An apparatus comprising: a handpiece having a needle and electrical means for ultrasonically vibrating said needle power source means for providing pulsed electrical power to the handpiece electrical means input means for enabling an operator to select an amplitude of the electrical pulses means for providing fluid from the handpiece needle and control means for controlling power supplied to the handpiece during a surgical procedure conducted in a surgical environment, said control means controlling power supplied by applying power during at least one modulated pulsed energy period, said modulated pulsed energy period comprising a relatively high energy pulse sufficient to induce transient cavitation within the surgical environment, followed by a relatively low energy nonzero amplitude pulse.
