Patent ID: 7625388

Claim:
A method of controlling a surgical system, the surgical system having an ultrasound handpiece, the ultrasound handpiece having a cutting tip for cutting tissue, the method comprising the steps of: establishing a threshold power level; monitoring a load on the cutting tip of the ultrasound handpiece by monitoring a voltage and a current drawn by the handpiece during a non-zero sense power interval, the sense power interval being between cutting power intervals; comparing the amount of power drawn by the handpiece and the threshold power level; if necessary, adjusting an amount of power delivered to the cutting tip of the ultrasound handpiece if the power drawn by the handpiece exceeds the threshold power level by adjusting an amplitude or stroke of the output of the ultrasound handpiece; establishing a threshold temperature; monitoring a pressure in an irrigation line to the handpiece; calculating a rate of flow of the irrigation fluid; determining a heat absorption capacity for the calculated rate of flow of irrigation fluid; determining a temperature of an eye based on the determined heat absorption capacity and an amount of power being supplied to the ultrasound handpiece; comparing the determined temperature of the eye to the threshold temperature; and if necessary, adjusting the amount of power delivered to the cutting tip of the ultrasound handpiece based on the comparison of the determined and threshold temperatures.