The present invention relates to an apparatus for automatically analyzing a patient's biological fluids such as urine, blood serum, plasma, cerebrospinal fluid and the like. More particularly, the present invention relates to a method for automating the processes involved in performing quality control procedures within an automated biochemical analyzer adapted for analyzing biological fluids.
An increasing number of analytical assays related to patient diagnosis and therapy can be performed by automated biochemical analyzers using a sample of a patient's infections, bodily fluids or abscesses. Generally, such biochemical analyzers employ a combination of analyte specific chemical reagents and reaction monitoring means to assay or determine the presence or concentration of a specific substance or analyte within a liquid sample suspected of containing that particular analyte. Patient samples are typically placed in tube-like vials, extracted from the vials, combined with various reagents in special reaction cuvettes, incubated, and analyzed to aid in treatment of the patient. In typical clinical biochemical analyzers, one or more assay reagents are added at separate times to a liquid sample, the sample-reagent solution is mixed and incubated within a reaction cuvette. Analytical measurements using a beam of interrogating radiation interacting with the sample-reagent solution, for example turbidimetric or fluorometric or absorption readings or the like, are made to ascertain end-point or rate values from which the amount of analyte may be determined.
Automated biochemical analyzers are well known and almost universally employ some sort of a calibration curve that relates analyte concentration within a carefully prepared solution having a known analyte concentration against the signal generated by the reaction monitoring means in response to the presence of the analyte. Such solutions are called “calibrators” or “calibration solutions” or “standard solutions” and are contained in tube-like vials closed with a stopper of some sort. It is regular practice within the biochemical analytical industry to establish a full calibration curve for a chemical analyzer by using multiple calibration solutions which have been carefully prepared with known, predetermined varying concentrations of analyte. These calibration solutions are assayed one or more times and the resulting reaction signals are plotted versus their respective known analyte concentrations. A continuous calibration curve is then produced using any of several mathematical techniques chosen to produce an accurate replication of the relationship between a reaction signal and the analyte concentration. The shape of the calibration curve is affected by a complex interaction between reagents, analyte and the analyzer's electromechanical design. Thus, even if the theoretical analyte-reagent reaction is known, it is generally necessary to employ mathematical techniques to obtain an acceptable calibration curve. The range of analyte concentrations used in establishing a full calibration curve is typically chosen to extend below and beyond the range of analyte concentrations expected to be found within biological samples like blood, serum, plasma, urine and the like. Herein, the term “calibration solution” also encompasses so-called “quality control” solutions typically having a zero-level and a high-level of analyte used to confirm proper analyzer operation but not to calibrate same.
Due to increasing pressures on clinical laboratories to reduce cost-per-reportable result, there continues to be a need for improvements in the overall cost performance of automated biochemical analyzers. In particular, the necessity for operator involvement in conducting routine analyzer calibration protocols needs to be minimized in order to reduce overall operating expenses. A positive contributor to minimizing operator involvement is the ability to automatically provide a continuous supply of calibration solutions as required to perform a wide range of analyzer calibration protocols.
Problematically, current procedures employed in the industry for calibrating an analyzer require an operator to retrieve vial containing the requisite calibration solutions from a refrigerated area, open the closed vial or the like, typically by unscrewing a cap or removing a stopper, aspirating a portion of the calibration solution, possibly preparing diluted solutions to provide a range of analyte concentrations, and dispensing some or all of several calibration solutions into a test cuvette. In certain instances, calibration solutions have an undesirably short useful life time during which the solution remains stable and thus are supplied in a more stable powdered form rather than in a less stable liquid form. Prior to being used, a vial containing a powdered or lyophilized calibration solution is opened by an operator, rehydrated using a precise amount of distilled or de-ionized water, the vial is re-closed, shaken to dissolve all lyophilized calibrator before aspirating a portion of the calibration solution. The contents of the test cuvette are then assayed by the analyzer and the results used to either confirm that the analyzer is in proper calibration condition or the results may be used to adjust the analyzer's calibration curves to achieve a proper calibration condition.
The object of the present invention is to provide a random access biochemical analyzer adapted to determine when and which calibration solutions need to be evaluated by the analyzer and to automatically perform calibration and quality control protocols and make adjustments as required to maintain the analyzer in a proper and accurate analyzing condition. A calibration solution vial supply system important to the present invention employs container shuttles adapted to remove calibration solution vials from a loading tray and to inventory said solution vials on board the biochemical analyzer in a calibration solution server. In addition, the analyzer is adapted to automatically penetrate the closure covering the opening of the calibration solution vials, aspirate an amount of solution and dispense said solution into a test cuvette, thereby eliminating the previous need for operator intervention. This system thus provides a random access calibration solution supply system with the flexibility to position a large number of different calibration solution containers at aspiration locations by moving calibration solution vials between a calibration solution vial loading tray, at least one calibration solution vial server, and at least one calibration solution aspiration location.
