Patent Description:
Delivery devices including, among other components, catheters and delivery cables are used for an ever-growing number of procedures, and in particular, for the delivery of medical devices to a target site. Typically, the catheter is manipulated through the patient's vasculature and to the intended site, for example, a site within the patient's heart or other organ and the delivery cable is used to advance the medical device through the catheter and to the target site. Once the medical device has reached the target site, the delivery cable may be detached or uncoupled from the medical device such that the medical device is deployed from both the catheter and the delivery cable.

Generally, the catheter would have an overall outside diameter small enough to negotiate blood vessels or other anatomy while retaining an inner diameter ("bore size") large enough to accommodate the medical device (and delivery cable) therethrough. Since the path within the patient may be long, tortuous, and/or involve intricate placement of a medical device(s), maneuverability via steering the catheter may be particularly beneficial. Furthermore, the delivery cable must be rigid enough so as to be capable of maneuvering the medical device through the catheter while still being flexible enough to accommodate the tortuous path through which it must travel to the target site.

<CIT> discloses an assembly for positioning an embolization coil in the vascular system. The assembly comprises a delivery wire having a central core with a blade-shaped portion which extends inside a threading coil and has a blade thickness of preferably less than <NUM>% of the blade width. The threading coil is fixed to the central core at least at the edges of the blade-shaped portion.

<CIT> relates to a medical surgical device and specifically a wire guide for percutaneous placement within a body cavity. The wire guide includes a multi-filar coil having an increasing pitch towards the distal end of the wire guide. Methods of using the device are also disclosed. <CIT> discloses a pusher-vasoocclusive coil assembly that is advanced through a catheter to a site within a vessel and is manipulated to detach the coil from the assembly. The pusher has a distal end that is initially threaded into the proximal end of the coil and the assembly includes a sleeve that is slid over the pusher and whose distal edge abuts the proximal end of the coil to hold the coil in place while the distal end of the pusher is threaded out of the coil to detach the coil at the site.

The foregoing and other aspects, features, details, utilities, and advantages of the present disclosure will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.

Septal occluders or other collapsible medical devices may be delivered through a catheter or delivery sheath and to a target site using a relatively stiff delivery cable. The stiffness of the delivery cable provides the column strength required to push the occluder through the catheter. However, the stiffness of the cable may also tend to pull and/or bias the occluder after deployment and prior to release of the occluder from the delivery cable, creating unpredictability in the occluder's final position. Further, although at least some delivery cables include a flexible distal section, the flexible distal section may cause the delivery cable to "snake," or curve, during advancement through the delivery sheath, which may result in an increase in the force required to advance the septal occluder.

Accordingly, the present disclosure is directed to a delivery cable comprising a rigid proximal portion and a flexible distal portion. The delivery cable is configured so as to have sufficient torque and column strength sufficient to deliver a medical device to a target site while also having sufficient flexibility to navigate through a patient's vasculature and to reduce movement of a medical device upon deployment of the medical device from the delivery cable.

The systems and methods described herein provide a delivery cable that includes a stiff proximal section to provide column strength and a flexible distal section to reduce an amount of bias that the delivery cable places on a medical device being delivered (e.g., a collapsible medical device, such as an occluder). The delivery cable includes a flexible inner member, or core, a more rigid proximal outer member, and a flexible distal outer member surrounding a distal portion of the flexible inner member. The rigid proximal outer member is configured to provide sufficient column strength to assist in delivering the medical device through a catheter or delivery sheath and sufficient torque to assist in removing the medical device from the delivery cable via rotation of the delivery cable, even in tortuous or challenging anatomy.

In contrast, the flexible distal outer member provides increased flexibility to the delivery cable during release of the medical device from the delivery cable upon deployment of the medical device. That is, the increased flexibility of the distal portion of the delivery cable reduces the tendency of the medical device to move, "jump," pull, or bias upon detaching the delivery cable from the medical device, which increases the predictability of the final position of the medical device after deployment thereof.

Further, the distal outer member of the delivery cables described herein have an outer diameter sized so as to reduce "snaking," curving, or bunching of the delivery cable during advancement through the catheter or other delivery sheath. In particular, by increasing the outer diameter of the delivery cable at the distal end thereof (as compared to outer diameter of the flexible inner member alone) such that it approximates the inner diameter of the catheter or delivery sheath through which it is advanced during delivery of a medical device, the ability of the delivery cable to "snake," curve, or bunch within the catheter or delivery sheath is reduced, thus reducing the amount of force necessary to advance the medical device through the catheter or delivery sheath. Further, by configuring the distal outer member to have a relatively short length as compared to the delivery cable overall, the ability of the delivery cable to "snake," curve, or bunch within the catheter or delivery sheath is further reduced.

