Spectrum Searching Method That Uses Non-Chemical Qualities of the Measurement

Abstract

Methods and systems for determining information about a sample are disclosed. The methods can include measuring spectral information for the sample and determining a quantity related to a signal-to-noise ratio for the spectral information, repeating the measuring and determining until a value of the quantity is beyond a threshold value, and comparing the spectral information to reference information to determine the information about the sample.

1 - 39 . (canceled) 
   
   
       40 . A method, comprising:
 measuring spectral information for a sample and determining a quantity related to a signal-to-noise ratio for the spectral information;   determining whether the quantity is beyond a threshold value of the quantity;   if the quantity is not beyond the threshold value:
 measuring additional spectral information for the sample; 
 combining the additional measured spectral information with previously measured spectral information; 
 determining a new value of the quantity based on the combined spectral information; 
 determining whether the new value of the quantity is beyond the threshold value; and 
 repeating the measuring additional spectral information, combining the additional measured spectral information with previously measured spectral information, determining a new value of the quantity, and determining whether the new value of the quantity is beyond the threshold value, until the new value of the quantity is beyond the threshold value; and 
   comparing the combined spectral information to reference information to determine information about the sample.   
   
   
       41 . The method of  claim 40 , wherein the quantity is the signal-to-noise ratio of the measured spectral information. 
   
   
       42 . The method of  claim 40 , further comprising, if an elapsed measurement time exceeds a threshold measurement time, halting further measurement of spectral information. 
   
   
       43 . The method of  claim 40 , further comprising adjusting an operating characteristic of a detection system used to measure the spectral information prior to measuring at least some of the additional spectral information. 
   
   
       44 . The method of  claim 43 , wherein the operating characteristic is a temperature of the detection system. 
   
   
       45 . The method of  claim 43 , wherein the operating characteristic is an aperture of the detection system. 
   
   
       46 . The method of  claim 43 , wherein the operating characteristic is a gain of the detection system. 
   
   
       47 . The method of  claim 43 , wherein adjusting the operating characteristic comprises adjusting an optical configuration of the detection system. 
   
   
       48 . The method of  claim 47 , wherein adjusting the optical configuration comprises adjusting a position of one or more optical components in the detection system. 
   
   
       49 . The method of  claim 40 , further comprising adjusting an amount of ambient light detected by a detection system used to measure the spectral information prior to measuring at least some of the additional spectral information. 
   
   
       50 . The method of  claim 40 , further comprising adjusting a position of a detection system used to measure the spectral information prior to measuring at least some of the additional spectral information. 
   
   
       51 . The method of  claim 40 , further comprising adjusting a detection system used to measure the spectral information to increase an intensity of Raman scattered light emitted by the sample. 
   
   
       52 . The method of  claim 51 , wherein adjusting the detection system comprises increasing an intensity of illumination radiation incident on the sample and generated by a radiation source. 
   
   
       53 . The method of  claim 40 , further comprising adjusting a detection system used to measure the spectral information to increase an intensity of reflected or transmitted infrared radiation from the sample. 
   
   
       54 . The method of  claim 53 , wherein adjusting the detection system comprises increasing an intensity of illumination radiation incident on the sample and generated by a radiation source. 
   
   
       55 . The method of  claim 40 , wherein the reference information comprises information about a plurality of candidates in a library. 
   
   
       56 . The method of  claim 40 , wherein determining information about the sample comprises determining an identity of the sample. 
   
   
       57 . The method of  claim 40 , wherein determining information about the sample comprises determining that the sample comprises a mixture of two or more components. 
   
   
       58 . The method of  claim 40 , wherein determining information about the sample comprises determining that the sample does not comprise any of a plurality of candidates in the reference information. 
   
   
       59 . The method of  claim 40 , wherein determining information about the sample comprises determining information about a hazardousness of the sample. 
   
   
       60 . The method of  claim 40 , wherein determining information about the sample comprises determining whether an identity of the sample can be determined based on the measured spectral information. 
   
