334 results about "Absorption spectroscopy" patented technology

Apparatus and method for determining at least one parameter, e. g., concentration, of at least one analyte, e. g., urea, of a biological sample, e. g., urine. A biological sample particularly suitable for the apparatus and method of this invention is urine. In general, spectroscopic measurements can be used to quantify the concentrations of one or more analytes in a biological sample. In order to obtain concentration values of certain analytes, such as hemoglobin and bilirubin, visible light absorption spectroscopy can be used. In order to obtain concentration values of other analytes, such as urea, creatinine, glucose, ketones, and protein, infrared light absorption spectroscopy can be used. The apparatus and method of this invention utilize one or more mathematical techniques to improve the accuracy of measurement of parameters of analytes in a biological sample. The invention also provides an apparatus and method for measuring the refractive index of a sample of biological fluid while making spectroscopic measurements substantially simultaneously.

A catheter based method and apparatus for reflectance generated absorption spectral analysis of chronic inflammatory vascular conditions such as seen with atherosclerotic plaque within a blood vessel or other body cavity or compartment. The use of a bright mid range infrared light (mid-IR) source yields detectable reflected optical signals that may be sampled from an area smaller or larger than the typical diameter of a mammalian cell. The mid-IR light is delivered at selected mid-infrared wavenumbers. Using the apparatus and methods, the reflectance spectra and reflectance generated absorption spectra of a target tissue can be compared to reference spectra to identify and distinguish normal epithelium from tissue containing physiological markers indicative of vascular disease or other inflammatory conditions.

Contact based rigid pin tool technology is utilized to print one or more indicator chemistries on an optical array or a disposable sheath configured on such arrays. Each indicator chemistry contains predetermined material, such as, light energy absorbing dye(s), optically responsive particles, etc., whose optical characteristics change in response to the target ligand or analyte. By spectrally monitoring such changes using fluorescence and/or absorption spectroscopy, detection and/or quantitation of the target ligand or analyte can be obtained.

A method and device for measuring a concentration of a preselected gas in a gas sample are disclosed. The device comprises a Herriott type multipass cell (10) having a center axle (74) and a housing (80A, 80B) surrounding and spaced from the axle to provide a tubular sample cavity (84). The gas sample is pumped through the sample cavity via apertures (154, 156) provided in opposed ends of the axle. A first mirror (44) and a second mirror (46) are supported at opposed ends of the axle. A light source, e.g. a laser or LED, is provided for emitting a light beam into the sample cavity via an entry aperture (30) in the first mirror, the light beam having a wave length at which the preselected gas strongly absorbs. The beam is reflected between the mirrors for a number of times before exiting the cell via an exit aperture (48) in the second mirror and impinging on a detector (52). The device further comprises a reference detector (32) for monitoring the intensity of the unattenuated light beam and a detector for detecting the intensity of light transmitted through the second mirror after a single pass through the cell. The light source is operatively connected to a heat control assembly having a heat sink and the gas sample is passed said heat sink to augment temperature control of the light source.

Techniques for providing spectroscopic imaging integrates an acousto-optic tunable filter (AOTF), or an interferometer, and a focal plane array detector. In operation, wavelength selectivity is provided by the AOTF or the interferometer. A focal plane array detector is used as the imaging detector in both cases. Operation within the ultraviolet, visible, near-infrared (NIR) spectral regions, and into the infrared spectral region, is achieved. The techniques can be used in absorption spectroscopy and emission spectroscopy. Spectroscopic images with a spectral resolution of a few nanometers and a spatial resolution of about a micron, are collected rapidly using the AOTF. Higher spectral resolution images are recorded at lower speeds using the interferometer. The AOTF technique uses entirely solid-state components and requires no moving parts. Alternatively, the interferometer technique employs either a step-scan interferometer or a continuously modulated interferometer.

A multisensor probe for continuous real-time tissue identification. The multisensor probe includes a tissue penetrating needle, a plurality of sensors useful in characterizing tissue and a position sensor to measure the depth of the needle into the tissue being diagnosed. The sensors include but are not limited to an optical scattering and absorption spectroscopy sensor, an optical coherence domain reflectometry sensor, an electrical impedance sensor, a temperature sensor, a pO₂ sensor, a chemical sensor and other sensors useful in identifying tissue. The sensors may take the form of a plurality of optical fibers extending through said needle. A retractable sheath may be disposed around the distal section of the needle to protect the needle when not in use. The sheath retracts when the probe is inserted into tissue and the position of the sheath relative to the needle may be measured to determine the needle's depth. Systems and methods for tissue identification are also provided.

