Systems and methods for diode laser-induced calcium disruption

Abstract

Devices, systems, and methods for disrupting calcium in a patient's artery. Some embodiments include a diode laser light source and an optical fiber. In specific embodiments, the optical fiber includes a polymer or glass optical core and a cladding surrounding the polymer or glass optical core. The optical fiber can include one or more radiating elements configured to emit electromagnetic energy from the laser light source. The electromagnetic energy can be transmitted through a fluid in the expandable member to disrupt the calcium. TIFF2026503064000003.tif75157

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 479,123, filed January 9, 2023, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Background information Coronary and peripheral arterial calcification (CPAC) complicates percutaneous coronary intervention (PCI) by reducing vascular compliance, impeding device delivery, impairing balloon dilation, and potentially resulting in uneven drug distribution in the arterial wall. Furthermore, CPAC causes damage to drug-eluting polymers, resulting in more procedural failures. Reduced vascular compliance also reduces the ability of implanted stents to expand, leading to stent failure through underexpansion, occasionally resulting in complications such as stent thrombosis and restenosis. Calcium location (superficial or deep), distribution (regional, circumferential, or longitudinal expansion), and thickness also adversely affect procedural time and success. CPAC is an independent predictor of poorer survival after PCI and is strongly correlated with major adverse cardiovascular events (MACE) after PCI.

[0003] Current clinical solutions for increasing vascular compliance and addressing excess calcium include high-pressure balloon dilation and calcium scoring using a cutting balloon. However, these approaches are often unsuccessful because they cannot completely remove calcium and are only applicable to superficial calcium. Coronary atherectomy using both rotational atherectomy systems (e.g., the Rotablator™) and orbital atherectomy are suitable for removing luminal superficial calcium. However, these approaches do not address deeper calcium and therefore do not always increase vascular compliance sufficiently to ensure complete stent expansion. These techniques are also technically complex and time-consuming, and may introduce increased risk by sending cut debris into the microcirculation, which can result in myocardial infarction during a no-reflow procedure. Therefore, addressing the calcium burden of atherosclerosis in a safe and effective manner is a major clinical challenge for interventional cardiologists.

[0004] Intravascular lithotripsy (IVL) techniques have been developed using electrical wires, electrodes, and electricity inside a balloon catheter. Current discharge induces vapor bubble formation, which generates acoustic pressure waves that travel through soft vascular tissue during collapse (microcavitation), selectively disrupting calcium within the vessel wall. The large difference in density and mechanical acoustic impedance characteristics between calcium and soft tissue allows the acoustic pressure to disrupt calcium while leaving the soft tissue intact. However, the use of current discharge limits the amount of available energy delivered to vaporize fluid and induce calcium disruption, as well as the ability to spatially and temporally control the energy delivery. The current discharge approach also results in large voltage spikes, which can pace the left ventricle with each delivered electrical pulse, which is not ideal. Numerous cases of ventricular fibrillation have been reported, as well as case reports of atrial fibrillation / flutter due to the delivered shock not being synchronized with the heart's intrinsic pacemaker. The size of the electrodes and wires also limits the miniaturization of the device. As a result, electric IVL devices are often larger in diameter than the residual lumen of many calcified lesions. Consequently, there are many instances in which rotational or orbital atherectomy is used solely to deliver the electric IVL device across the calcified lesion. Current current-discharge IVL devices are 12 mm long, while most coronary arteries are 100 mm long. The development of longer balloons for electric IVL requires the addition of more wires and electrodes, which further increases the diameter of the device. Therefore, systems and methods that overcome these and other limitations associated with existing electric IVL systems and methods are desirable. Summary of the Invention

[0005] overview There is a recognized urgent need for the ability to effectively disrupt intravascular calcium for the treatment of patient conditions, including atherosclerosis and other coronary diseases. Similarly, there is also a recognized need to decalcify heart valves and aortas. A catheter device for vascular insertion is described herein that uses a diode laser source that can be coupled to a small-diameter optical fiber to generate cavitation bubbles in a biocompatible fluid, which, upon collapse, generate shock waves that can propagate into the arterial wall. The optical fiber can be composed of polymer and / or glass, which differs from catheters that use near-infrared light, which are constructed from glass materials. A key element of our catheter device is the diode laser / biocompatible fluid combination, which enables the generation of large pressure amplitude shock waves (50 atm or greater). Indocyanine green is an FDA-approved biocompatible fluid that strongly absorbs at the emission wavelengths of diode lasers (e.g., 700 nm to 1000 nm). This particular diode laser / biocompatible fluid combination offers numerous practical advantages. First, the radiance of diode laser sources in the 700-1000 nm spectral range allows for the delivery of large pulse energies into small-diameter optical fibers (100-400 μm) that can be positioned inside arteries with small lumen diameters. Second, the large pulse energies propagating into the optical fiber do not generate any nonspecific electric or magnetic fields that could disrupt cardiac function. Third, diode lasers emitting light in the 700-1000 nm spectral range can propagate through polymer optical fibers, allowing for greater design flexibility for the optical radiation elements within the catheter. Fourth, diode laser sources emitting in the 700-1000 nm spectral range can be directly pulsed to provide optical radiation that allows precise temporal control over light emission time and pulse duration. Fifth, because ICG can absorb in the 700-1000 nm spectral range, diode laser sources allow for the incorporation of numerous radiation wavelengths that can be coupled into small-diameter optical fibers with multiple optical radiation-emitting elements.Furthermore, multiple optical emitting elements can each be selected for a specific diode laser emitter that can be controlled by sending current pulses to the appropriate diode emitting element. More specifically, the inventors disclose specific diode laser emitting wavelengths, pulse durations, and ICG formulations (concentrations and compositions) that, when combined together, unexpectedly generate large amplitude shock waves capable of disrupting calcium within the walls of coronary arteries.

[0006] Near-infrared pulsed lasers have been applied for decades to generate shock waves in saline solutions due to cavitation bubble generation and / or collapse. However, these lasers are typically expensive, bulky, and can only generate shock waves with limited pressure magnitude. Diode laser sources can offer many practical advantages for numerous medical treatment systems. Diode lasers provide photons at a high economic value—the economic cost per watt of radiation is lower than that of competing light sources, has decreased exponentially over the past few decades, and is expected to continue to decrease. Generating shock waves to disrupt calcium in arteries using diode laser sources can offer many important advantages. First, the radiance of diode laser sources allows for the delivery of large pulse energies into small-diameter (100 μm–1000 μm) optical fibers that can be positioned inside arteries with small lumen diameters. Second, the large pulse energies propagating into the optical fiber do not generate any nonspecific electric or magnetic fields that could disrupt cardiac function. More specifically, the electric field associated with the large pulse energy is confined to the optical fiber and does not extend outside the catheter, thus not interfering with surrounding tissues such as the heart. Third, diode lasers emit light that can propagate through polymer and / or glass optical fibers, allowing for greater design flexibility for the optical radiation element. Fourth, diode laser sources can be directly pulsed with current to provide optical radiation that allows for precise temporal control over the light emission time and pulse duration. Precise temporal control over the optical radiation allows for control over the generation / collapse of the resulting cavitation bubbles and the magnitude and direction of the corresponding shock wave pressure. Fifth, diode laser sources allow for the selection of numerous radiation wavelengths that can be tailored to the specific absorption profile of a candidate biocompatible fluid and directed to one of numerous optical radiation-emitting elements within the fiber catheter, which can be selected by sending a current pulse to the appropriate diode radiation element.

