Computer operated spectrometric instrument and associated calculator

• US 6,122,052 A
• Filed: 04/27/1999
• Issued: 09/19/2000
• Est. Priority Date: 04/27/1998
• Status: Expired due to Term

• Current Assignee: Perkinelmer Instruments LLC (Revvity, Inc.)
• Original Assignee: Perkinelmer Incorporated
• Inventors: Carozza, Mario, Paul, Steven L., Paul, Gerard T., Bajorinas, Andrew P., Barnes, Robert F., Williams, J. Fenton, Stoltze, Mark W., Eaton, David J.
• Primary Examiner(s): EVANS, FANNIE L
• Application Number:
  US09/300,609
• Time in Patent Office: 511 Days
• Field of Search: 356/319, 356/323, 356/325, 356/326, 356/328
• US Class Current: 356/328
• CPC Class Codes: G01J 2003/1828 with order sorter or prefilter
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08

Abstract

A spectrometric instrument passes flashing light through a sample and has a linear detector operated by the computer to integrate signals for an established number of flashes to obtain an integrated unit of the signal data, from which spectral information is displayed on a monitor. Over a full spectral range, the established number is determined as that which effects a highest peak height proximately below a preselected maximum, and light source voltage is adjusted to bring the peak height closer to the maximum. For a narrower spectral range, an operating number of flashes for a unit is increased above the established number to accommodate a lower highest peak in the range. Wavelength calibration uses peaks in the light source. Corrections are made for stray light and non-linearity of detector response. Calculation of auxiliary information derived from input of auxiliary data through a touch screen is displayed on the monitor.

Claims

1. A spectrometric instrument comprising a flashing light source for emitting a flashing source beam of light, operating means for flashing the light source, a receptacle for a light-absorbing sample receptive of the source beam to pass a transmitted beam, a dispersion element receptive of the transmitted beam to effect dispersed light therefrom, a detector receptive of the dispersed light for effecting corresponding signal data representative of the transmitted beam, and processing means receptive of the signal data for effecting corresponding spectral data representative of the transmitted beam and thereby a sample in the receptacle, the detector comprising integration means for integrating signals for an established number of flashes to effect an integrated unit of the signal data.

2. The instrument of claim 1 wherein the operating means flashes the light source for a preselected flash total number of flashes equal to a multiple of the established number, the detector is operatively connected to the operating means for effecting a corresponding multiplicity of integrated units of signal data, and the processing means comprises adding means for adding the multiplicity of units of signal data to effect the spectral data.

3. The instrument of claim 2 wherein the operating means holds the flash total constant for successive operations of the instrument with variations in the established number.

4. The instrument of claim 1 wherein, to determine the established number of flashes:

the operating means is operatively connected to the processing means, and comprises means for operating the instrument without a sample, with a selected source voltage, and with a preliminary number as the established number, so as to generate preliminary spectral data; and

the processing means comprises means for ascertaining a highest peak in the preliminary spectral data and an associated preliminary peak height, and means for comparing the preliminary peak height with a preselected maximum peak height to determine an adjusted number of flashes required to effect a unit of signal data and corresponding spectral data with a corresponding peak height for the highest peak, the corresponding peak height being equal to or proximately below the maximum peak height, the adjusted number being stored for use as the established number of flashes in an integrated unit for subsequent operation of the instrument.

5. The instrument of claim 4 wherein the operating means drives the light source with a source voltage such that the light source has an intensity with a dependence on the source voltage, and further comprises means for determining an operational voltage required to effect an associated peak height at the associated spectral position, the associated peak height being equal to or adjacently below the maximum peak height, and the operational source voltage being set for driving the light source for subsequent operation of the instrument.

6. The instrument of claim 5 wherein the operational means further comprises means for operating the instrument with the adjusted number as the established number of flashes, said operating being firstly with a first source voltage so as to generate corresponding spectral data with a first peak height for the highest peak, and secondly with a second source voltage so as to generate corresponding spectral data with a second peak height for the highest peak, the highest peak being that ascertained in the preliminary spectral data and having an associated spectral position;

and

the processing means further comprises means for determining a functional dependence between source voltage and peak height by utilizing the first and second source voltage and the first and second peak height, and means for determining from the functional dependence an operational voltage required to effect an associated peak height at the associated spectral position, the associated peak height being equal to or adjacently below the maximum peak height, and the operational source voltage being set for driving the light source for subsequent operation of the instrument.

7. The instrument of claim 6 wherein the instrument is operated without a sample to generate the preliminary spectral data, and to generate corresponding spectral data with the first peak height and the second peak height.

