Lithotripsy conduit

Abstract

Methods and systems for decomposing endovascular lesions are disclosed herein. An illustrative method may include advancing a catheter through a vasculature to a target location. The catheter may be a catheter shaft, an expandable member secured to a distal portion of the catheter shaft, and one or more ultrasound transducers. The method may also include activating the ultrasound transducer to emit an ultrasound field directed toward the target location.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 400,167, filed on August 23, 2022, the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to catheters having internal lithotripsy emitters. More particularly, the present invention relates to angioplasty devices for modifying lesion compliance. Background Art

[0004] Many patients suffer from occluded arteries and other blood vessels that restrict blood flow. The occlusion can be a partial occlusion, which reduces blood flow through the occluded portion of the blood vessel, or a complete occlusion (e.g., chronic total occlusion), which substantially blocks blood flow through the occluded vessel. Occluded, stenotic, or narrowed blood vessels can be treated with many relatively non-invasive medical procedures, including percutaneous transluminal angioplasty (PTA), percutaneous transluminal coronary angioplasty (PTCA), atherectomy, and lithotripsy. However, for eccentric calcified lesions, the efficacy of intravascular lithotripsy may be reduced. Each of the known medical devices, systems, and methods has certain advantages and disadvantages. There is a need to provide alternative medical devices and systems, including devices and systems for treating occluded or calcified lesions. Summary of the invention

[0005] The present invention relates to several alternative designs, materials and methods of manufacturing medical device structures and components.

[0006] In a first example, a method for decomposing an intravascular lesion may include advancing a catheter through a vascular system to a target location and activating one or more ultrasound transducers to emit an ultrasound field directed toward the target location. The catheter may include a catheter shaft, an expandable member fixed to a distal portion of the catheter shaft, and one or more ultrasound transducers.

[0007] Alternatively or additionally to any of the above examples, in another example, the catheter can further include a guidewire extending through the lumen of the catheter shaft.

[0008] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasonic transducers can be coupled to the expandable member.

[0009] Alternatively or additionally to any of the above examples, in another example, the catheter shaft can include an outer tubular member and an inner tubular member.

[0010] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasonic transducers can be coupled to the inner tubular member.

[0011] Alternatively or additionally to any of the above examples, in another example, the expandable member can include an inflatable balloon.

[0012] Alternatively or additionally to any of the above examples, in another example, the expandable member can include an expandable basket.

[0013] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include two or more lobe parts.

[0014] Alternatively or additionally to any of the above examples, in another example, the expandable basket may further include one or more sliding rings positioned between and coupled to the two or more circular protrusions.

[0015] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include one or more longitudinally extending struts.

[0016] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include helically extending struts.

[0017] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include a woven structure.

[0018] Alternatively or additionally to any of the above examples, in another example, one or more ultrasound transducers may be arranged in one or more arrays.

[0019] Alternatively or additionally to any of the above examples, in another example, the ultrasound field may be emitted radially from the catheter.

[0020] Alternatively or additionally to any of the above examples, in another example, the ultrasound field can be emitted in a direction parallel to the longitudinal axis of the catheter shaft.

[0021] In another example, a method for decomposing an intravascular lesion may include advancing a catheter through a vascular system to a target location and activating one or more ultrasound transducers to emit an ultrasound field directed toward the target location. The catheter may include a catheter shaft including an outer tubular member and an inner tubular member; an inflatable balloon secured to a distal portion of the catheter shaft; and one or more ultrasound transducers.

[0022] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasound transducers can be coupled to the inflatable balloon.

[0023] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasonic transducers can be coupled to the inner tubular member.

[0024] Alternatively or additionally to any of the above examples, in another example, the ultrasound field may be emitted radially from the catheter.

[0025] Alternatively or additionally to any of the above examples, in another example, the ultrasound field can be emitted in a direction parallel to the longitudinal axis of the catheter shaft.

[0026] In another example, a method for decomposing an intravascular lesion may include advancing a catheter through a vascular system to a target location and activating one or more ultrasound transducers to emit an ultrasound field directed toward the target location. The catheter may include a catheter shaft including an outer tubular member and an inner tubular member; an expandable basket secured to a distal portion of the catheter shaft; and one or more ultrasound transducers.

[0027] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasonic transducers can be coupled to the expandable basket.

[0028] Alternatively or additionally to any of the above examples, in another example, at least one of the one or more ultrasonic transducers can be coupled to the inner tubular member.

[0029] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include two or more lobe parts.

[0030] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include one or more longitudinally extending struts.

[0031] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include helically extending struts.

[0032] Alternatively or additionally to any of the above examples, in another example, the expandable basket can include a braided structure.

[0033] The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention may be more fully understood by considering the following detailed description of various embodiments in conjunction with the accompanying drawings, in which:

[0035] Figure 1 is a side view of an illustrative lithotripsy balloon catheter positioned in a blood vessel;

[0036] Figure 2 is a side view of another illustrative lithotripsy balloon catheter;

[0037] Figure 3 is a side view of an illustrative lithotripsy catheter positioned in a blood vessel;

[0038] Figure 4 is a side view of an illustrative lithotripsy guidewire positioned in a blood vessel;

[0039] Figure 5 is a side view of an illustrative expandable frame lithotripsy catheter disposed in a blood vessel;

[0040] Figure 6 is a side view of another illustrative expandable frame lithotripsy catheter disposed in a blood vessel;

[0041] Figure 7 is a side view of another illustrative expandable frame lithotripsy catheter disposed in a blood vessel;

[0042] Figure 8 is a side view of another illustrative expandable frame lithotripsy catheter disposed in a blood vessel; and

[0043] Fig. 9 is a side view of another illustrative expandable frame lithotripsy catheter disposed in a blood vessel.

[0044] Although the present invention is suitable for various modifications and alternative forms, its specific details have been shown in the drawings by way of example and will be described in more detail. However, it should be understood that the present invention is not intended to limit the various aspects of the present invention to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention. DETAILED DESCRIPTION

[0045] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in the specification.

[0046] All numerical values ​​are assumed herein to be modified by the term "about", whether or not expressly indicated otherwise. The term "about" generally refers to a range of numbers that one skilled in the art would consider equivalent to the cited number (i.e., having the same function or result). In many cases, the term "about" may indicate that the number is rounded to the nearest significant figure.

[0047] Numerical ranges recited by endpoints include all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0048] Although some suitable sizes, ranges and / or values ​​are disclosed for various components, features and / or specifications, those skilled in the art to which the present invention relates will understand that the desired sizes, ranges and / or values ​​may be derived from those explicitly disclosed.

[0049] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in a sense including "and / or" unless the content clearly dictates otherwise.

[0050] The following detailed description should be read with reference to the accompanying drawings, in which similar elements in different drawings have the same numbering. The specific embodiments and the drawings, which are not necessarily drawn to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. The illustrative embodiments depicted are exemplary only. Unless expressly stated to the contrary, selected features of any illustrative embodiment may be incorporated into additional embodiments.

[0051] Many patients suffer from arterial occlusions, other vascular occlusions, and / or occlusions of ducts or other body lumens, which may restrict the flow of body fluids (e.g., blood, bile, etc.). The occlusion may be a partial occlusion, which reduces blood flow through the occluded portion of the vessel, or a complete occlusion (e.g., a chronic total occlusion), which substantially blocks blood flow through the occluded vessel. Revascularization techniques include the use of various devices to traverse the occlusion to create or enlarge an opening through the occlusion. In some cases, lesions, such as calcified lesions, may present problems for revascularization techniques, and it may be beneficial to treat the calcified lesions in order to modify their compliance to enable full dilation prior to stent placement.

[0052] In some cases, for example, ultrasound can be used to treat vascular lesions at various stages of disease progression, such as fibrotic and calcified lesions, ranging from soft plaques to severely calcified lesions. Vascular lesions that may be suitable for treatment with ultrasound-based devices include irregular, severely calcified plaques located within and adjacent to the vessel wall, and lesions that are more or less rigid and therefore may be susceptible to failure due to mechanical fatigue. For example, sound-based devices can be used to generate standing wave pressure patterns within the thickness of the lesion, generate bending moments at the ends of the lesion, and / or generate resonance along the length of the lesion. In some cases, the high-frequency mechanical action of ultrasound can also effectively treat vascular lesions in early states, including fibrosis and soft plaques. In some cases, ultrasound devices can apply unfocused near-field ultrasound therapy to treat vascular lesions. Although the device or system described herein is described in relation to vascular lesions, it should be understood that the device or system can also be used in other applications, such as, but not limited to, peripheral calcified lesions, aortic valves, mitral valves, or non-vascular applications including tumor treatment. For example, the methods and systems described herein may be used in any vessel that includes or is adjacent to a target treatment site, such as, but not limited to, vascular lesions, peripheral lesions, tumors, and the like.

