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Establish instructables for respiratory and other essential equipment to fight COVID 19 (corona virus) Answered

Hey all, I urge the makers/instructables community to push to make as easy as possible instructables to make essential and missing equipment in the hospitals (respirators,..) with easily accessible materials. Let's do it!


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9 months ago

hello! i am to young (double digits) to know what u all re talking about but i just wanted to tell you ll that "STAY SAFE NO GOING OUT SIDE NO DRINKING FROM WATER FOUNTAINS" i got that from my big bro when i was about to drink from water fountain and my older brother yelled at me. but i know why! because he is a loving and kind brother who wants me and the rest of my 4 siblings to be safe!


1 year ago

I'm not good with a sewing machine, but wanted to share 2006 article detailing how to create an ad-hoc respirator using a cotton t-shirt. The authors tested the prototypes using qualitative fit-testing and found that it was effective. Of course, it's no substitute for real PPE but certainly better than none at all. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373043/

t-shirt respirator.png

1 year ago

Mmm, a ventilator is more complex. the pressure is critical as you can easily damage the lungs.
Generally once you push a tube down someones throat they try to push it back out and cough.

To prevent this the patient is paralyzed with drugs.

Because they are paralyzed which is somewhat scary they are also deeply sedated.

As a machine they are very costly and complex although at their heart they are a simple bellows pushing and sucking air.

I don't think this is a DIY project for the average handy man. Although I have no doubt that given a set of plans the likes of Old Tony etc could do it.

To be honest the best thing anyone can do is keep themselves out of Hospital so the beds and equipment are available for those who fall ill and really need them.

A significant number of patients world wide have died because of heart failure associated with viral Pneumonia.

Sadly another DIY idea often used is to design and cheap protective mask people can wear. A virus particle (they are not alive) is on the Nano meter scale. Most filters can not stop them so a DIY mask with layers of cloth, activated charcoal or paper towel isn't going to work.

Just possibly bubbling your breath through a liquid, ideally a sterilising liquid might do some good.

When people sneeze they eject millions of water droplets which contain virus particles. Thes may be stopped by a simple mask BUT they generally drop to the ground very quickly under gravity because they are relatively heavy.

Usually a mask is best applied to the one who is sick to prevent them ejecting these droplets into the air. Surgical and medical masks are worn for the same reason not to protect the patient but to stop the doctor/nurse breathing over the patient and giving them more problems.

A full hasmat suit will have HEPTA filters or be self contained, these trap very small particles typically around
3 uM by electrostatic attraction to the filter fibers rather than a very small mesh size. Usually they say 95 to 99 % of > 3 micron particles will be trapped. however you only need a single Virus to get through.

Don't mix in large public groups
Don't touch surface others will have touched before you
Don't touch your face at all
Wash your hands regularly. EVERY time you go out and return. When you enter a building and when you leave.

The virus enters the body through the mouth, eyes or nose assuming you not getting a contaminated blood transfusion.


1 year ago

I agree that this is a great idea.

I'd like to start the ball rolling with a few ideas. First, let's discuss what a ventilator does, and break it down into it's component tasks, and then discuss how those could be replicated with non-medical devices.

I'm not involved in the medical field at all, but from what I've read, a ventilator:
- Blows air into the patients lungs
- Patient usually exhales on their own, but sometimes the ventilator does that for them also
- The ventialtor needs a way to administer oxygen from a tank as part of the inflowing air
- The air also needs to be warmed and humidified before entering the lungs

Now, when I was first thinking about this, I started thinking about a player piano.

If you ever have studied how a player piano worked, you would pump foot pedals and that would create a vacuum with bellows, this vacuum could be used for many tasks, it would turn a roll of paper which activated the keys, and the vacuum also activated each key when the roll of paper told it to. So it was a very simple, yet very complex device, made of only wood, leather, brass, and a few steel parts, nothing electrical and nothing that required complex machining.

I was thinking the same sort of bellows system could be used for a ventilator. Obviously you would need something electric to replace the foot pedals, as it would be impractical to have someone pumping foot pedals 24 hours a day, but the rest of it seems very straight forward. Generating vacuum would be easier than generating pressure, as you can build a spring operated reservoir which would hold the vacuum at a more or less constant pressure. All player pianos had this. Then if you built a sort of see-saw mechanism with two air chambers, the vacuum applied to one side would cause pressure on the other side. Player pianos had two foot pedals each with it's own bellows (actually technically called an exhauster) and when you were pushing on one and creating vacuum, the other was resetting itself. You could do the same thing with this see-saw mechanism, in fact, you could probably set it up so it could do two patients at once, with each side alternating pressure and vacuum. You'd have to make some sort of flexible diaphragm, which would be tough enough to stretch millions of times and not break, but flexible enough that you could get the right amount of air pushed into the lungs. Maybe a diaphragm made of that rubber shower pan liner? I've used that for other projects and it's relatively tough and still pretty stretchy for it's thickness. I've never used it for something like this however so it might not be the right solution.

Then once you had the pressure/vacuum mix both in speed and intensity/volume, then the only thing else you would need is a way to humidify and warm the air, but it seems to me that if you had a warm water bath, and had a simple clean dishrag stretched taut, with one end in the warm water bath, then capillary action would pull the warm water up over the dishrag, and if you were pulling air through that dishrag then the air would be warmed and humidified at the same time. I don't know how you would regulate the warm water bath though. Maybe with a fish tank heater?
The other problem would be monitoring all this. Obviously in a perfect world we could set up Arduino or Raspberry Pi to thermocouples and be able to read temps and humidity and pressure and vacuum, but this is going to need to be a battlefield sort of setup, so there is no way to make it that complicated. Making a water gauge for pressure or vacuum is simple, it's just a tube filled with water with inch markings on the side and the pressure or vacuum with push or pull the water in the tube and let you know how things are going, but I don't know a quick and easy way to monitor temperatures or humidity. Something like an oven thermometer would be nice, but those don't operate in the 70-110 degree range that we would need. Someone smarter than me would need to conjure up a solution to that part of the problem.
Then the last part of the puzzle is making it a standardized design that anyone with a sheet of plywood and a CNC machine can churn out. It needs to be quick, built from the thinnest and lightest materials possible, preferably plywood, as that is pretty much available worldwide, as opposed to lexan or aluminum or anything else that may not be obtainable. It needs to have unique connections between parts, so that it will only fit together one way and one way only, as many people assembling it may not have the time or expertise to read complicated instructions, so every part needs to be painfully obvious where it fits. It needs to have a locally sourced motor of some sort, which has a standard base. I don't know what that would be, maybe a windshield wiper motor? Seems like that would be available anywhere, it runs off of 12v which can be sourced anywhere in the world, and I think if you picked a common vehicle which was available worldwide, like a Nissan or something, it would be easy to make a common bolt pattern hole cutout which would be usable anywhere in the world.

I'll be very interested to hear everyone's thoughts.