Titration system and program

Abstract

Provided are a versatile titration system, etc., capable of accurately determining an equivalence point. The titration system comprises: a camera that is installed so as to be capable of capturing an image of a flask containing a sample solution; an image generating unit for generating image data representing an image in which the sample solution appears, on the basis of an image signal output from the camera; an operation input unit and a storage unit for storing a plurality of parameter sets each including the type of color value to be determined when determining the equivalence point and a determination criterion corresponding to the type of the color value; a setting unit for reading out from the storage unit a parameter set corresponding to an input signal accepted by the operation input unit, from among the plurality of parameter sets, and setting the type of color value to be determined and the determination criterion on the basis of the parameter set; a pixel value acquiring unit for acquiring a pixel value in a region within the image in which the sample solution appears; a color value acquiring unit for acquiring a color value on the basis of the pixel value acquired by the pixel value acquiring unit; and a determining unit for evaluating the color value on the basis of the determination criterion.

Description

Titration system and program

[0001] The present invention relates to a titration system and a program.

[0002] Known titration methods include a method in which a standard solution containing a titration indicator is dropped into a sample solution and the color of the solution is observed (colorimetric method), and a method in which a standard solution is dropped into a sample solution with an electrode placed therein and the potential difference is measured (potentiometric titration method; see, for example, Patent Document 1).An automatic titration device has also been proposed that detects changes in the color development state of an indicator based on image information from a camera (see, for example, Patent Document 2).

[0003] JP 2010-101724 JP 6-58882

[0004] In the visual colorimetric method, not only is the burden on the operator significant, but the judgment of the equivalence point may vary depending on the operator. On the other hand, in the potentiometric titration method, the electrodes must be cleaned after each titration, making the series of steps required for titration cumbersome.

[0005] In addition, in Patent Document 2, the sample solution is irradiated with a light source of the same or complementary color as the titration indicator, or a filter of the same or complementary color as the titration indicator is provided on the light source, and the endpoint of the titration is detected by a significant change in the brightness of the sample solution. However, since various types of indicators are used in colorimetric titrations, it is difficult to realize a versatile titration system with a configuration in which the light source and filter are changed depending on the type of indicator.

[0006] The present invention has been made in view of the above, and an object of the present invention is to provide a titration system and program that can determine the equivalence point with high accuracy and that are versatile.

[0007] In order to solve the above problems, a titration system according to one aspect of the present invention includes a camera installed so as to be able to photograph a flask containing a sample liquid containing a test substance, and configured to photograph the sample liquid and output an image signal; an image generating unit configured to generate image data representing an image of the sample liquid based on the image signal output from the camera; a memory unit configured to store a plurality of parameter sets including types of color values ​​to be judged when determining an equivalence point according to a combination of a standard solution to which a titration indicator has been added and the test substance, and judgment criteria according to the types of color values; and an operation input unit configured to receive an input signal according to an operation performed from outside. The apparatus includes a setting unit configured to read out from the memory unit a parameter set corresponding to an input signal received by the operation input unit from among the plurality of parameter sets, and set the type of color value to be judged and judgment criteria based on the parameter set; a pixel value acquisition unit configured to acquire pixel values ​​in an area in which the sample liquid is captured within an image generated by the image generation unit; a color value acquisition unit configured to acquire color values ​​of the type set by the setting unit based on the pixel values ​​acquired by the pixel value acquisition unit; and a judgment unit configured to evaluate the color values ​​acquired by the color value acquisition unit based on the judgment criteria set by the setting unit.

[0008] In the titration system, the setting section may be configured to set a plurality of types of color values ​​as the determination target, and to set a relative relationship between the plurality of types of color values ​​as the determination criterion.

[0009] In the titration system, the setting unit may be configured to set one type of color value as the determination target, and to set a threshold value for the one type of color value as the determination criterion.

[0010] In the titration system, the setting unit may be configured to set one type of color value as the determination target, and to set a change in the one type of color value as the determination criterion.

[0011] In the titration system, the setting unit may be further configured to change the type of color value and the judgment criteria that have been set in response to an input signal received by the operation input unit.

[0012] The titration system may further include an area designation unit configured to designate a specific area within the image as an observation area in response to an input signal received by the operation input unit, and the pixel value acquisition unit may be configured to acquire pixel values ​​in the observation area.

[0013] In the above titration system, the memory unit may be configured to further store a measurement file including pixel values ​​acquired by the pixel value acquisition unit and color values ​​acquired by the color value acquisition unit, and may also be configured to further store a hash value of the measurement file.

