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JP-7856668-B2 - Method and apparatus for analyzing liquids that may contain a sample.

JP7856668B2JP 7856668 B2JP7856668 B2JP 7856668B2JP-7856668-B2

Inventors

  • ポール カウフマン
  • ダミアン カーク
  • マリオ フラッツル
  • ロマン ゴルベンコフ

Assignees

  • マギア ダイアグノスティクス

Dates

Publication Date
20260511
Application Date
20220221
Priority Date
20210224

Claims (16)

  1. A method for analyzing a liquid that may contain a sample, wherein a sample of the liquid is placed on an analyte area (6e) of an analytical support (6), the analyte area (6e) has a plurality of aspiration zones arranged according to a detection pattern, and the sample is - A magnetic composite comprising the sample and a photoluminescent marker immobilized in the aspiration zone, and/or - The photoluminescent marker that remains dispersed in the liquid , Equipped with, The method comprises the steps of: acquiring a digital image of the analyte region (6e) during exposure time using an imaging device (11) having an optical axis (AO) directed toward the analyte region (6e), wherein the digital image has spatial variations in intensity according to the detection pattern when the sample is present in the sample; - A step of processing the digital image to identify spatial variations in intensity within the digital image, Equipped with, The method is characterized in that for at least a portion of the exposure time, the analytical support (6) is placed in an illumination magnetic field generated by an illumination magnetic source (15), and the illumination magnetic field is parallel to the optical axis (AO) over at least a portion of the area to be analyzed (6e).
  2. The method according to claim 1, wherein the illumination magnetic source (15) is operable to position the analysis support (6) within the illumination magnetic field, and the method further comprises the step of moving the analysis support (6) relative to the illumination magnetic source (15) to selectively position the analysis support (6) inside or outside the illumination magnetic field.
  3. The method according to claim 2, wherein the movement of the analysis support (6) relative to the illumination magnetic source (15) is controlled so as not to change the direction of the illumination magnetic field in the analysis target region (6e) or to reverse the orientation of the illumination magnetic field during the movement.
  4. The method according to claim 2, wherein the movement of the analytical support (6) relative to the illumination magnetic source (15) is controlled such that the orientation of the illumination magnetic field produces at least one complete rotation.
  5. The method according to any one of claims 1 to 4, wherein the acquisition step comprises multiple exposure periods for establishing multiple digital images, and the method comprises a positioning step in which the relative position of the illumination magnetic source (15) with respect to the analysis support (6) is corrected between two exposure periods.
  6. The analytical method according to any one of claims 1 to 5, further comprising the step of aspirating the magnetic composite optionally present in the sample to fix the magnetic composite in the aspiration zone, prior to the acquisition step.
  7. The analytical method according to claim 6, wherein the suction step comprises exposing the analytical support (6) to a magnetic field provided by the illumination magnetic source (15).
  8. The analytical method according to claim 6, wherein the suction step comprises exposing the analytical support (6) to a magnetic attraction field generated by a magnetic attraction source (18) different from the illumination magnetic source (15).
  9. The analytical method according to claim 8, wherein the attraction magnetic field and the illumination magnetic field have the same direction and orientation in the area to be analyzed (6e).
  10. The analytical support (6) comprises a magnetic layer (6b) that defines at least a portion of the aspiration zone and a non-magnetic surface film (6c) disposed on the magnetic layer (6b), wherein the magnetic layer (6b) defines the area to be analyzed (6e), according to any one of claims 1 to 9.
  11. Analytical device (E), A host support for receiving an analysis target area (6e) of an analysis support (6) and a plurality of suction zones arranged on the analysis target area (6e) according to a detection pattern , and for positioning them at the acquisition location, An imaging device (11) having an optical axis (AO) and depth of field, and positioned so as to receive the area to be analyzed (6e) within its depth of field when the analysis support (6) is in the acquisition position, An illumination magnetic source (15) capable of generating an illumination magnetic field to which the analysis support (6) is exposed when it is in the acquisition position, wherein the illumination magnetic field is parallel to the optical axis (AO) over at least a portion of the analysis target area (6e), An analytical device (E) equipped with the following features.
  12. The analytical apparatus (E) according to claim 11, wherein the imaging device (11) is located on one side of the host support, and the illumination magnetic source (15) is located on the other side of the host support.
  13. The analytical apparatus (E) according to claim 11 or 12, wherein the illumination magnetic source (15) is selectively movable to position the host support within the illumination magnetic field or outside the illumination magnetic field.
  14. The analytical apparatus (E) according to any one of claims 11 to 13, comprising a separate magnetic attraction source (18) from the illumination magnetic source (15) for generating an attractive magnetic field.
  15. The analytical apparatus (E) according to claim 14, further comprising a transport rail (17) for moving the analytical support (6) from an incubation position where it can receive the attractive magnetic field generated by the attractive magnetic source (18) to the acquisition position where it can receive the illumination magnetic field generated by the illumination magnetic source (15).
  16. The apparatus (E) further comprises an analytical support (6) disposed on the host support, the analytical support (6) comprising a magnetic layer (6b) that at least partially defines the aspiration zone and a non-magnetic surface film (6c) disposed on the magnetic layer (6b), the magnetic layer (6b) defining the area to be analyzed (6e), according to any one of claims 11 to 15.

