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  • Ventilator manifold can quadruple number of people on ventilation

    Posted by TM Lutas on March 25th, 2020 (All posts by )

    A paper published in 2014 documents the invention of a ventilator manifold which can lead to up to 4 people sharing a ventilator.

    Ventilator manifold for disaster surge usage

    You can find the paper here and an article describing the invention here.

    Does anyone know the regulation that is stopping us from printing these manifolds and reducing the death toll from a local overwhelmed medical system? A lot of people are rightly worried about our ventilator situation. Something that quadruples system capacity would be a godsend.

    Update: This is deemed a method of desperation with numerous problems that can lead to worse patient outcomes in this joint statement by six US medical associations. They really don’t like it.

    This is not stopping innovators like Prisma Health from developing ways to have multi-user ventilators.

    Update 2: New York has approved ventilator splitting as they purchase 7,000 more ventilators. Federal ventilators are also starting to arrive, all 400 of them.

     

    16 Responses to “Ventilator manifold can quadruple number of people on ventilation”

    1. David Foster Says:

      Don’t ventilators have Settings, which have to be adjusted to the needs of the individual patient?

    2. MCS Says:

      I saw a piece on a Canadian doctor that had extended one vent to nine people. He said that the people had to be matched by lung volume.

      At one point I spent a lot of time with nothing better to do than look at a ventilator. You’re right, there are a lot of gauges, dials, and screens. I was able to make sense of most of them to a point. The first issue is not causing lung damage that can come from too much pressure or to fast flow. Then there is the need to use enough to inflate the lungs as completely possible both for oxygenation and to keep stagnant pockets from developing that would be a breading ground for infection. There seemed to be lots of different ways to modulate the flow both going in and out. I imagine that with the lungs damaged or already under attack from an infection it gets a lot more complicated. It’s a lot more complicated than a simple air pump.

      I obviously defer to people with actual knowledge like the Canadian doctor. I also imagine that matching lung capacity is a little more complicated than just physical size. I can also easily imagine that a slightly more evolved design would greatly improve the usefulness.

      I have no doubt that the shop I use for sheet metal work could turn out dozens of these while you were waiting for one to finish printing. Wouldn’t it have been nice if a few of the people haranguing us with warnings that we didn’t have enough ventilators could have spent a little time evaluating something like this ahead of time to see if it would help? Maybe having some built and available for use in an emergency. As I stated elsewhere, vents are complicated machines and probably can’t just be put in a warehouse for years only needing to be wheeled out and plugged in when needed. A long term storeable vent might be something worth having too.

    3. TM Lutas Says:

      David Foster – If you have enough ventilator patients that your system is overwhelmed, you have good odds that enough of them will match in requirements to make this useful. You won’t actually quadruple results but doubling would be nice.

      MCS – The study linked came out in 2014. The incentives for something like this to get FDA approved are pretty counterproductive. This is the sort of thing that makes up the majority of the crimes of the deep state. They know the incentives are wrong and that simple lifesaving stuff is not being approved but they just let it go because getting a $3 part approved risks their job if something goes wrong. They never get called on the dead that occur because of this in any real way.

      The speed of construction doesn’t matter much if you do the work in time and have years to turn out adequate numbers of manifolds but you might very well be right on the speed.

    4. BobtheRegisterredFool Says:

      What is the cleaning protocol to prevent patients sharing air from sharing secondary infections?

      3D printing the adapter means a) voids in the material that may make cleaning more difficult b) material choice that may or may not be compatible with whatever cleaners you want to use. Okay, there are more expensive options that permit different materials, or materials with fewer voids, but those processes are not the defaults you think about when you think about 3D printing.

      If patients A and B are sharing a ventilator, and it is configured with settings that split the breathing evenly to both while they are alive, what will the flow change to for B when A dies?

      My intuition is that making use of this would be very situational. a) You’d want an in hospital fab shop, with some assurances for both printing quality and sanitation. b) You’d need enough lead time that, yeah, we will need to take this short cut, to get the things printed, perhaps tested, and maybe one or two rounds of cleaning. c) My intuition is that should Covid prove bad in the US, it will be closer than you often come to having enough lead time. d) The engineering on a splitter is faster and cheaper than the engineering on a liberty ship version of a ventilator. Could the actual drawbacks of a splitter be enough that if we plan for mass use of a splitter, we want to be working on a liberty ship vent?

