Patent ID: 8195286

Claim:
A phacoemulsification apparatus comprising: a phacoemulsification handpiece having a needle, and an electric circuit having one or more piezoelectric transducers, having an electrical load, for ultrasonically vibrating said needle; a power source configured to provide a pulse of electrical power to the handpiece having a pulse duty cycle, a drive voltage, and a frequency that causes the needle to be driven along its longitudinal axis; an input enabling a surgeon to select an ultrasonic pulse amplitude and the pulse duty cycle supplied to the handpiece; a computer programmed to adjust the power in response to the selected pulse amplitude and to adjust the pulse duty cycle in response to the selected pulse duty cycle, wherein said computer is enabled to control the power source to provide the pulse of electrical power at a surgeon selectable rate of between about 25 and about 2000 pulses per second, further wherein the computer is configured to adjust the drive voltage of the electrical power in response to a change in the electrical load of the one or more piezoelectric transducers during operation.