Optical analyzer components and methods for intravascular lithotripsy devices

Abstract

A catheter system (100) for treating a treatment site (106) within or adjacent to a blood vessel wall (108) or a heart valve includes a light source (124), an expandable balloon (104), a light guide (122A), and an optical analyzer assembly (142). The light source (124) generates light energy. The expandable balloon (104) can be positioned substantially adjacent to the treatment site (106). The expandable balloon (104) has a balloon wall (130) defining an interior (146) of the balloon, the interior of which receives balloon fluid (132). The light guide (122A) receives light energy from the light source (124) at a proximal end (122P) of the guide and directs the light energy in a first direction (121F) toward a distal end (122D) of the guide and into the interior (146) of the balloon. The optical analyzer assembly (142) is configured to optically analyze the light energy emitted from the light guide (122A) in a second direction (121S) from the far end (122D) of the light guide (122A) toward the near end (122P) of the light guide (122A).

Description

[0001] Related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 991,394, filed March 18, 2020, and U.S. Patent Application No. 17 / 172,980, filed February 10, 2021. To the extent permitted, the contents of U.S. Provisional Application No. 62 / 991,394 and U.S. Patent Application No. 17 / 172,980 are incorporated herein by reference in their entirety.

[0003] background

[0004] Vascular lesions within the body's blood vessels may be associated with an increased risk of major adverse events such as myocardial infarction, embolism, deep vein thrombosis, and stroke. For physicians in a clinical setting, severe vascular lesions can be difficult to treat and achieve patency.

[0005] Vascular lesions can be treated with interventions such as medication, balloon angioplasty, atherosclerotic plaque resection, stent placement, and vascular grafting. These interventions may not always be ideal, or may require subsequent treatments to resolve the lesions.

[0006] Overview

[0007] This invention relates to a catheter system for treating treatment sites within or adjacent to the wall of a blood vessel or a heart valve. In various embodiments, the catheter system includes a light source, a balloon, a light guide, and an optical analyzer assembly. The light source generates light energy. The balloon is positioned substantially adjacent to the treatment site. The balloon has a balloon wall defining an interior of the balloon, the interior of which receives balloon fluid. The light guide is configured to receive light energy at its proximal end and to direct the light energy in a first direction from the proximal end of the guide toward a distal end of the guide located within the balloon. The optical analyzer assembly is configured to optically analyze the light energy from the light guide moving in a second direction opposite to the first direction.

[0008] In some embodiments, balloon fluid is supplied to the interior of the balloon, causing the balloon to inflate from a contracted configuration to an inflated configuration.

[0009] Furthermore, in some embodiments, a light source generates light pulses that are guided along a light guide into the balloon to induce plasma generation in the balloon fluid within the balloon. In some such embodiments, the catheter system also includes a plasma generator located distal to the light guide, configured to generate plasma in the balloon fluid within the balloon. Additionally, in these embodiments, plasma generation can lead to rapid bubble formation and the application of pressure waves to the balloon wall near the vascular lesion.

[0010] In such embodiments, the optical analyzer assembly can be configured to optically detect whether plasma generation has occurred in the balloon fluid within the balloon. Furthermore, the optical analyzer assembly can also be configured to optically detect whether insufficient plasma generation has occurred in the balloon fluid within the balloon. Additionally, the optical analyzer assembly can be configured to optically detect faults in the light guide at any point along the length of the light guide from its proximal end to its distal end. In some such embodiments, the optical analyzer assembly can also be configured to optically detect potential damage to the light guide at any point along the length of the light guide from its proximal end to its distal end. Furthermore, in some such embodiments, the optical analyzer assembly is configured to automatically shut down the operation of the conduit system upon optical detection of potential damage to the light guide.

[0011] In some embodiments, the distal end of the guide includes a distal light receiver that receives light energy as a return energy beam traveling from the distal end to the proximal end of the guide through the light guide. In some such embodiments, the light energy received by the light guide from the distal end to the proximal end of the guide is emitted from plasma generated in the balloon fluid inside the balloon. Furthermore, in some such embodiments, the light energy received by the light guide via the distal light receiver from the distal end to the proximal end of the guide is optically analyzed by an optical analyzer assembly.

[0012] In some embodiments, the conduit system further includes a pulse generator coupled to a light source. The pulse generator is configured to trigger the light source to emit a light energy pulse that is guided along the light guide from the proximal end to the distal end of the guide. In such embodiments, the light energy pulse can excite a plasma generator located at the distal end of the light guide, the plasma generator being configured to generate plasma in the balloon fluid inside the balloon. Additionally, in some such embodiments, light energy is guided back as a return energy beam through the light guide to the proximal end of the guide. In such embodiments, an optical analyzer assembly is configured to optically analyze the return energy beam to determine whether plasma generation has occurred in the balloon fluid inside the balloon.

[0013] In some embodiments, the optical analyzer assembly includes a beam splitter and a photodetector. The beam splitter is configured to receive the returned energy beam and guide at least a portion of the returned energy beam to the photodetector. Furthermore, in some embodiments, the duct system also includes an optical element positioned along the beam path between the beam splitter and the photodetector, the optical element being configured to couple at least a portion of the returned energy beam to the photodetector. Additionally, in some embodiments, the photodetector generates a signal based at least partially on visible light contained in at least a portion of the returned energy beam. Furthermore, the signal from the photodetector can be amplified using an amplifier to provide an amplified signal, and this amplified signal can be directed to control electronics to determine the intensity of plasma generation in the balloon fluid inside the balloon. Furthermore, in some embodiments, a discriminator circuit is used to gate the amplified signal. In such embodiments, the control electronics compare the timing of an energy pulse from a light source triggered by a pulse generator with the timing of the amplified signal from the photodetector to determine when plasma generation occurs in the balloon fluid inside the balloon.

[0014] In other embodiments, the conduit system further includes a second light source that generates light energy as an interrogation beam. In these embodiments, the light guide is configured to receive the interrogation beam from the second light source at a proximal end of the guide and to guide the interrogation beam from the second light source toward a distal end of the guide. In some such embodiments, the conduit system further includes a pulse generator coupled to the second light source, configured to trigger the second light source to emit a light energy pulse as an interrogation beam that is guided along the light guide from the proximal end to the distal end of the guide. Additionally, in some such embodiments, the second light source is a visible light source.

[0015] Furthermore, in some embodiments, the conduit system further includes a plasma generator located at the distal end of the optical guide. In such embodiments, the interrogation beam is one of an interrogation beam scattered by the plasma generator and an interrogation beam reflected by the plasma generator, and the interrogation beam is guided along the optical guide as a returning interrogation beam from the distal end to the proximal end of the guide. In some embodiments, the returning interrogation beam emitted from the proximal end of the optical guide is optically analyzed by an optical analyzer assembly. Furthermore, in some embodiments, the optical analyzer assembly includes a beam splitter and a photodetector, and the beam splitter is configured to receive the returning interrogation beam and guide at least a portion of the returning interrogation beam to the photodetector. Furthermore, in some such embodiments, the photodetector generates a signal at least partially based on at least a portion of the returning interrogation beam. Additionally, the signal from the photodetector can be amplified using an amplifier to provide an amplified signal; and the amplified signal can be directed to control electronics to determine when plasma generation occurs in the balloon fluid inside the balloon. Furthermore, a discriminator circuitry can be used to gate the amplified signal. In such an embodiment, the control electronics can compare the timing of a light energy pulse triggered by a pulse generator from a second light source with the timing of an amplified signal from a photodetector to determine when plasma generation occurs in the balloon fluid inside the balloon.

[0016] In some embodiments, the light source includes a laser.

[0017] Additionally, in some embodiments, the light source includes an infrared laser that emits light energy in the form of infrared light pulses.

[0018] In addition, in some embodiments, the light guide includes an optical fiber.

[0019] The present invention also relates to a method for treating a treatment site within or adjacent to the wall of a blood vessel or a heart valve. In some embodiments, the method includes the steps of: generating light energy using a light source; positioning a balloon substantially adjacent to the treatment site, the balloon having a balloon wall defining an interior of the balloon for receiving balloon fluid; receiving the light energy from the light source at a proximal end of a light guide using a light guide; guiding the light energy from the proximal end of the light guide to a distal end of the light guide located inside the balloon in a first direction using the light guide; and optically analyzing the light energy from the light guide using an optical analyzer assembly, wherein the analyzed light energy moves in a second direction opposite to the first direction.