    5. TM Lutas Says:

      BobtheRegisteredFool – I brought up this because it’s been looked at informally in the professional community for at least half a decade and nobody outside the community seems to know about it. The only explanation I can figure out is that nobody wants to get crosswise of the FDA and admit what they’ve been doing so we have a communications problem and a regulatory problem but probably not an engineering problem. I don’t think that I’m better at engineering a medical solution than an MD.

    6. ScottJ Says:

      Any competent metalworking facility should be able to weld these types of things out of sterilizable Stainless Steel fairly quickly. Every SCUBA tank/regulator setup is in effect an air under pressure delivery system. One of the great strengths of America is our ability to innovate. Our best hope is to figure out quickly how to safely get back to work and unleash the creative power of our people and our economic system.

    7. TM Lutas Says:

      ScottJ – This is not a manufacturing issue. You can make all you want in whatever method you please but if a doctor isn’t confident that their license will survive them putting the product to use, they won’t use it.

    8. Mike-SMO Says:

      As for fabrication, I’d start with Schedule 80 PVC fittings and work from there. The material is tolerant of most cleaning materials.

      You are going to run out of hose pretty quickly. That corregated stuff is almost impossible to clean.

      “Load balancing” is going to be a thrill. Then there is the limit of nurses and respiratory technicians. They are pretty hard to fabricate.

      Best bet seems prevention, “social distancing” and sanitation. Hide until the herd immunity level gets high enough or there is a vaccine. Let the others generate the antibodies for you.

      The modern ventilators have automatic this and that. You can fake some of that function until you run out of people who are not sick or exhausted.

      “Flattening the Curve” is a way to stay out of that crisis zone. Avoid! Sanitize!

    9. Grurray Says:

      Does anyone know the regulation that is stopping us from printing these manifolds and reducing the death toll from a local overwhelmed medical system?

      One you are looking for is the FDA’s USP Class VI approval that certifies materials for medical-grade biocompatibility. The material used for that part in your picture is the standard material everyone uses for 3D printing, and it’s not approved for medical applications.

      There are some 3D printing materials that are FDA approved. They’re a lot more expensive and not readily available in pandemic-size quantity.

      I don’t think most welding is going to pass muster either. They have rules about that too. It has to be special equipment for minimal impurities and special treatments. Your typical machine shops won’t be set up for it.

      This is a good solution for some other country with no regulatory oversight. For our country, we might see something like this come to market in a few years/decades.

    10. Jonathan Says:

      Maybe we have too many regulations.

    11. Mike K Says:

      Hard to believe that anyone is serious about this. The settings and cross contamination seem too complicated.

      Also, I assume the drug therapy will preclude the need for respirators.

    12. MCS Says:

      You would know more than I. I don’t see how it would work, maybe the theory is that it’s better than nothing.

      If you want drug therapy, stay out of Nevada. I doubt that it’s legal, since when does the Governor get to overrule the judgement of every doctor in the state. I can’t imagine what he thinks he will accomplish.

    13. Grurray Says:

      Maybe we have too many regulations

      No doubt about it. Similar to the accounting industry, there has sprung up and entire industry to support and certify FDA compliance. Many different interests have a lot of incentive to keep the regulatory regime growing. Someone mentioned ISO in their comments. There is a place for standardization, but too often the implicit goal is to systematize tribal knowledge in order to repackage it for resale and transfer to areas with low labor costs. People on the ground are still important and need to be trusted to make value judgements that the 10,0000 ft view can’t ever know about.

    14. MCS Says:

      There’s an industry around every standard. Mine for one and we use others to insure our own compliance with ISO 17025.

      If you or yours ever have to be hooked up to a vent, you’d probably want to know that it wasn’t built in somebody’s garage after watching a YouTube video. When you buy a drug, you expect that it has the active ingredient in the stated amount without things like insect parts or rat droppings.

    15. PenGun Says:

      This is a useful video about this: https://www.youtube.com/watch?v=G1zsE9_85i4

    16. TM Lutas Says:

      PenGun – Indeed, a useful video and I’ve incorporated some of that into an update. Thank you.

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