Analysis device and LED light source state determination method

Abstract

To accurately determine the state of an LED light source and predict time for replacement of the LED light source regardless of an individual difference of the LED light source and the condition of a usage environment. To solve the problem, the present disclosure proposes an analysis device comprising: an LED light source for applying light to a liquid to be analyzed in a container accommodating the liquid; a photodetector for detecting light emitted from the liquid by the LED light source applying the light to the liquid; and a data processing unit for performing a process of determining the state of the LED light source on the basis of (i) the maximum amount of light in a period from when the LED light source is turned on until a predetermined time elapses and the amount of light from the LED light source stabilizes, (ii) the time until the maximum amount of light is reached, or (iii) the rate of change in the maximum amount of light with respect to the energization time of the LED light source.

Description

Analysis device and LED light source state determination method

[0001] The present disclosure relates to an analysis device and a method for determining the state of an LED light source.

[0002] Analytical devices can be used to analyze the amounts of components, such as proteins, sugars, lipids, enzymes, hormones, inorganic ions, and disease markers, contained in biological samples such as blood and urine. Analytical devices typically dispense specimens and reagents into liquid containers and analyze test items based on changes in optical properties such as absorbance, fluorescence, and luminescence. In absorbance analysis using an analytical device, light from a light source is irradiated onto a sample or a reaction solution containing a mixture of the sample and reagent, and the amount of transmitted light at one or more measurement wavelengths that passes through the sample or reaction solution is measured using a light-receiving element to calculate absorbance. The amount of a component can then be determined from the relationship between the calculated absorbance and concentration.

[0003] The light source for absorption spectrometry should have a wide emission spectrum to accommodate a large number of test items, and should be able to stably emit a certain amount of light at the measurement wavelength to enable highly accurate absorbance measurements. For this reason, xenon lamps, halogen lamps, etc. have traditionally been used.

[0004] In recent years, in order to reduce the frequency of light source replacement, light-emitting diodes (hereinafter referred to as "LEDs"), which are expected to have a long life, have been considered as light sources for absorption spectrometry. However, like xenon lamps and halogen lamps, even when LEDs are used as light sources for absorption spectrometry, materials such as light-emitting chips, phosphors, and resins deteriorate over time, resulting in a gradual decrease in light output. Therefore, even when LED light sources are used, a method for determining the condition of LED light sources and a method for predicting when they should be replaced are needed.

[0005] Generally, when predicting the replacement time of an LED light source used in lighting fixtures, etc., the replacement time is determined to be when the light intensity of the LED light source falls below a threshold value of the initial light intensity (e.g., 70%). For example, Patent Document 1 discloses a technology that "integrates the lighting time of an LED while it is on, and notifies the user that the LED has reached the end of its life when the integrated lighting time reaches a preset life time." Patent Document 2 also discloses an "LED degradation measurement device that determines the degree of degradation of an LED based on the forward voltage-forward current characteristics of the LED."

[0006] JP 10-39836 A JP 2015-32793 A

[0007] However, if the degradation state or replacement time is determined to be when the light intensity of an LED light source falls below an initial light intensity threshold (e.g., 70%), as in conventional light source condition determination and replacement time prediction, the initial light intensity may vary due to individual differences between LED light sources. For example, even if the light intensity falls below the initial light intensity threshold, the variation in the initial light intensity may cause replacement to occur even if the light intensity is sufficient to maintain the analytical performance of the analyzer. Furthermore, if the degradation state or replacement time is determined to be when the LED light source's lighting time reaches a predetermined lifespan, the individual differences between LED light sources and the environmental conditions used may cause replacement to occur even if the light intensity is sufficient to maintain the analytical performance of the analyzer. As such, conventional condition determination and replacement time prediction were unable to determine the state of an LED light source or the predicted replacement time for each LED light source, despite the fact that the state of each individual LED light source varies due to individual differences between LED light sources and the environmental conditions used.

[0008] Furthermore, using the forward voltage-forward current characteristics as in Patent Document 2 requires a new measurement system for monitoring the current and voltage applied to the LED light source. Furthermore, there is a need for a means for determining the condition and predicting the replacement time based on LED characteristics that can be measured in as short a time as possible, without taking the time to measure the LED characteristics.

[0009] In view of such circumstances, the present disclosure proposes a technique for accurately determining the state of an LED light source and predicting when to replace the LED light source, regardless of individual differences between LED light sources or conditions of the usage environment.

[0010] In order to solve the above problems, the present disclosure proposes an analytical device comprising an LED light source that irradiates light onto a liquid in a container that holds the liquid to be analyzed; a photodetector that detects light emitted from the liquid by irradiating the liquid with light using the LED light source; and a data processing unit that executes processing to determine the state of the LED light source based on (i) the maximum light intensity during the period from when the LED light source is turned on until a predetermined time has elapsed until the amount of light from the LED light source stabilizes, (ii) the time until the maximum light intensity is reached, or (iii) the rate of change of the maximum light intensity relative to the time the LED light source is turned on.

[0011] Further features related to the present disclosure will become apparent from the description of this specification and the accompanying drawings. Also, aspects of the present disclosure are achieved and realized by the elements and combinations of various elements and the aspects of the following detailed description and the appended claims. The description of this specification is merely exemplary and does not limit the scope or application of the claims of the present disclosure in any way.

[0012] According to the technology of the present disclosure, it is possible to accurately determine the state of an LED light source and predict when to replace the LED light source, regardless of individual differences between LED light sources or conditions of the usage environment.

