History of Automation 1957 – Technicon develops the first automated analyzer Continuous flow Issues: carryover and costly 1970 – Dr Anderson(NASA) develops a centrifugal analyzer – DuPont ACA revolutionized chemistry with a non-continuous flow, discrete analyzer with random access availability – Kodak Ektachem: dry slide technology Small volumes of sample Reagents on slides for dry chemistry analysis 1980-Present Discrete analyzer take over Chemistry “walk-away” capabilities
Ektachem & ACA
Drivers For Technology Advances Reduction in TAT’s Staff shortages Economic factors Increase throughput Reduction in lab error Increase safety 24/7 operations Focus on automation of tasks rather than manual methods
5 Automated Chemistry Analyzers Advantages – Increased number of tests/technologist each tech can perform more tests during a period of time – Minimizes variations in results eliminates errors in pipetting, calculations – Small sample size and reagent volumes
6 Automated Chemistry Analyzers Disadvantages – Methods vary with the instrument type, etc. – Generally, cost of equipment, maintenance, amount of QC – Techs must be kept knowledgeable & careful in set-up and operations
Basic Types of Instruments Continuous flow Centrifugal analysis Discrete analysis Batch analyzer – perform only test that is requested – can perform many combinations of tests – do not consume reagents for tests not ordered – Continuous flow, centrifugal and discrete analyzers can all use batch mode
Automated Chemistry Instruments Continuous flow analysis – Reagents are pumped continuously through the system. – Samples are introduced sequentially at timed intervals and follow each other through the same network of tubing coils, heating baths and photometer / other detector. – While economical for profiles of tests, not good for stats or single order tests. – All samples get all tests, ordered or not – Could not easily interrupt the process once initiated. – *Also prone to “carryover”. – Wasteful of reagents – Example: Chem 1 By Technicon 8
9 Automated Chemistry Instruments Centrifugal analysis – A discrete system where the transfer of solutions is carried out by the use of centrifugal force – Runs multiple samples, one test at a time – Example: Cobas-Bio and IL Monarch
Automated Chemistry Instruments Discrete analysis Each sample is contained in a separate reaction vessel Make up the majority of modern chemistry analyzers Run multiple tests one sample at a time or multiple samples one test at a time called RANDOM sampling Examples: Dade Behring Dimension RXL Kodak Ektachem Alfa Wasserman Ace Alera 10
11 Automated Chemistry Systems Wet chemistry systems – Reagents come ready to use or lyophilized and must be reconstituted – Systems include batch and profile analyzers or stat analyzers Examples: Beckman Coulter CX-7, Vitros, Dade, Advia, Roche Integra, Hitachi, Alfa Wasserman Ace Aleria, etc.
12 Automated Chemistry Systems Dry reagent systems Reagents can be tablets or found on cellulose fibers located on strips, cards, or layered on film. Reagents easy to handle, store well, and have fairly long shelf life. Examples: Vitros, Seralyzer, Kodak Ektachem, ChemPro, Dupont Analyst
13 Automated Chemistry Analyzers Concepts and definitions
14 Automated Chemistry: Terms – Throughput – Max # samples that can be processed in 1 hour – Dwell time – minimum amount of time required to get test result after sampling varies greatly with instrument can be important consideration when selecting instrument
15 Automated Chemistry:Terms Stat testing – Latin statum = immediate – a widely used (abused) word in the lab, used to prioritize work – Stat turn around time - within 1 hour after order entry
16 Costing of chemistry lab tests Things that are included in pricing – labor – processing – equipment maintenance – reagents - including a portion of start-up – calibration and QC – consumables - containers, paper – capital - proportionate amt of life of instrument – hospital overhead - facility maintenance
17 Automated Chemistry Test repertoire – What tests the instrument is capable of doing Consider cost analysis – Immediate test repertoire What it can do without any changes (set- up or programmed for) – Total test repertoire Total number of tests that can be performed on the instrument, with a few changes, ie. reagents, filters or components.
Preanalytic Phase Specimen collection – Right tube for right tests – Proper patient label – Correct draw site Specimen transport – Phlebotomists – Volunteers – Pneumatic-tube systems
Analytic Phase Sample handling – Important to check the specimen for hemolysis, lipemia, clots or fibrin – Some analyzers use closed-tube,some open-tube – Most instruments utilize a level-sensing probe to detect the amount of serum or plasma in a tube
Summary of Analyzer Operations 1.Sample identification: bar code or manual read 2.Determination of tests to be performed: LIS can communicate this or operator 3.Reagent systems and delivery: reagents dispensed into cuvet 4.Specimen measurement and delivery: sample aliquot in introduced into reaction cuvet 5.Chemical reaction phase: Sample and reagents mixed and incubated 6.Measurement phase: Optical readings 7.Signal processing and data handling: Concentration is estimated from a calibration curve stored in analyzer 8.Send results to LIS or read and entered off results tape
Postanalytical Phase Bidirectional communication Decreases opportunity for error Auto-verification
Trends Total Laboratory Automation (TLA) – Integrated work cells Specimen manager Track system Immunoassay Chemistry
References Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry: Techniques, principles, Correlations. Baltimore: Wolters Kluwer Lippincott Williams & Wilkins Sunheimer, R., & Graves, L. (2010). Clinical Laboratory Chemistry. Upper Saddle River: Pearson.