Manipulable Sheath with Variable Bending Span

Abstract

The present invention is titled "Manipulable Sheath with Variable Bending Span". The present invention discloses a guiding sheath assembly having a shaft that is operable to define more than one flexure curvature and define a lumen to slidably receive a cardiovascular catheter. The guiding sheath assembly includes a proximal segment, a distal segment, and a reinforcement member. The proximal segment has a proximal shaft that defines a proximal lumen extending distally along a longitudinal axis to the distal segment. The distal segment has a distal shaft that defines a distal lumen, and the distal shaft is configured to be laterally biased (e.g., elastically biased) away from the longitudinal axis. The reinforcement member is a rigid elongate member, such as an internal tubular member, that is configured to counteract the bias of the distal shaft. Longitudinal movement of the reinforcement member relative to the distal segment enables an operator to select and set the flexure curvature of the distal segment.

Description

[0001] Priority

[0002] This patent application is a partial continuation of the following U.S. patent application: U.S. Patent Application No. 14 / 715,013, filed on May 18, 2015, and published as U.S. Publication 2016 / 0339207 on November 24, 2016, entitled "Catheter with Adjustable Deflection", the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to electrophysiology (EP) catheters, and more particularly, to flexible catheters for use with EP catheters for mapping and / or ablation in the heart. Background Art

[0004] Electrode catheters have been commonly used in medical practice for many years. They are used to stimulate and map electrical activity in the heart, and to ablate sites of abnormal electrical activity.

[0005] In use, an electrode catheter is inserted into a major vein or artery (e.g., the femoral artery), and then guided into the heart chamber of interest. Inside the heart, the ability to control the precise position and orientation of the catheter tip is crucial, and this ability largely determines the usability of the catheter.

[0006] Manipulable (or flexible) catheters are generally well known. A typical catheter has an elongate catheter body, an intermediate flexure section, and a distal tip section. The elongate catheter body extends through the patient's vasculature, and the shorter intermediate flexure section is manipulated or flexed in response to a rocker arm on a control handle manipulated by an operator (e.g., an electrophysiologist) to reach the target tissue. The catheter typically employs a single lumen structure for the catheter body, and a multiple lumen structure for the intermediate flexure section, the multiple lumen structure providing dedicated lumens for each pull wire to facilitate flexure. Thus, the catheter is a composite of different constructs and materials, and may not have consistent properties in terms of flexibility, torsional stiffness, pushability, and / or rotational accuracy. Assembling the pull wires and their corresponding compression coils, feeding the distal portions of the pull wires through their dedicated lumens, and connecting the two structures all require a great deal of skilled manual labor. In addition, the inner walls of the multi-lumen tubing occupy valuable space inside the catheter.

[0007] Since the pull-wire actuated deflectable catheter relies on a junction of different flexibilities / stiffnesses between the catheter body and the deflectable segment, the shape (including the tightness of the curvature) depends on the position of the junction relative to the catheter length and / or the position of the distal anchor of the pull-wire. Thus, each of these catheters is designed and manufactured to provide a specific deflection curvature. Accordingly, depending on the specific cardiac anatomy of the patient being treated, the electrophysiologist needs to correctly select the catheter curvature, such as a catheter with a "J" deflection curvature or a catheter with an "F" deflection curvature, prior to the start of the procedure to match that cardiac anatomy. A smaller heart may require a catheter with a tighter or smaller deflection. A larger heart may require a catheter with a looser or larger deflection.

[0008] Accordingly, it is desirable for the catheter to have a more consistent construction throughout its length such that the construction and assembly process is simplified and the catheter exhibits more consistent flexibility, torsional stiffness, pushability, and / or rotational accuracy along its entire length. It is also desirable for the catheter to be adjustable to provide more than one deflection curvature in its catheter shaft.

[0009] In some procedures, it may be desirable to insert an electrode catheter into a patient's cardiovascular system via a guiding sheath. The guiding sheath may facilitate access to a target region (e.g., a pulmonary vein) and may also facilitate the sequential insertion and retraction of two or more electrode catheters (e.g., first an electrophysiology (EP) catheter and subsequently an ablation catheter). It may also be desirable to provide more than one deflection curvature in the guiding sheath.

[0010] Although several catheter systems, guiding sheaths, and associated methods have been made and used, it is believed that no one prior to the inventors has made or used the invention described, shown, and claimed herein. SUMMARY OF THE INVENTION

[0011] The present invention relates to a catheter having a catheter shaft that has a more consistent construction throughout its length, the catheter shaft including an elongate proximal segment and a distal deflectable segment, and the catheter shaft being capable of assuming more than one deflection curvature. The catheter shaft includes a flexible outer tubular member and a less flexible inner tubular member extending through the outer tubular member in the elongate proximal segment of the catheter shaft, wherein the inner tubular member is provided with longitudinal movement relative to the outer tubular member. The catheter further includes at least one pull-wire extending through the inner tubular member to deflect the distal deflectable segment of the catheter shaft, wherein the longitudinal movement of the inner tubular member relative to the outer tubular member enables an operator to select and set the deflection curvature of the distal deflectable segment.

[0012] In some embodiments, the catheter has a catheter shaft having an elongate proximal segment and a distal flexible segment. The catheter shaft has an outer tubular member having a first central lumen. The catheter also has an inner tubular member having a second central lumen, wherein the inner tubular member extends through the first central lumen of the outer tubular member. The catheter further includes at least one pull wire extending through the second central lumen, the pull wire being configured to flex the distal flexible segment. According to the features of the present invention, the inner tubular member has less flexibility and the outer tubular member has greater flexibility to define the proximal end of the distal flexible segment, and the inner tubular member is provided with longitudinal movement relative to the outer tubular member to enable an operator to adjust the position of the proximal end along the length of the catheter shaft.

[0013] In more detailed embodiments, the outer tubular member has a coil configuration, such as a multi-layer coil configuration, wherein each layer of the coil configuration has a winding direction different from one or more adjacent layers. For example, the inner layer has a winding in a first direction, the middle layer has a winding in a second direction generally opposite to the first direction, and the outer layer has a winding in the first direction.

[0014] In more detailed embodiments, the distal end of the inner tubular member is flat for symmetric bidirectional flexion, or the distal end of the inner tubular member is non-flat for asymmetric bidirectional flexion. The non-flat distal end can be inclined, notched, or stepped.

[0015] In some embodiments, the catheter has a catheter shaft and a lumen reinforcing member, the catheter shaft having a flexible multi-layer coil member, the lumen reinforcing member extending through the coil member, wherein the longitudinal position of the reinforcing member relative to the coil member is adjustable to set the distal end of the reinforcing member when defining the proximal end of the distal flexible segment.

[0016] In some embodiments, the catheter includes a flexion curvature control handle having a handle body and a piston, wherein the piston is coupled to the reinforcing member for longitudinal movement. The piston is adapted to releasably engage the handle body in a plurality of longitudinal configurations when defining corresponding positions where the distal end of the reinforcing member can be set.

[0017] In some embodiments, the catheter includes a pair of pull wires to provide bidirectional flexion curvature of the distal segment of the catheter shaft. In some embodiments, the distal end of the reinforcing member is flat to provide symmetric bidirectional flexion curvature, or alternatively, the distal end of the reinforcing member is non-flat to provide asymmetric bidirectional flexion.

[0018] In some embodiments, opposite segments of the coil member along the diameter are fused or fixed together to provide in-plane flexion. For example, portions of adjacent coils are welded along the diameter of the coil member to facilitate buckling of the coil member in a plane generally perpendicular to the diameter and the welding axis.

[0019] In some embodiments, the catheter includes a catheter shaft having a proximal segment and a distal segment. The catheter has a proximal shaft defining a proximal lumen that extends distally along a longitudinal axis to a distal shaft defining a distal lumen. The distal shaft is offset in a first direction. The catheter has an internal tubular member having a central lumen. The internal tubular member extends through the proximal lumen and the distal lumen. The internal tubular member is configured to translate the distal end portions of the member distally through the proximal lumen and the distal lumen, respectively. The internal tubular member has less flexibility, and the proximal and distal segments have greater flexibility, wherein the distal segment is laterally offset. Longitudinal movement of the internal tubular member relative to the proximal and distal shafts is provided to enable an operator to adjust between various flexion curvatures.

[0020] In a more detailed embodiment, the catheter includes a guide shaft assembly having a proximal segment and a distal segment. The guide shaft assembly has a proximal shaft defining a proximal lumen that extends distally along a longitudinal axis to a distal shaft defining a distal lumen. The distal shaft is offset in a first direction. The guide sheath assembly further includes one or more internal elongate members disposed in one or more side lumens that extend distally from the proximal shaft to the distal shaft. The one or more internal elongate members are attached to a ferrule. The ferrule and the internal elongate members act on the distal segment to selectively vary between various flexion curvatures.

[0021] In a more detailed embodiment, the guide sheath assembly includes a distal shaft having a first helical feature that mates with a second helical feature of the internal tubular member. Rotation of the second helical feature causes the internal tubular member to translate longitudinally distally through the distal shaft to selectively vary between various flexion curvatures.

[0022] In some embodiments, the guide sheath assembly includes a guide sheath that includes a ferrule, a pull wire, a pulley, and an internal tubular member. Simultaneous translation of the internal tubular member and the pull wire selectively varies between various flexion curvatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other features, structures, and advantages of the present invention will be better understood by reference to the following specific embodiments considered in conjunction with the accompanying drawings, in which:

[0024] Figure 1 Top plan view of a catheter of the present invention according to some embodiments.

[0025] Figure 2A Perspective view of a catheter including a catheter shaft, with parts cut away. Figure 1 Perspective view of a catheter including a catheter shaft, with parts cut away.

