Catheter tip with high bond strength

Abstract

A catheter (100) includes an elongate tubular shaft (112) having a distal end (116), a proximal end, and a lumen extending therethrough. The elongate tubular shaft includes a polymeric outer layer (132), a polymeric inner layer (136), and a woven intermediate layer (130). A marking tape (120) is located near the distal end of the elongate tubular shaft and around the intermediate layer, and a polymeric distal tip (140) is attached to the distal end of the elongate tubular shaft. The distal end of the outer layer (133) terminates proximal to the marking tape such that the intermediate layer includes an exposed region exposed from the outer layer between the distal end of the outer layer and the proximal end of the marking tape, and a distal tip is formed on the exposed region of the intermediate layer and the marking tape and extends distally beyond the distal end of the elongate tubular shaft.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 435,057, filed December 23, 2022, which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to catheters and related accessories for delivering therapeutic agents or devices to sites within body cavities. More particularly, the present disclosure relates to catheter tips having high bond strength. Background Art

[0004] A variety of intravascular catheters are known, including small diameter catheters with a central lumen extending therethrough, which are configured for use in smaller vasculature. Such catheters are referred to as microcatheters. Catheters and microcatheters typically include a non-invasive distal tip without a metal reinforcement. The distal tip is separately bonded to the distal end of a catheter shaft, thereby forming a butt joint. The problem with butt joints is that the bond between the distal tip and the catheter shaft is weak, inconsistent, and has a low extension at break. There remains a need for improved catheter distal tips and bonding methods.

[0005] There is a continuing need to provide alternative medical devices and alternative methods of making and using medical devices. Summary of the Invention

[0006] The present disclosure provides design, material, manufacturing method and use alternatives for medical devices. An exemplary medical device may include a catheter. The catheter may include a slender tubular shaft having a distal end, a proximal end and a lumen extending therethrough. The slender tubular shaft may include a polymer outer layer, a polymer inner layer and a braided intermediate layer located between the inner layer and the outer layer. The marker band may be located near the distal end of the slender tubular shaft and surround the intermediate layer. A polymer distal tip may be attached to the distal end of the slender tubular shaft. The distal end of the outer layer may terminate proximal to the marker band, such that the intermediate layer includes an exposed area exposed from the outer layer between the distal end of the outer layer and the proximal end of the marker band, and the distal tip may be formed on the exposed area of ​​the intermediate layer and the marker band and extend distally beyond the distal end of the slender tubular shaft.

[0007] As an alternative or in addition to any of the above embodiments, the outer layer can terminate at a distance within a range of about 0.5 millimeters (mm) to about 1.5 mm proximal to the marker band.

[0008] Alternatively or additionally to any of the above embodiments, the distal tip can provide a tensile strength in the range of 1.42 Newtons (N) to 1.55 Newtons.

[0009] Alternatively or additionally to any of the above embodiments, the distal tip can provide a tensile strength of approximately 1.5 Newtons.

[0010] As an alternative or in addition to any of the above embodiments, the distal tip can be formed from a polyether block amide copolymer.

[0011] As an alternative or in addition to any of the above embodiments, the proximal portion of the distal tip can surround and overlap the distal portion of the outer layer.

[0012] As an alternative or in addition to any of the above embodiments, the distal tip can be formed from a coextrusion comprising a first polyether block amide copolymer layer and a second polyether block amide copolymer layer surrounding the first polyether block amide copolymer layer.

[0013] As an alternative or addition to any of the above embodiments, the radial thickness ratio of the first polyether block amide copolymer layer to the second polyether block amide copolymer layer can be about 1:1.

[0014] As an alternative or addition to any of the above embodiments, a radial thickness ratio of the first polyether block amide copolymer layer to the second polyether block amide copolymer layer can be about 1:1.4.

[0015] A method of forming a catheter having a distal tip may include: disposing a braided intermediate layer on a polymeric inner layer; positioning a marker band on the braided intermediate layer; and extruding a polymeric outer layer onto a proximal region of the braided intermediate layer while exposing a distal region of the braided intermediate layer from the outer layer. The exposed distal region of the braided intermediate layer may extend between a distal end of the outer layer and a proximal end of the marker band. The method may also include cutting a portion of the braided intermediate layer and the inner layer that extends distally of the distal end of the marker band. Thereafter, the method may include extruding a distal tip onto the exposed distal region of the braided intermediate layer and the marker band. The distal tip may extend distally beyond the distal end of the marker band.

[0016] As an alternative or in addition to any of the above embodiments, the distal tip can be formed from a coextrusion comprising a first polyether block amide copolymer layer and a second polyether block amide copolymer layer surrounding the first polyether block amide copolymer layer.

[0017] As an alternative or in addition to any of the above embodiments, the distal tip can be bonded to the inner layer between a plurality of gaps in the exposed distal region of the intermediate layer.

[0018] Alternatively or additionally to any of the above embodiments, the distal tip can provide a tensile strength in the range of 1.42 Newtons (N) to 1.55 Newtons.

