Patients with chronic obstructive pulmonary disease (COPD) can eventually progress to respiratory failure, where they cannot adequately exchange oxygen and carbon dioxide, leading to worsening breathlessness, frequent hospitalisations and death. Non-invasive ventilation (NIV) is a ventilator therapy that is used in COPD patients who suffer from respiratory failure. Studies have demonstrated that using NIV at night regularly can result in improved clinical outcomes.

Adherence to this therapy is variable, however. This can be due to poor synchrony between the device and the lungs. A novel ventilator has been designed that delivers NIV but is also incorporated with technology to assess for aberrations in respiratory physiology and correct them, breath-by-breath.

The investigators aim to assess the efficacy, safety and tolerability of this novel ventilator. The primary research question is whether the novel ventilator can improve adherence to therapy, when compared with the usual ventilator.

Patients with COPD who use ventilation at home will be screened for inclusion in the study. Participation will involve a screening visit, and a further two visits to the Lane Fox Respiratory Unit. The first will require a two-night admission and the second a single-night admission. They will undergo detailed assessment of their daytime and overnight respiratory and sleep physiology during these admissions. These visits will be separated by a six-week period during which they will be asked to use the novel ventilator at home.

Patients will be recruited into a sub-study to evaluate the performance of the ventilator in a daytime physiological assessment. This will involve detailed invasive physiological assessment of expiratory flow limitation and how the machine is able to adjust settings to optimise respiratory support.

Patient Inclusion Criteria:

• Age ≥ 18 years
• BMI <30 kg/m¬2
• Confirmed diagnosis of COPD
• Currently using domiciliary NIV with average reported compliance of at least 3hours
• Ability to provide informed consent
• Medical stability confirmed by recruiting physician
• Free of exacerbations for at least 2 weeks prior to enrolment
• Presence of expiratory flow limitation on forced oscillation technique criteria

Exclusion Criteria:

• Current acute illness as determined by recruiting physician e.g. upper respiratory tract infection
• Presence of major medical comorbidity, e.g. severe heart failure (LVEF <30%), active malignancy, end-stage renal failure (CKD 4), and neuromuscular disease
• Subjects who have had surgery of the upper airway, nose, sinus, or middle ear within the previous 90 days.
• Psychosocial factors that would prevent compliance with study protocol

Healthy participant inclusion criteria:

• Age ≥ 18 years
• No expiratory flow limitation on forced oscillation testing
• No acute illness on study day
• Ability to provide informed consent