Patent Description:
A medical catheter defining at least one lumen has been proposed for use with various medical procedures. For example, in some cases, a medical catheter may be used to deliver a medical device and/or composition within vasculature of a patient.

<CIT> describes a multi-layer distal catheter section. <CIT> describes a soft tip catheter. <CIT> describes an intravascular catheter having a multi-layered tip.

In some aspects, this disclosure describes example catheters that each include a push assembly and an elongate body including an inner liner defining an entry port into a lumen of the elongate body and an outer jacket. The push assembly may include an elongate member and an anchor member positioned at a distal end of the elongate member. The elongate member is relatively stiff such that the push assembly may be configured to facilitate introduction of the catheter in vasculature of a patient. When the push assembly is assembled with the elongate body, distal to the entry port, a portion of the push assembly including the anchor member may be positioned between adjacent portions of the inner liner and outer jacket. Proximal to the entry port, a portion of the push assembly may be positioned outside of adjacent portions of the inner liner and outer jacket. In some examples, a proximal portion of the push assembly may be positioned entirely outside of the inner liner and outer jacket. In some examples, the anchor member may have a partial-ring shape and a beveled distal edge and may extend partially around an outer perimeter of the inner liner.

In some examples, a catheter system includes an outer catheter, and the catheter including the push assembly may be an inner catheter that may be introduced into vasculature of a patient through a lumen of the outer catheter. The elongate body may be configured to extend out of a distal opening of the outer catheter to extend through heavy tortuosity or calcification within a body vessel. The elongate body may have a smaller radial profile and may be more flexible than the outer catheter such that it may more easily navigate through heavy tortuosity or calcification within a body vessel than the outer catheter. In some examples, the elongate body may include an atraumatic tip to minimize adverse interactions with patient tissue during advancement of the elongate body within a body vessel.

In some aspects, this disclosure describes example catheters that each include a distal tip portion configured to reduce impact force between the distal tip of the catheter and tissue of a patient as the catheter is advance through vasculature of a patient. The distal tip portion may include a construction that reduces an effective durometer of the tip compared to a more proximal portion of the catheter. For example, the distal tip portion may include a tip outer jacket that includes a material or mixture of materials that has a lower durometer than an outer jacket of a more proximal portion of the catheter. As another example, an inner liner may end proximal of the distal tip, reducing an effective durometer of the distal tip portion.

In some examples, a medical catheter ("catheter") described herein includes a push assembly and an elongate body including an inner liner and an outer jacket. The push assembly includes an elongate member (also referred to herein as a shaft) and an anchor member at a distal end of the push assembly. In some examples, the push assembly includes only one anchor member at the distal end of the push assembly, while in other examples, the push assembly includes a plurality of anchor members. The anchor member is configured to facilitate attachment of the elongate member to the inner liner and outer jacket of the elongate body. The anchor member may be positioned at a distal end of the elongate member.

The outer jacket and the inner liner, alone or in combination with other elements, may form the elongate body, may be a distal portion of the catheter. The elongate body defines at least one lumen through which a medical device (e.g., a catheter, guidewire, filter, stent delivery system, and the like), therapeutic agent, or other element can be introduced into vasculature or other tissue sites of a patient. The inner liner may define an entry port into the lumen. At least a portion of the elongate member of the push assembly may extend proximal of the outer jacket and the inner liner. In examples in which the catheter is part of an intravascular catheter system and is used in conjunction with an outer catheter, the elongate body of the catheter may be used to effectively extend the reach of the outer catheter. For example, the elongate body of the catheter may be fully or partially pushed through a lumen of the outer catheter until the entire or part of the elongate body extends past a distal end of the outer catheter, while the push assembly remains fully or partially within the lumen of the outer catheter. The push assembly has a lower profile than the elongate body, and, as a result, may occupy less space within the outer catheter lumen than the elongate body of the catheter. Thus, the push assembly may both facilitate pushability of the catheter through the outer catheter and/or through vasculature of a patient, while still enabling relatively large medical devices to be introduced through the outer catheter lumen to reach the lumen of the catheter.

In some examples, the catheter described herein may also help delivery to or past a diseased region or the body. For example, a diseased region may include heavy tortuosity and/or calcification and the catheter may be better suited for navigation through such heavy tortuosity and/or calcification than the outer catheter due to its flexibility and lower profile. In some examples, a clinician may push the catheter out of a distal end of the outer catheter upon the approach of the outer catheter to such a region that would be difficult or impossible for the outer catheter to extend through. In some examples, the catheter may be said to "telescope" out of the outer catheter when it is pushed out of a distal end of the outer catheter.

The elongate body, including the inner liner and outer jacket, may define a proximal end. Distal to the proximal end, a portion of the push assembly including the anchor member may be positioned between the inner liner and outer jacket. The anchor member may extend only partially around an outer perimeter of the inner liner. Proximal to the proximal end of the elongate body, a portion of the push assembly proximal to the portion including the anchor member may be positioned outside of the outer jacket.

In some examples, the anchor member may be configured to facilitate manufacture of a catheter. For example, the anchor may define a beveled distal edge to assist with placement of the anchor member, including insertion and advancement of the anchor member between the outer jacket and the inner liner. As another example, the anchor member may define a slot extending from a proximal end of the anchor member and towards a distal end of the anchor member. The slot may facilitate attachment of the elongate member to the anchor member as the slot may be configured such that a distal end of the elongate member may be positioned at least partially within the slot and may be welded to the anchor. The slot may be configured such that welding material may be placed between the anchor member and the elongate member, such as in a gap within the slot between the anchor member and the elongate member when the distal end of the elongate member is positioned at least partially within the slot, such that the welding material may not add to the profile of the push assembly.

In some examples, an inner surface and/or an outer surface of the anchor member may be a non-semicircular surface such as, for example, a surface defining a plurality of notches or waves and/or a textured and/or etched surface. Such a non-circular surface may aid in securing the anchor member between the inner liner and the outer jacket by providing greater surface area that may be bonded to the inner liner and/or outer jacket including, for example, by reflow of material of the inner liner and/or outer jacket.

In some examples, the catheter may include one or more radiopaque markers to facilitate visualization of the catheter during a medical procedure. The one or more radiopaque markers can be located, for example, on the anchor member, on the elongate member, or in any suitable place or combination of places, to assist with visualization and placement of the catheter, with respect to, for example, an outer catheter and/or a target tissue site. In some examples, the anchor is at least partially radiopaque and/or a radiopaque marker is positioned at or near the entry port into the elongate body of the catheter. This radiopaque marker placement may enable a clinician to relatively quickly ascertain the location of the entry port of the lumen of the catheter.

In some examples, the catheter may be configured to facilitate maneuverability. For example, the outer jacket may vary in stiffness along its length, which may help aid maneuverability of the catheter within vasculature of a patient. As another example, a reinforcement member may be positioned between the inner liner and the outer jacket, may be distal to and/or abutting the anchor member, and may aid in the strength and/or maneuverability of the catheter within vasculature of a patient.

In some examples, the elongate member of the push assembly may taper in a distal direction to enable the distal portion of the elongate member to better approximate a profile of the anchor member. By tapering the elongate member instead of forming the entire elongate member to have the lower profile, the proximal portion of the elongate member may still have a size and strength sufficient for pushing the catheter within the vasculature and/or sufficient size for gripping by a user. In some of these examples, as well as some other examples, the elongate member may be a solid member having a round (e.g., circular) cross-section. That is, the elongate member may not define a central lumen or other opening in its cross-section.

In some examples, the catheter may facilitate differentiation from other devices used in conjunction with the catheter and/or between elements of the catheter. For example, a sleeve may surround at least a portion of the elongate member, such as a portion proximal to the anchor member. In some examples, the sleeve may be a different color than the elongate member, the elongate body, a guidewire, and/or other devices used with the catheter in order to help visually distinguish the sleeve. The sleeve can also include other features to help facilitate usage of the sleeve. For example, the sleeve may include one or more bands including one or more partial cuts extending partially through a radial thickness of the sleeve and/or one or more markers. In some examples, the sleeve may include a textured surface. In some examples, partial cuts and/or a textured surface may aid in tactile differentiation of the sleeve from other components. In some examples, one or more bands including one or more partial cuts and/or markers may aid in visual differentiation of the sleeve. Visual and/or tactile differentiation of the sleeve may enable the elongate member to be discerned from other elements including, for example, an outer catheter, a guidewire, or other delivery devices or components in use with the catheter described herein.

<FIG> is a conceptual side view of an example catheter <NUM>, which includes an elongate body <NUM>, a push assembly <NUM>, and a handle <NUM>. <FIG> is a conceptual cross-sectional view of a portion of catheter <NUM> of <FIG> and an outer catheter <NUM>. Catheter <NUM> defines a longitudinal axis X. Elongate body <NUM> includes an inner liner <NUM> and an outer jacket <NUM>. As shown in <FIG>, elongate body <NUM> may define a proximal end <NUM> and a distal end <NUM>.

