Automatic analyzer and sample-processing system

A sample-processing system that improves total system processing efficiency, and reduces a sample-processing time, by establishing a functionally independent relationship between a rack conveyance block with rack supply, conveyance, and recovery functions, and a processing block with sample preprocessing, analysis, and other functions. A buffer unit with random accessibility to multiple racks standing by for processing is combined with each of multiple processing units to form a pair, and the system is constructed to load and unload racks into and from the buffer unit through the rack conveyance block so that one unprocessed rack is loaded into the buffer unit and then upon completion of process steps up to automatic retesting, unloaded from the buffer unit. Functional dependence between any processing unit and a conveyance unit is thus eliminated.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to sample-processing systems. More particularly, the invention relates to a sample-processing system suitable for efficient operation of a plurality of analyzers different in functionality and in processing capabilities and interconnected using a conveyor line to convey sample racks.

2. Description of the Related Art

Analytical results on blood plasma, serum, urine, and other biological samples provide large volumes of useful information for diagnosing medical conditions, and there are a large number of conventional techniques relating to analyzers intended for automatic processing of such biological samples.

JP-A-10-19899, for example, discloses a technique on which is based an automatic analyzer that includes a plurality of analytical units each equipped with transfer means for loading a rack into the analytical unit, with transfer means provided independently of the former transfer means in order to unload the rack from the analytical unit, and with discrimination means provided on the upstream side of the analytical unit in order to discriminate a request item for a sample. The analyzer, after judging which of the multiple analytical units is to be used to analyze the sample, assigns a rack-loading instruction to an appropriate analytical module.

Also, JP-A-10-213586 describes an automatic analyzer equipped with a plurality of analytical units along a belt conveyor line, with a rack supply unit at one end of the conveyor line, and with a rack recovery unit at the other end of the conveyor line. A standby unit for causing racks to stand by for processing is further disposed in front of the rack recovery unit so as to allow automatic retesting.

In addition, JP-A-279357 describes an automatic analyzer in which a standby disc for causing racks to stand by for processing is disposed on a rack conveyance route between a rack supply unit and an analytical unit, the standby disc being provided for avoiding congestion on the rack conveyance route and for automatic retesting.

SUMMARY OF THE INVENTION

In the automatic analyzer of JP-A-10-19899, a rack conveyance route is determined before the rack is conveyed to the analytical unit. When analysis by multiple analytical units is required, therefore, since samples will be conveyed in order from the upstream side, if there are a large number of samples to be analyzed on the upstream side, the rack conveyance route will become congested and none of any samples to be analyzed only on the downstream side will be able to move past a sample existing upstream.

In the automatic analyzer of JP-A-10-213586, although a return route is provided to convey racks from the downstream side to the upstream side, when a rack is conveyed to a downstream analytical unit first, it will be absolutely necessary that the rack, before being conveyed to an upstream analytical unit, be returned to the rack supply unit located at the uppermost position of the upstream side. In addition to consuming time, such a conveying sequence will obstruct the processing of the racks supplied from the supply unit.

Additionally, the samples that require automatic retest will be concentrated at the standby unit in front of the recovery unit. In a system configuration with a plurality of analytical units each different in processing rate, therefore, even when a rack is present that contains samples whose analytical results have already been output and which are to undergo retests, an unnecessary waiting time will occur since that rack will be unable to pass a rack that has entered the standby unit earlier. Furthermore, for retesting, the rack will need to be returned to the rack supply unit similarly to the above, so the conveying sequence in this case as well will correspondingly consume time and obstruct the processing of the racks supplied from the supply unit.

In the automatic analyzer of JP-A-279357, although the rack standby unit has circular disc construction and is therefore excellent in random accessibility to racks, a dead space occurs on the disc since the racks themselves are of a general shape close to a rectangle. Also, the dead space in the entire system due to the use of the circular disc is large.

Additionally, in a system configuration with a plurality of analytical units, since the rack is conveyed to a downstream analytical unit through the standby disc, the direction of the rack becomes inverse and the traveling direction of the rack needs to be returned to its original direction in front of the next analytical unit.

An object of the present invention is to provide a sample-processing system optimized in terms of total system process flow by assigning only a rack conveyance function to a rack supply unit, a conveying unit, and a recovery unit, as their intended purpose, and assigning all other characteristic and necessary functions of processing units to each of the processing units.

Among major problems associated with conventional techniques is that the rack conveyance unit has a functional block that the standby unit and other analytical units require.

A system according to the present invention includes a buffer unit that causes a plurality of racks to stand by for processing and has random accessibility to each rack, and the buffer unit is combined with each of multiple processing units to form a pair. The system is also constructed to load/unload each rack into/from the buffer unit. One unprocessed rack is loaded into the buffer unit and then upon completion of process steps up to automatic retesting, the rack is unloaded from the buffer unit. Functional dependence between any processing unit and a rack conveyance unit is thus eliminated.

