Dynamic wall pipe material

Abstract

To provide improved medical devices having tubing useful for such applications as access devices, catheters or introducers, or other such devices intended to provide contact with regions within the body.SOLUTION: Expandable tubing 100 comprises: an outer tube body 102 comprising an expandable material; a structural element 120 positioned helically within a wall of the outer tube body 102, where the structural element 120 is expandable in an axial length such that the expansion of the structural element 120 in the axial direction expands a diameter of the outer tube body 102 in the axial direction. The structural element can be embedded in the wall of the outer tube body 102 through an extrusion or molding process or the like.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] There is still a need for improved medical devices having a tubular member useful for applications such as access instruments, catheters, introducers, or other such instruments intended to contact a site within the body.

Background Art

[0002] For example, such instruments can be provided with a dynamic wall structure that can be easily expanded to allow other medical instruments, components, and / or implants to pass through, and the dynamic wall returns to its normal diameter after the passage of the secondary medical instrument, component, and / or implant.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Such a dynamic wall structure can be provided with an active dynamic wall tubular member, where activation is required for expansion of the tubular member. Alternatively, such a dynamic wall structure can also be of a passive type where the tubular member expands and contracts to accommodate the passage of an instrument through the structure.

Means for Solving the Problems

[0004] The present disclosure includes an expandable tubular member configuration. In one example, the tubular member includes an outer tube body made of an expandable material; and a structural element disposed helically within the wall of the outer tube body, the structural element being axially expandable such that axial expansion of the structural element expands the diameter of the outer tube body.

[0005] In a further variation, the structural element is configured to be pressurized. Variations of the structural element include a coil or blade.

[0006] The structural element can comprise a wire or a polymeric material or a combination of both. In one example, the structural element comprises a co-extrusion of a first polymer and a second polymer, whereby the second portion of the structural element can have structural properties different from the other portions of the portion. Such properties include hardness, elasticity, degree of stretchability, etc.

[0007] In a further variant, the structural element is in a curved configuration in the non-expanded shape and becomes linear when expanded.

[0008] In a further variant, the structural element comprises a series of spring materials that form a zigzag or undulating configuration when arranged helically within the wall of the outer tube body. Such a configuration includes a nested configuration.

[0009] In a further variant, the outer tube body consists of a tube material and a second material co-extruded with the tube material. In such a configuration, when the outer tube body expands, the second material stretches significantly more than the tube material. The outer tube can have any number of portions of the second material.

[0010] In any of the variants, the expandable pipe can have an expandable tip configuration.

Brief Description of the Drawings

[0011]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

Figure 3F

Figure 3G

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 5A

Figure 5B

Figure 5C

DETAILED DESCRIPTION OF THE INVENTION

[0012] The following description discloses various embodiments and examples of the apparatus and method according to the present disclosure. Combinations of aspects of the various apparatus and methods, or combinations of the apparatus and methods themselves, are considered to be within the scope of the present disclosure.

[0013] FIG. 1A shows an example of an expandable tube configuration 100 comprising an outer tube body 102 having a wall of thickness T1 and a lumen 104 of diameter d1. The tube body 102 is formed from an expandable polymeric material with a structural element 120 disposed therein. The structural element 120 functions to assist the outer tube body 102 in expanding when an oversized instrument (not shown) passes through the lumen. The structural element can be embedded in the wall of the tube body 102 by, for example, an extrusion or molding process. Alternatively, the structural element 20 can be disposed within a path extending within the wall of the tube body 102.