[0026] Figure 2B Is Figure 2A End sectional view taken along line B - B of the catheter shaft.

[0027] Figure 3 Perspective view of a catheter including a distally flexible segment and a distal end segment of a catheter shaft, with parts cut away. Figure 1 Perspective view of a catheter including a distally flexible segment and a distal end segment of a catheter shaft, with parts cut away.

[0028] Figure 3A Is Figure 3 End sectional view taken along line A - A of the distally flexible segment.

[0029] Figure 3B Is Figure 3 End sectional view taken along line B - B of the distally flexible segment.

[0030] Figure 3C Is Figure 3 End sectional view taken along line C - C of the distally flexible segment.

[0031] Figure 3D Is Figure 3 End sectional view taken along line D - D of the distally flexible segment.

[0032] Figure 4 Is Figure 1 Side sectional view of a flexure curvature adjustment handle.

[0033] Figure 5A 、 Figure 5B And Figure 5C Are schematic diagrams of symmetric bidirectional flexure curvatures of different types or tightness provided by the catheter shaft of Figure 1 Side sectional view of a flexure control handle, with parts cut away.

[0034] Figure 6 Is Figure 1 Top plan view of a flexure control handle, with parts cut away.

[0035] Figure 7 Perspective view of a catheter shaft according to another embodiment of the present invention.

[0036] Figure 8A 、 Figure 8B And Figure 8C Are schematic diagrams of asymmetric bidirectional flexure curvatures of different types or tightness provided by the catheter shaft of Figure 7 Side sectional view of a flexure control handle, with parts cut away.

[0037] Figure 9Perspective view of a catheter shaft according to another embodiment of the present invention.

[0038] Figure 9A Is Figure 9 End cross-sectional view taken along line A-A of the catheter shaft.

[0039] Figure 10 Depicts an exemplary guide sheath assembly that can be used with Figure 1 the catheter in perspective view.

[0040] Figure 11A , Figure 11B and Figure 11C Are cross-sectional views of an exemplary guide shaft assembly that includes reinforcement members at various flexure curvatures for use with Figure 10 the guide sheath assembly, wherein Figure 11A the guide shaft assembly has a flexure curvature that is tighter relative to Figure 11B the flexure curvature; and Figure 11B the flexure curvature of Figure 11C has a tighter flexure curvature relative to

[0041] Figure 12 Shows Figure 11C the end cross-sectional view of the guide shaft assembly taken along line 12-12 of Figure 11C .

[0042] Figure 13 Shows Figure 11C the end cross-sectional view of an exemplary variant of the guide shaft assembly taken along line 12-12 of Figure 11C , the exemplary variant of the guide shaft assembly including a reinforcement member within a side lumen.

[0043] Figure 14A and Figure 14B Are cross-sectional views of yet another exemplary guide shaft assembly that includes a first helical feature and a second helical feature for use with Figure 10 the guide sheath assembly, wherein Figure 14A has a flexure curvature that is tighter relative to Figure 14B .

[0044] Figure 15 Is a schematic view of yet another exemplary guide shaft assembly, wherein the distal segment is in a straight position. Detailed Description

[0045] The following description of certain examples of the present invention is not intended to limit the scope of the present invention. The drawings (not necessarily to scale) illustrate selected embodiments and are not intended to limit the scope of the present invention. The detailed description illustrates the principles of the present invention in an illustrative rather than a restrictive manner. Other examples, features, aspects, embodiments, and advantages of the present invention will be apparent to those skilled in the art from the following description, which is presented by way of example. A best mode is contemplated for practicing the present invention. As will be recognized, the present invention is capable of having other different or equivalent aspects, all of which do not depart from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature rather than restrictive.

[0046] It should be understood that the terms "proximal" and "distal" as used herein are relative to a clinician holding the handpiece assembly. Thus, the end effector is distal relative to the closer handpiece assembly. It should also be understood that, for convenience and clarity, spatial terms such as "axial" and "longitudinal" are also used herein with reference to relative positions and orientations. And rotational direction terms such as "clockwise" and "counterclockwise". However, the surgical instrument is used in many orientations and positions, and these terms are not intended to be restrictive and absolute.

[0047] Any one or more of the teachings, expressions, forms, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, forms, examples, etc. described herein. Accordingly, the following teachings, expressions, forms, examples, etc. should not be regarded as separate from one another. Various suitable ways in which the teachings herein may be combined will be apparent to those skilled in the art in light of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0048] As used herein, the term "about" or "approximately" in reference to any numerical value or range indicates a suitable dimensional tolerance that allows a set of components or elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values ±20% of the recited value, e.g., "about 90%" can refer to a range of values from 71% to 99%. Additionally, as used herein, the terms "patient", "host", "user", and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but the use of the subject invention in human patients represents a preferred embodiment.

[0049] I. Exemplary Catheters with Variable Flexure Curvature

[0050] As Figure 1As shown, the catheter 10 includes an elongate catheter shaft 12, a distal segment 14 having a distal end electrode 15, a flexible rocker handle 16 attached to the proximal end of the catheter shaft 12, and a flexure adjustment handle 18 proximal to the flexible rocker handle 16. According to the features of the present invention, the elongate catheter shaft 12 has an adjustable flexure segment 12D that allows an operator user to change and select between multiple flexure curvatures (e.g., D1, D2, and D3) as needed or desired.

[0051] Referring Figure 2A and Figure 2B , the catheter shaft 12 includes an elongate tubular structure having a single, axial or central lumen 18. The catheter shaft 12 is flexible, i.e., bendable, but substantially non-compressible along its length. The catheter shaft 12 can have any suitable construction and can be made of any suitable material. In some embodiments, the catheter shaft 12 includes an external multi-layer coil member 20 to provide flexibility, torsional stiffness, pushability, and rotational accuracy such that when the rocker handle 16 is rotated, the catheter shaft 12 and the distal segment 14 rotate in a corresponding manner.

[0052] In some embodiments, the multi-layer coil member 20 includes three layers of compression coils 20A, 20B, and 20C, each layer of coil strands or wires having a generally rectangular cross-section, and each layer of coil is wound in a direction different from that of the adjacent layer. For example, the inner coil layer 20A and the outer coil layer 20C have a similar winding direction that is different from the winding direction of the intermediate layer 20B. In Figure 2A the illustrated embodiment, the winding directions of the inner coil layer 20A and the outer layer 20C are on the right side of the Y-axis, and the winding direction of the intermediate layer 20B is generally opposite to the left side of the Y-axis. A suitable multi-layer coil member is available from Heraeus Medical Components, LLC and sold under the trademark TRIFLEX. For example, an outer covering or shrink sleeve 23 of any suitable biocompatible plastic (such as polyurethane or PEBAX) is disposed outside the outer coil layer 20C to protect the catheter shaft 12 and provide a fluid-tight seal interior for the catheter shaft.

[0053] The outer diameter of the catheter shaft 12 is not critical, but is preferably no greater than about 12 French, more preferably about 7.5 French. The inner diameter of the central lumen 22 defined by the inner coil layer 20A is not critical, but is large enough such that the central lumen can accommodate at least an inner reinforcing member 24 that extends through the proximal portion of the catheter shaft 12 and whose distal end 24D defines the proximal end X of the adjustable flexure segment 12D of the catheter shaft 12.

[0054] The reinforcement member 24 is an elongate lumen tubing provided with longitudinal movement relative to the multi-layer coil member 20. The reinforcement member 24 has sufficient flexibility to be maneuverable within the patient's vasculature and also has sufficient stiffness to resist compression and deformation along its length within the central lumen 22 of the coil member 20 such that the flexure segment 12D can flex in response to the one or more pull wires of the catheter 10. The outer diameter of the reinforcement member 24 is less than the inner diameter of the central lumen 22, and the inner diameter of the reinforcement member is large enough such that its central lumen 25 can accommodate various components, such as one or more pull wires, one or more leads, a flush tube, and any other desired wire, cable, or tubing.

[0055] To provide greater flexibility in the distal portion of the multi-layer coil member 20, a smaller number of coils may be used. In the Figure 3 illustrated embodiment, the inner coil layer 20A has a distal end proximal to the distal ends of the intermediate coil layer 20B and the outer coil layer 20C such that the distal portion of 20 has only two coils 20B and 20C instead of three coils. The distal portions of the coil layers 20B and 20C may be welded to form a tubular end portion 21, thereby allowing the pull wire 26 to be attached at the weld point W and locking the two coil layers together.

[0056] As Figure 2B and Figure 3 shown, the components extending through the lumen 25 of the reinforcement member 24 may include a pull wire 26 for bi-directional flexure, a lead 38 for the distal tip electrode 15, a thermocouple wire pair 36, a flush tube 30 for delivering flush fluid to the distal tip electrode 15, a cable 32 for accommodating an electromagnetic (EM) force and position sensor subassembly 41 in the distal segment 14, and a lead 40T for the tip electrode 15 and the 40R annular electrode 17 of the distal segment 14. It should be understood that the catheter 10 may include any configuration of a distal electrode segment, including, for example, a focal tip electrode, a loop electrode assembly, a balloon, or a basket electrode assembly, where these electrodes may be used for diagnostic and / or therapeutic purposes, such as mapping and / or ablation.

[0057] The available length of the catheter shaft 12, i.e., the portion that can be inserted into the body, may vary as needed. Preferably, the available length is in the range of about 100 cm to about 120 cm. The length of the reinforcement member is smaller such that the catheter shaft 12 has a length of about 5 cm to 15 cm distally and has no reinforcement member internally.

