Patent attributes
An ultrasonic surgical system utilizes a digital control system to generate ultrasonic drive current for transducers that are located in a hand piece and are attached to a surgical scalpel or blade so as to vibrate the blade in response to the current. The digital control includes a digital signal processor (DSP) or microprocessor; a direct digital synthesis (DDS) device; a phase detection logic scheme, a control algorithm for seeking and maintaining resonance frequency; and design scheme that allows to regulate current, voltage, and power delivered to an ultrasonic device. The system allows the power versus load output curve to be tailored to a specific hand piece; the components of the digital system are much less sensitive to temperature variations; and the digital system provides increased flexibility in locating the resonance frequency of the blade and running diagnostic tests.
