Intravascular lithotripsy

Abstract

To provide a medical device which executes treatment on a calcification plaque lesion in a blood circulatory system of a patient.SOLUTION: The medical device may comprise an elongate body, a balloon positioned at a distal portion of the elongate body, and one or more pressure wave emitters positioned along a central longitudinal axis of the elongate body within the balloon. The one or more pressure wave emitters may be configured to propagate pressure waves radially outward through a fluid to break up calcified lesions at a target treatment site. At least one of the one or more pressure wave emitters may comprise an electron emitter comprising a first electrode and a second electrode. The first electrode and the second electrode may be arranged to define a spark gap between the first electrode and the second electrode, and the second electrode may comprise a part of a hypotube.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to treatments for calcified plaque lesions in a patient's vasculature. [Background technology]

[0002] During an intravascular lithotripsy (IVL) procedure, and more particularly during an electrohydraulic lithotripsy (EHL) procedure, a clinician uses a catheter configured to emit high-energy pressure waves to disrupt calcified plaque lesions within a patient's vasculature. Summary of the Invention

[0003] The present disclosure describes systems and techniques for creating and directing high-energy intravascular pressure waves for the fracturing and / or collapse of calcified lesions within a patient's vasculature. For convenience, the techniques herein are primarily described with respect to electrical-based systems and their respective applications, such as peripheral vascular applications. However, except as expressly noted below, it will be understood that the techniques described herein may be considered equally applicable to similar systems based on other forms of energy, such as optical (e.g., laser)-based systems, and their respective applications, such as coronary artery treatment applications.

[0004] Generally, the systems described herein include an energy generator detachably coupled to a catheter having an array of pressure wave emitters dispersed within an interventional balloon. During a lesion collapse procedure, a clinician may advance the interventional balloon to a target treatment site within a patient's vasculature and inflate the balloon with an inflation fluid, such as a saline / contrast fluid mixture, until the balloon contacts at least a portion of the local vessel wall. The clinician then activates the energy generator, generating cavitation bubbles within the fluid-filled balloon in the catheter, which propagates high-energy pressure waves through the balloon and the calcified lesion. Subsequent collapse of the fluid cavitation may also result in secondary pressure waves, further destabilizing the internal structure of the lesion.

[0005] In some examples, the medical device comprises an elongate body; a balloon positioned at a distal portion of the elongate body, the balloon configured to receive a fluid and thereby expand such that the outer surface of the balloon contacts the inner surface of a target treatment site within the patient's vasculature; and one or more pressure wave emitters positioned within the balloon along a central longitudinal axis of the elongate body, the one or more pressure wave emitters configured to propagate pressure waves radially outward through the fluid to disrupt calcified lesions at the target treatment site, at least one of the one or more pressure wave emitters comprising an electron emitter comprising a first electrode and a second electrode, the first electrode and the second electrode being arranged to define a spark gap between the first electrode and the second electrode, the second electrode comprising a portion of a hypotube.

[0006] In some examples, the first electrode and the second electrode are embedded in an adhesive layer, and the electron emitter further comprises an elastomer tube radially disposed between the elongated body and the second electrode, hi some examples, the electron emitter further comprises a coil layer radially disposed between the elongated body and the elastomer tube.

[0007] In some examples, the first electrode is oriented such that an outer surface is non-parallel to the central longitudinal axis of the elongate body in the absence of an external force, and in some examples, the first electrode is configured to move relative to the elongate body such that the outer surface of the first electrode is oriented parallel to the central longitudinal axis during insertion and withdrawal of the medical device through the patient's vasculature.

[0008] In some examples, the spark gap comprises a first spark gap, and the electron emitter further comprises a third electrode, the third electrode positioned to define a second spark gap between the second electrode and the third electrode. In some examples, the first electrode, the second electrode, and the third electrode are all portions of a common cylindrical surface of the hypotube. In some examples, the first electrode and the third electrode both define a rounded triangular shape, and the second electrode defines a parallelogram shape. In some examples, the first electrode, the second electrode, and the third electrode all define a parallelogram shape.

[0009] In some examples, the first electrode, the second electrode, and the third electrode all define a rounded rectangular shape. In some examples, the first electrode and the third electrode both define an elliptical shape, and the second electrode defines a semi-cylindrical shape. In some examples, the electron emitter further comprises a coupler layer positioned radially between the elongated body and the second electrode. In some examples, the coupler layer comprises polyimide.

[0010] In some examples, the electron emitter is wired such that the first electrode and the third electrode are independently operable, hi some examples, the first electrode is ring-shaped, the second electrode is disk-shaped, and the first electrode is positioned around the second electrode.

[0011] In some examples, the electron emitter further comprises a third electrode and a fourth electrode, wherein the third electrode is ring-shaped, the fourth electrode is disk-shaped, the third electrode is positioned around the fourth electrode, and the first electrode, second electrode, third electrode, and fourth electrode are all portions of a common cylindrical surface of the hypotube.

[0012] In some examples, the first electrode defines an inner radius of about 0.008 inches and an outer radius of about 0.0210 inches. In some examples, the hypotube defines a longitudinal length of about 0.080 inches to about 0.090 inches and an outer circumference of about 0.10 inches to about 0.12 inches. In some examples, the hypotube defines an inner diameter of about 0.029 inches and an outer diameter of about 0.034 inches. In some examples, the first electrode is rectangular shaped, and the first electrode extends at least partially radially inward through the outer surface of the elongated body.

[0013] In some examples, the first electrode extends radially inward through the elongate body and at least partially radially inward into the inner lumen of the elongate body. In some examples, the one or more pressure wave emitters include five electron emitters longitudinally spaced along the central longitudinal axis of the elongate body.

[0014] In some examples, an intravascular lithotripsy (IVL) system comprises an energy generator and a catheter, as referenced above.

[0015] In some examples, the energy generator is configured to control a treatment cycle by causing the electron emitter to transmit a plurality of pressure wave pulses, the plurality of pressure wave pulses including about 80 pulses to about 300 pulses.

[0016] In some examples, a method of forming an electronic pressure wave emitter for an intravascular lithotripsy (IVL) catheter comprises laser cutting a hypotube to define at least a first electrode and a second electrode positioned to define a spark gap therebetween, inserting an elongate body through the laser cut hypotube, flowing a potting material around the laser cut hypotube, and removing obsolete support structures from the hypotube.

[0017] In some examples, the spark gap comprises a first spark gap, and laser cutting the hypotube further comprises laser cutting the hypotube to define a third electrode positioned to define a second spark gap between the second electrode and the third electrode.

[0018] In some examples, laser cutting the hypotube comprises laser cutting the hypotube so that the first electrode and the third electrode both define a rounded triangular shape and the second electrode defines a parallelogram shape. In some examples, laser cutting the hypotube comprises laser cutting the hypotube so that the first electrode, the second electrode, and the third electrode all define a parallelogram shape.

[0019] In some examples, laser cutting the hypotube comprises laser cutting the hypotube so that the first electrode, the second electrode, and the third electrode all define a rounded rectangular shape. In some examples, laser cutting the hypotube comprises laser cutting the hypotube so that the first electrode and the third electrode both define an oval shape and the second electrode defines a semi-cylindrical shape. In some examples, the method further comprises wiring the first electrode and the third electrode to be independently operable.

[0020] In some examples, the spark gap comprises a first spark gap, and laser cutting the hypotube further comprises laser cutting the hypotube to define the third electrode and the fourth electrode, the third electrode and the fourth electrode being positioned to define a second spark gap between them. In some examples, laser cutting the hypotube further comprises laser cutting the hypotube such that the first electrode and the third electrode are ring-shaped, the second electrode and the fourth electrode are disk-shaped, the first electrode is positioned around the second electrode, and the third electrode is positioned around the fourth electrode.

[0021] In some examples, the medical device comprises an elongate body; a balloon positioned at a distal portion of the elongate body, the balloon configured to receive a fluid and thereby expand such that the outer surface of the balloon contacts the inner surface of a target treatment site within a patient's vasculature; and one or more pressure wave emitters positioned within the balloon along a central longitudinal axis of the elongate body, the one or more pressure wave emitters configured to propagate pressure waves radially outward through the fluid to disrupt calcified lesions at the target treatment site, at least one of the one or more pressure wave emitters comprising an electron emitter including a first electrode, a second electrode, and a third electrode arranged to define a first spark gap between the first electrode and a second electrode and a second spark gap between the second electrode and a third electrode, the first electrode, the second electrode, and the third electrode being part of a common hypotube.

[0022] In some examples, the medical device comprises a plurality of conductive wires configured to provide electrical energy to the emitter array and arranged according to a wiring topology.

[0023] In some examples, the plurality of conductive wires extend generally parallel to the central longitudinal axis. In some examples, the wiring configuration comprises a single coil configuration such that the plurality of conductive wires are wound helically around the elongate body, with adjacent coil turns of the plurality of conductive wires spaced longitudinally along the central longitudinal axis. In some examples, the wiring configuration comprises a double coil configuration such that the plurality of conductive wires are wound helically around the elongate body, with adjacent pairs of coil turns of the plurality of conductive wires spaced longitudinally along the central longitudinal axis. In some examples, the wiring configuration comprises a quadruple coil configuration such that the plurality of conductive wires are wound helically around the elongate body, with adjacent pairs of coil turns of the plurality of conductive wires spaced longitudinally along the central longitudinal axis.

[0024] In some examples, the plurality of conductive wires comprises a plurality of flat wires. In some examples, the plurality of conductive wires comprises a plurality of round wires having a flattened portion along the emitter array.

[0025] In some examples, the elongate body comprises an inner body and an outer body, the outer body comprising an inner layer and an outer layer, and the plurality of conductive wires are helically wound around the outer surface of the inner layer. In some examples, the outer layer of the outer body spans the plurality of conductive wires such that the plurality of conductive wires are embedded within the outer layer. In some examples, the outer layer comprises a potting layer or heat shrink tubing. In some examples, the outer layer terminates proximally from the inner layer such that distal portions of the plurality of conductive wires are exposed inside the balloon.

[0026] In some examples, the elongated body comprises an inner body and an outer body, and the plurality of conductive wires are wound helically around the outer surface of the inner body such that the plurality of conductive wires form a reinforcing layer for the elongated body.

[0027] In some examples, each of the plurality of emitters includes a respective voltage wire such that each of the plurality of emitters is independently actuable. In some examples, the outer surface of the balloon includes a polymer coating. In some examples, the outer surface of the balloon includes a pharmaceutical-based coating, such as a hydrophilic coating, an anti-thrombogenic coating, or an anti-proliferative drug.

[0028] In some examples, the balloon comprises two or more nested expandable substrates. In some examples, the two or more nested expandable substrates include at least an outer layer and an inner layer, the inner surface of the outer layer being bonded to the outer surface of the inner layer to form a single multi-layer extrusion. In some examples, the inner layer comprises a high-pressure-retaining layer and the outer layer comprises a urethane layer.

[0029] In some examples, the balloon further comprises a reinforcing structure, in some examples, the reinforcing structure comprises a plurality of longitudinal fibers aligned parallel to the longitudinal axis of the balloon and a plurality of braided fibers, in some examples, the plurality of longitudinal fibers comprises 4 to 8 longitudinal fibers.

[0030] In some examples, the balloon comprises an outer layer, an inner layer nested within the outer layer, and a cage structure nested between the outer layer and the inner layer, the cage structure comprising one or more longitudinal members oriented parallel to the longitudinal axis and one or more circumferential elements oriented perpendicular to the longitudinal axis.

[0031] In some examples, the medical device further comprises a cage structure at least partially surrounding the outer surface of the balloon. In some examples, the cage structure is securely coupled to the outer surface of the balloon. In some examples, the cage structure comprises nitinol braid, metal wire, printed metal, radiopaque metal wire, or radiopaque printed metal. In some examples, the balloon comprises a porous membrane configured to infuse a medicinal agent into the target treatment site.

