Cutting and scribing lithotripsy balloon catheter

Abstract

The catheter is configured to substantially simultaneously cut or scribe a lesion and deliver pressure waves to the lesion. An illustrative catheter may include a catheter shaft, an expandable member secured to a distal portion of the catheter shaft, a cutting member secured to the expandable member, and an ultrasound transducer disposed within the expandable member. A tether may be attached between the expandable member and the emitter, the tether self-orienting the emitter toward the target tissue due to non-uniform expansion of the expandable member caused by different compliance between the target tissue and surrounding tissue.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Application Serial No. 63 / 388,474, filed on July 12, 2022, the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to angioplasty balloon catheters having a cutting or scoring element mounted to an angioplasty balloon having an internal lithotripsy emitter. More particularly, the present invention relates to angioplasty balloons for modifying the compliance of lesions within or adjacent to a vessel lumen. Background Art

[0004] Many patients suffer from occluded arteries and other blood vessels that restrict blood flow. The occlusion may 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 blood 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 catheter can include a catheter shaft, an expandable member secured to a distal portion of the catheter shaft, a cutting member secured to the expandable member, and an ultrasonic transducer disposed within the expandable member.

[0007] Alternatively or additionally to any of the above examples, in another example, the catheter shaft can include an inner tubular member defining a first lumen and an outer tubular member defining a second lumen.

[0008] Alternatively or additionally to any of the above examples, in another example, the inner tubular member can be twistable.

[0009] Alternatively or additionally to any of the above examples, in another example, the outer tubular member can be twistable.

[0010] Alternatively or additionally to any of the above examples, in another example, the expandable member can include an inflatable balloon.

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

[0012] Alternatively or additionally to any of the above examples, in another example, the ultrasound transducer can be attached to the outer surface of the inner tubular member.

[0013] Alternatively or additionally to any of the above examples, in another example, the catheter may further include a transmitter shaft.

[0014] Alternatively or additionally to any of the above examples, in another example, an ultrasound transducer can be attached to a distal portion of the transmitter shaft.

[0015] Alternatively or additionally to any of the above examples, in another example, the transmitter axis can be rotated relative to the catheter axis.

[0016] Alternatively or additionally to any of the above examples, in another example, the catheter can also include a plurality of tethers extending from the launcher shaft to the expandable member.

[0017] Alternatively or additionally to any of the above examples, in another example, each tether of the plurality of tethers can include a filament.

[0018] Alternatively or additionally to any of the above examples, in another example, each tether of the plurality of tethers can include a planar sheet of material.

[0019] Alternatively or additionally to any of the above examples, in another example, the plurality of tethers can be configured to rotate the launcher shaft about a longitudinal axis of the launcher shaft when the expandable member is expanded.

[0020] Alternatively or additionally to any of the above examples, in another example, the cutting member can be configured to score the lesion when the ultrasound transducer delivers the acoustic pressure waves to the lesion.

[0021] Alternatively or additionally to any of the above examples, in another example, a plurality of tethers can be configured to rotate the transmitter axis to orient the ultrasound transducer toward the lesion.

[0022] Alternatively or additionally to any of the above examples, in another example, multiple tethers may be evenly distributed around the circumference of the transmitter axis.

[0023] Alternatively or additionally to any of the above examples, in another example, the plurality of tethers can include three filaments.

[0024] Alternatively or additionally to any of the above examples, in another example, the ultrasound transducer can be configured to apply a substantially uniform acoustic pressure wave along the length of the lesion.

[0025] Alternatively or additionally to any of the above examples, in another example, the expandable member can include an expandable basket.

[0026] Alternatively or additionally to any of the above examples, in another example, the expandable member can include a plurality of longitudinally extending struts.

[0027] In another example, a balloon catheter may include a catheter shaft, an inflatable balloon secured to a distal portion of the catheter shaft, a cutting member secured to the inflatable balloon, a transmitter shaft, and an ultrasonic transducer disposed on the transmitter shaft and within the inflatable balloon.

[0028] Alternatively or additionally to any of the above examples, in another example, a catheter shaft can include an inner tubular member defining a guidewire lumen and an outer tubular member defining an inflation lumen.

[0029] Alternatively or additionally to any of the above examples, in another example, the transmitter shaft can be disposed within the guidewire lumen.

[0030] Alternatively or additionally to any of the above examples, in another example, a transmitter shaft may be disposed within the inflation lumen.

[0031] Alternatively or additionally to any of the above examples, in another example, the transmitter axis can be rotated relative to the catheter axis.

[0032] Alternatively or additionally to any of the above examples, in another example, the ultrasound transducer can be configured to apply a substantially uniform acoustic pressure wave along the length of the lesion.

[0033] In another example, a catheter may include a catheter shaft, an expandable member secured to a distal portion of the catheter shaft, a plurality of cutting members secured to the expandable member, a transmitter shaft, an ultrasonic transducer disposed on the transmitter shaft and within the expandable member, and a plurality of tethers extending from the transmitter shaft to the expandable member.

[0034] Alternatively or additionally to any of the above examples, in another example, each tether of the plurality of tethers can include a filament.

[0035] Alternatively or additionally to any of the above examples, in another example, each tether of the plurality of tethers can include a planar sheet of material.

[0036] Alternatively or additionally to any of the above examples, in another example, the plurality of tethers can be configured to rotate the launcher shaft about a longitudinal axis of the launcher shaft when the expandable member is expanded.