In some examples, catheter <NUM> may be part of an assembly that includes an outer catheter <NUM> defining a lumen <NUM>, through which catheter <NUM> may be introduced in order to access, for example, a distal target site within vasculature of a patient. Thus, at least a portion of outer catheter <NUM> may be configured to surround catheter <NUM>. Outer catheter <NUM> may further define distal opening <NUM> and, in some examples, at least a portion of catheter <NUM> may be configured to extend through distal opening <NUM> and distally of outer catheter <NUM>, as shown in <FIG>. For example, catheter <NUM> may be configured to extend out of distal opening <NUM> of outer catheter <NUM> to extend through heavy tortuosity or calcification within a body vessel. Catheter <NUM> may have a smaller radial profile and may be more flexible than outer catheter <NUM> such that it may more easily navigate through heavy tortuosity or calcification within a body vessel than outer catheter <NUM>.

In some examples, an outer radial profile of elongate body <NUM> of catheter <NUM> may be similar in a radial shape and/or size of at least a distal portion of lumen <NUM> of outer catheter <NUM> such that catheter <NUM> may fit relatively snugly inside of outer catheter <NUM> when elongate body is at least partially within outer catheter <NUM>. This may help to define a relatively smooth transition between elongate body <NUM> and outer catheter <NUM> when only a portion of elongate body <NUM> extends distally of distal opening <NUM> of outer catheter <NUM> and another portion remains within lumen <NUM> of outer catheter <NUM> and/or when a proximal end of elongate body <NUM> abuts a distal end of outer catheter <NUM>. This relatively smooth transition and/or snug fit may provide certain advantages. For example, fluids may be easier to deliver through the lumen <NUM> of outer catheter <NUM> and the lumen <NUM> of elongate body <NUM> without leakage. As an additional example, devices and/or other elements may be easier to advance from lumen <NUM> of outer catheter <NUM> to lumen <NUM> of elongate body <NUM> because the transition between lumen <NUM> and lumen <NUM> may be relatively smooth such that components being delivered may not get caught at a transition from lumen <NUM> to lumen <NUM>.

Although catheter <NUM> is shown as extending out distal opening <NUM> of outer catheter <NUM> such that proximal end <NUM> of elongate body <NUM> is distal to distal opening <NUM>, in some medical procedures, catheter <NUM> may be positioned relative to outer catheter <NUM> such that proximal end <NUM> of elongate body <NUM> is proximate to distal opening <NUM>. For example, entry port <NUM> of elongate body <NUM>, described in further detail below, may be positioned within lumen <NUM> of outer catheter <NUM>, such that an interventional medical device or another medical device can be introduced from lumen <NUM> of outer catheter <NUM> into lumen <NUM> of elongate body <NUM> without exiting lumen <NUM>.

In some examples, as shown in <FIG>, catheter <NUM> may include an atraumatic tip <NUM> to minimize adverse interactions with patient tissue during advancement of catheter <NUM> within a body vessel.

Elongate body <NUM> is configured to provide a delivery vessel on catheter <NUM> that may extend distally of outer catheter <NUM> to telescope out of a distal end of outer catheter <NUM> and effectively extend a reach of a catheter within vasculature of a patient and enable delivery of devices, agents, and/or any other suitable elements to target sites that may be difficult for outer catheter <NUM> to reach. In some examples, elongate body <NUM> may include an inner liner <NUM> and outer jacket <NUM> that may provide multiple layers between which push assembly <NUM> may be inserted to attach push assembly <NUM> to elongate body <NUM>. This may provide for a relatively strong attachment between push assembly <NUM> and elongate body <NUM>, as well as maintain relatively smooth outer and inner surfaces of elongate body <NUM> at the portion of elongate body <NUM> attached to push assembly <NUM>.

Inner liner <NUM> of elongate body <NUM> defines lumen <NUM> and outer jacket <NUM> defines lumen <NUM>. In some examples, at least a portion of inner liner <NUM> may be positioned within lumen <NUM> of outer jacket <NUM>. In some examples, inner liner <NUM> may extend within the full length of lumen <NUM> of outer jacket <NUM>. In other examples, however, inner liner <NUM> may terminate prior to a distal end of outer jacket <NUM> or may extend past a distal end of outer jacket <NUM>. Although elongate body <NUM> is shown as a tubular body in <FIG>, elongate body <NUM> may have any suitable configuration.

Inner liner <NUM>, alone or in combination with outer jacket <NUM>, may define entry port <NUM> into lumen <NUM>. Entry port <NUM> may extend from a proximal end <NUM> to a distal end <NUM> along a length of elongate body <NUM>. In some examples, entry port <NUM> may be angled from distal end <NUM> to proximal end <NUM> due to the tapered shape of the elongate body <NUM>. Entry port <NUM> may be formed by skiving at least part of portion <NUM> of elongate body <NUM>. In some examples, entry port <NUM> may have a length, measured from proximal end <NUM> to distal end <NUM> along longitudinal axis X, of about <NUM> centimeters (cm) to about <NUM> (e.g., <NUM> to <NUM> or nearly <NUM> to <NUM>, to the extent permitted by manufacturing tolerances), such as about <NUM> to about <NUM> or about <NUM>. It is believed that a tapered entry port <NUM> having a relatively longer length and being angled from distal end <NUM> to proximal end <NUM> may help contribute to smooth delivery of a medical device (e.g., an interventional medical device) into inner lumen <NUM> of elongate body <NUM> via entry port <NUM> by guiding the medical device into inner lumen <NUM>.

Push assembly <NUM> may be configured to enable a clinician to position elongate body <NUM> with respect to outer catheter <NUM> and/or with respect to patient vasculature. For example, a proximal portion of push assembly <NUM> may be configured to be gripped and moved by the clinician to position (e.g., advance distally or proximally, and/or rotate) elongate body <NUM> within vasculature of a patient. In some examples, push assembly <NUM> may be used to advance elongate body <NUM> with respect to outer catheter <NUM> to advance elongate body <NUM> within outer catheter <NUM> and/or extend all or a portion of elongate body <NUM> distal of outer catheter <NUM> to access vasculature distal to outer catheter <NUM>. Push assembly <NUM> may include any suitable length. In some examples, a length of push assembly <NUM> may be approximately <NUM> to approximately <NUM>, such as about <NUM>, measured along longitudinal axis X and from a distal end of handle <NUM> to a distal end <NUM> of anchor or measured from a distal end of handle <NUM> to a distal end of elongated member <NUM>. In some examples, push assembly <NUM> includes an elongate member <NUM> and an anchor member <NUM>. For clarity, a portion of anchor member <NUM>, which is positioned behind inner liner <NUM> in the illustrated view, is shown in phantom. In some examples, elongate member <NUM> may include a distal end <NUM> and anchor member <NUM> may be positioned at distal end <NUM> of elongate member <NUM>. In some examples, push assembly <NUM> may not include any other anchor member at distal end <NUM> other than anchor member <NUM>.

In some examples, at least a portion of push assembly <NUM> is positioned between at least adjacent portions (e.g., radially adjacent portions) of inner liner <NUM> and outer jacket <NUM>. For example, at least a portion of push assembly <NUM> may be positioned radially inward of outer jacket <NUM> and radially outward of inner liner <NUM> such that the portion of push assembly <NUM> is between outer jacket <NUM> and inner liner <NUM>. In some examples, the portion of push assembly <NUM> between inner liner <NUM> and outer jacket <NUM> may have a length of approximately <NUM>. Positioning at least a portion of push assembly <NUM> between portions of inner liner <NUM> and outer jacket <NUM> may aid in mechanically connecting push assembly <NUM> and elongate body <NUM> in a manner that enables push assembly <NUM> to transmit pushing forces and, in some examples, rotational forces, to elongate body <NUM>. In addition, positioning at least a portion of push assembly <NUM> between inner liner <NUM> and outer jacket <NUM> may enable elongate body <NUM> to have relatively smooth inner and outer surfaces at the portion of elongate body <NUM> attached to push assembly <NUM>.

In some examples, elongate body <NUM> may include a tapered portion <NUM>. For example, portions of inner liner <NUM> and outer jacket <NUM>, as shown in <FIG>, corresponding to tapered portion <NUM> of elongate body <NUM> may be tapered in a proximal direction. The tapering of elongate body <NUM> at tapered portion <NUM> may enable elongate body <NUM> to more easily be retracted into outer catheter <NUM>. For example, during or after use of catheter <NUM>, a clinician may desire to retract at least a portion of elongate body <NUM> within outer catheter <NUM> by retracting push assembly <NUM> proximally with respect to outer catheter <NUM>. Tapered portion <NUM> may allow for smoother entry of elongate body <NUM> into outer catheter <NUM>.

