For a lot more on this topic than you ever wanted to know, I highly recommend Dick Teresi's "Brain Dead". It's a scary and fascinating look at the so-called "death determination" industry that addresses one of our society's least-asked questions: in an era of unprecedented medical skill and technology, who draws the line between life and death, why do they draw it there, and how much are they getting paid?

https://www.amazon.com/Undead-Harvesting-Ice-Water-Beating-H...