I suppose one could always have ones neurons mirrored into a sort of bio-synthetic matrix. Then gradually offload the processes to the "other side" key would be maintaining conscioussness at both sides until the original body is deceased.

Assuming this matrix doesn't deteriorate one could potentially exist until one tires of it.

I believe thinking about dying is worse than dying. If someone could give you the ability to be ignorant of death, would you take it?