WO2025227008A1

WO2025227008A1 - Steerable catheter shaft

Info

Publication number: WO2025227008A1
Application number: PCT/US2025/026325
Authority: WO
Inventors: Michael C. MURAD; Michael R. Bialas
Original assignee: Edwards Lifesciences Corp
Current assignee: Edwards Lifesciences Corp
Priority date: 2024-04-26
Filing date: 2025-04-25
Publication date: 2025-10-30
Anticipated expiration: 2026-10-26

Abstract

A catheter device (10, 100, 200) can include a shaft (14, 102) comprising a proximal portion (16, 115), a steerable distal portion (116), one or more layers forming a wall, and one or more pull wire tubes (108, 112, 114, 206) disposed in the wall. The pull wire tubes can be disposed at a first circumferential location of the shaft in the proximal portion of the shaft. The shaft can further comprise a splitter member (202, 300) disposed within the wall of the shaft, the splitter member defining a divergence point where the one or more pull wire tubes diverge from the first circumferential location to a second circumferential location in the steerable distal portion of the shaft, the second circumferential location being circumferentially offset from the first circumferential location.

Description

STEERABLE CATHETER SHAFT

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application 63/639,173 filed April 26, 2024. The prior application is incorporated herein by reference in its entirety.

FIELD

[0002] The present disclosure relates to steerable catheter shafts, and to methods and assemblies for making steerable catheter shafts.

BACKGROUND

[0003] The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (for example, stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. Percutaneous and minimally-invasive surgical approaches are used in various procedures to deliver prosthetic medical devices to locations inside the body that are not readily accessible by surgery or where access without surgery is desirable. In one specific example, a prosthetic heart valve can be mounted in a crimped state on the distal end of a delivery apparatus and advanced through the patient’s vasculature (for example, through a femoral artery and the aorta) until the prosthetic heart valve reaches the implantation site in the heart. The prosthetic heart valve is then expanded to its functional size, for example, by inflating a balloon on which the prosthetic valve is mounted, actuating a mechanical actuator that applies an expansion force to the prosthetic heart valve, or by deploying the prosthetic heart valve from a sheath of the delivery apparatus so that the prosthetic heart valve can self-expand to its functional size.

[0004] The usefulness of delivery devices is largely limited by the ability of the device to successfully navigate through small vessels and around tight bends in the vasculature, such as around the aortic arch. Various techniques have been employed to adjust the curvature of a section of a delivery device to help “steer” the prosthetic valve through bends in the vasculature. Typically, a delivery device employs a pull wire having a distal end fixedly secured to the steerable section and a proximal end operatively connected to an adjustment knob located on a handle of the delivery device outside the body. The pull wire is typically disposed in a pull-wire lumen (or tube) that extends longitudinally in or adjacent to a wall of the delivery device, for example, a sheath or catheter. Adjusting the adjustment knob, for example, rotating the knob, applies a pulling force on the pull wire, which in turn causes the steerable section to bend. Nevertheless, there is a continued need for improved delivery devices.

SUMMARY

[0005] Described herein are examples of delivery devices and catheter shafts for prosthetic implants and methods and assemblies for making the aforementioned. The disclosed catheter shafts can, for example, comprise a diverging pull wire path that allows a single wire to create bending in multiple planes of direction in a three-dimensional (3D) space, so as to accurately and conveniently position and align the distal end (and the atraumatic tip) of the catheter shaft. As such, the devices and methods disclosed herein can, among other things, overcome one or more of the deficiencies of typical delivery apparatus.

[0006] A delivery apparatus for a prosthetic implant can comprise a handle and one or more catheter shafts coupled to the handle. A catheter shaft can comprise a proximal portion and a steerable distal portion.

[0007] In some examples, the catheter shaft can comprise one or more pull wire tubes disposed at a first circumferential location in the proximal portion of the shaft and a second circumferential location in the steerable distal portion. The second circumferential location can be circumferentially offset from the first circumferential location.

[0008] In some examples, the catheter shaft can comprise a splitter member disposed within a wall of the shaft, the splitter member defining a divergence point wherein the one or more pull wires tubes diverge from the first circumferential location to the second circumferential location.

[0009] In some examples, the splitter member can include a proximal end portion comprising first and second projections defining a channel between them and the one or more pull wires are disposed within the channel. In some examples, the splitter member can include a distal end portion having one or more lateral projections configured to retain the one or more pull wire tubes at the second circumferential location. [0010] In some examples, the splitter member comprises first and second annular members, the first annular member having a proximal end portion configured to retain the one or more pull wire tubes at the first circumferential location and the second annular member having a distal end portion configured to retain the one or more pull wire tubes at the second circumferential location.

[0011] In some examples, the catheter shaft can comprise a first coil layer extending a first length along substantially the full length of the shaft and a second coil layer extending less than the first length. The one or more pull wire tubes can be disposed between the first and second coil layers such that they are adjacent one another in a first configuration at a proximal end of the second coil layer and diverge from one another to assume a second configuration wherein they are disposed at a selected angular offset from one another.

[0012] In some examples, a catheter shaft can be made using a mandrel comprising a first member and a second member coupled to the first member. The mandrel can comprise one or more channels disposed on an outer surface of the first and second members, the one or more channels extending in a first configuration along a length of the first member until a divergence point and diverging around a circumference of the mandrel to assume a second configuration extending along a length of the second member.

[0013] In some examples, a catheter device can be formed using the following method. Disposing a first layer on a mandrel, positioning a pull wire tube on the first layer such that a proximal end portion of the pull wire tube is disposed in a first circumferential location at the proximal end portion of the mandrel and diverges at a selected divergence point to a second circumferential location circumferentially offset from the first circumferential location, disposing a flexible polymer layer over the pull wire tube, and reflowing the flexible polymer layer and fist layer to form a catheter shaft.

[0014] In some examples, a delivery apparatus can comprise a catheter shaft comprising one or more of the features recited in Examples 1-17 below. In some examples, a catheter device can be formed using any of the devices or methods recited in Examples 18-27 below.

[0015] The various innovations of this disclosure can be used in combination or separately. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the disclosure will become more apparent from the following detailed description, claims, and accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 shows a perspective view of a representative delivery apparatus, according to one example.

[0017] FIG. 2 shows a cross-sectional side elevation view of a distal portion of the delivery apparatus depicted in FIG. 1.

[0018] FIG. 3 shows a cross-sectional view of the delivery apparatus depicted in FIG. 1, taken along line 3-3 of FIG. 2, according to one example.

[0019] FIG. 4 is a schematic side view of a distal end portion of a catheter device, according to one example, having two pull wires which extend through a central proximal lumen and two distal lumens.

[0020] FIG. 5 is a cross-sectional view of the catheter device of FIG. 4, taken along line 7-7 of FIG. 4.

[0021] FIG. 6 is a perspective view of the catheter device of FIG. 4, showing the ability of the distal tip portion to flex at various angles within a range of flexion (a) of the distal tip portion.

[0022] FIG. 7 is a perspective view of an assembly for forming a catheter shaft including a mandrel and a splitter member, according to one example.

[0023] FIG. 8 is a perspective view of the splitter member of FIG. 7.

[0024] FIG. 9 is a perspective view of a splitter member according to another example.

[0025] FIG. 10 is a perspective view of a ring member according to one example.

[0026] FIG 11 is a perspective view of a catheter shaft according to one example.

[0027] FIG. 12 a perspective view of the catheter shaft of FIG. 11 including an exemplary splitter member. [0028] FIG. 13 is a perspective view of a mandrel for forming a catheter shaft, according to one example.

DETAILED DESCRIPTION

General Considerations

[0029] For purposes of this description, certain aspects, advantages, and novel features of examples of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed examples, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed examples require that any one or more specific advantages be present or problems be solved.

[0030] Although the operations of some of the disclosed examples are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. Additionally, the description sometimes uses terms like “provide’" or “achieve’" to describe the disclosed methods. These terms are high-level abstractions of the actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by one of ordinary skill in the art.

