Abstract:
A sample processing apparatus comprising: a plurality of testing units arranged along a transport path and each configured to perform at least one type of test; a plurality of transport units configured to collectively constitute the transport path and collectively function to deliver samples to the plurality of testing units for testing; and at least one processor of a computer system and at least one memory that stores programs executable by the at least one processor to: (a) determine a type of test required to be performed on a sample; (b) if a trouble of a transport unit is reported, determine whether there is an available testing unit performable of the required type of test to which the sample is deliverable; (c) if there is the available testing unit, instruct to transport the sample to the available testing unit.

Description:
RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2010-079195 filed on Mar. 30, 2010, the entire content of which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sample processing apparatus, a sample transporting method, and a non-transitory storage medium for transporting a sample to a testing unit. 
     2. Description of the Related Art 
     In Japanese Laid-Open Patent Publication No. 2002-318237, there is a description of a sample rack transport system which includes a transport apparatus in which a plurality of line units are connected in series, a supply section supplying a sample rack to the transport apparatus, and a controller for storing information relating to a processing status of the sample rack and controlling the transport apparatus. In this sample rack transport system, a transport line for transporting a sample rack and a return line for returning a sample rack to the upstream side of the transport line are configured by connecting the plurality of line units and sample racks can be transported to sample processing units corresponding to the respective line units via the transport line. 
     If trouble occurs during the transport of a sample rack in this sample rack transport system, after the system is restored from the trouble, the controller performs controls the transport apparatus so as to supply a sample rack to a sample processing unit which is to be the next transport destination on the basis information relating to the rack processing status. 
     However, in the above-described sample rack transport system, when trouble occurs during the transport of a sample rack, the transport operation of the sample rack by the sample rack transport system is completely stopped until the trouble is resolved. 
     SUMMARY OF THE INVENTION 
     The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary. 
     According to a first aspect of the present invention, a sample processing apparatus comprising: 
     a plurality of testing units arranged along a transport path and each configured to perform at least one type of test; 
     a plurality of transport units configured to collectively constitute the transport path and collectively function to deliver samples to the plurality of testing units for testing; and 
     at least one processor of a computer system and at least one memory that stores programs executable by the at least one processor to: 
     (a) determine a type of test required to be performed on a sample; 
     (b) if a trouble of a transport unit is reported, determine whether there is an available testing unit performable of the required type of test to which the sample is deliverable; 
     (c) if there is the available testing unit, instruct to transport the sample to the available testing unit. 
     According to a second aspect of the present invention, a sample transporting method executed in a sample processing apparatus comprising a plurality of testing units arranged along a transport path and each configured to perform at least one type of test and a plurality of transport units configured to collectively constitute the transport path and collectively function to deliver samples to the plurality of testing units for testing, 
     the method comprising computer-executable steps executed by at least one processor of a computer system to implement: 
     (a) determining a type of test required to be performed on a sample; 
     (b) if a trouble of a transport unit is reported, determining whether there is an available testing unit performable of the required type of test to which the sample is deliverable; 
     (c) if there is the available testing unit, instructing to transport the sample to the available testing unit. 
     According to a third aspect of the present invention, a non-transitory storage medium provided in a sample processing apparatus which comprises a plurality of testing units arranged along a transport path and each configured to perform at least one type of test and a plurality of transport units configured to collectively constitute the transport path and collectively function to deliver samples to the plurality of testing units for testing, 
     the storage medium storing programs executed by at least one processor of a computer system to: 
     (a) determine a type of test required to be performed on a sample; 
     (b) if a trouble of a transport unit is reported, determine whether there is an available testing unit performable of the required type of test to which the sample is deliverable; 
     (c) if there is the available testing unit, instruct to transport the sample to the available testing unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic plan view showing the overall configuration of a sample processing apparatus according to a first embodiment. 
         FIG. 2  is a plan view showing the configuration of a sample insertion and recovery apparatus according to the first embodiment. 
         FIG. 3  is a perspective view showing the appearance of a sample container. 
         FIG. 4  is a perspective view showing the appearance of a sample rack. 
         FIG. 5  is a plan view showing the configuration of a sample transport apparatus for a blood cell analysis apparatus according to the first embodiment. 
         FIG. 6  is a plan view showing the configuration of a sample transport apparatus for a smear preparation apparatus according to the first embodiment. 
         FIG. 7  is a block diagram showing the configuration of a measuring unit of the blood cell analysis apparatus according to the first embodiment. 
         FIG. 8  is a block diagram showing the configuration of an information processing unit of the blood cell analysis apparatus according to the first embodiment. 
         FIG. 9  is a block diagram showing the configuration of a system control apparatus according to the first embodiment. 
         FIG. 10  is a flowchart showing the flow of a sample discharge operation of the sample insertion and recovery apparatus according to the first embodiment. 
         FIG. 11  is a flowchart showing the flow of a measurement order obtaining operation of the system control apparatus according to the first embodiment. 
         FIG. 12  is a flowchart showing the flow of a first transport instruction operation of the system control apparatus according to the first embodiment. 
         FIG. 13  is a flowchart showing the flow of a first transport operation of the sample transport apparatus for the blood cell analysis apparatus according to the first embodiment. 
         FIG. 14  is a flowchart showing the flow of a transport destination change process when trouble occurs in the system control apparatus according to the first embodiment. 
         FIG. 15  is a flowchart showing the flow of a rack transport control operation of the blood cell analysis apparatus according to the first embodiment. 
         FIG. 16  is a flowchart showing the flow of a sample analysis operation of the blood cell analysis apparatus according to the first embodiment. 
         FIG. 17  is a flowchart showing the flow of a second transport instruction operation of the system control apparatus according to the first embodiment. 
         FIG. 18  is a flowchart showing the flow of a second transport operation of the sample transport apparatus according to the first embodiment. 
         FIG. 19  is a flowchart showing the flow of a rack sorting and recovery operation of the sample insertion and recovery apparatus according to the first embodiment. 
         FIG. 20  is a plan view showing the configuration of a sample insertion and recovery apparatus according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. 
     (First Embodiment) 
     This embodiment is a sample rack transport system which includes an insertion apparatus for inserting sample racks containing a plurality of samples, a sample transport apparatus transporting an inserted sample rack and supplying the sample rack to a measuring apparatus and a plurality of recovery apparatuses recovering sample racks to sort and recover sample racks into the plurality of recovery apparatuses in accordance with whether all the measurement items based on a measurement order are measured when trouble (abnormality) occurs. Here, in this embodiment, the trouble is not a small problem such as a mistake in the transport of sample racks, but is a severe problem which requires repair by a service man due to a physical breakdown of the transport mechanism of the sample transport apparatus. 
       FIG. 1  is a schematic plan view showing the overall configuration of a sample processing system  1  including the sample rack transport system according to this embodiment. As shown in  FIG. 1 , the sample rack transport system  100  includes a sample insertion and recovery apparatus  2 , sample transport apparatuses  3   a ,  3   b ,  3   c  and  4  and a system control apparatus  8 . In addition, the sample processing system  1  includes a sample rack transport system  100 , a blood cell analysis apparatus  5  and a smear preparation apparatus  6 . In addition, the sample processing system  1  according to this embodiment is connected to an examination information management apparatus  9  so as to communicate therewith via a communication network. 
     &lt;Configuration of Sample Insertion and Recovery Apparatus  2 &gt; 
       FIG. 2  is a plan view showing the configuration of the sample insertion and recovery apparatus  2  according to this embodiment. The sample insertion and recovery apparatus  2  includes a sample insertion unit  21 , a pre-processing unit  22  and sample recovery units (rack recovery section)  23  and  24 . In the sample insertion and recovery apparatus  2 , sample racks can be placed which accommodate a plurality of sample containers. Such a sample insertion and recovery apparatus  2  has a sample insertion unit group  2 A including the sample insertion unit  21  and the pre-processing unit  22  and a sample recovery unit group  2 B including the sample recovery units  23  and  24 . 
       FIG. 3  is a perspective view showing the appearance of a sample container T and  FIG. 4  is a perspective view showing the appearance of a sample rack L. As shown in  FIG. 3 , the sample container T has a tubular shape and the upper end thereof is opened. A blood sample collected from a patient is contained in the sample container and the opening at the upper end is sealed by a cap section CP. The sample container T is made of glass or a synthetic resin having translucency and the blood sample therein can be visually confirmed. In addition, a barcode label BL 1  is adhered to the side surface of the sample container T. A barcode (sample barcode) showing a sample ID is printed on this barcode label BL 1 . In the sample rack L, 10 sample containers T can be arranged in parallel and held. In the sample rack L, sample containers T are held in a vertical state (erect state). In addition, a barcode label BL 2  is adhered to the side surface of the sample rack L. A barcode (rack barcode) showing a rack ID is printed on this barcode label BL 2 . 
