HK40083587A - Guidewire having enlarged, micro-fabricated distal section - Google Patents

Description

Guidewire with enlarged micromachined distal section

Cross Reference to Related Applications

U.S. patent application Ser. No. 17/154,777 entitled "guiding Having Enlarged, micro-Fabricated Distal Section" filed on 21/1/2021 and U.S. provisional patent application Ser. No. 62/965,005 entitled "guiding Having Enlarged, micro-Fabricated Distal Section" filed on 23/1/2020, priority and benefit of the present application. Each of the foregoing applications is incorporated by reference herein in its entirety.

Background

Guidewire devices are commonly used to introduce or guide catheters or other interventional devices to a target anatomical location within a patient. Typically, a guidewire enters and passes through the vasculature of a patient to reach a target location, which may be at or near the heart or brain of the patient, for example. Radiographic imaging is commonly used to assist in navigating (navigates) the guidewire to the target location. In many cases, a guidewire is placed in the body during an interventional procedure in which the guidewire may be used to guide multiple catheters or other interventional devices to a target anatomical location.

The guidewire can have various outer diameter dimensions. For example, widely used dimensions include 0.010, 0.014, 0.016, 0.018, 0.024, 0.035 and 0.038 inches, although guidewires may also be smaller or larger in diameter. Because torque transfer is a function of diameter, larger diameter guidewires generally have greater torque transfer (the ability to efficiently transfer torque from a proximal section of wire to a more distal section of wire). On the other hand, smaller diameter guidewires generally have greater flexibility.

The catheter used in conjunction with the guidewire will be sized with an inner diameter slightly larger than the outer diameter of the guidewire to enable the catheter to be positioned and translated over the guidewire. The size difference between the guidewire and the catheter can affect the ability of the catheter to travel along the guidewire. For example, the larger the annular space between the outer diameter of the guidewire and the inner diameter of the catheter, the greater the potential radial offset the catheter may experience and the more difficult it is to navigate the catheter over the guidewire. In the event of too large a radial offset, the distal end of the catheter may have a higher risk of jamming the vasculature or other anatomy of the patient rather than following smoothly along the guidewire path.

In general, the guidewire size is selected to minimize the amount of annular space between the guidewire and a given catheter size needed or desired for a particular procedure, thereby limiting the types of problems described above. However, this approach presents several challenges. For example, increasing the size of the guidewire may also excessively increase the stiffness of the guidewire, possibly reaching levels that are undesirable for initial placement of the guidewire at the target treatment site. Furthermore, while there are known methods of increasing guidewire flexibility (such as reducing the core wire diameter), these methods typically come at the expense of the torqueability of the device.

Accordingly, there is a need for a guidewire device that can be manufactured to have a relatively large outer diameter at least at the distal section, that minimizes the annular space between the guidewire and compatible catheters of certain sizes, and that also can provide sufficient flexibility and torqueability along its length.

Drawings

Various objects, features, characteristics and advantages of the present invention will become apparent and more readily appreciated from the description of the embodiments taken in conjunction with the accompanying drawings and appended claims, all forming a part of this specification, wherein like reference numerals designate corresponding parts in the various figures, and wherein the various elements depicted are not necessarily drawn to scale; wherein:

fig. 1 shows an embodiment of a guidewire device having a core and an outer tube, and which may utilize one or more of the components described herein;

FIG. 2 shows an exemplary embodiment of a guidewire device having a tube with an outer diameter that is larger than the outer diameter of the proximal section of the core;

fig. 3 is a detailed view of the distal section of the guidewire of fig. 2 with the tube structure removed to better illustrate the basic features of the device;

FIG. 4 is a detailed view of the tube of the guidewire of FIG. 2;

fig. 5 is a cross-sectional view of the distal section of the guidewire of fig. 2, showing alignment of the beams of the single beam section of the tube with the flat distal section of the core; and

fig. 6 and 7 are cross-sectional views of the guidewire of fig. 2, showing the outer diameter of the tube being greater than the outer diameter of the proximal section of the core.

