TEMPERATURE ESTIMATION AND TISSUE DETECTION OF AN ULTRASONIC DISSECTOR FROM FREQUENCY RESPONSE MONITORING

• US 20130331873A1
• Filed: 03/15/2013
• Published: 12/12/2013
• Est. Priority Date: 06/11/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: ROSS, ANTHONY B., VAN TOL, DAVID J., PRICE, DAVID
• Granted Patent: US 11,076,880 B2
• Time in Patent Office: Days
• US Class Current: 606/169
• CPC Class Codes: A61B 17/320092 with additional movable means for clamping or cutting tissue, e.g. with a pivoting jaw
• CPC Class Codes: A61B 2017/0003 of parts of the instruments
• CPC Class Codes: A61B 2017/00075 Motion
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00106 ultrasonic
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2017/320094 additional movable means performing clamping operation
• CPC Class Codes: A61B 2017/320095 with sealing or cauterizing means

Abstract

An ultrasonic surgical apparatus including a first signal generator outputting a drive signal at a predetermined voltage and frequency, a first oscillating structure receiving the drive signal and oscillating at the frequency of the drive signal, and a bridge circuit, detecting the mechanical motion of the first oscillating structure and outputting a signal representative of the mechanical motion. The apparatus also includes a second oscillating structure integrally formed within a portion of the first oscillating structure, the second oscillating structure outputting an electrical signal, and a microcontroller receiving the signal output by the bridge circuit and output by the second oscillating structure, the microcontroller determining an instantaneous frequency at which the first oscillating structure is oscillating based on the received signal, comparing the electrical signal from the second oscillating structure with a known signal value and determining the temperature of the second oscillating structure based on a the comparison.

Claims

1. An ultrasonic surgical apparatus comprising:

a first signal generator outputting a drive signal at a predetermined voltage and frequency;

a first oscillating structure, receiving the drive signal and oscillating at the frequency of the drive signal;

a bridge circuit, detecting the mechanical motion of the first oscillating structure and outputting a signal representative of the mechanical motion;

a second oscillating structure integrally formed within a portion of the first oscillating structure, the second oscillating structure outputting an electrical signal; and

a microcontroller receiving the signal output by the bridge circuit and output by the second oscillating structure, the microcontroller determining an instantaneous frequency at which the first oscillating structure is oscillating based on the received signal, comparing the electrical signal from the second oscillating structure with a known signal value and determining the temperature of the second oscillating structure based on a the comparison.

2. The apparatus of claim 1 wherein the second oscillating structure is an accelerometer.

3. The apparatus of claim 2, wherein the accelerometer outputs a variable electrical signal depending upon the magnitude and frequency of a mechanical force applied to the accelerometer.

4. The apparatus of claim 3, wherein the known signal value is determined during a start-up routine.

5. The apparatus of claim 3, wherein the known signal value is ascertained each time the ultrasonic surgical apparatus is powered on.

6. The apparatus of claim 3, wherein the known signal value is set during manufacture.

7. The apparatus of claim 1, further comprising an indicator signaling that the oscillating structure has exceeded a pre-set temperature.

8. The apparatus of claim 1, further comprising a indicator signaling that the oscillating structure has exceeded at least one of multiple pre-set temperatures.

9. The apparatus of claim 8, wherein upon exceeding a first temperature a first signal is issued.

10. The apparatus of claim 9, wherein upon exceeded a second temperature a second signal is issued, said second signal being different from the first signal.

11. The apparatus of claim 7, wherein the signal is selected from the group consisting of visual signals, audible signals, tactile signals, and performance inhibiting signals.

12. The apparatus of claim 1, wherein the comparison of the signal from the second oscillating structure to a known signal occurs when the microcontroller determines that signal output from the bridge circuit indicates that the first oscillating structure is oscillating at a resonance frequency of the first oscillatory structure.

13. The apparatus of claim 1, wherein the first oscillating structure includes one or more of a transducer, a waveguide, or a blade.

14. The apparatus of claim 13, wherein the second oscillating structure is integrally formed within the blade.

15. The apparatus of claim 13, further comprising multiple second oscillating structures.

16. The apparatus of claim 15, wherein the multiple second oscillating structures include at least one integrally formed in the blade and at least one integrally formed in the waveguide.

17. The apparatus of claim 15, wherein the microcontroller compares the signals returned from each of the multiple second oscillating structures to determine which portion of the first oscillating structure is being heated.

18. The apparatus of claim 15, wherein the microcontroller compares each of the signals returned from the multiple second oscillating structures to the known signal value to determine if any of the portions of the first oscillating structure are being heated.

19. The apparatus of claim 1, further comprising a second signal generator.

20. The apparatus of claim 19, wherein the signal produced by the second signal generator causes the second oscillating structure to oscillate at its resonance frequency.

21. The apparatus of claim 20, wherein the signals generated by the first and second signal generators are applied to the first and second oscillating structure simultaneously.

22. The apparatus of claim 21, wherein a return signal from the second oscillating structure is monitored to confirm that the second oscillating structure is oscillating at the second oscillating structure'"'"'s resonance frequency.

23. The apparatus of claim 22, wherein the microcontroller causes the second signal generator to adjust its signal to maintain the second oscillating structure oscillating at the second oscillating structure'"'"'s resonance frequency.

24. The apparatus of claim 23, wherein the microcontroller compares an initial signal generated by the second signal generator to a second signal to determine the temperature of the second oscillating structure.

25. The apparatus of claim 24, wherein the apparatus comprises multiple second oscillating structures, and the microcontroller can determine the temperature of the multiple second oscillating structures.