Patent Description:
The general use of catheters as medical devices is fairly well-developed at this point. <CIT>, for example, shows the use of a guide catheter for insertion into an artery to assist with treating the artery (e.g. with a stenosis); and it further shows the use of another catheter for telescoping insertion into the first catheter to extend beyond the first catheter to treat or access portions of the artery that the first catheter cannot reach because of its larger diameter or lack of flexibility, trackability or support. Subsequent patents show further developments of such telescoping or extension catheter systems. For example, <CIT>, <CIT>, and <CIT>all show the use of a catheter having a tubular portion that extends or telescopes beyond the guiding catheter, and an elongated manipulation/insertion wire or shaft attached to the tubular portion to manipulate the tubular portion axially - in push / pull fashion - within the guiding catheter after it has been inserted through the hemostasis valve and into the guiding catheter. The Adams '<NUM> patent suggests that the proximal manipulation/insertion wire may actually be a low-diameter tubular shaft for conducting fluid to inflate and deflate a restriction balloon that restricts movement of the tubular portion.

Certain known extension catheters have proximal shafts that transfer twisting motion (also referred to as "torque") by the user from the proximal shaft to the distal tube. In addition, torsion is also generated along the proximal shaft of such devices as a result of urging the catheter distally or proximally through the guiding catheter and further through tortuous vasculature. However, this transmission of torque can induce stresses on the connection between the proximal shaft and the tube, in some cases stresses that are so great that the stresses cause failure or separation of the shaft and tube at the connection point. Thus, the torque generated at the connection point as a result of the low torsional compliance characteristics (including, for example, high torque transmission) of these devices coupled with the tensile or compressive forces generated from urging the catheter axially can cause device failures. Many of these known catheters have proximal shafts with low torsional compliance, thus making them susceptible to the problems described above.

Further, many of the catheters discussed above are multi-layer catheters. A multi-layer catheter is a catheter having a multi-layer tubular construction. Many known catheters can have such a multi-layer tubular construction, including guiding catheters, sheaths, guide extension catheters, and boosting catheters, for example. Typically, the multi-layer catheters have at least two layers: an inner liner layer and an outer layer. In many cases, the inner liner layer is a lubricious liner that is intended to facilitate the passage of other devices through the inner lumen of the catheter. Such an inner layer is often made of PTFE, but can also be made of Teflon, polyethylene, or any other known material that can be incorporated into a medical device.

One disadvantage of a multi-layer catheter is the possible delamination that can occur between layers. That is, one or more layers of the multi-layer catheter tube begin to separate from the rest of the layers. This is especially common with lubricious layers. For example, the distal end <NUM> of a typical known multi-layer tubular catheter <NUM> with exposed ends of the layers is shown in <FIG>. Note that the catheter has an inner layer <NUM> and an outer layer <NUM>, and both layers are exposed at the distal end <NUM> of the catheter <NUM>. As shown in <FIG>, one common problem with multi-layer catheters is delamination of the inner layer <NUM> from the adjacent layer (in this case, the outer layer <NUM>), such as at the distal end <NUM> as shown. According to one exemplary scenario, the delamination can occur during use of the catheter <NUM> when the tube is being flexed or advanced through the vasculature. A result of such a delamination is that passage (especially withdrawal) of a device through the distal tip may be impaired.

Another disadvantage of a catheter having a proximal shaft coupled to a distal tube is that the typically metallic proximal or manipulation shaft may shear, delaminate, peel or disconnect from the distal tube during use.

Accordingly, there has been a need in the art for improved catheters and/or improved catheter tips and related methods and systems.

<CIT> discloses medical devices and methods for making and using medical devices.

<CIT> discloses a boosting catheter for positioning through a guiding catheter into the vasculature of a patient, the boosting catheter having a distal tubular member and a proximal elongated shaft coupled to the distal tubular member.

<CIT> discloses a guide extension catheter including a proximal shaft having a proximal end and a distal end, the distal end having an attachment region.

<CIT> discloses an indwelling catheter for insertion into a patient's urinary tract that includes first and second tubular members.

<CIT> discloses a balloon catheter device including an elongate catheter shaft comprising multifilar cable tubing having a proximal portion and a distal portion.

The present invention provides a catheter according to claim <NUM>.

Discussed herein are various catheter embodiments for use with standard guiding catheters and sheaths.

As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the scope of the present invention.

The various embodiments disclosed and contemplated herein relate to a catheter, such as an extension guide catheter, having a length or section containing a discontinuous or segmented structure. Further embodiments relate to catheters having such discontinuous or segmented structures that can be modified or varied to modify the torsional compliance characteristics of the device. Certain of these catheter embodiments can be adapted to be positioned through and extend distally from a conventional guiding catheter or sheath, wherein the guiding catheter or sheath is adapted to extend into a patient.

Further embodiments disclosed and contemplated herein relate to an improved catheter tip that can be incorporated into any known multi-layer catheter, including an extension catheter, guiding catheter, sheath, delivery catheter, or any other such catheter.

Additional embodiments disclosed and contemplated herein relate to a support layer than can be positioned around a portion of any known catheter to provide additional strength and/or support to the catheter.

Further implementations disclosed and contemplated herein relate to an improved proximal portion of a catheter tube that can be incorporated into any known multi-layer catheter, including an extension catheter, guiding catheter, sheath, delivery catheter, or any other such catheter.

For purposes of the remainder of this application, it is understood that the term "guiding catheter" relates to any known guiding catheter, sheath, or delivery system. Additionally, for purposes of this application, "extension catheter" and "extension guide catheter" shall mean any catheter that can be used in combination with a guiding catheter to perform a procedure, including a boosting catheter. It is understood that the various embodiments disclosed herein can be incorporated into any extension catheter, but also can be incorporated into other types of catheters as well.

<FIG> depicts a conventional guiding catheter <NUM> being used in the general operating environment, which is partially within a human body, and usually within an artery or vein. As shown in the figure, the guiding catheter <NUM> may be inserted into the vasculature through a number of different access points in the body. For example, a femoral artery approach is shown at A, while a radial artery approach is shown at B. Further, other parts of the vasculature may be accessed with various guiding catheters or sheaths. For example, at C, a sheath is shown inserted through the femoral artery for a contralateral approach for procedures in the leg or other parts of the body. In another example, the sheath is inserted through the femoral artery to access the renal arteries in one of the kidneys at D or to access the coronary vasculature.

Regardless of the access point or the target portion of the vasculature, certain catheter implementations disclosed herein are extension catheter embodiments that can be used in combination with guiding catheters to assist with various procedures. For example, the extension catheter embodiments in combination with guiding catheters can be used to assist with the passage of other interventional, diagnostic, or therapeutic devices to various locations in the vasculature. In other instances, the various types of catheters can be used in combination with guiding catheters or sheaths to assist with the transmission of contrast, diagnostic, or therapeutic fluids/agents by injecting the fluids/agents through the catheter to various locations, or by transmitting the fluids/agents through the guiding catheter via a hemostasis valve adaptor and subsequently passing it through the distal tube of the catheter. In another example, the various catheter types in combination with guiding catheters or sheaths can be used to assist with the removal of thrombus, emboli, or debris present in the vasculature through the guiding catheter/sheath by applying a vacuum at the proximal end of the guiding catheter/sheath via a hemostasis valve adaptor. Alternatively, other catheter implementations are contemplated.

As shown in <FIG> and <FIG>, various embodiments of an extension catheter (generally shown at <NUM>) as disclosed and contemplated herein can be used in conjunction with any conventional guiding catheter <NUM> for purposes of the various procedures described above. Generally, the distal end of the extension catheter <NUM> is positioned through and extended distally from the distal end of the conventional guiding catheter <NUM>. As best shown in <FIG>, the various catheter embodiments, including catheter <NUM> as shown, have two basic parts: a distal portion that is a comparatively large diameter tube (generally indicated at <NUM>) defining a lumen <NUM> and adapted to extend through and beyond the distal end of the guiding catheter; and a proximal portion that is a comparatively smaller diameter elongate member, also referred to herein as a "manipulation shaft" (generally indicated at <NUM>), connected to the tubular portion <NUM> at a junction.

In the various implementations disclosed or contemplated herein, the proximal elongated shaft <NUM> is made up of at least two rods. In certain embodiments, the proximal shaft also has a sheath disposed around the at least two rods, such that the two rods are disposed within or through the sheath. The sheath is any structure that forms a lumen that is configured to receive the two or more rods of the proximal shaft (such as shaft <NUM>) as disclosed or contemplated herein, and can also be referred to herein as a "tube. " In further embodiments, the sheath is discontinuous. That is, in those embodiments, at least one length of the two rods is not disposed within the sheath. In other implementations, the sheath can cover the entire length of the at least two rods.

