System for treating thrombus in a body lumen

Abstract

To provide a suitable system for treating thrombus in a body lumen.SOLUTION: The present disclosure relates generally to thrombectomy devices. An exemplary catheter comprises an emitter assembly comprising at least one emitter, wherein each emitter comprises an electrode pair, and wherein each emitter is configured to generate a plurality of cavitation bubbles when a voltage is applied to the pair of electrodes, an infusion lumen formed by at least a portion of an outer wall of the catheter, wherein the infusion lumen is configured to receive a conductive fluid, wherein the emitter assembly is housed within the infusion lumen, and wherein a distal segment of the infusion lumen includes a plurality of holes on a portion of the outer wall of the catheter, wherein the plurality of holes are configured to release the conductive fluid and the plurality of cavitation bubbles out of the catheter to treat thrombus at a treatment site, and an aspiration lumen comprising an aspiration port at its distal segment.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 904,974, filed September 24, 2019, and entitled "SYSTEM FOR TREATING THROMBUS IN BODY LUMENS," the contents of which are incorporated herein by reference in their entirety. FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to thrombus removal devices, and more particularly to thrombus removal devices designed to generate cavitation bubbles for reducing or removing thrombi from a patient's vasculature. [Background technology]

[0003] Thrombectomy devices are designed to reduce the clot burden and partially or completely remove clots (i.e., thrombi) from a patient's vasculature. Currently, the mechanism for removing clots in most thrombus removal devices is mechanical, or it involves a combination of plasminogen activator ("tPA") treatment and mechanical processes. Some of these devices use ultrasound to diffuse tissue plasminogen activator (tPA). They do this by increasing the permeability of the thrombus structure, which exposes more sites to which the thrombolytic agent can bind. All of these devices are flawed because they provide undesirably slow rates of clot removal (which typically require an overnight stay in the hospital). Furthermore, these devices tend to be expensive, bulky, and difficult to operate. Still further, these devices can result in high blood loss in the patient.

[0004] Therefore, there is a need for a device that treats blood clots without the use of drugs (eg, tPA) and provides a cost-effective and time-efficient solution for treating thrombi. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention relates to a thrombus removal device designed to generate cavitation bubbles for reducing or removing thrombi from a patient's vasculature. Because embodiments of the present invention do not require the use of drugs (e.g., tPA) and can work quickly (e.g., less than two hours), the present invention provides a cost-effective and efficient solution for treating thrombi. [Means for solving the problem]

[0006] In one embodiment, the present invention provides a device for generating cavitation bubbles. An exemplary catheter includes an emitter assembly including at least one emitter, each emitter including a pair of electrodes, each configured to generate a plurality of cavitation bubbles when a voltage is applied to the pair of electrodes; an infusion lumen formed by at least a portion of an outer wall of the catheter, the infusion lumen configured to receive a conductive fluid, the emitter assembly housed within the infusion lumen, a distal segment of the infusion lumen including a plurality of holes on the portion of the outer wall of the catheter, the plurality of holes configured to release the conductive fluid and a plurality of cavitation bubbles out of the catheter to treat a thrombus at a treatment site; and an aspiration lumen formed within the catheter, the aspiration lumen including a plurality of aspiration ports in its distal segment.

[0007] In some embodiments, the emitter assembly includes an elongated conductive tube and an insulated wire having a helical coiled portion at an end of the insulated wire, the coiled portion including an exposed tip, the coiled portion positioned within the elongated conductive tube, and configured such that when a voltage is applied across the insulated wire and the elongated conductive tube, current flows from the exposed distal tip of the insulated wire to the elongated conductive tube and generates a plurality of cavitation bubbles.

[0008] In some embodiments, the elongate conductive tube comprises a slot and is configured to allow electrical current to flow from the exposed distal tip of the insulated wire to the edge of the slot.

[0009] In some embodiments, the electrical current is configured to flow from the exposed distal tip of the insulated wire to the inner wall of the elongate conductive tube.

[0010] In some embodiments, the emitter assembly comprises a first wire and a second wire, at least a portion of the insulation is removed from a portion of the first wire and at least a portion of the insulation is removed from a portion of the second wire, the portion of the first wire is interleaved with the portion of the second wire, and is configured such that when a voltage is applied across the first wire and the second wire, current flows from the first wire to the second wire and generates a plurality of cavitation bubbles.

