Patent Description:
The use of intravascular catheters, push wires, guidewires, coils and other types of elongated delivery members for accessing and treating various types of diseases, such as vascular defects, is well-known. For example, a suitable intravascular catheter, guidewire or other delivery member may be inserted into the vascular system of a patient. Commonly used vascular application to access a target site in a patient involves inserting a guidewire through an incision in the femoral artery near the groin, and advancing the guidewire until it reaches the target site. Then, a catheter is advanced over the guidewire until an open distal end of the catheter is disposed at the target site. Simultaneously or after placement of the distal end of the catheter at the target site, an intravascular implant is advanced through the catheter via a delivery wire.

In certain applications, such as neurovascular treatment, the guidewires, delivery wires, and catheters are required to navigate tortuous and intricate vasculature. By using an appropriately sized device having the requisite performance characteristics, such as "pushability" "steerability", "torquability" and most important, distal tip flexibility, virtually any target site in the vascular system may be accessed, including that within the tortuous cerebral and peripheral vasculature. Further, the forces applied at the proximal end of these wires should be transferred to the distal ends for suitable pushability (axial rigidity) and torqueability (rotation). Achieving a balance between these features is highly desirable, but difficult. For example, the guidewires and/or delivery wires may comprise variable stiffness sections (e.g., achieved by varying ratio of material, including selective reinforcement, such as braids, coils, or the like, in different sections of the wires) suitable to provide sufficient flexibility, kink resistance, pushability, and torqueability to allow navigation through vasculature.

In some cases, catheters, guidewires or other delivery members may include slots along their elongated body or selected portions thereof. Incorporating slots into these elongated medical devices can modify or customize the device flexibility/stiffness. For example, distal portions of catheters, guidewires or other delivery members may have a slot pattern (e.g., more slots per area, longer slots, and/or wider slots) that increases the flexibility thereof. When used as components of a delivery system, the slotted elongated tubular devices are preferably substantially sealed (e.g., using sheath, jacket, coating or their like), in order to prevent fluid exchange (into or out of) the inner lumen of the tube, and also to enhance lubricity. Exemplary slotted and coated medical devices are disclosed in <CIT>,<CIT>, <CIT>, and <CIT>.

<CIT> discloses a catheter having a hypotube with a cut formed therein. <CIT> discloses an inner cannula for a tracheostomy tube assembly, which is formed from a tubular member having two parallel rows of slots formed along its length and covered by a sheath of thin flexible material on the inside of the tubular member. <CIT> discloses a catheter device comprising a micro-fabricated elongated outer member having an outer surface and an interior surface forming a lumen extending from a proximal end to a distal end, and a plurality of fenestrations made through the outer surface and the interior surface into at least a portion of the lumen. The catheter device also has an outer elastomer laminate layer in contact with at least a portion of the outer surface and filling the plurality of fenestrations. <CIT> discloses a catheter for delivering a fluid to an anatomical region, the catheter having a plurality of openings extending through a side wall of a catheter body.

Having a sheath, jacket, or coating over slotted elongated tubular devices increases the volume and also the outer diameter (OD) of the device, which may negatively impact the overall performance of the device when advanced through narrow bends and tortuous vasculature.

The invention is based on the task of providing an improved medical device of the type described above. The task is solved by a device according to claim <NUM>. Advantageous embodiments are given in the dependent claims.

In accordance with the invention is a catheter provided in claim <NUM>.

As an example, that may, if applicable, provide details to further specify embodiments claimed or described in this application a medical device is provided that includes: an elongated member having a proximal end, a distal end, and a body extending between the proximal end and the distal end; wherein the elongated member comprises a tubular section having a plurality of openings extending into a wall of the tubular section, the plurality of openings comprising a first opening; and wherein the elongated member further comprises fillers respectively located in the openings, the fillers comprising a first filler, wherein the first filler comprises a spongy material located in the first opening.

Optionally, the spongy material comprises a foam material.

Optionally, the spongy material is compressible, stretchable, or both.

Optionally, the first filler is in abutment against two opposite surfaces that define the first opening.

Optionally, the first filler is fixedly secured to the two opposite surfaces that define the first opening.

