Cutting and Scoring Lithotripter Balloon Catheter

Abstract

The catheter is configured to substantially simultaneously incise or score a lesion and deliver a pressure wave to the lesion. An exemplary catheter can include a catheter shaft, an expandable member fixed to a distal portion of the catheter shaft, an incision member fixed to the expandable member, and an ultrasonic transducer disposed within the expandable member. A tether can be attached between the expandable member and the emitter that self - orients the emitter toward the target tissue due to non - uniform expansion of the expandable member resulting from different compliances between the target tissue and the surrounding tissue.

Description

Technical Field

[0001] The present disclosure relates to an angioplasty balloon catheter having an incision or scoring element mounted on an angioplasty balloon having an internal lithotripter emitter. More particularly, the present disclosure relates to an angioplasty balloon for altering lesion compliance within or near a blood vessel lumen.

Background Art

[0002] Many patients suffer from occluded arteries and other blood vessels that restrict blood flow. The occlusion can be a partial occlusion that reduces blood flow through the occluded portion of the blood vessel, or a complete occlusion (e.g., chronic total occlusion) that substantially blocks blood flow through the occluded blood vessel. Occluded, stenosed, or narrowed blood vessels can be treated using a number of relatively non-invasive medical procedures including percutaneous transluminal angioplasty (PTA), percutaneous transluminal coronary angioplasty (PTCA), atherectomy, and lithotripsy. However, the effectiveness of intravascular lithotripsy can be reduced for eccentric calcified lesions. Each of the known medical devices, systems, and methods has certain advantages and disadvantages. There is a current need to provide alternative medical devices and systems, including devices and systems for treating occluded or calcified lesions.

Summary of the Invention

[0003] The present disclosure relates to several alternative designs, materials, and methods for fabricating medical device structures and assemblies. In a first example, the catheter may comprise a catheter shaft, an expandable member fixed to a distal portion of the catheter shaft, an incision member fixed to the expandable member, and an ultrasonic transducer disposed within the expandable member.

[0004] Instead of, or in addition to, any of the above examples, in another example, the catheter shaft may include an inner tubular member defining a first lumen and an outer tubular member defining a second lumen.

[0005] Instead of, or in addition to, any of the above examples, in another example, the inner tubular member may be torque-applicable. Instead of, or in addition to, any of the above examples, in another example, the outer tubular member may be torque-applicable.

[0006] Instead of, or in addition to, any of the above examples, in another example, the expandable member may include an inflatable balloon. Instead of, or in addition to, any of the above examples, in another example, the expandable member may include an expandable cage.

[0007] Instead of, or in addition to, any of the above examples, in another example, the ultrasonic transducer may be attached to the outer surface of the inner tubular member. Instead of, or in addition to, any of the above examples, in another example, the catheter may further include an emitter shaft.

[0008] Instead of, or in addition to, any of the above examples, in another example, the ultrasonic transducer may be attached to the distal portion of the emitter shaft. Instead of, or in addition to, any of the above examples, in another example, the emitter shaft may be rotatable relative to the catheter shaft.

[0009] Instead of, or in addition to, any of the above examples, in another example, the catheter may further include a plurality of tethers extending from the emitter shaft to the expandable member. Instead of, or in addition to, any of the above examples, in another example, each of the plurality of tethers may include a filament.

[0010] Instead of, or in addition to, any of the above examples, in another example, each of the plurality of tethers may include a planar material sheet. Instead of, or in addition to, any of the above examples, in another example, the plurality of tethers may be configured to rotate the emitter shaft about the longitudinal axis of the emitter shaft as the expandable member expands.

[0011] Instead of, or in addition to, any of the above examples, in another example, the incision member may be configured to score the lesion while the ultrasonic transducer delivers a sound pressure wave to the lesion.

[0012] Instead of, or in addition to, any of the above examples, in another example, the plurality of tethers may be configured to rotate the emitter shaft so as to orient the ultrasonic transducer towards the lesion.

[0013] Instead of, or in addition to, any of the above examples, in another example, the plurality of tethers may be uniformly distributed around the outer circumference of the emitter shaft. Instead of, or in addition to, any of the above examples, in another example, the plurality of tethers may include three tethers.

[0014] Instead of, or in addition to, any of the above examples, in another example, the ultrasonic transducer may be configured to provide a substantially uniform sound pressure wave along the length of the lesion.

[0015] Instead of, or in addition to, any of the above examples, in another example, the expandable member may include an expandable basket. Instead of, or in addition to, any of the above examples, in another example, the expandable member may include a plurality of longitudinally extending struts.

[0016] In another example, the balloon catheter may comprise a catheter shaft, an inflatable balloon fixed to the distal portion of the catheter shaft, an incision member fixed to the inflatable balloon, an emitter shaft, and an ultrasonic transducer disposed on the emitter shaft and within the inflatable balloon.

[0017] Instead of, or in addition to, any of the above examples, in another example, the catheter shaft may include an inner tubular member defining a guide wire lumen and an outer tubular member defining an inflation lumen.

[0018] Instead of, or in addition to, any of the above examples, in another example, the emitter shaft may be disposed within the guide wire lumen. Instead of, or in addition to, any of the above examples, in another example, the emitter shaft may be disposed within the inflation lumen.

[0019] Instead of, or in addition to, any of the above examples, in another example, the emitter shaft may be rotatable relative to the catheter shaft. Instead of, or in addition to, any of the above examples, in another example, the ultrasonic transducer may be configured to provide a substantially uniform acoustic pressure wave along the length of the lesion.

[0020] In another example, the catheter may comprise a catheter shaft, an expandable member fixed to the distal portion of the catheter shaft, a plurality of incision members fixed to the expandable member, an emitter shaft, an ultrasonic transducer disposed on the emitter shaft and within the expandable member, and a plurality of tethers extending from the emitter shaft to the expandable member.

[0021] Instead of, or in addition to, any of the above examples, in another example, each of the plurality of tethers may include a filament. Instead of, or in addition to, any of the above examples, in another example, each of the plurality of tethers may include a planar sheet of material.

[0022] Instead of, or in addition to, any of the above examples, in another example, a plurality of tethers may be configured to rotate the emitter shaft about the longitudinal axis of the emitter shaft as the expandable member is expanded.

[0023] Instead of, or in addition to, any of the above examples, in another example, a plurality of tethers may be configured to rotate the emitter shaft to orient the ultrasonic transducer toward the lesion.

[0024] Instead of, or in addition to, any of the above examples, in another example, a plurality of tethers may be uniformly distributed around the outer circumference of the emitter shaft. Instead of, or in addition to, any of the above examples, in another example, a plurality of tethers may include three tethers.

[0025] Instead of, or in addition to, any of the above examples, in another example, each of the plurality of tethers may be circumferentially offset from a plurality of incision members. Instead of, or in addition to, any of the above examples, in another example, at least one of the plurality of incision members may be configured to score a lesion while the ultrasonic transducer delivers a sound pressure wave to the lesion.

[0026] The above summary of some exemplary embodiments is not intended to describe every disclosed embodiment or every implementation of the present invention. The present invention may be more fully understood by considering the following detailed description of various embodiments in connection with the accompanying drawings.