[0007] To date, no device has been developed that uses a diode laser source to generate shock waves in a biocompatible fluid and propagate them into biological tissue. The biocompatible fluid must be safe when injected into a human coronary artery. Preferably, the biocompatible fluid is one that has already been approved by a regulatory agency (e.g., the U.S. Food and Drug Administration) for injection into a coronary artery. In previous studies, saline solution has been the primary biocompatible fluid considered for generating shock waves inside an artery. In existing power source embodiments for generating shock waves, saline solution is the biocompatible fluid considered. In existing light source embodiments for generating shock waves in arteries, near-infrared laser sources that emit in the 1.9-2.1 μm spectral range and are strongly absorbed by water have been applied. The use of near-infrared laser sources for generating shock waves has many limitations. For example, when multiple shock wave emitters are desired, a multiplexing approach is used in which light from one laser source is sequentially multiplexed in space and time and sent to multiple optical fibers. What is needed is an economical diode laser source that can be coupled to a small diameter fiber optic catheter and a device that can use biocompatible fluids in which short pulses of light are injected into the fluid to generate cavitation bubbles whose collapse creates shock waves.

[0008] Exemplary embodiments of the present disclosure include an apparatus including a diode laser light source and an optical fiber including a polymer optical core; a cladding surrounding the polymer optical core; and a laser light emitting element. In some embodiments, the laser light emitting element is a first laser light emitting element in a plurality of laser light emitting elements. In specific embodiments, each of the plurality of laser light emitting elements is configured to emit light in the same wavelength range. In some embodiments, each of the plurality of laser light emitting elements is configured to emit light with the same power.

[0009] In certain embodiments, a first laser light emitting element of the plurality of laser light emitting elements is configured to emit light in a first wavelength range, and a second laser light emitting element of the plurality of laser light emitting elements is configured to emit light in a second wavelength range, the first wavelength range being different from the second wavelength range. In certain embodiments, an optical grating within an optical fiber comprises a plurality of laser light emitting elements. In specific embodiments, the plurality of laser light emitting elements emit light radially from the optical fiber. In some embodiments, the plurality of laser light emitting elements are configured as a row of scattering centers along the polymer optical core of the optical fiber. In specific embodiments, the plurality of laser light emitting elements are configured as scattering centers offset from the polymer optical core and positioned at equal angles near the cladding. In certain embodiments, the plurality of laser light emitting elements are configured as one or more photonic crystal lattices including a plurality of scattering centers in the polymer optical core.

[0010] In specific embodiments, the plurality of laser light emitting elements includes N laser light emitting elements, and the laser light emitting elements are positioned radially around the optical fiber such that there is 360 / N degrees between each laser light emitting element in the plurality of laser light emitting elements. In some embodiments, the plurality of laser light emitting elements emit light radially 360 degrees around the optical fiber. In particular embodiments, the diode laser source is configured to emit laser light at a wavelength of approximately 690 nanometers (nm) to 900 nm. In some embodiments, the diode laser source can provide pulses of light of 50 nanoseconds to 150 microseconds. In specific embodiments, the radiation power propagating through the optical fiber is 100 watts (W) to 100 kilowatts (kW). In some embodiments, the polymer optical core comprises poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), polyacrylamide (PAM), or a transparent amorphous fluoropolymer. In particular embodiments, the polymer optical core comprises a transparent thermoplastic. In some embodiments, the transparent thermoplastic is poly(methyl methacrylate). In specific embodiments, the polymeric optical core comprises a silicon-based organic polymer. In some embodiments, the silicon-based organic polymer is polydimethylsiloxane. In particular embodiments, the polymeric optical core comprises a transparent amorphous fluoropolymer. In some embodiments, the polymeric optical core comprises a synthetic polymer.

[0011] Specific embodiments further include an expandable member. In some embodiments, the expandable member includes a lumen configured to receive an optical fiber. In certain embodiments, the expandable member contains a fluid. In some embodiments, the fluid surrounds the optical fiber, and the fluid absorbs light emitted by the diode laser light source. In specific embodiments, the fluid includes indocyanine green (ICG). In some embodiments, the fluid includes a solvent, and in certain embodiments, the concentration of ICG relative to the solvent is 5 milligrams per milliliter (mg / ml) to 25 mg / ml. In some embodiments, the solvent includes water, saline, or dextrose.

[0012] Specific embodiments further include a control system configured to control an operating parameter of the diode laser light source. In some embodiments, the operating parameter is a pulse duration, a wavelength frequency, a number of variable wavelength frequencies, or a wavelength amplitude of the diode laser light source. In certain embodiments, the control system is configured to provide a first laser light emission and a second laser light emission from the diode laser light source. In some embodiments, the first laser light emission is configured to generate gas bubbles in the fluid in the expandable member. In specific embodiments, the control system is configured to provide a second laser light emission from the diode laser light source upon collapse of the gas bubbles in the fluid in the expandable member.

[0013] In certain embodiments, the optical fiber comprises an imaging element, and in some embodiments, the imaging element is configured to provide intravascular ultrasound (IVUS) or optical coherence tomography (OCT) imaging data. In some embodiments, the diode laser source is a first diode laser source in a plurality of diode laser sources, and the optical fiber is a first optical fiber in a plurality of optical fibers. In specific embodiments, each diode laser source in the plurality of diode laser sources is coupled to a separate optical fiber in the plurality of optical fibers. In some embodiments, the optical fiber in the plurality of optical fibers comprises a conical distal end.

[0014] In certain embodiments, the optical fibers are coupled via a tapered fiber coupler. In some embodiments, the optical fibers are coupled via a lateral coupling region. In specific embodiments, the optical fibers are coupled via a sleeve coupling element, and at least one of the optical fibers includes an angled shiny end coated with a dielectric reflector.

[0015] Exemplary embodiments include a device comprising: a diode laser light source; and an optical fiber comprising an optical core; a cladding surrounding the polymer optical core; and a plurality of laser light emitting elements configured as emission centers within the optical core. In specific embodiments, the plurality of laser light emitting elements are configured as a row of scattering centers along the optical core of the optical fiber. In some embodiments, the plurality of laser light emitting elements are configured as scattering centers offset from the optical core and positioned at equal angles near the cladding. In particular embodiments, the plurality of laser light emitting elements are configured as one or more photonic crystal lattices comprising a plurality of scattering centers in the optical core. In some embodiments, the optical core is a polymer optical core, and in specific embodiments, the optical core is a glass optical core.

[0016] In certain embodiments, the diode laser source is a first diode laser source in a plurality of diode laser sources and the optical fiber is a first optical fiber in the plurality of optical fibers. In specific embodiments, each diode laser source in the plurality of diode laser sources is coupled to a separate optical fiber in the plurality of optical fibers. In some embodiments, the optical fiber in the plurality of optical fibers comprises a conical distal end.

[0017] In certain embodiments, the optical fibers are coupled via a tapered fiber coupler. In some embodiments, the optical fibers are coupled via a lateral coupling region. In specific embodiments, the optical fibers are coupled via a sleeve coupling element, and at least one of the optical fibers includes an angled shiny end coated with a dielectric reflector.

[0018] An exemplary embodiment includes a method of disrupting calcium in an artery, comprising the steps of: inserting into an artery an optical fiber coupled to a diode laser light source and comprising: a polymer optical core; a cladding surrounding the polymer optical core; and a laser light emitting element; inserting an expandable member into the artery; expanding the expandable member via a fluid in the expandable member; emitting electromagnetic energy from the laser light emitting element that generates pressure waves in the fluid contained within the expandable member; and disrupting the calcium in the artery via the pressure waves in the fluid.

[0019] In certain embodiments, the laser light emitting element is the first laser light emitting element of a plurality of laser light emitting elements. In specific embodiments, each of the plurality of laser light emitting elements is configured to emit light in the same wavelength range. In some embodiments, each of the plurality of laser light emitting elements is configured to emit light with the same power. In certain embodiments, a first laser light emitting element of the plurality of laser light emitting elements is configured to emit light in a first wavelength range; a second laser light emitting element of the plurality of laser light emitting elements is configured to emit light in a second wavelength range; the first wavelength range is different from the second wavelength range. In specific embodiments, a diffraction grating structure within the optical fiber comprises an element of each laser light emitting element. In some embodiments, the plurality of laser light emitting elements emit light radially from the optical fiber. In specific embodiments, the plurality of laser light emitting elements includes N laser light emitting elements, and the laser light emitting elements are positioned radially around the optical fiber such that there are 360 / N degrees between each laser light emitting element in the plurality of laser light emitting elements.

