Automated analyzer

Abstract

The purpose of the present invention is to provide: an automated analyzer which makes it possible to reduce the amount of a cleaning agent used for cleaning a reaction vessel or a dispensing probe; and a method for cleaning the automated analyzer. To this end, an automated analyzer according to the present invention comprises: a dispensing probe which suctions a liquid that contains a sample and discharges the liquid into a reaction vessel; a control unit which estimates the viscosity of the liquid; and a sensor which is used for estimation of the viscosity. The control unit changes the concentration of a cleaning agent that is used for cleaning of the reaction vessel or the dispensing probe on the basis of the estimated viscosity. A cleaning method according to the present invention includes: a step in which the control unit estimates the viscosity of the liquid on the basis of a value detected by the sensor during suction of the liquid; and a step in which the control unit changes the concentration of a cleaning agent that is used for cleaning of the reaction vessel or the dispensing probe on the basis of the estimated viscosity.

Description

automatic analyzer

[0001] This invention relates to an automated analyzer.

[0002] An automated analyzer is a device used to analyze the components contained in samples such as blood and urine. However, since the viscosity of the sample is not constant, if processes such as washing are performed under uniform conditions regardless of viscosity, the accuracy of the analysis may decrease. Therefore, automated analyzers that perform different controls according to the viscosity of the sample have been proposed. For example, Patent Document 1 discloses a technique in which viscosity information of the sample liquid is obtained based on the pressure measured by a pressure sensor for the liquid delivery pipe when the sample liquid is aspirated, and the pressure applied in processes such as washing is adjusted according to the viscosity information (Claim 3, paragraph 0027).

[0003] International Publication No. 2013 / 008502

[0004] The technology described in Patent Document 1 is intended to wash away impurities adsorbed on the solid-phase extractant, and is not intended to wash away impurities that occur when switching samples.

[0005] The object of the present invention is to provide an automated analyzer that can reduce the amount of detergent used for cleaning reaction vessels or dispensing probes.

[0006] To solve the aforementioned problems, the automated analyzer of the present invention comprises a dispensing probe that aspirates a liquid containing a sample and discharges it into a reaction vessel, a control unit that estimates the viscosity of the liquid, and a sensor used for viscosity estimation. The control unit changes the concentration of the detergent used to clean the reaction vessel or the dispensing probe based on the estimated viscosity.

[0007] According to the present invention, an automated analyzer can be provided that can reduce the amount of detergent used for cleaning reaction vessels or dispensing probes. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

[0008] A schematic diagram showing the overall configuration of the automated analyzer. A schematic diagram showing the configuration of the sample dispensing mechanism. A schematic diagram showing the flow path of the sample dispensing mechanism. A functional block diagram of the control system in the automated analyzer. A flowchart showing the cleaning method of the reaction vessel in Example 1. A diagram showing the pressure waveform during sample aspiration. A table showing the amount of each liquid supplied to the reaction vessel for each viscosity of the mixed solution. A flowchart showing the cleaning method of the reaction vessel in Example 2. A flowchart showing the cleaning method of the dispensing probe in Example 4.

[0009] Embodiments of the present invention will be described below with reference to the drawings.

[0010] Figure 1 is an overall schematic diagram showing the configuration of the automated analyzer. The automated analyzer of this embodiment uses bodily fluid components such as blood and urine as samples and measures various components such as sugar, cholesterol, protein, and enzymes. As shown in Figure 1, the automated analyzer comprises a sample disc 2, a reagent disc 3, a reaction disc 4, a sample dispensing mechanism 5, a reagent dispensing mechanism 6, a stirring mechanism 7, a photometric mechanism 8, a washing tank 9 (for the sample dispensing mechanism), a washing tank 10 (for the reagent dispensing mechanism), and a washing mechanism 11 for washing the reaction vessel.

[0011] The sample disk 2 supports the sample container holder 16 on which the sample container 15 containing the sample is mounted, and rotates by a rotational drive mechanism (not shown). The reagent disk 3 supports the reagent cooling holder 20 on which the reagent container 18 and detergent container 19 are mounted, maintaining the reagents and detergents at a constant temperature, and also rotates by a rotational drive mechanism (not shown). The reaction disk 4 supports the reaction vessel holder 23 on which the reaction vessel 22 is mounted, and rotates by a rotational drive mechanism (not shown). The sample disk 2, reagent disk 3, and reaction disk 4 are circular, and as their respective rotational drive mechanisms operate, the sample container 15, reagent container 18, detergent container 19, and reaction vessel 22 move to their predetermined positions.

