Apple’s iPhone 12 and Apple Watch 6 can disrupt medical implants such as pacemakers if they are held too close to the body, warn researchers.
Such implants often feature a “magnet mode” designed to be deliberately triggered with a strong magnet when a person is undergoing a procedure where interference is possible, such as an MRI scan.
Internal defibrillators in magnet mode won’t deliver lifesaving shocks, while pacemakers will drive the heart at a continuous pace without sensing the patient’s own rhythm. Both of these situations can cause harm or even death.
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The dangers of magnets accidentally triggering magnet modes have long been recognised, but it used to be the case that only large magnets such as those found in electric hand tools or speakers were strong enough. With the advent of mobile telephones and strong rare earth magnets used in everything from headphones to power cords, the risk grew, and by the 1990s it became clear that a host of consumer electronics could potentially affect people with these implants.
As a result, the US Food and Drug Administration (FDA) recommends that users keep consumer electronics at least six inches (15 centimetres) away from their implanted devices.
at the FDA’s Center for Devices and Radiological Health and his colleagues performed experiments on the latest Apple smartphones and watches to see whether that guidance was still appropriate or necessary.
The team tested the strength of the magnetic field of all iPhone 12 and Apple Watch 6 models at varying distances with a gauss meter. Implants typically require a magnet strength of 10 gauss to trigger magnet mode, and the experiments revealed that an iPhone 12 Pro Max can create a field of 394 gauss at a distance of 1 millimetre. This drops to a safe 7.8 gauss at a distance of 21 millimetres.
All other iPhone 12 models and the Apple Watch 6 were also found to be able to create sufficiently strong fields to trigger magnet modes.
Apple declined to be interviewed, but the company does include guidance in its iPhone and Apple Watch user guides that warns about potential magnetic interference with medical devices.
Heart Rhythm
