Electrosurgical apparatus for laparoscopic and like procedures

• US 5,688,269 A
• Filed: 03/30/1993
• Issued: 11/18/1997
• Est. Priority Date: 07/10/1991
• Status: Expired due to Term

• Current Assignee: Electroscope Incorporated
• Original Assignee: Electroscope Incorporated
• Inventors: Laviolette, John J., Gannoe, James Richard, Newton, David W., Boyle, Don R., Odell, Roger C.
• Primary Examiner(s): Shay, David M.
• Application Number:
  US08/038,104
• Time in Patent Office: 1,694 Days
• Field of Search: 606/32-35, 606/37-42, 606/44-47
• US Class Current: 606/46
• 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 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1487 Trocar-like, i.e. devices producing an enlarged transcutaneous opening
• CPC Class Codes: A61B 2018/00178 Electrical connectors
• CPC Class Codes: A61B 90/04 Protection of tissue around surgical sites against effects of non-mechanical surgery, e.g. laser surgery protection of eyes against laser radiation A61F9/022
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity

Abstract

A safety shield for use in laparoscopic or like electrosurgical procedures where the shield surrounds the active electrode and extends from a trocar or the like to the field of view of the surgical procedure. The shield is connected to the return lead via a low impedance path which includes monitor circuitry for determining whether the shield current is associated with an abnormal condition. The shield may also serve as a structural element of the instrument and be connected to the instrument body so that the instrument is maintained at or near patient potential. Moreover, a unitary connector is provided whereby connection to the active electrode and shield may be made by a single connector. Attached to the connector is a cable in which both the active and shield conductors are contained for at least a distance sufficient to minimize clutter in the operative site. Articulatable instruments incorporating the above features are also disclosed where different implementations are utilized to absorb the longitudinal reactive forces generated upon articulation of the tips. An adjustable insulating sheath for use with the articulatable instruments is also utilized so that the tips can be exposed more or less depending upon the particular surgical application.

Claims

1. Laparoscopic electrosurgical apparatus for use with an electrosurgical generator comprising:

a trocar cannula having a tubular passage for providing a conduit through a patient'"'"'s skin to a peritoneal cavity of the patient, the trocar cannula having a proximal end and a distal end;

a tubular conductive shield having an inner surface and an outer surface and being removably insertable to an inserted position through the trocar cannula conduit, said shield having a distal end and a proximal end;

an active electrode probe having a tip and being adapted for connection to an electrosurgical generator and extending through the tubular conductive shield for effecting at the tip thereof an electrosurgical procedure within the peritoneal cavity where, when the tubular shield is in the inserted position thereof, the shield surrounds the active probe from at least (a) a proximal point prior to the distal end of the trocar cannula to (b) a distal point distal to the distal end of the trocar cannula and in proximity to the tip of the active probe;

at least one layer of electrical insulation disposed between the active probe and the inner surface of the tubular conductive shield;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about twenty ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

56. An electrosurgical apparatus as in claims 1, 2, 5, 6 or 7 where said tubular conductive shield has a layer of electrical insulation provided over at least a portion of an outer surface thereof.

59. Apparatus as in claims 1, 2, 5, 6 or 7 where said electrosurgical generator includes a return lead and where said monitor is connected between said tubular conductive shield and said return lead.

2. An electrosurgical apparatus for use with an electrosurgical generator comprising:

a trocar cannula having a tubular passage for providing a conduit through a patient'"'"'s skin where the trocar cannula has a proximal end and a distal end;

a tubular conductive shield having an inner surface and an outer surface and being removably insertable to an inserted position through the trocar cannula conduit, said shield having a distal end and a proximal end;

an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and extending through the tubular conductive shield for effecting at the tip thereof an electrosurgical procedure within a patient'"'"'s body where, when the tubular shield is in the inserted position thereof, the shield surrounds and is electrically insulated from the active probe from at least (a) a proximal point prior to the distal end of the trocar cannula to (b) a distal point distal to the distal end of the trocar cannula and in proximity to the tip of the active probe;

at least one layer of electrical insulation disposed between the active probe and the inner surface of the tubular conductive shield;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about twenty ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

