Imaging elastic scattering spectroscopy

• US 7,428,048 B1
• Filed: 12/30/2004
• Issued: 09/23/2008
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Spectral Molecular Imaging, Inc. (Cascade Technologies Corp.)
• Original Assignee: Spectral Molecular Imaging, Inc. (Cascade Technologies Corp.)
• Inventors: Wachman, Jill, Farkas, Daniel L., Wachman, Elliot S., Farkas, Miriam, Lindsley, Erik H.
• Primary Examiner(s): Connolly; Patrick J
• Assistant Examiner(s): Skovholt; Jonathan
• Application Number:
  US11/026,912
• Time in Patent Office: 1,363 Days
• Field of Search: 356/364
• US Class Current: 356/364
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• 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 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0278 Control or determination of height or angle information for sensors or receivers
• CPC Class Codes: G01J 3/447 Polarisation spectrometry
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

An apparatus for image elastic scattering spectroscopy is disclosed that is comprised of a light source for generating polarized light. Means are provided to convey the polarized light to a target. A collector receives light reflected from the target. A detector is responsive to the collector for generating images at both parallel and perpendicular polarizations for each of a plurality of wavelengths. A range finder detects a distance to the target. Control electronics control the image generation and the range finder. The apparatus may be configured to image areas on the surface of the body or configured so as to be inserted into various body cavities. Typically, the apparatus will be used in conjunction with an analyzer for analyzing the images for evidence of abnormal cells. Methods of gathering data and of screening for abnormal cells are also disclosed.

Claims

1. An apparatus, comprising:

a light source for generating polarized light;

a first fiber optic path having a proximal end optically coupled to said light source and a distal end having an illumination port for illuminating a target;

a second fiber optic path having a proximal end and a distal end having an imaging port for receiving light emitted from the target in response to the illumination by the illumination port, said first and second fiber optic paths constructed such that said distal ends can be inserted into a body cavity;

a detector optically coupled to said proximal end of said second fiber optic path for generating images at both parallel and perpendicular polarizations for each of a plurality of wavelengths;

a range finder for detecting a distance from said distal ends of said fiber optic paths to the target;

control electronics for controlling the generating of images and the range finder; and

an analyzer programmed to determine information about the size of scattering elements at different spatial locations of the target based on the generated images and the detected distance.

2. The apparatus of claim 1 wherein either said light source or said detector is wavelength tunable.

3. The apparatus of claim 1 wherein said detector includes a charge coupled device.

4. The apparatus of claim 1 wherein said light source includes a monochromator.

5. The apparatus of claim 1 wherein said light source includes an acousto-optic tunable filter.

6. The apparatus of claim 1 wherein said detector includes an acousto-optic tunable filter.

7. The apparatus of claim 1 wherein said light source includes a polarizing element in series with a source of illumination.

8. The apparatus of claim 1 wherein said range finder includes either an optical, acoustical or mechanical device.

9. The apparatus of claim 1 wherein said range finder comprises:

a light source for generating a collimated beam of known diameter and degree of collimation for illuminating a spot of said target; and

a collector for detecting and recording the size of the illuminated spot reflected from said target;

wherein said control electronics calculates the distance from said distal ends of said fiber optic paths to said target using the size of the illuminated spot and the known diameter and degree of collimation of the beam.

10. A method comprising:

using an endoscope to illuminate a target with polarized light, the target comprising spatially distributed scattering elements;

using the endoscope to obtain images of light scattered from the target in response to the illuminating, wherein the scattered light images are obtained for each of a plurality of different wavelengths for each of a first polarization parallel to that for the illumination light and a second polarization perpendicular to that for the illumination light;

determining range information about a distance to the target from the endoscope;

analyzing the scattered light images and the range information to determine information about the size of the scattering elements at different spatial locations of the target; and

outputting the information about the size of the scattering elements.

11. The method of claim 10, wherein using the endoscope to illuminate the target comprises illuminating the target with a wavelength-tunable light source.

12. The method of claim 10, wherein using the endoscope to illuminate the target comprises illuminating the target with a broadband light source in series with a wavelength-tunable filter.

13. The method of claim 12, wherein said wavelength tunable filter is an acousto-optic tunable filter.

14. The method of claim 10, wherein using the endoscope to illuminate the target comprises illuminating the target with a broadband light source and wherein using the endoscope to obtain images comprises detecting reflected light with a detector whose wavelength acceptance can be chosen by interposing chromatic filters in the light path.

15. The method of claim 10, wherein using the endoscope to illuminate the target comprises illuminating the target with a broadband light source and wherein using the endoscope to obtain images comprises detecting reflected/scattered light with a wavelength-tunable filter in series with a detector.

16. The method of claim 15, wherein the wavelength-tunable filter is an acousto-optic tunable filter.

17. The method of claim 10, wherein determining range information comprises either optically, sonically or mechanically determining the range information.

18. The method of claim 10, wherein determining range information comprises:

illuminating a spot of said target with a collimated beam of known diameter and degree of collimation;

recording the size of the illuminated spot reflected from said target; and

calculating the distance to said target using the size of the illuminated spot and the known diameter and degree of collimation of the beam.

19. The method of claim 18, wherein determining range information comprises:

determining a topology of the illuminated region by analyzing a size and shape of an illuminated region.

20. The method of claim 10, wherein analyzing the scattered light images comprises an analysis based on a Mie theory.

21. The method of claim 10,

wherein the target comprises epithelial tissue having nuclei corresponding to the scattering elements, and

wherein the information about the size of the scattering elements at different spatial locations of the target comprises information about the size of the nuclei at different spatial locations of the epithelial tissue, and wherein the method further comprises

analyzing the information about the size of the nuclei to spatially resolve abnormality of cells of the epithelial tissue.

22. The method of claim 10, wherein the information is outputted as a map of the size of the scattering elements.