[0037] Alternatively or additionally to any of the above examples, in another example, a plurality of tethers can be configured to rotate the transmitter axis to orient the ultrasound transducer toward the lesion.

[0038] Alternatively or additionally to any of the above examples, in another example, multiple tethers may be evenly distributed around the circumference of the transmitter axis.

[0039] Alternatively or additionally to any of the above examples, in another example, the plurality of tethers can include three filaments.

[0040] Alternatively or additionally to any of the above examples, in another example, each tether of the plurality of tethers can be circumferentially offset from the plurality of cutting members.

[0041] Alternatively or additionally to any of the above examples, in another example, at least one cutting member of the plurality of cutting members can be configured to score a lesion when the ultrasound transducer delivers acoustic pressure waves to the lesion.

[0042] 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

[0043] 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:

[0044] Figure 1A is a cross-sectional view of an illustrative balloon catheter having a cutting or scoring element anchored to a vessel wall and a lithotripsy transmitter disposed in the vessel;

[0045] Figure 1B It is possible to Figure 1A A stereoscopic view of an illustrative scored cage for use with a balloon catheter;

[0046] Figure 2 It is placed in a vessel with an eccentric calcified lesion Figure 1A A transverse cross-sectional view of an illustrative balloon catheter;

[0047] Figure 3is a cross-sectional side view of another illustrative balloon catheter disposed in a blood vessel at a circumferential orientation of 90 degrees relative to FIG. 1 ;

[0048] Figure 4 The device is placed in a blood vessel having an eccentric calcified lesion and is inflated in a first configuration. Figure 3 a transverse cross-sectional view of an illustrative balloon catheter constrained to balloon inflation on a side having calcium and dilated to a more compliant side of a vessel not having calcium, with a lithotripsy transmitter directed away from the pathological calcium;

[0049] Figure 5 It is set in the blood vessel in the second form Figure 3 Transverse cross-sectional view of an illustrative balloon catheter with the lithotripsy transmitter oriented at the lesion calcium;

[0050] Figure 6 is a transverse cross-sectional view of another illustrative uninflated balloon catheter having a self-orienting band between a lithotripsy transmitter and a balloon or element disposed in a first configuration in a blood vessel having a lithotripsy transmitter oriented away from pathological calcium;

[0051] Figure 7 It is inflated Figure 6 a transverse cross-sectional view of a balloon catheter having an element that anchors to a vessel wall and a self-aligning band that rotates the orientation of the transmitter toward a non-compliant lesion and is disposed in the vessel; and

[0052] Figure 8 is a side view of an expandable frame having self-orienting bands and cutting or scoring elements anchored to a vessel wall and a lithotripsy emitter disposed in the vessel.

[0053] 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

[0054] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.

[0055] All numerical values ​​are assumed herein to be modified by the term "about", whether or not expressly indicated. The term "about" generally refers to a range of numbers that one skilled in the art considers equivalent to the referenced value (i.e., having the same function or result). In many cases, the term "about" may mean including numbers rounded to the nearest significant figure.

[0056] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0057] 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.

[0058] 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 its sense including "and / or" unless the content clearly dictates otherwise.

[0059] 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 shown are intended to be exemplary only. The selected features of any illustrative embodiment may be incorporated into another embodiment unless expressly indicated to the contrary.

[0060] 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 using various devices to create or expand 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 lesion in order to modify its compliance so that full expansion can be achieved prior to stent placement.

[0061] 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. However, the efficacy of ultrasound treatment of eccentric calcified lesions may be reduced compared to lesions extending around the entire circumference of the blood vessel. For example, ultrasound or shock waves can be emitted from ultrasound transducers that are about 180° relative to each other. If the emitted shock waves are not aligned with the lesion, the shock waves may not destroy or modify the lesion. The user may have little or no control over the circumferential orientation of the transmitter. It may be desirable to provide a device or system that self-orients the transmitter toward a calcified lesion. Although the device or system described herein is described with respect to vascular lesions, it should be understood that the device or system may also be used in other applications, such as, but not limited to, peripheral calcified lesions, the aortic valve, the mitral valve, or non-vascular applications including tumor treatment. For example, the methods and systems described herein may be used in any catheter that requires aiming or directing a transmitter. The catheter may have differences in compliance due to lesions, tumors, etc. It is conceivable that the devices and systems described herein can orient the transmitter toward a peripheral lesion or tumor and away from the corresponding organ.

[0062] Figure 1A 1 is a partial cross-sectional view of an illustrative catheter 10 that can be used to treat a lesion disposed in a blood vessel 12 and positioned near an intravascular lesion 14. The catheter 10 can be configured to cut or score the lesion 14 and to emit shock waves or an ultrasonic field. It is contemplated that the combination of ultrasonic energy and cutting or scoring elements can cover a wider circumferential area than using only one of them. This can improve the efficacy of treatment, particularly in lesions with low circumferential calcification angles (e.g., lesions extending less than the entire circumference of the blood vessel 12).

[0063] The catheter 10 may include a balloon 16 coupled to a catheter shaft 18. One or more cutting members or blades 20 may be mounted on or above the balloon 16. The cutting member 20 may be a cutting blade, such as Figure 1A As shown, or the carved components, such as Figure 1BTypically, catheter 10 can be advanced over guidewire 22, through the vascular system, to a target area with balloon 16 in a collapsed or deflated configuration. Once positioned at a target location in the vascular system, balloon 16 can be inflated to apply a radially outward force to the lesion, and cutting member 20 can engage lesion 14. Thus, cutting member 20 can cut or score lesion 14 so that the sheath is proximate to the lumen of lesion 14. The target area can be located in any suitable peripheral or cardiac vascular lumen location.

