Burst mode operation of intravascular lithotripsy (IVL)

Abstract

This document discloses a system and method for applying voltage to electrodes in a shock waveguide system. Electrodes in the shock waveguide can be activated using at least one packet comprising multiple sub-pulses. The multiple sub-pulses within the packet can be delivered rapidly and continuously (e.g., at frequencies from 100 Hz to 10 kHz, pulse width durations of 1 ps or less, and / or peak power of 250 kW or higher). The packet can be delivered in bursts at frequencies from, for example, 1 Hz to 4 Hz. The time between adjacent sub-pulses can be less than the time between adjacent packets. Sub-pulses can be delivered at higher peak power (lower energy) compared to non-burst pulses. The voltage of the sub-pulses can be applied using a single-stage or multi-stage generator circuit. The shock waveguide can be operated in burst mode and / or non-burst mode.

Description

[0001] Cross-reference to related applications This application claims the benefit of U.S. Nonprovisional Application No. 18 / 595,148, filed March 4, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates generally to the field of medical devices and methods, and more specifically to shock wave catheter devices for treating calcified lesions in body cavities, such as calcified lesions and occlusions in the vascular system and kidney stones in the urinary system. Background Technology

[0003] Various catheters have been developed for treating calcified lesions, such as those in the vascular system associated with arterial disease. For example, treatment systems used in percutaneous coronary angioplasty or peripheral angioplasty use an angioplasty balloon to dilate the calcified lesion and restore normal blood flow to the vessel. In these types of procedures, a catheter carrying a balloon is advanced along a guidewire into the vascular system until the balloon is aligned with the calcified plaque. The balloon is then inflated (typically greater than 10 atm) to push the calcified plaque back into the vessel wall and dilate the occluded area of ​​the vascular system.

[0004] Recently, techniques and treatments for intravascular lithotripsy (IVL) have been developed, which is an interventional procedure used to improve calcified plaques in diseased arteries. The mechanism of plaque improvement is achieved through the use of a catheter with one or more acoustic shock wave generating sources located within a fluid that can generate acoustic shock waves to improve calcified plaques. IVL devices vary in design regarding the energy source used to generate the acoustic shock waves, with two exemplary energy sources being electrohydraulic generation and laser generation.

[0005] For electrohydraulic generation of acoustic shock waves, a conductive solution (e.g., saline) can be contained within a housing surrounding the electrodes or flushed through a tube surrounding the electrodes. Improvement of calcified plaques is achieved by generating acoustic shock waves within the catheter through a transelectrode discharge. The energy from this discharge enters the surrounding fluid faster than the speed of sound, thus generating acoustic shock waves. Furthermore, the energy generates one or more rapidly expanding and bursting vapor bubbles, which generate secondary shock waves. These shock waves propagate radially outward and improve calcified plaques within the blood vessel. For laser-generated acoustic shock waves, a laser pulse is transmitted into the fluid within the catheter and absorbed by the fluid. This absorption process rapidly heats the fluid and causes it to evaporate, thereby generating rapidly expanding and bursting vapor bubbles and acoustic shock waves that propagate outward and improve calcified plaques. If a fluid exhibiting strong absorption at the laser wavelength used is selected, the intensity of the acoustic shock waves is higher. These examples of IVL devices are not intended to comprehensively list all potential energy sources for generating IVL shock waves.

[0006] IVL (intravascular coagulation) can be considered different from standard atherosclerotic plaque resection because it breaks up calcifications but does not release them from the tissue. Therefore, IVL generally does not require aspiration or embolization protection. Furthermore, due to the compliance of normal vessels and non-calcified plaques, the shock wave generated by IVL does not alter normal vascular tissue or non-calcified plaques. In addition, IVL does not carry the same risks of perforation, anatomical changes, or other damage to the vascular system as atherosclerotic resection or angioplasty using cutting or scribing balloons.

[0007] More specifically, catheters for delivering IVL treatments have been developed that include electrode pairs for electrohydraulically generating shock waves within an angioplasty balloon. Shock wave devices can be particularly effective for treating calcified plaque lesions because the acoustic pressure from the shock waves can rupture or destroy the lesion near the angioplasty balloon without damaging surrounding tissue. In these devices, the catheter is advanced over a guidewire through the patient's vascular system until it is positioned proximal to and / or aligned with the calcified plaque lesion in the body cavity. The balloon is then inflated with a conductive fluid (using a relatively low pressure of 2 atm to 4 atm) to inflate it to contact the lesion, but the inflation pressure is insufficient to substantially displace the lesion. Voltage pulses can then be applied across the electrodes in the electrode pair to generate an acoustic shock wave that propagates through the wall of the angioplasty balloon into the lesion. Once the acoustic shock wave ruptures the lesion, the balloon can be further inflated to increase the cross-sectional area of ​​the lumen and improve blood flow within the lumen. Alternative devices for delivering IVL treatment can be located within a closed volume (such as a cap, various compliant balloons, or other housings) other than angioplasty balloons.

[0008] Voltage pulses can be non-burst pulses applied across the electrodes of a transelectrode pair and can effectively generate shock waves to treat, for example, calcified lesions. A conductive solution (e.g., saline) can be contained within a housing surrounding the electrodes or flushed through a tube surrounding the electrodes. Acoustic shock waves can be generated within the catheter via transelectrode discharge. These shock waves propagate radially outward and improve calcified plaques. In some embodiments, laser generation of acoustic shock waves is used, where laser pulses are transmitted into a fluid within the catheter and absorbed by that fluid. This absorption process rapidly heats the fluid and causes it to evaporate, thereby generating rapidly expanding vapor bubbles and acoustic shock waves that propagate outward and improve calcified plaques. More efficient techniques for delivering shock wave therapy may be required. Summary of the Invention

[0009] This document describes systems and methods for applying one or more voltages to electrodes across a shock wave duct system. Electrodes in a shock wave duct can be activated using at least one packet comprising multiple sub-pulses. The multiple sub-pulses within a packet can be delivered rapidly and continuously (e.g., at frequencies from 100 Hz to 10 kHz), and the packet can be delivered in bursts. In some embodiments, the time between adjacent sub-pulses can be less than the time between adjacent packets. For example, a packet can have a frequency from 1 Hz to 4 Hz. Embodiments of this disclosure may include applying sub-pulses with higher peak power (but lower energy) to the electrodes of the shock wave duct system compared to non-burst pulses.

[0010] A method for generating one or more shock waves in a shock wave catheter system is disclosed. The method includes: applying a first voltage to one or more electrodes of the shock wave catheter system to generate one or more bubbles in a fluid surrounding the one or more electrodes; and applying at least one packet of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein: each packet of the at least one packet includes a plurality of sub-pulses, and at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz; wherein the one or more second voltages are different from the first voltage. Additionally or alternatively, in some embodiments, the properties of the plurality of sub-pulses are based on the properties of calcifications and / or tissue treated by the shock wave catheter system, wherein the properties of the calcifications and / or tissue include hardness, thickness, acoustic properties, or combinations thereof. Additionally or alternatively, in some embodiments, the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within the at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the frequency of the plurality of sub-pulses, the amplitude of the electrical pulse, the acoustic output, or combinations thereof. Additionally or alternatively, in some embodiments, the number of the plurality of sub-pulses is greater than or equal to 10. Additionally or alternatively, in some embodiments, the at least one packet has a duration of 20 µs or longer, a duty cycle of 50%, or both. Additionally or alternatively, in some embodiments, the plurality of packets have frequencies between 1 Hz and 4 Hz, wherein the plurality of packets includes the at least one packet. Additionally or alternatively, in some embodiments, the frequency of the plurality of sub-pulses is 100 times the frequency of the plurality of packets, wherein the plurality of packets includes the at least one packet. Additionally or alternatively, in some embodiments, the method further includes applying one or more third voltages during one or more inactive sub-pulse periods between the plurality of sub-pulses. Additionally or alternatively, in some embodiments, the power level of the one or more inactive sub-pulse periods is 50% or less of the power level of the plurality of sub-pulses. Additionally or alternatively, in some embodiments, the peak power of the at least one sub-pulse is 250 kW or higher.

