Device for determining information relating to element of bodily fluid and method for determining such information

Abstract

An apparatus and method of determining information related to particles, such as cells, in a liquid in which images are generated at different focus lengths / depths and at different points in time. From the image, particle movement of a plurality of different cells, bacteria, platelets, etc. over time is determined and their density and / or type is determined therefrom.

Description

Technical Field

[0001] The method relates to a device for determining information related to elements of a body fluid and a method for determining the information, in particular for determining information related to more or less solid elements (such as cells, bacteria, etc.) in a body fluid. Background Art

[0002] Historically, cell identification or sorting has been performed visually by human operators or experts. Other techniques, such as DNA staining, have also been used.

[0003] Image-based cell identification is a well-known technique, and the density of individual cell types is known.

[0004] Related technologies can be found in:

[0005] - BERNHARDT I et al.: "Study of the sedimentation of intact erythrocytes and their interaction with artificial surfaces using digital holographic microscopy", Bioelectrochemistry, ELESEVIER, Amsterdam, The Netherlands, Vol. 73, No. 2, August 1, 2008 (2008-08-01), pp. 92-96, XP023784160, ISSN: 1567-5394, DOI: 10.1016 / J.BIOELECHEM.2007.12.001

[0006] - Yu Xiaoao et al.: "A Review of Digital Holographic Microscopy for 3D Profiling and Tracking", Optical Engineering, Society of Optical Instrumentation Engineers, Bellingham, Vol. 53, No. 11, November 1, 2014 (2014-11-01), p. 112306, XP060048121, ISSN: 0091-3286, DOI: 10.1117 / 1.0E.53.11.112306

[0007] - SANG-HYUK LEE et al.: “Characterization and Tracking of Single Colloidal Particles Using Video Holographic Microscopy,” arxiv.org, Cornell University Library, 201 OLIN Library Cornell University, Ithaca, NY 14853, December 11, 2007 (2007-12-11), XP080 345670. Summary of the invention

[0008] In a first aspect, the invention relates to a device according to claim 1 .

[0009] In this case, the elements of the device may be attached to each other, or may simply be appropriately positioned relative to each other.

[0010] The body fluid may be, for example, blood, saliva, milk and / or urine, and the elements therein may be cells, such as blood cells, such as white blood cells WBC, red blood cells RBC and pathological cells (such as circulating tumor cells CTC, nucleated red blood cells nRBC, etc.), epithelial cells, platelets, bacteria, parasites, proteins or other components of the body fluid.

[0011] A sample container is provided and configured to contain a sample of a body fluid containing an element. The sample container can be of any desired type. Typically, the sample container includes or is made of a translucent material that allows light or radiation to pass through the sample and the sample container so that the imaging element provides imaging information. When containing the sample, the sample container can allow the sample to have a predetermined or minimum height in a vertical direction, thereby allowing cells present in the sample to move in a vertical direction, such as moving a predetermined distance, without hitting the sample container.

[0012] The sample can be an untreated and unfiltered body fluid, or the sample can contain only a portion of the body fluid, such as if the body fluid has been filtered or otherwise prepared, such as by removing elements (e.g., red blood cells) therefrom. The sample can be prepared by adding one or more reagents to the body fluid that are configured to change one or more parameters or components of the body fluid. For example, a lysing agent can be used to filter or lyse red blood cells.

[0013] The sample may be a collected sample of a body fluid comprising elements having related properties, wherein the related properties substantially correspond to the related properties of the elements in the body fluid before collection. The sample may be a body fluid sample in which cells of a particular type are removed or lysed. The sample may be a diluted body fluid sample. An imaging element is provided that is configured to generate a sequence of imaging information over time. Thus, the imaging element may be appropriately positioned at or around the sample container. The sample container and the imaging element may be adapted to each other so as to output the desired imaging information.