[0031] As used in this application and in the claims, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the term “includes” means “comprises.” Further, the term “coupled” generally means physically, mechanically, chemically, magnetically, and/or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language. [0032] Unless otherwise indicated, all numbers expressing material quantities, angles, pressures, molecular weights, percentages, temperatures, times, and so forth, as used in the specification or claims are to be understood as being modified by the term “about.” Accordingly, unless otherwise indicated, implicitly or explicitly, the numerical parameters set forth are approximations that can depend on the desired properties sought and/or limits of detection under test conditions/methods familiar to those of ordinary skill in the art. When directly and explicitly distinguishing embodiments from discussed prior art, the embodiment numbers are not approximates unless the word “about” is recited. Furthermore, not all alternatives recited herein are equivalents.

[0033] As used herein, the term “proximal” refers to a position, direction, or portion of a device that is closer to the user and further away from the implantation site. As used herein, the term “distal” refers to a position, direction, or portion of a device that is further away from the user and closer to the implantation site. Thus, for example, proximal motion of a device is motion of the device away from the implantation site and toward the user (for example, out of the patient’s body), while distal motion of the device is motion of the device away from the user and toward the implantation site (for example, into the patient’s body). The terms “longitudinal” and “axial” refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

[0034] As used herein, “e.g.” means “for example,” and “i.e.” means “that is.”

Examples of the Disclosed Technology

[0035] A steerable medical apparatus that can be used to deliver a medical device, tools, agents, or other therapy to a location within the body of a subject can include one or more steerable catheters and/or sheaths. Examples of procedures in which steerable catheters and sheaths are useful include cardiovascular, neurological, urological, gynecological, fertility (e.g., in vitro fertilization, artificial insemination), laparoscopic, arthroscopic, transesophageal, transvaginal, transvesical, transrectal, and procedures including access in any body duct or cavity. Particular examples include placing implants, including stents, grafts, embolic coils, and the like; positioning imaging devices and/or components thereof, including ultrasound transducers; and positioning energy sources, for example, for performing lithotripsy, RF sources, ultrasound emitters, electromagnetic sources, laser sources, thermal sources, and the like. In particular examples, the steerable medical apparatus is a delivery apparatus that is configured to deliver an implantable medical device, such as a prosthetic heart valve, through a patient’s vasculature to the heart of a patient. Thus, the following description proceeds with reference to a steerable delivery apparatus. However, it should be understood that the examples disclosed herein can be incorporated in any steerable medical apparatus that is insertable into a patient’s body for performing a medical procedure on the patient.

[0036] In some examples, the delivery apparatus includes a steerable shaft such as a guide sheath having one or more delivery catheters coaxially disposed within the guide sheath. In certain configurations, the delivery catheters can comprise one or more balloons or another type of expansion device at or near a distal end portion thereof for expanding an implantable medical device, such as a prosthetic heart valve.

[0037] Typically, a delivery device employs a pull wire having a distal end fixedly secured to a steerable section and a proximal end operatively connected to an adjustment knob located on a handle of the delivery device outside the body. The pull wire is typically disposed in a pull- wire lumen (also referred to as a pull wire tube) that extends longitudinally in or adjacent to a wall of the delivery device, for example, a sheath or catheter. Adjusting the adjustment knob, for example, rotating the knob, applies a pulling force on the pull wire, which in turn causes the steerable section to bend.

[0038] Some delivery devices employ multiple pull wires in order to enable curving the steerable section in multi-dimensions. For example, some delivery devices have two pull wires, each of which has a distal end fixedly coupled to the steerable section, and the distal end of the two pull wires are spaced apart from one another about the circumference of the shaft. The proximal end of each pull wire can be operatively connected to a respective adjustment knob on the handle to adjust the pull wire’s tension. As such, tensioning both pull wires can flex the steerable section in a first plane (e.g., curving backward toward the handle), whereas increasing tension in one of the pull wires while releasing tension in the other pull wire can flex the steerable section in a second plane (e.g., curving sideway) that transverses the first plane.

[0039] The wire paths of such catheters are typically straight along the length of the catheter and the ability to steer the catheter in multiple directions is dependent upon the number of pull wires and the angle between them (i.e., their position about the circumference of the catheter shaft). Such catheters are typically formed using a traditional grooved mandrel that holds the pull wires in place during manufacturing. However, use of a traditional grooved mandrel prevents any single pull wire from being able to change direction/orientation along the length of the shaft.

[0040] FIG. 1 illustrates an exemplary delivery apparatus 10 comprising a handle 12 and a shaft 14 extending distally therefrom. The shaft 14 has a proximal portion 16 adjacent the handle and a distal portion 18. The proximal portion 16 of the shaft 14 can be coupled to the handle 12. The handle 12 can be configured to position and/or manipulate the shaft 14, as further described below.

[0041] Although not shown, the delivery apparatus 10 can include one or more catheters coaxially disposed within and/or surrounding and movable relative to the shaft 14. For example, the delivery apparatus 10 can include an outer sheath extending over and longitudinally movable relative to the shaft 14. The delivery apparatus can also have an inner catheter configured as an implant catheter coaxially disposed within and movable relative to the central lumen 30 of the shaft 14, and the implant catheter can have a balloon- inflatable or self-expandable prosthetic heart valve mounted on a distal end of the implant catheter. Exemplary configurations of the prosthetic heart valve and implant catheter are further disclosed in U.S. Patent Nos. 7,780,723, 7,993,394, 8,077,955, 8,568,472, 8,652,202, 9061,119, 9,339,384, and 9,393,110, the disclosures of which are incorporated by reference. In addition, it should be understood that the delivery apparatus 10 can be used to deliver any of various other implantable devices, such as docking devices, leaflet clips, etc.

[0042] Referring to FIG. 2, the shaft 14 can have a central lumen 30 enclosed by a side wall 32. The side wall 32 of the shaft 14 can, in some examples, be made of a flexible, axially- non-compressible material and/or structure. In some examples, the shaft 14 can be an extruded polymer tube that is extruded to form the central lumen and the side wall 32. In another example, the side wall 32 can comprise a helical coil, which desirably is a closed pitch coil without spacing between adjacent turns of the coil to avoid axial compression of the coil. The coil can be made of any suitable biocompatible metal, polymer, or combination thereof. The shaft can include an inner polymer layer extending over the inner surface of the coil and/or an outer polymer layer extending over the outer surface of the coil. [0043] In alternative examples, the side wall 32 can comprise an elongated slotted tube (e.g., a metal tube) that has a plurality of axially-spaced, circumferentially extending slots formed (such as by laser cutting) along the length of the tube. Exemplary configurations of the slotted tube are described in U.S. Patent No. 9,907,651, which is incorporated herein by reference.

[0044] In another example, the side wall 32 can comprise a polymeric tube reinforced with a braided metal layer, such as polyimide tube reinforced with a braided stainless steel layer. In some examples, an inner polymeric layer (also referred to as a “liner layer”) can be secured to the inner surface of the braided layer and/or an outer polymeric layer can be secured to the outer surface of the braided layer.

[0045] As shown in FIGS. 2 and 3 the shaft 14 can further comprise a plurality of pull wires 20, 22 disposed in and extending longitudinally through respective pull-wire conduits 24, 26 formed in the side wall 32. The pull wires 20, 22 can be used to control and/or manipulate the curvature of the distal portion 18 of the shaft 14. The pull-wire conduits 24, 26 can extend at least partially through the proximal portion 16 and distal portion 18 of the shaft 14.

[0046] In some examples, the central lumen 30 and/or the pull-wire conduits 24, 26 can have a low-friction and/or flexible liner (not shown) covering the inner surface of the lumen/conduit, and the liner can comprise polytetrafluoroethylene (PTFE), ultra-high- molecular-weight polyethylene (UHMWPE), or another suitable material.

[0047] A proximal end of the first pull wire 20 and a proximal end of the second pull wire 22 can be connected to a steering mechanism of the handle 12. The steering mechanism can be configured to selectively increase and/or decrease tension in the pull wires 20, 22 to, for example, adjust the curvature of the distal portion 18 of the shaft 14 (see e.g., FIG. 1 which illustrates the curvature of the distal portion 18 in phantom).