[0058] Referring Figure 3 , the distal segment 14 includes a short barrier sleeve 46, a distal tip electrode 15, and a pressure sensing subassembly 41 therebetween. The distal tip electrode 15 is configured with a plurality of flush ports 48 that discharge the flush fluid delivered by the flush tube 30 (see Figure 2B)The delivered fluid, the distal end of the irrigation tube terminates in a chamber in the distal electrode. The pressure sensing subassembly 41 includes an elastic member 50 that elastically deforms in response to a force acting on the distal electrode 15, an internal field generator 42, and three electromagnetic sensing coils 51, S2, S3 that respond to the internal field generator 42 and detect the deformation of the elastic member 50 when determining the force acting on the distal electrode 15. In the illustrated embodiment, the elastic spring member 50 is a tubular member 51 made of an elastically deformable material such as nitinol. The tubular member 51 has a distal portion 51D, a proximal portion 51P, and an intermediate portion with a helical slit 52 that forms the elastic member 50, which allows longitudinal displacement and angular flexure of the distal electrode 15. The electromagnetic sensing coils Sl, S2, and S3 are housed in the central lumen of the proximal portion 51P. A barrier sleeve 46 extends the length of the tubular member between the distal end of the catheter shaft 12 and the distal electrode 15 to provide a fluid-impermeable seal around the tubular member 51. The barrier sleeve can be constructed of any suitable biocompatible material that is flexible and insulating, including CELCON, Teflon, or heat-resistant polyurethane.

[0059] Each of the coils Sl, S2, and S3 is generally parallel to the Z-axis or longitudinal axis 53 of the catheter. They are each positioned at a common longitudinal segment in the tubular member 51, but each is at a different azimuthal angle around the longitudinal axis 53. The coils S1, S2, and S3 are azimuthally spaced 120 degrees apart and are at the same radial distance from the longitudinal axis 53. (See Figure 3D ). The longitudinal displacement and / or angular flexure of the distal portion 51D relative to the proximal portion 51P causes a differential change in the signals output by the coils S1, S2, and S3, which depends on the direction and magnitude of the flexure, since one or both of these coils move relatively closer to the internal field generator 42. A compressive displacement of the distal portion 51D causes an increase in the signal from each of the coils Sl, S2, and S3.

[0060] Also housed in the proximal portion 51D, the sensors Sx and Sy respond to an external field generator (not shown) that generates a magnetic field near the patient's body (e.g., under the patient's bed) to define an external reference frame, as is shown in the art. The coils Sx and Sy are arranged to have axes that are generally orthogonal to each other and have at least one coil, such as S1 (see Figure 3C ). Thus, the coil Sx is aligned with the X-axis, and the coil Sy is aligned with the Y-axis, and both coils are orthogonal to the coil Si, which is aligned with the Z-axis (longitudinal axis 53) in the (X,Y,Z) coordinate system.

[0061] An electromagnetic or magnetic field is generated by external field generators Fx, Fy, and Fz (not shown) and sensed by sensor coils Sx, Sy, and Sz for detecting the position of the catheter. The magnetic field generated by the field generators Fx, Fy, and Fz causes the coils Sx, Sy, and Si to generate electrical signals, the amplitudes of which indicate the position of the distal segment 51D relative to the fixed reference frame of the field generators Fx, Fy, and Fz. In some embodiments, the three field generators Fx, Fy, and Fz generate a magnetic field composed of three field components with different orientations. Each of these field components is sensed by each of the sensor coils Sx, Sy, and Si, and each of these sensor coils generates a signal composed of three components.

[0062] The proximal end of the barrier sleeve 46 and the proximal end of the proximal portion 51P of the tubular member 51 are received in the welded tubular end portion 21 of the multi-layer coil member 20. The distal end of each pull wire 26 is fixedly attached to the inner radial surface of the distal end tubular segment 21. Thus, the distal end of the pull wire is anchored, for example, at or near the distal end of the catheter shaft 12 by a weld point W.

[0063] Components including the lead wires 40T and 40R, the thermocouple wire pair 36, the flush tube 30, and the sensor cable 32 extend through the welded tubular end portion 21 and into the pressure sensing subassembly 41. The sensor cable 32 includes lead wires (not shown) leading to each of the sensors 51, S2, S3, Sx, and Sy.

[0064] To actuate the pull wires 26, the user manipulates the flexure rocker arm 54 on the control handle 16, as Figure 1 shown. As is known in the art, the rocker arm 54 pulls one or the other of the pull wires 26 according to the direction of rotation, which causes the distal segment 12D of the catheter shaft to flex in that direction. According to a feature of the present invention, the type or degree of the flexure curvature of the catheter 10 set by the longitudinal position of the reinforcing member 24 relative to the catheter shaft 12 (and specifically the multi-layer coil member 20) can be adjusted by the operator via the flexure curvature adjustment handle 18.

[0065] In Figure 4 the illustrated embodiment, the flexure curvature adjustment handle 18 includes a generally cylindrical outer body 80 that houses a piston assembly 81. The body 80 has a proximal end 80P and a distal end 80D. The piston assembly 81 includes a piston 84, a longitudinal piston chamber 82 that extends partially therethrough, and a reinforcing channel 83 that extends partially therethrough. The piston chamber 82 extends partially from the proximal end 80P of the outer body 80 into the handle 18 but does not extend beyond the distal end 80D of the outer body. The reinforcing channel 83 having a diameter smaller than the diameter of the piston chamber 82 extends from the distal end of the piston chamber to the distal end 80D of the outer body 80.

[0066] A piston 84 having a proximal end 84P and a distal end 84D is slidably mounted within a piston chamber 82. A proximal fitting 86 is mounted within the proximal end 84P of the piston 84 and is fixedly attached thereto. The proximal fitting 86 includes a tubular distal region 87 that extends distally from the body of the proximal fitting and into the proximal end 84P of the piston. The piston 84 has a longitudinal axial channel 85 that is coaxial with and connected to an axial channel 89 formed in the proximal fitting 86. A reinforcement member 24 has a proximal end 24P that is fixed, such as by an adhesive, to the proximal fitting 86 and is thus coupled to the piston such that movement of the piston causes movement of the reinforcement member 24. The reinforcement member 24 extends through the axial channels 85 and 89 and extends out of the distal end of the flexure curvature adjustment handle 18.

[0067] To guide an operator to select a predetermined type or degree of flexure curvature of the catheter, the adjustment handle 18 is configured for longitudinal movement of the piston 84 relative to the cylindrical body 80 in a measured or discrete manner. In Figure 4 the illustrated embodiment, a plurality of recessed stoppers d1, d2, and d3 are formed longitudinally along the inner radial surface of the piston chamber 82, wherein each stopper is configured to receive and engage a raised formation, such as a ridge or a ball plug 91 supported and biased by a spring 94 located within a recess 92 formed on the outer radial surface of the piston 84 as shown. Each stopper positions the reinforcement member 24 within and relative to the catheter shaft 12 such that the distal end of the reinforcement member 24 generally sets a position Xi that represents the proximal end of the distal flexure segment 12D at which its flexure curvature begins. As Figure 5A , Figure 5B and Figure 5C shown, the positions X1, X2, and X3 enable the distal flexure segment 12D to achieve flexure curvatures D1, D2, and D3, respectively. It should be understood that the drawings (including those showing the stoppers d i and the corresponding positions X i ) are not necessarily drawn to scale relative to each other. It should also be understood that the stoppers may be formed in the outer radial surface of the piston 84, where the raised formations project from the inner radial wall of the piston chamber 82.

[0068] Optionally, a compression spring 88 may be installed within the piston chamber 82 to bias and / or smooth the relative movement of the piston with respect to the cylindrical body 80. The spring 88 may be positioned distally of the distal end 84D of the piston 84 and between the distal ends of the piston chamber 82. The compression spring 88 may be disposed between the piston 84 and the outer body 80, or may have one end in contact with or fixed to the piston 84 and the other end in contact with or fixed to the distal end 80D of the outer body 80.

[0069] The proximal end of the piston 84 has a threaded outer surface 104. A circular thumb controller 106 is rotatably mounted on the threaded outer surface 104 at the proximal end of the piston 84. The thumb controller 106 has a threaded inner surface 108 that interacts with the threaded outer surface 104 of the piston 84 such that the longitudinal position of the thumb controller 106 relative to the proximal end 80P of the outer body 80 is adjustable. The thumb controller 106 serves as a stop to limit the maximum distance that the piston 84 can be pushed distally into the piston chamber 82 and thus limits the distance that the reinforcement member 24 can longitudinally extend distally relative to the catheter shaft 12. A fixing means such as a tension screw 109 is provided in the thumb controller 106 to control the tension between the thumb controller and the piston 84, thereby locking and releasing the longitudinal position of the thumb controller on the proximal end 84P of the piston. As will be appreciated by those skilled in the art, the thumb controller 106 may be replaced by any other mechanism (such as a step on the inner surface 82) that can act as a stop for limiting the distance that the piston 84 extends into the piston chamber 82, and although preferred, the stop is adjustable relative to the piston, but this is not necessary.

[0070] The reinforcement member 24 extends distally from the flexion curvature adjustment handle 18 through the protective shaft 96, which extends between the distal end of the flexion curvature adjustment handle 18 and the proximal end of the flexion rocker handle 16. The reinforcement member 24 extends through the flexion rocker handle 16 and into the proximal end of the catheter shaft 12.

