Originally Posted by percussionking
I'm in school for engineering but I'm not convinced it's an engineering issue. If they could make it last a long time, people wouldn't have to buy the product as often. It may be more about business than technology.
But I must add...
MRI scanning machines typically have to be in a room that has copper behind all the walls (see
this page for details) and you don't see them tearing down the walls every week to get to the copper plates.
I think that site is a little misleading. Yes if the MRI machine is constantly on, then the copper/steel plates would be partially charged, but if they turn them on and off, then any of the particulates that were stuck to the plates would then just settle to the ground (though I doubt that there would be a lot of contaminants in the walls to begin with). The whole point of the plates is to create a Faraday Cage, so that any electromagnetic energy doesn't go shooting off everywhere and mess up any nearby equipment. It wouldn't be good if the MRI sends all the equipments in the ICU into haywire. That's the whole reason why you're not supposed to use a cell phone in hospitals. The radio waves screw with the sensitive instruments in there.