Automation of diagnostic testing.

Laboratory Automation, while just in its infancy, now is considered essential by most clinical laboratories. Total laboratory automation systems automate all five steps in the test process, including preprocessing (sample inspection, sorting, and exception handling), processing (additional sorting, centrifugation, liquid level sensing, quality assessment, exception handling, and cap removal), analysis (sipping from primary tubes, manual aspiration of stats, exception handling, and repeat analysis), post-analysis (recapping and exception handling), and storage and retrieval (sample logging, creation of storage arrays, placement in cold storage, retrieval of repeats, exception handling, and disposal of finished specimens).[1] Table 1 lists criteria useful when comparing total laboratory automation systems.

Table 1
Comparing automation systems

 * Workcell integration (e.g., hematology, chemistry,
coagulation, etc.)
  * Aliquotting, tube sizes, and adaptation to
institutional requirements
  * Input capacity (e.g., primary tubes per hour),
throughput, and stat flow path
  * Transport group design and flexibility
  * Centrifugation and whether refrigerated
  * Process controller, programmability, and
database management
  * Workflow capabilities (e.g., serum level
detection, decapping, cap-piercing, etc.)
  * LIS data transfer and compatibility
  * Testing flexibility (e.g., repeats, reflex-different
test, reflex from storage, etc.)
  * Standards incorporation (point-in-space
  * Physical requirements and layout flexibility
  * Performance monitoring, tracking, and
enhancement for outcomes improvement
  * Staging for modular stepwise growth of system
with added test volume and menus

Commercial laboratories and regional laboratory networks may have the financial resources and the test volumes needed to justify the several million dollar investment in a totally automated system and its daily operation. However, only a small percentage of diagnostic laboratories can afford total automation. Most prefer a more gradual, pay-as-you-go approach in which automation is taken in smaller steps. Since large laboratories have riot yet published any data showing a favorable return on their large-scale investments, small laboratories may have a strategic advantage by implementing less costly, more modular Systems. Here we introduce the concept of modular stepwise automation, which we believe will become the most common strategy in the future of diagnostic testing, especially for medium-sized clinical laboratories and specialized sites such as children's hospitals.

Modular stepwise automation

Until recently, medium to small laboratories had few options for automation. Initially, commercial manufacturers considered the large consolidated laboratories the biggest market for automation. However, there has been a realization that there are many smaller laboratories that could benefit from automation as well. Large automation systems require a high degree of customization, but modular systems can be sold pre-configured for the average laboratory. In addition, the analytical instrument is evolving to become more adaptable to the needs of modular automation. For example, analyzers aye now on the market that combine the analytical functions of chemistry, immunoassay, and toxicology into a single platform. When a group of laboratory tasks are linked together through a common user interface and a single LIS connection, one has created a workcell.

Worked criteria

In evaluating a modular workcell system, there are eight areas to consider.

1. Testing performed. What type of testing is performed? Chemistry, etc.?

2. Optimal throughput What are the optimal tube sizes and workload characteristics (e.g., peak, random access, optional)?

3. Sample tube handling. How are sample tubes handled (direct sampling, cap piercing? What is the rack size? Does it read bar codes?

4. Information transfer. How is information transferred? How are data transferred to and from the laboratory information system (LIS)? How are data managed? Is there an expert system? How are the control and status monitored?

5. Automation accommodation. What types of automation are accommodated? Boehringer Mannheim/ Hitachi? Beckman-Coulter/IDS? Lab Interlink? MDS? Labotix? Bayer?

6. Sample acceptance criteria. What is the acceptance criteria? Does it fit the de facto standard? Can it read coded, conveyed tube and holder? Does it perform internal reflex testing?

7. System processing How does the process controller operate? What is the number of tests before being replenished? What is the sample size? What is the liquid level sense? What is the basis of sense?

8. Integration. How does the workcell integrate? What are the measures for quality control and quality assurance? How is the process controlled? How is scheduling the process performed? How is the process optimized for efficiency?

