Lesion Penetrating Shock Wave Catheter

Abstract

The present invention provides a catheter for treating an occlusion within a body lumen. The catheter includes a fluid-filled catheter body. An impactor is connected to the distal end of the catheter body and has a proximal end within the catheter body and a distal end outside the catheter body. The catheter also includes a shock wave source configured to generate a shock wave, and a deflector located between the shock wave source and the distal end of the catheter body and coupled to the proximal end of the impactor. When the shock wave source generates a shock wave, the shock wave impinges on the deflector, causing the deflector and the impactor to propel forward, causing the distal end of the impactor to deliver a mechanical force to the occlusion, thereby restoring flow to the body lumen.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 252,467, filed on October 5, 2021, and U.S. Provisional Application No. 63 / 349,995, filed on June 7, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates generally to the field of medical devices and methods, and more particularly to catheter devices for treating occlusions in body lumens, such as vascular or urinary tract lumens. Background Art

[0004] The present invention generally relates to a catheter for treating an occlusion within a body lumen, such as a kidney stone, a calcified lesion in the vasculature, a partial coronary artery occlusion, or a chronic total coronary artery occlusion, to restore flow within the lumen.

[0005] Chronic total occlusions ("CTOs") in the vasculature remain the "final frontier" for percutaneous interventions. When an artery is partially or completely blocked by a thrombus, plaque, fibrous plaque, or calcium deposits, interventional procedures to remove the occlusion become more dangerous for the patient and more complex and time-consuming for the physician. If left untreated, CTOs reduce blood flow to the heart and surrounding limbs and can lead to severe ischemia and amputation.

[0006] In a typical CTO intervention, the physician first passes a flexible, narrow guidewire through the blood vessel to puncture the occlusion and reach the distal true lumen of the vessel. An angioplasty balloon is then advanced over the guidewire down the vessel to the occlusion and pressurized to reduce or disrupt the calcified plaque.

[0007] Although a variety of different catheters have been developed to treat arterial disease, few commercially available devices have achieved high success rates in CTO treatment. Existing treatment systems for percutaneous coronary angioplasty or peripheral angioplasty (such as balloon catheters) are not suitable for passing through the stubborn fibrosis and calcification tissue common in CTOs. Conventional guidewires may be difficult to penetrate the thick fibrous cap of a CTO and risk damaging the vessel wall when passing through narrow and tortuous areas of the vascular system. Attempting to use a soft guidewire to penetrate a CTO may result in bending (e.g., the guidewire deviates to a subintimal channel or side branch), and when using a harder guidewire, great care must be taken to avoid penetrating the arterial wall when applying force against a complete occlusion. Even if the initial puncture using a guidewire is successful, it is very difficult to place an expansion device such as an angioplasty balloon in a chronically occluded vessel. This makes the treatment of CTO a technically challenging process that requires a long learning curve for interventional cardiologists.

[0008] Recently, catheters have been developed that include one or more shock wave sources (e.g., electrode pairs) that are used to generate shock waves within an angioplasty balloon. Shock wave devices are particularly effective for treating calcified lesions because the sound waves can rupture the lesion near the angioplasty balloon without damaging the surrounding vasculature. In these devices, a catheter can be advanced over a guidewire in the patient's vasculature until it approaches the lesion. The balloon is then inflated with a conductive fluid to contact the lesion, and a high-voltage pulse is applied between the electrode pairs to generate shock waves that direct the sound waves into the lesion. Once the lesion is ruptured, the balloon can be further inflated in the vessel to improve flow in the lumen. Efforts have been made to direct the acoustic energy of the shock wave forward to break through tighter and more difficult-to-penetrate occlusions / blockages / blockages in the vasculature. Examples of forward-firing designs can be found in U.S. Patent No. 10,966,737 and U.S. Publication No. 2019 / 0388110, both of which are incorporated herein by reference.

[0009] Although shock wave catheter designs have been used for coronary and peripheral vascular applications, even these designs have difficulty traversing chronic partial or complete occlusions in the vasculature.

[0010] Some devices currently available for treating CTOs use ultrasound, piezoelectric crystals, or linear acoustic shock wave sources to deliver mechanical energy to disrupt chronic occlusions. Typically, these devices direct strong mechanical vibrations along a guidewire to drill through fibrotic and calcified tissue in the vascular system. However, these systems require large and expensive generators to operate, and the intensity of the vibrations can make the guidewire difficult to control, risking damage to the vessel wall during treatment. Other systems use a mechanical hammer that can be guided over a guidewire to deliver mechanical energy to stable / solid CTOs. However, these systems face similar problems. Further systems direct radiofrequency energy along a guidewire to disrupt occlusions. However, radiofrequency energy generates heat and plasma within the blood vessel, and the guidewire in such systems must be carefully centered and moved continuously to avoid burning the vessel wall.

[0011] In addition to these issues, many existing systems for treating CTOs require multiple devices to complete the intervention—for example, one device to penetrate the occlusion and another to modify the calcified tissue near the vessel wall. Therefore, there is a need for a device that can penetrate resistant fibrotic and calcified tissue to treat CTOs without requiring expensive generators, multiple devices, and the risk of unnecessary vessel damage.

[0012] Occlusions that form in other parts of the body, such as kidney stones in the ureters, require similar devices. Summary of the Invention

[0013] The above objectives are achieved by a catheter that includes an impactor for delivering mechanical force directly to an occlusion / blockage within a body lumen, such as a stenotic lesion in a patient's vasculature or a kidney stone in a ureter. In some designs, the impactor is a flexible guidewire coupled to the distal end of the catheter body and having a distal tip external to the catheter body. In other examples, the impactor is a flexible hollow member with a lumen for receiving the guidewire. The proximal end of the impactor is coupled to a deflector configured to slide back and forth within the catheter body. When a shock wave is generated within the catheter body, the shock wave impacts the deflector, causing it to propel forward. The distal tip of the impactor, along with the deflector, is driven into the occlusion to deliver mechanical force to the occlusion. Repeated shock waves cause the deflector and impactor to oscillate, creating a "jackhammer effect" that ruptures the occlusion and restores flow within the lumen.

[0014] An exemplary invention provides a catheter for treating an occlusion within a body lumen. The catheter includes a catheter body having a distal end that can be filled with a fluid. The catheter also includes an impactor connected to the distal end of the catheter body, the impactor having a proximal end within the catheter body and a distal end outside the catheter body. The catheter also includes a shock wave source configured to generate shock waves, and a deflector coupled to the proximal end of the impactor between the shock wave source and the distal end of the catheter body. When the shock wave source generates a shock wave, the shock wave impinges on the deflector, causing the deflector and the impactor to be propelled forward, causing the distal tip of the impactor to deliver mechanical force to the occlusion.

[0015] An exemplary method for treating an occlusion within a body lumen includes introducing a catheter into a body lumen of a patient. The catheter includes a catheter body having a distal end, the catheter body being capable of being filled with a conductive fluid. The catheter also includes an impactor connected to the distal end of the catheter body, the impactor having a proximal end within the catheter body and a distal end external to the catheter body. The catheter also includes a shock wave source configured to generate shock waves within the catheter body, and a deflector coupled to the proximal end of the impactor between the shock wave source and the distal end of the catheter body. The method also includes advancing the catheter within the body lumen such that a distal tip of the impactor is positioned proximate to the occlusion. The method also includes applying a high-voltage pulse to the shock wave source to generate the shock wave. When the shock wave source generates the shock wave, the shock wave impinges on the deflector, causing the deflector and the impactor to be propelled forward, causing the distal tip of the impactor to impart mechanical force to the occlusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Illustrative aspects of the present invention are described in detail below with reference to the following drawings.The embodiments and drawings disclosed herein are intended to be considered illustrative rather than restrictive.

[0017] Figure 1Schematic diagram of a catheter for treating vascular stenosis according to various aspects of the present disclosure.

[0018] Figure 2 Schematic diagram of the distal end of a catheter for treating an occlusion within a body lumen according to various aspects of the present disclosure.

[0019] Figure 3 For generating a shock wave impinging on a deflector according to various aspects of the present disclosure Figure 2 Schematic diagram of the distal end of the catheter is shown.

[0020] Figure 4A is a schematic diagram of a catheter having a hollow elongated impactor according to various aspects of the present disclosure.

[0021] Figure 4B According to various aspects of the present disclosure Figure 4A Schematic diagram of the catheter with a removable guidewire inserted through the impactor.

[0022] Figure 5A is a schematic diagram of the distal end of a catheter having a tapered distal tip according to various aspects of the present disclosure.

[0023] Figure 5B is a perspective view of a tapered distal tip having splines for penetrating an occlusion, according to various aspects of the present disclosure.

[0024] Figure 5C is a perspective view of a tapered distal tip having a smooth outer surface according to various aspects of the present disclosure.

[0025] Figure 6 Schematic diagram of a catheter generating shock waves to produce mechanical oscillations of a guidewire according to various aspects of the present disclosure.

[0026] Figure 7 Flowchart of a method for treating an occlusion within a body lumen using a catheter according to various aspects of the present disclosure.

[0027] Figure 8 is a schematic diagram of the distal end of a catheter having a tapered distal tip and a bellows portion according to various aspects of the present disclosure.

[0028] Figure 9A is a schematic diagram of the distal end of a catheter having a tapered distal tip and a coaxial transmitter according to various aspects of the present disclosure.

[0029] Figure 9B An exemplary coaxial launcher shockwave source according to various aspects of the present disclosure is shown.

[0030] Figure 10ASchematic diagram of the distal end of a catheter having a rigid tapered distal tip and a flat wire transmitter according to various aspects of the present disclosure.

[0031] Figure 10B For generating a shock wave impinging on a deflector according to various aspects of the present disclosure Figure 10A Schematic diagram of the distal end of the catheter.

[0032] Figure 10C A coaxial launcher shock wave source according to various aspects of the present disclosure is shown.

[0033] Figure 11A A method for treating a total occlusion in a body lumen according to various aspects of the present disclosure Figure 10A Schematic diagram of the catheter.

[0034] Figure 11B According to various aspects of the present disclosure, a device for breaking up a completely occluded object in a body lumen is provided. Figure 10A Schematic diagram of the catheter. DETAILED DESCRIPTION

[0035] The following description is presented to enable one of ordinary skill in the art to make and use the various embodiments disclosed herein. The descriptions of specific devices, techniques, and applications are provided as examples only. Various modifications of the examples described herein will be apparent to one of ordinary skill 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 the various embodiments. Therefore, the various embodiments and aspects thereof are not intended to be limited to the examples described and shown herein, but are intended to be within the scope consistent with the claims.

