Abstract:
The automatic analyzer uses a sample pipetted into a sample vessel to perform analysis, the sample vessel being repeatedly cleaned and used. In order to prevent contamination of the sample vessel, which is caused by the measurement of general biologically-derived samples, from influencing the analysis, the automatic analyzer uses a specified sample vessel to measure a standard solution so that the calibration of each analysis item is carried out. The automatic analyzer does not use the sample vessel in question for analysis of other biologically-derived samples.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an automatic analyzer for analyzing components of biologically-derived samples such as blood and urine and more particularly to an automatic analyzer that includes a sample-vessel holding mechanism capable of holding a plurality of sample vessels each of which holds a sample. 
         [0003]    2. Description of the Related Art 
         [0004]    Automatic analyzers for analyzing biologically-derived samples can be classified into analyzers for analyzing a sample by directly dispensing the sample into a reaction vessel from a sample vessel that has been charged into the analyzer for analysis; and analyzers for analyzing a sample by pipetting a sample from a charged sample vessel into another sample vessel in the analyzer and then by dispensing the sample into a reaction vessel from the latter sample vessel. The analyzer which directly dispenses a sample into a reaction vessel from a charged sample vessel has the advantage that its structure is simpler. In contrast, the analyzer which analyzes a sample after dispensing the sample from the charged sample vessel into another sample vessel has a more complex structure. However, it has the advantage that it is possible to reduce the amount of a sample required for analysis to a low level by diluting the sample before the sample is used for the analysis. Another advantage is that, if the dispensed sample is used, it is possible to immediately perform reanalysis when an abnormal state is detected from the result of the analysis. 
         [0005]    The latter type of automatic analyzer is disclosed in, for example, JP-A-8-194004. 
       SUMMARY OF THE INVENTION 
       [0006]    In the case of automatic analyzers that use a pipetted sample to perform analysis, each automatic analyzer includes therein a sample vessel that holds a pipetted sample and that is different from the original sample vessel in which the sample was contained. In the case of automatic analyzers that successively handle a large number of samples, a sample vessel for holding a pipetted sample is cleaned so that the sample vessel can be repeatedly used. However, while the sample vessel is repeatedly used, it is gradually contaminated, which decreases the precision of analysis. Therefore, it is necessary to periodically change sample vessels. 
         [0007]    The automatic analyzers calculate and output the concentrations of particular substances (analysis items) included in a sample from a signal value such as the absorbance, which is obtained by the automatic analyzer as a result of the sample analysis. For the purpose of the concentration calculation, the automatic analyzer is required to have a calibration curve of each analysis item. Therefore, a calibrator having a particular concentration is measured so as to calculate the calibration curve from the absorbance, which is the measurement result, and from the concentration of the calibrator. In order to achieve the analysis with high precision, it is necessary to correctly measure the calibrator to calculate the calibration curve. However, if measurements are made with a calibrator pipetted into the sample vessel that is repeatedly cleaned and used, the precision in measurement of the calibrator decreases, resulting in a possibility of not obtaining a correct calibration curve. Accordingly, if concentrations are calculated by incorrect calibration curves, there is a possibility that all measurements will become incorrect. 
         [0008]    A problem to be solved by the present invention is to achieve the analysis with high precision by preventing the contamination of a sample vessel from influencing the precision of analysis, with the use of an automatic analyzer including the sample vessel that is repeatedly cleaned and used, the automatic analyzer using a sample pipetted into the sample vessel to perform analysis. 
         [0009]    In order to solve the above-described problem, according to one aspect of the present invention, there is provided an automatic analyzer that is configured as follows: 
         [0010]    An automatic analyzer including a sample table on which a plurality of vessels are placed each of which temporarily holds a sample and is repeatedly cleaned and used, the automatic analyzer including a control mechanism for controlling a vessel for holding a sample whose concentration is known so that the vessel in question is used separately from a vessel for holding a general sample. 
         [0011]    The above-described automatic analyzer may further include specification means for specifying a vessel for holding a sample whose concentration is known. 
         [0012]    In addition, the above-described automatic analyzer may further include message issuing means for, on the basis of the measurement result of the sample whose concentration is known, issuing a message for promoting the replacement of the sample vessel used for the measurement. 
