Skin optical characterization device

• US 20070060819A1
• Filed: 09/15/2006
• Published: 03/15/2007
• Est. Priority Date: 09/15/2005
• Status: Active Grant

• Current Assignee: Palomar Medical Technologies Incorporated (Hologic Incorporated)
• Original Assignee: Palomar Medical Technologies Incorporated (Hologic Incorporated)
• Inventors: Altshuler, Gregory, Zenzie, Henry, Wang, Guangming
• Granted Patent: US 8,346,347 B2
• Time in Patent Office: Days
• US Class Current: 600/475
• 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 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: A61B 5/444 Evaluating skin marks, e.g. mole, nevi, tumour, scar
• CPC Class Codes: A61B 5/445 Evaluating skin irritation or skin trauma, e.g. rash, eczema, wound, bed sore
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure

Abstract

The present invention is generally directed to dermatological devices and methods in which one or more skin characteristics, such as the melanin index, are determined by analyzing radiation backscattered from a skin region illuminated by at least one, and preferably, two or more wavelengths, e.g., in a range of about 600 nm to about 900 nm. In many embodiments, the radiation is coupled to the skin via a waveguide, and an optical sensor is employed to ascertain contact between the waveguide (e.g., a waveguide surface adapted for contact with the skin) and the skin.

Claims

1. A dermatological device for determining a physical characteristic of a portion of tissue, comprising:

a radiation source assembly configured to generate radiation having at least a first wavelength;

a waveguide coupled to said source assembly for directing the radiation from the source to said portion of said tissue, and having a surface configured to irradiate said portion with said radiation;

a detector coupled to said waveguide and configured to detect radiation from said source, said detector generating signals indicative of the level of radiation detected; and

a processor in communication with said detector to process said signals and calculate a physical characteristic of the skin region;

wherein said detector is configured to detect said radiation from said source after said portion of said tissue has been irradiated with said radiation from said source.

2. The device of claim 1, wherein said radiation source assembly includes two or more radiation sources.

3. The device of claim 2, wherein a first radiation source produces radiation having said first wavelength and wherein a second radiation source produces radiation having a second wavelength.

4. The device of claim 1, wherein said radiation source assembly includes a single radiation source.

5. The device of claim 4, wherein said first radiation source produces radiation having said first wavelength and further produces radiation having a second wavelength.

6. The device of claim 1, wherein said radiation source assembly includes at least one of a light emitting diode (LED), a bi-color LED, a tunable radiation source, and a laser radiation source.

7. The device of claim 1, wherein said radiation source assembly is configured to generate radiation having a second wavelength.

8. The device of claim 7 wherein said first and second wavelengths are selected from a range of about 350 nm to about 1200 nm.

9. The device of claim 7 wherein said first and second wavelengths are selected from a range of about 600 nm to about 900 nm.

10. The device of claim 1 wherein said first wavelength is selected from a range of about 350 nm to about 1200 nm.

11. The device of claim 1 wherein said first wavelength is selected from a range of about 600 nm to about 900 nm.

12. The device of claim 1, further comprising a contact sensor indicating whether said surface of the optical waveguide is in contact with the skin.

13. The device of claim 12, wherein said contact sensor is configured to detect a level of said radiation of said first wavelength.

14. The device of claim 13, wherein said contact sensor is configured to send a signal to said processor indicating that said surface of said waveguide is not in contact with said tissue when said contact sensor detects that said level is below a threshold.

15. The device of claim 13, wherein said contact sensor is configured to send a signal to said processor indicating that said surface of said waveguide is in contact with said tissue when said contact sensor detects that said level is above a threshold.

16. The device of claim 13, wherein said contact sensor is configured to send a signal to said processor indicating that said surface of said waveguide is not in contact with said tissue when said contact sensor detects that said level is above a threshold.

17. The device of claim 13, wherein said contact sensor is configured to send a signal to said processor indicating that said surface of said waveguide is in contact with said tissue when said contact sensor detects that said level is below a threshold.

