WO2024072447A1

WO2024072447A1 - Devices, catheter assemblies, and methods of using the same

Info

Publication number: WO2024072447A1
Application number: PCT/US2022/077214
Authority: WO
Inventors: Scott L. Randall
Original assignee: Bard Peripheral Vascular, Inc.
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2024-04-04

Abstract

In embodiments, a device for atherectomy includes a catheter tip that includes a body and a plurality of smooth, rounded protrusions extending radially from the body. The body and the plurality of smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel.

Description

DEVICES, CATHETER ASSEMBLIES, AND METHODS OF USING THE SAME

TECHNICAL FIELD

[0001] The present disclosure relates to devices, catheters assemblies, and methods for using the same, and more particularly devices, catheter assemblies, and methods for removing occlusions within a vessel.

BACKGROUND

[0002] Peripheral Artery disease may be caused, for example, by atherosclerosis. Atherosclerosis occurs when fat, cholesterol, and/or other substances build up in the walls of blood vessels, forming hard structures called occlusions, e.g., plaques and/or atherosclerotic (stenotic) lesions. Over time, these occlusions may increase in size such that the blood vessels are substantially clogged and/or completely blocked, so as to form a total chronic occlusion (CTO). The occlusions may not just form within the true lumen of the blood vessel, but may also build up in the medial and intimal layers of a blood vessel, resulting in a stiffening of the blood vessel wall.

[0003] Current systems and methods to remove occlusions in blood vessels include rotational atherectomy and ultrasound-based atherectomy. Rotational atherectomy generally includes an abrasive element attached to a rotatable elongate flexible drive shaft. The abrasive element may be referred to as a burr, crown, and/or bead. As the abrasive element rotates, it engages the surface of the occlusion and abrades or otherwise breaks up the occlusion into smaller particles. Ultrasound-based atherectomy generally includes a core wire driven at high frequencies to cavitate and “hammer” an occlusion to abrade or break the occlusion into smaller particles. However, such systems are often ineffective to remove occlusions that have grown within the medial or intimal tissue of the vessel without unwanted tissue abrasion.

SUMMARY

[0004] In one embodiment, a catheter tip for atherectomy having a catheter tip that includes a body and a plurality of smooth, rounded protrusions extending radially from the body. The body and the plurality of smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel.

[0005] In another embodiment, a catheter assembly for atherectomy includes an elongate member and a catheter tip positioned at a distal end of the elongate member. The catheter tip includes a body and a plurality of smooth, rounded protrusions extending from the body. The smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel

[0006] In another embodiment, a method of breaking calcified lesions includes advancing a catheter assembly to a position in a vessel. The catheter includes an elongate member and a catheter tip positioned at a distal end of the elongate member. The catheter tip includes a body and a plurality of smooth, rounded protrusions extending from the body. The method further includes activating the catheter tip to break up an occlusion with the catheter tip, wherein the catheter tip is rotated or vibrated at a frequency sufficient to break up the occlusion in the vessel.

[0007] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0009] FIG. 1 schematically depicts a side view of a catheter assembly, according to one or more embodiments shown and described herein;

[0010] FIG. 2 schematically depicts an ultrasound-based atherectomy system including the catheter assembly of FIG. 1 , according to one or more embodiments shown and described herein;

[0011] FIG. 3 schematically depicts one or more components of a rotational atherectomy system including the catheter assembly of FIG. 1, according to one or more embodiments shown and described herein;

[0012] FIG. 4 schematically depicts a side view of a catheter tip, according to one or more embodiments shown and described herein;

[0013] FIG. 5 schematically depicts a side view of a catheter tip, according to one or more embodiments shown and described herein; [0014] FIG. 6 schematically depicts a top view of a surface area of an “unraveled” body of a catheter tip, according to one or more embodiments shown and described herein;

[0015] FIG. 7 schematically depicts a top view of a surface area of an “unraveled” body of a catheter tip, according to one or more embodiments shown and described herein;

[0016] FIG. 8 schematically depicts an axial view of a distal surface of a catheter tip, according to one or more embodiments shown and described herein;

[0017] FIG. 9 schematically depicts an axial view of a distal surface of a catheter tip, according to one or more embodiments shown and described herein;

[0018] FIG. 10 schematically depicts a side view of a catheter tip, according to one or more embodiments shown and described herein;

[0019] FIG. 11 schematically depicts a side view of a protrusion of a catheter tip, according to one or more embodiments shown and described herein;

[0020] FIG. 12 schematically depicts a side view of a protrusion of a catheter tip, according to one or more embodiments shown and described herein;

[0021] FIG. 13 schematically depicts a cross-sectional view of a distal end of an elongate member of the catheter assembly of the rotational atherectomy system of FIG. 3, with a catheter tip coupled thereto, according to one or more embodiments shown and described herein;

[0022] FIG. 14 schematically depicts a cross-sectional view of a distal end of an elongate member of the catheter assembly of the rotational atherectomy system of FIG. 3, with a catheter tip coupled thereto, according to one or more embodiments shown and described herein;

[0023] FIG. 15 schematically depicts a cross-sectional view of a distal end of an elongate member of the catheter assembly of the ultrasound-based atherectomy system of FIG. 3, with a catheter tip coupled thereto, according to one or more embodiments shown and described herein;

[0024] FIG. 16 schematically depicts a cross section of a blood vessel including several occlusions formed within various layers of the blood vessel, according to one or more embodiments shown and described herein; and

[0025] FIG. 17 schematically depicts a cross section of the blood vessel of FIG. 16 with the distal end of the elongate member of FIG. 4 positioned therein performing an atherectomy procedure, according to one or more embodiments shown and described herein. DETAILED DESCRIPTION

[0026] As noted above, conventional rotational and ultrasound-based atherectomy devices may be used to break calcified lesions in blood vessels. The catheter tips used in such systems, generally include diamond coated, or otherwise abrasive burrs that may be traumatic to soft tissue. This may be particularly undesirable when attempting to break up occlusions formed in medial and intimal layers in a blood vessel. Particularly, supplying sufficient force to a vessel wall to break the convention atherectomy catheter tips may damage or injure the soft tissue of the blood vessel. Embodiments described herein include catheter tips, catheter assemblies, and methods that address the one or more aforementioned limitations. In particular, the catheter tips described herein generally include a body and smooth, rounded protrusions extending from the body. The smooth, rounded protrusions are configured (e.g., shaped) to break occlusions, such as occlusions formed in the medial and intimal layers of a vessel without damaging soft tissue. For example, the rounded protrusions may decrease the contacting surface area of the catheter tip the vessel wall. Moreover, in being smooth, or void of sharp edges or rough surface modifications, such as a diamond coating, the protrusions may impart sufficient force against a vessel wall to break occlusions, such as calcified lesion, in the medial and intimal layers of the vessel without damaging the soft tissue of the vessel wall. Various embodiments will now be described in greater detail below with reference to the figures.

[0027] As used herein, the term “proximal” means closer to or in the direction of an origin of an element, such as a catheter assembly. For example, the origin of a catheter assembly may be a hand piece or other user-manipulated portion of the catheter assembly. The term “distal” means further from the origin, or hand piece, of the catheter assembly. Put another way, the term “distal” means closer to or in the direction of a tip of a catheter assembly, which is separated from a hand piece of the catheter assembly by a length of an elongate member of the catheter assembly.

[0028] As used herein, the term “occlusion” may include any deposit or blockage within a blood vessel (e.g., a vein or artery). For example, occlusions may be from blood clots, calcified lesions, calcium deposits, cholesterol deposits, plaques and/or atherosclerotic (stenotic) lesions. Occlusion may be used interchangeably with the term “lesion.”

