The aim of the study is to compare the measurement of peripheral blood oxygen saturation using a smartwatch with a medical-grade pulse oximeter.

Recently, wearables, like smartwatches, have been gaining new possibilities in monitoring biological signals and they are used for home monitoring of health conditions. The newest models of smartwatches even measure peripheral blood oxygen saturation (SpO2). The study aims to compare the measurement of peripheral blood oxygen saturation using the latest smartwatch with a medical-grade pulse oximeter under the condition of normobaric hypoxia. Healthy participants will breathe oxygen-reduced mixtures (the hypoxic gas mixture of 12% O2 and 88% N2 and the hypercapnic and hypoxic gas mixture of 12% O2, 5% CO2, and 83% N2), which will temporarily reduce their blood oxygen saturation. SpO2 measurements will be taken by hand from the watch and the pulse oximeter simultaneously. The agreement of the measurements of both devices will be evaluated.

Inclusion Criteria:

• healthy volunteers from the Czech Technical University

Exclusion Criteria:

• pregnancy
• severe cardiovascular conditions
• severe asthma or other severe respiratory conditions
• injury to the upper limbs or hands that could affect the peripheral perfusion
• diabetes
• hypotension or hypertension