Selected portions of total laboratory automation systems also can be sold in smaller units and thus, in some cases, become modular analytical workcells (Figure 1). Some systems have been installed as a fully configured total laboratory automation system. Modularity assures that the laboratory can add additional automated devices to the system backbone as automation needs grow. For most small clinical laboratories on limited capital equipment budgets, or for those who do not want to incur much risk, modular automation can be implemented conveniently and efficiently in a stepwise manner, to match needs. In this way, large benefits are gained from automating, while incremental costs are relatively modest.

[Figure 1 ILLUSTRATION OMITTED]

Modular stepwise automation requires that the vendor has considered the connectivity of each modular unit in the design of the system. For example, Automed (Richmond, British Columbia, Canada) has engineered three independent floor model automation devices: an automated centrifuge, a tube sorter, and an aliquotting device. Each sample processing device can be loaded with primary tubes and will perform a specific task. The conveyance mechanism that transports the racks is built into each modular unit. If the laboratory wishes to complete these tasks in tandem without the need for the manual labor associated with transferring tubes from proem to process, then each component can be linked together to create a larger automated system.

Beckman-Coulter also provides an upgrade path through the addition of conveyor belt modules that allow the incremental addition of chemistry, hematology, and other analytical workcells. Some vendors have focused on specific markets while providing the connectivity to other commercial systems. For example, Sysmex (Long Grove, IL) provides both coagulation and hematology systems The hematology or coagulation systems can operate as stand-alone instruments or as automated workcells through the addition of a conveyor belt. Pre-analytical processing and chemistry are provided through their marketing partner, Boehringer Mannheim/Hitachi (Indianapolis, IN).

The greatest initial gains in efficiency following modular automation of the laboratory typically reside in the automation of pre-analytical processing. Prior to analysis, there am many manual steps, such as sorting, centrifugation, and aliquotting. Calculating a return on investment is difficult for some aspects of modular automation. However, economical configurations of pre-analytical processors are considerably less expensive than a totally automated laboratory. A minimally configured pre-analytical processor can save up to 2.5 technologists in a medium sized clinical Laboratory.[2]

Implementing automation yields other benefits to the laboratory aside from the calculable reduction in full-time equivalents (FTEs). For example labeling and filling aliquot tubes from primary specimens are not only tedious, error-prone tasks, but also dangerous ones for technologists. There is a higher likelihood of direct contact with the primary specimen at this point through aerosols, blood splashes, and cuts from glass tubes.[3] Automated aliquotters reduce the tedium and labor associated with specimen aliquotting, as well as the dangers, and have been introduced in various configurations.

The Autoquot from MDS (Etobicoke, Ontario, Canada) inserts a plastic device through the stopper of a vacuum tube to prevent potential aerosols from forming by decapping. The serum or plasma is then removed from the vacuum tube by injecting air into the inverted tube. Alternatively, several systems remove the cap of the tube and then aspirate the contents using a disposable pipette tip. Potentially dangerous aerosols can be formed using this method, but the process is made safe through automation because humans are no longer involved.

Modular automation also can shorten the pre-analytical process much more than humans are able to, so most laboratories that acquire automation will have the opportunity to eliminate the need for a separate stat laboratory. This redesign can decrease the turnaround time of all laboratory tests performed in the automated system. The financial benefits of improved turnaround time, decreased laboratory errors, reduced exposure to contamination, and improved operator morale are difficult to assess. However, the elimination of the stat laboratory will reduce the need for FTEs dedicated exclusively to stat functions.

There are additional options on the market that use modular automation. The key is to remain efficient and flexible. Future modules should be attachable to the basic system backbone. For example, modular units can be obtained for robotic transportation, sorting and aliquotting, centrifugation, and other functions. Much of the technology operates independently of other automated systems in the laboratory.