[0014] Another aspect of the present invention is a program executed by a computer having an operation input unit that receives an input signal in response to an external operation, and a storage unit, wherein the storage unit stores a plurality of parameter sets including types of color values ​​to be judged when determining an equivalence point in response to a combination of a standard solution to which a titration indicator has been added and a test substance, and judgment criteria in response to the types of color values; an image generation step that generates image data representing an image of the sample liquid based on an image signal output from a camera that is installed so as to be able to photograph a flask containing a sample liquid containing the test substance, and that is configured to photograph the sample liquid and output an image signal; and The computer is caused to execute the following steps: a setting step of reading out from the memory unit a parameter set corresponding to the input signal received by the operation input unit from among the set, and setting the type of color value to be judged and judgment criteria based on the parameter set; a pixel value acquisition step of acquiring pixel values ​​in an area in which the sample liquid is captured in the image generated in the image generation step; a color value acquisition step of acquiring color values ​​of the type set in the setting step based on the pixel values ​​acquired in the pixel value acquisition step; and a judgment step of evaluating the color values ​​acquired in the color value acquisition step based on the judgment criteria set in the setting step.

[0015] According to the present invention, it is possible to determine the equivalence point with high accuracy and to realize a versatile titration system.

[0016] 6 is a schematic diagram showing the appearance of a titration system according to an embodiment of the present invention; FIG. 7 is a schematic diagram showing the appearance of the apparatus main body shown in FIG. 1; FIG. 8 is a block diagram showing the general configuration of a titration system according to an embodiment of the present invention; FIG. 9 is a schematic diagram illustrating information stored in a titration method file; FIG. 10 is a flowchart showing the operation of a titration system according to an embodiment of the present invention; FIG. 11 is a schematic diagram illustrating a camera observation screen; FIG. 12 is a schematic diagram illustrating a method selection screen; FIG. 13 is a schematic diagram illustrating a measurement file creation screen; FIG. 14 is a schematic diagram illustrating a method confirmation screen; FIG. 15 is a flowchart showing the titration process of FIG. 6; FIG. 16 is a schematic diagram illustrating a titration screen; FIG. 17 is a schematic diagram illustrating a titration screen; FIG. 18 is a schematic diagram illustrating a measurement file selection screen; FIG. 19 is a schematic diagram illustrating a titration analysis screen; FIG. 19 is a schematic diagram illustrating a graph / image display screen; FIG. 19 is a schematic diagram illustrating a method editing screen; FIG. 20 is a graph showing measurement data in a verification experiment (CMYK color space); FIG. 21 is a graph showing measurement data in a verification experiment (CMY color space); FIG. 22 is a graph showing measurement data in a verification experiment (RGB color space). 1 is a graph (HSV color space) showing measurement data in a verification experiment.

[0017] Hereinafter, a titration system and a program according to embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. In addition, in the description of each drawing, the same parts are denoted by the same reference numerals.

[0018] The drawings referred to in the following description merely show the shapes, sizes, and positional relationships in a schematic manner to enable the understanding of the contents of the present invention. That is, the present invention is not limited to the shapes, sizes, and positional relationships exemplified in each drawing. Furthermore, there may be parts in which the dimensional relationships and ratios differ between the drawings.

[0019] <Configuration of Titration System> Fig. 1 is a schematic diagram showing the appearance of a titration system according to an embodiment of the present invention. The titration system 1 shown in Fig. 1 is a system for detecting a change in color of a sample solution 4a containing a test substance when a standard solution 5a to which a titration indicator (hereinafter also referred to simply as an indicator solution) has been added is dropped into the sample solution 4a, and includes an apparatus main body 2 and an information processing device 3 connected to the apparatus main body 2 in a wired or wireless manner.

[0020] Fig. 2 is a schematic diagram showing the appearance of the device main body 2. As shown in Fig. 2, the device main body 2 has a built-in camera 10 and a light source 20. The camera 10 is installed so as to be able to photograph the flask 4 containing the sample liquid 4a. The light source 20 is, for example, a white surface-emitting LED light, and illuminates the flask 4. In this embodiment, the light source 20 is installed above the camera 10 so as to illuminate the flask 4 from an upward diagonal direction.

[0021] The device main body 2 is provided with a stage mounting section 2a on which a stage 7 for placing a flask 4 is installed.By installing the stage 7 at a predetermined height on this stage mounting section 2a and placing the flask 4 on the stage 7, at least a portion of the flask 4 can be captured within the field of view of the camera 10.

[0022] A stage with a built-in magnetic stirrer may be used as the stage 7. By inserting a stirrer into the flask 4 and operating the stirrer, the sample solution 4a and the standard solution 5a in the flask can be stirred, resulting in a rapid and uniform reaction. A support 6 for holding an electric burette 5 above the flask 4 may also be provided on the stage installation section 2a or the stage 7.

[0023] The electric burette 5 drips the standard solution 5a under the control of the information processing device 3. Of course, instead of the electric burette 5, a manual burette may be used.

[0024] The device main body 2 is provided with a groove-shaped back plate installation portion 2b into which the back plate 8 is fitted. By arranging the back plate 8 on the opposite side of the flask 4 from the camera 10 and light source 20, it is possible to prevent ambient light from entering the camera 10. It is also possible to install the camera 10 and light source 20 separately rather than incorporating them into the device main body 2.

[0025] Fig. 3 is a block diagram showing a schematic configuration of the titration system 1. As shown in Fig. 3, the titration system 1 includes a camera 10 configured to capture an image of the sample solution 4a and output an image signal, and an information processing device 3 configured to acquire the image signal output from the camera 10 and perform various processes to determine the equivalence point in the titration.

