Process and device for determining an analyte contained in a scattering matrix
First Claim
1. Method for determining an analyte in a scattering, in particular biological, matrix, in whichin a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, said interaction including optical absorption andin an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step,wherein, using a confocal measuring arrangement, a first depth selection means is provided such that the primary light is focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface,the region of focus is imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus,wherein for generating a measurement signal allowing a selective analysis of an analyte which causes only a small share of the optical absorption, light reflected from a defined measuring depth below the interface is detected selectively as secondary light by a second depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein the analyte comprises glucose.
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Accused Products
Abstract
Method for determining an analyte in a scattering matrix. In a detection step detection measurements are made in which light is irradiated into the matrix as primary light and light leaving the scattering matrix is detected as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix. Information on the presence of the analyte in the matrix is determined in an evaluation step. The determination of optically weakly absorbing analytes against a strongly absorbing interference background is improved by the use of two selection methods for the depth selective detection of the secondary light in combination with one another. Primary light is focused by means of a primary light optically focussing element onto a region of focus lying in the matrix at a predetermined measuring depth and the region of focus is imaged by means of a secondary light optically focusing element onto a light entry aperture arranged in the light path of the secondary light to the detector. In addition to this first depth selection by a confocal arrangement, a second depth selection device is used to detect light reflected from a defined measuring depth as secondary light, with the measuring depth coinciding with the depth of focus.
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Citations
29 Claims
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1. Method for determining an analyte in a scattering, in particular biological, matrix, in which
in a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, said interaction including optical absorption and in an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step, wherein, using a confocal measuring arrangement, a first depth selection means is provided such that the primary light is focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface, the region of focus is imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus, wherein for generating a measurement signal allowing a selective analysis of an analyte which causes only a small share of the optical absorption, light reflected from a defined measuring depth below the interface is detected selectively as secondary light by a second depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein the analyte comprises glucose.
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6. Method for determining an analyte in a scattering, in particular biological, matrix, in which
in a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, and in an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step, the primary light being focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface, and the region of focus being imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus, wherein light reflected from a defined measuring depth below the interface is detected selectively as secondary light by means of a depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein the primary light is focussed by means of an array of primary light optically focussing elements onto a plurality of regions of focus located at the same depth of focus below the interface and the plurality of the regions of focus is imaged by means of a corresponding number of secondary light optically focussing elements onto respective light entry apertures arranged in the light path to the detector.
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10. Method for determining an analyte in a scattering, in particular biological, matrix, in which
in a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, and in an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step, the primary light being focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface, and the region of focus being imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus, wherein light reflected from a defined measuring depth below the interface is detected selectively as secondary light by means of a depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein at least two detection measurements are made, in which the measuring depth coinciding with the depth of focus is different.
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14. Method for determining an analyte in a scattering, in particular biological, matrix, in which
in a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, and in an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step, the primary light being focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface, and the region of focus being imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus, wherein light reflected from a defined measuring depth below the interface is detected selectively as secondary light by means of a depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein the measuring step comprises providing means for performing a low coherence reflectometric measurement as the depth selection means.
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17. Method for determining an analyte in a scattering, in particular biological, matrix, in which
in a detection step detection measurements are carried out in which light is irradiated through an interface limiting the scattering matrix as primary light into the matrix and light leaving the scattering matrix through the interface is detected by a detector as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix, and in an evaluation step information on the presence of the analyte in the matrix is determined on the basis of a measured value of the measurement quantity measured in the detection step, the primary light being focussed by means of a primary light optically focussing element onto a region of focus lying in the matrix at a depth of focus below the interface, and the region of focus being imaged by means of a secondary light optically focussing element onto a light entry aperture arranged in the light path of the secondary light to the detector, the detection of the secondary light thereby being concentrated on the region of focus, wherein light reflected from a defined measuring depth below the interface is detected selectively as secondary light by means of a depth selection means, the defined measuring depth coinciding with the depth of focus, and wherein the measuring step comprises providing means for irradiating the primary light in a form of a short light pulse and the secondary light is measured within a defined time window, as the depth selection means.
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20. Apparatus for determining an analyte in a scattering matrix, said apparatus comprising:
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a measuring head with a sample contact surface adapted to be placed against an interface of the scattering matrix, light irradiating means with a light transmitter for irradiating primary light into the scattering matrix through the sample contact surface and the interface, detection means with a detector for detecting secondary light leaving the scattering matrix through the interface and the sample contact surface and evaluation means for deriving the information on the presence of the analyte in the matrix from the measuring signal of the detector, in which the irradiation means and the detection means each comprise, an optically focussing element, a primary light optically focussing element of the irradiation means focusses the primary light onto a region of focus lying in the matrix at a depth of focus below the interface, and a secondary light optically focussing element of the detection means images the region of focus onto a light entry aperture arranged in the light path of the secondary light to the detector, whereby the detection of the secondary light is concentrated on the region of focus, wherein an additional depth selection means is provided for selectively detecting light as secondary light reflected from a defined measuring depth, the measuring depth coinciding with the depth of focus, wherein said apparatus performs a detection step wherein detection measurements are carried out in which light is irradiated through the interface as the primary light into the matrix, and the secondary light is detected by the detector leaving the matrix, to determine a measurable physical property of the light which is variable due to interaction of the light with the matrix as a measurement quantity, and an evaluation step wherein information on presence of the analyte in the matrix is determined based upon a measured value of the measurement quantity measured in the detection step, with the primary light being focused by the primary light optically focussing element onto the region of focus lying in the matrix at the depth of focus below the interface, with the region of focus being imaged by the secondary light optical focussing element onto the light entry aperture arranged in the light path of the secondary light to the detector, with the detection of the secondary light being concentrated on the region of focus, and wherein the light reflected from the defined measuring depths below the interface is detected selectively as secondary light by the additional depth selection means, with the defined depth coinciding with the depth of focus. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification