If you have had a pacemaker or an ICD fitted you may already be aware that you need to be wary of certain things when choosing new electronics - other than the obvious how good the camera is and whether it is good value for money.

One important thing to consider is the strength of the magnets built into the device. If these are above a certain limit they can interfere with the functions of pacemakers and defibrillators.

For this reason it seems that such patients should avoid the iPhone 12. Researchers at the Henry Ford Hospital in Detroit (USA) have revealed a case in which an iPhone 12 placed directly over the left side of a patient's chest caused his implanted Medtronic defibrillator to stop working. The implanted device resumed its work as soon as the iPhone was removed from the site.

iPhone 12 pacemaker

This particular study only observed a single case with a limited combination of devices - so it is therefore only the beginning of scientific research on the subject of "iPhone 12 interference".

Apple admits in its support documents that patients with implants should be aware of the risk of interference from the iPhone: "The iPhone contains magnets as well as components and radio elements that generate electromagnetic fields. These magnets and electromagnetic fields can interfere with medical devices such as pacemakers and defibrillators."

However, the advice continues: "Although all iPhone 12 models contain more magnets than earlier iPhone models, no higher risk of magnetic interference with medical devices is to be expected than with earlier iPhone models."

In documents known to us, Apple does not state the strength to which the built-in magnets generate the magnetic field in every iPhone model.

In a somewhat broader study, the researchers at Charité Berlin found that at least the Apple Watch in combination with an iPhone (6) does not interfere with implanted pacemakers and defibrillators.

This article originally appeared on Macwelt. Translation by Karen Haslam.