“We took advantage of this facility to establish new systems for tracking our rodent population. Essentially we wanted a paperless system that was cost effective and could monitor the movement of cages between racks and rooms in real time,” says August Battles, director of animal care services and attending veterinarian at the University of Florida.

In addition to being labor intensive, the University’s previous bar code-only tracking system did not give investigators confirmation when animals were removed from inventory, and there was no real time data. The University’s newly implemented RFID system dramatically reduces labor costs and simplifies the business process, which in turn minimizes inaccuracies, and provides close to real time data.

“One way to think of our mouse colony is as a big warehouse with a lot of inventory. We need to know where the cages are, and how they are moving. Companies like Wal-Mart use the same technology to identify exactly where a product is from the time it is delivered from the manufacturer until it is checked out at the cash register,” says Battles.

ABCs of RFID

There is a wide range of RFID tracking solutions available. Tags, which can be either disposable or reusable, communicate with a compatible antenna to transmit data via radio frequency to a reader, which is attached to a host computer containing data management software. A properly designed RFID system can provide highly accurate real time inventory status on an automated basis with a minimum of personnel and hardware costs.

When considering implementation of a new RFID system, Battles emphasizes that it is important to have well considered policies and procedures established at the outset.

“It’s important to assess as quickly as possible how the new system will impact existing policies and procedures, and if changes need to be made,” says Battles. “There are thousands of types of tags, hundreds of types of readers, and lots of different antennas, and they all have to be compatible.”

Tags are the most diverse component of an RFID system. Passive tags have no internal power and can be embedded in a sheet of paper with an operational range of inches to meters. Passive tags are inexpensive (costing as little as 15 cents each).

Active tags have an internal power source and more than one hundred meters of range but come at a higher cost. Semi-passive tags contain a battery that is activated when the associated antenna sends a signal, but shuts off when not in use.

There are a variety of readers—sometimes called interrogators—that communicate with the tags; these can be handheld or permanently mounted. Different antennas provide linear, circular, or point specific coverage, depending on design.

“The proximity of the RFID components to other materials and the desired coverage on all these readers and tags is important to consider in the context of the facility design,” says Battles.

Associated software packages track the movement of cages among racks and rooms. Software solutions can also support mobile computing, movement of data to other applications, and filtration operations that prevent redundant tag reads.

“There is a lot of flexibility in how to handle the data. It can usually be exported into Microsoft Excel, Access, or SQL servers,” says Battles.

RFID vs. Bar Code

Numerous factors make RFID technology superior to bar code-only systems. While bar code readers require direct line of sight with the tag and have a range that is usually expressed in feet, RFID technology can cover large areas with ranges of a few inches to more than a hundred feet. While the maximum read-rate for a bar code system is one per scan, RFID can handle more than 600 units per second.

“Bar codes are susceptible to dirt, ice, and snow. RFID tags don’t have those issues and they can store pages of information instead of just a few characters,” says Battles.

Elements and Options

The solution deployed in the 45,000-sf vivarium at the Cancer and Genetics Research complex uses the University’s existing tracking software in conjunction with a combination RFID and bar code system. The RFID system consists of passive tags, a wireless RFID cart, and a wireless portable data terminal, all of which are connected to the University’s existing Wi-Fi infrastructure.

In the University’s pre-existing bar code-only facilities, researchers generate a cage card for tracking purposes. In the new facility, cage cards are generated by the researchers, associated with a read/write passive RFID tag, and then associated with the room and rack location. A daily count is conducted using the RFID system. Investigators handle the checkout process at an automated RFID-enabled station.

“The investigator drops the cage card holder with the RFID tag in a box, which then triggers the printing of a receipt. It also sends an email to whomever the researcher wants indicating how many animals were taken off inventory. When it goes off inventory there, it is removed from the inventory in our main server so it’s very close to real time,” says Battles.

UF’s tag solution is a passive mount on metal tags that adhere to the cage card holder. After they go through the cagewasher they are re-routed and used again.

“The tags we have are little bit expensive, but they withstand autoclaving and have a long-term life expectancy. We plan on being able to use them for at least ten years,” says Battles.

In order to adapt the system to existing buildings, a mobile device was developed featuring a rolling cart with computer, antenna, and reader that is walked down the aisles. A room containing 840 cages can be scanned in less than 90 seconds.

“Upon completion of a count within a specific room, a reconciliation report is provided to the user so that he/she can make final corrections prior to leaving the room,” says Battles.

In addition to significantly improving accuracy, the primary advantage of using a paperless RFID tracking system is a dramatic reduction in required personnel time and associated labor costs. According to Battles, scanning 10,000 cages using the former bar code-only system required an average of 440 minutes with an estimated annual labor cost of $70,433. The RFID system can scan the same 10,000 cages in 20 minutes with an estimated annual labor cost of $26,452.

RFID from the Ground Up

While RFID technology holds considerable promise for vivarium applications, the key to implementation is properly integrating the system into a facility. According to Battles, having a solid IT infrastructure and consistent room layout are critical to functionality. He also recommends 100 percent Wi-Fi coverage in order to allow for real-time data flow, which eliminates the need for batch processes.

“It’s good to have a consistent design when implementing these systems. For us, just using the cart reader dictated having a uniform floorplan,” says Battles.

Radio frequencies transmitted by antennas and readers pass easily through walls, but specific zones can be created using metal walls and doors.

“We discovered that a Mylar foil with a metal film on the back of it, or insulation that has a metal foil on it, will block the signal,” says Battles.

When creating a new facility it is useful to develop a mock-up room as part of the planning process to test compatibility and design. Battles also emphasizes the importance of working with an experienced consultant.

“Consult with people who know the technology. The firm we used had 18 years experience working with bar coding and RFID tags. I found there are a lot of people who want to sell these systems, but don’t understand all of the technology,” says Battles.

RFID in the Future

Implementation of the RFID system is the first phase of a long-range plan at UF to adopt more sophisticated tracking technologies. Though the University currently tracks only the cage and cage card, the technology exists to track individual animals, and the University may eventually track larger animal species, such as sheep and pigs.

“On our next building we are considering putting readers in the door frames to track the movement of staff, investigators, and animals better. There’s also the potential for readers affixed to the ceiling in each room, which would allow for census tracking to be done remotely by the touch of a button,” says Battles.

As technology progresses disposable chips are being created at lower costs and smaller, more advanced readers are being developed that will encourage proliferation.

“Using an RFID system is not just about cost savings. It is about keeping our staff happy, motivated, and participating in the development of better procedures,” says Battles.

By Johnathon Allen