System And Method For Driving An Ultrasonic Handpiece With A Linear Amplifier
AssigneeStryker Corporation
InventorsAdam D. Downey, Neal R. Butler, Scott A. Rhodes
Life of this patent
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Abstract
A control console for a powered surgical tool. The console includes a transformer that supplies the drive signal to the surgical tool. A linear amplifier with active resistors selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.
Claims20
A control console for generating an AC drive signal applied to an ultrasonic handpiece to vibrate a tip of the ultrasonic handpiece, the control console comprising:
- a linear amplifier comprising:
- a transformer including a primary winding having first and second opposed ends and a center tap to which a DC voltage is applied, and including a secondary winding across which the AC drive signal is developed for vibrating the tip of the ultrasonic handpiece;
- a first transistor connected between the first opposed end of the primary winding and a ground;
- a second transistor connected between the second opposed end of the primary winding and the ground;
- and
- a control circuit coupled to the first and second transistors and configured to:
- receive an external control signal corresponding to a target drive signal for the ultrasonic handpiece that is a linear amplification of the external control signal;
- and
- vary a resistance of each of the first and second transistors using the external control signal to generate a first AC voltage across the primary winding that causes the target drive signal to develop across the secondary winding.
A method for generating an AC drive signal applied to an ultrasonic handpiece to vibrate a tip of the ultrasonic handpiece using a linear amplifier including a transformer, a first transistor, and a second transistor, the transformer including a primary winding having first and second opposed ends and a center tap to which a DC voltage is applied and a secondary winding across which the AC drive signal is developed for vibrating the tip of the ultrasonic handpiece, the first transistor connected between the first opposed end of the primary winding and a ground, and the second transistor connected between the second opposed end of the primary winding and the ground, the method comprising:
- receiving an external control signal corresponding to a target drive signal for the ultrasonic handpiece that is a linear amplification of the external control signal;
- and
- varying a resistance of each of the first and second transistors using the external control signal to generate a first AC voltage across the primary winding that causes the target drive signal to develop across the secondary winding.
Dependencies are inferred from the claim text.