Detailed Description

Brief introduction to the drawings

Fig. 1 schematically illustrates general components of a guidewire 100, which may utilize one or more features described in more detail below.

The illustrated guidewire 100 includes a core 102 and an outer tube 104. The core 102 includes a distal section 103 (also referred to herein as a distal core 103) that extends into the outer tube 104 as shown. The distal core 103 may taper continuously or in one or more discrete sections such that more distal sections have a smaller diameter and greater flexibility than more proximal sections. In some embodiments, the distal-most section of the core 102 may be flattened into a ribbon-like shape having a flat, rectangular, or oval (oblong) cross-section. For example, the distal core 103 may be ground so as to taper to a smaller diameter at the distal end.

The core 102 and the tube 104 are typically formed of different materials. For example, the tube 104 is preferably formed of a relatively flexible and resilient material, such as nitinol, while the core 102 may be formed of a relatively less flexible and resilient material, such as stainless steel. Forming the core 102 from stainless steel (or other material having a similar modulus of elasticity) may be advantageous because it allows the distal tip to maintain shape as the operator selectively bends/shapes, and because stainless steel provides sufficient modulus of elasticity to provide more sensitive translational movement. While these materials are presently preferred, other suitable materials, such as polymers or other metals/alloys, may additionally or alternatively be used.

The tubes 104 are beneficially coupled to the core 102 in a manner (e.g., using an adhesive, brazing, and/or welding) that allows torsional forces to be transmitted from the core 102 to the tubes 104, and thereby further transmitted distally by the tubes 104. A medical grade adhesive or other suitable material may be used to couple the tube 104 to the core wire 102 at the distal end 110 of the device to form an atraumatic covering.

The outer tube 104 may include a cut-out pattern that forms fenestrations 106 in the tube. The pattern of fenestrations 106 may be arranged to provide the tube 104 with desired flexibility characteristics, including, for example, promoting a preferred direction of bending, reducing or eliminating a preferred direction of bending, or a gradient increase in flexibility along the longitudinal axis. Examples of cut patterns and other guidewire device features that may be used in the guidewire devices described herein are provided in detail in U.S. patent application publications 2018/0193607, 2018/0071496 and 2020/0121308, each of which is incorporated herein in its entirety by reference.

The proximal section of the guidewire device 100 (the portion extending proximally from the tube 104) extends proximally to a length necessary to provide sufficient guidewire length for delivery to the targeted anatomical region. The guidewire device 100 typically has a length ranging from about 50cm to about 350cm, and more typically about 200cm, depending on the needs of a particular application. The tube 104 may have a length ranging from about 5cm to about 350cm, more typically from about 15cm to about 50cm (such as about 25cm to about 40 cm).

The guidewire device 100 can have a diameter of about 0.010 inches to about 0.038 inches, although larger or smaller sizes can also be used as desired for a particular application. For example, particular embodiments can have an outer diameter dimension corresponding to standard guidewire dimensions, such as 0.014 inches, 0.016 inches, 0.018 inches, 0.024 inches, or other dimensions common to guidewire devices. The distal section 103 of the core 102 may taper to a diameter of about 0.002 inches, or a diameter in the range of about 0.001 to 0.005 inches. In some embodiments, the distal tip may be flattened (such as to a rectangular cross-section) to further enhance bending flexibility while minimizing the reduction in cross-sectional area required for tensile strength. In such embodiments, the cross-section may have dimensions of, for example, about 0.001 inch by 0.003 inch. In some embodiments, the tube 104 has a length in the range of about 3 to 350 cm.

