Life Saving Therapy Inhibition by Phones Containing Magnets | Hacker News Reader

Life Saving Therapy Inhibition by Phones Containing Magnets

heartrhythmjournal.com

106 pointsmmoez62 comments

I'll give some context here, since I put magnets on people's pacemakers fairly often. Magnets for at least 10 years now is a standard, controlled way to trigger a secondary mode in a pacemaker/defibrillator. Almost always, if the device has both pacemaking and defibrillating capability, the magnet will turn off the ICD (although it is possible to program other behaviors). This allows clinicians to easily stop a patient from being defibrillated inappropriately. That sort of thing could happen during malfunction, electrical interference from cautery tools during surgery near the device, or refractory shockable rhythms.

If there is no defibrillating capability, magnets usually (although not always) put the device into an asynchronous mode. This presents the (extremely unlikely) risk of something serious, like R-on-T, where an electric pulse could be sent to the heart at exactly the wrong time, leading to a life-threatening arrhythmia. More commonly, it means the heart is less effective at pumping blood but probably still within allowable, if not optimal for long periods of time, output.

In both cases, unless the device is programmed strangely, the device resumes normal function when removing the magnet. However, there's the theoretical risk of some sort of malfunction-- so when switching modes with a magnet my practice is to refer patients to getting their devices checked out afterwards. Obviously, if something triggered the "magnet mode" surreptitiously, it may not be noticed until some time later, particularly in patients who are not being actively followed by medical care.

I didn't mention it's actually kind of difficult to getting a magent over these things. I generally tape it over the area that the pacemaker is in, but you have to watch for it moving because, well, it's hard to stick something on somebody's skin. Pacemakers are generally put in the left upper chest, sort of between the nipple and the clavicle. The idea you should have is-- well-- it's not easy to trigger this even with a purpose-built magnet in a slightly-higher-then normal breast pocket. But, still possible of course, and the results could be disastrous, particularly in the event of a malfunction.

The practice of using magnets is kind of universally and internationally understood by medical practitioners and device manufacturers. Which means, transitioning away could cause some harm just by medical errors. I don't think a solution to this is particularly easy, although many devices now get regular interrogations which would show if iPhones actually are triggering the mode switch. Which sort of means, iPhone "interference" could happen but probably isn't really happening as far as anyone knows.

My company’s decides can also be reset with a magnet. But the magnet has to be quite strong. I have never tried it but I would doubt that a phone is strong enough.

Reminds me of the lady who had to be held upside down to live.

https://www.discovermagazine.com/health/vital-signs-the-woma...

It's worth noting that almost anything with a magnetic field can interfere with a pacemaker, for instance induction hobs. Given the pervasiveness of, well, magnets (!), it's probably worth investing in pacemaker research which takes this into account ...

People don't tend to hug their hobs though...

Hobs output >2 kW, phones just... don’t (edit: i.e range of magnetic field is longer)

I'd expect the "receiver"/pot to deform the field enough as to not matter anymore at those distances. Plus, inductive hobs around here tend to detect the presence of a pot and not just try pumping 2kW of energy into "nothing". And you're comparing a dynamically pulsed EM field with the static M field of the alignment magnets - they might be able to heat the reed, but might just not be able actually trigger it (edit: to clarify, that's my guess; I'd expect manufacturers of either devices [ICDs and hobs] to test for potentially lethal problems).

How many people put their phone in their "upper pockets"? Or even have "upper pockets"?

Many men?

If you are wearing a suit, a smartphone makes the trouser pockets bulge a lot, so it's common to keep it in your shirt pocket or jacket inside pocket - Both of which is next to your heart.

The FDA [1] advises "don’t carry the phone in a shirt or jacket pocket directly over the pacemaker." as well as the American Heart Association [2] "Avoid keeping your cell phone in your front chest pocket."

1: https://www.fda.gov/radiation-emitting-products/cell-phones/... 2: https://www.heart.org/en/health-topics/arrhythmia/prevention...

They can advise as much as they want, people just do it anyways.

Same with smoking, drinking, taking drugs, etc.

One hopes people with a device keeping them alive would have an incentive to follow instructions, especially if it doesn't involve addictive substances. They also get told to avoid metal detectors, and they know to do this, so it's probably, hopefully, an easy habit to change

And quite a lot of shirts do as well.

Perhaps it is time for the codpiece to make a comeback in male business attire, updated for modern times to include a phone pouch.

The CodCo JunkKeeper™ Tactical Codpiece features heavy duty military-grade nylon webbing, patented SafeSack™ zipper technology, hammer loop, tape measure holster, and copper mesh Faraday-caged phone pocket to keep your swimmers largely unmutated!

I just realised after posting this that I wear a denim battle vest 99% of the time and this does in fact have an upper pocket. Oops.

You mean the one the pocket protector goes in with your drafting pencil and calculator (well, phone in this day and age)?

My grandfather always does.

He doesn't have a pacemaker, but it may not be as unreasonable of a thing as you might assume.

I do. I don't leave it there generally, but its often easier to get my phone in and out of my shirt pocket when I am seated, crouched, or otherwise actively engaged with something and I don't want to stand up.

You mean like in an inside jacket pocket in parts of the world where it actually gets cold? A lot.

Winter coats very often have upper pockets and they are perfect for big smartphones.

A lot of newer (like, last 5-6 years?) jackets have an outer upper chest pocket.

ex: https://oldnavy.gap.com/browse/product.do?pid=3397220020504&...

It's the most convenient place for a phone on your person.

Easier than pants pockets if you're sitting down. No fumbling with inside jacket pockets. And you can use your "normal" jacket pockets to keep your hands warm without worrying about your phone falling out.

Or, you know, a fridge magnet when carried on a pocket

Hey, cool idea, if I put a small steel plate on the other side, I can wear my favourite fridge magnets instead of pins! Lucky I don't have a pacemaker...

It isn't hard to make them triggered a different way, it is that it is hard to make them reliable enough and triggered a different way. They are designed to be triggered this way because it makes them simple. They are hard to service (requires surgery) and need to be triggered reliably when they are bring triggered. To achieve this, they are made as simply as possible, so have a simple trigger mechanism. Users of them are then told that they have to avoid this situation, by being very careful. One of the instructions anyway is to not keep a phone near them, because of concerns about RF interference. It isn't a case of making another way to trigger pace-makers, it is a case of making a way that is extremely unlikely to fail to work and will remain like that for decades, and where equipment to do it is very cheap. It will then take decades for there not to be people with these devices walking around. If they are changed to work a different way, you also need to equip hospitals around the world with a way to trigger them. Basically, it is really impractical, and it is not as much of a problem as you might think because users should already be hyper aware of the danger of this. Anything you do to change it has a huge risk of killing them because of failing to work if it turns out to be even a tiny bit less reliable after the devices have been inside people for years.

Another example of a device that would be a problem like this is my watch. Jewelry that would have similar problems is also common. Things which would be a problem if put close enough are everywhere, but this is always going to be an issue with something like this that is designed to be triggered easily and extremely reliably, and the decision has previously been taken to educate the tiny number of users of them about it rather than go through the unimaginable logistical effort of changing them now (obviously it was much easier when they were new and rare).

Edit: removed paragraph about making a warning device that I don't think is worth including here.

I don't disagree, but I think you overestimate the ability of people to be careful and aware of their surroundings at all times. Or to even remember that it's an issue. Magnetic fields are invisible. A pacemaker patient I know was unaware of the (potential and low) risk posed by induction hobs. I'm sure this was explained to him, but not everyone is a pacemaker (or magnetic field) expert, nor can we expect everyone to be.

I have a pacemaker. Rule from the start: keep cell phones 6” away from it, minimum, always. Radio interference at very close range is a potential problem.

This article, while interesting and a reminder, just continues the rule.

Tangent: a few years back I got an electric car. After delivery, I read the manual - every other page had warnings for patients with implanted electronic devices. Doc & I were intrigued, discussed it often, and there was never a problem.

Maybe the magnets come out when it crashes.

The traction motors will be brushless, and thus have large permanent magnets in the rotors. I can't imagine there would be significant fields from those magnets in the cabin, but getting a pacemaker or ICD very close to the motors themselves might well pose a risk, and the manual's warnings are likely present partly for that reason and partly out of fear of liability.

At the moment Apple support site states that:

> 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.

https://support.apple.com/guide/iphone/important-safety-info...

It would be interesting to verify this, i.e. compare the risk of interference for iPhone 11 and iPhone 12.

If they're checking for it with all products, you think they'd notice. Is that a standard test for all electronics though, to see if they'd interfere with pace makers?

> Once the iPhone was brought close to the ICD over the left chest area, immediate suspension of ICD therapies was noted which persisted for the duration of the test.

Yeah so if you have a pace maker, try not to put magnets near your heart. The main practical impact for smart phone users with pacemakers seems to be that you shouldn’t carry a phone with a magnet mount in your breast pocket.

The article also mentions WHY pacemakers are so sensitive to otherwise benign levels of magnetism:

> All ICD’s have an in-built switch (Reed switch, Hall-effect sensors, Giant magneto sensitive resistors or coils) which respond to an externally applied magnetic field.

It’s not clear from the article what function these magnetic sensors provide. I suspect it’s either a way for the internal device to interface with an external control circuit or just a minimally invasive off switch.

They turn off/disable the pacemaker. They are used in situations where the pacemaker is not functioning as intended. ERs have ring magnets specifically to activate this designed feature. Imagine if a pacemaker is triggering the heart out of sequence, or if an installed defibulator is constantly shocking the heart. The external magnet is a simple way of turning it off temporarily.

>just a minimally invasive off switch.

Yup. A safety mechanism that has to be low tech. And user training to avoid magnets is safer than a more complicated interface.

The reason this is news is that not all cellphones are magnets, nor is there any obvious indication which are magnets.

IME all recent cell phones contain fairly strong magnets in their speakers. They tend to clog up with iron filings/dust in my workshop.

Speaker magnets tend to be strong but small, meaning they would have to be very close. Thanks s is for attaching a charger, so is likely a much larger magnet, so more likely to be an issue.

Yes, the magnetic sensor allows the implant to be 'suspended' for tests or if other treatments need it 'off' for the duration.

Anything with strong magnets has a warning about not to use near a pacemaker. Does iPhone 12 come with such a warning?

Yes.

https://manuals.info.apple.com/MANUALS/1000/MA1964/en_US/iph...

Then it's fine, thanks.

It took a while for me to parse the title...

So the key takeaway is: if you have a pacemaker or an implanted defibrillator, don't put your phone in your breast pocket? But I imagine people are already told to avoid that, just to minimize the risk of radio interference? Of course, this turns a remote possibility of impacting the functionality into a near-certainty (if the magnet is strong enough).

BTW these iPhones are not the first phones that contain magnets. The Moto Z range, which has been around since 2016, has accessories ("Moto Mods") that are attached magnetically. The magnets are in the accessories, but since one backplate is shipped with the phone, most people will probably have that attached.

Editorialized title. The actual is:

Life Saving Therapy Inhibition by Phones Containing Magnets

The article is about the iPhone 12. Just pointing out that magnets aren’t specific to the iPhone.

The editorialised title is both accurate to the beginning of the article, and more informative. I would have ignored the original title. Thanks to the editorialised title, I now know that magnets can mess with pacemakers.

> The editorialised title is both accurate to the beginning of the article, and more informative. I would have ignored the original title.

I don't understand why dang and other mods justify their gatekeeping when they edit the title to use 'expensive words', like they did here. It makes me feel so frustrated. Stop with the academia-industrial-complex and let people link to articles/papers how they want to. Stop with the PR already (removing 'iPhone').

I think the idea is to trust the author’s judgment and do not change the focus (here: “phones containing magnets” vs “iPhone 12”) of the original article, especially in an attempt to make the title stand out more or get more views.

Because “editorializing” the title introduces biases (either knowingly or unknowingly). Was “iPhone 12” added in the submitted title just to make it more specific, or was it a nudge to bring on the Apple haters?

Who cares about Apple haters? I care that it’s a super common device that a lot of people have and could therefore be dangerous

Just because the title is editorialized doesn't mean that is a bad thing, the first line of the article is:

> The Heart Rhythm Society has issued the following information regarding the use of the new iPhone 12 Series and ICDs.

The original title is, in classic British style, quite understated, some editorializing is justified.

Editorialized is if the title express the posters opinion. It does not. If anything it makes it more clear.

No idea why he is downvoted. He is factually correct as can be seen in merriam-webster and the cambridge dictionary:

https://www.merriam-webster.com/dictionary/editorialize

https://dictionary.cambridge.org/dictionary/english/editoria...

As the title is just more informative, but not expressing an opinion, calling it editorialized is wrong.

And as a matter of fact, because of this comment I just learned a new word and how to use it correctly.

> As the title is just more informative, but not expressing an opinion

What is more informative or less informative (e.g. "phones containing magnets" vs "iPhone 12") could be an opinion itself. The "iPhone 12" title definitely stands out more; at the same time it puts a slightly different focus on the article. I think people here prefer to trust the author and their judgment (as long as the original title isn't open clickbait).

previously: https://news.ycombinator.com/item?id=25677717

The original, full article is

https://www.heartrhythmjournal.com/article/S1547-5271(20)312...

Does anyone know if magsafe is still patented? I checked many many years ago and it was, which was why I couldn't find other vendors offering it, but has that patent somehow last over 20 years?

This is MagSafe on iPhone, a completely unrelated product that happens to have the same name as the old laptop power connectors.

Seems like a failure in pacemaker design? The pacemaker kill switch should simply need much stronger magnets so there is no confusion between mobile phone or the kill switch key.

> The pacemaker kill switch should simply need much stronger magnets

'simply' here is code for 'will require changes, perhaps significant, to therapeutic processes and medical infrastructure in hospitals and other medical facilities across the planet'.

Pacemakers do need to be serviced and replaced every once in a while, so this isn't end of the world scenario. Even better, stronger magnets would work for both "old" and "new" devices, so no need for two "disable" keys.

The point is that it is fairly easy to trigger. This is considered safer than having a hard to trigger mechanism and less user caution, because of greater chance of it failing to be triggered when needed. You could have some sort of complex signal sent that switches them, but it'd make the devices much more complex, and since they are very hard to service, and need to respond when triggered, they are designed to be simple. Users of these devices aren't supposed to have phones near them anyway.

> Users of these devices aren't supposed to have phones near them anyway.

And people are using them anyway.

I understand that the current design was made in a different world, but that doesn't mean that pacemaker design is supposed to stagnate. It definitely can and should be hardened to take into account modern environment.

To spin this in Google's Employee Activist terms (eg, "Data Violence"), Apple's hardware design is Literally™ Engaging in Senicide.

Seems like a big suit incoming

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