Lesion-crossing shockwave catheter

Abstract

The present invention provides a catheter for treating an occlusion in a body lumen. The catheter includes a catheter body that is fillable with a fluid. An impactor is connected to a distal end of the catheter body and has a proximal end inside the catheter body and a distal end outside the catheter body. The catheter also includes a shockwave source configured to generate shockwaves and a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body. When the shockwave source generates shockwaves, the shockwaves impact the deflector and advance the deflector along with the impactor in a forward direction such that the distal end of the impactor delivers a mechanical force to the occlusion and restores flow to the body lumen.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Application No. 63 / 252,467, filed October 5, 2021, and U.S. Provisional Application No. 63 / 349,995, filed June 7, 2022, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to the field of medical devices and methods, and more specifically to a catheter device for treating an obstruction in a body lumen, such as a blood vessel or urinary lumen. [Background technology]

[0003] The subject invention relates generally to catheters for treating an obstruction in a body lumen, such as a kidney stone, a calcified lesion in a vessel, a partial coronary artery obstruction, or a chronic total coronary artery obstruction, and restoring flow to the lumen.

[0004] Chronic total occlusions ("CTOs") in vascular arteries remain the "final frontier" for percutaneous intervention. When arteries become partially or completely blocked with thrombus, plaque, fibrous plaque, or calcium deposits, interventions to remove the blockage become much riskier for the patient and much more complicated and time-consuming for the physician. Left untreated, CTOs can reduce blood flow to the heart and peripheral limbs, causing severe ischemia and amputation.

[0005] In a typical CTO intervention, a physician first threads a soft, thin guidewire into the blood vessel, puncturing the occluded area and reaching the distal true lumen of the vessel. An angioplasty balloon can then be delivered over the guidewire down the vessel to the location of the blockage and pressurized to reduce or destroy the calcified plaque.

[0006] Although a wide variety of catheters have been developed to treat arterial disease, most commercial devices do not provide a high success rate for CTO treatment. Existing treatment systems for percutaneous coronary angioplasty or peripheral angioplasty, such as balloon catheters, are ill-suited to cross the resistant fibrotic and calcified tissue common in CTO. Conventional guidewires have difficulty penetrating the thick fibrous cap of CTO and can risk trauma to the vessel wall when navigating narrow and tortuous regions of the vessel. Attempts to penetrate a CTO using soft guidewires can cause buckling (e.g., deflection of the guidewire into subintimal passages or collateral branches), and stiffer guidewires must be used very carefully to avoid penetrating the arterial wall when pushed against a total occlusion. Even when initial puncture with a guidewire is successful, placement of an expansion device, such as angioplasty balloons, can be very difficult in chronically occluded vessels. This makes the treatment of CTO a technically challenging procedure that demands a long learning curve for the interventional cardiologist.

[0007] Recently, catheters have been developed that include one or more shock wave sources (e.g., electrode pairs) for generating shock waves inside an angioplasty balloon. Shock wave devices can be particularly effective for treating calcified lesions because the acoustic waves can break up the lesion in the vicinity of the angioplasty balloon without harming the surrounding vessels. In these devices, the catheter can be advanced over a guidewire within the patient's vasculature until it is proximal to the lesion. The balloon is then inflated with a conductive fluid, contacting the lesion, and a high voltage pulse is applied across the electrode pair, creating shock waves that direct acoustic waves into the lesion. Once the lesion has been broken up, the balloon can be expanded further within the vessel to create improved blood flow within the lumen. Efforts are being made to direct the acoustic energy from the shock waves in a forward direction to break up the tougher, more difficult to cross blockages within the vessel. Examples of forward firing designs can be found in U.S. Pat. No. 10,966,737 and U.S. Publication No. 2019 / 0388110, both of which are incorporated herein by reference.

[0008] Shockwave catheter designs have been deployed in both coronary and peripheral vascular applications, but even these designs have difficulty crossing chronic partial or total occlusions in the vessel.

[0009] Some currently available devices for treating CTOs use ultrasound, piezoelectric crystals, or linear acoustic shock wave sources to deliver mechanical energy to disrupt chronic occlusions. In many cases, these devices direct strong mechanical vibrations along a guidewire to perforate fibrotic and calcified tissue within the vessel. However, these systems require bulky and expensive generators to operate, and the intensity of the vibrations can make the guidewire difficult to control and risk damaging the vessel wall during treatment. Other systems use mechanical hammers that can be introduced over the guidewire to deliver mechanical energy to resistant CTOs. However, these systems also face similar problems. Still further systems direct radio frequency energy along the guidewire to disrupt the occlusion. However, radio frequency energy generates heat and plasma within the vessel, and the guidewire in such systems must be carefully centered and moved continuously to avoid burning the vessel wall.

[0010] In addition to these problems, many existing systems for treating CTOs require multiple devices to complete the intervention, e.g., one device to penetrate the occlusion and another device to modify the calcified tissue adjacent to the vessel wall. Thus, there is an unmet need for a device that can penetrate resistant fibrotic and calcified tissue to treat CTOs without expensive generators, multiple devices, and unnecessary risk of trauma to the vessel.

[0011] Similar devices are needed for blockages that form in other parts of the body, such as kidney stones in the ureter. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Pat. No. 10,966,737 [Patent Document 2] US Patent Application Publication No. 2019 / 0388110 Summary of the Invention [Means for solving the problem]

[0013] The above objects are realized in a catheter including an impactor for delivering a mechanical force directly to an occlusion in 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 a distal end of the catheter body and having a distal tip outside the catheter body. In other examples, the impactor is a flexible hollow member having a lumen for receiving the guidewire. The proximal end of the impactor is coupled to a deflector configured to slide forward and backward within the catheter body. When shock waves are generated within the catheter body, the shock waves impact the deflector, causing it to advance in a forward direction. The distal end of the impactor is driven into the occlusion with the deflector, delivering a mechanical force to the occlusion. The repeated shock waves cause the deflector and impactor to vibrate, creating a "jackhammer effect" that ruptures the occlusion and restores flow to the lumen.

[0014] An exemplary invention provides a catheter for treating an occlusion in a body lumen. The catheter includes a catheter body having a distal end, the catheter body being fillable with a fluid. The catheter also includes 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. The catheter also includes a shockwave source configured to generate shockwaves and a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body. When the shockwave source generates shockwaves, the shockwaves impact the deflector and propel the deflector forward with the impactor such that the distal end of the impactor delivers a mechanical force to the occlusion.

[0015] An exemplary method for treating an occlusion in 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 fillable 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 inside the catheter body and a distal end outside the catheter body. The catheter further includes a shockwave source configured to generate shockwaves within the catheter body and a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body. The method also includes advancing the catheter into the body lumen such that the distal end of the impactor is positioned proximate to the occlusion. The method also includes applying a high voltage pulse across the shockwave source to generate shockwaves. As the shockwave source generates the shockwaves, the shockwaves impact the deflector and advance in a forward direction with the impactor such that the distal end of the impactor delivers a mechanical force to the occlusion. [Brief description of the drawings]

[0016]

[0023] Illustrative aspects of the present disclosure are described in detail below with reference to the following drawing figures:

[0024] It is intended that the embodiments and figures disclosed herein be considered illustrative, not restrictive.

[0017] [Figure 1] FIG. 1 is an illustration of a catheter being used to treat a stenotic lesion in a blood vessel according to an aspect of the present disclosure.

[0018] [Diagram 2] FIG. 2 is an illustration of a distal end of a catheter for treating an occlusion in a body lumen in accordance with an aspect of the present disclosure.

[0019] [Diagram 3] FIG. 3 is an illustration of the distal end of the catheter of FIG. 2 generating a shock wave that impinges on a deflector in accordance with an aspect of the present disclosure.

[0020] [Figure 4A]FIG. 4A is an illustration of a catheter having a hollow, elongated impactor in accordance with an aspect of the present disclosure.

[0021] [Figure 4B] FIG. 4B is an illustration of the catheter of FIG. 4A with a removable guidewire inserted through the impactor in accordance with an aspect of the present disclosure.

[0022] [Figure 5A] FIG. 5A is an illustration of a distal end of a catheter having a tapered distal tip in accordance with an aspect of the present disclosure.

[0023] [Figure 5B] FIG. 5B is a rendering of a tapered distal tip having splines for penetrating an occlusion in accordance with an aspect of the present disclosure.

[0024] [Figure 5C] FIG. 5C is a rendering of a tapered distal tip having a smooth outer surface in accordance with an aspect of the present disclosure.

[0025] [Figure 6] FIG. 6 is an illustration of a catheter that generates shock waves to cause mechanical vibration of a guidewire in accordance with an aspect of the present disclosure.

[0026] [Figure 7] FIG. 7 is a flow chart of a method of using a catheter to treat an obstruction in a body lumen according to an aspect of the present disclosure.

[0027] [Figure 8] FIG. 8 is an illustration of a distal end of a catheter having a tapered distal tip and a bellows in accordance with an aspect of the present disclosure.

[0028] [Figure 9A] FIG. 9A is an illustration of a distal end of a catheter having a tapered distal tip and a coaxial emitter in accordance with an aspect of the present disclosure.

[0029] [Figure 9B] FIG. 9B illustrates an exemplary coaxial emitter shockwave source according to aspects of the present disclosure.

[0030] [Figure 10A] FIG. 10A is an illustration of a distal end of a catheter having a stiff tapered distal tip and a flat wire emitter in accordance with an aspect of the present disclosure.

