Performance evaluation of an implantable sensor for deep brain imaging: An analytical investigation

Imaging neural activities at the cellular level in the deep brain is essential to understand the structure and functions of nervous systems. Recently developed fully implantable optical sensors have the capability to capture fluorescence signals within the deep tissue; however, their potential for high-quality imaging is not clear. In this paper, we develop a simplified model to analytically study the photon transport in the biological tissue, and utilize it to understand the optical performance of an implantable fluorescence imager. Spatial resolution of the implanted imager is calculated, and imaging qualities for groups of neurons in two- and three-dimensional configurations are evaluated. The results here establish feasible solutions to design implantable optical sensors and predict their performance for biomedical applications.