Systems and methods for ultrasonic power measurement and control of phacoemulsification systems
US9050627B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 2, 2011 |
| Grant date | Jun 9, 2015 |
| Priority date | — |
| Expiry date | Jan 14, 2033 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B2201/76
- WIPO fieldMedical technology
- WIPO sectorInstruments
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 2N times 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.