another portion of the liner is expanded to press against the inner wall of the tube and joined to the tube. For example, in portions of the tube that have slots or other notches so that the tube can bend in various directions, it may be advantageous not to join the liner to the tube. In contrast, in portions of the tube that do not have notches, the liner is joined to the tube. Optionally, the notched portions of the tube may also be joined to the liner as needed.
[0008] Even if the liner is not joined to the tube, it expands and presses against the tube, so the liner's OD becomes the same as the tube's ID, thereby creating a large contact area between the liner and the tube. This reduces or eliminates the elongation of the liner.
[0009] A non-limiting embodiment of the present invention provides a method for incorporating a liner into a tube. This method comprises the steps of: positioning the liner inside the tube; heating a portion of the liner called a heating portion with a local heat source, wherein the heating portion is no more than one-third of the total length of the liner; expanding the heating portion radially outward so that the heating portion contacts the inner wall of the tube; and repeatedly advancing the local heat source longitudinally along a desired length of the liner, thereby expanding the heating portion radially outward so that the heating portion contacts the inner wall of the tube over the desired length.
[0010] According to one non-limiting embodiment of the present invention, the liner is formed of a lubricating material.
[0011] According to one non-limiting embodiment of the present invention, the expanding step is performed using a solid expander introduced into the liner.
[0012] According to one non-limiting embodiment of the present invention, the expanding step is performed using a liquid expander.
[0013] According to one non-limiting embodiment of the present invention, the expansion step is performed using a gas expander.
[0014] According to one non-limiting embodiment of the present invention, the temperature at which the liner is heated is a temperature that softens the liner, but is lower than the melting point of the tube.
[0015] According to one non-limiting embodiment of the present invention, a portion of the liner, called a non-joined expansion portion, is expanded to abut against the inner wall of the tube without being joined to the tube.
[0016] According to one non-limiting embodiment of the present invention, a portion of the liner, called a joining expansion portion, is expanded to abut against the inner wall of the tube, and the tube is joined to the liner.
[0017] According to one non-limiting embodiment of the present invention, the tube is joined to the liner by heating the tube to a temperature above its melting point.
[0018] According to one non-limiting embodiment of the present invention, the non-jointed expansion portion is a portion of the tube provided with a slot or other notch, and the jointed expansion portion is a portion of the tube without a notch. [Brief explanation of the drawing]
[0019] This invention will be more fully understood and grasped by reading the following detailed description in conjunction with the drawings. [Figure 1]Figure 1 is a schematic diagram showing, according to a non-limiting embodiment of the present invention, how a lubricating liner is gradually heated and expanded along its axial direction, pressing the liner against the inner wall of the tube. [Figure 2] Figures 2A, 2B, 2C, and 2D are perspective views, perspective cross-sections, front views, and front cross-sections of a tube incorporating a lubricating liner, respectively, in which a portion of the liner expands to abut against the inner wall of the tube without being joined to the tube, and another portion of the liner expands to abut against the inner wall of the tube and is joined to the tube. [Modes for carrying out the invention]
[0020] Refer to Figure 1 here. It is desirable to incorporate a lubricating liner 10 inside the tube 12. The liner 10 can be formed from a lubricating material such as polytetrafluoroethylene (PTFE) or other fluorocarbons, but is not limited to this. The tube 12 can be formed from a metal or polymer, such as stainless steel, nitinol, titanium alloy, nylon, polyether block amide (PEBA), or other materials, but is not limited to these. Examples of PEBA include the trademarked names PEBAX (manufactured by Arkema) and VESTAMID (manufactured by Evonik Industries). In its initial state, the liner 10 has an OD smaller than the ID of the tube 12.
[0021] Tube 12 may be the outer layer of the tube assembly. In the context of the present invention, it is the layer on which the liner is placed.
[0022] The expander 14 can be used to expand the liner 10 radially outward. The expander 14 can be formed from a polymer such as polyethylene terephthalate (PET), but is not limited to this, and can be formed from other materials. The expander 14 has an OD that is slightly smaller than the ID of the tube 12, and the difference in diameter is the desired final thickness of the liner 10 after radial expansion.
[0023] Alternatively, the expander 14 is a pressurized fluid (liquid or gas) rather than a solid.
[0024] A local heat source 16 such as an induction heating ring, a resistance coil heating ring, a hot air nozzle, a torch, etc. can be used to locally heat a portion of the liner 10 called the heating portion 18. The heating portion 18 is significantly shorter than the full length of the liner 10 (less than 1 / 3 of the full length), for example, 5%, 10%, or 20% of the full length, but is not limited thereto. Put another way, the heating portion 18 may be a length of a few millimeters, or 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 28 mm, 30 mm, 35 mm, 40 mm, or other suitable lengths.