[0014] An imaging element is provided to generate a sequence of imaging information. Thus, a plurality of imaging information is provided, and each imaging information is generated at a separate time point. The imaging information may be generated at equidistant time points, for example, every second, every 2 seconds, every 4 seconds, every 5 seconds, every 10 seconds, every 15 seconds, or every 20 seconds.

[0015] Each imaging information includes information representing images of the sample in the sample container and at least two different focal lengths / depths. Therefore, each imaging information itself may include multiple images, each image having a specific or different focal length / depth. Then, the imaging information will be provided over a period of time, wherein the time periods of different imaging information are preferably non-overlapping, so that multiple imaging information are obtained over time. Alternatively, it may be desirable to provide all represented images (images representing a specific focal length / depth in each imaging information) at different time points, so that images of representations of other depths can be provided at different time points.

[0016] Imaging information includes information representing images of the sample at at least two different focal lengths / depths. This information can be provided by an actual image obtained using an optical device that provides the desired focal depth / length. In another case, the information can be contained in the form of a hologram. Information can be obtained from the hologram, which represents an image focused and photographed on a desired plane (usually a horizontal plane) so that the plane has a height / depth. This information will be similar to an image taken with a desired focal depth / length, in which not only elements at or in a specific plane or depth / length are visible, but also other elements may exist. However, elements in or at a plane are clearer, which can be used to determine which elements exist at the depth / length. The represented image may alternatively be similar to a sample or a cross section of a sample.

[0017] In the different imaging information, each of the plurality of elements is identified and their position is determined. Thus, the positions of these elements are tracked or determined in the different imaging information and thus determined over time. Thus, from any movement thereof, the type or other parameters of each element can be determined. Naturally, the plurality of elements can be more than one element, such as all elements discernible in the imaging information, but typically, the plurality of elements counts 5-1000 elements, such as 10-500 elements, such as 15-100 elements.

[0018] Thus, from the information representing the image, it can be determined which elements are present in or at the depth / length in question.

[0019] In one embodiment, variable optics or sets of fixed optics are used to generate imaging information such that different focal lengths / depths can be obtained using such optics.

[0020] In some embodiments, a hologram of a sample can be recorded. From a single hologram, an image or representation with any focal length / depth can be generated. Any number of such images or representations can be generated for any number of focal lengths / depths in the sample. Thus, a sequence of holograms can be recorded, each being independent imaging information, and then individual information representing each focal length / depth can be generated from the hologram.

[0021] A controller is provided. The controller may be hardwired or software controlled and may be, for example, a processor, DSP, ASIC, FPGA, etc. The controller may be composed of multiple elements that communicate with each other.

[0022] The controller is configured to receive the sequence of imaging information. The controller can thus communicate with the imaging element. This communication can be wired or wireless and can be carried out through any protocol or bus or even the WWW. If desired, the controller can be provided as a cloud service.

[0023] The controller is configured to identify the same element in different imaging information acquired at different time points. This determination can be based on multiple parameters and imaging information of the sample. In a preferred embodiment, it is assumed that the element moves along a vertical path, thereby assuming that the element is always at a specific position in the horizontal plane. It can be further assumed that the element is moving downward, thereby additionally assuming that the position of the element is at a greater depth at a later time point. Alternatively, or additionally, another parameter of the element, such as shape, contour, edge, color, reflection, emission, fluorescence or internal content, can be used to identify the same element in different imaging information. The cell can have a nucleus or other elements with a specific shape, position or number, which can be used to distinguish cells.

[0024] For example, if the sample is allowed to move horizontally, or is found to move horizontally, the vertical movement can be added to the horizontal movement. This horizontal movement can then be compensated for if necessary.

[0025] The controller is also configured to determine the position of the element in the sample container for each imaging information.As described above, over time and therefore between imaging information, the position of the same element may shift vertically, horizontally, or may move in another way in the sample.

[0026] The controller is configured to determine information related to the element from the position. The information may be density or relative density compared to the density of the liquid of the sample. The controller may be configured to determine this information also based on the time difference between the imaging information. From the change in position, such as depth, and the time period between the detection of these positions, the speed of movement can be determined. The speed will indicate the density difference between the liquid of the sample and the liquid of the element. The speed may additionally or alternatively indicate which type the element is, such as which type of white blood cell the element is.