Brief Description of the Drawings

[0027]

Figure 1A

Figure 1B

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DETAILED DESCRIPTION OF THE INVENTION

[0028] Although the present invention is applicable to various modified and alternative forms, details thereof are shown by way of example in the drawings and will be described in detail. However, it should be understood that the intention is not to limit the aspects of the present invention to the specific embodiments described. In contrast, the intention is to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present invention.

[0029] For the terms defined below, these definitions shall apply unless different definitions are given in the claims or elsewhere in this specification. All numerical values are assumed, in this specification, whether explicitly indicated or not, to be modified by the term "about". The term "about" generally refers to a range of numerical values that a person skilled in the art would consider equivalent to the recited value (i.e., having the same function or result). In many cases, the term "about" may be shown to include numbers rounded to the nearest significant digit.

[0030] The recitation of numerical ranges by endpoints includes all numerical values within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although some suitable dimensions, ranges, and / or values for various components, features, and / or specifications are disclosed, those skilled in the art triggered by this disclosure will understand that the desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0031] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or" unless the context clearly dictates otherwise.

[0032] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The detailed description and the drawings are not necessarily to scale and are illustrative of exemplary embodiments and are not intended to limit the scope of the invention. The illustrated exemplary embodiments are intended only as examples. Selected features of any exemplary embodiment can be incorporated into additional embodiments unless specifically stated to the contrary.

[0033] Many patients suffer from occluded arteries, other blood vessels, and / or occluded ducts or other body lumens that can restrict the flow of bodily fluids (e.g., blood, bile, etc.). The occlusion can be a partial occlusion that reduces blood flow through the occluded portion of the blood vessel, or a complete occlusion (e.g., chronic total occlusion) that substantially blocks blood flow through the occluded blood vessel. Vascular regeneration techniques involve using various devices to create or expand an opening through the occlusion. In some cases, lesions such as calcified lesions can pose problems for vascular regeneration techniques, and it may be beneficial to treat the calcified lesions to modify their compliance and allow for complete dilation prior to stent placement.

[0034] In some cases, for example, ultrasound can be used to treat vascular lesions such as fibrous and calcified lesions in various disease progression states where the ultrasound extends from soft plaques to highly calcified lesions. Vascular lesions that may be suitable for treatment using an ultrasound-based device include irregular highly calcified plaques located within and adjacent to the vessel wall, and lesions that are more or less rigid and thus may be susceptible to mechanical fatigue leading to failure. For example, an acoustic-based device can be used to generate a standing wave pressure pattern within the thickness of the lesion, a bending moment at the end of the lesion, and / or a resonance along the length of the lesion. In some cases, the high-frequency mechanical action of ultrasound may also be effective in treating earlier-stage vascular lesions, including fibrous and soft plaques. In some cases, an ultrasound device can apply non-focused near-field ultrasound treatment to treat vascular lesions. However, the effectiveness of ultrasound treatment for eccentric calcified lesions may be reduced compared to lesions that extend across the entire circumference of the vessel. For example, ultrasound or shock waves can be emitted from ultrasound transducers that are approximately 180° opposite each other. If the emitted shock wave is not aligned with the lesion, the shock wave may not be able to fragment or transform the lesion. The user has little or no control over the circumferential orientation of the emitter. It may be desirable to provide a device or system that self-orients the emitter towards the calcified lesion. Although the devices or systems described herein are described with respect to vascular lesions, it is to be understood that the devices or systems can also be used in other applications, including but not limited to non-vascular applications such as the treatment of peripheral calcified lesions, aortic valves, mitral valves, or tumors. For example, the methods and systems described herein can be used within any conduit that requires aiming or directing an emitter. The conduit may include compliance differences due to lesions, tumors, etc. It is contemplated that the devices and systems described herein can orient the emitter towards the peripheral lesion or tumor and away from adjacent organs.

[0035] FIG. 1A is a partial cross-sectional side view of an exemplary catheter 10 that may be used to treat a lesion disposed within blood vessel 12 and positioned adjacent to intravascular lesion 14. Catheter 10 may be configured to incise or score lesion 14 and emit shock waves or an ultrasonic field. It is contemplated that the combination of ultrasonic energy and the incision or scoring element may encompass a wider circumferential area than either alone. This may improve the effectiveness of treatment, particularly in lesions with a low circumferential angle of calcification (e.g., where the lesion extends less than around the entire circumference of blood vessel 12).

[0036] Catheter 10 may include a balloon 16 coupled to a catheter shaft 18. One or more incision members or blades 20 may be mounted on or above balloon 16. Incision member 20 may be an incision blade as shown in FIG. 1A or a scoring member as shown in FIG. 1B. Generally, catheter 10 may be advanced over guidewire 22 through the vasculature to the target area with balloon 16 in a folded or deflated configuration. When positioned at the target site within the vasculature, balloon 16 may be inflated to exert a radially outward force on lesion 14 and incision member 20 may engage lesion 14. Thus, incision member 20 may incise or score lesion 14 to facilitate expanding the proximal lumen of lesion 14. The target area may be within any suitable peripheral or cardiovascular lumen site.

[0037] The number, location, and arrangement of incision members 20 around balloon 16 may vary. For example, catheter 10 may include one, two, three, four, five, six, or more incision or scoring members 20 disposed in a regular, irregular, or any other suitable pattern at any position along balloon 16. For example, in some embodiments, balloon 16 may include a plurality of incision members 20 that extend longitudinally along the length of balloon 16 and are symmetrically disposed around the outer circumference of balloon 16. This is merely an example.

[0038] The incision member 20 can be made of any suitable material such as metal, metal alloy, polymer, metal-polymer composite, and the like, or any other suitable material. For example, in some cases, the incision member 20 can be made of stainless steel, titanium, nickel-titanium alloy, tantalum, iron-cobalt-nickel alloy, or other metallic materials.

[0039] The balloon 16 can be made from 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, and the like thereof.

[0040] The balloon 16 can be configured such that when the balloon 16 is deflated, the balloon 16 includes one or more "wings" or wing-like regions. In some cases, the wings can be configured such that the incision member 20 is positioned in the innermost position of the deflated balloon 16 with the incision member 20 wrapped under the wings of the balloon 16. This arrangement can reduce the exposure of the incision member 20 to the blood vessel during delivery of the balloon 16 to the lesion 14. Other configurations can also be used as desired.

[0041] 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 and outer tubular members 24, 26 can be fabricated from a number of different materials. For example, the inner and outer tubular members 24, 26 can be made of metal, metal alloy, polymer, metal-polymer composite, or any other suitable material.

[0042] The inner and outer tubular members 24, 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 and outer tubular members 24, 26 may or may not be fixed to each other along the 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 and outer tubular members 24, 26 can be arranged in another desired manner. In some embodiments, the inner tubular member 24 is torque-applicable and can rotate independently of the outer tubular member 26 to rotate the lithotripter emitter or ultrasonic transducer 38. For example, the inner tubular member 24 can include an embedded reinforcement member 50. For example, the inner tubular member 24 can include an embedded coil or braided member. Alternatively, or additionally, the outer tubular member 26 can be torque-applicable (e.g., including an embedded braided or coil reinforcement member) to facilitate rotating the entire device 10 within the vasculature before or between inflations.

