Opto-acoustic thrombolysis
First Claim
1. A method for delivering acoustic energy into the cerebrovasculature during percutaneous transluminal access procedures, comprising:
- inserting a fiber optic into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; and
coupling laser light into said proximal end, wherein said laser light has (i) a pulse frequency within the range of 5 kHz to 25 kHz, (ii) a wavelength within the range of 200 nm to 5000 nm and (iii) an energy density within the range of 0.01 J/cm2 to 4 J/cm2, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium, wherein said acoustic radiation field is generated through one or more mechanisms selected from a group consisting of thermoelastic expansion within said liquid ambient medium and superheated vapor expansion within said liquid ambient medium.
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Accused Products
Abstract
This invention is a catheter-based device for generating an ultrasound excitation in biological tissue. Pulsed laser light is guided through an optical fiber to provide the energy for producing the acoustic vibrations. The optical energy is deposited in a water-based absorbing fluid, e.g. saline, thrombolytic agent, blood or thrombus, and generates an acoustic impulse in the fluid through thermoelastic and/or thermodynamic mechanisms. By pulsing the laser at a repetition rate (which may vary from 10 Hz to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus or treating vasospasm. The catheter can also incorporate thrombolytic drug treatments as an adjunct therapy and it can be operated in conjunction with ultrasonic detection equipment for imaging and feedback control and with optical sensors for characterization of thrombus type and consistency.
365 Citations
117 Claims
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1. A method for delivering acoustic energy into the cerebrovasculature during percutaneous transluminal access procedures, comprising:
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inserting a fiber optic into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; and coupling laser light into said proximal end, wherein said laser light has (i) a pulse frequency within the range of 5 kHz to 25 kHz, (ii) a wavelength within the range of 200 nm to 5000 nm and (iii) an energy density within the range of 0.01 J/cm2 to 4 J/cm2, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium, wherein said acoustic radiation field is generated through one or more mechanisms selected from a group consisting of thermoelastic expansion within said liquid ambient medium and superheated vapor expansion within said liquid ambient medium.
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2. A method, comprising:
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inserting a fiber optic into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; and coupling laser light into said proximal end, wherein said laser light has (i) a pulse frequency within the range of 10 Hz to 100 kHz, (ii) a wavelength within the range of 200 nm to 5000 nm and (iii) an energy density within the range of 0.01 J/cm2 to 4 J/cm2, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method, comprising:
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inserting a fiber optic into the vasculature to a point near an occlusion, wherein said fiber optic is located within a catheter, wherein said fiber optic comprises a proximal end and a distal end; coupling laser light into said proximal end, wherein said laser light has (i) a pulse frequency within the range of from about 1 kHz to 25 kHz and (ii) a wavelength within the range of 200 nm to 5000 nm, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium; and injecting through said catheter into said liquid ambient medium a radiographic contrast agent to facilitate visualization. - View Dependent Claims (25, 59)
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22. A method, comprising:
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inserting a fiber optic into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; coupling laser light into said proximal end, wherein said laser light has (i) a pulse frequency within the range of from about 1 kHz to 25 kHz and (ii) a wavelength within the range of 200 nm to 5000 nm, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium; and monitoring and controlling the magnitude of the acoustic radiation field induced in the liquid ambient medium through a feedback mechanism.
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23. A method, comprising:
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inserting a bundle of fiber optic strands into the vasculature to a point near an occlusion, wherein each of said fiber optic strands comprises a proximal end and a distal end; and coupling laser light into each of said proximal ends, wherein said laser light has (i) a pulse frequency within the range of from about 1 kHz to 25 kHz and (ii) a wavelength within the range of 200 nm to 5000 nm, wherein said laser light emerges from said distal end to generate an acoustic radiation field in a liquid ambient medium; said laser light being coupled into said proximal ends at varying times, said laser light within individual strands of said bundle arriving at said distal ends at different times, wherein said different times are adjusted to control the directionality and shape of said acoustic radiation field, and wherein said different times are adjusted in combination with the different spatial positions of said individual strands.
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24. A method for producing an acoustic radiation field through thermoelastic expansion of a liquid ambient medium located within vasculature, comprising:
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inserting a fiber optic into said vasculature; depositing laser energy in a volume of said liquid ambient medium comparable to the diameter of said fiber optic, in a time scale of duration less than the acoustic transit time across the length of said volume; controlling said laser energy such that the maximum size of a cavitation bubble is approximately the same as the fiber diameter; and pulsing said laser energy at a repetition rate such that multiple cycles of this process generates said acoustic radiation field in said liquid ambient medium.
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26. A method for producing an acoustic radiation field through vapor expansion of a liquid ambient medium located within vasculature, comprising:
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inserting a fiber optic into said vasculature; depositing laser energy in a small volume of said liquid ambient medium to produce a vapor bubble; controlling said laser energy such that the maximum size of said vapor bubble is approximately the same as or less than the diameter of said vasculature; and pulsing said laser energy at a repetition rate such that multiple cycles of the generation and collapse of said vapor bubble generates said acoustic radiation field in said liquid ambient medium. - View Dependent Claims (27)
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28. An apparatus, comprising:
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a fiber optic for insertion into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; and a laser to provide laser light for coupling into said proximal end, wherein said laser light has (i) a pulse frequency within the range of 10 Hz and 100 kHz, (ii) a wavelength within the range of 200 nm and 5000 nm and (iii) an energy density within the range of 0.01 J/cm2 to 4 J/cm2, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62)
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63. An apparatus, comprising:
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a fiber optic for insertion into the vasculature to a point near an occlusion, wherein said fiber optic comprises a proximal end and a distal end; a laser to provide laser light for coupling into said proximal end, wherein said laser light has (i) a pulse frequency within the range of 10 Hz and 100 kHz and (ii) a wavelength within the range of 200 nm and 5000 nm, wherein said laser light emerges from said distal end and generates an acoustic radiation field in a liquid ambient medium; and a catheter and means for injecting a radiographic contrast agent into the vasculature, wherein said fiber optic is located within said catheter, wherein said radiographic contrast agent may be injected through said catheter into said liquid ambient medium to facilitate visualization.
