Automation in the clinical lab: a reliable tool gets even better

July 18, 2013

Having been around for decades, automation tools are familiar in today’s lab. A simple linear barcode symbol read with a handheld scanner is a no-brainer for accurate data collection; it’s been the go-to solution for more than 20 years. But today, performance and productivity expectations for labs have escalated dramatically. Test results must be accurate, timely, and cost-effective. Fortunately for lab managers, barcode and related automation technology has advanced to meet these heightened expectations.

The last several years have given labs many innovations that show marked improvement in data accuracy, reliability, and availability throughout the lab’s operations. The areas with the most expanded capabilities are labels, barcode symbologies, printers, print-and-apply systems, service bureaus, and RFID.

The latest on labels

Labels are often the least expensive part of a lab’s automation program, but a label that fails is costly. Label engineering has advanced to the point where it would be difficult to define an end-use environment in which a custom-engineered label won’t work. Today’s labels can:

  • withstand significant temperature extremes
  • resist harsh chemicals and stains
  • remain affixed to flat or curved metal, plastic, glass, and ceramic surfaces.

For challenging adhesive environments, the “wrap around” label often works well. The label, which can be printed by a thermal transfer printer, wraps all the way around a cylindrical container and sticks to itself. In addition to surviving liquid nitrogen storage, the labels are capable of withstanding autoclaving and exposure to solvents such as DMSO, methanol, and isopropyl alcohol.

What are the factors that determine whether pre-printed or print-on-demand labels are best for a lab’s needs?

Pre-printed labels are often the best choice when a unique identifier, sometimes referred to as “license plate” identification, is used. License plate identification, as the name implies, is simply the assigning of a unique number to a sample. While the number itself contains no significant information, other sample-specific information is contained in the database and can be accessed upon scanning the unique bar-coded number. This typically has the advantage of shorter barcode messages, but requires database access in order for the user to correctly handle and process the sample.

Print-on-demand solutions are best when significant numbering is required; that is, when the number itself contains significant identification information rather than merely unique identification. An example would be a sample number that indicates the source of the sample with the first three characters, the unique sample ID with the next four, and the Julian date the sample was accessioned with the final three.

Because pre-printed labels are often the most cost-effective solution and are more highly engineered for their end-use environment, on-demand printing is typically chosen only when the data to be encoded is not known until the label is needed.

In the lab, clinicians seldom complain of too much information—at least when it comes to their samples. For labs that require more data than a linear symbol can comfortably encode (roughly ten alphanumeric characters per lineal inch), several two-dimensional barcodes have been developed and are widely supported. Camera-based readers are required to read these symbols, but they do not require significantly higher budget outlays than linear scanners.

Barcode printers

Gone are the days when the lab manager had only a handful of choices in barcode printers. The best technology for barcode symbols is thermal transfer, and printers of that type are now available in a wide variety of prices and with functionality to match.

Small, low-cost printers are now available for use when lab space is at a premium, budgets are tight, or output requirements are small. It is easy to acquire a desktop thermal transfer printer for under $1,000, while more sophisticated, multi-color printers can cost up to ten times that amount. Some printer manufacturers are also offering expanded interface options on their standard models, including Ethernet, USB, RS232, and wireless connectivity.

Print-and-apply systems

Labs with legacy barcode systems might be hampered in their ability to compete with labs that have more recently updated their capabilities. One significant area of improvement over the last few years is the automated application of a printed label to an item. There are now modular thermal transfer printers that can morph into sophisticated print-and-apply systems via a bolt-on assembly that takes the just-printed label from the release liner and places it on a flat or cylindrical surface.

Many labs simultaneously process several types of sample containers that require labeling. There are now print-and-apply systems that can efficiently handle multiple labels for multiple surfaces. Taking up very little space in a crowded lab, these systems can print-and-apply any customized label from 4 x 4 mm to 100 x 100 mm. The device can accurately print and precisely place up to 12 distinct labels at once to any surface, whether flat or curved.

It’s now easier than ever to connect these devices to laboratory information systems, as firms specializing in lab automation have developed software interface expertise for seamless integration.

Sample management software

Whether standalone or fully integrated, advances in sample management software packages have been significant. Off-the-shelf products are now available that allow up to 2,000 user-defined fields and can accommodate up to 100 million unique samples, aliquots, or transactions. Client/server versions are available using TCP/IP protocol and a fully automated back-up system. These packages handle everything from assigning samples to existing storage facility locations to keeping track of shipping destinations for those samples—and pretty much everything in between.

Service bureaus

If you want the productivity benefits of barcode data collection, but don’t want to actually apply barcode labels yourself, it is possible to outsource sample identification and have pre-labeled, ready-to-use labware delivered. Slides, tubes, and other containers can be uniquely labeled with either a pressure-sensitive adhesive label or a ceramic symbol that is permanently fired onto the surface. Firms specializing in this service provide a guarantee of scannable barcode symbols with no duplicates and in the exact sequence(s) required.

Tare weighing services can be added to pre-labeling to further enhance lab efficiencies. Because of the critical nature of tare weighing, it is performed in a dedicated, controlled environment. Typical specifications offer weights to 0.1 mg and an accuracy of ±0.2 mg.

What’s next in clinical lab automation?

Radio frequency identification (RFID) could dramatically change the landscape of how samples are identified and tracked. While it hasn’t yet proven to be a cost-effective alternative to barcodes, it does hold much promise as a technology. Two primary technical advantages distinguish RFID from barcodes: RFID-labeled samples can be read without a line-of-sight, and the data encoded on the sample container can be changed (multiple times) from a distance.

Non-line-of-sight reading. The operator does not need to see the item(s) being read in order to successfully collect the data. Envision a carton of uniquely-identified sample containers, each with a “smart label” attached. The carton is sent through a tunnel reader, which instantly reads each container without opening the carton. Because it is linked to a database containing the identification of every sample expected to be in the carton, it can also indicate whether or not samples are missing.

Dynamic data storage. With an RFID-enabled label, data on the chip can be changed without replacing the label. With read-write chips, the data stored can be modified and updated as needed when, for example, specific tests are completed and other procedures added. So, although the text on the label doesn’t reflect the updated information, the chip itself provides its current status in real time.

As is the case with most new technologies, the primary problem with RFID is cost. Read-write chips with sufficient data and the hardware to read them are costly when compared to barcode hardware. In addition, firmware that provides reliable data handling needs to be purchased or developed. While this shouldn’t discourage today’s lab managers from investigating RFID’s potential, it should be a reminder of the importance of comparing costs to expected benefits.

Managers of today’s clinical labs have a broad range of identification tools, and related automation technology, available to them. Choices can be overwhelming, which means partnerships with trusted and experienced vendors are more important than ever. In order to leverage all the potential benefits of automatic identification and automation in your lab, you need a solution that meets your unique needs.

Bruce R. Wray is a market manager for St. Paul, Minnesota-based Computype, Inc. He has more than 25 years experience with automatic identification solutions.

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