8. The instrument of claim 4 wherein:

the adjusted number of flashes is determined with the processing means effecting spectral data for a full spectral range, and a narrower spectral range within the full spectral range is selected for a selected sample;

the operating means further comprises means for operating the instrument with the selected sample and with the adjusted number as the established number of flashes;

the processing means further comprises means for effecting corresponding spectral data in the narrower spectral range, means for ascertaining a highest peak in said corresponding spectral data and a corresponding preliminary peak height, and means for computing an integer ratio that approximates an actual ratio of the preselected maximum peak height to the preliminary peak height, and means for multiplying the adjusted number by the integer ratio to determine an operating number for the established number of flashes;

the operating means further comprises means for operating the instrument with the selected sample and the operating number as the established number of flashes; and

the processing means further comprises means for effecting preliminary spectral data for the selected sample in the narrower spectral range with the operating number, and means for dividing the preliminary spectral data by the integer ratio to effect sample spectral data representative of the selected sample.

9. The instrument of claim 8 wherein the operating number is determined without a sample.

10. The instrument of claim 8 wherein the operating means flashes the light source for a preselected flash total number of flashes equal to a multiple of the established number, the detector is operatively connected to the operating means for effecting a corresponding multiplicity of integrated units of signal data, and the processing means comprises adding means for adding the multiplicity of units of signal data to effect the spectral data.

11. The instrument of claim 10 wherein the operating means holds the flash total constant for successive operations of the instrument with variations in the established number.

12. The instrument of claim 1 wherein the source beam comprises a plurality of spectral peaks having predetermined spectral positions, the instrument further comprises operating means for operating the instrument such that the processing means effects corresponding spectral data including measured spectral positions of the spectral peaks, and the operating means further comprises means for calibrating the measured spectral positions against the predetermined spectral positions.

13. The instrument of claim 12 wherein the instrument is operated without a sample for effecting the measured spectral positions.

14. The instrument of claim 1 wherein:

the control means further comprises means for operating the instrument repetitively with a dark sample that passes a low transmitted beam compared to the source beam so as to effect a series of integrated units of dark spectral data, the series being for a number set of a multiplicity of numbers of flashes; and

the processing means further comprises means for effecting a sequence of dark spectral data over the number set for each of preselected spectral positions, means for computing a master function representative of the sequence over the number set for all of the preselected spectral positions, storing the master function, and applying the master function as a correction factor to measured spectral data to correct for non-linearity.

15. The instrument of claim 14 wherein the means for computing the master function comprises means for computing ratios of the sequenced dark spectral data to corresponding number of flashes, fitting the ratios against number of flashes to a position function for each preselected position, ascertaining a set of high points and a value for each such high point in each position function including a highest point for an associated highest position function, utilizing the high points to normalize the position functions to the highest position function so as to create a set normalized functions, and averaging the normalized functions to create the master function.

16. The instrument of claim 14 wherein the established number of flashes for an integrated unit is one.

17. The instrument of claim 1 wherein:

the instrument further comprises operating means for operating the instrument without a sample to generate open beam measured spectral data, and with a standard sample to generate standard measured spectral data, the standard sample having a high absorbance in a selected spectral range, and the spectral data being over a selected number of spectral increments in the selected spectral range; and

the processing means comprises means for dividing the measured spectral data by the number of spectral increments to respectively effect open beam reduced spectral data and standard reduced spectral data, means for subtracting a stray light correction value from the reduced spectral data to respectively effect open beam corrected spectral data and standard corrected spectral data, means for computing a corrected standard absorbance from the corrected spectral data, and means for iteratively determining the stray light correction value such that the corrected standard absorbance substantially equals a pre-established standard absorbance, and means for substracting the stray light correction value from subsequently generated spectral data to correct for stray light.

18. The instrument of claim 17 wherein the means for iteratively determining comprises means for integrating and normalizing the standard reduced spectral data to effect an average, and iteratively determining a factor such that the stray light correction value is a multiplication product of the average and the factor.

19. The instrument of claim 1 further comprising a display monitor, means for displaying the spectral information on the monitor, a touch screen overlayed on the monitor, means for calculating auxiliary information derived from input of auxiliary data through the touch screen, and means for displaying the auxiliary information on the monitor, the auxiliary information being associated with the sample.

20. A spectrometric instrument comprising a light source for emitting a source beam of light, a receptacle for a light-absorbing sample receptive of the source beam to pass a transmitted beam, a dispersion element receptive of the transmitted beam to effect dispersed light therefrom, a detector receptive of the dispersed light for effecting corresponding signal data representative of the transmitted beam, and processing means receptive of the signal data for effecting corresponding spectral data representative of the transmitted beam and thereby a sample in the receptacle, the detector comprising integration means for integrating signals for an established duration to effect an integrated unit of the signal data;

wherein, to determine the established duration;

an operating is operatively connected to the processing means, and comprises means for operating the instrument without a sample and with a preliminary duration of integrating signals, so as to generate preliminary spectral data; and

the processing means comprises means for ascertaining a highest peak in the preliminary spectral data and an associated preliminary peak height, and means for comparing the preliminary peak height with a preselected maximum peak height to determine an adjusted duration required to effect a unit of signal data and corresponding spectral data with a corresponding peak height for the highest peak, the corresponding peak height being equal to or proximately below the maximum peak height, the adjusted duration being stored for use as the established duration for subsequent operation of the instrument.

