Apparatus and method for rapid reliable electrothermal tissue fusion and simultaneous cutting

• US 20080188844A1
• Filed: 02/01/2007
• Published: 08/07/2008
• Est. Priority Date: 02/01/2007
• Status: Active Grant

• Current Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Inventors: McGreevy, Francis T., Pavlovsky, Katherine R.
• Granted Patent: US 9,498,277 B2
• Time in Patent Office: Days
• US Class Current: 606/28
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/082 Probes or electrodes therefor
• CPC Class Codes: A61B 18/085 Forceps, scissors
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 2018/00601 Cutting
• 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 2018/00714 Temperature
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: A61B 2018/00922 by switching or controlling the treatment energy directly within the hand-piece
• CPC Class Codes: A61B 2018/1415 multiple blades
• CPC Class Codes: A61B 2018/1455 having a moving blade for cutting tissue grasped by the jaws

Abstract

Pieces of tissue are fused together and simultaneously cut by compressing the pieces together at an interface, delivering an impulse of electrical power which is converted into sufficient thermal energy to fuse the pieces together at the interface and simultaneously cut the fused tissue pieces along a well-defined linear path. The impulse, and the fusion and the simultaneous cutting, occur within a preferable time of 1.5-2.0 seconds but no greater than 4.0 seconds. The temperature of the thermal energy is regulated between 220° C.-320° C. The force applied on the tissue pieces is sufficient to fuse the tissue at the interface followed by further compression to cut the fused tissue along the linear path as a result of the thermal energy and a zero distance gap between jaws which compress the tissue pieces. The jaws have smooth working surfaces with an Ra of 0.15 or less microns up to 0.40 microns.

Claims

1. Apparatus for fusing together pieces of tissue at an interface and simultaneously cutting the fused tissue along a linear path through the interface, comprising:

an instrument including jaws with working surfaces and a movement mechanism to move the jaws toward one another to compress the tissue pieces together at the interface between the working surfaces of the jaws, the working surfaces are formed of ceramic material and have a smoothness defined by an Ra of 0.40 microns or less, the movement mechanism having a capability for transferring sufficient force to compress the tissue pieces at the interface to a compressed tissue thickness sufficient to fuse the tissue pieces together at the interface followed by further compressing the tissue pieces at the interface to a zero thickness for cutting the fused together pieces of tissue; and

a power control device connected to deliver an impulse of electrical power to the jaws which contains sufficient energy to fuse and simultaneously cut the tissue pieces along the linear path at the interface within no greater than 4.0 seconds after the electrical power impulse is initiated, the power impulse creating thermal energy and maintaining a temperature of the thermal energy applied to the interface in the range of 220°

C. to 320°

C.

2. Apparatus as defined in claim 1, wherein the electrical power impulse has a time duration of no greater than 2.0 seconds.

3. Apparatus as defined in claim 1, wherein the electrical power impulse has a time duration of approximately 1.5 seconds.

4. Apparatus as defined in claim 1, wherein the electrical power impulse has a time duration in the range of 1.5 seconds to 2.0 seconds.

5. Apparatus as defined in claim 4, wherein the energy contained in the electrical power impulse is sufficient to permit moving the working surfaces away from the fused and cut interface immediately after termination of the electrical power impulse.

6. Apparatus as defined in claim 1, further comprising an electrical heating element within the jaws, and wherein the electrical power impulse is applied to the heating element to heat the jaws to transfer thermal energy from the working surfaces to the interface.

7. Apparatus as defined in claim 6, wherein the electrical power impulse elevates the temperature of the working surfaces at a rate of between 150°

C. per second to 500°

C. or greater per second.

8. Apparatus as defined in claim 6, wherein the energy contained in the electrical power impulse is sufficient to permit moving the working surfaces away from the fused and cut interface immediately after termination of the electrical power impulse.

9. Apparatus as defined in claim 6, wherein the electrical power impulse has a time duration in the range of 1.5 seconds to 2.0 seconds.

10. Apparatus as defined in claim 6, wherein the electrical power impulse produces an energy density at the working surfaces of at least 233 W/cm² of an effective area of the working surfaces.

11. Apparatus as defined in claim 6, wherein the electrical power impulse produces an energy density at the working surfaces of at least 388 W/cm² of an effective area of the working surfaces.