18. The device of claim 12, wherein said contact sensor is optically coupled to said waveguide along a boundary and wherein said waveguide is configured to totally internally reflect said radiation along said boundary when said surface is not in contact with said tissue.

19. The device of claim 12, wherein said contact sensor is optically coupled to said waveguide along a boundary and wherein said waveguide is configured to not totally internally reflect said radiation along said boundary when said surface is in contact with said tissue.

20. The device of claim 12, wherein said contact sensor is optically coupled to said waveguide along a boundary and wherein said waveguide is configured to totally internally reflect said radiation along said boundary when said surface is in contact with said tissue.

21. The device of claim 12, wherein said contact sensor is optically coupled to said waveguide along a boundary and wherein said waveguide is configured to not totally internally reflect said radiation along said boundary when said surface is not in contact with said tissue.

22. The device of claim 12, wherein said radiation source assembly is configured to generate radiation having a second wavelength, and said contact sensor is configured to detect a level of said radiation of said first wavelength and of said second wavelength.

23. The device of claim 12, further comprising:

a first polarizer configured to filter radiation of a first polarity from said radiation source assembly; and

a second polarizer configured to filter radiation of a second polarity entering said contact sensor.

24. The device of claim 12, further comprising a filter disposed between the contact sensor and the waveguide.

25. The device of claim 1, wherein said radiation source assembly is configured to generate radiation having three or more wavelengths.

26. The device of claim 1, wherein said skin characteristic is selected from the group consisting of melanin index, collagen content, diffusion, and erythema measurement.

27. The device of claim 1 wherein said waveguide is formed of a material having an index of refraction in a range of about 1.4 to about 2.5.

28. The device of claim 1, further comprising:

a first polarizer configured to filter radiation of a first polarity from said radiation source assembly; and

a second polarizer configured to filter radiation of a second polarity entering said detector.

29. The device of claim 1, further comprising a filter disposed between said waveguide and said detector.

30. The device of claim 1, further comprising a controller coupled to said radiation source assembly, said controller configured to activate said radiation source assembly to produce radiation of different wavelengths at different times.

31. The device of claim 1, wherein said waveguide is an optical fiber.

32. The device of claim 1, further comprising at least one additional waveguide coupled to said source assembly.

33. The device of claim 32, wherein said at least one additional waveguide is an optical fiber.

34. A dermatological device for determining a physical characteristic of a portion of tissue, comprising

a radiation source assembly configured to generate radiation having first and second wavelengths;

a waveguide coupled to said source assembly for directing the radiation from the source to said portion of said tissue, and having a surface configured to irradiate said portion with said radiation;

a detector coupled to said waveguide and configured to detect radiation from said source, said detector generating signals indicative of the level of radiation detected;

a processor in communication with said detector to process said signals and calculate a physical characteristic of the skin region; and

a contact sensor optically coupled to said waveguide along a boundary and configured to detect a level of said radiation;

wherein said detector is configured to detect said radiation from said source after said portion of said tissue has been irradiated with said radiation from said source.

35. The device of claim 34, wherein said first and second wavelengths are in a range of about 300 nm to about 1200 nm.

36. The device of claim 34, wherein said first and second wavelengths are in a range of about 600 nm to about 900 nm.

37. The device of claim 34, wherein said first and second wavelengths are in a range of about 630 nm to about 730 nm.

38. The device of claim 34, wherein said first wavelength is approximately 645 nm.

39. The device of claim 34, wherein said first wavelength is approximately 700 nm.

40. The device of claim 34, wherein said first wavelength is approximately 645 nm and said second wavelength is approximately 700 nm.

41. The device of claim 34, wherein said waveguide surface adapted for contact with the tissue inhibits transmission of radiation in absence of skin contact by total internal reflection of radiation reflected by the sidewall thereto.