Referring now to the Figures, <FIG> is a perspective view of a catheter assembly or introducer assembly <NUM> according to one embodiment including a catheter or an introducer <NUM> having a proximal portion <NUM> and a distal portion <NUM>. Introducer <NUM> may be operably connected to a handle assembly <NUM> which assists in guiding or steering the introducer during procedures. Introducer assembly <NUM> further includes a hub <NUM> operably connected to an inner lumen (not shown) within the handle assembly <NUM> for insertion or delivery of catheter assemblies, fluids, or any other devices known to those of ordinary skill in the art. Optionally, introducer assembly <NUM> further includes a valve <NUM> operably connected to hub <NUM>.

<FIG> is a schematic diagram of a portion of introducer <NUM> shown in <FIG> in combination with one embodiment of a delivery cable <NUM> and a medical device <NUM>. As shown in <FIG>, delivery cable <NUM> extends from distal portion <NUM> of introducer <NUM> (i.e., a delivery sheath <NUM> of introducer <NUM>), and is coupled to medical device <NUM>. In this embodiment, medical device <NUM> is a collapsible occluder. Alternatively, medical device <NUM> may be any device capable of being coupled to delivery cable <NUM>. <FIG> is a perspective view of the delivery cable <NUM>. As described in detail below, delivery cable <NUM> includes a distal outer member <NUM>, a proximal outer member <NUM>, an inner member <NUM> (not shown in <FIG>), and an endscrew <NUM>.

<FIG> is a longitudinal cross-sectional view of delivery cable <NUM>. Delivery cable <NUM> may be used to facilitate delivering a medical device such as, but not limited to, a collapsible occluder or the like. It should be noted that although delivery cable <NUM> is described herein as being useful in combination with introducer <NUM> illustrated in <FIG> and <FIG>, delivery cable <NUM> may be used in the delivery process of many various medical devices and in combination with many various sheaths, loaders, valves, etc..

As shown in <FIG>, delivery cable <NUM> includes a flexible inner member (also referred to herein as a flexible core) <NUM>. Delivery cable <NUM> has a distal section <NUM> and a proximal section <NUM>. At least a portion of inner member <NUM> is surrounded by a distal outer member or coil <NUM> at distal section <NUM>, and at least a portion of inner member 202is surrounded by a proximal outer member or coil <NUM> at proximal section <NUM>. An endscrew <NUM> is coupled to a distal end of inner member <NUM> to facilitate selectively attaching and detaching a medical device to delivery cable <NUM>. For example, endscrew <NUM> may include a threaded portion configured to cooperate with a corresponding threaded portion positioned on or within the medical device to be delivered such that the medical device may be engaged or disengaged (i.e., coupled to or released from) delivery cable <NUM> upon rotation of delivery cable <NUM>, and thus rotation of endscrew <NUM>. Endscrew <NUM> is attached to inner member <NUM> via any method suitable to sufficiently secure endscrew <NUM> to inner member <NUM>. For example, suitable methods include, but are not limited to, bonding via an adhesive (such as an epoxy), connecting (e.g., using a coupling member, such as a stainless steel tube or platinum-iridium marker band that is dome welded to a distal end of inner member <NUM> prior to being crimp or spot welded to endscrew <NUM>), soldering, welding, spot welding or crimp welding, clamping, swaging, crimping, or any combination thereof. Endscrew <NUM> and inner member <NUM> may also be integrally formed (e.g., an overmolded screw). Further, in other embodiments, as an alternative to endscrew <NUM>, any suitable device for attaching and detaching a medical device may be used.

Inner member <NUM> is formed of any material and has any configuration suitable to provide both torque strength and flexibility to delivery cable <NUM> and enables delivery cable <NUM> to function or operate as described herein. For example, inner member <NUM> may be configured so as to optimize torque strength and/or flexibility by modifying a length of inner member <NUM>, a diameter or number of wires that may form inner member <NUM>, a number of layers forming inner member <NUM>, and/or the winding direction for each such layer.

For example, in one embodiment, inner member <NUM> is a multi-filar nitinol or stainless steel core that has a 1x7+<NUM> construction. In this embodiment, as illustrated in <FIG> and discussed in more detail below, inner member <NUM> includes two outer layers formed using right-hand wound nitinol wires, and has an outer diameter of approximately. <NUM> inches (<NUM> millimeters (mm)). In other embodiments, inner member <NUM> may have an outer diameter from. <NUM> inches (<NUM>) to. <NUM> inches (<NUM>), including but not limited to about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), and about. <NUM> inches (<NUM>).

The orientation of the outer two layers of nitinol wires of inner member <NUM> (i.e., both right-hand wound), aides in providing maximum torque strength during release or disengagement of a medical device from delivery cable <NUM> during deployment thereof (and an increased flexibility and torque strength as compared to as least some other known delivery cables). In an alternative embodiment, the outer two layers may be oriented in opposite directions (i.e., one right-hand wound and one left-hand wound) so as to create a bi-directional torque. Further, in some embodiments, inner member <NUM> may include a tapered configuration so as to provide a transition from a more rigid proximal portion to a more flexible distal portion. In such embodiments, the outer diameter of inner member <NUM> could range from <NUM> inches to <NUM> inches (<NUM> to <NUM>) depending on the desired flexibility and torque strength.

