Steerable sheath

Abstract

A steerable sheath includes an elongated shaft, a handle, an actuator element on the handle, and a plurality of control wires operably coupled to the elongated shaft and the actuator element. Actuation of the actuator element adjusts the shape of the proximal and distal bends on the elongated shaft.

Description

[0001] Priority claim

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 882,050 filed on August 2, 2019 (Agent Docket No. 5540.001PRV, formerly 5171.001PRV); the entire contents of which are incorporated herein by reference. Background Art

[0003] Many minimally invasive catheter procedures use a guidewire as a track over which a sheath can be advanced toward the target treatment area. The sheath facilitates delivery of a therapeutic or diagnostic device to the target treatment area. Some sheaths can be pre-curved to match the patient's anatomy, thereby helping to guide the catheter to the target area. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In the accompanying drawings, which are not necessarily drawn to scale, similar reference numerals may describe similar components in different views. Similar reference numerals with different letter suffixes may represent different instances of similar components. The accompanying drawings generally illustrate various embodiments discussed in this document by way of example and not limitation.

[0005] Figure 1 An example of a steerable sheath is illustrated.

[0006] FIG. 2A to FIG. 2E An example of a bend in a steerable sheath is shown.

[0007] Figure 3 An example of an actuator that may be used to control a bend in a steerable sheath is shown.

[0008] Figure 4 Shows Figure 3 Exploded view of the handle in the .

[0009] Figure 5 Another example of a handle with an actuator is shown that can be used to control any steerable sheath.

[0010] Figure 6 Shows Figure 5 Exploded view of the handle in the .

[0011] Figure 7 Shows Figure 6 Side view of the handle in .

[0012] FIG. 8A to FIG. 8C An example of an anti-slack mechanism is shown.

[0013] 9A to 9D An example of a slide is shown.

[0014] FIG. 10A to FIG. 10B An example of actuating a steerable sheath is shown.

[0015] Fig.11 An example of a cross section of an elongated shaft in a steerable sheath is shown.

[0016] Fig.12 An example of the placement of a pull wire in a sheath is shown.

[0017] Fig.13 An example of a pulley is shown.

[0018] FIG. 14A to FIG. 14B An example of a variable bend sheath is shown.

[0019] FIG. 15A to FIG. 15B An example of a dilator is shown.

[0020] Fig.16 An example of a variable stiffness dilator is shown. DETAILED DESCRIPTION

[0021] Many minimally invasive catheter procedures use a guidewire as a guide rail on which a sheath can be advanced toward a target treatment area. The sheath facilitates delivery of a therapeutic device or diagnostic device to the target treatment area. Alternatively, the sheath can be used to deliver a therapeutic agent or diagnostic agent to the target treatment area. Some sheaths can be pre-bent to match the patient's anatomical structure, thereby facilitating the guidance of the therapeutic device or diagnostic device to the target area. Many shapes may be required to match different patient anatomical structures, and therefore a large inventory of sheaths may be required. In addition, it may be challenging to provide a pre-bent sheath that matches all patient anatomical structures. Therefore, it is desirable to provide a sheath that can accommodate a more diverse anatomical structure.

[0022] The present invention discloses an example of a steerable sheath, and generally relates to a long tubular catheter for delivering a diagnostic device or a therapeutic medical device including an implant to a target treatment site. In addition, the steerable sheath disclosed herein can be used to help deliver certain medicaments or diagnostic agents such as contrast agents in targeted therapy. The sheath can optionally have a hemostatic valve, which can be completely closed when the hemostatic valve is inserted into the patient's heart through an artery or vein, or any other part of the vascular system that causes blood to leak from the sheath to prevent any blood loss. The sheath can have a handle with an optional flexible side port, which is optionally attached to a three-way stopcock for suction and infusion of fluids. The handle accommodates a mechanism connected to a traction wire (also referred to herein as a control wire), which terminates in a traction wire loop at the distal end section of the sheath. When these mechanisms in the handle are actuated, the distal end section of the tubular portion of the sheath will deflect or bend in a predictable and controlled manner.

[0023] Figure 1An example of a steerable sheath 100 is shown. The sheath 100 includes an elongated shaft 108 having a proximal end portion 102, a distal end portion 106, and a middle or intermediate portion 104 therebetween.

[0024] There may be a transition section between the distal portion 106 and the middle portion 104 that has a different hardness than the distal portion 106 or the middle portion 104. For example, the transition section may have a hardness of about 55 Shore D, and this helps prevent kinking and allows for smoother tracking. Thus, the transition section may be harder than the middle portion 104 and less hard than the proximal portion 102.

[0025] The lumen extends along the length of the elongated shaft and is sized and shaped to slidably receive the therapeutic or diagnostic device. Thus, once positioned, the sheath provides a guide path to the target treatment area and protects the therapeutic or diagnostic device as it is advanced toward the treatment area and prevents damage to tissue as the therapeutic or diagnostic device is delivered.

[0026] The proximal portion 102 of the elongated shaft 108 is coupled to the distal end of a handle 118. The handle 118 includes one or more actuators 110 that can be operably coupled to the intermediate portion 104 of the elongated shaft 108 such that actuation of the actuator 110 will form a proximal bend in the intermediate portion 104. Here, the actuator can be any mechanism for controlling one or more proximal bends, but here, the actuator is a rotatable wheel. The handle can also include one or more additional actuators 112, 114, 116 that are operably coupled to the distal portion 106 of the elongated shaft 108. Actuation of the one or more actuators 112, 114, 116 will form a distal bend along the distal portion 106 of the elongated shaft. Here, only three additional actuators 112, 114, 116 are shown, but a fourth actuator is also included on the handle, but is not visible in this view. The actuator can be any mechanism for controlling the distal bend, but here, the actuators 112, 114, 116 are slides. The handle includes a body that is sized and shaped to be comfortably operated and manipulated by an operator. The proximal end 120 of the handle 118 can include a hemostatic valve such as a duckbill valve or Tuohy-Borst valve that prevents blood or other fluids from flowing out of the lumen in the sheath and helps retain a guidewire or other shaft that can be inserted into the catheter lumen. A diagnostic device or therapeutic device can be inserted into the lumen at the proximal end of the handle and advanced through the sheath lumen until the diagnostic device or therapeutic device leaves the distal end of the sheath positioned adjacent to the target treatment area.

[0027] Optionally, a side port 124 can be coupled to the proximal end 120 of the handle 118, and a single-way or multi-way stopcock can be used to open and close the fluid passage of the side port, wherein the side port fluid is coupled to the lumen of the sheath. Thus, the side port can be used to introduce fluid into the lumen or remove fluid, such as blood, from the lumen. Fluids, such as saline, can be used to flush the lumen to remove air from the lumen prior to use, or therapeutic agents can be introduced into the lumen via the side port and delivered to the treatment area. Additional details about the actuator and how the actuator forms the proximal and distal bends are disclosed below.

[0028] FIG. 2A to FIG. 2E An example of a curved portion is shown, and the curved portion may be formed in a Figure 1 In the steerable sheath 200 in or any steerable sheath disclosed herein. Figure 2A In the embodiment of the present invention, the proximal bend 202 is formed in a first plane, and the distal bend 204 is formed in the same first plane. The distal bend has a smaller radius of curvature than the proximal bend.

[0029] exist Figure 2B In the embodiment, the proximal bend 202 is formed in a first plane, and the distal bend 204 is also formed in the same first plane, but this time the distal bend is in the same plane as the distal bend. Figure 2A In the direction opposite to the distal bend in the. Figure 2B The distal curved portion 204 in FIG. 2 has a smaller radius of curvature than the proximal curved portion 202 .