In addition to serving as a mechanism for advancing the catheter in certain implementations, a manipulation shaft with at least two rods within a discontinuous sheath can have desirable torsional compliance characteristics, as will be explained in detail below. The torsional compliance characteristics of these embodiments can help to reduce incidence of stress at the joint or connection between the manipulation shaft and distal tube, thereby reducing the incidence of failure of that joint.

One example of an extension catheter embodiment <NUM> with a manipulation shaft <NUM> made up of two elongate members <NUM>, <NUM> and a sheath segment <NUM> is shown in further detail in <FIG>. The elongate members <NUM>, <NUM> can be rods, tubes, or any other type of elongate member that can be used to advance a catheter or other similar medical device. The two elongate members <NUM>, <NUM> in this embodiment are rods <NUM>, <NUM> that do not contain lumens and are positioned generally adjacent to each other. The sheath segment <NUM> is positioned around the two rods <NUM>, <NUM> such that the two rods <NUM>, <NUM> are positioned through the lumen <NUM> formed in the segment <NUM>. In this implementation, the sheath segment <NUM> has a length that is shorter than the length of the two rods <NUM>, <NUM> such that the entire length of the rods <NUM>, <NUM> is not covered by the sheath segment <NUM>. That is, in this embodiment, the rods <NUM>, <NUM> have an uncovered (or "unsheathed") distal portion 38A and an unsheathed proximal portion 38B, with the sheath segment <NUM> positioned between the two unsheathed segments 38A, 38B.

In this implementation, each of the rods <NUM>, <NUM> has a full diameter portion 30A, 32A and a reduced diameter portion 30C, 32C, with a transition portion 30B, 32B therebetween. As shown, the transition portions 30B, 32B in this embodiment are tapered portion 30B, 32B. In accordance with one implementation, the reduced diameter portions 30C, 32C can provide enhanced flexibility and are sized such that the diameter of the rods <NUM>, <NUM> at their reduced diameter portions 30C, 32C can be positioned within the wall <NUM> of the distal tube <NUM> as described below.

In this implementation, the manipulation shaft <NUM> is coupled to the distal tube <NUM> at a point or area of the wall <NUM> of the tube <NUM>. More specifically, as best shown in <FIG>, a distal portion of the shaft <NUM> is coupled to and integral with the wall <NUM> of the distal tube <NUM> at a connection zone <NUM>. The connection zone (also referred to as the "coupling zone" or "transition zone") <NUM> is the portion or length of the proximal end of the distal tube <NUM> in which a length of the manipulation shaft <NUM> is coupled or otherwise positioned. In this specific embodiment, as best shown in <FIG>, the two rods <NUM>, <NUM> extend into the distal tube <NUM>. More specifically, the distal portion <NUM> of rod <NUM> is disposed in one portion of the wall <NUM> in the connection zone <NUM> of the distal tube <NUM> while the distal portion <NUM> of rod <NUM> is disposed in another portion of the wall <NUM>, as will be described in further detail below.

Further, in this implementation as best shown in <FIG>, both distal portions <NUM>, <NUM> are positioned in the connection zone <NUM> in a specific configuration. More specifically, each of the distal portions <NUM>, <NUM> has an angled portion <NUM>, <NUM> that extends at an angle in relation to the longitudinal axis of the tube <NUM> and an axial portion <NUM>, <NUM> that extends axially for some distance as well, as shown. As shown, in this configuration, the proximal ends of the distal portions <NUM>, <NUM> in the connection zone <NUM> are substantially adjacent to each other in the wall <NUM>. In contrast, the angled portions <NUM>, <NUM> of the distal portions <NUM>, <NUM> are farther apart from each other. That is, the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> are positioned such that they are farther apart from each other at the distal ends of the distal portions <NUM>, <NUM> in comparison to the proximal ends. Thus, in accordance with one implementation, the axial portions <NUM>, <NUM> of the distal portions <NUM>, <NUM> are positioned in the wall <NUM> contralaterally in relation to each other. That is, the axial portion <NUM> of rod <NUM> is disposed in the wall <NUM> on one side of the tube <NUM> while the axial portion <NUM> is disposed in the wall <NUM> on the other side of the tube <NUM> such that the portions <NUM>, <NUM> are positioned across the lumen <NUM> from each other.

Further, according to certain embodiments, the distal portions <NUM>, <NUM> positioned in the connection zone are configured to be substantially flat or have a reduced cross-sectional profile that allows the distal portions <NUM>, <NUM> to be positioned within the wall <NUM> of the tube <NUM> as described herein. Alternatively, other configurations are also contemplated.

For example, <FIG> depict alternative embodiments of the distal portions <NUM>, <NUM> of rods <NUM>, <NUM>. It should be noted that while these two embodiments are depicted without any sheaths or sheath segments, it is understood that either or both can have one or more sheath segments or a single sheath that extends along the entire length of the rods <NUM>, <NUM> or any portion thereof. In <FIG>, the distal portions <NUM>, <NUM> in the connection zone <NUM> are straight. That is, there are no angled or curved portions. Alternatively, in <FIG>, the distal portions <NUM>, <NUM> have a gradual curve configuration. As shown, the rods <NUM>, <NUM> in <FIG> are round. Alternatively, the distal portions <NUM>, <NUM> can be flattened or have a reduced cross-sectional profile. Further, in certain implementations, the distal portions <NUM>, <NUM> can have geometrical features (such as barbs, notches, holes, etc.) that may enhance the retention of the rods <NUM>, <NUM> within the tube. In further alternatives, the distal portions <NUM>, <NUM> can have multiple curves or bends and can either be round or flattened.

In accordance with one implementation, the positioning and configuration of the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> in the connection zone <NUM> in the wall <NUM> of the distal tube <NUM>, according to any of the embodiments depicted in <FIG>, can enhance the kink resistance of that portion of the tube <NUM> as well as assisting in transmitting a distal or proximal force to the distal tube <NUM> in a more even fashion during use of the catheter <NUM>. Further, in a similar fashion to the geometrical features discussed above, the configuration of the distal portions <NUM>, <NUM> can also enhance the retention strength of the connection between the manipulation shaft <NUM> and the distal tube <NUM> by increasing the surface area of the connection and thereby further distributing the stresses placed upon the connection when forces are applied to the manipulation shaft <NUM> (or the distal tube <NUM>).

As discussed above, the rods <NUM>, <NUM> in the embodiments depicted in <FIG> and <FIG> are solid rods (that is, they do not have lumens therein). In another embodiment as shown in <FIG>, the rods <NUM>, <NUM> are tubes <NUM>, <NUM>, with each of the tubes <NUM>, <NUM> having lumens defined therein. Further, in the embodiment of <FIG> as best shown in <FIG>, the two rods <NUM>, <NUM> are disposed within the sheath <NUM> such that the sheath segment <NUM> has a lumen <NUM>. More specifically, this particular configuration of the sheath <NUM> with two rods <NUM>, <NUM> positioned adjacent to each other within the sheath <NUM> has two lumens 36A, 36B.

In alternative implementations, other configurations of the manipulation shaft <NUM> are possible, as shown in <FIG>. For example, as shown in <FIG>, the two rods <NUM>, <NUM> can have lumens <NUM>, <NUM> defined therein (rather than being solid rods). In this implementation, the rods <NUM>, <NUM> can be hypotubes <NUM>, <NUM>, with each having a lumen <NUM>, <NUM> defined therein. In addition, like the solid rods <NUM>, <NUM> depicted in <FIG>, the sheath segment <NUM> also has two lumens 36A, 36B defined between the rods <NUM>, <NUM> and the sheath <NUM>. Further, it is understood that any of the sheath segment embodiments disclosed or contemplated herein with two or more elongate members may also have lumens in the spaces created by the elongate members disposed therein.

Further, <FIG> show that the shaft <NUM> can, in certain embodiments, have various configurations relating to the number, shape, and size of the elongate members. For example, in the implementation of <FIG>, the shaft <NUM> has a sheath segment <NUM> with two large rods <NUM>, <NUM> and one small rod <NUM>. Further, the sheath <NUM> also has lumens 70A, 70B, 70C, 70D defined within the sheath <NUM> as a result of the configuration of the rods <NUM>, <NUM>, <NUM>. Each elongate member <NUM>, <NUM>, <NUM> disposed within the sheath <NUM> provides additional support or reinforcement to the shaft <NUM> while also resulting in multiple lumens within the segment <NUM>. Alternatively, as shown in <FIG>, the shaft <NUM> can have the same configuration, except that the small rod <NUM> is a tube <NUM> having a lumen <NUM>. Additional configurations are shown in <FIG>, including configurations with rods that are not round, but instead are square, rectangular, triangular, hexagonal, or other shapes or combinations thereof. Alternatively, any of the rods can be any known shape. As shown in these figures, the configuration, shape, and number of rods can also influence the cross-sectional shape or profile and the torsional characteristics of the segment <NUM>.

