Endovascular device with enhanced single-beam cutout pattern

Abstract

Endovascular devices with enhanced single-beam cut patterns are disclosed. An elongated member includes a plurality of fenestrations defining a plurality of axially extending beams interspersed between a plurality of circumferentially extending rings. The beams are formed using a double pass cutting method in which a blade makes two rotationally offset passes of a cut at a given longitudinal location of the elongated member. The resulting beams have an enhanced structure that avoids overly sharp edges and minimizes structural weaknesses.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 16 / 855,366, filed April 22, 2020, entitled “INTRAVASCULAR DEVICE WITH ENHANCED ONE-BEAM CUT PATTERN,” and U.S. Provisional Patent Application Serial No. 62 / 842,216, filed May 2, 2019, entitled “INTRAVASCULAR DEVICE WITH ENHANCED ONE-BEAM CUT PATTERN,” the entire contents of which are incorporated herein by reference. Background Technology

[0003] In the medical field, interventional devices such as guidewires and catheters are frequently used to perform delicate surgeries deep within the human body. Typically, a catheter is inserted into a patient's femoral, radial, carotid, or jugular vein and guided as needed through the patient's vascular system to reach the heart, brain, or other target anatomical structures. Usually, a guidewire is first guided to the target anatomical structure, and one or more catheters subsequently pass over the guidewire and are guided to the target anatomical structure. Once in place, the catheter can be used to deliver drugs, stents, embolization devices, radiopaque dyes, or other devices or substances to treat the patient in a desired manner.

[0004] In many applications, such interventional devices must navigate at an angle through the meandering and tortuous sections of the vascular system to reach the target anatomical structure. For example, the portion of the guidewire and / or catheter that guides into the neurovascular system needs to pass through the internal carotid artery and other meandering pathways. Such interventional devices (especially closer to their distal end) require sufficient flexibility to guide such meandering pathways.

[0005] In some cases, portions of the device are microfabricated to increase flexibility. For example, the guidewire may include an outer elongated tube that includes a series of machine-cut windows near its distal end and sometimes elsewhere. The cuts are typically arranged to define a series of axially extending “beams” that connect to a series of circumferentially extending “loops”.

[0006] While such microfabrication techniques are beneficial for increasing the flexibility of slender vascular components, several challenges remain. Therefore, there has long been a need for improved vascular devices and methods to manufacture such devices. Summary of the Invention

[0007] An endovascular device with an enhanced single-beam cut pattern is disclosed, comprising a guidewire and a microcatheter. The elongated member includes multiple windows defining multiple axially extending beams distributed among multiple circumferentially extending rings. The beams are formed using a dual-pass cutting method, in which a blade makes two rotationally offset cuts through the elongated member at each longitudinal location. The resulting beams have enhanced structural features, avoiding excessively sharp edges and minimizing structural weaknesses.

[0008] In one embodiment, an intravascular device includes an elongated member extending along a longitudinal axis between a proximal end and a distal end. The elongated member has a plurality of openings defining a plurality of axially extending beams and circumferentially extending rings. At least one beam includes an inner surface, an outer surface, and a pair of side surfaces, wherein the angle formed between the inner surface and one or both side surfaces is less than 135 degrees.

[0009] In one embodiment, a method of manufacturing an intravascular device includes the following steps: providing a raw material; inserting a blade into the raw material to form a first incision in the raw material, but not completely penetrating the raw material, the blade being oriented such that the cutting edge is substantially perpendicular to the longitudinal axis of the raw material; rotating the raw material relative to the blade without allowing the raw material to advance longitudinally relative to the blade; and inserting the blade into the raw material to form a second incision.