[0011] In some embodiments, the emitter assembly includes a conductive sheath and an insulated wire having an exposed tip, wherein an electric current is configured to flow from the exposed distal tip of the insulated wire to the conductive sheath to generate a plurality of cavitation bubbles.

[0012] In some embodiments, the plurality of holes are arranged in three rows spaced 120 degrees apart on the outer wall of the catheter.

[0013] In some embodiments, the infusion lumen is Y-shaped.

[0014] In some embodiments, a pump is configured to deliver a continuous flow of conductive fluid through the infusion lumen to the emitter assembly.

[0015] In some embodiments, a continuous flow of conductive fluid washes debris into the aspiration lumen through multiple aspiration ports.

[0016] In some embodiments, a pump is configured to apply a suction force at the proximal end of the aspiration lumen to aspirate debris into the aspiration lumen through the plurality of aspiration ports.

[0017] In some embodiments, the suction ports of the plurality of suction ports are larger than the holes of the plurality of holes.

[0018] In some embodiments, the catheter further comprises a guidewire lumen for accommodating a guidewire.

[0019] In some embodiments, the catheter further comprises a distal cap configured to seal the distal end of the catheter, the distal cap comprising a hole for accommodating a guidewire.

[0020] In some embodiments, the catheter further comprises an electrical wire lumen for accommodating one or more wires of the emitter assembly.

[0021] In some embodiments, the voltage is between 500V and 1,200V.

[0022] In some embodiments, the repetition rate of the applied voltage is adjustable from 25 Hz to 200 Hz.

[0023] In some embodiments, the electrode pair comprises a spark gap between the electrodes of the pair, the spark gap being less than 0.005 inches. The present specification also provides, for example, the following items: (Item 1) A catheter, the catheter comprising: An emitter assembly comprising at least one emitter, Each emitter comprises an electrode pair; each emitter configured to generate a plurality of cavitation bubbles when a voltage pulse is applied to the pair of electrodes; an emitter assembly; an infusion lumen formed by at least a portion of the outer wall of the catheter, the infusion lumen configured to receive a conductive fluid; the emitter assembly is housed within the infusion lumen; the distal segment of the infusion lumen includes a plurality of holes on a portion of the outer wall of the catheter; the plurality of holes are configured to release the conductive fluid and the plurality of cavitation bubbles out of the catheter to treat a thrombus at a treatment site. an infusion lumen; a suction lumen formed within the catheter; Equipped with The catheter, wherein the aspiration lumen includes a plurality of aspiration ports in a distal segment thereof. (Item 2) The emitter assembly includes: an elongated conductive tube; Insulated wire and Equipped with the insulated wire having a helically coiled portion at an end thereof; the coiled portion includes an exposed tip; the coiled portion is positioned within the elongated conductive tube; Item 1, a catheter as described in item 1, configured such that when a pulsed voltage is applied across the insulated wire and the elongated conductive tube, current flows from the exposed distal tip of the insulated wire to the elongated conductive tube, generating the plurality of cavitation bubbles. (Item 3) 3. The catheter of claim 2, wherein the elongated conductive tube includes a slot, and the current is configured to flow from the exposed distal tip of the insulated wire to an edge of the slot. (Item 4) 3. The catheter of claim 2, wherein the electrical current is configured to flow from the exposed distal tip of the insulated wire to an inner wall of the elongated conductive tube. (Item 5) the emitter assembly includes a first wire and a second wire; at least a portion of insulation is removed from a portion of the first wire to define one electrode of the pair of electrodes; at least a portion of insulation is removed from a portion of the second wire to define a second electrode of the electrode pair; the portions of the first wire are interleaved with the portions of the second wire; Item 1, a catheter as described in item 1, configured such that when a pulsed voltage is applied across the first wire and the second wire, current flows from the first wire to the second wire and generates the plurality of cavitation bubbles. (Item 6) The emitter assembly includes: a conductive sheath; an insulated wire having an exposed tip; Equipped with Item 1, wherein the catheter is configured such that an electric current flows from the exposed distal tip of the insulated wire to the conductive sheath to generate the plurality of cavitation bubbles. (Item 7) Item 1. The catheter of item 1, wherein the plurality of holes are arranged in three rows spaced 120 degrees apart on the outer wall of the catheter. (Item 8) Item 10. The catheter of item 1, wherein the infusion lumen is Y-shaped. (Item 9) Item 14. The catheter of item 1, wherein a pump is configured to deliver a continuous flow of conductive fluid through the infusion lumen to the emitter assembly. (Item 10) 10. The catheter of claim 9, wherein the conductive fluid comprises saline. (Item 11) 10. The catheter of claim 9, wherein the continuous flow of the conductive fluid flushes debris into the aspiration lumen through the plurality of aspiration ports. (Item 12) 2. The catheter of claim 1, wherein a pump is configured to apply a suction force at a proximal end of the suction lumen to aspirate debris into the suction lumen through the plurality of suction ports. (Item 13) Item 1, wherein the suction ports of the plurality of suction ports are larger than the holes of the plurality of holes. (Item 14) Item 14. The catheter of item 1, further comprising a guidewire lumen for accommodating a guidewire. (Item 15) Item 15. The catheter of item 14, further comprising a distal cap configured to seal a distal end of the catheter, the distal cap comprising a hole for accommodating the guidewire. (Item 16) Item 14. The catheter of item 1, further comprising an electrical wire lumen for accommodating one or more wires of the emitter assembly. (Item 17) Item 1. The catheter according to item 1, wherein the voltage of the applied voltage pulse is 500V to 1,200V. (Item 18) Item 1. The catheter according to item 1, wherein the repetition rate of the applied voltage pulses is adjustable between 25 Hz and 200 Hz. (Item 19) Item 1. The catheter of item 1, wherein the electrode pair comprises a spark gap between the electrodes of the pair, the spark gap being less than 0.005 inches. [Brief explanation of the drawings]