[0020] This overview is a summary of 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 detailed description and the appended claims. Other aspects will become apparent to those skilled in the art upon reading and understanding the following detailed description and examining the accompanying drawings, which form a part thereof, and none of the description and drawings should be construed as limiting. The scope of this document is defined by the appended claims and their legal equivalents. Brief description of the attached diagram

[0022] The novel features of the invention, and the invention itself, will be best understood in conjunction with the accompanying description and with respect to the accompanying drawings, both in terms of its structure and its operation, wherein similar reference characters denote similar parts, and in the drawings:

[0023] Figure 1 This is a schematic cross-sectional view of an embodiment of a catheter system according to various embodiments of the present invention, the catheter system including an optical analyzer assembly having the features of the present invention;

[0024] Figure 2 This is a simplified schematic diagram of a portion of an embodiment of a catheter system, which includes an embodiment of an optical analyzer assembly; and

[0025] Figure 3 This is a simplified schematic diagram of another embodiment of a catheter system, which includes another embodiment of an optical analyzer assembly.

[0026] While embodiments of the invention allow for various modifications and alternative forms, specific details thereof have been shown by way of example and drawings and are described in detail herein. However, it is to be understood that the scope of this document is not limited to the specific embodiments described. Rather, it is intended to cover modifications, equivalents, and alternatives that fall within the spirit and scope of this document.

[0027] describe

[0028] Treatment of vascular lesions (sometimes referred to herein as the “treatment site”) can reduce major adverse events or death in affected subjects. As described herein, a major adverse event is a significant adverse event that can occur anywhere in the body due to the presence of vascular lesions. Major adverse events may include, but are not limited to: major cardiac adverse events, major adverse events of the peripheral or central vascular system, major adverse events of the brain, major adverse events of the muscular system, or major adverse events of any internal organ.

[0029] The catheter systems and related methods disclosed herein are configured to monitor the performance, reliability, and safety of intravascular lithotripsy (IVL) catheters. In various embodiments, the catheter systems of the present invention utilize an energy source, such as a light source (e.g., a laser source or another suitable energy source), which provides energy directed by an energy guide (e.g., a light guide) to generate localized plasma within the balloon fluid inside the expandable balloon of the catheter. Therefore, the energy guide may sometimes be referred to herein as a “plasma generator,” or it may be said that a “plasma generator” is included at or near the guide of the energy guide located inside the balloon. This localized plasma induces a pressure wave that applies pressure to the treatment site within or near the vessel wall in the patient and induces rupture at the treatment site. As used herein, the treatment site may include vascular lesions, such as calcified or fibrotic vascular lesions typically found in blood vessels and / or heart valves.

[0030] Specifically, in various embodiments, the catheter system may include a catheter configured to be advanced into or near a treatment site within a blood vessel or heart valve in a patient. The catheter includes a catheter shaft and a balloon coupled to and / or secured to the catheter shaft. The balloon described herein may include a balloon wall defining an interior and may be configured to receive balloon fluid within the balloon to inflate from a contraction configuration to an expansion configuration, the contraction configuration being adapted to advance the catheter through the patient's vascular system, and the expansion configuration being adapted to anchor the catheter in a suitable position relative to the treatment site. The catheter system also includes one or more energy guides, such as light guides, disposed along the catheter shaft and located within the balloon. Each energy guide may be configured to generate a pressure wave within the balloon to destroy vascular lesions. The catheter system utilizes energy from an energy source, such as light energy from a light source, to generate plasma within the balloon fluid at or near the distal end of the energy guide disposed within the balloon at the treatment site, i.e., plasma is generated by a plasma generator. The formation of plasma can induce one or more pressure waves and the rapid formation of one or more bubbles, which can rapidly expand to their maximum size and then dissipate via a cavitation event, which can emit pressure waves upon collapse. The rapid expansion of these plasma-induced bubbles can generate one or more pressure waves in the balloon fluid retained within the balloon, thereby applying these pressure waves to the treatment site. In some embodiments, an energy source can be configured to provide submillisecond pulses of energy (e.g., light energy) to induce plasma formation in the balloon fluid within the balloon, resulting in rapid bubble formation and the application of pressure waves to the balloon walls at the treatment site. Thus, the pressure waves can transfer mechanical energy to the treatment site through the incompressible balloon fluid, thereby applying a fracture force to the treatment site.

[0031] Importantly, as described in detail herein, the conduit system of the present invention includes an optical analyzer assembly configured to provide real-time, continuous monitoring of light emitted from the light guide into the balloon. This optical analyzer assembly can be used to detect the occurrence of a plasma event and also serves as a monitor for the normal operation of the conduit system. Additionally, the optical analyzer assembly can be used to measure the intensity of the light energy emitted from the light guide to provide a precise measurement of the energy output of the plasma generator, which is incorporated as part of the light guide. More specifically, the measurement of the plasma generator's energy output can be used in conjunction with a known energy input from an energy source to determine the conversion efficiency. Such a metric can also be used to assess the condition of the plasma generator and the light guide, and to determine whether the conduit system is operating normally and the number of remaining operating cycles.

[0032] More specifically, in various embodiments, as described in detail herein, the invention includes means for sampling light returning from a plasma generator and / or from inside a balloon via a light guide. It is to be understood that light energy can propagate in two opposite directions along the length of the light guide. Therefore, emitted light can be detected at the distal end of the light guide, or at any other location along the length of the light guide, or at the proximal end of the light guide. Thus, this light energy returning through the light guide will be separated, detected, and / or analyzed via an optical analyzer assembly to effectively monitor the performance, reliability, and safety of the catheter system, as described in detail herein.

[0033] It is to be understood that by using this invention, as described in detail herein, continuous monitoring of the light energy emitted from a plasma generator and measurement of the intensity of the emitted light energy solve several potential problems in the performance, reliability, and safety of IVL catheters, particularly IVL catheters that utilize an energy source to generate localized plasma (which in turn generates a high-energy bubble within the balloon catheter). Specific problems solved by this invention include: 1) optical detection of successful excitation of an energy source (e.g., a laser source) to generate plasma within the balloon; 2) accurate determination of the energy output of the plasma generator; 3) optical detection of malfunctions in catheter systems that fail to generate the desired plasma within the balloon; and 4) optical detection of malfunctions of the light guide at arbitrary points along the length of the light guide.

[0034] As used herein, the terms “intracranial lesion,” “vascular lesion,” and “treatment site” are used interchangeably unless otherwise stated. Therefore, intravascular lesions and / or vascular lesions are sometimes simply referred to as “lesions” in this document.

[0035] 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 conceive of themselves by those skilled in the art who will benefit from this disclosure. Detailed reference will now be made to the embodiments of the invention illustrated in the accompanying drawings.

[0036] For clarity, not all conventional features of the embodiments described herein are shown and described. It is to be understood that in the development of any such actual embodiment, many decisions specific to that embodiment must be made to achieve the developer’s specific objectives, such as compliance with application-related and business-related constraints, and these specific objectives will vary from one embodiment to another and from one developer to another. Furthermore, it is to be understood that such development efforts may be complex and time-consuming; however, this is merely a routine engineering task for those skilled in the art who benefit from this disclosure.

[0037] It should be understood that the catheter systems disclosed herein can include many different forms. Now refer to Figure 1 A schematic cross-sectional view of a catheter system 100 according to various embodiments herein is shown. As described herein, the catheter system 100 is adapted to apply pressure to induce rupture in one or more vascular lesions, either within or adjacent to the vessel wall, or on or near a heart valve in a patient. Figure 1 In the illustrated embodiment, the conduit system 100 may include one or more of a conduit 102, a light guide beam 122, a source manifold 136, a fluid pump 138, and a system console 123. The light guide beam 122 includes one or more light guides 122A, and the system console 123 includes one or more of a light source 124, a power source 125, a system controller 126, a graphical user interface 127 (“GUI”), a handle assembly 128, and an optical analyzer assembly 142.

[0038] The catheter 102 is configured to move into a blood vessel 108 within the body 107 of the patient 109 or to a treatment site 106 adjacent to the blood vessel 108. The treatment site 106 may include one or more vascular lesions, such as calcified vascular lesions. Alternatively, the treatment site 106 may also include vascular lesions such as fibrotic vascular lesions.

[0039] The catheter 102 may include an expandable balloon 104 (sometimes simply referred to herein as a “balloon”), a catheter shaft 110, and a guidewire 112. The balloon 104 may be coupled to the catheter shaft 110. The balloon 104 may include a proximal balloon 104P and a distal balloon 104D. The catheter shaft 110 may extend from a proximal portion 114 of the catheter system 100 to a distal portion 116 of the catheter system 100. The catheter shaft 110 may include a longitudinal axis 144. The catheter shaft 110 may also include a guidewire lumen 118 configured to move on the guidewire 112. The catheter shaft 110 may also include an expansion lumen (not shown). In some embodiments, the catheter 102 may have a distal opening 120, and the distal opening 120 may receive and be tracked on the guidewire 112 as the catheter 102 moves and is positioned at or near the treatment site 106.