[0014] In the variant illustrated in FIG. 1A, the structural element 120 has a waveform, zigzag or reciprocating shape as shown in FIG. 1C. Here, as a function of the shape, the overall length 126 of the element 120 may contract, or may increase up to a length 130 as shown in FIG. 1D by the operation of the structural element 120. In a particular variant, the length of each section 128 is also the extended length 130. In a further variant, the structural element 120 can expand elastically along the length 126 to increase the length 130. In the illustrated variant, the structural element 120 can comprise an elastic structure that can be pressurized from a reference pressure P0 to an elevated pressure P1, where the elevated pressure causes the structural element to straighten from the length 126 to 130. It is clear that alternative ways of expanding the length are within the scope of the variants of the present disclosure. For example, the structural element can be composed of a shape memory alloy that is activated by heat or energy to expand from a natural length 126 to an expanded length 130. Further, the structural element 120 can have a variety of shape configurations other than zigzag, waveform or reciprocating shapes as long as the length can be increased as required.

[0015] Figure 1A shows the state of the expandable tube 100 when the structural element 120 is in its natural or unextended state. The illustrated variant shows the expansion tube 106 connected to the structural element 122. At either end of the structural element 122, any number of valves and / or plugs 124 can be used.

[0016] In an alternative variant of the instrument, an expansion tube that is part of the structural element 122 is provided. In the initial state, at pressure P0, the structural element 122 remains in a relaxed state where the diameter of the inner cavity 104 remains at d1. If desired, the pressure increases within the expansion tube 106 and / or the structural element 120 such that it is represented by P1. This increase in pressure enables the structural element 120 to extend from its initial state (shown in Figure 1C) to its extended or expanded state (shown in Figure 1D). The corresponding change in the length of the structural element 120 from 126 to 130 acts on the tube body 120 and d increases the diameter of the inner cavity 104 to 2. In a particular variant, the wall thickness T1 of the tube body 102 in its natural state remains equal or approximately equal to the wall thickness T2 in the expanded state. In an alternative variant, an instrument is provided where the thickness varies between the expanded and unexpanded states.

[0017] Figure 1B shows how the expansion of the structural element 122 drives the expansion of the expandable tube 102. As described above, this variant is considered to be an actively expandable tube 100 that operates by applying stress to compress the zigzag structural element 120 to expand the diameter of the tube body 102 and enable passage of oversized instruments through the inner cavity. When pressurized, the structural element 120 becomes straight, expands in diameter and increases its circumferential length, while the wall thickness T2 remains equal or approximately equal to the unexpanded wall thickness T1 of the unexpanded tube 100.

[0018] In a further variant of the instrument 100, a plurality of structural elements 120 are provided that are disposed within the wall of the expandable tube 102. Also, one or more structural elements 120 can be disposed within or in the vicinity of the tube 102 if desired.

[0019] Figures 2A - 2C show another variant of the structural element 120 used in the instrument 100 with a dynamic wall tube. In this variant, as shown in Figure 2A, the structural element 120 is linear and includes a coil or blade 132 installed within the expandable backing 134. In the natural state, as shown in Figure 2A, the backing 134 is under a first pressure P1 corresponding to a first length 126. When pressurized up to P2, the backing and the coil expand to a length 130. When the pressure returns to P1, the coil 132 and the backing 134 return to the state shown in Figure 2A.

[0020] Figure 2C shows a cut - out portion of the dynamic wall tube 100. As shown, the structural element of Figure 2A is arranged spirally within the wall of the tube body 102. When the structural element is pressurized via the port 106, the structural element 120 expands in length (as shown in Figure 2B), and the dynamic wall tube 100 expands to the configuration shown in Figure 2C. Again, the diameter of the inner cavity 104 within the tube 100 can increase from d1 to d2 or any range therebetween. When the pressure within the structural element 120 is reduced, the dynamic wall tube 100 can return to the state shown in Figure 2C.

