Lithotripsy catheters with skived hypotubes

Abstract

An IVL catheter comprises (i) a catheter shaft comprising a hypotube comprising a proximal section and a distal section, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, the hypotube comprising an electrically conductive material, the hypotube being operatively connectable to a first terminal of an electrical pulse generator; (ii) one or more emitters connected to the catheter shaft, the one or more emitters being operatively connectable to one or more second terminals of the electrical pulse generator, the one or more emitters being configured for generating pressure waves; and (iii) an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein the skived portion extends into the interior of the enclosure member such that the radially discontinuous hypotube wall is in electrical communication with the one or more emitters.

Description

LITHOTRIPSY CATHETERS WITH SKIVED HYPOTUBESInventors: Benjamin D. Haselman, Jonathan P. Durcan, Brad J. Martinsen, Puneet Kamal Singh Gill, Kathy A. Kaveney, Stephanie A. MaldonadoCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of (i) U.S. Provisional Patent Application No. 63 / 737,580, filed on December 20, 2024, and entitled “INTRAVASCULAR LITHOTRIPSY CATHETER HAVING ENHANCED CATHETER SHAFT”, and (ii) U.S. Provisional Patent Application No. 63 / 846,759, filed on July 18, 2025, and entitled “LITHOTRIPSY CATHETERS WITH SKIVED HYPOTUBES”; the entirety of each of the foregoing applications is incorporated herein by reference for all purposes.BACKGROUND OF THE INVENTIONTechnical Field

[0002] The present disclosure pertains generally to the field of intravascular and other medical devices for insertion into the vasculature or other bodily vessels, and more particularly to such devices that include an enclosure member (e.g., a balloon or other expandable member) for use in lithotripsy procedures within such vessels. Intravascular lithotripsy (IVL) is an example of such, although additional examples include use of a lithotripsy balloon catheter within a heart valve vessel lumen or heart valve leaflet vessel lumen. While IVL may be referred to in various examples discussed herein, it will be appreciated that the present devices and methods extend to other such uses.Description of the Related Art

[0003] Calcification of the vasculature and other vessels refers to the accumulation of calcium deposits on or within the walls of such vessels, which can significantly reduce blood flow and increase the risk of cardiovascular events like heart attacks and strokes, as well as conditions such as chronic kidney disease and diabetes. As such, it is a serious medical concern. Additionally, vascular calcification reduces arterial compliance and complicates both short- and long-term clinical outcomes following revascularization treatments. Coronary artery calcification is reported in 18% to 31% of percutaneous procedures, while the incidence in peripheral arterial procedures is 30% to 50%.

[0004] Coronary artery calcification negatively impacts the outcomes of coronary interventions by hindering device passage, as well as stent placement and expansion, and by causing delamination of drug-eluting polymers, which disrupts drug delivery andDocket No. 23812.33.1a 1elution. Likewise, peripheral artery calcification limits vessel expansion, leading to greater residual stenosis, which decreases the effectiveness of procedures and may weaken the antiproliferative effect of drug-coated balloons.

[0005] Methods for treating coronary artery calcification, such as use of noncompliant, cutting, and scoring balloons, as well as atherectomy (e.g., atheroablative) technologies, have their own limitations. High-pressure balloon dilation with noncompliant or specialty balloons may not provide enough force to fracture calcium and expand the vessel, potentially causing barotrauma-related dissection or perforation. Laser atherectomy can be unpredictable, while rotational or orbital atherectomy may create eccentric ‘rut or trough’ formations with little effect on the overall calcium circumference. Peri -procedural complications, including slow flow, myocardial infarction, flow-limiting dissection, distal embolization, and perforation, are more common when atheroablative technologies are used in conjunction with balloons, compared to using balloons alone.

[0006] Likewise with peripheral artery calcification, endovascular treatment with percutaneous transluminal angioplasty or stenting is associated with higher rates of dissection, perforation, and distal embolization, along with lower long-term patency when peripheral artery calcification is present. While atherectomy has been shown to enhance luminal diameter and reduce the need for emergency stenting, vascular complications, including distal atheroembolization, persist as significant challenges.

[0007] Intravascular lithotripsy (IVL) has emerged as a treatment for vascular calcification. In IVL, the shaft of a balloon angioplasty catheter contains lithotripsy emitters (which generate acoustic pressure waves), allowing localized wave pulses to be delivered circumferentially for the disruption of vascular calcium. In this way, IVL converts electrical energy into mechanical energy by creating sonic pressure waves (e.g., generated by vaporizing the fluid within the balloon) that selectively disrupts calcium deposits. The sonic pressure waves created may exert up to approximately 55 atm of localized pressure on the calcification or lesion, thereby breaking both superficial and deep calcium deposits within the vessel wall. In this way, IVL procedures increase vessel compliance by creating microfractures in the calcified plaque. Vessel compliance is important for adequate balloon and stent expansion, in addition to general coronary and vascular health. Importantly, the sonic pressure waves can selectively disrupt calcified plaques, while causing no significant harm to non-calcified, soft tissue. In contrast to calcified tissue, sonic pressure waves have a high transmission through (rather than reflection from) non-calcified tissue because there are minimal differences in acousticDocket No. 23812.33.1a 2impedance between the medium carrying the sonic waves and the soft tissue, which is composed primarily of water.

[0008] The subject matter claimed herein is not limited to embodiments that solve any challenges or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area where at least some embodiments described herein may be practiced.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:

[0010] Figure 1 illustrates an example general system for providing intravascular or other lithotripsy within a body lumen.

[0011] Figure 2 illustrates an inflated balloon in a vessel for providing lithotripsy within such vessel.

[0012] Figure 3 illustrates a side sectional view of a distal portion of an IVL catheter, in accordance with implementations of the disclosed subject matter.

[0013] Figure 4 illustrates a perspective view of a skived portion of a hypotube of an IVL catheter, in accordance with implementations of the disclosed subject matter.

[0014] Figure 5 illustrates a top view of part of a skived portion of a hypotube of an IVL catheter, in accordance with implementations of the disclosed subject matter.

[0015] Figure 6 illustrates an axial cross-sectional view of an example IVL catheter, in accordance with implementations of the disclosed subject matter.

[0016] Figure 7 illustrates an axial cross-sectional view of another example IVL catheter, in accordance with implementations of the disclosed subject matter.

[0017] Figures 8 and 9 illustrate diagrams depicting example electrical connections among components of an IVL system, in accordance with implementations of the disclosed subject matter.

[0018] Figure 10 illustrates an axial cross-sectional view of another example IVL catheter, in accordance with implementations of the disclosed subject matter.Docket No. 23812.33.1a 3

[0019] Figure 11 illustrates a diagrammatic cross-section of a vessel showing example activation of an intravascular lithotripsy catheter adjacent to a calcified lesion, in accordance with implementations of the disclosed subject matter.

[0020] Figure 12 illustrates a perspective view of an intravascular lithotripsy system, in accordance with implementations of the disclosed subject matter.

[0021] Figure 13 illustrates a side view of an over-the-wire intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0022] Figure 14 illustrates a side view of a rapid-exchange intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0023] Figure 15 illustrates a side view of a control handle of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0024] Figure 16 illustrates a cutaway perspective view of a distal portion of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0025] Figure 17 illustrates a sectional view of a catheter shaft of an intravascular lithotripsy catheter taken along section line 17-17 of Figure 16, in accordance with implementations of the disclosed subject matter.

[0026] Figure 18A illustrates a sectional view of a distal portion of an intravascular lithotripsy catheter taken along section line 18A-18A of Figure 14, in accordance with implementations of the disclosed subject matter.

[0027] Figure 18B illustrates a section view of a distal portion of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0028] Figure 19 illustrates a perspective view of a skived portion of a hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0029] Figure 20 illustrates a sectional view of a skived portion of a hypotube of an intravascular lithotripsy catheter taken along section line 20-20 of Figure 19, in accordance with implementations of the disclosed subject matter.

[0030] Figure 21 illustrates a perspective view of another skived portion of a hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0031] Figure 22 illustrates a perspective view of another skived portion of a hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.Docket No. 23812.33.1a 4

[0032] Figure 23 illustrates a perspective view of a corrugated hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0033] Figure 24 illustrates an end view of a corrugated hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0034] Figure 25 illustrates a perspective view of a multi-filar hypotube of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0035] Figure 26 illustrates sectional view of a sectional view of a hypotube of an intravascular lithotripsy catheter taken along section line 26-26 of Figure 18 A, in accordance with implementations of the disclosed subject matter.

[0036] Figure 27 is sectional view of a sectional view of a hypotube of an intravascular lithotripsy catheter taken along section line 27-27 of Figure 18 A, in accordance with implementations of the disclosed subject matter.

[0037] Figure 28A illustrates an end view of a tube extender having a D-shaped profile of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0038] Figure 28B illustrates an end view of a tube extender having a crescent-shaped profile of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0039] Figure 28C illustrates an end view of a tube extender having a pie-shaped profile of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0040] Figure 28D illustrates an end view of a tube extender having an ellipticalshaped profile of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0041] Figure 28E illustrates an end view of a tube extender having a triangular-shaped profile of an intravascular lithotripsy catheter, in accordance with implementations of the disclosed subject matter.

[0042] Figure 29 illustrates a perspective view of a catheter shaft of an intravascular lithotripsy catheter including a stiffener, in accordance with implementations of the disclosed subject matter.Docket No. 23812.33.1a 5

[0043] Figure 30 illustrates a flow diagram depicting an example method of performing intravascular lithotripsy, in accordance with implementations of the disclosed subject matter.DETAILED DESCRIPTIONI. Introduction

[0044] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, some features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual embodiment, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. It should further be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0045] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference, and as if each said individual publication or patent application was fully set forth, including any figures, herein.

[0046] One or more embodiments of the present disclosure may generally relate to a balloon catheter including a multilayer balloon for use in a lithotripsy procedure.II. Example Methods and Devices

[0047] The systems, assemblies, and / or components of the present disclosure may be configured for use in intravascular lithotripsy (IVL) procedures (e.g., within the coronary vasculature, or the peripheral vasculature), as well as other lithotripsy procedures, including but not limited to heart valve lithotripsy procedures and / or heart valve leaflet lithotripsy procedures. The presently disclosed lithotripsy devices and / or components may be suitable for broad application within a wide variety of lithotripsy procedures.

[0048] Figures 1 and 2 illustrate example components of a lithotripsy device 100. A lithotripsy device 100 may comprise a power source 102 (in the form of an electrical pulse generator, but alternatively in the form of a laser or other system), a handle 104 with therapy delivery control 106, a catheter 110 with one or more lithotripsy emitters 112 (shown in the form of a pair of arcing electrodes, but alternatively they could compriseDocket No. 23812.33.1a 6laser or other optical emitters configured to generate an acoustic shock wave), optional marker bands 114, and an enclosure member 120. The enclosure member 120 may comprise an at least partially flexible material and may enclose a fluid-fillable space. Fluid may be selectively injected into and withdrawn from the fluid-fillable space, enabling the enclosure member 120 to achieve extended (or inflated) and retracted (or deflated) states.

[0049] In the example shown in Figures 1 and 2, the catheter 110 defines a guidewire lumen 122 through which a guidewire 130 passes for delivering the enclosure member 120 at the desired location along the guidewire 130. In some implementations, a sheath 124 may surround at least part of the guidewire lumen 122 and define a delivery lumen 126 through which saline or other inflation fluid can be controllably delivered for inflation of the enclosure member 120. The delivery lumen 126 may provide a concentric space around at least part of the guidewire lumen 122. Wires, cables, or other elongated components (not shown) may extend through the delivery lumen 126 from the handle 104 and / or power source 102 to the lithotripsy emitters 112 and / or other components. The catheter 110 may be connected at a proximal end to a hub connector 140 that can include any number of ports, which may be utilized as entry or exit paths for the guidewire 130, wires / cables, inflation fluid, and / or other components / materials to enter or exit the catheter 110.

[0050] Figure 2 shows the enclosure member 120 inflated to a therapy delivery state where the lithotripsy emitters 112 may be “fired” to disrupt the calcium deposits within or on the vessel wall. Optional marker bands 114 may be helpful in visualization and proper positioning of the lithotripsy emitters 112 relative to the calcified tissue to be treated, using known imaging techniques for such positioning. The enclosure member 120 may be inflated to a typical lithotripsy pressure (e.g. 4 to 6 atm) for therapy to be delivered (e.g., via operation of the therapy delivery control 106 to trigger pressure wave generation by the lithotripsy emitters 112). Transmission of the wave through the enclosure member 120 and toward the vessel wall may deliver at least one of compressive, shearing, spallation, squeezing or cavitation forces on the vessel wall, so as to disrupt the calcified tissue. Such forces may be due to the pressure wave (e.g., distinct from forces exerted on the tissue by the extended enclosure member 120).

[0051] Deliverability of IVL devices is associated with various challenges. The design and structure of IVL devices often include wires or other elongated components that connect proximal components, such as electrical pulse generators, to distal emitters responsible for pressure wave generation. These wires contribute to an increased crossingDocket No. 23812.33.1a 7profile for IVL devices, which can impact the deliverability of the device through narrow or tortuous vascular pathways.

[0052] Many IVL catheters include a hypotube that provides structural rigidity and / or support to enable precise navigation of the catheter through patient vasculature. The hypotube can additionally serve as a conduit for fluid (e.g., to facilitate balloon inflation / deflation), wires or elongated components, guidewires (or guidewire lumens), etc.

[0053] The disclosed subject matter includes one or more embodiments in which the hypotube of an IVL catheter is formed from electrically conductive material, allowing the hypotube to be used to facilitate electrical communication between proximal components, such as electrical pulse generators, and distal emitters for generating pressure waves. According to the present disclosure, a hypotube may comprise electrically conductive material and may include a skived portion with a radially discontinuous hypotube wall. The skived portion may extend into an enclosure member (e.g., a balloon) and into electrical communication with one or more emitters housed by the enclosure member. Such a configuration may allow the hypotube to serve as a common electrical path (e.g., a common ground or return path) for all emitters disposed within the enclosure member. By leveraging the hypotube as an electrical path, the design of an IVL catheter may advantageously omit one or more wires or other elongated electrical components, which may contribute to a reduced crossing profile and may improve device deliverability.

[0054] In one or more implementations, the hypotube may serve as an electrode for one or more emitters disposed within a distal enclosure member of an IVL catheter. For instance, the IVL catheter may comprise one or more wires or otherwise electrodes disposed within a distal enclosure member. The skived portion of the hypotube may extend into the enclosure member to be arranged spaced apart from the electrode(s) within the enclosure member, allowing one or more spark gaps to be formed between the skived portion and the electrode(s). Such features may enable omission of various emitter structures used in conventional IVL catheters, such as ring-like electrode components circumferentially positioned about an inner member of the catheter shaft within the balloon. The omission of such structures may contribute to a reduced crossing profile and may improve device deliverability.

