402 results about "Reflectance spectroscopy" patented technology

In accordance with the invention, a low coherence interferometer is used to non-invasively monitor the concentration of glucose in blood by shining a light over a surface area of human or animal tissue, continuously scanning the light over a two dimensional area of the surface, collecting the reflected light from within the tissue and constructively interfering this reflected light with light reflected along a reference path to scan the tissue in depth. Since the reflection spectrum is sensitive to glucose concentration at particular wavelengths, measurement and analysis of the reflected light provides a measure of the level of glucose in the blood. The measurement of glucose is taken from multiple depths within blood-profused tissue, and sensitivity is preferably enhanced by the use of multiple wavelengths. Noise or speckle associated with this technique is minimized by continuously scanning the illuminated tissue in area and depth.

The invention provides systems for automatically localizing areas of disease within a tissue sample using fluorescence spectra, reflectance spectra, and video images obtained from the sample. The invention further provides systems for displaying, marking, and treating the identified areas so that healthy surrounding tissue suffers minimal impact upon treatment and / or excision of the diseased tissue. The invention facilitates minimally-invasive treatment by accurately directing treatment to only those areas that are identified as diseased.

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.

The invention was originally developed to determine the strain-relief capability of a fusion splice protector as well as the compressive stress imparted to a fusion splice by the splice protector. The invention also permits performance and comparative analyses of splice protectors as well as any package in which the optical fiber is at least partially disposed. To those ends a fiber Bragg grating (FBG) is axially arranged relative to the package such that a free or reference section of the FBG protrudes from the package while a shielded section lies within the package. Broadband light is supplied to the FBG which reflects certain wavelengths that are measured by an optical spectrum analyzer. The FBG reflected spectra will be split into two peaks as the reference and shielded sections experience different amounts or types of stress thereby providing a powerful analysis tool. A wavelength shift in the reflected spectra reveals the amount of stress experienced by the reference and free sections and permits a qualitative and quantitative analysis of the stress applied by the package and the package's ability to protect fiber from stress (e.g. such as that imposed by a tension pull test). Measurements may be made after a variety of conditions are changed such as splice protector curing, axial tension application, axial tension release, time, and age accelerating environments. Comparative studies and various other calculations may also be performed to evaluate different packages.

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 system and method that enable real-time optical measurements of tissue reflection spectral characteristics while performing ablation, involves the radiation of tissue and recapturing of light from the tissue to monitor changes in the reflected optical intensity as an indicator of steam formation in the tissue for prevention of steam pop. The system includes a catheter adapted to collect light reflected from tissue undergoing ablation, a detection component that identifies and separates constituent wavelengths of collected light, a quantification apparatus for generating measured light intensity data for the collected light, and a processor that analyses the measured light intensity data in relation to time. The system may include a graphical display and / or an audio output (e.g., speaker) that provide visual and / or audio alarm when the system infers formation of a steam pocket in the tissue. The method for monitoring formation of steam pocket during ablation, wherein a measured reflectance spectral intensity MRSI versus time is analyzed, includes delivering light to tissue, delivering energy for ablation at tissue and measuring the reflectance spectral intensity of the tissue, wherein observation is made as to whether the MRSI initially increases in a specified time period followed by a decrease at a specified rate in the MRSI. If there is no decrease in the MRSI, then delivery of ablation energy to tissue continues. However, if there is a decrease in the MRSI within a specified time and at a specified rate, then the method infers the formation of a steam pocket and decreases or discontinues the delivery of ablative energy to tissue.

Methods and apparatus are provided for endpoint detection in a chemical mechanical planarization (CMP) process. Reflectance spectra data is taken periodically in different areas of a surface of a semiconductor wafer during a chemical mechanical planarization process. Three different reflectance spectra are identified to determine a status of the CMP process. A first reflectance spectra data corresponds to light reflected predominately from a layer of material on the surface of the semiconductor wafer. A second reflectance spectra corresponds to the layer of material being thinned such that the second reflectance spectra is modified by an underlying layer of material. A third reflectance spectra corresponds to light reflected predominately from the underlying layer of material.

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.

A multimodal probe system for spectroscopic scanning of tissue for disease diagnosis. The system can use diffuse reflectance spectroscopy, fluorescence spectroscopy and Raman spectroscopy for the detection of cancerous tissue, such as tissue margin assessment.

The invention discloses a grain moisture content detecting method based on a hyperspectral image technology, which comprises the following steps: respectively acquiring an all black calibrated image B, an all white calibrated image W and a hyperspectral original data image I of grains the moisture content of which is given; carrying out reflection spectral correction on the hyperspectral original data image I of grains by the all black calibrated image B and the all white calibrated image W to obtain a corrected image R of grains; extracting the grain image from the corrected image R; carrying out spectral correction by a moving average method and multiplicative scatter correction; calculating the correlation coefficients of spectral reflection values and the moisture content; selecting a correlation coefficient as the maximum spectral reflection value to be input into an artificial neural network; and establishing a grain moisture prediction model. In the invention, the grain moisture content is detected by the artificial neural network according to the spectral signature of the grains caused by the moisture content, a quick stable method is provided, and the detecting efficiency is improved.

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 spectrometer for infrared reflectance measurements of samples for identification of the sample materials is built into a steering wheel assembly. The spectrometer includes a window and optics on a bench adjacent the window, so that the optics will be aligned with the sample when the device is placed in optical alignment with or directly against the sample. The optics include a broad-band IR light source (ordinary lamp) shining onto an acousto-optic tunable filter (AOTF), which passes narrow-band IR light with a swept frequency; a lens focusing the IR through the window onto the sample; and a reflectance detector aligned with the window of the spectrometer to pick up reflected light. A computer, which may be mounted in the spectrometer, compares the detected reflectance spectrum with stored sample data spectra, and identifies the material or the components of the material and their proportions. When a control substance is detected an alarm signal is produced.

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.

Apparatus and method for efficiently assessing the results of reflectance spectroscopy on a soil sample to determine the presence of contaminants in the soil, by constructing a model based on analysis of known samples. The model may be constructed using an all possibilities approach and data mining techniques, on a range of samples, for example of different kinds of soil without pollutants and with different levels of pollutants. The Disclosure relates both to the construction of the model and to its use in the field in analyzing soil contaminants.

The invention relates to a spectral reflectance peak decomposition based quantitative inversion method of the hyperspectral remote sensing mineral content. The method comprises the seven steps of: 1. reading data in; 2. intercepting a reflection peak band; 3. converting a reflectance spectrum and an absorption spectrum; 4. carrying out continuum removal on the spectrums; 5. linearly decomposing the spectrums to obtain the mineral spectrum decomposition content; 6. establishing a statistical relationship between the mineral spectrum decomposition content and the real content; and 7. converting the calculated mineral spectrum decomposition content in the step 5 into the real mineral content according to the established statistical relationship in the step 6. The invention can not only be applied to hyperspectral data which is not covered by a mineral absorption spectrum band, but also can be used for hyperspectral data which is covered by the mineral absorption spectrum band in the spectrum band range, carries out quantitative mineral content inversion by comprehensively applying a spectral reflectance peak and an absorption spectrum band and improves the inversion precision and the inversion accuracy. The invention has practical value and broad application potential in the field of hyperspectral remote sensing mineral identification.

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.

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 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