Multipoint method for identifying hazardous agents

• US 7,538,869 B2
• Filed: 11/30/2004
• Issued: 05/26/2009
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Treado, Patrick J., Schweitzer, Robert, Demuth, Joseph E.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US11/000,683
• Publication Number:
  US 20090097020A1
• Time in Patent Office: 1,638 Days
• Field of Search: 356/301
• US Class Current: 356/301
• CPC Class Codes: G01N 2021/6417 Spectrofluorimetric devices
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04

Abstract

The invention relates to apparatus and methods for assessing occurrence of a hazardous agent in a sample by performing multipoint spectral analysis of the sample. Methods of employing Raman spectroscopy and other spectrophotometric methods are disclosed. Devices and systems suitable for performing such multipoint methods are also disclosed.

Claims

1. A method of assessing occurrence of a hazardous agent in a sample located in a field of view, the method comprising:

irradiating the sample with light; and

assessing Raman-shifted scattered radiation emanating from multiple points in the sample, the multiple points representing a portion of total points in the field of view wherein the Raman-shifted scattered radiation is characteristic of the presence or absence of the hazardous agent in the sample.

2. The method of claim 1, wherein Raman-shifted scattered radiation emanating from at least three points is assessed.

3. The method of claim 1, wherein Raman-shifted scattered radiation emanating from at least six points is assessed.

4. The method of claim 1, wherein Raman-shifted scattered radiation emanating from at least ten points is assessed.

5. The method of claim 1, wherein Raman-shifted scattered radiation emanating from at least fifty points is assessed.

6. The method of claim 1, further comprising thereafter assessing Raman-shifted scattered radiation emanating from multiple second points in a region of the sample corresponding to a point at which Raman-shifted scattered radiation characteristic of the hazardous agent was detected.

7. The method of claim 6, further comprising thereafter assessing Raman-shifted scattered radiation emanating from multiple third points in a region of the sample corresponding to a second point at which Raman-shifted scattered radiation characteristic of the hazardous agent was detected.

8. The method of claim 1, wherein at least three of the multiple points are colinear.

9. The method of claim 1, wherein at least three of the multiple points are colinear along a first line and wherein another at least three of the multiple points are colinear along a second line.

10. The method of claim 1, wherein at least four of the multiple points are radially equidistant from a central point.

11. The method of claim 1, wherein the field of view is in a microscopic field with the sample in the microscopic field, and the multiple points represent not more than 25% of the area of the microscopic field.

12. The method of claim 1, wherein the field of view is in a microscopic field with the sample in the microscopic field, and the multiple points represent not more than 5% of the area of the microscopic field.

13. The method of claim 1, wherein the field of view is in a microscopic field with the sample in the microscopic field, and the multiple points represent not more than 1% of the area of the microscopic field.

14. The method of claim 1, wherein the hazardous agent is a chemical agent.

15. The method of claim 1, wherein the hazardous agent is a biological toxin.

16. The method of claim 1, wherein the hazardous agent is a microorganism.

17. The method of claim 16, wherein the microorganism is a bacterium.

18. The method of claim 16, wherein the microorganism is a protozoan.

19. The method of claim 1, wherein the hazardous agent is a virus.

20. The method of claim 1, wherein the Raman-shifted scattered radiation is transmitted through a filter prior to assessing the Raman-shifted scattered radiation for the presence or absence of the hazardous agent.

21. The method of claim 20, wherein the filter is selected from the group consisting of a Fabry Perot angle tuned filter, an acousto-optic tunable filter, a liquid crystal tunable filter, a Lyot filter, an Evans split element liquid crystal tunable filter, a Solc Liquid crystal tunable filter, and a liquid crystal Fabry Perot tunable filter.

22. The method of claim 1, wherein the Raman-shifted scattered radiation is transmitted through an interferometer prior to assessing the Raman-shifted scattered radiation for the presence or absence of the hazardous agent.

23. The method of claim 22, wherein the interferometer is selected from the group consisting of a polarization-independent imaging interferometer, a Michelson interferometer, a Sagnac interferometer, a Twynam-Green interferometer, a Mach-Zehnder interferometer, and a tunable Fabry Perot interferometer.

24. The method of claim 1, wherein the Raman-shifted scattered radiation is transmitted through a dispersive spectrometer prior to assessing the Raman-shifted scattered radiation for the presence or absence of the hazardous agent.

25. The method of claim 1, wherein the Raman-shifted scattered radiation is collected using a device selected from the group consisting of a telescope, a macroscope, a microscope, an endoscope and a fiber optic array.

26. The method of claim 1, wherein, at least two of the multiple points have areas that vary by at least a factor or two.

27. The method of claim 1, comprising assessing occurrence of the hazardous agents at multiple portions of the sample by irradiating each multiple portion with light and assessing Raman-shifted scattered radiation emanating from multiple points in the multiple portions, wherein the multiple points have the same geometric relationship for each multiple portion.

28. The method of claim 1, wherein the geometric relationship of the multiple points is defined based on a spectroscopic feature of the sample.

29. The method of claim 28, wherein the spectroscopic feature is a feature of an optical image of the sample.

30. A method of identifying a hazardous agent in a sample, the method comprising:

irradiating the sample with light; and

assessing Raman-shifted scattered radiation emanating from multiple points in the sample, and

comparing the Raman-shifted scattered radiation with a known Raman scattering characteristic of the hazardous agent.

31. A method of identifying a hazardous agent in a sample located in a field of view, the method comprising:

irradiating multiple points in the sample with light; and

assessing Raman-shifted scattered radiation emanating from the multiple points in the sample, the multiple points representing a portion of total points in the field of view wherein the Raman-shifted scattered radiation is characteristic of the presence or absence of the hazardous agent in the sample.

32. A method of assessing viability of a hazardous agent in a sample, the method comprising:

irradiating the sample with light;

assessing Raman-shifted scattered radiation emanating from multiple points in the sample, and

comparing the Raman-shifted scattered radiation with a known Raman scattering characteristic of a viable or non-viable form of the hazardous agent.

33. A device for assessing occurrence of a hazardous agent in a sample, the device comprising:

a radiation source for irradiating the sample,

a Raman detector for simultaneously detecting Raman-shifted radiation scattered by multiple discrete portions of the sample, and

a controller operably linked to the Raman detector for restricting detection of Raman-shifted radiation to the multiple discrete portions of the sample.