Patent Description:
This disclosure relates generally to exoskeleton devices for use on the outer surfaces of elongated medical instruments, such as catheters and balloons (e.g., angioplasty balloons, etc.). More specifically, this disclosure relates to exoskeleton devices with expandable sections that may be expanded in a manner that enables the exoskeleton devices to score tissues, plaques, or other targets against which the expanded exoskeleton devices are forced, which may enable further treatment (e.g., with medicines, etc.) treatment of the tissues, plaques, or other targets.

Percutaneous transluminal angioplasty (PTA), which is commonly referred to as balloon angioplasty or, even more simply, as angioplasty, is a commonly used minimally invasive endovascular procedure for treating vessels (e.g., arteries, veins, etc.) whose pathways have been narrowed or obstructed (i.e., stenosis of the vessels). As a non-limiting example, angioplasty is often used to surgically treat arterial atherosclerosis (i.e., the formation of plaques on the insides of arterial walls)-a common cause of stenosis. Angioplasty typically involves introducing a deflated balloon catheter to the narrowed or obstructed portion of the vessel, which may be visually confirmed by fluoroscopy, and then inflating the balloon to force the obstructed or narrowed portion of the vessel, including the atherosclerosis, outward. A stent may be placed at that site to hold the newly revascularized portion of the vessel open. Atherosclerosis or, more specifically, the atherosclerotic plaque typically remains in place following angioplasty.

Angioplasty may be accompanied by treatment with medicines, but that treatment is typically limited to drugs that are administered to the subject for a period of time after the angioplasty procedure has been conducted. As an example, medicines that prevent or treat blood clots (e.g., acetylsalicylic acid (aspirin), an antiplatelet medication (clipidogrel), etc.) may be prescribed to a patent for a period of time (e.g., three months, six months, one year, etc.) after angioplasty and stent placement.

<CIT> and <CIT> are examples of known similar exoskeleton devices in the field.

An exoskeleton device according to this disclosure is capable of use with an expandable instrument (e.g., a balloon catheter, etc.). More specifically, an expandable section of an exoskeleton device may include a lumen that can receive the expandable instrument, including an expander of the expandable instrument (e.g., a balloon of the balloon catheter, etc.). The expandable section of the exoskeleton device, or at least a portion of the expandable section, may be capable of expanding, for example, upon expansion (e.g., inflation, etc.) of the expander of the expandable instrument over which that portion of the expandable section is positioned.

In some embodiments, when the expandable section of an exoskeleton device expands, it may be capable of being forced against and scoring an adjacent surface (e.g., an inner surface of a vessel, a surface of a plaque on an inner surface of a vessel, etc.). In a specific embodiment, the expandable section may include a plurality of struts, or spines, positioned around a circumference of the expandable section. Since the struts are positioned around the circumference of the expandable section, each strut may be somewhat arcuate, but substantially flat. Each strut may extend along a length of the expandable section. As the expandable section or a portion thereof expands (e.g., under radial tension, such as an internal force applied by an expander, etc.), portions of adjacent struts may be forced apart from one another, and each strut may rotate (e.g., by up to about <NUM>°, etc.), causing an edge or a corner thereof to be somewhat radially disposed. When in a radially disposed orientation, the edge or corner of each strut, or spine, may engage, or contact, and even score a surface against which the strut is forced.

