Patent ID: 9050627
Filing Date: 2015-06-09
Classification: A61F,B06B

Abstract:
1. A method for determining the voltage-current phase relationship of a piezoelectric phacoemulsification handpiece, said method comprising the steps of: obtaining an analog AC voltage signal corresponding to the operating AC voltage of a piezoelectric handpiece having a driving frequency; obtaining an analog AC current signal corresponding to the operating AC current of the piezoelectric handpiece; producing a digital representation of the AC current signal and the AC voltage signal using an analog detection circuit; correlating a reference amplitude component of the digital representation with a point in time using a master clock, wherein the master clock uses a signal that is faster than the driving frequency of the AC current signal; determining a phase count measurement, wherein the phase count is the number of master clock periods between the reference amplitude component of the AC current signal and the AC voltage signal; and resetting the master clock upon completion of the phase count measurement.