Abstract:
An apparatus and method are provided for measuring the hematocrit level of blood. The presently preferred embodiment comprises a light emitting device (14) which emits an amount of light into a blood sample (12). This light travels through the blood sample to two light detecting devices (18, 20) positioned relative to the light emitting device in a predetermined geometry such that light must travel farther to reach one of the light detecting devices than to reach the other. According to the present invention, the amount of light detected by one of the light detecting devices (18, 20) is regulated so that the amount of light detected is constant. Thereafter, the amount of light detected by the unregulated light detecting device is a linear representation of the hematocrit of the blood in the blood sample. The hematocrit sensor may be used to regulate the operating parameters of an autotransfusion system to maintain the hematocrit of the blood within a predetermined range.
Abstract:
Eine Vorrichtung (1) zur Konzentrationsbestimmung einer Gaskomponente ist mit einer Strahlungsquelle (30) zu einer Abstrahlung (31) einer Lichtabstrahlung oder Wärmeabstrahlung in einem infraroten Wellenlängenbereich einer Detektoranordnung (40) mit mindestens zwei zu einer Erfassung der von der Strahlungsquelle (30) erzeugten Lichtabstrahlung oder Wärmeabstrahlung in einer Winkelanordnung (52, 62) geeignet ausgebildeten Detektorelementen (50, 60) und zwei zugeordneten Detektorelementen (50, 60) Filterelementen (51, 61) ausgestaltet. Zumindest eines der zwei Detektorelemente (50, 60) ist in einer Winkelanordnung (52, 62) in Bezug zu einer vertikalen Achse (32) ausgerichtet, so dass sich bedingt durch die Winkelanordnungen (52, 62) ein Überlappungsbereich (65) ergibt. Der Überlappungsbereich (65) bewirkt, dass Dämpfungen in der Lichtausbreitung, welche beispielsweise durch Gasmoleküle oder Feuchtigkeit (400) bedingt sein können, sich auf beide Detektorelemente (50, 60) auswirken und damit hinsichtlich der Konzentrationsbestimmung kompensiert sind.
Abstract:
The invention relates to a device for recording an absorption spectrum of a fluid, with a first radiation source (1) that emits a radiation in a first spectral range along a first beam path (11), with a first measuring path (5), along which the radiation passes through the fluid and which is arranged in the first beam path (11), with a tunable Fabry-Perot interferometer (7), which is arranged in the first beam path (11) and can transmit radiation in the first spectral range as a displaceable bandpass filter, and with a first detector (9, 35) for measuring the intensity of the radiation in the first spectral range. According to the invention, the device has a first etalon (3), which is arranged for spectral modulation of radiation in the first beam path (11) and which has a plurality of transmission maxima (17) in the first spectral range, and the Fabry-Perot interferometer (7) is designed such that the bandpass filter formed by the Fabry-Perot interferometer (7) can be displaced across the first spectral range in such a manner that the spectral modulation of the radiation by the first etalon (3) can be measured by the first detector (9, 35) as a modulation over time of the radiation intensity.
Abstract:
Absorption-biased NDIR gas sensors can be recalibrated by adjusting a calibration curve obtained from a gamma ratio ("G") that has been normalized by the gamma ratio when no sample gas is present in the sample chamber ("G o "), G being the ratio of a signal channel output ("V s ") of the NDIR gas sensor divided by a reference channel output ("V R ") of the NDIR gas sensor. An AB NDIR gas sensor uses an identical spectral narrow band pass filter for wavelength selection for both a signal channel having a signal channel pathlength and a reference channel having a reference channel pathlength and an absorption bias is applied to the signal channel by making the signal channel path length longer than the reference channel pathlength. Recalibration can be achieved by adjusting Go based upon a reversed calibration curve algorithm that uses a concentration of sample gas determined by a master NDIR gas sensor. Alternatively, the NDIR gas sensor can be self- recalibrating by using a stored standard gamma ratio and a measured standard gamma ratio and a self-calibration algorithm to correct the calibration curve.
Abstract:
The biological information imaging apparatus includes an acoustic wave detector 107 that detects an acoustic wave that is generated from a light absorber 105 and converts it to a first electrical signal; a photo-detector 110 that detects intensities of the light corresponding to a plurality of propagation distances of the light which propagates through the specimen 110 and converts it to a second electrical signal; a signal processing apparatus 111 that derives an average effective attenuation coefficient µ eff of the specimen 110 based on the second electrical signal and derives an optical absorption coefficient µ a of the specimen 110 based on the first electrical signal and the average effective attenuation coefficient µ eff ; and an image constructing apparatus 111 that constructs an image of the distribution of the optical absorption coefficient µ a based on the distribution of the optical absorption coefficient µ a .
Abstract:
The invention relates to a method for monitoring the condition of a medium (50), based on the transmission/emission of light in a channel (33), in which - a light is conducted through a medium layer defined by a measuring gap (13.1) in a measuring head (12) pushed in from an opening (31) in the wall (30) of the channel (33), - the intensity of the light, or a variable proportional to it is measured through the medium layer, and - the condition of the medium is evaluated, using measuring electronics (15), from the intensity of the change, according to set criteria. The measurement is performed using a sensor (10) with a compact measuring head, in which the measuring electronics (15) are essentially outside the channel (33), and in which the light is conducted to the measuring gap and away from the measuring gap by optical-fibre means (18, 18.1, 18.2). In addition, the invention also relates to a corresponding device (10).
Abstract:
L'invention se rapporte à un procédé de détermination photométrique in vitro du contenu d'un analyte dans un échantillon. L'échantillon est placé dans un dispositif de mesure possédant une chambre de mesure qui a une longueur de chemin de rayonnement définie et au moins une partie de paroi partiellement transparente. La chambre de mesure est en communication optique avec un système optique adapté à l'analyte et comportant une source de rayonnement et un détecteur de rayonnement. En outre, on peut régler la configuration de la chambre de mesure, ceci permettant de contrôler l'ajustement de la longueur du chemin de rayonnement traversant la chambre de mesure. Dans une première étape de mesurage, on règle la première longueur de chemin de rayonnement traversant la chambre de mesure et on émet, à au moins une longueur d'onde, le rayonnement provenant de la source de rayonnement et passant par la chambre de mesure pour se diriger vers le détecteur de rayonnement. Puis, dans une seconde étape, on ajuste la forme de la chambre de mesure, réglant ainsi une seconde longueur d'onde traversant la chambre de mesure. On émet à nouveau, à la même longueur d'onde que celle émise lors de la première étape, un rayonnement provenant de la source de rayonnement et passant par la chambre de mesure pour se diriger vers le détecteur de rayonnement. Le contenu de l'analyte est ainsi déterminé sur la base du rayonnement détecté à chaque étape de mesurage.
Abstract:
PROBLEM TO BE SOLVED: To provide a double path cell for an automatic analyzer and an analysis method using the cell, which is a reaction/measurement cell storing a liquid to be measured such as a blood specimen, and adapted to measure a plurality of absorbances of the same liquid to be measured to enlarge a measurement range, thereby decreasing dilution of high-concentration specimen and re-examination so as to make high-accuracy measurement for a low-concentration specimen, and detecting foreign matter in the liquid to be measured. SOLUTION: In this double path cell, a cell formed of transparent material storing a liquid to be measured is passed through a measurement optical path disposed to cross a transfer path for the cell, thereby measuring absorbance of the liquid to be measured, a plurality of stepped parts different in optical path length are formed in the cell, and the measurement light is transmitted through the respective stepped parts of the cell. Thus, a plurality of different absorbances can be obtained. COPYRIGHT: (C)2004,JPO