[0026] The camera 10 is an imaging device that has an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) and is capable of capturing video at a predetermined frame rate. The imaging element receives light (subject image) that enters the camera 10 and is imaged by an optical system on its light-receiving surface, and generates an electrical signal by photoelectric conversion. The camera 10 generates and outputs an image signal by performing predetermined signal processing on the electrical signal, such as amplification and A / D conversion.

[0027] The information processing device 3 includes an external interface (I / F) 110, a storage unit 120, and a calculation unit 130. The information processing device 3 may also include a display unit 30 and an operation input unit 40.

[0028] The display unit 30 is a display device such as a liquid crystal display, an organic EL display, etc. The operation input unit 40 is an input device such as a keyboard, a mouse, a touch panel, an input button, etc., and inputs a signal corresponding to an operation performed by a user to the calculation unit 130.

[0029] The external interface 110 is an interface for inputting and outputting various signals, such as outputting control signals and inputting image signals, between the external device, such as the camera 10 or the electric burette 5, connected to the information processing device 3. The external interface 110 can adopt various communication standards, such as USB (Universal Serial Bus), Bluetooth (registered trademark), Wi-Fi (Wireless Fidelity), and others.

[0030] The storage unit 120 is configured using, for example, a semiconductor memory such as a ROM or RAM, or a computer-readable storage medium such as a disk drive. The storage unit 120 stores an operating system program, a driver program, programs for causing the calculation unit 130 to execute predetermined operations, and various data and parameters used during the execution of the programs. In detail, the storage unit 120 includes a program storage unit 121 that stores a titration program for determining the equivalence point based on an image captured by the camera 10, a parameter storage unit 122 that stores multiple parameter sets used in determining the equivalence point, a measurement file storage unit 123 that stores a measurement file created for each titration process performed in the titration system 1, and a user information storage unit 124.

[0031] The parameter storage unit 122 stores a plurality of titration method files created for each titration method. The titration method file is a file that stores parameters used when the titration system 1 executes a titration process, and is created for each titration method, such as a basic titration method using phenolphthalein (PP) or an acidic titration method using methyl orange (MO). The parameter storage unit 122 stores a plurality of titration method files related to basic titration methods in advance as initial settings.

[0032] 4 is a schematic diagram illustrating information stored in a titration method file. Each titration method file stores the method title, the target (sample solution), the standard solution, the indicator solution, the initial addition amount, the maximum drip amount, the amount per drip, the drip interval, the drip end condition, and the judgment conditions. The judgment conditions include the type of color value to be judged when determining the equivalence point depending on the combination of the standard solution to which the titration indicator has been added and the test substance, and the judgment criteria corresponding to the type of color value.

[0033] In more detail, when the object of judgment is one type of color value, the judgment criteria may include a threshold value for the color value and a condition for the threshold (e.g., above the threshold, below the threshold, etc.). Furthermore, when the object of judgment is one type of color value, the judgment criteria may set a manner of change in the color value. Examples of judgment criteria include a rapid change in the first derivative (rate of change) of the color value, a change in the sign of the first derivative, or a change in the sign of the second derivative. Alternatively, when the object of judgment is multiple types of color values, the judgment criteria may include the relative relationship between these color values ​​(e.g., the magnitude relationship, ratio, or change in ratio between two types of color values). Furthermore, the judgment criteria may include a value (hereinafter referred to as a selected value) used for judgment among the color values ​​obtained by measurement. Examples of the selected value include a single measurement value, a moving average of multiple measurement values, etc.

[0034] Specifically, color values ​​that can be used in determining the equivalent point in this embodiment include the R value, G value, and B value in the RGB color space, the C value in the CMYK color space, the M value in the CMYK color space, the Y value and K value in the CMYK color space, the C value, M value, and Y value in the CMY color space, the H value, S value, and V value in the HSV color space, and the H value, L value, and S value in the HLS color space. When using these color values, the equivalent point can be determined by comparing them with a preset threshold value.

[0035] Furthermore, combinations of multiple types of color values ​​that can be used to determine the equivalent point include combinations of C and M values, C and Y values, C and K values, M and Y values, M and K values, and Y and K values ​​in the CMYK color space. When using these combinations, the equivalent point can be determined based on the relative relationship between the two types of color values.

[0036] Typical examples of the types of color values ​​to be judged and the judgment criteria are stored in a titration method file pre-stored in the titration system 1. However, the user can arbitrarily change the types of color values ​​and the judgment criteria. In other words, the user can create a desired titration method by arbitrarily changing various items, including the types of color values ​​and the judgment criteria, in the pre-stored titration method file and saving it under a file name.

[0037] The measurement file stored in the measurement file storage unit 123 stores file information including the titration title, the lot number of the sample to be titrated, the sample number, the saved file name, etc., the titration method used in the titration process, image data of the image of the standard solution taken by the camera 10, and measurement data including pixel values ​​in the observation area within the image and color values ​​converted from the pixel values. The measurement data may store color values ​​in all color spaces set in the information processing device 3, or may store only color values ​​in some color spaces. The former has the advantage of speeding up processing when reading out the measurement file and displaying color values ​​in a user-specified color space.