[0029] Referring now to FIG. 1, a catheter assembly 100 is generally depicted. The illustrated catheter assembly 100 includes a hand piece 110 and an elongate member 120 that extends distally (e.g., in the -x direction of the coordinate axes of FIG. 1) from the hand piece 110. The catheter assembly 100 further includes a catheter tip 400 positioned at a distal end of the elongate member 120. It is noted that the catheter assembly 100 may include a fewer or greater number of components without departing from the scope of the present disclosure.

[0030] Referring now to FIG. 2, in embodiments, as will be discussed in further detail below, the catheter assembly 100 may be incorporated into an ultrasound-based atherectomy system 200, such as schematically illustrated in FIG. 2. In such embodiments, the catheter assembly 100 may be coupled to a console 210 that provides a system operator an instrument for monitoring and controlling the catheter assembly 100 and various other sub-systems and functions of the atherectomy system 200. The console 210 may include an ultrasound-producing mechanism including an ultrasound generator 220 and an ultrasound transducer 230. The ultrasoundproducing mechanism can be configured to convert an electric current into a vibrational energy. For example, the ultrasound generator 220 can be configured to convert an alternating electric current (e.g., a current associated with mains electricity) into a high frequency current (e.g., a current with a frequency commensurate with the operating frequency of the ultrasound transducer), and the ultrasound transducer 230, in turn, can be configured to convert the high- frequency current into the vibrational energy (e.g., > 20 kHz, such as 20.5 kHz± 500 Hz) sufficient to disrupt (e.g., break apart) an occlusion.

[0031] In embodiments, the console 210 may further include a user interface such as, but not limited to, a switch 240 (e.g., a foot switch) configured to activate and deactivate the atherectomy system 200, such as activate and deactivate the ultrasound generator 220 and/or the ultrasound transducer 230 to drive, for example, a core wire 156 (FIG. 15) of the catheter assembly 100. For example, when the atherectomy system 200 is powered on but not activated, the switch 240 can be used to activate the atherectomy system 200, thereby activating the core wire 156 (FIG. 15) of the catheter assembly 100. When the atherectomy system 200 is powered on and activated, the switch 240 can be used to deactivate the atherectomy system 200, thereby deactivating the core wire 156 (FIG. 15) of the catheter assembly 100. In embodiments, the user interface may not be a switch, but may include any number of buttons, wheels, touchscreens, toggles, or the like.

[0032] In embodiments, the console 210 may further include an injector 250 configured to inject an irrigant into an irrigation lumen 170 (FIG. 15) of the catheter assembly 100. The irrigant may be, for example, sterile saline for irrigating an anatomical area undergoing an atherectomy procedure, cooling the core wire 156 (FIG. 15) of the catheter assembly 100, or a combination thereof. In embodiments, the switch 240 may further be configured to activate and deactivate the injector 250 simultaneously or separately to activating the ultrasound generator 220 and/or the ultrasound transducer 230. In some embodiments, there may be provided a separation user input (e.g., switch, toggle, button, wheel, etc.), for independent activating and/or deactivating the injector 250.

[0033] It is noted that in embodiments, the system may be entirely handheld as opposed to having a separate console. More specifically, one or more or all of the ultrasound generator 220, switch 240 and injector 250 may be provided in hand piece 110.

[0034] Referring now to FIG. 3, in other embodiments, as will be discussed in further detail below, the catheter assembly 100 may be incorporated into a rotational atherectomy system 300. In such embodiments, the rotational atherectomy system 300 may include a driver assembly positioned in the hand piece 110 of the catheter assembly 100 that is configured to rotate the elongate member 120, or portions thereof, at high speeds (e.g., 20,000-160,000 rpm) sufficient to disrupt (e.g., break up) an occlusion (it will be appreciated that the minimum speed to disrupt the occlusion will depend on the type and size of occlusion). In such embodiments, the elongate member 120 may include a drive shaft 150 (FIGS. 13, 14) extending therethrough and coupled to the catheter tip 400 (FIG. 1). The drive shaft 150 (FIG. 13, 14) may be flexible so as to be adaptable to the curvature of the vasculature. In embodiments, the atherectomy system 300 may similarly include the injector 250 (FIG. 2). Irrigant or lubricant, such as saline, may be supplied from the injector 250 (FIG. 2) through an irrigation lumen 170 (FIGS. 13, 14) of the catheter assembly 100 to cool/lubricate the coil shaft/guidewire interface, and/or irrigate an anatomical area undergoing an atherectomy procedure, as is known in the art.

[0035] The hand piece 110 may include a motor 310, such as a direct current (DC) motor, a motor controller circuit 320, and a user interface 330. An on-board battery power supply 340 may be connected in electrical communication with the motor 310, motor controller circuit 320, and user interface 330. Electrical power may be supplied to the motor 310, motor controller circuit 320, and user interface 330 via the on-board battery power supply 340. Alternatively, an off-board power source, such as an alternating current (AC) wall outlet, may be connectable to the handpiece 110 to supply electrical power to the hand piece 110 and components therein. The user interface 330 may be, for example, a touch screen or panel having one or more physical or virtual buttons, switches, dials, levers, or the like for supplying user input commands to the motor controller circuit 320. The motor controller circuit 320 may include processing circuitry and power circuitry, so as to receive the user input commands, execute program instructions, and supply power and operational signals to the motor 310. Such user input commands may include, for example, selectable rotational speed commands, motor acceleration and/or torque profile commands, and/or rotational direction commands.

[0036] Referring now to FIG. 4, a distal end of the elongate member 120 of the catheter assembly 100 (FIG. 1) is depicted. The elongate member 120 may generally include a support catheter 130 that houses the core wire 156 or drive shaft 150 briefly described above and in more detail below. That is the support catheter 130 may have a lumen extending therethrough that provides communication of the driving energy to break up the occlusion from the handle 110 to the catheter tip 400.

[0037] The catheter tip 400 is positioned at a distal end of the elongate member 120 distal to the support catheter 130. Accordingly, in embodiments, the catheter tip 400 is positioned at a distal end of the support catheter 130. The catheter tip 400 generally includes a body 402. The body may be mounted to the elongate member such that a center of mass of the elongate member 120 is centered on a central longitudinal axis of the elongate member or the body 402 may be asymmetrically mounted to the elongate member 120. The body 402 may be generally cylindrically shaped as shown so as to have an outer radial surface 404 and a distal end surface 406 facing distally (e.g., the -X direction of the depicted coordinate axes). In embodiments, the body 402 of the catheter tip 400 may take any desirable shape and have any desirable cross section. In embodiments, the catheter tip 400 may be sized to navigate through select vasculature of a subject.

[0038] The catheter tip 400 includes one or more protrusions 410 thereon. The protrusions 410 are rounded. That is, the protrusions 410 lack sharp points, edges, lips, and/or the like along the surfaces of the protrusions 410 that may otherwise operate to tear, cut, or abrade some tissue. The protrusions 410 are smooth. In other words, the protrusions 410 are substantially free of surface modifications or coatings, such as a diamond coating, that would provide the protrusions 410 with a rough or abrasive exterior. In being smooth and rounded, the protrusions 410 may be atraumatic, such that the protrusions 410 do not damage soft tissue, as discussed further below. For example, a surface of the protrusions 410 may be polished or otherwise non-abrasive. Soft tissue, as used herein, includes muscle, fat, blood vessels, nerves, fascia, tendons, endothelium and other tissue that is not ossified or calcified.