[0043] The inner tubular member 24 can include an inner lumen 30. In at least some embodiments, the inner lumen 30 is a guidewire lumen for receiving the guidewire 22 therethrough. Thus, the catheter 10 can be advanced over the guidewire 22 to a desired site. The guidewire lumen 30 can extend essentially along the entire length of the catheter shaft 18, and for this reason, the catheter 10 resembles a conventional "over-the-wire" catheter. Alternatively, the guidewire lumen 30 can extend along only a portion of the catheter shaft 18, and for this reason, the catheter 10 resembles a "single-operator exchange" or "rapid exchange" catheter.

[0044] The catheter shaft 18 may also include an inflation lumen 32 that is used, for example, to transport inflation medium to and from the balloon 16 in order to selectively inflate and / or deflate the balloon 16. The location and position of the inflation lumen 32 may vary depending on the configuration of the inner and outer tubular members 24, 26. For example, when the outer tubular member 26 surrounds the inner tubular member 24, the inflation lumen 32 may be defined within the space between the outer tubular member 26 and the inner tubular member 24. In embodiments where the outer tubular member 26 is disposed in parallel with the inner tubular member 24, at this time, the inflation lumen 32 may be the lumen of the outer tubular member 26.

[0045] The balloon 16 may be coupled to the catheter shaft 18 in any of a number of suitable ways. For example, the balloon 16 may be adhesively or thermally joined to the catheter shaft 18. In some embodiments, the proximal constriction 34 of the balloon 16 may be joined to the catheter shaft 18, for example, to the distal end of the outer tubular member 26, and the distal constriction 36 of the balloon 16 may be joined to the catheter shaft 18, for example, to the distal end of the inner tubular member 24. However, the exact joining location may vary.

[0046] The inner tubular member 24 may include an ultrasonic transducer or emitter 38. The ultrasonic transducer 38 may be coupled adjacent its distal portion to the outer surface of the inner tubular member 24 such that the ultrasonic transducer is disposed within the balloon 16. In some cases, the ultrasonic transducer 38 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 38 may be driven at one or more frequencies within the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 38 may be a single ultrasonic transducer, or the ultrasonic transducer 38 may include a series of ultrasonic transducers that are operated to effectively function as a single ultrasonic transducer that provides a desired acoustic pressure across the desired treatment area. The applied acoustic pressure may range from dozens of kilopascals (kPa) to over 10 megapascals (MPa).

[0047] The ultrasonic transducer 38 can generate an ultrasonic field 40 including a near-field region and a far-field region. Within the near-field region, a dynamic sound pressure can be periodically applied to the calcified lesion 14. As used herein, the near-field region refers to a region very close radially to the surface of the ultrasonic transducer 38, for example, a region extending outwardly from the transducer surface to a radial distance less than or equal to the length of the ultrasonic transducer 38. The sound pressure wave transmitted by the ultrasonic transducer 38 does not converge and can be controlled to be substantially uniform over the calcified lesion 14. The ultrasonic transducer 38 can be configured to emit ultrasonic waves in two opposite directions or approximately 180° apart.

[0048] In some cases, for example, the ultrasonic transducer 38 can be configured to provide a uniform or substantially uniform sound pressure along the length of the calcified lesion 14. In a cardiovascular disease state, the vascular lesion can extend along a length of about 10 millimeters (mm) to about 25 mm within a blood vessel having a diameter of about 2 mm to about 4 mm. In a peripheral vascular disease state, the vascular lesion can extend along a length of up to about 200 mm within a blood vessel having a maximum diameter of about 12 mm. Depending on the treatment application, the ultrasonic transducer 38 can be configured to provide a uniform or substantially uniform sound 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 the central axis extending through the catheter shaft 18. Although not explicitly shown, multiple ultrasonic transducers 38 may be used and configured to extend the effective treatment length, for example, to a length of up to about 200 mm.

[0049] To provide a uniform or substantially uniform sound pressure within the near field, the ultrasonic transducer 38 can have a length that is several times larger than the diameter of the inner tubular member 24 and / or the outer tubular member 26. In some cases, the ultrasonic transducer 38 can have a length that is at least as long as the length of the calcified lesion 14 to generate a uniform or substantially uniform sound pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 38 can be a single ultrasonic transducer, or a series of ultrasonic transducers or transducer elements that are driven in a manner that effectively functions as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 38 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 using 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 such that amplitude and phase control can be applied to increase the uniformity of the sound pressure applied to the lesion 14.

[0050] Balloon 16 can be inflated using any suitable inflation fluid. Exemplary 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 based on how acoustic energy propagates through the inflation fluid. It will be understood that by selecting the particular fluid used to inflate balloon 16, the efficiency of acoustic energy transmission to calcified lesion 14 through the fluid can be controlled. In one example, the inflation fluid can be selected to have a particular acoustic impedance to serve as an acoustic match between ultrasonic transducer 38 and vessel wall 12. In another example, the inflation fluid can be selected to have a particular acoustic impedance to serve as an acoustic match to minimize transmission loss across the wall of inflatable balloon 16. In another example, the inflation fluid can be selected to have a particular speed of sound to alter the near-field behavior of ultrasonic transducer 38.

[0051] Figure 1B is a perspective view of an exemplary scoring cage 60 that can be used in addition to, instead of the incision member 20 shown and described in Figure 1A. The scoring cage 60 can extend from a first or proximal end 62 to a second or distal end 64. The proximal end 62 can include a proximal flange or proximal tubular member 66. The proximal flange 66 can be configured to be disposed adjacent to or proximal to the proximal constriction 34 of the balloon 16 and to cover the outer tubular member 26. In some cases, the proximal flange 66 can be fixed to the outer surface of the outer tubular member 26. In other embodiments, the proximal flange 66 can be slidably disposed over the outer tubular member 26. The distal end 64 can include a distal flange or distal tubular member 68. The distal flange 68 can be configured to be disposed adjacent to or distal to the distal constriction 36 of the balloon 16 and to cover the inner tubular member 24. In some cases, the distal flange 68 can be fixed to the outer surface of the inner tubular member 24. The scoring cage 60 can further include one or more longitudinally extending wires 70a, 70b, 70c, 70d (collectively, 70) that extend between the proximal flange 66 and the distal flange 68. The longitudinally extending wires 70 can be positioned along the outer surface of the balloon 16. As the balloon 16 expands, the wires 70 can be pushed into the lesion 14 to score the lesion 14. The scoring cage 60 is shown as including four wires 70, but the scoring cage 60 can include fewer than four or more than four wires 70, as desired. Further, the wires 70 can be spaced evenly or eccentrically around the outer periphery of the balloon 16, as desired.