[0013] 1 is a schematic diagram showing an example of the overall configuration of the automatic analyzer 100. It is a hardware block diagram of the data processing unit 203. It is a diagram showing the contents (example) of history data 2033a. It is a diagram showing an example of the configuration of the absorbance measurement unit 113 that measures absorbance of the automatic analyzer 100. It is a flowchart for explaining the operation of the automatic analyzer 100. It is a flowchart for explaining details of the state determination process (S506). It is a flowchart for explaining details of the replacement time prediction process (S507). It is a diagram showing the results of the light intensity fluctuation immediately after turning on white LEDs with different power-on times. It is a diagram showing the correlation between the power-on time of the LED and the maximum light intensity until the light intensity of the light from the LED light source stabilizes. It is a diagram showing the correlation between the power-on time of the LED and the time until the light intensity of the light from the LED light source stabilizes and reaches the maximum light intensity. It is a diagram showing the results of the light intensity fluctuation after turning on the white LED (1800 seconds from turning on) before and after data correction.

[0014] An embodiment of the present disclosure proposes determining the state of an LED light source or predicting the replacement time of an LED light source based on the maximum light intensity until the light intensity stabilizes after a certain time has passed since the LED light source was turned on, the time until the maximum light intensity is reached, or the rate of change of the maximum light intensity relative to the time the LED light source is powered on. Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. It goes without saying that in the present embodiment, components (including element steps, etc.) are not necessarily essential unless otherwise specified or considered to be clearly essential in principle.

[0015] (Automated analyzer 100) An overview of the automated analyzer 100 of this embodiment will be described using FIG. 1. The automated analyzer 100 of FIG. 1 includes three types of disks: a sample disk 103, a reagent disk 106, and a reaction disk 109; a dispensing mechanism for moving samples and reagents between these disks; and a control unit 201 for controlling these. The automated analyzer 100 also includes a light quantity measurement circuit 202 for measuring the absorbance of the liquid to be analyzed (reaction solution); a data processing unit 203 for processing measurement data measured by the light quantity measurement circuit 202; and an input unit 204 and an output unit 205 that interface with the data processing unit 203. The data processing unit 203 can be configured as a computer. The dispensing mechanism includes a sample dispensing mechanism 110 and a reagent dispensing mechanism 111.

[0016] The data processing unit 203 stores the measurement data measured by the light quantity measurement circuit 202 and analyzes the stored measurement data. The analysis results are output to, for example, the output unit 205. The details of the data processing unit 203 will be described later.

[0017] The input unit 204 and output unit 205 input and output data to and from the data processing unit 203. The input unit 204 is an information input device such as a keyboard, a touch panel, or a numeric keypad. The output unit 205 is an information output device, such as a display, for outputting the analysis results of the automatic analyzer 100.

[0018] A plurality of sample cups 102, which are containers for holding samples 101, are arranged on the circumference of the sample disk 103. The samples 101 are, for example, blood. A plurality of reagent bottles 105, which are containers for holding reagents 104, are arranged on the circumference of the reagent disk 106. A plurality of reaction cells 108, which are containers for holding reaction solutions 107 to be analyzed, which are mixtures of the samples 101 and the reagents 104, are arranged on the circumference of the reaction disk 109.

[0019] The sample dispensing mechanism 110 is a mechanism used when transferring a fixed amount of sample 101 from the sample cup 102 to the reaction cell 108. The sample dispensing mechanism 110 is composed of, for example, a nozzle that dispenses or aspirates a solution, a robot that positions and transports the nozzle to a predetermined position, a pump that dispenses or aspirates a solution from the nozzle, and a flow path that connects the nozzle and the pump.

[0020] The reagent dispensing mechanism 111 is a mechanism used when transferring a fixed amount of reagent 104 from the reagent bottle 105 to the reaction cell 108. The reagent dispensing mechanism 111 also includes, for example, a nozzle that dispenses or aspirates a solution, a robot that positions and transports the nozzle to a predetermined position, a pump that dispenses or aspirates a solution from the nozzle, and a flow path that connects the nozzle and the pump.

[0021] The solution stirring unit 112 is a mechanism that stirs and mixes the sample 101 and the reagent 104 in the reaction cell 108. The washing unit 114 is a mechanism that discharges the reaction solution 107 from the reaction cell 108 after the analysis process has been completed, and then washes the reaction cell 108. After the washing process is completed, the next sample 101 is dispensed into the reaction cell 108 from the sample dispensing mechanism 110, and new reagent 104 is dispensed from the reagent dispensing mechanism 111, and the reaction cell 108 is used for another reaction process.

[0022] In the reaction disk 109, the reaction cells 108 are immersed in a constant temperature fluid 115 in a constant temperature bath whose temperature and flow rate are controlled. Therefore, the reaction cells 108 and the reaction solutions 107 therein are kept at a constant temperature by the control unit 201 even while being moved by the reaction disk 109. The constant temperature fluid 115 is, for example, water or air.

[0023] An absorbance measuring unit 113 that performs absorbance analysis in the automatic analyzer 100 is disposed on a portion of the circumference of the reaction disk 109 .

[0024] (Data Processing Unit 203) Fig. 2 is a hardware block diagram of the data processing unit 203. The data processing unit 203 has a processor 2031, a main memory unit 2032, an auxiliary memory unit 2033, and an input / output I / F 2034. The processor 2031 is a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), or the like. The main memory unit 2032 is a dynamic random access memory (DRAM) or the like, and is used as a working area for the processor 2031. The auxiliary memory unit 2033 is a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof, or the like, and stores various programs and various data. The input / output I / F 2034 is an interface that communicably connects the data processing unit 203 with peripheral devices of the data processing unit 203 (for example, the control unit 201, the light quantity measurement circuit 202, the input unit 204, and the output unit 205).