[0012] The automatic analyzer also includes an operation unit 12, an interface 40, a control computer 13 (control unit), and a data storage unit 14. The operation unit 12 includes an input unit 121 such as a keyboard or a mouse used when requesting a measurement, a display unit 122 such as a liquid crystal display for outputting the analysis result of measurement data, and an operation computer 120 connected to the input unit 121 and the display unit 122. Note that the input unit 121 and the display unit 122 may be integrally configured, such as a touch panel.

[0013] The operation computer 120 is connected to the control computer 13 via the interface 40. Also, information such as reagent identification information, sample identification information, analysis parameters, analysis item request content, calibration results, and measurement results is stored in the data storage unit 14 connected to the interface 40. In the following, the control computer 13 will be described as controlling the entire automatic analyzer including each component, but a control device independently provided for each component may control each of them, or the operation computer 120 may execute some control.

[0014] FIG. 2 is a schematic diagram showing the configuration of the sample dispensing mechanism. As shown in FIG. 2, the sample dispensing mechanism 5 includes a sample dispensing probe 25, a support shaft 26, an arm 27, an up-and-down drive unit 28, a rotation drive unit 29, and a temperature measurement unit 30. By operating the up-and-down drive unit 28 and the rotation drive unit 29, the sample dispensing probe 25 can access the sample container 15 (suction position), the reaction container 22 (discharge position), and the washing tank 9, respectively. The temperature measurement unit 30 may be any sensor that can measure the temperature of the sample in the sample container 15, regardless of whether it is non-contact type or contact type.

[0015] Note that the reagent dispensing mechanism 6 also has the same configuration as the sample dispensing mechanism 5. The reagent dispensing probe can access the reagent container 18 (first suction position), the detergent container 19 (second suction position), the reaction container 22 (discharge position), and the washing tank 10, respectively.

[0016] Figure 3 is a schematic diagram showing the flow path of the sample dispensing mechanism. As shown in Figure 3, the sample dispensing mechanism 5 includes a dispensing syringe 32, a tube 33, a pressure detector 34, a solenoid valve 35, and a cleaning pump 36. The dispensing syringe 32 includes a plunger 37 and is connected to the sample dispensing probe 25 via the tube 33. When the plunger 37 of the dispensing syringe 32 reciprocates, the pressure in the flow path changes, and suction and discharge of the sample are performed. The flow path is filled with pure water called system water. Further, since the pressure detector 34 is provided in the middle of the flow path connecting the dispensing syringe 32 and the sample dispensing probe 25, it is possible to detect the pressure change during suction and discharge of the sample. When a predetermined pressure change is detected, it is determined that an abnormality such as air suction or clogging has occurred in the sample dispensing probe 25.

[0017] The reagent dispensing mechanism 6 also has the same configuration as the sample dispensing mechanism 5. The pressure detector of the reagent dispensing mechanism 6 detects the pressure when the reagent dispensing probe sucks or discharges the reagent. Similar to the pressure detector of the sample dispensing mechanism 5, the pressure detector of the reagent dispensing mechanism 6 can determine the presence or absence of an abnormality in the reagent dispensing probe by detecting a pressure change.

[0018] Figure 4 is a functional block diagram of the control system in the automatic analyzer. As shown in Figure 4, the control computer 13 includes a processor 130 and a memory 131. The processor 130 is, for example, a CPU. Programs corresponding to the respective functions executed by the processor 130 are conceptually stored as a mechanism control unit 132, an analysis unit 133, a viscosity estimation unit 134, and a detergent concentration determination unit 135 in the memory 131. The mechanism control unit 132 controls the operations of various mechanisms such as the sample dispensing mechanism 5 and the reagent dispensing mechanism 6. The analysis unit 133 analyzes the measurement data. The viscosity estimation unit 134 estimates the viscosity of the liquid containing the sample, and the details will be described later. The detergent concentration determination unit 135 determines the concentration of the detergent used for cleaning the reaction vessel 22 or the dispensing probe, and the details will be described later.

