Power control technique for beam-type electrosurgical unit
First Claim
1. In an electrosurgical unit which includes means for conducting a predetermined gas in a jet to tissue and means for transferring electrical energy in ionized conductive pathways in the gas jet, said electrical energy transferring means operatively transferring arcs to the tissue in the ionized conductive pathways in an active state to thereby create a predetermined electrosurgical effect on the tissue, said electrical energy transferring means operatively creating substantially only ionized conductive pathways in the gas jet in an inactive state to allow arc initiation upon transition to the active state, said electrical energy transferring means including electrosurgical generator means for generating target bursts of radio frequency electrical energy at a predetermined inactive repetition rate in the inactive state and for generating active bursts of radio frequency electrical energy at a predetermined active repetition rate in the active state, said electrical energy transferring means applying the bursts of radio frequency energy to the gas jet, and an improvement to said electrosurgical generator means comprising, in combination:
- repetition rate changing means for changing the predetermined repetition rate of the target bursts to a value substantially less than the predetermined repetition rate of the active bursts.
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Accused Products
Abstract
An electrosurgical generator in an electrosurgical unit (ESU) controls the repetition rate and the energy content of bursts of RF energy delivered to a gas jet supplied by the ESU, in order to maintain RF leakage current within acceptable limits while still achieving a sufficient state of ionization in the gas jet to reliably initiate the conduction of arcs to the tissue. The repetition rate of the RF bursts is substantially reduced in an inactive state when no arcs are delivered. A relatively small number of the RF bursts delivered during the inactive state have an increased or boosted energy content to assure an adequate ionization state in the gas jet.
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Citations
34 Claims
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1. In an electrosurgical unit which includes means for conducting a predetermined gas in a jet to tissue and means for transferring electrical energy in ionized conductive pathways in the gas jet, said electrical energy transferring means operatively transferring arcs to the tissue in the ionized conductive pathways in an active state to thereby create a predetermined electrosurgical effect on the tissue, said electrical energy transferring means operatively creating substantially only ionized conductive pathways in the gas jet in an inactive state to allow arc initiation upon transition to the active state, said electrical energy transferring means including electrosurgical generator means for generating target bursts of radio frequency electrical energy at a predetermined inactive repetition rate in the inactive state and for generating active bursts of radio frequency electrical energy at a predetermined active repetition rate in the active state, said electrical energy transferring means applying the bursts of radio frequency energy to the gas jet, and an improvement to said electrosurgical generator means comprising, in combination:
repetition rate changing means for changing the predetermined repetition rate of the target bursts to a value substantially less than the predetermined repetition rate of the active bursts. - View Dependent Claims (2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15)
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8. An invention as defined in .[.claim.]. .Iadd.claims .Iaddend.2, 5 or 7 wherein:
said .[.means supplies the active signal upon sensing.]. .Iadd.initiation condition is .Iaddend.the first arc to the tissue occurring while in the inactive state.
