Abstract:
A sample analyzer comprising: a measurement section; a transportation section; an identification data obtainer; and a system controller; is disclosed. The system controller is configured to acquire a result of determination regarding whether a sample needs a re-measurement for a sample based on a result of a measurement of the sample. When the system controller recognizes a presence of the washing fluid tube transported by the transportation section before a determination result regarding a necessity of re-measurement is obtained for an already aspirated sample, the system controller prohibits the supply of the washing fluid in the washing fluid tube to the measurement section.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2011-211147 filed on Sep. 27, 2011, the entire content of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to a sample analyzer for analyzing a clinical sample such as blood, urine or the like. The present invention also relates to a method for controlling such a sample analyzer. 
         [0003]    A sample processing apparatus for aspirating a sample through an aspirating tube from a sample tube containing samples such as blood, urine or the like, and processing the sample is known. 
         [0004]    If the sample processing apparatus is used for a long time, dirt may be accumulated in a fluid system such as aspiration tube, flow path, valve, reaction tube, and analyzing section. This may cause a lowering of the accuracy or cause operation failure. Thus the fluid system needs to be periodically washed for every predetermined time period or for every predetermined number of tests. 
         [0005]    Japanese Laid-Open Patent Application No. 2003-254980 discloses a specimen analyzer featured in an automatic washing. The apparatus is capable of aspirating a washing fluid contained in a fluid tube through an aspirating section, and washing an interior fluid circuit. With such configuration, when a rack holding the washing fluid tube is set in the specimen analyzer, the set rack is transported. The washing fluid is automatically aspirated from the washing fluid tube and the fluid circuit is washed when the apparatus recognizes that the transported tube on the rack is washing fluid tube. 
         [0006]    The washing of the fluid circuit using the washing fluid is carried out by filling the chamber used to prepare a measurement specimen, the detection unit, and the flow path for connecting the same with the washing fluid and leaving it untouched for a certain time, and thereby causing the dirt deposited inside the chamber and the flow path to be solved into the washing fluid. Therefore, a long time is required to perform a washing once. Accordingly, the sample cannot be measured for a long time once the washing is started. The washing using the washing fluid is thus preferably performed after all the measurements of the sample are finished. 
         [0007]    However, some samples require to be subject to re-measurement after the initial measurement. The determination on whether or not re-measurement is necessary is not made immediately after the completion of initial measurement, that is, there is a time lag between the time when the initial measurement is finished and the time when the determination is completed. 
         [0008]    Thus, there may be such a case where it is determined that a sample requires to be re-measured by a measurement apparatus, after that the measurement apparatus finished an aspiration of washing fluid from a washing fluid tube, In this case, the re-measurement of the sample needs to wait for a long time until the washing is finished. 
       SUMMARY OF THE INVENTION 
       [0009]    A first aspect of the present invention is a sample analyzer comprising: a measurement section configured to aspirate a sample in a sample tube and measure the aspirated sample; a transportation section configured to transport a plurality of tubes for supplying the tubes to the measurement section; an identification data obtainer configured to obtain identification data of the tube transported by the transportation section; and a system controller; wherein the system controller is configured to: acquire a result of determination regarding whether a sample needs a re-measurement, the determination being made based on a result of a measurement of the sample; when recognizing a presence of a washing fluid tube transported by the transportation section based on the identification data obtained by the identification data obtainer, control the transportation section to supply the washing fluid tube to the measuring section, and control the measurement section to aspirate the washing fluid from the washing fluid tube and then to use the aspirated washing fluid to wash at least one part of the measurement section; and when a presence of the washing fluid tube transported by the transportation section is recognized before the determination result is obtained for the already aspirated sample, prohibit the supply of the washing fluid in the washing fluid tube to the measurement section. 
         [0010]    A second aspect of the present invention is a sample analyzer comprising: a measurement section configured to aspirate a sample in a sample tube and measure the aspirated sample, a transportation section configured to transport a plurality of tubes to supply the tubes to the measurement section; and a system controller, wherein the system controller acquires a determination result regarding whether a sample needs a re-measurement, the determination being made based on a result of a measurement on the sample; the measurement section aspirates washing fluid in a washing fluid tube and then uses the aspirated washing fluid to wash at least one part of the measurement section if the washing fluid tube is supplied by the transportation section; and the sample analyzer retains the supply of the washing fluid in the washing fluid tube to the measurement section if the washing fluid tube follows the sample tube in an order of supplying the tubes to the measurement section until the system controller completes acquisition of the determination result of the sample in the preceding sample tube. 
         [0011]    A third aspect of the present invention is a method of controlling a sample analyzer comprising the steps of: (a) transporting a tube to a first position; (b) acquiring identification data from the tube at the first position, and determining whether the tube is a sample tube or a washing fluid tube; (c) transporting the tube to a second position for supplying the tube to a measurement section if the tube is determined as the sample tube in the determination of the step (b); (d) determining whether determination regarding a necessity of re-measurement is completed for a sample already aspirated by the measurement section, if the tube is determined as the washing fluid tube in the determination of the step (b); (e) transporting the washing fluid tube to the second position and controlling the measurement section to use the washing fluid in the washing fluid tube to executing a washing if the determination is completed in the determination of the step (d); and (f) prohibiting the execution of (e) if the determination is not completed in the determination of the step (e). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view showing an external appearance of a sample analyzer according to an embodiment; 
           [0013]      FIG. 2A  is a view showing a configuration of a sample tube according to the embodiment; and  FIG. 2B  is a view showing a configuration of a rack according to the embodiment; 
           [0014]      FIG. 3A  is a view showing a washing fluid tube according to the embodiment; and  FIG. 3B  is a view showing an arrangement rule of the washing fluid tube according to the embodiment; 
           [0015]      FIG. 4  is a plan view showing a configuration of a transportation unit and measurement units according to the embodiment viewed from an upper side; 
           [0016]      FIG. 5A  is a view showing a flowchart of a retrieving operation of the sample tube according to the embodiment; and  FIG. 5B  is a view showing a flowchart of a retrieving operation of the washing fluid tube according to the embodiment; 
           [0017]      FIG. 6  is a view showing an outline of a configuration of the transportation unit and the measurement unit according to the embodiment; 
           [0018]      FIG. 7  is a view showing an outline of a fluid circuit of the measurement unit according to the embodiment; 
           [0019]      FIG. 8  is a view showing an outline of a configuration of an information processing unit according to the embodiment; 
           [0020]      FIG. 9  is a view showing a flowchart of a transportation control of a rack according to the embodiment; 
           [0021]      FIG. 10  is a view showing a flowchart of a transportation control of a rack at time of washing and shutdown according to the embodiment; 
           [0022]      FIG. 11A  is a view showing a flowchart of transportation control process for normal sample according to the embodiment;  FIG. 11B  is a view showing a flowchart of retest process for normal sample according to the embodiment;  FIG. 11C  is a view showing a flowchart of flag setting process for normal sample according to the embodiment; 
           [0023]      FIG. 12A-12E  are views showing a flow of an operation of a rack according to the embodiment; 
           [0024]      FIG. 13A-13D  are views showing a flow of an operation of a rack according to the embodiment; 
           [0025]      FIG. 14  is a view showing a flowchart of a transportation control of a rack for performing a washing and a shutdown according to the modified embodiment 1; 
           [0026]      FIG. 15  is a view showing an external appearance of a sample analyzer according to the modified embodiment 2; 
           [0027]      FIG. 16A  is a view showing an arrangement rule of a washing fluid tube according to the modified embodiment 2;  FIG. 16B  is a view showing a flowchart of transportation of a rack according to the modified embodiment 2; and  FIG. 16C  is a view showing an arrangement rule of a washing fluid tube according to the modified embodiment 3; 
           [0028]      FIG. 17  is a view showing a flowchart of transportation of a rack according to the modified embodiment 3; 
           [0029]      FIG. 18  is a view showing a flowchart of transportation of a rack for performing a washing and a shutdown according to the modified embodiment 4; and 
           [0030]      FIG. 19A-19D  are views showing a flow of an operation of a rack according to the modified embodiment 4. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    The present embodiment applies the present invention to a sample analyzer for performing tests and analysis on blood. 
         [0032]    The sample analyzer according to the present embodiment will be hereinafter described with reference to the drawings. 
         [0033]      FIG. 1  is a perspective view showing an external appearance of a sample processing apparatus  1 . The sample processing apparatus  1  according to the present embodiment is mainly composed of a transportation unit  2 , two measurement units  31 ,  32  each including a blood cell counting section, and an information processing unit  4  (system controller). 
         [0034]    The transportation unit  2  is arranged on a front side of the measurement units  31 ,  32 . The transportation unit  2  includes a right table  21 , a left table  22 , and a rack transporting portion  23  connecting the right table  21  and the left table  22 . The right table  21  and the left table  22  can accommodate a plurality of racks L capable of holding ten tubes (sample tubes T or washing fluid tubes C). 
         [0035]    The transportation unit  2  can accommodate the rack L that has been placed by a user on the right table  21 . The transportation unit  2  transports the rack L accommodated in the right table  21 , and positions the rack L at a predetermined position of the rack transporting portion  23  so that the sample tube T and the washing fluid tube C on the rack L are supplied to the measurement units  31 ,  32 . Furthermore, the transportation unit  2  transports the rack L on the rack transporting portion  23  to the left table  22 . Thus, the rack L is transported along a flow from the right table  21  towards the left table  22 . Hereinafter, a direction of approaching the right table  21  is referred to as “upstream of transporting direction”, and a direction of approaching the left table  22  is referred to as “downstream of transporting direction” in the transportation path. 
