Optical fiber probe and methods for measuring optical properties

• US 6,678,541 B1
• Filed: 10/28/1999
• Issued: 01/13/2004
• Est. Priority Date: 10/28/1998
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: The Governmemt of The United States of America
• Inventors: Durkin, Anthony J., Ediger, Marwood, Matchette, L. Stephanie
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): KREMER, MATTHEW J
• Application Number:
  US09/428,832
• Time in Patent Office: 1,538 Days
• Field of Search: 600/473, 600/476, 600/309-344, 600/369, 356/39-42, 356/300, 356/343, 356/369, 356/435, 356/445, 356/330-334, 250/493.1, 250/494.1, 250/495.1
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/046 in a matrix array
• 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: G01N 2021/4709 Backscatter
• CPC Class Codes: G01N 2021/4742 comprising optical fibres
• CPC Class Codes: G01N 2021/4747 Concentric bundles
• CPC Class Codes: G01N 21/474 Details of optical heads therefor, e.g. using optical fibres

Abstract

A probe for the characterization of optical properties, including scattering and absorption properties of a sample, such as medical and industrial samples, includes an illumination fiber to radiate light toward an object and at least two collection fibers to receive light diffusely reflected from the object. At least two of the collection fibers are spaced at different distances from the illumination fiber. A region of the sample is illuminated with light from the illumination fiber. A portion of the light is diffusely reflected by the region. A portion of the diffusely reflected light is received by the two or more collection fibers. The region is characterized based on an amount of light received by each of the collection fibers. When the method is used for medical purposes, the characterization of the region may be used to make a diagnosis.

Claims

1. A probe assembly comprising:

a probe comprising;

an illumination fiber to radiate light in a wavelength range of about 200 to about 800 nm toward an object;

a plurality of collection fibers spatially separated from the illumination fiber to receive light from the object; and

at least one spacer;

wherein at least two of the collection fibers are at different distances from the illumination fiber, wherein each individual collection fiber is spatially separated from every other collection fiber by at least one of said spacers, wherein said probe is utilized to calculate at least a scattering coefficient of said light from said object, and wherein said scattering coefficient is utilized to characterize a region of said object,

wherein the illumination fiber and the collection fibers form a linear arrangement and the illumination fiber is located at one end of the linear arrangement;

a light source; and

a detector for calculating at least a scattering coefficient of the light received by the collection fibers, wherein said scattering coefficient is utilized to characterize a region of said object.

2. The probe assembly of claim 1, wherein the detector is configured and arranged to measure an intensity of the light received by the collection fibers.

3. The probe assembly of claim 1, further comprising a processor to analyze the light received by the collection fibers.

4. The probe assembly of claim 3, wherein the processor is configured and arranged to calculate a scattering coefficient from the light received by the collection fibers.

5. The probe assembly of claim 1, wherein the light source produces two or more wavelengths of light.

6. The probe assembly of claim 1, wherein the light source comprises a laser or a lamp.

7. The probe assembly of claim 1, wherein a detector is configured and arranged to detect light in a wavelength range of from about 200 to 800 nm.

8. The probe assembly of claim 1, wherein the detector comprises a detector array and a spectrograph.

9. The probe assembly of claim 8, wherein the detector array comprises an array of charge-coupled devices.

10. The probe assembly of claim 1, wherein the illumination fiber and the collection fibers are fabricated within a non-fluorescent housing.

11. The probe assembly of claim 1, wherein the collection fibers are located at regular intervals from the illumination fiber.

12. The probe assembly of claim 1, wherein said at least one spacer comprises a fiber.

13. The probe assembly of claim 1, further comprising a spacer between the illumination fiber and a nearest collection fiber.

14. The probe assembly of claim 1, further comprising a spacer between each of the collection fibers.

15. The probe assembly of claim 1, wherein the number of collection fibers ranges from 5 to 15.

16. The probe assembly of claim 1, wherein the collection fibers extend about 3 to 8 mm from the illumination fiber.

17. The probe assembly of claim 1, wherein the diameter of the collection fibers ranges from about 50 μ

m to about 400 μ

m.

