Mary Washington Hospital to Deploy RFID Facility-Wide

Finally, according to Carrasco, Mary Washington Hospital will employ RadarFind's tags and system to monitor the temperatures of refrigerators used to store medicines and vaccines. If a refrigerator is accidentally left open, or ceases to function, the problem might not be discovered until it is too late, he says, thereby ruining thousands of dollars' worth of medicines.

In June 2008, RadarFind extended its system's sensor capabilities to enable customers to track temperatures, capitalizing on a capability that allows the tags and readers to gather environmental data to monitor their own health. If, for instance, a reader plugged into an outlet were to begin overheating, the embedded sensor would detect that problem and alert the RTLS (see RadarFind Offers Temperature-Sensing Tags). The firm developed a software upgrade to its RTLS that leverages the temperature-sensing capabilities so tags can, for example, be placed inside refrigerators or freezers to monitor their temperatures and provide instant notification of variances. If the temperature within a particular refrigerator varies beyond a preset range, an alert can be sent out via e-mail or text to the wireless devices of specified personnel, in accordance with hospital protocols.

Refrigerators typically have doors made of metal, which can interfere with UHF RF signals, primarily by reflecting them. Nonetheless, says Steve Jackson, RadarFind's CTO, the company's tags are still able to transmit their signals to readers situated outside of a refrigerator, because of what's known as RF aperture.

"The door of a typical refrigerator is sealed with a gasket, which is not metallic, and which forms a sizable gap for the radio waves to go through," Jackson explains. "The dimensions of this gasket are far larger than needed for a significant amount of signal to exit the refrigerator, at the frequencies we use. This gap, transparent to our radio signals, is referred to as an aperture."

If the aperture is of sufficient size, it's as if the door weren't there—thus, the read range is unaffected. In addition, RadarFind readers will be installed with sufficient proximity to tagged refrigerators.