Reflectance spectroscopy system for noninvasive prediction of skin bilirubin concentration related parameter

Bilirubin level increased when one's liver is unable to remove bilirubin sufficiently from the blood. The conventional methods used for monitoring and measuring the bilirubin level are tedious, time consuming and may be invasive in nature. This research employed reflectance optical system to collect spectroscopic data of light reflected from skin. Modified Lambert Beer model is used to predict one's skin bilirubin level using a priori information of bilirubin absorptivity in the wavelength range of 440-490 nm. This study found a lower skin bilirubin level of 1.0043 ± 0.02 AU (arbitrary unit) amongst the renal disease volunteers compared to 1.0165 ± 0.0197 AU for healthy volunteers. Meanwhile, no significant changes in the value were observed for populations with different skin color. The absolute difference in the mean and standard deviation of these values was calculated as 0.005 ± 0.03 AU. This preliminary study concluded that the developed system and strategy may be used as an alternative means to assess one's skin bilirubin level and hence a diagnostic tool for clinical application such as renal disease, jaundice and hepatitis.