In addition, if a rack transfer block that uses the buffer unit to transfer racks to and from a rack conveyance block is constructed to be able to access both a feed route and return route of the racks conveyed by the rack conveyance unit, minimizing a conveying distance between processing units allows the system to start the earliest executable process first, without being aware of the layout order of multiple processing units, even when the kind of processing of a particular sample spans the multiple processing units. This, in turn, makes it unnecessary to determine the entire rack conveyance route on the upstream side of the system. In addition, upon completion of processing in one processing unit, loads of other processing units can be confirmed, so the rack can be conveyed to the processing unit whose load is the lightest of all processing unit loads. A processing time of the entire system is reduced as a result.

A sample-processing system optimized in terms of total system process flow can be provided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described hereunder.

FIG. 1is a plan view of a sample-processing system according to an embodiment of the present invention. The system shown as an example inFIG. 1includes: a sampler unit100for loading and storing a sample rack; a rack conveyance unit200for conveying the sample rack between the sampler unit and the functional modules; buffer units300aand300beach disposed along the rack conveyance unit200, for transferring the sample rack to and from the rack conveyance unit200and for causing temporary standby of the sample rack; functional modules400aand400beach paired with the buffer unit300aor300band located to the right thereof; and a supplemental module500located to the left of the buffer unit300a.

FIG. 2shows the system ofFIG. 1in functionally classified form. In this case, constituent elements of the system can be classified into a functional block1including the buffer unit300a, the functional module400a, and the supplemental module500in order to undertake sample analysis, preprocessing, and other processes, a functional block2including the buffer unit300band the functional module400b, and a sample rack conveyance block3including the sampler unit100and the rack conveyance unit200. The functional block1, the functional block2, and the conveyance block3deliver and receive sample racks to and from each other at connections4and5.

While the functional blocks in the present embodiment are each constructed of a buffer unit and a functional module, a functional module including a buffer unit therein is also embraced in the present invention.

Also, the functional block1, the functional block2, and the conveyance block3are constructed so that input and output sections required for each will be connected to equipment of related facilities independently of each other. In addition, except for processes relating to the exchange of sample racks between the three blocks, that is, physical movement of each sample rack, issuance of processing requests concerning samples, transmission of results, and exchange of other information, the functional blocks1,2and the conveyance block3are constructed to be operable in completely independent form.

Each constituent unit of the system, and total system operation will be described hereunder.

A configuration of the sampler unit100is shown inFIG. 3.

The sampler unit100includes: a loader101for loading a sample rack into the system; a storage section102for unloading sample racks from the system; a load rack moving unit103for transferring a loaded sample rack from the loader to the rack conveyance unit200; a rack ID reading unit104for reading identification (ID) information assigned to the sample rack; a sample vessel height detection unit105for confirming whether sample vessels are set up on the sample rack, and detecting the height of each sample vessel; a sample ID reading unit106for reading, for example, an ID label of the sample, affixed to the sample vessel set up on the sample rack; a sample vessel rotating unit107for rotating the sample vessel during the reading of the sample ID; an unload rack moving unit108for moving the rack from the rack conveyance unit200to the storage section102; an emergency-test sample loader109for loading an emergency-test sample rack into the sample-processing system or for loading thereinto a sample rack conveyed from a rack conveyance system connected on the upstream side of the sample-processing system; and a rack unloader110for unloading the sample rack into the rack conveyance system connected on the upstream side of the sample-processing system.

The loader101includes a loading tray setup unit121in which to set up a sample rack tray capable of being hand-carried with a plurality of sample racks set up thereon, and a loading buffer122disposed between the tray setup unit and the load rack moving unit103. The loader101also has a loading lever123functioning as a driving mechanism to convey the sample racks in a Y-direction. In addition, the loader101has a loading mechanism124(seeFIG. 4) that is adapted to rotate the loading lever axially in the Y-direction.

After a sample rack tray has been set up in the loading tray setup unit121, the loading mechanism124activates a rotating motor125to rotate the loading lever123, and drives a moving motor126to move the sample rack tray in the Y-direction. The sample racks on the tray are thus conveyed to the load rack-moving unit103through the loading buffer122. After all racks have moved out from the loading buffer122, the loading mechanism124rotates the loading lever123. The lever then returns to a required sample rack tray setup position and stands by for the next sample rack tray to be set up thereat.

Upon completion of the movement of all sample racks from the sample rack tray to the loading buffer122, the sample rack tray is removable, thus allowing setup of the next sample rack tray. In this case, after moving out all racks from the loading buffer122, the loading lever123of the loading mechanism124usually conducts a rack-loading process upon the sample rack tray that has been newly set up in place. Instead, however, the loading process for the sample racks in the loading buffer122can be interrupted using a switch (not shown) that is provided on the sampler unit100, or in accordance with an operator instruction from a screen of an operating unit. After the interruption, the loading lever123can be returned to the load tray setup position121in order to restart the feed operation for the racks on the sample rack tray.