[0019] As an alternative or in addition to any of the above embodiments, the outer layer can terminate at a distance within a range of about 0.5 millimeters (mm) to about 1.5 mm proximal to the marker band.

[0020] As an alternative or in addition to any of the above embodiments, the outer diameter of the distal region of the outer layer may taper distally.

[0021] As an alternative or in addition to any of the above embodiments, the proximal portion of the distal tip can surround and overlap the distal region of the outer layer.

[0022] In another example, a catheter may include an elongated tubular shaft having a distal end, a proximal end, and a lumen extending therethrough. The elongated tubular shaft includes a polymer inner layer having an inner surface defining the lumen of the elongated tubular shaft. The inner layer extends continuously from the proximal end of the elongated tubular shaft to the distal end of the tubular shaft. A braided intermediate layer surrounds the inner layer. The intermediate layer extends continuously from the proximal end of the elongated tubular shaft to the distal end of the elongated tubular shaft. A polymer outer layer surrounds the intermediate layer. The outer layer extends continuously from the proximal end of the elongated tubular shaft to a distal end of the outer layer proximal to the distal end of the elongated tubular shaft, such that the intermediate layer includes a distal region extending distally of the distal end of the outer layer. A polymer distal tip may be extruded over the distal region of the intermediate layer and extend distally beyond the distal end of the elongated tubular shaft.

[0023] As an alternative or in addition to any of the above embodiments, the proximal portion of the distal tip can surround and overlap the distal portion of the outer layer.

[0024] As an alternative or in addition to any of the above embodiments, the outer diameter of the distal portion of the outer layer may taper distally.

[0025] As an alternative or in addition to any of the above embodiments, the marker band can be positioned proximate the distal end of the elongated tubular shaft and surrounding the intermediate layer, wherein the distal tip can extend onto and surrounding the marker band.

[0026] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present disclosure may be more fully understood by reading the following detailed description in conjunction with the accompanying drawings:

[0028] Figure 1 is a plan view of a catheter according to an embodiment of the present disclosure;

[0029] Figure 2 is a side view of the distal end of the catheter;

[0030] Figure 2A yes Figure 2 A longitudinal cross-sectional view of the distal end of the catheter along line 2A-2A;

[0031] Figure 2B yes Figure 2A An enlarged view of the exposed area shown in the middle circle 2B;

[0032] Figure 3is a transverse cross-sectional view of an exemplary distal tip of a catheter;

[0033] Figure 3A yes Figure 3 an enlarged cross-sectional view of the wall of the distal tip of the middle catheter;

[0034] Figure 4 is a transverse cross-sectional view of an exemplary distal tip of a catheter;

[0035] Figure 4A yes Figure 4 an enlarged cross-sectional view of the distal tip of the middle catheter;

[0036] 5A to 5D An exemplary method of forming a catheter having a distal tip is shown;

[0037] Figure 6 is an exemplary chart illustrating a distal outer diameter profile of a catheter formed in accordance with the present disclosure;

[0038] Figure 7 is an exemplary graph comparing the tensile force of conduits having butt joints and lap joints formed according to the present disclosure;

[0039] Figure 8 is an exemplary graph comparing the tensile elongation of conduits having butt joints and lap joints formed according to the present disclosure.

[0040] While the present disclosure is susceptible to various modifications and alternative forms, specific details have been shown by way of example in the drawings and will be described in detail. However, it should be understood that it is not intended to limit the present disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure. DETAILED DESCRIPTION

[0041] For the terms defined below, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification. All numerical values ​​herein are assumed to be modified by the term "about", whether or not explicitly stated. The term "about" generally refers to a range of values ​​that one skilled in the art would consider equivalent to the cited value (i.e., having the same function or result). In many cases, the term "about" may include values ​​rounded to the nearest significant figure.

[0042] Numerical ranges recited by endpoints include all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). In this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. In this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0043] It should be noted that references in this specification to "one embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiments may include one or more particular features, structures, and / or characteristics. However, such references do not necessarily mean that all embodiments include the particular features, structures, and / or characteristics. Furthermore, when particular features, structures, and / or characteristics are described in conjunction with one embodiment, it should be understood that such features, structures, and / or characteristics may also be used in conjunction with other embodiments, regardless of whether such features, structures, and / or characteristics are explicitly described, unless expressly stated to the contrary.

[0044] The following detailed description should be read in conjunction with the accompanying drawings, in which similar elements in different drawings are numbered the same. The accompanying drawings, which are not necessarily drawn to scale, depict exemplary embodiments and are not intended to limit the scope of the claims.

