Up thread a ways, I wrote about Dr. Alan Shewmon, and his research. Dr. Shewmon is a proponent of what could be described as an "integrated organism" theory of brain dead patients. He is well respected within medicine and bioethics, however most bioethicists seem to feel his ideas are controversial. He kind of leans in the direction as Dr. Paul Byrne in that he feels a brain dead body on a vent could still be considered an alive organism, but I think his ideas are expressed much better than Dr Byrne's, who, IMO, is more of a quasi-intellectual side show barker than a scholar. (Dr. Byrne's published articles are mostly vanity press, with no real peer review of his ideas. I can find no real bioethical research he's done involving people beyond the perinatal 30 days of life.)
So, like him or not, Dr. Shewmon has arguably done more REAL peer reviewed published research studying brain dead people with prolonged somatic support, and combing archives for retrospective research, than any other researcher or scholar I can find.
I came across this debate reply to some of his ideas a while back, and it seemed too esoteric to post back then. However, with the direction our current conversation has taken with regard to ethics, particularly with regard to the involvement of a Catholic health care system, I thought some might find this interesting. Note that both authors have employment/ involvement with Catholic institutions and philosophies, however their arguments are not based on religion, but philosophy of the intact organism, and the potential for sentience. They have some very interesting "thought experiment" examples included in their article, such as dicephalic twins, or a newborn with a headless parasitic twin. They spend a lot of the article addressing the degree of the integrity and completeness of the animal (human) organism, versus function of parts such as transplanted organs. It's lengthy at 10 pages, but I found it to be a fascinating debate.
If it's your thing, and appeals to you, enjoy the read! There are too many good quotes to pick one, and I don't want to take any out of context.
http://www.twotlj.org/OW-TotalBrainDeath.pdf