[0019] Here, the program may be provided pre-installed on ROM or similar media, or provided or distributed as an installable or executable file recorded on a computer-readable storage medium such as a CD-ROM. Furthermore, the program may be stored on a computer connected to a network such as the Internet and provided or distributed by downloading it via the network.

[0020] When a user requests a measurement via the input unit 121, the mechanism control unit 132 operates each mechanism and the measurement begins. The obtained measurement data is stored in the data storage unit 14 and analyzed by the analysis unit 133. The automated analyzer mainly performs the following operations: sample dispensing, washing of the dispensing probe, reagent dispensing, stirring, photometry, and washing of the reaction vessel.

[0021] First, the sample dispensing operation will be explained. Multiple sample containers 15, arranged in a circular pattern on the sample disk 2, move to the position where they will be aspirated by the sample dispensing probe 25, according to the order in which the samples to be analyzed will be processed. The sample dispensing mechanism 5 also aspirates samples from the sample containers 15, and the rotation drive unit 29 drives the sample dispensing probe 25 from its initial position to above the sample containers 15. Then, the vertical drive unit 28 lowers the tip of the sample dispensing probe 25 into the sample, and the sample dispensing mechanism 5 aspirates a predetermined amount of sample according to the control by the mechanism control unit 132 of the control computer 13. Next, the vertical drive unit 28 raises the sample dispensing probe 25 to its upper limit, and the rotation drive unit 29 moves the sample dispensing probe 25 from above the sample containers 15 to above the reaction vessel 22. Then, the vertical drive unit 28 lowers the tip of the sample dispensing probe 25 until it touches the bottom surface of the reaction vessel 22, and the sample dispensing mechanism 5 dispenses a predetermined amount of sample.

[0022] Next, the cleaning operation of the dispensing probe will be explained. After dispensing the sample, the sample dispensing probe 25 moves to the cleaning tank 9. In the cleaning tank 9, the sample dispensing probe 25 descends, and system water is discharged from the cleaning tank 9 to clean the outer wall of the sample dispensing probe 25. Also, as the sample dispensing probe 25 descends, the cleaning pump 36 sends system water, and the solenoid valve 35 opens, discharging the system water along with any remaining sample inside the sample dispensing probe 25. System water refers to purified water supplied from the pure water system to the water tank of the automated analyzer, which fills the flow path and pipettes.

[0023] Next, the reagent dispensing and stirring operations will be described. The reaction vessel 22, to which the sample or diluted sample (see Example 2 below) has been added, moves to the reagent dispensing position as the rotation drive mechanism of the reaction disk operates. A predetermined amount of reagent, aspirated from the reagent container 18, is dispensed into the moved reaction vessel 22 by the reagent dispensing probe. After the reagent is dispensed, the reaction vessel 22 moves to the stirring position of the stirring mechanism 7, and stirring is performed.

[0024] Next, the photometric operation will be explained. The reaction vessel 22, in which the mixture of the sample and reagent is stirred, passes through a beam of light emitted from the light source of the photometric mechanism 8. The absorbance at this time is detected by the photometric mechanism 8, which is a multi-wavelength photometer. The signal indicating the absorbance detected by the photometric mechanism 8 is input to the control computer 13 and converted into a measurement value for the sample. The mixture in the reaction vessel 22 is photometrically measured each time it passes through the photometric mechanism 8, and the reaction process, which is the change in absorbance over time, is recorded. In addition, the analysis unit 133 of the control computer 13 processes the photometric data and also makes an abnormality determination of the sample, reagent, or reaction process based on the absorbance.

[0025] Finally, the cleaning operation of the reaction vessel 22 will be described. The cleaning mechanism 11 cleans the reaction vessel 22 by sucking up the mixed liquid or discharging system water.

[0026] To prevent sample and reagent carryover, the dispensing probe and reaction vessel 22 must be washed not only with water (hereinafter sometimes referred to as normal washing) but also with detergent (hereinafter sometimes referred to as special washing). Whether or not special washing is necessary is determined based on the type of sample and the measurement item. For example, if the sample is whole blood, special washing is performed if the measurement item is highly susceptible to carryover. The following explanation assumes that special washing is necessary.

