[HN Gopher] Philips recalls 340 MRI machines because they may ex...
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Philips recalls 340 MRI machines because they may explode in an
emergency
Author : LinuxBender
Score : 66 points
Date : 2023-12-24 19:24 UTC (3 hours ago)
(HTM) web link (www.theregister.com)
(TXT) w3m dump (www.theregister.com)
| BobaFloutist wrote:
| Well that's definitely not what they're supposed to do.
| jt2190 wrote:
| The Food and Drug Administration's web page about the recall is
| clearly written:
|
| (edit: actually not a recall but a requirement that the machines
| are not used until they're serviced)
|
| https://www.fda.gov/medical-devices/medical-device-recalls/p...
| akira2501 wrote:
| That's absolutely a recall. An FDA recall means the product is
| in violation of the law. Those violations must be corrected or
| the device must be destroyed, and if not, then the FDA has the
| right to seize it.
|
| The recall strategy in this case is not to ship it back to the
| manufacturer, but to have the manufacturer come out and service
| the device until it is again compliant with the law.
| s1artibartfast wrote:
| It has very little to do with the violations of the law.
| There is no law that states mri machines must have <X% chance
| of exploding.
|
| The way these things work is that the firm has decided based
| on their data and reports to issue a recall and notify the
| FDA. The manufacturer recommends hospitals not use the
| device, however there is the possibility that they continue
| to do so (the probably won't for liability reasons).
| pkaye wrote:
| Take the number of MRI machine in the field, A, multiply by
| the probable rate of failure, B, multiply by the average
| out-of-court settlement, C. A times B times C equals X. If
| X is less than the cost of a recall, they don't do one.
| Jabbles wrote:
| _There has been one reported event of an explosion in 22 years
| of use. There have been no reports of injury or death._
|
| I wonder what the total negative health consequences of not
| being able to use all those MRI machines until they are
| serviced will be.
| fnordpiglet wrote:
| Also doesn't say it happened to a Phillips machine, my read
| is that's for any MRI machine - ever.
|
| So, yeah, a recall, but nothing ominous about it. Things get
| recalled all the time.
| sverhagen wrote:
| Yet the press this is getting is, like the article said, a
| black mark on Philips. They were a very diverse company,
| until they chose a few specific markets in which not to
| divest, healthcare being one of them. This must be quite
| the chill at headquarters.
| pstuart wrote:
| It's a pity that the helium is vented out, considering its
| increasing rarity.
|
| I'm guessing that capture and reuse probably would add way too
| much to the price of the machine.
| Metacelsus wrote:
| It can be recovered, see for example:
| https://news.ucsc.edu/2019/12/helium-recovery.html
| fabian2k wrote:
| This is about quenching, which happens in emergencies or
| failure. During regular use helium is recycled in similar
| systems often today. But it's simply not feasible to do that
| when all the liquid helium in there evaporates at once
| cperciva wrote:
| If you suddenly have thousands of L of He gas on your hands,
| venting is better than exploding.
| namibj wrote:
| The issue in that respect is that they flood the coils in a
| helium bath, instead of utilizing additional structures like
| channels/nozzles to provide the same rate of freshly cooled
| helium to the heat sources as the bath does, but with far less
| helium required in the system.
| fabian2k wrote:
| I don't think any similar magnet exists that doesn't embed
| the magnet in a dewar full of liquid helium. And it probably
| doesn't make any sense to do it differently, even if it were
| possible.
|
| You need some mass here for the helium anyway as you never
| ever must run dry and it constantly evaporates.
| ars wrote:
| This only happens in an emergency, not during normal operation.
|
| Pretty much the only time you would do it when a person is
| stuck in the machine by some piece of metal that is attracted
| to the magnet. You hit the quench button which vents all the
| helium, but more importantly also halts the magnet (all the
| energy released from halting the magnet goes into boiling the
| helium), and then you can release the person.
|
| You don't do this for any other purpose, for example if some
| metal cart is stuck in the machine, but no one is at risk, you
| use a slower method to shut down the magnet (i.e. drain the
| energy) that doesn't vent the Helium.
| londons_explore wrote:
| I was under the impression that metal 'sticks' to an MRI
| machine with so much force it will usually puncture the
| machine and all the helium will leak out ..
| fabian2k wrote:
| Large metal objects can cause a quench. Smaller and medium-
| sized ones usually won't, they will just stick to the
| magnet until you release them.