Description

The technical field of the present invention is the field of biological analysis for detecting the presence and/or concentration of a sample in liquid samples, particularly biological fluid samples. More specifically, the present invention relates to a method for detecting the presence and/or concentration (more simply, “analysis”) of a sample in a biological fluid sample. This method may be implemented in a “point-of-care” type portable analyzer, that is, enabling the test to be performed and interpreted in situ, i.e., at the patient’s bedside rather than in a central laboratory, to make immediate clinical decisions. The device performs the analysis on a sample collected on an analytical support such as a microfluidic cartridge. European Patent No. 3447492 discloses a method for capturing and detecting species, often referred to as “specimens,” in liquid samples, particularly biological fluid samples. The principle for capturing and detecting patterns carried out by this method is also described in the paper “Magnetophoretic induced convective capture of highly difficult superparamagnetic nanoparticles” by Fratzl et al., Soft Matter, 14.10.1039/C7SM02324C. These methods are also described in the literature by Delshadi S et al., “Rapid immunoassay exploring nanoparticles and micromagnets: proof-of-concept using ovalbumin model,” Bioanalysis. March 2017; 9(6): 517–526. According to this method, a sample is mixed with nanometer-sized or more commonly submicrometer-sized magnetic particles, each bound to a capture element capable of binding to the species whose presence is to be detected or quantified. The species to be detected, i.e., the sample, may be an antigen, and the elements may be antibodies, or vice versa. A detection element, such as a photoluminescent marker, or a detection antibody or antigen supported by a fluorescent marker, is also introduced into the sample. By the end of this step, a complex is formed in the solution from the capture element, sample, and detection element, which is then immobilized on a support containing a magnetic microsource aligned according to a specific spatial pattern. This pattern is defined by strong and weak magnetic field zones that induce significant magnetic field gradients. The complex, bound by magnetic particles, tends to aggregate on the support in the zone where the magnetic field norm is maximum. Photoluminescent (particularly fluorescent) markers can reveal a specific spatial pattern that marks the presence of the sample in the solution. The average (spatial) intensity of this optical pattern is typically referred to as the "specific signal." In most cases, especially when the sample is absent or present in only a limited amount, the unbound detection elements displaying the photoluminescent marker remain dispersed in the suspension in solution. These contribute to the formation of a relatively homogeneous light background. The average (spatial) intensity of this light background forms a signal called the "supernatant signal." In addition to the unbound photoluminescent markers, this light background is also formed by the intensity of light emitted by all the photoluminescent materials in the sample. Capture elements, unbound to the sample and detection elements, are also immobilized on the support, but these capture elements do not carry markers and therefore do not contribute to the light pattern or light background. The spatial arrangement of magnetic field microsources on the plane of the support and the light intensity of the pattern exposed by the photoluminescent marker allow for the detection and quantification of the sample in the specimen without washing, i.e., without removing the liquid solution after fixing the composite on the surface of the support, which is particularly advantageous. To enable this detection, the surface of the sample and support are illuminated to allow detection of the photoluminescent marker, and a digital image is acquired. Therefore, this digital image has a spatially variable intensity (within the plane of the image) depending on the strength of the magnetic field generated by the support. By processing the image, it is possible to identify this spatial variation, determine the specific signal and the supernatant signal, and conclude that the sample is present in the specimen or estimate its concentration based on the specific signal/supernatant signal ratio. Traditionally, this type of analysis has been performed in a central laboratory. However, the simplicity of the approach described above, particularly the absence of cleaning, allows for integration into autonomous, portable, or mobile immunoanalytical analyzers at the patient's bedside, without the need for pumps or valves. Typically, the detection limit of the sample in the sample is required to be as low as possible. This leads to processing low-contrast images, which must be highly sensitive (to avoid false negatives, i.e., to conclude that the sample is not