Intravascular lithotripsy catheter with a movable emitter - Patent Application 20070122997

Abstract

A catheter for treating an obstruction in a body cavity includes a movable emitter carrier having one or more shock wave emitters. The one or more shock wave emitters are movable longitudinally along the inner shaft of the catheter. In a first configuration of the catheter, the one or more shock wave emitters are retracted from a distal fluid-fillable enclosure. In a second configuration of the catheter, the one or more shock wave emitters are inserted into the distal fluid-fillable enclosure.

Description

[Technical Field]

[0001] Priority This application claims priority to U.S. Provisional Patent Application No. 63 / 442,980, filed February 2, 2023, and U.S. Nonprovisional Patent Application No. 18 / 428,752, filed January 31, 2024, which are incorporated by reference in their entireties. This application is related to U.S. Patent Application No. 18 / 428,976, filed January 31, 2024, entitled "INTRAVASCULAR LITHOTRIPSY CATHETER WITH MOVABLE EMITTERS," the disclosure of which is incorporated by reference in its entirety.

[0002] Field of Disclosure The present disclosure relates generally to the field of medical devices and methods, and more particularly to a shockwave catheter device for treating calcified lesions in body cavities, such as calcified lesions and occlusions in the vascular system, and kidney stones in the urinary system. [Background technology]

[0003] background A wide variety of catheters have been developed for treating calcified lesions, such as those in the vasculature associated with arterial disease. For example, treatment systems for percutaneous coronary intervention or peripheral angioplasty use angioplasty balloons to widen the calcified lesion and restore normal blood flow within the vessel. In these types of procedures, a catheter carrying the balloon is advanced through the vasculature along a guidewire until the balloon is aligned with the calcified plaque. The balloon is then pressurized (usually to more than 10 atmospheres) to expand the balloon within the vessel, pushing the calcified plaque back into the vessel wall and widening the blocked area of ​​the vasculature. However, conventional angioplasty balloons are not always successful in widening the calcified lesion or vasculature due to the stiffness and hardness of the calcified tissue and / or plaque.

[0004] More recently, catheters have been developed that include shock wave emitters (e.g., one or more electrode pairs) for generating shock waves inside an angioplasty balloon; this procedure is referred to as intravascular lithotripsy ("IVL"), a technology pioneered by the present applicant, Shockwave Medical, Inc. Shockwave devices can be particularly effective in treating calcified lesions because the acoustic pressure from the shock waves can crack and destroy lesions near the angioplasty balloon without damaging the surrounding tissue. In this device, a catheter is advanced over a guidewire through the patient's vascular system until it is positioned proximal to and / or aligned with the calcified lesion within a body cavity. The balloon is then inflated with a conductive fluid (using a relatively low pressure of 2-4 atmospheres) so that the balloon expands into contact with the lesion, thereby bringing the shock wave emitter into close apposition to the lesion. The shock wave emitter can then be activated to generate acoustic shock waves that propagate through the wall of the angioplasty balloon and into the lesion. Once the lesion has been disrupted by the acoustic shock waves, the balloon can be further expanded to increase the cross-sectional area of ​​the lumen and improve blood flow through the vessel.

[0005] For electrohydraulic generation of acoustic shock waves, a conductive solution (e.g., saline) may be contained within an enclosure surrounding the electrode or may be flowed to the electrode through a lumen. Modification of calcified plaque is achieved by generating acoustic shock waves within the catheter via an electrical discharge across the electrode. Energy released by the electrical discharge enters the surrounding fluid faster than the speed of sound, generating acoustic shock waves. Energy from the electrical discharge may also generate rapidly expanding and collapsing vapor bubbles, which result in additional shock waves. These shock waves propagate radially outward, modifying calcified plaque within the blood vessel. For laser generation of acoustic shock waves, a laser pulse is transmitted into the fluid within the catheter and absorbed by the fluid. This absorption process rapidly heats and vaporizes the fluid, thereby generating vapor bubbles that rapidly expand and collapse, and acoustic shock waves that propagate outward, modifying calcified plaque. Acoustic shock wave intensity can be increased if a fluid is selected that exhibits strong absorption at the laser wavelength used. These examples of IVL devices are not intended to be a comprehensive list of potential energy sources for generating IVL shock waves.

[0006] Conventional treatments for calcified lesions in a patient's vasculature often involve mechanical alterations to the blood vessel, particularly atherectomy surgical procedures, which carry a relatively significant risk of embolization (shedding of debris), abrupt closure (vascular collapse), avulsion (laceration of vascular tissue), and / or perforation (puncture of vascular tissue). The use of IVL in place of or in combination with conventional treatments for calcified lesions can significantly reduce the risks of embolization and perforation while providing improved therapeutic outcomes in the removal of calcified lesions.

[0007] Given these advances, currently available shockwave catheters are limited by the length of the balloon and the location of the emitter within that balloon. In patients with lesions longer than the standard length of a balloon, physicians may choose to proceed with repeated cycles of inflation, shockwave release, deflation, and balloon repositioning to provide shockwave treatment to the entire length of a given lesion. When used over repeated cycles, concerns arise regarding the structural integrity of the balloon and its ability to maintain a deflated profile to cross the lesion. Furthermore, any procedure or technique that adds more time than necessary to the patient on the table is likely to cause procedural complications and is therefore not well accepted in clinical cases.

[0008] Therefore, to reduce procedure time and costs, longer balloons are desired by physicians to treat longer lesions. Simply using a longer balloon may not be sufficient, as the distance from the emitter to the relatively distant portion of the longer balloon may result in insufficient shock wave intensity at the tip of the balloon. Furthermore, simply increasing the number of shock wave emitters may not be practical or possible, as adding emitters tends to increase the catheter's profile and complicate its design. Such catheters also require substantially higher energy output from the power source. Furthermore, a large number of emitters may reduce the flexibility and compliance of the balloon region of the catheter, limiting the treatment site that can be reached.

[0009] Thus, there is an unmet need for a catheter and emitter assembly design that can deliver shock waves to relatively long lesions within a patient, thereby minimizing the intraoperative time the patient is undergoing treatment. Summary of the Invention [Means for solving the problem]

[0010] Quick Overview The foregoing objectives are realized in a catheter including a set of movable emitters that can be repositioned while deployed within a patient. More specifically, the innovations of the present disclosure enable an end user (e.g., a physician) to physically move the emitters of an IVL device along the catheter inside a relatively long balloon and position the emitters at various locations alongside a desired long calcified lesion to destroy calcium with shockwave technology.

[0011] Various examples may allow a user to inflate a very long balloon (e.g., a balloon with a working length of 100-300 mm) and leave it in place within a long lesion, and then move any number of emitters to desired locations inside the inflated balloon along the length of the calcified lesion. This process can also be accomplished with a slightly inflated or semi-inflated balloon, depending on the calcium structure of the artery, without the need to reposition the balloon at all.

[0012] In one or more embodiments, a catheter for treating an occlusion in a body cavity includes an IVL balloon with emitters mounted on a steerable tube.

[0013] In one or more examples, the catheter is configured for in situ customizable placement of emitters along the length of the balloon, thereby enabling optimal application of shockwave therapy with minimal repositioning of the balloon required by the physician. Various catheter embodiments enable efficient application of acoustic energy to calcified regions of the vessel and avoid indiscriminate application of shockwave therapy to non-calcified regions of the vessel. Various embodiments also enable longer IVL balloons to be developed with relatively lower power requirements. Various catheter embodiments can improve the flexibility, trackability, and / or deliverability of the overall catheter.

[0014] The various examples described herein allow an end user to physically move the IVL emitter inside a very long balloon to position it at various locations in a long calcified lesion as desired to destroy calcium. According to one aspect of the present disclosure, a catheter for treating an occlusion in a body cavity includes an outer elongate member including a fluid lumen, a flexible enclosure secured to a distal region of the outer elongate member, the flexible enclosure being fillable with an electrically conductive fluid via the fluid lumen, an inner elongate member positioned within the outer elongate member and extending through the flexible enclosure to the distal region of the flexible enclosure, and a movable emitter member having an emitter assembly mounted on the movable emitter member and connected to a power source, the movable emitter member being disposed between the inner elongate member and the outer elongate member and being longitudinally movable between the inner elongate member and the outer elongate member.