[0031] [Figure 10B] FIG. 10B is an illustration of the distal end of the catheter of FIG. 10A generating a shock wave that impinges on a deflector in accordance with an aspect of the present disclosure.

[0032] [Figure 10C] FIG. 10C illustrates a coaxial emitter shockwave source according to an aspect of the present disclosure.

[0033] [Figure 11A] FIG. 11A is an illustration of the catheter of FIG. 10A being used to treat a total occlusion in a body lumen in accordance with an aspect of the present disclosure.

[0034] [Figure 11B] FIG. 11B is an illustration of the catheter of FIG. 10A being used to disrupt a total occlusion in a body lumen in accordance with an aspect of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The following description is presented to enable those skilled in the art to make and use the various embodiments disclosed herein. Descriptions of specific devices, techniques, and applications are provided only as examples. Various modifications of the examples described herein will be readily apparent to those skilled in the art, and the general principles described herein may be applied to other examples and applications without departing from the spirit and scope of the various embodiments. Thus, the various embodiments and aspects thereof are not intended to be limited to the examples described and shown herein, but are to be accorded the scope consistent with the claims.

[0036] The present disclosure generally relates to a catheter system for treating an obstruction in a body lumen, such as a CTO or circumferential calcium in a patient's vasculature or a kidney stone in a patient's ureter. The catheter described herein incorporates an impactor element that delivers mechanical force directly to the obstruction in the body lumen, allowing for the treatment of harder, more difficult to traverse calcified lesions and CTOs. The present invention is similar to existing intravascular lithotripsy systems in that it may include one or more shockwave sources (e.g., electrode pairs) on a catheter that is advanced into the patient's body lumen to treat the obstruction. However, the catheter of the present invention further includes an impactor (e.g., an impacting 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 inside the catheter body and a distal end outside the catheter body adapted to mechanically impact the obstruction. When shock waves are generated in the shockwave source inside the catheter body, at least a portion of the shockwave energy impacts the deflector and propels it forward with the impactor. As the deflector advances forward within the catheter body, the distal tip of the impactor advances forward within the body lumen, delivering a mechanical force directly to the occlusion. The distal end of the catheter body has flexible material properties that allow the impactor to advance forward in response to a shock wave. When the shock wave ends, the material properties of the distal end cause the impactor and deflector to return rearward to their original positions within the catheter body. In some examples, the deflector is coupled to a centering mechanism that maintains the deflector and impactor approximately at the central axis of the catheter body while allowing forward and rearward movement along the central axis.

[0037] Generating repeated shock waves causes the deflector to vibrate inside the catheter body. The deflector transfers mechanical energy to the impactor, causing vibrations at the impactor's distal tip, creating an oscillating "jackhammer effect" to clear the occlusion from the body lumen. Advantageously, incorporating an impactor element that delivers direct mechanical force to the occlusion allows the catheter to puncture and cross resistant and fibrotic areas within the body lumen, such as calcified and fibrotic tissue and CTOs, that are difficult to treat through traditional angioplasty methods. This allows the catheter to advance into and treat even tougher areas of the body lumen, such as those that are partially or completely occluded, restoring normal flow to the lumen.

[0038] In addition to impacting the deflector and causing vibrations in the impactor, at least a portion of the shockwave energy may be transmitted (e.g., propagated and / or deflected by the deflector) in a direction transverse to the catheter. This transverse shockwave energy propagates through the wall of the catheter body to treat areas of the body lumen proximal to the catheter body, such as calcified areas formed on the walls of the lumen. When combined with a jack hammer guided forward of the impactor, this transverse shockwave energy may enable the catheter to treat larger areas of the occluded vessel in succession (e.g., both the total occlusion distal to the catheter and the calcified tissue surrounding the catheter), reducing the need for multiple devices during treatment of the occluded body lumen. Once the total occlusion is disrupted (e.g., penetrated by the impactor to provide space for entry of the distal end of the catheter body), the catheter may be advanced further into the body lumen and shockwave therapy may be continued to reduce the calcified tissue surrounding the catheter.

[0039] FIG. 1 illustrates an exemplary catheter 10 for treating an occlusion in a body lumen. The catheter 10 can be introduced into an occlusion in a patient's vasculature, such as a stenotic lesion depicted in FIG. 1, using a removable guidewire 20 or an elongated impactor 18 connected to a distal end 14 of the catheter body 12. During treatment, the catheter body 12 is advanced within the lumen until the distal tip of the impactor 18 is adjacent to the occlusion and / or until the distal end 14 of the catheter body 12 is positioned proximate a calcified region of the lumen. In some examples, the catheter body 12 has compliant material properties such that the catheter can be twisted, curved, and physically manipulated to steer the catheter 10 to the site of the occlusion in 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 with a lumen sized to receive a guidewire (e.g., a removable guidewire 20)). The distal end 14 encloses a shockwave source 16 such that shockwaves are generated within a closed system defined by the walls of the catheter body 12. The shockwave source 16 generates shockwaves in a number of emitters (e.g., electrode pairs) causing acoustic waves to propagate through the distal end 14 of the catheter body 12. In some examples, the electrode pairs may be formed from one or more insulated wires having exposed portions (e.g., exposed distal tips or insulation removed portions of the wires) 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 may be arranged in a low-profile configuration that reduces the diameter of the distal end 14 of the catheter 10 and allows for treatment of stiffer, more difficult to traverse lesions, such as CTOs (i.e., stenotic lesions) depicted in Figure 1. In some examples, the electrode pairs may be formed from an outer conductive sheath mounted circumferentially around and concentric with an inner conductive sheath, each connected to an insulated wire mounted within the catheter body 12. Alternatively, the electrode pairs may be formed from a flat coil disposed within the conductive sheath, with both the flat coil and the conductive sheath 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 remains outside the patient's body lumen during treatment. The proximal end 22 includes a fluid port 26 for filling and emptying (e.g., inflating and deflating) the catheter body 14 with a conductive fluid. An electrical connection port 24 is also disposed on the proximal end 22 of the catheter 10 and provides an electrical connection between the shockwave source 16 and an external pulsed high voltage source 28, such as the generator shown in FIG. 1. In some examples, the proximal end 22 includes an entry port for receiving a removable guidewire 20 (e.g., an additional guidewire to aid in the insertion and advancement of the catheter into the body lumen in addition to the impactor 18 that impacts the occlusion).

[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., an end of the catheter body 12 that houses the shockwave 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 and provide a connection between a high voltage source 28 and one or more electrode pairs of the shockwave source 16. In some examples, at least a portion of the catheter body 12 includes an internal conduit that connects elements of the distal end 14 with the catheter's proximal end handle 22. For example, one or more wire lumens may be provided to carry insulated wires that electrically connect the pulsed high voltage source 28 with the electrodes of the distal shockwave source 16, and / or one or more fluid lumens (e.g., a fluid inlet lumen and a fluid outlet lumen) may be provided to carry a conductive fluid from the fluid port 26 to the distal end 14 of the catheter body 12. In some instances, such as those in which the catheter 10 is inserted using a removable guidewire, the catheter body 12 and / or the impactor 18 may include a guidewire lumen sized to receive the guidewire.

[0043] 2-3 illustrate an exemplary catheter for treating an occlusion in a body lumen, such as the catheter described in connection with FIG 1. FIG 2 provides a cross-sectional view of a distal portion of the catheter. FIG 3 provides a cross-sectional view of the distal portion of the catheter while the catheter is generating shock waves to treat an occlusion in a body lumen.

[0044] 2, the catheter 100 includes a catheter body 120, a flexible impactor 130, a deflector 140, a centering mechanism 150, and a shockwave source 160. The impactor 130 is sealed to the distal end 124 of the catheter body 120 with a seal 125 and includes a proximal end 132 inside the catheter body 120 and a distal end 134 that remains outside the catheter body 120, the distal end 134 having a distal tip 135 for impacting an occlusion in a body lumen. The deflector 140 is coupled to the proximal end 132 of the impactor 130 and is disposed between the shockwave source 160 and the distal end 124 of the catheter body 120 such that shockwaves generated by the shockwave source 160 impinge on a rear surface 144 of the deflector 140. The centering mechanism 150 is coupled to a proximal end of the deflector 140 and adapted to maintain the deflector 140 and the impactor 130 along the central axis of the catheter 100 while allowing oscillatory forward and backward movement of the deflector 140 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 shockwave sources 160, e.g., one or more electrode pairs, generate shockwaves within the catheter body 120 to advance the distal tip 135 of the impactor 130 into the occlusion. In some examples, as seen in FIGS. 2-3 , the shockwave source 160 includes a conductive emitter band 162 mounted within the catheter and one or more insulated wires (e.g., a first insulated wire 164 and a second insulated wire 166) extending along the length of the 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 a physician when the catheter 100 is in use, and the distal end 124 refers to the end of the catheter body 120 furthest from a physician who will be positioned proximate a treatment site within a body lumen, e.g., an area of ​​blockage or calcified plaque in a blood vessel or a kidney stone in a ureter, and who will control the catheter 100 from outside the lumen. In some examples, the proximal end of the catheter body 120 includes a handle of the catheter 100, e.g., the handle shown in FIG. 1.