[0064] The cutting members 20 may vary in number, location, and arrangement about the balloon 16. For example, the catheter 10 may include one, two, three, four, five, six, or more cutting or scoring members 20 disposed at any location along the balloon 16 and in a regular, irregular, or any other suitable pattern. For example, in some embodiments, the balloon 16 may include a plurality of cutting members 20 extending longitudinally along the length of the balloon 16 and symmetrically arranged about the circumference of the balloon 16. This is merely an example.

[0065] The cutting member 20 can be made of any suitable material, such as a metal, a metal alloy, a polymer, a metal-polymer composite, etc., or any other suitable material. For example, the cutting member 20 can be made of stainless steel, titanium, nickel-titanium alloy, tantalum, iron-cobalt-nickel alloy, or in some cases other metallic materials.

[0066] The balloon 16 can be made of common 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, etc. thereof.

[0067] Balloon 16 can be configured such that when balloon 16 is deflated, balloon 16 includes one or more "wings" or wing-shaped regions. In some cases, the wings can be configured such that cutting member 20 can be positioned at the most inward position of the deflated balloon 16, with cutting member 20 folded under the wings of balloon 16. This arrangement can reduce exposure of cutting member 20 to the blood vessel during delivery of balloon 16 to lesion 14. Other configurations can be used as desired.

[0068] The shaft 18 can be a catheter shaft, similar to a conventional 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.

[0069] 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 can be twistable and rotated independently of the outer tubular member 26 to rotate the lithotripsy transmitter or ultrasonic transducer 38. For example, the inner tubular member 24 can include an embedded reinforcing member 50. For example, the inner tubular member 24 can include an embedded coil or braided member. Alternatively or additionally, outer tubular member 26 may be twistable (eg, including an embedded braid or coil reinforcement member) to facilitate rotation of the entire device 10 within the vasculature prior to or between inflations.

[0070] 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.

[0071] 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.

[0072] 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 end 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 end of the inner tubular member 24. However, the exact bonding locations may vary.

[0073] The inner tubular member 24 may include an ultrasonic transducer or transmitter 38. The ultrasonic transducer 38 may be coupled to the outer surface of the inner tubular member 24, adjacent to its distal portion, so 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 in 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 may be operated to effectively act as a single ultrasonic transducer, thereby providing the desired acoustic pressure above the desired treatment area. The applied acoustic pressure range may be tens of kilopascals (kPa) to more than ten megapascals (MPa).

[0074] The ultrasonic transducer 38 can generate an ultrasonic field 40 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 in directions about 180° apart.

[0075] 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 blood 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 blood 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. Although not explicitly shown, multiple ultrasonic transducers 38 can be used and configured to extend the effective treatment length, such as, to a length of up to about 200 mm.

[0076] 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. 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 to effectively act 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 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 14.

[0077] 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.

[0078] Figure 1B is a perspective view of an illustrative scoring cage 60 that may be used in place of Figure 1A1 and 12. The scoring cage 60 may extend from a first or proximal end 62 to a second or distal end 64. The proximal end 62 may include a proximal collar or proximal tubular member 66. The proximal collar 66 may be configured to be disposed above the outer tubular member 26, adjacent to or proximal to the proximal waist 34 of the balloon 16. In some cases, the proximal collar 66 may be fixed to the outer surface of the outer tubular member 26. In other embodiments, the proximal collar 66 may be slidably disposed above the outer tubular member 26. The distal end 64 may include a distal collar or distal tubular member 68. The distal collar 68 may be configured to be disposed above the inner tubular member 24, adjacent to or distal to the distal waist 36 of the balloon 16. In some cases, the distal collar 68 may be fixed to the outer surface of the inner tubular member 24. The scoring cage 60 may also include one or more longitudinally extending wires 70a, 70b, 70c, 70d (collectively referred to as 70) extending between the proximal loop 66 and the distal loop 68. The longitudinally extending wires 70 may be positioned along the outer surface of the balloon 16. When the balloon 16 is expanded, the wires 70 may be pushed into the lesion 14 to score the lesion 14. Although the scoring cage 60 is shown as including four wires 70, the scoring cage 60 may include less than four or more than four wires 70 as desired. In addition, the wires 70 may be spaced evenly or eccentrically around the circumference of the balloon 16 as desired.

[0079] Additional references Figure 2 , which shows a transverse cross-sectional view of the balloon 16, when the balloon 16 is expanded at the target area (e.g., adjacent to the lesion 14), the cutting member 20 will deliver the amplified force generated by the balloon pressure to create a controlled longitudinal crack in the lesion 14. In some cases, the anchored cutting member 20 can supplement the force at the balloon contact point 42, which may be needed to propagate the crack at a lower pressure while reducing vascular trauma. In addition to the cutting member 20 penetrating the lesion 14, the ultrasonic transducer 38 can be activated to generate an ultrasonic field 40. It is contemplated that the ultrasonic transducer 38 can be positioned so that the ultrasonic field 40 is aligned with the cutting member 20 and the force amplification area of ​​the balloon 16 (e.g., the cutting member 20 and / or the balloon contact point 42) to combine and focus the two energy modes on the same point. For example, during assembly, the ultrasonic transducer 38 can be positioned on the inner tubular member 24 so that the generated ultrasonic field 40 is aligned with at least one cutting member 20. When the lesion 14 is asymmetric or extends around less than the entire circumference of the vessel 12, the portion of the vessel 12 without the lesion 14 may be more compliant or may stretch more in response to the expansion of the balloon. It is contemplated that the anchoring effect of the cutting member 20 may also stabilize the compliant side of the vessel 12, which in turn may increase the effectiveness of the ultrasound field 40.

