Standalone full support wearables


I’m looking for stand-alone implementation of Sleep as Android on wearables supporting accelerometers, heart rate monitoring and/or other sensors, because I don’t want to sleep every night with Bluetooth on around my head. I’m also curious about syncing the data on such standalone devices, how does it sync with SAA main app on main mobile device?

So in general this is what I need:

- supported standalone wearable(s) running Android (or not) with HR monitoring and other sensors
- no constant Bluetooth connection needed while sleeping, only when syncing
- syncing of data with main SAA app on mobile phone

Please recommend any device(s) with such capabilities.