Washington Hospital Center to Quadruple Its RFID Expansion

Parco's tags operate at the 6.5 GHz band and utilize UWB technology, whereby devices emit a series of extremely short pulses (billionths of a second or shorter) across a frequency segment wider than that used by conventional RFID tags. Because Parco tags use multiple frequencies simultaneously to transmit their signals, the company claims, they can transmit a greater volume of data more quickly.

Washington Hospital Center is using two types of UWB RFID active tags. The asset tags are 1-inch cubes screwed or glued to equipment; the medical staff wear tags the size of credit cards, either clipped onto clothing or attached to a cord worn around the neck. The hospital is considering several options for patients, including embedding the tags into wristbands or attaching them to medical records that remain with the patients—an option that, according to Dade, makes more sense for those undergoing surgical procedures. The interrogators can detect tags at a range of 600 feet, and the tag's battery can last from one to five years, depending on how frequently reads are taken.

Each tag has 32 bytes of data and transmits a unique ID number, as well as information on battery status, whether the tag has been tampered with and the location of the medical device to which the tag is attached. The hospital is developing software that will enable it to build relationships between two tags—one affixed to a bed, for example, and another affixed to an IV pump—to make determinations about the items. "If an IV pump is within 2 feet of the bed, it's likely being used, so we will know to look elsewhere for an available pump," Dade says.

The data generated by the Parco location-tracking system will populate the hospital's clinical information system (CIS), called Azyxxi (which rhymes with "Trixie"). In addition to serving as a repository for a patient's clinical information, Azyxxi provides caregivers access to comprehensive patient information, including EKGs, scanned documents, X-rays, CT scans, MRI scans and ultrasound images. Doctors at Washington Hospital Center designed the system using Microsoft software-development tools; in July 2006, Microsoft acquired Azyxxi and partnered with the hospital to continue developing and enhancing it. By logging into the CIS, nurses, doctors and support staff at the hospital will be able to locate any medical equipment or staff they're looking for within 2 feet.

After its initial installation of Parco's UWB RFID system in late 2004, Washington Hospital installed another three readers and 40 tags in an office area. In the past year, the hospital has added Ethernet cables throughout the entire facility to accommodate all the readers needed to track the tags. Dade says installing the cable was time-consuming, in part because of the age of the hospital buildings, which date back to the 1930s.

"The walls are thick, and in some cases, there is lead shielding," Dade says. "In areas where we thought we could get 4- to 5-foot coverage off of one [reader], we were, in fact, only getting about 3 feet off of one, because of a lead wall. So in some cases, we had to add more receivers."