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16. In an electrosurgical unit which includes means for conducting a predetermined gas in a jet to tissue and means for transferring electrical energy in ionized conductive pathways in the gas jet, said electrical energy transferring means operatively transferring arcs to the tissue in the ionized conductive pathways in an active state to thereby create a predetermined electrosurgical effect on the tissue, said electrical energy transferring means operatively creating substantially only ionized conductive pathways in the gas jet in an inactive state to allow arc initiation upon transition to the active state, said electrical energy transferring means including electrosurgical generator means for generating target bursts of radio frequency electrical energy at a predetermined repetition rate in the inactive state and for generating active bursts of radio frequency electrical energy at a predetermined repetition rate in the active state, said electrical energy transferring means applying the bursts of radio frequency energy to the gas jet, and an improvement to said electrosurgical generator means comprising, in combination:
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means for generating the target bursts in a plurality of repeating sequences during the inactive state, each sequence including a plurality of target bursts; and booster means for substantially increasing the energy content of a predetermined plurality .Iadd.of .Iaddend.less than all of the target bursts occurring during each sequence, those target bursts of increased energy being booster target bursts and those other target bursts being normal target bursts. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method of operating an electrosurgical unit for conducting electrosurgery on tissue, comprising:
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conducting a predetermined gas in a jet to tissue; transferring electrical energy to the gas jet in an active state by generating active bursts of radio frequency electrical energy occurring at a predetermined active repetition rate to create arcs in ionized conductive pathways in the gas jet and to transfer arcs in the ionized conductive pathways to the tissue for achieving a predetermined electrosurgical effect on the tissue; transferring electrical energy to the gas jet in an inactive state by generating target bursts of radio frequency electrical energy occurring at a predetermined inactive repetition rate to create substantially only ionized conductive pathways in the gas jet which allow arc initiation upon transition to the active state; and establishing the predetermined inactive repetition rate of the target bursts at a predetermined value which is substantially less than the predetermined active repetition rate of the active bursts. .Iaddend. .Iadd. - View Dependent Claims (23, 24)
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27. bursts being normal target bursts. .Iaddend. .Iadd.37. A method as defined in claim 36 further comprising:
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sensing a condition indicative of the absence of at least one arc in the ionized conductive pathways during the active state; temporarily ceasing the generation of booster target bursts for a predetermined disabled time period upon sensing the absence condition, the predetermined disabled time period being at least the time period of one sequence; and beginning the generation of booster target bursts after the expiration of the predetermined disabled time period. .Iaddend. .Iadd.38. A method as defined in claim 37 wherein the sensed absence condition is the absence of a predetermined plurality of consecutive arcs in the active state. .Iaddend. .Iadd.39. A method as defined in claim 37 further comprising; sensing a predetermined active power level of electrical energy delivered to the gas jet in the active state; establishing the inactive repetition rate in response to sensing the absence of a relatively fewer predetermined plurality of consecutive arcs when the predetermined active power level is relatively higher; and establishing the inactive repetition rate in response to sensing the absence of a relatively greater predetermined plurality of consecutive arcs when the predetermined active power level is relatively lower. .Iaddend. .Iadd.40. A method as defined in claim 36 further comprising; generating a number of booster target bursts in each sequence in a range of less than ten percent of the total number of target bursts in each - View Dependent Claims (25, 26)
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28. sequence. .Iaddend. .Iadd.41. A method as defined in claim 36 further comprising:
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generating a number of booster target bursts in each sequence at approximately five percent of the total number of target bursts in each sequence; and increasing the energy content of the booster target bursts to a value approximately three times greater than the energy content of the normal target bursts. .Iaddend. .Iadd.42. A method of operating an electrosurgical unit for conducting electrosurgery on tissue, comprising; conducting a predetermined gas in a jet to tissue; transferring electrical energy to the gas jet in an active state by generating active bursts of radio frequency electrical energy occurring at a predetermined active repetition rate to create the arcs in ionized conductive pathways in the gas jet and to transfer arcs in the ionized conductive pathways to the tissue for achieving a predetermined electrosurgical effect on the tissue; transferring electrical energy to the gas jet in an inactive state by generating target bursts of radio frequency electrical energy occurring at a predetermined inactive repetition rate to create substantially only ionized conductive pathways in the gas jet which allow arc initiation upon transition to the active state, the target bursts occurring in a plurality of repeating sequences and each sequence including a plurality of target bursts; and increasing the energy content of a predetermined plurality