It works!

So I adopted a peculiar method: tie a knot around the device, adjust the knot to make it fit on your arm, and set it to wake you up, or give you a chance for an RC, during your REM period.

One tip; the more complicated your knot, the more likely you won't do it without thinking


I guess this could be applied to sleepwalkers; tie a knot around your feet?
Just make sure you can undo it quickly when conscious so if there's an emergency you can get it off quickly.