[0020] In certain embodiments, the plurality of laser light emitting elements emit light radially 360 degrees around the optical fiber. In specific embodiments, the diode laser light source is configured to emit laser light at a wavelength of approximately 690 nanometers (nm) to 900 nm. In some embodiments, the diode laser light source can provide pulses of light of 50 nanoseconds to 150 microseconds. In particular embodiments, the radiation power propagating through the optical fiber is 100 watts (W) to 100 kilowatts (kW). In specific embodiments, the polymer optical core comprises a synthetic polymer. In some embodiments, the polymer optical core comprises poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), polyacrylamide (PAM), or a transparent amorphous fluoropolymer. In particular embodiments, the polymer optical core comprises a transparent thermoplastic. In some embodiments, the transparent thermoplastic is poly(methyl methacrylate). In specific embodiments, the optical fiber has a high numerical aperture (NA) so that the fiber diameter can be smaller for the required etendue (or optical throughput). The use of high NA fibers allows for a reduced device diameter, providing advantages for navigating highly stenosed arteries.

[0021] In specific embodiments, the polymeric optical core comprises a silicon-based organic polymer, and in some embodiments, the silicon-based organic polymer is polydimethylsiloxane. In certain embodiments, the polymeric optical core comprises a transparent amorphous fluoropolymer. In some embodiments of the method, the fluid comprises indocyanine green (ICG). In specific embodiments, the fluid comprises a solvent, and in some embodiments, the concentration of ICG relative to the solvent is 5 milligrams per milliliter (mg / ml) to 25 mg / ml. In certain embodiments, the solvent comprises water, saline, or dextrose.

[0022] In some embodiments, the expandable member includes a lumen, and the optical fiber extends through the lumen of the expandable member. In specific embodiments of the method, the optical fiber includes an imaging element. In some embodiments, the imaging element is configured to provide intravascular ultrasound (IVUS) or optical coherence tomography (OCT) imaging. In certain embodiments, the imaging element provides imaging data during: inserting the optical fiber into the artery; inserting the expandable member into the artery; expanding the expandable member via fluid in the expandable member; emitting electromagnetic energy from a laser light emitting element; or fracturing calcium in the artery via pressure waves in the fluid. In some embodiments, the imaging element provides imaging data after fracturing calcium in the artery via pressure waves in the fluid.

[0023] In the following disclosure, the term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically.

[0024] The use of the word "a" or "an," when used in conjunction with the word "comprising" in the claims and / or specification, can mean "one," but is also consistent with the meaning of "one or more" or "at least one." The terms "about" and "approximately" generally mean the stated value plus or minus 5%. The use of the word "or" in the claims is used to mean "and / or" unless expressly indicated to refer to alternatives only or unless the alternatives are mutually exclusive, however, the present disclosure supports a definition that refers to alternatives only and "and / or."

[0025] The terms "comprise" (and any form of comprise, e.g., "comprises" and "comprising"), "have" (and any form of have, e.g., "has" and "having"), "include" (and any form of include, e.g., "includes" and "including"), and "contain" (and any form of contain, e.g., "contains" and "containing") are open-ended linking verbs. Consequently, a method or device that "comprises," "has," "includes," or "contains" one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Similarly, a method step or device element that "comprises," "has," "contains," or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure configured in a certain way is configured in at least that way, but may also be configured in ways not recited.

[0026] Other objects, features, and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and specific examples, while indicating particular embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. [Brief explanation of the drawings]

[0027] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0028] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present disclosure. The invention may be better understood by reference to one of these drawings in combination with the detailed description of specific embodiments presented herein.

[0029] [Figure 1] 1 shows a schematic diagram of an artery with a guidewire for use with a device according to an exemplary embodiment. [Figure 2] 1 shows a schematic diagram of an exemplary embodiment according to the present disclosure during an early stage of use. [Figure 3] 2 shows a schematic diagram of a portion of the embodiment of FIG. 1 in use. [Figure 4] 2 shows a schematic diagram of a portion of the embodiment of FIG. 1 in use. [Figure 5] 1 shows a schematic end view of an exemplary embodiment according to the present disclosure. [Figure 6] 1 illustrates a radiating element including a beveled surface within an optical fiber. [Figure 7] 1 shows a radiating element including an optical grating. [Figure 8] 1 shows a radiating element including an embedded optical guide. [Figure 9] 1 shows a radiating element configured as a row of scattering centers along the central region of a core in an optical fiber. [Figure 10] A radiating element 150 configured as a scattering center located at an offset from the core and positioned at an equivalent angle near the cladding of the optical fiber is shown. [Figure 11] 1 shows a radiating element configured as a photonic crystal lattice containing multiple scattering centers arranged in a designed spatial configuration. [Figure 12] 10 shows a graph of pressure generated by an exemplary embodiment according to the present disclosure. [Figure 13]1 shows a graph of molar extinction coefficient versus wavelength according to an exemplary embodiment of the present disclosure. [Figure 14] 1 shows a graph of molar extinction coefficient versus wavelength for different fluid combinations and concentrations including indocyanine green [ICG] according to an exemplary embodiment of the present disclosure. [Figure 15] See legend to Figure 14. [Figure 16] See legend to Figure 14. [Figure 17] See legend to Figure 14. [Figure 18] See legend to Figure 14. [Figure 19] Illustrates data obtained in indocyanine green [ICG] precipitation studies for different fluid combinations and concentrations containing ICG. [Figure 20] See legend to Figure 19. [Figure 21] See legend to Figure 19. [Figure 22] See legend to Figure 19. [Figure 23] See legend to Figure 19. [Figure 24] Data is illustrated by emitting a second pulse of electromagnetic energy timed to occur upon the collapse of the vapor bubble generated by the first pulse of electromagnetic energy. [Figure 25] See legend to Figure 24. [Figure 26] See legend to Figure 24. [Figure 27] See legend to Figure 24. [Figure 28] See legend to Figure 24. [Figure 29] See legend to Figure 24. [Figure 30] 1 illustrates a block diagram of a system utilizing multiple diode lasers combined into a single fiber and then split into different fibers for each emitter. [Figure 31]1 illustrates a block diagram of a system that uses a separate small-core high-NA fiber coupled to each diode and emitter. [Figure 32] 1 illustrates an end cross-sectional view of one embodiment of an IVL catheter including multiple optical fibers distributed around a central guidewire. [Figure 33] 1 illustrates an optical fiber configured to redirect laser light radiation. [Figure 34] 1 illustrates an end cross-sectional view of one embodiment of an IVL catheter comprising multiple optical fibers distributed around a central guidewire with openings in the outer coil. [Figure 35] 1 illustrates a schematic cross-sectional view of an IVL catheter including multiple optical fibers within an expandable member. [Figure 36] 1 illustrates a partial cross-sectional view of an embodiment of a tapered fiber coupler configured for use in an IVL catheter. [Figure 37] 1 illustrates a partial cross-sectional view of an embodiment of a side-coupled fiber configured for use in an IVL catheter. [Figure 38] 1 illustrates a partial cross-sectional view of an embodiment of an in-line reflector made from a dielectric film configured for use in an IVL catheter. DETAILED DESCRIPTION OF THE INVENTION

[0030] DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Exemplary embodiments of the present disclosure include devices and methods for disrupting arterial calcium, including, for example, calcium in coronary arteries. Referring initially to FIGS. 1-4, an overview of an exemplary device 100 and method of use is clearly shown. For purposes of clarity, not all features shown in each figure are labeled with a reference number. In the illustrated embodiment, device 100 includes a diode laser source 110 coupled to an optical fiber 120 and a control system 130. Control system 130 can be configured to control operational parameters of device 100, including, for example, operation of diode laser source 110 (e.g., laser pulse duration, frequency, amplitude, etc.) during a calcium disruption procedure.

