The lithotripsy is a treatment of the urinary stones which consists in fragmenting them though shock waves generated by ultrasound or waves transmitted by water. They can also be fragmented or cut into mini fragments with an instrument or a laser mounted by the natural tracts at the end of a special probe.
The lithotripsy of a urinary stone through endoscopy
The endoscopy tube is mounted through the urethra then the bladder and the ureter, until the stone. It is fragmented either with a cutting pliers or a probe that sends ultrasounds, electro-hydraulic waves or a laser beam.
Now this can be done in a special bathtub:
Water transmits shock waves (electro-hydraulic, piezo-electric or electromagnetic) without the penetration of any instrument. The stones must not be too large in order to be evacuated by the natural tracts and not be calcified otherwise they are resistant to the waves.