[0027] In another case, the controller may additionally or alternatively determine the size of the element. An element may sink (or float) at a speed determined by or indicative of its size, such as a cross-sectional area in a vertical plane.

[0028] In a preferred embodiment, the imaging information is a hologram. The imaging element is then configured to generate a hologram or a sequence of holograms. Such an imaging element typically has a radiation or light emitter and a detector, typically in the form of a 2D detector array, such as a CMOS sensor, a CCD array, etc. Different setups can be used, such as on-axis (coaxial) and off-axis holographic setups, the latter of which uses a tilted reference beam in order to separate the twin image from the real object in Fourier space. In addition, or alternatively, multiple cameras can be used to capture images or data at different wavelengths, from which more information can be determined from the sample. In one case, the radiation is emitted through a pinhole and passes through the sample before hitting the detector.

[0029] When the imaging information is a hologram, there are methods to derive information from the hologram, typically in the form of a 2D image or representation of the sample, where these representations indicate not only the elements present at a particular length / depth, but also other elements. From this information, it is possible to determine which elements are present at a particular length / depth. These methods can be direct methods, such as angular spectrum backpropagation or intensity transfer, iterative methods, such as Gerchberg-Saxton or sparse regularized reconstruction, and / or machine learning techniques, such as UNet, GAN, and deep image prior methods, with varying levels of reconstruction accuracy.

[0030] In alternative embodiments, the imaging information is generated by a more standard imager, such as a camera, with adaptable optics or sets of fixed optics so that images with different depths / lengths of focus can be provided.

[0031] In one embodiment, when the imaging information is a hologram, the controller is configured to:

[0032] After the receiving step, an image representation of the sample is obtained from each hologram, wherein each image representation is associated with a separate focal length / depth of the at least two different focal lengths / depths,

[0033] In the identifying step, each of a plurality of elements in at least two image representations associated with two different holograms and two different focal depths / lengths are identified.

[0034] Typically, as described above, the same element is determined at different points in time and at different lengths / depths. Information can be derived from this.

[0035] In one embodiment, the controller is configured to determine the absolute density of the relevant element or the density relative to the sample liquid as information related to at least one of the multiple elements and determine the absolute density of the relevant element or the density relative to the sample liquid from the position of the one element.

[0036] In this embodiment, the controller can be configured to determine the density of the element of interest based on the difference in focal length / height of the locations. Such a difference would indicate vertical movement that may be caused by gravity and density differences between the element and the sample liquid.

[0037] In one embodiment, the element is a cell, such as a red blood cell, a white blood cell, a circulating tumor cell, or a bacterium. In that or other embodiments, the element may be a crystalline material, a parasite, or a bacterium. Alternatively, the element may be a parasite or a platelet. Cells are usually heavy enough and / or have a size that allows them to move predictably, evenly, or generally in a downward direction, while platelets may be so small that they tend to remain suspended. Bacteria and especially parasites may be able to move by themselves, so their position in the sample may not only be vertical. When a parasite moves far enough horizontally or even upwards, it can be determined. If the sample is in a stationary state in the sample container, horizontal movement is most easily determined.

[0038] Note that Brownian motion can also be determined from the imaging information, for example from the horizontal movement of, for example, platelets or any impurity that is lighter than a cell, and therefore does not tend to settle in the sample. Such motion can be used to derive, for example, the temperature of the sample. Furthermore, any movement of these elements can be used to indicate that the sample is moving, if, for example, these elements are consistently detected for many or all of these elements. This can be used to compensate for any movement determined by other elements, or to discard this determination.

[0039] Then, in one embodiment, the position of one of the plurality of elements over time indicates random movement, and wherein information associated with the one element indicates that the element is a platelet.

