Surface Motion Tracking Hardware for use in Reflectance-based Diffuse Optical Imaging
The problem that is addressed in this thesis is the need to record the physical location of a contact based imaging probe and subsequent measurement, specifically for using diffuse optical spectroscopic imaging. A novel motion tracking system was developed using a combination of 3D scanned surface and embedded inertial/optical motion sensors. The motion tracking system was used in combination with a fast CW DOSI system to decrease single point measurement speed. The combination system was able to increase the spatial resolution of optical absorption measurements as compared to previous generation DOSI system. The motion tracking system was calibrated to quantify the repeatability of each sensor type as well as the projection onto the 3D surface. The displacement sensor had average percent errors of 1.203% and 1.552% over a flat surface at 50mm, 100mm respectively. The average percent error increased to 3.640% and 3.126% when repeated 50mm and 100mm displacement tests on human skin. The projection of motion paths on a flat optical phantom, exercise ball, and human lower leg was shown. The accuracy of unknown point estimation was shown with accuracy ranging from 21.9%-60%.