[0039] The protrusions 410 may be positioned on and extend from the outer radial surface 404 of the body 402 of the catheter tip 400. In some embodiments, on or more of the protrusions 410 may be positioned on and extend longitudinally from the distal surface 406 the catheter tip 400. In the illustrated embodiment, the distal surface 406 of the catheter tip 400 tip is substantially flat or planar. In such embodiments, distal surface 406 of the catheter tip 400 may arranged be orthogonal to the longitudinal centerline (e.g. in the direction of the x-axis of the coordinate axes of FIG. 4) of the catheter tip 400. In other embodiments, the distal surface 406 of the catheter tip 400 may be angled at some oblique angle relative to the longitudinal centerline (e.g. in the direction of the x-axis of the coordinate axes of FIG. 4) of the catheter tip 400.

[0040] The catheter tip 400 may be made of any material suitable for insertion into a blood vessel or other bodily lumen for atherectomy. Generally, the catheter tip 400 may be made of tungsten, titanium, iron, chromium, vanadium, or combinations thereof. In embodiments, the body 402, distal surface 406, and the protrusions 410 may be made of the same material. In other embodiments, at least one of the body 402, the distal surface 406, and the protrusions 410 may be made of a different material than the remainder of the catheter tip 400.

[0041] In embodiments, the protrusions 410 may be integral with the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400 so that the protrusions 410 form a unitary body with the body 402 and/or the distal surface 406. That is, during manufacturing, the protrusions 410 may be directly shaped, molded, etched, or otherwise formed in the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400. In other words, in embodiments, the entirety of the catheter tip 400 may be formed in or from a single sample of bulk material. In such embodiments, it should be appreciated that the protrusions 410 do not move relative the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400. In other embodiments, the protrusions 410 may be modularly formed with (e.g., attached to) the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400. That is, during manufacturing, the protrusions 410 may be shaped from a separate sample of bulk material than the remainder of the catheter tip 400. The protrusions 410 may then be fixed to the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400 by welding, adhesive, or other fixation means. In such embodiments, it should be appreciated that the protrusions 410 are fixedly secured to the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400 such that the protrusions 410 do not move relative the body 402 of the catheter tip 400 and/or the distal surface 406 of the catheter tip 400. In some embodiments, it is contemplated that the body 402 may be formed of a softer material than the protrusions 410. In such embodiments, the body 402 may act as a shock absorber to absorb at least a portion of the shock from the protrusions 410 making contact with a lesion.

[0042] Referring now to FIG. 5, another embodiment of a catheter tip 500 is depicted. The catheter tip 500 may resemble the catheter tip 400 discussed with respect to FIG. 4 in all aspects except as discussed herein. That is, like components of the catheter tip 500 may mirror those of the catheter tip 400 unless specified. For instance, similar to the catheter tip 400, the catheter tip 500 may take any suitable shape and may for example include a body 502 having an outer radial surface 504 and a distal surface 506. The catheter tip 500 includes smooth, rounded protrusions 510 that may be positioned on and extend from the outer radial surface 504 of the body 502 and/or from the distal surface 506 of the catheter tip 500. However, in the present embodiment, instead of being planar, the distal surface 506 may be rounded or parabolic as shown. That is, the distal surface 506 may extend distally (e.g. in the direction of the -x axis of the coordinate axes of FIG. 5) from a distal edge 505 of the outer radial surface 504. By providing a rounded distal surface 506, the surface area of the distal surface 506 may be increased allowing for more protrusions 510 to be formed thereon. Moreover, the rounded distal surface 506 may aid in navigating the catheter tip 500 through tortuous vasculature of a subject. The rounded distal surface 506 may be provided in embodiments where the catheter tip body is not cylindrical.

[0043] Referring now to FIG. 6, an “unraveled” plan or flattened view of the surface area of an outer radial surface 604 of a body 602 of a catheter tip is depicted. The outer radial surface 604 may resemble the outer radial surfaces 404, 504 discussed with respect to FIGS. 4 and 5, respectively, in all aspects except as discussed herein. That is, like components of the body 602 may mirror those of the bodies 402, 502 unless specified. For instance, the catheter tip body 602 may include a plurality of smooth, rounded protrusions 610 positioned on and extending from the outer radial surface 604. It should be appreciated that the outer radial surface 604 may be incorporated in the catheter tips 400, 500 discussed with reference to FIGS. 4 and 5, respectively. For ease of illustration and discussion, the outer radial surface 604 of the body 602 is depicted as unraveled such that the entire surface area of the outer radial surface 604 of the body 602 is depicted in a single x-z plane according to the coordinate axes of FIG. 6. In embodiments, the protrusions 610 may be arranged on the outer radial surface 604 of the catheter tip at any desirable spacing, distance, or pattern. For instance, as depicted in FIG. 6, the protrusions 610 may be symmetrically positioned along the outer radial surface 604 of the body 602. That is, when the outer radial surface 604 is “unraveled” in a two-dimensional plane, as depicted, the protrusions 610 may be symmetrically arranged about a center point 603 of the outer radial surface 604 of the body 602 and/or a line passing through the center point 603 of the outer radial surface 604 of the body 602. It should be appreciated that the protrusions 610 may be symmetrically positioned along the body 602 about more than one line of symmetry. Similarly, it should be appreciated that the protrusions 610 may display any form of symmetry in their positioning along the body 602. For instance, the protrusions 610 may display reflectional symmetry, rotational symmetry, translational symmetry, glide reflection symmetry, and/or any other form of symmetry in their positioning along the body 602.

[0044] Referring now to FIG. 7, an unraveled plan or flattened view of the surface area of an outer radial surface 704 of a body 702 of a catheter tip is depicted. The outer radial surface 704 may resemble the outer radial surfaces 404, 504 of the bodies 402, 502 discussed with respect to FIGS. 4 and 5, respectively, in all aspects except as discussed herein. That is, like components of the body 702 may mirror those of the bodies 402, 502 unless specified. For instance, the body 702 may include a plurality of smooth, rounded protrusions 710 positioned on and extending from the outer radial surface 704. It should be appreciated that the body 702 may be incorporated in the catheter tips 400, 500 discussed with reference to FIGS. 4 and 5, respectively. For ease of illustration and discussion, the catheter tip body 702 is “unraveled” such that the entire surface area of the outer radial surface 704 of the tip body 702 is depicted in a single x-z plane according to the coordinate axes of FIG. 7. In embodiments, the protrusions 710 may be asymmetrically positioned along the tip body 702. That is, when the outer radial surface 704 is “unraveled” in a two-dimensional plane, as depicted, the protrusions 710 may be asymmetrically arranged about a center point 703 of the outer radial surface 704 of the body 702 and/or a line passing through the center point 703 of the outer radial surface 704 of the body 702. Asymmetrically arranging the protrusions 710 may cause the tip to wobble back and forth during use, which may lead to larger lumen creation as opposed to a symmetrical tip.

[0045] Referring now to FIG. 8, a plan view of a distal surface 806 of a catheter tip is depicted. The distal surface 806 may resemble the distal surface 406, 506 discussed with respect to FIGS. 4 and 5, respectively, in all aspects except as discussed herein. That is, like components of the distal surface 806 may mirror those of the distal surfaces 406, 506 unless specified. The distal surface 806 may be flat as shown in Fig. 4 or rounded as shown in Fig. 5, in some embodiments, the distal surface may be concave (not shown). For instance, the distal surface 806 may include one or more smooth, rounded protrusions 810 positioned on and extending therefrom. It should be appreciated that the distal surface 806 may be incorporated in the catheter tips 400, 500 discussed with reference to FIGS. 4 and 5, respectively. It should be appreciated that the distal surface 806 may be incorporated in a catheter tip, such as the catheter tips 400, 500 discussed with references to FIGS. 4 and 5, respectively, as either a flat distal surface or a rounded distal surface.