As noted above, proximal outer member <NUM> surrounds inner member <NUM> at a proximal section <NUM> thereof. Inner member <NUM> extends through any length of proximal outer member <NUM> sufficient to enable the coupling or attaching of inner member <NUM> to proximal outer member <NUM>. For example, as shown in <FIG>, inner member <NUM> may only extend through a portion of the length of proximal outer member <NUM>, wherein the section of overlap between inner member <NUM> and proximal outer member <NUM> (i.e., the length of delivery cable <NUM> along which inner member <NUM> extends through proximal outer member <NUM>) is sufficient to enable the coupling thereof. In other embodiments, however, inner member <NUM> may extend through an entire length of proximal outer member <NUM>. Still in other embodiments, inner member may include a proximal portion extending through proximal section <NUM> and a separate distal portion extending through distal section <NUM>, as is further illustrated with respect to <FIG> and further described below. In this particular embodiment, the outer diameter and overall configuration of inner member <NUM> at proximal section <NUM> may be the same or different than the outer diameter and overall configuration of inner member <NUM> at distal section <NUM>.

Proximal outer member <NUM> may be coupled or attached to inner member <NUM> by any suitable means. For example, in one embodiment, proximal outer member <NUM> is adhesively attached to inner member <NUM> via an epoxy placed along the entire overlapping surface of proximal outer member <NUM> or on only a portion thereof. In other embodiments, proximal outer member <NUM> is attached or coupled to inner member <NUM> by soldering, welding, spot or crimp welding, clamping, swaging, crimping, with any suitable adhesive, or any combination thereof.

Proximal outer member <NUM> is also coupled at a distal end thereof to a proximal end of distal outer member <NUM> by any suitable means. In one embodiment, proximal outer member <NUM> and distal outer member <NUM> are adhesively attached or coupled to one another via an epoxy. In other embodiments, proximal outer member <NUM> is attached or coupled to distal outer member <NUM> by welding, clamping, or with any suitable adhesive. Further, in some embodiments, a transition segment (not shown in <FIG>) is positioned at an interface between distal outer member <NUM> and proximal outer member <NUM> to provide intermediate flexibility therebetween.

Proximal outer member <NUM> is sized and configured so as to provide sufficient column strength to delivery cable <NUM> to assist in delivering the medical device through a catheter or delivery sheath and sufficient torque to assist in releasing or disengaging the medical device from the delivery cable, even in tortuous or challenging anatomy. In one embodiment, proximal outer member <NUM> is a relatively stiff multi-filar cable formed of eight <NUM> inch (<NUM>) stainless steel wires wound with an outer diameter of approximately. <NUM> inches (<NUM>) and an inner diameter of approximately <NUM> inches (<NUM>). In other embodiments, proximal outer member <NUM> may have an outer diameter from. <NUM> inches (<NUM>) to. <NUM> inches (<NUM>), including but not limited to about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), about. <NUM> inches (<NUM>), and about. <NUM> inches (<NUM>). Proximal outer member <NUM> may be formed of any number of wires, having any size and shape, and arranged in any configuration suitable to provide the desired flexibility and strength of proximal outer member <NUM>.

As illustrated in <FIG>, distal outer member <NUM> surrounds inner member <NUM> and extends between proximal outer member <NUM> and endscrew <NUM>. As described above, distal outer member <NUM> is attached or coupled to proximal outer member <NUM> by any suitable means. Distal outer member <NUM> is sized and configured so as to provide sufficient flexibility to delivery cable <NUM> to prevent the tendency of the medical device being delivered via delivery cable <NUM> to move, "jump," pull, or bias upon detaching the medical device from delivery cable <NUM> and to prevent undesired straightening of a delivery sheath during delivery of a medical device. Distal outer member <NUM> is further sized and configured so as to reduce the ability or tendency of delivery cable, and in particular a distal portion thereof, to "snake," curve, or bunch within the catheter or delivery sheath. In particular, distal outer member <NUM> has an outer diameter (e.g., <NUM> inches (<NUM>) or <NUM> inches (<NUM>)) that is slightly smaller than an inner diameter of a catheter or delivery sheath through which delivery cable <NUM> is advanced during delivery of a medical device. For example, distal outer member <NUM> may have an outer diameter that is greater than <NUM>% of the inner diameter of the catheter or delivery sheath, including greater than <NUM>%, greater than <NUM>%, greater than <NUM>%, and greater than <NUM>% of the inner diameter of the catheter or delivery sheath, more particularly, an outer diameter that is greater than <NUM>% of the inner diameter of the catheter or delivery sheath, and even more particularly, an outer diameter that is greater than <NUM>% of the inner diameter of the delivery sheath. These percentages are exemplary. For example, those of skill in the art will appreciate that, for larger sheath diameters, different percentages may be more suitable. By keeping the space between the catheter or delivery sheath and the outer surface of distal outer member <NUM> minimized, the ability of distal outer member <NUM> to "snake," bunch, or curve within a catheter or delivery sheath during advancement of delivery cable <NUM> therethrough is reduced, which in turn, reduces the amount of force required to advance a medical device through the catheter or delivery sheath.

