Study Overview The goal of this clinical trial is to learn whether an improved non invasive ventilation mask with airway washout can reduce how often people need to breathe and perform as well as standard NIV masks when used with different ventilators, in people receiving NIV therapy for respiratory distress or respiratory insufficiency.

The main question(s) it aims to answer are:

• Does the new mask reduce breathing rate compared with a standard NIV mask?
• Does the ventilator perform as expected when used with the new mask, including pressure delivery and leak?
• Do clinicians and participants find the new mask fits and functions well?

Three iterations of the new mask (vented, non-vented, dual limb) will be compared to standard of care to see if the mask reduces the need to breathe and performs consistently across ventilators compared with usual NIV masks.

________________________________________ What Participants Will Do Participants will wear two different NIV masks, each for one hour, during a single study session lasting approximately 2.5 hours.

Participants will be asked to:

• Wear a small, stick on carbon dioxide (CO₂) sensor on the skin.
• Use their usual NIV mask for one hour while ventilator data are collected.
• Switch to the investigational mask for one hour while ventilator data are collected.
• Choose whether to return to their original mask or remain on the investigational mask after the study period.
• Caregiver opinion on the mask will be collected.

Participants may also choose (optional):

• To have three small blood samples taken (These samples are optional, and participants can still take part in the study if they decline them.)

  • One when they agree to take part in the study
  • One when the investigational mask is fitted
  • One after wearing the investigational mask for one hour

• To provide feedback on how the two masks felt and performed.

During the study, researchers will collect data from the ventilator, including:

• Breathing rate and depth
• NIV pressure settings
• Amount of air leak Research staff will also complete a short form assessing how well the mask fit and functioned. Participants will remain in the study until the investigational mask is removed.

The investigational masks perform as the commercially available comparators delivering the prescibed NIV, with the potential benefit of upper airway and instrumental dead space washout. This should improve RR by approximately 3 BPM. This study is to establish the investigation mask has similar usability as the comparator with improved efficacy, potentially reducing RR. The knowledge gained during this clinical investigation may provide further clinical benefits to patients with respiratory failure.

Non-invasive ventilation (NIV) is a method of delivering respiratory support without using an endotracheal tube. It's a first-line treatment for specific conditions like COPD exacerbations and acute cardiogenic pulmonary edema. NIV aims to improve gas exchange, reduce work of breathing, avoid intubation, and reduce complications.

For patients with COPD exacerbations and acute cardiogenic pulmonary edema NIV is a first line therapy. NIV is also considered for other conditions like acute respiratory failure due to asthma exacerbation and in immunocompromised individuals with acute respiratory insufficiency. Additionally, it can be used in post-operative respiratory failure, for difficult weaning, and to prevent post-extubation failure.

NIV has been shown to result in overall better outcomes than mechanical ventilation with reduced mortality and morbidity, fewer ICU acquired infections improved lung function and shorter ICU stays. The severity of the respiratory insufficiency influences the likelihood of successful NIV. One factor associated with respiratory sufficiency is respiratory dead space. This is the volume in the respiratory apparatus that does not partake in gas exchange and in the ventilated patient includes the volume in the equipment, the conductive airways and pathological respiratory tissue. A high dead-space fraction early in the course of the illness is association with increased risk of death.9 Particularly in patients that have a small tidal volume and high respiratory rate, or patients with an increased physiological dead space due to lung disease, a change in instrumental dead space can have a large impact on alveolar minute ventilation. Improved alveolar ventilation can improve CO2 elimination and help to reduce respiratory acidosis as well as improve oxygen delivery.10, 11 This can consequently reduce the respiratory effort required by the patient. 12 If the physician instead chooses to keep arterial CO2 concentration (PaCO2) constant, a reduction of instrumental dead space will allow a reduction of tidal volume, plateau pressure, driving pressure, or a reduction of the respiratory rate and thus a reduction in work of breathing.

NIV with washout improves ventilation compared to conventional NIV by reducing expired air in each breath. This may result in faster normalization of ventilatory gases and a reduced work of breathing, the patient may improve more rapidly as alveolar ventilation is improved. Or, allow for a reduction in pressure for similar ventilatory benefits, potentially improving NIV tolerance and therapy adherence. In stable COPD patients, NIV with Airway Washout resulted in a significant reduction in minute ventilation compared to conventional NIV. This was approximately 19% lower with OptiNIV compared to conventional NIV.15 In this study minute ventilation will be calculated from the RR and Vt retrieved from the ventilator to asses improvement in ventilation over the study period, this self-control study aims to establish efficacy of airway washout and whether the generation 2 design changes do not impact usability. When airway washout becomes more widely available it may improve NIV therapy efficacy by improving ventilation or reducing the pressure needed for a similar level of ventilatory support.

Inclusion Criteria:

• Adults that are stable on prescribed NIV
• Able to receive NIV therapy on a sub-nasal mask
• Are 21 years old or older

Exclusion Criteria:

• Contraindicated for NIV
• NIV is likely to fail and/or intubation be required, at the doctor's discretion
• CPAP or bilevel pressure of ≥ 30 cmH2O required
• Do not fit the investigation mask or the standard mask
• Pregnancy (tested under standard care)
• Unable to tolerate NIV for the duration of the investigation
• Unable to understand the consent process

due to the nature of the study it is not possible to blind the investigator or the participant to the mask type, they look different. The objective ventilatory parameters will be assessed blindly.