A prospective, multi-centre, single-arm, open-label, interventional study with a non-marketed medical device.

The primary study objective is to assess the efficacy of the keepMED PAP device on modification of respiratory characteristics in patients with OSA at one therapy night in a sleep lab.

Secondarily, the safety of the use of the device in this setting is assessed.

The study includes a baseline visit, a habituation night, and a therapy night. Both nights will be undertaken in the sleep lab under identical conditions and will include the keepMED PAP therapy activated in parallel to polysomnography (PSG).

Baseline diagnostic PSG, performed within one month prior to enrollment to the study, will be used to assess the device efficacy.

An interim analysis to re-estimate the sample size will be performed after availability of data of 50% enrolled and treated study patients. The sample size will be re-estimated based on the observed changes of AHI in the interim analysis.

Inclusion Criteria:

Age ≥18 years.

Newly diagnosed OSA with AHI ≥ 15 events/hours.

Indication for OSA PAP therapy in routine clinical care according to applicable medical guidelines within one month prior to study enrolment.

Naïve to PAP therapy, i.e. even no PAP therapy during a PSG night.

Weight > 30kg.

Signed informed consent.

Exclusion Criteria:

Body Mass Index (BMI) of ≤20 kg/m² or ≥ 35 kg/m².

Pathologically low blood pressure (systolic ≤90mm Hg; diastolic ≤60 mm Hg).

Current unstable or serious medical conditions (such as angina pectoris, myocardial infarction, cancer, stroke, dementia, congestive heart failure) which based on the physician's judgment might put the patient at high risk.

Mixed and central apnea index ≥ 5 events/hour in PSG without PAP therapy.

Bullous lung disease.

Tracheostomy.

Pneumothorax.

Pneumocephalus.

Cerebrospinal fluid leak.

Current sinus or middle ear infection.

Persistent blockage of one or both nostrils (including nasal septum deviation and nasal polyps) or any other reason that leads to difficulty of breathing through the nose while awake.

Any nasal, facial or head abnormalities that would not allow adequate placement of the device.

Previous diagnosis of insomnia, narcolepsy or periodic limb movement disorder that in the judgment of the clinician could affect sleep quality assessment.

Chronic respiratory disease (COPD, pulmonary fibrosis or asthma) or FEV/FVC ≤ 60% in history.

History of respiratory failure.

Supplemental oxygen is required.

Uvulopalatopharyngoplasty or other surgical procedure to correct apnea.

Acute respiratory infection.

Subject recovered from Covid-19 but suffers from on-going symptoms or when subject's Covid-19 illness history can affect the study outcome based on the physician's judgment.

Pregnancy.

Medication that may alter sleep architecture.