[0038] The user information storage unit 124 stores information (user information) about a user who uses the information processing device 3. The user information includes login information such as a user account and a password, a name, an affiliation, an email address, and access rights to data.

[0039] The calculation unit 130 is configured using hardware such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and loads and executes various programs stored in the program storage unit 121, thereby transferring data and issuing instructions to each unit of the information processing device 3 and comprehensively controlling the operation of the information processing device 3. The calculation unit 130 also loads a titration program to execute a series of titration processes for determining the equivalence point based on images captured by the camera 10. Functional units realized by the calculation unit 130 loading the titration program include an imaging control unit 131, a dropping control unit 132, a display control unit 133, a setting unit 134, an image generation unit 135, a region designation unit 136, a pixel value acquisition unit 137, a color value acquisition unit 138, a determination unit 139, a data management unit 140, and a user information management unit 141.

[0040] The shooting control unit 131 controls the start and end of shooting by the camera 10, and also controls the operation of the camera 10 so that shooting is performed at a predetermined shooting frame rate.

[0041] The drip control unit 132 controls the operation of the electric burette 5. In detail, the drip control unit 132 controls the start and end of dripping, the amount of dripping per drip, the drip interval, etc. of the electric burette 5. The display control unit 133 causes the display unit 30 to display a predetermined titration screen.

[0042] The setting unit 134 selects a titration method from among the plurality of titration methods according to the input signal received by the operation input unit 40, and reads out the titration method file (parameter set) of the selected titration method from the parameter storage unit 122. The setting unit 134 then initializes the judgment conditions for judging the equivalence point based on the information stored in the titration method file. Furthermore, the setting unit 134 changes the initialized judgment conditions to judgment conditions specified by the user according to the input signal received by the operation input unit 40.

[0043] The image generating unit 135 generates image data representing an image of the sample liquid based on the image signal output from the camera 10 .

[0044] The region designation unit 136 designates a specific region in the image showing the sample liquid as an observation region in response to an input signal received by the operation input unit 40 .

[0045] The pixel value acquisition unit 137 acquires pixel values ​​in a region in which the sample liquid appears in the image generated by the image generation unit 135. That is, the pixel value acquisition unit 137 acquires pixel values ​​in an observation region in the image.

[0046] The color value acquisition unit 138 acquires a color value of the type set by the setting unit 134 based on the pixel value acquired by the pixel value acquisition unit 137. In detail, the color value acquisition unit 138 acquires the R value, G value, and B value from the image data related to the observation area, and calculates a color value using these R value, G value, and B value and a predetermined arithmetic expression.

[0047] The determination unit 139 evaluates the color values ​​acquired by the color value acquisition unit 138 based on the determination conditions set by the setting unit 134. Then, when the color values ​​satisfy the determination criteria, it determines that the equivalence point has been reached.

[0048] The data management unit 140 manages various data stored in the measurement file storage unit 123. For example, the data management unit 140 performs processes such as creating a measurement file and storing it in the measurement file storage unit 123 each time a titration process is performed, and searching for and reading out the measurement file stored in the measurement file storage unit 123 in response to an operation on the operation input unit 40.

[0049] Here, when saving a new measurement file, the data management unit 140 may store, in addition to the original measurement file, a hash value obtained by hashing the original measurement file in the measurement file storage unit 123. In this case, when reading and displaying a saved measurement file, the data management unit 140 may hash the measurement file to be read and compare the hash value with the hash value of the original measurement file. As a result, even if the measurement file has been tampered with, it is possible to identify the fact that the measurement file has been tampered with and the tampered part by comparing the hash value of the tampered measurement file with the hash value of the original measurement file.

[0050] The user information management unit 141 manages the user information stored in the user information storage unit 124 based on information input from the operation input unit 40, and also performs password encryption, user authentication, management of access rights to data, etc.

[0051] Regarding passwords, the user information management unit 141 may store only the hash value obtained by hashing the password in the user information storage unit 124. In this case, even if login information is leaked from the information processing device 3, the original password cannot be restored from the hash value, making it possible to prevent unauthorized access to the information processing device 3 by a third party. Furthermore, when hashing a password, the user information management unit 141 may use a salt (an arbitrary character string assigned to the password before hashing) and a pepper (a fixed character string assigned to the password before hashing). In this case, the data management unit 140 may store the pepper in a different layer from the user information, or may store the pepper in a separate storage device connected to the information processing device 3 via wired or wireless communication.

[0052] <Operation of Titration System> First, the information processing device 3 requests the accessing user to input a user account and password, and performs authentication. If the authentication is successful, the titration system 1 starts the following operations related to titration.

[0053] 5 is a flowchart showing the operation of the titration system according to the embodiment of the present invention. First, the titration system 1 causes the camera 10 to start capturing images (step S10). As a result, an image is generated in the information processing device 3 based on image signals sequentially output from the camera 10.

