Skin optical attenuation coefficient modulation with arterial pulsation

TL;DR

This study demonstrates that skin optical properties, specifically the attenuation coefficient, are modulated by arterial pulsation, providing insights into the physiological basis of video plethysmography signals for noninvasive vital sign monitoring.

Contribution

The paper reveals that skin optical attenuation varies with arterial pulsation, confirmed through OCT imaging, linking optical properties to physiological arterial pressure changes.

Findings

Attenuation coefficient of skin changes with arterial pulsation

OCT imaging confirms modulation of skin optical properties by arterial pressure

Supports use of vPPG for noninvasive vital sign monitoring

Abstract

Video plethysmographic (vPPG) signals arise from subtle color modulations in reflected light. vPPG signals can be used to monitor vital signs remotely in a noninvasive manner. We have used optical coherence tomography (OCT) imaging to find whether vPPG signals may result from skin optical properties being modulated by arterial transmural pressure propagation. Our results confirm this hypothesis and show that the attenuation coefficient of even the most external, non-vascularized skin, changes at the same frequency as the arterial pulsation.