TITLE:
Effect of Skin Pigmentation on Near Infrared Spectroscopy
AUTHORS:
Luke Couch, Mellisa Roskosky, Brett A. Freedman, Michael S. Shuler
KEYWORDS:
Near Infrared Spectroscopy, Skin Chromophores, Confounding Factors, Variability between Manufacturers
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.6 No.12,
November
2,
2015
ABSTRACT: The purpose of this study was to determine the
effects of skin pigmentation regarding Near Infrared Spectroscopy (NIRS) tissue
oxygen saturation values (StO2). The study examined NIRS values in
individuals with varying skin pigmentation on the anterior compartment of the
lower leg and volar forearm to determine if correlation exists among three NIRS
devices, the EQUANOX, Casmed, and INVOS. Skin pigmentation was measured on the
anterior lower leg (AL) and volar forearm (VF) of participants using a noninvasive
colorimeter that employed reflective spectroscopy to produce a quantitative
value for erythema (skin “redness”) and melanin (skin pigment). Muscle oxygenation
was measured using three oximetry devices with sensors placed in the same
areas. The EQUANOX device showed no significant correlation with skin
pigmentation, while the Casmed and INVOS devices showed moderate and
significant correlation with skin pigmentation, respectively. Different devices
have different abilities to remove confounding variables, such as skin pigmentation
and erythema, which may affect clinical decision-making, and affect the use of
NIRS technology.