[0011] A shockwave catheter system is disclosed. The shockwave catheter system includes: one or more electrodes; a fluid surrounding the one or more electrodes; a first voltage source configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; and a second voltage source configured to apply at least one packet of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the at least one packet includes a plurality of sub-pulses, wherein at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz. Additionally or alternatively, in some embodiments, the shockwave catheter system further includes: a controller configured to control the properties of the plurality of sub-pulses based on the properties of the calcifications and / or tissue treated by the shockwave catheter system, wherein the properties of the calcifications and / or tissue include hardness, thickness, acoustic properties, or combinations thereof. Additionally or alternatively, in some embodiments, the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within the at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the electrical pulse amplitude, the acoustic output, or a combination thereof. Additionally or alternatively, in some embodiments, the number of the plurality of sub-pulses is greater than or equal to 10. Additionally or alternatively, in some embodiments, the at least one packet has a duration of 20 µs or longer, a duty cycle of 50%, or both. Additionally or alternatively, in some embodiments, the plurality of packets have frequencies between 1 Hz and 4 Hz, wherein the plurality of packets includes the at least one packet. Additionally or alternatively, in some embodiments, the first voltage source is a low-power voltage source, and the second voltage source is a high-power voltage source. Additionally or alternatively, in some embodiments, the one or more electrodes comprise electrode pairs separated by an electrode gap, and the one or more second voltages are applied across the electrode gap.

[0012] A method for generating one or more shock waves in a shock wave duct system is disclosed. The method includes: applying a first voltage to one or more electrodes of the shock wave duct system to generate one or more bubbles in a fluid surrounding the one or more electrodes; and applying a plurality of sub-pulses of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the plurality of sub-pulses have a frequency greater than 10 Hz.

[0013] A shock waveguide system is disclosed. The shock waveguide system includes: one or more electrodes; a fluid surrounding the one or more electrodes; a first voltage source configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; and a second voltage source configured to apply a plurality of sub-pulses of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the plurality of sub-pulses have a frequency greater than 10 Hz.

[0014] A method for generating one or more shock waves in a shock wave duct system is disclosed. The method includes: applying a first voltage to one or more electrodes of the shock wave duct system to generate one or more bubbles in a fluid surrounding the one or more electrodes; and applying one or more packets of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the packets have a frequency greater than 1 Hz, and wherein the packets of applying the one or more second voltages include: for each packet, applying a plurality of sub-pulses of the one or more second voltages to the one or more electrodes.

[0015] A shock waveguide system is disclosed. The shock waveguide system includes: one or more electrodes; a fluid surrounding the one or more electrodes; a first voltage source configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; and a second voltage source configured to apply multiple packets of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the multiple packets have a frequency greater than 1 Hz, and wherein the multiple packets of the one or more second voltages applied by the second voltage source include: for each of the multiple packets, applying multiple sub-pulses of the one or more second voltages to the one or more electrodes.

[0016] A method for operating a shock waveguide system is disclosed. The method includes: applying a first voltage to one or more electrodes of the shock waveguide system to generate one or more bubbles in a fluid surrounding the one or more electrodes; charging an energy storage capacitor using a second voltage source; charging a sub-pulse capacitor using the energy storage capacitor; and delivering energy stored in the sub-pulse capacitor to the one or more electrodes for a plurality of sub-pulses included in a package to generate one or more electric arcs at the one or more electrodes.

[0017] A circuit is disclosed. The circuit includes: a first voltage source configured to apply a first voltage to one or more electrodes of a shock waveguide system to generate one or more bubbles in a fluid surrounding the one or more electrodes; a second voltage source configured to apply a second voltage; an energy storage capacitor coupled to the second voltage source and configured to store charge from the second voltage source; and a sub-pulse capacitor coupled to the energy storage capacitor, wherein the sub-pulse capacitor is configured to store charge from the energy storage capacitor and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes.

[0018] A shock waveguide system is disclosed. The shock waveguide system includes: one or more electrodes; a fluid surrounding the one or more electrodes; a first voltage source configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; a second voltage source configured to apply a second voltage; an energy storage capacitor coupled to the second voltage source and configured to store charge from the second voltage source; and a sub-pulse capacitor coupled to the energy storage capacitor, wherein the sub-pulse capacitor is configured to store charge from the energy storage capacitor and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes.

[0019] A method for operating a shock waveguide system is disclosed. The method includes: applying a first voltage to one or more electrodes of the shock waveguide system to generate one or more bubbles in a fluid surrounding the one or more electrodes; charging a capacitor using a second voltage source; and delivering energy stored in the capacitor to the one or more electrodes for a plurality of sub-pulses included in a package to generate one or more electric arcs at the one or more electrodes, wherein at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz.

[0020] A circuit is disclosed. The circuit includes: a first voltage source configured to apply a first voltage to one or more electrodes of a shock waveguide system to generate one or more bubbles in a fluid surrounding the one or more electrodes; a second voltage source configured to apply a second voltage comprising a plurality of sub-pulses; and a capacitor coupled to the second voltage source, wherein the capacitor is configured to store charge from the second voltage source and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz.

[0021] A shock waveguide system is disclosed. The shock waveguide system includes: one or more electrodes; a fluid surrounding the one or more electrodes; a first voltage source configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; a second voltage source configured to apply a second voltage comprising a plurality of sub-pulses; and a capacitor coupled to the second voltage source, wherein the capacitor is configured to store charge from the second voltage source and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz.

[0022] A method for treating lesions in a body cavity is disclosed. The method includes: advancing a shockwave catheter through the body cavity to the lesion; and applying a voltage pulse packet comprising a plurality of sub-pulses delivered at a frequency of at least 10 Hz, wherein each of the plurality of sub-pulses generates a shock wave. Additionally or alternatively, in some embodiments, the properties of the plurality of sub-pulses are based on the properties of the calcifications and / or tissue treated by the shockwave catheter, wherein the properties of the calcifications and / or tissue include hardness, thickness, acoustic properties, or combinations thereof. Additionally or alternatively, in some embodiments, the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within the at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the frequency of the plurality of sub-pulses, the electrical pulse amplitude, the acoustic output, or combinations thereof. Additionally or alternatively, in some embodiments, the number of the plurality of sub-pulses is greater than or equal to 10. Additionally or alternatively, in some embodiments, the packet has a duration of 20 µs or longer, a duty cycle of 50%, or both. Additionally or alternatively, in some embodiments, the plurality of packets have frequencies between 1 Hz and 4 Hz, wherein the plurality of packets includes the packet. Additionally or alternatively, in some embodiments, the frequencies of the plurality of sub-pulses are 100 times the frequencies of the plurality of packets, wherein the plurality of packets includes the packet. Additionally or alternatively, in some embodiments, the method further includes applying one or more second voltages during one or more inactive sub-pulse periods between the plurality of sub-pulses. Additionally or alternatively, in some embodiments, the power level of the one or more inactive sub-pulse periods is 50% or less of the power level of the plurality of sub-pulses. Additionally or alternatively, in some embodiments, the peak power of at least one of the plurality of sub-pulses is 250 kW or higher.

[0023] A shock waveguide system is disclosed. The shock waveguide system includes: one or more electrodes; a fluid surrounding the one or more electrodes; and one or more voltage sources configured to apply one or more voltages to the one or more electrodes according to an operating mode, wherein the operating mode includes burst mode operation and non-burst mode operation, wherein the burst mode operation includes at least one packet applying one or more voltages to the one or more electrodes, each packet comprising a plurality of sub-pulses, and at least one of the plurality of sub-pulses having a duration of 1 µs or less, or the frequency of the plurality of sub-pulses being between 100 Hz and 10 kHz.