12. Apparatus as defined in claim 6, wherein the electrical power impulse produces an energy density at the working surfaces of 388 W/cm² to 465 W/cm² of an effective area of the working surfaces.

13. Apparatus as defined in claim 6, wherein the movement mechanism is operative to compress the tissue pieces at the interface with a force of at least 150 N to establish the zero thickness of the tissue along the linear path and to operatively move the working surfaces away from the fused and cut interface.

14. Apparatus as defined in claim 6, wherein the jaws and the working surfaces are formed of ceramic material having a thermal conductivity of at least 140 W/m°

K.

15. Apparatus as defined in claim 6, wherein the electrical power impulse is formed by direct current conducted to each heating element by the power control device.

16. Apparatus as defined in claim 1, wherein the Ra of the working surfaces is no greater than 0.25 microns.

17. Apparatus as defined in claim 1, wherein the working surfaces are ceramic material Ra of the working surfaces is approximately 0.15 microns or less.

18. Apparatus as defined in claim 1, wherein the movement mechanism produces pressure on the interface of at least 0.88 N/mm² of the effective area of the working surfaces.

19. Apparatus as defined in claim 1, wherein the electrical power impulse produces an energy density at the working surfaces in the range of 388 W/cm² to 465 W/cm² of an effective area of each working surface.

20. Apparatus as defined in claim 1, wherein the electrical power impulse produces an energy density at the working surfaces of at least 233 W/cm² of an effective area of the working surfaces.

21. Apparatus as defined in claim 1, wherein the electrical power impulse produces an energy density at the working surfaces of at least 388 W/cm² of an effective area of the working surfaces.

22. Apparatus as defined in claim 1, wherein the energy from the electrical power impulse creates strength between the tissue pieces at the interface after fusion which is less than the inherent strength of each tissue piece at the fused interface to allow separation of the tissue pieces at the fused interface before breaching the tissue pieces at or adjoining the interface.

23. Apparatus as defined in claim 1, wherein pieces of tissue are apposite walls of a vessel, and the compressed tissue thickness sufficient to fuse the apposite walls of the blood vessel is 0.05 mm to 0.10 mm.

24. Apparatus as defined in claim 1, wherein each of the working surfaces extends in a longitudinal dimension, and the movement mechanism moves the working surfaces toward and away from one another with the longitudinal dimensions of each working surface extending parallel to one another.

25. Apparatus as defined in claim 24, wherein at least one of the working surfaces curves convexly toward the other working surface in a direction transverse to the longitudinal dimension.

26. Apparatus as defined in claim 24, wherein the working surfaces curve laterally in a parallel relationship with each other transversely to the to the longitudinal dimension, and the linear path along which the fused interface is cut curves in a general parallel relationship to the curved relationship of the working surfaces.

27. Apparatus as defined in claim 1, wherein the power control device delivers the electrical power impulse separately to each jaw.

28. Apparatus as defined in claim 27, wherein each jaw further includes a temperature sensor which supplies a temperature signal to the power control device which is related to the temperature of each jaw, and the power control device separately regulates characteristics of the electrical power impulse delivered to each jaw in relation to the temperature signal.

29. Apparatus as defined in claim 28, wherein the power control device separately regulates characteristics of the electrical power impulse delivered to each jaw on the basis of a proportional, integral and derivative algorithm.

30. Apparatus for fusing together pieces of tissue at an interface and simultaneously cutting the fused tissue along a linear path through the interface, comprising:

an instrument including jaws and a movement mechanism to move the jaws toward one another to compress the tissue pieces together at the interface between the working surfaces of the jaws to fuse the tissue pieces together and to obtain a zero separation distance between the working surfaces of the jaws to simultaneously cut the compressed and fused tissue pieces along the linear path; and

a power control device connected to deliver an impulse of electrical power to the jaws which has a time duration of no greater than 4.0 seconds and which contains sufficient energy to fuse the tissue pieces together and to simultaneously cut the fused tissue pieces at the interface by creating a temperature applied to the interface in the range of 220°

C. to 320°

C. within the time duration of the electrical power impulse.

31. Apparatus as defined in claim 30, wherein the time duration of the electrical power impulse is no greater than 2.0 seconds.

