Commissariat a L'energie Atomique

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Jean-Marc Dinten

Jean Rinkel

Lionel Herve

Anne Koenig

Anabela Da Silva

Michel Darboux

Christine Robert-Coutant

Francois Perraut

Aurélie Laidevant

Ludovic Lecordier

Blandine Roig

Marc Arques

Philippe Rizo

Joachim Tabary

Corinne Mestais

Veronique Rebuffel

Alain Gliere

Andrea Brambilla

Jérôme Boutet

François Perraut

Guillaume Beldjoudi

Véronique Rebuffel

Anne-Sophie Montcuquet

Georges Gonon

Sébastien Christopher Coello

Andréa Brambilla

Elisa Fabiani

Florent Mougel

Determining an optical property of a sample having an illumination of a surface of the sample with the aid of a light beam, so as to form, on the surface of the said sample, an elementary illumination zone, corresponding to the part of the said surface illuminated by the said sample. A detection of N optical signals, backscattered by the sample, each optical signal emanating from the surface of the sample at a distance, termed the backscattering distance, from the said elementary illumination zone, N being an integer greater than or equal to 1, so as to form as many detected signals. A determination of at least one optical property of the sample, by comparison between: a function of each signal thus detected and a plurality of estimations of the said function each estimation being carried out by considering a predetermined value of the said optical property, characterized in that during the said detection step, at least one backscattering distance is less than 200 pm.

Method for characterizing a sample by measurement of a backscattered optical signal

A method correcting a measured spectrum of X radiation, according to a number of channels Nc, each channel i corresponding to an energy range between Eand Ei+&#x394;E, including: determining function &#x3b4;t(k) determining size of temporal deviation &#x394;t interval separating two interactions with energy Eand E, stacking of which leads to a detected energy value E; determining, from the function &#x3b4;t(k), probability function P(k) that an event counted in a channel k corresponds to a stack of two interactions, respectively of energies Eand E; determining, from the probability function P(k), a stack spectrum as a part of the measured spectrum that corresponds only to the stacks alone; and calculating or estimating at least a first corrected spectrum, by the difference between the measured spectrum and the stack spectrum.

Method for correcting the stacking phenomenon applied to X-ray spectrums acquired using a spectrometric sensor

The invention relates to a method for correcting an optical signal produced by a sample comprising the following steps:

Method for correcting a signal backscattered by a sample and associated device

A system for reconstructing optical properties of a diffusing medium including at least one pulsed radiation source capable of illuminating the diffusing medium, at least one first detector of a first type, capable of receiving a signal emitted by the medium, the first detector being a time-resolved detector, and an information processing unit for processing at least one source&#x2014;first detector pair, a time distribution of the signal received by the corresponding first detector. The reconstruction system also includes at least one second detector of a second type, each second detector being made up of a set of pixel(s) from an image sensor capable of acquiring an image of the medium, and the second detector being capable of measuring an intensity of the signal emitted by the medium, the intensity corresponding to an equivalent moment of order 0 for the corresponding source&#x2014;second detector pair.

System for reconstructing optical properties in a diffusing medium, comprising a pulsed radiation source and at least two detectors of two different types, and associated reconstruction method

A calibration method for a device for identifying materials using X-rays, including: a) determining at least one calibration material and, for each calibration material, at least one calibration thickness of this material, b) measuring, for each of the calibration materials and for each of the selected calibration thicknesses, attenuation or transmission coefficients for X radiation, c) calculating statistical parameters from the coefficients, d) determining or calculating, for each calibration material and for each calibration thickness, a presence probability distribution law, as a function of the statistical parameters.

Method of identifying materials from multi-energy X-rays

The invention relates to a device for identifying a material of an object having a source of X-Ray photons and a spectrometric detector, the source irradiating the object with an incident beam and the detector measuring a magnitude of a backscattered beam from the incident beam after scattering in a volume (&#x3b4;V) of the material and an energy of the X-Ray photons of the backscattered beam. The incident and backscattered beams forming a scattering angle (&#x3b8;). An adjusting device adjusts the position between the source, the detector and the object in order for the volume to be at different depths with a constant angle. A processing device processes the two magnitudes in two positions and the energy in one position and calculates an attenuation coefficient (&#x3bc;material (E, E, &#x3b5;)). An estimating device estimates the density (&#x3c1;) of the material.

Method and device for identifying a material of an object

A method for locating at least one optical marker in a diffusing medium, the marker having at least one optical property different from the diffusing medium, wherein: a) a pulsed radiation interacts with the medium and the at least one optical marker, producing an optical signal, and at least one acquisition of data of the optical signal is performed, each acquisition including one or more time components of interest, due to the at least one marker, and a spurious component, due to the medium other than the at least one marker, b) a multidimensional array X is formed from the optical signal data of the at least one of the acquisitions, c) the array X is processed by factorization into a product of only two non-negative multidimensional arrays A and S, and d) at least one of the time components is extracted from the arrays A and S.

Method for locating an optical marker in a diffusing medium

The invention relates to a method of localising a fluorophore () in a scattering medium (), by means of a radiation source () suited to emitting an excitation radiation of this fluorophore and detection means () suited to measuring a fluorescence signal (&#x3a6;) emitted by this fluorophore () comprising:

Method and device for localising fluorophores or absorbers in a surrounding medium

The invention concerns a method for locating at least one absorber in a diffusing medium, using at least one excitation radiation and at least one detector (&#x3a6;), including: 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 absorber after this excitation, b) identification of meshing of the volume into mesh elements, and c) estimation of the location of the absorber in its diffusing medium, by computing a function (P) of at least one of three parameters.

Device and method for spatial reconstructing of absorbers mapping

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 (&#x3a6;), 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 (P) of at least one of three parameters.

Device and method for spatial reconstructing of fluorescence mapping

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 &#x3c4; 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 &#x3c4;, of the position or the distribution of fluorophore in said medium.

Method and device for 3D reconstruction of the distribution of fluorescent elements

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.

Method for reconstructing a fluorescence-enhanced optic tomography image of an object with any outline

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 (COMP) 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 (CPT, CPT) 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 (CPT) or another counter (CPT) depending on the result of the analysis. Applicable in particular to bi-energy radiology and X-photon impact spectrometry analysis.

Photon counting detector with comparator and switchover rate analyzer

The radiation scattered in a two-dimensional detector () by a radiation is estimated by subjecting the detector () to at least two irradiations by inserting an array () of separated absorbers placed at variable distances (L) from the detector (), measuring the (scattered) radiation at the shadow spots () 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.

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Lyons, France

Jean-Marc Dinten