[0053] Figure 1 1 is a side view of an illustrative catheter 10 that can be used to treat a lesion disposed in a blood vessel 12 and positioned adjacent to an intravascular lesion 14. The catheter 10 can be configured to emit shock waves or an ultrasonic field. The catheter 10 can include a balloon 16 coupled to a catheter shaft 18. Typically, the catheter 10 can be advanced over a guidewire 22, through a vascular system, to a target area with the balloon 16 in a collapsed or expanded configuration. Once positioned at a target location in the vascular system, the balloon 16 can be inflated to apply a radially outward force to the lesion 14. The target area can be located in any suitable peripheral or cardiac vascular lumen location.

[0054] The balloon 16 can be made of typical angioplasty balloon materials, including polymers such as polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), polybutylene terephthalate (PBT), polyurethane, polyvinyl chloride (PVC), polyether ester, polyester, polyamide, elastomeric polyamide, polyether block amide (PEBA), and other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof, etc. The balloon 16 can be compliant, semi-compliant, or non-compliant as desired. In some embodiments, the balloon 16 can be a high-pressure balloon.

[0055] The shaft 18 can be a catheter shaft, similar to a typical catheter shaft. For example, the catheter shaft 18 can include an outer tubular member 26 and an inner tubular member 24 extending through at least a portion of the outer tubular member 26. The inner tubular member 24 and the outer tubular member 26 can be made of a variety of different materials. For example, the inner tubular member 24 and the outer tubular member 26 can be made of metal, metal alloys, polymers, metal-polymer composites, or any other suitable material.

[0056] The outer tubular member 26 can extend proximally from the distal region 42 to a proximal end configured to remain outside the patient's body. The inner tubular member 24 can extend proximally from the distal region 44 to a proximal end configured to remain outside the patient's body. Although not shown, the proximal ends of the inner tubular member 24 and / or the outer tubular member 26 can include a hub attached thereto for connecting other treatment devices or providing a port for facilitating other treatments. It is contemplated that the stiffness of the inner tubular member 24 and / or the outer tubular member 26 can be modified to form a catheter 10 for use in various vessel diameters and various locations within the vascular tree.

[0057] The inner tubular member 24 and the outer tubular member 26 can be arranged in any suitable manner. For example, in some embodiments, the inner tubular member 24 can be coaxially disposed within the outer tubular member 26. According to these embodiments, the inner tubular member 24 and the outer tubular member 26 may or may not be fixed to each other along the substantially longitudinal axis of the catheter shaft 18. Alternatively, the inner tubular member 24 can be disposed along the inner wall, or otherwise adjacent to the inner wall of the outer tubular member 26. In other embodiments, the inner tubular member 24 and the outer tubular member 26 can be arranged in another desired manner. In some embodiments, the inner tubular member 24 and / or the outer tubular member 26 can be twistable to facilitate rotation of the device 10. The inner tubular member 24 and / or the outer tubular member 26 can include an embedded reinforcing member, such as, but not limited to, an embedded coil or braided member.

[0058] The inner tubular member 24 may include an inner lumen 30. In at least some embodiments, the inner lumen 30 is a guidewire lumen for receiving a guidewire 22 therethrough. Thus, the catheter 10 may be advanced to a desired position over the guidewire 22. The guidewire lumen 30 may extend substantially along the entire length of the catheter shaft 18, such that the catheter 10 is similar to a conventional "over-the-wire" catheter. Alternatively, the guidewire lumen 30 may extend only along a portion of the catheter shaft 18, such that the catheter 10 is similar to a "single operator exchange" or "rapid exchange" catheter.

[0059] The catheter shaft 18 can also include an inflation lumen 32, which can be used, for example, to deliver an inflation medium to and from the balloon 16 to selectively inflate and / or deflate the balloon 16. The location and position of the inflation lumen 32 can vary depending on the configuration of the inner tubular member 24 and the outer tubular member 26. For example, when the outer tubular member 26 surrounds the inner tubular member 24, the inflation lumen 32 can be defined in the space between the outer tubular member 26 and the inner tubular member 24. In embodiments where the outer tubular member 26 is disposed alongside the inner tubular member 24, the inflation lumen 32 can be a lumen of the outer tubular member 26.

[0060] The balloon 16 can be coupled to the catheter shaft 18 in any of a variety of suitable ways. For example, the balloon 16 can be glued or heat bonded to the catheter shaft 18. In some embodiments, the proximal waist 34 of the balloon 16 can be bonded to the catheter shaft 18, such as to the distal region 42 of the outer tubular member 26, and the distal waist 36 of the balloon 16 can be bonded to the catheter shaft 18, such as to the distal region 44 of the inner tubular member 24. However, the exact bonding locations may vary. It is also contemplated that the balloon 16 can take other shapes as desired. For example, the balloon 16 can include more than one chamber or circular protrusion.

[0061] One or more ultrasonic transducers or transmitters 38a-i (collectively referred to as 38) can be coupled to the balloon 16. The ultrasonic transducer 38 can be glued, bonded, adhered, etc. to the balloon 16. The balloon 16 can include any desired number of ultrasonic transducers 38, such as, but not limited to, one, two, three, four, five, ten, twenty or more, etc. One or more ultrasonic transducers 38 can be coupled to the outer surface of the balloon 16. Alternatively or additionally, one or more ultrasonic transducers 38 can be coupled to the inner surface of the balloon 16. It is conceivable that positioning the ultrasonic transducer 38 on the balloon 16 can bring the ultrasonic transducer closer to the lesion 14 for targeted and / or localized therapy. Ultrasound waves 46 can be transmitted through the vessel wall 12. In some cases, one or more ultrasonic transducers 38 can include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. One or more ultrasonic transducers 38 can be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The one or more ultrasonic transducers 38 may be a single ultrasonic transducer, or the one or more ultrasonic transducers 38 may include a series of ultrasonic transducers that can be operated to effectively function as a single ultrasonic transducer to provide the desired acoustic pressure over the desired treatment area. It is also contemplated that each ultrasonic transducer 38 can be operated independently of the other ultrasonic transducers 38. The applied acoustic pressure can range from tens of kilopascals (kPa) to over ten megapascals (MPa).

[0062] The one or more ultrasonic transducers 38 may be arranged in any desired configuration. In some examples, the ultrasonic transducers 38 may be staggered around the circumference and / or length of the balloon 16 so that a maximum number of ultrasonic transducers 38 may be positioned on the balloon 16. In another example, as shown in FIG. Figure 1 As shown, one or more ultrasonic transducers 38 can be arranged in linear arrays 40a, 40b, 40c (collectively referred to as 40), wherein each array 40 extends generally parallel to the longitudinal axis of the catheter shaft 18. For example, a first plurality of ultrasonic transducers 38a, 38b, 38c can form a first array 40a, a second plurality of ultrasonic transducers 38d, 38e, 38f can form a second array 40b, and a third plurality of ultrasonic transducers 38g, 38h, 38i can form a third array 40c. The arrays 40 can be spaced evenly or eccentrically around the circumference of the balloon 16. Figure 1 In the illustrated embodiment, each array 40 is spaced approximately 90° from an adjacent array 40. However, this is not required. The spacing may be determined in part by the number of arrays 40 on the balloon 16. In addition, the arrays do not need to be evenly spaced. In some examples, one or more ultrasonic transducers 38 may be arranged as a circumferentially extending array, wherein each array extends around the circumference of the balloon 16. In other embodiments, one or more ultrasonic transducers 38 may be arranged along the balloon 16 in a spiral manner. For example, the ultrasonic transducer 38 may be spaced longitudinally and circumferentially from each adjacent ultrasonic transducer 38. These are just some examples. It should be understood that one or more ultrasonic transducers 38 may be positioned in any arrangement as desired. In some embodiments, each array 40 may function independently of other arrays, or the arrays 40 may operate together to effectively function as a single ultrasonic transducer.

[0063] Each of the one or more ultrasonic transducers 38 can generate an ultrasonic field 46 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 14. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 38, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 38, wherein the acoustic pressure wave emitted by the ultrasonic transducer 38 is not focused and can be controlled to be substantially uniform on the calcified lesion 14. The ultrasonic transducer 38 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. In other embodiments, the ultrasonic transducer 38 can be configured to emit ultrasonic waves in a single direction. For example, the ultrasonic transducer 38 can be configured to emit ultrasonic waves in a direction radially outward from the balloon 16. When two or more ultrasonic transducers 38 are provided, the ultrasonic transducers 38 can be arranged to emit ultrasonic waves in different radial and / or axial directions, but this is not required.

[0064] In some cases, for example, the ultrasonic transducer 38 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 14. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 38 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm when measured from a central axis extending through the catheter shaft 18. Multiple ultrasonic transducers 38 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0065] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 38 can be many times greater than the diameter of the inner tubular member 24 and / or the outer tubular member 26. In some cases, the length of the ultrasonic transducer 38 can be at least as long as the length of the calcified lesion 14 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. As described above, the ultrasonic transducer 38 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in such a way as to effectively act as a single ultrasonic transducer. The ultrasonic transducer 38 can be electrically coupled to an electronic source (not explicitly shown) via one or more wires 48. In some cases, two or more ultrasonic transducers can be coupled to a single electronic source and driven and output at the same frequency. In other embodiments, two or more ultrasonic transducers can be coupled to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 14.

