Apparatus and method for identification of individuals by near-infrared spectrum
View Patent ↗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.
1. A method for identifying an individual, the method comprising:
applying an incident optical spectral distribution to subepidermal tissue of the individual;
measuring a response optical spectral distribution emanating from the subepidermal tissue;
deriving a difference optical spectral distribution by performing a mathematical operation on the response optical spectral distribution and a reference optical spectral distribution; and
determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution, wherein determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution comprises analyzing the difference optical spectral distribution with a database having a plurality of difference spectra.
2. The method recited in claim 1 wherein the deriving and determining steps are performed for a plurality of reference optical spectral distributions, each of which is associated with a different person, whereby a determination is made whether the individual is one of a set of persons.
3. The method recited in claim 1 wherein the deriving and determining steps are performed for a single reference optical spectral distribution associated with a purported identity of the individual, whereby a determination is made whether the individual has the purported identity.
4. The method recited in claim 1 wherein the mathematical operation comprises calculation of a difference between the response optical spectral distribution and the reference optical spectral distribution.
5. The method recited in claim 1 wherein the mathematical operation comprises calculation of a ratio between the response optical spectral distribution and the reference optical spectral distribution.
6. The method recited in claim 1 wherein the database has a plurality of intra-person difference spectra for a person associated with the reference optical spectral distribution.
7. The method recited in claim 1 wherein the database has a plurality of inter-person difference spectra.
8. The method recited in claim 1 wherein a plurality of intra-person and inter-person difference spectra.
9. The method recited in claim 1 wherein determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution comprises performing a discriminate analysis to compare underlying spectral shapes of the difference optical spectral distribution with the reference optical spectral distribution.
10. A system for identifying an individual, the system comprising:
an optical source adapted to apply an incident optical spectral distribution to subepidermal tissue of the individual;
a spectrometer adapted to measure a response optical spectral distribution emanating from the subepidermal tissue; and
a computational device in communication with the spectrometer and having a program with computer-readable instructions for:
deriving a difference optical spectral distribution by performing a mathematical operation on the response optical spectral distribution and a reference optical spectral distribution; and
determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution, wherein the instructions for determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution comprise instructions for analyzing the difference optical spectral distribution with a database having a plurality of intra-person difference spectra.
11. The system recited in claim 10 wherein the instructions for deriving and determining are executed for a plurality of reference optical spectral distributions, each of which is associated with a different person, whereby a determination is made whether the individual is one of a set of persons.
12. The system recited in claim 10 wherein the instructions for deriving and determining are executed for a single reference optical spectral distribution associated with a purported identity of the individual, whereby a determination is made whether the individual has the purported identity.
13. The system recited in claim 10 wherein the mathematical operation comprises calculation of a difference between the response optical spectral distribution and the reference optical spectral distribution.
14. The system recited in claim 10 wherein the mathematical operation comprises calculation of a ratio between the response optical spectral distribution and the reference optical spectral distribution.
15. The system recited in claim 10 wherein the database has a plurality of intra-person difference spectra for a person associated with the reference optical spectral distribution.
16. The system recited in claim 10 wherein the database has a plurality of inter-person difference spectra.
17. The system recited in claim 10 wherein the database has a plurality of intra-person and inter-person difference spectra.
18. The system recited in claim 10 wherein the instructions for determining whether characteristics of the difference optical spectral distribution are consistent with the individual being a person associated with the reference optical spectral distribution comprise instructions for performing a discriminate analysis to compare underlying spectral shapes of the difference optical spectral distribution with the reference optical spectral distribution.