[0046] In embodiments, the protrusions 810 may be arranged on the distal surface 806 at any desirable spacing, distance, or pattern. For instance, as depicted in FIG. 8, the protrusions 810 may be symmetrically positioned along the distal surface 806 such as about a center point 803. It should be appreciated that the protrusions 810 may be symmetrically positioned along the distal surface 806 about more than one line of symmetry. Similarly, it should be appreciated that the protrusions 810 may display any form of symmetry in their positioning along the distal surface 806. For instance, the protrusions 810 may display reflectional symmetry, rotational symmetry, translational symmetry, glide reflection symmetry, and/or any other form of symmetry in their positioning along the distal surface 806.

[0047] Referring now to FIG. 9, an axial view of the surface area of a distal surface 906 of a catheter tip is depicted. The distal surface 906 may resemble the distal surface 406, 506 discussed with respect to FIGS. 4 and 5, respectively, in all aspects except as discussed herein. That is, like components of the distal surface 906 may mirror those of the distal surfaces 406, 506 unless specified. For instance, the distal surface 906 may include one or more smooth, rounded protrusions 910 positioned on and extending therefrom. It should be appreciated that the distal surface 906 may be incorporated in the catheter tips 400, 500 discussed with reference to FIGS. 4 and 5, respectively. Accordingly, the distal surface 906 may be either a flat distal surface or a rounded distal surface. In embodiments, the protrusions 910 may be asymmetrically positioned along the distal surface 906 about a center point 903 of the distal surface 906.

[0048] In any of the above-described embodiments, whether symmetrically or asymmetrically positioned along the outer radial surface of the body of a catheter tip and/or the distal surface of the catheter tip, the protrusions may be particularly arranged for use at a specific site in a subject’s vasculature and/or for use on a specific calcified lesion, as discussed in further detail below. For example, lesions formed within a vessel may result in a total occlusion that has a cap that is convex. When approaching the convex cap, traditional devices may be directed transversely toward a wall of the vessel as opposed to engaging the occlusion centrally, which may make occlusion removal difficult. In embodiments, protrusions may be arranged, such as symmetrically arranged on the distal surface 906 of the catheter tip to center the head relative to the cap for removal. In some embodiments, asymmetrical arrangement may cause the catheter tip to wobble or provide a larger arc for impacting a lesion, which may be beneficial in larger vessels.

[0049] Referring now to FIG. 10, a catheter tip 1000 is depicted. The catheter tip 1000 may resemble the catheter tips 400, 500 discussed with respect to FIGS. 4 and 5, respectively, in all aspects except as discussed herein. That is, like components of the catheter tip 1000 may mirror those of the catheter tips 400, 500 unless specified. For instance, similar to the catheter tips 400, 500, the catheter tip 1000 may include a body 1002 having an outer radial surface 1004 and a distal surface 106. The catheter tip 1000 includes smooth, rounded protrusions 1010 that may be positioned on and extend from the outer radial surface 1004 of the body 1002 and/or from the distal surface 1006 of the catheter tip 1000. In addition, it should be appreciated that the protrusions 1010 may be positioned along the body 1002 and/or the distal surface 1006 in any symmetrical or asymmetrical arrangement, as discussed with respect to FIGS. 6-9. Particularly, the catheter tip 1000 includes a protrusion 1010a positioned on and extending from the outer radial surface 1004 of the body 1002, a protrusion 1010b positioned on and extending from the outer radial surface 1004 of the body 1002, a protrusion 1010c positioned on and extending from the distal surface 1006, and a protrusion lOlOd positioned on and extending from the distal surface 1006.

[0050] The protrusions 1010 may be any size conducive to breaking up occlusions as described here. Particularly the protrusions 1010 may have any height and width suitable for occlusion removal. The height of the protrusions 1010 may be a maximum distance that the protrusions 1010 extend from the outer radial surface 1004 or the distal surface 1006. Specifically, the protrusion 1010a may have a width Wa and a height Ha, the protrusion 1010b may have a width Wb and a height Hb, the protrusion 1010c may have a width Wc and a height He, and the protrusion lOlOd may have a width Wd and a height Hd. In embodiments, the protrusions 1010a, 1010b, 1010c, and lOlOd may have the same widths and/or heights. In embodiments, any one of the protrusions 1010a, 1010b, 1010c, or lOlOd may have a different width and/or height than the rest of the protrusions 1010a, 1010b, 1010c, and lOlOd. In embodiments, each of the protrusions 1010a, 1010b, 1010c, and lOlOd may have different widths and/or heights. In embodiments, each of the protrusions 1010 positioned on and extending from the outer radial surface 1004 of the body 1002 may have a first height and/or width, and each of the protrusions 1010 and a second height and/or width different from the first height and/or width. For instance, the height Ha of the protrusion 1010a may be the same as the height Hb of the protrusion 1010b, the height He of the protrusion 1010c may be the same as the height Hd of the protrusion lOlOd, and the heights Ha, Hb may be different than the heights He, Hd. Similarly, the width Wa of the protrusion 1010a may be the same as the width Wb of the protrusion 1010b, the width Wc of the protrusion 1010c may be the same as the width Wd of the protrusion lOlOd, and the widths Wa, Wb may be different than the widths Wc, Wd.

[0051] In any of the above-described embodiments, the size of the protrusions 1010 may be particularly selected for use at a specific site in a subject’s vasculature and/or for use on a specific calcified lesion, as discussed in further detail below. For example, as noted above, there may be total occlusions and completely close off a vessel and partial occlusions where a portion of the vessel is still open to allow (reduced) blood flow. Larger protrusions may be more aggressive for occlusion removal while smaller protrusions may be provide a gentler approach. For example, for total occlusion crossing procedures, it may be beneficial to have smaller protrusions, such as on a tip of the catheter tip, and larger protrusions of the sides of the catheter tip for more aggressive widening of an opening through the occlusion. Additionally, smaller protrusions may be useful in procedures such as treating stent restenosis. Stent restenosis occurs when an occlusive material forms within a previously placed stent. It may be beneficial to use smaller, less aggressive protrusions to prevent unwanted damage to the placed stent while removing occlusive material.

[0052] The protrusions 1010 may also have any shape conducive for occlusion removal. That is, the protrusions 1010 may have various surface curvatures conducive for occlusion removal. In embodiments, one or more of the protrusions 1010 may take a substantially symmetrical surface curvature, such that the one or more protrusions 1010 extend from the outer radial surface 1004 of the body 1002 and/or from the distal surface 1006 of the catheter tip 1000 as semicircles. In embodiments, one or more of the protrusions 1010 may have asymmetrical surface curvatures. Referring now to FIG. 11, another embodiment of the protrusion 1010a is depicted. It should be appreciated that the discussion with respect to the protrusion 1010a may apply to any or all of the other protrusions 1010 discussed with reference to FIG. 10. The protrusion 1010a may extend from the outer radial surface 1004 of the body 1002 between a first point 1102 and a second point 1104. In other words, the distance between the first point 1102 and the second point 1104 may define the width Wa of the protrusion 1010a. The protrusion 1010a may be skewed either proximally (e.g. in the +x direction of the coordinate axes of FIG. 11) or distally (e.g. in the -x direction of the coordinate axes of FIG. 11). In other words, in embodiments where the protrusion 1010a is skewed distally, as shown in FIG. 11, a first distance DI (in the direction of the x-axis of the coordinate axes of FIG. 11) between the first point 1102 and a vertex 1106 of the protrusion 1010a may be greater than a second distance D2 (in the direction of the x- axis of the coordinate axes of FIG. 11) between the second point 1104 and the vertex 1106 of the protrusion 1010a. The vertex 1106 of the protrusion 1010a may be the point along the surface curvature of the protrusion 1010a that defines the height Ha of the protrusion 1010a from the outer radial surface 1004 of the body 1002.

