I suffer from nocturia (diagnosed as non pathological after many rounds of tests all turning up negative).

In a typical night I get five hours max of contiguous sleep and have started sleeping (by that I mean the in bed duration) nine to ten hours as an attempt to compensate for not being able to stay asleep.

I've always been curious about the difference between time spent in bed and actual time in deep sleep and their equivalence.

Also for anyone with an Android phone that is interested in tracking sleep the app Sleep As Android is really great.https://sleep.urbandroid.org/