I use Emfit QS Sleep Tracker, there's a special app with all the info needed. Have no idea why but I do not trust these headbands like Dreem 2. Actually a lot depends on the mattress. I had some regular pains in the neck area and then purchased set of memory foam mattress and a couple of pillows of the same material, and the feeling when you are almost sinking in the bed is really relaxing. Look here, I bought Layla, but that's a fancy one... And you put your Emfit tracker under the mattress and place data receiver nearby and in the morning just check how was your sleep.