[0032] In some examples, the balloon comprises a plurality of longitudinal ribs configured to define fold guides as the balloon folds radially inward. In some examples, the plurality of longitudinal ribs comprises an odd number of ribs. In some examples, the medical device comprises a spring configured to longitudinally stretch the balloon in the absence of an external force.

[0033] In some examples, the medical device includes a fracturing member positioned on an outer surface of the balloon. In some examples, the fracturing member includes a conductive wire extending along the longitudinal axis of the balloon and a plurality of piezoelectric elements positioned along the conductive wire and configured to radiate additional pressure waves against the calcified lesion. In some examples, the medical device includes a protection device positioned at the distal portion of the elongate body and configured to at least partially occlude the target treatment site and collect portions of the lesion.

[0034] In some examples, the medical device comprises a protection device positioned along the elongate body proximal to the balloon and configured to at least partially occlude the target treatment site and collect a lesion.

[0035] In some examples, the elongate body defines a lumen configured to receive a 0.0104 inch to 0.035 inch guidewire. In some examples, the medical device comprises a handle positioned at a proximal end of the elongate body and comprising an internal power source for the emitter array. In some examples, the medical device comprises a scoring element configured to contact and abrade the calcified lesion. In some examples, the scoring element defines a serrated outer surface.

[0036] In some examples, the medical device comprises a means for controlling a primary direction of emission of the pressure waves. In some examples, the medical device comprises a waveguide pressed against the inner surface of the balloon, positioned along only a portion of the circumference of the balloon, and configured to absorb or reflect the pressure waves from a second portion of the circumference of the balloon. In some examples, the medical device comprises ceramic, porcelain, diamond, polyimide, or polyetheretherketone (PEEK). In some examples, the waveguide defines a reflective or absorbing fluid pocket.

[0037] In some examples, the medical device includes a radiopaque indicator positioned along a first portion of the circumference of the balloon and configured to indicate the direction of the pressure wave emission. In some examples, the radiopaque indicator includes a radiopaque wire positioned along the outer surface of the balloon. In some examples, the radiopaque indicator includes a conductive wire of a spallation element positioned along the outer surface of the balloon, the spallation element further including a plurality of piezoelectric elements configured to emit additional pressure waves through the calcified lesion.

[0038] In some examples, each of the one or more shock wave emitters defines a respective orientation, and the medical device further comprises a user input mechanism for modifying the respective orientation of the one or more shock wave emitters. In some examples, each of the one or more shock wave emitters defines a respective fixed orientation, and the medical device further comprises a user input mechanism configured to independently activate a first subset of the one or more shock wave emitters separately from a second subset of the one or more shock wave emitters. In some examples, the balloon comprises two or more elongated sub-balloons circumferentially oriented around the central longitudinal axis, each sub-balloon including a respective subset of the one or more shock wave emitters.

[0039] In some examples, the system further includes a sensor configured to generate sensor data indicative of at least one parameter. In such examples, the energy generator is configured to vary the amount of energy delivered based on the sensor data. In some examples, to vary the amount of energy, the energy generator is configured to vary a current level, a voltage level, a pulse duration, a pulse frequency, or a light intensity. In some examples, the sensor data includes fluid pressure data, fluid velocity data, or temperature data. In some examples, the sensor includes an electrical impedance monitor, an inflation fluid flow rate monitor, an inflation fluid pressure monitor, a vessel wall surface monitor, a vessel diameter monitor, an interventional balloon diameter monitor, or a plaque disruption monitor. In some examples, the sensor includes a resonant frequency sensor, and the electrical energy monitor is configured to vary the pressure wave frequency to approach the resonant frequency of the calcified lesion. In some examples, the energy generator is configured to terminate the applied voltage based on the sensor data. [Brief explanation of the drawings]

[0040] Features, aspects, and advantages will now be described with reference to the drawings, which are intended to be illustrative of the present invention and not limiting, in which like reference characters indicate corresponding features consistently among like examples. [Figure 1] 1 is a schematic diagram of an example intravascular lithotripsy (IVL) system comprising an energy generator and a catheter with a pressure wave emitter array within an interventional balloon. [Figure 2] FIG. 2 is a conceptual block diagram illustrating some example components of the energy generator of FIG. 1. [Figure 3] FIG. 2 is a conceptual diagram illustrating some example components of the catheter of FIG. 1. [Figure 4A] FIG. 2 is a perspective view of a first example of an emitter assembly for the catheter of FIG. 1. [Figure 4B] FIG. 4B is a cross-sectional view of the emitter assembly of FIG. 4A. [Figure 5A]FIG. 2 is a perspective view of a second example of an emitter assembly for the catheter of FIG. 1. [Figure 5B] FIG. 5B is a cross-sectional view of the emitter assembly of FIG. 5A. [Figure 6A] 10 shows a third example of an emitter assembly for the catheter of FIG. 1. [Figure 6B] FIG. 6B is a cross-sectional view of the emitter assembly of FIG. 6A. [Figure 6C] FIG. 6B is a cross-sectional view of the emitter assembly of FIG. 6A with the potting material layer removed to illustrate the components embedded therein. [Figure 7A] 10 is a 2D representation of a first example laser cut hypotube design for an emitter assembly defining a non-orthogonal spark gap orientation. [Figure 7B] 7B is a 3D representation of the first example hypotube design of FIG. 7A. [Figure 8A] 10 is a 2D representation of a second example laser cut hypotube design for an emitter assembly defining an orthogonal spark gap orientation. [Figure 8B] 8B is a 2D representation of a laser cut hypotube array comprising the second example hypotube design of FIG. 8A. [Figure 9] 10 is a 2D representation of a third example laser cut hypotube design for an emitter assembly defining an annular spark gap configuration. [Figure 10] 1 is a flowchart illustrating an example technique for forming an emitter assembly for an IVL catheter. [Figure 11] 1 illustrates an example flex circuit for an emitter assembly of an IVL catheter. [Figure 12] 11A and 11B show two wiring examples for the flex circuit. [Figure 13] Two example wiring configurations are shown for conductively wiring an array of electron pressure wave emitters. [Figure 14] 2A-2C are conceptual cross-sectional views illustrating four example wiring configurations for the electron emitter array of the catheter of FIG. 1. [Figure 15A]FIG. 1 is a conceptual diagram illustrating an example wiring configuration for an electron emitter array having four emitter units. [Figure 15B] FIG. 1 is a conceptual diagram illustrating an example wiring configuration for an electron emitter array having five emitter units. [Figure 16A] FIG. 1 is a conceptual diagram showing a first example of a wiring configuration. [Figure 16B] FIG. 10 is a conceptual diagram showing a second example of a wiring configuration. [Figure 17A] FIG. 1 is a conceptual diagram illustrating an example IVL device having an optical-based emitter array. [Figure 17B] FIG. 17B is a cross-sectional view through the IVL device of FIG. 17A. [Figure 18] 1A-1C are cross-sectional views of example IVL devices having multi-layered interventional balloons. [Figure 19] 1 shows an example IVL device having an interventional balloon with a protective structure. [Figure 20] 1 shows an example IVL device having an interventional balloon with a protective structure. [Figure 21] 1 shows an example IVL device having a pair of scoring members. [Figure 22] 1 shows an example IVL device with a fracturing element. [Figure 23] 1 shows an example of an IVL device with a spring mechanism. [Figure 24] 1 illustrates an example IVL device having a distal protection member. [Figure 25] 2 illustrates the IVL system of FIG. 1 with an example closed-loop energy delivery feedback mechanism. [Figure 26] 2 shows an example handle for the IVL catheter of FIG. 1. [Figure 27] FIG. 1 is a cross-sectional view through a first example of a focused IVL device. [Figure 28A] FIG. 1 is a perspective view of a second example of a focused IVL device. [Figure 28B] FIG. 10 is a cross-sectional view of a second example of a focused IVL device. [Figure 29A] FIG. 10 is a perspective view of a third example of a focused IVL device. [Figure 29B] FIG. 10 is a cross-sectional view of a third example of a directional focusing IVL device. DETAILED DESCRIPTION OF THE INVENTION

[0041] Although specific examples are disclosed below, the subject matter of the invention extends beyond the specifically disclosed examples to other alternative examples and / or uses, as well as to modifications and equivalents thereof. Thus, the scope of the claims appended hereto is not limited to any of the specific examples described below. For example, in any method or process disclosed herein, the acts or tasks of the method or process may be performed in any suitable order and are not necessarily limited to any particular disclosed order. Various tasks may be described as multiple, sequential, discrete tasks, which may be helpful in understanding particular examples, but the order of description should not be construed to imply that these tasks are order dependent. Furthermore, the structures, systems, and / or devices described herein may be embodied as integrated or separate components.

[0042] For purposes of comparing various examples, certain aspects and advantages of these examples are described. Not all such aspects and advantages may necessarily be achieved by any particular example. Thus, for example, various examples may be implemented to achieve or optimize one advantage or collection of advantages as taught herein, but not necessarily achieve other aspects and advantages that may be further taught or suggested herein.

[0043] During an intravascular lithotripsy (IVL) procedure, and more particularly, during an electrohydraulic lithotripsy (EHL) procedure, clinicians use high-energy pressure waves to disrupt calcified plaque lesions within a patient's vasculature. Typical IVL systems suffer from a number of disadvantages that limit the effectiveness of the procedure. For example, IVL catheters typically emit pressure waves that propagate around the entire inner circumference of the vessel wall at the target treatment site. In cases where the calcified lesion is confined to only a portion of the circumference of the vessel wall, e.g., in the case of eccentric, focal, and / or nodular lesions, pressure waves propagating in all directions may result in ineffective disruption or waste of applied energy. As a second example, in addition to directional limitations, typical IVL catheters are designed to deliver a constant level of energy and / or power, presenting a similar set of challenges and / or effectiveness limitations regardless of the specific clinical need (e.g., lesion size and / or density) at the target treatment site.

[0044] As a third example, many IVL catheter designs include a distal interventional balloon to distribute pressure waves across surrounding tissue. In some cases, these interventional balloons may rupture in response to above-threshold wave pressures or when treating severely calcified lesions. If the balloon ruptures along its entire circumference, for example, by removing the outer sheath or other introducer to remove the balloon catheter, the distal portion of the balloon may “bundle” around the distal catheter tip, making withdrawal from the patient more difficult and / or complicated. As a final example, certain features of typical interventional balloons may increase resistance to inserting the catheter into the introducer sheath early in the procedure and / or withdrawing the catheter through the introducer sheath at the end of the procedure. For example, bulky balloon “cones” and ineffective balloon “pleat” rewrapping may require the clinician to apply excessive force to successfully perform the IVL procedure.

[0045] The present disclosure describes systems and techniques for creating and directing high-energy intravascular pressure waves for the fracturing and / or collapse of calcified lesions within a patient's vasculature. For convenience, the techniques herein are described primarily with respect to electrical-based systems and their respective applications, such as peripheral vascular applications. However, except as expressly noted below, it will be understood that the techniques described herein may be considered equally applicable to similar systems based on other forms of energy, such as optical (e.g., laser)-based systems, and their respective applications, such as coronary artery treatment applications.

[0046] Generally, the systems described herein include an energy source and an IVL catheter with a distal IVL device that includes an interventional balloon and a pressure wave emitter array. During a lesion disruption procedure, a clinician may advance the interventional balloon to a target treatment site within a patient's vasculature and inflate the balloon with an inflation fluid, such as a saline / contrast fluid mixture, until the balloon contacts at least a portion of the local vessel wall. When the clinician then activates an energy generator, the catheter generates cavitation bubbles within the fluid-filled balloon, causing high-energy pressure waves to propagate through the balloon and the calcified lesion. Subsequent collapse of the fluid cavitation can also result in secondary pressure waves, further destabilizing the internal structure of the lesion.

