Abstract:
A sample processing system is configured for analyzing, preprocessing, or carrying out other operations for a biological sample such as blood or urea. With the sample processing system, it is possible to store samples to be stored in a thermally insulated state or specimens required for accuracy control in the thermally insulated state for preventing evaporation or denaturing of the samples and specimens. Also it is possible to carry in or out the samples, rack by rack, according to necessity. Further, the sample processing system is provided with a buffer unit in a cold container having a capability for cold storage and also by accessing a sample rack at random for carrying in or out a rack with a transfer mechanism provided outside of the cold container.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 12/121,006, filed May 15, 2008 and claiming priority to Japanese Utility Model Application No. 2007-003516, filed May 16, 2007, the disclosures of which are expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a sample handling system for storing and refrigerating a sample such as blood or urine sampled for checking and also for delivering a specimen required for accuracy control. 
         [0004]    2. Description of the Related Art 
         [0005]    In the conventional sample handling system, a large-size cold container capable of accommodating therein 1000 or more samples is generally used for storing samples required for accuracy control in the thermally insulated state. The samples are stored and taken out with the unit of a test tube by an XYZ mechanism and a hand mechanism provided in the cold container. A known transfer path buffer used has been described, for instance, in JP-A-2005-274289. 
       SUMMARY OF THE INVENTION 
       [0006]    Because a large-size cold container is used for storing all samples in the refrigerated state, it takes much time to store or take out the samples. Therefore, it takes time unnecessarily to take out samples to be rechecked, and a time delay occurs in reporting a result of analysis or the like. Furthermore, a specimen required for accuracy control is manually input at a prespecified time interval. An object of the present invention is to refrigerate samples to be stored in the thermally insulated state or specimens required for accuracy control with the unit of a transfer rack or transfer racks to prevent evaporation or denaturing of the samples or specimens and also to make it possible for the samples to be carried in or out with a rack according to the necessity. 
         [0007]    A configuration according to the present invention can be realized by installing a cold container having a thermally insulating function in a buffer unit in a sample handling and accessing sample racks at random with a transfer mechanism installed outside the cold container to carry in our out the racks. Furthermore the configuration according to the present invention can be realized by employing a small-size cold container using a Peltier unit or the like to accommodate a small number of racks in the thermally insulated state therein. 
         [0008]    As described above, when a cold container is installed in a buffer unit, it is possible to refrigerate and store samples required for thermal insulation or specimens required for accuracy control, to prevent evaporation or denaturing of the samples or specimens, and to supply the samples or specimens rack by rack according to the necessity. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a view illustrating an example of a system configuration of a buffer unit with a cold container; 
           [0010]      FIG. 2  is a view illustrating the buffer unit with a cold container; 
           [0011]      FIG. 3  is a view illustrating the cold container; 
           [0012]      FIG. 4  is a view illustrating an example of a sample container mounted in the cold container; 
           [0013]      FIG. 5  is a view illustrating an example of a rack to be carried in or out from the cold container; 
           [0014]      FIG. 6  is a view illustrating an example of a rack to be carried in or out from the cold container; 
           [0015]      FIG. 7  is a view illustrating an example of a display screen in an operating section; 
           [0016]      FIG. 8  is a view illustrating a temperature control flow; 
           [0017]      FIG. 9  is a view illustrating a flow of control for opening or closing a door; 
           [0018]      FIG. 10  is a view illustrating an evaporation control flow; 
           [0019]      FIG. 11  is a view illustrating an example of a structure inside the cold container and of a position at which a cooler is mounted; 
           [0020]      FIG. 12  is a view illustrating an example of a structure inside the cold container and of a position at which a cooler is mounted; 
           [0021]      FIG. 13  is a view illustrating a structure and operations of a cold container rack transfer mechanism; 
           [0022]      FIG. 14  is a view illustrating a structure and operations of the cold container rack transfer mechanism; 
           [0023]      FIG. 15  is a view illustrating a structure and operations of the cold container rack transfer mechanism; and 
           [0024]      FIG. 16  is a view illustrating a view illustrating a structure and operations of the cold container rack transfer mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    An embodiment of a system configuration according to the present invention is described below with reference to the example shown in  FIG. 1 . 
