There are a lot of people out in the DYI space right now that are working to make various DYI or Pandemic Respirators. I started doing some research on it, and decided to take a crack at it myself.
There are several different approaches that are splintering out right now.
These guys are the most organized. They appear to be taking Ambu-Bags and making them automated. Their approach is to make it as close to hospital grade as possible, and have specific requirements for designs, designers and anyone looking to help: https://www.facebook.com/groups/670932227050506/about/
There is this approach that is very end spectrum DIY - what I would say would be zombie apocalypse style DYI ventilator. They are coming from the point of view of how to build one if supply chain aka Amazon gets hosed and you have to build it from parts raided from homes. https://www.instructables.com/id/The-Pandemic-Ventilator/
I personally, am attempting to build my own version of the latter, using supply chain parts, a raspberry pi and a 4 channel relay. My version that I am building is mostly to calm my anxiety by giving me something to do that feels useful even if its probably not. It's built to work completely on 12v, so it can work in a car or run on a car battery. It uses a Mask instead of throat tubes, which is not as effective but does not require medical intervention to start the vent. Its designed to cost under $200 for everything, but makers probably have most of the stuff lying around. It's also designed so that doesn't use any super specific parts, meaning the parts can be sourced locally, and when this all goes away, the parts can be used in other projects.
I'm going to be using my 3D printer to adaptors to make my 3M filter mask into a ventilator mask.
Over the next week or two I will hopefully document a full build of a working prototype DYI respirator. Input is welcome
More Information to follow.
Parts Needed (In Theory)
Valve 1 - $27
Valve 2 - $36
Valve 3 - $32
4 Channel Relay - $8.00
Reed Switches (qty. 10) $13 --- Only 2 needed
Whoopee Cushion (qty. 12) $13 --- A Whoopee Cushion? Yep - This should make a great Bellows
12v Air Pump - $6
12v to 5v converter - $10
Raspberry Pi (Or Arduino) ~$35
Random PVC Tubes - ~$10
Some Plywood, and various screws, and hinges
12v power supply ---- Car / Car Battery or 12v Power Supply