New discharge circuit using high voltage transmission line for efficient shock wave generation: application to lithotripsy

In extracorporeal shock wave lithotripsy (ESWL), spreading wave amplitude is limited by the inductance of the discharge circuit. The goal of this study is to demonstrate the possibility of increasing pressure wave amplitude by using a low inductance transmission line. A high voltage transmission line has been constructed using a ferroelectric ceramic with relative dielectric constant equal to 1700 to give a total capacitance of 100 nF. A coaxial spark gap, with minimal inductance, has been developed to obtain triggered breakdown of the charged line. This new discharge circuit generates a high voltage rectangular pulse between underwater electrodes and then creates a spreading wave. Pressure amplitude and electroacoustic efficiency compared to conventional generators results demonstrate qualities of this new generator