Modular automation will be increasingly effective when standards are adopted that will allow simplified coupling of modular units together to form systems capable of more complex tasks. Standardization groups (e.g., American Society for Testing and Materials, National Committee for Clinical Laboratory Standards, International Federation for Clinical Chemistry, Japanese Society for Clinical Laboratory Automation) are considering the adoption of international standards governing both mechanical and data communication systems. Laboratory automation will be truly practical when sensible standards are adopted uniformly in the US. and elsewhere.

Point-of-care automation--How it fits in

A third component of laboratory automation is point-of-care automation (Table 2). Testing at the point of care is considered by some to be more costly than testing in the main laboratory. However, automating point-of-care testing can result in costs that are less than half of performing the same test in the main laboratory.[4] Initially developed at the University of Virginia, remote review of testing is becoming a widely available technology.[5] Point-of-care automation can provide the rapidity required for critical care analysis, yet allows existing staff mentors to be used for laboratory tasks. Point-of-care automation systems simplify the analytical process so that use of the analytical workstation is less burdensome than preparing the specimen for transportation. Linking point-of-care analytical stations with the central laboratory's information system allows timely monitoring and control by central lab personnel to assure economic utilization.[6,7] We anticipate that the majority of common laboratory tests will be performed at the point-of-care within the next 5-10 years.

Table 2
Features of automated
point-of-care systems

     Interface to instruments from many vendors

  * Provide bi-directional remote control and remote
review of analytical processes
  * Can be operated by non-laboratory personnel
  * Provide intuitive touch screen graphical user interface
  * Interface with popular laboratory information
systems
  * Integrate quality monitors and proficiency testing to
fulfill the total quality concept for point-of-care testing

Many frequently ordered tests, such as glucose and prothrombin time, already are available throughout the hospital and at home as waived tests for ambulatory patients. The development of new whole-blood methods is progressing rapidly and will allow several additional tests to be performed at or near the bedside in the hospital, where we also anticipate that automation will play an important role. Several first generation point of-care-automation systems are on the market Second generation systems will auto-verify results, have graphical interfaces, and require laboratory intervention only when critical conditions manifest themselves.

Ultimately, most common tests will be performed within the immediate vicinity of the patient through the use of microfabricated and nanofabricated devices with patient-focused, user-selectable test clusters. The devices will be smaller, perform more tests, and have disposable test modules. They will be easier to integrate into the ward space available and will be individually automated. Widespread use of these new technologies favors a strategy of localized sites of diagnostic testing using the principles of modular automation outlined above.

In part 2 of this series, Drs. Felder and Kost discuss the optimization and integration of individual processes and the involvement of the lab in real-time decision making.

References

[1.] Felder RA. Automation of pre-analytical processing and mobile robotics. In: Kost GJ, ed. Handbook of Clinical Automation. Robotics, and Optimization. New York, NY: John Wiley and Sons; 1996:252-282.

[2.] Felder RA. Modular laboratory robotics and automation. Journal of the International Federation for Clinical Chemistry. 1997;56-60:9.

[3.] Estey CA, Jagger J, Felder RA. Studies show plastic specimen tubes viable, safe option. Advance Newsmagazine 1997:9(5):5-7.

[4.] Felder RA. Cost-justifying laboratory automation. Clin Lab News. 1996;22(4):10-13.

[5.] Margrey KS. Felder RA. Boyd JC, Holman JW, Roberts JH, Savory J, Martinez A., inventors, University of Virginia, assignee. Robotically operated laboratory system. U.S. Patent 5366896. November 22, 1994.

[6.] Felder RA. Robotics and automated workstations for rapid response testing. Pathology Patterns. Am J Clin Pathol. 1995;S26-S32: 104.

[7.] Felder, RA. Robotic automation of near-patient laboratory testing. In: Kost GJ, ed. Handbook of Clinical Automation, Robotics, and Optimization. New York, NY: John Wiley and Sons; 1996:596-619.

Robin A. Felder is professor of pathology and director of the medical automation research center, University of Virginia Health Sciences Center, Charlottesville. Gerald J. Kost is professor of pathology and biomedical engineering, University of California; and director of clinical chemistry, University of California, Davis, Health System.