The invention will be more fully understood from the following detailed description thereof taken in connection with the accompanying drawings which form a part of this application and in which:
Analyzer 10 is controlled by software executed by the computer 15 based on computer programs written in a machine language like that used on the Dimension® clinical chemistry analyzer sold by Dade Behring Inc, of Deerfield, Ill., and widely used by those skilled in the art of computer-based electromechanical control programming. Computer 15 also executes application software programs for performing assays conducted by various analyzing means 17 within analyzer 10.
Temperature-controlled storage areas or servers 26, 27 and 28 inventory a plurality of multi-compartment elongate reagent cartridges 30 like that illustrated in
A key factor in maintaining an optimum assay throughput within analyzer 10 is the ability to timely resupply reagent containers 30 into servers 26, 27 and 28 before the reagents contained therein become exhausted. Similarly important is the ability to timely resupply calibration solutions in vials 30V into server 26 before the solutions contained therein become exhausted so that calibration and control procedures may be conducted as required, whether this be based on the basis of time between calibrations or number of assays performed since an immediately previous calibration or number of assay results outside normal ranges, or changes in the performance of the analyzer. This challenge may be met by timely equipping analyzer 10 with additional requisite calibration solutions used in calibration and control procedures before they become exhausted, thereby maintaining assay throughput of analyzer 10 uninterrupted.
In order to maintain continuity of assay throughput, and as taught by the present invention, computer 15 is programmed to track reagent and assay chemical solution consumption along with time, and date of consumption of all reagents consumed out of each reagent container 30 and calibration solutions consumed out of each vial container 30A on a per reagent container, per calibration vial container, per quality control container, per assay, and per calibration basis, for specifically defined time periods. Using this consumption data, time, and current inventory data of already on-board reagent containers 30 and calibration vials 30V within storage areas 26, computer 15 is programmed to make an inventory demand analysis for specifically defined time periods so as to determine future assay inventory demands for the specifically defined time periods and display or issue to an operator a list of all of the reagent containers 30 and calibration vials 30V that will be needed in the future in a timely manner prior to the actual need of said reagent container 30 and calibration vials 30V. In some instances, reagents in reagent container 30 must be hydrated or diluted prior to use and such a time factor must also be included in the inventory demand analysis. Addition of said reagent containers 30 and calibration vial carriers 30A by an operator insures sufficient reagent and calibration solution supply to continuously meet future needs of analyzer 10 so that analyzer 10 is maintained in proper operating condition.
It should be appreciated by the reader that making a calibration solution inventory demand analysis for specifically defined time periods, as opposed to using an inventory demand analysis averaged over specifically defined time periods, is a key factor in practicing the present invention. What has been discovered is that the assay demand load pattern and thus the demand pattern for routine calibration and quality control protocols, for example on a Monday, may be very different from the demand pattern, for example on a Thursday. Further, it has been discovered that the demand load pattern, for example on a given day of the week, is most likely going to be very similar to the demand load pattern on the previous several same day of the week. The basis for a specifically defined demand pattern is due to several factors among which are a range of social practices, for example, sporting events typically being on weekends and/or increased social events at holidays and the like. In addition, for reasons of efficiency, some clinical laboratories schedule select assays, for example, PSA tests, on a certain day near middle of the week, and some out-patient tests, for example glucose, are scheduled earlier in the week. Finally, certain surgeons schedule select types of surgery early in the week and other types of surgery near the end of the week, resulting in different daily patterns of pre-operation patient assays. Further contributing to the demand pattern is the fact that different laboratories have different assay demand patterns, depending, for example, upon whether the laboratory serves an urban community where trauma is more likely than in a rural community, upon whether the laboratory serves a medical research university, upon whether the laboratory serves a specialized hospital like a pediatric hospital, and the like.
