Patent Description:
<CIT> discloses a steerable catheter control mechanism for manipulating a pair of control wires which utilizes a slider mechanism coupled to the proximal ends of the control wires. However, the slider mechanism disclosed by Falwell lacks ease of use as it is awkward to grasp and use. Furthermore, the disclosed slider mechanism provides limited control in steering the catheter. The device provides a thumb control that lacks precision. It is unable to provide precise steering of the catheter as it lacks resolution for permitting minute manipulations needed to provide slight changes in the deflection of the catheter.

<CIT> discloses a bi-directional steerable catheter control handle which includes an adjustment knob rotatably connected to the handle. Rotation of the handle results in deflection of two sliding members (each connected to a pull wire) in opposite directions, resulting in respective deflection of the distal end of the catheter. However, the steerable control handle provided by Bednarek is complex and difficult to manufacture. European patent application <CIT> discloses a Bi-directional sheath deflection mechanism. A deflectable sheath for use in medical procedures in the vasculature is described. The sheath includes a handle supporting the sheath. Two pull wires run along opposite sides of the sheath to anchors at the deflectable distal end. The handle includes a rotatable member that moves a threaded member including wire guide in a back and forth translation. As the movement occurs, force is applied to either one or the other of the pull wires to cause deflection of distal end of the sheath in either and upwardly or a downwardly direction with respect to the longitudinal axis of the sheath. <CIT> discloses a steerable open lumen catheter. A steerable catheter includes a handle and a catheter tube, the distal region of which may be selectively curved by the operator. The distal end of a tip portion of the catheter tube is attached to at least one and preferably two pull cables. When a pull cable is tightened, the catheter's tip portion assumes a curve defined by the orientation in which the support members are affixed to the fluid transport tube. The two support members allow the tip portion of the catheter tube to assume a curvature only in a direction that is perpendicular to the plane of the two support members.

The invention is defined in the appended independent claim <NUM>. Specific embodiments are defined in the enclosed dependent claims.

In one broad aspect, embodiments of the present disclosure provide a control system for bi-directional control of a steerable catheter, the catheter including at least two control wires, a distal end of each of the control wires being coupled to the catheter at a distal region thereof, the control system comprising: a housing having a distal end and a proximal end coupled to the catheter; a slide assembly positioned within the housing and operable to translate linearly therein; a proximal portion of each of the at least two control wires being mounted or positioned through the slide assembly; and a control knob rotatably coupled to the housing at the distal end of the housing for linearly translating the slide assembly, thereby enabling the slide assembly to separately manipulate each of said at least two control wires to effect a change in a deflection of said catheter; wherein rotation of the control knob in a first rotational direction causes the slide assembly to tension one of said at least two control wires by causing distal movement of the slide assembly in a first linear direction to effect a change in the deflection of said catheter in a first deflection direction and wherein rotation of the knob in a second rotational direction causes the slide assembly to tension the other of said at least two control wires by causing proximal movement of the slide assembly in a second linear direction to effect a change in the deflection of said catheter in a second deflection direction.

In some embodiments of the present disclosure a slack limiting device is provided for use with a steerable catheter control system having at least one control wire, the control system comprising a mechanism for tensioning the at least one control wire for deflecting the steerable catheter and for releasing tension there-from, wherein the slack limiting device is engageable with a portion of the at least one control wire for limiting the slack therein when tension is released from the at least one control wire.

In some embodiments of the present disclosure a slide limiting mechanism is provided for use with a steerable control system for a steerable catheter having at least one control wire, the steerable control system comprising a handle having a housing with a single slide assembly disposed within the housing that has the at least one control wire coupled thereto, and a rotatable knob for moving the single slide assembly to cause a deflection of the catheter by tensioning the at least one control wire, the slide limiting mechanism comprising:
a slide limiting element positioned within the handle to limit a linear movement of the single slide assembly in a first linear direction within the handle upon rotation of the knob in a first rotational direction, to limit the tension placed on the at least one control wire, for limiting the deflection of the catheter in a first deflection direction.

In an example a method, not forming part of the present invention, is provided for using a control system to deflect a steerable catheter, the control system comprising a handle having a housing and a single slide assembly disposed within the housing that is operable via a knob, the steerable catheter comprising at least two control wires that are passed through the single slide assembly for engaging therewith, for steering the catheter in opposite deflection directions, the method comprising: moving the single slide assembly in a first linear direction to place one of the at least two control wires in tension by rotating the knob in a first rotational direction, in order to deflect the catheter in a first deflection direction; and moving the single slide assembly in a second linear direction opposite to the first linear direction to place the other of the at least two control wires in tension by rotating the knob in a second rotational direction, in order to deflect the catheter in a second deflection direction.

In an example of the disclosure a control system for providing unidirectional control of a bi-directional steerable catheter having at least two deflection directions is disclosed, the control system comprising an actuator for permitting deflection of the bi-directional steerable catheter in a first deflection direction upon actuation in a first direction, and comprising a deflection limiting mechanism for substantially limiting the deflection of the bi-directional steerable catheter in a second deflection direction by limiting actuation in a second direction.

In some embodiments of the present disclosure a slack limiting or containing device is provided for use with a control system for a steerable catheter having at least one control wire, the control system comprising a mechanism for manipulating the at least one control wire for changing a deflection of the steerable catheter, wherein the slack limiting device is engageable with a portion of the at least one control wire for limiting the slack therein during reverse manipulation of the at least one control wire.

In order that the invention may be readily understood, embodiments of the invention are illustrated by way of examples in the accompanying drawings, in which:.

With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of certain embodiments of the present invention only. Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings but rather limited to the scope of the claims.

As an overview, steerable medical devices have various uses and applications, such as for guiding and positioning devices such as catheters, guidewires and the like within a patient's body. Handles used with such steerable devices typically include a mechanism for actuating one or more pull wires capable of deflecting the steerable device and thus steering or guiding a functional tip of a medical device positioned therein.

While conceiving and reducing the instant invention to practice, the present inventors have discovered a unique design for a bi-directional control system that provides a rotatable control mechanism for operating a slide mechanism of reduced complexity for tensioning two or more control wires to change a deflection of a medical device, such as a steerable catheter apparatus. The rotatable mechanism provides enhanced control of the slide mechanism to enable precise deflections of the medical device while the slide mechanism itself comprised a relatively streamlined design compared to existing products. Some of the examples below are not a part of the present invention but represent background art that is useful for understanding the invention.

As is further described hereinbelow, the present disclosure provides a rotatable control mechanism such as a handle knob where rotation of the handle knob is converted into a tensioning force exerted separately on each of two control wires via a reduced complexity slide mechanism comprising a single movable slide assembly which is coupled, directly or indirectly, to the control wires. The tensioning force applied to each of the control wires results in a change in deflection of the medical device, such a steerable catheter, to which they are coupled. Embodiments of the present disclosure thereby avoid the need for having a plurality of sliding members, one for each of the pull wires.

In one broad aspect, embodiments of the present disclosure provide a rotatable mechanism for controlling deflection of two control wires (also referred to as pull wires) using one moving member to allow a catheter or other medical device to be steered in two different directions. The rotation of the knob in a first rotational direction moves the member along one longitudinal direction to allow one of the two pull wires to be placed in tension (to deflect the catheter to a first orientation) and rotation of the knob in an opposite rotational direction (about a longitudinal axis of the handle) moves the member along the opposite longitudinal direction to allow the other of the two pull wires to be placed in tension (to deflect the catheter to a different orientation).

In accordance with one embodiment, the present disclosure provides a control system for bi-directional control of a steerable catheter, the catheter including at least two control wires, a distal end of each of the control wires being coupled to the catheter at a distal region thereof, the control system comprising: a housing coupled to the catheter; a slide assembly positioned within the housing and operable to translate linearly therein; a proximal portion of each of the at least two control wires being positioned through the slide assembly; and a control knob rotatably coupled to the housing for linearly translating the slide assembly, thereby enabling the slide assembly to separately manipulate each of said at least two control wires to effect a change in a deflection of said catheter; wherein rotation of the control knob in a first rotational direction causes distal movement of the slide assembly in a first linear direction causing the slide assembly to tension one of said at least two control wires thereby effecting a change in the deflection of said catheter in a first deflection direction and wherein rotation of the knob in a second rotational direction causes proximal movement of the slide assembly in a second linear direction causing the slide assembly to tension the other of said at least two control wires thereby effecting a change in the deflection of said catheter in a second deflection direction.

In one example not being a part of the present invention, a steerable control system or handle <NUM> is provided for manipulating a medical device. The medical device may include, without limitation, a catheter, sheath, introducer or similar medical devices. In a specific example, as shown in <FIG> and <FIG>, the handle <NUM> is coupled to a sheath <NUM> to enable a user to manipulate or steer the sheath <NUM> in a desired direction during use. The handle <NUM> comprises a knob <NUM> that is rotatably coupled to a handle housing <NUM>. The knob <NUM> is rotatable about the longitudinal axis of the handle <NUM> and rotates with respect to housing <NUM>. In operation, the rotation of the knob <NUM> in a first rotational direction allows the user to steer or deflect the sheath <NUM> in a first direction, whereas the rotation of the knob <NUM> in a second rotational direction allows the user to steer or deflect the sheath <NUM> in a second direction. In some embodiments as described herein, the bi-directional steerable catheter described is operable to be deflected in two different deflection directions, a first and a second deflection direction. In other embodiments, the bi-directional steerable catheter is configured to (or has the internal workings that enable it to) deflect in two different deflection directions; however, the deflection of the catheter in one of its deflection directions is limited or restricted such that the observed deflection of the catheter is limited to a single deflection direction (relative to the starting, or neutral, position). Thus, in some embodiments a unidirectional control system is provided for a bi-directional steerable catheter to provide a unidirectional steerable catheter including at least two control wires,.

The rotation of the knob <NUM> is converted into a deflection of the sheath <NUM> via a slide assembly <NUM>, shown in <FIG>. Generally, knob <NUM> is co-operatively engaged with the slide assembly <NUM> which is housed within a lumen defined by the handle housing <NUM>. In a specific example, the knob <NUM> is threadably engaged with slide assembly <NUM>. The rotation of knob <NUM> causes a corresponding linear translation of the slide assembly <NUM> within the housing <NUM>. This translation of the slide assembly <NUM> is converted into a tensioning of the control wires coupled to the slide assembly <NUM> and thereby resulting in a deflection of the sheath <NUM>.

More specifically, slide assembly <NUM> is coupled to respective proximal ends of a pair of control wires that extend substantially along the length of the sheath <NUM>, for example control wires <NUM> and <NUM> as shown in <FIG>. A distal end (not shown) of each of the control wires <NUM>, <NUM> is coupled to a distal portion of the sheath <NUM>. The rotation of the knob <NUM> in one direction causes the slide assembly <NUM> to translate proximally within the housing <NUM> pulling one of the control wires (such as control wire <NUM>) to deflect the sheath <NUM> in a first direction, whereas the rotation of the knob <NUM> in an opposing direction causes the slide assembly <NUM> to translate distally within the housing <NUM> pulling the other of the control wires (such as control wire <NUM>) to deflect the sheath <NUM> in a second direction.

