Variable resistor jaw

• US 8,469,956 B2
• Filed: 07/21/2008
• Issued: 06/25/2013
• Est. Priority Date: 07/21/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: McKenna, Nicole, Wham, Robert H.
• Primary Examiner(s): Peffley, Michael
• Assistant Examiner(s): GIULIANI, THOMAS ANTHONY
• Application Number:
  US12/176,679
• Publication Number:
  US 20100016857A1
• Time in Patent Office: 1,800 Days
• Field of Search: 606/38, 606/48, 606 50- 52, 600/393
• US Class Current: 606/51
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 2018/00077 high, i.e. electrically conducting
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00178 Electrical connectors
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00827 Current
• CPC Class Codes: A61B 2018/00869 Phase
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/00892 Voltage
• CPC Class Codes: A61B 2018/00904 Automatic detection of target tissue

Abstract

A bipolar forceps for sealing tissue includes an end effector assembly having opposing first and second jaw members each having a proximal end and a distal end. A first electrically conductive surface having two or more conductive sealing plates and a dielectric layer is operably coupled to the first jaw member. Each sealing plate is connected to a reactive element and positioned along the first electrically conductive surface from the proximal end to the distal end. The reactive elements of the sealing plates have different impedances. A second electrically conductive surface having at least one conductive sealing plate is operably coupled to the second jaw member. Each electrically conductive surface on the jaw members connects to a source of electrosurgical energy such that the sealing plates are capable of conducting energy through tissue held therebetween to effect a tissue seal.

Claims

1. A bipolar forceps for sealing tissue, comprising:

an end effector assembly having opposing first and second jaw members each having a proximal end and a distal end and being movable relative to one another to grasp tissue therebetween;

a first electrically conductive surface having at least two conductive sealing plates and a dielectric layer operably coupled to the first jaw member and forming an inner-facing surface thereof, each of the at least two conductive sealing plates connected to at least one reactive element, the at least two conductive sealing plates including a first sealing plate and a second sealing plate, the first sealing plate being positioned along the first electrically conductive surface proximal to the second sealing plate, the at least one reactive element connected to the first sealing plate having a different impedance than the at least one reactive element connected to the second sealing plate; and

a second electrically conductive surface having at least one conductive sealing plate operably coupled to the second jaw member and forming an inner-facing surface thereof,

wherein each of the first and second electrically conductive surfaces is adapted to connect to a source of electrosurgical energy,

wherein a first impedance to tissue is formed by the reactive element of the first sealing plate and a second impedance to tissue is formed by the reactive element of the second sealing plate, wherein the first impedance is greater than the second impedance thereby driving more current through the distal end of the first electrically conductive surface, such that the first and second electrically conductive surfaces are capable of conducting energy through tissue held therebetween to effect a tissue seal.

2. The bipolar forceps of claim 1 wherein the at least one reactive element is at least one of a capacitor, resistor, variable resistor, resistor series, capacitor series, and variable resistor network.

3. The bipolar forceps of claim 1 wherein the dielectric layer is disposed between adjacent sealing plates along a length of the first jaw member.

4. The bipolar forceps of claim 3, wherein the dielectric layer separates and electrically isolates adjacent sealing plates along the length of the first jaw member.

5. The bipolar forceps of claim 1 wherein the dielectric layer varies in thickness along, the length of the jaw member.

6. The bipolar forceps of claim 1 wherein the dielectric layer is composed of a shape memory material.

7. The bipolar forceps of claim 1 wherein the dielectric layer acts as a stop member to regulate distance between jaw members.

8. The bipolar forceps of claim 1 wherein the electrically conductive surfaces have stop members.

9. The bipolar forceps of claim 1 further comprising:

a sensor which measures at least one tissue property and configures the at least one reactive element based on the at least one tissue property to effectively seal tissue.

10. The bipolar forceps of claim 9 wherein the at least one tissue property measured by the sensor includes at least one of tissue thickness, tissue hydration level, tissue impedance, tissue density, tissue type, voltage, current, impedance, and phase.

11. The bipolar forceps of claim 9 further comprising a feedback loop for real time adjustment of the at least one reactive element based on the at least one tissue property.

12. The bipolar forceps of claim 9 wherein the at least one reactive element is at least one of a capacitor, resistor, variable resistor, resistor series, capacitor series, and variable resistor network.

13. The bipolar forceps of claim 1, wherein the first sealing plate of the first electrically conductive surface has a different surface area than the second sealing plate of the first electrically conductive surface.