[0024] A method for operating a shock waveguide system is disclosed. The method includes: operating the shock waveguide system in a burst mode, wherein the burst mode operation includes at least one packet of applying one or more voltages to one or more electrodes of the shock waveguide system, wherein: each packet of the at least one packet includes a plurality of sub-pulses, and at least one of the plurality of sub-pulses has a duration of 1 µs or less, or the frequency of the plurality of sub-pulses is between 100 Hz and 10 kHz; and operating the shock waveguide system in a non-burst mode. Attached Figure Description

[0025] The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 A side view of an exemplary angioplasty balloon catheter according to some implementation schemes is shown.

[0026] Figure 2 A side view of an example electrode electrically coupled to a voltage source according to some implementation schemes is shown.

[0027] Figure 3 Examples of internal and external electrodes according to some implementation schemes are illustrated.

[0028] Figure 4 Exemplary simplified equivalent circuit diagrams according to some implementation schemes are illustrated.

[0029] Figure 5 Exemplary graphs of pulses applied to electrodes and the resulting current flowing through electrodes according to some embodiments are shown.

[0030] Figure 6A An example packet comprising multiple sub-pulses delivered rapidly and continuously, according to some implementation schemes, is shown in an unfolded diagram.

[0031] Figure 6B Exemplary graphs of multiple sub-pulses (top) and non-burst pulses (bottom) according to some implementation schemes are shown.

[0032] Figure 7 An exemplary graph is shown that compares a non-burst (non-packet) pulse (top) with multiple sub-pulses (bottom) according to some implementation schemes.

[0033] Figure 8A Examples of power and energy (area under the power vs. time curve) comparisons for non-burst pulses and packets including sub-pulses are illustrated according to some implementation schemes.

[0034] Figure 8BExamples of power and energy comparisons for non-burst pulses and packets including sub-pulses are illustrated according to some implementation schemes.

[0035] Figure 9 A schematic diagram of an example bipolar generator circuit according to some implementation schemes is shown.

[0036] Figure 10 An exemplary flowchart illustrating burst mode operation of an IVL catheter according to some implementation schemes is shown.

[0037] Figure 11 A graph illustrating exemplary burst mode operation of a multi-stage generator circuit for a package according to some embodiments is shown.

[0038] Figure 12 Graphs illustrating exemplary charging modes and sub-pulse modes according to some implementation schemes are shown.

[0039] Figure 13 Exemplary subpulses according to some implementation schemes are illustrated.

[0040] Figure 14 A simplified schematic diagram of an example single-stage generator circuit according to some implementation schemes is shown.

[0041] Figure 15 A graph illustrating exemplary burst mode operation of a single-stage generator circuit for a package according to some embodiments is shown.

[0042] Figure 16 Exemplary subpulses according to some implementation schemes are illustrated.

[0043] Figure 17 Examples of computing systems based on some implementation schemes are shown. Detailed Implementation

[0044] The following description is intended to enable those skilled in the art to make and use the various embodiments and aspects disclosed herein. Descriptions of specific devices, components, techniques, and applications are provided by way of example only. Various modifications to the examples described herein will be apparent to those skilled in the art, and the general principles described herein can be applied to other examples and applications without departing from the spirit and scope of its various embodiments and aspects. Therefore, its various embodiments and aspects are not intended to be limited to the examples described and illustrated herein, but are consistent with the scope of the claims.

[0045] Efforts have been made to improve the design of electrode assemblies included in shock wave and directional cavitation catheters. For example, low-profile electrode assemblies have been developed that reduce the cross-sectional profile of the catheter and allow the catheter to more easily navigate calcified vessels to deliver shock waves in more severely occluded areas of the vascular system. Examples of low-profile electrode designs can be found in U.S. Patents 8,888,788, 9,433,428, and 10,709,462, and U.S. Publication No. 2021 / 0085383, all of which are incorporated herein by reference. Other catheter designs have improved shock wave delivery, for example, by specifically constructing and configuring the electrode to guide the shock wave in an anterior direction to disrupt tighter and more difficult-to-penetrate occlusions in the vascular system. Examples of forward-firing conduit designs can be found in U.S. Patent Nos. 10,966,737, 11,478,261, and 11,596,423, and U.S. Publications Nos. 2023 / 0107690 and 2023 / 0165598, all of which are incorporated herein by reference. Efforts to improve electrode assembly life include switching or alternating the polarity of voltage sources. Examples of polarity switching in shock wave devices can be found in U.S. Patent No. 10,226,265, which is incorporated herein by reference.

[0046] In the following description of various embodiments, reference is made to the accompanying drawings, which illustrate specific implementation methods that can be practiced. It should be understood that other embodiments and examples, and changes, may be implemented without departing from the scope of this disclosure.

[0047] Furthermore, in the following description, it should be understood that, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the / described” used in the following description are intended to also include the plural forms. It should also be understood that, as used herein, the term “and / or” refers to and covers any and all possible combinations of one or more of the associated listed items. It should also be understood that, when used herein, the terms “comprising” and / or “including” specify the presence of the stated feature, integer, step, operation, element, component, and / or unit, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, units, and / or groups thereof. As provided herein, it should be understood that any disclosure describing a range of values ​​for dimensions or measurements such as thickness, length, weight, time, frequency, temperature, voltage, current, angle, etc., includes any numerical increments or gradients relative to the range stated for a given dimension or measurement.

[0048] Figure 1A side view of an exemplary angioplasty balloon catheter according to some embodiments is illustrated. The catheter 20 includes an elongated carrier, such as a hollow sheath 21, an inflatable balloon 26 formed around and sealed thereto within the sheath 21, and a guidewire member 28 to which the balloon 26 is sealed at a sealing portion 23. The guidewire member 28 may have a longitudinal lumen 29 through which a guidewire (not shown) can be received for guiding the catheter 20 to a desired location, such as within a vein or artery.

[0049] The sheath 21 and guidewire member 28 form a channel 27 through which fluid can enter the balloon 26 to inflate it. The balloon 26 can be filled with water, saline, a mixed saline solution, etc., allowing the balloon to be compliantly positioned along the wall of an artery or vein, for example, in close proximity to a calcified lesion. The fluid may also contain an X-ray contrast agent to allow for fluoroscopic visualization of the catheter during use. The channel 27 is in fluid communication with the electrode pair 25 and provides the conductive fluid required for current flow across the electrode gap of the electrode pair 25 and subsequent shock wave generation. The electrode pair 25 may include electrodes 22 and 24 located within the fluid-filled balloon 26.

[0050] although Figure 1 An intravascular lithotripsy (IVL) angioplasty balloon catheter is illustrated and the corresponding description is specific to intravascular lithotripsy (IVL) angioplasty balloon catheters; however, embodiments of this disclosure are applicable to other types of IVL where a balloon may or may not be used. Additionally or alternatively, embodiments of this disclosure may include multiple electrode pairs 25.

[0051] In some embodiments, the IVL catheter is a so-called "rapid-exchange" ("Rx") catheter, which has an opening through which a guidewire is guided (e.g., through the middle portion of the central tube in the longitudinal direction). In other embodiments, the IVL catheter may be an "integral guidewire" ("OTW") catheter, wherein the guidewire lumen is formed throughout the entire length of the catheter, and the guidewire is guided through the proximal end of the hub.

[0052] like Figure 2 As shown, electrodes 22 and 24 can be electrically coupled to source 40 (e.g., a voltage source). Electrodes 22 and 24 can be electrically coupled to source 40 via, for example, a connector. In some embodiments, source 40 can be a high-voltage power source (HVPS). Source 40 can apply one or more voltages to electrodes 22, 24, or both to generate one or more electric arcs at the electrodes.

[0053] like Figure 3 As can be seen, electrodes 22 and 24 are coaxially arranged, with electrode 22 being the inner electrode and electrode 24 being the outer electrode. (Return to reference) Figure 2The inner electrode 22 can be coupled to the positive terminal 44 of the source 40, and the outer electrode 24 can be coupled to the negative terminal 46 of the source 40. In some aspects, the system can employ polarity switching, wherein the inner electrode 22 can be coupled to the negative terminal 46 of the source, and the outer electrode 24 can be coupled to the positive terminal 44 of the source 40. Electrodes 22 and 24 can be formed of metal (such as stainless steel) or another conductive material. Electrodes 22 and 24 can be spatially spaced to allow for the formation of a reproducible arc for a given applied voltage and current.