[0047] FIG. 1 is a conceptual diagram illustrating an example IVL system 100. As shown in FIG. 1, the IVL system 100 includes at least an energy generator 102 and an IVL catheter 104 detachably coupled to the energy generator 102, e.g., via a catheter connector interface 204. In some examples, a detachable cable 118 may be connected between the generator 102 and the catheter 104 to provide energy to the catheter 104. As described in further detail below, an energy source (e.g., a battery, a capacitor, etc.) may additionally or alternatively be integrated into the catheter 104. The catheter 102 includes an elongate body 106 and an IVL device 108 located at a distal portion of the elongate body 106. The elongate body 106 is configured to navigate a patient's tortuous vasculature toward a target treatment site, e.g., a calcified plaque lesion within a blood vessel.

[0048] As shown in FIG. 1 , the IVL device 108 includes a fluid-inflatable interventional balloon 110 and a pressure wave emitter array 112 positioned within the balloon 110. The emitter array 112 includes one or more individual emitter units 114A-114E. For example, the interventional balloon 110 or a distal portion of the elongate body 106 passing through the interventional balloon 110 may define a central longitudinal axis 116, and the emitter units 114A-114E may be longitudinally distributed along the central longitudinal axis 116. The individual emitter units 114A-114E are referred to throughout this disclosure as "emitter assemblies" (e.g., in reference to the particular arrangement of subcomponents that collectively form the emitter unit) as well as "emitters" (e.g., in reference to the emitter unit as a whole).

[0049] 1 includes a first emitter unit 114A, a second emitter unit 114B, a third emitter unit 114C, a fourth emitter unit 114D, and a fifth emitter unit 114E. While five emitter units 114 are shown in FIG. 1, the emitter array 112 of the IVL device 108 may include as few as one emitter unit or as many emitter units as can reasonably fit within the balloon 110. Each of the emitter units 114 is configured to receive energy from the energy generator 102 and use the received energy to generate and transmit high-energy pressure waves through the balloon 110 and across the target treatment site. As described in further detail below, the energy generator 102 may generate and transmit energy in the form of electrical energy, light energy, or a combination thereof. For example, the emitter unit 114 may use the received energy to generate cavitation in the fluid within the balloon 110, causing one or more high-energy pressure waves to propagate radially outward through the balloon 110 and the calcified lesion. In some, but not all, cases, the collapse of the fluid cavitation may result in a subsequent series of secondary high-energy pressure waves, further destabilizing the internal structure of the calcified plaque lesion. In some examples, the one or more emitters 114 may comprise an electrically-based emitter configured to receive electrical energy from the generator 102, e.g., via one or more conductive wires, to generate a spark between a pair of electrodes, thereby initiating incipient cavitation. Additionally or alternatively, the one or more emitters 114 may comprise an optically-based emitter configured to receive a high-energy optical (e.g., light) signal from the generator 102, e.g., via one or more fiber optic wires or tubes, and direct the optical signal to initiate incipient cavitation.

[0050] Figure 2 is a block diagram illustrating some example components of the energy generator 102 of Figure 1. A power input 202 (e.g., for conductively coupling to a wall port or other power source) connects to a power module 224 and an internal power source 208. As shown in Figure 2, the power module 224 can include, by way of various non-limiting examples, a high-voltage DC-DC converter 210, a high-voltage capacitor and transistor switch 212, a voltage and / or current measurement unit 216, and a device identification unit 222 configured to determine whether the catheter 104 is an approved device while the catheter 104 is connected via the catheter connector 204. For example, the energy generator 102 may be configured to disable energy output to the catheter connector 204 if an unrecognized device is connected.

[0051] The generator 102 may include memory and one or more processors, such as the processor 218 and / or a user interface control processor 226. The UI control processor 226 is configured to provide functionality for a user interface 234 of the energy generator 102, such as a display screen, touch screen, buttons, or other manual controls that allow a user (e.g., a clinician) to operate the energy generator 102.

[0052] 2, in addition to or alternatively to electrical energy-based components, in some examples, the energy generator 102 may include an optical signaling unit configured to convert electrical power (e.g., from the power input 202) into a beam of light, such as a laser beam. The optical signaling unit may then direct an optical signal to a transmission cable, such as an optical fiber, that is either coupled to or integrated as part of the catheter 104 (FIG. 1).

[0053] FIG. 3 is a conceptual diagram illustrating some example components of the catheter 104 of FIG. 1. As shown in FIG. 3, the catheter 104 includes a proximal section 302 and a distal section 304 opposite the proximal section. The proximal section 302 may include a catheter hub 306 and / or a handle (discussed in more detail below). The catheter hub 306 defines an access port 308, an inflation port 310, and a power port 312. The access port 308 allows a clinician to manipulate (e.g., navigate, actuate, etc.) the distal section 304, which includes the IVL device 108. A clinician may use the inflation port 310 to inject an inflation fluid, such as a saline / contrast fluid solution, to inflate the interventional balloon 110 to an expanded or inflated state in which the outer surface of the balloon 110 contacts the inner surface of the blood vessel wall at the intended treatment site. The power port 312 is configured to interconnect with a power cable (not shown) to conductively couple the catheter 104 to the energy generator 102 (FIGS. 1 and 2). The catheter hub 306 may also include a strain relief 314 to stiffen the elongate body 106 and reduce kinking.

[0054] 3 , in some, but not all, examples, the elongate body 106 may comprise an outer elongate structure 316 and an inner elongate structure 318. For example, the outer elongate structure 316 may comprise a sheath or outer catheter defining an inflation lumen 320. In some examples, the outer elongate structure 316 forms a proximal extension of the interventional balloon 110 such that the inflation lumen 320 fluidly connects the inflation port 310 to the interior cavity of the interventional balloon 110.

[0055] The inner elongate structure 318 may comprise an inner catheter or other inner structure positioned within an inflation lumen 320 configured to retain the emitters 114 of the emitter array 112. In such an example, the inner elongate structure 318 may itself define an inner lumen 322 configured to receive a guidewire, for example, via a distal port 324. In other examples, as depicted in subsequent figures, the elongate body 106 comprises only a single layer defining a single inner lumen.

[0056] As described above, the catheter 104 is configured to be advanced through the patient's vasculature (e.g., through an arteriotomy) to position the balloon 110 adjacent to a calcium lesion located at a target treatment site. The IVL device 108 may be configured to generate a first pressure wave (or wave cluster) by expanding a liquid volume resulting from a phase transition from liquid to liquid vapor, which may cause gas bubbles to rapidly expand. A second pressure wave may be generated as gas bubbles, which then collapse. In some examples, the balloon 110 has an outer coating 326, e.g., made of a polymer and / or other material, as described in further detail below. For example, the outer coating 326 may include a hydrophilic coating to improve navigability through the patient's vasculature. Additionally or alternatively, the outer coating 326 may include a pharmaceutical coating, such as an antithrombotic or antiproliferative drug, as well as excipients to aid in drug delivery. As described in more detail below, the balloon 110 may be permeable / semi-permeable (e.g., a "weeping" balloon) or permeable / semi-permeable for injecting drugs into the blood vessel as compared to injecting drugs into the blood vessel through the lumen.

[0057] FIG. 4A is a perspective view of a first example of an emitter assembly 400 (e.g., emitter assembly 114A of FIG. 1) of the catheter 104 of FIG. 1, and FIG. 4B is a cross-sectional view of the emitter 400 of FIG. 4A. In particular, FIGS. 4A and 4B show the electron emitter 400 including a pair of conductive electrodes 402A, 402B defining a first spark gap 404A therebetween. In this example, the electrodes 402A, 402B are configured to receive electrical energy (e.g., current) from the energy generator 102 (FIGS. 1 and 2) via conductive wires 406A, 406B. The resulting spark across the spark gap 404 is configured to create a cavity in the surrounding inflation fluid 408 and propagate a high-energy pressure wave through the inflation fluid 408.

[0058] In accordance with the techniques of the present disclosure, one or both electrodes 402A, 402B are subsections or portions of the cylindrical surface of a common hypotube 410. As used herein, "hypotube" refers to a metal tube with micro-engineered features along its length.

[0059] That is, a specific section of the cylindrical hypotube 410 may be removed (e.g., laser cut) to form one or both electrodes 402A, 402B and the spark gap 404A therebetween. In such an example, a potting material 412, such as an adhesive layer, is poured over the remaining portions of the cylindrical hypotube (e.g., electrodes 402A, 402B) and either cured or allowed to harden to hold the hypotube sections in place. Examples of potting material 412 include polyurethane-based, acrylic-based, silicone-based, or other suitable materials with sufficient voltage resistance. In some, but not all, examples, excess potting material 412 may then be removed (e.g., cut, removed, or scraped) from between electrodes 402A, 402B to reconstruct the spark gap 404A, if necessary.

[0060] As further shown in FIG. 4B , the hypotube 410 of the emitter assembly 400 includes two pairs of conductive electrodes and respective spark gaps therebetween: a first pair of electrodes 402A, 402B (and spark gap 404A therebetween) and a second pair of electrodes 402B, 402C (and spark gap 404B therebetween). That is, electrode 402B may be used as a common electrode for both electrodes 402A, 402C, aligned with opposite edges of electrode 402B. Specifically, a first edge 414A of the first electrode 402A is aligned with a second edge 414B of the second electrode 402B to define the first spark gap 404A. Furthermore, a third edge 414C of the second electrode 402B is aligned with a fourth edge 414D of the third electrode 402C to define the second spark gap 404B. In some instances, the two pairs of conductive electrodes may be wired to be simultaneously operable, while in other instances, as further detailed below, they may be wired to be separately operable. Such wiring configurations allow the clinician to select which emitter assembly, and even which specific electrode pair, is activated for treatment of a calcified plaque lesion. While a two-electrode pair system is primarily shown and described herein, it should be noted that a greater number of electrode pairs may be incorporated into the emitter assembly 400.

[0061] In some examples, rather than two emitter electrode pairs, the hypotube 410 may similarly define a three-electrode system, where the three electrodes may consist of a working electrode, a counter electrode, and a reference electrode. For example, the working and counter electrodes are configured to generate pressure waves, while the role of the reference electrode is to act as a reference for measuring and controlling the working electrode potential without passing any current itself.

[0062] As further shown in FIG. 4B , the electron emitter assembly 400 includes multiple nested layers (e.g., to define the elongated body 106 therein). For example, within the hypotube 410 and potting material 412, the emitter assembly 400 includes an elastomeric layer 416, such as a thermoplastic elastomer. One such example includes a polyether block amide (e.g., PEBAX® from Arkema, Colombes, France). In some, but not all, examples, within the elastomeric layer 416, the emitter assembly 400 may include a coil 418, such as a coiled winding of the conductive wire 408 or a coil of a spring associated with the interventional balloon 110 ( FIG. 1 ), as described in further detail below with respect to FIG. 23 . Finally, the innermost layer of the emitter assembly 400 is a secondary polymer layer 420, such as a polyimide. The polymer layer 420 may be tubular, defining a portion of the guidewire lumen 322 therein.

[0063] According to some examples, the emitter assembly 400 is configured to implement a relatively high redundant voltage. Therefore, materials of construction should be selected for low degradation so that the IVL device 108 will last the duration of the IVL procedure. In some examples, the catheter 104 is configured for disposable use only, while the energy generator 102 is theoretically considered to be infinitely reusable. In some examples, the number of pressure wave "cycles" in an IVL procedure may range from about 80 pulse waves to about 300 pulse waves, although the treatment may include more or fewer pulse waves depending on the specific clinical parameters presented.

[0064] In some examples, the electrode pairs 402A / 402B and 402B / 402C may be made from narrow copper strips fixed on the inner elongate structure 318 inside the interventional balloon 110 (FIGS. 1 and 3). In some, but not all, examples, each electrode 402 may be cut, bent, or otherwise formed to define an angle relative to the central longitudinal axis 116. That is, the electrodes 402 may be configured to "lean" away from the central longitudinal axis 116 in the absence of an external force. During delivery through the patient's vasculature, the radially inward compressive force from the deflated balloon 110 may cause the electrodes to "flatten" toward the central longitudinal axis 116.