[0071] As Figure 6As shown, the flexure rocker handle portion 16 has a housing 70 and a pulley assembly 72 around which the pull wires 26 are wound to redirect their proximal ends into stops 71 that anchor the proximal ends in the rocker handle portion 16 at a location distal to the pulley assembly 72. Each of the pull wires 26 in the pull wires 26 can be a subassembly including a proximal cord or woven tensile portion that is crimped to the pull wire and wound around the pulley assembly 72. As will be understood by those of ordinary skill in the art, when the operator pivots or "rocks" the pull assembly 72 in one direction via the rocker 54 (see arrow 77), the pull assembly pulls proximally on one of the pull wires on that side for flexure in that direction while releasing the other wire distally to facilitate the flexure. The reinforcement member 24 extends through the length of the housing 70 between the proximal opening 73 and the distal opening 75 and between the pull wires 26. In the illustrated embodiment, longitudinal openings or slots 74 are formed in the sidewalls of the reinforcement member 24 such that the pull wires 26 can enter the lumen 25 of the reinforcement member 24. The slots 74 have a length sufficient to allow the pull wires 26 to enter the lumen 25 while interfering with longitudinal movement of the reinforcement member 24 relative to the catheter shaft 12. It should be understood that the flexure rocker handle portion 16 and the flexure curvature adjustment handle portion 18 can be integral, such as where the aforementioned piston assembly of the handle portion 18 can be incorporated into the flexure rocker handle portion 16 distal to the rocker 54. Suitable flexure control handles are disclosed in U.S. Patents 8,617,087 and 8,747,351, the entire disclosures of which are incorporated herein by reference.

[0072] In use, the operator pulls or pushes the piston 84 of the adjustment handle portion 18 to longitudinally move the piston relative to the outer body 80 from one stop to another as selected by the operator. This movement causes the reinforcement member 24 to longitudinally move within the catheter shaft 12, thereby allowing the operator to change or adjust the distal end of the reinforcement member and thus, when the operator flexes via the flexure rocker 54 on the control handle 16, change or adjust the type of flexure curvature of the distal flexure segment 12D, as Figure 5A , Figure 5B and Figure 5C shown. By engaging the plunger 91 with a more distal stop (e.g., stop d1) in the adjustment handle portion 18, as Figure 4 shown, the piston 84 is set more distally relative to the cylindrical body 80 that positions the distal end of the reinforcement member 24 more distally to provide a smaller or tighter flexure curvature in the distal segment 12D. In contrast, by engaging the plunger 91 with a more proximal stop (e.g., stop d3) in the adjustment handle portion 18, the piston 84 is set more proximally relative to the cylindrical body 80 that positions the distal end of the reinforcement member 24 more proximally to provide a larger or looser flexure curvature in the distal segment 12D.

[0073] According to the features of the present invention, the catheter 10 is provided with in-plane flexure. As Figure 2A and Figure 2B shown, for example, by welding together segments of multiple adjacent coils at 100, portions of the multi-layer coil member 20 are fixed or fused at opposite positions along the first diameter 110 to minimize buckling of the coil member 20 in the first plane defined by the first diameter 110 and the longitudinal axis of the coil member 20, while allowing buckling in a second plane generally perpendicular to the first plane. In the illustrated embodiment, the outer layer 20C has fused portions, but it should be understood that any one or any combination of the layers 20A, 20B, and 20C may have portions fused together and / or fused to each other to achieve biasing or in-plane flexure. In this regard, the pull wire 26 is arranged along a second diameter 112 generally perpendicular to the first diameter 110. In Figure 2A and Figure 2B the embodiment, the coil member 20 is fixed at intermittent welding or fusing positions 100 along its length and along the diameter 110 or X-axis at its outer coil layer 20C, which minimizes buckling of the coil member 20 in the X / Z plane while allowing buckling in the Y / Z plane. In this regard, the pull wire 26 is arranged along the Y-axis generally perpendicular to the X-axis.

[0074] Instead of or in addition to fusing or welding the segments 100, the wire member 101 (shown in dashed lines in Figure 2A ) may be welded or fused to the coil member along its length to limit or provide reduced flexibility of the coil member in one plane.

[0075] In Figure 2A the embodiment, the reinforcement member 24 is shaped to have a flat distal end 24 to provide symmetric bidirectional flexure, as Figure 5A , Figure 5B and Figure 5C shown. The flat distal end sets a common position Xi along the length of the catheter shaft 12 for initiating the flexure curvature (or the proximal end of the distal flexure segment 12D), regardless of which pull wire is pulled for flexure.

[0076] According to the features of the present invention, the reinforcement member 124 according to another embodiment as Figure 7 shown is formed to have non-flat (including, for example, angled, notched, or stepped) distal ends 124D' and 124D" to provide asymmetric bidirectional flexure, as Figure 8A , Figure 8B and Figure 8CAs shown. For each longitudinal position of the reinforcement member 24 relative to the catheter shaft 12, the distal segment 12D has a first flexure curvature Dl' and a second flexure curvature Dl", the first flexure curvature having a first flexure start position Xl' (or the first proximal end of the distal flexure segment 12D) for a pull wire corresponding to the distal end 124D', and the second flexure curvature having a second flexure start position Xl" (or the second proximal end of the distal flexure segment 12D) for another pull wire corresponding to the distal end 124D".

[0077] To ensure that the portion of the reinforcement member 124 extending to the more distal end 24D" has sufficient stiffness to allow it to flex on that side of the reinforcement member 124, the reinforcement member 124 may have a two-part construction including segments 124A and 124B, where the material of segment 124B has sufficient stiffness to support the distal end 124D", preventing excessive buckling or breakage during flexure. For example, segment 124A is constructed of a plastic material, and segment 124B is constructed of nitinol, stainless steel, or other suitable metal.

[0078] In Figure 9 and Figure 9A an alternative embodiment of, the catheter shaft 212 has an outer thin-walled coiled tubular member 220, where a pair of struts 221 are embedded along the diameter of the tubular member 120 or otherwise attached in opposed positions. The struts 221 facilitate bi-directional flexure in a plane generally perpendicular to the diameter. Suitable materials for constructing the struts 221 include, for example, stiffer polymers or metal wires. The internal reinforcement member 124 extending through the lumen 122 of the outer coiled tubular member 120 has a coiled tubular configuration that minimizes the risk of kinking of the reinforcement member.

[0079] II. Exemplary Guide Sheath Assemblies with Variable Flexure Curvature

[0080] In some procedures, the physician may desire to pass the catheter 10 (see Figure 1)Introduced into the patient's body. In some such procedures, the guiding sheath can be inserted into the patient's body (e.g., via the patient's leg or groin); and then advanced along a vein or artery to reach a position in or near the heart. Once the guiding sheath is properly positioned in the patient's body, the physician can advance the end effector 14 and the catheter 10 into the guiding sheath until the end effector 14 exits the distal end of the guiding sheath. Then, the physician can operate the catheter assembly 10 to provide EP mapping, ablation, or any other type of procedure in or near the patient's heart. It may be desirable to manipulate the guiding sheath to facilitate placement of the various catheters 10 in or near the heart. To this end, the guiding sheath assembly can include a guiding shaft assembly that allows the physician to change the flexure curvature near the distal end of the shaft assembly to assist in further navigating the vein or artery to reach a position in or near the heart.

[0081] Figure 10 An example of a guiding sheath assembly 300 that can be used in such procedures is shown. The guiding sheath assembly 300 of this example includes a handle assembly 310 and a guiding shaft assembly 320 that includes a hollow shaft 322 extending distally from the distal end 316 of the handle assembly 310. The handle assembly 310 is configured to be grasped by the housing 312. The open distal end 340 of the hollow shaft 322 is operable to deflect laterally away from the longitudinal axis LA of the shaft 322. This deflection is controlled by a knob 314 at the distal end 316 of the handle assembly 310. The knob 314 can rotate relative to the housing 312 about the longitudinal axis LA, thereby actuating a component that drives the open distal end 340 of the hollow shaft 322 to deflect laterally. By way of example only, and with reference to the teachings herein, such an actuating component can include one or more pull wires, belts, or various suitable structures, which will be apparent to those skilled in the art.

[0082] As Figure 10 shown, a fluid tube 302 extends laterally from the proximal end 318 of the handle assembly 310. The fluid tube 302 of this example is in fluid communication with a hollow interior (not shown) defined within the handle assembly 310; and the hollow interior is in fluid communication with the interior of the hollow shaft 322. The fluid tube 302 of this example is also in fluid communication with a fluid source 304. By way of example only, the fluid source 304 can contain saline or any other suitable fluid. In some cases, the fluid from the fluid source 304 is communicated through the fluid tube 302, the hollow interior region defined within the handle assembly 310, and the interior of the hollow shaft 322 to flush the fluid path defined by the fluid tube 302, the hollow interior region defined within the handle assembly 310, and the interior of the hollow shaft 322.

[0083] As Figure 10As shown, the proximal end 318 of the handle assembly 310 further includes an insertion port 350. The insertion port 350 is aligned with the longitudinal axis LA and provides a port for inserting the end effector 14 and the catheter 10 into the hollow shaft 322. The insertion port 350 of this example includes an annular protrusion 352 that defines an opening 354. The protrusion 352 projects proximally from the housing 312 at the proximal end 318. In some forms, the protrusion 352 is omitted.

[0084] A seal 360 is positioned within the opening 354. By way of example only, and with reference to the teachings herein, the seal 360 may include an elastomeric membrane or other suitable structure, which will be apparent to those skilled in the art. The seal 360 of this example further includes a slit arrangement 362 that is configured to facilitate the insertion of an instrument (e.g., the catheter 10) or an insertion member (not shown) through the seal 360. In this example, the slit arrangement 362 is in the form of a “+” sign, but any other suitable type of configuration may be used. When no substance is inserted through the seal 360, the seal 360 is configured to provide a fluid-impermeable seal that prevents fluid from escaping through the insertion port 350 from a portion of the fluid path defined within the handle assembly 310; and prevents air from entering through the insertion port 350 into the fluid path defined within the handle assembly 310. When an instrument is inserted through the seal 360, the seal 360 still substantially maintains the fluid-impermeable seal of the port 350, thereby preventing fluid from escaping through the insertion port 350 from the fluid path defined within the handle assembly 310; and preventing air from entering through the insertion port 350 into the fluid path defined within the handle assembly 310, while still allowing the inserted instrument to translate relative to the seal 360. Thus, regardless of whether an instrument is disposed in the insertion port 350, the seal 360 can prevent fluid from leaking out through the insertion port 350 and prevent air from being inhaled through the insertion port 350 into the patient's heart.

