Multispectral biometric sensor

• US 7,819,311 B2
• Filed: 05/18/2006
• Issued: 10/26/2010
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Lumidigm Incorporated (Assa Abloy AB)
• Inventors: Harbour, Robert M., Rowe, Robert K., Sidlauskas, David P.
• Primary Examiner(s): Frech; Karl D.
• Application Number:
  US11/437,388
• Publication Number:
  US 20060202028A1
• Time in Patent Office: 1,622 Days
• Field of Search: 235/380, 235/382, 235/454, 382/115, 382/116, 382/124, 382/125, 382/191, 902/3, 902/5, 705/18, 705/44
• US Class Current: 235/382
• CPC Class Codes: A61B 5/1171 based on the shapes or appearances of their bodies or parts thereof
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14558 by polarisation
• CPC Class Codes: B60K 28/06 responsive to incapacity of driver
• CPC Class Codes: B60R 25/252 Fingerprint recognition
• CPC Class Codes: B60W 2540/22 Psychological state; Stress level or workload
• CPC Class Codes: B60W 2540/221 Physiology, e.g. weight, heartbeat, health or special needs
• CPC Class Codes: B60W 2540/24 Drug level, e.g. alcohol
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G06V 40/1341 Sensing with light passing through the finger
• CPC Class Codes: G06V 40/14 Vascular patterns

Abstract

Methods and systems are provided for biometric sensing. An illumination subsystem provides light at discrete wavelengths to a skin site of an individual. A detection subsystem receives light scattered from the skin site. A computational unit is interfaced with the detection system. The computational unit has instructions for deriving a spatially distributed multispectral image from the received light at the discrete wavelengths. The computational unit also has instructions for comparing the derived multispectral image with a database of multispectral images to identify the individual.

Claims

1. A sensor system comprising:

an illumination subsystem disposed to provide illumination light to a skin site of an individual;

a detection subsystem disposed to receive light scattered from the skin site; and

a computational unit interfaced with the detection subsystem and having;

instructions for deriving a plurality of spatially distributed multispectral images from the received light, the plurality of spatially distributed multispectral images corresponding to different volumes of illuminated tissue of the individual; and

instructions for identifying the individual from the derived plurality of multispectral images.

2. The sensor system recited in claim 1 wherein the instructions for identifying the individual comprise instructions for searching a database of images for an entry identifying an image consistent with the derived plurality of multispectral images.

3. The sensor system recited in claim 1 wherein the instructions for identifying the individual comprise instructions for comparing the derived plurality of multispectral images with an image at an entry of a database of images corresponding to a purported identity of the individual to verify the purported identity.

4. The sensor system recited in claim 1 wherein the illumination subsystem comprises:

a light source that provides the illumination light; and

illumination optics to direct the illumination light to the skin site.

5. The sensor system recited in claim 4 wherein the illumination subsystem further comprises a scanner mechanism to scan the illumination light in a specified pattern.

6. The sensor system recited in claim 4 wherein the light source comprises a plurality of quasimonochromatic light sources.

7. The sensor system recited in claim 4 wherein the illumination subsystem comprises

a broadband light source.

8. The sensor system recited in claim 4 wherein the detection subsystem comprises:

a light detector; and

detection optics to direct the received light to the light detector.

9. The sensor system recited in claim 8 wherein:

the illumination subsystem further comprises a first polarizer disposed to encounter light emitted from the light source; and

the detection subsystem further comprises a second polarizer disposed to encounter the received light.

10. The sensor system recited in claim 9 wherein the first and second polarizers comprise circular polarizers.

11. The sensor system recited in claim 9 wherein the first and second polarizers comprise linear polarizers.

12. The sensor system recited in claim 11 wherein the first and second polarizers are substantially crossed relative to each other.

13. The sensor system recited in claim 1 further comprising a platen disposed to contact the skin site.

14. The sensor system recited in claim 13 wherein the platen is adapted for the skin site to be swiped over a surface of the platen.

