Measuring device, measuring method, and program

Abstract

A measuring device, according to the present invention, is configured by comprising: a fluorescence amount measuring unit that causes excitation light to be irradiated from an excitation light source at an excitation light level selected from among a plurality of predetermined excitation light levels, and measures the fluorescence amount, which is emitted according to the amount of a target to be measured in a sample introduced into a test specimen that has received the irradiated excitation light; a concentration converting unit that, from fluorescence amount-concentration relationship information indicating the relationship between the fluorescence amount and the concentration of the target to be measured in the sample under conditions where excitation light is irradiated at each of the plurality of predetermined excitation light levels, acquires the fluorescence amount-concentration relationship information corresponding to the selected excitation light level, and on the basis of the acquired fluorescence amount-concentration relationship information, converts the fluorescence amount measured by the fluorescence amount measuring unit into the concentration of the target to be measured in the sample introduced into the test specimen that has received the excitation light; and a validity determining unit that determines whether the concentration obtained by the concentration converting unit is valid.

Description

Measurement device, measurement method, and program

[0001] This application claims priority to Japanese Patent Application No. 2024-148293, filed on August 30, 2024, the contents of which are incorporated herein by reference.

[0002] Measurement devices based on the principle of fluorescence measurement are known, and for example, a technology is known that corresponds to immunochromatography, in which the distance from an irradiation unit to a development layer in which a sample is developed is measured based on the reflected light of measurement light irradiated from the irradiation unit onto the development layer in which the sample is developed, and the position of the irradiation unit is adjusted according to the measured distance, thereby focusing the fluorescence measurement unit (see, for example, Patent Document 1).

[0003] JP 2013-238543 A

[0004] When using a measuring device based on the principle of fluorescence measurement, there is a large variation in the concentration of the analyte contained in the sample that is the subject of fluorescence measurement. Therefore, in fluorescence measurement, when the concentration of the analyte contained in the sample is low, the measured value obtained as the measurement result will be smaller than the range that can be converted to a valid concentration, and when the concentration of the analyte contained in the sample is high, the measured value obtained will exceed the range that can be converted to a valid concentration, and so on, and normal measurement results may not be obtained.

[0005] An object of the present invention is to solve the above problem by expanding the measurable range of the measurement target substance in a specimen in fluorescence measurement.

[0006] One aspect of the present invention that solves the above-mentioned problems is a measurement device that includes a fluorescence amount measurement unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source and measures the amount of fluorescence emitted in accordance with the amount of the object to be measured in a specimen introduced into the test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the fluorescence amount under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the object to be measured in the specimen, and converts the fluorescence amount measured by the fluorescence amount measurement unit into the concentration of the object to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

[0007] One aspect of the present invention is a measurement method for a measurement device, the measurement method including: a fluorescence amount measurement step in which a fluorescence amount measurement unit irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source, and measures the amount of fluorescence emitted in accordance with the amount of a substance to be measured in a specimen introduced into the test piece that has received the irradiated excitation light; a concentration conversion step in which a concentration conversion unit acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the amount of fluorescence under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the fluorescence amount measured in the fluorescence amount measurement step into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination step in which a validity determination unit determines whether the concentration obtained in the concentration conversion step is valid.

[0008] One aspect of the present invention is a program for causing a computer serving as a measurement device to function as: a fluorescence quantity measurement unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source and measures the quantity of fluorescence emitted in accordance with the quantity of the substance to be measured in a specimen introduced into a test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence quantity-concentration relationship information corresponding to the selected excitation light level from fluorescence quantity-concentration relationship information that indicates the relationship between the fluorescence quantity under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the fluorescence quantity measured by the fluorescence quantity measurement unit into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence quantity-concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

[0009] According to the present invention, the range of concentrations of the object to be measured in a specimen that can be measured by fluorescence can be expanded.

[0010] FIG. 1 is a diagram illustrating an example of the functional configuration of a measurement device in a first embodiment. FIG. 2 is a diagram explaining an example of creating a calibration curve in the first embodiment. FIG. 3 is a diagram illustrating an example of determining the effectiveness of the concentration of a target substance to be measured in a specimen in the first embodiment. FIG. 4 is a diagram illustrating a specific example of measurement results in the first embodiment. FIG. 5 is a flowchart illustrating an example of a process procedure executed by a measurement device in the first embodiment in association with creating a calibration curve. FIG. 6 is a diagram illustrating an example of a process procedure executed by a measurement device in the first embodiment in association with measuring the concentration of a target substance to be measured using one test object. FIG. 7 is a diagram illustrating an example of a process procedure executed by a measurement device in the second embodiment in association with measuring the concentration of a target substance to be measured using one test object. FIG. 8 is a diagram illustrating an example of a process procedure executed by a measurement device in the third embodiment in association with measuring the concentration of a target substance to be measured using one test object. FIG. 9 is a diagram illustrating an example of the hardware configuration of measurement devices in the first to third embodiments.

[0011] First Embodiment A measurement device according to this embodiment will be described below. The measurement device according to this embodiment is a device that measures the concentration of a target substance from the amount of fluorescence generated in response to the amount of the target substance in a specimen introduced into the specimen by irradiating the specimen with excitation light.

[0012] 1 shows an example of the functional configuration of measurement device 100. Measurement device 100 may be configured with hardware such as a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and storage devices such as hard disk drives (HDDs) and solid state drives (SSDs). The functions of measurement device 100 shown in the figure are realized by the CPU provided in measurement device 100 executing a program.

[0013] The measuring device 100 in the figure includes an input / output unit 101, a user interface unit 102, an excitation light source 103, a light receiving unit 104, a control unit 105, and a storage unit 106.

[0014] The input / output unit 101 has a data interface and a network communication function, and thereby inputs and outputs information to and from external devices, other devices having communication functions, servers, and the like.

[0015] The user interface unit 102 includes controls and input devices operated by the operator of the measuring device 100, and accepts user operations on the measuring device 100. The user interface unit 102 also includes a display unit, an audio output unit, etc., and provides information to the user by displaying or outputting audio, etc. The user interface unit 102 may also include a printer that prints out information such as measurement results.

[0016] The excitation light source 103 is a component provided to irradiate the test piece 200, which is placed at a predetermined position in the measurement device 100, with excitation light. A mixture of a reagent and a specimen, or a specimen, is introduced into the test piece 200. The test piece 200 may have a cartridge-type structure. When irradiated with excitation light, the test piece 200 generates an amount of light (fluorescence amount) due to fluorescence that corresponds to the amount of the substance to be measured in the introduced specimen.

