There actually are monitors that you can currently buy that sounds an alarm when the baby's blood oxygen dips. I think one is called the Owlette, I almost bought one when my daughter was born because I was so terrified of SIDS.
Here is another one I found: https://www.mylevana.com/products/oma-sense?gclid=EAIaIQobChMI2t6Dvcrc9wIVx9aGCh3y-wmMEAAYASAAEgKh6vD_BwE
Those types of monitors are a bit of a grift though, they are all super expensive so lower income moms would be hard pressed to buy them, and there is zero liability or quality control generally attached to them.
I think an apnea monitor would work. An alarm goes off if the baby stops breathing to hopefully wake the baby and alert the parents.
A baby in my family had to have one for a few months. Technology may be even better now.
It would be interesting to know if a person would grow out of it or not.