In a specific embodiment, the expandable section may comprise or be defined from at least a portion of a body of the exoskeleton device, such as a tube (e.g., a hypotube, etc.), which may be formed from a substantially rigid material, such as a metal (e.g., stainless steel, nitinol (nickel titanium), etc.) or a polymer (e.g., polyether ether ketone (PEEK), etc.). Struts may be defined by adjacent rows of slits, with the slits of each row being offset from, or staggered relative to, the slits of an adjacent row. Each row of slits may be positioned along a generator of the expandable section (i.e., a line extending from one end of the expandable section to the other end of the expandable section, parallel to an axis of the expandable section). Each slit may overlap, or be staggered relative to, about half of one slit (if the slit is located at or near an end of the expandable section) or two slits (if the slit is located intermediately along a length of the expandable section) of an adjacent row; stated another way, the slits of an expandable section may have a so-called "brickwork" arrangement, or they may be arranged like the bricks in a so-called "running bond pattern. " Such an arrangement may enable a portion of a strut to rotate (e.g., by about <NUM>°, by about <NUM>°, etc.) (or cause rotation of that portion of the strut) upon expansion of a portion of the expandable section on which that strut is located or placement of that strut under radial tension. Such an arrangement, along with the material or materials from which the expandable section is formed, may enable an expanded portion of the expandable section to resiliently return to its relaxed state once radial tension (e.g., from an internal force, etc.) on that portion of the expandable section is released (e.g., when pressure from an expander of an expandable instrument within the expandable section is released, etc.). Thus, there may be no need for a separate resilient element on or within the expandable section. With such an arrangement, when the expandable section is an unexpanded state, or in a relaxed state, its outer surface may be smooth or substantially smooth (accounting for discontinuities that occur as material is removed from the tube to form the slit).

The expandable section of the exoskeleton device may also carry a medicament, which may be delivered to the surface that is engaged or scored while that surface is engaged or scored. The medicament may be carried by edges of the struts, or spines, of the exoskeleton device (e.g., coated onto the edges of the struts, etc.). Such a configuration may enable the exoskeleton device to deliver the medicament to a surface upon expanding the expandable section, or a portion thereof, to cause one or more struts, or spines, of the exoskeleton device to score that surface. Alternatively, the medicament may be introduced into a lumen of the exoskeleton device in a manner that enables it to flow onto or through outer surfaces of the struts while the expandable section is in a fully expanded state (e.g., expanded to a limit defined by a vessel or other structure within which the expandable section is disposed, by a balloon or another expandable instrument within the expandable section, and/or by the expandable section itself), in a partially expanded state, or in an unexpanded state, or a relaxed state.

In addition to the expandable section, the exoskeleton device may include a distal section that is capable of introduction into a subject's body (e.g., into a vessel within the body of a subject, etc.). In some embodiments, a collar may be provided around a distal end of the exoskeleton device or around a distal end of the expandable section. The collar may comprise a smooth, even flexible member. Among other functions, the collar may facilitate introduction of the exoskeleton device into the body of a subject and/or prevent expansion of a distal end of the expandable section.

In addition, a body of the exoskeleton device may include a tubular element (e.g., an extension of the expandable section, a catheter, etc.) coextensive with a proximal end of the expandable section. The tubular element may comprise intermediate and proximal portions of the exoskeleton device. The tubular element may include a lumen that can receive an elongated medical instrument, such as an expandable instrument (e.g., a balloon catheter, etc.) and, thus, may enable placement of the exoskeleton device on the elongated medical instrument. A configuration of the tubular element may enable the tubular element and, thus, the exoskeleton device, to engage the elongated medical instrument, optionally securing the tubular element to the elongated medical instrument. The tubular element may comprise an extension of the portion of the body of the exoskeleton device from which the expandable section is formed or defined. Alternatively, the tubular element may comprise a separately manufactured structure that has been aligned with and secured to the portion of the body that forms or defines the expandable section.

In another aspect, a medical system is disclosed. A medical system according to this disclosure includes an exoskeleton device and an expandable instrument, and may also include a guidewire. The exoskeleton device may be capable of placement over the expandable instrument, or of receiving at least a portion of the expandable instrument, including an expander of the expandable instrument. Any embodiment of exoskeleton device according to this disclosure may be included in a medical system with expandable instrument. The expandable instrument may have any configuration suitable for the procedure to be performed using the medical system. Without limitation, the expandable instrument may comprise a balloon catheter with a configuration suitable for use in the procedure to be performed. If a guidewire is included in the medical system, it may have a size (e.g., an outer diameter) suitable for use with the selected expandable instrument and exoskeleton device.

In addition to an exoskeleton device, an expandable instrument, and an optional guidewire, a medical system may include apparatuses that facilitate introduction of the guidewire, the expandable instrument, and/or the exoskeleton device into the body of a subject (e.g., a cannula, an introducer, etc.), apparatuses that work in conjunction with the expandable instrument (e.g., a syringe or another apparatus for expanding the expander of the expandable instrument (e.g., inflating a balloon of a balloon catheter, etc.), etc.), imaging apparatuses, medicaments, and the like.