[0053] As another example, in embodiments, one or more of the protrusions 1010 (FIG. 10) may have more than one local maximum height. Referring now to FIG. 12, another embodiment of the protrusion 1010a is depicted with more than one local maximum height. The protrusion 1010a includes a width Wa and a global maximum height Ha. The protrusion 1010a may include a first local maximum height Hl at a point 1202 along the surface of the protrusion 1010a and a second local maximum height H2 at a point 1204 along the surface of the protrusion 1010a. The first local maximum height Hl may be equal to or different from the second local maximum height H2. At least one of the local maximum heights Hl, H2 may be equal the global maximum height Ha. It should be appreciated that, in embodiments, the protrusion 1010a may include any number of local maximum heights. Accordingly, in some embodiments, a surface of a protrusion may undulate between multiple apexes.

[0054] Referring again to FIG. 10, in embodiments, the protrusions 1010a, 1010b, 1010c, and lOlOd may have the same shape, such as either of the shapes of the protrusion 1010a depicted in FIGS. 11 and 12. In embodiments, any one of the protrusions 1010a, 1010b, 1010c, or lOlOd may have a different shape than the rest of the protrusions 1010a, 1010b, 1010c, and lOlOd. In embodiments, each of the protrusions 1010a, 1010b, 1010c, and lOlOd may have different shapes. In embodiments, each of the protrusions 1010 positioned on and extending from the outer radial surface 1004 of the body 1002 may have a first shape, and each of the protrusions 1010 positioned on and extending from the distal surface 1006 may have a second shape different from the first shape.

[0055] In any of the above-described embodiments, the shape of the protrusions 1010 may be particularly selected for use at a specific site in a subject’s vasculature and/or for use on a specific calcified lesion, as discussed in further detail below. For example, when approaching an occlusion, it may be beneficial to approach with a sloped or ramped protrusion to more easily engage the occlusion. That is, incremental slopes on a protrusion may be less aggressive or traumatic to the occlusion or vessel, which may provide for gentler removal.

[0056] Referring now to FIG. 13, a distal end of the elongate member 120 of the catheter assembly 100 (FIG. 1) of the rotational atherectomy system 300 (FIG. 3) is depicted. The elongate member 120 may include the support catheter 130. For ease of discussion, the elongate member 120 is depicted in a cross-sectional view. The catheter tip 400 is positioned at a distal end of the elongate member 120, as discussed with reference to FIG. 4. It is noted while catheter tip 400 is illustrated, any of the catheter tips described herein could be attached to the elongate member 120.

[0057] As described above, the support catheter 130 may define an inner lumen 132 extending longitudinally therethrough (e.g. in the direction of the x-axis of the coordinate axes of FIG. 13). A drive shaft 150 may be positioned within and extend through the inner lumen 132 of the support catheter 130. For example, in embodiments, the drive shaft 150 may be a threaded wire 152 (e.g., a tightly wound metallic coil or a wire with a thread otherwise formed in it). A proximal end (e.g. in the +x direction of the coordinate axes of FIG. 13) of the drive shaft 150 (e.g., the threaded wire 152) may be drivably coupled to a rotatable motor shaft of the motor 310 (FIG. 3). A distal end (e.g. in the -x direction of the coordinate axes of FIG. 13) of the drive shaft 150 (e.g., the threaded wire 152) is coupled to catheter tip 400, such that the drive shaft 150 may rotatably drive the catheter tip 400 about the x-axis of the depicted coordinate axes relative to the support catheter 130. In embodiments, the drive shaft 150 may be coupled to the catheter tip 400 at a proximal end (e.g. in the +x direction of the coordinate axes of FIG. 13) of the body 402 of the catheter tip 400. In embodiments, the drive shaft 150 may extend at least partially through an interior of the catheter tip 400 and be coupled to an inner surface (not shown) of the body 402 of catheter tip 400. In embodiments, the drive shaft 150 may be extend at least partially through an interior of the catheter tip 400 and be embedded within the catheter tip 400 of the catheter tip 400. In embodiments, one or more welds, such as one or more spot welds, scan welds, and/or seam welds may be used to couple the catheter tip 400 to the drive shaft 150, and/or the wire 152 may be threaded onto to an interior screw threading of the body 402. In embodiments, one or more adhesives may be used to couple the catheter tip 400 to the drive shaft 150. The drive shaft 150 may rotate the catheter tip relative the support catheter 130.

[0058] In embodiments, the support catheter 130 may define a vacuum lumen 160 extending longitudinally through the support catheter 130 (e.g. in the direction of the x-axis of the coordinate axes of FIG. 13). A proximal end (e.g. in the +x direction of the coordinate axes of FIG. 13) of the vacuum lumen 160 may be coupled to a vacuum source such that vacuum may be supplied through the vacuum lumen 160 to the catheter tip 400. In embodiments, one or more aspiration vents 162 may be formed within the catheter tip 400, which are fluidically coupled to the vacuum lumen 160 of the support catheter 130. One or more of the aspiration vents 162 may be formed in the outer radial surface 404 of the body 402 of the catheter tip 400, as depicted in FIG. 13. It should, also, be appreciated that alternatively or additionally, one or more of the aspiration vents 162 may be formed in the distal surface 406 of the catheter tip 400. In operation, suction may be applied through the vacuum lumen 160 and the one or more aspiration vents 162 to remove debris in the environment of the catheter tip 400 during an atherectomy procedure, as discussed in further detail below. One or more such aspiration vents 162 may be provided on any of the catheter tips disclosed herein.

[0059] In embodiments, the support catheter 130 may define an irrigation lumen 170 extending longitudinally through the support catheter 130 (e.g. in the direction of the x-axis of the coordinate axes of FIG. 13). A proximal end (e.g. in the +x direction of the coordinate axes of FIG. 13) of the irrigation lumen 170 may be coupled to an irrigant supply, such as the injector 250 (FIG. 2). The catheter tip 400 may include one or more irrigation pores 172 fluidically coupled to the irrigation lumen 170. One or more of the irrigation pores 172 may be formed in the outer radial surface 404 of the body 402 of the catheter tip 400, as depicted in FIG. 13. It should, also, be appreciated that one or more of the irrigation pores 172 may be formed in the distal surface 406 of the catheter tip 400. In operation, irrigant (e.g., saline) supplied from an irrigant source (not shown) may be supplied through the irrigation lumen 170 and the one or more irrigation pores 172 to irrigate an anatomical area undergoing an atherectomy procedure. One or more such irrigation pores 172 may be provided on any of the catheter tips disclosed herein.

[0060] Each of the inner lumen 132, the vacuum lumen 160, the irrigation lumen 170 may be formed within the support catheter 130 may run in parallel to one another and be fluidically isolated from on another via one or more walls of the support catheter. For example, a first catheter wall 134a may separate the inner lumen 132 from the irrigation lumen 170, and a second catheter wall 134b may separate the inner lumen 132 from the vacuum lumen 160. The first and/or second catheter walls 134a, 134b may isolate the irrigation lumen 170 from the vacuum lumen 160.

[0061] Referring now to FIG. 14, a distal end of the elongate member 120 of the catheter assembly 100 (FIG. 1) of the rotational atherectomy system 300 (FIG. 3) is depicted, according to another embodiment. For ease of discussion, the elongate member 120 is depicted in a cross- sectional view. The elongate member 120, including the support catheter 130, and the catheter tip 400 may mirror those discussed with reference to FIG. 13, except where noted herein. For instance, the catheter tip 400 includes an outer radial surface 404 and a distal surface 406. The catheter tip 400 may further include one or more aspiration vents 162 and irrigation pores 172. The support catheter 130 may include the irrigation lumen 170 extending longitudinally therethrough and fluidly coupled to the one or more irrigation pores 172. It is noted while catheter tip 400 is illustrated, any of the catheter tips described herein could be attached to the elongate member 120.