         [0026]      FIG. 1  is a view schematically showing one example of the system configuration in which a buffer unit  1  is used. The system includes an input unit  2 , a transfer section  3 , and a storage unit  4  as a core of the system. The system also includes a processing unit  5  and a buffer unit  1  with a cold container provided between the input unit  2  and the processing unit  5 . The system can communicate with an operating section  6  via a communication line. The processing unit  5  and the buffer unit  1  with a cold container can be extended if the transfer sections are increased. 
         [0027]      FIG. 2  is a view illustrating a configuration of the buffer unit  1  with a cold container. The buffer unit  1  with a cold container includes a buffer section  10  and a storage section. The buffer section  10  mounts a general sample rack. The cold storage section  11  stores samples to be stored in the thermally insulated state and specimens required for accuracy control. The buffer section  10  and the cold storage section  11  can mount a plurality of racks  12  whose positions numbers are previously set thereon. The rack  12  mounted on the buffer section  11  or on the cold storage section  11  can be accessed at random with a handling unit  13  provided on a transfer mechanism  14  regardless of its position, so that it is possible to take out only a necessary one among the racks  12 . Examples on random access are displayed on a screen  50  of an operating section  6  as shown in  FIG. 7 . Presence or absence of a rack, a cold storage time, and accessibility for each position is shown on the screen  50 . Because there is not a rack at position C, access to position C is inhibited. Although the rack  12  is present at position B, because the cold storage time is shorter than a prespecified period of time, access to the position B is inhibited. The cold storage time is required to set a sample or a reagent at a constant temperature for appropriate analysis accuracy, being set to any value according to the necessity (or to zero, if not required). The accessible positions are positions A, D, and E in this example. In this situation, the rack  12  at position D is selected as a target for random access by the operating section  6  because the cold storage time at the position is longer than the reference time. The rack  12  at position D is held by the handling unit  13 , and is transferred in the state by the transfer mechanism  14  through the transfer section  15 , and is supplied by the main transfer section  16  to the processing unit  5  which is provided in the downstream side. Furthermore, another rack  12  transferred from an upstream unit by the main transfer section  16  is held by the handling unit  13 , and a position number at which the rack  12  is to be stored is instructed by the operating section  6  via a communication line. For instance, the rack  12  can be stored at position C in the cold storage section  11 , and thus it is possible to control and manage the rack  12  independently from that at position D. 
         [0028]    As described above, because random access is possible, access to a target sample can be performed quickly. As a result, because the time it takes to open or close a door of the cold container can be shortened, a temperature change within the cold container can be suppressed. In addition, such parameters as a temperature within the cold container or a cumulative time can be displayed on the screen  50 . Furthermore, a graph of temperature change can be displayed thereon. 
         [0029]      FIG. 3  is a view illustrating an example of an appearance of a cold container  30 . A cooler  21  is mounted on a side face  20  of the cold container so that a sample and a specimen in a sample container  22  mounted on the rack  12  placed in the cold container are stored in the thermally insulated state to prevent evaporation or denaturing of the sample or the specimen. For instance, a Peltier unit is used for the cooler  21 , and such a material as a coolant or cooling water is not used for it. Temperature inside the cold container  30  is measured with a temperature sensor  101  while the peripheral temperature is measured by a peripheral temperature sensor  102  so that they may be controlled. Such a device as a thermocouple or a thermistor is used for the temperature sensor  101  and the peripheral temperature sensor  102 . 
         [0030]    The control is performed as described below.  FIG. 8  is a flow chart for temperature control within a cold container. For temperature control within the cold container  30 , a Peltier unit is used as the cooler  21 , and when the Peltier unit is turned ON, the temperature within the cold container  30  drops. Temperature within the cold container  30  is measured by the temperature sensor  101  at a prespecified sampling time. When a temperature f within the cold container is compared to a preset temperature F and it is determined that the temperature f is not more than the present temperature F, the Peltier unit is turned OFF. When the temperature f within the cold container is higher than the preset temperature F, a period of cold storage time m elapsed after input of the sample is measured. The cold storage time m is measured with a timer such as a microprocessor not shown in the figure. When the cold storage time m is compared to a preset time M and it is determined that the storage time m is not longer than the preset time M, the Peltier unit is turned ON. IF the Peltier unit has been ON, the unit is as it is. When the cold storage time m is longer than the preset time M, an alarm  51  is output because the preset temperature F is not reached. The alarm  51  can be recognized when displayed on the operating section  6 , for instance, via a communication line. The sampling time, the preset time F within the cold container, and the preset time M for cold storage can freely be set with the operating section  6  according to the necessity, and they are written in a memory area of a microprocessor not shown, for instance, via a communication line. The memory must be involatile or electrically backed up with any power source. 
