Optical assembly for improving energy coupling to the pressure wave generator of an intravascular lithotripsy device

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 the priority of U.S. Provisional Application No. 63 / 148,133, filed on February 10, 2021, and U.S. Patent Application No. 17 / 666,172, filed on 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 hereby incorporated by reference in their entirety.

Background Art

[0002] Vascular lesions within and adjacent to blood vessels in the body can be associated with an increased risk of major adverse events such as myocardial infarction, embolism, deep vein thrombosis, pulsation, and so on. Severe vascular lesions can be difficult for physicians in the clinical setting to treat and achieve patency.

[0003] Vascular lesions can be treated using interventions such as, to name a few, drug therapy, balloon angioplasty, atherectomy, stent placement, vascular tissue transplant bypass, etc. Such interventions may not always be ideal in some cases or may require continuous treatment to address the lesion in some cases.

[0004] Generating high-pressure impulses in a lesion using the optical fiber delivery of laser pulses is one way of attempting to treat the lesion. The generation of plasma via the optical breakdown of an aqueous solution typically requires a significant amount of energy in a short period of time during which the energy is converted into treatment bubbles and / or treatment pressure waves.

Summary of the Invention

[0005] The present invention relates to a catheter system for treating treatment sites within or adjacent to the walls of blood vessels or heart valves. The catheter system comprises an inflatable balloon, an optical fiber, and an energy source. In certain embodiments, the optical fiber has (i) a proximal end and (ii) a distal end positioned within the inflatable balloon. The optical fiber can be configured to receive energy pulses, thereby causing the optical fiber to emit light energy away from the optical fiber, generating a plasma pulse within the inflatable balloon, and the optical fiber tapering from the proximal end to the distal end. The energy source can communicate optically with the proximal end of the optical fiber.

[0006] In various embodiments, optical fibers can be tapered using a fusion splicer.

[0007] In certain embodiments, optical fibers can be joined using core-matched fibers.

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

[0009] In various embodiments, the optical fiber can be divided so that only the second fiber member can be placed inside the inflatable balloon.

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

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

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

[0013] In certain embodiments, the first fiber member can be fused to the second fiber member in the fusion 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 formed integrally with each other.

[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 may have a distal region of the first fiber member that is outside the inflatable balloon.

[0018] In various embodiments, the second fiber member may have a proximal region of the second fiber member that is outside the inflatable balloon.

[0019] In certain embodiments, the distal region of the first fiber member can be fused to the proximal region of the second fiber member in the fusion region.

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

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

[0022] In certain embodiments, the catheter system may include ferrules surrounding the first proximal end of the first optical fiber and the first distal end of the second optical 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 can have an LC ferrule with an outer diameter of 1.25 mm.

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

[0026] In some embodiments, the ferrule can be formed by one of plastic and metal.

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

[0028] In a particular embodiment, the ferrule can be configured for a plurality of fiber members.

[0029] In some embodiments, the ferrule can 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 member.

[0031] In a particular embodiment, the optical fiber can be cleaved (split) 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 the cleavage plane to form a curved ball surface.

[0033] In various embodiments, the optical fiber can be tapered by rotation.

[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 joined joint, and a bare fiber.

[0036] In various embodiments, at least one of tapered fibers, joined joints, and bare fibers is enclosed inside the ferrule with epoxy.

[0037] In certain embodiments, epoxy may be ND353 surrounding the fiber connector for polishing.

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

[0039] In various embodiments, optical fibers 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 the light energy traveling through the first fiber member into the second fiber member.

[0041] In some embodiments, the first fiber member may 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 so that it has a larger diameter at the proximal end and a smaller diameter at the distal end.

[0044] Furthermore, the present invention also covers methods for manufacturing catheter systems.

[0045] The present invention further relates to a method for treating a treatment site in or adjacent to a blood vessel wall or a heart valve. The method may include the steps of: positioning an optical fiber having (i) a proximal fiber end and (ii) a distal fiber end placed in an inflatable balloon, wherein the optical fiber is configured to receive an energy pulse, thereby causing the optical fiber to emit light energy away from the optical fiber and generate a plasma pulse in the inflatable balloon; and coupling an energy source to the proximal fiber end of the optical fiber, wherein the energy source is coupled to the optical fiber to make optical contact.

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

[0047] In various embodiments, the method may include the step of joining optical fibers using core-matched fibers.

[0048] In certain embodiments, the method may include the step of surrounding the fusion region with a ferrule.

[0049] In some embodiments, the method may include the step of using ferrules to surround the first distal fiber end of the first fiber member and the second proximal fiber end of the second fiber member.

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

[0051] The present invention also relates to a catheter system comprising an inflatable balloon, an optical fiber, an energy source, and a splice region. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may include a first fiber member and a second fiber member. The energy source may be in optical communication with the proximal fiber end of the optical fiber. The first fiber member may have a splice region where it is fused to the second fiber member.

[0052] The present invention further relates to a catheter system comprising an inflatable balloon, an optical fiber, an energy source, and a splice region. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may have a first fiber member and a second fiber member comprising a plurality of second fiber member legs. The energy source can be in optical communication with the proximal fiber end of the optical fiber. A splice region may be provided where the first fiber member is fused to the second fiber member. The splice region may be configured to divide the light energy moving through the first fiber member into the second fiber member so that the light energy is divided among the plurality of second fiber member legs.

[0053] The present invention also relates to a catheter system comprising an inflatable balloon, an optical fiber, an energy source, a splice region, and a capillary. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby causing the optical fiber to emit light energy away from the optical fiber, generating plasma pulses within the inflatable balloon. The optical fiber may have a first fiber member and a second fiber member comprising a plurality of second fiber member legs. The energy source can be in optical communication with the proximal fiber end of the optical fiber. A splice region may be provided where the first fiber member is fused to the second fiber member. The splice region may be configured to divide the light energy moving through the first fiber member into the second fiber member so that the light energy is divided among the plurality of second fiber member legs. A capillary may substantially surround the splice region.

