Abstract: An improved method and apparatus for diffuse reflectance spectroscopy. A specular control device is provided that can discriminate between diffusely reflected light that is reflected from selected depths or layers within the tissue. The specular control device permits a spectroscopic analyzer to receive the diffusely reflected light that is reflected from, for example, a first layer or depth within the tissue, while preventing the remaining diffusely reflected light from reaching the spectroscopic analyzer. Furthermore, the specular control device may prevent the specularly reflected light (e.g. surface reflected light) from reaching the spectroscopic analyzer.

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: 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: The invention relates to devices and methods that improve the quality of optic measurements from surfaces such as skin and biological materials. Three methods for reducing spectral site to site variation in fluorescence and/or reflectance signals obtained from a sample surface are: repeated measurements taken at identifiable location(s) determined by fiducial marks, repeat of measurements at different locations on the sample, and tensioning the sample surface during measurement to alleviate surface heterogeneity. Combinations of these methodologies provide best results, and are expected to improve the ability to measure blood glucose non-invasively.

Abstract: An improved method and apparatus for diffuse reflectance spectroscopy. A specular control device is provided that can discriminate between diffusely reflected light that is reflected from selected depths or layers within the tissue. The specular control device permits a spectroscopic analyzer to receive the diffusely reflected light that is reflected from, for example, a first layer or depth within the tissue, while preventing the remaining diffusely reflected light from reaching the spectroscopic analyzer. Furthermore, the specular control device may prevent the specularly reflected light (e.g. surface reflected light) from reaching the spectroscopic analyzer.

Abstract: An improved method and apparatus for diffuse reflectance spectroscopy. A specular control device is provided that can discriminate between diffusely reflected light that is reflected from selected depths or layers within the tissue. The specular control device permits a spectroscopic analyzer to receive the diffusely reflected light that is reflected from, for example, a first layer or depth within the tissue, while preventing the remaining diffusely reflected light from reaching the spectroscopic analyzer. Furthermore, the specular control device may prevent the specularly reflected light (e.g. surface reflected light) from reaching the spectroscopic analyzer.

Abstract: A method for non-invasively measuring the concentration of an analyte, particularly blood analyte in blood. The method utilizes spectrographic techniques in conjunction with an improved optical interface between a sensor probe and a skin surface or tissue surface of the body containing the blood to be analyzed. An index-matching medium is disclosed to improve the interface between the sensor probe and skin surface during spectrographic analysis. In a preferred embodiment, the blood analyte concentration in blood is quantified utilizing a partial squares analysis relative to a model incorporating analysis of plural known blood samples.

Abstract: A spectrometer having a source of broad band infrared energy, a relay mirror that focuses the infrared energy at an intercepting mirror, a first object mirror that collimates the infrared energy from the intercepting mirror, a spatial light modulator that receives the collimated infrared energy and reflects it back to the first object mirror, the spatial light modulator including deformable mirror elements, and a controller that deforms the mirror elements according to a predetermined pattern. Deformable mirror elements obtain needed spectra while reducing the mechanical complexity of the spectrometer.

Abstract: An improved method and apparatus for diffuse reflectance spectroscopy. A specular control device is provided that can discriminate between diffusely reflected light that is reflected from selected depths or layers within the tissue. The specular control device permits a spectroscopic analyzer to receive the diffusely reflected light that is reflected from, for example, a first layer or depth within the tissue, while preventing the remaining diffusely reflected light from reaching the spectroscopic analyzer. Furthermore, the specular control device may prevent the specularly reflected light (e.g. surface reflected light) from reaching the spectroscopic analyzer.

Abstract: A system for delivering infrared energy to a sample using frustrated internal reflectance in which a crystal for receiving the infrared energy is formed integrally with a removable mounting card. The mounting card is removable so that new samples can be sampled by quickly replacing the crystal with a new crystal having a new sample for analysis. Preferably, the crystal has the shape of a Fresnel lens. The infrared energy can be delivered to the crystal so that it experiences a single internal reflection and mounted in a card to form a surface that is integral with one side of the card to facilitate rapid cleaning and reuse of the card.

Abstract: A spectrometer having a source of broad band infrared energy, a relay mirror that focuses the infrared energy at an intercepting mirror, a first object mirror that collimates the infrared energy from the intercepting mirror, a spatial light modulator that receives the collimated infrared energy and reflects it back to the first object mirror, the spatial light modulator including deformable mirror elements, and a controller that deforms the mirror elements according to a predetermined pattern. Deformable mirror elements obtain needed spectra while reducing the mechanical complexity of the spectrometer.

Abstract: A method for non-invasively measuring the concentration of an analyte, particularly blood analyte in blood. The method utilizes spectrographic techniques in conjunction with an improved optical interface between a sensor probe and a skin surface or tissue surface of the body containing the blood to be analyzed. An index-matching medium is disclosed to improve the interface between the sensor probe and skin surface during spectrographic analysis. In a preferred embodiment, the blood analyte concentration in blood is quantified utilizing a partial squares analysis relative to a model incorporating analysis of plural known blood samples.

