Accuracy of Pulse Oximeters During Profound Hypoxia

This study is designed to calibrate and determine the accuracy for SpO2, pulse rate and respiratory rate of the newly in-house build Test Device wrist 1 (TDw1, or EVA) at Philips. SpO2, pulse rate and respiratory rate during hypoxia will be calculated by using data of well-known reference devices, including: * A reference SpO2 sensor of Nellcor placed at a fingertip, that reflects also continuously the pulse rate Will be used to compare with the test device. * A reference respiratory rate device that calculates the respiratory rate based on detection of end-tidal CO2 peaks by capnography. * Oxygen saturation in arterial blood samples (SaO2), determined by a co-oximeter will be used to calculate the accuracy of the test device. During the study the following devices will be additionally used by the volunteers: * AppleWatch 7 * TDw2, watch build by philips, using the PPG and software technology developed by Philips * A smartphone that detects reflected PPG signals from the reflected screen at the handpalm, by the build in frontfacing camera (TDc) of the smartphone Volunteers will undergo progressive hypoxia (9 min/% O2) from 21 to 10% O2 in an altitude room, resulting in a volunteer's SpO2 of 73%. During this deliberated hypoxia, the volunteers wear the test and reference devices. This study consists of 4 sub-studies (NI = non-invasive; IN = invasive with an arterial line): * NI (Fast-Sitting): volunteers are seated in the hypoxia room in which the ambient oxygen concentration decreases at a speed of 9 min/% O2. If the volunteer reached a SpO2 ≤73% for more than 1 minute, he/she leaves the hypoxia room. And will breath air with 21% oxygen. Volunteers wear TDw1 and TDw2 and the reference devices. * NI(Fast-Lying): identical to NI(Fast-Sitting) but volunteers lay on a mattress. Volunteers wear TDw1 and AppleWatch 7 and the reference devices. * NI (Slow-Sitting): identical to NI (Fast-Sitting), but after one of the volunteers reaches a SpO2 ≤73% for more than one