Provided are novel methods of preventing deposition on an optical component in an absorption spectroscopy measurement cell. The methods involve performing an absorption spectroscopy measurement of a sample gas introduced into the cell, and introducing a flow of purge gas from a purge gas inlet pipe across a critical surface of the optical element at a velocity effective to prevent deposition on the critical surface. The gas inlet is disposed adjacent said critical surface. Also provided are devices for practicing the inventive method, measurement cells useful in absorption spectroscopy measurements, apparatuses for performing an absorption spectroscopy measurement and semiconductor processing apparatuses. The invention allows for the performance of accurate spectroscopic measurements. Because deposits are prevented from forming on the surface of an optical element, interference therefrom can effectively be avoided.

The invention discloses a multi-wavelength high-sensitivity online monitor of multi-component NH3 and H2O based on semiconductor laser absorption spectroscopy. It contains host chassis and open long-path system. Equip power receptacle, switch, fiber connector and data transmission interface. It is characterized in that: there are near-infrared semiconductor laser, semiconductor laser controller, phase-locked amplifier, signal generator, data collecting and controlling module and infrared detector in host chassis which is connected with field optical system by fiber. Open optical system contains send-receive optical telescope and multielement reflector array. Optical telescope has input and output fiber couplers. The device realizes simultaneous testing of gas multi-component by using multi-wavelength and frequency division multi-signal detecting technique.

There is provided a solid-state imaging device including a plurality of pixels that are provided on a semiconductor substrate, and that include a plurality of photoelectric-conversion units and metal oxide semiconductor transistors that selectively read signals from the plurality of photoelectric-conversion units, an organic-photoelectric-conversion film disposed on the plurality of photoelectric-conversion units, and an organic-color-filter layer disposed on the plurality of photoelectric-conversion units. Only a signal corresponding to a first color is extracted through the organic-photoelectric-conversion film. Signals corresponding to a plurality of colors not including the first color are extracted by absorption spectroscopy using the organic-color-filter layer.

A rugged, miniature, spectroscopic gas analyzer apparatus for rapid, non-invasive, multi-component breath monitoring and analysis and subsequent determination of Q or other medical diagnostic applications. The system is comprised of one or more IR emitters focussed by optical elements through a low volume sample cell receiving a sample input of a patient's breath for analysis. The patient either at rest or during exercise, inhales C₂H₂—SF₆ mixtures (balance of oxygen and nitrogen) which is subsequently monitored upon exhalation for CO₂, H₂O, C₂H₂, and SF₆ which can be employed to determine Q directly and accurately. Measurements are performed in real-time or via post-processing of stored original data. Due to its small size, ruggedness, and low power consumption, the monitor can conveniently be employed in the field or data can also be retrieved remotely using telemetry. The miniature analyzer operates on the principle of infrared absorption spectroscopy and allows very precise concentration measurements of the analytes of interest, without any bias or interference from other matrix components.

This invention discloses a method and apparatus for x-ray techniques using structured x-ray illumination for examining material properties of an object. In particular, an object with one or more regions of interest (ROIs) having a particular shape, size, and pattern may be illuminated with an x-ray beam whose cross sectional beam profile corresponds to the shape, size and pattern of the ROIs, so that the x-rays of the beam primarily interact only with the ROIs. This allows a greater x-ray flux to be used, enhancing the signal from the ROI itself, while reducing unwanted signals from regions not in the ROI, improving signal-to-noise ratios and/or measurement throughput

This may be used with a number of x-ray measurement techniques, including x-ray fluorescence (XRF), x-ray diffraction (XRD), small angle x-ray scattering (SAXS), x-ray absorption fine-structure spectroscopy (XAFS), x-ray near edge absorption spectroscopy, and x-ray emission spectroscopy.

A system for the monitoring and/or controlling emission levels of nitrogen oxide and a reductant from a stream of combustion exhaust, wherein the internal combustion engine includes a SCR unit disposed in the stream of combustion exhaust between an upstream conduit and a downstream conduit, the SCR unit having a catalyst that is configured to catalytically reduce nitrogen oxides contained in the combustion exhaust to elemental nitrogen in the presence of a reductant and oxygen, and wherein the internal combustion engine further includes a reductant injector; the system comprising: a laser absorption spectroscopy unit that is disposed in the downstream conduit and configured to measure the concentration level of at least nitrogen oxide and the reductant in the exhaust; and a control unit.

