Optical assembly for improving energy coupling to a pressure wave generator of an intravascular lithotripsy device - Patent Application 2007023333

Abstract

A catheter system 100 for treating a treatment site 106 in or adjacent a vascular wall 108 or a heart valve includes an inflatable balloon 104, an optical fiber 122, and an energy source 124. The optical fiber 122 has a fiber proximal end 122P and a fiber distal end 122D disposed within the inflatable balloon 104. The optical fiber 122 is configured to receive an energy pulse such that the optical fiber 122 emits optical energy away from the optical fiber 122 to generate a plasma pulse within the inflatable balloon 104. The optical fiber 122 may be tapered from the fiber proximal end 122P to the fiber distal end 122D. The energy source 124 is in optical communication with the fiber proximal end 122P of the optical fiber 122 and may include a laser. The optical fiber 122 includes a first fiber member 250 and a second fiber member 258 coupled to the first fiber member 250. The first fiber member 250 may be fused to the second fiber member 258 at a fused region 256. The first fiber member 250 and the second fiber member 258 may be formed as a unitary structure. The catheter system 100 may also include a ferrule 248 that surrounds the fused region 256.

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Application No. 63 / 148,133, filed February 10, 2021, and U.S. Patent Application No. 17 / 666,172, filed February 7, 2022. To the extent permitted, the contents of U.S. Provisional Application No. 63 / 148,133 and U.S. Patent Application No. 17 / 666,172 are incorporated herein by reference in their entireties. [Background technology]

[0002] Vascular lesions in and adjacent to blood vessels throughout the body can be associated with an increased risk of major adverse events such as myocardial infarction, embolism, deep vein thrombosis, stroke, etc. Significant vascular lesions can be difficult for physicians in clinical practice to treat and achieve patency.

[0003] Vascular lesions can be treated using interventions such as medical therapy, balloon angioplasty, atherectomy, stent placement, vascular tissue graft bypass, to name a few, although such interventions may not always be ideal in some cases, or ongoing treatment may be required to address the lesion.

[0004] Creating high pressure impulses at the lesion using fiber optic delivery of laser pulses is one method attempted to treat the lesion. Creation of plasma via optical breakdown of an aqueous solution typically requires a significant amount of energy for a short period of time during which the energy is converted into therapeutic bubbles and / or therapeutic pressure waves. Summary of the Invention

[0005] The present invention is directed to a catheter system for treating a treatment site in or adjacent a blood vessel wall or a heart valve. The catheter system includes an inflatable balloon, an optical fiber, and an energy source. In certain embodiments, the optical fiber has (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, the optical fiber being tapered from the fiber proximal end to the fiber distal end. The energy source can be in optical communication with the fiber proximal end of the optical fiber.

[0006] In various embodiments, the optical fiber may be tapered using a fusion splicer.

[0007] In certain embodiments, the optical fibers may be spliced ​​using core matched fiber.

[0008] In some embodiments, the optical fiber can be split into a first fiber member and a second fiber member.

[0009] In various embodiments, the optical fiber can be split so that only the second fiber member can be positioned within the inflatable balloon.

[0010] In certain embodiments, the second fiber member can include a plurality of second fiber legs.

[0011] In some embodiments, the second fiber member can include two second fiber legs.

[0012] In various embodiments, the second fiber member can include three second fiber legs.

[0013] In certain embodiments, the first fiber member may be fused to the second fiber member at a fused region.

[0014] In some embodiments, the first fiber member and the second fiber member are formed as a unitary structure.

[0015] In various embodiments, the first fiber member and the second fiber member are integrally formed with one another.

[0016] In certain embodiments, the first fiber member and the second fiber member are formed continuously as a single structure.

[0017] In some embodiments, the first fiber member can have a first fiber member distal region that is exterior to the inflatable balloon.

[0018] In various embodiments, the second fiber member can have a second fiber member proximal region that is exterior to the inflatable balloon.

[0019] In certain embodiments, a first fiber member distal region can be fused to a second fiber member proximal region at a fused region.

[0020] In some embodiments, the energy source may include a laser.

[0021] In various embodiments, the catheter system can include a ferrule surrounding the fused region.

[0022] In certain embodiments, the catheter system can include a ferrule surrounding a first fiber proximal end of the first optical fiber and a first fiber distal end of the second fiber.

[0023] In some embodiments, the catheter system can include a plurality of ferrules surrounding a portion of the first fiber member and the second fiber member.

[0024] In various embodiments, the ferrule may comprise an LC ferrule with an outer diameter of 1.25 mm.

[0025] In a particular embodiment, the ferrule may comprise an SC ferrule with an outer diameter of 2.5 mm.

[0026] In some embodiments, the ferrule may be formed from one of a plastic and a metal.

[0027] In various embodiments, the ferrule may be configured for only one optical fiber.

[0028] In certain embodiments, the ferrule may be configured for multiple fiber members.

[0029] In some embodiments, the ferrule may be one of a multi-fiber MT ferrule and an MTP ferrule.

[0030] In various embodiments, the optical fiber can be cleaved at the first tapered portion of the first fiber piece.

[0031] In a specific embodiment, the optical fiber can be cleaved by one of a laser cleaver and a mechanical cleaver.

[0032] In some embodiments, the first fiber member can have a cleaved first portion that can be split again along a cleavage plane to form a curved ball surface.

[0033] In various embodiments, the optical fiber can be spin-tapered.

[0034] In certain embodiments, the optical fiber can be tapered without rotation.

[0035] In some embodiments, the ferrule may include at least one of a tapered fiber, a spliced ​​joint, and a bare fiber.

[0036] In various embodiments, at least one of the tapered fiber, the spliced ​​joint, and the bare fiber is surrounded inside the ferrule with epoxy.

[0037] In a specific embodiment, the epoxy may be ND353 enclosed for fiber connector polishing.

[0038] In some embodiments, the epoxy may be LOCTITE® 4310 UV adhesive.

[0039] In various embodiments, the optical fiber can be tapered from a diameter of 200 μm to a diameter of 105 μm.

[0040] In certain embodiments, the optical fiber can be configured to split optical energy traveling through a first fiber member into a second fiber member.

[0041] In some embodiments, the first fiber member can include an end cap.

[0042] In various embodiments, the ferrule substantially surrounds the first fiber member.

[0043] In certain embodiments, the optical fiber can be tapered such that it has a larger diameter at the fiber proximal end and a smaller diameter at the fiber distal end.

[0044] The present invention is also directed to a method for manufacturing a catheter system.

[0045] The present invention is further directed to a method for treating a treatment site in or adjacent a blood vessel wall or heart valve, the method including the steps of positioning an optical fiber having (i) a fiber proximal end and (ii) a fiber distal end disposed within an inflatable balloon, the optical fiber configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, and coupling an energy source to the fiber proximal end of the optical fiber, the energy source being coupled in optical communication with the optical fiber.

[0046] In some embodiments, the method may include tapering the optical fiber using a fusion splicer.

[0047] In various embodiments, the method may include splicing the optical fibers using a core-aligned fiber.

[0048] In certain embodiments, the method may include using a ferrule to surround the fused region.

[0049] In some embodiments, the method can include encircling a first fiber distal end of the first fiber member and a second fiber proximal end of the second fiber member using a ferrule.

[0050] In various embodiments, the method can include surrounding a portion of the first fiber member and the second fiber member using a plurality of ferrules.

[0051] The present invention is also directed to a catheter system including an inflatable balloon, an optical fiber, an energy source, and a fused region. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can include a first fiber member and a second fiber member. The energy source can be in optical communication with the fiber proximal end of the optical fiber. A fused region can be disposed where the first fiber member is fused to the second fiber member.

