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: Method for rheological characterization of a viscoelastic medium, comprising 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: The invention relates to a method and a device for imaging a visco-elastic medium. The method comprises an excitation step during which an internal mechanical stress is generated in excitation zone and an imaging step of acquiring signals during the movements generated by the mechanical stress in the visco-elastic medium in response to the internal mechanical stress in an imaging zone that includes the excitation zone. According to the invention, the method further comprises a step of calculating a quantitative index associated with the rheological properties of the visco-elastic medium at at least one point of the imaging zone situated at a given depth outside the excitation zone.

Abstract: Method for ultrasound imaging comprising at least the following steps: a) a transmission step in which a plurality of ultrasonic waves are transmitted into an imaged region and a set of raw data is acquired by an array of transducers in response to each ultrasonic wave, the ultrasonic waves having different spatial frequency content; b) a coherence enhancing step in which, for each of a plurality of virtual transmit focal zones in the imaged region, at least one set of coherent data is synthesized from the sets of raw data; c) a beamforming step in which, for each of a plurality of locations included in each of the virtual transmit focal zones, an image pixel is computed by beamforming, using the set of coherent data.

Abstract: The invention relates to an ultrasonic imaging probe for imaging a medium (10), comprising two types of transducers, characterized in that the first type of transducer(s) (1) is dedicated to ultrasonic imaging of the medium (10), and the second type of transducer(s) (2) is dedicated to generating a stress producing at least one transient modification of the imaged medium (10), both types of transducer(s) (1, 2) being able to operate at least in a so-called coupled mode where the first type of transducer(s) (1) operates in a synchronized way with the second type of transducer(s) (2) so as to image the time course of the transient modification of the medium (10).

Abstract: The inventive imaging method consists in generating a mechanical wave having shearing and compressional components in a viscoelastic medium and in determining the movement parameter of said viscoelastic medium at different points during the propagation of said mechanical wave. Said method comprises a correction stage when the movement parameter is processed for eliminating errors caused by the compressional component of the mechanical wave.

Abstract: The present invention relates to a method for generating mechanical waves within a viscoelastic medium (11) comprising a step of generating an acoustic radiation force (15) within the viscoelastic medium (11) by application of acoustic waves focussed on an interface (13) delimiting two zones (11, 14) having distinct acoustic properties.