CC LAB: AUTOMATION

Cards (20)

  • Definition of Terms:
    • Automation: The process where an analytical instrument performs many tests with minimal involvement of an analyst
    • Batch analysis: Type of analysis where many specimens are grouped in the same analytical session
    • Carry-over: The transport of analyte or reagent from one specimen reaction into and contaminating a subsequent one
    • Continuous-flow analysis: Type of analysis where each specimen in a batch passes through the same continuous stream at the same rate
    • Discrete analysis: Type of analysis where the sample is aspirated into the sample probe and then delivered into a reaction cup
    • Dwell time: Minimum time from initial sampling to the production of a result
    • Multiple-channel analysis: Type of analysis where each specimen is subjected to multiple analytical processes
    • Parallel analysis: Type of analysis where all specimens are subjected to a series of analytical processes at the same time
    • Random-access analysis: Configuration of an automated analyzer where analyses are performed on a collection of specimens sequentially
    • Sequential analysis: Type of analysis where each specimen in a batch enters the analytical process one after another
    • Single-channel analysis: Type of analysis where each specimen is subjected to a single process
    • Throughput: The number of specimens processed by an analyzer during a given period of time
    • Workstation: A clinical laboratory workstation dedicated to a defined task
  • Automation:
    • Enables laboratories to process larger workloads without comparable increases in staff
    • Used for test performance, processing and transport of specimens, loading of specimens into automated analyzers, and assessing test results
  • History of Automation:
    • First automated analyzer was the "Autoanalyzer" by Technicon in 1957
    • First commercial centrifugal analyzer was a spin-off technology from NASA outer space research in 1970
    • Automatic Clinical Analyzer (ACA) by DuPont (now Siemens) in 1970 was the first non-continuous flow, discrete analyzer with random-access capabilities
    • Kodak Ektachem (now Vitros) Analyzer in 1978 was the first to use microsample volumes and reagents on slides for dry chemistry analysis
  • Basic Concepts and Approaches to Automation:
    • Advantages of automation include decreased human factor, increased test performance, minimized variation in results, and accuracy not dependent on operator skill
    • Eliminates potential errors of manual analyses and uses small amounts of reagents and samples
  • Automated System Designs:
    • Total Laboratory Automation employs an integrated track system linking all workstations together
    • Modular Integrated Systems link multiple laboratory disciplines into a single testing platform
    • Stand-alone systems automate specific sections of the process that are still manual operations
  • Classification of Automated Analyzers:
    • Continuous Flow Analyzer: Samples flow through a common reaction vessel, significant carryover problems
    • Discrete Analyzer: Samples travel through the instrument in its own reaction vessel, each test reaction takes place in a separate compartment
    • Centrifugal Analyzer: Developed from space-aged technology, samples and reagents mixed together and flowed by centrifugal force into separate cuvettes
  • Centrifugal analyzers:
    • Samples and reagents mixed together, reacted, and flowed by centrifugal force into separate cuvettes for spectrophotometric analysis
    • Only one test type can be performed each time
  • Sequential:
    • Performing a set of test reactions in a particular order on each sample in the order received
  • Batch:
    • All samples loaded at the same time, and a single test conducted on each sample
  • Parallel:
    • More than one test analyzed concurrently on a given clinical system
  • Random access:
    • Any test can be performed on any sample in any sequence
  • Automated analysis technologies:
    • Bar coding
    • Optical character recognition
    • Voice identification
    • Radio frequency identification
    • Touch screens
    • Light pens
    • Hand print tablets
    • Optical mark readers
    • Smart cards
    • Automated specimen inspection to identify sample identification errors and sample integrity issues
  • Specimen preparation and identification:
    • Preparation of the sample for analysis is a manual process in most laboratories
    • Alternatives include the use of robotics or front-end automation, bypassing specimen preparation by using whole blood for analysis, and using barcode-labeled tubes
  • Specimen loading and aspiration:
    • Circular carousels or rectangular racks as specimen containers
    • Instrument determines the slot number containing the last sample and terminates the analysis after that sample
    • Tubes are typically decapped before sampling
    • Common problem: Carryover
    • Loading zone: area where specimens are held inside the instrument before analysis
  • Reagent systems and delivery:
    • Open-system analyzer allows operator to change analysis parameters and use reagents from various suppliers
    • Liquid reagents for open systems are less expensive than closed analyzers
    • Techniques of preservation include refrigeration, dried tablet form, or combining stable components at the moment of reaction
    • Reagent delivery techniques include syringes, piston-driven pumps, and pressurized reagent bottles connected to dispensing valves
  • Chemical reaction phase:
    • Mixing methods include forceful dispensing, magnetic stirring, vigorous lateral displacement, rotating paddle, and ultrasonic energy
    • Separation involves a high reagent-to-sample ratio and short reaction time
    • Incubation maintains required temperature and provides delay for color development
    • Measurement phase methods include UV light, fluorescent, flame photometry, ion-selective electrodes, gamma counters, and luminometers
  • Signal processing and data handling:
    • Accurate calibration is essential for reliable results
    • Proper use of standards reflects data on a standard curve for interpreting sample results
    • Instruments' computer goes into data acquisition and calculation mode after calibration
    • Signal processing may involve signal averaging with hundreds of data pulses per second
  • Future trends in automation:
    • Automation will continue to evolve with system integration and miniaturization
    • Automated analyzers may have artificial intelligence for decision-making
    • Spectral mapping and multiple wavelength monitoring will become standard with high-resolution photometers and polychromators