[0036] The present invention generally relates to a catheter system for treating occlusions within a body lumen, such as CTOs or circumferential calcium in a patient's vasculature or kidney stones in a patient's ureters. The catheter described herein incorporates an impactor element that delivers mechanical force directly to the occlusion within the body lumen, allowing for the treatment of tighter and more difficult-to-penetrate calcified lesions and CTOs. The present invention is similar to existing intravascular lithotripsy systems in that it may include one or more shock wave sources (e.g., electrode pairs) on a catheter that enters the patient's body lumen to treat the occlusion. However, the catheter of the present invention also includes an impactor (e.g., an impact member, such as a guidewire or a flexible hollow member) connected to the distal end of the catheter body. The impactor has a proximal end coupled to a deflector within the catheter body and a distal end located outside the catheter body that is adapted to mechanically impact the occlusion. When a shock wave is generated at the shock wave source within the catheter body, at least a portion of the shock wave energy impacts the deflector, causing the deflector to be propelled forward together with the impactor. As the deflector advances within the catheter body, the distal tip of the impactor advances within the body lumen to deliver mechanical force directly to the occlusion. The distal end of the catheter body has flexible material properties that allow the impactor to advance in response to the shock wave. When the shock wave terminates, the material properties of the distal end cause the impactor and deflector to return to their initial positions within the catheter body. In some embodiments, the deflector is connected to a centering mechanism that maintains the deflector and impactor at approximately the central axis of the catheter body while allowing forward and rearward movement along the central axis.

[0037] The generation of repetitive shock waves causes the deflector to oscillate within the catheter body. The deflector transmits mechanical energy to the impactor to generate vibrations at the distal tip of the impactor, thereby creating an oscillating "jackhammer effect" that is used to clear the occlusion / occlusion from the body lumen. Advantageously, the impactor element combined with the delivery of direct mechanical force to the occlusion enables the catheter to puncture and penetrate resistant and fibrous areas in the body lumen, such as calcified and fibrotic tissue and CTOs, which are difficult to treat with traditional angioplasty methods. This allows the catheter to advance to and treat tighter areas in the body lumen, such as those that are partially or completely occluded, to restore normal flow to the lumen.

[0038] In addition to striking the deflector to generate oscillations at the impactor, at least a portion of the shock wave energy can be transmitted in a direction transverse to the catheter (e.g., propagated and / or deflected by the deflector). This transverse shock wave energy propagates through the wall of the catheter body to treat areas of the body lumen near the catheter body, such as areas of calcification that have formed on the lumen wall. In conjunction with the forward jackhammering of the impactor, this transverse shock wave energy allows the catheter to continuously treat larger areas of occluded vessels (e.g., complete occlusions distal to the catheter and calcified tissue surrounding the catheter) and can reduce the need for multiple devices during treatment of the occluded body lumen. Once the complete occlusion is disrupted (e.g., penetrated by the impactor to provide space for the distal end of the catheter body to enter), the catheter can be advanced further into the body lumen and shock wave therapy can continue to reduce the calcified tissue surrounding the catheter.

[0039] Figure 1 An exemplary catheter 10 for treating an occlusion within a body lumen is shown. Using an elongated impactor 18 or a removable guidewire 20 connected to the distal end 14 of the catheter body 12, the catheter 10 can be introduced into an occlusion within the patient's vasculature, e.g. Figure 1 During treatment, the catheter body 12 is advanced within the lumen until the distal tip of the impactor 18 abuts the occlusion and / or the distal end 14 of the catheter body 12 is positioned adjacent to a calcified region of the lumen. In some embodiments, the catheter body 12 has compliant material properties that allow the catheter to be twisted, bent, and physically manipulated to direct the catheter 10 to the occlusion site within the body lumen.

[0040] The distal end 14 of the catheter body 12 is connected to an elongated impactor 18, such as a portion of a guidewire or a hollow elongated member having a lumen sized to receive a guidewire, such as the removable guidewire 20. The distal end 14 surrounds a shock wave source 16 such that shock waves are generated in a closed system defined by the walls of the catheter body 12. The shock wave source 16 generates shock waves at a plurality of emitters (e.g., electrode pairs) to generate acoustic waves that propagate through the distal end 14 of the catheter body 12. In some embodiments, the electrode pairs can be formed from one or more insulated wires having exposed portions (e.g., exposed distal tips of the wires or portions from which insulation has been removed) and one or more conductive emitter bands (e.g., conductive metal sheaths) mounted within the catheter body 12 and surrounding the exposed portions of the wires. The electrode pairs can be arranged in a low profile / thin / low profile configuration that reduces the diameter of the distal end 14 of the catheter 10 and allows for treatment of tighter, more difficult to penetrate lesions, such as Figure 1In some embodiments, the electrode pairs can be formed by an inner conductive sheath and an outer conductive sheath mounted circumferentially around and concentric with the inner conductive sheath, each inner conductive sheath being connected to an insulated wire mounted within the catheter body 12. Alternatively, the electrode pairs can be formed by a flat coil disposed within the conductive sheath, wherein the flat coil and the conductive sheath are each connected to an insulated wire and mounted within the catheter body 12.

[0041] The exemplary catheter 10 also includes a proximal end 22 or handle that is positioned outside the patient's body lumen during treatment. The proximal end 22 includes a fluid port 26 for filling and draining the conductive fluid from the catheter body 14 (e.g., expansion and contraction). An electrical connection port 24 is also located on the proximal end 22 of the catheter 10 and is connected to the shock wave source 16 and an external pulsed high voltage source 28 (e.g., Figure 1 In some embodiments, the proximal end 22 includes an access port for receiving a removable guidewire 20 (e.g., another guidewire in addition to the impactor 18 that impacts the occlusion, which aids in inserting and advancing the catheter into a body lumen).

[0042] The catheter 10 also includes a catheter body 12 (e.g., a flexible hollow shaft) extending between a proximal end 22 (i.e., a handle) and a distal end 14 (i.e., the end of the catheter body 12 that houses the shock wave source 16 and is coupled to the impactor 18). In some cases, one or more insulated wires extend along the length of the catheter body 12 to provide a connection between the high voltage source 28 and one or more electrode pairs of the shock wave source 16. In some examples, at least a portion of the catheter body 12 includes an internal passageway that connects elements of the distal end 14 of the catheter to the proximal handle 22. For example, one or more wire lumens can be provided to carry insulated wires that electrically connect the pulsed high voltage source 28 to the electrodes of the distal shock wave source 16, and / or one or more fluid lumens (e.g., a fluid inflow lumen and a fluid outflow lumen) can be provided to transport a conductive fluid from the fluid port 26 to the distal end 14 of the catheter body 12. In some examples, such as where a removable guidewire is used to insert the catheter 10 , the catheter body 12 and / or the impactor 18 may include a guidewire lumen sized to receive the guidewire.

[0043] Figure 2-3 An exemplary catheter for treating an occlusion within a body lumen is shown, e.g., with respect to Figure 1 The catheter. Figure 2 A cross-sectional view of the distal portion of the catheter is provided. Figure 3 A cross-sectional view of a distal portion of a catheter is provided as the catheter generates shock waves to treat an occlusion within a body lumen.

[0044] refer to Figure 2 The catheter 100 includes a catheter body 120, a flexible impactor 130, a deflector 140, a centering mechanism 150, and a shock wave source 160. The impactor 130 is sealingly connected to the distal end 124 of the catheter body 120 at a seal 125 and includes a proximal end 132 within the catheter body 120 and a distal end 134 retained outside the catheter body 120, the distal end 134 having a distal tip 135 for impacting an occlusion within a body lumen. The deflector 140 is coupled to the proximal end 132 of the impactor 130 and is located between the shock wave source 160 and the distal end 124 of the catheter body 120 such that shock waves generated at the shock wave source 160 impinge on a rear surface 144 of the deflector 140. A centering mechanism 150 is coupled to the proximal end of the deflector 140 and is adapted to maintain the deflector 140 and the impactor 130 along the central axis of the catheter 100 while allowing the deflector 140 to oscillate back and forth within the catheter body 120. The centering mechanism includes a cylinder 152 mounted within the catheter body 120 and a shaft 154 configured to slide within the cylinder 152. One or more shock wave sources 160, such as one or more electrode pairs, generate shock waves within the catheter body 120 to propel the distal tip 135 of the impactor 130 into the occlusion. In some examples, such as Figure 2-3 As shown, shock wave source 160 includes a conductive emitter strip 162 mounted within the catheter and one or more insulated wires (eg, a first insulated wire 164 and a second insulated wire 166 ) extending along the length of catheter 100 .

[0045] The catheter body 120 is a hollow, elongated shaft having a proximal end (not shown) and a distal end 124. As used herein, the proximal end of the catheter body 120 refers to the end closest to the physician when the catheter 100 is in use, while the distal end 124 refers to the end of the catheter body 120 that is positioned within a body lumen near a treatment site, such as an occlusion or an area of calcified plaque in a blood vessel or a kidney stone in a ureter, and is furthest from the physician who controls the catheter 100 from outside the lumen. In some examples, the proximal end of the catheter body 120 comprises the handle of the catheter 100, for example, Figure 1 The handle shown in .

[0046] The wall of the catheter body 120 defines a cavity that surrounds the shock wave source 160 and can be filled with a conductive fluid, such as saline. The conductive fluid allows current to flow through the electrodes of the shock wave source 160 and allows shock waves to propagate from the shock wave source 160 to the deflector 140 and through the wall of the catheter body 120. In some embodiments, the conductive fluid can also contain an x-ray contrast agent to allow for fluoroscopic observation of the catheter 100 during use. Fluid can flow into and out of the catheter body 120 via a fluid inlet line and a fluid return line (not shown), respectively. The fluid inlet line can include a fluid inlet located at the proximal end of the catheter body 120 that allows fluid to flow into the catheter body 120. The fluid return line can include a fluid inlet located near the distal end 124 of the catheter body 120 that draws the conductive fluid from the interior volume of the catheter body 120. In this way, the fluid inlet line and the fluid return line circulate the conductive fluid within the interior volume of the catheter body 120. The circulation of the conductive fluid can prevent bubbles and debris generated by the shock wave source 160 from being trapped within the distal end 124 of the catheter body 120 due to the limited space within the tip. In addition, the circulation of the conductive fluid can help cool the catheter 100 and the treatment site.

[0047] The distal end 124 of the catheter body 120 (e.g., at least the distal-most 10 mm to 20 mm portion of the catheter body) is made of a flexible material such as Pebax or polyurethane. The flexible material of the distal end 124 allows the impactor 130 to advance forward in response to the generation of the shock wave and causes the impactor 130 to return backward after the shock wave terminates. The flexible material of the distal end 124 has a compliant or semi-compliant material property that allows the distal end 124 to extend or compress in response to the axial movement of the deflector 140 and the impactor 130. In some examples, the distal end 124 of the catheter body 120 is formed with a feature structure, such as a ridge or a protruding feature structure, that facilitates the extension and compression of the distal end 124 to allow the impactor 130 to advance and achieve the backward movement of the impactor 130.

[0048] The catheter body 120 (e.g., the proximal end of the catheter body 120) can be made of any desired material, for example, a low-profile flexible or semi-compliant polymer material such as Pebax or polyurethane. The distal end 124 can be integrally formed with the catheter body 120 and formed of the same material, or can be formed of a different material and attached to the remainder of the catheter body 120 by, for example, laser bonding or heat sealing. In some examples, the catheter body 120 (e.g., the proximal end of the catheter body 120) is formed of a rigid material, and the distal end 124 of the catheter body is formed of a relatively more flexible material.