[0054] 6 is a schematic diagram illustrating a camera observation screen displayed on the display unit 30 when the camera 10 starts capturing images. The camera observation screen A1 includes an image display area a11 displaying an image captured by the camera 10, a frame a12 displayed within the image, a size display area a13 indicating the size of the frame a12, a pixel value display area a14 displaying pixel values ​​(R, G, and B values ​​in the RGB color space) within the frame a12, a color value display area a15 displaying values ​​obtained by converting the pixel values ​​into color values ​​in various color spaces (CMYK color space, CMY color space, HSV color space, HLS color space), an update button a16, and an end button a17. The pixel values ​​may be statistical values ​​such as the average or median of the pixel values ​​of each pixel located within the frame a12. The user can change the position and size of the frame a12 in the image display area a11 using the operation input unit 40.

[0055] Next, the titration system 1 specifies an observation area (step S11). Here, when the update button a16 is pressed (e.g., by clicking or tapping; the same applies below), the titration system 1 updates the values ​​in the pixel value display area a14 and the color value display area a15. The user can adjust the position and size of the frame a12 while checking the updated values. Furthermore, when the end button a17 is pressed, the titration system 1 specifies the area surrounded by the frame a12 as the observation area for the series of titration processes.

[0056] Next, the titration system 1 sets parameters (step S12). FIG. 7 is a schematic diagram illustrating a method selection screen displayed on the display unit 30 during parameter setting. The method selection screen A2 includes a method selection area a21, a method detailed information display area a23, and an OK button a24. The method selection area a21 displays the titles of multiple titration method files stored in the parameter storage unit 122. The method detailed information display area a23 displays information about the method on which the cursor a22 is positioned in the method selection area a21, i.e., the name of the selected titration method, the titration target, the standard solution, the indicator solution, and other information. When the OK button a24 is pressed, the titration system 1 reads out a titration method file (parameter set) corresponding to the selected titration method from the storage unit 120 and initializes the parameters. In the following description, it is assumed, as an example, that parameters for the basic titration method (PP) shown in FIG. 4 are set.

[0057] Next, the titration system 1 creates a measurement file (step S13). FIG. 8 is a schematic diagram illustrating a measurement file creation screen. The measurement file creation screen A3 includes a titration method display field a31, a file information input field a32 containing the titration title, the lot number of the sample to be titrated, the sample number, the saved file name, etc., a file name display area a33 displaying the existing file name, and an OK button a34. The titration title is a name representing the titration process to be performed and can be determined by the user. The user can create a new measurement file by entering the necessary information in the file information input field a32. Furthermore, by placing the cursor over one of the file names displayed in the file name display area a33, the file information for that file is reflected in the file information input field a32. The user can also create a new file by modifying the information displayed in the input field a32. When the OK button a34 is pressed with the necessary information entered in the file information input field a32, the titration system 1 creates a new measurement file for the titration method displayed in the titration method display field a31.

[0058] Next, the titration system 1 executes the titration (step S14). FIG. 9 is a schematic diagram illustrating an example of a method confirmation screen. The method confirmation screen A4 includes a display area a41 for the titration method and titration title, a display area a42 for a confirmation message, and an OK button a43. When the OK button a43 is pressed, the titration system 1 starts the titration process. If a stirrer is built into the stage 7 on which the flask 4 is placed, the stirrer may be started at this time. The stirrer may be started under the control of the titration system 1, or may be started by the user manually turning on a switch.

[0059] Fig. 10 is a flowchart showing the titration process of Fig. 5. The titration system 1 first controls the electric burette 5 based on the initial addition amount stored in the titration method file to initially add the standard solution (step S140). Note that if the initial addition amount is not set, step S140 may be omitted.

[0060] 11 is a schematic diagram illustrating a titration screen displayed on the display unit 30 during initial addition. The titration screen A5 includes a measurement file information display area a50, a parameter display area a51 displaying parameters set based on the titration method file, a titration status display area a52 displaying the standard solution drip amount and the elapsed titration time, a color value display area a53 ​​displaying the current color value used to determine the equivalence point, a color space selection area a54 displaying a graph, a color value graph display area a55, an image display area a56, a start button a57, an end button a58, and a comment area a59. The graph display area a55 displays a graph of each color value in a color space (e.g., a CMYK color space) including the initially set color values. By operating the color space selection area a54, the user can display color values ​​in other color spaces (e.g., RGB color space, CMYK color space, CMY color space, HSV color space, HLS color space) in the graph display area a55.

[0061] When the start button a57 is pressed after the initial addition, the titration system 1 starts dripping the standard solution (step S141). FIG. 12 is a schematic diagram illustrating a titration screen displayed on the display unit 30 after dripping of the standard solution has started. A pause button a60 is displayed on the titration screen A5 after dripping has started. The user can interrupt the titration as needed by pressing the pause button a60. Furthermore, the user can force-terminate the titration by pressing the end button a58. Furthermore, the user can enter comments at any time in the comment field a59.