[0085] A. Exemplary Guide Shaft Assemblies with Variable Reinforcement Members Positioned in Proximal and Distal Lumens

[0086] As described above, it may be desirable to provide a guide shaft assembly within the guide sheath assembly that allows a physician to selectively adjust the flexure curvature of the guide shaft assembly to assist in further navigating the cardiovascular system to a location within or near the heart. Figures 11A - 11C An example of a guide shaft assembly 400 that may be incorporated into the guide sheath assembly 300 is shown. The guide shaft assembly 400 in this example includes a proximal segment 430, a distal segment 440, and a reinforcement member 450. The proximal segment 430 is an elongate tubular member and extends from the handle assembly 310 (see Figure 10) extends distally to the proximal shaft end 459. The proximal segment 430 includes a proximal shaft 432 and a lubricious coating 434. The proximal shaft 432 is sized to fit within a patient's vein or artery. The proximal shaft 432 defines a proximal lumen 436 and may be constructed of a plastic or metal having flexible but rigid characteristics, such as braided stainless steel or nitinol. The lubricious coating 434 is disposed on the outer wall 433 of the proximal shaft. The lubricious coating 434 may be configured to reduce friction between the proximal segment 430 and the patient's vein or artery. The lubricious coating 434 may also be configured to resist the natural lateral biasing of the proximal shaft 432. The proximal segment 430 defines a proximal lumen 436 (see Figure 1 ) configured to receive the catheter 10. The proximal lumen 436 may also be coated with a material configured to reduce friction between the catheter 10 and the proximal lumen 436. With reference to the teachings herein, various suitable coatings will be apparent to those skilled in the art. Alternatively, such coatings may be omitted.

[0087] The distal segment 440 extends distally from the proximal shaft end 459 to a distal tip 448. The distal segment 440 includes a distal shaft 442, a plurality of bands 444, and a distal tip 448. The distal segment 440 is laterally biased into a pre-curved shape away from the longitudinal axis LA. The distal tip 448 is hollow and configured to allow the catheter 10 to pass distally through the distal tip 448. The distal tip 448 may be chamfered or rounded to facilitate physician navigation through the patient's veins and arteries without snagging or kinking on the inner surfaces of the patient's veins and arteries. The distal shaft 442 is sized to be similar to the proximal shaft 432. The distal shaft 442 may be constructed of the same material as the proximal shaft 432. In one example, when the proximal shaft 432 and the distal shaft 442 are constructed of the same material, the proximal shaft 432 ends where the lubricious coating 434 ends and the distal shaft 442 begins at the proximal shaft end 459. In the case where the proximal shaft 432 and the distal shaft 442 are constructed of the same material, the distal shaft 442 may be additionally processed to facilitate the lateral flexed state, such as by heat treatment. Additional processing that is apparent to those skilled in the art may be applied to the distal shaft 442 to impart a lateral bias to the distal shaft 442. As another variant, the distal shaft 442 may be constructed of a material different from the proximal shaft 432. When constructed of dissimilar materials, the proximal shaft end 459 may be operatively connected at the distal end 449 of the proximal segment by welding, brazing, weaving, or otherwise. The distal shaft 442 may be constructed of a shape memory alloy such as nitinol.

[0088] The distal shaft 442 defines a distal lumen 446 that is configured to receive the catheter 10. The distal lumen 446 is sized similarly to the proximal lumen 436 and is configured to allow the catheter 10 to easily transition from the proximal lumen 436 to the distal lumen 446. The distal shaft 442 may also have a lubricious coating 434 that is configured to facilitate sliding of the distal shaft 442 within a patient's vein or artery. As shown, the lubricious coating 434 may be located on the distal portion 460 of the distal segment 440 (e.g., only on the distal tip 448) or may be located along any length of the outer wall 443 of the distal shaft. The coating on the distal portion 460 may resist lateral deflection of the distal segment 440 and straighten the distal portion 460. The distal lumen 446 may also have a lubricious coating 434 that is configured to facilitate translation of the catheter 10 and / or the reinforcement member 450 within the distal lumen 446.

[0089] A plurality of bands 444 are positioned along the length of the distal shaft 442. The plurality of bands 444 may be constructed of a rigid, surgically safe plastic or metal such as stainless steel. By way of example only, and with reference to the teachings herein, the plurality of bands 444 may include one or more rings, surface effectors, or various suitable support structures, which will be apparent to those skilled in the art. The plurality of bands 444 are configured to provide support to the distal shaft 442 and may provide tactile feedback to a user as the distal segment 440 translates along a patient's vein or artery. The tactile feedback may assist the user in understanding the position of the distal segment 440. In some configurations, one or more of the bands 444 function as electrodes. For example, one or more of the bands 444 may be operable to provide EP mapping by picking up electrical potentials from tissue contact with the band.

[0090] The plurality of bands 444 shown in the current example are spaced equidistantly from each other along the length of the distal shaft 442. A first band 444 is positioned distal to the proximal end of the distal shaft 442, a second band 444 is positioned distal to the first band 444, a third band 444 is positioned distal to the second band 444, and a fourth band 444 is positioned distal to the third band 444 and proximal to the distal tip 448. By way of example only, the bands 444 may be positioned to gradually move closer to each other near the distal tip 448 or to gradually move closer to each other near the proximal shaft end 459. In the current example, there are four bands 444. By way of example only, there may be no bands 444, two bands 444, six bands 444, eight bands 444, or any number of bands 444 may be used to provide support and tactile feedback. The bands 444 may be positioned within the distal lumen 446. In an example where the bands 444 are within the distal lumen 446, the bands 444 are configured to provide support to the distal segment 440 and provide tactile feedback to the user of the position of the reinforcement member 450.

[0091] The reinforcement member 450 is constructed of a rigid yet flexible material such as metal or plastic. One such exemplary material is polytetrafluoroethylene (PTFE). The reinforcement member 450 is sized to fit within both the proximal lumen 436 and the distal lumen 446. The reinforcement member 450 defines a member lumen 456 sized to slidably receive the catheter 10. The reinforcement member 450 has a stiffer characteristic (e.g., lateral stiffness) relative to the distal shaft 442. The reinforcement member 450 is configured to selectively translate distally within the proximal lumen 436 and the distal lumen 446. The reinforcement member 450 is configured to counteract the lateral bias of the distal shaft 442. The reinforcement member 450 counteracts the lateral bias of the distal shaft 442 and thereby provides a variable flexure curvature DCx (i.e., radius of curvature) in the distal shaft 442, where the flexure curvature DC x is based on the longitudinal position of the reinforcement member 450 within the distal shaft 442. The portion of the distal shaft 442 positioned distally relative to the reinforcement member end 454 maintains its laterally biased flexure and produces a tighter flexure curvature DCx relative to the relatively straighter portion of the distal shaft 442 located between the reinforcement member end 454 and the proximal shaft end 459. The width of the flexure curvature DCx is the lateral distance from the longitudinal axis LA to the centerline axis of the distal tip 448; and serves as a reference for identifying variations between the various flexure curvatures DCx.

[0092] Although in this example the distal shaft 442 is elastically biased to provide a 180-degree retrograde flexure angle such that the centerline axis of the distal tip 448 is parallel to the longitudinal axis LA, other variations of the distal shaft 442 may have an elastic bias that provides an angled flexure angle such that the centerline axis of the distal tip 448 is angled relative to the longitudinal axis LA.

[0093] To control the flexure curvature DCx in this example, the reinforcement member 450 can be manually inserted distally through the insertion port 350 ( Figure 10 ), further through the proximal lumen, and further through the distal lumen 446. As another merely illustrative example, the reinforcement member 450 can be integrated into the guide shaft assembly 320; the handle assembly 310 having a movable actuator (e.g., slider, etc.) that is operable to selectively translate the reinforcement member 450 within the distal lumen 446. In either case, the reinforcement member 450 is inserted to an insertion depth IDx. The insertion depth IDx is the distance from the proximal shaft end 459 to the reinforcement member end 454. The insertion depth IDx is inversely related to the flexure curvature DCx width. A relatively long insertion depth IDx results in a relatively small flexure curvature DCx width.

[0094] Figure 11A The reinforcement member 450 inserted to the insertion depth ID1 is shown. Figure 11BShows the reinforcing member 450 inserted to the insertion depth ID2. Figure 11C Shows the reinforcing member 450 inserted to the insertion depth ID3. The insertion depth ID1 is relatively longer than Figure 11B the shown insertion depth ID2. The insertion depth ID2 is relatively shorter than the insertion depth ID1 but longer than the insertion depth ID3. The insertion depth ID3 is relatively shorter than the insertion depth ID2. Thus, the flexure curvature DC1 is relatively tighter than Figure 11B the shown flexure curvature DC2; the flexure curvature DC2 is looser than the flexure curvature DC1 and tighter than the flexure curvature DC3; and the flexure curvature DC3 is relatively looser than the flexure curvature DC2. By way of example only, the width of the flexure curvature DC1 may be about 20 mm; the width of the flexure curvature DC2 may be about 32 mm; and the width of the flexure curvature DC3 may be about 55 mm. Alternatively, any other suitable flexure curvature DCx may be provided.

