[Types of equipment, technical developments and peculiarities of extracorporeal lithotripsy--problems in locating the calculus].

Three methods are used for the extracorporeal distintegration of gallstones and kidney stones. Shock waves can be generated by an underwater spark, the discharge of piezoelectric crystals, or electromagnetic waves. The shock waves must then be focussed to disintegrate the stones. Depending on how they are generated the focus of the shock waves is like a dot or an ellipsoid. In most cases the stones can be localized by ultrasound. X-ray localization should also be possible.