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Apple Updates Advice Regarding Magnetic Interference with Implanted Medical Devices

Earlier this year, we reported on concerns that the MagSafe charging technology in the iPhone 12 models could interfere with pacemakers, defibrillators, and similar medical devices (see “Keep the iPhone 12 and Other Magnet-Bearing Consumer Electronics Away from Implanted Medical Devices,” 25 January 2021). At the time, Apple said:

Though all iPhone 12 models contain more magnets than prior iPhone models, they’re not expected to pose a greater risk of magnetic interference to medical devices than prior iPhone models.

Although that text remains intact on the “Important safety information for iPhone” page, Apple has now revised the support document that previously reiterated that advice. In “About potential magnetic interference with medical devices,” Apple continues to acknowledge the possibility of magnetic interference and provides a list of Apple products whose magnets are strong enough to be of concern, including the iPhone 12 and MagSafe accessories, along with some you might not expect, like the Pro Display XDR. It’s a long list, but the key thing to remember is that close contact is what you’re trying to avoid. Apple recommends keeping these products at least 6 inches (15 cm) away from such medical devices or more than 12 inches (30 cm) away if using wireless charging.

What prompted the change? It may have been aimed at heading off criticism. 9to5Mac noted that the American Heart Association reported on a recent study that showed interference between an iPhone 12 Pro Max held close to implantable cardiac devices.

Play it safe. If you have an implanted medical device, keep Apple’s magnet-enhanced products well away. That applies to all sorts of other products that also have magnets—Apple’s not doing anything unusual here. Though the company does love its magnets!

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Comments About Apple Updates Advice Regarding Magnetic Interference with Implanted Medical Devices

Notable Replies

  1. Frak me… just got the new IPP 12.9 and now I hear about this (implanted defibrillator). At least somewhere in the fine print I saw a 6 inch metric… interestingly, having the larger screen means I have it farther away from me (90% of my use is consuming video). After some long hospital stays, I got an aluminum stand just in case, but HAVE been using it a lot while chilling out.

  2. With luck, we’ll see some companies release iPhone cases with magnetic shielding.

    I’ve seen other objects (e.g. badge holders) with such shields, so the magnets don’t interact with external objects. So it should be possible. But even if they are developed, I still foresee problems:

    • No way they’ll be Apple MFI certified. I can’t imagine anything that blocks MagSafe being certified for use with a MagSafe-equipped device. But this is minor and I’m sure most customers won’t care.

    • How to shield the screen. I don’t know if there is a way to make a transparent magnetic shield. Maybe a glass R&D company like Corning could invent one, but I don’t know enough to speculate on that.

      Of course, Apple could do this if they would be willing to make the phone a little thicker. No reason why you couldn’t slip a shield in the case somewhere between the screen and the magnets (either under or over the battery).

  3. The more I think about this, the more I see it being based in their law department, not so much engineering. Far as I know, airport metal scanners put out a substantial magnetic field and I know specifically (I asked) my implant is NOT affected by this. Nor by hand scanners. Could very well be they are only giving themselves some kind of cop-out… the “we told you so.”

  4. Well, there’s a bit of a difference.

    An airport scanner’s field is only used briefly during the scan. I would expect any well designed implant to be able to deal with brief interference from an external magnetic field (assuming there is any interference, of course).

    A phone is different. It has has an array of permanent magnets and it may be near the device for an extended period of time, depending on where you are using/holding/carrying it. For example, carrying it in a jacket pocket may place it right up against a pacemaker, vs carrying it on a belt clip, which is pretty far away.

    If the magnets cause interference (and again, this is an assumption, not a statement of fact), that interference may be present for hours at a stretch. Depending on the device’s design, it might be a problem.

    All this having been said, the distance and configuration of the magnets matters a lot. Apple is using a ring of magnets where adjacent magnets have opposite polarity. (See section 24, Features > MagSafe Attach, of Apple’s accessory design guidelines).

    I assume that by using alternating-polarity magnets, they will cancel each other out after some distance from the device, but I don’t know enough physics to compute what that distance will be.

    Additionally, each individual magnet’s field will be attenuated by a factor that is a cube of the distance (so doubling the distance will reduce the field strength to 1/8).

    Depending on the sensitivity of your device, this may or may not be a practical problem. I would strongly recommend consulting with your doctor about this, just to be sure, since there are enough unknowns that nobody here on TidBITS is going to be able to give a definitive answer.

