The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 2015
Filed:
Sep. 02, 2011
Jon D. Jacobson, Irvine, CA (US);
Jon D. Jacobson, Irvine, CA (US);
Abbott Medical Optics Inc., Santa Ana, CA (US);
Abstract
A method for determining the voltage current phase relationship of a piezoelectric phacoemulsification handpiece generally includes the steps of obtaining an analog AC voltage signal corresponding to the operating AC voltage of a piezoelectric handpiece along with an analog AC current signal corresponding to the operating AC current of the piezoelectric handpiece. Using reference detection circuits, a digital voltage signal and a digital current signal is produced. A synchronous sample clock is taken that has a frequency that is 2times faster than the frequency of the operating ultrasonic handpiece (i.e., driving frequency), where N is the number of digital bits allocated to the sample clock. This clock measures the time between onsets of a voltage and current cycle. This time value equates to the phase time delta between the two signals. Dividing the synchronous sample clock to obtain the driving frequency ensures the signals are synchronous.