RFID: No More Hide and Seek

Radio Frequency Identification (RFID) is a wireless, non-contact use of radio-frequency electromagnetic fields that transfer data for the purposes of automatically identifying and tracking tags containing electronically stored information attached to objects. An RFID system has two basic components: a reader and one or more uniquely identifiable tags. The reader can wirelessly interact with the tags in different ways.

Typically, the reader transmits a signal and listens for a tag-modified echo. The differences between the transmitted and received signal encode information from the tag. This technology offers real time visibility that barcode identification systems currently lack. Presently, RFID uses in the healthcare and hospital setting are seen in patient monitoring, asset management, equipment tracking, EMR data collection, waste management and sample tracking.¹

How does this technology impact our profession?

In the laboratory, inventory management software with RFID technology is just starting to be adopted. Several well-known vendors are now marketing this technology to automate inventory monitoring, tracking, stocking and ordering processes. The system can track key laboratory supplies such as reagents, calibrators and controls. Another equally important application is the emerging use of RFID to tag and monitor patient specimens.

Why do we need to consider utilizing this new technology? There are several advantages of RFID over more traditional barcode labeling:

Feature	Barcodes	RFID Tags and Labels
Holding data	Barcodes can be reprinted / photocopied.	RFID tags and labels carry unique identifiers that positively identify the item they are attached to.
Readability	Barcode scanners require direct line of sight to the printed barcode.	RFID readers do not require a direct line of sight to the RFID tag or label nor does the sample need to be touched by the operator or RFID scanner.
Proximity	The range to read a barcode is typically no more than 5 meters.	RFID tags can be read at much greater distances (depending on tag type up to 100 meters) making them very useful for tracking samples in a busy laboratory, freezer or other storage location.
Multiple Reading	Barcodes must be read one at a time.	Multiple RFID tags can be read simultaneously by a variety of reader types to suit reading of different containers including boxes and racks of samples.
Speed	Reading barcodes is time-consuming as direct line of sight is required.	RFID readers can read RFID tags much faster (e,g. >40 UHF tags/second).
Application	Barcode labels must be placed on the outside of the sample container or asset.	RFID tags can also be used within the sample or container of samples, so they could be used throughout an analytical workflow providing a more complete custody trail.
Ruggedness	Barcode label stock material can be plastic coated and used with different glues for durability.	RFID tags are typically more rugged to different environments and can be protected in a plastic cover creating the opportunity to create novel applications.
Read/Write	Barcode labels are read-only.	Read/write RFID tags can be used which allow new data to be written back on the tag which allows for new applications.
Cost	Barcode labels are generally cheaper but are not reusable.	RFID tags can be reused and the flexibility of uses and associated savings described above can offset the additional cost.

In fact, when working with samples stored in a freezer, an important longer-term advantage of RFID-tagged samples is that the scanner technology described above can, with careful design, be implemented in the freezer itself. This would allow the freezer to inventory itself and report its contents to the user without removing samples from the freezer. If this can be implemented, the security of a the laboratory specimens will increase because any changes to the contents would be traceable to whoever accessed the freezer.³

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