Optics: measuring and testing – For light transmission or absorption – Of fluent material
Reexamination Certificate
2002-03-06
2003-09-30
Rosenberger, Richard A. (Department: 2877)
Optics: measuring and testing
For light transmission or absorption
Of fluent material
C356S627000, C250S577000
Reexamination Certificate
active
06628395
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method and device for preliminary testing of a serum sample in a sample container. The present invention is particularly useful for establishing a hemolytic index, an icteric index and a lipemic index for a neat serum sample, prior to removing the neat serum sample from the primary collection tube. The present invention is also useful for evaluating whether sufficient serum sample is present in the primary collection tube.
BACKGROUND
The accurate analysis of a serum sample is often instrumental in determining the health of a patient and what measures are necessary to restore the health of the patient. In an effort to reduce laboratory labor costs, many hospitals and laboratories utilize automated clinical analyzers to analyze patient serum samples. Clinical analyzers are presently able to accurately and quickly perform such functions as drug monitoring, specific protein blood analysis and cancer detection on a serum sample.
These clinical analyzers commonly utilize a plurality of cuvettes which are sequentially subjected to a variety of tests during a machine cycle of the clinical analyzer. Typically, during a machine cycle, the testing begins at one location, samples are added at one location and multiple serum samples are sequentially tested.
In some cases, the integrity of the serum sample may affect the interpretation of the results of the clinical analyzer. For example, preanalytical variables in the serum sample, which are not related to the patient disease state, may cause a different interpretation of the condition of the patient. Preanalytical variables include hemolysis (ruptured red blood cells), Icteris (excessive Bilirubin) and Lipemia (high, visible lipid content).
One way to evaluate the integrity of the serum sample is to have a skilled laboratory worker visually inspect the color of the serum sample. A normal serum sample has a light yellow to light amber color. Alternately, a serum sample containing Hemolysis is reddish in color, a sample containing Icteris is dark yellow/brown in color and a sample containing Lipemia is whitish in color. Thus, the degree of red color in a serum sample corresponds to the amount Hemolysis present in the serum sample, the degree of dark yellow/brown color corresponds to the amount of Icteris present in the serum sample and the degree of whitish color corresponds to the amount of Lipemia present in the serum sample.
Typically, a laboratory worker will assign an hemolytic index, an icteric index and a lipemic index to the serum sample based upon the color. Based upon the value of the hemolytic index, the icteric index and the lipemic index, the interpretation of the results from the clinical analyzer can be evaluated. Alternately, if the value of one or more of the hemolytic index, the icteric index and the lipemic index are too high, the serum sample will be discarded without analysis by the clinical analyzer.
However, visual inspection can be labor intensive and costly. Further, the possibility of human error exists with visual inspection, the results of the visual inspection is highly subjective and varies between workers, and one of the variables could mask or hide the other variables. Furthermore, with closed container sampling, bar code labels directly on the container, and automated clinical analyzers, the laboratory worker, in many instances simply does not have an opportunity to visually observe the serum sample. Thus, it is becoming increasing important to evaluate the integrity of the serum sample without the use of visual inspection by a laboratory worker.
One attempt to solve this problem involves optically viewing the serum sample after the serum sample has been transferred to one of the cuvettes of the clinical analyzer. Measuring the optical characteristics of the sample in the clinical analyzer eliminates the need for visual inspection. However, this test utilizes machine time of the clinical analyzer and if the integrity of the serum sample is determined to be compromised, additional machine time and a machine cycle are wasted. Further, this procedure can not be used with clinical analyzers which add reagents to the cuvette prior to adding the serum sample.
Another attempt to solve the problem involves separately testing a portion of the serum sample in a separate cuvette of the clinical analyzer, simultaneously with the other tests being performed on the serum sample by the clinical analyzer. However, this requires the use of a portion of the sample and the clinical analyzer. Therefore, this procedure will waste sample and machine time. Further, with this procedure, if the serum sample is determined to be compromised, a machine cycle and reagents are wasted.
Yet another attempt to solve the problem involves evaluating the serum sample in a probe during the transfer of the serum sample. This device is discussed in detail in U.S. Pat. No. 5,734,468, issued to McNeal, the contents of which are incorporated herein by reference. Unfortunately, because the integrity of the sample is evaluated in the probe, the probe must be washed with a wash fluid to prevent carry-over between serum samples. For large scale operations, the wash fluid poses several problems, including increased costs and increased environmental concerns.
In light of the above, it is an object of the present invention to provide a method and device which evaluates the integrity of a serum sample, without visual inspection by a laboratory worker. Another object of the present invention is to provide a method and device which quickly and accurately determines the presence of Hemolysis, Icteris and Lipemia in a sample, without consuming any sample and without adversely effecting the integrity of the sample. Yet another object of the present invention is to provide a method and device which establishes a hemolytic index, an icteric index and a lipemic index for the serum sample, without wasting machine time of the clinical analyzer and without interrupting the operation of the clinical analyzer. Yet another object of the present invention is to provide a method and device which determines the presence of any interferant in the sample, without consuming the sample. Still another object of the present invention is to provide a method and device which evaluates the integrity of the sample and transfers the sample to an appropriate location based upon the integrity of the sample. Yet another object of the present invention is to provide a device and method for determining the amount of sample in the sample container available for testing with the clinical analyzer.
SUMMARY
The present invention is directed to a method and device for performing preliminary tests on a sample in a sample container which satisfies these objectives. The method includes the steps of (i) providing an optical probe; and (ii) monitoring the sample in the storage container with the optical probe to determine the suitability of the sample for additional testing. The present invention is particularly suited for performing preliminary tests on a neat serum sample in a primary collection tube without removing the neat serum sample from the primary collection tube.
The preliminary tests include a screening test to evaluate the integrity of the sample in the sample container and/or a volume test to measure the amount of sample available for testing. Importantly, with the present invention, the sample is preliminarily tested in the storage container, prior to being removed from the storage container and prior to being transferred to a clinical analyzer. Therefore, machine time of the clinical analyzer is not wasted, the sample is not consumed or altered and the sample can be transferred to an appropriate location, e.g., the clinical analyzer or a waste receptacle, based upon results of the evaluation.
The following terms used in this application shall have the following meaning:
“Neat Serum Sample” shall mean undiluted serum or plasma.
“Primary Collection Tube” shall mean a blood collection tube used to collect blood from a patient. A
Liu Yangang
McNeal Jack
Nguyen Ian
Pfeifer Shirley
Wang Tung Rung
Beckman Coulter Inc.
Hill D. David
May William H.
Rosenberger Richard A.
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