[0052] The present invention is further directed to a catheter system including an inflatable balloon, an optical fiber, an energy source, and a fused region. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can have a first fiber member and a second fiber member including a plurality of second fiber member legs. The energy source can be in optical communication with the fiber proximal end of the optical fiber. A fused region can be disposed where the first fiber member is fused to the second fiber member. The fused region can be configured to split optical energy traveling through the first fiber member into the second fiber member such that the optical energy is split among the plurality of second fiber member legs.

[0053] The present invention is also directed to a catheter system including an inflatable balloon, an optical fiber, an energy source, a fused region, and a capillary. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can have a first fiber member and a second fiber member including a plurality of second fiber member legs. The energy source can be in optical communication with the fiber proximal end of the optical fiber. A fused region can be disposed where the first fiber member is fused to the second fiber member. The fused region can be configured to split optical energy traveling through the first fiber member into the second fiber member such that the optical energy is split among the plurality of second fiber member legs. The capillary can substantially surround the fused region.

[0054] The present invention is further directed to a catheter system including an inflatable balloon, an optical fiber, a fused region, and a ferrule. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits light energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can include an end cap and a first fiber distal end disposed within the inflatable balloon. The optical fiber can have a first fiber member and a second fiber member. A fused region can be disposed where the first fiber member is fused to the second fiber member. The ferrule can substantially surround the fused region.

[0055] The present invention is also directed to a catheter system including an inflatable balloon, an optical fiber, an energy source, a fused region, and a ferrule. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can include a first fiber member and a second fiber member. The energy source can be in optical communication with the fiber proximal end of the optical fiber. A fused region can be disposed where the first fiber member is fused to the second fiber member. The ferrule can substantially surround the first fiber member and the fused region.

[0056] The present invention is further directed to a catheter system including an inflatable balloon and an optical fiber. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy in a direction toward the fiber distal end to generate a plasma pulse within the inflatable balloon. The optical fiber can have a larger diameter at the fiber proximal end and can be tapered to have a smaller diameter at the fiber distal end.

[0057] The present invention is also directed to a catheter system including an inflatable balloon and an optical fiber. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can be tapered from the fiber proximal end to the fiber distal end. An energy source can be in optical communication with the fiber proximal end of the optical fiber.

[0058] The present invention is further directed to a catheter system including an inflatable balloon and an optical fiber. The optical fiber can have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon. The optical fiber can be configured to receive an energy pulse such that the optical fiber emits optical energy away from the optical fiber to generate a plasma pulse within the inflatable balloon. The optical fiber can be split into multiple fiber members disposed within the inflatable balloon. An energy source can be in optical communication with the fiber proximal end of the optical fiber.

[0059] In various embodiments, the optical fiber can be tapered from a diameter of 220 μm to a diameter of 100 μm.

[0060] In some embodiments, the optical fiber can be tapered from (i) an initial diameter to (ii) a final diameter that has a diameter between 90% and 10% of the initial diameter.

[0061] In certain embodiments, the catheter system can include a third fiber member and a second fused region, the third fiber member fused to the second fiber member at the second fused region, and the second fiber member further including a second tapered portion.

[0062] The present invention is also directed to a catheter system for treating a treatment site in or adjacent a vessel wall or heart valve. The catheter system may include an inflatable balloon, an optical fiber, an energy source, a first tapered portion, a second tapered portion, a first fused region, a second fused region, and a ferrule. The optical fiber may have (i) a fiber proximal end and (ii) a fiber distal end disposed within the inflatable balloon, the optical fiber configured to receive an energy pulse such that the optical fiber emits optical energy in a direction away from the optical fiber to generate a plasma pulse within the inflatable balloon, the optical fiber having a first fiber member, a second fiber member, and a third fiber member. The energy source may be in optical communication with the fiber proximal end of the optical fiber. The first tapered portion may be disposed on the first fiber member. The second tapered portion may be disposed on the second fiber member. The first fused region, where the first fiber member is fused to the second fiber member. There may be a second fused region where the second fiber member is fused to the third fiber member. The ferrule may substantially surround the first fiber member and the first fused region.

[0063] This summary has outlined some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the subject matter. Further details are found in the detailed description and the appended claims. Other aspects will be apparent to one of ordinary skill in the art upon reading and understanding the following detailed description and viewing the drawings that form a part of the detailed description, each of which is not to be taken in a limiting sense. The scope of this specification is defined by the appended claims and their legal equivalents.

[0064] The novel features of the present invention, as well as the invention itself, both as to its structure and its operation, can best be understood from the accompanying drawings taken in conjunction with the accompanying description, in which like reference characters represent like parts and in which: [Brief description of the drawings]

[0065] [Figure 1] 1 is a schematic cross-sectional view of one embodiment of a catheter system having features of the present invention; [Diagram 2] 1 is a schematic cross-sectional view of one embodiment of a portion of a catheter system including an optical fiber, coupling optics, and an energy source. [Figure 3A] 1 is a schematic cross-sectional view of one embodiment of a portion of a catheter system including an embodiment of an optical fiber. [Figure 3B] 11 is a schematic cross-sectional view of another embodiment of an optical fiber for use in a catheter system. [Figure 3AA] 3B is a cross-sectional view of the optical fiber taken on line 3AA-3AA of FIG. 3A. [Figure 3BB] 3B is a cross-sectional view of the optical fiber taken on line 3BB-3BB of FIG. 3B. [Figure 4A] A schematic cross-sectional view of another embodiment of a catheter system including an embodiment of an optical fiber, coupling optics, and energy source. [Figure 4B] A schematic cross-sectional view of another embodiment of a catheter system including another embodiment of an optical fiber, coupling optics and energy source. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] While the embodiments are susceptible to various modifications and alternative forms, details of which have been shown by way of example and drawings and will be described in detail. It should be understood, however, that the scope of the present specification is not limited to the particular embodiments described. On the contrary, it is intended to cover modifications, equivalents, and alternatives that are within the spirit and scope of the present specification.

[0067] Treatment of vascular lesions can reduce major adverse events or death in affected subjects. Major adverse events are events that may occur anywhere in the body due to the presence of vascular lesions. Major adverse events can include, but are not limited to, major adverse cardiac events, major adverse peripheral or central vascular events, major adverse brain events, major adverse muscle events, or major adverse events of any visceral organs.

[0068] As used herein, a treatment site may include a vascular lesion, such as a calcified or fibrous vascular lesion (hereinafter sometimes simply referred to as a "lesion" or "treatment site") typically found in blood vessels and / or heart valves. Plasma formation may generate a pressure wave and may result in the sudden formation of one or more bubbles that may expand rapidly to a maximum size and then dissipate via a cavitation event that may collapse and also result in a pressure wave. The sudden expansion of the plasma-induced bubbles may generate one or more pressure waves in the balloon fluid, thereby imparting a pressure wave to the treatment site. The pressure wave may transfer mechanical energy to the treatment site through the incompressible balloon fluid, imparting a crushing force to the lesion. Without wishing to be bound by any particular theory, it is believed that a sudden change in balloon fluid momentum at the balloon wall of an inflatable balloon in contact with or located near the lesion is transferred to the lesion and induces the lesion to fracture.

[0069] Those skilled in the art will realize that the following detailed description of the invention is merely illustrative and is not intended to be limiting in any way. Other embodiments of the invention will readily suggest themselves to such skilled artisans having the benefit of this disclosure. Moreover, other methods of delivering energy to the lesion may be utilized, including, but not limited to, current induced plasma generation. Reference will now be made in detail to embodiments of the invention that are illustrated in the accompanying drawings.

[0070] For the sake of clarity, not all of the routine features of the implementations described herein are shown and described. Of course, it will be recognized that in the development of any such actual implementation, many implementation-specific decisions must be made to achieve the developer's particular objectives, such as compliance with application-related and business-related constraints, and that these particular objectives may vary from implementation to implementation and from developer to developer. It will be further recognized that such a development effort may be complex and time-consuming, but may nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

[0071] As used herein, the terms "treatment site," "intravascular lesion," and "vascular lesion" are used interchangeably, unless otherwise noted, and can include lesions located in or near blood vessels or heart valves.