[0015] In a first configuration of the movable emitter member, the emitter assembly may be at a first location, and in a second configuration of the movable emitter member, the emitter assembly may be at a second location distal to the first location.

[0016] The emitter assembly may be disposed proximal to the flexible enclosure in the first configuration and within the flexible enclosure in the second configuration.

[0017] The flexible enclosure may have a working length l, the emitter assembly may include multiple shockwave emitters, and the distance between the most proximal and most distal shockwave emitters may be less than or equal to 0.5l.

[0018] The catheter may further include a proximal hub, wherein the outer elongate member, the inner elongate member, and the movable emitter member extend to the proximal hub, and translation of the movable emitter member along the inner elongate member at the proximal hub can move the emitter assembly.

[0019] Translation of the movable member at the proximal hub a distance d can move the emitter assembly longitudinally a distance d.

[0020] The proximal hub may include a distal end opening that is fluid-sealed to the proximal end of the outer elongate member.

[0021] The inner elongate member of the catheter may include indicia correlating to the longitudinal position of the emitter assembly within the flexible enclosure.

[0022] The proximal hub may include a distal diaphragm seal and a proximal diaphragm seal. The inner elongate member and the movable emitter member may each extend through the distal diaphragm seal. The inner elongate member may extend through the proximal diaphragm seal.

[0023] The proximal hub may include a position stabilizer having a first anchor at a first location on the hub and a second anchor at a second location on the hub proximal to the first location, and the movable emitter member includes a proximal end translatable between the first anchor and the second anchor.

[0024] At least one of the inner elongate member and the movable emitter member may comprise polytetrafluoroethylene.

[0025] The inner elongate member may have an outer diameter d1, and the movable emitter member may include a lumen having a diameter d2 that is at least 0.002 inches larger than d1.

[0026] The emitter assembly may include an emitter centering member including a proximal band, a distal band, and a plurality of flexible beams connecting the proximal ring to the distal ring, each strut having a central region extending radially outward.

[0027] The flexible enclosure may include an expanded state and a contracted state, and when the flexible enclosure is in the expanded state, the central region may extend further radially outward than when the flexible enclosure is in the contracted state.

[0028] The emitter assembly may include one or more shockwave emitters, and a central region of the multiple beams may space the emitters from the wall of the flexible enclosure.

[0029] The emitter centering member may include one or more of a polymer and a metal.

[0030] The flexible enclosure may include an angioplasty balloon having a working length l of at least 50 mm.

[0031] According to one aspect of the present disclosure, a method for performing intravascular lithotripsy includes introducing a catheter into a body cavity, the catheter including an elongate member extending from a proximal end to a distal end, a movable emitter member movable along the elongate member and including a shock wave emitter assembly, and an inflatable flexible enclosure secured to a distal region of the elongate member. The method further includes advancing the catheter through the body cavity until the flexible enclosure is adjacent an occlusion in the body cavity, inflating the flexible enclosure with a fluid via a fluid lumen of the catheter, moving the emitter member along the elongate member, and supplying power to the shock wave emitter assembly to generate one or more shock waves.

[0032] Moving the emitter member may include moving the emitter member such that the shockwave emitter assembly moves between a first location proximal to the flexible enclosure and a second location within the flexible enclosure.

[0033] Moving the emitter member may include moving the emitter member such that the shockwave emitter assembly moves between a first location within the flexible enclosure and a second location within the flexible enclosure.

[0034] The method may further include imaging the body cavity with at least one of x-ray fluoroscopy, optical coherence tomography, and intravascular ultrasound.

[0035] Moving the emitter member may include moving a proximal end of the emitter member.

[0036] The method may further include correlating movement of the emitter assembly with movement of the emitter member at a proximal end thereof by using indicia located along a proximal region of the elongate member.

[0037] According to one aspect of the present disclosure, an emitter centering member for an IVL catheter includes a proximal band, a distal band longitudinally spaced from the proximal band, and a plurality of flexible beams connecting the proximal ring to the distal ring, each flexible beam including a central region compressibly extending laterally outward.

[0038] According to one aspect of the present disclosure, a handle for an IVL device includes a proximal end, an elongate member extending from the proximal end, a movable arm movably disposed on the elongate member and including a proximal diaphragm seal and a power port, a distal arm disposed distally of the movable arm and including a distal diaphragm seal and a fluid port, and a stabilizing bar extending from the proximal end to the distal arm.

[0039] The movable arm may include a second fluid port.

[0040] The movable arm may include a third fluid port.

[0041] According to one aspect of the present disclosure, a catheter for treating an occlusion in a body cavity includes an elongate member including a fluid lumen; a flexible enclosure secured to a distal region of the outer elongate member, the flexible enclosure being fillable with a conductive fluid via the fluid lumen and having a working length l; and a movable emitter member having an emitter assembly mounted on the movable emitter member and connected to a power source, the emitter assembly comprising a plurality of emitters, wherein a distance from a proximal-most emitter to a distal-most emitter is less than or equal to l / 2, and the movable emitter member is longitudinally translatable within the flexible enclosure. [Brief explanation of the drawings]

[0042] Exemplary aspects of the present disclosure are described in detail below with reference to the following drawings: It is intended that the embodiments and figures disclosed herein should be considered illustrative and not restrictive.

[0043] [Figure 1A] FIG. 1A shows an exemplary catheter having a movable array of emitters inside an angioplasty balloon at a proximal location, according to an embodiment of the present disclosure.

[0044] [Figure 1B] FIG. 1B illustrates an exemplary catheter having a movable array of emitters inside an angioplasty balloon at a distal location, according to an embodiment of the present disclosure.

[0045] [Figure 1C] FIG. 1C shows a cross-sectional view of one of the exemplary catheters and steerable emitters inside the angioplasty balloon shown in FIG. 1B.

[0046] [Figure 1D] FIG. 1D illustrates an exemplary wiring configuration for an exemplary catheter and steerable emitter inside an angioplasty balloon according to an embodiment of the present disclosure.

[0047] [Figure 1E] FIG. 1E illustrates an exemplary catheter having a movable array of emitters inside a lumen directly adjacent to an angioplasty balloon in a paired configuration with inflating and deflating balloons, according to an embodiment of the present disclosure.

[0048] [Figure 1F] FIG. 1F illustrates an exemplary catheter having a movable array of emitters inside a tapered angioplasty balloon at a distal location, according to an embodiment of the present disclosure.

[0049] [Figure 1G] FIG. 1G illustrates an exemplary catheter having a movable array of emitters inside an angioplasty balloon configured for rapid exchange delivery according to an embodiment of the present disclosure.

[0050] [Figure 1H] FIG. 1H illustrates an exemplary catheter having a movable array of emitters inside an angioplasty balloon configured for rapid exchange delivery, according to an embodiment of the present disclosure.

[0051] [Figure 1I] FIG. 1I shows a cross-sectional view of an exemplary catheter having a movable array of emitters according to an embodiment of the present disclosure.

[0052] [Figure 2A] FIG. 2A is a diagram illustrating an exemplary catheter within a vasculature, the catheter having a movable array of emitters inside an angioplasty balloon at a distal location, according to an embodiment of the present disclosure.

[0053] [Figure 2B] FIG. 2B is a diagram illustrating an exemplary catheter within a vasculature, the catheter having a movable array of emitters inside an angioplasty balloon at a central location, according to an embodiment of the present disclosure.

[0054] [Figure 2C]FIG. 2C is a diagram illustrating an exemplary catheter within a vasculature, the catheter having a movable array of emitters inside an angioplasty balloon at a proximal location, according to an embodiment of the present disclosure.

[0055] [Figure 3] FIG. 3 is a flow chart illustrating a sequence for shockwave treatment of a lesion using a movable array of emitters within an angioplasty balloon, according to an embodiment of the present disclosure.

[0056] [Figure 4A] FIG. 4A illustrates an exemplary proximal handle for a catheter having a movable emitter assembly, according to an embodiment of the present disclosure.

[0057] [Figure 4B] FIG. 4B shows details of the proximal section of the stabilizer structure shown in FIG. 4A according to an embodiment of the present disclosure.

[0058] [Figure 5A] FIG. 5A illustrates an exemplary proximal section of a movable emitter carrier according to an embodiment of the present disclosure.

[0059] [Figure 5B] FIG. 5B illustrates an exemplary distal section of a movable emitter carrier according to an embodiment of the present disclosure.