[0095] It should also be understood that any suitable number of different flexure curvatures DCx may be achieved by further varying the insertion depth IDx of the reinforcing member 450. An infinite range or a finite number of flexure curvatures DCx may be produced. The three insertion depths IDx and the corresponding flexure curvatures DCx are shown and described herein only as illustrative examples. By way of further example only, the width of the flexure curvature DCx may vary in the range of about 0 mm to about 75 mm. In some examples, the width of the flexure curvature DCx may vary in the range of about 0 mm to about 75 mm; and more specifically in the range of about 20 mm to about 55 mm.

[0096] Figure 12Shows the guide shaft assembly 400 of 11C taken along line 12-12. A lubricating coating 434 is shown on the proximal outer shaft wall 433 of the proximal shaft 432. A reinforcing member 450 is disposed within the proximal lumen 436. The catheter 10 is disposed within the member lumen 456. The proximal shaft 432 and the distal shaft 442 may also include at least one side lumen 464 that is configured to receive at least one pull wire, a reinforcing member, or some other element. The at least one side lumen 464 may communicate with the proximal lumen 436 and the distal lumen 446, as shown. The at least one side lumen 464 may be defined by the proximal shaft 432 and the distal shaft 442 in a hollow region that extends distally parallel to the longitudinal axis within the proximal lumen 436 and the proximal outer shaft wall 433. In other examples, the guide shaft assembly (400) may include at least one pull wire. By way of example only, the proximal shaft 432 and the distal shaft 442 may include four, six, or eight pull wires within four, six, or eight corresponding side lumens 464. The at least one side lumen 464 and the at least one pull wire may be radially positioned around the proximal lumen 436 and the distal lumen 446. Examples of pull wires will be described in more detail below. In some forms of the guide shaft assembly 400, the side lumen 464 is simply omitted such that the guide shaft assembly 400 lacks the side lumen 464.

[0097] B. Exemplary Guide Shaft Assemblies with Variable Reinforcement Members in Lateral Lumens

[0098] As described above, it may be desirable to provide a guide shaft assembly in a guide sheath assembly that allows a physician to selectively adjust the flexure curvature of the guide shaft assembly to assist in further navigating the cardiovascular system to a location within or near the heart. It may also be desirable to provide a guide shaft assembly that includes all such functions while minimizing the amount of space occupied within the proximal lumen and the distal lumen, thereby further facilitating the introduction of a catheter through such proximal and distal lumens.

[0099] Figure 13 Another example of a guide shaft assembly 500 similar to the guide shaft assembly 400 is shown. Figure 13 The view of the guide shaft assembly 500 in is similar to Figure 12 the view of the guide shaft assembly 400 in. The guide shaft assembly 500 in this example has a proximal segment 530 that is different from the proximal segment 430; and a distal segment (not shown) that is similar to the distal segment 440. The proximal segment 530 includes a proximal shaft 532. The distal segment of the guide shaft assembly 500 has a distal shaft that is similar to the distal shaft 442 of the guide shaft assembly 400. The proximal shaft 532 and the distal shaft define a proximal lumen 536 and a distal lumen (not shown), respectively. The proximal shaft may include a lubricating coating 534 on the proximal shaft outer wall 533. The guide shaft assembly 500 may optionally include a plurality of bands, such as the plurality of bands 444 of the guide shaft assembly 400.

[0100] The guiding shaft assembly 500 differs from the guiding shaft assembly 400 in that the strengthening member 550 is disposed within the one or more side lumens 564. Additionally, unlike the guiding shaft assembly 400, the guiding shaft assembly 500 in this example includes a ferrule 562. The ferrule 562 is positioned proximal to the distal end 448. The strengthening member 550 is operatively attached to the ferrule 562 at the strengthening member end 554. By way of example only, the strengthening member 550 may be attached to the ferrule 562 by brazing, welding, or gluing. The ferrule 562 is configured to transfer the stiffness of the strengthening member 550 to the distal lumen 446 (see Figures 11A - 11C ).

[0101] The strengthening member 550 is a rigid elongate member that may have a cross-sectional shape of a circle, triangle, square, rectangle, or any other suitable shape. The strengthening member 550 is configured to translate through the one or more side lumens 564. The side lumen 564 may also have a cross-sectional void that is circular, triangular, square, rectangular, or any other suitable shape to permit translation of the strengthening member 550. The shape of the strengthening member 550 may be the same as or different from the shape of the void of the one or more side lumens 564. The strengthening member 550 may be solid or hollow. Although Figure 13 two strengthening members 550 are shown, the guiding shaft assembly 500 may alternatively have only one strengthening member 550; or more than two strengthening members 550.

[0102] When the strengthening member 550 is selectively translated distally within the guiding shaft assembly 500, the strengthening member 550 counteracts the lateral offset of the distal segment, thereby changing the flexion curvature DCx, similar to the Figures 11A - 11C sequence of operations shown. An actuator may be operatively coupled to the strengthening member 550 to linearly translate the strengthening member 550, as described below. In other examples, the strengthening member 550 may be manually inserted through the one or more side lumens 564. The combination of the stiffness of the ferrule 562 and the strengthening member 550 provides a combined stiffness similar to that of the strengthening member 450 of the guiding shaft assembly 400. When the ferrule 562 is inserted to an insertion depth (e.g., the insertion depth IDx as shown in Figures 11A - 11C ), the combined stiffness counteracts the lateral offset of the distal shaft), thereby changing the flexion curvature (e.g., the flexion curvature DCx as shown in Figures 11A - 11C ). Similar to the guiding shaft assembly 400, the insertion depth ID x associated with the guiding shaft assembly 500 is negatively correlated with the flexion curvature DCx.

[0103] C. A. Exemplary Guide Shaft Assemblies with First and Second Helical Features for Adjusting Flexure Curvature

[0104] Figures 14A - 14B FIG. 2 shows another example of a guide shaft assembly 600, which is similar to the guide shaft assembly 400 except for the differences noted below. The guide shaft assembly 600 in this example includes a proximal segment 630, a distal segment 640, and a reinforcement member 650. The proximal segment 630 includes a proximal shaft 632 that defines a proximal lumen 636. The proximal segment 630 may also include a lubricating coating 634. The lubricating coating 634 may be located on the proximal lumen 636 or elsewhere. The distal segment 640 includes a distal shaft 642 that defines a distal lumen 646, a band 644, and a distal portion 660 having an open distal end 648.

[0105] The distal segment 640 of the guide shaft assembly 600 is similar to the distal segment 440 of the guide shaft assembly 400 in that the distal segment 640 is elastically biased to laterally deviate from the longitudinal axis LA; and the reinforcement member 650 is advanced distally to increase the insertion depth IDx, which counteracts this lateral bias, resulting in a smaller deflection curvature DCx. Similar to the guide shaft assembly 400, the insertion depth IDx of the reinforcement member 650 is the distance from the proximal segment end 659 to the reinforcement member end 654; and the deflection curvature DCx is the distance from the longitudinal axis LA to the center of the distal portion 660. The distal portion 660 may also have a lubricating coating 634 similar to that of the guide shaft assembly 400.

[0106] The guide shaft assembly 600 differs from the guide sheath assembly 400 in that the reinforcement member 650 translates proximally and distally by rotational movement of the reinforcement member 650. The proximal shaft 632 and the distal shaft 642 include a first helical feature 662. The first helical feature 662 mates with a second helical feature 664 on the reinforcement member 650. The first helical feature 662 may be an internal thread, and the second helical feature 664 may be an external thread, or vice versa. The first helical feature 662 and the second helical feature 664 may be right-handed helical features that translate the reinforcement member 650 distally using a clockwise rotation or left-handed helical features that translate the reinforcement member 650 distally using a counterclockwise rotation. In some other configurations, the helical features 662, 664 may be formed as a first helical coil structure and a second helical coil structure, respectively, rather than in the form of complementary internal and external threads. In this type of configuration, the first helical coil and the second helical coil may be slidably interlocked with each other to form a mating arrangement having similar inner and outer diameters. Such helical structures may be formed from laser-cut tubing forming the shafts 632, 642, and the reinforcement member 650; or in any other suitable manner.

[0107] Figure 14A is shown relative to Figure 14BThe insertion depth ID5 shown has a guide shaft assembly 600 with a longer insertion depth ID4; and a flexure curvature DC4 that is tighter relative to the Figure 14B flexure curvature DC5 shown. The reinforcement member 650 can be actuated by an actuator (e.g., a knob, a rotary dial, a slider, etc.) positioned on the handle assembly 310; or can be directly rotated by the user's hand through the insertion port 350 until the second helical feature 664 mates with the first helical feature 662. After the second helical feature 664 mates with the first helical feature 662, the reinforcement member 650 or the actuator rotates the reinforcement member 650 in a clockwise direction so as to translate the reinforcement member 650 distally. Referring to the teachings herein, the spacing between the first helical feature 662 and the second helical feature 664 can be any suitable spacing, which will be apparent to those skilled in the art.

[0108] Figure 14B There is shown Figure 14A a guide shaft assembly 600 in which the reinforcement member 650 rotates counterclockwise. The helical features 662, 664 have engaged with each other and cause the reinforcement member 650 to transition in the proximal direction, thereby reducing the insertion depth ID5 relative to the insertion depth ID4 (see Figure 14A ), thereby loosening the flexure curvature DC5 relative to the flexure curvature DC4. (See Figure 14A ).

[0109] D. Exemplary Guide Shafts with Reinforcement Members and Pull Wires for Adjusting Flexure Curvature

[0110] Figure 15 There is shown another example of a guide shaft assembly 700 in a straight position. The guide shaft assembly 700 in this example is similar to the guide shaft assembly 400 except for the differences noted below. The guide shaft assembly 700 includes a proximal segment 730, a distal segment 740, and a reinforcement member 750. The proximal segment 730 has a proximal shaft 732, a pair of side lumens 764, and a proximal lumen 736. The distal segment 740 includes a distal shaft 742, a distal lumen 746, the pair of side lumens 764, and a distal end 748. The distal segment may additionally include a plurality of bands 444 similar to those of the guide shaft assembly 400; and a lubricating coating 434 similar to the lubricating coating of the guide shaft assembly 400. The reinforcement member 750 extends distally from the proximal member end 752 through one of the side lumens 764 to the distal member end 754.