[0010] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are intended to provide further explanation of the claimed invention. Attached Figure Description

[0011] Various objects, features, characteristics, and advantages of the invention will become apparent and more readily understood from the following description of embodiments taken in conjunction with the accompanying drawings and appended claims, all of which form part of this specification. In the various drawings, the same reference numerals denote corresponding parts, and the various elements depicted are not necessarily drawn to scale; and in which:

[0012] Figure 1 Exemplary intravascular devices, such as guidewires or microcatheters, are shown;

[0013] Figure 2 The distal end of an embodiment of an endovascular device configured as a guidewire is shown;

[0014] Figure 3 A slender member with a single-beam cutout pattern is shown;

[0015] Figure 4 A typical process for forming a single-beam cut pattern in a piece of raw material is shown;

[0016] Figure 5A and Figure 5B It shows from Figure 4 The beam structure obtained by the standard cutting process shown; and

[0017] Figures 6A to 6C An alternative cutting process and an improved beam structure obtained from this alternative cutting process are shown. Detailed Implementation

[0018] Overview of intravascular devices

[0019] Figure 1 An exemplary endovascular device 100 is illustrated, comprising an elongated member 104 extending between a proximal end portion 106 and a distal end portion 108. An optional handle / hub / torquer 102 may be attached to the proximal end portion 106. The elongated member 104 may be, for example, a guidewire or microcatheter.

[0020] The elongated member 104 may include a plurality of openings cut into its outer surface. The openings can be formed by cutting one or more pieces of raw material to create a cut pattern that leaves the openings. The openings can provide various benefits, including increased flexibility of the elongated member 104. In some embodiments, the openings are arranged to provide enhanced flexibility (relative to a similar section of raw material without openings) while maintaining sufficient circumferential structure to effectively transmit torque.

[0021] The elongated member 104 can be of any length required to guide the patient's anatomical structures to the target anatomical region. For example, a typical length can range from about 50 cm to 300 cm. In catheter embodiments, the outer diameter of the elongated member 104 can range from about 0.010 inches to about 0.150 inches, but larger or smaller diameters may also be used depending on preference and / or application requirements. In guidewire embodiments, the outer diameter of the elongated member 104 can be about 0.014 inches, or can range from about 0.008 inches to 0.145 inches, but larger or smaller sizes may also be used depending on user preference and / or application requirements.

[0022] In catheter embodiments, the elongated member 104 is typically formed of a material having an elastic modulus of about 3000 MPa to about 4500 MPa, or about 3500 MPa to about 4000 MPa. In one exemplary embodiment, the elongated member 104 is formed of or comprises polyetheretherketone (PEEK). Other polymers with higher moduli may also be used where cost and / or manufacturing considerations allow. In some embodiments, the elongated member 104 comprises or is formed of a nickel-titanium alloy, which has superelastic properties at body temperature. In some embodiments, at least a portion of the elongated member 104 (e.g., the proximal portion) is formed of stainless steel or other materials having similar stress-strain and elastic modulus properties. Typically, if the elongated member 104 is formed of two or more different materials, a higher modulus material is used in the proximal segment, while a lower modulus material is used in the distal segment.

[0023] Figure 2 The distal end of an embodiment of an intravascular device configured as guidewire 200 is shown. Figure 2 The embodiments shown can represent Figure 1 The distal end 108 of the guide wire embodiment of the elongated member 104. Figure 2 The embodiment shown includes an internal component configured as core 212. Other embodiments may additionally or alternatively include one or more other internal components, such as one or more internal tubular structures.

[0024] The illustrated guidewire 200 includes a core 212 and a tubular structure 214 coupled to the core 212. As shown, a distal segment 221 of the core 212 extends into and is surrounded by the tubular structure 214. In some embodiments, the distal segment 221 of the core 212 is ground to taper to a smaller diameter (e.g., about 0.002 inches) at its distal end. The distal segment 221 of the core 212 may have a circular cross-section, a rectangular cross-section, or other suitable cross-sectional shape. In this example, the core 212 and the tubular structure 214 have substantially similar outer diameters at their attachment point 213, where they are adjacent to and attached to each other.

[0025] The tube 214 can be coupled to the core 212 in a manner that allows torque to be transmitted from the core 212 to the tube 214 and thus further distally through the tube 214 (e.g., using adhesives, brazing, and / or welding). Medical-grade adhesive 220 can be used to couple the tube 214 to the core 212 at the distal end of the device and form a wound-resistant covering.

