Photoacoustic removal of occlusions from blood vessels
First Claim
1. A method of opening to the flow of blood a human blood vessel that is at least partially blocked by an occlusion, comprising:
- providing optical fibers, each of the optical fibers having a core diameter of less than or equal to 200 microns and having an optical fiber end;
positioning within the vessel an array of the optical fiber ends; and
directing a sequence of one or more pulses of radiation out of one or more of the optical fiber ends and subsequently directing a sequence of pulses of radiation out of one or more of the other of the optical fiber ends, the pulses individually having a duration of less than or equal to 100 nanoseconds and containing sufficient energy to generate at least one shock wave and at least one bubble in a volume immediately adjacent the optical fiber ends which together cause a portion of the occlusion to be disrupted.
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Accused Products
Abstract
Partial or total occlusions of fluid passages within the human body are removed by positioning an array of optical fibers in the passage and directing treatment radiation pulses along the fibers, one at a time, to generate a shock wave and hydrodynamics flows that strike and emulsify the occlusions. A preferred application is the removal of blood clots (thrombin and embolic) from small cerebral vessels to reverse the effects of an ischemic stroke. The operating parameters and techniques are chosen to minimize the amount of heating of the fragile cerebral vessel walls occurring during this photo acoustic treatment. One such technique is the optical monitoring of the existence of hydrodynamics flow generating vapor bubbles when they are expected to occur and stopping the heat generating pulses propagated along an optical fiber that is not generating such bubbles.
116 Citations
20 Claims
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1. A method of opening to the flow of blood a human blood vessel that is at least partially blocked by an occlusion, comprising:
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providing optical fibers, each of the optical fibers having a core diameter of less than or equal to 200 microns and having an optical fiber end;
positioning within the vessel an array of the optical fiber ends; and
directing a sequence of one or more pulses of radiation out of one or more of the optical fiber ends and subsequently directing a sequence of pulses of radiation out of one or more of the other of the optical fiber ends, the pulses individually having a duration of less than or equal to 100 nanoseconds and containing sufficient energy to generate at least one shock wave and at least one bubble in a volume immediately adjacent the optical fiber ends which together cause a portion of the occlusion to be disrupted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of opening to the flow of blood a human blood vessel that is at least partially blocked by an occlusion, comprising:
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providing optical fibers, each of the optical fibers having a core diameter of less than or equal to 200 microns and having an optical fiber end;
positioning within the vessel an array of the optical fiber ends; and
directing a sequence of one or more pulses out of one or more of the optical fiber ends and subsequently directing a sequence of pulses of radiation out of one or more of the other of the optical fiber ends, the pulses individually having a duration of less than or equal to 100 nanoseconds and containing energy of less than 250 microJoules, the energy being sufficient to generate at least one shock wave and at least one bubble in a volume immediately adjacent the optical fiber ends which together cause a portion of the occlusion to be disrupted.
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Specification