Optionally, the plurality of openings extends through the wall of the tubular section.

Optionally, the tubular section comprises a lumen defined by an inner surface of the wall of the tubular section, and wherein the first filler does not extend past the inner surface into the lumen.

Optionally, the wall of the tubular section comprises an exterior surface, and wherein the first filler does not extend past the exterior surface.

Optionally, the first filler completely fills an entirety of the first opening.

Optionally, the first filler fills only a portion of the first opening.

Optionally, the fillers do not extend beyond boundaries of the openings.

Optionally, the spongy material comprises laser-drilled or laser-cut openings.

Optionally, the spongy material comprises a closed cell material.

Optionally, the medical device is a guidewire.

Optionally, the medical device is a delivery wire.

Optionally, the medical device is an implant.

Optionally, the medical device is a catheter.

Optionally, one of the openings has a width that is less than <NUM>.

As another example, that may, if applicable, provide details to further specify embodiments claimed or described in this application a medical device is provided that includes: an elongated member having a proximal end, a distal end, and a body extending between the proximal end and the distal end; wherein the elongated member comprises a tubular section having a plurality of openings extending into a wall of the tubular section, the plurality of openings comprising a first opening; and wherein the elongated member further comprises fillers respectively located in the openings, the filers comprising a first filler that does not extend beyond any boundary of the first opening.

Optionally, the first filler comprises a spongy material located in the first opening.

Optionally, the first filler is make from a material that is compressible, stretchable, or both.

Other and further aspects and features of embodiments will become apparent from the ensuing detailed description in view of the accompanying figures.

It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by the same reference numerals throughout the figures.

In some cases, the term "about" may refer to a range of values that are within +/- <NUM>% of a value. For example, a value of <NUM> or a value of about <NUM> may refer to any value that is within the range of <NUM> +/- <NUM>% ( = <NUM> +/- <NUM> = <NUM> to <NUM>).

<FIG> depicts a medical device <NUM> according to the invention. The medical device <NUM> is configured for insertion into a blood vessel <NUM>. The medical device <NUM> may be a catheter, a guidewire, a delivery wire (e.g., push wire), an implant (e.g., a coil), a combination of the foregoing, or any of other types of elongated member for medical use, such as for treatment and/or for diagnostic of a medical condition.

The medical device <NUM> includes an elongated member <NUM> having a proximal end <NUM>, a distal end <NUM>, and a body <NUM> extending between the proximal end <NUM> and the distal end <NUM>. The elongated member <NUM> comprises a tubular section <NUM> at the distal end <NUM> of the elongated member <NUM>. The tubular section <NUM> is configured to increase a flexibility of the distal end <NUM> of the elongated member <NUM>. The tubular section <NUM> may be any elongated device or component having a lumen that can be formed from any material, such as, any suitable biocompatible metal, polymer, or a combination thereof. In some embodiments, the tubular section <NUM> may be a slotted hypotube. The tubular section <NUM> may have a circular cross-section in some embodiments. In other embodiments, the tubular section <NUM> of the elongated member <NUM> may have any cross-sectional shapes, such as an elliptical shape, or any custom-design shape. Also, in some embodiments, the tubular section <NUM> may have different cross-sectional shapes and/or cross-sectional dimensions along a longitudinal axis of the elongated member <NUM>.

<FIG> depict a part of the tubular section <NUM>. <FIG> and <FIG> are side and perspective views, respectively. <FIG> is an axial cross-sectional view along the line labeled A-A in <FIG>. As shown in <FIG> and <FIG>, the tubular section <NUM> includes a plurality of openings <NUM> extending into a wall of the tubular section <NUM>. In the illustrated example, the openings <NUM> are elongated slots <NUM> that extend circumferentially around a longitudinal axis of tubular section <NUM>. The tubular section <NUM> has sets <NUM> of slots <NUM> at respective longitudinal positions along the longitudinal axis of the tubular section <NUM> of the elongated member <NUM>. As a result of segmentation by the slots <NUM>, the tubular section <NUM> has a stack of annular segments (e.g., rings) <NUM> connected by a plurality of beams <NUM>. The annular segments <NUM> are connected sequentially by corresponding plurality of groups (e.g., pairs) <NUM> of beams <NUM>.

