Method and device for localization and focusing of acoustic waves in tissues
AssigneeUniversite Paris VII-Bureau de la Valorisation et de Relations Industrielle
InventorMathias Fink
Life of this patent
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Abstract
For focussing an ultrasound beam delivered by a transducer array on a reflective target in a medium, for instance in organic tissues, the zone including the target is illuminated with an unfocussing acoustic beam. The shapes and position of echo signals delivered by electro-acoustic transducers of a regular array are individually stored; the distribution in time and the shapes of the echo signals for obtaining reversed signals are reversed and the reversed signals are applied to the respective transdcuers of the array.
Claims15
A process for acoustically localizing a reflective target in an environment, comprising the steps of:
- (a) illuminating a zone of the environment including a target to be detected with an unfocussed acoustic beam;
- (b) individually storing the shapes and positions of echo signals each delivered by one of a plurality of electro-acoustic transducers distributed at nodal points of a geometrical array following illumination by said acoustic beam;
- (c) reversing the distribution in time and the shapes of each of the echo signals for obtaining reversed signals;
- and
- (d) applying each of said reversed signals to the transducer of the array from which the respective reversed signal was derived for illuminating said zone again.
Process for localizing an object which has a reflectivity lower than that of a target but higher than that of the balance of the environment, comprising the steps of:
- (a) illuminating a zone of the environment including said target and said object with an unfocussed acoustic beam;
- (b) individually storing the shapes and positions of echo signals each delivered by one of a plurality of electro-acoustic transducers distributed at nodal points of a geometrical array following illumination by said acoustic beam;
- (c) reversing the distribution in time and the shapes of each of the echo signals for obtaining reversed signals;
- (d) applying each of said reversed signals to the transducer of the array from which the respective reversed signal was derived for illuminating said zone again;
- (a1) illuminating said zone including the previously localized target with a non-focussed acoustic wave beam;
- (b1) collecting and storing echo signals received by the transducers of said array and individually storing the shapes and positions in time of said echo signals;
- (b2) individually subtracting the echo signals received by each transducer of the array and stored during said last step (b) from the stored echo signals obtained during step (b1);
- (c1) reversing the time distribution and the shapes of the results of the subtraction for obtaining further reversed signals;
- and
- (d1) applying said further reversed signals to the respective transducers of said array.
A device for acoustic processing of acoustic wave reflective targets in an environment, comprising:
- means for illuminating a zone of the environment including said targets with an unfocussed acoustic beam;
- plurality of electro-acoustic transducers distributed in an array;
- and
- a respective processing channel associated with each of said transducers and having:
- means for storing the wave form and time occurence of an echo signal received by the respective transducer and for generating a wave whose shape and time occurence are reverse;
- and
- means for amplifying the reversed wave and applying it to the respective transducer.
A device for acoustic localization of acoustic wave reflective targets in an environment, comprising:
- means for illuminating a zone of the environment including said targets with an unfocussed acoustic beam;
- a plurality of electro-acoustic transducers distributed in an array;
- and
- a respective processing channel associated with each of said transducers and having:
- means for storing the wave form and time occurence of an echo signal received by the respective transducer and for generating a wave whose shape and time occurence are reversed;
- and
- means for amplifying the reversed wave and applying it to the respective transducers.
A process for destructing a stone in tissues with focussed ultra-sound energy, comprising the steps of:
- (a) illuminating a zone of the environment including a target to be detected with an unfocussed acoustic beam;
- (b) individually storing the shapes and positions of echo signals each delivered by one of a plurality of electro-acoustic transducers distributed at nodal points of a geometrical array following illumination by said acoustic acoustic beam;
- (c) reversing the distribution in time and the shapes of each of the echo signals for obtaining reversed signals;
- (d) applying each of said reversed signals to the transducer of the array from which the respective reversed signal was derived for illuminating said zone again;
- (e) individually storing at least the relative time positions of maxima of the echo signals each delivered by one of said electro-acoustic transducers,
- whereby the ratio between the energy reflected by the target and the energy reflected or scattered by local irregularities in said tissues is enhanced and a final ultra-sound wave front can be recorded;
- and
- reproducing said wave front with an increased amount of ultra-sound energy for focussing sufficient ultra-sound energy on said stone to destruct said stone.
Dependencies are inferred from the claim text.