Patent ID: 8454639

Claim:
A percutaneous surgical instrument comprising: an actuator for generating vibrations at ultrasonic frequencies; a horn coupled to said actuator for amplifying the actuator vibration; an ultrasonically driven fixed probe attached to said horn, said fixed probe having an end for engaging calculi and introducing the ultrasonic frequencies thereto; an ultrasonically driven floating probe disposed concentric to and under said fixed probe, said floating probe being slidable along said fixed probe and having an end for simultaneously introducing ultrasonically driven low-frequency impact with the calculi; an ultrasonically driven free mass, disposed between said horn and said floating probe for oscillating therebetween, in response to actuator ultrasonic vibration, for causing ultrasonically driven low frequency impact with the floating probe which, in turn, introduces the low frequency impact with the calculi; a collar for receiving impacts from said free mass, said collar coupled to said floating probe at a proximal end thereof, said collar being disposed internal to a proximal end of said fixed probe and being slidable along said fixed probe; and a generator for driving said actuator at desired power levels, frequencies, pulse cycles and duty cycles in order to both provide the ultrasonic frequency introduced by said fixed probe and the oscillations of the low frequency impacts.