As shown in <FIG>, the beams <NUM> in each group <NUM> are disposed in the same plane that is perpendicular to the longitudinal axis of the tubular section <NUM>. In the illustrated embodiments, each group <NUM> has two beams <NUM> disposed on opposite sides of the tubular section <NUM>. In other embodiments, each group <NUM> may have more than two beams <NUM>, or only a single beam <NUM>. The beams <NUM> in each group <NUM> may be spaced apart from each other circumferentially by an equal distance. As shown in the figure, each beam <NUM> in the pair <NUM> has flat walls <NUM> at opposite ends of the beam <NUM>. The walls <NUM> of the beams <NUM> in the pair <NUM> can be formed with two cuts in some embodiments.

In some embodiments, the openings (e.g., slots) <NUM> may be formed in the tubular section <NUM> by saw-cutting the tubular section <NUM> with circular blades, micro-machining, laser cutting, electric discharge machining, plasma arc cutting, grinding, milling, casting, molding, chemically etching, or other known suitable methods, and the like. In other embodiments, the tubular section with the openings <NUM> may be produced using "additive" manufacturing (e.g., 3D printing) rather than the various "subtractive" techniques described.

In some embodiments, the openings (e.g., slots) <NUM> extend through the wall of the tubular section <NUM>. In particular, the openings <NUM> penetrate radially through the entire thickness of the wall of the tubular section <NUM>. In such cases, the openings <NUM> formed in the tubular section <NUM> with a circular cross-section perpendicular to a longitudinal axis thereof will be arcuate when viewed from an axial direction (as shown in <FIG>). In other embodiments, the openings <NUM> do not penetrate the full thickness of the tubular section <NUM> - i.e., the openings <NUM> do not penetrate completely through the wall of the tubular section <NUM>. Instead, the openings <NUM> penetrate only partially into the wall of the tubular section <NUM>. The tubular section <NUM> may have a wall thickness that is anywhere between <NUM> and <NUM>, or anywhere between <NUM> and <NUM>, or anywhere between <NUM> and <NUM>. In other embodiments, the tubular section <NUM> may have a wall thickness that is higher than <NUM> or less than <NUM>.

The openings (e.g., slots) <NUM> are advantageous because they enhance the flexibility of the tubular section <NUM> of the elongated member <NUM>, while the beams <NUM> and annular segments <NUM> provide suitable torque transmission characteristics. The openings <NUM> are formed such that the annular segments <NUM> are interconnected by one or more beams <NUM>. Such an interconnected structure provides a relatively high degree of torsional stiffness, while retaining a desired level of lateral bending flexibility.

It should be noted that the tubular section <NUM> of the elongated member <NUM> is not limited to having the configuration and features described in the above examples, and that the tubular section <NUM> may have other configurations and features in other embodiments. For example, in other embodiments, the tubular section <NUM> of the elongated member <NUM> may have different arrangements and configurations of openings <NUM>, annular segments <NUM>, and beams <NUM>. In some embodiments, at least some or all of the beams <NUM> are disposed such that their respective longitudinal axes form a same angle or similar angles (e.g., <NUM> degrees +/- <NUM> degrees) with the longitudinal axis of the tubular section <NUM> (like that shown in <FIG>). In other embodiments, the beams <NUM> are disposed such that their respective longitudinal axes form different angles with the longitudinal axis of the tubular section <NUM>. It should be appreciated that the distribution and/or configuration of the openings <NUM>, annular segments <NUM>, and beams <NUM> may have any suitable variations and combinations thereof.

