Inclusion Criteria:  Patients less than 17 years of age admitted to the Duke Children's PICU or PCICU with acute respiratory failure due to a pulmonary illness will be considered eligible for the study  Exclusion Criteria:  Patients with corrected gestational age less than 37 weeks Patients with contraindications to the ENLIGHT device (i.e. temporary or permanent pacemaker, vagal nerve stimulator, automatic implanted defibrillator, chest tubes that interfere with electrode belt placement, open chest wounds, unstable thorax, severe chest wall deformities) known pregnancy Patients previously enrolled in this study will be excluded from participation.