1574 results about "Photometer" patented technology

A method and apparatus for non-invasively determining the blood oxygen saturation level within a subject's tissue is provided that utilizes a near infrared spectrophotometric (NIRS) sensor capable of transmitting a light signal into the tissue of a subject and sensing the light signal once it has passed through the transmitting a light signal into the subject's tissue, wherein the transmitted light signal includes a first wavelength, a second wavelength, and a third wavelength; (2) sensing a first intensity and a second intensity of the light signal, along the first, second, and third wavelengths after the light signal travels through the subject at a first and second predetermined distance; (3) determining an attenuation of the light signal for each of the first, second, and third wavelengths using the sensed first intensity and sensed second intensity of the first, second, and third wavelengths; (4) determining a difference in attenuation of the light signal between the first wavelength and the second wavelength, and between the first wavelength and the third wavelength; and (5) determining the blood oxygen saturation level within the subject's tissue using the difference in attenuation between the first wavelength and the second wavelength, and the difference in attenuation between the first wavelength and the third wavelength.

A living body is irradiated with a first light beam having a first wavelength and a second light beam having a second wavelength which is different from the first wavelength. The first light beam and the second light beam, which have been reflected or transmitted from the living body, are converted into a first electric signal corresponding to the first wavelength and a second electric signal corresponding to the second wavelength, as the observed pulse data. A light absorbance ratio obtained from the first electric signal and the second electric signal is computed, for each one of frequency ranges dividing an observed frequency band. It is determined that noise is not mixed into the observed pulse wave data in a case where a substantial match exists among light absorbance ratios computed for the respective frequency ranges.

Disclosed is a photometer that employs high dynamic range (HDR) image processing and manipulation algorithms for capturing and measuring real-time sky conditions for processing into control input signals to a building's automated fenestration (AF) system, daylight harvesting (DH) system and HVAC system. The photometer comprises a color camera and a fitted fish-eye lens to capture 360-degree, hemispherical, low dynamic range (LDR) color images of the sky. Both camera and lens are housed in a sealed enclosure protecting them from environmental elements and conditions. In some embodiments the camera and processes are controlled and implemented by a back-end computer.

The specification discloses a portable spectrophotometer (10) providing improved movement and control of the sample (S) during analysis. The unit (10) includes a base (12) and an upper assembly (14) supported on the base (12) for floating movement. Both a spectral measurement engine (20) and drive rollers (104) are contained within the upper assembly. The base (12) includes independently suspended idler rollers (16), and the drive rollers (104) engage the idler wheels (16), so that at least a portion of the weight of the upper assembly (14) is borne by the engaging drive rollers (104) and idler rollers (16). The upper assembly (14) therefore floats up and down with samples (S) of varying thickness moving between the rollers (104 and 16). Additional upstream idler rollers (18 and 24) on the base and the upper assembly engage one another and bear a portion of the weight of the upper assembly (14) to create tension in opposition to the drive rollers (104) to hold the sample (S) taut. A planar media guide (130) is located on the underside of the upper assembly (14) and surrounds the spectral engine (20) to engage the sample (S) and reduce flexing and bowing of the sample (S). A manually actuated backer (30) is supported by the base (12) to selectively present to the spectral engine (20) one of two areas (52a and 52b) with different reflective properties. The unit (10) may include a first light source (21) in the spectral engine and a second light source (60) in the backer (30) so that the spectrophotometer (10) is capable of both reflective and transmissive analysis.

Methods, apparatuses, machine readable non-transitory storage media, and systems which process measured light values in order to determine the status of a golf club relative to a golf club bag are described. In one embodiment, a system uses a floating threshold, which is between a running bright average and a running dark average, to determine whether to add a current light meter value to one or the other of these running averages. In another embodiment, a system resets or re-seeds the running averages so that re-seeded averages are used after exiting from a sleep state such as a dark sleep state. In another embodiment, a system uses light sensor information or other sensor information to determine when a club is in use. Other embodiments are also described.

Described is a method for calibrating a spectrophotometric apparatus which is used to measure analytes in plasma and/or serum samples based on the calibration of a First Apparatus, and for recalibrating such apparatus, including recalibration of the First Apparatus all using synthetic calibrators. These apparatus use absorption of radiation to measure analytes in serum or plasma samples. The method described includes using synthetic calibrators which are submitted to the First Apparatus for measurement and compared with measurements of similar calibrators in a Second Apparatus and using the comparison to derive concentrations of analytes in samples measured on the Second Apparatus. As an alternative to making all apparatus identical, in terms of wavelength calibration, the absorbances of all apparatus should be mapped onto a standard set of wavelengths.

