Check out 4:40 of the YouTube video, finally a comfortable,
cheap and user-friendly device that saves you from sleep apnea!
https://www.youtube.com/watch?v=bWvGn85S5WE
On a related note, never sleep on your back, as you may be
suffering from sleep apnea (which
causes brain damage, cardiovascular disease, high blood pressure,
strokes and heart attacks) without even realizing it.
http://greatist.com/happiness/best-sleep-positions