[0054] An electric arc between electrodes 22 and 24 in the fluid is used to generate a shock wave in the fluid (within channel 27). High-voltage pulses applied to electrodes 22 and 24 can form an arc across electrodes 22 and 24. Once catheter 20 is positioned at the lesion site via a guidewire (not shown), a physician or operator can begin (e.g., by pressing a button on the catheter control system) to apply pulses to electrodes 22 and 24 to generate a shock wave that ruptures the calcified plaque. This shock wave can propagate through the fluid, through balloon 26, through the blood, and through the vessel wall to the calcified lesion, where the energy can break down the hardened plaque without the balloon applying excessive pressure to the arterial wall.

[0055] Device 200 may include multiple electrode pairs along the length of balloon 26. A shockwave device having multiple shockwave electrode pairs at different locations (circumferential and / or longitudinal) can help deliver a consistent or uniform force to a tissue region. The electrode pairs may be electrically coupled in series or parallel.

[0056] As used herein, the term "electrode" refers to a conductive element (typically made of metal) that receives current and subsequently releases it to another conductive element. In the context of this disclosure, electrodes are typically positioned relative to each other, such as in an arrangement of inner and outer electrodes. Thus, as used herein, the term "electrode pair" refers to two electrodes positioned adjacent to each other and spaced apart, such that applying a sufficiently high voltage to the electrode pair will cause current to be transmitted across the gap between the two electrodes (also known as a "spark gap") (e.g., from the inner electrode to the outer electrode and vice versa, optionally where the electricity is transmitted through a conductive fluid or gas between them). In some contexts, one or more electrode pairs may also be referred to as an electrode assembly. In the context of this disclosure, the term "emitter" broadly refers to a region of the electrode assembly in which current is transmitted across the electrode pair, thereby generating a shock wave. The terms "emitter sheath" and "emitter strip" refer to continuous or discontinuous strips of conductive material that may form one or more electrodes of one or more electrode pairs, thereby forming the location of one or more emitters.

[0057] Figure 4An exemplary simplified equivalent circuit diagram according to some embodiments is illustrated. The circuit may include a capacitor 50 storing a voltage Vc. A switch 60 may be closed, thereby allowing a voltage drop across electrodes 22 and 24.

[0058] Figure 5 An exemplary graph illustrating the pulses applied to electrodes 22 and 24 according to some embodiments and the resulting current flowing through electrodes 22 and 24 is shown. Switch 60 may initially close at time T1. At time T1, the voltage is low, and closing switch 60 causes the voltage across electrodes 22 and 24 to rise rapidly to voltage level 70. During this time, the current 72 flowing through electrodes 22 and 24 is relatively low. After a residence time Td, an electric arc is generated across electrodes 22 and 24 when the voltage across electrodes 22 and 24 reaches the breakdown voltage of the liquid between electrodes 22 and 24. After a residence time Td, at time T2, the electric arc causes a high current 72 to begin flowing through electrodes 22 and 24, and plasma is formed between electrodes 22 and 24. This plasma rapidly heats the liquid and generates a shock wave because energy is transferred to the liquid faster than the speed of sound. Furthermore, the energy transfer to the liquid rapidly heats the fluid and causes it to evaporate, thus forming vapor bubbles. The bubbles expand and are then cooled by the denser surrounding liquid and eventually burst. If the bubble is allowed to grow to its equilibrium size without obstruction, its bursting may trigger a second acoustic pulse and the emission of a water jet. This water jet is generated by the collision of the dense liquid with the walls when the bubble bursts completely.

[0059] In some cases, calcified lesions may require high voltages (sometimes as high as 10 to 15 atm or even 20 atm) to break up the calcified plaques and push them back into the vessel wall. The system includes a pulse generator coupled to the proximal end of an insulated wire that supplies one or more voltages to a shock wave generator. When a voltage is applied across the electrode pair via the pulse generator, each pulse initially ionizes the conductive fluid inside balloon 26 to generate microbubbles around the shock wave generator, which insulate the electrodes. Subsequently, a plasma arc forms between the electrodes in the electrode pair, creating a low-impedance path for free current flow. Heat from the plasma arc heats the conductive fluid to generate rapidly expanding vapor bubbles. The expansion and rupture of these vapor bubbles generate a shock wave (cavitation wave) that radiates outward through balloon 26 and then through the blood to the calcified lesion near balloon 26.

[0060] In some implementations, at least one packet comprising multiple sub-pulses (also known as a burst pulse, operated in burst mode) can be used to activate the electrodes in the catheter. Figure 6A and Figure 6BExemplary graphs of multiple sub-pulses (top) and non-burst pulses (bottom) according to some embodiments are illustrated. The duration of sub-pulse 702 may be less than the duration of non-burst pulse 52, as shown. Sub-pulses 702 within packet 704 may be delivered rapidly and continuously (e.g., at frequencies from 100 Hz to 10 kHz). Packet 704 may be delivered in bursts. A method of generating a shock wave in a shock wave duct system includes applying multiple sub-pulses 702 within packet 704. In some aspects, sub-pulses 702 generate shock waves. The time between adjacent sub-pulses 702 (inactive sub-pulse period (time between the end of a sub-pulse and the start of an adjacent sub-pulse)) may be less than the time between adjacent packets 704 (inactive packet period (time between the end of a packet and the start of an adjacent packet)).

[0061] The frequency of the sub-pulse 702 within package 704 and / or the frequency of package 704 can be determined based on the properties of the calcifications and / or tissue affected by the catheter system. For example, when treating soft materials, a higher (increased) frequency (of sub-pulse 702 or package 704) can be used. Additionally or alternatively, when treating soft materials, other properties such as the number of sub-pulses 702 within package 704, the duration of sub-pulses 702, the peak power of sub-pulses 702, the amplitude of electrical pulses, and / or the acoustic output can be adjusted. In some examples, embodiments of this disclosure include changing the frequency of the sub-pulses 702 within package 704. Additionally or alternatively, the frequency of package 704 can be varied. In some embodiments, the properties of the sub-pulses 702 (e.g., the number of sub-pulses 702 within package 704, the duration of at least one sub-pulse 702, the peak power of at least one sub-pulse 702, the frequency of sub-pulses 702, the amplitude of electrical pulses, the acoustic output, etc.) can be determined based on the properties of the calcifications and / or tissue affected (treated) by the catheter system. For example, the properties of sub-pulses and / or packets can be determined based on the hardness, thickness, acoustic properties (e.g., acoustic impedance) of the calcification / tissue. The controller (e.g., Figure 9 The controller 990 can be configured to control the properties of the sub-pulse 702.

[0062] Figure 7 An exemplary graph comparing a non-burst (non-packet) pulse 52 (top) with multiple sub-pulses 702 (bottom) according to some embodiments is illustrated. The non-burst pulse 52 (top) may comprise a single pulse with a pulse width of 1 µs, activated at a repetition rate of 250 ms to 1000 ms. The non-burst pulse may have an amplitude as low as 500 volts or in the range of 1000 volts to 10,000 volts. The energy pulse may be delivered at a slow frequency (e.g., 1 Hz to 4 Hz).

[0063] Package 704 (bottom) may include multiple sub-pulses 702. In some embodiments, sub-pulses 702 may have a duration (pulse width) of 1 µs or less. For example, package 704 may have a duration of 20 µs (or longer) and a duty cycle of 50%. In some embodiments, package 704 includes 10 sub-pulses 702. In some embodiments, package 704 may be activated at a repetition rate of 250 ms to 1000 ms (inactive package period). A first sub-pulse 702A may break up an initial amount of calcification, and additional sub-pulses 702B, 702C, etc., may further break up the calcification.

[0064] Package 704 may include a plurality of rapidly and continuously delivered sub-pulses 702. For example, package 704 may include 24 sub-pulses 702. In some embodiments, package 704 may have a frequency similar to pulse 52 (e.g., a frequency of 1 Hz to 4 Hz). In some embodiments, the frequency of sub-pulses 702 may be at least 100 times the frequency of pulse 52 or package 704.