[0045] Catheters (eg, microcatheters) can be used to access various areas of the vasculature and other body cavities. For example, some catheters are configured for a variety of treatments, such as diagnosis of vascular complications, delivery of embolic therapies, delivery of medical devices, and intravascular mapping. Figure 1 is an example of such a catheter 10. Figure 1 As shown, the catheter 10 may include an elongated tubular shaft 12 having a distal end 16 and a proximal end 14. The catheter 10 may include a hub 18 fixed to the proximal end 14 of the elongated tubular shaft 12. The catheter shaft 12 of the catheter 10 may have any desired length and outer diameter. For example, the length of the catheter shaft 12 may be in the range of about 50 to about 200 centimeters, and the outer diameter (OD) may be less than, for example, 3 French. In some cases, the outer diameter of the catheter shaft 12 may be 1.7 French or less, 2 French or less, 2.5 French or less, 2.8 French or less, or any other suitable outer diameter. In some cases, the outer diameter of the catheter shaft 12 may be greater than 3 French. For example, the outer diameter of the catheter shaft 12 may be in the range of about 3 French to 10 French or more. In some cases, the catheter shaft 12 may have an outer diameter of about 2.6 French along the distal region and an outer diameter of about 2.8 French along the proximal region. In some cases, the inner diameter (ID) of the catheter shaft 12 can be set to accommodate, for example, a 0.014-inch guidewire, a 0.018-inch guidewire, or a 0.035-inch guidewire. For example, the inner diameter can be, for example, about 0.015 inches to about 0.017 inches, about 0.019 inches to about 0.022 inches, or about 0.034 inches to about 0.038 inches. In other cases, the inner diameter of the catheter 10 can be about 0.015 inches, about 0.019 inches, about 0.036 inches, or any other suitable inner diameter. These dimensions can vary depending on the specific application.

[0046] In some cases, the distal tip 19 can be attached to and extend distally of the distal end 16 of the elongated tubular shaft 12. The distal tip 19 can be a polymeric distal tip 19, which can be made of an elastomer (e.g., ), thermoplastic polymer or any other suitable polymer. The distal tip 19 can be formed of a material that is softer (i.e., lower hardness) than the rest of the elongated shaft 12 of the catheter 10, for example, by using a polymer or elastomer with a Shore hardness of less than 40D. In some cases, the distal tip 19 can be formed of a polymer with a Shore hardness of approximately 35D or less. In some cases, the length of the distal tip 19 can be, for example, from about 1 millimeter (mm) to about 2 mm, or from about 1 mm to about 5 mm. In some cases, the length of the distal tip 19 can be about 2.0 mm, about 1.7 mm, about 1.5 mm, about 1.3 mm, about 1.0 mm, or any other suitable length. The outer diameter of the distal tip 19 can be set to match the outer diameter of the catheter shaft 12 proximal to the distal tip 19. In some cases, the outer diameter of the distal tip 19 can be 1.7 French or less, 2 French or less, 2.5 French or less, 2.8 French or less, or any other suitable diameter. In some examples, the elongated shaft 12 may vary in stiffness along its length. For example, the elongated shaft 12 may include multiple segments having different stiffnesses, such as using different stiffnesses. (For example, the durometer is 75D to 63D to 55D to 45D along the elongated shaft 12 from proximal to distal and then to the distal tip.) These are examples only.

[0047] Figure 2 is a side view of the distal end region of the elongated tubular shaft 112 of the catheter 100, Figure 2A yes Figure 2 A longitudinal cross-sectional view of the distal end region of the elongated tubular shaft 112 of the middle catheter 100 along line 2A-2A, Figure 2B It is taken from Figure 2A The elongated tubular shaft 112 may be an enlarged view of a portion of the elongated tubular shaft 112. Figure 1 An example of an elongated tubular shaft 12 is shown. The elongated tubular shaft 112 may include an outer layer 132, an inner layer 136, and an intermediate layer 130 located between the outer layer 132 and the inner layer 136. The elongated tubular shaft 112 may include a lumen 115 extending therethrough. The lumen 115 may be considered a guidewire lumen and an injection lumen, among others. For example, in use, a practitioner may insert a catheter (e.g., catheter 10) along a guidewire (not shown). Once the target vessel is reached, the guidewire may be removed and a fluid may be injected at the target site through the lumen 115. In some cases, the inner layer 136 may include an inner surface 138 that defines the lumen 115 of the elongated tubular shaft 112.

[0048] The inner layer 136 of the elongated tubular shaft 112 can be a polymeric inner layer and can be formed from or include a coating of a material having a suitable low coefficient of friction. Examples of suitable materials can include polymers such as polytetrafluoroethylene (PTFE). The inner layer 136 can be sized to define the lumen 115 with an appropriate inner diameter suitable for its intended use. In some cases, the inner layer 136 can define a lumen 115 having an inner diameter in the range of, for example, about 0.015 inches to about 0.040 inches. The inner layer 136 can extend continuously from the proximal end (e.g., proximal end 14) of the elongated tubular shaft 112 to the distal end 116 of the elongated tubular shaft 112.

[0049] The outer layer 132 of the elongated tubular shaft 112 can be a polymeric outer layer and can be formed from a polymer that provides the desired flexibility and strength. In some cases, the outer layer 132 can be formed from a nylon polymer, a thermoplastic polymer, an elastomeric polyamide, or any other suitable polymer. The outer layer 132 can be sized to define the outer diameter of the elongated tubular shaft 112. In some cases, the outer diameter of the elongated tubular shaft 112 can be, for example, less than 3 French. In some cases, the outer diameter of the outer layer 132 can be 1.7 French or less, 2 French or less, 2.5 French or less, 2.8 French or less, or any other suitable outer diameter. The outer layer 132 may surround the middle layer 130 and may extend continuously from the proximal end (e.g., proximal end 14) of the slender tubular shaft 112 to the distal end 133 of the outer layer 132, which is located proximal to the distal end 116 of the slender tubular shaft 112, so that the middle layer 130 includes an exposed distal region 131 (generally referred to herein as the exposed region 131) extending distally of the distal end 133 of the outer layer 132.