[0031] In FIG. 1 , optical fiber 120 of device 100 is inserted into artery 250, with calcium 270 located within artery 250. In FIGS. 1-4 , artery 250 and a portion of optical fiber 120 are shown in cross-section. As discussed more fully below, optical fiber 120 includes an optical core 121 and a polymer cladding 122 surrounding optical core 121. In addition, optical fiber 120 includes one or more laser light emitting elements 150. In exemplary embodiments of the present disclosure, optical fiber 120 is positioned within artery 250 such that laser light emitting element 150 is in close proximity to calcium 270 (e.g., optical fiber 120 is inserted into artery 250 a sufficient distance so that laser light emitting element 150 is generally aligned with calcium 270). In specific embodiments, optical fiber 120 may include an imaging element 123 to assist in positioning optical fiber 120. In certain embodiments, imaging element 123 may be configured to provide intravascular ultrasound (IVUS) and / or optical coherence tomography (OCT) imaging. In certain embodiments, polymer cladding 122 may include poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), polyacrylamide (PAM), or a transparent amorphous fluoropolymer (e.g., Cytop™). It is understood that other embodiments of the present disclosure may include polymer claddings having different polymers than those enumerated herein.

[0032] In FIG. 2 , an expandable member 300 (e.g., a balloon catheter) is inserted into an artery 250. In certain embodiments, the optical fiber 120 can function in a manner equivalent to a typical guidewire to facilitate insertion of the expandable member 300. For example, in the embodiment shown, the expandable member 300 includes a lumen 310 configured to receive the optical fiber 120 so that the optical fiber 120 can be used to guide the expandable member 300 to a desired location within the artery 250. In addition, the optical fiber 120 includes a distal end 129 having a formable or moldable portion 128. In specific embodiments, the formable portion 128 can be formed from a nickel-titanium alloy (e.g., Nitinol) wire or other suitable configuration, including, for example, a workhose tip available from Asahi ©. In an exemplary embodiment, the distal end 129 can be coupled to the optical fiber 120 via polyethylene microtubing or another suitable structure. Existing imaging technology can also be used to assist in the placement of the expandable member 300. In a specific embodiment, the imaging element 123 can be used to aid in positioning the expandable member 300 relative to the optical fiber 120 and the calcium 270. Thus, the expandable member 300 can be positioned within the artery 250 in a manner familiar to the surgeon to allow precise placement at the desired location adjacent the calcium 270.

[0033] 3, expandable member 300 is expanded within artery 250 via fluid 320, which may include, for example, a fluid containing indocyanine green (ICG). In specific embodiments, fluid 320 may include ICG and a solvent. In certain embodiments, the solvent may include a mixture of one or more of saline, dextrose, and / or water. Expandable member 300 can be expanded by increasing the pressure of fluid 320 within expandable member 300.

[0034] In the embodiment shown in FIG. 3, the expandable member 300 is expanded after the expandable member 300 is inserted into the artery 250 (as shown in FIG. 2) and before emitting electromagnetic energy 170 from the laser light emitting element 150 (as shown in FIG. 4). The electromagnetic energy 170 creates cavitation (e.g., bubbles 330) in the fluid 320, which generates ultrasound waves 340 from the formation and collapse of the bubbles 330 in the fluid 320. In one embodiment, a diffraction grating structure within the optical fiber 120 comprises the laser light emitting element 150. In one embodiment, the expandable member 300 can be configured as a balloon configured for treatment of the distal aorta to increase aortic compliance and elastic recoil during diastole to improve blood flow to the microcirculation in elderly patients with resistant systolic hypertension.

[0035] As shown in FIG. 4 , ultrasound waves 340 propagate through fluid 320, creating fractures 280 only in calcium 270 without damaging the vessel wall of artery 250. This is because the vessel wall is more elastic than calcium plaque. In exemplary embodiments, fractures 280 are created along heterogeneities in calcium 270 and / or at the calcium-hard-soft tissue interface. The fractures in calcium 270 increase the compliance of artery 250, allowing artery 250 to expand and contract more easily with changes in pressure. In certain embodiments, imaging element 123 can be used to monitor the fractures in calcium 270.

[0036] In specific embodiments, the elements of device 100 are specifically selected to improve the ability to create spalls 280 in calcium 270 while reducing the power requirements from diode laser source 110 and reducing the manufacturing costs of device 100. For example, laser source 110 and fluid 320 can each be selected to maximize the amount of energy provided by ultrasound 340 while minimizing the power requirements from diode laser source 110. In specific embodiments, the operating parameters of laser source 110 (e.g., wavelength of electromagnetic energy 170, pulse duration, etc.) and the concentration of ICG in fluid 320 can be selected to optimize the efficiency of device 100 (e.g., the ability to create spalls 280 in calcium 270 for a given power requirement of laser source 110).

[0037] Furthermore, in particular embodiments, optical fiber 120 may be formed from fiber that is significantly less costly than fiberglass. In particular embodiments, optical fiber 120 may be formed from fiber material that costs approximately $0.10 per meter, significantly reducing manufacturing costs for device 100.

[0038] A close-up view of one embodiment of distal tip 129 is shown in the partial cross-sectional schematic diagram of FIG. 5. As shown in the figure, moldable portion 128 includes a tapered core material 127. In certain embodiments, tapered core material 127 may be formed from a metal alloy of nickel and titanium (e.g., nitinol). Additionally, optical fiber 120 is shown with radiating elements 150 radially arranged at both 90 degrees and 180 degrees from each other to provide radiation of electromagnetic energy around the circumference of optical fiber 120. It is understood that the configuration of radiating elements shown in the figures is exemplary, and other configurations of radiating elements may be utilized in accordance with embodiments of the present disclosure. For example, radiating elements 150 may be arranged at 60, 45, 30 degrees (or other configurations as desired) around the circumference of optical fiber 120. In certain embodiments, radiating elements 150 may be arranged to radiate electromagnetic energy 360 degrees around the circumference of optical fiber 120.

[0039] Exemplary embodiments of the present disclosure may include one or more configurations of radiating element 150. Figure 6 illustrates a close-up view of the radiating element 150 illustrated in Figures 1-4. In the embodiment shown in Figure 6, the radiating element 150 includes one or more beveled surfaces 151 within the optical fiber 120. In some embodiments, the radially radiating fiber includes a single wedge-shaped surface that acts as both a reflector and a refractive element, as shown in Figure 6. Wedge-shaped surfaces can be chained along the length of the optical fiber to achieve multiple radiating elements.

[0040] In the embodiment shown in FIG. 7, the optical fiber 120 includes a radiating element 150 that includes a fiber grating 152 and an optional lens element 153. In the embodiment shown in FIG. 8, the radiating element 150 includes an optical guide 154 and an optical lens element 153. In an exemplary embodiment, the optical guide 154 has a higher refractive index than the optical fiber 120. In some embodiments, the optical guide 154 can be configured as an orthogonal waveguide. The optional lens 153 in FIGS. 7 and 8 can focus electromagnetic energy into a biocompatible fluid in the expandable member surrounding the optical fiber 120 (e.g., electromagnetic energy 170 shown in FIG. 4 into fluid 320 within expandable member 300). In some embodiments, a dielectric grating can be written into the fiber, designed to couple light of a selected wavelength out of the fiber into a surrounding biocompatible absorbing fluid. Waveguides can be written into the fiber to couple out radiation from the core by creating regions of higher refractive index. Higher refractive index waveguide regions can be created by first removing material from the fiber using a subtractive manufacturing process and then filling it with a higher refractive index synthetic polymer.