In addition, the present embodiment has two sample-loading units, and when the rack feed operation by one of the units is completed and all racks are gone from the particular unit, the other unit conducts a rack feed operation. While the present embodiment has two sample-loading units, processing in an arrangement of more than two units also advances similarly.

After receiving the rack from the loading unit, the load rack moving unit103transfers the rack to the rack ID reading unit104, by which the ID of the rack is then read and the rack is further transferred to the sample vessel height detection unit105.

The sample vessel height detection unit105confirms whether sample vessels are set up in internal positions of the sample rack, and detects the height of each sample vessel.

After this, the sample rack is moved to a sample ID reading position, at which the IDs of each sample are then read by the sample ID reading unit106. A sample-vessel rotating unit107is equipped at the sample ID reading position.

In general, bar codes are used as sample IDs. Also, cups, test tubes, test tubes each with a cup thereupon, or other various kinds of objects are used as sample vessels. The bar codes as sample IDs, because of a dimensional requirement for each to have a necessary amount of information, are usually labeled onto test tubes only. During the processing of samples, therefore, whether the sample ID is to be read and whether the sample vessel is to be rotated are judged from the foregoing rack ID information and sample vessel height information.

Necessary processes for the sample rack are determined from the above rack ID and sample ID information. Also, functional modules are determined as conveyance destinations.

After the conveyance destinations of the sample rack have been determined, the load rack-moving unit103moves the rack to the rack conveyance unit200.

An emergency-test sample rack or a sample rack from a sample conveyance system connected on the upstream side of the sampler unit100is loaded from the emergency-test sample loader109into the sampler unit. The rack that has been loaded from the emergency-test sample loader109undergoes substantially the same kind of processing as that of the above-described rack loaded from the sample loader101, and then moves to the rack conveyance unit200.

Also, the sample rack that has gone through the necessary processes in each functional module is moved to the storage section102by the unload rack moving unit108.

As with the loader101, the storage section102includes an unloading tray setup unit131in which to set up a sample rack tray capable of being hand-carried with a plurality of sample racks set up thereon, and an unloading buffer132disposed between the loading tray setup unit and the load rack moving unit103. An unloading lever133for conveying the sample racks in a Y-direction is also equipped as a driving mechanism.

The sample racks that have been conveyed to a front area of the storage section102by the unload rack moving unit108are conveyed to the unloading buffer132through a load rack moving lane by the unloading lever133, and when the unloading buffer132is filled with as many sample racks as mountable on one sample rack tray, the racks are each moved to the tray.

Instead, the sample racks in the unloading buffer132can be moved to the sample rack tray in the unloading tray setup unit131by operating a switch (not shown) that is provided on the sampler unit100, or by sending an operator instruction from a screen of an operating unit (not shown).

The sample-processing system further has the rack unloader110for unloading a sample rack into the sample conveyance system connected on the upstream side of the sample-processing system. The rack unloader110is of a size adapted for holding one rack, and is also constructed to be slidable in a Y-direction so that a position for Y-axial unloading of the rack into the sample conveyance system can be changed.

The rack conveyance unit200inFIG. 1has two rack conveyance lanes, namely, a feed lane201for conveying sample racks from the sampler unit100to the functional modules400a,400b, and a return lane202for conveying the sample racks from the functional modules400a,400bto the sampler unit100. The rack conveyance unit200also has a belt mechanism210, a stopper mechanism220(220aand220b) and a shutter mechanism230, as shown inFIG. 5.

The belt mechanism210uses conveyor belts to convey the sample racks between the sampler unit100and the functional modules400a,400b, along the feed lane201and the return lane202. In the present embodiment, one conveyor belt is used for the feed lane and the return lane each, and a conveyor belt-driving motor211(211aand211b) and a belt-tensioning mechanism212(212aand212b) are equipped at a terminatory section of the rack conveyance unit200. This scheme allows rapid sample rack conveyance. Also, this scheme is suitable for a system with a random-conveyance ability to convey sample racks to a plurality of functional modules or bi-directionally between the functional modules arranged on the upstream and downstream sides of the system. Although no description is given in the present embodiment, this scheme may be suitable for a processing system in which, as in a sample preprocessing system, the same sample rack stops at a plurality of functional modules, for example, centrifuging, decapping, and pipetting modules in order from the upstream side of the system to the downstream side to undergo processing. In that case, a plurality of conveyor belts with a length equal to the width of each functional module are arranged in series, and during processing, the sample rack is delivered and received between adjacent conveyor belts. It is desirable, therefore, that an appropriate mechanical configuration of belts be selectable to suit a particular configuration of the system and necessary processing capabilities thereof.