     As shown in  FIG. 2 , the sample insertion unit  21  has a concave-shaped rack placement section  211  for placing a sample rack L accommodating sample containers T. This rack placement section  211  has a rectangular shape and a plurality of sample racks L can be placed at the same time therein. Sample racks L are placed in the rack placement section  211  so that sample containers T are arranged in parallel in the transverse direction. The rack placement section  211  is provided with sensors  212  and  213  for detecting a sample rack L and engagement sections  211   a  for transferring a sample rack L. The sensors  212  and  213  are optical sensors. The sensor  212  includes a light-emitting section  212   a  and a light-receiving section  212   b , and the sensor  213  includes a light-emitting section  213   a  and a light-receiving section  213   b . The light-emitting section  212   a  is disposed on the front-left side of the rack placement section  211  and the light-receiving section  212   b  is disposed on the central-right side of the rack placement section  211 . In addition, the light-emitting section  213   a  is disposed on the rear-left side of the rack placement section  211  and the light-receiving section  213   b  is disposed on the central-right side of the rack placement section  211 . The light-emitting section  212   a  is disposed so as to emit light in the diagonally backward right direction and the light-receiving section  212   b  is disposed so as to receive this light across the rack placement section  211 . The light-emitting section  213   a  is disposed so as to emit light in the diagonally forward right direction and the light-receiving section  213   b  is disposed so as to emit this light across the rack placement section  211 . Accordingly, the light emitted from the light-emitting section  212   a  or  213   a  is shielded by a sample rack L placed in the rack placement section  211  and the sample rack L is detected by the rack sensor  212  or  213  due to a lowering of the light-reception level of the light-receiving section  212   b  or  213   b . The sample rack L detected by the rack sensor  212  or  213  engages with the engagement sections  211   a  and moves forward and backward while the engagement sections  211   a  engage with the sample rack L. Therefore, the sample rack L is transferred on the rack placement section  211 . 
     The position on the innermost side of the rack placement section  211  serves as a rack output position  214  for outputting a sample rack L to the left side. Such a rack output position  214  is provided with a protrusion section  215  which is movable left- and rightward. This protrusion section  215  waits at the position near the right end of the rack output position  214  until a sample rack L is transferred to the rack output position  214 . When the sample rack L reaches the rack output position  214 , the protrusion section moves leftward. The sample rack L is pushed by the protrusion section  215  and moves leftward. In addition, the walls on the both right and left sides of the rack output position  214  are missing. Accordingly, the sample rack L pushed by the protrusion section  215  is output from the sample insertion unit  21 . As shown in  FIG. 2 , the pre-processing unit  22  is provided on the left side of the sample insertion unit  21  and the wall on the right side of the pre-processing unit  22  is partially missed, so the sample rack L output from the rack output position  214  is introduced into the pre-processing unit  22 . 
     In addition, two parallel belt conveyors, that is, a first transport line  216  and a second transport line  217  are provided in front of the rack placement section  211 . Portions on both right and left sides of the first transport line  216  and the second transport line  217  of the wall surrounding the rack placement section  211  of the sample insertion unit  21  are missed to introduce sample racks L into the first transport line  216  and the second transport line  217  and to discharge sample racks L to another unit from the first transport line  216  and the second transport line  217 . The bottom surface of the rack placement section  211  and the heights of the first transport line  216  and the second transport line  217  are uniformized and almost the uniform plane is formed. In addition, the sample insertion unit  21  is provided with a rack transfer section  218  for transferring a sample rack L introduced into the first transport line  216  or the second transport line  217  in the backward direction. Such a rack transfer section  218  has a horizontally long rod shape and is movable forward and backward in the range from the second transport line  217  to the central position in the front-back direction of the rack placement section  211 . Due to the backward movement of the rack transfer section  218  which is displaced in front of a sample rack L introduced into the first transport line  216  or the second transport line  217 , the rack transfer section  218  is brought into contact with the front surface of the sample rack L, and due to further backward movement of the rack transfer section  218 , the sample rack L is pushed and moved backward. Accordingly, the sample rack L is transferred backward up to a position past the engagement sections  211   a  and then the sample rack L is transferred up to the rack output position  214  by the engagement sections  211   a . In this manner, the sample insertion unit  21  can directly output a sample rack L which is introduced by the first transport line  216  or the second transport line  217  to the sample recovery unit  23  on the right side, and can transfer a sample rack L on the first transport line  216  or the second transport line  217  up to the rack output position  214  and then output the sample rack to the pre-processing unit  22  on the left side. 
     The sample insertion unit  21  having such a configuration includes a control section  21   a  including a CPU, a memory and the like. The above-described mechanisms in the sample insertion unit  21  are controlled by this control section  21   a . In addition, the sample insertion unit  21  includes an Ethernet (registered trade name) interface and is connected to an information processing unit  54  and the system control apparatus  8  via a LAN so as to communicate therewith. The sample insertion unit  21  is provided with an operation panel  21   b . A user can give an instruction for starting or ending sample processing to the sample processing system  1  by operating the operation panel  21   b.    
     The pre-processing system  22  is connected to the left side of the sample insertion unit  21 . A sample rack L output to the left side from the rack output position  214  is introduced into the pre-processing unit  22 . Such a pre-processing unit  22  includes a rack placement section  221 , which can accommodate a plurality of sample racks L and has a quadrangular shape in a planar view. In addition, the pre-processing unit  22  includes a barcode reading section  22   b  on the inside of the rack placement section  221 . Such a barcode reading section  22   b  can read sample barcodes of a plurality of sample containers T accommodated in a sample rack L at the same time and can also read a rack barcode of the sample rack L. Such a barcode reading section  22   b  is provided with an optical sensor (not shown) for detecting a sample container T. When a sample rack L reaches a position at which the barcode reading section  22   b  reads a barcode, whether there is a sample container T is detected by the optical sensor. In addition, the barcode reading section  22   b  includes a horizontal rotating mechanism (not shown) which horizontally rotates a plurality of sample containers T immediately above the barcode reading position on the innermost side of the rack placement section  221 . A sample rack L output from the rack output position  214  of the rack insertion unit  21  is introduced leftward into the pre-processing unit  22  and reaches the barcode reading position. Then, while the horizontal rotating mechanism horizontally rotates a sample container T accommodated in the sample rack L, the barcode reading section  22   b  reads out a sample ID from a barcode label BL 1  and reads out a rack ID from a barcode label BL 2  of the sample rack L. 
     When the sample rack L reaches the barcode reading position, whether there is a sample container T is detected by the above-described optical sensor and the barcode reading section  22   b  continuously reads a sample barcode of each of the sample containers T plural times. When data of the sample IDs, each of which is read plural times matches, the reading of the sample barcode is regarded as successful and the sample IDs and the read rack ID are transmitted to the system control apparatus  8 . 
     Engagement sections  221   a  protrude from both right and left walls of the rack placement section  221 . Such engagement sections  221   a  engage with a sample rack L of which a rack barcode and sample barcodes have been read by the barcode reading section  22   b  and moves forward. Accordingly, the sample rack L moves forward on the rack placement section  221 . The position on the foremost side of the rack placement section  221  serves as a rack output position  222 . A transport line  223  which is a belt conveyor is provided in front of this rack output position  222  and a partition section  224  having a wall shape protrudes between the transport line  223  and the rack output position  222 . The partition section  224  is provided with a protrusion section  225  which is movable left- and rightward. This protrusion section  225  waits at the position near the right end of the rack output position  222  until a sample rack L is transferred to the rack output position  222 . After the sample rack L reaches the rack output position  222 , the protrusion section moves leftward. The sample rack L is pushed by the protrusion section  225  and moves leftward. In addition, the walls on the both right and left sides of the rack output position  222  are missing. Accordingly, the sample rack L pushed by the protrusion section  225  is output from the pre-processing unit  22 . As shown in  FIG. 1 , the sample transport apparatus  3   a  is connected to the left side of the pre-processing unit  22  and the rack output position  222  linearly connects with an overtaking line to be described later of the sample transport apparatus  3   a . Accordingly, the sample rack L output from the rack output position  222  is introduced into the overtaking line of the sample transport apparatus  3   a.    
     In addition, a barcode reader  222   a  for reading a rack barcode is provided near the rack output position  222 . This barcode reader  222   a  reads the rack ID of a sample rack L transported to the rack output position  222  and the read rack ID is transmitted to the system control apparatus  8 . As will be described later, the system control apparatus  8  receives this rack ID and decides a transport destination of the sample rack L in accordance with the rack ID. 
     In addition, walls on both right and left sides of the transport line  223  are missed and the transport line  223  linearly connects with a return line to be described later of the sample transport apparatus  3   a  and the above-described second transport line  217  of the sample insertion unit  21 . Accordingly, the transport line  223  receives a sample rack L from the return line of the sample transport apparatus  3   a  and discharges this sample rack L to the second transport line  217  of the sample insertion unit  21 . 
     The pre-processing unit  22  having such a configuration includes a control section  22   a  including a CPU, a memory and the like. The above-described mechanisms in the pre-processing unit  22  are controlled by this control section  22   a . In addition, the pre-processing unit  22  includes an Ethernet (registered trade name) interface and is connected to the information processing unit  54  and the system control apparatus  8  via a LAN so as to communicate therewith. 
     On the right side of the sample insertion unit  21 , sample recovery units  23  and  24  are laterally arranged side by side. The sample insertion unit  21  is connected to the leftmost sample recovery unit  23 . These sample recovery units  23  and  24  have the same configuration as that of the rack insertion unit  21 . That is, the sample recovery units  23  and  24  include concave-shaped rack placement sections  231  and  241  for placing sample racks L, engagement sections  231   a  and  241   a  for transferring sample racks L placed in the rack placement sections  231  and  241  backward, sensors  232  and  233  and  242  and  243  for detecting sample racks L, first transport lines  236  and  246  and second transport lines  237  and  247  which are provided in front of the rack placement sections  231  and  241  to transport sample racks L in the transverse direction, and rack transfer sections  238  and  248  for transferring sample racks L, which are introduced into the first transport lines  236  and  246  or the second transport lines  237  and  247 , to the rack placement sections  231  and  241 , respectively. The sample recovery units  23  and  24  are connected so that the first transport lines  236  and  246  linearly connect with each other and the second transport lines  237  and  247  linearly connect with each other. 