[0050] The intermediate layer 130 may be radially located between the outer layer 132 and the inner layer 136 and may be formed of a reinforcement structure, such as a braid or a coil. The intermediate layer 130 may be considered a reinforcement layer that increases the torque response of the elongated tubular shaft 112. The intermediate layer 130 or its filaments may be formed of any suitable material, such as stainless steel, tungsten, gold, titanium, silver, copper, platinum, or nitinol. In some cases, the intermediate layer 130 may be formed of a non-metallic material, such as polymer fiber, glass fiber, or liquid crystal polymer (LCP) fiber. When provided as a braided reinforcement layer, the intermediate layer 130 may be formed using a variety of different braid patterns, such as a one-over-one-under pattern, a two-over-two-under pattern, a three-over-three-under pattern, a four-over-four-under pattern, and the like. In some cases, the intermediate layer 130 may be formed using a two-over-two-under configuration, wherein each filament extends over two crossing filaments, then extends under the next two crossing filaments, then extends over the next two crossing filaments, and so on. The intermediate layer 130 may surround the inner layer 136 and may extend continuously from the proximal end (eg, proximal end 14 ) of the elongated tubular shaft 112 to the distal end 116 of the elongated tubular shaft 112 .

[0051] In some cases, the marker band 120 can be located near the distal end 116 of the elongated tubular shaft 112 and can surround the intermediate layer 130, such as Figure 2A As shown. The distal end of the marker band 120 can be substantially aligned with the distal end 116 of the elongated tubular shaft 112. In some cases, the marker band 120 can be formed of a radiopaque material, such as gold, tungsten, a tungsten-filled polymer, etc., to facilitate visibility under fluoroscopy. In some cases, the outer diameter of the outer layer 132 can taper distally at its distal end 133. In other words, the distal region of the outer layer 132 can taper radially inward in the distal direction to the distal end 133 of the outer layer 132. Thus, the outer layer 132 can terminate proximal to the marker band 120, such that the distal end 133 of the outer layer 132 can terminate a distance proximal to the marker band 120. For example, in some cases, the outer layer 132 can terminate proximal to the marker band 120 within a range of approximately 0.5 millimeters (mm) to approximately 1.5 mm, or within a range of approximately 0.5 mm to approximately 3 mm. In some cases, when outer layer 132 terminates proximal to marker band 120, middle layer 130 can include an exposed area 131 that emerges from outer layer 132 between distal end 133 of outer layer 132 and proximal end 122 of marker band 120. In other words, middle layer 130 extends distally beyond distal end 133 of the outer layer such that outer layer 132 does not surround or extend over exposed area 131 of middle layer 130.

[0052] The distal tip 140 can be fixed to the distal end 116 of the elongated tubular shaft 112 and extend distally therefrom. In some cases, the distal tip 140 can be a polymer distal tip, which can be made of an elastomer (e.g., ), thermoplastic polymers, polyether block amide copolymers, or any other suitable polymer. In some cases, distal tip 140 can be formed as a co-extrusion comprising a first layer or inner layer formed from a first polymeric material and a second layer or outer layer formed from a different second polymeric material, as described with reference to Figures 3 to 4Aas discussed. In other cases, the distal tip 140 may be an extrusion of a single polymer material. The distal tip 140 may be formed over the exposed area 131 of the intermediate layer 130 and the marker band 120 and extend distally beyond the distal end 116 of the elongated tubular shaft 112 to the distal end 141 of the distal tip 140. For example, the distal tip 140 may be extruded (including by a co-extrusion process) over the exposed area 131 of the intermediate layer 130 and the marker band 120, wherein the extrudate extends distal to the distal end 116 of the elongated tubular shaft 112. Thus, the molten polymer material of the distal tip 140 may flow into the gaps 118 in the exposed area 131 of the intermediate layer 130 (e.g., into the gaps 118 defined between the braided filaments of the intermediate layer 130) during the extrusion process and, in some cases, may be bonded to the inner layer 136 between a plurality of gaps 118 in the exposed area 131 of the intermediate layer 130, as Figure 2B 145 in the figure. In some cases, the proximal portion 142 of the distal tip 140 can radially surround and overlap the distal portion 134 of the outer layer 132, such as the distally tapered portion. Thus, the proximal end 143 of the material forming the distal tip 140 (i.e., the proximal end 143 of the proximal portion 142 of the distal tip 140) can be located proximal to the distal end 133 of the outer layer 132.