Additionally, the openings (e.g., slots) <NUM> may be arranged along the length of, or about the circumference of, the tubular section <NUM> in any manner to achieve desired properties. For example, adjacent openings <NUM>, or groups of openings <NUM>, may be arranged in a symmetrical pattern, such as being disposed essentially equally on opposite sides about the circumference of the tubular section <NUM>. Alternatively, adjacent openings <NUM> or groups of openings <NUM> (within a plane that is perpendicular to a longitudinal axis of the tubular section <NUM>) may be arranged in a non-symmetrical pattern. Furthermore, in some embodiments, the tubular section <NUM> may have only one opening (e.g., slot) <NUM> at each plane that is perpendicular to the longitudinal axis of the tubular section <NUM>. The opening <NUM> may extend at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, at least <NUM> degrees, etc., circumferentially around a longitudinal axis of the tubular section <NUM>. Additionally, adjacent openings <NUM>, or groups of openings <NUM>, may be equally spaced along the length of tubular section <NUM>. Alternatively, adjacent openings <NUM>, or groups of openings <NUM> may be arranged in an increasing or decreasing density pattern, and/or may be arranged in a non-symmetric or irregular pattern. Other characteristics, such as opening size, opening shape and/or opening angle with respect to the longitudinal axis of tubular section <NUM>, may also be varied along the length of tubular section <NUM> in order to vary the bending flexibility/stiffness, torsional stiffness, axial stiffness, any of other structural property of the tubular section <NUM>, or any combination of the foregoing. In further embodiments, if the openings <NUM> are in the form of slots, instead of having the slots extending circumferentially in a direction that is perpendicular to the longitudinal axis of the tubular section <NUM>, the slots may extend circumferentially in a direction that is slanted (e.g., forming a non-<NUM> degree angle) with respect to the longitudinal axis of the tubular section <NUM>. In some embodiments, the openings <NUM> are implemented at a distributed fashion between ends of the tubular section <NUM>. In other embodiments, it is contemplated that only part(s) of the tubular section <NUM> comprises the openings <NUM>, and that other portions of the tubular section <NUM> may not include any such openings <NUM>.

In one or more embodiments described herein, the elongated member <NUM> also includes fillers respectively located in the openings (e.g., slots) <NUM>. <FIG> depicts the tubular section <NUM> of the elongated member <NUM>, particularly showing the tubular section <NUM> having fillers <NUM> within respective openings <NUM>. In the illustrated embodiments, each filler <NUM> comprises a spongy material. Use of the spongy material to implement the filler <NUM> is advantageous because it facilitates mechanical bending of the elongated member <NUM>. Also, the spongy material may effectively lower a hardness of a bulk material, thereby enabling softness beyond the material's bulk characteristics, or enabling a more robust material to be used for manufacturing or processing purposes. The spongy material may be any porous material (e.g., microporous material) that is compressible, stretchable, or both. In one implementation, the spongy material may be a foam material. Also, in some cases, the spongy material may be achieved by laser drilling or cutting a polymer to create a sponge-like structure having openings. Holes in the sponge-like structure may not need to be sealed if the holes are sufficiently small such that blood viscosity may create an effective seal in cooperation with the holes. In some embodiments, the fillers <NUM> may be made from polymeric material(s), such as polyurethane, cellulose acetate, mixed esters cellulose, PTFE/polyester, acrylic copolymer, any of other biocompatible polymer, or any combination of the foregoing. The pore size of the fillers <NUM> may be configured to prevent viscous fluid, such as blood, outside the tubular section <NUM> to enter into, and to pass through, the fillers <NUM>. If the tubular section <NUM> is configured to deliver a substance, the pore size of the fillers <NUM> may also prevent the substance from within the tubular section <NUM> to enter into, and to pass through, the fillers <NUM>.

In some embodiments, the tubular section <NUM> of the elongated member <NUM> has fillers <NUM> in all of the respective openings <NUM> of the tubular section <NUM>. In other embodiments, the fillers <NUM> may be disposed within just selective openings <NUM> (i.e., not all of the openings <NUM>) of tubular section <NUM>.

<FIG> illustrates a cross-sectional view along the line labeled B-B in <FIG> of the tubular section <NUM>. As shown in the figure, the fillers <NUM> are respectfully disposed within the openings (e.g., slots) <NUM>. When contained within the opening <NUM>, each filler <NUM> is in abutment against two opposite surfaces <NUM> that define the opening <NUM>. In the illustrated embodiments, each filler <NUM> is fixedly secured to the two opposite surfaces <NUM> that define the opening <NUM>. The securing may be accomplished using an adhesive, glue, friction, etc. In some embodiments, each filler <NUM> completely fills an entirety of a corresponding opening <NUM>. In other embodiments, each filler <NUM> fills only a portion of the opening <NUM>.

