Patent ID: 6662127
Filing Date: 2003-12-09
Classification: A61B

Abstract:
A method for detecting presence of a blade in an ultrasonic surgical system, comprising the steps of:applying a drive signal to a hand piece without the blade attached using an ultrasonic generator; performing multiple frequency sweeps across a predetermined frequency range; storing a resonance frequency value, a minimum impedance value, and a phase margin value of the hand piece across the predetermined frequency range at the minimum impedance value of the hand piece; determining whether the resonance frequency value, the phase margin value and the minimum impedance value of the hand piece are within acceptable limits; if the resonance frequency value, the phase margin value and the minimum impedance value of the hand piece are within acceptable limits, connecting the blade to the hand piece and re-exciting the hand piece/blade with the drive signal across the predetermined frequency range; storing the resonance frequency value and the phase margin value of the hand piece/blade across the predetermined frequency range at the minimum impedance value of the hand piece/blade; and if the resonance frequency value and the minimum impedance value of the hand piece/blade are within acceptable limits, displaying a message on a liquid crystal display of the generator.