[0027] In automated analyzers, samples adhering to the sample dispensing probe 25, reaction vessel 22, and stirring mechanism 7 are more likely to remain even after washing if their viscosity is high, compared to samples with low viscosity or near-water consistency. Therefore, it is desirable to specially clean reaction vessels 22 and other parts adhering to high-viscosity samples using a high-concentration detergent. On the other hand, since samples with low viscosity or near-water consistency can be cleaned with low-concentration detergents, cleaning them with the same detergent concentration as high-viscosity samples would result in excessive detergent consumption.

[0028] There are three main mechanisms for cleaning: separation-type cleaning, dissolution-type cleaning, and decomposition-type cleaning. Separation-type cleaning involves applying surfactants or other substances to the interface between contaminants and the contaminated material to weaken their adhesion and separate them. Dissolution-type cleaning involves dissolving contaminants in a cleaning solution. Separation-type cleaning involves the cleaning solution acting on the chemical bonds of the contaminants, decomposing the contaminant molecules themselves. In practice, cleaning is performed by one or more of the above mechanisms. Of the above cleaning mechanisms, separation-type cleaning and decomposition-type cleaning do not differ significantly in cleaning effect if the final concentration of the detergent component exceeds the critical micelle concentration. On the other hand, for dissolution-type cleaning, since it changes the intermolecular forces and polarity of the contaminants, it is necessary to increase the amount of detergent according to the amount of contaminants. Contaminants for which dissolution-type cleaning is effective include lipids, cholesterol, and proteins in plasma. There is a correlation between the concentration of these contaminants and the viscosity of the sample. Therefore, if these contaminants are present in small amounts and the final concentration of the detergent component exceeds the critical micelle concentration, the detergent concentration can be reduced.

[0029] Therefore, in this embodiment, the viscosity of the sample is estimated, and the concentration of the detergent used for special cleaning is changed based on the estimated viscosity. Specifically, the viscosity of the sample is first estimated by the pressure value when the sample dispensing mechanism 5 aspirates the sample from the sample container, and then the viscosity of the mixture of the sample and reagent in the reaction vessel is estimated, thereby determining the concentration of the detergent used to clean the reaction vessel.

[0030] Figure 5 is a flowchart showing the method for cleaning the reaction vessel in Example 1. The user sends a measurement start command from the operation computer 120 to the control computer 13 using the input unit 121 of the operation unit 12. When measurement starts, as described above, the sample dispensing mechanism 5 aspirates the sample from the sample container 15 and discharges the sample into the predetermined reaction vessel 22. At this time, the pressure detector 34 acquires pressure data when the sample is aspirated by the sample dispensing mechanism 5 (step S101).

[0031] Here, we will explain how pressure data is acquired. Before sample aspiration, the control computer 13 sends an instruction to the pressure detector 34 to start monitoring the pressure in the probe. The pressure detector 34 then acquires pressure data during and immediately before and after the aspiration operation of the dispensing syringe 32 at regular time intervals. The pressure data acquired by the pressure detector 34 is stored in the data storage unit 14. In addition, during sample aspiration, the temperature measurement unit 30 acquires the temperature information of the sample. The data storage unit 14 stores pressure data, sample dispensing volume, sample aspiration operation time, and temperature information for each reaction vessel.

[0032] Next, the viscosity estimation unit 134 estimates the viscosity of the sample in the reaction vessel 22 (step S102). The method for estimating the viscosity of the sample will be described in detail below.

[0033] The pressure value before sample aspiration is P ０ The peak pressure value during sample aspiration is P ｓ In this case, to eliminate the influence of the sample before aspiration, P ｓ -P ０ The result P is calculated. ｓ０is used for viscosity estimation as the pressure value during sample aspiration. Also, the sample aspiration operation time stored in the data storage unit 14 (the operation time T of the dispensing syringe 32 when the sample dispensing probe 25 aspirates the sample) ｓ is also used for viscosity estimation.

[0034] Fig. 6 is a diagram showing the pressure waveform during sample aspiration. The total time of (a), (b), and (c) in Fig. 6 is the operation time T of the dispensing syringe 32 ｓ and the peak of each waveform in Fig. 6 is the pressure value P ｓ０ . Note that (a) is the time until the motor of the dispensing syringe 32 accelerates from the start pulse speed to the movement pulse speed, (b) is the time of the movement pulse speed, and (c) is the time until the motor decelerates from the movement pulse speed to the start pulse speed.

[0035] At this time, the viscosity μ of the sample is calculated as follows in Equation (1) based on the above-mentioned operation time T ｓ and the pressure value P ｓ０ .

