Abstract: A method having the steps of obtaining prepared image data captured by an image sensor receiving light propagated across a sample volume, containing a fluid possibly comprising microscopic objects of foreign origin, while illuminating the sample volume by coherent light. The prepared image data comprising, for a microscopic object, a prepared hologram pattern with prepared spatially alternating intensity formed by the interference fringes; providing filtered image data, comprising automatically filtering the prepared image data by an edge enhancing filter. the filtered image data comprising, for a prepared hologram pattern, a filtered hologram pattern. The presence of the microscopic object associated with the filtered hologram pattern in the sample volume of the fluid is automatically detected on the basis of the filtered hologram pattern.

Abstract: A method (10) utilizes first, second, and third image data originating from first, second, and third digital image frames, respectively, captured sequentially in time of a sample volume containing a fluid possibly comprising moving microscopic objects while illuminating the sample volume by coherent light, each image data comprising, for a moving microscopic object of foreign object present in the sample volume, a hologram pattern (11); and comprises automatically generating first differential image data comprising the difference of the first and the second image data, (13a); automatically generating second differential image data comprising the difference of the second and the third image data (13b); automatically generating product of difference (POD) image data comprising the product of the first and the second differential image data, (14); and automatically detecting the presence of moving microscopic object(s) in the sample volume on the basis of product pattern(s) present in the POD image data (17).

Abstract: A measuring arrangement having an illuminating arrangement to emit coherent light; a cuvette defining an inner volume for receiving a fluid possibly comprising microscopic objects of foreign origin, the cuvette being arranged to receive the coherent light and let it exit therefrom through opposite entrance and exit openings, the entrance opening being closed by an entrance window. The possible microscopic objects present in the fluid scatter part of the light, the scattered and non-scattered light interfering to form interference fringes. An image sensor is configured to capture a hologram digital image frame by receiving the light propagated across the cuvette. An exit window is arranged to close the exit opening of the cuvette. The image sensor is mounted in direct contact with the cuvette.