[0048] In some examples, the distal portion 18 of the shaft 14 can be constructed from a relatively more flexible material than the proximal portion 16 of the shaft 14 and/or can otherwise be constructed to be relatively more flexible than the proximal portion 16 of the shaft 14 such that the curvature of the proximal portion 16 can remain substantially unchanged when the curvature of the distal portion 18 is adjusted by applying tension thereto by the pull wires 20, 22, as further described below. Further details of the construction of the shaft 14, the handle 12, and/or adjusting tension in a pull wire are described in U.S. Patent Nos. 9,339,384, 9,061,119, 8,568,472, and 7,780,723, which are incorporated by reference herein.

[0049] Referring to FIG. 2, the distal end 28 of the shaft 14 can be formed as a low durometer atraumatic tip, which can, in certain examples, be radiopaque. A distal end 20b of the first pull wire 20 and a distal end 22b of the second pull wire 22 can be coupled to the distal portion 18 of the shaft 14. In certain examples, the distal end 20b of the first pull wire 20 and the distal end 22b of the second pull wire 22 can be coupled to the same or at least substantially the same axially location at the distal end 28 of the shaft 14. For example, in some examples, the distal ends 20b, 22b of the pull wires 20, 22 can be fixedly secured to a pull ring 34 that is proximally adjacent to the distal end 28 of the shaft 14. The pull ring 34, which can be coaxial with the distal portion 18 of the shaft 14, can be embedded or otherwise secured to the shaft 14 at or adjacent to the distal ends of the pull-wire conduits 24, 26.

[0050] As shown in FIG. 3, the pull- wire conduits 24, 26 can be eccentrically disposed relative to the central lumen 30 and circumferentially spaced relative to each other at the distal portion 18 of the shaft 14. As shown, the pull wire conduits 24, 26 can be spaced apart from one another by an angle (a) between axes Bi and B2. In some examples, the angle a can be any angle greater than zero degrees and less than 180 degrees. In some examples, the angle a can be between 90 degrees and 150 degrees. In the example shown, the angle a is 120 degrees. In some examples, the angle a can be 180 degrees (i.e., the distal ends of the pull wires 20, 22 are diametrically opposed to one another with respect to the central axis 36). Tensioning both wires 20, 22 can cause the distal portion 18 of the shaft 14 to curve in a first plane P.

[0051] In some examples, the pull-wire conduits 24, 26 are spatially separated from each other along the entire length of the shaft 14. Alternatively, the pull-wire conduits 24, 26 can be merged together at the proximal portion 16 of the shaft 14 (such that the pull wires 20, 22 are adjacent one another at the proximal portion) but branch out separately at the distal portion 18 of the shaft 14. In other words, the pull wires 20, 22 can share the same lumen along the proximal portion 16 of the shaft 14 but extend through separate, longitudinally extending pull-wire conduits 24, 26 at the distal portion 18 of the shaft 14. Other configurations of pull-wire conduits and pull-wire configurations can be found, for example, in U.S. Patent No. 11,207,499 and U.S. Publication No. 2022/0096229, both of which are incorporated by reference herein in their entireties.

[0052] The examples herein describe methods for assembly of a steerable catheter including a diverging pull wire path wherein the pull wires are positioned in a first configuration (e.g., adjacent one another) along a first portion of the shaft (e.g., the proximal end portion and much of the main body) and then change direction/orientation such that they are in a second configuration (e.g., separate from one another about a circumference of the shaft) along a second portion of the shaft (e.g., the distal end portion). This allows a single wire to create bending in multiple planes of direction in a three-dimensional (3D) space, so as to accurately and conveniently position and align the distal end (and the atraumatic tip) of the catheter shaft.

[0053] Traditional methods of including multiple pull wires angularly spaced from one another about the circumference of a catheter shaft require a groove defined in a mandrel to hold the pull wire (or a spacer mandrel) during manufacture of the catheter. However, if it is desired that the pull wire curve from one angular location to another, locating the pull wire in a correspondingly curved groove in the mandrel may cause the pull wire to lock the catheter to the mandrel, complicating removal of the mandrel from the catheter. The structures and methods described herein reduce the likelihood or eliminate this problem and allow the pull wires to change direction at a selected location.

[0054] With reference to FIGS. 4-6, the methods described herein can result in a catheter 100 that has one or more pull wires (e.g., first and second pull wires 104, 106), and a shaft 102 having a proximal portion 115 (FIG. 6) and a steerable distal portion 116. The distal portion 116 can be relatively more flexible than the proximal portion 115. The proximal portion 115 can be coupled to a handle (not shown) that can have one or more adjustment mechanisms for increasing and decreasing tension in the pull wires 104, 106. In particular examples, the catheter device 100 has two adjustment mechanisms, each of which is connected to a respective pull wire 104, 106.

[0055] The main body 110 can further comprise a main pull- wire lumen 108 extending parallel to a central axis X of the shaft through the proximal portion 115 and through a proximal section 118 of the distal portion 116. The main pull-wire lumen 108 can then split into a first distal pull-wire lumen 112 and a second distal pull-wire lumen 114 that diverge away from each other and then extend generally parallel to each other at angularly spaced locations through a distal section 120 of the distal portion 116 of shaft. The pull wires 104, 106 can thus extend through the main pull- wire lumen 108 over the proximal portion 115 and the proximal section 118 of the distal portion 116 of the shaft. The first and second pull wires 104, 106 then part ways to extend into the first distal pull-wire lumen 112 and the second distal pull-wire lumen 114, respectively, over the distal section 120 of the distal portion 116. [0056] In other examples, rather than a common pull-wire lumen 108, the catheter can comprise separate longitudinally extending pull-wire lumens that are parallel and in close proximity to each other or without any spacing between each other along the length of the proximal portion 115 and the proximal section 118 of the distal portion, and then diverge away from each other and extend along the distal section 120 with a spacing a between the two pull- wire lumens.

[0057] FIG. 5 shows the angular positioning of the two distal pull-wire lumens 112, 114 (and thus the pull wires 104, 106) along an arc defined by the side wall of the shaft 102. In the illustrated example, the two distal pull-wire lumens 112, 114 are disposed within the side wall of the shaft 102. In other examples, the distal pull-wire lumens 112, 114 have a different location, for example, adjacent to an interior of the side wall or adjacent to an exterior of the side wall. The first pull- wire lumen 112 can be positioned along a first axis B 1 extending radially from the central axis X of the shaft 102 to the first lumen 112. The second pull wire lumen 114 can be positioned along a second axis B2 extending radially from the central axis X of the shaft 102 to the second lumen 114. As shown, the distal lumens 112, 114 are spaced angularly apart from one another by angle a between axes Bl and B2 along an arc defined by the side wall of the shaft. The angle a can be any angle greater than zero degrees and less than 180 degrees. In the example shown, the angle a is 120 degrees. In other words, the pull wire lumens 114 are spaced apart from one another circumferentially about the circumference of the shaft.

[0058] This dual wire configuration allows the shaft 102 to have a primary flexing section (e.g., corresponding to the proximal section 118 of the steerable distal portion 116) and secondary flexing section (e.g., corresponding to the distal section 120 of the steerable distal portion 116). [0059] Further details of the construction of the catheter shaft, exemplary catheter materials, durometers, and configurations can be found, at least, in US Patent No. 10,076,638 and US Publication No. 2022/0096229, which is incorporated by reference herein in its entirety.

[0060] When one or both pull wires 104, 106 are under tension, the primary flexing section 1 18 flexes or curves in a respective flexing plane P (FIG. 5). By virtue of the pull wires extending through a common pull- wire lumen (or extending through separate lumens in very close proximity to each other), tensioning either one or both pull wires is effective to adjust the curvature of the primary flexing section 118 in its respective flexing plane P. By applying differential tension to the pull wires, the secondary flexing section 120 can be caused to flex in various different directions relative to the primary flexing section 118. For example, applying the same amount of tension to each pull wire 104, 106 causes the secondary flexing section 120 to curve in the same plane P as the primary flexing section. Increasing tension in the first pull wire 104 relative to the second pull wire 106 causes the secondary flexing section 120 to curve or bend in a first direction away from the plane P of the primary flexing section 118 (shown in solid lines in FIG. 6). Likewise, increased tension in the second pull wire 106 relative to the first pull wire 104 causes the secondary flexing section 120 to curve or bend in a second direction, opposite the first direction, away from the plane P of the primary flexing section 118 (shown in phantom in FIG. 6).

