Abrégé

A device for measuring an amount of superparamagnetic material comprises a pair of measuring coils and a pair of compensating coils, wherein the coils of a pair are identical to each other. The device also includes at least one direct current generator, a low-frequency generator, and a high-frequency generator, the generators being coupled to the first and second pairs to inject into each of the coils a current having a DC component, a high-frequency component and a low-frequency component, such that the magnetic fields generated by the coils of the same pair are identical. The device also comprises a detector of a component of an electric voltage set at a mixing frequency, which is a linear combination of the first and the second frequency.

Classes IPC  ?

• G01R 33/028 - Magnétomètres électrodynamiques
• G01R 33/00 - Dispositions ou appareils pour la mesure des grandeurs magnétiques
• G01R 33/12 - Mesure de propriétés magnétiques des articles ou échantillons de solides ou de fluides
• G01N 27/74 - Recherche ou analyse des matériaux par l'emploi de moyens électriques, électrochimiques ou magnétiques en recherchant des variables magnétiques des fluides

Abrégé

An analysis medium for immunoassay comprises a substrate for promoting the natural or forced flow of a liquid sample likely to comprise analytes, the substrate having a capture zone. The capture zone comprises, immobilized on or in the substrate, a plurality of first capture agents capable of selectively retaining complexes bound to the analytes and a plurality of second capture agents capable of selectively retaining reference agents. A method for detecting the presence of analytes in a liquid sample may be performed using this analysis medium.

Classes IPC  ?

• G01N 33/543 - Tests immunologiquesTests faisant intervenir la formation de liaisons biospécifiquesMatériaux à cet effet avec un support insoluble pour l'immobilisation de composés immunochimiques
• G01N 33/49 - Analyse physique de matériau biologique de matériau biologique liquide de sang

Abrégé

The invention relates to a device (10) for measuring an amount of superparamagnetic material, the device comprising a pair of measuring coils (P1) and a pair of compensating coils (P2), the coils of a pair (P1, P2) being identical to each other. The device also includes at least one direct current generator (GDC), a low-frequency generator (GBF), and a high-frequency generator (GHF), the generators (GDC, GBF, GHF) being coupled to the first and second pairs (P1, P2) to inject into each of the coils (P1A, P1B, P2A, P2B) a current having a DC component, a high-frequency component and a low-frequency component, such that the magnetic fields generated by the coils of the same pair are identical. The device also comprises a detector of a component of an electric voltage set at a mixing frequency which is a linear combination of the first and the second frequency.

Classes IPC  ?

• G01R 33/04 - Mesure de la direction ou de l'intensité de champs magnétiques ou de flux magnétiques en utilisant le principe du déclenchement périodique de flux
• G01R 33/028 - Magnétomètres électrodynamiques
• G01R 33/12 - Mesure de propriétés magnétiques des articles ou échantillons de solides ou de fluides
• G01N 27/74 - Recherche ou analyse des matériaux par l'emploi de moyens électriques, électrochimiques ou magnétiques en recherchant des variables magnétiques des fluides
• G01N 33/543 - Tests immunologiquesTests faisant intervenir la formation de liaisons biospécifiquesMatériaux à cet effet avec un support insoluble pour l'immobilisation de composés immunochimiques

Abrégé

The invention relates to an analytical medium (1) for immunoassay comprising a substrate for promoting the natural or forced flow of a liquid sample (E) likely to comprise analytes (A), the substrate having a capture zone (1c), the analytical medium (1) being characterised in that the capture zone (1c) comprises, immobilised on or in the substrate, a plurality of first capture agents (C1) capable of selectively retaining complexes bound to the analytes (A) and a plurality of second capture agents (C2) capable of selectively retaining reference agents. The invention also relates to a method for detecting the presence of analytes (A) in a liquid sample (E) using this analytical medium (1).

Classes IPC  ?

