Is it possible to make a non-invasive ventilator?

[Bobby Logan]

Cuirass or Curass ventilator.

[Roger Feeley]

All ICUs already have non-invasive ventilators. They are insufficient for the kind of respiratory failure that SARS-CoV-2 (the virus causing COVID-19) causes, so the current recommendation for severe cases in the ICU is to intubate as early as possible. What's scary is that people are recovering from the respiratory failure only to die from as-yet-unexplainable heart failure. That report got my attention!

well nuts!
Amateur Hour ventilator with intubation scares me.
Roger, could you please provide a link for that report?

[roger wiegand]

well nuts!
Amateur Hour ventilator with intubation scares me.
Roger, could you please provide a link for that report?

Haven't seen it in any official way yet, it was taken second hand from a FB post from a doc taking care of Covid 19 patients in the Seattle area, so anecdotal and not verifiable. I should not have posted it, and I apologize. There was a paper in the Lancet a couple days ago about co-morbidities in Wuhan, underlying heart disease is an indicator of poor prognosis, but that's not the same thing.

The full post is quoted and discussed in the comments on this blog post.

[Roger Feeley]

Cuirass or Curass ventilator.

Bobby,
wow, that interesting. It’s sort of a portable iron lung. I’m not a doctor so I’m hoping one will jump in here. It seems to me that there’s a functional difference between inflating the alveoli with positive pressure and manipulating the abdomen to draw in air. As I understand this virus, the reason ventilation is required is pneumonia which is liquid in the lungs. They talk about three different classes of alveoli. There are the ones filled with gunk and can’t be helpful. There are the unaffected ones. The, in the middle, there are ones with some gunk and are kind of collapsed. I read about how they sort of give the lungs an extra hard jolt of air to inflate the iffy ones and get them going.

So they aren’t just using a ventilator to do routine breathing. They are also using it to increase the lungs ability to exchange oxygen.

This is really interesting stuff.

[Myk Rian]

What's scary is that people are recovering from the respiratory failure only to die from as-yet-unexplainable heart failure.!

I've been in heart failure for several years now, so I have to be extra careful. Hand sanitizer in my pocket at all times.

Interesting conversation topic. I was going to suggest an in a pinch possibility using a small squirrel cage fan, but Edwin's HPLV idea is a good one.

[Bobby Logan]

The curass ventilator is non-invasive and is similar in function to an iron lung. Looks like a turtle shell. By "sucking" the abdomen and rib cage out, they allow airflow into the lungs. Negative pressure vs positive pressure (PAP). Don't know enough to even start to find the plumbing you'd need to make 1.

[Eduard Nemirovsky]

Very time sensitive and interesting topic. Right now in the USA only 94,837 ICU beds and not every bed has ventilator. Maybe 74-75 thousand vents for ICU setting. Maybe another 35-45 thousand operating room ventilators. Assuming around 8% from infected would need acute critical care - we are good to cover all ventilators needs.
Ed.

[Roger Feeley]

Very time sensitive and interesting topic. Right now in the USA only 94,837 ICU beds and not every bed has ventilator. Maybe 74-75 thousand vents for ICU setting. Maybe another 35-45 thousand operating room ventilators. Assuming around 8% from infected would need acute critical care - we are good to cover all ventilators needs.
Ed.

Ed,
I would imagine that the number of ICU beds and ventilators you quoted include those that are in use for other illnesses. The question would then be how many spare ICU beds and spare Ventilators are available to serve Covid patients? I think it’s fair to exclude the units in operating rooms because, again, those are there for a purpose.

Right now the name of the game is,”flattening the curve”. Assume some number of infections. If they all happen at once, the medical system is overwhelmed as it is in Italy. If we can stretch the same number of infections over a long period, the medical system can absorb the load.

[Roger Feeley]

This has been fun. My daughter works for the justice department here in DC in the Office of Legal Counsel. I reported to her what I found online and what I learned here. She sent an email to her boss who is deputy attorney general. She also noticed that sen. Marco Rubio had commented on a potential shortage in icu beds and ventilators so she emailed him as well. She knows him from some previous legislation that they worked on. I guess it pays to know people. We’ll see what happens.

[Mike Soaper]

Many moons ago, perhaps in the early 90's, I was working in a research lab that did a one time diy try of making a external/curass type ventilator. It was made of fiberglass and resin, given the shape and the green color of the resin we also called it a turtle.

If I recall correctly one of the bigger issues then was getting a workable vacuum seal between the shell and the skin of the subject because of varying body shapes.

[Tyler Bancroft]

Very time sensitive and interesting topic. Right now in the USA only 94,837 ICU beds and not every bed has ventilator. Maybe 74-75 thousand vents for ICU setting. Maybe another 35-45 thousand operating room ventilators. Assuming around 8% from infected would need acute critical care - we are good to cover all ventilators needs.
Ed.

Estimates are that ~20% of cases will need hospitalization. Most hospitals in the industrialized world run pretty close to (or at) capacity. The world needs more ventilators, right now.

[Wade Lippman]

Anyone who has ever used, or slept next to someone who used, a CPAP will have no trouble thinking of one possible solution.

Then there's SCUBA gear.

Years ago I developed acute pneumonia from a bad reaction to anesthesia. They put me on what I suppose was a ventilator that was very much like scuba gear. Always wondered if you could substitute.

[Larry Edgerton]

Two small Festool sys Hepa vacuums hooked to a two canister spray mask. In between is a rotary valve with adjustable speed switching the mash from pressure to vacuum. Air going in is clean, air coming out is clean> I could build a rotary valve, still thinking about how to rotate it slowly enough? Or a slide valve, could be operated by hand if need be.

[Malcolm McLeod]

I drove my daughter to work today. We often go on some intellectual exercise and today it was whether it would be possible to make a home brew ventilator. we read about Italy running short of ICU beds and ventilators.

Let’s assume that we have all of Home Depot, Woodcraft and a welding supply at our disposal. Let’s further assume that we have a full wood and machine shop at our disposal. Finally, we can assume that, for a short while, we can have an attendant.

in my case, I also have several Arduino microcontrollers on hand as well as the stuff to drive relays. I also have a Microcenter nearby for electronics. Leveraging Home Depot, that gives me sprinkler valves to turn air on and off.

reading about ventilators, there is a lot of nuance and sophistication there. I’m thinking that if operate on the assumption that we have nothing to lose, we can dispense with the details and make something very basic.

feedback is important. We happen to have an Owlet which is a pulse oximitry device for infants. It would be easy to tape the sensor to a hand or foot.

ideas? How basic could you get to save a life? The assumption is that there is no alternative and that something is better than nothing.

The first thing that comes to mind, "How can this go wrong?!" Or maybe that old mantra, "First, do no harm." Often times, nothing IS better than something.

Use a vacuum? Really?!? Who here knows what happens to the human lung when you apply 100"H2O of vacuum to it? How about just 30"H2O? Anybody want to speculate? ...How about volunteers for the beta-test??

I'd recommend y'all leave the practice of medicine to the Docs. Or at least first make sure your shovel is all primed and ready, with a spot for a grave all lined out in your flower garden. Maybe even dig the hole ahead of time? - - YMMV.

[Larry Edgerton]

Lighten up dude, I'm pretty sure no one here was actually planning on building a ventilator. You take yourself way too seriously.