Abstract: A spark gap unit that is easy to manufacture and significantly lighter than previously used spark gap units for generating underwater shock waves, particularly for non-invasive lithotrispy, has an internal conductor with an inner electrode, an insulation which at least partially envelops the internal conductor, and an external conductor with a bow and an outer electrode. The internal conductor is significantly shorter than the external conductor, and the external conductor at the rearward end of the spark gap unit projects beyond the internal conductor. The internal conductor, the insulation, and the external conductor are coaxially arranged. An outside diameter of the internal conductor is relatively small in comparison to an inside diameter of the external conductor. The spark gap unit has a hollow space inside the insulation, this hollow space being open in the direction of a rearward end of the spark gap unit.

Abstract: A lithotripter includes a therapeutic head provided with a source for focusing shockwaves in a focal point on a first axis; an ultrasonic transducer having an axis for imaging an area in a patient in which shockwaves are to be focussed is connected to the therapeutic head for movement in relation to the head in isocentric relation to that focal point such that two axes intersect in that focal point, independently form a variable angular orientation of the axes to each other.

Abstract: A lithotripter includes a therapeutic head with a source for the production and focusing of shockwaves into the body of a patient and is mounted such that a center axis of the head is forced to move and remain on the surface of a cone whose apex point coincides with the focus of the therapeutic head, external to the head, so as to obtain isocentric motion of the head vis-a-vis that focus, even if that focus is made to be positioned in the body of the patient and an ultrasonic transducer is isocentrally mounted on the therapeutic head.

Abstract: A lithotripter having a central housing for equipment pertaining to shockwave generation, further having a focusing equipment head movably connected thereto, is improved by an up and down sliding patient rest having a central horizontally positioned cantilever mounted segment with a closure as treatment window; a headrest is removably attached to one side of the central segment; and leg support structure such a rest segment with extension or a miction pan or leg support troughs is removably attached to the opposite side of the central segment.