[0062] As with the embodiment depicted in FIG. 13, the support catheter 130 may define the inner lumen 132. The drive shaft 150 may be positioned within and extend through the inner lumen 132 of the support catheter 130. Particularly, in embodiments, the drive shaft 150 may have an auger or helical shape 154. A proximal end (e.g. in the +x direction of the coordinate axes of FIG. 14) of the driver shaft may be drivably coupled to a rotatable motor shaft of the motor 310 (FIG. 3). A distal end (e.g. in the -x direction of the coordinate axes of FIG. 14) of the auger 154 is coupled to catheter tip 400, such that the drive shaft 150 may rotatably drive the catheter tip 400 about a longitudinal axis of the elongate element 120. In embodiments, the drive shaft 150 may be coupled to the catheter tip 400 at a proximal end (e.g. in the +x direction of the coordinate axes of FIG. 14) of the body 402 of the catheter tip 400. In embodiments, the drive shaft 150 may extend at least partially through an interior of the catheter tip 400 and be coupled to an inner surface (not shown) of the body 402 of catheter tip 400. In embodiments, the drive shaft may be extend at least partially through an interior of the catheter tip 400 and be coupled to be embedded within the body 402 of the catheter tip 400. The drive shaft 150 may rotate the catheter tip 400 relative the support catheter 130 about the x axis of the depicted coordinate axes. In embodiments, one or more welds, such as one or more spot welds, scan welds, and/or seam welds may be used to couple the catheter tip 400 to the drive shaft 150. In embodiments, one or more adhesives may be used to couple the catheter tip 400 to the drive shaft.

[0063] The drive shaft 150 having an auger or helical shape 154 may provide a dual functionality of both rotating the catheter tip 400 and providing a continuous aspiration force through the inner lumen 132 of the support catheter 130, as the rotation of the drive shaft 150 in a rotation direction creates an aspiration force, which drives fluid a proximal direction. Therefore, the inner lumen 132 of the support catheter may function as an aspiration lumen. Accordingly, the inner lumen 132 may be in fluidic communication with the aspiration vents 162. In operation, the drive shaft 150 may transport debris in the environment of the catheter tip 400 from the aspiration vents 162 proximally (e.g. in the +x direction ofthe coordinate axes ofFIG. 14) through the support catheter 130. That is, the rotation of the auger or helical shape 154 may transport debris proximally through the support catheter 130. Therefore, the catheter tip 400 need not be coupled to a separate vacuum source in order to aspirate debris through the aspiration vents 162. However, in some embodiments, a vacuum source may be fluidically couplable to the inner lumen 132 to directly deliver vacuum therethrough.

[0064] Referring now to FIG. 15, a distal end of the elongate member 120 of the catheter assembly 100 (FIG. 1) of the ultrasound-based atherectomy system 200 (FIG. 2) is depicted. The elongate member 120 may include the support catheter 130. For ease of discussion, the elongate member 120 is depicted in a cross-sectional view. The support catheter 130 may include an inner lumen 132 extending longitudinally through the body of the support catheter 130 (e.g. in the direction of the x-axis of the coordinate axes of FIG. 15). A core wire 156 may be positioned within and extend through the inner lumen 132 of the support catheter 130. A proximal end of the core wire 156 may be coupled to the ultrasound-producing mechanism of the atherectomy system 200 (FIG. 2) by a sonic connector to the ultrasound transducer 230 (FIG. 2) or an intervening sonic horn.

[0065] The catheter tip 400 is positioned at a distal end of the elongate member 120, as discussed with reference to FIG. 4. Accordingly, in embodiments, the catheter tip 400 is positioned at a distal end of the core wire 156 such that the core wire 156 may propagate ultrasonic vibrations to the catheter tip 400. As previously discussed, the catheter tip 400 includes the body 402 having an outer radial surface 404 and a distal surface 406. It is noted while catheter tip 400 is illustrated, any of the catheter tips described herein could be attached to the elongate member 120. Accordingly, this and the below description may be applicable to the various catheter tip embodiments described herein.

[0066] The catheter tip 400 may be coupled to the distal end of the core wire 156. In embodiments, the catheter tip 400 may be coupled to the distal end of the core wire 156 by a clearance fit, a transition fit, or an interference fit between the catheter tip 400 and the core wire 156. The clearance fit is a fairly loose fit that enables the core wire 156 to freely rotate or slide within the catheter tip 400, the transition fit firmly holds the core wire 156 in place within the catheter tip 400, but not so firmly that the core wire 156 cannot be removed from the catheter tip 400, and the interference fit securely holds the core wire 156 in place within the catheter tip 400 such that the core wire 156 cannot be removed from the catheter tip 400 without damaging the core wire 156 or catheter tip 400. In embodiments, one or more welds, such as one or more spot welds, scan welds, and/or seam welds may be used to couple the catheter tip 400 to the core wire 156. In embodiments, one or more adhesives may be used to couple the catheter tip 400 to the core wire 156. In embodiments, the core wire 156 may be coupled to the catheter tip 400 at a proximal end (e.g. in the +x direction of the coordinate axes of FIG. 14) of the body 402 of the catheter tip 400. In embodiments, the core wire 156 may be extend at least partially through an interior of the catheter tip 400 and be embedded within the body 402 of catheter tip 400. In embodiments, the core wire 156 may be extend at least partially through an interior of the catheter tip 400 and be coupled to an inner surface (not shown) of the catheter tip 400.

[0067] A working length of a distal portion of the core wire 156 extends beyond the support catheter 130 and can be configured for displacement to effect lesion modification. Particularly, transmission of mechanical vibrations through the core wire 156 may result in displacement of the distal portion of the core wire 156. Displacement of the distal portion of the core wire 156 in turn results in displacement of the catheter tip 400 coupled to the core wire 156. The displacement may be longitudinal, transverse, or longitudinal and transverse in accordance with a profile of the core wire 156 and the vibrational energy transmitted therethrough. The working length of the core wire 156 beyond the support catheter 130 may be between 5 and 200 mm, between 5 and 100 mm, or between 100 and 200 mm.

[0068] In embodiments, the core wire 156 may define an irrigation lumen 170 extending longitudinally the core wire 156 (e.g. in the direction of the x-axis of the coordinate axes of FIG. 15). A proximal end (e.g. in the +x direction of the coordinate axes of FIG. 15) of the irrigation lumen 170 may be coupled to an irrigant supply, such as the injector 250 (FIG. 2). The irrigation lumen 170 may extend at least partially through the catheter tip 400. The catheter tip 400 may include one or more irrigation pores 172 fluidly coupled to the irrigation lumen 170. One or more of the irrigation pores 172 may be formed in the outer radial surface 404 of the body 402 of the catheter tip 400, as depicted in FIG. 15. It should, also, be appreciated that one or more of the irrigation pores 172 may be formed in the distal surface 406 of the catheter tip 400. In operation, irrigant may be supplied through the irrigation lumen 170 and the one or more irrigation pores 172 to irrigate an anatomical area undergoing an atherectomy procedure, as is known in the art.

[0069] Referring now to FIG. 16, a cross-sectional view of a blood vessel 1600 is depicted. The blood vessel 1600 includes a blood vessel wall 1620 and an internal lumen 1602. The internal lumen 1602 may be defined between the endothelium 1622 of the vessel wall 1620. The vessel wall 1620 further includes a tunica intima 1608 between the endothelium 1622 and the internal elastic membrane of the vessel wall 1620. The vessel wall 1620 further includes a tunica media 1606 that may be between the internal elastic membrane of the vessel wall 1620 and the external elastic membrane of the vessel wall 1620. The vessel wall 1620 further includes a tunica externa 1604 forming the outermost layer of the vessel wall 1620. The blood vessel 1600 includes an internal lesion 1614 within the internal lumen 1602, an intimal lesion 1612 within the tunica intima 1608, and a medial lesion 1610 within the tunica media 1606.