[0036]

[0037] Then, for each reaction vessel 22 from which the sample is discharged, the viscosity μ of the sample during aspiration is calculated and stored in the data storage unit 14. Note that inside the reaction vessel 22, the mechanism control unit 132 controls a temperature control mechanism (not shown) to maintain a temperature different from that of the sample container 15. Here, since it is known that the viscosity changes with temperature, the viscosity of the sample during aspiration and the sample inside the reaction vessel 22 are different. Let the temperature of the liquid be t, a predetermined coefficient be b (a constant value in this embodiment), and the viscosity of the liquid at the reference temperature be μ ０ . Then, the viscosity μ t of the liquid at temperature t is represented by the following Equation (2) according to the Reynolds equation.

[0038]

[0039] Therefore, in this embodiment, based on the temperature information acquired by the temperature measurement unit 30, the viscosity of the sample during aspiration is corrected to the viscosity of the sample inside the reaction vessel 22. Specifically, the temperature of the sample during aspiration is t ｓ °C, and the temperature of the sample inside the reaction vessel 22 is tｖ The viscosity of the sample is calculated from the temperature (°C) and the pressure value during aspiration in μm. ｓ Therefore, the viscosity of the sample in the reaction vessel 22 is μ ｓｖ This can be expressed by the following (Equation 3).

[0040]

[0041] Since both the sample and reagents are dispensed into the reaction vessel 22, the pressure sensor of the reagent dispensing mechanism acquires pressure data when the reagent is aspirated by the reagent dispensing mechanism 6 (step S103). The method for acquiring pressure data is the same as in the case of reagent aspiration described above. The data storage unit 14 stores pressure data, reagent dispensing volume, reagent aspiration operation time, and temperature information for each reaction vessel. The reagents are stored in the reagent cooling holder 20 and are controlled by the control computer 13 to maintain a constant temperature.

[0042] Next, the viscosity estimation unit 134 estimates the viscosity of the reagent in the reaction vessel 22 (step S104). The method for estimating the viscosity of the reagent is the same as in the case of the sample described above. Specifically, the temperature of the reagent at the time of aspiration (temperature of the reagent cooling holder 20) is used. ｒ °C, the temperature of the reagents in reaction vessel 22 is t ｖ The viscosity of the reagent is calculated from the temperature (°C) and the pressure value during aspiration in μm. ｒ Therefore, the viscosity of the reagent in the reaction vessel 22 is μ. ｒｖ This can be expressed by the following (Equation 4).

[0043]

[0044] Next, the viscosity estimation unit 134 uses the data stored in the data storage unit 14 for each reaction vessel 22, specifically, μ ｓｖ , μ ｒｖ The viscosity μ of the sample-reagent mixture in the reaction vessel 22 is determined using the sample dispensing volume and the reagent dispensing volume. ｖ Estimate (step S105).

[0045] Subsequently, the detergent concentration determination unit 135 determines the viscosity of the mixed liquid μ v However, the threshold μ stored in the data storage unit 14 n Determine whether the above is true or not (step S106).

[0046] In step S106, the viscosity μ of the mixed liquid v ≥ threshold μ n If this is determined, the detergent concentration determination unit 135 decides not to change the concentration of the detergent used for special cleaning of the reaction vessel 22, that is, not to dilute the detergent (step S107). If the detergent is not diluted, the mechanism control unit 132 controls the reagent dispensing probe to aspirate a specified amount of detergent (step S108). Subsequently, the mechanism control unit 132 controls the reagent dispensing probe to discharge the aspirated detergent into the reaction vessel 22 (step S109).

[0047] On the other hand, in step S106, the viscosity of the mixed liquid μ v <Threshold μ n If this determination is made, the detergent concentration determination unit 135 decides to change the concentration of the detergent used for special cleaning of the reaction vessel 22, that is, to dilute the detergent (step S110). When diluting the detergent, the detergent concentration determination unit 135 determines the amount of detergent W and the amount of system water (diluent) Sys as follows.

[0048] First, the amount of detergent W is expressed by the following (Equation 5), where V is the maximum liquid volume of the reaction vessel and S is the sample dispensing volume.

[0049]

[0050] Next, the system water volume Sys is expressed as follows (Equation 6), where R is the reagent dispensing volume.