[0080] Figure 31 is a partial cross-sectional view of another illustrative catheter 100 that can be used to treat a lesion disposed in a blood vessel 102 and positioned near an intravascular lesion 104. The catheter 100 can be configured to cut or score the 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 efficacy of treatment, particularly in lesions with low circumferential calcification angles (e.g., lesions extending less than the entire circumference of the blood vessel 102).

[0081] The catheter 100 can include a balloon 106 coupled to a catheter shaft 108. One or more cutting members or blades 110 can be mounted on the balloon 106. The cutting member 110 can be a cutting blade or a scoring member. Typically, the catheter 100 can be advanced over a guidewire 112, through a vascular system, to a target area with the balloon 106 in a collapsed or deflated configuration. Once positioned at a target location in the vascular system, the balloon 106 can be inflated to apply a radially outward force to the lesion, and the cutting member 110 can engage the lesion 104. Thus, the cutting member 110 can cut or score the lesion 104 so that the sheath is proximate to the cavity of the lesion 104. The target area can be located in any suitable peripheral or cardiac vascular cavity location.

[0082] The cutting members 110 may vary in number, location, and arrangement about the balloon 106. For example, the catheter 100 may include one, two, three, four, five, six, or more cutting members 110 disposed at any location along the balloon 106 and in a regular, irregular, or any other suitable pattern. For example, in some embodiments, the balloon 106 may include a plurality of cutting members 110 extending longitudinally along the length of the balloon 106 and symmetrically arranged about the circumference of the balloon 106. This is merely an example.

[0083] The cutting member 110 can be made of any suitable material, such as a metal, a metal alloy, a polymer, a metal-polymer composite, etc., or any other suitable material. For example, the cutting member 110 can be made of stainless steel, titanium, nickel-titanium alloy, tantalum, iron-cobalt-nickel alloy, or in some cases other metallic materials.

[0084] The balloon 106 can be made of common 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, etc. thereof.

[0085] The balloon 106 can be configured such that when the balloon 106 is deflated, the balloon 106 includes one or more "wings" or wing-shaped regions. In some cases, the wings can be configured such that the cutting member 110 can be positioned at the most inward position of the deflated balloon 106, with the cutting member 110 folded under the wings of the balloon 106. This arrangement can reduce exposure of the cutting member 110 to the blood vessel during delivery of the balloon 106 to the lesion 104. Other configurations can be used as desired.

[0086] The shaft 108 can be a catheter shaft, similar to a conventional catheter shaft. For example, the catheter shaft 108 can include an outer tubular member 116 and an inner tubular member 114 extending through at least a portion of the outer tubular member 116. The inner tubular member 114 and the outer tubular member 116 can be made of a variety of different materials. For example, the inner tubular member 114 and the outer tubular member 116 can be made of metal, metal alloys, polymers, metal-polymer composites, or any other suitable material.

[0087] The inner tubular member 114 and the outer tubular member 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 tubular member 114 and the outer tubular member 116 may or may not be fixed to each other along the general 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 tubular member 114 and the outer tubular member 116 can be arranged in another desired manner.

[0088] The inner tubular member 114 may include an inner cavity 120. In at least some embodiments, the inner cavity 120 is a guidewire cavity for receiving a guidewire (not explicitly shown) therethrough. Therefore, the catheter 100 can be advanced to a desired position over the guidewire. The guidewire cavity 120 can extend substantially along the entire length of the catheter shaft 108, so that the catheter 100 is similar to a traditional "over-the-wire" catheter. Alternatively, the guidewire cavity 120 can extend only along a portion of the catheter shaft 108, so that the catheter 100 is similar to a "single operator exchange" or "rapid exchange" catheter.

[0089] The catheter shaft 108 can also include an inflation lumen 122, which can be used, for example, to deliver 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 tubular member 114 and the outer tubular member 116. For example, when the outer tubular member 116 surrounds the inner tubular member 114, the inflation lumen 122 can be defined in the space between the outer tubular member 116 and the inner tubular member 114. In embodiments where the outer tubular member 116 is disposed alongside the inner tubular member 114, the inflation lumen 122 can be a lumen of the outer tubular member 116.

[0090] The balloon 106 can be coupled to the catheter shaft 108 in any of a variety of suitable ways. For example, the balloon 106 can be glued or heat bonded to the catheter shaft 108. In some embodiments, the proximal waist 124 of the balloon 106 can be bonded to the catheter shaft 108, such as to the distal end of the outer tubular member 116, and the distal waist 126 of the balloon 106 can be bonded to the catheter shaft 108, such as to the distal end of the inner tubular member 114. However, the exact bonding locations may vary.

[0091] The transmitter shaft 118 can be disposed within the guidewire lumen 120. Although the transmitter shaft 118 is shown as being within the guidewire lumen 120, the transmitter shaft 118 can alternatively be disposed within the inflation lumen 122. The transmitter shaft 118 can be made of a variety of different materials. For example, the transmitter shaft 118 can be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material. In some cases, the transmitter shaft 118 can be longitudinally translated and / or rotated within the respective cavities 120, 122. In some embodiments, the transmitter shaft 118 can include a reinforcing member 119, such as, but not limited to, a coil or braid, or be formed thereof to achieve torquability.