[0046] The walls of the catheter body 120 surround the shockwave source 160 and define a cavity that can be filled with a conductive fluid, such as saline. The conductive fluid allows electrical current to flow across the electrodes of the shockwave source 160 and allows shockwaves to propagate from the shockwave source 160 to the deflector 140 and through the walls of the catheter body 120. In some embodiments, the conductive fluid may also include an X-ray contrast agent to allow fluoroscopic viewing of the catheter 100 during use. Fluid may be flowed in and out of the catheter body 120 via fluid inlet and fluid return lines (not shown), respectively. The fluid inlet line may include a fluid inlet positioned at the proximal end of the catheter body 120 that allows fluid to flow into the catheter body 120. The fluid return line may include a fluid inlet positioned near the distal end 124 of the catheter body 120 that draws the conductive fluid from the interior volume of the catheter body 120. Thus, the fluid inlet and return lines circulate a conductive fluid within the interior volume of the catheter body 120. The circulation of the conductive fluid may prevent air bubbles and debris generated by the shockwave source 160 from becoming trapped within the distal end 124 of the catheter body 120 due to the limited space within the tip. Additionally, the circulation of the conductive fluid may help cool the catheter 100 and the treatment site.

[0047] The distal end 124 of the catheter body 120 (e.g., at least the most distal 10 mm to 20 mm portion of the catheter body) is formed from a flexible material such as Pebax or polyurethane. The flexible material of the distal end 124 allows the impactor 130 to advance in a forward direction in response to the generation of a shock wave and causes the impactor 130 to move backwards after the shock wave has ended. The flexible material of the distal end 124 has compliant or semi-compliant material properties that allow the distal end 124 to expand or contract in response to axial movement of the deflector 140 and the impactor 130. In some embodiments, the distal end 124 of the catheter body 120 is molded with features, e.g., ridges or protruding features, that facilitate the expansion and contraction of the distal end 124 to allow advancement of the impactor 130 and to effect rearward movement of the impactor 130.

[0048] The catheter body 120 (e.g., the proximal end of the catheter body 120) may be formed from any desired material, for example, a low profile flexible or semi-compliant polymeric material such as Pebax or polyurethane. The distal end 124 may be integral to the catheter body 120 and formed from the same material, or may be formed from a different material and attached to the remainder of the catheter body 120 using, 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 from a stiff material and the distal end 124 of the catheter body is formed from a relatively more flexible material.

[0049] In some examples, at least a portion of the catheter body is formed from a flexible material that is expandable to increase the diameter of the catheter body 120, for example, to facilitate treatment of an area of ​​the body lumen proximate and surrounding the catheter body 120. For example, at least the distal end 124 of the catheter body 120 may be formed from an expandable material. In such examples, the catheter body 120 may be inflated with a conductive fluid such that, in an expanded state, the distal end 124 contacts the peripheral wall of the body lumen and provides a space between the shockwave source 160 and the wall of the catheter body. The catheter body 120 may be inflated to a desired pressure, which may be from about 1 atmosphere to about 6 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) may be about 10 to 15% greater than the diameter of the catheter body 120 in the deflated state. However, in some instances, the diameter of the catheter body 120 in the expanded state is less than 10% greater than the diameter of the catheter body 120 in the collapsed state, or has approximately equal diameters in both the collapsed and expanded states.

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

[0051] The distal end 124 of the catheter body 120 encloses the shockwave generator 160 such that shock waves are generated within a closed system defined by the walls of the distal end 124. Thus, the flexible material of the distal end 124 allows for the transmission of acoustic energy through the surface of the catheter body 120 and into a region of the body lumen located proximate to the surface of the catheter body 120. In some examples, the catheter body 120 and / or the distal end 124 are formed from a heat resistant material adapted to prevent accidental rupture of the material caused by heat generated by the shockwave source 160 during shockwave 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 with a seal 125, for example, laser bonding, heat sealing, or adhesive. In another example, the seal 125 is formed from a hole in the elastic material of the distal end 124 of the catheter body 120 having a smaller diameter than the elongated impactor 130, such that the hole compresses the circumference of the impactor 130 and holds the impactor 130 in connection with the distal end 124. In other examples, the hole may be sized to loosely hold the impactor 130 in connection with the distal end 124. Other means of connecting the distal end 124 and the impactor 130 are also envisioned.

[0053] As used herein, the impactor 130 is an elongated flexible shaft-like member adapted to impact an occlusion within a body lumen to deliver a mechanical force directly to the occlusion. In some examples, the impactor 130 is a metal guidewire or a portion of a guidewire. In other examples, the impactor 130 is a hollow tube-like member having a lumen created within a closed system and sized to receive a guidewire (e.g., the removable guidewire 20 of FIG. 1). The impactor 130 includes a proximal end 132 inside the catheter body 120 and a distal end 134 outside the catheter body 120 (e.g., outside the catheter body 120 but inside the body lumen) that includes a distal tip 135. The distal end 134 of the impactor 130 refers to the portion of the impactor 130 that is distal to the seal 125 between the impactor 130 and the distal end 124 of the catheter body 120, and the proximal end 132 of the impactor 130 refers to the portion that is proximal to the seal 125 between the deflector 130 and the distal end 124.

[0054] The proximal end 132 of the impactor 130 may terminate at the deflector 140. However, alternatively, the proximal end 132 may 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 still a further example, the proximal end 132 of the impactor 130 extends through the shaft of the catheter body 120, and in some cases to a proximal end handle of the catheter 100 outside the body lumen (e.g., a handle controlled by the physician during advancement and use of the catheter, such as handle 22 depicted in FIG. 1).

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

[0056] The flexible impactor 130 has material properties that facilitate 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 stiff to puncture a calcified lesion, such as a CTO capsule, when driven into the lesion by a shock wave. The material properties of the impactor 130 are also sufficiently compliant to advance through a lumen without damaging the soft tissue of the lumen wall (i.e., the material properties of the impactor 130 may allow the impactor 130 to twist, bend, and flex to navigate 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 stiffer material than the remainder of the impactor 130 (e.g., a stiffer material than the material of 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 piercing feature adapted to penetrate a thick fibrous capsule of an occlusion such as a CTO.

[0057] 2-3 illustrate the distal end of one exemplary catheter 100 and impactor 130, the exemplary catheter may be designed with additional or alternative impaction features near the distal end. For example, FIGS. 4A-4B illustrate another exemplary catheter 400, where the impactor 430 is a hollow, elongated, flexible member having a longitudinal channel (e.g., a guidewire lumen) for receiving a removable guidewire 490. FIG. 4A illustrates an exemplary catheter 400 having a hollow, elongated impactor 430, and FIG. 4B illustrates the catheter 400 with a removable guidewire 490 threaded through the impactor's guidewire lumen (e.g., to aid in the insertion and advancement of the catheter 400 and / or the removal of the catheter 400 and the insertion of a secondary device).

[0058] As shown in FIG. 4A, the impactor 430 may be an elongated hollow member that is bendable or removable so that the impactor 430 may navigate through curved and complex body lumens. The impactor 430 may include, for example, a laser-cut metal tube (e.g., laser-cut stainless steel or nitinol tube) or a solid metal tube, but may alternatively be formed from a compliant or semi-compliant polymer. A guidewire lumen extending through the impactor 430 is sized to receive a conventional guidewire. In such an example, the shaft 454 of the centering mechanism 450 (e.g., the centering mechanism 150 described with reference to FIGS. 2-3) may also include a channel (e.g., a guidewire lumen) sized to receive a guidewire. The centering mechanism 450 may also include an O-ring protruding outward between the shaft 454 and the cylinder 452 to prevent leakage of fluid from the catheter body 420 through the hollow guidewire lumen of the shaft 454 and the impactor 430.

[0059] As seen in Figures 5A-5C, the exemplary catheter 500 may also 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 impactor 530, i.e., deliver a mechanical force to the occlusion by advancing forward in response to the generation of a shock wave within the catheter body 520 and advancing backward due to the flexible material properties of the distal end 524 of the catheter body. Figure 5A shows the distal end of an exemplary catheter 500 including a tapered distal tip 570 coupled to the distal end of the catheter body. Figures 5B and 5C provide renderings of two examples of tapered distal tips 570 that may be included in an exemplary catheter design.

[0060] 5A-5C, the exemplary tapered distal tip 570 may have a substantially conical shape with an outer surface that tapers between the distal end 524 of the catheter body 520 and the impactor 530. The tapered distal tip 570 also includes a channel (e.g., impactor lumen) sized to fit the impactor 530, such that the impactor passes through and is connected to the distal tip 570. The tapered distal tip 570 may be formed from a relatively stiffer material than the flexible and / or expandable distal end of the catheter body 524. For example, the tapered distal tip 570 may be formed from a semi-compliant or stiff polymer. The tapered distal tip 570 may be coupled to the distal end of the catheter body 524 and / or the impactor 530 using, for example, laser bonding or heat sealing. 5A-5B, the tapered distal tip 570 may also include a piercing feature 572 to facilitate puncturing and crossing an occlusion within a body lumen, such as a tough capsule of a CTO. The piercing feature 572 may include, for example, a longitudinal spline (e.g., a ridge) extending along the outer surface of the tapered distal tip 570. The piercing feature 572 may allow the tapered distal tip 570 to impact an occlusion over a relatively smaller surface area, resulting in a relatively increased mechanical force against the occlusion as compared to a distal tip with a smooth outer surface. In another example, as seen in FIG. 5C, the outer surface of the tapered distal tip 570 may be smooth.