[0017] The light receiving unit 104 outputs a light intensity signal corresponding to the amount of fluorescence generated in the test piece 200 .

[0018] The control unit 105 executes various controls in the measurement device 100. The control unit 105 includes a fluorescence amount measurement unit 151, a concentration conversion unit 152, a validity determination unit 153, a measurement result information output unit 154, and a calibration curve creation unit 155.

[0019] The fluorescence amount measurement unit 151 selects one excitation light level from a plurality of predetermined excitation light levels, and irradiates the specimen introduced into the test piece 200 with excitation light from the excitation light source 103 at the selected excitation light level. The test piece 200 emits fluorescence in response to the irradiated excitation light. The fluorescence amount measurement unit 151 measures the amount of fluorescence generated in response to the measurement target in the specimen, based on the light amount signal output from the light receiving unit 104 in response to the amount of fluorescence from the specimen.

[0020] The concentration conversion unit 152 acquires, from the calibration curve storage unit 161, a calibration curve (an example of fluorescence amount-concentration relationship information) that has been created in advance in accordance with the excitation light level selected by the fluorescence amount measurement unit 151 when measuring the fluorescence amount. The concentration conversion unit 152 uses the acquired calibration curve to convert the fluorescence amount measured by the fluorescence amount measurement unit 151 into the concentration of the specimen. The concentration thus acquired by the concentration conversion unit 152 indicates the concentration of the analyte in the specimen that was introduced into the test piece 200 irradiated with excitation light.

[0021] A valid range (effective range) is defined for the value of the concentration of the analyte in the sample obtained by the concentration conversion unit 152. The validity determination unit 153 determines whether the concentration obtained by the concentration conversion unit 152 is valid as a measurement value.

[0022] The measurement result information output unit 154 outputs measurement result information indicating the measurement results.

[0023] The calibration curve creating unit 155 creates a calibration curve to be stored in the calibration curve storage unit 161 .

[0024] The storage unit 106 stores various types of information corresponding to the measurement device 100. The storage unit 106 includes a calibration curve storage unit 161. The calibration curve storage unit 161 stores calibration curves that are created in advance for each of a plurality of predetermined excitation light levels.

[0025] 2, an example of creating a calibration curve according to the excitation light level by the calibration curve creation unit 155 will be described. Here, an example will be given in which there are three predetermined excitation light levels (excitation light levels 1, 2, and 3) as options for the fluorescence amount measurement unit 151.

[0026] 2(A), 2(B), and 2(C) show calibration curves cv-1, cv-2, and cv-3 created corresponding to excitation light levels 1, 2, and 3, respectively. The excitation light levels increase in the order of excitation light level 1, excitation light level 2, and excitation light level 3, with excitation light level 1 being the smallest and excitation light level 3 being the largest. In these figures, three calibrators cal-B, cal-1, and cal-2, which are common to excitation light levels 1, 2, and 3, are prepared to create the calibration curves cv-1, cv-2, and cv-3, respectively. The concentrations of the calibrators cal-B, cal-1, and cal-2 are known. The concentration values ​​increase in the order of the calibrators cal-B, cal-1, and cal-2.

[0027] 2A is created, for example, as follows. The calibration curve creation unit 155 causes the fluorescence amount measurement unit 151 to irradiate the calibrator cal-B with excitation light at excitation light level 1, thereby measuring the amount of fluorescence generated in the calibrator cal-B according to the state of fluorescence. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to irradiate the calibrator cal-1 with excitation light at excitation light level 1, thereby measuring the amount of fluorescence generated in the calibrator cal-1 according to the state of fluorescence. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to irradiate the calibrator cal-2 with excitation light at excitation light level 1, thereby measuring the amount of fluorescence generated in the calibrator cal-2 according to the state of fluorescence.

[0028] The calibration curve creation unit 155 plots coordinates of the amount of fluorescence (photometric amount) measured for calibrator cal-B and the known concentration of calibrator cal-B. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for calibrator cal-1 and the known concentration of calibrator cal-1. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for calibrator cal-2 and the known concentration of calibrator cal-2. Based on the three coordinates plotted as described above, the calibration curve creation unit 155 creates a calibration curve cv-1 that shows the relationship between concentration and amount of fluorescence under the condition of excitation light level 1. In this case, the calibration curve creation unit 155 may obtain the calibration curve cv-1 using, for example, the least squares method.

[0029] For example, a measurement value of the amount of fluorescence is considered valid within the range from the lower measurement limit Mmin to the upper measurement limit Mmax (effective range). A fluorescence amount below the lower measurement limit Mmin is so small as a measurement that the converted concentration value may be less accurate. Furthermore, a fluorescence amount that reaches the upper measurement limit Mmax is saturated, making it impossible to obtain an appropriate concentration value. Therefore, a concentration converted from a fluorescence amount is also considered invalid if the corresponding fluorescence amount is outside the effective range.

[0030] 2B, the calibration curve cv-2 is obtained by causing the calibration curve creation unit 155 to cause the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-B by irradiating the calibrator cal-B with excitation light at excitation light level 2. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-1 by irradiating the calibrator cal-1 with excitation light at excitation light level 2. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-2 by irradiating the calibrator cal-2 with excitation light at excitation light level 2.

[0031] The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-B and the known concentration of the calibrator cal-B. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-1 and the known concentration of the calibrator cal-1. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-2 and the known concentration of the calibrator cal-2. Based on the three coordinates plotted as described above, the calibration curve creation unit 155 creates a calibration curve cv-2 that shows the relationship between concentration and amount of fluorescence under the condition of excitation light level 2.

[0032] 2C, the calibration curve cv-3 is obtained by causing the calibration curve creation unit 155 to cause the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-B by irradiating the calibrator cal-B with excitation light at excitation light level 3. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-1 by irradiating the calibrator cal-1 with excitation light at excitation light level 3. The calibration curve creation unit 155 also causes the fluorescence amount measurement unit 151 to measure the amount of fluorescence corresponding to the fluorescent state generated in the calibrator cal-2 by irradiating the calibrator cal-2 with excitation light at excitation light level 3.

[0033] The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-B and the known concentration of the calibrator cal-B. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-1 and the known concentration of the calibrator cal-1. The calibration curve creation unit 155 plots coordinates of the amount of fluorescence measured for the calibrator cal-2 and the known concentration of the calibrator cal-2. Based on the three coordinates plotted as described above, the calibration curve creation unit 155 creates a calibration curve cv-3 that shows the relationship between concentration and amount of fluorescence under the condition of excitation light level 3.

