Evaluating assays with optical inhomogeneities

A sensor device for performing and evaluating an assay with a sample, comprising:

• a carrier with a sensing surface that can be contacted by the sample;
• an optical sensor unit for making optical measurements at the sensing surface, the optical sensor unit comprising an image sensor by which a homogeneity-image of the sensing surface can be generated, the homogeneity-image including a plurality of pixels, each pixel having an image value;
• and
• an evaluation unit coupled to the optical sensor unit, the evaluation unit comprising digital data processing-hardware executing software to:
• determine whether image values of pixels within at least one region of interest in the homogeneity-image of the sensing surface deviate from a given target range of image values, wherein homogeneity is based on image values of the pixels falling within the given target range and inhomogeneity is based on the image values deviating from the given target range;
• reject the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating inhomogeneity;
• and
• accept the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating homogeneity;
• wherein the image sensor is configured to generate a plurality of homogeneity-images at different times of the assay.

A sensor device for performing and evaluating an assay with a sample, comprising:

• a carrier with a sensing surface that can be contacted by the sample;
• an optical sensor unit for making optical measurements at the sensing surface, the optical sensor unit comprising an image sensor by which a homogeneity-image of the sensing surface can be generated, the homogeneity-image including a plurality of pixels, each pixel having an image value;
• and
• an evaluation unit coupled to the optical sensor unit, the evaluation unit comprising a data carrier and digital data processing-hardware executing software stored on the data carrier to:
• determine whether image values of pixels within at least one region of interest in the homogeneity-image of the sensing surface deviate from a given target range of image values, wherein homogeneity is based on image values of the pixels falling within the given target range and inhomogeneity is based on the image values deviating from the given target range;
• reject the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating inhomogeneity;
• and
• accept the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating homogeneity;
• wherein the digital data processing-hardware further executes software to store as data on the data carrier a shape and a location of an indicated inhomogeneity present on the sensor surface via the homogeneity-image for subsequent comparison with a successively generated homogeneity-image to determine whether servicing, cleaning, or replacing of the sensor device is required.

A sensor device for performing and evaluating an assay with a sample, comprising:

• a carrier with a sensing surface that can be contacted by the sample;
• an optical sensor unit for making optical measurements at the sensing surface, the optical sensor unit comprising an image sensor by which a homogeneity-image of the sensing surface can be generated, the homogeneity-image including a plurality of pixels, each pixel having an image value;
• and
• an evaluation unit coupled to the optical sensor unit, the evaluation unit comprising digital data processing-hardware executing software to:
• determine whether image values of pixels within at least one region of interest in the homogeneity-image of the sensing surface indicate homogeneity or inhomogeneity based on a given target range of image values;
• reject the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating inhomogeneity;
• and
• accept the optical measurements provided by the optical sensor unit for the at least one region of interest in response to the image values of pixels within the at least one region of interest indicating homogeneity;
• wherein the digital data processing-hardware further executes software to determine whether the image values of pixels within at least one region of interest in the homogeneity-image of the sensing surface indicate homogeneity or inhomogeneity by subtractively combining the homogeneity-image with a reference image of the at least one region of interest to generate a difference image and by comparing pixel values of the difference image to the given target range.