[0061] In the illustrated example, the secondary flexing section 120 permits a distal tip of the catheter device 100 to access a locus approximated by a portion of a surface of a sphere defined by a first range of flexion and a second range of flexion, which in some examples corresponds to the angular components of a spherical coordinate system. The first range has an angular width or azimuthal width a (FIG. 5) (bounded by the radial axes Bi and B2). The second range has polar angle with a minimum at or near the X axis (about 0°) and a maximum dependent on the durometer and length of the secondary flexing section 120 (maximally flexed state). Accordingly, tensioning pull wire 104, optionally while partially untensioning pull wire 106, flexes the secondary flexing section 120 radially outwards generally along axis Bi. Similarly, pull wire 106 is operable to flex the secondary flexing section 120 along axis B2. By adjusting the relative tensions between the pull wires 104, 106, the distal tip of the catheter device 100 can be steered to any intermediate location or point in this space. [0062] The secondary flexing section 120 can thus be made to flex in any radial flexing plane within angle a. The angular positioning of the lumens 112, 114 and the pull wires 104, 106 thus defines the azimuthal or first range of flexion a for the secondary flexing section 120. In the example shown in, this direction of flexion can be in any plane between -60° and +60° relative to the primary flexing plane, wherein the 0° direction is the primary flexing plane P. Accordingly, in this case, the first range of flexion a is 120°. In other examples, the angle a and the corresponding first range of flexion can vary, such as 140° (-70° to +70°), 130° (-65° to +65°), 110° (-55° to +55°), 100° (-50° to +50°), 90° (-45° to +45°), 80° (-40° to +40°), 70° (-35° to +35°), or 60° (-30° to +30°).

[0063] In other examples, the first range of flexion of the secondary flexing section 120 need not be symmetrical relative to the primary flexing plane P. For example, the portion of the first pull wire 104 in the first distal lumen 112 can be angularly spaced from the main pull wire lumen 108 (and the primary flexing plane P) a first angle Oi and the portion of the second pull wire 106 in the second distal lumen 114 can be angularly spaced from the main pull wire lumen 108 (and the primary flexing plane P) a second angle 02, wherein 6i and 02 are not equal to each other. In this manner, the first range of flexion of the secondary flexing section 120 encompasses the primary flexing plane P but can be adjusted to extend further on one side of the primary flexing plane P than the other.

[0064] FIG. 7 illustrates an exemplary assembly 200 for making a catheter including a diverging pull wire path, such as or similar to catheter 100 described previously. The assembly 200 can include a splitter member 202, a mandrel 204, and one or more pull wire tubes 206. Each pull wire tube 206 can be a tube configured to define a pull wire lumen in which a pull wire can be disposed. The pull wire tubes 206 can comprise a low-friction and/or flexible liner or coating such as polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ultra-high-molecular-weight polyethylene (UHMWPE), fluorinated ethylene propylene (FEP), or another suitable material. In some instances, in lieu of or in addition to being disposed within a pull wire tube, a portion of the pull wire can be embedded directly in the wall of the catheter shaft.

[0065] The splitter member 202 can be configured to position the one or more pull wire tubes 206 in a first configuration (e.g., such that the tubes are grouped together and/or directly adjacent one another) along a first end portion 208 of the mandrel 204 and to position the plurality of pull wires tubes 206 in a second configuration (e.g., such that the tubes are angularly spaced apart from one another) along a second end portion 210 of the mandrel 204 and to hold the tubes 206 in position during the assembly of the catheter shaft. The splitter member 202 thus defines a divergence point 212 between the first tube configuration and the second tube configuration. The divergence point marks the point at which the catheter shaft changes from the primary flexing section to the secondary flexing section.

[0066] Though the illustrated example shows two pull wire tubes 206 (e.g., first pull wire tube 206a and second pull wire tube 206b), it should be understood that a greater or fewer number of pull wire tubes could be used. For example, one, three, four, five, six, seven, eight, nine, or ten pull wire tubes could be used.

[0067] Referring still to FIG. 7, as mentioned, the mandrel 204 can have a first end portion 208 (e.g., a proximal end portion) and a second end portion 210 (e.g., a distal end portion). In some examples, such as the illustrated example, the mandrel 204 can have a D-shape in cross section such that it includes a flat surface 214 and a curved surface 216. The mandrel 204 can therefore also be referred to as a “D-shaped mandrel.” In some examples, the flat surface 214 can have a first width Wi at the first end portion 208 of the mandrel 204 and a second width W2 at the second end portion 210 of the mandrel. In some examples, such as the illustrated example, the second width Wi can be wider than the first width Wi. In other examples, the second width W2 can be the same or narrower than the first width Wi.

[0068] Referring to FIG. 8, the splitter member 202 can comprise a main body 218 having a first, or proximal end portion 220 and a second, or distal end portion 222 connected by a neck portion 224. The neck portion 224 can have a width W3 narrower than the width Wi of the first end portion 220 and the width W2 of the second end portion 222.

[0069] The first end portion 220 can comprise first and second projections 226 extending upwardly from a first surface 228 of the main body 218 and defining a channel 230 between them. The channel 230 can comprise a ramped surface 232 at the proximal end thereof. The channel 230 can be configured to receive one or more pull wire tubes 206, as shown in FIG. 7, and position them such that they are adjacent one another. The projections 226 can have a height greater than a diameter of the pull wire tubes 206 such that the pull wires are retained within the channel 230. The projections 226 can also extend laterally from the main body 218, such that they are disposed on the curved surface 216 of the mandrel when the splitter member 202 is positioned on the mandrel 204.

[0070] The second end portion 222 can comprise one or more lateral projections 234. The lateral projections 234 can be configured to retain the distal end portions 236 (FIG. 7) of the one or more pull wire tubes 206 in a selected position on the mandrel 204. In the illustrated example, the one or more lateral projections comprise first and second lateral projections 234a, 234b, however, in other examples there can be a fewer or greater number of lateral projections 234. As shown in FIG. 7, the lateral projections 234 can curve downwardly relative to the main body 218 such that when the splitter member 202 is disposed on the D- shaped mandrel 204, the main body 218 is disposed on the flat surface 214 and the lateral projections 234 are disposed on the curved surface 216. The length of the lateral projections 234 can be adjusted based on the desired angular spacing between the first and second pull wire tubes 206a, 206b.

[0071] During assembly of a catheter shaft, the splitter member 202 can be disposed on the mandrel 204 at a selected position (i.e., divergence point) that defines the transition between the primary flexing section and the secondary flexing section of the assembled catheter. In some examples, the selected position can be between 10 mm to 50 mm from the distal end of the mandrel 204 (and therefore the distal end of the assembled catheter). As shown in FIG. 7, the splitter member 202 can be disposed on the mandrel 204 such that the first end portion 220 is oriented toward the proximal end 208 of the mandrel 204 and the second end portion 222 is oriented toward the distal end 210 of the mandrel.

[0072] In some examples, a first layer or liner layer can be disposed on the mandrel 204 prior to positioning the splitter member 202 thereon. The liner layer can comprise, for example, polytetrafluoroethylene (PTFE).

[0073] With the splitter member 202 positioned on the mandrel 204 (or on the liner layer), one or more pull wire tubes 206 (e.g., first and second pull wire tubes 206a, 206b in the illustrated example) can be disposed along the flat surface 214 of the proximal end 208 of the mandrel 204 in a first configuration, e.g., such that they adj cent/in close proximity to one another. A proximal end portion 238 of each of the pull wire tubes 206 can be disposed within the channel 230 of the splitter member 202. Upon exiting the channel 230 the pull wire tubes 206 can be angled/bent away from one another such that they assume a second configuration wherein they are spaced apart from one another about a circumference of the mandrel 204 by an angle a (see e.g., FIG. 5). The distal end portions 236 of the pull wire tubes 206 can be retained in the spaced apart configuration by the lateral projections 234, as shown in FIG. 7.