[0049] In some examples, for example, to facilitate treatment of a body lumen region near and around the catheter body 120, at least a portion of the catheter body is made of a flexible material that can expand to increase the diameter of the catheter body 120. For example, at least the distal end 124 of the catheter body 120 can be formed of an expandable material. In such an example, the catheter body 120 can be inflated with a conductive fluid such that, in the expanded state, the distal end 124 contacts the surrounding wall of the body lumen and provides a space between the shock wave source 160 and the wall of the catheter body. The catheter body 120 can be inflated to a desired pressure, which can be in a range of approximately one atmosphere to approximately six atmospheres. In some examples, the diameter of the catheter body 120 in the expanded state (e.g., the diameter of the flexible or semi-compliant distal end 124 of the catheter body 120) can be approximately 10-15% larger than the diameter of the catheter body 120 in the collapsed state. However, in some examples, the diameter of the catheter body 120 in the expanded state is less than 10% larger than the diameter of the catheter body 120 in the collapsed state, or the catheter body has approximately equal diameters in the collapsed and expanded states.

[0050] Before the catheter 100 is inserted into or removed from a body lumen, the distal end 124 can be retracted to facilitate passage of the catheter body 120 through the body lumen. Additionally or alternatively, the catheter body 120 can be formed of a rigid material, such as a rigid or semi-compliant polymer that does not expand when filled with a conductive fluid.

[0051] The distal end 124 of the catheter body 120 surrounds the shock wave generator 160, thereby generating shock waves in a closed system defined by the walls of the distal end 124. Thus, the flexible material of the distal end 124 allows acoustic energy to be transmitted through the surface of the catheter body 120 and into the area of the body lumen located near the surface of the catheter body 120. In some examples, the catheter body 120 and / or the distal end 124 are formed of a heat-resistant material that is suitable for preventing unintended material rupture due to the heat generated by the shock wave source 160 during shock wave therapy.

[0052] The distal end 124 of the catheter body 120 is connected to the impactor 130 and surrounds at least a portion of the proximal end 132 of the impactor 130. The distal end 124 of the catheter body 120 is connected to the impactor 130 at a seal 125, for example, by laser bonding, heat sealing, or adhesive. In another example, the seal 125 is formed by a hole in the elastic material of the distal end 124 of the catheter body 120, the hole having a diameter smaller than the diameter of the elongated impactor 130, such that the hole compresses the periphery of the impactor 130 to maintain the impactor 130 connected to the distal end 124. In other examples, the hole can be sized to loosely maintain the impactor 130 connected to the distal end 124. Other ways of connecting the distal end 124 and the impactor 130 are also foreseeable.

[0053] As used herein, impactor 130 is an elongated, flexible, shaft-like member adapted to impact an occlusion within a body lumen to deliver mechanical force directly to the occlusion. In some examples, impactor 130 is a metal guidewire or a portion of a guidewire. In other examples, impactor 130 is a hollow tubular member having a size determined to receive a guidewire (e.g., Figure 1 The impactor 130 includes a proximal end 132 within the catheter body 120 and a distal end 134 outside the catheter body 120 (e.g., outside the catheter body 120 but within the body lumen), the distal end including a distal tip 135. The distal end 134 of the impactor 130 refers to the portion of the impactor 130 between the impactor 130 and the distal end 124 of the catheter body 120 that is distal to the seal 125, and the proximal end 132 of the impactor 130 refers to the portion of the impactor 130 between the deflector 130 and the distal end 124 that is proximal to the seal 125.

[0054] The proximal end 132 of the impactor 130 can terminate at the deflector 140. However, alternatively, the proximal end 132 can pass through the deflector 140 and terminate at the centering mechanism 150 (i.e., such that the shaft 154 of the centering mechanism 150 includes the proximal end 132 of the impactor 130). In yet another example, the proximal end 132 of the impactor 130 extends through the shaft of the catheter body 120 and, in some cases, extends to a proximal handle of the catheter 100 that is external to the body lumen (e.g., a handle that is controlled by a physician during advancement and use of the catheter, e.g., Figure 1 The handle 22 shown in FIG.

[0055] The distal end 134 of the impactor 130 remains external to the catheter body 120 and includes a distal tip 135 adapted to deliver mechanical force to an occlusion within a body lumen to disrupt and clear the occlusion. In some examples, the distal end 134 of the impactor 130 is in the range of 30 mm to 50 mm, although shorter and longer impactors are also contemplated.

[0056] The flexible impactor 130 has material properties that facilitate the advancement of the catheter 100 through a body lumen, such as a narrow, tortuous, or curved blood vessel or ureter. The material properties of the flexible impactor 130 are sufficiently rigid so that when driven into the lesion by the shock wave, it can pierce a calcified lesion, such as a CTO cap. The material properties of the impactor 130 are also sufficiently compliant to enable advancement through the lumen without damaging the soft tissue of the lumen wall (i.e., the material properties of the impactor 130 can allow the impactor 130 to twist, curve, and bend to pass through the body lumen). The material of the impactor 130 may include, for example, a metal (e.g., stainless steel, nickel, titanium, or alloys thereof). In other examples, the material of the impactor 130 may include a rigid or heat-resistant polymer, such as Teflon, parylene, PEEK (polyetheretherketone), or ULTEM (polyetherimide: PEI). In some examples, the distal tip 135 of the impactor 130 is formed from a more rigid material than the remainder of the impactor 130 (e.g., a more rigid material than the distal end 134 or the proximal end 132 of the impactor 130). In some examples, the distal tip 135 of the impactor includes a penetration feature adapted to penetrate an occlusion, such as a thick fibrous cap of a CTO.

[0057] Although Figure 2-3 The distal end of an exemplary catheter 100 and an impactor 130 are shown, but exemplary catheters may be designed with additional or alternative impact features near the distal end. For example, Figures 4A-4B Another exemplary catheter 400 is shown in which the impactor 430 is a hollow, elongated, flexible member having a longitudinal passage (eg, a guidewire lumen) for receiving a removable guidewire 490 . Figure 4A An exemplary catheter 400 having a hollow elongated impactor 430 is shown, and Figure 4B The catheter 400 is shown with a removable guidewire 490 passed through a guidewire lumen of the impactor (eg, to facilitate insertion and advancement of the catheter 400 and / or removal of the catheter 400 and insertion of an auxiliary device).

[0058] As in Figure 4A As shown in FIG, the impactor 430 can be a bendable or flexible elongated hollow member so that the impactor 430 can pass through a tortuous and complex body lumen. The impactor 430 can include, for example, a laser-cut metal tube (e.g., a laser-cut stainless steel or Nitinol tube) or a solid metal tube, but can alternatively be formed of a compliant or semi-compliant polymer. The guidewire extending through the impactor 430 is sized with a lumen that can receive a conventional guidewire. In such an example, the centering mechanism 450 (e.g., with reference to FIG. Figure 2-3The shaft 454 of the centering mechanism 150 (described above) may further include a passageway (e.g., a guidewire lumen) sized to receive a guidewire. The centering mechanism 450 may further include an O-ring protruding outwardly between the shaft 454 and the cylindrical body 452 to prevent fluid from leaking from the catheter body 420 through the impactor 430 and the hollow guidewire lumen of the shaft 454.

[0059] like Figures 5A-5C As shown, the exemplary catheter 500 may further include a tapered distal tip 570 coupled to the distal end 524 of the catheter body 520 and surrounding a portion of the impactor 530. The tapered distal tip 570 is configured to oscillate with the deflector 540 and the impactor 530 to deliver a mechanical force to the occlusion, namely, by being propelled forward in response to the generation of shock waves in the catheter body 520, and by being propelled rearward due to the flexible material properties of the distal end 524 of the catheter body. Figure 5A The distal end of an exemplary catheter 500 is shown including a tapered distal tip 570 coupled to the distal end of the catheter body. Figure 5B and 5C Perspective views of two examples of tapered distal tips 570 that may be included in exemplary catheter designs are provided.

[0060] like Figures 5A-5C As shown, the exemplary tapered distal tip 570 can be generally conical, with its outer surface tapering / tapering between the distal end 524 of the catheter body 520 and the impactor 530. The tapered distal tip 570 also includes a passageway (e.g., an impactor lumen) sized to accommodate the impactor 530, such that the impactor passes through and is connected to the distal tip 570. The tapered distal tip 570 can be formed of a relatively more rigid material than the flexible and / or expandable distal end of the catheter body 524. For example, the tapered distal tip 570 can be formed of a semi-compliant polymer or a rigid polymer. The tapered distal tip 570 can be coupled to the distal end of the catheter body 524 and / or the impactor 530 by, for example, laser bonding or heat sealing. As shown in Figures 5A-5B As shown in , the tapered distal tip 570 may also include a penetration feature 572 to facilitate piercing and passing through an occlusion in a body lumen, such as a rigid cap of a CTO. The penetration feature 572 may include, for example, longitudinal splines (e.g., ridges) extending along the outer surface of the tapered distal tip 570. The penetration feature 572 may cause the tapered distal tip 570 to impact the occlusion with an area having a relatively small surface area, thereby resulting in a relatively increased mechanical force on the occlusion compared to a distal tip having a smooth outer surface. In other examples, such as Figure 5C As shown in , the outer surface of the tapered distal tip 570 can be smooth.

[0061] Back to Figure 2-3The exemplary catheter 100 further includes a deflector 140 coupled to the proximal end 132 of the impactor 130. The deflector 140 is located between the shock wave source 160 and the distal end 124 of the catheter body 122 and includes a front surface 142 and a rear surface 144. Figure 2-3 As shown, the front surface 142 of the deflector 140 faces the distal end 124 of the catheter body 120 and is coupled to the impactor 130, while the rear surface 144 of the deflector 140 faces the shockwave source 160 and is coupled to the shaft 154 of the centering mechanism 150. When the shockwave source 160 generates a shockwave, at least a portion of the shockwave impinges on the rear surface 144 of the deflector 140, thereby causing the deflector 140 to be propelled forward (in other words, toward the distal end 124 of the catheter body 120) along with the impactor 130. In some examples, the deflector 140 is propelled by 50 μm to 100 μm when the shockwave source 160 generates the shockwave. However, in other examples, the deflector 140 is configured to be propelled by a greater or lesser distance, such as 100 μm to 200 μm, 200 μm to 500 μm, or less than 50 μm, or by increments and gradients within these ranges, in response to the generation of the shockwave.

[0062] The deflector 140 projects radially outward from the longitudinal axis of the catheter 100 toward the wall of the catheter body 120 (e.g., outward from the impactor 130 and / or the shaft 154). The deflector includes a distal front surface 142 facing the distal end 124 of the catheter body 120 and a proximal rear surface 144 facing the proximal end of the catheter body 120. The deflector 140 can be generally disc-shaped, or as Figure 2-3 As shown, the deflector 140 may have a generally cylindrical shape, wherein the front surface 142 and the rear surface 144 join at a circumferential edge around the deflector 140. In some examples, the front surface 142 of the deflector 140 is curved or non-linear, for example, having a convex curved shape. In some examples, the front surface 142 or the rear surface 144 of the deflector 140 is shaped to reduce the resistance caused by the forward propulsion of the deflector 140 (in other words, to reduce the fluid resistance when the deflector 140 oscillates in the conductive fluid within the catheter 120). The rear surface 144 of the deflector 140 may also be curved or non-linear, for example, having a concave curved shape. The diameter of the deflector 140 may be approximately equal to the diameter of the catheter body 120. However, in other examples, the diameter of the deflector 140 is smaller than the diameter of the catheter body 120 so as to provide a gap between the periphery of the deflector 140 and the wall of the catheter body 120 (in other words, a gap through which fluid can flow when the deflector 140 oscillates back and forth within the catheter body 120).