[0024] [Figure 1] 1A and 1B depict an exemplary emitter assembly, according to some embodiments.

[0025] [Figure 2A] FIG. 2A depicts a cross-sectional view of an exemplary catheter housing an emitter assembly, according to some embodiments.

[0026] [Figure 2B] FIG. 2B depicts another exemplary catheter housing an emitter assembly, according to some embodiments.

[0027] [Figure 3] FIG. 3 depicts another exemplary emitter assembly, according to some embodiments.

[0028] [Figure 4] FIG. 4 depicts another exemplary emitter assembly, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0029] The following description is presented to enable those skilled in the art to make and use various embodiments. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications of the examples described herein will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Accordingly, the various embodiments are not intended to be limited to the examples described and shown herein, but are to be accorded scope consistent with the claims.

[0030] Described herein are exemplary systems and methods for reducing or removing thrombi from a patient's vasculature by generating cavitation bubbles via a voltage source. According to some embodiments, the treatment system includes a catheter and one or more emitters housed within the catheter. The catheter is advanced (e.g., via a guidewire) within a body lumen (e.g., a blood vessel) to a treatment site. Each emitter includes an electrode that, when connected to a relatively low voltage and high PRF (pulse repetition rate) generator, forms a plasma arc, which in turn leads to the generation and collapse of a large number of cavitation bubbles. In some embodiments, the catheter includes one or more rows of cavitation holes for releasing the cavitation bubbles in an omnidirectional manner. The cavitation bubbles create mechanical vibrations, turbulence, jets, and / or forceful collapse, weakening and disrupting the fibrin network, thus reducing or removing the thrombus.

[0031] The present invention differs from electrohydraulic lithotripsy. The voltage at each emitter (i.e., across the spark gap) is lower than in intravascular lithotripsy ("IVL") treatment. In some embodiments, the generator voltage is adjusted between 500 V and 1,200 V, and the repetition rate is adjusted between 25 Hz and 200 Hz. To maintain the breakdown voltage, the spark gap at the emitter (e.g., the spark gap formed between the two electrodes of an electrode pair) is small enough to allow sparking. In some embodiments, the gap is less than 0.005 inches. Furthermore, the delivered energy is lower than IVL; therefore, the acoustic power is typically not sufficient to generate any pressure amplitude from the shock wave.

[0032] 1A depicts an exemplary emitter assembly 100, according to some embodiments. The emitter assembly 100 includes two conductive elongated tubes 110 and 112. Each elongated tube has a plurality of longitudinal slots to facilitate the generation of cavitation bubbles, as discussed below. Additionally, the emitter assembly 100 includes three wires 102, 104, and 106. In some examples, the elongated tubes may be stainless steel hypotubes, and the wires may be polyimide-insulated copper wires.

