Apparatus and method for generating a positive shock wave

Abstract

An impulsive wave device for treating a vascular occlusion is described. The impulsive wave device includes an outer covering and an inner member connected at a distal end of the device. First and second conductive wires extend along a length of the device within a volume between the outer covering and the inner member. A conductive launch band surrounds the ends of the first and second conductive wires to form a first spark gap between the end of the first conductive wire and the launch band and a second spark gap between the end of the second conductive wire and the launch band. First and second impulsive waves can be initiated from the first and second spark gaps when the volume is filled with a conductive fluid and a high voltage pulse is applied across the first and second conductive wires.

Description

[0001] This application is a divisional application. The international application number of its parent application is PCT / US2018 / 034855, the Chinese national application number is 201880040835.6, the application date is May 29, 2018, and the invention title is "Apparatus and method for generating a positive shock wave".

[0002] Cross-references to related applications

[0003] This application claims priority to provisional application serial number No. 62 / 521,994, filed on June 19, 2017, the entire disclosure of which is incorporated herein by reference. Technical Field

[0004] This disclosure relates generally to the generation of shock waves, and more specifically to the generation of shock waves within blood vessels or urinary structures. Background Technology

[0005] This invention relates to the treatment of calcified lesions or other obstructions in blood vessels, such as kidney stones in the ureter. A common approach to this problem is balloon angioplasty. In this procedure, a catheter carrying a balloon is advanced along a guidewire into the vascular system until the balloon is aligned with the obstruction. The balloon is then pressurized to reduce or rupture the obstruction. When inflated to high pressure, angioplasty balloons can have a specific maximum diameter to which they will expand. Typically, the opening in a blood vessel beneath a concentric lesion is much smaller. As pressure builds to open the channel for blood flow, the balloon is confined to the size of the opening in the calcified lesion (before it ruptures). As pressure builds, a large amount of energy is stored in the balloon until the calcified lesion ruptures or bursts. This energy is then released, causing the balloon to rapidly inflate to its maximum size, potentially compressing and damaging the vessel wall.

[0006] Recently, the assignee of this application has developed a system and method for breaking up calcium deposits, such as in arteries and veins. Such systems are described, for example, in U.S. Patent Nos. 8,956,371 and 8,888,788, both of which are incorporated herein by reference. The embodiments described therein include a catheter having a balloon, such as an angioplasty balloon, at its distal end, arranged to be inflated with fluid. A shock wave generator is disposed within the balloon, which may take the form, for example, a pair of electrodes connected via a connector to a high-voltage source at the proximal end of the catheter. When the balloon is placed near a calcified area in a vein or artery and a high-voltage pulse is applied to the electrodes, a shock wave is generated that propagates through the fluid and impacts the balloon wall and the calcified area. Repeated pulses break down the calcium without damaging the surrounding soft tissue. Similar techniques can be used to treat kidney stones in the ureter. The shock waves generated by such a system typically propagate from the electrodes in all directions.

[0007] Arteries are sometimes completely blocked by thrombi, plaques, fibrous plaques, and / or calcium deposits. When this is the case, doctors typically begin by inserting a soft, narrow guidewire down the artery through the occlusion. The guidewire can be as small as 0.014 inches in diameter and usually has a soft tip to help avoid penetrating the arterial wall at bends. An angioplasty balloon is then advanced down the artery along the guidewire to the desired occlusion location. Unfortunately, many times doctors face chronic occlusions where the guidewire cannot pass. This occurs when the occlusion is so tight and strong that a soft guidewire cannot penetrate it. In these cases, stiffer guidewires can be used, but they must be used very carefully because they can easily penetrate the arterial wall when dealing with chronic, complete occlusions.

[0008] A guidewire that uses radiofrequency energy to open occlusions has been proposed. Unfortunately, the heat generated by opening occlusions with radiofrequency energy is intense and can damage the arterial or vessel wall. Radiofrequency energy generates plasma that burns any material in its path. Therefore, such systems must be used with care and must be operated continuously without pause to avoid damaging the artery or vessel. Furthermore, this method requires a centering mechanism to keep the plasma aligned within the artery or vessel. Such alignment is difficult to achieve, especially at bends and curves in arteries or veins.

