This research study is being done to investigate the effect of changing an infant's body position on how hard the baby works to breathe, the baby's oxygen level, the baby's carbon dioxide level, the baby's lung volume, the baby's lung compliance (ability of the lung to expand and fill with air), and how frequently the baby develops clinically significant events such as apnea (baby stops breathing on his own), bradycardia (low heart rate), and desaturation (low oxygen) events.

Inclusion Criteria:

• Viable infants born at ≤32 weeks of gestation on non-invasive NAVA.
• Infant must be stable on NAVA for at least 24 hours prior to the study

Exclusion Criteria:

• Infants with congenital heart disease (CHD)
• Infants with persistent pulmonary hypertension (PPHN)
• Infants with contraindications to using NAVA (e.g. neuromuscular blockage or paralysis, absent electrical signal from the diaphragm, esophageal tears or bleeding, cardiac pacemakers) or infants in whom an NG/OG catheter cannot be placed.