On Wednesday, June 25, the Journal of the American Medical Association published a report warning that radio frequency identification (RFID) techniques may disrupt the operation of intravenous (IV) pumps and other medical equipment, and occasionally induce potentially hazardous incidents in other medical devices.

However, the tests were performed on passive 125-kHz and 900-MHz RFID devices. Omitted was Ultra Wideband (UWB) technology, which one of its advocates, the Time Domain Corporation, says precisely locates and monitors the interaction of assets, over a distance up to 1 meter, through walls in a host of new healthcare applications. And since UWB operates at transmit power levels that are 10,000 times lower than the medical devices tested, the company claims UWB poses no significant interference threat in healthcare environments. In fact, UWB is said to be indistinguishable from the unintentional RF noise that exists in hospital environments.

The Federal Communications Commission (FCC) regulates unintentional radiators by setting the maximum power output level allowed. This is commonly referred to as the noise floor and sets the maximum level of junk RF that can be present in any environment. The FCC regulates RF emissions to ensure that no such harmful interference occurs. In doing so, the FCC makes a distinction between intentional radiators — such as cell phones and Wi-Fi access points — and unintentional radiators — such as computer monitors and electric motors.

Intentional radiators are easy to manage by defining what frequency they can operate on. The level is very low – approximately 10,000 times less power than a cell phone transmits. And by law, an UWB transmitter is not allowed to radiate power above this noise floor. In fact, the regulations ensure that UWB emissions are indistinguishable from unintentional radiation – UWB looks just like junk RF.

Healthcare environments are littered with unintentional radiators, from computer monitors to IV pump motors. This means that hospitals are filled with electronic devices, so that there is definitely a sea of junk RF at power levels below the noise floor.

Unlike traditional RFID technologies that transmit significant power on narrow frequencies, potentially causing harmful interference with medical devices, UWB looks just like junk RF, and is therefore no threat. Those same medical devices that are already designed to be unaffected by that noise are therefore implicitly designed to be immune to UWB.

A certified UWB RFID tag will have an FCC ID clearly displayed on its underside.

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