[0040] The conduit axis 110 of conduit 102 may be coupled to one or more light guides 122A of the light guiding bundle 122 that are in optical communication with the light source 124. The light guides 122A may be positioned along the conduit axis 110 and located within the balloon 104. In some embodiments, each light guide 122A may be an optical fiber, and the light source 124 may be a laser. The light source 124 may be in optical communication with the light guides 122A at a proximal portion 114 of the conduit system 100.

[0041] In some embodiments, the catheter shaft 110 may be coupled to a plurality of light guides 122A, such as a first light guide, a second light guide, a third light guide, etc., which may be positioned at any suitable location around the guidewire lumen 118 and / or the catheter shaft 110. For example, in some non-exclusive embodiments, two light guides 122A may be circumferentially spaced approximately 180 degrees around the guidewire lumen 118 and / or the catheter shaft 110; three light guides 122A may be circumferentially spaced approximately 120 degrees around the guidewire lumen 118 and / or the catheter shaft 110; or four light guides 122A may be circumferentially spaced approximately 90 degrees around the guidewire lumen 118 and / or the catheter shaft 110. Alternatively, the plurality of light guides 122A need not be uniformly spaced from each other circumferentially around the guidewire lumen 118 and / or the catheter shaft 110. More specifically, it should also be understood that the light guide 122A described herein can be uniformly or non-uniformly positioned around the guidewire cavity 118 and / or the catheter axis 110 to achieve the desired effect at the desired location.

[0042] Balloon 104 may include a balloon wall 130 defining a balloon interior 146 and may be expanded using balloon fluid 132 to inflate from a contraction configuration to an expansion configuration, the contraction configuration being adapted to advance catheter 102 through a patient's vascular system and the contraction configuration being adapted to anchor catheter 102 in a suitable position relative to treatment site 106. Alternatively, when balloon 104 is in the expansion configuration, the balloon wall 130 of balloon 104 is configured to be positioned substantially adjacent to treatment site 106, i.e., adjacent (one or more) vascular lesions. In some embodiments, a light source 124 of the catheter system 100 may be configured to provide submillisecond light pulses from the light source 124 along a light guide 122A to a location within the balloon interior 146 of balloon 104, thereby inducing plasma formation in the balloon fluid 132 within the balloon interior 146 of balloon 104. Plasma formation causes rapid bubble formation and applies a pressure wave to treatment site 106. An exemplary plasma-induced bubble formation in… Figure 1 It is shown as bubble 134.

[0043] It should be understood that although the catheter system 100 shown herein is generally described as including a light source 124 and including one or more light guides 122A, the catheter system 100 may alternatively include any suitable energy source and energy guide to generate the desired plasma in the balloon fluid 132 within the balloon interior 146.

[0044] Balloons 104 suitable for use in the catheter system 100 described in detail herein include those balloons 104 that can pass through a patient's vascular system when in a contracted configuration. In some embodiments, the balloons 104 herein are made of silicone. In other embodiments, the balloons 104 herein are made of polydimethylsiloxane (PDMS), polyurethane, polymers, nylon, etc.; wherein polymers, such as PEBAX available from Arkema, are used. TM Materials, Arkema is located in King of Prussia, Pennsylvania, USA. In some embodiments, balloon 104 may include balloons with a diameter ranging from 1 mm to 25 mm. In some embodiments, balloon 104 may include balloons with a diameter ranging from at least 1.5 mm to 12 mm. In some embodiments, balloon 104 may include balloons with a diameter ranging from at least 1 mm to 5 mm.

[0045] Furthermore, in some embodiments, the balloon 104 herein may include balloons with a length ranging from at least 5 mm to 300 mm. More specifically, in some embodiments, the balloon 104 herein may include balloons with a length ranging from at least 8 mm to 200 mm. It is to be understood that a longer balloon 104 can be positioned near a larger treatment site 106 and can therefore be used to apply pressure to and induce rupture of larger vascular lesions or multiple vascular lesions at a precise location within the treatment site 106.

[0046] Furthermore, the balloon 104 of this invention can be inflated to an inflation pressure between approximately one atmosphere (atm) and 70 atmospheres. In some embodiments, the balloon 104 of this invention can be inflated to an inflation pressure of at least 20 atm to 70 atm. In other embodiments, the balloon 104 of this invention can be inflated to an inflation pressure of at least 6 atm to 20 atm. In still other embodiments, the balloon 104 of this invention can be inflated to an inflation pressure of at least 3 atm to 20 atm. In still other embodiments, the balloon 104 of this invention can be inflated to an inflation pressure of at least 2 atm to 10 atm.

[0047] Furthermore, the balloon 104 described herein may include balloons of various shapes, including but not limited to conical, square, rectangular, spherical, conical / square, conical / spherical, extended spherical, elliptical, conical, bony, stepped diameter, offset, or conical offset shapes. In some embodiments, the balloon 104 described herein may include a drug-eluting coating or a drug-eluting stent structure. The drug-eluting coating or drug-eluting stent may include one or more therapeutic agents, including anti-inflammatory agents, antitumor agents, anti-angiogenic agents, etc.

[0048] The balloon fluid 132 can be a liquid or a gas. Exemplary balloon fluid 132 suitable for use herein may include, but is not limited to, one or more of water, saline, contrast agents, fluorocarbons, perfluorocarbons, gases such as carbon dioxide, and the like. In some embodiments, the described balloon fluid 132 can be used as a base expansion fluid. In some embodiments, the balloon fluid 132 comprises a mixture of saline and contrast agent in a volume ratio of 50:50. In other embodiments, the balloon fluid 132 comprises a mixture of saline and contrast agent in a volume ratio of 25:75. In still other embodiments, the balloon fluid 132 comprises a mixture of saline and contrast agent in a volume ratio of 75:25. Additionally, the balloon fluid 132 suitable for use herein can be adjusted according to its composition, viscosity, etc., to manipulate the propagation rate of pressure waves therein. In some embodiments, the balloon fluid 132 suitable for use herein is biocompatible. The volume of the balloon fluid 132 can be adjusted by the selected light source 124 and the type of balloon fluid 132 used.

[0049] In some embodiments, the contrast agent used in the contrast media may include, but is not limited to, iodine-based contrast agents, such as ionic or non-ionic iodine-based contrast agents. Some non-limiting examples of ionic iodine-based contrast agents include diatrizoate, metrizoate, iothalamate, and ioxaglate. Some non-limiting examples of non-ionic iodine-based contrast agents include iopamidol, iohexol, ioxilan, iopramide, iodixanol, and ioversol. In other embodiments, non-iodine-based contrast agents may be used. Suitable non-iodine-containing contrast agents may include gadolinium(III)-based contrast agents. Suitable fluorocarbon agents and perfluorocarbon agents may include, but are not limited to, formulations such as perfluorocarbon dodecafluoropentane (DDFP, C5F12).

[0050] Furthermore, the balloon fluid 132 herein may include those balloon fluids comprising an absorbent that selectively absorbs light in the ultraviolet region (e.g., at least 10 nanometers (nm) to 400 nanometers), the visible region (e.g., at least 400 nm to 780 nm), or the near-infrared region (e.g., at least 780 nm to 2.5 μm) of the electromagnetic spectrum. Suitable absorbents may include those that have maximum absorption within a spectral range of at least 10 nm to 2.5 μm. Alternatively, the balloon fluid 132 may include those fluids comprising an absorbent that selectively absorbs light in the mid-infrared region (e.g., at least 2.5 μm to 15 μm) or the far-infrared region (e.g., at least 15 μm to 1 mm) of the electromagnetic spectrum. In various embodiments, the absorbent may be an absorbent having an absorption maximum value that matches the emission maximum value of a laser used in a catheter system. As a non-limiting example, the various lasers described herein may include neodymium:yttrium aluminum garnet (Nd:YAG, maximum emission = 1064 nm) lasers, holmium:YAG (Ho:YAG, maximum emission = 2.1 μm) lasers, or erbium:YAG (Er:YAG, maximum emission = 2.94 μm) lasers. In some embodiments, the absorbent used herein may be water-soluble. In other embodiments, the absorbent used herein is not water-soluble. In some embodiments, the absorbent used in the balloon fluid 132 herein may be adjusted to match the peak emission of the light source 124. The various light sources 124 discussed elsewhere herein have emission wavelengths ranging from at least ten nanometers to one millimeter.