In one example as shown in <FIG>, in order to allow the slide assembly <NUM> to separately impart a pulling force on each of the two control wires, one of the two control wires (such as control wire <NUM>) is directly coupled to the slide assembly <NUM> whereas the other of the control wires (such as control wire <NUM>) is indirectly coupled to the slide assembly <NUM> via a direction reversing element <NUM>' such a pulley or a pin. In other words, a means for of coupling the distal ends of the wires to opposite sides of the slide is included in the handle, whereby motion of the slide in one direction will apply tension to one wire while motion of the slide in the other direction will apply tension to the other wire. As used herein, "directly coupled" is taken to mean that the proximal end of the wire is operably coupled (but not necessarily physically attached or integral with) to the slide without passing through an intermediate structure, while "indirectly coupled" is taken to mean that the proximal end of the wire is operably coupled (but not necessarily physically attached or integral with) to the slide after passing through an intermediate structure or element, such as a direction reversing element.

In a specific example, a proximal end of control wire <NUM> exits sheath <NUM> and is routed proximally through the slide assembly <NUM> to be coupled at or to a proximal face of the slide assembly <NUM>, i.e. proximally of the slide assembly. Thus, in this example, control wire <NUM> is "directly coupled" to slide assembly <NUM>. Similarly, a proximal end of control wire <NUM> exits sheath <NUM> and is routed proximally through the slide assembly <NUM> where it exits the slide assembly <NUM>. The control wire <NUM> is then passed around or through the direction reversing element and routed back distally so that it can be passed distally through the slide to be coupled at or to a distal face of the slide assembly <NUM>, i.e. distally of the slide assembly. Thus, in this example, control wire <NUM> is "indirectly coupled" to the slide assembly <NUM>. As used herein, the distal face of the slide assembly <NUM> may refer to a distal face of any portion of the slide assembly <NUM>. Similarly, the proximal face of the slide assembly <NUM> may refer to a proximal face of any portion of the slide assembly <NUM>. As an example, the control wires exit the sheath <NUM> along a portion of the handle <NUM> defined by the knob <NUM> to minimize any excessive angles and/or stress placed on the wire as it is coupled to the slide assembly <NUM>.

As shown in <FIG>, the housing <NUM> comprises an internal housing portion 20a (also referred to as internal housing 20a for conciseness) defining a lumen that is encased by an external or outer housing portion 20b (also referred to as external or outer housing 20b for conciseness). Similarly knob <NUM> that is coupled to the housing <NUM>, also comprise an inner knob portion 10a (also referred to as inner knob 10a for conciseness) defining a lumen there-through an external or outer knob portion 10b (also referred to as external or outer knob 10b for conciseness) that encases the inner knob 10a. A means is provided to secure the inner knob 10a to the inner housing 20a. In one embodiment a portion of the inner knob is received within the inner housing to allow one or more pins <NUM> to be inserted transversally through the inner knob 10a and the inner housing 20a to secure them in place. The pins <NUM> may comprise a metal such as stainless steel. In a specific example, apertures or holes <NUM> may be provided in the inner housing 20a and a circumferential groove <NUM> (as shown in <FIG>), may be provided in a proximal portion of inner knob 10a, each for receiving the pins <NUM>. The pins <NUM> lock the inner knob 10a and inner housing 20a together to prevent longitudinal displacement while permitting rotational movement with respect to each other. In other words, the inner knob 10a is free to rotate with respect to inner housing 20a, while maintaining translational coupling/locking of inner knob 10a with the inner housing 20a. In a specific example, the handle <NUM> comprises two pins <NUM> that couple the inner knob 10a to the inner housing 20a. In one example, the knob <NUM> is positioned at the distal end of the handle defining the distal direction (D) and the opposing end of housing <NUM> forms the proximal end of the handle defining the proximal direction (P), as marked in the drawings. In an alternate example a single aperture or hole <NUM> may be provided for receiving a pin <NUM>.

In one embodiment, as shown in <FIG>, the inner housing 20a defines a lumen <NUM> there-through for housing the slide assembly <NUM> and to allow translation of the slide assembly <NUM> therein. The inner housing 20a further comprises a window <NUM> which may guide the slide assembly <NUM> during translation and may also provide access to aid in coupling the control wires <NUM>, <NUM>, to the slide assembly <NUM>. In some embodiments the inner housing 20a additionally comprises a groove or track 21a to guide and limit the translation of the slide assembly <NUM> (shown in <FIG>). In one embodiment, both the inner housing 20a and the outer housing 20b may comprise a polymer. As a particular example, the inner housing 20a comprises Acrylonitrile butadiene styrene (ABS) and the outer housing 20b comprises polypropylene. In other embodiments, the housing <NUM> may comprise a metal.

In one example, the outer knob 10b comprises inwardly extending projections that co-operatively engage with/fit into grooves within the inner knob 10a. This allows the inner knob 10a to be rotated along with the outer knob 10b. Thus rotational motion of the outer knob 10b is imparted to the inner knob 10a and they can be operated as a single unit. In one embodiment as shown in <FIG> and <FIG> the inner knob 10a may be tapered towards the distal end. The inner knob 10a and the outer knob 10b may also comprise a polymer. As a particular example, the inner knob 10a comprises DUPONT™ DELRIN® 100P and the outer knob 10b comprises polypropylene.

In some embodiments, the outer knob 10b may have an exterior comfort grip <NUM> disposed thereon, as shown in <FIG>. An example of a grip <NUM> is additionally shown in a cross-sectional view illustrated in <FIG>. The comfort grip <NUM> may comprise an elastomer layer that is over-molded onto a portion of the outer knob 10b. In a particular example, the exterior comfort grip <NUM> comprises Santoprene® SSA <NUM> that is over-molded onto a portion of the outer knob 10b that comprises polypropylene.

In a specific example as shown in <FIG>, the slide assembly <NUM> comprises a bolt <NUM> and an intermediate housing <NUM> comprising a carriage <NUM>. The carriage <NUM> comprises a carriage proximal face 34a and a carriage distal face 34b. Each of the control wires <NUM>, <NUM> that exit from sheath <NUM> pass through the carriage <NUM> with control wire <NUM> being operably coupled at or to the proximal face 34a of the carriage <NUM> using a crimp <NUM>. Crimp <NUM> substantially abuts against the proximal face 34a and ensures that as the slide assembly <NUM> translates proximally it pulls the wire <NUM> along with it. Similarly, the control wire <NUM> is operably coupled to carriage <NUM> using a crimp <NUM>. Crimp <NUM> substantially abuts against the distal face 34b of the carriage <NUM> and ensures that as the carriage <NUM> translates distally it pulls control wire <NUM> along with it. As shown in <FIG> control wire <NUM> is initially routed proximally through the carriage <NUM> and is then looped around so that it passes distally through the carriage <NUM> to be coupled to the distal face 34b. In some embodiments the control wires <NUM>, <NUM> may be pre-crimped. In other embodiments the control wires <NUM>, <NUM> may be crimped post-assembly after being routed through the slide assembly <NUM>.

In one embodiment of slide assembly <NUM>, carriage <NUM> of the intermediate housing <NUM> may comprise multiple components that cooperatively engage or can be assembled to form the carriage <NUM>. As an example of this, as shown in <FIG> and cross-sectional view 3D, the carriage <NUM> may have base portion <NUM>' having grooves 35x, 35y and 35z through which wires <NUM> and <NUM> may be positioned, and a cover portion or a wire retainer <NUM>" that engages with the base portion <NUM>' after the wires have been placed to form openings or passages 35x', 35y' and 35z' through which control wires <NUM>, <NUM> can slide. The cover portion <NUM>" may be detachably secured to the base portion <NUM>' for example using a snap fit arrangement. The cover portion <NUM>" may comprise downwardly extending projections or legs <NUM>, as shown in <FIG>, which are received within a groove <NUM> within the carriage base portion <NUM>'. Legs <NUM> may have tabs, such as snap-fit tabs, that may interlock with a surface of groove <NUM> to secure cover portion <NUM>" to base portion <NUM>'.

Additionally, as shown in <FIG>, the base portion may comprise a groove 35w through which the control wires <NUM> and <NUM> may be routed after exiting the sheath <NUM> to assist in placement of the wires through each of the grooves 35x, 35y and 35z. The cover portion <NUM>" may additionally comprise one or more teeth or ribs 35a that interact with the grooves 35x, 35y and 35z to partially form the passages or openings 35x', 35y' and 35z' to retain the wires therein. In one example, the cover portion <NUM>" comprises two ribs or teeth 35a. In other embodiments the grooves may be positioned within the cover portion <NUM>", or still in other embodiments grooves may be positioned within both the base portion <NUM>' and the cover portion <NUM>" as shown in <FIG>. In other words, either the base portion <NUM>' and/or the cover portion <NUM>" may receive wires <NUM>, <NUM> and abut to form openings 35x', 35y' and 35z' within which wires can travel longitudinally. In one example, as shown, control wire <NUM> may be routed through openings or passages 35x' and 35z' that are located towards the exterior or opposing lateral edges of the slide assembly <NUM> to prevent excessive stress or strain on the control wire <NUM> and may help prevent the slide assembly <NUM> from rotating within the inner housing 20a (Whereas wire <NUM> is routed through opening or passage 35y'). More specifically, the control wire <NUM> is routed proximally through the slide assembly <NUM> through passage 35x', wrapped around the pulley and routed distally through the slide assembly <NUM> through passage 35z to be coupled to the distal face of the carriage <NUM>. In other embodiments, wires <NUM> and <NUM> may be routed through any of the openings or passages within the slide.

In some embodiments for example in the embodiments illustrated in <FIG>, the slide assembly <NUM> comprises a channel <NUM> [shown in <FIG>] that extends through the bolt <NUM> as well as through the carriage <NUM> to allow a portion of the sheath <NUM> to be routed there-through. In a specific example, the sheath <NUM> extends through substantially the entire length of the handle <NUM> including the knob <NUM> as well as the housing <NUM>.

Alternatively, as shown in <FIG>, the base portion <NUM>' and cover portion <NUM>" may be formed integrally with one another. In other words, the carriage <NUM> may be of unitary construction and is formed of a single component. Similar to the embodiment described previously, the carriage <NUM> may comprise three channels or openings 35x' 35y', and 35z' through which wires <NUM> and <NUM> can be threaded respectively as shown in the cross-sectional view of <FIG>. In one example, control wire <NUM> is routed through openings 35x' and 35y' and control wire <NUM> is routed through opening 35z', in a manner similar to the one described herein above.

