The present invention relates to an apparatus for automatically processing a patient's biological fluids such as urine, blood serum, plasma, cerebrospinal fluid and the like. More particularly, the present invention relates to a stopper closure for calibration vials involved in performing quality control procedures within an automated biochemical analyzer adapted for analyzing biological fluids.
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 vial-like containers 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 or calibrators which have been carefully prepared with known, predetermined concentrations of analyte. These calibration or standard solutions are assayed one or more times and the mean 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.
Problematically, certain calibration solutions employed in the industry 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 placed on an analyzer, 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 powdered calibrator and placed on the analyzer. 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.
In order that calibration solutions, whether originally supplied in liquid form or in powdered form and rehydrated, be securely contained during shipping and handling, calibration vials are typically closed using a screw threaded plastic or hard rubber cap with an open hole in the center portion and an elastomeric stopper filling the hole. When it is desired to extract a portion of the solution from the vial, the solution is extracted by an operator using, for example, a syringe with a sharpened probe suited to penetrate the stopper. Similarly, if the calibration solutions are inventoried on-board the analyzer in a controlled environment, like described in co-pending U.S. patent Ser. No. 10/123,456 assigned to the assignee of the present invention, an automated probe may be used to extract a portion of the solution from the vial as part of automated calibration and quality control protocols.
In the instance that a vial containing a lyophilized calibration solution is opened by an operator, and rehydrated, it is possible that the vial may be accidentally or improperly closed using only the elastomeric stopper and placed on the analyze without securing the stopper in the vial by screwing the cap onto threads' on the vial. During running of the analyzer, or when the stopper is penetrated by an automated probe, such an elastomeric stopper may be dislodged and fall into the analyzer presenting a hazard to continued operation. Alternately, the stopper may stick onto the probe and prevent a next scheduled aspiration or probe cleaning causing analyzer operation to be disrupted.
It may seem that such a hazard could be eliminated using an integrated stopper and plastic screw cap. However lyophilized calibration solutions are produced in a freeze-drying operation in which an original liquid calibration solution in an open vial is exposed to high vacuum and the vial must be closed while still under vacuum. This is most efficiently done using a vertical downwards motion to simultaneously insert a large number of stoppers into an array of lyophilization vials. If the stopper were integrated with the cap, a more complex and costly rotary motion would be required to screw the caps onto the vials in order to close the vials with the stopper.
The principal object of the invention is to provide a re-sealing puncturable stopper-for use with capped vials having lyophilized calibration chemicals therein. The stopper of the present invention is adapted for use in a manner that minimizes failure modes: (1) in an initial lyophilization manufacturing process; (2) by a user in a subsequent hydration process; (3) protecting a vial stored on-board an automated clinical analyzer; (4) being punctured for aspiration; and, (5) re-sealing the vial after aspiration. An opened section in the stopper's lower portion allows the stopper to be partly inserted into the upper portion of the vial so that the vial's original liquid contents may be exposed to vacuum during a lyophilization operation. After the lyophilization process is completed, the vial may be closed in a multiple-vial closing operation simply by vertically pushing downwards on an array of stoppers until they are fully inserted into the vials. Subsequent to closing the vials, conventional threaded caps may be attached to the vials by placing an open hole in the cap over a sloped top portion of the stopper and twisting the cap over the stopper until the cap slips into a groove in the stopper, thereby securing the cap and stopper combination. Prior to the lyophilized calibration solution being used on an analyzer, an operator unscrews the cap-stopper combination, hydrates the chemicals as required, replaces the cap-stopper combination and places the calibration vial on-board the analyzer. The open hole in the cap exposes a central portion of the stopper which an aspiration probe can puncture during an aspiration process. The stopper is made of an elastomeric material that reseals the puncture to protect the contents of the vial while it remains stored in inventory upon the analyzer. An important feature of the cap-stopper combination is the securing groove that effectively integrates the cap and stopper together so that operational errors arising from the failure to properly replace and secure a stopper onto a calibration vial after hydration are minimized.
