The AutoAnalyzer continuous flow, batch analysis paradigm was displaced by discrete systems using positive-displacement pipettes, with various volumes possible, or fixed volume, for sample processing and reagent dispensing, with some kind of washing step in between sample dispensing to avoid carryover contamination. Mixing is performed by forceful dispensing, magnetic stirring, or mechanical stirring (rods or piezo-electric mixers). Temperature is controlled by waterbaths, heating blocks, or heated air compartments (air bath). Cuvettes are glass or plastic; the glass cuvettes intended to be permanent and the plastic cuvettes made to be disposable after a single use or after extended use with replacement after a set number of tests.11 Most discrete analysers use individual cuvettes, although some may use a type of flow cell. Various types of detectors are used, with a variety of lamp types (tungsten, quartz halogen, mercury, xenon, and lasers). The monochromators use interference filters, prisms, or diffraction gratings.11 The analytical signal is typically detected using photodiode arrays, allowing a wide variety of wavelengths to be monitored.

Love Systems Routines Manual, Volume 2

The first step towards TLA is to conduct a thorough, detailed analysis of the current laboratory processes, i.e. a workflow analysis. It will demonstrate the strengths and weaknesses of the current system, whether it be manual, semi-automated, or automated, and identify the steps that can be eliminated or improved by TLA. The old saw is true: applying automation to the current, suboptimal process only serves to automate a poor process.12 Moving from multiple automated systems to TLA is a big, complicated, and expensive step for a laboratory. Hawker very appropriately notes that failure to properly analyse the needs of the laboratory and understand the current state and processes in the laboratory are the primary reasons why automation projects are not successful, or at least do not live up to the initial expectations of the adapters.16 The workflow analysis completely maps the current processes from specimen receipt, testing, reporting, and storage/disposal of specimens. Hawker lists ten reasons why automation can fail to deliver on its promise: incomplete understanding of the current non-automated process; lack of flexibility due to fixed processes and limited throughput; unrealistic expectations; poorly executed workarounds to interface automated and manual processes; unclear expectations of system functionality; unnecessarily complicated designs; inadequate technical support; failure to conduct realistic impact analysis; hidden costs (labour, supplies, maintenance); and failure to optimise the current processes prior to automation (never automate a poor process). As a rule-of-thumb, a good TLA system should handle at least 80% of the workload.

The era of automation arrived with the introduction of the AutoAnalyzer using continuous flow analysis and the Robot Chemist that automated the traditional manual analytical steps. Successive generations of stand-alone analysers increased analytical speed, offered the ability to test high volumes of patient specimens, and provided large assay menus. A dichotomy developed, with a group of analysers devoted to performing routine clinical chemistry tests and another group dedicated to performing immunoassays using a variety of methodologies. Development of integrated systems greatly improved the analytical phase of clinical laboratory testing and further automation was developed for pre-analytical procedures, such as sample identification, sorting, and centrifugation, and post-analytical procedures, such as specimen storage and archiving. All phases of testing were ultimately combined in total laboratory automation (TLA) through which all modules involved are physically linked by some kind of track system, moving samples through the process from beginning-to-end. A newer and very powerful, analytical methodology is liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). LC-MS/MS has been automated but a future automation challenge will be to incorporate LC-MS/MS into TLA configurations. Another important facet of automation is informatics, including middleware, which interfaces the analyser software to a laboratory information systems (LIS) and/or hospital information systems (HIS). This software includes control of the overall operation of a TLA configuration and combines analytical results with patient demographic information to provide additional clinically useful information. This review describes automation relevant to clinical chemistry, but it must be recognised that automation applies to other specialties in the laboratory, e.g. haematology, urinalysis, microbiology. It is a given that automation will continue to evolve in the clinical laboratory, limited only by the imagination and ingenuity of laboratory scientists.

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