Diffractive imaging system and method for the reading and analysis of skin topology

• US 20060119837A1
• Filed: 10/14/2005
• Published: 06/08/2006
• Est. Priority Date: 10/16/2004
• Status: Active Grant

• Current Assignee: Aprilis, Inc.
• Original Assignee: Aprilis, Inc.
• Inventors: Malyak, Phillip H., Waldman, David A., Raguin, Daniel H., Ingwall, Richard T., Berg, John S.
• Granted Patent: US 7,787,110 B2
• Time in Patent Office: Days
• US Class Current: 356/71
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence

Abstract

An apparatus and a method for acquiring an image of skin topology. The apparatus comprises at least one light source, configured to form a source beam; at least one illuminating diffractive optical element (DOE) disposed in the optical path of the source beam, configured to diffract the source beam, thereby forming an illuminating beam; a skin contact surface, disposed in the optical path of the illuminating beam, configured to at least partially reflect the illuminating beam at regions of the boundary between the skin contact surface and skin that are not in contact with skin, thereby forming a reflected beam; at least one imaging diffractive optical element (DOE), disposed in the optical path of the reflected beam, configured to diffract the reflected light beam, thereby forming an image beam; and a sensor array, configured to receive at least a portion of the image beam and thereby to detect the acquired image.

Claims

1. An apparatus for acquiring an image of skin topology, comprising:

at least one light source, configured to form a source beam;

at least one illuminating diffractive optical element (DOE) disposed in the optical path of the source beam, configured to diffract the source beam, thereby forming an illuminating beam;

a skin contact surface, disposed in the optical path of the illuminating beam, configured to at least partially reflect the illuminating beam at regions of the boundary between the skin-contact surface and skin that are not in contact with skin, thereby forming a reflected beam;

at least one imaging diffractive optical element (DOE), disposed in the optical path of the reflected beam, configured to diffract the reflected light beam, thereby forming an image beam; and

a sensor array, configured to receive at least a portion of the image beam and thereby to detect the acquired image.

2. The apparatus of claim 1, wherein the illumination DOE is configured to reconstruct the source beam, and the imaging DOE is configured to reconstruct the reflected beam.

3. The apparatus of claim 1, wherein at least one illumination DOE and at least one imaging DOE are spatially separated.

4. The apparatus of claim 1, wherein at least one illumination DOE and at least one imaging DOE are co-locationally multiplexed.

5. The apparatus of claim 1, wherein the illumination DOE is configured so that the illuminating beam totally internally reflects at the regions of the boundary between the skin-contact surface and skin that are not in contact with skin.

6. The apparatus of claim 5, wherein the skin-contact surface comprises a hydrophilic layer.

7. The apparatus of claim 5, wherein the skin-contact surface comprises a plurality of separable hydrophilic layers disposed in a stack.

8. The apparatus of claim 1, further including imaging optics disposed in the optical path of the image beam, said imaging optics configured to relay the image beam to the sensor array.

9. The apparatus of claim 8, wherein the imaging DOE focuses the image beam, thereby serving as an objective lens for the imaging optics.

10. The apparatus of claim 9, wherein the imaging optics has variable optical power.

11. The apparatus of claim 10, wherein the imaging optics relays an image beam of variable optical resolution to the sensor.

12. The apparatus of claim 1, wherein the illumination DOE is polarization-sensitive.

13. The apparatus of claim 1, wherein the imaging DOE is polarization-sensitive.

14. The apparatus of claim 1, further including at least one mirror configured to relay the source beam to the illumination DOE and to relay the image beam to the sensor array.

15. The apparatus of claim 1, further including a spectral filter disposed in the optical path of one or more beams selected from the group of the source beam, the illuminating beam, the reflected beam, and the image beam.

16. The apparatus of claim 15, wherein the spectral filter transmits light of the wavelengths emitted by the light source.