  5. There are many different types of airport scanners.

    The more modern type (the ones where you need to spread your legs and hold your hands up while a gantry swivels around you) are most commonly mm wave scanners (rarely you’ll encounter backscatter x-ray [usually recognizable because you stand between two large cabinets], no static B field there either) that do not apply magnetic fields at all.

    The older models (where you just walk through) have a constantly on magnetic field, it’s AC though, usually no modulation (unlike those fields used to read out or alter pacemakers and the like) and very weak. AC magnetic field variation induces Eddy currents in electrically conducting objects (metals) which then create B fields of their own that are detected as a perturbation by the scanner. Same principle is applied in the hand-held wands they also employ.

    The airport scanner that’s “only on for a brief period of time” is the x-ray machine used to scan bags. It’s well shielded so that the only dose deposited is to bags going through it. That dose is indeed very low, but of course nevertheless not intended to be applied to a person. Putting a person (or animal) through there is a felony in most countries.

  6. The fact that the scanner is powered all the time doesn’t matter, because you don’t stand in the middle of it for an extended period of time.

    You walk through it once (maybe 2-3 times if the operator asks you to), but that’s it. So it’s still a momentary exposure, unlike magnets attached to your phone, which may be pressed up against your body for hours at a time.

  7. Actually, there is a concern regarding airport scanners. I have a relative with a pacemaker and her cardiologist who handles the PMs issues (major medical school hospital MD) is constantly reminding her of not going through those scanners. She carries a special ID card and is hand scanned at every checkpoint she needs to go through.

    I am surprised Apple doesn’t provide alternatives for people with those devices so they can enjoy the latest technology without being threatened by the magnets. I find it interesting that Apple has worked so hard to promote their watches as an important part of fitness and health monitoring while someone using a sleep app on the watch stands the risk of damage because their arm/watch could fall right next to the implant during their sleep or in other situations. I hope Apple will address this issue; for me I would easily forgo the joy of a magnetic charger if it meant I would be safe to use the technology if I had an implant.

  8. I think that’s the case for many with pacemakers and other implants. It makes little sense to put such people through this type of scanner in the first place. If the scanner is properly calibrated, it will usually alarm and that triggers a ‘manual’ scan (and/or pat-down) anyway, so you might as well start with that right away.

    Fun fact, those old-fashioned walk-through scanners are designed to create false positives at a certain (adjustable) rate and at stochastic intervals. The idea is to make sure that nobody can be certain that not carrying any metals guarantees they won’t get patted down or wanded. So next time one of those machines starts beeping even though you had absolutely nothing on you or in your pockets, don’t even bother trying to explain yourself to the agent. They don’t care, for all they know you’re right. You’re getting a closer inspection either way. It’s not you. Just the way the process has been designed.

  9. So they’re basically slot machines! The TSA could make more friends if periodically someone won a lot of quarters too.

  10. Trust me, I have already written Boston Scientific, the makers of my implant. Going to be interesting to see what they say (I’ll write back here, of course). I only very rarely use the fone, never have it near my chest, non-factor. I DO at time prop my tablet on my stomach watching stuff… it is just outside the 6" zone mentioned. Being a 12.9", I generally do have it farther away than my 9.7" one.

  11. Bingo, heard from Boston scientific… they reiterate the 6" metric, keep any such devices at least 6" away from the implant. They also say they ARE very much aware of the statement from the fruit. I DID think about having them re-locate the implant to my butt, but…

  12. I don’t have a problem that this is relevant to but someone I know does.

    Does anyone know if the impact of bringing one of the Apple devices too close is long lasting?

    That is does the interference only cause problems while the Apple device is close or if the Apple device comes close once the implant is messed up until reset?

  13. I think the real answer is going to depend on the device. While I would like to say that any well-made device will return back to its normally-configured operation when the interference goes away (assuming that the interference actually causes the device to change its behavior), it would be dangerous to assume that this applies to all devices.

    This is definitely a case of “ask your doctor” or “ask your implant manufacturer”.

  14. I have watch and a pacemaker and also wear it on my left wrist. I have not had problems since having pacemaker fitted 18 months ago. I am aware of the problem though

    I have the iPhone 11 Pro Max and am not aware of problems with that


  15. An iPhone 11 doesn’t have the MagSafe magnets, so I wouldn’t expect it to cause a problem.

    A Watch has a magnetic connection for the charger, but if it is on your wrist, it probably doesn’t spend a lot of time within 6" of the pacemaker.

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