     The sample recovery units  23  and  24  include control sections  23   a  and  24   a  including a CPU, a memory and the like, respectively. The above-described mechanisms in the sample recovery units  23  and  24  are controlled by these control sections  23   a  and  24   a . In addition, the respective sample recovery units  23  and  24  include an Ethernet (registered trade name) interface and are connected to the information processing unit  54  and the system control apparatus  8  via a LAN so as to communicate therewith. 
     The sample recovery unit  24  is used to recover a sample rack L in which the necessary measurement has been completed. In addition, the sample recovery unit  23  is used to recover a sample rack L in which the necessary measurement has not been completed due to the occurrence of trouble in the sample transport apparatus  3   a ,  3   b  or  3   c.    
     &lt;Configurations of Sample Transport Apparatuses  3   a ,  3   b  and  3   c&gt;   
     Next, the configurations of the sample transport apparatuses  3   a ,  3   b  and  3   c  will be described. As shown in  FIG. 1 , the sample rack transport system  100  includes the sample transport apparatuses  3   a ,  3   b  and  3   c . The sample transport apparatuses  3   a ,  3   b  and  3   c  are disposed in front of three measuring units  51 ,  52  and  53  of the blood cell analysis apparatus  5 , respectively. The neighboring sample transport apparatuses are connected to each other to deliver and receive a sample rack L. In addition, the rightmost sample transport apparatus  3   a  is connected to the above-described sample insertion and recovery apparatus  2  to introduce a sample rack L discharged from the sample insertion and recovery apparatus  2  and to output a sample rack L to the sample insertion and recovery apparatus  2 . 
       FIG. 5  is a plan view showing the configurations of the sample transport apparatuses  3   a ,  3   b  and  3   c . Here, the sample transport apparatus  3   a  which is disposed in front of the measuring unit  51  will be described, but the sample transport apparatuses  3   b  and  3   c  which are disposed in front of the measuring units  52  and  53 , respectively, have the same configuration. As shown in  FIG. 5 , the sample transport apparatus  3   a  includes a transport mechanism  31  transporting a sample and a control section  32  controlling the transport mechanism  31 . 
     The transport mechanism  31  includes a pre-analysis rack holding section  33  capable of temporarily holding a sample rack L which holds a sample container T containing a sample before analysis, a post-analysis rack holding section  34  capable of temporarily holding a sample rack L which holds a sample container T in which a sample has been suctioned by the corresponding measuring unit  51 , a rack transport section  35  which horizontally and linearly moves a sample rack L in the direction of the arrow X in the drawing to supply the sample rack to the measuring unit  51  and transports the sample rack L received from the pre-analysis rack holding section  33  to the post-analysis rack holding section  34 , a rack overtaking transport section  321  which introduces a sample rack L from the apparatus (any one of the sample insertion and recovery apparatus  2  and the sample transport apparatus  3   a  and  3   b ) further to the upstream side of the transport and discharges the sample rack L to the apparatus (any one of the sample transport apparatuses  3   b  and  3   c  and the sample transport apparatus  4 ) further to the downstream side of the transport without supply of a sample contained in this sample rack L to the measuring unit  51 , and a rack return transport section  331  which introduces a sample rack L from the apparatus (any one of the sample transport apparatuses  3   b  and  3   c  and the sample transport apparatus  4 ) further to the downstream side of the transport and discharges the sample rack L to the apparatus (any one of the sample insertion and recovery apparatus  2  and the sample transport apparatus  3   a  and  3   b ) further to the upstream side of the transport without supply of a sample contained in this sample rack L to the measuring unit  51 . Each of the rack overtaking transport section  321  and the rack return transport section  331  have a transport belt for transporting a rack and a stepping motor driving the transport belt. The rack overtaking transport section  321  transports a sample rack L by driving the transport belt with the stepping motor in the transport downstream direction. In addition, the rack return transport section  331  transports a sample rack L by driving the transport belt with the stepping motor in the transport upstream direction. 
     When a sample rack L in the post-analysis rack holding section  34  is detected by optical sensors  34   a  and  34   b  including a light-emitting section and a light-receiving section, rack feeding mechanisms  34   c  move while engaging with the rear ends of the sample rack L and thus the sample rack L is positioned at any one of a rack overtaking position  321   a  and a rack return position  331   a . Sensors  321   b  and  331   b  are provided near the rack overtaking position  321   a  and the rack return position  331   a , respectively, and can detect the fact that a sample rack L has been positioned at the above position. 
     The control section  32  includes a CPU, a ROM, a RAM and the like (not shown). A control program of the transport mechanism  31  which is stored in the ROM can be executed by the CPU. In addition, such a control section  32  includes an Ethernet (registered trade name) interface and is connected to the information processing unit  54  and the system control apparatus  8  via a LAN so as to communicate therewith. 
     The sample transport apparatus  3   a  transports a sample rack L, which is transported from the sample insertion and recovery apparatus  2 , to a pre-analysis rack output position  323  by the rack overtaking transport section  321 , transfers the sample rack to the pre-analysis rack holding section  33  by a rack output section  322 , outputs this sample rack L to the rack transport section  35  from the pre-analysis rack holding section  33  by rack feeding sections  33   b , and transports the sample rack by the rack transport section  35  to supply a sample to the corresponding measuring unit  51  ( 52 ,  53 ) of the blood cell analysis apparatus  5 . A sensor  324  capable of detecting the fact that a sample rack L is positioned at the position  323  is provided near the pre-analysis rack output position  323 . In addition, the sample rack L containing the sample in which the suction has been completed is transferred to a post-analysis rack output position  391  by the rack transport section  35  and is output to the post-analysis rack holding section  34  by a rack output section  39 . The sample rack L held in the post-analysis rack holding section  34  is transferred to the rack overtaking transport section  321  and is discharged to the subsequent apparatus by the rack overtaking transport section  321  when the sample which is contained in this sample rack L is required to be measured by the measuring unit  52  or  53  on the transport direction downstream side or to be provided to the preparation of a smear by the smear preparation apparatus  6 . When there is no need to perform the measurement by the measuring unit  52  or  53  on the transport direction downstream side and the preparation of a smear by the smear preparation apparatus  6  on all of the samples which are held in the sample rack L held in the post-analysis rack holding section  34 , the sample rack L is transferred to the rack return transport section  331  and is discharged to the preceding apparatus (on the upstream side in the transport direction) by the rack return transport section  331 . In addition, when the sample rack L containing a sample to be processed by the measuring unit  52  or  53  further to the downstream side of the transport or by the smear preparation apparatus  6  is received from the preceding apparatus, this sample rack L is transported in the direction of the arrow X 1  by the rack overtaking transport section  321  and is directly discharged to the subsequent apparatus  3 . When the sample rack L which is recovered by the sample insertion and recovery apparatus  2  is received from the subsequent apparatus, this sample rack L is transported in the direction of the arrow X 2  by the rack return transport section  331  and is directly discharged to the preceding sample insertion and recovery apparatus  2  or sample transport apparatus  3 . 
     In the transport mechanism  31 , the rack feeding sections  33   b , the rack transport section  35  and the rack output section  39  are controlled by the information processing unit  54  of the blood cell analysis apparatus  5 . The other parts in the transport mechanism  31  are controlled by the control section  32 . 
     &lt;Configuration of Sample Transport Apparatus  4 &gt; 
     As shown in  FIG. 1 , the sample transport apparatus  4  is disposed in front of the smear preparation apparatus  6 . This sample transport apparatus  4  is connected to the sample transport apparatus  3   c  at the right end thereof. 
       FIG. 6  is a plan view showing the configuration of the sample transport apparatus  4 . The sample transport apparatus  4  includes a transport mechanism  41  transporting a sample and a control section  42  controlling the transport mechanism  41 . The transport mechanism  41  includes a pre-processing rack holding section  43  capable of temporarily holding a sample rack L which holds a sample container T containing a sample before preparation of a smear, a post-processing rack holding section  44  capable of temporarily holding a sample rack L which holds a sample container T in which a sample has been suctioned by the smear preparation apparatus  6 , a rack transport section  45  which horizontally and linearly moves a sample rack L in the X 1  direction to supply the sample to the smear preparation apparatus  6  and transports the sample rack L received from the pre-processing rack holding section  43  to the post-processing rack holding section  44 , a rack overtaking transport section  421  which introduces a sample rack L from the sample transport apparatus  3   c  further to the upstream side of the transport and transports the sample rack L in the X 1  direction, and a rack return transport section  431  which discharges a sample rack L to the sample transport apparatus  3   c  further to the upstream side of the transport in order to recover the sample rack L in which the preparation of smears of samples has been completed by the sample insertion and recovery apparatus  2 . The sample transport apparatus  4  is different from the sample transport apparatuses  3   a ,  3   b  and  3   c  in sizes, shapes and positions of the constituent components. However, since the functions are the same, the description of the configuration thereof will be omitted. 
     The sample transport apparatus  4  introduces a sample rack L, which is discharged from the sample transport apparatus  3   c  on the upstream side, by the rack overtaking transport section  421 , transfers the sample rack to the pre-processing rack holding section  43  by a rack output section (not shown), outputs this sample rack L to the rack transport section  45  from the pre-processing rack holding section  43 , and transport the sample rack by the rack transport section  45  to supply a sample to the smear preparation apparatus  6 . In addition, the sample rack L containing the sample in which the suction has been completed is transported by the rack transport section  45  and is output to the post-processing rack holding section  44  by the rack output section (not shown). The sample rack L held in the post-processing rack holding section  44  is transferred to the rack return transport section  431  and is discharged to the preceding sample transport apparatus  3   c  (on the upstream side in the transport direction) by the rack return transport section  431 . 