[0025] In this embodiment, the auxiliary storage unit 2033 stores history data 2033a, a status determination program 2033b, and a replacement time prediction program 2033c. The status determination program 2033b is a program that determines the status of the LED light source 301 (see FIG. 4 ) using the maximum light intensity X (hereinafter referred to as "maximum light intensity X") until the light intensity from the LED light source 301 stabilizes. Here, "the light intensity stabilizes" refers to the LED light source 301 being in a state where analysis is possible, such as a state after a predetermined time (e.g., 30 minutes) has elapsed since the automatic analyzer 100 was started. Furthermore, the light intensity in the stable state falls within a range of 100±0.2% (0.2%: 0.2% of the light intensity when 100 is used), where 100 is the light intensity when analysis is started and there are no problems (a state where analysis is possible). In this embodiment and in each example described later, the operation etc. of the LED light source 301 will be described as a light source composed of an LED chip and phosphor (for example, the maximum light intensity X described later means the maximum light intensity of the LED chip and phosphor), but the technology disclosed herein can also be applied to a light source composed of a single LED chip.

[0026] The processor 2031 executes the state determination program 2033b to determine the state of the LED light source 301 using the maximum light intensity X until the light intensity of the LED light source 301 stabilizes, and outputs the determination result. The replacement time prediction program 2033c is a program that predicts the replacement time of the LED light source 301 based on the correlation between the maximum light intensity X and the power-on time T of the LED light source 301. The processor 2031 executes the replacement time prediction program 2033c to predict the replacement time of the LED light source 301 using the maximum light intensity X until the light intensity of the LED light source 301 stabilizes, and outputs the prediction result.

[0027] The auxiliary storage unit 2033 may also store measurement data measured by the light quantity measurement circuit 202, an analysis program for analyzing the measurement data, analysis results obtained by the analysis program, and the like.

[0028] FIG. 3 is a diagram showing the contents of the history data 2033a. The history data 2033a stores the power-on time T of the LED light source 301 and the maximum light intensity X measured during the power-on time T and the period until the light intensity from the LED light source 301 stabilizes (e.g., 30 minutes after restart). In the example of FIG. 3 , the maximum light intensity is calculated using a relative light intensity value (%) when the light intensity at the start of power-on (time 0 of power-on) is set to 100%. However, when the light intensity is expressed as a relative value, the reference light intensity for 100% does not have to be the light intensity at the start of power-on (time 0 of power-on). Furthermore, the light intensity does not have to be a relative value; a photocurrent value acquired by the device may also be used. In the example of FIG. 3 , the maximum light intensity X is measured every 3000 hours. However, the measurement interval for the maximum light intensity X is not limited to 3000 hours and may be shorter or longer than 3000 hours. Furthermore, although the maximum light intensity X is measured at regular intervals in the example of FIG. 3 , the measurement intervals for the maximum light intensity X do not have to be regular intervals. Furthermore, the operating time of the automatic analyzer 100 may be used instead of or in addition to the power-on time T of the LED light source 301. As shown in FIG. 3 , the maximum light intensity at 1000 hours of power-on time and every 3000 hours thereafter is recorded as history data 2033a. However, the maximum light intensity may be measured each time the automatic analyzer 100 is started (restarted) and recorded as history data 2033a. By collecting history data 2033a each time the automatic analyzer 100 is started, the amount of data can be increased when calculating an approximate straight line (approximate curve), as described below, allowing for a more accurate approximate straight line (approximate curve).

[0029] When a new maximum light quantity X is measured, the measured maximum light quantity X is stored in association with the power supply time T in a new record of the history data 2033a.

[0030] (Absorbance measurement unit 113) Fig. 4 is a diagram showing an example of the configuration of the absorbance measurement unit 113 that measures absorbance in the automatic analyzer 100. In the automatic analyzer 100 of this embodiment, an LED light source 301 is used as the light source unit for absorbance measurement. The irradiation light generated from the LED light source 301 is emitted along an optical axis 401, condensed by a condenser lens 403, and irradiated onto the reaction solution 107 in the reaction cell 108. At this time, a light source-side slit 402 may be arranged to limit the width of the light emitted from the LED light source 301 in order to uniformly distribute the light amount within the irradiation surface of the light.

[0031] Light transmitted through the reaction solution 107 in the reaction cell 108 is dispersed by a diffraction grating 3021 in the spectroscope 302 and received by a detector array 3022 equipped with a large number of light receivers. The detector array 3022 is an example of a photodetector. At this time, light that has not transmitted through the reaction solution 107 becomes noise, so a spectroscope-side slit 404 may be provided to prevent such stray light from entering the spectroscope 302. In this embodiment, the detector array 3022 detects light transmitted through the reaction solution 107, but the detector array 3022 (photodetector) may also detect light emitted from the reaction solution 107 (for example, optical properties such as light absorption, fluorescence, and light emission).

[0032] The detector array 3022 receives light of a plurality of measurement wavelengths (capable of measuring light of a plurality of wavelengths). The light received by the detector array 3022 is converted into an electrical signal (light-receiving signal) and stored as measurement data in the auxiliary memory unit 2033 of the data processing unit 203 via the light quantity measurement circuit 202.

[0033] On the other hand, the absorbance measurement unit 113 is also used to measure the maximum light intensity X until the light intensity of the LED light source 301 stabilizes. When measuring the maximum light intensity X, the reaction cell 108 is not placed on the optical axis 401, or the reaction cell 108 is placed without containing the reaction solution 107. The irradiated light generated from the LED light source 301 is emitted along the optical axis 401 and condensed by the condenser lens 403. The condensed light is dispersed by the diffraction grating 3021 and received by the detector array 3022. The light received by the detector array 3022 is converted into an electrical signal (light-received signal) and stored as history data 2033a in the auxiliary memory unit 2033 of the data processing unit 203 via the light intensity measurement circuit 202.

[0034] (Example of Control of the Automated Analyzer 100 by the Controller 201) The amounts of components such as proteins, sugars, and lipids contained in the sample 101 are calculated, for example, by the following procedure. First, the controller 201 instructs the cleaning unit 114 to clean the reaction cell 108. Next, the controller 201 instructs the sample dispensing mechanism 110 to dispense a fixed amount of the sample 101 in the sample cup 102 into the reaction cell 108. Next, the controller 201 instructs the reagent dispensing mechanism 111 to dispense a fixed amount of the reagent 104 in the reagent bottle 105 into the reaction cell 108.

