US5034010A — Optical shield for a laser catheter

Claim 1

Independent Claim 234 words

A method for treatment of lesions or obstructions in tissue of a body vessel or cavity comprising the steps of: providing a plurality of optical fibers in which the distal end of the catheter is enclosed by an optical shield transparent to optical light radiation and wherein the proximal end of the catheter and optical fibers may be coupled to a laser or other light source; inserting said catheter into said body vessel or cavity until the optical shield is brought into contact with a suspected lesion or obstruction; selecting an optical fiber such that radiation will fall on tissue or an obstruction to be treated; coupling laser radiation of appropriate power and energy into the proximal end of said selected fiber such that radiation is transmitted through said fiber to a region on the distal surface of the shield to irradiate with a predetermined dose and thereby remove at least a portion of the selected amount of tissue or obstruction; repeating the selecting and coupling steps with other optical fibers that direct radiation onto additional regions of the shield until a desired amount of tissue or obstruction adjacent to the optical shield has been removed; repositioning the catheter and optical shield so as to bring it in contact with additional tissue or obstruction to be removed, and repeating the above steps as needed until all the desired tissue or obstruction has been removed.

Claim 2

Independent Claim 234 words

A method for treatment of lesions or obstructions in tissue of a body vessel or cavity comprising the steps of: providing a plurality of optical fibers in which the distal end of the catheter is enclosed by an optical shield transparent to optical light radiation and wherein the proximal end of the catheter and optical fibers may be coupled to a laser or other light source; inserting said catheter into said body vessel or cavity until the optical shield is brought into contact with a suspected lesion or obstruction; selecting an optical fiber such that radiation will fall on tissue or an obstruction to be treated; coupling laser radiation of appropriate power and energy into the proximal end of said selected fiber such that radiation is transmitted through said fiber to a region on the distal surface of the shield to irradiate with a predetermined dose and thereby remove at least a portion of the selected amount of tissue or obstruction; repeating the selecting and coupling steps with other optical fibers that direct radiation onto additional regions of the shield until a desired amount of tissue or obstruction adjacent to the optical shield has been removed; repositioning the catheter and optical shield so as to bring it in contact with additional tissue or obstruction to be removed, and repeating the above steps as needed until all the desired tissue or obstruction has been removed.

Claim 3

Dependent Claim 141 words

The method of treatment of claim 1 wherein the selecting step further comprises coupling low power light from a light source to the proximal end of said optical fiber whereby the light enters the proximal end of the laser fiber and the light is transmitted to the distal end of said fiber through the optical shield to impinge on the lesion such that light emitted by the tissue is returned to the proximal end of the selected optical fiber and is coupled to a spectral analyzer wherein it is determined if the material contacted by or adjacent to the optical shield and, in particular, the portion irradiated by the incident light from the selected optical fiber, is healthy material or other material; and, in the event that the material is to be treated proceeding with the step of coupling laser radiation.

Claim 4

Dependent Claim 14 words

The method of claim 1 wherein the laser catheter is inserted into an artery.

Claim 5

Dependent Claim 26 words

The method of claim 3 wherein the light source is one or any combination of the ultraviolet wavelengths of an argon ion or krypton ion laser.

Claim 6

Dependent Claim 13 words

The method of claim 3 wherein the light source is a laser device.

Claim 7

Dependent Claim 35 words

The method of claim 3 wherein the light is pulsed laser radiation taken from the class comprising nitrogen lasers, excimer lasers, harmonics of Nd:YAG lasers, or a copper vapor laser, or a pulsed dye laser.

Claim 8

Dependent Claim 61 words

The method of claim 3 wherein the appropriate spectral or temporal analysis is stored in computer memory for any fiber, forming a "map" of tissue types adjacent to the catheter; and when ao appropriate fiber is selected, laser radiation is coupled into the proximal end of said fiber, thereby treating or removing corresponding tissue at the distal end of said fiber.

Claim 9

Dependent Claim 17 words

The method of claim 1 the laser catheter is used for ablating or tunnelling into any tissue.

Claim 10

Dependent Claim 29 words

The method of claim 1 wherein the proximal ends of the optical fibers are aligned in a linear array which may be translated past the source of laser radiation.