[0065] Compared to the peak power and energy of the non-burst pulse 52, the sub-pulse 702 can have a higher peak power but lower energy. Therefore, for a given average power, the sub-pulse 702 requires less energy than the non-burst pulse 52. Figure 8A An example comparison of power and energy (area under the power vs. time curve) for a non-burst pulse 52A and a packet 704 including sub-pulse 702 is illustrated. As shown, sub-pulse 702 of packet 704 can include the same peak power as the non-burst pulse 52A. For a given amount of time (e.g., 0.5 seconds), the energy delivered for packet 704 can be less than the energy delivered for the non-burst pulse 52A (e.g., half of it). For the same amount of delivered energy, packet 704 delivering sub-pulse 702 may require a much longer time than delivering the non-burst pulse 52A.

[0066] Figure 8B An example comparison of power and energy is illustrated for a non-burst pulse 52B and a packet 704 including a sub-pulse 702. As shown, the sub-pulse of packet 704 can include a higher peak power 811 than the non-burst pulse 52B, where the same amount of energy can be delivered in the same amount of time.

[0067] Return to reference Figure 7Sub-pulse 702A may have a peak power 706A and a duration 708A. The duration 708A may be shorter than the duration 718 of the non-burst pulse 52. In some embodiments, the average power of sub-pulse 702 in package 704 may be substantially the same as the average power of the non-burst pulse 52. The time between adjacent sub-pulses (e.g., sub-pulses 702A and 702B) may be referred to as an inactive sub-pulse period 705A. During the inactive sub-pulse period, the power may be reduced to an inactive sub-pulse power level 726. One or more inactive sub-pulse voltages may be applied. In some embodiments, the system may not apply one or more voltages during the inactive sub-pulse period. The inactive sub-pulse power level 726 may be less than the peak power 706A; for example, the inactive sub-pulse power level 726 may be 30%, 40%, 50%, etc. (including an inactive power level of 0 watts) of the peak power 706A. The peak power 706A may be higher than the peak power 716 of the non-burst pulse 52. In some implementations, the peak power 706A of the sub-pulse 702A can be 250kW or higher.

[0068] The higher peak power 706 of sub-pulse 702 can cause faster arc formation across electrodes 22 and 24, which can lead to faster bubble generation. A burst of sub-pulse 702 with a shorter pulse duration 708 can have the same energy but is delivered over a shorter time (e.g., within the duration of packet 704), resulting in faster and more effective treatment. In some cases, higher frequencies of sub-pulse 702 (e.g., 100 Hz to 10 kHz) can also produce more effective treatment, particularly when treating soft materials such as soft tissue.

[0069] Examples of this disclosure include shockwave catheter systems configured to operate in burst mode and non-burst mode. The catheter system can switch between burst mode and non-burst mode operation. In some aspects, in burst mode operation, multiple subpulses within a package are rapidly and continuously delivered, for example, having frequencies from 100 Hz to 10 kHz, durations of 1 µs or less, peak power of at least 250 kW, or combinations thereof. In some aspects, in non-burst mode operation, packages are delivered, for example, having frequencies from 1 Hz to 4 Hz, durations longer than 20 µs, peak power less than 250 kW, or combinations thereof. The catheter system may include user control inputs that allow the user to select an operating mode. For example, the user can select burst mode operation when treating a first material and then switch to non-burst mode operation when treating a second material. In some examples, the first material may differ from the second material, such as the first material being a softer tissue than the second material. In this way, the catheter system can be able to deliver more effective treatment by selectively targeting different types of tissue using different operations.

[0070] The embodiments disclosed herein include burst mode operation using multi-stage generator circuitry. Figure 9 A schematic diagram of a circuit for burst mode operation of an IVL catheter according to some embodiments is illustrated. The circuit includes a sub-pulse capacitor C2, an energy storage capacitor C1, and a source 40. Capacitor C1 may be an energy storage capacitor storing energy for packet 704 (burst energy delivery), and capacitor C2 may be a sub-pulse capacitor storing and delivering energy for one or more sub-pulses 702. In some aspects, the capacitance of the energy storage capacitor C1 may be greater than the capacitance of the sub-pulse capacitor C2 (e.g., the capacitance of C1 may be more than twice the capacitance of C2). Source 40 may charge capacitor C1, which is electrically coupled to source 40. Sub-pulse capacitor C2 may be configured to store and deliver energy for one or more (e.g., each) sub-pulses 702. Electrodes of transmitter 925 are coupled to capacitor C1, and electrodes of transmitter 925 are coupled to transistor 972. When coupled via transistor 972, source 942 provides a low voltage to transmitter 925. The energy of the sub-pulse 702 can be delivered across the transmitter 925 (the region of the electrode assembly where current is transmitted across electrode pair 25) to generate a shock wave. The circuitry includes a transistor 972 that can couple electrode 24 of the transmitter 925 to a sensing resistor 974 based on a pulse signal 970. The resistance of resistor 974 limits the charging current used to charge capacitor C1. Coupling electrode 24 to the sensing resistor 974 (e.g., when pulse signal 970 is high) can cause a voltage drop across electrodes 22 and 24 for pulse generation. Applying a high voltage to electrode pair 25 can allow current to be transmitted across the spark gap of conduit 20.

[0071] In some embodiments, the operation of the circuit may include multiple operating modes, including a sub-pulse mode and a charging mode. In some embodiments, the conduit may operate in sub-pulse mode and charging mode at different times. In sub-pulse mode, energy from sub-pulse capacitor C2 is transferred to transmitter 925. In charging mode, energy storage capacitor C1 charges sub-pulse capacitor C2. The multi-stage generator circuit includes a switch 986 that is open during sub-pulse mode, thereby electrically decoupling energy storage capacitor C1 from transmitter 925, allowing source 40 to charge energy storage capacitor C1.

[0072] Switch 986 can be opened or closed depending on the operating mode. During sub-pulse mode, switch 986 can be open, and transmitter 925 can be electrically coupled to sub-pulse capacitor C2 and source 942. During charging mode, switch 986 can be closed, thereby electrically coupling source 40 to sub-pulse capacitor C2. Transistor 972 can be open during charging mode, thereby allowing source 40 to charge sub-pulse capacitor C2.

[0073] The inclusion of energy storage capacitor C1 and sub-pulse capacitor C2 helps reduce the amount of reduction in peak power for subsequent sub-pulses 702 within the package. Energy storage capacitor C1 is configured to provide energy to sub-pulse capacitor C2 during charging mode to help maximize the amount of energy stored in sub-pulse capacitor C2 before the start of sub-pulse 702, thereby allowing the energy delivered to transmitter 925 (during sub-pulse mode) to be close to or equal to the maximum energy storage capacity of sub-pulse capacitor C2 within more than one sub-pulse 702.

[0074] The sensing resistor 974 may be a current-sensing resistor coupled to the sensing amplifier 976. The sensing amplifier 976 may generate a sensing signal 968 when the current flowing through electrodes 22 and 24 of the transmitter 925 reaches a predetermined current limit (e.g., 10 amps to 100 amps). This sensing signal 968 may be a current signal sent to the controller 990 when a pulse has been detected. In some embodiments, the sensing resistor 974 may control the flow of current, thereby limiting the maximum peak output current. For example, the sensing resistor 974 may be a ballast resistor whose resistance changes based on the flow of current.

[0075] When demand requires more energy than is stored in the sub-pulse capacitor C2 and / or when energy delivery from source 40 alone is insufficient for energy delivery during a given sub-pulse 702, energy storage capacitor C1 can be configured to store energy, for example, for burst energy delivery. Source 40 can be coupled to energy storage capacitor C1 for charging energy storage capacitor C1. Energy storage capacitor C1 can also be coupled to ground. Switch 986 selectively couples energy storage capacitor C1 to sub-pulse capacitor C2 to transfer energy stored in energy storage capacitor C1 to sub-pulse capacitor C2 and / or transmitter 925. Controller 990 uses a charging signal 988 to control switch 986 such that switch 986 closes when sub-pulse capacitor C2 is being charged (charging mode). In some embodiments, switch 986 closes before each sub-pulse 702.