[0062] The titration system 1 acquires pixel values ​​in the observation area in synchronization with the dropping interval of the standard solution (step S142). Specifically, the titration system 1 acquires pixel values ​​(R value, B value, G value) of pixels constituting a specified observation area in the image (see step S11), and calculates statistical values ​​such as the average value and median value of these pixel values.

[0063] Next, the titration system 1 acquires color values ​​to be used for determining the equivalence point based on the acquired pixel values ​​(step S143). For example, when the M value in the CMYK color space is used for determining the equivalence point, the titration system 1 calculates the M value using the R value, G value, and B value acquired in step S142 and a predetermined conversion formula.

[0064] Next, the titration system 1 determines whether the acquired color value satisfies the criteria (step S144). For example, if the criteria are set to "threshold: 0.1, selected value: moving average (5 points), condition: less than or equal to threshold," the titration system 1 calculates the average value of the color values ​​acquired for the four drops prior to this one and the color value acquired this time, and determines whether this average value is less than or equal to the threshold value of 0.1.

[0065] If the color value does not satisfy the criteria (step S145: No), the process returns to step S142. On the other hand, if the color value satisfies the criteria (i.e., if the equivalence point is reached, step S145: Yes), the titration system 1 terminates the dripping of the standard solution (step S146), and then the process returns to the main routine. FIG. 13 is a schematic diagram illustrating a titration screen displayed on the display unit 30 upon completion of dripping of the standard solution. The start button a57 is displayed again on the titration screen A5 shown in FIG. 13. The titration system 1 stops dripping of the standard solution when it determines that the color value satisfies the criteria. However, the dripping may be restarted when the start button a57 is pressed. That is, the dripping can be resumed at the user's discretion. Furthermore, if a specific dripping termination condition is set in the titration method file, the titration system 1 controls the end of dripping in accordance with that dripping termination condition.

[0066] 5 again, after the titration is completed, the titration system 1 saves the titration results (step S15). Specifically, the color value data in each space acquired each time the standard solution is dropped from the start to the end of the dropping is stored in a measurement file together with the image data, and is stored in the measurement file storage unit 123. At this time, a hash value obtained by hashing the measurement file may also be stored in the measurement file storage unit 123. Thereafter, the titration process in the titration system 1 is completed.

[0067] <Analysis of Titration Results> In the titration system 1, the user can also analyze titration results after the fact using the saved measurement file. Fig. 14 is a schematic diagram illustrating an example of a measurement file selection screen. The file selection screen A6 includes a search item selection area a61, a display area a62 for titration titles extracted by the search, a data selection area a63, a detailed information display area a64, and an OK button a65.

[0068] Measurement files can be searched not only by titration title, but also by titration method, user name (operator), operation date, lot number, sample number, and comment. The data selection area a63 displays a list of measurement file names related to the titration title where the cursor a66 is placed in the display area a62. The detailed information display area a64 displays detailed information related to the measurement file where the cursor a67 is placed in the data selection area a63. When the OK button a65 is pressed with a measurement file name selected in the data selection area a63, the titration system 1 reads the selected measurement file from the measurement file storage unit 123 and displays it on the display unit 30.

[0069] At this time, the titration system 1 may hash the selected measurement file and compare the hash value with the hash value of the original measurement file stored in the measurement file storage unit 123. If a difference is found between the two hash values ​​as a result, the titration system 1 may display a warning on the display unit 30 that the measurement file may have been tampered with.

[0070] 15 is a schematic diagram illustrating a titration analysis screen. The titration analysis screen A7 includes a detailed information display area a71 that displays the titration method, file name, various parameters, etc., of the measurement file read from the measurement file storage unit 123, a measurement data display area a72, a graph / image display button a73, a reanalysis button a74, an analysis method selection area a75, and a save button a76. The measurement data display area a72 may display pixel values ​​acquired during the titration process and color values ​​set as judgment conditions, as well as various color values ​​that can be acquired by the titration system 1.

[0071] In the analysis method selection area a75, the user can select the color value, threshold value, selection value, and conditions for determining the equivalence point. When the analysis method selection area a75 is operated and the reanalysis button a74 is pressed, the titration system 1 reanalyzes the equivalence point using the changed determination conditions. When the save button a76 is pressed, the titration system 1 saves a new file containing the changed content.

[0072] Furthermore, when the graph / image display button a73 is pressed, the titration system 1 displays a graph / image display screen A8, as shown in Fig. 16, on the display unit 30. The graph / image display screen A8 includes an image display area a80 in which an image captured by the camera 10 is displayed, a graph display area a81 in which a graph of color values ​​is displayed, a color value selection area a82, and a graph update button a83.

[0073] The user can select the type of color value to be used for determining the equivalence point by checking the checkboxes of the color values ​​in various color spaces displayed in the color value selection area a82. When any checkbox is checked and the graph update button a83 is pressed, the titration system 1 displays a graph of the checked color values ​​in the graph display area a81.

[0074] A frame a84 representing the observation area is displayed in the image display area a80. The user can change the position and size of this frame a84 using the operation input unit 40. When the frame a84 is changed, the titration system 1 may acquire the pixel values ​​of each pixel in the changed frame a84 and recalculate the color values ​​in the measurement data display area a72 (see FIG. 15 ).

