Patent ID: 8932285
Filing Date: 2015-01-13
Classification: A61B

Abstract:
1. An electrosurgical instrument for the treatment of tissue, the instrument comprising an instrument shaft having a longitudinal axis, and an electrode assembly at one end of the shaft, the electrode assembly comprising first, second and third electrodes which are electrically insulated one from another by means of one or more insulation members, the first and second electrodes each having an exposed surface for treating tissue, the exposed surface of the first electrode being such as to treat tissue disposed in the longitudinal axis, and the exposed surface of the second electrode being such as to treat tissue disposed laterally of the longitudinal axis, the instrument having a first set of connections by which the first electrode can be placed in circuit with the second electrode such that, in use, a current path is established between the first and second electrodes, and a second set of connections by which the second electrode can be placed in circuit with the third electrode such that, in use, a current path is established between the second and third electrodes, the arrangement being such that the second electrode comprises distinct first and second portions in electrical connection one with the other, the first portion of the second electrode being substantially planar and the second portion of the second electrode being in the form of a ring circumnavigating the shaft of the instrument such that the first portion of the second electrode acts as an active electrode when the instrument is operated to treat tissue disposed laterally of the longitudinal axis, and the second portion of the second electrode acts as a return electrode when the instrument is operated to treat tissue disposed in the longitudinal axis.