Mine aren't like that. They wake me up. There's no telling how long I have before they wake me up. Thing is, they happen only after I have been asleep. I can lay there while awake and still feel them and I'll rattle until I can't take it anymore and just get up. If they are at a level 1-3, I can turn over and usually go back to sleep. Anything higher and I have to get out of bed. Funny you should mention diaphragm because I seriously think mine is from injury to the phrenic nerve while taking meds and swallowing a huge gulp of air. The phrenic nerve controls the diaphragm and diaphragm controls breathing and when I did the second half of my sleep apnea test with the mask, I had no vibrations for a week and a half. I slept with my nasal cpap last night though and still had them so.......