3. A safety shield system for use with a laparoscopic electrosurgical apparatus including a trocar cannula having a tubular passage for providing a conduit through a patient'"'"'s skin to a peritoneal cavity of the patient, the trocar cannula having a proximal end and a distal end, an electrosurgical generator and an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and extending through the trocar cannula for effecting at the tip thereof an electrosurgical procedure within the peritoneal cavity, said safety shield comprising

a tubular conductive shield having an inner surface and an outer surface a distal end and a proximal end and being removably insertable to an inserted position through the trocar cannula, and where, when the tubular shield is in the inserted position thereof, the shield surrounds, and is electrically insulated from, the active probe from at least (a) a proximal point prior to the distal end of the trocar cannula to (b) a distal point distal to the distal end of the trocar cannula and in proximity to the tip of the active probe;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about twenty ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

57. A safety shield system as in claims 3 or 4 where said tubular conductive shield has a layer of electrical insulation provided over at least a portion of an outer surface thereof.

60. A safety shield system as in claims 3 or 4 where said electrosurgical generator includes a return lead and where said monitor is connected between said tubular conductive shield and said return lead.

4. A safety shield system for use with an electrosurgical apparatus including a trocar cannula having a tubular passage for providing a conduit through a patient'"'"'s skin where the trocar cannula has a proximal end and a distal end, an electrosurgical generator, and an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and extending through the trocar cannula for effecting at the tip thereof an electrosurgical procedure, said safety shield comprising

a tubular conductive shield having an inner surface and an outer surface a distal end and a proximal end and being removably insertable to an inserted position through the trocar cannula, and where, when the tubular shield is in the inserted position thereof, the shield surrounds, and is electrically insulated from, the active probe from at least (a) a proximal point prior to the distal end of the trocar cannula to (b) a distal point distal to the distal end of the trocar cannula and in proximity to the tip of the active probe;

an electrical terminal disposed on the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about twenty ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

5. An electrosurgical apparatus for use with an electrosurgical generator comprising:

a handpiece having a tubular passage extending therethrough, the handpiece having a proximal end and a distal end;

a tubular conductive shield having an inner surface and an outer surface and extending at least partially through the handpiece passage, said shield having a distal end and a proximal end;

an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and extending through the tubular conductive shield for effecting at the tip thereof an electrosurgical procedure where the shield surrounds the active probe from at least (a) a proximal point prior to the distal end of the handpiece to (b) a distal point distal to the distal end of the handpiece and in proximity to the tip of the active probe;

at least one layer of electrical insulation disposed between the active probe and the inner surface of the tubular conductive shield;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about twenty ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

6. An electrosurgical apparatus for use with an electrosurgical generator comprising:

an outer member;

a tubular conductive shield having an inner surface and an outer surface and being mounted with respect to and extending at least partially through the outer member;

an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and being mounted with respect to and extending through the tubular conductive shield for effecting at the tip thereof an electrosurgical procedure;

at least one layer of electrical insulation mounted between the active probe and the inner surface of the tubular conductive shield;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about 20 ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

9. Apparatus as in claims 6 or 7 where said one layer of insulation is mounted on said active probe.

10. Apparatus as in claims 6 or 7 where said one layer of insulation is mounted on the inner surface of said shield.

11. Apparatus as in claims 6 or 7 including at least two layers of insulation disposed between the active probe and the shield where one of the layers is mounted on the active probe and the other is mounted on the inner surface of the shield.

12. Apparatus as in claims 6 or 7 including alarm means responsive to the monitor circuitry to provide an indication of said abnormal condition.

13. Apparatus as in claims 6 or 7 including means responsive to the monitor circuitry for deactivating the electrosurgical generator in response to said abnormal condition being detected.

14. Apparatus as in claims 6 or 7 where said monitor circuitry includes circuitry for determining whether the amplitude of the shield current exceeds a predetermined threshold.