Claim 11

Dependent Claim 35 words

The method of claim 1 in which the proximal ends of the optical fibers are aligned in a circular array and the source of laser radiation may be directed onto them by a rotating mirror.

Claim 12

Dependent Claim 39 words

The method of claim 1 wherein the proximal ends of the optical fibers are held in an array and the source of laser radiation is directed onto them using one or more mirrors and one or more translational devices.

Claim 13

Dependent Claim 31 words

The method of claim 1 wherein the source of laser radiation is directed onto the proximal ends of the optical fibers by galvo scanners or an acousto-optic or electro-optic beam deflector.

Claim 14

Dependent Claim 34 words

The method of claim 1 wherein correct alignment of the laser radiation coupling into the selected optical fiber is monitored by detecting scattered light from the proximal end with a photodiode or similar photodetector.

Claim 15

Dependent Claim 16 words

The method of claim 13 wherein an automatic control connected to said photodetector maintains optimal alignment.

Claim 16

Dependent Claim 37 words

The method of claim 1 wherein light returning in the same or adjacent fibers is monitored for sudden increases in return light indicative of fiber failure, and laser radiation is terminated when such a failure is detected.

Claim 17

Dependent Claim 17 words

The method of claim 1 wherein the power of the laser radiation is regulated by an attenuator.

Claim 18

Dependent Claim 19 words

The method of claim 16 wherein the attenuator is a rotating half wave plate in combination with a polarizer.

Claim 19

Dependent Claim 16 words

The method of claim 16 wherein the attenuator comprises an array of tilting Fresnel reflection plates.

Claim 20

Dependent Claim 18 words

The method of claim 1 wherein the exposure time of the laser catheter is regulated by a shutter.

Claim 21

Dependent Claim 21 words

The method of treatment of claim 1 wherein tissue is removed asymetrically or primarily on one side of the optical shield.

Claim 22

Dependent Claim 20 words

The method of claim 20 wherein the optical shield is advanced in an approximately helical path as tissue is removed.

Claim 23

Dependent Claim 39 words

The method of claim 21 wherein the catheter is provided with a guide wire and the radius of the lumen being formed as the shield is advanced is determined by the spacing between guide wire and the optical shield.

Claim 24

Independent Claim 312 words

A method for treatment of arterial tissue of obstructions comprising the steps of: a) providing a catheter with a plurality of optical fibers in which the distal end of the catheter is enclosed by an optical shield transparent to light radiation and wherein the proximal end of the catheter and optical fibers may be coupled to light sources of optical radiation of relatively high or lower power wherein the high power radiation is capable of removing tissue and the lower power radiation is capable of exciting but not of removing tissue; b) inserting said catheter into an artery until the optical shield is brought into contact with the suspected arterial lesion; c) selecting an optical fiber and coupling the low power optical radiation from the light source to the proximal end of said optical fiber whereby the light enters the proximal end of the optical fiber and is transmitted by the selected optical fiber to the distal end of said fiber out the optical shield and impinges on the suspected lesion, and light emitted by the tissue is returned to the proximal end of the selected optical fiber, and is coupled to a spectral analyzer wherein the light excited by said light is analyzed to determine if the material contacted by the optical shield and, irradiated by the incident light from the selected optical fiber is healthy arterial tissue or plaque or other material; d) in the event it is determined that the material is to be removed, coupling the proximal end of said selected optical fiber to the source of relatively high power radiation and coupling said radiation to the proximal end of said selected optical fiber whereby such radiation is transmitted through said fiber to the distal end to irradiate a portion of the tissue; e) repeating the above steps until the shield is in contact only with healthy tissue.

