1126 results about "Fluorescence spectrometry" patented technology

Improved systems, devices, and methods measure and/or change the shape of a tissue surface, particularly for use in laser eye surgery. Fluorescence of the tissue may occur at and immediately underlying the tissue surface. The excitation energy can be readily absorbed by the tissue within a small tissue depth, and may be provided from the same source used for photodecomposition of the tissue. Changes in the fluorescence spectrum of a tissue correlate with changes in the tissue's hydration.

A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier. Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam (e.g., at a wavelength of 600 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed.

A method based on time-resolved, laser-induced fluorescence spectroscopy for the characterization and fingerprinting of petroleum oils and other complex mixtures. The method depends on exciting the wavelength-resolved fluorescence spectra of samples using ultraviolet pulsed laser radiation, measuring them at specific time gates within the temporal response of the excitation laser pulse, and comparing them in terms of their shapes alone without taking into account their relative intensities. The method provides fingerprints of crude oils without resorting to any kind of approximation, for distinguishing between closely similar crude oils of the same grade, and is useful in remote and non-remote setups, along with applications in fingerprinting blended and non-blended crude oils using different ultraviolet excitation wavelengths. Applications include estimating °API gravity of crude oils and monitoring degradation of mineral oils.

A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier.

Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam at a selected wavelength (e.g., at a wavelength of about 400 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum. In certain embodiments, the detecting step may be followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level and/or brain level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing methods are also disclosed.

An X-ray fluorescence spectrometric system includes a sample pre-treatment apparatus 10 for retaining on a surface of a substrate a substance to be measured that is found on the surface of the substrate, after such substance has been dissolved and subsequently dried, an X-ray fluorescence spectrometer 40, and a transport apparatus 50 for transporting the substrate from the sample pre-treatment apparatus towards the X-ray fluorescence spectrometer, which system as a whole is easy to operate. This spectrometric system also includes a control apparatus 50 for controlling the sample pre-treatment apparatus 10, the X-ray fluorescence spectrometer 40 and the transport apparatus 50 in a totalized fashion.

The relative intensity of fluorescent light of a melt-polycondensed aromatic polycarbonate produced by the transesterification process (melt polymerization process) of an aromatic dihydroxy compound and a carbonic acid diester in the presence of a catalyst comprising a basic nitrogen compound and/or a basic phosphorus compound in combination with an alkali metal compound is suppressed to 4.0x10-3 or below at a wavelength of 465 nm based on a standard substance in a fluorescent light spectrum obtained by the excitation wavelength of 320 nm. An aromatic polycarbonate having good color stability, especially good stability to the deterioration of the chip color during storage of the chip in air at room temperature can be produced by the present invention.

A method of using picosecond scan camera to simultaneously obtain fluorescent light spectrum and fluorescent lifetime of sample includes focusing blue violet light emitted by laser on sample by objective to excite sample single photon, collecting fluorescent from sample then splitting it and focusing it to be image on photoelectric cathode of picosecond scan camera, setting dispersion direction of fluorescent to be the same as slit direction of said camera but to be vertical to scan direction in order to measure out fluorescent lifetime of different light spectrum simultaneously under coaction of scan circuit and image intensifier deflection system.

A multichannel fluorosensor includes an optical module and an electronic module combined in a watertight housing with an underwater connector. The fluorosensor has an integral calibrator for periodical sensitivity validation of the fluorosensor. The optical module has one or several excitation channels and one or several emission channels that use a mutual focusing system. To increase efficiency, the excitation and emission channels each have a micro-collimator made with one or more ball lenses. Each excitation channel has a light emitting diode and an optical filter. Each emission channel has a photodiode with a preamplifier and an optical filter. The electronic module connects directly to the optical module and includes a lock-in amplifier, a power supply and a controller with an A/D converter and a connector. The calibrator provides a response proportional to the excitation intensity, and matches with spectral parameter of fluorescence for the analyzed fluorescent substance.