15. Apparatus as in claims 6 or 7 where said monitor circuitry includes circuitry for determining whether the ratio of the shield current to the current in the return lead to the electrosurgical generator exceeds a predetermined threshold.

16. Apparatus as in claims 6 or 7 where said monitor circuitry includes circuitry for determining whether a predetermined phase relationship exists between the shield current and the voltage applied to the active lead of the electrosurgical generator.

17. Apparatus as in claim 16 where said predetermined phase relationship is a substantially in phase relationship corresponding to said abnormal condition.

18. Apparatus as in claims 6 or 7 where said monitor circuitry includes spectral sensing circuitry responsive to at least one preselected frequency bandwidth of the shield current.

19. Apparatus as in claim 18 where said spectral sensing circuitry determines whether the amplitude of the electrical energy within said bandwidth exceeds a predetermined threshold.

20. Apparatus as in claim 18 where said frequency bandwidth is below the operating frequency of the electrosurgical generator.

21. Apparatus as in claim 20 where said bandwidth extends from about 50-250 KHz.

22. Apparatus as in claims 6 or 7 wherein said electrosurgical generator is disposed within a housing and where said monitor circuitry is disposed within said housing.

23. Apparatus as in claims 6 or 7 wherein said electrosurgical generator is disposed within a housing and where said monitor circuitry is disposed outside said housing.

24. Apparatus as in claim 23 including means for battery powering the monitor circuitry.

25. Apparatus as in claim 24 where said battery powering means includes means responsive to the flow of current in the shield to provide the battery power.

26. Apparatus as in claim 23 including adaptor means for connecting the monitor circuitry and the return electrode to the return terminal of the electrosurgical generator.

27. Apparatus as in claim 26 where said adaptor means includes sensing means for sensing whether a return electrode has been connected thereto and said monitor circuitry includes means responsive to the sensing means for at least providing an alert in response to the return electrode not being connected to the adaptor.

28. Apparatus as in claim 26 where said adaptor means includes sensing means for sensing whether the adaptor has been connected to the electrosurgical generator and said monitor circuitry includes means responsive to the sensing means for at least providing an alert in response to the adaptor not being connected to the generator.

29. Apparatus as in claims 6 or 7 where said monitor circuitry includes circuitry for determining whether a predetermined amount of shield current is present subsequent to the activation of the electrosurgical generator.

30. Apparatus as in claim 29 including means responsive to voltage applied to the active lead of the generator to sense said activation of the generator.

31. Apparatus as in claim 29 including means responsive to the current in the return lead to the generator to sense said activation of the generator.

32. Apparatus as in claims 6 or 7 including a shield-to-ground detection means for detecting whether the return electrode is connected to the electrosurgical generator including means for detecting whether the voltage on the tubular shield exceeds a predetermined threshold.

33. Apparatus as in claims 6 or 7 including means for latching the tubular conductive shield with respect to the active electrode to thereby provide the capability of adjusting the position of the distal end of the tubular conductive shield with respect to the distal end of the active electrode.

7. An electrosurgical apparatus for use with an electrosurgical generator comprising:

a tubular conductive shield having an inner surface and an outer surface;

an active electrode probe having a tip and being adapted for connection to said electrosurgical generator and being mounted with respect to and extending through the tubular conductive shield for effecting at the tip thereof an electrosurgical procedure;

at least one layer of electrical insulation mounted between the active probe and the inner surface of the tubular conductive shield;

an electrical terminal connected to the shield and adapted for connecting the shield to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and said reference potential where the impedance between said electrical terminal and said reference potential is not more than about 20 ohms, said monitor circuitry being responsive to current in the shield to determine whether said abnormal condition exists.

