Dutch researchers have published a study in the Journal of the American Medical Association (JAMA) reporting that RFID technology can interfere with medical devices in hospitals, posing a potential hazard to patients. RFID is increasingly used in hospital settings to track medical assets, staff and patients.

The article, published on June 25, describes testing conducted at the Academic Medical Center at the University of Amsterdam in the Netherlands using active 125kHz and passive 868MHz RFID systems to check for electromagnetic interference (EMI) with 41 medical devices.

Out of a total of 123 tests (each device was tested three times), researchers reported 34 EMI incidents. Twenty-two were classified as hazardous, two as significant, and 10 as light. Passive 868MHz signals induced a higher number of incidents (63%) compared with active RFID technology (20%).

The devices tested included mechanical ventilators, infusion pumps, dialysis devices, defibrillators, and anesthesia equipment.

According to the report, the hazardous incidents included stoppage of syringe pumps, malfunctions in external pacemakers, and switch-off in mechanical ventilators.

"The lack of standardization of RFID in health care permits RFID systems originally designed for logistics to enter the medical arena on the basis of requirements such as the range at which medical tagged items or individuals are to be detected," the authors of the report stated. "The intensity of electronic life-supporting medical devices in this area requires careful management of the introduction of new wireless communications such as RFID."

The researchers recommended required on-site EMI tests for RFID deployments, along with updated international standards. There is currently no standard for RFID and other tracking systems used in hospitals, and the systems that are currently deployed operate using a wide variety of frequencies and technologies.

The RFID industry has pointed out that the tests were conducted under "worst case scenario" conditions, using the equipment's maximum power settings. Hospitals and systems integrators should test equipment for potential interference, and maintain the proper power settings for RFID readers.

In an online column, Bert Moore, editor of AIM Global's RFID newsletter, noted that the testing methodology was valid, but "does not necessarily represent real world issues. Thus, while adverse effects were observed, the conditions under which they were created were not those likely to exist in an actual healthcare setting." AIM Global is the trade organization for the automatic identification industry.

There are no recorded instances of patients being injured because of the use of RFID technologies in a hospital. The testing in Amsterdam did not include high-frequency RFID or Wi-Fi-based systems.

After the report was published, a number of vendors that provide asset and patient tracking technology to hospitals issued statements affirming that their equipment had been tested and designed to avoid interference with medical equipment.

RadarFind, which supplies 900MHz real-time location systems (RTLS) to hospitals, noting that the high power levels used in the tests are known to cause interference issues.

"Because RTLS systems use ultra-low power levels, they are harmless to electronic equipment and people," said RadarFind CTO Stephen Jackson.

Last year, the U.S. Food and Drug Administration (FDA) tested RFID for its effects on implantable medical devices and defibrillators, but found that HF and UHF RFID equipment caused minimal reactions. The FDA is currently performing additional tests on RFID with medical equipment.

The FDA is also considering RFID for use in its unique device identification system for medical devices.