Patent Publication Number: US-6985828-B2

Title: Loading-assisting apparatus for use with centrifuge

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-342515, filed Nov. 26, 2002, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a loading-assisting apparatus which is designed for use with a centrifuge, and which is used to make a weight adjustment to samples (e.g., blood samples) to be processed when the samples are loaded in the centrifuge. 
     2. Description of the Related Art 
     When blood samples are subject to centrifugal separation, there are two ways for loading. In one way, sample vessels holding blood samples to be tested are individually loaded in the centrifuge. In the other way, the sample vessels holding blood samples to be tested are first arranged and held in a rack, and then this rack is loaded in the centrifuge. In either way, sample groups corresponding to the respective buckets of the rotor of the centrifuge must be balanced in weight. If they are not, the rotor of the centrifuge loses its weight balance as determined in the circumferential direction. As a result, the rotor of the centrifuge does not rotate smoothly. 
     Centrifuges that aim to prevent an imbalanced state of rotors have been proposed to date. For example, Jpn. Pat. Appln. KOKAI Publication No. 06-320052 discloses a centrifuge wherein an imbalance correction mechanism comprising a position-adjustable weight is provided on a rotation table (i.e., a rotor) at a position adjacent to a sample cassette. Jpn. Pat. Appln. KOKAI Publication No. 2002-273271 discloses a centrifuge using a dummy centrifugal tube having a substantially equivalent weight to that of a sample-holding centrifugal tube. The dummy centrifugal tube is provided for the rotor, as needed. 
     In the centrifuge disclosed in Jpn. Pat. Appln. KOKAI Publication No. 06-320052, the rotating table (rotor) has to be provided with the imbalance correction mechanism as well as sample cassettes. This inevitably complicates the structure of the centrifuge and increases the size of the centrifuge. 
     The centrifuge disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2002-273271 has problems in that it requires a manual operation. To be more specific, the rotor of this centrifuge is rotated to check its rotating condition. In accordance with the checked rotating condition, the dummy centrifugal tube is manually replaced with another. Since adjustment made to balance the weight of the entire rotor takes time, smooth centrifugal processing cannot be expected. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a loading-assisting apparatus designed for use with a centrifuge, which has the following advantages: 
     a) Reliable rotation of the rotor is ensured with no need to complicate the centrifuge or increase its size. 
     b) Adjustment for balancing the weight of the entire rotor can be made quickly and reliably. 
     To achieve the above object, the present invention provides a loading-assisting apparatus which is designed for use with a centrifuge, and which has the features described below. Other features of the present invention will become apparent from the descriptions of embodiments given below. 
     The loading-assisting apparatus for use with a centrifuge, which embodies the present invention, comprises: a measuring device configured to measure the weight of each of sample groups loaded in the buckets of the centrifuge; a determination device configured to determine how the measured weight of each sample group differs from a reference value; and an adjustment/loading device configured to make weight adjustments to each sample group in accordance with results of determination the determination device makes, and to load each sample group. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a schematic illustration of a loading-assisting apparatus for use with a centrifuge, according to the first embodiment of the present invention. 
         FIG. 2  is a block diagram showing the major portions of the loading-assisting apparatus of the first embodiment. 
         FIG. 3  is a schematic illustration of a loading-assisting apparatus for use with a centrifuge, according to the second embodiment of the present invention. 
         FIG. 4  is a block diagram showing the major portions of the loading-assisting apparatus of the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     (First Embodiment) 
       FIG. 1  shows a loading-assisting apparatus  100  for use with a centrifuge, according to the first embodiment of the present invention. This apparatus adjusts the weight variations of sample groups G (which are racks  30  holding sample vessels in the case of the first embodiment) transported in the direction of arrow X by an automatic transport device  1 , before the sample groups G (racks  30 ) are loaded in a centrifuge  2 . 
     The centrifuge  2  comprises: a motor M; a rotor R including a rotation disk D rotated by the motor M and buckets B swingably attached to the circumferential portions of the rotation disk D; a protection frame U that surrounds the rotor R; a rotation position sensor C which detects a rotation position of the rotor R; etc. 
