Spring loaded reciprocating tissue cutting mechanism in a forceps-style electrosurgical instrument

• US 7,500,975 B2
• Filed: 10/03/2005
• Issued: 03/10/2009
• Est. Priority Date: 11/19/2003
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Covidien AG (Medtronic Plc)
• Inventors: Cunningham, James S., Harvilla, Dennis J.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US11/242,488
• Publication Number:
  US 20060074417A1
• Time in Patent Office: 1,254 Days
• Field of Search: 606 48- 52, 606205-207
• US Class Current: 606/51
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00916 with means for switching or controlling the main function of the instrument or device
• CPC Class Codes: A61B 2018/00946 slidable
• CPC Class Codes: A61B 2018/1412 Blade
• CPC Class Codes: A61B 2018/1455 having a moving blade for cutting tissue grasped by the jaws

Abstract

Open electrosurgical forceps for sealing tissue which include a pair of first and second shaft portions each having a jaw member disposed at a distal end thereof. Each of the jaw members includes an electrically conductive sealing surface which communicates electrosurgical energy through tissue held therebetween with at least one of the jaw members including a knife slot defined along a length thereof. The knife slot is dimensioned to reciprocate a knife blade therefrom. The forceps also have a cutting mechanism which selectively actuates the knife blade from a first position wherein the knife blade is disposed at least substantially entirely within the knife slot of the jaw member to at least one subsequent position wherein the knife blade is at least partially deployed from the knife slot of the jaw member. The knife blade is displaceable in a direction transverse to a longitudinal axis of the forceps.

Claims

1. An open electrosurgical forceps for sealing tissue, the forceps comprising:

a pair of first and second shaft portions each having a jaw member disposed at a distal end thereof, said jaw members being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween;

each of said jaw members including an electrically conductive sealing surface which communicates electrosurgical energy through tissue held therein;

at least one of the jaw members including a knife slot defined along a length thereof, the knife slot being dimensioned to reciprocate a knife blade therefrom; and

a cutting mechanism for selectively actuating the knife blade from a first distal position wherein the knife blade is disposed at least substantially entirely within the knife slot of one jaw member to at least one subsequent proximal position wherein the knife blade is at least partially deployed from the knife slot of the same jaw member, wherein the knife blade is displaceable in a direction substantially transverse to a longitudinal axis of the forceps.

2. The open electrosurgical forceps according to claim 1, wherein the cutting mechanism includes:

a drive rod extending through a channel formed in at least one of the first and second shaft portions, the drive rod including a distal end operatively connected with the knife blade; and

a tab operatively connected to the drive rod for manipulating the drive rod in order to displace the knife blade between the first distal position and the at least one subsequent proximal position.

3. The open electrosurgical forceps according to claim 2, wherein the knife blade includes:

a first edge defining a cutting edge; and

a second edge, opposite the first edge, defining a camming surface, wherein the camming surface of the knife blade engages a corresponding camming surface formed in the slot of the jaw member to effectuate displacement of the knife blade between the first distal position and the at least one subsequent proximal position.

4. The open electrosurgical forceps according to claim 3, wherein the first edge of the knife blade resides in close proximity to the sealing surface when the knife blade is in the first distal position.

5. The open electrosurgical forceps according to claim 4, wherein the slot of the jaw member defines a camming surface configured to complement the camming surface of the knife blade.

6. The open electrosurgical forceps according to claim 5, wherein as the drive rod is displaced in a proximal direction the camming surface of the knife blade engages the camming surface of the slot formed in the jaw member to displace the knife blade from the first distal position to the at least one subsequent proximal position.

7. The open electrosurgical forceps according to claim 6, wherein the forceps include a biasing member for urging the drive rod to a distal-most position.

8. The open electrosurgical forceps according to claim 7, wherein the forceps include:

a handswitch operatively associated therewith, the handswitch providing a user with the ability to selectively apply electrosurgical energy.

9. The open electrosurgical forceps according to claim 8, wherein the forceps include:

a cable electrically interconnecting the forceps to a source of electrosurgical energy, the cable comprising;

a first lead electrically connected directly to a second of the jaw members; and

a second and third lead electrically connected to the handswitch.

