Method and apparatus for diagnosing bone tissue conditions

• US 8,417,322 B2
• Filed: 06/29/2004
• Issued: 04/09/2013
• Est. Priority Date: 07/01/2003
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Morris, Michael D., Goldstein, Steven A., McCreadie, Barbara R., Chen, Tso-Ching
• Primary Examiner(s): Cwern, Jonathan
• Application Number:
  US10/879,797
• Publication Number:
  US 20050010130A1
• Time in Patent Office: 3,206 Days
• Field of Search: 600/477
• US Class Current: 600/477
• 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 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4509 Bone density determination
• CPC Class Codes: A61B 5/4514 Cartilage
• CPC Class Codes: A61B 5/4523 Tendons
• CPC Class Codes: A61B 5/4533 Ligaments
• CPC Class Codes: G01N 2021/656 Raman microprobe
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/65 Raman scattering

Abstract

In a method for diagnosing or helping to diagnose a bone tissue condition of a patient, a portion of bone tissue of the patient is irradiated using a light source. The bone tissue may be irradiated in vivo through the skin or via an incision, for example. Alternatively, a biopsy of the bone tissue may be irradiated. Then, spectral content information for light scattered, reflected, or transmitted by the bone tissue is determined, and is used, at least in part, to determine whether the patient has a bone tissue condition.

Claims

1. A method for determining whether a patient has a condition related to bone tissue of the patient, the method comprising:

irradiating a portion of bone tissue of the patient through skin of the patient using a substantially monochromatic light source;

receiving light scattered from the portion of the bone tissue;

determining Raman spectral content information associated with the received light including measuring a first ratio of a first spectral portion corresponding to amide to a second spectral portion corresponding to amide; and

determining, based at least on the Raman spectral content information, including the first ratio, whether the patient has a bone tissue condition.

2. A method as defined in claim 1, wherein irradiating the portion of bone tissue of the patient using the substantially monochromatic light source comprises irradiating the portion of bone tissue of the patient using a substantially monochromatic light source that produces light having a wavelength substantially between 700 nanometers and 1100 nanometers.

3. A method as defined in claim 2, wherein irradiating the portion of bone tissue of the patient using the substantially monochromatic light source comprises irradiating the portion of bone tissue of the patient using a substantially monochromatic light source that produces light having a wavelength of substantially 830 nanometers.

4. A method as defined in claim 1, wherein irradiating the portion of bone tissue of the patient comprises irradiating the portion of bone tissue in vivo.

5. A method as defined in claim 1, wherein determining whether the patient has the bone tissue condition comprises determining whether the patient has at least one of a susceptibility to fracture, osteoporosis, a genetic disorder, and an acquired disorder.

6. A method as defined in claim 1, wherein determining whether the patient has a bone tissue condition comprises estimating a susceptibility to fracture of bone tissue of the patient based at least in part on the Raman spectral content information.

7. A method as defined in claim 6, wherein the Raman spectral content information includes a plurality of bands corresponding to received light at one or more wavelengths;

wherein estimating the susceptibility to fracture includes determining at least one area or height of at least one band.

8. A method as defined in claim 7, wherein estimating the susceptibility to fracture further comprises fitting a curve to the at least one band.

9. A method as defined in claim 7, wherein determining the first ratio comprises:

determining a first area or height of at least a first band;

determining a second area or height of at least a second band; and

determining the first ratio using the first area or height and the second area or height.

10. A method as defined in claim 9, wherein estimating the susceptibility to fracture further comprises estimating the susceptibility to fracture based on the first ratio.

11. A method as defined in claim 9, wherein estimating the susceptibility to fracture further comprises:

determining a third area or height of at least a third band;

determining a second ratio of the third area or height and the first area or height.

12. A method as defined in claim 11, wherein estimating the susceptibility to fracture further comprises estimating the susceptibility to fracture based on the first ratio and the second ratio.

13. A method as defined in claim 6, wherein estimating the susceptibility to fracture further comprises estimating the susceptibility to fracture further based at least in part on at least one of an age of the patient, a height of the patient, a weight of the patient, a bone mineral density of the patient, and a family history of the patient.

14. A method as defined in claim 1, wherein determining whether the patient has a bone tissue condition comprises determining whether the patient has a bone tissue condition further based at least in part on at least one of an age of the patient, a height of the patient, a weight of the patient, a bone mineral density of the patient, and a family history of the patient.

15. A method as defined in claim 1, wherein the first spectral portion and the second spectral portion each correspond to amide I.

16. A method as defined in claim 15, wherein the first spectral portion is at 1680 cm⁻

1 to 1690 cm<sup>−

1</sup>;

wherein the second spectral portion is at 1665 cm<sup>−

1</sup>.

17. A method as defined in claim 1, wherein determining Raman spectral content information associated with the received light comprises measuring a second ratio of a first spectral portion corresponding to carbonate to a second spectral portion corresponding to phosphate;

and

wherein determining whether the patient has the bone tissue condition is further based on the second ratio.

18. A method as defined in claim 17, wherein the first spectral portion corresponds to carbonate ν

₁; and

wherein the second spectral portion corresponds to phosphate ν

₁.

19. A method as defined in claim 18, wherein the first spectral portion is at 1070 cm⁻

1; and

wherein the second spectral portion is at 957 cm<sup>−

1</sup> with a shoulder at 940 cm<sup>−

1</sup>.

