Transient response of cylindrical piezoceramics used in self focusing transducers for therapy

Piezoelectric transducers used in therapy, for example in lithotripsy, consist of several thousand cylindrical piezoceramic elements which are driven by a high voltage pulse. In order to simulate the radiated pressure signal at the transducer surface the transient behaviour of a single cylindrical piezoceramic element was investigated using finite element analysis (FEA). The realistic electrical load conditions are integrated as well as the mechanical load given by the construction. Results show that the element does not behave like a piston source. Measurements agree to simulation results very well. It is concluded that the simulation results could provide valuable information for further design improvements of therapeutic transducers.