[0035] When dispensing each solution, the control unit 201 instructs the drive units of each disk to rotate the sample disk 103, the reagent disk 106, and the reaction disk 109. At this time, the sample cup 102, the reagent bottle 105, and the reaction cell 108 are positioned at predetermined dispensing positions according to the drive timing of the corresponding dispensing mechanism.

[0036] Next, the control unit 201 instructs the solution stirring unit 112 to stir the sample 101 and reagent 104 dispensed into the reaction cell 108, thereby generating a reaction solution 107. As the reaction disk 109 rotates, the reaction cell 108 containing the reaction solution 107 passes through a measurement position where an absorbance measurement unit 113 is disposed. Each time the reaction cell 108 passes through the measurement position, the amount of light transmitted through the reaction solution 107 is measured by the absorbance measurement unit 113. The measurement data is sequentially output to the auxiliary memory unit 2033 and accumulated as reaction process data.

[0037] During the accumulation of this reaction process data, if necessary, another reagent 104 is additionally dispensed into the reaction cell 108 by the reagent dispensing mechanism 111, stirred by the solution stirring unit 112, and further measured for a certain period of time. As a result, the reaction process data acquired at certain time intervals is stored in the auxiliary memory unit 2033.

[0038] (Operation of the Automated Analyzer 100) Figure 5 is a flowchart showing an example of the operation of the automated analyzer 100. When the automated analyzer 100 is powered on (S501), it starts a warm-up process (S502). The warm-up process includes starting up various software programs and checking the operation of each component before analysis. The time required for this warm-up process is called the warm-up time. In Figure 5, the processes from S502 to S507 correspond to the warm-up process.

[0039] The automated analyzer 100 turns on the LED light source 301 during the warm-up process (S503). It takes time (a predetermined time, for example, 30 minutes) for the light intensity of the light emitted from the LED light source 301 to stabilize after the LED light source 301 is turned on. The light from the LED light source 301 is not used for absorption analysis at least until the warm-up process is complete (until the LED light source 301 stabilizes). The maximum light intensity X is due to the start-up characteristics of the LED light source 301 and differs for each LED used in the LED light source 301. In this embodiment, attention is focused on the start-up characteristics of the LED light source 301, and the maximum light intensity X due to the start-up characteristics of the LED light source 301 is used to predict the state of the LED light source 301 and when to replace the LED light source 301.

[0040] The absorbance measurement unit 113 measures the light intensity of the LED light source 301 during the warm-up process (a period of 30 minutes from the start-up of the automated analyzer 100 (turning on of the LED light source 301)). Then, the data processing unit 203 calculates the maximum light intensity X based on the measured light intensity (S504).

[0041] The data processing unit 203 associates the calculated maximum light intensity X with the power-on time T of the LED light source 301 (the total power-on time up to the current startup of the automatic analyzer 100) and stores them in the history data 2033a (S505). The power-on time T of the LED light source 301 is stored, for example, in the auxiliary storage unit 2033 of the data processing unit 203. The data processing unit 203 acquires the power-on time T of the LED light source 301 stored in the auxiliary storage unit 2033, and associates the calculated maximum light intensity X with the acquired power-on time T of the LED light source 301 and stores them in the history data 2033a.

[0042] Then, the data processing unit 203 executes a state determination process (S506) to determine the state of the LED light source 301. Details of the state determination process will be described later (see FIG. 6).

[0043] The data processing unit 203 also executes a replacement time prediction process (S507) to predict when to replace the LED light source 301. Details of the replacement time prediction will be described later (see FIG. 7).

[0044] The automatic analyzer 100 of this embodiment executes both the status determination process (S506) and the replacement time prediction process (S507), but may execute only one of the status determination process (S506) or the replacement time prediction process (S507).

[0045] Once the warm-up process is complete and the automatic analyzer 100 is ready to perform analysis, the automatic analyzer 100 irradiates the reaction solution 107 with light from the LED light source 301 and starts absorbance analysis to measure the absorbance of the reaction solution 107 in the reaction cell 108 (S508).

[0046] (Method for Determining the State of the LED Light Source 301: Details of S506) Fig. 6 is a flowchart showing details of the state determination process. For example, the processor 2031 of the data processing unit 203 executes the state determination program 2033b stored in the auxiliary storage unit 2033, thereby executing each step of the flowchart in Fig. 6.

[0047] The data processing unit 203 compares the maximum light intensity X calculated in S504 with a preset reference value (a value that is set as a value that will not interfere with analysis) (S601). The reference value is stored in advance in, for example, the auxiliary storage unit 2033 of the data processing unit 203.

[0048] The data processing unit 203 determines whether the maximum light amount X is equal to or less than a reference value according to the comparison result of S601 (S602).

[0049] If it is determined that the maximum light intensity X is equal to or less than the reference value (S602: Yes), the data processing unit 203 identifies the state of the LED light source 301 (S603). For example, the data processing unit 203 may identify the state of the LED light source 301 based on the magnitude of the difference between the maximum light intensity X and the reference value, or may identify the state of the LED light source 301 based on the maximum light intensity X. The state of the LED light source 301 may be, for example, a degradation state indicating the degree of degradation of the LED light source 301, a usage state indicating the degree of use of the LED light source 301, or the like.

[0050] The data processing unit 203 outputs (displays) the identified state of the LED light source 301 to the output unit 205 (display) (S604).