[0034] The calibration curve creating unit 155 stores the created calibration curves cv-1, cv-2, and cv-3 in the calibration curve storage unit 161 in association with excitation light levels 1, 2, and 3, respectively.

[0035] The calibration curve creation unit 155 may create a set of calibration curves corresponding to each of a plurality of predetermined excitation light levels for each measurement object. Furthermore, measurements of a plurality of measurement items may be performed for a single test specimen. In this case, the calibration curve creation unit 155 may create a set of calibration curves using the results of actual measurements using a carburetor for a specific measurement item, and then create sets of calibration curves corresponding to other measurement items by calculation using the measured values ​​actually measured for the specific measurement item. As a specific example, the calibration curve creation unit 155 may multiply the measured values ​​actually measured for a specific measurement item by coefficients determined for the other measurement items, and then create sets of calibration curves corresponding to the other measurement items using the measured values ​​after multiplication.

[0036] The example of creating a calibration curve shown in Figure 2 is merely an example. For example, the number of calibrators with known concentrations used to create the calibration curve is not limited to three, and any multiple number may be used. In this case, the concentrations of the multiple calibrators do not need to be spaced at regular intervals, and may be determined appropriately in consideration of creating a highly accurate calibration curve. Furthermore, the number of calibration curves to be created (i.e., the number of excitation light level levels used in measurement) is not limited to three, and any multiple excitation light levels may be determined.

[0037] The calibration curve storage unit 161 may store a calibration curve created by, for example, another creation device. Alternatively, the calibration curve storage unit 161 may import the measurement results of the calibrator for each excitation light level by a certain measurement device into an information processing device such as a personal computer, and store the calibration curve created by the information processing device.

[0038] Furthermore, the calibration curve may be created by placing a calibration-dedicated test object equipped with a calibrator for creating the calibration curve in the measurement device 100 and measuring the amount of fluorescence. Alternatively, an inner calibrator for creating the calibration curve may be provided in the measurement test object 200, and the calibration curve may be created using the amount of fluorescence measured using the inner calibrator. Alternatively, a calibrator for creating the calibration curve may be placed in the measurement device 100, and the calibration curve may be created using the amount of fluorescence measured in the measurement device 100 using the calibrator.

[0039] Although the calibration curve created in FIG. 2 is an example of a straight line based on a linear function, a curved calibration curve may also be created.

[0040] FIG. 3 shows example concentration measurement results for three specimens, sm-1, sm-2, and sm-3, performed at excitation light levels 1, 2, and 3. FIG. 3A shows the relationship between the fluorescence intensity and the concentration of the analyte in each specimen (analyte concentration) obtained for each specimen, sm-1, sm-2, and sm-3, when irradiated with excitation light at excitation light level 1. In this case, by applying the calibration curve cv-1 to the fluorescence intensity measured for each of the three specimens, sm-1, sm-2, and sm-3, the analyte concentration converted from each fluorescence intensity can be obtained. In the example of FIG. 3A, the measured fluorescence intensity for specimen sm-1 is less than the lower measurement limit Mmin. Therefore, the concentration converted from the fluorescence intensity for specimen sm-1 is invalid as a measured value. For specimens sm-2 and sm-3, the measured fluorescence intensity was within the valid range, and therefore the corresponding concentrations were also determined to be valid as measured values. The amount of fluorescence outside the effective range may also be converted into a density, and then the density converted from the amount of fluorescence within the effective range may be compared with the density converted from the amount of fluorescence outside the effective range to determine whether the density converted from the amount of fluorescence within the effective range is correct.

[0041] FIG. 3B shows the relationship between the amount of fluorescence obtained for each of three specimens sm-1, sm-2, and sm-3 and the concentration of the analyte in the specimen when irradiated with excitation light at excitation light level 2. In this case, by applying calibration curve cv-2 to the amount of fluorescence measured for each of the three specimens sm-1, sm-2, and sm-3, the concentration of the analyte converted from each amount of fluorescence is obtained. In the example of FIG. 3B, the measured amounts of fluorescence for specimens sm-1 and sm-2 were within the valid range, so both concentrations were determined to be valid as measured values. For specimen sm-3, the measured amount of fluorescence reached the upper measurement limit Mmax, resulting in a saturated state, and therefore the concentration was determined to be invalid as measured value.

[0042] Figure 3(C) shows the relationship between the fluorescence amount and the concentration of each of the three specimens sm-1, sm-2, and sm-3 when irradiated with excitation light at excitation light level 3. In this case, by applying calibration curve cv-3 to the fluorescence amount measured for each of the three specimens sm-1, sm-2, and sm-3, a concentration converted from each fluorescence amount can be obtained. In the example of Figure 3(C), the measured fluorescence amount for specimen sm-1 is within the valid range, so the concentration is determined to be valid as a measured value. For specimens sm-2 and sm-3, the measured fluorescence amount is saturated, reaching the upper measurement limit Mmax, so the concentration is determined to be invalid as a measured value.

[0043] As can be seen from Figures 3(A), 3(B), and 3(C), when measurements are performed using a certain excitation light level, appropriate measurement results may not be obtained for samples in which the analyte concentration is below a certain level or above a certain level. Specifically, when the excitation light level is low, valid measurement results cannot be obtained for samples in which the analyte concentration is low. Furthermore, when the excitation light level is high, valid measurement results cannot be obtained for samples in which the analyte concentration is high. Therefore, for samples in which the analyte concentration is low, valid measurement results can be expected by performing measurements using a high excitation light level. Furthermore, for samples in which the analyte concentration is high, valid measurement results can be expected by performing measurements using a low excitation light level.

[0044] Therefore, in the measuring apparatus 100 of this embodiment, when performing fluorescence measurement on one test object 200, the fluorescence amount measurement unit 151 sequentially selects from a plurality of predetermined excitation light levels, from lowest to highest, and causes the excitation light source 103 to irradiate excitation light at the selected excitation light level. The fluorescence amount measurement unit 151 measures the fluorescence amount for each excitation light level, and the concentration conversion unit 152 converts the measured fluorescence amount into a concentration. In this manner, the measuring apparatus 100 obtains concentration measurement results for each excitation light level corresponding to one test object 200. The validity determination unit 153 then determines whether the concentration for each excitation light level obtained by the concentration conversion unit 152 is valid as a measurement result. The measurement result information output unit 154 may display measurement result information indicating the measurement result determined to be valid by the validity determination unit 153 on the display unit of the user interface unit 102, print it using a printer in the user interface unit 102, or the like.

