Critical Ventilator Shortage

The last couple months I have been participating with the development of our hospital's pandemic flu plan in compliance with recommendations by the Department of Health and Human Services. Among other issues, we discussed a critical ventilator shortage in even a mild pandemic. Restating the problem: the US has 100,000 vents, and the flu pandemic could produce 3 million or more vent-dependent patients. Since our meeting I have been researching simple vent designs which could be cheaply produced and stockpiled or "MacGyver'ed" from components found at a hardware store and in the hospital. So far we have been discussing:

Emerson ventilator http://www.jhemerson.com/pdfs/Branson%20-%20A%20tribute%20to%20John%20H%20Emerson%20
Bird mini-ventilator (Percussionaire/Oscillitron)http://www14.inetba.com/percussionaire/oscillitronpage.htm
Multiple people on single vent
Sommer DD, Improvised automatic lung ventilation for unanticipated emergencies. Crit Care Med. 1994 Apr;22(4):705-http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8143481&query_hl=3&itool=pubmed_docsum
Magnet and Bobbin MiniventCohen AD, The minivent respirator. Anaesthesia. 1966 Oct; 21(4):563-8.
HFOV using modified portable air compressor
HFOV using modified oil vs diphragm air compressor
HFOV using modified shop vac or other vacuum
HFPPV using modified shop vac or other vacuum
HFJV using modified portable air compressor