METHOD FOR IDENTIFYING RAMAN SPECTROGRAM AND ELECTRONIC APPARATUS

• US 20190331604A1
• Filed: 11/24/2017
• Published: 10/31/2019
• Est. Priority Date: 12/26/2016
• Status: Active Grant

• Current Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.)
• Original Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.)
• Inventors: Gou, Wei, Zuo, Jiaqian, Fan, Rui
• Granted Patent: US 10,948,417 B2
• Time in Patent Office: Days
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06F 18/2413 based on distances to training or reference patterns
• CPC Class Codes: G06F 2218/10 by analysing the shape of a waveform, e.g. extracting parameters relating to peaks
• CPC Class Codes: G06F 2218/14 by matching peak patterns

Abstract

The disclosure provides a method for identifying a Raman spectrum and an electronic apparatus. The method includes steps of: measuring a Raman spectrum of a substance to be detected so as to obtain a measured spectrogram, the measured spectrogram including a series of data; extracting peak information of the measured spectrogram, the peak information including a peak intensity, a peak position and a peak area; comparing the peak information of the measured spectrogram with peak information of a prestored standard spectrogram so as to identify whether or not the peak information of the measured spectrogram matches the peak information of the standard spectrogram; and comparing, when identifying that the peak information of the measured spectrogram matches the peak information of the standard spectrogram, data of the measured spectrogram with data of the prestored standard spectrogram, so as to further identify whether or not the measured spectrogram matches the standard spectrogram.

Claims

1. A method of identifying a Raman spectrogram, comprising:

a measured spectrogram obtaining step;

measuring a Raman spectrum of a substance to be detected so as to obtain a measured spectrogram, the measured spectrogram including a series of data;

a peak information extraction step;

extracting peak information of the measured spectrogram, the peak information including a peak intensity, a peak position and a peak area;

a first identifying step;

comparing the peak information of the measured spectrogram with peak information of a prestored standard spectrogram so as to identify whether or not the peak information of the measured spectrogram matches the peak information of the standard spectrogram; and

a second identifying step;

comparing, when identifying in the first identifying step that the peak information of the measured spectrogram matches the peak information of the standard spectrogram, data of the measured spectrogram with data of the prestored standard spectrogram, so as to further identify whether or not the measured spectrogram matches the standard spectrogram.

2. The method according to claim 1, wherein the first identifying step comprises:

an ordering step;

ordering peaks of the measured spectrogram and peaks of the standard spectrogram in a descend order of a peak intensity respectively, so as to select first ordered N peaks of the measured spectrogram and the standard spectrogram;

a comparing step;

comparing peak position information between the first ordered N peaks of the measured spectrogram and the standard spectrogram; and

a first matching step;

determining whether or not the peak information of the measured spectrogram matches the peak information of the standard spectrogram based on a comparison result obtained in the comparing step.

3. The method according to claim 2, wherein the comparing step comprises:

calculating absolute differences between peak position of each of the first ordered N peaks of the measured spectrogram and peak position of each of the first ordered N peaks of the standard spectrogram in order in accordance with the following formula (1);

pD=|p2[j].fPos−

p1[i].fPos| 

 

formula (1),

where, N is a predetermined number of compared peaks and is a natural number larger than or equal to 3;

j represent order numbers of ordered peaks of the standard spectrogram and the measured spectrogram respectively, and i and j are each an integer larger than or equal to 0 and smaller than or equal to N;

p1[i].fPos represents a peak position of the i^th peak of the ordered peaks of the standard spectrogram;

p2[j].fPos represents a peak position of the j^th peak of the ordered peaks of the measured spectrogram; and

pD represents an absolute difference between peak positions.

4. The method according to claim 3, wherein the first matching step comprises:

determining that the peak information of the measured spectrogram matches the peak information of the standard spectrogram when the calculated absolute difference between the peak positions meets the following condition (1); and

determining that the peak information of the measured spectrogram does not match the peak information of the standard spectrogram when the calculated absolute difference between the peak positions does not meet the following condition (1);

pD<

p2[j].fWidth/3 and pD<

p1[i].fWidth/3 

 

condition (1),

where, p1[i].fWidth represents a peak width of the ordered i^th peak of the standard spectrogram; and

p2[j].fWidth represents a peak width of the ordered j^th peak of the measured spectrogram.

5. The method according to claim 2, wherein the first identifying step further comprises:

a peak matching weight calculation step;

establishing a penalty function in accordance with the following formula (2) so as to calculate a peak matching weight; and

a second matching step;

determining that the peak information of the measured spectrogram matches the peak information of the standard spectrogram when peak matching weight is larger than or equal to a weight threshold; and

determining that the peak information of the measured spectrogram does not match the peak information of the standard spectrogram when peak matching weight is smaller than the weight threshold,

h=(1−

2*|j−

i|/10)*(0.5/(i+1))*exp(−

pD*2/min(p1[i].fWidth,p2[j].fWidth)) 

 

formula (2),

where;

h represents a peak matching weight;

j represent order numbers of ordered peaks of the standard spectrogram and the measured spectrogram respectively, and i and j are each an integer larger than or equal to 0 and smaller than or equal to N;

N is a predetermined number of compared peaks and is a natural number larger than or equal to 3;

pD represents an absolute difference between peak positions;

p1[i].fWidth represents a peak width of the i^th peak of the ordered peaks of the standard spectrogram; and

p2[j].fWidth represents a peak width of the i^th peak of the ordered peaks of the measured spectrogram.

6. The method according to claim 5, wherein the peak matching weight calculation step and the second matching step are performed when determining in the first matching step that the peak information of the measured spectrogram matches the peak information of the standard spectrogram.

7. The method according to claim 2, wherein N is a natural number larger than or equal to three and smaller than or equal to five.

8. The method according to claim 1, wherein the second identifying step comprises:

comparing in correlation between data of the measured and data of the prestored standard spectrogram.

9. The method according to claim 8, wherein the comparing in correlation between data of the measured and data of the prestored standard spectrogram comprises:

calculating a correlation coefficient between the data of the measured spectrogram and the data of the prestored standard spectrogram;

determining that the measured spectrogram matches the standard spectrogram when the calculated correlation coefficient is larger than or equal to a preset correlation threshold; and

determining that the measured spectrogram does not matches the standard spectrogram when the calculated correlation coefficient is less than the preset correlation threshold.

10. The method according to claim 8, wherein the step of comparing in correlation between data of the measured and data of the prestored standard spectrogram is performed within a union section between peak areas of all of peaks of the measured spectrogram and the standard spectrogram.

11. The method according to claim 1, further comprises:

a normalization step;

normalizing the measured spectrogram and the standard spectrogram;

wherein the normalization step is performed before the peak information extraction step.

12. An electronic apparatus, comprising:

a memory configured for storing executable instructions therein; and

a processor configured to execute the executable instructions stored in the memory so as to perform the method of claim 1.