Patent ID: 7761126

Claim:
An apparatus for non-invasive determination of a characteristic of change in an analyte property in tissue, comprising: a. radiation means for irradiating the tissue; b. measurement means for measuring a signal from the tissue to acquire a first output signal at a first time, and, after a first time interval, measuring a signal from the tissue to acquire a second output signal; and c. determination means for determining a characteristic of change of the analyte property in the tissue from the first and second output signals; wherein the determination means are further configured to: d. determine a set of acceptable combinations of present analyte concentration, direction of change, and rate of change of analyte concentration; e. determine whether the present analyte concentration, direction of change, and rate of change are within the set of acceptable combinations; and f. generate a signal indicative of whether the present analyte concentration, direction of change, and rate of change are within the set of acceptable combinations.