Method for detecting transverse mode vibrations in an ultrasonic hand piece/blade
First Claim
1. A method for detecting transverse vibrations in an ultrasonic hand piece/blade, comprising:
- applying a drive signal to the hand piece/blade using an ultrasonic generator;
monitoring a change over time of the drive signal;
measuring a level of an output signal from a filter located in the ultrasonic generator;
comparing the output signal to a predetermined level; and
if the output signal exceeds the predetermined level, displaying a message on a liquid crystal display of the generator to indicate that the ultrasonic hand piece/blade contains transverse vibrations.
2 Assignments
0 Petitions
Accused Products
Abstract
A method for detecting transverse mode vibrations in an ultrasonic hand piece/blade for determining the existence of unwanted vibration in the hand piece/blade. A tracking filter centered at the drive frequency of the generator, is used to monitor the drive frequency of the ultrasonic generator and attenuate the drive signal when it exceeds a predetermined level. The tracking filter has a wide pass band. Alternatively, a tracking filter having a pass band which is divided into several regions is used to avoid other longitudinal resonances, such as a resonance at a second harmonic, or other spectral features that would otherwise detract from the tracking accuracy of the filter.
949 Citations
22 Claims
-
1. A method for detecting transverse vibrations in an ultrasonic hand piece/blade, comprising:
-
applying a drive signal to the hand piece/blade using an ultrasonic generator;
monitoring a change over time of the drive signal;
measuring a level of an output signal from a filter located in the ultrasonic generator;
comparing the output signal to a predetermined level; and
if the output signal exceeds the predetermined level, displaying a message on a liquid crystal display of the generator to indicate that the ultrasonic hand piece/blade contains transverse vibrations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
tracking the drive signal to determine whether a significant amount of off-frequency transverse mode vibrations have occurred.
-
-
3. The method of claim 2, wherein said tracking step is performed using at least one of a notch filter and a band pass filter.
-
4. The method of claim 3, wherein the at least one of the notch filter and the band pass filter are one of an analog filter and a digital filter.
-
5. The method of claim 4, wherein the analog filter is a switching-capacitive filter and the digital filter is one of a finite impulse response filter and an infinite impulse filter.
-
6. The method of claim 1, wherein said tracking is performed via at least one of a notch filter and a band pass filter.
-
7. The method of claim 6, wherein the notch filter and the band pass filter are one of an analog filter and a digital filter.
-
8. The method of claim 7, wherein the analog filter is a switching-capacitive filter and the digital filter is one of a finite impulse response filter and an infinite impulse filter.
-
9. The method of claim 1, wherein the predetermined level is greater than zero.
-
10. The method of claim 1, wherein the step of displaying the message comprises the step of:
displaying a “
Blade Has Transverse Modes”
message on the liquid crystal display.
-
11. The method of claim 1, wherein the drive signal is applied at a frequency of approximately 55.5 kHz and a current in the range of approximately 200 to 400 ma.
-
12. A method for detecting transverse vibrations in an ultrasonic hand piece/blade, comprising:
-
applying a drive signal to the hand piece/blade using an ultrasonic generator;
monitoring a change with respect to load of a rms value of an output signal from a filter;
comparing the change with respect to load of the rms value output from the filter to a predetermined level; and
displaying a message on a display, if the rms value exceeds the predetermined level to indicate that the ultrasonic hand piece/blade contains transverse vibrations. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
tracking the drive signal to determine whether a significant amount of off-frequency transverse mode vibrations have occurred.
-
-
14. The method of claim 13, wherein said tracking step is performed using at least one of a notch filter and a band pass filter.
-
15. The method of claim 14, wherein the notch filter and band pass filter are one of an analog filter and a digital filter.
-
16. The method of claim 13, wherein the analog filter is a switching-capacitive filter and the digital filter is one of a finite impulse response filter and an infinite impulse filter.
-
17. The method of claim 12, wherein said tracking step is performed using at least one of the notch filter and the band pass filter.
-
18. The method of claim 17, wherein the notch filter and the band pass filter are one of an analog filter and a digital filter.
-
19. The method of claim 18, wherein the analog filter is a switching-capacitive filter and the digital filter is one of a finite impulse response filter and an infinite impulse filter.
-
20. The method of claim 12, wherein the predetermined level is greater than zero.
-
21. The method of claim 12, wherein the step of displaying the message comprises the step of:
displaying a “
Blade Has Transverse Modes”
message on the liquid crystal display.
-
22. The method of claim 12, wherein the drive signal is applied at a frequency of approximately 55.5 kHz and a current in the range of approximately 200 to 400 ma.
Specification