[0051] On the other hand, if it is determined that the maximum light intensity X is greater than the reference value (S602: No), the data processing unit 203 outputs (displays) a warning on the output unit 205 (display) (S605). For example, the data processing unit 203 may display a warning on the output unit 205 (display) urging the user to replace the LED light source 301, or a warning indicating that it is time to replace the LED light source 301. The data processing unit 203 may also output, from the output unit 205 (lamp or speaker) that outputs the status of the LED light source 301, light or sound urging the user to replace the LED light source 301, or light or sound indicating that it is time to replace the LED light source 301. Receiving the warning allows the user to check whether there is a problem with the LED light source 301.

[0052] 6, although it is possible to perform the absorption analysis in S508 after the warning is output (S605), the performance of the absorption analysis in S508 may be prohibited when the warning is output. Alternatively, the analysis results of the absorption analysis performed after the warning is output may be managed separately from the analysis results of the absorption analysis performed without the warning.

[0053] In the process of FIG. 6, the state of the LED light source 301 is determined using the maximum light intensity X. However, the time t ｍａｘ and a preset time reference value t ＴＨ (S601'), and time t ｍａｘ is the time reference value t ＴＨ In the above case (the state in which the upper time limit in FIG. 10 has already been reached) (S602'), a warning may be output (S605).

[0054] (Method for predicting replacement time of LED light source 301) Fig. 7 is a flowchart showing details of the replacement time prediction process. For example, the processor of the data processing unit 203 executes the replacement time prediction program 2033c stored in the auxiliary storage unit 2033, thereby executing each step of the flowchart in Fig. 7.

[0055] First, the data processing unit 203 refers to the history data 2033a in the auxiliary storage unit 2033 (S701).

[0056] The data processing unit 203 obtains the maximum light intensity X for each power-on time T of the LED light source 301 from the history data 2033a, and derives an approximate line using the obtained maximum light intensity X for each power-on time T of the LED light source 301 (in the case of Example 1 described below) or the time t until the maximum light intensity X for each power-on time T (in the case of Example 2 described below) (S702). This approximate line is derived using the least squares method or the like. Note that, although linear approximation is performed in the example of FIG. 7, exponential approximation, logarithmic approximation, polynomial approximation, power approximation, or moving average approximation may also be performed. Furthermore, the accuracy of the approximation can be further improved by correcting the light intensity data by multiplying it by a coefficient based on environmental data such as temperature and humidity.

[0057] The data processing unit 203 predicts the replacement time of the LED light source 301 from the derived approximate line (S703). For example, the data processing unit 203 calculates the current-carrying time T until the approximate line reaches the upper limit of the maximum light intensity X, and sets the calculated current-carrying time T as the replacement time.

[0058] The data processing unit 203 then outputs (displays) the replacement timing to the output unit 205 (display) (S704). For example, the data processing unit 203 outputs (displays) the remaining power-on time until the LED light source 301 is replaced, the remaining operating time of the automated analyzer 100, the recommended replacement date and time for the LED light source 301, etc., to the output unit 205 (display).

[0059] (Effects of this embodiment) In this embodiment, by using the maximum light output X (rise-up characteristics) of the LED light source 301, it is possible to determine the condition of each individual LED light source 301 and predict when to replace it, while reflecting the state of the LED light source 301, which changes over time as the power is turned on. This reduces the replacement frequency of the LED light source 301, thereby reducing the maintenance costs required for light source replacement and reducing the workload of operators other than routine work. In addition, it reduces the number of light sources that are discarded because their operating time exceeds a certain time, even though they have sufficient light output, which also leads to a reduction in the environmental impact.

[0060] Furthermore, in this embodiment, unlike Patent Document 2, a new measurement system for monitoring the current and voltage applied to the LED light source 301 is not required.

[0061] Next, a method for determining the state of the LED light source 301, which is the light source unit, and predicting the replacement time will be described below with reference to Examples 1 and 2. In the present disclosure, the state of the LED light source 301 and the replacement time prediction are performed by utilizing the knowledge that the maximum light intensity from when the LED is turned on until the light intensity stabilizes varies depending on the power-on time of the LED light source 301.

[0062] Example 1 proposes predicting when to replace the LED light source 301 based on the phenomenon that the maximum light intensity from the LED light source 301 varies depending on the power-on time T of the LED until the intensity stabilizes. Therefore, the fluctuation in light intensity of the LED used in the light source unit (LED light source 301) from when it was turned on until the light intensity sufficiently stabilized was measured using an integrating sphere. Here, a white LED was used, which emits light over a broad wavelength band (approximately 370 nm to 800 nm) from a light-emitting chip that emits ultraviolet light and a phosphor placed on the light-emitting chip. To maintain a constant temperature of the LED, a Peltier element was used to control the temperature of the LED mounting board.

[0063] FIG. 8 shows the results of the light intensity fluctuations immediately after the white LED was turned on (120 seconds after turning it on) for each power-on time (4,000 hours, 7,000 hours, and 10,000 hours). The horizontal axis represents the time (seconds) since the LED was turned on, and the vertical axis represents the relative light intensity (%), where the light intensity at the start of power-on (power-on time 0) is 100%. In Example 1, the light intensity fluctuations during 120 seconds after the LED was turned on were used as an example of the light intensity fluctuations until the light intensity stabilized after a certain time had elapsed since the LED light source was turned on. Here, the light intensity from the LED light source was defined as stabilizing 30 minutes after turning it on, and the light intensity fluctuations during 120 seconds after turning it on were used, which was a much shorter period. However, the definitions of "after a certain time has elapsed" and "until the light intensity stabilizes" are not limited to these and may be determined depending on the size of the automated analyzer. For example, the certain time is much shorter than the warm-up time required for the automated analyzer 100 to be ready for measurement after startup. In this way, the state of the LED light source 301 can be determined and the replacement time can be predicted in the early stage of the warm-up time, thereby preventing a decrease in the throughput of the absorption analysis.

