Abstract: In order to obtain a predetermined ultrasonic wave field in a homogeneous internal part of a medium masked by an aberrating barrier, an ultrasonic lens is interposed between the emitting ultrasonic probe and the aberrating barrier. The ultrasonic lens is calculated by using a model of the medium comprising a mapping of ultrasonic wave propagation properties obtained from actual imaging of the medium such that when the ultrasound probe sends a predetermined ultrasonic wave, said predetermined wave generates the predetermined objective ultrasonic wave field in the medium.

Abstract: In order to obtain a predetermined ultrasonic wave field in a homogeneous internal part of a medium masked by an aberrating barrier, an ultrasonic lens is interposed between the emitting ultrasonic probe and the aberrating barrier. The ultrasonic lens is calculated by using a model of the medium comprising a mapping of ultrasonic wave propagation properties obtained from actual imaging of the medium such that when the ultrasound probe sends a predetermined ultrasonic wave, said predetermined wave generates the predetermined objective ultrasonic wave field in the medium.

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: A non-invasive method of obtaining a target soundwave field in the brain by means of an array of transducers positioned outside the skull, the method comprising a training stage during which, on the basis of a three-dimensional image giving the porosity of the skull at all points, digital simulation is used to determine individual sound signals to be emitted by the transducers in order to obtain the target soundwave field in the brain. After the training stage, the array of transducers is used to locate the position of the array of transducers relative to the skull by echography and to ensure that the array of transducers is accurately positioned.

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: The invention concerns a method for focusing acoustic waves useful for obtaining an image of a field to be observed in a dissipative heterogeneous medium (2, 3) around which acoustic transducers (T1–Tn, T?1–T?m) forming an imaging network and a target network. The method consists in following a training step during which pulse responses from the medium are measured between each transducer (Ti) of the imaging network (5) and several transducers (Tj) of the target network (6); deducing therefrom reference signals to be emitted by the transducers of the imaging network to produce a focused acoustic pulse in each transducer of the target network, then cumulatively, in determining reference signals to be emitted to focus an acoustic pulse on predetermined points in the medium. Said reference signals are stored and used subsequently to generate an acoustic image of the medium.

Abstract: A non-invasive method of obtaining a target soundwave field in the brain by means of an array of transducers positioned outside the skull, the method comprising a training stage during which, on the basis of a three-dimensional image giving the porosity of the skull at all points, digital simulation is used to determine individual sound signals to be emitted by the transducers in order to obtain the target soundwave field in the brain. After the training stage, the array of transducers is used to locate the position of the array of transducers relative to the skull by echography and to ensure that the array of transducers is accurately positioned.

Abstract: The invention concerns a method for focusing acoustic waves useful for obtaining an image of a field to be observed in a dissipative heterogeneous medium (2, 3) around which acoustic transducers (T1-Tn, T′1-T′m) forming an imaging network and a target network. The method consists in following a training step during which pulse responses from the medium are measured between each transducer (Ti) of the imaging network (5) and several transducers (Tj) of the target network (6); deducing therefrom reference signals to be emitted by the transducers of the imaging network to produce a focused acoustic pulse in each transducer of the target network, then cumulatively, in determining reference signals to be emitted to focus an acoustic pulse on predetermined points in the medium. Said reference signals are stored and used subsequently to generate an acoustic image of the medium.