[0009] Recently, the assignee of this application has proposed placing an electrode at the end of a guidewire to generate a positive shock wave sufficient to open a complete occlusion, thereby allowing the guidewire and angioplasty balloon to be fed through it. Furthermore, this system avoids damage to the artery or vessel. This method is disclosed in U.S. Patent Application No. 2015 / 0320432, which is also incorporated herein by reference.

[0010] This invention relates to an alternative method for generating positive shock waves that can be integrated with an angioplasty balloon. This method can also be used in conjunction with other types of shock wave electrodes. Summary of the Invention

[0011] This document describes a shockwave device and method for treating plaque or occlusion in blood vessels. Blood vessels may include blood vessels in a patient's vascular system or ureters in a patient's urinary system. One example of a shockwave device includes an outer cover and an internal component forming a guidewire lumen. The outer cover and internal component are connected at a distal end of the device, and a volume between the outer cover and the internal component may be filled with a conductive fluid. A first and second conductor extend along the length of the device within the volume between the outer cover and the internal component, with their ends near the distal end of the device. The lengths of the first and second conductors are insulated, while the ends of the first and second conductors are uninsulated. A conductive emitter band surrounds the ends of the first and second conductors, forming a first spark gap between the end of the first conductor and the emitter band, and a second spark gap between the end of the second conductor and the emitter band. When the volume is filled with conductive fluid and a high-voltage pulse is applied to both ends of the first and second conductors, first and second shock waves are initiated from the first and second spark gaps.

[0012] In some examples, the device further includes an insulating sheath surrounding the inner member in a region near the ends of the first and second leads. In some variations, the outer cover includes an angioplasty balloon. In some examples, the delivery band is a cylindrical tube extending further distal to the device than the first and second leads. In some examples, the device further includes: a fluid pump connected to the proximal end of the device, configured to supply conductive fluid to the volume between the outer cover and the inner member; and a fluid return line having an inlet near the distal end of the device and configured to remove conductive fluid from the volume between the outer cover and the inner member. The fluid pump and the fluid return line may be configured to circulate the conductive fluid under pressure within the volume between the outer cover and the inner member. In some examples, the device further includes a pressure-reducing valve at the outlet of the fluid return line.

[0013] In some examples, the device further includes third and fourth conductors extending along the length of the device within a volume between the outer cover and the inner components, terminating near the distal end of the device. The lengths of the third and fourth conductors may be insulated, and the ends of the third and fourth conductors may be uninsulated. A conductive emitting strip may surround the ends of the third and fourth conductors, forming a third spark gap between the end of the third conductor and the emitting strip, and a fourth spark gap between the end of the fourth conductor and the emitting strip. When the volume is filled with a conductive fluid and a second high-voltage pulse is applied to both ends of the third and fourth conductors, third and fourth shock waves can be induced from the third and fourth spark gaps. In some examples, the conductive fluid comprises saline solution or a combination of saline solution and a contrast agent. In some examples, the device further includes one or more secondary emitting strips disposed at an intermediate position in the device and configured to induce at least a third shock wave from the intermediate position.

[0014] An example of the method includes: introducing a shock wave device into a blood vessel; advancing the shock wave device within the vessel such that the distal end of the shock wave device faces a first treatment area; and applying high-voltage pulses at both ends of first and second leads to initiate first and second shock waves from first and second spark gaps formed between the first and second leads and the emitting strip. The positioning of the first and second leads and the emitting strip causes the first and second shock waves to propagate in a generally positive direction.

[0015] In some examples, the method further includes, after the application step, further advancing the shock wave device within the blood vessel such that the angioplasty balloon is aligned with the first or second treatment area, and inflating the angioplasty balloon. In some examples, the method also includes, after the application step, further advancing the shock wave device within the blood vessel such that one or more secondary radiating bands at a central position of the device are aligned with the first or second treatment area, and emitting a third shock wave from the secondary radiating bands. In some examples, the blood vessel is a vessel in the patient's vascular system or a ureter in the patient's urinary system. In some examples, the first treatment area includes a chronic total occlusion (CTO), surrounding calcium deposits, or kidney stones. Attached Figure Description

[0016] Figure 1 A cross-sectional perspective view of an exemplary shock wave device for generating a positive shock wave according to some embodiments is depicted.

