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

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

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

JK