Abstract: A method for transmitting digital data on a communication channel, between a transmitter base comprising N transmission antennas and K receivers. A signal carrier of frequency f0 and M sub-carriers of index m are used, adapted to transport K streams of digital data sk in parallel between the transmitter base and each receiver. The method comprises a step in which N.M complex symbols tn(m) are calculated from K.M symbols sk(m), by t n ? ( m ) = ? k = 1 K ? ? k · H k , n * ? ( m ) · s k ? ( m ) , where * denotes a complex conjugate, Hk,n(m) is a complex value estimating the transfer function of the communication channel between the transmission antenna n and the receiving antenna k at a corresponding frequency of the sub-carrier m, and ?k is a normalization coefficient.

Abstract: The invention relates to a method for measuring a mean visco-elasticity value for a soft material. Said method using a single probe carrying at least one transducer comprises the steps of: a) inducing, in a constraint zone, at least one burst of mechanical vibrations in order to generate internal shear waves in the tissue propagating from said constraint zone into the tissue, b1) measuring, with said transducer, the transient tissue displacements in at least one first measurement zone in the tissue, said first measurement zone being located away from said constraint zone, c) estimating a mean visco-elasticity of the region of the tissue situated between the constraint zone and the first measurement zone from said measured transient tissue displacements of the tissue in the first measurement zone.

Abstract: A device (10) for receiving and/or emitting an electromagnetic wave, comprising a medium (11) of dielectric material, a plurality of passive resonant elements (12) incorporated inside said medium, the plurality of passive resonant elements (12) comprising a frequency band-gap, two neighbour passive resonant elements belonging to the plurality being spaced apart from each other of a first distance lower than ?/4, and at least one active resonant element (13) incorporated inside said plurality, said active resonant element (13) having a second structure different from a first structure of the passive resonant elements (12), so that said active resonant element (13) has at least a second resonance frequency comprised inside the frequency band-gap of said plurality of passive elements (12).

Abstract: A method of high-resolution ultrasound imaging, in which transducers are made to emit ultrasound waves in a field of observations containing micro bubbles, by making the micro bubbles burst one by one in tandem with the emissions of ultrasound waves. At each shot j of an ultrasound wave, raw reverberated signals Sj(i,t) picked up by each transducer i are recorded, and then differential signals Vj(i,t) representative of variations between successive raw signals are determined, a parabolic function Pj(x) is fitted to the differential signals corresponding to each shot j, and then a crest Aj(x0,y0) of this function Pj, corresponding to the position of the micro bubble destroyed between shots j-1 and j, is determined.

Abstract: The invention relates to a method for measuring a mean visco-elasticity value for a soft material. The method uses a single probe carrying at least one transducer and includes the steps of: (a) inducing, in a constraint zone, at least one burst of mechanical vibrations in order to generate internal shear waves in the tissue propagating from the constraint zone into the tissue, (b1) measuring, with the transducer, the transient tissue displacements in at least one first measurement zone in the tissue, and wherein the first measurement zone is located away from the constraint zone, and (c) estimating a mean visco-elasticity of the region of the tissue situated between the constraint zone and the first measurement zone from the measured transient tissue displacements of the tissue in the first measurement zone.

Abstract: An imaging method using shear waves for observing a viscoelastic medium, comprising: several successive excitation steps j during which elastic shear waves are generated respectively at different excitation loci (Lj) in the viscoelastic medium by an imaging device, the different excitation loci being separated from one another by a maximum distance Dm, an imaging step corresponding to each excitation step j, in which a set j of successive raw images Imj(tk) of the viscoelastic medium at times tk are determined during propagation of the shear wave, the raw images having a resolution R which is larger than the maximum distance Dm, an averaging step in which raw images Imj(tk) corresponding to the same relative time tk are averaged to determine an average image Im?(tk).

Abstract: Method for rheological characterization of a viscoelastic medium, with the following steps: (a) an excitation step during which a vibratory excitation is generated in the viscoelastic medium leading to a deformation of the medium, (b) a deformation measurement step during which the deformation of the medium caused by the excitation is observed, (c) and a characterization step during which at least one non-zero power parameter y is determined such that a rheological parameter of the medium x is equal to x(f)=a+b·fy, where f is the frequency, a is a real number and b a non-zero scale parameter. It is thus possible to obtain mapping of the power parameter y.

Abstract: A system for illuminating an object with a wave or for imaging an object with a wave comprises a lens, a plurality of transducers and a control unit connected to the plurality of transducers. The lens comprises a plurality of resonator elements incorporated inside a medium and is able to convert a near field wave of the lens to a far field wave, or reciprocally. The resonator elements are at a sub wavelength distance from each others. The control unit provides signals to the transducers so that a plurality of points on the object are illuminated as desired, or obtains signals from the transducers to build an image of a plurality of points of the object. The points are at sub wavelength distance from each others.

Abstract: For locating a touch on a tactile surface belonging to an object, mechanical waves are made to propagate in the object and these mechanical waves are picked up. Certain characteristics of the signal picked up are compared to a library of reference characteristics, and the position of the touch is deduced from this comparison.