[0017] Figure 2 A side cross-sectional view of an exemplary shock wave device for generating a positive shock wave according to some embodiments is depicted.

[0018] Figure 3 A front cross-sectional view of an exemplary shock wave device for generating a positive shock wave according to some embodiments is depicted.

[0019] Figure 4 An extended side sectional view is depicted of an exemplary shock wave device for generating a positive shock wave according to some embodiments.

[0020] Figure 5 A side view depicting the extended length of an exemplary shock wave device according to some embodiments is shown.

[0021] Figure 6 This is a flowchart of an exemplary method for generating a positive shock wave. Detailed Implementation

[0022] This document describes apparatus, systems, and methods for generating shock waves that propagate generally in a positive direction to treat vascular diseases such as chronic total occlusion (CTO) or peripheral calcium, or to treat urinary system diseases such as stones or kidney stones in the ureter. According to this disclosure, a shock wave apparatus includes an outer cover and an inner member forming a guidewire lumen. The outer cover and the inner member are connected at a distal end of the apparatus. A first conductor and a second conductor extend along the length of the apparatus within a volume between the outer cover and the inner member and terminate near the distal end of the apparatus. A conductive emitting strip surrounds the ends of the first and second conductors to form a first spark gap between the end of the first conductor and the emitting strip, and a second spark gap between the end of the second conductor and the emitting strip.

[0023] When the volume is filled with a conductive fluid (e.g., saline and / or imaging contrast agent) and a high-voltage pulse is applied to both ends of the first and second conductors, first and second shock waves can be induced from the first and second spark gaps. The voltage can range from 100 to 10,000 volts for various pulse durations. This high voltage may generate bubbles at the end faces of the conductors, causing a plasma arc of current to pass through the bubbles to the emission strip, producing rapidly expanding and collapsing bubbles, which in turn generate a mechanical shock wave at the distal end of the device. The positioning of the emission strip relative to the ends of the conductors causes the shock wave to propagate toward the distal end of the device in a generally positive direction. The shock wave can be mechanically conducted in a generally positive direction through the conductive fluid and the outer covering to apply mechanical force or pressure, thereby impacting the occluder or calcium facing the distal end of the device. The size of the bubbles, the rate of expansion and collapse (and therefore the magnitude, duration, and distribution of the mechanical force) can vary based on the size and duration of the voltage pulse and the distance between the ends of the conductors and the emission strip. The emitter belt can be made of materials capable of withstanding the high voltage levels and intense mechanical forces generated during use (e.g., approximately 1000-2000 psi or 68-136 ATM within a few microseconds). For example, the emitter belt can be made of stainless steel, tungsten, nickel, iron, steel, etc.

[0024] Figure 1 A cross-sectional perspective view of an exemplary shock wave device 100 for generating a positive shock wave according to some embodiments is depicted. The device 100 includes an outer cover 102 (e.g., a flexible outer tube) and an inner member 104 forming a lumen for a guide wire 114. The outer cover 102 and the inner member 104 are connected at a distal end of the device 100, wherein the guide wire 114 can exit the device 100. The internal volume of the device 100 between the outer cover 102 and the inner member 104 may be filled with a conductive fluid (e.g., saline and / or imaging contrast agent). Two insulated wires 106 (e.g., insulated copper wires) extend along the length of the device 100 within the internal volume. Figure 1 Only one conductor, 106, is visible in the middle, but as... Figure 2-3As shown, the second conductor 106 extends along the opposite side of the internal member 104. Both conductors 106 terminate near the distal end of the device 100, where the guidewires exit the cavity formed by the internal member 104. The ends of the two conductors 106 include uninsulated portions (not shown). For example, the flat, circular surfaces at the ends of the two conductors may be uninsulated. A transmitting strip 108 is located within the internal volume surrounding the ends of the two conductors 106. The transmitting strip 108 may be a conductive cylinder with a diameter greater than the combined diameter of the internal member 104 and the two conductors 106, such that the transmitting strip surrounds the ends of the two conductors 106 without contacting them. Figure 2 As shown. An insulating sheath 110 (e.g., a polyimide insulator) may be located around the inner member 104 to separate the two conductors 106 from the inner member 104 and further insulate the two conductors 106 from each other. Thus, the preferred conductive path between the two conductors 106 is through the emitting strip 108. When a high-voltage pulse is applied across the ends of the two conductors 106, current will arc from the uninsulated end of one conductor to the emitting strip 108, and then arc again from the emitting strip 108 to the uninsulated end of the other conductor. As a result, a shock wave is generated at the distal end of the shock wave device 100, which then propagates through the conductive fluid and the wall of the outer cover 102 and impacts the occluder or calcification.