[0055] In one or more embodiments, the skived portion of a hypotube, as disclosed herein, may comprise one or more blocking features that are configured to axially align with the emitter(s) of an IVL catheter within a distal enclosure member (e.g., balloon). TheDocket No. 23812.33.1a 8blocking feature(s) may be positioned to circumferentially extend about the emitter(s), allowing the blocking feature(s) to modify propagation characteristics of pressure waves generated via the emitter(s) (e.g., by at least partially blocking pressure waves from propagating through the blocking feature(s)). In some instances, the blocking feature(s) may be shaped to at least partially reflect generated pressure waves, which can modify therapeutic output at regions diametrically opposite the blocking feature(s) (e.g., relative to the emitter(s)). Such features may enhance the versatility of IVL therapy be enabling practitioners to utilize additional treatment approaches, such as selectively focusing or blocking the application of therapy on specific radial sections of the vessel wall, which may improve treatment precision and / or effectiveness.

[0056] Having just described some high-level features and benefits related to the disclosed embodiments, attention will now be directed to the Figures, which illustrate various conceptual representations, architectures, methods, and / or supporting illustrations related to the disclosed embodiments.

[0057] Figure 3 illustrates a side sectional view of a distal portion of an IVL catheter 300. The IVL catheter 300 may correspond generally to the catheter 110 described hereinabove with reference to Figures 1 and 2. For instance, the IVL catheter 300 shown in Figure 3 includes a catheter shaft 302 that is adapted for navigation through the vasculature of a subject. The catheter shaft 302 can comprise a unitary construction or can include multiple components that are bonded, nested, co-extruded, or otherwise assembled, such as inner / outer members / shafts, lumen tubes, reinforcing components (e.g., braiding or coiling layers), hypotubes, joints, metal segments, etc.

[0058] In the example shown in Figure 3, the catheter shaft 302 includes an inner shaft 304 (or inner member) and an outer shaft 306 (or outer member), each of which may comprise any number of constituent components. The inner shaft 304 may define a guidewire lumen for a guidewire 308 (e.g., similar to guidewire lumen 122 for guidewire 130 described above), and the outer shaft 306 may at least partially surround the inner shaft 304 to form a generally annular space or channel therebetween. This annular space or channel may comprise at least part of a fluid lumen 310 of the catheter shaft 302, which may be used as an inflation and deflation lumen for an enclosure member 320 of the IVL catheter 300. The fluid lumen 310 may be formed by additional spaces defined by the catheter shaft 302 (e.g., by part of the outer shaft 306 that does not axially overlap with the inner shaft 304). The fluid lumen 310 may additionally or alternatively operate as a conduit for wires or other elongated components to facilitate communication between one or moreDocket No. 23812.33.1a 9emitters 314 of the IVL catheter 300 and one or more proximal components (e.g., power sources, electrical pulse generators, handles, therapy delivery controls, etc.). Similar to the catheter 110 described above, the IVL catheter 300 may comprise one or more marker bands 316.

[0059] In the example shown in Figure 3, the emitters 314 comprise electrical arcingbased emitters, which can be configured to generate localized acoustic pressure waves to fracture calcified lesions within vessels. The emitters 314 may operate by discharging high-voltage electrical pulses across gaps between electrodes (e.g., gaps formed between exposed portions of wires and exposed portions of metal bodies) surrounded by fluid within the enclosure member 320. The electrical pulses can cause plasma arcs that vaporize surrounding fluid, creating rapidly expanding and collapsing cavitation bubbles and corresponding pressure waves that propagate through the surrounding fluid, through the enclosure member 320, and into the lesion / vessel wall. The pressure wave may disrupt hardened calcium with only minor impact to soft, healthy tissue.

[0060] Although one or more examples provided herein may focus, in at least some respects, on electrical arcing-based emitters for IVL systems, other types of emitters may be implemented within the scope of the present disclosure, such as laser-based emitters and / or others.

[0061] As indicated above, the IVL catheter 300 may include an enclosure member 320, which may be connected to the catheter shaft 302. For instance, a proximal region 322 of the enclosure member 320 may be bonded or otherwise connected to the outer shaft 306 of the catheter shaft 302, whereas a distal region 324 of the enclosure member 320 may be bonded or otherwise connected to the inner shaft 304. As illustrated in Figure 3, the emitters 314 may be disposed within the enclosure member 320, and the interior of the enclosure member 320 may be in fluid communication with the fluid lumen 310 (e.g., defined by the inner shaft 304 and the outer shaft 306) to facilitate inflation and deflation of the enclosure member 320. Figure 3 illustrates the enclosure member 320 in an inflated or extended state.

[0062] Figure 3 illustrates the IVL catheter 300 comprises a rapid exchange (RX) guidewire configuration, where the IVL catheter 300 includes a rapid exchange port, or RX port 326, positioned between proximal and distal ends of the IVL catheter 300. The RX port 326 may serve as an exit / entry port for the guidewire 308, allowing the hub connector (e.g., hub connector 140) connected to the IVL catheter 300 to omit an exit port for the guidewire 308. For instance, the RX port 326 may be defined by a hole or openingDocket No. 23812.33.1a 10in an outer surface of the catheter shaft 302 that allows the guidewire 308 to transition from locations external to the catheter shaft 302 to locations internal to the catheter shaft 302. In some implementations, the guidewire 308 may enter the IVL catheter 300 through an opening at the distal dip of the IVL catheter 300 and exit through the RX port 326. The RX port 326 may enable quick and efficient exchange of the guidewire 308, which may facilitate precise navigation and positioning of the IVL catheter 300 within patient vasculature.

[0063] In contrast with an RX guidewire configuration, under an over-the-wire (OTW) guidewire configuration, the IVL catheter may omit an RX port and may instead include a guidewire exit port on the hub connector, allowing the guidewire to enter the IVL catheter through the distal tip of the IVL catheter and exit through the guidewire exit port on the hub connector. One will appreciate, in view of the present disclosure, that one or more principles disclosed herein may be applied to catheters with RX guidewire configurations, OTW guidewire configurations, or other guidewire configurations.

[0064] In the example shown in Figure 3, the catheter shaft 302 may comprise a hypotube 330 that includes a proximal section 332 and a distal section 334. The hypotube 330 may be formed from a substantially tubular hypotube wall and may comprise a monolithic or unitary construction. The proximal section 332 of the hypotube 330 may define a fluid lumen (see fluid lumen 402, Figure 4) that may extend proximally into fluid communication with one or more ports of a hub connector (e.g., hub connector 140) to which the IVL catheter 300 may be connected. The fluid lumen 402 of the hypotube 330 may additionally be in fluid communication with the fluid lumen 310 defined by the inner shaft 304, outer shaft 306, and / or other components of the catheter shaft 302. In this regard, the fluid lumen 402 may be regarded as a proximal fluid lumen of the catheter shaft 302, and the fluid lumen 310 may be regarded as a distal fluid lumen of the catheter shaft 302. The fluid lumen 402 of the hypotube 330 may serve as a conduit for conveying fluid (e.g., inflation fluid for inflating the enclosure member 320) and / or other componentry (e.g., wires, elongated components for communicating with the emitters 314) through the IVL catheter 300.

[0065] In some implementations, the hypotube 330 is configured to increase the pushability of the IVL catheter 300. For instance, the hypotube 330 may extend toward the distal tip of the IVL catheter 300 to increase the rigidity and column strength of the IVL catheter 300 along the longitudinal length of the IVL catheter 300. Additionally, or alternatively, the hypotube 330 may gradually alter the rigidity of the IVL catheter 300Docket No. 23812.33.1a 11along its longitudinal length. For example, the IVL catheter 300 may be less rigid, or more flexible, near the distal tip of the IVL catheter 300 (or within the enclosure member 320) and may be more rigid at more proximal points along the length of the IVL catheter 300 (e.g., proximal to the RX port 326). The hypotube 330 may increase the pushability and / or resistance to kinking of the IVL catheter 300 without interfering with operation of the emitters 314.

[0066] In the example shown in Figure 3, the distal section 334 of the hypotube 330 is axially aligned (or axially overlaps) with the RX port 326 of the catheter shaft 302. Under such an arrangement, the proximal section 332 may extend proximally from the distal section 334 toward the hub connector (e.g., hub connector 140). The distal section 334 may provide a gradual reduction in stiffening structure as the IVL catheter 300 extends toward the distal tip thereof.

[0067] In the example shown in Figure 3, the distal section 334 of the hypotube 330 defines a skived portion 336 of the hypotube 330. In some instances, the skived portion 336 extends along the entire length of the distal section 334 and may delineate the proximal section 332 of the hypotube 330 from the distal section 334. The skived portion 336 may be formed by applying one or more cuts to the hypotube wall at the distal section 334 of the hypotube 330 to form a radially discontinuous hypotube wall (e.g., where the hypotube wall no longer extends along the full circumference).

[0068] As illustrated in Figure 3, the skived portion 336 may extend distally from the proximal section 332 (e.g., with a reduced circumferential extent relative to the proximal section 332) into the interior of the enclosure member 320 and into proximity to the emitters 314 disposed within the enclosure member 320. For instance, the skived portion 336 may comprise blocking features 338 that are axially aligned with the emitters 314 within the enclosure member 320. The blocking features 338 may at least partially block or mitigate the propagation of pressure waves generated via the emitters 314. For instance, the blocking features 338 may block or mitigate pressure wave propagation in one or more radial directions outward from the spark generation region(s) of the emitters 314 toward the blocking features 338 (e.g., in the downward direction from the perspective shown in Figure 3). Such features may allow practitioners to focus IVL therapy application away from or toward desired regions of vessel walls, which may improve treatment precision.

[0069] The blocking features 338 of the hypotube 330 may be defined by the radially discontinuous hypotube wall that forms the skived portion 336 of the hypotube 330. In some instances, one or more blocking plates or other components may be affixed to theDocket No. 23812.33.1a 12skived portion 336 of the hypotube 330 to operate as the blocking features 338. The blocking features 338 may comprise material(s) with a higher acoustic impedance than the inflation fluid used to inflate the enclosure member 320.

[0070] Figure 4 illustrates a perspective view of the skived portion 336 of the hypotube 330 of the IVL catheter 300. Figure 4 illustrates the fluid lumen 402 defined by the proximal section 332 of the hypotube 330. The fluid lumen 402 may comprise a substantially circular cross-sectional profile as shown, or any other suitable profile (e.g., ovular, square, hexagonal, etc.) and may be in fluid communication with the fluid lumen 310 of the catheter shaft 302. In some implementations, the hypotube 330 may comprise a wall thickness within a range of about 0.003 inches and about 0.009 inches. Figure 3 illustrates the reduced circumferential extent of the hypotube wall that forms the skived portion 336 (relative to the full circumferential extent of the hypotube wall at the proximal section 332). The distal end of the skived portion 336 may terminate at a blunt / flat surface (as shown in Figure 4), a point, or another configuration.

[0071] In the example shown in Figure 4, the skived portion 336 of the hypotube 330 comprises three distinct segments, including a first angled segment 404, an axial segment 406, and a second angled segment 408, such that the skived portion 336 reduces in circumferential extent distally along the axial length of the skived portion 336. The first angled segment 404 and the second angled segment 408 may comprise gradually reducing circumferential extents (in the proximal -to-distal direction), whereas the axial segment 406 may comprise a substantially constant circumferential extent along its axial length. The first angled segment 404 and the second angled segment 408 may comprise angled cut surfaces that may embody the same angle of inclination or different angles of inclination. In the example shown in Figure 4, the angled cut surfaces of the first angled segment 404 and the second angled segment 408 may form angled linear profiles (e.g., sloped side profiles), though other cut surface profiles are possible (e.g., curved, parabolic, or arcuate side profiles).

[0072] The first angled segment 404, the axial segment 406, and / or the second angled segment 408 may have the same or different axial lengths. In one or more examples, the first angled segment 404 and / or the second angled segment 408 may comprise an axial length G within a range of about 1 mm to about 30 mm. In one or more embodiments where the hypotube 330 terminates in a blunt end (e.g., as shown in Figure 4), the distalmost end of the hypotube 330 may comprise a height H within a range of about 5%Docket No. 23812.33.1a 13to about 25% of the outer diameter of the proximal section 332 of the hypotube 330. For example, the height H may be within a range of about 0.003 inches to about 0.007 inches.

[0073] In some implementations, the axial segment 406 may comprise an axial length within a range of about 10 mm to about 40 mm. The axial segment 406 may comprise a height C within a range of about 20% to about 50% of the outer diameter of the proximal section 332 of the hypotube 330. For example, the height C may be within a range of about 0.005 inches to about 0.01 inches. In some instances, the overall axial length of the distal section 334 (or skived portion 336) of the hypotube 330 is within a range of about 20 mm to about 250 mm (e.g., about 40 mm).

[0074] In some implementations, the inner diameter and / or the outer diameter of the hypotube 330 (e.g., at the proximal section 332) is within a range of about 0.02 inches to about 0.04 inches. In some instances, transitions between segments of the hypotube 330 (e.g., from the proximal section 332 to the first angled segment 404, from the first angled segment 404 to the axial segment 406, from the axial segment 406 to the second angled segment 408, etc.) may be radiused. For example, as shown if Figure 4, a proximal end of the first angled segment 404 may include a radius R within a range of about 0.02 inches to about 0.06 inches (e.g., about 0.04 inches).

[0075] In some embodiments, the skived portion 336 is sized and dimensioned to extend through the interior of the enclosure member 320 toward the distal tip of the IVL catheter 300, where the distal end of the skived portion 336 may be fixed to part of the distal tip of the IVL catheter 300 (e.g., fixed to the inner shaft 304 at a distal region thereof). In some implementations, a hypotube extender or extension member is affixed to the skived portion 336 and extends distally from the skived portion 336 into engagement with part of the distal tip of the IVL catheter 300. Such features may increase the rigidity and / or resistance to kinking of the IVL catheter 300 when crossing a lesion.

[0076] Although Figures 3 and 4 focus, in at least some respects, on an example in which the distal section 334 of the hypotube 330 includes a first angled segment 404, an axial segment 406, and a second angled segment 408, other configurations are possible. For instance, a skived portion of a hypotube may include a first angled segment that gradually decreases in circumferential extent until reaching the distal end of the hypotube. In another example, the skived portion of the hypotube may include a first angled segment and an axial segment, where the axial segment distally terminates at the distal end of the hypotube. As another example, the skived portion of a hypotube may include two or more angled segments that directly adjoin one another (e.g., without an intervening axialDocket No. 23812.33.1a 14segment). As yet another example, the skived portion of a hypotube may include more than three distinct segments and may include any combination of angled and axial segments.

