Optical Transcutaneous Sensors of Capnia and Oxygenation

Inclusion Criteria: * Males or females between 18 and 50 year old * Individual having health insurance * Individual able to provided informed consent * Subjects with no known pathology and not taking any medical treatment a priori capable of interfering with controlled hypoxia at levels required in the protocol Exclusion Criteria: * Body mass index \>27 kg/m² * History of acute mountain sickness * Chronic diseases know to be associated with high methemoglobinemia * Known allergy to one of the materials used in the devices (lycra, polyamide...), or to the adhesive plaster. * Active smoker (\>3 cigarets/day) * Alcohol consumption (\>10g/day) * Individual with high skin sensitivity due to skin diseases * Mental disorders * Persons who refuse to sign the information sheet and participation agreement * Persons under guardianship or not subject to a social security system * Pregnant woman, parturient, breastfeeding mother * Person deprived of liberty by judicial or administrative decision * A person who is subject to a legal protection measure that cannot be included in clinical trials.