[0030] exist Figure 2C In the figure, the proximal curved portion 202 is formed in a first plane (for ease of viewing the plane, the figure is relative to FIG. 2A to FIG. 2B Rotation), and the distal bend 204 is formed in a second plane transverse to the first plane, and the second plane can be orthogonal to the first plane. Therefore, the distal bend extends beyond the plane where the proximal bend is located.

[0031] exist Figure 2D In (with Figure 2C The proximal bend 202 is formed in a first plane, and the distal bend 204 is formed in a second plane transverse to the first plane, and the second plane may be orthogonal to the first plane. Figure 2C The example is similar to that in FIG, except that the distal bend is Figure 2C In the direction opposite to the distal bend in the. Figure 2D The distal bend in the curve has a smaller radius of curvature than the proximal bend.

[0032] FIG. 2A to FIG. 2DA proximal bend in a single direction is shown. However, the proximal bend may also be formed in a second direction opposite to the first direction, thereby forming a bidirectional proximal bend. In addition, any combination of a proximal bend and a distal bend may be formed. For example, a proximal bend may be formed in a first direction or in a second direction opposite to the first direction, and the proximal bend in the first direction or in the second direction may be located in a first plane. The bend forming mechanism for the proximal bend (such as those described herein) may also be replicated, thereby allowing the proximal bend to be formed in a third direction and in a fourth direction opposite to the third direction, thereby allowing a four-way bend (also referred to as a multi-way bend) to be formed in a first plane or in a second plane orthogonal to or transverse to the first plane. The proximal bend in any of these configurations may be combined with a distal bend that may be bent in a first direction or in a second direction opposite to the first direction, and that may be located in a first plane or in a second plane orthogonal to or transverse to the first plane. As will be discussed below, different actuators are disclosed that allow for different proximal and distal bend configurations to be formed.

[0033] Figure 2E An example is shown where deflecting two or more distal bends simultaneously with the proximal bend allows the sheath to navigate an infinite number of planes. Here, the proximal bend 200 is formed in a first plane. The first distal bend 204a is then formed in the same plane as the proximal bend 202. The second distal bend 204b is also formed to bend the distal end of the sheath out of the first plane into a second plane transverse to the first plane. Thus, complex bends are formed and this shows that the sheath can navigate an infinite number of planes. Figure 2E The example in FIG. 1 is implemented by one proximal bend and two distal bends, but the example can also be implemented by two proximal bends and one distal bend. Other combinations of bends can provide a sheath that can be infinitely traversed.

[0034] Figure 3An example of an actuator is shown that can be used to control the bend in a steerable sheath 300. The steerable sheath 300 includes an elongated shaft 302 having a proximal portion, a distal portion (not shown), and an intermediate portion (not shown) located between the proximal portion and the distal portion. The proximal portion of the elongated shaft 302 is coupled to a handle 310. The handle 310 includes three actuators 304, 306, 308. Here, all three actuators are rotatable wheels. Each wheel is threaded on an inner surface, and the rotation of the wheel converts the rotary motion into linear motion through a first linear screw (also referred to herein as a shuttle) in the handle, as will be discussed in more detail below. Each actuator can have a traction wire that is coupled to the shuttle so that the rotation of the wheel applies tension to the traction wire, which is also coupled to the distal portion or intermediate portion of the elongated shaft 302, thereby causing the distal portion or intermediate portion to bend to form the above FIG. 2A to FIG. 2E The distal bend or proximal bend described in . The actuator may also have a second linear screw (also referred to herein as a shuttle), which is parallel to the first linear screw. And then, the second traction wire is connected to the second shuttle, and is also usually connected to the distal portion or middle portion of the elongated shaft at an axial position on the opposite side that is the same as the first traction wire, but circumferentially offset by about 180 degrees from the connection point of the first traction wire. Therefore, the actuation of the first traction wire causes the elongated shaft to bend in a first plane along a first direction, and the actuation of the second traction wire causes the elongated shaft to bend in the first plane in the opposite direction. The thread on the second shuttle can be opposite to the thread on the first shuttle, so that the rotation of the wheel causes one shuttle to move in one direction, while the second shuttle moves in the opposite direction, thereby controlling the two traction wires simultaneously.

[0035] The second actuator 306 is generally in the same form as the first actuator 304, and has one or two traction wires attached to the middle or distal portion of the elongated shaft, but in this example, there are two traction wires each attached to the distal portion of the elongated shaft. Rotation of the second wheel tensions the first traction wire, thereby bending the distal portion of the elongated shaft into a distal bend in a first plane, and rotation of the second wheel in the opposite direction tensions the second traction wire, thereby bending the distal bend in the first plane in opposite directions. Both traction wires are connected to the distal portion of the elongated shaft and are circumferentially offset from each other, such as by 180 degrees. Two shuttles are also included, each having a thread opposite to the other shuttle, so that actuation of the wheel moves the shuttles in opposite directions (one forward and one backward).

[0036] The third actuator 308 is generally in the same form as the first actuator 304 and the second actuator 306, and has one or two traction wires, which are attached to the middle part or the distal part of the elongated shaft, but in this example, there are two traction wires each attached to the distal part of the elongated shaft. The rotation of the third wheel tensions the first traction wire, thereby bending the distal part of the elongated shaft into a distal bend in the second plane, and the rotation of the second wheel in the opposite direction tensions the second traction wire, thereby bending the distal bend in the second plane in the opposite direction. The second plane can be orthogonal to or transverse to the first plane. The two traction wires are connected to the distal part of the elongated shaft and are circumferentially offset from each other, such as 180 degrees. The two traction wires in the second actuator are also circumferentially offset. Therefore, for example, the four traction wires in the second actuator and the third actuator can be connected to the distal part of the elongated shaft at the same axial position, but circumferentially offset from each other by 90 degrees. This is not intended to be limiting, and any angular spacing may be used. Two shuttles are also used, each having threads opposite to the other, so that actuation of the wheel moves the shuttles in opposite directions (one forward and one backward). Additional drawings and details describing actuation of the rotatable wheel and the pull wire are provided below.

[0037] The proximal end of handle 310 may include a window 316 that allows an operator to view the interior of the handle to determine if there are any bubbles. Alternatively, a portion of the handle assembly or the entire handle assembly may be made of a transparent material that allows an operator to inspect bubbles that are accidentally introduced. If so, the bubbles may be flushed out or sucked out by a side port 312 that is coupled to the elongated shaft lumen through fluid. (Single-pass or multi-pass) cocks may be coupled to the side ports to control fluid flow. A hemostatic valve 314 such as a duckbill valve or a Tuohy-Borst valve may be used to prevent blood from flowing out of the lumen in the sheath.

[0038] Figure 4 Shows Figure 3Exploded view of handle 300 in FIG. Here, actuators 304, 306, 308 have upper and lower rotatable wheel halves that clamp around the handle. The inner surface of each upper and lower rotatable wheel 304, 306, 308 is threaded so that circular rotation of the wheel is converted into linear motion of each shuttle 334, 336. Here, each actuator 304, 306, 308 includes two shuttles, and rotation of the wheel moves one shuttle distally and the other shuttle proximally. Rotation of the wheel in the opposite direction moves the shuttles in the opposite direction, so that now one shuttle moves proximally and the other shuttle moves distally. The thread can be a standard helical thread, or here, the thread is a diamond-shaped protrusion 342, wherein the four sides of the diamond provide an inclined surface with a curve so that the slope of the inclination changes from positive to negative, or from negative to positive. Thus, when the diamond-shaped protrusions engage the threads on the shuttles, rotation of the wheel will be converted into linear motion of the shuttles along shaft 330. A traction wire (not shown in this figure) is attached to each shuttle, and thus, movement of the shuttles applies tension to or reduces tension on the traction wires, thereby forming a proximal or distal bend in the elongated shaft. As will be shown in more detail in this specification, hubs 338, 340 (here, three hubs) have orifices set through the hubs, and the traction wires can pass through the hubs. The hubs also help to secure the rotatable wheels. Shaft 330 includes a central lumen 332 that is fluidly coupled to the lumen in the sheath. The proximal portion of handle 310 may include Figure 3 A window, side port, or hemostatic valve is shown in which air bubbles in the lumen (or transparent handle disclosed above) are observed.

