Apparatus and method for detection of radiation

• US 7,391,028 B1
• Filed: 02/28/2006
• Issued: 06/24/2008
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Image Insight, Inc.
• Original Assignee: Advanced Fuel Research, Inc.
• Inventors: Rubenstein, Eric P.
• Primary Examiner(s): Hannaher; Constantine
• Application Number:
  US11/364,027
• Time in Patent Office: 847 Days
• Field of Search: 250/371, 250/370.08
• US Class Current: 250/370.08
• CPC Class Codes: G01T 1/11 Thermo-luminescent dosimeters thermo-luminescent compositions C09K11/00
• CPC Class Codes: G01T 1/366 with semi-conductor detectors see provisionally also G01T1/36
• CPC Class Codes: G01T 7/00 Details of radiation-measuring instruments

Abstract

Digital images or the charge from pixels in light sensitive semiconductor based imagers may be used to detect gamma rays and energetic particles emitted by radioactive materials. Methods may be used to identify pixel-scale artifacts introduced into digital images and video images by high energy gamma rays. Statistical tests and other comparisons on the artifacts in the images or pixels may be used to prevent false-positive detection of gamma rays. The sensitivity of the system may be used to detect radiological material at distances in excess of 50 meters. Advanced processing techniques allow for gradient searches to more accurately determine the source'"'"'s location, while other acts may be used to identify the specific isotope. Coordination of different imagers and network alerts permit the system to separate non-radioactive objects from radioactive objects.

Claims

1. A system for detecting high energy particles comprising:

at least one pixilated imager having a light sensitive pixilated chip comprising pixels wherein the at least one light sensitive pixilated imager is configured to produce a digital still image, a digital video image or a combination thereof positioned to allow high energy particles from an ambient environment to strike the light sensitive pixilated chip;

at least one processor in communication with the at least one pixilated imager, said at least one processor being capable of detecting one or more pixels that have interacted with at least one high energy particle and generating an output signal in response to the one or more pixels that have interacted with at least one high energy particle in real time.

2. The system of claim 1, wherein the at least one pixilated imager is selected from pixilated photon detectors, charge coupled device (CCD) imagers, complementary metal oxide semiconductor (CMOS) imagers, and silicon-germanium, germanium, silicon-on-sapphire, indium-gallium-arsenide, cadmium-mercury-telluride, or gallium-arsenide substrate containing imagers, and combinations thereof.

3. The system of claim 1, wherein the at least one high energy particle detected by the processor comprises the product of a source of high energy particles wherein the source of high energy particles comprises a source of nuclear decay of radioactive material.

4. The system of claim 3, wherein the source of the high energy particle is selected from ambient radiation, radiation from natural sources, radioactive materials, nuclear devices, dirty-bombs and nuclear weapons either before or after detonation, and combinations thereof.

5. The system of claim 3, wherein the source is shielded.

6. The system of claim 1, wherein each of the one or more pixels produce a signal when the at least one high energy particle strikes the one or more pixels.

7. The system of claim 6, wherein the signal is proportional to the energy of high energy particles that strike the pixel.

8. The system of claim 6, wherein the signal is stronger than that of background radiation.

9. The system of claim 1, further comprising an output device, wherein the output device displays one or more dots on an image acquired from the at least one pixilated imager, wherein said dots correspond with each of the one or more high energy particles detected.

10. The system of claim 1, wherein the at least one processor is capable of identifying a source of the at:

least one high energy particle.

11. The system of claim 1, wherein the at least one pixilated imager pans, tilts, or a combination thereof, wherein panning comprises rotating about a vertical axis and wherein tilting comprises rotating about a horizontal axis.

12. The system of claim 1, wherein the at least one pixilated imager provides images.

13. The system of claim 1, wherein the at least one pixilated imager is selected from security cameras, traffic cameras, transit cameras, CCD, CMOS cameras, mobile law enforcement cameras, cell phone cameras, thermal infrared cameras and combinations thereof.

14. The system of claim 1, wherein the system comprises a plurality of pixilated imagers and wherein said plurality of pixilated imagers are interconnected.

15. The system of claim 1, wherein the at least one pixilated imager is positioned to monitor objects, wherein said objects are selected from animate and inanimate objects, motor vehicles, airplanes, trains, subway cars, people, animals, buildings, vegetation, luggage, boxes, bags, handbags, briefcases, mail, and combinations thereof.

16. The system of claim 15, wherein the at least one pixilated imager is position to monitor motion or mixing of the objects.

17. The system of claim 1, wherein the processor is selected from a computer, a video, image processor and combinations thereof.

18. The system of claim 1, further comprising an output device selected from an alarm system;

a photographic or video image;

an image on a monitor;

an audible sound;

a telephone call, a radio transmission and combinations thereof.

