The lithotripsy machine generates waves of turbulence or pressure in the air. These can be passed through the body and will shatter urinary stones into tiny fragments that can easily be passed in the urine.
A lithotripsy procedure may be necessary to treat a stone or group of stones in your urinary tract.
These stones may lie in the kidney or in the tube (ureter) that brings the urine from the kidney to the bladder. Stones are made from various materials that crystallise out of solution. They start as tiny grains and grow to become visible on the x-ray and cause you symptoms, such as pain, infection or blood in the urine.
You can get more details about lithotripsy at the Newcastle Urology website.