[0040] In this or another embodiment, the position of one of the plurality of elements indicates upward or sideways movement for at least a predetermined minimum time period, and wherein the information associated with the one element indicates that the element is a parasite or bacteria. Naturally, the predetermined minimum time period will be long enough to exclude random movement, such as that caused by Brownian motion. The time period may be 1 second or longer, such as 2 seconds or longer.

[0041] In such embodiments or in separate embodiments, the position of one of the plurality of elements over time indicates generally downward movement at a decreasing rate within a first velocity interval, and wherein the information associated with the one element indicates that the element is a cell.

[0042] Furthermore, additionally or alternatively, the position of one of the plurality of elements over time indicates generally downward movement at a decreasing rate within a second velocity interval, and wherein the information associated with the one element indicates that the element is bacteria. The rate of decrease of cells and bacteria may be determined based on testing.

[0043] It may be desirable to determine information based on additional information. In addition to different densities or sizes, any internal structure thereof, the structure of its edges or the shape may also be used.

[0044] In one embodiment, the controller is configured to determine edge information related to the edge of the element in the one or more image representations, and further determine information related to the element based on the edge information. The edge of the white blood cell is called the cell wall and is different between white blood cell types, and this information can be used to determine.

[0045] A second aspect of the invention relates to a method according to claim 8 .

[0046] All embodiments, considerations, situations etc. of the first aspect of the present invention are also relevant to the second aspect of the present invention.

[0047] Thus, the sample, the fluid, the element, the sample container, the imaging element, the imaging information and the information representing the image may be as described above.

[0048] Furthermore, identification of elements and determination of information may be as described above.

[0049] As also described above, in a preferred embodiment, the generating step comprises generating a sequence of holograms. In this case, the method may further comprise deriving at least two image representations from each hologram, each image representation being associated with a separate focal length / depth of the at least two different focal lengths / depths, and wherein the identifying step comprises identifying each of a plurality of elements in the at least two image representations associated with two different holograms and two different focal depths / lengths.

[0050] In one embodiment, the determining step includes determining the density of the element of interest as information related to at least one of the plurality of elements. The density and determination are as described above. The determining step may then include determining the density of the element of interest based on a difference in focal length / depth of position.

[0051] In one embodiment, the elements of the sample are cells or bacteria. However, platelets, parasites, crystalline materials, and other types of elements may also be sought and analyzed.

[0052] As described above, Brownian motion may be determined and used to validate measurements and / or to correct determined movements.

[0053] As described above, in one embodiment, the position of one of the plurality of elements over time indicates random movement, and wherein information associated with the one element indicates that the element is a platelet.

[0054] In this or another embodiment, the position of one of the plurality of elements indicates upward movement for at least a predetermined minimum time period, and wherein the information associated with the one element indicates that the element is a parasite or bacteria. The time period is further described above.

[0055] In any of these embodiments or in a separate embodiment, the position of one of the plurality of elements over time indicates a generally downward movement at a decreasing rate within a first velocity interval, and wherein the information associated with the one element indicates that the element is a cell.

[0056] Additionally or alternatively, the position of one of the plurality of elements over time indicates a generally downward movement at a decreasing rate within the second velocity interval, and wherein the information associated with the one element indicates that the element is bacteria.

[0057] In one embodiment, the determining step further comprises determining edge information associated with edges of elements in the one or more image representations, and further determining the information associated with the elements based on the edge information.

[0058] Another aspect of the present invention is based on the same relative movement and density, but is intended to determine the parameters of a fluid. This aspect relates to a device for determining information related to a body fluid, such as blood, serum, saliva, urine, etc., the device comprising:

[0059] a sample container configured to receive a sample comprising a fluid and one or more particles having one or more predetermined parameters,

[0060] an imaging element configured to generate a sequence of imaging information over time, each imaging information comprising information representing an image of a sample in a sample container and at at least two different focal lengths / depths,

[0061] A controller configured to:

[0062] A sequence of receiving imaging information,

[0063] identifying the same element in different imaging information and determining the position of the element in the sample container for each imaging information, and

[0064] Information related to the fluid is determined from the location.