As discussed above, slide assembly <NUM> of handle <NUM> (as shown in <FIG>) comprises a bolt <NUM> having an externally threaded arrangement which is received within the knob <NUM> having a corresponding internally threaded arrangement. As shown in <FIG>, this allows the knob <NUM> to translate the carriage <NUM> of the slide assembly <NUM> as it is rotated. In one example, the external thread of the bolt <NUM> may be in the form of a helical thread 33a that co-operatively engages with an internal helical thread <NUM> the inner knob 10a. In some examples, the helical thread 33a may be a continuous external thread as shown in <FIG> and <FIG>. This may provide more surface contact between the thread 33a of bolt <NUM> and internal thread <NUM> of inner knob 10a. This may enhance the friction between the bolt <NUM> and the inner handle and may allow for enhanced control. After the knob <NUM> has been rotated the enhanced friction may aid in maintaining the position of the knob <NUM> with respect to the housing to retain the sheath <NUM> at its desired deflection. Alternatively, the bolt <NUM> may have a discontinuous thread along its length. In some embodiments, the slide assembly <NUM>, including bolt <NUM> is formed from a polymer. More particularly, in one example the slide assembly <NUM> comprises Dupont™ Delrin® 100P. Alternatively, the slide assembly <NUM> may comprise a thermoplastic. In still other embodiments, the slide assembly may comprise a metal. In some embodiments bolt <NUM> of the slide assembly <NUM> may have a rough exterior surface to maintain frictional engagement with the inner knob 10a. In some embodiments, bolt <NUM> with external threads 33a is coated with a lubricant such as a fluorocarbon gel <NUM>. In one embodiment, the exterior thread of the bolt <NUM> may have tapered edges that form an overhang or the thread may have bevelled which may facilitate manufacturing of the slide assembly <NUM> for example through molding.

As mentioned above, wire <NUM> is passed through a direction reversing element prior to being coupled to the slide assembly <NUM>. In a specific example, as shown in <FIG>, the wire <NUM> as it exits the sheath <NUM> is passed in a proximal direction through the carriage <NUM> and then around a direction reversing element <NUM>' so that it can be passed distally through the carriage <NUM> to be coupled to the distal face 34b of the carriage <NUM>. In one specific embodiment, the direction reversing element comprises a pin. In another specific embodiment, as shown, the direction reversing element comprises a pulley assembly <NUM> comprising a pulley <NUM>, also shown in the cross-sectional view of <FIG>. The pulley assembly <NUM> maybe coupled to the inner housing 20a using a snap fit. More specifically, with reference to <FIG>, the wire <NUM> as it exits proximally from carriage <NUM>, it is routed over the pulley assembly <NUM> around the pulley <NUM> and passed distally through carriage <NUM> to be coupled to its distal face 34b. This is also illustrated in <FIG>.

In one specific embodiment, as shown in <FIG> and <FIG>, the pulley assembly <NUM> comprises height guide <NUM> that helps maintain or secure the control wire <NUM> around the pulley <NUM>. The height guide <NUM> may prevent the control wire from slipping or slide off the pulley <NUM> by maintaining its position along the plane of the pulley <NUM>. In one example, the pulley <NUM> may comprise a groove or slot along its circumference to allow the control wire <NUM> to remain in place. The groove or slot <NUM>' functions to guide and maintain the control wire <NUM> around the pulley <NUM>. Additionally a pulley guide <NUM> may be provided that is substantially adjacent to and circumferentially surrounds at least a portion of the pulley <NUM>. The control wire <NUM> is guided around the pulley so that it is positioned between the pulley <NUM> and the pulley guide <NUM>. The pulley guide <NUM> functions to guide and trap the control wire <NUM> around the pulley <NUM> in order to maintain its position. Thus, the height guide <NUM> and the pulley guide <NUM> help to retain the control wire <NUM> about the pulley. As illustrated in <FIG>, the pulley guide <NUM> may additionally comprise teeth or projections 56a that additionally restrict the movement of the control wire <NUM> to further reduce the chances of misalignment of the control wire <NUM> and prevent the control wire <NUM> from falling off the pulley <NUM>. The teeth or projections 56a extend from the pulley guide <NUM> inwardly towards the pulley <NUM> to control movement of the control wire <NUM>, as shown in <FIG>. By providing one or more projections 56a between the pulley guide <NUM> and the pulley <NUM>, the amount of friction between the control wire <NUM> and the pulley guide <NUM> is increased. In some examples, this may allow the pulley <NUM> to function as a pin. In some embodiments, each of the pulley <NUM>, height guide <NUM> and the pulley guide <NUM> may be separate components or may be formed integrally with the pulley assembly <NUM>, as shown. In one specific example as shown in <FIG>, and in the cross-sectional view shown in <FIG>, the pulley <NUM> is mounted on a pin <NUM> of the pulley assembly <NUM>. A washer 55a and bolt 55b may be used to affix the pulley <NUM> to the pulley assembly <NUM>. The pulley assembly <NUM> may co-operatively engage with the inner housing 20a. In one example, the washer 55a may comprise stainless steel and bolt 55b may be a self-threading screw that comprises steel.

In one embodiment, the pulley assembly <NUM> is detachably coupled to the inner housing 20a of the handle <NUM>. In one example, the pulley assembly <NUM> is coupled to the inner housing 20a using a friction fit. More specifically, the pulley assembly <NUM> is coupled to the housing <NUM> using a snap fit arrangement. In one example, the pulley assembly <NUM> may comprise four legs <NUM>(two on each side of the pulley assembly <NUM>), with each of the four legs <NUM> having laterally extending projections 57a that engage with corresponding openings <NUM> within the inner housing 20a, as shown in <FIG>. In one example, the pulley assembly <NUM> may be coupled to the inner housing 20a, after the sheath <NUM> is inserted along the inner housing 20a. The sheath <NUM> may be coupled to a hub <NUM> which may also be partially positioned within the inner housing 20a. In one example the hub <NUM> comprises a snap fit <NUM> for engaging with a hub cap 85b. In one example, the hub <NUM> comprises ribs <NUM> and one or more keys that co-operatively engage or lock with corresponding grooves <NUM> within inner housing 20a. This provides a rotational locking mechanism that prevents rotational displacement of the sheath <NUM> with respect to the handle <NUM>. Once the sheath <NUM> with hub <NUM> have been positioned within the inner housing 20a, the projections of the pulley assembly <NUM> may then co-operatively engage with openings <NUM> within the inner housing 20a. This may allow the hub <NUM> to be locked longitudinally so that the longitudinal movement of the sheath <NUM> with respect to the inner housing 20a is limited. Thus in some embodiments, the control handle <NUM> provides both a rotational locking mechanism as well as a longitudinal locking mechanism for the sheath <NUM>. In some embodiments, the hub <NUM> includes a port <NUM> that extends from the hub <NUM> and is encased within the outer housing 20b. In some embodiments, the pulley assembly <NUM> including the pulley <NUM> may comprise a biocompatible material such as a polymer. In one example, the polymer is Dupont™ Delrin®. In a specific example, the pulley assembly <NUM> comprises Dupont™ Delrin® 100P.

In an alternate example, the direction reversing element may comprise a pin or other structure for routing or redirecting an elongate element such as a pull wire. In such an example, the wire <NUM>, as it exits proximally from carriage <NUM>, may be routed over and/or around the pin and passed distally through carriage <NUM> to be coupled to its distal face 34b of the carriage <NUM>. In a specific example, the pin extends perpendicularly to the plane in which control wire <NUM> travels. In some embodiments, the pin is positioned proximally relative to the slide assembly <NUM>. For example, the pin may be coupled to a proximal portion of the handle assembly <NUM>. Alternatively, the pin may be positioned on the slide assembly <NUM> or be coupled to the slide assembly <NUM>. In embodiments where a pin is used, the control wire <NUM> that is routed proximally from the carriage <NUM> may be looped around the pin so it can be routed distally to be coupled to the distal face 34b of the carriage <NUM>.

In an embodiment of the present disclosure, one or more slack limiting or containing elements <NUM> may be provided within the handle <NUM> that may be coupled to one or both of the control wires <NUM>, <NUM>. In a specific example, a slack limiting element <NUM> is provided that allows frictional engagement of control wire <NUM> to limit or contain slack to a portion of the control wire <NUM>. In one example, the slack limiting or containing element <NUM> is coupled to the pulley assembly <NUM>, as shown in <FIG>.

In one specific embodiment, the slack limiting or containing element <NUM> may comprise a serpentine friction device 60A as shown by <FIG> and <FIG>. The serpentine friction device 60A comprises pins <NUM> (as shown in <FIG>) that extend perpendicularly to the path of the control wire <NUM> as shown in <FIG> and <FIG>. As further shown in <FIG>, the control wire <NUM> is directed or weaved through spaces, gaps or openings <NUM> defined by the pins <NUM> and held in place by the pins <NUM>. The serpentine friction device 60A may comprise pins <NUM> that are off-centred from each other (for example laterally offset) and may partially overlap each other with respect to the longitudinal axis of the control wire <NUM>. In a specific example the serpentine friction device 60A comprises three pins <NUM>. The two outer pins <NUM>(a) and <NUM>(c) may be positioned such that they are off-axis from a central pin <NUM>(b), as illustrated in <FIG>. As further illustrated in <FIG>, in a specific example, the serpentine friction device comprises pins that are attached to each other along a top portion <NUM>. In other embodiments, the serpentine friction device 60A may comprise ribs or raised surfaces with which the wire frictionally engages. Control wire <NUM> may be weaved through the ribs such that it frictionally engages the ribs.

In another example, as shown in <FIG>, the serpentine friction device 60A may comprise two portions a base portion <NUM> and a top portion <NUM> with the pins <NUM> extending between the base portion <NUM> and the top portion <NUM>. The control wire <NUM> may be threaded through openings <NUM> between each of the pins <NUM> and the top portion <NUM> may be used to secure control wire <NUM> in place. Alternatively, each of the pins <NUM> are formed integrally with the base portion <NUM> and top portion <NUM>, respectively and control wire <NUM> may be threaded through openings <NUM> prior to being coupled to the slide assembly <NUM>. Still furthermore, the pins <NUM> may only be attached to a base portion <NUM>.

In an alternate embodiment of the present disclosure, the slack limiting or containing element <NUM> comprises a friction device that is biased 60B as shown in <FIG>. The biased friction device 60B may be coupled to the pulley assembly <NUM> that is operable to co-operatively engage with the inner housing 20a. In one example, the biased friction device 60B may be coupled to the pulley assembly <NUM> via a snap fit arrangement. The friction device 60B comprises a friction block <NUM> and clip <NUM> coupled to the friction block <NUM>. The friction block <NUM> may define an opening 63a to receive the clip <NUM>. The clip <NUM> may be biased towards the friction block <NUM>. As mentioned previously, one or both of the control wires <NUM>, <NUM> may be coupled to a biased friction device 60B. In one example, control wire <NUM> passes through the biased friction device 60B such that it is held between the clip <NUM> and the friction block <NUM>. In one example, clip <NUM> comprises a spring biased mechanism. In some embodiments, the friction block <NUM> may comprise a polymer. In other embodiments the friction block <NUM> may comprise an elastomer and the clip <NUM> may comprise metal. In one example, the friction block <NUM> comprises rubber and the clip comprises a wire band and friction may be created between the wire band and the rubber. In some embodiments the bias mechanism of the clip <NUM>, for e.g. spring may be adjustable or tunable.