[0070] Reference will now be made with reference to FIGS. 4 and 16 in conjunction with FIG. 17, which depicts the distal end of the elongate member 120 of the catheter assembly 100 (FIG. 1), with the catheter tip 400 is positioned at a distal end thereof, breaking calcified lesions. The catheter assembly 100 (FIG. 1) may be incorporated in the ultrasound-based atherectomy system 200 (FIG. 2) or the rotational atherectomy system 300 (FIG. 3). It is noted while catheter tip 400 is illustrated, any of the catheter tips described herein could be attached to the elongate member 120.

[0071] In operation, a user may manipulate the catheter assembly 100 (FIG. 1) at the hand piece 110 (FIG. 1), for instance, to direct the catheter tip 400 positioned at the distal end of the elongate member 120 through the vasculature of a subject to a site in the blood vessel 1600 including a lesion. It should be appreciated that the catheter tip 400 may include a lumen passing therethrough to allow the catheter tip 400 and catheter assembly 100 to be advanced over a guidewire. The size of the catheter tip 400, the positioning of the protrusions, the placement of the protrusions 410 on the catheter tip 400, and the size and/or shape of the protrusions 410 may all be particularly selected for use in the blood vessel 1600, and more particularly for use to break the lesions 1614, 1612, and 1610 in the blood vessel. That is, the catheter tip 400 may be particularly designed based on whether the blood vessel 1600 includes an internal lesion, an intimal lesion, and/or a medial lesion, and based on the specific qualities of each such lesion, such as the size, mass, and density of the calcified lesions. Additionally, the inclusion and use of irrigation pores and/or aspiration vents with the catheter tip 400 may further be selected based on the particular blood vessel 1600 and lesions 1614, 1612, and 1610 a user wishes to break.

[0072] After the catheter tip 400 is positioned at the site in the blood vessel 1600 including a lesion, a user may activate the catheter tip 400 to abrade or break up the calcified lesion. For instance, in embodiments, where the elongate member 120 and catheter tip 400 are incorporated in the rotational atherectomy system 300 (FIG. 3), a user may rotatably drive the drive shaft 150 (FIGS. 13, 14), thereby rotatably driving the catheter tip 400 at high speeds (e.g., 20,000-160,000 rpm). Similarly, in embodiments, where the elongate member 120 and catheter tip 400 are incorporated in the ultrasound-based atherectomy system 200 (FIG. 2), a user may activate the ultrasound-based atherectomy system 200 (FIG. 2) to transmit mechanical vibrations through the core wire 156 (FIG. 15) to displace the catheter tip 400 coupled to the core wire 156 longitudinally, transversely, or longitudinally and transversely. Therefore, in embodiments, activating the catheter tip 400 may include rotating the catheter tip 400 and/or vibrationally displacing the catheter tip 400.

[0073] Activating the catheter tip 400 may break up the internal calcified lesion 1614 within the internal lumen 1602, as shown in FIG. 17. Activating the catheter tip 400 may, also bring the catheter tip 400 into contact with the endothelium 1622 of the blood vessel 1600. Particularly, the catheter tip 400 may be activated at such high speeds or frequencies that when the catheter tip 400, and particularly the protrusions 410 of the catheter tip 400, is brought into contact with the endothelium, the protrusions 410 of the catheter tip 400 apply sufficient force to break up the intimal lesion 1612 within the tunica intima 1608 and the medial lesion 1610 within the tunica media 1606. Because the protrusions 410 are smooth and rounded, as described above, the protrusions 410 do not damage the soft tissue of the vessel wall 1620 of the blood vessel 1600, including, but not limited to, the endothelium 1622, the internal elastic membrane, the external elastic membrane, and the tunica externa 1604. It should further be appreciated that before, during, and/or after activation of the catheter tip 400, aspiration and/or irrigation may be supplied through the catheter tip 400, as described with reference to FIGS. 13-15. Aspiration may be particularly supplied to remove the smaller particles of the broken lesions 1614, 1612, and 1610 from the subject’s anatomy.

[0074] Embodiments can be described with reference to the following numerical clause:

[0075] 1. A device for atherectomy comprising a catheter tip, comprising: a body; and a plurality of smooth, rounded protrusions extending radially from the body, wherein the body and the plurality of smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel.

[0076] 2. The device of clause 1, wherein the catheter tip is coupled to a drive shaft coupled to a rotational motor. [0077] 3. The device of any preceding clause, wherein the catheter tip is configured to be rotatably driven up to a rate of rotation of 160,000 rpm via the drive shaft.

[0078] 4. The device of any preceding clause, wherein: the catheter tip is coupled to a core wire; and the core wire is configured to transmit mechanical vibrations from an ultrasound transducer to longitudinally displace the catheter tip in the vessel.

[0079] 5. The device of any preceding clause, wherein the smooth, rounded protrusions are symmetrically positioned along the body.

[0080] 6. The device of any preceding clause, wherein the smooth, rounded protrusions are asymmetrically positioned along the body.

[0081] 7. The device of any preceding clause, wherein: the body comprises a flat distal surface orientated perpendicular to a longitudinal axis of the body, and one or more of the smooth, rounded protrusions are positioned on the flat distal surface.

[0082] 8. The device of clause 7, wherein: the distal surface is a flat distal surface oriented perpendicular to a longitudinal axis of the body; or the distal surface is a rounded surface concentrically located on a longitudinal axis of the body.

[0083] 9. The device for atherectomy of any preceding clause, wherein the catheter tip is formed of tungsten or titanium.

[0084] 10. The device of any preceding clause, wherein: a first smooth, rounded protrusion extends a first distance from a surface of the catheter tip; and a second smooth, rounded protrusion extends a second distance from the surface of the catheter tip the second distance different from the first distance.

[0085] 11. The device of any preceding clause, wherein each of the smooth, rounded protrusions extends a first distance from a respective surface of the catheter tip.

[0086] 12. The device of any preceding clause, wherein the catheter tip comprises one or more aspiration vents.

[0087] 13. The device of any preceding clause, wherein the catheter tip comprises one or more irrigation pores configured to be fluidically coupled to an irrigant source.

[0088] 14. A catheter assembly for atherectomy, comprising: an elongate member; and a catheter tip positioned at a distal end of the elongate member, wherein: the catheter tip comprises a body and a plurality of smooth, rounded protrusions extending from the body; and the body and the smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel.

[0089] 15. The catheter assembly of clause 14, wherein: the elongate member comprises a drive shaft configured to be rotationally driven, and the catheter tip is coupled to the drive shaft.

[0090] 16. The catheter assembly of any preceding clause, wherein the catheter tip is configured to be rotatably driven up to a rate of rotation of 160,000 rpm by the drive shaft.

[0091] 17. The catheter assembly of any preceding clause, wherein: the elongate member comprises a core wire coupled to the catheter tip, and the core wire is configured to transmit mechanical vibrations from an ultrasound transducer to longitudinally displace the catheter tip in the vessel.

[0092] 18. The catheter assembly of any preceding clause, wherein the smooth, rounded protrusions are symmetrically positioned along the body.

[0093] 19. The catheter assembly of any preceding clause, wherein the body comprises a flat distal surface orientated perpendicular to a longitudinal axis of the body, and one or more of the smooth, rounded protrusions are positioned on the flat distal surface.

[0094] 20. The catheter assembly of any preceding clause, wherein: the distal surface is a flat distal surface oriented perpendicular to a longitudinal axis of the body; or the distal surface is a rounded surface concentrically located on a longitudinal axis of the body.

[0095] 21. The catheter assembly of any preceding clause, wherein the catheter tip is formed of tungsten or titanium.