   
       61 . The method of  claim 40 , wherein the measured spectral information comprises at least one of Raman scattering information, infrared absorption information, infrared reflectance information, and fluorescence information for the sample. 
   
   
       62 . The method of  claim 40 , wherein determining the quantity related to the signal-to-noise ratio comprises determining a distribution of measured values of the spectral information. 
   
   
       63 . The method of  claim 62 , wherein measuring the spectral information comprises measuring information in a plurality of spectral channels, and determining the quantity related to the signal-to-noise ratio comprises determining a variance for each of the spectral channels, and determining the quantity based on the variances. 
   
   
       64 . The method of  claim 40 , wherein determining the quantity related to the signal-to-noise ratio comprises determining one or more uncertainties associated with measured values of the spectral information. 
   
   
       65 . The method of  claim 40 , wherein determining the quantity related to the signal-to-noise ratio comprises determining a probability of identifying the sample based on the reference information. 
   
   
       66 . The method of  claim 40 , wherein determining the quantity related to the signal-to-noise ratio comprises determining a probability that the sample corresponds to a portion of the reference information associated with one or more pure compounds. 
   
   
       67 . The method of  claim 40 , wherein comparing the combined spectral information to reference information comprises determining an extent of overlap between the measured spectral information and reference information corresponding to each of a plurality of candidates. 
   
   
       68 . The method of  claim 67 , wherein the reference information corresponding to each of the candidates comprises an expected distribution of values of the measured spectral information for each candidate. 
   
   
       69 . The method of  claim 68 , further comprising determining the expected distribution of values for each of the candidates based on an expected noise or error level in a detection system used to measure the spectral information. 
   
   
       70 . The method of  claim 69 , wherein the expected noise or error level comprises at least one of a dark current noise level in the detection system, a read noise level in the detection system, a quantization error in the detection system, a defect error level in the detection system, a gain error level in the detection system, a viability error level in the detection system, and a shot noise level in the detection system. 
   
   
       71 . The method of  claim 68 , further comprising determining the expected distribution of values for each of the candidates based on a temperature of a detection system or a humidity of an environment around the detection system used to measure the spectral information. 
   
   
       72 . The method of  claim 68 , further comprising determining the expected distribution of values based on a selected distribution. 
   
   
       73 . The method of  claim 72 , wherein the selected distribution comprises at least one of a multivariate normal distribution, a log-normal distribution, a Poisson distribution, an inverse Gaussian distribution, a Wishart distribution, and a Snedecor's F-distribution. 
   
   
       74 . The method of  claim 68 , wherein determining the extent of overlap comprises determining, for at least some measured values of spectral information displaced from a center of the expected distribution of values by a first distance, a probability that additional measured values of spectral information would be displaced from the center by an amount greater than the first distance. 
   
   
       75 . The method of  claim 40 , further comprising not combining all of the additional spectral information with the previously measured spectral information. 
   
   
       76 . A method, comprising:
 measuring spectral information for a sample and determining a quantity related to a signal-to-noise ratio for the spectral information;   repeating the measuring and determining until a value of the quantity is beyond a threshold value; and   comparing the spectral information to reference information to determine information about the sample.   
   
   
       77 . The method of  claim 76 , wherein the quantity is a signal-to-noise ratio for the spectral information. 
   
   
       78 . The method of  claim 76 , further comprising combining the measured spectral information with previously measured spectral information prior to determining the quantity. 
   
   
       79 . The method of  claim 76 , further comprising, if an elapsed measurement time exceeds a threshold measurement time, halting further measurement of spectral information. 
   
   
       80 . The method of  claim 76 , further comprising adjusting an operating characteristic of a detection system used to measure the spectral information prior to measuring at least some of the spectral information. 
   
   
       81 . The method of  claim 76 , wherein determining information about the sample comprises at least one of determining an identity of the sample, determining that the sample comprises a mixture of two or more components, and determining that the sample does not comprise any of a plurality of candidates in the reference information. 
   