     &lt;Configuration of Blood Cell Analysis Apparatus  5 &gt; 
     The blood cell analysis apparatus  5  is an optical flow cytometry type multiple blood cell analysis apparatus. This apparatus obtains side-scattered light intensity, fluorescence intensity and the like with respect to blood cells included in a blood sample, classifies blood cells included in the sample on the basis of the above obtained results, counts the number of blood cells for each kind, and creates and displays a scattergram in which the classified blood cells are colored in different colors for each kind. Such a blood cell analysis apparatus  5  includes the measuring units  51 ,  52  and  53  which measure a blood sample and the information processing unit  54  which processes measurement data output from the measuring units  51 ,  52  and  53  and displays a blood sample analysis result. 
     As shown in  FIG. 1 , the blood cell analysis apparatus  5  includes the three measuring units  51 ,  52  and  53  and the single information processing unit  54 . The information processing unit  54  is connected to the three measuring units  51 ,  52  and  53  so as to communicate therewith and can control the operations of the three measuring units  51 ,  52  and  53 . In addition, the information processing unit  54  is connected to the three sample transport apparatuses  3   a ,  3   b  and  3   c  which are disposed in front of the three measuring units  51 ,  52  and  53 , respectively, so as to communicate therewith. 
       FIG. 7  is a block diagram showing the configuration of the measuring unit  51 . As shown in  FIG. 7 , the measuring unit  51  has a sample suction section  511  suctioning blood which is a sample from the sample container (blood collection tube) T, a specimen preparation section  512  preparing a measurement specimen which is used in measurement from the blood suctioned by the sample suction section  511  and a detecting section  513  detecting blood cells from the measurement specimen prepared by the specimen preparation section  512 . In addition, the measuring unit  51  further has an intake port (not shown) for taking a sample container T which is accommodated in a sample rack L transported by the rack transport section  35  of the sample transport apparatus  3   a  into the measuring unit  51  and a sample container transport section  515  which takes a sample container T from a sample rack L into the measuring unit  51  and transports the sample container T up to a position at which the sample suction section  511  performs suction. 
     A suction tube (not shown) is provided at the tip end of the sample suction section  511 . In addition, the sample suction section  511  is vertically movable and is configured to move downward so that the suction tube penetrates a cap section CP of a sample container T transported up to the suction position and suctions blood in the sample container. 
     The specimen preparation section  512  includes a plurality of reaction chambers (not shown). In addition, the specimen preparation section  512  is connected to reagent containers (not shown) and can supply reagents such as a dyeing reagent, a hemolytic agent and a diluent solution to the reaction chambers. The specimen preparation section  512  is also connected to the suction tube of the sample suction section  511  and can supply a blood sample suctioned by the suction tube to the reaction chambers. Such a specimen preparation section  512  mixes and stirs a sample and a reagent in the reaction chamber and prepares a specimen (measurement specimen) for the measurement by the detecting section  513 . 
     The detecting section  513  can perform RBC (red blood cells) detection and PLT (platelets) detection by a sheath flow DC detection method. In the RBC and PLT detection by this sheath flow DC detection method, a measurement specimen in which a sample and a diluent solution are mixed is measured and measurement data obtained by the measurement is analyzed and processed by the information processing unit  54 , and thus the RBC and PLT measurement is performed. In addition, the detecting section  513  can perform HGB (hemoglobin) detection by a SLS-hemoglobin method and is configured to perform WBC (white blood cells) detection by a flow cytometry method using a semiconductor laser. In this detecting section  513 , a measurement specimen in which a sample, a hemolytic agent and a diluent solution are mixed is measured and measurement data obtained by the measurement is analyzed and processed by the information processing unit  54 , and thus the WBC measurement is performed. The RBC, PLT, HGB and WBC are measured when a measurement item complete blood count (CBC) is designated. 
     The sample container transport section  515  includes a hand section  515   a  capable of gripping a sample container T. The hand section  515   a  includes a pair of gripping members which are disposed to be opposed to each other, and can move the gripping members closer to each other and separate the gripping members from each other. When such gripping members are moved closer to each other while gripping a sample container T, the sample container T can be gripped. In addition, the sample container transport section  515  can move the hand section  515   a  in the vertical direction and in the forward and backward directions (Y direction) and can oscillate the hand section  515   a . Accordingly, when a sample container T which is accommodated in a sample rack L and is positioned at a sample supply position is gripped by the hand section  515   a , and in this state, when the hand section  515   a  is moved upward to remove the sample container T from the sample rack L and is oscillated, the sample in the sample container T can be stirred. 
     In addition, the sample container transport section  515  includes a sample container setting section  515   b  having a hole into which a sample container T can be inserted. The sample container T gripped by the above-described hand section  515   a  is moved after completion of stirring and the gripped sample container T is inserted into the hole of the sample container setting section  515   b . Then, by separating the gripping members from each other, the sample container T is set in the sample container setting section  515   b . Such a sample container setting section  515   b  can horizontally move in the Y direction by a power of a stepping motor (not shown). In the measuring unit  51 , a barcode reading section  516  is provided. 
     The sample container setting section  515   b  can move to a barcode reading position  516   a  near the barcode reading section  516  and to a position  511   a  at which the sample suction section  511  performs suction. When the sample container setting section  515   b  moves to the barcode reading position  516   a , a set sample container T is horizontally rotated by the rotating mechanism (not shown) and a sample barcode is read by the barcode reading section  516 . Accordingly, even when the barcode label BL 1  of the sample container T is positioned on the opposite side to the barcode reading section  516 , the barcode label BL 1  can turn toward the barcode reading section  516  by rotating the sample container T and the sample barcode can be read by the barcode reading section  516 . When the sample container setting section  515   b  moves to the suction position, the sample is suctioned from a set sample container T by the sample suction section  511 . 
     The measuring units  52  and  53  have the same configuration as that of the measuring unit  51  and include a sample suction section, a specimen preparation section, a detecting section and a sample container transport section. However, the detecting section of the measuring unit  52  is different from the detecting section  513  of the measuring unit  51  and can perform a white blood cell-5-classification (measurement item DIFF) as well as CBC. In greater detail, the detecting section of the measuring unit  52  is configured to perform detection of WBC (white blood cells), NEUT (neutrophils), LYMPH (lymphocytes), EO (eosinophiles), BASO (basophils) and MONO (monocytes) by a flow cytometry method using a semiconductor laser. In such a detecting section of the measurement unit  52 , a measurement specimen in which a dyeing reagent, a hemolytic agent and a diluent solution are mixed is measured and measurement data obtained by the measurement is analyzed and processed by the information processing unit  54 , and thus the measurement of NEUT, LYMPH, EO, BASO, MONO and WBC is performed. 
     The detecting section of the measuring unit  53  is different from the detecting sections of the measuring units  51  and  52  and can measure reticulocytes (RET) in addition to CBC and DIFF. In order to perform the measurement of RET, a measurement specimen is prepared by mixing a reagent for RET measurement and a sample and the measurement specimen is supplied to an optical detecting section for WBC/DIFF (white blood cell-5-classification) detection of the detecting section. 
     Next, the configuration of the information processing unit  54  will be described. The information processing unit  54  is composed of a computer.  FIG. 8  is a block diagram showing the configuration of the information processing unit  54 . The information processing unit  54  is realized by a computer  54   a . As shown in  FIG. 8 , the computer  54   a  includes a main body  541 , an image display section  542  and an input section  543 . The main body  541  includes a CPU  541   a , a ROM  541   b , a RAM  541   c , a hard disk  541   d , a reading device  541   e , an I/O interface  541   f , a communication interface  541   g  and an image output interface  541   h . The CPU  541   a , the ROM  541   b , the RAM  541   c , the hard disk  541   d , the reading device  541   e , the I/O interface  541   f , the communication interface  541   g  and the image output interface  541   h  are connected to each other by a bus  541   j.    
     The reading device  541   e  reads out a computer program  544   a  for prompting the computer to function as the information processing unit  54  from a portable recording medium  544  and can install the computer program  544   a  on the hard disk  541   d.    
     &lt;Configuration of Smear Preparation Apparatus  6 &gt; 
     The smear preparation apparatus  6  suctions a blood sample from a sample container T in a sample rack L, drops the sample onto a glass slide, thinly extends the blood sample on the glass slide and dries the sample. Then, the smear preparation apparatus supplies a dyeing solution to the glass slide to dye the blood on the glass slide, thereby preparing a smear. 
     &lt;Configuration of System Control Apparatus  8 &gt; 
     The system control apparatus  8  is composed of a computer and controls the entire sample processing system  1 . This system control apparatus  8  receives the number of a sample rack L from the sample insertion and recovery apparatus  2  and decides the transport destination of the sample rack L. In addition, the system control apparatus  8  monitors operation states of the respective apparatuses in the sample processing system  1 , and when trouble occurs in the respective apparatuses, the system control apparatus can immediately detect the trouble. 
       FIG. 9  is a block diagram showing the configuration of the system control apparatus  8  according to this embodiment. The system control apparatus  8  is realized by a computer  8   a . As shown in  FIG. 9 , the computer  8   a  includes a main body  81 , an image display section  82  and an input section  83 . The main body  81  includes a CPU  81   a , a ROM  81   b , a RAM  81   c , a hard disk  81   d , a reading device  81   e , an I/O interface  81   f , a communication interface  81   g  and an image output interface  81   h . The CPU  81   a , the ROM  81   b , the RAM  81   c , the hard disk  81   d , the reading device  81   e , the I/O interface  81   f , the communication interface  81   g  and the image output interface  81   h  are connected to each other by a bus  81   j.    