In still another embodiment the friction device may comprise a resilient friction device 60C for frictionally engaging the control wire <NUM>. In one example the resilient friction device 60C may comprise an elastomer block 67a as shown in <FIG>. In one embodiment the elastomer block 67a may comprise a rubber block. The elastomer block 67a may define a slit 67b extending longitudinally along its length thereof. A control wire, for example, control wire <NUM> may be guided within the opening of slit 67b. The slit 67b may define two downwardly extending legs <NUM> of the elastomer block 67a. The control wire <NUM> may be frictionally engaged by the downwardly extending legs <NUM> and held between the legs <NUM>.

In some embodiments, the inner housing 20a is configured to guide the slide assembly <NUM> along a linear path within the inner housing 20a. In one example as shown earlier in <FIG> and <FIG>, the inner housing 20a comprises a groove or track 21a that runs substantially along the length of the inner housing 20a. The slide assembly <NUM> may comprise a raised projection 31a (see, for example, <FIG>) along the base of the slide assembly <NUM> that co-operatively engages within the track 21a to aid in maintaining linear translation of the slide assembly <NUM> along the track 21a.

The track 21a may additionally function as a slide stop to restrict the movement of the slide assembly <NUM> to allow for a desired deflection of the sheath <NUM>. In other words the length of the track 21a restricts the distance the slide assembly <NUM> may travel in a given direction (either in the proximal and/or distal direction) which may be used to restrict the amount of deflection of the sheath <NUM>. The groove or track 21a defines an end wall 21a' on each of its two opposed ends as shown in <FIG> and <FIG>. Once the raised projection 31a of the slide assembly <NUM> reaches the end of the track it abuts against the wall 21a' at the end of the groove or track 21a stopping the slide assembly <NUM> (As shown in <FIG>, the groove or track 21a functions as a slide stop in the absence of a tubular slide stop 21b discussed further herein below). <FIG> illustrate grooves 21a of different lengths and as such the distance travelled by the slide assembly <NUM> is different for each of the embodiments shown in <FIG>.

In a further alternative, an adjustable length stopper may be provided that is coupled to the track 21a (it may engage with the track 21a using a snap fit arrangement or may be coupled thereto using any other means such as friction fit or glue). The adjustable length stopper may comprise an arm extends out and can engage with the slide assembly <NUM> thus preventing translation of the slide assembly <NUM>. In another example as shown in <FIG>, the adjustable length stop may comprise a pin 21z that may be inserted at the end of the groove or track 21a [for example inside the groove of <FIG>] next to wall 21a' to shorten the length of the track. In other words the pin 21z is provided for interacting with the track 21a to change the length of the track 21a. In some embodiments the pin 21z may be inserted within the track 21a proximal to the slide assembly <NUM>. In other embodiments, the pin 21z may be inserted within the track 21a distal to the slide assembly <NUM>. Still further, the adjustable length stopper may in the form of a block or an arm that may be affixed within the track and effectively functions to shorten the length of the track 21a.

In some embodiments, the slide restricting element comprises a tubular slide stop 21b as shown in <FIG>, <FIG>, <FIG>, <FIG> and <FIG>. As an example, the tubular slide stop 21b is mounted over the sheath <NUM> on a proximal side of the slide assembly <NUM>. In some embodiments, the tubular slide stop 21b may comprise a piece of hard or rigid tubing that abuts against a hub of the sheath and may comprise notches to allow engagement therewith and with the inner housing 20a. In one example, a glue joint may be provided between the tubular slide stop 21b and the hub on which it is mounted. In some embodiments, the surface contact between the tubular slide stop 21b and hub <NUM> may be enhanced for adhering the tubular slide stop 21b to the hub. In some embodiments, the tubular slide stop 21b may have additional notches for interacting with pulley assembly <NUM> and inner housing 20a. In some embodiments, as shown in <FIG> and <FIG>, the tubular slide stop 21b may abut against and/or interact with the pulley assembly <NUM>. In other embodiments, the tubular slide stop 21b may be mounted over the sheath and may not be affixed. The tubular slide stop 21b may comprise a relatively flexible or soft/resilient material such as low-density polyethylene (LDPE). In some embodiments the tubular slide stop 21b may comprise a relatively harder or more rigid material. In a specific example, the tubular slide stop 21b comprises a high-density polyethylene (HDPE). Alternatively, the tubular slide stop may comprise stainless steel. In one example, the tubular slide stop 21b comprises a cylinder. Alternatively, the tubular slide stop 21b is formed from a segment of a cylinder. In some embodiments, the inner diameter of the tubular slide stop 21b may be larger than the outer diameter of the sheath <NUM> over which it is mounted. The tubular slide stop defines a distal wall 21b' that interacts with slide assembly <NUM> to stop it.

In still other embodiments as shown in <FIG>, the tubular slide stop 21b may be in the form of a collar 21y (defining a proximal wall 21y') that fits over the bolt <NUM> of the slide assembly <NUM> on a distal side of the slide assembly <NUM>. Alternatively, the range of motion the slide assembly <NUM> may be altered by shortening or increasing the length of the bolt <NUM> of the slide assembly <NUM>. In a further alternative, the tubular slide stop 21b may be formed as a part of the pulley assembly <NUM> and may extend there-from into the inner housing 20a.

In alternative embodiments as shown in <FIG>, the slide stop or slide limiting or restricting feature may comprise a bar 21c extending laterally across the inner housing 20a. In other words, the bar 21c extends across the width of the inner housing 20a. The bar 21c may be positioned between the slide assembly <NUM> and the pulley assembly <NUM> with the bar defining a defining a distal wall 21c'.

In some examples not being a part of the invention, as shown in <FIG>, the slide stop may comprise a rivet 21d. Alternatively, the slide stop may be in the form of a pin or a screw. The rivet 21d is positioned through an opening within and the groove or track 21a within the inner housing 20a and extends into the lumen of the inner housing 20a in the form a projection that extends vertically up. The rivet 21d may be secured to the inner housing through a friction fit. The rivet 21d is positioned in the path of the slide assembly <NUM> and functions to restrict its movement. Alternatively, rivet 21d may be coupled to a secondary component such as a block that is positioned within the inner housing 20a and functions to block the slide assembly <NUM>.

Alternatively, an actuator may be provided on the handle that allows adjustment of the slide limiting feature by the user prior to or during use so that the maximum radius of curvature of the sheath <NUM> in either one or both directions may be adjusted. In some embodiments the actuator may be in the form of a knob or a button.

In a still further alternative, the slide restricting component or slide stop may comprise an extension 21e of the pulley assembly <NUM>, as shown in <FIG> that extends distally into the lumen of the inner housing 20a.

In some embodiments, control wires <NUM>, <NUM> comprise a metal. More specifically, in one example the wires <NUM>, <NUM> comprise stainless steel. In some embodiments, the wires <NUM>, <NUM> comprise a drawn <NUM>-series stainless steel wire. In some embodiments, at least one of the control wires <NUM>, <NUM> comprise a round wire. In other embodiments, at least one of the control wires <NUM>, <NUM> comprise a flat wire which may be a rectangular wire. In one specific embodiment, the wires <NUM>, <NUM> comprise stainless steel 304V. In one example, wires <NUM>, <NUM> have a cross-section of about <NUM>" × <NUM>" (<NUM> - <NUM>). In another example, wires <NUM>, <NUM> have a cross-section of about <NUM>" × <NUM>" (<NUM> - <NUM>).

As shown in <FIG>, in some examples not being part of the invention the crimps <NUM>, <NUM> may comprise an adjustable crimp. In one example, the adjustable crimp may comprise a nut and bolt assembly. In one embodiment, the adjustable crimp may comprise a bolt or screw <NUM> with external threads that co-operatively engage with internal threads within the nut <NUM>. A cylindrical crimper part <NUM>', <NUM>' is held partially within the screw <NUM>. The initial length of the wires <NUM> and <NUM> may be adjusted by adjusting the position of the screw <NUM> relative to the nut <NUM>. In some embodiments one or more of the openings 35x' 35y' and 35z' within the carriage <NUM> may have a diameter sufficient to accommodate the bolt or screw <NUM>. In other embodiments, crimps <NUM>, <NUM> may not be adjustable crimps.

In some examples not being part of the invention, sheath <NUM> may extend through the handle <NUM> from the proximal to the distal end of handle <NUM> as shown in <FIG>. This is additionally illustrated in the cross-sectional view of <FIG>. In one embodiment, the sheath <NUM> is coupled to a hub <NUM> at its proximal end as additionally shown in <FIG> and <FIG>. The hub has a side-port <NUM> defining an opening there-through. In one example, the side-port <NUM> may be angled. In one embodiment, the side-port <NUM> may be at an angle of about <NUM>° with respect to the longitudinal axis of the hub <NUM>. In other embodiments, any other suitable angle may be used. As shown in <FIG>, the side-port is connected to a stopcock <NUM> for example a <NUM>-way stopcock via tubing <NUM> which in one example may comprise polyurethane tubing. The angled side-port <NUM> may enhance usability of the handle <NUM> by ensuring that the side-port <NUM> and the stopcock <NUM> coupled thereto remain out of the way of the user, during use of the handle <NUM>. In some examples, the side-port <NUM> may be used as a point of reference in order to orient the sheath <NUM> distal tip. In one example, the opening defined by the side port may allow physicians to inject fluid for e.g. saline or contrast through the sheath during the procedure. In one example, delivery of contrast from the side-port may allow for imaging during use, where the steerable handle assembly <NUM> is used to access a region of tissue within the patient's body.

In some embodiments the hub <NUM> may be encased within the outer housing 20b as shown in <FIG>, <FIG>, <FIG> and cross-sectional views 4B-4C. An end cap 20c may be used to secure hub <NUM> within the inner housing 20a. In one embodiment, the end cap 20c may comprise a polymer. In a specific example, the end cap 20c comprises polypropylene. The sheath hub <NUM> may be operable to receive a dilator for insertion into the sheath.

In one embodiment, a locking mechanism may be provided to lock the position of the handle knob <NUM> with respect to the housing <NUM>, in order to maintain a specified angle of deflection of the sheath tip. In one embodiment a slider lock may be provided. In other embodiments friction fit or frictional engagement between the threads <NUM> of the inner knob 10a and the threads of the bolt <NUM> of the slide assembly <NUM> (as shown in <FIG>) may provide sufficient frictional force in order to maintain the position of the knob <NUM> to aid in maintaining the desired deflection of the sheath <NUM>. In one example, the slide assembly <NUM> including the bolt <NUM> and carriage <NUM> may have a surface finish that provides sufficient friction to maintain the desired deflection and hence the position of the sheath distal end. In one example, the slide assembly <NUM> and/or the lumen of the internally threaded knob <NUM> may have a rough surface finish to enhance the friction between the two. In one example, both the inner knob 10a and the slide assembly <NUM> comprise Dupont™ Delrin® 100P as noted hereinabove.