[0026] The guidewire 200 may also include one or more coils (such as coil 224) disposed within the tube 214 for positioning between the outer surface of the distal segment of the core 212 and the inner surface of the tube 214. Coil 224 may be formed of a radiopaque material (such as platinum). The coil 224 shown is formed as a single piece. In alternative embodiments, coil 224 comprises multiple individual segments stacked, positioned adjacent to each other, and / or interlocked by winding.

[0027] The tube 214 may include microfabricated windows configured to provide effective flexibility and torsion capability to the intravascular device. Some embodiments may additionally or alternatively include cuts formed in the core 212 itself along the distal segment 221 of the core.

[0028] Standard single beam cut pattern

[0029] Figure 3 An elongated member 900 with multiple beams 932 and rings 934 is shown. Because a single beam 932 is positioned between each pair of adjacent rings 934, the elongated member 900 is an example of a single-beam cut-out pattern. In this example, each subsequent beam is rotated approximately 180 degrees away from the preceding beam 932. Other embodiments may have different rotational offset patterns or may omit the rotational offset so that the beams are aligned on one side of the elongated member 900.

[0030] Some embodiments may include beams 932 arranged in a “spiral” pattern or a non-linear pattern (such as a “distributed” pattern, a “partial ramp” pattern, a “zigzag” pattern) or a combination thereof, each beam arranged in a different segment of the elongated member 900. These notch patterns are described in more detail in PCT International Application No. PCT / US2018 / 034756 (published under International Publication No. WO 2018 / 218216 A1), the entire contents of which are incorporated herein by reference.

[0031] In some embodiments, the rings and beams of the intravascular device may be encapsulated in a polymer. Intravascular devices (including guidewires and microcatheters) with polymer-encapsulated microfabricated structures are described in more detail in U.S. Patent Nos. 9067332, 9950137, 9067333, and 9072873, the entire contents of which are incorporated herein by reference.

[0032] Figure 4A typical process for forming a single-beam cut pattern in a piece of raw material 302 is illustrated. The raw material 302 (typically a tubular structure) is positioned in a cutting machine having one blade 304 (or more blades). As indicated by arrow 306, the blade 304 is movable along an axis perpendicular to the longitudinal axis of the raw material 302 to form a window 303. Although the blade 304 is shown here moving up and down along a vertical axis, other configurations may have one blade (or more blades) moving along a horizontal axis or even a diagonal axis.

[0033] To make a cut, the blade 304 contacts the raw material 302 and moves inward until a cut is formed at the desired depth, leaving the resulting beam 310 in the raw material 302. The blade 304 is then withdrawn from the raw material 302. The raw material 302 is then moved longitudinally relative to the blade 304, as indicated by arrow 308, until the next desired cutting position is aligned with the blade 304. This process can then be repeated to form a desired number of cuts.

[0034] The cutting depth and / or the spacing between incisions can vary from one device to the next, or even from one segment of a device to another segment of the same device. For example, to increase relative flexibility at the distal portion, the segment intended to form the distal portion of an intravascular device may include relatively deep and / or relatively small-spaced incisions.

[0035] In some embodiments, such as those forming helical or nonlinear patterns, the raw material 302 may be rotated between successive cuts or between successive groups of cuts to allow rotational offset in the resulting beam, as indicated by arrow 312. Additional details relating to the cutting machine and related manufacturing methods are described in U.S. Patent No. 10,232,141, the entire contents of which are incorporated herein by reference.

[0036] Figure 5A and Figure 5B A more detailed description is provided from... Figure 4 The structure of beam 310 obtained by the standard cutting process shown is illustrated. Figure 5A A front cross-sectional view of the raw material 302 is shown, extending along a line parallel to the blade path of a specific cut. Figure 5B An enlarged view of the edge segment of the resulting beam 310 is shown. As shown, typically, the blade 304 has a diameter significantly larger than that of the raw material 302 (e.g., a typical blade diameter can be in the range of 2 inches to 4 inches). Figure 5A The image shows the deepest point of the blade 304 within the raw material 302. After the blade 304 is removed, the resulting beam 310 is left.