[0060] [Figure 6A] FIG. 6A illustrates an exemplary catheter having a movable emitter assembly with an emitter centering feature in a radially folded configuration according to an embodiment of the present disclosure.

[0061] [Figure 6B] FIG. 6B illustrates the exemplary catheter of FIG. 6B with the emitter centering feature in a radially expanded configuration, according to an embodiment of the present disclosure.

[0062] [Figure 6C]FIG. 6C illustrates an exemplary catheter having a movable emitter assembly with an emitter centering feature according to an embodiment of the present disclosure.

[0063] [Figure 6D] FIG. 6D illustrates an exemplary emitter centering structure in a radially folded configuration according to an embodiment of the present disclosure.

[0064] [Figure 6E] FIG. 6E illustrates an exemplary emitter centering structure in a radially expanded configuration according to an embodiment of the present disclosure.

[0065] [Figure 7] FIG. 7 illustrates an exemplary catheter having emitter centering features according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0066] Detailed Description The following description is presented to enable any person skilled in the art to make and use the various embodiments and aspects thereof disclosed herein. Descriptions of specific devices, assemblies, techniques, and applications are provided by way of example only. Various modifications to the examples described herein will be readily apparent to those skilled in the art, and the general principles described herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments and aspects thereof. Thus, the various embodiments and aspects thereof are not intended to be limited to the examples described and shown herein, but are to be accorded the scope consistent with the claims.

[0067] Efforts have been made to improve the design of electrode assemblies included in shock wave and directional cavitation catheters. For example, low-profile electrode assemblies have been developed that reduce the crossing profile of the catheter, allowing the catheter to more easily navigate calcified vessels and deliver shock waves into more severely occluded areas of the vasculature. Examples of low-profile electrode designs can be found in U.S. Pat. Nos. 8,888,788, 9,433,428, and 10,709,462, as well as U.S. Patent Application Publication No. 2021 / 0085383, all of which are incorporated herein by reference. An example of a low-profile catheter having electrodes configured for insertion after balloon dilation can be found in U.S. Pat. No. 10,357,264, which is incorporated herein by reference. Other catheter designs have improved shock wave delivery, for example, through specific electrode structures and configurations, thereby directing shock waves in a forward direction to disrupt tighter and more difficult-to-cross occlusions within the vasculature. Examples of forward-activation catheter designs can be found in U.S. Patent Nos. 10,966,737, 11,478,261, and 11,596,423, as well as U.S. Patent Application Publication Nos. 2023 / 0107690 and 2023 / 0165598, all of which are incorporated herein by reference. U.S. Patent No. 11,779,363, incorporated herein by reference, describes spacing of shock wave emitters to promote constructive interference of acoustic waves.

[0068] As used herein, the term "electrode" refers to a conductive element (typically made of a metal or alloy) that receives and then emits current to another conductive element. Thus, as used herein, an "electrode pair" refers to two electrodes positioned adjacent to one another such that current supplied to one electrode is transmitted across a gap (also called a "spark gap") between the two electrodes (e.g., between a first electrode and a second electrode, or vice versa, with an insulator separating the two electrodes if necessary, and through a conductive fluid or gas between them). Furthermore, as used herein, an "emitter" refers to a structure having one or more electrode pairs. Emitters may be singular, paired, or otherwise arranged together so as to be electrically connected as an emitter assembly. Shock waves can be generated at each electrode pair of an emitter. In some circumstances, one or more electrode pairs positioned across one or more emitters may be referred to as an "electrode assembly."

[0069] In contrast to current balloons of similar length used clinically, these balloons used for IVL applications may need to be formed from materials with higher tensile strength or greater elasticity.

[0070] Typically, long calcified lesions in arteries and other vascular systems present challenges for many interventional devices and users. A user (e.g., a physician) must assess the length and diameter of the calcified lesion before determining the diameter and length of the balloon catheter they wish to use during the procedure. To treat relatively long calcified lesions, a user may prefer to use a single long balloon for treating such lesions, selecting a balloon with a length of approximately one hundred to three hundred millimeters (100 mm to 300 mm) and a diameter of 2 to 30 millimeters when inflated.

[0071] In the current market for IVL devices, the use of longer balloons presents different catheter profiles and therefore different requirements for ensuring proper treatment function. When considering modifications to achieve treatment performance with longer balloons, it is important to keep in mind that there is a direct correlation between the number of emitters (given a fixed energy source) and the effectiveness of IVL therapy. In other words, as the number of emitters increases to accommodate longer balloons for longer lesions, the available energy to satisfy the increased number of emitters decreases, potentially resulting in reduced IVL efficacy. While this problem can be partially addressed by adding more channels to the IVL generator and system, this solution results in a catheter with more circuits and wires, resulting in a larger profile that may have more difficulty reaching smaller peripheral vasculature or crossing severely occluded lesions. Currently available IVL devices have two to five emitters within the balloon, where the emitters are adhesively bonded to the catheter shaft and therefore fixed in place. Additionally, these devices have balloons with diameters of approximately twelve millimeters to sixty millimeters (12 mm to 60 mm), and the working length of the balloon along the catheter is one hundred ten centimeters to one hundred thirty-eight millimeters (110 mm to 138 mm). This allows the physician to move the balloon over the catheter guidewire along the length of the lesion to treat the entire length of the lesion through cycles of positioning, inflation, shockwave therapy, and deflation. The emitters on these devices can deliver pulses one at a time, two at a time, all at the same time, and / or in an alternating or sequential pattern along the length of the catheter and balloon.

[0072] Described herein are catheters, balloons, and IVL circuits incorporating design elements that enable treatment of relatively long calcified lesions using an enclosure with an array of movable emitters. In such implementations, it is generally not necessary to undergo the inflation-deflation cycles that require repositioning the balloon for shockwave therapy as described above. Rather, a single balloon allows for movement of emitters within the balloon to deliver shockwave treatment to the target area of ​​a given long lesion. This can be accomplished with a slightly inflated or semi-inflated long balloon, depending on the calcium stenosis in the artery or other vessel.

[0073] 1A shows an exemplary catheter 100 having a steerable emitter array 110 inside an angioplasty balloon 108 at a proximal location, according to one or more embodiments. The catheter 100 includes an outer shaft (or outer elongate member) 102, a steerable emitter carrier 104, and an inner shaft 106. The steerable emitter carrier 104 may be tubular and define an internal lumen. Similarly, the outer shaft 102 may be tubular and define a lumen. The steerable emitter carrier 104 may be concentric with the outer shaft 102. The steerable emitter carrier 104 may also be concentric with the inner shaft 106. The angioplasty balloon 108 is secured (e.g., glued) to the outer shaft 102 at a proximal end and secured to the inner shaft 106 at a distal end. The balloon 108 is shown as inflated, and the volume of the balloon 108 is inflated using a conductive fluid (e.g., saline), a contrast agent, or a combination thereof. In some embodiments, the inner shaft 106 is a hollow tube that can move over and along a guidewire (not shown), which can pass through the inner shaft 106 to guide the catheter 100 to target anatomical structures and lesions within the patient's vasculature. The movable emitter array 110 is shown in the exemplary embodiment having a first emitter 112, a second emitter 114, a third emitter 116, and a fourth emitter 118. In alternative embodiments, the movable emitter array 110 can have more or fewer emitters, for example, any number of emitters, from one to six emitters. Given sufficient power sources and corresponding circuitry, the movable emitter array 110 can have more than six emitters.

[0074] In some embodiments, the angioplasty balloon 108 has a diameter of at least 1 millimeter (mm) and up to 25 mm. In some embodiments, the angioplasty balloon has a working length of at least 10 mm and up to 350 mm. In some embodiments, the catheter 100 has a working length of at least 100 cm and up to 350 cm. The working length of the movable emitter carrier within the volume of the balloon can be up to the entire length of the balloon. In some embodiments, the distance from the most proximal emitter to the most distal emitter can be up to the entire working length of the balloon.