[0072] It is recognized that the catheter systems herein may include many different forms and / or configurations that differ from those specifically shown and / or described herein. Referring now to FIG. 1, a schematic cross-sectional view of a catheter system according to various embodiments herein is shown. The catheter system 100 is adapted to apply pressure to induce fracture in a vascular lesion within or adjacent to a vessel wall and / or heart valve of a blood vessel. In the embodiment shown in FIG. 1, the catheter system 100 may include one or more of a catheter 102, one or more optical fibers 122, a controller 123, an energy source 124, a manifold 136, a fluid pump 138, and a multiplexer (not shown).

[0073] The catheter 102 includes an inflatable balloon 104 (sometimes referred to herein as a "balloon"). The catheter 102 is configured to be moved to a treatment site 106 within or adjacent to a blood vessel 108. The treatment site 106 may include a vascular lesion, such as, for example, a calcified vascular lesion. Additionally or alternatively, the treatment site 106 may include a vascular lesion, such as a fibrotic vascular lesion.

[0074] The catheter 102 can include a balloon 104, a catheter shaft 110, and a guidewire 112. The balloon can be coupled to the catheter shaft 110. The balloon can include a balloon proximal end 104P and a balloon distal end 104D. The catheter shaft 110 can be deployed between a shaft proximal end 114 and a shaft distal end 116. The catheter shaft 110 can include a guidewire lumen 118 configured to travel over the guidewire 112. The catheter shaft 110 can also include an inflation lumen (not shown). In some embodiments, the catheter 102 can include a distal end opening 120 and the catheter 102 can be adapted such that the balloon 104 is positioned at or near the treatment site 106 and can travel over and / or along the guidewire 112.

[0075] The balloon 104 can include a balloon wall 130. The balloon 104 can be deployed from a collapsed configuration suitable for advancing at least a portion of the catheter shaft 102 through a patient's vasculature to an expanded configuration suitable for fixing the catheter 102 in place relative to the treatment site 106.

[0076] The catheter shaft 110 of the catheter 102 can enclose one or more optical fibers 122 (only one optical fiber 122 is shown in FIG. 1 for clarity) in optical communication with the energy source 124. The optical fibers 122 can be disposed at least partially along and / or within the catheter shaft 110 and can be disposed at least partially within the balloon 104. In some embodiments, the catheter shaft 110 can enclose multiple optical fibers 122, such as a second optical fiber, a third optical fiber, etc.

[0077] The optical fiber 122 may vary depending on the design requirements of the catheter system 100 and / or the energy source 124. It is understood that the optical fiber 122 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the optical fiber 122 may omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0078] The optical fiber 122 has a fiber proximal end 122P that is disposed at or adjacent to the energy source 124, and a fiber distal end 122D that may be disposed within the inflatable balloon 104. The optical fiber 122 is deployed between the laser 124 and the balloon 104. The optical fiber 122 is in optical communication with the energy source 124. It will be appreciated that the optical fiber 122 may be replaced with any suitable optical carrier (the optical fiber 122 is an optical carrier) configured to carry one or more sub-millisecond energy pulses, and / or any suitable energy source.

[0079] The controller 123 may control the energy source 124 to cause the energy source 124 to generate one or more energy pulses, as provided in more detail herein. The controller 123 may also perform any other functions related to controlling the operation of the catheter 102.

[0080] The energy source 124 of the catheter system 100 can be configured to provide one or more sub-millisecond energy pulses that are delivered to and received by the optical fiber 122. The optical fiber 122 acts as a conduit for the optical energy generated by the energy pulses. In certain embodiments, the energy source 124 (sometimes referred to herein as a "laser") can include a laser. In some such embodiments, the laser 124 can include one or more seed sources 126 and one or more amplifiers 128. Each amplifier 128 can be in optical communication with at least one of the multiple seed sources 126. The seed sources 126 can each emit a relatively low power seed pulse that is received and amplified by the amplifier 128. The amplifier 128 can increase the power of the seed pulse to generate the energy pulse. In one embodiment, the laser 124 can include one seed source 126 and one amplifier 128.

[0081] Alternatively, laser 124 may include multiple seed sources 126 and an amplifier 128. Further alternatively, laser 124 may include multiple seed sources 126 and multiple amplifiers 128. It will be appreciated that laser 124 may be replaced with any suitable energy source (laser 124 being the energy source) configured to provide one or more sub-millisecond energy pulses that are delivered to and received by optical fiber 122.

[0082] The optical energy produced by the energy pulse is delivered by the optical fiber 122 to a location within the balloon 104. The optical energy induces plasma formation in the form of a plasma pulse 134 that occurs within the balloon fluid 132 within the balloon 104. The plasma pulse 134 results in rapid bubble formation and imparts a pressure wave at the treatment site 106. An exemplary plasma pulse 134 is shown in FIG. 1. The balloon fluid 132 may be a liquid or a gas. As provided in more detail herein, the plasma-induced bubbles 134 are purposely formed some distance from the optical fiber 122 to reduce the potential for damage to the optical fiber.

[0083] In various embodiments, sub-millisecond light pulses with frequencies of at least about 1 Hertz (Hz) up to about 5000 Hz may be delivered proximate to the treatment site 106. In some embodiments, sub-millisecond light pulses with frequencies of at least 30 Hz to 1000 Hz may be delivered proximate to the treatment site 106. In other embodiments, sub-millisecond light pulses with frequencies of at least 10 Hz to 100 Hz may be delivered proximate to the treatment site 106. In still other embodiments, sub-millisecond light pulses with frequencies of at least 1 Hz to 30 Hz may be delivered proximate to the treatment site 106.

[0084] It is recognized that the catheter systems 100 herein can include any number of optical fibers 122 in optical communication with the laser 124 at the proximal portion 114 and in optical communication with the balloon fluid 132 within the balloon 104 at the distal portion 116. For example, in some embodiments, the catheter systems 100 herein can include between 1 and 30 optical fibers 122. In some embodiments, the catheter systems 100 herein can include 30 or more optical fibers.

[0085] The manifold 136 can be disposed at or near the shaft proximal end 114. The manifold 136 can include one or more proximal end openings that can receive one or more optical fibers, such as the optical fiber 122, the guidewire 112, and / or an inflation conduit 140. The catheter system 100 can also include a fluid pump 138 configured to inflate the balloon 104 with balloon fluid 132 and / or deflate the balloon 104 as needed.

[0086] A multiplexer (not shown) communicates a single energy source with one or more of the multiple optical channels in a tightly controlled manner. In this manner, a single energy source can be sequentially channelized through a variable number of multiple channels.

[0087] As with all embodiments shown and described herein, various features may be omitted from the figures for clarity and ease of understanding. Additionally, the figures may include certain features that may be omitted without departing from the spirit and scope of the present invention.

[0088] 2 is a schematic cross-sectional view of one embodiment of an optical fiber 222, coupling optics 242, and energy source for use in the catheter system 100 (in the embodiment shown in FIG. 2, the energy source is a laser 224). The laser 224 can generate energy pulses that are directed toward the coupling optics 246. The laser 224 can be a pulsed IR laser or any suitable laser. In various embodiments, the catheter system 100 can include one or more emitters 260 distributed along an effective length of a calcified vascular lesion located at the treatment site 106.

[0089] The energy sources described herein may be any suitable energy source for use within the catheter system 100. In some embodiments, the optical fiber 222 may be replaced by any suitable optical carrier configured to receive an energy pulse. The optical fiber 222 may receive the energy pulse and direct the energy pulse toward the emitter 260.

