Chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS) are respiratory conditions that disrupt normal breathing. Positive airway pressure, specifically Non-Invasive Ventilation (NIV) delivers positive pressures via an interface such as a face mask and has been shown to improve breathing and reduce symptoms in patients with these conditions. Regular use of NIV can lead to better symptom management, improved quality of life, and reduced use of healthcare resources. However, poor performance of the NIV mask and poor comfort can make NIV therapy harder to tolerate. This study will assess if a new mask helps to improve the breathing of people on NIV and normalize blood gases.

Participants are moved to the sleep laboratory for the night where they are provided with beds.

• The participants are put on their prescribed airway pressure support with the first randomized mask.
• After at least 60 minutes of recording, participants are awakened to switch back to the second mask. They are then allowed to sleep uninterrupted for the rest of the night.

Inclusion Criteria:

• Age over 18 years
• Prescribed nocturnal NIV for COPD or OHS
• Able to complete an overnight sleep study
• Comfortable to sleep on a standard double bed
• Capacity to complete informed consent

Exclusion Criteria:

• Uncontrolled sleep apnea (Apnea-hypopnea index (AHI) over 15 events/hour off personal NIV device data)
• Prescribed IPAP above 25 cmH2O
• Allergic to adhesive of the sensors
• Self-reported cold/flu symptoms