[0092] The transmitter shaft 118 may include an ultrasonic transducer or transmitter 128 positioned near its distal region 132. During surgery, the transmitter shaft 118 may be positioned so that the ultrasonic transducer 128 is located within the balloon 106 to be approximately aligned with the cutting member 110. The ultrasonic transducer 128 may be coupled to the outer surface of the transmitter shaft 118. In some cases, the ultrasonic transducer 128 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 128 may be driven at one or more frequencies in 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 may be operated to effectively act 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).

[0093] The ultrasonic transducer 128 can generate an ultrasonic field 130 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 128, 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 128, wherein the acoustic pressure wave emitted by the ultrasonic transducer 128 is not focused and can be controlled to be substantially uniform on the calcified lesion 104. The ultrasonic transducer 128 can be configured to emit ultrasonic waves in two opposite directions or in directions about 180° apart.

[0094] In some cases, for example, the ultrasonic transducer 128 can be configured to apply a uniform or substantially uniform acoustic pressure wave along the length of the calcified lesion 104. In cardiovascular disease states, the vascular lesion can span a length of about 10 millimeters (mm) to about 25 mm in a blood 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 blood vessel having a diameter of up to about 12 mm. Depending on the therapeutic application, the ultrasonic transducer 128 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 108. Although not explicitly shown, multiple ultrasonic transducers 128 can be used and configured to extend the effective treatment length, such as, to a length of up to 200 mm.

[0095] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 128 can be more than the diameter of the transmitter shaft 118 and / or the outer tubular member 116. In some cases, the length of the ultrasonic transducer 128 can be at least as long as the length of the calcified lesion 104, in some cases, 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 128 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements, which are driven in a way to effectively act as a single ultrasonic transducer. Although not explicitly shown, the ultrasonic transducer 128 can be electrically connected to an electronic source via one or more wires. In some cases, two or more ultrasonic transducers can be connected to a single electronic source and driven at the same frequency and output. 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.

[0096] The balloon 106 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 106, one can control the efficiency of acoustic energy transmission through the fluid and to the calcified lesion 104. 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 128 and the vessel wall 102. 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 106. 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 128.

[0097] Additional references Figure 4, which shows a transverse cross-sectional view of a balloon 106, when the balloon 106 is expanded at a target area (e.g., adjacent to a lesion 104), the cutting member 110 delivers the amplified force generated by the balloon pressure to the lesion 104 to create a controlled longitudinal crack in the lesion. In some cases, the anchored cutting member 110 can supplement the force at the balloon contact point 134, which may be needed to propagate the crack at a lower pressure while reducing vascular trauma. In addition to the cutting member 110 penetrating the lesion 104, the ultrasonic transducer 128 can be activated to generate an ultrasonic field 130. It is contemplated that the ultrasonic transducer 128 can be positioned so that the ultrasonic field 130 is aligned with the cutting member 110 and the force amplification region of the balloon 106 (e.g., the cutting member 110 and / or the balloon contact point) to combine and focus the two energy modes on the same point. For example, during assembly, the ultrasonic transducer 128 can be positioned to align with at least one cutting member 110. When the lesion 104 is asymmetric or extends around less than the entire circumference of the vessel 102, the portion of the vessel 102 without the lesion 104 may be more compliant or may stretch more in response to the expansion of the balloon. It is contemplated that the anchoring effect of the cutting member 110 may also stabilize the compliant side of the vessel 102, which in turn may increase the effectiveness of the ultrasound field 130.

[0098] Once the balloon 106 is inflated to anchor into the blood vessel 102, the ultrasound transducer 128 can deliver the required energy. In some cases, the original orientation of the ultrasound transducer 128 and therefore the ultrasound field 130 may not be well aligned with the lesion 104 to be destroyed, such as Figure 4 Once energy has been delivered, the transmitter shaft 118 can be rotated and energy can again be delivered to a different section of the circumference of the blood vessel 102, such as Figure 5 As shown. It is contemplated that the transmitter shaft 118 can be gradually rotated until an optimal direction for dehiscence of the lesion 104 is achieved. In some cases, the transmitter shaft 118 can be rotated in increments of 90° or less. The proximal region of the transmitter shaft 118 can include markings or other visual indicia to indicate how much the transmitter shaft 118 has been rotated relative to the initial orientation.

[0099] In some embodiments, differences in vessel compliance due to eccentric lesions 104 may cause balloon 106 to expand unevenly. For example, balloon 106 may have an inflated size and shape that varies with inflation pressure and the compliance of vessel 102. In one example, balloon 106 may expand more on the opposite side of a non-compliant calcified lesion 104, such as Figure 4 and Figure 5 It is contemplated that uneven expansion of the balloon 106 may be utilized to orient the ultrasound transducer 128 toward the lesion 104 . Figure 61 is another transverse cross-sectional view of the balloon 106 in a collapsed or deflated state and including additional features that automatically orient the ultrasonic transducer 128 toward a non-compliant lesion disposed within the vessel 102 having an eccentric lesion 104. The balloon 106 may also include a plurality of tethers 140a, 140b, 140c (collectively 140) extending from a first end 142a, 142b, 142c (collectively 142) coupled or secured to the transmitter shaft 118 and a second end 144a, 144b, 144c (collectively 144) coupled or secured to the balloon 106 or the cutting member 110. Figure 7 is in an inflated state Figure 6 The uneven expansion of the balloon 106 toward the compliant side of the vessel exerts greater tension on the tether 140 on that side than on the non-compliant side (e.g., toward the lesion 104), thereby automatically rotating or orienting the ultrasound transducer 128 toward the non-compliant calcified lesion 104.