[0054] The present invention further relates to a catheter system comprising an inflatable balloon, an optical fiber, a splice region, and a ferrule. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may include an end cap and a first distal fiber end located within the inflatable balloon. The optical fiber may have a first fiber member and a second fiber member. A splice region may be provided where the first fiber member is fused to the second fiber member. The ferrule may substantially surround the splice region.

[0055] The present invention also relates to a catheter system comprising an inflatable balloon, an optical fiber, an energy source, a splice region, and a ferrule. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may include a first fiber member and a second fiber member. The energy source may be in optical communication with the proximal fiber end of the optical fiber. The first fiber member may have a splice region where it is fused to the second fiber member. The ferrule may substantially surround the first fiber member and the splice region.

[0056] The present invention further relates to a catheter system comprising an inflatable balloon and an optical fiber. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end positioned within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy toward the distal fiber end to generate plasma pulses within the inflatable balloon. The optical fiber may have a larger diameter at the proximal fiber end and may be tapered to have a smaller diameter at the distal fiber end.

[0057] The present invention also relates to a catheter system comprising an inflatable balloon and an optical fiber. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may be tapered from the proximal fiber end to the distal fiber end. An energy source can be optically connected to the proximal fiber end of the optical fiber.

[0058] The present invention further relates to a catheter system comprising an inflatable balloon and an optical fiber. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon. The optical fiber may be configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon. The optical fiber may be divided into a plurality of fiber members located within the inflatable balloon. An energy source can be optically connected to the proximal fiber end of the optical fiber.

[0059] In various embodiments, optical fibers 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 having 90% to 10% of the initial diameter.

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

[0062] The present invention also relates to catheter systems for treating treatment sites within or adjacent to the walls of blood vessels or heart valves. The catheter system may include an inflatable balloon, an optical fiber, an energy source, a first tapered portion, a second tapered portion, a first splice region, a second splice region, and a ferrule. The optical fiber may have (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon, and the optical fiber is configured to receive an energy pulse, thereby emitting light energy away from the optical fiber to generate a plasma pulse within the inflatable balloon, and the optical fiber has a first fiber member, a second fiber member and a third fiber member. The energy source can optically communicate with the proximal fiber end of the optical fiber. The first tapered portion may be located on the first fiber member. The second tapered portion may be located on the second fiber member. A first splice region where the first fiber member is fused to the second fiber member. A second splice region may exist in which the second fiber member is fused to the third fiber member. The ferrule can substantially surround the first fiber member and the first splice region.

[0063] This summary outlines some of the teachings of this application and is not intended to be an exclusive or exhaustive treatment of the subject matter. Further details are found in the modes for carrying out the invention and the appended claims. Other modes will be apparent to those skilled in the art upon reading and understanding the following modes for carrying out the invention and upon viewing the drawings that constitute part of the modes for carrying out the invention, and each of these drawings should not be taken in a restrictive sense. The scope herein is defined by the appended claims and their lawful equivalents.

[0064] The novel features of the present invention, as well as the invention itself, are best understood from the accompanying drawings, which are interpreted in relation to the accompanying description, with respect to their structure and operation, where similar reference letters in the accompanying drawings represent similar parts. [Brief explanation of the drawing]

[0065] [Figure 1] This is a substantially cross-sectional view of one embodiment of a catheter system having the features of the present invention. [Figure 2] This is a substantially cross-sectional view of one embodiment of a catheter system including an optical fiber, coupled optics, and an energy source. [Figure 3A] This is a substantially cross-sectional view of one embodiment of a catheter system, including an example of an optical fiber. [Figure 3B] This is a roughly cross-sectional view of another embodiment of another optical fiber for use in a catheter system. [Figure 3AA] This is a cross-sectional view of the optical fiber taken along line 3AA-3AA in Figure 3A. [Figure 3BB] Figure 3B is a cross-sectional view of an optical fiber taken along the line 3BB-3BB. [Figure 4A] This is a schematic cross-sectional view of another embodiment of a catheter system, including an embodiment of an optical fiber, coupled optics, and an energy source. [Figure 4B] This is a schematic cross-sectional view of another embodiment of a catheter system, including another embodiment of optical fiber, coupled optics, and energy source. [Modes for carrying out the invention]

[0066] Various modifications and alternative forms are possible in the embodiments, the details of which are shown and described in detail by example and drawings. However, it should be understood that the scope of this specification is not limited to the specific embodiments described. Rather, it is intended to encompass modifications, equivalents, and alternatives that fall within the spirit and scope of this specification.

[0067] Treatment of vascular lesions can reduce major adverse events or mortality 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 may include, but are not limited to, major adverse cardiac events, major adverse events of the peripheral or central vascular system, major adverse events of the brain, major adverse events of muscle tissue, or major adverse events of any visceral system.

[0068] As used herein, the treatment site may include vascular lesions, such as calcified or fibrous vascular lesions typically found in blood vessels and / or heart valves (hereinafter sometimes simply referred to as "lesion" or "treatment site"). Plasma formation can generate pressure waves and can also result in the rapid formation of one or more bubbles that rapidly expand to their maximum size and then dissipate via cavitation events, which, upon collapse, also produce pressure waves. The rapid expansion of plasma-induced bubbles can generate one or more pressure waves within the balloon fluid, thereby imparting pressure waves to the treatment site. The pressure waves can transmit mechanical energy to the treatment site through the incompressible balloon fluid, imparting a fragmentation force to the lesion. Without wishing to be bound by any particular theory, it is assumed that rapid changes in balloon fluid momentum at the balloon wall of an inflatable balloon in contact with or located near a lesion are transmitted to the lesion and induce fragmentation of the lesion.

