Companies like Angelcare sell a "baby movement monitor" sleep pad that sounds an alarm if the infant stops moving for 30 seconds. It's sensitive enough to detect movement from breathing alone.

There are a lot of them, but nothing replaces skin-on-skin touch. In our case, it was the only way we could get my daughter to sleep.

Negative reinforcement through shock therapy is both easy and failsafe (it will not physically harm the child).

I don't know much about babies, but the way you phrased it made sound like "Beatings will continue until morale improves" approach.