Sensor comprising multi-wavelength LEDs

• US 20060014237A1
• Filed: 07/15/2004
• Published: 01/19/2006
• Est. Priority Date: 07/15/2004
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Maurer, Scott M., Brewer, Ryan C., Kofler, Kevin J., Jackson, Larry D.
• Granted Patent: US 7,173,702 B2
• Time in Patent Office: Days
• US Class Current: 435/34
• CPC Class Codes: C12M 41/36 of biomass, e.g. colony counters or by turbidity measurements electrooptical investigation of individual particles G01N15/14, flow cytometers G01N15/1404
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 15/075 by optical means
• CPC Class Codes: G01N 2015/0046 in gas, e.g. smoke
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution

Abstract

The illustrative embodiment of the present invention is a system and a method for the detection and identification of biological agents. The system incorporates elements that enable it to obtain an air sample, extract particulates from the air sample onto a stationary-phase collection media, expose the particulates to electromagnetic radiation, and monitor for fluorescent emissions. In some embodiments, particulates are exposed to electromagnetic radiation using a plurality of LEDs, wherein some of the LEDs emit electromagnetic radiation at relatively shorter wavelengths and some other of the LEDs emit electromagnetic radiation at relatively longer wavelengths.

Claims

1. An apparatus comprising:

a stationary phase collection media for collecting a sample;

a first plurality of light-emitting diodes (LEDs) for intermittently exposing said sample to electromagnetic radiation having a first peak wavelength;

a second plurality of light-emitting diodes LEDs for intermittently exposing said sample to electromagnetic radiation having a second peak wavelength that is different than said first peak wavelength;

circuitry for controlling operation of said first plurality of LEDs and said second plurality of LEDs to provide the intermittent exposure; and

a plurality of photodetectors for detecting fluorescent emissions from said sample resulting from the exposure to electromagnetic radiation.

2. The apparatus of claim 1 wherein said first plurality of LEDs emit radiation at a peak wavelength that is less than 300 nanometers.

3. The apparatus of claim 1 wherein said second plurality of LEDs emit radiation at a peak wavelength that is greater than 300 nanometers.

4. The apparatus of claim 2 wherein said second plurality of LEDs emit radiation at a peak wavelength that is greater than 300 nanometers.

5. The apparatus of claim 2 wherein said second plurality of LEDs emit radiation at a peak wavelength that is greater than 350 nanometers.

6. The apparatus of claim 2 wherein said second plurality of LEDs emit radiation at a peak wavelength that is greater than 400 nanometers.

7. The apparatus of claim 1 wherein said first plurality of LEDs emit radiation at a peak wavelength that is less than 350 nanometers.

8. The apparatus of claim 7 wherein said second plurality of LEDs emit radiation at a peak wavelength that is greater than 380 nanometers.

9. The apparatus of claim 7 wherein said first plurality of LEDs emit radiation having a peak wavelength that is less than 400 nanometers and wherein said second plurality of LEDs emit radiation having a peak wavelength this is greater than 400 nanometers.

10. The apparatus of claim 1 wherein:

said first plurality of LEDs emit radiation having a peak wavelength that is 300 nanometers or less;

said second plurality of LEDs emit radiation having a peak wavelength that is greater than 300 nanometers and less than 350 nanometers; and

further comprising

at least one LED that emits radiation having a peak wavelength of 350 nanometers or more.

11. The apparatus of claim 1 wherein said first plurality of LEDs illuminate said sample at a different time than said second plurality of LEDs.

13. The method of claim 11 wherein monitoring comprises determining signal strength of first fluorescent emissions from particulates retained in said collection media when exposed to electromagnetic radiation having said first peak wavelength.

12. A method comprising:

obtaining a sample of air;

passing said sample through collection media, wherein said collection media is capable of retaining at least some particulates that are contained in said sample;

intermittently exposing said collection media with electromagnetic radiation having a first peak wavelength, wherein the exposure occurs at a first time;

intermittently exposing said collection media with electromagnetic radiation having a second peak wavelength, wherein the exposure occurs at a second time, and wherein the second time is different from the first time; and

monitoring said collection media for fluorescent emissions.

14. The method of claim 12 wherein monitoring comprises triggering an alert when the determined signal strength of fluorescent emissions exceeds a first value.

15. The method of claim 12 comprising comparing the determined signal strength for said first fluorescent emissions to fluorescence emission data, for each of a plurality of biological agents, which is contained in a database.

16. The method of claim 12 wherein monitoring comprises determining signal strength of second fluorescent emissions from particulates retained in said collection media when exposed to electromagnetic radiation having said second peak wavelength.

17. The method of claim 14 wherein monitoring comprises:

determining a signal strength of second fluorescent emissions from particulates retained in said collection media when exposed to electromagnetic radiation having said second peak wavelength; and

comparing the determined signal strength of said second fluorescent emissions to said fluorescence emission data.

18. The method of claim 16 comprising determining an identity of a biological agent in the retained particulates by matching said signal strength for said first fluorescent emissions to fluorescence emission data in said database.

19. The method of claim 17 comprising determining an identity of a biological agent in the retained particulates by matching said signal strengths for said first fluorescent emissions and said signal strengths for said second fluorescent emissions to said fluorescence emission data in said database.