[0069] Those skilled in the art will recognize that the following detailed description of the invention is merely illustrative and not intended to be limiting in any way. Other embodiments of the invention will readily come to mind for such skilled persons who benefit from this disclosure. Furthermore, other methods of delivering energy to the lesion may be utilized, including, but are not limited to, current-induced plasma generation. Hereinafter, embodiments of the invention shown in the accompanying drawings will be referenced in detail.

[0070] For the sake of clarity, not all of the defining features of the embodiments described herein are necessarily shown or described. Naturally, it will be recognized that in the development of all such actual embodiments, many embodiment-specific decisions must be made to achieve the developer's specific objectives, such as compliance with application-related and business-related constraints, and that these specific objectives may vary from embodiment to embodiment and from developer to developer. Furthermore, it will be recognized that such development efforts, while sometimes complex and time-consuming, can nevertheless be considered standard engineering work for those skilled in the art who benefit from this disclosure.

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

[0072] It is recognized that the catheter systems described herein may include many different forms and / or configurations other than those specifically shown and / or described herein. Referring here to Figure 1, schematic cross-sectional views of catheter systems according to various embodiments described herein are shown. Catheter system 100 is suitable for applying pressure to induce fragmentation in the vascular walls of blood vessels and / or in or adjacent to vascular lesions within heart valves. In the embodiment shown in Figure 1, catheter system 100 may include one or more of the following: catheter 102, one or more optical fibers 122, controller 123, energy source 124, manifold 136, fluid pump 138, and multiplexer (not shown).

[0073] The catheter 102 includes an inflatable balloon 104 (sometimes referred to as the “balloon” in this specification). The catheter 102 is configured to move into or adjacent to a treatment site 106 within a blood vessel 108. The treatment site 106 may include vascular lesions, such as calcified vascular lesions. In addition or by alternative means, the treatment site 106 may also include vascular lesions, such as fibrous vascular lesions.

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

[0075] The balloon 104 may include a balloon wall 130. The balloon 104 can be deployed from a disintegrating configuration suitable for advancing at least a portion of the catheter shaft 102 through the patient's vascular system to a deployable configuration suitable for securing the catheter 102 in place relative to the treatment site 106.

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

[0077] The optical fiber 122 may vary depending on the design requirements of the catheter system 100 and / or 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. In addition or by alternative means, 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 located in or adjacent to the energy source 124, and a fiber distal end 122D which can be located inside 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 contact with the energy source 124. It is recognized that the optical fiber 122 can be replaced with any suitable optical carrier (the optical fiber 122 is the optical carrier) and / or any suitable energy source configured to carry one or more sub-millisecond energy pulses.

[0079] The controller 123 can control the energy source 124 so that the energy source 124 can generate one or more energy pulses, as will be provided in more detail herein. The controller 123 can also perform any other relevant functions for 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 sent 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 also referred to herein as “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. Each seed source 126 can emit a relatively low-power seed pulse that is received and amplified by the amplifier 128. The amplifier 128 can increase the output of the seed pulse to generate an energy pulse. In one embodiment, the laser 124 can include one seed source 126 and one amplifier 128.

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

[0082] The light energy generated by the energy pulse is delivered to a location within the balloon 104 by the optical fiber 122. The light energy induces plasma formation in the form of a plasma pulse 134 in the balloon fluid 132 within the balloon 104. The plasma pulse 134 results in rapid bubble formation, which imparts a pressure wave to the treatment site 106. An exemplary plasma pulse 134 is shown in Figure 1. The balloon fluid 132 may be a liquid or a gas. As provided in more detail herein, the plasma-induced bubbles 134 are deliberately formed at a distance from the optical fiber 122 to minimize the possibility of damage to the optical fiber.

[0083] In various embodiments, sub-millisecond light pulses with frequencies ranging from at least approximately 1 Hz to a maximum of approximately 5000 Hz can be delivered near the treatment site 106. In some embodiments, sub-millisecond light pulses with frequencies ranging from at least 30 Hz to 1000 Hz can be delivered near the treatment site 106. In other embodiments, sub-millisecond light pulses with frequencies ranging from at least 10 Hz to 100 Hz can be delivered near the treatment site 106. In yet another embodiment, sub-millisecond light pulses with frequencies ranging from at least 1 Hz to 30 Hz can be delivered near the treatment site 106.

[0084] It is recognized that the catheter system 100 described herein may include any number of optical fibers 122 that make optical contact with a laser 124 at a proximal portion 114 and with the balloon fluid 132 in the balloon 104 at a distal portion 116. For example, in some embodiments, the catheter system 100 described herein may include 1 to 30 optical fibers 122. In some embodiments, the catheter system 100 described herein may include 31 or more optical fibers.

[0085] The manifold 136 may be positioned at or near the proximal end 114 of the shaft. The manifold 136 may include one or more proximal end openings that can receive one or more optical fibers, such as optical fiber 122, a guidewire 112, and / or an inflatable conduit 140. The catheter system 100 may 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) connects a single energy source to one or more of several optical channels in a tightly controlled manner. This method allows a single energy source to be sequentially channeled through a variable number of channels.

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

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

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

[0090] The coupled optics 242 couples energy pulses to the optical fiber 222 and redirects their direction toward the optical fiber 222. The coupled 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 coupled optics 242 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. In addition or by alternative means, the coupled optics 242 may omit one or more of the systems, subsystems, and elements specifically shown and / or described herein. The coupled optics 242 may include a reflector 244 and a lens 246. The reflector 244 can reflect energy pulses toward the lens 246. The lens 246 can focus energy pulses so that the optical fiber 222 can receive energy pulses of an appropriate diameter and / or size.

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

[0092] The ferrule 248 can organize and align optical carriers (e.g., optical fiber 222) with respect to the coupled optics 242 in a multiplexer (not shown). The ferrule 248 may vary depending on the design requirements of the catheter system 100, optical fiber 222, and / or laser 224. It is understood that the ferrule 248 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. In addition or alternatively, the ferrule 248 may 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. Alternatively, the ferrule 248 can function as a connector and / or mechanical joint in the catheter system 199. The ferrule 248 can substantially surround any portion of the optical fiber 222.