[0051] It is to be understood that the catheter system 100 and / or the light guiding beam 122 disclosed herein may include any number of light guides 122A, which are in optical communication with a light source 124 at a proximal portion 114 and with balloon fluid 132 within the balloon interior 146 of the balloon 104 at a distal portion 116. For example, in some embodiments, the catheter system 100 and / or the light guiding beam 122 may include one to five light guides 122A. In other embodiments, the catheter system 100 and / or the light guiding beam 122 may include five to fifteen light guides 122A. In other embodiments, the catheter system 100 and / or the light guiding beam 122 may include ten to thirty light guides 122A. Alternatively, in still other embodiments, the catheter system 100 and / or the light guiding beam 122 may include more than 30 light guides 122A.

[0052] The light guide 122A of this invention may include an optical fiber or a flexible optical tube. The light guide 122A of this invention may be thin and flexible, and may allow optical signals to be transmitted with very little intensity loss. The light guide 122A of this invention may include a core surrounded by a cladding around its circumference. In some embodiments, the core may be a cylindrical core or a partially cylindrical core. The core and cladding of the light guide 122A may be formed of one or more materials, including but not limited to one or more types of glass, silica, or one or more polymers. The light guide 122A may also include a protective coating, such as a polymer. It is to be understood that the refractive index of the core will be greater than the refractive index of the cladding.

[0053] Each light guide 122A can guide light along its length from a proximal portion (i.e., the proximal end 122P of the guide) to a distal portion (i.e., the distal end 122D of the guide), and each light guide 122A has at least one optical window (not shown) positioned within the interior 146 of the balloon. The light guide 122A can generate an optical path as part of an optical network including the light source 124. An optical path within the optical network allows light to propagate from one part of the network to another. In this document, both optical fibers and flexible optical tubes can provide an optical path within the optical network.

[0054] As provided herein, the distal end 122D of the light guide may further include and / or include a distal optical receiver 122R, which allows optical energy to move back into the light guide 122A and through the light guide 122A from the distal end 122D to the proximal end 122P. In other words, optical energy can move along the light guide 122A in a first direction 121F, which is generally from the proximal end 122P of the light guide 122A toward the distal end 122D. At least a portion of the optical energy can also move along the light guide 122A in a second direction 121S, which is substantially opposite to the first direction 121F, i.e., from the distal end 122D of the light guide 122A toward the proximal end 122P. Furthermore, as described in more detail below, the light energy emitted from the proximal end 122P of the guide can be separated after being moved back through the light guide 122A (in the second direction 121S), and then optically detected, probed, and / or analyzed using the optical analyzer assembly 142.

[0055] Furthermore, the light guide 122A described herein can be configured in a variety of ways around and / or relative to the catheter shaft 110 of the catheter 102 described herein. In some embodiments, the light guide 122A may extend parallel to the longitudinal axis 144 of the catheter shaft 110. In some embodiments, the light guide 122A may be physically coupled to the catheter shaft 110. In other embodiments, the light guide 122A may be disposed along the length of the outer diameter of the catheter shaft 110. In still other embodiments, the light guide 122A described herein may be disposed within one or more light guide cavities within the catheter shaft 110.

[0056] Furthermore, it should be understood that the light guide 122A can be positioned at any suitable location around the circumference of the guidewire lumen 118 and / or the catheter shaft 110, and the distal guide end 122D of each light guide 122A can be positioned at any suitable longitudinal location relative to the length of the balloon 104 and / or relative to the length of the guidewire lumen 118.

[0057] Furthermore, the light guide 122A herein may include one or more photoacoustic transducers 154, wherein each photoacoustic transducer 154 may be optically communicated with the light guide 122A (in which the photoacoustic transducer 154 is disposed). In some embodiments, the photoacoustic transducer 154 may be optically communicated with the guide distal end 122D of the light guide 122A. Furthermore, in these embodiments, the photoacoustic transducer 154 may have a shape corresponding to and / or conforming to the guide distal end 122D of the light guide 122A.

[0058] The photoacoustic transducer 154 is configured to convert light energy into sound waves at or near the distal end 122D of the light guide 122A. It should be understood that the direction of the sound waves can be adjusted by changing the angle of the distal end 122D of the light guide 122A.

[0059] It should also be understood that, in this document, the photoacoustic transducer 154 disposed at the distal end 122D of the light guide 122A may have the same shape as the distal end 122D of the light guide 122A. For example, in some non-exclusive embodiments, the photoacoustic transducer 154 and / or the distal end 122D of the light guide may have a conical shape, a convex shape, a concave shape, a bulbous shape, a square shape, a stepped shape, a semi-circular shape, an oval shape, etc. It should also be understood that the light guide 122A may further include additional photoacoustic transducers 154 disposed along one or more side surfaces along the length of the light guide 122A.

[0060] The light guide 122A described herein may also include one or more steering features or "steering devices" within the light guide 122A. Figure 1(Not shown in the diagram), which is configured to guide light toward, for example, a side surface at or near the guide distal end 122D of the light guide 122A and toward the balloon wall 130 exiting the light guide 122A. The steering feature can include any feature of the present system that redirects light from the light guide 122A away from its axial path toward the side surface of the light guide 122A. Furthermore, each light guide 122A can include one or more optical windows disposed along the longitudinal or axial surface of each light guide 122A and in optical communication with the steering feature. Alternatively, the steering feature of the present invention can be configured to guide light in the light guide 122A toward a side surface, for example, at or near the guide distal end 122D, wherein the side surface is in optical communication with the optical windows. The light window may include a portion of the light guide 122A that allows light to exit from within the light guide 122A, such as a portion of the light guide 122A or its surroundings that lacks cladding material.

[0061] Examples of steering features suitable for use herein include reflective elements, refractive elements, and fiber optic diffusers. Furthermore, steering features suitable for focusing light away from the tip of the light guide 122A may include, but are not limited to, steering features with convex surfaces, gradient-index (GRIN) lenses, and specular focusing lenses. Upon contact with the steering feature, light is directed within the light guide 122A to a photoacoustic transducer 154 that is optically connected to the side surface of the light guide 122A. As described above, the photoacoustic transducer 154 then converts the light energy into sound waves that propagate away from the side surface of the light guide 122A.

[0062] The source manifold 136 may be located at or near the proximal portion 114 of the catheter system 100. The source manifold 136 may include one or more proximal openings that may receive multiple light guides 122A of the light guiding beam 122, guidewires 112, and / or an expansion catheter 140 fluidly coupled to a fluid pump 138. The catheter system 100 may also include a fluid pump 138 configured to expand a balloon 104 with balloon fluid 132 as needed.

[0063] As mentioned above, in Figure 1 In the illustrated embodiment, system console 123 includes one or more of a light source 124, a power supply 125, a system controller 126, and a GUI 127. Alternatively, system console 123 may include more than Figure 1The components shown may have more or fewer components. For example, in some non-exclusive alternative embodiments, the system console 123 may be designed without a GUI 127. Alternatively, one or more of the light source 124, power supply 125, system controller 126, and GUI 127 may be located within the conduit system 100 without specifically requiring a system console 123.

[0064] In addition, such as Figure 1 As shown, in some embodiments, at least a portion of the optical analyzer assembly 142 may also be substantially located within the system console 123. Alternatively, components of the optical analyzer assembly 142 may be coupled with... Figure 1 The different positioning methods are specifically shown in the text.

[0065] Furthermore, as shown in the figure, the system console 123 and its included components are operatively coupled to the catheter 102, the light guide beam 122, and the remainder of the catheter system 100. For example, in some embodiments, such as Figure 1 As shown, the system console 123 may include a console connection hole 148 (sometimes also generally referred to as a "receptacle") through which the optical guide beam 122 is mechanically coupled to the system console 123. In such an embodiment, the optical guide beam 122 may include a guide coupling housing 150 (sometimes also generally referred to as a "ring") that accommodates a portion of each optical guide 122A, such as the guide proximal end 122P. The guide coupling housing 150 is configured to engage and selectively retain within the console connection hole 148 to provide the desired mechanical coupling between the optical guide beam 122 and the system console 123.

[0066] In addition, the light guiding bundle 122 may also include a guiding bundle 152 (or “shell”) that brings each of the individual light guides 122A together more tightly, so that the light guides 122A and / or the light guiding bundle 122 can be in a more compact form when the light guides 122A and / or the light guiding bundle 122 are extended into the blood vessel 108 together with the catheter 102 during use of the catheter system 100.

