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FDA Data Confirm Smartphone Interference With Cardiac Devices

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SiliconWizard:

--- Quote from: m98 on August 30, 2021, 10:23:46 pm ---Seriously, what good reason is there for pacemakers to still use a reed-switch as an input device? With all the things you have to stay away from because they would either possibly trigger that reed-switch or otherwise disturb the device, how are they even passing regular EMI-tests?

--- End quote ---

Because those are life-supporting devices and need to feature ultra-robust ways of activating them as required, sometimes in emergency situations. So that must be done using simple means, certainly not any fancy remote. A magnet is obviously something that can easily be found even if you don't have the tools from the manufacturer. There's of course the drawback that comes with it, but with proper care, since it's a very "short-range" effect, the overall benefit/risk balance is still in favor of those simple approaches. If it required any complex remote, you'd be screwed in case you didn't have access to any, or it was not working, or whatever.

Some devices use Hall sensors instead of Reed ones. For the same function.


--- Quote from: m98 on August 30, 2021, 10:23:46 pm ---how are they even passing regular EMI-tests?
--- End quote ---

EMI testing doesn't involve any static magnetic field AFAIK.
Conversely,  the sensors used for this task shouldn't be sensitive to the kind of testing routinely done for EMC.

m98:

--- Quote from: SiliconWizard on August 31, 2021, 02:19:40 am ---Because those are life-supporting devices and need to feature ultra-robust ways of activating them as required, sometimes in emergency situations. So that must be done using simple means, certainly not any fancy remote. A magnet is obviously something that can easily be found even if you don't have the tools from the manufacturer.
There's of course the drawback that comes with it, but with proper care, since it's a very "short-range" effect, the overall benefit/risk balance is still in favor of those simple approaches. If it required any complex remote, you'd be screwed in case you didn't have access to any, or it was not working, or whatever.

--- End quote ---
There ought to be some better way. This is just lazy engineering.
Magnets are easily at hand because strong permanent magnets (and strong low-frequency EM-fields) are everywhere. There is no reason for everyone to be able to change the mode of a pacemaker just willy-nilly. In ambulances and hospitals you already only have ring magnets from the manufacturers(which are also approved medical devices, nobody just carries some fridge magnets in the hope they might also work), those could easily be replaced by a standardized remote, that in its simplest form could function identically to the magnet by just having to place it on the device.

SiliconWizard:

--- Quote from: m98 on August 31, 2021, 12:27:36 pm ---
--- Quote from: SiliconWizard on August 31, 2021, 02:19:40 am ---Because those are life-supporting devices and need to feature ultra-robust ways of activating them as required, sometimes in emergency situations. So that must be done using simple means, certainly not any fancy remote. A magnet is obviously something that can easily be found even if you don't have the tools from the manufacturer.
There's of course the drawback that comes with it, but with proper care, since it's a very "short-range" effect, the overall benefit/risk balance is still in favor of those simple approaches. If it required any complex remote, you'd be screwed in case you didn't have access to any, or it was not working, or whatever.

--- End quote ---
There ought to be some better way. This is just lazy engineering.

--- End quote ---

Simple solutions that work and are robust is good engineering.
Do not hesitate to suggest a better alternative. And then let it pass all analysis, use cases, reliability, regulatory compliance. We'll see how far you get. Probably thousands of engineers have already tried.

Deactivating the devices, in particular for defibrillators (likely a lot more than for pacemakers), must be easy enough and you may have to do it in emergency situations.

I have heard a lot of things, but that implantable devices are designed with lazy engineering, this is a first. So yeah, a bit of humility could help here. "There may be a better way, if we work hard enough on it, after considering ALL constraints and use cases." is probably more realistic than your statement above.

dferyance:
As someone who mostly wears mechanical watches, I've been noticing how frequently magnets have shown up in everyday items. Magnets are very bad for mechanical watches. Normally, I'd expect to see them in motors, speakers and normal electro-mechanical devices but it is so easy to run across a random neodymium magnet used as a door latch or to hold a keyboard on a tablet or for charging cables.

A magnetized watch isn't exactly the travesty of a pacemaker malfunctioning but I'd sure wish we didn't put magnets everywhere and used mechanical clasps instead.

I remember those Microsoft Surface ads with the keyboard that clicks on and off. Hell no, keep those away!

m98:

--- Quote from: SiliconWizard on August 31, 2021, 06:27:31 pm ---Simple solutions that work and are robust is good engineering.
Do not hesitate to suggest a better alternative. And then let it pass all analysis, use cases, reliability, regulatory compliance. We'll see how far you get. Probably thousands of engineers have already tried.

--- End quote ---
If the simple solution has the drawback of a critical device being way more vulnerable to external influence from common household items and appliances, then it certainly isn't a robust solution. I'd also doubt thousands of engineers have worked on this particular mechanism on pacemakers. It certainly is a legacy feature from a time where there really might've been no more reliable remote input mechanism than a reed switch so nobody ever dared changing that.


--- Quote from: SiliconWizard on August 31, 2021, 06:27:31 pm ---Deactivating the devices, in particular for defibrillators (likely a lot more than for pacemakers), must be easy enough and you may have to do it in emergency situations.

--- End quote ---
Accidentally (and temporarily) disabling an ICD is also not nearly as critical as suddenly changing a pacemaker to asynchronous mode. One of both can make you require a defibrillator real quick if you're unlucky. I don't see how random people/first responders would benefit from triggering magnet mode on a patient with such an implanted device.
"Oh, he's screaming in pain, I haven't even recorded an ECG, I don't even know how to read an ECG (is that the thing with the wiggly lines?), but it must be his ICD malfunctioning! Quick, take off your magnetic belt buckle and let me fiddle it over his chest in the hope of being somewhere near the implant's location!" - Someone, somewhere, maybe.


--- Quote from: SiliconWizard on August 31, 2021, 06:27:31 pm ---I have heard a lot of things, but that implantable devices are designed with lazy engineering, this is a first. So yeah, a bit of humility could help here. "There may be a better way, if we work hard enough on it, after considering ALL constraints and use cases." is probably more realistic than your statement above.

--- End quote ---
I was speaking in relative terms. Not using that better way that requires a lot of thought and hard work is "lazy". It's not like a corporation like Medtronic is on a tight budget, so there's no need to get overly protective.

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