         [0013]    The above-described sample table does not mean a sample table on which a plurality of samples each being held in a test tube or the like are placed, but means a sample table for temporarily holding a sample to be subjected to dilution or pretreatment. The sample table may have any shape so long as the sample table can temporarily hold a sample. However, it is desirable that the sample table have the same shape as that of a reaction vessel so that the cleaning performed for the purpose of repeated use becomes easier. The sample whose concentration is known refers to a calibrator for calibration, a control sample, or the like. However, irrespective of the names, any sample can be adopted so long as it is a sample whose concentration is known. “Used separately” is synonymous with performing control in such a manner that a general sample is not used. For example, if there are 50 sample vessels in total, the use of the sample vessels is predetermined as follows: sample vessels numbered 1 through 40 are used to hold general samples; and sample vessels numbered 41 through 50 are used to hold only samples whose concentrations are known. By controlling a sample pipettor in such a manner, the above-described control can be achieved. Besides the control method that uses the sample vessel numbers, it is also possible to adopt a control method comprising the steps of: providing each sample vessel with identification information by use of a bar code, a magnetic recording medium, an IC tag, or the like; and providing a dispensing probe with means for reading out the identification information. 
         [0014]    The automatic analyzer according to the present invention can achieve the analysis with high precision by preventing the contamination of a sample vessel caused by other biologically-derived samples from influencing the result of calibration and by thus acquiring correct results of calibration. 
         [0015]    In addition, it is also possible to prevent the contamination of a sample vessel from influencing the analysis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a diagram schematically illustrating the overall configuration of an automatic analyzer according to a first embodiment of the present invention; 
           [0017]      FIG. 2  is a diagram illustrating an example of a setting screen used to set test sample vessel numbers for standard solution use only; 
           [0018]      FIG. 3  is a diagram schematically illustrating the overall configuration of an automatic analyzer according to a second embodiment of the present invention; and 
           [0019]      FIG. 4  is a diagram schematically illustrating the configuration of a sample vessel and a sample vessel holder. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    A first embodiment of the present invention will be described as below. 
       First Embodiment 
       [0021]      FIG. 1  is a diagram illustrating the overall configuration of an automatic analyzer according to the first embodiment. The automatic analyzer according to the present invention includes: a sample compartment  1  in which a sample vessel containing a biologically-derived sample is placed; a pipetted-sample compartment  2  in which a test sample vessel to contain a sample pipetted from the sample vessel is placed (it is also referred to as a “sample table”  2 ); a first reagent compartment  3  and a second reagent compartment  4  in both of which a plurality of reagent vessels each containing a reagent is placed; and a reaction compartment  5  in which a sample and reagents are put into a reaction cell to cause reaction thereof, the sample being dispensed from a test sample vessel  21  of the pipetted-sample compartment  2 , the reagents being dispensed from reagent vessels of the first and second reagent compartments. 
         [0022]    For example, 100 sample vessels  11  per circle, which are aligned in two rows, are placed along the circumference of the sample compartment  1 . The sample vessels  11  are fed step by step at specified speed. A specified amount of the sample placed in the sample vessel  11  is absorbed by a dispensing pipette  12  and is then discharged into the test sample vessel  21  at a specified position of the pipetted-sample compartment  2 . The pipetted sample is absorbed from the test sample vessel  21  by a sample pipette  22  and is then put into the reaction cell  51  of the reaction compartment  5 . Not only the dispensing pipette  12  and the sample pipette  22 , but also a sample vessel cleaning unit  24 , are located around the pipetted-sample compartment  2  so that the test sample vessel  21  is cleaned. After the dispensing of the sample, the first reagent and the second reagent, which have been sampled from the reagent vessels  31  and  41  by the reagent pipettes  32  and  42 , respectively, are each dispensed into the reaction cell  51  at a specified position so as to cause reaction thereof for a specified period of time. After the lapse of the specified period of time, a detector  52  measures the absorbance or the like to detect the reaction. Then, the reaction cell  51  for which detection has been completed is cleaned by a reaction vessel (cell) cleaning unit  53 . 
         [0023]    The pipetted-sample compartment  2  has a structure that is capable of holding, for example, 100 test sample vessels per circle. Serial numbers from 1 to 100 are assigned to the test sample vessels  21 . In the case of the automatic analyzer according to claim  1  of the present invention, for example, 10 test sample vessels numbered 91 through 100 are used to pipet standard solution for calibration measurement into, whereas 90 test sample vessels numbered 1 through 90 are used to pipet general samples into. 
