As technology continues to develop, we are all faced with circumstances which did not before exist.
By way of example, a person's life can now be prolonged by technological means, long after any dignity continues attached to said life.
Through a living will an individual can set forth instructions to his family and medical providers that he wishes to be followed should such a situation occur.
Additionally, there is such a thing as a "do not resuscitate order".
These are things to think about and to discuss with your legal counsel.