[0075] <Editing a Titration Method> In the titration system 1, a user can create a new titration method by editing an existing titration method. Fig. 17 is a schematic diagram illustrating an example of a method editing screen. The method editing screen A9 is provided with a method name input field a91, a method editing area a92, an analysis method editing area a93, and a new save button a94.

[0076] When the name of a titration method is entered in the method name input field a91, the titration system 1 reads the corresponding titration method file from the parameter storage unit 122 and displays the parameters of the titration target (sample solution), standard solution, and indicator solution, as well as the maximum drop volume, initial addition volume, titration end setting, single drop volume, and drop interval in the method editing area a92. The titration system 1 also displays the equivalence point determination conditions (color value type, selected value, threshold, and conditions) in the analysis method editing area a93. The user can change the content displayed in the method editing area a92 and the analysis method editing area a93. The user can change the content by selecting the desired content from a drop-down list provided for each item or by entering the desired content as text. When the user presses the New Save button a94, the titration system 1 creates a new titration method file containing the edited content of the titration method and stores it in the parameter storage unit 122. As a result, the file name of the newly created titration method file is displayed on the method selection screen A2 illustrated in FIG. 7.

[0077] As described above, according to this embodiment, the equivalence point can be determined using appropriate color values ​​and judgment criteria depending on the combination of the test substance and the standard solution to which the titration indicator has been added, thereby enabling accurate titration. Furthermore, since multiple parameter sets are stored in advance in the storage unit depending on the combination of the test substance and the standard solution to which the titration indicator has been added, a versatile titration system can be realized.

[0078] Furthermore, according to this embodiment, in each titration method, appropriate color values ​​and judgment criteria for determining the equivalence point are pre-initialized depending on the combination of the standard solution to which the titration indicator has been added and the test substance, so that even users who are unfamiliar with titration can easily and accurately determine the equivalence point.

[0079] Furthermore, according to this embodiment, the user can change the initially set color value type and judgment criteria by operating the operation input unit, so that the equivalent point can be judged based on the desired color value type and judgment.

[0080] Furthermore, according to this embodiment, a specific area within an image can be designated as an observation area in accordance with an input signal received by the operation input unit, allowing the user to set an appropriate observation area at their discretion.

[0081] Furthermore, according to this embodiment, in addition to the original measurement file storing the titration measurement data, the hash value of the measurement file is stored, so that if the original measurement file is tampered with, it is possible to identify the fact and the tampered part.

[0082] (Verification Experiment) A titration test was carried out to measure the amino acid content of sake using the titration system 1 according to this embodiment. The measurement method followed the National Research Institute of Brewing's Standard Analysis Method 3-6 Amino Acid B) Measurement of Amino Acid Content by Ethanol Addition Method (reference: https: / / www.nta.go.jp / taxes / sake / sonota / sokuteihoho / pdf / 10.pdf).

[0083] Here, the measurement of amino acid content by the ethanol addition method is carried out as follows: Sample solution: sake (refined sake) Indicator: phenolphthalein indicator (0.5 g of phenolphthalein dissolved in 50 mL of ethanol) Standard solution: 0.1 mol / L (N / 10) sodium hydroxide solution Ethanol: ethanol (99.5) (special grade) (according to the provisions of JIS K8101:2006)

[0084] Step 1: Add a few drops of phenolphthalein indicator to 10 mL of sample. Step 2: Neutralize the solution from step 1 by adding N / 10 sodium hydroxide solution until it turns pale pink. Step 3: Add 25 mL of ethanol to the solution from step 2 to return it to colorless. Step 4: Add N / 10 sodium hydroxide solution to the solution from step 3 until it turns pale pink again, and titrate. Then, determine the titration value "a" at the endpoint. Step 5: Using the titer F, determine the amino acid degree by multiplying a by F (rounded to two decimal places).

[0085] In step 4, 50 μL of a standard solution (N / 10 sodium hydroxide solution) was added at a time. Then, while acquiring measurement data using the titration system 1, the endpoint was visually determined. The titration volume at the endpoint determined visually was 1.05 mL. The change in color value in various color spaces relative to this titration volume was examined.

[0086] 18 to 21 are graphs showing measurement data from the verification experiment. In Fig. 18 to Fig. 21, the horizontal axis shows the amount of standard solution dispensed after the addition of ethanol (step 3). On the vertical axis, Fig. 18 shows color values ​​in the CMYK color space, Fig. 19 shows color values ​​in the CMY color space, Fig. 20 shows color values ​​in the RGB color space, and Fig. 21 shows color values ​​in the HSV color space.

[0087] In the case of the CMYK color space (see Figure 18), no significant change in the color values ​​was observed even at the end point (1.05 μL). This is thought to be because, in this experiment, turbidity occurred when the standard solution was dropped, causing the color values ​​to change slowly. In contrast, in the case of the CMY color space (see Figure 19), a steep change in the M value was observed near the end point. The M value at the end point was 0.525.

