Method for generating at least one shear wave in a target region of a soft solid, this method including at least the following steps: a) generating (1002, 1004, 1006) at least one shear wave (SW 1, SW 2, SW 3) in the target region; b) detecting (1003, 1005, 1007) a propagation pattern (P1, P2, P3) of the at least one shear wave in the target region; c) proceeding to a time reversal of the detected propagation pattern; d) submitting the target region to an excitation set of forces based on the temporally inverted propagation pattern, characterized in that: - step a) (1002, 1004) is implemented by generating at least two shear waves (SW 1, SW 2) with at least a first source of shear waves (SW 1, SW' 1) and at least a second source of shear waves (SW 2, SW' 2); - step b) is implemented with a detector unit which includes: - a row of ultrasonic transducers (Ti) aligned on a first direction perpendicular to a detection direction (Di) of each ultrasonic transducer or - a single ultrasonic transducer movable along a first direction perpendicular to its detection direction - during step b), a first propagation pattern is detected when only the first source is active and a second propagation pattern is detected when only the second source is active; - during step c), the first and second propagation patterns (P1, P2) are time-reversed (1008, 1009) independently from each other in order to generate, respectively, a first reverse excitation scheme (P1') and a second reverse excitation scheme (P2'), - at step d), the first source is controlled with the first reverse excitation scheme (P1') to generate at least a first modified shear wave (SW' 1), and, simultaneously, the second source is controlled with the second reverse excitation scheme (P2') to generate at least a second modified shear wave (SW' 2), whereas the shear waves are focused at a given point (Pi-j) of the target region. a) generating (1002, 1004, 1006) at least one shear wave (SW 1, SW 2, SW 3) in the target region; b) detecting (1003, 1005, 1007) a propagation pattern (P1, P2, P3) of the at least one shear wave in the target region; c) proceeding to a time reversal of the detected propagation pattern; d) submitting the target region to an excitation set of forces based on the temporally inverted propagation pattern, - step a) (1002, 1004) is implemented by generating at least two shear waves (SW 1, SW 2) with at least a first source of shear waves (SW 1, SW' 1) and at least a second source of shear waves (SW 2, SW' 2); - step b) is implemented with a detector unit which includes: - a row of ultrasonic transducers (Ti) aligned on a first direction perpendicular to a detection direction (Di) of each ultrasonic transducer or - a single ultrasonic transducer movable along a first direction perpendicular to its detection direction - a row of ultrasonic transducers (Ti) aligned on a first direction perpendicular to a detection direction (Di) of each ultrasonic transducer or - a single ultrasonic transducer movable along a first direction perpendicular to its detection direction - during step b), a first propagation pattern is detected when only the first source is active and a second propagation pattern is detected when only the second source is active; - during step c), the first and second propagation patterns (P1, P2) are time-reversed (1008, 1009) independently from each other in order to generate, respectively, a first reverse excitation scheme (P1') and a second reverse excitation scheme (P2'), - at step d), the first source is controlled with the first reverse excitation scheme (P1') to generate at least a first modified shear wave (SW' 1), and, simultaneously, the second source is controlled with the second reverse excitation scheme (P2') to generate at least a second modified shear wave (SW' 2), whereas the shear waves are focused at a given point (Pi-j) of the target region.