Performance repeatability of fiberoptics applicators for laser therapy

The distribution of light emitted from the sol-gel coated fiberoptic applicator for interstitial laser therapy was examined. The silica sol-gel coatings were prepared from silicate precursor TEOS (tetraethylorthosilicate) mixed with ethyl alcohol in acid catalyzed hydrolysis. The applicator was produced with ratio R = 20, whereas R denotes the number of solvent moles (ethanol) to the number of TEOS moles. Then, the light pattern was captured by means of CCD camera and statistical pattern recognition method was applied to study the repeatability of light distribution. Two methods were applied: Fisher Linear Discriminant Analysis (FLDA) and Principal Component Analysis (PCA). The top match characteristic TM as calculated by statistical pattern recognition methods was taken as a factor corresponding to the performance repeatability. It was demonstrated that is possible to produce the sol-gel applicators with more than 92% repeatability.