• palal@lemmy.ml
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    1 year ago

    Don’t those cryogens only boil off in significant quantities of the machine can’t get power?

    Like, isn’t that the whole reason MRI machines are never turned off?

    • becausechemistry@lemm.ee
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      1 year ago

      The cryogens boil off at a pretty consistent rate no matter what, but the recovery/recompression systems do require power. So once power is cut, any boil off isn’t recovered.

      Superconducting magnets (like in MRIs) can run effectively forever when at the right temperature. Turning them off requires a complex process of draining off that current slowly and carefully so that the magnet isn’t damaged. Hard to do on a normal day, and profoundly harder if there’s no power.

      • palal@lemmy.ml
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        1 year ago

        Ahh, makes sense. That’s so cool! Do you know what kind of priority a hospital would have if they were to ration electricity? Would an MRI machine be high on that list?

        • Apollo@sh.itjust.works
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          1 year ago

          Probably first on the “turn this off” list, its ultimately a diagnostic tool and when it comes to rationing power life support equipment has first priority. Its an insanely power hungry device and shutting it off could let you run dozens of ventilators etc.

          • palal@lemmy.ml
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            1 year ago

            So, does that make it primarily useful for if the hospital is looking to do surgery?

            IIRC al-Shifa was still doing complicated surgeries really late into the conflict.

            • Apollo@sh.itjust.works
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              1 year ago

              Not necessarily, an MRI is great to have but not necessary to carry out surgery, while something like ventilation absolutely is.

              Power usage of an MRI machine is pretty mega, it’d be hugely wasteful to prioritise running it vs even just keeping fuel in reserve.

        • becausechemistry@lemm.ee
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          1 year ago

          No idea, but if it were up to me I’d spend that rationed power on ventilators and such keeping patients alive. Losing cryogens stinks, but you can top them off without any power as long as you have stock or deliveries. And I’d rather a magnet quench than have to explain to a dead person’s family that their loved one’s life was less valuable than some helium and a chunk of ceramic.

          • palal@lemmy.ml
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            1 year ago

            Weren’t they still doing surgeries at al-Shifa up until the power went out? I’d imagine that an MRI might be useful for diagnosing issues prior to surgery…

            • becausechemistry@lemm.ee
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              1 year ago

              Beats me. I’m just a chemist who managed my facility’s NMR magnets (built like MRIs but with different electronics for chemical analysis) for a few years. We had to pull some stunts to keep those magnets alive sometimes, but it was always a matter of how soon, not if, a shipment of cryogens would arrive. Can’t imagine trying to keep MRIs from quenching in a war zone.