The document discusses electrohydraulic lithotripsy (EHL), a technique that uses electric sparks delivered in pulses between electrodes at the tip of a fiber to create shock waves. These shock waves oscillate and generate sufficient pressure to fragment stones by inducing the immediate expansion of surrounding liquid from the electric sparks. Modifications to the acoustic lens of an electromagnetic lithotripter produced a broader focal zone and improved pressure waveform, demonstrating better stone fragmentation in vitro.