The ability or tendency of distal outer member <NUM> to "snake," curve, or bunch within a catheter or delivery sheath is further reduced by configuring distal outer member <NUM> to have a relatively short length as compared to the length of delivery cable <NUM> overall. For example, in one embodiment, distal outer member <NUM> has a length of approximately <NUM> inch (<NUM>). In other embodiments, distal outer member <NUM> may have a length of from <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including from <NUM> inches (<NUM>) to <NUM> inches (<NUM>), from <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including but not limited to about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), and about <NUM> inches (<NUM>).

In one specific embodiment, distal outer member <NUM> has an outer diameter of approximately <NUM> inches (<NUM>). In other embodiments, distal outer member <NUM> may have an outer diameter from <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including but not limited to about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), and about <NUM> inches (<NUM>).

In one embodiment, distal outer member <NUM> includes tightly wound stainless steel wire having a diameter of from <NUM> inches (<NUM>) to <NUM> inches (<NUM>) forming a coil having an outer diameter of from. <NUM> inches (<NUM>) to. <NUM> inches (<NUM>) and a length of from <NUM> inches (<NUM>) to <NUM> inch (<NUM>). In one specific embodiment, distal outer member <NUM> includes tightly wound stainless steel wire having a diameter of approximately. <NUM> inches (<NUM>) forming a coil having an outer diameter of approximately. <NUM> inches (<NUM>) and a length of approximately <NUM> inch (<NUM>). In another specific embodiment, distal outer member <NUM> includes tightly wound stainless steel wire having a diameter of approximately. <NUM> inches (<NUM>) forming a coil having an outer diameter of approximately. <NUM> inches (<NUM>) and a length of approximately <NUM> inch (<NUM>). Accordingly, distal outer member <NUM>, in one embodiment, may have a larger outer diameter than proximal outer member <NUM>. In such an embodiment, a connector may optionally be positioned between a distal end of proximal outer member <NUM> and a proximal end of distal outer member <NUM> so as to provide a smooth transition between the differing outer diameters. In other embodiments, distal outer member <NUM> and proximal outer member <NUM> may have substantially equal outer diameters. As will be understood by those of skill in the art, the pitch, diameter, and/or material of distal outer member <NUM> may be modified without departing from the scope of the disclosure. For example, distal outer member <NUM> may be nitinol in some embodiments.

<FIG> is a longitudinal cross-sectional view of delivery cable <NUM> illustrating a material that may be positioned over at least a portion of proximal outer member <NUM> to reduce the amount of air ingress during advancement of the medical device through a catheter or other delivery device. In one embodiment, at least a portion of the outer surface of proximal outer member <NUM>, and in some embodiments an entire outer surface of proximal outer member <NUM>, is coated, sealed, or surrounded by a heat shrink material suitable to reduce or prevent air ingress during advancement of the medical device during delivery thereof. The heat shrink material may also extend along a portion of distal outer member <NUM>, which may increase the securement between proximal outer member <NUM> and distal outer member <NUM> and may also increase the lubriciousness of delivery cable <NUM> thus aiding in a smoother advancement of delivery cable <NUM> through a patient's vasculature. For example, as shown in <FIG>, a heat shrink material <NUM> circumscribes at least a portion of both proximal outer member <NUM> and distal outer member <NUM>. In other embodiments, heat shrink material <NUM> may circumscribe at least a portion of proximal outer member <NUM>, including a proximal-most end thereof, but not circumscribe distal outer member <NUM>. In yet another embodiment, heat shrink material <NUM> may circumscribe a distal end of proximal outer member <NUM> and a proximal end of distal outer member <NUM>, but not circumscribe the proximal-most end of proximal outer member <NUM>. Heat shrink material <NUM> may be formed of any heat shrink material suitable to reduce or prevent air ingress during advancement of the medical device during delivery thereof, to increase the securement between proximal outer member <NUM> and distal outer member <NUM>, and/or to increase the lubricious of delivery cable <NUM> while not significantly increasing the outer diameter of delivery cable <NUM>.

Delivery cable <NUM> may also include indicator marks or lines (not shown) on a proximal end thereof to convey the position of delivery cable <NUM> with respect to a delivery sheath or other delivery device to a user. In some embodiments, the indicator marks or lines are pad printed or laser etched on heat shrink material <NUM>. In other embodiments, the indicator marks or lines are laser etched on a portion of proximal outer member <NUM>. In still other embodiments, a colored heat shrink material including the indicator marks or lines, or indicating longitudinal placement by varying colors, may be placed on the outer surface of proximal outer member <NUM> prior to heat shrink material <NUM> being applied to delivery cable <NUM>.