[0033] The first insulated wire 102 comprises a helical coiled portion at its distal end, which is disposed within the first elongated tube 110. In some embodiments, the helical coiled portion is bonded to the inner wall of the elongated tube 110 using an adhesive (e.g., epoxy or cyanoacrylate adhesive). Similarly, the second insulated wire 104 comprises a helical coiled portion at its distal end, which is disposed within the second elongated tube 112. The third insulated wire 106 has a distal end connected (e.g., welded) to the second elongated tube 112. Furthermore, the proximal end of the second insulated wire 104 is connected (e.g., welded) to the first elongated tube 110.

[0034] When the emitter assembly 100 is connected to a voltage source, current traverses through the two elongated tubes and three wires, generating cavitation bubbles in two locations. Referring to FIG. 1A , the proximal end of the first wire 102 is connected to the positive port of a voltage generator (not depicted), and the proximal end of the third wire 106 is connected to the negative port of the voltage generator. The generator delivers energy in a continuous pulse mode or in a series of short bursts. Thus, current i traverses the emitter assembly, as indicated by the arrows. As shown, current i traverses from the proximal end of the first insulated wire 102 toward its distal coiled portion. At the distal end of the first insulated wire 102, the conductive core of the wire is exposed, thus allowing current to traverse from the distal end of the wire 102 to the first elongated tube 110. The exposed distal end of the first wire 102 and the first elongated tube 110 form a first electrode pair for generating cavitation bubbles.

[0035] The current i traverses from the first elongated tube 110 to the proximal end of the second insulated wire 104 and then further to the distal coiled portion of the second insulated wire 104. At the distal end of the second insulated wire 104, the conductive core of the wire is exposed, thus allowing the current to traverse from the distal end of the wire 104 to the second elongated tube 112. The exposed distal end of the second wire 104 and the second elongated tube 112 form a second electrode pair for generating cavitation bubbles. The current i then returns to the voltage generator via the third insulated wire 106.

[0036] When current i traverses from the distal coiled portion of the wire to the elongated tube enclosing the coiled portion, multiple plasma arcs form between the exposed distal end of the wire and the inner surface of the elongated tube. The plasma arcs lead to cavitation bubbles in a controlled manner (one at a time, at a specific rate), which in turn lead to mechanical vibrations (e.g., via bubble expansion and collapse) and other bubble dynamics-related effects in the conductive fluid, such as collapse, turbulence, and jetting. The mechanical vibrations play a role in reducing or removing thrombi. Cavitation is known to weaken the fibrin network bridges that form the basic structure of thrombi. The combination of mechanical vibrations and bubble cavitation can be effective in thrombolysis. Compared to the generators used in the prior art shock wave generating systems mentioned above, the generator for this system is configured to generate lower voltage pulses at a higher pulse repetition rate to minimize the intensity of any shock waves and optimize and maximize bubble growth and collapse. For example, in prior art systems, each pulse may be approximately 3,000 volts with a 1 Hz repetition rate. In an embodiment of the system, the voltage of the voltage pulses is adjusted between 500 V and 1,200 V, the repetition rate of the voltage pulses is adjusted between 25 Hz and 200 Hz, and the pulse duty cycle is adjusted between 10 and 50%. These parameters can be varied based on the clot condition.

[0037] FIG. 1B depicts an exemplary emitter assembly 100 from a different angle showing the distal coiled portions of the two wires, according to some embodiments. Because the plasma arc causes erosion of the electrodes during operation, the helically coiled wire portions of wires 102 and 104 may erode and shorten over time. Depending on where the distal ends of the wires are located, the spark gap (i.e., where the plasma arc forms) may be between the distal ends of the wires and the inner wall of the elongated tube (as shown in Detail A) or between the distal ends of the wires and the edge of the slot in the elongated tube (as shown in Detail B). Note that as the coiled wire portions erode, the location of cavitation bubble generation will change. In the illustrated embodiment, the location of cavitation bubble generation will rotate circumferentially around the periphery of conductive tubes 110 and 112.

[0038] Additional details regarding electrode pairs formed by coiled wires and elongated tubes, along with possible variations, are provided in assignee's prior application U.S. Publication No. 2019 / 0388110, entitled "SYSTEM FOR TREATING OCCLUSIONS IN BODY LUMENS," which is incorporated by reference. While Figures 1A-B depict an emitter assembly comprising two emitters connected in series driven by one voltage source, it should be understood that the emitter assembly may comprise any number of emitters arranged in any configuration driven by one or more voltage sources.

