QUANTITATIVE-EVALUATION OF SKIN SURFACE-LIPIDS BY A FIBEROPTIC REFRACTOMETER

A method to quantitatively evaluate the skin surface lipids by the use of a fiber-optic refractometer is described. The method exploits the fact that the skin surface lipids tend to make the light propagating i nside the fiber core refracted into the surrounding medium thus decrea sing the sensor output. The applicability of the sensor is examined by comparison with a traditional gravimetric technique using a balance. Optical measurement results obtained from the forehead of a volunteer are related to the results by gravimetry, which indicates there is a s trong correlation between them. The practicality of the sensor is also confirmed by a bilateral symmetry test where data taken from both sid es of the forehead are related, giving a correlation coefficient of 0. 883.