[0065] Figure 5A is a perspective view of a second example of an electron emitter assembly 500 for the catheter 104 of Figure 1, and Figure 5B is a cross-sectional view of the emitter assembly 500 of Figure 5A. Specifically, the example emitter assembly 500 of Figures 5A and 5B includes two laser-cut "emitter" electrodes 502A, 502C welded to a laser-cut polyimide "coupler" layer 504. In this example, the emitter electrodes 502A, 502C are shown as generally elliptical, although other geometric shapes are contemplated.

[0066] A laser-cut "hypotube" electrode 502B is also attached to the coupler layer 504 between the emitter electrodes 502A and 502C to define respective spark gaps 508A, 508B. In this example, the hypotube electrode 502B is shown as generally semi-cylindrical, although other geometries are contemplated. A series of flat wires 406A-406D may be utilized to deliver energy from the energy generator 102 (FIGS. 1 and 2) to the emitter electrodes 502A and 502C, from the emitter electrodes 502A, 502C to additional emitter units 114 (FIG. 1) within the IVL device 108, and from the additional emitter units 114 back to ground.

[0067] As shown in FIGS. 5A and 5B, in this example, a polyimide inner elongated structure 506 extends distally through the core of the emitter assembly 500, as can be seen on the outside of the assembly in FIG. 5A or in the innermost circle in FIG. 5B. Part of the outermost concentric ring above the central longitudinal axis 116 is a laser-cut hypotube electrode 502B that passes energy to mirrored "emitter" electrodes 502A, 502C on the opposite side. Part of the outermost concentric ring below the central longitudinal axis 116 is another emitter electrode 502C welded to wire 406D. Continuing away from the emitter assemblies on either side are additional flat wires 406 around the longitudinal axis 116 that carry the energy to generate the pressure wave and then return the voltage to the emitter before leaving the emitter. The outer portion of the emitter assembly 500 as seen in FIG. 5A or the central core as seen in FIG. 5B is a first spark gap 508A where current from the emitter electrode 502A "jumps" to the hypotube electrode 502B.

[0068] In some, but not all, examples, a reflective surface or coating may be applied to surfaces within the spark gap 508 to reflect pressure waves radiated radially outward toward the interventional balloon 110 (FIG. 1). The reflective surface or coating may be an acoustically opaque, non-conductive (e.g., insulating) material such as, for example, ceramic, porcelain, diamond, polyimide, polyetheretherketone (PEEK), other similar materials, or other suitable combinations thereof.

[0069] The penultimate core, just below both the laser cut hypotube 502B and the emitter electrode 502A in FIG. 5A, can be seen wrapped around the central core in FIG. 5B, and is a coupler or insulator 504 that creates a space between the inner lumen and the emitter electrode 502A.

[0070] FIG. 6A illustrates a third example of an electron emitter assembly 600 for the catheter 104 of FIG. 1 , FIG. 6B illustrates a cross-sectional view of the emitter assembly 600, and FIG. 6C illustrates a cross-sectional view of the emitter assembly 600 with the potting material 412 removed to reveal the components embedded therein. In particular, the emitter assembly 600 includes two laser-cut “emitter” electrodes 602A, 602C positioned opposite a hypotube electrode 602B. As shown in FIG. 6C , in some, but not all, examples, the emitter electrodes 602A, 602C are configured to breach the outer surface of the inner elongate structure 506, for example, to help secure the emitter electrodes 602A, 602B in place. In such examples, the emitter electrodes 602A, 602B extend radially inward through the entire wall of the inner elongate structure 506 and partially into the guidewire lumen 322. The emitter electrodes 602A, 602B may additionally be potted in place, for example, embedded within the potting material 412.

[0071] The third example of an emitter assembly 600 shown in Figures 6A, 6B, and 6C is similar to the second example of an emitter assembly 500 shown in Figures 5A and 5B, except for the differences noted herein. For example, in both examples, a polyimide inner elongated structure 506 extends distally through the core of the emitter assembly, as seen on the outside of the assembly 600 in Figure 6A or in the radially innermost circle in Figures 6B and 6C.

[0072] Part of the outermost concentric ring above the central longitudinal axis 116 is a laser-cut hypotube electrode 602B that passes energy to the opposing emitter electrodes 602A, 602C. As mentioned above, below the central longitudinal axis 116 in FIG. 6C are two emitter electrodes 602A, 602C that extend radially inward through both the exterior and interior surfaces of the elongated structure 506. As specifically shown in FIG. 6C, multiple flat wires 406 are distributed circumferentially about the longitudinal axis 116 away from the emitter electrodes 602A, 602C to carry energy for generating high-energy pressure waves and return proximally to ground. In FIG. 6B, these flat wires 406 are represented as dashed lines embedded within the potting material 412; in FIG. 6C, they are represented as solid components because the potting material 412 has been removed to facilitate visualization of the flat wires 406 in this space.

[0073] 6A and 6B, the spark gap 608A, e.g., the portion where current “jumps” from the emitter electrode 602A to the hypotube electrode 602B, is shown as being substantially filled with potting material 412. In other examples, a section of the potting material 412 within the spark gap 608A may be milled out or otherwise removed. The potting material 412, shown in FIG. 6A just below both the laser-cut hypotube 602B and emitter 602A and wrapped around the inner elongate structure 506, may comprise any suitable adhesive or potting material, such as a UV adhesive, an epoxy resin, or a reflow polymer.

[0074] In some examples, pressure reflectors may be added within and / or around the spark gap 608A, the reflectors configured to redirect radially inward pressure waves to travel radially outward toward the intervention balloon 110 (FIGS. 1 and 3).

[0075] 7A-9 show three example electrode design configurations for laser-cut hypotubes 410 (FIG. 4B) that define two or more conductive electrodes for electron emitter assembly 400 (FIG. 4). These hypotube designs may be cut (e.g., laser cut) from a common 2D surface. In some examples, electrode designs may be cut from a planar 2D surface, which may then be formed into a cylindrical hypotube. In other examples, electrode designs may be cut directly from a cylindrical hypotube.

[0076] Examples of materials that can be used to cut conductive electrodes from a common planar or cylindrical hypotube include 304SST, titanium, cobalt chrome, 316SST, or nickel-titanium alloys (e.g., Nitinol), although other options are suitable as long as they have low degradation, low resistivity, ductility, and are machinable through the use of a laser. Furthermore, a flat sheet of material is not strictly required, as electrodes may be cut directly from the stent. In some instances, all of the emitters 114 in the emitter array 112 (FIG. 1) may be cut from a single, continuous hypotube. This has the advantage of facilitating the manufacturing process by eliminating the need to weld each individual emitter 114 to a wire.

[0077] FIG. 7A is a 2D representation of a first example design for a laser-cut hypotube 700 of electron emitter assembly 400 (FIG. 4), and FIG. 7B is a 3D representation of the first example hypotube 400 of FIG. 7A. For example, FIG. 7B shows how the hypotube 400 of FIG. 7A may appear when rolled into its final tubular form. As one non-limiting illustrative example, in the tubular form shown in FIG. 7B, the cylindrical hypotube 700 may define an inner diameter of about 0.025 to about 0.035 (e.g., about 0.03 inches) and an outer diameter of about 0.03 to about 0.04 inches (e.g., about 0.035 inches).

[0078] The hypotube design 700 shown in FIGS. 7A and 7B largely corresponds to the hypotube design 410 shown in FIG. 4. For example, the hypotube 700 defines a first electrode pair 402A / 402B having a spark gap 404A therebetween and a second electrode pair 402B / 402C having a spark gap 404B therebetween. FIGS. 7A and 7B illustrate a generally non-orthogonal hypotube design, in which the electrodes 402 have irregular shapes such that the spark gaps 404A, 404B are not oriented parallel to the central longitudinal axis 116. In particular, as shown in FIG. 7A, the electrodes 402A and 402C are generally shaped as rounded triangles (e.g., three-sided shapes with rounded corners), and the electrode 402B is generally shaped as a parallelogram. However, other configurations are also contemplated, such as all three electrodes 402A-402C being shaped as parallelograms.

[0079] The relative angle between the spark gaps 404A, 404B and the central longitudinal axis 116 may be varied across different emitters 114 (FIG. 1) to change the direction of propagation of the emitted pressure waves. In such an example, the clinician may independently activate different emitters to control this aspect of the IVL procedure.

[0080] 8A is a 2D representation of a second example design 800 for the laser-cut hypotube of electron emitter assembly 400 (FIG. 4). Compared to hypotube 410 shown in FIGS. 7A and 7B, hypotube design 800 comprises a more orthogonal design in which spark gaps 804A, 804B are oriented parallel to central longitudinal axis 116. For example, electrodes 802A-802C are more regular in shape, such as substantially rectangular, such that spark gaps 804A, 804B are substantially parallel to longitudinal axis 116.

[0081] For convenience, some non-limiting examples of various dimensions of hypotube 800 are shown in Figure 8. For example, hypotube 800 (shown in a flat configuration in Figure 8) may define a rectangle having a circumferential length 810A of approximately 0.1 inches. Rectangular width 810B (e.g., the longitudinal length of hypotube 800 along longitudinal axis 116) can range from approximately 0.080 inches to approximately 0.090 inches.

[0082] Each of the electrodes 802A, 802B, 802C may include a radiating edge 414 (FIG. 4) having a length 810C of about 0.040 inches to about 0.055 inches, for example, defining a spark gap 804A, 804B therebetween. The resulting spark gap may then define a gap width of about 0.0025 inches to about 0.0040 inches. The hypotube 800A may further include a plurality of support structures 806 configured to at least temporarily hold the primary structure (e.g., the electrode 802) in place during fabrication of the emitter assembly 114. These support structures 806 may then be removed, for example, after the electrode 802 is suspended in place via the potting material 412 (FIG. 4). The support structures 806 may define a width 810E of about 0.0020 inches.

[0083] FIG. 8B is a 2D representation of a hypotube array design 812 including multiple instances 800A-800D of the second hypotube design 800 of FIG. 8A. As referenced above, in some examples, two or more emitter units 114 (FIG. 1) of the emitter array 112 may be cut from a single continuous hypotube, or alternatively, cut from a common plane and then formed into a cylindrical hypotube. This technique facilitates the manufacturing process because it eliminates the need to weld the individual emitters 114 to wires. That is, instead of conductively coupling wires 406 (FIG. 4), the individual hypotubes 800A-800D may be conductively coupled via conductive coupling supports 814 cut from the same substrate as the emitters. The example design 812 shown in FIG. 8B also includes multiple detachable supports 816. The removable supports 816 may be initially cut into the common substrate of the hypotubes 800A-800D and the coupling supports 814 to help hold these components in place during manufacturing, and then removed after the hypotube array 812 has been assembled into a functioning emitter unit.

[0084] 9 is a 2D representation of a third example design 900 for the laser cut hypotube 410 of the electron emitter assembly 400 (FIG. 4). Similar to hypotube design 800 (FIG. 8), hypotube design 900 (in the planar configuration shown in FIG. 9) may define a rectangle having a circumferential length 910A of approximately 0.1 inches. The rectangular width 910B (e.g., the longitudinal length of the hypotube 900 along the longitudinal axis 116) can range from approximately 0.080 inches to approximately 0.090 inches.

[0085] In comparison to hypotube designs 700 (FIGS. 7A and 7B) and 800 (FIGS. 8A and 8B), both of which define generally linear spark gap configurations, electrodes 902A-902D of hypotube design 900 are shaped and oriented to define substantially rounded or annular spark gaps 904A-904D. For example, hypotube design 900 may include two substantially ring-shaped electrodes 902A, 902C, each defining an outer radius of approximately 0.0210 inches and an inner radius of approximately 0.013 inches. Centered on ring-shaped electrodes 902A, 902C are disk-shaped electrodes 902B, 902D, respectively. Disk-shaped electrodes 902B, 902D may define an outer radius of approximately 0.0090 inches. Thus, electrode pairs 902A / 902B and 902C / 902D may define respective ring- or semi-ring-shaped spark gaps 904 therebetween having a gap width of approximately 0.0040 inches. Similar to hypotube 800 (FIG. 8), hypotube 900 may first include one or more vertical support structures 906 that may be removed once electrodes 902 are bonded in place. Support structures 906 may define a width 910C of, for example, approximately 0.0030 inches.