[0111] The distal segment 740 of the guide shaft assembly 700 differs from the distal segment 440 of the guide shaft assembly 400 in that the distal segment 740 is not elastically biased toward a pre-bent shape. The distal segment 740 of this example may be constructed of a malleable but rigid material such as plastic or a surgically safe metal such as braided stainless steel. In some forms, the distal segment 740 may be elastically biased to present a straight configuration such that the distal segment 740 is elastically biased toward the longitudinal axis LA. The guide shaft assembly 700 also differs from the guide shaft assembly 400 in that the guide shaft assembly 700 includes a ferrule 762, a pull wire 770, and a pulley 780.

[0112] The ferrule 762 in this example is in the form of an annular loop operably connected to the pull wire 770 and is configured to act upon by a proximal force applied by the pull wire 770. The ferrule 762 may be constructed of rigid plastic or a surgically safe metal. The ferrule 762 is positioned proximal to the distal end 748. The pull wire 770 includes a first wire end 772 and a second wire end 774. The pull wire 770 is constructed of a wire, a polymer fiber, or any other suitable material; and is configured to apply tension to the ferrule 762. The pull wire 770 is attached to the ferrule 762 at the first wire end 772 by gluing, welding, soldering, brazing, or any other suitable technique. The pull wire 770 extends proximally from the ferrule 762 through the first side lumen 764 along a first offset axis OA1. The first offset axis OA1 extends parallel to the longitudinal axis LA.

[0113] A portion of the pull wire 770 is wound around the pulley 780. The pulley 780 is positioned within the handle assembly 310 and may include a bearing 782. The bearing may have steel needles, ball bearings, or brass bushings or various suitable structures that reduce rotational friction, which will be apparent to those skilled in the art. The pulley 780 may also be fixedly attached to the handle assembly 310 (see Figure 10 ) and remains statically positioned. The pulley 780 may be lubricated or coated to reduce the friction between the pull wire 770 and the pulley 780. The pulley 780 is configured to change the direction of the force applied to the pull wire 770. The pull wire 770 further extends distally from the periphery of the pulley 780 into the second side lumen 764 disposed along a second offset axis OA2. The second offset axis OA2 is parallel to the longitudinal axis LA on the side opposite the first offset axis OA1. The pull wire 770 is operably attached to the proximal end of the actuator 790 at the second wire end 774.

[0114] Actuator 790 is positioned within the handle assembly 310 and near the second offset axis OA2. The actuator is operatively coupled to the proximal member end 752. The actuator may include buttons, gears, threads, cam surfaces, sliders, or other various suitable structures for translating a rigid body and a tensioning device that will be apparent to those skilled in the art. Actuator 790 may also include a stop feature (not shown) configured to hold the guide shaft assembly 700 in a desired position and an indicator 792 configured to provide haptic or visual feedback of the desired position. Indicator 792 may indicate the insertion depth (e.g., similar to Figures 11A - 11C the insertion depth IDx shown) or the deflection curvature (e.g., similar to Figures 11A - 11C the deflection curvature DCx shown). Actuator 790 may use rotational, lateral, or longitudinal movement to simultaneously translate the reinforcement member 750 and the pull wire 770 along the second offset axis OA2. The reinforcement member 750 extends distally from the proximal member end 752 through a second side lumen (e.g., similar to Figure 12 the second side lumen 464 shown) to the distal member end 754. In some examples, the reinforcement member 750 may be disposed within the proximal lumen 736 and the distal lumen 746.

[0115] In the straight position, the distal member end 754 is in the most proximal position, and the first wire end 772 is in the most distal position. The reinforcement member 750 elastically biases the portion of the distal segment 740 that includes the reinforcement member 750 to the straight position and aligns the distal segment 740 with the longitudinal axis LA.

[0116] During operation, the guide shaft assembly 700 may transition from the straight position to a first flexed position (not shown) having a minimum flexure curvature similar to Figure 11A the flexure curvature DC1 shown; and further transition to a second flexed position (not shown) having a maximum flexure curvature similar to Figure 11C the flexure curvature DC3 shown. The guide shaft assembly 700 transitions to the first flexed position by the user's thumb or finger acting on the actuator 790. The user's thumb or finger acts on the actuator 790 by rotating, pressing, or translating the actuator 790. Actuator 790 translates the reinforcement member 750 distally along the second offset axis OA2 and simultaneously translates the second wire end 774 distally along the second offset axis OA2.

[0117] The second wire end 774 translates distally and translates the portion of the traction wire 770 positioned on the periphery of the pulley 780. The pulley 780 rotates about the bearing 782 and converts the distal force applied to the second wire end 774 by the actuator 790 into a proximal force that translates the first wire end 772 proximally. The first wire end 772 translates the grommet 762 proximally, thereby causing the distal shaft 742 to transition from a straight position to a first flexed position having a minimum flexure curvature similar to Figure 11A the flexure curvature DC1 shown. The minimum flexure curvature of this stage has a shorter width relative to the maximum flexure curvature, which is similar in that the portion of the distal segment 740 that does not include the reinforcement member 750 flexes sharply relative to the maximum flexure curvature. The proximal force exerted on the grommet 762 greatly overcomes the straight bias of the portion of the distal segment 740 positioned distal to the distal member end 754.

[0118] The first flexed position transitions to a second flexed position by further action of the user's finger or thumb on the actuator 790. The second flexed position has a maximum flexure curvature similar to Figure 11C the flexure curvature DC3 shown. The actuator 790 also translates the reinforcement member 750 distally while causing the first wire end 772 to transition proximally via the pulley 780. The first wire end 772 further translates the grommet 762 proximally. The proximal force exerted on the grommet 762 in combination with the more distal distal member end 754 results in a maximum flexure curvature that corresponds to the force exerted by the reinforcement member 750 and the proximal force exerted on the grommet 762. The maximum flexure curvature is relatively wider than the minimum flexure curvature.

[0119] The actuator 790 can have an infinite or finite number of positions between the first flexed position and the second flexed position. By way of example only, an actuator 790 having a finite number of positions can have a first flexed position, a second flexed position, and a third flexed position. The stopper can hold the guide shaft assembly 700 and the indicator 792 in the corresponding positions and can give a tactile or visual indication of the corresponding positions.

[0120] Although the actuator 790 is described in the context of the other elements shown in Figure 15 the actuator, such as the actuator 790, can be used to selectively drive the translation of any of the above-described reinforcement members 450, 550, 650. By way of further example only, referring to the teachings herein, an actuator such as the actuator 790 can include one or more levers, sliders, threads, buttons, gears, motors, wires, pulleys, or any other suitable structure, which will be apparent to those skilled in the art.

[0121] III. Exemplary Combinations

[0122] The following embodiments relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following embodiments are not intended to limit the scope of any claims that may be provided at any time in the present patent application or in subsequent filings of the present patent application. There is no intention to disclaim. The following embodiments are provided merely for illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in many other ways. It is also contemplated that some variations may omit certain features mentioned in the following embodiments. Accordingly, none of the aspects or features mentioned below should be considered decisive, unless otherwise expressly so indicated, for example, by the inventor or successors in interest to the inventor, at a later date. If any claims presented in the present patent application or in subsequent filings related to the present patent application include additional features other than those mentioned below, such additional features should not be assumed to have been added for any reason related to patentability.

[0123] Example 1

[0124] An axial assembly includes: (a) a proximal segment that extends distally along a longitudinal axis, the proximal segment including a proximal shaft that defines a proximal lumen; (b) a distal segment that extends distally from the proximal segment, the distal segment including a distal shaft that defines a distal lumen configured to be aligned with the proximal lumen, the distal segment being configured to be biased to laterally flex away from the longitudinal axis into a flexure curvature having a width, the distal segment being configured to fit within a cardiovascular anatomical passage; and (c) at least one reinforcement member configured to selectively translate along the longitudinal axis, the at least one reinforcement member being configured to counteract the lateral bias of the distal segment and thereby reduce the width of the flexure curvature based on the longitudinal position of the reinforcement member relative to the distal segment.

[0125] Example 2

[0126] The axial assembly according to Embodiment 1, wherein the at least one reinforcement member is disposed within the proximal lumen and is capable of selectively translating through the distal lumen.

[0127] Example 3

[0128] The axial assembly according to any one or more of Embodiments 1 to 2, wherein the width of the flexure curvature is in the range of approximately 0 mm to approximately 55 mm.

[0129] Example 4

[0130] The shaft assembly according to Embodiment 3, wherein the width of the flexure curvature is in the range of approximately 20 mm to approximately 55 mm.

[0131] Example 5

[0132] The shaft assembly according to any one or more of Embodiments 1 to 4, wherein the at least one strengthening member is disposed in one or more side lumens formed in one of the proximal segment and the distal segment.

[0133] Example 6

[0134] The shaft assembly according to any one or more of Embodiments 1 to 5, further comprising one or more pull wires operable to control lateral flexure of the distal segment.

[0135] Example 7

[0136] The shaft assembly according to any one or more of Embodiments 1 to 6, further comprising an actuator configured to selectively flex the distal segment.

[0137] Example 8

[0138] The shaft assembly according to Embodiment 7, wherein the actuator is operable to linearly translate so as to linearly translate the at least one strengthening member.

[0139] Example 9

[0140] The shaft assembly according to any one or more of Embodiments 7 to 8, wherein the actuator is rotatable to linearly translate the at least one strengthening member.