[0037] like Figure 5B As shown in the optimal diagram, the resulting beam 310 includes an inner surface 320, an outer surface 322, and two side surfaces 324. Figure 5B (Only one is shown in the image). Each side surface 324 engages with the inner surface 320 along the inner edge 326 and with the outer surface 322 along the outer edge 328. An angle 330 is formed at the engagement of the inner surface 320 and the side surface 324.

[0038] Because of the geometry of the cut, angle 330 is significantly greater than 90 degrees, and typically about 135 degrees. As a structural result of this dimension of angle 330, the radial thickness of beam 310 thins from the inner edge 326 to the outer edge 328. "Radial thickness" refers to the thickness of the beam along a radial line extending from the geometric center of the cross-section of tube structure 302 to the outer surface 322. Thus, while beam 310 has a substantially uniform radial thickness over most of its circumferential length (as shown by radial line 332a), the radial thickness tapers between the inner edge 326 and the outer edge 328 (as shown by the gradually shortening radial lines 332b and 332c).

[0039] Another structural result of this edge 328 will be that it will be relatively “sharp”. That is, the angle 331 formed between the side surface 324 and the outer surface 322 will be relatively small, such as about 45 degrees or less.

[0040] Reinforced single beam cut pattern

[0041] Figures 6A to 6C An alternative method for forming beam 410 in a section of raw material 402 is shown. For example... Figure 6A As shown, the blade 404 first enters the raw material 402 until it... Figure 5A The standard incision shown is relatively shorter (shallower) in depth. For example, in Figure 5A The standard cut shown typically has a depth of approximately 70% or more of the diameter of the raw material. Figure 6A The initial incision depth shown is approximately 50% (e.g., approximately 30% to approximately 70%).

[0042] After the initial cut is formed, the raw material 402 is rotated relative to the blade 404 to allow the blade 404 to enter the raw material 402 a second time, as shown. Figure 6B As shown. During the first and second entry of the blade 404, the raw material 402 maintains the same longitudinal position relative to the blade, such that the second cut is in the same plane as the first cut. During the first cut, a first side surface 424a is formed and a temporary side surface 424c is formed. Then, the second cut removes the temporary side surface 424c and cuts additional material to form a second side surface 424b.

[0043] Despite from Figures 6A to 6B The sequence gives the appearance of the blade 404 rotating clockwise relative to the raw material 402, but it will be understood that this is only for illustrative purposes, and any suitable relative rotation between the raw material 402 and the blade 404 can be used by rotating the blade 404, rotating the raw material 402, or rotating both. Typically, the raw material 402 will rotate relative to the rotationally static blade 404. The relative rotation is preferably about 90 degrees (e.g., about 60 degrees to about 120 degrees, or about 75 degrees to about 105 degrees).

[0044] Figure 6C An enlarged view of the edge segment of the resulting beam 410 is shown. The resulting beam 410 includes an inner surface 420, an outer surface 422, and a pair of side surfaces 424 (a single side surface 424b is shown here). Each side surface 424 engages with the inner surface 420 along its inner edge 426 and with the outer surface 422 along its outer edge 428. An angle 430 is formed at the engagement of the inner surface 420 and the side surface 424.

[0045] and Figure 5B Compared to the angle 330 of beam 310 shown, the angle 430 of beam 410 is significantly smaller. For example, angle 430 can have a value falling within a range having a lower endpoint of approximately 75 degrees, 80 degrees, 85 degrees, or 90 degrees and an upper endpoint of approximately 130 degrees, 120 degrees, 110 degrees, or 100 degrees. Most preferably, angle 430 is approximately 90 degrees, such that side surface 424b is substantially perpendicular to inner surface 420.

[0046] The structure of beam 410 offers a significant improvement over the standard beam 310. For example, beam 410 avoids the “sharp” outer edge 428 present in the standard beam 310. In other words, the angle 431 formed between the side surface 424 and the outer surface 422 is greater than 45 degrees, such as about 50 degrees to about 90 degrees.

