The aim of the study is to compare the accuracy of peripheral blood oxygen saturation measurements using smartwatches from three manufacturers compared to a standard medical pulse oximeter.

The aim is to create a study that compares multiple smartwatch models simultaneously with a standard medical pulse oximeter using a single measurement methodology. According to the available literature, no such study exists. The methodology of the study and the subsequent statistical evaluation are based on the guidelines of the standard ČSN EN ISO 80601-2-61, which specifies requirements for the basic safety and necessary functionality of pulse oximetry devices. The comparison will be performed non-invasively in healthy volunteers during gradual desaturation in the range of 70-100 % SpO2 (normobaric hypoxia). The data obtained could help to increase the awareness of the possibilities of SpO2 monitoring using smartwatches in medical conditions that are manifested by a decrease in SpO2 level over a longer time period, where measurement with a conventional oximeter is impractical.

Inclusion Criteria:

• Passing the initial examination, which will determine the following data: wrist circumference, heart rate, blood pressure and blood oxygen saturation

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