make the device go sleep when watch not on hand ???

I have the 1st gen Watch Urbane. I had a Pebble time before that. One cool function it had was that, if the watch was idle for more than 30 mins (which basically means when you are not wearing it) it would go to sleep mode and disconnect itself from the phone. It would save a good deal of battery power both on the phone and the watch. Who needs watch notification when not wearing it?
Is it possible to achieve that in LG Urbane, or in general Android wear devices?