Do you consider a person in a coma to be 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 normal life.
$\rightarrow$ They can neither be strictly called living nor non-living or dead,as they lack self-consciousness but maintain some biological functions through artificial support.