Prison is a very costly way to punish people. Today’s invention is a new mode of applying it to criminals who are not thought an active danger to society.
A continuous sentence, which allows prisoners to adapt to the stress of imprisonment and to establish unhealthy, institutionalised patterns of behaviour, would be replaced by discrete periods of time ‘inside.’ Perhaps one month in, followed by a month outside.
This would also help maintain relationships with friends and family, who would probably have to help support prisoners, due to the difficulty of working during irregular periods of freedom.
Although this might appear an easy option, I suspect that the intermittency would keep prisoners emotionally more aware of their debt to society, and thus become recognised as an effective deterrent.
The good news is that certain prisoners would serve a sentence which involved substantially less total time behind bars, reducing the cost to everyone else enormously.