Is next: 3d printed guillotine designs.A hospital in Italy was in need of the valves after running out while treating patients for COVID-19. The hospital's usual supplier said they could not make the valves in time to treat the patient. That launched a search for a way to 3D print a replica part, and Cristian Fracassi and Alessandro Ramaioli, who work at Italian startup Isinnova, offered their company's printer for the job.
However, when the pair asked the manufacturer of the valves for blueprints they could use to print replicas, the company declined and threatened to sue for patent infringement. Fracassi and Ramaioli moved ahead anyway by measuring the valves and 3D printing three different versions of them. [...]
So far, the valves they made have worked on 10 patients as of March 14th, according to Massimo Temporelli, the founder of Italian manufacturing solutions company FabLab who helped recruit Fracassi and Ramaioli to print the replica valves.
"[The patients] were people in danger of life, and we acted. Period," said Fracassi in a Facebook post. He also said that "we have no intention of profit on this situation, we are not going to use the designs or product beyond the strict need for us forced to act, we are not going to spread the drawing."
On the other hand, before you start patting yourself on the back with your Arduinos and Shapeways orders, this thread from turzaak:
So. Biocompatability. Basically it means you want materials that a) don't fall apart, and b) don't poison/kill when you use them in something that's gonna interact with the gooey meat stuff. Also means you need to be able to sterilize. For med sterilization, soap-and-water is 1st step, but not enough. 3 common methods are:
1. chemical (isopropyl alcohol, acetone, other solvents)
2. UV
3. heat (autoclave, etc)Most plastics interact badly with at least 1 of those 3. ABS, one of the most common plastics and common 3D print material, dissolves in acetone. It melts at approx 105C and breaks down above 400C. When it breaks down, the materials are carcinogenic. Autoclave temp? >121C.
ABS also is not UV resistant. Your plastic that yellows in the sun? Probs ABS. So ABS is 0 for 3 here.
What about PLA? Degrades in UV, gets eaten by some bacteria and proteins, gets gooey at 60C, and can degrade with water. Also bad. [...]
Say you want to put some fancy electronics in here. What do you reach for? If you said "my spool of wire", congrats, you possibly will kill someone, unless that spool is gold wire. Copper is toxic. You had better be REALLY SURE about encapsulation or not use it at all. [...]
Okay, so we've got that and some enclosures figured out. Now what? Well, we building a ventilator? Let's talk pneumatics. What are your tubes made of? PVC? The C stands for "chloride". Guess what it produces when it's heated to degrade! Yeah, chlorine gas. That's why you don't stick it in laser cutters, unless you want to die.
Okay, forget plastics. What if we're using metals? Welcome to the world of steam and salt water. They hate you and all your materials. Rust, salt water eating away your metal, other chem reactions, they're all here! They suck. A lot. There's a reason implants are titanium and it's not because doctors want to put expensive things in you. It's one of the few materials that works.
You have to do this sort of analysis for EVERY MATERIAL YOU USE.
Previously, previously, previously, previously, previously, previously, previously, previously.
Makes me wonder why the company pulled the patent card and not the "don't do that, you could kill someone" card.
I've got some titanium in me, never really thought about why that material and not some sweet tungsten or aluminum. Glad someone's thinking about that!
These appear to be disposable gas valves, so the comments on Twitter would not be relevant for the Italians?
I would think you'd still have to sterilize each unit at least once, after fabrication. That might make it easier though (ie.g. f it takes repeated UV exposures to really break down the material, then maybe just one UV exposure would be acceptable).
'Well, behind door number one, we have 'not breathing.' Any takers?'
'Good choice.'
'Door number two is breathing, but it may not be up to sterilization standards? Any takers?'
And at some point a doctor is going to have to make the call, "Well I can follow the rules and write down 'pneumonia' as the cause of death, or I can break the rules and maybe write down 'chlorine gas poisoning' and try to explain that during my malpractice suit."
In summary, everything is terrible.
sterilize 3d printer and materials prior to fabrication?
And then you wind out breaking your £300 printer, rather than your ≪ £1 ventilator part
if breaking a £300 printer is your primary concern then a self-quarantine is by far your option.
Fair, but either way you don't end up with any usable ventilators
Costs nothing (significant) to try though. I understand some people can't, but most people bought a £300 3d printer because they have that budget to spend/enjoy/waste on non-essentials. Sterilise it. If it breaks, you tried to save someone's life, but need a new plan (and maybe a new printer, but maybe 'need' is not entirely accurate). But if it doesn't, you're on to a winner. Plus it's a hobbyist 3D printer, you probably didn't break it all. Find the bits that broke, find a different way to sterilise those, and you're back in the live-saving business.
NY Times picked up the story, kind of.
https://www.nytimes.com/2020/03/22/opinion/ventilators-coronavirus-italy.html
I'd like to think that the 3D printing process itself is hot enough for the extruded plastics to be rather dead by the time they cool off.
There's no winning in situations like this (other than going back in time and planning/lawing better). I used to work in pharma industry and anything related to human safety had to be regulated and validated (basically, tons of paperwork).
Sadly, some number of people have died after a firmware was updated on a server, which changed a subtle detail of how floating point was calculated, which ended up changing a dosing decision, which led to fatal doses. So now there is an extensive checklist and set of integration tests to ensure that you prevent a firmware update if it would cause tests to fail.
If your goal is to reduce risk to zero, the cost to do so goes to infinity. Also, a fair amount of planning and preparation for emergencies, at the cost of short-term profits, is a tough call few people in the modern economy want to take.
Not to mention accidentally creating environments promoting harmful bacteria growth. I recall an interesting lecture by somebody who created a high-end flight simulator in the 1980s. It required exotic liquid cooled CRTs. Bacteria started growing in the liquid, which created a by-product dissolving the seals on the plumbing, which started leaking and shorting things out.
Common CRT projectors all used liquid cooling. It wasn't anything exotic, though: Just a glycol mix. (I forget if it was propylene glycol as used in HVAC and cigar humidors or ethylene glycol as used in cars.)
They all required periodic fluid changes, too, in order to maintain good performance. (That big, dark, blurry projector that was still showing ball games at the local pub at the turn of the century? Or powering the ancient Duck Hunt game at the arcade? It needed a fluid change.)
Because shit grows in that warm and well-lit (but not UV) environment and living shit (unlike glycol) isn't optically transparent.
I'm amused that this attacked the rest of the system, though, which I guess is your main point: There are unintended consequences.
There was a pretty big correction issued on that article; the company didn't release the files, but didn't threaten legal action.
I mean, we all would have easily believed it if they had, but the role of corporate vampire will be played by somebody else today.
It is incredibly likely that the original valves were made of ABS. They must have sterilized those somehow, despite it allegedly being so difficult to sterilize plastic.
Oh, and also no one uses acetone or autoclaves to sterilize ABS. Often, they use alcohol, which even the much more fragile PLA doesn't care about.
Yes, if I try to put any plastic in a high-temperature situation, or if I expose them to solvents that themselves are carcinogenic, or I put these valves inside humans (which doesn't look like their intended use to me), there could be consequences.
The thread from turzaak seems to be a tirade about how my $300 3D printer isn't going to actually let me print a new copy of everything inside my house and solve world hunger.
According to the article in Business Insider, they didn't just use a $300 printer. They also printed on SLS and SLA printers, which can be quite expensive. And the valve didn't go inside a respirator; it was for a CPAP hood, similar to this:
So no heat, no noxious chemicals, just oxygen on the intake side and contaminated exhaled air on the exhaust side.