In the various implementations disclosed or contemplated herein, the one or more lumens defined within the sheath segments (such as lumens 36A, 36B and lumens 70A, 70B, 70C, 70D described above) extend along the entire length of the sheath segment (such as segment <NUM> and segment <NUM>).

According to certain embodiments, a filler material such as an adhesive, binding material, or polymer can be injected or otherwise positioned within one or more of the lumens (such as lumens 36A, 36B, or 70A, 70B, 70C, 70D) and serve as a bonding agent. The filler material can provide additional structural support for the shaft <NUM>. Alternatively, the filler material can be a lubricant. The filler material can fill an entire lumen of a sheath segment (such as one or more of the lumens 36A, 36B or lumens 70A, 70B, 70C, 70D), the entire length of all of the lumens of a segment and/or all the segments, a portion of each of the lumens of each segment, only a portion of the length of any segment, or two or more portions of the length of any segment or all segments. Further, it is understood that the filler material can fill one sheath segment (such as one sheath segment of segments 88A, 88B of <FIG>, segments 92A, 92B, 92C, 92D of <FIG>, or segments 96A, 96B of <FIG>, for example), two sheath segments (such as two segments of segments 88A, 88B, segments 92A, 92B, 92C, 92D, or segments 96A, 96B, for example), or any other number of segments. In addition, it is also understood that the filler material can fill all sheath segments on a device.

In accordance with certain alternative implementations as will be described in further detail below, the one or more lumens (such as lumens 36A, 36B or 70A, 70B, 70C, 70D), including, for example, the lumens in the elongate members (such as lumens <NUM>, <NUM> as shown in <FIG>), can be configured to receive a fluid (such as, for example, a contrast solution) such that the fluid can be urged from the proximal end to the distal end of the segment (such as segment <NUM> or <NUM>) and thereby dispense or deliver the fluid out of the distal end of the segment.

There can be benefits of a proximal shaft having a lumen. As discussed above, it allows for transmission of fluid through a conduit that is smaller in diameter than the guiding catheter. In certain embodiments, the lumen is sized specifically to conduct the desired amount of a specific fluid into the distal tube, into an area proximal to the opening of the distal tube, into a wall of the distal tube, out of the wall of the distal tube through an opening somewhere along the length of the tube, or out of the distal end of the distal tube. The control of the lumen size can allow for transmission of more or less fluid, depending on what is desired. For example, less fluid can be desirable when the fluid is contrast solution that is typically used in several catheter-based procedures, because greater amounts of contrast solution can cause harm to the patient.

According to various embodiments, the manipulation shaft <NUM> can have a diameter that ranges from about <NUM> inches (<NUM> millimetres) to about <NUM> inches (<NUM> millimetres). Alternatively, the shaft <NUM> can have a diameter that ranges from about <NUM> inches (<NUM> millimetres) to about <NUM> inches (<NUM> millimetres). Further, the shaft <NUM> can have a size that ranges from about <NUM>/<NUM> <CIT> millimetres) to about <NUM> French (<NUM> millimetre). The various inner elongate members can be made of at least one metal and/or at least one polymer. The metal can be stainless steel, nitinol, or other similar metals. Specific examples of stainless steel include <NUM> or <NUM> grade stainless steel. In those embodiments with inner elongate members, the outer wall, sheath, or sheath segment of the shaft <NUM> is made of polymeric materials such as PET, PTFE, Teflon, FEP, PE, PEBA, or other similar materials.

The various manipulation shaft or sheath embodiments as discussed in further detail elsewhere herein provide for a gradual change in flexibility from the proximal end of the shaft to the distal end. Further, certain shaft implementations are configured such that the distal portion of the shaft couples with the distal tube in such a way as to maximize the inner diameter of the distal tube. That is, in certain implementations, the various catheter implementations disclosed or contemplated herein require a sufficiently accessible opening at the proximal end of the distal tube to allow for the lumen to be accessible for medical devices. In other words, the opening must be large enough and/or have sufficient clearance to allow for easy insertion of various medical devices into the opening such that the devices can be urged distally through the tube and out of the opening at the distal end of the tube. In certain of these embodiments, clearance at the opening at the proximal end of the distal tube can be optimized by minimizing the profile (by reducing the diameter, etc.) of the manipulation shaft according to various configurations as disclosed herein.

As mentioned above, in accordance with some embodiments, the distal portion of the manipulation shaft is integrated or embedded in the proximal end of the distal tube. For example, in certain implementations, the distal tube is molded over the distal end of the manipulation shaft, thereby creating a connection zone as discussed elsewhere herein.

Returning to <FIG>, the larger diameter distal tube <NUM> is, according to one embodiment, made generally from flexible polymeric materials. In certain implementations, the tube <NUM> is constructed with at least two layers. For example, the tube <NUM> can have two layers: a PEBAX, polyurethane, or NYLON outer layer, and a PTFE inner layer. Alternatively, the tube <NUM> can include a third polymeric layer (or more than three such layers). The tube <NUM> may also incorporate another layer comprised of re-inforcing coil or mesh. Such a coil or mesh layer can provide enhanced flexibility and/or strength. The tube <NUM> may also incorporate radiopaque markers (such as markers <NUM>, <NUM>, <NUM> as shown in <FIG> and discussed below) on the tube <NUM>. The manipulation shaft <NUM> may also incorporate one or more visual markers, including radiopaque markers.

The number and configuration of the elongate members and the one or more sheath segments (and any filler material positioned therein) in the manipulation shaft can influence the physical characteristics of the catheter. More specifically, these components can directly influence the torsional compliance characteristics of the device. It is understood that for purposes of this application, "torsional compliance" is intended to mean the angular or rotational flexibility of the shaft along its length. As an example, a shaft with high torsional compliance will transmit less torque or rotation from one end to the other end, while a shaft with low torsional compliance will transmit more torque from one end to the other. A shaft with low torsional compliance will have higher torque transmission charactistics than one with high torsional compliance. As discussed above, certain known extension catheters have high torque transmission characteristics (and thus low torsional compliance characteristics) that can cause sufficient stress on the connection between the proximal shaft and distal tube to cause failure or separation at the connection point. Non-limiting examples of extension catheters having low torsional compliance can include catheters having a proximal shaft comprised of a single elongate member having a solid square or rectangular cross-section, a solid round cross-section, or a round cross-section with a lumen (such as a hypotube).

In contrast, the use of two or more elongate members in combination with different sheath segment configurations can produce higher torsional compliance (and thus lower torque transmission) than proximal shafts that are not configured as such. More specifically, without being limited by theory, the capability of the two or more elongate members to move independently in relation to each other helps to increase torsional compliance/reduce torque transmission when the manipulation shaft is turned at its proximal end by the user to cause rotation of the distal tube or when torsion is induced in the shaft as a result of pushing (or pulling) the catheter through a guiding catheter and through a tortuous vessel. In a related fashion, a sheath segment that covers only a portion of the length of the elongate members (instead of the entire length thereof) also maintains some independent movement of the elongate members, thereby maintaining lower torque transmission in comparison to any configuration that includes a sheath that covers the entire length of the elongate members. In contrast, in those situations in which it is desirable, the addition of a filler material that acts as a bonding agent in one or more lumens of the sheath segment can decrease the torsional compliance characteristics (and thus increase the torque transmission characteristics), while a filler material that constitutes a lubricant can increase torsional compliance characteristics less than a bonding agent. As discussed above, the amount of filler can also influence the torsional compliance characteristics, including whether the filler fills the entire length of a sheath segment, a portion of the segment, more than one portion of the segment, or more than one segment.

Thus, it is understood that torsional compliance of any given device or shaft can be determined based on a number of factors, including the number and length of any sheath segments, the number and length of any unsheathed segments, the amount of filler, the type of filler, the cross-sectional shape of the two or more elongate members, the number of elongate members, and other known factors.

