Waveform data processing device and waveform data processing program

Patent metadata

Field	Value
Publication number	US-10371676-B2
Application number	US-201315026686-A
Country	US
Kind code	B2
Filing date	Oct 4, 2013
Priority date	Oct 4, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A waveform data processing device 30 capable of accessing a storage device 40 for storing data on an observed waveform such as a chromatogram, information on a starting point and an ending point of a peak cluster consisting of a plurality of peaks close one another present on the observed waveform, and information on a position of each peak included in the peak cluster and a positive/negative direction of the each peak, includes baseline determination means for determining, based on the data and the information stored in the storage device 40 , a shortest straight line or shortest line segments from the starting point of the peak cluster as a beginning point to the ending point of the peak cluster as a finishing point satisfying all following conditions, and determining the straight line or the line segments to be a baseline of the peak cluster: (1) in a section where positive peaks are contiguous, a baseline passes below the observed waveform, becoming a straight line or line segments convex downward; (2) in a section where negative peaks are contiguous, a baseline passes above the observed waveform, becoming a straight line or line segments convex upward; and (3) in a section where positive and negative peaks are contiguous, the shape of a baseline is not influenced by the observed waveform.

First claim

The invention claimed is:

1. A waveform data processing device capable of accessing a storage device for storing, together with data of an observed waveform, information on peaks existing on the observed waveform previously extracted based on data of the observed waveform obtained with a sample measurement device, information on a starting point and an ending point of a peak cluster consisting of a plurality of peaks close to one another present on the observed waveform, and information on a position of each peak included in the peak cluster and a positive/negative direction of the each peak, the waveform data processing device comprising:
baseline determination means for determining, based on the data of the observed waveform and the information on the peak and the peak cluster stored in the storage device, a baseline of the peak cluster,
wherein the baseline determination means determines, when two or more points of intersection are found between a line segment connecting the starting point and the ending point of the peak cluster and the observed waveform except for the starting point and the ending point of the line segment, and at least one of sections on the observed waveform of the peak cluster each lying between two adjoining points of intersection of the two or more points of intersection includes no positions corresponding to the position of each peak included in the peak cluster stored in the storage, that the line segment satisfies correction requirements;
the baseline determination means determines, when the line segment does not satisfy the correction requirements, the line segment to be the baseline of the peak cluster; and
the base line determination means determines, when the line segment satisfies the correction requirements, a shortest straight line or shortest line segments from the starting point of the peak cluster as a beginning point to the ending point of the peak cluster as a finishing point satisfying all following conditions, and determines the straight line or the line segments to be the baseline of the peak cluster:
(1) in a section where positive peaks are contiguous, a baseline passes below the observed waveform, becoming a straight line or line segments convex downward;
(2) in a section where negative peaks are contiguous, a baseline passes above the observed waveform, becoming a straight line or line segments convex upward; and
(3) in a section where positive and negative peaks are contiguous, the shape of a baseline is not affected by the observed waveform.

2. The waveform data processing device according to claim 1 , further comprising:
peak-valley determination means for, in a case where there exist peaks directly preceding and following a positive or negative peak in the peak cluster having a positive or negative direction opposite to that of the positive or negative peak, determining that the positive peak or the negative peak is not a peak but a valley between the preceding and following peaks when the observed waveform does not intersect with a baseline of the peak cluster determined by the baseline determination means in a section between a peak top of the positive or negative peak and peak tops of the preceding and following peaks.

3. The waveform data processing device according to claim 1 , wherein
the baseline determination means performs:
a preliminary baseline correction step of, for the line segment determined in the determination step to satisfy the correction requirements, determining two line segments that minimize an angle between the two line segments connecting any point on a section on the observed waveform lying between the two adjoining points of intersection and including no positions corresponding to the position of each peak included in the peak cluster stored in the storage, and both ends of the line segment, and substituting the two line segments, as a new preliminary baseline, for the line segment satisfying the correction requirements, and wherein
in the determination step, it is further determined whether or not the correction requirements are satisfied for each of the two line segments determined in the preliminary baseline correction step, and
the determination step and the preliminary baseline correction step are repeated until it is determined that no line segment included in the preliminary baseline satisfies the correction requirements, and a preliminary baseline finally obtained is determined to be a baseline of the peak cluster.

4. The waveform data processing device according to claim 1 , wherein
the baseline determination means determines the two line segments that maximize a sum of lengths of the two line segments connecting any point on the section on the observed waveform lying between the two adjoining points of intersection and including no positions corresponding to the position of each peak included in the peak cluster stored in the storage, and the both ends of the line segment determined to satisfy the correction requirements, and substitutes the two line segments, as a new preliminary baseline, for the line segment satisfying the correction requirements.

5. The waveform data processing device according to claim 2 , wherein
the baseline determination means performs:
a preliminary baseline correction step of, for the line segment determined in the determination step to satisfy the correction requirements, determining two line segments that minimize an angle between the two line segments connecting any point on a section on the observed waveform lying between the two adjoining points of intersection and including no positions corresponding to the position of each peak included in the peak cluster stored in the storage, and both ends of the line segment, and substituting the two line segments, as a new preliminary baseline, for the line segment satisfying the correction requirements, and wherein
in the determination step, it is further determined whether or not the correction requirements are satisfied for each of the two line segments determined in the preliminary baseline correction step, and
the determination step and the preliminary baseline correction step are repeated until it is determined that no line segment included in the preliminary baseline satisfies the correction requirements, and a preliminary baseline finally obtained is determined to be a baseline of the peak cluster.

6. A non-transitory computer readable media recording a waveform data processing program operable on a computer capable of accessing a storage device for storing, together with data of an observed waveform, information on peaks existing on the observed waveform previously extracted based on the data of the observed waveform obtained with a sample measurement device, information on a starting point and an ending point of a peak cluster consisting of a plurality of peaks close to one another present on the observed waveform, and information on a position of each peak included in the peak cluster and a positive/negative direction of the each peak, the waveform data processing program causing the computer to function as:
baseline determination means for determining, based on the data of the observed waveform and the information on the peak and the peak cluster stored in the storage device, a baseline of the peak cluster,
wherein the baseline determination means determines, when two or more points of intersection are found between a line segment connecting the starting point and the ending point of the peak cluster and the observed waveform except for the starting point and the ending point of the line segment, and at least one of sections on the observed waveform of the peak cluster each lying between two adjoining points of intersection of the two or more points of intersection includes no positions corresponding to the position of

Assignees

• Shimadzu Corp

Inventors

• Kozawa Hiroaki

Classifications

• G01N30/8641 Primary

  Baseline · CPC title

• G01N30/8637

  Peak shape · CPC title

• G01N30/8631

  Peaks · CPC title

• G01N2030/8648

  Feature extraction not otherwise provided for · CPC title

• G01N30/8624

  Detection of slopes or peaks; baseline correction · CPC title