21. The instrument of claim 20 wherein:

the adjusted duration is determined with the processing means effecting spectral data for a full spectral range, and a narrower spectral range within the full spectral range is selected for a selected sample;

the operating means further comprises means for operating the instrument with the selected sample and with the adjusted duration;

the processing means further comprises means for effecting corresponding spectral data in the narrower spectral range, means for ascertaining a highest peak in said corresponding spectral data and a corresponding preliminary peak height, and means for computing an integer ratio that approximates an actual ratio of the preselected maximum peak height to the preliminary peak height, and means for multiplying the adjusted duration by the integer ratio to determine an operating duration;

the operating means further comprises means for operating the instrument with the selected sample and the operational duration;

the processing means further comprises means for effecting preliminary spectral data for the selected sample in the narrower spectral range with the operational duration, and means for dividing the preliminary spectral data by the simple ratio to effect sample spectral data representative of the selected sample.

22. A spectrometric instrument with means for wavelength calibration, the instrument comprising a light source for emitting a source beam of light comprising a plurality of spectral peaks having predetermined spectral positions, a receptacle for a light-absorbing sample receptive of the source beam to pass a transmitted beam, a dispersion element receptive of the transmitted beam to effect dispersed light therefrom, a detector receptive of the dispersed light for effecting corresponding signal data representative of the transmitted beam, and processing means receptive of the signal data for effecting corresponding spectral data representative of the transmitted beam and thereby a sample in the receptacle, wherein the instrument further comprises operating means for operating the instrument such that the processing means effects corresponding spectral data including measured spectral positions of the spectral peaks, and the operating means further comprises means for calibrating the measured spectral positions against the predetermined spectral positions by fitting to a calibration function the ratios of the measured positions to the known positions.

23. The instrument of claim 22 wherein the instrument is operated without a sample for effecting the measured spectral positions.

24. A spectrometric instrument with means to correct for stray light, the instrument comprising a light source for emitting a source beam of light, a receptacle for a light-absorbing sample receptive of the source beam to pass a transmitted beam, a dispersion element receptive of the transmitted beam to effect dispersed light therefrom, a detector receptive of the dispersed light for effecting corresponding signal data representative of the transmitted beam, processing means receptive of the signal data for effecting corresponding spectral data representative of the transmitted beam and thereby a sample in the receptacle, and operating means for operating the instrument without a sample to generate open beam measured spectral data, and with a standard sample to generate standard measured spectral data, the standard sample having a high absorbance in a selected spectral range, the spectral data being over a selected number of spectral increments in the selected spectral range, and the processing means comprising means for dividing the measured spectral data by the number of spectral increments to respectively effect open beam reduced spectral data and standard reduced spectral data, means for subtracting a stray light correction value from the reduced spectral data to respectively effect open beam corrected spectral data and standard corrected spectral data, means for computing a corrected standard absorbance from the corrected spectral data, and means for iteratively determining the stray light correction value such that the corrected standard absorbance substantially equals a pre-established standard absorbance, and means for subtracting the stray light correction value from subsequently generated spectral data to correct for stray light.

25. The instrument of claim 24 wherein the means for iteratively determining comprises means for integrating and normalizing the standard reduced spectral data to effect an average, and iteratively determining a factor such that the stray light correction value is a multiplication product of the average and the factor.

26. An integrated spectrometric instrument comprising a spectrometer, a data processor, a display monitor, a touch screen overlayed on the monitor, and light means for effecting a light beam representative of a sample, the spectrometer being receptive of the light beam for effecting spectrometric signal data representative thereof, wherein the processor comprises means receptive of the signal data for computing corresponding spectral information representative of the light beam and thereby the sample, means for displaying the spectral information on the monitor, means for calculating auxiliary information derived from input of auxiliary data through the touch screen, and means for displaying the auxiliary information on the monitor, the auxiliary information being associated with the sample.

27. The instrument of claim 26 wherein the auxiliary information for at least one of the types of information is further derived from the spectral information.

28. The instrument of claim 27 wherein the auxiliary information for at least one of the types of information is not further derived from the spectral information.

29. The instrument of claim 26 wherein the auxiliary information for at least one of the types of information is not further derived from the spectral information.

30. The instrument of claim 26 wherein the instrument is receptive of micro-biology samples.