[0047] The improved beam 410 also avoids the tapered profile of the standard beam 310 and has a more uniform radial thickness along its circumferential length. This advantageously minimizes structural weaknesses and provides beam 410 with a longer fatigue life.

[0048] Surprisingly, the double-pass cutting process also improved manufacturing efficiency and yield compared to the standard single-pass process. Even with double the number of blade passes, the double-pass process requires a smaller depth for each cut and typically produces more precise cuts. This has been found to be sufficient to compensate for the additional time required to cut each beam twice.

[0049] Additional exemplary embodiments

[0050] The following are some exemplary embodiments of the disclosed intravascular devices and related methods. These are presented by way of example only and are not intended to limit the scope of the invention in any way.

[0051] Example 1: An intravascular device comprising an elongated member extending along a longitudinal axis between a proximal end and a distal end, the elongated member having a plurality of windows defining a plurality of axially extending beams and circumferentially extending rings. At least one beam includes an inner surface, an outer surface, and a pair of side surfaces, wherein the angle formed between the inner surface and one or both of the side surfaces is less than 135 degrees.

[0052] Example 2: The device according to Example 1, wherein the angle is between about 75 degrees and about 130 degrees.

[0053] Example 3: The apparatus according to Example 1 or 2, wherein the angle is between about 80 degrees and about 120 degrees, or between about 85 degrees and about 110 degrees, or between about 90 degrees and about 100 degrees, or wherein the angle is about 90 degrees.

[0054] Example 4: The apparatus according to any one of Examples 1-3, wherein the elongated member is a tubular structure.

[0055] Example 5: The device according to Example 4 further includes a core disposed within the tube structure.

[0056] Example 6: The device according to Example 4 or Example 5 further includes an inner tube disposed within the tube structure.

[0057] Example 7: The apparatus according to any one of Examples 4-6 further includes one or more coils disposed within the tube structure, wherein the one or more coils optionally include one or more non-transmissive coils.

[0058] Example 8: The apparatus according to any one of Examples 1-7, wherein the elongated member comprises a polymer.

[0059] Example 9: The apparatus according to any one of Examples 1-8, wherein the ring and the beam are encapsulated in a polymer.

[0060] Example 10: The apparatus according to any one of Examples 1-9, wherein the elongated member comprises a nickel-titanium alloy.

[0061] Example 11: The apparatus according to any one of Examples 1-10, wherein the elongated member comprises stainless steel.

[0062] Example 12: The apparatus according to any one of Examples 1-11, wherein the elongated member is formed of two or more different materials.

[0063] Example 13: The apparatus according to any one of Examples 1-12, wherein the at least one beam has a substantially uniform thickness over its circumferential length.

[0064] Example 14: The device according to any one of Examples 1-13, wherein the angle formed between the outer surface and one or two side surfaces is greater than about 45 degrees.

[0065] Example 15: The device according to any one of Examples 1-14, wherein the intravascular device is a guidewire.

[0066] Example 16: The device according to any one of Examples 1-15, wherein the intravascular device is a microcatheter.

[0067] Example 17: An intravascular device comprising an elongated member extending along a longitudinal axis between a proximal end and a distal end, the elongated member having a plurality of windows defining a plurality of axially extending beams and circumferentially extending rings. At least one beam includes an inner surface, an outer surface, and a pair of side surfaces, wherein the angle formed between the inner surface and one or both side surfaces is between about 75 degrees and about 130 degrees, and wherein the angle formed between the outer surface and one or both side surfaces is greater than about 45 degrees.

[0068] Example 18: A method of manufacturing an intravascular device such as that described in any one of Examples 1-17, the method comprising: providing a raw material; inserting a blade into the raw material to form a first incision in the raw material without completely penetrating the raw material, the blade being oriented such that the cutting edge is substantially perpendicular to the longitudinal axis of the raw material; rotating the raw material relative to the blade without allowing the raw material to advance longitudinally relative to the blade; and inserting the blade into the raw material to form a second incision.