[0065] In this case too, the movement of the particles is determined and used to generate information. This time, the unknown component is a liquid.

[0066] Obviously, as mentioned above, the positions of multiple elements can be determined in different imaging information.

[0067] The liquids, measuring assembly, sample container, controller and all other parameters, implementations, circumstances etc. may be as described above.

[0068] If desired, the sample may be a filtered or other sample from a body fluid. Likewise, other fluids may be analyzed in this manner. Preferably, the particles are visible in the fluid so that the fluid is not too turbid, for example when it is translucent at least at one or more wavelengths used by the measurement assembly. The liquid may include other elements if desired.

[0069] Particles have one or more predetermined or predefined parameters, such as density and / or size. As mentioned above, the relative density and optional size of the particles will help determine the vertical velocity of the particles. Therefore, knowing the parameters of the elements or particles, information can be obtained from the fluid.

[0070] A final aspect of the invention relates to a method of determining information related to a fluid, the method comprising:

[0071] providing a sample in a sample container, the sample comprising a fluid and an element having predetermined parameters,

[0072] generating a sequence of imaging information over time, each imaging information comprising information representing an image of a sample in a sample container and at at least two different focal lengths / depths,

[0073] identifying the same element in different imaging information and determining the location of the element in the sample container for each imaging information, and

[0074] From this location, information related to the fluid is determined.

[0075] This then also involves the determination of information related to the fluid.The same considerations as described above are relevant to this aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Below, the preferred embodiment is described with reference to the accompanying drawings, in which:

[0077] Figure 1 A first preferred embodiment of a device using a holographic imager is shown,

[0078] Figure 2a and 2b shows the sedimentation of cell-like beads in the sample,

[0079] Figure 3 shows the density of typical blood cells,

[0080] Figure 4 An alternative embodiment of an apparatus employing adaptive optics is shown, and

[0081] Figure 5 An alternative embodiment of a device employing interchangeable optics is shown. DETAILED DESCRIPTION

[0082] exist Figure 1 , a preferred embodiment of the device 10 is shown, wherein the sample holder 20 holds a sample from a body fluid, the sample comprising elements of the body fluid, such as cells, bacteria, platelets, parasites, etc. The sample may be a processed body fluid, such as a sample in which components or constituents of the body fluid have been removed or altered, such as blood with lysed red blood cells, milk with dissolved fat, etc.

[0083] An image information provider 30 is provided in the form of a holographic imager, which is configured to provide a hologram of the sample or a portion thereof. In this embodiment, the image provider includes a light source 24 such as an LED, a pinhole 28, and light is delivered to the sample holder 20 through the pinhole 28. A detector or imager 24 is provided, such as a detector array, such as a CMOS array, for receiving light that penetrates the pinhole and the sample having the element. Alternatives to LEDs and pinholes can be lasers or light sources of different configurations, such as concentric circles of LEDs. In addition, it may be advantageous to perform wavefront modulation on the light source, such as by an SLM or DOE.

[0084] A controller 40 is provided for receiving the output of the imager 24 to obtain a plurality of images or information representing images of the sample at different focal planes or depths.

[0085] This generation of images or information can be found in Dharmawan, Mariana, Scholz, Schulze, Triyana, See Rustenbeck, Hiller, Wasisto, and Waag, "Non-mechanical parfocality and autofocusing features based on wave propagation distribution in lensless holographic microscopy," Scientific Reports, (2021) 11: 3213. Note that when determining an image or information based on a hologram, all such images or information are obtained at the same point in time.

[0086] The image information provider outputs a sequence of holograms over time, and then the controller generates a sequence of sets of images or information from the sequence of holograms.

[0087] When holograms are provided for the same sample over time, preferably while the sample is generally stationary, many different types of information can be derived from the sample.