[0041] In exemplary embodiments of the present disclosure, directing light from an optical fiber into a surrounding biocompatible absorbing fluid is accomplished using one or more emitting elements configured as optical emitters embedded in the optical fiber. An exemplary embodiment of the optical emitter element includes a patterned refractive index gradient within the fiber core guiding structure of the optical fiber. In a specific embodiment, the function of the optical emitter element is to couple and direct light exiting the fiber core guiding structure into the surrounding biocompatible absorbing fluid. The patterned refractive index gradient embedded within the fiber core guiding structure can take many forms and may include one or more of: (1) a reflective surface; (2) a refractive surface; (3) a scattering center; (4) a dielectric diffraction grating; (5) an internal core waveguide; and / or (6) a photonic crystal lattice.

[0042] In specific embodiments, the refractive index of selected regions within the core of an optical fiber can be altered (increased or decreased) by directing focused radiation into the core of the optical fiber to create scattering centers. The scattering centers can have a higher or lower refractive index compared to the surrounding core in certain embodiments. Referring now to FIG. 9, one exemplary embodiment includes an optical fiber 120 having a cladding 122 surrounding an optical core 121 having radiating elements 150 configured as a row of scattering centers 155 along a central region of the core 121 of the fiber 120.

[0043] In the embodiment shown in FIG. 10 , optical fiber 120 includes a cladding 122 surrounding an optical core 121 with radiating elements 150 configured as scattering centers 156 located at offset locations from core 121 and positioned at equal angles near cladding 122. As shown in the end cross-sectional view on the left side of FIG. 10 , in this embodiment, six scattering centers 156 are equally spaced around the peripheral region of core 121 such that angle A between adjacent scattering centers 156 is approximately 60 degrees. While the embodiment shown in FIG. 10 includes six radially positioned scattering centers 156 arranged in a spiral or helical pattern along optical fiber 120, it will be understood that other embodiments may include a different number of radial positions and / or a different arrangement along the length of optical fiber 120. For example, an embodiment may include a different number of radial positions arranged linearly along the peripheral region of core 121.

[0044] In a specific embodiment, a photonic crystal lattice can be written into the core region of an optical fiber. Referring now to FIG. 11 , the radiating element 150 is configured as one or more photonic crystal lattices 157 containing multiple scattering centers 158 arranged in a designed spatial configuration. The photonic crystal lattice 157 can be generated, for example, by a focused laser beam to induce a localized phase transition or by scattering centers within the core of the optical fiber to create regions of altered refractive index. By scanning the beam focus laterally and / or longitudinally, the photonic crystal lattice 157 can be created at discrete longitudinal locations along the fiber core. For either patterned refractive index gradients embedded within the fiber core guide structure, curved refractive surfaces can be fabricated on the fiber or guidewire surface to focus the light that exits the core and is coupled into the surrounding biocompatible absorbing fluid.

[0045] Additionally, the absorbent biocompatible fluid in the expandable member can be configured to efficiently fracture calcium with respect to the applied electromagnetic energy. As the molar concentration of ICG increases in solution, the absorption coefficient also increases. However, this increase is not linear. Thus, even if a 1× concentration is 1 cm -1 However, 100x does not necessarily mean 100cm. -1 This is due to the "aggregation" effect of cyanine dyes. Cyanine dyes, including ICG, tend to aggregate at high concentrations in aqueous solution, which can reduce the absorption coefficient.

[0046] Lower aggregation implies less power is required to generate the same pressure. While dimethyl sulfoxide (DMSO) can be used to avoid aggregation in ex vivo applications, it is not biocompatible. Therefore, exemplary embodiments of the present disclosure can include other techniques, including, for example, dissolving dyes in liposomal nanodroplets. Additionally, exemplary embodiments of the present disclosure can utilize dextrose, plasma, albumin, and / or water in the solution to increase the absorption coefficient.

[0047] Data from one specific embodiment is shown in Figure 12. In this embodiment, a diode laser light source 110 is configured to emit electromagnetic energy 170 at a wavelength of 787 nanometers (with a narrow spectral bandwidth of less than 5 nanometers [nm]) with a pulse duration of approximately 50 μs. In the embodiment shown, the pulse energy is less than 15 millijoules (mJ). When directed into a fluid containing ICG at an ICG concentration of 25 milligrams per milliliter (mg / ml) (and optionally a solvent including, for example, water, saline, or dextrose), ultrasound waves 340 generated pressures in the fluid of greater than 50 bar.

[0048] FIG. 13 shows a graph illustrating the molar extinction coefficient (a measure of how strongly a chemical species or substance absorbs light at a particular wavelength) versus wavelength for different concentrations of ICG in water. Absorption at the laser wavelength (e.g., approximately 787 nm) is more than 10 times greater than the absorption of water at a laser wavelength of approximately 2 μm. In a specific embodiment, the diode laser light source 110 can be configured to emit electromagnetic energy at a wavelength near the maximum absorption coefficient for a specified concentration of ICG formulation in the expandable member 300. The use of a diode laser also provides a compact configuration and flexible pulse profile. Therefore, embodiments utilizing a diode laser can provide sufficient electromagnetic energy to the absorbent biocompatible fluid in the expandable member to effectively fracture calcium.

[0049] As previously mentioned, the contents of fluid 320 can be optimized to efficiently disrupt calcium with respect to the electromagnetic energy provided. In Figures 14-18, a BioDrop® μLITE+ spectrophotometer from BioChrom® was used to obtain data on the molar extinction coefficient versus wavelength for five different ICG solvent combinations at different concentrations. Specifically, the solvents included water, saline, water / saline (1:1), water / dextrose (1:1), and dextrose at ICG concentrations of 5, 12.5, and 25 mg / ml. As shown in the graphs, dextrose, alone or in combination with water, does not alter the absorption peak of ICG at concentrations of 5, 12.5, and 25 mg / ml.

[0050] Another factor to consider when determining a desired ICG formulation is the degree to which ICG precipitates from solution. Figures 19-23 illustrate data obtained over time in ICG precipitation studies for five different solvents at three different concentrations. Again, the solvents used to obtain the data in Figures 19-23 include water, saline, water / saline (1:1), water / dextrose (1:1), and dextrose, respectively. The precipitation data in Figures 19-23 were obtained using an Invitrogen™ Countess™ II cell counter at 37°C for 15 minutes, 2 hours, 4 hours, and 24 hours, using ICG concentrations in the solvent of 5 mg / ml, 12.5 mg / ml, and 25 mg / ml. The data in Figures 19-23 demonstrate that dextrose, alone or in combination with water, can be used to reconstitute ICG without precipitation within 5 hours of mixing.

[0051] Exemplary embodiments of the present disclosure can also be configured to provide continuous electromagnetic energy (e.g., laser light) radiation for a specific period of time to maximize the ability of the pressure wave created in the fluid to disrupt calcium in arteries. For example, certain embodiments can be configured to generate a first electromagnetic energy radiation that generates vapor bubbles in the fluid (e.g., ICG), where the vapor bubbles first expand and then collapse. Particular embodiments can also be configured to generate a second electromagnetic energy radiation that is emitted approximately simultaneously with the collapse of the bubbles generated from the first electromagnetic energy radiation. By timing the emission of the second electromagnetic energy pulse to occur when the vapor bubbles from the first electromagnetic energy radiation are collapsing, a larger pressure pulse can be created, enhancing the ability to disrupt calcium in arteries or other environments.

[0052] 24-29, data were collected from an embodiment emitting dual pulses of electromagnetic energy and compared with a similar embodiment emitting a single pulse of electromagnetic energy. Results were recorded for electromagnetic energy pulse durations of 10 μs, 20 μs, and 50 μs at 10 volts and 793 nm wavelength from an NLight® 1500 watt fiber laser. Data were collected using a pressure sensor approximately 13.73 mm from the fiber tip in a chamber pressurized to 4 bar and filled with a 50 / 50 mixture of ICG (5 mg / mL) and Visipaque™ solution.