[0021] Figures 3A - 3G show another variant of the structural element 120 for use in the dynamic wall tube 100. Figures 3A and 3B show a structural element including a first polymer 140 and a second polymer 142, where the first and second polymers 140 and 142 have different structural properties such as hardness, elasticity, etc. In the illustrated example, as shown in an alternative configuration of the structural element described herein, the structural element 120 can be configured to seal one or both ends of, for example, the inner cavity 138 and be pressurized using an expansion member 106 (as shown in Figure 3C). In such a configuration, at a reference pressure P0, due to the different structural properties of the first and second polymers 140 and 142, the structural element assumes the configuration of Figure 3B, for example, a curved configuration. When the element 120 is pressurized to P1, the structural element becomes linear as shown in Figure 3A. Figure 3C shows a configuration with P0 on the left and P1 on the right, and the structural element 120 transitions from a reduced length L0 to an expanded length L1.

[0022] As shown in FIG. 3C, the second polymer 142 can be arranged at intervals along the length of the structural element 120. In the illustrated modification, the second polymer 142 is installed on the opposing circumferential side surfaces of the structural element 120. However, alternative modifications such as helical winding in the opposite direction, a plurality of bands along the structural element, etc. are within the scope of the present disclosure. The modification shown in FIG. 3C shows the second polymer 142 forming two arc shapes that create a complete waveform structure at P0. Alternative modifications such as bands are within the scope of the present disclosure. The modification shown in FIG. 3C shows the second polymer 142 forming two arc shapes that create a complete waveform structure at P0.

[0023] In FIGS. 3A - 3C, the second polymer 142 comprises a low modulus band, and each pair of opposing bands is arranged to be placed in the concave portion (the inner part of the curve) of the waveform. When the structural element 120 is pressurized, the stripes are stretched into a straight line due to the anisotropic elastic modulus characteristics of the spaced-apart double-material tubing. One end of the helically wound and spaced-apart striped waveform tubing is sealed. The other end has an extension line 106 with a port for attachment to a pressure source. In a medical application, the port can be a Luer fitting, and the pressure source can be a syringe or other inflation device.

[0024] FIG. 3D shows a structural element 120 having a reinforcing element 148 connected to the structural element 120 (in this modification, the reinforcing element 148 is inside the structural element 120). Such a configuration improves the torsional resistance, hoop strength, buckling strength, pressure resistance, torque transmission, burst strength, and pushability of the structural member 120. The reinforcing element 148 can be made of metal or polymer and can be in the form of a rigid or superelastic single solid, a multi-strand cable or fiber bundle, or the shape of stainless steel or nitinol.

[0025] FIG. 3E shows a structural element 120 connected to the tube body 102, and the structural element 120 is wound in a waveform pattern and continuously wound in a helical pattern around the circumference C0 of the tube body 102 so that the inner diameter of the expandable tube 100 becomes d0.

[0026] In a further modification, the above-described striped structural element can be crosslinked so as not to melt during the heat fusion process used to form the structure. The amount of crosslinking can be controlled in a subsequent crosslinking initiation process, such as exposure to UV energy, electron beam, gamma rays, X-rays, microwaves or other radiation sources. A crosslinking initiator can be compounded into the pipe resin prior to the coextrusion process used to manufacture the dual durometer pipe. The amount or type of crosslinking initiator can be varied in the compounding step to vary the degree of crosslinking when exposed to crosslinking energy.

[0027] The pipe material in the form of stripes at intervals can be composed of a material with a higher melting point than the materials used for the backing and jacket of the resulting structure, so crosslinking of the structure is not a prerequisite for heat-fusing the wound pipe. Since the jacket material does not need to be chemically bonded to the structural elements in the form of stripes at intervals, for example, the jacket and / or backing can be composed of polyurethane, silicone or other elastomers, and the striped pipe can be composed of PEBA resin, polyethylene, PET or other thermoplastic plastics.

[0028] Figure 3F shows that the pressure has increased to P1 within the structural element 120 and the diameter of the expandable pipe 100 has increased to d1. As described herein, the inner diameter d1 of the resulting structure 100 expands when pressure is applied to the wound and peeled pipe, resulting in an increase in the pressurized circumference C1. Although only one structural element 120 is shown in Figure 3C, the number of structural elements 120 used along the axis of the pipe 102 can be arbitrary. In a particular modification, a plurality of structural elements can be wound around the pipe 102. In a particular modification, the outer diameter and number of the wound structural elements determine the twist angle. Further, the continuous structural element 120 can be wound along the axis of the pipe 102.