8. An electrosurgical apparatus for use with an electrosurgical generator comprising:

an electrically conductive, outer member having an opening extending therethrough;

an active electrode probe having a tip and being adapted for connection to an electrosurgical generator and being mounted with respect to and extending at least partially through the outer member for effecting at the tip thereof an electrosurgical procedure;

at least one layer of electrical insulation mounted between the active probe and the outer member;

an electrical terminal connected to the outer member and for connecting the outer member to a reference potential;

whereby any abnormal condition which causes current to flow in said shield from said active probe is conducted to said reference potential to thus lessen a risk of patient injury; and

monitor circuitry connected between said electrical terminal and the return lead of the electrosurgical generator where the impedance between said electrical terminal and said reference potential is not more than about 20 ohms, said monitor circuitry being responsive to current in the outer member to determine whether said abnormal condition exists.

34. Apparatus as in claim 8 including alarm means responsive to the monitor circuitry to provide an indication of said abnormal condition.

35. Apparatus as in claim 8 including means responsive to the monitor circuitry for deactivating the electrosurgical generator in response to said abnormal condition being detected.

36. Apparatus as in claim 8 where said monitor circuitry includes circuitry for determining whether the amplitude of the shield current exceeds a predetermined threshold.

37. Apparatus as in claim 8 where said monitor circuitry includes circuitry for determining whether the ratio of the shield current to the current in the return lead to the electrosurgical generator exceeds a predetermined threshold.

38. Apparatus as in claim 8 where said monitor circuitry includes at least circuitry for determining whether a predetermined phase relationship exists between the shield current and the voltage applied to the active lead of the electrosurgical generator.

39. Apparatus as in claim 38 where said predetermined phase relationship is a substantially in phase relationship corresponding to said abnormal condition.

40. Apparatus as in claim 8 where said monitor circuitry includes spectral sensing circuitry responsive to at least one preselected frequency bandwidth of the shield current.

41. Apparatus as in claim 40 where said spectral sensing circuitry determines whether the amplitude of the electrical energy within said bandwidth exceeds a predetermined threshold.

42. Apparatus as in claim 40 where said frequency bandwidth is below the operating frequency of the electrosurgical generator.

43. Apparatus as in claim 42 where said bandwidth extends from about 50-250 KHz.

44. Apparatus as in claim 43 where said electrosurgical generator is disposed within a housing.

45. Apparatus as in claim 44 where said monitor circuitry is disposed within said housing.

46. Apparatus as in claim 44 where said monitor circuitry is disposed outside said housing.

47. Apparatus as in claim 46 including means for battery powering the monitor circuitry.

48. Apparatus as in claim 47 where said battery powering means includes means responsive to the flow of current in the shield to provide the battery power.

49. Apparatus as in claim 46 including adaptor means for connecting the monitor circuitry and the return electrode to the return terminal of the electrosurgical generator.

50. Apparatus as in claim 49 where said adaptor means includes sensing means for sensing whether a return electrode has been connected thereto and said monitor circuitry includes means responsive to the sensing means for at least providing an alert in response to the return electrode not being connected to the adaptor.

51. Apparatus as in claim 49 where said adaptor means includes sensing means for sensing whether the adaptor has been connected to the electrosurgical generator and said monitor circuitry includes means responsive to the sensing means for at least providing an alert in response to the adaptor not being connected to the generator.

52. Apparatus as in claim 8 where said monitor circuitry includes circuitry for determining whether a predetermined amount of shield current is present subsequent to the activation of the electrosurgical generator.

53. Apparatus as in claim 52 including means responsive to voltage applied to the active lead of the generator to sense said activation of the generator.

54. Apparatus as in claim 52 including means responsive to the current in the return lead to the generator to sense said activation of the generator.

55. Apparatus as in claim 8 including a shield-to-ground detection means for detecting whether the return electrode is connected to the electrosurgical generator including means for detecting whether the voltage on the tubular shield exceeds a predetermined threshold.

58. An electrosurgical apparatus as in claim 8 where said electrically conductive, outer member has a layer of electrical insulation provided over at least a portion of an outer surface thereof.

61. Apparatus as in claim 8 where said electrosurgical generator includes a return lead and where said monitor is connected between said electrically conductive, outer member and said return lead.