A 36-year-old who carried out a "sustained" axe attack on a female police officer has been given a 15-year sentence.
Pc Lisa Bates was left with a fractured skull, multiple ankle fractures and had her index finger almost severed following the attack in April.
"Dangerous offender" Nathan Sumner will be detained under a hospital order after being convicted of causing grievous bodily harm with intent.
Pc Bates had been attending a disturbance at his flat in Sheffield when the attack took place.
Sentencing at Sheffield Crown Court, Judge Adrian Goose said: "It was a truly shocking act of violence that you committed against her.
"I cannot be sure how many blows you dealt, but this was a sustained ... attack on a defenceless police officer.
"She begged you to stop and let her go. She believed she was going to be killed by you."
The court heard Pc Bates felt she only survived the attack owing to "luck and good fortune" - and that she had to cancel her wedding after the events of April 13.
In a victim impact statement read by prosecutor Samuel Green, she said: "The events of that day changed by life forever.
"Scarring to my leg and hand acts as a constant reminder of what happened.
"I continue to suffer from dizziness, headaches, nausea, nightmares and flashbacks.
"I am suffering from a loss of earnings and I have had to cancel both my wedding and honeymoon.
"It's only through luck and good fortune that I survived.
"His attack on us was instant, we had no chance to calm the situation."
The officer, 32, is still recovering eight months after the attack due to the severity of her injuries and remains unable to return to work at her base of Woodseats Police Station.
Sumner, of Plowright Close, was cleared of attempted murder but convicted of GBH with intent following a trial, during which it was accepted he attacked Pc Bates as he suffered from a psychotic episode.
Mitigating, David Brooke said his client was "profoundly ill at the time".
He added: "There was remorse and there was remorse from the outset.
"It's plain to us ... it's understood what he has done was wrong."
Speaking after the sentencing of Sumner to 15 years and a five-year extended sentence, Detective Inspector Paul Wilson said: "Pc Bates was responding to a routine call when she was violently attacked by Sumner and the devastating injuries inflicted upon her could very easily have been fatal.
"He showed absolutely no regard for the consequences of his violent actions and it's a stark reminder of the potential danger our officers face every single day, and I wish Pc Bates the very best in her continued recovery."