Patent Description:
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:.

Some medical procedures may require the use of a steerable sheath or catheter in order to reach a desired location within a patient's body in order to treat the patient. The steerable sheath or catheter may be deflectable upon actuation of a steerable sheath or catheter control handle. Some such steerable catheter control handles comprise actuation mechanisms that are actuable to deflect the sheath by actuating of one or more control or pull wires that are coupled to the sheath. In some such examples, the one or more pull wires may be coupled to the sheath along a distal segment of the sheath, allowing the actuator to deflect a distal portion of the sheath at the desired curvature.

However, some such steerable sheaths may not be able to withstand a high degree of deflection of the sheath, and/or repeated actuation of the sheath without failure. In some such examples, high degree of deflection of the steerable sheath and/or repeated deflections of the steerable sheath may result in failure of the steerable sheath at the point of contact of the pull wires with the sheath. Furthermore, such sheaths may not be able to perform adequately without failure when one or more devices are used in conjunction with the steerable sheath and the steerable sheath is used to curve the assembly. In some such examples, the steerable sheath may be used with a needle and/or a dilator positioned within the steerable sheath, and the steerable sheath may be curved. Some such prior art systems may observe failure at the pull wire connection at the sheath, due to the stress or strain put on the sheath from curving the one or more rigid devices along with it due to higher forces and greater actuation required to deflect the sheath.

The inventors of the present invention have discovered a unique problem associated with prior art steerable sheath assemblies that result in failure at the point of contact between the pull wires and the sheath and presented a novel solution to solve the same. The present inventors have discovered that in prior systems the failure at the point of contact between the pull wires and the sheath is a result of the weakness in the portion of the shaft of the sheath where the pull wires are connected.

In some embodiments of systems that use pull rings to connect the pull wires to the sheath, the present inventors have discovered that there is weakness in the segment of the shaft at the point/interface where the pull wires are connected to the sheath, via the pull ring. The present inventors have additionally discovered that the weakness may result in displacement and or pivoting of the pull-wire out of position about the point of attachment of the pull ring to the sheath such as the pull-ring anchor hole, upon deflection of the steerable sheath. As such the weakness in the shaft may result in displacement of the coupling between the pull wires and the shaft. In some cases the pull ring may be able to pivot or displace proximally behind a deflectable section of the sheath that may be immediately proximal to the coupling [such as a pull ring]. In some such situations, as the pull wires are deflected, the angle between the pull wire and the coupling [such as pull-ring] may become greater than <NUM> degrees due to weakness in the shaft resulting in curvature at the joint between the pull-wires and the pull-ring which may be a weld-joint, which may result in breaking of the weld-joint due to breakage.

In some embodiments, the coupling [such as a pull-ring] may be able to pivot at the pull-ring anchor hole which is a hole through which the polymer layers of shaft of the sheath through flow to form a peg to keep the pull-ring in place, once the pull wires are deflected, resulting in rotational displacement of the pull-ring.

As will be presently described, the present inventors have additionally discovered a unique solution to solving the problem by providing a means for preventing displacement of the coupling. The present inventors have discovered and invented embodiments for reinforcing the area of the shaft of the steerable sheath where the pull wires are coupled, to help minimize failure at the interface between the pull wires and sheath.

In systems where a pull ring is used to couple one or more pull wires to the shaft of the steerable sheath, present inventors have discovered unique solutions to reinforce an area of the steerable sheath shaft where the pull ring is located.

The invention is described in the claims. In one broad aspect, embodiments of the present invention comprise a reinforced steerable sheath assembly that is usable with an actuator comprising: a shaft section defining a sheath that is operable to be deflected, and one or more pull wires that are coupled to the sheath via a coupling at a point of contact between the pull wires and the sheath. The pull wires are operable to be coupled to the actuator for actuating the pull wires. The reinforced steerable sheath assembly further comprises a means for preventing displacement of the coupling, wherein the means for preventing displacement to minimize failure at the coupling at the point of contact between the pull wires and the sheath upon actuation of the pull wires upon actuation of the actuator to deflect the sheath.

