How Skin Color Depends on Tissue Oxygenation

Area of Science:

• Physiological Optics
• Biomedical Engineering
• Dermatology

Background:

• Skin color provides critical insights into skin physiology and pathology.
• Understanding skin color mechanisms can expand the applications of remote photoplethysmography (rPPG).

Purpose of the Study:

• To develop a straightforward analytical framework connecting skin color to blood oxygenation and perfusion.
• To establish a quantitative link between physiological parameters and observable skin color variations.

Main Methods:

• A two-part model was developed.
• The core model relates changes in tissue chromophore concentrations to alterations in tissue reflectance.
• Tissue reflectance was further convolved with sensor response curves and light source spectra.

Main Results:

• The model successfully links variations in blood oxygenation and perfusion to changes in skin color.
• Demonstrated the ability to quantify the impact of physiological changes on skin optical properties.

Conclusions:

• The developed model aids in interpreting the amplitude components of rPPG signals.
• Provides a foundation for more accurate non-invasive physiological monitoring using skin color analysis.