Abstract: A device for receiving and/or emitting an electromagnetic wave having a free space wavelength ?0 comprised between 1 mm and 10 cm, comprising a medium (11) of solid dielectric material and the free space wavelength ?0 corresponding to a wavelength ? inside the medium, a plurality of conductor elements (12) incorporated inside the medium and spaced apart from each other of a distance lower than ?/10, and one antenna element (13). The conductor elements are not loop elements. A tuned conductor element among the conductor elements has a first end at a distance from the antenna element which is lower than ?/10, and has a length Hwire adapted to generate an electromagnetic resonance in the tuned conductor element corresponding to the wavelength ?.

Abstract: A device for receiving and/or emitting an electromagnetic wave having a free space wavelength ?0 comprised between 1 mm and 10 cm, comprising a medium (11) of solid dielectric material and the free space wavelength ?0 corresponding to a wavelength ? inside the medium, a plurality of conductor elements (12) incorporated inside the medium and spaced apart from each other of a distance lower than ?/10, and one antenna element (13). The conductor elements form small loop elements. A tuned conductor element among the conductor elements has a first end at a distance from the antenna element which is lower than ?/10, and has an electric resonance frequency corresponding to the wavelength ?.

Abstract: A method for transmitting digital data on a communication channel, between a transmitter base comprising N transmission antennas and K receivers. A signal carrier of frequency f0 and M sub-carriers of index m are used, adapted to transport K streams of digital data sk in parallel between the transmitter base and each receiver. The method comprises a step in which N.M complex symbols tn(m) are calculated from K.M symbols sk(m), by t n ? ( m ) = ? k = 1 K ? ? k · H k , n * ? ( m ) · s k ? ( m ) , where * denotes a complex conjugate, Hk,n(m) is a complex value estimating the transfer function of the communication channel between the transmission antenna n and the receiving antenna k at a corresponding frequency of the sub-carrier m, and ?k is a normalization coefficient.

Abstract: The invention relates to a method for determining a physical parameter representative of a point P of a plate by means of a device comprising a first receiver for measuring a wave propagating in the plate, and a calculation unit. The method includes the following steps: measuring, by means of the first receiver, a first signal s1(t) representative of a wave propagating in the plate; defining a closed contour C on the plate surrounding said point P, the contour C being the location on the plate on which either a wave is generated by a first emitter, or the first signal s1(t) is measured; and determining the physical parameter at point P on the plate by identifying, thanks to at least said first signal, a shape function fshape(f), in the following equation: formula (I), where Wcontour and Gplate are functions of Green, and the shape function fshape(f) is dependent on the frequency f of the wave and on the physical parameter.

Abstract: The invention relates to an emulsion that can be activated by ultrasounds, comprising, in an emulsion in an aqueous solution, microparticles having a diameter of less than 10 ?m and containing an active agent and a gaseous precursor in a liquid form, encapsulated by a first emulsifier. The microparticles contain nanoparticles smaller than 1 ?m, in an emulsion in the gaseous precursor, each nanoparticle comprising an inner liquid that contains the active agent and is encapsulated by a second emulsifier.

Abstract: The invention concerns a method for optimizing the focusing of waves in a zone of interest of a medium, with the waves being emitted by a network of sources to the medium through an aberration-inducing element that introduces an initially indeterminate phase shift. The method according to the invention proposes to use M?1 successive modifications of the emitted wave, each giving rise to a perturbation. According to the invention, the M perturbations are measured in the zone of interest at each modification of the phase and/or amplitude distributions, and these measurements are used to deduce optimal focusing characteristics to maximize the perturbation induced in the zone of interest.

Abstract: Method for focusing an electromagnetic or acoustic wave on a point near which one or more diffusers are placed, comprising a learning step in which the pulsed responses hij(t) between the focus point and each antenna of the network are determined. Waves corresponding to signals Sji(t)=Si(t)hij(?t), where Si(t) is a function of time and hij(?t) is a temporal inversion of the pulsed response hij(t), can then be transmitted form said antennas of the network.

Abstract: A method of exploring by wave propagation, in which method an incident wave is emitted a plurality of times towards the same target zone (r0) in a diffusing medium, and then the backscattered signals generated by the waves are averaged.

Abstract: To mark an area of interest in a target medium, an initially inactivated and ultrasound-activatable optical marker is added to the medium, and then an ultrasound activation beam is emitted, being focused on the area of interest in order to locally activate the marker, which then colors the area of interest.

Abstract: The invention relates to a wave-propagation-based sounding method, in which: an incident wave is emitted through a medium including diffusers capable of reflecting the wave; and, subsequently, signals representing a reflected wave reverberated by the medium from the incident wave are captured, said captured signals being the sum of a single scattering component and a multiple scattering component. The captured signals are processed by separating the multiple scattering component from the single scattering component by filtering at least one frequency transfer matrix representing responses between transducers from the transducer assembly.

Abstract: The present invention relates to an analysis apparatus for analyzing the skin, the which includes an ultrasound probe arranged to analyze the skin along an axis and a vibrator arranged to emit at least one shear wave to a region of the skin extending about the axis. The ultrasound probe is arranged to detect displacements induced in the skin by the propagation of the shear wave.