[0077] Figure 5 illustrates a top view of part of an example skived portion 536 of a hypotube of an IVL catheter. Similar to the skived portion 336, described above, the skived portion 536 may extend distally from a proximal portion of a hypotube and may comprise a radially discontinuous hypotube wall. Figure 5 illustrates blocking features 538 of the skived portion 536, which may be configured to axially align with emitters disposed within an enclosure member of an IVL catheter when assembled.

[0078] Figure 5 illustrates the blocking features 538 as being positioned among adjacent sections 540 of the skived portion 536, which may be positioned proximal to, distal to, or between the blocking features 538. In the example shown in Figure 5, the blocking features 538 comprise greater circumferential extent than the adjacent sections 540 of the skived portion 536. Such a configuration may allow the blocking features 538 to extend circumferentially about a desired region of an associated emitter to achieve desired pressure wave blocking characteristics while still enabling control of the amount of rigidity imparted by the skived portion 536 on the IVL catheter of which the skived portion 536 is a part. For instance, where blocking features and adjacent sections of a skived portion comprise the same circumferential extent, a large circumferential extent may cause the skived portion may impart excess rigidity to the distal region of the IVL catheter (which may affect navigability of the IVL catheter), whereas a small circumferential extent may limit the ability of the blocking portions to control pressure wave propagation. Accordingly, by implementing blocking features 538 with a greater circumferential extent than adjacent sections 540 (as shown in Figure 5), a desired balance between rigidity and pressure wave control characteristics of the skived portion 536 may be achieved.

[0079] Figure 6 illustrates an axial cross-sectional view of the IVL catheter 300 shown in Figure 3, taken from the cross-section labeled 6-6 in Figure 3. Figure 6 illustrates a blocking feature 338 of the skived portion 336 axially aligned with an emitter 314 and disposed within the enclosure member 320. In the example shown in Figure 6, the blocking feature 338 circumferentially extends over an angle A relative to the central longitudinal axis of the hypotube 330 (or of the IVL catheter 300 or other components thereof, such as the emitter 314). In some implementations, the angle A is at least 75 degrees (or at least 90 degrees) to permit the blocking feature 338 to mitigate propagation of pressure wavesDocket No. 23812.33.1a 15through the circumferential arc occupied by the blocking feature. As noted above, the circumferential extent of the blocking feature 338 (i.e., A) may be greater than the circumferential extent of one or more adjacent sections of the skived portion 336 (e.g., proximal and / or distal sections).

[0080] Figure 6 furthermore illustrates that the blocking feature 338 may be radially spaced apart from the emitter 314 by radial spacing D. In some instances, the radial spacing D between the blocking feature 338 and the emitter 314 may prevent the blocking features 338 from disrupting operation of the emitter 314 to generate pressure waves. For instance, the radial spacing D may be greater than a spark gap distance (e.g., the distance of spark gaps 854A, 854B shown in Figure 8) associated with the emitter 314, which may mitigate the possibility of arcing between the emitter 314 and the blocking feature 338.

[0081] The blocking feature 338 shown in Figure 6 comprises a curved or arcuate cross-sectional shape, though other shapes are within the scope of the present disclosure. In some instances, the material (e.g., metallic) and / or shape of the blocking feature 338 permits the blocking feature 338 to at least partially reflect pressure waves generated via the emitter 314, which may increase IVL therapy output at a region radially opposite the blocking feature 338 relative to the emitter 314 (e.g., above the emitter 314, from the perspective shown in Figure 6). Such functionality may add to available IVL treatment options and versatility.

[0082] In some implementations, a hypotube of an IVL catheter shaft may comprise an electrically conductive material, allowing the hypotube to operate as an electrically conductive path for communicating with distal components of the IVL catheter, such as emitters. Such functionality may enable IVL catheter designs to omit one or more wires or other elongated components that would otherwise be needed to facilitate communication with emitters. Such omissions may contribute to a reduced crossing profile, which can improve IVL catheter maneuverability.

[0083] Figure 7 illustrates an axial cross-sectional view of an example IVL catheter 700. The cross-sectional view shown in Figure 7 is taken from an axial location similar to that shown in Figure 6 (e.g., at an axial location where an emitter and a skived portion of a hypotube are present). The IVL catheter 700 may generally correspond to the IVL catheter 300 described hereinabove. For instance, the IVL catheter 700 may comprise an emitter 714, an enclosure member 720, a catheter shaft 702 defining a guidewire lumen for a guidewire 708, and / or other components similar to those described hereinabove with reference to the IVL catheter 300.Docket No. 23812.33.1a 16

[0084] In the example shown in Figure 7, the IVL catheter 700 includes a hypotube 730 that includes a skived portion 736 formed from a radially discontinuous hypotube wall of the hypotube 730. The skived portion 736 shown in Figure 7 extends into the interior of the enclosure member 720 and into electrical communication (e.g., electrical contact) with the emitter 714. For instance, the emitter 714 may comprise a metal body, and the hypotube 730 may abut one or more surfaces of the metal body. As depicted in Figure 7, a curved inner surface of the skived portion 736 radially abuts a curved outer surface of the emitter 714. Other configurations are possible, such as where a distal end surface of the skived portion 736 extends into axial abutment with a proximal end surface of the emitter 714.

[0085] With the skived portion 736 in electrical communication with the emitter 714, the hypotube 730 may facilitate electrical communication between the emitter 714 and one or more proximal components. For instance, the hypotube 730 may be operatively connected to a terminal (e.g., a ground or return terminal) of an electrical pulse generator (e.g., power source 102), while the emitter 714 may be operatively connected (e.g., via one or more wires) to another terminal (e.g., a supply terminal) of the electrical pulse generator, allowing the hypotube 730 and the emitter 714 to form a circuit for generating pressure waves. Such a configuration may allow the electrical pulse generator to deliver a high- voltage electrical pulse to the emitter 714 to generate an electrical arc or spark across a spark gap defined by the emitter 714 (e.g., a gap between an uninsulated portion of the metal body of the emitter 714 and an uninsulated portion of the wire connected to the electrical pulse generator).

[0086] In implementations where an IVL catheter includes multiple emitters, the hypotube may be positioned in electrical communication with each of the emitters. For instance, the skived portion of the hypotube may be placed in radial abutment with outer surfaces of each of the emitters (e.g., similar to the configuration shown in Figure 7). Alternatively, the hypotube may be positioned in electrical contact with fewer than all of the emitters, and one or more electrical bridging elements may be implemented to allow the hypotube to form an electrical circuit with the other / remaining emitters. For instance, the skived portion of the hypotube may be placed in axial abutment with a proximal surface of a metal body of a first emitter, and a bridging wire or other conductor may electrically connect the metal body of the first emitter to the metal body of another emitter. One will appreciate, in view of the present disclosure, that the connection configurations described / shown herein are provided by way of example only and do not limit the scope of the presently disclosed subject matter. Variations and / or alterations on theDocket No. 23812.33.1a 17configurations shown are within the scope of the present disclosure (e.g., in the form of intervening members / components between connection surfaces, additional / altemative connection surfaces, etc.).

[0087] Figures 8 and 9 illustrate diagrams depicting example electrical connections among components of an IVL system. Figure 8 illustrates a conceptual representation of a hypotube 830 including a skived portion 836, as well as emitters 814A and 814B with wires 850A and 850B connecting the emitters 814A and 814B, respectively, to an electrical pulse generator 802 (e.g., similar to power source 102). Figure 8 conceptually depicts the hypotube 830 electrically connected to a return terminal of the electrical pulse generator 802 (e.g., via connector 856). The wires 850A and 850B may connect the emitters 814A and 814B, respectively, to one or more supply terminals of the electrical pulse generator 802, such that the emitters 814A and 814B are independently addressable. For example, the wires 850A and 850B may connect to different supply terminals of the electrical pulse generator 802, or may connect to a common supply terminal using a switch framework.

[0088] The emitter 814A may comprise an electrode pair, where an exposed portion of the wire 850A acts as one electrode and an exposed portion of a metal body 852A of the emitter 814A acts as another electrode for the electrode pair. A spark gap 854A may be formed between the electrodes of the emitter 814A, permitting electrical arcing across the spark gap 854A to generate pressure waves for IVL therapy. Similarly, the emitter 814B may comprise an electrode pair, where an exposed portion of the wire 850B acts as one electrode and an exposed portion of a metal body 852B of the emitter 814B acts as another electrode for the electrode pair. A spark gap 854B may be formed between the electrodes of the emitter 814B, permitting electrical arcing across the spark gap 854B to generate pressure waves for IVL therapy.

[0089] In the example shown in Figure 8, the skived portion 836 of the hypotube 830 is electrically connected to metal body 852A (i.e., an electrode of emitter 814A) and to metal body 852B (i.e., an electrode of emitter 814B). Under the configuration shown in Figure 8, the hypotube 830 may operate as a common electrical return path for voltage pulses delivered from the electrical pulse generator 802 to both of the emitters 814A and 814B via the wires 850A and 850B, respectively. As noted above, the emitters 814A and 814B may be individually addressable by the electrical pulse generator 802, enabling voltage pulses to be selectively delivered to one or both of the emitters 814A and / or 814B for selective spark generation at the spark gaps 854A and / or 854B. By leveraging theDocket No. 23812.33.1a 18hypotube 830 as a common electrical return path, individual electrical return paths may be omitted for the emitters 814A and 814B, which may contributed to improved device crossing profile.

[0090] Similar to Figure 8, Figure 9 illustrates a conceptual representation of a hypotube 930 including a skived portion 936, as well as emitters 914A and 914B with wires 950A and 950B. Figure 9 conceptually depicts the hypotube 930 electrically connected to a terminal of the electrical pulse generator 902 (e.g., via connector 956). In the example shown in Figure 9, the emitters 914A and 914B are connected in-series. For instance, wire 950A connects emitter 914A to a terminal of the electrical pulse generator 902, while wire 950B connects emitter 914B to emitter 914A. Emitter 914A may comprise an electrode pair, with an exposed portion of wire 950A acting as one electrode and with an exposed portion of a metal body 952A of emitter 914A acting as another electrode. Similarly, emitter 914B may comprise an electrode pair, with an exposed portion of wire 950B acting as one electrode and with an exposed portion of a metal body 952B of emitter 914B acting as another electrode. The respective electrode pairs of the emitters 914A and 914B may define spark gaps 954 A and 954B.

[0091] In the example shown in Figure 9, the skived portion 936 of the hypotube 930 is electrically connected to metal body 952B (i.e., an electrode of emitter 914A) but is not in electrical contact with emitter 914A (e.g., the skived portion 936 may be radially spaced from emitter 914A with radial spacing that is greater than the distance of spark gap 954A). In this regard, the skived portion 936 may be electrically connected to the last (or first) emitter in the series topology of emitters (shown in Figure 9 as emitters 914B, though other configurations are possible). With emitter 914A connected to a terminal of the electrical pulse generator 902 via wire 950A, the in-series emitters 914A and 914B and the hypotube 930 (connected to another terminal of the electrical pulse generator 902) may form an electrical circuit for facilitating in-series spark generation at the emitters 914A and 914B. Under the configuration shown in Figure 9, the hypotube 930 may act as a return path or a supply path for spark generation.

[0092] Although Figures 8 and 9 focus, in at least some respects, on examples in which a hypotube is used for parallel (Figure 8) or series (Figure 9) electrical connections with two emitters, the principles shown and described with reference to Figures 8 and 9 (and elsewhere herein) may be generalized to any quantity of emitters (e.g., three or more).

[0093] In some implementations, a hypotube of an IVL catheter shaft may operate as an electrode of an electrode pair for generating spark for IVL therapy. For instance, FigureDocket No. 23812.33.1a 1910 illustrates an axial cross-sectional view of an example IVL catheter 1000. The cross- sectional view shown in Figure 10 is taken from an axial location where an electrode 1050 and a skived portion 1036 of a hypotube 1030 are present. The IVL catheter 1000 may be similar, in at least some respects, to the IVL catheter 300 described hereinabove. For instance, the IVL catheter 1000 may comprise an enclosure member 1020, a catheter shaft 1002 defining a guidewire lumen for a guidewire 1008, and / or other components similar to those described hereinabove with reference to the IVL catheter 300.

[0094] In the example shown in Figure 10, the IVL catheter 1000 includes a hypotube 1030 that includes a skived portion 1036 formed from a radially discontinuous hypotube wall of the hypotube 1030. The skived portion 1036 shown in Figure 10 extends into the interior of the enclosure member 1020 and into proximity with the electrode 1050 (e.g., a wire or other electrically conductive component). For instance, Figure 10 illustrates the skived portion 1036 as axially aligned with and radially spaced apart from the electrode 1050. The hypotube 1030 may comprise electrically conductive material and may be operatively connected to a terminal of an electrical pulse generator (e.g., power source 102). The electrode 1050 may similarly comprise electrically conductive material and may be operatively connected to another terminal of the electrical pulse generator (or to another electrode for an in-series connection).

[0095] Under the configuration shown in Figure 10, the positioning of the skived portion 1036 and the electrode 1050 may form a spark gap 1060 between the radially discontinuous hypotube wall that forms the skived portion 1036 and the electrode 1050 (e.g., an uninsulated portion thereof). The skived portion 1036 and the electrode 1050 may thus form an emitter (or an electrode pair for an emitter) that may generate pressure waves for IVL therapy via arcing between the skived portion 1036 and the electrode 1050 (e.g., upon delivery of an electrical pulse from an electrical pulse generator).

[0096] The skived portion 1036 may function as a supply path or a return path for spark generation under the configuration shown in Figure 10. IVL catheters that leverage the hypotube 1030 as an electrical path and as an electrode for spark generation for IVL therapy (e.g., as shown in Figure 10) may omit at least some electrical components (e.g., one or more wires or metal bodies) that would otherwise be present under different design frameworks, thereby potentially contributing to an improved crossing profile.

[0097] Although the example shown and described with reference to Figure 10 focuses, in at least some respects, on a single electrode pair (formed between the hypotube 1030 and the electrode 1050), the principles shown and described with reference to FigureDocket No. 23812.33.1a 2010 may be generalized to any quantity of electrode pairs (e.g., the skived portion 1036 may serve as an electrode for multiple electrode pairs, defining multiple spark gaps between (i) the skived portion 1036 and (ii) multiple different electrodes connected to the catheter shaft 1002). Where multiple spark gaps are formed between the skived portion 1036 and multiple electrodes, the electrodes may be connected to the electrical pulse generator in parallel (e.g., with each electrode being individually addressable). Furthermore, although Figure 10 depicts radial spacing between the skived portion 1036 and the electrode 1050 to form a spark gap 1060, spark gaps may be formed in other ways, such as via axial spacing between a distal end of the skived portion 1036 and a proximal part of an electrode.