[0088] When different focal depths or lengths are shifted in a generally vertical direction, the density of an element of a sample can be determined from determining the element (e.g., a cell) at increasing or decreasing depths at increasing points in time. When the density of the liquid portion of the sample is known, the sedimentation or floating velocity of the element can be used to determine the density of the element.

[0089] Whether an element (eg, a cell) is present at the depth of a particular image or information can be determined from the sharpness of the edges or components (eg, a cell nucleus) of the cell.

[0090] In the applicant's co-pending application EP22182762.9 filed on July 4, 2022, a technique is shown by which it is possible to determine not only whether a cell or other element is in the focal plane of the image, but also whether the element is closer or further away from the imager. Thus, this technique can alternatively or additionally be used to determine the depth at which the image element was seen at the point in time when the relevant hologram was recorded.

[0091] The position of an element 25 such as a cell in the sample can be determined as coordinates in a horizontal plane and a depth. The cell can then be identified in a later hologram and at another, usually greater depth, by at least substantially the same coordinates in the horizontal plane but at another depth.

[0092] exist Figure 1 In FIG. 2 , one particle 25 is above the plane 27 defining the depth, one is in the plane, and two are below the plane.

[0093] Figure 2a and 2bShown is a measurement of a fluid where beads with a diameter of 10 μm and a density of 1.055 g / ml were immersed in deionized water (1.0 g / ml). Since the density of the beads is slightly higher than that of the liquid, they will settle, appearing at greater and greater depths over time. Figure 2a In the example above, the depth of 25 beads can be seen changing over time when examined over 140 seconds. Figure 2b The sinking of individual beads can be seen in the figure, along with a linear fit of the downward velocity of each bead.

[0094] Figure 3 Shows the density of different types of blood cells. Figure 3 It can be seen that different cell types have different sedimentation rates due to their different densities. These different rates can be used to characterize or identify cell types.

[0095] In addition, other information may be used to characterize the elements, such as visual elements, such as the shape, outline, color, etc. of the various parts of the element (e.g., the cell membrane, the cell nucleus, or other components thereof). Different white blood cells have membranes and nuclei of different sizes and shapes, as well as different "fluffiness". These parameters may be determined from the image / information and used to characterize the various elements.

[0096] Obviously, elements with a density lower than that of the liquid will move upwards in the sample. The upward velocity can be used in the same way to characterize the element and / or obtain information about it.

[0097] Additionally, horizontal movement may be determined, wherein elements are identified at at least substantially the same depth over time.

[0098] Horizontal movement can be caused by, for example, Brownian motion, whereby elements with approximately the same density as the liquid, and / or elements of such small size that they can only settle or float very slowly, will move more or less randomly, and therefore also vertically. Thus, from the movement of these elements, the magnitude of the Brownian motion can be determined, and this can be used to compensate for the density or velocity determination of heavier / lighter / larger elements.

[0099] Such small elements of the sample may be platelets, larger aggregates of platelets, bacteria and impurities, such as unintended parts of the sample, such as colored crystals from sample preparation.

[0100] It may also be desirable to determine non-Brownian motion of particles, such as convection of nearby bubbles. This can also be used as an indication that the sample is not stationary and the measurement is flawed. Furthermore, if a plurality (e.g. all) of the determined elements move in unison or have a moving component, this consistent movement can be used as an indication that the sample in the sample container is not stationary. The movement of the individual elements can then be compensated for this consistent motion, or the analysis can be stopped until a later point in time when the sample is assumed to be stationary.

[0101] Additionally, parasites may be present in body fluids. Some parasites and some bacteria are able to move on their own in body fluids. The parasite / bacteria can then be characterized or identified when determined at different depths, such as when moving up and down, and when moving in a horizontal plane, such as beyond any movement that may be caused by Brownian motion.

