Do you consider a person in a coma living or dead?

(N/A) $\rightarrow$ In human beings,it is difficult to define the living state. For example,patients lying in a coma,supported by machines that replace heart and lung functions,are brain-dead with no self-consciousness.
$\rightarrow$ Some of these patients never return to a normal life.
$\rightarrow$ They can neither be strictly called living nor non-living or dead,as they lack the defining characteristics of a living organism like self-consciousness,yet their metabolic processes are artificially maintained.