Processing apparatus, program and method

Abstract

The challenge is to accurately calculate the concentration of the target substance. [Solution] The processing device acquires the absorbance spectrum of the droplet to be measured, calculates the concentration of the target based on calibration curve data showing the relationship between the slope when the absorbance spectrum is first differentiated and the concentration, and the slope when the acquired absorbance spectrum is first differentiated.

Description

Technical Field

[0001] The present invention relates to a processing device, a program, and a method.

Background Art

[0002] As a conventional technique for optically measuring the concentration of an object, there is ATR (Attenuated Total Reflection).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technique, there are cases where the concentration of the object cannot be accurately calculated, and there is room for improvement.

[0005] One aspect aims to provide a processing device, a program, and a method capable of accurately calculating the concentration of an object.

Means for Solving the Problems

[0006] The processing device according to one aspect includes a processor. The processor acquires the absorption spectrum of the droplet to be measured, and calculates the concentration of the measurement target based on the calibration curve data indicating the relationship between the slope when the absorption spectrum is differentiated by the first order and the concentration, and the slope when the acquired absorption spectrum is differentiated by the first order.

[0007] One aspect of the program involves instructing a computer to acquire the absorbance spectrum of the droplet to be measured, and to calculate the concentration of the target based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the acquired absorbance spectrum when it is first differentiated.

[0008] One approach involves a computer acquiring the absorbance spectrum of the droplet to be measured, and then calculating the concentration of the target based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the acquired absorbance spectrum after the first derivative. [Effects of the Invention]

[0009] According to one embodiment, the concentration of the target substance can be calculated with high accuracy. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram illustrating the system according to this embodiment. [Figure 2] This figure shows an example of calibration curve data. [Figure 3] This is a flowchart showing the processing procedure of the apparatus according to the embodiment. [Figure 4] This figure shows the absorbance spectrum after correction to the reference. [Figure 5] This figure shows the absorbance spectrum after spectral normalization. [Figure 6] This is a diagram illustrating the process of calculating the slope. [Figure 7] This is a functional block diagram showing the configuration of the processing apparatus according to this embodiment. [Figure 8] This is a diagram illustrating the processing of the generation unit. [Figure 9] This figure shows the effect of droplet adhesion rate. [Figure 10] Figure (1) shows the method for measuring the concentration of granular material. [Figure 11] Figure (2) shows the method for measuring the concentration of granular material. [Figure 12] This is a diagram for explaining an example of hardware configuration. [Figure 13] This is a diagram schematically showing an ATR. [Figure 14] This is a diagram for explaining a conventional technique (1) for calculating concentration from an absorption spectrum. [Figure 15] This is a diagram for explaining a conventional technique (2) for calculating concentration from an absorption spectrum.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the processing apparatus, program, and method disclosed in the present application will be described in detail based on the drawings. Note that the present invention is not limited by this embodiment. Also, the same elements are denoted by the same reference numerals, and redundant explanations are omitted as appropriate, and each embodiment can be combined as appropriate within a non - contradictory range.

[0012] (Supplement to the prior art) The above - mentioned prior art will be supplemented and explained. FIG. 13 is a diagram schematically showing an ATR. In FIG. 13, incident light 401 from a light source passes through a prism, undergoes total reflection at the surface where the measurement object 700 and the prism are in contact, and is emitted as outgoing light 402. In total reflection, the incident light penetrates into the measurement object 700 to a depth d and obtains the absorption information of the measurement object. Therefore, by measuring the outgoing light 402, an absorption spectrum caused by the measurement object can be obtained.

[0013] FIG. 14 is a diagram for explaining a conventional technique (1) for calculating concentration from an absorption spectrum. The vertical axis of the graph G1 in FIG. 14 corresponds to the absorbance axis, and the horizontal axis corresponds to the wavelength axis. The curve cu1 is an absorption spectrum showing the absorbance at each wavelength. Since the Lambert - Beer law shown in Equation (1) holds between the absorbance and the concentration, the concentration c can be obtained from the maximum value D1 of the curve cu1. Note that ε1 in Equation (1) is the absorption coefficient, and L is the optical path length.

