Abstract: The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue after interaction with the tissue; wherein the first polarization is different from the second polarization. The difference in the polarizations can discourage collection of light specularly reflected from the tissue surface, and can encourage preferential collection of light that has interacted with a desired depth of penetration or path length distribution in the tissue. The different polarizations can, as examples, be linear polarizations with an angle between, or elliptical polarizations of different handedness.

Abstract: The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue after interaction with the tissue; wherein the first polarization is different from the second polarization. The difference in the polarizations can discourage collection of light specularly reflected from the tissue surface, and can encourage preferential collection of light that has interacted with a desired depth of penetration or path length distribution in the tissue. The different polarizations can, as examples, be linear polarizations with an angle between, or elliptical polarizations of different handedness.

Abstract: The present invention provides an optical transmission device, comprising a chamber having a light input into the chamber, and having a first port allowing light to pass out of the chamber, and comprising internal surfaces where at least a portion of the surfaces is diffusely reflecting, and where at least a portion of the one or more surfaces is specularly reflecting, and where the light input and the first port and the one or more surfaces are configured such that substantially all light entering the chamber via the light source within a first predetermined aperture must encounter the diffusely reflecting portion before exiting the chamber via the first port within a second predetermined aperture. The invention can provide substantially homogenous light transmission, both as a source of light for optical systems and as a collector of light from a sample.

Abstract: The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue after interaction with the tissue; wherein the first polarization is different from the second polarization. The difference in the polarizations can discourage collection of light specularly reflected from the tissue surface, and can encourage preferential collection of light that has interacted with a desired depth of penetration or path length distribution in the tissue. The different polarizations can, as examples, be linear polarizations with an angle between, or elliptical polarizations of different handedness.

Abstract: The present invention relates to measurements of material properties by determination of the response of a sample to incident radiation, and more specifically to the measurement of analytes such as glucose or alcohol in human tissue. The invention is particularly useful in connection with noncontact optical sampling of skin. Some example embodiments of the invention provide for selection of preferred sampling locations responsive to optically-determined characteristics of the tissue. Some example embodiments of the invention provide for precise and repeatable alignment of the tissue based on optically-determined characteristics of the tissue.

Abstract: This invention relates to measurements of material properties by determination of the response of a sample to incident radiation, and more specifically to the measurement of analytes such as glucose or alcohol in human tissue. Some example embodiments of the present invention provide an optical sampling apparatus including an optical subsystem, having a receiver for receiving light expressed from tissue; and an alignment subsystem, adapted to urge a portion of a hand placed in operative relationship with the alignment subsystem into a defined configuration relative to the receiver. In some such example embodiments, the alignment subsystem includes a substrate having a plurality of projections therefrom disposed in a pattern such that the projections urge a portion of a hand placed on the substrate to a defined configuration relative to the receiver.

Abstract: The present invention relates generally to non-invasive methods and apparatuses for determining analyte properties of a subject and identity characteristics of a subject. Embodiments of the present invention provide analyte property determination and identity determination or verification from the same spectroscopic information, making unauthorized use or misleading results less likely that in systems that include separate analyte and identity determinations. The invention can be used to control and monitor individuals accessing controlled environments.

Abstract: The present invention provides methods and apparatuses for accurate noninvasive determination of tissue properties. Some embodiments of the present invention comprise an optical sampler having an illumination subsystem, adapted to communicate light having a first polarization along a first path to a tissue surface; a collection subsystem, adapted to collect light having a second polarization communicated from the tissue along a second path after interaction with the tissue; wherein the first polarization is different from the second polarization; and wherein the first path and the second path are substantially parallel for at least of portion of each path.

Abstract: An apparatus and method for non-invasive determination of attributes of human tissue by quantitative infrared spectroscopy. The system includes subsystems optimized to contend with the complexities of the tissue spectrum, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance problems, and calibration transfer problems. The subsystems include an illumination subsystem, a tissue sampling subsystem, a spectrometer subsystem, a data acquisition subsystem, and a processing subsystem. The invention is applicable, as examples, to determining the concentration or change of concentration of alcohol in human tissue.

Abstract: The present invention provides an optical transmission device, comprising a chamber having a light input into the chamber, and having a first port allowing light to pass out of the chamber, and comprising internal surfaces where at least a portion of the surfaces is diffusely reflecting, and where at least a portion of the one or more surfaces is specularly reflecting, and where the light input and the first port and the one or more surfaces are configured such that substantially all light entering the chamber via the light source within a first predetermined aperture must encounter the diffusely reflecting portion before exiting the chamber via the first port within a second predetermined aperture. The invention can provide substantially homogenous light transmission, both as a source of light for optical systems and as a collector of light from a sample.

