Do you think you have the same right to imprison your husband/wife/partner, or is it just kids you confine to their rooms?
If Dh had caught Covid then yes I'd have expected him to stay in the bedroom, with our en-suite, and not risk passing it on to me. I would expect him to follow the government guidelines to isolate from those in the household Wherever possible.
As his loving wife I'd have ensured he had everything he needed including food and drink.
If need be I'd have taken myself off and slept in the spare room and used the other bathroom to give him the space to himself.
Had he chosen not to of course I'd be unable to force him, just like you most likely couldn't actually force a teenager, so would have taken myself off to use the spare room and other bathroom away from him.
As it happens it hasn't been necessary. I caught Covid, not Dh. And I actually know my Dh too so I know he'd have isolated and kept away simply as he's a decent bloke who doesn't really want to see his wife ill if he can help it.
But IF it had I'd have expected him to do the right thing and isolate away from me and Dd, especially as I'm clinically vulnerable.
In our house we expect one another to follow the government guidelines to keep ourselves, the household and our family/friends safe and well. Self isolation guidelines come under this.