0134 GMT January 27, 2020
Benjamin Schreiber, 66, was sentenced to life without parole in Iowa for bludgeoning a man to death in 1996, BBC News reported.
He said his sentence ended when his heart stopped during a medical emergency four years ago, even though he was revived.
But judges said Schreiber's bid — while original — was "unpersuasive."
They said that it was "unlikely" to be dead, as he had signed his own legal documents in the case.
In 2015, Schreiber developed septic poisoning as a result of kidney stones. He had to be resuscitated by doctors in hospital, but fully recovered and was returned to prison.
In Schreiber's claim, filed last year, he said that he had been resuscitated against his will, and that his brief "death" meant that his life sentence had technically ended.
The district court ruled against Schreiber — a decisions his lawyer took to the state's court of appeal.
On Wednesday, the appeals court upheld the lower court's ruling. It added that his sentence would not end until a medical examiner formally declares him dead.