[0094] In certain embodiments, the systems and methods described herein may include segmented optical carriers (e.g., optical fiber 222) whose diameter is larger at the proximal end of the fiber and taperes to a smaller diameter towards the distal end of the fiber. Alternatively, the optical carriers may have a larger diameter at the distal end of the fiber and taperes to a smaller diameter at the proximal end of the fiber.

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

[0096] The first fiber member 250 may be configured to be fixed to the ferrule 248. The first fiber member 250 may be a segment of the optical fiber 222 that is proximal to the laser 224 and the coupled optics 242. The first fiber member 250 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 first fiber member 250 may include additional systems, subsystems, components and elements other than those specifically shown and / or described herein. In addition or alternatively, the first fiber member 250 may 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 may include a first tapered portion 252. In other embodiments, the first fiber member 250 may be individually attached to or coupled to the tapered portion 252. The first fiber member 250 may be tapered and / or modified to have a modified shape. The first fiber member 250 may be an individual fiber or fiber member attached to the tapered portion 252 and / or the second fiber member 258.

[0098] The tapered portion 252 allows the optical fiber 222 to have a smaller diameter in its distal portion (e.g., the second fiber member 258). The tapered portion 252 can be varied according to the design requirements of the catheter system 100, the optical fiber 222, and / or the laser 224. The shape, tapering, and / or dimensions of the tapered portion 252 can also be changed. The tapered portion 252 can have a tapered portion length 254. The tapered portion length 254 can have a variable length according to 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 is variable. In some embodiments, the tapered portion 252 is located very close to the coupled optics 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 at any location along the optical fiber 222. In some embodiments, the optical fiber 222 may include multiple tapered portions 252 located along the variable location of the optical fiber 222. It is recognized that the optical fiber 222 may 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 splice region 256 can be formed by fusing the first fiber member 250 with the second fiber member 258. The splice region 256 can integrally bond fibers and / or fiber members of different diameters. In some embodiments, the splice region 256 can be fused around a split and / or joint portion (shown in Figures 3AA and 3BB) of the optical fiber 222 so that two separate portions of the optical fiber 222 can be joined.

[0101] The splice 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 dimensions of the splice region 256 can also be modified. The location of the splice region 256 on the optical fiber 222 can be modified. In some embodiments, the splice region 256 is located very close to the coupled optics 242. In other embodiments, the splice region 256 is located closer to the balloon 104. It is recognized that the splice region 256 can be located at any location along the optical fiber 222.

[0102] The second fiber member 258 may be substantially the same as 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 coupled optics 242. The second fiber member 258 can make optical contact with the emitter 260.

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

[0104] While a first fiber member 250 and a second fiber member 258 are described herein, it is recognized that the optical fiber 222 may contain any number of fiber members. In some embodiments, the optical fiber 222 may contain up to 50 fiber members. In other embodiments, the first fiber member 250 having a first tapered portion (not shown) may be fused to a second fiber member 258 having a second tapered portion (not shown) which may be fused to a third fiber member (not shown). The optical fiber 222 may contain any number of fiber members, each having any number of tapered portions individually, and each having any number of fusion sections and / or other attachment points individually.

[0105] The emitter 260 can be driven by an energy source. The emitter 260 may also be a plasma generator. The optical fiber 222 can contain one or more emitters 260. The emitter 260 can be positioned at any location along the portion of the optical fiber 222 that is located inside the balloon 104. The emitter 260 can provide one or more plasma pulses 134.

[0106] The emitter 260 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 emitter 260 may include additional systems, subsystems, components, and elements other than those specifically shown and / or described herein. In addition or alternatively, the 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 (for example, tapering optical fiber 222) involves the steps of heating, drawing, and then cleaving the larger proximal section to taper it at the smaller end. An optical carrier assembly can then be formed by fusing the smaller diameter end to a smaller diameter carrier for the distal section. Optical carriers can be fused using fusion joints.

[0108] Another embodiment of the tapering method may include the steps of continuously heating and drawing a proximal section to produce a longer optical carrier having a smaller diameter for the distal section. The tapering method may include the steps of creating a short tapered portion 252 and fusing the larger and smaller ends to a matched diameter optical carrier. This embodiment may require two fusion joints.

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

[0110] The large diameter of the proximal surface can reduce the precision required to form a coupled optical energy beam and align the coupled optics 242 with the optical guide (e.g., optical fiber 222). This design can reduce the multiplexer precision requirements and the optics-mechanical tolerances for connectorizing the optical carriers. The tapered portion 252 conserves energy pulses and transmits them to smaller diameter carriers with minimal loss.

[0111] In certain embodiments, etendue is maintained within the optical guide. Maintaining etendue requires keeping the product of numerical aperture (NA) and diameter constant. Therefore, the NA of the tapered distal section is NA d =(D p / D d )NA p It must be made larger in this way. For example, 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 smaller diameter end of the tapered section is fused to an optical guide with a similar NA=0.22, it 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 fiber 222 described herein is 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 more than 1mm, to less than 1μm, 1μm, 5μm, 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 The optical fibers and / or optical carriers shown and / or described herein can be tapered to final diameters of 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, and 900 μm. The optical fibers and / or optical carriers shown and / or described herein can be tapered to have final and initial diameters that fall within a certain range, and all of the above figures can act as lower or upper boundaries of that range, provided that the lower boundary of that range is less than the upper boundary of that range. The optical fibers and / or optical carriers described herein can have final and initial diameters that fall outside the ranges described herein.