A photometric or spectrophotometric apparatus and method wherein a sample is contained in a pipette held between two surfaces, one containing a photometric or spectrophotometric source and the other a photometric or spectrophotometric detector and an optical path is established through the walls of the pipette tip and through the sample between the two surfaces. Use of a disposable pipette tip which may be left attached to pipette tip during sample analysis or reattached to the pipette device following analyses, provides a means to recover the sample for subsequent applications and manipulations, and enables especially small volume samples to be analysed.

Disclosed are photometric methods and devices for determining optical pathlength of liquid samples containing analytes dissolved or suspended in a solvent. The methods and devices rely on determining a relationship between the light absorption properties of the solvent and the optical pathlength of liquid samples containing the solvent. This relationship is used to establish the optical pathlength for samples containing an unknown concentration of analyte but having similar solvent composition. Further disclosed are methods and devices for determining the concentration of analyte in such samples where both the optical pathlength and the concentration of analyte are unknown. The methods and devices rely on separately determining, at different wavelengths of light, light absorption by the solvent and light absorption by the analyte. Light absorption by the analyte, together with the optical pathlength so determined, is used to calculate the concentration of the analyte. Devices for carrying out the methods particularly advantageously include vertical-beam photometers containing samples disposed within the wells of multi-assay plates, wherein the photometer is able to monitor light absorption of each sample at multiple wavelengths, including in the visible or UV-visible region of the spectrum, as well as in the near-infrared region of the electromagnetic spectrum. Novel photometer devices are described which automatically determine the concentration of analytes in such multi-assay plates directly without employing a standard curve.

A spectrophotometer includes a plurality of LEDs arranged in a circular array, each having a calibrated power input determined by the use of pulse width modulation and each having a unique wavelength band determined by the utilization of a unique fluorescent phosphor coating or lens. At least one of the LEDs comprising a phosphor-free high energy UV LED. Light reflected to the spectrophotometer is divided into predetermined wavelength ranges through the utilization of a linear variable filter and photo detectors wherein the analog signal from a photo detector is converted to a digital value through the use of auto-ranging gain technique.

A 3D OCT confocal imaging apparatus includes a light source module for providing an illumination beam with wider bandwidth from a crystal fiber; a reference source module; a pickup module; a beam splitter; an optical filter; and a sensor module. When the illumination beam illuminates a sample, a pickup objective lens and a piezoelectric actuator of the pickup module together provide an image beam scanning the sample in depth direction. The image beam and a reference beam from the reference source module together form an interference image beam, which is converted by a photosensor into a coherence image electric signal. Meanwhile, the interference image beam passes through a pinhole to form a confocal image, which is converted by an excited light photometer into a confocal image electric signal. With an image processing system, a 3D OCT confocal microscopic image of the sample can be produced from these image electric signals.

A system for luminance characterization of a luminaire includes a ballast coil and a multi-tap capacitor connected in series with the ballast coil. The multi-tap capacitor has a plurality of tap capacitors integrated into a capacitor housing. A plurality of switches are each coupled to one of the plurality of tap capacitors for selectively coupling the tap capacitors together to produce a multi-tap capacitance corresponding to a configuration of the plurality of switches. A lamp is connected in series with the multi-tap capacitor and the ballast coil. A photometer is located to measure light intensity of the lamp and to produce a lumen output measurement. A memory is used to store a database having a plurality of lumen output measurements, each corresponding to a multi-tap capacitance corresponding to all configurations of the plurality of switches.

A spectrophotometric scanner suitable for producing spectral reflectance images of surfaces of samples for a plurality of wavelength bands is disclosed. The spectrophotometric scanner comprises a scanner head for collecting spectral reflectance data, a positioning mechanism for positioning the scanner head in relation to a surface, and a computing device for controlling the mechanism and recording and analyzing the spectral reflectance data. The computing device directs the positioning mechanism to position the scanner head on a row of locations in a grid of locations of the surface; directs the scanner head to measure spectral reflectance data for each location in the row of locations; records and analyzes the spectral reflectance data; and produces spectral reflectance images from the spectral reflectance data. A light source in the scanner head comprises a plurality of sequentially controllable LEDs, each producing light in a different wavelength band.

Method and apparatus of spectroscopy or the like on extremely small samples in which a drop is held between two opposing surfaces by surface tension and one surface is controllably toward and away from the other. To provide and transmit exciting energy through the drop for measurement, optical fibers go through a surface and finish flush with the surface. One of the surfaces can be swung clear of the other for easy cleaning between tests. Means for determining wetted surface are provided.

An apparatus and related method for optical calibration of spectrophotometers is described. The apparatus is a calibration plate including one or more cuvettes filled with solutions of interest. The cuvettes are sealed to prevent evaporation. The cuvettes also possess a compressible component to allow for expansion of the solution and a bubble control apparatus to ensure that the compressible component does not intersect the beam path. A piece of neutral density glass is optionally included in the apparatus to track optical changes of the solutions over time.