Comparison of SpO2 Measurement Accuracy of Different Types of Smartwatches (CSMADTS)

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.

All participants go through all study arms, in random order. Two measuring devices are active simultaneously during each measurement on each participant and their functioning is compared.

Volunteers sequentially inhale three hypoxic gas mixtures each for 2.5 minute. Every measurement will begin with a two-minute stabilization phase, during which the physiological values of the volunteer will be checked. During the experiment, SpO2 measurements will be taken by hand from the watch and the pulse oximeter simultaneously.

Volunteers sequentially inhale three hypoxic gas mixtures each for 2.5 minute. Every measurement will begin with a two-minute stabilization phase, during which the physiological values of the volunteer will be checked. During the experiment, SpO2 measurements will be taken by hand from the watch and the pulse oximeter simultaneously.

Volunteers sequentially inhale three hypoxic gas mixtures each for 2.5 minute. Every measurement will begin with a two-minute stabilization phase, during which the physiological values of the volunteer will be checked. During the experiment, SpO2 measurements will be taken by hand from the watch and the pulse oximeter simultaneously.

Breathing mixtures of O2 (14 %, 12 %, 10 %) balanced with N2 and monitoring SpO2 by one of the smartwatch models on left wrist and by pulse oximeter on left index finger.

The agreement of SpO2 measurements of every model of smartwatches and reference pulse oximeter will be evaluated

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

Rafl J, Bachman TE, Rafl-Huttova V, Walzel S, Rozanek M. Commercial smartwatch with pulse oximeter detects short-time hypoxemia as well as standard medical-grade device: Validation study. Digit Health. 2022 Oct 11;8:20552076221132127. doi: 10.1177/20552076221132127. eCollection 2022 Jan-Dec.