         [0036]    In the present embodiment, the tube accommodated in the rack L is retrieved and processed by the measurement units  31 ,  32  in order from the downstream of the transporting direction at a retrieving position P 31   a  or P 32   a  (see  FIG. 4 ) on the rack transporting portion  23 . 
         [0037]      FIG. 2A  is a perspective view showing an external appearance of the sample tube T, and  FIG. 2B  is a perspective view showing an external appearance of the rack L holding ten sample tubes T. In  FIG. 2B , the direction (front-back, left-right and upstream-downstream of transporting direction of  FIG. 1 ) of when the rack L is mounted on the transportation unit  2  is also shown. 
         [0038]    With reference to  FIG. 2A , the sample tube T is a tube having a bottom and being made of glass or synthetic resin having translucency, and has an upper end opened. The blood sample of the whole blood collected from patient is accommodated inside, where the opening at the upper end is sealed by a lid CP made of rubber. In this embodiment, as the sample tube T having such configurations, a vacuumed blood collection tube is shown. A barcode label BL 1  is attached to the side surface of the sample tube T. A barcode including a sample ID is printed on the barcode label BL 1 . 
         [0039]    With reference to  FIG. 2B , ten holders are formed in the rack L at holding positions  1  to  10 . As shown in the  FIG. 2B , ten sample tubes T can be held lined in a perpendicular state (upright state). In order to explain easily, serial numbers are assigned for the respective holding positions from the downstream to the upstream of the transporting direction. 
         [0040]    A barcode label BL 2  is also attached to a side surface on the back side of the rack L. A barcode including a rack ID is printed on the barcode label BL 2 . 
         [0041]      FIG. 3A  is a perspective view showing an external appearance of the washing fluid tube C, and  FIG. 3B  is a view showing an arrangement of the washing fluid tube C when the rack L is seen from the upper surface. In  FIG. 3B , the upstream and downstream of the transporting direction and the numbers of the holding positions of the rack L shown in  FIG. 2B  are also shown. 
         [0042]    With reference to  FIG. 3A , the washing fluid tube C is a tube having a bottom and being made of colored glass or synthetic resin, and has an upper end opened. The color of the washing fluid tube C is different from the color of the sample tube T, so as to be easily distinguished visibly. The washing fluid contained inside the washing fluid tube C is chlorinated washing solution for washing the fluid circuit of the measurement units  31 ,  32 . The opening at the upper end is sealed by a film FM to prevent lowering in chloride concentration of the washing fluid. 
         [0043]    A barcode label BL 3  is attached to the side surface of the washing fluid tube C. A barcode including a washing fluid ID is printed on the barcode label BL 3 . The washing fluid ID is identifiable from the sample ID. The washing fluid tube C has similar shape and size as the sample tube T, and may be held in a perpendicular state (upright state) in the rack L, similar to the sample tube T. 
         [0044]    With reference to  FIG. 3B , the washing fluid tube C is installed in the rack L according to a predetermined arrangement rule. The holding positions are installed with the washing fluid tube C in an order from the holding positions nearest to the downstream of the transporting direction so as to rapidly perform the washing operation. The holding position where the washing fluid tube C is installed defines one of the measurement units that uses the washing fluid tube C. 
         [0045]    When washing is carried out on both the measurement unit  31  and the measurement unit  32 , two washing fluid tubes C are installed at the holding position  1  and the holding position  2 , as shown at the upper level of  FIG. 3B . Normally, the other holding positions  3  to  10  are not installed with the sample tube T or the washing fluid tube C. In this case, the washing fluid tube C at the holding position  1  is allocated to the measurement unit  31 , and the washing fluid tube C at the holding position  2  is allocated to the measurement unit  32 . 
         [0046]    The washing fluid tube C is installed only at the holding position  2 , as shown in the middle level of  FIG. 3B , when washing is carried out on the measurement unit  32  only. Similarly the washing fluid tube C is installed only at the holding position  1 , as shown in the lower level of  FIG. 3B , when washing is carried out on the measurement unit  31  only. In such cases, the washing fluid tube C is allocated to either one of the measurement units  31 ,  32 . 
         [0047]    Therefore, only the washing fluid tube C is normally installed in either one of or both of the holding position  1  and the holding position  2  of the rack L when washing the measurement units  31 ,  32 . 
         [0048]    Returning back to  FIG. 1 , the measurement unit  31  performs processing on the sample tube T on the rack transporting portion  23  on the front side of the relevant unit when measuring the sample. In other words, the measurement unit  31  picks up the sample tube T from the rack L with the hand portion  31   a  (see  FIG. 4 ) and transports the sample tube T into the measurement unit  31  at the retrieving position P 31   a  (see  FIG. 4 ) of the rack transporting portion  23 , so that the sample contained in the sample tube T is aspirated in the measurement unit  31 . After aspiration is completed, the measurement unit  31  returns the sample tube T again to original position of the holding positions of the rack L. The measurement unit  32  also aspirates the sample in a manner similar to the measurement unit  31 . 
         [0049]    In case where a washing is carried out on the measurement unit, the measurement unit  31  performs processing on the washing fluid tube C on the rack transporting portion  23  on the front side of the unit. Similar to measuring the sample tube T, the measurement unit  31  picks up the washing fluid C from the rack L by the hand portion  31   a  (see  FIG. 4 ) and transports the washing fluid tube C into the measurement unit  31  at the retrieving position P 31   a  (see  FIG. 4 ) of the rack transporting portion  23 . The measurement unit  31  then aspirates the washing fluid contained in the washing fluid tube C and flows it to the flow path and the detector used in the measurement of the sample in the measurement unit  31 . The washing fluid is also retained therein for a predetermined time to remove dirt. 
         [0050]    Preferably the washing is carried out once a day. For the purpose, washing fluid is retained for a long time in the fluid path, the detector and the like. After aspiration of washing solution is completed, the measurement unit  31  returns the washing fluid tube C again to the original position of the rack L. The measurement unit  32  also performs washing in a manner similar to the measurement unit  31 . The power of the washed measurement units  31 ,  32  is automatically shut down. 
         [0051]    The information processing unit  4  includes an input section  41  and a display section  42 . The information processing unit  4  is communicably connected to the transportation unit  2 , the measurement units  31 ,  32 , and a host computer  5  (see  FIG. 8 ) through a communication network. 
         [0052]    The information processing unit  4  controls the operations of the transportation unit  2  and the measurement units  31 ,  32 . The information processing unit  4  makes an inquiry on the measurement order to the host computer  5  (see  FIG. 8 ) when the sample ID is read by the barcode unit B 2  (see  FIG. 4 ). The information processing unit  4  performs analysis based on the measurement result performed by the measurement units  31 ,  32 , and transmits the analysis result to the host computer  5  (see  FIG. 8 ). The information processing unit  4  acquires a result of a determination by the host computer  5  (see  FIG. 8 ) regarding whether a retest of the sample is necessary or not. 
         [0053]    In the present embodiment, the retest is assumed to be carried out only once. Furthermore, retest in the present specification includes all measurements carried out by again aspirating the sample that is already aspirated and measured. Therefore, not only limited to again measuring the measurement item same as in the initial measurement, measuring a measurement item different from that in the initial measurement is also encompassed in the term “retest”. 
         [0054]    The information processing unit  4  can display information such as a warning message on the display section  42 . 
         [0055]      FIG. 4  is a view schematically showing a configuration of the transportation unit  2  and the measurement units  31 ,  32  viewed from the upper side. 
         [0056]    Hereafter, the reading operation of the barcode information will be described with reference to  FIG. 4 . 
         [0057]    The rack L mounted on the right table  21  is transported to a feeding position P 1  at the right end (most upstream position in the transporting direction) of the rack transporting portion  23  when the side surface on the front side is pushed by a rack feeding mechanism  21   a . The rack L positioned at the feeding position P 1  of the rack transporting portion  23  is transported towards the left direction by the belt (not shown) of the rack transporting portion  23 . Two belts of the rack transporting portion  23  are arranged in parallel, where if two racks L are positioned in the rack transporting portion  23 , each rack L is independently transported in the left and right direction by each belt. 
         [0058]    The barcode unit B 2  including the barcode reader B 2   a  is provided near the middle of the rack transporting portion  23 . When the holder of the rack L is positioned at the reading position P 2  on the front side of the barcode reader B 2   a , whether or not a tube (sample tube T or washing fluid tube C) is held in the holder is determined by a holding determination mechanism (not shown) of the barcode unit B 2 . Such holding determination mechanism includes a mechanism capable of sandwiching the tube from two opposed sides. If the tube is sandwiched, determination is made that the tube is held in the holder positioned at the reading position P 2 . 
         [0059]    If the sample tube T is held by the holder, the sample ID is read from the barcode label BL 1  of the sample tube T by the barcode reader B 2   a  while rotating the sample tube T, and if the washing fluid tube C is held by the holder, the washing fluid ID is read from the barcode label BL 3  of the washing fluid tube C by the barcode reader B 2   a  while rotating the washing fluid tube C. When the barcode label BL 1  of the rack L is positioned in front of the barcode reader B 2   a , the rack ID is read from the barcode label BL 2  of the rack L by the barcode reader B 2   a.    
         [0060]    The barcode information of the rack L, and tube presence/absence information and the barcode information of all the holders at the holding positions  1  to  10  of the rack L are acquired in such manner. 