[0075] In some embodiments, as shown, each emitter includes a cylindrical sheath (also referred to as a ring or band) mounted on and surrounding the movable emitter carrier 104. The cylindrical sheath is formed from a conductive material (e.g., a metal or alloy) that forms a first electrode surface of an electrode pair. The sheath includes a cutout area (e.g., a central circular hole, an arcuate cutout on the edge of the sheath, etc.) that provides an unobstructed electrical path to a second conductive material, specifically a conductive member (e.g., copper wire, a flat coil, etc.) positioned below or within the movable emitter carrier 104, thereby forming the second electrode surface of the electrode pair. In this emitter configuration, the conductive portion of the sheath may be referred to as the outer electrode, and the wiring may be referred to as the inner electrode. Current delivered across the emitter can jump across the space between the two electrode surfaces, also referred to as a "spark gap," generating the shock wave described above. Either of the electrode surfaces can be an anode or a cathode depending on the polarity of the pulse delivered across the emitter. The spark gaps may be spaced so as to be circumferentially offset along the movable emitter carrier to provide a more circumferentially uniform acoustic output.

[0076] In many implementations, each emitter will have two electrode pairs, and current can pass from one electrode pair on the emitter to the other by flowing across the conductive material of the sheath. The electrode pairs on each emitter can be positioned to generate shock waves in opposite directions (i.e., arranged 180 degrees apart from each other around the catheter) or in converging or biased directions (i.e., arranged less than 180 degrees apart from each other around the catheter). In alternative implementations, an emitter can have three, four, five, or six electrode pairs arranged around the circumference of the emitter. The various emitters of the movable emitter array 110 can be electrically connected to each other in series or parallel over one or more electrical channels.

[0077] As part of the catheter 100, the balloon 108 has a proximal end and a distal end, with the proximal end of the balloon 108 attached to the balloon shaft 102 and the distal end of the balloon 108 attached to the inner shaft 106. The balloon 108 is attached at both locations such that the interior volume of the balloon 108 is sealed, for example, by adhesives, clamps, heat seals, pressure seals, or a combination thereof. At the proximal end, the balloon 108 is attached around the balloon shaft 102 such that the space between the balloon shaft 102 and the movable emitter carrier 104 can be used as a channel for fluid to enter and inflate the balloon 108 (and correspondingly, exit the balloon 108 and deflate it). In some embodiments, another type of shielding enclosure (e.g., a cap or flexible polymer tubing) may be used in place of the angioplasty balloon.

[0078] The catheter 100 can be deployed to a target location within a patient with the balloon 108 in a deflated configuration, with all of the movable emitter carriers 104 in a retrieved position within the outer shaft 102. A guidewire can be used to guide the catheter 100 to the target tissue for treatment. The balloon 108 can then be inflated to a pressure appropriate for shock wave therapy (e.g., approximately 4 atm, or a pressure sufficient to ensure that the outer surface of the balloon 108 contacts and generally conforms to the contours of the surrounding tissue). In various embodiments, the fluid used to fill the volume of the balloon 108 can be saline or other conductive fluid, a contrast agent, or a mixture thereof. The fluid filling the balloon 108 can be delivered to the interior of the balloon 108 through a channel formed by the space between the balloon shaft 102 and the movable emitter 104. In alternative embodiments, a separate fluid lumen can be used to provide the fluid. In some embodiments, the balloon is fixedly positioned at the distal region of the inner shaft, and only the movable emitter lumen is translatable from outside to inside the balloon volume.

[0079] Materials that can be used for components such as the outer shaft 102, the movable emitter carrier 104, and the inner shaft 106 can be extruded or molded polymers, or functional equivalents that are safe for use inside a patient. Such materials can include polyether block amides (e.g., Pebax), polytetrafluoroethylene (PTFE), nylon, or other polymers.

[0080] With the balloon 108 inflated, the movable emitter carrier 104 can be moved to various positions along the length of the inner shaft 106 (while remaining within the volume of the balloon 108) where the emitters of the movable emitter array 110 can be activated to generate shock waves at desired locations proximate portions of the target tissue (e.g., calcified blood vessels, aorta, or mitral valve tissue, etc.).

[0081] As shown, the movable emitter array 110 includes four individual emitters, a first emitter 112, a second emitter 114, a third emitter 116, and a fourth emitter 118, positioned along the emitter carrier 104 in order from the most distal to the most proximal emitter. In various implementations, each emitter in the movable emitter array 110 may have one or more electrode pairs. In various implementations, all of the emitters in the movable emitter array 110 may be wired onto a single electrical channel so that current is supplied to all emitters during each cycle of activation, meaning that the first emitter 112, the second emitter 114, the third emitter 116, and the fourth emitter 118 are all on the same single electrical channel, as shown in FIG. 1A. Using only one electrical channel minimizes the required physical wiring, helping to minimize the width of the catheter 100 and thereby minimize the overall profile of the catheter 100. In an alternative implementation, the emitters can be wired to two or more electrical channels, for example, using the diagram of FIG. 1A , with the first emitter 112 and the second emitter 114 on one channel and the third emitter 116 and the fourth emitter 118 on a second channel. Using two or more electrical channels allows for greater operational flexibility in which emitters are activated, for example, activating only a more distal pair of emitters on the catheter to directionally bias the generated shock waves. Similarly, the operational flexibility of using two or more electrical channels may extend the life of the catheter device, for example, allowing a more proximal pair of emitters to remain activated if a more distal pair of emitters fails.

[0082] FIG. 1B illustrates an exemplary catheter 100 having a movable array of emitters 110 inside an angioplasty balloon 108 at a distal location. As shown, the movable emitter carrier 104 extends distally along the catheter 100, covering more of the surface of the inner shaft 106 while remaining within the volume of the balloon 108. In actual applications, a physician may choose to initiate a shockwave therapy regimen with the movable emitter array 110 at a distal location as shown in FIG. 1B, a proximal location as shown in FIG. 1A, or an intermediate location, as deemed appropriate for treating the intended patient and target tissue. Also shown are marker bands, specifically a proximal marker band 120 and a distal marker band 122, positioned next to the proximal and distal ends of the balloon 108 and visible during the procedure under radiography (e.g., fluoroscopy). For radiographic visibility, the marker bands can be fabricated from radiopaque materials such as iodine, barium, tantalum, bismuth, palladium, platinum, iridium, stainless steel, or alloys, oxides, sulfates, or other combinations thereof. The positioning of the proximal and distal marker bands 120, 122 on the proximal and distal ends of the balloon 108, respectively, allows the operator to view the location of the balloon and catheter 100 within the patient.

[0083] FIG. 1C shows a cross-sectional view of the exemplary catheter 100 inside an inflated angioplasty balloon 108 as shown in FIG. 1B and one of the movable emitters (first emitter 112 as shown). FIG. 1C further details how wires can be electrically connected to the emitters on the movable emitter carrier 104. A first wire 124 is mounted within one of grooves 128 formed in the movable emitter carrier 104 and aligned with a first spark gap 112a formed in the emitter ring 112. Similarly, a second wire 126 is mounted within a separate one of the grooves 128 formed in the movable emitter carrier 104 and aligned with a second spark gap 112b formed in the emitter ring 112c. Both the first wire 124 and the second wire 126 are insulated wires, but where the first wire 124 is aligned with the first spark gap 112a and the second wire 126 is aligned with the second spark gap 112b, the wires 124, 126 are exposed to form electrode surfaces that mate with respective opposing electrode surfaces of the emitter ring 112c. Thus, the first emitter 112 has two electrode pairs, one located in the first spark gap 112a between the first wire 124 and the emitter ring 112c, and the other located in the second spark gap 112b between the second wire 126 and the emitter ring 112c. In an alternative implementation, the first wire 124 and the second wire 126 can be embedded within the material of the movable emitter carrier 104 to minimize the cross-sectional profile of the overall catheter 100. In other alternative implementations, the first wire 124 and the second wire 126 may be sandwiched or pressed between the movable emitter carrier 104 and each emitter. The first wire 124 and the second wire 126 may be secured to the movable emitter carrier 104 by being glued to the surface of the movable emitter carrier 104, wrapped with a coating on the surface of the movable emitter carrier 104 (e.g., a constriction wrapped with a polymer material surrounding the wires and lumens), or a combination thereof.

[0084] In some embodiments, on a movable emitter carrier, each emitter may be spaced 3 to 20 millimeters apart. The emitters may be electrically grouped (wired together) on various channels of a circuit, where the emitters may be wired individually, in pairs, triplets, etc., and may be wired in series or parallel. The power source supplying electricity to the emitters may provide a voltage in the range of about 1,000 V to about 15,000 V.

