Developing and testing a multi-source and detector reflectance diffuse optical tomography system


SPIE Photonics West, San-Francisco, United States Of America, 1 - 06 February 2014, pp.216

  • Publication Type: Conference Paper / Summary Text
  • City: San-Francisco
  • Country: United States Of America
  • Page Numbers: pp.216
  • Akdeniz University Affiliated: Yes


A continues wave reflectance diffuse optical tomography (rDOT) system with an optical fiber probe, including 49 sources and 49 detectors has been developed and tested using breast tissue phantoms with inclusions.Allthe source and detector fibers are located on a 10 × 10 grids with dimensions of 28mm × 28mm, and the source and detector fibers are separated bythree mm. In total, there are 22 different source-detector distances on the probe.The system has a high dynamic range due to the six different integration times for each detector channel. A calibration method has been developed to calibrate multi source and detector fiber probe. Data acquired from ahomogenous tissue phantom was a mixture of 1% intralipid and indocyanine green (ICG) with a reduced scattering (ms) and an absorption (ma)coefficients of 1 mm−1 and 0.02 mm−1, respectively. The inclusions were prepared using the intralipid and ICG mixture to have scattering and absorption coefficients of 1 mm−1 and 0.073 mm−1, respectively. The tip of the probe was placed on the surface of the tissue phantom, and the inclusion was placed at depths of 5, 10, 15, and 20 mm in the intralipid mixture then the data were acquired.For the reconstruction, the perturbation data were obtained in two different ways. The first was by direct subtraction:the measurements of the tissue phantom acquired without the inclusion were subtracted from those with the inclusion. In the second method, an average over the measurements with the same s-d separation was calculated, and this was then subtracted from the original measurements and repeated for all s-d separations. The tissue phantoms were reconstructed using Tikhonov regularization. The depth compensation algorithm (DCA)was used to increase the accuracy of the localization of the inclusions at different depths.