   
       82 . The method of  claim 76 , wherein comparing the spectral information to reference information comprises determining an extent of overlap between the measured spectral information and reference information corresponding to each of a plurality of candidates. 
   
   
       83 . The method of  claim 82 , wherein the reference information corresponding to each of the candidates comprises an expected distribution of values of the measured spectral information for each candidate. 
   
   
       84 . The method of  claim 83 , further comprising determining the expected distribution of values for each of the candidates based on at least one of an expected noise or error level in a detection system used to measure the spectral information, a temperature of the detection system, a humidity of an environment around the detection system, and a selected distribution. 
   
   
       85 . The method of  claim 83 , wherein determining the extent of overlap comprises determining, for at least some measured values of spectral information displaced from a center of the expected distribution of values by a first distance, a probability that additional measured values of spectral information would be displaced from the center by an amount greater than the first distance. 
   
   
       86 . The method of  claim 78 , further comprising combining only a portion of the measured spectral information with previously measured spectral information prior to determining the quantity. 
   
   
       87 . The method of  claim 76 , wherein determining the quantity related to the signal-to-noise ratio comprises determining one or more uncertainties associated with measured values of the spectral information. 
   
   
       88 . The method of  claim 76 , wherein determining the quantity related to the signal-to-noise ratio comprises determining a probability of identifying the sample based on the reference information. 
   
   
       89 . The method of  claim 76 , wherein determining the quantity related to the signal-to-noise ratio comprises determining a probability that the sample corresponds to a portion of the reference information associated with one or more pure compounds. 
   
   
       90 . A system, comprising:
 a radiation source configured to direct incident radiation to a sample;   a detector configured to measure radiation from the sample; and   an electronic processor configured to:
 determine spectral information for a sample based on the measured radiation; 
 determine a quantity related to a signal-to-noise ratio for the spectral information; 
 repeat the measuring radiation, determining spectral information, and determining the quantity until a value of the quantity is beyond a threshold value; and 
 compare the spectral information to reference information to determine information about the sample. 
   
   
   
       91 . The system of  claim 90 , wherein the electronic processor is configured to combine the spectral information with previously determined spectral information prior to determining the quantity. 
   
   
       92 . The system of  claim 91 , wherein the electronic processor is configured to selectively combine only some of the spectral information with previously determined information prior to determining the quantity. 
   
   
       93 . The system of  claim 90 , wherein the electronic processor is configured to halt further measurement of radiation if an elapsed measurement time exceeds a threshold measurement time. 
   
   
       94 . The system of  claim 90 , wherein the electronic processor is configured to adjust an operating characteristic of the detector prior to measuring at least some of the radiation. 
   
   
       95 . The system of  claim 90 , wherein determining information about the sample comprises at least one of determining an identity of the sample, determining that the sample comprises a mixture of two or more components, and determining that the sample does not comprise any of a plurality of candidates in the reference information. 
   
   
       96 . The system of  claim 90 , wherein determining the quantity related to a signal-to-noise ratio comprises at least one of determining one or more uncertainties associated with measured values of the spectral information, determining a probability of identifying the sample based on the reference information, and determining a probability that the sample corresponds to a portion of the reference information associated with one or more pure compounds. 
   
   
       97 . The system of  claim 90 , wherein the electronic processor is configured to compare the spectral information to reference information by determining an extent of overlap between the spectral information and reference information corresponding to each of a plurality of candidates. 
   
   
       98 . The system of  claim 97 , wherein the reference information corresponding to each of the candidates comprises an expected distribution of values of the spectral information for each candidate. 
   
   
       99 . The system of  claim 98 , wherein the electronic processor is configured to determine the expected distribution of values for each of the candidates based on at least one of an expected noise or error level in the detector, a temperature of the detector, a humidity of an environment around the detector, and a selected distribution. 
   
   
       100 . The system of  claim 98 , wherein the electronic processor is configured to determine the extent of overlap by determining, for at least some values of the spectral information displaced from a center of the expected distribution of values by a first distance, a probability that additional determined values of spectral information would be displaced from the center by an amount greater than the first distance.