[0066] The balloon 16 can be inflated using any suitable inflation fluid. Example inflation fluids can include, but are not limited to, water, saline (e.g., 0.9% sodium chloride), a mixture of saline and a radiopaque contrast agent (e.g., a 50 / 50 mixture), and the like. In some cases, the inflation fluid can be selected for the manner in which acoustic pressure is transmitted through the inflation fluid. It should be appreciated that by selecting a particular fluid for inflating the balloon 16, one can control the efficiency of acoustic energy transmission through the fluid and to the calcified lesion 14. In one example, the inflation fluid can be selected to have an acoustic impedance of a particular characteristic to serve as an acoustic match between the ultrasound transducer 38 and the vessel wall 12. In another example, the inflation fluid can be selected to have an acoustic impedance of a particular characteristic to serve as an acoustic match to minimize transmission losses across the wall of the inflated balloon 16. In another example, the inflation fluid can be selected to have a particular acoustic velocity in order to modify the near-field behavior of the ultrasound transducer 38.

[0067] In use, the catheter 10 can be advanced through the vascular system to the desired treatment area. Once the catheter 10 is located in the treatment area, the balloon 16 can be expanded. Then, energy can be supplied to the ultrasonic transducer 38. The expansion of the balloon 16 and / or the application of acoustic energy can break up the lesion 14 to enlarge or expand the blood vessel 12. Although not explicitly shown, the ultrasonic transducer 38 can be connected to a single control unit or connected to separate control units by one or more electrical conductors 48. The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0068] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 10 can be repositioned longitudinally and energy can again be delivered to the ultrasound transducer 38. If necessary, the catheter 10 can be rotated to fragment the lesion 14 around the circumference of the vessel at each longitudinal location. This process can be repeated at any number of longitudinal locations desired. It is contemplated that the balloon 16 can be expanded or partially expanded to allow the catheter 10 to move.

[0069] When the procedure is complete, the balloon 16 can be deflated or collapsed for removal from the body. It is contemplated that the balloon 16 and ultrasound sensor 38 can be collapsed in such a manner that all or part of the ultrasound transducer 38 and associated electronics are encased within the folds of the deflated balloon to reduce potential "catch" points on the catheter 10, which can also reduce the force required to remove the catheter 10.

[0070] It is contemplated that ultrasound transducer 38 may be positioned in addition to or in place of balloon 16 . Figure 2 A side view of another illustrative catheter 10' is shown in which an ultrasonic transducer 38' is positioned adjacent the distal end region 44 of the inner tubular member 24. The catheter 10' may be similar in form and function to the catheter 10' associated with FIG. Figure 1 The catheter 10 is described, wherein the same or similar reference numerals will be used to refer to the same or similar parts. The ultrasonic transducer 38' can be positioned at or near the distal end 50 of the catheter 10' and can be configured to direct the ultrasonic field 46' in a direction substantially parallel to or in line with the longitudinal axis of the catheter shaft 18. For example, the ultrasonic field 46' can be configured to fragment a chronic total occlusion. In the event that plaque / lesions are obstructing the passage of the catheter 10', the ultrasonic transducer 38' can be activated to break up the plaque / lesions and allow the catheter 10' to pass. Although only a single transducer 38' is shown, it is contemplated that the catheter 10' may include more than one ultrasonic transducer 38'. It is also contemplated that additional ultrasonic transducers 38' may be disposed on the balloon 16, such as Figure 1When more than one ultrasonic transducer 38' is provided, the ultrasonic transducers 38' can be configured to be activated individually or collectively as desired. Although not explicitly shown, an electrical connector can extend from the ultrasonic transducer 38' to a control unit configured to remain outside the body. The electrical conductors can be disposed within the lumens 30, 32 of the catheter shaft 18 or along the exterior of the catheter 10' as desired.

[0071] In use, the catheter 10' can be advanced through the vascular system to the desired treatment area. Once the catheter 10' is in the treatment area, the balloon 16 can be expanded to anchor and / or center the catheter 10', but this is not necessary. Then, energy can be supplied to the ultrasonic transducer 38'. The application of acoustic energy can break up the plaque / lesion to allow the catheter 10' to pass through the occlusion. In some cases, once the blockage is broken, the catheter 10' can be advanced longitudinally, and the balloon 16 can be expanded at the lesion to enlarge or expand the blood vessel. Although not explicitly shown, the ultrasonic transducer 38 can be connected to a single control unit or to a separate control unit by one or more electrical conductors. The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0072] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 10' can be repositioned longitudinally, and energy can be delivered to the ultrasonic transducer 38' again. If necessary, the catheter 10' can be rotated to fragment the lesions around the circumference of the vessel at each longitudinal location. The process can be repeated at any number of longitudinal locations desired. It is contemplated that the balloon 16 can be scaled or partially scaled to allow the catheter 10' to move. When the procedure is completed, the balloon 16 can be scaled or collapsed to be removed from the body.

[0073] Figure 3 1 is a cross-sectional view of another illustrative catheter system 100 that can be used to break up plaque and / or lesions. The figure depicts the system 100 in a patient's blood vessel 102 with a complete occlusion 104. The system 100 may include a guide catheter 106 having a lumen 108 extending therethrough. Another medical device 110 may extend through the lumen 108 of the guide catheter 106. The "second" medical device 110 may be, for example, a stent delivery system, an angioplasty catheter, a dilatation catheter, a cutting balloon catheter, a rotational atherectomy catheter, etc. During use, the medical device 110 may be advanced through the guide catheter 106 and advanced over a guidewire (not explicitly shown) to a position adjacent to the region of interest. When properly positioned, the medical device 110 may be used to perform appropriate diagnostic and / or therapeutic interventions.

[0074] One or more ultrasonic transducers 112 may be coupled at a distal region 114 adjacent to the guide catheter 106. In some embodiments, the one or more ultrasonic transducers 112 may be attached to an outer surface of the guide catheter 106. In such a case, the one or more ultrasonic transducers 112 may extend around the entire circumference of the guide catheter 106 or less than the entire circumference of the guide catheter, as desired. Alternatively or additionally, the one or more ultrasonic transducers 112 may be coupled to a distal surface 116 of the guide catheter 106 that extends generally perpendicular to the longitudinal axis of the guide catheter.

[0075] The guide catheter 106 may include any desired number of ultrasonic transducers 112, such as, but not limited to, one, two, three, four, five, ten, twenty or more. In some cases, one or more ultrasonic transducers 112 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. One or more ultrasonic transducers 112 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). One or more ultrasonic transducers 112 may be a single ultrasonic transducer, or one or more ultrasonic transducers 112 may include a series of ultrasonic transducers that may be operated to effectively function as a single ultrasonic transducer, thereby providing the desired acoustic pressure on the desired treatment area. It is also conceivable that each ultrasonic transducer 112 may operate independently of other ultrasonic transducers 112. The applied acoustic pressure range may be tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0076] One or more ultrasonic transducers 112 may be arranged in any desired configuration. In some examples, the ultrasonic transducers 112 may be staggered around the circumference and / or length of the guide catheter 106 so that the maximum number of ultrasonic transducers 112 may be positioned on the guide catheter 106. In another example, one or more ultrasonic transducers 112 may be arranged in a linear array, wherein each array extends substantially parallel to the longitudinal axis of the guide catheter 106. When so arranged, the array may be spaced evenly or eccentrically around the circumference of the guide catheter 106. In some examples, one or more ultrasonic transducers 112 may be arranged as circumferentially extending arrays, wherein each array extends around the circumference of the guide catheter 106. In other embodiments, one or more ultrasonic transducers 112 may be arranged along the guide catheter 106 in a spiral manner. For example, the ultrasonic transducer 112 may be spaced longitudinally and circumferentially from each adjacent ultrasonic transducer 112. These are just some examples. It should be understood that one or more ultrasonic transducers 112 may be positioned in any arrangement as desired. In some embodiments, each ultrasound transducer 112 may function independently of the other transducers, or the ultrasound transducers 112 may operate collectively to effectively function as a single ultrasound transducer.

[0077] Each of the one or more ultrasonic transducers 112 can generate an ultrasonic field 118 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 104. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 112, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 112, wherein the acoustic pressure wave emitted by the ultrasonic transducer 112 is not focused and can be controlled to be substantially uniform on the calcified lesion 104. The ultrasonic transducer 112 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. In other embodiments, the ultrasonic transducer 112 can be configured to emit ultrasonic waves in a single direction. For example, the ultrasonic transducer 112 can be configured to emit ultrasonic waves in a direction radially outward from the guide catheter 106 or in a direction substantially parallel to the longitudinal axis of the guide catheter 106. When two or more ultrasonic transducers 112 are provided, the ultrasonic transducers 112 may be arranged to transmit ultrasonic waves in different radial and / or axial directions, however this is not required.