[0045] 4A and 4B show specific examples of the results of measuring the concentration of a different specimen 200 using the measuring device 100 of this embodiment while sequentially selecting the excitation light level as described above. These figures show an example in which eight levels of excitation light, from level 1 to level 8, are predetermined.

[0046] FIG. 4A shows an example of fluorescence measurement performed on a test object 200 containing a specimen containing a low concentration of the analyte (0.05 ng / ml). The figure shows the fluorescence amount measured at each excitation light level, as the fluorescence amount measurement unit 151 irradiates the test object 200 with excitation light from the excitation light source 103 while switching the excitation light level from level 1 to level 8. The figure also shows the calibration curves used by the fluorescence amount measurement unit 151 to convert the measured fluorescence amount to a concentration. Specifically, the figure shows that calibration curves 1 to 8 are applied corresponding to the excitation light levels from level 1 to level 8. The figure first shows that the fluorescence amount measured at each excitation light level from level 1 to level 5 was below the lower measurement limit Mmin, and therefore the converted concentration (denoted as "converted concentration" in the figure) is invalid. The result shows that the amount of fluorescence measured at the sixth excitation light level was within the valid range, and the converted concentration value (0.05 ng / ml) was also considered valid. The result also shows that the amount of fluorescence measured at the sixth and seventh excitation light levels was within the valid range, and the converted concentration value (0.05 ng / ml) was also considered valid.

[0047] FIG. 4B shows an example of fluorescence measurement performed on a specimen 200 containing a sample containing a high concentration of the analyte (25 ng / ml). Similar to FIG. 4A, the fluorescence measurement unit 151 illuminates the specimen 200 with excitation light from the excitation light source 103 while switching the excitation light level from level 1 to level 8. The figure also shows the fluorescence measured at each excitation light level. The calibration curves corresponding to the first to eighth excitation light levels shown in FIG. 4A are the same as those in FIG. 4A, namely, the first to eighth calibration curves. The figure first shows that the fluorescence measured at the first excitation light level was below the lower measurement limit (Mmin), and therefore the converted concentration was invalid. Next, the fluorescence measured at the second and subsequent third excitation light levels was within the valid range, and the converted concentration (25 ng / ml) was also considered valid. Furthermore, in subsequent measurements using excitation light levels from the fourth level to the eighth level, the amount of fluorescence reached the upper measurement limit value Mmax, and the converted concentration value was therefore invalid.

[0048] In this manner, in this embodiment, the excitation light is irradiated by sequentially switching the excitation light level from low to high in a predetermined number of steps, measuring the amount of fluorescence, and determining whether the measured fluorescence level is within the valid range to determine the validity of the concentration measurement result obtained by converting the fluorescence amount. With this configuration, for samples containing low concentrations of the analyte, measurement at a high excitation light level can obtain appropriate measurement results, and for samples containing high concentrations of the analyte, measurement at a high excitation light level can obtain appropriate measurement results. In other words, the measurement device 100 of this embodiment can accurately measure concentrations over a wide range, from low to high concentrations.

[0049] In this embodiment, it is also possible to perform measurements while irradiating excitation light by sequentially switching the excitation light level from high to low. However, the fluorescent dye contained in the reagent may experience a decrease in fluorescence intensity due to excitation light. From this perspective, initially irradiating excitation light at a high level is undesirable because it accelerates the decrease in fluorescence intensity. Therefore, in this embodiment, measurements are performed while irradiating excitation light by sequentially switching the excitation light level from low to high. By using this procedure, the decrease in fluorescence intensity during measurements while switching the excitation light level can be made gradual.

[0050] 5, an example of a processing procedure executed by the measurement device 100 in relation to creating a calibration curve to be stored in the calibration curve storage unit 161 will be described. Step S100: In the measurement device 100, the fluorescence amount measurement unit 151 performs initialization by substituting 1 for a variable n, which indicates a number associated with an excitation light level.

[0051] Step S102: The fluorescence amount measurement unit 151 also performs initialization by substituting 1 into a variable m that indicates a number assigned to each calibrator used in measuring the fluorescence amount.

[0052] Step S104: For example, an operator places a test object as the mth calibrator at the measurement position of the measurement device 100.

[0053] Step S106: The fluorescence amount measuring unit 151 causes the excitation light source 103 to irradiate the mth calibrator with excitation light of the nth level.

[0054] Step S108: The fluorescence amount measurement unit 151 measures the fluorescence amount of the mth calibrator in response to the irradiation of the excitation light in step S106. The fluorescence amount measurement unit 151 may temporarily hold the measured fluorescence amount by storing it in the storage unit 106, for example.

[0055] Step S110: The fluorescence amount measurement unit 151 determines whether the current variable m is equal to or greater than the maximum value.

[0056] Step S112: If it is determined in step S110 that the variable m is less than the maximum value, it means that there are still calibrators that have not yet been measured at the currently set nth level. Therefore, in this case, the fluorescence amount measurement unit 151 increments the variable m and then proceeds to step S104. By proceeding to step S104, the fluorescence amount measurement corresponding to irradiation with the nth level excitation light is performed on the next mth calibrator.

[0057] Step S114: If it is determined in step S110 that the variable m is equal to or greater than the maximum value, this means that measurement of the fluorescence amounts for all calibrators at the currently set nth level has been completed. Therefore, the calibration curve creation unit 155 creates an nth calibration curve corresponding to the nth level of excitation light. At this time, the calibration curve creation unit 155 creates the calibration curve based on the fluorescence amount for each calibrator measured in step S108 in response to the nth level of excitation light and the known concentration of each calibrator. The calibration curve creation unit 155 stores the created nth calibration curve in the calibration curve storage unit 161.

[0058] Step S116: After the nth calibration curve is created and stored in step S116, the fluorescence amount measurement unit 151 determines whether the current variable n is equal to or greater than the maximum value.

[0059] Step S118: If it is determined in step S116 that the variable n is less than the maximum value, this means that there are calibration curves corresponding to each excitation light level that have not yet been created. Therefore, in this case, the fluorescence amount measurement unit 151 increments the variable n and then proceeds to step S102. By proceeding to step S102, measurement for each calibrator is started in accordance with the creation of a calibration curve corresponding to the next excitation light level.

[0060] Then, when the creation of calibration curves corresponding to all excitation light levels is completed, it is determined in step S116 that the variable n is equal to or greater than the maximum value, and the process of creating the calibration curve is terminated.

[0061] 6, an example of a processing procedure executed by the measuring device 100 of this embodiment in relation to measuring the concentration of one test object 200 will be described. Step S200: For example, an operator places the test object 200 to be measured at the measurement position of the measuring device 100.

