METHOD OF CALIBRATING AN APPARATUS FOR NON-INVASIVELY CHARACTERIZING AND CLASSIFYING THE STATE AND STRUCTURE OF A SKIN TISSUE SAMPLE AND APPARATUS FOR SUCH CHARACTERIZATION AND CLASSIFICATION

摘要

A non-invasive system for characterizing and classifying the state and structure of a tissue sample operates on a near infrared absorbance spectrum of in vivo tissue. A method that uses near-infrared spectral measurements to characterize and classify the state and structure of tissue sampled based on absorbance features related to fat in adipose tissue is provided. Also provided is a method of estimating skin fold thickness. The approach provides information about sources of tissue variability and is therefore useful for establishing the general category of the tissue structure. Categorization of subjects on the basis of the determination is suitable for further spectral analysis and the measurement of biological and chemical compounds, such as blood analytes. The invention further provides a method of estimating percent body fat based on a skin fold thickness estimate. The invention also provides an apparatus for measuring the absorbance spectra coupled with a digital processor for performing the required analyses. (FIG. -2)