High field strength magnets are used in some consumer electronic devices, such as cell phones and smartwatches. According to recent research, consumer electronics with high field strength magnets may cause certain implanted medical devices to go into “magnet mode” and suspend normal operations until the magnet is moved away from the medical device.
A new study backs up the FDA’s recommendation that patients keep any consumer electronic device that could cause magnetic interference, such as cell phones and smartwatches, at least six inches away from implanted medical devices, particularly pacemakers and cardiac defibrillators.
Following reports of smartphone and watch interference with implanted medical devices, investigators affiliated with the Center for Devices and Radiological Health (CDRH) at the US Food and Drug Administration conducted a study that supports the FDA recommends that patients keep any consumer electronic devices that may create magnetic interference, including cell phones and smartwatches, at least six inches away from implanted medical devices, particularly pacemakers.
As a result of these findings, we are taking steps to provide information to patients and healthcare providers so that they are aware of potential risks and can take simple proactive and preventive measures such as keeping consumer electronics, such as certain cell phones and smartwatches, six inches away from implanted medical devices.
Seth J. Seidman
Following reports of smartphone and watch interference with implanted medical devices, investigators affiliated with the US Food and Drug Administration’s Center for Devices and Radiological Health (CDRH) conducted a study that supports the FDA’s recommendation that patients keep any consumer electronic devices that may create magnetic interference, including cell phones and smartwatches, at least six inches away from implanted medical devices, particularly pacemakers.
Their findings were published in Elsevier’s Heart Rhythm, the official journal of the Heart Rhythm Society, the Cardiac Electrophysiology Society, and the Pediatric & Congenital Electrophysiology Society.
“Ensuring the safety of our nation’s medical devices is a cornerstone of our consumer protection mission, especially as technology advances,” said lead investigator Seth J. Seidman, MS, Research Electrical Engineer and EMC Program Advisor with the CDRH.
“As part of this work, the agency reviewed recently published articles describing the possibility that certain newer cell phones, smartwatches, and other consumer electronics equipped with high field strength magnets may temporarily interfere with the normal operation of implanted electronic medical devices such as pacemakers and implantable defibrillators. We decided to conduct our own testing based on our review to confirm and help inform appropriate recommendations for patients and consumers.”
Cardiac implanted electronic devices are designed to help with heart rhythm problems, such as slow or fast heart rates. Implantable pacemakers and cardioverter defibrillators (ICDs) have a “magnet mode” that is used when a patient is undergoing a procedure that may cause electromagnetic interference, or when the device must be suspended for medical treatment. However, this feature can be accidentally triggered by strong magnetic fields greater than 10G, which can change how the device works and cause serious harm to the patient.
Historically, magnets powerful enough to activate this magnet mode were large and visible, such as stereo speakers or electronic motors in cordless tools. However, with the introduction of small rare-earth magnets, strong magnetic fields can now be found in headphones, door locks, and small phone speakers.
The magnetic field output of all iPhone 12 and Apple Watch 6 models was tested at various distances from the devices by the researchers. They discovered that all the devices have static magnetic fields in close proximity that are significantly greater than 10G, which is high enough to put implanted cardiac devices into magnet mode. When a separation distance of six inches or greater is maintained, however, the phones and watches will not activate magnet mode.
“As a result of these findings, we are taking steps to provide information to patients and healthcare providers so that they are aware of potential risks and can take simple proactive and preventive measures such as keeping consumer electronics, such as certain cell phones and smartwatches, six inches away from implanted medical devices and not carrying consumer electronics in a pocket over the medical device,” Mr. Seidman advised.
“We believe the risk to patients is low, and the agency is currently unaware of any adverse events related to this issue. The number of consumer electronics with strong magnets, on the other hand, is expected to grow over time. As a result, we recommend that people who have medical devices implanted consult with their healthcare providers to ensure they understand the potential risk and the proper techniques for safe use. The FDA will continue to monitor the effects of consumer electronics on medical device safety”, Mr. Seidman made the observation.
