Planning the Prototype Build for the Pandemic Ventilator

Now that I have a basic design laid out, I will move on to building a prototype. To aid in planning development I will break the design down into functional sub-units.

I will start on the most complex component to physically build. That is the bellows unit. I will have to do some trial and error to determine the best physical shape. I intend to not have the bag fully inflate and deflate on each cycle so that there will be less fatigue on the plastic. I will have to see about how best to contain the edges of the bag so that it does not get pinched in the moving portion of the bellows.

The manometer is fairly straightforward. The main concerns are getting the optimal tubing lengths and vertical positioning. Possibly I may have to adjust the diameter and length of the tubing at some points of it so that the water is not sucked into the patient circuit.

The rest of the airflow circuit is easy to build. I will use switches to control the valves to bench test the circuit without a PLC unit initially. I will cycle the valves manually with the switches.

Next is to add the PLC and magnetic sensors and get the unit to cycle automatically. Once the system is functioning at a basic level, the alarm software can be added to the PLC and tested. I have only rudimentary PLC programming skills myself, but I know several people that can help me on this.

Next will be the PC control/monitor integration. I have not really thought this far ahead yet. I have a pretty good idea of what I want it to do, but am not sure of the best approach to achieve it. I will take pictures and video of each step and post them. Hopefully by the time I am able to demonstrate a basic system functioning, I will have a programmer interested in doing the PC portion of it.