[0076] Controller 990 (e.g., a microprocessor, microcontroller, field-programmable gate array (FPGA), etc.) or other similar control circuitry (such as a gate array) controls the overall operation of the catheter system. Controller 990 may receive a button signal coupled to switch 992. In some embodiments, the button signal may be generated based on user control input (e.g., momentary button press) to control the delivery of sub-pulse 702 and / or package 704. For example, when the button signal is high (having a value greater than or equal to a threshold), a high voltage may be delivered to electrode pair 25, thereby closing the switch. The button signal may be high due to, for example, a user (physician, operator, etc.) pressing a button on the catheter system. In some embodiments, the high voltage may be delivered for a predetermined duration (e.g., the duration of package 704, the duration 708 of sub-pulse 702, etc.). In some embodiments, the high voltage may be delivered for a duration based on the duration of the button press. For example, when HV control signal 993 is low, controller 990 may stop the delivery of high voltage. When the predetermined duration has elapsed and the physician or operator no longer presses the button on the catheter system, the HV control signal 993 can be low (with a value less than the threshold).

[0077] Circuit 900 includes a source 942, which may be a low-voltage power source (LVPS). Source 942 may be used to bias emitter 925 to generate one or more bubbles, for example, in the fluid surrounding electrode 22, electrode 24, or both. In some embodiments, source 942 may keep the current flowing through emitter 925 low between adjacent sub-pulses 702 (inactive sub-pulse period 705A within package 704 when inactive sub-pulse power level 726 is applied to electrode pair 25). Source 942 may be coupled to a diode 944 to prevent pulse current from flowing through source 942 and a resistor 946 to limit the current from source 942. Source 942 may provide a low voltage based on an LV control signal 994 from controller 990.

[0078] Figure 10An exemplary flowchart illustrating burst-mode operation for IVL according to some embodiments is shown. At step 1002, the catheter system is in an initial state. In some embodiments, in the initial state, the physician or operator does not press a button, as indicated by a button signal to controller 990. Switch 986 is open, thereby preventing the energy storage capacitor C1 from discharging its stored charge (transferring energy to sub-pulse capacitor C2 and / or transmitter 925). Transistor 972, operating according to pulse signal 970, does not electrically couple transmitter 925 to sensing resistor 974. HV control signal 993 from controller 990 to source 40 indicates that source 40 should not provide power (e.g., HV control signal 993 is low), and LV control signal 994 from controller 990 to source 942 indicates that source 942 should not provide power (e.g., LV control signal 994 is low). No energy is supplied to the electrode pair of transmitter 925.

[0079] At step 1004, the catheter system can receive a button signal indicating button press from the physician or operator. In some embodiments, the button signal may be high when the physician or operator is pressing a button on the catheter system, and low when the physician or operator is not pressing the button. At step 1006, source 942 may apply a low voltage to transmitter 925, and at step 1008, the catheter system may wait for a period of time to generate bubbles. In some embodiments, in response to controller 990 sending a corresponding LV control signal 994 (e.g., LV control signal 994 is high), source 942 may apply a low voltage to electrodes 22 and 24 of transmitter 925.

[0080] At step 1010, the controller 990 may send an HV control signal 993 that causes the source 40 to output high power. For example, the HV control signal 993 may be high. The source 40 can provide high power to charge the energy storage capacitor C1.

[0081] The controller 990 can then close the switch 986 using the charging signal 988. Closing the switch 986 after the energy storage capacitor C1 has been charged can charge the sub-pulse capacitor C2 (step 1012). The controller 990 opens the switch 986 to stop charging the sub-pulse capacitor C2.

[0082] At step 1014, the energy stored in the sub-pulse capacitor C2 is applied to the transmitter 925. This stored energy can be applied via a pulse signal 970 from the controller 990, causing the transistor 972 to electrically couple the electrode 24 of the transmitter 925 to the sensing resistor 974. Power is applied to the transmitter 925 for the duration of the sub-pulse 702.

[0083] When a certain amount of current flows from transmitter 925 through transistor 972 and through sensing amplifier 976, sensing signal 968 is output to controller 990. Controller 990 outputs pulse signal 970, which causes transistor 972 to electrically decouple transmitter 925 and sensing resistor 974. This electrical decoupling between transmitter 925 and sensing resistor 974 stops applying energy to transmitter 925, thus returning to the inactive sub-pulse power level (step 1016).

[0084] At step 1018, it is determined whether all sub-pulses 702 of package 704 have been executed. If yes, the catheter system waits for an inactive package period (step 1020). If no, the catheter system repeats steps 1006 to 1016 for the next sub-pulse 702.

[0085] Figure 11 Exemplary burst mode operation graphs for a multi-stage generator circuit for a package, according to some embodiments, are illustrated. Multi-stage generator circuits may be more efficient than single-stage generator circuits in breaking up calcifications. Although... Figure 11 Package 704 is illustrated as comprising 10 sub-pulses 702, but embodiments of this disclosure may include any number of sub-pulses 702 within package 704.

[0086] Sub-pulses 702 in package 704 can have substantially the same peak power. For example, the first sub-pulse 702A can have a peak power of about 340 kW, the second sub-pulse 702B can have a peak power of about 340 kW, the third sub-pulse 702C can have a peak power of about 340 kW, and so on.

[0087] Figure 12 The graphs for exemplary charging modes and sub-pulse modes are illustrated, and Figure 13 Exemplary subpulse patterns according to some embodiments are illustrated. The multi-stage generator circuit can operate in multiple operating modes, such as charging mode 1204 and subpulse mode 1202. During charging mode 1204, ( Figure 9 The transistor 972 can be off, and ( Figure 9 The source 942 can be directed to ( Figure 9 The transmitter 925 applies a low voltage. Figure 9 Switch 986 is off, allowing ( Figure 9 The energy source 40 charges the energy storage capacitor C1.

[0088] During sub-pulse mode 1202, ( Figure 9 Switch 986 closes momentarily to charge sub-pulse capacitor C2. After sub-pulse capacitor C2 is charged, switch 986 is open, thus allowing sub-pulse capacitor C2 to charge ( Figure 9 The 925 transmitter provides power.

[0089] like Figure 13 As shown in the single sub-pulse, the circuit can operate in charging mode 1204 and sub-pulse mode 1202 at different times. In some embodiments, the duration of charging mode 1204 can be longer than the duration of sub-pulse mode 1202.

[0090] The embodiments disclosed herein include burst mode operation using a single-stage generator circuit. Figure 14 A simplified schematic diagram of a simulated example single-stage generator circuit according to some embodiments is illustrated. Compared to a single-stage generator circuit, a multi-stage generator circuit may include additional transistors and capacitors. For example, a single-stage generator circuit may not include the switch 986 or the sub-pulse capacitor C2.

[0091] Figure 15 A graph illustrating exemplary burst-mode operation of a single-stage generator circuit for a packet according to some embodiments is shown, and Figure 16 Exemplary subpulses according to some implementation schemes are illustrated. Although Figure 15 Package 704 is illustrated as comprising 10 sub-pulses 702, but embodiments of this disclosure may include any number of sub-pulses 702 within package 704, including 10 or more sub-pulses.

[0092] Within packet 704, the first sub-pulse 702A can have the highest peak power, and then the peak power of subsequent sub-pulses decreases. Stored in ( Figure 14 The amount of energy in capacitor C1 decreases for each sub-pulse as energy is transferred to transmitter 925. For example, the first sub-pulse 702A can have a peak power of approximately 340 kW (also...). Figure 15 As shown in the diagram, the second sub-pulse 702B can have a peak power of approximately 220 kW (the peak power of the second sub-pulse 702B can be less than the peak power of the first sub-pulse 702A), the third sub-pulse 702C can have a peak power of approximately 150 kW (the peak power of the third sub-pulse 702C can be less than the peak power of the second sub-pulse 702B), and so on. In some embodiments, the peak power can exhibit exponential decay over time and / or for subsequent sub-pulses 702 within package 704, such as... Figure 15 As shown.