[0051]

[0052] Here, threshold μ ｎ Using the case where = 10 as an example, we will specifically explain how to determine the amount of detergent and system water used for cleaning. Figure 7 is a table showing the amount of each liquid supplied to the reaction vessel for each viscosity of the mixed liquid. As shown in Figure 7, 1 ≤ μ v In the range of <10, the viscosity of the mixed solution μ v To change the detergent concentration (detergent dilution ratio) accordingly, the amount of detergent W and the system water volume Sys change. Meanwhile, μ v < 1 and 10 ≤ μ vWithin this range, the detergent concentration (detergent dilution ratio) is not changed, so the detergent amount W and system water amount Sys remain constant. However, the method for determining the amounts of detergent and system water is not limited to this, and the threshold μ n It is also possible to set multiple values.

[0053] Once the amounts of detergent and system water are determined, the mechanism control unit 132 first controls the reagent dispensing probe to aspirate the determined amount of system water (step S111). Next, the mechanism control unit 132 controls the reagent dispensing probe to aspirate the determined amount of detergent (step S112). Subsequently, the mechanism control unit 132 controls the reagent dispensing probe to discharge the diluted detergent, consisting of the aspirated system water and detergent, into the reaction vessel 22 (step S113). The reaction vessel 22 is then cleaned by the stirring mechanism 7 and the cleaning mechanism 11.

[0054] According to this embodiment, since the detergent concentration can be changed according to viscosity, the amount of detergent used can be reduced compared to washing with a constant detergent concentration suited to high-viscosity samples. As a result, not only is the risk of detergent remaining in the reaction vessel reduced, but the progression of deterioration of the reaction vessel and flow path can also be slowed down. Furthermore, it is possible to reduce the environmental burden caused by detergent and the burden on the user of detergent replacement.

[0055] Furthermore, in this embodiment, the viscosity of the sample is corrected using the temperature information of the sample at the time of aspiration, resulting in high accuracy in viscosity estimation. In addition, in this embodiment, viscosity is estimated using a pressure detector provided to detect abnormalities in dispensing, eliminating the need to add special sensors and thus suppressing cost increases.

[0056] In this embodiment, the explanation was based on the premise that special cleaning using detergent is necessary, but a step may be included to determine whether special cleaning is necessary based on the viscosity of the sample. For example, if the viscosity of the sample is lower than a predetermined value, it is possible to further reduce the amount of detergent used by performing only normal cleaning using system water.

[0057] Example 2 is similar to Example 1 in terms of the general configuration of the automated analyzer, but differs from Example 1 in that it uses a diluted sample (diluted sample) obtained by diluting the sample for measurement.

[0058] In Example 2, first, the sample dispensing mechanism 5 dispenses the sample from the sample container 15 into the reaction vessel 22 (first reaction vessel). Then, the reagent dispensing mechanism 6 adds the diluent to the first reaction vessel. The diluent is assumed to be system water, but other liquids may be used. Next, the stirring mechanism 7 stirs the contents of the first reaction vessel to obtain a uniform diluted sample. Then, the sample dispensing mechanism 5 aspirates the diluted sample from the first reaction vessel and discharges it into another reaction vessel 22 (second reaction vessel). Next, the reagent dispensing mechanism 6 aspirates the reagent from the reagent container 18 and discharges it into the second reaction vessel.

[0059] In this case, reagents are also discharged into the second reaction vessel in addition to the diluted sample. However, since the sample is sufficiently diluted in the mixture in the second reaction vessel, special cleaning of the second reaction vessel is not necessarily required. Therefore, in Example 2, special cleaning is performed only on the first reaction vessel. Note that the viscosity of the diluted sample in the first reaction vessel is determined by the pressure value when the sample dispensing mechanism 5 aspirates the diluted sample from the first reaction vessel; therefore, it is not necessary to detect the pressure value when the sample dispensing mechanism 5 aspirates the sample from the sample container.

[0060] Figure 8 is a flowchart showing the method for cleaning the reaction vessel in Example 2. First, the pressure sensor 34 acquires pressure data when the sample dispensing mechanism 5 aspirates the diluted sample from the first reaction vessel (step S201). The pressure value before aspirating the diluted sample is P ０ The peak pressure value when aspirating the diluted sample is P Ｄ In this case, to eliminate the influence of the diluted sample before aspiration, P Ｄ -P ０ The result P is calculated. Ｄ０ This value is stored in the data storage unit 14 as the pressure value when the diluted sample is aspirated. Also, the aspiration time of the diluted sample (the operating time T of the dispensing syringe 32 when the sample dispensing probe 25 aspirates the diluted sample) is stored. Ｄ ) are also stored in the data storage unit 14.

