Do I have to lie in the middle of the bed during a MedBed session?

No. The 90.10. MedBed doesn't care where you lie in bed. It recognizes your lying position fully automatically and adapts to it.

You can lie in the middle, on the left, on the right, diagonally, upside down, on your back, stomach or side. You can also sit. In fact, you could even do a headstand in bed. But we don't recommend that, because it's certainly not very relaxing. Being relaxed while using the MedBed is the most important thing.