iPhone 12 magnets deactivating implanted defibrillators in cardiac patients | Hacker News Reader

iPhone 12 magnets deactivating implanted defibrillators in cardiac patients

medmalreviewer.com

35 pointsefunkem13 comments

I have an ICD for Brugada Syndrome, which is being replaced on Monday due to battery failure.

Warnings about strong magnets are standard with them. In fact we're advised to use speaker-phone or headsets if possible, as holding mobile phones to the left ear may disable the device.

I also have authority to bypass many security scanners as I'm disabled (as in my device is in "stupid mode" which means no cardioversion or defibrillation) whilst within them.

So this is old news, at least to those of us with ICDs. There's no way we put anything magnetic or that produces EM fields in a left hand shirt pocket.

Thanks for sharing your first hand experience, and best wishes for your procedure.

Are you aware of the reasons that magnets can disable the device? Are the magnets inducing some current that overloads some high gain, non-invasive, sensing going on, for detecting the rhythm?

Hear you can see a teardown of an implant.

https://youtu.be/sNW3Xqtgkus?t=708

Here is a reed switch which has a sole purpose of stopping the device in presence of a magnet.

The iPhone 12 User Guide warns about this.

From the online version at https://support.apple.com/guide/iphone/important-safety-info...:

>Medical device interference iPhone contains magnets as well as components and radios that emit electromagnetic fields. These magnets and electromagnetic fields may interfere with medical devices, such as pacemakers and defibrillators.

>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.

>Consult your physician and medical device manufacturer for information specific to your medical device and whether you need to maintain a safe distance of separation between your medical device and iPhone. There are many types of medical devices, and manufacturers often provide recommendations on the safe use of their devices around wireless or magnetic products to prevent possible interference. If you suspect iPhone is interfering with your medical device, stop using iPhone.

> When carried in a front shirt pocket.

How about jacket pocket, how close/strong the magnet needs to be to deactivate the device?

To me it seems that iPhones have gotten big enough to be really impractical to carry in a shirt pocket.

Medtronic et all need to do basic due diligence, this is similar to simply walking through a metal detector as well

Patients with an ICD have a special ID card that allows them to bypass metal detectors and security scanners, as our devices are disabled whilst within them.

This is 100% on the medical device manufacturer..

Who designs a medical device that doesn't authenticate commands?!? The command to suspend operation should come from a practicioners terminal, directed at the patients device, and have mutual authentication. It should not be a reed switch and magnet.

If the device is malfunctioning due to say a break in a ventricular lead, patients can be shocked every 40 seconds as the ICD tries to restart the heart. So the magnet switch allows fast and easy deactivation without knowing keys.

Remote adjustment and monitoring over wi-fi does require two-way keys, which is a good thing.

Note I have an ICD for Brugada Syndrome. Come the robot rebellion I'm already on their side as a cyborg!

So you are certain that the higher chance that medical personnel isn't carrying the proper terminal with the proper keys is not an issue in comparison?

They needed to have a quick, cheap, simple, easy way to let any doctor reset the pacemaker to a known-good state. I can totally understand why they went for this.

Apple should have done basic testing before releasing this in the wild with plans to sell hundreds of millions of these devices. At that large scale, you must consider all kinds of users.

And pacemaker usage is relatively quite common nowadays. I'd be surprised if nobody directly involved in magsafe development had a pacemaker installed.

An ICD is a bit more drastic than a pacemaker. They do have a pacemaker-like mode, called overpacing that tries to slow down tachycardia, but their main function is delivering shocks to reset life-threatening arrythmias or to defibrillate in the case of ventricular or atrial fibrilation. ICDs are also much larger than pacemakers, as they have to have much larger batteries and capacitors.

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