Abstract: A method for non-invasively measuring the concentration of an analyte, particularly blood analyte in blood. The method utilizes spectrographic techniques in conjunction with an improved optical interface between a sensor probe and a skin surface or tissue surface of the body containing the blood to be analyzed. An index-matching medium is disclosed to improve the interface between the sensor probe and skin surface during spectrographic analysis. In a preferred embodiment, the blood analyte concentration in blood is quantified utilizing a partial squares analysis relative to a model incorporating analysis of plural known blood samples.

Abstract: An improved apparatus for diffuse reflectance spectroscopy having a specular control device. The specular control device has at least a first surface divided into an even-numbered plurality of reflecting sections and open or transmitting sections. The number of reflecting sections is equal to the number of open sections. Each reflecting section is situated between a pair of open sections and opposite to another reflecting section. Similarly, each open section is situated between a pair of reflecting sections and is opposite to another open section. In one preferred embodiment, the total surface area of the reflecting sections is equal to the total surface area of the open sections. In another embodiment, the total surface area of the reflecting sections is unequal to the total surface area of the open sections.

Abstract: A microscope accessory uses symmetrical pairs of identical parabolic mirrors as an imaging optic to map a specimen plane with a remote focus. A mask at the remote focus defines at least one measuring area for making spectroscopic measurements while a separate viewing system simultaneously provides a wide field of view of the sample at higher magnification. The sample aperture, defines as 2 sterradians of solid angle surrounding each side of the specimen plane, is multiplexed between and among different functions--such as spectroscopic measurements and visual observations. The high numerical aperture possible using identical symmetrical aberration canceling (ISAC) optics facilitates the aperture multiplexing which has particular advantage in making reflectance measurements without any need for a significant loss of throughput efficiency.

Abstract: A microscope accessory uses symmetrical pairs of identical parabolic mirrors as an imaging optic to map a specimen plane with a remote focus. A mask at the remote focus defines at least one measuring area for making spectroscopic measurements while a separate viewing system simultaneously provides a wide field of view of the sample at higher magnification. The sample aperture, defines as 2T sterradians of solid angle surrounding each side of the specimen plane, is multiplexed between and among different functions--such as spectroscopic measurements and visual observations. The high numerical aperture possible using identical symmetrical aberration canceling (ISAC) optics facilitates the aperture multiplexing which has particular advantage in making reflectance measurements without any need for a significant loss of throughput efficiency.

Abstract: An optical system, apparatus and method for analyzing samples includes a radiant energy source, a first mask, a first mirror system, a sample plane, a second mirror system, a second mask and a detector. The first and second masks are respectively positioned along the optical path of the system in the same or different Fourier planes and/or conjugate planes thereof. The first mask has at least one inlet aperture with the relative position thereof in the first mask determining the angle of the energy incidence onto the sample. The second mask has at least one outlet aperture therein passing radiant energy therethrough which has been reflected from or transmitted through the sample at a preselected angle determined by the relative position of the second aperture in the second mask.

Abstract: An optical system, apparatus and method for analyzing samples includes a radiant energy source, a first mask, a first mirror system, a sample plane, a second mirror system, a second mask and a detector. The first and second masks are respectively positioned along the optical path of the system in the same or different Fourier planes and/or conjugate planes thereof. The first mask has at least one inlet aperture with the relative position thereof in the first mask determining the angle of the energy incidence onto the sample. The second mask has at least one outlet aperture therein passing radiant energy therethrough which has been reflected from or transmitted through the sample at a preselected angle determined by the relative position of the second aperture in the second mask.

Abstract: A universal microscope for use with a commercial FT-IR spectrophotometer comprises a visible light microscope for selecting and masking an area of a sample and an infrared microscope for sampling the masked area. The visible light microscope and the infrared microscope share a common optical path between one or more remote sample image plane masks and the sample plane such that both the visible light and the infrared radiant energy are masked twice to spatially define the same area at the sample plane. The first sample image plane mask removes energy from outside the target area at the sample focus. The second sample image plane mask removes energy from outside the target area that is diffracted by the first mask or the focusing optics. The first remote sample image plane is imaged onto the second remote image plane with the radiant energy gaining spectroscopic information and additional image information by passing through or reflecting off a sample located at the intervening sample plane.

Abstract: A spectroscopy system separates the diffuse reflectance component of a reflectance spectrum from the specular reflectance component using a remote field stop filter. The surface of the sample is placed at a focal plane of an optical system. The optical system forms an image on the surface of the sample that includes an image of the remote field stop filter. The optical system images the surface of the sample onto either the same or another remote field stop. Energy reflected from the surface of the sample which is in focus at the remote field stop retains the image information about the image of the filter, whereas energy reflected from below the surface of the sample does not necessarily retain image information about the image of the filter.