[0039] Figure 5Another example of a handle 500 with an actuator is shown, which can be used to control any steerable sheath. The handle 500 is coupled to the proximal end 502 of any of the steerable sheaths disclosed herein, and the actuation of the actuators 504, 506 can be used to form any of the proximal bends or distal bends disclosed herein. The proximal end 512 of the handle can include a side port 516 or a hemostatic valve 514. The side port 516 is substantially the same as previously disclosed and includes a short length of tube that is coupled to the proximal end of the handle 500 and is fluidically coupled to the lumen of the elongated shaft of the steerable sheath to allow fluid to be introduced into the lumen or removed from the lumen. A single-pass or multi-pass stopcock can be coupled to the free end of the side port tube to control fluid flow. The hemostatic valve 514 can be a duckbill valve, a Tuohy-Borst valve, or other valve that allows a catheter or other device to be introduced into the handle while controlling the flow of fluids such as blood out of the proximal end of the handle. The hemostatic valve can also be used to help retain a guidewire or elongated shaft in the handle and prevent movement when the hemostatic valve is tightened, such as when a Tuohy-Borst valve is used.

[0040] The distal-most actuator 504 may be an actuatable wheel that an operator rotates to control the proximal bend on the steerable sheath. Figure 4 Similar to the example in , the rotational motion of the actuable wheel is converted into linear motion of one, two or more shuttles attached to a traction wire connected to the middle portion of the elongated shaft. Thus, rotation of the wheel in a first direction will tension the first traction wire and form a proximal bend in a first direction and in a first plane along the middle portion of the steerable sheath, while rotation of the wheel in the opposite direction releases the tension of the first traction wire, thereby allowing the proximal bend to return to an unbiased configuration, and further actuation of the wheel then applies tension to an optional second traction wire (in the presence of a second shuttle), which then forms a proximal bend in a second direction opposite to the first direction and in the same first plane. Other disclosures related to traction wire configurations and accessories to the steerable sheath are provided below.

[0041] The handle is also coupled to an additional actuator 506, and in this example, there are four additional actuators 506. In this view, two actuators are visible, and the other two actuators are not visible. Here, the actuator 506 includes a textured distal ramp portion 508 and a proximal ramp portion 510 located on the distal end of the actuator, which is pivotally coupled to the distal ramp portion 508. Pushing the proximal ramp portion 510 distally causes the proximal ramp portion 510 to rise upwardly and away from the rack, which is disposed in the handle and is not visible in this view. This will disconnect the teeth connected to the proximal ramp portion from the rack and allow the slider to advance distally. Advancing distally allows the tension of the traction wire of the distal portion of the elongated shaft of the slider and the steerable sheath to be released, thereby restoring the distal bend to an unbiased configuration.

[0042] The proximal retraction of the proximal ramp portion 508 causes the slider to advance proximally along the rack, because the teeth are bent to form a cam surface that is easy to slide on the rack when retracting proximally. The proximal retraction of the proximal ramp portion 508 causes the slider to move proximally, which applies tension to the traction wire connected to the slider, thereby forming a distal curvature in the distal portion of the elongated shaft of the steerable sheath. The curvature can be located in the same first plane as the proximal curvature, or the curvature can be located in a second plane that is transverse to or orthogonal to the first plane. The second slider can be arranged on the handle in a circumferentially offset manner, so the second slider is offset by about 180 degrees, and the second slider can be used to form a distal curvature in the direction opposite to the first direction and in the same plane. The handle can also include two additional sliders to form a distal curvature in the first direction or in the second direction opposite to the first direction and in the first plane or in the second plane that is transverse to or orthogonal to the first plane. Thus, for example, where there are four sliders, two sliders form distal bends in a first plane (the same plane as the proximal bend) in a first direction or an opposite second direction, and the other two sliders form distal bends in a second plane orthogonal or transverse to the first plane in the first direction or an opposite second direction. Each slider is attached to a traction wire, so there will be four traction wires, and these four traction wires can be connected to the distal portion of the elongated shaft of the sheath at circumferentially offset positions, for example, at positions every 90 degrees, wherein the mating traction wire pairs are offset by 180 degrees. In addition, as described above Figure 2E As observed in , simultaneously deflecting two or more of the distal bends and the proximal bend allows the sheath to traverse an infinite number of planes. Alternatively, simultaneously deflecting two or more proximal bends and one distal bend also achieves an infinitely traversable sheath.

[0043] Figure 6 Shows Figure 5 , and more clearly illustrates the operation of the actuator. As previously disclosed, the handle 500 includes a slide 506 having a proximal portion 510 and a distal portion 508 for locking the slide, unlocking the slide, advancing and retracting the slide along a toothed rack 604. The teeth 602 on the bottom of the proximal portion 510 engage with the teeth on the rack 604. When the proximal portion 510 of the slide is pushed distally, this causes the proximal portion of the slide to rise upward and causes the teeth 602 to disengage from the teeth on the rack 604. The spring disposed between the proximal portion and the distal portion is biased to push the proximal portion back downward so that the teeth 602 engage with the teeth in the rack 604 to lock the slide and prevent movement distally. This will be described in more detail below. Here, the handle 500 includes four slides. In this view, two slides are visible, and the other two slides are not visible. The sliders slide along channels in the handle body to ensure smooth linear motion. A pull wire is attached to each slider and then extends distally along the handle, through holes 620, 614 in hubs 618, 610, and the distal end of the pull wire is coupled to the distal portion of the elongated shaft.

[0044] The most distal actuator includes a rotatable wheel 504, which is divided into two halves arranged around a shuttle 608 (also referred to as a lead screw) that converts rotary motion into linear motion. The thread 606 on the inner surface of the wheel 504 engages with the mating thread on the shuttle 608, and the shuttle 608 slides on an axis 616 with a square or rectangular cross section. Because the shuttle cannot rotate around the axis 616, the rotation of the wheel 504 is converted into the linear motion of the shuttle 608 along the axis 616. The traction wire is attached to the distal portion of the shuttle and can pass through the aperture 614 in the hub 610, and the free end of the traction wire is then connected to the middle portion of the elongated shaft of the steerable sheath. The hubs 618, 610 limit the rotatable wheel so that the rotatable wheel can only rotate and prevent the linear motion of the wheel. The hubs 618, 610 also help to fix the components together. The orifices 620, 614 in the hubs 618, 610 allow the traction wire to pass through the hubs unimpeded and also prevent the traction wire from tangling. The distal cap 612 seals the distal end of the handle. Extending proximally from the shaft 616 is a cylindrical rod with teeth, which serves as a rack 604 on which the slide moves. The teeth 602 on each slide 506 prevent the slide from moving distally when engaging with the teeth on the rack, which locks the slide in place, thereby maintaining the tension of the traction wire and maintaining the bend formed by the traction wire. Movement to the proximal end is not inhibited by the engagement of the teeth with the teeth on the rack. This locking mechanism is described in more detail below. Figure 6A rotatable wheel with only a single shuttle 608 is shown, however this is not intended to be limiting and a second shuttle may be added to control a second pull wire coupled to the middle portion of the elongated shaft of the sheath. The threads on the second shuttle may be opposite to the threads of the first shuttle so that rotation of the wheel will move one shuttle proximally while the second shuttle moves distally in the opposite direction. Alternatively, the threads of the shuttles may be identical so that both shuttles move in the same direction when actuated by the wheel.

