Glucose sensing in aqueous Intralipid™ suspension with an optical coherence tomography system: Experiment and Monte Carlo simulation

Peculiarities of light transport in Intralipid™ solutions and the effect of glucose on light scattering properties of the solution at two different Intralipid™ concentrations were studied with optical coherence tomography (OCT) technique in vitro. An open air OCT system using a superluminescent light source with λ_center = 830 nm was used. 5% Intralipid™ solutions were used to simulate a biological tissue (skin) in our experiment. Glucose concentrations at the physiologically relevant level were added to Intralipid™ solutions. Increasing Intralipid™ concentration increases the scattering coefficient of the media meanwhile increasing glucose concentration increases the refractive index of the media and reduces the scattering coefficient of the media. The experimental data were compared to Monte Carlo simulations. We also made the simulations for 2% Intralipid™ solution. The results indicate that glucose added to 2 and 5% Intralipid™ solutions changes their scattering properties, which is manifested by a decrease in the slope of the OCT signal. This finding shows the ways of using OCT for sensing glucose and monitoring the alterations of its content in biotissues. Some discrepancies between measurements and simulations were found, which need former investigation.