[0025] In some embodiments, device 100 may include a second pair of conductors (not shown) offset 90 degrees from conductor 106. For example, if conductor 106 is located at 0 degrees and 180 degrees, the second pair of conductors may be located at 90 degrees and 270 degrees. The second pair of conductors also terminates near the distal end of device 100 and includes an uninsulated portion at its ends. A transmitting strip 108 also surrounds the ends of the second pair of conductors. Separate high-voltage pulses may be applied to both ends of the second pair of conductors to generate a second pair of arcs with the transmitting strip 108. As a result, a second set of shock waves is induced from the distal end of device 100. The first pair of conductors 106 and the second pair of conductors may be excited alternately, which can improve the effectiveness of device 100 by further spreading the shock waves.

[0026] A fluid return line 112, having an inlet near the distal end of device 100, draws conductive fluid from the internal volume, while a fluid pump (not shown) operates via a fluid inlet at the proximal end of device 100. Figure 5 (As shown in the diagram) Additional conductive fluid is pumped in. Thus, the fluid return line 112 and the fluid pump circulate the pressurized conductive fluid within the internal volume. This circulation of the conductive fluid prevents air bubbles generated by the device 100 from being trapped at the distal end of the device 100 due to the limited space within the end. Furthermore, the circulation of the conductive fluid promotes cooling of the device 100 and the treatment site.

[0027] Figure 2A side cross-sectional view of an exemplary shock wave device 100 for generating a positive shock wave according to some embodiments is depicted. For example... Figure 2 As shown, two conductors 106 (e.g., polyimide-insulated copper wires) are positioned along opposite sides of an internal member 104. Each conductor 106 includes an uninsulated conductor end 202. An insulating sheath 110 (e.g., a polyimide tube) is positioned in a region close to the uninsulated conductor end 202 to reduce the likelihood of current arcing from one conductor end to the other. A sparking strip 108 is positioned with its leading edge closer to the distal end of the device 100 than the conductor ends 202, such that two spark gaps are formed between each conductor end 202 and the sparking strip 108. The positioning of the conductor ends 202, the insulating sheath 110, and the sparking strip 108 allows current to arc from the uninsulated end of one conductor to the sparking strip 108 and then from the sparking strip 108 to the uninsulated end of the other conductor when a high-voltage pulse is applied across the two conductors 106. As a result, a shock wave is generated at the distal end of the shock wave device 100, which then propagates through the conductive fluid and the walls of the outer cover 102 to impact the occlusion or calcification. Positioning the emitting band 108 closer to the distal end of the device than the lead wire end 202 helps to facilitate the propagation of the shock wave in a generally positive direction (e.g., longitudinally from the distal end of the device 100). The shock wave can be repeatedly generated as desired by practitioners for treating vascular system areas.

[0028] Figure 3 A front cross-sectional view of an exemplary shock wave device 100 for generating a positive shock wave according to some embodiments is depicted. For example... Figure 3 As shown, the transmitting strip 108 surrounds two conductors 106 (e.g., insulated copper wires) and a fluid return line 112. The fluid return line 112 includes an inlet that draws conductive fluid from the internal volume of the device to allow the conductive fluid to circulate within the distal end of the device 100.