[0061] 2-3, the exemplary catheter 100 also includes a deflector 140 coupled to the proximal end 132 of the impactor 130. The deflector 140 is disposed between the shockwave source 160 and the distal end 124 of the catheter body 122 and includes a front surface 142 and a rear surface 144. As seen in FIG. 2-3, 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 impacts the rear surface 144 of the deflector 140, propelling the deflector 140 in a forward direction (i.e., toward the distal end 124 of the catheter body 120) along with the impactor 130. In some examples, when the shockwave source 160 generates a shockwave, the deflector 140 advances 50 μm to 100 μm. However, in other examples, the deflector 140 is configured to advance a greater or lesser distance in response to the generation of the shockwave, e.g., 100 μm to 200 μm, 200 μm to 500 μm, or less than 50 μm, or in distance increments and gradients within these ranges.

[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., projects outward from the impactor 130 and / or shaft 154). The deflector includes a distal front surface 142 facing toward the distal end 124 of the catheter body 120 and a proximal rear surface 144 facing toward the proximal end of the catheter body 120. The deflector 140 may be generally disk-shaped, as seen in FIGS. 2-3, or may have a generally cylindrical shape, with the front surface 142 and the rear surface 144 joined 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 drag caused by the forward advancement 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 less than the diameter of the catheter body 120 to provide a gap between the outer circumference 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 forward and backward within the catheter body 120).

[0063] FIG. 6 provides a perspective cross-sectional view of the distal end of an exemplary catheter 600 showing a deflector 640 deflecting a shock wave generated by a shock wave source 660 in the catheter body 620. As seen in FIG. 6, 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, perpendicular to the central axis of the catheter body 620. In such an example, the initial shock wave may be directed in a forward direction, while the deflected shock wave may be deflected in a direction transverse to the catheter 600. The deflected shock wave energy may propagate through the conductive fluid and through the wall of the distal end 624 of the catheter body 620 to deliver acoustic energy to treat calcified regions of the body lumen surrounding the catheter body 620.

[0064] The proportion of shockwave energy directed to either end (i.e., the amount of shockwave energy propelling the deflector 640 in a forward direction compared to the amount of shockwave energy deflected in a transverse direction relative to the catheter body 620) can be determined by the deflector angle 646 between the deflector 640 and the impactor 630. As shown in FIG. 6, the deflector angle 646 is the angle between the longitudinal axis of the catheter 600 (which may be understood as the central longitudinal axis passing through the axial center of the catheter body 620, the proximal end 632 of the impactor 630, or 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 may be selected to provide a desired magnitude of treatment through either 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 may be selected to provide a first desired percentage of shockwave energy directed toward advancing the impactor 630 (i.e., forward shockwave energy) and a second desired percentage of shockwave energy directed in a direction laterally relative to the catheter body 620 (i.e., lateral shockwave energy). For example, an embodiment with a 90 degree deflector angle 646 (i.e., the rear surface 644 of the deflector 640 protrudes at an angle of 90 degrees relative to the longitudinal axis of the catheter body 620) will result in the maximum amount of shockwave energy being directed toward advancing the impactor 630 (i.e., the maximum amount of forwardly directed shockwave energy with little or no energy directed laterally). An embodiment with a deflector angle 646 of about 135 degrees (i.e., the rear surface 644 of the deflector 640 projects at an obtuse 135 degree angle relative to the longitudinal axis of the catheter body 620) may result in the greatest amount of shockwave energy being directed laterally relative to the catheter (i.e., the greatest amount of lateral shockwave energy). In some examples, the deflector angle 646 between the deflector 640 and the impactor 630 is between 90 degrees and 180 degrees, or at an angle increment or gradient within this range.In a further example, the deflector angle 646 between the deflector 640 and the impactor 630 is between 120 degrees and 150 degrees. In yet a further example, the deflector angle 646 between the deflector 640 and the impactor 630 is about 135 degrees.

[0065] The deflector 640 may be formed from any desired material, but is more preferably formed from a material that reflects acoustic sound waves. For example, the deflector 640 may include a rigid material, such as a rigid and / or heat resistant polymeric 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 may be formed from a different material, for example, laser bonded or heat sealed to the impactor 630 and / or the shaft 654.

[0066] 2-3, in 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 approximately axially centered (i.e., along the longitudinal axis of the catheter) of the catheter body 120 while allowing forward and rearward axial movement of the deflector 140. The centering mechanism 150 may be formed of a cylinder 152 mounted within the catheter body and a shaft 154 mounted at the proximal end of the deflector 140, the shaft 154 being configured to slide within the cylinder 152. When the shockwave source 160 generates shockwaves, the shaft 154 slides forward within the cylinder 152 along with the deflector 140 and the impactor 130. The shaft 154 optionally includes a spacer 156 that protrudes outward between the shaft 154 and the wall of the cylinder 152 to hold the shaft 154 approximately axially centered in the cylinder 152 while allowing forward and rearward movement of the shaft 154 along the central axis of the catheter body 120.

[0067] The cylinder 152 may be mounted within the catheter body 120 at any desired location. For example, as seen in FIGS. 2-3, the cylinder 152 may be mounted proximal to the deflector 140 along approximately the central axis of the catheter body 120. However, in other examples, the cylinder 152 may be mounted distal to the deflector 140, or in other words, mounted within the catheter body 120 between the deflector 140 and the distal end 124. In some examples, the cylinder 152 is mounted at 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 may be mounted between one or more insulated wires (e.g., the first insulated wire 164 and the second insulated wire 166) and, optionally, coupled to one or more of the insulated wires. In some examples, the catheter body 120 includes one or more lumens extending along the length of the catheter body 120, and the centering mechanism 150 includes a shaft 152 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. At that point, the length of the impactor 130 may pass through the deflector 140 and provide a shaft 154 that slides within the cylinder 152. In other examples, the shaft 154 may be coupled to the deflector 140 via, for example, laser bonding, heat sealing, adhesive, or some other attachment. In some examples, as seen in FIGS. 2-3, 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., is coupled to the front surface 142 of the deflector 140 or includes a portion of the impactor 130 extending 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 may be sized to slide loosely within the cylinder. For example, the shaft 154 may have a diameter approximately equal to or slightly less than the diameter of the cylinder 152, thereby providing a gap between the shaft 154 and the cylinder 152 through which fluid may flow while the shaft 154 advances forward and backward within the cylinder 152. Additionally or alternatively, the shaft 154 includes a spacer 156 that protrudes outward between the shaft 154 and the wall of the cylinder 152. The spacer 156 is adapted to hold the shaft 154 approximately centered within the cylinder 152 while allowing movement of the shaft 154 along the central axis of the catheter body 120. In some examples, the spacer 156 protrudes outward from the shaft 154 in a ring shape or a flattened cylindrical shape. In some examples, the spacer 156 includes holes or cutouts that allow fluid to flow around the spacer 156 as the spacer 156 and shaft 152 advance forward and backward within the cylinder 152, or in other words, when shock waves are generated, vibrating the deflector 140, shaft 154, and spacer 154 within the catheter body 120. The cutouts may 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 shockwave source 160 configured to generate shockwaves in the conductive fluid inside the catheter body 120. The distal end 124 of the catheter body 120 encloses the shockwave source 160 such that shockwaves generated by the shockwave source 160 propagate through the wall of the catheter body 120 to treat a region of the body lumen proximate the distal end 124. The shockwave source 160 is positioned proximal to the rear surface 144 of the deflector 140 such that when the shockwave source 160 generates shockwaves, at least a portion of the shockwave energy impacts the deflector 140.

[0071] As seen in FIG. 3, the repeated shock waves cause the deflector 140 to oscillate forward and backward within the catheter body. The axial vibration of the deflector induces corresponding axial (i.e., forward and backward) vibration in the attached impactor 130, creating a "jackhammer" effect that may penetrate the occlusion within the body lumen. The distal tip 135 of the impactor 130, which remains outside the catheter body 120, vibrates in response to the repeated shock waves at the shockwave source 160, further disrupting the occlusion. The combination of the "jackhammer" effect and the vibration of the distal tip 135 of the impactor 130 may penetrate the fibrous capsule of the CTO, remediate the calcified region of the body lumen, and restore flow to the body lumen.

[0072] In some examples, the shockwave source 160 generates shock waves at a frequency of 10 Hz to 100 Hz (i.e., the shock waves are generated at a repetition rate of 10 Hz to 100 Hz) and vibrates the deflector 140 at a frequency of about 10 Hz to 100 Hz. In such examples, the impactor 130 may vibrate or "jackhammer" at a frequency of 10 Hz to 100 Hz in response to the shock waves. However, the shockwaves may be generated at a higher or lower repetition rate depending, for example, on the size of the lesion, the extent of calcification, the size of the vessel, the patient's demographics, or the stage of treatment.

[0073] As used herein, the shockwave source 160 includes one or more electrode pairs, each electrode pair including a first electrode and a second electrode separated by a gap. Shockwaves can be generated in the shockwave source 160 by applying a high voltage pulse across the first and second electrodes of the pair. Each pulse initially ionizes the conductive fluid within the catheter body 120 proximate to the electrode. At some point, a plasma arc forms across the gap between the electrode pair, creating a low impedance path through which electrical current can flow freely. Thermal energy from the plasma arc heats the conductive fluid, creating a rapidly expanding vapor bubble. The expansion of the vapor bubble creates an acoustic shock wave that propagates through the conductive fluid inside the catheter body 120.