[0063] Figure 6A perspective cross-sectional view of the distal end of an exemplary catheter 600 is provided, showing a deflector 640 that deflects shock waves generated by a shock wave source 660 within the catheter body 620. Figure 6 As shown, when the shock wave source 660 generates a shock wave, at least a portion of the shock wave impinges on the rear surface 644 of the deflector 640. At least a portion of the shock wave impinging on the rear surface 644 of the deflector 640 is deflected in a direction transverse to the catheter 600, in other words, in a direction orthogonal to the central axis of the catheter body 620. In such an example, the initial shock wave can be directed in a forward direction, while the deflected shock wave can be deflected in a direction transverse to the catheter 600. The deflected shock wave energy can propagate through the conductive fluid and the wall of the distal end 624 of the catheter body 620 to deliver acoustic energy to treat the calcified area of the body lumen surrounding the catheter body 620.

[0064] The proportion of shock wave energy directed to either destination (i.e., the ratio of the amount of shock wave energy that causes the deflector 640 to propel forward to the amount of shock wave energy that is deflected in a direction transverse to the catheter body 620) can be determined by the deflector angle 646 between the deflector 640 and the impactor 630. Figure 6As shown, the deflector angle 646 is the angle between the longitudinal axis of the catheter 600 (which can be understood as passing through the axial center of the catheter body 620, the proximal end 632 of the impactor 630, or the central longitudinal axis of the shaft 654) and the rear surface 644 of the deflector 640. In some cases, such as when the rear surface 644 of the deflector 640 is non-linear, the deflector angle 646 is the angle between the longitudinal axis of the catheter body 620 and a linear approximation of the rear surface 644 of the deflector 640. The deflector angle 646 can be selected to provide a desired amount of therapy through forward advancement of the impactor 630 or transmission of acoustic waves through the wall of the catheter body 620. More specifically, the deflector angle 646 can be selected to provide a first desired proportion of shock wave energy directed to advance the impactor 630 (i.e., forward shock wave energy) and a second desired proportion of shock wave energy directed in a lateral direction of the catheter body 620 (i.e., lateral shock wave energy). For example, a 90-degree deflector angle 646, i.e., an embodiment in which the rear surface 644 of the deflector 640 protrudes at a 90-degree angle relative to the longitudinal axis of the catheter body 620, will result in a maximum amount of shock wave energy being directed to propel the impactor 630 (i.e., a maximum amount of shock wave energy directed forward, with little or no energy directed laterally). A deflector angle 646 of approximately 135 degrees, i.e., an embodiment in which the rear surface 644 of the deflector 640 protrudes at an obtuse angle of 135 degrees relative to the longitudinal axis of the catheter body 620, can result in a maximum amount of shock wave energy being directed in a direction transverse to the catheter (i.e., a maximum amount of transverse shock wave energy). In some examples, the deflector angle 646 between the deflector 640 and the impactor 630 is between 90 degrees and 180 degrees, or an angle increment or gradient within this range. In other examples, the deflector angle 646 between the deflector 640 and the impactor 630 is in the range of 120 degrees to 150 degrees. In yet another example, the deflector angle 646 between the deflector 640 and the impactor 630 is approximately 135 degrees.

[0065] The deflector 640 can be formed from any desired material, but is more preferably formed from a material that reflects sound waves. For example, the deflector 640 can include a rigid material, such as a rigid and / or heat-resistant polymer material such as PEEK (polyetheresterketone) or ULTEM (polyetherimide: PEO), or some combination thereof, a metal, or some other rigid or semi-rigid material. In some examples, the deflector 640 is formed from the same material as the flexible impactor 630 or the shaft 654 of the centering mechanism 650. However, in other examples, the deflector 640 is formed from a different material and can be, for example, laser bonded or heat sealed to the impactor 630 and / or shaft 654.

[0066] Back to Figure 2-3In some examples, the catheter 100 includes a centering mechanism 150 configured to maintain the proximal end 132 of the impactor 130 and the deflector 140 at approximately the axial center of the catheter body 120 (i.e., along the longitudinal axis of the catheter) while allowing the deflector 140 to move axially forward and backward. The centering mechanism 150 can be formed by a cylindrical body 152 mounted within the catheter body and a shaft 154 mounted to the proximal end of the deflector 140, the shaft 154 being configured to slide within the cylindrical body 152. When the shock wave source 160 generates a shock wave, the shaft 154, along with the deflector 140 and the impactor 130, slides forward within the cylindrical body 152. The shaft 154 optionally includes a spacer 156 that projects outwardly between the shaft 154 and the wall of the cylinder 152 to maintain the shaft 154 at approximately the axial center of the cylinder 152 while allowing the shaft 154 to move forward and rearward along the central axis of the catheter body 120.

[0067] The cylinder 152 can be mounted at any desired location within the catheter body 120. For example, Figure 2-3 As shown, the cylinder 152 can be mounted proximally of the deflector 140 along a generally central axis of the catheter body 120. However, in other examples, the cylinder 152 can be mounted distally of the deflector 140, in other words, within the catheter body 120 between the deflector 140 and the distal end 124. In some examples, the cylinder 152 is mounted in an offset position such that the cylinder 152 is not concentric with the longitudinal axis of the catheter body 120. In some examples, the cylinder 152 is mounted between one or more insulated wires (e.g., the first insulated wire 164 and the second insulated wire 166) and can optionally be coupled to one or more of the insulated wires. In some examples, the catheter body 120 is provided with one or more lumens extending along the length of the catheter body 120, and the centering mechanism 150 includes a shaft 154 configured to slide within the lumen of the catheter body 120.

[0068] The shaft 154 is generally cylindrical and extends from the rear surface 144 of the deflector 140 generally parallel to the longitudinal axis of the catheter body 120. In some examples, the proximal end 132 of the impactor 130 forms the shaft 154 of the centering mechanism 150. In this regard, the length of the impactor 130 can pass through the deflector 140 to provide the shaft 154 to slide within the cylindrical body 152. In other examples, the shaft 154 can be coupled to the deflector 140 by, for example, laser bonding, heat sealing, adhesives, or some other attachment method. In some examples, such as Figure 2-3As shown, the shaft 154 is proximal to the rear surface 144 of the deflector 140. However, in other examples, the shaft 154 is disposed between the deflector 140 and the distal end 124 of the catheter body 120 (i.e., coupled to the front surface 142 of the deflector 140 or comprising a portion of the impactor 130 that extends distally of the deflector 140 between the deflector 140 and the distal end 124 of the catheter body 120).

[0069] The shaft 154 of the centering mechanism 150 is sized to slide loosely within the cylindrical body. For example, the diameter of the shaft 154 can be approximately equal to the diameter of the cylindrical body 152, or the diameter of the shaft can be slightly smaller than the diameter of the cylindrical body 152, thereby providing a gap between the shaft 154 and the cylindrical body 152 through which fluid can flow as the shaft 154 is advanced forward and backward within the cylindrical body 152. Additionally or alternatively, the shaft 154 includes a spacer 156 that protrudes outwardly between the shaft 154 and the wall of the cylindrical body 152. The spacer 156 is adapted to maintain the shaft 154 approximately centered within the cylindrical body 152 while allowing the shaft 154 to move along the central axis of the catheter body 120. In some examples, the spacer 156 protrudes outwardly from the shaft 154 in an annular or flattened cylindrical shape. In some examples, the spacer 156 includes holes or cutouts that allow fluid to flow around the spacer 156 when the spacer 156 and shaft 154 are advanced forward and backward within the cylinder 152, or in other words, when a shock wave is generated that causes the deflector 140, shaft 154, and spacer 154 to oscillate within the catheter body 120. The cutouts can be positioned at equal distances around the circumference of the spacer 156. In some examples, the centering mechanism 150 includes two or more spacers 156.

[0070] The catheter 100 also includes a shock wave source 160 configured to generate shock waves in the conductive fluid within the catheter body 120. The distal end 124 of the catheter body 120 surrounds the shock wave source 160 such that shock waves generated at the shock wave source 160 propagate through the wall of the catheter body 120 to treat a body lumen region proximate the distal end 124. The shock wave source 160 is positioned proximal to the rear surface 144 of the deflector 140 such that when the shock wave source 160 generates shock waves, at least a portion of the shock wave energy impinges on the deflector 140.

[0071] like Figure 3As shown, the repetitive shock waves cause the deflector 140 to oscillate back and forth within the catheter body. The axial oscillations of the deflector cause the attached impactor 130 to oscillate in a corresponding axial (i.e., forward and backward) direction, thereby creating a "jackhammer" effect that can penetrate occlusions within the body lumen. The distal tip 135 of the impactor 130, which remains external to the catheter body 120, vibrates in response to the repetitive shock waves at the shock wave source 160 and further disrupts the occlusion. The combination of the "jackhammer" effect and the vibrations of the distal tip 135 of the impactor 130 can penetrate the fibrous cap of the CTO and modify calcified areas of the body lumen to restore flow within the body lumen.

[0072] In some examples, shockwave source 160 generates shockwaves at a frequency of 10 Hz to 100 Hz (i.e., the generated shockwaves have a repetition rate of 10 Hz to 100 Hz), thereby causing deflector 140 to oscillate at a frequency of approximately 10 Hz to 100 Hz. In such examples, impactor 130 may vibrate or "jackhammer" at a frequency of 10 Hz to 100 Hz in response to the shockwaves. However, shockwaves may be generated at a higher or lower repetition rate depending on, for example, the size of the lesion, the extent of calcification, the size of the blood vessels, the attributes of the patient, or the stage of treatment.

[0073] As used herein, shock wave source 160 comprises one or more electrode pairs, each electrode pair comprising a first electrode and a second electrode separated by a gap. Shock waves are generated at shock wave source 160 by applying a high voltage pulse between the first and second electrodes of the pair. Each pulse initially ionizes the conductive fluid in catheter body 120 near the electrodes. At some point, a plasma arc forms across the gap between the electrode pairs, creating a low-impedance path for free current flow. Thermal energy from the plasma arc heats the conductive fluid, generating rapidly expanding vapor bubbles. The expansion of the vapor bubbles generates acoustic shock waves that propagate through the conductive fluid within catheter body 120.

[0074] The electrode pairs can be formed from the side edges of a conductive transmitter strip (e.g., a conductive sheath or ring electrode) and a conductive portion of a wire, as described in the assignee's prior application, U.S. Publication No. 2019 / 0150960. The conductive portion of the wire can be formed by removing a portion of the insulation of the insulated wire near the distal end of the wire to expose the conductive portion of the wire. The position, size, and shape of the removed portion can be varied to control the position, direction, and / or amplitude of the shock wave. In some embodiments, the electrodes can be formed by cutting the end of the insulated wire to expose the conductive cross-section (i.e., the exposed distal tip of the wire).

[0075] The electrode pairs can be arranged in a low-profile configuration that reduces the diameter of the distal end 124 of the catheter body 120 to allow treatment of tighter, more difficult-to-traverse lesions, such as CTOs. In some examples, the shock wave source 160 includes one or more coplanar electrode pairs, or one or more electrodes at least partially surrounded by a conductive emitter ribbon. In some examples, flat wire is used rather than round wire to further reduce the cross-section of the electrode assembly.

