Chemical imaging explosives (CHIMED) optical sensor

• US 7,692,776 B2
• Filed: 12/22/2006
• Issued: 04/06/2010
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Nelson, Matthew P., Treado, Patrick J.
• Primary Examiner(s): Geisel; Kara E
• Application Number:
  US11/645,132
• Publication Number:
  US 20090303471A1
• Time in Patent Office: 1,201 Days
• Field of Search: 356 72- 73, 356/301, 356317-318, 356/417
• US Class Current: 356/73
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 2001/024 passengers or luggage
• CPC Class Codes: G01N 2021/6417 Spectrofluorimetric devices
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 33/227 Explosives, e.g. combustive properties thereof detecting explosives in air G01N33/0057

Abstract

A system and method of detecting explosive compounds located on a sample. The sample is irradiated with animal-safe ultra-violet radiation generating a fluorescence data set. A fluorescence database is searched based on the fluorescence data set in order to identify a known fluorescence data set. If the searching of the fluorescence database identifies a known fluorescence data set, an area of interest in the sample is identified based on the known fluorescence data set identified in the fluorescence database searching. The area of interest is irradiated with substantially monochromatic radiation to generate a Raman data set of the area of interest. A Raman database is searched based on the Raman data set in order to identify a known Raman data set. An explosive compound in the area of interest is identified based on the known Raman data set identified by searching the Raman database.

Claims

1. A method comprising:

irradiating a sample with animal-safe ultra-violet radiation to thereby generate emitted photons;

obtaining a fluorescence data set based on the emitted photons;

first searching a fluorescence database in accordance with the fluorescence data set in order to identify a known fluorescence data set from said fluorescence database, wherein said fluorescence database contains a plurality of known fluorescence data sets, and wherein each known florescence data set is associated with one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material;

if said first searching identifies a known fluorescence data set from said fluorescence database, identifying an area of interest in the sample based on the known fluorescence data set identified in said first searching and irradiating the area of interest with substantially monochromatic radiation to thereby generate scattered photons from said area of interest;

obtaining a Raman data set based on said scattered photons;

second searching a Raman database in accordance with the Raman data set in order to identify a known Raman data set from said Raman database, wherein said Raman database contains a plurality of known Raman data sets, and wherein each known Raman data set is associated with a known explosive compound; and

identifying an explosive compound in the area of interest based on the known Raman data set identified by said second searching.

2. The method of claim 1, wherein said plurality of known fluorescence data sets includes one or more of the following:

a plurality of fluorescence spectra corresponding to one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material; and

a known explosive compound, a formulation additive of explosive material and a binder of explosive material.

3. The method of claim 1, wherein said plurality of known Raman data sets includes one or more of the following:

a plurality of Raman spectra corresponding to the known explosive compounds and a plurality of spatially accurate wavelength resolved Raman spectroscopic images corresponding to the known explosive compounds.

4. The method of claim 1, wherein said sample includes one or more of the following:

a human hand, a passport, a credit card, a driver'"'"'s license, a boarding pass, a human body part, a human clothing, a human-wearable item, and an airline ticket.

5. The method of claim 1, wherein said known explosive compound includes one or more of the following:

nitrocellulose, nitroglycerin, 1,3,5-trinitroperhydro-1,3,5-triazine (“

RDX”

), 1,3,5,7-tetranitroperhydro-1,3,5,7-tetrazocine (“

HMX”

), and 1,3-Dinitrato-2,2-bis (nitratomethyl)propane (“

PETN”

).

6. The method of claim 1, wherein said first searching comprises applying a similarity metric that generates a score.

7. The method of claim 6, wherein said similarity metric comprises one or more of the following:

a Euclidean distance metric, a spectral angle mapper metric, a spectral information divergence metric, a Mahalanobis distance metric and a spectral unmixing algorithm.