A device to illuminate a object, to excite its fluorescence light emission, and detect the emitted fluorescence spectrum, comprising: at least one illumination system (13), adapted to receive light from a light source (11), to select at least one wavelength bands of light spectrum of the source (11), to illuminate a object (15) with light filtered in that way (14); and a detection system (17), adapted to detect fluorescence light (16) emitted by the object (15), to select at least one wavelength bands of fluorescence, light spectrum (16), to record the spectrum of the filtered light; characterized in that said illumination system (13) comprises: at least one first dispersive element (41), at least one focusing optics (43), at least one spatial fitter of excitation (44), at least one collimating optics (45) and at least one second dispersive element (47), wherein said detection system (17) comprises: at least one dispersive element (81), at least one focusing optics (83), at least one spatial filter of detection (84), at least one imaging optics (85) and at least one light detector (87).

The present invention provides systems and methods for the determination of the physical characteristics of a structured superficial layer of material using light scattering spectroscopy. The light scattering spectroscopy system comprises optical probes that can be used with existing endoscopes without modification to the endoscope itself. The system uses a combination of optical and computational methods to detect physical characteristics such as the size distribution of cell nuclei in epithelial layers of organs. The light scattering spectroscopy system can be used alone, or in conjunction with other techniques, such as fluorescence spectroscopy and reflected light spectroscopy.

The invention comprises an apparatus and method for simple fluorescence spectrometry in a downhole environment using a UV light source and UV fluorescence to determine a parameter of interest for a sample downhole. The UV light source illuminates the fluid, which in turn fluoresces light. The fluoresced light is transmitted back towards the UV light source and through the pathway towards an optical spectrum analyzer. API gravity is determined by correlation the wavelength of peak fluorescence and brightness of fluorescent emission of the sample. Asphaltene precipitation pressure is determined by monitoring the blue green content ratio for a sample under going depressurization.

Measurements of fluorescence spectra of fluid samples recovered downhole are processed to give the fluid composition. The processing may include a principal component analysis followed by a clustering method or a neutral network. Alternatively the processing may include a partial least squares regression. The latter can give the analysis of a mixture of three or more fluids.

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.

The present invention comprises an optical apparatus, methods and uses for real-time (video-rate) multimodal imaging, for example, contemporaneous measurement of white light reflectance, native tissue autofluorescence and near infrared images with an endoscope. These principles may be applied to various optical apparati such as microscopes, endoscopes, telescopes, cameras etc. to view or analyze the interaction of light with objects such as planets, plants, rocks, animals, cells, tissue, proteins, DNA, semiconductors, etc. Multi-band spectral images may provide morphological data such as surface structure of lung tissue whereas chemical make-up, sub-structure and other object characteristics may be deduced from spectral signals related to reflectance or light radiated (emitted) from the object such as luminescence or fluorescence, indicating endogenous chemicals or exogenous substances such as dyes employed to enhance visualization, drugs, therapeutics or other agents. Accordingly, one embodiment of the present invention discusses simultaneous white light reflectance and fluorescence imaging. Another embodiment describes the addition of another reflectance imaging modality (in the near-IR spectrum). Input (illumination) spectrum, optical modulation, optical processing, object interaction, output spectrum, detector configurations, synchronization, image processing and display are discussed for various applications.

A system and method for locating and identifying unknown samples. A targeting mode may be utilized to scan regions of interest for potential unknown materials. This targeting mode may interrogate regions of interest using SWIR and/or fluorescence spectroscopic and imaging techniques. Unknown samples detected in regions of interest may be further interrogated using a combination of Raman and LIBS techniques to identify the unknown samples. Structured illumination may be used to interrogate an unknown sample. Data sets generated during interrogation may be compared to a reference database comprising a plurality of reference data sets, each associated with a known material. The system and method may be used to identify a variety of materials including: biological, chemical, explosive, hazardous, concealment, and non-hazardous materials.

A sample preprocessing system for a fluorescent X-ray analysis includes a sample preprocessing apparatus for retaining on a surface of a substrate a substance to be measured that is found on the surface of the substrate, after such substance has been dissolved and subsequently dried, a transport apparatus for transporting the substrate, and a control apparatus for controlling the sample preprocessing apparatus and the transport apparatus. The control apparatus 60 after having confirmed that the pressure difference between inside and outside of the apparatus 10 (20, 30) and the concentration of the reactive gas within the apparatus are within a predetermined range causes automatically opening and closing shutters 21a, 27 and 31a to thereby avoid a possible corrosion of the apparatuses positioned outside the sample preprocessing apparatus while increasing the service lifetime thereof.