[0029] Figure 4 An extended side sectional view is depicted of an exemplary shock wave device 100 for generating a positive shock wave according to some embodiments. (See also...) Figure 4 As shown, in some embodiments, the outer covering of device 100 includes an angioplasty balloon 402. The balloon 402 can be inflated by pumping additional fluid into the internal volume of the device. The balloon 402 can be inflated before or after applying a shock wave to the treatment area. For example, in some embodiments, after using the radiating band 108 at the distal end of device 100 to generate a positive shock wave to break the occlusion, device 100 is further advanced into the patient's vascular system, and the balloon 402 is inflated in the occluded area to further treat that area.

[0030] In some embodiments, the shock wave device 100 may include a secondary emission strip 404 located at the center of the device 100. Figure 4 The illustrated device 100 includes two sub-emitting bands 404, but various numbers of sub-bands 404 can be used. For example, in some embodiments, device 100 may include a single sub-emitting band 404. In other embodiments, device 100 may include five or more sub-emitting bands 404. The sub-emitting bands 404 can be used with various techniques to generate shock waves. For example, the sub-emitting bands 404 can generate shock waves using low-profile or coplanar electrodes, such as those described in U.S. Patent No. 8,888,788 and U.S. Patent Application No. 15 / 346,132, which are incorporated herein by reference in their entirety. The shock wave can radiate from a central location of the sub-emitting band 404 in a generally radial direction. In some embodiments, the sub-emitting bands 404 can generate shock waves independently of the emitting bands 108 at the distal end of device 100. For example, in some embodiments, after generating a positive shock wave at the distal end of device 100 using the emitting bands 108 to break the occlusion, device 100 is further advanced into the patient's vascular system until the central location of the sub-emitting bands 404 is aligned with the occlusion area. Then, an additional shock wave can be generated from the secondary emitting band 404 to further treat the area. To allow for independent operation, an additional conductor can be provided between the high-voltage source and the second emitting band 404.

[0031] In some embodiments, plaques or occlusions in blood vessels can be treated using a positive shock wave from the emitting band 108, a radial shock wave from the sub-emitting band 404, and inflation of the angioplasty balloon 402 in various sequences and combinations. Blood vessels may include blood vessels in the patient's vascular system or ureters in the patient's urinary system.

[0032] Figure 5 An extended-length side view of an exemplary shock wave device 100 according to some embodiments is depicted. The shock wave device 100 may be in communication with a fluid source and a fluid pump (not shown), which introduces conductive fluid into the internal volume of the device 100 via a fluid inlet 502. The fluid pump can fill the internal volume with fluid to a certain pressure. This is achieved by drawing fluid in... Figure 1 and 3The fluid return line shown allows conductive fluid to circulate within the internal volume of device 100 before being expelled through waste outlet 504. Waste outlet 504 may include a pressure reducing valve to maintain fluid pressure within the internal volume of the device while conductive fluid circulates. Circulation of the conductive fluid prevents bubbles formed in device 100 from being trapped within the limited space at the distal end of device 100. Trapped bubbles may prevent subsequent shock waves from propagating from device 100, thus preventing their accumulation is beneficial. In some embodiments, waste outlet 504 may be connected to a fluid source, such that a fluid pump recirculates the waste fluid.

[0033] Figure 6 This is a flowchart of an exemplary method for generating a positive shock wave. Figure 6 As shown, a shockwave device is introduced into a blood vessel (602). The blood vessel may include a blood vessel in the patient's vascular system or a ureter in the patient's urinary system. The shockwave device may be a reference... Figure 1-5 The described device 100. A shockwave device is advanced within a blood vessel such that the distal end of the device faces a first treatment area (604). The first treatment area may include a chronic total occlusion (CTO), surrounding calcium deposits, kidney stones, or other occlusions or stones. Once the distal end of the shockwave device faces the first treatment area, high-voltage pulses are applied at both ends of the first and second leads to generate first and second shock waves from first and second spark gaps formed between the first and second leads and the emitter band (606). Due to the positioning of the first and second leads and the emitter band, the first and second shock waves propagate generally forward from the shockwave device to impact the occlusion or calcium deposit in the first treatment area. In some embodiments, the shockwave device may then be further advanced within the blood vessel such that an angioplasty balloon is aligned with either the first or second treatment area (608). The angioplasty balloon may then be inflated in either the first or second treatment area (610). In this way, conventional angioplasty balloon treatment can be applied to treat one or more treatment areas after shockwave therapy. Alternatively or additionally, in some embodiments, the shock wave device may be further advanced within the blood vessel such that a secondary emitting band at a central position of the device is aligned with the first or second treatment area (612). A third shock wave can then be generated from the secondary emitting band to apply additional shock wave treatment to the first or second treatment area (614). Steps 604-614 may be performed in various sequences or combinations and may be repeated as needed when appropriate for treating a patient.