[0062] Step S202: The fluorescence amount measurement unit 151 performs initialization by substituting 1 into a variable n, which indicates a number set in ascending order from the lowest level to the highest level, for a plurality of predetermined excitation light levels.

[0063] Step S204: The fluorescence amount measuring unit 151 causes the excitation light source 103 to irradiate the test object 200 with excitation light of the nth level.

[0064] Step S206: The fluorescence amount measurement unit 151 measures the amount of fluorescence corresponding to the measurement target in the specimen introduced into the test piece 200 in response to the irradiation of excitation light in step S106. At this time, the light receiving unit 104 may obtain image data, for example, showing the detection target area of ​​the test piece 200 in a fluorescent state. The fluorescence amount measurement unit 151 may perform image processing on the image data obtained by the light receiving unit 104, such as pixel value correction, noise removal (e.g., averaging processing for each pixel area), and removal of extreme spike information, as necessary. The fluorescence amount measurement unit 151 uses the image data after image processing to determine the fluorescence amount value (photometric value). When measuring the fluorescence amount for each measurement item, the fluorescence amount measurement unit 151 may apply a calculation corresponding to each measurement item to determine the fluorescence amount value corresponding to each measurement item.

[0065] Step S208: The validity determination unit 153 determines whether the fluorescence amount value measured in step S206 is within the valid range. If it is determined that the fluorescence amount value is not within the valid range, the processes of steps S210 and S212, which will be described next, are skipped. Skipping the processes of steps S210 and S212 makes it unnecessary to obtain a concentration corresponding to a fluorescence amount outside the valid range.

[0066] Step S210: If it is determined that the measured value of the amount of fluorescence is within the valid range, the concentration conversion unit 152 converts the amount of fluorescence measured in step S206 into a concentration using the nth calibration curve.

[0067] Step S212: The concentration conversion unit 152 stores the concentration obtained in step S210 as a valid measurement value. When storing the concentration, the concentration conversion unit 152 may store the concentration obtained in step S210 in the storage unit 106.

[0068] Step S214: After the process of step S212, or if it is determined in step S208 that the value of the amount of fluorescence is not within the valid range, the fluorescence amount measurement unit 151 determines whether the current variable n is equal to or greater than the maximum value.

[0069] Step S216: If it is determined in step S214 that the current variable n is less than the maximum value, there remains an excitation light level that has not yet been used in measuring the test object 200. In this case, the fluorescence amount measurement unit 151 increments the variable n and then proceeds to step S204. By proceeding to step S204 in this way, measurement is performed by irradiating excitation light at the next highest excitation light level.

[0070] Step S218: When measurements using excitation light at all excitation light levels are completed, it is determined in step S214 that the current variable n is equal to or greater than the maximum value. Therefore, the measurement result information output unit 154 causes the user interface unit 102 to output test result information to be presented to the operator based on the concentrations held as valid measurement values ​​in step S212 up to this point. The measurement result information output unit 154 may output test result information presenting concentrations as representative values ​​(e.g., average, median, mode, maximum, minimum, etc.) based on the concentrations held as valid measurement values ​​in step S212 up to this point.

[0071] 6, if the measured amount of fluorescence is outside the effective range, conversion to concentration is not performed, but the measured amount of fluorescence may be converted to concentration even if it is outside the effective range. In addition, the measurement result information output unit 154 may include information about the concentration converted from the amount of fluorescence that is outside the effective range in the measurement result information output from the user interface unit 102.

[0072] Second Embodiment Next, a second embodiment will be described. In the first embodiment, the fluorescence amount is measured for all predetermined excitation light levels, regardless of whether a valid concentration measurement value is obtained. In this embodiment, the fluorescence amount is measured while switching the excitation light level from low to high in order. When the measured fluorescence amount is first determined to be within the valid range, a concentration is obtained, and subsequent fluorescence amount measurements and the process of converting the measured fluorescence amount into a concentration are stopped. This procedure of this embodiment makes it possible to shorten the time required to measure one test object 200.

[0073] 7, an example of a processing procedure executed by the measurement device 100 of this embodiment in relation to measuring the concentration of one test object 200 will be described. Steps S300 to S308 are similar to the processing of steps S200 to S208 in FIG.

[0074] Step S310: If it is determined in step S308 that the value of the amount of fluorescence is not within the valid range, the fluorescence amount measurement unit 151 determines whether the current variable n is equal to or greater than the maximum value.

[0075] Step S312: If it is determined in step S310 that the current variable n is less than the maximum value, there remains an excitation light level that has not yet been used in measuring the test object 200. In this case, the fluorescence amount measurement unit 151 increments the variable n and then proceeds to step S304.

[0076] Step S314: If it is determined in step S310 that the current variable n is equal to or greater than the maximum value, it means that none of the fluorescence amounts measured at all excitation light levels are within the valid range. In this case, the measurement result information output unit 154 causes the user interface unit 102 to output a measurement error indicating that a valid measurement result was not obtained.

[0077] Step S316: If it is determined in step S308 that the value of the amount of fluorescence is within the valid range, the concentration conversion unit 152 converts the amount of fluorescence measured in the last executed step S306 into a concentration.

[0078] Step S318: The measurement result information output unit 154 causes the user interface unit 102 to output the measurement result information indicating the concentration obtained in step S316. After the processing of step S318, the processing in the figure is terminated. In other words, the measurement corresponding to the specimen 200 placed in step S300 is terminated without further measurement of the fluorescence intensity while switching the excitation light level to a higher level.

[0079] Third Embodiment Next, a third embodiment will be described. In this embodiment, among a plurality of predetermined excitation light levels, for example, one excitation light level somewhere in the middle is set as the standard level. The standard level may be selected as the excitation light level that is most likely to measure an effective concentration for the expected range of concentrations of the analyte in the sample. Then, in measuring the concentration, the measurement device 100 of this embodiment first measures the amount of fluorescence by irradiating excitation light at the standard level. If the amount of fluorescence measured at the standard level is within the effective range, the measurement device 100 outputs the concentration converted from the measured amount of fluorescence as the detection result. On the other hand, if the amount of fluorescence measured at the standard level is smaller than the effective range, the measurement device 100 measures the amount of fluorescence while sequentially switching the excitation light level, increasing it by one step from the standard level until the amount of fluorescence falls within the effective range. Furthermore, if the amount of fluorescence measured at the standard level is larger than the effective range, the measurement device 100 measures the amount of fluorescence while sequentially switching the excitation light level, decreasing it by one step from the standard level until the amount of fluorescence falls within the effective range. Such a measurement procedure makes it possible to reduce the number of measurements required depending on the excitation light level, thereby shortening the time required to measure one test piece 200 .

