Measuring Arterial Oxygen Saturation Using Wearable Devices Under Varying Conditions

Area of Science:

• Aerospace Medicine
• Biomedical Engineering
• Wearable Technology

Background:

• Wearable devices offer potential for monitoring arterial oxygen saturation (SpO2) in aerospace.
• Current use in aviation is limited as performance under flight conditions like hypoxia and motion is not established.

Purpose of the Study:

• To evaluate the performance of consumer-grade wearable SpO2 devices in simulated aerospace environments.
• To compare wearable device accuracy against a standard pulse oximeter under varying oxygen and motion conditions.

Main Methods:

• Ten healthy subjects were tested in a normobaric chamber simulating 15,000 ft altitude (11.8% oxygen).
• SpO2 was measured using a standard pulse oximeter and four wearables (Apple Watch S6, Garmin Fenix 6, Cosinuss Two, Oxitone 1000M).
• Measurements were taken at rest, during very slight, and moderate body motion (cycling at 30W and 150W).

Main Results:

• All wearable devices frequently missed SpO2 readings, with missed rates increasing with body motion (12-92%).
• Performance degraded under reduced oxygen conditions.
• Devices showed a tendency to either under-report or over-report SpO2 compared to the standard device.

Conclusions:

• The evaluated wearable SpO2 devices did not meet the performance standards of traditional pulse oximeters in simulated flight conditions.
• Limitations in accuracy and reliability may restrict their current utility in aerospace operations.
• Further investigation is required to address the identified performance gaps.