When choosing bar code readers for use in hospital pharmacy settings, usually the main decision criteria are ergonomics, the effect of the scanner type on workflow, and overall cost. However, given the rapid evolution of two-dimensional (2D) bar codes on pharmaceutical packaging, firmware considerations—or the ability to upgrade or replace certain software elements—should be included in any thorough evaluation of bar code scanners. Bar codes have evolved from the basic, linear type we are all familiar with to more sophisticated, 2D types, the popularity of which is owed to a significant increase in information capacity combined with fewer readability errors and decreased space constraints. Given these benefits, it is quite plausible that 2D symbols will become the prevalent symbols used on pharmaceuticals and related supplies. With this in mind, it is important to choose bar code readers with firmware that can support this evolution in packaging.
2D Bar Code Symbols
Currently, there are two types of 2D bar code symbols—stacked codes and matrix codes. Stacked bar codes are exactly what they sound like—linear bar codes that are stacked in two or more tiers. These bar codes contain a scanning quality called vertical redundancy that helps ensure the codes are readable even if partially damaged. Because they are “bars” and not small squares, localized damage does not always render the symbol unreadable. This type of code can be read with linear scanners or 2D imagers.
Matrix codes are composed of a grid of nominally square individual elements. The advantage of matrix codes is that they can represent more information than a stacked bar code while using the same space and have a larger feature size (equivalent to a bar code’s X-dimension—the width of the narrowest bar and space). This facilitates easier printing and reading of the symbols. Matrix codes do not offer vertical redundancy; they rely on error correction algorithms to recover lost data elements. Matrix symbols can be read only with 2D imagers.
There is a special variant type of symbology in the GS1 standards called composite symbols that employ a small stacked bar code on top of a linear bar code symbol. These were designed to provide secondary product data such as lot/batch or expiry in the composite part of the symbol but have primary product identification in the linear symbol for backward compatibility. The data in the two symbols are linked by the use of a linkage flag—a thin strip of code between the two symbols.
Bar Code Symbologies
Bar code readers often are capable of interpreting different symbologies, or data languages. Depending on what the symbology is meant to convey, the differences can be important considerations. Among the most commonly used symbologies for pharmaceutical and health care applications are EAN/UPC, GS1 Data Matrix, and GS1 DataBar.
EAN/UPC is the symbology most commonly used in pharmaceuticals today for both OTC and ethical drugs. This is the same symbology used in retail and every bar code reader is configured to read it. It encodes a standard 14-digit Global Trade Item Number (GTIN) which is typically the NDC.
Data Matrix, the most widely used matrix symbology, is approved for marking of small items by GS1. It is now commonly used on pharmaceuticals to encode product identification such as lot/batch and expiry, typically using the GS1 system. GS1 Data Matrix is identified by the presence of a non-ASCII (symbology only) character: FNC1. It is important to note that Data Matrix symbols are also used to encode proprietary information that previously might have been encoded in Pharmacode (Pharmaceutical Binary Code). The manufacturer encodes this data to ensure that the correct packaging, inserts, and other content are loaded on automated packaging lines. It is critical for hospitals to configure their readers to reject any non-health care symbols (see Figure 1).
GS1 DataBar (formerly RSS or Reduced Space Symbology) is actually a family of symbologies wherein all the variants are designed to increase data density. There are six versions: Truncated, Limited, Expanded, Omni (directional), Omni (directional) Stacked, and Expanded Stacked. While conventional linear symbols can be scanned with a wand, the stacked versions contain small elements between the layers that provide a sort of bridge between the pieces of the symbol, thus these cannot be scanned with a wand and a linear scanner or 2D imager must be used to ensure an efficient reading of these symbols (see Figure 2).
GS1 DataBar omni, truncated and limited (including stacked versions) encode only the GTIN (although the limited version can only be used for prefix 0 and 1). Expanded and expanded stacked symbols will typically be used to encode secondary data such as lot/batch, expiry, and other data. Some pharmaceutical manufacturers are beginning to include GS1 DataBar symbols on packaging but there is no date for the EAN/UPC symbol to be entirely replaced. While this is a new symbology, most scanners and imagers include RSS reading capabilities; this is just the previous name for the symbology.
Composite code symbols have been around for a number of years. They combine a standard GS1 linear bar code (EAN/UPC or GS1-128) with additional information in a PDF 417 stacked bar code on top of the standard symbol. It is possible that these symbols will eventually be replaced by GS1 DataBar Expanded since both primary and secondary product information are linked in a single symbol as opposed to being in a separate, although linked, symbol.
Other Matrix Symbols
While not directly impacting pharmacy, there are some other matrix codes that are coming into the health care environment. Both QR Code, which is gaining in popularity with social media and mobile applications, and Aztec Code are being used on patient wristbands. These symbologies may also become more common, along with Data Matrix, on paperwork and other types of documentation. Matrix symbols require a 2D imager and it may be advantageous from a purchasing perspective to negotiate for a single type of bar code reader for the entire hospital rather than different ones for different departments. However, the ergonomics of the reader in each environment must also be considered and different types of scanners may be preferable for bedside and the pharmacy.
Both linear bar code readers and 2D imagers come in a wide variety of form factors—fixed location, hand-held, fixed/hand-held, and wearable—and in a wide range of prices. In addition to reviewing each unit’s ergonomics, affect on workflow, system duty cycle, user perception, and cost, it is important to consider firmware flexibility and configuration to ensure your new product will meet the pharmacy’s needs over the long term. As bar code technology continues to evolve, changes to the reader’s firmware might be required to keep the readers up-to-date. To purchase readers that provide this flexibility look for options such as the ability to disable any symbology or variant not being used. Also consider the ease of the system’s configuration process and whether it must be returned to the vendor for upgrades. It is wise to consider not only what a proper bar code scanner and reader can do for you now, but also what it will do for you in the future.
Bert Moore is a 25-year veteran of the automatic identification and mobile IT industry. He founded IDAT Consulting & Education, a technology- and vendor-independent consulting firm located in Hickory, NC in 1993 to help companies understand, evaluate, develop, and implement automatic identification and data collection solutions. He also serves as the director of technical communications and media relations for the automatic identification industry international trade association, AIM, Inc. He is the 2010 recipient of AIM’s “Excellence in Journalism” award.
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