Method of controlling a surgical system based on a load on the cutting tip of a handpiece

• US 8,974,412 B2
• Filed: 08/03/2012
• Issued: 03/10/2015
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Novartis Ag
• Inventors: Boukhny, Mikhail, Gordon, Raphael, Morgan, Michael D., Yadlowsky, Ann
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US13/565,875
• Publication Number:
  US 20120296264A1
• Time in Patent Office: 949 Days
• Field of Search: 604 19- 22, 604/118, 604/119, 606/406, 606 10- 12, 606/167, 606169-171, 600/437, 600/439, 600/446, 600/452, 601/2
• US Class Current: 604/119
• CPC Class Codes: A61B 17/320068 using mechanical vibrations, e.g. ultrasonic A61B17/22012 takes precedence; dental tooth drilling devices operated by vibration A61C3/03; removing intra-ocular material using mechanical vibrations A61F9/00745
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/0003 of parts of the instruments
• CPC Class Codes: A61B 2017/00973 pedal-operated
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61F 9/00745 using mechanical vibrations, e.g. ultrasonic
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 3/0202 with electronic control means or interfaces
• CPC Class Codes: A61M 3/0208 before use
• CPC Class Codes: A61M 3/0216 Pressure
• CPC Class Codes: A61M 3/022 Volume; Flow rate
• CPC Class Codes: A61M 3/0258 by means of electric pumps

Abstract

A surgical system that is able to sense the onset of an occlusion or other surgical event as well as the instant an occlusion breaks. To help avoid overheating of the tip, the system determines an approximate temperature of the eye using an irrigation flow rate and reduces the power to the handpiece automatically if an overheating situation is predicted. Alternatively or in addition, the system monitors the power drawn by the handpiece, which is indicative of the cutting load on the tip, and automatically adjusts the power or stroke of the tip to compensate for increased loads on the tip.

Claims

1. A method of controlling a surgical system, the surgical system having an ultrasound handpiece, the ultrasound handpiece having a cutting tip for cutting tissue, the method comprising the steps of:

establishing a threshold power level;

monitoring a load on the cutting tip of the ultrasound handpiece by monitoring a voltage and a current drawn by the handpiece during a non-zero sense power interval, the sense power interval being between cutting power intervals;

comparing the amount of power drawn by the handpiece and the threshold power level; and

adjusting an amount of power delivered to the cutting tip of the ultrasound handpiece if the power drawn by the handpiece exceeds the threshold power level by adjusting an amplitude or stroke of the output of the ultrasound handpiece;

determining a rate of change of a first operating parameter of the surgical system;

determining a stage of occlusion based on the rate of change of the first operating parameter; and

adjusting an amount of power delivered to the cutting tip of the ultrasound handpiece based on the determined stage of occlusion.

2. The method of claim 1, determining the rate of change of the first operating parameter comprising determining a rate of change of aspiration vacuum.

3. The method of claim 2, wherein determining the stage of occlusion is based on the rate of change determinations of the first operating parameter and the second operating parameter.

4. The method of claim 1, determining the rate of change of the first operating parameter comprising determining a rate of change of an irrigation pressure.

5. The method of claim 1, further comprising determining a rate of change of the second operating parameter of the surgical system.

6. The method of claim 1, the first operating parameter being aspiration vacuum, and the second operating parameter comprising irrigation pressure.

7. The method of claim 1, determining the stage of occlusion comprising identifying an onset or preliminary indication of occlusion.

8. The method of claim 1, further comprising determining a rate of change of a second operating parameter of the surgical system, determining the stage of occlusion comprising determining a stage of occlusion being based on the determinations involving the first and second operating parameters, the first operating parameter comprising an irrigation pressure, the second operating parameter comprising aspiration vacuum, the onset of occlusion being identified by increasing vacuum and irrigation pressures.

9. The method of claim 1, determining the stage of occlusion comprising identifying a pre-occlusion condition.

10. The method of claim 9, the first operating parameter comprising aspiration vacuum, the pre-occlusion condition being identified by an increasing aspiration vacuum.

11. The method of claim 10, the aspiration vacuum increasing at a slower rate following the pre-occlusion condition than during a period of time between an onset of occlusion and the pre-occlusion condition.

12. The method of claim 1, further comprising

determining a rate of change of a second operating parameter of the surgical system,

determining the stage of occlusion being based on the first and second operating parameters, the first operating parameter being an irrigation pressure, the second operating parameter being aspiration vacuum.

13. The method of claim 12, the pre-occlusion condition being identified by an increasing aspiration vacuum and a substantially constant irrigation pressure.

14. The method of claim 12, the aspiration vacuum during the pre-occlusion condition increasing at a slower rate than during a period of time between an onset of occlusion and the pre-occlusion condition.

15. The method of claim 1, determining the stage of occlusion comprising identifying a full occlusion.

16. The method of claim 1, further comprising determining a rate of change of a second operating parameter of the surgical system, determining the stage of occlusion being based on the determinations involving the first and second operating parameters, the first operating parameter comprising an irrigation pressure, the second operating parameter comprising a aspiration vacuum, the break being identified by a decreasing aspiration vacuum and a decreasing irrigation pressure.

17. The method of claim 16, the first operating parameter comprising aspiration vacuum, the recovery being identified by a slowing of a rate of decrease of the aspiration vacuum.

18. The method of claim 16, the first operating parameter comprising an irrigation pressure, the recovery being identified by a slowing of a rate of decrease of the irrigation pressure.

19. The method of claim 18, further comprising

determining a rate of change of a second operating parameter of the surgical system,

determining a stage of occlusion being based on the determinations involving the first and second operating parameters, the first operating parameter comprising an irrigation pressure, the second operating parameter comprising aspiration vacuum, the recovery period having a substantially constant aspiration vacuum and a substantially constant irrigation pressure.

20. The method of claim 1, wherein determining the stage of occlusion further comprises:

identifying an onset of an occlusion, a pre-occlusion condition following the onset,

a full occlusion following the pre-occlusion condition, a break of the full occlusion;

or

a recovery following the break.

21. The method of claim 1, adjusting power comprising adjusting a duty cycle of the output of the ultrasound handpiece.

22. The method of claim 1, adjusting power comprising adjusting an amplitude or stroke of the output of the ultrasound handpiece.