| abstract |
A guide wire (15) for supporting monopolar arcing for cutting tissue and for ablating occlusions includes a flexible metal wire (302) including a distal end, an electrically insulating coating (306) extending along the wire, and an electrically and thermally insulating tip (310) having a distal end and attached to the wire, the wire extending through the electrically and thermally insulating tip and forming an electrode (312) at the distal ends of the wire and the tip. An electrosurgical apparatus for cutting tissue and for ablating occlusions includes a pulse generator (5, 6) having a variable output impedance for selectively generating a train of pulses of electrical energy for application to a guide wire (15) having an attached electrode. The pulse generator senses the load impedance and adjusts the output impedance to match the load impedance. The generator measures the relative electrical energy produced by an arc in response to a pulse, compares the relative electrical energy to a predetermined value to determine an energy difference, and adjusts the energy of a subsequent pulse to reduce the energy difference toward zero. |