[0064] In Example 1, the maximum light intensity X was calculated for each power-on time T. In the example shown in Figure 8, the values ​​were 100.55%, 102.33%, and 102.83% at 4,000, 7,000, and 10,000 hours of power-on, respectively. Therefore, it was confirmed that the maximum light intensity from when the LED was turned on until the light intensity stabilized increased as the power-on time increased. Regarding wavelength, the light intensity fluctuation was 376±5 nm, which is close to the wavelength of the light-emitting chip that constitutes the white LED used in the automated analyzer. The above findings are believed to reflect the aging of both the light-emitting chip and the phosphor that constitute the white LED. The light-emitting chip and the phosphor are thought to aging at different rates, and it is presumed that the light emission from the phosphor is more likely to decrease with power-on than the light emission from the chip. Here, a portion of the light emitted from the chip is absorbed by the phosphor as excitation light, but it is believed that the phenomenon of an increase in the amount of light emitted at 376±5 nm, which is a wavelength relatively close to the wavelength of the chip, was confirmed as a result of the decrease in absorption by the phosphor as a result of the application of current. Therefore, it is desirable to limit the wavelength of the LED consisting of a light-emitting chip and a phosphor to a wavelength close to the wavelength of the light-emitting chip, as in Example 1.

[0065] Figure 9 shows the correlation between the LED power-on time T and the maximum light intensity X from when the LED is turned on until the light intensity stabilizes. As with the wavelength, the maximum light intensity X was calculated for fluctuations in light intensity at 376±5 nm, a wavelength close to the wavelength of the light-emitting chip. As with the results of Figure 8, the phenomenon of the maximum light intensity from when the LED is turned on until the light intensity stabilizes increasing with increasing power-on time was confirmed, indicating a roughly linear correlation between the LED power-on time T and the maximum light intensity X. Therefore, even for the LED light source 301 installed in an automated analyzer, as shown by the solid line in Figure 9, the correlation between the maximum light intensity X and the power-on time T can be expressed by an approximate straight line calculated from multiple actual data. From this approximate straight line, the power-on time T1 at which the maximum light intensity X exceeds a predetermined upper limit (the maximum light intensity value when the LED is in a state of deterioration that requires replacement) is calculated, and this T1 is determined as the replacement time. In some cases, the correlation coefficient may be higher with an approximate curve rather than an approximate straight line, so the method of calculating the correlation can be appropriately changed depending on the operation of each device. It is believed that there are individual differences in the initial light intensity and internal state of the LED element. In Example 1, by deriving the correlation between the maximum light intensity X and the energization time T from actual data for each LED used in the LED light source 301, it is possible to calculate the optimal replacement time for each individual LED, thereby reducing the replacement frequency of the LED light source 301.

[0066] Example 2 illustrates an example of predicting the replacement time based on the phenomenon that the time it takes for the light intensity from the LED light source 301 to stabilize and reach its maximum light intensity varies depending on the power-on time T of the LED. As in Example 1, a white LED was used, which emits light in a broadband wavelength range (approximately 370 nm to 800 nm) from a light-emitting chip that emits ultraviolet light and a phosphor placed on the light-emitting chip. The fluctuation in light intensity of the LED used in the light source unit (LED light source 301) from when it was turned on until the light intensity was sufficiently stabilized was measured using an integrating sphere. To maintain a constant temperature of the LED, a Peltier element was used to control the LED mounting substrate at a constant temperature.

[0067] Figure 10 shows the correlation between the LED power-on time T and the time t required to reach the maximum light intensity after the LED is turned on and stabilized. As with Example 1, the time t required to reach the maximum light intensity was calculated for a wavelength of 376±5 nm, which is close to the wavelength of the light-emitting chip. As a result, it was confirmed that the time t required to reach the maximum light intensity after the LED is turned on and stabilized increases with increasing power-on time. As with Example 1, this is likely due to aging of the light-emitting chip and phosphor, resulting in a characteristic change depending on the power-on time T. Therefore, this result indicates that there is a difference in the light intensity fluctuation when the LED is turned on depending on the power-on time, and this value can be used as a reference for determining when to replace the LED. For the LED light source 301 installed in an automated analyzer, the correlation between the time t required to reach the maximum light intensity and the power-on time T can be represented by an approximate straight line calculated from multiple actual data, as shown by the solid line in Figure 10. From this approximate line, the power-on time T1 at which the time t until the maximum light output exceeds a predetermined upper limit is calculated (when the approximate line function is expressed as time t = a × power-on time T + b, T obtained by substituting t = upper limit value is T1), and T1 can be set as the replacement time. Note that in some cases, the correlation coefficient may be higher with an approximate curve than with an approximate line, so the method of calculating the correlation can be appropriately changed depending on the operation of each device.

[0068] Furthermore, even if the maximum light intensity is equal to or less than the upper limit in Example 1, if the time taken to reach the maximum light intensity exceeds the upper limit in Example 2, the system may be configured to interrupt the absorption analysis. That is, by combining a comparison of the measured value of the maximum light intensity with the upper limit and a comparison of the measured value of the time taken to reach the maximum light intensity with the upper limit, it is possible to realize prediction of the replacement time in accordance with the analytical performance required for absorption analysis.

[0069] Example 3 demonstrates an example in which more accurate predictions are possible by correcting the light intensity data after lighting based on LED temperature data. It is known that the light-emitting efficiency and light intensity of an LED's light-emitting chip and phosphor change depending on the temperature of the mounting substrate and the ambient temperature. Because these changes in light-emitting efficiency and light intensity affect the stability of the light intensity, it is believed that highly accurate predictions are possible by acquiring the light intensity in a sufficiently stable temperature environment. In Example 3, to maintain a constant LED temperature, a Peltier element was used to control the LED mounting substrate at a constant temperature. Furthermore, the light intensity data after lighting of the LED was corrected based on temperature data acquired from a thermistor on the mounting substrate. As in Examples 1 and 2, a white LED was used, which emits light over a wide wavelength range (approximately 370 nm to 800 nm) from a light-emitting chip that emits ultraviolet light and a phosphor installed on the light-emitting chip. The fluctuations in light intensity of the LED used in the light source unit (LED light source 301) from lighting until the light intensity was sufficiently stabilized were measured using an integrating sphere.

