Patent ID: 11877953
Assignee: JOHNSON & JOHNSON SURGICAL VISION, INC.
Field: Medical technology (Instruments)
Classification: CPC A  G  H | IPC A  G  H

Claim 10:
11. A phacoemulsification method comprising:
inserting a needle of a phacoemulsification probe into a lens capsule of a human eye, the probe also including a horn in which the needle is mounted;
generating a drive signal to drive a vibration of a piezoelectric actuator having a resonant frequency, the piezoelectric actuator vibrating the horn and the needle;
measuring a phase difference between: a voltage across the piezoelectric actuator; and a current flowing through the piezoelectric actuator in response to the drive signal, wherein the measuring of the phase difference includes performing a multiplication of the voltage with a reference signal yielding voltage resultant signals; and performing a multiplication of the current with the reference signal yielding current resultant signals; and
adjusting a frequency of the drive signal so as to minimize the measured phase difference, whereby the piezoelectric actuator vibrates at the resonant frequency.