[0045] Figure 7 Shows Figure 6 500, and operates in the same manner as previously described. Figure 7 A single shuttle 608 is shown, and also shown is the engagement of teeth 602 with teeth on rack 604. The two slides 506 are also shown as being circumferentially offset from one another, here by 180 degrees, which is helpful to the operator as an indication of the direction in which each slide controls the bend, but this is not intended to be limiting, and the slides may be spaced apart in any desired configuration.

[0046] FIG. 8A to FIG. 8C Shown with Figure 6 to Figure 7 Another example of a handle similar to that in but differing primarily in that an optional anti-slack feature is added. Because actuation of the rotatable wheel forms a bend in one portion of the elongated shaft of the steerable sheath, such as in the middle portion, the shaft forms a rounded bend, which causes slack in the traction wires coupled to the slider. When the slider is actuated, the slider must first be moved to absorb excess slack before the sliders are able to tension their respective traction wires and form bends in other portions of the elongated shaft of the steerable sheath. Therefore, the addition of the anti-slack feature eliminates slack in the slider traction wires as the rotatable wheel actuates its traction wires, and therefore, actuation of the slider maintains close correspondence with the formation of the bend in the steerable sheath, and no slack elimination is required.

[0047] Fig. 8A The distal-most actuator is shown, which includes a rotatable wheel 504 having a moving shuttle 608 that slides along an axis 616. The handle 800 also includes a slider 506 having a proximal slider portion 508 and a distal slider portion 510, and a locking tooth 602 that releasably engages with a tooth 820 in the rack. The operation of the distal-most actuator and the slider is the same as previously described above. Figure 6 to Figure 7The same as described in. The relaxation mechanism includes a pusher 806 such as a tube similar to a hypotube or other tube connected to the proximal end of the shuttle 608. The traction wire connected to the slide can freely pass through the hypotube 806, thereby not hindering the actuation of the distal curved portion. As the shuttle 608 moves toward the proximal end, the pusher 806 abuts the distal end of the slide 506, and the continuous proximal movement of the shuttle correspondingly pushes the slide 506 toward the proximal end, thereby eliminating any slack in the traction wire connected to the slide. Therefore, when the slide is retracted toward the proximal end to tension its corresponding traction wire, since there is no slack in the traction wire and since the control of the resulting curved portion corresponds closely to the actuation of the slide, tension is immediately applied. When the shuttle moves toward the distal end in the opposite direction, the pusher 806 is disconnected from the slide, and the slide can move toward the distal end. This anti-slack feature can be used in any handle example in the handle example disclosed herein. Fig. 8A Only two sliders are shown, but a total of four sliders may be included, and the other two sliders are not visible in this view. In addition, only a single shuttle with an anti-slack feature is shown, but a second shuttle with or without an anti-slack feature may also be added. In addition, the anti-slack feature may include two pushers for each shuttle to abut and push the two sliders, and therefore, when there are two shuttles, slack in all four traction wires connected to the sliders can be avoided. The traction wire 802 connected to the slider can extend through the channel or lumen in the pusher and pass through the orifice in the hub 618, 610 as previously described. The traction wire 804 is connected to the shuttle 608 and can pass through the orifice in the shuttle and the distal hub 610. Fig. 8A Other aspects of Figure 6 to Figure 7 The handles in are roughly the same.

[0048] Figure 8B Shows Fig. 8A , and highlights the pusher 806 of the shuttle 608 coupled to the proximal end and the pusher 806 abutting the slider 506. Here, a single pusher is shown, but it will be appreciated by those skilled in the art that a pusher may be coupled to each shuttle to push the corresponding slider. Also in this view, the rotatable wheel is removed to highlight the shuttle 608. Figure 8B Other aspects of Fig. 8A Roughly the same as in .

[0049] Figure 8C Shows FIG. 8A to FIG. 8B 800 in FIG. Other aspects of the handle are similar to FIG. 8A to FIG. 8B Roughly the same as in .

[0050] 9A to 9DAn example of a slide is shown that may be used in any of the handles disclosed herein. Fig.9A Slide 900 is shown, and this slide 900 comprises proximal slide part 904, distal slide part 902, spring 906, tooth 908 and hinge or pivot 910.As previously discussed above, proximal part 904 comprises ramp portion, and this ramp portion is configured to be easy to actuate by thumb or finger, and this ramp portion controls the locking of slide.Distal part 902 also comprises ramp portion, and this ramp portion can be textured or knurled, so that finger or thumb can easily grasp and move proximal slide part.Hinge or pin and pivot 910 couple two halves of slide together, and therefore these two halves can pivot relative to each other.Spring 906 is coupled to two parts of slide, and is biased to push two halves away from each other, so two halves of slide are flat and roughly colinear with each other.This ensures that tooth 908 engages with the tooth on the rack in handle. The tooth 908 includes a flat distal face that prevents the slider mechanism from being actuated distally unless the proximal slider portion 904 is pushed distally, causing the proximal end of the proximal slider portion 904 to pivot slightly upward enough to disengage the tooth 908 from the teeth in the rack and allow the slider to advance distally. The tooth 908 also has a curved shape on the proximal end that acts as a cam so that when the slider is pushed proximally, the cam will slide smoothly over the teeth in the rack and not prevent the slider from moving proximally.

[0051] Fig. 9B Shows Fig.9A A three-dimensional view of the sliding member in FIG.

[0052] Fig. 9C An example of a tooth on the rack 920 in any of the handles disclosed herein and with which the tooth 908 on the slide can engage is shown. The tooth has an angled leading edge that allows the cam surface of the tooth 908 to slide easily during proximal retraction of the slide and a vertical trailing edge that engages the slide and prevents the slide from moving distally unless as described above with respect to Fig.9A As disclosed, the teeth are disengaged from the teeth on the rack.

[0053] Fig.9D Slider 900 is shown engaging teeth 920 on rack 920 .

[0054] FIG. 10A to FIG. 10B Shows the use of Figures 5 to 7 An example of actuating a steerable sheath using a rotatable wheel actuator and a slider actuator disclosed in Fig. 10AIn the embodiment of the present invention, the steerable sheath 1000 includes an elongated shaft 1006 having a lumen and a handle 1020. The proximal end of the elongated shaft 1006 is connected to the handle 1020. The handle 1020 includes two actuators such as a rotatable wheel 1010 and a slider 1018. A hemostatic valve 1022 such as a duckbill valve or a Tuohy-Borst valve can be included on the proximal end of the handle to prevent fluid leakage and fix a guide wire, a catheter or other elongated instruments that can be slidably disposed in the lumen of the steerable sheath. The proximal ring 1004 and the distal ring 1002 are connected to the elongated shaft and serve as a connection point for a traction wire. For example, here, the distal ring 1002 is connected to the distal portion of the elongated shaft, and the proximal ring 1004 is connected to the middle portion or middle portion of the elongated shaft, which is disposed between the proximal portion and the distal portion of the elongated shaft. A traction wire 1016 is coupled to the distal ring 1002 and the slider 1018, and another traction wire 1008 is coupled to the proximal ring 1004 and the shuttle 1012. The rotation of the rotatable wheel 1010 is converted into a linear motion of the shuttle 1012. Thus, the actuation of the rotatable wheel controls the bending of the middle portion of the elongated shaft to form a proximal curvature, and the actuation of the slider controls the bending of the distal portion of the elongated shaft to form a distal curvature. In addition, a pusher 1014 is also coupled to the shuttle 1012, so that when the shuttle 1012 moves proximally, the shuttle 1012 moves the pusher 1014 proximally, and the pusher 1014 abuts the slider 1018, thereby pushing the slider back in cooperation with the rotation of the wheel 1010. Thus, when the tension of the traction wire 1008 increases and forms the proximal bend, any slack in the traction wire 1016 due to the slider being pushed proximally by the pusher 1014 is absorbed. Thus, when the slider 1018 is actuated, the slider will not need to be retracted proximally to absorb the slack before the traction wire controls the distal bend. The actuation of the slider will result in an immediate response of the distal bend. Fig. 10A The example in only shows a single shuttle, but it will be appreciated by those skilled in the art that two or more shuttles may be used, as previously disclosed above. Fig. 10A Only a single slide is also shown, but this is not intended to be limiting and may be used, for example, in Figures 5 to 7 Two, three, four or more sliders in the sheath control the distal curvature in many other directions. Alternatively, multiple sliders at different locations are controlled to allow the sheath to turn in many other directions.

[0055] Fig. 10BActuation of the rotatable wheel 1010 is shown to move the shuttle 1012 proximally, thereby forming a proximal bend in the middle portion of the elongated shaft 1006 of the steerable sheath. Where the rotatable wheel 1010 includes a second shuttle, if a second pull wire (not shown) is coupled to the proximal ring at a location circumferentially offset from the first pull wire by approximately 180 degrees, actuation of the wheel in the opposite direction will form a proximal bend in the opposite direction but in the same plane. Fig. 10B Also shown is a pusher 1014 that abuts against the slider and pushes the slider proximally to remove slack from the traction wire 1016. The slider can be 9A to 9D Unwanted movement is prevented by locking.

[0056] Fig.11 The cross section of the elongated shaft 1102 of the steerable sheath is shown. The elongated shaft 1102 can be formed by several layers of material, for example, the innermost layer 1106 forming the lumen of the steerable sheath can be a polytetrafluoroethylene (PTFE) tube layer to provide a smooth surface. Next, one, two, three, four or more small diameter tubes 1112 such as polyimide tubes or PTFE tubes are arranged on the surface of the innermost layer 1106, and these tubes form the lumen of the distal bending part traction wire. The number of tubes used depends on how many traction wires are used. Here, four tubes are used to accommodate four traction wires. These tubes are spaced apart approximately every 90 degrees, but this is not restrictive, and any desired interval can be used. Then, an inner braided layer 1104 is arranged on the tube 1112, and then one or two, three, four or more other small diameter tubes 1114 such as polyimide tubes, PTFE tubes or other fluoropolymer tubes are arranged on the inner braided layer 1104. Tube 1114 provides lumen for the proximal bend traction wires, and there are two tubes 1114 circumferentially offset 180 degrees. Any positioning can be used, and the number of tubes depends on the number of proximal bend traction wires. An outer braid 1110 is provided on the proximal bend traction wires, and a final outer polymer layer 1108 is provided on all objects. Thus, each traction wire can be slidably disposed in a separate lumen to ensure that the actuation of each traction wire is smooth, and friction is reduced and entanglement of the traction wires is avoided.

[0057] Fig.12An example of how a traction wire can be arranged through the elongated shaft 1202 of any of the steerable sheaths disclosed herein as a way to address some traction wire slack that may result when the sheath is bent into different configurations is shown. The traction wire can be arranged to pass through the elongated shaft in a linear manner and parallel to the longitudinal axis of the elongated shaft, or in any of these examples, the arrangement of the traction wire can be changed to minimize slack. A traction wire loop 1204 is coupled to the distal portion of the elongated shaft to control the distal curvature, and a traction wire loop 1206 is coupled to the middle portion of the elongated shaft to control the proximal curvature.

[0058] In the case where the proximal bidirectional bend is in the plane of the page, the two traction wires 1218, 1220 controlling the distal bend in the same plane will experience relaxation or tension. To prevent this from happening, these traction wires 1218, 1220 are laid through the channel in the proximal traction wire loop 1206. The traction wires 1218, 120 in the plane of the distal bend are then circumferentially offset from the original axis of the traction wire and re-laid along a path defining the following plane: the plane is orthogonal to or transverse to the plane of the proximal bend. This can be achieved by offsetting the traction wires 11218, 1220 from their initial axis by approximately 90 degrees. When the proximal bend is actuated, the relaxation or tension in the re-laid traction wires is therefore minimized.

[0059] In this example, two traction wires 1208, 1210 extend linearly and parallel to the elongated axis, and both traction wires 1208, 1210 are connected to a traction wire loop 1206, which is at the proximal end of the traction wire loop 1204. In this example, the connection points 1214, 1216 are circumferentially offset by about 180 degrees. Two additional traction wires 1218, 1220 also extend linearly and parallel to the longitudinal axis of the elongated axis, but then, the traction wires 1218, 1220 are re-routed adjacent to the traction wire loop 1206 to 1222. The two traction wires then continue to extend linearly and parallel to the elongated axis until the two traction wires are attached 1224, 1226 to the traction wire loop 1204, which is at the distal end of the traction wire loop 1206. The connection points are circumferentially offset from each other by about 180 degrees. Rerouting the pull wire can help control tension and slack in the pull wire and can provide better control over deflection and bending.

[0060] Fig.13An example of using a pulley in any of the examples of the steerable sheaths disclosed herein to facilitate manipulation of a traction wire is shown. An elongated shaft 1316 is coupled to a handle 1302. Traction wires 1310, 1312 are coupled to the elongated shaft at 1314 and are also coupled to a handle at 1308. Pulley 1306 is operatively coupled to traction wires 1310, 1312, thereby providing a mechanical advantage when the pulley is actuated as indicated by arrow 1304. The use of a pulley configuration allows highly responsive deflection under short actuation. In some examples, the ratio of deflection to actuation is greater than 1:1, while in other examples, the ratio may be less than 1:1. This example shows two traction wires with pulleys, however this is not intended to be limiting, but one traction wire may have a pulley and another traction wire may not have a pulley. And in examples with more than two traction wires, pulleys may be used with any number of those traction wires.

[0061] FIG. 14A to FIG. 14B An example of a variable bend sheath 1400 is shown. The device includes an inner rigid shaft 1402 slidably disposed in a sheath 1404. The inner shaft 1402 has a pre-set bend in it. As the inner shaft 1402 is advanced through the outer sheath 1404 and the distal portion of the inner shaft 1402 becomes free of the outer sheath 1404, the distal portion of the inner shaft 1402 will begin to bend into its unbiased natural bend 1406. The radius of curvature of the bend 1406 depends on the degree of exposure of the distal portion. Fig.14A In the embodiment, a relatively large portion of the distal end of the inner shaft is unconstrained, and thus the bend will have a relatively large bending radius.

[0062] exist Fig. 14B In the embodiment of the present invention, a relatively short section of the distal end of the inner shaft is unconstrained, so the bend will have a relatively small bend radius. Once the desired bend is formed, a catheter or other diagnostic or interventional device can be inserted into the lumen in the inner shaft, and the bend will facilitate delivery to the target treatment area. A handle can be coupled to the inner and outer shafts and the sheath to help control relative motion. The variable bend sheath can be used with any of the other actuation mechanisms to further control the bend in the steerable sheath.

[0063] FIG. 15A to FIG. 15B A dilator with a recess that can be used with any of the steerable sheaths disclosed herein is shown. Fig.15A In the embodiment of the present invention, the dilator 1502 includes an elongated shaft having a tapered distal atraumatic tip 1504 and a hub or other connector at the proximal end 1508 of the dilator. A recess or annular groove 1506 disposed circumferentially around the distal portion of the dilator provides a receptacle for receiving the distal tip of a steerable sheath, thereby creating a better, smoother dilator-sheath transition.