     A measuring device  110  is located under the terminating end of the rack transport path of the automatic transport device  1 . By this measuring device  110 , the weights of the racks  30  holding sample vessels (i.e., the sample groups G to be processed by the centrifuge  2 ) are measured before the racks  30  are loaded in the centrifuge  2 . 
     The automatic transport device  1  is provided with a determination device  120  configured to determine the weight variations of the racks  30  holding the sample vessels. Based on the weights of the racks  30  measured by the measuring device  110 , the determination device  120  determines weight variations of the sample groups G loaded in each bucket B of the centrifuge  2 . 
     The weight variations are determined using reference weight values. 
     An adjusting/loading device  130  is provided above the automatic transport device  1 . based on the results of the determination the determination device  120  makes, the adjusting/loading device  130  weight adjustments to the racks  30  holding sample vessels. After this weight adjustment, the racks  30  holding sample vessels are loaded in the centrifuge  2 , as indicated by arrow P. 
       FIG. 2  is a block diagram showing the major portions of the loading-assisting apparatus of the first embodiment. As shown in  FIG. 2 , the determination device  120  includes a comparator  125  and a reference data memory  126 . The comparator  125  compares signals supplied from the measuring device  110  (i.e., measurement data V representing the weights of the sample vessel-holding racks  30  which are groups G of samples to be processed) with weight reference data W stored in the reference data memory  126  and corresponding to the groups G of samples to be processed. Based on the comparison, the comparator  125  generates and outputs variation ranking signals    0 , a, b, c, d  and  e . 
     Ranking signal    0    represents that the difference between measurement data V and reference data W is within an allowable variation range. 
     Ranking signal  a  represents that the difference between measurement data V and reference data W is less than variation S 1 . 
     Ranking signal  b  represents that the difference between measurement data V and reference data W is less than variation S 2 . 
     Ranking signal  c  represents that the difference between measurement data V and reference data W is less than variation S 3 . 
     Ranking signal  d  represents that the difference between measurement data V and reference data W is less than variation S 4 . 
     Ranking signal  e  represents that the difference between measurement data V and reference data W exceeds variation S 4 . 
     Variation S 1  is determined beforehand. For example, it corresponds to the weight of one sample vessel or about one fifth to half of that weight. 
     As shown in  FIG. 2 , the adjusting/loading device  130  includes an operation robot  131  and a dummy storage  132 . The operation robot  131  operates in accordance with variation ranking signals    0 , a, b, c, d  and  e  supplied from the determination device  120 . The dummy storage  132  has shapes and dimensions similar to those of a sample vessel  3 , and stores a plurality of dummy objects Q whose weights correspond to variations S 1  to S 4 . 
     Upon receipt of variation ranking signal    0   , the operation robot  131  loads the sample vessel-holding rack  30  into the centrifuge  2  as it is. 
     Upon receipt of variation ranking signal  a , the operation robot  131  takes out a dummy object Q 1  whose weight corresponds to variation S 1  from the dummy storage  132 , and adds it to the sample vessel-holding rack  30 . Then, the operation robot  131  loads the sample vessel-holding rack  30  into the centrifuge  2 , with the dummy object Q 1  added thereto. 
     Upon receipt of variation ranking signal  b , the operation robot  131  takes out a dummy object Q 2  whose weight corresponds to variation S 2  from the dummy storage  132 , and adds it to the sample vessel-holding rack  30 . Then, the operation robot  131  loads the sample vessel-holding rack  30  into the centrifuge  2 , with the dummy object Q 2  added thereto. 
     The operation robot  131  operates in similar manners when it receives variation ranking signals  c , and  d . In other words, the operation robot  131  receives variation ranking signals, adds dummy objects Q whose weights correspond to the variation ranking signals to the sample vessel-holding racks  30 , and then loads the racks  30  to the centrifuge  2 , with the objects Q added thereto. 
     Upon receipt of variation ranking signal  e , the operation robot  131  regards the corresponding sample vessel-holding rack  30  as an abnormal rack, i.e., a rack whose weight cannot be adjusted. In this case, the operation robot  131  returns the abnormal rack to its original position, as indicated by arrow E, and simultaneously issues an abnormality notification signal. 