According to another aspect, methods for using an exoskeleton device are disclosed. Various embodiments of such a method include the introduction of an expandable instrument (e.g., a balloon catheter, etc.) into a subject's body. The expandable instrument may be introduced, or advanced, into the subject's body along a guidewire that was previously placed along a desired path within the subject's body. While advancing the expandable instrument into the subject's body, an expander (e.g., a balloon, etc.) of the expandable instrument may be advanced to a location within the subject's body that is to be treated (e.g., to a narrowed or occluded portion of a vessel, to a plaque in a blood vessel, to a clot, to a diseased or an injured location of a blood vessel, etc.). Advancement of the expandable instrument and its expander may be visualized or otherwise monitored in a manner known in the art (e.g., under fluoroscopy, etc.).

An exoskeleton device may be positioned over the expandable instrument. In some embodiments the exoskeleton device may be positioned over the expandable instrument before the expandable instrument is introduced and advanced into the subject's body and, thus, the exoskeleton device may be introduced and advanced into the subject's body simultaneously with introduction and advancement of the expandable instrument into the subject's body. In other embodiments, the exoskeleton device may be introduced, or advanced, into the subject's body along an expandable instrument that was previously placed along the desired path within the subject's body (e.g., by introducing the expandable instrument into a lumen of the exoskeleton device and introducing and advancing the exoskeleton device over the expandable instrument, etc.). Positioning of the exoskeleton device over the expandable instrument may include placement of an expandable section of the exoskeleton device over an expander of the expandable instrument. If necessary, the position of one or both of the expandable section of the exoskeleton device and the expander of the expandable instrument may be modified or adjusted relative to a location that is to be treated within the subject's body. As an example, the expandable section of the exoskeleton device and the expander of the expandable instrument may be moved together relative to a site that is to be treated. As another example, the expander of the expandable instrument may be moved relative to the expandable section of exoskeleton device and, optionally, relative to a treatment site within body of a subject.

With the expandable section of the exoskeleton device and the expander of the expandable instrument at desired locations within a subject's body, the expander of the expandable instrument may be expanded. Expansion of the expander of the expandable instrument may cause the expandable section of the exoskeleton device to expand. Expansion of the expandable section of the exoskeleton device may force members of the expandable section, including edges or corners of the as struts, against the location that is to be treated. As the edges or corners of the struts of the expandable section are forced against the location that is to be treated, the edges or corners of the struts of the expandable section may engage and even score that location.

Other embodiments of use of an exoskeleton device according to this disclosure may include introduction advancement of the exoskeleton device into a subject's body along a guidewire that was previously placed along a desired path within the subject's body. Advancement of the exoskeleton device may include advancement of an expandable section of the exoskeleton device to a treatment site within the subject's body (e.g., to a narrowed or occluded portion of a vessel, to a plaque in a blood vessel, to a clot, to a diseased or an injured location of a blood vessel, etc.). Advancement of the exoskeleton device and its expandable section may be visualized or otherwise monitored in a manner known in the art (e.g., under fluoroscopy, etc.).

With the exoskeleton device in place, an expandable instrument may be introduced into a lumen of the exoskeleton device and advanced into the subject's body through the exoskeleton device. Advancement of the expandable instrument may continue until an expander of the expandable instrument reaches a desired location within the expandable section of the exoskeleton device, which may be confirmed visually or in any other suitable manner known in the art (e.g., under fluoroscopy, etc.). If necessary, the position of one or both of the expandable section of the exoskeleton device and the expander of the expandable instrument may be modified or adjusted relative to a location that is to be treated within the subject's body.

