Reading the website you'll see that this equipment is to be used in a hospital by qualified people. According to a government study, there won't be enough ventilators available if a bird flu type scenerio occurs. Cobbling together a few more from off-the-shelf equipment will give the hospitals more resources.
I can see where my initial post suggests a untrained, unequipped person should make one of these.
In reality, a doubt anyone who isn't trained in their use would spend the time/money to build such a thing.
-Blast