Monte Carlo modeling and phantom study for implantable fluorescent analyte sensors for human head

Abstract

The overall goal for this project is the development and study of a quantitative fluorescence sensor for <i>in vivo</i> detection of β-amyloid (Aβ), the primary protein component of senile plaques in Alzheimer's disease (AD). Toward achieving that goal a Monte Carlo simulation has been developed to model photon propagation through the human head and a phantom model of the human head has been built and tested. In both cases a four layer model that included the skin, skull, fluorescent biosensor, and gray matter was used. A sensitivity study was performed to investigate the influence on the fluorescent output intensity of changes in concentration of the sensor. The results show that the fluorescent output intensity is detectable with a reasonable fluorescent sensor concentration and increases nearly linearly with increases in fluorescent concentration in the sensor. These results imply that the sensor would be detectable through the head using a reasonable optical system. The overall results are being used to aid in the design of the fluorescent sensor and the optical system for early detection of AD.