In embodiments where a relatively short expander of an expandable instrument is moved and used at a plurality of different locations within a relatively long expandable section of an exoskeleton device, the relatively long expandable section may be positioned along a relatively long treatment site. The relatively short expander may be positioned at a first position along the length of the relatively long expandable section. With the relatively short expander at the first position, the relatively short expander may be expanded to cause that portion of the relatively long expandable section to expand, which may cause the edges or corners of struts of the relatively long expandable section to engage or score a first part of the relatively long treatment site. The relatively short expander may then be moved to one or more further locations along the length of the relatively long expandable section and expanded to cause the relatively long expandable section to expand at each further location, which may cause edges of corners of struts at the further location along the length of the expandable section to engage or score (a) corresponding further part(s) of the relatively long treatment site.

In embodiments where the members of the expandable section carry a medicament, the medicament may be transferred to the locations that have been engaged by the edges or corners of struts of the expandable section and introduced into any scores that have been formed at those locations. Thus, use of the exoskeleton device may the direct application of one or more medicaments to a treatment site (e.g., to the cause of a stenosis, such as an atherosclerotic plaque, etc.), and facilitate uptake of the one or more of medicaments by the treatment site.

Once the desired treatment is complete, the expander of the expandable instrument may be contracted (e.g., the balloon of a balloon catheter may be deflated, etc.), enabling the expandable section of the exoskeleton device to transition from an expanded state to an unexpanded state. The expandable section of the exoskeleton device and the expander of the expandable instrument may then be moved (e.g., advanced, withdrawn, etc.) to another treatment site. Alternatively, the exoskeleton device and the expandable instrument may be removed from the subject's body.

Other aspects of the disclosure, as well as features and advantages of various aspects of the disclosed subject matter, will become apparent to those of ordinary skill in the art through consideration of the foregoing disclosure, the accompanying drawings, and the appended claims. The invention is defined by the scope of the claims.

An embodiment of an exoskeleton device <NUM> according to this disclosure is depicted by <FIG>. The exoskeleton device <NUM> comprises an elongated medical device with an expandable section <NUM>. The exoskeleton device <NUM> is at least partially defined by a body <NUM> that includes a distal portion <NUM>, and intermediate portion <NUM>, and a proximal portion <NUM>.

At least part of the distal portion <NUM> of the body <NUM> of the exoskeleton device <NUM> may have a tubular configuration, through which a lumen <NUM> is defined. In the depicted embodiment, the body <NUM> has a tubular configuration along its entire length; thus, the lumen <NUM> extends through the entire length of the body <NUM>.

The body <NUM> may comprise a substantially unitary structure or it may include a plurality of assembled elements that have been secured together. In embodiments where the body <NUM> includes a substantially unitary structure, it may be defined from a single element (e.g., a tube, etc.). An embodiment of the body <NUM> that includes a plurality of assembled elements may include a distal portion <NUM> that is formed separately from and subsequently assembled with and joined to a remainder of the body <NUM>, including its intermediate portion <NUM> and its proximal portion <NUM>.

The body <NUM> may be formed from any of a variety of suitable materials or from a combination of suitable materials. In some embodiments, the entire body <NUM> or its distal portion <NUM> may be defined from or comprise a hypotube, which may be formed from a substantially rigid material, such as a metal (e.g., stainless steel, nitinol, etc.) or a polymer (e.g., polyether ether ketone (PEEK), etc.). In embodiments where the body <NUM> comprises a distal portion <NUM> that has been formed separately from a remainder of the body <NUM>, the remainder of the body <NUM> may be formed from any of a variety of suitable materials, including, without limitation, materials from which catheters may be formed (e.g., silicone, nylon, polyurethane, polyethylene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), latex, etc.), as well as a variety of other materials.

The expandable section <NUM> of the exoskeleton device <NUM> may be capable of expanding outward (e.g., radially outward, etc.) from an unexpanded state, as shown in <FIG>, to an expanded state, as depicted by <FIG>, upon applying an expanding force (e.g., a radially outwardly expanding force, etc.) from within the expandable section <NUM> to inner surfaces <NUM>I of the wall <NUM> of the portion of the body <NUM> from which the expandable section <NUM> is defined. The expandable section <NUM> may be capable of resiliently returning or substantially resiliently returning to the unexpanded state upon removal of the expanding force.

