A man strangled his wife because he falsely believed she was abusing their two-year-old son, a court has heard.
Muhammad Malik, 38, killed his wife Asia Tufail, 32, on 22 November 2016 at their home on Perne Road, Cambridge.
Malik called police and told them: "I'm afraid I've taken her life. You need to come and get me".
He was given a hospital order at Cambridge Crown Court, after admitting manslaughter on the grounds of diminished responsibility last year.
He had faced the charge of murder but his plea to the lesser charge was accepted by the prosecution and Judge David Farrell QC recorded a verdict of not guilty to murder.
'Pushed to my limits'
The court heard the phone call made by Malik to police in which he said: "Hi, my wife has been abusing our child, like, physically and sexually and I'm afraid I've taken her life.
"You need to come and get me."
There was no evidence to suggest any such abuse had taken place, the court was told.
Their two children, one two years old and the other just three weeks old, were in the house at the time of the killing.
Psychiatrists agreed Malik had a "delusional disorder" and the court was told such illnesses are "notoriously poor in prognosis".
Judge Farrell QC said on sentencing: "I accept that your treatment, together with protection for the public, are better served by order under sections 37 and 41 of the Mental Health Act - imprisonment is not an option here."
He told Malik it was "in the public interest" that his "future release is governed by [Mental Health Act] rather than by a parole board".
Malik will only be released with a comprehensive care package and under the supervision of the community mental health team, said police.
Consultant psychiatrist Dr Raman Deo said treatment for Malik's disorder could take up to six years if he engages properly.