Imagine a design free to the world
Well, Imagine no more. This solution exists now and has been proven to work.
A few 16 year old high school youth raised $1,000 using gofundme.com in less than 24 hours to build the OxiKit DIY o2 concentrator.
They then went to www.oxikit.com and bought parts listed from local hardware stores and online.
They followed the step by step video instructions.
They downloaded the free code from the website onto a laptop. Then used a common basic usb cable to connect the laptop to the small Arduino Nano 33 iOT hub, an all in one computer chip to operate the OxiKit.