Emerging Technology for Noninvasively Measuring Oxygen Saturations

Area of Science:

• Biomedical Engineering
• Medical Diagnostics
• Optical Physics

Background:

• Blood oxygen saturation (SpO2) and tissue oxygenation (StO2) are vital clinical measurements.
• Arterial blood gas analysis is the gold standard for SpO2 but is invasive and resource-intensive.
• Current noninvasive methods for SpO2 and StO2 lack universal acceptance and have limitations.

Purpose of the Study:

• To review current and emerging technologies for noninvasive SpO2 and StO2 measurement.
• To identify limitations of existing methods and potential areas for technological advancement.
• To highlight the promise of optics-based technologies for oxygen monitoring.

Main Methods:

• Review of currently marketed oximeters utilizing red/infrared light spectra.
• Exploration of alternative optical approaches including white light, AI, and camera-based image analysis.
• Examination of chemical, optical, and nuclear-magnetic principles for StO2 measurement.
• Assessment of emerging green light technologies for oxygen monitoring.

Main Results:

• Optics-based technologies are most promising for noninvasive SpO2 and StO2.
• Existing methods primarily use red/infrared light, with emerging use of white and green light.
• StO2 measurement techniques are often confined to specific clinical applications.
• Melanin in skin tone interferes with optical measurements of oxygen saturation.

Conclusions:

• Optics-based methods, including red-infrared and blue-green light, are the most viable for noninvasive oxygen monitoring.
• A significant limitation is the confounding effect of skin melanin on light absorption.
• Enhancing accuracy requires incorporating correction factors for melanin absorption in optical measurements.