Beveled Fiber Probe for Improving Spectroscopic Signal Sensing from Bowel Mucosa Tissue.

The goal of this work is to devise an optical fiber probe configuration for fiber fluorescence spectroscopy to improve its diagnostic capability in gastrointestinal (GI) cancers. Proposed design upgrades to the probe's distal tip showed a major increase in spectroscopic signal sensing compared to standard probes, indicating that the accuracy of the method may be improved significantly. GI cancers are globally common and mostly seen in the colon, stomach, and esophagus, where current diagnosis is made using endoscopy and histopathology. However, endoscopy cannot visualize early signs of cancer, while histopathology requires a biopsy and takes several weeks to conclude. Fiber spectroscopy may provide rapid and robust diagnostics at early stages in vivo or ex vivo and may be able to guide clinical decisions to further curtail the risk of advancing to later stages of cancer. However, its medical diagnostic performance has not reached the gold standard level yet and, thus, needs to be studied further to improve its accuracy. Therefore, we demonstrate the application of a beveled probe tip and specific fiber positioning in a combinatorial approach and experimentally compare the design with several standard probes to assess their efficiencies. Results show that the proposed probe is notably more efficient in collecting fluorescent signals from excised small human colon tissues. Findings of the current study may help in implementing an alternative rapid path for histopathological standardization ex vivo for unambiguous decision making and may enhance the precision of endoscope-adapted in vivo fiber spectroscopy to provide real-time and noninvasive early diagnosis in GI cancers.