     The reading device  81   e  reads out a system control program  84   a  for prompting the computer to function as the system control apparatus  8  from a portable recording medium  84  and can install the system control program  84   a  on the hard disk  81   d.    
     &lt;Configuration of Examination Information Management Apparatus  9 &gt; 
     The examination information management apparatus  9  is an apparatus which manages information relating to examinations in facilities, that is, a so-called laboratory information system (LLS), and is connected not only to the blood cell analysis apparatus  5 , but also to another clinical sample examination apparatus. Such an examination information management apparatus  9  receives a measurement order, which is input from an operator or is transmitted from another apparatus such as an electronic health record system, and stores and manages the measurement order. Further, the examination information management apparatus  9  receives an order request from the system control apparatus  8 , transmits the requested measurement order to the system control apparatus  8 , receives an analysis result from the blood cell analysis apparatus  5 , and stores and manages this analysis result. 
     The examination information management apparatus  9  is composed of a computer and includes a CPU, a ROM, a RAM, a hard disk, a communication interface and the like. The communication interface is connected to the above-described LAN and can communicate with the system control apparatus  8  and the information processing unit  54  of the blood cell analysis apparatus  5 . In addition, measurement orders are stored in the hard disk. In the measurement order, a sample ID and information regarding measurement items of an execution target are included. When receiving request data of a measurement order including a sample ID from another apparatus, the examination information management apparatus  9  reads out measurement data corresponding to this sample ID from the hard disk and transmits the measurement data to the apparatus which is the request source. Since the configuration of the examination information management apparatus  9  is the same as the configurations of the above-described other computers, the description thereof will be omitted. 
     [Operation of Sample Processing System] 
     Hereinafter, the operation of the sample processing system  1  according to this embodiment will be described. 
     &lt;Sample Discharge Operation of Sample Insertion and Recovery Apparatus  2 &gt; 
       FIG. 10  is a flowchart showing the flow of a sample discharge operation of the sample insertion and recovery apparatus  2 . When sample processing is started by the sample processing system  1 , first, an operator operates the operation panel  21   b  of the sample insertion unit  21  to give a sample processing start instruction to the sample processing system  1 . In this state, when a sample rack L is inserted into the sample insertion unit  21 , the sample rack L placed in the rack placement section  211  is detected by the sensors  212  and  213  (Step S 101 ). A control program which is executed by the control section  21   a  of the sample insertion unit  21  is an event-driven program, and the control section  21   a  of the sample insertion unit  21  executes the process of Step S 102  when the sensors  212  and  213  detect the sample rack L. 
     In Step S 102 , the control section  21   a  drives the engagement sections  211   a  to move the sample rack L backward until the sample rack reaches the rack output position  214 . Further, the control section drives the protrusion section  215  to output the sample rack L to the pre-processing unit  22  (Step S 102 ). 
     The sample rack L output from the rack output position  214  of the rack insertion unit  21  is introduced into the pre-processing unit  22  in the leftward direction and reaches the barcode reading position. When the sample rack L reaches the barcode reading position, the control section  22   a  of the pre-processing unit  22  controls the barcode reading section  22   b  and reads a rack ID of the sample rack and sample IDs of sample containers T which are held in the sample rack L (Step S 103 ). When the sample rack L reaches the barcode reading position, whether there is a sample container T is detected by the optical sensor of the barcode reading section  22   b , and by the barcode reading section  22   b , a sample barcode of each of the sample containers T is continuously read plural times. When data of the sample IDs each of which is read plural times matches, the reading of the sample barcode is regarded as successful. In this manner, the sample IDs are read from the sample barcodes of all the sample containers T held in the sample rack L. The holding positions in the sample rack L are associated with the sample IDs read from the sample containers which are respectively held in the holding positions, and are stored in the control section  22   a.    
     Next, the control section  22   a  controls the engagement sections  221   a  to transfer the sample rack L to the rack output position  222  on the rack placement section  221  (Step S 104 ) and transmits the stored rack ID, holding positions and sample IDs to the system control apparatus  8  (Step S 105 ). As will be described later, the system control apparatus  8  receiving the rack ID, holding positions and sample IDs inquires the examination information management apparatus  9  of measurement orders and stores the measurement orders in association with the rack ID, holding positions and sample IDs. 
     When the sample rack L reaches the rack output position  222 , the control section  22   a  controls the barcode reader  222   a  to read the rack ID from the rack barcode of the sample rack L (Step S 106 ) and transmits discharge instruction request data including the read rack ID to the system control apparatus  8  (Step S 107 ). When receiving this discharge instruction request data, the system control apparatus  8  searches a measurement order corresponding to the same rack ID from the hard disk, decides a transport destination of the sample rack L on the basis of the search and transmits transport instruction data for transporting the sample rack L to the decided transport destination to the pre-processing unit  22 . The control section  22   a  waits to receive the transport instruction data from the system control apparatus  8  (NO in Step S 108 ). When receiving the transport instruction data (YES in Step S 108 ), the control section controls the protrusion section  225  to output the sample rack L from the rack output position  222  in the leftward direction (Step S 109 ) and ends the process. 
     Every time a new sample rack L is inserted into the sample insertion unit  21 , the processes of the above-described Steps S 101  to S 109  are executed. 
     &lt;Measurement Order Obtaining Operation of System Control Apparatus  8 &gt; 
       FIG. 11  is a flowchart showing the flow of a measurement order obtaining operation of the system control apparatus  8 . The system control apparatus  8  receives the rack ID, holding positions and sample IDs transmitted from the pre-processing unit  22  via the communication interface  81   g  (Step S 111 ). The system control program  84   a  is an event-driven program, and the CPU  81   a  executes the process of Step S 112  when receiving the rack ID, holding positions and sample IDs. 
     In Step S 112 , for all of the received sample IDs, the CPU  81   a  inquires the examination information management apparatus  9  of measurement orders by transmitting measurement order request data including the sample IDs to the examination information management apparatus  9  (Step S 112 ). Next, the CPU  81   a  waits to receive the measurement orders (NO in Step S 113 ). When receiving the measurement orders (YES in Step S 113 ), the CPU stores the measurement orders in the hard disk  81   d  in association with the rack ID, holding positions and sample IDs (Step S 114 ) and ends the process. 
     &lt;First Transport Instruction Operation of System Control Apparatus  8 &gt; 
       FIG. 12  is a flowchart showing the flow of a first transport instruction operation of the system control apparatus  8 . When receiving the discharge instruction request data (rack ID) via the communication interface  81   g  (Step S 121 ), the CPU  81   a  searches a measurement order associated with the received rack ID from the hard disk  81   d  (Step S 122 ). 
     Next, the CPU  81   a  determines whether trouble information has been received (Step S 123 ). The sample transport apparatuses  3   a ,  3   b ,  3   c  and  4  transmit trouble information including information (for example, trouble code) showing the kind of occurring trouble to the system control apparatus  8  when trouble such as breakdown occurs. When determining that the trouble information has not been received (NO in Step S 123 ), the CPU  81   a  specifies the measuring unit  51 ,  52  or  53  which can most rapidly start sample processing and decides the specified unit as the transport destination of the sample rack L (Step S 124 ). 
     The CPU  81   a  manages the transport status of the sample rack L in real time and can determine which one of the measuring units  51 ,  52  and  53  the sample is supplied to most rapidly start sample processing. 
     The CPU  81   a  manages the transport status of the sample rack L by inquiring the respective sample transport apparatuses  3   a ,  3   b  and  3   c  of whether the sample rack L is held in the pre-analysis rack holding section  33 . For example, when the sample rack L is held in the pre-analysis rack holding section  33  of the sample transport apparatus  3   a , the CPU  81   a  determines that the measuring unit  51  cannot receive the sample rack L. That is, in Step S 124 , the CPU  81   a  decides as the transport destination the measuring unit which can measure measurement items included in the measurement order of the sample held in the sample rack L and can receive the sample rack L. 
     When determining that the trouble information has been received (YES in Step S 123 ), the CPU  81   a  determines whether the trouble occurred in the sample transport apparatus  3   a  on the basis of the trouble information (Step S 125 ). When determining that the trouble occurred in the sample transport apparatus  3   a  (YES in Step S 125 ), the CPU  81   a  stops the operation of transporting the sample rack L in the sample rack transport system  100  (Step S 126 ) and waits for elimination of the trouble in the sample transport apparatus  3   a  (Step S 127 ). When determining that the trouble in the sample transport apparatus  3   a  has been eliminated (YES in Step S 127 ), the CPU  81   a  executes the process of Step S 121 . 
     When determining that the trouble did not occur in the sample transport apparatus  3   a , that is, when determining that the trouble occurred in the sample transport apparatus  3   b  or  3   c  (NO in Step S 125 ), the CPU  81   a  determines whether there is the transport unit which can transport the sample rack L (Step S 128 ). Here, the CPU  81   a  determines whether the sample rack L can be transported to the measuring unit which can measure measurement items of the measurement order of the sample held in the sample rack L. 
     Hereinafter, a case in which the trouble occurs in the sample transport apparatus  3   b  will be described as a concrete example. When trouble occurs in the sample transport apparatus  3   b , the sample rack L cannot be transported to the measuring units  52  and  53 . Accordingly, when DIFF or RET is included in the measurement items of the measurement order of the sample held in the sample rack L, the CPU  81   a  determines that the sample rack L cannot be transported. On the other hand, when DIFF or RET is not included in the measurement items of the measurement order of the sample held in the sample rack L, the CPU  81   a  determines that the sample rack L can be transported to the measuring unit  51 . 