[0113] One way to avoid coupling loss is to use optical carriers with a smaller NA on the proximal end of the fiber, which has a larger diameter, and optical carriers with an NA that is proportionally larger in diameter for the smaller distal section. p From D d The tapering process up to this point results in the numerical apertures of the two sections matching. In some embodiments, a tapered portion 252 can be formed to bring about an adiabatic change in optical curvature, and the resulting NA minimizes loss through the transition.

[0114] Stimulated Brillouin scattering (SBS) is a nonlinear process in optical carriers that can limit total energy transmission. In SBS, an intense beam of light energy interacts with sound waves in a medium, potentially resulting in a weak reflected beam. The reflected beam is commonly called a Stokes wave, and the original beam can then interfere, amplifying the sound wave through electrical strain. The power in the reflected beam can be increased nonlinearly using the input beam power. As a result, the energy throughput can be continuously reduced using the input power, effectively clamping the peak transmission power and thereby significantly limiting the emitter's conversion efficiency and output.

[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 the optical guide quadruples the power threshold for initiating SBS. SBS occurs in the region of the optical guide closer to the emission end. If this can be avoided in larger carriers, all the power emitted in the carriers can be coupled into smaller optical carriers. By increasing the diameter of the proximal section, significantly more power can be coupled into the optical guide assembly and transmitted to the distal end of the fiber.

[0116] In some embodiments, the proximal optical carrier may be a doped optical fiber that improves transmission characteristics and further suppresses the onset of SBS. Some examples of suitable dopants are GeO2, P2O3, TiO2, B2O3, F2, and A1203. Doped fibers can be significantly more expensive per unit length than conventional pure silica fibers.

[0117] This method allows for the suppression of short-circuit breaks (SBS) by using shorter, more expensive fibers in a much longer assembly made of lower-cost fibers. Another method allows for the implementation of shorter photonic crystal fibers, hollow-core fibers, chiral fibers, or similar structured optical fibers in the proximal section and conventional pure silica glass fibers through a longer catheter system 100. This configuration allows for a lower-cost distal section and the use of shorter, more expensive fibers in the proximal section while achieving similar results.

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

[0119] The optical fiber 322 may 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 into a single proximal carrier. The distal carrier may have the same diameter as the diameter used for the proximal section, or it may have a smaller diameter. In other embodiments, the distal section has N optical carriers with a smaller diameter than the proximal section.

[0120] The total end face area of ​​the distal section is equal to the total end face area of ​​the proximal section.

number

[0121] One advantage of the embodiment shown in Figure 3A is that, when simultaneously supplying power to two emitters 260, it eliminates the need to split the energy source into two separate beams and couple each of those beams into individual optical carriers. This embodiment can have another advantage: it simplifies the multiplexer architecture and optics. Furthermore, the embodiment shown in Figure 3A can also reduce losses due to having two separate beam paths and individual Fresnel losses occurring at the end faces of the two optical carriers.

[0122] While significant losses can exist in fusion splicers (e.g., fusion region 356), these losses can be comparable to those in 2-leg multiplexer architectures with complex coupling optics. Fusion splicers can simplify multiplexer architectures, reduce alignment tolerances, enable simpler optics with improved transmission, and eliminate losses associated with splitting the optical and emission interfaces.

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

[0124] Individual capillaries 364 can be placed around a fusion assembly (e.g., a fusion region 356) and fused together to optimize cross-sectional and area matching. This technique can be used to improve coupling efficiency for any number of carriers in the splitter. Capillaries 364 can be stretched to tight tolerances and may be well-suited for use in the catheter system 100. Capillaries 364 may vary depending on the design requirements of the catheter system 100 and / or the optical fiber 322. It is understood that capillaries 364 may include additional systems, subsystems, components and elements other than those specifically shown and / or described herein. Additionally or alternatively, capillaries 364 may 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 along the line 3AA-3AA in Figure 3A. As shown in Figure 3AA, this cross-sectional view demonstrates that the splice region 356 can include the first fiber member 350 and the second fiber member legs 362A-C. The first fiber member 350 can be fused to the second fiber member legs 362A-C at different locations such that the outer peripheral portion of the first fiber member 350 is fused to the outer peripheral portions of the second fiber legs 362A, 362B, and 362C.

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

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

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

[0129] The example shown in Figure 4A illustrates a direct approach to improve coupling to smaller photocarriers using an end cap 466A fused to the proximal end. Generally, the damage threshold for photomaterials is much lower at air interfaces than in bulk materials, sometimes by an order of magnitude.

[0130] This technique 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 close to the bulk threshold for the forming material. According to this embodiment, a significantly large amount of energy can be coupled into optical carriers of a small diameter. The converging incident beam can be precisely centered on the end cap 466A and also precisely aligned within the ferrule 448A to achieve alignment for optimal coupling. In certain embodiments, precise alignment is required to center the converging incident beam on the end cap 466A.

[0131] Figure 4B is a schematic cross-sectional view of another embodiment of an optical fiber 422B, a coupled optics 442B, and an energy source (e.g., laser 424B) for use in a catheter system 100 (shown in Figure 1). The embodiment shown in Figure 4B features a tapered assembly. The tapered optical carrier may be a short section (e.g., tapered portion 452B) confined within a ferrule 456B. This technique 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 in Figure 4B can reduce the requirement to align with smaller optical carriers via optical energy guidance through the tapered portion 452B.

[0132] The present invention also relates to a method for treating a treatment site 106 (shown in Figure 1) within or adjacent to a vascular wall or a heart valve using such a method utilizing the device disclosed herein.

[0133] fiber The optical fibers suitable for use in this specification may include various types of fibers suitable for optical communication with energy sources such as lasers and lamps. In some embodiments, the optical fiber may include fiber connectors and fiber tapers. Fiber tapers can be implemented using solid metal tubes with a length of several tens of millimeters. 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 joining can be an effective method for minimizing insertion loss. In certain embodiments, the fiber taper can be integrated into a fiber connector, and the fiber taper can also 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 polished ferrules. Fibers can be enclosed within the fiber connector with epoxy. Dozens of different styles of fiber connectors exist, including ferrules with an outer diameter of 1.25 mm LC and 2.5 mm SC. The inner diameter of the ferrule is determined by the fiber size, and is sometimes between 126 and 127 μm for single-mode fibers.

