Possibility of manipulation

Abstract

The steerable sheath includes an elongate shaft, a handle, an actuator element on the handle, and a plurality of control wires operably coupled to the elongate shaft and the actuator element. Actuation of the actuator element adjusts the shape of the proximal and distal curves on the elongate shaft. In one embodiment, the steerable sheath further includes a pusher rod coupled to a first actuator, wherein actuation of the first actuator in a first direction engages the pusher rod with a second actuator and moves the second actuator in coordination with the first actuator, thereby preventing slack in the second pull wire.

Description

[Background technology]

[0001] (Priority Claim) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 882,050, filed August 2, 2019 (Attorney Docket No. 5540.001PRV (formerly 5171.001PRV)), the entire contents of which are incorporated herein by reference.

[0002] (background) Many minimally invasive catheter procedures use a guidewire to act as a rail, 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, helping to direct the catheter to the target area. Summary of the Invention [Means for solving the problem]

[0003] Many minimally invasive catheter procedures use a guidewire to act as a rail, over which a sheath can be advanced toward a target treatment area. The sheath facilitates delivery of a therapy or diagnostic device to the target treatment area. That is, the sheath can be used to deliver a therapy or diagnostic agent to the target treatment area. Some sheaths can be pre-curved to match a patient's anatomy and help direct the therapy or diagnostic device to the target area. Many shapes may be required to match various patient anatomies, and thus a large inventory of sheaths may be needed. Furthermore, providing a pre-curved sheath that matches all patient anatomies can be cumbersome. Therefore, it would be preferable to provide a sheath that can accommodate a more diverse set of anatomies.

[0004] Examples of steerable sheaths are disclosed herein, which generally relate to long tubular conduits for delivering diagnostic or therapeutic medical devices, including implants, to a target treatment site. The steerable sheaths disclosed herein may also be used to assist in delivering certain pharmacological agents, such as those in targeted therapy, or diagnostic agents, such as contrast agents. The sheath may optionally have a hemostatic valve, which may be fully closed to prevent any blood loss when inserted into the patient's heart through an artery or vein, or other part of the vascular system, which would result in blood leaking out of the sheath. The sheath may have a handle, with an optional flexible side port attached to an optional three-way stopcock for aspiration and injection of fluids. The handle houses mechanisms connected to pull wires (also referred to herein as control wires) that terminate in pull wiring in the distal section of the sheath. When these mechanisms in the handle are actuated, the distal section of the tubular portion of the sheath will deflect (i.e., bend) in a predictable and controlled manner.

[0005] In the drawings, which are not necessarily drawn to scale, like numbers may describe similar components in different figures. Like numbers with different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. The present invention provides, for example, the following: (Item 1) A steerable sheath, the steerable sheath comprising: an elongate 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 pullwire having a proximal end and a distal end, the first pullwire extending along the elongate shaft; a second pullwire having a proximal end and a distal end, the second pullwire extending along the elongate shaft; a handle coupled to the proximal portion of the elongate shaft; a first actuator disposed on the handle; a second actuator disposed on the handle; Equipped with the distal end of the first pull wire is coupled to the intermediate portion of the elongate shaft and the proximal end of the first pull wire is coupled to the first actuator; the distal end of the second pull wire is coupled to the distal portion of the elongate shaft and the proximal end of the second pull wire is coupled to the second actuator; actuation of the first actuator in a first direction pulls the first pullwire to form a proximal curve in a first arcuate direction along an intermediate portion of the elongate shaft in a first plane, and actuation of the first actuator in a second direction opposite the first direction releases tension in the first pullwire and allows the proximal curve to return to an unbiased configuration; a steerable sheath, wherein actuation of the second actuator in a first direction pulls the second pull wire to form a distal curve in a first curved direction along a distal portion of the elongate shaft in a second plane, and actuation of the second actuator in a second direction opposite the first direction of the second actuator releases the tension in the second pull wire and allows the distal curve to return to an unbiased configuration. (Item 2) Item 2. The sheath of item 1, wherein the second plane is transverse to the first plane. (Item 3) 2. The sheath of claim 1, further comprising a pusher rod coupled to the first actuator, wherein actuation of the first actuator in the first direction causes the pusher rod to engage the second actuator and move the second actuator in coordination with the first actuator, thereby preventing slack in the second pull wire. (Item 4) a third pull wire having a proximal end and a distal end, the third pull wire extending along the elongate shaft; the distal end of the third pull wire is coupled to the intermediate portion of the elongate shaft opposite the first pull wire, and the proximal end of the third pull wire is coupled to the first actuator; 2. The sheath of claim 1, wherein actuation of the first actuator in the second direction opposite the first direction pulls the third pull wire such that the proximal curve curves along the intermediate portion of the elongate shaft in an opposite direction relative to the first arcuate direction within the first plane. (Item 5) a fourth pull wire and a third actuator, the third actuator being disposed on the handle, the fourth pull wire having a proximal end and a distal end and extending along the elongate shaft; the distal end of the fourth pull wire is coupled to the distal portion of the elongate shaft opposite the second pull wire, and the proximal end of the fourth pull wire is coupled to the third actuator; actuation of the third actuator in a first direction pulls the fourth pullwire such that the distal curve curves along the distal portion of the elongate shaft in an opposite direction relative to the first curve direction within the second plane; 2. The sheath of claim 1, wherein actuation of the third actuator in a second direction opposite the first direction of the third actuator releases the tension in the fourth pull wire and allows the distal curve to return to an unbiased configuration. (Item 6) a fifth pull wire and a fourth actuator, the fourth actuator being disposed on the handle, the fifth pull wire having a proximal end and a distal end and extending along the elongate shaft; the distal end of the fifth pull wire is coupled to the distal portion of the elongate shaft at a location circumferentially offset from the second and fourth pull wires, and the proximal end of the fifth pull wire is coupled to the fourth actuator; actuation of the fourth actuator in a first direction pulls the fifth pullwire such that the distal curve curves in a second curvature direction within the first plane along the distal portion of the elongate shaft; 6. The sheath of claim 5, wherein actuation of the fourth actuator in a second direction opposite the first direction of the fourth actuator releases the tension in the fifth pull wire and allows the distal curve to return to an unbiased configuration. (Item 7) 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 elongate shaft; the distal end of the sixth pull wire is coupled to the distal portion of the elongate shaft opposite the fifth pull wire, and the proximal end of the sixth pull wire is coupled to the fifth actuator; 7. The sheath of claim 6, wherein actuation of the fifth actuator in a first direction pulls the sixth pull wire such that the distal curve curves along the distal portion of the elongate shaft in an opposite direction relative to the second curvature direction within the first plane, and actuation of the fifth actuator in a second direction opposite the first direction of the fifth actuator releases the tension in the sixth pull wire and allows the distal curve to return to an unbiased configuration. (Item 8) Item 8. The sheath of item 7, wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator comprises a slider. (Item 9) Item 9. The sheath of item 8, wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator includes a stop to prevent slidable movement thereof. (Item 10) Item 1. The sheath of item 1, wherein the proximal curve has a radius of curvature and the distal curve has a radius of curvature smaller than the radius of curvature of the proximal curve, or the proximal curve has a radius of curvature smaller than the radius of curvature of the distal curve. (Item 11) Item 1 . The sheath of item 1 , wherein the first actuator comprises a rotatable wheel threadedly engaged with a threaded shuttle, wherein rotation of the rotatable wheel is translated into linear motion of the shuttle. (Item 12) 2. The sheath of claim 1, further comprising markings or indicators on the first actuator or the second actuator, the markings or indicators configured to identify actuation of the actuator element with a change in shape of the proximal or distal curve. (Item 13) Item 1. The sheath of item 1, further comprising a dilator disposed within the lumen of the elongate shaft, the dilator having a proximal end, a distal end and a central portion disposed therebetween, the central portion being more flexible than the proximal or distal ends of the dilator, thereby facilitating steering of the elongate shaft. (Item 14) Item 2. The sheath of item 1, wherein the distal curve comprises a first distal curve that curves the elongate shaft in the second plane and a second distal curve that curves the elongate shaft in a third plane transverse to the first plane, thereby forming an infinitely traversable sheath. (Item 15) 1. A method of steering a sheath, the method comprising: providing an elongate shaft having a proximal portion, a distal portion, an intermediate portion disposed between the proximal and distal portions, and a lumen extending between the proximal and distal portions; actuating a first actuator disposed on a handle coupled to the proximal portion of the elongate shaft in a first direction, thereby pulling a first pull wire coupled to the intermediate portion; forming a proximal curve in a first plane at the intermediate portion; actuating a second actuator disposed on the handle in a first direction, thereby pulling a second pull wire coupled to the distal portion; forming a distal curve in a second plane at the distal portion; A method comprising: (Item 16) Item 16. The method of item 15, wherein actuating the first actuator includes rotating a rotatable wheel. (Item 17) Item 16. The method of item 15, wherein actuating the second actuator includes sliding a slider. (Item 18) Item 16. The method of item 15, wherein the first plane is transverse to the second plane. (Item 19) Item 16. The method of item 15, wherein the distal curve has a radius of curvature and the proximal curve has a radius of curvature that is greater than the radius of curvature of the distal curve. (Item 20) Item 16. The method of item 15, further comprising actuating the first actuator in a second direction opposite to the first direction, thereby releasing tension on the first pull wire and pulling a third pull wire coupled to the intermediate section to reform the proximal curve in the first plane in an opposite direction at the intermediate section. (Item 21) Item 16. The method of item 15, further comprising actuating a third actuator disposed on the handle in a first direction, thereby pulling a fourth pull wire coupled to the distal portion to reshape the distal curve in an opposite direction at the distal portion and in the second plane. (Item 22) 22. The method of claim 21, further comprising actuating a fourth actuator disposed on the handle in a first direction, thereby pulling a fifth pull wire coupled to the distal portion to reshape the distal curve in the first plane at the distal portion. (Item 23) 23. The method of claim 22, further comprising actuating a fifth actuator disposed on the handle in a first direction, thereby pulling a sixth pull wire coupled to the distal portion to reshape the distal curve in the first plane in an opposite direction at the distal portion. (Item 24) Item 16. The method of item 15, further comprising locking the second actuator in place with a lock. (Item 25) Item 16. The method of item 15, further comprising slidably inserting a dilator into the lumen, the dilator having a proximal end, a distal end and a central portion disposed therebetween, the central portion being more flexible than the proximal or distal ends. (Item 26) Item 16. The method of item 15, wherein actuating the first actuator includes moving a rod coupled to the first actuator and engaging the rod with the second actuator, thereby moving the second actuator in coordination with the first actuator and preventing slack in the second pull wire. (Item 27) Item 16. The method of item 15, further comprising actuating the first actuator in a second direction opposite the first direction, thereby releasing the tension in the first pull wire and returning the proximal curve to an unbiased position. (Item 28) Item 16. The method of item 15, further comprising actuating the second actuator in a second direction opposite the first direction, thereby releasing tension in the second pull wire and returning the distal curve to an unbiased position. (Item 29) Item 16. The method of item 15, further comprising simultaneously forming a second distal curve disposed in a third plane transverse to the second plane, thereby allowing infinite passage of the elongate shaft. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 illustrates one example of a steerable sheath.