[0086] Figure 10 is a flowchart 1000 illustrating an example technique for forming an electron emitter assembly for an IVL catheter, such as the emitter assembly 400 shown in Figure 4A. The technique of Figure 10 includes cutting a hypotube according to an electrode design, such as one of designs 700-900 in Figures 7A-9, respectively, to define one or more pairs of conductive electrodes aligned to define respective spark gaps therebetween (1002). The technique further includes inserting an elongate structure, such as inner elongate structure 318 in Figure 4A, into the lumen of the cut hypotube (1004).

[0087] In some, but not all, examples, as shown in FIG. 4B, additional layers may be inserted between the hypotube 410 and the inner elongate structure 318 to help provide structural support, improve thermal conductivity, or enhance energy efficiency. For example, a pressure reflector, a thermoplastic elastomer 416, a wire coil 418, or a polyimide layer 420 may be inserted (1006) if not already present. The technique of FIG. 10 further includes flowing a potting material 412 around the assembled components and solidifying or allowing the potting material layer 412 to solidify (1108) to hold the assembled components in place relative to one another.

[0088] In some, but not all, examples, the technique of FIG. 10 includes removing 1010 a portion of the potting material 412 from between the conductive electrodes of the hypotube to reconstruct the spark gap(s). For example, step 1010 may include milling out the potting material between the electrodes or removing the potting material via laser ablation, variable speed rotary tool removal, or other mechanical removal. In other examples, prior to pouring 1008 the potting layer, the technique of FIG. 10 may further include filling the spark gap(s) with an easily removable material that shields the potting material, and then removing the material. In other examples, the hypotube may be overmolded onto an existing potting layer to initially avoid filling the spark gap(s).

[0089] 10 further includes removing obsolete structural components from the hypotube 410. For example, as shown in FIG. 8A, the temporary support structure 806 may be removed from between the electrodes 802 once the electrodes 802 are secured in place.

[0090] 11A and 11B show an example flex circuit 1100 for the electron emitter assembly 400 (FIG. 4) of the IVL catheter 104 (FIG. 1). For example, conductive electrodes (e.g., copper foil strips) 1102A-1102C may be printed on a flexible, planar substrate 1106 to define respective spark gaps 1104 therebetween. The flexible substrate 1106 may then be rolled into the cylindrical shape shown in FIG. 11B and then wired to the rest of the emitter assembly 400 (FIG. 4). Such a technique may significantly reduce the manufacturing time of an IVL catheter 104 including such a circuit 1100.

[0091] For convenience, Figure 11 includes some non-limiting example dimensions of the flex circuit 1100. For example, the flex circuit 1100 may include a circumferential length 1110A of approximately 0.082 inches and an axial length 1110B (e.g., parallel to the longitudinal axis 116) of approximately 0.080 inches. The planar substrate may further define a main rectangular parallelepiped 1108 and two axial protrusions 1112A, 1112B. The main rectangular parallelepiped 1108 may have dimensions of a circumferential length 1110A of approximately 0.082 inches multiplied by an axial length 1110C of approximately 0.060 inches. The axial protrusion 1112 may similarly be substantially rectangular, defining a surface of a circumferential width 1110D of approximately 0.012 inches multiplied by an axial length 1110E of approximately 0.020 inches. The axial protrusions 1112A, 1112B may be circumferentially separated by a gap 1110F of approximately 0.046 inches.

[0092] 12A and 12B show two example wiring configurations 1200A, 1200B, respectively, for an emitter array 112 (FIG. 1) of an IVL device 108 that includes two flex circuits 1100A, 1100B (e.g., the flex circuit 1100 of FIGS. 11A and 11B). In particular, FIG. 12A shows example wiring configuration 1200A in which flex circuits 1102A, 1102B are wired in parallel. The top conductive wire 1202 (solid line) connects to a voltage input, and the bottom conductive wire 1204 (dashed line) connects to a ground voltage.

[0093] 12B shows another example wiring configuration 1200B in which the flex circuits 1102A, 1102B are wired to be independently operable. For example, a top conductive wire 1206 provides a connection between a voltage input and the flex circuit 1102B, and a middle conductive wire 1208 (solid line) provides a connection between a voltage input and the flex circuit 1102A. A bottom conductive wire 1210 provides a common connection to ground for both flex circuits 1102.

[0094] 13A and 13B show two example wiring configurations 1300A, 1300B, respectively, for conductively wiring the electron emitter array 400 (FIG. 4). In example 1300A shown in FIG. 13A, an elongated body includes an inner elongated structure 1302 (e.g., the polyimide inner layer 420 of FIG. 4) and an outer elongated structure 1304 having two nested layers, an inner layer 1306 and an outer layer 1308. A plurality of conductive wires 406, such as “flat” or “rectangular” wires, are wound axially and spirally along the outer surface of the inner layer 1306 of the outer elongated structure 1304. The outer layer 1308 of the outer elongated structure 1304, such as heat shrink tubing, thermoplastic tubing, or potting material 412 (FIG. 4), may be reflowed over the conductive wires 406 such that the conductive wires 406 are embedded in the outer layer 1308 of the outer elongated structure 1304.

[0095] In some examples, the outer layer 1308 of the outer elongate structure 1304 may be adjusted below the interventional balloon 110 ( FIG. 1 ), terminating a predetermined distance 1310 proximally from the distal end 1312 of the inner layer 1306 so that a distal portion of the conductive wire 406 is exposed. The conductive wire 406 may comprise a flat wire, a round wire, or a combination thereof. For example, in some examples, the conductive wire 406 may comprise a round wire with a “flattened” portion near the emitter 114.

[0096] In the wire configuration 1300A, the adhesive outer layer 1308 is "tacked" to the inner layer 1306 to reinforce the structure of the interventional balloon 110 (FIG. 1). This helps prevent the balloon 110 from "bellowing" during insertion or removal of the IVL device 108. The wire may also act as a reinforcement member for the outer elongate structure 1304.

[0097] In comparison, Figure 13B shows a different configuration 1300B in which the conductive wire 406 is spirally wound directly around the inner elongate structure 1302. In some instances, the use of flattened wire (e.g., a round wire with a flattened portion near the emitter) helps reduce the overall radial profile of the IVL device 108. In this configuration 1300B, the conductive wire 406 can also function as a stiffening member for the inner elongate structure 1302 (e.g., the coil layer 418 in Figure 4B).

[0098] 14A-14D are conceptual cross-sectional views illustrating four example wiring configurations 1400A-1400D, respectively, for the electron emitter array 112 of the catheter 104 of FIG. 1. In each of these four examples, the conductive wire 406 extends distally along the outer surface of the inner elongate structure 318 but is not rigidly coupled to the inner elongate structure 318.

[0099] 14A, the conductive wire(s) 406 extend generally linearly along the proximal direction, e.g., along the central longitudinal axis 116. In this configuration, the emitters 1406 may be wired in series, or in other examples, in a combination of parallel and series wiring.

[0100] In comparison, in the second example wiring configuration 1400B of FIG. 14B , the conductive wire(s) 406 are helically wound around the inner elongate structure 318 in a “single-wrap” configuration. In the single-wrap wiring configuration 1400B, two or more wires 406A, 406B are helically wound around each other with respective longitudinal spaces between adjacent coil turns. In these “coiled” configurations shown in FIGS. 14B, 14C, and 14D, the wire coils serve to provide structural support for the inner elongate structure 318, for example, by forming the coil layer 418 of FIG. 4B . In such an example, the emitter array may be wired according to an “n+1” configuration, where the number of conductive wires 406 is one greater than the number of emitters 1406, such that each emitter may have its own voltage supply wire but all share a common ground wire.

[0101] In a third example wiring configuration 1400C of Figure 14C, the conductive wire(s) 406 are helically wound around the inner elongate structure 318 in a "double wrap" configuration. In the double wrap wiring configuration 1400C, the wires 406 are helically wound around each other in wire pairs with respective longitudinal spaces between adjacent pairs of coil turns. The wire jacket portion 1408 may be removed (e.g., eliminated) if desired to conductively couple the wire 406 to the electrode hypotube 410 (Figure 4).

[0102] In a fourth example wiring configuration 1400D of FIG. 14D , the conductive wire 406 is helically wound around the inner elongate structure 318 in a "quadruple-wrap" configuration. In the quadruple-wrap wiring configuration 1400D, the wire 406 is helically wound around each other as four wire groups with longitudinal spaces between adjacent groups of four coil turns. The wire jacket portion 1408 may be removed (e.g., eliminated) if desired to conductively couple the wire 406 to the electrode hypotube 410 ( FIG. 4 ). In other examples, the wire may be wound in groups greater than four.

[0103] FIG. 15A is a conceptual diagram illustrating an example wiring configuration 1500A for an electron emitter array 1502A having four emitter units 1504A-1504D, and FIG. 15B is a conceptual diagram illustrating an example wiring configuration 1500B for an electron emitter array 1502B having five emitters 1504A-1504E. While only four emitters and five emitter assemblies 1502 are shown, it will be understood that any suitable and practical number of emitter units 1504 may be implemented within the IVL device 108. As referenced above, wiring configurations 1500A and 1500B are examples of an “n+1” configuration in which the number of conductive wires is one greater than the number of emitters 1504, such that each emitter 1504 has its own voltage supply wire, but all emitters 1504 share a common ground wire 1506. In such a configuration, each emitter 1504 is independently operable, providing the clinician with increased control over IVL treatment.

[0104] FIG. 16A is a conceptual diagram illustrating a first example wiring configuration 1600A for an electron emitter array 1602 having four emitter units 1604A-1604D. FIG. 16A illustrates a configuration in which the emitter units 1604 and emitter assemblies 1604 are wired in an “n+1” configuration, as in FIGS. 15A and 15B, and in which the emitter assemblies 1604 are wired in parallel. Some example advantages of the parallel wiring configuration 1600A include the ability to transmit higher currents across the emitter units 1604. The parallel wiring configuration 1600A also allows each individual emitter unit 1604 to be activated (or “fired”) independently of the other emitter units. Furthermore, the parallel wiring configuration 1600A can reduce the overall resistance of the IVL system 100 (FIG. 1). For example, individually powering a single emitter unit 1604 may generate a higher current across the spark gap 404 (FIG. 4), thereby reducing the number of resistors required in the corresponding electrical circuit.

[0105] Configuration 1600A may also allow for a reduction in the overall voltage through the system, translating, for example, into reduced energy consumption. The ability to individually power each emitter 1604 and select the order of firing of each emitter unit 1604 allows for better overall control of the IVL device 108, including how and where the applied energy is directed, as further detailed below.

[0106] FIG. 16B is a conceptual diagram illustrating a second example wiring configuration 1600B for the electron emitter array 1602 of FIG. 16A. In wiring configuration 1600B, a combination of both parallel and series wiring techniques may be implemented, enabling the benefits of both configurations. For example, emitters 1604A and 1604B are connected in series, while other emitters 1604 are connected in parallel. In particular, wiring configuration 1600B allows a clinician to simultaneously activate (1) emitters 1604A-1604D (e.g., using wires 1606A and 1606C), (2) emitters 1604C and 1604D (e.g., using wires 1606B and 1606C), or (3) emitters 1604A and 1604B (e.g., using wires 1606A and 1606B). However, FIG. 16B is not intended to be limiting, and any suitable wiring combination of emitters 1604 is contemplated and encompassed herein.

[0107] 17A is a conceptual diagram illustrating an IVL device 1700 having an array of optically-based pressure wave emitters 1702A-1702C (e.g., emitter array 112 of FIG. 1), and FIG. 17B is a cross-sectional view thereof. As used herein, optically-based emitter 1702 can include the distal end or distal portion of each optical fiber or tube 1704A-1704C, which may be included in IVL device 108 of FIG. 1 in addition to or as an alternative to one or more electronic emitter units described above.