Claim 25

Independent Claim 312 words

A method for treatment of arterial tissue of obstructions comprising the steps of: a) providing a catheter with a plurality of optical fibers in which the distal end of the catheter is enclosed by an optical shield transparent to light radiation and wherein the proximal end of the catheter and optical fibers may be coupled to light sources of optical radiation of relatively high or lower power wherein the high power radiation is capable of removing tissue and the lower power radiation is capable of exciting but not of removing tissue; b) inserting said catheter into an artery until the optical shield is brought into contact with the suspected arterial lesion; c) selecting an optical fiber and coupling the low power optical radiation from the light source to the proximal end of said optical fiber whereby the light enters the proximal end of the optical fiber and is transmitted by the selected optical fiber to the distal end of said fiber out the optical shield and impinges on the suspected lesion, and light emitted by the tissue is returned to the proximal end of the selected optical fiber, and is coupled to a spectral analyzer wherein the light excited by said light is analyzed to determine if the material contacted by the optical shield and, irradiated by the incident light from the selected optical fiber is healthy arterial tissue or plaque or other material; d) in the event it is determined that the material is to be removed, coupling the proximal end of said selected optical fiber to the source of relatively high power radiation and coupling said radiation to the proximal end of said selected optical fiber whereby such radiation is transmitted through said fiber to the distal end to irradiate a portion of the tissue; e) repeating the above steps until the shield is in contact only with healthy tissue.

Claim 26

Dependent Claim 41 words

The method of claim 23 wherein determination of the nature of the tissue being removed is based on fluorescence or scattered light returning from the tissue irradiated by the high power radiation, instead of the second lower power source of radiation.

Claim 27

Independent Claim 229 words

A method for tunneling into and/or treatment of lesions or bodily tissue comprising the steps of: a) providing a laser cannula with a plurality of optical fibers in which the distal end of the cannula is enclosed by an optical shield transparent to optical light radiation and wherein the proximal end of the cannula and optical fibers may be coupled to a laser or other light source of relatively high or low power; b) inserting said cannula into or against said body tissue until the optical shield is brought into contact with a suspected lesion or tissue to be removed; c) selecting an optical fiber such that radiation will fall on tissue or lesion to be treated; and coupling laser radiation of appropriate power and energy into the proximal end of said selected fiber whereby such radiation is transmitted through said fiber to the distal end to irradiate and thereby remove the selected tissue or lesion; d) repeating the above steps with other optical fibers until all tissue or lesion adjacent to the optical shield has been treated and/or removed as needed; e) repositioning the catheter and optical shield forward or laterally so as to bring it in contact with or adjacent to additional tissue or lesion to be treated, and repeating the above steps as needed until all the desired tissue or obstruction has been treated or removed.

Claim 28

Independent Claim 229 words

A method for tunneling into and/or treatment of lesions or bodily tissue comprising the steps of: a) providing a laser cannula with a plurality of optical fibers in which the distal end of the cannula is enclosed by an optical shield transparent to optical light radiation and wherein the proximal end of the cannula and optical fibers may be coupled to a laser or other light source of relatively high or low power; b) inserting said cannula into or against said body tissue until the optical shield is brought into contact with a suspected lesion or tissue to be removed; c) selecting an optical fiber such that radiation will fall on tissue or lesion to be treated; and coupling laser radiation of appropriate power and energy into the proximal end of said selected fiber whereby such radiation is transmitted through said fiber to the distal end to irradiate and thereby remove the selected tissue or lesion; d) repeating the above steps with other optical fibers until all tissue or lesion adjacent to the optical shield has been treated and/or removed as needed; e) repositioning the catheter and optical shield forward or laterally so as to bring it in contact with or adjacent to additional tissue or lesion to be treated, and repeating the above steps as needed until all the desired tissue or obstruction has been treated or removed.

Claim 29

Dependent Claim 140 words

The method of treatment of claim 25 wherein selecting an optical fiber and coupling low power light from a light source to the proximal end of said optical fiber whereby the light enters the proximal end of the laser fiber and the light is transmitted to the distal end of said fiber out the optical shield to impinge on the lesion and the scattered and fluorescent light is returned to the proximal end of the selected optical fiber and is coupled to a spectral analyzer wherein it is determined if the material contacted by or adjacent to the optical shield and, in particular, the portion irradiated by the incident light from the selected optical fiber, is healthy material or other material; and, in the event that the material is to be treated or proceeding with step (c) of claim 25.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-07-22	1995-01-21	1995-07-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-07-22	1999-01-21	1999-07-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-07-22	2003-01-21	2003-07-23	$7700.00	Window Closed / Lapsed

Optical shield for a laser catheter

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag