It's told from the perspective of a prisoner who has served hundreds of years and they won't let him die. Any suggestions?
The viewpoint character is Oliver Symmes, a murderer, the first convict to be sentenced to eternal life in prison:
"Oliver Symmes, there has been no taking of human lives in this nation for many years, until your shockingly primitive crime. We had taken pride in this record. Now you have broken it. We must not only punish you adequately and appropriately, but we must also make of your punishment a warning to anyone who would follow your irrational example.
"Naturally, we no longer have either the apparatus to execute anyone or an executioner. We do not believe that a stupidly unreasoning act should incite us to equally unreasoning reprisal, for we would then be as guilty of irrationality as you.
"We must establish our own precedent, since there is no recent one and the ancient punishments are not acceptable to us. Therefore, because we are humane and reasoning persons, the Court orders that the defendant, Oliver Symmes, be placed in the National Hospital for observation, study and experimentation so that this crime may never again be repeated. He is to be kept there under perpetual care until no possible human skill or resource can further sustain life in his body."
He is resuscitated repeatedly, after death by suicide
"That was a nasty thing for him to do."
"They all do it, once or twice, until they learn."
"Third time for him, isn't it?"
"Yes, I believe so. First time he tried hanging himself. Second time he was beating his head against the wall when we came and stopped him. Bloody mess that one was."
"Nothing to compare with this, of course."
or from natural causes:
Diabetes, tuberculosis, cancer of the stomach, tumor of the brain. He'd had them all, and many others. They had swarmed to him through the gouged skin-openings made by the gleaming needle. And each had brought the freedom of blackness, of death, sometimes for an hour, sometimes for a whole week. But always life returned again, and the waiting, waiting, waiting.
We don't know just how long he's been in:
Oliver Symmes turned to face the ceiling, his mind full of dusty whispers. What century was it? She hadn't answered. It might have been a hundred and fifty years ago he came here, instead of just fifty. Or possibly two hundred and fifty, or . . .
This sounds like the book "I have no mouth and I must scream".
It follows the perspective of one of the subjects, but its not a prison in the conventional sense. Humanity was killed by a massive insane AI. The AI spared like 5 people so it could torture for all time. Its horrifying.