[0053] Figure 3 is a transverse cross-sectional view of an exemplary distal tip 200 of a catheter (e.g., catheters 10, 100), Figure 3A yes Figure 3 0.014 inch, 0.018 inch, or 0.035 inch guidewire. For example, the inner diameter can be, for example, from about 0.015 inch to about 0.017 inch, from about 0.019 inch to about 0.022 inch, or from about 0.034 inch to about 0.038 inch. In some cases, the wall of the distal tip 200 can include a radial thickness 240 in the range of from about 0.002 inch to about 0.003 inch, or any other suitable radial thickness.

[0054] In some cases, distal tip 200 may be formed as a coextrusion comprising a first or inner layer 210 formed of a first polymeric material and a second or outer layer 220 formed of a second, different polymeric material, such as Figure 3In some cases, the distal tip 200 can be formed from a material that is softer (i.e., lower durometer) than the rest of the elongated shaft of the catheter (e.g., catheter 10), such as by using a polymer or elastomer having a Shore durometer of less than 40D. In some cases, the distal tip 200 can be formed from a polymer having a Shore durometer of approximately 35D or less. In some cases, the inner layer 210 can be formed from a first polyether block amide copolymer, and the outer layer 220 can be formed from a different second polyether block amide copolymer surrounding the first polyether block amide copolymer. In some cases, the first polyether block amide copolymer (e.g., inner layer 210) can be formed from a 63D and bismuth subcarbonate (BiSubC), such as about 70% of 63D and about 30% bismuth subcarbonate. In some cases, the second polyether block amide copolymer (eg, outer layer 220) may be composed of 25D and barium sulfate (BaSO4), such as about 80% of 25D and about 20% barium sulfate. These are just examples.

[0055] like Figure 3A As shown, the inner layer 210 may include a radial thickness 215 in the range of about 0.0012 inches to about 0.0016 inches, or about 0.0014 inches, and the outer layer 220 may include a radial thickness 225 in the range of about 0.0008 inches to about 0.0012 inches, or about 0.0010 inches. In some cases, the ratio of the radial thickness 215 of the inner layer 210 to the radial thickness 225 of the outer layer 220 may be about 1.4:1. These are merely examples.

[0056] Figure 4 is a transverse cross-sectional view of an exemplary distal tip 300 of a catheter (e.g., catheters 10, 100), Figure 4A yes Figure 4 0.014 inch, 0.018 inch, or 0.035 inch guidewire. For example, the inner diameter can be, for example, from about 0.015 inch to about 0.017 inch, from about 0.019 inch to about 0.022 inch, or from about 0.034 inch to about 0.038 inch. In some cases, the wall of the distal tip 300 can include a radial thickness 340 in the range of from about 0.002 inch to about 0.003 inch, or any other suitable radial thickness.

[0057] In some cases, distal tip 300 may be formed as a coextrusion comprising a first or inner layer 310 formed of a first polymeric material and a second or outer layer 320 formed of a second, different polymeric material, such as Figure 4 In some cases, the distal tip 300 can be formed from a material that is softer (i.e., lower durometer) than the rest of the elongated shaft of the catheter (e.g., catheter 10), such as by using a polymer or elastomer having a Shore durometer of less than 40D. In some cases, the distal tip 300 can be formed from a polymer having a Shore durometer of approximately 35D or less. In some cases, the inner layer 310 can be formed from a first polyether block amide copolymer, and the outer layer 320 can be formed from a different second polyether block amide copolymer surrounding the first polyether block amide copolymer. In some cases, the first polyether block amide copolymer (e.g., inner layer 310) can be formed from a 55D Shore durometer. and bismuth subcarbonate (BiSubC), such as about 70% of 55D and about 70% bismuth subcarbonate. In some cases, the second polyether block amide copolymer (e.g., outer layer 320) can be composed of 35D and barium sulfate (BaSO4), such as about 80% of 35D and about 20% bismuth subcarbonate. These are just examples.

[0058] like Figure 4A As shown, the inner layer 310 may include a radial thickness 315 in the range of about 0.0010 inches to about 0.0014 inches, or about 0.0012 inches, and the outer layer 320 may include a radial thickness 325 in the range of about 0.0010 inches to about 0.0014 inches, or about 0.0012 inches. In some cases, the ratio of the radial thickness 315 of the inner layer 310 to the radial thickness 325 of the outer layer 320 may be about 1:1. These are merely examples.

[0059] 5A to 5D An exemplary method 400 of forming a catheter 100 having a distal tip 140 is shown. The method 400 may include disposing a braided intermediate layer 130 on a polymeric inner layer 136 (e.g., Figures 2 to 2B ). For example, the braided intermediate layer 130 can be braided directly onto the inner layer 136 using a braiding device. In other cases, the braided intermediate layer 130 can be braided separately and then positioned around the inner layer 136. The marker band 120 can then be positioned on the braided intermediate layer 130 to secure the braided intermediate layer 130. For example, the marker band 120 can be swaged around the braided intermediate layer 130. The polymer outer layer 132 can then be extruded onto the proximal region 137 of the braided intermediate layer 130, wherein the inner layer 136 is positioned within the intermediate layer 130, while leaving a distal portion 134 of the braided intermediate layer 130 proximal to the marker band 120 exposed from the outer layer 132, for example Figure 5A 13. The exposed area 131 of the braided intermediate layer 130 is shown. In some cases, the outer diameter of the distal region of the outer layer 132 can taper distally to the distal end 133 of the outer layer 132. In other words, the distal region of the outer layer 132 can taper radially inward in the distal direction to the distal end 133 of the outer layer 132. The exposed area 131 of the braided intermediate layer 130 can extend between the distal end 133 of the outer layer 132 and the proximal end 122 of the marker band 120. Thus, the intermediate layer 130 can extend distally beyond the distal end 133 of the outer layer such that the outer layer 132 does not surround or extend over the exposed area 131 of the intermediate layer 130.