[0135] In some examples, the ferrules described herein are 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, 3 It can have diameters (both inner and outer) of 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. Ferrules shown and / or described herein may have diameters (both inner and outer) that fall within a certain range, and all of the above figures may act as the lower or upper boundary of that range, provided that the lower boundary of that range is less than the upper boundary of that range. Ferrules described herein may have diameters (both inner and outer) that fall outside the range described herein.

[0136] In high-power laser fiber coupling, using a large-diameter core fiber can reduce the power density at the fiber coupling surface, thereby strengthening the damage threshold. However, large-diameter fibers are inflexible 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 crucial. Connecting or joining a large-core fiber to a small-core fiber can directly lead to unacceptable insertion loss.

[0137] One embodiment of a method for converting optical power includes the steps of tapering a larger diameter core fiber to match a smaller diameter core fiber, and then joining the fiber taper to the smaller core fiber. However, the fiber taper and joint must be well-implemented, and metal conduits with a diameter of 3 mm and a length of 50 mm are typically extremely impractical in many applications.

[0138] By integrating a fiber connector with a fiber taper, a new type of fiber connector, the tapered fiber connector, is created. This type of fiber connector has a fixed size, but the fiber taper is surrounded by epoxy. Because the lateral offset does not introduce any significant loss, any suitable type of fiber connector, including all-unimode fiber connectors, can be modified into a tapered fiber connector for receiving light.

[0139] In various embodiments, a fusion splicer can taper a fiber and bond the fiber taper onto a smaller core fiber. In other embodiments, other devices and methods can be used to taper a fiber and bond the fiber taper onto a smaller core fiber. A fiber can be tapered by heating the central section of the fiber, held under tension, using a hydrogen flame. A fiber can also be tapered using devices and methods known in the art.

[0140] Fiber tapers and joints can be encased in epoxy within fiber ferrules for polishing. Epoxys that can be used herein include thermal epoxy, room-temperature curing epoxy (such as ND353), UV-curing epoxy (such as LOCTITE® 4310 UV adhesive), and other suitable epoxys known in the art. The process 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 on the fiber surface is low. Since the end cap glass is equivalent to free space rather than a waveguide, the fiber end cap may require precise alignment. However, the fiber taper can still function as a waveguide and therefore does not require alignment.

[0141] In some embodiments, fibers with a core / cladding diameter of 200 / 220 μm are selected to couple a high-power laser, and when catheters for medical treatment are constructed using fibers with a core / cladding diameter of 105 / 125 μm, the process of converting laser power from a larger diameter core fiber to a smaller diameter core fiber is important.

[0142] For example, if a larger fiber with a core / cladding diameter of 200 / 220 μm is directly bonded onto a smaller fiber with a core / cladding diameter of 105 / 125 μm, most of the light will not couple from the larger fiber into the smaller fiber, resulting in a large insertion loss. As an estimate, the ratio of the two core superpositions is:

number

number

[0143] Simplifying equations 1 and 2,

number

[0144] NA is the numerical aperture of a fiber; for a numerical aperture of 0.22, the maximum incident angle α is 12.7 degrees. In the case of a non-tapered fiber, the angle of light remains constant along the fiber and is emitted at the same angle α. However, in the case of a tapered fiber, the emission angle becomes larger than the incident angle α, depending on the tapering angle and length.

[0145] If the angle of incidence of light is sufficiently small, or if the effective NA of the light beam is significantly smaller than the NA2 of a small fiber with a specific tapering angle and tapering length, the effective NA of the light emitted from the fiber taper is still within the smaller fiber-acceptable angular range of arcsin(NA2), and can be 12.7 degrees for a numerical aperture of 0.22. The tapering angle δ is,

number

[0146] In a particular embodiment, when a parallel free-space laser beam with a diameter of 3 mm is focused by a 50 mm focal lens and coupled to a fiber taper, the numerical aperture (NA) of the incident beam is:

number

[0147] The angle of light increases by 2δ each time it reflects off the surface of the fiber taper, so the pitch between two reflections along the fiber becomes increasingly shorter, while the angle increases. To prevent light leakage from the fiber core to the cladding, the maximum angle of light must not exceed arcsin(NA2).

[0148] When a free-space laser beam with a diameter of 3 mm is focused by a lens with a focal length of 50 mm, if a fiber with a large diameter of 200 μm is tapered into a smaller core of 105 μm (fiber taper 200 / 105 μm), the fiber taper allows all the light to be converted from the large core fiber to the small 105 μm core fiber without any light leaking into the fiber cladding in the tapered region and junction.

[0149] Simulations show that when large diameters of 200 μm, 300 μm, and 400 μm are tapered to a smaller 105 μm core with a tapering length of 5 mm, all light from the larger diameter core fiber can be perfectly coupled to the smaller core fiber, like an optical funnel. Simulations also show that for a 1000 / 105 μm fiber taper with a tapering length of 5 mm, light leaks from the fiber core to the cladding, resulting in significant insertion loss as shown below. Similarly, simulations show that for a 200 / 105 μm fiber taper, the light emission angle relative to the tapering length is curved. Generally, smaller angles or beam sizes are desirable, and therefore the optimal tapering length is at least 4-5 mm.

[0150] In some embodiments, a 500 μm core diameter can be tapered to a smaller 105 μm core for light conversion. However, simulations indicate 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 increased to 15 mm.

