This is a prototype design of an ventilator designed for emergency use when no other option is available, and a tool is need that might help save a life.

It is made with minimal parts that you might be able to have access too even during quarantine. Besides the parts you need to print, the only other parts you will need are m3 bolts, a computer fan, and tubing for the air flow. The fan operates a piston which switches valves. This allows this ventilator to blow air in, and then extract old air from the lungs. The computer fan also blows and moves the air through the system.

The way the design was made is modular, it will allow for more than one computer fan to be used in series if the system needs more power. The system was built to run off a 4000rpm 12v commonly available computer fan with and 85:1 gear ratio, providing a 47 breath per minute count. That is a bit high, but I expect the gears and piston should slow that. Ideally you will be able to vary the voltage source with a variable resistor, although that is not required.

This system is not tested at all. I am handing if off at this point to the community so that more minds can critique it, add to it, and make it more practical.

A few things I am thinking of at the moment are the fan gear that is used as the first gear in the transmission. It is the same as gear two, but it has fan blades to help with air flow, and prevent a stall behind what would otherwise be a solid gear. I am not sure if gear 1 should be a fan, or if gear 1 an 2 should share the same solid shape. Only testing can show that I suppose. The other gears are solid and not spoked, to prevent drag from paddle shaped spokes. Although if someone can create a minimal surface area spoke design that may print faster and work just as well.

I would like to clarify that because this is plastic and has gears, a filter should be used down stream, between this and the ventilator to filter and dust or particles from the machine. I am not a doctor, so I cannot provides instructions on how this can be used on a patient.

Both STEP and STL files are available.

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