[0093] The operation of a single-stage generator circuit can be similar to Figure 10 The operation is shown. In some embodiments, the operation of the single-stage generator may not include steps related to charging the capacitor, such as charging the energy storage capacitor in step 1010 and charging the sub-pulse capacitor in step 1012.

[0094] In some implementations, the multi-stage generator circuit can operate as a single stage or two stages. For example, ( Figure 14 The capacitor C1 can be initially charged at the beginning of package 704. Once capacitor C1 is charged, transistor Q1 can be configured to be disconnected for the remainder of package 704.

[0095] Although the shock wave device described herein is based on generating shock waves by applying a high voltage to electrodes, it should be understood that the shock wave device may additionally or alternatively include a laser and an optical fiber as a shock wave transmitter system, whereby the laser source delivers energy through the optical fiber and enters the fluid to form shock waves and / or cavitation bubbles.

[0096] The electrode assemblies and catheter devices described herein can be used to treat coronary artery occlusions, such as lesions in the vascular system, as well as various other occlusions, such as those in the peripheral vascular system (e.g., above the knee, below the knee, iliac bone, carotid artery, etc.). For further examples, similar designs can be used to treat soft tissues, such as cancers and tumors (i.e., non-thermal ablation methods), blood clots, fibromas, cysts, organs, scar and fibrotic tissue removal, or other tissue destruction and removal. Electrode assemblies and catheter designs can also be used for neurostimulation therapy, targeted drug delivery, treatment of tumors in body cavities (e.g., tumors in blood vessels, esophagus, intestines, stomach, or vagina), wound management, non-surgical removal and tissue destruction, or as an alternative to thermal treatment or cauterization for venous insufficiency and tubal ligation (i.e., for permanent female contraception).

[0097] In one or more examples, the electrode assemblies and conduits described herein can also be used in tissue engineering approaches, such as for mechanical tissue decellularization to produce a bioactive scaffold in which new cells (e.g., exogenous or endogenous cells) can replace old cells; introducing porosity to sites to improve cell retention, cell infiltration / migration, and diffusion of nutrients and signaling molecules, thereby promoting angiogenesis, cell proliferation, and tissue regeneration, similar to cell replacement therapy. Such tissue engineering approaches can be used to treat ischemic heart disease, fibrotic liver, fibrotic intestine, and traumatic spinal cord injury (SCI). For example, to treat spinal cord injury, the devices and assemblies described herein can facilitate the removal of scarred spinal cord tissue prior to the injection of an anti-inflammatory hydrogel loaded with lentiviruses to genetically engineer spinal cord neuronal regeneration, acting as a barrier to neuronal reconnection.

[0098] Figure 17 Examples of computing systems 1700 according to some examples of this disclosure are illustrated. System 1700 can be a client or a server. Figure 17As shown, system 1700 can be any suitable type of processor-based system, such as a personal computer, workstation, server, handheld computing device (portable electronic device) such as a telephone or tablet, or a dedicated device. System 1700 may include, for example, one or more of an input device 1720, an output device 1730, one or more processors 1710, a storage device 1740, and a communication device 1760. Input device 1720 and output device 1730 can generally correspond to those devices described above and can be connected to or integrated with a computer.

[0099] Input device 1720 may be any suitable device that provides input, such as a push-button switch, a touch screen, a keyboard or keypad, a mouse, a gesture recognition component of a virtual / augmented reality system, or a voice recognition device. Output device 1730 may be or include any suitable device that provides output, such as a display, a touch screen, a haptic device, a virtual / augmented reality display, or a speaker.

[0100] Storage device 1740 can be any suitable means of providing storage, such as electrical, magnetic, or optical memory including RAM, cache, hard disk drive, removable storage disk, or other non-transitory computer-readable media. Communication device 1760 can include any suitable means of transmitting and receiving signals over a network, such as a network interface chip or device. Components of computing system 1700 can be connected in any suitable manner, such as via a physical bus or wirelessly.

[0101] Processor 1710 may be any suitable processor or combination of processors, including any or any combination of a central processing unit (CPU), a graphics processing unit (GPU), a field-programmable gate array (FPGA), a programmable system-on-a-chip (PSOC), and an application-specific integrated circuit (ASIC). Software 1750, which may be stored in storage device 1740 and executed by one or more processors 1710, may include, for example, programming that embodies the functionality or features of this disclosure (e.g., as embodied in the apparatus described above).

[0102] Software 1750 may also be stored and / or transmitted in any non-transitory computer-readable storage medium for use by or in conjunction with an instruction execution system, device, or apparatus (such as those described above), which may retrieve and execute instructions associated with the software. In the context of this disclosure, a computer-readable storage medium may be any medium, such as storage device 1740, which may contain or store programs for use by or in conjunction with an instruction execution system, device, or apparatus.

[0103] Software 1750 can also be propagated within any transmission medium for use by or in conjunction with instruction execution systems, devices, or apparatuses (such as those described above), which can retrieve and execute instructions associated with the software. In the context of this disclosure, the transmission medium can be any medium capable of communicating, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, device, or apparatus. Transmission computer-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, or infrared wired or wireless propagation media.

[0104] System 1700 can be connected to a network, which can be any suitable type of interconnected communication system. The network can implement any suitable communication protocol and can be protected by any suitable security protocol. The network can include network links of any suitable arrangement that can implement the transmission and reception of network signals, such as wireless network connections, T1 or T3 lines, cable networks, DSL, or telephone lines.

[0105] System 1700 can implement any operating system suitable for operation on a network. Software 1750 can be written in any suitable programming language, such as C, C++, Java, or Python. In various implementations, application software embodying the functionality of this disclosure can be deployed in different configurations, such as client / server deployments, or deployed via a web browser as, for example, web-based applications or web services.

[0106] The elements and features of the exemplary electrode assemblies and conduits discussed above can be rearranged, recombined, and modified without departing from the invention. Furthermore, numerical indicators such as “first,” “second,” “third,” “fourth,” etc., are merely descriptive and do not indicate the relative order, position, or identity of the elements or features described by the indicators. For example, a “first” shock wave may be immediately followed by a “third” shock wave, and then a “second” shock wave. As another example, a “third” transmitter can be used to generate a “first” shock wave, and vice versa. Therefore, the numerical indicators of the various elements and features are not intended to limit this disclosure and can be modified and interchanged without departing from the invention.

[0107] As provided herein, it should be understood that any disclosure describing a range of values ​​for dimensions or measurements such as thickness, length, weight, time, frequency, temperature, voltage, current, angle, etc. includes any numerical increments or gradients relative to the range stated for a given dimension or measurement.

[0108] It should be noted that elements and features of the exemplary catheters illustrated throughout this specification and drawings can be rearranged, recombined, and modified without departing from the invention. For example, while this specification and drawings describe and illustrate catheters with several exemplary balloon designs, this disclosure is intended to include catheters with various balloon configurations. The number, placement, and spacing of the electrode pairs of the shock wave generator can be modified without departing from the invention. Furthermore, the number, placement, and spacing of the balloons in the catheter can be modified without departing from the invention.

[0109] It should be understood that the foregoing is merely an explanation of the principles of the invention, and various modifications, alterations, and combinations can be made by those skilled in the art without departing from the scope and spirit of the invention. Any variation of the various catheters disclosed herein may include the features described by any other catheter or combination of catheters herein. Furthermore, any method may be used with any of the disclosed catheters. Therefore, the invention is not intended to be limited except for the appended claims.

Claims

1. A method for generating one or more shock waves in a shock wave duct system, the method comprising: A first voltage is applied to one or more electrodes of the shock waveguide system to generate one or more bubbles in the fluid surrounding the one or more electrodes; as well as At least one packet of one or more second voltages is applied to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein: Each of the at least one packet includes multiple sub-pulses, and At least one of the plurality of sub-pulses has a duration of 1µs or less, or the frequency of the plurality of sub-pulses is between 100Hz and 10kHz. The one or more second voltages therein are different from the first voltage.