The expandable section <NUM> of the exoskeleton device <NUM> may, as illustrated, be located along the distal portion <NUM> of the body <NUM> of the exoskeleton device <NUM>. A distal side <NUM> of the expandable section <NUM> may be positioned adjacent to a distal end <NUM> of the body <NUM>. Exoskeleton devices with expandable sections that are located at other positions (e.g. more proximal positions) along the lengths of the bodies of the exoskeleton devices (e.g., along at least part of the intermediate portion <NUM>, along at least part of the distal portion <NUM>, etc.) are also within the scope of this disclosure.

The expandable section <NUM> may comprise, or be defined by, at least part of the body <NUM> of the exoskeleton device <NUM>. In the embodiment of exoskeleton device <NUM> illustrated by <FIG> and <FIG>, the expandable section <NUM> is defined by series 34a, 34b, 34c, etc., of slits <NUM> that extend at least partially through a wall <NUM> of the body <NUM>. The slits <NUM> (with the exception of some slits <NUM> located at the ends of the expandable section <NUM>) may have the same lengths as one another. Each slit <NUM> may extend radially through the wall <NUM> (i.e., toward a longitudinal axis <NUM> of the expandable section <NUM>). In some embodiments, each slit <NUM> may extend completely through the wall <NUM> of the body <NUM>, from its outer surface <NUM>O to its inner surface <NUM>I. In other embodiments, each slit <NUM> may extend only partially through the wall <NUM> of the body <NUM> (e.g., from the outer surface <NUM>O of the wall <NUM> toward the inner surface <NUM>I of the wall <NUM>, etc.). The extent to which each slit <NUM> extends through the wall <NUM> of the body <NUM> may depend, at least in part, upon the material from which the body <NUM> is formed. Slits <NUM> may be formed by any technique that is compatible with the material from which the body <NUM> of the exoskeleton device <NUM> is formed. As a non-limiting example, laser cutting processes may be used to form slits <NUM> in the body <NUM>.

Each series 34a, 34b, 34c, etc., may be defined by linearly aligned slits <NUM>. The slits <NUM> and each series 34a, 34b, 34c, etc., may extend longitudinally along the body <NUM>, with each series 34a, 34b, 34c, etc., being positioned along a generator of the expandable section <NUM> (i.e., a line extending from one end of the expandable section <NUM> to the other end of the expandable section <NUM>, parallel to an axis <NUM> of the expandable section <NUM>).

The slits <NUM> of each series 34b, 34c, 34d, etc., may be offset relative to the slits <NUM> of each adjacent series 34a, 34b, 34c, 34d, 34e, etc. Each slit <NUM> in a series 34a, 34b, 34c, etc., may overlap about half of one (if the slit <NUM> is located at or near an end of the expandable section <NUM>) or two (if the slit <NUM> is intermediately located along the length of the expandable section <NUM>) circumferentially adjacent slits <NUM> of each adjacent series 34a, 34b, 34c, etc. Staggering of the slits <NUM> around the circumference of the distal portion <NUM> of the body <NUM> of the exoskeleton device <NUM> may provide the expandable section <NUM> with a so-called "brickwork" appearance, with solid portions of the body <NUM> between the slits <NUM> arranged in a so-called "running bond pattern. " In some embodiments, circumferentially corresponding slits <NUM> of every other series 34a and 34c, etc., of slits <NUM> may have equal lengths and be in complete alignment.

Circumferentially adjacent series 34a, 34b, 34c, etc., of slits <NUM> may be spaced equidistantly around the circumference of the body <NUM>. The expandable section <NUM> may include an even number of series 34a, 34b, 34c, etc., of slits <NUM>. In embodiments where an even number of circumferentially adjacent series 34a, 34b, 34c, etc., of slits <NUM> are spaced equidistantly around the circumference of the body <NUM>, each slit <NUM> of the expandable section <NUM> may be staggered relative to its circumferentially adjacent slits <NUM>.

The solid potions of the body <NUM> that are located between each adjacent pair of series 34a and 34b, 34b and 34c, 34c and 34d, etc., of slits <NUM> comprise struts <NUM> of the expandable section <NUM>. More specifically, each strut <NUM> may comprise a solid portion of the body <NUM> between adjacent series 34a and 34b, 34b and 34c, 34c and 34d, etc., of slits <NUM>. Solid portions of the body <NUM> located between adjacent slits <NUM> in a series 34a, 34b, 34c, etc., of slits <NUM> comprise joints <NUM> between circumferentially adjacent struts <NUM>. Stated another way, each slit <NUM> comprises a gap between a pair of circumferentially adjacent struts <NUM>.

