Assessing the Potential Effectiveness of Diffuse Reflectance Spectroscopy for Quantifying Neonatal Skin Properties using Tissue Phantoms

Diffuse reflectance spectroscopy (DRS) has previously been shown to be effective at analyzing the optical characteristics of a wide variety of biological tissues, including the skin. In addition to being sensitive to the amount of blood and its oxygenation, DRS can be used to extract bilirubin levels and assess jaundice, a common complication in newborn infants. To assess its potential for being utilized in applications involving neonatal skin, we evaluated the utility of DRS for extracting hemoglobin and bilirubin concentrations from tissue phantoms. Phantom sets were created by including a known amount of scattering and by varying known concentrations of absorbers - hemoglobin and bilirubin - after which 5 measurements were taken from each well using a spectrometer. After calculation of the spectral reflection, using the absorption spectra of a pure solution of each absorber as a baseline, the data was inserted into a lookup table (LUT)-based model. The concentration values obtained from the model were then compared to the actual concentration values for each phantom. To further optimize the LUT-based model, the effect of averaging the five spectra taken from each sample was investigated at different points in the analysis process to determine the most accurate method for extracting concentration values from the LUT-based model. Based on our findings, it was determined that the difference between the outputs from each method of averaging data was not statistically significant. We additionally found that our setup was only capable of extracting accurate bilirubin values when the concentration was high. On the other hand, phantoms with lower amounts of hemoglobin produced more accurate hemoglobin concentration measurements. This suggests that more research should be completed in the future involving an altered LUT-based model and tissue phantoms with similar concentration ranges of bilirubin and hemoglobin to determine potential error sources in this study