[0007] [Figure 2-1] 2A-2E show examples of curves in the steerable sheath. [Figure 2-2] 2A-2E show examples of curves in the steerable sheath.

[0008] [Diagram 3] FIG. 3 shows one example of an actuator that can be used to control the curvature in the steerable sheath.

[0009] [Figure 4] FIG. 4 shows an exploded view of the handle of FIG.

[0010] [Diagram 5] FIG. 5 shows another example of a handle with an actuator that can be used to control any steerable sheath.

[0011] [Figure 6] FIG. 6 shows an exploded view of the handle of FIG.

[0012] [Figure 7] FIG. 7 shows a side view of the handle of FIG.

[0013] [Figure 8] 8A-8C show one example of an anti-loosening mechanism.

[0014] [Figure 9] 9A-9D show an example of a slider.

[0015] [Figure 10A] 10A-10B show one example of the actuation of the steerable sheath. [Figure 10B] 10A-10B show one example of the actuation of the steerable sheath.

[0016] [Figure 11] FIG. 11 shows one example of a cross section of an elongate shaft within a steerable sheath.

[0017] [Figure 12] FIG. 12 illustrates one example of pull wire routing within a sheath.

[0018] [Figure 13] FIG. 13 shows an example of a pulley.

[0019] [Figure 14] 14A-14B show one example of a variable curvature sheath.

[0020] [Figure 15] 15A-15B show one example of a dilator.

[0021] [Figure 16] FIG. 16 shows one example of a variable stiffness dilator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] 1 illustrates one example of a steerable sheath 100. The sheath 100 includes an elongate shaft 108 having a proximal portion 102, a distal portion 106, and a central or intermediate portion 104 between the proximal portion 102 and the distal portion 106.

[0023] Between the distal portion 106 and the intermediate portion 104 there may be a transition portion having a different durometer than either the distal portion 106 or the intermediate portion 104. For example, the transition portion may have a durometer of about 55 Shore D, which not only helps prevent kinking but also allows for smoother tracking. The transition portion may thus be stiffer than the intermediate portion 104 and less stiff than the proximal portion 102.

[0024] A lumen extends along the length of the elongate shaft and is sized and shaped to slidably receive a therapeutic or diagnostic device. Thus, when positioned, the sheath not only provides a direct pathway to the target treatment area and protects the therapeutic or diagnostic devices as they are advanced to the treatment area, but also prevents them from causing trauma to tissue as they are delivered.

[0025] The proximal portion 102 of the elongated shaft 108 is coupled to a distal end of a handle 118. The handle 118 includes an actuator 110 or actuators that may be operably coupled to the intermediate portion 104 of the elongated shaft 108 such that actuation of the actuator 110 will form a proximal curve in the intermediate portion 104. Here, the actuator may be any mechanism for controlling the proximal curve or curves, but here, the actuator is a rotatable wheel. The handle may also include one or more additional actuators 112, 114, 116 operably coupled to the distal portion 106 of the elongated shaft 108. Actuation of one or more of the actuators 112, 114, 116 will form a distal curve along the distal portion 106 of the elongated shaft. Here, only three additional actuators 112, 114, 116 are shown, although a fourth actuator is also included on the handle but is not visible in this view. The actuators 112, 114, 116 here are sliders, although the actuators can be any mechanism for controlling the distal curve. The handle includes a body sized and shaped for comfortable handling and manipulation by an operator. The proximal end 120 of the handle 118 can include a hemostatic valve, such as a duckbill or Tuohy-Borst valve, which prevents blood or other fluids from exiting the lumen within the sheath and helps to retain a guidewire or other shaft that may be inserted into the catheter lumen. A diagnostic or therapy device can be inserted into the lumen at the proximal end of the handle and advanced through the sheath lumen until it exits the distal end of the sheath positioned adjacent to the target treatment area.

[0026] Optionally, a side port 124 may be coupled to the proximal end 120 of the handle 118, where a stopcock or multi-way stopcock may be used to open and close a fluid path in the side port that is fluidly coupled to the lumen of the sheath. Thus, the side port may be used to introduce fluid into the lumen or to remove fluid, such as blood, from the lumen. A fluid, such as saline, may be used to flush the lumen to remove air from the lumen prior to use, or a therapeutic agent may be introduced into the lumen via the side port and delivered to the treatment area. Additional details regarding actuators and how they form the proximal and distal curves are disclosed below.

[0027] 2A-2E show examples of curves that may be formed in a steerable sheath 200, such as in FIG 1, or any steerable sheath disclosed herein. In FIG 2A, a proximal curve 202 is formed in a first plane and a distal curve 204 is formed in the same first plane. The distal curve has a smaller radius of curvature than the proximal curve.

[0028] In Figure 2B, the proximal curve 202 is formed in a first plane and the distal curve 204 is also formed in the same first plane, but this time the distal curve is in the opposite direction from the distal curve of Figure 2A. The distal curve 204 of Figure 2B has a smaller radius of curvature than the proximal curve 202.