10. The open electrosurgical forceps according to claim 9, wherein the knife blade is fabricated from a material capable of transmitting compressive and tensile forces.

11. The open electrosurgical forceps according to claim 10, wherein the knife blade is a biocompatible material.

12. The open electro surgical forceps according to claim 10, wherein the knife blade is fabricated from spring steel.

13. The open electrosurgical forceps according to claim 12, wherein each jaw member is arcuate.

14. The open electrosurgical forceps according to claim 13, wherein the slot formed in the respective jaw member is arcuate.

15. The open electrosurgical forceps according to claim 14, wherein the drive rod includes a first rack formed therein, wherein the first rack of the drive rod operative engages a pinion gear rotatably supported in the second shaft portion.

16. The open electrosurgical forceps according to claim 15, wherein the forceps include:

a second gear rack slidably supported in the second shaft portion and operatively engaged with the pinion gear.

17. The open electrosurgical forceps according to claim 16, wherein proximal displacement of the drive rod results in distal displacement of the second gear rack.

18. The open electrosurgical forceps according to claim 17, wherein the forceps include:

a biasing member operatively connected to the second gear rack for maintaining the second gear rack in a proximal-most position.

19. The open electrosurgical forceps according to claim 18, wherein the first and second shaft portions are pivotable with respect to one another.

20. The open electrosurgical forceps according to claim 1, wherein proximal displacement of the cutting mechanism results in the displacement of the knife blade in a direction having a longitudinal component of displacement and an orthogonal component of displacement relative to the longitudinal axis of the forceps.

21. The open electrosurgical forceps according to claim 1, wherein a longitudinal axis of the knife blade remains substantially parallel to a longitudinal axis of the at least one jaw member upon actuation of the knife blade from the first distal position to the at least one subsequent proximal position.

22. An open electrosurgical forceps for sealing tissue, the forceps comprising:

a pair of first and second shaft portions each having a jaw member disposed at a distal end thereof, said jaw members being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween;

each of said jaw members including an electrically conductive sealing surface which communicates electrosurgical energy through tissue held therebetween;

at least one of the jaw members including a slot defined along a length thereof, said slot being dimensioned to reciprocate a knife blade therefrom; and

a cutting mechanism which selectively actuates the knife blade from a first position to a second position;

wherein said knife blade is disposed at least substantially within the knife slot of the jaw member in said first position;

wherein said knife blade moves proximally from said first position to said second position in a cutting stroke;

wherein said knife blade partially deploys from said knife slot of said jaw member from said first position to said second position during said cutting stroke; and

wherein said knife blade further moves in a direction perpendicular to a longitudinal axis of the jaw members from said first position to said second position during said cutting stroke when said jaw members are in said subsequent position.

23. The open electrosurgical forceps according to claim 22, wherein movement of the knife from said first position to said second position during said cutting stroke places said knife blade under tensile stress;

and

wherein movement of the knife from said first position to said second position during said cutting stroke does not compress the knife.

24. An open electrosurgical forceps for sealing tissue, the forceps comprising:

a pair of first and second shaft portions each having a jaw member disposed at a distal end thereof, said jaw members being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween;

each of said jaw members including an electrically conductive sealing surface which communicates electrosurgical energy through tissue held therebetween;

at least one of the jaw members including a slot defined along a length thereof, said slot being dimensioned to reciprocate a knife blade therein, said knife blade having a complementary size to fit in said length of said slot; and

a cutting mechanism which selectively actuates said knife blade from a first position to a second position during a cutting stroke;

wherein said knife blade partially deploys from said knife slot of said jaw member from said first position to said second position during said cutting stroke; and

wherein said knife blade cuts the sealed tissue during a first stroke in a direction from a distal location to a proximal location when said jaw members are disposed in said subsequent position.

25. The open electrosurgical forceps according to claim 24, wherein said knife blade has an edge, said edge being pulled along the sealed tissue from said distal location to said proximal location upon said knife blade being deployed.

26. The open electrosurgical forceps according to claim 24, wherein said cutting stroke which moves said knife from said distal location to said proximal location is actuated by a switch.