I'm going to assume Coulson's body is in suspended animation dead. But that the device protecting him is like Odin's sleep chamber and is trying to repair the dying cells in Coulson's body. If I recall, Coulson's body had spent 3 minutes dead, as per some dialog spoken on A.o.S. Isn't 7 minutes irreversible death in humans?
I am assuming the sleep chamber does not have the ability to restore a dead body back to life. But that it could, at the very least, suspend death in dying cells. So that Coulson's body lies in a state exactly between death and life. 3 minutes dead is not alive, but neither is it irreversible death. And that Nick Fury probably gave everyone a very heavy-handed speech that they had no other option other than to jury-rig the sleep chamber to restore dying tissue. This is a big opportunity for the show to deal with death. And to showcase how sometimes it's possible to circumnavigate around death if one is very, very, very lucky.