[0029] In Figure 2C, the proximal curve 202 is formed in a first plane (the figure has been rotated relative to Figures 2A-2B for ease of viewing the planes) and the distal curve 204 is formed in a second plane that is transverse to the first plane, which may be orthogonal to the first plane. Thus, the distal curve extends out of the plane in which the proximal curve resides.

[0030] In Figure 2D (a rotation similar to that in Figure 2C), the proximal curve 202 is formed in a first plane and the distal curve 204 is formed in a second plane that is transverse to the first plane, which may be orthogonal to the first plane. This is similar to the example of Figure 2C, except that the distal curve is in the opposite direction to the distal curve in Figure 2C. The distal curve in Figure 2D has a smaller radius of curvature than the proximal curve.

[0031] 2A-2D show the proximal curve in a single direction. However, the proximal curve may also be formed in a second direction opposite the first direction, thereby forming a bidirectional proximal curve. Furthermore, any combination of proximal and distal curves may be formed. For example, the proximal curve may be formed in a first direction or in a second direction opposite the first direction, and the proximal curve in the first or second direction may be in a first plane. The curve forming mechanism of the proximal curve (such as that described herein) may also be replicated, thereby allowing the proximal curve to be formed in a third direction and in a fourth direction opposite the third direction, thereby allowing the formation of a four-way curve (also referred to as a multi-way curve) in the first plane or in a second plane that is orthogonal to or transverse to the first plane. The proximal curve in any of these configurations may be combined with a distal curve that may curve in a first direction, or a second direction opposite the first direction, and the distal curve may lie in a first plane, or a second plane that is transverse to or orthogonal to the first plane. As will be discussed below, different actuators are disclosed that allow for the formation of a variety of proximal and distal curve configurations.

[0032] FIG. 2E shows an example where simultaneously deflecting two or more distal curves in addition to a proximal curve allows the sheath to traverse in an infinite number of planes. Here, a proximal curve 202 is formed in a first plane. A first distal curve 204a is then formed in the same plane as the proximal curve 202. A second distal curve 204b is also formed, bending the distal end of the sheath out of the first plane into a second plane that is transverse to the first plane. Thus, a complex curve is formed, which demonstrates that the sheath can traverse in an infinite number of planes. Although the example of FIG. 2E is achieved with one proximal curve and two distal curves, this can also be accomplished with two proximal curves and one distal curve. Other combinations of curves are also possible to provide an infinitely traversable sheath.

[0033] FIG. 3 illustrates one example of an actuator that may be used to control the curves 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 between the proximal and distal portions (not shown). 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 rotation of the wheel converts rotational motion to linear motion with a first linear screw (also referred to herein as a shuttle) in the handle, as will be discussed in more detail below. Each actuator may have one pull wire coupled to a shuttle such that rotation of the wheel applies tension to a pull wire also coupled to the distal or intermediate portion of the elongated shaft 302, thereby bending the distal or intermediate portion and forming the distal or proximal curve described in FIGS. 2A-2E above. The actuator may also have a second linear screw (also referred to herein as a shuttle) that is parallel to the first linear screw. A second pull wire is then coupled to the second shuttle, typically also coupled to a distal or intermediate portion of the elongated shaft at the same axial location as the first pull wire, but circumferentially offset about 180 degrees away from the connection point of the first pull wire. Thus, actuation of the first pull wire bends the elongated shaft in a first direction in a first plane, and actuation of the second pull wire bends the elongated shaft in the opposite direction in the first plane. The threads on the second shuttle may be the opposite of the threads on the first shuttle, such that rotation of the wheel causes one shuttle to move in one direction while the second shuttle moves in the opposite direction, thereby controlling both pull wires simultaneously.

[0034] The second actuator 306 generally takes the same form as the first actuator 304, with one or two pull wires attached to either the intermediate or distal portion of the elongate shaft, although in this example there are two pull wires, each attached to the distal portion of the elongate shaft. Rotation of the second wheel pulls the first pull wire, thereby bending the distal portion of the elongate shaft into a distal curve in a first plane, and rotation of the second wheel in the opposite direction pulls the second pull wire, thereby bending the distal curve in the opposite direction in the first plane. The two pull wires are coupled to the distal portion of the elongate shaft and are circumferentially offset from one another, such as offset by 180 degrees. Two shuttles, each with opposite threads to the other shuttle, are also included, whereby actuation of the wheels moves the shuttles in opposite directions (one forward and the other backward).

[0035] The third actuator 308 generally takes the same form as the first and second actuators 304, 306, with one or two pull wires attached to either the intermediate or distal portion of the elongated shaft, although in this example there are two pull wires, each attached to the distal portion of the elongated shaft. Rotation of the third wheel pulls the first pull wire, thereby bending the distal portion of the elongated shaft into a distal curve in a second plane, and rotation of the second wheel in the opposite direction pulls the second pull wire, thereby bending the distal curve in the opposite direction in the second plane. The second plane may be orthogonal to (or transverse to) the first plane. Two pull wires are coupled to the distal portion of the elongated shaft and are circumferentially offset from each other, such as offset by 180 degrees. They are also circumferentially offset from the two pull wires in the second actuator. Thus, for example, four pull wires in the second and third actuators may be coupled to the distal portion of the elongate shaft at the same axial location, but circumferentially offset from one another by 90 degrees. This is not intended to be limiting, and any angular distance may be used. Two shuttles may also be used, each having an opposite thread to the other, such that actuation of the wheels moves the shuttles in opposite directions (one forward, the other backward). Additional figures and details illustrating actuation of the rotatable wheels and pull wires are provided below.

[0036] The proximal end of the handle 310 may include a window 316 that allows the operator to see inside the handle and determine if any air bubbles are present. Alternatively, part or all of the handle assembly may be made from a transparent material that allows the operator to screen for the accidental introduction of air bubbles. If applicable, air bubbles may be flushed or aspirated using a side port 312 fluidly coupled to the elongated shaft lumen. A stopcock (one-way or multi-way) may be coupled to the side port to control fluid flow. A hemostatic valve 314, such as a duckbill valve or Tuohy-Borst valve, may be used to prevent blood from flowing out of the lumen within the sheath.

[0037] Figure 4 shows an exploded view of the handle 300 of Figure 3. Here, the actuators 304, 306, 308 have upper and lower rotatable wheel halves clamped around the handle. The inner surface of each upper and lower rotatable wheel 304, 306, 308 is threaded, whereby circular rotation of the wheel is translated into linear motion of each shuttle 334, 336, where each actuator 304, 306, 308 includes two shuttles, where rotation of the wheel moves one shuttle distally while the other shuttle moves proximally. Rotation of the wheel in the opposite direction moves the shuttles in the opposite direction, thus where one shuttle moves proximally while the other moves distally. The threads can be standard helical threads, or here the threads are diamond-shaped protrusions 342, where the four sides of the diamond provide a sloping surface with a bend, whereby the slope of the bevel changes from positive to negative or negative to positive. Thus, when the diamond-shaped protrusions interface with the threads on the shuttle, the rotation of the wheel will be translated into linear motion of the shuttle along the shaft 330. A pull wire (not shown in this figure) is attached to each shuttle, so that movement of the shuttle applies or releases tension to the pull wires, thereby forming a proximal or distal curve in the elongated shaft. The hubs 338, 340 (here three hubs) have openings disposed therethrough, and the pull wires can pass through the hubs, as will be shown in more detail herein. The hubs also serve to secure the rotatable wheels. The shaft 330 includes a central lumen 332 that is fluidly coupled with a lumen in the sheath. The proximal portion of the handle 310 may include a window to allow visualization of air bubbles within the lumen (or a transparent handle, as disclosed above), and a side port or hemostatic valve as shown in FIG.