of less than all of the target bursts occurring during each sequence, those target bursts of increased energy being booster target bursts and those other target bursts being normal target bursts. .Iaddend. .Iadd.43. A method as defined in claim 42 further comprising; generating a number of booster target bursts in each sequence in a range of less than ten percent of the total number of target bursts in each sequence. .Iaddend. .Iadd.44. A method as defined in claim 43 further comprising; consecutively generating the booster target bursts in each sequence. .Iaddend. .Iadd.45. A method as defined in claim 43 further comprising; increasing the energy content of the booster target bursts to a value approximately three times greater than the energy content of the normal target bursts. .Iaddend. .Iadd.46. A method as defined in claim 45 further comprising; generating a number of booster target bursts in each sequence at approximately five percent of the total number of target bursts in each sequence. .Iaddend. .Iadd.47. A method as defined in claim 42 further comprising; delaying the generation of booster target bursts for a predetermined time after ceasing the delivery of active bursts and commencing the delivery of
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29. normal target bursts. .Iaddend. .Iadd.48. An electrosurgical generator for an electrosurgical unit which includes means for conducting a predetermined gas in a jet to tissue and means for transferring arcs of electrical energy in ionized conductive pathways in the gas jet in an active state to create a predetermined electrosurgical effect on the tissue, the arcs in the active state resulting from bursts of radio frequency electrical energy occurring at a predetermined active repetition rate;
- said electrosurgical generator comprising;
burst generator means operative during an inactive state for generating bursts of radio frequency electrical energy to create substantially only ionized conductive pathways in the gas jet to allow arc initiation in the gas jet upon transition from the inactive state to the active state, the inactive state occurring other than during the occurrence of the active state; and repetition rate establishing means for controlling the burst generator means to establish a repetition rate of the bursts in the inactive state which is substantially less than the predetermined repetition rate of the
- said electrosurgical generator comprising;
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30. bursts during the active state. .Iaddend. .Iadd.49. An electrosurgical generator as defined in claim 48 further comprising:
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arc sensing means for sensing a condition indicative of the occurrence of an arc initiation to the tissue in ionized conductive pathways during the inactive state and for supplying an active signal upon sensing said initiation condition; and
wherein;said repetition rate establishing means is responsive to the active signal for operatively terminating the predetermined inactive repetition rate. .Iaddend. .Iadd.50. An electrosurgical generator as defined in claim 49 wherein; said initiation condition is the first arc to the tissue occurring while in the inactive state. .Iaddend. .Iadd.51. An electrosurgical generator as defined in claim 48 further comprising; arc sensing means for sensing a condition indicative of the absence of at least one arc in the ionized conductive pathways during the active state and for supplying a target signal upon sensing said absence condition; and said repetition rate establishing means is responsive to the target signal for establishing the predetermined inactive repetition rate. .Iaddend.
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31. Iadd.52. An electrosurgical generator as defined in claim 51 wherein:
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said absence condition is the absence of a predetermined plurality of consecutive arcs in the active state. .Iaddend. .Iadd.53. An electrosurgical generator as defined in claim 48 further comprising; arc sensing means for sensing a condition indicative of the occurrence of an arc initiation to the tissue in the ionized conductive pathways during the inactive state and for supplying an active signal upon sensing said initiation condition, and further sensing a condition indicative of the absence of at least one arc in the ionized pathways during the active state and for supplying a target signal upon sensing said absence condition; and said repetition rate establishing means is responsive to the active and target signals for operatively terminating the predetermined inactive repetition rate in response to the active signal and for operatively establishing the predetermined inactive repetition rate in response to the target signal. .Iaddend. .Iadd.54. An electrosurgical generator as defined in claim 53 wherein; said absence condition is the absence of a predetermined plurality of
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32. consecutive arcs in the active state. .Iaddend. .Iadd.55. An electrosurgical generator as defined in claim 54 wherein:
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said initiation condition is the first arc to the tissue occurring while in the inactive state. .Iaddend. .Iadd.56. An electrosurgical generator as defined in claim 53 wherein; said burst generator means generates target bursts in a plurality of repeating sequences during the inactive state, each sequence includes a plurality of target bursts; and
said burst generator means further includes;booster means for increasing the energy content of a predetermined plurality of less than all of the target bursts occurring during each sequence, those target bursts of increased energy being booster target bursts and those other target bursts being normal target bursts. .Iaddend. .Iadd.57. An electrosurgical generator as defined in claim 56 wherein said burst generator means further includes; temporary disabling means responsive to the target signal for temporarily disabling the booster means for a predetermined disabled time period after the target signal is supplied, the predetermined disabled time period being at least the time period of one sequence of target bursts; and reenabling means responsive to the expiration of the predetermined disabled time period for thereafter enabling said booster means to commence