[0070] FIG. 11 shows the results of the light intensity fluctuation after the white LED is turned on (1800 seconds after turning on) before and after data correction. The horizontal axis represents the time (sec) from when the LED is turned on, and the vertical axis represents the relative light intensity (%) when the light intensity 1800 seconds (30 minutes) after the LED is turned on is set to 100%. In Example 3, the light intensity from the LED light source is defined as stabilizing 30 minutes after turning on, and the light intensity fluctuation 1800 seconds after the LED is turned on is used as an example of the light intensity fluctuation until the light intensity stabilizes after a certain time has passed since the LED light source was turned on. As with Examples 1 and 2, the light intensity fluctuation of 376±5 nm, which is close to the wavelength of the light-emitting chip, is shown. The figure before correction also shows the temperature fluctuation after the LED is turned on. The horizontal axis represents the time (sec) from when the LED is turned on, and the vertical axis represents the temperature (°C) obtained from the thermistor on the mounting board.

[0071] In Example 3, a Peltier element was used to maintain a constant temperature on the LED mounting board, but the temperature of the thermistor on the mounting board fluctuated by approximately ±0.15°C (Figure 11(a)). Before data correction, a decrease in light intensity was confirmed after 480 seconds, when a rise in the temperature of the mounting board was observed. This is thought to be due to the fact that as the temperature of the LED element rises, the forward voltage decreases, causing a decrease in light emission efficiency, resulting in a decrease in the light intensity of 376±5 nm, which is close to the wavelength of the light-emitting chip.

[0072] To assess the condition or predict replacement timing using the LED light source's startup light intensity characteristics when turned on, it is essential to separate out the temperature-related light intensity fluctuations and evaluate only the startup light intensity fluctuations. The correlation between the mounting board temperature and light intensity for each wavelength is known from actual measurement data on the device. The light intensity fluctuation rate due to board temperature was calculated, and the "corrected" light intensity was evaluated assuming a constant board temperature. The light intensity fluctuation rate due to board temperature can be calculated by recording the mounting board temperature and light intensity when the light intensity stabilizes after a sufficient amount of time has passed since the LED light source was turned on, and then performing a linear approximation of the temperature change and the light intensity change.

[0073] The method for calculating the rate of change in light intensity due to temperature is not limited to this, and exponential approximation, logarithmic approximation, polynomial approximation, power approximation, or moving average approximation may also be used. Furthermore, the temperature variable used is not limited to the temperature of the mounting board, and the ambient temperature within the device or the temperature of peripheral components may also be used.

[0074] 11(b), it can be seen that the light intensity remains stable even after 480 seconds, when a drop in light intensity was observed before correction, and it is therefore possible to eliminate the influence of temperature. Such temperature-based data correction is extremely effective in accurately evaluating the initial light intensity immediately after the LED is turned on, which is used in the prediction method of the present disclosure, and is expected to further improve the accuracy of the approximation derivation.

[0075] Furthermore, in the third embodiment, correction is performed using temperature data, but it is also possible to correct the light quantity data by multiplying it by a coefficient based on environmental data such as humidity. Variations

[0076] (i) Modification 1 In the state determination process of this embodiment shown in FIG. 6, the state of the LED light source 301 is determined based on the comparison result between the reference value and the maximum light amount X (S601 → S602). However, the absolute value of the rate of change of the maximum light amount may be compared with a predetermined reference change rate threshold value, and the state determination may be performed based on the comparison result. In other words, the maximum light amount X at the time of the current device startup ｋ (Total power-on time T ｋ ) and the maximum light intensity X when the device was last started ｋ－１ (Total power-on time T until the last time the device was started ｋ－１ ), if the following formula is satisfied, the condition of the LED light source 301 may be deteriorating, so a warning may be output (S605). The warning is issued to deal with situations in which cracks may suddenly appear in the LED chip or phosphor.

[0077] |(X ｋ -X ｋ－１ ) / (T ｋ -T ｋ－１ ) | ≧ Reference change rate threshold

[0078] Upon receiving the warning, the user can interrupt the analysis by the automatic analyzer 100, check the LED light source 301 included in the automatic analyzer 100, and replace the LED light source 301 with a new LED light source if necessary.

[0079] (ii) Modification 2 In the above embodiment, the maximum light intensity X of the LED light source 301 or the time t until the maximum light intensity is reached is calculated during the warm-up process, and the state determination process and replacement time prediction process for the LED light source 301 are executed, but the timing for executing the state determination process and replacement time prediction process is not limited to during the warm-up process. For example, the state determination process and replacement time prediction process for the LED light source 301 may be executed during the maintenance mode, or the state determination process and replacement time prediction process for the LED light source 301 may be executed after a certain time has elapsed or after a certain number of inspections have been performed.

[0080] (iii) Other The technology of the present disclosure is not limited to the above-described embodiments, examples, and modifications, and includes various other modifications. The above-described embodiments and examples have been described in detail to clearly explain the present disclosure, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one example with the configuration of another example, and it is also possible to add the configuration of another example to the configuration of one example. Furthermore, it is possible to add, delete, or replace part of the configuration of each example with other configurations.