As a feature of this broad aspect, the means for preventing displacement of the coupling comprises a reinforcement/reinforced section for reinforcing the coupling, wherein the reinforcement, defines a portion of the sheath.

As example of this feature, the reinforcement/reinforced section is defined by/comprises a proximal reinforcement/reinforced section that is positioned behind the coupling to prevent displacement of the coupling upon actuation of the pull wires.

As a further example of this feature, the reinforcement/reinforced section is defined by/comprises an encapsulating reinforcement/reinforced section that is positioned around/over the coupling to help prevent proximal displacement and rotational displacement of the coupling.

In one instance of this example, the encapsulating reinforcement/reinforced section is formed integrally with the proximal reinforcement/reinforced section.

In some embodiments of the present invention, the reinforcement/reinforced section enables an angle between the pull wire and the coupling to be maintained substantially at about <NUM> degrees during actuation.

As an example of this feature, the reinforcement/reinforced section is defined by/comprises an encapsulating reinforcement /reinforced section that is positioned around/over the coupling to help prevent proximal displacement and rotational displacement of the coupling.

In the invention, the coupling comprises a pull-ring.

In the invention, reinforcement/reinforced section is defined by/ comprises at least two pull ring anchor holes for coupling the pull ring to the sheath.

In another example, the reinforcement/reinforced section comprises an integrated pull-ring that is coupled to one or more components of the sheath to minimize displacement by providing a longer fulcrum requiring greater force to displace the pull-ring.

In a specific instance of this example, the integrated pull-ring comprises a pull-ring that is coupled to a marker band.

As another example of this feature, the reinforcement comprises at least two connections/points of contact for connecting the coupling to the sheath.

As still another example of this feature, the reinforcement/reinforced section comprises an integrated coupling that is connected to one or more components of the sheath to minimize displacement by providing a longer fulcrum requiring greater force to displace the coupling.

In one such example, the integrated coupling comprises a coupling that is connected to a marker band.

As still another example of this feature, the reinforcement/reinforced section comprises a polymer under layer, to enable the coupling to be captured substantially between the polymer under layer and a polymer over layer defining a portion of the shaft to be surrounded thereby.

In a further broad aspect, embodiments of the present invention comprise a reinforced steerable sheath assembly that is usable with an actuator comprising, a shaft section defining a sheath that is operable to be deflected, and one or more pull wires that are coupled to the sheath via a coupling at a point of contact between the pull wires and the sheath. The pull wires being operable to be coupled to the actuator for actuating the pull wires. The reinforced steerable sheath assembly further comprises a reinforcement/reinforced section for reinforcing the coupling, the reinforcement/reinforced section defining a portion of the sheath, wherein the reinforcement/reinforced section prevents displacement of the coupling to help minimize failure at the coupling upon actuation of the actuator to actuate the pull wires to deflect the sheath.

In a further broad aspect, embodiments of the present invention comprise a reinforced steerable sheath assembly that is usable with an actuator comprising, a shaft section defining a sheath that is operable to be deflected. The shaft section has a proximal end and a distal end and the actuator is positioned proximate the proximal end of the shaft section. The reinforced steerable sheath assembly further comprises a coupling attached proximate the distal end of the shaft section, and one or more pull wires. A distal end of the pull wires are coupled proximate the distal end of the shaft section via the coupling, and the proximal end of the pull wires being coupled to the actuator for actuating the pull wires. The reinforced steerable sheath assembly further comprises a means for preventing displacement of the coupling positioned proximate to the coupling, whereby said means helps to minimize failure of the coupling at a point of contact between the pull wires and the coupling, and at a point of contact between the coupling and the sheath, upon actuation of the pull wires to deflect the sheath.

As a feature to this broad aspect, the means for preventing displacement of the coupling comprises a reinforced section for reinforcing the coupling.

As example of this feature, the reinforced section comprises a proximal reinforcement member positioned proximal to the coupling to prevent displacement of the coupling upon actuation of the pull wires.

