Ultrasonic probes for shock wave measurements

Extracorporeal shock wave lithotripsy (ESWL) has recently become the preferred procedure for the treatment of urinary and gall bladder stones. The device used in this treatment generates acoustic shock waves which are focused onto the stone, causing it to disintegrate. Interest in studying the properties of the shock waves quantitatively has intensified, since it is believed that the acoustic shock wave parameters, such as rise time, peak positive and peak negative pressure amplitudes, and frequency content, may influence the treatment's efficiency. In the present work the authors describe the evaluation of several piezoelectric materials and design configurations for their applicability to quantitative shock wave measurement. Preliminary experimental results indicate that PVDF (polyvinylidene fluoride) polymer sensors with a low acoustic impedance backing have the greatest potential as shock wave sensors.<>