     (Second Embodiment) 
       FIG. 3  shows a loading-assisting apparatus  200  for use with a centrifuge, according to the second embodiment of the present invention. This apparatus sequentially loads objects G to be processed (sample vessels  3  in the second embodiment), which are transported in the direction of arrow X by an automatic transport device  1 , into the centrifuge  2 . Simultaneous with this loading operation, the apparatus  200  makes weight adjustments to eliminate the adverse effects stemming from the weight variations of the sample vessels  3  (i.e., the objects to be processed). 
     A measuring device  210  is located under the terminating end of the rack transport path of the automatic transport device  1 . By this measuring device  210 , the weights of the sample vessels  3  to be processed by the centrifuge  2  are individually measured before the vessels  3  are loaded in the centrifuge  2 . 
     The automatic transport device  1  is provided with a determination device  220  configured to determine the weight variations of the sample vessels  3 . Based on the weights of the sample vessels  3  measured by the measuring device  210 , the determination device  220  determines weight variations of the sample groups G to be loaded in the buckets B of the centrifuge  2 . The weight variations are determined using reference weight values corresponding to the respective sample groups G. 
     An adjusting/loading device  230  is provided above the automatic transport device  1 . The adjusting/loading device  230  is provided with means for sequentially loading the sample vessels  3  in the buckets B of the centrifuge  2  after the weight measurement by the measuring device  210 , and means for making weight adjustment to the groups G already loaded in the buckets B. 
       FIG. 4  is a block diagram showing the major portions of the loading-assisting apparatus  200  of the second embodiment. As shown in  FIG. 4 , the determination device  220  includes first to fourth counters  221  to  224 , a comparator  225  and a reference data memory  226 . 
     The first to fourth counters  221  to  224  add the weights of the sample vessels  3  sequentially loaded in the buckets B of the centrifuge  2  in such a manner that a total weight is obtained for each of the processing groups G of the objects loaded in the buckets B. 
     The comparator  225  compares measurement data V 1 , V 2 , V 3  and V 4 , which represent the total weight of each group of objects to be processed, with reference data W stored in the reference data memory  226 . The comparator  225  includes means for generating variation ranking signals    0 , a, b, c, d , and  e  corresponding to the differences between the measurement data and the reference data, and for outputting these signals. 
     The adjusting/loading device  230  includes an operation robot  231  and a dummy storage  232 . The operation robot  231  sequentially loads the sample vessels, the weights of which are measured by the measuring device  210 , in the buckets B of the centrifuge  2 . In addition, the operation robot  231  operates in accordance with variation ranking signals    0 , a, b, c, d  and  e  supplied from the determination device  220 . The dummy storage  232  has shapes and dimensions similar to those of a sample vessel  3  and stores a plurality of dummy objects Q whose weights correspond to variations S 1  to S 4 . 
     When variation ranking signal    0    is received, the operation robot  231  does not make any adjustment to the sample vessel  3  loaded in the centrifuge  2 . 
     Upon receipt of variation ranking signal  a , the operation robot  231  takes out a dummy object Q 1  whose weight corresponds to variation S 1  from the dummy storage  232 , and adds it to the processing group G that requires the weight adjustment. 
     Upon receipt of variation ranking signal  b , the operation robot  231  takes out a dummy object Q 2  whose weight corresponds to variation S 2  from the dummy storage  232 , and adds it to the processing group G that requires the weight adjustment. 
     The operation robot  231  operates in similar manners when variation ranking signals  c , and  d  are supplied thereto. In other words, the operation robot  231  receives variation ranking signals, adds dummy objects Q whose weights correspond to the variation ranking signals to the processing groups G that require weight adjustment. 
     Upon receipt of variation ranking signal  e , the operation robot  231  regards the corresponding processing group G as an abnormal group, i.e., a group whose weight cannot be adjusted. In this case, the operation robot  231  unloads the sample vessels  3  of the abnormal group G from the centrifuge  2  and returns them to their original positions, as indicated by arrows E 1  and E 2 . Simultaneous therewith, the operation robot  231  issues an abnormality notification signal. 
     (Features of the Embodiments) 
     