Additionally, in some embodiments as shown in <FIG>, a chamfer or groove <NUM> may be provided within the inner knob 10a, at the interface between the inner knob 10a and the inner housing 20a to allow a resistance or frictional element such as an o-ring <NUM>' to be placed therein. This may enhance friction between the inner knob 10a and the inner housing 20a to maintain the position of the inner knob 10a with respect to the inner housing 20a after it has been rotated. In other words, the o-ring <NUM>' allows for retention of the curve of the sheath <NUM> after it has been steered or deflected. In one embodiment, the o-ring may comprise a polymer. In other embodiments the o-ring may comprise a Nitrile. In a specific embodiment, the o-ring may comprise BUNA-N. In another example, the o-ring comprises a fluoroelastomer such as Viton®. In some such embodiments, a lubricant or dampening grease may be applied to the o-ring to dampen noise or in other words to prevent squeaking as the inner knob 10a is rotated with respect to the inner housing 20a. In a particular example the lubricant comprises a synthetic hydrocarbon grease such as Nyogel 767A. Alternatively, a washer, for example a Teflon washer may be inserted over the inner knob 10a at the interface between the outer knob 10b and the inner housing 20a to reduce friction. In some additional embodiments, one or more o-rings <NUM>' may be provided as shown in <FIG> that are received within one or more grooves <NUM> within the inner housing that provide an interface or a seal between the inner housing 20a and the outer housing 20b. In some embodiments, one of the grooves <NUM> may be formed partially within the inner housing 20a and partially within a component within the inner housing 20a, such as within a segment of the pulley assembly <NUM>.

In use, the sheath <NUM> may be inserted within the vasculature of a patient's body and advanced to a target location. The handle <NUM> may then be manipulated to allow the user to deflect a distal portion of the sheath <NUM> in the desired direction. In one broad embodiment, a rotational mechanism is provided that allows rotational movement of the knob <NUM> in one direction to allow longitudinal movement of the slide assembly <NUM> in one direction within the inner housing 20a (away from a neutral or starting position) to place one of the control wires <NUM>, <NUM> in tension. This allows the sheath distal end to be deflected in a first direction. Whereas, rotation of the knob <NUM> in a second direction releases the tension in that control wire and allows the sheath <NUM> to return to its neutral position. Further rotation of the knob in the second direction allows the slide assembly <NUM> to translate linearly or longitudinally in the other (opposing) direction within the inner housing 20a allowing the other of the two control wires <NUM>, <NUM> to be placed in tension. This allows the sheath distal end to be deflected in a second direction.

More specifically, with reference to <FIG>, handle assembly <NUM> is shown with the slide assembly <NUM> positioned in the neutral position. As the handle knob <NUM> is rotated in a first direction (for example clockwise) as shown in <FIG>, the internal threads <NUM> of the internal knob 10a [illustrated previously in <FIG>] engage with external threads 33a of bolt <NUM> of the slide assembly <NUM>. As shown in <FIG>, rotation of the knob <NUM> translates the slide assembly <NUM> including carriage <NUM> linearly in a proximal direction (P) within the internal housing 20a. In other words the slide assembly <NUM> moves longitudinally towards the proximal end (shown by direction d2) of the handle <NUM>. As the carriage <NUM> moves proximally within the internal housing the proximal face 34a of the carriage <NUM> abuts against the crimp <NUM>. As the knob <NUM> is rotated further in the clock-wise direction, movement of the carriage <NUM> causes the crimp <NUM> to translate proximally, pulling control wire <NUM> and placing it in tension. As the control wire <NUM> is placed in tension it causes a deflection in a distal end portion of the sheath <NUM> to which it is coupled, thus steering the sheath <NUM> in a first direction in a desired plane. In other words, as control wire <NUM> is pulled taut and placed in tension, as shown in <FIG>, it allows the curvature of the sheath tip to change. A deflection of the distal end of the sheath <NUM> in a first direction may be observed. Furthermore, as wire <NUM> is placed in tension, control wire <NUM> remains in a neutral or relaxed state. Additionally, as the carriage <NUM> moves towards the proximal end of the handle <NUM> upon rotation of the knob <NUM>, slack may be created in control wire <NUM>.

Similarly, as the knob <NUM> is rotated in a second direction (for example in a counter-clockwise direction) as shown in <FIG>, the internal threads <NUM> of the internal knob 10a [previously illustrated in <FIG>] engage with external threads 33a of the bolt <NUM> of the slide assembly <NUM>. As shown in <FIG>, rotation of the knob <NUM> causes the slide assembly <NUM> and thus carriage <NUM> to translate linearly within the internal housing 20a in a distal direction (D). As the carriage <NUM> moves distally, the strain or tension in the wire <NUM> is released and a gradual reduction in the distal end deflection of the sheath <NUM> is observed. The sheath <NUM> may reach its neutral position where no stresses are observed in either wire <NUM> or <NUM>.

As the carriage <NUM> moves further distally within the internal housing 20a, the distal face 34b of the carriage <NUM> abuts against crimp <NUM>. As knob <NUM> is rotated further counter-clockwise, the translational movement of carriage <NUM> results in translation of the crimp <NUM>, pulling the control wire <NUM> and placing it in tension as shown in <FIG>. As the control wire <NUM> is placed in tension it causes a deflection in the distal end portion of the sheath or catheter <NUM> to which it is coupled, thus steering the sheath <NUM> in a second direction. In one embodiment, the sheath <NUM> may be manipulated in a second direction that is within the same plane as the first direction. In other embodiments sheath <NUM> may be deflected in a separate plane.

As mentioned above, in some embodiments, a means may be provided for preventing or limiting any slack created in control wire <NUM> from travelling to the segment of control wire <NUM> that is in contact with the pulley <NUM>. As outlined above in <FIG>, as knob <NUM> is rotated in a clockwise direction, carriage <NUM> travels proximally placing tension on control wire <NUM> while releasing tension from control wire <NUM>. In some embodiments, a slack limiting or containing element <NUM> may be provided to limit or contain any slack in control wire <NUM> as tension is removed from the wire <NUM> (or in other words during reverse manipulation of the control wire <NUM>). In some embodiments, the slack limiting or containing element <NUM> engages a proximal portion of the control wire <NUM>. Similarly, as knob <NUM> is rotated in a counterclockwise direction as shown previously in <FIG>, the carriage <NUM> travels distally placing tension on control wire <NUM> and releasing control wire <NUM> from tension. In one embodiment, a slack limiting or containing element <NUM> may be provided to limit or contain slack in control wire <NUM>. In some embodiments, the slack limiting or containing element <NUM> may also limit or contain any slack in wires <NUM>, <NUM> due to compression of the shaft of the steerable sheath <NUM> during use. In some embodiments of the present disclosure the slack limiting or containing element may frictionally engage either one of the control wires <NUM>, <NUM>. In some embodiments, each of the pull or control wires <NUM>, <NUM> may be guided through a slack limiting or containing element <NUM> to reduce slack in a segment of the wires <NUM>, <NUM> or to direct slack away towards a specified direction.

In some embodiments as described above, the slack limiting or containing element <NUM> is coupled to the pulley assembly <NUM> and affects control wire <NUM> that passes through it. The slack limiting or containing element <NUM> functions to prevent any slack generated in wire <NUM> from traveling to or affecting the segment of wire <NUM> that is positioned around the pulley <NUM>. Thus, the segment of control wire <NUM> positioned around the pulley remains substantially taut preventing control wire <NUM> from slipping from around the pulley <NUM>. In one example, the slack limiting or containing element comprises a serpentine friction device 60A as illustrated in <FIG>. The serpentine friction device is further illustrated in <FIG>, <FIG> as described previously.

In one embodiment, as shown in <FIG> a slack limiting or containing element <NUM> is used that may encourage any slack created in wire <NUM> to travel distally (shown by direction d1) through its opening or passage within the slide assembly <NUM>. In other words any slack in the control wire <NUM> or in other words, the slackened control wire <NUM>, moves distally with respect to the carriage <NUM> through its respective opening. This may help prevent slack from affecting the segment of control wire <NUM> around the pulley <NUM>. Thus, the slack limiting or containing element <NUM> may prevent excess slack in the wire around the pulley <NUM> and may help reduce the risk of the control wire <NUM> from derailing from the pulley <NUM>. In some embodiments, where the pulley <NUM> has a groove to guide control wire <NUM> around pulley <NUM>, the slack limiting or containing element <NUM> may function to maintain the control wire <NUM> in position.

In one example, the handle or device <NUM> includes a serpentine friction device 60A as outlined herein above and as illustrated in <FIG>, <FIG>. The serpentine friction device 60A as further illustrated in <FIG>, allows for one-way travel of the wire. The wire can travel in one direction (e.g. d1, distal direction) with greater ease that in the second direction (proximal direction d2). When the knob <NUM> is rotated clockwise, wire <NUM> is placed in tension, and slack is created in control wire <NUM>. The serpentine friction device 60A prevents control wire <NUM> from slipping or travelling proximally, thus the segment of control wire <NUM> around the pulley <NUM> remains taut. In other words tension is maintained in the segment of control wire <NUM> around the pulley <NUM> which minimizes the risk of control wire <NUM> from derailing from the pulley <NUM>. In other words friction provided by the serpentine friction device 60A restricts movement of the control wire <NUM> in the proximal direction and ensures any slack in control wire <NUM> is guided distally. The friction between control wire <NUM> and pins <NUM> is sufficient such that in the absence of an active pull force on the control wire <NUM>, the control wire <NUM> cannot overcome the force of friction. Thus, control wire <NUM> cannot travel in the proximal direction as shown in <FIG> and any slack created in wire <NUM> travels in the distal direction d1 through its respective opening. However, when tension is applied on the control wire <NUM> as shown in <FIG> upon counter-clockwise rotation of the knob <NUM> (after the slide assembly <NUM> has reached its neutral position), sufficient force is applied such that it overcomes the force of friction present between wire <NUM> and pins <NUM> thus allowing movement of the wire around the pulley <NUM> to allow control wire <NUM> to be placed in tension. Control wire <NUM> is actively pulled in the distal direction d1.