[0039] Figure 2A depicts a cross-sectional view of an exemplary catheter 200 comprising several lumens, according to some embodiments. Catheter 200 comprises a Y-shaped infusion lumen 210 and three oval lumens: guidewire lumen 204, electrical wire lumen 206, and suction lumen 208. As shown in Figure 2A, oval lumens 204, 206, and 208 are spaced approximately 120 degrees apart along the outer wall of the catheter and are formed at least partially from the outer wall of the catheter. The inner edges of guidewire lumen 204, electrical wire lumen 206, and suction lumen 208 define the outer edge of central Y-shaped infusion lumen 206.

[0040] The Y-shaped infusion lumen 210 houses an emitter assembly 202, which may be any of the emitter assemblies described herein (e.g., 100, 300, 400). As discussed above, the emitter assembly 202 comprises a number of elongated conductive tubes and wires forming a number of emitters (or electrode pairs). In some embodiments, the emitter assembly 202 is located in the distal segment of the catheter.

[0041] The Y-shaped infusion lumen 210 can further be used to deliver an ionic solution (e.g., a conductive solution such as saline or saline mixed with a contrast agent) from the pump to the emitter assembly 202. When the emitter assembly 202 is connected to a voltage source, cavitation bubbles can be generated through the conductive fluid at multiple locations along the catheter.

[0042] The Y-shaped infusion lumen further includes multiple rows of cavitation holes for releasing cavitation bubbles. In the depicted example, three rows of cavitation holes 212a, 212b, and 212c are spaced 120 degrees apart. As shown in FIG. 2A, the cavitation holes 212a, 212b, and 212c may include multiple side holes extending along a portion of the circumference of the distal end of the catheter. The cavitation holes are positioned to maximize cavitation bubble release, for example, directly above the first elongated tube, the second elongated tube, or another element of the emitter assembly. Thus, cavitation bubbles from the emitter assembly are carried radially through the rows of cavitation holes to the thrombus by the pumped flow of ionic solution.

[0043] The aspiration lumen 208 can be used to remove debris (e.g., metal, air bubbles) and thrombus fragments from the treatment site. As shown, the aspiration lumen 208 includes a series of aspiration ports 214. The aspiration ports 214 are generally larger than the cavitation holes 212. As more conductive fluid is injected, debris and thrombus fragments are washed toward the aspiration lumen and carried away from the treatment site. Additionally, or alternatively, a suction force can be provided at the proximal end of the aspiration lumen 208. Debris and thrombus fragments can be sucked into the aspiration ports 214 and carried away from the treatment site via the flow of conductive fluid. Rapid removal of debris helps refresh the cavitation.

[0044] The electrical wire lumen 206 can be used to accommodate one or more wires of the emitter assembly 202. For example, the wire (e.g., wire 106) connecting the distal portion of the emitter assembly to the negative port of the voltage generator can extend through the electrical wire lumen 206 for better insulation. The wire lumen 206 can also carry one or more additional wires, such as wire 102 connecting the proximal portion of the emitter assembly to the positive port of the voltage generator. The guidewire lumen 204 can be used to accommodate a guidewire and can be shaped to carry a guidewire having a diameter of about 0.014 inches to about 0.035 inches. The guidewire is used to advance the catheter 200 to the treatment site.

[0045] FIG. 2B depicts another exemplary catheter housing an emitter assembly, according to some embodiments. As shown, the catheter includes a cap 230 including a guidewire port for receiving a guidewire (e.g., a guidewire carried within the guidewire lumen of the catheter during advancement of the catheter). Additionally, the shape and location of the suction port and cavitation holes differ from those in the embodiment illustrated in FIG. 2A. For example, as shown in FIG. 2B, the suction port can be formed as a longitudinal slot sized to allow debris from cavitation to escape through the suction port. The cavitation port can include multiple approximately circular holes in the catheter housing (i.e., the outer wall of the catheter) to allow access to the Y-shaped infusion lumen.

[0046] The catheter of Figures 2A-B can be used in conjunction with a pump. In some embodiments, the pump delivers an ionic solution (i.e., a conductive solution such as saline or saline mixed with contrast) through the infusion lumen to the catheter tip (where cavitation occurs). The pump or an auxiliary pump also aspirates debris away from the thrombus region. The infusion flow can be synchronized with the emitter power delivery to ensure the proper ionic solution around the emitter. The aspiration and infusion flows can be synchronized to maintain pressure equilibrium at the treatment site. In some examples, the saline or saline / vascular contrast flow is regulated to avoid overheating issues and control treatment efficiency and rate.