In a specific embodiment of an exoskeleton device according to this disclosure, the body <NUM> may comprise a stainless steel hypotube having an outer diameter (OD) of about <NUM> and an inner diameter (ID) of about <NUM>. Thus, the wall <NUM> of the body <NUM> may have a thickness of about <NUM>. Twelve (<NUM>) series 34a, 34b, 34c, etc., of slits <NUM> may be arranged equidistantly around the circumference of the body <NUM>, defining twelve (<NUM>) struts <NUM> having widths of about <NUM>, accounting for the width of each slit <NUM>. Each slit <NUM> may have a length of about <NUM>, with adjacent slits <NUM> in the same series 34a, 34b, 34c, etc., being spaced about <NUM> apart from each other to define joints <NUM> having lengths of about <NUM>. Circumferentially adjacent slits <NUM> may be offset from one another by about <NUM>.

As illustrated by <FIG>, when the expandable section <NUM> is in its unexpanded state, the outer surface <NUM>O of the wall <NUM> of the portion of the body <NUM> from which the expandable section <NUM> is defined may be substantially smooth, accounting for discontinuities that occur as material is removed from the wall <NUM> of the body <NUM> to form each slit <NUM>. As illustrated by <FIG>, as the expandable section <NUM> starts to expand, the slits <NUM> open up and the struts <NUM> may rotate from circumferentially disposed orientations (i.e., where the outer surface <NUM>O of each strut <NUM> is oriented along the circumference of the wall <NUM> of the body <NUM>) to more radial orientations. All of the struts <NUM> of the expandable section <NUM> may rotate in the same direction (e.g., counterclockwise, clockwise, etc.). As each strut <NUM> begins to rotate, an edge <NUM> of the strut <NUM> is exposed at an outer extent of the expanded expandable section <NUM>. <FIG> shows the expandable section <NUM> in a partially expanded state, or an intermediate state.

<FIG> depict the expandable section <NUM> of the exoskeleton device <NUM> in a fully expanded state. As illustrated by <FIG>, when the expandable section <NUM> is fully expanded, each strut <NUM> may rotate by as much as <NUM>°, with each strut <NUM> being oriented substantially radially.

When the expandable section <NUM> is in an expanded state (i.e., partially expanded, fully expanded, etc.), the struts <NUM> and their at least partially outward facing edges <NUM> may be forced against the location that is to be treated, which may also be referred to herein as a treatment site. As the members of the expandable section are forced against the location that is to be treated, the members of the expandable section may contact that location or even score that location. In embodiments where the members of the expandable section carry a medicament, the medicament may be transferred from the struts <NUM> to the location that has been treated. The medicament may also be introduced into any scores formed at the location that has been treated.

With returned reference to <FIG> and <FIG>, a distal end <NUM> of the exoskeleton device <NUM> may have a configuration that enables its introduction into a subject's body (e.g., into a vessel within the body of a subject, etc.) and its advancement through the subject's body. In some embodiments, the distal end <NUM> of the exoskeleton device <NUM> may have a frustoconical configuration (i.e., it may have the shape of a truncated cone, which lacks a pointed tip). Such a configuration of distal end <NUM> may have a gradual taper (e.g., a taper of about <NUM>°, a taper of about <NUM>°, a taper of about <NUM>°, etc.).

A collar <NUM> may be provided at the distal end <NUM> of the exoskeleton device <NUM> and/or at a distal side of the expandable section <NUM> of the exoskeleton device <NUM>. The collar <NUM> may facilitate introduction of the exoskeleton device <NUM> into a subject's body, as well as advancement of the exoskeleton device <NUM> through the subject's body. Such a collar <NUM> may be smooth and, optionally, flexible (e.g., it may be formed from a flexible, resilient material, such as silicone, etc.). In some embodiments, the collar <NUM> may be provided around a distal end of the expandable section <NUM> to limit expansion at the distal end of the expandable section <NUM>.

