Philips recalls 340 MRI machines because they may explode in an emergency
theregister.com
theregister.com
(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...
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.
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).
I wonder what the total negative health consequences of not being able to use all those MRI machines until they are serviced will be.
So, yeah, a recall, but nothing ominous about it. Things get recalled all the time.
Just because nobody was in the danger zone the first time it exploded doesn't mean you should count on nobody being in the danger zone the second or third time it might explode. This is the reason work site safety officers yell at people to report all near-miss incidents, not only the accidents that get people hurt. If something went wrong and nobody got hurt by chance coincidence, it might happen again when people are actually near it. Therefore a near miss incident needs to be addressed with the same seriousness as an accident that actually caused injury.
Every MRI machine quenches and vents. The question is what is different, in detail, that heightens the risk with this machine.
your response is like saying "the engine wont work" as a complete explanation for why a type of car has more automotive problems than another. Then, when a mechanic is curious about the nature of the failure, you call them stupid, saying "I already told you, i said it doesnt work!"
I certainly hope you are not in charge of solving problems in any professional capacity.
The design can't safely accommodate the level of energy that ends up in the machine if its clogged.
In the spirit of analogies, it's like asking why a 10 oz glass overflows with 200 degree water and a 10 oz glass doesn't overflow with 100 degree water. It exceeded it's capacity.
There's nothing more complicated to it, you could call in an MRI technician, get the PDF manual, talk to several doctors, disassemble it and put it back together, and learn no more than that.
You got extraordinarily rude and personal, I hope you don't do that often on HN, that was an outlier in my 13 years here. I hope all is well and it's an exception.
What does recall means in this context? De-energizing the superconductor and shipping it back? Seems like a waste and a planning nightmare.
A surprising amount of maintenance can occur while the magnets are cold and energized. My armchair-uniformed-guess is that they can replace the not-always-working relief path without venting.
Remember, cryostats are like Russian dolls suspended on torsion wire. You want the mass of the metal inside to be as low as possible because it forms cold bridges to the outside world and increases the boil-off rate. Quenches should not happen once the magnet leaves the factory, but until that point it's not uncommon for a machine to have several "training" quenches as the (typically NbSn or NbTi) superconducting wire effectively anneals in place. A fixable giant hole in the top (with a graphite, insulating series of bursting discs) is the approach usually taken.
A blocked quench pipe and a stainless steel (typically A4 stainless) cryostat becomes a bomb: cryogens expand in volume by about a factor of ~700 when boiling and so the volume they occupy at 1 bar and 300 K is, well, far far larger than the volume of the room the scanner is in.
This is the sort of thing that is a (remote) risk to life. I've only ever seen one (preclinical, not-for-human-use) magnet unexpectedly quench; copying and pasting a paragraph from my PhD thesis:
*The overpressure created by the rapid boiling of the large volume of liquid helium surrounding the superconducting magnet was sufficient to burst the bursting disc (as designed), which allowed the venting of helium gas from the inner cryostat to the emergency quench pipe (the bursting disc was temporarily replaced by clingfilm in this photograph). Additionally, it was also sufficient to rip and blow off the quench pipe, break two windows, damage the floor, and relocate several light items within the magnet room (which, presumably, was not as designed)*See OP's response for why this is crossed out (assuming HN supports it).
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.
CERN retrospective on the event: https://home.cern/news/news/accelerators/lhc-leak-repair-sho...
"Canada could expect to wait a median of 5.4 weeks for a CT scan and 10.6 weeks for an MRI scan"
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!)
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.
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.
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.
I'm guessing that capture and reuse probably would add way too much to the price of the machine.
You need some mass here for the helium anyway as you never ever must run dry and it constantly evaporates.
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.
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
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?
I think it is very illuminating. Imagine you created a thing. It is successful enough that hundreds of hospitals bought it. They use it day after day for healing people. And after 22 long years ago one of the many many decisions encapsulated in that product is a mistake in hindsight. You worry it might cause harm in rare cases. But, luckily you can send around a service technician who checks things, maybe takes corrective action and it further lowers the already low chance of anyone getting hurt.
Would you feel like a failure? I would be over the moon that I made something so successful and helped heal so many people. Would be slightly embarrassed that I have missed something, but glad that nobody got hurt and we can fix the issue.
If this is how I personally would feel why should we act as if the company as a whole is a complete failure?
> Maybe if they do too many things that need to be recalled they should cut somewhere
You don't understand me. It is not that they do too many things and that is why they have recalls. Every human endeavour has the chance of things going slightly wrong. If an entity, a company in this case, has many projects it is more likely that you will hear about some of them being occasionally going a little bit wrong.
What I'm saying is that you should look at the number of recalls as a proportion of their reach and volume. And if you do that you will realise that they are neither exceptional nor should they feel ashamed of themselves.
It sounds like you demand perfection and that is not a realistic goal to attain.
> 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.