The stopper mechanism220for stopping the sample rack at predetermined positions on sample rack loading routes to each functional module has a stopper220afor the feed lane201and a stopper220bfor the return lane202.

The shutter mechanism230has a total of three vertically movable rack guide plates, two for rack guiding on the feed lane201and one for rack guiding on the return lane202, and moves downward only for sample rack unloading into each functional module or for sample rack loading therefrom.

A configuration of a buffer unit300is shown inFIG. 5.

The buffer unit300including a rack-unloading standby section301, a buffer302, a cold-storage section303, a module loading/unloading standby position304, a rack conveyance section310, a one-rack loader/unloader320, and an ID reader321, moves the sample rack via rack-unloading mechanisms370and371.

The rack-unloading standby section301is a position having a space for causing one rack to stand by, and at this standby position, the sample rack from the rack conveyance unit200is transferred to the buffer unit300. This standby position is also where a sample rack to be unloaded from the buffer unit300into the rack conveyance unit200is made to stand by.

The buffer302further includes a plurality of independent slots in each of which a sample rack can be made to stand by temporarily.

The cold-storage section303is constructed so that a plurality of sample racks, each containing accuracy management samples or other samples that require periodic processing in the functional modules, can be made to stand by inside. The cold-storage section303has a cold-storage function to prevent these samples from evaporating.

The module loading/unloading standby section304is a position having a space for causing one rack to stand by, and at this standby position, the sample rack from the buffer unit300is unloaded into the functional module400. This standby position is also where a sample rack that has undergone processing in the functional module is loaded into the buffer unit300.

The rack conveyance section310conveys the sample rack between the module loading/unloading standby position304and the functional module400.

The one-rack loader/unloader320functions as a sample loader/unloader for processing the sample rack in the functional module without involving the rack conveyance unit200.

A rack transfer mechanism330transfers the sample rack bi-directionally in a Y-direction between the rack loading/unloading standby section301and the feed lane201of the rack conveyance unit200, and between the rack loading/unloading standby section301and the return lane202. For sample rack transfer in one direction only, the sample rack can usually be moved horizontally if the rack conveyance surface height existing after the rack has been moved is adjusted to be slightly smaller than the rack conveyance surface height existing before the rack is moved. In the present system, however, the transfer mechanism330also needs to have a function that lifts the rack in a Z-direction, because bi-directional movement is required and because the rack needs to cross the feed lane201to move to and/or from the return lane202.

The rack transfer mechanism330is further detailed below usingFIGS. 6 to 10. Rack transfer from the feed lane201of the rack conveyance line200to the rack loading/unloading standby section301is taken as an example in the description.

The rack transfer mechanism330includes a gripper340and a Y-mover350. The gripper340has a function that opens/closes two gripping plates in a Y-direction to grip the rack, and a function that lifts the gripped rack in a Z-direction. The Y-mover350moves the gripper in the Y-direction.

The gripper340includes a pulley343that transmits driving force using a motor341and a belt342, a rotating shaft344of the pulley, two gripping plates346fitted with cam followers345and movable vertically in the Z-direction, and a spring347that works in a direction to draw the gripping plates346closer to the spring. Also, the pulley343has two bearings348and the rotating shaft344of the pulley has a stepped cam349.

The buffer unit300activates a driving motor351of the Y-mover350in the rack transfer mechanism330, thus moving the gripper340to the feed lane201of the rack conveyance line200in order to load a sample rack. At this time, the gripper340is in an open condition, that is, with the two gripping plates346pushed open by the two bearings348fitted in the pulley343, and with the cam followers345and the cam349not in contact with each other.

The rack conveyance unit200drives the stopper220adisposed at the rack transfer position in the buffer unit300, and protrudes the stopper above the feed lane201. After this, the rack conveyance unit200drives a motor211aof the belt mechanism210and moves the sample rack.

The gripper340rotates the pulley343by driving the motor341to grip the sample rack that has stopped at the transfer position. The rotation of the gripper moves the bearings348, closes the two gripping plates346in the Y-direction by the pulling force of the spring347, and grips the sample rack, as shown inFIG. 7. Further rotation of the motor341brings the bearings348into a non-contact state with respect to the gripping plates346, thus moving the cam followers345onto an elevated section of the cam, as shown inFIG. 8, and consequently moving the two gripping plates346upward to allow rack lifting in the Z-direction.

After the gripper340has lifted the sample rack in the Z-direction, the rack conveyance unit200drives a motor of the shutter230and moves the shutter231downward.

After the shutter231has moved downward, the rack transfer mechanism330drives the motor351of the Y-mover and moves the sample rack in the Y-direction for transfer to the rack loading/unloading standby section301.

Upon completion of the sample rack transfer, the rack conveyance unit200returns the stopper220afrom the feed lane and moves the shutter230upward for the next sample rack transfer.