8. A system comprising:

an animal-safe ultra-violet irradiation source;

a substantially monochromatic irradiation source;

a spectroscopic device;

a fluorescence database having a plurality of known fluorescence data sets, wherein each known fluorescence data set is associated with one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material;

a Raman database having a plurality of known Raman sets, wherein each known Raman data set is associated with a known explosive compound;

a machine readable program code containing executable program instructions; and

substantially monochromatic irradiation source, and said spectroscopic device and configured to execute said machine readable program code so as to perform the following;

configure said animal-safe ultra-violet irradiation source to irradiate a sample with animal-safe ultra-violet radiation to thereby generate emitted photons;

configure said spectroscopic device to obtain a fluorescence data set based on said photons;

first search said fluorescence database in accordance with the fluorescence data set in order to identify a known fluorescence data set from said fluorescence database;

if said first search identifies a known fluorescence data set from said fluorescence database, identify an area of interest in the sample based on the know fluorescence data set identified in said first searching and configure said substantially monochromatic irradiation source to irradiate the area of interest with substantially monochromatic radiation to thereby generate scattered photons from said area of interest;

configure said spectroscopic device to obtain a Raman data set base don said scattered photons;

second search said Raman database in accordance with the Raman data set in order to identify a known Raman data set from said Raman database; and

identify an explosive compound in the area of interest based on the known Raman data set identified by said second searching.

9. The system of claim 8, wherein said plurality of known fluorescence data sets includes one or more of the following:

a plurality of fluorescence spectra corresponding to one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material; and

a plurality of spatially accurate wavelength resolved fluorescence spectroscopic images corresponding to one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material.

10. The system of claim 8, wherein said plurality of known Raman data sets includes one or more of the following:

a plurality of Raman spectra corresponding to the known explosive compounds and a plurality of spatially accurate wavelength resolved Raman spectroscopic images corresponding to the known explosive compounds.

11. The system of claim 8, wherein said sample includes one or more of the following:

a human hand, a passport, a credit card, a driver'"'"'s license, a boarding pass, a human body part, a human clothing, a human-wearable item, and an airline ticket.

12. The system of claim 8, wherein said known explosive compound includes one or more of the following:

nitrocellulose, nitroglycerin, 1,3,5-trinitroperhydro- 1,3,5-triazine (“

RDX”

), 1,3,5,7-tetranitroperhydro-1,3,5,7-tetrazocine (“

HMX”

), and 1,3-Dinitrato-2,2-bis (nitratomethyl) propane(“

PETN”

).

13. A system comprising:

means to irradiate a sample with animal-safe ultra-violet radiation to thereby generate emitted photons;

means to obtain a fluorescence data set based on said emitted photons;

a fluorescence database having a plurality of known fluorescence data sets, and wherein each known fluorescence data set is associated with one or more of the following;

a known explosive compound, a formulation additive of explosive material and a binder of explosive material;

means to first search said fluorescence database in accordance with the fluorescence data set in order to identify a known fluorescence data set from said database,

if said first search identifies a known fluorescence data set from said florescence database, means to identify an area of interest in the sample based on the known fluorescence data set identified in said first search and means to irradiate the area of interest with substantially monochromatic radiation to thereby generate scattered photons from said area of interest;

a Raman database having a plurality of known Raman data sets, and wherein each known Raman data set is associated with a known explosive compound

means to second search said Raman database in accordance with the Raman data set in order to identify a known Raman data set from said Raman database; and

means to identify an explosive compound in the area of interest based on the known Raman data set identified by said second search.

14. A storage medium containing machine readable program code, which, when executed by a processor, causes said processor to perform the following:

configure an animal-safe ultra-violet irradiation source to irradiate a sample with animal-safe ultra-violet radiation to thereby generate emitted photons;

configure a spectroscopic device to obtain a fluorescence data set based on said emitted photons;

first search a fluorescence database in accordance with the fluorescence data set in order to identify a known fluorescence data set from said fluorescence database;

if said first search identifies a known fluorescence data set from said fluorescence database, identify an area of interest in the sample based on the known fluorescence data set identified in said first search and configure a substantially monochromatic irradiation source to irradiate the area of interest with substantially monochromatic radiation to thereby generate scattered photons from the area of interest;

configure said spectroscopic device to obtain a Raman data set based on said scattered photons;

second search a Raman database in accordance with the Raman data set in order to identify a known Raman data set from said Raman database; and

identify an explosive compound in the area of interest based on the known Raman data set identified by said second search.

15. A method comprising:

obtaining a fluorescence emission signature of a sample, wherein said obtaining said fluorescence emission signature includes irradiating said sample with an animal-safe ultraviolet radiation;

determining whether a suspicious chemical substance is present in said sample and a location of said substance in said sample based on said fluorescence signature of the sample;

irradiating said location on said sample whh.a substantially monochromatic radiation to thereby generate scattered photons therefrom;

obtaining a Raman signature of said suspicious chemical substance based on said scattered photons; and

identifying said suspicious chemical substance based on a comparison of said Raman signature with a Raman database containing a plurality of Raman signatures associated with a corresponding plurality of known explosive materials.