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

Commissariat a L'energie Atomique

Intellectual Ventures Fund 83 LLC

Anne Koenig

Jean-Marc Dinten

Lionel Herve

Francois Perraut

Blandine Roig

Pierre Grangeat

Corinne Mestais

Alain Gliere

Anabela Da Silva

Sylvain Stanchina

Selimen Benahmed

Luc Andre

François Perraut

Nils Petitdidier

A device for measuring radiation backscattered by a sample including:

Device for measuring radiation backscattered by a sample and measurement method using such a device

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

The invention is a method for estimating a cardiac frequency via the detection of radiation backscattered or transmitted by a bodily zone. The part is illuminated, simultaneously or successively, by light radiation extending over a first spectral band and a second spectral band. A photodetector detects radiation emitted by the bodily zone under the effect of its illumination, in each of the spectral bands. A first detection function and a second detection function are formed from the radiation detected in each spectral band, respectively. The method allows the cardiac frequency to be determined via the determination of characteristic instants that are identified from the first detection function and the second detection function simultaneously.

Method for estimating a cardiac frequency and associated device

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

This method is designed for calculating a quantification indicator for quantifying a dermal reaction on a skin having several chromophores. The method includes illumination of a zone to be characterized on the skin, the skin reaction being included in the zone to be characterized; and measurement of the spectrum of a back scattered radiation coming from the skin after illumination of said zone to be characterized. The method also includes determination, according to the measured spectrum, of an absorption coefficient value for the zone to be characterized, and calculation, according to the absorption coefficient value, of each chromophore concentration. The method includes calculation of the quantification indicator according to each calculated chromophore concentration. The method includes determination, according to the measured spectrum, of a diffusion coefficient value of the zone to be characterized, and the quantification indicator is further calculated according to the diffusion coefficient value.

Method and system for calculating a quantification indicator for quantifying a dermal reaction on the skin of a living being

The method enables a non-homogeneous diffusing object to be examined by illuminating the object with a continuous light by means of a light source. It previously comprises reconstruction of the three-dimensional spatial mapping of an attenuation variable representative of the diffusion and absorption non-homogeneities of the object, by resolving a diffusion equation&#x2207;()&#x2212;()()=&#x3b4;().In the diffusion equation, Ais a constant, {right arrow over (r)} the spatial coordinate of any point of the mesh of a volume at least partially containing the object, and {right arrow over (r)}the spatial coordinate of the light source. The transfer functions of an equation used for reconstructing the distribution of fluorophores integrate the attenuation variable reconstituted in this way.

Method for reconstructing the distribution of fluorophores in a non-homogeneous medium by optical tomography in continuous mode

To examine a plate-shaped object comprising fluorophores and having a first face and an opposite second face, the method comprises a first sequential illumination step of the first face of the object with a fluorophore excitation light and a first sequential acquisition step of a first series of images by detecting light emitted by the second face of the object. The density of the lighting points is lower than the density of the detection points and the method further comprises a second sequential illumination step of the second face of the object with a fluorophore excitation light and a second sequential acquisition step of a second series of images by detecting light emitted by the first face of the object. Reconstruction of the three-dimensional fluorophore distribution image in the object is performed by means of the first and second series of images.

Method and device for reconstructing a three-dimensional fluorescence optical tomography image by double measurement

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

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.

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Saint Martin d'Uriage, France

Anne Koenig