SOUND WAVE GENERATOR FOR THERAPEUTIC PURPOSES

This invention relates to a sound wave generator with a variable effective aperture angle according to the electromagnetic principle for therapeutic applications and particularly for the contactless smashing of a concrement situated in the body of a living being. The sound wave generator includes a flat coil and a metallic diaphragm which is insulated with respect to the flat coil. The flat coil includes three separately activatable and concentrically arranged coil sections. The sum of the areas of the inner coil section and the center coil section is equal to the sum of the areas of the central coil section and the outer coil section. By means of the varying activation of the coil sections, the aperture of the shock wave source can be changed so that the focus geometry and the peak pressures can be varied for different applications, particularly kidney and gallbladder lithotrity.