18. A probe assembly comprising:

a probe comprising;

an illumination fiber to radiate light in a wavelength range of about 200 to about 800 nm toward an object;

a plurality of collection fibers spatially separated from the illumination fiber to receive light from the object; and

at least one spacer;

wherein at least two of the collection fibers are at different distances from the illumination fiber, wherein each individual collection fiber is spatially separated from every other collection fiber by at least one of said spacers, wherein said probe is utilized to calculate at least a scattering coefficient of said light from said object, and wherein said scattering coefficient is utilized to characterize a region of said object,

wherein the collection fibers are arranged in a plurality of concentric circles about the illumination fiber;

a light source; and

a detector for calculating at least a scattering coefficient of the light received by the collection fibers, wherein said scattering coefficient is utilized to characterize a region of said object.

19. The probe assembly of claim 18, wherein the detector is configured and arranged to measure an intensity of the light received by the collection fibers.

20. The probe assembly of claim 18, further comprising a processor to analyze the light received by the collection fibers.

21. The probe assembly of claim 20, wherein the processor is configured and arranged to calculate a scattering coefficient from the light received by the collection fibers.

22. The probe assembly of claim 18, wherein the light source produces two or more wavelengths of light.

23. The probe assembly of claim 18, wherein the light source comprises a laser or a lamp.

24. The probe assembly of claim 18, wherein a detector is configured and arranged to detect light in a wavelength range of from about 200 to 800 nm.

25. The probe assembly of claim 18, wherein the detector comprises a detector array and a spectrograph.

26. The probe assembly of claim 25, wherein the detector array comprises an array of charge-coupled devices.

27. The probe assembly of claim 18, wherein the illumination fiber and the collection fibers are fabricated within a non-fluorescent housing.

28. The probe assembly of claim 18, wherein the collection fibers are located at regular intervals from the illumination fiber.

29. The probe assembly of claim 18, wherein said at least one spacer comprises a fiber.

30. The probe assembly of claim 18, further comprising a spacer between the illumination fiber and a nearest collection fiber.

31. The probe assembly of claim 18, further comprising a spacer between each of the collection fibers.

32. The probe assembly of claim 18, wherein the number of collection fibers ranges from 5 to 15.

33. The probe assembly of claim 18, wherein the collection fibers extend about 3 to 8 mm from the illumination fiber.

34. The probe assembly of claim 18, wherein more than one collection fiber is at a same distance from the illumination fiber.

35. The probe assembly of claim 18, wherein the diameter of the collection fibers ranges from about 50 μ

m to about 400 μ

m.

36. A method for characterizing a region of a sample comprising:

illuminating a region of a sample with light in a wavelength range of about 200 to about 800 nm from an illumination fiber;

diffusely reflecting a portion of the light that illuminates the region;

receiving a portion of the diffusely reflected light at a plurality of collection fibers, wherein at least two of the collection fibers are at different distances from the illumination fiber, and wherein the collection fibers are spatially separated by spacers;

combining the portion of diffusely reflected light collected at two or more collection fibers; and

characterizing the region based on at least a calculated scattering coefficient of the diffusely reflected light received by each of the collection fibers.

37. The method of claim 36, wherein the illumination fiber and the collection fibers form a linear arrangement.

38. The method of claim 36, wherein the two or more collection fibers from which the amount of light is combined are at a same radial distance from the illumination fiber.

39. The method of claim 36, further comprising determining the scattering coefficient from an amount of diffusely reflective light received by each of the collection fibers.

40. The method of claim 36, further comprising moving the illumination and collection fibers along the surface of the sample to characterize the sample.

41. The method of claim 36, wherein illuminating a region of the sample with light comprises illuminating the sample with more than one wavelength of light.

42. A method for characterizing a region of a sample comprising:

illuminating a region of a sample with light in a wavelength range of about 200 to about 800 nm from an illumination fiber;

diffusely reflecting a portion of the light that illuminates the region;

receiving a portion of the diffusely reflected light at a plurality of collection fibers, wherein at least two of the collection fibers are at different distances from the illumination fiber, and wherein the collection fibers are spatially separated by spacers;

combining the portion of diffusely reflected light collected at two or more collection fibers;

characterizing the region based on at least a calculated scattering coefficient of the diffusely reflected light received by each of the collection fibers; and

making a diagnosis regarding the region.

43. The method of claim 42, wherein illuminating a region of the sample comprises illuminating the sample with more than one wavelength of light.

44. The method of claim 42, wherein characterizing the region comprises calculating a scattering coefficient from a portion of the diffusely reflected light received from the individual collection fibers.

45. The method of claim 44, wherein making a diagnosis comprises comparing the scattering coefficient to known values for different types of tissue.

46. The method of claim 42, further comprising moving the illumination and collection fibers along the surface of the sample to characterize a plurality of regions of the sample.