[0038] FIG. 5 shows another example of a handle 500 with actuators that 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 actuation of the actuators 504, 506 can be used to form any of the proximal or distal curves 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 that disclosed above and includes a short length of tubing coupled to the proximal end of the handle 500 and is fluidly coupled to a lumen of the elongated shaft of the steerable sheath, allowing for the introduction or removal of fluids into or from the lumen. A one-way or multi-way stopcock can be coupled to the free end of the side port tubing to control fluid flow. The hemostasis valve 514 may be a duckbill valve, a Tuohy-Borst valve, or other valve that allows the introduction of a catheter or other device into the handle while controlling the flow of fluids such as blood out of the proximal end of the handle. The hemostasis valve may be used to help retain a guidewire or elongate shaft within the handle and prevent migration when the hemostasis valve is tightened, e.g., when using a Tuohy-Borst valve.

[0039] The distal-most actuator 504 may be an actuatable wheel that the operator rotates to control the proximal curve in the steerable sheath. Similar to the example of FIG. 4, the rotational movement of the actuatable wheel is translated into linear motion of one, two, or more shuttles attached to pull wires connected to an intermediate portion of the elongated shaft. Thus, rotation of the wheel in a first direction pulls on the first pull wire to form a proximal curve along the intermediate portion of the steerable sheath in a first direction and in a first plane, while rotation of the wheel in the opposite direction releases tension on the first pull wire, allowing the proximal curve to return to an unbiased configuration, and further actuation of the wheel then tensions an optional second pull wire (if a second shuttle is present), which then forms a proximal curve in a second direction opposite the first direction and in the same first plane. Additional disclosure regarding the pull wire configurations and attachment to the steerable sheath is provided below.

[0040] Additional actuators 506 are also coupled to the handle, and in this example there are four additional actuators 506. Two are visible in this view and the other two are not. Here, the actuator 506 includes a textured distal angled portion 508 on the distal end of the actuator and a proximal angled portion 510 slidably coupled to the distal angled portion 508. Pushing the proximal angled portion 510 distally lifts the proximal-most end of the proximal angled portion 510 upward and away from the rack (located in the handle and not visible in this view). This causes the teeth coupled to the proximal angled portion to disengage from the rack, allowing the slider to be advanced distally. Distal advancement allows for release of tension on the pull wire coupled to the slider and a distal portion of the elongated shaft of the steerable sheath, thereby allowing the distal curve to return to the unbiased configuration.

[0041] Proximal retraction of the proximal angled portion 508 draws the slider proximally along the rack as it is retracted proximally, since the teeth are curved to form a cam surface that easily slides over the rack. Proximal retraction of the proximal angled portion 508 moves the slider proximally, which applies tension to a pull wire connected to it, which then forms a distal curve in the distal portion of the elongated shaft of the steerable sheath. This curve may be in the same first plane as the proximal curve, or it may be in a second plane that is transverse to or perpendicular to the first plane. A second slider may be positioned on the handle offset circumferentially, so that it is offset approximately 180 degrees, and the second slider may be used to form a distal curve in the opposite direction to the first direction and in the same plane. Two additional sliders may also be included on the handle to form a distal curve in either a first direction or a second direction opposite the first direction, and either in the first plane or in a second plane transverse to or orthogonal to the first plane. Thus, for example, if there are four sliders, two sliders form a distal curve in a first plane (the same plane as the proximal curve) in the first or second opposite directions, and the other two sliders form a distal curve in a second plane orthogonal to or transverse to the first plane in the first or second opposite directions. Each slider is attached to a pull wire, and thus there may be four pull wires, which may be coupled to the distal portion of the elongate shaft of the sheath at positions circumferentially offset by, for example, 90 degrees, with cooperating pairs of pull wires offset by 180 degrees. Additionally, deflecting two or more of the distal curves simultaneously in addition to the proximal curve allows the sheath to traverse an infinite number of planes, as seen above in Figure 2E, i.e., deflecting two or more proximal curves simultaneously with one distal curve also allows for an infinitely traversable sheath.

[0042] FIG. 6 shows an exploded view of the handle of FIG. 5 to more clearly illustrate the operation of the actuator. As disclosed above, the handle 500 includes a slider 506 with proximal and distal portions 510, 508 for locking, unlocking, advancing, and retracting the slider along a rack 604 with teeth. Teeth 602 on the bottom of the proximal portion 510 engage with teeth on the rack 604. When the proximal portion 510 of the slider is pushed distally, it lifts the proximal portion of the slider upwards, disengaging the teeth 602 from the teeth on the rack 604. A spring disposed between the proximal and distal portions is biased to push the proximal portion back downwards, whereby the teeth 602 engage with teeth in the rack 604, locking the slider and preventing distal movement. This will be explained in more detail below. Here, the handle 500 includes four sliders. Two sliders are visible in this view, while the other two are not. The sliders slide along channels in the handle body to ensure smooth linear motion. A pull wire is attached to each slider, which then extends distally along the handle through holes 620, 614 in the hubs 618, 610, with the distal ends of the pull wires coupled to a distal portion of the elongate shaft.

[0043] The distal-most actuator includes a rotatable wheel 504 in two halves arranged around a shuttle 608 (also referred to as a lead screw), which converts rotational motion into linear motion. Threads 606 on the inner surface of the wheel 504 engage mating threads on the shuttle 608, which slides on a shaft 616 having a square or rectangular cross-section. Because the shuttle cannot rotate around the shaft 616, rotation of the wheel 504 is converted into linear motion of the shuttle 608 along the shaft 616. A pull wire is attached to the distal portion of the shuttle, which may pass through an opening 614 in a hub 610, the free end of which is then coupled to an intermediate portion of the elongated shaft of the steerable sheath. The hubs 618, 610 may constrain the rotatable wheel so that it can only rotate, preventing linear motion of the wheel. The hubs 618, 610 also help secure the components together. Openings 620, 614 in the hubs 618, 610 also allow the pull wires to pass through the hubs unobstructed and prevent tangling of the pull wires. A distal cap 612 seals the distal end of the handle. A cylindrical rod with teeth extends proximally from the shaft 616, which serves as a rack 604 on which the slider moves. Teeth 602 on each slider 506, when engaged with teeth on the rack, prevent the slider from moving distally, which locks the slider in place, thereby retaining tension in the pull wires and the curve formed by them. Proximal movement is not inhibited by the teeth's engagement with the teeth on the rack. This locking mechanism is described in more detail below. 6 shows a rotatable wheel with only a single shuttle 608, however, that is not intended to be limiting and a second shuttle may be added to control a second pull wire coupled to an intermediate portion of the elongate shaft of the sheath. The threads on the second shuttle may be the opposite of the threads of the first shuttle such that rotation of the wheel causes one shuttle to move proximally while the second shuttle moves in the opposite direction, distally.Alternatively, the threads on the shuttles may be the same, so that both shuttles move in the same direction when actuated by the wheel.

[0044] Figure 7 shows a side view of the handle 500 of Figure 6, which operates in the same manner as described above. Figure 7 shows a single shuttle 608 and also shows the engagement of teeth 602 with teeth on the rack 604. The two sliders 506 are shown circumferentially offset from one another, again offset by 180 degrees, which may serve as an indicator to the operator of the direction in which each slider controls bending, but this is not intended to be limiting and the sliders may be spaced in any desired configuration.

[0045] 8A-8C show another example of a handle similar to that of FIGS. 6-7, with the major difference being the addition of an optional anti-slack feature. As actuation of the rotatable wheel forms a curve in one portion, e.g., the middle portion, of the elongated shaft of the steerable sheath, the shaft forms a rounded curve, which results in slack in the pull wires coupled to the slider. When the sliders are actuated, the sliders must first be moved to remove excess slack before they can pull on their respective pull wires and form a curve in the other portion of the elongated shaft of the steerable sheath. Thus, the addition of the anti-slack feature removes slack from the slider pull wires when the rotatable wheel actuates them, and thus actuation of the slider maintains close correspondence with the formation of the curve in the steerable sheath and does not require that slack be removed.