     When determining that there is the transport unit which can transport the sample rack L (YES in Step S 128 ), the CPU  81   a  decides as the transport destination the measuring unit which can perform measurement on the sample rack L (Step S 129 ). According to the above-described concrete example, the CPU  81   a  decides the measuring unit  51  as the transport destination of the sample rack L. In addition, when determining that there is no transport unit which can transport the sample rack L (NO in Step S 128 ), the CPU  81   a  decides the sample recovery unit  23  as the transport destination of the sample rack L (Step S 130 ). 
     Next, the CPU  81   a  transmits transport instruction data showing an instruction for transporting the sample rack L to the transport destination to the sample insertion unit  2  and the sample transport apparatuses  3   a ,  3   b  and  3   c  (Step S 130 ) and ends the process. This transport instruction data includes the rack ID of the sample rack L and the holding positions, sample IDs and measurement orders of all the samples which are held in the sample rack L. In the above-described concrete example, the CPU  81   a  transmits the transport instruction data to the sample transport apparatus  3   a  and the sample insertion and recovery apparatus  2 . 
     &lt;First Transport Operation of Sample Transport Apparatuses  3   a ,  3   b  and  3   c&gt;   
       FIG. 13  is a flowchart showing the flow of a first transport operation of the sample transport apparatuses  3   a ,  3   b  and  3   c . When the transport instruction data is received, the control section  22   a  of the pre-processing unit  22  moves the protrusion section  225  leftward to discharge the sample rack L at the rack output position  222  to the rack overtaking transport section  321  of the sample transport apparatus  3   a . Meanwhile, when the transport instruction data is received (Step S 131 ), the control section  32  of the sample transport apparatus  3  determines whether the transport destination of the sample rack L is the measuring unit corresponding to the sample transport apparatus on the basis of the received transport instruction data (Step S 132 ). That is, the control section  32  of the sample transport apparatus  3   a  determines whether the transport destination of the sample rack L is the measuring unit  51 , the control section  32  of the sample transport apparatus  3   b  determines whether the transport destination of the sample rack L is the measuring unit  52 , and the control section  32  of the sample transport apparatus  3   c  determines whether the transport destination of the sample rack L is the measuring unit  53 . 
     When determining that the transport destination is the corresponding measuring unit (YES in Step S 132 ), the control section  32  controls the driving of the transport mechanism  31 , introduces the sample rack L by the rack overtaking transport section  321  and moves the sample rack L positioned at the pre-analysis rack output position  323  to the pre-analysis rack holding section  33  by moving the rack output section  322  forward (Step S 133 ). In addition, the control section  32  transmits the rack ID of the sample rack L and the holding positions, sample IDs and measurement instruction data including measurement orders of all the samples which are held in the sample rack L to the information processing unit  54  (step S 134 ) and ends the process. 
     On the other hand, when determining that the transport destination is not the corresponding measuring unit (NO in Step S 132 ) the control section  32  determines whether the transport destination of the sample rack L is the sample insertion and recovery apparatus  2 , that is, whether the transport destination is the sample recovery unit  23  or  24  or not (Step S 135 ). When determining that the transport destination is the sample insertion and recovery apparatus  2  (the sample recovery unit  23  or  24 ) (YES in Step S 135 ), the control section  32  controls the driving of the transport mechanism  31 , transfers the sample rack L to the rack return transport section  331  by the rack feeding mechanisms  34   c , discharges the sample rack L to the preceding apparatus by the rack return transport section  331  (Step S 136 ) and ends the process. When determining that the transport destination is not the sample insertion and recovery apparatus  2  (the sample recovery unit  23  or  24 ) (NO in Step S 135 ), the control section  32  controls the driving of the transport mechanism  31 , introduces the sample rack L by the rack overtaking transport section  321 , directly discharges the sample rack L to the subsequent apparatus (Step S 137 ) and ends the process. 
     Here, a transport operation by the sample transport apparatus  3   a  when the sample rack L for which the rack recovery unit  23  is the transport destination is discharged by the pre-processing unit  22  will be described. 
     When the sample rack L is not detected by the sensors  34   a  and  34   b  of the post-analysis rack holding section  34 , the sample transport apparatus  3   a  transfers the sample rack L, which is discharged from the pre-processing unit  22 , to the rack overtaking position  321   a  by the rack overtaking transport section  321 , transfers the sample rack to the rack return position  331   a  by the rack feeding mechanisms  34   c  and discharges the sample rack to the sample insertion and recovery apparatus  2  by the rack return transport section  331 . 
     On the other hand, when the sample rack L is detected by the sensors  34   a  and  34   b  of the post-analysis rack holding section  34 , the operations of the sample transport apparatus  3   a  are different in accordance with which one of the detection of the sample rack L by the sensors  34   a  and  34   b  and the reading of the rack ID by the barcode reader  222   a  of the pre-processing unit  22  is more rapidly performed. 
     First, when the detection of the sample rack L by the sensors  34   a  and  34   b  is more rapidly performed, the pre-processing unit  22  waits for the transport of the sample rack L. Meanwhile, the sample transport apparatus  3   a  transfers the sample rack L in the post-analysis rack holding section  34  to the rack overtaking position  321   a  or the rack return position  331   a  by the rack feeding mechanisms  34   c  and transports the sample rack L by the rack overtaking transport section  321  or the rack return transport section  331 . Then, the pre-processing unit  22  discharges the sample rack L, and the sample transport apparatus  3  transfers the discharged sample rack L to the rack overtaking position  321   a  by the rack overtaking transport section  321 , transfers the sample rack to the rack return position  331   a  by the rack feeding mechanisms  34   c  and transports the sample rack to the sample insertion and recovery apparatus  2  by the rack return transport section  331 . 
     Next, when the reading of the rack ID by the barcode reader  222   a  of the pre-processing unit  22  is more rapidly performed, the sample transport apparatus  3   a  causes the sample rack L transferred to the post-analysis rack holding section  34  to wait in the post-analysis rack holding section  34 , transfers the sample rack L discharged from the sample insertion and recovery apparatus  2  to the rack overtaking position  321   a  by the rack overtaking transport section  321 , transfers the sample rack to the rack return position  331   a  by the rack feeding mechanisms  34   c , and transports the sample rack to the sample insertion and recovery apparatus  2  by the rack return transport section  331 . Then, the sample transport apparatus  3   a  transfers the sample rack L in the post-analysis rack holding section  34  to the rack return position  331   a  by the rack feeding mechanisms  34   c , transfers the sample rack to the rack overtaking position  321   a  or the rack return position  331   a  by the rack feeding mechanisms  34   c  and transports the sample rack L by the rack overtaking transport section  321  or the rack return transport section  331 . 
       FIG. 14  is a flowchart showing the flow of a transport destination chance process of the system control apparatus  8 . This process is a process for changing the transport destination of the sample rack L which is inserted into the sample transport apparatus when trouble occurs. 
     In the hard disk  81   d  of the system control apparatus  8 , the transport destination of the sample rack L which is inserted into the sample transport apparatus is stored. When receiving trouble information from the sample transport apparatus (Step S 141 ), the CPU  81   a  searches the transport destination of the sample rack L from the hard disk  81   d  (S 142 ). Next, on the basis of the search result in Step S 142 , the CPU  81   a  determines whether the inserted sample rack L can be transported to the transport destination when trouble occurs (Step S 143 ). 
     For example, when trouble occurs in the sample transport apparatus  3   b , the sample rack L can be transported to the measuring unit  51 , but cannot be transported to the measuring units  52  and  53 . 
     Accordingly, when trouble occurs in the sample transport apparatus  3   b , the CPU  81   a  determines that the sample rack L can be transported to the transport destination when the transport destination of the sample rack L is the measuring unit  51 . When the transport destination of the sample rack L is the measuring unit  52  or  53 , the CPU  81   a  determines that the sample rack L cannot be transported to the transport destination. 
     When determining that the sample rack L cannot be transported to the transport destination (YES in Step S 143 ), the CPU  81   a  changes the transport destination of the sample rack L to the sample recovery unit  23  (Step S 144 ), transmits transport instruction data to the sample insertion and recovery apparatus  2  and the sample transport apparatuses  3   a ,  3   b  and  3   c  (Step S 145 ) and ends the process. In addition, the CPU  81   a  ends the process also when determining that the sample rack L can be transported to the transport destination (NO in Step S 143 ). 
     &lt;Rack Transport Control Operation of Blood Cell Analysis Apparatus  5 &gt; 
       FIG. 15  is a flowchart showing the flow of a rack transport control operation of the blood cell analysis apparatus  5 . The CPU  541   a  of the information processing unit  54  of the blood cell analysis apparatus  5  detects the sample rack L in the pre-analysis rack holding section  33  by the rack sensors provided in the sample transport apparatus  3   a ,  3   b  and  3   c  (Step S 151 ). When receiving measurement instruction data from the sample transport apparatus  3   a ,  3   b  and  3   c  (Step S 152 ), the CPU executes the process of Step S 153 . 
     In Step S 153 , the CPU  541   a  moves the rack feeding sections  33   b  backward to transfer the sample rack L to the rack transport section  35 . Next, the CPU  541   a  controls the driving of the rack transport section  35  and transports the sample rack L so as to position the sample container T at the sample supply position (Step S 154 ). 