[0052] With additional reference to FIG. 2, which shows a cross-sectional view of balloon 16, as balloon 16 expands in a target region (e.g., adjacent to lesion 14), cutting member 20 delivers amplified force generated by balloon pressure to lesion 14 to create a controlled longitudinal crack within lesion 14. In some cases, the anchored cutting member 20 can supplement the force at balloon contact point 42, which may be required to propagate the crack at a lower pressure while reducing vessel trauma. In addition to cutting member 20 penetrating lesion 14, ultrasonic transducer 38 can be actuated to generate ultrasonic field 40. Ultrasonic transducer 38 is positioned such that ultrasonic field 40 is aligned with the force amplification zone of cutting member 20 and balloon 16 (e.g., cutting member 20 and / or balloon contact point 42) to combine two energy modalities and concentrate them at the same spot. For example, during assembly, ultrasonic transducer 38 can be positioned on inner tubular member 24 to align the generated ultrasonic field 40 with at least one cutting member 20. When lesion 14 is asymmetric and extends less than around the entire circumference of vessel 12, the portion of vessel 12 without lesion 14 can be more extensible and stretch more as the balloon expands. It is contemplated that the anchoring effect of cutting member 20 can also stabilize the extensible side of vessel 12, which can in turn increase the effectiveness of ultrasonic field 40.

[0053] FIG. 3 is a partial cross-sectional side view of another exemplary catheter 100 that can be disposed within vessel 102 and positioned adjacent to intravascular lesion 104 for use in treating the lesion. Catheter 100 can be configured to cut or score lesion 104 and emit shock waves or an ultrasonic field. It is contemplated that the combination of ultrasonic energy and the cutting or scoring element can cover a wider circumferential area than either alone. This can improve the effectiveness of treatment, particularly in lesions with a low circumferential angle of calcification (e.g., where the lesion extends less than around the entire circumference of vessel 102).

[0054] Catheter 100 may include a balloon 106 coupled to a catheter shaft 108. One or more incision members or blades 110 may be mounted on the balloon 106. The incision member 110 may be an incision blade or a scoring member. Generally, the catheter 100 can be advanced over a guidewire 112 through the vasculature to a target region with the balloon 106 in a folded or collapsed configuration. Once positioned at the target site within the vasculature, the balloon 106 can be inflated to exert a radially outward force on the lesion 104, and the incision member 110 can engage the lesion 104. Thus, the incision member 110 can incise or score the lesion 104 to facilitate expanding the lumen proximal to the lesion 104. The target region can be within any suitable peripheral or cardiovascular lumen site.

[0055] The incision members 110 may vary in number, position, and arrangement around the balloon 106. For example, the catheter 100 can include one, two, three, four, five, six, or more incision members 110 disposed in a regular, irregular, or any other suitable pattern at any position along the balloon 106. For example, in some embodiments, the balloon 106 can include a plurality of incision members 110 that extend longitudinally along the length of the balloon 106 and are symmetrically disposed around the outer periphery of the balloon 106. This is merely an example.

[0056] The incision members 110 can be made of any suitable material such as metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material. For example, in some cases, the incision members 110 can be made of stainless steel, titanium, nickel-titanium alloy, tantalum, iron-cobalt-nickel alloy, or other metallic materials.

[0057] Balloon 106 can be made from 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, and the like thereof.

[0058] Balloon 106 can be configured to include one or more "wings" or wing-like regions when balloon 106 is deflated. In some cases, the wings can be configured such that cutting member 110 can be positioned at the innermost position of deflated balloon 106 with cutting member 110 wrapped under the wings of balloon 106. This arrangement can reduce the exposure of cutting member 110 to the blood vessel during delivery of balloon 106 to lesion 104. Other configurations can also be used as desired.

[0059] Shaft 108 can be a catheter shaft similar to a typical catheter shaft. For example, catheter shaft 108 can include an outer tubular member 116 and an inner tubular member 114 extending through at least a portion of outer tubular member 116. Inner and outer tubular members 114, 116 can be fabricated from a number of different materials. For example, inner and outer tubular members 114, 116 can be made of metal, metal alloy, polymer, metal-polymer composite, or any other suitable material.

[0060] The inner and outer tubular members 114, 116 can be arranged in any suitable manner. For example, in some embodiments, the inner tubular member 114 can be coaxially disposed within the outer tubular member 116. According to these embodiments, the inner and outer tubular members 114, 116 may or may not be fixed to each other along the longitudinal axis of the catheter shaft 108. Alternatively, the inner tubular member 114 can be disposed along the inner wall or, otherwise, adjacent to the inner wall of the outer tubular member 116. In other embodiments, the inner and outer tubular members 114, 116 can be arranged in another desired manner.

[0061] The inner tubular member 114 can include an inner lumen 120. In at least some embodiments, the inner lumen 120 is a guide wire lumen for receiving a guide wire (not explicitly shown) therethrough. Thus, the catheter 100 can be advanced over the guide wire to a desired site. The guide wire lumen 120 can extend essentially along the entire length of the catheter shaft 108, and for this reason, the catheter 100 is similar to a conventional "over-the-wire" catheter. Alternatively, the guide wire lumen 120 can extend along only a portion of the catheter shaft 108, and for this reason, the catheter 100 is similar to a "single operator exchange" or "rapid exchange" catheter.

[0062] The catheter shaft 108 can also include an inflation lumen 122 that can be used, for example, to transport an inflation medium to and from the balloon 106 to selectively inflate and / or deflate the balloon 106. The location and position of the inflation lumen 122 can vary depending on the configuration of the inner and outer tubular members 114, 116. For example, when the outer tubular member 116 surrounds the inner tubular member 114, the inflation lumen 122 can be defined within the space between the outer tubular member 116 and the inner tubular member 114. In embodiments where the outer tubular member 116 is disposed in parallel with the inner tubular member 114, the inflation lumen 122 can, at this time, be the lumen of the outer tubular member 116.

[0063] The balloon 106 can be coupled to the catheter shaft 108 in any of a number of suitable ways. For example, the balloon 106 can be adhesively or thermally joined to the catheter shaft 108. In some embodiments, the proximal constriction 124 of the balloon 106 can be joined to the catheter shaft 108, for example, to the distal end of the outer tubular member 116, and the distal constriction 126 of the balloon 106 can be joined to the catheter shaft 108, for example, to the distal end of the inner tubular member 114. However, the exact joining locations can vary.

[0064] The emitter shaft 118 can be disposed within the guidewire lumen 120. Although the emitter shaft 118 is shown within the guidewire lumen 120, the emitter shaft 118 can alternatively be disposed within the inflation lumen 122. The emitter shaft 118 can be fabricated from a number of different materials. For example, the emitter shaft 118 can be made of metal, metal alloy, polymer, metal-polymer composite, or any other suitable material. In some cases, the emitter shaft 118 can be translated longitudinally and / or rotated within the respective lumens 120, 122. In some embodiments, the emitter shaft 118 can include or be formed from a reinforcing member 119, such as, but not limited to, a coil or braid, to enable torque application.