         [0061]    The supply operation of the sample tube T and the washing fluid tube C of the rack L to the measurement units  31 ,  32  will now be described. 
         [0062]    As described above, when the barcode information is read, the sample tubes T installed in the holder of the rack L are, in principle, supplied to in order of the measurement unit  31  and the measurement unit  32  in an order from the tube arranged at the holding position in the downstream (left direction) of the transporting direction. For instance, if the sample tubes T 1 , T 2 , and T 3  are installed at the holding positions  1 ,  2 , and  3  of the rack L, the sample tube T 1  is positioned at the retrieving position P 31   a . At the retrieving position P 31   a , the hand portion  31   a  is provided movably in the up and down direction (Z axis direction). The sample tube T 1  positioned at the retrieving position P 31   a  is gripped by the hand portion  31   a , picked up in the upward direction (positive direction in Z axis) from the rack L, and retrieved into the measurement unit  31 . 
         [0063]    After the sample tube T 1  is picked up by the measurement unit  31 , during the aspiration of the sample in the measurement unit  31 , the sample tube T 2  is positioned at a retrieving position P 32   a . The sample tube T 2  positioned at the retrieving position P 32   a  is gripped by the hand portion  32   a , picked up in the upward direction (positive direction in Z axis) from the rack L, and retrieved into the measurement unit  32 . 
         [0064]    Thereafter, after the aspiration of the sample of the sample tube T 1  is completed in the measurement unit  31 , the holding position  1  of the rack L where the sample tube T 1  has been arranged, is again positioned at the retrieving position P 32   a . The sample tube T 1  gripped by the hand portion  31   a  of the measurement unit  31  is returned to the holding position  1  of the rack L from the upward direction (position direction in Z axis). 
         [0065]    Subsequently the sample tube T 3  is positioned at the retrieving position P 31   a  and retrieved by the measurement unit  31 . 
         [0066]    Thus, the sample tubes T installed in the rack L are sequentially supplied to the measurement units  31 ,  32  in an alternate shift by positioning the odd-numbered holding position at the retrieving position P 31   a  and positioning the even-numbered holding position at the retrieving position P 32   a  by the rack transporting portion  23 . 
         [0067]    The retest of the sample becomes sometimes necessary after measurement and analysis. In such a case, the sample tube T that is already subjected to the initial measurement may be cut in an order of supplying tubes to the measurement units to be preferentially supplied to the measurement unit. In this case, the sample tube T containing the sample that needs a retest is supplied to either one of the measurement units in preference to the sample tube T that has not yet subjected to the initial measurement. 
         [0068]    The supply of the washing fluid tube C to the measurement units  31 ,  32  is subjected to the arrangement rule shown in  FIG. 3B . The washing fluid tube C at the holding position  1  is positioned at the retrieving position P 31   a  and retrieved by the measurement unit  31 . The washing fluid tube C at the holding position  2  is then positioned at the retrieving position P 32   a  and retrieved by the measurement unit  32 . If the washing fluid tube C is held only at the holding position  2 , the washing fluid tube C is positioned at the retrieving position P 32   a  and retrieved to the measurement unit  32  even if the tube is not supplied to the measurement unit  31 . 
         [0069]    Thus, the washing fluid tube C installed in the rack L is supplied to the measurement units  31  or  32  according to the arrangement rule shown in  FIG. 3B  by the rack transporting portion  23 . 
         [0070]    When the sample tube T is positioned at the retrieving position P 31   a  or P 32   a , the sample tube T is automatically retrieved into the measurement unit  31  or  32 , and the sample is aspirated. When the washing fluid tube C is positioned at the retrieving position P 31   a  or P 32   a , the washing fluid tube C is automatically retrieved into the measurement unit  31  or  32 , and the washing fluid tube is aspirated and washed is done. Such operation is carried out under the control of a CPU  401  (see  FIG. 8 ) that will be described later. 
         [0071]      FIG. 5A  is a flowchart showing a retrieving operation of the sample tube T by the measurement unit  31  or  32 . 
         [0072]    With reference to  FIG. 4  and  FIG. 5A , when the sample tube T is positioned at the retrieving position P 31   a  (P 32   a ), the sample tube T is gripped by the hand portion  31   a  ( 32   a ), and picked up in the upward direction (positive direction in Z axis) (S 31 ). The hand portion  31   a  ( 32   a ) then moves the sample tube T like a pendulum to stir the sample (S 32 ). Then, the tube setting portion  31   b  ( 32   b ) is moved to the position above the retrieving position P 31   a  (P 32   a ) (S 33 ). After finishing the stirring, the hand portion  31   a  ( 32   a ) is moved in the downward direction (negative direction in Z axis), and the sample tube T gripped by the hand portion  31   a  ( 32   a ) is set in the tube setting portion  31   b  ( 32   b ) (S 34 ). 
         [0073]    Thereafter, the tube setting portion  31   b  ( 32   b ) is transported to the barcode reading position P 31   b  (P 32   b ) (S 35 ), and the sample tube T is checked by the barcode unit B 31  (B 32 ) including the barcode reader B 31   a  (B 32   a ) (S 36 ). 
         [0074]    The tube setting portion  31   b  ( 32   b ) is then positioned at the aspirating position P 31   c  (P 32   c ) at immediately below the piercing pipette  31   d  ( 32   d ) (S 37 ). The piercing pipette  31   d  ( 32   d ) is then moved in the downward direction, and the sample is aspirated by the piercing pipette  31   d  ( 32   d ) from the sample tube T (S 38 ). 
         [0075]    After the aspiration of the sample by the piercing pipette  31   d  ( 32   d ) is finished, the tube setting portion  31   b  ( 32   b ) is moved to the front side and again positioned at the retrieving position P 31   a  (P 32   a ) (S 39 ). At the retrieving position P 31   a  (P 32   a ), the sample tube T is retrieved in the upward direction by the hand portion  31   a  ( 32   a ) from the tube setting portion  31   b  ( 32   b ) (S 40 ). The tube setting portion  31   b  ( 32   b ) is moved to the back side in this state. Thereafter, the hand portion  31   a  ( 32   a ) is moved in the downward direction (negative direction in Z axis), and the sample tube T is returned to the original holder of the rack L positioned in the rack transporting portion  23  (S 41 ). 
         [0076]      FIG. 5B  is a flowchart showing a retrieving operation of the washing fluid tube C by the measurement unit  31  or  32 . 
         [0077]    In  FIG. 5B , steps S 51  and S 52  to S 60  are the same as S 31  and S 33  to S 41  of  FIG. 5A  other than that a tube to be aspirated is the washing fluid tube C. Thus, the description of each step will be omitted herein. Emphasis should be made on the point that, in the retrieving operation of  FIG. 5B , the step corresponding to S 32  of  FIG. 5A  is skipped. This is because the washing fluid tube C does not need to be stirred. 
         [0078]    In a case where the samples are measured, the sample tube T may possibly be supplied to the measurement unit  31  or  32  again for the retest of the sample even after the aspirations of all the samples are completed and all the sample tubes T are returned to the holders of the rack L. Normally, the time until the acquisition of the necessity of retest is acquired is longer than the time for the measurement of the sample in the measurement unit  31 ,  32  due to the communication of the measurement result to the information processing unit  4  and the host computer  5 , the analyzing process of the measurement result, and the like (e.g., the measurement of the sample needs about 36 seconds, the time until acquisition of the necessity of retest is completed is about 75 seconds). Therefore, the rack L is waited on the rack transporting portion  23  until the acquisition of the necessity of retest of the sample of all the sample tubes T is completed. 
         [0079]    A transportation space P 5  longer than a length in the left and right direction of the rack L is provided in the left direction of the retrieving position P 31   a  of the rack transporting portion  23 . The rack L is positioned in the transportation space P 5  until the acquisition of the necessity of retest for each of the samples of all the sample tubes T is completed. Thereby a space allowing to move the following rack on the rack transportation path is obtained. 
         [0080]    After the process related to the retest is completed for all the sample tubes T, the rack L is positioned at the backward position of the left table  22 , and transported to the front side of the left table  22  by a rack feeding mechanism  22   a.    
         [0081]    If the washing fluid tube C is held in the rack L, the washing liquid is aspirated for all the washing liquid tubes C, and thereafter, the rack L is positioned at the backward position of the left table  22 , and transported to the front side of the left table  22  by the rack feeding mechanism  22   a.    
         [0082]    In such manner, the measuring process or the washing process is performed for all the racks L present at the right table  21 . 
         [0083]      FIG. 6  is a view showing an electrical connection relationship of the transportation unit  2  and the measurement unit  31 ,  32 . 
         [0084]    The transportation unit  2  includes a driving unit  201 , a sensor unit  202 , a barcode unit B 2 , and a communication unit  203 . 
         [0085]    The driving unit  201  includes a mechanism for transporting the rack L in the transportation unit  2 , and the sensor unit  202  includes a sensor for detecting the rack L at a predetermined position on a transportation path of the transportation unit  2 . The barcode unit B 2  includes a holding determination mechanism (not shown), and a barcode reader B 2   a.    
         [0086]    The communication unit  203  is communicably connected with the information processing unit  4 . Each section of the transportation unit  2  is controlled by the information processing unit  4  through the communication unit  203 . A signal output from each section of the transportation unit  2  is transmitted to the information processing unit  4  through the communication unit  203 . 