[0090] The coupling optics 242 couples the energy pulse into the optical fiber 222 and redirects it toward the optical fiber 222. The coupling optics 242 may vary depending on the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. It is understood that the coupling optics 242 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the coupling optics 242 may omit one or more of the systems, subsystems, and elements specifically shown and / or described herein. The coupling optics 242 may include a reflector 244 and a lens 246. The reflector 244 may reflect the energy pulse toward the lens 246. The lens 246 may focus the energy pulse so that the optical fiber 222 receives an energy pulse of an appropriate diameter and / or size.

[0091] In the embodiment shown in FIG. 2, the optical fiber 222 can include a ferrule 248, a first fiber member 250, a tapered portion 252 having a tapered portion length 254, a fused region 256, a second fiber member 258, and an emitter 260.

[0092] The ferrule 248 can organize and align the optical carrier (e.g., optical fiber 222) to the coupling optics 242 in the multiplexer (not shown). The ferrule 248 can vary depending on the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. It is understood that the ferrule 248 can include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the ferrule 248 can omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0093] The ferrule 248 may be a rigid member configured to confine and support the optical fiber and may also serve as a connector and / or mechanical joint in the catheter system 199. The ferrule 248 may substantially surround any portion of the optical fiber 222.

[0094] In certain embodiments, the systems and methods described herein can include a segmented optical carrier (e.g., optical fiber 222) that has a larger diameter at its fiber proximal end and tapers to a smaller diameter toward the fiber distal end. Alternatively, the optical carrier can have a larger diameter at the fiber distal end and tapers to a smaller diameter at the fiber proximal end.

[0095] The distal section (e.g., second fiber member 258) may consist of a single optical carrier or multiple optical carriers coupled to an emitter 260. The proximal section (e.g., first fiber member 250) may also consist of a single optical carrier or multiple optical carriers coupled to coupling optics 242. Tapered optical carriers can improve pressure wave generation and performance of the catheter system 100.

[0096] The first fiber member 250 can be configured to be secured to the ferrule 248. The first fiber member 250 can be a segment of the optical fiber 222 that is proximal to the laser 224 and the coupling optics 242. The first fiber member 250 can vary depending on the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. It is understood that the first fiber member 250 can include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the first fiber member 250 can omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0097] In certain embodiments, the first fiber member 250 can include a first tapered portion 252. In other embodiments, the first fiber member 250 can be separately attached or bonded to the tapered portion 252. The first fiber member 250 can be tapered and / or otherwise modified to have a modified shape. The first fiber member 250 can be an individual fiber or fiber member that is attached to the tapered portion 252 and / or the second fiber member 258.

[0098] The tapered section 252 allows the optical fiber 222 to have a smaller diameter at its distal portion (e.g., at the second fiber member 258). The tapered section 252 can vary depending on the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. The shape, taper, and / or dimensions of the tapered section 252 can also vary. The tapered section 252 can have a taper length 254. The taper length 254 can have a variable length depending on the design requirements of the catheter system 100 and / or the optical fiber.

[0099] The location of the tapered portion 252 on the optical fiber 222 can vary. In some embodiments, the tapered portion 252 is located very close to the coupling optic 242. In other embodiments, the tapered portion 252 is located closer to the balloon 104. It is recognized that the tapered portion 252 can be located anywhere along the optical fiber 222. In some embodiments, the optical fiber 222 can include multiple tapered portions 252 located along varying locations of the optical fiber 222. It is recognized that the optical fiber 222 can include any number of tapered portions 252 to meet the design requirements of the catheter system 100 and / or the optical fiber 222.

[0100] The fused region 256 can be formed by fusing the first fiber member 250 with the second fiber member 258. The fused region 256 can join together fibers and / or fiber members of different diameters. In some embodiments, the fused region 256 can be fused around a split and / or splice portion of the optical fiber 222 (as shown in FIGS. 3AA and 3BB) such that two separate portions of the optical fiber 222 can be joined.

[0101] The fused region 256 may vary depending on the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. The shape and / or size of the fused region 256 may also vary. The location of the fused region 256 on the optical fiber 222 may vary. In some embodiments, the fused region 256 is located very close to the coupling optic 242. In other embodiments, the fused region 256 is located closer to the balloon 104. It is recognized that the fused region 256 may be located anywhere along the optical fiber 222.

[0102] The second fiber member 258 may be substantially similar to the first fiber member 250. However, in certain embodiments, the second fiber member 258 may have a smaller diameter than the first fiber member 250. The second fiber member 258 may be a segment of the optical fiber 222 that is distal to the laser 224 and the coupling optics 242. The second fiber member 258 may be in optical communication with an emitter 260.

[0103] The second fiber member 258 can vary depending on the design requirements of the catheter system 100, the optical fiber 222, the first fiber member 250, the tapered section 252, and / or the emitter 260. It is understood that the second fiber member 258 can include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the second fiber member 250 can omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0104] Although a first fiber member 250 and a second fiber member 258 are described herein, it is recognized that the optical fiber 222 can include any number of fiber members. In some embodiments, the optical fiber 222 includes up to 50 fiber members. In other embodiments, a first fiber member 250 having a first tapered portion (not shown) can be fused to a second fiber member 258 having a second tapered portion (not shown), which can be fused to a third fiber member (not shown). The optical fiber 222 can include any number of fiber members, each of which can have any number of tapered portions and each of which can include any number of fused sections and / or other attachment points, as known in the art.

[0105] The emitter 260 can be driven by an energy source. The emitter 260 can be a plasma generator. The optical fiber 222 can include one or more emitters 260. The emitter 260 can be located anywhere along the portion of the optical fiber 222 that is disposed inside the balloon 104. The emitter 260 can provide one or more plasma pulses 134.

[0106] Emitter 260 may vary depending on the design requirements of catheter system 100, optical fiber 222, and / or laser 224. It is understood that emitter 260 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, emitter 260 may omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0107] One method for tapering an optical carrier (e.g., tapering the optical fiber 222) involves tapering a larger proximal section by heating, drawing, and then cleaving it at the smaller end. An optical carrier assembly can be formed by fusing the smaller diameter end to a smaller diameter carrier for the distal section. The optical carrier can be fused using a fusion joint.

[0108] Another embodiment of the tapering method can include successively heating and drawing the proximal section to produce a longer optical carrier with a smaller diameter for the distal section. The tapering method can include creating a short tapered portion 252 and fusing the large and small ends to a matching diameter optical carrier. This embodiment can require two fusion joints.

[0109] In certain embodiments, an optical carrier (e.g., optical fiber 222) coupled to a laser-driven pressure wave generating device (e.g., emitter 260) can include three subsections. The proximal section can use an optical carrier with a larger core diameter than the distal section. The proximal section of the optical carrier has a diameter D p and cut the distal section to a diameter of D d The proximal section may taper to or be coupled into a tapered section having a reduced diameter to match the distal end of the proximal section. Light energy may be coupled into an end face of the proximal section.

[0110] The larger diameter of the proximal face may reduce the precision required to form the combined optical energy beam and align the coupling optics 242 to the light guide (e.g., optical fiber 222). This design may reduce the multiplexer precision requirements and the opto-mechanical tolerances for connectorizing the optical carrier. The tapered section 252 conserves the energy pulse and transmits it to the smaller diameter carrier with minimal loss.

[0111] In certain embodiments, etendue is maintained within the light guide. Etendue maintenance requires that the product of numerical aperture (NA) and diameter remain constant. Thus, the NA of the tapered distal section is NA d =(D p / D d )NA p For example, an optical fiber 222 with an inherent NA=0.22 that is tapered from 200 microns to 100 microns increases the NA to NA=0.44. When the tapered smaller diameter end is fused to a light guide with a similar NA=0.22, this results in a fiber cladding with less significant coupling loss due to mismatch.

