Smartphone

Keep smartphone, smartwatches 6 inches away from pacemakers, ICDs

By EMS1 Staff

PHILADELPHIA — Research supports FDA recommendation to keep consumer electronic devices like smartphones and smartwatches at least six inches from implanted medical devices, particularly pacemakers and cardiac defibrillators.   

After reports of smartphone and watch interference with implanted medical devices, investigators affiliated with the Center for Devices and Radiological Health (CDRH) at the U.S. Food and Drug Administration conducted a study on the magnetic field output of all iPhone 12 and Apple Watch 6 models at varying distances from the devices. The researchers found, according to a Heart Journal press release, that all the devices have static magnetic fields significantly greater than 10G in close proximity, which is high enough to place implanted cardiac devices into magnet mode. However, when a separation distance of six inches or more is maintained, the phones and watches will not trigger magnet mode. 

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Cardiac implanted electronic devices are intended to support heart rhythm disorders, such as slow or fast heart rates. Implantable pacemakers and cardioverter defibrillators (ICDs) include a “magnet mode” designed to be used when a patient is undergoing a procedure where electromagnetic interference is possible, or when suspension of the device is necessary for medical treatment. However, this feature can also be triggered accidentally from strong magnetic fields greater than 10G, which can change how the device works and could result in serious harm to the patient.  

Historically, magnets strong enough to trigger this magnet mode were large and identifiable, such as stereo speakers or electronic motors in cordless tools. With the advent of small rare-earth magnets, however, strong magnetic fields can be found in headphones, door locks, or small phone speakers.  

“Ensuring the safety of our nation’s medical devices is a cornerstone of our consumer protection mission, especially as technology continues to advance,” said Seth J. Seidman, MS, Research Electrical Engineer and EMC Program Advisor with the CDRH and lead investigator. “As part of this work, the agency reviewed recently published articles describing the possibility that certain newer cell phones, smart watches and other consumer electronics with high field strength magnets may temporarily affect the normal operation of implanted electronic medical devices, such as pacemakers and implantable defibrillators. Based on our review, we decided to conduct our own testing to confirm and help inform appropriate recommendations for patients and consumers.” 

The CDRH is providing information to patients and healthcare providers about the potential risks and preventive measures, like keeping consumer electronics six inches away from implanted medical devices and not carrying consumer electronics in a pocket over the medical device. 

“We believe the risk to patients is low and the agency is not aware of any adverse events associated with this issue at this time,” Seidman added. “However, the number of consumer electronics with strong magnets is expected to increase over time. Therefore, we recommend people with implanted medical devices talk with their healthcare providers to ensure they understand this potential risk and the proper techniques for safe use. The FDA will continue to monitor the effects of consumer electronics on the safe operation of medical devices.” 

Read the full article, “Static magnetic field measurements of smart phones and watches and applicability to triggering magnet modes in implantable pacemakers and implantable cardioverter defibrillators.”