399 results about "Reflectance spectroscopy" patented technology

A device and a method to provide a more reliable and accurate measurement of hematocrit (Hct) by noninvasive means. The changes in the intensities of light of multiple wavelengths transmitted through or reflected light from the tissue location are recorded immediately before and after occluding the flow of venous blood from the tissue location with an occlusion device positioned near the tissue location. As the venous return stops and the incoming arterial blood expands the blood vessels, the light intensities measured within a particular band of near-infrared wavelengths decrease in proportion to the volume of hemoglobin in the tissue location; those intensities measured within a separate band of wavelengths in which water absorbs respond to the difference between the water fractions within the blood and the displaced tissue volume. A mathematical algorithm applied to the time-varying intensities yields a quantitative estimate of the absolute concentration of hemoglobin in the blood. To compensate for the effect of the unknown fraction of water in the extravascular tissue on the Hct measurement, the tissue water fraction is determined before the occlusion cycle begins by measuring the diffuse transmittance or reflectance spectra of the tissue at selected wavelengths.

The present invention relates to systems and methods for the measurement of analytes such as glucose. Raman and reflectance spectroscopy are used to measure a volume, of material such as a blood sample or tissue within a subject and determine a concentration of a blood analyte based thereon. The present invention further relates to a calibration method, constrained regularization (CR), and demonstrates its use for analyzing spectra including, for example, the measurement glucose concentrations using transcutaneous Raman spectroscopy.

Solid state lighting devices and illumination methods involve use of multiple solid state emitters of different colored outputs (optionally including at least one white or near-white emitter). Operation of the solid state emitters is controlled with at least one circuit element to emphasize and/or deemphasize perception of at least one color of a target surface based upon a reflectance spectral distribution of the target surface. At least one emitter may have an associated passive or active filter; the filterable emitter and/or active filter may be operated to deemphasize perception of at least one color of a target surface. Activation and/or alteration of emphasis or deemphasis of perception of color of a target surface may be selected by a user or automatically controlled.

A device and method for identifying solid and powdered materials use near-infrared reflection spectroscopy combined with multivariate calibration methods for analysis of the spectral data. Near-infrared reflection spectroscopy is employed within either the 700-1100 nm or the 900-1700 nm wavelength range to identify solid or powdered materials and determine whether they match specific known materials. Uses include identifying solid and powdered materials with a fast measurement cycle time of about 2 to 15 seconds and with a method that requires no sample preparation, as well as quantitative analysis to determine the concentration of one or more chemical components in a solid or powdered sample that consists of a mixture of components. A primary application involving identification analysis verification of the identify and purity of powdered materials used for fabricating drug tablets and capsules for quality control purposes.

The present invention provides a new method and device for disease detection, more particularly cancer detection, from the analysis of diffuse reflectance spectra measured in vivo during endoscopic imaging. The measured diffuse reflectance spectra are analyzed using a specially developed light-transport model and numerical method to derive quantitative parameters related to tissue physiology and morphology. The method also corrects the effects of the specular reflection and the varying distance between endoscope tip and tissue surface on the clinical reflectance measurements. The model allows us to obtain the absorption coefficient (μa) and further to derive the tissue micro-vascular blood volume fraction and the tissue blood oxygen saturation parameters. It also allows us to obtain the scattering coefficients (μs and g) and further to derive the tissue micro-particles volume fraction and size distribution parameters.

A cable television transmitter includes a substrate including a silicon material, control electronics disposed in the substrate, and a gain medium coupled to the substrate. The gain medium includes a compound semiconductor material. The cable television transmitter also includes an optical modulator optically coupled to the gain medium and electrically coupled to the control electronics, a waveguide disposed in the substrate and optically coupled to the gain medium, a first wavelength selective element characterized by a first reflectance spectrum and disposed in the substrate, and a second wavelength selective element characterized by a second reflectance spectrum and disposed in the substrate. The cable television transmitter further includes an optical coupler disposed in the substrate and joining the first wavelength selective element, the second wavelength selective element, and the waveguide and an output mirror.

