LAUSR

Multi-element piezoelectric transducers used in shock wave generators for disrupting kidney stones (lithotripsy) or ablating soft tissues (histotripsy) are emitting high amplitude burst waves of one to ten pulses. Thus, most of the signal is sent while the piezoelectric transducers vibrate in a transient state. This work aims at optimizing the design of these elements. A transient finite element model of a piezoelectric circular element is presented. It includes the piezoelectric disk, the epoxy and plastic casing, the surrounding water and the RLC discharge circuit. The model was then used for parametric optimization of the electrical components and the front and back layers. It has been validated by comparing the numerical and experimental results of one 400 kHz, 37.3 mm diameter LT02 element (EDAP-TMS). The surface pressure field as measured by a fiberoptic hydrophone was in good agreement with the simulation. Elements with parameters resulting of optimization from different objective functions, which ...