Commissariat a L'energie Atomique

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

Intellectual Ventures Fund 83 LLC

Universitë De Bordeaux

Pierre Grangeat

Philippe Rizo

Regis Guillemaud

Jerome De Murcia

Anne Koenig

Laurent Desbat

Patrick Le Masson

Jean-Francois Giovannelli

Solange Delageniere

Pascal Sire

Stephen Azevedo

Thomas Rodet

Stéphane Bonnet

Henri Grateau

Ali Mohammad-Djafari

Rémi Perenon

Alexandre Chibane

Francois Bertholon

Olivier Harant

Laurent Gerfault

François Bertholon

Jean-François Giovannelli

The invention is a method for estimating a retention time of a particle in a chromatography column, and more particularly in a chromatography column one parameter of which, such as temperature, is modulated. The retention time is estimated on a probabilistic basis by sequentially modelling the transit of the particle in the column. When this stochastic approach is adopted for a set of particles of a given type, it allows a statistical distribution of the retention time in the column to be determined.

Method for estimating a retention time in a chromatography column

The method for detecting defective electrodes in an electrode matrix comprises measurement of an electrochemical impedance spectrum for each of the electrodes. Modeling of the spectrum impedance relative to each electrode by means of an implicit non-integral frequency model is performed in the form of a parameter matrix. Principal components analysis of the matrix is performed to transform said parameter matrix into a final matrix containing decorrelated variables representing the parameter matrix in a new space. The distance between each electrode and a reference point is calculated. These calculated distances are compared with a preset threshold distance and the electrodes having a distance greater than the threshold distance are classified as being defective.

Method for detecting defective electrodes in a micro-electrode matrix

A method for estimating a molecular mass parameter in a sample that includes at least one component of given molecular mass, comprising the steps consisting of passing the sample through a processing chain comprising a mass spectrometer with a MEMS or NEMS electromechanical sensor, in this way obtaining a signal representing the molecular mass parameter and estimating the molecular mass parameter by means of a signal processing device. The molecular mass parameter is defined on the basis of a parameter of time distribution of successive detections, by the MEMS or NEMS electromechanical sensor, of the adsorption of said component, and the estimation of the molecular mass parameter is made by Bayesian inference, on the basis of a direct analytical modeling of said signal according to the molecular mass parameter and to technical parameters of the processing chain comprising at least one technical parameter of the MEMS or NEMS electromechanical sensor.

Method and apparatus for estimating a molecular mass parameter in a sample

Measurements of a mobile object and particularly a living being are made using two techniques, normally radiation attenuation and radiation emission, in synchronization to provide images of the object state. Movement displacement fields from one phase to the next are estimated for both techniques, but the final images obtained by the emission technique are improved by the knowledge of the displacement field obtained by the other technique that is more precise.

Method of reconstructing an image acquired using several imagery modes

A method for estimating molecule concentrations in a sample, the method including: obtaining a signal generated by a sample analyzing apparatus, the signal including at least one spectrum, the spectrum including peaks representative of the molecule concentrations in the sample and being expressed as a function of at least one variable; obtaining an analytical modeling of the signal with a modeling function, wherein the modeling function is based on the molecule concentrations and factors including gain factors of the equipment and description factors of the peaks; selecting uncertain factors in the factors; determining a priori probability distributions for the uncertain factors and the molecule concentrations; establishing, with the modeling function and the signal, posteriori probability distributions for the molecule concentrations and the uncertain factors; and estimating, with a processing module, the molecule concentrations and the uncertain factors from a parameter inferred from the posteriori probability distributions.

Method for estimating molecule concentrations in a sampling and equipment therefor

Sets of projections of measurements through an object () the image of which is to be represented, undergo Fourier transforms before being broken down into blocks according to cutoff frequencies. The blocks are separately reconstructed in order to form a series of thumbnail images of the object, which are then combined in order to reconstruct the final image. The reconstruction calculations on the thumbnail images are rapid and often a large portion of the blocks will be discarded, notably those which are at high frequencies, whereby their contribution may frequently be neglected as well as the noise effects which accumulate therein. The invention is applied to medical or industrial tomography methods and is of larger interest for mobile objects, the movement of which may be estimated and compensated.

Method for accelerated reconstruction of a three-dimensional image

A very fast reconstruction is undertaken in an image reconstruction process by tomography, by dividing measurements through the subject into a series of subsequent sets that are inverted by back projections giving partial result blocks used to search for the change law for the subject. Partial contents of the image can then be predicted at a reference time and their accumulation gives the image. The law for how the subject changes with time is evaluated and is used to compensate for partial results before their accumulation.