Additional features and details regarding the foregoing components will be described in greater detail below. The following examples may be particularly beneficial in applications: wherein the corresponding catheter is sized to be about 0.027 inches or greater, and thus the guidewire is advantageously sized to be about 0.024 inches or greater to limit the amount of annular space between the inner surface of the catheter and the outer surface of the guidewire, yet allow relative movement therebetween. In such implementations, the guidewires described herein can provide sufficient diameter in the distal section of the device to limit the annular space, while still maintaining effective torqueability and lateral flexibility. However, these dimensions are not limiting, and thus the same features and details described below can also be used for guidewires smaller or larger than 0.024 inches.

Improved guidewire device with enlarged distal section

Fig. 2 shows an example of a guidewire 200. Unless otherwise indicated herein, the guidewire 200 may include any of the general features described above with respect to the guidewire 100, where like reference numerals refer to like components. As shown, the guidewire 200 includes a core 202 and an outer tube 204, wherein a distal section 203 of the core 202 is inserted into the tube 204. The outer tube 204 includes a plurality of fenestrations 206. The polymer-based adhesive may form the atraumatic distal tip 210.

The core 202 also includes a proximal section 201 (also referred to herein as the proximal core 201), the proximal section 201 being disposed proximal of the outer tube 204 and not inserted into the outer tube 204. The proximal core 201 may include a friction-reducing coating, such as Polytetrafluoroethylene (PTFE) and/or other suitable coating materials. The tube 204 may also include a coating, preferably a suitable hydrophilic coating and/or other suitable coating material.

Preferably, the outer diameter of tube 204 is slightly larger than the outer diameter of proximal core 201. In one exemplary embodiment, the proximal core 201 has an outer diameter of about 0.018 inches and the tube 204 has an outer diameter of about 0.024 inches. However, other core and/or tube sizes may be used. Preferably, the outer diameter of tube 204 is about 10% or greater, more preferably about 15% to about 80%, or more preferably about 20% to about 70%, such as about 25% to about 35% greater than the outer diameter of proximal core 201.

This is further illustrated by the cross-sectional views of fig. 6 and 7. As shown, the outer diameter (D1) of the proximal core 201 is less than the outer diameter (D2) of the tube 204. The ratio of D2 to D1 can be, for example, from about 1.1 to about 3, more preferably from about 1.15 to about 2, or from about 1.2 to about 1.75.

As described above, the larger outer diameter in the tube 204 may better match certain desired catheter sizes at the distal tip portion of the catheter, and thereby reduce the amount of annular space between the guidewire and the catheter during placement of the catheter over the guidewire. This is particularly beneficial at more distal sections of the guidewire, which are more likely to be navigated through deeper, more tortuous portions of the patient's vasculature.

However, increasing the diameter of the core 202 to match the larger diameter of the tube 204 may make the core 202 too stiff to be used for certain desired applications. Thus, maintaining a smaller core 202 while increasing the size of the tube 204 relative to the core 202 allows for the use of a more flexible core 202 while still being able to achieve the benefits of a larger tube 204 at the distal section of the guidewire 200.

However, as explained in more detail below, providing a tube 204 having a larger outer diameter than the core 202 presents other challenges. In particular, the difference in diameter between outer tube 204 and distal core 203 enlarges the annular space between the outer surface of distal core 203 and the inner surface of tube 204. Because the tube 204 may be more flexible than the distal core 203, the distal core 203 may be positioned off the centerline of the tube 204 as the wire passes through the bend. As the guidewire moves through the vasculature, such deviation can interfere with smooth distal transmission of rotational movement causing a buildup and sudden release of force that causes the guidewire to move in a "snap" and/or "jerk" manner to an undesirable preferential rotational position. This interference with tactile and rotational control of the guidewire can make it more difficult for the operator to rotationally position the guidewire as desired, increasing the risk of delayed interventional procedures, poor results, inability to access the target site, and even tissue damage.

The embodiments described herein advantageously provide additional features that help to radially center the distal core 203 within the tube 204 even if the tube 204 has a larger outer diameter than the proximal core 201. One or more centering mechanisms can be included to beneficially reduce undesirable jerky and/or rapid movement of the guidewire (i.e., the centering mechanisms can improve rotational control), thereby enabling a user to have greater rotational control and improved tactile treatment of the guidewire.