     In a sample analysis operation to be described later, the sample container T which is positioned at the sample supply position is removed from the sample rack L and taken into the measuring unit. The sample is suctioned from the sample container T and is analyzed. When the suction of the sample in the measuring unit is completed, the sample container T is returned to the sample rack L. In addition, the CPU  541   a  determines whether all the sample containers T in the sample rack L have been taken (Step S 155 ). When determining that all the sample containers T in the sample rack L have not been taken (NO in Step S 155 ), that is, when there is a sample container T which has not been taken, the CPU  541   a  controls the driving of the rack transport section  35  to transport the sample rack L so that the holding position at which the next sample container T is detected is positioned at the sample supply position (Step S 156 ) and returns the process to Step S 155 . 
     In Step S 155 , when determining that all the sample containers T which are held in the sample rack L have been taken (YES in Step S 155 ), the CPU  541   a  controls the driving of the rack transport section  35  to transport the sample rack L up to the post-analysis rack output position  391  and further controls the driving of the rack output section  39  to transfer the sample rack L to the post-analysis rack holding section  34  (Step S 157 ), transmits measurement completion notification data including the rack ID of the sample rack L to the corresponding sample transport apparatus (Step S 158 ) and ends the process. 
     &lt;Sample Analysis Operation of Blood Cell Analysis Apparatus  5 &gt; 
       FIG. 16  is a flowchart showing the flow of a sample analysis operation of the blood cell analysis apparatus  5 . The above-described rack transport control operation of the blood cell analysis apparatus  5  and the present sample analysis operation are executed in parallel by a multitasking process. The CPU  541   a  executes the process of Step S 172  when the sample container T which is held in the sample rack L reaches the sample supply position (Step S 171 ). 
     In Step S 172 , the CPU  541   a  removes the sample container T positioned at the sample supply position from the sample rack L and takes the sample container into the measuring unit by controlling the sample container transport section  515  of the measuring unit (Step S 172 ). Further, the CPU  541   a  oscillates the sample container T by controlling the hand section  515   a  to stir the sample therein, and then controls the sample container transport section  515  to transport the sample container T to the barcode reading position  516  and reads the sample barcode of the sample container T by the barcode reading section  516 , thereby obtaining the sample ID (Step S 173 ). 
     Then, the CPU  541   a  measures the sample by using a measurement order included in the measurement instruction data (step S 174 ). 
     The CPU  541   a  suctions the sample in an amount necessary for measurement from the sample container T, prepares a measurement specimen, starts the measurement of the sample, and then controls the sample container transport section  515  of the measuring unit to return the sample container T to the sample rack L from the measuring unit (Step S 175 ). Then, in the above-described rack transport control operation, the rack transport section  35  is controlled and the sample rack L is thus transported in the X 1  direction. The CPU  541   a  processes measurement data which is obtained by measuring the sample and obtains a sample analysis result (Step S 176 ). Next, the CPU  541   a  transmits the obtained analysis result to the system control apparatus  8  and the examination information management apparatus  9  (Step S 177 ) and ends the process. 
     &lt;Second Transport Instruction Operation of System Control Apparatus  8 &gt; 
       FIG. 17  is a flowchart showing the flow of a second transport instruction operation of the system control apparatus  8 . As will be described later, the sample rack L, in which the samples were measured and which was transferred to the post-analysis rack holding section  34  from the post-analysis rack output position  391 , is detected by the sensors  34   a  and  34   b . In addition, the measurement completion notification data transmitted from the information processing unit  54  is received by the corresponding sample transport apparatus. At this time, the sample transport apparatus transmits transport instruction request data including the rack ID of the sample rack L to the system control apparatus  8 . When receiving the transport instruction request data (Step S 191 ), the CPU  81   a  of the system control apparatus  8  searches the analysis result corresponding to the rack ID which is included in the transport instruction request data from the hard disk  81   d  (Step S 192 ). 
     The CPU  81   a  determines whether a sample requiring remeasurement or a microscopic test is included in the samples held in the sample rack L (Step S 193 ). When determining that a sample requiring remeasurement or a microscopic test is not included (NO in Step S 193 ), the CPU  81   a  decides the sample recovery unit  24  as the transport destination of the sample rack L (Step S 194 ). When determining that a sample requiring remeasurement or a microscopic test is included (YES in Step S 193 ), the CPU  81   a  determines whether trouble information is received (Step S 195 ). When determining that the trouble information is not received (NO in Step S 195 ), the CPU  81   a  advances the process to Step S 198 . 
     When determining that the trouble information is received (YES in Step S 195 ), the CPU  81   a  determines whether the sample rack can be transported to the smear preparation apparatus  6  or the measuring unit capable of performing remeasurement of the sample in the sample rack L (Step S 196 ). In greater detail, when trouble occurs in the sample transport apparatus  3   b , measurement is performed in the sample rack L by the measuring unit  51  and a sample requiring remeasurement by the measuring unit  52  or  53  is included, the CPU  81   a  determines that the sample rack L cannot be transported to any measuring unit. 
     When determining that the sample rack L cannot be transported to the smear preparation apparatus  6  or the measuring unit capable of performing remeasurement (NO in Step S 196 ), the CPU  81   a  decides the sample recovery unit  23  as the transport destination of the sample rack L (Step S 197 ). When determining that the sample rack L can be transported to the smear preparation apparatus  6  or the measuring unit capable of performing remeasurement (YES in Step S 196 ), the CPU  81   a  decides the smear preparation apparatus  6  or the measuring unit as the transport destination (Step S 198 ). 
     After decision of the transport destination of the sample rack L as described above, the CPU  81   a  transmits transport instruction data showing an instruction for transporting the sample rack L to the decided transport destination to the sample insertion and recovery apparatus  2  and the sample transport apparatuses  3   a ,  3   b  and  3   c  (Step S 199 ) and ends the process. 
     &lt;Second Transport Operation of Sample Transport Apparatuses  3   a ,  3   b  and  3   c&gt;   
       FIG. 18  is a flowchart showing the flow of a second transport operation of the sample transport apparatuses  3   a ,  3   b  and  3   c . As described above, when the sample rack L is transferred to the post-analysis rack holding section  34  by the rack output section  39 , the sample rack L is detected by the rack sensor (Step S 211 ). In addition, when the sample rack L is transferred to the post-analysis rack holding section  34  by the rack output section  39 , the measurement completion notification data which is transmitted from the information processing unit  54  is received (Step S 212 ). The control section  32  detects the sample rack L in the post-analysis rack holding section  34  by the rack sensors. When receiving the measurement completion notification data from the information processing unit  54 , the control section executes the process of Step S 213 . 
     In Step S 213 , the control section  32  transmits transport instruction request data including the rack ID of the sample rack L to the system control apparatus  8  (Step S 213 ). As described above, when receiving the transport instruction request data, the system control apparatus  8  decides the transport destination of the sample rack L and transmits transport instruction data for transporting the sample rack L to the transport destination to the sample transport apparatuses  3   a ,  3   b  and  3   c . The control section  32  waits to receive the transport instruction data (NO in Step S 214 ). When receiving the transport instruction data (YES in Step S 214 ), the control section determines whether the transport destination which is shown in the transport instruction data is the subsequent measuring unit or the smear preparation apparatus  6  or not (Step S 215 ). When the transport destination which is shown in the transport instruction data is the subsequent measuring unit or the smear preparation apparatus  6  (YES in Step S 215 ), the control section  32  controls the driving of the transport mechanism  31 , transfers the sample rack L to the rack overtaking transport section  321  by the rack feeding sections  33   b , and then discharges the sample rack L to the transport direction downstream side by the rack overtaking transport section  321  (Step S 216 ) and ends the process. 
     In addition, when determining that the transport destination which is shown in the transport instruction data is not the subsequent measuring unit or the smear preparation apparatus  6 , that is, when determining that the transport destination is the sample recovery unit  23  or  24  (NO in Step S 215 ), the control section  32  controls the driving of the transport mechanism  31 , transfers the sample rack L to the rack return transport section  331  by the rack feeding sections  33   b , discharges the sample rack L to the preceding apparatus by the rack return transport section  331  (Step S 217 ) and ends the process. 
     When the sample rack L is discharged to the apparatus on the transport direction upstream side from the rack return transport section  331  of the sample transport apparatus  3   b ,  3   c  or  4 , the apparatus introducing the sample rack L transports the sample rack L to the transport direction upstream side by the rack return transport section  331  and discharges the sample rack L to the apparatus on the upstream side. 
     &lt;Rack Sorting and Recovery Operation of Sample Insertion and Recovery Apparatus  2 &gt; 
       FIG. 19  is a flowchart showing the flow of a rack sorting and recovery operation of the sample insertion and recovery apparatus  2 . This rack sorting and recovery operation is an operation which is executed by the respective control sections of the sample insertion unit  21  and the sample recovery units  23  and  24  and is started by receiving the above-described transport instruction data from the system control apparatus  8  in Step S 221 . Hereinafter, the rack sorting and recovery operation will be described which is executed by the control section  23   a  of the sample recovery unit  23 . 
     When receiving the above-described transport instruction data from the system control apparatus  8  (Step S 221 ), the control section  23   a  of the sample recovery unit  23  determines whether the transport destination of the sample rack L which is introduced into the second transport line  237  via the return line, the transport line  223  of the pre-processing unit  22  and the second transport line  217  is the sample recovery unit  23  on the basis of the transport instruction data (Step S 222 ). When determining that the transport destination is the sample recovery unit  23  (YES in Step S 222 ), the control section  23   a  transfers the sample rack L introduced into the second transport line  237  to the rack placement section  231  by driving the rack transfer section  238  (Step S 223 ) and ends the process. In this manner, the sample rack L is recovered by the sample recovery unit  23 . 