[0081] 101 Sample 102 Sample cup 103 Sample disk 104 Reagent 105 Reagent bottle 106 Reagent disk 107 Reaction solution 108 Reaction cell 109 Reaction disk 110 Sample dispensing mechanism 111 Reagent dispensing mechanism 112 Solution stirring unit 113 Absorbance measurement unit 114 Cleaning unit 115 Constant temperature fluid 201 Control unit 202 Light quantity measurement circuit 203 Data processing unit 2031 Processor 2032 Main memory unit 2033 Auxiliary memory unit 2033a History data 2033b Status determination program 2033c Replacement time prediction program 2034 Input / output I / F 204 Input unit 205 Output unit 301 LED light source 302 Spectrometer 3021 Diffraction grating 3022 Detector array 401 Optical axis 402 Light source side slit 403 Condenser lens 404 Spectrometer side slit

Claims

1. An analytical device comprising: an LED light source that irradiates light onto a liquid in a container that contains the liquid to be analyzed; a photodetector that detects light radiated from the liquid by irradiating the liquid with light from the LED light source; and a data processing unit that executes processing to determine the state of the LED light source based on (i) the maximum light intensity during the period from when the LED light source is turned on until a predetermined time has elapsed until the light intensity from the LED light source stabilizes, (ii) the time until the maximum light intensity is reached, or (iii) the rate of change of the maximum light intensity relative to the time the LED light source is turned on.

2. An analytical device according to claim 1, wherein the data processing unit further executes a process for predicting when to replace the LED light source based on the correlation between the maximum light intensity and the duration of time the LED light source is energized.

3. An analysis device according to claim 2, wherein the process of predicting when to replace the LED light source includes: a process of measuring the maximum light intensity for each power-on time of the LED light source; a process of deriving an approximate straight line from the maximum light intensity for each power-on time of the LED light source; and a process of predicting when to replace the LED light source based on the approximate straight line and a predetermined upper limit value of the maximum light intensity.

4. An analytical device according to claim 1, wherein the data processing unit further executes a process for predicting when to replace the LED light source based on the correlation between the time until the maximum light intensity is reached and the time the LED light source is energized.

5. An analysis device according to claim 4, wherein the process of predicting when to replace the LED light source includes: a process of measuring the time it takes for the LED light source to reach the maximum light intensity for each power-on time of the LED light source; a process of deriving an approximate straight line from the time it takes for the LED light source to reach the maximum light intensity for each power-on time of the LED light source; and a process of predicting when to replace the LED light source based on the approximate straight line and a predetermined upper limit value of the time it takes to reach the maximum light intensity.

6. An analytical device according to claim 1, wherein the LED light source has a light-emitting chip and a phosphor, and emits light in a wide wavelength range including the wavelength range from 370 nm to 800 nm.

7. An analytical device according to claim 1, wherein the photodetector is capable of measuring the amount of light of a plurality of wavelengths, and the wavelength used to measure the maximum amount of light is the wavelength closest to the wavelength of the light-emitting chip included in the LED light source.

8. An analytical device according to claim 1, wherein, when the light intensity after the predetermined time has elapsed since the LED light source was turned on is set to 100% and the stable light intensity is defined as the fluctuation in the light intensity being within 100±0.2%, the maximum light intensity is the largest value of the light intensity detected within the time until the definition of stable light intensity is met.

9. An analysis device according to claim 1, wherein the data processing unit further executes the following processes: calculating correlation data between environmental fluctuations in environmental data including the temperature and humidity of the LED light source and fluctuations in the light intensity of the LED light source; correcting the light intensity data of the LED light source based on the correlation data to generate an approximate straight line; and predicting when to replace the LED light source based on the approximate straight line and a predetermined upper limit value of the time required to reach the maximum light intensity.

10. A method for determining the state of an LED light source included in an analysis device, comprising: starting the analysis device and turning on the LED light source; measuring the light intensity of the LED light source using a measurement unit; calculating, using a computer, the maximum light intensity of the LED light source during a predetermined period from turning on the LED light source until the light intensity from the LED light source stabilizes; and determining, using the computer, the state of the LED light source based on (i) the maximum light intensity, (ii) the time required to reach the maximum light intensity, or (iii) the rate of change of the maximum light intensity relative to the time the LED light source is powered on.

11. The LED light source status determination method according to claim 10, further comprising: predicting, by the computer, when to replace the LED light source based on the correlation between the maximum light intensity and the power-on time of the LED light source.

12. A method for determining the state of an LED light source according to claim 11, wherein predicting the time to replace the LED light source includes: measuring the maximum light intensity for each time period that the LED light source is powered on; deriving an approximate straight line from the maximum light intensity for each time period that the LED light source is powered on; and predicting the time to replace the LED light source based on the approximate straight line and a predetermined upper limit value of the maximum light intensity.

13. The LED light source status determination method according to claim 10, further comprising: predicting, by the computer, when to replace the LED light source based on the correlation between the time until the maximum light intensity is reached and the time the LED light source has been powered on.

14. A method for determining the state of an LED light source according to claim 13, wherein predicting when to replace the LED light source comprises: measuring the time it takes for the LED light source to reach the maximum light intensity for each time that the LED light source is powered on; deriving an approximate straight line from the time it takes for the LED light source to reach the maximum light intensity for each time that the LED light source is powered on; and predicting when to replace the LED light source based on the approximate straight line and a predetermined upper limit value for the time it takes for the maximum light intensity to be reached.

15. The LED light source state determination method according to claim 10, wherein the LED light source has a light emitting chip and a phosphor, and emits light in a wide wavelength band including a wavelength range from 370 nm to 800 nm.

16. A method for determining the state of an LED light source as set forth in claim 10, wherein, when the light intensity after the predetermined time has elapsed since the LED light source was turned on is set to 100% and stable light intensity is defined as light intensity fluctuations falling within 100±0.2%, the maximum light intensity is the largest value of the light intensity detected within the time until the definition of stable light intensity is met.

17. A method for determining the state of an LED light source according to claim 10, further comprising: calculating correlation data between environmental fluctuations in environmental data including the temperature and humidity of the LED light source and fluctuations in the amount of light of the LED light source; correcting the light amount data of the LED light source based on the correlation data to generate an approximate straight line; and predicting the time to replace the LED light source based on the approximate straight line and a predetermined upper limit value of the maximum amount of light.

Images