[0046] FIG. 8A shows the distal-most actuator, which includes a rotatable wheel 504 with a moving shuttle 608 that slides along a shaft 616. The handle 800 also includes a slider 506 with proximal and distal slider portions 508, 510 and a locking tooth 602 that releasably engages a tooth 820 in a rack. The operation of the distal-most actuator and slider is the same as already described above in FIGS. 6-7. The release mechanism includes a pusher 806, such as a hypotube or other tube-like tube, coupled to the proximal end of the shuttle 608. A pull wire connected to the slider may pass freely through the hypotube 806 so as not to interfere with the actuation of the distal curve. As the shuttle 608 moves proximally, the pusher 806 contacts the distal end of the slider 506 and continues the proximal movement of the shuttle, correspondingly pushing the slider 506 proximally, thereby eliminating any slack in the pull wires coupled to that slider. Thus, as the slider is retracted proximally, pulling on its respective pull wire, tension is instantly applied, since there is no slack in the pull wires and the resulting control of the curve corresponds closely to the actuation of the slider. As the shuttle is moved distally in the opposite direction, the pusher 806 disengages from the slider, and the slider can be moved distally. This anti-slack feature can be used in any of the handle examples disclosed herein. FIG. 8A shows only two sliders, but a total of four sliders can be included, the other two not visible in this view. Additionally, while only a single shuttle is shown with the anti-loosening feature, a second shuttle may also be added, with or without the anti-loosening feature. The anti-loosening feature may include two pushers per shuttle, which may contact and push the two sliders, so that when two shuttles are present, loosening may be avoided in all four pull wires coupled to the sliders. The pull wires 802 coupled to the sliders may extend through channels or lumens in the pushers and pass through the hubs 618, 610 and openings in the shuttles, as described above.A pull wire 804 may be coupled to the shuttle 608 and pass through an opening in the shuttle and distal hub 610. Other aspects of FIG. 8A are generally the same as the handle of FIGS. 6-7.

[0047] Figure 8B shows a top view of the handle of Figure 8A, highlighting pusher 806 coupled to the proximal end of shuttle 608 and brought into contact with slider 506. Here, a single pusher is shown, but one skilled in the art will understand that a pusher may be coupled to each shuttle to push the corresponding slider. In this view, the rotatable wheel has been removed to highlight shuttle 608. Other aspects of Figure 8B are generally the same as in Figure 8A.

[0048] Figure 8C shows a side view of the handle 800 of Figures 8A-8B. The other sides of the handle are generally the same as in Figures 8A-8B.

[0049] 9A-9D show some examples of sliders that can be used in any of the handles disclosed herein. FIG. 9A shows slider 900, which includes a proximal slider portion 904, a distal slider portion 902, a spring 906, teeth 908, and a hinge or pivot 910. As already discussed above, proximal portion 904 includes a sloped portion that is configured for easy actuation by thumb or finger and controls locking of the slider. Distal portion 902 also includes a sloped portion, which can be textured or knurled so that a finger or thumb can easily grip and move the proximal slider portion. A hinge or pin and pivot 910 join the two halves of the slider together, so that they can pivot relative to each other. A spring 906 is coupled to both portions of the slider and biased to push the two halves away from each other so that both slider halves are flat and generally collinear with each other. This ensures that the teeth 908 engage the teeth on the rack in the handle. The teeth 908 include a flat distal surface that prevents distal actuation of the slider mechanism 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 allow the teeth 908 to disengage from the teeth in the rack and the slider to be advanced distally). The teeth 908 also have a curved shape on the proximal end that acts as a cam such that when the slider is pushed proximally, the cam slides smoothly over the teeth on the rack and proximal movement of the slider is unimpeded.

[0050] FIG. 9B shows a perspective view of the slider of FIG. 9A.

[0051] 9C shows an example of teeth on a rack 920 of any of the handles disclosed herein, into which teeth 908 on the slider may engage. The teeth have an angled leading edge that allows the cam-like surface of the teeth 908 to slide easily during proximal retraction of the slider, and a vertical trailing edge that engages the slider and prevents distal slider movement unless the teeth disengage from the teeth on the rack, as disclosed above with respect to FIG. 9A.

[0052] FIG. 9D shows slider 900 engaged with teeth 920 on rack 920 .

[0053] 10A-10B show some examples of steerable sheath actuation using rotatable wheel actuators and slider actuators, such as those disclosed in FIGS. 5-7. In FIG. 10A, 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 coupled to the handle 1020. The handle 1020 includes two actuators, such as rotatable wheels 1010, and a slider 1018. A hemostatic valve 1022, such as a duckbill valve or Tuohy-Borst valve, is included on the proximal end of the handle to prevent fluid leakage and to secure a guidewire, catheter, or other elongated instrument that may be slidably positioned within the lumen of the steerable sheath. A proximal ring 1004 and a distal ring 1002 are coupled to the elongated shaft and serve as connection points for pull wires. For example, here a distal ring 1002 is coupled to a distal portion of the elongate shaft and a proximal ring 1004 is coupled to a middle or central portion of the elongate shaft disposed between the proximal and distal portions of the elongate shaft. A pull wire 1016 is coupled to the distal ring 1002 and to a slider 1018, and another pull wire 1008 is coupled to the proximal ring 1004 and to a shuttle 1012. Rotation of the rotatable wheel 1010 is translated into linear motion of the shuttle 1012. Thus, actuation of the rotatable wheel controls bending of the middle portion of the elongate shaft to form a proximal curve, and actuation of the slider controls bending of the distal portion of the elongate shaft to form a distal curve. In addition, a pusher 1014 is also coupled to the shuttle 1012, whereby as the shuttle 1012 moves proximally it moves the pusher 1014 proximally into contact with the slider 1018, pushing the slider back in coordination with the rotation of the wheel 1010. Thus, as the slider is pushed proximally by the pusher 1014, tension in the pullwire 1008 is increased and any resulting slack in the pullwire 1016 is taken up as the proximal curve is formed. Thus, when the slider 1018 is actuated, the slider will not require proximal retraction to take up slack before the pullwire controls the distal curve.Actuation of the slider will result in an immediate response of the distal curve. Although the example of FIG. 10A shows only a single shuttle, one skilled in the art will understand that two or more shuttles may be used as already disclosed above. Additionally, although FIG. 10A shows only a single slider, that is not intended to be limiting, and two, or three, or four, or more sliders may also be used to control the distal curve in any number of other directions, such as those in FIGS. 5-7. Alternatively, controlling multiple sliders at various locations allows the sheath to be steered in any number of other directions.

[0054] FIG. 10B shows actuation of the rotatable wheel 1010 to move the shuttle 1012 proximally, thereby forming a proximal curve in the middle portion of the elongated shaft 1006 of the steerable sheath. If a second shuttle is included within the rotatable wheel 1010, actuation of the wheel in the opposite direction will form a proximal curve in the opposite direction, but in the same plane, which would be offset approximately 180 degrees if a second pullwire (not shown) is coupled to the proximal ring at a location circumferentially offset from the first pullwire. FIG. 10B also shows a pusher 1014 that is brought into contact with the slider, pushing it proximally and removing slack from the pullwire 1016. The slider can be the same as in FIGS. 9A-9D with a stop to prevent unwanted movement.

[0055] FIG. 11 shows a cross section of an elongate shaft 1102 of a steerable sheath. The elongate shaft 1102 may be formed from several layers of material, for example, an innermost layer 1106 that forms the lumen for the steerable sheath may be a layer of polytetrafluoroethylene (PTFE) tubing to provide a smooth surface. Then, one, or two, or three, or four, or more small diameter tubes 1112, such as polyimide or PTFE tubes, are placed on top of the surface of the innermost layer 1106, which form the lumen for the distal curved pull wires. The number of tubes used depends on the number of pull wires used. Here, four tubes are used to accommodate four pull wires. The tubes are spaced approximately every 90 degrees, but that is not a limitation and any desired spacing may be used. An inner braided layer 1104 is then placed over the tube 1112, and then one, two, three, four, or more other small diameter tubes 1114, such as polyimide, PTFE, or other fluoropolymer tubes, are placed over the inner braid 1104. The tubes 1114 provide lumens for the proximal curved pullwires, and here there are two tubes 1114 that are circumferentially offset by 180 degrees. Any positioning can be used, and the number of tubes depends on the number of proximal curved pullwires. An outer braid 1110 is placed over the proximal curved pullwires, and a final outer polymer layer 1108 is placed over everything. Thus, each pullwire is slidably positioned within a separate lumen to ensure that actuation of each pullwire is smooth, friction is reduced, and to avoid tangling of the pullwires.