[0085] 1D shows an exemplary wiring configuration for an exemplary catheter and movable emitter inside an angioplasty balloon, according to one or more embodiments. A close-up view shows a first conductor 123 extending from a power source (not shown) to a proximal-most emitter 118. The emitter 118 is electrically connected to a first return conductor 127 extending proximally to the power source. Current from a high-voltage pulse flows from the power source through the first conductor 123 to the proximal-most emitter 118, generating a shock wave in the emitter 118 (described above). The current then flows through the second conductor 125 to the second-proximal emitter 116, generating a shock wave in the emitter 116. This continues until a shock wave has been generated in each electrode pair electrically connected to the emitters 116, 118. The current then returns to the power source through return conductors (e.g., first and second return conductors 127, 129). Although only one hole (indicating the location of an electrode pair from which shock waves can be generated) is shown per emitter, multiple electrically connected electrode pairs are possible at each emitter. In some embodiments, these conductors have conductive regions connected to the electrodes, or comprise insulated wires whose conductive region surfaces form the electrodes. In some embodiments, the conductors or wires are arranged so that shock waves are generated sequentially from the most distal emitter to the most proximal emitter.

[0086] 1E shows an exemplary catheter 100 having a movable array of emitters inside a lumen immediately adjacent to an angioplasty balloon in a balloon-inflated / deflated pair configuration, according to one or more embodiments. As shown, a first emitter 112, a second emitter 114, a third emitter 116, and a fourth emitter 118 are all located on a movable emitter carrier 104 within the outer shaft 102 and proximal to the balloon 108. The distal end of the movable emitter carrier 104 may extend partially into the volume of the balloon 108 when inflated or deflated, or the movable emitter carrier 104 may be completely retracted within the circumference of the outer shaft 102 before and / or after deployment.

[0087] An advantage of positioning the emitter within the outer shaft 102 during deployment at the target tissue site is that the deflated balloon 108 can be folded or crimped to have virtually the same diameter as the outer surface of the inner shaft 106 during delivery. This diameter can be between 5 and 8 French gauge. In some embodiments, the deflated outer diameter is up to 8 French gauge. Thus, the catheter 100 has a smaller cross-sectional profile for delivery to a vessel or lesion than if the emitter were present and statically positioned within the balloon 108 on the inner shaft 106. While emitters such as those used in IVL devices may increase the overall catheter diameter by only 1 French or less during deployment, this difference in cross-sectional profile is significant for both enabling crossing certain vascular lesions and fitting within other vascular delivery systems. Additionally, keeping the emitter collected inside the outer shaft 102 while in the deflated balloon 108 configuration reduces the risk that the balloon material will snag or tear on the emitter while traveling through the patient's vascular system.

[0088] FIG. 1F shows an exemplary catheter having a movable array of emitters 110 inside a tapered angioplasty balloon 109 at a distal location. The use of a tapered angioplasty balloon 109, whose distal end is narrower than its proximal end, can provide improved access to vasculature that may be partially occluded by plaque (e.g., a chronic total occlusion, "CTO"), where the narrow end of the tapered angioplasty balloon 109 can act as a wedge to push into and through the plaque. In situations where the tapered angioplasty balloon 109 is in close proximity to or in contact with the device-facing surface of the vascular plaque, the movable emitter carrier 104 can be positioned at a distal location to generate shock waves at the entry point of the vascular plaque to disrupt the surrounding lesion calcification. Relaxing or loosening the vasculature at that location can then allow the tapered angioplasty balloon 109 to be pushed further along the vessel and through the vascular plaque, ultimately generating shock waves along the entire length of the calcified lesion. Tapered angioplasty balloons can also be implemented in body lumens that are naturally tapered, hi some embodiments, the tapered angioplasty balloon has a tapered working region with a taper angle (e.g., angle α) of up to 20 degrees.

[0089] In the example shown in FIGS. 1A-1F, the catheter may be configured to be advanced into a body lumen over a guidewire (not shown), commonly referred to as an “over-the-wire” or “OTW” configuration. In an alternative implementation, as shown in FIGS. 1G and 1H, the catheter may be arranged as part of a “rapid-exchange” or “Rx” configuration, in which instruments are swapped in and out of the patient through a larger lumen during a procedure. FIG. 1G illustrates a catheter 100 in accordance with one or more embodiments of the present disclosure. The catheter 100 of FIG. 1G includes a pathway for a guidewire 150 for one rapid-exchange configuration. The guidewire 150 may extend from the distal end of the catheter 100 within the lumen of the inner shaft 106, exit the inner shaft 106 distal to the balloon 108, re-enter the catheter 100 proximal to the balloon 108, and extend proximally inside the lumen of the outer shaft 102. Such a configuration may make it easier to move the emitter carrier 104 in and out of the balloon 108 and to different locations within the balloon 108. The emitter carrier 104 moves back and forth on a stationary inner rail 152 and may extend proximally to the catheter handle. The inner rail 152 may be coupled to the distal tip of the balloon to keep an Rx guidewire stable during the procedure. A rapid-exchange guidewire exit 151 may be proximal to the distal balloon 108 and distal to the proximal end of the catheter 100 (not shown in FIG. 1G). The catheter 100 may include a fluid lumen 160 extending through the outer shaft 102 for delivering and removing fluid to and from the interior of the balloon 108. It should be readily understood that such a fluid lumen may be used in both the OTW and Rx configurations of the catheter 100.

[0090] FIG. 1H shows a catheter 100 in another configuration of a rapid exchange system, according to one or more examples. The catheter 100 of FIG. 1H includes an inner shaft 106 having a lumen for a guidewire 150 extending through a balloon 108. A movable emitter member 104 slidably moves along the inner shaft 106 and may be retractable into the outer shaft 102. The catheter 100 includes a guidewire exit port 151 distal to the catheter proximal end (not shown in FIG. 1H). Advantageously, the guidewire 150 in both the configurations shown in FIGS. 1G and 1H need not extend along the entire length of the catheter 100.

[0091] FIG. 1I shows a cross-sectional view of an exemplary catheter 2000 in the region between the proximal handle and the movable emitter assembly, according to one or more embodiments. The catheter 2000 includes an inner shaft 2010. In one or more embodiments, the inner shaft 2010 is tubular and may define a guidewire lumen to accommodate a guidewire (not shown) through which the catheter 2000 can be delivered. A movable emitter carrier 2020 is movably disposed along the inner shaft 2010. The movable emitter carrier 2020 may be tubular and define a lumen. The movable emitter carrier 2020 may include one or more wires (or another form of energy guide) connecting one or more emitters to a power source. The movable emitter carrier 2020 may be formed with grooves or lumens for wires (as described below) to reduce the overall profile of the catheter 2000. The movable emitter carrier 2020 is disposed between the inner shaft 2010 and the outer shaft 2030. In one or more embodiments, the outer shaft 2030 may be at least partially formed from hypotube. The outer shaft 2030 may also include an outer layer 2040. The outer layer 2040 may include a braided structure to provide structural support to the catheter 2000 as it is navigated through a body lumen. In some embodiments, the movable emitter carrier 2020 has an inner diameter that is larger than the outer diameter of the inner shaft 2010. In some embodiments, the movable emitter carrier inner diameter is at least 50 micrometers (μm) larger than the outer diameter of the inner shaft 2010.

[0092] In various embodiments, a catheter having a movable emitter carrier with one or more shock wave emitters may include a relatively long enclosure (e.g., an angioplasty balloon). For example, the enclosure may have a working length that is 50% to 200% longer than the end-to-end distance from the most proximal emitter to the most distal emitter. For example, the enclosure may have a working length 1, and the distance between the most proximal and most distal shock wave emitters may be less than or equal to 0.51. To use such a device, the balloon may be advanced through a body cavity to the lesion. The user may then inflate the balloon with a fluid (e.g., saline) to a relatively low pressure (e.g., less than 5 atm) or until the working area of ​​the balloon is adjacent to (i.e., in contact with) the lesion. Upon inflation, an emitter assembly mounted on the movable emitter carrier may be advanced through the balloon volume to a first location (e.g., a location proximal to the balloon) to treat the lesion or a portion of the lesion at the first location with shock wave therapy. The movable emitter carrier can then be further advanced to a second location (e.g., a location distal to the first location) to treat a new lesion or a new region of the same lesion. In some embodiments, treatment can begin at the distal region of the balloon or at the central region of the balloon. Advantageously, the shockwave therapy can be customized for any particular lesion. For example, if there is a greater degree of calcification in the distal region of the balloon than in the proximal region, more shockwaves may be generated by the emitter at the distal location than at the proximal location. By adjusting the shockwave therapy in this way, unnecessary excessive shockwave generation can be avoided, preserving the life of the device. Furthermore, such a device is less complex to design than separately supplying power (e.g., by electrical wires) to multiple emitters positioned along the length of an angioplasty balloon.