[0067] As provided herein, light source 124 may be selectively and / or alternatively optically coupled to each light guide 122A in the light guiding beam 122, i.e., optically connected to the guide proximal end 122P of each light guide 122A in the light guiding beam 122. Specifically, light source 124 is configured to generate light energy in the form of a source beam 124A, such as a pulsed source beam, which may be selectively and / or alternatively guided to each light guide 122A in the light guiding beam 122 and received by each light guide 122A in the light guiding beam 122 as a separate guide beam 124B. Alternatively, conduit system 100 may include more than one light source 124. For example, in a non-exclusive alternative embodiment, conduit system 100 may include a separate light source 124 for each light guide 122A in the light guiding beam 122.

[0068] The light source 124 can have any suitable design. In some embodiments, as described above, the light source 124 can be configured to provide submillisecond light pulses focused onto a small spot for coupling to the guide proximal end 122P of the light guide 122A. Such light energy pulses are then guided along the light guide 122A to a location within the balloon 104, thereby inducing plasma formation in the balloon fluid 132 within the balloon interior 146 of the balloon 104. Specifically, light energy emitted at the guide distal end 122D of the light guide 122A excites a plasma generator to form plasma within the balloon fluid 132 within the balloon interior 146. The formation of plasma causes rapid bubble formation and applies pressure waves to the treatment site 106. In such embodiments, the submillisecond light pulses from the light source 124 can be delivered to the treatment site 106 at a frequency between approximately 1 Hz and 5000 Hz. In some embodiments, submillisecond light pulses from light source 124 may be transmitted to treatment site 106 at a frequency between approximately 30 Hz and 1000 Hz. In other embodiments, submillisecond light pulses from light source 124 may be transmitted to treatment site 106 at a frequency between approximately 10 Hz and 100 Hz. In still other embodiments, submillisecond light pulses from light source 124 may be transmitted to treatment site 106 at a frequency between approximately 1 Hz and 30 Hz. Alternatively, submillisecond light pulses may be transmitted to treatment site 106 at a frequency greater than 5000 Hz.

[0069] It should be understood that although light source 124 is typically used to provide light energy pulses, light source 124 can still be described as providing a single light source beam 124A, i.e., a single pulse light source beam.

[0070] The light source 124 suitable for use herein may include various types of light sources, including lasers and lamps. For example, in some non-exclusive embodiments, the light source 124 may be an infrared laser that emits light energy in the form of infrared light pulses. Alternatively, as described herein, the light source 124 may include any suitable type of energy source.

[0071] Suitable lasers may include short-pulse lasers operating on a sub-millisecond timescale. In some embodiments, light source 124 may include a laser operating on a nanosecond (ns) timescale. Lasers may also include short-pulse lasers operating on picosecond (ps), femtosecond (fs), and microsecond (µs) timescales. It is to be understood that many combinations of laser wavelength, pulse width, and energy level can be used to achieve plasma in the balloon fluid 132 of the catheter 102 described herein. In various embodiments, pulse widths may include those falling within a range from at least 10 ns to 200 ns. In some embodiments, pulse widths may include those falling within a range from at least 20 ns to 100 ns. In other embodiments, pulse widths may include those falling within a range from at least 1 ns to 500 ns.

[0072] Furthermore, exemplary nanosecond lasers may include those spanning wavelengths from approximately 10 nanometers (nm) to 1 millimeter (mm) in the ultraviolet to infrared spectrum. In some embodiments, a light source 124 suitable for use in the conduit system 100 herein may include a light source capable of generating light with wavelengths from at least 750 nm to 2000 nm. In other embodiments, light source 124 may include a light source capable of generating light with wavelengths from at least 700 nm to 3000 nm. In still other embodiments, light source 124 may include a light source capable of generating light with wavelengths from at least 100 nanometers to 10 micrometers (μm). Nanosecond lasers may include those with repetition rates up to 200 kHz. In some embodiments, the laser may include a Q-switched thulium:yttrium aluminum garnet (Tm:YAG) laser. In other embodiments, the laser may include a neodymium:yttrium aluminum garnet (Nd:YAG) laser, a holmium:yttrium aluminum garnet (Ho:YAG) laser, an erbium:yttrium aluminum garnet (Er:YAG) laser, an excimer laser, a helium-neon laser, a carbon dioxide laser, as well as a doped laser, a pulsed laser, or a fiber laser.

[0073] The catheter system 100 disclosed herein can generate a pressure wave with a maximum pressure ranging from at least 1 MPa to 100 MPa. The maximum pressure generated by a particular catheter system 100 will depend on the light source 124, the absorbing material, the bubble expansion, the propagation medium, the balloon material, and other factors. In some embodiments, the catheter system 100 of this invention can generate a pressure wave with a maximum pressure ranging from at least 2 MPa to 50 MPa. In other embodiments, the catheter system 100 of this invention can generate a pressure wave with a maximum pressure ranging from at least 2 MPa to 30 MPa. In still other embodiments, the catheter system 100 of this invention can generate a pressure wave with a maximum pressure ranging from at least 15 MPa to 25 MPa.

[0074] When the catheter 102 is placed at the treatment site 106, the pressure wave described herein can be applied to the treatment site 106 over a distance ranging from at least 0.1 mm to 25 mm radially extending from the light guide 122A. In some embodiments, when the catheter 102 is placed at the treatment site 106, the pressure wave can be applied to the treatment site 106 over a distance ranging from at least 10 mm to 20 mm radially extending from the light guide 122A. In other embodiments, when the catheter 102 is placed at the treatment site 106, the pressure wave can be applied to the treatment site 106 over a distance ranging from at least 1 mm to 10 mm radially extending from the light guide 122A. In still other embodiments, when the catheter 102 is placed at the treatment site 106, the pressure wave can be applied to the treatment site 106 over a distance ranging from at least 1.5 mm to 4 mm radially extending from the light guide 122A. In some embodiments, a pressure wave ranging from at least 2 MPa to 30 MPa can be applied to the treatment site 106 at a distance ranging from 0.1 mm to 10 mm. In some embodiments, pressure waves ranging from at least 2 MPa to 25 MPa can be applied to the treatment site 106 at a distance of 0.1 mm to 10 mm.

[0075] Power supply 125 is electrically coupled to each of the light source 124, system controller 126, GUI 127, handle assembly 128, and optical analyzer assembly 142, and is configured to provide them with the necessary power. Power supply 125 can have any suitable design for this purpose.

[0076] As described above, system controller 126 is electrically coupled to and receives power from power supply 125. Furthermore, system controller 126 is coupled to and configured to control the operation of each of the light source 124, GUI 127, and optical analyzer assembly 142. System controller 126 may include one or more processors or circuitry for controlling the operation of at least the light source 124, GUI 127, and optical analyzer assembly 142. For example, system controller 126 can control light source 124 to generate light energy pulses as needed, such as generating light energy pulses at any desired excitation rate. Furthermore, system controller 126 can control and / or operate in conjunction with optical analyzer assembly 142 to effectively provide real-time continuous monitoring of the performance, reliability, and safety of conduit system 100.

[0077] Furthermore, the system controller 126 can also be configured to control the operation of other components of the catheter system 100, such as the positioning of the catheter 102 adjacent to the treatment site 106, the inflation of the balloon 104 using balloon fluid 132, etc. Alternatively, the catheter system 100 may include one or more additional controllers, which can be positioned in any suitable manner to control various operations of the catheter system 100. For example, in some embodiments, an additional controller and / or a portion of the system controller 126 may be positioned and / or included within the handle assembly 128.

[0078] The GUI 127 is accessible to the user or operator of the catheter system 100. Additionally, the GUI 127 is electrically connected to the system controller 126. This design allows the user or operator to use the GUI 127 to ensure that the catheter system 100 is used as needed to apply pressure to the vascular lesion at the treatment site 106 and induce rupture within the lesion. Furthermore, the GUI 127 can provide the user or operator with information that can be used before, during, and after the use of the catheter system 100. In one embodiment, the GUI 127 can provide the user or operator with static visual data and / or information. Alternatively, for example, during the use of the catheter system 100, the GUI 127 can provide the user or operator with dynamic visual data and / or information, such as video data or any other data that changes over time. Furthermore, in various embodiments, the GUI 127 may include one or more colors, different sizes, different brightness levels, etc., which can serve as an alert to the user or operator. Alternatively, the GUI 127 can provide the user or operator with audio data or information. It should be understood that the details of GUI 127 may vary depending on the design requirements of the conduit system 100 or the specific needs, specifications and / or expectations of the user or operator.

[0079] like Figure 1 As shown, the handle assembly 128 can be positioned at or near the proximal portion 114 of the catheter system 100, and / or near the source manifold 136. Furthermore, in this embodiment, the handle assembly 128 is coupled to and positioned spaced apart from the balloon 104. Alternatively, the handle assembly 128 can be positioned at another suitable location.