[0047] In some embodiments, additional components are included within the treatment system, such as a proximal balloon to capture debris generated by the emitter, a visualization system and / or a steering system to properly navigate and place the catheter (e.g., side branch), etc. Additional details of the treatment system are provided in U.S. Publication No. 2019 / 0388110 (referenced above and incorporated herein by reference).

[0048] In some embodiments, the procedure can take approximately 30 minutes, during which time the emitter assembly 202 continuously generates cavitation bubbles. These operating parameters (e.g., the voltage, repetition rate, or pulse duty cycle of the voltage pulses) can be set based on clot characteristics (e.g., clot size, clot age, clot composition, clot consistency, arterial or venous location of the clot, clot platelet content, clot fibrin content, or some other attribute of the clot) and / or patient characteristics (e.g., the patient's age or pre-existing medical conditions). In some embodiments, post-procedure minimally invasive procedures (e.g., treatment of bleeding, thrombus re-formation) can be performed after the procedure.

[0049] FIG. 3 depicts another exemplary emitter assembly housed within a catheter 300, according to some embodiments. The emitter assembly includes four wires 302, 304, 306, and 308. Each of the four wires includes a portion that is helically wound around a shaft 320 (e.g., a guidewire shaft having a lumen for carrying a guidewire), and together, the four wires form three interleaved wire portions. The interleaved wire portions may include multiple (i.e., two or more) portions of wire configured in an interleaved manner. For example, an interleaved wire portion may include a portion of a wire coiled with a portion of another wire. In some variations, the wires and the interleaved wire portions are configured in series. For example, the first wire 302 may be electrically coupled to the positive terminal of a voltage source. The first interleaved wire portion may include a portion of the first wire 302 interleaved with a first portion of the second wire 304. The first wire 302 may have a voltage or potential that is more positive than the second wire 304. Similarly, the second interleaved wire portion 304 may comprise a second portion of the second wire 304 interleaved with a first portion of the third wire 306. The second wire 304 may have a voltage or potential that is more positive than that of the third wire 306. The third interleaved wire portion 306 may comprise the second portion of the third wire 306 and a portion of the fourth wire 308. The third wire 306 may have a voltage or potential that is more positive than that of the fourth wire 308. The fourth wire 308 may be electrically coupled to the negative terminal of a voltage source.

[0050] In the illustrated embodiment of FIG. 3 , each interleaved wire portion includes at least one pair of electrodes. The electrodes of each pair are defined by removing a small region of insulation from adjacent portions of the interleaved wire. When the wire is surrounded by a conductive fluid (i.e., when conductive fluid is flowed through the wire lumen), a high voltage is delivered to the wire, and an electrohydraulic discharge generates a plasma that generates cavitation bubbles in the arcing region across the electrodes. Additional details of the operation and possible variations of the emitter assembly can be found in the assignee's prior application, U.S. Publication No. 2018 / 0098779, entitled “AORTIC LEAFLET REPAIR USING SHOCK WAVE APPLICATORS,” which is incorporated by reference.

[0051] In the illustrated embodiment of Figure 3, the emitter assembly is housed within a catheter 300, such as any of the catheters described with respect to Figures 2A-B. As shown, the catheter includes an array of cavitation holes (e.g., longitudinal or lateral slots or circular holes) positioned above the emitter to emit cavitation bubbles in an omnidirectional manner.

[0052] FIG. 4 depicts another exemplary emitter assembly housed within a catheter 400, according to some embodiments. The emitter assembly includes four wires 402, 404, 406, and 408 and three conductive sheaths 410, 412, and 414. The conductive sheaths are wrapped around a portion of a shaft 420 (e.g., a guidewire shaft having a lumen for carrying a guidewire). An outer electrode is formed by the conductive sheath, and an inner electrode is formed by removing a portion of the insulated wire (e.g., cutting a hole in the insulation layer near the end of the wire) to expose the conductive portion of the insulated wire. The inner electrode is positioned a controlled distance from the side edge of the conductive sheath to enable reproducible arcing for a given current and voltage. In operation, a plasma arc can be formed across the inner electrode and the side edge of the conductive sheath.

