with iPhone 12 beware of implantable pacemakers and defibrillators

The Italian Istituto Superiore di Sanità (ISS), which many people may have become aware of in the last couple of years on the occasion of the Covid pandemic, in a report recently published by the magazine Pacing and Clinical Electrophysiologycame to the conclusion that it is necessary to keep some distance between iPhone 12 and electronic devices such as pacemakers and implantable defibrillators, to avoid the ‘rare’ possibility that the magnet in the phone can activate the magnetic switch on these devices.

In particular, the study describes how, in rare cases, “if an iPhone 12 model smartphone is kept less than one centimeter from the heart, the magnet present in it can activate the magnetic switch of pacemakers and implantable defibrillators”. It is therefore “It is very important to follow the instructions provided by the manufacturers of medical devices and by Apple itself that a distance of at least 15cm must be maintained between a mobile phone and the device” reads the note of the ISS.

Which ‘magnet’ in the iPhone 12 is it? In 2020, together with the iPhone 12 seriesApple introduced the system MagSafe on the iPhone, which through a series of magnets arranged around the wireless charging coil inside the iPhone has paved the way for new accessories that connect easily, magnetically, to the phone (such as cases, wallets and battery packs). Here, these magnets can in some rare cases become a problem for people who have pacemakers and defibrillators implanted in the body.

The ISS study was launched a year ago, after Federica Censi, Giovanni Calcagnini, Eugenio Mattei, Graziano Onder of the Department of Cardiovascular, Endocrine-Metabolic and Aging Diseases of the Istituto Superiore di Sanità published a notes that some data presented in the scientific literature and then resumed by the non-specialized press have brought to light the possibility that the magnet used in the Apple iPhone 12 smartphone could activate the magnetic switch present in the defibrillator, deactivating the shock function necessary in case of ventricular arrhythmia and consequently preventing the defibrillator from applying the prescribed therapy in case of arrhythmia.

Apple has seen fit to point out in the instructions for use that “Medical devices such as implanted pacemakers and defibrillators may contain sensors that can react to magnets and radio frequencies when in close contact. To avoid potential interactions with these devices, keep your iPhone and MagSafe accessories at a safe distance from the device ( more than 15 centimeters away, or more than 30 centimeters if wireless charging is activated) “.

The ISS was the first to evaluate the magnetic interference of the iPhone 12 and its accessories in the laboratory MagSafe on a representative sample of the current Italian market of implantable pacemakers and defibrillators, including the subcutaneous defibrillator. In addition, for the first time, magnetic interference phenomena have been accurately correlated with the magnetic field levels measured around the iPhone 12. Researchers evaluated implantable pacemakers and defibrillators from leading global manufacturers (Abbott, Biotronik, Boston Scientific, Medical , Medtronic, Microport), using a heart rate simulator. The results showed that, in some cases, the magnet in the iPhone 12 can inadvertently activate the magnetic switch in the sample of implantable pacemakers and defibrillators that was evaluated. The phenomenon was observed up to a maximum distance of 1cm. The ISS points out, however, that the activation of the magnetic mode has been observed only in some specific positions of the iPhone with respect to the device and that in most of the positions the phenomenon does not trigger.

The magnetic field generated by the magnet inside the iPhone 12, measured by the ISS researchers, was found to be greater than the value to which pacemakers and implantable defibrillators must be immune. “The unwanted activation of the magnetic switch can rarely happen even in other situations of common life in the presence of magnets but given the widespread use of the iPhone 12 and the habit of putting the smartphone in the pocket, the involuntary activation of the mode magnet caused by iPhone 12 may be less rare “ the study authors point out.

It is important to underline that the data available to date are limited, that the functions associated with the activation of the magnetic switch of pacemakers and defibrillators may vary depending on the manufacturer and model of device. Furthermore, the problem has so far only been reported for Apple’s iPhone 12, but it is not excluded that it may also affect other models. For this reason, the ISS deems it necessary to warn patients about this unique feature of the iPhone 12 and to evaluate this potential risk in the future for new smartphone models.

Below we leave you with the note reported by the ISS in February 2021 on how pacemakers and defibrillators work and possible interference.

Pacemakers and implantable defibrillators are medical devices that deliver an electrical pulse to manage certain cardiac arrhythmias. Pacemakers and implantable defibrillators have always been equipped with magnetic switches that are activated by the external application of magnets (magnets), in order to easily manage some functions of these devices. The magnets used in the clinical setting have a shape that allows for proper positioning over the implantation site. Once positioned, the magnetic switch is activated and the device enters a particular operating mode. Activation of this mode is immediate and deactivation occurs by simply removing the magnet. The functions associated with this mode are described in the device manuals and typically allow switching to asynchronous pacing mode in the pacemaker and suspension of the shock function in the event of ventricular arrhythmia or detection of arrhythmias in the implantable defibrillator. These modes are very useful in particular circumstances, such as during device programming or in the case of surgical interventions where there is a risk of interference caused for example by electrosurgical units. These modalities, if activated inadvertently or outside a controlled environment and without the supervision of clinical personnel, introduce a potential risk to the wearer of an implanted device. In real life, the possibility of a static magnetic field affecting a pacemaker or defibrillator is remote, as a wearer of an implantable pacemaker or defibrillator is unlikely to unknowingly place a magnet on the implant site. However, given this characteristic of “feeling” static magnetic fields above a certain intensity (typically greater than 1 mT, about 40 times higher than the value of the Earth’s magnetic field), the manuals of these devices make it explicit the need not to approach to sources of high static magnetic fields, such as those present in the vicinity of high-power loudspeakers, passageways for controlling people, magnetic clips for bags and cases. In recent years, the introduction of the wireless induction charging mode to recharge the battery of smartphones and smartwatches has led to the use of magnets inside the charging base, to ensure the positioning and correct alignment between the charger and the smartphone. In the iPhone12 smartphone, the wireless charging mode is achieved using a magnet positioned in the smartphone itself, for correct alignment with the charger. The presence of the magnet on the smartphone made the possibility of inadvertently activating the magnetic switch of the devices less remote.

Leave a Comment