         [0087]    The measurement units  31 ,  32  respectively include an aspirating unit  311 ,  321 , a specimen preparing unit  312 ,  322 , a detection unit  313 ,  323 , a driving unit  314 ,  324 , a sensor unit  315 ,  325 , a barcode unit B 31 , B 32 , and a communication unit  316 ,  326 . The measurement units  31 ,  32  have exactly the same configuration, and thus only the measurement unit  31  will be described below. 
         [0088]      FIG. 7  is a view showing an outline of a fluid circuit of the measurement unit  31 . The measurement unit  31  is a blood cell counting apparatus configured to count blood cells contained in a whole blood sample. 
         [0089]    The aspirating unit  311  includes a piercing pipette  31   d  for aspirating a sample contained in a sample tube T and a washing fluid contained in a washing fluid tube C taken into the measurement unit  31 . Thereafter the piercing pipette is inserted to the tube, and a negative pressure generated by a syringe pump SP is applied to the piercing pipette  31   d . The specimen preparing unit  312  includes a reaction chamber MC 1  for preparing a specimen for measuring red blood cells and blood platelets, and a reaction chamber MC 2  for preparing a specimen for measuring white blood cells. The detection unit  313  includes an electrical resistance detector DC 1  for measuring red blood cells and blood platelets, and an optical detector DC 2  for optically measuring white blood cells. The measurement unit  31  includes a waste fluid chamber WC for accommodating waste fluid. 
         [0090]    When measuring the sample contained in the sample tube T, the aspirating unit  311  aspirates the sample through the piercing pipette  31   d  by applying negative pressure to the piercing pipette  31   d  with the syringe pump SP, and discharges the sample to each reaction chamber MC 1 , MC 2 . The specimen preparing unit  312  mixes sample and reagent in the reaction chamber MC 1  to prepare a specimen for measuring red blood cells and blood platelets. The specimen preparing unit  312  mixes sample and reagent in the reaction chamber MC 2  to prepare a specimen for measuring white blood cells. The specimen prepared in the reaction chamber MC 1  is supplied to the electrical resistance detector DC 1  through the flow path, and the specimen prepared in the reaction chamber MC 2  is supplied to the optical detector DC 2  through the flow path. The detection unit  313  detects optical signals (side fluorescent signal, forward scattered light signal, side scattered light signal, etc.) from white blood cells, nucleated red blood cells, and the like in the specimen as data of the sample with the optical detector DC 2 . The detection unit  313  also detects electrical signals from red blood cells and blood platelets in the specimen as data of the sample with the electrical resistance detector DC 1 . The specimen that passed the detection unit  313  is supplied to the waste fluid chamber WC through the flow path. 
         [0091]    When performing washing using the washing fluid contained in the washing fluid tube C, the washing fluid is sent along the path similar to the sample. That is, washing fluid is aspirated from the washing fluid tube C by the aspirating unit  311  and discharged to each reaction chamber of the specimen preparing unit  312 , so that the path from each reaction chamber to the waste fluid chamber WC is filled with washing fluid. It is left untouched in this state for a long time (about 30 minutes), and thereby residues of sample or reagent attached to the inner wall of the reaction chamber are removed. 
         [0092]    Returning back to  FIG. 6 , the driving unit  314  includes a mechanism for transporting the sample tube T and the washing fluid tube C in the measurement unit  31 . The sensor unit  315  includes a sensor for detecting a sample tube T or a washing fluid tube C at a predetermined position on the transportation path of the measurement unit  31 . As described above, the barcode unit B 31  includes a holding determination mechanism (not shown) and a barcode reader B 31   a.    
         [0093]    The communication unit  316  is communicably connected with the information processing unit  4 . Each section of the measurement unit  31  is controlled by the information processing unit  4  through the communication unit  316 . A signal output from each section of the measurement unit  31  is transmitted to the information processing unit  4  through the communication unit  316 . 
         [0094]      FIG. 8  is a view showing a configuration of the information processing unit  4 . 
         [0095]    The information processing unit  4  includes a personal computer and is configured by a main body  40 , an input section  41 , and a display section  42 . The main body  40  includes a CPU  401 , a ROM  402 , a RAM  403 , a hard disc  404 , a readout device  405 , an input/output interface  406 , an image output interface  407 , and a communication interface  408 . 
         [0096]    The CPU  401  can execute computer programs stored in the ROM  402  and the computer programs loaded in the RAM  403 . The RAM  403  is used to read out the computer programs recorded on the ROM  402  and the hard disc  404 . In executing the computer programs, the ROM  403  is used as a work area of the CPU  401 . 
         [0097]    The hard disc  404  is installed with various computer programs to be executed by the CPU  401  such as operating system and application programs, as well as data used in executing the computer program. In other words, the hard disc  404  is installed with a program for analyzing the data of the sample transmitted from the measurement units  31 ,  32  to generate measurement results of the number of red blood cells, the number of white blood cells, and the like, and making a display on the display section  42  based on the generated measurement results. 
         [0098]    The readout device  405  includes a CD drive or DVD drive, and is capable of reading out a computer program or data recorded in a recording medium. The input section  41  including a mouse and a keyboard connected to the input/output interface  406 , where the user uses the input section  41  to input instructions and data to the information processing unit  4 . The display section  42  including a display connected to the image output interface  407 , where a video signal corresponding to the image data is output to the display section  42 . 
         [0099]    The display section  42  displays the image based on the input video signal. Various types of program screens are displayed on the display section  42 . The data is transmitted and received with respect to the transportation unit  2  and the measurement units  31 ,  32  by the communication interface  408 . 
         [0100]      FIG. 9  is a flowchart of the control operation of the rack L by the CPU  401  of the information processing unit  4 . 
         [0101]    First, whether to perform a washing and a shutdown process or to perform a sample process is determined for the rack L according to the type of tube arranged in the holding positions  1  and  2  of the rack L. 
         [0102]    Specifically, when the rack L is set in the right table  21 , the CPU  401  operates the rack feeding mechanism  21   a  to transport the rack L to the feeding position P 1  of the rack transporting portion  23  (S 1 ). The CPU  401  operates the rack transporting portion  23  to transport the rack L so that the holding positions  1  and  2  of the rack L are positioned at the barcode reading position P 2  (S 2 ). For each of the holding positions  1  and  2 , presence or absence of the tube is determined. If at least one of the holding positions  1  and  2  is installed with a tube, the barcode information of the detected tube is read by the barcode unit B 2 . The CPU  401  then determines whether a washing fluid tube C is installed with at least one of the holding position  1  or  2  (S 3 ). 
         [0103]    If the washing fluid tube C is at the holding position  1  or  2  (S 3 : YES), the CPU  401  executes the washing and shutdown process (S 11 ). The details of the washing and shutdown process (S 11 ) will be described later with reference to  FIG. 10 . The process on the rack L is then completed. 
         [0104]    If the washing fluid tube C is not at either holding positions  1 ,  2  (S 3 : NO), the CPU  401  executes the normal sample process (S 21 ). The details of the normal sample process (S 21 ) will be described later with reference to  FIG. 11 . 
         [0105]    When some steps in all steps of the normal sample process S 21  is completed for the rack L, next rack L is allowed to be fed into the transportation path. The CPU  401  determines whether a rack L to be transported is present at the right table  21  (S 22 ). Specifically, the timing the following rack L can be fed into the transportation path is the time when a necessity of retest is acquired for a predetermined number of sample tubes T of the rack L and it is determined that the preceding rack L does not need to be returned to the position of the feeding position P 1  of the rack transporting portion  23 . In the present embodiment, if it is determined that samples held at the holding positions  1  to  6  are not required to be retested, the preceding rack L may no longer be returned to the feeding position P 1 . Therefore, the following rack L can be positioned at the feeding position P 1 . 
         [0106]    In such state, if a following rack L exists in the right table  21  (S 22 : YES), the process is returned to S 1  so that the following rack L is transported to the feeding position P 1 , the processes described above will be repeated, and the sample process or the washing process will be performed. 
         [0107]    If the following rack L does not exist in the right table (S 22 : NO), the process is completed for all the racks L. 
         [0108]    Hereinafter, a processing flow will be described assuming a state where the preceding rack L 1  is subjected to the normal sample process S 21 , and the following rack L 2  following the preceding rack L 1  is subjected to the washing and shutdown process S 11 . 
         [0109]      FIG. 10  is a flowchart of control operation of the following rack L 2  by the CPU  401  in the washing and shutdown process of S 11  of  FIG. 9 . 
         [0110]    If a washing fluid tube C is arranged at the holding position  1  or the holding position  2  of the following rack L 2  by the process shown in  FIG. 9 , the CPU  401  makes a washing reservation of the measurement unit corresponding to the arrangement of the washing fluid tube C (S 101 ). For instance, if the washing fluid tube C is set in both the holding position  1  and the holding position  2 , the reservation for washing is made on both of the measurement units  31  and the measurement unit  32 . If the washing fluid tube C is set only in the holding position  1 , the reservation for washing is made only on the measurement unit  31 . 
         [0111]    The CPU  401  then determines whether or not the preceding rack L 1  preceding the following rack L 2  exists on the rack transporting portion  23  (S 102 ). If the preceding rack L 1  does not exist on the rack transporting portion  23  (S 102 : NO), the CPU  401  proceeds the process to S 105 , whereas if the preceding rack L 1  exists on the rack transporting portion  23  (S 102 : YES), the CPU  401  determines whether or not a retest necessity acquisition complete flag of the preceding rack L 1 , to be described later, is set (S 103 ). If the acquisition of retest necessity is completed from the host computer  5  for all the samples of the preceding rack L 1 , the retest necessity acquisition complete flag is set, and if the retest necessity acquisition is not completed, the retest necessity acquisition complete flag is not set. 