[0069] Example 19: The method according to Example 18, wherein the raw material is rotated about 60 degrees to about 120 degrees relative to the blade.

[0070] Example 20: The method according to Example 18 or Example 19, wherein the first cut is formed by inserting the blade into the raw material to a depth of about 30% to about 70% of the diameter of the raw material.

[0071] Example 21: The method according to any one of Examples 18-20, wherein the second cut is formed by inserting the blade into the raw material to a depth of about 30% to about 70% of the diameter of the raw material.

[0072] in conclusion

[0073] Although certain embodiments of this disclosure have been described in detail with reference to specific configurations, parameters, components, elements, etc., such descriptions are illustrative and should not be construed as limiting the scope of the claimed invention.

[0074] Furthermore, it should be understood that, for any given element or component of the described embodiments, unless otherwise implied or expressly stated, any possible alternatives listed for that element or component may generally be used alone or in combination with each other.

[0075] Furthermore, unless otherwise stated, figures used in the specification and claims to indicate quantities, components, distances, or other measurements should be understood as optionally modified by the term "about" or its synonyms. When the terms "about," "approximately," "basically," etc., are used in conjunction with the stated quantity, value, or condition, they can be considered to refer to a quantity, value, or condition that deviates from the stated quantity, value, or condition by less than 20%, less than 10%, less than 5%, or less than 1%. At least, and without attempting to limit the application of the doctrine of equivalence to the scope of the claims, each numerical parameter should be interpreted according to the number of significant figures reported and by applying ordinary rounding techniques.

[0076] Any headings and subheadings used herein are for organizational purposes only and are not intended to limit the scope of the specification or claims.

[0077] It should also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” do not exclude plural references unless the context clearly specifies otherwise. Thus, for example, an embodiment referring to a single reference (e.g., “part”) may also include two or more such references.

[0078] It will also be understood that the embodiments described herein may include properties and features (e.g., components, parts, elements, components, and / or portions) described in other embodiments described herein. Therefore, various features of a given embodiment may be combined with and / or incorporated into other embodiments of this disclosure. Consequently, the disclosure of certain features relative to a particular embodiment of this disclosure should not be construed as limiting the application or inclusion of said features to that particular embodiment. Rather, it will be understood that other embodiments may also include such features.

Claims

1. A method of manufacturing an endovascular device, the method comprising: providing a piece of starting material; passing a blade into the starting material to form a first cut in the starting material without fully penetrating the starting material, the blade being oriented so that a cutting edge is substantially perpendicular to a longitudinal axis of the starting material; rotating the starting material relative to the blade by about 60 degrees to about 120 degrees without advancing the starting material longitudinally relative to the blade; and passing the blade into the starting material to form a second cut, wherein the first cut and the second cut together form a single beam between adjacent rings, wherein the beam includes an inner surface, an outer surface, and a pair of side surfaces; and wherein an angle formed between the inner surface and one or both of the side surfaces is between about 75 degrees and about 130 degrees.

2. The method of claim 1, wherein, the first cut is formed by passing the blade into the starting material to a depth of about 30% to about 70% of a diameter of the starting material.

3. The method of claim 2, wherein, the second cut is formed by passing the blade into the starting material to a depth of about 30% to about 70% of a diameter of the starting material.

4. The method of claim 2, wherein, the first cut is formed by passing the blade into the starting material to a depth of about 50% of a diameter of the starting material, and wherein the second cut is formed by passing the blade into the starting material to a depth of about 50% of a diameter of the starting material.

5. The method of claim 1, wherein, rotating the starting material relative to the blade includes rotating the starting material by about 75 degrees to about 105 degrees.

6. The method of claim 1, wherein, the starting material is a tube structure.

7. The method of claim 1, wherein, the starting material includes nickel-titanium alloy.

8. The method of claim 1, wherein, the starting material includes stainless steel.

9. The method of claim 1, wherein, the beam has a substantially uniform thickness over a circumferential length thereof.

10. The method of claim 1, wherein, an angle formed between the outer surface and one or both side surfaces is greater than about 45 degrees.

Images