[0098] Catheters used for intravascular lithotripsy (IVL) procedures may encounter challenges during navigation through patient vasculature, including difficulty advancing to a target lesion and a tendency to kink. Such difficulties may arise from the need to balance catheter rigidity, which may enhance pushability, with catheter flexibility, which may facilitate passage through tortuous vessel anatomies. A catheter that is overly rigid may be pushable but may lack sufficient flexibility to track the vessel path without risking vessel injury. Conversely, a catheter that is overly flexible may navigate tortuous vessels but may lack the column strength desirable for advancing toward the target lesion without kinking. These challenges may be further amplified when crossing calcified or occluded regions of a vessel, which may increase resistance to catheter advancement and elevate the likelihood of kinking. Accordingly, catheters for use in IVL procedures may benefit from improved pushability and enhanced resistance to kinking.

[0099] The IVL catheters and systems disclosed herein may provide improved pushability and enhanced resistance to kinking. In some embodiments, a catheter may include one or more hypotubes and one or more tube extenders configured to increase the column strength of the catheter toward its distal region while maintaining flexibility that may support navigation through tortuous vessel anatomies. For example, a hypotube or tube extender may extend through an interior region of an enclosure member (e.g., a balloon or other at least partially flexible member) toward a distal tip of the catheter. In contrast with reinforcement structures of certain existing catheter designs that terminate proximal to an enclosure member and create an abrupt transition in stiffness, extending the hypotube or tube extender distally toward the catheter tip may mitigate or eliminate potential kink points and may improve catheter performance during lesion crossing.

[0100] Referring now to Figure 11, a diagrammatic cross section of a vessel illustrating an example activation of an intravascular lithotripsy catheter adjacent to aDocket No. 23812.33.1a 21calcified lesion in accordance with embodiments is shown. An intravascular lithotripsy (IVL) IVL catheter 1100 may be introduced into a bodily vessel or vessel 1102, such as a blood vessel, of a patient over a guidewire 1103. The IVL catheter 1100 includes an enclosure member 1104 mounted on a catheter shaft 1106. The vessel 1102, which serves as the target anatomy, contains a lesion 1108 within a vessel wall 1110. For instance, the lesion 1108 may be a calcified lesion 1108 restricting the flow of a medium, such as blood, through the vessel 1102.

[0101] As the IVL catheter 1100 is advanced through the vessel 1102, the enclosure member 1104 may be positioned adjacent to the calcified lesion 1108. Once in place, the enclosure member 1104 may be expanded against the vessel wall 1110. One or more emitters 1604 (Figure 16) that may be contained within the enclosure member 1104. The emitters 1604 may be activated to generate pressure pulses 1114. Examples include emitters 1604 providing electrical spark gaps, optical focusing elements or optical targets with optical fibers, or lumens and outlets for pressurized gas. Other mechanisms for generating the pressure pulses 1114 may be used.

[0102] The pressure pulses 1114 generated (e.g., by an electrical arc 1112) may cause one or more cracks 1116 to form in the calcified lesion 1108. These cracks 1116 disrupt the lesion 1108, making it more pliable and easier to treat with subsequent interventions, such as balloon angioplasty. The illustration demonstrates the mechanism by which the IVL catheter 1100 effectively targets and disrupts calcified lesions 1108 within the vessel 1102, thereby improving the safety and efficacy of percutaneous coronary interventions (PCI) in patients with heavily calcified lesions 1108.

[0103] Referring to Figure 12, a perspective view of an intravascular lithotripsy system in accordance with embodiments is shown. An IVL system 1200 includes an IVL catheter 1100 designed to disrupt calcified lesions 1108 within a vessel 1102, as described above. The IVL catheter 1100 comprises the enclosure member 1104 mounted on the catheter shaft 1106, which may be positioned adjacent to and expanded against a calcified lesion 1108 to facilitate the treatment of the lesion 1108.

[0104] The IVL system 1200 may also include a fluid pump 1202 that may be fluidically coupled to the enclosure member 1104. The fluid pump 1202 may be used to inflate and deflate the enclosure member 1104 during the procedure. For example, the fluid pump 1202 may convey a saline solution or mixture to the enclosure member 1104 to expand the enclosure member 1104 against the vessel wall 1110. By controlling the fluid pressure within the enclosure member 1104, the fluid pump 1202 ensures that theDocket No. 23812.33.1a 22enclosure member 1104 may be precisely positioned and expanded to effectively target the calcified lesion 1108. This controlled inflation and deflation facilitate accurate delivery of lithotripsy energy to the lesion 1108.

[0105] The IVL catheter 1100 may be electrically connected to an IVL control system 1204 via a control handle 1206. The IVL control system 1204 may include an electric pulse generator that generates the electrical signals required to activate the emitters 1604 within the enclosure member 1104. For example, the IVL control system 1204 may include a memory storing system settings and / or other instructions which, when executed by a processing device of the IVL system 1200, cause the IVL system 1200 to transmit the electrical signals to the control handle 1206. These electrical signals are transmitted through the control handle 1206 to the emitters 1604, which then generate the electrical arc 1112. The electrical arc 1112 produces the pressure pulses 1114 that propagate outward toward the calcified lesion 1108. Accordingly, the IVL control system 1204 may provide the electrical energy to power the lithotripsy procedure.

[0106] The control handle 1206 may serve as a user interface for the IVL system 1200. The control handle 1206 may allow the user to manage the operation of the IVL catheter 1100, including the activation of the emitters 1604. Optionally, the control handle 1206 may control inflation and deflation of the enclosure member 1104 when a fluid delivery system is integral to the IVL control system 1204 (not shown). The control handle 1206 typically features buttons or other input mechanisms that the user may press to generate the electrical arc 1112 and produce the pressure pulse 1114. The control handle 1206 interface ensures that the clinician may easily and effectively control the IVL system 1200 during the procedure.

[0107] Referring to Figure 13, a side view of an over-the-wire intravascular lithotripsy catheter in accordance with embodiments is shown. The IVL catheter 1100 may have an over-the-wire (OTW) guidewire configuration. In the OTW configuration, the guidewire 1103 may enter the IVL catheter 1100 through a distal catheter tip and exit the catheter through a hub 1302. The OTW configuration allows for precise navigation and positioning of the IVL catheter 1100 within the vessel 1102. The guidewire 1103 provides a stable pathway for the catheter, enabling the clinician to accurately target the calcified lesion 1108. Once the catheter is in position, the enclosure member 1104 may be expanded, and the emitters 1604 may be activated to generate the pressure pulses 1114 that disrupt the lesion 1108.Docket No. 23812.33.1a 23

[0108] The IVL catheter 1100 includes the enclosure member 1104 mounted on the catheter shaft 1106, as described below. The catheter shaft 1106 may provide structural support and serves as a conduit for the guidewire 1103, inflation fluid, and electrical connections necessary for the operation of the IVL system 1200. For example, the catheter shaft 1106 may connect to the hub 1302, which conveys inflation fluid and electrical signals between a distal portion of the IVL catheter 1100 and external components. The hub 1302 may pass electrical signals between the control handle 1206 and the emitters 1604 within the enclosure member 1104 to produce the pressure pulses 1114, as described above. For example, the electrical signals may travel along wires in an electrical cable 1304 of the control handle 1206, which connects to the hub 1302. The wires may extend through the hub 1302 and into the catheter shaft 1106 and extend distally to the emitters 1604 in the enclosure member 1104.

[0109] In addition to the electrical connection, the hub 1302 may also include a fluid connector 1306 to pass inflation fluid from the fluid pump 1202 to the enclosure member 1104. This fluid connector 1306 may convey inflation fluid between the fluid pump 1202 and a fluid passageway in the catheter shaft 1106, through the hub 1302. The inflation fluid may travel along the catheter shaft 1106 into the enclosure member 1104 to inflate and deflate the enclosure member 1104 during a procedure.

[0110] Referring to Figure 14, a side view of a rapid exchange intravascular lithotripsy catheter in accordance with an embodiment is shown. The IVL catheter 1100 may have a rapid exchange (RX) guidewire configuration. As in the OTW guidewire configuration, the RX version of the IVL catheter 1100 may include the catheter shaft 1106, the enclosure member 1104, and the hub 1302. The hub configuration and guidewire routing of the RX configuration may, however, differ from the OTW configuration.[OHl] In an embodiment, the hub 1302 may be located at a proximal end of the catheter shaft 1106. The hub 1302 may include the electrical connector 1504, to allow for the transmission of electrical signals from the IVL control system 1204 to the emitters 1604 within the enclosure member 1104, and the fluid connector 1306, to enable the passage of the inflation fluid from the fluid pump 1202 to the enclosure member 1104. The hub 1302 may not, however, have an exit port for the guidewire 1103. The exit port may be an RX port 1402 positioned distal to the hub 1302 along the catheter shaft 1106.

[0112] The RX port 1402 may be positioned between the distal tip and the hub 1302 of the IVL catheter 1100. The RX port 1402 may include a hole defined in an outer surface of the catheter shaft 1106 that allows the guidewire 1103 to transition from a locationDocket No. 23812.33.1a 24external to the catheter shaft 1106 to a location internal to the catheter shaft 1106 (e.g., supporting the enclosure member 1104). In an embodiment, the guidewire 1103 may enter the IVL catheter 1100 through the distal catheter tip and exit through the RX port 1402. The RX configuration allows for quick and efficient exchange of the guidewire 1103, facilitating precise navigation and positioning of the IVL catheter 1100 within the vessel 1102. The RX port 1402 provides a stable pathway for the catheter, enabling the clinician to accurately target the calcified lesion 1108.

[0113] Referring to Figure 15, a side view of a control handle 1206 of an intravascular lithotripsy catheter in accordance with embodiments is shown. The control handle 1206 of the IVL catheter 1100 includes the electrical cable 1304, a grip 1502, an electrical connector 1504, and a control element 1506. The control handle 1206 may serve as a user interface for the IVL system 1200. For instance, the grip 1502 may provide a surface for a user to hold and manipulate the control handle 1206 during the procedure. The grip 1502 may be ergonomically designed to ensure comfort and ease of use for the user.

[0114] The electrical cable 1304 may connect the control handle 1206 to the hub 1302 of the intravascular lithotripsy catheter. The electrical cable 1304 transmits electrical signals from the IVL control system 1204 to the emitters 1604 within the enclosure member 1104 of the catheter. The electrical connector 1504 may be positioned at the proximal end of the control handle 1206. The electrical connector 1504 may connect to the IVL control system 1204. The electrical connector 1504 may receive the electrical signals generated by the IVL control system 1204, which then transmit through the electrical cable 1304 to the hub 1302 and subsequently to the emitters 1604 within the enclosure member 1104.

[0115] The control element 1506 may be integrated into the grip 1502 of the control handle 1206. The control element 1506 may include one or more buttons, switches, or other input mechanisms. The user may actuate the control element 1506 to activate the emitters 1604 within the enclosure member 1104. This activation generates the electrical arc 1112, which produces the pressure pulses 1114 necessary for the lithotripsy procedure. The control element 1506 allows the clinician to precisely control the timing and intensity of the electrical signals, ensuring effective treatment of the calcified lesions 1108. The control handle 1206, with the integrated grip 1502, electrical cable 1304, electrical connector 1504, and control element 1506, provides the interface for the clinician to manage the operation of the intravascular lithotripsy catheter. This design ensures that theDocket No. 23812.33.1a 25clinician may easily and effectively control the lithotripsy procedure, enhancing the safety and efficacy of the treatment.

[0116] Referring to Figure 16, a cutaway perspective view of a distal portion 1610 of an intravascular lithotripsy catheter, in accordance with an embodiment. A catheter tip 1602 may be positioned at a distal end of the IVL catheter 1100. As described above, the catheter tip 1602 facilitates the navigation of the catheter over the guidewire 1103 through the vessel 1102 to the target lesion 1108. The catheter tip 1602 may be designed to be atraumatic to minimize damage to the vessel walls 1110 during the procedure, ensuring safe and effective advancement of the catheter to the site of the calcified lesion 1108. For instance, the catheter tip 1602 may receive and track over the guidewire 1103 to the target anatomy within the vessel 1102.

[0117] The enclosure member 1104 may be mounted on the catheter shaft 1106 and may be positioned adjacent to the catheter tip 1602. For instance, a distal end of the enclosure member 1104 may be coupled (e.g., sealed) to the catheter tip 1602 and a proximal end of the enclosure member 1104 may be coupled (e.g., sealed) to the catheter shaft 1106. The enclosure member 1104 may therefore provide a hermetically sealed interior longitudinally between the catheter tip 1602 and the catheter shaft 1106. The enclosure member 1104 may serve as a medium for the transmission of pressure pulses 1114 generated by an emitter 1604 within the interior of the enclosure member 1104. For instance, the emitter 1604 may generate the electrical spark that produces the pressure pulses 1114 used to disrupt the calcified lesion 1108.

[0118] The IVL catheter 1100 may include an inner member 1606, which may be integral to the catheter shaft 1106. For instance, the catheter shaft 1106 may include the inner member 1606 located within an outer member 1608. The outer member 1608 may support the proximal end of the enclosure member 1104. The inner member 1606 may extend through the enclosure member 1104 to the catheter tip 1602. The inner member 1606 supports the emitter 1604 and may also provide a pathway for the guidewire 1103. The inner member 1606 may ensure the proper alignment and positioning of the emitter 1604 within the enclosure member 1104, which facilitates the effective generation and transmission of pressure pulses 1114 to the calcified lesion 1108.

[0119] The emitter 1604 may be contained within the enclosure member 1104 and may be responsible for generating the electrical arc 1112 that produces the pressure pulses 1114. The emitter 1604 may include one or more portions separated by a spark gap 1605 across which the spark is generated. When electrical signals from the IVL control systemDocket No. 23812.33.1a 261204 are transmitted to the emitter 1604, the electrical spark forms across the spark gap 1605 between the portion(s) of the emitter 1604. For example, the enclosure member 1104 may be filled with saline or another electrolytic solution that supports formation of the electrical spark. The spark creates the electrical arc 1112, which in turn produces the pressure pulses 1114 that propagate outward through the inflation fluid and the enclosure member wall toward the calcified lesion 1108.

[0120] In some embodiments, the catheter shaft 1106 may include braided reinforcement member to increase the pushability of the IVL catheter 1100. The braided reinforcement member may be embedded within the wall of the inner member 1606, the outer member 1608, or both the inner member 1606 and the outer member 1608. The braided reinforcement member may be made of stainless steel, nitinol, cobalt chromium alloys, and / or other materials. In some embodiments, the catheter shaft 1106 includes markers 1612 to aid in positioning the IVL catheter 1100 within the vessel 1102. For example, the markers 1612 may be radiopaque such that the markers are easily identifiable within the patient during a lithotripsy procedure with the aid of imaging technology (e.g., X-ray imaging). The markers 1612 may be located at or on the inner member 1606, the outer member 1608, or both with a known relation to the emitters 1604. For example, two markers 1612 may be positioned on the inner member 1606 with all of the emitters 1604 between the two markers 1612. The markers 1612 may be laser welded to the catheter shaft 1106 to reduce the crossing profile of the IVL catheter 1100. In some embodiments, the markers 1612 may be ink based to reduce the crossing profile of the IVL catheter 1100.

