Patent ID: 9060765
Filing Date: 2015-06-23
Classification: A61B

Abstract:
1. An electrosurgical apparatus comprising: a housing having a passage extending therethrough, the housing having a proximal end and a distal end; an electrically conducting tube having a proximal end and a distal end, the electrically conducting tube being disposed in the passage of the housing; an insulating outer tube having a proximal end and a distal end, the outer tube disposed around the electrically conducting tube with the proximal end of the outer tube coupled to the distal end of the housing, the electrically conducting tube being movable along a longitudinal axis of the housing and outer tube; and an electrically conducting blade coupled to the distal end of the electrically conducting tube, wherein in a first position of the electrically conducting tube, the blade extends beyond the distal end of the outer tube for mechanical cutting and, in a second position of the electrically conducting tube, the blade is retracted within the outer tube and is energized via the electrically conducting tube to form plasma when an inert gas flows through the electrically conducting tube, wherein the electrically conducting tube includes: a first, inner flow tube having a proximal end and a distal end; a second, outer flow tube having a proximal end and a distal end; and a cylindrical insulator disposed around the distal end of the first, inner flow tube for coupling the first, inner flow tube to an inner portion of the proximal end of the second, outer flow tube, wherein an overlapping portion of the first, inner flow tube, the cylindrical insulator and the second, outer flow tube forms a structural current limiting capacitor to limit current applied to an operative site when the electrically conducting tube is energized and at least one of the first, inner flow tube and second, outer flow tube is movable relative to each other to varying a capacitance value of the structural Cu ent limiting capacitor.