32. A method of electrothermally fusing together pieces of tissue at an interface and simultaneously cutting the fused tissue along a linear path through the interface, comprising:

compressing the tissue pieces together at the interface sufficiently for fusing the tissue pieces together and for cutting the fused tissue pieces in the linear path through the fused tissue at the interface;

delivering an impulse of electrical power of no greater than 4.0 seconds time duration which contains sufficient energy to fuse the tissue pieces together at the interface and to simultaneously cut the fused tissue in the linear path through the fused tissue at the interface within the time duration of the electrical power impulse;

converting the electrical power impulse into thermal energy applied at the interface to fuse the tissue pieces and to simultaneously cut the fused tissue pieces in the linear path through the interface; and

regulating the temperature of the thermal energy applied at the interface in a range of 200°

C. to 320°

C. while fusing and simultaneously cutting the tissue pieces at the interface by controlling characteristics of the electrical power impulse.

33. A method as defined in claim 32, wherein the electrical power impulse has a time duration of no greater than 2.0 seconds.

34. A method as defined in claim 32, wherein the electrical power impulse has a time duration of approximately 1.5 seconds.

35. A method as defined in claim 32, wherein the electrical power impulse has a time duration in the range of 1.5 seconds to 2.0 seconds.

36. A method as defined in claim 35, further comprising:

releasing compression of the interface immediately after termination of the electrical power impulse.

37. A method as defined in claim 32, further comprising:

elevating the temperature of the thermal energy applied at the compressed interface at a rate of between 150°

C. per second to 500°

C. per second or greater from energy contained in the electrical power impulse.

38. A method as defined in claim 32, further comprising:

producing an energy density in the range of 388 W/cm² to 465 W/cm² of area of the compressed interface from the electrical power impulse.

39. A method as defined in claim 32, further comprising:

producing an energy density of at least 233 W/cm² of area of the compressed interface from the electrical power impulse.

40. A method as defined in claim 32, further comprising:

producing an energy density of at least 388 W/cm² of area of the compressed interface from the electrical power impulse.

41. A method as defined in claim 32, further comprising:

cutting the fused tissue pieces in a curved linear path through the interface.

42. A method as defined in claim 32, further comprising:

compressing the tissue pieces together at the interface to achieve essentially a zero thickness of the heated and compressed tissue pieces along the linear path.

43. A method as defined in claim 32, further comprising:

producing pressure of the least 0.88 N/mm² over the effective area of the fused interface while compressing the tissue pieces.

44. A method as defined in claim 32, further comprising:

compressing the tissue pieces at the interface by contacting the tissue pieces on opposite sides of the interface by working surfaces of jaws;

applying the thermal energy to heat the jaws; and

transferring thermal energy from the working surfaces to the compressed interface of the tissue pieces.

45. A method as defined in claim 44, further comprising:

forming electrical power impulse from direct current; and

applying the direct current of the electrical power impulse to heat each jaw.

46. A method as defined in claim 44, wherein each working surface is formed of ceramic material and each working surface has a smoothness defined by an Ra of 0.40 microns or less.

47. A method as defined in claim 44, wherein each of the working surfaces extends in a dimension, and further comprising:

releasing compression of the interface after fusion and simultaneous cutting by moving the working surfaces away from the fused and cut interface with the dimensions of each working surface extending parallel to one another.

48. A method as defined in claim 44, further comprising:

delivering an electrical power impulse to a heating element within each jaw; and

separately regulating characteristics the electrical power impulse delivered to the heating element within each jaw to regulate the temperature of thermal energy applied by the working surface from each jaw separately.

49. A method as defined in claim 32, further comprising:

releasing compression of the interface immediately after fusion without inducing shear forces on the fused interface.

50. A method as defined in claim 32, further comprising:

creating strength between the fused tissue pieces at the interface from the fusion which is less than the inherent strength of each tissue piece at the fused interface to allow separation of the tissue pieces at the interface before breaching the tissue pieces at or adjoining the fused interface.

51. A method as defined in claim 32, wherein pieces of tissue are apposite walls of a vessel, and the compressed tissue thickness sufficient to fuse the apposite walls of the blood vessel is 0.05 mm to 0.10 mm.

52. A method as defined in claim 51, wherein the vessel has a diameter of up to 8 mm.