[0080] 8, an example of a processing procedure executed by the measuring device 100 of this embodiment in relation to measuring the concentration of the test object 200 will be described. Step S400: For example, an operator places the test object 200 to be measured at the measurement position of the measuring device 100.

[0081] Step S402: The fluorescence intensity measurement unit 151 initializes a variable n, which indicates numbers set in ascending order from low to high for a plurality of predetermined excitation light levels, by substituting the numerical value of the number of the excitation light level set as the standard level.

[0082] Steps S404 to S408 are the same as steps S204 to S208 in FIG.

[0083] Step S410: If it is determined in step S408 that the amount of fluorescence is within the valid range, the concentration conversion unit 152 converts the amount of fluorescence measured in the last executed step S406 into a concentration.

[0084] Step S412: The measurement result information output unit 154 causes the user interface unit 102 to output the measurement result information indicating the concentration obtained in step S410. After the processing of step S412, the processing in the figure ends. In other words, the measurement corresponding to the specimen 200 placed in step S400 is ended without further measurement of the fluorescence intensity while switching the excitation light level to a higher level.

[0085] Step S414: If it is determined in step S408 that the amount of fluorescence is not within the valid range, the fluorescence amount measurement unit 151 determines whether the current variable n is equal to or greater than the maximum value or equal to or less than the minimum value.

[0086] Step S416: If step S414 determines that the current variable n is less than the maximum value and greater than the minimum value, it means that the excitation light level has not yet been switched to the maximum or minimum level. Therefore, in this case, the fluorescence amount measurement unit 151 further determines whether the fluorescence amount measured in the most recently executed step S406 is less than the measurement lower limit value Mmin.

[0087] Step S418: If it is determined in step S416 that the amount of fluorescence is less than the measurement lower limit Mmin, the excitation light level should be increased by one level from the current level and measurement should be performed again. Therefore, in this case, the fluorescence amount measurement unit 151 increments the variable n and proceeds to step S404. By proceeding to step S404 in this way, the amount of fluorescence is measured at the excitation light level that is one level higher.

[0088] Step S420: If it is determined in step S416 that the amount of fluorescence is not less than the lower measurement limit Mmin, it means that the amount of fluorescence has reached the upper measurement limit Mmax. In this case, the excitation light level should be lowered by one level from the current level and measurement should be performed again. Therefore, in this case, the fluorescence amount measurement unit 151 decrements the variable n and proceeds to step S404. By proceeding to step S404 in this way, the amount of fluorescence is measured at an excitation light level one level lower.

[0089] 9 shows an example of the hardware configuration of the measurement device 100. The measurement device 100 in the figure includes an input / output interface 1001, a ROM 1003, a RAM 1004, a storage 1005, and a CPU 1006. As shown in the figure, the input / output interface 1001, the ROM 1003, the RAM 1004, the storage 1005, and the CPU 1006 are connected by a bus 1100.

[0090] The input / output interface 1001 inputs and outputs information. The input / output interface 1001 inputs and outputs information with, for example, external devices, other devices with communication functions, servers, or controls or input devices operated by an operator of the measuring device 100, a device that irradiates excitation light, and a device that receives fluorescence generated in the test specimen 200. The input / output interface 1001 corresponds to the input / output unit 101, the user interface unit 102, and an interface that exchanges information between the excitation light source 103 and the light receiving unit 104 in FIG. 1. The light source device 1021 is a component configured to irradiate excitation light onto a sample 1030 placed at a predetermined position in the measuring device 100. The light source device 1021 corresponds to the excitation light source 103 in FIG. 1. The sample 1030 corresponds to the test specimen 200 in FIG. 1. The light receiving device 1022 outputs a light intensity signal corresponding to the amount of fluorescence generated in the sample 1030. The light receiving device 1022 corresponds to the light receiving unit 104 in FIG. 1.

[0091] The ROM 1003 stores non-rewritable data. The RAM 1004 temporarily stores data used in calculations performed by the CPU 1006. The storage 1005 is, for example, an HDD or SSD, and stores various data including program data. The CPU 1006 executes programs stored in the storage 1005 to perform calculations corresponding to various controls and processes. Note that functions equivalent to those of the measuring device 100 may be achieved by multiple network-compatible devices distributed over a network so that predetermined processes can be executed.

[0092] <Modifications> Modifications of the above embodiments will now be described.

[0093] [First Modification] In the second and third embodiments, the measurement is terminated when the first valid concentration is measured. In this modification, after the first valid concentration is measured, the excitation light level may be changed by one step at a time to measure the concentration, and the measurement may be terminated when the next measured concentration becomes invalid. As a specific example, in correspondence with the example of FIG. 4B , the excitation light level may be changed by increasing it by one step from the first level to measure the concentration, and the measurement may be terminated when the concentration is determined to be invalid at the fourth level.

[0094] [Second Modification] For example, when measuring the amount of fluorescence while switching the excitation light level from low to high, if it is determined that the concentration of the substance to be measured in the sample is significantly low (the amount of fluorescence is low), the fluorescence amount measurement unit 151 may change the procedure to increase the number of measurements at the higher excitation light level. Specifically, for example, the fluorescence amount measurement unit 151 may increase the number of measurements at the maximum excitation light level. Alternatively, the fluorescence amount measurement unit 151 may, for example, narrow the interval between higher excitation light levels to increase the number of steps of the higher excitation light level, and measure the amount of fluorescence by switching the excitation light level in order to successively increase the number of steps.

[0095] [Third Modification] In each of the above embodiments, each time the fluorescence amount measurement unit 151 measures the fluorescence amount corresponding to the measurement target in the specimen by irradiating excitation light while switching the excitation light level, the fluorescence amount measurement unit 151 may also measure the fluorescence amount of an inner calibrator provided in the test piece 200. The fluorescence amount measurement unit 151 may determine, based on the measured fluorescence amount of the inner calibrator, whether or not excitation light corresponding to the set excitation light level is being normally irradiated from the excitation light source 103.

