Catheter system for controlled removal by radiant energy of biological obstructions
First Claim
1. A method for recanalizing an obstructed lumen by removing successive layers of biological obstructing material so as to form a hole through said material by application of radiant energy comprising:
- providing a catheter having waveguide means, the catheter having a distally located emission aperture for emission of said radiant energy in a beam propagating along a beam axis, said emission aperture having cross-sectional dimensions corresponding substantially to cross-sectional dimension of the catheter;
inserting said catheter into said lumen to locate the emission aperture in proximity to the obstruction;
directing said radiant energy through the waveguide means to cause emission of said beam from said emission aperture;
controlling said emitted beam to define an unfocused working region extending distally from said emission aperture and around said axis in which the density of said energy is sufficient to cause said removal and so that portion of the beam which propagates distally beyond the working region will have insufficient energy density to cause said removal;
said working region defining a cross-section substantially large enough to enable the catheter to be passed through a hole formed by the working region, the working region having an axially depth not substantially greater than about cross-sectional dimension of the catheter;
applying the working region of the beam to the obstructing material thereby to form a hole by removal of said material to a depth no greater than about the axial extent of said working region; and
advancing said catheter through said hole.
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Accused Products
Abstract
A catheter for delivering radiant energy, such as a laser beam, is used in a technique to controllably apply the radiant energy in a patient'"'"'s body, such as in a blood vessel. The radiant energy is applied in a manner which erodes biological material and may be used to drill through vascular obstructions. The catheter emits the radiant energy from its distal end in a pattern which defines a relatively small working region in which the energy density level is sufficiently high to remove the biological material. The energy distribution is substantially uniform across the beam. Distally beyond the working region, the energy density of the beam decays sharply so that biological material beyond the working region is not removed.
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Citations
50 Claims
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1. A method for recanalizing an obstructed lumen by removing successive layers of biological obstructing material so as to form a hole through said material by application of radiant energy comprising:
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providing a catheter having waveguide means, the catheter having a distally located emission aperture for emission of said radiant energy in a beam propagating along a beam axis, said emission aperture having cross-sectional dimensions corresponding substantially to cross-sectional dimension of the catheter; inserting said catheter into said lumen to locate the emission aperture in proximity to the obstruction; directing said radiant energy through the waveguide means to cause emission of said beam from said emission aperture; controlling said emitted beam to define an unfocused working region extending distally from said emission aperture and around said axis in which the density of said energy is sufficient to cause said removal and so that portion of the beam which propagates distally beyond the working region will have insufficient energy density to cause said removal; said working region defining a cross-section substantially large enough to enable the catheter to be passed through a hole formed by the working region, the working region having an axially depth not substantially greater than about cross-sectional dimension of the catheter; applying the working region of the beam to the obstructing material thereby to form a hole by removal of said material to a depth no greater than about the axial extent of said working region; and advancing said catheter through said hole. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of removing a biological obstruction by radiant energy comprising:
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providing a catheter having waveguide means for guiding said radiant energy from a source thereof, said catheter having a distally located emission aperture for emission of said radiant energy in a beam propagating along beam axis; forming said beam into a geometrically expanding pattern in which the energy distribution around said beam axis is substantially uniform whereby the energy density of said beam along said beam axis when applied to said obstruction decreases both exponentially and geometrically in a distally extending direction; the energy density in a working region of the beam within a first isothermal zone being sufficient to effect removal of the material forming the obstruction when said material is located in said region, the portion of the beam extending distally of said working region having insufficient energy density to effect said removal; said working region defining cross sectional dimensions large enough to enable the catheter to be passed therethrough, the working region having an axially extending depth not substantially greater than about the cross-sectional dimension of the catheter; whereby when said beam of energy is applied to the biological material said radiant energy will be effective to remove said material to a depth no greater than about the axial depth of said working region, thereby limiting said removal to a layer approximating the axial depth of said working region, and minimizing perforation of tissue located distal or radial to the isothermal boundary of said working region. - View Dependent Claims (18, 19, 20)
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21. A catheter for recanalizing an obstructed lumen by selectively removing sequential layers of biological obstructing material by radiant energy comprising:
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an elongate catheter body containing a flexible optical conductor; the proximal end of the catheter having means to enable said radiant energy to enter the flexible optical conductor; the distal end of the catheter having an emission aperture from which a beam of said radiant energy may be emitted, said emission aperture having a cross-sectional dimension which substantially corresponds to that of the distal end of the catheter; said catheter and emission aperture being constructed and arranged to shape the radiant energy beam emitted from the emission aperture to define an unfocused beam having a working region in which the density of energy is sufficient to cause said removal, and so that the portion of the beam extending distal to the working region has insufficient energy density to cause said removal; and the cross-sectional dimensions of the beam in the working region being no smaller than about the diameter of the distal end of the catheter thereby to enable the catheter to be passed through a recanalized hole formed by said working region, the axial depth of the working region being not substantially greater than the cross-sectional dimension of the distal end of the catheter. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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49. A method of removing a biological obstruction by radiant energy comprising:
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providing a catheter having waveguide means for guiding said radiant energy from a source thereof, said catheter having a distally located emission aperture for emission of said radiant energy in a pattern propagating along an axis; forming said emitted radiant energy into a geometrically expanding pattern in which the energy distribution around said axis is substantially uniform whereby the energy density of said emitted energy along said axis when applied to said obstruction decreases both exponentially and geometrically in a distally extending direction; the energy density in a working region of the emitted energy within a first isothermal zone being sufficient to effect removal of the material forming the obstruction when said material is located in said region, the portion of the emitted energy extending distally of said working region having insufficient energy density to effect said removal; said working region defining cross-section dimensions large enough to enable the catheter to be passed therethrough, the working region having an axially extending depth not substantially greater than about the cross-sectional dimension of the catheter; whereby when said emitted energy is applied to the biological material said radiant energy will be effective to remove said material to a depth no greater than about the axial depth of said working region, thereby limiting said removal to a layer approximating the axial depth of said working region, and minimizing perforation of tissue located distal or radial to the isothermal boundary of said working region.
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50. A catheter for recanalizing an obstructed lumen by selectively removing sequential layers of biological obstructing material by radiant energy comprising:
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an elongate catheter body containing a flexible optical conductor; the proximal end of the catheter having means to enable said radiant energy to enter the flexible optical conductor; the distal end of the catheter having an emission aperture from which said radiant energy may be emitted, said emission aperture having a cross-sectional dimension which substantially corresponds to that of the distal end of the catheter; said catheter and emission aperture being constructed and arranged to shape the radiant energy emitted from the emission aperture to define an unfocused pattern having a working region in which the density of energy is sufficient to cause said removal, and so that the portion of the emitted energy extending distal to the working region has insufficient energy density to cause said removal; and the cross-sectional dimensions of the emitted energy in the working region being no smaller than about the diameter of the distal end of the catheter thereby to enable the catheter to be passed through a recanalized hole formed by said working region, the axial depth of the working region being not substantially greater than the cross-sectional dimension of the distal end of the catheter.
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Specification