[0078] In some cases, for example, the ultrasonic transducer 112 can be configured to apply a uniform or substantially uniform acoustic pressure to the end of the calcified lesion 104. As the lesion 104 breaks down, the guide catheter 106 can be advanced to break up a length of the lesion 104. In some cases, the ultrasonic transducer 112 can be positioned to emit ultrasonic waves in a direction generally parallel to the longitudinal axis of the guide catheter 106 to create a path through the lesion 104 for the guide catheter 106. Additional ultrasonic transducers 112 can be positioned along the length of the guide catheter 106 to emit radially extending ultrasonic waves to further break up the lesion 104 as the guide catheter 106 passes through the lesion 104. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 112 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm as measured from a central axis extending through the catheter shaft 18. Multiple ultrasonic transducers 112 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0079] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 112 can be many times greater than the diameter of the guide catheter 106. In some cases, the length of the ultrasonic transducer 112 can be at least as long as the length of the calcified lesion 104 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. As described above, the ultrasonic transducer 112 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements, which are driven in such a way that they effectively act as a single ultrasonic transducer. The ultrasonic transducer 112 can be electrically connected to an electronic source (not explicitly shown) via one or more wires (not explicitly shown). In some cases, two or more ultrasonic transducers can be connected to a single electronic source and driven and output at the same frequency. In other embodiments, two or more ultrasonic transducers can be connected to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 104.

[0080] In use, the guide catheter 106 can be advanced through the vascular system to the desired treatment area. Energy can then be supplied to the ultrasonic transducer 112. The application of acoustic energy can break up the plaque / lesion to allow the guide catheter 106 to pass through the occlusion 104. In some cases, once the occlusion 104 has been broken up, the guide catheter 106 can be advanced longitudinally. Although not explicitly shown, the ultrasonic transducers 112 can be connected to a single control unit or to separate control units by one or more electrical conductors. The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0081] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The guide catheter 106 can be repositioned longitudinally, and energy can again be delivered to the ultrasound transducer 112. If necessary, the guide catheter 106 can be rotated to fragment the lesion around the circumference of the vessel at each longitudinal location. This process can be repeated at any number of longitudinal locations desired.

[0082] Figure 32 is a cross-sectional view of another illustrative catheter system 200 that can be used to fragment plaque and / or lesions. The figure depicts system 200 within a patient's blood vessel 202 with a complete occlusion 204. System 200 may include a guide catheter 206 having a lumen 208 extending therethrough. Another medical device 210 may extend through lumen 208 of guide catheter 206. The "second" medical device 210 may be, for example, a stent delivery system, an angioplasty catheter, a dilation catheter, a cutting balloon catheter, a rotational atherectomy catheter, etc. During use, medical device 210 may be advanced through guide catheter 206 and over guidewire 212 to a position adjacent to an area of ​​interest. When properly positioned, medical device 210 may be used to perform appropriate diagnostic and / or therapeutic interventions.

[0083] One or more ultrasonic transducers 214 may be coupled at a distal region 216 adjacent to the guidewire 212. In some embodiments, the one or more ultrasonic transducers 214 may be attached to the outer surface of the guidewire 212. In such a case, the one or more ultrasonic transducers 214 may extend around the entire circumference of the guidewire 212 or less than the entire circumference of the guidewire 212, as desired. Alternatively or in addition, the one or more ultrasonic transducers 214 may be coupled to a distal surface of the guidewire 212 that extends generally perpendicular to the longitudinal axis of the guidewire 212. Although not explicitly shown, the ultrasonic transducer 214 may be additionally disposed on the guide catheter 206, such as with respect to Figure 3 described.

[0084] The guidewire 212 may include any desired number of ultrasonic transducers 214, such as, but not limited to, one, two, three, four, five, ten, twenty or more. In some cases, one or more ultrasonic transducers 214 may include a piezoelectric material that transmits sound pressure in response to an applied voltage. One or more ultrasonic transducers 214 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). One or more ultrasonic transducers 214 may be a single ultrasonic transducer, or one or more ultrasonic transducers 214 may include a series of ultrasonic transducers that may be operated to effectively function as a single ultrasonic transducer, thereby providing the desired sound pressure on the desired treatment area. It is also conceivable that each ultrasonic transducer 214 may be operated independently of other ultrasonic transducers 214. The applied sound pressure range may be tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0085] One or more ultrasonic transducers 214 can be arranged in any desired form. In some examples, the ultrasonic transducers 214 can be staggered around the circumference and / or length of the guidewire 212 so that the maximum number of ultrasonic transducers 214 can be positioned on the guidewire 212. In another example, one or more ultrasonic transducers 214 can be arranged in a linear array, wherein each array extends approximately parallel to the longitudinal axis of the guidewire 212. When so arranged, the array can be evenly or eccentrically spaced around the circumference of the guidewire 212. In some examples, one or more ultrasonic transducers 214 can be arranged as a circumferentially extending array, wherein each array extends around the circumference of the guidewire 212. In other embodiments, one or more ultrasonic transducers 214 can be arranged along the guidewire 212 in a spiral manner. For example, the ultrasonic transducer 214 can be longitudinally and circumferentially spaced from each adjacent ultrasonic transducer 214. These are just some examples. It should be understood that one or more ultrasonic transducers 214 can be positioned in any arrangement as needed. In some embodiments, each ultrasonic transducer 214 may function independently of the other transducers, or the ultrasonic transducers 214 may operate collectively to effectively function as a single ultrasonic transducer.

[0086] Each of the one or more ultrasonic transducers 214 can generate an ultrasonic field 218 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 204. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 214, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 214, wherein the acoustic pressure wave emitted by the ultrasonic transducer 214 is not focused and can be controlled to be substantially uniform on the calcified lesion 204. The ultrasonic transducer 214 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. In other embodiments, the ultrasonic transducer 214 can be configured to emit ultrasonic waves in a single direction. For example, the ultrasonic transducer 214 can be configured to emit ultrasonic waves in a direction radially outward from the guide wire 212 or in a direction substantially parallel to the longitudinal axis of the guide wire 212. When two or more ultrasonic transducers 214 are provided, the ultrasonic transducers 214 may be arranged to transmit ultrasonic waves in different radial and / or axial directions, however this is not required.

[0087] In some cases, for example, the ultrasonic transducer 214 can be configured to apply a uniform or substantially uniform acoustic pressure to the end of the calcified lesion 204. As the lesion 204 breaks down, the guidewire 212 can be advanced to break up a certain length of the lesion 204. In some cases, the ultrasonic transducer 214 can be positioned to emit ultrasonic waves in a direction generally parallel to the longitudinal axis of the guidewire 212 to create a path through the lesion 204 for the guidewire 212 and / or the guide catheter 206. Additional ultrasonic transducers 214 can be positioned along the length of the guidewire 212 to emit radially extending ultrasonic waves to further break up the lesion 204 as the guidewire 212 passes through the lesion 204. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a blood vessel with a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a blood vessel with a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 214 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm as measured from a central axis extending through the catheter shaft 18. Multiple ultrasonic transducers 214 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0088] In order to apply uniform or substantially uniform sound pressure in the near field, the length of the ultrasonic transducer 214 can be many times greater than the diameter of the guidewire 212. In some cases, the length of the ultrasonic transducer 214 can be at least as long as the length of the calcified lesion 204 to generate uniform or substantially uniform sound pressure over a length of about 20 to about 80 mm. As described above, the ultrasonic transducer 214 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements, which are driven in such a way that they effectively act as a single ultrasonic transducer. The ultrasonic transducer 214 can be electrically connected to an electronic source (not explicitly shown) via one or more wires (not explicitly shown). In some cases, two or more ultrasonic transducers can be connected to a single electronic source and driven and output at the same frequency. In other embodiments, two or more ultrasonic transducers can be connected to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the sound pressure applied to the lesion 204.

[0089] In use, the guidewire 212 can be advanced through the vascular system to the desired treatment area. Then, energy can be supplied to the ultrasonic transducer 214. The application of acoustic energy can break up the plaque / lesion to allow the guidewire 212 and / or the guide catheter 206 to pass through the occlusion 204. In some cases, once the occlusion 204 has been broken up, the guidewire 212 can be advanced longitudinally. Although not explicitly shown, the ultrasonic transducer 214 can be connected to a single control unit or connected to separate control units by one or more electrical conductors. The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0090] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The guidewire 212 may be repositioned longitudinally, and energy may again be delivered to the ultrasound transducer 214. If necessary, the guidewire 212 may be rotated to fragment the lesion around the circumference of the vessel at each longitudinal location. This process may be repeated at any number of longitudinal locations desired.

[0091] In some embodiments, in addition to or in lieu of an inflatable balloon, an expandable metal or polymer frame may be used to anchor and apply force to the lesion while emitting acoustic energy to the target tissue. The expandable frame or basket may be configured to apply a targeted outward force to the lesion while simultaneously fragmenting the lesion using acoustic energy. It is contemplated that acoustic energy may be transmitted through blood and / or soft tissue to fragment the lesion. In some cases, the use of an expandable basket may allow blood flow to be maintained during treatment.