[0056] 12 shows an example of how pull wires may be routed through the elongate shaft 1202 of any of the steerable sheaths disclosed herein as a way to address slack in some pull wires that may result as the sheath is curved into different configurations. The pull wires may be routed in a linear fashion through the elongate shaft and parallel to the longitudinal axis of the elongate shaft, or in any of the examples where the pull wire routing may be modified to minimize slack, pull wire ring 1204 is coupled to a distal portion of the elongate shaft to control the distal curve and pull wire ring 1206 is coupled to an intermediate portion of the elongate shaft to control the proximal curve.

[0057] If the proximal bidirectional curve were in the plane of the page, the two pull wires 1218, 1220 that control the distal curve in the same plane would experience slack or tension. To prevent that from happening, these pull wires 1218, 1220 are routed through channels in the proximal pull wire ring 1206. The distal curve in-plane pull wires 1218, 120 are then circumferentially offset from their original axis and re-routed along a path that defines a plane that is orthogonal or transverse to the plane of the proximal curve. This can be accomplished by offsetting the pull wires 1218, 1220 approximately 90 degrees from their initial axis. When the proximal curve is actuated, slack or tension in the re-routed pull wires is thus minimized.

[0058] In this example, two pull wires 1208, 1210 run linearly and parallel to the elongate shaft, and both are coupled to a pull wire ring 1206 proximal to the pull wire ring 1204. The connection points 1214, 1216 are offset circumferentially by approximately 180 degrees in this example. Two additional pull wires 1218, 1220 also run linearly and parallel to the longitudinal axis of the elongate shaft, but the pull wires 1218, 1220 are then re-routed (1222) adjacent to the pull wire ring 1206. Both pull wires then continue to run linearly and parallel to the elongate shaft until they are attached (1224, 1226) to a pull wire ring 1204 distal to the pull wire ring 1206. The connection points are offset circumferentially by approximately 180 degrees from each other. Rerouting the pull wires can help control the tension and slack in the pull wires and can provide better control of deflection and bending.

[0059] FIG. 13 shows an example of the use of pulleys to facilitate manipulation of pull wires in any of the examples of steerable sheaths disclosed herein. An elongated shaft 1316 is coupled to the handle 1302. Pull wires 1310, 1312 are coupled to the elongated shaft and also coupled (1314) to the handle 1308. A pulley 1306 is operatively coupled to the pull wires 1310, 1312, thereby providing a mechanical advantage when the pulley is actuated as shown by arrow 1304. The use of a pulley configuration allows for very responsive deflection with 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 pull wires with pulleys, however, that is not intended to be limiting and one pull wire may have a pulley while the other pull wire does not. In examples having more than two pull wires, one pulley may be used with any number of those pull wires.

[0060] 14A-14B show one example of a variable curvature sheath 1400. The device includes an inner stiff shaft 1402 slidably disposed within a sheath 1404. A curve is preset in the inner shaft 1402. When the inner shaft 1402 is advanced through the outer shaft 1404 and the distal portion of the inner shaft 1402 becomes unconstrained by the outer sheath 1404, the distal portion of the inner shaft 1402 will begin to bend to its unbiased natural curve 1406. The radius of curvature of the curve 1406 depends on the amount of the distal portion that is exposed. In FIG. 14A, a relatively large portion of the distal end of the inner shaft is unconstrained and therefore the curve will have a relatively large bend radius.

[0061] In FIG. 14B, a shorter section of the distal end of the inner shaft is unconstrained, and therefore the curve will have a smaller 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 curve will facilitate delivery to the target treatment area. Handles can be coupled to the inner and outer shafts and sheaths to help control the relative motion. The variable curvature sheath can be used with any of the other actuation mechanisms to further control the curve in the steerable sheath.

[0062] 15A-15B illustrate a dimpled dilator that may be used with any of the steerable sheaths disclosed herein. In FIG. 15A, the dilator 1502 includes an elongate shaft with a tapered distal atraumatic tip 1504 and a hub or other connector on the proximal end 1508 of the dilator. Dimples, or annular grooves 1506, arranged circumferentially around the distal portion of the dilator provide a receptacle for receiving the distal tip of the steerable sheath resulting in a better and smoother dilator-sheath transition.

[0063] In FIG. 15B, a dilator 1502 has been inserted into any of the steerable sheaths disclosed herein. The distal tip of the steerable sheath is formed from a resilient material that is biased to collapse to a diameter smaller than the diameter of the main section of the sheath. Thus, as the dilator is slidably advanced through a lumen within the sheath, the distal end 1512 of the sheath is caused to remain in its larger diameter configuration. However, once the dilator is advanced far enough that the distal end of the sheath 1512 reaches the annular groove 1506, the distal end of the sheath 1512 will collapse to its unbiased smaller diameter and collapse into the annular groove, thereby shielding the leading edge of the sheath within the groove and providing a smooth transition from the dilator to the sheath without a bumpy or discontinuous transition.

[0064] FIG. 16 illustrates one example of a variable stiffness dilator that may be used with any of the steerable sheaths disclosed herein. The dilator 1602 includes a tapered distal atraumatic tip 1606 and a hub or other connector 1612 on the proximal end. The elongated shaft of the dilator may be divided into a proximal portion 1610, a distal portion 1604, and a central or intermediate portion 1608 disposed between the proximal and distal portions. The dilator may be manufactured such that the elongated shaft has any desired stiffness profile along the elongated shaft. For example, the intermediate portion 1608 may be softer and more resilient than the proximal or distal portions 1610, 1604. When the dilator is inserted into any of the steerable sheaths disclosed herein, the softer intermediate portion will therefore bend (and flex) more easily as the steerable sheath is bent. The proximal portion may be the stiffest to provide pushability for the dilator during delivery, while the distal portion may be the same stiffness as the proximal portion may be softer or otherwise adjusted as desired to provide sufficient stiffness to push against tissue without causing unnecessary trauma to the tissue. Any durometer may be used in the proximal, distal, or intermediate portions of the dilator shaft. Thus, the steerable sheath may be steered with a dilator disposed within the steerable sheath.

[0065] In any of the examples of steerable sheaths disclosed herein, the pull wires may be made from any number of different materials. For example, rounded or flattened metal wires, such as stainless steel, or high strength polymer filaments, such as Kevlar, may be used.

[0066] In any of the examples of steerable sheaths disclosed herein, the braided layer (such as that in FIG. 11) may be made from any number of different materials. For example, rounded or flat metal wires such as stainless steel or Nitinol can be used to avoid kinking. Alternatively, high strength monofilament polymers such as polyetheretherketone (PEEK) or multifilaments such as Kevlar and Vectran can be used, which are non-magnetic.

[0067] In any of the examples of steerable sheaths disclosed herein, the sheath may have any diameter or length. For example, sheaths ranging from 8.5 to 15.5 French may be used. Similarly, the radii of curvature of the proximal and distal curves may be any radius required for a particular procedure or anatomy.

[0068] In any of the examples of steerable sheaths disclosed herein, any of the actuators may include indicia such as printing, markings, colors, etc. to indicate to an operator which actuator controls which direction of which curve.

[0069] In any of the examples of steerable sheaths disclosed herein, the proximal and distal portions of the elongate shaft of the steerable sheath may have any desired length, which may be based on the procedure or anatomy being performed. For example, the distal portion of the steerable sheath may have a distal portion at which a distal curve is formed, which may be the distal-most 2-4 centimeters of the elongate shaft. Similarly, the intermediate portion of the elongate shaft at which a proximal curve is formed may be the next 4-10 centimeters of the elongate shaft proximal to the distal portion. Notes and Examples

[0070] The following non-limiting examples detail certain aspects of the present subject matter to, inter alia, solve the problems and provide the benefits discussed herein.