[0029] Figure 3G shows a modified example of the expandable pipe material 100 configured as described in this specification. Figure 3G shows a structural element 120 (or multiple structural elements) wound around the pipe 102. Subsequently, the wound pipe can be covered with a polymer layer or backing 11 0. Alternatively, or in combination, the structural element 120 and the internal pipe material 102 can be joined to each other along the contact surface. The pipe material 100 may have a square or rectangular cross-section instead of the circular cross-section as shown. Also, a backing may be provided on the inner surface of the structure that expands when pressurized to increase the diameter. This backing may be formed from a thin and smooth material such as PTFE or other more elastic polymers, and a coating agent may or may not be applied to the inner surface. For the fusion of the wound pipe material with the backing and the jacket, thermal processing such as lamination, laser processing, ultrasonic, electromagnetic induction, or radio frequency joining can be performed. Welding may be performed with or without the use of external processing aids such as removable heat-shrinkable pipe materials or internal processing aids such as removable mandrels.

[0030] In a further modified example, the fusion of the structural element 120 wound around the pipe material 102 and the backing 110 can be achieved by a liquid dispersion process such as immersion in a solution of a solvated polymer and evaporation of the solvent. The resulting pipe structure 100 can be configured with a tapered tip for insertion into a blood vessel or fitting with an expander or occluder, or it can have a balloon installed at the tip of the outer surface, providing a holding force resistant to tensile loads, or a seal for vacuum, pressure, or fluid or gas transportation. In addition to or alone, the balloon on the outer surface, the balloon may be attached to the inner surface at a partial length at one end of the structure to provide a seal for any of vacuum, pressure, or fluid or gas transportation.

[0031] Figure 4A shows a further modification of the passive dynamic wall tube 160. As shown, the dynamic wall tube 160 includes a series of spring materials 164 such as wires. In this modification, the spring material 164 includes nested wires wound in a zigzag pattern within the body of the tube material 160. The properties of the spring material 164 can be made consistent or varied throughout the tube material. Further, the amplitude of the spring material 164, the pitch of the wire, the number of turns, and other material parameters can be adjusted as needed throughout the length of the tube material 160. The dynamic tube material also includes one or more regions of a second material 166 that extends into the tube material and has structural properties different from other portions of the tube material 162. For example, it is possible to incorporate HDPE / LDPE or a mixture thereof into the tube material 162. It is possible to incorporate a low flexural modulus material such as PolyBlend45A material into the strip material 166.

[0032] Figure 4B shows a cross-sectional view taken along line 4B-4B of Figure 4A. As shown, the tube material 162 and the secondary material 166 can be co-extruded around or over the reinforcing spring material 164. The spring material 164 is constrained in an expanded state when extruded or formed within the tube material 162 and the second material 162. Since the spring material 164 is constrained by the tube material 162 and the secondary material 166, the spring material 164 reduces the force for expanding the dynamic wall tube 160 when an instrument is placed therethrough. In other words, when the dynamic wall tube material expands as an instrument passes through it, the spring material 164 tries to return to its expanded state, thereby reducing the force for expanding the dynamic wall tube material and reducing the force for the instrument to advance within the dynamic wall tube material. However, when the instrument within the dynamic wall tube material 160 is removed, the tube material 162 and the secondary material 166 again constrain the spring material 164 and return to the natural state shown in Figure 4A.