After the movement of the sample rack to the rack loading/unloading standby section301, the gripper340releases the gripped condition of the sample rack. This operation is conducted by rotating the motor341in an inverse direction relative to the rotating direction for gripping the rack, and the release is conducted in order reverse to that of gripping.

While the gripper in the present embodiment is constructed to lift the sample rack in operational association with the opening/closing operation of the gripping plates by driving one motor, substantially the same effect can be obtained by providing an independent motor for the gripping plate opening/closing operation and the rack-lifting operation each.

A rack-moving mechanism360includes a bucket361adapted to hold one rack and move in the Y-direction, an X-mover362that moves in the Y-direction with the bucket to move the internal rack thereof in an X-direction, and a vertically movable carriage363installed in the X-mover362.

The rack-moving mechanisms are further detailed below usingFIGS. 11 to 14with the sample rack transfer from the rack loading/unloading standby section301to the buffer302taken as an example in the description.

First, the rack-moving mechanism360drives a Y-driving motor364to move the bucket361to the position of the rack loading/unloading standby section301, as shown inFIG. 11. At the same time, the rack-moving mechanism360also drives an X-driving motor365to move the carriage363of the X-mover362to a position under the sample rack in the rack loading/unloading standby section301, and after the carriage363has moved to a position at which the carriage gets into a bottom groove of the sample rack, moves a Z-driving motor366to move the carriage upward, as shown inFIG. 12.

The bucket361and a sample rack conveyance surface of the rack loading/unloading standby section301both have a slit367to make the carriage363movable in an upward moved condition in the X-direction. A like slit is also provided in the buffer302, the cold-storage section303, and other sections using the rack-moving mechanism360to move the sample rack.

Next, the rack-moving mechanism360moves the carriage363under the bucket361by driving the X-driving motor365to move the sample rack to the bucket, as shown inFIG. 13.

After the sample rack has been moved to the bucket361, the rack-moving mechanism360drives the Y-driving motor364to move the bucket361to a destination slot in the buffer302. At this time, the carriage363remains in an upward position to prevent the rack in the bucket from moving in the X-direction and sliding out from the bucket.

After the bucket has moved to the slot in the buffer302, the rack-moving mechanism360moves the carriage363under the slot by driving the X-driving motor365to move the sample rack to the slot, as shown inFIG. 14.

In the present embodiment, rack movement from the rack loading/unloading standby section301to the bucket361has been described. Sample racks are also moved from other sections such as the buffer302or cold-storage section303to the bucket361in essentially the same manner. In addition, while rack movement from the bucket361to the buffer302has been described, sample racks are moved to the cold-storage section303, the module loading/unloading standby position304, and other sections, in essentially the same manner. Constructing other sections so as to have independent standby slots for sample racks allows random accessing of any rack.

Next, transferring a sample rack from the buffer unit300to the functional module400is described below usingFIG. 15.

The sample rack transferred to the functional module400is moved to the module loading/unloading standby position304by the rack-moving mechanism360, and further moved to the rack conveyance section310by the rack-unloading mechanism370.

The rack conveyance section310takes a mechanical configuration suitable for the functional module involved. An example in which the functional module400is of a type that draws the sample rack from the rack conveyance section into the functional module and after execution of a necessary process such as pipetting, returns the sample rack to the rack conveyance section, is described in the present embodiment. Also, the functional module in the embodiment has a buffer capable of holding a plurality of racks in series inside.

The sample rack that has been moved to the rack conveyance section310by the rack-unloading mechanism370is moved on to a sample rack loading position401in the functional module by the rack-moving mechanism. The rack-moving mechanism here can be a belt mechanism such as the rack conveyance line200, or can be a mechanism such as a carriage.

The sample rack that has been drawn into the functional module400by a rack-loading mechanism thereof (not shown) is moved to a processing position402to undergo the necessary process such as pipetting. During this process, if a following sample rack to be processed in the functional module400is present, the buffer unit300moves the sample rack to the functional module via the rack conveyance section in essentially the same sequence. The functional module then causes the sample rack to stand by at a buffer position403in the module.

After being processed in the functional module400, the sample rack is once again returned to a rack-unloading position404on the rack conveyance section310by a rack-unloading mechanism not shown. The rack-moving mechanism moves the sample rack in a direction inverse to that of the transfer of the rack to the functional module400, thus unloading the rack into the module loading/unloading standby position304.

In the present embodiment, sample racks move bi-directionally between the buffer unit300and the rack conveyance section310, and rack loading/unloading to/from the buffer unit300is controlled according to the number of racks which can be held in the buffer of the functional module400. In other words, sample rack unloading from the buffer unit300is continued until the buffer of the functional module400has become full, but after the buffer has become full, the sample rack returned from the functional module400will be loaded into the buffer unit300, so the module loading/unloading standby position304is left empty and after the sample rack from the functional module400has moved inside the buffer unit300, the next sample rack is moved to the module loading/unloading standby position304and conveyed to the functional module400via the rack conveyance section310.