<FIG> is an axial cross-sectional view of flexible inner member <NUM>. In this specific embodiment, inner member <NUM> includes a core layer <NUM>, a first outer layer <NUM> surrounding core layer <NUM>, and a second outer layer <NUM> surrounding first outer layer <NUM>. In the specific embodiment, core layer <NUM> includes a single wire having a diameter of approximately <NUM> inches (<NUM>), first outer layer <NUM> includes six wires each having a diameter of approximately <NUM> inches (<NUM>), and second outer layer <NUM> includes five wires each having a diameter of approximately <NUM> inches (<NUM>). In other embodiments, core layer <NUM> may include a single wire having a diameter from <NUM> inches (<NUM>) inches to <NUM> inches (<NUM>), including but not limited to about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), and about <NUM> inches (<NUM>). Further, first outer layer <NUM> may include any suitable number of wires each having a diameter from <NUM> inches (<NUM>) inches to <NUM> inches (<NUM>), including but not limited to about <NUM> inches (<NUM>) inches, about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), and <NUM> inches (<NUM>). In addition, second outer layer <NUM> may include any suitable number of wires each having a diameter from <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including but not limited to about <NUM> inches (<NUM>) inches, about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), about <NUM> inches (<NUM>), and about <NUM> inches (<NUM>).

Alternatively, inner member <NUM> may include any configuration or size of wires that enables inner member <NUM> to function as described herein. That is, inner member <NUM> may include any configuration that facilitates achieving a balance between flexibility and torque strength as described herein. For example, in one embodiment, core layer <NUM> may be absent from inner member <NUM>. In other embodiments, inner member <NUM> may include a 1x3, 1x7, 1x7+<NUM>, 1x12 or any other similar configuration. Using a wound construction with multiple layers for inner member <NUM> facilitates improving torque strength and flexibility. Further, each layer of inner member <NUM> may be formed from any suitable material known in the art. For example, in one specific embodiment, each wire of second outer layer <NUM> may be formed from stainless steel, or any other suitable, weldable material, while each wire of first outer layer <NUM> and core layer <NUM> may be formed of nitinol. Such a configuration provides an increased weld strength between inner member <NUM> and endscrew <NUM> and/or couplers <NUM> and <NUM>, while maintaining a desired flexibility.

<FIG> is a flow diagram of a method <NUM> for manufacturing a delivery cable, such as delivery cable <NUM> (shown in <FIG>), according to one embodiment. Notably, the steps in method <NUM> may be performed in any suitable order, and are not limited to being performed in the order shown in <FIG>. Further, similar steps of method <NUM> may be used for producing additional embodiments of a delivery cable, such as those illustrated in <FIG> and described in more detail below.

Method <NUM> includes providing <NUM> a flexible inner member, such as flexible core <NUM>. Method <NUM> further includes inserting <NUM> the inner member at least partially into a proximal outer member having a first rigidity, such as proximal outer member <NUM> and coupling <NUM> the inner member to the proximal outer member. Method <NUM> further includes inserting <NUM> the inner member into a distal outer member having a second rigidity, such as distal outer member <NUM>. In this embodiment the inner member extends through an entire length of the distal outer coil so that the inner member can attach to the proximal outer member and an endscrew. Method <NUM> further includes coupling <NUM> the proximal outer member to the distal outer member. This coupling facilitates providing a smooth transition between the proximal outer member and the distal outer member, and may be accomplished, for example, using welding, a heat shrink material, or a coupler, as described herein.

<FIG> is a flow diagram of a method <NUM> for implanting a medical device (e.g., collapsible occluder) at a target site in a subject using a delivery cable and a delivery sheath, such as delivery cable <NUM> and delivery sheath <NUM> (shown in <FIG>), according to one example. Whereas the claims define methods of producing a delivery cable, the disclosed methods of use are provided as examples to aid the reader's understanding of the utility of products that may be obtained by the claimed methods of production. Notably, the steps in method <NUM> may be performed in any suitable order, and are not limited to being performed in the order shown in <FIG>. Method <NUM> includes deploying <NUM> the delivery sheath into the subject. In some embodiments, the medical device is already attached to a distal end of the delivery cable in a "preloaded" configuration. Alternatively, in other embodiments, method <NUM> may optionally include coupling <NUM> the medical device to a distal end of the delivery cable. In the embodiments described herein, delivery cable has a sufficient column strength and tensile strength for delivering and recapturing the medical device. As described above, the delivery cable includes at least a flexible inner core, a proximal outer coil having a first rigidity, and a distal outer coil surrounding at least a portion of a distal section of the flexible inner core and having a second rigidity less than the first rigidity. Method <NUM> further includes advancing <NUM> the delivery cable through the deployed delivery sheath. As described above, the relative dimensions of an outer diameter of the distal outer coil and an inner diameter of the delivery sheath facilitate reducing snaking of the delivery cable within the delivery sheath. Method <NUM> further includes continuing <NUM> to advance the delivery cable until the medical device exits the delivery sheath and reaches the target site. At the target site, the relative rigidity of distal section of the delivery cable with respect to the proximal outer coil facilitates reducing bias placed on the medical device by the delivery cable when the distal outer coil is in a bent configuration, thus reducing moving, "jumping," pulling, or biasing upon detaching the delivery cable from the medical device. Method further includes deploying <NUM> the medical device at the target site by detaching the medical device from the delivery cable.

