Abstract: A device and method for processing fluorescence signals emitted after excitation by radiation coming from a radiation source, by at least one fluorophore with a lifetime ? in a surrounding medium, which signals are detected by detection means, and which method includes the calculation, on the basis of detected fluorescence signals, of values of a variable, independent of ?, of the position or the distribution of fluorophore in said medium.

Abstract: The invention concerns a method for locating at least one fluorophore or at least one absorber in a diffusing medium, using at least one excitation radiation and at least one fluorescence detector (?fluo), comprising: a) for at least one pair (radiation source-detector), at least one excitation by the radiation source, and at least one detection of the fluorescence signal emitted by the fluorophore after this excitation, b) identification of meshing of the volume into mesh elements, c) estimation of the location of the fluorophore or absorber in its diffusing medium, by computing a function (Pm) of at least one of three parameters.

Abstract: A device and method for processing fluorescence signals emitted after excitation by radiation coming from a radiation source, by at least one fluorophore with a lifetime ? in a surrounding medium, which signals are detected by detection means, and which method includes the calculation, on the basis of detected fluorescence signals, of values of a variable, independent of ?, of the position or the distribution of fluorophore in said medium.

Abstract: The invention relates to a method of localising a fluorophore (22) in a scattering medium (20), by means of a radiation source (8, 10) suited to emitting an excitation radiation of this fluorophore and detection means (4, 12) suited to measuring a fluorescence signal (?fluo) emitted by this fluorophore (22) comprising: a) for at least 3 different pairs of positions of the radiation source and detection means, an excitation by a radiation coming from the radiation source (8), and a detection by means (4) of detecting the fluorescence signal emitted by this fluorophore after this excitation, b) for each of these pairs, the identification of a surface on which the fluorophore is situated, or a volume comprising this surface and in which the fluorophore is situated, c) an estimation of the localisation of the fluorophore in its surrounding medium, by calculation of the intersection of the three surfaces, or if necessary a volume around this intersection.

Abstract: A device and method for processing fluorescence signals emitted after excitation by radiation coming from a radiation source, by at least one fluorophore with a lifetime ? in a surrounding medium, which signals are detected by detection means, and which method includes the calculation, on the basis of detected fluorescence signals, of values of a variable, independent of ?, of the position or the distribution of fluorophore in said medium.

Abstract: The method enables a heterogeneous object containing fluorophores to be examined. A first face of the object is illuminated with an excitation light exciting the fluorophores. The light emitted by a second face of the object, opposite the first face, is detected by means of a matrix of detectors. The fluorophore distribution is determined by means of relevant Green's functions each associated with a selected source and/or detector, able to be assimilated to a point of the surface of the object. Thus, a first spatial coordinate of each of the relevant Green's functions corresponds to a point of the first face of the object and/or a second spatial coordinate of each of the relevant Green's functions corresponds to a point of the second face of the object.

Abstract: The invention relates to detectors for radiological imaging, and more particularly the X-ray matrix detectors, produced in the form of a CMOS technology pixel matrix, associated with a structure for converting X-rays into electrons. Each pixel comprises a reading circuit comprising on the one hand a comparator (COMP1) switching over each time a charge increment arrives resulting from the integration of a charge current generated by the lighting and on the other hand a counting circuit (CPT1, CPT2) for counting the number of switchovers of the comparator. The circuit for reading each pixel comprises a circuit (CMC) for analyzing the rate of the switchovers of the comparator, this analysis circuit acting on the counting circuit to modify its operation according to the result of the rate analysis. For example, the analysis circuit switches the counting pulses to one counter (CPT1) or another counter (CPT2) depending on the result of the analysis.

Abstract: The radiation scattered in a two-dimensional detector (2) by a radiation is estimated by subjecting the detector (2) to at least two irradiations by inserting an array (3) of separated absorbers placed at variable distances (L) from the detector (2), measuring the (scattered) radiation at the shadow spots (6) of the absorbers and interpolating elsewhere to provide continuous images of the scattered radiation, and by deducing parameters modelling a scattered radiation distribution function in the detector.

Abstract: The method is analytical, involves a single irradiation of the object at a plurality of incidences in order to obtain a first three-dimensional image of the total radiation received by the detector, but a double irradiation of a set of calibration phantoms, such as planar plates, in order to obtain their images of the total radiation and the scattered radiation. The three-dimensional image serves only to precisely evaluate, for each projection of the radiation through the object, the equivalent length of the material of the phantoms in order to obtain a similar scattered radiation. In a known manner, a ratio of scattered radiation layers is then calculated for the object and the phantoms according to the total radiation that they have received, and the scattered radiation of the object is obtained by the radiation scattered by the phantoms, which have been measured, and the ratio.

Abstract: The invention relates to detectors for radiological imaging, and more particularly the X-ray matrix detectors, produced in the form of a CMOS technology pixel matrix, associated with a structure for converting X-rays into electrons. Each pixel comprises a reading circuit comprising on the one hand a comparator (COMP1) switching over each time a charge increment arrives resulting from the integration of a charge current generated by the lighting and on the other hand a counting circuit (CPT1, CPT2) for counting the number of switchovers of the comparator. The circuit for reading each pixel comprises a circuit (CMC) for analyzing the rate of the switchovers of the comparator, this analysis circuit acting on the counting circuit to modify its operation according to the result of the rate analysis. For example, the analysis circuit switches the counting pulses to one counter (CPT1) or another counter (CPT2) depending on the result of the analysis.

