Arterial pulsation modulates the optical attenuation coefficient of skin
Photoplethysmographic (PPG) signals arise from the modulation of light reflectivity on the skin due to changes of physiological origin. Imaging plethysmography (iPPG) is a video-based PPG method that can remotely monitor vital signs in a non-invasive manner. iPPG signals result from skin reflectivity modulation. The origin of such reflectivity modulation is still a subject of debate. Here, we have used optical coherence tomography (OCT) imaging to find whether iPPG signals may result from skin optical properties being directly or indirectly modulated by arterial transmural pressure propagation. The light intensity across the tissue was modeled through a simple exponential decay (Beer–Lambert law) to analyze in vivo the modulation of the optical attenuation coefficient of the skin by arterial pulsation. The OCT transversal images were acquired from a forearm of three subjects in a pilot study. The results show that the optical attenuation coefficient of skin changes at the same frequency as the arterial pulsation due to transmural pressure propagation (local ballistographic effect), but we cannot discard the contribution of global ballistographic effects.
Citação
@online{c._tolentino2023,
author = {C. Tolentino , Dominguez and M. Bigatão , Martinelli and
Luciano , Bachmann and George C. , Cardoso},
title = {Arterial pulsation modulates the optical attenuation
coefficient of skin},
volume = {40},
number = {4},
date = {2023-04-01},
doi = {10.1364/JOSAA.482939},
langid = {pt-BR},
abstract = {Photoplethysmographic (PPG) signals arise from the
modulation of light reflectivity on the skin due to changes of
physiological origin. Imaging plethysmography (iPPG) is a
video-based PPG method that can remotely monitor vital signs in a
non-invasive manner. iPPG signals result from skin reflectivity
modulation. The origin of such reflectivity modulation is still a
subject of debate. Here, we have used optical coherence tomography
(OCT) imaging to find whether iPPG signals may result from skin
optical properties being directly or indirectly modulated by
arterial transmural pressure propagation. The light intensity across
the tissue was modeled through a simple exponential decay
(Beer–Lambert law) to analyze in vivo the modulation of the optical
attenuation coefficient of the skin by arterial pulsation. The OCT
transversal images were acquired from a forearm of three subjects in
a pilot study. The results show that the optical attenuation
coefficient of skin changes at the same frequency as the arterial
pulsation due to transmural pressure propagation (local
ballistographic effect), but we cannot discard the contribution of
global ballistographic effects.}
}