Method for reconstruction of an image of a moving object

The present invention consists of obtaining from a series of measurements or original images of varying precision of a mobile object, such as a beating heart, a sequence of restored images minimizing an error function comprising an adequation term between the restored images and the measurements, a space moving term of images to be restored and a time smoothing term of restored images, taking account of an evaluation of the movement of the object between the original image during the considered phase of the movement and the image of the object in a neighboring phase.

Process for producing a restored sequence of images of a moving object

Apparatus and process for obtaining three-dimensional images of an object by a planar array of detectors, whose focusing points are located on a circle. The advantage obtained is a wider detection field that in the case of focusing on a single point. Rules are given for using algorithms for inverting characteristic measurements of the conical focusing. Application to medicine and to non-destructive testing in industry.

Installation and process for the reconstruction of three-dimensional

Tomographic process for the reconstruction of three-dimensional images of an object such as the heart or another organ on the basis of sets of measurements relative to a group of different states of the object. An approximate image of the object in each state (f) is reconstituted on the basis of associated measurements and the movements of said object from a reference state to each of the states are evaluated (D.sub.k). The estimation of the image of the object at the reference state (f.sub.0) is obtained by a convergence towards the real image by gradually incorporating in the estimated image information relative to the measurements and to the previously calculated movements of the object.

Process for the reconstruction of three-dimensional images on a mobile

A process provides a cartography of an emission of radiation by a body (2) that is corrected with respect to the attenuation of radiation by the body. A radiation transmissions source (3) is able to assume several positions with respect to the body and emits photons toward the body. The process includes: for each position of the radiation source, determining a transmission measurement (N) of the photons emitted by the radiation source and transmitted by the body and determining an emission measurement projection of the photons emitted by the body, the transmission measurement and the emission measurement projection being performed with the same geometry of the body. Determining, for each position of the radiation source, an attenuation correction coefficient C of radiation due to the body in order to correct the emission measurement projection (E6); and then constructing an emissions map (E2) on the basis of the attenuation-corrected, emission measurement projections.

Process for carrying out emission cartography of a body corrected with

Process and installation making it possible to reconstitute precise images of an area of interest (2) of an object (1) by reducing the errors produced by the contribution of the compliment of the object. A first series of measurements is carried out, where a conical beam (10) only takes in the area of interest of the object (2) and this is followed by a second series of measurements in which the beam takes in the entire object. A combination of the measurements of the two series is carried out in order to make them compatible and obtain a more accurate image of the area of interest (2).

Process for the reconstruction of three-dimensional images of an area of

Process for the reconstruction of three-dimensional images of an object. Several measurements are performed by displacing a bidimensional array of sensors, sensitive to a radiation passing through the object or coming from the object in at least two circular paths. The digital method for making it possible to synthesize the informations measured and in particular convert the informations obtained into reference frames linked with the paths in a random reference frame is given. Application to medical imaging or to non-destructive inspection.

Process and apparatus for the reconstruction of three-dimensional images

Process for the reconstruction of three-dimensional images of an object (3), in which the reconstruction is obtained by calculating sums of projections on planes extracted from a conical attenuation radiation traversing the object, or an emission from the object in accordance with a conical collimation. The bidimensional detector array (4) used for this purpose has a random inclination (.xi.) with respect to the rotation axis defining the mark in which the image is reconstructed as a result of a voluntary choice. Formulas are given making it possible to obtain a limited distortion reconstruction after measuring the displacement parameters of the array and the conical radiation beam. The position errors resulting from construction defects are also taken into account in the calculations after measurement. A parameter measurement protocol and the associated calculation process are also described.

Process for the reconstruction of three-dimensional images of an object

The present invention provides a method for generating three-dimensional images of an object having a network of points. One preferred embodiment of the present invention comprises using a moving two-dimensional sensor network array to take measurements, at successive discrete time intervals, of radiation emanating from the network of points. The sensors generate electrical signals representative of the object at the discrete time intervals, which impulses are used to generate a system of linear equations describing the object at these discrete time intervals. A change function function is generated to describe the object in between the discrete time intervals. Finally, electrical signals representative of a continuous description of the object are generated using the system of equations and the change function, which continuous description are used to generate three-dimensional images of the object.

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Saint Ismier, France

Pierre Grangeat