Vol. 24 • Issue 4
• Page 6
(Editor's note: This is part 1 of a special "Tools for the Technologist" series. Part 2, to address molecular diagnostics, will appear in the May issue.)
Laboratory automation is a mature technology, with installations in more than 2,000 labs worldwide. Recent attention, however, has turned to the remaining labor-intensive and error-prone steps. Newer offerings in laboratory automation include specimen tracking, accessioning streamlining, rapid sorting and mobile robot delivery.
While total laboratory automation (TLA) has been providing large laboratories (1 million specimens a year or greater) clear benefits with increased throughput, reduced Stat testing, reduced errors and more efficient use of laboratory staff, smaller facilities now have more automation choices. Options span from task targeted devices to systems that fully automate many complex sample preparation and analysis tasks.
Outside the Core
However, some steps in the process have not evolved as rapidly as the central core analytical systems. For example, radio frequency identification tags (RFID) and bar codes track specimens from phlebotomy to analysis. A chain of custody system virtually eliminates the potential for specimen misidentification and loss. Physicians benefit from this technology by knowing where their specimen is in the analytical process, much like tracking your Federal Express package right up to your front door. Further, real-time tracking of delivery personnel and vehicles allows optimal specimen management in hub-and-spoke lab systems for regional hospitals.
Meeting TAT Demands
Ideally, turnaround time (TAT) for non-Stat testing in laboratories should be less than 1 hour in on-site rapid response laboratories and less than 4 hours in regional reference laboratories. To meet these TAT demands, high-speed closed tube sorting is essential. Reduction in the number of aliquots that need to be created also aids in reducing TAT and costly expansion of the number of specimens that need to be analyzed.
The most successful automated reference laboratories process approximately 800 tubes per hour in each pre-analytical automation station, then rapidly transports them to the analyzer with the shortest queues.
Small labs can benefit from some task-targeted automation. When specimens are bar coded at the time of phlebotomy and transported to the laboratory in bulk containers, automated systems can quickly perform the accessioning and sorting process. Bar codes are read by rapidly scanning each blood vial, which is then passed on to a sorting process for placement in take-out bins destined for specific areas of the laboratory. New technology from m-u-t (Henrico, VA), for example, can perform rapid closed tube sorting into bins or directly into racks. Rapid sorters also are available in various sizes and price ranges from Abbott, Aim Lab, Beckman, Labotix, Ortho, Roche, Sarstedt, Siemens and Yaskawa.
For laboratories that have yet to complete their specimen bar coding and tracking systems, particularly from local physician's offices, there are options for automating the accessioning process. Automated accessioning stations consist of a conveyor belt that brings specimens to accessioners arranges along the length of the conveyor (Figure). The input to the conveyor should be as close to the delivery point for specimens so specimens can be unloaded and placed immediately on the belt. The number of accessioners should be matched dynamically to the input rate of specimens. Once each delivery batch has been processed, idle accessioners may be making phone calls to clients and performing other clerical duties.
Figure: An accessioning conveyor belt allows specimens to be retrieved from the conveyor by each accessioner and then transported to the racking station after they are processed.
There are several approaches to sorting specimens for the various analytical stations. A low-cost and highly efficient system developed at Sonic Lab in Melbourne, Australia, uses a partitioned conveyor that enables specimens to be placed in a lane that shunts specimens into an appropriate take-out bin.
Other options include dropping specimens in a "hopper" that feeds into an automated sorting and racking system. The INOVA Health System (Fairfax, VA) uses mobile robots (Speciminder, CCS Robotics, Lapeer, MI) to deliver specimens from the accessioning area to remote areas of the laboratory.
Mobile robots also can be easily equipped to automatically pick up and drop off trays of specimens in locations throughout the lab and hospital (US Patent #6,543,983). Automated pickup and delivery increases the efficiency of mobile robotics by over 20 percent.
In larger laboratories, TLA is an option; it allows laboratories to dramatically increase their annual test volume with only a modest increase in personnel. For example, St. Francis Hospital Laboratory (Tulsa, OK) performs an annual test volume of more than 8,000,000 with an average of four lab technicians managing the automated chemistry, immunoassay, coagulation and hematology systems.
Automation is available for virtually any step in the lab process. ARUP Laboratories has developed a specimen inspection system that automatically checks for proper barcode label placement so improperly labeled specimens can be quickly removed from the processing queue. Future iterations of this inspection system will include a more detailed automated evaluation of specimen.
Automated postanalytical processing can save a significant amount of labor whether the task is recapping the primary tube or automated aliquoting and relabeling. Automated refrigerator and freezers enable automated repeat, reflex or add-on testing.
Automation for 'Biobanking'
Interest in biobanking increases in clinical laboratories as there is significant value in providing specimens with well-documented medical histories to help industry develop novel diagnostic tests or improve existing tests. Automation ensures each specimen was handled according to a known quality process and that it belongs to the right patient. Automated storage at -80°C has recently become available as there is a growing interest in long-term biobanking for longitudinal studies. Biobanks can quickly outgrow their initially designed storage area. Provide for expansion using modular storage systems or develop an off-site expansion biobank.
The future holds increased throughput speed and better integration with a wider variety of instrumentation. For example, urinalysis has been rarely interfaced to the automation track in the U.S. However, SHL Laboratories (Bredda, Netherlands) routinely performs urinalysis using its large track-based system.
Lab directors are increasingly interested in purchasing an automation system that will allow any automation-friendly instrument to be attached and controlled via the process controller. Throughput will increase as more rapid conveyor-based systems emerge into the market, such as the conveyor from A&T (Japan); smart conveyors can perform complex routing in any direction using transporting pallets based on linear motors (MagneMotion, Devens, MA).
Considering the issues that can affect a medical specimen from phlebotomy to analysis, an investment in pre-analytical automation is an investment in the overall quality of a medical institution. Use of automation allows laboratories to dramatically increase their volume of testing with little or no increases in laboratory staff.
Automation has become a routine tool in laboratories and there is likely to be an increase in the sophistication and capabilities of the next generation systems.
Dr. Felder is professor of Pathology, Associate Director Clinical Chemistry, The University of Virginia, Charlottesville.