[0112] In various embodiments, the optical fiber 222 can be tapered from 220 microns to 100 microns. The optical fibers 222 described herein can be tapered to 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 360 μm, 380 μm, 400μm, 420μm, 440μm, 460μm, 480μm, 500μm, 520μm, 540μm, 560μm, 580μm, 600μm, 620μm, 740μm, 760μm, 780μm, 800μm, 850μm, 900μm, from an initial diameter of 1mm or from an initial diameter of more than 1mm, less than 1mm, 1μm, 1μm, 2μm, 2μm, 3μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm, 41μm, 420μm, 430μm, 440μm, 450μm, 460μm, 470μm, 480μm, 490μm, 500μm, 510μm, 520μm, 540μm, 560μm, 580μm, 600μm, 6 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm m, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 220μm, 240μm, 260μm, 280μm, 300μm, 320μm , 340 μm, 360 μm, 380 μm, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm, 500 μm, 520 μm, 540 μm, 560 μm, 580 μm, 600 μm, 620 μm, 740 μm, 760 μm, 780 μm, 800 μm, 850 μm, 900 μm. It is recognized that the optical fibers and / or optical carriers shown and / or described herein can be tapered to have final and initial diameters that can fall within certain ranges, all of which numbers above can serve as lower or upper boundaries of the ranges, provided that the lower boundary of the range is less than the upper boundary of the range. The optical fibers and / or optical carriers described herein can have final and initial diameters that are outside of the ranges described herein.

[0113] One way to avoid coupling losses is to use an optical carrier with a smaller NA on the proximal end of the fiber with a larger diameter, and an optical carrier with a larger NA by a factor of the diameter for the smaller distal section. p From D d The tapering process to match the numerical aperture of the two sections. In some embodiments, tapered portion 252 can be formed to provide an adiabatic change in optical curvature, with the resulting NA minimizing losses through the transition.

[0114] Stimulated Brillouin Scattering (SBS) is a nonlinear process in optical carriers that can limit the total energy transmission. In SBS, an intense beam of optical energy can interact with an acoustic wave in a medium, resulting in a weak reflected beam. The reflected beam is commonly called a Stokes wave, and the original beam can then interfere to amplify the acoustic wave through electrostriction. The power in the reflected beam can increase nonlinearly with the input beam power. As a result, the energy throughput can be continuously reduced with the input power, effectively clamping the peak transmitted power, thereby significantly limiting the conversion efficiency and yield of the emitter.

[0115] SBS depends on many variables including the wavelength and bandwidth of the input optical energy, the physical properties of the optical carrier medium and its mechanical dimensions. Typically, doubling the diameter of a light guide quadruples the power threshold for initiating SBS. SBS occurs in the region of the light guide closer to the emission end. If this can be avoided in a larger carrier, all the power emitted into the carrier can be coupled into the smaller optical carrier. By making the diameter of the proximal section larger, significantly more power can be coupled into the light guide assembly and transmitted to the fiber distal end.

[0116] In some embodiments, the proximal optical carrier may be a doped optical fiber to improve transmission characteristics and further suppress the onset of SBS. Some examples of suitable dopants are GeO2, P2O3, TiO2, B2O3, F2, A12O3. Doped fibers can be much more expensive per unit length than conventional pure silica fibers.

[0117] With this approach, a shorter length of expensive fiber can be used to suppress SBS using a much longer assembly of lower cost fiber. Another approach can be to implement a shorter length of photonic crystal fiber, hollow-core fiber, chiral fiber, or similar structured optical fiber in the proximal section and traditional pure silica fiber through the longer length of catheter system 100. With this configuration, a shorter length of more expensive fiber can be used in the proximal section to achieve similar results with a lower cost distal section.

[0118] Figure 3A is a schematic cross-sectional view of one embodiment of an optical fiber 322 for use within the catheter system 100. As shown in Figure 3A, the optical fiber 322 can include a first fiber member 350, a fused region 356, and a second fiber member 358 that includes second fiber legs 362A-C. The optical fiber 322 can include any number of second fiber legs 362.

[0119] The optical fiber 322 can include a single proximal section coupled to multiple distal sections. In this embodiment, three distal carriers (e.g., second fiber legs 362A-C) can be fused to a single proximal carrier. The distal carrier can have the same diameter as that used in the proximal section, or the distal carrier can have a smaller diameter. In other embodiments, the distal section includes N optical carriers that are smaller in diameter than the proximal section.

[0120] the total end surface area of ​​the distal section is equal to the total end surface area of ​​the proximal section;

number

[0121] One advantage of the embodiment shown in FIG. 3A is that it eliminates the need to split the energy source into two separate beams and couple each of those beams into a separate optical carrier when simultaneously powering two emitters 260. This embodiment can have the additional advantage of simplifying the multiplexer architecture and optics. The embodiment shown in FIG. 3A can also reduce losses from having two separate beam paths and separate Fresnel losses at the end faces of the two optical carriers.

[0122] Although there may be significant losses in a fused splitter (e.g., fused region 356), these losses may be comparable to the losses in a two-leg multiplexer architecture with complex coupling optics. Fused splitters can simplify the multiplexer architecture, reduce alignment tolerances allowing for simpler optics with improved transmission, and eliminate losses due to splitting the optics and emission interface.

[0123] 3B is a schematic cross-sectional view of another embodiment of an alternative optical fiber 322 for use in the catheter system 100. The embodiment shown in FIG. 3B shows a highly optimized 1×2 splitter that transitions from a 200 μ core proximal section to two 105 μm core distal sections. The transition between the sections can be optimized by tapering the proximal optical carrier to have an area equal to twice the area of ​​the 105 μm carrier. The two distal carriers can be shaped to better match the fiber proximal ends.

[0124] A separate capillary 364 can be placed around the fusion assembly (e.g., fusion region 356) and fused to optimize cross-section and area matching. This approach can be used to improve coupling efficiency for any number of carriers in the splitter. The capillary 364 can be pulled to tight tolerances and can be well suited for use in the catheter system 100. The capillary 364 can vary depending on the design requirements of the catheter system 100 and / or the optical fiber 322. It is understood that the capillary 364 can include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. Additionally or alternatively, the capillary 364 can omit one or more of the systems, subsystems, and elements specifically shown and / or described herein.

[0125] Figure 3AA is a cross-sectional view of the optical fiber taken on line 3AA-3AA in Figure 3A. As shown in Figure 3AA, this cross-sectional view establishes that fused region 356 can include first fiber member 350 and second fiber member legs 362A-C. First fiber member 350 can be fused to second fiber member legs 362A-C at different locations such that portions of the outer periphery of first fiber member 350 are fused to portions of the outer periphery of second fiber leg 362A, second fiber leg 362B, and second fiber leg 362C.

[0126] Figure 3BB is a cross-sectional view of the optical fiber taken on line 3BB-3BB of Figure 3B. As shown in Figure 3BB, this cross-sectional view demonstrates that fused region 356 can include first fiber member 350 and second fiber member legs 362A-B. Fused region 356 is substantially surrounded by capillary 364.

[0127] 4A is a schematic cross-sectional view of another embodiment of an optical fiber 422A, coupling optics 442A (e.g., reflector 444A and lens 446A), and an energy source (e.g., laser 424A) for use within catheter system 100 (shown in FIG. 1). In some embodiments, optical fiber 422A can include a ferrule 448A, a first fiber member 450A, a fused region 456A, an emitter 460A, and an end cap 466A.

[0128] The end cap 466A can provide a larger surface area for expanding the converging incident beam before the end cap 466A focuses the energy source and couples it into the optical carrier. The shape, configuration, and size of the end cap 466A can vary depending on the design requirements of the catheter system 100 and / or the optical fiber 422A. In one embodiment, the end cap 466A can have a substantially cylindrical configuration. Alternatively, the end cap 466A can have another suitable configuration.

