The study swaddle is made of a cotton spandex material with a center zipper to unswaddle/swaddle without waking the infant and snaps at side and bottom to adjust to the size of the infant. The swaddle allows hip flexion/abduction and chest wall excursion. Arms are restrained at the side with loose internal restraints.
Tracings of respiration (inspiration down) and biceps EMG shows 3 stages in progression of the arousal response. The first panel shows a sigh alone. The second shows a sigh accompanied by a startle, and the third shows a sigh, startle, and full arousal.