Abstract: The phantom kidney stone system for use with a commercial lithotripsy system includes a phantom kidney stone which simulates a human kidney stone and is suspended into the field of operation of the commerical lithotripsy system. The system also includes a trigger which is connected to receive a shock wave signal from the lithotripter which is representative of a shock wave output from the lithotripter. The trigger generates a trigger signal in response to the signal from the lithotripter. A counter is connected to receive the trigger signal and counts the number of trigger signals which is representative of the number of shock waves output from the lithotripter. A detection circuit is connected to the phantom kidney stone and produces a signal proportional to the detected size of the stone at a given point in time and compares the detected size of the stone to a predetermined reference size indicative of a condition wherein the stone would be crushed.