Patent ID: 8092470

Claim:
An apparatus for crushing a calculus, the apparatus comprising: a holding part adapted to surround and catch the calculus so as to fixedly hold and support the calculus; a crushing part which has a first end, a second end, and a head portion comprising an empty loop shape which is surrounded by the holding part, the crushing part being adapted to rotate and crush the calculus supported by the holding part; a sheath for containing the crushing part in a manner such that the first and second ends extend through the sheath and that the head portion of the crushing part is protrudable from a head of the sheath; and a rotation input part for rotating the crushing part and adjusting a rotation speed, thereof to vary a centrifugal force applied to the head portion of the crushing part so as to adjust an amount of protrusion of the crushing part measured from the head of the sheath to the head portion of the crushing part, wherein a radius of rotation of the crushing part with respect to a rotation axis thereof increases or decreases in accordance with an increase or decrease in the rotation speed of the crushing part; and the head portion of the crushing part is adapted to move relative to the holding part in a direction along the rotation axis.