Pre-Analytical Laboratory Automation

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Maintaining quality and efficiency during specimen sorting, accessioning and delivery

Laboratory automation is now considered required technology in all clinical laboratories in order to maintain quality and efficiency while competing for scarce resources in hospital budgets.  In order to deal with increasing workloads with fewer trained technologists, pre-analytical automation has been developed to assist with specimen sorting, accessioning, and delivery from the accessioning area to the analytical stations in the laboratory.   There is additional motivation for the use of automation since over half of all laboratory errors occur in the pre-analytical phase.

In the planning for the implementation of pre-analytical automation, the physical layout of the automated accessioning area (or areas) should be determined since space constraints can have a profound impact on the choice of technologies.  The ideal pre-analytical space should be linear with the delivery door at one end and the analytical laboratory instruments at the other.

A long narrow room can help establish a lean linear flow so that specimens are not handled more than once and to increase the efficiency of moving specimens into analysis.   Various sample transportation systems should be considered. Laboratories with limited resources or smaller test volumes should consider a simple conveyor belt (e.g. Flexlink) placed in the accessioning area to move specimens from the drop off point and make them easily accessible to a row of seated accessioners.  Specimens may be laid directly on the belt, or transported in boxes (“pallets”) that keep all of one patient’s  specimens grouped together. More sophisticated sample conveyors include air cushion pallets and magnetically levitated pallets.

Beyond, the accessioning area automation is available in two general configurations, workcells and systems. By definition a workcell performs a limited number of tasks and is operated as a standalone device (e.g. tube sorting). Workcells are often designed to be combined into a system that performs a series of steps both sequentially and in parallel, depending on the design. Adopting workcells as needs arise and then combining them into a system is an ideal way to minimize up-front costs and risk. Pre-analytical systems will provide a wide range of pre-analytical tasks and are often provided as part of a total laboratory automation package.

Information Systems

Automation is only as efficient as the information system to which it is linked. There is a growing appreciation that specimens should be barcoded before or during the phlebotomy process so that specimen information can direct the automation to perform the appropriate tasks.  There are several approaches to sorting specimens, but a specimen must be barcoded before it can be automatically sorted.

Some systems will rapidly select one specimen at a time from a bin of randomly oriented specimens, read their bar codes, and then sort them into take-out bins. Other systems will organize them into racks according to their destination (e.g. m-u-t America, Automated Sorter). Other systems will not only rack the specimens after the accessioning bar-code reading process, but also use an automated centrifuge to process specimens that require separation and make the appropriate number of labeled aliquots (e.g. Sarstedt, PVS system).

Various pre-analytical automation systems are considered islands of automation and require manual transportation of the sorted racks to the analytical sections of the laboratory. This intra or inter-laboratory transfer can be facilitated by the use of mobile robotics. Mobile robots are not limited to use just within the laboratory since they can use their coded map of the facility to drive themselves from their starting point to their destination while electronically triggering door openings along the way. However, automated drop off or pick up of the transported material from the mobile robot has yet to become popular despite the 20% increase in efficiency gained by automating this step.

The principal delay in returning laboratory results to the physician is the wait times between specimen processing and analysis.  Currently, available laboratory automation systems provide optimal integration of conveyor belt transportation and analytical instruments for the bulk of routine laboratory tests (e.g. Abbott, Aim Lab, Beckman, Labotix, Ortho, Roche, Sarstedt, Siemens, and Yaskawa).

Over 80% of hematology and routine chemistry test volume can now be analyzed completely by automation. However, there remains the need for automation development in the areas of infectious disease and molecular diagnostics. In the relatively near future and increasing amount of infectious disease testing will be performed by molecular methods (i.e. DNA and RNA sequence analysis). This increasing burden on the molecular laboratory has stimulated the development of automated molecular workcells  that perform both DNA and RNA  extraction and analytics (e.g. Cepheid and Roche for vendor supplied tests; BD MAX for both vendor supplied and customer developed tests).

As medical systems adopt wellness models for healthcare delivery there will be increased focus on predictive and preventative testing that will result in broadening testing menus and increased testing volumes. This increase in wellness diagnostics will put a significant burden on the laboratory and motivate greater amounts of automation. Clearly, customers will be increasingly interested in adaptive and intelligent systems that allow laboratory efficiency to keep up with demand.

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About Author

Robin A. Felder, PhD

Robin A. Felder is professor of pathology; associate director, clinical chemistry, The University of Virginia Department of Pathology, Charlottesville, VA.

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