[0014] D1 = ε1×c×L ···(1)

[0015] Figure 15 is a diagram illustrating the conventional technique (2) for calculating concentration from an absorption spectrum. In graph G2 of Figure 15, the vertical axis corresponds to the second derivative of absorbance, and the horizontal axis corresponds to the wavelength. Curve cu2 is the curve obtained by second-deriving the absorption spectrum, which shows the absorbance at each wavelength. The minimum value obtained by second-deriving the absorbance also satisfies the Lambert-Beer law shown in equation (2) with the concentration, so the concentration c can be determined from the minimum value D2 of curve cu2. In equation (2), ε2 is the absorption coefficient and L is the optical path length.

[0016] D2 = ε2 × c × L ···(2)

[0017] For example, while the above-mentioned conventional techniques are effective in wavelength ranges where only the absorbance of the object being measured appears, when using wavelength ranges where the absorbance of substances other than the object is mixed in, the wavelength and amplitude of each element change depending on the concentration and elemental arrangement of the object. As a result, the maximum value of the absorbance spectrum is not proportional to the concentration, making it difficult to accurately calculate the concentration.

[0018] (Embodiment) The processing of the apparatus according to this embodiment will now be described. In the following description, the apparatus according to this embodiment will be referred to as "processing apparatus 100".

[0019] (System Configuration) Figure 1 is a diagram illustrating the system according to this embodiment. As shown in Figure 1, this system includes a light source 10, a prism 11, a spectrometer 12, and a processing device 100.

[0020] The incident light 10a from the light source 10 passes through the prism 11, undergoes total internal reflection at the surface where the droplet 11a and the prism 11 are in contact, and is emitted as emitted light 11b. The emitted light 11b is input to the spectrometer 12. The droplet 11a is sandwiched between the prism 11 and a plate (not shown) and is filled with water.

[0021] The spectrometer 12 has a wavelength range that includes the wavelength absorbed by the liquid droplet 11a, which is the object to be measured, and has a measurement speed that can track changes in concentration. For example, the spectrometer 12 measures the absorption spectrum based on the total internal reflection method and outputs the absorption spectrum data to the processing device 100.

[0022] The processing device 100 stores calibration curve data 141 that shows the relationship between the slope when the absorbance spectrum is first differentiated and the concentration. Figure 2 shows an example of calibration curve data. In Figure 2, the calibration curve data 141 is shown by the line L1 in graph G3. The horizontal axis of graph G3 corresponds to the concentration axis, and the vertical axis corresponds to the slope when the absorbance spectrum is first differentiated. Line segment L1 shows the relationship between concentration and slope.

[0023] The processing unit 100 calculates the concentration of the droplet to be measured based on the slope of the first derivative of the absorption spectrum obtained from the spectrometer 12 and the calibration curve data 141. The processing of the processing unit 100 will be explained using Figure 2. For example, if the slope of the first derivative of the absorption spectrum obtained from the spectrometer 12 is "-8.0E-04", the processing unit 100 calculates a concentration of "20".

[0024] As described above, the processing device 100 can accurately calculate the concentration of the droplet to be measured by calculating the concentration of the droplet based on the slope of the first derivative of the absorption spectrum obtained from the spectrometer 12 and the calibration curve data 141.

[0025] (Processing details of the processing device) Next, the processing details of the processing apparatus 100 will be explained in more detail. Figure 3 is a flowchart of the processing procedure of the processing apparatus according to the embodiment. As shown in Figure 3, the processing apparatus 100 acquires absorbance spectrum data from the spectrometer 12 (step S101).

[0026] The processing unit 100 performs a reference correction on the absorbance spectrum (step S102). Step S102 is explained in more detail below. As a reference correction, the processing unit 100 performs a process to remove noise from the absorbance spectrum. For example, the processing unit 100 performs a reference correction by performing a DFT (Discrete Fourier Transform) on the absorbance spectrum and then performing an LPF (Low Pass Filter) process on the result of the DFT.