These concepts are best captured in <FIG>, which depicts a shaft <NUM> configuration with round rods <NUM>, <NUM> having a sheath segment <NUM> and an unsheathed segment <NUM>. The unsheathed segment <NUM> allows for the independent movement of two round elongate members <NUM>, <NUM>, thereby increasing torsional compliance as described above. That is, as shown by the fact that the proximal portions of the elongate members are wound together, the two elongate members can move independently in relation to each other - including being in sliding and rolling contact along their lengths - thereby increasing the torsional compliance of the shaft <NUM>. In contrast, non-round elongate members would not be capable of rolling or rotating in relation to each other as easily, thereby resulting in decreased torsional compliance as a result of the contact between elongate members being merely slidable in nature (rather than both sliding and rolling/rotating). Further, the sheathed segment <NUM> reduces the amount of relative movement of the two rods <NUM>, <NUM> such that their independent movement in relation to each other is more limited in comparison to the length of rods <NUM>, <NUM> in the unsheathed segment <NUM>, thereby resulting in decreased torsional compliance. Of course, it is understood that the two rods <NUM>, <NUM> in the sheathed segment <NUM> can also be in sliding and rolling contact along their lengths, but it is also understood that the rods <NUM>, <NUM> in the sheath <NUM> are not capable of rolling or rotating in relation to each other as easily as rods <NUM>, <NUM> of an unsheathed segment (such as segment <NUM>). And a filler injected into the segment <NUM> can further influence the torsional compliance as explained above.

Further, <FIG> depict various different additional manipulation shaft implementations, wherein each of the different configurations has a different impact on the torque transmission characteristics of the resulting device. More specifically, each of these figures shows a different embodiment of a manipulation shaft <NUM> having two elongate members <NUM>, <NUM>, with each embodiment having a different sheath segment configuration.

For example, <FIG> depicts a manipulation shaft <NUM> with the two elongate members <NUM>, <NUM>, but having no sheath segment. As described above, this shaft <NUM> would exhibit high torsional compliance (or low torque transmission) for the reasons set forth above.

<FIG> shows a manipulation shaft <NUM> with two elongate members <NUM>, <NUM> and a sheath segment <NUM> that is disposed around the two elongate members <NUM>, <NUM> for a substantial amount of the length of the members <NUM>, <NUM>. That is, the sheath segment <NUM> extends from a proximal portion of the members <NUM>, <NUM> to a distal portion of the members <NUM>, <NUM>. In this embodiment, the shaft <NUM> exhibits lower torsional compliance characteristics than any of the other embodiments in <FIG>, because the sheath <NUM> is disposed around a greater length of the two members <NUM>, <NUM> than any other embodiment, thereby limiting the freedom of the two members <NUM>, <NUM> to move in relation to each other. Alternatively, the sheath segment <NUM> can be disposed around the elongate members <NUM>, <NUM> for any length of those members <NUM>, <NUM>, including the entire length thereof. Further, as is true with any of the embodiments shown in <FIG> and elsewhere in this application, a bonding agent filler injected into the segment <NUM> will cause even lower torsional compliance characteristics (while a lubricant filler would have torsional compliance characteristics that are not as low as those created by a bonding agent).

The manipulation shaft <NUM> embodiments in <FIG> all have at least two sheath segments disposed around two elongate members <NUM>, <NUM>. More specifically, <FIG> depicts a first or distal sheath segment 88A, and a second or proximal sheath segment 88B, with an unsheathed segment <NUM> between the two segments 88A, 88B. The shaft <NUM> in <FIG> has four sheath segments 92A, 92B, 92C, 92D with three unsheathed segments 94A, 94B, 94C disposed therebetween. Further, <FIG> has two sheath segments 96A, 96B with an unsheathed segment <NUM> between the two segments 96A, 96B. The unsheathed segment <NUM> in <FIG> has a greater length than the unsheathed segment <NUM> in <FIG>, which means that the shaft <NUM> in <FIG> exhibits lower torque transmission than the shaft <NUM> in <FIG>. In a further alternative, the shaft <NUM> can have a sheath that is disposed around the two elongate members <NUM>, <NUM> and extends for the entire length of the shaft <NUM>, thus constituting a unitary or non-segmented sheath. Further, it is understood that the sheath or segments can have any length and cover any portion of the length of the shafts. It is also understood that there can be any number of sheath segments or unsheathed segements. In addition, certain embodiments can have at least two segments that are disposed around the at least two elongate members and adjacent to each other such that they in contact with each other such that there are no unsheathed segments between the at least two segments.

<FIG> depict another embodiment of a catheter <NUM> with a manipulation shaft <NUM> that is coupled to the distal tube <NUM> in an eccentric manner, rather than a concentric manner. That is, the shaft <NUM> is joined to the distal tube <NUM> at one point or in one zone of the periphery or circumference of the distal tube <NUM> or along an extension <NUM> of the distal tube <NUM> as discussed in further detail below. For example, in one implementation as shown in <FIG>, the manipulation shaft <NUM> is coupled to the distal tube <NUM> at a point or area of the wall <NUM> of the tube <NUM>.

The shaft <NUM> in this embodiment is made up of two rods <NUM>, <NUM> positioned within the lumen <NUM> of the sheath <NUM> disposed around the rods <NUM>, <NUM>, as best shown in <FIG>. In this embodiment, the rods <NUM>, <NUM> are solid (that is, they do not have lumens). Alternatively, as discussed above, the rods <NUM>, <NUM> can be hypotubes <NUM>, <NUM>, with each having a lumen defined therein, and/or can have a shape other than round.

As best shown in <FIG>, this specific implementation has a distal portion of the shaft <NUM> that is similar to the configuration of <FIG> as discussed above, because the shaft <NUM> is coupled to and integral with the wall <NUM> of the distal tube <NUM> at the connection zone <NUM>. Further, as best shown in <FIG>, like the device <NUM> in <FIG>, the two rods <NUM>, <NUM> extend from the distal portion of the shaft <NUM> such that the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> extend into the distal tube <NUM>. More specifically, the distal portions <NUM>, <NUM> are positioned in the wall <NUM> contralaterally in relation to each other. That is, the distal portion <NUM> is disposed in the wall <NUM> on one side of the distal tube <NUM> while the distal portion <NUM> is disposed in the wall <NUM> on the other side of the tube <NUM> such that the portions <NUM>, <NUM> are positioned across the lumen <NUM> from each other. As with every embodiment having contralateral distal portions, the distal portions <NUM>, <NUM> can be directly opposite each other across the lumen <NUM>, but in other implementations, they are not directly opposite each other.

Further, as best shown in <FIG>, both distal portions <NUM>, <NUM> (only <NUM> is visible in <FIG> because of the location of distal portion <NUM> behind distal portion <NUM> in the figure) have angled portions <NUM>, <NUM> that extend at an angle in relation to the longitudinal axis of the tube <NUM> and axial portions <NUM>, <NUM> that extend axially along that position for some distance as well as shown. Alternatively, the distal portions <NUM>, <NUM> can have only angled portions (similar to portions <NUM>, <NUM>) and no straight or axial portions. In accordance with one implementation, the positioning and configuration of the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> in the wall <NUM> of the distal tube <NUM> enhance the kink resistance of that portion of the tube <NUM> as well as assisting in more evenly transmitting an axial force to the distal tube <NUM> in a more even fashion during use of the catheter <NUM>, while maintaining a low torque transmission.

In this specific implementation, both of the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> have a round configuration. Alternatively, they could have a flat configuration, thereby reducing their profiles within the distal tube <NUM>.

In addition, in this implementation, as best shown in <FIG>, the distal tube <NUM> has a tapered proximal opening <NUM> and a proximal extension <NUM> that is configured to receive the manipulation shaft <NUM> as shown. In one implementation, the tapered proximal opening <NUM> provides easier access and insertion for any device being positioned through the lumen <NUM> of the distal tube <NUM>, while the proximal extension <NUM> provides enhanced strength to the connection between the manipulation shaft <NUM> and the distal tube <NUM>.

According to a further embodiment depicted in <FIG>, the device <NUM> has a manipulation shaft <NUM> that is made up of two rods <NUM>, <NUM> and a tube <NUM> positioned between the two rods <NUM>, <NUM> (as best shown in <FIG> is a side view, while <FIG> is a top view. In this implementation, the shaft <NUM> has a polymeric sheath segment <NUM> such as polyester and/or PET that is disposed around the two rods <NUM>, <NUM> and tube <NUM>. A distal portion of the shaft <NUM> is coupled to and integral with an outer wall <NUM> of the distal tube <NUM> at the connection zone <NUM>, and more specifically is coupled to a proximal extension <NUM> of the tube <NUM>. Further, the two rods <NUM>, <NUM> extend distally such that the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> extend into the distal tube <NUM>. The distal portions <NUM>, <NUM> are positioned in the wall <NUM> contralaterally in relation to each other. That is, the distal portion <NUM> is disposed in the wall <NUM> on one side of the tube <NUM> while the distal portion <NUM> is disposed in the wall <NUM> on the other side of the tube <NUM> such that the portions <NUM>, <NUM> are positioned across the lumen <NUM> from each other. Further, as best shown in <FIG>, both distal portions <NUM>, <NUM> (only <NUM> is visible in <FIG> because of the location of distal portion <NUM> behind distal portion <NUM> in the figure) have angled portions <NUM>, <NUM> that extend at an angle in relation to the longitudinal axis of the tube <NUM> and axial portions <NUM>, <NUM> that extend axially along that position for some distance as well as shown. In this specific implementation, both of the distal portions <NUM>, <NUM> of the rods <NUM>, <NUM> have a round configuration. Alternatively, they could have a flat configuration, thereby reducing their profiles within the distal tube <NUM>.

