On Tue, 24 Jan 2012 17:02:09 -0000, "Bill Grey"
wrote:

All electrically operated life-support machines invariably have an
alternate power source that will switch in automatically in the event
of a mains failure.

Dream on!

I can assure you it is far from a dream. The only life support
machines that are not designed with such a backup are those that are
meant to be used exclusively in an environment where immediate human
backup is available at all times.

I would not even risk important *data* to the possibility of a mains
power failure, but arrange for a UPS and other failsafe measures. I
can assure you that if any of my family or friends' lives depended on
the operation of an electric machine, I would ensure that their lives
would not be ended as a result of a power cut. YMMV

--
Cynic