         
         [1] A loading-assisting apparatus ( 100 ,  200 ) for use with a centrifuge, according to an embodiment, comprises: 
       
    
     a measuring device ( 110 ,  210 ) configured to measure the weight corresponding to each of the processing groups G loaded in the buckets B of a centrifuge ( 2 ); 
     a determination device ( 120 ,  220 ) configured to determine a variation of the weight of each of the processing groups G with reference to the corresponding reference value, the determination being based on the weight of each of the processing groups G measured by the measuring device; and 
     an adjusting/loading device ( 130 ,  230 ) configured to make predetermined weight adjustment to each of the processing groups G in accordance with the determination the determination device makes, and to subsequently load the processing groups G in the centrifuge ( 2 ). 
     The loading assisting apparatus adjusts the weight balance of the processing groups G when the processing groups G are loaded in the buckets B of the centrifuge ( 2 ). Therefore, the centrifuge ( 2 ) can rotate smoothly, ensuring reliable centrifugal processing.
     [2] A loading-assisting apparatus  100  for use with a centrifuge, according to the embodiment, comprises:   

     a measuring device  110  configured to measure the weight corresponding to each of processing groups G (i.e., racks  30  that holds sample vessels) before the processing groups G are loaded in the buckets B of a centrifuge  2 ; 
     a determination device  120  configured to determine a variation of the weight of each of the processing groups G with reference to the corresponding reference value, the determination being based on the weight of each of the processing groups G (i.e., sample vessel-holding racks  30 ) measured by the measuring device; and 
     an adjusting/loading device  130  configured to make predetermined weight adjustment to each of the processing groups G (sample vessel-holding racks  30 ) in accordance with the determination the determination device  120  makes, and to subsequently load the processing groups G in the centrifuge  2 . 
     The loading assisting apparatus described above adjusts the weight balance of the processing groups G (sample vessel-holding racks  30 ) before the processing groups G are loaded in the centrifuge  2 . Therefore, the weight adjustment can be made with comparative ease, and the centrifuge  2  can rotate smoothly, ensuring reliable centrifugal processing.
     [3] In the loading-assisting apparatus  100  for use with a centrifuge, as defined in [2] above, the determination device  120  compares measurement data V, which represent the weight of each group of objects to be processed, with reference data W, and generates and outputs variation ranking signals    0 , a, b, c, d , and  e  corresponding to the differences between the measurement data and the reference data.   

     The loading-assisting apparatus  100  described above is advantageous in that it can effectively cope with the weight imbalance of the processing groups G (racks  30  that hold the sample vessels).
     [4] In the loading-assisting apparatus  100  for use with a centrifuge, as defined in [3] above, the adjusting/loading device  130  includes means for adding a dummy object Q to each of the processing groups G (racks  30  that hold sample vessels) in accordance with the variation ranking signals    0 , a, b, c, d , and  e  transmitted from the determination device  120 , and then performing a loading operation P with reference to the buckets B of the centrifuge  2 .   

     In the loading-assisting apparatus  100  for use with a centrifuge, the dummy objects Q whose weights are suitable to adjust the weight imbalance of the processing groups G (racks  30  that hold sample vessels) are added to the processing groups G to be processed by the centrifuge  2 . Accordingly, the centrifuge  2  can rotate smoothly, thus ensuring reliable centrifugal processing.
     [5] A loading-assisting apparatus  200  for use with a centrifuge, according to the embodiment, comprises:   

     a measuring device  210  configured to individually measure the weights of the objects  3  (i.e., sample vessels  3  to be processed by the centrifuge) before the objects  3  to be processed are loaded in the centrifuge  2 ; 
     means for sequentially loading the objects  3  in the buckets B of the centrifuge  2  after the measuring device  210  measures the weights of the objects  3 ; 
     counters ( 221 ,  222 ,  223 ,  224 ) configured to add the weights of the objects  3  sequentially loaded in the buckets B of the centrifuge  2  in such a manner that a total weight is obtained for each of the groups G of the objects loaded in the buckets B; 
     a determination device  220  configured to determine a variation of the weight of each of the processing groups G with reference to the corresponding reference value, the determination being based on the weight of each of the processing groups G measured by the measuring device; and 
     an adjusting/loading device  230  configured to make weight adjustment to the groups G already loaded in the buckets B, in accordance with the determination the determination device  220  makes. 
     The loading-assisting apparatus  200  described above is advantageous in that it can adjust the weight balance of the processing groups G in the buckets even where the sample vessels  3  are loaded in the buckets of the centrifuge sequentially and individually.
     [6] In the loading-assisting apparatus  200  for use with a centrifuge, as defined in [5] above, the determination device  220  compares measurement data V 1 , V 2 , V 3  and V 4 , which represent the total weight of each group G of objects to be processed, with reference data W, and generates and outputs variation ranking signals    0 , a, b, c, d , and  e  corresponding to the differences between the measurement data and the reference data.   

     This loading-assisting apparatus  200  produces similar advantages to those of the apparatus described above [3].
     [7] In the loading-assisting apparatus  200  for use with a centrifuge, as defined in [6] above, the adjusting/loading device  230  includes means for adding a dummy object Q to each of the processing groups G loaded in the buckets B in accordance with the variation ranking signals    0 , a, b, c, d , and  e  transmitted from the determination device  220 .   

     This loading-assisting apparatus  200  produces similar advantages to those of the apparatus described above [4].