Decreasing the size of the reflectance confocal microscope so that it is more portable and
easier to maintain will make it more clinically useful. One way to decrease the size is to
switch from the usual raster scan to a sweep scan, or theta scan. The microscope is then
confocal in one direction, but not in the other. An illuminating line scans across the
target and the light is scattered back to a linear array sensor. A radar engineer would call
this a bi-static configuration. However, a theta scan will result in signal drop outs when
scanning skin. It is hypothesized that these drop outs occur because of the interaction of
the bi-static imaging configuration with the geometry and inhomogeneity of the index of
refraction in the skin. These properties cause the backscattered wave to end up in a
location that is not the same as that viewed by the receiver, leaving that data out of the
final image. Modeling the backscatter will help in understanding the interplay between
the light and the skin as well as guide the creation of optics that are appropriate for
getting the optimal image. A skin model including the melanin, mitochondria, and
nucleus coupled with the FDTD algorithm is used to simulate a propagating wave
entering the skin model and backscatter towards the receiver.
Research completed by Blair Simon in 2008. For more information, contact Charles DiMarzio.
This research project is part of the work at the Optical Science Laboratory of Chuck DiMarzio in the Department of Electrical and Computer Engineering at Northeastern University. For other projects see Optical Science Lab Research Page.