[0064] exist Fig. 15B In the embodiment of the present invention, the dilator 1502 is inserted into any of the steerable sheaths disclosed herein. The distal tip of the steerable sheath is formed of an elastic material that is biased to contract to a diameter smaller than the diameter of the main portion of the sheath. Therefore, when the dilator is slidably advanced through the lumen in the sheath, the distal end 1512 of the sheath is forced to maintain its larger diameter configuration. However, when the dilator is advanced far enough so that the distal end of the sheath 1512 reaches the annular groove 1506, the distal end of the sheath 1512 will contract to its smaller diameter when it is not biased and contract into the annular groove, thereby protecting the leading edge of the sheath in the groove and providing a smooth transition from the dilator to the sheath without a bump or discontinuous transition.

[0065] Fig.16 An example of a variable stiffness dilator is shown, which can be used with any steerable sheath disclosed herein. The dilator 1602 includes a tapered distal atraumatic tip 1606 and a hub or other connector 1612 located on the proximal end. The elongated shaft of the dilator can be divided into a proximal portion 1610, a distal portion 1604, and a middle portion or intermediate portion 1608 disposed between the proximal portion and the distal portion. The dilator can be manufactured so that the elongated shaft has any desired stiffness profile along the elongated shaft. For example, the intermediate portion 1608 can be softer and more flexible than the proximal portion 1610 or the distal portion 1604. When the dilator is inserted into any steerable sheath in the steerable sheath disclosed herein, the softer intermediate portion will therefore be more easily bent and folded as the steerable sheath bends. The proximal portion can be the stiffest to give the dilator pushability during delivery, while the distal portion can have the same stiffness as the proximal portion, can be softer if desired, or otherwise tailed to provide sufficient stiffness to push against tissue without causing undesirable damage to the tissue. Any stiffness can be used in the proximal portion, distal portion, or middle portion of the dilator shaft. Thus, the steerable sheath can be steered by the dilator disposed in the steerable sheath.

[0066] In any of the examples of the steerable sheaths disclosed herein, the traction wire can be made of any number of different materials. For example, round or flat metal wires such as stainless steel can be used, or high-strength polymer filaments such as Kevlar can be used.

[0067] In any of the examples of steerable sheaths disclosed herein, the braided layer (e.g. Fig.11The braided layer in the filaments may be made of any number of different materials. For example, round or flat wires such as stainless steel or nitinol are used to avoid kinking. Alternatively, high-strength monofilament polymers such as polyetheretherketone (PEEK) or multifilaments such as Kevlar and aramid fibers (Vectran) may be used as non-magnetic.

[0068] In any of the examples of steerable sheaths disclosed herein, the sheath can have any diameter or length. For example, a sheath in the range of 8.5 French to 15.5 French can be used. Similarly, the radius of curvature of the proximal and distal curves can be any radius required for a particular surgery or anatomy.

[0069] In any of the examples of steerable sheaths disclosed herein, any of the actuators may include indicia such as printing, markings, colors to indicate to an operator which actuator controls which direction of which bend.

[0070] In any of the examples of steerable sheaths disclosed herein, the proximal and distal portions of the elongated shaft of the steerable sheath can have any desired lengths, and this can be based on the surgery or anatomy being performed. For example, the distal portion of the steerable sheath can have a distal portion formed with a distal bend, and the distal portion can be the most distal 2 cm to 4 cm of the elongated shaft. Similarly, the middle portion of the elongated shaft formed with a proximal bend can be the 4 cm to 10 cm of the elongated shaft immediately proximal to the distal portion.

[0071] Notes and Examples

[0072] The following non-limiting examples particularly detail certain aspects of the present subject matter to address the challenges and provide the benefits discussed herein.

[0073] Example 1 is a steerable sheath, the sheath comprising: an elongated shaft, the elongated shaft comprising a proximal portion, a distal portion, an intermediate portion disposed between the proximal portion and the distal portion, and a lumen extending between the proximal portion and the distal portion; a first traction wire, the first traction wire having a proximal end and a distal end, the first traction wire extending along the elongated shaft; a second traction wire, the second traction wire having a proximal end and a distal end, the second traction wire extending along the elongated shaft; a handle, the handle being coupled to the proximal portion of the elongated shaft; a first actuator, the first actuator being disposed on the handle; and a second actuator, the second actuator being disposed on the handle, wherein the distal end of the first traction wire is coupled to the intermediate portion of the elongated shaft, and the proximal end of the first traction wire is coupled to the first actuator, wherein the distal end of the second traction wire The first actuator is connected to the distal portion of the elongated shaft, and the proximal end of the second traction wire is connected to the second actuator, wherein actuation of the first actuator in a first direction tensions the first traction wire, thereby forming a proximal bend in a first arcuate direction along the middle portion of the elongated shaft in a first plane, and wherein actuation of the first actuator in a second direction opposite to the first direction releases the tension of the first traction wire, thereby allowing the proximal bend to return to an unbiased configuration, wherein actuation of the second actuator in the first direction tensions the second traction wire, thereby forming a distal bend in a first bend direction along the distal portion of the elongated shaft in a second plane, and wherein actuation of the second actuator in a second direction opposite to the first direction releases the tension of the second traction wire, thereby allowing the distal bend to return to an unbiased configuration.

[0074] Example 2 is the sheath of Example 1, wherein the second plane is transverse to the first plane.

[0075] Example 3 is a sheath of any one of Examples 1 to 2, wherein the sheath also includes a pusher rod connected to the first actuator, and wherein actuation of the first actuator in a first direction causes the pusher rod to engage with the second actuator and causes the second actuator to move in coordination with the first actuator, thereby preventing loosening of the second traction wire.

[0076] Example 4 is a sheath of any one of Examples 1 to 3, wherein the sheath also includes a third traction wire having a proximal end and a distal end, and the third traction wire extends along the elongated axis, wherein the distal end of the third traction wire is connected to the middle portion of the elongated axis at a position opposite to the first traction wire, and the proximal end of the third traction wire is connected to the first actuator, and wherein actuation of the first actuator in a second direction opposite to the first direction tensions the third traction wire so that the proximal bend is bent along the middle portion of the elongated axis and in the first plane in a direction opposite to the first arc direction.

[0077] Example 5 is a sheath of any one of Examples 1 to 4, wherein the sheath further comprises a fourth traction wire and a third actuator, wherein the third actuator is disposed on the handle, the fourth traction wire having a proximal end and a distal end and extending along the elongated axis, wherein the distal end of the fourth traction wire is connected to the distal portion of the elongated axis at a position opposite to the second traction wire, and the proximal end of the fourth traction wire is connected to the third actuator, and wherein actuation of the third actuator in a first direction tensions the fourth traction wire so that the distal bend bends along the distal portion of the elongated axis and in the second plane in a direction opposite to the first bending direction, and wherein actuation of the third actuator in a second direction opposite to the first direction of the third actuator releases the tension of the fourth traction wire, thereby allowing the distal bend to return to an unbiased configuration.

[0078] Example 6 is a sheath of any one of Examples 1 to 5, wherein the sheath further comprises a fifth traction wire and a fourth actuator, wherein the fourth actuator is disposed on the handle, the fifth traction wire having a proximal end and a distal end and extending along the elongated axis, wherein the distal end of the fifth traction wire is connected to the distal portion of the elongated axis at a position circumferentially offset relative to the second traction wire and the fourth traction wire, and the proximal end of the fifth traction wire is connected to the fourth actuator, and wherein actuation of the fourth actuator in a first direction tensions the fifth traction wire so that the distal bend bends in a second bending direction along the distal portion of the elongated axis and in the first plane, and wherein actuation of the fourth actuator in a second direction opposite to the first direction of the fourth actuator releases the tension of the fifth traction wire, thereby allowing the distal bend to return to an unbiased configuration.