[0033] Figure 4C shows the dynamic wall tube member 160 of FIGS. 4A and 4B and illustrates a radial force RF representing passage of an instrument through the lumen of the dynamic wall tube member 160. In certain variations, the radial force RF causes a secondary material 166 that is more elastic than the tube material 162 to stretch. As shown, expansion of the secondary material 166 causes a deflection of amount D in the wall thickness of the secondary material 166 while the thickness of the wall tube member 162 remains substantially unchanged. As noted above, the stored energy of the nested coil 164 functions to reduce the amount of radial force RF required to expand the dynamic wall tube member 160 in the region of the secondary material 166. The expansion and deflection of the secondary material 166 also serves to reduce the contact surface area between the dynamic wall tube and the instrument advancing therethrough, further reducing the amount of force required for the instrument to advance through the dynamic wall tube 260. Reduce the amount of force required for the instrument to advance through.

[0034] Figure 4D shows another variation of the dynamic wall tube member 160. In this variation, the secondary material 166 extends in a helical configuration around the tube member 160.

[0035] Figure 5A shows another variation of a dynamic wall tube configured to have an expandable tip. As shown, the tip of the tube 180 includes a first material 184, typically a low hardness material (e.g., 40A), and has a lumen 178 that extends therethrough and terminates at the tip. A second material 182 of higher hardness (e.g., greater than 80A) is disposed adjacent to the first material 184. Next, a highly elastic material 186 is disposed adjacent to the second material 182. To expand the tip, the mechanism 202 extends the first material 184. Since the second material 182 is difficult to stretch, the highly elastic material 186 stretches and expands the materials 184 and 182 outwardly, expanding the tip as indicated by arrow 190.

[0036] FIG. 5B shows an example of a mechanism for expanding the expandable tip catheter shown in FIG. 5A. In this example, the mechanism 202 is provided with a thin-walled pressure tube that can be expanded in the longitudinal direction. In a further variant, when the tube is disposed within the lumen 178, it is not limited to longitudinal expansion, but effectively expands to produce a distal force at the tip of the catheter 180. As shown, the tube includes a non-expanded portion 205 adjacent to the expanded portion 204. For example, the expanded portion 204 can have spiral folds in the wall of the tube, such that when the tube 202 is pressurized from P1 to P2, the length of the expanded portion 204 increases from L1 to L2. In one variant, the non-expanded portion 206 of the tube 202 is fixed within the lumen 178 of the first material 184, such that the tip moves outwardly due to the elongation of the expanded portion 204.

Claims

1. An expandable pipe (100), comprising: An outer pipe body (102) made of an expandable material and having a first inner cavity (104); A structural element (120) including a coil or blade (132) and a second inner cavity, wherein the coil or blade (132) is installed in a backing (134) that is expandable; The coil or blade (132), the backing (134), and the second inner cavity of the structural element (120) are spirally embedded in the wall of the outer pipe body (102), The second inner cavity is configured such that by increasing the pressure in the second inner cavity from a first pressure (P0) to a second pressure (P1), the coil or blade (132) and the backing (134) expand from a first length (126) to a second length (130) of the structural element (120) within the wall of the outer pipe body (102); The change in the length of the coil or blade (132) and the backing (134) from the first length (126) to the second length (130) of the structural element (120) acts on the outer pipe body (102) to expand the diameter of the first inner cavity (104) from a first diameter (d1) to a second diameter (d2). An expandable pipe (100) characterized by the above.

2. The expandable pipe according to claim 1, wherein the wall has a wall thickness, the second inner cavity has a second wall thickness, and the second wall thickness is smaller than the wall thickness.

3. The expandable pipe according to claim 1, wherein the coil or blade (132) and the second inner cavity are longer when the outer pipe body (102) is in the expanded form than when the outer pipe body (102) is in the unexpanded form.

4. The expandable pipe according to claim 1, wherein the blade (132) includes a tubular blade.

5. The expandable pipe material according to claim 4, wherein the tubular blade is expandable in the major axis direction and contractible in the major axis direction within the wall of the outer pipe body (102).

6. The expandable pipe material according to claim 4, wherein the tubular blade is expandable in the major axis direction within the wall of the outer pipe body (102) by the expansion of the second inner cavity.

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