<FIG> is a longitudinal cross-sectional view of one embodiment of a delivery cable <NUM> including a coupler <NUM> that may be used with the assembly shown in <FIG>. Delivery cable <NUM> includes inner member <NUM>, distal outer member <NUM>, proximal outer member <NUM>, and endscrew <NUM>. In this embodiment, as shown in <FIG>, coupler <NUM> couples distal outer member <NUM> to proximal outer member <NUM>. For example, coupler <NUM> may be attached to distal outer member <NUM> and proximal outer member <NUM> using a seam weld, spot weld, tack weld or crimp weld, and coupler <NUM> may be attached to inner member <NUM> using adhesive, soldering, a spot weld or crimp weld, clamping, crimping, or any combination thereof. Further, coupler <NUM> may be, for example, stainless steel. Alternatively, coupler <NUM> may be attached to distal outer member <NUM>, proximal outer member <NUM>, and/or inner member <NUM> using any suitable techniques (e.g., by using an additional coupling member such as a stainless steel tube or platinum-iridium marker band that is dome welded to a distal end of inner member <NUM> prior to being crimp or spot welded to coupler <NUM>). Coupler <NUM> may be made of any material that enables delivery cable <NUM> to function as described herein, and facilitates a robust connection between distal outer member <NUM>, proximal outer member <NUM>, and inner member <NUM>.

In the embodiment shown in <FIG>, inner member <NUM> extends through the entirety of coupler <NUM>, and into a portion of proximal outer member <NUM>. In contrast, <FIG> is a longitudinal cross-sectional view of another embodiment of a delivery cable <NUM>. In this embodiment, inner member <NUM> extends through only a portion of coupler <NUM>, and does not extend into proximal outer member <NUM>. For example, in the embodiment of <FIG>, inner member <NUM> may have an outer diameter (e.g., on the order of approximately <NUM> to <NUM> thousandths of an inch (<NUM> to <NUM>)) that is too large to be received within proximal outer member <NUM>.

Similarly, <FIG> is a longitudinal cross-sectional view of another embodiment of a delivery cable <NUM> in which an inner member does not extend through the entirety of coupler <NUM>. This particular embodiment includes a distal inner member <NUM> and a separate proximal inner member <NUM>. Distal inner member <NUM> extends into and is secured to a distal portion <NUM> of coupler <NUM>, and proximal inner member <NUM> extends into and is secured to a proximal portion <NUM> of coupler <NUM>. A proximal end of distal outer member <NUM> wraps around and is secured to an outer circumference of coupler <NUM> at distal portion <NUM>, and a distal end of proximal outer member <NUM> wraps around proximal inner member <NUM> and is secured to the proximal end surface <NUM> of coupler <NUM>. Distal inner member <NUM>, proximal inner member <NUM>, distal outer member <NUM>, and proximal outer member <NUM> are attached or secured to coupler <NUM> in any suitable manner including using a seam weld, adhesive, a spot weld or crimp weld, clamping, crimping, or any combination thereof.

In some embodiments, the delivery cable may further include an intermediate portion positioned between a distal end of the proximal outer member and a proximal end of the distal outer member. Such an intermediate portion may be more flexible than a proximal-most portion of the delivery cable, but less flexible than a distal-most portion of the delivery cable. Such an intermediate portion may assist in reducing the amount of force applied to a delivery sheath or other delivery device during delivery of a medical device, thus reducing the tendency of the delivery sheath to straighten during delivery of a medical device while still maintaining sufficient column strength to deliver the medical device through the delivery sheath.

For example, <FIG> is a longitudinal cross-sectional view of an embodiment of a delivery cable <NUM> including proximal outer member <NUM>, distal outer member <NUM>, and intermediate outer member <NUM>. Proximal outer member <NUM> is coupled to intermediate outer member <NUM> by coupler <NUM>, and intermediate outer member <NUM> is coupled to distal outer member <NUM> via coupler <NUM> in the same manner described above and illustrated in <FIG> with respect to coupler <NUM>. As shown in <FIG>, the inner member is formed of three separate and distinct portions, including distal inner member <NUM>, proximal inner member <NUM>, and intermediate inner member <NUM>, coupled or secured to one another via couplers <NUM> and <NUM>. In particular, distal inner member <NUM> extends into and is secured to a distal portion <NUM> of coupler <NUM>, and proximal inner member <NUM> extends into and is secured to a proximal portion <NUM> of coupler <NUM>. A proximal end of intermediate inner member <NUM> extends into and is secured to a distal portion <NUM> of coupler <NUM>, and a distal end of intermediate portion <NUM> extends into and is secured to a proximal portion <NUM> of coupler <NUM>.