[0121] In embodiments, the IVL catheter 1100 may have a hydrophilic coating. For example, the distal portion 1610 may have a hydrophilic coating. The hydrophilic coating may be any hydrophilic coating known in the art. For example, the hydrophilic coating may be polyethylene oxide (PEG), polybetaines, polyampholytes, polyacrylamide, polyvinyl pyrrolidine, poly (N-vinyl lactams), or polyvinyl alcohol (PVOH) based coatings.

[0122] Referring to Figure 17, a sectional view of a catheter shaft 1106 of an intravascular lithotripsy catheter in accordance with embodiments is shown (from the perspective indicated by section A-A in Figure 16). The catheter shaft 1106 serves as a structural component of the intravascular lithotripsy catheter. The catheter shaft 1106 provides support and houses various internal components of the IVL catheter 1100. For example, the catheter shaft 1106 includes the outer member 1608 and the inner member 1606.Docket No. 23812.33.1a 27

[0123] The outer member 1608 may be the outermost layer of the catheter shaft 1106. The outer member 1608 provides structural support and protection for the internal components of the IVL catheter 1100. The outer member 1608 may be designed to be biocompatible and flexible, allowing the IVL catheter 1100 to navigate through the vascular system without causing damage to the vessel walls 1110. The outer member 1608 may include a tubular wall extending along a longitudinal axis from the hub 1302 to the enclosure member 1104.

[0124] The inner member 1606 may be located within the outer member 1608 and may provide additional structural support. The inner member 1606 may include a tubular wall extending along the longitudinal axis (e.g., coaxial with the outer member 1608). The inner member 1606 may house a guidewire lumen 1702, through which the guidewire 1103 may pass. Accordingly, the inner member 1606 may extend from the hub 1302 to the catheter tip 1602, in the OTW version of the IVL catheter 1100, or from the RX port 1402 to the catheter tip 1602, in the RX version of the IVL catheter 1100. It will be appreciated that, in the RX version, a hypotube (not shown in cross-section, but proximal to the RX port 1402 in Figure 14) may connect the hub 1302 to the distal portion 1610 of the IVL catheter 1100. For instance, the hypotube may be a tubular member having a lumen to provide a fluid channel and convey inflation fluid from the fluid connector 1306 into a fluid passageway 1704 that extends into the enclosure member 1104.

[0125] The fluid passageway 1704 may be an internal channel within the catheter shaft 1106 between the inner member 1606 and the outer member 1608. The fluid passageway 1704 may allow inflation fluid to be delivered to the enclosure member 1104. The fluid passageway 1704 may be an annular space, as shown, or may be a circular space (e.g., within the hypotube of the RX version of the IVL catheter 1100). In any case, the fluid passageway 1704 permits the passage of the inflation fluid (e.g., a saline solution or mixture) into the enclosure member 1104 to support inflation and spark generation. In some implementations, the fluid passageway 1704 may serve as the second fluid lumen of the catheter shaft and may receive fluid communicated from the first fluid lumen of the hypotube 1810. Such fluid communication may support fluid insertion and / or withdrawal into and / or from an enclosure member coupled to the catheter shaft 1106. In some embodiments, the interior of the enclosure member 1104 may be in fluid communication with the second fluid lumen of the catheter shaft 1106. This fluid communication may support fluid insertion and / or withdrawal for the enclosure member 1104, includingDocket No. 23812.33.1a 28operations involving inflation, deflation, flushing, or establishing a desired internal fluid state during activation of one or more emitters (e.g., emitters 1604).

[0126] In an embodiment, one or more wires 1706 are positioned within the catheter shaft 1106 and used to transmit electrical signals from the control handle 1206 to the emitters 1604 within the enclosure member 1104. For example, each emitter 1604 may be connected to one or more wires 1706 to electrify portions of the emitter 1604 and generate the electrical arc 1112. Each wire 1706 may be insulated to prevent electrical interference with other components of the IVL catheter 1100.

[0127] Insulation of the wire(s) 1706 may also be provided by a wire sheath 1708 that surrounds the wires 1706, providing additional insulation and protection. The wire sheath 1708 may, for example, be a tubular member or heat shrink that encases the wires 1706 between the wire sheath 1708 and the inner member 1606. The wires 1706 may therefore be separated from inflation fluid within the fluid passageway 1704. Accordingly, the wires 1706 may remain securely in place within the catheter shaft 1106 and prevents any potential damage or electrical leakage during navigation of the IVL catheter 1100 through the vessel 1102.

[0128] Referring to Figure 18 A, a section view of the distal portion 1610 of the IVL catheter 1100 is shown in accordance with embodiments of the present disclosure. The distal portion 1610 may include a hypotube 1810 and / or a tube extender 1850. The hypotube 1810 and the tube extender 1850 are configured to increase the pushability of the IVL catheter 1100. For instance, the hypotube 1810 and the tube extender 1850 may extend to the catheter tip 1602 of the IVL catheter 1100 to increase the rigidity and column strength of the IVL catheter 1100 along the entire length of the IVL catheter 1100. Additionally, or alternatively, the hypotube 1810 and the tube extender 1850 may gradually alter the rigidity of the IVL catheter 1100 along its longitudinal length. For example, the IVL catheter 1100 may be less rigid (e.g., more flexible) near the catheter tip 1602 become more rigid at more proximal points along the length of the IVL catheter 1100. The hypotube 1810 and the tube extender 1850 increase the pushability of the IVL catheter 1100 without interfering with operation of the emitters 1604. For example, the hypotube 1810 and the tube extender 1850 may be radially spaced apart from the emitters 1604 to avoid inadvertent discharge of an emitter 1604 and such that the pressure pulses 1114 are not disrupted during a lithotripsy procedure. In some embodiments, a distal region 1860 of the catheter shaft 1106 may be positioned distal to the emitters 1604, and at least a portion of the tube extender 1850 may extend toward and connect or be fixed toDocket No. 23812.33.1a 29this distal region 1860 (e.g., to the inner member 1606) through an interior portion of the enclosure member 1804. The distal region 1860 may include the portions / features of the inner member 1606 and / or the catheter tip 1602 that are distal to the one or more emitters 1604. Such positioning may maintain desired spatial relationships among the emitters 1604, the enclosure member 1104, the tube extender 1850, and the distal region 1860 of the catheter shaft 1106.

[0129] The enclosure member 1104 may be bonded the catheter shaft 1106 of the IVL catheter 1100. For instance, the enclosure member 1104 may be bonded to the catheter shaft 1106 at a proximal end portion 1805 of the enclosure member 1104 and a distal end portion 1806 of the enclosure member 1104. The proximal end portion 1805 of the enclosure member 1104 and the distal end portion 1806 of the enclosure member 1104 may each be bonded to different elements of the catheter shaft 1106. For example, as shown in Figure 18 A, the proximal end portion 1805 of the enclosure member 1104 may be bonded to the outer member 1608 and the distal end portion 1806 of the enclosure member 1104 may be bonded to the inner member 1606. In some embodiments, the proximal end portion 1805 of the enclosure member 1104 and the distal end portion 1806 of the enclosure member 1104 may be bonded to the same element of the catheter shaft 1106. For example, each of the proximal end portion 1805 of the enclosure member 1104 and the distal end portion 1806 of the enclosure member 1104 may be bonded to the outer member 1608 or the inner member 1606. The enclosure member 1104 may be bonded to the catheter shaft 1106 with the distal end portion 1806 of the enclosure member 1104 spaced apart from the catheter tip 1602. For example, the distal end portion 1806 of the enclosure member 1104 may be bonded to the inner member 1606 proximal of the catheter tip 1602 such that a length of the inner member 1606 between the catheter tip 1602 and the distal end portion 1806 of the enclosure member 1104 is exposed, as shown in Figure 18 A.

[0130] Additionally referring to Figure 18B, another section view of the distal portion 1610 of the IVL catheter 1100 including another enclosure member 1804 is shown in accordance with embodiments of the present disclosure. The enclosure member 1804 includes a tail 1807 that defines a passage 1808. When the distal end portion 1806 of the enclosure member 1804 is bonded to the catheter shaft 1106 (e.g., the inner member 1606) the tail 1807 may extend distally from catheter tip 1602 with the passage 1808 coaxially aligned with the guidewire lumen 1702. The tail 1807 may be made of the same material as the enclosure member 1804. In such an embodiment, the tail 1807 may be more flexibleDocket No. 23812.33.1a 30than the inner member 1606 or the outer member 1608 and may aid in navigation of torturous anatomies of the vessel 1102. For example, the flexibility of the tail 1807 may allow the tail 1807 to follow the vessel wall 1110 to guide the IVL catheter 1100 through the vessel 1102.

[0131] Referring to Figures 19 and 20, the hypotube 1810 has a proximal section 1902 and a distal section 1904 with a central lumen 1906 defined therethrough along a longitudinal axis L-L of the hypotube 1810. The central lumen 1906 of the hypotube 1810 may have a substantially circular cross-sectional profile as shown, or any other suitable profile (e.g., ovular, square, or hexagonal) and may be in fluid communication with the fluid passageway 1704 when the hypotube 1810 is positioned within the catheter shaft 1106. The hypotube 1810 may have a wall thickness of between about 0.003 inches and about 0.009 inches.

[0132] The distal section 1904 of the hypotube 1810 may have a skive 1908 defined by reduction in the cross-sectional dimension, (e.g., reduction in the diameter or reduction in the circumferential extent of the hypotube wall of the hypotube 1810), of the hypotube 1810 along the longitudinal axis L-L or axial length of the hypotube 1810. The skive 1908 may extend along the entire length of the distal section 1904 and may delineate the proximal section 1902 of the hypotube 1810 from the distal section 1904. The hypotube 1810 may be substantially tubular and may have a monolithic construction. In some embodiments, the central lumen 1906 of the hypotube 1810 may operate as a first fluid lumen of the catheter shaft, and the fluid passageway 1704 may operate as a second fluid lumen of the catheter shaft. The first fluid lumen may be in fluid communication with the second fluid lumen so that fluid conveyed proximally through the hypotube 1810 may continue distally through one or more portions of the catheter shaft 1106 to support inflation, deflation, or flushing of an enclosure member (e.g., enclosure member 1804) positioned along the distal portion of the catheter shaft (e.g., catheter shaft 1106). In some embodiments, removal or omission of material along the skive 1908 may reduce the circumferential extent of the hypotube wall such that the distal section 1904 comprises a radially discontinuous hypotube wall. A radially discontinuous hypotube wall may include any configuration in which one or more regions of the hypotube wall are interrupted, relieved, or otherwise non-continuous around the circumference of the hypotube.

[0133] When the hypotube 1810 is positioned within the catheter shaft 1106, the hypotube 1810 may extend along only a portion of the length of the catheter shaft 1106. For example, the hypotube 1810 may be positioned within the catheter shaft 1106 (e.g.,Docket No. 23812.33.1a 31within the fluid passageway 1704) with the distal section 1904 aligned with the RX port 1402, as shown in Figure 18 A, and with the proximal section 1902 extending proximally, towards the hub 1302, but short of reaching the hub 1302. The skive 1908 may improve pushability and resistance to kinking by providing a gradual reduction in stiffening structure as the IVL catheter 1100 extends towards the catheter tip 1602.

[0134] In embodiments, the skive 1908 of the hypotube 1810 may have three distinct segments comprising a first angled segment 1910, an axial segment 1920, and a second angled segment 1930 such that the hypotube 1810 reduces in cross-sectional dimension distally along the skive 1908. The first angled segment 1910 may be the most proximal portion of the skive 1908 and may delineate between the proximal section 1902 and the distal section 1904 of the hypotube 1810. The axial segment 1920 may be disposed between the first angled segment 1910 and the second angled segment 1930. The second angled segment 1930 may extend from the axial segment 1920 to the most distal end of the hypotube 1810. In embodiments, the second angled segment 1930 may be such that the hypotube 1810 terminates in a point at its most distal end. In some embodiments, the second angled segment 1930 may be such that the hypotube 1810 terminates in a blunt end at its most distal end.

[0135] Briefly referring to Figures 21 and 22, the hypotube 1810 may have only the first angle segment 1910 and the axial segment 1920. For example, another hypotube 1810a is shown in Figure 21 including only the first angled segment 1910 and the axial segment 1920. In other embodiments, a hypotube 1810b may only have the first angled segment 1910 as shown in Figure 22. In embodiments, the skive 1908 may have more than three distinct segments. The skive 1908 may alternate between axial segments and angled segments along the longitudinal length of the hypotube 1810. For example, the skive 1908 may have four distinct segments, two angled segments and two axial segments, ordered as follows: first angled segment, first axial segment, second angled segment, second axial segment.

[0136] Returning to Figures 19 and 20, the first angled segment 1910 and the second angled segment 1930 each may have a linear or straight angled configuration as depicted. In some embodiments, the first angled segment 1910 and the second angled segment 1930 each may be curved, such as a parabolic like curve. The first angled segment 1910 and the second angled segment 1930 may have the same angle of inclination or may have different angles of inclination. In some embodiments, the first angled segment 1910 and the second angled segment 1930 are substantially parallel with each other. The first angled segmentDocket No. 23812.33.1a 321910 extends at a first angle relative the longitudinal axis L-L of the hypotube 1810 and the second angled segment 1930 extends at a second angle relative the longitudinal axis L-L of the hypotube 1810 such that the first angle is different from the second angle.

[0137] The first angled segment 1910, the axial segment 1920, and the second angled segment 1930 may have the same or varying lengths. For example, the second angled segment 1930 may have an axial length G between approximately between about 20 mm and about 30 mm. In embodiments where the hypotube 1810 terminates in a blunt end, the distal most end may have a distal height H ranging approximately between approximately 5% to approximately 25% of the outer diameter of the hypotube 1810. For example, the height H may be approximately 0.003 inches to approximately 0.007 inches.

[0138] The axial segment 1920 may have an axial length approximately ranging between 10 mm and 40 mm. The axial segment 1920 may have a height C between the outside surface of the wall of the hypotube 1810 and the edge of the axial segment 1920 that ranges approximately between about 20% to about 50% of the outer diameter of the hypotube 1810. For example, the height C may range between about 0.005 inches and about 0.01 inches. The axial segment 1920 may comprise a segment in which the circumferential extent of the hypotube wall of the hypotube 1810 remains substantially constant distally along the axial length (e.g., longitudinal axis L-L) of the hypotube 1810.