In one such example, the reinforcement member supports the coupling to prevent displacement.

As a further example of this feature, the reinforced section comprises an encapsulating member that is positioned over the coupling to prevent proximal displacement and rotational displacement of the coupling upon actuation of the pull wires.

In one such example, the reinforced section further comprises a proximal reinforcement member positioned proximal to the coupling.

As a further example of the feature, the the encapsulating member is integral with the proximal reinforcement member.

The reinforced section comprises at least two pull ring anchor holes for coupling the pull ring to the shaft section.

Another example of this feature, the reinforced section comprises an integrated pull-ring that is coupled to one or more components of the sheath to minimize displacement by providing a longer fulcrum requiring greater force to displace the pull-ring.

In a specific instance, the integrated pull-ring comprises the pull-ring coupled to a marker band.

As a feature to this broad aspect, the reinforced section comprises at least two points of contact for connecting the coupling to the shaft section.

As another feature to the broad aspect, the reinforced section comprises an integrated coupling that is connected to one or more components of the sheath to minimize displacement by providing a longer fulcrum requiring greater force to displace the coupling.

As a further example of this feature, the integrated coupling comprises the coupling connected to a marker band.

As another feature of the broad aspect, the reinforced section comprises a polymer under layer, to enable the coupling to be captured substantially between the polymer under layer and a polymer over layer defining a portion of the shaft to be surrounded thereby.

As an example of any one of the examples described herein above, the reinforced steerable sheath further comprising a locking member, wherein the at least one pull wire is attached at the distal end of the at least one pull wire to the locking member. The locking member is dimensioned to fixably couple to a corresponding aperture on the coupling, whereby when the locking member and aperture are coupled, the pull wires are fixed relative to the coupling.

In a specific instance, the locking member comprises a rectangular member and the aperture is a rectangular slot.

As an example of any one of the examples described herein above, the reinforced section is a substantially rigid polymer.

In a specific instance, the substantially rigid polymer comprises 72D Pebax or Nylon <NUM>.

In some embodiment of the present invention, the reinforced section substantially maintains an angle between the pull wire and the coupling to be about <NUM> degrees during actuation.

In some embodiment of the present invention, the section substantially proximal to the coupling is straight.

In a further broad aspect, a reinforced steerable sheath assembly comprising, a shaft section defining a sheath that is operable to be deflected, the shaft section having a proximal end and a distal end, and an actuator positioned proximate the proximal end of the shaft section. The reinforced steerable sheath assembly further comprises a coupling attached proximate the distal end of the shaft section, and one or more pull wires. A distal end of the pull wires are coupled proximate the distal end of the shaft section via the coupling and wherein a proximal end of the pull wires are coupled to the actuator. The steerable sheath assembly further comprises a reinforced section positioned proximate to the coupling, wherein the reinforced section prevents displacement of the coupling upon actuation of the pull wires to deflect the sheath.

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. In one embodiment of the present invention, as shown in <FIG>, a reinforced steerable sheath assembly <NUM> is provided that is usable with an actuator. The reinforced steerable sheath assembly <NUM> comprises a shaft section <NUM> that defines a sheath <NUM> that is operable to be deflected. The reinforced steerable sheath assembly <NUM> further comprises one or more pull wires <NUM>, <NUM> that are coupled to the sheath <NUM> via a coupling <NUM> at a point of contact between the pull wires <NUM>, <NUM> and the sheath <NUM>.

The pull wires <NUM>, <NUM> are operable to be coupled to an actuator for actuating the pull wires <NUM>, <NUM>. The reinforced steerable sheath assembly <NUM> additionally comprises a means <NUM> for preventing displacement of the coupling <NUM>. In some such embodiments, the means <NUM> for preventing displacement of the coupling comprises a reinforcement /reinforced section <NUM> for reinforcing the coupling <NUM> [for example by reinforcing an area of the shaft <NUM> around the coupling <NUM>], wherein the reinforcement/ reinforced section <NUM> defines a portion of the sheath <NUM>. In the example shown, the means <NUM> for preventing displacement (a reinforcement /reinforced section <NUM>) helps to minimize failure at the coupling <NUM> at the point of contact between the pull wires <NUM>, <NUM> and the sheath <NUM> (or in other words a portion of the shaft <NUM> of the sheath <NUM>) upon actuation of the pull wires upon actuation of the actuator to deflect the sheath.