         [0112]    If the retest necessity acquisition complete flag of the preceding rack L 1  is not set (S 103 : NO), the CPU  401  waits for the subsequent processes until the retest necessity acquisition complete flag of the preceding rack L 1  is set. If the retest necessity acquisition complete flag of the preceding rack L 1  is set (S 103 : YES), the CPU  401  further determines whether retest is unnecessary for any of the samples of the preceding rack L 1  (S 104 ). 
         [0113]    If retest is unnecessary for any of the samples of the preceding rack L 1  (S 104 : YES), the CPU  401  operates the transporting portion  23  to transport the washing fluid tube C to the retrieving positions P 31   a  or P 32   a  corresponding to the measurement units  31  or  32  on which washing reservation has been made (S 105 ). In the measurement units  31  or  32  on which the washing reservation is made, the washing process using the transported washing fluid tube C is carried out (S 106 ). The washing includes the task of retaining the washing fluid in the fluid circuit of the measurement unit over a long time (about 30 minutes). As will be described later, the time from when the sample is aspirated until the measurement and the determination on the necessity of retest are completed takes 75 seconds, and hence the time required for washing is longer than the time required from aspiration to the determination on the necessity of retest. 
         [0114]    If the retest is not unnecessary (S 104 : NO) for all the samples of the previous rack L 1 , in other words, when one or more of samples of the previous rack L 1  need to be subjected to the retest, the CPU  401  determines whether or not the washing reservation is made on the measurement unit  32  which is provided on the upstream side in the transporting direction (S 109 ). If the washing reservation is not made on the measurement unit  32  (S 109 : NO), the CPU  401  proceeds the process to S 113 , and if the washing reservation is made on the measurement unit  32  (S 109 : YES), the CPU  401  determines whether the measurement unit  32  on the upstream side is vacant (S 110 ). The “vacant” means a state where any sample is not processing by the measurement unit  32 . If the measurement unit  32  is performing the retest and is not vacant (S 110 : NO), the CPU  401  waits for the following process until the measurement unit  32  becomes a vacant state. If the measurement unit  32  is vacant (S 110 : YES), the CPU  401  operates the rack transporting portion  23  to transport the washing fluid tube C to the retrieving position P 32   a  corresponding to the measurement unit  32  (S 111 ). In the measurement unit  32 , the washing process using the washing fluid tube C is carried out (S 112 ). In this case, the retest of the sample is carried out in the measurement unit  31  on the downstream side for the sample in which the retest has not started yet. 
         [0115]    The CPU  401  determines whether or not the washing reservation has been made on the measurement unit  31  on the downstream side in the transporting direction (S 113 ). If the washing reservation has not been made on the measurement unit  31  (S 113 : NO), the CPU  401  proceeds the process to S 107 , and if the washing reservation has been made on the measurement unit  31  (S 113 : YES), the CPU  401  determines whether an aspiration for the retest is completed for all the samples of the preceding rack L 1  (S 114 ). 
         [0116]    If an aspiration for the retest is not completed (S 114 : NO) for all the samples of the preceding rack L 1 , the CPU  401  waits for the following process until the aspiration for the retest is completed for all the samples of the preceding rack L 1 . If the aspiration is completed (S 114 : YES), the sample of the preceding rack L 1  will not be supplied to the measurement unit  31 , and hence the CPU  401  operates the rack transporting portion  23  to transport the washing fluid tube C to the retrieving position P 31   a  corresponding to the measurement unit  31  (S 115 ). In the measurement unit  31 , the washing process using the washing fluid tube C is carried out (S 116 ). 
         [0117]    After the washing processes of the measurement units  31  and  32  are completed, the CPU  401  operates the rack transporting portion  23  to transport the following rack L 2  to the collecting position P 4  (S 107 ). The following rack L 2  transported to the collecting position P 4  is discharged to the left table  22  by a rack pushing mechanism  23   a . Thereafter, when washing for both measurement units  31 ,  32  is completed, the CPU  401  shuts down the measurement units  31 ,  32  and the information processing unit  4  (S 108 ). If washing is completed for only one of the measurement units  31  or  32 , the shutdown process of the measurement units  31  and  32  and the information processing unit  4  is not executed, and the shutdown is executed only after washing of both measurement units  31  and  32  is completed. 
         [0118]    Thus, if there is a sample in which the retest is not completed at the stage where the acquisition of the retest necessity is completed for all the samples of the preceding rack L 1 , the CPU  401  performs the washing process on one of the measurement units  31  and  32  while leaving the remaining one of the measurement unit  31  and  32 . The remaining measurement unit will be washed after aspiration for the retest is completed for all the samples of the preceding rack L 1 . The CPU  401  thereby completes the process on the following rack L 2 . 
         [0119]      FIG. 11A  is a flowchart showing an operation of the preceding rack L 1  by the CPU  401  at the time of the normal sample process of S 21  of  FIG. 9 . 
         [0120]    If the washing fluid tube C is not contained in either the holding position  1  nor the holding position  2  of the preceding rack L 1  by the process shown in  FIG. 9 , the CPU  401  operates the rack transporting portion  23  to transport the preceding rack L 1  so that the following holding positions  3  to  10  are sequentially positioned at the barcode reading position P 2  (S 201 ). In this case, the presence or absence of the tube at each holding position is determined by the barcode unit B 2 , and the barcode information of the tube installed at each holding position is read (S 202 ). 
         [0121]    The CPU  401  then operates the rack transporting portion  23  to transport the sample tubes T to the retrieving position P 31   a  or the retrieving position P 32   a  (S 203 ). As described above, the sample tubes T are distributed to the measurement units  31 ,  32  in an order from the downstream in the transporting direction. If both measurement units  31  and  32  are in measurement, the CPU  401  waits until the measurement in either one of the measurement units is completed. If a holder is not installed with a sample tube or the holder is installed with a washing fluid tube C, the holder will be skipped. The CPU  401  then operates the measurement units  31 ,  32  to aspirate a sample in the transported sample tube T, to perform a measurement, and to generate a measurement result (S 204 ). The measurement result is transmitted via the information processing unit  4  to the host computer  5  (S 205 ). 
         [0122]    The host computer  5  determines the necessity of retest based on the received measurement result, and transmits the determination result on the necessity of retest to the information processing unit  4 . The necessity of retest is determined by whether or not the received measurement result is within a numerical value range indicating a normal measurement result. More specifically, if the measurement result of a certain sample is within the numerical value range, the host computer  5  assumes that such sample is normal, determines that retest for such sample is unnecessary, and transmits the determination result that the retest is unnecessary. If the measurement result of a certain sample is not within the numerical value range, the host computer  5  assumes that the sample is abnormal or the measurement operation is abnormal, and thus determines that retest is necessary for such sample. If determined that the retest is necessary, the host computer  5  further automatically generates the measurement order including the measurement item to be measured in the retest, and transmits the measurement order with the determination result indicating that the retest is necessary. 
         [0123]      FIG. 11B  is a flowchart showing a flow of operation of the retest process at the time of the normal sample process. The relevant process is started when the normal sample process is started. 
         [0124]    With reference to  FIG. 11B , the CPU  401  first determines whether the determination result of the retest necessity is acquired from the host computer  5  for a sample (S 211 ). If the determination result of the retest necessity is not acquired (S 211 : NO), the CPU  401  waits for the following process until the determination result is acquired. If the determination result of the retest necessity is acquired (S 211 : YES), the CPU  401  determines whether or not the retest is necessary for the sample based on the acquired determination result (S 212 ). 
         [0125]    The CPU  401  proceeds the process to S 215  if the retest of the sample is not necessary (S 212 : NO), and if the retest of the sample is necessary (S 212 : YES), the CPU  401  operates the rack transporting portion  23  to transport the sample tube T that accommodates the sample to be retested to the retrieving position  31   a  or the retrieving position  32   a  (S 213 ). And the CPU  401  operates the measurement unit to perform the retest process on the sample according to the measurement order received with the determination result (S 214 ), similar to the measurement process. The retest process cuts into the normal sample process, and is carried out prior to the normal sample process. 
         [0126]    The CPU  401  then determines whether or not the determination result of the retest necessity is acquired for all the samples of the preceding rack L 1  (S 215 ). If the determination result of the retest necessity is not acquired for all the samples of the preceding rack L 1  (S 215 : NO), the CPU  401  repeats the steps S 211  to S 215  until the determination results of all the samples are acquired. When the determination result of the retest necessity is acquired for all the samples of the preceding rack L 1  (S 215 : YES), the CPU  401  completes the retest process on the preceding rack L 1 . 
         [0127]    Returning back to  FIG. 11A , after transmitting the measurement result to the host computer  5 , the CPU  401  determines whether or not measurements for all the samples of the preceding rack L 1  are completed (S 206 ). If measurements for all the samples of the preceding rack L 1  are not completed (S 206 : NO), the CPU  401  repeats the processes S 203  to S 206 . As described above, if a necessity of retest occurs during the sequential measurements of the samples, the retest process is preferentially carried out. 