[0025] As shown in FIG. 1, the liner 10 is first placed inside the tube 12. The heating portion 18 is heated by the local heat source 16, and the expander 14 is introduced into the liner 10. The local heat source 16 gradually advances in the longitudinal direction (the direction of arrow 20) and gradually heats the local regions of the liner 10 and the tube 12. In one example, the expander 14 is made of a material that remains stationary within the liner and expands radially outward when it reaches the temperature after being heated by the local heat source 16 (for example, the expander 14 can also be made of a shape memory material). By this expander 14, the lubricious liner 10 expands radially outward, and the heated portion 18 of the expanded liner 10 is pressed against the inner wall of the tube 12. In another example, the expander 14 does not expand outward and does not remain stationary. Instead, it gradually advances in the longitudinal direction (the direction of arrow 20), gradually expands the heated portion 18 of the lubricious liner 10 radially outward, and presses the heated portion 18 of the expanded liner 10 against the inner wall of the tube 12. In the expanded portion, the OD of the liner becomes the same as the ID of the tube.
[0026] This method of gradually heating and expanding is far more effective than heating the long portion of the liner. This is because by gradually expanding the liner, it is possible to prevent the liner 10 from being twisted, wrinkled, or torn.
[0027] The temperature at which the liner is heated by the local heat source 16 is a temperature that softens the liner material to facilitate its expansion, but is lower than the melting point of the tube 12. By way of example only and not limitation, when using a PTFE liner and a PEBA tube, the heating portion 18 is expanded at a pressure of 6 bar and heated to 135°C with a heating nozzle having a width of 28 mm. This nozzle moves linearly at a speed of 1 mm / second in the direction of arrow 20.
[0028] Next, refer to FIGS. 2A, 2B, 2C, and 2D. A portion of the liner 10 (referred to as the non-bonded expansion portion 22) is expanded so as to be pressed against the inner wall of the tube 12 without bonding the tube 12 to the liner 10. Another portion of the liner 10 (referred to as the bonded expansion portion 24) is expanded so as to be pressed against the inner wall of the tube 12, and the tube 12 is bonded to the liner 10. This bonding can be performed at any temperature exceeding the melting point of the tube 12. By way of example only and not limitation, when using a PTFE liner and a PEBA tube, the heating portion 18 is expanded at a pressure of 6 bar and heated to 160°C with a heating nozzle having a width of 28 mm. This nozzle moves linearly at a speed of 1 mm / second in the direction of arrow 20. At the temperature of 160°C, the tube material (in this example, the PEBA material) melts, whereby the tube material is welded (adhered) to the liner material. In another example, the PTFE liner is an inner liner having an outer layer of PEBA, and this multi-layer liner is disposed inside a tube 12 made of another material (for example, nitinol). In this case, at the temperature of 160°C, the outer layer (PEBA) of the liner material melts, whereby the outer layer of the liner material is welded (adhered) to the tube material.
[0029] According to one non-limiting embodiment of the present invention, the non-jointed expansion portion 22 is a region in the tube 12 that has slots or other notches 26 so that the tube 12 can be bent in various directions. This region is subject to significant deformation due to bending of various types and directions, which may cause plastic deformation in the liner 10, potentially weakening, breaking, or rupturing the liner 10. In contrast, the jointed expansion portion 24 is a portion of the tube 12 that does not have notches.
Claims
1. A method of incorporating a liner inside a tube, The steps include: placing the liner inside the tube, A step of heating a portion of the liner, called the heating portion, with a localized heat source, wherein the heating portion is one-third or less of the total length of the liner; The steps include: expanding the heating portion radially outward so that the heating portion contacts the inner wall of the tube; A method characterized by repeatedly advancing the localized heating source longitudinally along a desired length of the liner, thereby expanding the heating portion radially outward so that the heating portion contacts the inner wall of the tube over the desired length.
2. In the method according to claim 1, A method characterized in that the liner is formed of a lubricating material.
3. In the method according to claim 1, A method characterized in that the expansion step is performed using a solid expander introduced into the liner.
4. In the method according to claim 1, A method characterized in that the expansion step is performed using a liquid expander.
5. In the method according to claim 1, A method characterized in that the expansion step is performed using a gas expander.
6. In the method according to claim 1, A method characterized in that the temperature at which the liner is heated is a temperature that softens the liner, but is lower than the melting point of the tube.
7. In the method according to claim 1, A method characterized in that a portion of the liner, called a non-joined expanded portion, is expanded so as to abut against the inner wall of the tube without being joined to the tube.
8. In the method according to claim 1, A method characterized in that a portion of the liner, called a joint expansion portion, is expanded so as to abut against the inner wall of the tube, and the tube is joined to the liner.
9. In the method according to claim 1, A method characterized in that a portion of the liner, called a non-joining expansion portion, is expanded to abut against the inner wall of the tube without being joined to the tube, and another portion of the liner, called a joining expansion portion, is expanded to abut against the inner wall of the tube, and the tube is joined to the liner.
10. In the method described in claim 8, A method characterized in that the tube is joined to the liner by heating the tube to a temperature exceeding its melting point.
11. In the method according to claim 9, A method characterized in that the tube is joined to the liner by heating the tube to a temperature exceeding its melting point.
12. In the method according to claim 9, The method is characterized in that the non-jointed expanded portion is a portion of the tube in which a slot or other notch is provided, and the jointed expanded portion is a portion of the tube without a notch.