[0093] 2A-2C illustrate an exemplary catheter within a vasculature, the catheter having a movable array of emitters inside an angioplasty balloon, shown in a distal position in FIG. 2A, a central position in FIG. 2B, and a proximal position in FIG. 2C. As shown, calcified regions of the vascular tissue are indicated by "C," and regions of the vascular tissue where the calcification has been broken apart by shock waves are indicated by "B." Starting in FIG. 2A, an inflated balloon 108 extends along the entire length of the vascular tissue containing the calcification. A movable emitter carrier 104 extends along the length of the inner shaft 106 to the distal end of the balloon 108, and a movable emitter array 110 is positioned at the distal end of the movable emitter carrier 104. Thus, the movable emitter array 110 is adjacent to the calcification at the distal end of the target lesion within the vascular tissue. As shown, the emitters of the movable emitter array 110 generate shock waves that disrupt calcification in the distal portion of the lesion.

[0094] 2B, the movable emitter carrier 104 is pulled back proximally along the length of the catheter 100 so that the movable emitter array 110 is adjacent to calcifications in the central region of a target lesion in the vascular tissue. As shown, the emitters of the movable emitter array 110 generate shock waves that destroy the calcifications in the central portion of the lesion. It should be understood that the central region of a long calcified lesion may require multiple repositioning of the movable emitter array 110 to provide treatment to the entire length of the central region of the calcified lesion.

[0095] 2C, the movable emitter carrier 104 is pulled back proximally along the length of the catheter 100 so that the movable emitter array 110 is adjacent to the calcification at the proximal end of the target lesion within the vascular tissue. As shown, the emitters of the movable emitter array 110 generate shock waves that destroy the calcification in the proximal portion of the lesion.

[0096] It should be understood that more than one cycle of shockwave generation can be used to break up the calcification in any given region of the calcified tissue, and that various regions of the calcified tissue may require relatively more or less shockwave treatment compared to one another. It should be further understood that the sequence of translating the movable emitter array 110 can proceed from distal to proximal as illustrated in Figures 2A-2C, but can alternatively proceed in a proximal-to-distal sequence, a medial-to-proximal sequence, or a medial-to-distal sequence. Furthermore, the movable emitter array 110 can be moved to repeat the treatment two or more times at locations along the calcified tissue.

[0097] FIG. 3 is a flowchart illustrating a sequence for shockwave treatment of a lesion using a movable array of emitters within an angioplasty balloon, according to one or more embodiments. In step 301, an IVL device is deployed into a body cavity (e.g., a blood vessel) along a guidewire. In step 302, an enclosure (e.g., a balloon) of the IVL device is positioned across or along the lesion to be treated. In step 303, the enclosure is inflated until the working area of ​​the balloon conforms closely to the body cavity wall and the lesion. In some embodiments, the enclosure is inflated to a pressure of less than 5 atm. In some embodiments, the enclosure is inflated to a pressure of at least 1 atm and up to 4 atm. In step 309, once the movable array of emitters is in a recovery position within the outer shaft (i.e., proximal to the balloon), the emitters are advanced within the enclosure to a first target area of ​​the lesion. In step 305, shockwaves are generated in the movable array of emitters (e.g., by delivering high-voltage or laser pulses). In step 306, the user determines whether different regions of the lesion require shockwave treatment. If yes, steps 304-306 are repeated. If no, the enclosure is deflated in step 307. Upon deflation, the IVL device is withdrawn in step 308. Optionally, before withdrawal of the IVL device and after shockwave treatment, the enclosure is inflated to a pressure sufficient to radially expand the body cavity. In some embodiments, this second inflation pressure is higher than the pressure in step 303. In some embodiments, the second inflation pressure is greater than 5 atm. In some embodiments, the second inflation pressure is at least 4 atm and at most 12 atm. In some embodiments, in step 310, the movable array of emitters may be withdrawn into the outer shaft before the enclosure is deflated and the catheter is withdrawn. In some embodiments, the method further includes imaging the lesion (e.g., by x-ray fluoroscopy, intravascular ultrasound, and / or optical coherence tomography).The method may also include the step of deflating and inflating the balloon with a liquid between rounds of shock wave treatment to remove any air bubbles that have accumulated inside the balloon.

[0098] 4A shows an exemplary proximal handle 1000 for a catheter having a movable emitter assembly and a balloon assembly, according to one or more embodiments. The handle 1000 can be used to advance or retrieve a movable emitter carrier 1302, which includes a movable emitter assembly at its distal region (not shown). The handle 1000 includes a fluid port 1102 extending from the distal Y-arm 1100 and fluidly connected to a lumen of the outer shaft 1500. The movable emitter carrier 1302 is slidably disposed inside the outer shaft 1500 and extends proximally from the proximal end of the outer shaft 1500 through a fluid shield connector 1104. In one or more embodiments, the connector 1104 may include a luer fitting.

[0099] The movable emitter carrier 1302 extends to a proximal Y-arm 1300, which is slidably disposed on the inner shaft 1010. The proximal Y-arm 1300 includes a power connector port 1304 through which a power source can be connected to the emitter assembly. For example, the emitter assembly may be electrically connected to a high-voltage power source by a connector 1320 via a conductive member 1310. In other implementations, one or more optical fibers may be connected to a light source (e.g., a laser) to provide power for generating the shock waves. In some embodiments, translation of the proximal Y-arm 1300 a distance d along the inner shaft 1010 correlates with the longitudinal direction (distal-proximal direction) of the emitter assembly by a distance d.

[0100] The inner shaft 1010 extends to a proximal region of the handle 1000. In one or more embodiments, the handle 1000 includes a stabilization structure 1200 including a bar 1202 extending from the distal region of the handle 1000 to the proximal region. In some embodiments, the bar 1202 may be connected at its distal end to the distal Y-arm 1100. In one or more embodiments, the bar 1202 has a length that is approximately the same length as the working length of the balloon. The proximal Y-arm 1300 can slidably translate along the inner shaft 1010 between the proximal region of the handle and the distal Y-arm 1100. When the proximal Y-arm 1300 is in its proximal-most position on the inner shaft 1010, the emitter assembly can be fully retracted within the outer shaft 1500. Distal translation of the proximal Y-arm 1300 moves the emitter assembly distally within the balloon toward the distal end of the balloon.

[0101] In one or more embodiments, the proximal handle 1000 includes a connector 1340 in the proximal Y-arm. The connector 1340 may include a luer fitting. In one or more embodiments, the connectors 1104 and 1340 include silicone seals and / or flexible valves to ensure a fluid seal and help maintain the internal pressure of the balloon. In some embodiments, the connectors 1104 and 1340 each include an O-ring to ensure a fluid seal. These connectors also help facilitate movement of the movable emitter carrier. Advantageously, the silicone or silicone-type seals in these connectors may be self-sealing, and their use ensures a simple structure and mechanism for creating a fluid seal.

[0102] The proximal handle 1000, in one or more embodiments, includes markings located on the inner shaft 1010 or along the stabilizing bar 1202 to indicate to the user the position of the movable emitter assembly. For example, positioning the proximal Y-arm 1300 at proximal marking 1011 may correlate with the emitter assembly being retrieved from the balloon. Positioning the proximal Y-arm 1300 at distal marking 1012 may correlate with the emitter assembly being in the distal region of the balloon.

[0103] 4B shows another exemplary proximal handle 200 for a shockwave catheter, according to some embodiments of the present disclosure. The handle 200 includes a first fluid port 210, a second fluid port 220, and a third fluid port 230, each fluidly connected to a fillable enclosure by a separate fluid lumen. One or both of the first port 210 and the second port 220 can be used to remove air and prime the catheter for use in shockwave therapy.

