Contactless SpO₂ with an RGB camera: experimental proof of calibrated SpO₂

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Physiological Monitoring

Background:

• Camera-based blood oxygen saturation (SpO2) monitoring offers non-contact, safe, and efficient measurements.
• Existing technology faces challenges with hardware, particularly cameras capturing optimal wavelengths, and accuracy issues with standard RGB cameras.

Purpose of the Study:

• To develop and validate a low-cost camera-based system for accurate SpO2 monitoring.
• To mitigate risks associated with RGB cameras and improve measurement accuracy.

Main Methods:

• Utilized low-cost commercial off-the-shelf (COTS) components with a regular RGB camera.
• Conducted two studies: one in a hypoxia lab for calibration (SpO2 70-100%) and another on volunteers for accuracy in spot-check scenarios.
• Implemented a processing pipeline including face tracking and robust photoplethysmographic waveform analysis.

Main Results:

• The developed system demonstrated an error smaller than 4 percentage points in realistic screening conditions.
• Accuracy was maintained for seated subjects, with or without head support and in ambient light.

Conclusions:

• The proposed camera-based SpO2 monitoring system, enhanced with COTS components, provides accurate and reliable measurements.
• This non-contact approach is suitable for clinical screening, addressing cross-infection risks and improving workflow efficiency.