Abstract: The invention describes an iterative reconstructing method allowing a spatial distribution of fluorescence in an object to be obtained. The method comprises acquiring images of fluorescence in various planes at various depths in the object, so as to form a three-dimensional acquired image. It comprises an iterative reconstructing algorithm with, in each iteration, an initial fluorescence distribution or a fluorescence distribution resulting from a preceding iteration being taken into account, and the fluorescence light wave propagating through the object being simulated, so as to obtain a reconstruction of the acquired image. The acquired image, or a differential image corresponding to a comparison between the acquired image and the reconstructed image, is then back-propagated through the object, so as to update the fluorescence distribution. FIG. 5B.

Abstract: A method for determining a state of a cell, the cell being placed in a sample, in contact with a culture medium, the method comprising: illuminating the sample with a light source and acquiring an image of the sample with an image sensor, the image sensor lying in a detection plane; from the acquired image, locating a position of the cell in a plane parallel to the detection plane; the method further comprising: from the acquired image, estimating a refractive index of the cell or a relative refractive index of the cell, the relative refractive index corresponding to a refractive index of the cell relative to the refractive index of the culture medium; from the estimation of the refractive index or of the relative refractive index, determining an index of interest of the cell; from the index of interest, classifying a state of the cell among predetermined states, the predetermined states comprising at least one apoptosis state and one living state.

Abstract: A method for observing a sample (10), the sample lying in a plane of the sample defining radial coordinates, the method comprising the following steps: a) illuminating the sample using a light source (11), able to emit an incident light wave (12) that propagates toward the sample along a propagation axis (Z); b) acquiring, using an image sensor (16), an image (I0) of the sample (10), said image being formed in a detection plane (P0), the sample being placed between the light source (11) and the image sensor (16), such that the incident light wave sees an optical path difference, parallel to the propagation axis (Z), by passing through the sample; c) processing the image acquired by the image sensor; wherein the processing of the acquired image comprises taking into account vectors of parameters, respectively defined at a plurality of radial coordinates, in the plane of the sample, each vector of parameters being associated with one radial coordinate, and comprising a term representative of an optical para

Abstract: A method for observing a sample, the sample lying in a sample plane defining radial positions, parameters of the sample being defined at each radial position, the method comprising: a) illuminating the sample using a light source, emitting an incident light wave that propagates toward the sample; b) acquiring, using an image sensor, an image of the sample, said image being formed in a detection plane, the sample being placed between the light source and the image sensor; c) processing the image acquired by the image sensor, so as to obtain an image of the sample, the image of the sample corresponding to a distribution of at least one parameter of the sample describing the sample in the sample plane; wherein the processing of the acquired image comprises implementing an iterative method, followed by applying a supervised machine learning algorithm, so as to obtain an initialization image intended to initialize the iterative method.

Abstract: Method for detecting or predicting the occurrence of a cell event, selected from between cell division or cell death, in a sample (10), the sample extending in at least one sample plane (P10) and comprising cells (10p) immersed in a medium, the method comprising the following steps: a) arranging the sample between a light source (11) and an image sensor (16); b) illuminating the sample (10) using the light source (11) and acquiring a plurality of successive images ((Ii(ti), I1(ti+1) . . . I1(ti+K)) of the sample at different instants ([ti; ti+K]) forming an acquisition time range, each image being representative of an exposure light wave to which the image sensor is exposed; c) on the basis of each acquired image of the sample, calculating an observation image at each instant (I10(ti), I10(ti+1) . . .

Abstract: A method for characterizing a particle present in a sample, the sample lying between an image sensor and a light source and the sensor lying in a detection plane, includes illuminating the sample with the light source which emits an incident light wave propagating along a propagation axis, and acquiring an image of the sample with the sensor. The sensor is exposed to an exposure light wave. The image includes a plurality of elementary diffraction patterns each corresponding to one particle. The method also includes reconstructing a complex image representative of a complex amplitude of the light wave on a reconstruction surface passing through the sample, based on the acquired image; selecting a region of interest of the complex image corresponding to a particle of interest; forming an extracted image based on the region of interest; and characterizing the particle of interest depending on the extracted region of interest.

Abstract: A method for determining a parameter of a particle present in a sample, the method comprising the following steps: a) illuminating the sample with the light source, the light source emitting an incident light wave that propagates along a propagation axis; b) acquiring an image of the sample with the image sensor, the image sensor being exposed to an exposure light wave; c) determining a position of the particle in the detection plane; d) on the basis of the acquired image, applying a propagation operator, for a plurality of distances from a detection plane, so as to estimate, at each distance, a complex amplitude of the exposure light wave; e) on the basis of the complex amplitude estimated, at various distances, obtaining a profile representing a variation of the complex amplitude of the exposure light wave along an axis parallel to the propagation axis and passing through the position of the particle.

Abstract: A method for observing a sample, the sample lying in a sample plane defining radial positions, parameters of the sample being defined at each radial position, the method comprising: a) illuminating the sample using a light source, emitting an incident light wave that propagates toward the sample; b) acquiring, using an image sensor, an image of the sample, said image being formed in a detection plane, the sample being placed between the light source and the image sensor; c) processing the image acquired by the image sensor, so as to obtain an image of the sample, the image of the sample corresponding to a distribution of at least one parameter of the sample describing the sample in the sample plane; wherein the processing of the acquired image comprises implementing an iterative method, followed by applying a supervised machine learning algorithm, so as to obtain an initialization image intended to initialize the iterative method.