[0151] The FSM100P fiber fusion splicer can taper large fibers up to 500 μm to smaller sizes. Compared to 105 / 125 μm fibers for high-power optical coupling, larger diameter fibers can significantly reduce power density. For tapered connectors with fiber tapers of 200 μm, 300, 400 μm, and 500 μm diameters, power density can be reduced to less than one-quarter, one-eighth, one-fifteenth, and one-twenty-second, respectively. Fiber fusion for tapering causes the fiber core to stretch slightly, resulting in a slightly smaller fiber core diameter after tapering. For example, a 200 μm core diameter can be tapered to a core of 95 μm or less to match a 105 / 125 μm fiber.

[0152] In some embodiments, the optical fibers and / or optical carriers described herein are 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 Optical fibers and / or optical carriers shown and / or described herein may have diameters of μm, 320μm, 340μm, 360μm, 380μm, 400μm, 420μm, 440μm, 460μm, 480μm, 500μm, 520μm, 540μm, 560μm, 580μm, 600μm, 620μm, 740μm, 760μm, 780μm, 800μm, 850μm, 900μm, 1mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm or more, or greater than 3.0mm. Optical fibers and / or optical carriers shown and / or described herein may have diameters that fall within a certain range, and all of the above figures may act as lower or upper boundaries of that range, provided that the lower boundary of that range is less than the upper boundary of that range. The optical fibers and / or optical carriers described herein may have diameters outside the ranges described herein.

[0153] In various embodiments, the optical fibers and / or optical carriers described herein may have tapered lengths 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. The optical fibers and / or optical carriers shown and / or described herein may have tapered lengths that fall within a certain range, and all of the above figures may act as the lower or upper boundary of that range, provided that the lower boundary of that range is less than the upper boundary of that range. The optical fibers and / or optical carriers described herein may have tapered lengths that are outside the range described herein.

[0154] laser Suitable lasers for use in this specification can include various types of lasers, including lasers and lamps. Suitable lasers can include short-pulsed lasers with a sub-millisecond timescale. In some embodiments, the laser can include a laser with a nanosecond (ns) timescale. The laser can also include short-pulsed lasers with picosecond (ps), femtosecond (fs), and microsecond (us) timescales. It is recognized that there are many combinations of laser wavelength, pulse width, and energy level that can be used to achieve plasma in the balloon fluid of a catheter as shown and / or described herein. In various embodiments, the pulse width can be in a range including at least 10 ns to 200 ns. In some embodiments, the pulse width can be in a range including at least 20 ns to 100 ns. In other embodiments, the pulse width can be in a range including at least 1 ns to 5000 ns.

[0155] Exemplary nanosecond lasers can include lasers in the UV to IR spectrum, with wavelengths ranging from approximately 10 nanometers to 1 millimeter. In some embodiments, lasers suitable for use in catheter systems as described herein can include lasers capable of producing light with wavelengths from at least 350 nm to 2000 nm. In some embodiments, lasers can include lasers capable of producing light with wavelengths from at least 700 nm to 3000 nm. In some embodiments, lasers can include lasers capable of producing light with wavelengths from at least 100 nm to 10 micrometers (μm). Nanosecond lasers can include lasers having repetition rates up to 200 kHz. In some embodiments, lasers can include Q-switched thulium:yttrium-aluminum-garnet (Tm:YAG) lasers. In some embodiments, the laser may 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 wave The catheters shown and / or described herein are capable of generating pressure waves having a maximum pressure in the range of at least 1 megapascal (MPa) to 100 MPa. The maximum pressure wave generated by a particular catheter will depend on the laser, absorbing material, bubble expansion, propagation medium, balloon material, and other factors. In some embodiments, the catheters shown and / or described herein are capable of generating pressure waves having a maximum pressure in the range of at least 2 MPa to 50 MPa. In other embodiments, the catheters shown and / or described herein are capable of generating pressure waves having a maximum pressure in the range of at least 2 MPa to 30 MPa. In yet another embodiment, the catheters shown and / or described herein are capable of generating pressure waves having a maximum pressure in the range of at least 15 MPa to 25 MPa. In some embodiments, 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 higher. The catheters shown and / or described herein are capable of generating pressure waves having an operating pressure or maximum pressure that falls within a certain range, and all of the above figures can act as lower or upper boundaries of that range, provided that the lower boundary of that range is less than the upper boundary of that range.

[0157] The treatment procedure may act via a fatigue mechanism or a force mechanism. In the case of a fatigue mechanism, the operating pressure will be at least about 0.5 MPa to 2 MPa, or about 1 MPa. In the case of a force mechanism, the operating pressure will be at least about 20 MPa to 30 MPa, or about 25 MPa. The pressure between the local limits of these two ranges may act on the treatment site using a combination of the fatigue mechanism and the force mechanism.

[0158] The pressure waves described herein can be applied to the treatment site from a distance ranging from at least 0.01 mm to 25 mm, extending radially from the longitudinal axis of the catheter placed at the treatment site. In some embodiments, the pressure waves can be applied to the treatment site from a distance ranging from at least 1 mm to 20 mm, extending radially from the longitudinal axis of the catheter placed at the treatment site. In other embodiments, the pressure waves can be applied to the treatment site from a distance ranging from at least 0.1 mm to 10 mm, extending radially from the longitudinal axis of the catheter placed at the treatment site. In yet another embodiment, the pressure waves can be applied to the treatment site from a distance ranging from at least 1.5 mm to 4 mm, extending radially from the longitudinal axis of the catheter placed at the treatment site. In some embodiments, the pressure waves can be applied to the treatment site from a distance ranging from 0.1 mm to 10 mm, ranging from at least 2 MPa to 30 MPa. In some embodiments, the pressure waves can be applied to the treatment site from a distance ranging from 0.1 mm to 10 mm, ranging from at least 2 MPa to 25 MPa. In some embodiments, the pressure wave can be applied to the treatment site from a distance of 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 wave may be applied from a distance that falls within any of the above distances, or from a distance that falls outside of any of the above distances.