[0100] In some embodiments, each tether 140 can be a string, a filament, or a plurality of strings or filaments woven or twisted together. In other embodiments, the tether 140 can be a planar sheet of material having a length extending generally parallel to the longitudinal axis of the transmitter shaft 118 and a width extending between the outer surface of the transmitter shaft 118 and the inner surface of the balloon 106. In other embodiments, the tether 140 can be a magnet or formed of a magnetic material. The tether 140 can be formed of a stretch-resistant material. The tethers 140 can be spaced evenly or eccentrically around the circumference of the transmitter shaft 118. In some cases, the tethers 140 can be positioned circumferentially between the cutting members 110, however this is not required. It is also contemplated that the tethers 140 can be positioned at similar longitudinal positions or different longitudinal positions of the transmitter shaft 118 as desired. Although three tethers 140 are shown, it is contemplated that there can be less than three or more than three tethers as desired.

[0101] Reference now Figure 7 , when the balloon 106 is inflated, the balloon 106 may expand more on the side of the blood vessel 102 that does not have the lesion 104. When the balloon 106 is inflated, the second ends 144a, 144b of the first and second tethers 140a, 140b are pulled farther away from the transmitter shaft 118 because the blood vessel 102 is more compliant on the opposite side of the lesion 104 and the balloon 106 expands to a greater extent. When the second ends 144a, 144b are pulled radially apart, the first and second tethers 140a, 140b cause the transmitter shaft 118 to rotate. For example, in Figure 6In the deflated configuration shown, the ultrasound transducer 128 is oriented to transmit ultrasound energy 130 in a first orientation away from the calcified lesion 104, as indicated by arrow 150. When the balloon 106 is inflated, the tethers 140a, 140b on the non-calcified side of the balloon 106 are placed under greater strain than the tether 140c on the calcified side of the balloon 106. The increased strain on the first and second tethers 140a, 140b causes the transmitter shaft 118 to rotate so that the ultrasound transducer 128 is oriented to transmit ultrasound energy 130 in a second direction toward the calcified lesion 104, as indicated by arrow 150. Figure 7 152. The second orientation can direct the ultrasonic energy 130 toward the lesion 104. In other words, the tether 140 can cause the ultrasonic transducer 128 to self-align with the non-compliant target lesion 104 when the balloon 106 is inflated. It is further contemplated that the tether 140 can stabilize the ultrasonic transducer 128 within the balloon 106 to achieve additional therapeutic efficacy. In some cases, the cutting member 110 opposite the lesion 104 can reflect the ultrasonic energy back toward the lesion 104, thereby further improving the therapeutic efficacy. The cutting member 110 can act as an anchor to stabilize the balloon 106 to promote the tether force on the ultrasonic transducer 128 to achieve rotation.

[0102] In some embodiments, an expandable metal or polymer frame may be used instead of an inflatable balloon to anchor, apply force on the lesion, and expand in response to compliance differences in the vessel rather than uniformly to self-align the transmitter toward the target tissue. Figure 8 A side view of another illustrative catheter 200 is shown, which can be used to treat lesions disposed in a blood vessel 202 and positioned near an intravascular lesion 204. The catheter 200 can be configured to cut or score the lesion 204 and emit shock waves or an ultrasonic field. It is contemplated that the combination of ultrasonic energy and the cutting or scoring elements can cover a wider circumferential area than either alone. This can improve the efficacy of treatment, particularly in lesions with low circumferential calcification angles (e.g., lesions extending less than the entire circumference of the blood vessel 202).

[0103] The catheter 200 may include an expandable basket 206 coupled to a catheter shaft 208. The shaft 208 may be an outer tubular member or catheter shaft, similar to a conventional catheter shaft. For example, the catheter shaft 208 may be a tubular member extending from a distal region 212 to a proximal region (not explicitly shown) that is configured to remain outside the patient's body. The lumen 214 may extend from the distal region 212 to the proximal region.

[0104] The catheter 200 may also include an inner tubular member 216 that may be slidably disposed within the lumen 214 of the catheter shaft 208. At least a portion of the expandable basket 206 may be coupled to a distal region 230 of the elongated shaft 216. The catheter shaft 208 and the inner tubular member 216 may be made of a variety of different materials. For example, the catheter shaft 208 and the inner tubular member 216 may be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material. A transmitter shaft 232 may be disposed within the lumen 234 of the inner tubular member 216. Although the transmitter shaft 232 is shown as being located within the lumen 234 of the inner tubular member, the transmitter shaft 232 may alternatively be disposed within the lumen 214 of the elongated shaft 208. The transmitter shaft 232 may be made of a variety of different materials. For example, the transmitter shaft 232 may be made of a metal, a metal alloy, a polymer, a metal-polymer composite, or any other suitable material. In some cases, the transmitter shaft 232 can translate longitudinally and / or rotate within the respective lumens 214, 234. In some embodiments, the transmitter shaft 232 can include or be formed from a reinforcing member, such as, but not limited to, a coil or braid, to enable twistability.

[0105] The expandable basket 206 can be configured to transition between a collapsed configuration and an expanded configuration ( Figure 8 ). The expandable basket 206 can include a plurality 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 cap 236. In some cases, the cap 236 can include spacers that are used to maintain consistent spacing between each of the struts 218. However, this is not required. In some cases, the struts 218 can be arranged eccentrically. The struts 218 can be configured to extend generally along the longitudinal axis of the catheter shaft 208. Although the expandable basket 206 is shown as including two longitudinally extending struts 218, 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 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.