[0027] Figure 4 shows the absorbance spectrum after correction to the reference. In graph G4 shown in Figure 4, the vertical axis corresponds to absorbance, and the horizontal axis corresponds to wavelength. Curve cu3 is the absorbance spectrum after correction to the reference, with noise and other unwanted elements removed.

[0028] Returning to the explanation of Figure 3, the processing device 100 performs spectral normalization on the absorbance spectrum after reference correction (step S103). Step S103 is explained in more detail below. For example, the processing device 100 normalizes the absorbance spectrum so that the maximum value is "1".

[0029] Figure 5 shows the absorbance spectrum after spectral normalization. In graph G5 shown in Figure 5, the vertical axis corresponds to the normalized absorbance, and the horizontal axis corresponds to the wavelength. Curve cu4 shows the normalized absorbance spectrum.

[0030] Returning to the explanation of Figure 3, the processing device 100 calculates the slope by taking the first derivative of the absorbance spectrum that has undergone reference correction and spectral normalization (step S104). Step S104 will be explained in more detail below.

[0031] Figure 6 is a diagram illustrating the process of calculating the slope. In the graph G6 shown in Figure 6, the vertical axis corresponds to the absorbance obtained by the first derivative, and the horizontal axis corresponds to the wavelength. Curve cu5 is the curve obtained by the first derivative of the absorbance spectrum. Line segment L2 is a straight line representing the shape of the absorbance spectrum. The processing device 100 calculates the slope of line segment L2 as the slope in step S104.

[0032] Returning to the explanation of Figure 3, the processing device 100 calculates the concentration of the droplet to be measured based on the calculated slope and the calibration curve data 141 (step S105).

[0033] (Functional configuration of the processing unit 100) Next, an example of the configuration of the processing unit 100 will be described. Figure 7 is a functional block diagram showing the configuration of the processing unit according to this embodiment. As shown in Figure 7, the processing unit 100 has a communication unit 110, an input unit 120, a display unit 130, a storage unit 140, and a control unit 150.

[0034] The communication unit 110 communicates data with the spectrometer 12 and other external devices.

[0035] The input unit 120 inputs various types of information to the control unit 150. For example, the input unit 120 may be an input device such as a keyboard, mouse, or touch panel.

[0036] The display unit 130 displays information output from the control unit 150. The display unit 130 is a display device such as a display or touch panel. For example, the display unit 130 displays information on the concentration of liquid droplets output from the control unit 150.

[0037] The storage unit 140 stores calibration curve data 141, etc. The storage unit 140 is implemented using memory, a hard disk, or the like.

[0038] Calibration curve data 141 provides information showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration. The explanation for calibration curve data 141 is the same as the explanation given using Figure 2.

[0039] The control unit 150 is a processing unit that oversees the entire processing unit 100 and is implemented by, for example, a processor. The control unit 150 includes an acquisition unit 151, a calculation unit 152, and a generation unit 153.

[0040] The acquisition unit 151 acquires absorbance spectrum data from the spectrometer 12. The acquisition unit 151 outputs the absorbance spectrum data to the calculation unit 152. In addition, if the generation unit 153 is generating calibration curve data 141, the acquisition unit 151 outputs the absorbance spectrum data to the generation unit 153.

[0041] The calculation unit 152 calculates the concentration of the droplet to be measured based on the slope of the first derivative of the absorbance spectrum and the calibration curve data 141. The calculation unit 152 may output the calculated concentration data to the display unit 130 for display.

[0042] The explanation of other processes related to the calculation unit 152 is the same as the processes in steps S102 to S105 described in Figure 3.

[0043] The generation unit 153 generates calibration curve data 141. An example of the processing performed by the generation unit 153 is described below. First, the user sets a droplet of known concentration in the prism 11, and then operates the input unit 120 to input the droplet concentration and a command to generate calibration curve data 141 to the control unit 150.

