Method for driving an ultrasonic system to improve acquisition of blade resonance frequency at startup
First Claim
1. A method for improving acquisition of resonance at start up of an end effector connected to an ultrasonic system, comprising the steps of:
- exciting the end effector using a generator;
checking to determine whether the resonance has been captured;
if the resonance is not captured, progressively exciting the end effector at a higher drive currents/voltages level during a plurality of sweeps and repeating the checking step subsequent to repeating the progressively exciting step; and
if the resonance of the end effector is captured, ending the method.
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Abstract
The ability of an ultrasonic system to sweep and lock onto a resonance frequency of a blade subjected to a heavy load at startup is improved by applying a high drive voltage or a high drive current while systematically increasing the level of the applied signal. Increasing the drive signal to the hand piece results in an improved and more pronounced “impedance spectrum.” That is, under load, the increased drive signal causes the maximum phase margin to become higher and the minimum/maximum impedance magnitude to become more pronounced. Increasing the excitation drive signal to the hand piece/blade at startup significantly alleviates the limiting factors associated with ultrasonic generators, which results in an increase of the maximum load capability at startup.
463 Citations
8 Claims
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1. A method for improving acquisition of resonance at start up of an end effector connected to an ultrasonic system, comprising the steps of:
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exciting the end effector using a generator; checking to determine whether the resonance has been captured; if the resonance is not captured, progressively exciting the end effector at a higher drive currents/voltages level during a plurality of sweeps and repeating the checking step subsequent to repeating the progressively exciting step; and if the resonance of the end effector is captured, ending the method. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification