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Magnet in Apple devices is not EMI. How do I know? I had to certify one device for EMI. Magnets cause no harm to pacemakers, though a large enough magnet could

Magnet in Apple devices is not EMI. How do I know? I had to certify one device for EMI. Magnets cause no harm to pacemakers, though a large enough magnet could disable it permanently (that would have to be a really strong, large magnet, though). Pacemakers are designed so that they are disabled by magnet. This is used in case the device malfunctions. Rather than cut up the person in a hurry, you can just use a magnet to stop the pacemaker from causing damage. Any person that wears pacemaker will know how it works and will not put any electronics in their shirt pocket. Here you can see pacemaker teardown on EEVblog, showing the reed switch that responds to magnet to cut power to the device: https://youtu.be/sNW3Xqtgkus?t=696 https://youtu.be/sNW3Xqtgkus?t=696 Magnets were chosen for this because they are universally available and if you wear a pacemaker that misbehaves it is easy to find magnet or ask somebody else to find a magnet and bring it to your chest.

corty 5y ago
A magnet does not always switch the pacemaker off. For pacemakers that are vital, the magnet usually switches to a safe mode, e.g. some fixed non-adaptive frequency and voltage. Frequency and voltage are chosen in a way that the patient will not suffer injury from it and have sufficient circulation to survive. However, due to the necessary higher frequency and pressure when standing up, walking, those things will lead to weakness, fainting, dizzyness and all the other symptoms of low blood pressure. Safe mode will keep you alive, but it definitely won't be fun.
- lmilcin 5y ago
  I have to use simplified language sometimes to get the point across. I could write all day how I work with electronics, have my own laboratory, what the EMI is and why exactly magnet is not one, but by the time I would get to the point most readers would already either fall asleep or would just look at the huge article and skip to another post. Yes, pacemakers became more complex devices but at least the older ones work as I described and for the newer ones it is enough approximation. It is not like you can do anything else or anything different if one misbehaves.

corty 5y ago

A magnet does not always switch the pacemaker off. For pacemakers that are vital, the magnet usually switches to a safe mode, e.g. some fixed non-adaptive frequency and voltage. Frequency and voltage are chosen in a way that the patient will not suffer injury from it and have sufficient circulation to survive. However, due to the necessary higher frequency and pressure when standing up, walking, those things will lead to weakness, fainting, dizzyness and all the other symptoms of low blood pressure. Safe mode will keep you alive, but it definitely won't be fun.

lmilcin 5y ago
I have to use simplified language sometimes to get the point across. I could write all day how I work with electronics, have my own laboratory, what the EMI is and why exactly magnet is not one, but by the time I would get to the point most readers would already either fall asleep or would just look at the huge article and skip to another post. Yes, pacemakers became more complex devices but at least the older ones work as I described and for the newer ones it is enough approximation. It is not like you can do anything else or anything different if one misbehaves.