Shock wave lithotripter and method for using the same

Abstract

A shock wave lithotripter includes a shock wave generator for producing shock waves that are focused at a focus point remote from the shock wave generator during operation of the lithotripter, and an ultrasound probe having a transducer for producing ultrasound beams defining a plane of radiation during a calibration mode of operation of the lithotripter. Associated with the ultrasound probe is a screen for showing a display of the region illuminated by the beams. During calibration, the free end of a focal point target is positioned at the focus point of the lithotripter. The probe is moved in a direction perpendicular to the plane of the radiation beams produced by the probe until the free end of the target is illuminated by the ultrasound radiation. The location on the screen of the free end of the target is marked to indicate the location of the focus point of the shock wave generator in the display. The target is removed, and the lithotripter is then positioned relative to a patient such that a stone in the body of the patient, as displayed on the screen associated with the ultrasound scan, coincides with the mark on the screen representing the focus point of the lithotripter. Shock waves produced by the shock wave generator are thus focused on the stone which is fragmented by shock waves when the generator is activated.