[0074] Once the splitter member 202 and pull wire tubes 206 are arranged in the desired configuration, a second layer (e.g., a braid layer) can be disposed on top of the splitter member 202 and pull wire tubes 206. A third or outer layer, such as a polymer layer, can then be disposed on top of the second layer. In some examples, the third or outer layer can be a polymeric covering, such as a poly ether block amide (commercially available as Pebax®), nylon, or any other suitable biocompatible polymer.

[0075] The catheter shaft can then be reflowed (e.g., melted) such that the layers (including the splitter member 202 and pull wire tubes 206) are coupled together due to the melting and flowing of the polymer layers. Reflowing may be achieved by positioning the mandrel 204 (and the components disposed thereon) within a heat source (e.g., an oven) or by using heat shrink tubing or other known methods.

[0076] In some examples, the catheter can comprise a third pull wire tube 206 disposed between the first and second pull wire tubes 206a, 206b that does not change direction along the length of the catheter shaft. In other words, the third tube runs straight along the length of the shaft. In such examples, a third pull wire extending through the third pull wire tube 206 can be tensioned to achieve the primary flex in plane P, which allows pull wires disposed within the first and second pull wires tubes 206a, 206b to perform the secondary flexing without holding tension from the primary flex.

[0077] FIG. 9 illustrates another example of a splitter member 300. Splitter member 300 can be used in lieu of or in addition to splitter member 202 described previously, such as in any of the catheter shafts describe herein and/or in catheter making assembly 200 described previously. Similarly to splitter member 202, splitter member 300 defines a divergence point within the catheter shaft wherein the one or more pull wire tubes (e.g., tubes 206 shown in FIG. 7) change from a first configuration to a second configuration, thereby delineating the transition from the primary flexing section of the catheter shaft to the secondary flexing section.

[0078] The splitter member 300 can comprise a first member 302 and a second member 304. In the illustrated example, both the first member 302 and the second member 304 have a main body (306 and 308, respectively) comprising an annular shape. However, in other examples, one or both of the first and second members 302, 304 can have any of various other shapes, for example, a C-shape in cross-section (also referred to as an arced shape).

[0079] The main body 306 of the first member 302 can comprise a first end portion 310 having a first surface 312, a second end portion 314 having a second surface 316, and a side wall 318 extending between the first and second surfaces. The first member 302 can have a recess 320 extending from the second surface 316 into the side wall 318 toward the first surface 312. In some examples, the recess 320 can have a curved V-shape similar to a “curly bracket.” In other examples, the recess 320 can have any of various other shapes, such as, for example, a semi-circular shape.

[0080] The recess 320 can define first and second sides culminating at an apex 322. Each side can comprise a channel 324 extending further into the side wall 318 and configured (e.g., sized and shaped) to receive a pull wire tube or pull wire. The first member 302 can further define first and second openings 326 extending through a length of the first member 302 at the apex 322 of the recess 320. Each of the first and second openings 326 can be contiguous with a respective channel 324. The openings 326 can be configured such that a respective pull wire tube or pull wire can be disposed within each opening. As shown, the openings 326 can be grouped together such that pull wire tubes or pull wires entering the first end portion 310 of the first member 302 are disposed adjacent one another.

[0081] The main body 308 of the second member 304 can comprise a first end portion 328 having a first surface 330, a second end portion 332 having a second surface 334, and a sidewall 336 extending between the first and second surfaces. The second member 304 can further comprise a projection 338 extending from the first surface 330. The projection 338 can have a shape corresponding to the recess 320 of the first member 302 such that the projection 338 can be disposed within the recess 320. The edge surface 340 of the projection 338 can comprise first and second channels 342 that align with the first and second channels 324 of the recess 320. The channels 324, 342 can each have a semi-circular shape in crosssection. Accordingly, when the projection 338 is disposed within the recess 320, the channels 324, 342 define an enclosed cylindrical lumen configured to receive a pull wire tube.

[0082] The second member 304 can define first and second openings 344 extending through a length of the second member 304. Each of the first and second openings 344 can be contiguous with a respective channel 342 of the projection 338. The openings 344 can be configured such that a respective pull wire tube can be disposed within each opening. As shown, the openings 344 can be spaced apart from one another about a circumference of the second member 304 such that pull wire tubes disposed within the openings 344 are angularly offset from one another.

[0083] When the projection 338 of the second member 304 is disposed within the recess 320 of the first member 302, the enclosed lumens defined by the channels 324, 342 form diverging paths each configured to receive a respective pull wire tube (or pull wire) and to maintain the pull wire tube in a first location at the first end portion 310 and a second location at the second end portion 332, the first location being angularly offset from the second location.

[0084] Though the above description refers to multiple channels and multiple pull wire tubes (e.g., two channels each configured to receive a pull wire tube) it should be understood that the splitter member 300 can be configured for use with a lesser or greater number of pull wire tubes. For example, the splitter member 300 can be configured to receive a single pull wire tube and redirect the single wire tube from a first circumferential location about the circumference of the catheter shaft to a second circumferential location, the second circumferential location being angularly offset from the first. In other examples, the splitter member 300 can be configured to receive and redirect three or more pull wire tubes.

[0085] In some examples, the first and/or second members 302, 304 can each comprise one or more openings 346 extending through the side wall 318, 336 of the respective member. The openings 346 can be configured to allow the outer and/or inner layers of the shaft to flow and bond together during the reflow process, thereby capturing the splitter member 300 within the wall of the catheter shaft such that the splitter member is held in place rotationally and axially relative to the catheter shaft. In the illustrated example, the first member 302 comprises two openings 346 that are angularly offset from one another about a circumference of the first member, and the second member 304 comprises one opening 346 disposed in the projection 338. However, in other examples, each of the members 302, 304 can comprise a greater or fewer number of openings. In the illustrated example, the openings 346 are circular, however, in other examples, the openings 346 can have any of various shapes including but not limited to square, semi-circular, triangular, rectangular, ovular, etc.

[0086] During assembly of a catheter shaft, the splitter member 300 can be disposed on a mandrel (e.g., a conventional round mandrel) at a selected position that defines the transition between the primary flexing section and the secondary flexing section of the assembled catheter. In some examples, the selected position can be between 10 mm to 50 mm from the distal end of the mandrel (and therefore the distal end of the catheter). The splitter member 300 can be disposed on the mandrel such that the first member 302 is adjacent the proximal end of the mandrel and the second member 304 is adjacent the distal end of the mandrel.

[0087] In some examples, one or more underlayers can be disposed on the mandrel prior to positioning the splitter member 300 thereon. For example, a first or liner layer can be disposed directly on the mandrel. The liner layer can comprise, for example, polytetrafluoroethylene (PTFE). In some examples, a first polymer tie layer can be disposed over the liner layer, and a braided tube layer can be disposed on the first polymer tie layer. The braided tube later can be, for example, a braided metal wire tube, or any other construction exhibiting suitable stiffness properties. In some examples, the braided layer can be a 0.001 inch by 0.005 inch braid. A second polymer tie layer can be disposed over the braided tube layer, and the splitter member 300 and pull wire tubes can be disposed thereon.

[0088] In some examples, the catheter shaft can further comprise one or more overlayers disposed over the splitter member 300, pull wire tubes, and other components disposed on the mandrel. For example, the catheter shaft can comprise a second braided tube layer, also referred to as an outer braid layer, disposed over the previous layer, and an outer polymer layer disposed on the outer braid layer.

[0089] The catheter shaft can then be reflowed (e.g., melted) such that the layers (including the splitter member 300 and pull wire tubes) are coupled together via to the melting, flowing, and re-hardening of the polymer layers. Reflowing may be achieved by positioning the mandrel (and the components disposed thereon) within a heat source (e.g., an oven) or by using heat shrink tubing or other known methods.

[0090] Referring to FIG. 10, after the re-flowing process, a ring member 350 and pull wire 352 can be added to the catheter shaft using a tipping process. The tipping process can comprise heating just the distal tip portion of the catheter shaft and inserting the pull ring 350. In some examples, this can comprise pressing the distal tip of the catheter shaft to a heated die comprising the ring member 350 and/or pull wire 352. In other examples, the tipping process can comprise inserting just the distal tip into a heating element such as an oven before inserting the ring member 350 and/or pull wire 352.

