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

• US 20130331875A1
• Filed: 03/15/2013
• Published: 12/12/2013
• Est. Priority Date: 06/11/2012
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: ROSS, Anthony B., VAN TOL, David J., PRICE, David
• Application Number:
  US13/840,557
• Publication Number:
  US 20130331875A1
• 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 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2017/320089 node location
• 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 and method of use including a signal generator outputting a drive signal having a frequency, an oscillating structure, receiving the drive signal and oscillating at the frequency of the drive signal, a bridge circuit, detecting the mechanical motion of the oscillating structure and outputting a signal representative of the mechanical motion, and a microcontroller receiving the signal output by the bridge circuit, the microcontroller determining an instantaneous frequency at which the oscillating structure is oscillating based on the received signal, and comparing the instantaneous frequency to a known frequency value and estimating a temperature of the oscillating structure based on the comparison.

Claims

1. An ultrasonic surgical apparatus comprising:

a signal generator outputting a drive signal having a frequency;

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

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

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

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

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

4. The apparatus of claim 3, wherein upon exceeding a first temperature a first signal is issued.

5. The apparatus of claim 4, wherein upon exceeded a second temperature a second signal is issued, said second signal being different from the first signal.

6. The apparatus of claim 2, wherein the signal is selected from the group consisting of visual signals, audible signals, tactile signals, and performance inhibiting signals.

7. The apparatus of claim 1, wherein the comparison of the instant frequency to a known frequency is a comparison of resonant frequencies.

8. The apparatus of claim 7, wherein the known frequency is ascertained during a start-up routine of the ultrasonic surgical apparatus.

9. The apparatus of claim 7, wherein the known frequency is ascertained each time the ultrasonic surgical apparatus is powered on.

10. The apparatus of claim 7, wherein the known frequency is set during manufacture.

11. A method of determining the temperature of an ultrasonic surgical apparatus comprising:

generating a drive signal and supplying the drive signal to an oscillating structure;

detecting the mechanical motion of the oscillating structure and generating a signal representative of the mechanical motion;

processing the signal representative of the mechanical motion to determine whether the oscillating structure is at resonance, and if the transducer is at resonance storing the frequency at which the transducer is oscillating in memory; and

comparing the stored frequency to a known frequency to determine the temperature of the oscillating structure.

12. The method of claim 11, further comprising signaling when the oscillating structure has exceeded a pre-set temperature.

13. The method of claim 12, further comprising signaling when the oscillating structure has exceeded at least one of multiple pre-set temperatures.

14. The method of claim 13, wherein upon exceeding a first temperature a first signal is issued.

15. The method of claim 13, wherein upon exceeded a second temperature a second signal is issued, said second signal being different from the first signal.

16. The method of claim 12, wherein the signaling includes issuing a signal selected from the group consisting of visual signals, audible signals, tactile signals, and performance inhibiting signals.

17. The method of claim 11, wherein the known frequency is ascertained during a start-up routine of the ultrasonic surgical apparatus.

18. The method of claim 11, wherein the known frequency is ascertained each time the ultrasonic surgical apparatus is powered on.

19. The method of claim 11, wherein the known frequency is set during manufacture.