Systems and methods for testing conformity of samples using spectroscopic measurements

A computer program product for determining conformity of a fingerprint of a sample with a corresponding expected fingerprint of said sample, the computer program product being tangibly embodied on a non-transitory computer-readable storage medium and comprising instructions that, when executed by at least one computing device, are configured to cause the at least one computing device to:

• obtain a measured spectrum as the fingerprint of the sample, wherein the measured spectrum is a result of a measurement reflecting a current chemical and physical state of the sample obtained by vibrational spectroscopy;
• access a spectrum library comprising a plurality of calibrated reference spectra;
• identify a subset of the reference spectra in the spectrum library, wherein the subset is identified by determining representations of k nearest neighbor reference spectra in a vicinity of a corresponding representation of the measured spectrum in accordance with predefined metrics;
• compute, based on the identified subset, an averaged reference spectrum as the corresponding expected fingerprint, and computing a standard deviation in each data point of the k nearest neighbor reference spectra;
• determine a difference spectrum by computing the difference between measured spectrum and averaged reference spectrum divided by the corresponding standard deviation in each data point;
• determine deviating data points where a value of the difference spectrum exceeds a predefined deviation threshold;
• and
• determine conformity in accordance with a predefined conformity rule based on the data points exceeding said predefined deviation threshold.

A system comprising:

• at least one memory including instructions;
• and
• at least one processor that is operably coupled to the at least one memory and that is arranged and configured to execute instructions that, when executed, cause the at least one processor to:
• obtain a measured spectrum as the fingerprint of the sample, wherein the measured spectrum is a result of a measurement reflecting a current chemical and physical state of the sample obtained by vibrational spectroscopy;
• access a spectrum library comprising a plurality of calibrated reference spectra;
• identify a subset of the reference spectra in the spectrum library, wherein the subset is identified by determining representations of k nearest neighbor reference spectra in a vicinity of a corresponding representation of the measured spectrum in accordance with predefined metrics;
• compute, based on the identified subset, an averaged reference spectrum as the corresponding expected fingerprint, and computing a standard deviation in each data point of the k nearest neighbor reference spectra;
• determine a difference spectrum by computing the difference between measured spectrum and averaged reference spectrum divided by the corresponding standard deviation in each data point;
• determine deviating data points where a value of the difference spectrum exceeds a predefined deviation threshold;
• and
• determine conformity in accordance with a predefined conformity rule based on the data points exceeding said predefined deviation threshold.