[0060] like Figure 5B As shown, the portions of the braided intermediate layer 130 and the inner layer 136 that extend distal to the distal end 121 of the marker band 120 can be cut or otherwise removed such that the distal-most ends of the braided intermediate layer 130 and the inner layer 136 are substantially flush with the distal end 121 of the marker band 120. In other words, the distal end 116 of the elongated tubular shaft 110 can be substantially flush with the distal end 121 of the marker band 120. Figure 5B As shown, the mandrel 150 can be inserted into the lumen 115 at the distal end 116 of the elongated tubular shaft 112 , and the mandrel 150 can extend distally of the distal end 116 of the elongated tubular shaft 112 .

[0061] like Figure 5C As shown, the distal tip 140 can be extruded (including co-extrusion of multiple layers of the distal tip 140) onto the mandrel 150, as well as onto the exposed area 131 of the braided intermediate layer 130 and the marker band 120. The distal tip 140 can be extruded onto the exposed area 131 of the braided intermediate layer 130 and the marker band 120, and can extend distally beyond the distal end 121 of the marker band 120, as shown. Figure 5C As shown. For example, the distal tip 140 can be extruded (including by a co-extrusion process) onto the exposed region 131 of the intermediate layer 130 and the marker band 120, with the extrudate extending distally to the distal end 116 of the elongated tubular shaft 112. Thus, the molten polymer material of the distal tip 140 can flow into the gaps 118 in the exposed region 131 of the intermediate layer 130 (e.g., into the gaps 118 defined between the braided filaments of the intermediate layer 130) during the extrusion process and, in some cases, can bond to the inner layer 136 between the plurality of gaps 118 in the exposed region 131 of the intermediate layer 130. In some cases, a proximal portion 142 of the distal tip 140 (e.g., the proximally tapered portion of the distal tip 140) can radially surround and overlap the distal portion 134 (e.g., the distally tapered portion) of the outer layer 132. The resulting lap joint can therefore provide increased tip tensile strength at the interface between the distal tip 140 and the elongated tubular shaft 112.

[0062] The distal region of the distal tip 140 can taper to a smaller outer diameter as the distal tip 140 extends distal to the distal end 121 of the marker band 120 , and thus tapers as the distal tip 140 extends distal to the distal end 116 of the elongated tubular shaft 112 .

[0063] like Figure 5D As shown, the mandrel 150 can be removed and the distal tip 140 can then be cut to a desired length, such as about 1 millimeter (mm). In some cases, the distal tip 140 can be cut to a length of about 2.0 mm, about 1.7 mm, about 1.5 mm, about 1.3 mm, about 1.0 mm, or any other suitable length.

[0064] In some cases, such as reference Figures 3 to 4A As discussed, distal tip 140 can be formed as a coextrusion including a first or inner layer and a second or outer layer. In some cases, distal tip 140 can be formed from a material that is softer (i.e., lower durometer) than the rest of the elongated shaft of a catheter (e.g., catheter 10), for example, by using a polymer or elastomer having a Shore hardness of less than 40D. In some cases, distal tip 140 can be formed from a polymer having a Shore hardness of approximately 35D or less. In some cases, the inner layer can be formed from a first polyether block amide copolymer, and the outer layer can be formed from a different second polyether block amide copolymer radially surrounding the first polyether block amide copolymer.

[0065] The method 400 for forming a catheter 100 having a distal tip 140 can be considered as an example of a lap joint bonding process. Method 400 can be used to provide a catheter 100 having a distal tip (e.g., distal tip 140) having a reduced entry profile, improved tip tensile strength, and increased tensile elongation. For example, the process of bonding the distal tip 140 to the catheter 100 includes extruding the distal tip 140 onto the distal end 116 of the elongated tubular shaft 112 and onto a marker band. The material forming the distal tip 140 can extend into a plurality of gaps 118 in the exposed region 131 of the intermediate layer 130 (e.g., within the gaps 118 of the braided structure, and in some cases contact the inner layer 136, thereby forming a bond between the distal tip 140 and the inner layer 136. This provides a strong bond between the distal tip 140 and the distal end 116 of the elongated tubular shaft 112, which is opposite to conventional methods (e.g., butt joint bonding) of coupling the distal tip to the elongated shaft of a catheter.