[0104] FIG. 5A shows an exemplary proximal section 510 of a movable emitter carrier, and FIG. 5B shows an exemplary distal section 520 of the movable emitter carrier, according to some embodiments. The proximal section 510 includes multiple conductor lumens through which conductors (e.g., wires) extend from a power source. Having a cylindrical shaft with conductor lumens helps provide a seal through a connector at the proximal handle (e.g., a Luer fitting) described above. The distal section 520 includes multiple grooves that accept the same conductors. The grooves in the distal section 520 of the emitter shaft can help achieve a narrower profile at the distal end. In one or more embodiments, two dissimilar shafts are joined (e.g., thermally joined) to each other to form a movable emitter carrier with one or more conductor lumens in the proximal region and one or more conductor grooves in the distal region.

[0105] In one or more embodiments, the IVL catheter with a steerable emitter has a diameter of 8 French or less than 8 French gauge, hi some embodiments, the IVL catheter with a steerable emitter has a diameter of 5 French or less than 5 French gauge.

[0106] In some embodiments of the present invention, an IVL catheter includes an emitter centering feature that includes one or more shockwave emitter centering structures. Figures 6A-6C show a catheter 3000 having centering structures 3002, 3004, 3006, 3008, and 3010 adjacent to a shockwave emitter assembly including shockwave emitters 3012, 3014, 3016, and 3018. Figure 6A shows the centering structures in a radially compressed state. Figures 6B and 6C show the centering structures in a radially expanded state, and Figure 6C shows the catheter 3000 without an enclosure for clarity. The centering structures 3002, 3004, 3006, 3008, and 3010 are in a radially compressed state when the emitter assembly of emitters 3012, 3014, 3016, and 3018 is encased inside the outer shaft 3100. The centering structures 3002, 3004, 3006, 3008, 3010 are in a radially expanded state when the emitter assembly is advanced from the outer shaft 3100 into the enclosure 3200. The centering structures 3002, 3004, 3006, 3008, 3010 may self-expand radially when released from the packaging. Upon expansion, the centering structures 3002, 3004, 3006, 3008, 3010 contact the inner surface of the enclosure, spacing the emitters 3012, 3014, 3016, 3018 from the inner surface of the enclosure 3200. In some embodiments, when radially expanded, the centering structures 3002, 3004, 3006, 3008, 3010 space each of the emitters 3012, 3014, 3016, 3018 a distance of at least 0.1 mm from the inner surface of the enclosure 3200. In some embodiments, the centering structures space one or more emitters a distance of at least 0.5 mm from the inner surface of the enclosure. In some embodiments, the centering structures space one or more emitters a distance of at least 2 mm from the inner surface of the enclosure. In some embodiments, the distance required to space one or more shockwave emitters from the inner surface of the enclosure may depend on the material properties (e.g., pyrolysis properties) of the enclosure and / or the energy output of the emitters.

[0107] In some embodiments, the IVL catheter includes multiple shockwave emitters and multiple emitter centering structures. The number of emitter centering structures may be one more than the number of shockwave emitters. The emitter centering structure may be positioned proximally relative to the most proximal emitter. The emitter centering structure may be positioned distally relative to the most distal emitter.

[0108] During delivery through a body cavity, the centering structure may be encased inside the outer shaft 3100 in a radially compressed state. When the enclosure 3200 is adjacent to the lesion to be treated, the enclosure can be expanded. The emitter and centering structure can then be moved inside the enclosure. Upon introduction into the wider diameter enclosure, the centering structure can self-expand until it contacts the inner surface of the enclosure. Centering the emitter, and thus isolating the enclosure from the intense heat associated with shock wave generation, can be important to maintaining the integrity of the enclosure (e.g., angioplasty balloon).

[0109] 6D and 6E illustrate only an exemplary centering structure 3001 according to one or more embodiments. FIG. 6D illustrates the centering structure 3001 in a radially compressed state. FIG. 6E illustrates the centering structure 3001 in a radially expanded state. The centering structure 3001 includes a first end 3020 and a second end 3022. Each of the ends may include a band (e.g., an annular band, a discontinuous band, or another type of band). The first end 3020 and the second end 3022 may be connected by a self-expanding region 3030. The self-expanding region 3030 may include beams 3032, 3034, 3036, and 3038. The beams 3032, 3034, 3036, and 3038 may be flexible beams. The beams 3032, 3034, 3036, 3038 can be made of a material that can be radially compressed (i.e., straightened) and then recovered to a radially expanded state. In some embodiments, the beams are made of nitinol, another nickel alloy, or another elastic material. The beams can have widths of 20 to 250 micrometers (μm). While centering structure 3001 is shown with four beams, other numbers of beams are possible, such as two, three, five, six, or more beams. When radially expanded, the centering structure can have a maximum diameter at least 0.5 mm larger than when radially compressed. In some examples, the maximum diameter of the centering structure in its radially expanded state is at least 0.75 mm larger than when radially compressed.

[0110] One or both of the first end 3020 and second end 3022 may be fixedly attached to the movable emitter shaft. By having at least one free end, the centering structure 3001 is free to expand within the enclosure or compress when encased within an external shaft.

[0111] 7 illustrates an IVL catheter 4000 having an emitter centering feature including one or more centering structures 4002, 4004, 4006, 4008, and 4010 according to one or more embodiments. Each of the centering structures 4002, 4004, 4006, 4008, and 4010 includes an inflatable enclosure (e.g., a balloon) fluidly connected to a proximal fluid port by a fluid lumen. Similar to the centering structures shown in FIGS. 6A-6E, the centering structures 4002, 4004, 4006, 4008, and 4010 function to space the shock wave emitter from the enclosure. The inflatable enclosures of these centering structures can be fabricated from semi-compliant or non-compliant materials.

[0112] In one or more embodiments, the centering feature may include one or more radially expandable porous (e.g., fibrous and / or polymeric) structures positioned adjacent to and / or between the shock wave emitters. Each porous structure may be configured to exert a sufficient radial force when in a radially expanded state and positioned inside a relatively compliant enclosure (e.g., a semi-compliant or compliant angioplasty balloon), and to be in a radially collapsed state when positioned inside a relatively non-compliant shaft or tubing.

[0113] It should be noted that the elements and features of the example catheters shown herein may be rearranged, recombined, and modified without departing from the invention. For example, while the figures show example electrode assemblies, the present disclosure is intended to include catheters having a variety of electrode configurations, and the number, placement, and spacing of emitters and electrode pairs may be modified without departing from the subject invention.

[0114] While the electrode assemblies and catheter devices described herein have been primarily discussed in the context of treating occlusions and lesions in the coronary vasculature, the electrode assemblies and catheters herein can be used for various occlusions and peripheral vasculature (e.g., above the knee, below the knee, iliac, carotid, etc.), and other anatomical structures can be treated using IVL. Further, for example, practice of the embodiments disclosed herein can be used to treat soft tissue, such as cancer and tumors (i.e., non-thermal ablation procedures), thrombus, fibroids, cysts, organs, scars, and fibrous tissue removal, polymorphous tissue, or other tissue destruction and removal. The electrode assembly and catheter designs can also be used for nerve stimulation procedures, targeted drug delivery, treatment of tumors within body cavities (e.g., tumors within blood vessels, the esophagus, the intestine, the stomach, or the vagina), wound treatment, non-surgical removal and destruction of tissue, and as an alternative to thermal procedures or cauterization for venous insufficiency and fallopian ligation (i.e., for permanent female contraception).

[0115] In one or more examples, the electrode assemblies and catheters described herein can also be used in tissue engineering methods, such as mechanical tissue decellularization to generate bioactive scaffolds in which new cells (e.g., exogenous or endogenous cells) can replace old cells; introducing porosity into a site to improve cell retention, cell infiltration / migration, and the diffusion of nutrients and signaling molecules to promote angiogenesis, cell proliferation, and tissue regeneration, as well as cell replacement therapy. Such tissue engineering methods can be useful for treating ischemic heart disease, fibrotic liver, fibrotic intestine, and traumatic spinal cord injury (SCI). For example, for the treatment of spinal cord injury, the devices and assemblies described herein can facilitate the removal of scarred spinal cord tissue, which acts as a barrier to neuronal reconnection, prior to the injection of a lentivirus-loaded anti-inflammatory hydrogel to genetically engineer spinal cord neurons to regenerate.