[0096] 22. The catheter assembly of any preceding clause, wherein: a first smooth, rounded protrusion extends a first distance from a surface of the catheter tip; and a second smooth, rounded protrusion extends a second distance from the surface of the catheter tip the second distance different from the first distance.

[0097] 23. The catheter assembly of any preceding clause, wherein each of the smooth, rounded protrusions extends a first distance from a respective surface of the catheter tip.

[0098] 24. The catheter assembly of any preceding clause, wherein the catheter tip comprises one or more aspiration vents.

[0099] 25. The catheter assembly of any preceding clause, wherein the catheter tip comprises one or more irrigation pores configured to be fluidically coupled to an irrigant source. [00100] 26. The catheter assembly of any preceding clause, further comprising: an ultrasound generator; and an ultrasound transducer operatively coupled to the ultrasound generator and the catheter tip for generating vibrations within the catheter tip.

[00101] 27. A method of breaking occlusions, comprising: advancing a catheter assembly to a position in a vessel, wherein the catheter assembly comprises: an elongate member; and a catheter tip positioned at a distal end of the elongate member, wherein the catheter tip comprises a body and a plurality of smooth, rounded protrusions extending from the body; and activating the catheter tip to break up an occlusion with the catheter tip, wherein the catheter tip is rotated or vibrated at a frequency sufficient to break up the occlusion in the vessel.

[00102] 28. The method of clause 27, wherein: the elongate member comprises a drive shaft extending coupled to the catheter tip, and activating the catheter tip further comprises rotatably driving the catheter tip via the drive shaft.

[00103] 29. The method of any preceding clause, wherein: the elongate member comprises a core wire coupled to the catheter tip, and activating the catheter tip further comprises displacing the catheter tip in the vessel via mechanical vibrations transmitted through the core wire.

[00104] 30. The method of any preceding clause, further comprising applying aspiration to the position in the vessel through an aspiration vent of the catheter tip.

[00105] 31. The method of any preceding clause, further comprising irrigating the position in the vessel through an irrigation pore of the catheter tip.

[00106] It should now be understood that embodiments of the present disclosure are directed to catheter tips that include smooth, rounded protrusions extending from the catheter tip. The smooth, rounded protrusions are configured to break calcified lesions medial and intimal in a vessel without damaging soft tissue. The rounded protrusions may decrease the contacting surface area of the catheter tip that may contact a vessel wall. Moreover, in being smooth, or void of sharp edges or rough surface modifications, such as a diamond coating, the protrusions may impart sufficient force against a vessel wall to break the lesions located in the medial and intimal layers of the vessel without damaging the soft tissue of the vessel wall.

[00107] It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[00108] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

Claims

1. A device for atherectomy, comprising: a catheter tip, comprising: a body; and a plurality of smooth, rounded protrusions extending radially from the body, wherein the body and the plurality of smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel without damaging soft tissue.

2. The device of claim 1, wherein the catheter tip is coupled to a drive shaft coupled to a rotational motor.

3. The device of claim 2, wherein the catheter tip is configured to be rotatably driven up to a rate of rotation of 160,000 rpm via the drive shaft.

4. The device of claim 1, wherein: the catheter tip is coupled to a core wire; and the core wire is configured to transmit mechanical vibrations from an ultrasound transducer to longitudinally displace the catheter tip in the vessel.

5. The device of claim 1, wherein the smooth, rounded protrusions are symmetrically positioned along the body.

6. The device of claim 1, wherein the smooth, rounded protrusions are symmetrically positioned along the body.

7. The device for atherectomy of claim 1, wherein: the body comprises a distal surface, and one or more of the smooth, rounded protrusions are positioned on the distal surface.

8. The device for atherectomy of claim 6, wherein: the distal surface is a flat distal surface oriented perpendicular to a longitudinal axis of the body; or the distal surface is a rounded surface concentrically located on a longitudinal axis of the body.

9. The device of claim 1, wherein the catheter tip is formed of tungsten or titanium.

10. The device of claim 1, wherein: a first smooth, rounded protrusion extends a first distance from a surface of the catheter tip; and a second smooth, rounded protrusion extends a second distance from the surface of the catheter tip the second distance different from the first distance.

11. The device of claim 1 , wherein each of the smooth, rounded protrusions extends a first distance from a respective surface of the catheter tip.

12. The device of claim 1, wherein the catheter tip comprises one or more aspiration vents.

13. The device of claim 1, wherein the catheter tip comprises one or more irrigation pores configured to be fluidically coupled to an irrigant source.

14. A catheter assembly for atherectomy, comprising: an elongate member; and a catheter tip positioned at a distal end of the elongate member, wherein: the catheter tip comprises a body and a plurality of smooth, rounded protrusions extending from the body; and the body and the smooth, rounded protrusions are configured to be vibrated or rotated at a frequency sufficient to break-up occlusions in a vessel.

15. The catheter assembly of claim 14, wherein: the elongate member comprises a drive shaft configured to be rotationally driven, and the catheter tip is coupled to the drive shaft.

16. The catheter assembly of claim 15, wherein the catheter tip is configured to be rotatably driven up to a rate of rotation of 160,000 rpm by the drive shaft.

17. The catheter assembly of claim 14, wherein: the elongate member comprises a core wire coupled to the catheter tip, and the core wire is configured to transmit mechanical vibrations from an ultrasound transducer to longitudinally displace the catheter tip in the vessel.

18. The catheter assembly of claim 14, wherein the smooth, rounded protrusions are symmetrically positioned along the body.

19. The catheter assembly of claim 14, wherein: the body comprises a distal surface, and one or more of the smooth, rounded protrusions are positioned on the distal surface.

20. The catheter assembly of claim 14, wherein: the distal surface is a flat distal surface oriented perpendicular to a longitudinal axis of the body; or the distal surface is a rounded surface concentrically located on a longitudinal axis of the body.

21. The catheter assembly of claim 14, wherein the catheter tip is formed of tungsten or titanium.

22. The catheter assembly of claim 14, wherein: a first smooth, rounded protrusion extends a first distance from a surface of the catheter tip; and a second smooth, rounded protrusion extends a second distance from the surface of the catheter tip the second distance different from the first distance.

23. The catheter assembly of claim 14, wherein each of the smooth, rounded protrusions extends a first distance from a respective surface of the catheter tip.

24. The catheter assembly of claim 14, wherein the catheter tip comprises one or more aspiration vents.

25. The catheter assembly of claim 14, wherein the catheter tip comprises one or more irrigation pores configured to be fluidically coupled to an irrigant source.

26. The catheter assembly of claim 14, further comprising: an ultrasound generator; and an ultrasound transducer operatively coupled to the ultrasound generator and the catheter tip for generating vibrations within the catheter tip.

27. A method of breaking occlusions, comprising: advancing a catheter assembly to a position in a vessel, wherein the catheter assembly comprises: an elongate member; and a catheter tip positioned at a distal end of the elongate member, wherein the catheter tip comprises a body and a plurality of smooth, rounded protrusions extending from the body; and activating the catheter tip to break up an occlusion with the catheter tip, wherein the catheter tip is rotated or vibrated at a frequency sufficient to break up the occlusion in the vessel without damaging soft tissue.

28. The method of claim 27, wherein: the elongate member comprises a drive shaft extending coupled to the catheter tip, and activating the catheter tip further comprises rotatably driving the catheter tip via the drive shaft.

29. The method of claim 27, wherein: the elongate member comprises a core wire coupled to the catheter tip, and activating the catheter tip further comprises displacing the catheter tip in the vessel via mechanical vibrations transmitted through the core wire.

30. The method of claim 27, further comprising applying aspiration to the position in the vessel through an aspiration vent of the catheter tip.

31. The method of claim 27, further comprising irrigating the position in the vessel through an irrigation pore of the catheter tip.