An example in which the functional module internally has a buffer function to hold a plurality of racks in series with respect to the processing position has been described in the present embodiment. However, essentially the same processing results can be achieved by, for example, using either a functional module of a type to and from which the sample rack can be loaded and unloaded at the same position in the module, or a functional module of a type in which the necessary process such as pipetting can be conducted on the conveyance line without involving rack loading/unloading. In that case, although the mechanical configuration of the rack conveyance section310requires a change, there is no need to change the buffer unit300or the rack conveyance logic.

Next, conveying a rack from the buffer unit300to the supplemental module500is described below usingFIG. 16. The supplemental module500in the present embodiment is disposed on the left side of the buffer unit300and has independent sample rack loading and unloading positions.

A sample rack to be unloaded into the supplemental module500is moved to the bucket361of the rack-moving mechanism360, and then further moved to a rack-unloading position501in the supplemental module500by rotational driving of the Y-driving motor364of the rack-moving mechanism360. After that, the rack-unloading mechanism371unloads the sample rack within the bucket361onto the conveyance line of the supplemental module by pushing out the rack.

The sample rack that has been carried into the supplemental module is provided with the necessary process, such as pipetting, at the processing position502and then moved to a rack unloading standby position503on the conveyance line.

At a sample rack unloading request from the rack unloading standby position503, the rack-moving mechanism360of the buffer unit300moves the bucket361to the rack unloading position503in the supplemental module by driving the Y-driving motor364. A rack-unloading mechanism504of the supplemental module moves the sample rack to the bucket361after that.

Next, the conveyance of a sample rack which has been loaded from the one-rack loader/unloader320is described below.

Upon setup of a sample rack in the one-rack loader/unloader320by an operator, the rack-moving mechanism360drives the Y-driving motor364to move the bucket361to the one-rack loading/unloading position320, and drives the X-driving motor365to move the carriage363upward to the position of the sample rack. After this, the sample rack is moved to the ID reading unit372, by which the rack ID is then read. This is followed by movement of the sample rack to a sample vessel detector373for sample vessel detection and sample ID reading. Data items of processing in the functional module are determined from the rack ID and sample ID information that has been read. The sample rack that has gone through sample ID reading is moved to the bucket361, then conveyed to the functional module and the supplemental module in accordance with the above-described conveying sequence, and undergoes processing. The sample rack thus processed is unloaded into the one-rack loader/unloader320via the bucket361in essentially the same manner as that described above. This completes the conveyance of the rack.

Even if the sampler unit100or the rack conveyance line200becomes inoperable for reasons such as a failure, processing in the functional module can be achieved by providing a sample rack loader/unloader such as the one-rack loader/unloader320shown in the present embodiment, and as described earlier in this Specification, adopting a configuration with independent supply lines for electric power, pure water, and other utilities. In addition, sample racks standing by in the buffer302of the buffer unit300, for example, can be unloaded from the one-rack loader/unloader320if the operator sends an unloading instruction from a switch or operating unit not shown.

Next, the cold-storage section303in which to make accuracy management samples stand by for processing is described below.

Accuracy management samples are samples whose data measurements are predetermined to verify validity or correctness of the measurement results obtained during analysis with the analyzer. Stability of the apparatus is confirmed by such verification. Accuracy management samples are measured for each of the analytical items periodically, that is, at previously set intervals of time.

After being loaded from the sampler unit100, a sample rack with accuracy management samples set up therein is transferred to the buffer unit300by the rack transfer mechanism330thereof. The process flow up to this step is substantially the same as the above.

When the accuracy management sample rack that has been loaded into the buffer unit300requires immediate analysis, the sample rack is transferred to the functional module400and the samples are analyzed. When immediate analysis is not required or after each sample has been analyzed in the functional module400, the accuracy management sample rack is conveyed to the cold-storage section303for standby.

Since the accuracy management samples have predetermined data measurements as described above, natural evaporation of these samples during prolonged standby in the analyzer causes changes in the data measurements. For this reason, the cold-storage section303has a cold-storage function to suppress the evaporation of the samples.

After a fixed time of analysis of a general-test sample, upon an arrival at a time preset to measure an accuracy management sample for a particular item, the accuracy management sample rack standing by in the cold-storage section303is conveyed therefrom to the functional module400and the accuracy management sample is analyzed. After the analysis, the rack is reconveyed to the cold-storage section303, in which the rack then waits for a request for measurement of the next accuracy management sample.

The accuracy management sample rack standing by in the cold-storage section303is unloaded therefrom under an operator instruction from the operating unit and then stored into the storage section102of the buffer unit100through the return lane202of the rack conveyance unit200.

Next, total system operation is described below.

FIG. 17is a flowchart showing a method of determining sample rack conveyance routes.