[0092] Figure 5 Shown is a side view of another illustrative catheter 300 that may be used to treat a lesion disposed in a blood vessel 302 and located adjacent to an intravascular lesion 304. The catheter 300 may be configured to apply a force to the lesion 304, as well as to emit shock waves or an ultrasound field.

[0093] The catheter 300 may include an expandable basket 306 coupled to a catheter shaft 308. The shaft 308 may be an outer tubular member or catheter shaft, similar to a typical catheter shaft. For example, the catheter shaft 308 may be a tubular member extending from a distal region 312 to a proximal region (not explicitly shown) that is configured to remain outside the patient's body. The lumen 314 may extend from the distal region 312 to the proximal region.

[0094] The catheter 300 can also include an inner tubular member 316 that can be slidably disposed within the lumen 314 of the catheter shaft 308. At least a portion of the expandable basket 306 can be coupled to a distal region 330 of the inner tubular member 316. The catheter shaft 308 and the inner tubular member 316 can be made of a variety of different materials. For example, the catheter shaft 308 and the inner tubular member 316 can be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material.

[0095] The expandable basket 306 can be configured to transition between a collapsed configuration and an expanded configuration ( Figure 5 ). The expandable basket 306 can include a plurality of expandable positioning elements, such as longitudinally extending struts 318a, 318b (collectively 318), which can be coupled to the inner tubular member 316 at their proximal ends 320a, 320b (collectively 320). The distal ends 322a, 322b of the struts 318 can be coupled to a cap 336. In some cases, the cap 336 can include spacers that are used to maintain consistent spacing between each of the struts 318. However, this is not required. In some cases, the struts 318 can be arranged eccentrically. The struts 318 can be configured to extend generally along the longitudinal axis of the catheter shaft 308. Although the expandable basket 306 is shown as including two longitudinally extending struts 318, the expandable basket 306 can also include any desired number of struts 318, such as but not limited to one, two, three, four, five, six, or more. Other suitable expandable positioning elements may also be used, such as, but not limited to, rods or bars, individual hypotubes with portions removed to form struts, expandable stents with proximal and / or distal ends gathered together (e.g., woven, braided, laser cut, etc.), and the like.

[0096] The expandable basket 306 may be self-expandable or may require an external force to expand from a collapsed state. The self-expandable member may be formed of any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such a member may be formed of, for example, a shape memory alloy such as Nitinol or any other self-expandable material. When such a shape memory material is employed, the expandable basket 306 may be heat set in an expanded state and then compressed to fit within, for example, a catheter shaft 308. In another embodiment, a spring may be provided to achieve expansion. Alternatively, an external force such as, but not limited to, pneumatic methods, compressed fluids, pull wires, push wires, etc. may also be employed to expand the expandable basket 306. It is contemplated that a nickel-titanium alloy may achieve kink-resistant folding and self-expansion. In other examples, magnetic alloys, metals, metal alloys, polymers, composite materials, etc. may be used to form the expandable basket 306.

[0097] In other cases, a manual force applied to the inner tubular member 316 can manipulate or actuate the expandable basket 306 between the expanded and collapsed states. For example, the actuation element can include a centerline 310 extending through the expandable basket 306 and coupled to the cap 336. According to this embodiment, a pulling force applied to the wire proximally can allow the struts 318 to expand and move the expandable basket 306 into the expanded state. A pushing force applied to the wire distally can move and extend the struts 318 and / or otherwise transition the expandable basket 306 to a compressed or extended state. Other actuation mechanisms can also be utilized.

[0098] As discussed above, the expandable basket 306 can include a plurality of expandable positioning elements, such as longitudinally extending struts 318. The struts can each extend from a proximal region 320 to a distal region 322. An intermediate region 324a, 324b (collectively 324) can be disposed between the proximal region 320 and the distal region 322. It is contemplated that, in the expanded state, the intermediate region 324 of the struts 318 can contact the vessel wall 302 (and / or the lesion 304).

[0099] The inner tubular member 316 may include one or more ultrasonic transducers or transmitters 326. The ultrasonic transducer 326 may be coupled to the outer surface of the inner tubular member 316 adjacent to its distal portion. During surgery, the inner tubular member 316 may be positioned so that the ultrasonic transducer 326 is approximately aligned with the lesion 304. In some cases, the ultrasonic transducer 326 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 326 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 326 may be a single ultrasonic transducer, or the ultrasonic transducer 326 may include a series of ultrasonic transducers that may be operated to effectively act as a single ultrasonic transducer, thereby providing the desired acoustic pressure on the desired treatment area. The applied acoustic pressure range may be tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0100] The ultrasonic transducer 326 can generate an ultrasonic field 328 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 304. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 326, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 326, wherein the acoustic pressure wave emitted by the ultrasonic transducer 326 is not focused and can be controlled to be substantially uniform on the calcified lesion 304. The ultrasonic transducer 326 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart.

[0101] In some cases, for example, the ultrasonic transducer 326 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 304. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 326 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm when measured from a central axis extending through the catheter shaft 308. Although not explicitly shown, multiple ultrasonic transducers 326 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0102] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 326 can be many times greater than the diameter of the inner tubular member 316 and / or the catheter shaft 308. In some cases, the length of the ultrasonic transducer 326 can be at least as long as the length of the calcified lesion 304 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 326 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in such a way as to effectively act as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 326 can be electrically coupled to an electronic source via one or more wires. In some cases, two or more ultrasonic transducers can be coupled to a single electronic source and driven at the same frequency and output. In other embodiments, two or more ultrasonic transducers can be coupled to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 304.

[0103] In use, the catheter 300 can be advanced through the vascular system to the desired treatment area. Once the catheter 300 is located in the treatment area, the expandable basket 306 can be expanded. Then, energy can be supplied to the ultrasonic transducer 326. The expansion of the expandable basket 306 and / or the application of acoustic energy can break up the lesion 304 to enlarge or dilate the blood vessel 302. Although not explicitly shown, the ultrasonic transducer 326 can be connected to a single control unit or connected to separate control units by one or more electrical conductors (not explicitly shown). The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0104] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 300 may be repositioned longitudinally and energy may again be delivered to the ultrasound transducer 326. If necessary, the catheter 300 may be rotated to fragment the lesion around the circumference of the vessel at each longitudinal location. This process may be repeated at any number of longitudinal locations as desired. It is contemplated that the expandable basket 306 may be collapsed or partially collapsed to allow the catheter 300 to be moved. When the procedure is completed, the expandable basket 306 may be collapsed for removal from the body.

[0105] It is contemplated that the ultrasonic transducer 326 may be positioned in addition to or in place of the inner tubular member 316 . Figure 6 A side view of another illustrative catheter 300' is shown in which one or more ultrasound transducers 326' are positioned on the expandable basket 306. The catheter 300' may be similar in form and function to the related Figure 5 The catheter 300 is described, wherein the same or similar reference numerals will be used to refer to the same or similar parts. One or more ultrasonic transducers 326' can be positioned on one or more of the longitudinally extending struts 318 of the expandable basket 306. In some examples, the one or more ultrasonic transducers 326' can be positioned on the middle portion 324 of the strut configured to contact the vessel wall 302, but this is not required. The one or more ultrasonic transducers 326' can be positioned along any portion of the strut 318 as desired. It is contemplated that positioning the ultrasonic transducer 326 on the strut 318 can bring the ultrasonic transducer closer to the lesion 304 for targeted and / or localized therapy. Ultrasonic waves 328' can be transmitted through the vessel wall 302.

[0106] The catheter 300' may include less than four ultrasonic transducers 326' or more than four ultrasonic transducers 326' as desired. It is also contemplated that additional ultrasonic transducers 326' may be disposed on the inner tubular member 316, as shown in FIG15. When more than one ultrasonic transducer 326' is provided, the ultrasonic transducers 326' may be configured to be activated individually or collectively as desired. Although not explicitly shown, an electrical connector may extend from the ultrasonic transducer 326' to a control unit configured to remain outside the body. As desired, an electrical conductor may be disposed within the lumen 314 of the catheter shaft 308 or disposed along the exterior of the catheter 300'.

[0107] In use, the catheter 300' can be advanced through the vascular system to the desired treatment area. Once the catheter 300' is located in the treatment area, the expandable basket 306 can be expanded to anchor the catheter 300'. Energy can then be supplied to the ultrasonic transducer 326'. The application of acoustic energy and force through the expandable basket 306 can break up the plaque / lesion. Although not explicitly shown, the ultrasonic transducers 326' can be connected to a single control unit or connected to separate control units by one or more electrical conductors. The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0108] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 300' can be repositioned longitudinally and energy can again be delivered to the ultrasonic transducer 326'. If necessary, the catheter 300' can be rotated to fragment the lesion around the circumference of the vessel 302 at each longitudinal location. The process can be repeated at any number of longitudinal locations as desired. It is contemplated that the expandable basket 306 can be collapsed to allow the catheter 300' to be moved. When the procedure is completed, the expandable basket 306 can be collapsed for removal from the body.