[0079] Example 7 is a sheath of any one of Examples 1 to 6, wherein the sheath further comprises a sixth traction wire and a fifth actuator, wherein the fifth actuator is disposed on the handle, the sixth traction wire having a proximal end and a distal end and extending along the elongated axis, wherein the distal end of the sixth traction wire is connected to the distal portion of the elongated axis at a position opposite to the fifth traction wire, and the proximal end of the sixth traction wire is connected to the fifth actuator, and wherein actuation of the fifth actuator in a first direction tensions the sixth traction wire so that the distal bend bends along the distal portion of the elongated axis and in the first plane in a direction opposite to the second bending direction, and wherein actuation of the fifth actuator in a second direction opposite to the first direction of the fifth actuator releases the tension of the sixth traction wire, thereby allowing the distal bend to return to an unbiased configuration.

[0080] Example 8 is the sheath of any of Examples 1-7, wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator comprises a slide.

[0081] Example 9 is the sheath of any of Examples 1 to 9, wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator includes a lock to prevent slidable movement thereof.

[0082] Example 10 is the sheath of any one of Examples 1 to 9, wherein the proximal bend has a radius of curvature, and the distal bend has a radius of curvature that is smaller than the radius of curvature of the proximal bend, or the proximal bend may have a radius of curvature that is smaller than the radius of curvature of the distal bend.

[0083] Example 11 is the sheath of any of Examples 1 to 10, wherein the first actuator comprises a rotatable wheel threadably engaged with a threaded shuttle, wherein rotation of the rotatable wheel is converted into linear motion of the shuttle.

[0084] Example 12 is the sheath of any one of Examples 1 to 11, the sheath further comprising a mark located on the first actuator or the second actuator, the mark being configured to identify actuation of the actuator element by a change in shape of the proximal bend or the distal bend.

[0085] Example 13 is a sheath of any one of Examples 1 to 12, wherein the sheath also includes a dilator disposed in the tubular cavity of the elongated shaft, wherein the dilator includes a proximal end, a distal end, and a middle portion disposed between the proximal end and the distal end, wherein the middle portion is more flexible than the proximal end or the distal end of the dilator, thereby facilitating the steering of the elongated shaft.

[0086] Example 14 is the sheath of any one of Examples 1 to 13, wherein the distal bend includes a first distal bend that bends the elongated axis in the second plane and a second distal bend that bends the elongated axis in a third plane transverse to the first plane, thereby forming a sheath capable of unlimited travel.

[0087] Example 15 is a method for manipulating a sheath, the method comprising: providing an elongated shaft having a proximal portion, a distal portion, an intermediate portion disposed between the proximal portion and the distal portion, and a lumen extending between the proximal portion and the distal portion; actuating a first actuator in a first direction, the first actuator being disposed on a handle connected to the proximal portion of the elongated shaft, thereby tensioning a first traction wire connected to the intermediate portion; forming a proximal bend in the intermediate portion in a first plane; actuating a second actuator in the first direction, the second actuator being disposed on the handle, thereby tensioning a second traction wire connected to the distal portion; and forming a distal bend in the distal portion in a second plane.

[0088] Example 16 is the method of Example 15, wherein actuating the first actuator includes rotating a rotatable wheel.

[0089] Example 17 is the method of any of Examples 15-16, wherein actuating the second actuator comprises sliding a slider.

[0090] Example 18 is the method of any one of Examples 15 to 17, wherein the first plane is transverse to the second plane.

[0091] Example 19 is the method of any one of Examples 15 to 18, wherein the distal bend has a radius of curvature, and the proximal bend has a radius of curvature that is larger than the radius of curvature of the distal bend.

[0092] Example 20 is the method of any one of Examples 15 to 19, further comprising actuating the first actuator in a second direction opposite to the first direction, thereby releasing the tension on the first traction wire and tensioning the third traction wire connected to the middle portion, and reforming the proximal bend in the middle portion in an opposite direction and in the first plane.

[0093] Example 21 is a method of any one of Examples 15 to 20, further comprising actuating a third actuator in a first direction, the third actuator being disposed on the handle thereby tensioning a fourth traction wire connected to the distal portion and reforming the distal bend in the distal portion in an opposite direction and in the second plane.

[0094] Example 22 is the method of any one of Examples 15 to 21, further comprising actuating a fourth actuator in a first direction, the fourth actuator being disposed on the handle thereby tensioning a fifth traction wire connected to the distal portion and reforming the distal bend in the distal portion in the first plane.

[0095] Example 23 is a method of any one of Examples 15 to 22, further comprising actuating a fifth actuator in a first direction, the fifth actuator being disposed on the handle thereby tensioning a sixth traction wire connected to the distal portion and reforming the distal bend in the distal portion in an opposite direction and in the first plane.

[0096] Example 24 is the method of any of Examples 15 to 23, further comprising locking the second actuator in place with a lock.

[0097] Example 25 is the method of any one of Examples 15 to 24, further comprising slidably inserting a dilator into the lumen, wherein the dilator comprises a proximal end, a distal end, and a middle portion disposed between the proximal end and the distal end, wherein the middle portion is more flexible than the proximal portion or the distal portion.

[0098] Example 26 is a method of any one of Examples 15 to 25, wherein actuating the first actuator includes moving a rod connected to the first actuator and engaging the rod with the second actuator, thereby causing the second actuator to move in coordination with the first actuator and preventing loosening of the second traction wire.

[0099] Example 27 is the method of any of Examples 15 to 26, further comprising actuating the first actuator in a second direction opposite the first direction, thereby releasing tension on the first traction wire and restoring the proximal bend to an unbiased position.

[0100] Example 28 is the method of any of Examples 15 to 27, further comprising actuating the second actuator in a second direction opposite the first direction, thereby releasing tension on the second traction wire and restoring the distal bend to an unbiased position.

[0101] Example 29 is the method of any one of Examples 15 to 28, further comprising forming a second distal bend simultaneously with the distal bend, the second distal bend being disposed in a third plane transverse to the second plane, thereby allowing unlimited travel of the elongated shaft.

[0102] In Example 30, the apparatus or method of any one or any combination of Examples 1 to 29 may optionally be configured such that all of the listed elements or options may be used or selected therefrom.

[0103] The above detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The accompanying drawings illustrate specific embodiments in which the present invention can be put into practice by way of illustration. These exemplary embodiments are also referred to as "examples" herein. These examples may include elements other than those elements shown or described. However, the inventors have also contemplated examples that only provide those elements shown or described. In addition, the inventors have also contemplated examples of any combination or permutation of those elements (or one or more aspects thereof) shown or described using specific examples (or one or more aspects thereof) shown or described herein or other examples (or one or more aspects thereof) shown or described herein.

[0104] In the event of an inconsistency in usage between this document and any document incorporated by reference, the usage in this document controls.

[0105] In this document, as is common in patent documents, the term "one" or "an" is used to include one or more than one, independent of any other instance or usage of "at least one" or "one or more". In this document, unless otherwise stated, the term "or" is used to refer to a non-exclusive "or", so that "A or B" includes "A but not B", "B but not A" and "A and B". In this document, the terms "including" and "in..." are used as the plain language equivalents of the corresponding terms "comprising" and "wherein". In addition, in the appended claims, the terms "including" and "comprising" are open-ended, that is, the system, device, article, composition, formula, or process in the claim that includes elements other than those listed after these terms is still considered to fall within the scope of the claim. In addition, in the appended claims, the terms "first", "second", and "third", etc. are used only as markers and are not intended to impose numerical requirements on their objects.

