The medical profession, as well as most others, rely more and more heavily on the use of radio frequency identification devices (RFID) for everyday applications. We see them as ID cards that provide access to a building or area, automatic collection of money for tollways, and as the theft-prevention clips tagged onto new clothes. The medical profession in the United States is thought to spend about $90 million each year on RFID devices and systems, with expenditures expected to climb to about $2 billion within the next 10 years.

In spite of all the conveniences and safety measures provided by these devices, they are known to interfere with defibrillators and implantable pacemakers. Less is known, however, about how the RFID technology affects the many devices and equipment systems used in an intensive care unit (ICU).

An assessment of the safety of these devices in a typical ICU patient room was recently conducted by researchers at Vrije University, in Amsterdam, the Netherlands. Led by Remko van der Togt, MSc, the team studied the action of two types of RFID systems - an active system, which requires batteries and can transmit information from one device to another, and a passive system, which operates without the use of batteries and requires an FRID reader to retrieve information.

Each of 41 commonly used medical devices was submitted to 3 tests for electromagnetic interference (EMI). Each incidence of EMI was categorized as light, significant, or hazardous, based on the degree of adversity in the ICU the EMI generated.

Of the total 123 EMI tests conducted, 34 incidences occurred. Of these 34 incidences, 10 were categorized as light, 2 were significant, and 22 were categorized as hazardous to the safe and effective operation of the medical device under assessment. The passive RFID signals caused 17 of the 22 hazardous EMIs and a total of 63% of total EMIs. The closer the distance between the RFID device and the medical equipment, the higher the number of hazardous incidences.

Some of the hazardous EMI events involved mechanical ventilators switching off and changing settings, syringe pumps stopped, external pacemakers malfunctioned, dialysis machines shut down completely, and interference with electrogram readings.

In light of the EMIs documented in this study, the research team suggests closer scrutiny of any RFID systems used in a medical setting. Most of the RFID systems in use today were not designed to be used specifically in a medical setting and international industry standards for the safety of these devices may be in order.

The June 25 issue of the Journal of the American Medical Association (JAMA) carries the full details of the study.