[0080] The handle assembly 128 is manipulated and used by a user or operator to operate, position, and control the catheter 102. The design and specific features of the handle assembly 128 can be modified to suit the design requirements of the catheter system 100. Figure 1 In the illustrated embodiment, the handle assembly 128 is separate from, but electrically and / or fluidly connected to, one or more of the system controller 126, light source 124, fluid pump 138, GUI 127, and optical analyzer assembly 142. In some embodiments, the handle assembly 128 may be integrated within and / or include at least a portion of the system controller 126. For example, as shown, in some such embodiments, the handle assembly 128 may include circuitry 156, which may form at least a portion of the system controller 126. Additionally, in some embodiments, the circuitry 156 may receive electrical signals or data from the optical analyzer assembly 142. Furthermore, or alternatively, the circuitry 156 may transmit such electrical signals or otherwise provide data to the system controller 126.

[0081] In one embodiment, circuitry 156 may include a printed circuit board having one or more integrated circuits, or any other suitable circuitry. In alternative embodiments, circuitry 156 may be omitted, or may be included within system controller 126, which in various embodiments may be located external to handle assembly 128, for example, within system console 123. It is to be understood that handle assembly 128 may include fewer or more components than those specifically shown and described herein.

[0082] As a general overview, and as provided in more detail herein, the optical analyzer assembly 142 is configured to effectively monitor the performance, reliability, and safety of the catheter system 100. During use of the catheter system 100, when plasma initially forms in the balloon fluid 132 inside the balloon, the plasma emits broad-spectrum electromagnetic radiation. Furthermore, as described above, at least a portion of the emitted light energy can be reflected from or otherwise received by the distal light receiver 122R near the distal end 122D of the light guide 122A. Thus, this portion of the light energy can propagate back through the light guide 122A to the proximal end 122P of the guide in a second direction 121S, where it can be separated and detected. The intensity and timing of the visible light pulse relative to the plasma-generating pulse from the light source 124 provide an indication of the plasma generator's operation, its energy output, and its functional status. It should be understood that if the light guide 122A is damaged or broken, visible light flashes may occur at other locations along the length of the light guide 122A. Such additional flashes will also be coupled into the light guide 122A and brought back to the proximal end 122P of the guide in the second direction 121S. The intensity and timing of these additional light pulses can indicate a damaged light guide 122A or a damaged plasma generator.

[0083] It is important to understand that a malfunction of the energy-driven plasma generator or associated light guide 122A, for example, if light guide 122A breaks or is damaged during use of catheter system 100, could result in energy leakage that could cause injury to the patient or operator. Potential hazards include tissue burns and retinal damage. As described above, in some embodiments, energy source 124 is a laser that emits invisible infrared light, making it impossible for the operator to perform visible detection. Therefore, if optical analyzer assembly 142 indicates that any such malfunction has occurred, procedures and energy delivery, such as laser energy delivery, must be immediately stopped to mitigate the associated risks to the patient and operator. Alternatively, utilizing the design of the optical analyzer assembly 142 described herein, the present invention detects any noticeable malfunction within catheter system 100, such as breakage, damage, or malfunction of light guide 122A and / or plasma generator, and provides an indication or signal that system controller 126 can use to lock out energy source 124. This provides a necessary safety interlock for potentially hazardous situations where energy source 124 may leak in an undesirable manner. In addition, the system controller 126 can be used, for example, via the GUI 127 to instruct the surgeon to stop the procedure and remove the catheter 102 from the patient 109 during treatment.

[0084] Furthermore, it should be understood that the optical analyzer assembly 142 can have any suitable design to effectively monitor the performance, reliability, and safety of the conduit system 100. Some non-exclusive examples of potential designs for the optical analyzer assembly 142 are described in detail below.

[0085] Figure 2 This is a simplified schematic diagram of a portion of an embodiment of catheter system 200, which includes an embodiment of optical analyzer assembly 242. The design of catheter system 200 is substantially similar to the embodiments shown and described above. It is to be understood that, for clarity and ease of illustration, various components of catheter system 200, such as... Figure 1 As shown, not in Figure 2 As shown in the diagram. However, it should be understood that the catheter system 200 will likely include most (if not all) of such components.

[0086] like Figure 2 As shown, the conduit system 200 again includes an energy source 224, which is configured to generate light energy in the form of a light source beam 224A (e.g., a pulsed light source beam), which can be selectively and / or alternatively directed to each light guide 222A. Figure 2 Only one light guide is shown in the diagram, and each light guide 222A receives the light as a separate guide beam 224B. In a non-exclusive embodiment, the energy source 224 is an infrared laser source, while the light guide 222A is a small-diameter multimode optical fiber. Figure 2 In the illustrated embodiment, pulse generator 260 is coupled to energy source 224. Pulse generator 260 is configured to trigger energy source 224, so that energy source 224 emits energy pulses as a light source beam 224A. In some embodiments, the light source beam 224A from energy source 224 passes through optical element 262, such as a focusing lens, which is configured to focus the light source beam 224A as a separate guide beam 224B downwards onto the guide proximal end 222P of light guide 222A, thereby coupling infrared energy pulses (i.e., the separate guide beam 224B) into light guide 222A.

[0087] Subsequently, an infrared energy pulse, namely a separate guide beam 224B, propagates along and / or through the light guide 222A and excites a plasma generator 264, which is positioned and / or contained at or near the guide distal end 222D of the light guide 222A. The plasma generator 264 utilizes the infrared energy pulse within the balloon 104 (e.g., Figure 1 The interior of the balloon (as shown) 146 (as shown) Figure 1 The balloon fluid 132 (as shown) inside the balloon (as shown) Figure 1 Local plasma is generated in (as shown).

[0088] In various embodiments, when plasma is generated in the balloon fluid 132 within the balloon interior 146, a broad-spectrum light energy pulse emitted from the plasma is coupled back to the distal end 222D of the light guide 222A. This broad-spectrum light energy pulse then propagates back along and / or through the light guide 222A, i.e., emitted as a return energy beam 224C from the proximal end 222P of the light guide 222A.

[0089] As described in detail herein, the optical analyzer assembly 242 is configured to effectively monitor the performance, reliability, and safety of the conduit system 200 by optically analyzing the light energy emitted from the guide proximal end 222P of the light guide 222A (e.g., the return energy beam 224C). The design of the optical analyzer assembly 242 can be varied to suit the specific requirements of the conduit system 200. In particular, in Figure 2 In the illustrated embodiment, the optical analyzer assembly 242 includes one or more of a beam splitter 266, an optical element 268 (e.g., a coupling lens), a photodetector 270, and a signal conditioning and processing system 272. Furthermore, as shown, the signal conditioning and processing system 272 may include one or more of an amplifier 274, a discriminator 276, and control electronics 278, which may include one or more processors or circuits. Alternatively, in other embodiments, the optical analyzer assembly 242 and / or the signal conditioning and processing system 272 may include more or fewer components than specifically shown and described herein.

[0090] As shown, beam splitter 266, such as a dichroic beam splitter, is positioned in the optical path of energy source 224 and near the guide proximal end 222P of light guide 222A. In some embodiments, beam splitter 266 is configured to allow light with wavelengths longer than those visible to photodetector 270 to pass through. This may be referred to as the cutoff wavelength. Beam splitter 266 is also configured to reflect all light with wavelengths shorter than the cutoff wavelength. Figure 2As shown, the return energy beam 224C emitted from the guide proximal end 222P of the light guide 222A is reflected by the beam splitter 266 and coupled to the photodetector 270 using an optical element 268. More specifically, the optical element 268, such as a coupling lens, is located between the beam splitter 266 and the photodetector 270 in the optical path of the return energy beam 224C after it has been reflected by the beam splitter 266. The optical element 268 effectively images the guide proximal end 222P of the light guide onto the photodetector 270, thereby coupling the light energy emitted from the guide proximal end 222P of the light guide 222A (i.e., in the form of the return energy beam 224C) to the photodetector 270. With this design, visible light emitted from the plasma formed at the guide distal end 222D of the light guide 222A is collected by the photodetector 270.

[0091] Additionally, in some embodiments, the photodetector 270 generates a signal based on visible light emitted from plasma formed at the distal end 222D of the light guide 222A and collected by the photodetector 270. For example... Figure 2 As shown, the signal from photodetector 270 is then directed to signal conditioning and processing system 272, where the detection and intensity assessment of the plasma event are determined. Specifically, in some embodiments, the signal from photodetector 270 is directed to amplifier 274, where it is amplified. Thus, the amplified signal is used, for example, within control electronics 278, to determine the intensity of the plasma event occurring in the balloon fluid 132 within the balloon interior 146.