Additionally, the tapered shape of tapered portion <NUM> may be configured facilitate attachment of push assembly <NUM> to elongate body <NUM>. For example, the tapered shape may allow for anchor member <NUM> to support entry port <NUM> while also allowing a portion of elongate member <NUM> proximal to anchor member <NUM> to be positioned between inner liner <NUM> and outer jacket <NUM>, which may increase bond tensile strength between the push assembly <NUM> and the elongate body <NUM>. The bond tensile strength between push assembly <NUM> and elongate body <NUM> may decrease with a shorter length of elongate member <NUM> positioned between inner liner <NUM> and outer jacket <NUM>. Thus, if only anchor member <NUM> (and not elongate member <NUM>) was positioned between inner liner <NUM> and outer jacket <NUM>, then the bond tensile strength between push assembly <NUM> and elongate body <NUM> may decrease. The decreased bond tensile strength may adversely affect the ability for push assembly <NUM> to transfer pushing and/or rotational forces to elongate body <NUM> without compromising the mechanical connection between push assembly <NUM> and elongate body <NUM>.

Further, because a distal portion of elongate member <NUM> may be relatively flexible (compared to a more proximal portion of elongate member <NUM>), as described in further detail below, positioning the distal portion of elongate member <NUM> between inner liner <NUM> and outer jacket <NUM> may help prevent the junction of push assembly <NUM> and elongate body <NUM> from being undesirably stiff.

In some examples, distal to proximal end <NUM> of elongate body <NUM>, a portion of push assembly <NUM> is positioned between adjacent portions of inner liner <NUM> and outer jacket <NUM>. Proximal to proximal end <NUM> of elongate body <NUM>, a portion of push assembly <NUM> is positioned outside of outer jacket <NUM> and inner liner <NUM>. The portion of push assembly <NUM> positioned between adjacent portions of inner liner <NUM> and outer jacket <NUM> may comprise anchor member <NUM>. The portion of push assembly <NUM> positioned outside of outer jacket <NUM> and inner liner <NUM> may be proximal to the portion positioned between adjacent portions of inner liner <NUM> and outer jacket <NUM>.

Anchor member <NUM> may have any suitable shape and size. In some examples, at least an outer surface of anchor member <NUM> may define a partial-ring shape as shown in further detail below with reference to <FIG>. In other examples, however, anchor member <NUM> may define other shapes. The partial-ring shape of anchor member <NUM> may provide one or more advantages. For example, the partial-ring shape may provide support to inner liner <NUM> and outer jacket <NUM> to prevent collapse of proximal ends of inner liner <NUM> and outer jacket <NUM> and thus help maintain the open state of entry port <NUM> into lumen <NUM> defined by inner liner <NUM> such that other catheters or devices may be inserted into lumen <NUM>.

In some examples, and as described in further detail below with respect to <FIG>, anchor member <NUM> may have an inner perimeter that is less than the outer perimeter of inner liner <NUM> and anchor member <NUM> may extend only partially around an outer perimeter of inner liner <NUM>. For example, anchor member <NUM> may extend about <NUM> degrees to about <NUM> degrees around an outer perimeter of inner liner <NUM>. More particularly, in some examples, anchor member <NUM> may extend about <NUM> degrees around the outer perimeter of inner liner <NUM>. In some examples, anchor member <NUM> is radiopaque, and extending only partially about the outer perimeter of inner liner <NUM> may enable anchor member <NUM> to indicate a rotational orientation (e.g., rotational position about longitudinal axis X) of elongate body <NUM> (e.g., entry port <NUM>) within vasculature of a patient. This may enable a clinician to better position catheter <NUM> relative to outer catheter <NUM>.

In addition, extending only partially about the outer perimeter of inner liner <NUM> may enable anchor member <NUM> to be positioned within tapered portion <NUM> of elongate body <NUM>. This may enable anchor member <NUM> to be positioned at entry port <NUM> to indicate the location thereof, and may also enable anchor member <NUM> to provide structural support to tapered portions of the inner liner <NUM> and outer jacket <NUM>. A full-ring shape would not be able to be located within the tapered portion <NUM> of elongate body <NUM> but instead would need to be located distal to the tapered portion <NUM> and thus distal to the entry port <NUM> in order to fit between inner liner <NUM> and outer jacket <NUM> without being exposed and would thus not be able to include a marker to indicate a location of the entry port <NUM>.

In some examples, however, as shown in <FIG>, a proximal end of anchor member <NUM> is positioned proximate to the distal end <NUM> of entry port <NUM>. For example, a proximal end of anchor member <NUM> may be aligned with distal end <NUM> of entry port <NUM>, such that anchor member <NUM> is fully positioned within the portion of elongate body <NUM> defining a circular outer perimeter in cross-section. As another example, a proximal end of anchor member <NUM> may not be exactly aligned with distal end <NUM> of entry port <NUM>, but within <NUM> millimeters (mm), such as within <NUM> or less, of distal end <NUM> of entry port <NUM> in a proximal or a distal direction. In these examples, a substantial length of that anchor member <NUM> is positioned within the portion of elongate body <NUM> defining a circular outer perimeter in cross-section.

This partial-ring shape of anchor member <NUM> may also be advantageous over a full-ring shape because it may be less likely to cause inner liner <NUM> to bunch during insertion of anchor member <NUM> between outer jacket <NUM> and inner liner <NUM> because anchor member <NUM> does not extend fully about an outer perimeter of inner liner <NUM>.

In some examples anchor member <NUM> may define a beveled distal edge <NUM>. Beveled distal edge <NUM> may allow anchor member <NUM> to more easily be inserted and advanced between inner liner <NUM> and outer jacket <NUM> than examples in which an anchor member has a straight edge. For example, beveled distal edge <NUM> may enable anchor member <NUM> to be more easily inserted between inner liner <NUM> and outer jacket <NUM> by providing a narrow profile of anchor member <NUM> at distal end <NUM>, which leads anchor member <NUM> into the space between inner liner <NUM> and outer jacket <NUM>. Additionally, beveled distal edge <NUM> may provide a smooth distal profile of anchor member <NUM> that enables less resistance to advancement of anchor member <NUM> between and with respect to inner liner <NUM> and outer jacket <NUM> than a profile including a straight edge and/or sharp corners which may be more likely to catch on inner liner <NUM> and/or outer jacket <NUM>.

Inner liner <NUM> may be formed from any suitable material, such as, but not limited to polytetrafluorethylene (PTFE). In some examples, outer jacket <NUM> may comprise one or more polymers. In some examples, outer jacket <NUM> may have a hydrophilic coating. For example, the hydrophilic coating may be positioned over the entire outer surface of outer jacket <NUM> or only along a portion of outer jacket, such as only along a distal-most portion of outer jacket <NUM>. In some examples, a hydrophilic coating is positioned over the distal-most approximately <NUM> to approximately <NUM> of outer jacket <NUM> (e.g., the distal-most <NUM> to <NUM> to the extent permitted by manufacturing tolerances), such as the distal-most approximately <NUM> to approximately <NUM> of outer jacket <NUM>, or the distal-most approximately <NUM> of outer jacket <NUM>, the distances being measured from distal end of outer jacket <NUM>, which may correspond to distal end <NUM> of elongate body <NUM> in some examples.

In some examples, outer jacket <NUM> may include multiple sections having different stiffnesses. For example, outer jacket <NUM> may include a proximal section, corresponding with portion <NUM> of catheter <NUM>, and a distal section, corresponding with portion <NUM> of catheter <NUM> (shown in <FIG>), that is distal to the proximal section. In some examples, the proximal section may be approximately <NUM> to approximately <NUM> long, such as approximately <NUM> long or approximately <NUM> long. In some examples, the distal section may be approximately <NUM> to approximately <NUM> long, such as approximately <NUM> long to approximately <NUM> long, or approximately <NUM> long. The lengths may be measured along longitudinal axis X.

The distal section of outer jacket <NUM> may have a different stiffness than the proximal section. For example, the distal section may have a stiffness that is greater than a stiffness of the proximal section. In other examples, the distal section may have a stiffness that is less than the proximal section. Outer jacket <NUM> having a more stiff proximal section (relative to a distal outer jacket section) may help maintain the integrity of the proximal portion of inner lumen <NUM> of elongate body <NUM>, which may aid in introduction of medical devices into lumen <NUM> from entry port <NUM> without adversely impact the navigability of catheter <NUM> through vasculature of a patient. For example, outer jacket <NUM> having a more stiff proximal section may help distal end <NUM> of entry port <NUM> and a proximal-most portion of elongate body <NUM> resist deformation to help maintain lumenal integrity.