15. The sensor system recited in claim 14 further comprising a roller system over which the skin site may be rolled, wherein the instructions for deriving the plurality of spatially distributed multispectral images include instructions for building up the plurality of multispectral images from light received from different portions of the skin site as the skin site is rolled.

16. The sensor system recited in claim 1 wherein the computational unit further has:

instructions for deriving spectral-distribution characteristics from the received light; and

instructions for comparing the derived spectral-distribution characteristics with a database of spectral-distribution characteristics.

17. The sensor system recited in claim 16 wherein the computational unit further has instructions for determining an analyte concentration in tissue below a surface of the skin site from the derived spectral-distribution characteristics.

18. The sensor system recited in claim 16 wherein the computational unit further has instructions for determining a liveness state of the tissue from the derived multispectral characteristics.

19. The sensor system recited in claim 1 wherein:

the skin site comprises a volar surface of a fingertip or hand; and

the instructions for identifying the individual from the derived plurality of multispectral images comprise instructions for deriving a fingerprint of the volar surface from the derived plurality of multispectral images.

20. A method for identifying an individual, the method comprising:

illuminating a skin site of the individual with illumination light;

receiving light scattered from the skin site;

deriving a plurality of spatially distributed multispectral image from the received light, the plurality of spatially distributed multispectral images corresponding to different volumes of illuminated tissue of the individual; and

identifying the individual from the derived plurality of multispectral images.

21. The method recited in claim 20 wherein identifying the individual comprises searching a database of images for an entry identifying an image consistent with the derived plurality of multispectral images.

22. The method recited in claim 20 wherein identifying the individual comprises comparing the derived plurality of multispectral images with an image at an entry of a database of multispectral images corresponding to a purported identity of the individual to verify the purported identity.

23. The method recited in claim 20 wherein illuminating the skin site of the individual with illumination light comprises scanning the illumination light in a specified pattern.

24. The method recited in claim 20 wherein illuminating the skin site of the individual with illumination light comprises generating the illumination light as a plurality of quasimonochromatic beams.

25. The method recited in claim 20 wherein illuminating the skin site of the individual with illumination light comprises

generating a broadband beam of light.

26. The method recited in claim 20 wherein:

illuminating the skin site further comprises polarizing the illumination light with a first polarization; and

receiving the light comprises polarizing the received light with a second polarization.

27. The method recited in claim 26 wherein the first and second polarizations are substantially crossed relative to each other.

28. The method recited in claim 20 further comprising:

deriving spectral-distribution characteristics from the received light; and

determining an analyte concentration in tissue below a surface of the skin site from the derived spectral-distribution characteristics.

29. The method recited in claim 20 further comprising:

deriving spectral-distribution characteristics from the received light; and

determining a liveness state from the derived multispectral characteristics.

30. The method recited in claim 20 further comprising:

deriving spectral-distribution characteristics from the received light; and

comparing the derived spectral-distribution characteristics with a database of spectral-distribution characteristics.

31. The sensor system recited in claim 20 wherein:

the skin site comprises a volar surface of a fingertip or hand; and

identifying the individual from the derived plurality of multispectral images comprises deriving a fingerprint of the volar surface from the derived plurality of multispectral images.

32. A sensor system comprising:

an illumination subsystem disposed to provide light at a plurality of discrete wavelengths to a skin site of an individual;

a detection subsystem disposed to receive light scattered from the skin site; and

a computational unit interfaced with the detection subsystem and having;

instructions for deriving a plurality of spatially distributed multispectral images from the received light at the plurality of discrete wavelengths, the plurality of spatially distributed multispectral images corresponding to different volumes of illuminated tissue of the individual; and

searching a database of images for an entry identifying an image consistent with the derived plurality of multispectral images.

33. The sensor system recited in claim 32 wherein:

the database of images includes multispectral images.

34. The sensor system recited in claim 32 wherein:

the database of images includes conventional fingerprint images.