In accordance with the embodiment as shown in <FIG>, the means for preventing displacement of the coupling, such as a reinforcement/reinforced section <NUM> prevents both proximal displacement of the coupling <NUM> [such as a pull-ring <NUM>] as well as rotational displacement or pivoting of the coupling [such as the pull-ring <NUM>]. The proximal displacement and rotational displacement or pivoting is shown with respect to <FIG> and <FIG> showing embodiments of the present invention, for illustrative purposes only. Proximal displacement occurs when the coupling <NUM> displaces proximally towards the proximal end of the shaft, and in some cases, the displaced coupling interferes with or is positioned proximally to the deflectable section of the sheath <NUM>. This typically results from failure of the means for attaching the coupling <NUM> to the shaft, which is illustrated at item <NUM> in <FIG>. Rotational displacement occurs when the coupling <NUM> pivots and experiences rotational displacement around an axis (for example, where the coupling <NUM> is fixed using a single anchor point, coupling <NUM> rotationally displaces about the axis created by that anchor point) and the angle between the coupling <NUM> and the pull wire <NUM>, <NUM> is no longer maintained at <NUM> degrees. The curvature at the joint between the coupling <NUM> and the pull wire <NUM>, <NUM> may result in breaking of the joint as illustrated at item <NUM> in <FIG>. Failure may result from a combination of both rotational and proximal displacement.

In some embodiments of the present invention, the reinforcement/reinforced section enables the angle between the pull wire and the coupling <NUM> to be maintained substantially at about <NUM> degrees during actuation.

With reference again to <FIG> as well in <FIG> and <FIG>, in one embodiment of the present invention, the reinforcement/reinforced section <NUM> is defined by/comprises a proximal reinforcement member such as proximal reinforcement/reinforced section <NUM> that is positioned behind the coupling <NUM> [such as the pull ring <NUM>] to prevent displacement of the coupling <NUM> upon actuation of the pull wires <NUM>, <NUM>. The proximal reinforcing/reinforced section <NUM> in some examples comprises a substantially rigid section, for example comprising polymer, such as portion of Nylon <NUM>. In some such examples, of steerable sheath assembly of the present invention, the coupling <NUM> is positioned distal to the bendable or deflectable portion of the shaft, which in some examples comprises a 35D durometer section of Pebax polymer. As such, the proximal reinforcing/ reinforced section <NUM> functions as a stop to prevent rotation of the coupling <NUM> [such as pull-ring <NUM>], and additionally can help prevent the coupling <NUM> [such as pull-ring <NUM>], from slipping proximally and/or behind the deflectable section <NUM> of the sheath <NUM> [which is now proximal to the reinforcing/ reinforced section <NUM>]. In some examples the proximal reinforcement/reinforced or reinforcing section <NUM> may also capture a distal end of a braid of the shaft <NUM> to capture the frayed edges therein. <FIG> is a cross section of the specific embodiment of a reinforced sheath <NUM> seen in <FIG> along the cut-line BM. The specific embodiment has two pull wire lumens <NUM>, <NUM> secured under layer <NUM> (e.g., a braided wire). The pull wires <NUM>, <NUM> run through the pull wire lumens <NUM>, <NUM> along the length of the shaft <NUM>.

In some embodiments of the present invention, with reference again to <FIG>, <FIG> and <FIG>, the reinforcement/reinforced section <NUM> is defined by or comprises an encapsulating member such as an encapsulating reinforcement/reinforced section <NUM> that is positioned around/over the coupling <NUM> [such as pull-rings <NUM>] to help prevent proximal displacement and rotational displacement of the coupling. The reinforcement/reinforced section <NUM> functions to cap and/or grip the coupling <NUM> [such as pull-rings <NUM>] to substantially minimize the movement or displacement of the pull-ring under deflection of the pull-wires. In some such embodiments, the encapsulating reinforcement/reinforced section <NUM> additionally encapsulates a marker band <NUM> that is positioned distal to the pull-ring <NUM>.