Outer jacket <NUM> may include any suitable number of sections having any suitable stiffnesses according to particular needs. In some examples, sections of outer jacket <NUM> may include different types of polymers, with a stiffer section comprising a stiffer polymer than a more flexible section comprising a softer polymer. In some examples, outer jacket <NUM> having multiple sections with different stiffnesses may provide improved functionality of outer jacket <NUM> including, for example, improved maneuverability of outer jacket <NUM> through the vasculature. For example, the distal section may have a stiffness that is less than a stiffness of the proximal section, which may allow the distal section improved flexibility for navigation through the vasculature.

In some examples, catheter <NUM> may further include a reinforcement member <NUM> positioned between a portion of inner liner <NUM> and a portion of outer jacket <NUM>. For clarity, a portion of reinforcement member <NUM>, which is positioned behind inner liner <NUM> in the illustrated view, is shown in phantom. Reinforcement member <NUM> may be any suitable structure configured to provide structural support to elongate body <NUM> and, in some examples, increase the structural integrity of elongate body <NUM>. For example, reinforcement member <NUM> may comprise a metal coil, a metal braid, or a combination thereof. In some examples, a distal end <NUM> of anchor member <NUM> may be positioned proximal to and spaced from reinforcement member <NUM>, such that there is a gap between distal end <NUM> of anchor member <NUM> and a proximal end <NUM> of reinforcement member <NUM>. Example gaps include, for example, gaps less than or equal to <NUM>, such as about <NUM> or less than <NUM>, measured along longitudinal axis X. In other examples, anchor member <NUM> may contact (e.g., abut) reinforcement member <NUM>, e.g., distal end <NUM> of anchor member <NUM> may contact proximal end <NUM> of reinforcement member <NUM>. In yet other examples, anchor member <NUM> and reinforcement member <NUM> may overlap in the longitudinal direction, e.g., by a length of about <NUM> or less, such as about <NUM> or less.

Anchor member <NUM> at distal end <NUM> of elongate member <NUM> may increase a surface area of a distal portion of push assembly <NUM> relative to examples of push assemblies including only elongate member <NUM> without anchor member <NUM>, which may provide certain advantages. For example, the increased surface area at the distal portion of push assembly <NUM> provided by anchor member <NUM> may improve tensile strength of catheter <NUM> by strengthening the bond between push assembly <NUM> and elongate body <NUM>. Additionally, the increased surface area at the distal portion of push assembly <NUM> provided by anchor member <NUM> may help prevent protrusion of elongate member <NUM> through outer jacket <NUM> when elongate member <NUM> is under compression, i.e., when a pushing force is applied to a proximal portion of elongate member <NUM> as catheter <NUM> is advanced through vasculature of a patient. For example, in examples without anchor member <NUM>, distal end <NUM> of elongate member <NUM> may pierce outer jacket <NUM> due to the relatively small surface area of distal end <NUM> of elongate member <NUM>. Anchor member <NUM>, however, helps distribute the pushing force and minimize any pressure points at the distal end of push assembly <NUM>. Additionally, anchor member <NUM> may help avoid bending of distal end <NUM> of elongate member <NUM> under outer jacket <NUM> by providing reinforcement to distal end <NUM> of elongate member <NUM>.

<FIG> are conceptual cross-sectional views of an example elongate member <NUM> of push assembly <NUM> of catheter <NUM> of <FIG> and <FIG> taken along lines <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, respectively, in <FIG>. Although lines <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> are shown as intersecting multiple elements of catheter <NUM> in <FIG>, for clarity, <FIG> show only the cross-section of elongate member <NUM>. As shown, elongate member <NUM> may taper in a distal direction. For example, in some examples and as shown in the illustrated example, a greatest cross-sectional dimension of elongate member <NUM> along line <NUM>-<NUM> may be smaller than a greatest cross-sectional dimension of elongate member <NUM> along line <NUM>-<NUM> and a greatest cross-sectional dimension of elongate member <NUM> along line <NUM>-<NUM>. In some examples and as shown in the illustrated example, a greatest cross-sectional dimension of elongate member <NUM> along line <NUM>-<NUM> may be smaller than a greatest cross-sectional dimension of elongate member <NUM> along line <NUM>-<NUM>. A transition between the cross-sections illustrated in <FIG> may be stepwise, defined by a discrete tapered section, or defined by a substantially constant tapered section.

In some examples, a cross-section of a proximal portion of elongate member <NUM>, such as the cross-section along line <NUM>-<NUM>, may be round (e.g., circular). In some examples, this proximal portion of elongate member <NUM> having the round cross-section may include a proximal-most portion of elongate member <NUM> including a proximal end of elongate member <NUM>. In addition, in some examples, the proximal portion of elongate member <NUM>, the configuration of which may be represented by the cross-section along line <NUM>-<NUM>, may be both round in cross-section and solid (e.g., not hollow or defining any lumens). Elongate member <NUM> having a proximal portion that is solid and round in cross-section may exhibit a better push force transmission along catheter <NUM>, e.g., relative to an elongate body that has a proximal portion that is a hollow in cross-section and/or non-round (e.g., rectangular) in cross-section.

In some examples, a greatest cross-sectional dimension of the proximal portion of elongate member <NUM>, e.g., as shown at line <NUM>-<NUM>, is approximately <NUM> to approximately <NUM>, such as approximately <NUM> to approximately <NUM>. However, other cross-sectional dimensions of elongate member <NUM> may be used in other examples.

In some examples, as in the illustrated example, a portion of elongate member <NUM> having a circular cross section may be proximal to a portion of elongate member <NUM> having a D-shaped cross-section. The portions of elongate member <NUM> having the D-shaped cross-sections may define a smaller profile than the proximal portion of elongate member <NUM> defining the round (e.g., circular) cross-section, such that the portions of elongate member <NUM> defining the D-shaped cross-sections may define the "tapered" portions of elongate member <NUM>. For example, a cross-section of an intermediate and/or a distal portion of elongate member <NUM>, such as the cross-section along line <NUM>-<NUM> or line <NUM>-<NUM>, may be D-shaped. In these examples, one half of elongate member <NUM> in cross-section may be substantially flat (e.g., planar to extent permitted by manufacturing tolerances) and the other longitudinal half of elongate member <NUM> in cross-section may be round (e.g., semi-circular).

In examples in which a distal portion of elongate member <NUM> tapers in a distal direction, a first section of the distal portion may define a first D-shaped cross section having a first cross-sectional area, e.g., a shown in <FIG>, and a second section of the distal portion distal to the first section may define a second D-shaped cross section having a second cross-sectional area, where the second cross-sectional area is less than the first cross-sectional area.

The difference in cross-sectional area may be due to, for example, a profile height of elongate member <NUM> in the first and second sections of the distal portion. In some examples, a D-shaped cross-section along line <NUM>-<NUM> may include profile height (e.g., from the flat surface of the "D" to the crest of the curved surface of the "D") of approximately <NUM> to about <NUM>, such as approximately <NUM> to approximately <NUM>. In some examples, a D-shaped cross-section along line <NUM>-<NUM> is less than the profile height along line <NUM>-<NUM>, and may include profile height of approximately <NUM> and <NUM>. Other profile heights may be used in other examples and may depend on various factors, such as a size of lumen <NUM> or anchor member <NUM>. The profile height at the distal-most section of the distal portion of elongate member <NUM> may be selected such that when elongate member <NUM> is mechanically connected to anchor member <NUM>, elongate member <NUM> does not protrude from anchor member <NUM> in the cross-sectional dimension (orthogonal to longitudinal axis X) or protrudes a relatively minimal amount from anchor member <NUM> to reduce occupying space that limits the cross-sectional size of lumen <NUM>.

In some examples, a length of a proximal portion elongate member <NUM> having a circular cross section as illustrated in <FIG> may be approximately <NUM> to approximately <NUM>, such as approximately <NUM> to approximately <NUM>, or approximately <NUM> or approximately <NUM>. In some examples, the tapered portion of elongate member <NUM> adjacent to the proximal portion and extending to a distal end of elongate member <NUM> may have a length between approximately <NUM> to approximately <NUM>, such as approximately <NUM>.

In some examples, a length of elongate member <NUM> having a cross section substantially as illustrated along line <NUM>-<NUM> may be between approximately <NUM> to approximately <NUM>, such as approximately <NUM>. The cross-section along line <NUM>-<NUM> may be selected to enable elongate member <NUM> to be positioned between at least adjacent portions of inner liner <NUM> and outer jacket <NUM> and provide structural support to entry port <NUM>.