In one embodiment the slack limiting or containing element comprises a biased friction device 60B comprising a friction block <NUM> and clip <NUM> as described herein above with respect to <FIG>. During operation, when the knob <NUM> is rotated clockwise tension is placed on control wire <NUM> through proximal movement of slide assembly <NUM> from its neutral position and slack is generated in control wire <NUM>. In the absence of tension applied to control wire <NUM> the force exerted by the friction block <NUM> and clip <NUM> is sufficient to prevent proximal movement of the control wire <NUM> such that slack created in control wire <NUM> cannot be transmitted to the segment of control wire <NUM> around the pulley <NUM>. In other words the segment of wire <NUM> around the pulley <NUM> remains in tension. However, upon counter-clockwise rotation of the knob the slide assembly <NUM> moves distally back to its neutral position and upon further counter-clockwise rotation of the knob, the slide assembly <NUM> moves distally from its neutral position and force is applied to wire <NUM>. When sufficient force is applied to wire <NUM> distally, such that the applied force is greater than the frictional force exerted by friction device 60B onto control wire <NUM>, the control wire <NUM> can translate longitudinally under tension. In one example, the control wire <NUM> can translate longitudinally in a distal direction under counter clockwise rotation of the knob <NUM>. In summation, the longitudinal movement of the control wire <NUM> in a proximal direction may be prevented under clockwise rotation of the dial as control wire <NUM> is released from tension and control wire <NUM> is placed in tension. Thus, slack generated in control wire <NUM> can be guided away from the pulley using the biased friction device 60B, minimizing the risk of control wire <NUM> falling off from the pulley <NUM>.

Similar to the operation of the biased friction device 60B described above, as shown in <FIG>, the resilient friction device 60C comprising elastomer block 67a frictionally engages the control wire <NUM> within the slit 67b between legs <NUM> of the elastomer block 67a. The friction device 60C permits distal movement of control wire <NUM> under tension as the slide assembly moves distally, but provides a sufficient frictional force such that the wire control wire <NUM> is unable to move longitudinally in a proximal direction when it is in a relaxed state during proximal movement of the slide assembly <NUM>. Thus, when control wire <NUM> is inactive (not under tension), the segment of control wire <NUM> around the pulley <NUM> still remains taut as slack is not transmitted to this segment. This is a result of the frictional forces imparted on control wire <NUM> by the resilient friction device 60C.

In one embodiment, as shown in <FIG>, the control handle <NUM> may allow the bi-directional deflection of the sheath <NUM>. In one example, in the neutral position the carriage <NUM> may be positioned distal of the center of the inner housing 20a. In such an example, a sheath tip curvature in the range of about <NUM>-<NUM>° may be achieved when the knob <NUM> is rotated in a clockwise direction and about <NUM>-<NUM>° sheath tip curvature may be achieved when the knob <NUM> is rotated in a counter-clockwise direction. In one embodiment, a left-hand tip response may be observed with a clock-wise or right hand knob rotation. In other embodiments, a right-hand tip response may be observed with a clock-wise or right hand knob rotation. The degree of curvature that is achieved in each direction may be adjustable by changing the neutral or starting position of the slide assembly <NUM> in combination with a slide limiting element for limiting the range of translation of the slide assembly <NUM>. In some embodiments, the sheath may be defected to about <NUM> degrees in at least one of the two deflection directions. In other embodiments a greater than <NUM> degree curvature may be achieved.

As outlined above, the track 21a within the inner housing 20a can additionally function as a slide stop to restrict the movement of the slide assembly <NUM> to allow for a desired deflection of the sheath <NUM>. As shown in <FIG>, once the slide assembly <NUM> (for example a raised projection 31a of the slide assembly <NUM> shown in <FIG>) reaches the end of the track it abuts against a wall 21a' at the end of the groove or track 21a, thereby stopping or limiting linear motion of the slide assembly.

In some embodiments, the length of the track 21a may be adjustable to alter the degree of deflection that may be provided in the sheath <NUM> using the handle <NUM>. Thus in some embodiments a shorter track 21a may be provided in the inner housing 20a as shown in <FIG>, providing a shorter translation distance for the slide assembly <NUM> resulting in a more limited range of motion for the sheath <NUM>. In other words the sheath <NUM> is provided with a reduced maximum deflection angle or stroke length. The track 21a may be shortened through insertion of a pin 21z as shown in <FIG>. Once a portion of the slide assembly <NUM> abuts against the pin 21z, the pin 21z prevents further translation of the slide assembly. In other embodiments a longer track 21a may be provided in the inner housing 20a as shown in <FIG>, providing a longer translation distance for the slide assembly <NUM> resulting in a wider range of motion for the sheath <NUM>. In other words the sheath <NUM> may be provided with a greater maximum deflection angle or stroke length. In general, the length of the track 21a may restrict the distance the slide assembly <NUM> can travel in a given direction (either in the proximal and/or distal direction) which may be used to restrict the amount of deflection of the sheath <NUM>.

In one specific example, the slide stop may be positioned proximal to the slide assembly <NUM> and may restrict translation of the slide assembly <NUM>. However, this restriction in the movement of the slide assembly <NUM> may be used to limit the deflection of the sheath <NUM> in either proximal and/or the distal direction. This may be achieved by altering the neutral position of the slide assembly <NUM>. A neutral position [N] of the slide assembly is illustrated in <FIG>. In one specific example, the neutral or starting position of the slide assembly <NUM> is adjustable which may determine the allocation of the range of motion of the slide assembly <NUM> in each of the distal and proximal directions. In other words adjusting the neutral or initial position of the slide assembly <NUM> determines the distance the slide assembly <NUM> may travel in each of the distal and proximal directions determining the amount of deflection of the sheath <NUM> in each of its deflection directions. In some embodiments, the neutral position may be adjusted in combination with the use of a slide stop to provide a sheath <NUM> capable of <NUM>° degrees of rotation in each of its deflection directions (or in other words, sheath <NUM> has a stroke length of <NUM>° degrees in each direction). Alternatively, sheath <NUM> may be capable of undergoing a <NUM>° degrees of deflection in each direction. In other embodiments the sheath <NUM> may have a deflection angle of <NUM>° degrees in one direction and a deflection angle of <NUM>° degrees in the other direction. Thus, the sheath <NUM> may have a matching radius of curvature/deflection or stroke length in both directions or a varying radius of curvature/deflection in each direction. In still another alternative, the sheath has a deflection angle of up to about <NUM> degrees in at least one of its deflection directions. In other embodiments the sheath may have a deflection angle that is more than <NUM> degrees. In embodiments of the present invention as described herein, the slide limiting element is a component that is separate from the slide assembly <NUM>.

In some embodiments as described previously, the slide limiting element comprises a tubular slide stop 21b as shown in <FIG>, <FIG>, <FIG> and <FIG>. The use of a longer tubular slide stop 21b results in a more restricted movement of the slide assembly <NUM>. In one example, the tubular slide stop 21b is positioned proximal to the slide assembly <NUM>. In some embodiments the tubular stop 21b comprises a relatively hard material and is substantially rigid such that it does not yield substantially under application of force. In one such example, upon clockwise rotation of the knob <NUM>, as slide assembly <NUM> translates proximally within the inner housing 20a the slide assembly <NUM> abuts against the wall 21b' of a rigid tubular slide stop 21b preventing further translation of the slide assembly <NUM>. This provides tactile feedback which may be experienced as a hard stop by the user. This may help indicate to the user that the maximum deflection of the sheath <NUM> has been achieved. Alternatively, in some embodiments as described above the tubular slide stop 21b may comprise a softer or resilient material that yields gently when the slide assembly <NUM> abuts against the wall 21b' preventing further translation of the slide assembly <NUM>. This provides tactile feedback which may be experienced as a soft or gentle stop by the user. This may indicate to the user that the sheath <NUM> is close to reaching its maximum deflection. In one example, the tubular slide stop 21b may have a diameter that is substantially greater than the outer diameter of the sheath <NUM> over which it is mounted. In one embodiment as shown in <FIG>, the tubular slide stop 21b is positioned distal to the slide assembly <NUM> and is in the form of a collar 21y defining proximal wall 21y'. In one example the collar 21y comprise a rigid material. For example under counter clockwise rotation of knob <NUM>, slide assembly <NUM> travels distally and is stopped by the wall 21y' of the collar 21y.

In some embodiments, where the tubular slide stop 21b has an inner diameter that is greater than the outer diameter of the sheath <NUM>. The tubular slide stop 21b may help retain a curve of a stiff medical device such as a rigid needle that may be advanced through the sheath <NUM>. The tubular slide stop 21b may prevent the curve from being straightened by reducing constraint against the sheath <NUM>.

As described previously, in some examples the slide limiting element or slide stop comprises a bar 21c extends with the inner housing 20a along a transverse plane. In one example, the bar 21c is positioned between the slide assembly <NUM> and the pulley assembly <NUM>. The bar 21c impedes or restricts the movement of the slide assembly <NUM> as it abuts against wall 21c' of the bar, thus restricting the total translation distance available to the slide assembly <NUM>. This consequently restricts the amount of tension that can be placed on one or more of the wires <NUM>, <NUM> and thus limiting the deflection of the sheath <NUM>.

As described above, in some examples the slide limiting element may comprise a rivet extending into the lumen of the inner housing 20a at a point along the track 21a. The rivet 21d may be positioned through an opening in the track 21a and held in frictional engagement therein. The rivet blocks the path of the translating slide assembly <NUM> and effectively shortens the length of the track 21a. In one example of this, there may be multiple openings or holes provided within the track 21a and the position of the rivet 21d may be adjustable. In other words, the rivet 21d may be positioned in any one of the openings. This may allow enable the user to vary the length of the track 21a and the desired translation distance of the slide assembly <NUM> and consequently the desired distal end deflection of the sheath <NUM>. In some embodiments, the rivet 21d works in conjunction with a secondary component to block the movement of the slide assembly <NUM>. The rivet secures the secondary component within the lumen of the inner housing 20a. In some examples of this, the longitudinal length of the secondary component may be adjustable to vary the translation range of the slide assembly <NUM> and consequently the deflection of the sheath <NUM>. Alternatively, an actuator may be provided for example for activating a mechanical means for changing the length of the secondary component to adjust the maximum allowable translation of the slide assembly <NUM>.

As discussed above, and as shown in <FIG>, in a still further alternative, the slide restricting component or slide stop may comprise an extension 21e of the pulley assembly <NUM> that extends distally into the lumen of the inner housing 20a. The extension 21e functions to impede movement of the slide assembly as described herein above to limit the defection of the sheath <NUM>.

With reference now to <FIG>, in accordance with one embodiment of the present disclosure, a catheter control system or handle <NUM> is illustrated for use with a bidirectional steerable sheath or catheter <NUM>. As shown in <FIG>, the steerable catheter handle <NUM> is similar structurally and in operation to the handle <NUM> discussed previously. Handle <NUM> comprises an actuator comprising a knob <NUM> (comprising inner and outer knobs 10a, 10b respectively) that is coupled to a housing <NUM> (comprising inner and outer housings 20a, 20b). The inner knob 10a has internal threads that co-operate with external threads <NUM> of the bolt <NUM> of the slide assembly <NUM>, shown in <FIG>. Upon actuation in a first direction, for example upon rotation of the knob <NUM> in a first rotational direction, the handle <NUM> is operable to move slide assembly <NUM> in a first linear direction within the inner housing 20a to tension one of the two control wires <NUM>, <NUM> that are coupled to the carriage <NUM> of the slide assembly <NUM> via crimps. Upon actuation in a second direction, for example rotation of the knob <NUM> in a second rotational direction the handle <NUM> is operable to move the slide assembly <NUM> in a second linear direction within the inner housing 20a to tension the other of the two control wires <NUM>, <NUM>.