[0091] The ring member 350 can comprise an annular main body 354 and a cylindrical member 356 coupled to the main body and defining a lumen configured to receive the distal end portion 358 of a pull wire 352 or a pull wire tube. Though the illustrated example shows a single pull wire, it should be understood that the ring member 350 can alternatively be coupled to two or more pull wires 352, or two or more pull wire tubes. The main body 354 can comprise a recess 360 extending from a proximal end portion 362 into a sidewall 364 of the main body. In some examples, such as the illustrated example, the cylindrical member 356 is disposed within the recess 360 and coupled to the main body 354. In the illustrated example, the recess 360 is substantially Y-shaped, however, in other examples, the recess can have any of various shapes, such as a V-shape, a semi-circular shape, a C-shape, a U -shape, etc.

[0092] In some examples, the pull wire 352 can be a cable comprising a plurality of strands, which can provide additional flexibility and ease insertion of the cable into the catheter shaft.

[0093] The ring member 350 comprises one or more openings 366 extending through the sidewall 364 of the main body 354. The openings 366 can be configured to allow the outer and/or inner layers of the shaft to flow and bond together during the reflow process, thereby capturing the ring member 350 within the wall of the catheter shaft such that the ring member is held in place rotationally and axially relative to the catheter shaft. In the illustrated example, the ring member 350 comprises seven rows of three openings each, resulting in twenty-one openings 366. However, in other examples, the ring member 350 can have a greater or fewer number of openings. In the illustrated example, the openings 366 are circular, however, in other examples, the openings 366 can have any of various shapes including but not limited to square, semi-circular, triangular, rectangular, ovular, etc.

[0094] FIGS. 11-12 illustrate another example of a catheter 400 comprising a diverging pull wire path such that the catheter 400 has a primary flex section (indicated generally at 402) and a secondary flex section (indicated generally at 404) similar to catheter 100 described previously. The catheter 400 comprises one or more pull wire tubes 406, each configured to receive a pull wire. Though the example herein refers to pull wire tubes, it should be understood that in some examples, pull wires can be embedded directly within the wall of the catheter shaft without a pull wire tube. Un the illustrated example, the catheter 400 comprises first and second pull wire tubes 406a, 406b however, in other examples, the catheter 400 can comprise a greater or fewer number of pull wire tubes. FIGS. 11-12 illustrate selected layers of the catheter shaft 400, however, it should be understood that the catheter shaft 400 can comprise a greater or fewer number of layers in some examples.

[0095] Referring to FIG. 11, the catheter 400 can comprise a first or inner layer 408 (also referred to as a liner layer) which is disposed on the mandrel during assembly of the catheter shaft 400. A second layer 410 can then be disposed on top of the liner layer 408. In some examples, such as the illustrated example, the second layer 410 can comprise a flat wire coil 412, such as a stainless-steel flat wire coil. In some examples, the second layer 410 can comprise a metal tube or a laser-cut metal tube, such as a laser-cut hypotube including one or more cut patterns along its length. In some examples, the second layer 410 can extend nearly the full length of the catheter shaft 400, leaving a section at the distal end portion 414 of the catheter shaft 400 that does not include the second layer 410, as shown in FIG. 11.

[0096] The coil 412 can wind helically around the mandrel such that it defines a plurality of rings 416 separated by a plurality of gaps 418. In some examples, as shown in FIG. 11, the gaps 418 at the distal end portion 420 of the coil 412 can be narrower than the gaps 418 along the length of the catheter shaft 400. This can provide extra support for the pull wire tubes 406 (and/or for pull wires disposed within the pull wire tubes) preventing or mitigating the pull wire tubes 406 from collapsing into the inner diameter of the catheter 400 when the pull wires are tensioned. [0097] The pull wire tubes 406 can be disposed on the second layer 410. In some examples, an adhesive can be used to couple the pull wire tubes 406 to the second layer 410 at the point where the wires diverge (also called the “divergence point” 422). In other examples, a collar, band, or splitter member (such as splitter members 202 and/or 300 described herein) can be disposed at the divergence point 422 to maintain the pull wire tubes 406 in the desired configuration.

[0098] The distal end portions 424 of the pull wire tubes 406 can be coupled to a splitter band 426 disposed at the distal end portion 414 of the catheter shaft 400. The splitter band 426 can comprise an annular main body 428. In some examples, the splitter band 426 can comprise one or more openings 430 extending through a thickness of the main body 428. The openings 430 can be configured to allow the outer and/or inner layers of the shaft to flow and bond together during the reflow process, thereby capturing the splitter band 426 within the wall of the catheter shaft such that the splitter band 426 is held in place rotationally and axially relative to the catheter shaft. In the illustrated example, the splitter band 426 comprises three openings 430 spaced circumferentially apart from one another about the circumference of the annular main body 428, however, in other examples, the splitter band 426 can comprise a greater or fewer number of openings, including no openings.

[0099] As shown in FIG. 11, a third layer 432 can be disposed partially over the pull wire tubes 406. The third layer 432 can be configured as a coil layer 434 that winds helically such that it defines a plurality of rings 436 separated by a plurality of gaps 438. The third layer 432 can comprise a material configured not to melt under reflow temperatures such that it retains its shape during the catheter assembly process. In some examples, the third layer 432 can comprise a polymer, for example a high temperature engineering polymer such as polyimide (PI). The third layer 432 can have a length L such that it extends over the divergence point 422 but does not extend the entire length of the catheter shaft 400.

[0100] In some examples, such as shown in FIG. 12, the catheter 400 can comprise a splitter member 440 comprise a main body 442 defining one or more lumens 444 extending through a length of the main body 442. In some examples, such as the illustrated example, the main body 442 can have an overall curved shape such that it defines a C-shape in cross section. In other examples, the splitter member 440 can be an annular member that extends fully around the diameter of the catheter shaft 400. The lumens 444 can be sized to each receive a respective pull wire tube 406 and can be positioned to maintain the pull wire tubes 406 at a desired location relative to one another, e.g., spaced apart from one another a selected distance about the circumference of the catheter shaft 400. In some examples, such as the illustrated example, the splitter member 440 can be disposed adjacent the distal end 446 of the third layer 432.

[0101] In some examples, the catheter shaft 400 can further comprise an additional layer, such as a second stainless steel coil layer inside the third layer 432. The additional layer can be configured to hold the pull wire tubes in close proximity to one another at a location proximal to the divergence point 422.

[0102] In some examples, a fourth layer can be disposed on top of the third layer 432. The fourth layer can comprise, for example, a braided tube, such as a braided metal wire tube, or any other construction exhibiting suitable stiffness properties.

[0103] An outer layer, such as a polymer layer, can then be disposed on top of the components. The catheter shaft 400 can then be reflowed (e.g., melted) such that the polymer layers melt and all layers of the shaft are coupled together. Reflowing may be achieved by positioning the mandrel (and the components disposed thereon) within a heat source (e.g., an oven) or by using heat shrink tubing or other known methods.

[0104] FIG. 13 illustrates another example of a mandrel 500 used to create a diverging pull wire path within a catheter shaft, such as catheter shaft 100 described previously. The mandrel 500 can comprise a first member 502 configured as a proximal member and a second member 504 configured as a distal member, which together form a main body 506. The first and second members 502, 504 can be releasably coupled together via any of various mechanical means, e.g., screws or other mechanical fasteners, friction fit, snap fit, etc. FIG. 13 shows the first member 502 with a pattern added for purposes of illustration. The pattern is added to distinguish the first member 502 from the second member 504 and does not represent actual surface ornamentation.

[0105] As shown in FIG. 13, the first and second members 502, 504 can each have a substantially cylindrical shape. The second member 504 can comprise a projection 508 extending from a first or proximal end portion 512 thereof and configured to be received within a corresponding recess 510 of the second or distal end portion 514 of the first member 502. Each of the first and second members 502, 504 can comprise one or more channels 516 extending from the surface 518 of the main body 506 toward a longitudinal axis A thereof and also along a length of the main body. The channels 516 can be configured (e.g., sized and shaped) to receive a pull wire tube therein and thereby define a selected pull wire path for the pull wire tubes to follow during assembly of the catheter.