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 store 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 supply calibration and quality control solutions in vials 30V 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 and quality control solutions used in calibration and control procedures, thereby maintaining assay throughput of analyzer 10 uninterrupted.
It is known in the industry that the so-called shelf-life of certain calibration and control chemical solutions, shelf-life being the length of time a chemical solution may be stored in a controlled environment and retain its chemical properties within its specified useful range, is too short for the solution to be stored in liquid form. For example, the chemical properties of a solution may drift outside its specified useful range in less than one month while that normal manufacturing inventory and delivery times exceed one month. One approach commonly taken in such instances is to freeze-dry or lyophilize the calibration solution; this however introduces the necessity for an operator to hydrate the lyophilized solution. Regardless of how carefully this is done by an operator, human errors will ultimately occur and some of these may have very adverse effects.
Typically, the cap used during a manufacturing process to close a calibration solution vial 30V after the solution therein is lyophilized is not integral with the stopper used by an operator to close that same calibration solution vial 30V after hydration of the lyophilized calibration solution therein. For example, a closed cap is normally used. For reasons of manufacturing efficiencies, simultaneous closing of large numbers of lyophilized calibration solution vials is desired and this usually leads to a crimping or stoppering closing process as opposed to a threaded-cap-like closing process. In contrast, for operator convenience, a threaded-cap-like threading process is generally preferred to securely close a calibration solution vial 30V after hydration. In addition, after hydration, a puncturable cover is preferably used to close calibration solution vial 30V in order to facilitate aspiration of the calibration solution by a device like probe 54P. As indicated earlier, it is important that the cap and stopper be secured together so that operational errors arising from the failure to properly replace and secure a stopper onto a calibration vial after hydration are minimized.
The present invention addresses these multiple needs by providing a re-sealing puncturable stopper associated with a cap adapted so that the stopper and cap may be used in combination in an initial lyophilization manufacturing process, by a user in a subsequent hydration process, stored safely on-board an automated clinical analyzer, and punctured for aspiration in a manner that minimizes failure modes.
Groove 76 is essentially formed between ridge 74 and a flattened dome-shaped top 78, the dome-shaped top 78 having a flat 79 in its uppermost portion to facilitate closing after lyophilization is completed in an original manufacturing process. As described later in reference to
As explained previously, stopper 70 is adapted for use in a manner that minimizes operation failure modes: (1) in an initial lyophilization manufacturing process; (2) by a user in a subsequent hydration process; (3) protecting contents of vial 30V stored on-board analyzer 10; (4) being punctured for aspiration; and, (5) re-sealing vial 30V after aspiration. Opening 82 in stopper 70's cylindrical lower trunk section 72 allows stopper 70 to be partly inserted into vial 30V so that the vial 30V's original liquid contents may be exposed to vacuum during a lyophilization operation. After the lyophilization process is completed, vial 30V may be closed. in an efficient manufacturing multiple-vial closing operation simply by vertically pushing downwards on an array of stoppers 70 until they are fully inserted into vials 30V. Subsequent to closing vials 30V, conventional threaded caps 84 may be attached to vials 30V by placing cap 84 with open hole 86 in cap 84 over dome-shaped top 78 of stopper 70 and twisting cap 84 over stopper 70 until the top portion 78 of stopper 70 squeezes through hole 86 and then expands to its original shape, so that cap 84 slips into groove 76, thereby securing cap 84 and stopper 70 together in combination. Prior to the lyophilized calibration solution being used on analyzer 10, an operator unscrews the cap 84 and stopper 70 combination, hydrates the chemicals as required, replaces the cap 84 and stopper 70 combination, mixes as required, and places calibration vial 30V on-board analyzer 10. The open hole 86 in cap 84 exposes a central portion of stopper 70 through which an aspiration probe can puncture during an aspiration process. Stopper 70 is made of an elastomeric material that reseals the puncture to protect the contents of vial 30V while it remains stored in inventory upon analyzer 10. A key feature of the cap 84 and stopper 70 combination is the securing groove 76 that effectively integrates cap 84 and stopper 70 together so that operator errors arising from the failure to properly replace and secure stopper 70 onto calibration vial 30V after hydration are minimized.
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.