In addition, in some examples (which may be combined with the foregoing dimensions), a length of elongate member <NUM> having a cross-section substantially as illustrated along line <NUM>-<NUM> may be between approximately <NUM> to approximately <NUM>, such as approximately <NUM>. The cross-section along line <NUM>-<NUM> may be selected to enable elongate member <NUM> to be positioned between at least adjacent portions of inner liner <NUM> and outer jacket <NUM> without obstructing inner lumen <NUM> of elongate body <NUM>. In some examples, the distal-most section of elongate member <NUM> including a distal end of elongate member <NUM>, e.g., represented by the cross-section shown in <FIG>, may be selected to enable the distal portion of elongate member <NUM> to be flexible enough to be moved out of the way of a medical device that is being introduced into lumen <NUM> of elongated body <NUM> via entry port <NUM>. As the medical device is pushed into lumen <NUM>, elongate member <NUM> may inadvertently wrap around the medical device due to the manner in which it extends through outer catheter <NUM>. This can be referred to as "wire wrap. " The relatively flexible distal portion of elongate member <NUM> may enable the medical device to push past any wrapped sections of elongate member <NUM> and avoid adverse impacts to medical device delivery attributable to wire wrap.

In some examples, the cross-section along line <NUM>-<NUM> may be selected to substantially match a thickness of anchor member <NUM>. This provide a smoother profile at the juncture of elongate member <NUM> and anchor member <NUM>, which may result in a smoother profile of entry port <NUM> and lumen <NUM>.

In some examples, a cross-section of elongate member <NUM> may be flat or substantially flat on one side (such as D-shaped) or on both sides at a portion that is distal to a portion having a circular cross section. A cross-section of elongate member <NUM> may have any suitable size and/or shape according to particular needs. In addition, elongate member <NUM> may be tapered using nay suitable technique. In some examples, the tapered cross-section of elongate member <NUM> may be defined by an abrasive processing, such as grinding, sanding, or grit blasting. In some examples, the abrasive processing to form the taper of elongate member <NUM> may form at least one rough surface on elongate member. The at least one rough surface may increase the surface area of elongate member <NUM>. The increased surface area may improve adhesion of a polymeric material, such as PTFE, and decrease delamination of the polymeric material, for example, during use of catheter <NUM>. The polymeric material may be, for example, the material used to form inner liner <NUM> and/or outer jacket <NUM>.

Elongate member <NUM> being tapered in a distal direction may provide particular advantages in some cases. For example, a proximal portion of elongate member <NUM> having a solid round profile may have greater cross sectional area and mechanical integrity compared to an elongate member having a different profile, such as a rectangular profile or a hollow profile. In this way, the proximal portion of elongate member <NUM> may better resist kinking in response to a push force better than an elongate member having a different profile, such as a rectangular cross-section and/or a hollow cross-section. For example, a solid <NUM> diameter round profile stainless steel elongate member <NUM> may transfer at least <NUM> gram-force.

Additionally, or alternatively, due to its D-shaped tapered portions (e.g., alone lines <NUM>-<NUM> and <NUM>-<NUM>), elongate member <NUM> may have greater flexibility at a distal portion (relative to non-D-shaped profiles, such as circular profiles), which may help facilitate navigability of catheter <NUM> through vasculature of a patient. The D-shaped profile may also enable elongate member <NUM> to have a similar profile to anchor member <NUM> at a portion of elongate member <NUM> bonded to anchor member <NUM> which may allow push assembly <NUM> to maintain a smoother profile at the juncture of elongate member <NUM> and anchor member <NUM>. This smoother profile at the juncture of elongate member <NUM> and anchor member <NUM> may result in a smoother profile of entry port <NUM> and lumen <NUM>, which may facilitate easier introduction of medical devices into lumen <NUM> via entry port <NUM>.

<FIG> is a conceptual cross-sectional view of catheter <NUM> of <FIG> and <FIG> taken along line <NUM>-<NUM> in <FIG>. <FIG> illustrates a cross-section of inner liner <NUM>, outer jacket <NUM>, and elongate member <NUM> within the section of catheter <NUM> defining entry port <NUM>. Inner liner <NUM> and outer jacket <NUM> do not define circular cross-sections in the portion of catheter <NUM> shown in <FIG> because they are configured (e.g., by skiving) to define entry port <NUM>. In addition, anchor body <NUM> is not present in the portion of catheter <NUM> shown in <FIG>.

<FIG> and <FIG> are conceptual cross-sectional views of examples of catheter <NUM> of <FIG> and <FIG> taken along line <NUM>-<NUM> in <FIG>, and <FIG> and <FIG> are conceptual cross-sectional views of examples of catheter <NUM> of <FIG> and <FIG> taken along line <NUM>-<NUM> in <FIG>. <FIG> and <FIG> are conceptual cross-sectional views of catheter <NUM> during assembly of elongate body <NUM>, after anchor member <NUM> has been inserted and advanced between inner liner <NUM> and outer jacket <NUM>. <FIG> and <FIG> are a conceptual cross-sectional view of catheter <NUM> after assembly of catheter <NUM>, after anchor member <NUM> has been inserted and advanced between inner liner <NUM> and outer jacket <NUM>, as shown in <FIG> and <FIG>, respectively, and after heat has been applied to inner liner <NUM> and outer jacket <NUM> to reflow material of inner liner <NUM> and outer jacket <NUM> around anchor member <NUM>.

As shown in <FIG>, anchor member <NUM> may be positioned between outer jacket <NUM> and inner liner <NUM> such that anchor member <NUM> is positioned within outer jacket <NUM> and at least partially around an outer perimeter of inner liner <NUM>. In some examples, anchor member <NUM> may extend about <NUM> degrees to about <NUM> degrees around the outer perimeter of inner liner <NUM>. For example, a widest portion of anchor member <NUM>, as shown in <FIG> and <FIG> may extend about <NUM> degrees to about <NUM> degrees around the widest portion of inner liner <NUM>. For example, in some examples, anchor member <NUM> may extend about <NUM> degrees around the outer perimeter of inner liner <NUM>.

Anchor member <NUM> defines an inner surface <NUM> and an outer surface <NUM>, and, in some examples, one or more of inner surface <NUM> and outer surface <NUM> may define a substantially semicircular surface but may, in some examples, include surface irregularities (e.g., waves, bumps, or other texturing). Anchor member <NUM> may have a thickness tAM measured in a direction perpendicular to longitudinal axis X of catheter <NUM>. In some examples, thickness tAM may be about <NUM> micrometers thick to about <NUM> micrometers thick, such as about <NUM> micrometers thick or any other size suitable to fit between inner liner <NUM> and outer jacket <NUM> while also having suitable strength to secure push assembly <NUM> to elongate body <NUM>. As shown in <FIG>, welding material <NUM> may join elongate member <NUM> to anchor member <NUM>, as describe in further detail below with respect to <FIG>.

As shown in <FIG> and <FIG>, in some examples, heat may be applied to inner liner <NUM> and/or outer jacket <NUM> to reflow material from inner liner <NUM> and/or outer jacket <NUM> around anchor member <NUM> to bond anchor member <NUM> between inner liner <NUM> and outer jacket <NUM>. Although <FIG> shows reflow of material from both inner liner <NUM> and outer jacket <NUM>, in some examples, heat may be applied to only one of inner liner <NUM> and outer jacket <NUM> and/or material from only one of inner liner <NUM> and outer jacket <NUM> may be reflowed around anchor member <NUM>. Alternatively, or in addition to reflow, other methods may be used to bond anchor member <NUM> between inner liner <NUM> and outer jacket <NUM>. For example, adhesives may be used. Bonding inner liner <NUM> and/or outer jacket <NUM> to anchor member <NUM> may improve the bond between elongate body <NUM> and push assembly <NUM> over methods wherein elongate member <NUM> is bonded directly to inner liner <NUM> and/or outer jacket <NUM>, and may thus improve tensile strength, by providing greater surface area for bonding.

<FIG> is a conceptual perspective view of anchor member <NUM> of <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. <FIG> are conceptual perspective views of push assembly <NUM> of <FIG>, <FIG>, and <FIG>. As shown in <FIG>, <FIG>, anchor member <NUM> may define a partial-ring shape. As shown in <FIG>, anchor member <NUM> may be secured to elongate member <NUM> to form push assembly <NUM>. For example, anchor member <NUM> may be welded to distal end <NUM> of elongate member <NUM> as described in further detail below with reference to <FIG>. As another example, anchor member <NUM> may be adhered or otherwise mechanically connected to distal end <NUM> of elongate member <NUM>.

In some examples, anchor member <NUM> may be formed of a radiopaque material such that anchor member <NUM> may serve as a radiopaque marker to indicate a location of entry port <NUM> to lumen <NUM> of elongate body <NUM>. In other cases, a band may be added to anchor member <NUM> to serve as a marker. As discussed above, because anchor member <NUM> is not circular in cross-section, a radiopaque anchor member <NUM> may help indicate a rotational orientation of catheter <NUM> (e.g., a rotational orientation of entry port <NUM>) within vasculature of a patient. In contrast, an anchor member having a circular cross-section would not indicate the rotational position of entry port <NUM> of catheter <NUM>, as the rotational position of the anchor member within a medical image would not appear to change based on the rotational orientation of entry port <NUM> about longitudinal axis X.

<FIG> is a conceptual perspective view of an example push assembly <NUM>, such as push assembly <NUM> of <FIG>, <FIG>, <FIG>, further including a radiopaque band <NUM>.

Push assembly <NUM> may include anchor member <NUM> and elongate member <NUM>. In some examples, anchor member <NUM> may include one or more radiopaque bands <NUM> to facilitate visualization of anchor member <NUM>.

Band <NUM> may be formed from a radiopaque material and can include, for example, a radiopaque marker band (e.g., one or more partial rings) attached to anchor member <NUM>, e.g., by an adhesive or weld. In some examples, band <NUM> may include any suitable radiopaque material. In addition to, or instead of a radiopaque marker band, band <NUM> may include one or more grooves protruding from an outer surface <NUM> of anchor member <NUM> or defined by and recessed within outer surface <NUM> of anchor member <NUM>. Although band <NUM> is shown along an outer diameter of anchor member <NUM>, band <NUM> may include grooves including, for example, a series of tangential arcs along an inner diameter of anchor member <NUM> and may be formed from a radiopaque material, or may be filled with a radiopaque material in the case of recessed grooves, which may be visible within the patient with the aid of suitable medical imaging equipment. Band <NUM> may help a clinician determine an orientation and/or location of anchor member <NUM> and/or any suitable component of the device described herein.

<FIG> are conceptual cross-sectional views of example anchor members, such as anchor member <NUM> of <FIG> and <FIG>, with an inner and/or outer surface defining a non-semicircular surface. For example, as shown in <FIG>, anchor member <NUM> may define inner surface <NUM> and outer surface <NUM>, and one or more of inner surface <NUM> and outer surface <NUM> may define a non-semicircular surface. For example, outer surface <NUM> may define a plurality of notches 178a-178n. As another example, as shown in <FIG>, anchor member <NUM> may define inner surface <NUM> and outer surface <NUM> and one or more of inner surface <NUM> and outer surface <NUM> may define a plurality of waves 188a-188n. In some examples, as in <FIG>, both inner surface <NUM> and outer surface <NUM> may define a non-semicircular surface. In other examples, as in <FIG>, only one of inner surface <NUM> and outer surface <NUM> may define a substantially non-semicircular surface.

Although <FIG> show particular example anchor members <NUM> and <NUM> with non-semicircular and substantially semicircular surfaces, any suitable surfaces may be used according to particular needs. For example, an anchor member may define inner and outer surfaces both defining a plurality of waves. As another example, only one of an inner surface and an outer surface of an example anchor member may define a plurality of notches. In some examples, an anchor member may include one of an inner surface and an outer surface defining a plurality of notches and another of the inner surface and outer surface defining a plurality of waves. An anchor member may have any suitable combination of inner and outer surfaces according to particular needs.

In some examples, an anchor member with inner and/or outer surfaces defining non-semicircular surfaces may provide particular advantages. For example, such non-semicircular advantages may increase surface area of the surface(s) and thus improve bond between the anchor member and the inner liner, and/or the outer jacket. For example, reflow of inner liner and/or outer jacket material may bond with a greater surface area of the anchor member and may thus improve the bond between the inner liner and/or outer jacket and the anchor member.

Anchor member <NUM> may be mechanically connected to elongate member <NUM> using any suitable technique, such as, but not limited to, welding, an adhesive, or mechanical fixation mechanism, such as a strap, or the like. <FIG> is a conceptual side view of an example of anchor member <NUM> of push assembly <NUM> of <FIG>, <FIG> and a distal portion of elongate member <NUM> of the push assembly <NUM> of <FIG>, <FIG>, before anchor member <NUM> and elongate member <NUM> are mechanically connected together to form push assembly <NUM>. <FIG> is a conceptual side view of push assembly <NUM> of <FIG> after anchor member <NUM> and elongate member <NUM> are mechanically connected together to form push assembly <NUM>.

As shown in <FIG>, anchor member <NUM> may extend from a proximal end <NUM> to a distal end <NUM>. Length LAM of anchor member <NUM> may be measured along axis X (where orthogonal x-y axes are shown in <FIG> for ease of description only) from proximal end <NUM> to distal end <NUM> of anchor member <NUM>. In some examples, length LAM of anchor member <NUM> is about <NUM> to about <NUM>, such as about <NUM>. Anchor <NUM> may have other lengths in other examples. Anchor member <NUM> may define a slot <NUM> extending from proximal end <NUM> towards distal end <NUM>. In some examples, distal end <NUM> of elongate member <NUM> may be positioned at least partially within slot <NUM>. In some examples, slot <NUM> has a length LS from about <NUM> percent to about <NUM> percent of a length LAM of anchor member <NUM>. In some examples, length LS of slot <NUM> may be about <NUM> percent to about <NUM> percent of length LAM of anchor member <NUM>. In some examples, anchor member <NUM> may be welded to elongate member <NUM>. For example, as shown in <FIG>, welding material <NUM> may be placed within slot <NUM> and between anchor member <NUM> and elongate member <NUM>. In some examples, slot <NUM> may extend through the entire thickness tAM of anchor member <NUM>. In other examples, slot <NUM> may extend only partially through thickness tAM of anchor member <NUM>. Slot <NUM> may extend a thickness sufficient to receive distal end <NUM> of elongate member <NUM> and welding material <NUM>.

Anchor member <NUM> defining a slot <NUM> within which distal end <NUM> of elongate member <NUM> and welding material <NUM> may be placed in order to bond distal end <NUM> of elongate member <NUM> to anchor member <NUM> may provide one or more advantages. For example, slot <NUM> may increase the surface area of the portions of elongate member <NUM> and anchor member <NUM> that are mechanically connected to each other, which may increase the strength of the mechanical connection between elongate member <NUM> and anchor member <NUM>. As another example, slot <NUM> may provide for a lower radial profile of push assembly <NUM> compared to examples in which an anchor member does not include a slot or in which a slot is not wide enough for both distal end <NUM> of elongate member <NUM> and welding material <NUM> because distal end <NUM> and/or welding material <NUM> need not increase a radial profile of elongate body <NUM> and/or push assembly <NUM> by extending radially, inwardly or outwardly, from anchor member <NUM>. This may also provide improved assembly of catheter <NUM> by providing a less bulky push assembly <NUM> that may be more easily inserted and advanced between inner liner <NUM> and outer jacket <NUM>.

<FIG> is a conceptual perspective view of a portion of an example elongate member <NUM> of <FIG>, <FIG>, <FIG>, and <FIG>. In some examples, a sleeve <NUM> may surround at least a portion of elongate member <NUM>. In some examples, a sleeve <NUM> may surround at least a portion of elongate member <NUM> external to lumen <NUM> defined by elongate body. Sleeve <NUM> may include one or more layers of material configured to surround at least a portion of elongate member <NUM> and to distinguish elongate member <NUM> from other medical devices and/or to enable easier grip of elongate member <NUM>.

In some examples, sleeve <NUM> may be textured such that it defines at least one textured surface, which may help a clinician grip sleeve <NUM> and/or sleeve <NUM> grip elongate member <NUM>. For example, in some examples, sleeve <NUM> may be etched such that it defines at least one etched surface. As another example, sleeve <NUM> may define ridges, grooves, or the like on the surface facing outward (the surface that a clinician would grip when engaging sleeve <NUM>), and/or on the surface facing elongate member <NUM>.

In addition to, or instead of, aiding a clinician's handling of elongate member <NUM>, in some examples, sleeve <NUM> may provide one or more visible indicia that help differentiate elongate member <NUM> from other medical devices. For example, sleeve <NUM> may be a different color than at least one of elongate member <NUM>, inner liner <NUM>, and outer jacket <NUM>. In addition, or instead, sleeve <NUM> may include one or more visible and/or tactile bands <NUM>. In some examples, bands <NUM> may include a partial cut around a perimeter of sleeve <NUM>. In some examples, the partial cut may extend only partially through a radial thickness tS of sleeve <NUM>. In some examples, the partial cut may extend <NUM> degrees around a perimeter of sleeve <NUM>. Bands <NUM> may include a double-stripe mark. Bands <NUM> may include a marker with any suitable visual characteristics, such as, but not limited to, a particular color(s), visible pattern(s), and/or texture(s).

Sleeve <NUM> may provide particular advantages. For example, sleeve <NUM> including a textured surface, having a distinct color, having bands <NUM> and/or or other visually distinct indicium or indicia may help to tactilely and/or visually distinguish elongate member <NUM> from other components including, for example, a guidewire or other catheters or devices used with catheter <NUM> such that a user may more easily distinguish it from other components. For example, without sleeve <NUM>, elongate member <NUM> may look and/or feel like a guidewire and may be difficult to identify as being a part of push assembly <NUM>.

<FIG> is a flowchart illustrating an example method including the various stages of assembly of example catheter <NUM> shown in <FIG> and <FIG>. In accordance with this method of assembly, anchor member <NUM> of push assembly <NUM> is inserted between inner liner <NUM> and outer jacket <NUM> of catheter <NUM> such that, after insertion, anchor member <NUM> extends only partially around an outer perimeter of inner liner <NUM> (<NUM>). In some examples, anchor member <NUM> is advanced between inner liner <NUM> and outer jacket <NUM> in a distal direction (<NUM>). In some examples, anchor member <NUM> may be advanced between inner liner <NUM> and outer jacket <NUM> in a distal direction until proximal end <NUM> of anchor member <NUM> is aligned with proximal end <NUM> of entry port <NUM>. In other examples, anchor member <NUM> may be advanced between inner liner <NUM> and outer jacket <NUM> in a distal direction until distal end <NUM> of anchor member <NUM> is aligned with distal end <NUM> of entry port <NUM>. Anchor member <NUM> may be advanced to any suitable position between inner liner <NUM> and outer jacket <NUM> according to particular needs.

After insertion and advancement of anchor member <NUM>, distal to proximal end <NUM> of elongate body <NUM>, a portion of push assembly <NUM>, including anchor member <NUM>, is positioned between adjacent portions inner liner <NUM> and outer jacket <NUM> and, proximal end <NUM> of elongate body <NUM>, a portion of push assembly <NUM> is positioned outside of outer jacket <NUM> and inner liner <NUM>.

In some examples, heat may be applied to inner liner <NUM> and/or outer jacket <NUM> to reflow material around anchor member <NUM> (<NUM>).

In some examples, a method, described for explanatory purposes only, of assembly may further include abrasive processing of elongate member <NUM> to form a taper, such as the D-shaped taper illustrated in <FIG>. The abrasive processing may include, for example, grinding, sanding, or grit blasting at least a portion of elongate member <NUM> to remove material.

In some examples, a method of assembly, described for explanatory purposes only, may further include coupling anchor member <NUM> to elongate member <NUM>. For example, anchor member <NUM> may be coupled to elongate member <NUM> before insertion of anchor member <NUM> between inner liner <NUM> and outer jacket <NUM> of catheter <NUM>. In some examples, coupling anchor member <NUM> to elongate member <NUM> may include positioning distal end <NUM> of elongate member <NUM> at least partially within slot <NUM> of anchor member <NUM>. In some examples, coupling anchor member <NUM> to elongate member <NUM> may include welding anchor member <NUM> to elongate member <NUM>. In some examples, welding anchor member <NUM> to elongate member <NUM> may include placing welding material <NUM> within slot <NUM> and between anchor member <NUM> and elongate member <NUM>.

In some examples, the method, described for explanatory purposes only, may further include positioning reinforcement member <NUM> between at least a portion of inner liner <NUM> and at least a portion of outer jacket <NUM>. In some examples, the method may include positioning distal end <NUM> of anchor member <NUM> proximal to reinforcement member <NUM>. In some examples, the method may include positioning distal end <NUM> of anchor member <NUM> such that it abuts proximal end <NUM> of reinforcement member <NUM>. In some examples, the method may include positioning sleeve <NUM> around at least a portion of elongate member <NUM>.

In some examples, a catheter may include a distal tip portion configured to reduce impact force between a distal tip of the catheter and tissue of a patient during as the catheter is advance through vasculature of a patient. The distal tip portion may include a construction that reduces an effective durometer of the distal tip portion compared to a more proximal portion of the catheter. For example, the distal tip portion may include a tip outer jacket that includes a material or mixture of materials that has a lower durometer than an outer jacket of a more proximal portion of the catheter. As another example, an inner liner may end proximal of the distal tip, reducing an effective durometer of the distal tip portion.

<FIG> are conceptual side cross-sectional views of a distal tip portion of example catheters that include a distal tip portion configured to reduce impact force between a distal tip of the catheter and tissue of a patient during as the catheter is advance through vasculature of a patient. <FIG> illustrates part of a catheter <NUM> that includes an elongate body <NUM> including a proximal portion <NUM> and a distal tip portion <NUM>. Catheter <NUM> may be an example of any of the other catheters described herein, such as catheter <NUM>. As such, a portion of catheter <NUM> not shown in <FIG> may include a push assembly (like push assembly <NUM>) that includes an elongate push member joined to elongate body <NUM> at or near a proximal end of elongate body <NUM>.

Elongate body <NUM> includes proximal portion <NUM> and distal tip portion <NUM>. Proximal portion <NUM> is proximal of distal tip portion <NUM> and may extend to a proximal end of elongate body <NUM>. Proximal portion <NUM> includes a proximal portion of an inner liner <NUM>, a proximal portion of an outer jacket <NUM>, and a proximal portion of a reinforcement member <NUM>.

Inner liner <NUM> defines a lumen <NUM> that extends from adjacent to or at a proximal end of elongate body <NUM> to adjacent to or at distal end <NUM> of elongate body <NUM>. Lumen <NUM> enables introduction of a medical device (e.g., a catheter, guidewire, filter, stent delivery system, and the like), therapeutic agent, or other element into vasculature or other tissue sites of a patient.

Inner liner <NUM> may be formed from any suitable material, such as, but not limited to a fluoropolymer, such as polytetrafluorethylene (PTFE), a polyolefin, such as high density polyethylene (HDPE), or the like. In some examples, inner liner <NUM> may include a lubricious or hydrophilic coating o inner surface <NUM>. In some examples, inner liner <NUM> may include multiple layers, such as a radially inner layer including a fluoropolymer or polyolefin and a radially outer layer that increases adhesion to outer jacket <NUM>. The radially outer layer may include any suitable adhesion-increasing polymer, such as, for example, a polyamide, a polyimide, or a poly(ether-block-amide). In some implementations, the radially inner layer may constitute approximately <NUM>% of the thickness of inner liner <NUM> and the radially outer layer may constitute approximately <NUM>% of the thickness of inner liner <NUM>.

Outer jacket <NUM> may include any suitable material, such as any suitable polymer. In some examples, outer jacket <NUM> may include a polyamide, a polyimide, or a poly(ether-block-amide). The polymer may be selected to have tensile properties that facilitate force transfer axially along elongate body <NUM> to enable pushing of catheter <NUM> and advancing catheter <NUM> through vasculature of a patient, through lumen <NUM> of outer catheter <NUM> (<FIG>), or the like. For example, outer jacket <NUM> may include a mixture of a first poly(ether-block-amide) available under the trade designation PEBAX® <NUM> (having a Shore D hardness of about <NUM>) from Arkema Group, Colombes, France and a second poly(ether-block-amide) available under the trade designation PEBAX® <NUM> from Arkema. PEBAX® <NUM> has a durometer or Shore D hardness of about <NUM> and PEBAX® <NUM> has a durometer or Shore D hardness of about <NUM>. Thus, a mixture or blend of PEBAX® <NUM> and PEBAX® <NUM> may have a durometer or Shore D hardness between about <NUM> and <NUM>, depending on the relative amounts of the first and second poly(ether-block-amide).

In some examples, elongate body <NUM> also includes a reinforcement member <NUM> radially outward from inner liner <NUM> and radially inward from or within outer jacket <NUM>. Reinforcement member <NUM> may be any suitable structure configured to provide structural support to elongate body <NUM> and, in some examples, increase the structural integrity of elongate body <NUM>, e.g., to facilitate force transfer axially along elongate body <NUM> to enable pushing of catheter <NUM> and advancing catheter <NUM> through vasculature of a patient, through lumen <NUM> of outer catheter <NUM> (<FIG>), or the like. For example, reinforcement member <NUM> may comprise a metal coil, a metal braid, or a combination thereof. Reinforcement member <NUM> may be between inner liner <NUM> and outer jacket <NUM> or may be embedded within outer jacket <NUM>, as shown in <FIG>.

In the example shown in <FIG>, each of inner liner <NUM>, outer jacket <NUM>, and reinforcement member <NUM> extend into distal tip portion <NUM> of elongate body <NUM>. As shown in <FIG>, in some examples, outer jacket <NUM> ends at a distal outer jacket end <NUM> that is proximal of the distal tip <NUM> of elongate body <NUM>. Distal of distal outer jacket end <NUM> and laterally adjacent to outer jacket <NUM>, elongate body <NUM> includes a tip outer jacket <NUM>. In some examples, a proximal tip outer jacket end <NUM> of tip outer jacket <NUM> laterally abuts (contacts) distal outer jacket end <NUM>. In other examples, proximal tip outer jacket end <NUM> is bonded to distal outer jacket end <NUM>, e.g., using diffusion bonding, polymer welding, or the like.

