Title :
Self focusing on extended objects with time reversal mirror, applications to lithotripsy
Author :
Thomas, Jean-Louis ; Wu, François ; Fink, Mathias
fDate :
Oct. 31 1994-Nov. 3 1994
Abstract :
The objective is to focus an ultrasound beam on a target during lithotripsy. We propose to study the concept of a piezoelectric shock wave generator in which the focal zone is moved electronically to track the stone. For this purpose, we use the autofocusing property of time reversal mirrors (TRM) to track in real time a gall bladder or kidney stone embedded in its surrounding medium. We show that TRM allows us to obtain a sharp focusing on one bright point of the stone. The time of flight profile is then determined and used in a minimization method to calculate the spatial coordinates of the stone
Keywords :
biomedical ultrasonics; kidney; mirrors; nonlinear acoustics; piezoelectric transducers; radiation therapy; self-focusing; shock waves; ultrasonic focusing; ultrasonic transducer arrays; autofocusing property; bright point; extended objects; focal zone; gall bladder stone; kidney stone; lithotripsy; minimization method; piezoelectric shock wave generator; real time tracking; self focusing; sharp focusing; spatial coordinates; time of flight profile; time reversal mirror; ultrasound beam; Acoustic arrays; Biomedical applications of acoustic radiation; Biomedical transducers; Kidneys; Mirrors; Nonlinear acoustics; Piezoelectric transducers; Shock waves;
Conference_Titel :
Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE
Conference_Location :
Cannes, France
Print_ISBN :
0-7803-2012-3
DOI :
10.1109/ULTSYM.1994.401942
