Date of Award

August 2020

Degree Type


Degree Name

Doctor of Philosophy (PhD)




Joseph Chaiken

Subject Categories

Physical Sciences and Mathematics


The overall aim is to advance the use of light for noninvasive monitoring of living systems generally defined. We first describe work used to test a methodology for real-time probing of chemical and physical changes in spinal cords in the immediate aftermath of a localized contusive injury by way of calculating pH to monitor physiological changes in the system. Utilizing a previously developed unique algorithm, line scans of injured cords as well as optical profilimetry and scanning NIR autofluorescence images were obtained simultaneously in vivo, on exposed rat spinal cords. For line scans, the laser spatially scanned across the cord or, to collect Raman spectra, held at a specified location relative to the injury. Line scans reveal photobleaching effects and surface and shallow subsurface profiles, possibly locating cord vasculature. Analysis of the in vivo Raman spectra reveals phosphate features allowing calculation of cerebrospinal fluid pH. We developed additional technology to allow in vivo measurement of cell culture viability as e.g. glucose uptake rate, in real time. Proof of principal was demonstrated by physically sampling medium of viable cultures over time. That success motivated an attempt to repeat the measurement on the medium inside the culture flask without physical sampling. The final part of my research focused on observing the effects of x-ray irradiation on bone. Differences between control bones, irradiated bones, and the contra-lateral limb of the irradiated bones were assessed using depolarization ratios and other Raman spectral markers to assess internal effects of the radiation on protein and fat metabolism in bone.


Open Access