[0074] The electrode pair can be formed from the side edges of a conductive emitter band (e.g., a conductive sheath or ring electrode) and a conductive portion of the 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 insulating layer of the insulated wire near the distal end of the wire to expose the conductive portion of the wire. The location, size, and shape of the removed portion can be varied to control the location, direction, and / or magnitude 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 may be arranged in a low-profile configuration that reduces the diameter of the distal end 124 of the catheter body 120 and allows treatment of tighter, more difficult to cross lesions such as CTO. In some examples, the shockwave source 160 includes one or more coplanar electrode pairs, or one or more electrodes at least partially surrounded by a conductive emitter band. In some embodiments, flat wires, rather than round wires, are used to further reduce the cross-sectional profile of the electrode assembly.

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

[0077] More recently, the assignee has developed several coplanar electrode assemblies for use in catheters. Various 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 (incorporated herein by reference). These designs provide novel configurations of electrode pairs, for example, with helical structures and tongue-and-groove designs, with each electrode on the same lateral plane limiting the overall thickness of the electrode assembly. These assemblies are particularly advantageous for generating shock waves in tight, difficult-to-pass lesions or totally occluded vessels. For example, in U.S. Patent No. 9,993,292 and U.S. Publication No. 2018 / 0098779 (incorporated herein by reference), the assignee discloses forming electrode pairs from helically wound wires to generate shock waves at various gaps positioned circumferentially around a tubular structure. In U.S. Pat. No. 10,555,744 (also incorporated herein by reference), the present assignee discloses a tongue-and-groove electrode assembly in which an electrode pair is formed from a groove-shaped cutout in a conductive sheath and a coplanar tongue-shaped protrusion extending into the groove-shaped cutout.

[0078] 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 emitter band 162 mounted within the catheter 100. Each of the first and second insulated wires 164, 166 may be an insulated wire, and the conductive metal may be copper, aluminum, stainless steel, molybdenum, tungsten, or a combination thereof. Each of the first and second insulated wires 164, 166 includes an uninsulated conductive portion, such as an exposed distal tip of the wire, that functions as a first electrode of an electrode pair.

[0079] The conductive emitter band 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 emitter band is mounted within the interior volume of the catheter body 120 and surrounds the ends of the two insulated wires 164, 166 without touching the wires. The conductive emitter band 162 can be a conductive cylinder, for example a metal cylinder including stainless steel, tungsten, platinum, iridium, or alloys thereof. In some examples, the emitter band 162 is mounted within the catheter body 120 at a location distal to the exposed distal tips of the first and second insulated wires 164, 166 to drive the momentum of the shock wave to propagate in a substantially 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 an example, as depicted in Figures 2-3, the shockwave source 160 includes two electrode pairs, each respective pair of electrodes formed from conductive portions of insulated wires 164, 166, and a conductive emitter band 162 mounted within the catheter body 120. More specifically, the shockwave source 160 includes a first electrode pair, which may include a first electrode formed from an exposed distal tip of the first insulated wire 164, and a second electrode formed from the conductive emitter band 162. The shockwave source 160 further includes a second electrode pair, which may include a first electrode formed from an exposed distal tip of the second insulated wire 166, and a second electrode formed from the conductive emitter band 162.

[0081] The catheter 100 also includes a voltage source (e.g., the generator 28 depicted in FIG. 1) configured to deliver a high voltage pulse across the shockwave source 160. When the high voltage pulse is applied across the first insulated wire 164 and the second insulated wire 166, current is configured to flow from the exposed distal tip of the first insulated wire 164 to the conductive emitter band 162 and generate a first shockwave across the first electrode pair. Current is further configured to flow from the conductive emitter band 162 to the exposed distal tip of the second insulated wire 166 and generate a second shockwave across the second electrode pair. In some examples, the voltage source is configured to deliver a high voltage pulse at a voltage between 100V and 3,000V, or more specifically, between 2,300V and 3,000V. In further implementations, the voltage source can be configured to deliver high voltage pulses at voltages between 100V and 10,000V, and in voltage increments or gradients within that range. Additionally, the voltage source can be configured to deliver high voltage pulses at a desired repetition rate, for example, at a rate between 10Hz and 100Hz. However, the voltage source can be configured to deliver voltage pulses across the shockwave source 160 at any desired voltage and repetition rate. In some examples, the voltage source can be controlled by the physician during the treatment to deliver higher or lower voltage pulses, or voltage pulses at higher or lower repetition rates, as desired. For example, the physician can start with low energy shock waves and increase the energy as needed during the treatment. Alternatively, the physician can start with high energy shock waves, for example, to rupture the fibrous CTO capsule with the impactor 130, and decrease the energy as needed during the remainder of the treatment. The magnitude of the shock waves can be modified by controlling the voltage, current, duration, and repetition rate of the pulse voltage from the pulse voltage source. Further information about the physics of shock wave generation and their control can be found in US Pat. 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 emitter band 162 and the exposed distal tips of the insulated wires 164, 166. The insulating sheath may be mounted concentrically with and within the conductive emitter band 162 and adapted to prevent accidental current flow and leakage between the electrodes within the catheter body 120 (e.g., between the conductive portions of the insulated wires 164, 166 and the conductive emitter band 162). The insulating sheath includes holes located between the electrodes of each electrode pair such that the insulating sheath provides a path for current to flow between the conductive emitter band 162 and the conductive portions of the insulated wires 164, 166, the path may flow through the holes in the insulating sheath.

[0083] The placement and spacing of the electrode pairs (e.g., conductive emitter band 162 and insulated wires 164, 166) can be controlled to provide more effective shockwave therapy. For example, the electrode pairs of the shockwave source 160 can be spaced circumferentially inside the distal end 124 of the catheter body 120 in consistent increments, e.g., 180 degrees or 90 degrees apart, to generate shockwaves more uniformly around the catheter 100. For example, while the catheter shown in FIGS. 2-3 includes a first insulated wire 164 and a second insulated wire 166, the catheter 100 can have three or more wires and be configured to generate shockwaves with three or more pairs of electrodes. In certain examples, the catheter can 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 positioned at 0 and 180 degrees, the third and fourth insulated wires can be positioned at 90 and 270 degrees. The third and fourth insulated wires also terminate near the distal end of the catheter body and include conductive exposed distal tips that function as electrodes. A conductive emitter band (e.g., conductive emitter band 162 or additional emitter bands) surrounds the exposed distal tips of the third and fourth insulated wires, and a separate high voltage pulse can be applied across the third and fourth insulated wires to generate a second pair of shock waves between the insulated wires and the emitter bands. As a result, a second set of shock waves can be initiated from the third and fourth electrode pairs of the catheter formed from the conductive emitter bands and the conductive portions of the third and fourth insulated wires. The first pair of insulated wires (i.e., first insulated wire 164 and second insulated wire 166) and the second pair of insulated wires (i.e., third insulated wire and fourth insulated wire) may be alternately activated, which may improve the effectiveness of the device by further spreading the shock waves around the circumference of the catheter.

[0084] In some embodiments, the shockwave source 160 includes electrode pairs positioned in various longitudinally spaced groups inside the catheter body 120. For example, to generate shockwaves at a more intermediate location within the catheter body 120, i.e., to advantageously treat a larger area of ​​the body lumen surrounding the catheter body 120, the catheter 100 may include one or more intermediate shockwave sources. A distal shockwave source (e.g., shockwave source 160) may be configured to generate shockwaves to advance the deflector 140 and impactor 130 to treat an occlusion distal to the catheter body 120 (with a portion of the shockwave energy also directed laterally relative to the catheter 100 to treat an area of ​​the body lumen surrounding the distal end 124 of the catheter body 120), while an intermediate shockwave source may be configured to generate shockwaves to treat an area of ​​the body lumen surrounding an intermediate portion of the catheter body 120. In some examples, the catheter 100 includes a secondary conductive emitter band mounted at an intermediate location of the catheter body 120 (e.g., at a location proximal to the conductive emitter band 162) and an associated pair of insulated wires (e.g., the third and fourth insulated wires described above) spaced from the secondary emitter band, which form respective first and second intermediate electrode pairs for generating shock waves. When a high voltage pulse is applied across the third and fourth insulated wires, current is configured to flow from the exposed distal tip of the third insulated wire to the secondary conductive emitter band and across the first intermediate electrode pair to generate a first intermediate shock wave. Current is further configured to flow from the secondary conductive emitter band to the exposed distal tip of the fourth insulated wire and across the second electrode intermediate pair to generate a second intermediate shock wave.

[0085] Any number of conductive emitter bands may 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 bands spaced along the length of the catheter body 120 and associated pairs of insulated wires spaced from each band, which form respective electrode pairs for generating shock waves. In some examples, secondary or additional emitter bands may generate shock waves independently from the emitter bands at the distal end of the device.

[0086] All of the shockwave sources discussed above include an electrode pair and a high voltage source to generate electrical hydraulic shockwaves across the gap between the electrodes. It is within the scope of the subject invention to utilize other types of shockwave sources. For example, it is well known that focused laser light can generate shockwaves in a fluid. The laser light can be delivered from an external laser device into the catheter body via an optical fiber. The optical fiber can run along the catheter in a lumen similar to wire 164 or 166. In operation, a pulse of high energy laser light is launched into the proximal end of the optical fiber and delivered out the distal end of the fiber. The distal end of the fiber will be located in the area behind the deflector 140. The pulse will vaporize the fluid and generate a shockwave that will impact on the surface 144 of the deflector 140. In use, a pulse of laser light will be generated, generating a series of shockwaves that will vibrate the guidewire and jackhammer the occlusion. Lasers with high saline or water absorption coefficients are of particular interest because they generate more effective shock waves. A high absorption coefficient corresponds to a shallow absorption depth, and therefore the laser energy is limited to a small depth in the liquid, thus heating and vaporizing it very rapidly. Examples of preferred lasers include Ho:YAG (2,120 nm), Tm:YAG (2,010 nm), Tm fiber laser (1,940 nm), and Er:YAG (2,940 nm).

