Departments & Programs,UW Hospital and Clinics,Clinical Engineering


RFID Tags - Departments & Programs, UW Hospital and Clinics, Clinical Engineering


We’ve all felt that rush of panic while searching for our misplaced car keys, each tick of the clock growing louder and stronger as time runs down on making it to work or picking up the kids on time. At best it’s just a frustrating experience that leaves one flustered and behind schedule. If you are really unlucky the keys are lost and will need to be replaced, sending you on a frantic search for your spare set. 

Now imagine having that experience at the CSC during an emergency. You need an IV pump but can’t locate one. You need a specific set of surgical instruments but aren’t sure where they were used last. In the past to help alleviate these types of situations, UWHC Central Services kept tens of thousands of dollars in spare equipment around to ensure proper availability of equipment. A few years ago they started looking for a more efficient solution to their asset location/distribution issues. 

“A lot of it had to do with saving money because we could make better use of what we already had,” said Bob Scheuer, director of materials management. “Right now I know I have a lot more patient equipment than I otherwise would need to have if it was all returned to me when it wasn’t being used.” 

As a solution to the problem, Central Services decided to install a state of the art Real Time Location System (RTLS). An RTLS allows the hospital to lower costs by reducing the number of items needed to be kept in stock, lowering the amount of equipment lost and allowing for real time tracking of critical patient care equipment. 

When it came time to decide on which type of RTLS to implement, Central Services took a practical route. They elected to go with a Radio Frequency Identification (RFID) system, because that type of system could leverage the CSC’s existing 802.11 WiFi network. 

“Other technologies required a separate network which would need to be purchased, installed, maintained and enhanced,” said Scheuer. “We decided to go with RFID because we already had a state of the art WiFi network and if we needed to plus up that network to make mobile asset location work better, then everybody would benefit. It just made sense to leverage what you have and make it better for everybody’s use.” 

Using RFID technology also allowed UWHC to draw on the expertise of the University of Wisconsin. UW is one of only a few campuses in the country to have an RFID lab and the lab’s experience, knowledge and helpful graduate students were beneficial in selecting a vendor. 

Cost of the implementation was further lowered by partnering with St. Mary’s Hospital in Madison and Froedtert Hospital in Milwaukee. The partnership also allowed the participants to take advantage of the collective knowledge and experience gained as each institution implemented their RFID systems. 

The partnership selected AeroScout as the vendor, and to date nearly 4000 items are currently tagged throughout the CSC and AFCH. Once tagged an item can be tracked using AeroScout’s MobileView program to within 5 meters of its exact location. 

RFID technology works to locate items by using wireless access points located throughout the building. Each access point knows its relationship to the others, so when a tag is sensed from more than one access point, its location can be triangulated to within 5 meters. Some places in the hospital may have worse accuracy, some better depending upon the strength of the system in that area. 

One thing to know about RFID systems is that they don’t understand structure. Just as you can listen to the radio indoors, the radio waves from the RFID system pass through walls without “knowing” they are walls. But not knowing if an item is in a room or not is a small inconvenience in the grand scheme. 

“Before we didn’t know if an item was in the building, much less what floor it was on,” said Scheuer. “So telling me where something is within 5 meters is glorious because we have thousand’s of things we need to find.”