Optical needle for spectroscopic diagnosis

• US 5,199,431 A
• Filed: 10/04/1989
• Issued: 04/06/1993
• Est. Priority Date: 03/22/1985
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Feld, Michael S., Kittrell, Carter, Cothren, Robert M. Jr.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US07/417,799
• Time in Patent Office: 1,280 Days
• Field of Search: 128/634, 128/664, 128/665
• US Class Current: 600/477
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 18/245 for removing obstructions in blood vessels or calculi
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/2238 with means for selectively laterally deflecting the tip of the fibre
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: G01N 2021/4747 Concentric bundles
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/14 Mode converters
• CPC Class Codes: G02B 6/241 Light guide terminations
• CPC Class Codes: G02B 6/3504 Rotating, tilting or pivoting the waveguides, or with the waveguides describing a curved path rotary joint G02B6/3628
• CPC Class Codes: G02B 6/3508 Lateral or transverse displacement of the whole waveguides, e.g. by varying the distance between opposed waveguide ends, or by mutual lateral displacement of opposed waveguide ends
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3516 the reflective optical element moving along the beam path, e.g. controllable diffractive effects using multiple micromirrors within the beam
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/3598 Switching means directly located between an optoelectronic element and waveguides, including direct displacement of either the element or the waveguide, e.g. optical pulse generation based on changing the optical properties of the medium G02F1/00; optical pulse generation in optical transmitters H04B10/508; optical pulse generation by controlling laser operation H01S3/00
• CPC Class Codes: G02B 6/4296 coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources

Abstract

A laser catheter is disclosed wherein optical fibers carrying laser light are mounted in a catheter for insertion into an artery to provide controlled delivery of a laser beam for percutaneous intravascular laser treatment of atherosclerotic disease. A transparent protective shield is provided at the distal end of the catheter for mechanically diplacing intravascular blood and protecting the fibers from the intravascular contents, as well as protecting the patient in the event of failure of the fiber optics. Multiple optical fibers allow the selection of tissue that is to be removed. A computer controlled system automatically aligns fibers with the laser and controls exposure time. Spectroscopic diagnostics determine what tissue is to be removed.

Claims

1. An optical needle device for the diagnosis of tissue comprising:

an optical needle having a sharp distal tip for the incision of tissue and an optically conductive element at the distal tip which directs light to a distal surface of the element and through which light is transmitted and received from tissue contacting the distal surface;

a plurality of optical fibers coupled to the optically conductive element to receive light returning from the tissue and directed through the distal surface of the optically conductive element, and to transmit the received light to a proximal end of the optical fibers;

a light source optically coupled to a proximal end of at least one of the optical fibers such that light from the source can be directed through the optically conductive element onto the tissue to be diagnosed; and

an analyzer coupled to the proximal end of at least one of the optical fibers to compare a characteristic of the light emitted by the tissue with a reference signal such that the condition of the tissue can be diagnosed.

2. The optical needle device of claim 1 wherein the optically conductive element comprises a coupling surface coupled to the optical fibers and wherein the distal surface is tapered to the tip.

3. The optical needle device of claim 1 wherein said needle comprises a cannula having a distal opening and a lumen through which the optically conductive element is positioned such that a plane formed by the distal surface lies in a plane formed by the distal opening.

4. The optical needle device of claim 1 wherein said analyzer comprises a spectrometer that spectrally resolves the light emitted by the tissue.

5. The optical needle device of claim 1 further comprising a laser coupled by at least one of the fibers to the optically conductive element.

6. A method of diagnosing tissue comprising:

providing an optical needle having a cutting surface for the incision of tissue and an optical fiber, the optical needle having a distal surface comprising an optically conductive element that delivers light transmitted through the optical fiber to the distal surface at a distal end of the optical needle and adjacent the cutting surface;

inserting the optical needle into a portion of tissue and positioning the distal surface in proximity to a tissue site;

coupling radiation to a proximal end of the fiber such that the radiation is transmitted through the optically conductive element to irradiate tissue to be diagnosed;

receiving light returning from the tissue in response to the irradiation thereof with the optical fiber and delivering the returning light to a proximal end of the optical fiber; and

detecting the returning light delivered at the proximal end and analyzing the detected light at the proximal end to determine the presence of normal or abnormal tissue.

7. The method of claim 6 further comprising coupling laser radiation to the fiber to irradiate the tissue.

8. The method of claim 6 wherein the analyzing step further comprises analyzing fluorescence emitted by the tissue.

9. The method of claim 6 wherein the analyzing step further comprises analyzing a Raman spectrum emitted by the tissue.

10. The method of claim 6 wherein the optically conductive element of the optical needle further comprises an optical shield.

11. The method of claim 6 wherein the analyzing step further comprises directing the emitted light into a spectrometer.

12. A laser cannula device for the diagnosis of tissue comprising:

a cannula having a sharp distal tip for the incision of tissue and an optically conductive element positioned at the distal tip which directs light to a distal surface of the optically conductive element on a distal end of the cannula;

a plurality of optical fibers that are optically coupled to the conductive element;

a laser that is optically coupled to at least one of the plurality of optical fibers such that laser radiation can be delivered through the optically conductive element onto tissue to be diagnosed;

a spectral detector to receive light returning from the tissue through the optically conductive element and at least one of the plurality of optical fibers, the spectral detector separating the received light into separate wavelengths and generating an electrical signal corresponding to an intensity of detected light; and

an electrical circuit for comparing the generated signal with a reference signal to diagnose the tissue.

13. The laser cannula device of claim 12 wherein the optically conductive element comprises an optical shield extending over the distal end of the device, the optical shield having the distal surface.

14. The laser cannula device of claim 12 wherein the optically conductive element comprises a transparent disc.

15. The laser cannula device of claim 12 wherein the cannula comprises a metal tube.

16. The laser cannula device of claim 12 wherein the plurality of optical fibers are fused together at the distal and of the device.

17. A method of diagnosing tissue comprising:

providing a cannula having a cutting surface for the incision of tissue and a plurality of optical fibers extending into the cannula such that light transmitted through at least one of the fibers exits through an optical shield positioned at a distal end of the cannula and adjacent the cutting surface;

inserting the cannula into a portion of tissue and positioning the aperture in proximity to a tissue site to be diagnosed;

coupling laser radiation of a selected wavelength to a proximal end of at least one of the fibers such that the radiation is transmitted through the optical shield to irradiate tissue to be diagnosed;

receiving light returning from the tissue in response to the irradiation thereof with at least one of the fibers and delivering the returning light to the proximal end; and

detecting the returning light with a spectral detector which separates the returning light into different wavelengths and analyzing the detected light at a diagnostic wavelength different from the selected wavelength to determine the presence of normal or abnormal tissue.

18. The method of claim 17 wherein the diagnostic wavelength is a fluorescence emission of the tissue.

19. The method of claim 17 wherein the diagnostic wavelength is a Raman shifted wavelength emitted by the tissue.

20. The method of claim 17 wherein analyzing further comprises comparing a detected spectrum with a reference spectrum.