Tip outer jacket <NUM> may include any suitable material, such as any suitable polymer. In some examples, tip outer jacket <NUM> may include a polyamide, a polyimide, or a poly(ether-block-amide). The polymer may be selected to have a durometer or hardness less than the durometer or hardness of outer jacket <NUM>. For example, tip outer jacket <NUM> may include a poly(ether-block-amide) available under the trade designation PEBAX® <NUM> from Arkema Group. PEBAX ® <NUM> has a Shore D hardness of about <NUM>. Due to the lower durometer or hardness of tip outer jacket <NUM> compared to outer jacket <NUM>, distal tip portion <NUM> may reduce force transmission from catheter <NUM> to tissue upon contact between distal tip <NUM> and tissue compared to a catheter in which outer jacket <NUM> extends to distal tip <NUM>. For example, distal tip portion <NUM> may more easily compress or deflect due to its lower hardness, which reduces force transmission to tissue. This may result in distal tip portion <NUM> being more atraumatic to tissue.

In some examples, elongate body <NUM> may include an optional hydrophilic coating <NUM> on outer surfaces of outer jacket <NUM> and tip outer jacket <NUM>. Hydrophilic coating <NUM> may include, for example, a hydrogel or other hydrophilic material.

As shown in <FIG>, a marker band <NUM> is embedded in tip outer jacket <NUM>, and tip outer jacket <NUM> extends both proximal and distal to marker band <NUM>. Marker band <NUM> may include a cylinder or partial cylinder of a radiopaque material, such as a radiopaque metal or alloy. Example radiopaque metals or alloys include platinum iridium (PtIr), cobalt chromium (CoCr), and the like. Marker band <NUM> facilitates imaging of the distal end of catheter <NUM>, but also may increase the hardness of catheter <NUM> at the axial position of marker band <NUM>. As such, by having tip outer jacket <NUM> extend both proximal and distal to marker band <NUM>, the reduced durometer or hardness of tip outer jacket <NUM> may facilitate bending or deflection of catheter <NUM> both proximal and distal to marker band <NUM>. This also contributes to distal tip portion <NUM> being more atraumatic to tissue.

In some examples, marker band <NUM> defines an axial length (between marker band proximal end <NUM> and marker band distal end <NUM>) of between about <NUM> and about <NUM>, such as between about <NUM> and about <NUM>. Tip outer jacket <NUM> may extend a length L1 beyond (distal to) marker band distal end <NUM>. Length L1 may be between about <NUM> and about <NUM>, such as between about <NUM> and about <NUM>, or about <NUM> ± <NUM>.

Tip outer jacket <NUM> may extend a length L2 proximal to marker band proximal end <NUM>. Length L2 may be between about <NUM> and about <NUM>, such as between about <NUM> and about <NUM>, or about <NUM> ± <NUM>.

In the example shown in <FIG>, inner liner <NUM> extends to distal tip <NUM> of elongate body <NUM>. In other examples, inner liner <NUM> may terminate proximal to distal tip <NUM>. By terminating inner liner <NUM> proximal to distal tip <NUM>, the durometer or hardness of the distal-most portion of distal tip portion <NUM> may be further reduced, further reducing force transmission from catheter <NUM> to tissue in the event of contact. For example, as shown in <FIG>, a catheter <NUM> may include an inner liner <NUM> that ends distal to marker band distal end <NUM> and proximal to distal tip <NUM>. As another example, as shown in <FIG>, a catheter <NUM> may include an inner liner <NUM> that ends at about marker band distal end <NUM> (e.g., is aligned with marker band distal end <NUM> to the extent permitted by manufacturing tolerances or is within about <NUM> of marker band distal end <NUM>) and proximal to distal tip <NUM>. Inner liner <NUM> may extend distal of a distal end of reinforcement member <NUM> to reduce a likelihood of reinforcement member <NUM> separating from other components of catheter <NUM>.

In the example shown in <FIG>, reinforcement member <NUM> extends under and overlaps marker band <NUM> such that marker band <NUM> helps maintain the position of the distal end of reinforcement member <NUM> within catheter <NUM>. In other examples, a catheter <NUM> may include a reinforcement member <NUM> that ends proximal of marker band proximal end <NUM>, as shown in <FIG>, or a catheter <NUM> may include a reinforcement member <NUM> that ends substantially aligned with marker band proximal end <NUM>, as shown in <FIG>. Further, reinforcement member <NUM> may include substantially constant spacing (or pitch) between adjacent turns of the reinforcement elements (e.g., coil windings in a coil or filament windings in a braid), as shown in <FIG>. In other examples, reinforcement member <NUM> may include a changing spacing (or pitch) between adjacent turns of the reinforcement elements. For example, as shown in <FIG>, a catheter <NUM> may include a reinforcement member <NUM> that includes a first spacing or pitch between adjacent turns of the reinforcement elements in proximal portion <NUM> and a second spacing or pitch between adjacent turns of the reinforcement elements in distal tip portion <NUM>. The second spacing or pitch may be greater than the first spacing or pitch, as shown in <FIG>, or may be less than the first spacing or pitch. Changing the spacing or pitch of reinforcement member <NUM> from proximal portion <NUM> to distal tip portion <NUM> may provide further control to the hardness of distal tip portion <NUM> relative to proximal portion <NUM>.

In some implementations, a catheter may not include a separate tip outer layer, and a configuration of other structural components of the catheter may be designed to reduce impact force between a distal tip of the catheter and tissue of a patient during as the catheter is advance through vasculature of a patient. For example, <FIG> is a conceptual cross-sectional diagram of an example catheter <NUM> in which outer jacket <NUM> extends to distal tip <NUM> of elongate body <NUM>. In the example of <FIG>, inner liner <NUM> ends distal of marker band distal end <NUM> and proximal to distal tip <NUM> of elongate body <NUM>. In this way, a distal-most part of distal tip portion <NUM> had a lower hardness or durometer due to the omission of inner liner <NUM>. Inner liner <NUM> may end at any position between marker band distal end <NUM> and proximal to distal tip <NUM> of elongate body <NUM>, e.g., the position shown in <FIG>. The structural features illustrated in <FIG> for catheter <NUM> may be combined with other features illustrated in <FIG>, as will be apparent to a person having ordinary skill in the art.

A vertically-oriented tensile test machine available from ZwickRoell USA, Kennesaw, Georgia was modified by removing the bottom grip. A compression water bath was secured on the base of the tensile test machine with the top grip centered directly over a <NUM>-degree angled test surface, as shown in <FIG>. The distance between the bottom of the top grip and the top of the compression water bath was about <NUM>.

The tip compression bath was filled with water and water circulated between the tip compression bath and a heater to heat the water to a temperature of about <NUM> ± <NUM>.

For each catheter tested, about <NUM> of the distal-most portion was separated from the catheter. A support pin was inserted in the lumen of the distal-most portion and extended about <NUM> past the proximal end of the distal-most portion. The distal-most portion was placed in the groove of the top grip and the distal end of the distal-most portion extended about <NUM> from the bottom of the top grip.

To test tip compression force, the tensile test machine was programmed to advance the catheter vertically a total of <NUM> after detecting contact of the distal tip with the test surface. The force output was recorded. <FIG> is a plot of tip compression force measured in grams-force for an example catheter constructed in accordance with this disclosure and three comparative examples. As shown in <FIG>, the tip compression force is significantly lower for the example catheter constructed in accordance with this disclosure.

Claim 1:
A catheter (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
an elongate body (<NUM>, <NUM>) comprising:
a proximal portion including a proximal end (<NUM>); and
a distal tip portion (<NUM>), wherein the distal tip portion (<NUM>) comprises:
an inner liner (<NUM>, <NUM>);
a marker band (<NUM>) circumferentially surrounding the inner liner (<NUM>, <NUM>) and extending from a marker band proximal end (<NUM>) to a marker band distal end (<NUM>);
an outer jacket (<NUM>, <NUM>) circumferentially surrounding a first portion of the inner liner (<NUM>, <NUM>) and ending proximal of the marker band proximal end (<NUM>); and
a tip outer jacket (<NUM>) circumferentially surrounding a second portion of the inner liner (<NUM>, <NUM>) and the marker band (<NUM>), wherein the tip outer jacket (<NUM>) extends distally past the marker band distal end (<NUM>) to a distal tip (<NUM>) of the elongate body (<NUM>, <NUM>), and wherein a proximal end of the tip outer jacket (<NUM>) is laterally adjacent to a distal end of the outer jacket (<NUM>, <NUM>); and
further comprising an elongate push member (<NUM>) mechanically coupled to a proximal end (<NUM>) of the elongate body (<NUM>, <NUM>), and wherein the elongate body (<NUM>, <NUM>) defines at least one lumen (<NUM>) extending from adjacent to or at the proximal end (<NUM>) to adjacent to or at the distal tip (<NUM>).