As shown in <FIG>, the fillers <NUM> do not extend beyond the boundaries of the respective openings <NUM>. In particular, the tubular section <NUM> comprises a lumen <NUM> defined by an inner surface <NUM> of the wall <NUM> of the tubular section <NUM>, and the fillers <NUM> do not extend past the inner surface <NUM> into the lumen <NUM>. Also, the wall <NUM> of the tubular section <NUM> comprises an exterior surface <NUM>, and the fillers <NUM> do not extend past the exterior surface <NUM>. Thus, the fillers <NUM> stay between the exterior surface <NUM> and the inner surface <NUM> of the tubular section <NUM>. This configuration is advantageous because it prevents fluid outside the tubular section <NUM> from entering into the lumen <NUM> through the openings <NUM>, and vice versa, without requiring a layer of sealing material to be disposed on the exterior surface <NUM> or on the inner surface <NUM>. Since the tubular section <NUM> is free of any outer jacket, coating, liner or their like, the lumen of the tubular section <NUM> may have a relative larger cross-sectional dimension (e.g., diameter) for a given cross-sectional dimension of the tubular section <NUM> to be achieved. Also, because the inner surface <NUM> of the tubular section <NUM> is free of any coating, liner, or their like, the lumen <NUM> of the tubular section <NUM> may have a relatively larger cross-sectional dimension (e.g., diameter). Having a larger lumen <NUM> for the tubular section <NUM> of the elongated member <NUM> is advantageous because it may allow higher volume or quantity of substance to be transported via the lumen <NUM>. For example, neurovascular aspiration catheter may benefit from a larger diameter of the lumen <NUM> for aspiration of blood clots in the vasculature, than they would be otherwise when the catheter includes an outer jacket, coating, or liner at the exterior surface <NUM> or at the inner surface <NUM>.

In some embodiments, the fillers <NUM> may be flushed with the inner surface <NUM> of the tubular section <NUM>, and / or the exterior surface <NUM> of the tubular section <NUM>. In other embodiments, the fillers <NUM> may be recessed with respect to the inner surface <NUM> and/or the exterior surface <NUM> of the tubular section <NUM>.

In some embodiments, the fillers <NUM> disposed within the openings <NUM> are compressible and stretchable. In some cases, a filler <NUM> is considered as "compressible" if it undergoes a reduction in volume under compression. As shown in <FIG>, when the tubular section <NUM> is in a straight configuration, the fillers <NUM> are in a neutral configuration (e.g., they are not stretched or compressed). As shown in <FIG> and <FIG>, when the tubular section <NUM> bends, the fillers <NUM> on one side of the tubular section <NUM> are stretched due to that side of the tubular section <NUM> being in tension, and the fillers <NUM> on the opposite side of the tubular section <NUM> are compressed due to that side of the tubular section <NUM> being in compression. In particular, when the tubular section <NUM> bends, as shown in <FIG> and <FIG>, the tubular section <NUM> has a tension side <NUM> and a compression side <NUM>. The fillers <NUM> on the tension side <NUM> of tubular section <NUM> are stretched in correspondence with an increase in the distance between adjacent annular segments <NUM> on the tension side <NUM> due to the bending of the tubular section <NUM>. At the same time, the fillers <NUM> on the compression side <NUM> of tubular section <NUM> are compressed in correspondence with a decrease in the distance between adjacent annular segments <NUM> on the compression side <NUM>.

In some embodiments, each filler <NUM> on the tension side <NUM> is stretchable by an amount that allows the filler <NUM> to remain secured to both opposite sides of the opening <NUM> as the two opposite sides (or surfaces <NUM>) move apart from each other due to the bending of the tubular section <NUM>. Each filler <NUM> on the compression side <NUM> is also compressible by an amount that allows the filler <NUM> to stay within the opening <NUM> (e.g., without being squeezed out of the opening <NUM>) as the two opposite sides (or surfaces <NUM>) of the opening <NUM> move towards each other due to the bending of the tubular section <NUM>.