Abstract: A method for holographic characterization of a particle contained in a sample, based on an image, or hologram, of the sample obtained by an image sensor when the sample is illuminated by a light source. The hologram is the subject of a holographic reconstruction, to obtain a reference complex image, representative of the light wave transmitted by the sample in a reconstruction plane. A holographic propagation operator is applied to the reference complex image, to obtain a plurality of secondary complex images, from which a profile is determined describing the change in an optical feature of the light wave transmuted by the sample along the axis of propagation of the light wave.

Abstract: The invention relates to a method for observing a sample (15), comprising the illumination of the sample using a light source (11) and the acquisition of an image (Io) of the sample using an image sensor (16), the sample being disposed between the image sensor and the light source. Iterative steps are applied to the acquired image (Io), also referred to as a hologram, comprising: a single iterative numerical propagation (h), such as to estimate a complex image (A) of the sample in a reconstruction plane (P10) or in a detection plane (P0), in which the image sensor extends. The complex image can be used for the characterisation of the sample.

Abstract: There is provided a device allowing a sample to be observed in a first mode, by lensless imaging using a first sensor. The first mode allows a first image to be obtained, on the basis of which a region of interest of the sample may be identified. The device then allows, via a relative movement, the region of interest to be analyzed using a more precise second mode and in particular using an optical system coupled to a second sensor.

Abstract: A method for observing a sample (10), the sample lying in a plane of the sample defining radial coordinates, the method comprising the following steps: a) illuminating the sample using a light source (11), able to emit an incident light wave (12) that propagates toward the sample along a propagation axis (Z); b) acquiring, using an image sensor (16), an image (I0) of the sample (10), said image being formed in a detection plane (P0), the sample being placed between the light source (11) and the image sensor (16), such that the incident light wave sees an optical path difference, parallel to the propagation axis (Z), by passing through the sample; c) processing the image acquired by the image sensor; wherein the processing of the acquired image comprises taking into account vectors of parameters, respectively defined at a plurality of radial coordinates, in the plane of the sample, each vector of parameters being associated with one radial coordinate, and comprising a term representative of an optical para

Abstract: A method for determining a parameter of a particle present in a sample, the method comprising the following steps: a) illuminating the sample with the light source, the light source emitting an incident light wave that propagates along a propagation axis; b) acquiring an image of the sample with the image sensor, the image sensor being exposed to an exposure light wave; c) determining a position of the particle in the detection plane; d) on the basis of the acquired image, applying a propagation operator, for a plurality of distances from a detection plane, so as to estimate, at each distance, a complex amplitude of the exposure light wave; e) on the basis of the complex amplitude estimated, at various distances, obtaining a profile representing a variation of the complex amplitude of the exposure light wave along an axis parallel to the propagation axis and passing through the position of the particle.

Abstract: A method for observing a sample includes illuminating the sample with a light source and forming a plurality of images, by an imager, the images representing the light transmitted by the sample in different spectral bands. From each image, a complex amplitude representative of the light wave transmitted by the sample is determined in a determined spectral band. The method further includes backpropagation of each complex amplitude in a plane passing through the sample, determining a weighting function from the back-propagated complex amplitudes, propagating the weighting function in a plane along which the matrix photodetector extends, updating each complex amplitude, in the plane of the sample, according to the weighting function propagated.

Abstract: There is provided a device allowing a sample to be observed in a first mode, by lensless imaging using a first sensor. The first mode allows a first image to be obtained, on the basis of which a region of interest of the sample may be identified. The device then allows, via a relative movement, the region of interest to be analyzed using a more precise second mode and in particular using an optical system coupled to a second sensor.

Abstract: A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

Abstract: A method for identifying a particle contained in a sample, including illuminating the sample using a light source, the light source producing an incident light wave propagating toward the sample, then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the photodetector such that the matrix-array photodetector is exposed to a light wave that is the result of interference between the incident light wave and a diffraction wave produced by each particle. The method further includes applying a numerical reconstruction algorithm to the image acquired by the photodetector, to estimate a characteristic quantity of the light wave reaching the detector, at a plurality of distances from the detector. The variation in the characteristic quantity as a function of distance allows the particle to be identified.

Abstract: The invention relates to a method for observing a sample (15), comprising the illumination of the sample using a light source (11) and the acquisition of an image (Io) of the sample using an image sensor (16), the sample being disposed between the image sensor and the light source. Iterative steps are applied to the acquired image (Io), also referred to as a hologram, comprising: a single iterative numerical propagation (h), such as to estimate a complex image (A) of the sample in a reconstruction plane (P10) or in a detection plane (P0), in which the image sensor extends. The complex image can be used for the characterisation of the sample.

Abstract: A method for holographic characterization of a particle contained in a sample, based on an image, or hologram, of the sample obtained by an image sensor when the sample is illuminated by a light source. The hologram is the subject of a holographic reconstruction, to obtain a reference complex image, representative of the light wave transmitted by the sample in a reconstruction plane. A holographic propagation operator is applied to the reference complex image, to obtain a plurality of secondary complex images, from which a profile is determined describing the change in an optical feature of the light wave transmuted by the sample along the axis of propagation of the light wave.

Abstract: A method reconstructing optical properties of a medium uses a reconstruction system having a radiation source illuminating a medium and a detector receiving a signal emitted by the medium. This method includes establishing, for a source-detector pair, a first distribution of a signal received by the detector for a reference medium, the received signal emitted by the reference medium subsequent to the illumination of the medium by the source, determining, for the source-detector pair, a first modeling function of a light scattering signal between the source and the detector in the reference medium, establishing, for the source-detector pair, a second distribution of a signal received by the detector for the medium, the received signal being emitted by the medium to be characterized subsequent to illumination of said medium by the source, and computing a signal corrected as a function of the first modeling function and of the second distribution.