Automatic clinical analyzer

C. Medical Imaging Systems- aca Automatic Clinical Analyzer... 

ACA = automatic clinical analyzer from Du Pont de Nemours... 

Ryder KW, Click MR. The effect of thioradizine on the Automatic Clinical Analyzer serum tricychc antidepressant screen. J Clin Pathol 1986 86 248-9. 

To perform the cortisol assay, one uses a nuxtute of Ab and Cor-Fl, to which is added the serum sample. As the concentration of serum cortisol is Increased, the polarization decreases (Figure 19.66). The polarization values are used to detetmine the cortisol concentration. Similar FPls have been developed for a wide range of low-molecular-weight analytes, including antibiotics, cocaine metabolites, therapeutic drugs, " the immunosuppressant lyclospoiine, and environmental contaminants, to name just a few. Numerous FPls are routinely performed on automatic clinical analyzers. ... 

Following the pioneering work of Bloch, Shatkay, Saroff [452] and Moody, Thomas [137], increasingly more manufacturers fix the electro-active compound in a much more sturdy PVC matrix and thus obtain solid matrix electrodes with such excellent specifications as stability < 1 mV/24 h reproducibility 0.5 mV response time < 30 s operational life time 4-6 months Because of their importance (some automatic clinical analyzers use them), one way of preparation is given. 

Printout paper for DuPont aca automatic clinical analyzer (1969-1979)... 

The most evident characteristic of modern automatic clinical instruments is the digital display of data. Most have illuminated numerical displays an instrument that performs more than one determination simultaneously may have several. For example, a digital flame photometer commonly has two displays for the simultaneous read-out of Na and K, whereas a blood gas analyzer may have three, for pH and for the partial pressures of COa and Oa. 

Mixing and Diluting Mixing and diluting are automatically performed by the ACA discrete clinical analyzer. The sample cup must contain sufficient quantity to accommodate the sample volume plus the dead volume precise cup filling is not required. 

The operator need only load the sample kit and appropriate test pack(s) into a properly prepared ACA discrete clinical analyzer. It automatically advances the pack(s) through the test steps and prints a result(s). See the Instrument Manual of the ACA analyzer for details of mechanical travel of the test pack(s). 

In this case, sodium emission is monitored at a wavelength of 589.6 nm and potassium at a wavelength of 769.9 nm. The intensity of emission is calibrated with appropriate standards for the samples to be analyzed. In this way it is possible to automatically determine 100 values of sodium and potassium for 100 samples/h using modern clinical instruments. Limits of detection are sub-ppm and for serum values 140 mg/m the range of reproducibility is on the order of 2-3%. 

Initially, these systems were designed to address the needs of clinical laboratories, but at present they are used in such diverse areas as industrial process control (process analyzers) or routine determinations of various substances in the air, water, and soil (environmental monitoring). Automatic analyzers can be classified according to the way in which samples are transported and manipulated ... 

The advances in ion exchange analytical methods have also had limited application in some laboratories. Chromatographic and ion exchange methods of purification and identification of trace components in body fluids have occasionally appeared in clinical chemical literature. The development of fraction collectors and even the fully automatic amino acid analyzer are outside the scope of this presentation. 

Quantitative methods for analyzing for large numbers of the individual constituents of body fluids have frequently involved several steps and excessive operator time. As a result, such complex analyses have been relegated to the research laboratory. It would be extremely difficult and expensive for the clinical laboratory to use these methods on a routine basis, even if they could be entirely automated. However, new high-resolution analytical systems that are capable of automatically analyzing for many of the individual constituents of a physiological sample may be useful in the clinical laboratory for such an in-depth analysis. 

The first fully automated instrument for chemical analysis (the Technicon Auto Analyzer ) appeared on the market in 1957. This instrument was designed to fulfill the needs of clinical laboratories, where blood and urine samples are routinely analyzed for a dozen or more chemical species. The number of such analyses demanded by modern medicine is enormous, so it is necessary to keep their cost at a reasonable level. These two considerations motivated the development of analytical. systems that perform several analyses simultaneously with a minimum input of human labor. The use of automatic instruments has spread from clinical laboratories to laboratories for the control of industrial processes and the routine determination of a wide spectrum of species in air, water, soils, and pharmaceutical and... 

Common to all analytical procedures (manual, automatic, etc.) is the initial careful measurement of a volume of fluid (in clinical chemistry usually blood, serum, plasma, or urine) as well as volumes of standardizing solutions the accuracy and precision of this single operation are probably the factors that most affect the reliability of the whole procedure for any particular type of analysis. Several different sorts of error may be introduced at this stage the absolute volume of sample measured for each of a batch of replicate analyses may be incorrect the variation from one member of a batch to another in respect of the volume of sample taken may be outside the limits acceptable for the analysis and, when batches of specimens are analyzed, there may be cross-contamination of one specimen with material remaining in the system from the analysis of another specimen. 

One of the most important fields in which automatic devices can be used successfully is clinical chemistry because of the complexity of the matrix, and because of the number of analyses that must be performed in a very short time. For example, an automatic device is recommended for automation of urea assay to monitor urea in hemodialysis fluids,242 an important measure for human health. The urea analyzer consists of a flow injection system, a signal processing module, and an IBM-compatible PC. The flow system plays a major role in urea assay and can be schematically represented as shown in Figure 7.2. The quality, objectivity, and reliability of the analytical information obtained using this analyzer is good, and the analyzer has the added benefit of making it possible to assay urea without taking blood samples. 

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