Abstract: The present invention provides methods for generating interferometric information. Interferometric information from refractively scanned interferometers can contain errors due to wavelength-dependent refractive indices. The wavelength-dependent refractive indices of elements of the interferometer can produce errors when the OPD at a reference wavelength is different than the OPD at a sample wavelength. The invention can provide correction of interferometric information using relationships between the OPD at the wavelengths of interest, which correction can also be dependent on physical relationships among elements of the interferometer.

Abstract: An interferometer spectrometer that has reduced alignment sensitivity is described herein. Parallelism of an output ray pair formed by a single input ray is not affected by variations in relative alignment of the components. In comparison to other compensated interferometer designs, lateral separation errors in the output ray pair due to optical component misalignment are reduced. The reduced alignment sensitivity may be accomplished by utilizing simple planar components that are common to both light paths. The reduced alignment sensitivity and simplicity in design provides a more compact and more robust interferometer, with reduced manufacturing costs associated therewith. An elliptical field of view light source that utilizes an array of collimator lenses is also described. The light source provides a more compact design than a single circular collimator lens of the same area, and is suitable for single channel or multi-channel use.

Abstract: Spectroscopic system and spectrometers including an optical bandpass filter unit having a plurality of bandpass regions and a spatial encoding unit for encoding discrete frequencies of light passing through the optical filter. The incorporation of the encoding unit allows the spectrometer system to use a detector having one or a small number of elements, rather than using a more expensive detector array typically used with filter-based spectrometers. The system can also include an integrating chamber that collects the light that is not transmitted through the bandpass filter unit, and redirects this light to strike the filter unit again, resulting in a significant increase in the optical power passing through the filter. The integrating chamber maximizes the return of the reflected light to the filter assembly and minimizes optical losses. The integrating chamber may be an orthogonal design to preserve the optical geometric characteristics of the light entering the chamber.

Abstract: The present invention provides an improved interferometer design. Embodiments of the present invention provide a beam splitter, mounted with first and second reflective elements. An OPD element mounts relative to the other elements such that an optical path in the interferometer passes through the OPD element. The OPD element can be, for example, a plate comprising a refractive material mounted such that the thickness of the refractive material encountered by the optical path through the OPD element is variable. Various arrangements of components are described, and methods of constructing and methods of aligning such interferometers are also described.

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: The present invention provides means for correcting interferometer alignment errors through the use of corrective elements. The corrective elements allow reduced accuracy in the assembly process. Residual alignment errors caused by imprecise mounting of permanently mounted components can be corrected using relatively low precision positioning of corrector components. The technique can be particularly applicable to the mass production of interferometers, for which achieving and maintaining the required assembly tolerances might otherwise be prohibitively expensive. Interferometers according to the present invention can be used, for example, in optical spectroscopy and in interferometers.

Abstract: An apparatus and method for non-invasive measurement of glucose in human tissue by quantitative infrared spectroscopy to clinically relevant levels of precision and accuracy. The system includes six subsystems optimized to contend with the complexities of the tissue spectrum, high signal-to-noise ratio and photometric accuracy requirements, tissue sampling errors, calibration maintenance problems, and calibration transfer problems. The six subsystems include an illumination subsystem, a tissue sampling subsystem, a calibration maintenance subsystem, an FTIR spectrometer subsystem, a data acquisition subsystem, and a computing subsystem.

Abstract: A method and apparatus for determining an attribute of a sample from a spectrum of the sample. The invention comprises samplers and methods of sampling that provide controlled optical pathlengths through the sample, increasing the accuracy of the attribute determinations. The invention is applicable, for example, in determining analyte concentrations in biological samples, such as concentrations of analytes such as glucose in human blood.

Abstract: The present invention provides means for correcting interferometer alignment errors through the use of corrective elements. The corrective elements allow reduced accuracy in the assembly process. Residual alignment errors caused by imprecise mounting of permanently mounted components can be corrected using relatively low precision positioning of corrector components. The technique can be particularly applicable to the mass production of interferometers, for which achieving and maintaining the required assembly tolerances might otherwise be prohibitively expensive. Interferometers according to the present invention can be used, for example, in optical spectroscopy and in interferometers.

Abstract: The present invention allows detection of specific cell types based on chemical and functional characteristics of the cells. The invention can discriminate even between cells that are very similar; for example, the invention can discriminate between fetal and maternal red blood cells. The invention can also selectively alter certain cells; for example, by lysing cells of one type while leaving cells of another type unaltered. The invention has numerous applications. For example, the invention allows separation of fetal cells from maternal cells in maternal blood, allowing for fetal genetic screening without many of the drawbacks of current fetal cell acquisition techniques.