[0065] The emitter shaft 118 may include an ultrasonic transducer or emitter 128 positioned adjacent to its distal end region 132. During the procedure, the emitter shaft 118 may be positioned such that the ultrasonic transducer 128 is disposed within the balloon 106 so as to be generally aligned with the incision member 110. The ultrasonic transducer 128 may be coupled to the outer surface of the emitter shaft 118. In some cases, the ultrasonic transducer 128 may include a piezoelectric material that transmits a sound pressure in response to an applied voltage. The ultrasonic transducer 128 may be driven at one or more frequencies within the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 128 may be a single ultrasonic transducer, or the ultrasonic transducer 128 may include a series of ultrasonic transducers that are operated so as to effectively function as a single ultrasonic transducer that provides a desired sound pressure across the desired treatment area. The applied sound pressure may range from several tens of kilopascals (kPa) to over 10 megapascals (MPa).

[0066] The ultrasonic transducer 128 may generate an ultrasonic field 130 that includes a near-field region and a far-field region. Within the near-field region, a dynamic sound pressure may be periodically applied to the calcified lesion 104. As used herein, the near-field region refers to a region that is radially very close to the surface of the ultrasonic transducer 128, for example, a region that extends outwardly from the transducer surface to a radial distance that is less than or equal to the length of the ultrasonic transducer 128. The sound pressure waves transmitted by the ultrasonic transducer 128 do not converge and may be controlled to be substantially uniform over the calcified lesion 104. The ultrasonic transducer 128 may be configured to emit ultrasonic waves in two opposite directions or at approximately 180° apart.

[0067] In some cases, for example, the ultrasonic transducer 128 can be configured to provide a uniform or substantially uniform acoustic pressure wave along the length of the calcified lesion 104. In a cardiovascular disease state, the vascular lesion can extend in length from about 10 millimeters (mm) to about 25 mm within a blood vessel having a diameter of about 2 mm to about 4 mm. In a peripheral vascular disease state, the vascular lesion can extend in length up to about 200 mm within a blood vessel having a maximum diameter of about 12 mm. Depending on the treatment application, the ultrasonic transducer 128 can be configured to provide a uniform or substantially uniform acoustic pressure over a length from about 10 mm to about 60 mm at a radial distance from about 1 mm to about 8 mm when measured from the central axis extending through the catheter shaft 108. Although not explicitly shown, multiple ultrasonic transducers 128 may be used and configured to extend the effective treatment length, for example, to a length of up to 200 mm.

[0068] To provide a uniform or substantially uniform acoustic pressure within the near field, the ultrasonic transducer 128 can have a length that is multiple times larger than the diameter of the emitter shaft 118 and / or the outer tubular member 116. In some cases, the ultrasonic transducer 128 can have a length that is at least as long as the length of the calcified lesion 104 to generate a uniform or substantially uniform acoustic pressure over a length from about 20 to about 80 mm. In some cases, the ultrasonic transducer 128 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements driven in a manner that effectively functions as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 128 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 using 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 such that amplitude and phase control can be applied to increase the uniformity of the acoustic pressure applied to the lesion 104.

[0069] Balloon 106 can be inflated using any suitable inflation fluid. Exemplary 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 based on how acoustic energy propagates through the inflation fluid. It will be understood that by selecting the particular fluid used to inflate balloon 106, the efficiency of acoustic energy transmission to calcified lesion 104 through the fluid can be controlled. In one example, the inflation fluid can be selected to have a particular acoustic impedance to serve as an acoustic match between ultrasonic transducer 128 and vessel wall 102. In another example, the inflation fluid can be selected to have a particular acoustic impedance to serve as an acoustic match to minimize transmission loss across the wall of inflatable balloon 106. In another example, the inflation fluid can be selected to have a particular speed of sound to alter the near-field behavior of ultrasonic transducer 128.

[0070] Referring additionally to FIG. 4, which shows a cross-sectional view of balloon 106, as balloon 106 expands in a target region (e.g., adjacent to lesion 104), incision member 110 delivers amplified force generated by balloon pressure to lesion 104 to create a controlled longitudinal crack within lesion 104. In some cases, the anchored incision member 110 may supplement the force at balloon contact point 134, which may be required to propagate the crack at a lower pressure while reducing vessel trauma. In addition to incision member 110 penetrating into lesion 104, ultrasonic transducer 128 may be actuated to generate an ultrasonic field 130. It is contemplated that ultrasonic transducer 128 may be positioned such that ultrasonic field 130 is aligned with the force amplification zone of incision member 110 and balloon 106 (e.g., incision member 110 and / or balloon contact point) to combine two energy modalities and focus them at the same spot. For example, during assembly, ultrasonic transducer 128 may be positioned to align with at least one incision member 110. When lesion 104 is asymmetric and extends over less than the entire circumference of vessel 102, the portion of vessel 102 without lesion 104 may be more stretchable and may stretch more in response to balloon expansion. It is contemplated that the anchoring effect of incision member 110 may also stabilize the stretchable side of vessel 102, which in turn may increase the effectiveness of ultrasonic field 130.

[0071] When balloon 106 is inflated to anchor within blood vessel 102, ultrasonic transducer 128 can deliver a desired amount of energy. In some cases, the original orientation of ultrasonic transducer 128, and thus ultrasonic field 130, may not align well with lesion 104 to be fragmented, as shown in FIG. 4. When energy is delivered, emitter shaft 118 can be rotated, and as shown in FIG. 5, the energy can be redelivered to different segments of the circumference of blood vessel 102. It is contemplated that emitter shaft 118 can be gradually rotated until an optimal orientation is achieved to crack lesion 104. In some cases, emitter shaft 118 can be rotated in increments of 90 degrees or less. The proximal end region of emitter shaft 118 can include a marker or other visual indicia to indicate how much emitter shaft 118 has been rotated relative to its initial orientation.

[0072] In some embodiments, the difference in vascular compliance due to the eccentric lesion 104 can cause non-uniform expansion of the balloon 106. For example, the balloon 106 can have an inflated size and shape that vary with the inflation pressure and the compliance of the blood vessel 102. In one example, the balloon 106 can expand more on the side opposite the inextensible calcified lesion 104, as shown in FIGS. 4 and 5. It is contemplated that the non-uniform expansion of the balloon 106 can be utilized to orient the ultrasonic transducer 128 towards the lesion 104. FIG. 6 is another cross-sectional view of the balloon 106 disposed within the blood vessel 102 having the eccentric lesion 104, in a folded or collapsed state, and including additional features that automatically orient the ultrasonic transducer 128 towards the inextensible lesion. The balloon 106 can further include a plurality of tethers 140a, 140b, 140c (collectively, 140) extending from a first end 142a, 142b, 142c (collectively, 142) coupled or fixed to the emitter shaft 118, and a second end 144a, 144b, 144c (collectively, 144) coupled or fixed to the balloon 106 or the incision member 110. FIG. 7 is a cross-sectional view of the balloon of FIG. 6 in an inflated configuration. The non-uniform expansion of the balloon 106 towards the extensible side of the blood vessel pulls the tether 140 on that side more than the tether 140 on the inextensible side (e.g., towards the lesion 104), automatically rotating or orienting the ultrasonic transducer 128 towards the inextensible calcified lesion 104.

