ROCKVILLE, MD--The Center for Devices and Radiological Health of the FDA has recently released a warning that the operation of certain medical devices, including pacemakers, implantable cardioverter/defibrillators, and spinal cord stimulators may be affected by the electromagnetic fields produced by anti-theft systems and metal detectors.
Anti-theft systems, also called electronic article surveillance (EAS) systems, are used in a wide variety of settings, including supermarkets, shopping malls, and libraries. They typically consist of one or two columns placed opposite each other near entrances and exits. Several technologies are currently on the market, but generally an electromagnetic detection field is produced between the two columns and an alarm sounds if an article with a special tag is carried between the columns.
Metal detectors for airport and facility security applications can be either portals that a person walks through, or can be hand-held "wands" that are passed over a person´s body. Metal detectors use various technologies involving magnetic fields to detect the presence of metal.
In the past 10 years, the FDA has received 44 adverse event reports where EAS systems and metal detectors appeared to interfere with the routine function of implantable pacemakers, implantable cardioverter/defibrillators, and spinal cord stimulators. Similar events have also been reported in medical literature. The FDA believes that EAS systems or metal detectors can potentially interact with other electronic medical devices as well.
For pacemakers, the types of responses to the interference reported were: shifts in pacing rate; alteration to programmed pacing therapy; loss of or near loss of consciousness; and chest pain. Two patients with implantable cardioverter/defibrillators inappropriately received shocks to the heart. Seventeen patients reported overstimulation from implanted spinal-cord stimulators.
The FDA notes that the number of reported significant patient injuries is very low. Nevertheless, the following information and recommendations have been issued to help patients prevent or minimize any adverse effects.
Interactions with EAS systems and metal detectors are unlikely to cause clinically significant symptoms in most patients. However, to be on the safe side, patients with electronic medical devices, particularly those who are dependent on the device (e.g., pacemaker dependent), may wish to take some simple precautions:
- Be aware that EAS systems may be hidden/camouflaged in
entrances and exits where they are not readily visible in many
- Do not stay near the EAS system or metal detector longer than
is necessary and do not lean against the system.
- If scanning with a hand held metal detector is necessary, warn the security personnel that you have an electronic medical device and ask them not to hold the metal detector near the device any longer than is absolutely necessary; or you may wish to ask for an alternate form of personal search.