Abstract: The invention relates to a method for processing fluorescence signals emitted after excitation by radiation coming from a radiation source, by at least one fluorophore with a lifetime r in a surrounding medium, which signals are detected by detection means, and which method comprises the calculation, on the basis of detected fluorescence signals, of values of a variable, independent of ?, of the position or the distribution of fluorophore in said medium.

Abstract: The method enables a heterogeneous object containing fluorophores to be examined. A first face of the object is illuminated with an excitation light exciting the fluorophores. The light emitted by a second face of the object, opposite the first face, is detected by means of a matrix of detectors. The fluorophore distribution is determined by means of relevant Green's functions each associated with a selected source and/or detector, able to be assimilated to a point of the surface of the object. Thus, a first spatial coordinate of each of the relevant Green's functions corresponds to a point of the first face of the object and/or a second spatial coordinate of each of the relevant Green's functions corresponds to a point of the second face of the object.

Abstract: The radiation scattered in a two-dimensional detector (2) by a radiation is estimated by subjecting the detector (2) to at least two irradiations by inserting an array (3) of separated absorbers placed at variable distances (L) from the detector (2), measuring the (scattered) radiation at the shadow spots (6) of the absorbers and interpolating elsewhere to provide continuous images of the scattered radiation, and by deducing parameters modelling a scattered radiation distribution function in the detector.

Abstract: The method is analytical, involves a single irradiation of the object at a plurality of incidences in order to obtain a first three-dimensional image of the total radiation received by the detector (2), but a double irradiation of a set of calibration phantoms, such as planar plates, in order to obtain their images of the total radiation and the scattered radiation. The three-dimensional image serves only to precisely evaluate, for each projection of the radiation (5) through the object (8), the equivalent length of the material of the phantoms in order to obtain a similar scattered radiation. In a known manner, a ratio of scattered radiation layers is then calculated for the object and the phantoms according to the total radiation that they have received, and the scattered radiation of the object is obtained by the radiation scattered by the phantoms, which have been measured, and the ratio.

Abstract: The method enables the distribution of fluorescent elements in a diffusing medium having substantially a finite cylindrical shape to be reconstructed. The method comprises formulation of a plurality of first energy transfer functions respectively representative of the energy transfer between the punctual excitation light source and the fluorescent elements and formulation of a plurality of second energy transfer functions respectively representative of the energy transfer between the fluorescent elements and the detector. The first transfer functions and the second transfer functions can thus be Green functions solving the diffusion equation and corresponding to a finite cylindrical volume, the Green functions being expressed as a function of the modified Bessel functions.

Abstract: In a radiographic method where an object (2) is studied in several steps by a radiation (4) occupying various positions (4i, 4j) just as the associated network of detectors (3i, 3j), the combination of elementary vignettes into an overall image without junction defects is resolved by a discretisation of the object (2) into volumes and a calculation of the attenuation in each volume (voxel) (8) to obtain images of the object at different reconstruction heights; then said images are combined with each other to obtain a final, more exact image.

Abstract: The image of an object is improved by estimating the scattered radiation that it transmits to the detectors. To achieve this, one uses the scattered radiation effectively measured through an imitation of the object, having analogous attenuation properties, and which one modifies by the weighting coefficients obtained by a transformation of the values of the total radiation received through the object (3) and the selected imitation (8). One thus manages to improve the image without subjecting the object to a double irradiation in order to measure the scattered radiation separately. The principal applications are tomography, bone densitometry and non-destructive controls.

Abstract: The image of an object is improved by estimating the scattered radiation that it transmits to the detectors. To achieve this, one uses the scattered radiation effectively measured through an imitation of the object, having analogous attenuation properties, and which one modifies by the weighting coefficients obtained by a transformation of the values of the total radiation received through the object (3) and the selected imitation (8). One thus manages to improve the image without subjecting the object to a double irradiation in order to measure the scattered radiation separately. The principal applications are tomography, bone densitometry and non-destructive controls.

Abstract: This radiography process utilizes dual-energy rays and comprises, in order to differentiate bone, lean and fatty tissues at the same time, an improvement consisting in assessing the total length penetrated by each ray while correcting the errors which may be produced by internal gas pockets. One proceeds as follows: selection of certain rays which have not penetrated bone tissues; calculation of the thicknesses of lean and fatty tissues penetrated by these rays according to the two attenuations, the sum of these two thicknesses being the length of attenuation; estimation of the length of attenuation elsewhere, in particular by means of interpolations; and calculation of the thicknesses of the three categories of tissues penetrated according to this total length of attenuation and the two attenuations.

Abstract: In a radiography method with double energy conical beam, a preliminary calibration of the system involves using a device made up of blocks of different thicknesses of a first material, in stepped form here (1), composed of layers (2, 3, 4, 5), and which further comprises inserts (7) partly formed (12) of another material. A sufficient number of thickness combinations crossed by the radiation is obtained for each of the materials, while still producing scattered radiation resembling that of the subject, because of the similarity of the proportions and distribution of the two materials; a single digital method for estimation and correction for scattered radiation can then be applied.