[0106] The above description is intended to be illustrative rather than restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments after consulting the above description. An abstract is provided to allow the reader to quickly determine the nature of the present technology disclosure. The abstract is submitted based on the following understanding: the abstract will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description, various features may be combined together to organize the present disclosure. This should not be interpreted as intended to make the disclosed features that are not claimed to be necessary for any claim. On the contrary, the subject matter of the invention may be less than all the features of a particular disclosed embodiment. Therefore, the attached claims are incorporated into the detailed description as examples or embodiments, wherein each claim is alone as a separate embodiment, and it is conceivable that these embodiments may be combined with each other in various combinations or permutations. The scope of the present invention should be determined with reference to the attached claims and the full scope of equivalents given by the claims.

Claims

1. A steerable sheath comprising: an elongated shaft comprising a proximal portion, a distal portion, an intermediate portion disposed between the proximal portion and the distal portion, and a lumen extending between the proximal portion and the distal portion; a first tube coupled to the elongated shaft, the first tube having a lumen extending therethrough; a second tube coupled to the elongated shaft, the second tube having a lumen extending therethrough, Wherein, the elongated shaft is formed of multiple layers of material, the second tube is arranged on the surface of the innermost layer of the elongated shaft, the inner braided layer of the elongated shaft is arranged on the second tube, and then the first tube is arranged on the inner braided layer; a first pull wire having a proximal end and a distal end, the first pull wire extending along the elongated shaft, wherein the first pull wire is disposed in the lumen of the first tube; a second pull wire having a proximal end and a distal end, the second pull wire extending along the elongated shaft, wherein the second pull wire is disposed in the lumen of the second tube, wherein the lumens prevent entanglement of the first traction wire and the second traction wire; a handle coupled to the proximal portion of the elongated shaft; a first actuator, the first actuator being disposed on the handle; and a second actuator, the second actuator being disposed on the handle, wherein the distal end of the first pull wire is coupled to the middle portion of the elongated shaft, and the proximal end of the first pull wire is coupled to the first actuator, wherein the distal end of the second pull wire is coupled to the distal portion of the elongated shaft, and the proximal end of the second pull wire is coupled to the second actuator, wherein actuation of the first actuator in a first direction tensions the first traction wire to form a proximal bend in a first arcuate direction along the middle portion of the elongated axis in a first plane, and wherein actuation of the first actuator in a second direction opposite to the first direction releases the tension of the first traction wire to allow the proximal bend to return to an unbiased configuration, wherein actuation of the second actuator in a first direction tensions the second traction wire, thereby forming a distal bend in a first bending direction along the distal portion of the elongated axis in a second plane, and wherein actuation of the second actuator in a second direction opposite to the first direction of the second actuator releases the tension of the second traction wire, thereby allowing the distal bend to return to an unbiased configuration.

2. The sheath according to claim 1, wherein: The second plane is transverse to the first plane.

3. The sheath of claim 1 , further comprising a pusher rod coupled to the first actuator, and wherein: Actuation of the first actuator in a first direction engages the pusher rod with the second actuator and moves the second actuator in coordination with the first actuator, thereby preventing slackening of the second pull wire.

4. The sheath of claim 1 , further comprising a third pull wire having a proximal end and a distal end, the third pull wire extending along the elongated shaft, in, The distal end of the third pull wire is coupled to the intermediate portion of the elongated shaft at a location opposite the first pull wire, and the proximal end of the third pull wire is coupled to the first actuator, and Wherein, actuation of the first actuator in a second direction opposite to the first direction tensions the third traction wire, so that the proximal curved portion bends along the middle portion of the elongated shaft and in the first plane in a direction opposite to the first arc direction.

5. The sheath of claim 1 , further comprising a fourth pull wire and a third actuator disposed on the handle, the fourth pull wire having a proximal end and a distal end and extending along the elongated shaft, in, The distal end of the fourth pull wire is coupled to the distal portion of the elongated shaft at a location opposite the second pull wire, and the proximal end of the fourth pull wire is coupled to the third actuator, and wherein actuation of the third actuator in a first direction tensions the fourth traction wire so that the distal bend bends along the distal portion of the elongated shaft and in the second plane in a direction opposite to the first bending direction, and Wherein, actuation of the third actuator in a second direction opposite to the first direction of the third actuator releases tension on the fourth traction wire, thereby allowing the distal curve to return to an unbiased configuration.

6. The sheath of claim 5, further comprising a fifth pull wire and a fourth actuator disposed on the handle, the fifth pull wire having a proximal end and a distal end and extending along the elongated shaft, in, The distal end of the fifth pull wire is coupled to the distal portion of the elongated shaft at a location circumferentially offset relative to the second and fourth pull wires, and the proximal end of the fifth pull wire is coupled to the fourth actuator, and wherein actuation of the fourth actuator in the first direction tensions the fifth traction wire so that the distal curved portion bends along the distal portion of the elongated shaft and in the first plane in a second bending direction, and Wherein, actuation of the fourth actuator in a second direction opposite to the first direction of the fourth actuator releases tension on the fifth traction wire, thereby allowing the distal curve to return to an unbiased configuration.

7. The sheath of claim 6, further comprising a sixth pull wire and a fifth actuator, the fifth actuator being disposed on the handle, the sixth pull wire having a proximal end and a distal end and extending along the elongated shaft, in, The distal end of the sixth pull wire is coupled to the distal portion of the elongated shaft at a location opposite the fifth pull wire, and the proximal end of the sixth pull wire is coupled to the fifth actuator, and wherein actuation of the fifth actuator in a first direction tensions the sixth traction wire such that the distal bend bends along the distal portion of the elongated axis and in the first plane in a direction opposite to the second bending direction, and wherein actuation of the fifth actuator in a second direction opposite to the first direction of the fifth actuator releases the tension of the sixth traction wire, thereby allowing the distal bend to return to an unbiased configuration.

8. The sheath according to claim 7, wherein: The second actuator, the third actuator, the fourth actuator, or the fifth actuator includes a slide.

9. The sheath according to claim 8, wherein: The second actuator, the third actuator, the fourth actuator, or the fifth actuator includes a locking member for preventing slidable movement thereof.

10. The sheath according to claim 1, wherein: The proximal curved portion has a radius of curvature, and the distal curved portion has a radius of curvature smaller than the radius of curvature of the proximal curved portion, or the proximal curved portion has a radius of curvature smaller than the radius of curvature of the distal curved portion.

11. The sheath according to claim 1, wherein: The first actuator includes a rotatable wheel threadably engaged with a threaded shuttle, wherein rotation of the rotatable wheel is converted into linear motion of the shuttle.

12. The sheath of claim 1, further comprising a marking or indicator on the first actuator or the second actuator, the marking or indicator configured to identify actuation of the actuator element by a change in shape of the proximal bend or the distal bend.

13. The sheath of claim 1, further comprising a dilator disposed in the lumen of the elongated shaft, wherein: The dilator includes a proximal end, a distal end, and a mid-portion disposed between the proximal and distal ends, wherein the mid-portion is more flexible than the proximal or distal ends of the dilator, thereby facilitating steering of the elongated shaft.

14. The sheath according to claim 1, wherein: The distal bend includes a first distal bend that bends the elongated shaft in the second plane and a second distal bend that bends the elongated shaft in a third plane transverse to the first plane, thereby forming a sheath capable of unlimited traversal.

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