[0087] 7 is a flowchart representation of an exemplary method 700 for treating an obstruction in a body lumen, such as a kidney stone in a patient's ureter or a CTO or circumferential calcium in a patient's blood vessel. As depicted in FIG. 7, a catheter is introduced (702) into a patient's body lumen, such as a blood vessel in the patient's vascular system or a ureter in the patient's urinary system. The catheter may be any of the catheters described herein with reference to FIG. 1-3, 4A-4B, 5A-5C, 6, 8, 9A, or 10A. More specifically, the catheter includes at least a catheter body having a distal end, the catheter body being fillable with a conductive fluid, 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 shockwave source configured to generate shockwaves, and a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body.

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

[0089] The catheter is then advanced within the body lumen (704) such that the distal end of the impactor is positioned proximate to the occlusion within the body lumen. In some instances, as seen in FIG. 1, the catheter may be advanced until the distal end of the impactor is adjacent to the occlusion or until it is at least partially inside the occlusion. Additionally or alternatively, the catheter may be advanced until the distal end of the catheter body is positioned proximate to a calcified region of the lumen (i.e., to deliver shockwave therapy through the wall of the catheter body). If the catheter was advanced over the removable guidewire, the physician may optionally remove the guidewire. However, in other instances, the physician may retain the removable guidewire inside the catheter during treatment (e.g., retain the guidewire inside 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 contrast), such that the fluid covers the shockwave 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 proximate to the occlusion and the catheter body is filled with the conductive fluid, a series of shockwaves can be generated inside the catheter body (706). The series of shockwaves impact the deflector, causing it to advance in a forward direction with the impactor, such that the distal end of the impactor delivers a mechanical force for each generated shockwave to the occlusion. In some examples, the shockwave source includes one or more electrode pairs, and generating the series of shockwaves includes applying a high voltage pulse across the one or more electrode pairs. In another example, the shockwave source is a laser, and generating the series of shockwaves includes using the laser to deliver a high energy pulse of laser light. During 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 back to their original positions within the catheter body. As explained above, the repeated shock waves cause the impactor to shuttle and oscillate to penetrate and clear the occlusion and restore flow to the body lumen.

[0091] Repeated advancement of the catheter through the target region of the body lumen and repeated application of shock wave cycles can clear even tight, chronically occluded regions of the body lumen. For example, in some examples, the method further includes advancing the catheter further within the body lumen such that the distal tip of the impactor is proximate to an additional treatment region, e.g., a more distal occluded area of ​​a CTO or a more distal region of a calcified or partially occluded vessel. The method may then include generating an additional series of shock waves. As described above with reference to Figures 5A-5C, in some examples, the catheter includes a tapered distal tip configured to advance with the impactor and deflector in response to the generation of the shock waves. The tapered distal tip can be used to deliver mechanical forces to portions of the occlusion closer to the catheter body (i.e., in a more proximal region of the lumen compared to the distal tip of the impactor) to continue to penetrate and clear the occlusion. In such an example, the method may include advancing (708) the catheter further within the body lumen such that the tapered distal tip is positioned proximate a treatment area, such as a treatment area previously penetrated by the impactor. The method may then include generating (710) an additional series of shock waves to advance the tapered distal tip into the occlusion.

[0092] In one or more examples, after generating 708 an additional series of shock waves to advance the tapered distal tip into the occlusion, the method 700 may advance 710 the catheter further within the body lumen again such that the tapered distal tip is proximate the further target region before again generating 710 an additional series of shock waves. That is, in one or more examples, after step 710, the method 700 may repeat step 708 and then step 710 in a loop. Optionally, this loop of repeating steps 708 and 710 may be repeated multiple times.

[0093] To eliminate the need for multiple devices during treatment of an occlusion, the same catheter may be used to modify calcification and partial occlusion regions proximate the catheter body by delivering acoustic shockwave energy (e.g., transverse shockwaves) through the wall of the catheter body. For example, after modifying a fully or partially occluded region of the lumen using impacts from the distal tip of the impactor, the method 700 may further include advancing the catheter further within the body lumen (712) such that the catheter body is positioned proximate to a laterally located treatment region (e.g., an occlusion or some other calcification or partial occlusion region previously penetrated by the impactor). After advancing the catheter further within the body lumen, the method may include generating laterally directed shockwaves (714) to deliver acoustic shockwave energy to the laterally located occlusion. The transverse shockwave energy may propagate through the wall of the catheter body to treat a region of the body lumen proximal to the catheter body. In one or more examples, advancing the catheter such that the body of the catheter is proximate a laterally located treatment region in step 712 may also cause the distal tip to be proximate an additional treatment region. In such a case, when generating laterally directed shock waves in step 714, in addition to transmitting shockwave energy in a direction laterally relative to the catheter, at least a portion of the shockwave energy may be transmitted to create vibrations that advance the distal end of the impactor.

[0094] In one or more examples, after generating the laterally directed shockwaves in step 714, the method 700 may advance the catheter further within the body lumen (714) such that the body of the catheter is again proximate the laterally located treatment region before again generating (714) laterally directed shockwaves. That is, in one or more examples, after step 714, the method 700 may repeat step 712 and then step 714 in a loop. Optionally, this loop of repeating steps 712 and 714 may be repeated multiple times.

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

[0096] If the catheter includes two or more shockwave generators (e.g., distal and intermediate electrode pairs), a first treatment phase may include generating shockwaves at the first (e.g., distal) electrode pair and a second treatment phase may include generating shockwaves at the second (e.g., proximal) electrode pair. In the first phase of treatment, only the distal electrode pair may generate shockwaves, causing the impactor to advance forward and deliver a mechanical force to the occlusion within the body lumen. After the occlusion is corrected (e.g., the tough CTO capsule is 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 shockwaves.

[0097] In other examples, the catheter may be removed from the body lumen and replaced with a secondary device to continue treatment. The secondary device may be inserted and advanced over a guidewire (e.g., a removable guidewire or an additional guidewire as described above) into the target region of the body lumen.

[0098] Figure 8 illustrates an exemplary catheter 800 with a bellows 880 for treating an occlusion in a body lumen, such as the catheter described in connection with Figure 1. Similar to the catheter described above and shown in Figure 8, catheter 800 includes a deflector 840, a centering mechanism 850, a catheter body 820, a flexible impactor 830, and a shockwave source 860, which may be configured as discussed above.

[0099] As shown in FIG. 8, the catheter 800 includes a bellows 880 disposed on the wall of the catheter body 820. In some embodiments, the bellows 880 can be formed from a bellows-like portion of the wall of the catheter body 820 that provides an axial cushion that allows a forward 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 allow the catheter body 820 to stretch to a stretched position by flattening the bellows 880 and return to an unstretched position in which the bellows 880 is positioned in a folded manner. 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 as the bellows 880 is stretched. In some embodiments, the portion of the catheter body 820 located between the proximal end of the catheter 800 and the bellows 880 will remain stationary while the portion of the catheter body 820 located between the bellows 880 and the distal end 824 moves. In some embodiments, the bellows 880 can be formed from a flexible or semi-compliant material that allows the folds in the bellows 880 to stretch and flatten as discussed above.

[0100] The shockwave source 860 of the catheter 800 can be configured as the shockwave sources discussed above. For example, the shockwave source 860 can be configured to generate shockwaves in a conductive fluid inside the catheter body 820 that propagate through the walls of the catheter body 820 to treat an area of ​​the body lumen proximate the distal end 824 of the catheter 800. As discussed above, the repeated generation of shockwaves by the shockwave source 860 can cause the deflector 840 to oscillate forward and backward within the catheter body 820. Additionally, the axial oscillation of the deflector 840 can cause corresponding axial (i.e., forward and backward) oscillations in the attached impactor 830, creating a "jackhammer" effect that can penetrate an occlusion in the body lumen. The distal tip 835 of the impactor 830 can oscillate in response to the repeated shockwaves from the shockwave source 860 to further disrupt the occlusion. In some embodiments, both 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 repeated shock waves from the shock wave source 860. The "jack hammer" effect and / or vibration of the distal tip 835 and / or the vibrating portion of the catheter 800 can penetrate the fibrous capsule of the CTO, remediate the calcified region of the body lumen, and restore flow to the body lumen.

[0101] The shockwave source 860 includes one or more electrode pairs, each of which can include a first electrode and a second electrode separated by a gap. As discussed above and shown in FIG. 8, the electrode pairs of the shockwave source 860 are formed from the side edges of a conductive emitter band (e.g., a conductive sheath or ring electrode) and a conductive portion of a wire.

[0102] Alternative electrode configurations are suitable for use in catheters according to the invention. For example, catheter 900 depicted in Fig. 9A relies on a shockwave source 960 with a coaxial emitter. Catheter 900 can otherwise be configured similarly to catheter 800 discussed above. The coaxial emitter of shockwave source 960 can be formed of an outer conductive sheath mounted circumferentially concentrically around an inner conductive sheath, each connected to an insulated wire.

[0103] An exemplary coaxial emitter shockwave source, such as shockwave source 960 of catheter 900, is shown in FIG. 9B. Shockwave 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. The outer conductive sheath 922 is mounted circumferentially around and concentric with the inner conductive sheath 930, with the inner and outer conductive sheaths forming respective inner and outer electrodes of an electrode pair.

[0104] The conductive sheaths 930, 922 are formed from a conductive material, such as a conductive metal formed into a stretched tubular or cylindrical shape. In some examples, the inner conductive sheath 930 and / or the outer conductive sheath 922 are formed from erosion resistant metal tubing, such as stainless steel, platinum, iridium, molybdenum, tungsten, or copper tubing. The inner conductive sheath 930 can be of any desired thickness, for example, 0.002-0.003 inches thick. The outer conductive sheath 922 can be relatively thicker than the inner conductive sheath. For example, the outer conductive sheath 922 can be about 0.004-0.006 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 may be 0.004 to 0.006 inches thick and the outer conductive sheath 922 may be relatively thinner, for example, 0.002 to 0.003 inches thick.

[0105] Each of the inner conductive sheath 930 and the outer conductive sheath 922 includes a respective distal edge 931, 923. The distal edge 931 of the inner conductive sheath 930 is positioned proximate to the distal edge 923 of the outer conductive sheath 922 to provide an arcing region between the sheaths across which current may flow to generate shock waves inside 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 may be shaped such that a particular portion of the distal edge 931 (e.g., portion 925) is closer to the outer conductive sheath 922 than the remainder of the distal edge (i.e., to provide a predetermined initial arcing region between the conductive sheaths).

[0106] As seen in FIG. 9B, the inner conductive sheath 930 and the outer conductive sheath 922 are separated by a cylindrical insulating layer 942, e.g., an insulating sheath, mounted between and concentric with the conductive sheaths 930, 922. The insulating layer 942 is formed from 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 from a polymeric material, e.g., polyimide, molded into a stretched tubular or cylindrical shape. In some examples, the insulating layer 942 is about 0.002 to 0.004 inches thick. As seen in FIG. 1, the insulating layer 942 has a distal edge that is 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 ensures that the initial arcing region (i.e., the path of least resistance for current flow, which is usually the location of the closest distance between the sheaths) between the inner conductive sheath 930 and the outer conductive sheath 922 is between the respective distal edges 931, 923, and more specifically, at the coplanar 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 various regions that are closer or farther from the mating distal edge 923 of the outer conductive sheath 922, i.e., shaped to promote efficiency drop-off in a predetermined or semi-controlled manner. For example, the distal edge 931 of the inner conductive sheath 930 may 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 may be provided by shaping additional portions of the distal edge 931 second closest to the distal edge 923, and so on.

[0108] As shown in FIG. 9B, the electrode shockwave 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 depicted). 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 ground. However, the reverse connection is also envisioned (i.e., the outer conductive sheath 922 is connected to the positive terminal and the inner conductive sheath is connected to the negative terminal or 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. The insulated wires 966, 964 may extend into the fluid lumen of the catheter (e.g., may be secured to a sidewall of the lumen or may be disposed in a groove extending along the lumen). In other examples, the wires 966, 964 extend through a separate lumen of the catheter, e.g., a wire lumen.

[0109] A series of high voltage pulses can be delivered across the wires 966, 964 by an external voltage source, e.g., a pulsed high voltage source, to generate a series of shock waves in 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, 964, and when a high voltage pulse is delivered across the wires 966, 964, it creates a potential difference across the inner conductive sheath 930 and the outer conductive sheath 922 (i.e., the electrode pair of the electrode assembly). The potential difference causes current to flow through the electrode pair, generating shock waves. The direction of current flow depends on the polarity of the electrodes, with current flowing from the more positively charged electrode (i.e., the electrode connected to the positive terminal of the voltage source) to the more negatively charged electrode (i.e., the electrode connected to the negative terminal of the voltage source). The duration and magnitude of the voltage pulse is sufficient to generate gas bubbles and / or shock waves on the surface of the electrodes (ie, on the distal edges 931, 923 of the conductive sheaths 930, 922).

[0110] Another electrode configuration is shown in Figures 10A-B, which illustrate the distal end of a catheter 1000 having a bellows 1080, a stiff tapered distal tip 1030, and a shockwave source 1060 comprising a flat wire emitter within a conductive sheath. Specifically, Figure 10A depicts the distal tip of the catheter 1000, while Figure 10B depicts the distal tip of the catheter 1000 during generation of shockwaves 1010 via the shockwave generator 1060.

[0111] According to an embodiment, the catheter 1000 includes a centering mechanism as discussed above, a deflector 1040, and a catheter body 1020 with a bellows 1080, and the shockwave source 1060 can be configured to generate shockwaves that impact the rear side of the deflector 1040 as well. As shown in FIG. 10A, the deflector 1040 is disposed inside the catheter body 1020 and connected to an impactor 1030 that extends from the deflector 1040 to a stiff tip 1070 of the catheter 1000. The stiff tip 1070 can be tapered in various manners as discussed above. Rather than extending outward on the exterior of the catheter body 1020, the distal tip 1035 of the impactor 1030 is disposed proximate to the stiff tip 1070 of the catheter 1000.

[0112] As shown in FIG. 10A, when the shockwave source 1060 of the catheter 1000 is not generating shock waves, the bellows 1080 of the catheter may be in a folded, unstretched position. However, when the shockwave source 1060 is generating shock waves, the bellows 1080 may 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 in a forward direction. According to an embodiment, this portion of the catheter 1000 located in front of the bellows 1080 may be configured to oscillate axially (e.g., forward and backward) as a result of the shockwaves impinging on the deflector 1040. As discussed above, in some embodiments, the portion of the catheter body 1020 located between the proximal end of the catheter 1000 and the bellows 1080 will remain stationary while the portion of the catheter body 1020 located between the bellows 1080 and the distal end 1024 moves.

[0113] In one or more examples, the impactor 1030 can be configured to translate axially in response to shock waves generated via the shock wave generator 1060. Axial vibration of the deflector 1040 can cause corresponding axial (i.e., forward and backward) vibration in the attached impactor 1030, creating a "jackhammer" effect that can penetrate an occlusion in a body lumen. The distal tip 1035 of the impactor 1030 can vibrate in response to repeated shock waves from the shock wave source 1060 to further disrupt the occlusion. In some embodiments, both 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 repeated shock waves from the shock wave source 1060. The "jack hammer" effect and / or vibration of the distal tip 1035 and / or the vibrating portion of the catheter body can penetrate the fibrous capsule of the CTO, remediate the calcified region of the body lumen, and restore flow to the body lumen. In addition to the "jack hammer" effect of the impactor 1030, as discussed above, at least a portion of the shock waves generated via the shock wave source 1060 can be deflected in a direction that is transverse to the catheter 1000 by the rear surface of the deflector 1040. Thus, the catheter 1000 can be configured to utilize both the "jack hammer" effect of the impactor 1030 and / or the vibrating portion of the catheter body to disrupt occlusions proximate the distal tip 1035 of the impactor 1030, and laterally propagated shock waves to disrupt occlusions proximate the body 1020 of the catheter 1000, as will be discussed further below.

[0114] According to an embodiment, a flat wire coil electrode pair can be formed from a flat coil disposed within a conductive sheath, both of which are each connected to an insulated wire. An exemplary flat coil emitter shock wave source, such as a shock wave source 1060 of a catheter 1000, is shown in FIG. 10C. The shock wave source 1060 includes a flat spiral wire configured as a flat coil 1020 and a cylindrical conductive sheath configured as a conductive sheath 1022, separated by an insulating sheath 1042. The insulating sheath 1042 is mounted circumferentially within the conductive sheath 1022, and the flat coil 1020 is disposed on the inner surface of the insulating sheath 1022, whereby the flat coil 1020 and the conductive sheath 1022 form respective electrodes of the electrode pair.

[0115] The conductive sheath 1022 and the flat coil 1020 can be formed from a conductive material, such as a conductive metal. In one or more examples, the conductive sheath 1022 can be formed from an erosion-resistant metal tubing, such as stainless steel, platinum, iridium, molybdenum, tungsten, or copper tubing formed into a stretched tubular or cylindrical shape. The flat coil 1020 can similarly be formed from an erosion-resistant metal material, such as stainless steel, platinum, iridium, molybdenum, tungsten, or copper tubing formed into a flat helical coil. The flat coil 1020 can be of any desired thickness, for example, 0.002 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 about 0.004 to 0.006 inches thick. Alternatively, the flat coil 1020 can be thicker than the conductive sheath 1022. For example, the flat coil 1020 can be 0.004-0.006 inches thick, while the conductive sheath 1022 can be relatively thinner, for example, 0.002-0.003 inches thick.

[0116] In some embodiments, the flat coil 1020 and the conductive sheath 1022 form an electrode pair of an electrode assembly for the catheter. As shown in FIG. 10C, the flat coil 1020 has a distal end 1021 and the 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, creating an arcing region where current can flow between the flat coil 1020 and the conductive sheath 1022. In one or more examples, the current flowing across this arcing region can generate shock waves inside the catheter.