Sample rack conveyance routes are determined upon completion of ID recognition with the rack ID reading unit104and sample ID reading unit106of the sampler unit100, upon the unloading of the sample rack into the module rack-unloading position404of the buffer unit300following completion of processing in the functional module, and upon completion of ID recognition by the ID reader321provided to read the sample rack that has been loaded from the one-rack loader/unloader320.

A system control unit600shown inFIG. 1manages load information on the functional modules that form part of the system, that is, the number of samples and analytical items to undergo processing in each functional module. The system control unit also searches in the above timing for the functional module whose load is the lightest of all module loads. In addition, the system control unit searches for items processable in the functional module. The load here includes processing capabilities of each functional module as well as the number of items to be processed in each functional module, and is based upon, for example, a time up to completion of a preassigned task by the functional module, that is, the time arithmetically derived by multiplying the number of processable items by the time required for execution of the particular process.

The control unit judges whether an extracted functional module can conduct the necessary process for the rack. If the process in the extracted functional module is necessary, this module is determined as a destination to which the rack is to be moved, and the rack is conveyed to the destination.

If, as a result of the module search, a plurality of functional modules identical in load are present and the process for the rack is to be conducted in each of these modules, the functional module nearest to a current position of the rack is determined as the destination thereof.

If the process in the functional module which has been extracted because of the lightest load is unnecessary, the control unit searches for the functional module of the next lowest load, and for items processable in this module, and judges once again whether the necessary process can be conducted for the rack. This sequence is repeated for all functional modules and whether each module can be a destination for the rack.

If none of the functional modules is eventually found to be fit for use as the destination of the rack, the control unit judges whether the rack requires automatic retesting. If automatic retesting is required, the rack is moved to the buffer of the buffer unit and waits for analytical results to be output. After the output of the analytical results, if retesting is necessary, the rack is reconveyed from the buffer to the processing position in the functional module. After being processed, the rack is unloaded from the buffer unit and stored into the storage section of the sampler unit through the return lane of the rack conveyance section. If automatic retesting is unnecessary or if automatic retesting, although it has once been judged to be necessary and the rack has been placed in the buffer for standby, is newly judged from output results not to be necessary, the rack is stored from the buffer unit into the storage section similarly to the above.

Load information on each functional module is updated upon detection of a change in load, that is, upon the determination of a new destination for the sample rack, or upon the unloading thereof into the module rack-unloading position of the buffer unit following an end of the process in the functional module.

Examples of actual sample rack flow are described below.FIGS. 18 and 19are schematic diagrams of a system which includes a sampler unit100, a rack conveyance line200, buffer units300a,300b,300c, functional modules400a,400b,400c, and a supplemental module500.

A case in which a sample rack requires no processing in the functional module400aand the supplemental module500, a load upon the functional module400ais the lightest of all loads upon the functional modules400a,400b,400cand the supplemental module500, and automatic retesting is unnecessary, is described as an example below usingFIG. 18.

In this case, processing items on the sample rack loaded into the sampler unit100are determined from the corresponding rack ID and sample ID information in the same manner as that described above. During the determination, the control unit searches for the functional module with the lightest load, and for items processable in this functional module. The functional module400ais determined as a conveyance destination since the module400ais first extracted on the basis of its load information and since the rack requires processing in the module400a. In accordance with the determination, the sample rack is transferred from a rack loading/unloading position203athrough the feed lane201of the rack conveyance unit200to the buffer unit300a.

At this time, if the functional module400ato which the sample rack has been transferred is ready to immediately process the rack, that is, if an internal buffer403aof the module400ais not full, the rack is conveyed to the module400a. If the functional module400ais not ready for immediate rack processing, the sample rack is conveyed to a buffer302a.

After the sample rack has moved to the buffer unit300a, a conveyance route of the next sample rack loaded from the sampler unit is determined in substantially the same manner as that described above. When the functional module400ais determined as the conveyance destination of the next sample rack for substantially the same reason as the above, if the total number of sample racks present in and between the buffer unit300aand functional module400aor supplemental module500on the conveyance route at that time is less than the number of slots in the buffer302aof the buffer unit300a, the loading of the next sample rack into the buffer unit300ais continued and the sample rack is made to stand by in an empty slot of the buffer302a. If the total number of sample racks is equal to the number of slots in the buffer, the sample rack is made to stand by in the sampler unit until sample rack unloading from the buffer unit300ainto the conveyance unit200has been completed.

When a vacancy occurs in the buffer403aof the module400a, the sample rack that has been made to stand by in the buffer302ais conveyed to functional modules, sequentially processed in each of the modules, and unloaded into a module rack-unloading position404aof the buffer unit300a. At this point of time, the next conveyance route is determined for the rack. If the loads of the functional module400b, the supplemental module500, and the functional module400care lighter in that order, the control unit extracts the functional module400b. However, since the rack requires no processing in400b, the control unit next extracts the supplemental module500whose load is lighter than that of400b. Since the rack requires processing in the supplemental module500, this module is determined as the next conveyance destination.