[0129] The embodiment shown in Figure 4A shows a direct approach to improved coupling to smaller optical carriers using an end cap 466A fused to the proximal end. In general, the damage threshold for optical materials is much lower at the air interface than in the bulk material, sometimes by an order of magnitude.

[0130] This approach can reduce the peak radiant flux density at the surface, thereby increasing the damage threshold for the optical carrier assembly. The damage threshold near the end face of the optical carrier is closer to the bulk threshold for the material of construction. This embodiment allows for significantly larger amounts of energy to be coupled into the small diameter optical carrier. The converging incident beam can be precisely centered on the end cap 466A and precisely aligned within the ferrule 448A to achieve optimal coupling alignment. In certain embodiments, precise alignment is required to center the converging incident beam on the end cap 466A.

[0131] FIG. 4B is a schematic cross-sectional view of another embodiment of an optical fiber 422B, coupling optics 442B, and energy source (e.g., laser 424B) for use in the catheter system 100 (shown in FIG. 1). The embodiment shown in FIG. 4B features a tapered assembly. A tapered optical carrier may be a short section (e.g., tapered portion 452B) enclosed within a ferrule 456B. This approach can defocus the incident beam and provide a large end face for coupling high energy, thereby increasing the assembly damage threshold. At the same time, the embodiment of FIG. 4B can reduce alignment requirements with a smaller optical carrier via light guiding of energy through tapered portion 452B.

[0132] The present invention is also directed to methods for treating a treatment site 106 (shown in FIG. 1) within or adjacent a blood vessel wall or heart valve using such methods utilizing the devices disclosed herein.

[0133] fiber Optical fibers suitable for use herein can include various types of fibers suitable for optical communication with energy sources such as lasers and lamps. In some embodiments, the optical fibers can include fiber connectors and fiber tapers. Fiber tapers can be implemented using solid metal tubes that are tens of millimeters in length. To convert light from a large core fiber to a small core fiber, a fiber taper that tapers from a larger core fiber to a smaller core for splicing can be an effective method to minimize insertion loss. In certain embodiments, the fiber taper can be integrated into a fiber connector and can form a new type of fiber device called a tapered fiber connector.

[0134] Fiber connectors can be configured to couple light from one fiber to another. Fiber connectors can include a polished ferrule. The fiber can be surrounded within the fiber connector with epoxy. There are dozens of different styles of fiber connectors, including ferrules with an outer diameter of 1.25 mm LC and ferrules with an outer diameter of 2.5 mm SC. The inner diameter of the ferrule is determined by the fiber size, sometimes between 126 and 127 μm in diameter for single mode fiber.

[0135] In some embodiments, the ferrules described herein may be 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 510 μm, 520 μm, 530 μm, 540 μm, 550 μm, 560 μm, 570 μm, 580 μm, 590 μm, 600 μm, 610 μm, 620 μm, 630 μm, 640 μm, 650 μm, 660 μm, 670 μm, 680 μm, 690 μm, 700 μm, 710 μm, 720 μm, 730 μm, 740 μm, 750 μm, 760 μm, 770 μm, 780 μm, The diameter (both inner and outer diameters) can be 60 μm, 380 μm, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm, 500 μm, 520 μm, 540 μm, 560 μm, 580 μm, 600 μm, 620 μm, 740 μm, 760 μm, 780 μm, 800 μm, 850 μm, 900 μm, 1 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm or more, or greater than 4.0 mm. It is recognized that the ferrules shown and / or described herein can have diameters (both inner and outer diameters) that can fall within a range, and that all of the above numbers can serve as lower or upper boundaries of that range, provided that the lower boundary of the range is less than the upper boundary of the range. The ferrules described herein can have diameters (both inner and outer diameters) that are outside of the ranges described herein.

[0136] For high power laser-fiber coupling, a large-diameter core fiber can be used to reduce the power density at the fiber coupling surface, thereby enhancing the damage threshold. However, large-diameter fibers are not flexible for many applications, such as catheters for medical treatment. In these applications, the conversion of optical power from a large-diameter fiber to a small-diameter fiber is critical. The connection or splicing of a large-core fiber with a small-core fiber can directly lead to unacceptable insertion loss.

[0137] One embodiment of a method for converting optical power involves tapering a larger diameter core fiber to match a smaller diameter core fiber, and then splicing the fiber taper to the smaller core fiber. However, the fiber taper and splice joint must be well implemented, and a typical 3 mm diameter, 50 mm long metal pipe is prohibitively inconvenient for many applications.

[0138] By integrating a fiber connector with a fiber taper, a new type of fiber connector is created: a tapered fiber connector. This type of fiber connector is constant in size, but the fiber taper is surrounded by epoxy. Any suitable type of fiber connector, including an all-single mode fiber connector, can be modified to become a tapered fiber connector for receiving light, since the lateral offset does not introduce any significant loss.

[0139] In various embodiments, a fusion splicer can taper the fiber and splice the fiber taper onto the small core fiber. In other embodiments, other devices and methods can be used to taper the fiber and splice the fiber taper onto the small core fiber. The fiber can be tapered using a hydrogen flame to heat a central section of the fiber that is held under tension. The fiber can be tapered using devices and methods known in the art.

[0140] The fiber taper and the bonded joint can be surrounded with epoxy within the fiber ferrule for polishing. Epoxies that can be used herein include thermal epoxies, room temperature curing epoxies (such as ND353), UV curing epoxies (such as LOCTITE® 4310 UV adhesive), and other suitable epoxies known in the art. Processing can be simple and low cost, and the fiber connector integrated with the fiber taper can be configured for high power laser coupling. One type of fiber connector that can be used is a fiber end cap for high power laser input and output where the power density at the fiber surface is small. Fiber end caps may require precise alignment because the end cap glass is equivalent to free space rather than a waveguide. However, fiber tapers can still function as a waveguide, and therefore alignment is not necessary.

[0141] In some embodiments, a fiber with a core / cladding diameter of 200 / 220 μm is selected to couple a high power laser, and a fiber with a core / cladding diameter of 105 / 125 μm is used to build a catheter for medical treatment, where the process of converting the laser power from the larger diameter core fiber to the smaller core fiber is critical.

[0142] For example, if a larger fiber with core / cladding diameters of 200 / 220 μm is directly spliced ​​onto a smaller fiber with core / cladding diameters of 105 / 125 μm, most of the light will not be coupled from the larger fiber into the smaller fiber, resulting in high insertion loss. As an estimate, the ratio of the two core overlaps is:

number

number

[0143] Equations 1 and 2 can be simplified to:

number

[0144] NA is the numerical aperture of the fiber, and for a 0.22 numerical aperture, the maximum angle of incidence α is 12.7 degrees. For a non-tapered fiber, the angle of the light remains constant along the fiber and is emitted at the same angle α. However, for a tapered fiber, the emission angle can be larger than the angle of incidence α depending on the taper angle and length.

[0145] If the angle of incidence of the light is small enough, or the light beam effective NA is significantly smaller than the NA2 of a small fiber with a particular taper angle and taper length, the effective NA of the light emerging from the fiber taper will still be within the smaller fiber acceptable angle range of arcsin(NA2), which can be 12.7 degrees for a 0.22 numerical aperture. The taper angle δ is

number

[0146] In a specific embodiment, when a 3 mm diameter collimated free-space laser beam is focused by a 50 mm focusing lens and coupled into a fiber taper, the NA of the incident beam is

number

[0147] The angle of the light increases by 2δ after every reflection on the surface of the fiber taper, so the pitch between two reflections along the fiber becomes shorter and shorter while the angle becomes larger and larger. To prevent light leakage from the fiber core into the cladding, the maximum angle of the light must not be larger than arcsin(NA2).

[0148] If a free-space laser beam with a diameter of 3 mm is focused by a lens with a focal length of 50 mm, then when a large diameter fiber of 200 μm is tapered into a small core of 105 μm (fiber taper 200 / 105 μm), the fiber taper can convert all the light from the large core fiber to the small core fiber of 105 μm without any light leaking into the fiber cladding at the tapered region and at the splice joint.