In some such examples, both encapsulating reinforcement/reinforced section <NUM> and the proximal reinforcement/reinforced section <NUM> together help to encapsulate the coupling <NUM> [such as pull-ring <NUM>] and keep it straight to mitigate against failure at the pull wire/pull-ring interface. The reinforcement at the joint which may be a weld joint may help prevent fatigue. In the embodiment, described herein, the proximal and encapsulating reinforcements/reinforcement sections <NUM>, <NUM> may comprise a substantially rigid polymer. In some such examples, the substantially rigid polymer comprises a 72D Pebax. In other examples, the substantially rigid polymer comprises Nylon <NUM>.

In a specific example the encapsulating reinforcement/reinforced section <NUM> is formed integrally with the proximal reinforcement/reinforced section <NUM>. In some such examples, both encapsulating and proximal reinforcement/reinforced sections <NUM>, <NUM> comprise Nylon <NUM>.

In some such embodiments, encapsulating reinforcement/ reinforced section <NUM> provided overtop the coupling <NUM> [such as pull-ring <NUM>] functions grip the pull-ring <NUM> to prevent movement thereof and the proximal reinforcement/ reinforced section <NUM> that is the section that is behind the pull ring <NUM> stops the movement of the pull-ring <NUM> because of stiffness of the material the defines the proximal reinforcement/reinforced section <NUM> such as Nylon <NUM>.

As the pull wires are actuated, the proximal reinforcement /reinforced section <NUM> behind the pull-ring <NUM> remains substantially straight as the sheath <NUM> bends. Both the encapsulating reinforcement /reinforced section <NUM> and proximal reinforcement/reinforced section <NUM>, keep the coupling <NUM> [such as pull-wire <NUM>] substantially straight such that the angle the pull ring <NUM> sees (i.e. the angle between the pull-ring <NUM> and the pull wires <NUM>, <NUM>) is substantially maintained at <NUM> degrees. As such, the one or more pull wires <NUM>, <NUM> stay at a <NUM> degree position to the pull ring <NUM>. By helping to keep the pull-ring <NUM> straight the reinforced section <NUM> of the sheath (as defined by Both the encapsulating reinforcement/ reinforced section <NUM> and proximal reinforcement/reinforced section <NUM>) help mitigate against failure at the pull wire <NUM>, <NUM>/pull-ring <NUM> interface or joint (such as a weld-joint) and may help prevent fatigue. As the sheath <NUM> is deflected, the section of the shaft <NUM> of the sheath <NUM> substantially behind or proximal to weld point it is straight, and does not become part of curve.

As the shaft <NUM> immediately proximal to the coupling <NUM> [pull-ring <NUM>] stays substantially rigid or stiff, keeping the shaft section [and thus the pull wire <NUM>, <NUM>] substantially straight, substantially maintaining the <NUM> degree angle between the pull-wires <NUM>, <NUM> and the pull-ring <NUM>.

In some embodiments, encapsulating reinforcement/ reinforced section <NUM> overtop the pull ring <NUM>, help to prevent it from displacing, and the straight section that is defined by the encapsulating reinforcement/ reinforced section <NUM> (such as nylon <NUM> section) helps to maintain the angle at the joint between the pull ring <NUM> and the pull wire <NUM>, <NUM> by keeping the shaft section <NUM> immediately proximal to the pull-ring <NUM> straight so that the pull wires <NUM>, <NUM> can remain straight along that section maintaining an angle of about <NUM> degrees between the pull wire <NUM>, <NUM> and the pull-ring <NUM>. The proximal and encapsulating reinforcements/ reinforcing sections <NUM>, <NUM> also help displacement of the pull-ring either rotational displacement or proximal displacement.

