RFID – a passive solution

April 23, 2015
by Sean Ruck, Contributing Editor
RFID offers a low cost alternative, or supplement, to RTLS systems by providing location data at a fraction of the cost of most RTLS infrastructure, although the visibility into a person’s, asset’s or medication’s location is restricted to the last time a tag or badge was scanned at a portal or by a handheld reader.

Passive RFID features a UHF, HF or LF tag that is battery-free, making it smaller and less expensive than its active RTLS sensor or tag counterpart. However, eliminating real-time functionality creates limitations. The tags only respond where scanned and no facility will have enough readers to scan the tags at all times. Therefore, a facility’s best strategy is to ensure the tags are read during key events such as the movement from one department, or one building, to another; or when a medication, blood or other product is administered to a patient.

Most commonly, hospitals use RFID to track their lower value assets, staff, or consumable items that don’t require constant location knowledge. RFID can also be used as redundancy in the event an RTLS tag isn’t functioning. Passive RFID tags, typically priced below a dollar, could be placed on every – and any – asset within a health care facility, and could then be tracked according to zones set up at that facility. In this way, as the equipment, people or items such as blood and medications pass through a portal between one department and another, the software can automatically be updated to indicate where the item was detected and in which direction it was moving.

In addition, hospitals use handheld readers for more granular audits or just to seek out a missing item, allowing individuals to walk through an area with the reader in “Geiger Counter” mode to find a specific piece of equipment, or simply to read everything tagged within the vicinity to update status lists.

Passive RFID can also be used to create automated records of what medication was administered to which patient and by which health care provider. In this case, the unique ID on a medication container’s tag can be read with a handheld reader and paired with the ID number of a patient’s wristband and the ID number in the nurse’s badge. Such systems are also being used to prevent unintentional baby mismatching in maternity departments. When nurses bring an infant from the nursery to its mother, for instance, the RFID tags built into the wristbands of mother and baby are read with a handheld reader and the system will display an alert if a mistake is being made. Such a system also enables the hospital to store data about how often the baby has been brought to its mother and when.

To prevent abductions, a passive RFID system could include reader portals and egresses such as stairwells and elevators. If an infant tag is read in an unauthorized area such as an exit, the system software could forward alerts or even prompt the locking of doors.

Because passive RFID tags do not require a battery, they can be extremely small and durable, opening them up for use in areas where RTLS isn’t as convenient, such as the tracking of surgical tools. With an RFID tag attached to forceps or a pair of scissors, staff can use a reader to verify that all tools are present in a surgical kit, identify if something has been misplaced, and ensure that all used tools are accounted for after a surgery is complete, thereby guaranteeing nothing ever remains in the patient cavity inadvertently. The tags are sturdy enough to sustain the washing and sterilization process of the tools as well.

Similarly, such RFID tags are used to track blood products. Unlike larger RTLS tags, the RFID labels can be easily affixed to small vials or plastic bags filled with fluids, and are low-cost enough to be disposed of when the contents of the container are used or discarded.

RFID also offers redundancy when RTLS sensor batteries fail. In some cases the battery life of RTLS sensors can drop off quickly, and often unexpectedly, and assets tagged with dead devices simply cannot be located. Some health care facilities use RTLS technology augmented by passive RFID tags that are used to track smaller items and act as backups to the RTLS solution.

As more hybrid installations occur, software companies have been developing workflow-and asset management platforms to enable the retrieval of data from a variety of disparate systems, including RTLS and RFID, and to use that information to identify workflow and track exceptions, as well as issue necessary alerts to the appropriate employees if those exceptions occur.

For hospital management, the challenge is to determine specific needs and find a partner that can help them install a system that is customized not only for their existing requirements but is flexible enough to grow with technology innovations and with the hospital’s own operations, so that it will bring them value for many years to come.