[0053] Data for a single pulse was collected first to determine the delay between the laser pulse and the vapor bubble collapse. Single-pulse data were collected five times to determine the average delay between the laser pulse and the vapor bubble collapse, as well as the amplitude of the shock wave pressure. Dual-pulse data was collected by firing a second laser pulse at the average time delay observed between the laser pulse and the vapor bubble collapse in the single pulse. Data recorded for a 10 μs laser pulse is shown in FIGS. 24-25, while data for a 20 μs laser pulse is shown in FIGS. 26-27, and data for a 50 μs laser pulse is shown in FIGS. 28-29. As noted in each of the figures, the average pressure recorded for the dual-pulse embodiment was greater than that generated in the single-pulse embodiment. Pressure data was recorded in millivolts from the pressure transducer and converted to bar in the average calculation. Pressure data for the dual pulse embodiment was collected at 10 kHz, 11 kHz, and 11.68 kHz for the 10 μs embodiment, while data for the 20 μs embodiment was collected at 10 kHz and 11.36 kHz, and 10 kHz, 11.6 kHz, and 11.16 kHz for the 50 μs embodiment. The most significant difference was observed at 11.68 kHz for the 10 μs laser pulse embodiment, which provided an average pressure of 140.31 bar compared to 97.63 bar at 10 μs for the single pulse embodiment.

[0054] Specific embodiments of the present disclosure may also include multiple optical fibers, where each optical fiber is coupled to a separate diode laser. Such embodiments can provide increased flexibility with the operating parameters of the laser light emission from the diode laser. For example, the use of multiple separate optical fibers, each coupled to an individual diode laser, can allow the user increased spatiotemporal control by emitting light from separate diode laser / optical fiber units in a way that may not be possible with a single laser (or multiple lasers) coupled to a single optical fiber.

[0055] The construction of a diode laser IVL catheter incorporating multiple optical fibers requires several considerations. Diode laser emitters provide a specified radiance (W / (sr area)) or watts per unit etendue. Laser IVL catheter specifications require many emitters, and each emitter in a laser IVL catheter must provide some minimum radiant power density (watts / area) to generate a shock wave. For example, for 5 mg / ml ICG, approximately 2 kW / mm 2 A typical minimum radiation power density of 0.05 is required for shock wave generation. One challenge with laser IVL catheter design centers around the distribution of source radiance (W / etendue) provided by the diode laser emitter into the catheter emitter. The optical etendue (ability to transmit light) of a fiber is a function of the core area and solid angle (NA). 2 ) is proportional to the product of

[0056] IVL catheter design considerations include compatibility with existing guidewires (e.g., 0.014" wire / 350 µm) and minimizing the overall catheter diameter. For laser IVL catheters, the diameter of each optical fiber contributes to the overall diameter of the laser IVL catheter. Therefore, the use of small core diameter / high numerical aperture (NA) optical fibers offers many important advantages. For example, a small core diameter allows the overall design diameter constraints of the laser IVL catheter to be met. In addition, fibers with a small core diameter provide increased radiant emittance (W / area) at the fiber tip. Furthermore, a high NA fiber increases the fiber etendue, which, for a given diode laser emitter, allows for more efficient coupling of the diode laser radiation emission into the fiber, allowing for more watts to be coupled into each fiber.

[0057] The use of a separate optical fiber for each diode laser can also reduce or eliminate the need for passive splitters / combiners (e.g., used to split or combine optical paths from one or more laser sources). A block diagram of a system utilizing multiple diode lasers combined into a single fiber and then split to a different fiber for each emitter is shown in Figure 30. Passive combiners / splitters can add cost and complexity to system design, and a configuration without a combiner / splitter can provide a simpler, less lossy, and more cost-effective system. With the use of passive combiners / splitters, all emitters coupled to a laser source emit radiation simultaneously, and triggering of individual emitters is not possible. Therefore, the use of small-core, high-NA fibers allows for direct coupling of individual laser diodes to each emitter, and the use of small-core, high-étendue fibers allows for efficient and fiber-specific generation of shock waves while maintaining a small-diameter laser IVL catheter. A block diagram of a system using separate small-core, high-NA fibers coupled to each diode and emitter is shown in Figure 31. In one embodiment, the small-core high-NA fiber can be a biocompatible Optran® Ultra WFGE-doped Si / Si fiber with a glass / glass / polyamide configuration for core / cladding / coating with diameters of 50 / 60 / 70 μm.

[0058] 32, an end cross-sectional view of one embodiment of an IVL catheter 500 is shown, including multiple optical fibers 501-507 distributed around a central guidewire 510. The optical fibers 501-507 and guidewire 510 are housed inside an outer sheath or coil 511. In certain embodiments, the optical fibers 501-507 can have an outer diameter of 70 μm, while the guidewire 510 can be approximately 0.004 inches in diameter and formed from stainless steel (e.g., 316, 304, or 302 stainless steel). In certain embodiments, the outer coil 511 can be approximately 0.002 inches thick with an overall diameter of approximately 0.0140 inches and can be configured to transmit torque to the catheter 500. It is understood that the dimensions of the components in this embodiment are merely exemplary, and that other embodiments of the present disclosure can include similar components with different dimensions.

[0059] As shown in FIGS. 33-34 , some embodiments can also be configured to redirect laser light radiation 512 through one or more apertures 513 within the outer coil 511. In some embodiments, the optical fiber (e.g., optical fiber 501) can include a conical, angled, tapered (or otherwise configured) distal end 515 to redirect the laser light radiation 512 via internal reflection. In some embodiments, the conical distal end 515 can be configured to provide laser light radiation 512 that generates symmetric vapor bubbles when emitted into a fluid. Symmetric vapor bubble generation can maximize the amount of energy per vapor bubble volume transferred to calcium in the coronary artery during the subsequent collapse of the vapor bubbles. In other embodiments, the optical fiber 501 can direct the laser light radiation 512 to a graded index (GRIN) lens 516 configured to direct the laser light radiation 512 through the aperture 513 (shown in FIG. 33 ).

[0060] Referring now to FIG. 35, certain embodiments of the present disclosure may include configurations in which optical fibers are located inside an expandable member (e.g., a balloon catheter). In FIG. 35, schematic cross-sectional views of an IVL catheter 500 taken along section lines AA, BB, and CC are shown. In this embodiment, the IVL catheter 500 includes optical fibers 501-507 housed within an expandable member 520. In the embodiment shown, the expandable member 520 is configured as a catheter balloon that can fold around a central guidewire 510 and an outer coil 511 when the expandable member is in a contracted state. This configuration reduces the overall diameter of the expandable member 520, allowing the expandable member 520 to be more easily positioned at a desired location within an artery or other lumen. The position of the expandable member 520 can be verified via radiopaque markers 521 and 522 before the expandable member 520 is expanded (e.g., inflated via fluid delivered through fluid delivery channels 523 and 524 shown in cross-sectional view AA).

[0061] In certain embodiments, the optical fibers 501-507 can be configured to direct laser light radiation through openings in the outer coil 511 (e.g., through openings via a GRIN lens or optical fiber configuration, as shown in FIGS. 33-34 ), as described in previous embodiments. In specific embodiments, the expandable member 520 can be tapered from approximately 0.55 mm to approximately 0.75 mm, or from approximately 0.65 mm to approximately 0.8 mm. As discussed above, multiple optical fibers 501-507 provide improved spatiotemporal control of laser light radiation. This can allow a user to sequentially time the emission from one fiber to coincide with the collapse of a vapor bubble generated by laser light radiation previously emitted from another fiber (or the same fiber from which the laser source is capable of such emission). Additionally, by distributing the optical fibers circumferentially around the lumen into which the IVL catheter is inserted, a user can orient a particular fiber to provide laser light radiation in a desired direction of emission in order to target a specific location of interest.