[0139] The inside diameter 0B of the hypotube 1810 may be approximately 0.02 inches to approximately 0.04 inches and the outside diameter 0A of the hypotube 1810 may be approximately 0.02 inches to approximately 0.04 inches. The first angled segment 1910 may have a height approximately equivalent to the outside diameter of the hypotube 1810. Accordingly, the first angled segment 1910 may have an overall height when measured from a side of between about 50% to approximately 1100% of the outer diameter of the hypotube 1810. The first angled segment 1910 may comprise a segment in which the circumferential extent of the hypotube wall of the hypotube 1810 reduces along the axial length (e.g., longitudinal axis L-L) of the hypotube 1810.

[0140] In some embodiments, an end of one or more of the angled segments 1910, 1930 may be radiused for transition between the first angled segment 1910, axial segment 1920, and the second angled segment 1930. For example, as shown if Figure 19, a proximal end of the first angled segment 1910 may include a radius R. The radius may be approximately 0.02 to approximately 0.06 inches (e.g., approximately R 0.04 inches). The overall axial length of the skive 1908 with respect to the first angled segment 1910, the axial segment 1920, and the second angled segment 1930 may range from approximatelyDocket No. 23812.33.1a 331100 mm to 1200 mm. The second angled segment 1930 may comprise a segment in which the circumferential extent of the hypotube wall of the hypotube 1810 reduces along the axial length (e.g., longitudinal axis L-L) of the hypotube 1810.

[0141] In some embodiments, the skive 1908 of the hypotube 1810 may be sized and dimensioned to extend to the catheter tip 1602 of the IVL catheter 1100 (or to the distal region 1860). For instance, the skive 1908 may extend through the interior of the enclosure member 1104 toward the catheter tip 1602 (e.g., into the distal region 1860). For example, in embodiments including the hypotube 1810a, shown in Figure 21, the axial segment 1920 may extend through the interior of the enclosure member 1104 toward the catheter tip 1602 (e.g., into the distal region 1860). The end of the skive 1908 may be fixed to one or more features of the distal region 1860 (e.g., distal features of the inner member 1606 and / or the catheter tip 1602). For example, the distalmost end of the axial segment 1920 of the hypotube 1810a may be fixed to the inner member 1606 at or near the catheter tip 1602. In such an embodiment, a separate tube extender 1850 may be omitted. For instance, the axial segment 1920 may functionally replace the tube extender 1850 (or may itself be regarded as a tube extender) further described herein below. Accordingly, the skive 1908 may increase the rigidity of the catheter shaft 1106 to resist kinking when the IVL catheter 1100 crosses the lesion 1108.

[0142] Referring to Figures 23 and 24, a corrugated hypotube 2300 in accordance with embodiments of the present disclosure is shown. The corrugated hypotube 2300 may replace the hypotube 1810. The corrugated hypotube 2300 has a wall 2302 that defines a central lumen 2304 extending through the corrugated hypotube 2300 and a plurality of grooves 2306 extending along the corrugated hypotube 2300 on an outer surface of the wall 2302 (e.g., the outer tube surface of the wall 2302 defines the plurality of grooves 2306). Although Figures 23 and 24 illustrate a plurality of grooves, the outer tube surface of the wall 2302 may define any quantity of grooves (e.g., one or more grooves). The wall 2302 may have uniform thickness. For instance, the wall 2302 may have a uniform thickness between about 0.003 inches and about 0.009 inches. The corrugated hypotube 2300 may be a substantially tubular structure as shown. In some embodiments, the corrugated hypotube 2300 may include a skive 1908 as described above with respect to the hypotube 1810, 1810a, 1810b.

[0143] The grooves 2306 are configured to receive and retain components of the IVL catheter 1100 or the IVL system 1200. For example, the wires 1706 may be received within the grooves 2306. Each groove 2306 may receive one or more of the wires 1706. EachDocket No. 23812.33.1a 34groove 2306 may have a gate 2308 at the outer surface of the wall 2302 that is sized and dimensioned to receive a wire 1706 therethrough and into the groove 2306. The gates 2308 may have a dimension slightly smaller than the diameter of the wire 1706 received in the respective groove 2306 to resist withdrawal of the wire 1706 from the groove 2306. For example, in some embodiments, the grooves 2306 may have substantially circular crosssection with a diameter that is approximately equal to the diameter of the wire 1706 to be received within the groove 2306. In such an embodiment, the grooves 2306 may have gates 2308 defined along a chord of the circular cross-sectional profile that is less than the diameter of the circular cross-sectional profile of the groove 2306 to retain the wire 1706 in the groove 2306.

[0144] Referring to Figure 25, a multi-filar hypotube 2500 in accordance with embodiments of the present disclosure is shown. The multi-filar hypotube 2500 may be defined by a plurality of thin, elongated members, or filars 2502, that each extend between a distal end and a proximal end of the multi-filar hypotube 2500. Each of the filars 2502 are arranged to form and define a central lumen 2504. The central lumen 2504 may extend along the entire length of the multi-filar hypotube 2500. In some embodiments, the inside diameter of the multi-filar hypotube 2500 (e.g., the diameter of the central lumen 2504) may be in a range of 0.003 inches to 0.09 inches. The outside diameter of the multi-filar hypotube 2500 may be in a range of 0.05 inches to 0.16 inches. Each filar 2502 may have diameter in a range of 0.001 inches to 0.05 inches. The filars 2502 may have a circular cross-section. In some embodiments, the filars 2502 may have an oblong cross-section. In particular embodiments, the multi-filar hypotube 2500 may be an HSS® tube from Fort Wayne Metal sTM.

[0145] The multi-filar hypotube 2500 may have a plurality of layers. For example, the multi-filar hypotube 2500 may have inner layer 2506, an intermediate layer 2508, and an outer layer 2510. In some embodiments, the multi-filar hypotube 2500 may include more than three layers (e.g., two, three, or more than three intermediate layers 2508). In certain embodiments, the multi-filar hypotube 2500 may have only two layers (e.g., the inner layer 2506 and the outer layer 2510). Each layer 2506, 2508, 2510 may be formed of a plurality of the filars 2502. The filars 2502 may have the same size and dimension or may be different sizes and dimension. For example, the filars 2502 of each respective layer 2506, 2508, 2510 may increases in size and dimension from the inner layer 2506 to the outside layer 2510. for example, the filars 2502 of the inner layer 2506 may have a first size and dimension, the filars 2502 of the intermediate layer 2508 may have a second size andDocket No. 23812.33.1a 35dimension that is larger than that of the filars 2502 of the inner layer 2506, and, the filars 2502 of the outer layer 2510 may have a third size and dimension that is larger than the filars 2502 of the intermediate layer 2508.

[0146] In embodiments, each layer 2506, 2508, 2510 may have the same number of filars 2502 or may have a different number of filars 2502. In embodiments, each layer 2506, 2508, 2510 may have a number of filars 2502 in a range of three filars 2502 to twenty filars 2502. Increasing the sized and dimension to of the filars 2502 in each respective layer 2506, 2508, 2510 may allow for each layer 2506, 2508, 2510 to have the same number of filars 2502. Each layer 2506, 2508, 2510 may have a helical construction with a pitch. The pitch may be defined as the angle each filar 2502 of a respective layer 2506, 2508, 2510 with respect to a central longitudinal axis of multi-filar hypotube 2500. For example, a layer 2506, 2508, 2510 having a pitch of 0 degrees would have filars 2502 parallel to the central longitudinal axis of the multi-filar hypotube 2500. A layer 2506, 2508, 2510 having a pitch of 90 degrees would have filars 2502 perpendicular to the central longitudinal axis of the multi-filar hypotube 2500. The pitch of adjacent layers 2506, 2508, 2510 may be opposite of each other. For example, the inner layer 2506 may have a left pitch or counterclockwise pitch, the intermediate layer 2508 may have a right pitch or clockwise pitch, and the outer layer 2510 may have a left pitch or counterclockwise pitch.

[0147] Referring to Figures 19, 26, and 27, the tube extender 1850 extends through the fluid passageway 1704 between the hypotube 1810 and the catheter shaft 1106 to the catheter tip 1602 to increase rigidity and pushability of the IVL catheter 1100 without interfering with the emitters 1604. The tube extender 1850 may be attached to the exterior surface of the hypotube 1810 or the interior surface of the outer member 1608. In embodiments including the corrugated hypotube 2300, the tube extender 1850 may be received within one of the grooves 2306 to attach the tube extender 1850 to the corrugated hypotube 2300. A distal most end of the tube extender 1850 may extend through the interior of the enclosure member 1104 to the catheter tip 1602. The distal most end of the tube extender 1850 may be fixed to the catheter tip 1602. For example, the tube extender 1850 may be fixed to the inner member 1606. In some embodiments, the tube extender 1850 may have a distal taper such that the thickness of the tube extender 1850 reduces as the tube extender 1850 extends towards the catheter tip 1602. Tapering the tube extender 1850 may gradually reduce the stiffness along the length of the IVL catheter 1100. The tube extender 1850 may be made of, but is not limited to, stainless steel or nitinol. In some embodiments, the tube extender 1850 may originate at, be connected to, extend from,Docket No. 23812.33.1a 36and / or be positioned adjacent to the distal section 1904 of the hypotube 1810. Under such arrangements, the tube extender 1850 may extend distally from the distal section 1904 toward a distal region 1860 of the catheter shaft 1106 while maintaining a spacing relationship relative to the emitters (e.g., emitters 1604) positioned within the enclosure member 1804 of the IVL catheter 1100.

[0148] The tube extender 1850 extends through the enclosure member 1104, to the catheter tip 1602, such that it does not interfere with the emitters 1604. For example, the tube extender 1850 may be radially spaced apart from the emitters 1604. Spacing the tube extender 1850 apart from the emitters 1604 may prevent contact between the emitters 1604 and the tube extender 1850 and may prevent inadvertent formation of the pressure pulses 1114. For instance, spacing the tube extender 1850 apart from the emitters 1604 may prevent the electrical arc 1112 from forming between the emitters 1604 and the tube extender 1850, which may prevent formation the pressure pulses 1114. In embodiments, the tube extender 1850 may be spaced apart from the emitters 1604 a distance that is greater than a width of the spark gap 1605 defined between portions of a respective emitter 1604. Spacing the tube extender 1850 a distance greater than a width of the spark gap 1605 from the emitters 1604 may prevent the electrical arc 1112 from forming between the emitters 1604 and the tube extender 1850. For example, the electrical resistance between the emitters 1604 and the tube extender 1850 may be higher than the electrical resistance across the spark gap 1605. In embodiments, the distance the tube extender 1850 is spaced apart from the emitters 1604 may be in a range of 0.003 inches to 0.02 inches (e.g., 0.005, 0.007, or 0.01 inches). In some implementations, at least a portion of the tube extender 1850 may extend through an interior of the enclosure member 1804 of the IVL catheter 1100. Such extension through the interior of the enclosure member 1804 may provide structural reinforcement along the distal region 1860 of the catheter shaft 1106 while preserving separation between the tube extender 1850 and one or more emitters 1604 disposed within the enclosure member 1804.

[0149] In embodiments, as described above, where the skive 1908 of the hypotube 1810 extends to the catheter tip 1602 and the tube extender 1850 is omitted, the skive 1908 may be spaced apart from the emitters 1604 a distance greater than a width of the spark gap 1605. For example, the axial segment 1920 may be spaced apart from the emitters 1604 a distance in a range of 0.003 inches to 0.02 inches (e.g., 0.005, 0.007, or 0.01 inches).Docket No. 23812.33.1a 37

[0150] In embodiments, the hypotube 1810 may maintain the distance between the emitters 1604 and the tube extender 1850. For example, with the tube extender 1850 positioned between the catheter shaft 1106 and the hypotube 1810, the thickness of the wall of the hypotube 1810 may define a minimum distance between the emitters 1604 and the tube extender 1850. For example, as shown in Figure 19, the skive 1908, or a portion of the skive 1908, of the hypotube 1810 may be between the tube extender 1850 and the inner member 1606 to space the tube extender 1850 and the inner member 1606, and thus the emitters 1604, apart at least a distance approximately equal to the thickness of the wall of the hypotube 1810.

[0151] The tube extender 1850 may be formed of a material that is not electrically conductive to prevent interference with emitters 1604. For example, the tube extender 1850 may be formed of a polymeric material such as, but not limited to, polycarbonate (PC), polyethylene, polypropylene (PP), or acrylonitrile butadiene styrene (ABS). In some embodiments, the tube extender 1850 may be a metallic member with an electrically insulative coating to prevent interference with emitters 1604. For example, the electrically insulative coating may be, but is not limited to, silicone, polyurethane, or polyvinyl chloride (PVC). In some embodiments, the electrically insulative coating may be the same material as the wire sheath 1708. Forming the tube extender 1850 from an electrically non- conductive material or coating the tube extender 1850 in an insulative coating may prevent the electrical arc 1112 from forming between the emitters 1604 and the tube extender 1850. Such embodiments may allow for the tube extender 1850 to be positioned closer to the emitters 1604. In some embodiments with a non-conductive or electrically insulated tube extender 1850, the tube extender 1850 may be in physical communication with the emitters 1604 without interfering with the emitters 1604 or the formation of the pressure pulses 1114. Such an embodiment may decrease the crossing profile of the IVL catheter 1100. Additionally, in embodiments where the IVL catheter 1100 omits the tube extender 1850 for a hypotube 1810 having a skive 1908 that extends to the catheter tip 1602, the hypotube 1810 may be formed of a non-conductive material or may have an electrically insulative coating to prevent interfering the emitters 1604. In some embodiments, only the portions of the tube extender 1850 or the hypotube 1810 within the interior of the enclosure member 1104 may be coated in an electrically insulative material. For example, only the axial segment 1920 may be coated in an electrically insulative material.

[0152] In embodiments, the IVL catheter 1100 may include more than one tube extender 1850. For example, two tube extenders 1850 may be disposed on opposite sidesDocket No. 23812.33.1a 38of the hypotube 1810. In embodiments including the corrugated hypotube 2300, the two tube extenders 1850 may be received within a respective one of the grooves 2306 to attach the tube extenders 1850 to the corrugated hypotube 2300.

[0153] Additionally referring to Figures 28A-28E, several example cross-sectional profiles of the tube extender 1850 in accordance with embodiments of the present disclosure are shown.

[0154] Referring to Figure 28 A, a tube extender 1850a having D-shaped cross- sectional profile is shown. The D-shaped cross-sectional profile of the tube extender 1850a includes a flat portion 1852a and a half round portion 1854a. The tube extender 1850a may have width, along the flat portion 1852a, in a range of 0.005 inches to 0.080 inches and may have a thickness, from the flat portion 1852a to the apex of the half round portion 1854a, in a range of 0.003 inches to 0.05 inches. The tube extender 1850a may be positioned within the catheter shaft 1106 in an over half round configuration or an under half round configuration. In the over half round configuration, the flat portion 1852a faces away from the emitters 1604. In the under half round configuration, the flat portion 1852a faces towards the emitters 1604, as shown in Figures 26 and 27.

