The Danish Extracorporeal Lithotripter
A Danish second-generation extracorporeal shock wave lithotripter (Nitech A/S) will be presented.
The patient is treated in the prone position. A water-filled ellipsoid with a spark gap in the one focal point is placed with a water-tight cushion sealing to the patient on the back. The ellipsoid is suspended in a fully balanced system which can be fixed in any position by hydraulic brakes.
The focal zone of the generated shock waves is placed exactly in the stone area. The kidney and the echo-producing stone are visualized by dynamic ultrasonic scanning. A 3.5 MHz focused ultrasound transducer is placed in the wall of the ellipsoid, and the scanning motion is produced by an oscillating mirror placed in the center of the ellipsoid which transmits the ultrasonic beam into the patient.
The new lithotripter is intended as an option to a standard urological ultrasound scanner which can produce abdominal, transrectal, transurethral, transvaginal scans as well as all ultrasonically guided interventional procedures.