[0062] Certain embodiments of the present disclosure may include a tapered fiber coupler configured for use with an IVL catheter. Referring now to FIG. 36 , a partial cross-sectional view of an embodiment of a tapered fiber coupler 600 is shown positioned within the proximal end (e.g., the end proximal to the IVL catheter operator) of a sheath 610 for an optical guidewire. In some embodiments, the sheath 610 may be a steel sheath, and the tapered fiber coupler 600 may include a housing including a glass tubular member 605 having a tapered region 607. In the embodiment shown, light 620 enters the tapered fiber coupler 600 and is directed to optical output fibers 601-603. In the partial cross-sectional view shown in FIG. 36 , three output fibers are shown in an embodiment including a total of seven output fibers. It will be understood that other embodiments may include any number of output fibers within the optical guidewire sheath 610. Each of the optical output fibers 601-603 includes an emitter 613 (eg, a side-firing reflector) configured to redirect the laser light radiation 612 in an outward emitting direction or in other directions, as desired.

[0063] Specific embodiments of the present disclosure may also include one or more lateral coupling fibers, in which an evanescent field in the main fiber couples to one or more emitter fibers. Referring now to FIG. 37 , a main fiber 701, including a core 705 and a cladding 710, is coupled to an emitter fiber 702 via a lateral coupling region 725. The lateral coupling region 725 can be formed via a fused biconical taper (FBT) process or other suitable method. Light 721 propagates through the main fiber 701 via the cladding 710 and through the core 705. A portion of the light 721 propagating through the cladding 710 is directed to the emitter fiber 702 as light 723 via the lateral coupling region 725. The proportion of light 721 transmitted to the emitter fiber 702 as light 723 can be controlled by specifying a desired surface area within the lateral coupling region 725. For example, if more light 723 is desired, a configuration with a larger surface area for the side coupling region 725 can be specified. If less light 723 is desired, a configuration with a smaller surface area for the side coupling region 725 can be specified. The light 723 propagates through the emitter fiber 702 to an emitter 713 (e.g., a side-firing reflector) configured to redirect the laser light radiation 712 into an outward-emitting direction or other direction as desired. While the embodiment shown in FIG. 37 illustrates one side coupling fiber 702, it will be understood that other embodiments may include additional side coupling fibers.

[0064] Certain embodiments of the present disclosure may also include optical fibers with in-line reflectors including dielectric coatings. Referring now to FIG. 38 , multiple optical fibers 801-804 are coupled via a coupling element 805. In the embodiment shown, optical fibers 801-804 include emitters 813 configured as polished ends that are tapered or angled (e.g., 45 degrees in the embodiment shown) and coated with a dielectric reflector. Light 820 propagates through fibers 801-804 and is redirected radially outward through emitters 813 as laser light radiation 812. In some embodiments, coupling element 805 can be configured as a transparent or translucent sleeve that functions as a lens element configured to focus laser light radiation 812.

[0065] All of the devices, systems, and / or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the devices, systems, and methods of the present invention have been described in terms of specific embodiments, it will be apparent to those skilled in the art that modifications can be applied to the devices, systems, and / or methods in the steps or sequence of steps of the methods described herein without departing from the concept, spirit, and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims.

[0066] References: The contents of the following references are incorporated herein by reference: TIFF2026503064000002.tif204161

Claims

1. a diode laser light source; and a polymer optical core; a cladding surrounding the polymer optical core; Laser light emitting element and Optical fiber including 1. An apparatus comprising:

2. 10. The apparatus of claim 1, wherein the laser light emitting element is a first laser light emitting element of a plurality of laser light emitting elements.

3. 3. The apparatus of claim 2, wherein each of the plurality of laser light emitting elements is configured to emit light in a comparable wavelength range.

4. 3. The apparatus of claim 2, wherein each of the plurality of laser light emitting elements is configured to emit light with equal power.

5. a first laser light emitting element of the plurality of laser light emitting elements configured to emit light in a first wavelength range; a second laser light emitting element of the plurality of laser light emitting elements configured to emit light in a second wavelength range; and the first wavelength range is different from the second wavelength range; 3. The device of claim 2.

6. The apparatus of claim 2 , wherein an optical grating within the optical fiber comprises the plurality of laser light emitting elements.

7. 7. The apparatus of claim 2, wherein the plurality of laser light emitting elements emit light radially from the optical fiber.

8. 8. The apparatus of claim 2, wherein the plurality of laser light emitting elements are configured as a row of scattering centers along the polymer optical core of the optical fiber.

9. 8. The device of claim 2, wherein the plurality of laser light emitting elements are configured as scattering centers located at offset locations from the polymer optical core and positioned at equal angles near the cladding.

10. 8. The device of claim 2, wherein the plurality of laser light emitting elements are configured as one or more photonic crystal lattices comprising a plurality of scattering centers in the polymer optical core.

11. 8. The apparatus of claim 7, wherein the plurality of laser light emitting elements comprises N laser light emitting elements, the laser light emitting elements positioned radially around the optical fiber such that there is 360 / N degrees between each laser light emitting element in the plurality of laser light emitting elements.

12. 8. The apparatus of claim 7, wherein the plurality of laser light emitting elements emit light radially 360 degrees around the optical fiber.

13. 13. The apparatus of any one of claims 1 to 12, wherein the diode laser light source is configured to emit laser light at a wavelength of approximately 690 nanometers (nm) to 900 nm.

14. 14. The apparatus of any one of claims 1 to 13, wherein the diode laser light source is capable of providing pulses of light of 50 nanoseconds to 150 microseconds.

15. 15. The apparatus of any one of claims 1 to 14, wherein the radiation power propagating in the optical fiber is between 100 watts (W) and 100 kilowatts (kW).

16. 16. The device of any one of claims 1 to 15, wherein the polymer optical core comprises poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), polyacrylamide (PAM), or a transparent amorphous fluoropolymer.

17. The device of any one of claims 1 to 15, wherein the polymer optical core comprises a transparent thermoplastic material.

18. 18. The device of claim 17, wherein the transparent thermoplastic is poly(methyl methacrylate).

19. The device of any one of claims 1 to 15, wherein the polymer optical core comprises a silicon-based organic polymer.

20. 20. The device of claim 19, wherein the silicon-based organic polymer is polydimethylsiloxane.

21. The device of any one of claims 1 to 15, wherein the polymer optical core comprises a transparent amorphous fluoropolymer.

22. The device of any one of claims 1 to 15, wherein the polymer optical core comprises a synthetic polymer.

23. 20. The device of any one of claims 1 to 19, further comprising an expandable member.

24. 24. The device of claim 23, wherein the expandable member comprises a lumen configured to receive the optical fiber.

25. 25. The device of claim 23 or claim 24, wherein the expandable member contains a fluid.

26. 26. The device of claim 25, wherein the fluid surrounds the optical fiber, the fluid absorbing the light emitted by the diode laser light source.

27. 26. The device of claim 25, wherein the fluid comprises indocyanine green (ICG).

28. 28. The device of claim 27, wherein the fluid comprises a solvent.

29. 29. The device of claim 28, wherein the concentration of the ICG relative to the solvent is between 5 milligrams per milliliter (mg / ml) and 25 mg / ml.

30. 30. The device of claim 28 or 29, wherein the solvent comprises water, saline, or dextrose.

31. 31. The apparatus of any one of claims 1 to 30, further comprising a control system configured to control operating parameters of the diode laser light source.

32. 32. The apparatus of claim 31, wherein the operating parameter is a pulse duration, a wavelength frequency, a number of variable wavelength frequencies, or a wavelength amplitude of the diode laser light source.

33. 32. The apparatus of any one of claims 25 to 31, wherein the control system is configured to provide a first laser light radiation and a second laser light radiation from the diode laser source.

34. 34. The device of claim 33, wherein the first laser light radiation is configured to generate gas bubbles in the fluid in the expandable member.

35. 35. The device of claim 34, wherein the control system is configured to provide the second laser light emission from the diode laser light source upon collapse of the gas bubble in the fluid in the expandable member.

36. 33. The apparatus of any one of claims 1 to 32, wherein the optical fiber comprises an imaging element.

37. 37. The apparatus of claim 36, wherein the imaging element is configured to provide intravascular ultrasound (IVUS) or optical coherence tomography (OCT) imaging data.