A tunable laser includes a substrate comprising a silicon material and a gain medium coupled to the substrate. The gain medium includes a compound semiconductor material. The tunable laser also includes an optical modulator optically coupled to the gain medium, a phase modulator optically coupled to the optical modulator, and a waveguide disposed in the substrate and optically coupled to the gain medium. The tunable laser further includes a first wavelength selective element characterized by a first reflectance spectrum and disposed in the substrate, a second wavelength selective element characterized by a second reflectance spectrum and disposed in the substrate, an optical coupler disposed in the substrate and joining the first wavelength selective element, the second wavelength selective element, and the waveguide, and an output mirror.

The present invention relates to multimodal spectroscopy (MMS) as a clinical tool for the in vivo diagnosis of disease in humans. The MMS technology combines Raman and fluorescence spectroscopy. A preferred embodiment involves diagnosis cancer of the breast and of vulnerable atherosclerotic plaque, esophageal, colon, cervical and bladder cancer. MMS is used to provide a more comprehensive picture of the metabolic, biochemical and morphological state of a tissue than afforded by either Raman or fluorescence and reflectance spectroscopies alone.

The invention relates to a method for rapidly detecting the content of index components of Chinese medicinal materials by using near-infrared spectroscopy technology, which can realize the rapid detection of the comprehensive quality of Chinese medicinal materials. Collect the sample, collect the near-infrared diffuse reflectance spectrum of the sample, and preprocess the obtained spectrum, then use the detection method corresponding to the sample in the conventional method to measure the content of its index components, and combine the spectrum with the content of the index components, The quantitative analysis model is established by adopting the chemometrics method suitable for the analysis of the components of traditional Chinese medicine, the sample to be tested is crushed, and its near-infrared spectrum is scanned, and the spectrum is input into the quantitative analysis model to measure the content of the index components in the Chinese medicinal material. The whole process takes a short time, is fast and accurate, can be measured online, improves production efficiency, greatly saves manpower and material resources, and can generate huge economic and social benefits.

Spectroscopy apparatuses oriented to the critical angle of the sample are described that detecting the spectral characteristics of a sample wherein the apparatus consists of an electromagnetic radiation source adapted to excite a sample with electromagnetic radiation introduced to the sample at a location at an angle of incidence at or near a critical angle of the sample; a transmitting crystal in communication with the electromagnetic radiation source and the sample, the transmitting crystal having a high refractive index adapted to reflect the electromagnetic radiation internally; a reflector adapted to introduce the electromagnetic radiation to the sample at or near an angle of incidence near the critical angle between the transmitting crystal and sample; and a detector for detecting the electromagnetic radiation from the sample. Also, provided herein are methods, systems, and kits incorporating the peri-critical reflection spectroscopy apparatus.

Detection and tracking of an object by exploiting its unique reflectance signature. This is done by examining every image pixel and computing how closely that pixel's spectrum matches a known object spectral signature. The measured radiance spectra of the object can be used to estimate its intrinsic reflectance properties that are invariant to a wide range of illumination effects. This is achieved by incorporating radiative transfer theory to compute the mapping between the observed radiance spectra to the object's reflectance spectra. The consistency of the reflectance spectra allows for object tracking through spatial and temporal gaps in coverage. Tracking an object then uses a prediction process followed by a correction process.

A tunable pulsed laser includes a substrate comprising a silicon material and a gain medium coupled to the substrate. The gain medium includes a compound semiconductor material. The tunable pulsed laser also includes a waveguide disposed in the substrate and optically coupled to the gain medium, an optical modulator optically coupled to the gain medium, a first wavelength selective element characterized by a first reflectance spectrum and disposed in the substrate, and a second wavelength selective element characterized by a second reflectance spectrum and disposed in the substrate. The tunable pulsed laser further includes an optical coupler disposed in the substrate and joining the first wavelength selective element, the second wavelength selective element, and the waveguide and an output mirror.

A miniature medical spectrometer is provided, the spectrometer comprises: a room temperature, electrically excited, solid state two photon laser generating high intensity broad wavelength; a light projection optics, projecting said generated light on biological subject; a light collection optics, collecting reflected light from said biological subject; a wavelength selector spectrally analyzing said collected light; a detector, detecting said analyzed light; and a controller analyzing the reflected spectra and calculating result indicative of the medical state of the biological subject based on said spectrum.