On a regular basis, for example daily, as taught by the present invention, the calibration and quality control solution consumption data is also transmitted to an external computer system located within a Laboratory Information System (LIS) or Hospital Information System (HIS) or to a Manufacturer Information System (MIS) remotely at the manufacturer of calibration and quality control vials 30A. The external computer systems use the consumption data to determine the need for re-order of vials 30V in a timely manner so as to ensure that the calibration solutions in vials 30V are available in local inventory for future use. In a preferred embodiment of the present invention, the vial 30V consumption data are used by the manufacturer of calibration vials 30V and compared to the manufacture's shipment data to determine re-order quantities. The manufacturer automatically ships additional calibration vials 30V to the location of analyzer 10 as needed to ensure a continuous supply at that location.
A bi-directional incoming and outgoing sample tube transport system 34 having input lane 36A and output lane 36B shown as open arrows transports incoming individual sample tubes 40 containing liquid specimens to be tested and mounted in sample tube racks 42 beneath a liquid sampling aliquotter 38 using a magnetic drive system like described in U.S. Pat. No. 6,571,934 assigned to the assignee of the present invention. Liquid specimens contained in sample tubes 40 are identified by reading bar coded indicia placed thereon using a conventional bar code reader to determine, among other items, a patient's identity, the tests to be performed, if a sample aliquot is to be retained within analyzer 10 and if so, for what period of time. It is also common practice to place bar coded indicia on sample tube racks 42 and employ a large number of bar code readers installed throughout analyzer 10 to ascertain, control and track the location of sample tubes 40 and racks 42.
After a volume of sample fluid is aspirated from all sample fluid tubes 40 on a rack 42 and dispensed into aliquot vessels 44V by sampling aliquotter 38, a rack 42 may be held in a buffer zone until a successful assay result is obtained. Regardless of whether sample fluid racks 42 are held in the sampling zone or buffer zone, shuttle mechanism 43 associated with the buffer zone positions the sample fluid rack 42 onto output lane 36B. Output lane 36B, taken with the magnetic drive system, moves racks 42 containing sample fluid tubes 40 toward the end of the output lane 36B to a frontal area of analyzer 10 which is readily accessible to an operator so that racks 42 may be conveniently unloaded from analyzer 10.
Liquid specimens contained in sample fluid tubes 40 are identified by reading bar coded indicia placed thereon using a conventional bar code reader to determine, among other items, a patient's identity, the tests to be performed, if a sample fluid aliquot is to be retained within analyzer 10 and if so, for what period of time. It is also common practice to place bar coded indicia on sample fluid tube racks 42 and employ a large number of bar code readers installed throughout analyzer 10 to ascertain, control and track the location of sample fluid tubes 40 and sample fluid tube racks 42.
Aliquot vessel array transport system 50 seen in
A number of aspiration and dispense arms 60, 61 and 62 comprising conventional liquid probes, 60P, 61P and 62P, respectively, are independently mounted and translatable between servers 26, 27 and 28, respectively and outer cuvette carousel 14. Probes 60P, 61P and 62P comprise conventional mechanisms for aspirating reagents required to conduct specified assays at a reagenting location from wells 32 in an appropriate reagent cartridge 30, the probes 60P, 61P and 62P subsequently being shuttled to a dispensing location where reagent are dispensed into cuvettes 24 contained in cuvette ports 20 in outer cuvette carousel 14. A number of reagent cartridges 30 are inventoried in controlled environmental conditions inside servers 26, 27 and 28. In like manner, a number of calibration solution vials 30V are inventoried in controlled environmental conditions inside server 26, and may be accessed by aspiration and dispense arm 60 as required to conduct calibration and quality control protocols as required to maintain analyzer 10 in proper operating condition. A key factor in maintaining high assay throughput of analyzer 10 is the capability to inventory a large variety of vials 30V having the requisite calibration and control solutions to perform a large number of calibration and quality control protocols inside reagent storage area 26A and 26B and to then quickly transfer random ones of these vials to aspiration and dispense locations for access by probe 60P.
Reagent container shuttles 27S and 28S in
Aspiration and dispense arm 60 and probe 60P useful in performing the present invention may be seen in
From this description, it is clear to one skilled in the art that the capabilities of shuttle 72 to move vial carriers 30A between loading tray 29 and servers 26A and 26B, taken in combination with the capabilities of carousels 26A and 26B to place any vial carrier 30A beneath aspiration arm 60, and the capabilities of aspiration and dispense arm 60 and probe 60P to access liquid solutions from closed vials 30V provide a random access vial carrier 30A supply system with the flexibility to deliver a large number of different calibration solutions into cuvettes 24 as needed to automatically perform calibration protocols and make adjustments as required to maintain the analyzer in a proper and accurate analyzing condition without need for operator intervention.
It should be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention.
Accordingly, while the present invention has been described herein in detail in relation to specific embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.