         [0128]    After measurements of all the samples of the preceding rack L 1  are completed (S 206 : YES), the CPU  401  waits until the aspiration for the retest is completed for all the samples of the preceding rack L 1 . When the aspiration for the retest is completed (S 207 : YES) for all the samples of the preceding rack L 1 , the CPU  401  operates the rack transporting portion  23  to transport the preceding rack L 1  to the collecting position P 4  (S 208 ). The preceding rack L 1  transported to the collecting position P 4  is discharged to the left table  22  by the rack pushing mechanism  23   a . The washing fluid tube C of the following rack L 2  is thereby supplied to the measurement unit  31  on the downstream side. The CPU  401  therefore completes the normal sample process on the preceding rack L 1 . 
         [0129]      FIG. 11C  is a flowchart showing a flow of the setting process of the retest necessity acquisition complete flag. This flow is started when the normal sample process is started. 
         [0130]    With reference to  FIG. 11C , the CPU  401  first waits for the determination result about the necessity of retest sent from the host computer  5  (S 221 ). When the determination result is acquired (S 221 : YES), the CPU  401  determines whether or not the determination result is acquired for all the samples of the preceding rack L 1  (S 222 ). When the determination result is acquired for all the samples of the preceding rack L 1  (S 222 : YES), the CPU  401  sets the retest necessity acquisition complete flag (S 223 ). The setting process of the retest necessity acquisition complete flag is thereby completed. When the retest necessity acquisition complete flag is set, the determination of S 103  of  FIG. 10  becomes YES and the processes after S 104  are proceeded. 
         [0131]      FIG. 12  is a view showing an operation state of the rack transporting portion  23  of the preceding rack L 1  and the following rack L 2  when the determination of the retest necessity from the host computer  5  is “unnecessary” for all the samples of the preceding rack L 1 . The sample tubes T are held in the holding positions  1  to  10  in the preceding rack L 1 , and only the washing fluid tube C is held in the holding positions  1  and  2  in the following rack L 2 . 
         [0132]      FIG. 12A  is a view showing a state of when the following rack L 2  is positioned at the feeding position P 1 . Such state corresponds to a state in which the CPU  401  is processing the measurement process of S 203  to S 206  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing S 1  of  FIG. 9  for the following rack L 2 . 
         [0133]    With respect to the sample tubes T installed in the holding positions  1  to  6  of the preceding rack L 1 , the retest necessity is already acquired, and determination is made that retest is unnecessary. The sample tubes T installed at the holding positions  7 ,  8  of the preceding rack L 1  are supplied to the measurement units  31 ,  32 . In this case, the sample tubes T installed at the holding positions  1  to  6  of the preceding rack L 1  are not supplied to the measurement units  31 ,  32 , and the preceding rack L 1  will not be returned to the feeding position P 1 . The following rack L 2  is thereby positioned at the feeding position P 1 . 
         [0134]      FIG. 12B  is a view showing a state of when the tube type of the holding positions  1 ,  2  of the following rack L 2  is identified. Such state corresponds to a state in which the CPU  401  processes the measurement process of S 203  to S 206  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1 , and processes S 3  of  FIG. 9  for the following rack L 2 . 
         [0135]    With respect to the sample tubes T installed in the holding positions  1  to  7  of the preceding rack L 1 , the retest necessity is already acquired, and determination is made that retest is unnecessary. The sample tubes T installed at the holding positions  9 ,  10  of the preceding rack L 1  are supplied to the measurement units  31 ,  32 . The following rack L 2  has the holding positions  1 ,  2  positioned at the barcode reading position P 2 , and the tubes installed in the holding positions  1 ,  2  are identified as the washing fluid tubes C. 
         [0136]      FIG. 12C  is a view showing a state when the measurement process of the sample tube T of all the holders of the preceding rack L 1  is completed. Such state corresponds to a state in which the CPU  401  is processing the completion waiting process of the aspiration for the retest of S 207  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing the retest necessity acquisition complete waiting of S 103  of  FIG. 10  for the following rack L 2 . 
         [0137]    In the preceding rack L 1 , when the measurement of the sample tube T of the holding position  10  is completed, the sample tube T is returned from the measurement unit  32  to the preceding rack L 1 . In this case, the preceding rack L 1  is determined that the retest necessity is already acquired and the retest is unnecessary for the sample tubes T at the holding positions  1  to  8 . The following rack L 2  is evacuated to the feeding position P 1  to wait thereat since the tubes installed at the holding positions  1 ,  2  are identified as the washing fluid tubes C but the acquisition of retest necessity of all the samples of the preceding rack L 1  is not completed. 
         [0138]      FIG. 12D  is a view showing a state of when the measurement process of the sample tube T of all the holders of the preceding rack L 1  is completed, the state being before the retest necessity is acquired. Such state corresponds to a state in which the CPU  401  is processing the completion waiting process of the aspiration for the retest of S 207  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing the retest necessity acquisition complete waiting of S 103  of  FIG. 10  for the following rack L 2 . 
         [0139]    The preceding rack L 1  waits in the transportation space P 5  of the rack transporting portion  23  so that the preceding rack L 1  does not interfere the processing of the following rack L 2  after the measurement process of the sample tube T of all the holders at the holding positions  1  to  10  is completed. In this case, samples in the sample tubes T at the holding positions  1  to  9  other than the holding position  10  are determined that the retest for each of them is unnecessary. In this case, the measurement units  31 ,  32  are vacant, but the following rack L 2  waits at the feeding position P 1  since the retest necessity acquisition of all the samples of the preceding rack L 1  is not completed. 
         [0140]      FIG. 12E  is a view showing a state of when the retest necessity is acquired for the sample tubes T of all the holders of the preceding rack L 1 . Such state corresponds to a state in which the retest process of  FIG. 11B  and the flag setting process of  FIG. 11C  are completed, and the CPU  401  is processing S 208  of  FIG. 11A  for the preceding rack L 1  and starting the washing processes of S 105  and S 106  of  FIG. 10  for the following rack L 2 . 
         [0141]    For each of the samples in the sample tubes T of all the holders at the holding positions  1  to  10  of the preceding rack L 1 , it has been determined that the retest is unnecessary. The preceding rack L 1  is then positioned at the collecting position P 4 , and pushed away to the left table  22 . The following rack L 2  supplies the washing fluid tube C to the measurement units  31 ,  32 . 
         [0142]      FIG. 13  is a view showing an example of an operation state of the rack transporting portion  23  of the preceding rack L 1  and the following rack L 2  when the determination of the retest necessity from the host computer  5  indicates “necessary” for the samples installed at the holding positions  9 ,  10  of the preceding rack L 1 . 
         [0143]      FIGS. 13A and 13B  are views showing a state of when the measurement process of the sample tube T of all the holders of the preceding rack L 1  is completed, the state being before the retest necessity is acquired. Such state corresponds to a state in which the CPU  401  is processing the completion waiting process of the aspiration for the retest of S 207  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing the retest necessity acquisition complete waiting of S 103  of  FIG. 10  for the following rack L 2 . 
         [0144]    With reference to  FIG. 13A , the preceding rack L 1  waits in the transportation space P 5  of the rack transporting portion  23  so that the preceding rack L 1  does not interfere the processing of the following rack L 2 . In this case, for the samples in the samples tubes T at the holding positions  1  to  9 , the retest necessity is already acquired. Further, it is determined that the retest is unnecessary for the sample tubes T at the holding positions  1  to  8 , and the retest is necessary for the sample tube T at the holding position  9 . The following rack L 2  is evacuated to the feeding position P 1  to wait thereat since the tubes installed at the holding positions  1 ,  2  are identified as the washing fluid tubes C but the acquisition of retest necessity of all the samples of the preceding rack L 1  is not completed. 
         [0145]    When it is determined that the retest is necessary for the sample tube T at the holding position  9  of the preceding rack L 1 , the sample tube T at the holding position  9  of the preceding rack L 1  is supplied to the measurement unit  31  on the downstream side, as shown in  FIG. 13B . In this case, the measurement unit  32  is vacant, so it is possible to initiate a washing for the measurement unit  32 . But, the following rack L 2  does not supply the washing fluid tube C to the measurement unit  32  and waits at the feeding position P 1 , since the retest necessity acquisition of all the samples of the preceding rack L 1  is not completed. 
         [0146]      FIG. 13C  is a view showing a state when the acquisition of the retest necessity of the sample tube T of all the holders of the preceding rack L 1  is completed and some of the samples in the sample tubes T are determined to be necessary to be retested. Such state corresponds to a state in which the CPU  401  is processing the completion waiting process of the aspiration for the retest of S 207  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing the washing of the measurement unit  32  on the upstream side of S 109  to S 112  of  FIG. 10  for the following rack L 2 . 
         [0147]    With reference to  FIG. 13C , the retest necessity is acquired for each of the samples in the sample tubes T held by the preceding rack L 1 , and the aspiration for the retesting the sample in the sample tube T at the holding position  9  is completed. The sample tube T at the holding position  10  is determined that the retest is necessary and is supplied to the measurement unit  31 . The following rack L 2  supplies the washing fluid tube C at the holding position  2  only to the measurement unit  32  since the retest necessity acquisition of all the samples of the preceding rack L 1  has been completed, but the retest is necessary for the sample of the preceding rack L 1 . 
         [0148]      FIG. 13D  is a view showing a state when the aspiration for the retest is completed for the sample tubes T of all the holders of the preceding rack L 1 . Such state corresponds to a state in which the CPU  401  is processing the process of S 208  of  FIG. 11A  for the preceding rack L 1 , and starting the washing process of the measurement unit  31  on the downstream side of S 115 , S 116  of  FIG. 10  for the following rack L 2 . 