[0071] Example 1 is a steerable sheath comprising an elongate 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, a first pull wire having a proximal end and a distal end extending along the elongate shaft, a second pull wire having a proximal end and a distal end extending along the elongate shaft, a handle coupled to the proximal portion of the elongate shaft, a first actuator disposed on the handle, and a second actuator disposed on the handle, wherein a distal end of the first pull wire is coupled to the intermediate portion of the elongate shaft, a proximal end of the first pull wire is coupled to the first actuator, and a distal end of the second pull wire is coupled to the distal portion of the elongate shaft. a proximal end of the second pull wire is coupled to the intermediate portion of the elongate shaft, and a proximal end of the second pull wire is coupled to a second actuator, actuation of the first actuator in a first direction pulls the first pull wire to form a proximal curve in a first arcuate direction along the intermediate portion of the elongate shaft in a first plane, actuation of the first actuator in a second direction opposite the first direction releases tension in the first pull wire to allow the proximal curve to return to the unbiased configuration, actuation of the second actuator in the first direction pulls the second pull wire to form a distal curve in a first arcuate direction along the distal portion of the elongate shaft in the second plane, actuation of the second actuator in a second direction opposite the first direction of the second actuator releases tension in the second pull wire to allow the distal curve to return to the unbiased configuration.

[0072] Example 2 is the sheath of Example 1, where the second plane is transverse to the first plane.

[0073] Example 3 is a sheath described in any of Examples 1-2, further comprising a pusher rod coupled to a first actuator, 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 loosening of the second pull wire.

[0074] Example 4 is the sheath of any of Examples 1-3, further comprising a third pull wire having a proximal end and a distal end, the third pull wire extending along the elongate shaft, the distal end of the third pull wire being coupled to an intermediate portion of the elongate shaft at a location opposite the first pull wire, and the proximal end of the third pull wire being coupled to a first actuator, wherein actuation of the first actuator in a second direction opposite the first direction pulls the third pull wire such that the proximal curve curves in an opposite direction to the first arcuate direction along the intermediate portion of the elongate shaft and within the first plane.

[0075] Example 5 is the sheath of any of Examples 1-4, further comprising a fourth pull wire and a third actuator, the third actuator being disposed on the handle, the fourth pull wire having a proximal end and a distal end extending along the elongate shaft, the distal end of the fourth pull wire being coupled to a distal portion of the elongate shaft at a location opposite the second pull wire, the proximal end of the fourth pull wire being coupled to the third actuator, actuation of the third actuator in a first direction pulls the fourth pull wire such that the distal curve curves along the distal portion of the elongate shaft and in a second plane in an opposite direction relative to the first curvature direction, and actuation of the third actuator in a second direction opposite the first direction of the third actuator releases tension on the fourth pull wire and allows the distal curve to return to an unbiased configuration.

[0076] Example 6 is the sheath of any of Examples 1-5, further comprising a fifth pull wire and a fourth actuator, the fourth actuator disposed on the handle, the fifth pull wire having a proximal end and a distal end extending along the elongate shaft, the distal end of the fifth pull wire coupled to a distal portion of the elongate shaft at a position circumferentially offset from the second and fourth pull wires, the proximal end of the fifth pull wire coupled to the fourth actuator, actuation of the fourth actuator in a first direction pulls the fifth pull wire such that the distal curve curves in a second curvature direction along the distal portion of the elongate shaft and within the first plane, and actuation of the fourth actuator in a second direction opposite the first direction of the fourth actuator releases tension on the fifth pull wire and allows the distal curve to return to an unbiased configuration.

[0077] Example 7 is the sheath of any of Examples 1-6, 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 extending along the elongate shaft, the distal end of the sixth pull wire being coupled to a distal portion of the elongate shaft at a location opposite the fifth pull wire, the proximal end of the sixth pull wire being coupled to the fifth actuator, actuation of the fifth actuator in a first direction pulls the sixth pull wire such that the distal curve curves along the distal portion of the elongate shaft and in an opposite direction relative to a second curvature direction within the first plane, and actuation of the fifth actuator in a second direction opposite the first direction of the fifth actuator releases tension on the sixth pull wire and allows the distal curve to return to an unbiased configuration.

[0078] 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 slider.

[0079] Example 9 is a sheath described in any of Examples 1-9, wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator includes a locking portion to prevent slidable movement thereof.

[0080] Example 10 is a sheath described in any of Examples 1-9, wherein the proximal curve has a radius of curvature and the distal curve has a radius of curvature smaller than the radius of curvature of the proximal curve, or the proximal curve has a radius of curvature smaller than the radius of curvature of the distal curve.

[0081] Example 11 is a sheath described in any of Examples 1-10, wherein the first actuator comprises a rotatable wheel that is threadedly engaged with the threaded shuttle, and rotation of the rotatable wheel is translated into linear motion of the shuttle.

[0082] Example 12 is a sheath described in any of Examples 1-11, further comprising a marking or indicator on the first actuator or the second actuator configured to identify actuation of the actuator element with a change in the shape of the proximal curve or the distal curve.

[0083] Example 13 is a sheath described in any of Examples 1-12, further comprising a dilator disposed within the lumen of the elongate shaft, the dilator having a proximal end, a distal end, and a central portion disposed therebetween, the central portion being more flexible than the proximal or distal ends of the dilator, thereby facilitating steering of the elongate shaft.

[0084] Example 14 is a sheath described in any of Examples 1-13, wherein the distal curve comprises a first distal curve that curves the elongate shaft in a second plane and a second distal curve that curves the elongate shaft in a third plane transverse to the first plane, thereby forming an infinitely traversable sheath.

[0085] Example 15 is a method of steering a sheath, the method including providing an elongate shaft having a proximal portion, a distal portion, an intermediate portion disposed between the proximal and distal portions, and a lumen extending between the proximal and distal portions; actuating a first actuator disposed on a handle coupled to the proximal portion of the elongate shaft in a first direction, thereby pulling a first pull wire coupled to the intermediate portion and forming a proximal curve in a first plane at the intermediate portion; and actuating a second actuator disposed on the handle in the first direction, thereby pulling a second pull wire coupled to the distal portion and forming a distal curve in a second plane at the distal portion.

[0086] Example 16 is the method of example 15, wherein actuating the first actuator includes rotating a rotatable wheel.

[0087] Example 17 is the method of any of examples 15-16, wherein actuating the second actuator includes sliding a slider.

[0088] Example 18 is the method of any of examples 15-17, wherein the first plane is transverse to the second plane.

[0089] Example 19 is the method of any of examples 15-18, wherein the distal curve has a radius of curvature and the proximal curve has a radius of curvature that is greater than the radius of curvature of the distal curve.

[0090] Example 20 is the method of any of Examples 15-19, further comprising actuating the first actuator in a second direction opposite the first direction, thereby releasing tension on the first pull wire and pulling a third pull wire coupled to the intermediate portion to reform the proximal curve in the first plane in the opposite direction at the intermediate portion.

[0091] Example 21 is the method of any of Examples 15-20, further comprising actuating a third actuator disposed on the handle in a first direction, thereby pulling a fourth pull wire coupled to the distal portion to reshape the distal curve in the opposite direction in the distal portion and within the second plane.

[0092] Example 22 is the method of any of Examples 15-21, further comprising actuating a fourth actuator disposed on the handle in a first direction, thereby pulling a fifth pull wire coupled to the distal portion to reshape a distal curve in the distal portion within a first plane.

[0093] Example 23 is the method of any of Examples 15-22, further comprising actuating a fifth actuator disposed on the handle in a first direction, thereby pulling a sixth pull wire coupled to the distal portion to reshape a distal curve in the first plane in an opposite direction at the distal portion.

[0094] Example 24 is the method of any of examples 15-23, further comprising locking the second actuator in place with a lock.

[0095] Example 25 is a method according to any of Examples 15-24, further comprising slidably inserting a dilator into the lumen, the dilator having a proximal end, a distal end and a central portion disposed therebetween, the central portion being more flexible than either the proximal end or the distal end.

