MODEL RELEASED. Lithotripsy treatment. Doctor using a lithotripsy machine to treat a patient's kidney stones. Lithotripsy is a non-invasive technique that uses focused ultrasonic sound waves to break up hard deposits in the body, while leaving surrounding tissues unharmed. Kidney stones are hard deposits of urine salts that can form inside the kidneys, causing pain, urine retention and kidney damage. Once the stone has been pulverised by lithotripsy, the remaining dust is passed in the urine.