Powered AirPurifying Respirators (PAPRs) are effective pieces of Personal Protective Equipment (PPE) that could be helpful to caregivers. PAPRs will also be in extremely short supply and are much less risky and less controversial than a DIY ventilator. You also may be able to save many more lives by building a PAPR that protects a caregiver than a mediocre ventilator for one patient.

Visit the Github Project Link
https://github.com/jcl5m1/ventilator/...

Prusa Face Shield
https://www.prusaprinters.org/prints/...

CDC Strategies for Optimizing the Supply of N95 Respirators: Crisis/Alternate Strategies
Includes when the recommend using certified PAPRs. Note, this is not a certified PAPR.
https://www.cdc.gov/coronavirus/2019...

Rengasamy S, Eimer B, and Shaffer R. Simple respiratory protectionevaluation of the filtration performance of cloth masks and common fabric materials against 201000 nm size particlesexternal icon, Ann Occup Hyg. 2010;54(7):78998.
https://www.ncbi.nlm.nih.gov/pubmed/2...

I made a mistake in the video. This is the data behind the chart shown and is not the study referenced by the CDC.
image credit comparing usage of home materials
https://smartairfilters.com/en/blog/b...

Cambridge study underlying the chart shown.
https://www.researchgate.net/publicat...