Evaluation of a chip LED sensor module at 770 nm for fat thickness measurement of optical tissue phantoms and human body tissue

We measured the fat thickness noninvasively by using a diffuse optical method for tissuesimulating phantoms and human tissues. A light source module composed of 770 nm low-power chip LEDs and a photo-detector were used in this study. The optical tissue phantoms were composed of a fat and a muscle layer made with gels with appropriate absorption/scattering coefficients. The fat thickness was varied from several to 30 mm. After a proper calibration procedure, we used this system to conduct human studies. Based on this preliminary study, noninvasive fat thickness measurements are possible with a simple curve-fitting procedure.