Engineering news
Investigators from the US Food and Drug Administration’s Center for Devices and Radiological Health (CDRH) found that consumer electronic devices may create magnetic interference. The body now recommends that people keep phones and watches at least six inches away from implanted medical devices, in a paper published in the journal Heart Rhythm.
“Ensuring the safety of our nation’s medical devices is a cornerstone of our consumer protection mission, especially as technology continues to advance,” explained lead investigator Seth J. Seidman, 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, 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 problem stems from the ‘magnet mode’ included in many pacemakers and defibrillators, which is 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. But this mode can be triggered accidentally by strong magnetic fields – with potentially serious risks to the patients.
In the past, magnets strong enough to trigger this mode were large enough to be easily identifiable, but smaller rare-earth magnets now mean strong magnetic fields can be found in headphones, door locks and smartphone speakers.
Researchers tested the magnetic field output of iPhone 12 and Apple Watch 6 models at varying distances from the devices, and found that all of them had static magnetic fields significantly greater than 10G in close proximity – high enough to place implanted cardiac devices into magnet mode. But, as long as a six inch distance was kept between the device the mode was not triggered.
“Because of these results, we are taking steps to provide information for patients and healthcare providers to ensure they are aware of potential risks and can take simple proactive and preventive measures like keeping consumer electronics, such as certain cell phones and smart watches, six inches away from implanted medical devices and not carrying consumer electronics in a pocket over the medical device,” advised Seidman.
“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. 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,” added Seidman.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.