Validation of a Miniature SpO2 Sensor in Healthy Subjects and Patients With Long-term Oxygen Therapy.

Healthy volunteers Inclusion Criteria: * Age 18 - 60 years, * Non smoker, * Good general health and physical fitness * Informed Consent Exclusion Criteria: * Current or history of tobacco smoking (\> 5 py) * Current alcohol or drug abuse * Heart disease or untreated arterial hypertension * Pulmonary disease * Epilepsy or other major neurologic disease * Dark skin colour * Known anemia * Severe metabolic disease (e.g. diabetes) * Pregnancy Patients Inclusion Criteria: * Age ≥ 18 years * Long term oxygen therapy at rest and/or on physical effort * Hypoxemia in arterial blood gas analysis at rest PaO2 ≤ 55 mmHg or \< 60 mmHg with PHT or polycythemia (men Hb \> 174 g/L, women Hb \> 140 g/L) or: Oxygen desaturation on effort (SpO2 \< 90%) * Pulmonary disease including Chronic Obstructive Pulmonary Disease, Interstitial Lung Disease and Sarcoidosis * Informed Consent Exclusion Criteria: * Severe hypoxemia (pO2 \<40 mmHg) * Severe hypercapnia (pCO2 \>55 mmHg) * Acute respiratory infection or systemic infection, * Severe systolic heart disease (LVEF \< 25%) * Myocardial infarction during the last month before inclusion * Unstable angina pectoris * Severe aortic stenosis (mean gradient \> 40mmHg, valve area \<1 cm2) * Rhythmogenic heart disease * Severe or untreated arterial hypertension (blood pressure \> 180mmHg systolic, \>100mmHg diastolic) * Anemia (Hb \< 120 g/l) * Known or suspected coagulation disorder (e.g. INR \> 4) * Severe or untreated metabolic disorder * Neurologic disease or dementia * Pregnancy * History of non-compliance to medical treatment * Current alcohol, drug abuse or current tobacco smoking * Dark skin color