In some embodiments, each filler <NUM> has an uncompressed (neutral) volume, and each filler <NUM> is compressible to reach a compressed volume that is less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, or less than <NUM>% of the neutral volume. Also, in some embodiments, each filler <NUM> has an unstretched (neutral) volume, and each filler <NUM> is stretchable to reach a stretched volume that is more than <NUM>%, more than <NUM>%, more than <NUM>%, more than <NUM>%, more than <NUM>%, or more than <NUM>%, of the neutral volume. In other embodiments, each filler <NUM> may be compressible and/or stretchable to reach a strain (compression strain or tensile strain) that is at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, at least <NUM>, wherein a strain is defined as a change in length of the filler <NUM> divided by the original length of the filler <NUM> (e.g., strain = change in length / original length).

It should be noted that the fillers <NUM> are advantageous because they plug the openings <NUM> to prevent fluid transfer across the wall of the tubular section <NUM>, while also allowing the tubular section <NUM> to be more flexible (compared to the solution in which a jacket or a coating is applied to cover the openings <NUM>). As a result, the tubular section <NUM> can navigate through relatively tight bends without breaking or permanently deforming the tubular section <NUM>. As shown in <FIG>, the tubular section <NUM> may bend to form a first curvature as the tubular section <NUM> is moved through a blood vessel with a first bend. As shown in <FIG>, the tubular section <NUM> may further bend to form a second curvature that is larger than the first curvature as the tubular section <NUM> is moved through a blood vessel with a tighter or sharper turn. Regardless of the curvature formed by the tubular section <NUM>, the fillers <NUM> on both the tension side <NUM> and compression side <NUM> stay within the openings (e.g., slots) <NUM>, and allow the annular segments <NUM> to maintain aligned with each other. As a result, an annular segment (e.g., ring) is prevented from overlapping an adjacent annular segment (e.g., ring), and/or any annular segment is prevented from moving into the lumen <NUM> of the tubular section <NUM>.

Also, implementing fillers <NUM> using a compressible material is advantageous over using an incompressible material (i.e., material that displaces without going through volume change in response to compression). This is because openings of a slotted tube filled by incompressible material may result in a tube that is more stiffed than desired, or may result in a tube having undesirable bending characteristics. In some cases, such may be compensated by attempting to cut out more materials from the tube. However, such technique may have an adverse impact on other desired properties, such as hoop strength, torque transmission capability, etc..

Various techniques may be employed to place and secure the fillers <NUM> in the respective openings <NUM>. In some embodiments, the fillers <NUM> may be disposed within the slots <NUM> of the tubular section <NUM> by spaying or dipping the tubular section <NUM> in a suitable polymeric solution, allowing the solution to fill in the slots. After the solution dries or cured, it then becomes the fillers <NUM> within the slots <NUM>. Any excess solution (in wet or dry form) may be removed from the tubular section <NUM>. In other embodiments, the fillers <NUM> may be individually formed components that are individually inserted into the slots <NUM>, and are individually secured to the respective slots <NUM>, after the fillers <NUM> are formed.

As noted, the elongated member <NUM> with the tubular section <NUM> is not limited to the examples described. For example, in other embodiments, instead of the tubular section <NUM> being configured as a part of a delivery tube (e.g., catheter), the tubular section <NUM> may be any implant, such as a coil. In such cases, the opening <NUM> may be the spacing between adjacent loops of the coil. The coil may be abutted by a push wire or delivery wire, or may be detachably coupled to the push wire or the delivery wire. The coil may be configured (e.g., sized and/or shaped) to be placed in a blood vessel, and may be utilized to treat a condition inside a vasculature. For example, the coil may be used to fill a cavity of an aneurysm. In some embodiments, the filler(s) <NUM> is configured to be disposed within the spaces between adjacent loops of the coil. The filler(s) <NUM> allows the coil to navigate sharp bends while the loops of the coil stay aligned as the coil undergoes bending. Since the loops of the coil do not move transversely relatively to each other during bending of the coil, the outer surface of the coil remain substantially even. Exemplary coils for medical use are disclosed and described in <CIT>.