[0149] Simulations show that when larger diameters of 200μm, 300μm and 400μm are tapered to a small core of 105μm with a taper length of 5mm, all the light from the larger diameter core fiber can be fully coupled into the small core fiber like a light funnel. Simulations show that for a fiber taper of 1000 / 105μm and a taper length of 5mm, light leaks from the fiber core to the cladding, resulting in significant insertion loss as shown below. Simulations also show that for a fiber taper of 200 / 105μm, the light emission angle with respect to the taper length is curved. In general, a smaller angle or beam size is desirable, so the optimal taper length is at least 4-5mm.

[0150] In some embodiments, a 500 μm core diameter can be tapered to a small core of 105 μm for light conversion. However, simulations show that the tapering length must be longer than 5 mm to avoid light leakage into the cladding. To achieve a smaller emission angle, the tapering length can be as long as 15 mm.

[0151] The FSM100P fiber fusion splicer can taper fibers up to 500μm larger to smaller sizes. Compared to 105 / 125μm fibers for high power optical coupling, larger diameter fibers can significantly reduce power density. For tapered connectors with fiber tapers of 200μm, 300, 400μm and 500μm diameter, the power density can be reduced by a factor of 4, 8, 15 and 22, respectively. The fiber fusion splicing for taper causes the fiber core to stretch slightly, and the fiber core diameter is tapered to a slightly smaller size, for example, a 200μm core diameter tapers to a 95μm core or smaller to match a 105 / 125μm fiber.

[0152] In some embodiments, the optical fibers and / or optical carriers described herein may have a fiber optic length of 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm, 410 μm, 420 μm, 430 μm, 440 μm, 450 μm, 460 μm, 470 μm, 480 μm, 490 μm, 500 μm, 510 μm, 520 μm, 530 μm, 540 μm, 550 μm, 560 μm, 570 μm, 580 μm, 590 μm, 600 μm, 610 μm, 620 μm, 630 μm, 640 μm, 650 μm, 660 μm, 670 μm, 680 μm, 690 μm, 700 μm, 710 μm, 720 μm, 730 μm, 740 μm, 750 μm, 760 μm, 770 μm, 780 μm, 790 , 320 μm, 340 μm, 360 μm, 380 μm, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm, 500 μm, 520 μm, 540 μm, 560 μm, 580 μm, 600 μm, 620 μm, 740 μm, 760 μm, 780 μm, 800 μm, 850 μm, 900 μm, 1 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm or more, or greater than 3.0 mm. It is recognized that the optical fibers and / or optical carriers shown and / or described herein may have diameters that may fall within a range, with all of the above numbers serving as lower or upper boundaries of the range, provided that the lower boundary of the range is less than the upper boundary of the range. The optical fibers and / or optical carriers described herein may have diameters that are outside the ranges described herein.

[0153] In various embodiments, the optical fibers and / or optical carriers described herein may have a taper length of 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, 7.0 mm, 7.5 mm, 8.0 mm, 8.5 mm, 9.0 mm, 9.5 mm, 10.0 mm, 11.0 mm, 12.0 mm, 13.0 mm, 14.0 mm, 15.0 mm, 20 mm, 25 mm, 30 mm or more, or greater than 30 mm. It is recognized that the optical fibers and / or optical carriers shown and / or described herein may have a taper length that may fall within a range, with all of the above numbers serving as lower or upper bounds of the range, provided that the lower bound of the range is less than the upper bound of the range. The optical fibers and / or optical carriers described herein may have tapered lengths that are outside the ranges described herein.

[0154] laser Lasers suitable for use herein can include various types of lasers, including lasers and lamps. Suitable lasers can include short pulsed lasers on the sub-millisecond timescale. In some embodiments, the lasers can include nanosecond (ns) timescale lasers. Lasers can also include picosecond (ps), femtosecond (fs) and microsecond (us) timescale short pulsed lasers as well. It is recognized that there are many combinations of laser wavelengths, pulse widths and energy levels that can be used to achieve plasma in the balloon fluid of the catheters shown and / or described herein. In various embodiments, the pulse width can include a pulse width that falls within a range of at least 10 ns to 200 ns, inclusive. In some embodiments, the pulse width can include a pulse width that falls within a range of at least 20 ns to 100 ns, inclusive. In other embodiments, the pulse width can include a pulse width that falls within a range of at least 1 ns to 5000 ns, inclusive.

[0155] Exemplary nanosecond lasers can include lasers in the UV to IR spectrum, ranging in wavelength from about 10 nanometers to 1 millimeter. In some embodiments, lasers suitable for use in the catheter systems herein can include lasers capable of generating light at wavelengths of at least 350 nm to 2000 nm. In some embodiments, the lasers can include lasers capable of generating light at wavelengths of at least 700 nm to 3000 nm. In some embodiments, the lasers can include lasers capable of generating light at wavelengths of at least 100 nm to 10 micrometers (μm). Nanosecond lasers can include lasers having repetition rates up to 200 kHz. In some embodiments, the lasers can include Q-switched Thulium:Yttrium-Aluminum-Garnet (Tm:YAG) lasers. In some embodiments, the laser can include neodymium:yttrium-aluminum-garnet (Nd:YAG), holmium:yttrium-aluminum-garnet (Ho:YAG), erbium:yttrium-aluminum-garnet (Er:YAG), excimer lasers, helium-neon lasers, carbon dioxide lasers, and doped pulsed fiber lasers.

[0156] Pressure Waves The catheters shown and / or described herein can generate pressure waves having a maximum pressure ranging from at least 1 megapascal (MPa) to 100 MPa. The maximum pressure waves generated by a particular catheter will depend on the laser, the absorbing material, the bubble expansion, the propagation medium, the balloon material, and other factors. In some embodiments, the catheters shown and / or described herein can generate pressure waves having a maximum pressure ranging from at least 2 MPa to 50 MPa. In other embodiments, the catheters shown and / or described herein can generate pressure waves having a maximum pressure ranging from at least 2 MPa to 30 MPa. In still other embodiments, the catheters shown and / or described herein can generate pressure waves having a maximum pressure ranging from at least 15 MPa to 25 MPa. In some embodiments, the catheters shown and / or described herein can generate pressure waves having peak pressures of 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa or 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31 MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39 MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa or 50 MPa or more. It will be appreciated that the catheters shown and / or described herein can generate pressure waves having operating pressures or maximum pressures that can fall within a range, and all of the above numbers can serve as lower or upper boundaries of that range, provided that the lower boundary of the range is a value that is less than the upper boundary of the range.

[0157] The therapeutic treatment may be applied via a fatigue mechanism or a force mechanism. For a fatigue mechanism, the operating pressure will be at least about 0.5 MPa to 2 MPa, or about 1 MPa. For a force mechanism, the operating pressure will be at least about 20 MPa to 30 MPa, or about 25 MPa. Pressures between the extremes of these two ranges may be applied to the treatment site using a combination of the fatigue and force mechanisms.

[0158] The pressure waves described herein can be applied to the treatment site from a distance extending radially from the longitudinal axis of the catheter placed at the treatment site within a range of at least 0.01 millimeters (mm) to 25 mm. In some embodiments, the pressure waves can be applied to the treatment site from a distance extending radially from the longitudinal axis of the catheter placed at the treatment site within a range of at least 1 mm to 20 mm. In other embodiments, the pressure waves can be applied to the treatment site from a distance extending radially from the longitudinal axis of the catheter placed at the treatment site within a range of at least 0.1 mm to 10 mm. In still other embodiments, the pressure waves can be applied to the treatment site from a distance extending radially from the longitudinal axis of the catheter placed at the treatment site within a range of at least 1.5 mm to 4 mm. In some embodiments, the pressure waves can be applied to the treatment site from a range of at least 2 MPa to 30 MPa at a distance of 0.1 mm to 10 mm. In some embodiments, the pressure waves can be applied to the treatment site from a range of at least 2 MPa to 25 MPa at a distance of 0.1 mm to 10 mm. In some embodiments, the pressure waves can be applied to the treatment site from a distance that may be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm or more, or the pressure waves may be at a distance that falls within a range between any of the above distances, or at a distance outside any of the above distances.