In one embodiment, illustrated in <FIG>, each of coupler <NUM> and coupler <NUM> are configured similarly to coupler <NUM> illustrated in <FIG>. In such an embodiment, a proximal end of distal outer member <NUM> wraps around and is secured to an outer circumference of coupler <NUM> at distal portion <NUM>, and a proximal end of intermediate outer member <NUM> wraps around and is secured to an outer circumference of coupler <NUM> at a distal portion <NUM>. A distal end of proximal outer member <NUM> wraps around proximal inner member <NUM> and is secured to the proximal end surface <NUM> of coupler <NUM>, and a distal end of intermediate outer member <NUM> wraps around intermediate inner member <NUM> and is secured to the proximal end surface <NUM> of coupler <NUM>.

In another embodiment illustrated in <FIG>, coupler <NUM> is configured such that a distal end of intermediate outer member <NUM> wraps around and is secured to an outer circumference of proximal portion <NUM> of coupler <NUM>. In yet another embodiment illustrated in <FIG>, coupler <NUM> couples only intermediate inner member <NUM> and distal inner member <NUM>, while distal outer member <NUM> extends along the length of distal inner member <NUM>, coupler <NUM>, and intermediate inner member <NUM>. In such an embodiment, coupler <NUM> may have a different inner diameter on a proximal end thereof and a distal end thereof to allow for the use of an intermediate inner member <NUM> and a distal inner member <NUM> of different outer diameters. Distal outer member <NUM> extends across the entire outer surface of coupler <NUM> in this embodiment.

In each of the embodiments described above, distal inner member <NUM>, proximal inner member <NUM>, and intermediate inner member <NUM> as well as distal outer member <NUM>, proximal outer member <NUM>, and intermediate outer member <NUM> may be attached or secured to coupler <NUM> and coupler <NUM> in any suitable manner including using a seam weld, adhesive, soldering, a spot weld or crimp weld, clamping, crimping, swaging, or any combination thereof. Further, each of distal inner member <NUM>, proximal inner member <NUM>, and intermediate inner member <NUM> as well as distal outer member <NUM>, proximal outer member <NUM>, and intermediate outer member <NUM> may have the same or different diameters from one another allowing for each component to be individually sized and configured to allow for the specifically desired strength and flexibility thereof, and couplers <NUM> and <NUM> may be oriented and positioned in any suitable configuration with respect to each of distal inner member <NUM>, proximal inner member <NUM>, and intermediate inner member <NUM> as well as distal outer member <NUM>, proximal outer member <NUM>, and intermediate outer member <NUM> so as to form delivery cable <NUM>. In some embodiments, instead of having a substantially constant rigidity along its entire length, distal outer member <NUM> and/or inner member <NUM> at distal section <NUM> has a transition section <NUM> (shown in <FIG>). In transition section <NUM>, the rigidity of distal outer member <NUM> and/or inner member <NUM> decreases (i.e., increasing flexibility) as distal outer member <NUM> and/or inner member <NUM> extend away from proximal outer member <NUM>. Transition section <NUM> may be sized such that distal outer member <NUM> includes a flexible portion (e.g., having a length of approximately <NUM> to <NUM> inches (<NUM> to <NUM>)) extending beyond transition section <NUM>, and such that the total length of transition section <NUM> and distal outer member <NUM> has a length of approximately <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including <NUM> inches (<NUM>) to <NUM> inches (<NUM>), and including <NUM> inches (<NUM>). For example, if distal outer member <NUM> has an overall length of approximately <NUM> inches (<NUM>), transition section may have a length of approximately <NUM> inches to <NUM> inches (<NUM> to <NUM>). Alternatively, transition section <NUM> may extend substantially the entire length of distal outer member <NUM>. Transition section <NUM> (and/or the flexible portion) may have any dimensions that enable delivery cables <NUM> to function as described herein.

Transition section <NUM> may be formed or created in several different ways. In one example, distal outer member <NUM> may be a multi-strand cable, wherein transition section <NUM> is formed by tapering a wall thickness of distal outer member <NUM> using a swaging or grinding process. In another example, distal outer member <NUM> may be a nitinol cable (e.g., multi-strand or single wire, single layer or double layer), wherein transition section <NUM> is formed via a heat treatment that is varied along distal outer member <NUM>. The varied heat treatment creates a gradual change in an Austenite finish temperature (Af) along distal outer member <NUM>. In another example, transition section <NUM> is formed by varying a pitch of distal outer member <NUM>. In yet another example, transition section <NUM> is formed by applying a variable thickness coating (e.g., a metallic and/or polymer coating) to distal outer member <NUM>. In other embodiments (not shown), transition section <NUM> is formed at a portion of proximal outer member <NUM> as opposed to at a portion of distal outer member <NUM> and/or inner member <NUM>. Such a transition section <NUM> may be formed in any of the methods described above, and may further include the tapering of a distal portion of a proximal inner member <NUM>, such as a proximal inner member illustrated in <FIG>.