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33. operating as recited. .Iaddend. .Iadd.58. An electrosurgical generator as defined in claim 57 wherein:
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said absence condition is the absence of a predetermined plurality of consecutive arcs in the active state. .Iaddend. .Iadd.59. An electrosurgical generator as defined in claim 57 wherein; said arc sensing means is further responsive to a predetermined active power level of electrical energy delivered to the gas jet in the active state and operatively supplies the target signal upon the absence of a relatively fewer predetermined plurality of consecutive arcs when the predetermined active power level is relatively higher and supplies the target signal upon the absence of a relatively greater predetermined plurality of consecutive arcs when the active power level is relatively lower. .Iaddend. .Iadd.60. An electrosurgical generator as defined in claim 59 wherein; the booster target bursts are consecutive in each sequence. .Iaddend. .Iadd.61. An electrosurgical generator as defined in claim 60 wherein the number of booster target bursts in each sequence is in a range of less than ten percent of the total number of target bursts in each sequence. .Iaddend. .Iadd.62. An electrosurgical generator as defined in claim 48 wherein; the burst generator means generates target bursts in a plurality of repeating sequences during the inactive state, each sequence includes a plurality of target bursts; and
said target burst generator means further includes;booster means for increasing the energy content of a predetermined plurality of less than all of the target bursts occurring during each sequence, those target bursts of increased energy being booster target bursts and those other target bursts being normal target bursts. .Iaddend. .Iadd.63. An electrosurgical generator as defined in claim 62 further comprising; arc sensing means for sensing a condition indicative of the absence of at least one arc in the ionized conductive pathways during the active state and for supplying a target signal upon sensing said absence condition; and
wherein said burst generator means further includes;temporary disabling means responsive to the target signal for temporarily disabling the booster means for a predetermined disabled time period after the target signal is supplied upon sensing the absence condition, the predetermined disabled time period being at least the time period of one sequence; and reenabling means responsive to the expiration of the predetermined disabled time period for thereafter enabling said booster means to commence operating as recited. .Iaddend. .Iadd.64. An electrosurgical generator as defined in claim 63 wherein; said absence condition is the absence of a predetermined plurality of consecutive arcs in the active state. .Iaddend. .Iadd.65. An electrosurgical generator as defined in claim 63 wherein; said arc sensing means is further responsive to a predetermined active power level of electrical energy delivered to the gas jet in the active state and operatively supplies the target signal upon the absence of a relatively fewer predetermined plurality of consecutive arcs when the predetermined active power level is relatively higher and supplies the target signal upon the absence of a relatively greater predetermined plurality of consecutive arcs when the active power level is relatively lower. .Iaddend. .Iadd.66. An electrosurgical generator for an electrosurgical unit which includes means for conducting a predetermined gas in a jet to tissue and means for transferring arcs of electrical energy in ionized conductive pathways in the gas jet in an active state to create a predetermined electrosurgical effect on the tissue, the arcs in the active state resulting from bursts of radio frequency electrical energy occurring at a predetermined active repetition rate;
said electrosurgical generator comprising;burst generator means for generating a plurality of repeating sequences of bursts of radio frequency electrical energy during an inactive state to create substantially only ionized conductive pathways in the gas jet to allow arc initiation in the gas jet upon transition from the inactive state to the active state, each sequence including a plurality of bursts; and booster means for increasing the energy content of a predetermined plurality of less than all of the bursts occurring during each sequence in the inactive state, those bursts of increased energy during the inactive state being booster target bursts and those other bursts being normal target bursts. .Iaddend. .Iadd.67. An electrosurgical generator as defined in claim 66 wherein the number of booster target bursts in each sequence is in a range of less than ten percent of the total number of target bursts in each sequence. .Iaddend. .Iadd.68. An electrosurgical generator as defined in claim 67 wherein; the booster target bursts are consecutive in each sequence. .Iaddend.
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34. Iadd.9. An electrosurgical generator as defined in claim 67 wherein:
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the energy content of the booster target bursts is approximately three times the energy content of the normal target bursts. .Iaddend. .Iadd.70. An electrosurgical generator as defined in claim 69 wherein the number of booster bursts in each sequence is approximately five percent of the total number of bursts in each sequence. .Iaddend. .Iadd.71. An electrosurgical generator as defined in claim 66 wherein said booster means further comprises; means for delaying the application of booster target bursts for a predetermined time after the transition from the delivery of active bursts to the delivery of normal target bursts. .Iaddend.
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Specification