A digital image monitoring system with functions of motion detection and auto iris which aims at the requirement of video-recording monitoring for traffic facilities, home or company which is composed of CCD camera, lens, frame grabber, illumination-reflectance decomposition unit, illumination variation detection unit and motion detection unit. The frame grabber accompanies with the CCD camera and lens to take digital images continuously. Then the illumination-reflectance decomposition unit decomposes the captured digital image and transfers it into the illumination and reflectance spectrum to provide the illumination detection unit to analyze the illumination spectrum variation between two adjacent image frames and thus this spectrum variation is used to control the amplification or reduction of the iris; beside ,an object movement detection unit is provided to analyze the illumination variation of two adjacent films to judge if the object in the frame is moving .

A method of determining a parameter of interest during processing of a patterned substrate includes obtaining a measured net reflectance spectrum resulting from illuminating at least a portion of the patterned substrate with a light beam having a broadband spectrum, calculating a modeled net reflectance spectrum as a weighted incoherent sum of reflectances from different regions constituting the portion of the patterned substrate, and determining a set of parameters that provides a close match between the measured net reflectance spectrum and the modeled net reflectance spectrum. For wavelengths below a selected transition wavelength, a first optical model is used to calculate the reflectance from each region as a weighted coherent sum of reflected fields from thin film stacks corresponding to laterally distinct areas constituting the region. For wavelengths above the transition wavelength, a second optical model based on effective medium approximation is used to calculate the reflectance from each region.

In order to improve fluorescence measurements, there is provided an apparatus and, a method and a computer program for optical analysis of an associated tissue sample, the apparatus comprising a spectrometer comprising an optical detector, a light source, a first light emitter 219 arranged for emitting photons into the associated tissue sample, a first light collector 221 arranged for receiving photons from the associated tissue sample, a second light emitter 223, a second light collector 225, wherein a reflectance spectrum is obtained via the first light emitter 219 and collector 221 and a fluorescence spectrum is obtained via the second light emitter 223 and collector 225, and where a first distance d1 between the first light emitter and collector is larger than a second distance d2 between the second light emitter and collector. By combining the data thus obtained, an intrinsic fluorescence spectrum may be obtained.

A method and apparatus are provided for the determination of carotenoid antioxidants and similar chemical compounds in biological tissue such as living skin. The method and apparatus provide a noninvasive, rapid, accurate, and safe determination of carotenoid levels which in turn can provide diagnostic information of the antioxidant status of tissue. Reflection spectroscopy is used to measure the concentrations of carotenoids and similar substances in tissue. White light is directed upon the area of tissue that is of interest. A small fraction of diffusively scattered light is collected and measured. The tissue is pressured to temporarily squeeze blood out of the measured tissue volume while the reflection spectrum is continuously monitored, displayed, and analyzed in near real time. After an optimal time period of typically 15 seconds, the influence of the dominating hemoglobin and oxyhemoglobin tissue absorptions on the reflection spectra are minimized.

Optical changes of tissue during wound healing measured by Near Infrared and Diffuse Reflectance Spectroscopy are shown to correlate with histologic changes. Near Infrared absorption coefficient correlated with blood vessel in-growth over time, while Diffuse Reflectance Spectroscopy (DRS) data correlated with collagen concentration. Changes of optical properties of wound tissue at greater depths are also quantified by Diffuse Photon Density Wave (DPDW) methodology at near infrared wavelengths. The diffusion equation for semi-infinite media is used to calculate the absorption and scattering coefficients based on measurements of phase and amplitude with a frequency domain or time domain device. An increase in the absorption and scattering coefficients and a decrease in blood saturation of the wounds compared to the non wounded sites was observed. The changes correlated with the healing stage of the wound. The methodologies used to collect information regarding the healing state of a wound may be used to clinically assess the efficacy of wound healing agents in a patient (e.g., a diabetic) and as a non-invasive method