Apparatus and method for creating, maintaining, and controlling a virtual electrode used for the ablation of tissue

• US 9,770,282 B2
• Filed: 07/24/2007
• Issued: 09/26/2017
• Est. Priority Date: 02/22/1995
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hoey, Michael F., Christopherson, Mark A., Goetz, Steven M.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US11/782,134
• Publication Number:
  US 20080015563A1
• Time in Patent Office: 3,717 Days
• Field of Search: 606 27- 34, 606 41, 606 42, 607101-105
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/1213 creating an arc
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/1417 Ball
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2018/1475 : Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration

Abstract

An apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current. An apparatus in accord with the present disclosure includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present disclosure includes delivering a conductive fluid to a predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and/or the fluid flow in response to the measured parameters.

Claims

1. A surgical apparatus to deliver radio frequency power and a fluid via a surgical instrument to treat tissue, the apparatus comprising:

a radio frequency power source to provide the radio frequency power at a power level; and

a controller control means configured to control a flow rate of the fluid based upon the power level of the radio frequency power.

2. The apparatus of claim 1, wherein:

the flow rate is controlled by use of an equation.

3. The apparatus of claim 1, wherein:

the flow rate is controlled by use of a linear relationship.

4. The apparatus of claim 1, wherein:

the flow rate is controlled by use of a step relationship.

5. The apparatus of claim 1, wherein:

the flow rate is controlled by use of a look-up table.

6. The apparatus of claim 1, wherein:

the flow rate used at the power level is stored in a memory.

7. The apparatus of claim 1, wherein:

the control means controller comprises a microprocessor.

8. The apparatus of claim 1 further comprising:

a pump; and

the control means controller is configured to control the flow rate of the fluid using the pump.

9. The apparatus of claim 8, wherein:

the pump is used to convey the fluid through a fluid line.

10. The apparatus of claim 8, wherein:

the pump comprises a syringe pump.

11. The apparatus of claim 8, wherein:

the pump comprises a flexible tube pump.

12. The apparatus of claim 8, further comprising:

a housing; and

the pump and the radio frequency power source are joined with the housing.

13. The apparatus of claim 8, wherein:

the pump is configured to provide the flow rate in a range between and including 0.1 cubic centimeters per minute to 10 cubic centimeters per minute.

14. The apparatus of claim 1, wherein:

the radio frequency power source comprises a radio frequency generator.

15. The apparatus of claim 1, wherein:

the radio frequency power source is configured to provide the radio frequency power in a power range between and including 0.1 watts to 200 watts.

16. The apparatus of claim 1, wherein:

the radio frequency power source is configured to provide the radio frequency power at the power level in a frequency range between and including 350 kHz to 700 kHz and a resistive load range between and including 10 ohms to 500 ohms.

17. The apparatus of claim 1, wherein:

the fluid comprises at least one of an electrically conductive fluid and an electrolytic fluid.

18. The apparatus of claim 1, wherein:

the fluid comprises at least one of an electrically conductive solution and an electrolytic solution.

19. The apparatus of claim 1, wherein:

the fluid is provided from a fluid source comprising a container.

20. The apparatus of claim 1, wherein:

the control means controller is further configured to identify the surgical instrument.

21. The apparatus of claim 1 further comprising:

a memory; and

at least one operating parameter for the surgical instrument is stored in the memory.

22. The apparatus of claim 1, wherein:

the control means controller is further configured to communicate with a memory or a microchip of the surgical instrument to identify the surgical instrument.

23. The apparatus of claim 1, wherein:

the control means controller is further configured to communicate with a memory or a microchip of the surgical instrument to obtain at least one operating parameter for the surgical instrument from the memory or the microchip.

24. The apparatus of claim 1, wherein:

the control means controller is further configured to limit a use of the surgical instrument.

25. The apparatus of claim 24, wherein:

the control means controller is configured to limit a use of the surgical instrument based on at least one of a total number of times of use, a total amount of time of use and a time period of use.