         [0149]    In the preceding rack L 1 , the aspirations for the retests of the samples held by the holding positions  9  and  10  are completed, and therefore none of samples in the preceding rack L 1  needs to be aspirated for a retest once more. The preceding rack L 1  is then positioned at the collecting position P 4 , and pushed away to the left table  22 . In the following rack L 2 , the washing fluid tube C is supplied to the measurement unit  31  on the downstream side. 
         [0150]    As described above, when it is identified that the holder of the following rack L 2  includes one or more washing fluid tubes C and there is the preceding rack L 1 , the supply of the washing fluid tube C of the following rack L 2  to the measurement units  31 ,  32  is suspended until the retest necessity acquisition of all the samples of the preceding rack L 1  is completed. 
         [0151]    Furthermore, if one or more samples in the preceding rack L 1  is determined as necessary to be retested, the supply of the washing fluid tube C of the following rack L 2  is suspended for at least one measurement unit until the aspiration for all the retests of the preceding rack L 1  is completed. 
         [0152]    If the determination result of the retest necessity is unnecessary for all the samples of the preceding rack L 1 , the washing fluid tube C of the following rack L 2  is supplied to the measurement units  31 ,  32 . 
         [0153]    If the determination result of the retest necessity is necessary for a sample of the preceding rack L 1 , the retest of the sample is carried out. After the aspiration for the retest of the sample is completed and the aspiration for the retest is completed for all the samples of the preceding rack L 1 , the washing fluid tube C of the following rack L 2  is supplied to the measurement units  31 ,  32 . 
         [0154]    Furthermore, the following rack L 2  is waited at the feeding position P 1  and the preceding rack L 1  is waited in the transportation space P 5  until the acquisition of the retest necessity of the sample tube T of the preceding rack L 1  is completed. 
         [0155]    According to the present embodiment, if the following rack L 2  installed with the washing fluid tube C follows the preceding rack L 1  installed with the sample tube T, the washing by the following rack L 2  is suspended until the determination result of the retest necessity is acquired for all the samples of the preceding rack L 1 . Thus, a washing of a measurement unit is prevented to be initiated until all samples are determined as unnecessary to be retested. Therefore, any retest may not be interfered by a washing that has been already initiated, so the retest can be smoothly carried out. 
         [0156]    According to the present embodiment, the following rack L 2  is waited at the feeding position P 1  until the acquisition of the retest necessity of the preceding rack L 1  is completed, and thus the retest of the preceding rack L 1  can be smoothly carried out without inhibiting the transportation control of the preceding rack L 1 . 
         [0157]    According to the present embodiment, if the acquisition of the retest necessity is completed for all the sample tubes T of the preceding rack L 1  after the supply of the washing fluid tube C of the following rack L 2  is suspended, the washing fluid tube C of the following rack L 2  is automatically supplied to the measurement units  31 ,  32 , which alleviates the trouble of the user. 
         [0158]    According to the present embodiment, after executing the washing, the measurement units  31 ,  32  are automatically shut down and the information processing unit  4  is automatically shut down, so that the user can omit the operation of waiting for the washing process that takes a long time and then manually shutting down the power of the device. The trouble of the user thus can be alleviated. 
         [0159]    According to the present embodiment, in a configuration having two or more measurement units, if the retest necessity acquisition is completed for all samples in the preceding rack L 1  and some of the samples are determined to be necessary to be retested, the washing is started for only one measurement unit while the other measurement unit performs the aspiration for retest. Therefore, a time consumed for washing all measurement units can be minimized. 
         [0160]    The embodiment of the present invention has been described above, but the embodiment of the present invention is not limited thereto. 
         [0161]    For instance, the blood cell counting apparatus has been illustrated as the measurement unit in the embodiment described above, but the measurement unit may be a urine analyzer or an immunology analyzer measuring a serum. 
         [0162]    In the embodiment described above, the sample analyzer  1  in which the sample is aspirated by the piercing pipette  31   d ,  32   d  after the sample tube T is interiorly retrieved by the hand portions  31   a ,  32   a  of the measurement units  31 ,  32  has been illustrated, but the present invention may be applied to a sample analyzer in which the piercing pipette is arranged at the retrieving positions P 31   a , P 32   a  and the sample of the sample tube T is aspirated in a state where the sample tube T is held on the rack without interiorly retrieving the sample tube T. 
         [0163]    In the embodiment described above, the rack transporting portion  23  is controlled to position the washing fluid tube C at the feeding position P 1  without positioning at the retrieving positions P 31   a , P 32   a  of the measurement units  31 ,  32  so that the supply of the washing fluid to the measurement units  31 ,  32  is suspended, but the present invention is not limited to this embodiment. Alternatively, the rack transporting portion  23  may be configured to position the washing tubes C at the retrieving positions P 31   a , P 32   a , and the measurement units  31 ,  32  may be configured to avoid retrieving inside the washing fluid tube C of the holder of the rack L to suspend the supply of the washing fluid. Or the measurement unit  31 ,  32  may be configured to control the hand portions  31   a ,  32   a  not to position the washing fluid tube C at the aspirating positions P 31   c , P 32   c  in order to suspend the supply of the washing fluid. Or the measurement unit may be configured to control the piercing pipette  31   d ,  32   d  not to aspirate washing fluid in the washing fluid tube C for the same purpose. 
         [0164]    In the embodiment described above, the supplying order of the tube is determined by identifying the type of tube held in the rack L in order by the barcode unit B 2 , but the barcode may not be used. For instance, the information processing unit  4  may accept the measurement reservation of the sample and the washing reservation using the washing fluid, and the measurement units  31 ,  32  may be configured to execute the reserved operation accepted by the information processing unit  4  in the order specified by the user. In this case, the supplying order of the tube is determined based on the specified order of the reserved operation. 
         [0165]    In the embodiment described above, the barcode given to the tube is read on the rack transporting portion  23  connecting the right table  21  and the left table  22 , but the present invention is not limited thereto. For instance, the transport apparatus for supplying the rack L to the right table  21  may be connected to the upstream of the transportation unit  2 , and a barcode reader may be provided in a path between the transport apparatus and the right table  21 . 
         [0166]    In the embodiment described above, a mode of reading the barcode while transporting the rack L is shown, but a mode of including a hand held type barcode reader may be adopted. In such a mode, the barcodes of a plurality of tubes are read with the barcode reader in advance, and the tubes are arranged on the rack L in an order of reading the barcode. 
         [0167]    In the embodiment described above, in the configuration including two measurement units  31 ,  32 , if the retest is necessary for the sample of the preceding rack L 1 , the washing fluid tube C is supplied only to the measurement unit  32  on the upstream side before the aspiration for the retest of all the samples is completed, but the supply of the washing fluid tube C to all the measurement units  31 ,  32  may be suspended until the aspiration for the retest is completed for all the samples of the preceding rack L 1 . In this case, the flowchart of  FIG. 10  is modified to modified embodiment 1 in  FIG. 14 . In other words, if there is a sample that needs retest in the preceding rack L 1  in S 104  (S 104 : NO), the CPU  401  suspends the supply of the washing fluid to the measurement unit until the aspiration for the retest with respect to all the samples that need the retest is completed (S 121 ). After the aspiration for all the retests is completed (S 121 : YES), the CPU  401  executes washing on the measurement unit to be washed (S 105  to S 108 ). 
         [0168]    In the embodiment described above, the sample analyzer  1  including two measurement units  31 ,  32  is illustrated, but three or more measurement units may be arranged and a smear preparing apparatus may be additionally arranged. As shown in modified embodiment 2 of  FIG. 15 , a sample analyzer  500  including one measurement unit  503  may be adopted. In this case, a transportation unit  502  has a rack transporting portion  521  configured shorter than in the embodiment described above, but an information processing unit  504  and other configurations are configured similar to the above. 
         [0169]      FIG. 16A  is a view showing an arrangement rule of the rack L of the washing fluid tube C in the case of modified embodiment 2. The washing fluid tube C is installed at the holding position  1  positioned on the most downstream side in the transporting direction. 
         [0170]      FIG. 16B  is a flowchart showing a flow of the control operation of the rack L in the case of modified embodiment 2. The processes similar to the embodiment described above shown in  FIG. 9  are denoted with similar reference numerals, and the detailed description will be omitted. 
         [0171]    In the case of modified embodiment 2, which one of the washing and shutdown process or the sample process to be performed is determined according to the type of tube arranged at the holding position  1 . 
         [0172]    When the rack L is transported to the feeding position P 1  (S 1 ), the CPU  401  operates the rack transporting portion  23  to transport the same so that the holding position  1  of the rack L is positioned at the barcode reading position P 2  (S 71 ). The barcode information of the tube installed at the holding position  1  is then read by the barcode unit B 2 , and whether the washing fluid tube C is installed at the holding position  1  is determined (S 72 ). If the washing fluid tube C is installed at the holding position  1  (S 72 : YES), the CPU  401  initiates the washing and shutdown process (S 11 ). If the washing fluid tube C is not installed at the holding position  1  (S 72 : NO), the CPU  401  executes the normal sample process (S 21 ). In this case, the washing and shutdown process is carried out according to the flowchart shown in  FIG. 14 . In other words, the washing operation by the washing fluid tube C held in the following rack L is suspended until the aspiration for the retest is completed for all the sample tubes T held in the preceding rack L. The following holding position determination steps S 201 , S 202  in the normal sample process S 21  are modified to include the holding position  2 , so that the holding positions  2  to  10  are the target of determination. 