42. The device of claim 34, further comprising a feedback mechanism in communication with said sensor and said source, wherein said feedback mechanism is capable of inhibiting activation of the source when the sensor indicates lack of optical contact between the waveguide and the source, and capable of activating the source when the sensor indicates optical contact.

43. The device of claim 34, further comprising a processor in communication with the detector, said processor determining a skin characteristic based on said detector output.

44. The device of claim 34, wherein said waveguide is an optical fiber.

45. The device of claim 34, further comprising at least one additional waveguide.

46. A dermatological device, comprising

at least one radiation source,

a waveguide optically coupled to the radiation source to transmit radiation from the source to the skin, said waveguide having two opposed surfaces and a sidewall extending between said surfaces,

a detector coupled to the waveguide to detect at least a portion of radiation backscattered from a skin region illuminated by the source radiation, and

an optical contact sensor optically coupled to said sidewall, said sensor determining whether said waveguide is in contact with the skin based on detection of backscattered radiation leaking through said sidewall.

47. A dermatological device, comprising:

a radiation source assembly;

a first waveguide having a proximal end adapted to receive radiation from the radiation source assembly and a distal end adapted to transmit radiation to a tissue;

a second waveguide having a distal end adapted to receive backscattered radiation from said first waveguide and a proximal end adapted to transmit said backscattered radiation;

a detector optically coupled to said second waveguide and configured to measure a physical characteristic of said tissue; and

a processor electrically coupled to the detector and configured to receive a signal from said detector corresponding to said backscattered radiation;

wherein said processor is configured to determine a physical characteristic of said tissue based on the backscattered radiation that is detected.

48. The device of claim 47, wherein the device further comprises a means for coupling said backscattered radiation exiting from said proximal end to the detector.

49. The device of claim 48, wherein said means comprises a beamsplitter.

50. The device of claim 47, wherein the radiation source assembly is capable of generating radiation at two or more wavelengths in a range of about 350 nm to about 1200 nm.

51. The device of claim 47, wherein the radiation source assembly is capable of generating radiation at two or more wavelengths in a range of about 600 nm to about 900 nm.

52. The device of claim 47, wherein the first waveguide is an optical fiber.

53. The device of claim 47, wherein the second waveguide is an optical fiber.

54. The device of claim 47, further comprising additional waveguides

55. The device of claim 54, wherein said additional waveguides are optical fibers.

56. A dermatological device, comprising

at least one source of radiation,

an optical fiber receiving radiation from said source at a proximal end and applying the radiation to a skin region at a distal end,

another optical fiber coupled at a distal end to skin at another region separated from the illuminated region by a skin segment so as to receive at least a portion of the applied radiation after transmission through that segment,

a detector optically coupled to a proximal end of said another optical fiber to detect at least a portion of said transmitted radiation received by that fiber, said detector generating a signal indicative of an intensity of said received radiation, and

a processor operating on said detector signal to determining a skin characteristic.

57. A method of determining a characteristic of tissue comprising:

applying radiation of first and second wavelengths from a waveguide to said tissue;

detecting at least a portion of radiation of said first and second wavelengths backscattered from said tissue

generating at least one signal indicative of an intensity of the backscattered radiation, and

processing said at least one signal to calculate a characteristic of the skin region.

58. The method of claim 57, wherein the step of applying radiation further comprises applying radiation at a plurality of wavelengths selected from a range of about 350 nm to about 1200 nm. to the skin.

59. The method of claim 57, wherein the step of applying radiation further comprises applying radiation at a plurality of wavelengths selected from a range of about 600 nm to about 900 nm.

60. The method of claim 57, further comprising detecting optical contact between the waveguide and the skin region.

61. The method of claim 57, further comprising sensing contact of said waveguide with said tissue by detecting a level of said backscattered radiation.

62. The method of claim 57, further comprising reducing ambient radiation to prevent its detection by the detector.

63. The method of claim 64, further comprising:

reducing radiation having a first polarity prior to detection; and

detecting radiation having a second polarity.