The method of Partial Least Squares (PLS) is applied to Raman spectra acquired from tissue phantoms. The objectives of this project have direct pertinence the concerns of physicians and patients about silicone implant integrity. To date, about 2 million women have received silicone-containing implants. Thus, a means for non-invasive determination of implants integrity continues to be a goal of the medical community. The potential sensitivity of optical detection could aid in early detection of leaks.
While methods for quantification of particular components of optically dilute samples are well known, these cannot typically be directly applied to tissue-like systems. The effects of scattering and absorption typically superimpose nonlinearly, making spectral interpretation difficult without sophisticated analytical techniques. Preliminary research in fluorescence and FT-IR spectroscopy indicates that the method of PLS accurately predicts concentrations in tissue-like systems. An attractive feature of this method is that it requires very little a priori information about sample composition. PLS has be used to accurately determine silicone concentrations from turbid sample spectra. Application of PLS to analyze blood/tissue silicone concentrations will be presented.