Analytical instruments using a pseudorandom array of sources, such as a micro-machined mass spectrometer or monochromator

• US 7,339,521 B2
• Filed: 02/20/2003
• Issued: 03/04/2008
• Est. Priority Date: 02/20/2002
• Status: Expired due to Term

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Hess, Henry, Scheidemann, Adi
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Miller; Rose M
• Application Number:
  US10/502,842
• Publication Number:
  US 20050119868A1
• Time in Patent Office: 1,839 Days
• Field of Search: 342/372
• US Class Current: 342/379
• CPC Class Codes: H01J 49/107 Arrangements for using several ion sources

Abstract

Novel methods and structures are disclosed herein which employ pseudorandom sequences to spatially arrange multiple sources in a pseudorandom source array. The pseudorandom source array can replace the single source in analytical instruments relying on spatial separation of the sample or the probe particles/waves emitted by the sources. The large number of sources in this pseudorandom source array enhances the signal on a position sensitive detector. A mathematical deconvolution process retrieves a spectrum with improved signal-to-noise ratio from the detector signal.

Claims

1. An analytical device comprising:

a source assembly comprising a plurality of sources, the sources spatially arrayed pseudo-randomly in at least a first dimension;

a detector assembly spaced from the source assembly, the detector assembly comprising a number of sensors sensitive to an output of the plurality of sources, and

a dispersion element positioned in a path between at least one of the plurality of sources and at least one of the sensors to disperse the output of at least one of the plurality of sources,

wherein the dispersion element comprises a magnetic assembly positioned to create a magnetic field in the path between at least one of the plurality of sources and at least one of the sensors to disperse the output of at least one of the plurality of sources.

2. The analytical system claim 1 in the form of a mass spectrometer wherein each of the plurality of sources is an ion emitter, and each sensor of the detector assembly is a Faraday cup.

3. An analytical system comprising:

a source assembly comprising a plurality of sources, the sources spatially arrayed pseudo-randomly in at least a first dimension;

a detector assembly spaced from the source assembly, the detector assembly comprising a number of sensors sensitive to an output of the plurality of sources; and

a computer coupled to the detector assembly to receive detector signals therefrom corresponding to the output of the plurality of sources sensed by the number of sensors, the computer programmed to process the detector signals via a deconvolution algorithm,

wherein the computer is programmed to process the detector signals via a deconvolution algorithm by;

constructing a detector signal matrix from the detector signals;

multiplying the detector signal matrix by a deconvolution matrix to produce a spectrum matrix; and

truncating the spectrum matrix after the first L elements to produce a pseudorandom spectrum.

4. The analytical system of claim 3 in the form of a monochromator wherein the plurality of sources is an array of entrance slits, the dispersing element is a grating, and the detector assembly is an array of charge coupled devices.

5. The analytical device of claim 3 in the form of a computer aided tomography scanner wherein the plurality of sources are X-ray emitting sources, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are X-ray detectors.

6. The analytical system of claim 3 in the form of a magnetic resonance imager wherein the plurality of sources are radio frequency emitters, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are magnetic coils.

7. The analytical system of claim 3 in the form of a ultrasound machine wherein the plurality of sources are speakers, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are ultrasonic transducers.

8. The analytical system of claim 3 wherein the number of sensors in the detector assembly is equal to N+L−

1 where N is the number of sources and L is the length of a spectrum.

9. The analytical system of claim 3 in the form of a mass spectrometer wherein each of the plurality of sources is an ion emitter and each sensor of the detector assembly is a Faraday cup.

10. An analytical system comprising:

a source assembly comprising a plurality of sources, the sources spatially arrayed pseudo-randomly in at least a first dimension;

a detector assembly spaced from the source assembly, the detector assembly comprising a number of sensors sensitive to an output of the plurality of sources; and

a computer coupled to the detector assembly to receive detector signals therefrom corresponding to the output of the plurality of sources sensed by the number of sensors, the computer programmed to process the detector signals via a deconvolution algorithm,

wherein the number of sensors in the detector assembly is equal to N+L−

1 where N is the number of sources and L is the length of a spectrum.

11. The analytical system of claim 10 wherein the computer is programmed to process the detector signals via a deconvolution algorithm by:

constructing a detector signal matrix from the detector signals;

multiplying the detector signal matrix by a deconvolution matrix to produce a spectrum matrix; and

truncating the spectrum matrix after the first L elements to produce a pseudorandom spectrum.

12. The analytical system of claim 10 in the form of a mass spectrometer wherein each of the plurality of sources is an ion emitter and each sensor of the detector assembly is a Faraday cup.

13. The analytical system of claim 10 in the form of a monochromator wherein the plurality of sources is an array of entrance slits, the dispersing element is a grating, and the detector assembly is an array of charge coupled devices.

14. The analytical device of claim 10 in the form of a computer aided tomography scanner wherein the plurality of sources are X-ray emitting sources, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are X-ray detectors.

15. The analytical system of claim 10 in the form of a magnetic resonance imager wherein the plurality of sources are radio frequency emitters, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are magnetic coils.

16. The analytical system of claim 10 in the form of a ultrasound machine wherein the plurality of sources are speakers, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are ultrasonic transducers.

17. An analytical system comprising:

a source assembly comprising a plurality of sources spatially arrayed in at least a first dimension;

a detector assembly spaced from the source assembly, the detector assembly comprising a number of sensors sensitive to an output of the plurality of sources; and

a computer coupled to control activation of the sources in a spatially pseudo-random order in at least a first dimension,

wherein the computer is coupled to control activation of the sources in a spatially pseudo-random order in at least a first dimension by;

activating successive ones of the plurality of sources with a respective pseudo-random number of unactivated sources between each respective pair of the activated sources in the array.