[0106] The expandable basket 206 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 206 may be heat set in an expanded state and subsequently compressed to fit within, for example, the catheter shaft 208 and / or the inner tubular member 216. 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 206. It is contemplated that Nitinol 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 206.

[0107] In other cases, manual force applied to the inner tubular member 216 can manipulate or actuate the expandable basket 206 between the expanded and collapsed states. For example, the actuation element can include a centerline extending through the expandable basket 206. According to this embodiment, a pulling force applied proximally on the line can allow the struts 218 to expand and move the expandable basket 206 into the expanded state. A pushing force applied distally on the line can move and elongate the struts 218 and / or otherwise cause the ablation device to transition to a compressed or extended state. Other actuation mechanisms can also be utilized.

[0108] As discussed above, the expandable basket 206 can include a plurality of expandable positioning elements, such as longitudinally extending struts 218. The catheter 100 can each extend from a proximal region 220 to a distal region 222. An intermediate region 224a, 224b (collectively 224) can be disposed between the proximal region 220 and the distal region 222. It is contemplated that in the expanded state, the intermediate region 224 of the struts 218 can contact the vessel wall 202.

[0109] One or more cutting members or blades 210 can be mounted on or above the expandable basket 206. For example, one or more cutting members 210 can be coupled to the middle region 224 of the support 218. The cutting member 210 can be a cutting blade, such as Figure 8 As shown, or the depicted member (see, for example, Figure 1B). In general, catheter 200 can be advanced through the vascular system to a target area with expandable basket 206 in a collapsed configuration. Once positioned at a target location in the vascular system, expandable basket 206 can be expanded to apply a radially outward force to lesion 204, and one or more of cutting members 210 can engage lesion 204. Thus, cutting members 210 can cut or score lesion 204 so that the sheath is proximate to the lumen of lesion 204. The target area can be located in any suitable peripheral or cardiac vascular lumen location.

[0110] The transmitter shaft 232 may include an ultrasonic transducer or transmitter 226. The ultrasonic transducer 226 may be coupled to the outer surface of the transmitter shaft 232 adjacent to its distal portion. During surgery, the transmitter shaft 232 may be positioned so that the ultrasonic transducer 226 is located within the basket 206 to be generally aligned with the cutting member 210. For example, the transmitter shaft 232 may move axially and rotationally relative to the inner tubular member 216. In some cases, the ultrasonic transducer 226 may include a piezoelectric material that transmits acoustic pressure in response to an applied voltage. The ultrasonic transducer 226 may be driven at one or more frequencies in 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 may be operated to effectively function as a single ultrasonic transducer to provide the desired acoustic pressure over the desired treatment area. The applied sound pressure may range from tens of kilopascals (kPa) to over ten megapascals (MPa).

[0111] The ultrasonic transducer 226 can generate an ultrasonic field 228 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 226, 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 226, wherein the acoustic pressure wave emitted by the ultrasonic transducer 226 is not focused and can be controlled to be substantially uniform on the calcified lesion 204. The ultrasonic transducer 226 can be configured to emit ultrasonic waves in two opposite directions or in directions about 180° apart.

[0112] In some cases, for example, the ultrasonic transducer 226 can be configured to apply a uniform or substantially uniform acoustic pressure along the length of the calcified lesion 204. 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 226 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 208. Although not explicitly shown, multiple ultrasonic transducers 226 can be used and configured to extend the effective treatment length, such as, to a length of up to about 200 mm.

[0113] In order to apply a uniform or substantially uniform acoustic pressure in the near field, the length of the ultrasonic transducer 226 can be more than the diameter of the transmitter shaft 232, the inner tubular member 216, and / or the outer tubular member 208. In some cases, the length of the ultrasonic transducer 226 can be at least as long as the length of the calcified lesion 204 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 226 can be a single ultrasonic transducer or a series of ultrasonic transducers or transducer elements that are driven in a manner to effectively act 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 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 204.

[0114] When the expandable basket 206 is expanded at a target area (e.g., adjacent to the lesion 204), the cutting member 210 delivers the amplified force generated by the balloon pressure to the lesion 204 to create a controlled longitudinal crack in the lesion 204. In some cases, the anchored cutting member 210 can supplement the force at the basket 206 contact point, which may be needed to propagate the crack at a lower pressure while reducing vascular trauma. In addition to the cutting member 210 penetrating the lesion 204, the ultrasonic transducer 226 can be activated to generate an ultrasonic field 228. It is contemplated that the ultrasonic transducer 226 can be positioned so that the ultrasonic field 228 is aligned with the cutting member 210 and the force amplification area of ​​the expandable basket 206 (e.g., the cutting member 210 and / or the basket contact point) to combine and focus the two energy modes on the same point. For example, during insertion, the ultrasonic transducer 226 can be positioned to align the generated magnetic field 228 with at least one cutting member 210. When the lesion 204 is asymmetric or extends around less than the entire circumference of the vessel 202, the portion of the vessel 202 without the lesion 204 may be more compliant or may stretch more in response to the expansion of the basket. It is contemplated that the anchoring effect of the cutting member 210 may also stabilize the compliant side of the vessel 202, which in turn may increase the effectiveness of the ultrasound field 228.