[0044] When the generation unit 153 receives the droplet concentration and a generation command, it acquires absorbance spectrum data via the acquisition unit 151. After acquiring the absorbance spectrum, the generation unit 153 calculates the slope by executing the processes of steps S102 to S104 described in Figure 3, in the same manner as the calculation unit 152.

[0045] The generation unit 153 obtains multiple pairs of "droplet concentration" and "slope" by repeatedly performing the above process on droplets of different concentrations. Figure 8 is a diagram illustrating the process of the generation unit. In graph G7 of Figure 8, the horizontal axis corresponds to the concentration, and the vertical axis corresponds to the slope when the first derivative is taken. Points p1, p2, p3, p4, and p5 show the relationship between the slope and concentration obtained by the generation unit 153 repeatedly performing the above process. The generation unit 153 calculates a straight line L1 which is an approximation line between points p1 to p5. The relationship between the slope shown in the straight line L1 and the concentration is used as calibration curve data 141.

[0046] Here, we have described the case in which the generation unit 153 generates calibration curve data 141, but this is not the only case, and calibration curve data prepared in advance may be received from the input unit 120 or the like and used.

[0047] (effect) Next, the effects of the processing apparatus 100 according to this embodiment will be described. The processing apparatus 100 acquires the absorbance spectrum obtained from the spectrometer 12, and calculates the concentration of the substance to be measured based on the slope when the absorbance spectrum is first differentiated and the calibration curve data 141, thereby enabling accurate calculation of the concentration of the substance to be measured.

[0048] The processing unit 100 performs a DFT on the absorption spectrum and then applies an LPF (low-pass filter) to the DFT result to remove noise from the absorption spectrum acquired by the acquisition unit. This eliminates the effects of scattering by droplets and further improves the accuracy of calculating the concentration of the substance to be measured.

[0049] The processing device 100 normalizes the absorption spectrum to a maximum value of 1 and calculates the concentration of the substance to be measured based on the slope of the first derivative of the normalized absorption spectrum. This minimizes the influence of the amount of droplets attached to the prism and further improves the accuracy of calculating the concentration of the substance to be measured. The amount of droplets attached to the prism is referred to as the "adhesion rate".

[0050] Furthermore, if the concentration of the substance being measured fluctuates significantly over time or due to environmental changes, it can be difficult to create a calibration curve to identify the concentration. In such cases, the calibration curve data 141 can be generated with the prism filled with liquid (full), and the concentration of the substance being measured can be measured using this calibration curve data 141, thereby enabling accurate measurement.

[0051] Figure 9 shows the effect of droplet adhesion rate. In graph G8 of Figure 9, the vertical axis corresponds to absorbance, and the horizontal axis corresponds to wavelength. Curves cu4-1, cu4-2, cu4-3, and cu4-4 show the absorbance spectra for the same concentration but different adhesion rates. The droplet adhesion rate increases in the order of curves cu4-1, cu4-2, cu4-3, and cu4-4. As described above, when the processing device 100 normalizes each curve cu4-1 to cu4-4, the shapes of each absorbance spectrum become almost identical, and the effect of the amount of droplets attached to the prism can be eliminated.

[0052] (Regarding other concentration measurements) Measuring the concentration of granular materials is difficult because the optical path length changes depending on how the granules are mixed, and light intensity decreases due to diffuse reflection, making stable concentration measurement challenging. For example, various methods have been proposed for measuring the concentration of granular materials, including compounding methods such as the KBr tablet method and the Noudour method, methods that measure while mechanically applying pressure, and methods that use two or more different absorption spectra. However, all of these methods presuppose changing the state of the material being measured and are not suitable for in-line measurement. In contrast, the processing device 100 calculates the concentration using the processing procedure described in Figure 3, enabling in-line concentration measurement without changing the state of the material being measured.