A radiopaque marker <NUM> may be provided at the distal end <NUM> of the exoskeleton device <NUM>. The distal end <NUM> may be formed from a radiopaque material (e.g., platinum, etc.) to define the radiopaque marker <NUM>, or a band of radiopaque material may be placed at or near the distal end <NUM> of the exoskeleton device <NUM> (e.g., directly adjacent to a distal side of the expandable element <NUM>, etc.). The radiopaque marker <NUM> may enable visualization (e.g., through fluoroscopy, etc.) of a location of the exoskeleton device <NUM> and/or its expandable section <NUM> within a subject's body.

As illustrated by <FIG> and <FIG>, the intermediate portion <NUM> of the exoskeleton device <NUM> is located on a proximal side of the expandable section <NUM>, and the proximal portion <NUM> of the exoskeleton device <NUM> is located on a proximal side of the intermediate portion <NUM>, closest to an individual (e.g., a healthcare professional, etc.) introducing, advancing, and/or operating the exoskeleton device <NUM> and any associated devices.

The intermediate portion <NUM> and/or the proximal portion <NUM> of the exoskeleton device <NUM> may be capable of receiving and/or otherwise engaging one or more other elongated medical instruments (e.g., a guidewire, one or more expandable instruments, etc.) (not shown in <FIG>), including elongated medical instruments that are capable of expanding the expandable section <NUM> of the exoskeleton device <NUM> and other medical devices with which the exoskeleton device <NUM> may be used. In some embodiments, the intermediate portion <NUM> and, optionally, the proximal portion <NUM> of the exoskeleton device <NUM> may comprise a tubular element coextensive with a proximal side of the expandable section <NUM>. The tubular element may include a lumen that can receive the one or more other elongated medical instruments. In some embodiments, the intermediate portion <NUM> and, optionally, the proximal portion <NUM> of the exoskeleton device <NUM> may comprise an extension of the body <NUM> of the exoskeleton device <NUM>. Alternatively, the proximal portion <NUM> and, optionally, the intermediate portion <NUM> of the exoskeleton device <NUM> may comprise another separately manufactured structure (e.g., a catheter, another tube, a tether, etc.) that may be aligned with and is secured to a proximal end of the body <NUM> of the exoskeleton device <NUM>.

Turning now to <FIG>, embodiments of various techniques for introducing an exoskeleton device <NUM> (<FIG>) of this disclosure into a body of a subject are depicted.

In <FIG>, an embodiment of a technique for introducing an expandable element <NUM> of an exoskeleton device <NUM> to a treatment site S, or a target location, within a body of a subject is shown. In that method, a guidewire W is introduced into the subject's body and advanced to and, optionally, through the treatment site S in a manner known in the art. The treatment site S shown in <FIG> is a narrowed or occluded location along a vessel V (e.g., a blood vessel, such as an artery or a vein, etc.); it should be noted, however, that the expandable section <NUM> of the exoskeleton device <NUM> may be used to treat other organs or features of a subject's anatomy. In <FIG>, the exoskeleton device <NUM> and an expandable instrument <NUM> are pre-assembled, with an expandable section <NUM> of the exoskeleton device <NUM> positioned over an expander <NUM> of the expandable instrument <NUM>. Preassembly of the exoskeleton device <NUM> and the expandable instrument <NUM> may include securing the exoskeleton device <NUM> to the expandable instrument <NUM>. The exoskeleton device <NUM> and the expandable instrument <NUM> may then be placed over the guidewire W and introduced into the subject's body together (i.e., simultaneously), and advanced along the guidewire W until the expandable section <NUM> and the expander <NUM> reach the treatment site S.