Fig. 3 shows an enlarged view of the distal section of the guidewire 200 with the tube 204 removed for better visualization of the distal core 203 and some other underlying components. As shown, the core 202 includes one or more transition regions 208 where the core 202 tapers to a smaller diameter. The distal section 211 of the core 202 may be flat. The one or more transition zones 208 may be discrete with one or more sections of the core having a substantially continuous outer diameter disposed therebetween, or the distal core 203 may have a substantially continuous taper along all or a majority of its length.

The bushing 212 may be included at a point that forms a joint to which the proximal end of the tube 204 is attached. The bushing 212 may have an outer diameter that substantially matches the outer diameter of the proximal core 201. The bushing 212 may be formed of the same material as the tube 204 (e.g., nitinol). The liner 212 provides better centering between the core 202 and the tube 204 and/or reduces the amount of adhesive needed to bond the individual components. Although the bushing 212 is shown herein as a tube, the bushing 212 may have alternative geometries such as a coil, braid (braided), slotted/cut tube, and the like.

As shown, the bushing 212 may also include a chamfered or beveled surface 214 at its proximal end to provide a smooth transition between the different diameters. The distal end of the bushing 212 may also be chamfered or beveled. Even if the distal end of the bushing 212 were to be covered by the tube 204, providing the bushing 212 with a chamfer/chamfer at both ends facilitates manufacturing, eliminating the need to ensure proper orientation of the bushing and eliminating the possibility of incorrect orientation.

The illustrated guidewire 200 includes a proximal coil 216, a distal coil 218, and a bushing coil 220 positioned over the proximal and distal coils 216, 218. Preferably, the distal coil 218 is formed of a radiopaque material (such as platinum group, gold, silver, palladium, iridium, osmium, tantalum, tungsten, bismuth, dysprosium, gadolinium, etc.). Thus, the distal coil 218 preferably allows radiographic visualization of the distal side of the guidewire 200 during surgery. The distal coil 218 may have a length of about 0.5cm to about 20cm, or more typically about 3cm to about 15cm, for example about 10 cm.

The proximal coil 216 may be formed of a radiopaque material, such as stainless steel, other suitable metals, suitable polymers, or other suitable materials, etc. The proximal coil 216 may be attached to the distal core 203 at a point adjacent or near the proximal end of the distal coil 218 and/or at any point along the coincident length of the distal core 203, most commonly at or near each end of the proximal coil 216. The proximal coil 216 may have a length of about 1 to 25cm, or more typically about 3 to 20cm, such as about 5 to 15 cm. Technically speaking, the distal coil 218 may extend further proximally to replace the proximal coil 216. However, the materials used as radiopaque markers (e.g., platinum) are expensive. Furthermore, when imaged under X-ray fluoroscopy, their use as packaging material filling most of the annular space may cause the distal section of the guidewire 200 to be too bright and thus not allow the operator to see other areas of interest. Thus, the proximal coil 216 is preferably separate from the distal coil 218 and formed of a different material than the distal coil 218.

The proximal coil 216 and the distal coil 218 assist in filling some of the annular space between the distal core 203 and the tube 204. While the coil examples shown herein are shown as wires having a circular cross-section, it should be understood that other coil types may be used. For example, one or more centering coils may be edge-wound and/or may have a cross-sectional shape that is ribbon-like, rectangular, elliptical, or other non-circular.

Although the proximal coil 216 and the distal coil 218 assist in filling some of the annular space, additional annular space also exists, particularly when a slightly larger tube 204 is used. The wire size of the proximal coil 216 and the distal coil 218 may be increased to fill more space. However, increasing the filament size excessively may impart excessive stiffness to the device. Preferably, the filament size of the proximal coil 216 and distal coil 218 is about 0.008 inches or less, or about 0.006 inches or less, or more preferably about 0.004 inches or less, such as about 0.002 inches or less.

To assist in filling the remainder of the annular space, the guidewire 200 may include a liner coil 220. A bushing coil 220 may be disposed over the proximal coil 216 and the distal coil 218. The bushing coil 220 may extend over the entirety of both the proximal coil 216 and the distal coil 218. As with the proximal coil 216 and the distal coil 218, the wire diameter of the bushing coil 220 is preferably limited. For example, the wire diameter of the liner coil may be about 0.008 inches or less, or about 0.006 inches or less, or more preferably about 0.004 inches or less, such as about 0.002 inches or less. The bushing coil 220 may be formed of stainless steel and/or other suitable material, such as another metal or polymer.

In addition to the proximal coil 216 and the distal coil 218, the use of the bushing coil 220 also assists in filling the annular space between the distal core 203 and the tube 204 without the use of oversized coils. This helps to maintain the distal core 203 centered within the tube 204, which prevents the undesirable effects of misalignment that have been described above, while also having minimal impact on the bending flexibility of the device.

In some embodiments, the bushing coil 220 may be substantially coincident with the proximal coil 216 and the distal coil 218. Alternatively, as shown, the bushing coil 220 may extend further proximally than the proximal coil 216. This allows the bushing coil 220 to fill in more of the annular space even in portions where the proximal coil 216 cannot fill. That is, due to the tapered profile of the distal core 203, some more proximal sections of the annular space do not match the proximal coil 216 and the liner coil 220, but may still be filled by further extended proximal sections of the liner coil 220. Preferably, the liner coil 220 extends along a majority of the length of the tube 204. For example, the length of the liner coil 220 may be at least about 60% of the length of the tube 204, or at least about 75% of the length of the tube 204, or at least about 80% of the length of the tube 204, or at least about 85% of the length of the tube 204.

In a preferred embodiment, the proximal coil 216 and the distal coil 218 are each wound in a first direction, while the bushing coil 220 is counter-wound in an opposite second direction. This advantageously limits the interlocking and bonding of the bushing coil 220 with either the proximal coil 216 or the distal coil 218. The liner coil 220 may also have a pitch that is different (e.g., narrower) than the pitch (pitch) of the proximal coil 216 or the distal coil 216. For example, the proximal coil 216 and/or the distal coil 218 may have a pitch of about 0.002 inches to about 0.008 inches or a pitch of about 0.003 inches to about 0.007 inches, while the bushing coil 220 may have a pitch of about 0.001 inches to about 0.006 inches or a pitch of about 0.002 inches to about 0.005 inches.

Preferably, the proximal coil 216, distal coil 218, and bushing coil 220 are configured to fill a majority of the volume of the annular space between the distal core 203 and the tube 204. For example, the proximal coil 216, distal coil 218, and bushing coil 220 may be configured to fill approximately 20% or more, 35% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even up to about 90% or more of the volume of the annular space. Of course, other conventional guidewires may include joints or bushings that fill most of the annular space at the particular location of the guidewire where they are located. However, such joints and bushings fill a relatively small volume of the entire annular space when considering the entire length of the outer pipe.

The centering mechanism principles described herein may be used with other structural configurations to provide beneficial centering effects. For example, while the above embodiments describe various centering mechanisms having a core as the "inner member" and a micro-machined tube as the "outer member", other structures may additionally or alternatively be used as the outer and/or inner members with one or more of the described centering mechanisms.

For example, the inner member may be a wire (such as an abrasive core as described above), a tube (e.g., a metal or polymer hypotube or a metal or polymer micro-machined tube), a braid, or a coil. By way of further example, the outer member may be a tube (e.g., a metal or polymer hypotube or a metal or polymer micromachined tube), a braid, a coil, or a polymer tube filled with a braid or coil. The centering mechanism may include a coil assembly as described above, or may additionally or alternatively include other structure within the outer member for providing inner member centering. For example, one or more of the coils 216, 218, 220 may be replaced by one or more tubes (e.g., metal or polymer hypotubes or metal or polymer micro-machined tubes), braided segments, or stacked ring sets.

