Minimally invasive localization of light source in tissue with an equidistant measurement

Bioluminescence techniques permit a way of observing biological processes in vivo, and they are considered to have a promising application on guiding tumor resection. But now, the related techniques, like bioluminescent imaging and bioluminescent tomography, have a common problem on imaging depth limitation. In this paper, a minimally invasive method was introduced to detect the emission of light source beneath the deep tissue. An equidistant measurement that derived from the diffusion equation and spherical light source model was proposed to localize the light source. Using this method, we obtained the analytic solution for 3D position of light source allowing the insertion penetrating the center of light source and unknowing parameters of the tissue. In the end, we put forward a feasible design of minimally invasive probe for clinic use.