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64. An apparatus for producing an acoustic radiation field through thermoelastic expansion of a liquid ambient medium located within vasculature, comprising:
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a fiber optic for insertion into said vasculature; means for depositing laser energy in a volume of said liquid ambient medium, wherein said volume is comparable to the diameter of said fiber optic, wherein said laser energy is deposited in a time scale of duration less than the acoustic transit time across the length of said volume; means for controlling said laser energy such that the maximum size of a cavitation bubble is approximately the same as the diameter of said fiber optic; and means for pulsing said laser energy at a repetition rate such that multiple cycles of this process generates said acoustic radiation field in said liquid ambient medium. - View Dependent Claims (65)
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66. An apparatus for producing an acoustic radiation field through vapor expansion of a liquid ambient medium located within vasculature, comprising:
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a fiber optic for insertion into said vasculature; means for depositing laser energy in a small volume of said liquid ambient medium to produce a vapor bubble; means for controlling said laser energy such that the maximum size of said vapor bubble is approximately the same as or less than the diameter of said vasculature; and means for pulsing said laser energy at a repetition rate such that multiple cycles of the generation and collapse of said vapor bubble generates said acoustic radiation field in said liquid ambient medium.
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67. A method of removing an occlusion in a blood vessel, comprising:
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inserting a catheter into the vessel with an end adjacent the occlusion, the catheter including a plurality of optical fibers individually having a diameter of less than 400 microns and with ends thereof spatially distributed across the catheter end, and directing pulses of radiation within a wavelength range of from 200 to 5000 nanometers at a rate of more than 1 kiloHertz along individual ones of the fibers to exit their ends at different times and in a manner to generate acoustic vibrations within the vessel that emulsify the occlusion. - View Dependent Claims (68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84)
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85. A method of removing a clot from a blood vessel within a human cranial cavity above the carotid artery, comprising:
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inserting a catheter into the vessel with an end adjacent the clot, the catheter including a plurality of optical fibers individually having a diameter of less than 400 microns and with ends thereof spatially distributed across the catheter end, introducing a stream through a lumen of the catheter that is directed toward the clot, and directing pulses of radiation within a wavelength range of from 200 to 5000 nanometers along individual ones of the fibers at different times with a rate of more than 1 kiloHertz, said radiation pulses exiting the fiber ends to be absorbed within a region of liquid in the vessel or the clot in a manner to generate acoustic vibrations therein that emulsify the clot, wherein the duration of individual ones of said radiation pulses is less than an acoustic transit time across a smallest dimension of said absorption region. - View Dependent Claims (86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96)
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97. A system for opening an occlusion within a blood vessel by generating acoustical vibrations within the vessel, comprising:
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a flexible catheter adapted to be inserted into said vessel and including a plurality of optical fibers individually having a diameter of less than 400 microns and with first ends thereof spatially distributed across a free end of the catheter, a source of radiation pulses within a wavelength range of from 200 to 5000 nanometers optically coupled with second ends of said optical fibers in a manner to provide said radiation pulses along individual ones of the fibers to exit their first ends at different times with a repetition rate of more than 1 kiloHertz, a fluid channel terminating at the free end of the catheter for carrying liquid into the vessel during application of radiation pulses, and a feedback mechanism that monitors and controls acoustic vibrations generated within the vessel by the radiation pulses. - View Dependent Claims (98, 99, 100)
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101. An apparatus for opening an occlusion within a fluid-containing body vessel by generating acoustical vibrations within the vessel, comprising:
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a flexible catheter adapted to be inserted into said vessel and including a plurality of optical fibers individually having a diameter of less than 400 microns and with first ends thereof spatially distributed across a free end of the catheter, and a source of radiation pulses within a wavelength range of from 200 to 5000 nanometers optically coupled with second ends of said optical fibers in a manner to provide said radiation pulses along individual ones of the fibers to exit their first ends at different times with a repetition rate of more than 1 kiloHertz, such that said pulses of radiation are absorbed by the vessel fluid or the occlusion in a manner to generate said acoustical vibrations that emulsify said occlusion. - View Dependent Claims (102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116)
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117. An apparatus for opening a clot within a blood vessel in a human cranial cavity by generating acoustical vibrations within the vessel, comprising:
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a flexible catheter adapted to be inserted into said vessel and including a plurality of optical fibers individually having a diameter of less than 400 microns and with first ends thereof spatially distributed across a free end of the catheter, and a source of radiation pulses within a wavelength range of from 200 to 5000 nanometers optically coupled with second ends of said optical fibers in a manner to provide said radiation pulses along individual ones of the fibers to exit their first ends at different times with a repetition rate of more than 1 kiloHertz, wherein the duration of individual ones of said radiation pulses is less than an acoustic transit time across a smallest dimension of a region within the vessel in which the radiation is absorbed, such that said pulses of radiation generate said acoustical vibrations which emulsify at least a portion of said occlusion without directly abating said occlusion.
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Specification