Thanks again for sharing your splitter design. We tried one of these and learned from it to then build a new design from scratch that is a bit more condensed/thicker/faster to print.
Check out the LRTee: Last Resort 22mm Ventilator Tubing Splitter (https://www.prusaprinters.org/prints/28378-lrtee-last-resort-22mm-ventilator-tubing-splitter) for more info/files. (edited)
Have tested the 2way splitter on a Hamilton T1.
Because of the coaxial tube supplied with the ventilator, it is essential but possible to line up the splitters and attach two circuits.
However currently wouldn’t be viable to use the flow restrictors at the ventilator, unless paired (just due to the increased standoff but fixed relationship of the coaxial tube).
Useful idea though, I will keep play testing.
I would second the suggestion about fragility, and would be interested in the designs suggested with slightly thicker walls, very difficult to separate flow restrictors from splitter due to fragility and the ringing.
Good work Alex (edited)
We've tested a pair of these dual splitters (printed in PLA), and they looked great visually, but they were not able to pass the "leak test" that most modern ventilators perform to ensure a properly closed system.
The thicker remix DID pass the leak test before sterilization, but shrunk slightly when sterilized. (see: https://www.prusaprinters.org/prints/27803-ventilator-circuit-splitters-reinforced-thicker-wa). As such, we're planning to print at 104% scale, sterilize, and see if that will do the trick.
Thanks for sharing and spurring on further development. Hope it doesn't come to needing printed ventilator splitters, but it appears we're already there in many places.
Somehow I missed this comment. Interesting: all my tests prints passed on 4 different ventilators.
For us, it seems like it came down to two leak sources: through the part itself (which could likely be improved by over-extruding, like a 1.2x extrusion multiplier), and around the female connection (since that side goes onto the harder plastic fitting on the machine, as opposed to the softer tubing on the male ends).
Your design was an awesome start for us to get something printed and on a ventilator before we had worked through the whole process. Thank you again!
The LRTee design we are currently printing has gone through many rounds of minor adjustments to make it a bit more robust, faster to print, and verified to still work post-sterilization. It's still a work in progress and we plan to keep it updated as suggestions/improvements come in.
Any chance you can post a STEP or Fusion 360 source file? I may need to make modifications for one facility that may need them.
I'm not sure yet. I did supply a local hospital with dual split design, and I saw there was a 4 so (having some spare time) - I've created a Fusion 360 file of the design that I'm tweaking - so far I've made it a 3 hose splitter.
It fits well with your design so it should be good. https://a360.co/2wMTMhr
Not sure if this would be of any help to anyone - but here is my base file for making the splitter with tools for making different flow restriction sizes if need be https://a360.co/3bzF5wW
is this safe in PLA for human use? we've bound to test them in Spain
Nothing should be used without a splitter. I can't make any comment about the safety of any material that you may use sorry.
Will test this out on some patients in Madrid, Spain tomorrow.
How did it go?
It works.
I’ve had a friend print it, and I tested it yesterday at the hospital, not in real patients, but it works just fine.
I’ll not use the flow reducers. I intend on using an hydraulic valve to manually adjust flow to both inspiratory outlets.
However: this is too thin and fragile. We are currently trying to edit your project to have thicker walls, such as this black plastic piece, it would be much stronger this way. Notice that I envolved the originally blue piece into bandages to enhance its strength. If the chaos develops soon, we will really save lives with this little piece. As for now, I intend to have about 5-10 kits ready to deploy at my unit, and print more if needed be.
cool - yeah, I used the original as a design guide and made thicker reinforced versions (in the remix section) I've test printed the duce split and it's really tough.
https://www.linkedin.com/posts/activity-6650461482456752128-fgfT ( we have reinforced for 2, 3, and 4 vias )
A friend, an ER nurse, asked me to find a way to make a ventilator work for 2-4 people. I found your design and printed it. It will be going to a hospital in Alabama and South Carolina for testing. Thank you for the design!
I don't get how this would work
Surely there would be a massive drop in pressure for a start. Secondly each person needs personalised oxygen preferences in these machines which wouldn't be catered for with this and finally surely there would be hygene issues. Please correct me if I am misunderstanding this whole device.
Alexander , we tested the build and the body is a little fragil in FDM , I redesigned your model with thicker wall , contact me so i send you the step.
What a fantastic design. I'm going to print some to test. Have you tried it out?
Yes - but only here in my 'lab' - no real use conditions.
It seems like a few of us are looking at the same thing. I've made both 2-way and 4-way splitters that print quickly and without support material. I've also designed a flow restrictor, which uses a flexible 22mm tube and a screw to adjust flow. I'll upload the files here too.
You guys are all awesome. I'm test printing on my resin printer until I get parts for my defective Prusa.
FWIW - I've made a inline adjustable flow fitting that will allow a lot of adjustment - to the point of fully cutting off the flow. https://www.prusaprinters.org/prints/27851-flow-restriction-device-for-multiple-patient-lung- (edited)