[0066] Figure 6 is an exemplary diagram 500 illustrating a distal outer diameter (OD) profile 510 of a catheter, such as catheter 100. As previously described, the outer diameter of the distal end 133 of the outer layer 132 tapers distally as the outer layer 132 terminates proximal to the marker band 120. This Figure 6515 in the diagram 500, where the outer diameter of the elongated tubular shaft 112 is approximately 0.0332 inches, for example, and at 520 (just proximal to the exposed region 131), the outer diameter of the elongated tubular shaft 112 is, for example, approximately 0.0330 inches. In some cases, the outer diameter of the elongated tubular shaft 112 can increase in the region including the marker band 120 because the distal tip 140 has been formed over the exposed region 131 and the marker band 120, thereby increasing the outer diameter of the elongated tubular shaft 112 around the marker band 120 to approximately 0.0340 inches, for example, as shown at 525 on the diagram 500. The distal tip 140 can taper distally beyond the marker band 120 such that the outer diameter of the distal tip 140 can be smaller than the outer diameter of the elongated tubular shaft 112. For example, the outer diameter of the distal tip 140 can be approximately 0.0321 inches, as shown at 530. While the graph 500 illustrates the outer diameter profile of the elongated tubular shaft 112 and distal tip 140 as being within a range of approximately 0.032 inches to approximately 0.034 inches, it is contemplated that the outer diameter profile of the elongated tubular shaft 112 and distal tip 140 may include any other suitable range. For example, the outer diameter profile may be within a range of approximately 0.03 inches to approximately 0.04 inches. These are merely examples.

[0067] Figure 7 FIG6 is an exemplary graph 600 comparing the tensile forces 610 of catheters having a butt joint 620 and a lap joint 630 formed according to the present disclosure. As discussed above with reference to FIG5 , methods (e.g., method 400) for forming the distal tip 140 using the lap joint 630 can improve the tip tensile strength of the distal tip 140. For example, as shown in graph 600, when the distal tip is coupled to a catheter using the butt joint 620, the maximum tip tensile forces 610 that the butt joint 620 can withstand range from about 1.02 Newtons (N) to about 1.6 Newtons (N), e.g., an average value 625 of about 1.25 Newtons (N). However, when the distal tip 140 is secured to a catheter 100 using the lap joint 630 described herein, the maximum tip tensile forces 610 that the lap joint 630 can withstand range from about 1.3 Newtons (N) to about 1.78 Newtons (N), e.g., an average value 635 of about 1.5 Newtons (N). Thus, lap joints formed according to the present disclosure can have a tensile strength of 1.3 Newtons or greater, 1.5 Newtons or greater, or 1.7 Newtons or greater.

[0068] Figure 8FIG7 is an exemplary graph 700 comparing the tensile elongation 710 of a catheter having a butt joint 720 and a lap joint 730 formed according to the present disclosure. As discussed above with reference to FIG5 , a method (e.g., method 400) of forming a distal tip 140 using a lap joint 730 can increase the tensile elongation 710 of the distal tip 140. For example, as shown in graph 700 , when the distal tip is coupled to a catheter using a butt joint 720, the maximum tensile elongation of the distal tip ranges from approximately 1.8 millimeters (mm) to approximately 3 mm, e.g., an average value 725 of approximately 2.4 mm. However, when the distal tip 140 is secured to a catheter 100 using the lap joint 730 described herein, the maximum tensile elongation of the distal tip 140 ranges from approximately 9 mm to approximately 11.7 mm, e.g., an average value 735 of approximately 10.5 mm. Thus, a lap joint formed according to the present disclosure can have a tensile elongation of 9 mm or greater, 10 mm or greater, or 11 mm or greater.

[0069] The catheters 10, 100 and their various components may be manufactured according to essentially any suitable manufacturing technique, including extrusion, co-extrusion, molding, casting, machining, and the like, or any other suitable technique. In addition, the various structures may include materials commonly associated with medical devices, such as metals, metal alloys, polymers, metal-polymer composites, ceramics, combinations thereof, and the like, or any other suitable material. These materials may include transparent or translucent materials to aid in visualization during surgical procedures. Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steels; low carbon steels; nickel alloys, such as linear elastic and / or superelastic nitinol; nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as 625; UNS: N06022, such as C- UNS: N10276, such as other alloys, etc.); nickel-copper alloys (such as UNS: N04400, 400, 400, 400, etc.); Nickel-Cobalt-Chromium-Molybdenum alloys (e.g. UNS: R30035, MP35- etc.); Nickel-Molybdenum alloys (e.g. UNS: N10665, ); other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (such as UNS: R30003, such as etc.); reinforced stainless steel; combinations thereof; or any other suitable material.