[0053] Figure 10 shows a diagram (1) for measuring the concentration of granular material. The example shown in Figure 10 illustrates transmission measurement. Incident light 20a from the light source 20 passes through the granular material and is emitted as emitted light 20b. The emitted light 20b is input to the spectrometer 21.

[0054] For example, the spectrometer 21 measures the absorption spectrum based on the emitted light 20b and outputs the absorption spectrum data to the processing unit 100. The processing unit 100 calculates the concentration of the particles 30 based on the absorption spectrum. The process by which the processing unit 100 calculates the concentration of the particles based on the absorption spectrum is the same as the process of calculating the concentration of a liquid droplet based on the absorption spectrum.

[0055] Figure 11 is a diagram (2) showing the measurement of the concentration of granular material. The example shown in Figure 11 describes the reflection measurement. The incident light 25a from the light source 25 is reflected within the granular material 31 and emitted as emitted light 20b. The emitted light 25b is input to the spectrometer 26.

[0056] For example, the spectrometer 25 measures the absorbance spectrum based on the emitted light 25b and outputs the absorbance spectrum data to the processing unit 100. The processing unit 100 calculates the concentration of the particles 31 based on the absorbance spectrum. The process by which the processing unit 100 calculates the concentration of the particles based on the absorbance spectrum is the same as the process for calculating the concentration of a liquid droplet based on the absorbance spectrum.

[0057] (Hardware) Next, an example of the hardware configuration of the processing unit 100 will be described. Figure 12 is a diagram illustrating an example of the hardware configuration. As shown in Figure 12, the processing unit 100 includes a communication device 6a, an HDD (Hard Disk Drive) 6b, memory 6c, and a processor 6d. Furthermore, each of the parts shown in Figure 12 is interconnected by a bus or the like.

[0058] The communication device 6a communicates with the camera and other external devices. The HDD 6b stores the programs and databases that operate the functions shown in Figure 7.

[0059] The processor 6d reads a program from the HDD 6b or the like that performs the same processing as each processing unit shown in Figure 7 and loads it into memory 6c, thereby operating a process that performs each of the functions described in Figure 7. For example, this process performs the same functions as each processing unit of the processing unit 100. Specifically, the processor 6d executes a process that performs the same processing as the acquisition unit 151, calculation unit 152, generation unit 153, etc.

[0060] Thus, the processing unit 100 operates as a processing unit that performs a method of calculating concentration by reading and executing a program. Furthermore, the processing unit 100 can also achieve the same functionality as the embodiment described above by reading the program from the recording medium using a media reader and executing the read program. It should be noted that the program referred to in these other embodiments is not limited to being executed by the processing unit 100. For example, the present invention can be similarly applied when another computer or server executes the program, or when they collaborate to execute the program.

[0061] This program can be distributed via networks such as the Internet. Furthermore, this program can be recorded on computer-readable storage media such as hard disks, flexible disks (FDs), CD-ROMs, MO (Magneto-Optical disks), and DVDs (Digital Versatile Discs), and executed by reading the program from these media using a computer.

[0062] (others) Some examples of the combinations of technical features that will be disclosed are listed below.

[0063] (1) The processing unit comprises a processor, The aforementioned processor, Obtaining the absorbance spectrum of the droplet to be measured, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope when the absorbance spectrum is first differentiated and the concentration, and the slope when the absorbance spectrum is first differentiated. A processing unit that executes this process.

[0064] (2) The apparatus according to (1), wherein the processor further performs the following actions: remove noise from the absorbance spectrum and calculate the concentration of the object to be measured based on the slope of the first derivative of the noise-removed absorbance spectrum.

[0065] (3) The processing apparatus according to (2), wherein the processor further performs a DFT (Discrete Fourier Transform) on the absorbance spectrum and removes noise from the acquired absorbance spectrum by performing an LPF (Low Pass Filter) on the result of the DFT.