[0106] As shown in FIG. 13, in some examples, the first member 502 can comprise first and second channels 516a, 516b. The channels 516a, 516b can be disposed in a first configuration at the first end portion 520 (e.g., a proximal end portion) of the first member 502 and can continue in the first configuration along the length of the first member 502 until a divergence point 522 at which point the channels 516a, 516b assume a second configuration. For example, the first configuration can comprise the channels 516a, 516b being disposed adjacent one another as shown in FIG. 13. The channels 516a, 516b can extend substantially parallel to one another along the length of the first member 502 until they reach the divergence point 522 at which point they curve away from one another to define angled portions 524 before forming the second configuration, wherein they are spaced apart from one another about a circumference of the mandrel 500 (also referred to as being angularly offset from one another). The second configuration can continue along the length of the second member 504. As shown, the divergence point 522 can be positioned at the apex of the projection 508 and the bottom of the recess 510.

[0107] In some examples, such as the illustrated example, the angled portions 524 of the channels 516 are disposed partially on the first member 502 and partially on the second member 504. This allows the first and second members 502, 504 to be removed from the assembled catheter shaft without disrupting the path of the pull wire tubes.

[0108] In other examples, the channels 516 can be arranged to form a different wire path. For example, in some instances the mandrel 500 can comprise three channels 516, with the third channel disposed between the first and second channels 516a, 516b and extending straight along the length of the mandrel 500. In some examples, the angled portions of the first and second channels 516a, 516b can be positioned at different angle than the angle shown in FIG. 13, such that the proximal end portions of the channels 516a, 516b are disposed at a different position about the circumference of the mandrel relative to one another. [0109] During a catheter assembly process, the first and second members 502, 504 can be coupled together as shown in FIG. 13 and one or more pull wire tubes can be disposed within the channels 516. The catheter (e.g., catheter 100 described previously) can then be assembled using known construction methods (e.g., positioning a plurality of layers over the mandrel and re-flowing the layers together to create a catheter shaft). Once the catheter is complete, the first and second members 502, 504 can be separated from one another. The first member 502 can be removed from the catheter in a proximal direction, and the second member 504 can be removed from the catheter in a distal direction. As can be seen in FIG. 13, the split between the first and second members 502, 504 runs along the angled portion 524 of the channels 516. This allows the first and second members 502, 504 to be pulled apart from one another and removed from the inner lumen of the catheter without disrupting the path of the pull wire tubes.

[0110] Any of the systems, devices, apparatuses, etc. herein can be sterilized (for example, with heat/thermal, pressure, steam, radiation, and/or chemicals, etc.) to ensure they are safe for use with patients, and any of the methods herein can include sterilization of the associated system, device, apparatus, etc. as one of the steps of the method. Examples of heat/thermal sterilization include steam sterilization and autoclaving. Examples of radiation for use in sterilization include, without limitation, gamma radiation, ultra-violet radiation, and electron beam. Examples of chemicals for use in sterilization include, without limitation, ethylene oxide, hydrogen peroxide, peracetic acid, formaldehyde, and glutaraldehyde. Sterilization with hydrogen peroxide may be accomplished using hydrogen peroxide plasma, for example.

[0111] The treatment techniques, methods, steps, etc. described or suggested herein or in references incorporated herein can be performed on a living animal or on a non-living simulation, such as on a cadaver, cadaver heart, anthropomorphic ghost, simulator (for example, with the body parts, tissue, etc. being simulated), etc.

Additional Examples of the Disclosed Technology

[0112] In view of the above-described implementations of the disclosed subject matter, this application discloses the additional examples enumerated below. It should be noted that one feature of an example in isolation or more than one feature of the example taken in combination and, optionally, in combination with one or more features of one or more further examples are further examples also falling within the disclosure of this application.

[0113] Example 1. A catheter device comprising: a shaft comprising a proximal portion, a steerable distal portion, one or more layers forming a wall, and one or more pull wire tubes disposed in the wall, wherein the pull wire tubes are disposed at a first circumferential location of the shaft in the proximal portion of the shaft; and a splitter member disposed within the wall of the shaft, the splitter member defining a divergence point where the one or more pull wire tubes diverge from the first circumferential location to a second circumferential location in the steerable distal portion of the shaft, the second circumferential location being circumferentially offset from the first circumferential location.

[0114] Example 2. The catheter device of any example herein, particularly example 1, wherein the one or more pull wire tubes comprises first and second pull wire tubes and wherein when the first and second pull wire tubes are in the first circumferential location they are grouped together.

[0115] Example 3. The catheter device of any example herein, particularly example 2, wherein at the divergence point the first and second pull wire tubes diverge from one another around the circumference of the shaft to respective second circumferential locations at a selected circumferential offset from one another.

[0116] Example 4. The catheter device of any example herein, particularly any one of examples 1-3, further comprising one or more pull wires disposed within the one or more pull wire tubes, and wherein the one or more pull wires are coupled to a pull ring disposed at a distal end of the shaft.

[0117] Example 5. The catheter device of any example herein, particularly any one of examples 1-4, wherein the splitter member comprises a proximal end portion comprising first and second projections defining a channel between them, and wherein the one or more pull wire tubes are disposed within the channel.

[0118] Example 6. The catheter device of any example herein, particularly example 5, wherein the splitter member comprises a distal end portion comprising one or more lateral projections configured to retain the one or more pull wire tubes at the second circumferential location. [0119] Example 7. The catheter device of any example herein, particularly any one of examples 1-4, wherein the splitter member comprises a first annular member and a second annular member, the first annular member having a proximal end portion including one or more openings configured to retain the one or more pull wire tubes at the first circumferential location.

[0120] Example 8. The catheter device of any example herein, particularly example 7, wherein the second annular member comprises a distal end portion including one or more openings configured to retain the one or more pull wire tubes at the second circumferential location.

[0121] Example 9. The catheter device of any example herein, particularly any one of examples 7-8, wherein the second annular member comprises a projection configured to be disposed in a corresponding recess of the first annular member and wherein an edge surface of the projection and an edge surface of the recess each comprise one or more channels such that when the projection is disposed in the recess the channels form one or more lumens configured to receive the one or more pull wire tubes.

[0122] Example 10. The catheter device of any example herein, particularly any one of examples 1-9, further comprising an additional pull wire tube, wherein the additional pull wire tube remains in a first circumferential location from the proximal portion of the shaft to the steerable distal portion of the shaft.

[0123] Example 11. The catheter device of any example herein, particularly any one of examples 1-10, further comprising a liner layer radially inward of the splitter member and a flexible polymeric layer radially outward of the splitter member.

[0124] Example 12. The catheter device of any example herein, particularly example 11, wherein the liner layer comprises polytetrafluoroethylene (PTFE).

[0125] Example 13. A delivery apparatus comprising: a handle; and the catheter device of any example herein, particularly any one of examples 1-12 coupled to the handle.

[0126] Example 14. A catheter device comprising a shaft comprising a steerable distal portion, a proximal portion, and a plurality of layers including a liner layer, a first coil layer extending a first length along substantially a full length of the shaft, and a second coil layer extending a second length less than the first length; a first pull wire tube disposed between the first coil layer and the second coil layer; and a second pull wire tube disposed between the first coil layer and the second coil layer, wherein the first and second pull wire tubes are disposed adjacent one another in a first configuration at a proximal end of the second coil layer, and wherein at a divergence point on the shaft, the first and second pull wire tubes diverge from one another around a circumference of the shaft to a second configuration wherein the first and second pull wire tubes are disposed at a selected angular offset from one another.

[0127] Example 15. The catheter device of any example herein, particularly example 14, wherein the first and second pull wire tubes are coupled to the first coil layer at the divergence point.

[0128] Example 16. The catheter device of any example herein, particularly example 15, wherein the first and second pull wire tubes are coupled to the first coil layer using an adhesive.

[0129] Example 17. The catheter device of any example herein, particularly any one of examples 14-16, further comprising a splitter member disposed on the first coil layer at a location distal to a distal end portion of the second coil layer, the splitter member configured to help retain the first and second pull wire tubes in the second configuration.