         [0173]    In modified embodiment 2, therefore, effects similar to the embodiment described above are obtained even with the configuration including one measurement unit. 
         [0174]    In the embodiment described above, the rack L includes holders for ten tubes, but the number of holders may be other numbers. The arrangement rule of the washing fluid tube C is to be arranged on the most downstream in the transporting direction of the rack L, but may be positioned on the most upstream or may be positioned at other positions. Furthermore, the arrangement rule of the washing fluid tube C on the rack L may not be defined. 
         [0175]    In the embodiment described above, the supply of the washing fluid tube C accommodated in the following rack L 2  to the measurement units  31 ,  32  is suspended when the sample tube T is held in the preceding rack L 1  and the washing fluid tube C is held in the following rack L 2 . However the supply of the washing fluid tube C to the measurement units  31 ,  32  may be suspended when both of the washing fluid tube C and the sample tube T is installed to the same rack L. 
         [0176]    As shown in modified embodiment 3 of  FIG. 16C , in the case of the rule in which the washing fluid tube C is arranged at the holding position  10 , whether the sample tube T is installed at any of the holding positions  1  to  9  is determined. If the sample tube T is installed, the supply of the washing fluid tube C to the measurement units  31 ,  32  is suspended until the aspiration for the retest of the sample tubes T at the holding positions  1  to  9  is completed. 
         [0177]      FIG. 17  is a flowchart showing a flow of the control operation of the rack L in the case of modified embodiment 3. 
         [0178]    With reference to  FIG. 17 , the CPU  401  performs the barcode reading of the tube installed in the holder of the rack L, and the measurement process as well as the retest process of the sample tube T installed in the rack L, (S 301  to S 306 ), similar to the embodiment described above. When the measurement is completed for all the sample tubes T accommodated in the rack L (S 306 : YES), the CPU  401  determines whether or not the washing fluid tube C is at the holding position  10  (S 307 ). 
         [0179]    If the washing fluid tube C is not at the holding position  10  (S 307 : NO), the CPU  401  operates the rack transporting portion  23  to transport the rack L to the collecting position P 4  (S 313 ). The CPU  401  then determines whether there is a following rack L (S 314 ), and the processing of the following rack L is performed. If the washing fluid tube C is at the holding position  10  (S 307 : YES), the CPU  401  determines whether or not the aspiration for the retest is completed for all the samples of the rack L (S 308 ). If the aspiration for the retest is not completed (S 308 : NO), the CPU  401  waits for the following processing until the aspiration for the retest is completed. If the aspiration for the retest is completed (S 308 : YES) for all the samples of the rack L, the CPU  401  supplies the washing fluid tube C at the holding position  10  to the measurement unit, and performs the washing process and the shutdown (S 309  to S 312 ). Such processes are similar to S 105  to S 108  of  FIG. 10 , and thus the detailed description will be omitted. 
         [0180]    In the case of modified embodiment 3, when the washing fluid tube C follows the sample tube T of the same rack L, the supply of the following washing fluid tube C to the measurement unit is suspended, and thus the washing is avoided from being automatically starting. Therefore, the retest can be smoothly carried out for all the sample tubes T of the preceding rack. 
         [0181]    In the embodiment described above, if the following rack L 2  is identified as holding the washing fluid tube C, the supply of the washing fluid tube C of the following rack L 2  to the measurement units  31 ,  32  is suspended until the acquisition of the retest necessity is completed or until the aspiration for the retest is completed if the acquisition of the retest necessity is not completed for all the samples of the preceding rack L 1 , but the supply of the washing fluid tube C to the measurement units  31 ,  32  may be skipped, as shown in modified embodiment 4 of  FIG. 18 . 
         [0182]    With reference to  FIG. 18 , in the case of modified embodiment 4, if the retest necessity acquisition complete flag for all the samples of the preceding rack L 1  is not set (S 103 : NO) after determining that the following rack L 2  includes the washing fluid tube C, the CPU  401  operates the rack transporting portion  23  to transport the following rack L 2  to the collecting position P 4  (S 131 ). The following rack L 2  transported to the collecting position P 4  is discharged to the left table  22  by a rack pushing mechanism  23   a . The supply of the washing fluid tube C to the measurement units  31 ,  32  is skipped in such manner, and the process with respect to the following rack L 2  is completed. 
         [0183]      FIG. 19  is a view showing an example of the operation state of the rack transporting portion  23  of the preceding rack L 1  and the following rack L 2  in the case of modified embodiment 4. 
         [0184]      FIG. 19A  shows a state similar to  FIG. 12B , and  FIG. 19B  shows a state similar to  FIG. 12C , and thus the description will be omitted. 
         [0185]      FIG. 19C  is a view showing a state of when the following rack L 2  is collected to the left table  22  while waiting for the retest necessity acquisition of the preceding rack L 1 . Such state corresponds to a state in which the CPU  401  is processing the completion waiting process of the aspiration for the retest of S 207  of  FIG. 11A , the retest process of  FIG. 11B , and the flag setting process of  FIG. 11C  in parallel for the preceding rack L 1  and processing the transportation to the collecting position P 4  of S 131  of  FIG. 18  for the following rack L 2 . The preceding rack L 1  has the measurement process of the sample tube T of all the holders at the holding positions  1  to  10  completed and waits in the transportation space P 5  of the rack transporting portion  23 . In this case, the preceding rack L 1  is determined that the retest necessity is already acquired and the retest is unnecessary for the sample tubes T at the holding positions  1  to  9 . The determination result on the necessity of retest is not yet acquired for the sample tube T at the holding position  10  of the preceding rack L 1 . The following rack L 2  skips the supply of the washing fluid tube C to the measurement units  31 ,  32  and is collected to the left table  22  since the retest necessity acquisition of the preceding rack L 1  is not completed when identified as including the washing fluid tube C. 
         [0186]      FIG. 19D  is a view showing a state of when the retest necessity is acquired for the sample tubes T of all the holders of the preceding rack L 1 . Such state corresponds to a state in which the retest process of  FIG. 11B  and the flag setting process of  FIG. 11C  are completed, and the CPU  401  is processing S 208  of  FIG. 11A  for the preceding rack L 1  and completed with processing for the following rack L 2 . The preceding rack L 1  is determined that the retest necessity is already acquired and the retest is unnecessary for the sample tubes T of all the holders at the holding positions  1  to  10 . Thus, the preceding rack L 1  is pushed away to the left table  22 . 
         [0187]    Therefore, if identified that the holder of the following rack L 2  includes the washing fluid tube C by the barcode unit B 2 , the supply of the washing fluid tube C of the following rack L 2  to the measurement units  31 ,  32  is skipped if the retest necessity acquisition of all the samples of the preceding rack L 1  is not completed. 
         [0188]    In the case of modified embodiment 4 as well, if the following rack L 2  in which the washing fluid tube C is installed follows the preceding rack L 1  in which the sample tube T is installed, the supply of the washing fluid tube C of the following rack L 2  is skipped and thus the washing is avoided from being automatically started, similar to the embodiment described above. Therefore, the retest can be smoothly carried out for all the sample tubes T of the preceding rack L 1 . 
         [0189]    In the embodiment described above, the following rack L 2  is evacuated to the feeding position P 1  and waited thereat until the acquisition of the retest necessity of the sample tube T of the preceding rack L 1  is completed, but may be waited at other positions on the rack transporting portion  23 . The following rack L 2  may be evacuated as needed with the transportation of the preceding rack L 1  without waiting at a predetermined position. 
         [0190]    In the embodiment described above, the sample tube T and the washing fluid tube C are installed in the rack L and supplied to the measurement units  31 ,  32 , but may not be installed in the rack L, and the sample tube T and the washing fluid tube C may be directly installed in the rack transporting portion  23  one at a time and transported to be supplied to the measurement units  31 ,  32 . 
         [0191]    Furthermore, in the embodiment described above, the presence or absence of the tube, and the type of sample tube T and washing fluid tube C is identified by the barcode unit B 2 , but may be identified with other identification means. For instance, an IC chip indicating the sample ID and the washing fluid ID may be arranged on the tube, and an IC chip reader may be used or an optical sensor for identifying the shape may be used with the shape of the tube differed between the sample and the washing fluid. A two-dimensional code arranged with dots such as the QR code (registered trademark) may be used in place of the linear barcode. 
         [0192]    In the embodiment described above, the measurement units  31 ,  32  and the information processing unit  4  automatically perform shut down after executing the washing, but may be restart rather than the shutdown, where the user may set whether to perform the shutdown or perform the restart according to the application of the information processing unit  4 . 
         [0193]    In the embodiment described above, the necessity of the retest is determined by the host computer  5 , and the determination result of the retest necessity is acquired by the information processing unit  4 , but the necessity of the retest may be determined by the information processing unit  4 . 
         [0194]    In the embodiment described above, the measurement units  31 ,  32  respectively perform the measurement of the sample and the process of the retest, but the measurement unit  32  on the upstream side may perform only the process of the sample measurement, and the measurement unit  31  on the downstream side may perform only the process of the retest. 
         [0195]    Furthermore, in the embodiment described above, whether the rack L performs the sample process or performs the washing and shutdown process is determined by identifying the sample ID and the washing fluid ID of the holding positions  1 ,  2  of the rack L, but determination may be made whether to perform the sample process or whether to perform the washing and shutdown process by the rack ID. 
         [0196]    The embodiment of the present invention may be appropriately modified within a scope of the technical idea described in the Claims.