[0108] According to some non-limiting examples, the optical fiber 1704 may deliver, for example, approximately 20-100 millijoules of energy within approximately 1 millisecond into the inflation fluid 408, such as water, a saline / contrast fluid mixture, other fluids, or combinations thereof, within the interventional balloon 110 to generate and propagate a high-energy pressure wave. However, these figures are merely exemplary, and the amount of energy and / or duration may be adjusted depending on the particular clinical application. In some examples, the emitted optical pulse width (e.g., emitted light duration) may be 5 nanoseconds or longer.

[0109] Given various clinical needs, the IVL device 1700 may include any suitable number of optical fibers 1704. In some examples, the IVL device 1700 is configured to transmit a laser signal having a wavelength of about 1064 nanometers (nm) to about 1460 nm, although shorter wavelengths may be effective as well. Example diameters for the optical fibers 1704 can range from about 50 microns or less to about 200 microns or more, depending on the particular clinical application.

[0110] As shown in FIG. 17A , in some examples, the distal emitter portion 1702A of the optical fiber 1704A may be oriented at a predetermined angle “θ” relative to the central longitudinal axis 116. For example, to protect the inner elongated structure 318, the distal emitter portion 1702A may be oriented at an angle θ greater than approximately 114 degrees, such as greater than 90 degrees, such as greater than approximately 24 degrees from the normal tangent. With respect to the optical fiber 1704A, only the most distal surface or end of the emitter portion 1702A is angled away from the inner elongated structure 318. In other examples, such as the example of optical fiber 1704B, the entire distal portion 1702B may be angled to bend or away from the inner elongated structure 318. In such examples, the optical fiber distal portion 1702B may be deflected by an angle “φ” between approximately 0 degrees and approximately 24 degrees.

[0111] The optical emitters 1702 of the optical fibers 1704 may be positioned circumferentially around the inner elongate structure 318 (e.g., as shown in FIG. 17B ), or in other examples, longitudinally along the inner elongate structure 318, or in yet other examples, any combination thereof, to emit and deliver high-energy pressure waves. For example, the optical fibers 1704 may be adjacent to the inner elongate structure 318 for circumferential lesion treatment (e.g., 1704A) or radially off-center for non-circumferential lesion treatment (e.g., 1704B). Some example benefits of using multiple optical fibers 1704 include reducing the overall cross-sectional profile of the IVL device 1700 by positioning the optical fibers 1704 around the proximal portion of the catheter elongate body 106 ( FIG. 1 ). Additionally, a greater number of optical fibers 1704 allows for more controlled pressure waves. In addition to directing energy based on where the optical fibers 1704 are placed around the IVL catheter 104, the size of the cavitation bubbles may be controlled based on the selected diameter (e.g., cross-sectional area) of the optical fibers 1704. These optical fibers 1704 may be activated individually or simultaneously based on the treatment needs, allowing, for example, a single IVL device 108 that can treat both circumferential and nodular calcified lesions.

[0112] 18 is a cross-sectional view of an example IVL device 1800 (e.g., IVL device 108 of FIG. 1) with an interventional balloon 1810 (e.g., balloon 110 of FIG. 1) having a multi-layer construction for increased durability. As shown, balloon 1810 may have an outer layer 1802 and an inner layer 1804 for reinforcing layer purposes. Either or both of reinforcing layers 1802, 1804 may comprise a separate extrusion overlying balloon 1810, with another layer overlying this pressure-retaining layer.

[0113] The example shown in Figure 18 represents only one of many solutions to the potential risk of balloon rupture. For example, balloon 1810 may be formed from a single multi-layer extrusion, with a thin, more flexible layer 1802 on the outside of the balloon being softer and less susceptible to tearing than an inner, high-pressure, non-compliant (or "less flexible") retention layer 1804. For example, one example construction could include a high-pressure inner retention layer 1804, such as Nylon 12 or Pebax 72D, making up, for example, between 70% and 100% of the balloon wall thickness. The outer layer 1802 is made of a more flexible material, such as urethane, Pebax, or any other suitable material having a medium-to-low durometer measurement, e.g., about 63D or less.

[0114] Another solution is to form the balloon from two separate extrusions 1802, 1804, e.g., a separate extrusion 1802 on the outside of the balloon disposed on the exterior surface of an inner non-compliant or semi-compliant balloon 1804. Another solution is to form the balloon 1810 from a thin polymer inner layer 1804 covered by a reinforcing layer 1806, such as a polymer fiber such as aramid or UHMWPE, with a top coating 1802 for encapsulating the fiber. The outer layer 1802 may, by way of non-limiting example, comprise multiple reinforcing layers, e.g., a set of 16 braided fibers and 4 to 8 (inclusive) longitudinal fibers. Other variations in braid patterns are also possible, such as those containing 32 fibers or 48 fibers. Furthermore, the reinforcing fibers may be arranged in an orthogonal weave pattern, such as a mesh sheet cut into individual pieces, as opposed to (or in addition to) being braided directly onto the balloon 1810.

[0115] Although not shown in FIG. 18 , another solution to potential balloon rupture is to coat the balloon with an abrasion-resistant coating, such as the outer coating 326 of FIG. 3 . This solution may be achieved by applying the coating to the balloon 1800 through dipping, spraying, or roll-casting. According to some examples, this coating may be or include a polymer, such as urethane, parylene, silicone, or thermoplastic polyurethane (TPU). These coatings may enable the balloon 1810 to sustain high pressures while protecting the balloon structure from damage due to contact with calcified lesions within the target vessel. Although not shown, another technique involves implementing a flexible balloon body to accommodate plaque and puncture resistance. In an example of this solution, non-compliant cones on either end of the balloon would be implemented to prevent pressure waves from propagating proximally to or distally from the balloon 110.

[0116] 19 and 20 show two example IVL devices 1900, 2000, respectively, having an interventional balloon 110 with a protective structure 1902, 2002 or "protective cage." Specifically, FIG. 19 is a side view of a first example IVL device 1900 having a first such protective structure 1902, and FIG. 20 is a side view of a second example IVL device 2000 having a second such protective structure 2002.

[0117] These protective structures 1902, 2002 are configured to provide similar rupture protection to the more continuous balloon outer layer or coating 1802 described above with respect to Figure 18. According to any of these examples, the balloon 110 can have a cage-like structure thereon that can reduce direct physical contact (e.g., friction) between the outer surface of the balloon and calcified plaque lesions attached to the vessel wall.

[0118] The cage-like structure 1902, 2002 may be or include a metal or polymer, such as SST or Nitinol. In a balloon with multiple nested layers (e.g., balloon 1800 of FIG. 18 ), the protective structure 1902, 2002 may be disposed between the outer and inner balloon layers 1802, 1804. In some examples, the cage-like structure 1902, 2002 comprises multiple longitudinal members, e.g., extending parallel to the central longitudinal axis 116. In such examples, the protective structure 1902, 2002 may be selected to comprise an odd number of longitudinal members, such as three or five longitudinal members, to facilitate rewrapping of each balloon prior to withdrawal of the IVL device 108 from the patient's vasculature. These longitudinal members or bars may be interconnected as a stent-like structure such that the structure has a predetermined size and shape that does not change (or changes relatively little) during inflation of the balloon 110.

[0119] According to some examples, the protective structures 1902, 2002 are rigidly coupled to the outer surface of the balloon 110. In such examples, the protective structures 1902, 2002 are rigidly coupled to the proximal and distal ends of the balloon 110, but are not coupled to the central longitudinal balloon portion.

[0120] The example of Figure 19 shows a less comprehensive protective structure 1902 compared to the example protective structure 2002 of Figure 20. For example, protective structure 1902 comprises, by way of non-limiting example, two (top and bottom) longitudinal elements 1904 and approximately thirteen circumferential elements 1906. In comparison, protective structure 2002 is shown to comprise a more continuous wire mesh configuration or a window screen configuration having tens or hundreds of interwoven longitudinal and circumferential elements.

[0121] 21 illustrates an example IVL device 2100 (e.g., IVL device 108 of FIG. 1) that includes a pair of scoring members 2102A, 2102B. The scoring members 2102 are configured to physically contact and abrade the interior surface of a calcified plaque lesion (e.g., through friction exerted over a substantially small surface area, corresponding to a substantially high stress / pressure at that point), helping to fracture and disintegrate the lesion.

[0122] In some examples, the scoring element 2102 may be coupled to a protective structure within or on the balloon 110 (e.g., protective cages 1902, 2002 in FIGS. 19 and 20, respectively). In some examples, the balloon 110 may include a single scoring element 2102. In other examples, multiple scoring elements 2102 may be rotationally, symmetrically, or asymmetrically distributed around the circumference of the balloon 110. During an IVL procedure, the balloon 110 may be rotated circumferentially to apply a particular scoring element or elements 2102 to the calcified lesion. In some examples, the scoring element 2102 may be formed from a metal such as SST or a nickel-titanium alloy (e.g., Nitinol), a metal wire, a printed metallic ink (which may contain a small amount of polymeric binder from processing), tungsten, or a polymer.

[0123] In some examples, such as the example shown in Figure 21, the scoring member 2102 may include a generally flat or planar outer surface. In other examples, the scoring member 2102 may include a toothed or serrated outer surface, for example, to increase dynamic friction when contacting a calcified plaque lesion.

[0124] 22 illustrates an example IVL device 2200 (e.g., IVL device 108 of FIG. 1) that includes a fragmentation element 2202 configured to aid in fragmenting calcified plaque lesions during an IVL procedure. As shown in FIG. 22, the fragmentation element 2202 includes an elongated conductive wire 2204 and a plurality of piezoelectric elements 2206 distributed longitudinally along the wire 2204.

[0125] The fragmentation element 2202 provides at least two advantages. First, when the conductive wire 2204 is aligned against a calcified plaque lesion, the narrow cross-sectional area of ​​the conductive wire 2204 substantially increases the pressure exerted on the lesion along the axis of the wire, allowing the clinician to control the specific location where the lesion begins to fragment. Second, when an alternating current (AC) is applied through the conductive wire 2204, the piezoelectric element 2206 is configured to rapidly expand and contract, thereby generating additional pressure waves that are focused directly against the outer surface of the lesion.

[0126] 24A , the disruption element 2200 includes a distal protection element, such as an embolic protection element, as described further below. For example, the distal protection element may be connected to a distal portion of the conductive wire 2204. Additionally or alternatively to the wire 2204, the disruption element 2200 may include a braided layer, such as a nitinol braid. The piezoelectric element 2206 may be securely coupled to the outer surface of the braid, which may be coupled to the outer surface of the balloon 110. This braid may perform a similar function as that described above with respect to the wire 2204.

[0127] FIG. 23 illustrates an example IVL device 2300 (e.g., IVL device 108 of FIG. 1) having a spring mechanism 2302. In some of the previous devices, the interventional balloon 110 can be difficult to insert into and remove from an introducer sheath (not shown) during an IVL procedure. This can be caused, for example, by excessively bulky proximal and / or distal balloon cones (e.g., compared to the distal balloon cone 1404 of FIG. 14A) or a lack of effective folding or wrapping of the balloon 110 during and / or after deflation. In some instances, this problem can be resolved by reducing the radial profile (e.g., cross-sectional area) of the balloon while in an uninflated or deflated state. This can also be achieved by longitudinally stretching the balloon 110 while the proximal and distal ends of the balloon are coupled to the inner elongate structure 318.