[0159] The systems and methods described herein provide improved optical coupling to individual optical carriers organized into a multi-channel array. The advantages of this improved optical coupling are increased damage threshold and coupling efficiency, while reducing the requirements for mechanical tolerances.

[0160] The systems and methods provided herein improve the photodamage threshold and energy throughput while maintaining a small diameter section connected to the plasma generator. The advantages of the improved photodamage threshold and energy throughput are that the mechanical cross-section is minimized and the bending stiffness of the optical guide bundle and catheter is minimized.

[0161] According to the systems and methods provided herein, larger optical carriers can be used in the proximal section of a single-use device (sometimes referred to herein as "SUD"), where larger optical carriers can be easily aligned with the optics to couple the light, while smaller carriers can be used in the distal section to cross profiles and optimize key mechanical properties such as bending stiffness. The advantages of this method are: 1) reducing the requirements for connector tolerances for aligning optical carriers to coupled optics and for mechanical tolerances at those locations in the multiplexer; 2) reducing the system performance dependency on the accuracy of connecting and aligning the multiplexer to the multiplexer; 3) reducing the dependency on the accuracy of the positioning mechanism in the multiplexer and its associated quality and precision of optical and mechanical components; 4) reducing costs by enabling the use of lower-cost, less accurate ferrules on the SUD; 5) increasing the optical damage threshold at the proximal end face of the optical carrier to allow for larger energy to drive the emitter; and 6) reducing the transmission loss in the optical carrier, which increases as the diameter of the optical carrier decreases due to the nonlinear optical process.

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

[0163] The systems and methods described herein reduce the dependence of the multiplexer on the accuracy of the positioning mechanism, its optical components, and the associated quality and accuracy of its mechanical components, thereby improving the speed and performance of the multiplexer and the multiple channel ferrule system.

[0164] The systems and methods described herein increase the damage threshold of the photocarrier and allow for greater energy coupling in and to the photocarrier, while at the same time enabling the use of smaller carriers through critical sections of the catheter.

[0165] It should also be noted that, as used herein and in the appended claims, the phrase “configured” describes a system, apparatus or other structure that is built or configured to perform a particular task or to adopt a characteristic configuration. The phrase “configured” can be used interchangeably with other similar phrases such as “located and configured,” “built and located,” “built, manufactured and located,” and so on.

[0166] As used herein, a numerical range indicated by an endpoint shall include the endpoint and all numbers contained within that range (for example, 2 to 8 includes 2, 2.1, 2.8, 5.3, 7, 8, etc.).

[0167] It should be noted that the diagrams shown and explained are not necessarily drawn to scale, and that they are provided for the purpose of facilitating reference and understanding, and for the relative positioning of structures.

[0168] The headings used herein are provided in accordance with the suggestions under 37 CFR 1.77, or otherwise provided to provide a compilation queuing. These headings should not be viewed as limiting or characterizing the invention as set forth in any claims that may be issued from this disclosure. As an example, the description of the technology in “Background Art” does not constitute an acknowledgment that the technology is prior art to any invention in this disclosure. Neither “Summary of Invention” nor “Abstract” should be construed as characterizing the invention as set forth in any published claims.

[0169] The embodiments described herein are not intended to be exhaustive, nor to limit the invention to the exact forms disclosed in the following detailed description. Rather, the embodiments are selected and described in such a way that those skilled in the art can recognize and understand the principles and practices. Accordingly, embodiments are described with reference to various specific preferred embodiments and techniques. However, it should be understood that many changes and modifications can be made while maintaining the spirit and scope of this specification.

[0170] While many different embodiments of catheter systems 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 combination satisfies the intent of the present invention.

[0171] Having considered numerous exemplary embodiments and examples of catheter systems, those skilled in the art will recognize specific modifications, substitutions, additions, and subcombinations thereof. Therefore, the appended claims below, and any claims introduced later, are intended to be interpreted as encompassing all such modifications, substitutions, additions, and subcombinations in their true spirit and scope, and are not intended to limit the structural or design details shown herein.

Claims

1. A catheter system for treating treatment sites within or adjacent to the blood vessel wall or heart valve, Inflatable balloon and An optical fiber having (i) a proximal fiber end and (ii) a distal fiber end located within the inflatable balloon, wherein the optical fiber is configured to receive energy pulses, thereby emitting light energy away from the optical fiber to generate plasma pulses within the inflatable balloon, and the optical fiber includes a tapered portion between the proximal fiber end and the distal fiber end, the tapered portion being spaced apart from the distal fiber end, The optical fiber has an energy source that is in optical communication with the proximal end of the optical fiber, The catheter system comprises an optical fiber including a first fiber member and a second fiber member fused to the first fiber member in a fusion region, wherein the second fiber member includes a plurality of second fiber legs.

2. The catheter system according to claim 1, further comprising a ferrule surrounding the fusion region.

3. The catheter system according to claim 2, wherein the ferrule is formed of one of plastic and metal.

4. The catheter system according to any one of claims 2 to 3, wherein the ferrule is configured to surround only the optical fiber.

5. The catheter system according to any one of claims 2 to 4, wherein the ferrule is one of a multifiber MT ferrule and an MTP ferrule.

6. The catheter system according to any one of claims 2 to 5, wherein the first fiber member has a distal region of the first fiber member that is located outside the inflatable balloon.

7. The catheter system according to any one of claims 2 to 6, wherein the second fiber member has a proximal region of the second fiber member that is located outside the inflatable balloon.

8. The catheter system according to any one of claims 2 to 7, wherein the first fiber member includes an end cap.

9. The catheter system according to any one of claims 2 to 8, wherein the energy source includes a laser.

10. The catheter system according to any one of claims 2 to 9, wherein the optical fiber is tapered from a diameter of at least 150 micrometers (μm) to a diameter of less than 120 micrometers (μm).

11. The catheter system according to any one of claims 2 to 10, wherein the tapered portion has a tapered portion length of at least 2 millimeters (mm).

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