19. The system of claim 1, further comprising an output device in communication with the at least one processor, said output device being capable of reporting the detection of the at least one high energy particle.

20. The system of claim 1, wherein the output signal is transmitted via a secure communication.

21. The system of claim 1, wherein a source of the at least one high energy particle is outside a field of view of the at least one pixilated imager.

22. The system of claim 1, further comprising a processor module configured to determine a number of pixels that have interacted with the at least one high energy particle and an energy of the at least one high energy particle, a type of a source of the at least one high energy particle or an amount of a source of the at least one high energy particle.

23. The system of claim 1, wherein the at least one pixilated imager is completely covered, partially covered or reversibly covered.

24. A method for detecting high energy particles comprising:

collecting data from one or more pixilated image detectors configured to produce a digital still image, a digital video image, or a combination thereof positioned to allow high energy particles from an ambient environment to strike the light sensitive pixilated chip, each pixilated imager having a light sensitive pixilated chip comprising pixels for creating a digital still image, a digital video image or a combination thereof;

identifying from the collected data at least one pixel that has interacted with at least one high energy particle in real time; and

detecting a source of the at least one high energy particle.

25. The method of claim 24, wherein the one or more pixilated imagers are selected from a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS) device, and silicon-germanium, germanium, silicon-on-sapphire, indium-gallium-arsenide, cadmium-mercury-telluride, or gallium-arsenide substrate devices, and combinations thereof.

26. The method of claim 24, wherein the source of the at least one high energy particle comprises a radioactive material, radioisotope and combinations thereof.

27. The method of claim 24, further comprising quantifying a change in charge, voltage or a combination thereof produced when the at least one pixel interacts with the at least one high energy particle.

28. The method of claim 27, further comprising determining a number of pixels that have interacted with at least one high energy particle and an energy of the at least one high energy particle;

a type of the source, or an amount of the source based on the quantified change in charge.

29. The method of claim 24, further comprising acquiring one or more digital still images, one or more digital video images or a combination thereof from the one or more pixilated image detectors.

30. The method of claim 29, further comprising visually determining a position of the source based on the image acquired.

31. The method of claim 24, further comprising checking for false positive detection of a high energy particle.

32. The method of claim 24, further comprising generating an alert when the at least one high energy particle is detected.

33. The method of claim 32, wherein the alert is selected from an audible alert, a visual alert or a combination thereof.

34. The method of claim 24, further comprising tracking the source of the at least one high energy particle, wherein tracking comprises continuously moving at least one of the one or more pixilated image detectors such that at least one high energy particle interacts with at least one pixel of the at least one continuously moving pixilated image detector.

35. The method of claim 34, wherein tracking further comprises determining a maximum flux, wherein the maximum flux is a position where at least one pixel of the at least one continuously moving pixilated image detector has a maximum probability of interacting with at least one high energy particle.

36. The method of claim 35, wherein the maximum flux occurs when the light sensitive pixilated chip is perpendicular to the source of the at least one high energy particle.

37. The method of claim 35, further comprising performing a gradient search wherein the gradient search comprises adjusting the at least one continuously moving pixilated imager detector until maximum flux is achieved.

38. The method of claim 35, wherein tracking further comprises:

coordinating two or more pixilated image detectors;

moving each of the two or more pixilated image detectors independently;

concurrently achieving maximum flux for each of the two or more pixilated image detectors;

triangulating a position of the source of the at least one high energy particle using the position of each of two or more pixilated image detectors during the maximum flux; and

identifying an object comprising the source on the one or more digital still images, one or more digital video images or combination thereof wherein the object corresponds with at least one area on each of the one or more digital still images, one or more digital video images or combination thereof.

39. The method of claim 38, further comprising displaying at least one bright spot on the one or more digital still images, one or more digital video images or a combination thereof corresponding to the position of the source.

40. The method of claim 38, further comprising displaying the at least one area on the one or more digital still images, one or more digital video images or a combination thereof to determine a position of the source.

41. The method of claim 38, wherein the at least one area appears on one or more consecutive digital still images, one or more consecutive digital video images or a combination thereof.

42. The method of claim 38, further comprising monitoring a position of the at least one area on each of one or more consecutive digital still images, one or more consecutive digital video images or a combination to track movement of the source.

43. The method of claim 24, further comprising:

coordinating two or more pixilated image detectors;

moving;

each of the two or more pixilated image detectors independently;

obtaining one or more digital still images, one or more digital video images or a combination thereof from each of the two or more pixilated image detectors, wherein each of the one or more digital still images, one or more digital video images or a combination thereof comprises at least one area;

triangulating a position of the source of the at least one high energy particle using the position of each of two or more pixilated image detectors during the maximum flux; and

identifying at least a portion of the at least one area, wherein each of one or more digital still images, one or more digital video images or a combination thereof intersect.

