Edward Flaherty, 74, was convicted of strangling his 69-year-old wife Ina with a tie after she refused to give him money to go out drinking.
But Lord Matthews said that his dementia made him unsuited to prison and instead imposed a one year restriction of liberty order which will keep him inside his home during opening hours.
He will be tagged and banned from leaving his home in Glasgow between 11am and 11pm after being found guilty of culpable homicide.
The sentence comes after changes to the murder laws in England and Wales were announced last week which will mean that husbands who kill nagging wives will no longer be able to claim they were provoked.
The reforms were designed to ensure that domestic violence is treated like other forms of homicide. The claim of provocation was said to be used by most male defendants who were denying murder of a female partner.
At the High Court in Glasgow, the judge told Flaherty: "You were found guilty of the culpable homicide of your wife who you were together with for many years. In normal circumstances this would attract a prison sentence in double figures.
"I have read and considered a number of reports from experts. It is plain to me that if I were to impose that sort of sentence you would be released in a very short time because prison would not be able to cope with your condition.
"Sentencing you would just be a token gesture. I am anxious to impose a sentence that restricts your liberty.
"You still go to the pub where you went with your wife. That must annoy her relatives. Not being able to go there will be a more meaningful disposal than a prison sentence which will not last long."
Flaherty went on trial last year accused of murdering his wife but was convicted by a jury of the reduced charge of culpable homicide.
The jury was told that only slight pressure around Mrs Flaherty's neck could have caused her death because of the condition of her arteries.
The pensioner, who has had three heart attacks, could not remember who the Prime Minister was when he was questioned at the time of the killing last April and called him "that curly headed bloke".
Some jurors wept as he told the court that he and his wife had a "strong and firm" marriage which lasted 52 years. He had never once struck her, and she had never hit him.
During the trial he said he had no recollection of the moment he strangled her. But when asked who had killed her, he said: "It must have been me. There are no ghosts running about the house who would have done that."
Donald MacLeod QC, defending, said reports prepared for the court painted a picture of a man in "significant physical and mental decline".
"There is a clear diagnosis of dementia setting in. It is a progressive condition and ultimately he will need 24-hour care.
"I am deeply conscious there has been a death here, but this man is very unwell. He was always willing to plead guilty to culpable homicide, but this was flatly rejected by the Crown and that is why a trial was necessary."
MPs have expressed surprise at the verdict. Philip Davies, the Conservative MP for Shipley, said: "I can't see how it can be right that the punishment for murdering someone is to stop that person from going to the pub.
"Most people would find that offensive. What kind of message does this send out? What will people think will happen to them if they murder someone?"
David Davies, the Conservative MP for Monmouth, said the verdict was a disgrace.
He said: I would have thought I have heard everything but this is one of the most lenient sentences I have come across. Its crazy. He should be sent to a mental health establishment if he has a mental problem.