[0076] The present assignee has developed a number of low-profile / thin shock wave electrodes that may be suitable for use in treating occlusions such as catheters for CTOs. For example, in U.S. Publication No. 2019 / 0150960, the assignee discloses a thin / low-profile electrode assembly in which the outer electrode is formed by a conductive sheath and the inner electrode is formed by a conductive portion of an insulated wire (e.g., the exposed distal tip of the wire, or a portion of the wire from which the insulation has been removed by removing the insulation from the wire). The inner electrode is placed at a controlled distance from the side edge of the conductive sheath to allow reproducible arcing at a given current and voltage.

[0077] Recently, the assignee has developed a number of coplanar electrode assemblies for catheters. A variety of different coplanar electrode configurations are described in U.S. Patent Nos. 8,888,788; 10,966,737; 10,555,744; and U.S. Publication No. 2019 / 0150960, which are incorporated herein by reference. These designs provide novel configurations of electrode pairs having, for example, spiral structures and tongue-and-groove designs, in which the corresponding electrodes are on the same transverse plane to limit the total thickness of the electrode assembly. These assemblies are particularly advantageous for generating shock waves in tight, difficult-to-pass lesions or completely occluded vascular systems. For example, in U.S. Patent No. 9,993,292 and U.S. Publication No. 2018 / 0098779, which are incorporated herein by reference, the assignee discloses forming electrode pairs from a spirally wound wire to generate shock waves at each gap positioned circumferentially around a tubular structure. In US Patent No. 10,555,744, also incorporated herein by reference, the assignee discloses a tongue-and-groove electrode assembly in which electrode pairs are formed by groove-shaped cutouts in a conductive sheath and coplanar tongue-shaped protrusions extending into the groove-shaped cutouts.

[0078] Back to Figure 2-3, the exemplary catheter 100 includes a first insulated wire 164 extending along the length of the catheter 100, a second insulated wire 166 extending along the length of the catheter 100, and a conductive transmitter strip 162 mounted within the catheter 100. Each of the first and second insulated wires 164, 166 can be an insulated wire, wherein the conductive metal can be copper, aluminum, stainless steel, molybdenum, tungsten, or a combination thereof. Each of the first and second insulated wires 164, 166 includes a non-insulated conductive portion, such as an exposed distal tip of the wire, which serves as a first electrode of the electrode pair.

[0079] A conductive transmitter ribbon 162 surrounds the exposed distal tips of the first and second insulated wires 164, 166 and serves as the second electrode of the electrode pair. The conductive transmitter ribbon is mounted within the interior volume of the catheter body 120 and surrounds the ends of the two insulated wires 164, 166 without contacting the wires. The conductive transmitter ribbon 162 can be a conductive cylinder, such as a metal cylinder comprising stainless steel, tungsten, platinum, iridium, or alloys thereof. In some examples, the transmitter ribbon 162 is mounted in the catheter body 120 at a location more distal than the exposed distal tips of the first and second insulated wires 164, 166 to encourage shock waves to propagate in a generally forward direction (e.g., toward the rear surface 144 of the deflector 140 and the distal end 124 of the catheter body 120).

[0080] In such examples, Figure 2-3 As shown, shock wave source 160 includes two electrode pairs, with each respective pair of electrodes formed from conductive portions of insulated wires 164, 166 and a conductive emitter strip 162 mounted within catheter body 120. More specifically, shock wave source 160 may include a first electrode pair including a first electrode formed from the exposed distal tip of first insulated wire 164 and a second electrode formed from conductive emitter strip 162. Shock wave source 160 may also include a second electrode pair including a first electrode formed from the exposed distal tip of second insulated wire 166 and a second electrode formed from conductive emitter strip 162.

[0081] The catheter 100 also includes a voltage source (e.g., Figure 1The generator 28 shown in FIG. 1 is configured to deliver a high-voltage pulse to the shock wave source 160. When the high-voltage pulse is applied to the first and second insulated wires 164, 166, current is configured to flow from the exposed distal tip of the first insulated wire 164 to the conductive transmitter strip 162, thereby generating a first shock wave on the first electrode pair. The current is also configured to flow from the conductive transmitter strip 162 to the exposed distal tip of the second insulated wire 166, thereby generating a second shock wave on the second electrode pair. In some examples, the voltage source is configured to deliver the high-voltage pulse at a voltage in the range of 100V to 3000V, or more specifically, at a voltage in the range of 2300V to 3000V. In other embodiments, the voltage source may be configured to deliver the high-voltage pulse at a voltage in the range of 100V to 10,000V, as well as voltage increments or gradients within this range. Furthermore, the voltage source may be configured to deliver the high-voltage pulse at a desired repetition rate, such as at a rate of 10Hz to 100Hz. However, the voltage source can be configured to deliver voltage pulses at any desired voltage and repetition rate on the shock wave source 160. In some examples, the voltage source can be controlled by the physician during treatment to deliver higher or lower voltage pulses, or higher or lower voltage pulse repetition rates, as desired. For example, the physician can begin with low-energy shock waves and increase the energy as needed during treatment. Alternatively, the physician can begin with high-energy shock waves, such as to rupture a fibrous CTO cap with the impactor 130, and can reduce the energy as needed for the remainder of the treatment. The amplitude of the shock waves can be varied by controlling the voltage, current, duration, and repetition rate of the pulse voltage from the pulse voltage source. More information on the physics of shock wave generation and its control can be found in U.S. Patents Nos. 8,956,371; 8,728,091; 9,522,012; and 10,226,265, each of which is incorporated by reference.

[0082] In some examples, the catheter 100 includes an insulating sheath (e.g., a polyimide insulating ring) mounted within the catheter body 120 between the conductive transmitter strip 162 and the exposed distal tips of the insulated wires 164, 166. The insulating sheath can be mounted concentrically within the interior of the conductive transmitter strip 162 and can be adapted to prevent unintended current flow and leakage between electrodes in the catheter body 120 (e.g., between the conductive portions of the insulated wires 164, 166 and the conductive transmitter strip 162). The insulating sheath can include apertures located between electrodes of a corresponding electrode pair, such that the insulating sheath provides a path for current to flow between the conductive transmitter strip 162 and the conductive portions of the insulated wires 164, 166, the path flowing through the apertures of the insulating sheath.

[0083] The position and spacing of the electrode pairs (e.g., conductive emitter strip 162 and insulated wires 164, 166) can be controlled to provide more effective shock wave therapy. For example, the electrode pairs of shock wave source 160 can be circumferentially spaced at uniform increments inside distal end 124 of catheter body 120, such as 180 degrees or 90 degrees apart, to generate shock waves more evenly around catheter 100. For example, while Figure 2-3 The catheter shown in FIG1 includes a first insulated wire 164 and a second insulated wire 166, but catheter 100 may have more than two wires and may be configured to generate shock waves at more than two electrode pairs. In a specific example, the catheter may include a second pair of insulated wires (not shown) offset 90 degrees from the first and second insulated wires 164, 166. For example, if the first and second insulated wires 164, 166 are located at 0 degrees and 180 degrees, the third and fourth insulated wires may be located at 90 degrees and 270 degrees. The third and fourth insulated wires also terminate near the distal end of the catheter body and include exposed conductive distal tips that serve as electrodes. A conductive transmitter tape (e.g., conductive transmitter tape 162 or another transmitter tape) surrounds the exposed distal tips of the third and fourth insulated wires, and a separate high-voltage pulse may be applied to the third and fourth insulated wires to generate a second pair of shock waves between the insulated wires and the transmitter tape. As a result, a second set of shock waves may be generated from the catheter's third and fourth electrode pairs, which are formed by the conductive transmitter tape and the conductive portions of the third and fourth insulated wires. The first pair of insulated wires (ie, first insulated wire 164 and second insulated wire 166) and the second pair of insulated wires (ie, third insulated wire and fourth insulated wire) may be alternately activated, which may increase the effectiveness of the device by propagating the shock wave further around the circumference of the catheter.

[0084] In some embodiments, the shock wave source 160 includes electrode pairs located in different longitudinally spaced groupings within the catheter body 120. For example, to generate shock waves at a more central location within the catheter body 120, i.e., to advantageously treat a larger area of the body lumen around the catheter body 120, the catheter 100 may include one or more intermediate shock wave sources. A distal shock wave source (e.g., shock wave source 160) may be configured to generate shock waves to advance the deflector 140 and the impactor 130 to treat an occlusion distal to the catheter body 120 (wherein a portion of the shock wave energy is also directed in a lateral direction of the catheter 100 to treat the body lumen area around the distal end 124 of the catheter body 120), while an intermediate shock wave source may be configured to generate shock waves to treat the body lumen area around the central portion of the catheter body 120. In some examples, the catheter 100 includes a second conductive transmitter strip mounted at an intermediate position of the catheter body 120 (e.g., at a position proximal to the conductive transmitter strip 162), and an associated pair of insulated wires (e.g., the third and fourth insulated wires described above) spaced apart from the second transmitter strip to form respective first and second intermediate electrode pairs for generating shock waves. When a high voltage pulse is applied to the third and fourth insulated wires, current is configured to flow from the exposed distal tip of the third insulated wire to the second conductive transmitter strip to generate a first intermediate shock wave on the first intermediate electrode pair. The current is also configured to flow from the second conductive transmitter strip to the exposed distal tip of the fourth insulated wire to generate a second intermediate shock wave on the second intermediate electrode pair.

[0085] Any number of conductive emitter strips can be used to generate shock waves at various locations along the length of the catheter body 120. For example, in some examples, the catheter 100 includes three, four, or five conductive emitter strips spaced along the length of the catheter body 120, and associated insulated wire pairs spaced apart from the respective strips to form respective electrode pairs for generating shock waves. In some examples, a second or additional emitter strip can generate shock waves independently of the emitter strip at the distal end of the device.

[0086] All of the above-described shock wave sources include an electrode pair and a high-voltage source for generating electrohydraulic shock waves across the gap between the electrodes. Other types of shock wave sources are also within the scope of the present invention. For example, it is well known that focused lasers can generate shock waves in fluids. Laser light can be transmitted from an external laser device into the catheter body via an optical fiber. The optical fiber can extend along the catheter in a lumen similar to line 164 or 166. In operation, a high-energy laser pulse is injected into the proximal end of the optical fiber and output from the distal end. The distal end of the optical fiber will be located in the area behind the deflector 140. The pulse vaporizes the fluid, generating a shock wave that impacts the surface 144 of the deflector 140. In use, the laser pulses are generated, forming a series of shock waves that oscillate the guidewire and jackhammer the occlusion. Lasers with high saline or water absorption coefficients are particularly interesting because they generate more efficient shock waves. A high absorption coefficient corresponds to a shallow absorption depth, so the laser energy is confined to a small depth in the fluid, resulting in very rapid heating and vaporization of the fluid. Examples of preferred lasers include Ho:YAG (2120 nm), Tm:YAG (2010 nm), Tm fiber laser (1940 nm), and Er:YAG (2940 nm).

[0087] Figure 7 FIG. 7 is a flow chart of an exemplary method 700 for treating an occlusion within a body lumen, such as a kidney stone or CTO in a patient's ureter or circumferential calcium in a patient's blood vessel. Figure 7 As shown, a catheter is introduced into a body lumen (702) of a patient, such as a blood vessel in the patient's vascular system or a ureter in the patient's urinary system. The catheter may be a catheter as described herein. Figure 1-3 , 4A-4B, 5A-5C, 6, 8, 9A, or 10A. More particularly, the catheter includes at least one catheter body having a distal end, the catheter body being capable of being filled with a conductive fluid; an impactor coupled to the distal end of the catheter body, the impactor having a proximal end within the catheter body and a distal end outside the catheter body; a shock wave source configured to generate a shock wave; and a deflector positioned between the shock wave source and the distal end of the catheter body and coupled to the proximal end of the impactor.