Fig. 4 shows the tube 204 separate from the core 202 and some other components of the device. Tube 204 extends between a proximal end 222 and a distal end 224. The fenestration 206 formed in the tube 204 may be made according to a variety of cut patterns. Preferably, the overall effect of the fenestrations provides a flexibility gradient between the tubes 204, with more flexibility added closer to the distal end 224. Generally, greater flexibility may be provided by removing more stock material (such as by increasing the depth of the cuts, reducing the space between adjacent cuts, and/or reducing the number of axially extending beams 226 connecting each circumferentially extending ring 228).

For example, the illustrated embodiment may include a three beam section 230 (three beams connecting each adjacent pair of rings), the three beam section 230 transitioning to a double beam section 232 (two beams connecting each adjacent pair of rings), the double beam section 232 transitioning to a single beam section 234 (a single beam connecting each adjacent pair of rings). Within each of these sections, the depth of the cuts and/or the spacing of the cuts may also be adjusted to provide a smooth intra-and inter-sectional flexibility gradient. For example, the double beam section 232 may have a decreasing distance between the cuts as it progresses toward the distal end 224. It may then transition to the single beam section 234, and then the single beam section 234 itself includes progressively decreasing distances between the cutouts as it progresses toward the distal end 224.

For example, the single beam section 234 may have a length of about 0.5cm to about 3cm, or about 0.75cm to about 2 cm. For example, the dual beam section 232 may have a length of about 4cm to about 16cm, or a length of about 6cm to about 12 cm. For example, the three beam section 230 may have a length of about 12cm to about 36cm, or a length of about 18cm to about 30 cm. In other words, the triple beam section 230 may be about 2 to 5 times longer than the double beam section 232, and the double beam section 232 may be about 2 to 5 times longer than the single beam section 234. It has been found that designing the tube 204 with these ratios of slit/beam sections provides an effective balance of axial, lateral and torsional stiffness for most applications.

The tube 204 may also include a distal-most section 235 having a double beam pattern. Preferably, the segment is relatively short, for example about 0.5cm or less, or about 0.25cm or less, or about 0.15cm or less. Providing a relatively shorter double beam section at section 235 provides an increased surface area for bonding to be applied to the bonding material at or near the distal end 224 of tube 204, allowing for a stronger coupling between the distal end 224 and any internal components bonded to the distal end 224.

Certain sections of the tube 204 may have rotationally offset cuts to avoid the formation of any preferred curved planes. For example, an angular offset may be applied after each cut or series of cuts such that the overall resulting pattern of beams 226 in tube 204 are not aligned in a manner that forms a preferred plane of curvature.

Other sections of the tube 204 may include preferred planes of curvature. For example, the single beam sections 234 may be aligned as shown in fig. 4, with each beam offset from the front beam by about 180 °. These beams may also be aligned with the bending plane of the flat distal section 211 of the core. Fig. 5 shows in cross-section how the beams 226 of the single beam section 234 are preferably aligned in the same plane as the flat, wider section of the distal section 211 of the core.

Additional exemplary embodiments

The following embodiments include different combinations of features of the intravascular devices described herein. Embodiments described herein may include features, characteristics (e.g., components, members, elements, parts, and/or sections) described in other embodiments described herein. Thus, various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features in relation to particular embodiments of the present disclosure should not be construed as limiting the application or inclusion of such features to particular embodiments. Rather, it should be understood that other embodiments may include such features.

Example 1: an intravascular device comprising: a core having a proximal section and a distal section; and a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and a distal section of the core disposed within the outer tube, wherein an outer diameter of the outer tube is greater than an outer diameter of a proximal section of the core.