     When determining that the transport destination is not the sample recovery unit  23  (NO in Step S 222 ), the control section  23   a  transports the sample rack L to the transport direction upstream side (X 2  direction) by driving the second transport line  237  and discharges the sample rack L to the second transport line  247  toward the sample recovery unit  24  (Step S 224 ). 
     As described above, in the sample rack transport system  100  according to this embodiment, even when trouble occurs in one of the plurality of sample transport apparatuses  3   b ,  3   c  and  4 , excluding the sample transport apparatus  3   a  on the most upstream side, the sample rack transport operation is not stopped in the entire system. Therefore, according to the sample rack transport system  100  according to this embodiment, sample measurement efficiency can be improved even when trouble occurs. 
     When trouble is eliminated, a user is required to manually insert the sample rack L, in which necessary measurement has not yet been completed, into the sample insertion unit  21 . Here, in the sample rack transport system  100  according to this embodiment, the sample rack L is recovered by the sample recovery unit  23  adjacent to the sample insertion unit  21 . Accordingly, in the sample rack transport system  100  according to this embodiment, it is easy for the user to reinsert the sample rack L. 
     (Second Embodiment) 
     This embodiment is almost the same as the first embodiment. However, the configuration of a sample insertion and recovery apparatus  2  and the recovery destination of a sample rack L are different. 
       FIG. 20  is a plan view of the sample insertion and recovery apparatus  2  according to this embodiment. As shown in  FIG. 20 , the sample insertion and recovery apparatus  2  according to this embodiment includes a sample insertion unit  21 , a pre-processing unit  22  and a recovery unit  23 . In this embodiment, a sample rack L in which necessary measurement has not yet been completed is transported to the sample insertion unit  21  and a sample rack L in which necessary measurement has been completed is transported to the recovery unit  23 . 
     When trouble is eliminated, a system control apparatus  8  transmits a transport instruction to the sample insertion and recovery apparatus  2 . Since the subsequent processes are the same as the processes of Steps S 103  to S 109  in the sample discharge operation of the sample insertion and recovery apparatus  2  in the first embodiment 1, the description thereof will be omitted. 
     In a sample rack transport system  100  according to this embodiment, a sample rack L in which necessary measurement has not yet been completed can be automatically reinserted to the sample rack transport system  100 . Accordingly, it is possible to save the effort of reinsertion of the sample rack L into the sample rack transport system  100  by a user. 
     (Other Embodiments) 
     In the above-described embodiments, the computer  8   a  of the system control apparatus  8  decides the recovery destination of a sample rack L and the control section of the sample recovery unit controls the operations of the rack transfer section and the second transport line on the basis of the decided recovery destination, and therefore, the sorting and recovery of the sample rack L is performed. However, the invention is not limited thereto. The sorting and recovery of the sample rack L may be performed by executing the process of deciding the recovery destination of the sample rack L and the process of controlling the operations of the rack transfer section and the second transport line with a single computer (control section). 
     In the above-described embodiments, the configuration has been described in which the sample processing system  1  includes the blood cell analysis apparatus  5  which classifies blood cells included in a sample and counts the number of blood cells for each blood cell kind, but the invention is not limited thereto. The sample processing system may include a sample analysis apparatus other than the blood cell analysis apparatus, such as an immunological analysis apparatus, a blood coagulation measurement apparatus, a biochemical analysis apparatus and a urine analysis apparatus, and transport a blood sample or an urine sample to a measuring unit of the sample analysis apparatus. 
     In the above-described embodiments, the configuration has been described in which the blood cell analysis apparatus  5  includes the three measuring units  51 ,  52  and  53  and the information processing unit  54 , but the invention is not limited thereto. One or plural measuring units may be provided, and the measuring unit and the information processing unit may be formed integrally with each other. In addition, a configuration may be provided in which the mechanisms in the measuring units  51 ,  52  and  53  are not controlled by the information processing unit  54 , but each of the measuring units has a control section formed of a CPU, a memory and the like so as to control the measuring units by the control sections, measurement data which is obtained by the respective measuring units is processed by the information processing unit and thus a sample analysis result is generated. 
     In the above-described embodiments, the configuration has been described in which all the processes of the computer program  84   a  are executed by the single computer  8   a , but the invention is not limited thereto. A distribution system may be provided which distributes the same processes as the above-described computer program  84   a  to plural devices (computers) and executes the processes. 
     In the above-described embodiments, as a concrete example, the case has been described in which trouble occurs in the sample transport apparatus  3   b . However, of course, the sample rack transport system  100  according to the above-described embodiment executes the same process even when trouble occurs in the sample transport apparatus  3   c.    
     In a case in which trouble occurs in the sample transport apparatus  3   c  when the sample recovery unit  23  is decided as the transport destination of a sample rack L in the first transport instruction of the system control apparatus  8 , the sample rack L may be discharged to the sample transport apparatus  3   a  from the pre-processing unit  22  and the sample transport apparatus  3   a  may transfer the sample rack L output from the sample insertion and recovery apparatus  2  to the rack overtaking position  321   a , transfer the sample rack to the rack return position  331   a  by the rack feeding mechanisms  34   c  and discharge the sample rack to the sample insertion and recovery apparatus  2  by the rack transport section  35 . 
     In the above-described embodiments, when DIFF is included in measurement items of the measurement order of a sample held in a sample rack L and trouble occurs in the sample transport apparatus  3   b , the sample recovery unit  23  is decided as the transport destination. However, the invention is not limited thereto. For example, when CBC and DIFF are included in measurement items of the measurement order of a sample held in a sample rack L, the measuring unit  51  may be decided as the transport destination of the sample rack L. In this case, only CBC may be measured in the measuring unit  51  and then the sample recovery unit  23  may be decided as the transport destination of the sample rack L by the system control apparatus  8 . In this manner, the measurement items which can be measured in the measuring unit are measured and thus sample processing efficiency can be improved. The same is also applied to a case in which trouble occurs in the sample transport apparatus  3   c  when RET and CBC or DIFF are included in measurement items of the measurement order of a sample held in a sample rack L. 
     The trouble in the above-described embodiments is a severe problem which requires repair by a service man, but the invention is not limited thereto. The trouble may be a small problem such as a mistake in the transport of a sample rack. 
     In the above-described embodiments, the sample transport apparatuses  3   a ,  3   b  and  3   c  includes the rack overtaking transport section  321  which transports a sample rack L by driving the transport belt in the transport downstream direction with a stepping motor and the rack return transport section  331  which transports a sample rack L by driving the transport belt in the transport upstream direction with the stepping motor. However, the invention is not limited thereto. For example, a configuration may be provided in which the sample transport apparatuses  3   a ,  3   b ,  3   c  and  4  have a transport belt and a stepping motor driving the transport belt to transport a sample rack by a single transport section which can switch the driving direction of the transport belt into the transport downstream direction and the transport upstream direction. In this case, a sample rack L which is determined that there is a measuring unit to which the sample rack can be transported by the system control apparatus  8  is discharged to the sample transport apparatus  3   a  by the pre-processing unit  22 , is transported to the pre-analysis rack output position  323  by the transport belt which is driven in the transport downstream direction, and is fed to the pre-analysis rack holding section  33  by the rack feeding sections  33   b . When the measurement is completed, the sample rack L is fed to the rack overtaking position  321   a  from the post-analysis rack holding section  34  by the rack feeding mechanisms  34   c  and is transported to the rack recovery unit  24  by the transport belt which is driven in the transport upstream direction. On the other hand, a sample rack L which is determined that there is no measuring unit to which the sample rack can be transported by the system control apparatus  8  is discharged to the sample transport apparatus  3   a  by the pre-processing unit  22  first, and is transported to the rack recovery section  23  by the transport belt which is driven in the transport upstream direction. Here, the sample rack L which is determined that there is no measuring unit to which the sample rack can be transported by the system control apparatus  8  may be directly transported to the rack recovery section  23  from the pre-processing unit  22 . 
     In the above-described embodiments, each of the sample transport apparatuses  3   a ,  3   b  and  3   c  includes both of the rack overtaking transport section  321  transporting a rack to the downstream and the rack return transport section  331  transporting a rack to the upstream. However, the invention is not limited thereto. For example, each of the sample transport apparatuses  3   a ,  3   b  and  3   c  may include a unit which has a mechanism transporting a rack to the upstream and a unit which has a mechanism transporting a rack to the downstream. That is, a configuration may be provided in which each of the sample transport apparatuses  3   a ,  3   b  and  3   c  includes a first sample transport unit having at least the rack overtaking transport section  321  and a second sample transport unit having at least the rack return transport section  331 . 
     In the above-described embodiments, when determining that the inserted sample rack L cannot be transported to the transport destination in Step S 143 , the CPU  81   a  changes the transport destination of the sample rack L to the sample recovery unit  23 , but the invention is not limited thereto. In the invention, the CPU  81   a  may change the transport destination of the inserted sample rack L to another measuring unit which can perform measurement on the sample rack L. For example, when the measuring unit  53  is decided as the transport destination before the insertion of the sample rack L into the sample transport apparatus and trouble occurs in the sample transport apparatus  3   c  corresponding to the measuring unit  53  after insertion of the sample rack L, the CPU  81   a  may change the transport destination of the sample rack L, for which the measuring unit  53  is decided as the transport destination, to either of the measuring units  51  and  52  which can measure the sample in the sample rack L.