[0096] Example 26 is the method of any of examples 15-25, wherein actuating the first actuator includes moving a rod coupled to the first actuator, engaging the rod with a second actuator, thereby moving the second actuator in coordination with the first actuator and preventing slack in the second pull wire.

[0097] Example 27 is the method of any of Examples 15-26, further comprising actuating the first actuator in a second direction opposite the first direction, thereby releasing tension in the first pull wire and returning the proximal curve to an unbiased position.

[0098] Example 28 is the method of any of examples 15-27, further comprising actuating the second actuator in a second direction opposite the first direction, thereby releasing tension in the second pull wire and returning the distal curve to an unbiased position.

[0099] Example 29 is the method of any of examples 15-28, further comprising forming a second distal curve simultaneously with the distal curve, the second distal curve being disposed in a third plane transverse to the second plane, thereby allowing infinite passage of the elongate shaft.

[0100] In Example 30, the apparatus or method described in any one of Examples 1-29 or any combination thereof can be optionally configured such that all of the listed elements or options are available for use or selection.

[0101] The above detailed embodiments include reference to the accompanying drawings, which form a part of this detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only the elements shown or described are provided. The inventors also contemplate examples that use any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0102] In the event of a conflicting usage between this document and any document so incorporated by reference, the usage in this document shall control.

[0103] The terms "a" or "an" are used herein to include "one" or "more than one," as is common in patent documents, independent of any other instance or usage of "at least one" or "one or more." The term "or" is used herein to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. The terms "including" and "in which" are used herein as the plain English equivalents of the terms "comprising" and "wherein," respectively. Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formations, or processes that include elements in addition to those recited after such terms in a claim are still considered to be within the scope of that claim. Also, in the following claims, the terms "first," "second," and "third," etc. are used as labeling only and are not intended to impose numerical requirements on their purposes.

[0104] The above description is intended to be illustrative and not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in combination with each other. Other embodiments may also be used by those skilled in the art upon review of the above description. The Abstract is provided to enable the reader to quickly ascertain the nature of the present technical disclosure. It should be considered with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above detailed description, various features may be grouped together to simplify the disclosure. This should not be construed as intending that an unclaimed disclosed feature is essential to any claim. Rather, the subject matter of the invention may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are herein incorporated into the detailed description as an example or embodiment, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the present invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A steerable sheath, the steerable sheath comprising: an elongate 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 elongate shaft, the first tube having a lumen extending therethrough; a second tube coupled to the elongate shaft, the second tube having a lumen extending therethrough; Equipped with the elongate shaft is formed from a plurality of layers of material, the second tube being disposed on a surface of an innermost layer of the elongate shaft, an inner braided layer of the elongate shaft being disposed on the second tube, and the first tube being disposed on the inner braided layer; The steerable sheath includes: a first pullwire having a proximal end and a distal end, the first pullwire extending along the elongate shaft, the first pullwire being disposed within 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 elongate shaft, the second pull wire being disposed within the lumen of the second tube; Equipped with the lumens of the first tube and the second tube avoid entanglement of the first pull wire and the second pull wire; The steerable sheath includes: a handle coupled to the proximal portion of the elongate shaft; a first actuator disposed on the handle; a second actuator disposed on the handle; Equipped with the distal end of the first pull wire is coupled to the intermediate portion of the elongate shaft and the proximal end of the first pull wire is coupled to the first actuator; the distal end of the second pull wire is coupled to the distal portion of the elongate shaft and the proximal end of the second pull wire is coupled to the second actuator; actuation of the first actuator in a first direction pulls the first pullwire to form a proximal curve in a first arcuate direction along the intermediate portion of the elongate shaft in a first plane, and actuation of the first actuator in a second direction opposite the first direction releases tension in the first pullwire and allows the proximal curve to return to an unbiased configuration; a steerable sheath, wherein actuation of the second actuator in a first direction pulls the second pull wire to form a distal curve in a first curvature direction along the distal portion of the elongate shaft in a second plane, and actuation of the second actuator in a second direction opposite the first direction of the second actuator releases tension in the second pull wire, allowing the distal curve to return to an unbiased configuration.

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

3. 10. The sheath of claim 1, further comprising a pusher rod coupled to the first actuator, wherein actuation of the first actuator in the first direction causes the pusher rod to engage the second actuator and move the second actuator in coordination with the first actuator, thereby preventing slack in the second pull wire.

4. a third pull wire having a proximal end and a distal end, the third pull wire extending along the elongate shaft; the distal end of the third pull wire is coupled to the intermediate portion of the elongate shaft opposite the first pull wire, and the proximal end of the third pull wire is coupled to the first actuator; 2. The sheath of claim 1, wherein actuation of the first actuator in the second direction opposite the first direction pulls the third pull wire such that the proximal curve curves along the intermediate portion of the elongate shaft in an opposite direction relative to the first arcuate direction within the first plane.

5. a fourth pull wire and a third actuator, the third actuator disposed on the handle, the fourth pull wire having a proximal end and a distal end and extending along the elongate shaft; the distal end of the fourth pull wire is coupled to the distal portion of the elongate shaft opposite the second pull wire, and the proximal end of the fourth pull wire is coupled to the third actuator; actuation of the third actuator in a first direction pulls the fourth pullwire such that the distal curve curves in an opposite direction relative to the first curvature direction within the second plane along the distal portion of the elongate shaft; 2. The sheath of claim 1, wherein actuation of the third actuator in a second direction opposite the first direction of the third actuator releases tension in the fourth pull wire and allows the distal curve to return to an unbiased configuration.

6. a fifth pull wire and a fourth actuator, the fourth actuator being disposed on the handle, the fifth pull wire having a proximal end and a distal end and extending along the elongate shaft; the distal end of the fifth pull wire is coupled to the distal portion of the elongate shaft at a location circumferentially offset from the second and fourth pull wires, and the proximal end of the fifth pull wire is coupled to the fourth actuator; actuation of the fourth actuator in a first direction pulls the fifth pullwire such that the distal curve curves in a second curvature direction within the first plane along the distal portion of the elongate shaft; 6. The sheath of claim 5, wherein actuation of the fourth actuator in a second direction opposite the first direction of the fourth actuator releases tension in the fifth pull wire and allows the distal curve to return to an unbiased configuration.

7. 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 elongate shaft; the distal end of the sixth pull wire is coupled to the distal portion of the elongate shaft opposite the fifth pull wire, and the proximal end of the sixth pull wire is coupled to the fifth actuator; 7. The sheath of claim 6, wherein actuation of the fifth actuator in a first direction pulls the sixth pull wire such that the distal curve curves along the distal portion of the elongate shaft in an opposite direction relative to the second curvature direction within the first plane, and actuation of the fifth actuator in a second direction opposite the first direction of the fifth actuator releases tension in the sixth pull wire, allowing the distal curve to return to an unbiased configuration.

8. The sheath of claim 7 , wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator comprises a slider.

9. The sheath of claim 8 , wherein the second actuator, the third actuator, the fourth actuator, or the fifth actuator include a stop to prevent slidable movement thereof.

10. The sheath of claim 1 , wherein the proximal curve has a radius of curvature and the distal curve has a radius of curvature smaller than the radius of curvature of the proximal curve or the proximal curve has a radius of curvature smaller than the radius of curvature of the distal curve.

11. The sheath of claim 1 , wherein the first actuator comprises a rotatable wheel threadedly engaged with a threaded shuttle, rotation of the rotatable wheel being translated into linear motion of the shuttle.

12. 10. The sheath of claim 1, further comprising markings or indicators on the first actuator or the second actuator, the markings or indicators configured to identify actuation of the actuator element with a change in shape of the proximal or distal curve.

13. 10. The sheath of claim 1, further comprising a dilator disposed within the lumen of the elongate shaft, the dilator having a proximal end, a distal end and a central portion disposed therebetween, the central portion being more flexible than the proximal or distal ends of the dilator, thereby facilitating steering of the elongate shaft.

14. 2. The sheath of claim 1, wherein the distal curve comprises a first distal curve that curves the elongate shaft in the second plane and a second distal curve that curves the elongate shaft in a third plane transverse to the first plane, thereby forming an infinitely traversable sheath.

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