[0128] Another technique for reducing the profile of the balloon 110, shown in FIG. 23, is to incorporate a spring 2302 within the inner elongate structure 318. The spring 2302 must be longitudinally compressed when coupled to the inner elongate structure 318 (e.g., at the proximal and distal ends 2304A, 2304B). The balloon 110 may then be bonded to the inner elongate structure 318 such that the inner elongate structure 318 and balloon 110 similarly elongate along the longitudinal direction 116 and compress radially inward once the spring 2302 is allowed to expand back to its rest length. The balloon 110 may also be longitudinally stretched around the tube 318 (as described above) during the bonding process to further facilitate this technique. During inflation, the balloon 110 still expands to its preformed shape while the inner elongate structure 318 compresses slightly longitudinally. That is, the proximal and distal points where balloon 110 is joined to inner elongate structure 318 may compress slightly toward each other as balloon 110 expands radially outward.

[0129] Another technique for reducing the cross-sectional profile of the balloon 110 is to improve rewrapping of the balloon after deflation during the procedure. This can be achieved in a number of ways, such as by incorporating or embedding multiple longitudinal wires into the balloon body. These longitudinal wires may help define pleats or predetermined fold positions for the balloon 110, rather than allowing the balloon material to "bundle" randomly. While any number of longitudinal wires may be incorporated, an odd number of longitudinal wires helps prevent the balloon from collapsing into a plane of symmetry, such as a "paddle" or "pancake" configuration. Additionally, the longitudinal members may be radiopaque so that they can be used to visualize the inflated balloon 110 and its adherence against the vessel wall during the IVL procedure. Such a configuration can potentially reduce the overall time of the IVL procedure by eliminating the need for a separate fluid contrast agent. In some examples, these longitudinal wires may be composed of metal wires (e.g., flat, round, or irregularly shaped such as pentagonal), printed inks (e.g., metal or polymer inks), or polymer structures.

[0130] FIG. 24 illustrates an example IVL device 2400 (e.g., the IVL device 108 of FIG. 1 ) that includes a distal protection device 2402. According to some examples, the distal protection device 2402 may be positioned at the distal end of the IVL device 2400. In some examples (but not all examples), the distal protection device 2402 includes an elongate element 2404 (e.g., a guidewire) extending through, for example, the guidewire lumen 322 of the inner elongate structure 318, and a distal expandable member 2406. In such examples, the expandable member 2406 extends distally outward from the distal port 324 and is configured to expand radially outward to the expanded configuration shown in FIG. 24 . The inner lumen 322 of the inner elongate structure 318, which surrounds the expanded distal protection device 2402, may be capable of accommodating a 0.010 inch to 0.035 inch guidewire. Thus, the size of the guidewire lumen can range from 0.011 inches to 0.038 inches, allowing free movement of the guidewire.

[0131] The distal protection device 2402 is configured to capture calcified particles generated during the IVL procedure. The expandable member 2406 may comprise a basket frame design, as shown in FIG. 24A , although other suitable designs are contemplated. In such examples, the basket frame 2406 may be or include a nitinol cut tube (similar to a stent) or a nitinol wire frame. The material comprising the basket 2406 may be a thin polymer or fiber mesh with cut holes. According to some examples, the basket frame 2406 may be positioned outside the balloon catheter 104, with the distal protection member shaft 2404 designed to be compatible with the balloon inflation (where the balloon 110 is pressed against the shaft 2404 of the filter device 2402).

[0132] The distal protection device 2402 may also be rapidly exchanged on the balloon catheter 104. The rapid exchange port may be proximal to the balloon 110 or distal to the balloon 110. The distal protection device 2402 may enter or exit the balloon catheter at a hub 306 (FIG. 3) proximal to the balloon 110 or distal to the balloon 110. This distal protection device 2402 may be modular (e.g., detachable) in nature such that it is only present in the IVL device 2400 when needed for the procedure.

[0133] FIG. 25 illustrates an example of the IVL system 100 of FIG. 1 with a closed-loop energy delivery feedback mechanism. With current IVL systems, the amount of energy delivered is fixed and not tailored to clinical need. The present disclosure enables automatic delivery of energy based on a presented clinical scenario to improve treatment effectiveness and efficiency, for example, via sensors 2502 measuring fluid pressure, fluid volume / velocity, and / or temperature. Any combination or use of monitoring provided by the controls as disclosed herein may provide input to determine the maximum pressure wave intensity and / or heat level generated by the emitter.

[0134] According to some examples, the system 100 may include one or more sensors 2502, for example, integrated into the energy generator 102, the catheter 104, or both. Based on data received from the sensors 2502, the system 100 (e.g., processing circuitry of the generator 102 or a separate computing device associated with the system 100) is configured to dynamically (e.g., in real time) adjust the energy level output by the generator 102.

[0135] For example, the sensor(s) 2502 may comprise, by way of non-limiting example, an inflation fluid flow rate monitor, an inflation fluid pressure monitor, a vessel wall monitor, a vessel diameter monitor, a balloon diameter monitor, a plaque disruption monitor, or any other type of sensor configured to provide insight into the current progress of the IVL procedure. In some examples, the sensor 2502 is configured to detect the resonant frequency (e.g., natural frequency or harmonic frequency) of calcium in the lesion.

[0136] Based on real-time monitoring of sensor data from the sensor(s) 2502, the system 100 may be configured to dynamically adjust one or more of the current level, voltage level, electrical pulse duration or frequency, light intensity, light pulse duration, light pulse frequency, or any other suitable parameters that affect the amount or rate of energy delivered via the emitter array 112. As a specific example of plaque lesion resonant frequency, the system 100 may be configured to automatically adjust the emitter audio frequency to match the resonant frequency of the detected lesion to more effectively disrupt the lesion.

[0137] In some examples, in addition to or as an alternative to dynamically adjusting the energy level, the system 100 is configured to automatically terminate the applied voltage when certain conditions are met, including (but not limited to) threshold disruption of a calcified plaque lesion is achieved or a detected system parameter is outside a threshold level (e.g., suspected failure of the balloon 110 or other component).

[0138] As one illustrative example, the IVL system 100 may be configured to monitor the fluid pressure of the balloon 110. For example, the sensor 2502 may include a pressure transducer configured to interface with the inflation lumen 320. Accordingly, the system 100 may further include a three-way fluid connector (e.g., the catheter hub 306 of FIG. 3 ) configured to fluidly couple the inflation syringe (e.g., the inflation port 310), the inflation lumen 320, and a pressure line returning to the energy generator 102. The pressure transducer may be integrated into the energy generator 102 and fluidly connected along the pressure line. In such an example, the fluid line may also include a transducer protection, such as a valve or membrane, configured to prevent the inflation fluid 408, e.g., a saline / contrast fluid mixture, from entering the components of the energy generator 102.

[0139] As another illustrative example, IVL system 100 (e.g., processing circuitry of energy generator 102 or another computing device associated with system 100) may be configured to monitor the electrical impedance of one or more components of system 100. When a plasma is created in spark gap 404 between electrode pair 402 (FIG. 4), the local electrical impedance drops, thereby causing system 100 to terminate (upon detection) the applied voltage. Additionally or alternatively, system 100 (e.g., measurement unit 216 of FIG. 2) may be configured to monitor the level of current produced by generator 102 while it is being output, and automatically terminate the applied voltage in response to a supra-threshold change in the monitored current.

[0140] In other examples, rather than dynamically modifying the energy level (e.g., applied voltage level, etc.), system 100 may be configured to apply the energy level (e.g., voltage level) as an "all or none" (e.g., binary 0 or 1). For example, system 100 may transmit a predetermined level of energy through catheter 104 only while certain conditions are determined to be met, as indicated by data from sensor 2502. Additionally or alternatively, system 100 may be configured to adjust other parameters. For example, system 100 may be configured to dynamically adjust the longitudinal length and / or inflation diameter of balloon 110 as needed.

[0141] Figure 26 shows an example handle 2600 that may be coupled at the proximal section 302 (Figure 3) of the IVL catheter 104 of Figure 1. The catheter 104 may include the handle 2600 in addition to or instead of the catheter hub 306 (Figure 1). When both the hub 306 and the handle 2600 are present, the handle 2600 may be coupled to a portion of the elongate body 106 that extends proximally through the hub access port 308.

[0142] Existing IVL catheters require expensive generators to power the catheter. In the example shown in FIG. 26, a catheter handle 2600 includes an integrated power supply 2602. The power supply 2602 may include a battery, a capacitor, or any other suitable integrated power source configured to deliver a power level sufficient to operate the emitter array 112 (FIG. 1). That is, in some examples, the system 100 (FIG. 1) may include the handle 2600 in place of the energy generator 102. In other examples, the handle 2600 may be configured to provide supplemental or auxiliary power to the emitter array 112. In some examples, similar to a laptop or other mobile device, the catheter 104 may be removably coupled to the energy generator 102 and configured to function either while connected or disconnected.

[0143] Typical IVL systems and devices are configured to emit high-energy pressure waves that propagate across all spatial dimensions. This characteristic can be relatively effective against, for example, ring-shaped calcified plaque lesions that appear around the entire inner circumference of a vessel wall. However, other lesion morphologies may not be effectively treated, or alternatively, a significant amount of energy may be wasted due to inefficient energy application. Accordingly, numerous features and techniques are disclosed herein that enable the IVL device 108 (FIG. 1) to focus the emitted high-energy pressure waves in a specific spatial direction or a limited range of directions.

[0144] For example, FIG. 27 is a cross-sectional view of an IVL device 2700 (e.g., IVL device 108 of FIG. 1) having an example first waveguide 2702. In some examples, the waveguide 2702 includes a layer of material oriented along only a portion of the inner circumference of the balloon 110 and extending longitudinally (e.g., proximally and distally) through the balloon 110. The material is configured to substantially absorb and / or reflect pressure waves that contact the material, thereby reducing energy wasted by being directed in any direction. As described above, this acoustically opaque material can include, for example, ceramic, porcelain, diamond, polyimide, polyetheretherketone (PEEK), similar materials, or any suitable combination thereof.

[0145] 27, the waveguide 2702 is shown as having a half-moon shaped cross-sectional profile, although other configurations are contemplated. For example, the waveguide 2702 may define a substantially semicircular cross-sectional profile, or alternatively, may comprise a relatively thin layer coating on a portion of the inner surface of the balloon 110.

[0146] In some examples, the director 2702 includes a distinctive lumen "pocket" 2704 that can be inflated or deflated as needed, as in a typical balloon angioplasty procedure. In some examples, the fluid pocket 2704, separate from the inflation lumen 320 (FIG. 3), is configured to deliver gas to inflate the pocket 2704 without interfering with the inflation of the balloon 110 itself. During use of the IVL device 2700, pressure waves radiating from the spark gap 404A cannot penetrate the fluid pocket 2704 and are therefore absorbed and / or reflected in the opposite circumferential direction.

[0147] In addition to or alternatively to an absorptive and / or reflective material, the director 2702 of FIG. 27 may be or include at least one of the pair of electrodes 402 (FIG. 4) of the electron emitter unit 400. For example, the half-moon shaped director 2702 may comprise one or both of the electrodes 402 to directionally focus the emitted pressure waves to disrupt calcifications of the target. In examples in which the director 2702 comprises both a reflective material and one or both electrodes 402, the electrode(s) 402 may be positioned radially inward from the reflective material, which may be adhered to the inner surface of the balloon 110.

[0148] Additionally or alternatively to reflective materials, in some examples, the compositional material of balloon 110 may be strategically varied to provide directionally targeted wave radiation. For example, the material of balloon 110 may be configured to be thicker along some portions of its circumference than along other portions. In some examples, balloon 110 may incorporate a more transparent material along a first portion of its circumference and a more absorbent and / or more reflective material along a second portion of its circumference.

[0149] In some examples, a fluoroscopy wire (e.g., the conductive wire 2204 described above with respect to FIG. 22) or other visual indicator 2704 may be positioned opposite the director 2702. The visual indicator 2704 assists the clinician in aiming (e.g., rotating) the IVL device 2700 toward the target calcification prior to the onset of target disruption. Also, as described above with respect to FIG. 22, in some examples, the piezoelectric elements 2206 can be mounted or extended (e.g., asymmetrically distributed) off-center on or within the balloon 110 to increase energy on its sides. In such examples, tissue regions adjacent the piezoelectric elements 2206 receive a greater amount of energy, thereby enabling directionally targeted disruption of the lesion.

