Missing car keys as you attempt to leave the house are an inconvenience, but misplacing important equipment in a hospital could lead to tragedy.

Since location systems have been added to wireless LANs (read a White Paper from Airespace) little has been heard of actual uses. Location is considered overkill for security, and other applications tend to be high-profile ones, like Legoland's use of Wi-Fi to track lost children.

Hospitals are the richest source of location-awareness anecdotes, and the field already has specialised non-Wi-Fi systems available. The Hospital of University of Pennsylvania (HUP) is one of several hospitals that believe an indoor positioning system solution (IPS) will be the solution to time lost searching for misplaced equipment.

The PeriOperative Services group at HUP recently installed a healthcare-focused IPS. The supplier, Radianse of Massachusetts, describes it as the indoor corollary to the global positioning system. Battery-powered active-RFID-tags, which do not interfere with medical devices, are attached to hospital equipment. Receivers, which plug into the existing local area network (LAN), detect the tags, and communicate positioning data to location software. Physical locations are graphically displayed on a web interface, accessible from any PC on the hospital's LAN.

Hundreds of items are currently tracked using the system. It is especially valuable for high-value, low-volume equipment. Doctors at HUP can see if a particular item is in one of 31 operating rooms, any equipment storage room, or pre- and post-operative care areas and adjoining spaces, all defined as "zones" by the system.

How about tracking staff?
The IPS is not limited to tracking materials. The PeriOperative Unit at Massachusetts General Hospital has been using the Radianse system for 2 years to track patient and staff flow, aiming to optimise logistics. At its sister hospital, Brigham and Women's in Boston, a pilot program tracking materials within the cardiac surgery service is under assessment. According to John Pantano of Radianse, "the preliminary indication is of significant return on investment, with a break-even point of about 12 months."

Medical equipment has become more specialised and expensive. "It isn't practical to have one of everything for every operating suite," says said Jim Mullen, M.D., associate executive director of HUP and corporate director of PeriOperative Services for the University of Pennsylvania Health System. Nor is it necessary to duplicate resources when the existing equipment can put in the right place at the right time to serve the patient.