[0088] In operation, a physician may introduce a catheter into a patient's body lumen by first inserting the impactor into the patient's entry site (e.g., an artery in the groin area of the leg), and then manipulating the catheter body and handle to advance the catheter through the body lumen to the target treatment area (e.g., an area where an occlusion needs to be ruptured to restore flow within the lumen). Additionally or alternatively, for example, in an example where the impactor includes a guidewire lumen, the physician may first insert a removable guidewire through the guidewire lumen and into the body lumen. The physician may then advance the catheter into the body lumen over the removable guidewire and toward the target treatment area.

[0089] The catheter is then advanced within the body lumen such that the distal end of the impactor is positioned adjacent to the occlusion within the body lumen (704). Figure 1 As shown in , the catheter can be advanced until the distal end of the impactor is against the occlusion or at least partially within the occlusion. Additionally or alternatively, the catheter can be advanced until the distal end of the catheter body is positioned near the calcified area of the lumen (i.e., the shock wave therapy is delivered through the wall of the catheter body). If the catheter has been advanced over a removable guidewire, the doctor can optionally remove the guidewire. However, in other examples, the doctor can retain the removable guidewire in the catheter during treatment (e.g., retaining the guidewire in the lumen of the impactor and / or flush with the distal tip of the impactor to prevent debris and tissue from entering the impactor).

[0090] The catheter body is then filled with a conductive fluid (e.g., saline or saline mixed with a contrast agent) such that the fluid covers the shock wave source (e.g., one or more electrodes). In some cases, the catheter is filled until the conductive fluid at least partially expands the catheter body. Once the distal end of the impactor is positioned near the occlusion and the catheter body is filled with the conductive fluid, a series of shock waves can be generated within the catheter body (706). The series of shock waves impinge on the deflector, causing the deflector to advance along with the impactor, causing the distal end of the impactor to deliver a mechanical force to the occlusion for each shock wave generated. In some examples, the shock wave source includes one or more electrode pairs, and generating the series of shock waves includes applying a high voltage pulse to the one or more electrode pairs. In another example, the shock wave source is a laser, and generating the series of shock waves includes delivering high energy laser pulses using the laser. Between each shock wave in the series, the flexible material properties of the distal end of the catheter body cause the impactor and deflector to return to their initial positions within the catheter body. As described above, the repeated shock waves cause the impactor to oscillate and vibrate to penetrate and clear the occlusion and restore flow within the body lumen.

[0091] Repeatedly advancing the catheter through the target area of the body lumen and applying repeated shock wave cycles can clear even rigid and chronic occluded areas of the body lumen. For example, in some examples, the method further includes advancing the catheter within the body lumen so that the distal tip of the impactor is adjacent to another treatment area, such as a more distal occluded area of the CTO or a more distal calcified or partially occluded area of the vasculature. The method can then include generating another series of shock waves. As described above with reference to Figures 5A-5CAs described, in some examples, the catheter includes a tapered distal tip that is configured to be advanced along with the impactor and deflector in response to the generation of shock waves. The tapered distal tip can be used to deliver mechanical force to a portion of the occlusion that is located more proximal to the catheter body (i.e., an area of the lumen that is more proximal than the distal tip of the impactor) to continue penetrating and clearing the occlusion. In such an example, the method may include further advancing the catheter within the body lumen so that the tapered distal tip is positioned near a treatment area (708), for example, a treatment area previously penetrated by the impactor. The method may then include generating another series of shock waves (710) to advance the tapered distal tip into the occlusion.

[0092] In one or more examples, after generating another series of shock waves to advance the tapered distal tip into the occlusion (708), method 700 can again advance the catheter further within the body lumen so that the tapered distal tip is positioned near another treatment area (710) before generating another series of shock waves (710). In other words, in one or more examples, after step 710, method 700 can cyclically repeat steps 708 and then 710. Optionally, the cycle of repeating steps 708 and 710 can be repeated multiple times.

[0093] To eliminate the need for multiple devices during treatment of an occlusion, the same catheter can be used to modify calcified and partially occluded areas near the catheter body by delivering acoustic shock wave energy (e.g., transverse shock waves) through the walls of the catheter body. For example, after using an impact from the distal tip of the impactor to modify a fully or partially occluded area of the lumen, method 700 can further include advancing the catheter further within the body lumen so that the catheter body is positioned adjacent to a laterally located treatment area (e.g., an occlusion previously penetrated by the impactor or some other calcified or partially occluded area) (712). After further advancing the catheter within the body lumen, the method can include generating a transversely directed shock wave (714) to deliver the acoustic shock wave energy to the laterally located occlusion. The transverse shock wave energy can propagate through the walls of the catheter body to treat an area of the body lumen adjacent to the catheter body. In one or more examples, when the catheter is advanced in step 712 so that the catheter body is positioned adjacent to the laterally located treatment area, the distal tip can also be positioned adjacent to another treatment area. In this case, when generating a laterally directed shock wave at step 714 , in addition to transmitting the shock wave energy in a lateral direction of the catheter, at least a portion of the shock wave energy may be transmitted to generate oscillations that propel the distal end of the impactor.

[0094] In one or more examples, after generating the laterally directed shockwave in step 714, method 700 can again advance the catheter further within the body lumen so that the catheter body is positioned adjacent to the laterally positioned treatment region (714) before generating the laterally directed shockwave again (714). In other words, in one or more examples, after step 714, method 700 can cyclically repeat step 712 and then step 714. Optionally, the cycle of repeating steps 712 and 714 can be repeated multiple times.

[0095] In some examples, treating an occlusion within a body lumen may include one or more treatment phases. For example, during initial treatment of a tightly or completely occluded area of the lumen, the first treatment phase may involve penetrating the occlusion with the distal tip of the impactor to restore flow in the lumen. Once the occluded area is wide enough to allow passage of the catheter body, the catheter body may be further advanced into the occluded area. During a subsequent second treatment phase, additional shock waves may be generated to deliver additional shock wave energy to the lumen area surrounding the catheter body. The physician may vary the voltage and repetition rate of the shock waves during different treatment phases as needed.

[0096] If the catheter includes more than one shock wave generator (e.g., a distal electrode pair and an intermediate electrode pair), a first treatment phase may include generating shock waves at the first (e.g., distal) electrode pair, and a second treatment phase may include generating shock waves at the second (e.g., proximal) electrode pair. During the first treatment phase, only the distal electrode pair may generate shock waves to advance the impactor, thereby delivering mechanical force to the occlusion within the body lumen. After the occlusion has been altered (e.g., the rigid CTO cap has been penetrated by the distal tip of the impactor), the catheter may be advanced further into the occlusion, and additional electrode pairs may be activated to generate more intermediate shock waves.

[0097] In other examples, the catheter can be removed from the body lumen and replaced with an assistive device to continue treatment.The assistive device can be inserted over a guidewire (eg, the removable guidewire described above or another guidewire) and advanced into the target area of the body lumen.

[0098] Figure 8 An exemplary catheter 800 with a bellows portion 880 for treating an occlusion in a body lumen is shown, e.g., with respect to Figure 1 Similar to the catheter described above, such as Figure 8 As shown, catheter 800 includes a deflector 840, a centering mechanism 850, a catheter body 820, a flexible impactor 830, and a shock wave source 860, which may be configured / structured as described above.

[0099] like Figure 8As shown, the catheter 800 includes a bellows 880 located on the wall of the catheter body 820. In some embodiments, the bellows 880 can be formed by an accordion-like folded portion of the wall of the catheter body 820 that provides axial cushioning, allowing the front portion of the catheter body 820 to translate axially (e.g., to the right and to the left). In some embodiments, the bellows 880 can enable the catheter body 820 to be stretched to a stretched position by flattening the bellows 880, and to return to an unstretched position in which the bellows 880 is folded into place. Thus, in some embodiments, the bellows 880 can allow the distal end 824 of the catheter body 820, and more specifically, the portion of the catheter body 820 located between the distal end 824 and the bellows 880, to move in a forward direction when the bellows 880 is stretched. In some embodiments, as the portion of the catheter body 820 between the bellows 880 and the distal end 824 moves, the portion of the catheter body 820 between the proximal end of the catheter 800 and the bellows 880 will remain stationary. In some embodiments, the bellows 880 can be formed of a flexible or semi-compliant material, which enables the folds of the bellows 880 to stretch and flatten as described above.

[0100] The shock wave source 860 of the catheter 800 can be configured as described above. For example, the shock wave source 860 can be configured to generate shock waves in the conductive fluid within the catheter body 820, which propagate through the wall of the catheter body 820 to treat the body lumen region near the distal end 824 of the catheter 800. As described above, the repetitive shock waves generated by the shock wave source 860 can cause the deflector 840 to oscillate back and forth within the catheter body 820. Furthermore, the axial oscillations of the deflector 840 can induce corresponding axial (i.e., forward and backward) oscillations in the attached impactor 830, thereby creating a "jackhammer" effect that can penetrate occlusions within the body lumen. The distal tip 835 of the impactor 830 can vibrate in response to the repetitive shock waves from the shock wave source 860, thereby further disrupting the occlusion. In some embodiments, the distal tip 835 of the impactor 830 and the portion of the catheter between the bellows 880 and the distal end 824 can vibrate in response to repetitive shock waves from the shock wave source 860. The "jackhammer" effect and / or vibrations of the distal tip 835 and / or the vibrating portion of the catheter 800 can penetrate the fibrous cap of the CTO and modify the calcified region of the body lumen to restore flow within the body lumen.

[0101] The shock wave source 860 may include one or more electrode pairs, wherein each electrode pair includes a first electrode and a second electrode separated by a gap. Figure 8 As shown in , the electrode pairs of shock wave source 860 are formed by the side edges of a conductive emitter strip (eg, a conductive sheath or ring electrode) and the conductive portion of the wire.

[0102] Alternative electrode configurations are suitable for use with catheters according to the present invention. For example, Figure 9A The catheter 900 depicted in FIG. 1 relies on a shock wave source 960 having a coaxial emitter. The catheter 900 can otherwise be configured similarly to the above-described catheter 800. The coaxial emitter of the shock wave source 960 can be formed by an outer conductive sheath mounted circumferentially around and concentric with an inner conductive sheath, the outer conductive sheath and the inner conductive sheath each being connected to an insulated wire.

[0103] exist Figure 9B 9. An exemplary coaxial launcher-type shock wave source, such as a shock wave source 960 of catheter 900, is shown in FIG. Shock wave source 960 includes a first cylindrical conductive sheath configured as an inner conductive sheath 930 and a second cylindrical conductive sheath configured as an outer conductive sheath 922. Outer conductive sheath 922 is mounted circumferentially around and concentrically with inner conductive sheath 930 such that the inner and outer conductive sheaths form respective inner and outer electrodes of an electrode pair.