<FIG> illustrates another embodiment of a technique for introducing an expandable element <NUM> of an exoskeleton device <NUM> to a treatment site S within a subject's body. In the method depicted by <FIG>, a guidewire W (<FIG>) is first introduced into the subject's body and advanced through the subject's body to and, optionally, through the treatment site S. With the guidewire W in place, an expandable instrument <NUM> may then be introduced into the subject's body and advanced through the subject's body until an expander <NUM> at or near a distal end of the expandable instrument <NUM> reaches the treatment site S. With the expander <NUM> at the treatment site S, the guidewire W may, in some embodiments, be removed from the expandable instrument <NUM> and, thus, from the subject's body. The exoskeleton device <NUM> may be positioned over the expandable instrument <NUM> (e.g., a proximal end of the expandable instrument <NUM> may be placed in a lumen <NUM> (<FIG>) of the exoskeleton device <NUM>, etc.) and, if the guidewire W remains in place, over the guidewire W. The exoskeleton device <NUM> may then be introduced into the subject's body and advanced over the expandable instrument <NUM>, through the subject's body until the expandable section <NUM> is positioned over the expander <NUM> and at the treatment site S.

<FIG> depicts an embodiment of an exoskeleton device <NUM> introduction and advancement method that includes introducing a guidewire W (<FIG>) into the subject's body, advanced through the subject's body to the treatment site S, and, optionally, advanced through the treatment site. With the guidewire W in place, the exoskeleton device <NUM> may then be introduced into the subject's body and advanced through the subject's body until an expandable section <NUM> of the exoskeleton device <NUM> reaches the treatment site S. With the expandable section <NUM> at the treatment site S, the guidewire W may, in some embodiments, be removed from the exoskeleton device <NUM> and, thus, from the subject's body. An expandable instrument <NUM> may be assembled with a proximal portion <NUM> (<FIG> and <FIG>) of the exoskeleton device <NUM> (e.g., introduced into a lumen <NUM> (<FIG>) of the exoskeleton device <NUM>, etc.), and then advanced into the subject's body along the exoskeleton device <NUM> (e.g., through the lumen <NUM> of the exoskeleton device <NUM>, etc.), until an expander <NUM> of the expandable instrument <NUM> is positioned at a desired location within the expandable section <NUM> of the exoskeleton device <NUM> and, thus, at the treatment site S.

Regardless of how the expandable section <NUM> of the exoskeleton device <NUM> is introduced to the treatment site S and over the expander <NUM> of the expandable instrument <NUM>, with the expandable section <NUM> of the exoskeleton device <NUM> at the treatment site S and the expander <NUM> of the expandable instrument <NUM> within the expandable section <NUM>, as shown in <FIG>, the expander <NUM> may be expanded in a suitable manner to expand the expandable section <NUM> (e.g., a balloon of a balloon catheter may be inflated, etc.), as illustrated by <FIG>. With added reference to <FIG> and <FIG>, expansion of the expandable section <NUM> may cause edges <NUM> of the struts <NUM> of the expansion of the expandable section <NUM> may cause edges <NUM> of the struts <NUM> of the expandable element <NUM> to contact and, optionally, score locations of the treatment site S (e.g., a diseased site, such as the site of an atherosclerotic plaque or the like; a wounded site; etc.) against which the edges <NUM> of the struts <NUM> are forced.

Claim 1:
An exoskeleton device (<NUM>) capable of assembly with an expandable instrument (<NUM>), comprising:
an expandable section (<NUM>) capable of placement over an expander (<NUM>) of an expandable instrument (<NUM>), the expandable section (<NUM>) including a plurality of struts (<NUM>), each strut (<NUM>) extending along a length of the expandable section (<NUM>) with the plurality of struts (<NUM>) being positioned around a circumference of the expandable section (<NUM>), each strut (<NUM>) of the plurality of struts (<NUM>) including a plurality of sections, each section defined by a pair of parallel slits (<NUM>) through the expandable section (<NUM>), each slit (<NUM>) of the pair of parallel slits (<NUM>) separating circumferentially adjacent sections of circumferentially adjacent struts (<NUM>) of the plurality of struts (<NUM>), an arrangement of slits (<NUM>) of the expandable section (<NUM>) rendering the expandable section (<NUM>) radially expandable and characterized in that, each strut (<NUM>) is rotatable from a circumferentially disposed orientation to a more radial orientation such that an edge of the strut is exposed at an outer extent of the expandable section upon radial expansion of the expandable section (<NUM>).