[0096] [Fourth Modification] When the measuring device 100 is capable of performing measurements corresponding to multiple different measurement items, the excitation light intensity to be used for each measurement item may be predetermined. For example, for a measurement item such as testosterone, which is considered to have a relatively high blood concentration, a low excitation light intensity may be used from the beginning to measure the measurement. Furthermore, for a measurement item such as TSH, which has a low blood concentration and requires high sensitivity, a high excitation light intensity may be used from the beginning to measure the measurement. The fluorescence intensity measuring unit 151 of the measuring device 100 may then change the number of measurements and measurement time for measuring the fluorescence intensity for each measurement item, depending on the excitation light intensity determined for that measurement item. The number of measurements may correspond to the number of excitation light levels. In other words, the number of excitation light levels may be changed depending on the measurement item. The measurement time may correspond to the time required to irradiate excitation light at one excitation light level. This modification, for example, can reduce the number of measurements and measurement time, thereby shortening the time required to complete the measurement and suppressing the decrease in fluorescence intensity during the measurement process.

[0097] [Fifth Modification] In each of the above embodiments, the calibration curve storage unit 161 stores a calibration curve for each excitation light level. In this modification, the calibration curve storage unit 161 may store a calibration curve corresponding to a specific excitation light level among all excitation light levels. Then, when measuring the concentration of a single specimen 200 using an excitation light level different from the specific excitation light level, the calibration curve creation unit 155 may calculate a calibration curve corresponding to the other excitation light level from the calibration curve corresponding to the specific excitation light level by a predetermined calculation. In this case, the calibration curve creation unit 155 may obtain a calibration curve corresponding to the other excitation light level by, for example, changing the calibration curve corresponding to the specific excitation light level using a coefficient corresponding to the ratio (an example of the degree of difference) between the specific excitation light level and the other excitation light level.

[0098] [Sixth Modification] When the light receiving unit 104 in the measurement device 100 is configured with a CMOS sensor, the fluorescence amount measurement unit 151 may perform control to change the gain and exposure time of the CMOS sensor when measuring the fluorescence amount while gradually switching the excitation light level. In this way, by combining switching the excitation light level with changing the gain and exposure time of the CMOS sensor, it is possible to expand the upper and lower limits of the effective range for the fluorescence amount to be measured, and it becomes possible to measure concentrations over a wider range.

[0099] 1 may be configured as a system in which the functions of the measuring device 100 shown in Fig. 1 are appropriately distributed among a plurality of devices. In this case, the functions of the measuring device 100 of each of the above-described embodiments may be realized by the plurality of devices operating in cooperation with each other via communication. In this case, some of the devices may be configured as servers on a network, cloud servers, or the like.

[0100] The processing of the measuring device 100 may be performed by recording a program for implementing the functions of the measuring device 100 on a computer-readable recording medium, and then loading and executing the program and reagent parameters recorded on the recording medium into a computer system. Here, "loading and executing a program or parameters recorded on a recording medium into a computer system" includes installing the program or parameters into a computer system. The term "computer system" as used herein includes hardware such as an operating system (OS) and peripheral devices. The term "computer system" may also include multiple computer devices connected via a network, including communication lines such as the Internet, WAN, LAN, and dedicated lines. The term "computer-readable recording medium" refers to portable media such as floppy disks, optical magnetic disks, ROMs, CD-ROMs, and printed codes, as well as storage devices such as hard disks built into a computer system. The recording medium storing the program may be a non-transitory recording medium such as a CD-ROM. The recording medium may also include internal or external recording media accessible from a distribution server for distributing the program. The program code stored on the distribution server's recording medium may be different from the program code executable on a terminal device. In other words, the format in which the program is stored on the distribution server does not matter as long as it can be downloaded from the distribution server and installed in a form that is executable on the terminal device. The program may be divided into multiple parts, each of which may be downloaded at different times and then combined on the terminal device, or each of the divided programs may be distributed by a different distribution server. Furthermore, the term "computer-readable recording medium" also includes a storage medium that stores a program for a certain period of time, such as volatile memory (RAM) within a computer system that serves as a server or client when a program is transmitted over a network. The program may also be one that realizes part of the functions described above.Furthermore, the above-mentioned functions may be realized in combination with a program already recorded in the computer system, that is, a so-called differential file (differential program).

[0101] <Notes> (1) One aspect of this embodiment is a measurement device that includes a fluorescence amount measurement unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source and measures the amount of fluorescence emitted in accordance with the amount of a substance to be measured in a specimen introduced into a test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the fluorescence amount under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the fluorescence amount measured by the fluorescence amount measurement unit into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

[0102] (2) One aspect of this embodiment is the measurement device described in (1), in which the fluorescence amount measurement unit selects one excitation light level from the plurality of predetermined excitation light levels in order from lowest to highest, sequentially irradiates excitation light at the selected excitation light level using the excitation light source, measures the fluorescence amount of the same test specimen for each excitation light irradiated at the selected excitation light level, and the concentration conversion unit converts the fluorescence amount measured corresponding to the excitation light level selected by the fluorescence amount measurement unit into a concentration based on fluorescence amount / concentration relationship information acquired corresponding to the selected excitation light level.

[0103] (3) One aspect of this embodiment is the measurement device described in (1), wherein the fluorescence amount measurement unit causes the excitation light source to irradiate excitation light at an excitation light level that is determined as a standard among the plurality of predetermined excitation light levels, and if the fluorescence amount measured in response to irradiation with excitation light at the excitation light level determined as the standard is less than a predetermined amount, selects excitation light levels in order from the standard to higher levels, and if the fluorescence amount measured in response to irradiation with excitation light at the excitation light level determined as the standard is greater than the predetermined amount, selects excitation light levels in order from the standard to lower levels.

[0104] (4) One aspect of this embodiment is the measurement device described in (2) or (3), in which the fluorescence amount measurement unit may stop subsequent measurements when the judgment result by the validity judgment unit corresponding to each sequentially selected excitation light level changes from a previous judgment result of ineffective to a judgment result of validity.

[0105] (5) One aspect of this embodiment is a measurement device according to any one of (1) to (4), which may further include a memory unit that stores multiple pieces of fluorescence amount-concentration relationship information created in correspondence with each of the multiple predetermined excitation light levels.

[0106] (6) One aspect of this embodiment is a measurement device according to any one of (1) to (4), which may further include a memory unit that stores fluorescence amount-concentration relationship information created in correspondence with a specific excitation light level among the plurality of predetermined excitation light levels, and a calibration curve creation unit that calculates a calibration curve corresponding to the other excitation light levels from the fluorescence amount-concentration relationship information stored in the memory unit by a predetermined calculation based on the degree of difference between the specific excitation light level and other excitation light levels.

[0107] (7) One aspect of this embodiment is a measurement device described in any one of (1) to (6), wherein the validity determination unit may determine whether the concentration obtained by converting the measured fluorescence amount by the concentration conversion unit is valid based on whether the fluorescence amount measured by the fluorescence amount measurement unit is within an effective range that is considered valid as a measurement value.

