Ultrasonic frequency synthesizer for phaco surgery

DETAILED DESCRIPTION An ultrasonic frequency synthesizer for a phaco surgery handpiece in accordance with the present invention generally includes means for storing a plurality of sets of digital information with each set comprising a specific frequency.
Means are provided for selecting one of the sets of digital information, and additionally, means are provided for changing the frequency corresponding to the selected set of digital information.
These two means provide for two methods, used in combination, to extend the range of the synthesizer.
The means for selecting a set of digital information provides a fine method to change frequency while the means for changing the frequency of a selected set provides a coarse method to change frequency.
In accordance with the design, the number of available frequencies is the product of the available frequencies by each means.
Additional means are provided for converting the changed selected set of digital information into an analog sine wave for driving the phaco surgery handpiece via a power amplifier.
This apparatus is particularly suitable for phaco surgery handpieces.
Because a handpiece can have a resonance at frequencies different from the design frequency, it is desirable to utilize a synthesizer, in accordance with the present invention, such as one having a limited range of frequency output.
A method in accordance with the present invention for generating wave forms for a phaco surgical handpiece generally includes the steps of storing a plurality of sets of digital information with each set corresponding to a different specific frequency.
In order to generate an output of a specific frequency, selected from a set of available frequencies, a method in accordance with the present invention selects a set of digital information in response to a control input corresponding to the resonant frequency of a phaco surgical handpiece.
Thereafter, the selected digital information is read in a manner producing a digital output having a corresponding frequency equal to or lower than the frequency corresponding to the selected set of digital information