Detecting in vivo changes of electrical properties of Cerebral Spinal Fluid using microwave signals from small coil antennas - numerical simulation

Dielectric properties of Cerebral Spinal Fluid (CSF) at microwave frequencies correlate with a higher level of glucose or protein observed at certain diseases, including early stages of Alzheimer´s disease. In this study, a simulation of in vivo monitoring dielectric properties of Cerebral Spinal Fluid (CSF) using small antennas precisely positioned around the human head is made. We use a realistic mesh model of the head and head organs obtained by fine segmentation of the Visible Human Project® data. An accurate source model with coincident phase centers is employed in the underlying Finite Difference Time-Domain (FDTD) algorithm. Simulation result strongly depends on the type and positioning of small antennas around the head, and on the mechanical accuracy. Once these factors are properly optimized, the changes in the relative dielectric constant on the order of 10-15% may be recorded using the phase shift of a second received pulse.