18. The analytical system of claim 17 wherein the plurality of sources are spatially arrayed uniformly in the first dimension.

19. The analytical system of claim 17 in the form of a mass spectrometer wherein each of the plurality of sources is an ion emitter and each sensor of the detector assembly is a Faraday cup.

20. The analytical system of claim 17 in the form of a monochromator wherein the plurality of sources is an array of entrance slits, the dispersing element is a grating, and the detector assembly is an array of charge coupled devices.

21. The analytical device of claim 17 in the form of a computer aided tomography scanner wherein the plurality of sources are X-ray emitting sources, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are X-ray detectors.

22. The analytical system of claim 17 in the form of a magnetic resonance imager wherein the plurality of sources are radio frequency emitters, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are magnetic coils.

23. The analytical system of claim 17 in the in the form of an ultrasound machine wherein the plurality of sources are speakers, the dispersing element is a sample being analyzed, and the sensors of the detector assembly are ultrasonic transducers.

24. An analytical device, comprising

means for activating a number of pseudo-randomly arrayed ion sources to produce output;

a detector coupled to detect output produced by the pseudo-randomly arrayed ion sources and to produce detector signals corresponding to the detected output; and

means for deconvoluting the detector signals to produce a pseudorandom spectrum.

25. The device of claim 24 wherein the means for deconvoluting comprises computing means for:

constructing a detector signal matrix from the detector signals;

multiplying the detector signal matrix by a deconvolution matrix to produce a spectrum matrix; and

truncating the spectrum matrix after the first L elements to produce a pseudorandom spectrum.

26. An analytical device comprising:

a source assembly comprising a plurality of sources, the sources spatially arrayed pseudo-randomly in at least a first dimension; and

a detector assembly spaced from the source assembly, the detector assembly comprising a number of sensors sensitive to an output of the plurality of sources,

wherein each of the plurality of sources is an ion emitter source and the detector comprises an array of particle detectors.

27. The analytical device of claim 26 wherein the detector comprises an array of ion detectors.

28. The analytical device of claim 27 wherein the detector comprises an array of Faraday cups.

29. The analytical device of claim 26 wherein the number of sensors in the detector assembly is less than a number of sources in the source assembly.

30. The analytical device of claim 26 wherein the number of sensors in the detector assembly is equal to N+L−

1 where N is the number of sources and L is the length of a spectrum.

31. The analytical device of claim 26 wherein the plurality of sources and the number of sensors arranged about respective concentric circles.

32. The analytical device of claim 26 wherein the ion emitter source is based on electron impact, field ionization or photoionization.

33. The analytical device of claim 26 wherein the ion emitter source is base on field ionization.

34. The analytical device of claim 26 wherein there are 2n-1 sources arranged in a pseudo-random sequence of a length equal to 2n-1.

35. The analytical device of claim 26 wherein each of the plurality of sources are formed on a common substrate.

36. The analytical device of claim 26 wherein each of the plurality of sources are micro-machined structures on a common substrate.

37. The analytical device of claim 26 wherein the plurality of sources are arranged about a closed surface.

38. The analytical device of claim 26 wherein the plurality of sources are arranged about a circle.

39. The analytical device of claim 26 wherein the plurality of sources are spatially arrayed pseudo-randomly in at least a second dimension.

40. The analytical device of claim 26 wherein the plurality of sources are spatially arrayed pseudo-randomly by a respective pseudo-random number of blanks between each respective pair of the sources in the array.

41. The analytical device of claim 26 further comprising a dispersion element positioned in a path between at least one of the plurality of sources and at least one of the sensors to disperse the output of at least one of the plurality of sources.

42. The analytical device of claim 41 wherein the dispersion element comprises a magnetic assembly positioned to create a magnetic field in the path between at least one of the plurality of sources and at least one of the sensors to disperse the output of at least one of the plurality of sources.

43. A mass spectrometer, comprising:

an ion source assembly comprising a plurality of ion sources, the sources spatially arrayed pseudo-randomly in at least a first dimension;

an ion detector assembly spaced from the source assembly, the ion detector assembly comprising a number of sensors sensitive to an output of the plurality of sources; and

a computer coupled to the detector assembly to receive detector signals therefrom corresponding to the output of the plurality of ion sources sensed by the number of sensors, the computer programmed to process the detector signals via a deconvolution algorithm.

44. The mass spectrometer of claim 43 wherein the computer is programmed to process the detector signals via a deconvolution algorithm by:

constructing a detector signal matrix from the detector signals;

multiplying the detector signal matrix by a deconvolution matrix to produce a spectrum matrix; and

truncating the spectrum matrix after the first L elements to produce a pseudorandom spectrum.

45. The mass spectrometer of claim 43 wherein the number of sensors in the detector assembly is equal to N+L−

1 where N is the number of sources and L is the length of a spectrum.

46. A mass spectrometer system, comprising:

an ion source assembly comprising a plurality of ion sources spatially arrayed in at least a first dimension;

an ion detector assembly spaced from the source assembly, the ion detector assembly comprising a number of sensors sensitive to an output of the plurality of sources; and

a computer coupled to control activation of the ion sources in a spatially pseudo-random order in at least a first dimension,

wherein the computer is coupled to control activation of the ion sources in a spatially pseudo-random order in at least a first dimension by;

activating successive ones of the plurality of sources with a respective pseudo-random number of unactivated sources between each respective pair of the activated sources in the array.

47. The mass spectrometer system of claim 46 wherein the plurality of ion sources are spatially arrayed uniformly in the first dimension.