EP3861942

[0001] A system that breaks calcium in a liquid includes a catheter (20) including first and second electrodes (22,24) arranged to receive there-across a high electrical voltage at an initial low current. The high electrical voltage causes an electrical arc to form across the electrodes (22,24) creating a gas bubble within the liquid, a high current to flow through the electrodes (22,24), and a mechanical shock wave. A power source (40) provides the electrodes (22,24) with the high electrical voltage at the initial current and terminates the high electrical voltage in response to the high current flow through the electrodes (22,24).