In 2006 a paper was published; suggesting that in a time of crisis a single ventilator could be used to supply oxygenation and ventilation to a set of patients:
A Single Ventilator for Multiple Simulated Patients to Meet Disaster Surge Greg Neyman, MD, Charlene Babcock Irvin, MD
https://onlinelibrary.wiley.com/doi/pdf/10.1197/j.aem.2006.05.009
In this study they experimentally demonstrate on test lungs that on both pressure and volume control mode you can sync up to 4 lungs and deliver reasonable ventilation and pressures required to sustain life -- at least for a couple of hours.
They stack their patients up in PARALLEL. That is; all patients get inhalation at the same time, and exhale at the same time.
A simple figure I drew is here:
They do this using a serial of 3 way junctions.
However, this system only functions if all the patients are supposed to get the same volume or pressure -- specifically they need to have similar compliance (stiffness) and volumes (usually based on their body weight).
People have described this process; and ways to optimize it; even though some societies are recommending against it -- however if the alternative is death I think ICU and ER docs are going to have to be a bit more flexible in the face of guidelines.
Check out EMCRIT's take on it with some FUNCTIONAL thoughts on the process; and counters to guidelines that recommend against it
https://emcrit.org/pulmcrit/split-ventilators/
Also check out the "how-to" guide with parameters from Columbia
Also, some schematics and how-do's done in video format:
However -- I'm going to take a sharp left turn and suggest a completely different way of doing things in another blog.
https://yourdesignmedical.com/blogs/ventilator-splitting-the-theory/vent-splitting-a-better-way