| akira2501 wrote:
| Liquid helium has a 745:1 expansion ratio when converting into a
| gas. So, that's not a fun problem to have.
| lnxg33k1 wrote:
| Its unbelievable the decline of philips, i used to buy their
| stuff out of trust, but given their story with ventilators, this
| one, and other personal ones with razors, waterfloss and
| toothbrushes, I wouldn't touch anything from them with a ten foot
| pole
| terom wrote:
| > There has been one reported event of an explosion in 22 years
| of use. There have been no reports of injury or death.
| lnxg33k1 wrote:
| So they don't explode when they're new, but after a while?
| How old was the machine exploding?
|
| Not sure how your message disproves mine, this would be the
| second recall in few years for philips, whatever, doesn't
| come through as high quality
| krisoft wrote:
| > So they don't explode when they're new, but after a
| while? How old was the machine exploding?
|
| No. What they say that the problem occurs only very rarely.
| The first of this MRI model was introduced in 2001, there
| are hundreds of them used all the time and only one
| explosion happened. Presumably that is the explosion which
| has shown them that there is something wrong with the
| model, and now they are taking corrective action.
|
| > this would be the second recall in few years for philips
|
| It is a huge company doing a lot of things. The safest way
| to never make a mistake is by sitting on your hand and
| refusing to do anything.
|
| Some of the affected MRIs are old enough now to buy you a
| alcohol, how is this an evidence of anything recent with
| Philips?
|
| > whatever, doesn't come through as high quality
|
| They found a rare but potentially high impact issue and are
| fixing it in decades old equipment on their own dime.
|
| Show us that you have done things of similar complexity
| better. What equipment you have designed is in constant
| operation since 22 years? How do you know it doesn't have
| any low probability, high consequence failure modes?
| CharlesW wrote:
| The parent commenter isn't just talking about this recall,
| but what appears to be a developing pattern:
| https://www.nytimes.com/2023/09/07/health/cpap-defect-
| recall... (https://archive.is/gvqmN)
|
| > _The lawsuits have claimed that flaking foam and gasses
| emitted from the machines were linked to health issues
| including respiratory illnesses, lung cancer and death. The
| foam was used in the machines to reduce noise and vibration._
|
| > _In June 2021, the Food and Drug Administration announced a
| recall of Philips machines that also included BiPAP devices
| and ventilators made since 2009, warning that foam
| deterioration in the products could cause "serious injury" to
| users. Philips initially released a memo to doctors saying
| the foam breakdown posed risks of "toxic carcinogenic
| effects," but the company has since released updates
| reporting a far lower level of concern._
| hinkley wrote:
| "I don't wanna explode."
| trebligdivad wrote:
| I dont understand what the fault is - quenching is bad but
| happens. Blocking the quench path sounds bad - is it saying that
| something is causing it to be blocked or is the machine supposed
| to do something else if hte quench path is blocked (what can it
| do??)
| EA-3167 wrote:
| The rapid conversion from liquid or solid to gas, and the means
| to (briefly) contain that... is a _bomb_. The reason you don 't
| block the emergency relief is that you turn a quench from an
| emergency involving asphyxiation, to something resembling a
| detonation.
| trebligdivad wrote:
| Right, but that's true of all MRI's - so what's different in
| this one?
| refulgentis wrote:
| "During a quench, which is not common, a large amount of
| helium evaporates and is vented outside the building
| through a venting system," the recall explains. "If an
| unknown blockage is present in the venting system and the
| pressure exceeds design limits, the structural integrity of
| the system could be compromised."
| op00to wrote:
| This is a risk of any mri machine that uses helium to
| cool a magnet. Why are only these machines being recalled
| when if you block the exhaust of any mri scanner it will
| blow up?
| jabiko wrote:
| This is just speculation, but maybe there is a secondary
| rupture disk that vents the helium inside the room when
| the primary path (the exhaust to the outside) is blocked.
| And maybe that secondary rupture disk is too strong, so
| another random part of the helium containment fails,
| blowing up the machine and possibly injuring the patient.
| But please note again that this is pure speculation.
| s1artibartfast wrote:
| That doesn't explain what is different. I assume that is
| a feature common to all machines.
| Piezoid wrote:
| Why not add a pressure relief valve on the quench path
| with a very loud whistle? That should be enough to take
| care of such rare and compounded failures.