Example 2: the apparatus of embodiment 1, further comprising: a distal coil surrounding a portion of the distal section of the core; a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and a bushing coil disposed over at least a portion of one or both of the distal coil and the proximal coil, wherein the distal coil, the proximal coil, and the bushing coil fill at least a portion of the annular space.

Example 3: the device of embodiment 2, wherein the distal coil is more radiopaque than stainless steel.

Example 4: the apparatus of embodiments 2 or 3, wherein the distal coil is more radiopaque than the proximal coil.

Example 5: the device of any of embodiments 2-4, wherein the distal coil has a wire size of about 0.006 inches or less.

Example 6: the device of any of embodiments 2-5, wherein the proximal coil has a wire size of about 0.006 inches or less.

Example 7: the apparatus of any of embodiments 2-6 wherein the wire size of the liner coil is about 0.006 inches or less.

Example 8: the device of any of embodiments 2-7, wherein the bushing coil extends proximally further than the proximal coil.

Example 9: the apparatus of any of embodiments 2-8, wherein the length of the liner coil is at least about 60% of the length of the tube.

Example 10: the apparatus of any of embodiments 2-9, wherein at least one of the proximal coil, the distal coil, and the hub coil is wound in an opposite direction from the other coils.

Example 11: the device of embodiment 10, wherein the proximal coil and the distal coil are each wound in a first direction and the bushing coil is counter-wound in an opposite second direction.

Example 12: the apparatus of any of embodiments 2-11, wherein the bushing coil has a pitch that is less than a pitch of the proximal coil and/or the distal coil.

Example 13: the device of any of embodiments 2-12, wherein the proximal coil, the distal coil, and the bushing coil fill 15% or more of the volume of the annular space.

Example 14: the device of any of embodiments 1-13, wherein the outer diameter of the outer tube is about 10% or greater than the outer diameter of the proximal section of the core.

Example 15: the device of any of embodiments 1-14, further comprising a bushing disposed at a proximal end of the outer tube to assist in coupling the outer tube to the core.

Example 16: the device of embodiment 15, wherein the bushing comprises a chamfered or beveled proximal edge.

Example 17: the device of any of embodiments 1-16, wherein the tube comprises at least one of a three-beam section, a two-beam section, and a single-beam section.

Example 18: the device of any of embodiments 1-17, wherein the flat distal section of the core has a preferred plane of curvature, and wherein the preferred plane of curvature of the flat distal section is aligned with a preferred plane of curvature of a portion of the tube covering the flat distal section.

Example 19: an intravascular device, a core having a proximal section and a distal section; a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and the distal section of the core disposed within the outer tube; a distal coil surrounding a portion of the distal section of the core; a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and a bushing coil disposed over at least a portion of one or both of the distal coil and the proximal coil, wherein the distal coil, the proximal coil, and the bushing coil fill at least a portion of the annular space.

Example 20: an intravascular device comprising: a core having a proximal section and a distal section; a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and a distal section of the core disposed within the outer tube, wherein an outer diameter of the outer tube is greater than an outer diameter of a proximal section of the core; a distal coil surrounding a portion of the distal section of the core; a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and a liner coil disposed over the distal coil and the proximal coil, wherein at least one of the proximal coil, the distal coil, and the liner coil is wound in an opposite direction to the other coils, and wherein the distal coil, the proximal coil, and the liner coil fill 15% or more of the volume of the annular space.

Conclusion

Although certain embodiments of the present disclosure have been described in detail with reference to particular configurations, parameters, components, elements, and the like, such descriptions are illustrative and should not be construed as limiting the scope of the claimed invention.

Furthermore, it should be understood that for any given element or component of the described embodiments, any possible alternatives listed for that element or component may generally be used alone or in combination with one another, unless implicitly or explicitly stated otherwise.

