Endoscope-based scattering measurements of esophagus phantoms

In today's medical world, endoscopy is one of the most common methods for assessing a patient's health status, yet in most cases, endoscopy is not sufficient and usually requires other examinations as well. It is widely known that healthy, and diseased tissues possess different optical properties like scattering and absorption. By finding the changes in those optical properties it's possible to determine the tissue status by endoscopy only. This poster suggests an alternative self-calibrated endoscopy examination for finding these properties and quantitatively assessing the tissue. Implementing the physical phenomenon called the iso pathlength (IPL) point, makes it possible to extract the tissue absorption property since it simplifies the problem into an easily solvable first-order problem. The phenomenon claims the existence of physical positions on the surface tissue, in which the light reflected from, isn't affected by the tissue's scattering. The work proves experimentally the existence of the IPL point for hollow cylindrical tissue structures. Three hollow cylindrical phantoms, with different scattering coefficients and negligible absorption properties, were illuminated, and by extracting all the reflected intensities of the different phantoms as a function of length or angle, a cross point between all the variables was shown. This spot proves the existence of points that aren't affected by the scattering profile.