         [0024]    In the first embodiment, when the general samples are analyzed, the pipetted-sample compartment  2  is transferred to a sample discharge position of the dispensing pipette  12  step by step. To be more specific, the sample vessels are used in number order, i.e., 1, 2, 3, . . . . When analysis of a calibrator is requested, subsequent to a sample vessel (for example, the number 10) containing a dispensed general sample, the pipetted-sample compartment  2  transfers a sample vessel used for the calibrator (for example, the number 91) to a sample discharge position to pipet the calibrator. The dispensing pipette  12  then pipettes the calibrator into the sample vessel  91 . When the general samples are analyzed next, a sample vessel used for the general samples (for example, the number 11) is transferred to a sample discharge position. 
         [0025]    When a biologically-derived sample is pipetted into the test sample vessel  21  in the pipetted-sample compartment  2 , the sample pipetted from the sample vessel  11  may also be mixed with a diluted solution in the test sample vessel  21  to make a diluted sample. 
         [0026]    In the case of an automatic analyzer according to claim  2 , an operator can arbitrarily specify a sample vessel used for the standard solution from the sample vessels numbered 1 through 100 on a operation screen.  FIG. 2  is a diagram illustrating an example of an operation screen on which a sample vessel used for the calibrator is specified. Standard solution to be specified is selected from a standard solution list  61  on a standard solution vessel setting screen; a vessel number to be specified is selected from a vessel number pull down list  62 , which is displayed on the right side of the standard solution list  61 . After the selection, when an “Update” button  63  is pressed, settings of the standard solution are stored. Then, the next standard solution can be set on the same setting screen. After all of required standard solutions are set, if a “Close” button  64  is pressed, the standard solution vessel setting screen is closed, thus completing the settings. 
         [0027]    In addition, in the case of an automatic analyzer according to claim  3 , a sample vessel which is common to the general samples is used for pipetting a control sample to be measured for the purpose of keeping track of the state of the automatic analyzer. If the measurement result of the control sample deviates from a reference value, an alarm is raised to prompt the operator to replace the sample vessel. 
       Second Embodiment 
       [0028]    A second embodiment of the present invention will be described below. 
         [0029]      FIG. 3  is a diagram illustrating the overall configuration of an automatic analyzer according to the second embodiment. The automatic analyzer according to the present invention includes a sample compartment  101  in which a sample vessel  111  containing a biologically-derived sample is placed; a pipetted-sample transfer line  102  in which a test sample vessel  121  to contain a sample pipetted from the sample vessel  111  is placed; a first reagent compartment  104  and a second reagent compartment  105  in both of which a plurality of reagent vessels each containing a reagent is placed; and a reaction compartment  106  in which a sample and reagents are put into a reaction cell to cause reaction thereof, the sample being dispensed from a sample vessel in the pipetted-sample transfer line  102 , the reagents being dispensed from reagent vessels of the first and second reagent compartments. In addition, an analysis unit  181 , which includes the first reagent compartment  104 , the second reagent compartment  105 , and the reaction compartment  106 , may be located plurally along the pipetted-sample transfer line  102 . A sample pipette  132  is located at a position adjacent to the pipetted-sample transfer line  102  of the analysis unit  181 . The sample pipette  132  dispenses a sample from the test sample vessel  121  in the pipetted-sample transfer line  102  into the reaction cell  161 . After the dispensing of the sample, the first reagent and the second reagent, which have been sampled from the reagent vessels  141  and  151  by the reagent pipettes  142  and  152 , respectively, are each dispensed into the reaction cell  161  at a specified position, so as to cause reaction thereof for a specified period of time. After the lapse of the specified period of time, a detector  162  measures the absorbance or the like to detect the reaction. Then, the reaction cell  161  for which detection has been completed is cleaned by a cleaning unit  163 . 
         [0030]    The pipetted-sample transfer line  102  further includes a main transfer line  122 , a result-waiting buffer line  123 , a dispensing-waiting line  124 , a dispensing-waiting line for standard solution  125 , and a dispensing line  126 . The test sample vessel  121  is transferred through each of the lines with the test sample vessel  121  held by a vessel holder  127 . The vessel holder  127  holds, for example, three test sample vessels  121 . The vessel holder  127  is provided with ID used to identify each test sample vessel. According to the ID information, each test sample vessel is transferred to a specified position at which sample pipetting, dispensing by the analysis unit  181 , or the like, is performed. 