[0073] In some embodiments, each tether 140 can be a string, filament, or a plurality of strings or filaments that are integrally woven or wound. In other embodiments, the tether 140 can be a planar material sheet having a length that extends generally parallel to the longitudinal axis of the emitter shaft 118 and a width that extends between the outer surface of the emitter shaft 118 and the inner surface of the balloon 106. In yet other embodiments, the tether 140 can be a magnet or formed from a magnetic material. The tether 140 can be formed from a material that resists stretching. The tether 140 can be spaced evenly or eccentrically around the outer periphery of the emitter shaft 118. In some cases, the tether 140 can be circumferentially positioned between the cutting members 110, but this is not essential. It is further contemplated that the tether 140 can be positioned at similar or different longitudinal locations of the emitter shaft 118, as desired. Although three tethers 140 are shown, it is contemplated that there can be fewer than three or more than three tethers, as desired.

[0074] Next, referring to FIG. 7, as balloon 106 is inflated, balloon 106 can expand more on the side of blood vessel 102 without lesion 104. As balloon 106 inflates, on the side opposite lesion 104, blood vessel 102 is more extensible and balloon 106 expands to a greater extent, so the second ends 144a, 144b of the first and second tethers 140a, 140b are pulled farther away from emitter shaft 118. As the second ends 144a, 144b are radially separated, the first and second tethers 140a, 140b cause rotation of emitter shaft 118. For example, in the contracted configuration shown in FIG. 6, ultrasonic transducer 128 is oriented to emit ultrasonic energy 130 in a first orientation, in a direction away from calcified lesion 104, as indicated by arrow 150. As balloon 106 is inflated, tethers 140a, 140b on the non-calcified side of balloon 106 are placed under greater strain than tether 140c on the calcified side of balloon 106. The increased strain in the first and second tethers 140a, 140b causes rotation of emitter shaft 118, whereby ultrasonic transducer 128 is oriented to emit ultrasonic energy 130 in a second orientation, toward calcified lesion 104, as shown by arrow 152 in FIG. 7. The second orientation can direct ultrasonic energy 130 toward lesion 104. Stated another way, tether 140 can self-align ultrasonic transducer 128 with non-extensible target lesion 104 as balloon 106 is inflated. It is further contemplated that tether 140 can stabilize ultrasonic transducer 128 within balloon 106 for further effectiveness. In some cases, incision member 110 opposite lesion 104 can retroreflect ultrasonic energy toward lesion 104, further improving effectiveness. Incision member 110 can function as an anchor to promote tether force on ultrasonic transducer 128 and thus stabilize balloon 106 to allow rotation.

[0075] In some embodiments, instead of an inflatable balloon, an expandable metal or polymer frame may be used to anchor, apply force to the lesion, and non-uniformly expand according to the difference in compliance within the blood vessel to self-align the emitter towards the target tissue. FIG. 8 shows a side view of another exemplary catheter 200 that can be used to treat a lesion disposed within blood vessel 202 and positioned adjacent to an intravascular lesion 204. The catheter 200 can be configured to incise or score the lesion 204 and emit a shock wave or ultrasonic field. It is contemplated that the combination of ultrasonic energy and the incision or scoring element may cover a wider circumferential area than either alone. This can improve the effectiveness of treatment, particularly in lesions with a low circumferential angle of calcification (e.g., where the lesion extends less than the full circumference of the blood vessel 202).

[0076] The catheter 200 may include an expandable basket 206 coupled to a catheter shaft 208. The shaft 208 can be an outer tubular member or catheter shaft similar to a typical catheter shaft. For example, the catheter shaft 208 can be a tubular member extending from a distal end region 212 to a proximal end region (not explicitly shown) configured to remain outside the patient's body. A lumen 214 can extend from the distal end region 212 to the proximal end region.

[0077] Catheter 200 may further include an inner tubular member 216 that may be slidably disposed within the lumen 214 of catheter shaft 208. At least a portion of the expandable basket 206 may be coupled to the distal end region 230 of the elongate shaft 216. The catheter shaft 208 and the inner tubular member 216 may be fabricated from a number of different materials. For example, the catheter shaft 208 and the inner tubular member 216 may be made of metal, metal alloy, polymer, metal-polymer composite, or any other suitable material. An emitter shaft 232 may be disposed within the lumen 234 of the inner tubular member 216. Although the emitter shaft 232 is shown within the lumen 234 of the inner tubular member, the emitter shaft 232 may alternatively be disposed within the lumen 214 of the elongate shaft 208. The emitter shaft 232 may be fabricated from a number of different materials. For example, the emitter shaft 232 may be made of metal, metal alloy, polymer, metal-polymer composite, or any other suitable material. In some cases, the emitter shaft 232 may be translated longitudinally and / or may be rotatable within respective lumens 214, 234. In some embodiments, the emitter shaft 232 may include or be formed from a reinforcing member, such as, but not limited to, a coil or braid, to enable torque application.

[0078] The expandable basket 206 can be configured to transition between a folded configuration and an expanded configuration (FIG. 8). The expandable basket 206 can include a number of expandable positioning elements, such as longitudinally extending struts 218a, 218b (collectively 218), which can be coupled to the inner tubular member 216 at their proximal ends 220a, 220b (collectively, 220). The distal ends 222a, 222b of the struts 218 can be coupled to the caps 236. In some cases, the caps 236 can include spacers that are used to maintain a consistent spacing between each of the struts 218. However, this is not essential. In some cases, the struts 218 can be disposed eccentrically. The struts 218 can generally be configured to extend along the longitudinal axis of the catheter shaft 208. The expandable basket 206 is shown as including two longitudinally extending struts 218, but the expandable basket 206 can include any desired number of struts 218, such as, but not limited to, one, two, three, four, five, six, or more. Other suitable expandable positioning elements can also be utilized, such as, but not limited to, rods or bars, a single hypotube with portions removed to form struts, expandable stents with proximal and / or distal ends integrally gathered (e.g., woven, knitted, laser cut, etc.), or the like.

[0079] The expandable basket 206 may be self-expandable or may require an external force to expand from a folded state. The self-expanding 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-expanding material. When such a shape memory material is employed, the expandable basket 206 may be heat set in the expanded state and then compressed to fit, for example, within the catheter shaft 208 and / or the inner tubular member 216. In another embodiment, a spring may be provided to cause expansion. Alternatively, an external force such as, but not limited to, a pneumatic method, a compressed fluid, a pull wire, a push wire, or the like may also be employed to expand the expandable basket 206. It is contemplated that a nickel-titanium alloy may enable kink-resistant folding and self-expansion. In other examples, magnetic alloys, metals, metal alloys, polymers, composites, etc. may be used to form the expandable basket 206.

[0080] In other cases, a manual force applied to the inner tubular member 216 may operate or actuate the expandable basket 206 between the expanded and folded states. For example, the actuation element may include a central wire extending through the expandable basket 206. According to this embodiment, a tensile force exerted proximally on the wire may enable the strut 218 to expand the expandable basket 206 and move it to the expanded state. A compressive force exerted distally on the wire may move the strut 218 to extend and / or otherwise transition the ablation device to a compressed or expanded state. Other actuation mechanisms may also be utilized.

[0081] As described above, the expandable basket 206 can include a number of expandable positioning elements, such as struts 218 that extend longitudinally. Each strut can extend from a proximal end region 220 to a distal end region 222. Intermediate regions 224a, 224b (collectively, 224) can be disposed between the proximal end region 220 and the distal end region 222. In the expanded state, it is contemplated that the intermediate region 224 of the strut 218 can contact the vessel wall 202.