17. The apparatus of claim 16, wherein the spectral filter is a dichroic filter or an absorbance filter.

18. The apparatus of claim 1, further including a linear polarizer filter disposed in the optical path of one or more beams selected from the group of the source beam, the illuminating beam, the reflected beam, and the image beam.

19. The apparatus of claim 1, wherein the light source is selected from the group consisting of a laser diode, an LED, a filament lamp, and a fluorescent lamp.

20. The apparatus of claim 1, wherein the light source is a laser diode or an LED.

21. The apparatus of claim 1, comprising a plurality of light sources.

22. The apparatus of claim 21, wherein said light sources have low coherence with respect to each other.

23. The apparatus of claim 1, further including a programmable processor programmed to perform image processing.

24. The apparatus of claim 1, further including data storage for storing acquired images.

25. The apparatus of claim 1, further including a detection system for detecting an object in contact with the skin contact surface.

26. The apparatus of claim 1, wherein the sensor array is a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detector array.

27. A method of acquiring an image of skin topology, comprising:

directing a source beam from a light source to at least one illuminating diffractive optical element (DOE), thereby diffracting the source beam and forming an illuminating beam;

directing the illuminating beam at a skin contact surface, configured to at least partially reflect the illuminating beam when the skin contact surface is not in contact with skin, thereby at least partially reflecting the illuminating beam and forming a reflected beam;

directing the reflected beam to at least one imaging diffractive optical element (DOE), thereby diffracting the reflected light beam and forming an image beam; and

directing the image beam at a sensor array, thereby detecting the acquired image.

28. The method of claim 27, wherein the illumination DOE is configured so that the illuminating beam totally internally reflects at the regions of the boundary between the skin-contact surface and skin that are not in contact with skin.

29. The method of claim 27, wherein the illumination DOE is configured to reconstruct the source beam, and the imaging DOE is configured to reconstruct the reflected beam.

30. The method of claim 27, wherein at least one illumination DOE and at least one imaging DOE are spatially separated.

31. The method of claim 27, wherein at least one illumination DOE and at least one imaging DOE are co-locationally multiplexed.

32. The method of claim 27, further including directing the image beam at imaging optics, thereby relaying the image beam to the sensor array.

33. The method of claim 32, wherein the imaging DOE focuses the image beam, thereby serving as an objective lens for the imaging optics.

34. The method of claim 32, wherein the imaging optics has variable optical power.

35. The method of claim 34, wherein the imaging optics relays an image beam of variable resolution to the sensor.

36. The method of claim 27, further including directing the source beam to at least one mirror, thereby relaying the source beam to the illumination DOE.

37. The method of claim 27, further including directing the image beam to at least one mirror, thereby relaying the image beam to the sensor array.

38. The method of claim 27, further including directing one or more beams selected from the group of the source beam, the illuminating beam, the reflected beam, and the image beam at a spectral filter.

39. The method of claim 38, wherein the spectral filter is a dichroic filter or a absorbance filter.

40. The method of claim 27, further including directing one or more beams selected from the group of the source beam, the illuminating beam, the reflected beam, and the image beam at a linear polarizer filter.

41. The method of claim 27 wherein at least on the diffractive optical elements are polarization-sensitive.

42. The method of claim 27, further including performing image processing by a programmable processor.

43. The method of claim 27, further including storing acquired images in a data storage device.

44. The method of claim 27, further including detecting an object in contact with the skin contact surface by a detection system.

45. An apparatus for acquiring an image of skin topology, comprising:

light generating means for forming a source beam;

illuminating diffractive means disposed in the optical path of the source beam, for diffracting the source beam and thereby forming an illuminating beam;

skin contacting means, disposed in the optical path of the illuminating beam, for at least partially reflecting the illuminating beam at regions of the boundary between the skin contact means and skin that are not in contact with skin, thereby forming a reflected beam;

at least one imaging diffractive means, disposed in the optical path of the reflected beam, for diffracting the reflected light beam and thereby forming an image beam; and

detection means for receiving at least a portion of the image beam and thereby detecting the acquired image.