44. The method of claim 24, further comprising determining a brightness of the at least one pixel.

45. The method of claim 44, further comprising utilizing the brightness to determine at least one of:

a number of pixels that have interacted with the at least, one high energy particle;

an energy of the at least one high energy particle;

a type of the source;

or

an amount of the source.

46. The method of claim 24, wherein the one or more pixilated imagers are completely covered, partially covered or reversibly covered.

47. A system for detecting high energy particles comprising:

one or more pixilated image detectors each having a light sensitive pixilated chip wherein the one or more light sensitive pixilated image detectors are configured to produce a digital still image, a digital video image or a combination thereof positioned to allow high energy particles from an ambient environment to strike the light sensitive pixilated chip;

one or more processors; and

a processor readable storage medium containing one or more instructions for detecting a high energy particle including instructions for;

scanning image data from the one or more pixilated image detectors,

identifying one or more high count-rate pixels,

quantifying an output for the one or more high count-rate pixels,

identifying one or more high count-rate pixels that have reached or exceeded a user defined threshold, and

generating a signal in response to the one or more high count-rate pixels that has reached or exceeded the user defined threshold.

48. The system of claim 47, wherein the processor readable storage medium further contains one or more instructions for converting image data from the one or more pixilated image detectors into a format suitable for scanning.

49. The system of claim 47, wherein the one or more instructions for quantifying an output for the one or more high count-rate pixels comprise one or more instructions for determining a brightness for the one or more high count-rate pixels.

50. The system of claim 47, wherein the one or more instructions for identifying one or more high count-rate pixels that have reached or exceeded a user defined threshold output includes determining if the output of the one or more high count-rate pixels is one or more of:

greater than zero,

greater than an output of one or more neighboring pixels,

greater than an average of one or more neighboring pixels by a user defined threshold,

greater than an average of one or more neighboring pixels by a user defined threshold value times the average of the one or more neighboring pixels, and

greater than an average of one or more neighboring pixels by a user defined threshold value times the square root of the average of the one or more neighboring pixels.

51. The system of claim 47, wherein the one or more instructions for identifying one or more high count-rate pixels that have reached or exceeded a user defined threshold output include quantifying a number of times a high count-rate pixel has reached or exceeded user defined threshold output over a specified parameter, wherein the specified parameter comprises a number of frames, a user defined time period or a combination thereof.

52. The system of claim 47, wherein the one or more instructions for quantifying an output of one or more high count-rate pixels comprise one or more instructions for determining an energy spectrum for the output of the one or more high count-rate pixels.

53. The system of claim 52, wherein the one or more instructions for determining an energy spectrum for the output of the one or more high count-rate pixels comprises one or more instructions for:

comparing the energy spectrum of the one or more high count-rate pixels with a plurality of energy spectra in a library of energy spectra for known radioisotopes,

matching the energy spectrum of the one or more high count-rate pixels with an energy spectrum for a known radioisotope, and

identifying a type of radioisotope that comprises a source of high energy particles that have interacted with the one or more high count-rate pixels to produce the energy spectrum of the one or more high count-rate pixels.

54. The system of claim 52, wherein the one or more instructions for determining an energy spectrum for the output of the one or more high count-rate pixels comprises one or more instructions for:

comparing the energy spectrum of the one or more high count-rate pixels with a plurality of energy spectra in a library of energy spectra for known radioisotopes,

matching the energy spectrum of the one or more high count-rate pixels with an energy spectrum for a known radioisotope,

identifying one or more high count-rate pixels for which no match to an energy spectrum of a known radioisotope is found, and

eliminating one or more high count-rate pixels for which no match to an energy spectrum of a known radioisotope is found.

55. The system of claim 47, wherein the processor readable storage medium further contains one or more instructions for integrating an output from multiple image detectors.

56. The system of claim 55, wherein the one or more instructions for integrating an output from multiple image detectors comprises one or more instructions for:

gathering image data from the multiple image detectors, and

transmitting the image data from the multiple image detectors to a destination for action or storage.

57. The system of claim 55, wherein the one or more instructions for integrating an output from multiple image detectors comprise one or more instructions for comparing images from the multiple detectors.

58. The system of claim 47, wherein the one or more instructions for generating the signal comprise one or more instructions for generating an audible signal.

59. The system of claim 47, wherein the one or more instructions for generating the signal comprise one or more instructions for generating a visual signal.

60. The system of claim 47, wherein the one or more programming instructions for generating the signal comprise one or more programming instructions for generating one or more images.

61. The system of claim 47, wherein the processor readable storage medium further contains one or more instructions for repeating the instructions.

62. The system of claim 47, wherein the one or more pixilated imagers are completely covered, partially covered or reversibly covered.