Structured light synthetic interference patterns for epithelial layer thickness measurements in vivo

Inflammation has been linked to a number of diseases. Diagnosis and monitoring of these diseases would benefit from a non-ionizing and non-invasive measure of general inflammation. Optical methods for measuring relevant boundaries in tissue are difficult due to scattering. Inflammation of the oral epithelium increases its thickness from approximately 0.1 mm to 0.5 mm. Confocal methods are limited to 0.1 mm and therefore does not penetrate deeply enough. Photon migration methods typically require distances much larger than 1 mm for statistical validity. We have employed structured light to generate a synthetic interference pattern from which the depth of boundary between the oral epithelium and the underlying stroma may be quantified. Using images from phantoms, we show how the interference pattern shifts as layer thickness increases.