During Visit 2, participants will first undergo a repeat optimal EPAP determination and then trial 3 different sessions of High Frequency Oscillation (HFO) therapy for 20 minutes with at least a 10 minute wash out period between each session to allow the participant's CO2 to stabilize or return to baseline. The order of the sessions will be randomized for each patient. Participants will be placed in a semi-recumbent position and wear a nasal CPAP mask for each session. A TcCO2 monitor patch will be placed on the skin (forehead area) to collect carbon dioxide measurements during each session. A RespiTrace belt will placed on the participants' chest wall to measure chest wall and diaphragmatic excursion during each session. A 3 lead EKG will also be used to monitor cardiac activity during each session.