[0070] Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, such as available from DuPont ), polyether block esters, polyurethanes, polypropylene (PP), polyvinyl chloride (PVC), polyether-esters (e.g., available from DSM Engineering Plastics ), ether- or ester-based copolymers (e.g., butene / poly(alkylene ether) phthalates and / or other polyester elastomers, such as those available from DuPont ), polyamides (e.g. available from Bayer Or available from ElfAtochem ), elastic polyamides, block polyamide / ether, polyether block amide (PEBA, for example available under the trade name obtained under the following conditions), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex high density polyethylene, Marlex low density polyethylene, linear low density polyethylene (e.g. ), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly(p-phenylene terephthalamide) (e.g. ), polysulfone, nylon, nylon-12 (such as available from EMS American Grilon Company ), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy resin, polyvinylidene chloride (PVdC), polycarbonate, ionomer, biocompatible polymer, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, etc.

[0071] It should be understood that this disclosure is in many respects illustrative only. Changes may be made in detail, particularly in shape, size, and arrangement of steps, without departing from the scope of this disclosure. This may include, to the extent appropriate, incorporating any feature of one exemplary embodiment into other embodiments. The scope of this disclosure is, of course, defined by the language of the appended claims.

Claims

1. A catheter, comprising: An elongated tubular shaft having a distal end, a proximal end, and a lumen extending therethrough, the elongated tubular shaft comprising: polymer outer layer; a polymer inner layer; and a woven intermediate layer positioned between the inner layer and the outer layer; a marker band positioned adjacent the distal end of the elongated tubular shaft and surrounding the intermediate layer; and a polymeric distal tip attached to the distal end of the elongated tubular shaft; wherein the distal end of the outer layer terminates proximally of the marker band such that the intermediate layer includes an exposed region that emerges from the outer layer between the distal end of the outer layer and the proximal end of the marker band; The distal tip is formed on the exposed area of ​​the middle layer and the marker band, and extends distally beyond the distal end of the elongated tubular shaft.

2. The catheter according to claim 1, wherein The outer layer terminates at a distance proximal to the marker band in a range of about 0.5 millimeters (mm) to about 1.5 mm.

3. The catheter according to claim 1 or 2, wherein: The distal tip provides a tensile strength in the range of 1.42 Newtons (N) to 1.55 Newtons.

4. The catheter according to any one of claims 1 to 3, wherein The distal tip provides a tensile strength of approximately 1.5 Newtons.

5. The catheter according to any one of claims 1 to 4, wherein The distal tip is formed from a polyether block amide copolymer.

6. The catheter according to any one of claims 1 to 5, wherein The proximal portion of the distal tip surrounds and overlaps the distal portion of the outer layer.

7. The catheter according to any one of claims 1 to 6, wherein The distal tip is formed from a coextrusion including a first polyether block amide copolymer layer and a second polyether block amide copolymer layer surrounding the first polyether block amide copolymer layer.

8. The catheter according to claim 7, wherein The radial thickness ratio of the first polyether block amide copolymer layer to the second polyether block amide copolymer layer is about 1:

1.

9. The catheter according to claim 7, wherein A radial thickness ratio of the first polyether block amide copolymer layer to the second polyether block amide copolymer layer is about 1:1.

4.

10. A catheter comprising: An elongated tubular shaft having a distal end, a proximal end, and a lumen extending therethrough, the elongated tubular shaft comprising: a polymeric inner layer having an inner surface defining the lumen of the elongated tubular shaft, the inner layer extending continuously from the proximal end of the elongated tubular shaft to the distal end of the elongated tubular shaft; a braided intermediate layer surrounding the inner layer, the intermediate layer extending continuously from the proximal end to the distal end of the elongated tubular shaft; a polymeric outer layer surrounding the intermediate layer, the outer layer extending continuously from the proximal end of the elongated tubular shaft to a distal end of the outer layer, the distal end of the outer layer being located proximal to the distal end of the elongated tubular shaft such that the intermediate layer includes a distal region extending distally of the distal end of the outer layer; and A polymeric distal tip is extruded onto the distal region of the intermediate layer and extends distally beyond the distal end of the elongated tubular shaft.

11. The catheter according to claim 10, wherein The proximal portion of the distal tip surrounds and overlaps the distal portion of the outer layer.

12. A method of forming a catheter having a distal tip, the method comprising: disposing a braided middle layer on the polymer inner layer; positioning a marker tape on the woven intermediate layer; extruding a polymer outer layer onto a proximal region of the braided intermediate layer while exposing a distal region of the braided intermediate layer from the outer layer, the exposed distal region of the braided intermediate layer extending between a distal end of the outer layer and a proximal end of the marker band; cutting away a portion of the braided middle layer and the inner layer extending distally to a distal end of the marker band; Thereafter, extruding a distal tip over the exposed distal region of the braided intermediate layer and the marker band; Wherein, the distal tip extends distally beyond the distal end of the marker band.

13. The method according to claim 12, wherein: The distal tip is bonded to the inner layer between a plurality of gaps in the exposed distal region of the intermediate layer.

14. The method according to claim 12 or 13, wherein: The outer layer terminates at a distance within a range of about 0.5 millimeters (mm) to about 1.5 mm proximal to the marker band, and wherein a proximal portion of the distal tip surrounds and overlaps the distal region of the outer layer.

15. The method according to any one of claims 12 to 14, wherein The distal tip provides a tensile strength in the range of 1.42 Newtons (N) to 1.55 Newtons.

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