Apparatus and method for identification of individuals by near-infrared spectrum

• US 6,628,809 B1
• Filed: 10/08/1999
• Issued: 09/30/2003
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: HID Global Corporation (Assa Abloy AB)
• Original Assignee: Lumidigm Incorporated (Assa Abloy AB)
• Inventors: Miller, William A., Ge, Nanxiang, Rowe, Robert K., Robinson, Mark Ries
• Primary Examiner(s): WERNER, BRIAN P
• Application Number:
  US09/415,594
• Time in Patent Office: 1,453 Days
• Field of Search: 382/115, 382/124, 382/125, 382/126, 382/127, 73/73, 250/559.44, 250/316.1, 250/339.07, 250/339.1, 250/341.8, 250/339.02, 340/5.52, 340/5.82, 356/51, 356/303, 356/445, 356/939, 356/71, 902/3, 707/6, 713/186, 702/19, 702/76
• US Class Current: 382/115
• 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 5/117 Identification of persons methods or arrangements for recognising patterns, e.g. fingerprints, G06F18/00, G06V40/00; identification of persons by analysing their voice or speech G10L17/00
• CPC Class Codes: A61B 5/7267 involving training the classification device
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: G06V 40/12 Fingerprints or palmprints
• CPC Class Codes: G06V 40/40 Spoof detection, e.g. liveness detection
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

Methods and apparatus for non-invasively verifying human identities using near-infrared spectroscopy. Near-infrared tissue spectra can be obtained by projecting near-infrared radiation into skin on the underside of human forearms and capturing the light reflected back and out through the tissue. The tissue spectrum collected preferably includes primarily diffuse reflected light reflected from the inner dermis. Multiple tissue spectra and identities can be collected from individuals for whom identity verification may later be desired. The tissue spectra for each individual can be analyzed on a computer, and the spectra for each individual clustered or classified together using tools such as linear discriminant analysis. A target individual seeking identity verification can submit both a purported identity and a near-infrared tissue spectrum for analysis through near-infrared spectroscopy of the forearm. Similarity between the target spectrum and the multiple spectra for the purported identity in the spectral database is determined and identify verified or not verified based on the degree of similarity.

Claims

1. A method for verifying the purported identity of a target individual utilizing a number of authorization tissue spectral data from verified individuals having known identities, said spectral data having a plurality of measurement wavelengths, comprising the steps of:

obtaining target tissue spectral data from subepidermal tissue of said target individual by applying a plurality of optical wavelengths to the subepidermal tissue and measuring a plurality of wavelengths emanating from the tissue; and

positively verifying said target individual'"'"'s purported identity by confirming consistency of a difference calculated between the target tissue spectral data and authorization tissue spectral data with a database having a plurality of intra-patient difference spectra for the target individual.

2. The method for verifying the purported identity of a target individual as recited in claim 1, further evaluating the difference calculated wherein said evaluation is done by a model that identifies between patients'"'"' differences.

3. The method for verifying the purported identity of a target individual as recited in claim 1, wherein said differences are processed through a model to determine the significance of identified differences.

4. The method for verifying the purported identity of a target individual as recited in claim 1, wherein said number of verified individuals is equal to one.

5. The method for verifying the purported identity of a target individual as recited in claim 1, wherein said number of verified individuals is greater than one.

6. The method for verifying the purported identity of a target individual as recited in claim 1, further comprising obtaining a number of authorization tissue spectra from an individual, said number of authorization tissue spectra being greater than two.

7. The method for verifying the purported identity of a target individual as recited in claim 1, wherein said target spectrum is added to said authorization spectra after said verification.

8. The method as recited in claim 1, wherein said number of measurement wavelengths is greater than four, further comprising calculating an inter-person spectral distance between said authorized spectra of said verified individuals at said wavelengths, wherein said wavelengths are selected at least in part to maximize said inter-person spectral differences.

9. The method as recited in claim 8, wherein said number of authorization tissue spectra is greater than four, further comprising calculating an intra-person spectral distance between said authorization spectra for an individual at said wavelengths, wherein said wavelengths are selected at least in part to minimize said intra-person spectral differences.

10. The method as recited in claim 1, wherein said tissue spectra include near-infrared wavelengths.

11. The method as recited in claim 10, wherein said tissue spectra includes a substantial spectral contribution from subcutaneous blood.

12. The method recited in claim 1 wherein applying the plurality of optical wavelengths comprises applying a spectral band of the optical wavelengths.

13. A system for verifying the purported identity of a target individual comprising:

an authorized database including a plurality of intra-patient difference near-infrared tissue spectra for each of a plurality of authorized persons;

means for obtaining a near-infrared tissue spectrum and purported identity from said target individual by applying a plurality of optical wavelengths to subepidermal tissue of the target individual and measuring a plurality of wavelengths emanating from the tissue;

means for discriminating between said target individual near-infrared spectrum and said authorized persons near-infrared spectra by confirming consistency of a difference calculated between the target individual near-infrared spectrum and an authorization near-infrared tissue spectrum with the intra-patient difference near-infrared tissue spectra of the authorized database; and

means for indicating if said target individual purported identity is correct.

14. The system as recited in claim 13, wherein said discriminating means utilizes said target purported identity.

15. The system as recited in claim 13, wherein said means for discrimination includes means for selecting a plurality of said wavelengths, such that spectral differences between said spectra of said authorized persons is maximized.

16. A system for verifying the purported identify of a target individual comprising:

a computer including an input device and an output device;

a database including a plurality of intra-patient difference near-infrared tissue spectra for each of a plurality of authorized persons;

means for obtaining a near-infrared tissue spectrum from said target individual, including a near-infrared radiation source for projecting a plurality of near-infrared optical wavelengths subcutaneously and a near-infrared spectrometer for measuring subcutaneous near-infrared intensity over a plurality of wavelengths; and

a program running in said computer for discriminating between said target individual near-infrared spectrum and said authorized persons near-infrared spectra by confirming consistency of a difference calculated between the target individual near-infrared tissue spectrum and an authorization near-infrared tissue spectrum with the intra-patient difference near-infrared tissue spectra of the database.

17. The system of claim 16, wherein said means for obtaining a near-infrared tissue spectra includes an input element and an output element coupled to said tissue via an index-matching medium.

18. The system of claim 17, wherein said index-matching medium comprises a chlorofluorocarbon polymer.

19. The system of claim 18, wherein said polymer includes chlorotrifluoroethylene.

20. The system of claim 17, wherein said index-matching medium has a refractive index between 1.30 and 1.45.

21. A system for verifying the purported identity of a target individual comprising:

an authorized database including a plurality of intra-patient difference near-infrared tissue spectra for each of a plurality of authorized persons;

an optical source adapted to apply a plurality of optical wavelengths to subepidermal tissue of the target individual;

a spectrometer adapted to obtain a near-infrared tissue spectrum from the target individual by measuring a plurality of wavelengths emanating from the tissue;

a comparator adapted to discriminate between the target individual near-infrared spectrum and the authorized persons near-infrared spectra by confirming consistency of a difference calculated between the target individual near-infrared spectrum and an authorization near-infrared tissue spectrum with the intra-patient difference near-infrared tissue spectra of the authorized database; and

an indicator adapted to indicate if a purported identity of the target individual is correct.

22. The system of claim 21 wherein the optical source and spectrometer are coupled to the tissue via an index-matching medium.

23. The system of claim 22, wherein the index matching medium comprises a chlorofluorocarbon polymer.

24. The system of claim 23, wherein the polymer includes chlorotrifluoroethylene.