20. A method as defined in claim 17, wherein determining Raman spectral content information associated with the received light comprises measuring a third ratio of a third spectral portion corresponding to phosphate to a fourth spectral portion corresponding to amide;

and

wherein determining whether the patient has the bone tissue condition is further based on the third ratio.

21. A method as defined in claim 20, wherein the third spectral portion corresponds to phosphate ν

₁.

22. A method as defined in claim 21, wherein the third spectral portion is at 23 cm⁻

1 with a shoulder at 940 cm<sup>−

1</sup>.

23. A method as defined in claim 20, wherein the fourth spectral portion corresponds to amide I.

24. A method as defined in claim 23, wherein the fourth spectral portion corresponds to a plurality of amide I bands between 25 cm⁻

1 to 1700 cm<sup>−

1</sup>.

25. A method as defined in claim 20, wherein the fourth spectral portion corresponds to amide III.

26. A method as defined in claim 25, wherein the fourth spectral portion corresponds to a plurality of amide III bands.

27. An apparatus for determining bone tissue susceptibility to fracture, comprising:

a substantially monochromatic light source;

an optical probe optically coupled to the substantially monochromatic light source and configured to irradiate a portion of bone tissue of a patient through skin of the patient and to receive light scattered from the portion of bone tissue;

a spectrum analyzer optically coupled to receive light received by the optical probe, the spectrum analyzer configured to generate Raman spectral content information associated with the received light; and

a computing device communicatively coupled to the spectrum analyzer, the computing device configured to;

measure, in the Raman spectral content information, a first ratio of a first spectral portion corresponding to amide to a second spectral portion corresponding to amide, and

generate diagnostic information indicative of whether the patient has a bone tissue condition based at least in part on the Raman spectral content information, including the first ratio.

28. An apparatus as defined in claim 27, wherein the light source produces light having a wavelength substantially between 700 nanometers and 1100 nanometers.

29. An apparatus as defined in claim 27, wherein the computing device comprises a digital circuit.

30. An apparatus as defined in claim 27, wherein the computing device comprises an analog circuit.

31. An apparatus as defined in claim 27, wherein the computing device comprises a mixed analog and digital circuit.

32. An apparatus as defined in claim 27, wherein the computing device comprises a processor coupled to a memory.

33. An apparatus as defined in claim 27, wherein the bone tissue condition comprises at least one of a susceptibility to fracture, osteoporosis, a genetic disorder, and an acquired disorder.

34. An apparatus as defined in claim 27, wherein the computing device is configured to estimate a susceptibility to fracture of bone tissue of the patient based at least in part on the Raman spectral content information.

35. An apparatus as defined in claim 34, wherein the Raman spectral content information includes a plurality of bands corresponding to received light at one or more wavelengths;

wherein the computing device is configured to determine at least one area or height of at least one band.

36. An apparatus as defined in claim 35, wherein the computing device is configured to fit a curve to the at least one band.

37. An apparatus as defined in claim 35, wherein the computing device is configured to determine a first area or height of at least a first band;

wherein the computing device is configured to determine a second area or height of at least a second band; and

wherein the computing device is configured to determine the first ratio using the first area or height and the second area or height.

38. An apparatus as defined in claim 37, wherein the computing device is configured to estimate the susceptibility to fracture based at least in part on the first ratio.

39. An apparatus as defined in claim 37, wherein the computing device is configured to determine a third area or height of at least a third band;

wherein the computing device is configured to determine a second ratio of the third area or height and the first area or height.

40. An apparatus as defined in claim 39, wherein the computing device is configured to estimate the susceptibility to fracture based at least in part on the first ratio and the second ratio.

41. An apparatus as defined in claim 34, wherein the computing device is configured to estimate the susceptibility to fracture further based at least in part on at least one of an age of the patient, a height of the patient, a weight of the patient, a bone mineral density of the patient, and a family history of the patient.

42. An apparatus as defined in claim 27, wherein the computing device is configured to generate diagnostic information further based at least in part on at least one of an age of the patient, a height of the patient, a weight of the patient, a bone mineral density of the patient, and a family history of the patient.

43. A method for determining bone tissue susceptibility to fracture, the method comprising:

irradiating a portion of bone tissue of a patient using a light source;

receiving light scattered from the portion of the bone tissue;

determining Raman spectra information from the received scattered light including measuring a ratio of a first spectral portion corresponding to amide to a second spectral portion corresponding to amide;

determining a level of bone fracture risk of the patient based at least in part on the Raman spectra information, including the ratio, wherein the level of bone fracture risk is from a plurality of risk levels including a plurality of above-normal risk levels.

44. An apparatus for determining bone tissue susceptibility to fracture, comprising:

a light source;

a Raman probe to receive light scattered from a portion of bone tissue of a patient irradiated by the light source;

a spectrum analyzer coupled to receive light received by the light receiver and to determine Raman spectra information for the received light; and

a computing device coupled to the spectrum analyzer, the computing device configured to;

measure, in the Raman spectra information, a ratio of a first spectral portion corresponding to amide to a second spectral portion corresponding to amide, and

determine a level of bone fracture risk of the patient based at least in part on the Raman spectra information, including the ratio, wherein the level of bone fracture risk is from a plurality of risk levels including a plurality of above-normal risk levels.