[0117] 10C, the flat coil 1020 and the conductive sheath 1022 are separated by an insulator sheath 1042. The insulator sheath 1042 can be formed from a non-conductive insulating material that prevents unintended current flow between a region of the flat coil 1020 and the conductive sheath 1022. In one or more examples, the insulator sheath 1042 can block any flow of current between the flat coil 1020 and the conductive sheath 1022 along the length of the insulator sheath 1042. Because current is prevented from flowing between the flat coil 1020 and the conductive sheath 1022 along the length of the insulator sheath 1042, current can only flow across the arcing 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 insulator sheath 1042 can be formed from a polymeric material, such as polyimide, molded into a stretched tubular or cylindrical shape. In one or more examples, the insulator sheath 1042 can be approximately 0.002 to 0.004 inches thick.

[0118] 10C, the insulator sheath 1042 has a distal edge 1041. In one or more examples, the distal edge 1041 of the insulator sheath 1042 can be proximate to (e.g., flush with) the distal edge of the conductive sheath 1022 and / or the flat coil 1020. The proximal edge of the insulator 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 edges of the conductive sheath 1022 and the flat coil 1020. The shape and position of the insulating sheath 1042 can ensure that the arcing region (e.g., the path of least resistance for current flow, which is usually the closest distance between the flat coil and the sheath) between the flat coil 1020 and the conductive sheath 1022 is 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 arcing region will more specifically begin first at the distal end 1021 of the flat coil 1020, which is located at the very end of the coil.

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

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

[0121] 11A-B illustrate the catheter 1000 of FIGS. 10A-B being used to treat a total occlusion in a body lumen. As discussed above, when the shockwave source 1060 of the catheter 1000 generates a shockwave that impacts the deflector 1040, the impactor 1030 can generate a "jackhammer" effect based on the axial translation of the distal tip 1035 of the impactor 1030. FIG. 11A illustrates the catheter 1000 actively utilizing this jackhammer effect to effectively perforate into an occluded area 1102 in a body lumen 1104. As the catheter 1000 advances further forward into the occlusion 1102, the laterally propagated shockwave (e.g., the shockwave that is laterally deflected after impacting the rear side of the deflector 1040) helps to shatter the occlusion 1102, as shown by the crack 1106 depicted in FIG. 11B. 11A shows the catheter 1000 creating a channel into the occluded area 1102, and FIG. 11B shows the catheter 1000 enlarging that channel both allowing the catheter 1000 to advance further into the occluded area 1102 and facilitating disruption of the occluded area 1102. Thus, the catheter 1000 can be configured to utilize both forward directed jackhammer and lateral shockwave energy to treat regions of the body lumen both proximal to the distal end 1024 of the catheter 1000 and adjacent to the catheter body 1020.

[0122] It should be noted that the elements and features of the exemplary catheters discussed above may be rearranged, recombined, and modified without departing from the present invention. For example, while several shockwave sources are discussed above, catheters according to the present invention may be configured to use various electrode configurations for generating shockwaves, and the number, placement, and spacing of electrode pairs may be modified without departing from the subject invention. Additionally, while FIG. 7 illustrates one exemplary method, steps of the method may be rearranged, reordered, removed, or modified without departing from the subject invention.

[0123] It should be understood that the foregoing is merely illustrative of the principles of the present invention, and that various modifications, alterations, and combinations may be made by those skilled in the art without departing from the scope and spirit of the present invention. Any of the various catheter variations disclosed herein may include features described with any other catheter or combination of catheters herein. Furthermore, any of the methods may be used in conjunction with any of the catheters disclosed. Thus, the present invention is not intended to be limited, except as by the appended claims.

Claims

1. 1. A catheter for treating an obstruction 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 shock waves; a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body; Equipped with When the shockwave source generates a shockwave, the shockwave impacts the deflector, causing the deflector to advance forward with the impactor such that the distal end of the impactor delivers a mechanical force to the occlusion.

2. 10. The catheter of claim 1, wherein the distal end of the catheter body comprises a flexible material that allows the impactor to advance in a forward direction in response to the generation of a shock wave and causes the impactor to return rearward after the shock wave has terminated.

3. The catheter of claim 1 , wherein the fluid is a conductive fluid and the shock wave source includes an electrode pair.

4. a first insulated wire extending along a length of the catheter, the first insulated wire having an exposed distal tip; a second insulated wire extending along the length of the catheter, the second insulated wire having an exposed distal tip; a conductive emitter band mounted within the catheter and surrounding the exposed distal tips of the first and second insulated wires; Furthermore, 4. The catheter of claim 3, wherein when a voltage is applied across the first insulated wire and the second insulated wire, current flows from the exposed distal tip of the first insulated wire to the conductive emitter band, generating a first shock wave, and the current flows from the conductive emitter band to the exposed distal tip of the second insulated wire, generating a second shock wave.

5. The catheter of claim 1 , wherein the deflector is configured to advance 50 μm to 100 μm when the shock wave source generates a shock wave.

6. The catheter of claim 1 , wherein when the shockwave source generates shockwaves, the deflector deflects a portion of the shockwave energy in a direction transverse to the catheter.

7. The catheter of claim 1, wherein the deflector angle between the rear surface of the deflector and the longitudinal axis of the catheter body is between 120° and 150°.

8. a cylinder mounted within the catheter body; a shaft mounted on the proximal end of the deflector; Furthermore, The catheter of claim 1 , wherein the shaft is configured to slide within the cylinder.

9. 9. The catheter of claim 8, wherein the shaft includes a spacer that protrudes outward between the shaft and the cylinder to hold the shaft approximately centered in the cylinder while allowing movement of the shaft along a central axis of the catheter.

10. The catheter of claim 3, further comprising a voltage source configured to deliver a high voltage pulse to the shock wave source, the high voltage pulse being between 100V and 3,000V.

11. The catheter of claim 10, wherein the voltage source is configured to deliver the voltage pulses at a rate of between 10 Hz and 100 Hz.

12. The catheter of 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 of claim 1 , wherein the impactor comprises a laser-cut metal tube.

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

15. 10. The catheter of claim 1, further comprising a tapered distal tip coupled to the distal end of the catheter body, the tapered distal tip configured to advance in a forward direction with the deflector and the impactor to deliver a mechanical force to the occlusion.

16. The catheter of claim 15 , wherein the tapered distal tip comprises a stiff material.

17. 10. The catheter of claim 1, wherein the catheter body comprises a plurality of folds disposed thereon, the plurality of folds configured to expand to an unfolded position in response to the generation of a shock wave and to return to a folded position after the shock wave has terminated.

18. 18. The catheter of claim 17, wherein the catheter body comprises a vibrating section between the fold and the distal end of the catheter body, and a stationary section located on the proximal end of the catheter body that terminates at the fold, the vibrating section configured to move in a forward direction as the fold expands to the unfolded position and to move backward as the fold returns to the folded position.

19. The shock wave source is a cylindrical inner conductive sheath mounted within the catheter, the inner conductive sheath having a distal edge; a cylindrical outer conductive sheath mounted circumferentially within the catheter around the inner conductive sheath, the outer conductive sheath having a distal edge proximal to the distal edge of the inner conductive sheath; an insulating sheath mounted within the catheter between the outer conductive sheath and the inner conductive sheath; Equipped with 10. The catheter of claim 1, wherein when a voltage pulse is applied across the inner and outer conductive sheaths, current flows across an arc discharge region between the inner and outer conductive sheaths, generating a shock wave.

20. The shock wave source is a cylindrical conductive sheath mounted within the catheter, the conductive sheath having a distal edge; an insulating sheath circumferentially mounted within the conductive sheath, the insulating sheath having a distal edge proximal to the distal edge of the conductive sheath; a flat coil disposed on the inner surface of the insulating sheath and on the distal edge of the insulating sheath; Equipped with 10. The catheter of claim 1, wherein when a voltage pulse is applied across the flat coil and the conductive sheath, current flows in an arc discharge region between the flat coil and the conductive sheath, generating a shock wave.

21. 1. A catheter for treating an obstruction 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 shock waves within the catheter body; a deflector coupled to the proximal end of the impactor between the shockwave source and the distal end of the catheter body; Equipped with the catheter is configured to be introduced into a body lumen of a patient and advanced within the body lumen such that the distal end of the impactor is positioned adjacent to the occlusion; The shock wave source is configured to generate a series of shock waves that impact the deflector, and to advance the deflector along with the impactor in a forward direction such that the distal end of the impactor delivers a mechanical force associated with each generated shock wave to the occlusion.

22. The catheter is configured to be advanced further within the body lumen so that the distal end of the impactor is positioned proximate to an additional treatment area; 22. The catheter of claim 21, wherein the shockwave source is configured to generate an additional series of shockwaves.

23. the catheter comprising a tapered distal tip coupled to the distal end of the catheter body; the catheter is configured to be advanced further within the body lumen so that the tapered distal tip is positioned proximate a treatment area; 22. The catheter of claim 21, wherein the shockwave source is configured to generate an additional series of shockwaves.

24. The catheter is configured to be advanced further within the body lumen so that the distal end of the catheter body is positioned proximate to a treatment area; 22. The catheter of claim 21, wherein the shockwave source is configured to generate an additional series of shockwaves.

25. 22. The catheter of claim 21, wherein the body lumen is a blood vessel in a patient's vascular system or a ureter in a patient's urinary system.

26. 22. The catheter of claim 21, wherein the occlusion comprises a chronic total occlusion (CTO), circumferential calcium, or a kidney stone.

27. 22. The catheter of claim 21, wherein the fluid is a conductive fluid, the shockwave source includes an electrode pair, and the catheter further comprises a voltage source configured to apply a high voltage pulse across the electrode pair.

28. 22. The catheter of claim 21, wherein the shock wave source comprises a laser, the laser being used to deliver high-energy pulses of laser light.

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