[0116] As provided herein, any disclosure of a numerical range describing a dimension or measurement, such as thickness, length, weight, time, frequency, temperature, voltage, current, angle, etc., should be understood to include any numerical increment or gradient within the stated range for the given dimension or measurement.

[0117] Additionally, while the emitters disclosed in the examples herein typically have a structure having two electrode pairs on each emitter, it is contemplated that emitters having three electrode pairs (e.g., 120 degrees circumferentially spaced from each other), four electrode pairs (e.g., 90 degrees circumferentially spaced from each other), five electrode pairs (e.g., 72 degrees circumferentially spaced from each other), six electrode pairs (e.g., 60 degrees circumferentially spaced from each other), etc. There may be physical limitations on the design of emitter assemblies with respect to wiring size and arrangement, ability to deliver sufficient power, electrode erosion profile, etc. It is within the scope of this disclosure that such emitters may be successfully developed with improved manufacturing capabilities.

[0118] Additionally, numerical designators such as "first," "second," "third," "fourth," etc. are merely descriptive and do not necessarily indicate the relative order, location, or identity of the elements or features described by the designators. For example, a "first" shockwave may be immediately followed by a "third" shockwave, which in turn is followed by a "second" shockwave. As another example, a "third" emitter may be used to generate a "first" shockwave, and vice versa. Thus, the numerical designators of various elements and features are not intended to limit the present disclosure and may be modified and interchanged without departing from the invention.

[0119] The foregoing is merely illustrative of the principles of the present invention, and it will be understood that various modifications, variations, and combinations can be made by those skilled in the art without departing from the scope and spirit of the invention. Any of the various catheter variations disclosed herein may include features described with any other catheter or catheter combination herein. Furthermore, any method may be used with any of the disclosed catheters. Accordingly, the present invention is not intended to be limited except as by the appended claims.

Claims

1. 1. A catheter for treating an obstruction in a body cavity, the catheter comprising: an outer elongate member containing a fluid lumen; a flexible enclosure secured to a distal region of the outer elongate member, the flexible enclosure being fillable with a conductive fluid via the fluid lumen; an inner elongate member positioned within the outer elongate member and extending through the flexible enclosure to a distal region of the flexible enclosure; a movable emitter member having an emitter assembly mounted on the movable emitter member and connected to a power source, the movable emitter member being disposed between the inner elongate member and the outer elongate member and being longitudinally movable between the inner elongate member and the outer elongate member; A catheter comprising:

2. 2. The catheter of claim 1, wherein in a first configuration of the movable emitter member, the emitter assembly is at a first location, and in a second configuration of the movable emitter member, the emitter assembly is at a second location distal to the first location.

3. The catheter of claim 2 , wherein the emitter assembly is disposed proximal to the flexible enclosure in the first configuration, and the emitter assembly is disposed within the flexible enclosure in the second configuration.

4. the flexible enclosure has a working length l; the emitter assembly comprises a plurality of shockwave emitters; 3. The catheter of claim 2, wherein the distance between the most proximal and most distal shockwave emitters is less than or equal to 0.5l.

5. 10. The catheter of claim 1, further comprising a proximal hub, wherein the outer elongate member, the inner elongate member, and the movable emitter member extend to the proximal hub, and wherein translation of the movable emitter member along the inner elongate member at the proximal hub moves the emitter assembly.

6. The catheter of claim 5 , wherein translation of the movable member at the proximal hub a distance d moves the emitter assembly in the longitudinal direction the distance d.

7. The catheter of claim 5 , wherein the proximal hub includes a distal end opening that is fluid-sealed to the proximal end of the outer elongate member.

8. The catheter of claim 5 , wherein the inner elongate member includes indicia correlating to the longitudinal position of the emitter assembly within the flexible enclosure.

9. the proximal hub includes a distal diaphragm seal and a proximal diaphragm seal; the inner elongate member and the movable emitter member each extend through the distal diaphragm seal; The catheter of claim 5 , wherein the inner elongate member extends through the proximal diaphragm seal.

10. 6. The catheter of claim 5, wherein the proximal hub comprises a position stabilizer having a first anchor at a first location on the proximal hub and a second anchor at a second location on the proximal hub, the second location being more proximal than the first location, and the movable emitter member includes a proximal end that is translatable between the first anchor and the second anchor.

11. The catheter of claim 1 , wherein at least one of the inner elongate member and the movable emitter member comprises polytetrafluoroethylene.

12. 10. The catheter of claim 1, wherein the inner elongate member has an outer diameter d1, and the movable emitter member includes a lumen having a diameter d2 that is at least 0.002 inches greater than d1.

13. The emitter assembly includes an emitter centering member, the emitter centering member comprising: The proximal band and a distal band; a plurality of flexible beams connecting the proximal band to the distal band, each beam having a central region extending radially outward; The catheter of claim 1 , comprising:

14. 14. The catheter of claim 13, wherein the flexible enclosure includes an inflated state and a deflated state, and when the flexible enclosure is in the inflated state, the central region extends further radially outward than when the flexible enclosure is in the deflated state.

15. 14. The catheter of claim 13, wherein the emitter assembly comprises one or more shock wave emitters, and the central region of the multiple beams spaces the one or more shock wave emitters from a wall of the flexible enclosure.

16. The catheter of claim 13 , wherein the emitter centering member comprises one or more of a polymer and a metal.

17. The catheter of claim 1 , wherein the flexible enclosure comprises an angioplasty balloon having a working length l of at least 50 mm.

18. 1. A method of performing intravascular lithotripsy, said method comprising: Introducing a catheter into a body cavity, said catheter comprising: an elongate member extending from the proximal end of the catheter to the distal end of the catheter; a movable emitter member movable along the elongate member and including a shockwave emitter assembly; an expandable flexible enclosure secured to a distal region of the elongate member; and advancing the catheter through the body cavity until the flexible enclosure is adjacent an occlusion in the body cavity; inflating the flexible enclosure with fluid via a fluid lumen of the catheter; moving the emitter member along the elongate member; providing power to the shockwave emitter assembly to generate one or more shockwaves; A method comprising:

19. 20. The method of claim 18, wherein moving the emitter member comprises moving the emitter member such that the shockwave emitter assembly moves between a first location proximal to the flexible enclosure and a second location within the flexible enclosure.

20. 20. The method of claim 18, wherein moving the emitter member comprises moving the emitter member such that the shockwave emitter assembly moves between a first location within the flexible enclosure and a second location within the flexible enclosure.

21. 20. The method of claim 18, further comprising imaging the body cavity with at least one of x-ray fluoroscopy, optical coherence tomography, and intravascular ultrasound.

22. The method of claim 18 , wherein moving the emitter member comprises moving a proximal end of the emitter member.

23. 20. The method of claim 18, further comprising correlating movement of the emitter assembly with movement of the emitter member at a proximal end thereof by using indicia located along a proximal region of the elongate member.

24. 1. An emitter centering member for an IVL catheter, the emitter centering member comprising: The proximal band and a distal band longitudinally spaced from the proximal band; a plurality of flexible beams connecting the proximal band to the distal band, each flexible beam including a central region that compressibly extends laterally outward; An emitter centering member comprising:

25. 1. A handle for an IVL device, said handle comprising: a proximal end; an elongate member extending from the proximal end; a movable arm movably disposed on the elongate member and including a proximal diaphragm seal and a power port; a distal arm disposed distally of the movable arm and including a distal diaphragm seal and a fluid port; a stabilizing bar extending from the proximal end to the distal arm; and A handle.

26. 26. The handle of claim 25, wherein the movable arm includes a second fluid port.

27. 27. The handle of claim 26, wherein the movable arm includes a third fluid port.

28. 1. A catheter for treating an obstruction in a body cavity, the catheter comprising: an elongate member including a fluid lumen; a flexible enclosure secured to a distal region of the elongate member, the flexible enclosure being fillable with a conductive fluid via the fluid lumen and having a working length l; a movable emitter member having an emitter assembly mounted on the movable emitter member and connected to a power source, the emitter assembly comprising a plurality of emitters; Equipped with A catheter wherein the distance from the most proximal emitter to the most distal emitter is less than or equal to 1 / 2, and wherein the movable emitter member is longitudinally translatable within the flexible enclosure.

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