• G01N 33/543 - Tests immunologiquesTests faisant intervenir la formation de liaisons biospécifiquesMatériaux à cet effet avec un support insoluble pour l'immobilisation de composés immunochimiques
• G01N 27/74 - Recherche ou analyse des matériaux par l'emploi de moyens électriques, électrochimiques ou magnétiques en recherchant des variables magnétiques des fluides

Abrégé

A device for measuring a magnetic material includes four coils having cores made of a superparamagnetic material, and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The value of the magnetic field is derived from the value of the direct current required to cancel an amplitude of a component at a mixing frequency. A structure of the electrical connections to the coils reduces disturbances caused by the alternating currents used with respect to the detection of the component at the mixing frequency. Moreover, specific configurations of the coils reduce the influence of stray electromagnetic radiation on the measurement results. The device can also be used to measure direct currents.

Classes IPC  ?

• G01R 15/18 - Adaptations fournissant une isolation en tension ou en courant, p. ex. adaptations pour les réseaux à haute tension ou à courant fort utilisant des dispositifs inductifs, p. ex. des transformateurs
• G01R 33/04 - Mesure de la direction ou de l'intensité de champs magnétiques ou de flux magnétiques en utilisant le principe du déclenchement périodique de flux

Abrégé

A device for measuring a quantity of a superparamagnetic material includes four coils (1-4) and a unit for injecting, into the coils, a direct current and two alternating currents of different frequencies. The quantity of superparamagnetic material is derived from an amplitude of a component at a mixing frequency, which frequency is a linear combination of the frequencies of the two alternating currents. The device is designed to reduce the influence of stray electromagnetic fields and inadvertent signal offsets on the measurement results. The device may advantageously be used for immunoassays.

Classes IPC  ?

• G01N 27/74 - Recherche ou analyse des matériaux par l'emploi de moyens électriques, électrochimiques ou magnétiques en recherchant des variables magnétiques des fluides
• G01N 33/543 - Tests immunologiquesTests faisant intervenir la formation de liaisons biospécifiquesMatériaux à cet effet avec un support insoluble pour l'immobilisation de composés immunochimiques
• G01N 33/53 - Tests immunologiquesTests faisant intervenir la formation de liaisons biospécifiquesMatériaux à cet effet
• H01F 5/04 - Dispositions des connexions électriques aux bobines, p. ex. fils de connexion

Abrégé

A device for measuring a magnetic material comprises four coils (1-4) having cores (1N-4N) made of a superparamagnetic material, and means for injecting, into the coils, a direct current and two alternating currents of different frequencies. The value of the magnetic field is derived from the value of the direct current required to cancel an amplitude of a component at a mixing frequency. A structure of the electrical connections to the coils reduces disturbances caused by the alternating currents used with respect to the detection of the component at the mixing frequency. Moreover, specific configurations of the coils reduce the influence of stray electromagnetic radiation on the measurement results. The device can also be used to measure direct currents.

Classes IPC  ?

• G01R 33/04 - Mesure de la direction ou de l'intensité de champs magnétiques ou de flux magnétiques en utilisant le principe du déclenchement périodique de flux
• G01R 15/18 - Adaptations fournissant une isolation en tension ou en courant, p. ex. adaptations pour les réseaux à haute tension ou à courant fort utilisant des dispositifs inductifs, p. ex. des transformateurs

Abrégé

A device for measuring a quantity of a superparamagnetic material comprises four coils (1-4) and means for injecting, into the coils, a direct current and two alternating currents of different frequencies. The quantity of superparamagnetic material is derived from an amplitude of a component at a mixing frequency, which frequency is a linear combination of the frequencies of the two alternating currents. The device is designed to reduce the influence of stray electromagnetic fields and inadvertent signal offsets on the measurement results . The device may advantageously be used for immunoassays.

Classes IPC  ?

• G01N 27/74 - Recherche ou analyse des matériaux par l'emploi de moyens électriques, électrochimiques ou magnétiques en recherchant des variables magnétiques des fluides