Also, as described in some embodiments, the fillers <NUM> do not extend beyond the boundaries of the respective openings <NUM>. However, in other embodiments, the filler <NUM> may extend beyond the boundary of the opening <NUM>. For example, in other embodiments, the filler(s) <NUM> may extend past the inner surface of the wall of the tubular section <NUM> into the lumen <NUM>, and/or does may extend past the exterior surface of the wall of the tubular section <NUM>. In addition, in some embodiments, the part of the filler <NUM> extending beyond the boundaries of the opening <NUM> may be a bump, an elongated protrusion, a block, or may have a random shape (for example, in some cases, the part of the filler <NUM> extending beyond the boundary of the opening <NUM> may be a manufacturing artifact). In still further embodiments, a part of the filler <NUM> extending past the interior surface of the tubular section <NUM> may extend to an inner layer disposed on the interior surface of the tubular section <NUM>, wherein the part of the filler <NUM> may be separately attached to the inner layer, or may be formed integrally with the inner layer. In further embodiments, a part of the filler <NUM> extending past the exterior surface of the tubular section <NUM> may extend to an outer layer disposed on the exterior surface of the tubular section <NUM>, wherein the part of the filler <NUM> may be separately attached to the outer layer, or may be formed integrally with the outer layer. In other embodiments, the filler <NUM> may have a first part extending past the exterior surface of the tubular section <NUM>, and a second part extending past the interior surface of the tubular section <NUM>. In such cases, the first part of the filler <NUM> may be separately attached to an outer layer disposed on the exterior surface of the tubular section <NUM>, and the second part of the filler <NUM> may be separately attached to an inner layer disposed on the interior surface of the tubular section <NUM>.

Also, in some embodiments, any of the filler(s) <NUM> described herein may be made from a closed cell material. In some applications, it may be desirable to use closed cell material for the filler(s) <NUM>. For example, a catheter may be required to have certain pressure resistance, such as, for resisting aspiration (negative) pressure, and/or for injection (positive) pressure. Closed cell material is advantageous for implementing the filler(s) <NUM> because it does not allow a fluid leakage pathway under pressure differential. In other embodiments, the filler(s) <NUM> may be made from an open cell material (e.g., open cell foam). In such cases, if fluid leakage prevention is desired, an inner liner and/or an outer liner (jacket) may be added to the tubular structure with the fillers <NUM>. The inner liner may be a polymer inner liner in some embodiments. Also, the outer liner (jacket) may also be made from a polymer in some embodiments. Alternatively, or additionally, the open cell material may have a low quantity of open cells (e.g., bubbles or cavities within the material), so that the cells (e.g., cavities) do not connect to form a pathway through a thickness of the filler <NUM>. In some embodiments, a gassing and/or degassing process may be performed during manufacturing to achieve a certain degree of bubble and/or bubble bursting, which influences how open the cellular structure for the open cell material will be. In other embodiments, a mechanical process, such as laser cutting may be utilized to create the open cell structure.

In addition, in the embodiments in which the device <NUM> is a catheter, the elongated member <NUM> may be implemented using a tube (e.g., hypotube) with a cut pattern. In some embodiments, such cut pattern may be a laser cut pattern. Also, in some embodiments, the tube with the cut pattern may provide one or more mechanical requirements (e.g., axial stiffness, hoop strength, bending stiffness, bending radius, torsional stiffness, etc., or any combination of the foregoing) without relying on mechanical properties of the fillers <NUM>. In some embodiments, the fillers <NUM> may be made from a material having an elastic modulus that is less than <NUM>%, or less than <NUM>%, or less than <NUM>% or less than <NUM>%, or less than <NUM>%, or less than <NUM>%, or less than <NUM>%, of the elastic modulus of the material of the tube (implementing the elongated member <NUM>). This allows the fillers <NUM> to be significantly more compressible than the material of the tube.