[0104] Conductive sheaths 930 and 922 are formed from a conductive material (e.g., a conductive metal) and are formed into an extended tubular or cylindrical shape. In some examples, the inner conductive sheath 930 and / or the outer conductive sheath 922 are formed from corrosion-resistant metal tubes, such as stainless steel, platinum, iridium, molybdenum, tungsten, or copper tubes. The inner conductive sheath 930 can be any desired thickness, such as 0.002 to 0.003 inches. The outer conductive sheath 922 can be relatively thicker than the inner conductive sheath. For example, the outer conductive sheath 922 can be approximately 0.004 to 0.006 inches thick. However, in other examples, the inner conductive sheath 930 is thicker than the outer conductive sheath 922. For example, the inner conductive sheath 930 can be 0.004 to 0.006 inches thick, and the outer conductive sheath 922 can be relatively thinner, such as 0.002 to 0.003 inches thick.

[0105] The inner conductive sheath 930 and the outer conductive sheath 922 each include a respective distal edge 931, 923. The distal edge 931 of the inner conductive sheath 930 is arranged proximate to the distal edge 923 of the outer conductive sheath 922 to provide an arcing region between the two sheaths through which current can flow to generate a shock wave within the catheter. The distal edge 931 of the inner conductive sheath 930 and the distal edge 923 of the outer conductive sheath 922 together form an electrode pair of the electrode assembly. As will be described in more detail below, the distal edge 931 of the inner conductive sheath 930 can be shaped so that a specific portion (e.g., portion 925) of the distal edge 931 is closer to the outer conductive sheath 922 than the rest of the distal edge (i.e., so as to provide a predetermined initial arcing region between the two conductive sheaths).

[0106] As in Figure 9B As shown in , the inner conductive sheath 930 and the outer conductive sheath 922 are separated by a cylindrical insulating layer 942 (e.g., an insulating sheath) that is mounted between the conductive sheaths 930 and 922 and concentric with the conductive sheaths 930 and 992. The insulating layer 942 is formed of a non-conductive insulating material that prevents unintended current flow between the inner surface of the outer conductive sheath 922 and the outer surface of the inner conductive sheath 930. In some examples, the insulating layer 942 is formed of a polymer material, such as polyimide, that is shaped into an extended tubular or cylindrical shape. In some examples, the insulating layer 942 is approximately 0.002 inches to 0.004 inches thick. As shown in Figure 1 As shown in FIG, the insulating layer 942 has a distal edge that is located adjacent to (e.g., flush with) the distal edges 931, 923 of the respective inner and outer conductive sheaths 930, 922. The proximal edge of the insulating layer extends beyond the proximal edge of at least one of the inner conductive sheath 930 and / or the outer conductive sheath 922 to prevent unintended current flow between the proximal edges of the conductive sheaths 930, 922. The shape and position of the insulating layer 942 ensure that the initial arcing region (i.e., the path of least resistance for current flow, typically the location where the sheaths are closest together) between the inner and outer conductive sheaths 930, 922 is located between the respective distal edges 931, 923, and more particularly, at the flush portion 925 of the inner conductive sheath 930.

[0107] In some examples, the distal edge 931 of the inner conductive sheath 930 is shaped to have multiple distinct regions that are closer to or farther from the paired distal edge 923 of the outer conductive sheath 922, i.e., to promote degradation in a predefined or semi-controlled manner. For example, the distal edge 931 of the inner conductive sheath 930 can be shaped such that a portion 925 of the distal edge 931 is closest to the distal edge 923 of the outer conductive sheath 922, i.e., to provide a predetermined initial arcing region for current flow between the conductive sheaths 930, 922. Second and further arcing regions can be provided by shaping additional portions of the distal edge 931 to be a second portion closer to the distal edge 923, and so on.

[0108] As in Figure 9BAs shown in FIG, the electrode shock wave source 960 also includes two insulated wires 966, 964 extending along the length of the catheter. More specifically, the first insulated wire 966 is electrically connected to the inner conductive sheath 930, and the second insulated wire 964 is electrically connected to the outer conductive sheath 922. The insulated wires 966, 964 provide an electrical connection between the conductive sheaths 930, 922 and an external voltage source, such as a high voltage pulse generator (not shown). In some examples, the inner conductive sheath 930 is connected to the positive terminal of the voltage source, and the outer conductive sheath 922 is connected to the negative terminal of the voltage source or to ground. However, the reverse connection is also contemplated (i.e., where the outer conductive sheath 922 is connected to the positive terminal and the inner conductive sheath is connected to the negative terminal or to ground). In some examples, the conductive portions of the wires 966, 964 are heat sealed or otherwise secured to the conductive sheaths 930, 922 to provide a direct electrical connection. Insulated wires 966, 964 can extend within the fluid lumen of the catheter, such as being fixed to the sidewall of the lumen or being disposed in a groove extending along the lumen. In other examples, wires 966, 964 extend through a separate lumen of the catheter, such as a wire lumen.

[0109] A series of high-voltage pulses can be delivered through wires 966 and 964 by an external voltage source (e.g., a pulsed high-voltage source) to generate a series of shock waves at the electrode shock wave source 960. The negative and positive terminals of the external voltage source are connected to the proximal ends of the first and second insulated wires 964, and when the high-voltage pulses are delivered through wires 966 and 964, a potential difference is generated between the inner conductive sheath 930 and the outer conductive sheath 922 (i.e., the electrode pair of the electrode assembly). This potential difference causes current to flow through the electrode pair to generate shock waves. The direction of current flow depends on the polarity of the electrodes, with current flowing from the electrode with a more positive charge (i.e., the electrode connected to the positive terminal of the voltage source) to the electrode with a more negative charge (i.e., the electrode connected to the negative terminal of the voltage source). The duration and amplitude of the voltage pulses are sufficient to generate bubbles and / or shock waves on the electrode surface (i.e., on the distal edges 931 and 923 of the conductive sheaths 930 and 922).

[0110] Figure 10A -B shows another electrode configuration, which shows the distal end of a catheter 1000 having a bellows-like portion 1080, a rigid tapered distal tip 1030, and a shock wave source 1060 comprising a flat wire emitter within a conductive sheath. Figure 10A The distal tip of catheter 1000 is depicted, and Figure 10B The distal tip of catheter 1000 is depicted as shock waves 1010 are generated via shock wave generator 1060 .

[0111] According to one embodiment, the catheter 1000 may include a centering mechanism, a deflector 1040, and a catheter body 1020 with a bellows 1080 as described above, wherein the shock wave source 1060 is configured to similarly generate shock waves that strike the back of the deflector 1040. Figure 10A As shown, the deflector 1040 is connected to the impactor 1030, which is located inside the catheter body 1020 and extends from the deflector 1040 to the rigid tip 1070 of the catheter 1000. As described above, the rigid tip 1070 can be tapered in various ways. The distal tip 1035 of the impactor 1030 is located near the rigid tip 1070 of the catheter 1000, rather than extending outwardly on the exterior of the catheter body 1020.

[0112] like Figure 10A As shown, when the shock wave source 1060 of the catheter 1000 is not generating shock waves, the bellows 1080 of the catheter can be in a folded, unstretched position. However, when the shock wave source 1060 generates shock waves, the bellows 1080 can flatten, thereby allowing the portion of the catheter 1000 located between the distal end 1024 of the catheter 1000 and the bellows 1080 to move forward. According to one embodiment, the portion of the catheter 1000 located forward of the bellows 1080 can be configured to vibrate in an axial direction (e.g., forward and backward) due to the shock wave impinging on the deflector 1040. As described above, in some embodiments, when the portion of the catheter body 1020 located between the bellows 1080 and the distal end 1024 moves, the portion of the catheter body 1020 located between the proximal end of the catheter 1000 and the bellows 1080 will remain stationary.

[0113] In one or more examples, the impactor 1030 can be configured to translate axially in response to shock waves generated by the shock wave generator 1060. The axial oscillation of the deflector 1040 can induce corresponding axial (i.e., forward and backward) oscillations in the attached impactor 1030, thereby creating a "jackhammer" effect that can penetrate occlusions in a body lumen. The distal tip 1035 of the impactor 1030 can vibrate in response to the repetitive shock waves from the shock wave source 1060, thereby further disrupting the occlusion. In some embodiments, the distal tip 1035 of the impactor 1030 and the portion of the catheter between the bellows 1080 and the distal end 1024 can vibrate in response to the repetitive shock waves from the shock wave source 1060. The "jackhammer" effect and / or vibrations of the distal tip 1035 and / or the vibrating portion of the catheter body can penetrate the fibrous cap of the CTO and modify calcified areas of the body lumen to restore flow within the body lumen. As described above, in addition to the "jackhammer" effect of the impactor 1030, at least a portion of the shockwave generated by the shockwave source 1060 can be deflected by the rear surface of the deflector 1040 in a lateral direction of the catheter 1000. Thus, the catheter 1000 can be configured to utilize the "jackhammer" effect of the impactor 1030 and / or the vibrating portion of the catheter body to break up occlusions near the distal tip 1035 of the impactor 1030, and to utilize laterally propagating shockwaves to break up occlusions near the body 1020 of the catheter 1000, as will be discussed further below.

[0114] According to one embodiment, the electrode pair of the flat coil may be formed by the flat coil placed within a conductive sheath, wherein the flat coil and the conductive sheath are each connected to an insulated wire. Figure 10C An exemplary flat coil transmitter shock wave source, such as shock wave source 1060 of catheter 1000, is shown. Shock wave source 1060 includes a flat helical wire configured as a flat coil 1020 and a cylindrical conductive sheath configured as a conductive sheath 1022, separated by an insulating sheath 1042. Insulating sheath 1042 is circumferentially mounted within conductive sheath 1022, with flat coil 1020 disposed on an inner surface of insulating sheath 1022 such that flat coil 1020 and conductive sheath 1022 form respective electrodes of an electrode pair.

[0115] The conductive sheath 1022 and the flat coil 1020 can be formed of a conductive material such as a conductive metal. In one or more examples, the conductive sheath 1022 can be formed of a corrosion-resistant metal tube, such as a stainless steel tube, a platinum tube, an iridium tube, a molybdenum tube, a tungsten tube, or a copper tube, which is shaped into an extended tubular or cylindrical shape. The flat coil 1020 can similarly be formed of a corrosion-resistant metal material such as stainless steel, platinum, iridium, molybdenum, tungsten, or copper, which is shaped into a flat spiral coil. The flat coil 1020 can have any desired thickness, for example, 0.002 inches to 0.003 inches thick. In one or more examples, the conductive sheath 1022 can be relatively thicker than the flat coil 1020. For example, the conductive sheath 1022 can be approximately 0.004 inches to 0.006 inches thick. Alternatively, the flat coil 1020 can be thicker than the conductive sheath 1022. For example, the flat coil 1020 may be 0.004 inches to 0.006 inches thick, while the conductive sheath 1022 may be relatively thin, such as 0.002 inches to 0.003 inches thick.

[0116] In some embodiments, the flat coil 1020 and the conductive sheath 1022 form an electrode pair for an electrode assembly of a catheter. Figure 10C As shown in FIG, a flat coil 1020 has a distal end 1021 and a conductive sheath has a distal edge 1023. The distal end 1021 of the flat coil 1020 is positioned proximate to the distal edge 1023 of the outer conductive sheath 1022 to create an arc region across which current can flow between the flat coil 1020 and the conductive sheath 1022. In one or more examples, the current flowing across the arc region can generate a shock wave within the catheter.

[0117] As in Figure 10C As shown in FIG, the flat coil 1020 and the conductive sheath 1022 are separated by an insulating sheath 1042. The insulating sheath 1042 can be formed of a non-conductive insulating material that prevents unintended current flow between certain areas of the flat coil 1020 and the conductive sheath 1022. In one or more examples, the insulating sheath 1042 can block any current flow between the flat coil 1020 and the conductive sheath 1022 along the length of the insulating sheath 1042. Because current is prevented from flowing between the flat coil 1020 and the conductive sheath 1022 along the length of the insulating sheath 1042, current can only flow across the arc region between the distal end 1023 of the conductive sheath 1022 and the distal end 1021 of the flat coil 1020. In one or more examples, the insulating sheath 1042 can be formed of a polymer material, such as polyimide, that is shaped into an extended tubular or cylindrical shape. In one or more examples, the insulating sheath 1042 can be approximately 0.002 inches to 0.004 inches thick.

[0118] As in Figure 10C, the insulating sheath 1042 has a distal edge 1041. In one or more examples, the distal edge 1041 of the insulating sheath 1042 can be adjacent to (e.g., flush with) the distal edge of the conductive sheath 1022 and / or the flat coil 1020. The proximal edge of the insulating sheath 1042 can extend beyond the proximal edge of at least one of the conductive sheath 1022 and the flat coil 1020 to prevent unintended current flow between the proximal edge of the conductive sheath 1022 and the flat coil 1020. The shape and position of the insulating sheath 1042 can ensure that an arcing region (e.g., a path of least resistance for current flow, typically the shortest distance between the flat coil and the sheath) between the flat coil 1020 and the conductive sheath 1022 is located between the distal end 1021 of the flat coil 1020 and the distal edge 1023 of the conductive sheath 1022. In one or more examples, the arc region will initially begin, more specifically, at the distal end 1021 of the flat coil 1020 at the very end of the coil.

[0119] As in Figure 10C As shown in , shock wave source 1060 may also include two insulated wires 1066 and 1064 extending along the length of the catheter. Specifically, first insulated wire 1066 may be electrically connected to flat coil 1020, and second insulated wire 1064 may be electrically connected to conductive sheath 1022. In one or more examples, insulated wires 1066 and 1064 may provide an electrical connection between flat coil 1020, conductive sheath 1022, and an external voltage source, such as a high-voltage pulse generator (not shown). In one or more examples, flat coil 1020 may be connected to the positive terminal of the voltage source, and conductive sheath 1022 may be connected to the negative terminal of the voltage source or ground. Alternatively, flat coil 1020 may be connected to the negative terminal of the voltage source or ground, while the conductive sheath is connected to the positive terminal of the voltage source. The conductive portions of wires 1066 and 1064 may be heat-sealed or otherwise secured to conductive sheath 1022 and flat coil 1020 to provide a direct electrical connection. In one or more examples, insulated wires 1066, 1064 can extend within a fluid lumen of the catheter, for example, by being secured to a sidewall of the lumen or disposed within a groove extending along the lumen. Wires 1066, 1064 can also extend through a separate lumen of the catheter, for example, a wire lumen. In one or more examples, wires 1066, 1064 can be insulated copper wires.

[0120] A series of high voltage pulses can be transmitted through wires 1066, 1064 by an external voltage source (e.g., a pulsed high voltage source) to generate a series of shock waves at shock wave source 1060. The negative and positive terminals of the external voltage source can be connected to the proximal ends of first insulated wire 1066 and second insulated wire 1064, so that when the high voltage pulses are transmitted through wires 1066, 1064, a potential difference is generated between flat coil 1020 and conductive sheath 1022 (i.e., the electrode pair of the electrode assembly). The potential difference can cause current to flow between the electrode pair to generate shock waves. In one or more examples, the direction of current flow can depend on the polarity of the electrodes, with current flowing from the electrode with more positive charge (i.e., the electrode connected to the positive terminal of the voltage source via one of wires 1066, 1064) to the electrode with more negative charge (i.e., the electrode connected to the negative terminal of the voltage source via one of wires 1066, 1064). The duration and amplitude of each voltage pulse is sufficient to generate bubbles on the electrode surface (ie, on the distal end 1021 of the flat coil 1020 and the distal edge 1023 of the conductive sheath 1022).

[0121] Figure 11A -B shows Figure 10A Catheter 1000 shown in FIG. 1B is used to treat a complete occlusion within a body lumen. As described above, when shock wave source 1060 of catheter 1000 generates shock waves that impinge on deflector 1040 , impactor 1030 can generate a "jackhammer" effect based on axial translation of distal tip 1035 of impactor 1030 . Figure 11A The catheter 1000 is depicted actively utilizing this jackhammer effect to effectively drill into the occluded region 1102 within the body lumen 1104. As the catheter 1000 is advanced further into the occlusion 1102, the laterally propagating shock wave (e.g., the shock wave deflected in a lateral direction after impacting the back side of the deflector 1040) helps to break up the occlusion 1102, as shown in FIG. Figure 11B As shown in the crack 1106 depicted in FIG. Figure 11A The catheter 1000 is shown creating a path into the occluded area 1102. Figure 11B The catheter 1000 is shown widening the passageway, which both enables the catheter 1000 to advance further into the occluded region 1102 and aids in fragmenting the occluded region 1102. Thus, the catheter 1000 can be configured to treat a body lumen region proximate the distal end 1024 of the catheter 1000 and proximate the catheter body 1020 using a forward jackhammer effect and transverse shock wave energy.

[0122] It should be noted that the elements and features of the exemplary catheters described above may be rearranged, recombined, and modified without departing from the present invention. For example, while a certain number of shock wave sources have been discussed above, catheters according to the present invention may be configured to generate shock waves using a variety of different electrode configurations, and the number, placement, and spacing of electrode pairs may be modified without departing from the present invention. Furthermore, while Figure 7 An example method is shown, but the steps of the method may be rearranged, reordered, removed, or modified without departing from the invention.

[0123] It should be understood that the foregoing is merely illustrative of the principles of the present invention, and that various modifications, variations, and combinations may 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 features described herein with any other catheter or combination of catheters. Furthermore, any method may be used with any of the disclosed catheters. Accordingly, the present invention is not intended to be limited, except as by the appended claims.

Claims

1. A catheter for treating an occlusion in a body lumen, the catheter comprising: a catheter body having a distal end, the catheter body being fluid-fillable; an impactor connected to the distal end of the catheter body, the impactor having a proximal end inside the catheter body and a distal end outside the catheter body; a shock wave source configured to generate a shock wave; and a deflector coupled to the proximal end of the impactor between the shock wave source and the distal end of the catheter body, wherein when the shock wave source generates a shock wave, the shock wave impinges on the deflector, thereby causing the deflector, along with the impactor, to be propelled distally relative to the catheter body, such that the distal end of the impactor delivers a mechanical force to the occlusion.

2. The catheter according to claim 1, wherein The distal end of the catheter body includes a flexible material that allows the impactor to be propelled forward in response to the generation of the shock wave and to return rearward after the shock wave has ceased.

3. The catheter according to claim 1, wherein The fluid is a conductive fluid, wherein the shock wave source comprises an electrode pair.

4. The catheter according to claim 3, further comprising: a first insulated wire extending along a length of the catheter, the first insulated wire having an exposed distal tip; and a second insulated wire extending along the length of the catheter, the second insulated wire having an exposed distal tip; a conductive transmitter strip mounted within the catheter and surrounding the exposed distal tips of the first and second insulated wires; as well as wherein when a voltage is applied across the first insulated wire and the second insulated wire, current is configured to flow from the exposed distal tip of the first insulated wire to the conductive transmitter tape to generate a first shock wave, and wherein current is also configured to flow from the conductive transmitter tape to the exposed distal tip of the second insulated wire to generate a second shock wave.

5. The catheter of claim 3, further comprising a voltage source configured to deliver a high voltage pulse to the shock wave source, wherein the high voltage pulse is in the range of 100V to 3000V. The catheter according to claim 5 , wherein: The voltage source is configured to deliver voltage pulses at a rate of 10 Hz to 100 Hz.

7. The catheter according to claim 1, wherein The deflector is configured to be able to advance 50 μm to 100 μm when the shock wave source generates a shock wave.

8. The catheter according to claim 1, wherein When the shock wave source generates a shock wave, the deflector deflects a portion of the shock wave energy in a direction transverse to the catheter.

9. The catheter according to claim 1, wherein A deflector angle between a rear surface of the deflector and a longitudinal axis of the catheter body is in the range of 120° to 150°.

10. The catheter of claim 1, further comprising: a cylindrical body mounted within the catheter body; and A shaft is mounted to a proximal end of the deflector, wherein the shaft is configured to slide within the cylindrical body.

11. The catheter according to claim 10, wherein The shaft includes a spacer that projects outwardly between the shaft and the cylindrical body to maintain the shaft approximately centered within the cylindrical body while allowing the shaft to move along a central axis of the catheter.

12. The catheter according to claim 1, wherein The shock wave source includes a laser that generates light pulses that are delivered to the catheter body via an optical fiber.

13. The catheter according to claim 1, wherein The impactor comprises a laser cut metal tube.

14. The catheter according to claim 13, wherein The impactor includes a guidewire lumen sized to receive a guidewire.

15. The catheter of claim 1, further comprising a tapered distal tip coupled to a distal end of the catheter body, wherein the tapered distal tip is configured to be advanced forwardly along with the deflector and the impactor to deliver a mechanical force to the occlusion.

16. The catheter according to claim 15, wherein The tapered distal tip comprises a rigid material.

17. The catheter of claim 1, wherein The catheter body includes a plurality of folds disposed thereon, the plurality of folds being configured to expand to a deployed position in response to the generation of a shock wave and to return to a collapsed position after the shock wave has ceased.

18. The catheter according to claim 17, wherein The catheter body includes a vibrating section located between the fold and the distal end of the catheter body and a stationary section located on the proximal end of the catheter body and terminating at the fold; wherein the vibrating section is configured to move in a forward direction when the fold expands toward the deployed position and to return backward when the fold returns toward the folded position.

19. The catheter of claim 1, wherein The shock wave source comprises: a cylindrical inner conductive sheath mounted within the catheter, the inner conductive sheath having a distal edge; a cylindrical outer conductive sheath positioned within the catheter, the outer conductive sheath mounted circumferentially around the inner conductive sheath, the outer conductive sheath having a distal edge adjacent a distal edge of the inner conductive sheath; and an insulating sheath mounted within the conduit between the outer conductive sheath and the inner conductive sheath; When a voltage pulse is applied to the inner conductive sheath and the outer conductive sheath, current flows across an arc region between the inner conductive sheath and the outer conductive sheath to generate a shock wave.

20. The catheter of claim 1, wherein The shock wave source comprises: a cylindrical conductive sheath mounted within the catheter, the conductive sheath having a distal edge; an insulating sheath mounted circumferentially within the conductive sheath, the insulating sheath having a distal edge adjacent a distal edge of the conductive sheath; a flat coil disposed on an inner surface of the insulating sheath and on a distal edge of the insulating sheath; and When a voltage pulse is applied to the flat coil and the conductive sheath, current flows in an arc region between the flat coil and the conductive sheath to generate a shock wave.

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