The reinforced steerable sheath, where the reinforcement/reinforced section enables an angle between the pull wire and the coupling to be maintained substantially at about <NUM> degrees during actuation.

In some embodiments of the present invention, the steerable sheath assembly may be provided with a reinforcement/reinforced section that comprises one or more of the alternative reinforcement/reinforced section as provided in the present disclosure.

In an alternate embodiment of the present invention, as shown in <FIG>, a reinforcement/reinforced section <NUM> is provided that is defined by/comprises a reinforcement under layer <NUM> that is provided under the pull-ring <NUM>. Under layer <NUM> may be a polymer under layer to enable the coupling <NUM> [such as pull-ring <NUM>] to be captured substantially between the reinforcement under layer <NUM> and a polymer over layer, and as such the pull-ring <NUM> is encapsulated and supported by the surrounding structures. In some instances the section of the shaft over the pull-ring is the encapsulating reinforcement/ reinforced section <NUM>, as additionally shown in <FIG>. In some such embodiments, the pull-ring <NUM> is embedded or captured and supported within the polymer layers of the shaft at the coupling. As shown in <FIG>, the encapsulating reinforcement/ reinforced section <NUM> increases the stiffness of the outer layer over the rings. In some such examples, the encapsulating reinforcement/ reinforced section <NUM> comprises 72D Pebax layer. In other examples the reinforced section <NUM> comprises Nylon <NUM>.

In an alternate embodiment of the present invention, as shown in <FIG>, a reinforced steerable sheath <NUM> is provided. In this embodiment, the reinforcement/reinforced section <NUM> comprises an integrated coupling <NUM> where the coupling <NUM> [such as pull-ring <NUM>] is connected to one or more components of the sheath <NUM> to minimize displacement of the coupling <NUM> [such as pull-ring <NUM>]. In some embodiments, the integrated coupling <NUM> results in a longer fulcrum (relative to a coupling <NUM> alone) by lengthening the area of contact between the sheath and the coupling <NUM>/integrated coupling <NUM>. By providing a longer fulcrum, greater force is required to displace the coupling <NUM> as more support is provided by the layers of the sheath. In one particular example, the pull ring <NUM> is welded to the marker band <NUM> as shown in <FIG>. In some examples, the pull ring <NUM> may be welded to the marker band <NUM> along one or more points to form one or more welds. As such in some instances, the integrated coupling <NUM> comprises a coupling <NUM> that is connected to a marker band <NUM>.

In some embodiments, the dimensions of the coupling <NUM> may be modified to achieve a longer fulcrum. For example, the body of the coupling <NUM> may be lengthened resulting in a greater area of contact between coupling <NUM> and layers of the sheath.

In the present invention, a reinforced steerable sheath <NUM> is provided as shown in <FIG>, wherein the reinforcement/reinforced section <NUM> comprises at least two connections/points of contact for connecting the coupling <NUM> [such as pull -ring] to the sheath. In one specific example, the at least two connections/points of contact are at least two pull ring anchor holes <NUM> for coupling the pull ring to the sheath. Once the pull ring <NUM> is coupled to a section of the shaft <NUM> of the sheath <NUM>, the polymer around the pull ring flows through the pull ring anchor holes <NUM> to form pegs. In some such instances, the pull ring anchor holes <NUM> (and thus pegs) may be spaced apart from the midpoint between the pull-wires. In some such examples, the pull ring anchor holes <NUM> (and thus pegs) are positioned so that they are not too close to the pull wires so they do not see too much pulling from the pull-wires. Alternate exemplary embodiments of pull-ring anchor hole patterns can be seen in <FIG> and <FIG>. By providing more than one pull ring anchor hole and (thus more than one peg), more than one anchoring point is provided between the coupling and the pull ring <NUM> which may prevent rotation of the pull-ring. By additionally spacing the pegs, the pivoting may be reduced as any force experienced by the pull ring is applied at two or more points instead of one. Spacing the more than one pull ring anchor holes (and thus more than one pegs) additionally distributes the points at which force is applied. Thus, the rotational force is distributed to multiple parts of the pull ring.