[0109] Figure 7 Shown is a side view of another illustrative catheter 400 that may be used to treat a lesion disposed in a blood vessel 402 and located adjacent to an intravascular lesion 404. The catheter 400 may be configured to apply a force to the lesion 404, as well as to emit shock waves or an ultrasound field.

[0110] The catheter 400 may include an expandable basket 406 coupled to a catheter shaft 408. The shaft 408 may be an outer tubular member or catheter shaft, similar to a typical catheter shaft. For example, the catheter shaft 408 may be a tubular member extending from a distal region 410 to a proximal region (not explicitly shown) that is configured to remain outside the patient's body. A lumen 412 may extend from the distal region 410 to the proximal region.

[0111] The catheter 400 can also include an inner tubular member 414 that can be slidably disposed within the lumen 412 of the catheter shaft 408. At least a portion of the expandable basket 406 can be coupled to a distal region 416 of the inner tubular member 414. The catheter shaft 408 and the inner tubular member 414 can be made of a variety of different materials. For example, the catheter shaft 408 and the inner tubular member 414 can be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material.

[0112] The expandable basket 406 can be configured to transition between a collapsed configuration and an expanded configuration ( Figure 7). The expandable basket 406 may include two or more expansion circular protrusions 418a, 418b (collectively referred to as 418). The proximal end 420 of the proximal circular protrusion 418a may be coupled to the inner tubular member 414, and the distal end 422 of the proximal circular protrusion 418a may be coupled to the sliding ring 424. The proximal end 426 of the distal circular protrusion 418b may be coupled to the sliding ring 424, and the distal end 428 may be coupled to the pull wire 430. The sliding ring 424 may couple the circular protrusions 418a, 418b so that movement of one circular protrusion causes movement of the other circular protrusion. Although the expandable basket 406 is shown as having two circular protrusions 418, it is contemplated that the expandable basket 406 may include more than two circular protrusions 418 as desired. If so configured, additional sliding rings may be used to couple additional circular protrusions.

[0113] Each circular protrusion 418 can include a plurality of expandable positioning elements, such as longitudinally extending struts 432a, 432b, 432c, 432d (collectively referred to as 432). In some cases, the struts 432 of each circular protrusion 418 can be evenly spaced. However, this is not required. In some cases, the struts 418 of each circular protrusion 418 can be eccentrically arranged. The struts 432 can be configured to extend roughly along the longitudinal axis of the catheter shaft 408. Although each circular protrusion 418 is shown as including two longitudinally extending struts 432, each circular protrusion 418 can include any desired number of struts 432, such as but not limited to one, two, three, four, five, six or more. In addition, each circular protrusion 418 does not have to have the same number of struts 432 or have the same arrangement of struts 432. Other suitable expandable positioning elements may also be used, such as, but not limited to, rods or bars, individual hypotubes with portions removed to form struts, expandable stents with proximal and / or distal ends gathered together (e.g., woven, braided, laser cut, etc.), and the like.

[0114] The expandable basket 406 may be self-expandable or may require an external force to expand from a collapsed state. The self-expandable member may be formed of any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such a member may be formed of, for example, a shape memory alloy such as Nitinol or any other self-expandable material. When such a shape memory material is employed, the expandable basket 406 may be heat set in an expanded state and then compressed to fit within, for example, a catheter shaft 408. In another embodiment, a spring may be provided to achieve expansion. Alternatively, an external force such as, but not limited to, pneumatic methods, compressed fluids, pull wires, push wires, etc. may also be employed to expand the expandable basket 406. It is contemplated that a nickel-titanium alloy may achieve kink-resistant folding and self-expansion. In other examples, magnetic alloys, metals, metal alloys, polymers, composite materials, etc. may be used to form the expandable basket 406.

[0115] In other cases, a manual force applied to the inner tubular member 414 can manipulate or actuate the expandable basket 406 between the expanded and collapsed states. For example, the actuating element can include a distal end 428 extending through the centerline 430 of the expandable basket 406 and coupled to the distal circular protrusion 418. According to this embodiment, a pulling force applied to the wire proximally can allow the struts 432 to expand and move the expandable basket 406 to the expanded state. A pushing force applied to the wire distally can move and extend the struts 432 and / or otherwise convert the ablation device to a compressed or extended state. Other actuating mechanisms can also be utilized. For example, in some cases, the inner tubular member 414 can be actuated relative to the centerline 430.

[0116] As discussed above, the expandable basket 406 can include a plurality of expandable positioning elements, such as longitudinally extending struts 432. The struts can each extend from a proximal region to a distal region. An intermediate region can be disposed between the proximal region and the distal region. It is contemplated that, in an expanded state, the intermediate region of the struts 432 can contact the vessel wall 402 (and / or lesion 404).

[0117] The inner tubular member 414 may include one or more ultrasonic transducers or transmitters 434. The ultrasonic transducer 434 may be coupled to the outer surface of the inner tubular member 414 adjacent to its distal portion. Alternatively or additionally, one or more ultrasonic transducers may be positioned on one or more of the pillars 432. During surgery, the inner tubular member 414 may be positioned so that the ultrasonic transducer 434 is approximately aligned with the lesion 404. In some cases, the ultrasonic transducer 434 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 434 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 434 may be a single ultrasonic transducer, or the ultrasonic transducer 434 may include a series of ultrasonic transducers that may be operated to effectively function as a single ultrasonic transducer, thereby providing the desired acoustic pressure on the desired treatment area. The applied acoustic pressure may range from tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0118] The ultrasonic transducer 434 can generate an ultrasonic field 436 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 404. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 434, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 434, wherein the acoustic pressure wave emitted by the ultrasonic transducer 434 is not focused and can be controlled to be substantially uniform on the calcified lesion 404. The ultrasonic transducer 434 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. When two or more ultrasonic transducers 434 are provided, the ultrasonic transducers 434 can be arranged to emit ultrasonic waves in different radial directions, but this is not required.

[0119] In some cases, for example, the ultrasonic transducer 434 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 404. In cardiovascular disease states, the vascular lesion can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, the vascular lesion can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 434 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm when measured from a central axis extending through the catheter shaft 408. Although not explicitly shown, multiple ultrasonic transducers 434 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0120] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 434 can be many times greater than the diameter of the inner tubular member 414 and / or the catheter shaft 408. In some cases, the length of the ultrasonic transducer 434 can be at least as long as the length of the calcified lesion 404 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 434 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in such a way that they effectively act as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 434 can be electrically coupled to an electronic source via one or more wires. In some cases, two or more ultrasonic transducers can be coupled to a single electronic source and driven at the same frequency and output. In other embodiments, two or more ultrasonic transducers can be coupled to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 404.

[0121] In use, the catheter 400 can be advanced through the vascular system to the desired treatment area. Once the catheter 400 is located in the treatment area, the expandable basket 406 can be expanded. Then, energy can be supplied to the ultrasonic transducer 434. The expansion of the expandable basket 406 and / or the application of acoustic energy can break up the lesion 404 to enlarge or dilate the blood vessel 402. Although not explicitly shown, the ultrasonic transducer 434 can be connected to a single control unit or connected to separate control units by one or more electrical conductors (not explicitly shown). The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0122] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 400 may be repositioned longitudinally and energy may again be delivered to the ultrasound transducer 434. If necessary, the catheter 400 may be rotated to perform ablation around the circumference of the vessel at each longitudinal location. The process may be repeated at any number of longitudinal locations as desired. It is contemplated that the expandable basket 406 may be collapsed or partially collapsed to allow the catheter 400 to be moved. When the procedure is completed, the expandable basket 406 may be collapsed for removal from the body.

[0123] Figure 8 Shown is a side view of another illustrative catheter 500 that may be used to treat a lesion disposed in a blood vessel 502 and located adjacent to an intravascular lesion 504. Catheter 500 may be configured to apply a force to lesion 504, as well as emit shock waves or an ultrasound field.

[0124] The catheter 500 may include an expandable basket 506 coupled to a catheter shaft 508. The shaft 508 may be an outer tubular member or catheter shaft, similar to a typical catheter shaft. For example, the catheter shaft 508 may be a tubular member extending from a distal region 510 to a proximal region (not explicitly shown) that is configured to remain outside the patient's body. The lumen 512 may extend from the distal region 510 to the proximal region.

[0125] The catheter 500 can also include an inner tubular member 514 that can be slidably disposed within the lumen 512 of the catheter shaft 508. At least a portion of the expandable basket 506 can be coupled to a distal region 516 of the inner tubular member 514. The catheter shaft 508 and the inner tubular member 514 can be made of a variety of different materials. For example, the catheter shaft 508 and the inner tubular member 514 can be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material.