[0082] One or more incision members or blades 210 can be mounted on or above the expandable basket 206. For example, one or more incision members 210 can be coupled to the intermediate region 224 of the strut 218. The incision member 210 can be an incision blade, or a scoring member (see, e.g., FIG. 1B), as shown in FIG. 8. Generally, the catheter 200 can be advanced through the vasculature to a target region with the expandable basket 206 in a collapsed configuration. When positioned at a target site within the vasculature, the expandable basket 206 can be expanded to exert a radially outward force on the lesion 204, and one or more of the incision members 210 can engage the lesion 204. Thus, the incision member 210 can incise or score the lesion 204 to facilitate expanding the lumen proximal to the lesion 204. The target region can be within any suitable peripheral or cardiovascular lumen site.

[0083] The emitter shaft 232 may include an ultrasonic transducer or emitter 226. The ultrasonic transducer 226 may be coupled to the outer surface of the emitter shaft 232 adjacent to its distal portion. During the procedure, the emitter shaft 232 may be positioned within the basket 206 such that the ultrasonic transducer 226 is generally aligned with the incision member 210. For example, the emitter shaft 232 may be axially and rotatably movable relative to the inner tubular member 216. In some cases, the ultrasonic transducer 226 may include a piezoelectric material that transmits a sound pressure in response to an applied voltage. The ultrasonic transducer 226 may be driven at one or more frequencies within the range of about 20 kilohertz (kHz) to about 50 megahertz (MHz). The ultrasonic transducer 226 may be a single ultrasonic transducer, or the ultrasonic transducer 226 may include a series of ultrasonic transducers that are operated to effectively function as a single ultrasonic transducer that provides a desired sound pressure across a desired treatment area. The applied sound pressure may range from several tens of kilopascals (kPa) to over 10 megapascals (MPa).

[0084] The ultrasonic transducer 226 may generate an ultrasonic field 228 that includes a near-field region and a far-field region. Within the near-field region, a dynamic sound pressure may be periodically applied to the calcified lesion 204. As used herein, the near-field region refers to a region that is radially very close to the surface of the ultrasonic transducer 226, for example, a region that extends outwardly from the transducer surface to a radial distance that is less than or equal to the length of the ultrasonic transducer 226. The sound pressure wave transmitted by the ultrasonic transducer 226 is not focused and may be controlled to be substantially uniform over the calcified lesion 204. The ultrasonic transducer 226 may be configured to emit ultrasonic waves in two opposite directions or at about 180° apart.

[0085] In some cases, for example, the ultrasonic transducer 226 can be configured to provide a uniform or substantially uniform sound pressure along the length of the calcified lesion 204. In a cardiovascular disease state, the vascular lesion can extend to a length of about 10 millimeters (mm) to about 25 mm within a blood vessel having a diameter of about 2 mm to about 4 mm. In a peripheral vascular disease state, the vascular lesion can extend to a length of up to about 200 mm within a blood vessel having a maximum diameter of about 12 mm. Depending on the treatment application, the ultrasonic transducer 226 can be configured to provide a uniform or substantially uniform sound 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 the central axis extending through the catheter shaft 208. Although not explicitly shown, a plurality of ultrasonic transducers 226 may be used and configured to extend the effective treatment length, for example, to a length of up to about 200 mm.

[0086] To provide a uniform or substantially uniform sound pressure within the near field, the ultrasonic transducer 226 can have a length that is a multiple of the diameter of the emitter shaft 232, the inner tubular member 216, and / or the catheter shaft 208. In some cases, the ultrasonic transducer 226 can have a length that is at least as long as the length of the calcified lesion 204 to generate a uniform or substantially uniform sound pressure over a length of about 20 to about 80 mm. In some cases, the ultrasonic transducer 226 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements driven in a manner that effectively functions as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 226 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 using 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 such that amplitude and phase control can be applied to increase the uniformity of the sound pressure applied to the lesion 204.

[0087] As the expandable basket 206 expands in the target region (e.g., adjacent to the lesion 204), the cutting member 210 delivers amplified force generated by balloon pressure to the lesion 204 to create a controlled longitudinal crack within the lesion 204. In some cases, the anchored cutting member 210 can supplement the force at the contact points of the basket 206 that may be required to propagate the crack at a lower pressure while reducing vessel trauma. In addition to the cutting member 210 penetrating the lesion 204, the ultrasonic transducer 226 can be actuated to generate an ultrasonic field 228. The ultrasonic transducer 226 is contemplated to be positioned such that the ultrasonic field 228 is aligned with the force amplification zone of the cutting member 210 and the expandable basket 206 (e.g., the cutting member 210 and / or the basket contact points) to combine two energy modalities and concentrate them at the same spot. For example, during insertion, the ultrasonic transducer 226 can be positioned to align the generated ultrasonic field 228 with at least one cutting member 210. When the lesion 204 is asymmetric and extends over less than the entire circumference of the blood vessel 202, the portion of the blood vessel 202 without the lesion 204 can be more extensible and can stretch more as the basket expands. It is contemplated that the anchoring effect of the cutting member 210 can also stabilize the extensible side of the blood vessel 202, which can in turn increase the effectiveness of the ultrasonic field 228.

[0088] In some embodiments, the expandable basket 206 further includes a plurality of tethers 236a, 236b, 236c, 236d (collectively, 236) extending from first ends 238a, 238b, 238c, 238d (collectively, 238) coupled or fixed to the emitter shaft 232, and second ends 240a, 240b, 240c, 240d (collectively, 240) coupled or fixed to the expandable basket 206 or the incision member 210. Generally, uneven expansion of the expandable basket 206 toward the stretchable side of the blood vessel pulls the tethers 236 on that side more strongly than the tethers 236 on the non-stretchable side (e.g., toward the lesion 204), automatically rotating or orienting the ultrasonic transducer 226 toward the non-stretchable calcified lesion 204.

[0089] In some embodiments, each tether 236 can be a string, filament, or a plurality of strings or filaments woven or wound together. In other embodiments, the tether 236 can be a planar sheet of material having a length extending generally parallel to the longitudinal axis of the emitter shaft 232 and a width extending between the outer surface of the emitter shaft 232 and the inner surface of the expandable basket 206. In still other embodiments, the tether 236 can be a magnet or formed from a magnetic material. The tether 236 can be formed from a material that resists stretching. The tethers 236 can be spaced evenly or eccentrically around the outer circumference of the emitter shaft 232. It is further contemplated that the tethers 236 can be positioned at similar or different longitudinal locations of the emitter shaft 232, as desired. Although four tethers 236 are shown, it is contemplated that there can be fewer or more than four tethers, as desired.