In addition, unless otherwise indicated, numbers expressing quantities, compositions, distances, or other measurements used in the specification and claims are to be understood as being optionally modified by the term "about" or its synonyms. When the terms "about," "substantially," and the like are used in conjunction with a stated amount, value, or condition, they can be considered to refer to an amount, value, or condition that deviates from the stated amount, value, or condition by less than 20%, less than 10%, less than 5%, or less than 1%. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Any headings and sub-headings used herein are for organizational purposes only and are not meant to limit the scope of the description or the claims.

It will also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" do not exclude a plurality unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a single reference (e.g., "a widget") can also include two or more such references.

Claims (20)

1. An intravascular device comprising:

a core having a proximal section and a distal section;

a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and the distal section of the core disposed within the outer tube,

wherein an outer diameter of the outer tube is greater than an outer diameter of the proximal section of the core.

2. The apparatus of claim 1, further comprising:

a distal coil surrounding a portion of the distal section of the core;

a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and

a bushing coil disposed over at least a portion of one or both of the distal coil and the proximal coil,

wherein the distal coil, the proximal coil, and the bushing coil fill at least a portion of the annular space.

3. The device of claim 2, wherein the distal coil is more radiopaque than stainless steel.

4. The apparatus of claim 2, wherein the distal coil is more radiopaque than the proximal coil.

5. The device of claim 2, wherein the distal coil has a wire size of about 0.006 inches or less.

6. The device of claim 2, wherein the proximal coil has a wire size of about 0.006 inches or less.

7. The apparatus of claim 2, wherein the wire size of the liner coil is about 0.006 inches or less.

8. The device of claim 2, wherein the bushing coil extends proximally further than the proximal coil.

9. The apparatus of claim 2, wherein the length of the liner coil is at least about 60% of the length of the tube.

10. The device of claim 2, wherein at least one of the proximal coil, the distal coil, and the bushing coil is wound in an opposite direction from the other coils.

11. The device of claim 10, wherein the proximal coil and the distal coil are each wound in a first direction and the bushing coil is counter-wound in an opposite second direction.

12. The apparatus of claim 2, wherein the bushing coil has a pitch that is less than a pitch of the proximal coil and/or the distal coil.

13. The apparatus of claim 2, wherein the proximal coil, the distal coil, and the bushing coil fill 15% or more of the volume of the annular space.

14. The device of claim 1, wherein the outer diameter of the outer tube is about 10% or greater than the outer diameter of the proximal section of the core.

15. The device of claim 1, further comprising a bushing disposed at a proximal end of the outer tube to assist in coupling the outer tube to the core.

16. The device of claim 15, wherein the bushing comprises a chamfered or beveled proximal edge.

17. The device of claim 1, wherein the tube comprises at least one of a three-beam section, a two-beam section, and a single-beam section.

18. The device of claim 1, wherein the flat distal section of the core has a preferred plane of curvature, and wherein the preferred plane of curvature of the flat distal section is aligned with a preferred plane of curvature of a portion of the tube covering the flat distal section.

19. An intravascular device comprising:

a core having a proximal section and a distal section;

a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and a distal section of the core disposed within the outer tube;

a distal coil surrounding a portion of the distal section of the core;

a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and

a bushing coil disposed over at least a portion of one or both of the distal and proximal coils,

wherein the distal coil, the proximal coil, and the bushing coil fill at least a portion of the annular space.

20. An intravascular device comprising:

a core having a proximal section and a distal section;

a slotted outer tube coupled to the core such that a distal section of the core enters and is surrounded by a tube structure, the outer tube and the core defining an annular space between an inner surface of the outer tube and the distal section of the core disposed within the outer tube, wherein an outer diameter of the outer tube is greater than an outer diameter of a proximal section of the core;

a distal coil surrounding a portion of the distal section of the core;

a proximal coil disposed proximal to the distal coil and surrounding a portion of the distal section of the core; and

a bushing coil disposed on the distal coil and the proximal coil,

wherein at least one of the proximal coil, the distal coil, and the bushing coil is wound in an opposite direction to the other coils, an

Wherein the distal coil, the proximal coil, and the bushing coil fill 15% or more of the volume of the annular space.