[0034] Although the invention has been specifically shown and described with reference to its embodiments, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the scope of the invention. For all the embodiments described above, the steps of the method need not be performed in a specific order.

Claims

1. A catheter for treating vascular occlusion, comprising: Tubular internal components; Transmitter components, including: A first insulated conductor extends along the length of the tubular internal member and has a non-insulated distal end face. A second insulated wire extends along the length of the tubular inner member and has a non-insulated distal end face, the second insulated wire being offset from the first insulated wire in the circumferential direction of the tubular inner member. A conductive sheath circumferentially surrounds a first insulated wire and a second insulated wire, wherein a first spark gap extends between the distal faces of the conductive sheath and the first insulated wire, and a second spark gap extends between the distal faces of the conductive sheath and the second insulated wire; and A flexible member, hermetically attachable to the distal end of the conduit and surrounding the transmitter assembly, the flexible member being filled with a conductive fluid, wherein when the flexible member is filled with the conductive fluid and a high-voltage pulse is applied to both ends of the first and second insulated wires, first and second shock waves are generated from the first and second spark gaps.

2. The catheter according to claim 1, characterized in that, The second insulated wire is offset from the first insulated wire by 180 degrees in the circumferential direction.

3. The catheter according to claim 1, characterized in that, The distal end of the conductive sheath extends distally beyond the distal face of the first insulated wire and the distal face of the second insulated wire.

4. The catheter according to claim 1, characterized in that, The distal end of the conductive sheath is close to the distal face of the first insulated wire and the distal face of the second insulated wire.

5. The catheter according to claim 1, characterized in that, Includes an insulating sheath surrounding the tubular internal member in the region near the distal ends of the first insulated conductor and the second insulated conductor.

6. The catheter according to claim 1, characterized in that, include: A fluid pump, connected to the proximal end of a conduit and configured to provide a conductive fluid to fill the flexible member; and A fluid return line having an inlet near the distal end of a conduit and configured to remove conductive fluid from the flexible member, wherein the fluid pump and the fluid return line are configured to circulate the conductive fluid under pressure within the flexible member.

7. The catheter according to claim 6, characterized in that, This includes a pressure reducing valve located at the outlet of the fluid return line.

8. The catheter according to claim 1, characterized in that, The conductive fluid includes saline or a combination of saline and contrast agent.

9. The catheter according to claim 1, characterized in that, It includes one or more secondary conductive sheaths disposed at the middle position of the tubular internal member and configured to generate a shock wave from the middle position.

10. The catheter according to claim 1, characterized in that, The tubular internal component includes a guide wire lumen.

11. The catheter according to claim 1, characterized in that, include: A third insulated conductor extends along the length of the tubular internal member and has a non-insulated distal end face; A fourth insulated conductor extends along the length of the tubular internal member and has a non-insulated distal end face, the fourth insulated conductor being offset from the third insulated conductor in the circumferential direction of the tubular internal member; and The conductive sheath circumferentially surrounds the third insulated wire and the fourth insulated wire, a third spark gap extends between the distal surfaces of the conductive sheath and the third insulated wire, and a fourth spark gap extends between the distal surfaces of the conductive sheath and the fourth insulated wire.

12. The catheter according to claim 11, characterized in that, The fourth insulated wire is offset by 180 degrees from the third insulated wire in the circumferential direction of the tubular internal component.

13. The catheter according to claim 12, characterized in that, The third insulated wire is offset by 90 degrees from the first insulated wire in the circumferential direction of the tubular internal component.

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