[0126] The expandable basket 506 can be configured to transition between a collapsed configuration and an expanded configuration ( Figure 8 ). The expandable basket 506 may include a generally helically extending strut 518. The proximal end 522 of the strut 518 may be coupled to the inner tubular member 514, and the distal end 524 of the strut 518 may be coupled to the centerline 520. The strut 518 may be generally spring-shaped. It is contemplated that the distance between adjacent windings may be increased or decreased as desired. In some cases, the distance between adjacent windings may be evenly spaced. However, this is not required. In some cases, the distance between adjacent windings may be arranged eccentrically. The strut 518 may be configured to extend along the length of the inner tubular member 514 of the catheter shaft 508. Although the expandable basket 506 is shown as including one strut 518, the expandable basket 506 may also include any desired number of struts 518, such as, but not limited to, one, two, three, four, five, six, or more. Other suitable expandable positioning elements may also be used, such as, but not limited to, rods or bars, individual hypotubes with portions removed to form struts, expandable stents with proximal and / or distal ends gathered together (e.g., woven, braided, laser cut, etc.), and the like.

[0127] The expandable basket 506 may be self-expandable or may require an external force to expand from a collapsed state. The self-expandable member may be formed of any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such a member may be formed of, for example, a shape memory alloy such as Nitinol or any other self-expandable material. When such a shape memory material is employed, the expandable basket 506 may be heat set in an expanded state and then compressed to fit within, for example, a catheter shaft 508. In another embodiment, a spring may be provided to achieve expansion. Alternatively, an external force such as, but not limited to, pneumatic methods, compressed fluids, pull wires, push wires, etc. may also be employed to expand the expandable basket 506. It is contemplated that a nickel-titanium alloy may achieve kink-resistant folding and self-expansion. In other examples, magnetic alloys, metals, metal alloys, polymers, composite materials, etc. may be used to form the expandable basket 506.

[0128] In other cases, a manual force applied to the inner tubular member 514 can manipulate or actuate the expandable basket 506 between the expanded and collapsed states. For example, the actuating element can include a distal end 524 extending through the centerline 520 of the expandable basket 506 and coupled to the struts 518. According to this embodiment, a pulling force applied to the wire proximally can allow the struts 518 to expand and move the expandable basket 506 into the expanded state. A pushing force applied to the wire distally can move and extend the struts 518 and / or otherwise convert the ablation device to a compressed or extended state. Other actuating mechanisms can also be utilized. For example, in some cases, the inner tubular member 514 can be actuated relative to the centerline 520.

[0129] The inner tubular member 514 may include one or more ultrasonic transducers or transmitters 526. The ultrasonic transducer 526 may be coupled to the outer surface of the inner tubular member 514 adjacent to its distal portion. Alternatively or additionally, one or more ultrasonic transducers may be positioned on the support 518. During surgery, the inner tubular member 514 may be positioned so that the ultrasonic transducer 526 is approximately aligned with the lesion 504. In some cases, the ultrasonic transducer 526 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 526 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 526 may be a single ultrasonic transducer, or the ultrasonic transducer 526 may include a series of ultrasonic transducers that may be operated to effectively act as a single ultrasonic transducer, thereby providing the desired acoustic pressure on the desired treatment area. The applied acoustic pressure range may be tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0130] The ultrasonic transducer 526 can generate an ultrasonic field 528 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 504. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 526, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 526, wherein the acoustic pressure wave emitted by the ultrasonic transducer 526 is not focused and can be controlled to be substantially uniform on the calcified lesion 504. The ultrasonic transducer 526 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. When two or more ultrasonic transducers 526 are provided, the ultrasonic transducers 526 can be arranged to emit ultrasonic waves in different radial directions, but this is not required.

[0131] In some cases, for example, the ultrasonic transducer 526 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 504. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 526 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm when measured from a central axis extending through the catheter shaft 508. Although not explicitly shown, multiple ultrasonic transducers 526 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0132] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 526 can be many times greater than the diameter of the inner tubular member 514 and / or the catheter shaft 508. In some cases, the length of the ultrasonic transducer 526 can be at least as long as the length of the calcified lesion 504 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 526 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in such a way as to effectively act as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 526 can be electrically coupled to an electronic source via one or more wires. In some cases, two or more ultrasonic transducers can be coupled to a single electronic source and driven at the same frequency and output. In other embodiments, two or more ultrasonic transducers can be coupled to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 504.

[0133] In use, the catheter 500 can be advanced through the vascular system to the desired treatment area. Once the catheter 500 is located in the treatment area, the expandable basket 506 can be expanded. Then, energy can be supplied to the ultrasonic transducer 526. The expansion of the expandable basket 506 and / or the application of acoustic energy can break up the lesion 504 to enlarge or dilate the blood vessel 502. Although not explicitly shown, the ultrasonic transducer 526 can be connected to a single control unit or connected to separate control units by one or more electrical conductors (not explicitly shown). The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0134] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 500 may be repositioned longitudinally and energy may again be delivered to the ultrasound transducer 526. If necessary, the catheter 500 may be rotated to perform ablation around the circumference of the vessel at each longitudinal location. The process may be repeated at any number of longitudinal locations as desired. It is contemplated that the expandable basket 506 may be collapsed or partially collapsed to allow the catheter 500 to be moved. When the procedure is completed, the expandable basket 506 may be collapsed for removal from the body.

[0135] Fig. 9 Shown is a side view of another illustrative catheter 600 that may be used to treat a lesion disposed in a blood vessel 602 and located adjacent to an intravascular lesion 604. Catheter 600 may be configured to apply a force to lesion 604, as well as emit shock waves or an ultrasound field.

[0136] The catheter 600 may include an expandable basket 606 coupled to a catheter shaft 608. The shaft 608 may be an outer tubular member or catheter shaft, similar to a typical catheter shaft. For example, the catheter shaft 608 may be a tubular member extending from a distal region 610 to a proximal region (not explicitly shown) that is configured to remain outside the patient's body. A lumen 612 may extend from the distal region 610 to the proximal region.

[0137] The catheter 600 can also include an inner tubular member 614 that can be slidably disposed within the lumen 612 of the catheter shaft 608. At least a portion of the expandable basket 606 can be coupled to a distal region 616 of the inner tubular member 614. The catheter shaft 608 and the inner tubular member 614 can be made of a variety of different materials. For example, the catheter shaft 608 and the inner tubular member 614 can be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material.

[0138] The expandable basket 606 can be configured to transition between a collapsed configuration and an expanded configuration ( Fig. 9). The proximal end 622 of the expandable basket 606 can be coupled to the inner tubular member 614, and the distal end 624 of the expandable basket 606 can be coupled to the centerline 620. The expandable basket 606 can have a woven structure made of a plurality of filaments or struts 618 that form a generally tubular wall. In some embodiments, the expandable basket 606 can be knitted or woven from a single filament or strut that is interwoven with itself and defines an opening that extends through the thickness of the tubular wall of the expandable basket 606. In other embodiments, the expandable basket 606 can be woven from a plurality of filaments or struts that are interwoven with each other and define an opening that extends along the length of the tubular wall of the expandable basket 606 and around its circumference. In another embodiment, the expandable basket 606 can be knitted. In yet another embodiment, the expandable basket 606 can be a knotted type. In yet another embodiment, the expandable basket 606 can be a laser cut tubular member. The laser cut tubular member may have an open and / or closed cell geometry comprising one or more interconnected integral filaments or struts defining pores therebetween, wherein the pores extend along the length of the tubular wall and around its circumference.

[0139] The expandable basket 606 may be self-expandable or may require an external force to expand from a collapsed state. The self-expandable member may be formed of any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such a member may be formed of, for example, a shape memory alloy such as Nitinol or any other self-expandable material. When such a shape memory material is employed, the expandable basket 606 may be heat set in an expanded state and then compressed to fit within, for example, a catheter shaft 608. In another embodiment, a spring may be provided to achieve expansion. Alternatively, an external force such as, but not limited to, pneumatic methods, compressed fluids, pull wires, push wires, etc. may also be employed to expand the expandable basket 606. It is contemplated that a nickel-titanium alloy may achieve kink-resistant folding and self-expansion. In other examples, magnetic alloys, metals, metal alloys, polymers, composite materials, etc. may be used to form the expandable basket 606.

[0140] In other cases, a manual force applied to the inner tubular member 614 can manipulate or actuate the expandable basket 606 between the expanded and collapsed states. For example, the actuating element can include a centerline 620 extending through the expandable basket 606 and coupled to a distal end 624 of the expandable basket 606. According to this embodiment, a pulling force applied to the wire proximally can allow the expandable basket 606 to expand and move the expandable basket 606 to the expanded state. A pushing force applied to the wire distally can move and extend the expandable basket 606 and / or otherwise transfer the ablation device to a compressed or extended state. Other actuating mechanisms can also be utilized. For example, in some cases, the inner tubular member 614 can be actuated relative to the centerline 620.