[0108] (8) One aspect of this embodiment is the measurement device described in (7), in which the concentration conversion unit does not need to convert the corresponding measured fluorescence amount into a concentration for a concentration that is not determined to be effective by the effectiveness determination unit.

[0109] (9) One aspect of this embodiment is a measurement method for a measurement device, the measurement method including: a fluorescence amount measurement step in which a fluorescence amount measurement unit irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source, and measures the amount of fluorescence emitted in accordance with the amount of a substance to be measured in a specimen introduced into the test piece that has received the irradiated excitation light; a concentration conversion step in which a concentration conversion unit acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the amount of fluorescence under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the amount of fluorescence measured in the fluorescence amount measurement step into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination step in which a validity determination unit determines whether the concentration obtained in the concentration conversion step is valid.

[0110] (10) One aspect of this embodiment is a program that causes a computer serving as a measurement device to function as: a fluorescence amount measurement unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source and measures the amount of fluorescence emitted in accordance with the amount of the substance to be measured in a specimen introduced into the test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the fluorescence amount under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the fluorescence amount measured by the fluorescence amount measurement unit into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

[0111] 100 Measuring device, 101 Input / output unit, 102 User interface unit, 103 Excitation light source, 104 Light receiving unit, 105 Control unit, 106 Memory unit, 151 Fluorescence amount measurement unit, 152 Concentration conversion unit, 153 Effectiveness determination unit, 154 Measurement result information output unit, 155 Calibration curve creation unit, 161 Calibration curve memory unit, 200 Test specimen, 1001 Input / output interface, 1003 ROM, 1004 RAM, 1005 Storage, 1006 CPU, 1011 Input / output device, 1021 Light source device, 1022 Light receiving device, 1030 Sample, 1100 Bus

Claims

1. A measurement device comprising: a fluorescence amount measurement unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source and measures the amount of fluorescence emitted in accordance with the amount of a substance to be measured in a specimen introduced into a test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence amount-concentration relationship information corresponding to the selected excitation light level from fluorescence amount-concentration relationship information that indicates the relationship between the amount of fluorescence and the concentration of the substance to be measured in the specimen under conditions where excitation light is irradiated at each of the plurality of predetermined excitation light levels, and converts the amount of fluorescence measured by the fluorescence amount measurement unit into the concentration of the substance to be measured in the specimen that has received the excitation light based on the acquired fluorescence amount-concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

2. The measurement device of claim 1, wherein the fluorescence amount measuring unit selects one excitation light level from the plurality of predetermined excitation light levels in order from lowest to highest, sequentially irradiates excitation light at the selected excitation light level using the excitation light source, and measures the fluorescence amount of the same test specimen for each excitation light irradiated at the selected excitation light level, and the concentration conversion unit converts the fluorescence amount measured corresponding to the excitation light level selected by the fluorescence amount measuring unit into a concentration based on fluorescence amount / concentration relationship information acquired corresponding to the selected excitation light level.

3. The measurement device according to claim 1, wherein the fluorescence amount measurement unit irradiates excitation light at an excitation light level determined as a standard from among the plurality of predetermined excitation light levels using the excitation light source, and if the fluorescence amount measured in response to irradiation with excitation light at the excitation light level determined as the standard is less than a predetermined amount, selects excitation light levels in order from the standard to higher levels, and if the fluorescence amount measured in response to irradiation with excitation light at the excitation light level determined as the standard is greater than the predetermined amount, selects excitation light levels in order from the standard to lower levels.

4. The measurement device of claim 2 or 3, wherein the fluorescence measurement unit stops further measurement when the judgment result by the validity judgment unit corresponding to each sequentially selected excitation light level changes from a previous judgment result of ineffective to a judgment result of validity.

5. A measuring device according to any one of claims 1 to 3, further comprising a memory unit for storing a plurality of pieces of fluorescence amount / concentration relationship information created in correspondence with each of the plurality of predetermined excitation light levels.

6. A measuring device according to any one of claims 1 to 3, further comprising: a memory unit that stores fluorescence amount / concentration relationship information created in correspondence with a specific excitation light level among the plurality of predetermined excitation light levels; and a calibration curve creation unit that calculates calibration curves corresponding to the other excitation light levels from the fluorescence amount / concentration relationship information stored in the memory unit by a predetermined calculation based on the degree of difference between the specific excitation light level and other excitation light levels.

7. A measuring device as described in any one of claims 1 to 3, wherein the validity determination unit determines whether the concentration obtained by converting the measured fluorescence amount by the concentration conversion unit is valid based on whether the fluorescence amount measured by the fluorescence amount measurement unit is within an effective range that is considered valid as a measurement value.

8. The measurement device according to claim 7, wherein the concentration conversion section does not convert the corresponding measured amount of fluorescence into a concentration for a concentration that is not determined to be effective by the effectiveness determination section.

9. A measurement method for a measurement device, comprising: a fluorescence amount measurement step in which a fluorescence amount measurement unit irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source, and measures the amount of fluorescence emitted in response to the measurement target in a specimen introduced into the test piece that has received the irradiated excitation light; a concentration conversion step in which a concentration conversion unit acquires fluorescence amount / concentration relationship information corresponding to the selected excitation light level from fluorescence amount / concentration relationship information that indicates the relationship between the fluorescence amount under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the measurement target in the specimen, and converts the fluorescence amount measured in the fluorescence amount measurement step into the concentration of the measurement target in the specimen that has received the excitation light based on the acquired fluorescence amount / concentration relationship information; and a validity determination step in which a validity determination unit determines whether the concentration obtained in the concentration conversion step is valid.

10. A program for causing a computer as a measuring device to function as: a fluorescence amount measuring unit that irradiates excitation light at an excitation light level selected from a plurality of predetermined excitation light levels from an excitation light source, and measures the amount of fluorescence emitted in accordance with the amount of the substance to be measured in a specimen introduced into a test piece that has received the irradiated excitation light; a concentration conversion unit that acquires fluorescence amount / concentration relationship information corresponding to the selected excitation light level from fluorescence amount / concentration relationship information that indicates the relationship between the fluorescence amount under conditions in which excitation light at each of the plurality of predetermined excitation light levels is irradiated and the concentration of the substance to be measured in the specimen, and converts the fluorescence amount measured by the fluorescence amount measuring unit into the concentration of the substance to be measured in a specimen that has been introduced into the test piece that has received the excitation light, based on the acquired fluorescence amount / concentration relationship information; and a validity determination unit that determines whether the concentration obtained by the concentration conversion unit is valid.

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