Originally published at: Apple Updates Advice Regarding Magnetic Interference with Implanted Medical Devices - TidBITS
Concerns about MagSafe in the iPhone 12 interfering with pacemakers, defibrillators, and other implanted medical devices surfaced earlier in the year. Apple now cautions that many of its magnet-using products could cause problems for such devices.
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.
With luck, weâll see some companies release iPhone cases with magnetic shielding.
Iâve seen other objects (e.g. badge holders) with such shields, so the magnets donât interact with external objects. So it should be possible. But even if they are developed, I still foresee problems:
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No way theyâll be Apple MFI certified. I canât imagine anything that blocks MagSafe being certified for use with a MagSafe-equipped device. But this is minor and Iâm sure most customers wonât care.
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How to shield the screen. I donât 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 donât 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 couldnât slip a shield in the case somewhere between the screen and the magnets (either under or over the battery).
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 âwe told you so.â
Well, thereâs a bit of a difference.
An airport scannerâs 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 deviceâs 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 Appleâs 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 donât know enough physics to compute what that distance will be.
Additionally, each individual magnetâs 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.
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 youâll 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, itâs 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 thatâs âonly on for a brief period of timeâ is the x-ray machine used to scan bags. Itâs 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.
The fact that the scanner is powered all the time doesnât matter, because you donât 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 thatâs it. So itâs still a momentary exposure, unlike magnets attached to your phone, which may be pressed up against your body for hours at a time.
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 doesnât 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.
I think thatâs 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 âmanualâ 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 wonât 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, donât even bother trying to explain yourself to the agent. They donât care, for all they know youâre right. Youâre getting a closer inspection either way. Itâs not you. Just the way the process has been designed.
So theyâre basically slot machines! The TSA could make more friends if periodically someone won a lot of quarters too.
Trust me, I have already written Boston Scientific, the makers of my implant. Going to be interesting to see what they say (Iâll 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.
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, butâŚ
I donât 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?
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 âask your doctorâ or âask your implant manufacturerâ.
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
Carol
An iPhone 11 doesnât have the MagSafe magnets, so I wouldnât expect it to cause a problem.
A Watch has a magnetic connection for the charger, but if it is on your wrist, it probably doesnât spend a lot of time within 6" of the pacemaker.