In addition, in this implementation, the tube <NUM> positioned between the two rods <NUM>, <NUM> has a proximal end of the tube <NUM> extending proximally of the distal tube <NUM> and the distal end extending into the distal tube <NUM> as shown. It is understood that the proximal end of the tube <NUM> can be positioned at any point along the length of the manipulation shaft <NUM>. Alternatively, the proximal end of the tube <NUM> can extend to the proximal end of the manipulation shaft <NUM>. According to one embodiment, the tube <NUM> has a lumen (not shown) in fluid communication with the lumen <NUM> of the sheath segment <NUM> and further in fluid communication with the lumen <NUM> of the distal tube <NUM>. Alternatively, the tube <NUM> can have a lumen (not shown) that is not in fluid communication with the lumen <NUM> or the lumen <NUM>. In yet another alternative, the tube <NUM> has no lumen. Further, in this embodiment, two marker bands <NUM> are positioned around the rods <NUM>, <NUM>.

As mentioned above, in this embodiment, the tube <NUM> extends distally into the distal tube <NUM> such that the lumen (not shown) of the tube <NUM> is in fluid communication with the lumen <NUM> of the distal tube <NUM>. Alternatively, the tube <NUM> extends distally out of the sheath <NUM> such that the distal end of the tube <NUM> is positioned in the tapered opening <NUM> of the distal tube <NUM> (described in further detail below). In that embodiment, the lumen is in fluid communication with an area external to and proximal to the lumen <NUM> of the distal tube <NUM>. In a further alternative, the tube <NUM> can extend distally to or beyond the distal end of the distal tube <NUM> such that the lumen (not shown) of the tube <NUM> is in fluid communication with an area external to and distal to the distal tube <NUM>. In a further embodiment.

In addition, in this implementation (like the embodiment depicted in <FIG>), as best shown in <FIG>, the distal tube <NUM> has a proximal extension <NUM> configured to receive the manipulation shaft <NUM> as shown and a tapered proximal opening <NUM>. The tapered proximal opening <NUM> in this embodiment has levels of tapering as shown, including a sharp tapered portion 188A, a curved tapered portion 188B, an axial portion 188C, and a second sharp tapered portion 188D. The tapered opening <NUM> provides easier access and insertion for any device being positioned through the lumen <NUM> of the distal tube <NUM>, while the proximal extension <NUM> provides enhanced strength to the connection between the manipulation shaft <NUM> and the distal tube <NUM>.

As shown in <FIG>, according to certain implementations, a manipulation shaft <NUM> can terminate in a proximal fitting <NUM>. In accordance with one embodiment, the fitting <NUM> is adapted for connection to a fluid source. In certain embodiments, the fitting <NUM> is a standard female luer connection that is made from plastic. The fitting <NUM> can be bonded to the manipulation shaft <NUM> with adhesive, or it can be insert-molded over the manipulation shaft <NUM>. In the embodiment shown in <FIG>, there is an optional strain-relief segment <NUM> disposed between the manipulation shaft <NUM> and the proximal fitting <NUM>. The strain relief segment <NUM> provides a flexible transition from the manipulation shaft <NUM> to the proximal fitting <NUM>. In this embodiment, the lumen <NUM> of the shaft <NUM> extends through the proximal fitting <NUM> as shown.

Alternatively, in <FIG>, the proximal end of the lumen <NUM> in the shaft <NUM> does not have an opening. That is, the proximal end of the lumen <NUM> is not in fluid communication with any opening at the proximal end of the shaft <NUM>.

As discussed above, certain proximal shaft implementations have a sheath defining a lumen in which two separate inner elongate members are positioned. For example, the manipulation shaft <NUM> shown in <FIG> has a sheath <NUM> defining a lumen <NUM> with two inner elongate members <NUM>, <NUM> positioned therein, wherein each of the elongate members <NUM>, <NUM> have lumens. In this embodiment, both of the elongate members <NUM>, <NUM> have reduced diameter portions 222A, 224A as shown. In this exemplary embodiment, each elongate member <NUM>, <NUM> has a connection section 222B, 224B between the full diameter section 222C, 224C and the reduced diameter section 222A, 224A that involves a narrowing or neck around the full circumference of the members <NUM>, <NUM> as shown.

Alternatively, the manipulation shaft <NUM> shown in <FIG> has sheath <NUM> defining a lumen <NUM> with two inner elongate members <NUM>, <NUM> positioned therein. The sheath <NUM> has a tapered section <NUM> in which both of the elongate members <NUM>, <NUM> have tapered sections 242B, 244B as shown. In this exemplary embodiment, each elongate member <NUM>, <NUM> has an extended taper from the full diameter section 242C, 244C to the reduced diameter section 242A, 244A.

As shown in <FIG>, certain embodiments of a distal tube <NUM> can have three segments or more of differing flexibilities: low flexibility at the proximal end <NUM> of the tube <NUM>, medium flexibility in the middle <NUM> of the tube <NUM>, and high flexibility at the distal end <NUM>. More segments of varying flexibilities can also be used. In fact, the connection zone <NUM> (the area of overlap in which the manipulation shaft <NUM> is coupled to the larger tube <NUM>) has varying flexibility in that zone <NUM>. The differing flexibilities can be accomplished through combinations of differing materials, configurations, or geometries - as is known in the art (e.g. mesh or coil reinforcing, different PEBAX varieties, etc.). Moreover, different lengths can be selected for the segments <NUM>, <NUM>, <NUM> and the connection zone <NUM> according to design considerations. This permits more flexibility along a greater length of the device <NUM> as needed to deal with anticipated curvature in the path the catheter <NUM> must follow. In another implementation, the at least three segments have differing flexibilities as follows: low flexibility at the proximal end <NUM>, high flexibility in the middle <NUM>, and low flexibility at the distal end <NUM>. Any other combination of flexibilities is also possible.

As mentioned above, the flexible tube <NUM> can have radiopaque markers embedded in the tube <NUM> and/or placed along the length of the tube <NUM> for various purposes. For example, marker <NUM> can be used at or near the distal tip <NUM> of the tube <NUM> to help the doctor locate the position of the tip <NUM>. Another marker <NUM> could be used at or near the proximal end <NUM> of the tube <NUM> to assist the doctor in locating that end <NUM> of the tube <NUM> relative to the end of the guiding catheter or to assist in visualizing the location of the proximal opening of the tube <NUM>. In one embodiment, the marker band <NUM> can be located near the proximal end <NUM> of the tube but at a position on the tube <NUM> that is distal to the end <NUM>, as shown in <FIG>.

Further, in certain embodiments, a radiopaque marker (not shown) can be located anywhere in or near the connection zone <NUM> (e.g. on the manipulation shaft <NUM> in or near the connection zone <NUM> or in the distal tube <NUM> in the connection zone <NUM>). Further, any of the markers <NUM>, <NUM>, <NUM> can be non-cylindrical. For example, one or more of the markers <NUM>, <NUM>, <NUM> can be strips or other known configurations.

One or more of these markers <NUM>, <NUM>, <NUM> can be helpful to indicate to the doctor or surgeon the location of the proximal end <NUM> of the tube <NUM> in relation to the guiding catheter (not shown) so that they do not insert or push the proximal end <NUM> past the distal end of the guiding catheter. In this regard, certain embodiments include a third marker <NUM> located at some optimal point along the tube <NUM> in between the other two markers <NUM> and <NUM>, as shown in <FIG>, <FIG>. As best shown in <FIG>, the doctor or surgeon can use this third marker <NUM> to track how far the tube <NUM> is extending beyond the guiding catheter <NUM>. That is, the third marker <NUM> can be used in certain circumstances as a limit indicator. For example, in a specific embodiment having a tube <NUM> that is <NUM> in length, the third marker band <NUM> may be located <NUM> from the distal end <NUM> of the tube <NUM> in order to indicate this predetermined distance to the doctor, such that the doctor knows the distance that the distal end <NUM> extends beyond the guide catheter <NUM>. Depending on the specific configuration of the catheter <NUM>, the third marker band <NUM> can be disposed in the low flexibility segment <NUM>, the middle flexibility segment <NUM>, or possibly even in the high flexibility segment <NUM>.