         [0031]      FIG. 9  is a flow chart for controlling opening and closing operations of a door of the cold container. When the door of the cold container is opened and closed n times, temperature change occurs in the cold container because the peripheral air is introduced therein. The system according to the present invention is intended to prevent degradation of specimens stored in the container based on this temperature change. When the door of the cold container is opened and closed n times, namely when the door is opened and closed prespecified times N or more, for instance, within one hour, an alarm  52  is output. This alarm  52  can be recognized, for instance, via a communication line, on the operating section  6 . The prespecified times N can freely be set at the operating section  6  according to the necessity, and is written in a memory area of a microprocessor not shown via a communication line or the like and cleared to zero by a one-hour timer. 
         [0032]      FIG. 10  is a flow chart of evaporation control for a sample. A cold storage time t 1  of a sample stored in the thermally insulated state in the cold container is measured and compared to a preset time T 1 . It is determined that a sample in which the time t 1  is not less than the time T 1  can be used, while a sample in which the time T 1  is not reached cannot be used yet, and cold storage of the sample is continued. A sample determined as available is carried out from the cold container according to an instruction from the operating section  6 , and is processed for prespecified items in the processing unit  5 . After the processing is complete, the sample is again returned to the buffer section and is carried into the cold container to be stored in the thermally insulated state. To control an amount of evaporation, a time t 2  elapsed from the time point when the sample is carried out from the cold container until the time point when the sample is again carried into the cold container is measured and compared to a preset time T 2 . When the time t 2  is not less than the preset time T 2 , an alarm  53  is output. This alarm  53  can be recognized when the alarm  53  is displayed on the operating section  6 , for instance, via a communication line. The preset time T 1  and the preset time T 2  are written in a memory area of a microprocessor from the operating section  6  via the communication line or the like. The samples stored in the thermally insulated state in the cold container are shown in the operating section  6  as a table as shown in  FIG. 7 . As described above, output of the preset parameters and alarms is controlled by the operating section  6 . The samples for which the alarms  51 ,  52 , and  53  have been issued are carried out onto the storage unit  4  and are managed in the operating section  6 . 
         [0033]    The cooler  21  can be mounted also on an upper surface  23  of the control container. The cooler  21  is mounted on a face of the cold container  30  to cool inside of the container.  FIG. 11  is a view showing an example in which the cooler  21  is mounted on an upper surface of the container  30 , while  FIG. 12  is a view showing an example in which the cooler  21  is amounted on a side face of the container  30 . As shown in  FIG. 3 , the cold container is cooled from one face thereof, and therefore temperature in the upper portion of the cold container is not equal to that in the lower portion. To make the temperature within the cold container  30  uniform, a convection space  202  for circulating air therein is provided under a cold storage space  201  in which a sample rack is accommodated as shown in  FIG. 11  and  FIG. 12 . The convection space  202  allows air inside the space to be naturally circulated, and a difference between temperature in the upper portion and that in the lower portion becomes smaller. The cold storage space  201  and the convection space  202  are configured so that convection of the air is performed through a plurality of ventilation holes  203 . The ventilation holes  203  are provided so that convection of air therethrough will occur, and may have a wire mesh. The convection space  202  may be a height of 2 to 3 cm so long as air circulates. 
         [0034]      FIG. 4  is a view showing a sample container  22  mounted on the rack  12  placed in the cold container. The rack  12  carries thereon the sample container  22  and the sample container  24  which have a sample  25  put therein respectively. A sample container a 24  may be mounted on the sample container  22 . 
         [0035]      FIG. 5  is a cross-sectional view illustrating how to transfer the rack  12  placed in the cold container. A top surface of the cold container  30  is automatically opened so that the rack  12  in the cold container  30  can be accessed. Operations for opening and closing the door of the cold container are performed in synchronism to operations of the XYZ mechanism so that the operations can be performed within as short a period of time as possible to ensure cold storage. The rack  12  placed in the cold container  30  is grasped and held by the handing unit  13  mounted on a side face of the transfer mechanism  14 . In the state, the rack  12  is raised and taken out from the cold container  30 , followed by the next processing. When the rack  12  is to be stored in the cold container, the operations are performed in the reverse sequence. While the handling unit  13  grasps and holds the rack  12  to be transferred, it does not contact the sample container  22 . 