In a further example, distal outer member <NUM> including transition section <NUM> is formed by welding two or more outer member segments together end-to-end, with the more distal outer member segments being more flexible than the more proximal outer member segments. The outer member segments may be multi-strand or single wire, single layer or multiple layers, round wire or flat wire, etc. Further, each outer member segment forming distal outer member <NUM> may have different construction and/or different wire diameters than the other outer member segments. In addition, the stiffness of each outer member segment may be varied using the techniques described above.

<FIG> is a schematic view of a tapered wire <NUM> that may be used to form another embodiment of a distal outer member that may be used, for example, with the assembly shown in <FIG>. Tapered wire <NUM> may be formed, for example, using centerless grinding or other suitable techniques. Tapered wire <NUM> extends from a proximal end <NUM> to a distal end <NUM>. Further, tapered wire <NUM> has a first diameter <NUM> at proximal end <NUM> and a second diameter <NUM> at distal end <NUM>. In this embodiment, first diameter <NUM> is larger than second diameter <NUM>. For example, first diameter <NUM> may be in a range from approximately <NUM> inches to <NUM> inches (<NUM> to <NUM>), and second diameter <NUM> may be in a range from approximately <NUM> to <NUM> inches (<NUM> to <NUM>). Alternatively, first and second diameters <NUM> and <NUM> may have any dimensions that enable tapered wire <NUM> to function as described herein.

In one embodiment, tapered wire <NUM> includes a first segment <NUM>, a second segment <NUM>, and a third segment <NUM>. In this embodiment, first segment <NUM> has a constant diameter (e.g., first diameter <NUM>), a diameter of second segment <NUM> gradually tapers (e.g., from first diameter <NUM> to second diameter <NUM>), and third segment <NUM> has a constant diameter (e.g., second diameter <NUM>). Alternatively, tapered wire <NUM> may include any number of segments having any dimensions that enable tapered wire <NUM> to function as described herein.

To form the distal outer member, tapered wire <NUM> is wound into a coil. The resulting distal outer member may have, for example, an overall length in a range from approximately. <NUM> inches to <NUM> inches (<NUM> to <NUM>), and more particularly, of approximately <NUM> inches (<NUM>). Further, the resulting distal outer member may include a transition section (over which the rigidity of the transition distal outer member varies) having a length in a range from approximately. <NUM> inches to <NUM> inches (<NUM> to <NUM>), and more particularly, of approximately. <NUM> inches (<NUM>). Accordingly, tapered wire <NUM> may have, for example, an overall length <NUM> of approximately <NUM> inches (<NUM>), and the distal outer member, including a transition section, may have an overall length of approximately <NUM> inches (<NUM>) to <NUM> inches (<NUM>), including <NUM> inches (<NUM>) to <NUM> inches (<NUM>), and including <NUM> inches (<NUM>). Alternatively, tapered wire <NUM> may have any overall length <NUM>, and the resulting distal outer member may have any total length and transition section length that enables tapered wire <NUM> and the distal outer member to function as described herein.

As indicated above, tapered wire <NUM> (or multiple tapered wires <NUM>) is wound into a coil to form the distal outer member. The coil may be tight wound, open wound, or transition between tight wound to open wound along its length. Transitioning from tight wound to open wound may be accomplished by using a consistent pitch (because the diameter of tapered wire <NUM> changes along the length of tapered wire <NUM>). Alternatively, transitioning from tight wound to open wound may be accomplished using gradual changes in pitch along one portion or the entire length of the coil. Further, tapered wire <NUM> may be used to form any outer member or inner member of the delivery cable described herein.

In other embodiments, instead of the distal outer member having a varying stiffness, and similar to the embodiment described above with respect to <FIG>, the inner core has a varying stiffness. For example, in one such embodiment, the inner core is a solid tapered nitinol core wire, and the distal outer member is a flexible torque member (e.g., a flexible torque member formed from a multi-strand and/or a multi-layer coil or a flexible torque member that may be formed using a laser cut hypotube). In this embodiment, the nitinol core provides tensile strength for the delivery cable, and transitions from stiff to flexible, and the distal outer member (which may be formed of stainless steel or nitinol) provides at least a portion of the torque strength for the delivery cable. Further, in this embodiment, the inner core and distal outer member both terminate at both distal and proximal ends.

Claim 1:
A method (<NUM>) of producing a delivery cable, the method (<NUM>) comprising:
providing (<NUM>) a flexible inner member (<NUM>);
inserting (<NUM>) the inner member (<NUM>) at least partially into a proximal outer member (<NUM>) having a first rigidity;
coupling (<NUM>) the inner member (<NUM>) to the proximal outer member (<NUM>);
inserting (<NUM>) the inner member (<NUM>) into a distal outer member (<NUM>) having a second rigidity less than the first rigidity; and
coupling (<NUM>) the proximal outer member (<NUM>) to the distal outer member (<NUM>).