Methods and system for noninvasive determination of tissue analytes utilize
tissue properties as reflected in key features of an analytical signal to improve
measurement accuracy and precision. Physiological conditions such as changes in
water distribution among tissue compartments lead to complex alterations in the
measured analytical signal of skin, leading to a biased noninvasive analyte measurement.
Changes in the tissue properties are detected by identifying key features in the
analytical signal responsive to physiological variations. Conditions not conducive
to the noninvasive measurement are detected. Noninvasive measurements that are
biased by physiological changes in tissue are compensated. In an alternate embodiment,
the analyte is measured indirectly based on natural physiological response of tissue
to changes in analyte concentration. A system capable of such measurements is provided.