[0090] As the expandable basket 206 expands, the expandable basket 206 can expand more on the side of the vessel 202 without the lesion 204. As the expandable basket 206 expands, the vessel 202 is more extensible on the side opposite the lesion 204, and since the expandable basket 206 expands to a greater extent, the second ends 240a, 240b of the first and second tethers 236a, 236b are pulled farther away from the emitter shaft 232. As the second ends 240a, 240b are radially separated, the first and second tethers 236a, 236b cause rotation of the emitter shaft 232. In other words, as the expandable basket 206 is an example, the tethers 236a, 236b on the non-calcified side of the expandable basket 206 are placed under greater strain than the tethers 236c, 236d on the calcified side of the expandable basket 206. The increased strain in the first and second tethers 236a, 236b causes rotation of the emitter shaft 232, whereby the ultrasonic transducer 226 is oriented to emit ultrasonic energy 228 in an orientation towards the calcified lesion 204. This can direct the ultrasonic energy 228 towards the lesion 204. For example, the tether 236 can self-align the non-extensible target lesion 204 with the ultrasonic transducer 226 as the expandable basket 206 expands. It is further contemplated that the tether 236 can stabilize the ultrasonic transducer 226 within the expandable basket 206 for further effectiveness. In some cases, the incision member 210 opposite the lesion 204 can retroreflect ultrasonic energy towards the lesion 204, further improving effectiveness. The incision member 210 can function as an anchor to promote tethering forces to the ultrasonic transducer 226 and thus stabilize the expandable basket 206 to allow rotation.

[0091] The various components of the system(s) disclosed herein and the materials that can be used for the various elements thereof may include those commonly associated with medical devices. For purposes of simplicity, in the following description, the system is referred to. However, the description is not limited to, but may also be applicable to, other elements, members, components, or devices disclosed herein, such as, but not limited to, catheter shafts, inflatable balloons, cutting members, emitter shafts, etc., and / or their elements or components, etc., and is not intended to limit the devices and methods described herein.

[0092] In some embodiments, the system and / or its components may be made of metal, metal alloy, polymer (some examples of which are disclosed below), metal-polymer composite, ceramic, combinations thereof, etc., or other suitable materials.

[0093] Some examples of suitable polymers include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block ester, polyurethane (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., butylene / poly(alkylene ether) phthalate, and / or other polyester elastomers such as HYTREL® available from DuPont), polyamide (e.g., DURETHAN® available from Bayer or CRISTAMID™ available from Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block amide (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), MARLEX® high density polyethylene, MARLEX® low density polyethylene, linear low density polyethylene (e.g., REXELL™), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyether imide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon - 12 (e.g., EMS AmericanGRILAMID® available from Grilon, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, polyurethane silicone copolymer (e.g., ElastEon™ from Aortech Biomaterials or ChronoSil™ from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof, and the like can be mentioned. In some embodiments, the component can be blended with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6% LCP.

[0094] Some examples of suitable metals and metal alloys include stainless steels such as 304V, 304L, and 316LV stainless steel, mild 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 INCONEL® 625, UNS:N06022 such as HASTELLOY® C-22®, UNS:N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N™), nickel-molybdenum alloys (e.g., UNS:N10665 such as HASTELLOY® ALLOY B2®), 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 ELGILOY®, PHYNOX®, etc.), platinum-enriched stainless steel, titanium, platinum, palladium, gold, combinations thereof, or any other suitable material.

[0095] In at least some embodiments, some or all of the system and / or its components may also be doped with a radiopaque material, made of a radiopaque material, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can generate a relatively bright image on a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image helps the user of the system to determine its position. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of the system to achieve the same result.

[0096] 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 parts can be made of materials that do not substantially distort the image and do not create substantial artifacts (i.e., gaps within the image). For example, certain ferromagnetic materials may not be suitable as they can potentially create artifacts in the MRI image. The system or a part thereof may also be made of materials that can be imaged by an MRI device. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (such as UNS:R30003 like ELGILOY®, PHYNOX® etc.), nickel-cobalt-chromium-molybdenum alloys (such as UNS:R30035 like MP35-N™ etc.), nitinol, etc., and others.

[0097] In some embodiments, the systems and / or other elements disclosed herein may include a suitable therapeutic agent and / or may be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents include antithrombotic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrorphan proline arginine chloromethyl ketone)); growth inhibitors (such as enoxaparin, angiotensin, monoclonal antibodies capable of blocking smooth muscle cell growth, hirudin, and acetylsalicylic acid); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine); antitumor / anti-proliferative / anti-mitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vincristine, vinblastine, epothilone, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetics (such as lidocaine, bupivacaine, and ropivacaine); anticoagulants (such as D-Phe-Pro-Arg chloromethyl ketone, RGD peptide-containing compounds, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, anti-platelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick anti-platelet peptides); vasocyte growth promoters (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional activators, and translation promoters); vasocyte growth inhibitors (such as growth factor inhibitors, growth factor receptor antagonists, transcriptional inhibitors, translation inhibitors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of growth factors and cytotoxins, bifunctional molecules consisting of antibodies and cytotoxins); cholesterol-lowering agents; vasodilators; and agents that interfere with the endogenous vasomotor mechanism.

[0098] It should be understood that the present disclosure is merely illustrative in many respects. Without departing from the scope of the present disclosure, changes in details, particularly with regard to the shape, size, and configuration of the steps, can be made. This may include using any of the features of one exemplary embodiment in other embodiments within a suitable range. The scope of the present disclosure is, of course, defined by the language expressed in the appended claims.

Claims

**Claim 1** A catheter, comprising: a catheter shaft; an expandable member fixed to a distal portion of the catheter shaft; an incision member fixed to the expandable member; an ultrasonic transducer disposed within the expandable member. **Claim 2** The catheter according to claim 1, wherein the catheter shaft includes an inner tubular member defining a first lumen and an outer tubular member defining a second lumen. **Claim 3** The catheter according to claim 2, wherein the inner tubular member is torque-applicable. **Claim 4** The catheter according to claim 2 or 3, wherein the outer tubular member is torque-applicable. **Claim 5** The catheter according to any one of claims 1 to 4, wherein the expandable member includes an inflatable balloon. **Claim 6** The catheter according to any one of claims 1 to 4, wherein the expandable member includes an expandable cage. **Claim 7** The catheter according to any one of claims 2 to 6, wherein the ultrasonic transducer is attached to an outer surface of the inner tubular member. **Claim 8** The catheter according to any one of claims 1 to 6, further comprising an emitter shaft. **Claim 9** The catheter according to claim 8, wherein the ultrasonic transducer is attached to a distal portion of the emitter shaft. **Claim 10** The catheter according to claim 8 or 9, wherein the emitter shaft is rotatable relative to the catheter shaft. **Claim 11** The catheter according to any one of claims 8 to 10, further comprising a plurality of tethers extending from the emitter shaft to the expandable member. **Claim 12** The catheter according to claim 11, wherein each of the plurality of tethers includes a filament. **Claim 13** The catheter according to claim 11, wherein each of the plurality of tethers includes a planar material sheet. **Claim 14** The catheter according to any one of claims 11 to 13, wherein the plurality of tethers are configured to rotate the emitter shaft about a longitudinal axis of the emitter shaft as the expandable member expands. **Claim 15** The catheter according to any one of claims 1 to 14, wherein the incision member is configured to score a lesion while the ultrasonic transducer delivers a sound pressure wave to the lesion. ​

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