It is understood that the distal tube <NUM> can have one, two, three, or more markers as described above. It is further understood that any marker arrangement of one or more markers, including the three marker arrangement, can be used in connection with a variety of catheter configurations, including those having a solid rail (e.g. a flat or round wire) or a hollow rail or proximal section with a lumen, such as a tube. In other implementations, one or more markers can be positioned on the manipulation shaft <NUM>.

In further embodiments, the proximal shaft <NUM> can have greater longitudinal flexibility than the distal tube <NUM> or any portion thereof.

According to certain implementations, the proximal shaft <NUM> can have a lumen <NUM> that extends along the length of the proximal shaft <NUM>. As shown, the lumen <NUM> has an distal opening <NUM> that is in fluid communication with an area external to and proximal to the distal tube <NUM>. In alternative embodiments, the shaft <NUM> can extend distally into the distal tube <NUM> such that the lumen <NUM> is in fluid communication with the lumen of the distal tube <NUM> via the opening <NUM>. In a further alternative, the shaft <NUM> can extend distally through the distal tube <NUM> such that the lumen is in fluid communication with an area external to and distal to the distal tube <NUM>. In yet another alternative, the proximal shaft <NUM> has no lumen.

Other embodiments include additional support structure in the distal tube that can provide mechanical advantage similar to that provided by the support coil. <FIG> depicts a device <NUM> having a distal tube <NUM> with a support member <NUM> positioned in the connection zone <NUM> that is configured to assume at least some of the mechanical loads. Alternatively, <FIG> depicts another embodiment of a support member <NUM> positioned in the connection zone <NUM> of a distal tube <NUM>, while <FIG> shows a further implementation of a support member <NUM>. In a further alternative, the tube <NUM> can have two or more support members. In certain embodiments, the support member (including the support members <NUM>, <NUM>, <NUM> depicted in <FIG>) can be the distal portion of the rod or tube extending distally from the shaft <NUM>.

As mentioned above, certain additional embodiments as disclosed and contemplated herein relate to an improved catheter tip that can be incorporated into any known multi-layer catheter, including any catheter disclosed herein or any other catheter for use in a human patient. As will be explained in further detail below, the various catheter tip embodiments disclosed herein have a protective wrap disposed at the tip of the catheter that eliminates any exposed ends of the tubular layers.

One embodiment of catheter tube <NUM> with an improved catheter tip <NUM> is depicted in <FIG>. The tube <NUM> has a first layer (which, in this example, is also an inner layer) <NUM> and a second layer (which, in this example, is also an outer layer) <NUM>. The two layers <NUM>, <NUM> are positioned adjacent to each other and are adhered, coupled, or otherwise attached to each other along a substantial length of each. The inner layer <NUM> also has a protective wrap (also referred to as an "extended portion," "extension," "distal wrap," or "protective tip") <NUM> that extends beyond the length of the outer layer <NUM> and, in this implementation, is wrapped around the distal end of the outer layer <NUM> such that the external portion (also referred to as "outer portion" or "distal portion") of the extended portion <NUM> extends toward the proximal end of the tube <NUM> and is positioned against or adjacent to the exterior surface of the outer layer <NUM>. This configuration creates a fold <NUM> (also referred to herein as a "distal fold") of the extended portion <NUM> at the catheter tip <NUM> that facilitates protection of the tube layers at the tip <NUM>. In other words, the positioning of the extended portion <NUM> as shown ensures that the ends of the layers <NUM>, <NUM> are not exposed at the distal end of the tube <NUM>, thereby reducing the risk of delamination and the problems related thereto.

In this particular embodiment, the protective wrap <NUM> is integral with and is an extended portion of the inner layer <NUM>. Alternatively, in any of the catheter tip embodiments disclosed or contemplated herein, the protective wrap (such as protective wrap <NUM>) can be a separate component that is coupled to the distal ends of the inner layer (in this example, the inner layer <NUM>) and the outer layer (in this case, the outer layer <NUM>). In a further alternative, in any of the catheter tip embodiments disclosed or contemplated herein, the protective wrap (such as protective wrap <NUM>) can be integral with and an extended portion of the outer layer (such as outer layer <NUM>).

<FIG> shows another embodiment of a catheter tube <NUM> with an improved catheter tip <NUM>. The tube <NUM> has a first (or "inner") layer <NUM> and a second (outer) layer <NUM> that are positioned adjacent to each other and are attached to each other along a substantial length thereof. In this implementation, the protective wrap <NUM> is an extended portion <NUM> of the inner layer <NUM> that extends beyond the length of the outer layer <NUM> and, in this implementation, is folded such that the external portion or outer portion (also referred to herein as the "distal portion") 368A of the extended portion <NUM> is positioned against or adjacent to the internal portion or inner portion (also referred to herein as the "proximal portion") 368B and the distal end <NUM> of the external portion 368A is positioned against or attached to the distal end <NUM> of the outer layer <NUM>. This configuration creates a fold <NUM> (also referred to herein as a "distal fold") of the extended portion <NUM> at the catheter tip <NUM> that facilitates protection of the tube layers at the tip <NUM>. Like the embodiment depicted in <FIG>, the configuration of the protective wrap <NUM> as shown ensures that the ends of the layers <NUM>, <NUM> are not exposed at the distal end of the tube <NUM>, thereby reducing the risk of delamination and the problems related thereto.

A further implementation of a catheter tube <NUM> with an improved catheter tip <NUM> is depicted in <FIG>. The tube <NUM> has a first (inner) layer <NUM> and a second (outer) layer <NUM> that are are positioned adjacent to each other and are attached to each other along a substantial length thereof. The protective wrap <NUM> in this embodiment is an extended portion <NUM> of the inner layer <NUM> that extends beyond the length of the outer layer <NUM> and, in this implementation, is wrapped around the distal end of the outer layer <NUM> such that the external portion of the extended portion <NUM> extends toward the proximal end of the tube <NUM> and is positioned against or adjacent to the exterior surface of the outer layer <NUM>. This configuration creates a fold <NUM> (also referred to herein as a "distal fold") of the extended portion <NUM> at the catheter tip <NUM> that facilitates protection of the tube layers at the tip <NUM>. However, unlike the embodiment in <FIG>, in this implementation, the external portion of the extended portion <NUM> is positioned in a recess <NUM> or other type of configuration formed or defined in the external surface of the outer layer <NUM> such that the external portion of the extended portion <NUM> is "flush" with the outer layer <NUM>. In other words, the external portion of the extended portion <NUM> is positioned in the recess <NUM> such that the external diameter of the tube <NUM> along the length in which the external portion of the extended portion <NUM> is positioned in the recess <NUM> is the same as (or similar to) the external diameter along the length made up solely of the inner <NUM> and outer layers <NUM>.

In an alternative implementation, the recess (such as recess <NUM>) can be created by a third layer (not shown), which is an additional outer layer that is external to the outer layer <NUM> and is positioned to create the recess <NUM>. In other words, in this alternative, the layer <NUM> as shown in <FIG> is no longer an outer layer but instead is a middle layer that has no recess defined therein. Instead, the third layer is positioned over the middle layer but is shorter than the middle layer, thus leaving a portion of the middle layer exposed near the distal end, thereby creating the recess <NUM>.

In this embodiment of <FIG>, the placement or disposition of the external portion of the protective wrap <NUM> in the recess <NUM> can create a smooth (also referred to as "non-catching" or "non-snagging") outer surface of the tube <NUM> that reduces or prevents the occurrence of friction or snagging of the outer surface of the tube <NUM> within a mating (telescopic) second catheter or within a lumen or blood vessel in a patient during advancement or retraction of the tube <NUM>. In other words, the smooth outer surface means that there is no catch point formed by the protective wrap <NUM> that could potentially cause difficulties or damage in advancing or removing the device in relation to a patient.

In accordance with a further implementation, any of the improved catheter tips as discussed above with respect to <FIG> or contemplated elsewhere herein can also have variable stiffnesses along the length of the tip. For example, as shown with respect to <FIG>, in some embodiments, a distal portion <NUM> of the distal end of the tube <NUM> can be relatively stiffer than a proximal portion <NUM> of the distal end of the tube <NUM>. In certain specific implementations, the greater stiffness of the distal portion <NUM> is caused by the composition or materials of the distal portion <NUM> having a higher durometer than the composition or materials of the proximal portion <NUM>. Alternatively, the greater stiffness of the distal portion <NUM> can be accomplished in any known fashion. It is understood that the length of the tube <NUM> that is considered the distal portion <NUM> (and thus the proximal portion <NUM>) can vary, and that the specific lengths depicted in <FIG> are merely exemplary.

