[fencepost]

There's only so much that can be done with a motion sensor and heart rate data. Personally I try to burn the candle enough that if I'm in bed I should really be sleeping. I can read on a couch with a cat.

If you are going to be reading in bed and want better sleep detection, try using the hand with the watch for page turning, or if it's a device and you just tap to turn pages try holding it with your watch hand. Just that motion may be enough for it.