Using compressible material to implement the fillers <NUM> is advantageous because it allows the fillers <NUM> to not interfere with the mechanical properties of the tube. In some cases, when designing a catheter, it may be desirable to provide the proximal portion of the catheter with higher stiffness. Such may be implemented using a tube with no slots at the proximal portion. However, such a design may not meet the bending radius requirement. Accordingly, it may be desirable to add some slots to allow the proximal portion of the tube to achieve a desirable stiffness as well as the bending radius requirement. In such a design, if incompressible fillers are used to fill the slots, the bending stiffness of the catheter formed from the tube may be adversely affected, because the incompressible fillers may increase the bending stiffness of the catheter. To compensate for this, wider slots may be implemented at the tube, but widening the slots may reduce the stiffness at the proximal portion of the tube, and may also increase manufacturing cost. Use of compressible fillers <NUM> is advantageous because it may obviate the need to use the "wider slots" solution, while still allowing desired stiffness and bending radius to be achieved for the proximal portion of the tube (with the fillers <NUM>).

Also, in some cases, when designing a catheter, it may be desirable to provide the distal portion of the catheter with less stiffness to achieve easier bending (compared to a proximal portion). Such may be implemented using a tube made from soft polymer. However, such a design may not meet the kink resistance requirement, and may have low hoop strength for the distal portion of the tube. Accordingly, it may be desirable to implement the distal portion of the tube using stiff hoop elements, such as metal rings / coils, metal braiding, or metal sections from cut metal tube (for achieving a desired hoop strength). The hoop elements may be spaced enough to allow the distal portion of the tube to bend with a tight bending radius (e.g., achieving <NUM>-degree bend, <NUM>-degree bend, or even <NUM>-degree bend). In such a design, the wall of the tube may be thickened in order to meet column strength and tensile property requirements. However, thickening the wall of the tube may increase bending stiffness, may negatively affect the bending radius requirement, may increase the overall size of the device, and/or may reduce the lumen size of the catheter. Also, in such a design, if incompressible fillers are used to fill the slots, the bending stiffness and bending radius of the catheter may be adversely affected, because the incompressible fillers may increase the bending stiffness of the catheter, making the catheter more resistant to bending. Use of compressible fillers <NUM> is advantageous because it may allow desired bending stiffness, column strength, and bending radius of the tube (with the fillers <NUM>) be achieved, while obviating the need to thicken the wall of the tube.

Furthermore, in some embodiments, the width of the openings (e.g., slots) at the elongated member <NUM> for accommodating the fillers <NUM> may have a width that is anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>. Also, in some embodiments, the width of the openings (e.g., slots) at the distal end of the elongate member <NUM>, may be different from (e.g., smaller than) the width of the openings that are proximal to the distal end. For example, in some embodiments, the width of the openings accommodating the fillers <NUM> may be anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>, at the distal end of the elongate member <NUM>, and another portion (e.g., a proximal end) of the elongate member <NUM> proximal to the distal end of the elongate member <NUM> may have width of openings that is anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM>, or anywhere from <NUM> to <NUM> (e.g., <NUM>).

Claim 1:
A catheter, comprising:
an elongated member (<NUM>) having a proximal end (<NUM>), a distal end (<NUM>), and a body (<NUM>) extending between the proximal end (<NUM>) and the distal end (<NUM>);
wherein the elongated member (<NUM>) comprises a tubular section (<NUM>) having a plurality of openings (<NUM>), in the form of slots extending into a wall of the tubular section (<NUM>), the plurality of slots (<NUM>) comprising a first slot (<NUM>); and
wherein the elongated member (<NUM>) further comprises fillers (<NUM>) respectively located in the slots (<NUM>), the fillers (<NUM>) comprising a first filler, wherein the first filler comprises a spongy material located in the first slot (<NUM>);
wherein the first filler has an elastic modulus that is less than <NUM>% of an elastic modulus of a material of the tubular section (<NUM>), and wherein the first filler is compressible to reach a strain that is at least <NUM>;
wherein the first slot (<NUM>) is at the wall of the tubular section (<NUM>), the first slot (<NUM>) extending circumferentially around a longitudinal axis of the tubular section (<NUM>), and that the first filler having the elastic modulus is located in the first slot (<NUM>) extending circumferentially around the longitudinal axis of the tubular section (<NUM>)
characterized in that the spongy material in the first slot comprises a porous material.