[0088] In the RGB color space (see FIG. 20), the R, G, and B values ​​all tended to decrease before the end point, but the R value began to increase when the end point was reached. On the other hand, in the HSV color space (see FIG. 21), there were no significant changes in the H, S, or V values ​​when the end point was reached, and the H value suddenly decreased when the next drop after the end point (1.05 μL) was dispensed.

[0089] From the above experimental results, it was found that it is appropriate to determine the endpoint in the CMY color space when measuring the amino acid content using the ethanol addition method. That is, in the CMY color space, the M value becomes steep near the endpoint, so by setting a threshold value for the M value (e.g., 0.525), it is possible to clearly determine whether the threshold value has been exceeded each time the standard solution is dropped.

[0090] The present invention is not limited to the above-described embodiments and modifications, and can be embodied in various other forms without departing from the spirit of the present invention. For example, some components may be removed from all of the components shown in the embodiments and modifications, or the components shown in the above-described embodiments and modifications may be appropriately combined.

[0091] 1...Titration system, 2...Apparatus main body, 2a...Stage installation section, 2b...Back panel installation section, 3...Information processing device, 4...Flask, 4a...Sample solution, 5...Motorized burette, 5a...Standard solution, 6...Support section, 7...Stage, 8...Back panel, 10...Camera, 20...Light source, 30...Display section, 40...Operation input section, 110...External interface, 120...Memory section, 121...Program memory section, 122...Parameter memory section, 123...Measurement file memory section, 124...User information memory section, 130...Calculation section, 131...Photography control section, 132...Dropping control section, 133...Display control section, 134...Setting section, 135...Image generation section, 136...Area designation section, 137...Pixel value acquisition section, 138...Color value acquisition section, 139...Determination section, 140...Data management section, 141...User information management section

Claims

1. A camera installed so as to be able to photograph a flask containing a sample liquid containing a test substance, and configured to photograph the sample liquid and output an image signal; an image generating unit configured to generate image data representing an image of the sample liquid based on the image signal output from the camera; a memory unit configured to store a plurality of parameter sets including a type of color value to be judged when determining an equivalence point and a judgment criterion corresponding to the type of color value, depending on a combination of a standard solution to which a titration indicator has been added and the test substance; an operation input unit configured to receive an input signal corresponding to an operation performed from the outside; a setting unit configured to read out from the memory unit a parameter set corresponding to the input signal received by the operation input unit from among the plurality of parameter sets, and set the type of color value to be judged and the judgment criterion based on the parameter set; a pixel value acquiring unit configured to acquire pixel values ​​in an area in which the sample liquid is captured within the image generated by the image generating unit; and a color value acquiring unit configured to acquire the type of color value set by the setting unit, based on the pixel values ​​acquired by the pixel value acquiring unit. a determination unit configured to evaluate the color value acquired by the color value acquisition unit based on a determination criterion set by the setting unit.

2. The titration system according to claim 1, wherein the setting unit is configured to set multiple types of color values ​​as the objects of judgment and to set the relative relationships of the multiple types of color values ​​as the judgment criteria.

3. The titration system according to claim 1, wherein the setting unit is configured to set one type of color value as the object of judgment and to set a threshold value of the one type of color value as the judgment criterion.

4. The titration system according to claim 1, wherein the setting unit is configured to set one type of color value as the subject of judgment and to set the manner of change in the one type of color value as the judgment criterion.

5. A titration system according to any one of claims 1 to 4, wherein the setting unit is further configured to change the type of color value and the judgment criteria set in response to an input signal received by the operation input unit.

6. A titration system as described in any one of claims 1 to 5, further comprising an area designation unit configured to designate a specific area within the image as an observation area in response to an input signal received by the operation input unit, and the pixel value acquisition unit is configured to acquire pixel values ​​in the observation area.

7. A titration system described in any one of claims 1 to 6, wherein the memory unit is further configured to store a measurement file including pixel values ​​acquired by the pixel value acquisition unit and color values ​​acquired by the color value acquisition unit, and is further configured to store a hash value of the measurement file.

8. A program to be executed by a computer having an operation input unit that receives an input signal corresponding to an external operation and a storage unit, wherein the storage unit stores a plurality of parameter sets including a type of color value to be judged when determining an equivalence point according to a combination of a standard solution to which a titration indicator has been added and a test substance, and a judgment criterion corresponding to the type of color value; an image generating step of generating image data representing an image of the sample liquid based on an image signal output from a camera that is installed so as to be able to photograph a flask containing a sample liquid containing the test substance and is configured to photograph the sample liquid and output an image signal; a setting step of reading from the storage unit a parameter set corresponding to the input signal received by the operation input unit from among the plurality of parameter sets, and setting the type of color value to be judged and the judgment criterion based on the parameter set; a pixel value acquiring step of acquiring pixel values ​​in an area in which the sample liquid is photographed within the image generated in the image generating step; and a color value acquiring step of acquiring the type of color value set in the setting step based on the pixel values ​​acquired in the pixel value acquiring step. a determination step of evaluating the color value acquired in the color value acquisition step based on the determination criterion set in the setting step.

Images