[0130] Example 18. A mandrel for making a catheter device, comprising a first member; a second member releasably coupled to the first member; and one or more channels disposed on an outer surface of the first and second members, the one or more channels extending in a first configuration along a length of the first member until a divergence point; wherein at the divergence point, the one or more channels diverge around a circumference of the mandrel to a second configuration extending along a length of the second member.

[0131] Example 19. The mandrel of any example herein, particularly example 18, wherein the one or more channels comprise angled portions and wherein the angled portions are disposed such that a first portion of the angled portion is on the first member and a second portion of the angled portion is on the second member.

[0132] Example 20. The mandrel of any example herein, particularly any one of examples 18-19, wherein the first and second members are releasably coupled to one another using screws.

[0133] Example 21. A method of making a catheter device, comprising disposing a first layer on a mandrel, the mandrel comprising a proximal end portion and a distal end portion; positioning a pull wire tube on the first layer such that a proximal end portion of the pull wire tube is disposed in a first circumferential location at the proximal end portion of the mandrel and diverges at a selected divergence point to a second circumferential location circumferentially offset from the first circumferential location; disposing a flexible polymer layer over the pull wire tube; and reflowing the flexible polymer layer and first layer to form a catheter shaft.

[0134] Example 22. The method of any example herein, particularly example 21, further comprising disposing a splitter member on the first layer, the splitter member comprising a proximal end portion and a distal end portion; and wherein positioning the pull wire tube on the first layer comprises disposing the pull wire tube on the splitter member such that the proximal end portion of the splitter member retains a proximal end portion of the pull wire tube in the first circumferential location and the distal end portion of the splitter member retains a distal end portion of the pull wire tube in the second circumferential location.

[0135] Example 23. The method of any example herein, particularly example 22, wherein the proximal end portion of the splitter member comprises first and second projections defining a channel between them, and wherein the pull wire tube is disposed within the channel.

[0136] Example 24. The method of any example herein, particularly example 23, wherein the distal end portion of the splitter member comprises one or more lateral projections configured to retain the one or more pull wire tubes at the second circumferential location. [0137] Example 25. The method of any example herein, particularly example 22, wherein the splitter member comprises a first annular member and a second annular member, and wherein the proximal end portion of the splitter member includes one or more openings configured to retain the one or more pull wire tubes at the first circumferential location.

[0138] Example 26. The method of any example herein, particularly example 25, wherein the distal end portion of the splitter member includes one or more openings configured to retain the one or more pull wire tubes at the second circumferential location.

[0139] Example 27. The method of any example herein, particularly any one of examples 25-26, wherein the second annular member comprises a projection configured to be disposed in a corresponding recess of the first annular member and wherein an edge surface of the projection and an edge surface of the recess each comprise one or more channels such that when the projection is disposed in the recess the channels form one or more lumens configured to receive the one or more pull wire tubes. [0140] Example 28. The catheter device of any example herein, particularly examples 1-20, wherein the catheter device is sterilized.

[0141] Example 29. A method of sterilizing any of the catheter devices described herein, particularly any of the catheter devices of examples 1-20.

[0142] The features described herein with regard to any example can be combined with other features described in any one or more of the other examples, unless otherwise stated. For example, any one or more of the features of one splitter member, catheter shaft, or mandrel can be combined with any one or more features of any of the other splitter members, catheter shafts, or mandrels described herein. As another example, any one splitter member and/or any mandrel can be combined with any catheter shaft.

[0143] In view of the many possible ways in which the principles of the disclosure may be applied, it should be recognized that the illustrated configurations depict examples of the disclosed technology and should not be taken as limiting the scope of the disclosure nor the claims. Rather, the scope of the claimed subject matter is defined by the following claims and their equivalents.

Claims

CLAIMS:

1. A catheter device comprising: a shaft comprising a proximal portion, a steerable distal portion, one or more layers forming a wall, and one or more pull wire tubes disposed in the wall, wherein the pull wire tubes are disposed at a first circumferential location of the shaft in the proximal portion of the shaft; and a splitter member disposed within the wall of the shaft, the splitter member defining a divergence point where the one or more pull wire tubes diverge from the first circumferential location to a second circumferential location in the steerable distal portion of the shaft, the second circumferential location being circumferentially offset from the first circumferential location.

2. The catheter device of claim 1 , wherein the one or more pull wire tubes comprises first and second pull wire tubes and wherein when the first and second pull wire tubes are in the first circumferential location they are grouped together.

3. The catheter device of claim 2, wherein at the divergence point the first and second pull wire tubes diverge from one another around the circumference of the shaft to respective second circumferential locations at a selected circumferential offset from one another.

4. The catheter device of any one of claims 1-3, further comprising one or more pull wires disposed within the one or more pull wire tubes, and wherein the one or more pull wires are coupled to a pull ring disposed at a distal end of the shaft.

5. The catheter device of any one of claims 1-4, wherein the splitter member comprises a proximal end portion comprising first and second projections defining a channel between them, and wherein the one or more pull wire tubes are disposed within the channel.

6. The catheter device of claim 5, wherein the splitter member comprises a distal end portion comprising one or more lateral projections configured to retain the one or more pull wire tubes at the second circumferential location.

7. The catheter device of any one of claims 1-4, wherein the splitter member comprises a first annular member and a second annular member, the first annular member having a proximal end portion including one or more openings configured to retain the one or more pull wire tubes at the first circumferential location.

8. The catheter device of claim 7, wherein the second annular member comprises a distal end portion including one or more openings configured to retain the one or more pull wire tubes at the second circumferential location.

9. The catheter device of any one of claims 7-8, wherein the second annular member comprises a projection configured to be disposed in a corresponding recess of the first annular member and wherein an edge surface of the projection and an edge surface of the recess each comprise one or more channels such that when the projection is disposed in the recess the channels form one or more lumens configured to receive the one or more pull wire tubes.

10. The catheter device of any one of claims 1-9, further comprising an additional pull wire tube, wherein the additional pull wire tube remains in a first circumferential location from the proximal portion of the shaft to the steerable distal portion of the shaft.

11. The catheter device of any one of claims 1-10, further comprising a liner layer radially inward of the splitter member and a flexible polymeric layer radially outward of the splitter member.

12. The catheter device of claim 11, wherein the liner layer comprises polytetrafluoroethylene (PTFE).

13. A delivery apparatus comprising: a handle; and the catheter device of any one of claims 1- 12 coupled to the handle.

14. A catheter device a shaft comprising a steerable distal portion, a proximal portion, and a plurality of layers including a liner layer, a first coil layer extending a first length along substantially a full length of the shaft, and a second coil layer extending a second length less than the first length; a first pull wire tube disposed between the first coil layer and the second coil layer; and a second pull wire tube disposed between the first coil layer and the second coil layer, wherein the first and second pull wire tubes are disposed adjacent one another in a first configuration at a proximal end of the second coil layer, and wherein at a divergence point on the shaft, the first and second pull wire tubes diverge from one another around a circumference of the shaft to a second configuration wherein the first and second pull wire tubes are disposed at a selected angular offset from one another.

15. The catheter device of claim 14, wherein the first and second pull wire tubes are coupled to the first coil layer at the divergence point.

16. The catheter device of claim 15, wherein the first and second pull wire tubes are coupled to the first coil layer using an adhesive.

17. The catheter device of any one of claims 14-16, further comprising a splitter member disposed on the first coil layer at a location distal to a distal end portion of the second coil layer, the splitter member configured to help retain the first and second pull wire tubes in the second configuration.

18. A mandrel for making a catheter device, comprising: a first member; a second member releasably coupled to the first member; and one or more channels disposed on an outer surface of the first and second members, the one or more channels extending in a first configuration along a length of the first member until a divergence point; wherein at the divergence point, the one or more channels diverge around a circumference of the mandrel to a second configuration extending along a length of the second member.

19. The mandrel of claim 18, wherein the one or more channels comprise angled portions and wherein the angled portions are disposed such that a first portion of the angled portion is on the first member and a second portion of the angled portion is on the second member.

20. The mandrel of any one of claims 18-19, wherein the first and second members are releasably coupled to one another using screws.