         [0036]      FIG. 6  is a cross-sectional view illustrating how to transfer the rack  12  placed in the cold container  30 . A side face of the cold container  30  is automatically opened so that the rack  12  placed in the cold container  30  can be accessed. To reduce friction between the rack  12  and the cold container  30  during the transfer, a roller  40  may be provided on a bottom surface of the rack  12  so that the operations for carrying in and out the rack  12  can be performed smoothly. 
         [0037]    A rack transfer mechanism  360  includes a bucket  361  capable of holding one rack and moving in the Y-axial direction, an X-axial mechanism  362  for moving together with the bucket in the Y-axial direction to transfer a rack in the bucket in the X-axial direction, and a carriage  363  mounted to the X-axial mechanism  362  for up and down movement. 
         [0038]    The rack transfer mechanism is described in detail below with reference to  FIG. 13  to  FIG. 16 , and the description is made for an example in which a sample rack mounted in the bucket  361  is transferred to the buffer section  302  inside the cold container  30 . 
         [0039]    At first, the rack transfer mechanism  360  drives a Y drive motor  364  to move the bucket  361  to a stand-by position at which a rack in the cold container  30  is carried in or out. At the same time, the rack transfer mechanism  360  drives an X drive motor  365  to move the carriage  363  mounted to the X-axial mechanism  362  to a position under the sample rack mounted in the bucket  361  ( FIG. 13 ). Then, the rack transfer mechanism  360  drives a door drive motor  368  to move a door  31  of the cold container in the lateral direction to open the door. At the same time, the rack transfer mechanism  360  drives a Z drive motor  366  to raise the carriage  363  amounted to the X-axial mechanism  362  so that the carriage  363  can be set in a groove provided on a bottom surface of the sample rack ( FIG. 14 ). 
         [0040]    Slits  367  are provided in the bucket  361  as well as on a sample rack transfer surface of the rack buffer section  302  in the cold container so that the carriage  363  can move in the X-axial direction in the elevated state. 
         [0041]    Then, in the state where the carriage  363  is set in the groove provided on the bottom surface of the sample rack, the rack transfer mechanism  360  drives the X drive motor  365  to transfer the sample rack from the bucket  361  to the rack buffer section  302  in the cold container ( FIG. 15 ). Use of the sample rack allows the sample to easily be moved even if there is a groove extending in the width direction of the cold container door. Furthermore, because the carriage  363  is set in the groove provided on the bottom surface of the sample rack from bottom to top, a sample rack can be moved over any width of the cold container  31 . After the sample rack is moved to the rack buffer section  302  in the cold container, the carriage  363  is moved downward and the X drive motor  365  is driven to move the X-axial mechanism  362  to a position under the bucket  361  ( FIG. 16 ). At the same time, the rack transfer mechanism  360  drives the cold container door  31  in the lateral direction to close the door. 
         [0042]    Description of the example above is based on a case where the cold container door  31  is moved in the lateral direction when opened or closed, but the cold container door  31  may be moved in any direction or rotated so long as a space for carrying in and out a sample rack is provided. Also the description is based on a case where the sample rack is transferred from the bucket  361  to the rack buffer section  302  in the cold container, but the present invention is not limited to this configuration, and the sample rack may be moved from the rack buffer section  302  to the bucket  362 . 
         [0043]    As described above, because a slot which has a sample rack set in the stand-by state for transfer is independently provided from the bucket  361  as is the rack buffer section  302 , random access to any sample rack is possible. 
         [0044]    Furthermore the description is based on a case where a driving section is moved into a bottom portion of a sample rack for movement of the cold container door over a width of the groove, but it is possible to use such a ratchet mechanism as to press a front or rear portion of a sample rack. Even if a width of the groove causes a problem for smooth movement of the sample rack, the problem can easily be solved by providing a guide mechanism operating in synchronism to an operation of the ratchet mechanism for feeding or returning a sample rack. 
         [0045]    Operations of the mechanisms described above are controlled by a transfer control computer having microprocessors not shown and incorporated in this system according to information or instruction from a host computer not shown in the figure. Although the cold container is controlled in temperature by a dedicated control unit, it may be controlled by the transfer control computer if the computer affords to carry out the operation.