Ultrasonic surgical tool system including a tip capable of simultaneous longitudinal and torsional movement and of substantially torsional oscillations

There is provided an ultrasonic tool system comprising an ultrasonic handpiece including at least one driver that, in response to application of an AC drive signal, cyclically expands and contracts, and a tip including opposed proximal and distal ends, the proximal end of the tip being coupled to the at least one driver so that the expansions and contractions of the at least one driver cause longitudinal vibrations at the proximal end of the tip, and a feature between the proximal and distal ends of the tip that converts the longitudinal vibrations present at the proximal end of the tip to vibrations at the distal end of the tip having a longitudinal component and a torsional component; and a control console configured to generate the AC drive signal and apply it to the at least one driver of the ultrasonic handpiece, the AC drive signal having a varying frequency, the frequency being such that the vibrations at the distal end of the tip are substantially torsional.