2. The method of claim 1, wherein the properties of the plurality of sub-pulses are based on the properties of the calcifications and / or tissues treated by the shockwave catheter system, wherein the properties of the calcifications and / or tissues include hardness, thickness, acoustic properties, or combinations thereof.

3. The method of claim 2, wherein the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within the at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the frequency of the plurality of sub-pulses, the amplitude of the electrical pulse, the acoustic output, or a combination thereof.

4. The method according to claim 1, wherein the number of the plurality of sub-pulses is greater than or equal to 10.

5. The method of claim 1, wherein the at least one packet has a duration of 20 µs or longer, a duty cycle of 50%, or both.

6. The method of claim 1, wherein the plurality of packets have frequencies between 1 Hz and 4 Hz, wherein the plurality of packets includes the at least one packet.

7. The method of claim 1, wherein the frequency of the plurality of sub-pulses is 100 times the frequency of the plurality of packets, wherein the plurality of packets includes the at least one packet.

8. The method according to claim 1, further comprising: One or more third voltages are applied during one or more inactive sub-pulse periods between the plurality of sub-pulses.

9. The method of claim 8, wherein the power level of the one or more inactive sub-pulse periods is 50% or less of the power level of the plurality of sub-pulses.

10. The method of claim 1, wherein the peak power of the at least one sub-pulse is 250 kW or higher.

11. A shock wave duct system, comprising: One or more electrodes; Fluid surrounding the one or more electrodes; A first voltage source, configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; and A second voltage source, configured to apply at least one packet of one or more second voltages to the one or more electrodes to generate one or more electric arcs at the one or more electrodes, wherein the at least one packet comprises a plurality of sub-pulses. At least one of the plurality of sub-pulses has a duration of 1µs or less, or the frequency of the plurality of sub-pulses is between 100Hz and 10kHz.

12. The shock waveguide system according to claim 11, further comprising: A controller configured to control the properties of the plurality of sub-pulses based on the properties of the calcifications and / or tissues treated by the shockwave catheter system, wherein the properties of the calcifications and / or tissues include hardness, thickness, acoustic properties, or combinations thereof.

13. The shock waveguide system of claim 12, wherein the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within the at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the electrical pulse amplitude, the acoustic output, or a combination thereof.

14. The shock waveguide system of claim 11, wherein the number of the plurality of sub-pulses is greater than or equal to 10.

15. The shock waveguide system of claim 11, wherein the at least one package has a duration of 20 µs or longer, a duty cycle of 50%, or both.

16. The shock waveguide system of claim 11, wherein the plurality of packages have frequencies between 1 Hz and 4 Hz, wherein the plurality of packages includes the at least one package.

17. The shock waveguide system of claim 11, wherein the first voltage source is a low-power voltage source and the second voltage source is a high-power voltage source.

18. The shock waveguide system of claim 11, wherein the one or more electrodes comprise electrode pairs separated by an electrode gap, and the one or more second voltages are applied across the electrode gap.

19. A method for operating a shock waveguide system, the method comprising: A first voltage is applied to one or more electrodes of the shock waveguide system to generate one or more bubbles in the fluid surrounding the one or more electrodes; The energy storage capacitor is charged using a second voltage source; The energy storage capacitor is used to charge the sub-pulse capacitor; as well as For multiple sub-pulses included in the package, energy stored in the sub-pulse capacitor is delivered to the one or more electrodes to generate one or more electric arcs at the one or more electrodes.

20. A shock waveguide system, comprising: One or more electrodes; Fluid surrounding the one or more electrodes; A first voltage source, configured to apply a first voltage to the one or more electrodes to generate one or more bubbles in the fluid; A second voltage source, configured to apply a second voltage; An energy storage capacitor, which is coupled to the second voltage source and configured to store charge from the second voltage source; and A sub-pulse capacitor coupled to the energy storage capacitor, wherein the sub-pulse capacitor is configured to store charge from the energy storage capacitor and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes.

21. A method for operating a shock waveguide system, the method comprising: A first voltage is applied to one or more electrodes of the shock waveguide system to generate one or more bubbles in the fluid surrounding the one or more electrodes; The capacitor is charged using a second voltage source; as well as For multiple sub-pulses included in the package, energy stored in the capacitor is delivered to the one or more electrodes to generate one or more electric arcs at the one or more electrodes. At least one of the plurality of sub-pulses has a duration of 1µs or less, or the frequency of the plurality of sub-pulses is between 100Hz and 10kHz.

22. A circuit comprising: A first voltage source is configured to apply a first voltage to one or more electrodes of a shock waveguide system to generate one or more bubbles in fluid surrounding the one or more electrodes. A second voltage source, configured to apply a second voltage comprising a plurality of sub-pulses; and A capacitor coupled to a second voltage source, wherein the capacitor is configured to store charge from the second voltage source and transfer the stored energy to the one or more electrodes to generate one or more electric arcs at the one or more electrodes. At least one of the plurality of sub-pulses has a duration of 1µs or less, or the frequency of the plurality of sub-pulses is between 100Hz and 10kHz.

23. A method for treating lesions in a body cavity, the method comprising: The shockwave catheter is advanced through the body cavity to the lesion; as well as A voltage pulse packet is applied, the packet comprising multiple sub-pulses delivered at a frequency of at least 10 Hz. Each of the plurality of sub-pulses generates a shock wave.

24. The method of claim 23, wherein the properties of the plurality of sub-pulses are based on the properties of the calcifications and / or tissues treated by the shockwave catheter, wherein the properties of the calcifications and / or tissues include hardness, thickness, acoustic properties, or combinations thereof.

25. The method of claim 24, wherein the properties of the plurality of sub-pulses include the number of the plurality of sub-pulses within at least one packet, the duration of the at least one sub-pulse, the peak power of the at least one sub-pulse, the frequency of the plurality of sub-pulses, the amplitude of the electrical pulse, the acoustic output, or a combination thereof.

26. The method of claim 23, wherein the number of the plurality of sub-pulses is greater than or equal to 10.

27. The method of claim 23, wherein the package has a duration of 20 µs or longer, a duty cycle of 50%, or both.

28. The method of claim 23, wherein the plurality of packets have frequencies between 1 Hz and 4 Hz, wherein the plurality of packets includes the packet.

29. The method of claim 23, wherein the frequency of the plurality of sub-pulses is 100 times the frequency of the plurality of packets, wherein the plurality of packets includes the packet.

30. The method of claim 23, further comprising: One or more second voltages are applied during one or more inactive sub-pulse periods between the plurality of sub-pulses.

31. The method of claim 30, wherein the power level of the one or more inactive sub-pulse periods is 50% or less of the power level of the plurality of sub-pulses.

32. The method of claim 23, wherein at least one of the plurality of sub-pulses has a peak power of 250 kW or higher.

33. A shock waveguide system, comprising: One or more electrodes; Fluid surrounding the one or more electrodes; and One or more voltage sources are configured to apply one or more voltages to the one or more electrodes according to an operating mode, wherein the operating mode includes burst mode operation and non-burst mode operation. The burst mode operation includes at least one packet of applying the one or more voltages to the one or more electrodes, each packet comprising a plurality of sub-pulses, and at least one of the plurality of sub-pulses having a duration of 1µs or less, or the plurality of sub-pulses having a frequency between 100Hz and 10kHz.

34. A method for operating a shock waveguide system, comprising: The shock waveguide system is operated in burst mode, wherein the burst mode operation includes at least one packet of applying one or more voltages to one or more electrodes of the shock waveguide system, wherein: Each of the at least one packet includes multiple sub-pulses, and At least one of the plurality of sub-pulses has a duration of 1µs or less, or the frequencies of the plurality of sub-pulses are between 100Hz and 10kHz; and The shock wave duct system is operated in a non-emergency mode.

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