[0141] The inner tubular member 614 may include one or more ultrasonic transducers or transmitters 626. The ultrasonic transducer 626 may be coupled to the outer surface of the inner tubular member 614 adjacent to its distal portion. Alternatively or additionally, one or more ultrasonic transducers may be positioned on the expandable basket 606. During surgery, the inner tubular member 614 may be positioned so that the ultrasonic transducer 626 is approximately aligned with the lesion 604. In some cases, the ultrasonic transducer 626 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 626 may be driven at one or more frequencies in the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 626 may be a single ultrasonic transducer, or the ultrasonic transducer 626 may include a series of ultrasonic transducers that may be operated to effectively function as a single ultrasonic transducer to provide the desired acoustic pressure over the desired treatment area. The applied acoustic pressure may range from tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0142] The ultrasonic transducer 626 can generate an ultrasonic field 628 including a near field region and a far field region. In the near field region, dynamic acoustic pressure can be periodically applied to the calcified lesion 604. As used herein, the near field region refers to a region radially adjacent to the surface of the ultrasonic transducer 626, for example, a region extending outward from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 626, wherein the acoustic pressure wave emitted by the ultrasonic transducer 626 is not focused and can be controlled to be substantially uniform on the calcified lesion 604. The ultrasonic transducer 626 can be configured to emit ultrasonic waves in two opposite directions or about 180° apart. When two or more ultrasonic transducers 626 are provided, the ultrasonic transducers 626 can be arranged to emit ultrasonic waves in different radial directions, but this is not required.

[0143] In some cases, for example, the ultrasonic transducer 626 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 604. In cardiovascular disease states, vascular lesions can span a length of about 10 millimeters (mm) to about 25 mm in a vessel having a diameter of about 2 mm to about 4 mm. In peripheral vascular disease states, vascular lesions can span a length of up to about 200 mm in a vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 626 can be configured to apply a uniform or substantially uniform acoustic pressure over a length of about 10 mm to about 60 mm at a radial distance of about 1 mm to about 8 mm when measured from a central axis extending through the catheter shaft 608. Although not explicitly shown, multiple ultrasonic transducers 626 can be used and configured to extend an effective treatment length, such as up to a length of about 200 mm.

[0144] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 626 can be many times greater than the diameter of the inner tubular member 614 and / or the catheter shaft 608. In some cases, the length of the ultrasonic transducer 626 can be at least as long as the length of the calcified lesion 604 to generate a uniform or substantially uniform acoustic pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 626 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in such a way as to effectively act as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 626 can be electrically coupled to an electronic source via one or more wires. In some cases, two or more ultrasonic transducers can be coupled to a single electronic source and driven at the same frequency and output. In other embodiments, two or more ultrasonic transducers can be coupled to two or more different electronic sources and driven independently of each other, so that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 604.

[0145] In use, the catheter 600 can be advanced through the vascular system to the desired treatment area. Once the catheter 600 is located in the treatment area, the expandable basket 606 can be expanded. Then, energy can be supplied to the ultrasonic transducer 626. The expansion of the expandable basket 606 and / or the application of acoustic energy can break up the lesion 604 to enlarge or dilate the blood vessel 602. Although not explicitly shown, the ultrasonic transducer 626 can be connected to a single control unit or connected to separate control units by one or more electrical conductors (not explicitly shown). The amount of energy delivered to the ultrasonic transducer can be determined by the desired treatment and feedback provided by other components of the catheter or other device.

[0146] Once a particular location has been treated, it may be necessary to perform further procedures at different longitudinal locations. The catheter 600 may be repositioned longitudinally and energy may again be delivered to the ultrasound transducer 626. If necessary, the catheter 600 may be rotated to perform ablation around the circumference of the vessel at each longitudinal location. The process may be repeated at any number of longitudinal locations as desired. It is contemplated that the expandable basket 606 may be collapsed or partially collapsed to allow the catheter 600 to be moved. When the procedure is completed, the expandable basket 606 may be collapsed for removal from the body.

[0147] The materials that can be used for the various components of the systems disclosed herein and their various elements can include those commonly associated with medical devices. For simplicity, the following discussion refers to the system. However, this is not intended to limit the devices and methods described herein, as the discussion can be applicable to other elements, components, parts or devices disclosed herein, such as, but not limited to, catheter shafts, inflatable balloons, expandable baskets, center lines, etc. and / or elements or parts thereof.

[0148] In some embodiments, the system and / or components thereof may be made of metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or the like, or other suitable materials.

[0149] Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxyethylene (POM, e.g., commercially available from DuPont ), polyether block esters, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., commercially available from DSM Engineering Plastics ), ether- or ester-based copolymers (e.g., butylene phthalate / poly(alkylene ether) esters and / or other polyester elastomers, such as those commercially available from DuPont ), polyamide (for example, commercially available from Bayer or commercially available from Elf Atochem ), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, for example, available under the trade name Commercially available), ethylene-vinyl acetate copolymer (EVA), silicone, polyethylene (PE), High density polyethylene, Low-density polyethylene, linear low-density polyethylene (e.g. ), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly(p-phenylene terephthalamide) (e.g., ), polysulfone, nylon, nylon-12 (such as commercially available from EMS American Grilon ), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, polyurethane silicone copolymers (e.g., Aortech Biomaterials' or AdvanSource Biomaterials ), biocompatible polymers, other suitable materials or mixtures, combinations, copolymers, polymer / metal composites, etc. In some embodiments, the component can be mixed with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6 percent LCP.

[0150] Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steel; low carbon steel; nickel titanium alloys, such as linear elastic and / or superelastic Nitinol; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as 625, UNS:N06022, such as UNS:N10276, such as other alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as 400, 400, 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as etc.), nickel-molybdenum alloys (e.g., UNS: N10665, such as ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.); platinum-rich stainless steel; titanium; platinum; palladium; gold; combinations thereof; or any other suitable material.

[0151] In at least some embodiments, part or all of the system, and / or its components may also be doped with, made of, or otherwise include radiopaque materials. Radiopaque materials should be understood as materials that are capable of producing a relatively bright image on a fluorescent screen or with another imaging technique during a medical procedure. This relatively bright image helps the user of the system determine its position. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymer materials loaded with radiopaque fillers, and the like. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of the system to achieve the same results.

[0152] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to the systems and / or other elements disclosed herein. For example, the system and / or its components or portions may be made of materials that do not substantially distort the image and create a large number of artifacts (i.e., gaps in the image). For example, certain ferromagnetic materials may not be suitable because they may create artifacts in MRI images. The system or portions thereof may also be made of materials that can be imaged by MRI machines. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as etc.), Nitinol, etc.

[0153] In some embodiments, the systems and / or other elements disclosed herein may include and / or be treated with suitable therapeutic agents. Some examples of suitable therapeutic agents may include anticoagulants (such as heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethyl ketone)); antiproliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory drugs (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalazine); anti-tumor / antiproliferative / anti-mitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilone, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetics (such as lidocaine, bupivacaine, and ropivacaine); anticoagulants (such as D-Phe-Pro-Arg chloromethyl ketones, compounds containing RGD peptides, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides); vascular cell growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcription activators, and translation promoters); vascular cell growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcription inhibitors, translation inhibitors, replication inhibitors, inhibitory antibodies, antibodies to growth factors, bifunctional molecules composed of growth factors and cytotoxins, bifunctional molecules composed of antibodies and cytotoxins); cholesterol-lowering agents; vasodilators; and agents that interfere with endogenous vasoactive mechanisms.

[0154] It should be understood that the present invention is in many respects merely illustrative. Changes may be made in the details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the invention. To the extent appropriate, this may include using any of the features of an example embodiment used in other embodiments. Of course, the scope of the invention is defined by the language of the appended claims.

Claims

1. A method for decomposing intravascular lesions, the method comprising: Advancing a catheter through the vascular system to a target location, the catheter comprising: catheter shaft; an expandable member secured to a distal portion of the catheter shaft; and one or more ultrasonic transducers; and The one or more ultrasound transducers are activated to emit an ultrasound field directed toward the target location.

2. The method according to claim 1, wherein: The catheter also includes a guidewire extending through the lumen of the catheter shaft.

3. The method according to any one of claims 1 to 2, wherein: At least one of the one or more ultrasonic transducers is coupled to the expandable member.

4. The method according to any one of claims 1 to 3, wherein: The catheter shaft includes an outer tubular member and an inner tubular member.

5. The method according to claim 4, wherein: At least one of the one or more ultrasonic transducers is coupled to the inner tubular member.

6. The method according to any one of claims 1 to 5, wherein: The expandable member includes an inflatable balloon.

7. The method according to any one of claims 1 to 5, wherein: The expandable member includes an expandable basket.

8. The method according to claim 7, wherein: The expandable basket includes two or more circular protrusions.

9. The method of claim 8, further comprising one or more sliding rings positioned between and coupled to the two or more circular protrusions.

10. The method according to any one of claims 7 to 9, wherein: The expandable basket includes one or more longitudinally extending struts.

11. The method according to claim 7, wherein: The expandable basket includes helically extending struts.

12. The method according to claim 7, wherein: The expandable basket comprises a woven structure.

13. The method according to any one of claims 1 to 12, wherein: The one or more ultrasound transducers are arranged in one or more arrays.

14. The method according to any one of claims 1 to 13, wherein: The ultrasound field is emitted radially from the catheter.

15. The method according to any one of claims 1 to 13, wherein: The ultrasound field is emitted in a direction parallel to the longitudinal axis of the catheter shaft.

Images