Abstract: Systems and methods for establishing and/or maintaining the prediction capability over time of a multivariate calibration model designed for quantitative optical spectroscopic measurement of attributes or analytes in bodily tissues, bodily fluids or other biological samples, which are particularly useful when the spectral absorbance of the attribute or analyte is small relative to the background. The present invention provides an optically similar reference sample to capture the characteristics of instrument and environmental variation and to reduce the effect of such variation on the measurement capability of the model. The optically similar reference is preferably stable over time and is designed such that its optical properties are sufficiently matched to the sample of interest that instrument and environmental variations are captured in the same manner in both the test sample of interest and the optically similar reference sample.

Abstract: A method and apparatus for non-invasively measuring the concentration of an analyte, particularly blood analyte in blood. The method utilizes spectrographic techniques in conjunction with means for equilibrating the concentration of the analyte between the vascular system fluid compartment of the test area and the other tissue fluid compartment. An improved optical interface between a sensor probe and a skin surface or tissue surface of the body containing the blood to be analyzed. Multiple readings during the equilibration period are taken and utilized to show the direction and rate of charge of concentration of the analyte in the blood which is useful in optimizing therapeutic response to the collected data.

Abstract: A method and apparatus for non-invasively measuring the concentration of an analyte, particularly blood analyte in blood. The method utilizes spectrographic techniques in conjunction with equilibrating the concentration of the analyte between the vascular system fluid compartment of the test area and the other tissue fluid compartment. An improved optical interface between a sensor probe and a skin surface or tissue surface of the body containing the blood to be analyzed. Multiple readings during the equilibration period are taken and utilized to show the direction and rate of charge of concentration of the analyte in the blood which is useful in optimizing therapeutic response to the collected data.

Abstract: Damping structural vibrations by applying a multiplicity of discrete untuned passive dampers to a structure. Each passive damper includes a damping element and a damping mass, and the damping element provides damping generally in proportion to the relative velocity occurring between the mass and a point of attachment of the damper to the structure. The damping coefficients of the damping elements are selected so that the dampers increase the effective loss factor of the structure. The passive dampers each have a damping mass which is supported such that the dampers experience an undamped natural frequency below the resonant frequencies and the frequency range of the structure.