[0159] The systems and methods described herein provide improved optical coupling to individual optical carriers organized into multi-channel arrays, the benefits of which include higher damage thresholds and coupling efficiencies while reducing mechanical tolerance requirements.

[0160] The systems and methods provided herein improve the optical damage threshold and energy throughput while maintaining a small diameter section leading to the plasma generator. The benefits of improved optical damage threshold and energy throughput are minimized mechanical cross section and minimized bending stiffness of the light guide bundle and catheter.

[0161] In accordance with the systems and methods provided herein, a larger optical carrier can be used in the proximal section of a single-use device (sometimes referred to herein as a "SUD"), where the optics can be easily aligned with the light for coupling the light, while a smaller carrier can be used in the distal section to optimize key mechanical properties such as cross profile and bending stiffness. The advantages of this approach are: 1) reduced requirements for connector tolerances for aligning the optical carriers to the coupling optics and the mechanical tolerances of their location in the multichannel array; 2) reduced dependency of system performance on the precision of connecting and aligning the multichannel array to the multiplexer; 3) reduced dependency on the precision of the positioning mechanisms in the multiplexer and the associated quality and precision of its optical and mechanical components; 4) reduced cost by allowing the use of lower cost, less precise ferrules on the SUD; 5) higher optical damage threshold at the proximal end face of the optical carrier, allowing for higher energies to drive the emitters; and 6) reduced transmission losses in the optical carrier due to nonlinear optical processes, which increase as the diameter of the optical carrier decreases.

[0162] The systems and methods described herein reduce the assembly precision and mechanical tolerance stack-up and optical coupling dependency on true alignment for optical carriers, ferrules, connectors and receptacles, thereby enabling the use of lower cost, lower precision components on the SUD and improving cost of goods sold.

[0163] The systems and methods described herein reduce the dependency of multiplexer performance on the accuracy of the positioning mechanisms and the associated quality and accuracy of its optical and mechanical components, thereby improving the speed and performance of multiplexers and multi-channel ferrule systems.

[0164] The systems and methods described herein increase the damage threshold of the optical carrier and allow for greater coupling of energy into the optical carrier and to the emitter, while enabling the use of smaller carriers through critical sections of the catheter.

[0165] It should also be noted that, as used in this specification and the appended claims, the phrase "configured to" describes a system, apparatus, or other structure that is constructed or configured to perform a particular task or adopt a configuration of characteristics. The phrase "configured to" can be used interchangeably with other similar phrases, such as arranged and configured, built and arranged, built, manufactured and arranged, etc.

[0166] As used herein, the recitation of numerical ranges by endpoints is intended to include all numbers subsumed within that range, including the endpoints (e.g., 2 to 8 includes 2, 2.1, 2.8, 5.3, 7, 8, etc.).

[0167] It will be appreciated that the figures shown and described are not necessarily drawn to scale and that they are provided for ease of reference and understanding and for the relative positioning of structures.

[0168] Headings used herein are provided as suggested under 37 CFR 1.77 or to otherwise provide organizational cues. These headings should not be viewed as limiting or characterizing the invention, which is set forth in any claims that may issue from this disclosure. By way of illustration, a description of a technology in the "Background" is not an admission that the technology is prior art to any invention in this disclosure. Neither the "Summary" nor the "Abstract" should be construed as a characterization of the invention, which is set forth in the issued claims.

[0169] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices. Thus, aspects have been described with reference to various specific preferred embodiments and techniques. However, it will be understood that many changes and modifications can be made while remaining within the spirit and scope of the present disclosure.

[0170] Although many different embodiments of the catheter system are shown and described herein, it is understood that one or more features of any one embodiment may be combined with one or more features of one or more other embodiments, provided that such combinations satisfy the intent of the invention.

[0171] Although a number of exemplary aspects and embodiments of the catheter system have been discussed above, those skilled in the art will recognize certain modifications, permutations, additions and subcombinations thereto. Accordingly, the following appended claims, and any claims thereafter introduced, are intended to be construed to include all such modifications, permutations, additions and subcombinations within their true spirit and scope, and are not intended to limit the details of construction or design herein shown.

Claims

1. 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, comprising: an inflatable balloon; an optical fiber having (i) a fiber proximal end and (ii) a fiber distal end located within the inflatable balloon, the optical fiber configured to receive an energy pulse such that the optical fiber emits light energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, the optical fiber including a tapered portion between the fiber proximal end and the fiber distal end, the tapered portion being spaced from the fiber distal end; an energy source in optical communication with the fiber proximal end of the optical fiber; A catheter system having:

2. The catheter system of claim 1 , wherein the optical fiber includes a first fiber member and a second fiber member coupled to the first fiber member.

3. The catheter system of claim 2 , wherein at least a portion of the second fiber member is disposed within the inflatable balloon.

4. 4. The catheter system of claim 2, wherein the first fiber member is fused to the second fiber member at a fused region.

5. The catheter system of claim 4, wherein the fused region is external to the inflatable balloon.

6. A catheter system described in any one of claims 4 to 5, further comprising a ferrule surrounding the fused region.

7. The catheter system of claim 6, wherein the ferrule is formed from one of plastic and metal.

8. A catheter system described in any one of claims 6 to 7, wherein the ferrule is configured to surround only the optical fiber.

9. A catheter system as described in any one of claims 6 to 8, wherein the ferrule is one of a multi-fiber MT ferrule and an MTP ferrule.

10. The catheter system of claim 2 , wherein the first fiber member and the second fiber member are formed as a unitary structure.

11. 11. The catheter system of claim 2, wherein the first fiber member has a first fiber member distal region disposed outside the inflatable balloon.

12. 12. The catheter system of claim 2, wherein the second fiber member has a second fiber member proximal region disposed outside the inflatable balloon.

13. A catheter system as described in any one of claims 2 to 12, wherein the first fiber member includes an end cap.

14. The catheter system of claim 1 , wherein the energy source comprises a laser.

15. 15. The catheter system of claim 1, wherein the optical fiber is tapered from a diameter of at least 150 micrometers (μm) to a diameter of less than 120 micrometers (μm).

16. 16. The catheter system of claim 1, wherein the taper has a taper length that is at least 2 millimeters (mm).

17. 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, comprising: an inflatable balloon; an optical fiber having (i) a fiber proximal end and (ii) a fiber distal end located within the inflatable balloon, the optical fiber configured to receive an energy pulse such that the optical fiber emits light energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, the optical fiber having a first fiber member, a second fiber member, a fused region where the first fiber member is fused to the second fiber member whereby the second fiber member extends distally from the first fiber member, and a ferrule surrounding at least the fused region; a laser in optical communication with the fiber proximal end of the optical fiber; A catheter system having:

18. The catheter system of claim 17, wherein the fused region is external to the inflatable balloon.

19. 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, comprising: an inflatable balloon; an optical fiber configured to receive an energy pulse, whereby the optical fiber emits light energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, the optical fiber having: (i) a first fiber member having a first fiber member distal region; (ii) a second fiber member having a second fiber member proximal region; (iii) a fused region where the first fiber member distal region is fused to the second fiber member proximal region, whereby the second fiber member extends distally from the first fiber member; and (iv) a ferrule surrounding at least the fused region; A catheter system comprising:

20. The catheter system of claim 19, wherein the fused region is external to the inflatable balloon.

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