[0141] Example 10

[0142] The shaft assembly according to any one or more of Embodiments 1 to 9, further comprising a collar operable to control lateral flexure of the distal segment.

[0143] Example 11

[0144] The shaft assembly according to Embodiment 10, wherein the collar is attached to the at least one strengthening member.

[0145] Example 12

[0146] The shaft assembly according to any one or more of Embodiments 10 to 11, further comprising one or more pull wires operable to control lateral flexure of the distal segment, the collar being attached to the one or more pull wires.

[0147] Example 13

[0148] The shaft assembly according to any one or more of Embodiments 1 to 12 further includes: (a) one or more pull wires that are operable to control lateral flexion of the distal segment; and (b) a pulley, to which the one or more pull wires engage, the pulley being configured to change the direction of the force applied to the one or more pull wires.

[0149] Example 14

[0150] The shaft assembly according to Embodiment 13 further includes a washer that is operable to control lateral flexion of the distal segment, the washer being proximal to the distal end of the proximal shaft, and the washer being attached to the one or more pull wires extending along a first axis parallel to the longitudinal axis, a portion of the one or more pull wires being wound around the pulley, the one or more pull wires being operable to translate through a second axis that is opposite and parallel to the first axis and is positioned along the longitudinal axis, the one or more pull wires extending distally along the second axis and being attached to an actuator, and the actuator being attached to the reinforcement member that extends distally along the second axis.

[0151] Example 15

[0152] A sheath assembly includes: (a) the shaft assembly according to any one or more of Embodiments 1 to 14, the proximal lumen and the distal lumen being sized to slidably receive a catheter; and (b) a handle assembly including a proximal opening configured to receive the catheter, the shaft assembly extending distally from the handle assembly, the proximal opening being in communication with the proximal lumen and the distal lumen.

[0153] Example 16

[0154] A shaft assembly includes: (a) a proximal shaft that extends distally along a longitudinal axis and defines a proximal lumen; (b) a distal shaft that is elastically biased to laterally flex away from the longitudinal axis, the distal shaft including a first helical feature that extends distally and defines a distal lumen; and (c) one or more reinforcement members including a second helical feature configured to mate with the first helical feature, the reinforcement members being selectively translatable along the longitudinal axis by rotating the one or more reinforcement members to reduce the flexure curvature defined by the distal shaft.

[0155] Example 17

[0156] The shaft assembly according to Embodiment 16, wherein the first helical feature and the second helical feature include complementary interlocking helical coils.

[0157] Example 18

[0158] A shaft comprising: (a) an elongate shaft extending distally along a longitudinal axis to a distal end, the elongate shaft defining an elongate lumen; (b) a reinforcement member having a proximal end extending distally through the elongate shaft to a distal end, the reinforcement member being configured to urge the elongate shaft toward the longitudinal axis; (c) a ferrule near the distal end; (d) a pull wire having a first end and a second end, the first end being attached to the ferrule on a first axis parallel to the longitudinal axis, and the second end being positioned along a second axis opposite the first axis; (e) a pulley configured to engage a portion of the pull wire between the first end and the second end; and (f) an actuator attached to the second end of the pull wire and the proximal end of the reinforcement member, the actuator being operable to simultaneously translate the reinforcement member and the second end distally along the second axis, the pulley being configured to change a distal force acting on the second end to a proximal force at the first end, the ferrule being configured to translate proximally along the first axis, and the reinforcement member being configured to translate distally a width of a flexure curvature.

[0159] Example 19

[0160] The shaft assembly according to Embodiment 18, wherein the reinforcement member is disposed within one or more side lumens formed in the elongate shaft.

[0161] Example 20

[0162] The shaft assembly according to Embodiment 19, wherein the pull wire is disposed within the one or more side lumens.

[0163] IV. Miscellaneous

[0164] It should be understood that any example described herein may also include various other features in addition to or instead of those described above. By way of example only, any example described herein may also include one or more of the various features disclosed in any one of the various references incorporated herein by reference.

[0165] It should be understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein can be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. described herein. Accordingly, the foregoing teachings, expressions, embodiments, examples, etc. should not be regarded as mutually exclusive. With reference to the teachings of this application, various suitable ways in which the teachings of this application can be combined will be apparent to those skilled in the art. Such modifications and variations are intended to be included within the scope of the claims.

[0166] It should be understood that any patent, patent publication, or other publicly available material that is alleged to be incorporated by reference herein, whether in whole or in part, is incorporated herein only to the extent that such incorporated material does not conflict with the existing definitions, statements, or other publicly available material set forth in this disclosure. Accordingly, and to the extent necessary, the disclosure set forth herein supersedes any conflicting material incorporated by reference herein. Any material or portion thereof that is alleged to be incorporated by reference herein and that conflicts with the existing definitions, statements, or other publicly available material set forth herein will be incorporated only to the extent that there is no conflict between the incorporated material and the existing publicly available material.

[0167] The forms of the devices disclosed herein can be designed to be discarded after a single use or can be designed for multiple uses. In either case or both cases, these forms can be repaired for reuse after at least one use. Repair can include any combination of the following steps: disassembling the device, then cleaning or replacing specific parts and subsequently reassembling. Specifically, the form of the device can be disassembled, and any number of specific components or parts of the device can be replaced or removed selectively in any combination. When cleaning and / or replacing specific parts, the form of the device can be reassembled in a repair facility for subsequent use or can be reassembled by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that the repair of the device can be carried out using a variety of techniques for disassembly, cleaning / replacement, and reassembly. The use of such techniques and the resulting repaired device are within the scope of this application.

[0168] By way of example only, the patterns described herein may be processed prior to a surgical procedure. First, new or used instruments may be obtained and cleaned as needed. Then, the instruments may be sterilized. In one sterilization technique, the instruments are placed in a closed and sealed container (such as a plastic or TYVEK bag). The container and instruments may then be placed in a radiation field that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. Radiation may kill bacteria on the instruments and in the container. The sterilized instruments may then be stored in a sterile container. The sealed container may keep the instruments sterile until the container is opened in a surgical facility. Any other technique known in the art may also be used to sterilize the device, including but not limited to beta radiation or gamma radiation, ethylene oxide, or steam.

[0169] While various versions of the invention have been shown and described, further improvements to the methods and systems described herein may be achieved by appropriate modifications by those skilled in the art without departing from the scope of the invention. Several such possible modifications have been mentioned, and other modifications will be apparent to those skilled in the art. For example, the examples, versions, geometries, materials, dimensions, ratios, steps, etc. discussed above are exemplary and not required. Therefore, the scope of the invention should be considered in light of the following claims and should be understood not to be limited to the details of the structure and operation shown and described in the specification and drawings.

Claims

1. An axle assembly, comprising: (a) a proximal segment that extends distally along a longitudinal axis, the proximal segment including a proximal shaft that defines a proximal lumen; (b) a distal segment that extends distally from the proximal segment, the distal segment including a distal shaft that defines a distal lumen configured to be aligned with the proximal lumen, the distal segment being configured to be biased to laterally flex away from the longitudinal axis into a flexure curve having a width, the distal segment being configured to fit within a cardiovascular anatomical passage; (c) at least one reinforcing member disposed within a side lumen of the axle assembly and configured to selectively translate along the longitudinal axis, the at least one reinforcing member being configured to counteract the lateral bias of the distal segment and thereby reduce the width of the flexure curve based on the longitudinal position of the reinforcing member relative to the distal segment; and (d) a ferrule located in the proximal lumen or the distal lumen, the at least one reinforcing member being operatively attached to the ferrule at an end of the at least one reinforcing member, wherein the ferrule is configured to translate when the at least one reinforcing member translates along the longitudinal axis and transfer the stiffness of the at least one reinforcing member to the distal lumen to control the lateral flexure of the distal segment.

2. The shaft assembly according to claim 1, characterized in that, The width of the flexure curve is in the range of 0 mm to 55 mm.

3. The shaft assembly according to claim 2, characterized in that, The width of the flexure curve is in the range of 20 mm to 55 mm.

4. The shaft assembly according to claim 1, characterized in that, Further comprising one or more pull wires operable to control the lateral flexure of the distal segment.

5. The shaft assembly according to claim 1, wherein Further comprising an actuator configured to selectively flex the distal segment.

6. The shaft assembly according to claim 5, wherein, The actuator is operable to linearly translate to linearly translate the at least one reinforcing member.

7. The shaft assembly according to claim 5, characterized in that, The actuator is operable to rotate to linearly translate the at least one reinforcing member.

8. The shaft assembly according to claim 1, characterized in that, Further comprising one or more pull wires operable to control the lateral flexure of the distal segment, the ferrule being attached to the one or more pull wires.

9. The shaft assembly according to claim 1, wherein, Further comprising: (a) one or more pull wires operable to control the lateral flexure of the distal segment; and (b) a pulley, the one or more pull wires engaging the pulley, the pulley being configured to change the direction of the force applied to the one or more pull wires.

10. The shaft assembly according to claim 9, characterized in that, The ferrule is attached to the one or more pull wires extending along a first axis parallel to the longitudinal axis, a portion of the one or more pull wires being wound around the pulley, the one or more pull wires being operable to translate through a second axis positioned opposite and parallel to the first axis, the one or more pull wires extending distally along the second axis and attached to an actuator, and the actuator being attached to the reinforcing member extending distally along the second axis.

11. A sheath assembly, comprising: (a) the axle assembly according to claim 1, the proximal lumen and the distal lumen being sized to slidably receive a catheter; and (b) The handle assembly, the handle assembly including a proximal opening configured to receive the catheter, the shaft assembly extending distally from the handle assembly, the proximal opening communicating with the proximal lumen and the distal lumen.

Images