In some embodiments, the sheath or catheter <NUM> may have a total length that is equal to between about <NUM> to about <NUM>, and more specifically that is equal to about <NUM>. In one such example, the usable length of the catheter or sheath <NUM> (which the length of the catheter that is distal to the handle <NUM>) may be about <NUM> to about <NUM>. More specifically, the usable length is equal to about <NUM>. In another example the usable length of the catheter <NUM> may be equal to about <NUM> to about <NUM>, and more specifically the usable length is equal to about <NUM>. In one such example, the total length of the sheath may be equal to between about <NUM> to about <NUM>, and more specifically the total length may be equal to about <NUM>. In alternative embodiments, catheter <NUM> may have a length that varies from between about <NUM> to about <NUM>, with a usable length that varies from between about <NUM> to about <NUM>. In still other embodiments, the catheter <NUM> may have a length that is less than about <NUM> with a usable length that is less than about <NUM>. In still other embodiments, the catheter may have a length that is greater than about <NUM> with a usable length that is greater than about <NUM>. In further embodiments catheter <NUM> may a have other lengths and usable lengths as may be known to a person skilled in the art.

Some examples of the present disclosure comprise a unidirectional control system for providing unidirectional control of a bi-directional steerable catheter having at least two deflection directions, the control system comprising an actuator coupled to at least two control wires, wherein the actuator actively actuates the first control wire to tension the first control wire to deflect the bi-directional steerable catheter from a neutral position in a first deflection direction, and wherein the actuator actively actuates the second control wire to tension the second control wire to un-deflect the steerable catheter towards its neutral position to allow the bi-directional steerable catheter to return to its original position.

In the embodiment shown in <FIG>, the handle <NUM> additionally comprises a deflection limiting mechanism for limiting deflection of the steerable catheter <NUM> in one of its two deflection directions. In some embodiments the deflection limiting mechanism comprises a slide limiting mechanism such as a slide limiting element that functions to limit the movement of the slide assembly <NUM> in one of its two linear directions within the inner housing 20a in order to limit or restrict the deflection of sheath <NUM> in one of its deflection directions. As shown in <FIG>, in some embodiments, the slide limiting element that is used to limit the deflection of the catheter <NUM> may comprise a slide stop 221b that is positioned within the lumen <NUM> of the inner housing 20a. In a specific example, the slide stop 221b comprises a tubular slide stop similar to the tubular slide stop 21b (shown in <FIG>, <FIG>, <FIG>) discussed earlier with reference to <FIG>. In some embodiments, as illustrated in <FIG>, the tubular slide stop 221b is hollow to accommodate the sheath <NUM> allowing the sheath <NUM> to extend to the proximal end of the handle <NUM>. In one embodiment, the tubular slide stop 221b comprises a relatively rigid HDPE material. In one example, the tubular slide stop 221b has a length [L] of between about <NUM>" to about <NUM>" (<NUM> - <NUM>). In one particular example, the inner diameter (ID) of the slide stop 221b ranges from between about <NUM>" to about <NUM>" (<NUM> - <NUM>) and the outer diameter (OD) ranges from between about <NUM>" to about <NUM>" (<NUM> - <NUM>). In a particular example, the slide stop 221b has a length that is equal to about <NUM>" (<NUM>) with inner and outer diameters equal to about <NUM>" (<NUM>) and <NUM>" (<NUM>) respectively.

More specifically, with reference again to <FIG>, in the illustrated embodiment, the slide stop 221b is positioned proximal to the slide assembly <NUM> of the handle <NUM> and functions to restrict proximal movement of the slide assembly <NUM> upon actuation of the knob <NUM> of the handle <NUM>. In some embodiments, the position of the slide stop 221b within the inner housing 20a may be adjustable. As a result the deflection of the bi-directional steerable sheath or catheter <NUM> in one of its steering or deflection directions (also referred to as the second deflection direction) is substantially eliminated. However, the distal movement of the slide assembly <NUM> remains unrestricted. Thus, when the knob <NUM> is rotated counter-clockwise the slide assembly <NUM> moves distally within the lumen <NUM> of the inner housing 20a, to allow the slide assembly <NUM> to pull the control wire <NUM> to cause a deflection of the steerable sheath or catheter <NUM> in the other of its two steering or deflection directions (or the first deflection direction). Once the knob <NUM> is then rotated clock-wise, tension in wire <NUM> is released until slide assembly <NUM> returns to its neutral position and the catheter <NUM> returns to its nominal position. Further clock-wise rotation of the knob results in limited or restricted proximal movement of the slide assembly <NUM> as it abuts against the tubular slide stop 221b which results in a limited amount of force to be exerted on control wire <NUM> and the deflection of the catheter in the second deflection direction is substantially eliminated. Therefore the use of a slide limiting element (e.g. slide stop 221b) within handle <NUM> permits unidirectional use of a bi-directional steering catheter by limiting the proximal movement of the slide assembly to substantially eliminate deflection of the catheter in its second deflection direction, while permitting distal movement of the slide assembly to permit deflection of the catheter in its first deflection direction.

As discussed previously, and presently shown in <FIG>, the curvature of sheath <NUM> that can be achieved in each of the deflection directions, can also be adjusted by changing the neutral position of the slide assembly <NUM> in combination with the use of a slide limiting element. The neutral position of the slide assembly is the position where both control wires <NUM>, <NUM> are in their un-tensioned or relaxed state. As illustrated in <FIG>, the slide limiting element (for example, the tubular slide stop 221b) limits the total available translation range [R] of the slide assembly <NUM> within the lumen <NUM> along the window <NUM> of the inner housing 20a. The neutral position of the slide assembly <NUM> may then be adjusted in order to allocate the range of motion of the slide assembly <NUM> in each of the proximal and distal directions.

In order to impart unidirectional functionality to a bi-directional steerable catheter of the present disclosure, the neutral position is set such that the allocated range of motion of the slide assembly in one of the two translation directions is substantially restricted. In the embodiment shown in <FIG>, the neutral position [N] is set to be adjacent the proximal boundary of the translation range [R] at a distance [S] from the slide stop 221b, thus substantially restricting the translation of the slide assembly in the proximal direction. In other words, there is limited room for movement of the slide assembly <NUM> in the proximal direction (as noted by the limited amount of space or distance [S] between the slide assembly <NUM> and the distal wall 221b' of slide stop 221b). As a result, the deflection of the sheath or catheter <NUM> in the second deflection direction is substantially eliminated, allowing the handle <NUM> to impart a unidirectional functionality to the catheter <NUM> in its first deflection direction allowing it to achieve a first deflected state or position.

As mentioned previously, during use of the control system or handle <NUM>, when the knob <NUM> is rotated counter clockwise, the slide assembly <NUM> moves distally from its neutral position, to tension wire <NUM> to deflect the catheter <NUM> in its first deflection direction. As the knob <NUM> is then rotated clockwise, slide assembly <NUM> returns to its neutral position and tension is removed from the control wire <NUM> to allowing the catheter <NUM> to return close to its un-deflected or nominal shape or state/position. However, resistance observed due to friction between the control wire <NUM> and the body of the catheter (or sheath) <NUM> along the length of the catheter <NUM> prevents the catheter <NUM> from returning substantially to its un-deflected or nominal shape. A slight curl or bend is still observed in the body of the catheter <NUM>. Thus, there is a need to overcome friction between the control wire <NUM> and the catheter <NUM> along the length of the catheter <NUM> in order to allow the catheter <NUM> to return to its nominal shape. In order to overcome this friction between the catheter <NUM> and control wire <NUM>, the opposing control wire <NUM> is activated by rotating the knob <NUM> further in the clockwise direction. This allows the slide assembly <NUM> to travel proximally from its neutral position by distance [S] until it abuts against slide stop 221b, which allows catheter <NUM> to be uncurled or in other words allows the catheter to return to its un-deflected or nominal state or position by overcoming the force of friction between the control wire <NUM> and catheter <NUM>. In some embodiments, the distance [S] travelled by the slide assembly <NUM> to uncurl the catheter <NUM> (which is equivalent to the neutral position of the slide assembly <NUM> measured from the slide stop 221b to a proximal wall of the slide assembly <NUM>) is about <NUM>. In some such examples, distance [S] may be range from between about <NUM> to about <NUM>. Thus, in one particular embodiment, the neutral position of the slide assembly <NUM> is set such that it is sufficient to allow the catheter to return substantially to its nominal shape or position as the catheter uncurls upon clockwise rotation of the knob <NUM>. However, additional clockwise rotation of the knob <NUM> is unable to deflect the catheter in its second deflection direction to achieve a second deflected state or position as further movement of the slide assembly is restricted by the slide stop 221b. Therefore, the deflection of the catheter <NUM> in the second deflection direction is substantially restricted or limited. As such there is no observed deflection of the catheter <NUM> in the second deflection direction. Thus, the control system or handle <NUM> of the present disclosure permits unidirectional use of a bi-directional steerable catheter.

In some embodiments, as illustrated in <FIG>, the slide stop 221b may be utilized, as above, in a position that is proximal to the slide assembly <NUM>. However, unlike the embodiment of <FIG>, the slide stop 221b is used to limit the movement of the slide assembly in the opposite direction, i.e. the distal direction to substantially restrict the deflection of the sheath or catheter <NUM> in its first deflection direction. This may be achieved by altering the neutral position [N] of the slide assembly <NUM> as illustrated in <FIG>. As shown, the neutral position is set to be substantially adjacent to the distal boundary of the translation range [R] at a distance [S] from the distal wall 20a' of the window <NUM> of the inner housing 20a. The distance [S] is measured from the distal wall 20a' of window <NUM> to the distal wall of the housing <NUM> of the slide assembly <NUM>. In one example, the distance [S] is about <NUM>. In some such examples, the distance [S] may range from about <NUM> to about <NUM>. This neutral position [N] substantially restricts the translation of the slide assembly in the distal direction upon counter-clockwise rotation of the knob <NUM>. As a result minimal force is exerted on the control wire <NUM> such that deflection of the catheter <NUM> in the first deflection direction is substantially eliminated.

As an overview of the operation of the illustrated embodiment of <FIG>, starting from its neutral position [N] the slide assembly <NUM> is free to translate proximally within the handle <NUM> upon clockwise rotation of the knob, until the slide assembly <NUM> abuts against the distal wall 221b' of the slide stop 221b. This allowing force to be exerted on control wire <NUM> deflecting catheter <NUM> in its second deflection direction, thus imparting unidirectional functionality to the bi-directional steerable catheter <NUM>. The inner knob 10a may then be rotated counter-clockwise until tension is removed from control wire <NUM> and the slide assembly <NUM> returns to its nominal position [N]. Similar to the embodiment discussed previously, the catheter <NUM> may be deflected close to its nominal shape but friction between the control wire <NUM> and the catheter <NUM> along the length of the catheter <NUM> may prevent the catheter <NUM> from returning completely to its nominal shape and a slight curl or bend may remain in the catheter <NUM>. As the knob <NUM> is then rotated further counter-clockwise the slide assembly <NUM> moves distally until it abuts against the proximal wall 20a' of the window <NUM> of the inner housing 20a (which prevents it from travelling further distally) which allows the catheter to return substantially to its nominal position or shape but prevents the catheter <NUM> from deflecting substantially in its first deflection direction.