[0155] Referring to Figure 28B, another tube extender 1850b having a crescent cross- sectional profile is shown. The tube extender 1850b has an outer side 1852b and an inner side 1854b. The tube extender 1850b may have width between ends in a range of 0.005 inches to 0.080 inches and may have a thickness between the outer side 1852b and an inner side 1854b in a range of 0.005 to 0.04 inches. Both the outer side 1852b and the inner side 1854b are arcuate. The outer side 1852b and an inner side 1854b may each have the same radius or, in some embodiments, have different radii. The tube extender 1850b may be positioned within the catheter shaft 1106 in a crescent up configuration or a crescent down configuration. In the crescent up configuration, the inner side 1854b faces towards the emitters 1604. In the crescent down configuration, the inner side 1854b faces away from the emitters 1604.

[0156] Referring to Figure 28C, another tube extender 1850c having a pie shaped cross-sectional profile is shown. The tube extender 1850c has a crust side 1852c and slice side 1854c. In the example shown, the crust side 1852c is arcuate and the slice side 1854c is angular. The tube extender 1850c may have a width in a range of 0.005 inches to 0.080 inches and may have a thickness in a range of 0.005 inches to 0.04 inches. The angle of the slice side 1854c may be a range of 30 degrees to 1135 degrees. The tube extender 1850c may be positioned within the catheter shaft 1106 in a crust up configuration or aDocket No. 23812.33.1a 39crust down configuration. In the crust up configuration, the crust side 1852c faces the emitter 1604. In the crust down configuration, the crust side 1852c faces away from the emitters 1604.

[0157] Referring to Figure 28D, another tube extender 1850d having an elliptical cross-sectional profile is shown. The elliptical tube extender 1850d may have width along the major diameter in a range of 0.005 inches to 0.01 inches and may have a thickness along the minor diameter in a range of 0.002 inches to 0.005 inches.

[0158] Referring to Figure 28E another tube extender 1850e having a triangular cross- sectional profile is shown. The tube extender 1850e may have a profile of an equilateral triangle. In some embodiments, the tube extender 1850e may have a profile of an isosceles triangle or a profile of a scalene triangle. The tube extender 1850 may have a width, along the base, in a range of 0.004 inches to 0.080 inches and may have a thickness, or height, in a range of 0.004 inches to 0.05 inches. The tube extender 1850e may be positioned within the catheter shaft 1106 in a base up configuration or a base down configuration. In the base down configuration, the base of the triangular tube extender 1850e faces away from the emitters 1604. In the base up configuration, the base of the triangular tube extender 1850e faces towards the emitters 1604. Other profiles, of the tube extenders 1850 are contemplated and may include, but are not limited to, square, rectangular, round, star shaped, I-beam shaped, or grooved similarly to that of the corrugated hypotube 2300. In embodiments, the tube extenders 1850a, 1850b, 1850c, 1850d, 1850e may be a shaped wire from Fort Wayne Metal sTM.

[0159] Referring to Figure 29, the catheter shaft 1106 may include a stiffener 2900 configured to stiffen the catheter shaft 1106 along the longitudinal length of the catheter shaft 1106. The stiffener 2900 may improve the pushability of the catheter shaft 1106. The stiffener 2900 may be embedded within the wall of the catheter shaft 1106. For example, the stiffener 2900 may be imbedded within the wall of the inner member 1606, the outer member 1608, or both the inner member 1606, and the outer member 1608. The stiffener 2900 may be a wire helically wrapped along the longitudinal length of catheter shaft 1106. In such an embodiment, the stiffener 2900 may be a single wire of monolithic construction. The stiffener 2900 may be helically wrapped to have a constant pitch along the length of the catheter shaft 1106. In some embodiments, stiffener 2900 may be helically wrapped to have a variable pitch along the length of the catheter shaft 1106. For example, the pitch of the stiffener 2900 may increase as the stiffener 2900 extends distally along the catheterDocket No. 23812.33.1a 40shaft 1106. Where the stiffener 2900 has a variable pitch the stiffness of the catheter shaft 1106 may gradually lessen along its longitudinal length.

[0160] In some embodiments, the stiffener 2900 may be a plurality of rings disposed along the longitudinal length of the catheter shaft 1106. The rings may be disposed along the catheter shaft 1106 uniformly spaced apart from each other. In some embodiments, the rings may be variably spaced from each other. For example, each respective ring may be closer to the adjacent ring in the proximal direction along the catheter shaft 1106 than the adjacent ring in the distal direction along the catheter shaft 1106.

[0161] As described above, the catheter shaft 1106 may define an RX port 1402. The stiffener 2900 may reinforce the RX port 1402 to resist buckling or kinking of the catheter shaft 1106 around the RX port 1402. For example, the RX port 1402 may be positioned between portions of the stiffener 2900. For example, as shown if Figure 29, the RX port 1402 may be positioned between portions of the stiffener 2900. In some embodiments, the catheter shaft 1106 may have the stiffener 2900 located only around the RX port 1402.

[0162] Referring to Figure 30, a flowchart illustrating a method 3000 performing intravascular lithotripsy in accordance with embodiments of the present disclosure is shown. The method 3000 is described with references to the IVL catheter 1100 and the IVL system 1200 of Figures 11-29.

[0163] The guidewire 1103 may be inserted into the vessel 1102 (step 3010). The guidewire 1103 may be inserted into the vessel 1102 by any conventional method known to the clinician.

[0164] The guidewire 1103 may be advanced through the vessel 1102 to the lesion 1108 (Step 3020). In embodiments, the guidewire 1103 may be advanced via the grip 1502. In some embodiments, the guidewire 1103 may be advanced manually (e.g., by hand by a clinician). For example, the guidewire 1103 may be manually advanced in embodiments including the RX port 1402.

[0165] Once the guidewire 1103 reaches the lesion 1108, the catheter shaft 1106 may be advanced over the guidewire 1103 to position the enclosure member 1104 within the vessel 1102 across the lesion 1108, as shown in Figure 11 (Step 3030). The enclosure member 1104 may be positioned with the aid the markers 1612. For example, the marker 1612 may be radiopaque to allow for positioning withing the vessel 1102 with the aid of imaging technology (e.g., X-ray imaging).

[0166] The enclosure member 1104 may be inflated within the vessel 1102 (Step 3040). The enclosure member 1104 may be partially inflated or fully inflated. The amountDocket No. 23812.33.1a 41of inflation may depend on the extent of occlusion of the vessel 1102. The enclosure member 1104 may be inflated with a saline solution. Inflation of the enclosure member 1104 may partially dilate the vessel 1102. For example, the lesion 1108 or portions of the lesion 1108 may be partially calcified and may be compressed by inflation of the enclosure member 1104.

[0167] The enclosure member 1104 may be advanced and aligned with the lesion 1108 (Step 3050). For example, the enclosure member 1104 may be advanced from within a delivery catheter (not shown) into the vessel 1102. In such an embodiment, the inner member 1606 and the outer member 1608 may be advanced contemporaneously with each other to advance the enclosure member 1104, and the emitters 1604, into the vessel 1102. In some embodiments, the emitters 1604 may be advanced into the interior of the enclosure member 1104 after the enclosure member 1104 is aligned with the lesion 1108 within the vessel 1102. For example, the emitters 1604 may be disposed on the inner member 1606 and positioned by advancing the inner member 1606 into the interior of the enclosure member 1104. The emitters 1604 may be contemporaneously positioned at the lesion 1108 when the enclosure member 1104 is positioned within the vessel 1102, depending on the extent of the occlusion of the vessel 1102. In some embodiments, the emitters 1604 may be positioned after the enclosure member 1104 is positioned. The emitters 1604 may be positioned within the enclosure member 1104 before or after inflation of the enclosure member 1104. The tube extender 1850 and / or the skive 1908 of the hypotube 1810 may aid in crossing the lesion 1108. For example, the rigidity and column strength of the tube extender 1850 or the skive 1908 may slightly compress softer portions of the lesion 1108 as the IVL catheter 1100 crosses the lesion 1108, thus providing more clearance to advance the IVL catheter 1100.

[0168] With the emitters 1604 positioned in the vessel 1102 at the lesion 1108, pressure pulses 1114 are emitted from the emitters 1604 (Step 3060). Electrical energy may be delivered to the emitters 1604, through the wires 1706, causing the emitters 1604 to create pressure pulses 1114 in the inflation fluid. For example, the electrical energy may cause the emitters 1604 to create the electrical arc 1112. The electrical arc 1112 may cause a volume of the inflation fluid to vaporize. The vaporized inflation fluid may quickly condense and return to a liquid state due to the significantly cooler temperature of the surrounding un-vaporized inflation fluid. The rapid expansion from vaporization and / or the rapid collapse and condensation of the inflation fluid initiates the pressure pulses 1114 that propagate through the inflation fluid, the enclosure member 1104, and into the vesselDocket No. 23812.33.1a 42wall 1110. The pressure pulses 1114 disrupts the calcified lesion 1108 and causes the crack 1116 to form, without damaging the healthy portions of the vessel wall 1110.

[0169] The enclosure member 1104 may be further inflated to compress the cracked lesion 1108 (Step 3070). Further inflating the enclosure member 1104 may compress the lesion 1108 and dilate the vessel 1102 and restore blood flow through the vessel 1102 to a volume and pressure closer to that of an unoccluded vessel.

[0170] The Steps 3030 through 3070 may be repeated as necessary to achieve the desired clinical result. For example, steps 3060 and 3070 may be repeated with periods of delivering pressure pulses 1114 (Step 3060) alternated with periods of inflating the enclosure member 1104 (Step 3070) until the enclosure member 1104 is fully inflated. In some embodiments, the enclosure member 1104 and the emitters 1604 may be repositioned (e.g., via Steps 3030 through 3050) to treat a different lesion 1108 or another portion of the same lesion 1108. For example, the lesion 1108 may be longer than the length of the enclosure member 1104. In such a case, the enclosure member 1104 and emitters 1604 may be repositioned (e.g., by advancing farther into the vessel 1102) to treat the remaining, untreated portion of the lesion 1108.

[0171] Following treatment, the IVL catheter 1100 may be removed (Step 3080). To remove the IVL catheter 1100, the enclosure member 1104 may be deflated (e.g., by depressurizing the inflation fluid). The control handle 1206 may be used to retract the IVL catheter 1100 from the patient.

[0172] Although various examples provided herein characterize the enclosure members of IVL catheter as inflatable members, one will appreciate, in view of the present disclosure, that an enclosure member of an IVL catheter may comprise an at least partially flexible member configured to maintain a substantially consistent outer diameter and / or elongation characteristics when fluid is inserted into the interior of the enclosure member (e.g., when pressurized or fluid-filled), when fluid is withdrawn from the interior of the enclosure member, and / or or when fluid is flushed through the enclosure member. Accordingly, as used herein, “inflation” and / or “inflated” states may refer to “fluid-filling” and / or “fluid-filled” states, respectively, and “deflation” and / or “deflated” states may refer to “fluid-withdrawal” and / or “fluid-withdrawn” states.

[0173] It is contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments disclosed above may be made and still fall within one or more of the embodiments. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like inDocket No. 23812.33.1a 43connection with an embodiment can be used in all other embodiments set forth herein. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed embodiments. Thus, it is intended that the scope of the present disclosure herein disclosed should not be limited by the particular disclosed embodiments described above. Moreover, while the present disclosure is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the present disclosure is not to be limited to the particular forms or methods disclosed, but to the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any methods disclosed herein need not be performed in the order recited. One or more embodiments disclosed herein may omit one or more method acts or steps disclosed herein. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication.

[0174] Any ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “approximately”, “about”, or “substantially” as used herein include the recited numbers (e.g., about 10% includes 10%), and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, and “substantially” may refer to an amount that is within 10% of, within 5% of, within 1% of the stated amount.

[0175] For purposes of the present disclosure and appended claims, the conjunction “or” is to be construed inclusively (e.g., “an apple or an orange” would be interpreted as “an apple, or an orange, or both”; e.g., “an apple, an orange, or an avocado” would be interpreted as “an apple, or an orange, or an avocado, or any two, or all three”), unless: (i) it is explicitly stated otherwise, e.g., by use of “either. .. or,” “only one of,” or similar language; or (ii) two or more of the listed alternatives are mutually exclusive within the particular context, in which case “or” would encompass only those combinations involving non-mutually-exclusive alternatives. For purposes of the present disclosure and appended claims, the words “comprising,” “including,” “having,” and variants thereof, whereverDocket No. 23812.33.1a 44they appear, shall be construed as open-ended terminology, with the same meaning as if the phrase “at least” were appended after each instance thereof.

[0176] Following are some further example embodiments of the invention, represented by numbered clauses. These clauses are presented only by way of example and are not intended to limit the scope of the invention in any way. Further, any example embodiment can be combined with one or more of the example embodiments.

[0177] Clause 1. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, wherein the skived portion comprises one or more blocking features, wherein each of the one or more blocking features circumferentially extends at least 75 degrees; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the one or more blocking features of the skived portion extend into the interior of the enclosure member such that the one or more blocking features are axially aligned with the one or more emitters, the one or more blocking features being configured to modify propagation of pressure waves generated via the one or more emitters.

[0178] Clause 2. The IVL catheter of any preceding or subsequent clause, wherein each of the one or more blocking features circumferentially extends at least 90 degrees.

[0179] Clause 3. The IVL catheter of any preceding or subsequent clause, wherein the one or more blocking features are radially spaced from the one or more emitters.

[0180] Clause 4. The IVL catheter of any preceding or subsequent clause, wherein a radial spacing between the one or more blocking features and the one or more emitters is greater than a spark gap distance associated with the one or more emitters.

[0181] Clause 5. The IVL catheter of any preceding or subsequent clause, wherein the one or more blocking features are defined by the radially discontinuous hypotube wall.

[0182] Clause 6. The IVL catheter of any preceding or subsequent clause, wherein at least one blocking feature of the one or more blocking features comprises a greaterDocket No. 23812.33.1a 45circumferential extent than an adjacent section of the skived portion, the adjacent section being proximal or distal to the at least one blocking feature.

[0183] Clause 7. The IVL catheter of any preceding or subsequent clause, wherein the one or more blocking features are configured to at least partially reflect pressure waves generated via the one or more emitters to modify IVL therapy output at a region radially opposite the one or more blocking features relative to the one or more emitters.

[0184] Clause 8. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, the hypotube comprising an electrically conductive material, the hypotube being operatively connectable to a first terminal of an electrical pulse generator; one or more emitters connected to the catheter shaft, the one or more emitters being operatively connectable to one or more second terminals of the electrical pulse generator, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the skived portion extends into the interior of the enclosure member such that the radially discontinuous hypotube wall is in electrical communication with the one or more emitters.