|
| What does recall means in this context? De-energizing the
| superconductor and shipping it back? Seems like a waste
| and a planning nightmare.
| userbinator wrote:
| I suspect this recall is precisely because someone
| figured that the relief path wouldn't work.
| crest wrote:
| The Helium used for cooling expands a lot going from liquid to
| gas during a quench (iirc by a factor of ~1800). The pressure
| built-up from the phase change has to be relieved *quickly*
| before the machine turns into a crude pipe bomb. Oh and you
| can't get enough Oxygen from the air if most of it has been
| replaced with leaked Helium.
| jokoon wrote:
| I worked in x ray imaging software in a company that assembled
| them.
|
| Risk assessment and traceability are not fun, but it's
| interesting to see how to make safe things.
|
| I wish general software had similar constraints or designs, or at
| least insurance companies would lobby the government to force
| software companies to proof read their code.
|
| I don't want rust everywhere, but it should still be possible too
| approach what rust is doing by other means.
| serial_dev wrote:
| Toxic teams and lazy developers will also find way to produce
| crappy software with Rust.
|
| The Rust developers of today might produce better software,
| because they are the early adopters who care about performance,
| safety and correctness, but I believe (assuming Rust becomes
| mainstream) if you give regular developers Rust to code in,
| they will produce the same quality as they do with Java,
| Javascript, or C.
|
| The environment and the individuals are significantly more
| important than the programming language they use.
| refulgentis wrote:
| Where would i go to learn the fine details of how things like
| risk assessment and traceability work in practice?
| cperciva wrote:
| Note: MRIs are incredibly safe. Your risk of dying due to an MRI
| machine exploding is significantly less than your risk of dying
| due to falling while climbing into the machine.
| fabian2k wrote:
| You should respect the magnet though. Those warnings aren't
| there without reason, getting between an MRI or NMR and a
| magnetic piece of metal is a bad idea
| cperciva wrote:
| Oh, absolutely. MRI machines are incredibly dangerous if not
| handled properly. But the overwhelming majority of MRI-
| related dangers are well understood and avoidable.
| pengaru wrote:
| Case in point: https://www.miamiherald.com/news/nation-
| world/national/artic...
| figmert wrote:
| ~~I don't know why this is relevant, and quite frankly I find
| comment odd. Just because y is safer than z, does not mean we
| should ignore reasons why z isn't safe.~~
|
| See OP's response for why this is crossed out (assuming HN
| supports it).
| cperciva wrote:
| I think it's an important point to reinforce because news
| stories like this can make patients afraid of MRIs,
| potentially resulting in them avoiding necessary imaging.
| Most people on HN are probably not going to make that error
| -- but I think we have a responsibility to help communicate
| to the broader community in this regard.
| serial_dev wrote:
| Each man is the architect of his own destiny.
|
| If someone is afraid of MRI machines exploding (I've never
| met anyone like that), they will need to live with the
| consequences of that decision.
| s1artibartfast wrote:
| Of course. But that doesn't mean it isn't worthwhile to
| be clear on what the factual risks are.
| figmert wrote:
| Great point, and it makes sense. Thanks for clarifying.
| dukeofdoom wrote:
| At what point are less safe but cheaper machines worth it.
| Hospitals ration MRI machine access through out the world. Even
| in Canada, you have to wait on a list to get access.
|
| "Canada could expect to wait a median of 5.4 weeks for a CT scan
| and 10.6 weeks for an MRI scan"
| lnsru wrote:
| Is it not the case, that wait time goes to zero if you pay in
| cash immediately?
| mattlondon wrote:
| FWIW in the UK I was able to get a MRI the next day when
| going private. They even gave me a CD with the images.
|
| They would have even done it the same day but _I_ wasn 't
| available.
|
| I suspect in the NHS I wouldn't have even got a MRI at all
| (it was for a mildish running injury to my knee and just
| needed some physio in the end, so MRI seemed like overkill!)
| LegitShady wrote:
| thats because Canada has less than 20% the MRI machines
| proportionally to population as Japan, and 25% of the MRI
| machines as the US. We're down near the Czech Republic and
| Turkey.
|
| From 2019:
|
| https://www.statista.com/statistics/282401/density-of-magnet...
|
| I didn't look very long so maybe there's more recent numbers
| available.
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