[0066] (4) The apparatus according to (1), (2), or (3), wherein the processor further performs the following actions: normalizing the absorbance spectrum to a maximum value of 1, and calculating the concentration of the object to be measured based on the slope of the first derivative of the normalized absorbance spectrum.

[0067] (5) The processing apparatus according to any one of (1) to (4), wherein the processor further generates calibration curve data based on the slope of the first derivative of absorbance spectra obtained from droplets of different concentrations.

[0068] (6) The processing apparatus according to (5), wherein the processor removes noise from the absorption spectra obtained from droplets of different concentrations, and generates the calibration curve data based on the slope of the first derivative of the noise-removed absorption spectra.

[0069] (7) The processing apparatus according to either (5) or (6), wherein the processor normalizes the maximum value of the absorbance spectra obtained from droplets of different concentrations to 1, and generates the calibration curve data based on the slope of the first derivative of the normalized absorbance spectra.

[0070] (8) The apparatus according to any one of (5) to (7), wherein the processor generates the calibration curve data based on the slope of the first derivative of the absorbance spectra obtained from droplets of water of different concentrations.

[0071] (9) The processing apparatus according to any one of (1) to (8), wherein the processor is a liquid droplet full of water and acquires the absorbance spectrum of the liquid droplet to be measured.

[0072] (10) To the computer, The absorbance spectrum of the droplet to be measured is obtained, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the first derivative of the acquired absorbance spectrum. A program that executes a process.

[0073] (11) A computer The absorbance spectrum of the droplet to be measured is obtained, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the first derivative of the acquired absorbance spectrum. How to execute the process. [Explanation of symbols]

[0074] 100 Processing Units 110 Communications Department 120 Input section 130 Display section 140 Storage section 141 Calibration curve data 150 Control Unit 151 Acquisition Department 152 Calculation Section 153 Generation part

Claims

1. The processing unit includes a processor, The aforementioned processor, Obtaining the absorbance spectrum of the droplet to be measured, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the acquired absorbance spectrum when it is first differentiated. A processing unit that executes this process.

2. The apparatus according to claim 1, further comprising the processor removing noise from the absorption spectrum and calculating the concentration of the object to be measured based on the slope of the first derivative of the noise-removed absorption spectrum.

3. The processing apparatus according to claim 2, further performing a Discrete Fourier Transform (DFT) on the absorbance spectrum and a Low Pass Filter (LPF) on the result of the DFT to remove noise from the acquired absorbance spectrum.

4. The apparatus according to claim 1, further comprising the processor normalizing the maximum value of the absorbance spectrum to 1, and calculating the concentration of the object to be measured based on the slope obtained when the normalized absorbance spectrum is first differentiated.

5. The apparatus according to claim 1, further comprising the processor generating calibration curve data based on the slope of the first derivative of absorbance spectra obtained from droplets of different concentrations.

6. The processing apparatus according to claim 5, wherein the processor removes noise from the absorption spectra obtained from droplets of different concentrations, and generates the calibration curve data based on the slope of the first derivative of the noise-removed absorption spectra.

7. The apparatus according to claim 5, wherein the processor normalizes the maximum value of the absorbance spectra obtained from droplets of different concentrations to 1, and generates the calibration curve data based on the slope of the first derivative of the normalized absorbance spectra.

8. The apparatus according to claim 5, wherein the processor generates the calibration curve data based on the slope of the first derivative of the absorption spectra obtained from droplets of liquid water of different concentrations.

9. The processing apparatus according to claim 1, wherein the processor is a liquid droplet full of water, and the apparatus acquires the absorbance spectrum of the liquid droplet to be measured.

10. On the computer, The absorbance spectrum of the droplet to be measured is obtained, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the first derivative of the acquired absorbance spectrum. A program that executes a process.

11. Computers The absorbance spectrum of the droplet to be measured is obtained, The concentration of the object to be measured is calculated based on calibration curve data showing the relationship between the slope of the first derivative of the absorbance spectrum and the concentration, and the slope of the first derivative of the acquired absorbance spectrum. How to execute the process.

Images