[0150] Figure 28A is a perspective view and Figure 28B is a cross-sectional view of a second example of a directed focusing IVL device 2800 (e.g., IVL device 108 of Figure 1). The IVL device 2800 comprises an array of emitter assemblies 2814, each of which comprises two or more individual emitter units 2816 circumferentially distributed around an inner elongated structure 318. Each of the individual emitter units 2816 can comprise an electrode pair, a piezoelectric element, or an optical emitter.

[0151] 28A and 28B, the emitter units 2816 may be configured to be mounted or expanded at an off-center position within the cross-sectional area of ​​the balloon 110, thereby increasing the energy delivered to each side of the balloon 110. In some examples, each of the individual emitter units 2816 is configured to be independently actuable. In other examples, all of the individual emitter units 2816 of different emitter assemblies 2814 aligned along a common longitudinal axis are commonly actuable. Additionally or alternatively, the individual emitter units 2816 can be configured to tilt or bend toward and away from the inner elongate structure 318 while attached to the stem 2818 to further control directional energy transmission.

[0152] 28A and 28B, the IVL device 2800 can also include one or more radiopaque visual indicators 2704 to aid in orientation of the device relative to the target treatment site. However, as shown in FIG. 28B, the visual indicators 2704 should be asymmetrically distributed around the circumference of the balloon 110 to prevent ambiguous balloon orientation determination.

[0153] FIG. 29A is a perspective view of a third example IVL device 2900 (e.g., IVL device 108 of FIG. 1 ), and FIG. 29B is a cross-sectional view thereof. IVL device 2900 is the example IVL device 2800 of FIG. 28 , except for the differences noted herein. In particular, the interventional balloon 110 of IVL device 2900 comprises two or more elongate sub-balloons 2902 circumferentially distributed around an inner elongate structure 318. Each sub-balloon 2902 is configured to carry a subset of emitter units 2816 oriented along a common longitudinal axis. Each emitter unit subset is configured to be operable independently of the other emitter unit subsets, and each sub-balloon 2902 is configured to serve to apply radiated pressure waves to a specific portion of the circumference of the inner surface of a target blood vessel.

[0154] In some examples, each sub-balloon 2902 is configured to be individually inflatable, e.g., according to a different inflation rate or amount than the other sub-balloons. In this manner, the IVL device may be positioned off-center toward a particular portion of the vessel wall (e.g., a calcified lesion). Such examples allow each subset of emitter units 2816 with a corresponding scoring member 2102 (FIG. 21), if present, to be positioned closer to the intended treatment site.

[0155] As described above, the emitters 2618 can be angled away from the inner elongate structure 318 so that they are closer to the inner diameter wall of the balloon 110 (e.g., instead of adjacent to the inner elongate structure 318). Thus, the energy delivered by these emitters 2816 can be more focused on the vessel wall to which they are closest positioned. This, in combination with a cutting wire (e.g., the conductive wire 2204 of the fragmentation element 2202 in FIG. 22), can create a high-pressure stress focal point to more efficiently and / or effectively fragment nodular calcified lesions.

[0156] 28A and 29B, the energy generator 102 (FIG. 1) may independently and selectively control emitters 2816 present around the circumference of the IVL device 2900. This means that energy delivery can be controlled by only firing the emitters 2816 closest to the calcified lesion, without tilting or even moving the emitters 2816 in any direction. Furthermore, if the proposed treatment requires circumferential energy delivery, all emitters 2816 may still be fired, allowing a more conventional style treatment to occur.

[0157] It should be noted that these emitters 2816 can all be located within the same balloon 110, as shown in Figures 28A and 28B, or within their own separate sub-balloons 2902, as shown in Figures 29A and 29B. Furthermore, it should be noted that while the relative arrangement shown in Figures 28B and 29B allows for only one arrangement of emitter units, these emitters 2816 can be placed around the catheter throughout the balloon 110, with the number of emitters possible being dictated only by the length of the balloon 110 being used. [Explanation of symbols]

[0158] 100-Intravascular Lithotripsy (IVL) System 102-Energy Generator 104-Catheter 106-Long catheter body 108-IVL device 110-Interventional Balloon 112-Pressure Wave Emitter Array 114A - First emitter 114B-Second Emitter 114C-Third Emitter 114D-4th Emitter 114E-5th Emitter 116-Central Longitudinal Axis 118-Detachable Cable 202-Power Input Connector 204-Catheter Connector 208-Internal power supply 210-High Voltage DC-DC Converter 212-High Voltage Capacitors and Transistor Switches 216-Voltage and Current Measuring Unit 218-Processor 218 222-Device Identification Unit 224-Power Module 226-User Interface (UI) Control Processing Unit 234-User Interface 302-Proximal catheter section 304-Distal catheter section 306-Catheter Hub 308-Access Port 310-Inflation port 312-Power Port 314-Strain Relief 316-Outer long structure 318-Inner long structure 320-inflation lumens 322-Guidewire lumen 324-Distal Port 326-Outer balloon coating 400-First Electrical Emitter Assembly 402A-1st electrode 402B-Second electrode 402C-3rd electrode 404A-1st spark gap 404B-Second spark gap 406A-1st wire 406B-Second Wire 408-Expansion Fluid 410-Hypotube 412-Potting material 414-electrode end 416-Elastomer layer 418-Coil 420-Polymer layer 500-Second Electrical Emitter Assembly 502A - First emitter electrode 502B-Hypotube Electrode 502C - Second emitter electrode 504-insulating layer 506-Polyimide inner long structure 508A, 508B - Spark gap 600-Third Electric Emitter Assembly 602A - First emitter electrode 602B-Hypotube Electrode 602C - Second emitter electrode 608-Spark Gap 700-1st Hypotube Design 800-2nd Hypotube Design 802A-1st electrode 802B-Second electrode 802C-3rd electrode 804A-1st Spark Gap 804B-Second Spark Gap 806-Support structures 810A-Circumference length 810B-Longitudinal length 810C-electrode end length 810D-Spark Gap Width 810E - Support structure width 812-Hypotube Array Design 814-Coupling support 816-Detachable support part 900-3rd Hypotube Design 902A-1st ring electrode 902B-First disc electrode 902C-Second ring electrode 902D-Second disc electrode 904-Spark Gap 906-Support structures 910A-Circumference length 910B-Longitudinal length 910C-Support structure width 1000-Assembly Technology 1002~1010-Assembly steps 1100-Flex Circuit 1102A-1st electrode 1102B-Second electrode 1102C-3rd electrode 1104-Spark Gap 1108-Flexible PCB 1110A-Circumference length 1110B-Flex circuit longitudinal length 1110C-Rectangle Longitudinal Length 1110D-protrusion circumference width 1110E-Protrusion longitudinal length 1110F-Protrusion gap circumference length 1112-protrusion 1200A-1st flex circuit wiring configuration 1200B-2nd flex circuit wiring configuration 1202-Upper Wire 1204-Bottom Wire 1206-Upper Wire 1208-Central Wire 1210-Bottom Wire 1300A-1st wiring form 1300B-Second wiring configuration 1302-Inner long structure 1304-External Long Structure 1306-Outer structure inner layer 1308-Outer structure outer layer 1310-Outer structure outer layer end point 1312-Outer structure inner layer end point 1400A~D-Wiring form 1402-wire loopback point 1404-Distal Balloon Cone 1406-Emitter 1408-Exposed Wire Conductor Point 1500A-1st wiring form 1500B-Second wiring configuration 1502A - Four Emitter Array 1502B - Five Emitter Array 1504-Electric Emitter 1506-Ground Wire 1600A-1st wiring form 1600B-Second wiring configuration 1602-Emitter Array 1604-Emitter 1606-Conductive Wire 1700-IVL device 1702-Optical Emitter 1704-Optical Fiber 1800-IVL device 1802-Balloon outer layer 1804-Balloon inner layer 1806-Balloon center layer 1810-Interventional Balloon 1900-Intervention Device 1902-1st protective structure 1904-Longitudinal member 1906-Circumferential member 2000-IVL device 2002-Second protection structure 2100-IVL device 2102-Scoring material 2200-IVL device 2202-Fracture Element 2204-Wire 2206-Piezoelectric element 2300-IVL device 2302-Spring 2304A-Spring proximal end 2304B-Spring Distal End 2400-IVL device 2402-Distal Protection Device 2404-Long Element 2406-Expandable basket member 2502-Sensor 2600-Catheter Handle 2602-Integrated power supply 2700-IVL device 2702-Wave director 2704-Fluid Pocket 2704-Visual Direction Indicator 2800-IVL device 2814-Emitter Assembly 2816-Emitter Unit 2900-IVL device 2902-Sub Balloon

Claims

1. laser cutting the hypotube to define at least a first emitter and a second emitter positioned to define a spark gap therebetween; inserting an elongate body through the laser cut hypotube; extending i) the first emitter, ii) the second emitter, or iii) both radially inward at least partially through an outer surface of the elongated body; and flowing a potting material around the laser cut hypotube.

2. the spark gap comprises a first spark gap; 10. The method of claim 1, wherein laser cutting the hypotube further comprises laser cutting the hypotube to define the third emitter positioned to define a second spark gap between the second emitter and a third emitter.

3. The method of claim 2 , wherein the first emitter, the second emitter, and the third emitter all define a portion of a common cylindrical surface of the hypotube.

4. 4. The method of claim 3, wherein laser cutting the hypotube comprises laser cutting the hypotube so that the first emitter and the third emitter both define a rounded triangular shape and the second emitter defines a parallelogram shape.

5. 4. The method of claim 3, wherein laser cutting the hypotube comprises laser cutting the hypotube such that the first emitter, the second emitter, and the third emitter all define a rounded rectangular shape.

6. 4. The method of claim 3, wherein laser cutting the hypotube comprises laser cutting the hypotube so that the first emitter and the third emitter both define an elliptical shape and the second emitter defines a semi-cylindrical shape.

7. 10. The method of claim 1, wherein the first emitter is ring-shaped and the second emitter is disk-shaped, the first emitter at least partially surrounding the second emitter.

8. the spark gap comprises a first spark gap; laser cutting the hypotube further comprises laser cutting the hypotube to define a third emitter and a fourth emitter positioned to define a second spark gap therebetween; The method of claim 7 , wherein the third emitter is ring-shaped and the fourth emitter is disk-shaped, and the third emitter at least partially surrounds the fourth emitter.

9. The method of claim 1 , wherein the hypotube defines a longitudinal length of about 0.080 inches to about 0.090 inches.

10. The method of claim 1 , wherein the hypotube defines a circumference of about 0.10 inches to about 0.12 inches.

11. The method of claim 1 , wherein the first emitter is rectangular shaped.

12. 2. The method of claim 1, wherein extending i) the first emitter, ii) the second emitter, or iii) both at least partially radially inward through an outer surface of the elongate body comprises extending the first emitter at least partially radially inward through an outer surface of the elongate body, the method further comprising extending the first emitter radially inward through the elongate body and at least partially radially inward into an inner lumen of the elongate body.

13. The method of claim 12 , further comprising extending the second emitter at least partially radially inward through the elongate body.

14. 14. The method of claim 13, further comprising extending the second emitter at least partially radially inward into the inner lumen of the elongate body.

15. The method of claim 1 , further comprising removing obsolete support structures from the hypotube.

16. The method of claim 15 , wherein the potting material is an adhesive.

17. 17. The method of claim 16, wherein removing obsolete support structures from the hypotube comprises scraping away the adhesive.

18. 18. The method of claim 17, wherein scraping away the adhesive comprises rebuilding the spark gap between the first emitter and the second emitter.

19. 17. The method of claim 16, wherein flowing the potting material around the laser cut hypotube comprises flooding an adhesive around the laser cut hypotube.

20. the elongate body having a proximal end and a distal end opposite the proximal end; The method of claim 1 , wherein the elongate body is configured to deliver a fluid to the distal end.

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