The plurality of holes prevent rotation about a point and are provided towards the periphery to minimize rotation. In the invention, two holes are provided that are off centered but are not in line with pull wires. The holes may be one or two smaller holes vs a larger hole. The smaller holes may be provided further away from the wires and may be less inclined to impact the integrity of the weld between the pull wires and the pull ring.

In an alternate embodiment of the present invention, a coupling <NUM> (such as a pull-ring <NUM>) is provided as seen in <FIG> and <FIG>, wherein the coupling <NUM> comprises a slot <NUM> for receiving a locking member <NUM>. Locking member <NUM> may be integral with pull wires <NUM>, <NUM> or may be attached thereto. Welding or other attachment means (adhesives, etc.) may be used to attach the pull wires <NUM>, <NUM> to the locking member <NUM>. In one example, the pull-ring <NUM> has a slot <NUM> between the pull-ring <NUM> and pull wires <NUM>, <NUM>. By attaching the pull wires <NUM>, <NUM> to the pull ring <NUM> using the slot <NUM> and locking member <NUM>,force which is applied to the pull wires <NUM>, <NUM> may be distributed throughout the engagement surfaces between the locking member <NUM> and slot <NUM>. This in turn reduces the likelihood that the joint between the pull-ring <NUM> and the pull wires <NUM>, <NUM> will break. In the embodiment depicted in <FIG> and <FIG>, the locking member <NUM> is a rectangular member <NUM> which is attached to pull wires <NUM>, <NUM> via a series of attachment points using various attachment means (such as welds <NUM>). Pull ring <NUM> comprises a slot <NUM> which has a corresponding shape adapted to receive the locking member <NUM>. Those skilled in the art will appreciate that slots and locking members of varying dimensions may be used. During assembly, slot <NUM> of the pull ring <NUM> receives the locking member <NUM> and attachment means are used to secure the locking member <NUM> to the pull ring <NUM>. Various attachment means are known in the art, such as welding, adhesives, and fasteners.

In one broad aspect, embodiments of the present invention comprise a reinforced steerable sheath assembly that is usable with an actuator comprising: a shaft section defining a sheath that is operable to be deflected, and one or more pull wires that are coupled to the sheath via a coupling at a point of contact between the pull wires and the sheath. The pull wires are operable to be coupled to the actuator for actuating the pull wires. The reinforced steerable sheath assembly further comprises a means for preventing displacement of the coupling, wherein the means for preventing displacement to minimize failure at the coupling at the point of contact between the pull wires and the sheath upon actuation of the pull wires upon actuation of the actuator to deflect the sheath.

The embodiment(s) 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 reinforced steerable sheath assembly (<NUM>) that is usable with an actuator comprising:
a shaft section defining a sheath (<NUM>) that is operable to be deflected, the shaft section having a proximal end and a distal end, the actuator being positioned proximate the proximal end of the shaft section;
a coupling (<NUM>) attached proximate the distal end of the shaft section;
one or more pull wires (<NUM>, <NUM>), wherein a distal end of each pull wire is coupled proximate the distal end of the shaft section via the coupling (<NUM>), a proximal end of each pull wire being coupled to the actuator for actuating each pull wire (<NUM>, <NUM>); and
means for preventing displacement of the coupling (<NUM>) positioned proximate to the coupling (<NUM>) comprising a reinforced section for reinforcing the coupling, whereby said means helps to minimize failure of the coupling (<NUM>) at a point of contact between the pull wires (<NUM>, <NUM>) and the coupling (<NUM>), and at a point of contact between the coupling (<NUM>) and the sheath (<NUM>), upon actuation of the pull wires (<NUM>, <NUM>) to deflect the sheath (<NUM>), wherein the coupling (<NUM>) comprises a pull-ring (<NUM>), and the reinforced section comprises at least two pull ring anchor holes (<NUM>) for coupling the pull-ring (<NUM>) to the shaft section, the at least two pull-ring anchor holes (<NUM>) being off centered and not in line with the one or more pull wires (<NUM>, <NUM>).