         [0031]    The specified amount of a sample placed in the sample vessel  101  is absorbed by a dispensing pipette  112  and then discharged into the test sample vessel  121  at a specified position of the dispensing line  126 . The pipetted sample is transferred to the analysis unit  181  through the main transfer line  122 . After that, the pipetted sample is absorbed from the test sample vessel  121  by the sample pipette  132  and then put into the reaction cell  161  of the reaction compartment  106 . Not only the dispensing pipette  112  and the sample pipette  132  of the analysis unit  181  but also a sample vessel cleaning unit  133  are located around the pipetted-sample transfer line  102  so that the test sample vessel  121  is cleaned. After the dispensing of the sample, the first reagent and the second reagent, which have been sampled from the reagent vessels  141  and  151  by the reagent pipettes  142  and  152 , respectively, are each dispensed into the reaction cell  161  at a specified position so as to cause reaction thereof for a specified period of time. After the lapse of the specified period of time, the detector  162  measures the absorbance or the like to detect the reaction. Then, the reaction cell  161  for which detection has been completed is cleaned by a reaction cell cleaning unit  163 . 
         [0032]    The pipetted-sample transfer line  102  is capable of accommodating, for example, 100 vessel holders  127 . In other words, it is capable of holding 300 test sample vessels  121 . A unique ID is assigned to each of the vessel holders  127 . Each of the test sample vessels  121  is identified by ID assigned to each of the vessel holders  127  and a position in the vessel holder  127  in question. To be more specific, ID numbers 1 through 100 are assigned to the 100 vessel holders respectively; numbers 1 through 300 are assigned respectively to the 300 test sample vessels held by the vessel holders. For example, number 3 is assigned to the test sample vessel that is located at the position 3 in the vessel holder whose ID number is 1. 
         [0033]    In the case of the automatic analyzer according to claim  1  of the present invention, for example, 20 test sample vessels numbered 281 through 300 are used to pipet standard solution for calibration measurement into, whereas 280 test sample vessels numbered 1 through 280 are used to pipet general samples into. 
         [0034]    In the second embodiment, when the general samples are analyzed, the pipetted-sample transfer line  102  sequentially transfers the test sample vessels  121  to a sample discharge position of the dispensing pipette  112  located in the dispensing line  126 . Before a sample is discharged, a sample vessel ID reading unit  134  is located. Before a sample is pipetted into a test sample vessel  121 , its sample vessel ID is read out. The sample vessel ID is then recorded in a database in connection with the sample that has been discharged into the test sample vessel. Therefore, it is not always necessary to align the test sample vessels  121 , which are located in the pipetted-sample transfer line  102 , in the order of the ID numbers. 
         [0035]    Until the test sample vessel  121  is transferred to the dispensing line transfer  125 , it stands by in the dispensing-waiting line  124 . When pipetting of a sample is planned, the test sample vessel  121  is transferred from the dispensing-waiting line  124  to the dispensing line  126 . 
         [0036]    On the other hand, a test sample vessel specified for standard solution stands by in the dispensing-waiting line for standard solution  125 . The dispensing-waiting line for standard solution  125  is constituted of two lines, a waiting line and a carrying-out line. If pipetting of a standard solution is planned for calibration, a sample vessel to be used for the standard solution, which is located in the waiting line, is transferred from the carrying-out line to the dispensing line  126 . 
         [0037]    When a biologically-derived sample is pipetted into a test sample vessel  121 , the sample pipetted from the sample vessel  111  may also be mixed with a diluted solution in the test sample vessel  121  to make a diluted sample. 
         [0038]      FIG. 4  is a diagram illustrating the vessel holder  127 . The vessel holder  127  is configured to hold three test sample vessels  121  on the upper part of the vessel holder  127 . An IC tag  128  to which ID information is written is embedded on the side of the vessel holder  127 . 
         [0039]    As is the case with the first embodiment, the automatic analyzer according to claim  2  allows the operator to arbitrarily specify a test sample vessel used for the standard solution from the test sample vessels numbered 1 through 200 on an operation screen.  FIG. 2  is a diagram illustrating an example of the operation screen on which a test sample vessel used for the calibrator is specified. 
         [0040]    In addition, in the case of an automatic analyzer according to claim  3 , a sample vessel which is common to the general samples is used for pipetting a control sample to be measured for the purpose of keeping track of the state of the automatic analyzer. If the measurement result of the control sample deviates from a reference value, an alarm is raised to prompt the operator to replace the sample vessel.