[0102] exist Figure 4 , an alternative embodiment of apparatus 80 can be seen in which a sample in a sample container is imaged using an imager 90 having adaptable optics, such as a variable lens, for providing a sequence of images having different focal lengths or depths for the same sample. By rapidly changing the optics, a sequence of images having different focal depths can be provided, assuming that the position of the sample elements has not moved significantly. Notably, the above information related to the depth / position and time of the elements can be determined when imaging different depths of the same sample at different time points. These time points can be recorded and used to determine information related to the elements of the sample.

[0103] exist Figure 5 In FIG. 1 , another alternative 100 can be seen, in which the imager 90 ′ has replaceable lenses 92, each of which is fixed at a specific focal depth. Thus, the lenses 92 are sequentially brought into the optical path between the sample container and the imager 90 ′, so that a sequence of images can again be provided for the same sample and at different focal depths.

[0104] As mentioned above, the drawings and description relate to the determination of particle parameters in a liquid, whose (one or more) relevant parameters are preferably known. When the parameters of the particle are known, the same configuration can be used to determine the (one or more) parameters of the liquid. Therefore, when the particle is known, its upward / downward movement determined as described above can be used to determine the parameters of the liquid.

[0105] In this case, as also described above, the liquid may be a bodily fluid, such as a filtered or otherwise processed bodily fluid.

Claims

1. A device for determining information related to an element of a body fluid, the device comprising: a sample container configured to receive a sample containing an element of said body fluid, an imaging element configured to generate over time a sequence of imaging information, each imaging information comprising information representing an image of the sample in the sample container at at least two different focal lengths / depths, A controller configured to: A sequence of receiving imaging information, identifying each of a plurality of elements in different imaging information and determining a position of each of the plurality of elements in the sample container for each imaging information, and Information associated with each of the plurality of elements is determined from the location.

2. The device according to claim 1, wherein: The imaging information is a hologram.

3. The device according to claim 2, wherein: The controller is configured to: After the receiving step, an image representation of the sample is derived from each hologram, wherein each image representation is associated with a separate focal length / depth of the at least two different focal lengths / depths, In the identifying step, each of the plurality of elements in at least two image representations associated with two different holograms and two different focal depths / lengths is identified.

4. A device according to any one of the preceding claims, wherein: The controller is configured to determine the density of the related elements as information related to at least one element of the plurality of elements and from a position of the one element.

5. The device according to claim 4, wherein: The controller is configured to determine the density of the associated elements based on differences in focal lengths / heights of the locations.

6. The device of any of the preceding claims, wherein each of the plurality of elements is a cell, a platelet, a crystalline material, a parasite or a bacterium.

7. A device according to any one of the preceding claims, wherein: The controller is configured to determine edge information associated with an edge of at least one of the plurality of elements in one or more image representations, and further determine information associated with the one element based on the edge information.

8. A method of determining information related to an element of a body fluid, the method comprising: providing a sample in a sample container, said sample comprising elements of said body fluid, generating a sequence of imaging information over time, each imaging information comprising information representing an image of the sample in the sample container and at at least two different focal lengths / depths, identifying each of a plurality of elements in different imaging information and determining a position of each of the plurality of elements in the sample container for each imaging information, and Information associated with each of the plurality of elements is determined from the location.

9. The method of claim 8, wherein the generating step comprises generating a sequence of holograms.

10. The method of claim 9 further comprising deriving at least two image representations from each hologram, each image representation being associated with a separate focal length / depth of the at least two different focal lengths / depths, and wherein the identifying step comprises identifying each of the plurality of elements in the at least two image representations associated with two different holograms and two different focal depths / lengths.

11. The method according to any one of claims 8 to 10, wherein the determining step comprises determining a density of the relevant element as information related to at least one element of the plurality of elements.

12. The method of claim 11, wherein the determining step comprises determining the density of the relevant elements based on differences in focal length / depth of the locations.

13. The method of any one of claims 9-12, wherein each of the plurality of elements is a cell, a platelet, a crystalline material, a parasite, or a bacterium.

14. The method according to any one of claims 8-13, wherein the determining step further comprises determining edge information related to edges of the element in one or more image representations, and further determining information related to the element based on the edge information.

Images