38. the diode laser light source is a first diode laser light source among a plurality of diode laser light sources; and the optical fiber is a first optical fiber of a plurality of optical fibers; 37. The device of any one of claims 1 to 36.

39. 39. The apparatus of claim 38, wherein each diode laser source in the plurality of diode laser sources is coupled to a separate optical fiber in the plurality of optical fibers.

40. 40. The apparatus of claim 38, wherein an optical fiber in the plurality of optical fibers comprises a conical distal end.

41. 41. The apparatus of any one of claims 38 to 40, wherein the plurality of optical fibers are coupled via a tapered fiber coupler.

42. 41. The apparatus of any one of claims 38 to 40, wherein the plurality of optical fibers are coupled via a lateral coupling region.

43. 41. The apparatus of any one of claims 38-40, wherein the plurality of optical fibers are coupled via a sleeve coupling element, and at least one of the plurality of optical fibers includes an angled shiny end coated with a dielectric reflector.

44. a diode laser light source; and an optical core; a cladding surrounding the polymer optical core; and an optical fiber; and a plurality of laser light emitting elements, the laser light emitting elements configured as radiating centers at the optical core; 1. An apparatus comprising:

45. 45. The apparatus of claim 44, wherein the plurality of laser light emitting elements are configured as a row of scattering centers along the optical core of the optical fiber.

46. 45. The apparatus of claim 44, wherein the plurality of laser light emitting elements are configured as scattering centers located at offset locations from the optical core and positioned at equal angles near the cladding.

47. 45. The apparatus of claim 44, wherein the plurality of laser light emitting elements are configured as one or more photonic crystal lattices including a plurality of scattering centers in the optical core.

48. 48. The device of any one of claims 44 to 47, wherein the optical core is a polymer optical core.

49. 48. The device of any one of claims 44 to 47, wherein the optical core is a glass optical core.

50. the diode laser light source is a first diode laser light source among a plurality of diode laser light sources; and the optical fiber is a first optical fiber of a plurality of optical fibers; 50. The device of any one of claims 44 to 49.

51. 51. The apparatus of claims 44-50, wherein each diode laser source in said plurality of diode laser sources is coupled to a separate optical fiber in said plurality of optical fibers.

52. 52. The apparatus of claims 44-51, wherein an optical fiber in the plurality of optical fibers comprises a conical distal end.

53. 53. The apparatus of any one of claims 50 to 52, wherein the plurality of optical fibers are coupled via a tapered fiber coupler.

54. 53. The apparatus of any one of claims 50 to 52, wherein the plurality of optical fibers are coupled via a lateral coupling region.

55. 53. The apparatus of any one of claims 50-52, wherein the plurality of optical fibers are coupled via a sleeve coupling element, and at least one of the plurality of optical fibers includes an angled shiny end coated with a dielectric reflector.

56. Methods of breaking down calcium in arteries, including: coupled to a diode laser light source; and a polymer optical core; a cladding surrounding the polymer optical core; Laser light emitting element and Including, inserting an optical fiber into the artery; inserting an expandable member into the artery; expanding the expandable member via fluid in the expandable member; emitting electromagnetic energy from the laser light emitting element to generate pressure waves in the fluid contained within the expandable member; and fracturing the calcium in the artery via the pressure waves in the fluid.

57. 57. The method of claim 56, wherein the laser light emitting element is a first laser light emitting element of a plurality of laser light emitting elements.

58. 58. The method of claim 57, wherein each of the plurality of laser light emitting elements is configured to emit light in a comparable wavelength range.

59. 58. The method of claim 57, wherein each of the plurality of laser light emitting elements is configured to emit light with equal power.

60. a first laser light emitting element of the plurality of laser light emitting elements configured to emit light in a first wavelength range; a second laser light emitting element of the plurality of laser light emitting elements configured to emit light in a second wavelength range; and the first wavelength range is different from the second wavelength range; 58. The method of claim 57.

61. 58. The method of claim 57, wherein the grating structure within the optical fiber includes an element for each laser light emitting element.

62. 62. The method of any one of claims 57 to 61, wherein the plurality of laser light emitting elements emit light radially from the optical fiber.

63. 63. The method of claim 62, wherein the plurality of laser light emitting elements comprises N laser light emitting elements, and the laser light emitting elements are positioned radially around the optical fiber such that there is 360 / N degrees between each laser light emitting element in the plurality of laser light emitting elements.

64. 63. The method of claim 62, wherein the plurality of laser light emitting elements emit light radially 360 degrees around the optical fiber.

65. 65. The method of any one of claims 56-64, wherein the diode laser light source is configured to emit laser light at a wavelength between approximately 690 nanometers (nm) and 900 nm.

66. 66. The method of any one of claims 56 to 65, wherein the diode laser light source is capable of providing pulses of light of 50 nanoseconds to 150 microseconds.

67. 67. The method of any one of claims 56 to 66, wherein the radiation power propagating in the optical fiber is between 100 watts (W) and 100 kilowatts (kW).

68. The method of any one of claims 56 to 67, wherein the polymer optical core comprises a synthetic polymer.

69. 68. The method of any one of claims 56-67, wherein the polymer optical core comprises poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS), polyacrylamide (PAM), or a transparent amorphous fluoropolymer.

70. 68. The method of any one of claims 56 to 67, wherein the polymer optical core comprises a transparent thermoplastic material.

71. 71. The method of claim 70, wherein the transparent thermoplastic is poly(methyl methacrylate).

72. 68. The method of any one of claims 56 to 67, wherein the polymer optical core comprises a silicon-based organic polymer.

73. 73. The method of claim 72, wherein the silicon-based organic polymer is polydimethylsiloxane.

74. 68. The method of any one of claims 56 to 67, wherein the polymer optical core comprises a transparent amorphous fluoropolymer.

75. 75. The method of any one of claims 56-74, wherein the fluid comprises indocyanine green (ICG).

76. 76. The method of claim 75, wherein the fluid comprises a solvent.

77. 77. The method of claim 76, wherein the concentration of the ICG relative to the solvent is 5 milligrams per milliliter (mg / ml) to 25 mg / ml.

78. 78. The method of claim 76 or 77, wherein the solvent comprises water, saline, or dextrose.

79. the expandable member includes a lumen; and the optical fiber extends through the lumen of the expandable member; 79. The method of any one of claims 56 to 78.

80. 80. The method of any one of claims 56 to 79, wherein the optical fiber comprises an imaging element.

81. 81. The method of claim 80, wherein the imaging element is configured to provide intravascular ultrasound (IVUS) or optical coherence tomography (OCT) imaging.

82. inserting the optical fiber into the artery; inserting the expandable member into the artery; expanding the expandable member via fluid in the expandable member; emitting electromagnetic energy from said laser light emitting element; or fracturing said calcium in said artery via said pressure waves in said fluid.

82. The method of claim 80 or 81, wherein the imaging element provides imaging data during

83. 83. The method of any one of claims 80 to 82, wherein the imaging element provides imaging data after the step of fracturing the calcium in the artery via the pressure waves in the fluid.

84. the electromagnetic energy is a first pulse of electromagnetic energy that generates gas bubbles in the fluid in the expandable member; and After the bubbles are generated, the bubbles collapse.

83. The method of any one of claims 56 to 82.

85. 85. The method of claim 84, further comprising emitting a second pulse of electromagnetic energy, the second pulse of electromagnetic energy being emitted after the first pulse of electromagnetic energy.

86. 86. The method of claim 85, wherein the second pulse is emitted about the time the bubble collapses.

87. the diode laser light source is a first diode laser light source among a plurality of diode laser light sources; and the optical fiber is a first optical fiber of a plurality of optical fibers; 87. The method of any one of claims 56 to 86.

88. 88. The method of any one of claims 56 to 87, wherein each diode laser light source in the plurality of diode laser light sources is coupled to a separate optical fiber in the plurality of optical fibers.

89. 89. The method of any one of claims 56-88, wherein the optical fiber in the plurality of optical fibers comprises a conical distal end.

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