At this time, if the supplemental module500is ready for immediate rack processing, the rack is conveyed directly to the supplemental module500. If the supplemental module is not ready for immediate processing, the sample rack stands by in the buffer302aand after the supplemental module has become ready, the rack is conveyed to the module.

The rack that has gone through the process in the supplemental module500is unloaded into the rack-unloading position503thereof. This is followed by the next conveyance routing. Since all necessary processing of the rack is already completed, however, the storage section102of the sampler unit100is determined as the next conveyance destination. In accordance with the determination, the buffer unit activates the transfer mechanism to move the sample rack to the rack loading/unloading position204aon the return lane202of the rack conveyance unit200, and then the rack conveyance unit200stores the rack into the storage section.

A case in which a sample rack requires processing in the functional modules400a,400b,400c, the load of the functional module400cis the lightest of all loads upon each functional module and the supplemental module500, and automatic retesting in the functional module400bis necessary, is described as another example below usingFIG. 19.

In accordance with the flowchart ofFIG. 17, the functional module400cwith the lightest load is determined as a first conveyance destination for the sample rack which has been loaded into the sampler unit100. The loaded sample rack is moved to the rack loading/unloading position203c, along the feed lane201of the rack conveyance unit200, and after the rack has undergone processing in the functional module400cvia the buffer unit300c, the next conveyance route is determined at the rack unloading position404cof the module.

If the loads of the functional modules400aand400bat this point of time are the same, the functional module400bnearest to the functional module400cis determined as the next conveyance destination of the sample rack. Therefore, the rack is unloaded into a rack loading/unloading position204con the return lane202of the rack conveyance unit200via the buffer unit300c, then moved to the rack loading/unloading position204bin the buffer unit300bthrough the return lane202, and processed in the functional module400bvia the buffer unit300b. After rack processing, the next conveyance route is determined at the rack-unloading position404bof the module.

If the load of the functional module400ais the lightest of all module loads at this time, the module400ais determined as the conveyance destination for the same reason as described above. The rack is unloaded into the rack loading/unloading position204bon the return lane202of the rack conveyance unit200via the buffer unit300b, then moved to the rack loading/unloading position204ain the buffer unit300athrough the return lane202, and processed in the functional module400avia the buffer unit300a. After rack processing, the next conveyance route is determined at the rack-unloading position404aof the module.

At this time, a conveyance destination is extracted in accordance with the flowchart ofFIG. 17. If, at this time, initial measurement results are already obtained in the functional module400band indicate that retesting is necessary, the functional module400bis determined as the conveyance destination. Conversely if initial measurement results are not obtained and it is unknown whether retesting is necessary, the rack stands by in the buffer302aof the buffer unit300a.

If retesting is necessary, the rack is unloaded into the rack loading/unloading position203aon the feed lane201of the rack conveyance unit200via the buffer unit300a, then moved to the rack loading/unloading position203bin the buffer unit300bthrough the feed lane201, and retested in the functional module400b. The retesting of the rack is followed by the next conveyance routing at the module rack-unloading position404b.

At this time, the next conveyance destination is extracted in accordance with the flowchart ofFIG. 17. Since all processing required for the rack is already completed, the storage section102of the sampler unit100is determined as the next conveyance destination. Therefore, the rack is unloaded into the rack loading/unloading position204bon the return lane202of the rack conveyance unit200through the buffer unit300b, and stored into the storage section102of the sampler unit100through the feed lane202.

Conversely if retesting is not required, the storage section102of the sampler unit100is determined as the conveyance destination of the rack which has been standing by in the buffer302aof the buffer unit300a. After this, the rack is unloaded into the rack loading/unloading position204aon the return lane202of the rack conveyance unit200via the buffer unit300b, and stored into the storage section102of the sampler unit100through the feed lane201.

Next, process flow relating to a loaded emergency-test sample is described below usingFIG. 20. For simplicity, the description assumes that the emergency-test sample requires processing by the functional module400aonly.

The ID of the emergency-test sample rack553which has been loaded into the emergency-test sample loader109of the sampler unit100is read, then the functional module400ais determined as a conveyance destination, and the rack is loaded from the rack loading/unloading position203aof the buffer unit300ainto a rack loading/unloading position301aof the buffer unit300a. Upon recognizing that the emergency-test sample will soon be loaded, the buffer unit300aand the functional module400astart operating to move a general-test sample rack550,551, or552from the conveyance route to the buffer302a. When the conveyance route to the functional module400abecomes useable, the emergency-test sample rack553is immediately conveyed thereto for processing. Upon the conveyance of the emergency-test sample rack553to the functional module400a, the general-test sample rack550,551,552is reconveyed thereto and processing is restarted. The emergency-test sample rack553whose processing has ended is stored into the storage section102in accordance with the flowchart ofFIG. 17.