Process and system for detection of contamination in an imaging system, including providing an imaging system having one or more element having a surface for reflecting or refracting first incident radiation; mounting with respect to at least one of the one or more element one or more detector capable of sensing third radiation emitted or transmitted by one or more contaminant on the surface of the one or more element when second radiation is absorbed by the one or more contaminant; applying the first incident radiation and/or the second radiation to the at least one element; and detecting with the one or more detector the third radiation emitted or transmitted by the one or more contaminant.

A modular system for gas analysis has a first gas cell that receives and passes at least a portion of an infrared light beam through at least a portion of the first gas cell. A second gas cell disposed proximal to the first gas cell receives and passes at least a portion of the infrared light beam from the first gas cell through at least a portion of the second gas cell. At least a portion of the first gas cell and at least a portion of the second gas cell define a light path having an effective length. The system includes a means for adjusting the effective length of the light path to vary a property of the infrared light beam. Methods of making a variable effective length light path and methods of making a gas detector are also disclosed.

A cavity enhanced absorption spectrometer (CEAS) and method for controlling the same. The CEAS includes a coherent electro-magnetic radiation source, an electro-magnetic modulator that creates a sideband with an adjustable frequency that is offset from the radiation source frequency by imparting an adjustable frequency modulation to the radiation. The CEAS also includes a RF source that drives the electro-magnetic modulator and a cavity enhanced absorption resonator (CEAR) that receives the sideband. A detector measures the proximity of the frequency of the sideband relative to the resonant frequency of the CEAR and generates a proximity detector signal, which is converted by a controller to a control signal that controls at least one of the RF source and the resonant frequency of the CEAR such that the frequency of the sideband and the resonant frequency of the CEAR are adjusted to maintain a predetermined proximity therebetween.

The present invention provides a method and apparatus for detecting, by absorption spectroscopy, an isotopic ratio of a sample, by passing first and second laser beams of different frequencies through the sample. Two IR absorption cells are used, a first containing a reference gas of known isotopic ratio and the second containing a sample of unknown isotopic ratio. An interlacer or reflective chopper may be used so that as the laser frequencies are scanned the absorption of the sample cell and the reference cell are detected alternately. This ensures that the apparatus is continuously calibrated and rejects the baseline noise when phase sensitive detection is used.

An absorption spectroscopy apparatus having a fluid inlet and a fluid outlet. The apparatus includes a sample cell including an axis, a side wall having at least one curved reflective surface arrayed about the axis and facing inwardly with respect to the cell such that a beam of energy directed against a predetermined location on the reflective surface is reflected back and forth off the reflective surface and remains in substantially the same plane while inside the cell, and at least one port in the sidewall. The apparatus also includes at least one source/detector reflector having a curved profile in a plane extending perpendicular to the axis of the cell. The reflector is positioned with respect to the port of the cell to reflect energy through the port of the cell and against the predetermined location on the reflective surface of the side wall of the cell.

The invention discloses a device and a method for detecting the concentration of human respiration marking gas on line by a laser absorption spectroscopy technology. The device is characterized in that a laser temperature control plate and a laser current control plate are used for controlling a DFB (distributed feedback) laser device; a signal generator is used for generating sawtooth waves and sine waves; laser with the specific absorption wavelength is output by the laser device and collimated by an optical fiber collimator, enters a light-sound gas pool, and is reflected for multiple times by two high-reflectivity concave mirrors to interact with gas to be detected; a light-sound signal detected by a microphone is transmitted to a front amplifier, enters a phase-lock amplifier and is finally acquired and processed by a computer and a data acquisition card. The method is characterized in that a tester blows air into a vapor drying bottle through a respiration air nozzle to remove vapor and the air enters the light-sound gas pool, and an air pressure control pump, a temperature detection meter and a pressure detection meter are used for controlling the pressure in the pool and acquiring the temperature and the pressure for inverse concentration calibration. The device is unique in design and novel in structure; the in-situ online detection is performed, the complexity of other detection technologies is avoided, and the detection precision is improved.