Alternatively, the slide limiting element may be positioned distal to the slide assembly <NUM> in order to permit unidirectional use of the bi-directional steering catheter by substantially restricting the distal movement of the slide assembly. In one such example, the slide limiting element may be positioned distal to the carriage <NUM> of the slide assembly <NUM> (similar to collar 21y illustrated in <FIG>). The collar substantially restricts the distal movement of the slide assembly <NUM> upon counter clockwise rotation of the knob, in order to substantially eliminate deflection of the sheath or catheter <NUM> in its first deflection direction. However, the slide assembly <NUM> is free to move proximally within the handle upon clockwise rotation of the knob in order to pull control wire <NUM> to cause deflection of the catheter in its second deflection direction. Thus, the slide limiting element may alternatively be used to permits unidirectional use of a bi-directional steering catheter by limiting the movement of the slide assembly to substantially eliminate deflection of the catheter in its first deflection direction while permitting deflection in its second deflection direction. In some embodiments, the collar 21y may be positioned to permit limited distal movement of the slide assembly <NUM> to permit straightening or uncurling of the catheter after it has been deflected in its second deflection direction.

As an alternative, any of the slide limiting elements discussed herein above in <FIG> may be used to substantially restrict the translation of the slide assembly in one of its linear translation directions to permit unidirectional use of the bi-directional steerable catheter.

Thus, as described hereinabove, embodiments of the present disclosure provide a rotatable mechanism for controlling deflection of two control or pull wires using one moving member to allow a catheter or other medical device to be steered in two different directions. The rotation of the knob in a first rotational direction moves the member along one longitudinal direction to allow one of the two control wires to be placed in tension (to deflect the catheter to a first orientation) and rotation of the knob in an opposite rotational direction (about a longitudinal axis of the handle) moves the member along the opposite longitudinal direction to allow the other of the two control wires to be placed in tension (to deflect the catheter to a different orientation).

In one broad aspect, embodiments of the present disclosure provide a control system for bi-directional control of a steerable catheter, the catheter including at least two control wires, a distal end of each of the control wires being coupled to the catheter at a distal region thereof, the control system comprising: a housing coupled to the catheter; a slide assembly positioned within the housing and operable to translate linearly therein; a proximal portion of each of the at least two control wires being mounted or positioned through the slide assembly; and a control knob rotatably coupled to the housing for linearly translating the slide assembly, thereby enabling the slide assembly to separately manipulate each of said at least two control wires to effect a change in a deflection of said catheter; wherein rotation of the control knob in a first rotational direction causes distal movement of the slide assembly in a first linear direction causing the slide assembly to tension one of said at least two control wires thereby effecting a change in the deflection of said catheter in a first deflection direction and wherein rotation of the knob in a second rotational direction causes proximal movement of the slide assembly in a second linear direction causing the slide assembly to tension the other of said at least two control wires thereby effecting a change in the deflection of said catheter in a second deflection direction.

In another broad aspect, embodiments of the present disclosure provide a slack limiting or containing device for use with a steerable catheter control system having at least one control wire, the control system comprising a mechanism for tensioning the at least one control wire for deflecting the steerable catheter and for releasing tension there-from, wherein the slack limiting device is engageable with a portion of the at least one control wire for limiting the slack therein when tension is released from the at least one control wire.

In yet another broad aspect, embodiments of the present disclosure provide a slack limiting device for use with a steerable catheter control system having at least one control wire, the control system comprising a mechanism for tensioning the at least one control wire for deflecting the steerable catheter and for releasing tension there-from, wherein the slack limiting device is engageable with a portion of the at least one control wire for limiting the slack therein when tension is released from the at least one control wire.

In a further broad aspect, embodiments of the present disclosure provide a slide limiting or restricting mechanism for use with a steerable control system for a steerable catheter having at least one control wire, the steerable control system comprising a handle having a housing with a single slide assembly disposed within the housing that has the at least one control wire coupled thereto, and a rotatable knob for moving the single slide assembly to cause a deflection of the catheter by tensioning the at least one control wire, the slide limiting mechanism comprising: a slide limiting or restricting element positioned within the handle to limit a linear movement of the single slide assembly in a first linear direction within the handle upon rotation of the knob in a first rotational direction, to limit the tension placed on the at least one control wire, for limiting the deflection of the catheter in a first deflection direction.

In an additional broad aspect, examples of the present disclosure provide a method for using a control system to deflect a steerable catheter, the control system comprising a handle having a housing and a single slide assembly disposed within the housing that is operable via a knob, the steerable catheter comprising at least two control wires that are passed through the single slide assembly for engaging therewith, for steering the catheter in opposite deflection directions, the method comprising: moving the single slide assembly in a first linear direction to place one of the at least two control wires in tension by rotating the knob in a first rotational direction, in order to deflect the catheter in a first deflection direction; and moving the single slide assembly in a second linear direction opposite to the first linear direction to place the other of the at least two control wires in tension by rotating the knob in a second rotational direction, in order to deflect the catheter in a second deflection direction.

In still an additional broad aspect, examples of the present disclosure provide a control system for providing unidirectional control of a bi-directional steerable catheter having at least two deflection directions, the control system comprising an actuator for permitting deflection of the bi-directional steerable catheter in a first deflection direction upon actuation in a first direction and comprising a deflection limiting mechanism for substantially limiting the deflection of the bi-directional steerable catheter in a second deflection direction by limiting actuation in a second direction.

As a features of these broad aspects, embodiments of the present disclosure provide a handle which includes a rotatable mechanism for controlling tension of two pull wires. Rotation of the mechanism in one direction tensions and thus applies a pulling force on a first pull wire, whereas rotation in the opposite direction tensions and thus applies a pulling force on the second pull wire. As is further described herein, such tensioning of the wires can be used to torque or deflect a functional end of a medical device connected to the handle.

Some such embodiments comprise a handle for bi-directional control of a catheter, the handle comprising: a housing; a control knob rotatably coupled to the housing for co-operatively engaging with a slide positioned within said housing; a first control wire and a second control wire, a proximal end of each of said control wires being coupled to the slide and a distal end of each of said control wires being coupled to the catheter; wherein rotation of the knob causes the slide to translate linearly within said housing to change the tension in one of said first and second control wires to effect a change in the deflection of said catheter.

As another feature of these embodiments, the slide comprises at least three openings/passages extending longitudinally at least partially through the slide to allow said first and second control wires to be passed there-through to be coupled thereto.

In a further example of this feature, the at least three openings/passages comprise: a first opening and a second opening, allowing the first and the second control wires to pass proximally there-through, the first control wire being coupled to a proximal face of said slide, a third opening allowing the second control wire to additionally pass distally there-through via a pulley to be coupled to distal face of the slide.

In another example of this feature, the slide defines a hollow interior between a slide distal end defining said distal face and a slide proximal end defining said proximal face, to allow free passage for/to prevent strain on said first and second control wires.

In still a further example of this feature, said first and third openings/passages housing said second control wire are positioned towards the exterior of the slide to prevent stress on the second control wire and to prevent the slide from rotating within the housing.

As an additional feature of this broad aspect, the slide comprises a cap and a base. In an example of this feature, the cap comprises teeth that co-operatively engage with grooves within the slide to form said at least three openings. In a further example of this feature, the slide further comprises a central opening to allow the first and second control wires to pass there-through to allow the wires to be routed through the grooves within the slide. In a particular example of this the central opening is in the form of a groove within the base.

As still an additional feature of this broad aspect, the handle comprises a slack limiting/containing element for limiting/containing slack in at least one of the first and second control wires.

As a further feature of this broad aspect, the handle further comprises a means for coupling the pull wires to opposite sides of the slide so that motion of the slide in one direction will apply tension to one wire while motion of the slide in the other direction will apply tension to the other wire. In one particular example, one of said first and second control wires are coupled to the slide through/via a pulley. In an example of this feature, the handle comprises a pulley guide to maintain engagement of the second control wire with said pulley. In an additional example of this feature, the handle comprises a height guide to maintain engagement of the second control wire with said pulley.

As still an additional feature of this broad aspect, the handle further comprises a groove extending longitudinally within the housing for receiving a projection within the slide to guide the slide within the housing.

As still an additional feature of this broad aspect, the handle comprises a resistance/frictional element within the inner knob and the outer knob to maintain a position of the slider to maintain a curve/deflection of the catheter. In a further example of this feature the resistance/frictional element comprises an o-ring.

As another feature of this broad aspect, the inner housing comprises a slide limiting element to limit the translation of the slide within the housing to limit the tension placed on at least one of said first and second control wires.

As a feature of this broad aspect, the slide limiting element is adjustable. In an example of this feature, wherein an initial position of the slide is variable.

In a further broad aspect, embodiments of the present disclosure comprise a steerable catheter having one or more control wires comprising a slack limiting/containing element for limiting/containing slack in at least one of the one or more control wires.

As a feature of this aspect, the slack limiting/containing element comprises a friction element.

The embodiments of the invention described above are intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.

Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

Claim 1:
A control system for bi-directional control of a steerable catheter, the catheter (<NUM>) including at least two control wires (<NUM>, <NUM>), a distal end of each of the control wires being coupled to the catheter at a distal region thereof, the control system comprising:
a housing (<NUM>) having a distal end and a proximal end, wherein the housing (<NUM>) is coupled to the catheter;
a slide assembly (<NUM>) positioned within the housing and operable to translate linearly therein;
a proximal portion of each of the at least two control wires being positioned through the slide assembly;
wherein one of the at least two control wires is directly coupled to the slide assembly and the other of the at least two control wires is indirectly coupled to the slide assembly via a direction reversing element (<NUM>'), and
further comprising a control knob (<NUM>) rotatably coupled to the housing (<NUM>) at said distal end thereof for linearly translating the slide assembly, thereby enabling the slide assembly to separately manipulate each of said at least two control wires to effect a change in a deflection of said catheter;
wherein rotation of the control knob (<NUM>) in a first rotational direction causes distal movement of the slide assembly in a first linear direction causing the slide assembly to tension one of said at least two control wires thereby effecting a change in the deflection of said catheter in a first deflection direction and wherein rotation of the knob in a second rotational direction causes proximal movement of the slide assembly in a second linear direction causing the slide assembly to tension the other of said at least two control wires thereby effecting a change in the deflection of said catheter in a second deflection direction,
characterized in that said control system further comprises a slack limiting element (<NUM>) comprising a friction device for frictionally engaging the one of the at least two control wires for limiting slack therein.