[0053] 4, the emitter assembly is connected to a voltage source using a first wire 402 and a fourth wire 408, e.g., the first wire is connected to the positive port and the fourth wire is connected to ground at the negative port. Current traverses from the first wire 402 to the first conductive sheath 410, to the second wire 404, to the second conductive sheath 412, to the third wire 406, to the third conductive sheath 414, to the fourth wire 408, and to the negative port of the voltage source. Thus, the emitter assembly generates cavitation bubbles in six locations (i.e., at the two side edges of each conductive sheath where the sheaths form electrode pairs with the insulation-removed portions of the wires). Additional details of the operation and possible variables of the emitter assembly can be found in the assignee's prior application U.S. Publication No. 2019 / 0150960, entitled "LOW PROFILE ELECTRODES FOR A SHOCK WAVE CATHETER," which is incorporated by reference.

[0054] In the illustrated embodiment of Figure 4, the emitter assembly is housed within a catheter 400, such as any of the catheters described with respect to Figures 2A-B. As shown, the catheter includes an array of cavitation holes (e.g., longitudinal or lateral slots or circular holes) positioned above the emitter to emit cavitation bubbles in an omnidirectional manner.

[0055] It should be understood that the foregoing is merely illustrative of the principles of the present invention, and that various modifications, alterations, and combinations may be made by those skilled in the art without departing from the scope and spirit of the present invention. Any of the various cavitation device variations disclosed herein may include features described in combination with any other cavitation device or shock wave device herein. Furthermore, any of the methods may be used with any of the disclosed cavitation devices. Therefore, the present invention is not intended to be limited except as by the appended claims. With respect to all of the variations described above, the method steps need not be performed sequentially.

Claims

1. A catheter for use in a lumen of the vascular system, said catheter comprising: an emitter assembly configured to generate a plasma arc; an outermost wall defining an infusion lumen configured to receive a conductive fluid; a cavitation hole extending through the outermost wall and opening into the injection lumen, the cavitation hole being aligned with the emitter assembly; It is equipped with The emitter assembly is positioned within the conductive fluid when the conductive fluid is received within the infusion lumen such that the plasma arc generates a plurality of cavitation bubbles within the conductive fluid, and the cavitation holes are sized and shaped to direct the plurality of cavitation bubbles radially outward from the catheter toward a treatment region of the lumen of the vasculature.

2. A catheter as described in claim 1, wherein the catheter extends longitudinally between a proximal end and a distal end, and the cavitation holes include a row of cavitation holes positioned longitudinally within the outermost wall between the proximal end and the distal end.

3. A catheter as described in claim 2, wherein the cavitation holes include multiple rows of cavitation holes positioned vertically within the outermost wall between the proximal end and the distal end, each row being spaced apart around the outer periphery of the outermost wall.

4. A catheter as described in claim 3, further comprising a suction lumen separate from and extending parallel to the injection lumen, and a port defined within the outermost wall and opening into the suction lumen, the port being spaced from the plurality of rows of cavitation holes around the outer periphery of the outermost wall and positioned to receive debris and tissue fragments from the treatment area of ​​the lumen of the vascular system via the flow of the conductive fluid.

5. A catheter as described in claim 4, wherein each cavitation hole has an outer opening defined within the outermost wall, and the port has an outer opening within the outermost wall that is larger than each outer opening of the cavitation hole.

6. A catheter as described in claim 4, further comprising a guidewire lumen extending parallel to the injection lumen and the suction lumen and sized to carry a guidewire.

7. A catheter as described in claim 3, wherein the emitter assembly includes a plurality of emitter assemblies spaced longitudinally between the proximal and distal ends of the catheter, each emitter assembly aligned with a portion of each of the plurality of rows of cavitation holes.

8. A catheter as described in claim 1, further comprising a suction lumen separate from and extending parallel to the injection lumen, and a port defined within the outermost wall and opening into the suction lumen, the port positioned to receive debris and tissue fragments from the treatment area of ​​the lumen of the vascular system via the flow of the conductive fluid.

9. A catheter as described in claim 8, wherein the cavitation hole has an outer opening located at a first circumferential position on the outermost wall, and the port has an outer opening located at a second circumferential position on the outermost wall spaced apart from the outer opening of the cavitation hole.

10. A catheter as described in claim 9, wherein the outer opening of the port is larger than the outer opening of the cavitation hole.

11. The catheter of claim 8, further comprising a guidewire lumen extending parallel to the injection lumen and the aspiration lumen and sized to carry a guidewire.

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