One of ordinary skill in the art would understand that any of the above multi-layer catheter embodiments or any other embodiments contemplated herein can have more than two layers. For example, in certain implementations, the catheter can have <NUM> layers. Alternatively, the catheter can have <NUM> layers. In further embodiments, the catheter can have <NUM> or more layers.

It is further understood that the tubes of the multi-layer catheter embodiments can be made of one or more additional known polymeric, metal, or other materials that are typically used in catheters. Further, any tube embodiment can also include one or more radioopaque markers, including the examples described in further detail below. Further, the various tube implementations can also include a metal braid or coil configuration in the tube for additional reinforcement.

As discussed above, it is also understood that the catheter tip embodiments disclosed or contemplated herein can be incorporated into any known multi-layer catheter devices. For example, in one implementation, a catheter tip embodiment could be incorporated into a guiding catheter, including, for example, the guiding catheter <NUM> depicted in <FIG> and discussed above. Alternatively, any of the catheter tip embodiments can be incorporated into any extension catheter such as those extension catheter embodiments disclosed or contemplated elsewhere herein. For example, any of the catheter tip embodiments disclosed or contemplated herein can be incorporated into the boosting catheter <NUM> as shown in <FIG> and <FIG>, the extension catheters depicted in <FIG> and <FIG>, catheters having various manipulation shaft implementations such as those depicted in <FIG>, and the boosting catheters <NUM> of <FIG>, and any other catheter embodiments disclosed or contemplated herein. In addition, the various catheter tip embodiments disclosed herein can also be integrated into or combined with any known catheter. Further, it is understood that any of the improved catheter tip embodiments disclosed or contemplated herein can be integrated into or combined into a distal tip, including the distal end of any distal tube, of any of the various catheter implementations, such as guiding catheters, sheaths, delivery catheters (including stent delivery systems), snares, and arthorectomy catheters.

Further, it is understood that any of the various improved catheter tip embodiments disclosed or contemplated herein can be integrated into or combined with any boosting catheter, including the boosting catheter disclosed and claimed in <CIT>, entitled "Boosting Catheter and Related Systems and Methods".

In addition, any of the various catheter embodiments disclosed herein, including the various implementations having a segmented catheter structure and the various implementations having an improved catheter tip can have an external lubricious coating. The external lubricious coating can be positioned around or integral with an entire length of the distal tube (or any portion thereof), an entire length of the proximal shaft (or any portion thereof), or an entire length of both the distal tube and the proximal shaft (or any portions thereof). In some implementations, the lubricious coating can be hydrophobic, while in other embodiments it can be hydrophilic.

Further, any of the various catheter embodiments disclosed herein, including the various implementations having a discontinuous or segmented catheter structure and the various implementations having an improved catheter tip, also have an outer support membrane (also referred to as a "support membrane" or "support layer") disposed around a proximal portion of the distal tube. It is also understood that any embodiment of the support membrane as disclosed or contemplated herein can also be incorporated into any other known catheter. <FIG> depicts one embodiment of a catheter <NUM> in which the distal tube <NUM> has a support membrane <NUM> disposed around and coupled to the external wall <NUM> of the distal tube <NUM>. More specifically, in this exemplary embodiment, the membrane <NUM> is disposed around a portion of the wall <NUM> and extends longitudinally along the length of the tube <NUM> such that the proximal end of the membrane <NUM> does not extend to the proximal end <NUM> of the tube <NUM>. That is, the membrane <NUM> is positioned such that it is spaced from the proximal end <NUM> of the tube <NUM>. Alternatively, the membrane <NUM> can extend to the proximal end <NUM> of the tube <NUM>. According to certain implementations, the membrane <NUM> is disposed in the connection zone (or region) of the distal tube <NUM> in which the manipulation shaft <NUM> is coupled to the tube <NUM> (similar to the connection zone <NUM> discussed above with respect to <FIG>).

The membrane <NUM> (and any other membrane embodiment disclosed or contemplated herein) wraps or is otherwise disposed around a portion of the circumference of the tube <NUM> as shown. Alternatively, outside the scope of the claims, the membrane can be an additional tube or tube layer that is disposed around the entire circumference of the tube <NUM>. In a further alternative, the membrane can be disposed around <NUM>/<NUM>, <NUM>/<NUM>, or <NUM>/<NUM> of the circumference of the tube <NUM>. In yet another alternative, as best shown in <FIG>, the membrane <NUM> can be disposed around any amount of the circumference of the tube <NUM>, with the membrane <NUM> being disposed around the entire circumference of the tube <NUM> being outside the scope of the claims. That is, the membrane <NUM> can cover any amount of the circumference of the tube <NUM> from about <NUM> degrees to about <NUM> degrees of the circumference, with the membrane <NUM> covering <NUM> degrees of the circumference being outside the scope of the claims. It is understood that these characteristics can apply to any membrane embodiment disclosed or contemplated herein that is disposed around any tube, including any catheter tube.

The membrane <NUM> (and any other membrane embodiment disclosed or contemplated herein) can have any size, shape, or configuration. In certain implementations, the membrane can be circular, oval, or an ellipse. Further, any of the membrane embodiments disclosed or contemplated herein is not necessarily a unitary, uniform component. Instead, any membrane embodiment can have one or more openings defined therein. In certain implementations, the one or more openings can be one or more channels defined in the membrane. Alternatively, membrane can have any pattern, feature, or configuration that forms any shape or shapes.

The various membrane embodiments disclosed herein (including membrane <NUM>) can be made of any polymeric or non-polymeric material or any other known material that can be positioned around a catheter tube and is high strength and/or puncture resistant. For example, in one embodiment in which the material is polymeric, the material can be PTFE (etched or non-etched), PET, or PEEK or any other known polymeric material with the appropriate high strength and/or puncture resistance characteristics. In one embodiment, the membrane (such as membrane <NUM>) has a thickness ranging from about <NUM> inches (<NUM> millimetres) to about <NUM> inches (<NUM> millimetres). Alternatively, the membrane can have a thickness ranging from about <NUM> inches (<NUM> millimetres) to about <NUM> inches (<NUM> millimtres).

The membrane <NUM> (or any other membrane implementation disclosed or contemplated herein) can be attached to the external wall (such as wall <NUM>) of the tube (such as tube <NUM>) in a reflow process (in which the tube materials are heated/melted and the membrane is heat bonded to the tube), via adhesive bonding, or any other known method of attachment.

<FIG> shows another embodiment of a catheter <NUM> with a membrane <NUM> disposed around the connection zone of the manipulation shaft <NUM> and the distal tube <NUM>. In this embodiment, the membrane <NUM> covers more of the circumference of the tube <NUM> in comparison to the membrane <NUM> discussed above and depicted in <FIG>. Further, in this implementation, the membrane <NUM> extends longitudinally along the length of the tube <NUM> such that the proximal end of the membrane <NUM> extends to the proximal end <NUM> of the tube <NUM>. That is, the proximal end of the membrane <NUM> is positioned at the proximal end <NUM> of the tube <NUM>. Alternatively, the membrane <NUM> can be spaced from the proximal end <NUM> of the tube <NUM>.

A side view of another embodiment is shown in <FIG> in which the membrane <NUM> is positioned around the connection zone of the manipulation shaft <NUM> and the distal tube <NUM> of the catheter <NUM>.

As mentioned above, any embodiment of the support membrane can also be incorporated into any other known catheter. For example, in another implementation as depicted in <FIG>, the membrane <NUM> is positioned around the connection zone of the manipulation shaft <NUM> and the distal tube <NUM> of the catheter <NUM>. In this embodiment, the manipulation shaft <NUM> is a flat or substantially square shaft or wire <NUM>. Alternatively, the shaft <NUM> can have any known cross-sectional shape for a known component of a catheter. In further implementations, the shaft <NUM> can be tapered along some portion of its length or the entire length thereof.

In a further embodiment as shown in <FIG>, the membrane <NUM> can be positioned around another known catheter. In this implementation, the catheter <NUM> has a manipulation shaft <NUM> that can be a solid wire or hollow tube that is further joined to a cylindrical or partially-cylindrical structure <NUM>. The structure <NUM> is embedded within, or joined to, the wall at the proximal end of the distal tube <NUM>. In certain embodiments, the structure <NUM> can be slotted or have a pattern formed therein to enhance attachment and flexibility. The support membrane <NUM> is positioned around the circumference or a portion of the circumference of the distal tube <NUM> in the connection zone extending distally on the distal tube from the structure <NUM>, with the support membrane <NUM> being positioned around the entire circumference of the distal tube <NUM> being outside the scope of the claims. In certain embodiments, the support membrane <NUM> can enhance or strengthen the attachment of the structure <NUM> and the distal tube <NUM>.