[0115] In some embodiments, the expandable basket 206 may further include a plurality of tethers 236a, 236b, 236c, 236d (collectively 236) extending from a first end 238a, 238b, 238c, 238d (collectively 238) coupled or secured to the transmitter shaft 232 and a second end 240a, 240b, 240c, 240d (collectively 240) coupled or secured to the expandable basket 206 or the cutting member 210. Typically, the uneven expansion of the expandable basket 206 toward the compliant side of the vessel exerts greater tension on the tethers 236 on that side than on the non-compliant side (e.g., toward the lesion 204), thereby automatically rotating or orienting the ultrasound transducer 226 toward the non-compliant calcified lesion 204.

[0116] In some embodiments, each tether 236 can be a string, a filament, or a plurality of strings or filaments woven or twisted 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 launcher shaft 232 and a width extending between the outer surface of the launcher shaft 232 and the inner surface of the expandable basket 206. In other embodiments, the tether 236 can be a magnet or formed of a magnetic material. The tether 236 can be formed of a material that resists stretching. The tethers 236 can be spaced evenly or eccentrically around the circumference of the launcher shaft 232. It is also contemplated that the tethers 236 can be positioned at similar longitudinal locations or different longitudinal locations of the launcher shaft 232 as desired. Although four tethers 236 are shown, it is contemplated that there can be fewer than four or more than four tethers as desired.

[0117] As the expandable basket 206 expands, the expandable basket 206 may expand more on the side of the blood vessel 202 that does not have the lesion 204. As the expandable basket 206 expands, the second ends 240a, 240b of the first and second tethers 236a, 236b are pulled farther away from the transmitter shaft 232 because the blood vessel 202 is more compliant on the opposite side of the lesion 204 and the expandable basket 206 expands to a greater extent. As the second ends 240a, 240b are pulled radially apart, the first and second tethers 236a, 236b cause the transmitter shaft 232 to rotate. In other words, using the expandable basket 206 as 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 on the first and second tethers 236a, 236b causes the transmitter shaft 232 to rotate so that the ultrasonic transducer 226 is oriented to transmit ultrasonic energy 228 in an orientation toward the calcified lesion 104. This can direct the ultrasonic energy 228 toward the lesion 204. For example, the tether 236 can cause the ultrasonic transducer 226 to self-align with the non-compliant target lesion 204 when the expandable basket 206 is expanded. It is further contemplated that the tether 236 can stabilize the ultrasonic transducer 226 within the expandable basket 206 to achieve additional therapeutic efficacy. In some cases, the cutting member 210 opposite the lesion 204 can reflect ultrasonic energy back toward the lesion 204, thereby further improving the therapeutic efficacy. The cutting member 210 can act as an anchor to stabilize the expandable basket 206 to promote the tether force on the ultrasonic transducer 226 to achieve rotation.

[0118] Materials that can be used for 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, members, components or devices disclosed herein, such as, but not limited to, catheter shafts, inflatable balloons, cutting members, transmitter shafts, etc. and / or elements or components thereof.

[0119] 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.

[0120] 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) 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 / ether, polyether block amide (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.

[0121] 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 ALLOY ), 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.

[0122] In at least some embodiments, part or all of the system and / or portions thereof may also be doped with, made of, or otherwise include radiopaque materials. Radiopaque materials are understood to be capable of producing relatively bright images on a fluoroscopic screen or with another imaging technique during a medical procedure. Such relatively bright images assist the user of the system in determining 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.

[0123] 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 be unsuitable 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.

[0124] In some embodiments, the system and / or other elements disclosed herein may include and / or be treated with a suitable therapeutic agent. 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 ketone); 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.

[0125] It should be understood that the present invention is in many respects merely illustrative. Changes may be made in details, particularly matters of shape, size, and arrangement of steps, without exceeding the scope of the present 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 present invention is defined by the language of the appended claims.

Claims

1. A catheter, comprising: catheter shaft; an expandable member secured to a distal portion of the catheter shaft; a cutting member secured to the expandable member; as well as An ultrasonic transducer is disposed within the expandable member. 2 . The catheter of claim 1 , wherein the catheter shaft comprises an inner tubular member defining a first lumen and an outer tubular member defining a second lumen.

3. The catheter of claim 2, wherein the inner tubular member is twistable.

4. The catheter of any one of claims 2 to 3, wherein the outer tubular member is twistable.

5. The catheter of any one of claims 1 to 4, wherein the expandable member comprises an inflatable balloon.

6. The catheter of any one of claims 1 to 4, wherein the expandable member comprises an expandable cage.

7. The catheter of any one of claims 2 to 6, wherein the ultrasound transducer is attached to an outer surface of the inner tubular member.

8. The catheter of any one of claims 1 to 6, further comprising a transmitter shaft.

9. The catheter of claim 8, wherein the ultrasonic transducer is attached to a distal portion of the transmitter shaft.

10. The catheter of any one of claims 8 to 9, wherein the transmitter axis is rotatable relative to the catheter axis.

11. The catheter of any one of claims 8 to 10, further comprising a plurality of tethers extending from the launcher shaft to the expandable member.

12. The catheter of claim 11, wherein each of the plurality of tethers comprises a filament.

13. The catheter of claim 11, wherein each tether of the plurality of tethers comprises a planar sheet of material.

14. The catheter of any one of claims 11 to 13, wherein the plurality of tethers are configured to rotate the launcher shaft about a longitudinal axis of the launcher shaft when the expandable member is expanded.

15. The catheter of any one of claims 1 to 14, wherein the cutting member is configured to score the lesion when the ultrasonic transducer delivers acoustic pressure waves to the lesion.

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