[0092] Furthermore, in some embodiments, the pulse from the amplified photodetector signal is gated using a discriminator 276 (e.g., discriminator circuitry), which is triggered by a pulse from the pulse generator 260. This information can then be used (e.g., within control electronics 278) to determine when a plasma event occurs in the balloon fluid 132 within the balloon interior 146. More specifically, control electronics 278 can compare the timing of the raw energy pulse from energy source 224 triggered by pulse generator 260 with the timing of the amplified photodetector signal gated using discriminator 276 to determine when a plasma event occurs in the balloon fluid 132 within the balloon interior 146.

[0093] In some embodiments, the control electronics 278 of the signal conditioning and processing system 272 may be included as a system controller 126 (e.g., Figure 1 (as shown) is part of the signal conditioning and processing system 272. Alternatively, the control electronics 278 of the signal conditioning and processing system 272 may be provided independently of the system controller 126 and may be electrically connected to the system controller 126.

[0094] It is to be understood that the photodetector 270 and the signal conditioning and processing system 272 have many other configurations required to detect and analyze the light pulses returning from the light guide 222A, i.e., the return energy beam 224C. For example, in another embodiment, the photodetector 270 may be a spectrometer that provides information about the intensity and wavelength of the return energy beam 224C. In such an embodiment, this information can be used to generate a spectral signature to further identify specific conditions or events in the light guide 222A and / or the plasma generator 264. More specifically, a small amount of material constituting the plasma generator 264 will vaporize during its normal operation. These will produce a distinct spectral line. It is also to be understood that this method can also be used to distinguish a normally functioning plasma generator 264 from a broken or damaged light guide 222A.

[0095] As described in detail herein, the primary mechanism of the invention is the direct detection of light pulses generated by plasma events in the balloon fluid 132 within the balloon interior 146. A signal conditioning and processing system 272 can be used to indicate the intensity of the light pulse, the spectrum of the light pulse, and when the light pulse occurs relative to an input pulse from the energy source 224. This can be interpreted as:

[0096] 1) The light pulse must occur after a time interval determined by the length of the light guide 222A and the duration of the input energy pulse from the energy source 224. If the detected light pulse has the correct intensity and occurs within a specific time window, it indicates that the plasma generator 264 is operating correctly.

[0097] 2) If no light pulse is detected at all, it indicates a device malfunction.

[0098] 3) If a smaller light pulse is detected that appears prematurely relative to the energy pulse from energy source 224, this will be an indication of a malfunction in light guide 222A.

[0099] 4) If a light pulse is detected to have a different spectrum or lacks spectral lines or features, this can be used to indicate a device malfunction.

[0100] Figure 3 This is a simplified schematic diagram of a portion of another embodiment of the catheter system 300, which includes an optical analyzer assembly 342. The design of the catheter system 300 is substantially similar to the embodiments shown and described above. It is to be understood that, for clarity and ease of illustration, various components of the catheter system 300 (such as...) Figure 1 (As shown), not in Figure 3As shown in the diagram. However, it should be understood that the catheter system 300 will likely include most (if not all) of such components.

[0101] like Figure 3 As shown, the conduit system 300 again includes an energy source 324, which is configured to generate light energy in the form of a light source beam 324A (e.g., a pulsed light source beam), which can be selectively and / or alternatively directed to each light guide 322A. Figure 3 Only one light guide is shown in the diagram, and each light guide 322A receives it as a separate guide beam 324B. In a non-exclusive embodiment, the energy source 324 is an infrared laser source, while the light guide 322A is a small-diameter multimode fiber. In some embodiments, the energy source 324 may again be configured to provide submillisecond energy pulses as the light source beam 324A, and then focus it onto a small spot, for example, using optical element 362, so as to couple it as a separate guide beam 324B into the guide proximal end 322P of the light guide 322A.

[0102] Subsequently, a separate guide beam 324B propagates along and / or through the light guide 322A and excites the plasma generator 364, which is positioned and / or contained at or near the guide distal end 322D of the light guide 322A. The plasma generator 364 utilizes infrared energy pulses in the balloon 104 (e.g., Figure 1 The interior of the balloon (as shown) 146 (as shown) Figure 1 The balloon fluid 132 (as shown) inside the balloon (as shown) Figure 1 Local plasma is generated in (as shown).

[0103] As described in detail herein, the optical analyzer assembly 342 is again configured to effectively monitor the performance, reliability, and safety of the conduit system 300 (e.g., the optical guide 322A and the plasma generator 364) by optically analyzing the light energy emitted from the guide proximal end 322P of the light guide 322A. However, in Figure 3 In the illustrated embodiment, the optical analyzer assembly 342 has a design different from that of the previous embodiment. More specifically, in this embodiment, instead of detecting and analyzing the light pulses emitted from the damaged section of the plasma or light guide as a return energy beam 224C (such as...),... Figure 2 Instead of using a separate second energy source 380, such as a second light source, to interrogate the light guide 322A (as shown), this method is similar to optical time domain reflectance (OTDR) used to detect faults in long fiber optic transmission lines.

[0104] Specifically, in Figure 3In the illustrated embodiment, the optical analyzer assembly 342 includes one or more of a second energy source 380, a pulse generator 382, ​​a beam splitter 366, an optical element 368 such as a coupling lens, a second beam splitter 384, a photodetector 370, and a signal conditioning and processing system 372. Furthermore, as shown, the signal conditioning and processing system 372 may include one or more of an amplifier 374, a discriminator 376, and control electronics 378, which may include one or more processors or circuits. Optionally, in other embodiments, the optical analyzer assembly 342 and / or the signal conditioning and processing system 372 may include more or fewer components than specifically shown and described herein.

[0105] like Figure 3 As shown in the illustrated embodiment, pulse generator 382 is coupled to a second energy source 380, wherein pulse generator 382 is configured to trigger the second energy source 380, which thus emits energy pulses as an interrogation beam 380A. In a non-exclusive embodiment, the second energy source 380 is a high-intensity, visible-wavelength laser, and pulse generator 382 is used to generate short, high-intensity pulses from the second energy source 380. The interrogation beam 380A is initially directed to a second beamsplitter 384, which, as described herein, can be used to generate separate source and return paths for the second energy source 380. In one embodiment, second beamsplitter 384 is a conventional beamsplitter with a high reflectance-to-transmittance ratio. This allows a small but sufficient amount of optical energy to be coupled into the light guide 322A.

[0106] Furthermore, in some embodiments, the interrogation beam 380A from the second energy source 380 then passes through the optical element 368 and is redirected by the beam splitter 366, such as a dichroic beam splitter, to the guide proximal end 322P of the light guide 322A. The interrogation beam 380A then propagates along and / or through the length of the light guide 322A. The interrogation beam 380A will be scattered or reflected by the plasma generator 364 at or near the guide distal end 322D of the light guide 322A and return to the guide proximal end 322P. The same optical path is then used to collect and detect the returned light pulses, i.e., the returned interrogation beam 380B.

[0107] like Figure 3As shown, the returned interrogation beam 380B is optically analyzed using the optical analyzer assembly 342. More specifically, as shown, the beam splitter 366 and optical element 368 are again used to separate the light energy emitted from the guide proximal end 322P of the light guide 322A and returning through the light guide 322A, i.e., the returned interrogation beam 380B. Subsequently, the returned interrogation beam 380B is guided to the second beam splitter 384. As described above, the second beam splitter 384 can have a high reflectance-to-transmittance ratio, which allows the collection and detection of weak reflected pulses from the light guide 322A in the form of the returned interrogation beam 380B. Therefore, the portion of the returned interrogation beam 380B reflected by the second beam splitter 384 can be collected and coupled into the photodetector 370. With this design, the optical element 368 effectively images the guide proximal end 322P of the light guide onto the photodetector 370, thereby coupling the light energy emitted from the guide proximal end 322P of the light guide 322A (i.e., in the form of the returning interrogation beam 380B) to the photodetector 370.

[0108] Additionally, in some embodiments, the photodetector 370 generates a signal based on a portion of the returned interrogation beam 380B that has already been collected by the photodetector 370. For example... Figure 3 As shown, the signal from photodetector 370 is then directed to signal conditioning and processing system 372, where the detection of a plasma event is determined. In some embodiments, the signal from photodetector 370 is directed toward amplifier 374, where the signal from photodetector 370 is amplified. Furthermore, in some embodiments, a discriminator 276 (e.g., a discriminator circuit triggered by a pulse from pulse generator 382) is used to gate the pulse from the amplified photodetector signal. This information can then be used, for example, within control electronics 378, to determine when and whether a plasma event occurs in the balloon fluid 132 within balloon interior 146. More specifically, control electronics 378 can compare the timing of the raw energy pulse from second energy source 380 triggered by pulse generator 382 with the timing of the electronic pulse from the amplified photodetector signal gated using discriminator 376 to indicate the position where the interrogation pulse returns along light guide 322A, i.e., as the returning interrogation beam 380B. This can be adjusted to determine whether the returning interrogation beam 380B originates from the plasma generator 364, which will be the maximum time difference between the trigger pulse and the return pulse. Conversely, a shorter time interval between the trigger pulse and the return pulse will indicate that the return is closer to the proximal end 322P of the optical guide 322A, which will indicate a failure or damage to the optical guide.

[0109] In some embodiments, the control electronics 378 of the signal conditioning and processing system 372 may be included as a system controller 126 (e.g., Figure 1 (as shown) is part of the signal conditioning and processing system 372. Alternatively, the control electronics 378 of the signal conditioning and processing system 372 may be provided independently of the system controller 126 and may be electrically connected to the system controller 126.

[0110] As described above, the optical analyzer assembly of the present invention addresses several potential problems in performance, reliability, and safety of IVL catheters, particularly those that utilize an energy source (e.g., a light source such as a laser) to generate localized plasma (which in turn induces high-energy bubbles in the balloon fluid inside the balloon). For example, as described above, the problems addressed by the present invention include, but are not limited to: (1) optical detection of successful excitation of the energy source and / or plasma generator to generate plasma inside the balloon; (2) accurate determination of the energy output of the plasma generator; (3) optical detection of failures in catheter systems (e.g., plasma generators) that fail to generate the desired plasma inside the balloon; and (4) optical detection of failures of the optical guide within the plasma generator, inside the balloon, or along any part of the catheter axis.

[0111] It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references, unless the content and / or context clearly indicate otherwise. It should also be noted that the term “or” is generally used to mean “and / or”, unless the content or context clearly indicates otherwise.

[0112] It should also be noted that, as used in this specification and the appended claims, the phrase “configuration” describes a system, device, or other structure constructed or configured to perform a particular task or employ a particular configuration. The phrase “configuration” may be used interchangeably with other similar phrases, such as arrangement and configuration, construction and arrangement, construction, manufacture and arrangement, etc.

[0113] The headings used herein are for the purpose of aligning with the recommendations under 37 CFR 1.77 or otherwise providing organizational clues. These headings should not be construed as limiting or characterizing any of the inventions (one or more) listed in any of the claims of this disclosure. As an example, the description of the technology in the “Background” section does not acknowledge that the technology is prior art to any invention in this disclosure. Nor should the “Summary” or “Abstract” be considered as features of the invention (one or more) described in the published claims.

[0114] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the detailed description provided herein. Rather, the embodiments were chosen and described to enable others skilled in the art to recognize and understand the principles and practices. Therefore, various aspects have been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications can be made while remaining within the spirit and scope of this document.

[0115] It should be understood that although many different embodiments of the catheter system have been described and illustrated herein, 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 invention.

[0116] While many exemplary aspects and embodiments of the catheter system have been discussed above, those skilled in the art will recognize certain modifications, variations, additions, and sub-combinations thereof. Therefore, the appended claims and the claims described below are intended to be construed as encompassing all such modifications, substitutions, additions, and sub-combinations within their true spirit and scope, and are not intended to limit the details of the structures or designs shown herein.

Claims

1. A catheter system for treating a treatment site in or near a blood vessel wall or heart valve, the catheter system comprising: A light source that generates light energy; A balloon capable of being positioned substantially adjacent to the treatment site, the balloon having a balloon wall defining an interior of the balloon, the interior of the balloon receiving balloon fluid; A light guide is configured to receive light energy from the light source at a proximal end of the guide and guide the light energy such that the light energy from the light source moves through the light guide in a first direction from the proximal end of the guide toward the distal end of the guide located inside the balloon to generate plasma in the balloon. The light guide is configured to subsequently guide a portion of the light energy from the plasma back through the light guide to the proximal end of the guide in a second direction opposite to the first direction. The portion of the light energy returning to the proximal end of the guide in the second direction is emitted by the plasma generated in the balloon fluid. and An optical analyzer assembly configured to optically analyze the light energy from the plasma that is moved back by the light guide in the second direction.

2. The catheter system according to claim 1, wherein, Fluid is supplied into the balloon, causing the balloon to inflate from a contracted configuration to an inflated configuration.

3. The catheter system according to any one of claims 1-2, wherein, The light source generates light pulses, which are guided along the light guide into the interior of the balloon to induce plasma generation in the balloon fluid inside the balloon.

4. The catheter system according to any one of claims 1-2, further comprising a plasma generator located at the distal end of the guide of the light guide, the plasma generator being configured to generate plasma in the balloon fluid inside the balloon.

5. The catheter system according to claim 3, wherein, The plasma generation causes bubbles to form rapidly and apply pressure waves to the balloon wall adjacent to the treatment site.

6. The catheter system according to claim 3, wherein, The optical analyzer assembly is configured to optically detect whether plasma generation has occurred in the balloon fluid inside the balloon.

7. The catheter system according to claim 3, wherein, The optical analyzer assembly is configured to optically detect whether insufficient plasma generation is occurring in the balloon fluid inside the balloon.

8. The catheter system according to any one of claims 1-2, wherein, The optical analyzer assembly is configured to optically detect faults in the light guide at any point along the length of the light guide from the proximal end to the distal end of the light guide.

9. The catheter system according to any one of claims 1-2, wherein, The optical analyzer assembly is configured to optically detect damage to the light guide at any point along the length of the light guide from the proximal end to the distal end of the light guide.

10. The catheter system according to claim 9, wherein, The optical analyzer assembly is configured to automatically shut down the operation of the conduit system when optical detection indicates damage to the light guide.

11. The catheter system according to any one of claims 1-2, wherein, The distal end of the guide includes a distal light receiver that receives a portion of the light energy passing through the light guide from the distal end to the proximal end of the guide as a return energy beam.

12. The catheter system according to claim 11, wherein, The portion of the light energy received by the light guide from the distal end to the proximal end of the guide is emitted from plasma generated in the balloon fluid inside the balloon.

13. The catheter system according to claim 11, wherein, The portion of the light energy received by the light guide from the far end of the guide to the near end of the guide via the far-side light receiver is optically analyzed by the optical analyzer assembly.

14. The conduit system according to any one of claims 1-2, further comprising a pulse generator coupled to the light source, the pulse generator being configured to trigger the light source to emit a light energy pulse guided along the light guide from the proximal end of the guide to the distal end of the guide.

15. The catheter system according to claim 14, wherein, The light energy pulse excites a plasma generator located at the distal end of the light guide, the plasma generator being configured to generate plasma in the balloon fluid inside the balloon.

16. The catheter system according to claim 1, wherein, A second portion of the light energy from the light source is guided back as a return energy beam in the second direction by the light guide, and the optical analyzer assembly is configured to optically analyze the return energy beam to determine whether plasma generation has occurred in the balloon fluid inside the balloon.

17. The catheter system of claim 16, wherein, The optical analyzer assembly includes a beam splitter and a photodetector; and wherein the beam splitter is configured to receive the returned energy beam and direct at least a portion of the returned energy beam onto the photodetector.

18. The conduit system of claim 17, further comprising an optical element positioned along the beam path between the beam splitter and the photodetector, the optical element being configured to couple at least a portion of the returned energy beam to the photodetector.

19. The catheter system according to claim 17, wherein, The photodetector generates a signal based at least in part on visible light contained in at least a portion of the returned energy beam.

20. The catheter system of claim 19, wherein, The signal from the photodetector is amplified by an amplifier to provide an amplified signal, which is directed to control electronics to determine the intensity of plasma generation in the balloon fluid inside the balloon.

21. The catheter system of claim 20, wherein, The amplified signal is selected using a discriminator circuit; and wherein the control electronics compares the timing of a light energy pulse from the light source triggered by a pulse generator with the timing of the amplified signal from the photodetector to determine when plasma generation occurs in the balloon fluid inside the balloon.

22. The catheter system according to any one of claims 1-2, wherein, The light source includes a laser.

23. The catheter system according to any one of claims 1-2, wherein, The light source includes an infrared laser that emits light energy in the form of infrared light pulses.

24. The catheter system according to any one of claims 1-2, wherein, The optical guide includes an optical fiber.

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