In yet another implementation as shown in <FIG>, the membrane <NUM> can be positioned around another known catheter. That is, the membrane <NUM> is positioned around the connection zone of the manipulation shaft <NUM> and the distal tube <NUM> of the catheter <NUM>. In this embodiment, the manipulation shaft <NUM> has an extension <NUM> that extends into and is embedded within the proximal end of the distal tube <NUM> as shown. The extension <NUM> in this embodiment has a configuration or features that strengthen the connection between the manipulation shaft <NUM> and the tube <NUM>, thereby reducing the risk of separation of those two components.

Without being limited by theory, it is believed that the membrane embodiments disclosed herein provide a higher strength bond for the proximal portion of the distal tube that the membrane is disposed around, along with enhanced torque, peel, and shear strength. In those implementations in which the membrane disposed around the proximal portion is disposed around the connection zone of the catheter, the added strength bond can increase tensile strength and help prevent or reduce the risk of delamination, thereby preventing or reducing the risk of separation of the proximal manipulation shaft from the distal tube. That is, the membrane can provide fatigue resistance at the connection zone. In known fatigue testing of known catheters, application of repeated stress to the connection zone of the catheters caused the proximal shaft to separate from the distal tube (which could result in detachment proximal shaft from the distal tube or embolization during use). The membrane embodiments disclosed herein can reduce or prevent the risk of such separation. In addition, the membrane embodiments can also provide enhanced lubricity and additional strain relief properties.

The membrane is disposed around a portion of the circumference of the tube, rather than the entire circumference. Any membrane disposed around less than the entire circumference can be called a "partial circumference membrane. " One advantage of a partial circumference membrane made of a high strength material such as those discussed above is that it provides support without fully encircling the tube. It is understood that a membrane made of a high strength material (such as PTFE or PEEK) that fully encircles the catheter tube could cause the catheter tube to malfunction or not function properly. That is, the high strength material positioned entirely around the tube could render that portion of the tube too inflexible or otherwise inoperable for its desired purpose. Thus, in those circumstances, a partial circumference membrane can utilize a high strength material while not rendering the catheter tube hindered or inoperable.

Further, a partial circumference membrane can also have the advantage of providing the thinnest thickness (or lowest profile) possible when adding an additional layer to a tube. That is, a membrane that encircles the entire circumference of a tube will add more outer diameter to the tube than a partial circumference membrane. As such, any partial circumference membrane can minimize the additional circumference of a tube when the membrane is added thereto.

Certain additional embodiments as disclosed and contemplated herein relate to an improved proximal portion of a catheter tube that can be incorporated into any known multi-layer catheter, including any catheter disclosed herein or any other catheter for use in a human patient. As will be explained in further detail below, the various improved proximal tube portion embodiments disclosed herein have a protective wrap disposed at the proximal portion of the tube that eliminates any exposed ends of the tubular layers. It is understood that the improved proximal tube portion embodiments are substantially similar to the improved catheter tip embodiments discussed above.

One embodiment of catheter tube <NUM> with an improved proximal portion <NUM> is depicted in <FIG>. The tube <NUM> has a first layer (which, in this example, is also an inner layer) <NUM> and a second layer (which, in this example, is also an outer layer) <NUM>. The two layers <NUM>, <NUM> are positioned adjacent to each other and are adhered, coupled, or otherwise attached to each other along a substantial length of each. At least a portion of the inner layer <NUM> is a protective wrap (also referred to as an "extended portion," "extension," "distal wrap," or "protective tip") <NUM> that extends beyond the length of the outer layer <NUM> and, in this implementation, is wrapped around at least a portion of the distal end of the outer layer <NUM> as shown such that the external portion (also referred to as "outer portion" or "distal portion") of the extended portion <NUM> extends toward the distal end of the tube <NUM> and is positioned against or adjacent to the exterior surface of the outer layer <NUM>. This configuration creates a fold <NUM> (also referred to herein as a "distal fold") of the extended portion <NUM> along at least a portion of the proximal end <NUM> of the tube <NUM> that facilitates protection of the tube layers at the end <NUM>. In other words, the positioning of the extended portion <NUM> as shown ensures that the ends of the layers <NUM>, <NUM> are not exposed along that portion of the proximal end <NUM> of the tube <NUM> covered by the wrap <NUM>, thereby reducing the risk of delamination and the problems related thereto.

In this particular embodiment, the protective wrap <NUM> is integral with and is an extended portion of the inner layer <NUM>. Alternatively, in any of the improved proximal tube portion embodiments disclosed or contemplated herein, the protective wrap (such as protective wrap <NUM>) can be a separate component that is coupled to at least a portion of the distal ends of the inner layer (in this example, the inner layer <NUM>) and the outer layer (in this case, the outer layer <NUM>). In a further alternative, in any of the proximal tube portion embodiments disclosed or contemplated herein, the protective wrap (such as protective wrap <NUM>) can be integral with and an extended portion of the outer layer (such as outer layer <NUM>).

<FIG> shows another embodiment of a catheter tube <NUM> with an improved proximal tube portion <NUM>. The tube <NUM> has a first (or "inner") layer <NUM> and a second (outer) layer <NUM> that are positioned adjacent to each other and are attached to each other along a substantial length thereof. In this implementation, the protective wrap <NUM> is an extended portion <NUM> of the inner layer <NUM> that extends beyond the length of the outer layer <NUM> and, in this implementation, is folded such that the external portion or outer portion (also referred to herein as the "distal portion") 528A of the extended portion <NUM> is positioned against or adjacent to the internal portion or inner portion (also referred to herein as the "proximal portion") 528B along at least a portion of the circumference of the end <NUM> and the distal end <NUM> of the external portion 528A is positioned against or attached to the proximal end <NUM> of the outer layer <NUM>. This configuration creates a fold <NUM> (also referred to herein as a "distal fold") of the extended portion <NUM> at the proximal end <NUM> along at least a portion of the end <NUM> that facilitates protection of the tube layers at the end <NUM>. Like the embodiment depicted in <FIG>, the configuration of the protective wrap <NUM> as shown ensures that at least a portion of the ends of the layers <NUM>, <NUM> are not exposed at the proximal end <NUM> of the tube <NUM>, thereby reducing the risk of delamination and the problems related thereto.

Additional implementations similar to those discussed above with respect to <FIG> and any other embodiments contemplated in the discussion above are also contemplated for the proximal tube end improvements. That is, any features or configurations of the improved distal tip embodiments discussed above and depicted in <FIG> can also be incorporated into any of the embodiments of the improved proximal portions as discussed above and depicted in <FIG>. However, in certain embodiments of the improved proximal portion as noted above, the protective wrap does not extend around the entire circumference of the proximal end of the tube. As discussed above, it is also understood that the improved proximal end embodiments disclosed or contemplated herein can be incorporated into any known multi-layer catheter devices. Further, it is understood that any of the various improved proximal end embodiments disclosed or contemplated herein can be integrated into or combined with any boosting catheter, including the boosting catheter disclosed and claimed in U. Application <NUM>/<NUM>,<NUM>, entitled "Boosting Catheter and Related Systems and Methods".

Claim 1:
A catheter (<NUM>) comprising:
(a) a distal tube (<NUM>) comprising a tubular wall (<NUM>) and a tube lumen (<NUM>) defined within the tube (<NUM>) by the tubular wall (<NUM>);
(b) a support membrane (<NUM>) disposed around and coupled to a portion of an external wall (<NUM>) of the distal tube (<NUM>), wherein a proximal end of the support membrane (<NUM>) extends at most to the proximal end (<NUM>) of the distal tube (<NUM>), wherein the support membrane (<NUM>) is a partial circumference membrane; and
(c) a proximal shaft (<NUM>) operably coupled to a proximal portion of the distal tube (<NUM>), the proximal shaft (<NUM>) comprising:
(i) a first elongate member (<NUM>);
(ii) a second elongate member (<NUM>); and
(iii) a first sheath segment (<NUM>) disposed around a first length of the first and second elongate members (<NUM>, <NUM>) such that the first length of the first and second elongate members (<NUM>, <NUM>) is disposed within the first sheath segment (<NUM>),
wherein the first and second elongate members (<NUM>, <NUM>) are configured to extend distally into a portion of the distal tube (<NUM>).