[0185] Clause 9. The IVL catheter of any preceding or subsequent clause, wherein the hypotube and the one or more emitters form a circuit for generating the pressure waves when the hypotube is connected to the first terminal and the one or more emitters are connected to the one or more second terminals.

[0186] Clause 10. The IVL catheter of any preceding or subsequent clause, wherein the first terminal comprises a return terminal.

[0187] Clause 11. The IVL catheter of any preceding or subsequent clause, wherein the one or more emitters comprise a plurality of emitters.

[0188] Clause 12. The IVL catheter of any preceding or subsequent clause, wherein each of the plurality of emitters comprises a respective electrode pair defining a respective spark gap.Docket No. 23812.33.1a 46

[0189] Clause 13. The IVL catheter of any preceding or subsequent clause, wherein the radially discontinuous hypotube wall is electrically connected to a respective first electrode of each respective electrode pair of each of the plurality of emitters.

[0190] Clause 14. The IVL catheter of any preceding or subsequent clause, wherein a respective second electrode of each respective electrode pair of each of the plurality of emitters is electrically connectable to the one or more second terminals of the electrical pulse generator.

[0191] Clause 15. The IVL catheter of any preceding or subsequent clause, wherein the hypotube is configured to operate as a common electrical return path for voltage pulses delivered to each of the plurality of emitters.

[0192] Clause 16. The IVL catheter of any preceding or subsequent clause, wherein emitters of the plurality of emitters are connected in-series.

[0193] Clause 17. The IVL catheter of any preceding or subsequent clause, wherein the radially discontinuous hypotube wall is electrically connected to a first electrode of a first emitter of the plurality of emitters, and wherein a second electrode of a second emitter of the plurality of emitters is electrically connectable to the one or more second terminals of the electrical pulse generator.

[0194] Clause 18. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, the hypotube comprising an electrically conductive material, the hypotube being operatively connectable to a first terminal of an electrical pulse generator; one or more electrodes connected to the catheter shaft, the one or more electrodes being operatively connectable to one or more second terminals of the electrical pulse generator; and an enclosure member connected to the catheter shaft, wherein the one or more electrodes are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the skived portion extends into the interior of the enclosure member such that one or more spark gaps are defined between (i) the radially discontinuous hypotube wall and (ii) each of the one or more electrodes, wherein the one or more electrodes and the radiallyDocket No. 23812.33.1a 47discontinuous hypotube wall form one or more emitters configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy.

[0195] Clause 19. The IVL catheter of any preceding or subsequent clause, wherein the first terminal comprises a return terminal.

[0196] Clause 20. The IVL catheter of any preceding or subsequent clause, wherein the one or more electrodes comprise a plurality of electrodes.

[0197] Clause 21. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall; and a tube extender extending from the distal section of the hypotube to a distal region of the catheter shaft; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy, wherein the distal region of the catheter shaft is distal to the one or more emitters; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein at least part of the tube extender extends through an interior of the enclosure member, wherein the interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.

[0198] Clause 22. The IVL catheter of any preceding or subsequent clause, wherein the tube extender is radially spaced from the one or more emitters.

[0199] Clause 23. The IVL catheter of any preceding or subsequent clause, wherein the one or more emitters define at least one spark gap, and wherein the tube extender is radially spaced from the one or more emitters by a distance greater than a width of the at least one spark gap.

[0200] Clause 24. The IVL catheter of any preceding or subsequent clause, wherein the tube extender is radially spaced from the one or more emitters by a distance in a range of about 0.003 inches to about 0.02 inches.

[0201] Clause 25. The IVL catheter of any preceding or subsequent clause, wherein the tube extender comprises a flat portion and a rounded portion such that the tube extender comprises a substantially D-shaped cross-sectional profile.Docket No. 23812.33.1a 48

[0202] Clause 26. The IVL catheter of any preceding or subsequent clause, wherein the tube extender is arranged such that the flat portion is oriented radially inward toward the one or more emitters.

[0203] Clause 27. The IVL catheter of any preceding or subsequent clause, wherein the catheter shaft defines a guidewire lumen.

[0204] Clause 28. The IVL catheter of any preceding or subsequent clause, wherein the catheter shaft defines a rapid exchange port in communication with the guidewire lumen, wherein the rapid exchange port is located proximal to the enclosure member and is configured to receive a guidewire therethrough.

[0205] Clause 29. The IVL catheter of any preceding or subsequent clause, wherein the tube extender is fixed to the distal region of the catheter shaft.

[0206] Clause 30. The IVL catheter of any preceding or subsequent clause, wherein the skived portion comprises a first angled segment in which a circumferential extent of the radially discontinuous hypotube wall reduces distally along an axial length of the hypotube.

[0207] Clause 31. The IVL catheter of any preceding or subsequent clause, wherein the skived portion comprises an axial segment in which the circumferential extent of the radially discontinuous hypotube wall remains substantially constant distally along the axial length of the hypotube.

[0208] Clause 32. The IVL catheter of any preceding or subsequent clause, wherein the skived portion comprises a second angled segment in which the circumferential extent of the radially discontinuous hypotube wall reduces distally along the axial length of the hypotube.

[0209] Clause 33. The IVL catheter of any preceding or subsequent clause, wherein the axial segment is arranged distal to the first angled segment and proximal to the second angled segment.

[0210] Clause 34. The IVL catheter of any preceding or subsequent clause, wherein a hypotube wall of the hypotube comprises an outer tube surface that defines one or more grooves extending axially along the hypotube.

[0211] Clause 35. The IVL catheter of any preceding or subsequent clause, wherein a groove of the one or more grooves receives at least part of the tube extender to attach the tube extender to the hypotube.

[0212] Clause 36. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotubeDocket No. 23812.33.1a 49comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, wherein the distal section of the hypotube extends to and is fixed to a distal region of the catheter shaft; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy, wherein the distal region of the catheter shaft is distal to the one or more emitters; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.

[0213] Clause 37. The IVL catheter of any preceding or subsequent clause, wherein the skived portion is radially spaced from the one or more emitters.

[0214] Clause 38. The IVL catheter of any preceding or subsequent clause, wherein the one or more emitters define at least one spark gap, and wherein the skived portion is radially spaced from the one or more emitters by a distance greater than a width of the at least one spark gap.

[0215] Clause 39. The IVL catheter of any preceding or subsequent clause, wherein the skived portion is radially spaced from the one or more emitters by a distance in a range of about 0.003 inches to about 0.02 inches.

[0216] Clause 40. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, wherein a hypotube wall of the hypotube comprises an outer tube surface that defines one or more grooves extending axially along the hypotube; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.

[0217] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to beDocket No. 23812.33.1a 50considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.Docket No. 23812.33.1a 51

Claims

CLAIMSWhat is currently claimed is:

1. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, wherein the skived portion comprises one or more blocking features, wherein each of the one or more blocking features circumferentially extends at least 75 degrees; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the one or more blocking features of the skived portion extend into the interior of the enclosure member such that the one or more blocking features are axially aligned with the one or more emitters, the one or more blocking features being configured to modify propagation of pressure waves generated via the one or more emitters.

2. The IVL catheter of claim 1, wherein each of the one or more blocking features circumferentially extends at least 90 degrees.

3. The IVL catheter of claim 1, wherein the one or more blocking features are radially spaced from the one or more emitters.

4. The IVL catheter of claim 3, wherein a radial spacing between the one or more blocking features and the one or more emitters is greater than a spark gap distance associated with the one or more emitters.Docket No. 23812.33.1a 525. The IVL catheter of claim 1, wherein the one or more blocking features are defined by the radially discontinuous hypotube wall.

6. The IVL catheter of claim 1, wherein at least one blocking feature of the one or more blocking features comprises a greater circumferential extent than an adjacent section of the skived portion, the adjacent section being proximal or distal to the at least one blocking feature.

7. The IVL catheter of claim 1, wherein the one or more blocking features are configured to at least partially reflect pressure waves generated via the one or more emitters to modify IVL therapy output at a region radially opposite the one or more blocking features relative to the one or more emitters.

8. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, the hypotube comprising an electrically conductive material, the hypotube being operatively connectable to a first terminal of an electrical pulse generator; one or more emitters connected to the catheter shaft, the one or more emitters being operatively connectable to one or more second terminals of the electrical pulse generator, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the skived portion extends into the interior of the enclosure member such that the radially discontinuous hypotube wall is in electrical communication with the one or more emitters.

9. The IVL catheter of claim 8, wherein the hypotube and the one or more emitters form a circuit for generating the pressure waves when the hypotube is connected to theDocket No. 23812.33.1a 53first terminal and the one or more emitters are connected to the one or more second terminals.

10. The IVL catheter of claim 8, wherein the first terminal comprises a return terminal.

11. The IVL catheter of claim 8, wherein the one or more emitters comprise a plurality of emitters.

12. The IVL catheter of claim 11, wherein each of the plurality of emitters comprises a respective electrode pair defining a respective spark gap.

13. The IVL catheter of claim 12, wherein the radially discontinuous hypotube wall is electrically connected to a respective first electrode of each respective electrode pair of each of the plurality of emitters.

14. The IVL catheter of claim 13, wherein a respective second electrode of each respective electrode pair of each of the plurality of emitters is electrically connectable to the one or more second terminals of the electrical pulse generator.

15. The IVL catheter of claim 14, wherein the hypotube is configured to operate as a common electrical return path for voltage pulses delivered to each of the plurality of emitters.

16. The IVL catheter of claim 12, wherein emitters of the plurality of emitters are connected in-series.

17. The IVL catheter of claim 16, wherein the radially discontinuous hypotube wall is electrically connected to a first electrode of a first emitter of the plurality of emitters, and wherein a second electrode of a second emitter of the plurality of emitters is electrically connectable to the one or more second terminals of the electrical pulse generator.

18. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, the hypotube comprising an electrically conductive material, the hypotube being operatively connectable to a first terminal of an electrical pulse generator;Docket No. 23812.33.1a 54one or more electrodes connected to the catheter shaft, the one or more electrodes being operatively connectable to one or more second terminals of the electrical pulse generator; and an enclosure member connected to the catheter shaft, wherein the one or more electrodes are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member, wherein the skived portion extends into the interior of the enclosure member such that one or more spark gaps are defined between (i) the radially discontinuous hypotube wall and (ii) each of the one or more electrodes, wherein the one or more electrodes and the radially discontinuous hypotube wall form one or more emitters configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy.

19. The IVL catheter of claim 18, wherein the first terminal comprises a return terminal.

20. The IVL catheter of claim 18, wherein the one or more electrodes comprise a plurality of electrodes.

21. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall; and a tube extender extending from the distal section of the hypotube to a distal region of the catheter shaft; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy, wherein the distal region of the catheter shaft is distal to the one or more emitters; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein at least part of the tube extender extends through an interior of the enclosure member, wherein the interior of the enclosure member is in fluid communication with the second fluidDocket No. 23812.33.1a 55lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.

22. The IVL catheter of claim 21, wherein the tube extender is radially spaced from the one or more emitters.

23. The IVL catheter of claim 22, wherein the one or more emitters define at least one spark gap, and wherein the tube extender is radially spaced from the one or more emitters by a distance greater than a width of the at least one spark gap.

24. The IVL catheter of claim 23, wherein the tube extender is radially spaced from the one or more emitters by a distance in a range of about 0.003 inches to about 0.02 inches.

25. The IVL catheter of claim 21, wherein the tube extender comprises a flat portion and a rounded portion such that the tube extender comprises a substantially D-shaped cross-sectional profile.

26. The IVL catheter of claim 25, wherein the tube extender is arranged such that the flat portion is oriented radially inward toward the one or more emitters.

27. The IVL catheter of claim 21 , wherein the catheter shaft defines a guidewire lumen.

28. The IVL catheter of claim 27, wherein the catheter shaft defines a rapid exchange port in communication with the guidewire lumen, wherein the rapid exchange port is located proximal to the enclosure member and is configured to receive a guidewire therethrough.

29. The IVL catheter of claim 21, wherein the tube extender is fixed to the distal region of the catheter shaft.

30. The IVL catheter of claim 21, wherein the skived portion comprises a first angled segment in which a circumferential extent of the radially discontinuous hypotube wall reduces distally along an axial length of the hypotube.

31. The IVL catheter of claim 30, wherein the skived portion comprises an axial segment in which the circumferential extent of the radially discontinuous hypotube wall remains substantially constant distally along the axial length of the hypotube.

32. The IVL catheter of claim 31, wherein the skived portion comprises a second angled segment in which the circumferential extent of the radially discontinuous hypotube wall reduces distally along the axial length of the hypotube.

33. The IVL catheter of claim 32, wherein the axial segment is arranged distal to the first angled segment and proximal to the second angled segment.Docket No. 23812.33.1a 5634. The IVL catheter of claim 21, wherein a hypotube wall of the hypotube comprises an outer tube surface that defines one or more grooves extending axially along the hypotube.

35. The IVL catheter of claim 34, wherein a groove of the one or more grooves receives at least part of the tube extender to attach the tube extender to the hypotube.

36. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising: a hypotube comprising a proximal section and a distal section, the proximal section defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, the distal section defining a skived portion comprising a radially discontinuous hypotube wall, wherein the distal section of the hypotube extends to and is fixed to a distal region of the catheter shaft; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy, wherein the distal region of the catheter shaft is distal to the one or more emitters; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.

37. The IVL catheter of claim 36, wherein the skived portion is radially spaced from the one or more emitters.

38. The IVL catheter of claim 37, wherein the one or more emitters define at least one spark gap, and wherein the skived portion is radially spaced from the one or more emitters by a distance greater than a width of the at least one spark gap.

39. The IVL catheter of claim 38, wherein the skived portion is radially spaced from the one or more emitters by a distance in a range of about 0.003 inches to about 0.02 inches.

40. An IVL catheter, comprising: a catheter shaft configured for navigation through vasculature of a subject, the catheter shaft comprising:Docket No. 23812.33.1a 57a hypotube defining a first fluid lumen, the first fluid lumen being in fluid communication with a second fluid lumen defined by the catheter shaft, wherein a hypotube wall of the hypotube comprises an outer tube surface that defines one or more grooves extending axially along the hypotube; one or more emitters connected to the catheter shaft, the one or more emitters being configured for generating pressure waves within the vasculature of the subject to facilitate IVL therapy; and an enclosure member connected to the catheter shaft, wherein the one or more emitters are disposed within the enclosure member, wherein an interior of the enclosure member is in fluid communication with the second fluid lumen of the catheter shaft to facilitate fluid insertion and / or fluid withdrawal for the enclosure member.Docket No. 23812.33.1a 58

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