[0061] Next, the viscosity estimation unit 134 estimates the viscosity of the diluted sample in the first reaction vessel (step S202). Viscosity μ of the diluted sample Ｄ This refers to the aforementioned operating time T Ｄand pressure value P Ｄ０ Therefore, it is calculated as shown in (Equation 7) below.

[0062]

[0063] Subsequently, the detergent concentration determination unit 135 determines the viscosity μ of the diluted sample. Ｄ However, the threshold μ stored in the data storage unit 14 n It is determined whether or not the result is greater than or equal to the above (step S203). The procedures from steps S204 to S210 that follow are the same as the procedures from steps S107 to 113 in Example 1.

[0064] Example 3 assumes that the temperature of the sample is equivalent to the room temperature of the location where the automated analyzer is installed, and differs from Example 1 in that the sample dispensing mechanism 5 is not equipped with a temperature measuring unit 30. In Example 3, a temperature measuring unit installed near the sample disk stores the room temperature measured during sample aspiration as temperature information in the data storage unit 14, and based on this temperature information, the viscosity estimation unit 134 corrects the viscosity of the sample at the time of aspiration to the viscosity of the sample in the reaction vessel 22. If the room temperature is always constant, the user may register the room temperature using the input unit 121 and fix the temperature of the sample at the time of aspiration.

[0065] Example 4 is similar to Example 1 in terms of the general configuration of the automated analyzer, but differs from Example 1 in that it allows not only the reaction vessel 22 but also the detergent concentration used for special cleaning of the sample dispensing probe 25 to be changed.

[0066] In Example 4, in addition to the sample container 15 for containing the sample, a sample container 15 for containing detergent is also placed on the sample disk 2. The user then operates the input unit 121 to set the system to perform special cleaning of the sample dispensing probe 25 for measurement items that are highly affected by carryover.

[0067] Figure 9 is a flowchart showing the method for cleaning the dispensing probe in Example 4. First, when measurement is started, the sample dispensing mechanism 5 aspirates the sample from the sample container 15 and discharges the sample into a predetermined reaction vessel 22. At this time, the pressure detector 34 acquires the pressure data when the sample is aspirated by the sample dispensing mechanism 5 (step S401). The pressure value before sample aspiration is P ０ The peak pressure value during sample aspiration is P ｆ In this case, to eliminate the influence of the sample before aspiration, P ｆ -P ０ The result P is calculated. ｆ０ This is stored in the data storage unit 14 as the pressure value at the time of sample aspiration. Also, the sample aspiration operation time (the operating time T of the dispensing syringe 32 when the sample dispensing probe 25 aspirations the sample) is stored. ｆ ) are also stored in the data storage unit 14.

[0068] Next, the viscosity estimation unit 134 estimates the viscosity of the sample (step S402). ｆ This refers to the aforementioned operating time T ｆ and pressure value P ｆ０ Therefore, it is calculated as shown in (Equation 8) below.

[0069]

[0070] Subsequently, the detergent concentration determination unit 135 determines the viscosity μ of the sample. ｆ However, the threshold μ stored in the data storage unit 14 nｆ Determine whether the above is true or not (step S403).

[0071] In step S403, the sample viscosity μ ｆ ≥ threshold μ nｆ If this is determined, the detergent concentration determination unit 135 decides not to change the concentration of the detergent used for special cleaning of the sample dispensing probe 25, that is, not to dilute the detergent (step S404). If the detergent is not diluted, the mechanism control unit 132 controls the sample dispensing probe 25 to aspirate a specified amount of detergent after the sample is dispensed (step S404) and to perform special cleaning of the sample dispensing probe 25 (step S406).

[0072] On the other hand, in step S403, the sample viscosity μｆ <Threshold μ nｆ If this determination is made, the detergent concentration determination unit 135 decides to change the concentration of the detergent used for special cleaning of the sample dispensing probe 25, that is, to dilute the detergent (step S407). In this case, the detergent concentration determination unit 135 determines the amount of detergent and system water (diluent). Next, the mechanism control unit 132 controls the sample dispensing probe 25 to aspirate the determined amount of system water after the sample is dispensed (step S408). After that, the mechanism control unit 132 controls the sample dispensing probe 25 to aspirate the determined amount of detergent (step S409) and perform special cleaning of the sample dispensing probe 25 (step S410).

