Emulation of Brain Metabolic Activities Based on a Dynamically Controllable Optical Phantom

This paper presents a dynamic optical phantom for the simulation of metabolic activities in the brain, and a linear equivalent model is built for control voltage versus substance concentration. A solid-solid dynamic optical phantom is realized by using liquid crystal film as a voltage-controlled light intensity regulator on the surface of basic phantom, which uses epoxy resin as matrix material and nanometer carbon powder and titanium dioxide powder as absorption and scattering dopants, respectively. The dynamic phantom could mimic near-infrared spectrum (NIRS) signals with sampling rate up to 10 Hz, and the maximum simulation errors for oxy-hemoglobin and deoxy-hemoglobin concentrations varying in the range of 1 mu mol/l are 7.0% and 17.9%, respectively. Compared with similar solid biomimetic phantoms, the adjustable mimic substance concentration range is extended by an order of magnitude, which meets the simulation requirements of most brain NIRS signals.