[0073] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, in the embodiments described above, viscosity was estimated based on the pressure value when the liquid was aspirated using a pressure detector, but viscosity may be estimated using other sensors such as conductivity sensors, or viscosity may be detected directly using a viscosity sensor.

[0074] 2...Sample disc, 3...Reagent disc, 4...Reaction disc, 5...Sample dispensing mechanism, 6...Reagent dispensing mechanism, 7...Stirring mechanism, 8...Photometric mechanism, 9...Washing tank (for sample dispensing mechanism), 10...Washing tank (for reagent dispensing mechanism), 11...Washing mechanism, 12...Operation unit, 13...Control computer, 14...Data storage unit, 15...Sample container, 16...Sample container holder, 18...Reagent container, 19...Detergent container, 20...Reagent cooling holder, 22...Reaction vessel, 23...Reaction vessel holder, 25...Sample Dispensing probe, 26...Support shaft, 27...Arm, 28...Up / down drive unit, 29...Rotation drive unit, 30...Temperature measurement unit, 32...Dispensing syringe, 33...Tube, 34...Pressure detector, 35...Solenoid valve, 36...Washing pump, 37...Plunger, 40...Interface, 120...Operating computer, 121...Input unit, 122...Display unit, 130...Processor, 131...Memory, 132...Mechanism control unit, 133...Analysis unit, 134...Viscosity estimation unit, 135...Detergent concentration determination unit

Claims

1. An automated analyzer comprising: a dispensing probe that aspirates a liquid containing a sample and discharges it into a reaction vessel; a control unit that estimates the viscosity of the liquid; and a sensor used for viscosity estimation, wherein the control unit changes the concentration of the detergent used to clean the reaction vessel or the dispensing probe based on the estimated viscosity.

2. An automated analyzer according to claim 1, wherein the sensor is a pressure detector that detects the pressure inside the dispensing probe, and the control unit estimates the viscosity of the liquid at the time of aspiration based on the pressure value detected by the pressure detector at the time of aspiration.

3. An automatic analyzer according to claim 2, comprising: a temperature measuring unit for measuring the temperature of the sample in a sample container; and a temperature control mechanism for maintaining the liquid in the reaction vessel at a predetermined temperature, wherein the control unit corrects the viscosity of the liquid at the time of aspiration to the viscosity of the liquid in the reaction vessel based on the temperature measured by the temperature measuring unit, and changes the concentration of the detergent used to clean the reaction vessel based on the corrected viscosity.

4. An automatic analyzer according to claim 1, wherein the control unit dilutes the detergent using different amounts of diluent according to the viscosity when the estimated viscosity is lower than a predetermined threshold, and does not dilute the detergent when the estimated viscosity is equal to or greater than the threshold.

5. An automated analyzer according to claim 2, further comprising a temperature control mechanism for maintaining the liquid in the reaction vessel at a predetermined temperature, wherein the reaction vessel comprises a first reaction vessel containing a sample dispensed from a sample container and a diluent for diluting the sample, and a second reaction vessel containing a diluted sample dispensed from the first reaction vessel and a reagent dispensed from a reagent container, wherein the control unit estimates the viscosity of the diluted sample at the time of aspiration based on the pressure value detected when the diluted sample is aspirationed, and changes the concentration of the detergent used to clean the first reaction vessel based on the estimated viscosity.

6. An automated analyzer according to claim 1, wherein the control unit, when the estimated viscosity is lower than a predetermined threshold, causes the detergent and diluent to be drawn into the dispensing probe to clean the dispensing probe, and when the estimated viscosity is equal to or greater than the threshold, causes the detergent to be drawn into the dispensing probe to clean the dispensing probe.

7. A method for cleaning an automated analyzer in which a dispensing probe aspirates a liquid containing a sample and discharges it into a reaction vessel, comprising the steps of: a control unit estimating the viscosity of the liquid based on a value detected by a sensor when the liquid is aspirated; and the control unit changing the concentration of a detergent used to clean the reaction vessel or the dispensing probe based on the estimated viscosity.

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